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Suppose that you have an abstract for a scientific paper: in a recent publication we have presented the stochastic green function ( sgf ) algorithm , which has the properties of being general and easy to apply to any lattice hamiltonian of the form @xmath0 , where @xmath1 is diagonal in the chosen occupation number basis and @xmath2 has only positive matrix elements . we propose here a modified version of the update scheme that keeps the simplicity and generality of the original sgf algorithm , and enhances significantly its efficiency . . And you have already written the first three sentences of the full article: monte carlo methods @xcite appeared about sixty years ago with the need to evaluate numerical values for various complex problems . these methods evolved and were applied early to quantum problems , thus putting within reach exact numerical solutions to non - trivial quantum problems @xcite . many improvements of these methods followed , avoiding critical slowing down near phase transitions and allowing to work directly in the continuous imaginary time limit @xcite . in recent years ,. Please generate the next two sentences of the article

interest in methods that work in the canonical ensemble with global updates yet allow access to green functions has intensified @xcite . however , a method that works well for a given hamiltonian often needs major modifications for another .

Suppose that you have an abstract for a scientific paper: this paper introduces kernel - based information criterion ( kic ) for model selection in regression analysis . the novel kernel - based complexity measure in kic efficiently computes the interdependency between parameters of the model using a variable - wise variance and yields selection of better , more robust regressors . experimental results show superior performance on both simulated and real data sets compared to leave - one - out cross - validation ( loocv ) , kernel - based information complexity ( icomp ) , and maximum log of marginal likelihood in gaussian process regression ( gpr ) . . And you have already written the first three sentences of the full article: model selection is an important problem in many areas including machine learning . if a proper model is not selected , any effort for parameter estimation or prediction of the algorithm s outcome is hopeless . given a set of candidate models , the goal of model selection is to select the model that best approximates the observed data and captures its underlying regularities .. Please generate the next two sentences of the article

model selection criteria are defined such that they strike a balance between the _ goodness - of - fit ( gof ) _ , and the _ generalizability _ or _ complexity _ of the models .

Suppose that you have an abstract for a scientific paper: american options in a multi - asset market model with proportional transaction costs are studied in the case when the holder of an option is able to exercise it gradually at a so - called mixed ( randomised ) stopping time . the introduction of gradual exercise leads to tighter bounds on the option price when compared to the case studied in the existing literature , where the standard assumption is that the option can only be exercised instantly at an ordinary stopping time . algorithmic constructions for the bid and ask prices and the associated superhedging strategies and optimal mixed stoping times for an american option with gradual exercise are developed and implemented , and dual representations are established . . And you have already written the first three sentences of the full article: this work on pricing american options under proportional transaction costs goes back to the seminal discovery by @xcite that to hedge against a buyer who can exercise the option at any ( ordinary ) stopping time , the seller must in effect be protected against all mixed ( randomised ) stopping times . this was followed by @xcite , who established a non - constructive dual representation for the set of strategies superhedging the seller s ( though not the buyer s ) position in an american option under transaction costs . efficient iterative algorithms for computing the upper and lower hedging prices of the option , the hedging strategies , optimal stopping times as well as dual representations for both the seller and the buyer of an american option under transaction costs were developed by @xcite in a model with two assets , and @xcite in a multi - asset model .. Please generate the next two sentences of the article

all these approaches take it for granted that the buyer can only exercise the option instantly , at an ordinary stopping time of his choosing . by contrast , in the present paper we allow the buyer the flexibility to exercise an american option gradually , rather than all at a single time instance . though it would be difficult in practice to exercise a fraction of an option contract and to hold on to the reminder to exercise it later , the holder of a large portfolio of options may well choose to exercise the individual contracts on different dates if that proves beneficial .

Suppose that you have an abstract for a scientific paper: the no@xmath0a collaboration has constructed a 14,000 ton , fine - grained , low - z , total absorption tracking calorimeter at an off - axis angle to an upgraded numi neutrino beam . this detector , with its excellent granularity and energy resolution and relatively low - energy neutrino thresholds , was designed to observe electron neutrino appearance in a muon neutrino beam , but it also has unique capabilities suitable for more exotic efforts . in fact , if an efficient upward - going muon trigger with sufficient cosmic ray background rejection can be demonstrated , no@xmath0a will be capable of a competitive indirect dark matter search for low - mass wimps . the cosmic ray muon rate at the no@xmath0a far detector is about 100 khz and provides the primary challenge for triggering and optimizing such a search analysis . the status of the no@xmath0a upward - going muon trigger is presented . . And you have already written the first three sentences of the full article: wimps captured by the gravitational field of the sun that are slowed through collisions with solar matter can accumulate in the solar core . there , wimp annihilation may produce neutrinos with much larger energy than solar neutrinos . the signal would be an excess of high - energy ( @xmath1gev ) neutrino events pointing back to the sun @xcite .. Please generate the next two sentences of the article

the cleanest signature at no@xmath0a will be from @xmath2 cc events producing upward - going muons that can be reconstructed in the no@xmath0a detector . the large and unique no@xmath0a far detector , with its excellent granularity and energy resolution , and relatively low - energy neutrino thresholds , is an ideal tool for these indirect dark matter searches . at no@xmath0a , the neutrino analyses simply store events synchronous with the numi beam . for non - beam exotic physics searches , so - called data - driven triggers @xcite are required to select events of interest . only the upward - going flux will be considered in order to suppress the cosmic - ray background .

Suppose that you have an abstract for a scientific paper: the structural energetics of pdti and ptti have been studied using first - principles density - functional theory with pseudopotentials and a plane - wave basis . we predict that in both materials , the experimentally reported orthorhombic @xmath0 phase will undergo a low - temperature phase transition to a monoclinic @xmath1 ground state . within a soft - mode framework , we relate the @xmath0 structure to the cubic @xmath2 structure , observed at high temperature , and the @xmath1 structure to @xmath0 via phonon modes strongly coupled to strain . in contrast to niti , the @xmath0 structure is extremely close to hcp . we draw on the analogy to the bcc - hcp transition to suggest likely transition mechanisms in the present case . . And you have already written the first three sentences of the full article: shape memory alloys ( sma ) have attracted a great deal of attention due to their important technological applications , including mechanical actuator devices and medical stents . the shape memory effect also gives rise to superelasticity , which finds applications in stents and spectacle frames . the shape memory effect is related to a reversible martensitic ( diffusionless ) phase transformation .. Please generate the next two sentences of the article

it has been shown that the martensitic transformation can be induced by applied fields , temperature or both , and the mechanical properties of materials , therefore , can be controlled accordingly . in many systems , including those discussed in the present work , alloying can dramatically change the properties and transition temperatures of the materials , reflecting the importance of electronic features , specifically fermi surface effects , in the structural energetics of sma . there are several complementary approaches to modelling of the shape memory effect .

Suppose that you have an abstract for a scientific paper: there has been a considerable amount of interest in recent years on the robustness of networks to failures . many previous studies have concentrated on the effects of node and edge removals on the connectivity structure of a _ static _ network ; the networks are considered to be static in the sense that no compensatory measures are allowed for recovery of the original structure . real world networks such as the world wide web , however , are not static and experience a considerable amount of turnover , where nodes and edges are both added and deleted . considering degree - based node removals , we examine the possibility of preserving networks from these types of disruptions . we recover the original degree distribution by allowing the network to react to the attack by introducing new nodes and attaching their edges via specially tailored schemes . we focus particularly on the case of non - uniform failures , a subject that has received little attention in the context of evolving networks . using a combination of analytical techniques and numerical simulations , we demonstrate how to preserve the _ exact _ degree distribution of the studied networks from various forms of attack . recent years have witnessed a substantial amount of interest within the physics community in the properties of networks @xcite . techniques from statistical physics coupled with the widespread availability of computing resources have facilitated studies ranging from large scale empirical analysis of the worldwide web , social networks , biological systems , to the development of theoretical models and tools to explore the various properties of these systems @xcite . a relatively large body of work has been devoted to the study of degree distributions of networks , focusing both on their measurement , and formulation of theories to explain their emergence and their effects on various properties such as resilience and percolation . these studies are mostly aimed at networks in the real world that evolve.... And you have already written the first three sentences of the full article: consider a network which evolves under the removal and addition of vertices . in each unit of time we add @xmath1 vertex and remove @xmath2 vertices . removal of a vertex also implies that all the edges incident on that vertex vanish and consequently the degree of vertices at the end of those edges decrease . here. Please generate the next two sentences of the article

@xmath2 can be interpreted as the ratio of vertices removed to those added , so @xmath3 represents a growing network , @xmath4 a shrinking one , while @xmath5 implies vertex turnover but fixed network size . the equations to follow represent the completely general case .

Suppose that you have an abstract for a scientific paper: a simple systematic rule , inspired by high - temperature series expansion ( htse ) results , is proposed for optimizing the expression for thermodynamic observables of ferromagnets exhibiting critical behavior at @xmath0 . this `` extended scaling '' scheme leads to a protocol for the choice of scaling variables , @xmath1 or @xmath2 depending on the observable instead of @xmath3 , and more importantly to temperature dependent non - critical prefactors for each observable . the rule corresponds to scaling of the leading of the reduced susceptibility above @xmath0 as @xmath4 in agreement with standard practice with scaling variable @xmath5 , and for the leading term of the second - moment correlation length as @xmath6 . for the specific heat in bipartite lattices the rule gives @xmath7^{-\alpha}$ ] . the latter two expressions are not standard . the scheme can allow for confluent and non - critical correction terms . a stringent test of the extended scaling is made through analyses of high precision numerical and htse data , or _ real _ data , on the three - dimensional canonical ising , xy , and heisenberg ferromagnets . for the susceptibility @xmath8 and the correlation length @xmath9 of the three ferromagnets , their optimized expression , which consists of the leading term ( respectively @xmath10 and @xmath11 ) and a quite limited number of confluent and non - critical correction terms , represents _ real _ data to surprisingly good approximations over the entire temperature range from @xmath0 to infinity . the temperature dependent prefactors introduced are of crucial importance not only in fixing the optimized expression at relatively high temperatures but also in determining appropriately the small amplitude correction terms . for the specific heat of the ising ferromagnet , @xmath12 combined with two non - critical correction terms which are calculated with no free parameters once the correlation length critical parameters are known , reproduces _ real _ data nicely also over the whole.... And you have already written the first three sentences of the full article: at a continuous transition , the expression @xmath13 for the leading critical behavior of a thermodynamic observable @xmath14 has the well known form @xmath15 where @xmath0 and @xmath16 are the transition temperature and the critical exponent respectively . for the concrete analysis of numerical data , a normalization factor with non - critical behavior at @xmath0 must be introduced . the simplest and most traditional convention , which will be referred to below as @xmath17 scaling , is to normalize each @xmath18 by a temperature independent constant . for obvious reasons this constant. Please generate the next two sentences of the article

is chosen to be @xmath19 for each observable ; one then writes the normalized leading term as the familiar text - book expression : @xmath20^{-\rho_f } = { \cal c}_{f}t^{-\rho_f } , \label{t_scaling}\ ] ] where @xmath21 and @xmath22 is the critical amplitude ( see [ ] for a detailed review ) . an alternative and _ a priori _ equally valid choice is to write @xmath23^{-\rho_f } = { \cal c}_{f}[(t-\tc)/t]^{-\rho_f}\nonumber \\ & = & { \cal c}_{f}\left[1-\frac{\beta}{\bec}\right]^{-\rho_f } = { \cal c}_{f}\tau^{-\rho_f } , \label{beta_scaling}\end{aligned}\ ] ] where @xmath24 is the inverse temperature @xmath25 and @xmath26 .

Suppose that you have an abstract for a scientific paper: we have investigated the efficiency of pulsed raman sideband cooling in the presence of multiple decay and excitation channels . by applying sum rules we identify parameter regimes in which multiple scattering of photons can be described by an effective wave vector . using this method we determine the rate of heating caused by optical pumping inside and outside the lamb - dicke regime . on this basis we discuss also the efficiency of a recently proposed scheme for ground - state cooling outside the lamb - dicke regime [ g. morigi , j.i . cirac , m. lewenstein , and p. zoller , europhys . lett . * 39 * , 13 ( 1997 ) ] . . And you have already written the first three sentences of the full article: laser - cooling @xcite allows to cool ions and atoms to very low temperatures . for this purpose , the full knowledge of the effects of the various physical parameters determining the cooling process is very important . among the various schemes , raman sideband cooling has been demonstrated to be a very successful technique for preparing atoms in the ground state of a harmonic potential @xcite .. Please generate the next two sentences of the article

this cooling method exploits two stable or metastable atomic internal levels , which we call @xmath0 and @xmath1 , connected by dipole transitions to a common excited state @xmath2 . the transitions are usually driven by alternating pulses . a typical sequence alternates a coherent pulse , in which the atom is coherently transferred from @xmath0 to @xmath1 via a properly designed raman pulse , with a re - pumping pulse , in which the atom is incoherently re - scattered to @xmath0 by means of a laser resonant with @xmath3 .

Suppose that you have an abstract for a scientific paper: we report the detection of a feature at 65@xmath0 m and a broad feature around 100@xmath0 m in the far - infrared spectra of the diffuse emission from two active star - forming regions , and . the features are seen in the spectra over a wide area of the observed regions , indicating that the carriers are fairly ubiquitous species in the interstellar medium . a similar 65@xmath0 m feature has been detected in evolved stars and attributed to diopside , a ca - bearing crystalline silicate . the present observations indicate the first detection of a crystalline silicate in the interstellar medium if this identification holds true also for the interstellar feature . a similar broad feature around 90@xmath0 m reported in the spectra of evolved stars has been attributed to calcite , a ca - bearing carbonate mineral . the interstellar feature seems to be shifted to longer wavelengths and have a broader width although the precise estimate of the feature profile is difficult . as a carrier for the interstellar 100@xmath0 m feature , we investigate the possibility that the feature originates from carbon onions , grains consisting of curved graphitic shells . because of the curved graphitic sheet structure , the optical properties in the direction parallel to the graphitic plane interacts with those in the vertical direction in carbon onion grains . this effect enhances the interband transition feature in the direction parallel to the graphitic plane in carbon onions , which is suppressed in graphite particles . simple calculations suggest that carbon onion grains are a likely candidate for the observed 100@xmath0 m feature carrier , but the appearance of the feature is sensitive to the assumed optical properties . . And you have already written the first three sentences of the full article: infrared spectroscopy provides a crucial means in the identification of interstellar dust compositions . recent infrared satellite observations by the _ infrared telescope in space _ ( _ irts _ ; * ? ? ? * ) and the _ infrared space observatory _ ( _ iso _ ; * ? ? ?. Please generate the next two sentences of the article

* ) have revealed several new dust features in the diffuse emission , indicating the presence of new dust components in the interstellar medium @xcite . observations by _ iso _ also clearly show the presence of crystalline silicates around young and evolved stars for the first time @xcite , while it is not yet certain whether crystalline silicates exist commonly in interstellar space . in the present paper

Suppose that you have an abstract for a scientific paper: methods are set forth for determining the hadron electromagnetic structure in the sub-@xmath0-threshold timelike region of the virtual - photon `` mass '' and for investigating the nucleon weak structure in the spacelike region from experimental data on the process @xmath1 at low energies . these methods are formulated using the unified description of photoproduction , electroproduction , and inverse electroproduction of pions in the first resonance region in the framework of the dispersion - relation model and on the basis of the model - independent properties of inverse electroproduction . applications of these methods are also shown . . And you have already written the first three sentences of the full article: processes of meson electroproduction have played an important role in studying the structure and properties of matter ( see , _ e.g. _ review @xcite ) . in the past few years , however , reactions with production of dileptons in hadron - hadron and hadron - nucleus collisions have drawn much attention @xcite . in these reactions virtual photons , which materialize as dileptons ( _ e.g. _ , the @xmath2 pair ) , carry unique information on properties of matter because the processes in which the particle structure is formed proceed in the timelike region of the `` mass '' ( @xmath3 ) of the virtual photon . therefore , further investigation of these reactions is necessary and promising in acquisition of new and perhaps unexpected information about the form factors of hadrons and nuclei . the inverse pion electroproduction ( ipe ) , @xmath1 , ( or dileptonproduction ) , being for a long time the only source of information on the nucleon electromagnetic structure in the timelike region , has been investigated both theoretically @xcite and experimentally @xcite since the beginning of the 1960s . in refs . @xcite , we worked out the method of extracting the pion and nucleon electromagnetic form factors from ipe at low energies .. Please generate the next two sentences of the article

this method has been successfully applied in the analysis of experimental data on the nucleon and @xmath4c and @xmath5li nuclei @xcite and values of the form factors were obtained for the first time in the timelike region of @xmath3 ranging from 0.05 to 0.22 ( gev / c)@xmath6 . in refs . @xcite , the authors proposed to use ipe at intermediate ( above @xmath7 resonances ) energies and small @xmath8 to study the nucleon electromagnetic structure and justified it up to @xmath9 .

Suppose that you have an abstract for a scientific paper: we investigate the possible signature of the presence of giant pairing states at excitation energy of about 10 mev via two - particle transfer reactions induced by neutron - rich weakly - bound projectiles . performing particle - particle rpa calculations on @xmath0pb and bcs+rpa calculations on @xmath1sn , we obtain the pairing strength distribution for two particles addition and removal modes . estimates of two - particle transfer cross sections can be obtained in the framework of the macroscopic model. the weak - binding nature of the projectile kinematically favours transitions to high - lying states . in the case of @xmath2 reaction we predict a population of the giant pairing vibration with cross sections of the order of a millibarn , dominating over the mismatched transition to the ground state . . And you have already written the first three sentences of the full article: nuclei in interaction with external fields display a wide variety of collective vibrations known as giant resonances , associated with various degrees of freedom and multipolarities . the giant isovector dipole resonance and the giant isoscalar quadrupole resonance are the most studied examples in this class of phenomena . a particular mode , that is associated with vibrations in the number of particles , has been predicted in the 70s@xcite and discussed , under the name of giant pairing resonance , in the middle of the 80 s in a number of papers@xcite .. Please generate the next two sentences of the article

this phenomenon , despite some early efforts aimed to resolve some broad bump in the high - lying spectrum in ( p , t ) reactions@xcite , is still without any conclusive experimental confirmation . for a discussion , in particluar in connection with two - particle transfer reactions , on many aspects of pairing correlations in nuclei we refer to a recent review@xcite .

Suppose that you have an abstract for a scientific paper: the first observations by a worldwide network of advanced interferometric gravitational wave detectors offer a unique opportunity for the astronomical community . at design sensitivity , these facilities will be able to detect coalescing binary neutron stars to distances approaching , and neutron star - black hole systems to . both of these sources are associated with gamma ray bursts which are known to emit across the entire electromagnetic spectrum . gravitational wave detections provide the opportunity for `` multi - messenger '' observations , combining gravitational wave with electromagnetic , cosmic ray or neutrino observations . this review provides an overview of how australian astronomical facilities and collaborations with the gravitational wave community can contribute to this new era of discovery , via contemporaneous follow - up observations from the radio to the optical and high energy . we discuss some of the frontier discoveries that will be made possible when this new window to the universe is opened . binaries : close gravitational waves gamma - ray burst : general methods : observational supernovae : general stars : neutron . And you have already written the first three sentences of the full article: the detection of gravitational waves ( gws ) will rank as one of the major scientific achievements of this century . their detection will open up a new observational window to the universe , revealing dynamic sources of strong field relativistic gravity previously inaccessible through conventional astronomical instruments . our understanding of space - time and matter under the most extreme conditions will be transformed .. Please generate the next two sentences of the article

although there has been no direct detection of gws to date , indirect evidence for their existence comes from high precision , nobel - prize winning measurements of the pulsar psr 1913 + 16 and its companion neutron star ( ns ; * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: there is general agreement that the misataquwa equations should describe the motion of a small body " in general relativity , taking into account the leading order self - force effects . however , previous derivations of these equations have made a number of ad hoc assumptions and/or contain a number of unsatisfactory features . for example , all previous derivations have invoked , without proper justification , the step of `` lorenz gauge relaxation '' , wherein the linearized einstein equation is written down in the form appropriate to the lorenz gauge , but the lorenz gauge condition is then not imposed thereby making the resulting equations for the metric perturbation inequivalent to the linearized einstein equations . ( such a `` relaxation '' of the linearized einstein equations is essential in order to avoid the conclusion that `` point particles '' move on geodesics . ) in this paper , we analyze the issue of `` particle motion '' in general relativity in a systematic and rigorous way by considering a one - parameter family of metrics , @xmath0 , corresponding to having a body ( or black hole ) that is `` scaled down '' to zero size and mass in an appropriate manner . we prove that the limiting worldline of such a one - parameter family must be a geodesic of the background metric , @xmath1 . gravitational self - force as well as the force due to coupling of the spin of the body to curvature then arises as a first - order perturbative correction in @xmath2 to this worldline . no assumptions are made in our analysis apart from the smoothness and limit properties of the one - parameter family of metrics , @xmath0 . our approach should provide a framework for systematically calculating higher order corrections to gravitational self - force , including higher multipole effects , although we do not attempt to go beyond first order calculations here . the status of the misataquwa equations is explained . . And you have already written the first three sentences of the full article: the physical content of general relativity is contained in einstein s equation , which has a well - posed initial value formulation ( see , e.g. , @xcite ) . in principle , therefore , to determine the motion of bodies in general relativity such as binary neutron stars or black holes one simply needs to provide appropriate initial data ( satisfying the constraint equations ) on a spacelike slice and then evolve this data via einstein s equation . however , in practice , it is generally impossible to find exact solutions of physical interest describing the motion of bodies by analytic methods .. Please generate the next two sentences of the article

although it now is possible to find solutions numerically in many cases of interest , it is difficult and cumbersome to do so , and one may overlook subtle effects and/or remain unenlightened about some basic general features of the solutions . therefore , it is of considerable interest to develop methods that yield approximate descriptions of motion in some cases of interest . in general , the motion of a body of finite size will depend on the details of its composition as well as the details of its internal states of motion .

Suppose that you have an abstract for a scientific paper: we derive the schwinger - dyson equations for the @xmath0 yang - mills theory in the maximal abelian gauge and solve them in the infrared asymptotic region . we find that the infrared asymptotic solutions for the gluon and ghost propagators are consistent with the hypothesis of abelian dominance . . And you have already written the first three sentences of the full article: the schwinger - dyson ( sd ) equation is one of the most popular approaches to investigate the non - perturbative features of quantum field theory . the analyses by making use of the sd equation for quark propagator are well - known . recently , the coupled sd equations for the gluon and ghost propagators in yang - mills theory have been studied mainly in the lorentz ( landau ) gauge.@xcite in this paper , we derive the sd equations for the @xmath0 yang - mills theory in the maximal abelian ( ma ) gauge and solve them analytically in the infrared ( ir ) asymptotic region .. Please generate the next two sentences of the article

the ma gauge is useful to investigate the yang - mills theory from the view point of the dual superconductivity . in the ma gauge , in contrast to the ordinary lorentz gauge , we must explicitly distinguish the diagonal components of the fields from the off - diagonal components .

Suppose that you have an abstract for a scientific paper: in this paper , we consider modulation codes for practical multilevel flash memory storage systems with @xmath0 cell levels . instead of maximizing the lifetime of the device @xcite , we maximize the average amount of information stored per cell - level , which is defined as storage efficiency . using this framework , we show that the worst - case criterion @xcite and the average - case criterion @xcite are two extreme cases of our objective function . a self - randomized modulation code is proposed which is asymptotically optimal , as @xmath1 , for an arbitrary input alphabet and i.i.d . input distribution . in practical flash memory systems , the number of cell - levels @xmath0 is only moderately large . so the asymptotic performance as @xmath1 may not tell the whole story . using the tools from load - balancing theory , we analyze the storage efficiency of the self - randomized modulation code . the result shows that only a fraction of the cells are utilized when the number of cell - levels @xmath0 is only moderately large . we also propose a load - balancing modulation code , based on a phenomenon known as `` the power of two random choices '' @xcite , to improve the storage efficiency of practical systems . theoretical analysis and simulation results show that our load - balancing modulation codes can provide significant gain to practical flash memory storage systems . though pseudo - random , our approach achieves the same load - balancing performance , for i.i.d . inputs , as a purely random approach based on the power of two random choices . . And you have already written the first three sentences of the full article: information - theoretic research on capacity and coding for write - limited memory originates in @xcite , @xcite , @xcite and @xcite . in @xcite , the authors consider a model of write - once memory ( wom ) . in particular , each memory cell can be in state either 0 or 1 .. Please generate the next two sentences of the article

the state of a cell can go from 0 to 1 , but not from 1 back to 0 later . these write - once bits are called _ wits_. it is shown that , the efficiency of storing information in a wom can be improved if one allows multiple rewrites and designs the storage / rewrite scheme carefully .

Suppose that you have an abstract for a scientific paper: we present results from the mid - infrared spectral mapping of stephan s quintet using the _ spitzer space telescope_. a 1000km@xmath0 collision ( @xmath1yr ) has produced a group - wide shock and for the first time the large - scale distribution of warm molecular hydrogen emission is revealed , as well as its close association with known shock structures . in the main shock region alone we find 5.0 @xmath210@xmath3m@xmath4 of warm h@xmath5 spread over @xmath6480kpc@xmath7 and additionally report the discovery of a second major shock - excited h@xmath5 feature , likely a remnant of previous tidal interactions . this brings the total h@xmath5 line luminosity of the group in excess of @xmath8 . in the main shock , the h@xmath5 line luminosity exceeds , by a factor of three , the x - ray luminosity from the hot shocked gas , confirming that the h@xmath9-cooling pathway dominates over the x - ray . @xmath10siii@xmath11$]34.82emission , detected at a luminosity of 1/10th of that of the h@xmath9 , appears to trace the group - wide shock closely and in addition , we detect weak @xmath10feii@xmath11$]25.99 emission from the most x - ray luminous part of the shock . comparison with shock models reveals that this emission is consistent with regions of fast shocks ( @xmath12km@xmath0 ) experiencing depletion of iron and silicon onto dust grains . star formation in the shock ( as traced via ionic lines , pah and dust emission ) appears in the intruder galaxy , but most strikingly at either end of the radio shock . the shock ridge itself shows little star formation , consistent with a model in which the tremendous h@xmath5 power is driven by turbulent energy transfer from motions in a post - shocked layer which suppresses star formation . the significance of the molecular hydrogen lines over other measured sources of cooling in fast galaxy - scale shocks may have crucial implications for the cooling of gas in the assembly of the first galaxies . . And you have already written the first three sentences of the full article: stephan s quintet ( hereafter sq ) is a strongly interacting compact group which has produced a highly disturbed intragroup medium ( igm ) @xcite through a complex sequence of interactions and harrassment @xcite . this interplay has produced a large - scale intergalactic shock - wave , first observed as a narrow filament in the radio continuum @xcite , and subsequently detected in the x - ray @xcite . the high - velocity ( @xmath61000 km s@xmath13 ) collision of an intruder galaxy , ngc 7318b , with the intergalactic medium of the group @xcite is believed to be responsible for the shock - heating of the x - ray emitting gas .. Please generate the next two sentences of the article

optical emission line ratios and observed broad linewidths provide evidence that the region is powered by strong shocks and not star formation ( xu et al . 2003 ; duc et al . 2010 , in preparation ) .

Suppose that you have an abstract for a scientific paper: a ( non - circular ) de bruijn sequence @xmath0 of order @xmath1 is a word such that every word of length @xmath1 appears exactly once in @xmath0 as a factor . in this paper , we generalize the concept to a multi - shift setting : a @xmath2-shift de bruijn sequence of order @xmath1 is a word such that every word of length @xmath1 appears exactly once in @xmath0 as a factor that starts at an index @xmath3 for some integer @xmath4 . we show the number of the @xmath2-shift de bruijn sequences of order @xmath1 is @xmath5 for @xmath6 and is @xmath7 for @xmath8 , where @xmath9 is the size of the alphabet . we provide two algorithms for generating a multi - shift de bruijn sequence . the multi - shift de bruijn sequence is important in solving the frobenius problem in a free monoid . . And you have already written the first three sentences of the full article: if a word @xmath0 can be written as @xmath10 , then words @xmath11 , @xmath12 , and @xmath13 are called the prefix , factor , and suffix of @xmath0 , respectively . a word @xmath0 over @xmath14 is called a de bruijn sequence of order @xmath1 , if each word in @xmath15 appears exactly once in @xmath0 as a factor . for example , @xmath16 is a binary de bruijn sequence of order @xmath17 since each binary word of length two appears in it exactly once as a factor : @xmath18 .. Please generate the next two sentences of the article

the de bruijn sequence can be understood by the following game . suppose there are infinite supplies of balls , each of which is labeled by a letter in @xmath14 , and there is a glass pipe that can hold balls in a vertical line .

Suppose that you have an abstract for a scientific paper: transport measurements are presented on a quantum ring that is tunnel - coupled to a quantum dot . when the dot is in the coulomb blockade regime , but strongly coupled to the open ring , fano line shapes are observed in the current through the ring , when the electron number in the dot changes by one . the symmetry of the fano resonances is found to depend on the magnetic flux penetrating the area of the ring and on the strength of the ring dot coupling . at temperatures above t=0.65k the fano effect disappears while the aharonov bohm interference in the ring persists up to t=4.2k . good agreement is found between these experimental observations and a single - channel scattering matrix model including decoherence in the dot . . And you have already written the first three sentences of the full article: quantum rings and quantum dots are prototype systems for the observation of mesoscopic interference on the one hand and for spectroscopic investigations of discrete level spectra of interacting systems on the other hand . ring shaped structures give rise to aharonov bohm ( ab ) interference @xcite which can be tuned by applying a magnetic flux through the area enclosed by the ring . open ring geometries have been used as interferometers , e.g. , to study the transmission phase of quantum dots in the coulomb blockade ( cb ) regime.@xcite the discrete level spectrum of coulomb blockaded quantum dots has been extensively studied using tunneling spectroscopy to probe interaction and spin effects when a gate voltage is used to successively add electrons to such artificial atoms.@xcite and @xmath0 simultaneously and under symmetric bias conditions . @xmath1 reflects the transmission from the ring to the dot .. Please generate the next two sentences of the article

( c ) aharonov bohm oscillations in the two terminal ring conductance @xmath2 . ( d ) coulomb - blockade oscillations in the two - terminal dot conductance @xmath3 as a function of the in - plane gate voltage @xmath4 .

Suppose that you have an abstract for a scientific paper: it is not possible to disentangle a qubit in an _ unknown _ state @xmath0 from a set of @xmath1 ancilla qubits prepared in a specific reference state @xmath2 . that is , it is not possible to _ perfectly _ perform the transformation @xmath3 . the question is then how well we can do ? we consider a number of different methods of extracting an unknown state from an entangled state formed from that qubit and a set of ancilla qubits in an known state . measuring the whole system is , as expected , the least effective method . we present various quantum `` devices '' which disentangle the unknown qubit from the set of ancilla qubits . in particular , we present the _ optimal universal _ disentangler which disentangles the unknown qubit with the fidelity which does not depend on the state of the qubit , and a probabilistic disentangler which performs the perfect disentangling transformation , but with a probability less than one . * pacs number : 03.67.-a , 03.65.bz * 2 . And you have already written the first three sentences of the full article: information encoded in qubits can be used for reliable quantum communication or efficient quantum computing @xcite . this information is encoded in a quantum state @xmath4 which in the case of a qubit can be parameterized as |(,)= |0 + e^i |1 ; [ 1 ] where @xmath5 and @xmath6 are basis vectors of the 2-dimensional space of the qubit and @xmath7 ; @xmath8 . qubits are very fragile , that is the state of a qubit can easily be changed by the influence of the environment or a random error .. Please generate the next two sentences of the article

one ( very inefficient ) way to protect the quantum information encoded in a qubit is to measure it . with the help of an optimal measurement one can estimate the state of a qubit , with an average fidelity equal to 2/3 ( see below ) . in this way a quantum information is transformed into a classical information which can be stored , copied , and processed according the laws of classical physics with arbitrarily high precision .

Suppose that you have an abstract for a scientific paper: the analysis of the recent charged - current neutrino - nucleus scattering cross sections measured by the argoneut collaboration requires relativistic theoretical descriptions also accounting for the role of final - state interactions . in this work , we evaluate differential neutrino - nucleus cross sections with the relativistic green s function model , where final - state interactions are described in the inclusive scattering consistently with the exclusive scattering using a complex optical potential . the sensitivity to the parameterization adopted for the phenomenological optical potential is discussed . the predictions of the relativistic green s function model are compared with the results of different descriptions of final - state interactions . . And you have already written the first three sentences of the full article: in the past decade many neutrino oscillation results have been presented by different collaborations @xcite , and a phenomenological extension of the standard model has been proposed that involves three neutrino mass states , over which the three flavors of neutrinos are distributed . despite its successful predictions , this can be considered as an extension of the standard model that does not address fundamental questions , e.g. , small masses and large mixing angles compared to quark sector , and has raised a large debate over other possible unexpected properties of neutrinos that could lead to a more complete understanding of neutrino physics @xcite . to gain a deeper understanding of neutrino phenomenology the reduction of uncertainties in baseline neutrino oscillation experiments is mandatory . because of the interest in oscillation measurements , in recent years various neutrino - nucleus differential cross sections have been presented @xcite and are planned in the near future @xcite .. Please generate the next two sentences of the article

differential cross sections are important to obtain a complete kinematical determination of neutrino - nucleus scattering and a clear understanding of neutrino - nucleus reactions is crucial for the analysis of experimental measurements . the argoneut collaboration has recently reported @xcite a measurement of the muon neutrino charged - current ( cc ) flux - averaged differential cross section on @xmath0ar in an energy range up to 50 gev . a liquid argon detector is very interesting because it has excellent potentialities to make precise measurements of a very large class of neutrino interactions from the mev energy scale to multi - gev events @xcite .

Suppose that you have an abstract for a scientific paper: analyses of primitive meteorites and cometary samples have shown that the solar nebula must have experienced a phase of large - scale outward transport of small refractory grains as well as homogenization of initially spatially heterogeneous short - lived isotopes . the stable oxygen isotopes , however , were able to remain spatially heterogenous at the @xmath0 6% level . one promising mechanism for achieving these disparate goals is the mixing and transport associated with a marginally gravitationally unstable ( mgu ) disk , a likely cause of fu orionis events in young low - mass stars . several new sets of mgu models are presented that explore mixing and transport in disks with varied masses ( 0.016 to 0.13 @xmath1 ) around stars with varied masses ( 0.1 to 1 @xmath1 ) and varied initial @xmath2 stability minima ( 1.8 to 3.1 ) . the results show that mgu disks are able to rapidly ( within @xmath3 yr ) achieve large - scale transport and homogenization of initially spatially heterogeneous distributions of disk grains or gas . in addition , the models show that while single - shot injection heterogeneity is reduced to a relatively low level ( @xmath0 1% ) , as required for early solar system chronometry , continuous injection of the sort associated with the generation of stable oxygen isotope fractionations by uv photolysis leads to a sustained , relatively high level ( @xmath0 10% ) of heterogeneity , in agreement with the oxygen isotope data . these models support the suggestion that the protosun may have experienced at least one fu orionis - like outburst , which produced several of the signatures left behind in primitive chondrites and comets . . And you have already written the first three sentences of the full article: the short - lived radioisotope ( slri ) @xmath4al was alive during the formation of the first refractory solids in the solar nebula , the ca- , al - rich inclusions ( cais ) found in primitive chondritic meteorites . this means that at least some of the solar system s slris may have been injected into either the presolar cloud ( e.g. , boss & keiser 2012 ; boss 2012 ) or the solar nebula ( ouellette et al . 2007 , 2010 ; dauphas & chaussidon 2011 ) by a supernova or agb star shock wave . in either case , injection occurred as a single event that was spatially heterogeneous , which would potentially reduce the usefulness of @xmath4al as a spatially homogeneous chronometer ( dauphas & chaussidon 2011 ) for precise studies of the earliest phases of planet formation ( macpherson et al .. Please generate the next two sentences of the article

2012 ; cf . krot et al .

Suppose that you have an abstract for a scientific paper: we calculate the josephson current between two one - dimensional ( 1d ) nanowires oriented along @xmath0 with proximity induced @xmath1-wave superconducting pairing and separated by a narrow dielectric barrier in the presence of both rashba spin - orbit interaction ( soi ) characterized by strength @xmath2 and zeeman fields ( @xmath3 along @xmath4 and @xmath5 in the @xmath6 plane ) . we formulate a general method for computing the andreev bound states energy which allows us to obtain analytical expressions for the energy of these states in several asymptotic cases . we find that in the absence of the magnetic fields the energy gap between the andreev bound states decreases with increasing rashba soi constant leading eventually to touching of the levels . in the absence of rashba soi , the andreev bound states depend on the magnetic fields and display oscillatory behavior with orientational angle of b leading to magneto - josephson effect . we also present analytic expressions for the dc josephson current charting out their dependence on @xmath5 , @xmath3 , and @xmath2 . we demonstrate the existence of finite spin - josephson current in these junctions in the presence of external magnetic fields and provide analytic expressions for its dependence on @xmath2 , @xmath7 and @xmath3 . finally , we study the ac josephson effect in the presence of the soi ( for @xmath8 ) and an external radiation and show that the width of the resulting shapiro steps in such a system can be tuned by varying @xmath2 . we discuss experiments which can test our theoretical results . . And you have already written the first three sentences of the full article: a recent idea on possible application of topological superconductors to quantum information processing has attracted both theoretical and experimental interest @xcite . according to this idea , a quantum information unit , qubit , can be formed and propagated by means of majorana mode ( see , for e.g. , ref . ) , localized at the end of a one - dimensional ( 1d ) chain hosting a topological superconductor @xcite . recent investigations suggest several detection mechanisms of such a majorana mode @xcite such as an existence of a central peak in the tunneling current through a topological superconductor ( s)- normal metal ( n)junction and fractional period of the josephson current in s - n - s junctions . most recently experimental systems involving 1d semiconductor wire has been shown to host such modes ; the mechanism of the appearance of such modes arise from the combination of strong soi , proximity - induced superconducting gap , chemical potential and applied zeeman field in these wires @xcite .. Please generate the next two sentences of the article

two majorana modes in the josephson junction , formed between two topological insulator edges or one - dimensional superconducting nanowires separated by barrier , hybridize resulting in splitting of the zero energy modes . this splitting energy depends not only on the phase difference of the two superconductors but also on the relative direction of the spin polarization at the two side of the junction .

Suppose that you have an abstract for a scientific paper: we discuss the mechanism of cluster formation in a numerical simulation of a molecular cloud ( mc ) undergoing global hierarchical collapse ( ghc ) , to understand how the gas motions in the parent cloud control the assembly of the cluster . the global nature of the collapse implies that the star formation rate ( sfr ) increases over time . the `` hierarchical '' nature of the collapse consists of small - scale collapses within larger - scale ones . the large - scale collapses culminate a few myr later than the small - scale collapses and consist of filamentary flows that accrete onto massive , dense central clumps . in turn , the small - scale collapses form clumps embedded in the filaments , that are falling onto the central clump assembled by the ongoing large - scale collapse . the stars formed in the early , small - scale collapses share the infall motion of their parent clumps towards the larger - scale potential well , so that the filaments feed both gaseous and stellar material to the massive central clump . this leads to the presence of a few older stars in a region where new protostars are forming at a higher rate , and also to a self - similar or fractal - like structure of the clusters , in which each unit is composed of smaller - scale sub - units , which approach each other and may eventually merge , explaining the frequently - observed morphology of cluster - forming regions . moreover , because the older stars formed in the filaments share the infall motion of the gas onto the central clump , they tend to have larger velocities and to be distributed over larger areas than the younger stars formed in the central clump , where the gas from which they form has been shocked and has dissipated some kinetic energy . finally , interpreting the imf as a probability distribution , so that the probability of forming a massive star is much lower than that of forming a low - mass one , implies that massive stars only form once the _ local _ sfr is large enough to sample the imf up to high.... And you have already written the first three sentences of the full article: it is presently accepted that most stars form in clusters or groups , although the details of the cluster - formation process , especially the origin of their structural properties , remain a matter of active research ( see , e.g. , the reviews by * ? ? ? * ; * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

in particular , in recent years , a number of structural properties of the clusters have been uncovered that still require an adequate theoretical understanding , such as : i ) the existence of a mass segregation in the clusters , with the most massive stars lying closer to the cluster s center @xcite ; ii ) the distribution of protostellar separations , which appears to have no characteristic scale @xcite ; iii ) the likely existence of an age gradient in clusters , with the youngest stars being located in the highest - density regions @xcite ; iv ) the apparent deficit of ob stars in some infrared dark clouds . numerical simulations have begun to offer some insight about these properties .

Suppose that you have an abstract for a scientific paper: we present three searches for new particles at cdf . first , using 70 pb@xmath0 of data we search the dijet mass spectrum for resonances . there is an upward fluctuation near 550 gev / c@xmath1 ( 2.6@xmath2 ) with an angular distribution that is adequately described by either qcd alone or qcd plus 5% signal . there is insufficient evidence to claim a signal , but we set the most stringent mass limits on the hadronic decays of axigluons , excited quarks , technirhos , w@xmath3 , z@xmath3 , and e6 diquarks . second , using 19 pb@xmath0 of data we search the b - tagged dijet mass spectrum for @xmath4 resonances . again , an upward fluctuation near 600 gev / c@xmath1 ( 2 @xmath2 ) is not significant enough to claim a signal , so we set the first mass limits on topcolor bosons . finally , using 67 pb@xmath0 of data we search the top quark sample for @xmath5 resonances like a topcolor @xmath6 . other than an insignificant shoulder of 6 events on a background of 2.4 in the mass region 475 - 550 gev / c@xmath1 , there is no evidence for new particle production . mass limits , currently in progress , should be sensitive to a topcolor z@xmath3 near 600 gev / c@xmath1 . in all three searches there is insufficient evidence to claim new particle production , yet there is an exciting possibility that the upward fluctuations are the first signs of new physics beyond the standard model . fermilab - conf-95/152-e + cdf / pub / exotic / public/3192 + + * search for new particles decaying to dijets , + @xmath4 , and @xmath5 at cdf + * _ fermilab ms 318 + batavia , il 60510 + _ . And you have already written the first three sentences of the full article: as in our previous analysis of run 1a data @xcite , we conduct a general search for new particles with a narrow natural width that decay to dijets . in addition , we search for the following particles summarized in fig . [ fig_particles ] : axigluons @xcite from chiral qcd ( @xmath7 ) , excited states @xcite of composite quarks ( @xmath8 ) , color octet technirhos @xcite ( @xmath9 ) , new gauge bosons ( @xmath10,@xmath11 ) , and scalar @xmath12 diquarks @xcite ( @xmath13 and @xmath14 ) .. Please generate the next two sentences of the article

using four triggers from run 1a and 1b , we combine dijet mass spectra above a mass of 150 gev / c@xmath1 , 241 gev / c@xmath1 , 292 gev / c@xmath1 , and 388 gev / c@xmath1 with integrated luminosities of = 7.5 in = 3.3 in = 3.3 in .089 pb@xmath0 , 1.92 pb@xmath0 , 9.52 pb@xmath0 , and 69.8 pb@xmath0 respectively . jets are defined with a fixed cone clustering algorithm ( r=0.7 ) and then corrected for detector response , energy lost outside the cone , and underlying event .

Suppose that you have an abstract for a scientific paper: we review the theory and observations of star cluster disruption . the three main phases and corresponding typical timescales of cluster disruption are : _ i ) infant mortality _ ( @xmath0 yr ) , _ ii ) stellar evolution _ ( @xmath1 yr ) and _ iii ) tidal relaxation _ ( @xmath2 yr ) . during all three phases there are additional tidal external perturbations from the host galaxy . in this review we focus on the physics and observations of phase i and on population studies of phases ii & iii and external perturbations ( concentrating on cluster - gmc interactions ) . particular attention is given to the successes and short - comings of the lamers cluster disruption law , which has recently been shown to stand on a firm physical footing . . And you have already written the first three sentences of the full article: the vast majority ( perhaps all ) of stars are formed in a clustered fashion . however , only a very small percentage of older stars are found in bound clusters . these two observations highlight the importance of clusters in the star - formation process and the significance of cluster disruption . the process of cluster disruption begins soon after , or concurrent with , cluster formation .. Please generate the next two sentences of the article

@xcite found that @xmath3 of stars formed in embedded clusters end up in bound clusters after @xmath4 yr . @xcite and @xcite have shown that at least 20% , but perhaps all , star formation in the merging antennae galaxies is taking place in clusters , the majority of which are likely to become unbound .

Suppose that you have an abstract for a scientific paper: ergodic homeomorphisms @xmath0 and @xmath1 of polish probability spaces @xmath2 and @xmath3 are _ evenly kakutani equivalent _ if there is an orbit equivalence @xmath4 between full measure subsets of @xmath2 and @xmath3 such that , for some @xmath5 of positive measure , @xmath6 restricts to a measurable isomorphism of the induced systems @xmath7 and @xmath8 . the study of even kakutani equivalence dates back to the seventies , and it is well known that any two zero - entropy loosely bernoulli systems are evenly kakutani equivalent . but even kakutani equivalence is a purely measurable relation , while systems such as the morse minimal system are both measurable and topological . recently del junco , rudolph and weiss studied a new relation called _ nearly continuous kakutani equivalence_. a nearly continuous kakutani equivalence is an even kakutani equivalence where also @xmath9 and @xmath10 are invariant @xmath11 sets , @xmath12 is within measure zero of both open and closed , and @xmath6 is a homeomorphism from @xmath9 to @xmath10 . it is known that nearly continuous kakutani equivalence is strictly stronger than even kakutani equivalence , and nearly continuous kakutani equivalence is the natural strengthening of even kakutani equivalence to the _ nearly continuous _ category the category where maps are continuous after sets of measure zero are removed . in this paper we show that the morse minimal substitution system is nearly continuously kakutani equivalent to the binary odometer . . And you have already written the first three sentences of the full article: even kakutani equivalence is one of the most natural examples in the theory of restricted orbit equivalence of ergodic and finite measure preserving dynamical systems . in this paper we study even kakutani equivalence in the nearly continuous category . a nearly continuous dynamical system is given by a triple @xmath13 , where @xmath2 is a polish space , @xmath14 is a borel probability measure on @xmath2 , and @xmath15 is an ergodic measure preserving homeomorphism . recall that a measurable orbit equivalence between two such systems @xmath13 and @xmath16 is an invertible , bi - measurable , and measure preserving map @xmath17 that sends orbits to orbits . a measurable orbit equivalence @xmath18 is a _ nearly continuous orbit equivalence _ if there exist invariant and @xmath11 subsets @xmath19 and @xmath20 of full measure so that @xmath21 is a homeomorphism .. Please generate the next two sentences of the article

the first result in this category is the celebrated theorem of keane and smorodinsky @xcite that any two bernoulli shifts of equal entropy are finitarily isomorphic , namely , that the isomorphism between them can be made a homeomorphism almost everywhere . in a later paper , denker and keane @xcite established a general framework for studying measure preserving systems that also preserve a topological structure .

Suppose that you have an abstract for a scientific paper: we used the magneto - dipole radiation mechanism for the braking of radio pulsars to calculate the new values of magnetic inductions at the surfaces of neutron stars . for this aim we estimated the angles @xmath0 between the rotation axis and the magnetic moment of the neutron star for 376 radio pulsars using three different methods . it was shown that there was the predominance of small inclinations of the magnetic axes . using the obtained values of the angle @xmath0 we calculated the equatorial magnetic inductions for pulsars considered . these inductions are several times higher as a rule than corresponding values in the known catalogs . * keywords * magnetic fields ; methods : data analysis ; methods : statistical ; _ ( stars : ) _ pulsars : general . And you have already written the first three sentences of the full article: it is common accepted that braking of pulsars is caused by the magneto - dipole radiation of the rotating magnetic star . in this case the rate of losses of the neutron star rotation energy can be equated to the power of its magneto - dipole radiation : @xmath1 + where _ i _ is the moment of inertia of the neutron star , @xmath2 - the angular speed of its rotation , @xmath3 - its magnetic moment , @xmath0 - the angle between the rotation axis and the magnetic moment , _ c _ - speed of light . for standard parameters of neutron stars : masses of order of the solar mass ( @xmath4 ) and radii _ r _ of order of @xmath5 cm we can put _ i _ = @xmath6 . for the magnetic moment we have @xmath7 + here @xmath8 is the magnetic induction at the magnetic pole , @xmath9 ?. Please generate the next two sentences of the article

the induction at the magnetic equator . instead of @xmath2 the rotation period @xmath10 is usually measured and we can obtain from ( 1 ) and ( 2 ) : @xmath11 + this equality is used usually to calculate magnetic inductions of pulsars assuming that @xmath12 for all objects . the known catalogs ( see , for example manchester et al

Suppose that you have an abstract for a scientific paper: the scattering processes of exotic atoms in excited states from hydrogen such as elastic scattering , stark transitions and coulomb de - excitation are studied within a close coupling approach . the vacuum polarization and the strong interaction shifts of @xmath0-states ( in case of hadronic atoms ) are taken into account . the differential and integral cross sections of the above processes are calculated to use them as the input in cascade calculations . the effect of closed channels on the scattering processes is investigated . * scattering processes of excited exotic atoms : close - coupling approach * + _ institute of nuclear physics , moscow state university , 119992 moscow , russia@xmath1 institution1 _ . And you have already written the first three sentences of the full article: the exotic hydrogen like atoms are formed in highly excited states , when negative particles ( @xmath2 ) are stopped in hydrogen . the deexcitation of exotic atoms proceeds via many intermediate states until the ground state is reached or a nuclear reaction takes place . despite a long history of theoretical and experimental studies the kinetics of this atomic cascade is not yet fully understood . the present experiments with the exotic hydrogen - like atoms addresses a number of fundamental problems using precision spectroscopy methods , the success of which relies crucially on a better knowledge of the atomic cascade .. Please generate the next two sentences of the article

the experimental data are mainly appropriate to the processes at the last stage of the atomic cascade ( x - ray yields and the products of the weak or strong interaction of the exotic particle in the low angular momentum states with hydrogen isotopes ) . so the reliable theoretical backgrounds on the processes both in low - lying and in highly excited states are required for the detailed and proper analysis of the experimental data .

Suppose that you have an abstract for a scientific paper: we examine the effects of pre - processing across the coma supercluster , including 3505 galaxies over @xmath0500 deg@xmath1 , by quantifying the degree to which star - forming ( sf ) activity is quenched as a function of environment . we characterise environment using the complementary techniques of voronoi tessellation , to measure the density field , and the minimal spanning tree , to define continuous structures , and so we measure sf activity as a function of local density _ and _ the type of environment ( cluster , group , filament , and void ) , and quantify the degree to which environment contributes to quenching of sf activity . our sample covers over two orders of magnitude in stellar mass ( 10@xmath2 to 10@xmath3 ) , and consequently we trace the effects of environment on sf activity for dwarf and massive galaxies , distinguishing so - called ` mass quenching ' from ` environment quenching ' . environmentally - driven quenching of sf activity , measured relative to the void galaxies , occurs to progressively greater degrees in filaments , groups , and clusters , and this trend holds for dwarf and massive galaxies alike . a similar trend is found using @xmath4 colours , but with a more significant disparity between galaxy mass bins driven by increased internal dust extinction in massive galaxies . the sfr distributions of massive sf galaxies have no significant environmental dependence , but the distributions for dwarf sf galaxies are found to be statistically distinct in most environments . pre - processing plays a significant role at low redshift , as environmentally - driven galaxy evolution affects nearly half of the galaxies in the group environment , and a significant fraction of the galaxies in the more diffuse filaments . our study underscores the need for sensitivity to dwarf galaxies to separate mass - driven from environmentally - driven effects , and the use of unbiased tracers of sf activity . [ firstpage ] galaxies : clusters : general galaxies : evolution .... And you have already written the first three sentences of the full article: studies of massive galaxy clusters and groups at @xmath5 typically find environments with little - to - no star formation activity , in sharp contrast with the field . over - dense regions are dominated by red , passively - evolving s0 and elliptical galaxies , whereas more sparsely - populated regions tend to have galaxies with spiral morphologies , younger stellar populations , and systematically higher star formation rates @xcite . an observed trend of increasing blue galaxy fraction with redshift ( the butcher - oemler effect ; * ? ? ?. Please generate the next two sentences of the article

* ) has been interpreted as evidence for higher star formation activity and stellar mass build - up in higher redshift clusters or alternatively , that star formation is quenched more recently by one or more processes in over - dense regions . several physical mechanisms can account for the quenching of star formation in over - dense regions ( for a review , see * ? ? ?

Suppose that you have an abstract for a scientific paper: doppler measurements of the m4 dwarf star , gliese 876 , taken at both lick and keck observatory reveal periodic , keplerian velocity variations with a period of 61 days . the orbital fit implies that the companion has a mass of , @xmath0 = 2.1 m@xmath1 , an orbital eccentricity of , @xmath2 = [email protected] , and a semimajor axis of , @xmath4 = 0.21 au . the planet is the first found around an m dwarf , and was drawn from a survey of 24 such stars at lick observatory . it is the closest extrasolar planet yet found , providing opportunities for follow up detection . the presence of a giant planet on a non - circular orbit , 0.2 au from a 1/3 m@xmath5 star , presents a challenge to planet formation theory . this planet detection around an m dwarf suggests that giant planets are numerous in the galaxy . . And you have already written the first three sentences of the full article: precise doppler surveys of main sequence stars have revealed eight companions that have masses under 5 m@xmath6/ @xmath7 , with the orbital inclination , @xmath8 , remaining unknown ( mayor et al . 1999 , marcy & butler 1998 , noyes et al . 1997 , cochran et al .. Please generate the next two sentences of the article

1997 ) . these `` planetary '' companions exhibit both circular and eccentric orbits , consistent with formation in dissipative circumstellar disks , followed by gravitational perturbations ( cf . lin et al . 1995 , artymowicz 1997 , levison et al . 1998 ) .

Suppose that you have an abstract for a scientific paper: the aim of this paper is to define a chain level refinement of the batalin - vilkovisky ( bv ) algebra structure on homology of the free loop space of a closed @xmath0-manifold . namely , we propose a new chain model of the free loop space , and define an action of a certain chain model of the framed little disks operad on it , recovering the original bv structure on homology level . we also compare this structure to a solution of deligne s conjecture for hochschild cochain complexes of differential graded algebras . to define the chain model of the loop space , we introduce a notion of de rham chains , which is a hybrid of singular chains and differential forms . . And you have already written the first three sentences of the full article: let us begin with the following facts : 1 . for any differential graded algebra @xmath1 , the hochschild cohomology @xmath2 has a gerstenhaber algebra structure . 2 . let @xmath3 be a closed , oriented @xmath4-dimensional @xmath0-manifold , @xmath5 be the free loop space .. Please generate the next two sentences of the article

then , @xmath6 has a batalin - vilkovisky ( in particular , gerstenhaber ) algebra structure . 3 . let @xmath7 denote the differential graded algebra of differential forms on @xmath3 .

Suppose that you have an abstract for a scientific paper: the gravitational waves generated during supermassive black hole ( smbh ) coalescence are prime candidates for detection by the satellite lisa . we use the extended press - schechter formalism combined with empirically motivated estimates for the smbh dark matter halo mass relation and smbh occupation fraction to estimate the maximum coalescence rate for major smbh mergers . assuming efficient binary coalescence , and guided by the lowest nuclear black hole mass inferred in local galactic bulges and nearby low - luminosity active galactic nuclei ( @xmath0 m@xmath1 ) we predict approximately 15 detections per year at a signal to noise greater than five , in each of the inspiral and ringdown phases . rare coalescences between smbhs having masses in excess of @xmath2 m@xmath1 will be more readily detected via gravitational waves from the ringdown phase . [ firstpage ] black hole physics , cosmology : theory , gravitational waves . And you have already written the first three sentences of the full article: there is evidence for the existence of supermassive black holes ( smbhs ) over a range of epochs ; smbhs with masses @xmath3 m@xmath1 are ubiquitous in local galactic bulges ( e.g. magorrian et al . 1998 : ferrarese 2002 ) , while the smbhs powering quasars [ which have been detected at redshifts as high as @xmath4 ( fan et al . 2001 ; fan et al . 2003 ) ] are estimated to range between @xmath5 m@xmath1 ( see e.g. shields et al . evidence for the early assembly of smbhs , when interpreted within a hierarchical cosmology , suggests that smbh coalescence may be a frequent event . if this is the case , the gravitational waves ( gws ) generated during smbh coalescence are a prime candidate for detection by the _ laser interferometer space antennae _. Please generate the next two sentences of the article

( lisa , folkner et al . 1998 ; flanagan & hughes 1998 ; hughes et al .

Suppose that you have an abstract for a scientific paper: in the @xmath0-@xmath1vc problem , we are given an undirected graph @xmath2 with edge costs and an integer @xmath0 ; the goal is to find a minimum - cost 2-vertex - connected subgraph of @xmath2 containing at least @xmath0 vertices . a slightly more general version is obtained if the input also specifies a subset @xmath3 of _ terminals _ and the goal is to find a subgraph containing at least @xmath0 terminals . closely related to the @xmath0-@xmath1vc problem , and in fact a special case of it , is the @xmath0-@xmath1ec problem , in which the goal is to find a minimum - cost 2-edge - connected subgraph containing @xmath0 vertices . the @xmath0-@xmath1ec problem was introduced by lau _ et al . _ @xcite , who also gave a poly - logarithmic approximation for it . no previous approximation algorithm was known for the more general @xmath0-@xmath1vc problem . we describe an @xmath4 approximation for the @xmath0-@xmath1vc problem . . And you have already written the first three sentences of the full article: connectivity and network design problems play an important role in combinatorial optimization and algorithms both for their theoretical appeal and their many real - world applications . an interesting and large class of problems are of the following type : given a graph @xmath5 with edge or node costs , find a minimum - cost subgraph @xmath6 of @xmath2 that satisfies certain connectivity properties . for example , given an integer @xmath7 , one can ask for the minimum - cost spanning subgraph that is @xmath8-edge or @xmath8-vertex connected . if @xmath9 then this is the classical minimum spanning tree ( mst ) problem . for @xmath10 the problem is np - hard and also apx - hard to approximate .. Please generate the next two sentences of the article

more general versions of connectivity problems are obtained if one seeks a subgraph in which a subset of the nodes @xmath11 referred to as _ terminals _ are @xmath8-connected . the well - known steiner tree problem is to find a minimum - cost subgraph that ( @xmath12-)connects a given set @xmath13 .

Suppose that you have an abstract for a scientific paper: we study the corrections to higgs physics in a model of a single warped extra dimension with all fields except the higgs in the bulk , and a gauge symmetry extended to @xmath0 . we find that generically the higgs coupling to electroweak gauge boson pairs is suppressed , the coupling to gluons is enhanced , and the coupling to photons is often suppressed , but can be enhanced . . And you have already written the first three sentences of the full article: one of the most promising solutions to the hierarchy problem is the randall - sundrum ( rs ) model @xcite . in this model there is a single extra dimension compactified on @xmath1 with the non - factorizable metric of @xmath2 @xmath3 here @xmath4 is the extra - dimensional coordinate , and @xmath5 is the inverse of the @xmath6 curvature , @xmath7 . two branes define the boundaries of the extra dimension .. Please generate the next two sentences of the article

one , at @xmath8 , is called the uv , or planck , brane . the other , at @xmath9 , is the ir , or tev , brane . picking @xmath10 , which is natural in realistic stabilization mechanisms ,

Suppose that you have an abstract for a scientific paper: the notion that microparsec - scale black holes can be used to probe gigaparsec - scale physics may seem counterintuitive , at first . yet , the gravitational observatory _ lisa _ will detect cosmologically - distant coalescing pairs of massive black holes , accurately measure their luminosity distance and help identify an electromagnetic counterpart or a host galaxy . a wide variety of new black hole studies and a gravitational version of hubble s diagram become possible if host galaxies are successfully identified . furthermore , if dark energy is a manifestation of large - scale modified gravity , deviations from general relativistic expectations could become apparent in a gravitational signal propagated over cosmological scales , especially when compared to the electromagnetic signal from a same source . finally , since inspirals of white dwarfs into massive black holes at cosmological distances may permit pre - merger localizations , we suggest that careful monitoring of these events and any associated electromagnetic counterpart could lead to high - precision cosmological measurements with _ lisa_. . And you have already written the first three sentences of the full article: essentially all astronomical measurements are performed via electromagnetic waves . the availability of accurate gravitational wave measurements within the next decade or so will thus be a significant development for astronomy . in particular , since the propagation of photons and gravitons could differ at a fundamental level , gravitational waves emitted by cosmologically - distant `` space - time sirens , '' such as coalescing pairs of massive black holes , could be used as valuable new probes of physics on cosmological scales .. Please generate the next two sentences of the article

black holes with masses @xmath0 are present at the center of numerous nearby galaxies ( e.g. * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: sdssj094857.3 + 002225 is a very radio - loud narrow - line seyfert 1 ( nls1 ) galaxy . here , we report our discovery of the intranight optical variability ( inov ) of this galaxy through the optical monitoring in the _ b _ and _ r _ bands that covered seven nights in 2009 . violent rapid variability in the optical bands was identified in this rl - nls1 for the first time , and the amplitudes of the inov reaches 0.5 mag in both the _ b _ and _ r _ bands on the timescale of several hours . the detection of the inov provides a piece of strong evidence supporting the fact that the object carries a relativistic jet with a small viewing angle , which confirms the conclusion drawn from the previous multi - wavelength studies . . And you have already written the first three sentences of the full article: narrow - line seyfert 1 galaxies ( nls1s ) are a special and interesting group of active galactic nuclei ( agns ) . they show narrow optical balmer emission lines [ fwhm(h@xmath0 ) @xmath1 2000 km s@xmath2 , weak [ ] @xmath35007 emission ( [ ] /h@xmath4 ) , strong emission , and soft x - ray excess @xcite . nls1s show remarkable radio - loud / radio - quiet bimodality @xcite .. Please generate the next two sentences of the article

only @xmath5 of nls1s are radio - loud objects @xcite . the fraction is much smaller than that found in qsos .

Suppose that you have an abstract for a scientific paper: we compute the quasi - normal ( qn ) frequencies for the regular bardeen de sitter ( bds ) black hole due to massless and massive scalar field perturbations as well as the massless dirac perturbations . we analyze the behaviour of both real and imaginary parts of quasinormal frequencies by varying the black hole parameters . . And you have already written the first three sentences of the full article: in the study of physics , the stability criteria of a system or configuration is one of the main interesting aspects . unstable system or configurations are generally not realizable in nature and they are generally an intermediate stage in the dynamical evolution of a system . a black hole system in general relativity can also be put in the above mentioned category : the question one asks there is whether a black hole which is stable under some perturbation , i.e. if we perturb the black hole from outside , whether it comes back to its original state after some time or whether the perturbation grows unbound making the black hole unstable . the study of black hole perturbations remains an extremely intriguing topic which has enormous effect on various important properties of a black hole @xcite .. Please generate the next two sentences of the article

in general , the dynamical evolution of perturbations of a black hole background can be classified into three stages , the first of which consists of an initial outburst of wave , depending completely on the initial perturbing field , the second stage consists of damped oscillations , known in the literature as the quasinormal modes ( qnm ) whose frequency turns out to be a complex number , the real part representing the oscillation frequency and the imaginary part representing damping . qn frequencies completely depend on the background and not on the field which is causing the perturbation and thereby giving immense importance to these modes which are used to determine the black hole parameters ( mass , charge and angular momentum ) .

Suppose that you have an abstract for a scientific paper: we propose using a single magneto - dielectric microsphere as a device for enhancing the transverse faraday effect at multiple wavelengths at the same time . although the diameter of the sphere can be @xmath0 @xmath1 m , the numerically predicted strength of its magneto - optical ( mo ) response can be an order of magnitude stronger than in mo devices based on thick magnetic plates . the mo response of a microsphere is also comparable with that of subwavelength magneto - dielectric gratings which , however , operate at a single wavelength and occupy a large area . in contrast to gratings and thick plates , the compact size of the microsphere and its capability to support spin - wave excitations make it suitable for applications in nanophotonics , imaging systems , and magnonics . . And you have already written the first three sentences of the full article: magneto - optical ( mo ) effects have found important applications in data storage , telecommunications , imaging , spectroscopy,@xcite as well as in magnonics . @xcite an increasingly broad application of nanotechnologies in these areas sets new requirements for novel mo devices by demanding , among other things , a stronger mo response and smaller dimensions . for example , small dimensions are important for @xmath2d imaging systems based on holographic principles.@xcite such systems require a spatial light modulator ( slm ) a device used to modulate amplitude , phase , or polarisation of light waves in space and time .. Please generate the next two sentences of the article

basically , an slm device can produce high quality @xmath2d images if it possesses pixels sizes @xmath3 @xmath1 m and also is fast enough to address a large number of pixels within a single image frame . slm devices exploiting mo effects have a very fast response time . however , their typical pixel sizes are @xmath4 @xmath1m.@xcite at the nanoscale , mo effects can be enhanced by using subwavelength diffraction gratings @xcite , magneto - photonic crystals , @xcite and nanoantennas , @xcite which are made of pure magnetic materials or consist of alternating magnetic - nonmagnetic layers . however , as a typical grating period is @xmath5 nm and there should be tens of periods to achieve optimal optical properties , the footprint of the grating is large .

Suppose that you have an abstract for a scientific paper: in the population synthesis simulations of pop iii stars , many bh ( black hole)-bh binaries with merger time less than the age of the universe @xmath0 are formed , while ns ( neutron star)-bh binaries are not . the reason is that pop iii stars have no metal so that no mass loss is expected . then , in the final supernova explosion to ns , much mass is lost so that the semi major axis becomes too large for pop iii ns - bh binaries to merge within @xmath1 . however it is almost established that the kick velocity of the order of @xmath2 exists for ns from the observation of the proper motion of the pulsar . therefore , the semi major axis of the half of ns - bh binaries can be smaller than that of the previous argument for pop iii ns - bh binaries to decrease the merging time . we perform population synthesis monte carlo simulations of pop iii ns - bh binaries including the kick of ns and find that the event rate of pop iii ns - bh merger rate is @xmath3 . this suggests that there is a good chance of the detection of pop iii ns - bh mergers in o2 of advanced ligo and advanced virgo from this autumn . . And you have already written the first three sentences of the full article: the proper - motion observations of pulsars show that the pulsars had the kick velocity in the formation stage . the young pulsars have proper velocity of @xmath4 @xcite . the physical mechanism of such kick velocity may be due to the harrison . Please generate the next two sentences of the article

tademaru mechanism @xcite , anisotropic emission of neutrinos , anisotropic explosion and so on ( see lorimer @xcite for the review ) . therefore , it is also reasonable to assume the existence of the proper motion of the pulsars in the formation process of pop iii nss , although there is no direct evidence since no pop iii star or pulsar is observed . while , repetto et al .

Suppose that you have an abstract for a scientific paper: we present far - ultraviolet photometry obtained with the _ hubble space telescope _ of the low - mass x - ray binary 4u 0513 - 40 in the globular cluster ngc 1851 . our observations reveal a clear , roughly sinusoidal periodic signal with @xmath0 min and amplitude 3%-10% . the signal appears fully coherent and can be modelled as a simple reprocessing effect associated with the changing projected area presented by the irradiated face of a white dwarf donor star in the system . all of these properties suggest that the signal we have detected is orbital in nature , thus confirming 4u 0513 - 40 as an ultracompact x - ray binary ( ucxb ) . all four confirmed ucxbs in globular clusters have orbital periods below 30 minutes , whereas almost all ucxbs in the galactic field have orbital periods longer than this . this suggests that the dynamical formation processes dominate ucxb production in clusters , producing a different orbital period distribution than observed among field ucxbs . based on the likely system parameters , we show that 4u 0513 - 40 should be a strong gravitational wave source and may be detectable by lisa over the course of a multi - year mission . . And you have already written the first three sentences of the full article: it has been known for several decades that bright low - mass x - ray binaries ( lmxbs ) are @xmath1 times overabundant in globular clusters ( gcs ) relative to the galactic field ( katz 1975 ; clark 1975 ) . more specifically , gcs contain 13 of the @xmath1 bright galactic lmxbs , but only @xmath20.01% of the total stellar mass content of the galaxy . the reason for this is thought to be the existence of _ dynamical _ lmxb formation channels , which are only available in dense gc cores .. Please generate the next two sentences of the article

potential channels include the direct collision of a neutron star ( ns ) with a red giants ( verbunt 1987 , davies et al . 1992 , ivanova et al .

Suppose that you have an abstract for a scientific paper: suppose that a lattice gas of constant density , described by the symmetric simple exclusion process , is brought in contact with a target " : a spherical absorber of radius @xmath0 . employing the macroscopic fluctuation theory ( mft ) , we evaluate the probability @xmath1 that no gas particle hits the target until a long but finite time @xmath2 . we also find the most likely gas density history conditional on the non - hitting . the results depend on the dimension of space @xmath3 and on the rescaled parameter @xmath4 , where @xmath5 is the gas diffusivity . for small @xmath6 and @xmath7 , @xmath1 is determined by an exact stationary solution of the mft equations that we find . for large @xmath6 , and for any @xmath6 in one dimension , the relevant mft solutions are non - stationary . in this case @xmath8 scales differently with relevant parameters , and it also depends on whether the initial condition is random or deterministic . the latter effects also occur if the lattice gas is composed of non - interacting random walkers . finally , we extend the formalism to a whole class of diffusive gases of interacting particles . . And you have already written the first three sentences of the full article: suppose that at @xmath9 a gas of diffusing particles of constant density @xmath10 is brought in contact with a spherical absorber of radius @xmath0 in @xmath3 dimensions . the particles are absorbed upon hitting the absorber . remarkably , this simple setting captures the essence of many diffusion - controlled chemical kinetic processes @xcite .. Please generate the next two sentences of the article

the evolution of the _ average _ coarse - grained particle density of the gas is described by the diffusion equation @xmath11 , \label{difeq}\ ] ] where @xmath12 is the gas diffusivity . here we will be interested in large fluctuations rather than in the average behavior .

Suppose that you have an abstract for a scientific paper: we describe a formalism to calculate form factor and charge density distribution of the pion in the chiral limit using the holographic dual model of qcd with hard - wall cutoff . we introduce two conjugate pion wave functions and present analytic expressions for these functions and for the pion form factor . they allow to relate such observables as the pion decay constant and the pion charge electric radius to the values of chiral condensate and hard - wall cutoff scale . the evolution of the pion form factor to large values of the momentum transfer is discussed , and results are compared to existing experimental data . . And you have already written the first three sentences of the full article: during the last few years applications of gauge / gravity duality @xcite to hadronic physics attracted a lot of attention , and various holographic dual models of qcd were proposed in the literature ( see , e.g. , @xcite ) . these models were able to incorporate such essential properties of qcd as confinement and chiral symmetry breaking , and also to reproduce many of the static hadronic observables ( decay constants , masses ) , with values rather close to the experimental ones . amongst the dual models , a special class is the so - called `` bottom - up '' approaches ( see , e.g. , @xcite ) , the goal of which is to reproduce known properties of qcd by choosing an appropriate theory in the 5-dimensional ( 5d ) ads bulk . within the framework of the ads / qcd models , by modifying the theory in the bulk one may try to explain / fit experimental results in different sectors of qcd . in the present paper. Please generate the next two sentences of the article

, we will be interested in the hard - wall ads / qcd model @xcite , where the confinement is modeled by sharp cutting off the ads space along the extra fifth dimension at a wall located at some finite distance @xmath0 . in the framework of this hard - wall model , it is possible to find form factors and wave functions of vector mesons ( see , e.g. , @xcite ) . to reproduce the general features of the spectrum for the higher states ( `` linear confinement '' ) ,

Suppose that you have an abstract for a scientific paper: we present high - resolution ultraviolet spectra of absorption - line systems toward the low@xmath0 qso 0624 ( @xmath1 ) . coupled with ground - based imaging and spectroscopic galaxy redshifts , we find evidence that many of these absorbers do not arise in galaxy halos but rather are truly integalactic gas clouds distributed within large - scale structures , and moreover , the gas is cool ( @xmath2 k ) and has relatively high metallicity ( @xmath3 ) . _ hst _ space telescope imaging spectrograph ( stis ) data reveal a dramatic cluster of 13 h@xmath4roman1 lines within a 1000 interval at @xmath5 . we find 10 galaxies at this redshift with impact parameters ranging from @xmath6 kpc to 1.37 @xmath7 mpc . the velocities and velocity spread of the lines in this complex are unlikely to arise in the individual halos of the nearby galaxies ; instead , we attribute the absorption to intragroup medium gas , possibly from a large - scale filament viewed along its long axis . contrary to theoretical expectations , this gas is not the shock - heated warm - hot intergalactic medium ( whim ) ; the width of the lines all indicate a gas temperature @xmath8 k , and metal lines detected in the complex also favor photoionised , cool gas . no o@xmath4roman6 absorption lines are evident , which is consistent with photoionisation models . remarkably , the metallicity is near - solar , [ m / h ] @xmath9 ( @xmath10 uncertainty ) , yet the nearest galaxy which might pollute the igm is at least 135 @xmath7 kpc away . tidal stripping from nearby galaxies appears to be the most likely origin of this highly enriched , cool gas . more than six abell galaxy clusters are found within @xmath11 of the sight line suggesting that the qso line of sight passes near a node in the cosmic web . at @xmath12 0.077 , we find absorption systems as well as galaxies at the redshift of the nearby clusters abell 564 and abell 559 . we conclude that the sight line pierces a filament of gas and galaxies feeding into these clusters.... And you have already written the first three sentences of the full article: in cold dark matter cosmology , the initially smooth distribution of matter in the universe is expected to collapse into a complex network of filaments and voids , structures which have been termed the `` cosmic web '' . the filamentary distribution of galaxies in the nearby universe has been revealed in detail by recent large galaxy redshift surveys such as the 2dfgrs ( colless et al . 2001 , baugh et al .. Please generate the next two sentences of the article

2004 ) , the sloan digital sky survey ( sdss , stoughton et al . 2002 , doroshkevich et al . 2004 ) and the 2@xmath19 all sky survey ( 2mass , maller et al .

Suppose that you have an abstract for a scientific paper: we present a new assessment of the ability of infrared dark clouds ( irdcs ) to form massive stars and clusters . this is done by comparison with an empirical mass - size threshold for massive star formation ( msf ) . we establish @xmath0 as a novel approximate msf limit , based on clouds with and without msf . many irdcs , if not most , fall short of this threshold . without significant evolution , such clouds are unlikely msf candidates . this provides a first quantitative assessment of the small number of irdcs evolving towards msf . irdcs below this limit might still form stars and clusters of up to intermediate mass , though ( like , e.g. , the ophiuchus and perseus molecular clouds ) . nevertheless , a major fraction of the mass contained in irdcs might reside in few @xmath1 clouds sustaining msf . . And you have already written the first three sentences of the full article: about a decade ago , galactic plane surveys revealed large numbers of infrared dark clouds ( irdcs , @xcite ; @xcite ) . these are identified as dark patches against the diffuse galactic mid - infrared background . first studies of very opaque irdcs suggested that these have very high densities , column densities , and masses ( @xmath2\gtrsim{}10 ^ 5~\rm{}cm^{-3}$ ] , @xmath3\gtrsim{}10^{23}~\rm{}cm^{-2}$ ] , @xmath4 ; @xcite ) . since they are dark , they are likely to be in an early evolutionary phase . embedded in irdcs are `` cores '' of a few dozen solar masses @xcite .. Please generate the next two sentences of the article

it has therefore been suggested that many irdcs are the long - sought examples of clouds just at the onset of the formation of massive stars and ( proto-)clusters . this notion was corroborated by observations of young massive stars in a few individual irdcs ( @xcite ; @xcite ; @xcite ) .

Suppose that you have an abstract for a scientific paper: the propagation of ultracold atomic gases through abruptly changing waveguide potentials is examined in the limit of non - interacting atoms . time - independent scattering calculations of microstructured waveguides with discontinuous changes in the transverse harmonic binding potentials are used to mimic waveguide perturbations and imperfections . three basic configurations are examined : step - like , barrier - like and well - like with waves incident in the ground mode . at low energies , the spectra rapidly depart from single - moded , with significant transmission and reflection of excited modes . the high - energy limit sees @xmath0 transmission , with the distribution of the transmitted modes determined simply by the overlap of the mode wave functions and interference . . And you have already written the first three sentences of the full article: the manipulation of ultracold matter waves can now , somewhat routinely , be performed above microchip or magnetized surfaces @xcite . in such experiments , the quantum nature of the dilute atomic gases dominates over the classical , enabling precision matter wave control @xcite . one of the key requirements in using an `` atom chip '' to perform atom optics is the ability to transport atoms from one atom optical component to another . here , we present calculations of wave propagation through waveguides with idealized perturbations consisting of sudden changes to the transverse confining potential .. Please generate the next two sentences of the article

an increase ( decrease ) in the tranverse confining potential results in a decrease ( increase ) in the kinetic energy along the direction of wave propagation , providing effective step potentials along the waveguide . the present study was motivated in three ways .

Suppose that you have an abstract for a scientific paper: models where dark matter and dark energy interact with each other have been proposed to solve the coincidence problem . we review the motivations underlying the need to introduce such interaction , its influence on the background dynamics and how it modifies the evolution of linear perturbations . we test models using the most recent observational data and we find that the interaction is compatible with the current astronomical and cosmological data . finally , we describe the forthcoming data sets from current and future facilities that are being constructed or designed that will allow a clearer understanding of the physics of the dark sector . . And you have already written the first three sentences of the full article: the first observational evidence that the universe had entered a period of accelerated expansion was obtained when supernovae type ia ( snia ) were found to be fainter than expected @xcite . this fact has been confirmed by many independent observations such as temperature anisotropies of the cosmic microwave background ( cmb ) @xcite , inhomogeneities in the matter distribution @xcite , the integrated sachs wolfe ( isw ) effect @xcite , baryon acoustic oscillations ( bao ) @xcite , weak lensing ( wl ) @xcite , and gamma - ray bursts @xcite . within the framework of general relativity ( gr ) , the accelerated expansion is driven by a new energy density component with negative pressure , termed dark energy ( de ) .. Please generate the next two sentences of the article

the nature of this unknown matter field has given rise to a great scientific effort in order to understand its properties . the observational evidence is consistent with a cosmological constant @xmath0 being the possible origin of the dark energy ( de ) driving the present epoch of the accelerated expansion of our universe and a dark matter ( dm ) component giving rise to galaxies and their large scale structures distributions @xcite .

Suppose that you have an abstract for a scientific paper: the convergence of the perturbation expansion for the effective interaction to be used in shell - model calculations is investigated as function of the mass number @xmath0 , from @xmath1 to @xmath2 . as the mass number increases , there are more intermediate states to sum over in each higher - order diagram which contributes to the effective interaction . together with the fact that the energy denominators in each diagram are smaller for larger mass numbers , these two effects could largely enhance higher - order contributions to the effective interaction , thereby deteriorating the order - by - order convergence of the effective interaction . this effect is counterbalanced by the short range of the nucleon - nucleon interaction , which implies that its matrix elements are weaker for valence single - particle states in `` large '' nuclei with large mass number as compared to those in light nuclei . these effects are examined by comparing various mean values of the matrix elements . it turns out that the contributions from higher - order terms remain fairly stable as the mass number increases from @xmath1 to @xmath2 . the implications for nuclear structure calculations are discussed . . And you have already written the first three sentences of the full article: one of the long - standing problems in nuclear many - body theory has been the convergence of the perturbative expansion for the effective interaction @xmath3 ( or equally well that of effective operators ) derived from realistic nuclear forces to be used in nuclear structure calculations . conventionally , the various terms which appear in a perturbative expansion for @xmath3 are displayed by way of feynman - goldstone diagrams , examples of such diagrams are shown in fig . [ fig : fig1 ] .. Please generate the next two sentences of the article

it is well known that a realistic nucleon - nucleon interaction @xmath4 contains strong components of short range , which renders a perturbative expansion in terms of @xmath4 meaningless . to overcome this problem , one takes into account the short - range correlations through the solution of the bethe - brueckner - goldstone equation and considers a perturbation in terms of the nuclear reaction matrix @xmath5 . the wavy lines in fig .

Suppose that you have an abstract for a scientific paper: recent discussion on the possibility to obtain more stringent bounds on neutrino magnetic moment has stimulated new interest to possible effects induced by neutrino magnetic moment . in particular , in this note after a short review on neutrino magnetic moment we re - examine the effect of plasmon mass on neutrino spin light radiation in dense matter . we track the entry of the plasmon mass quantity in process characteristics and found out that the most substantial role it plays is the formation of the process threshold . it is shown that far from this point the plasmon mass can be omitted in all the corresponding physical quantities and one can rely on the results of massless photon spin light radiation theory in matter . [ 1999/12/01 v1.4c il nuovo cimento ] . And you have already written the first three sentences of the full article: neutrino magnetic moments are no doubt among the most well theoretically understood and experimentally studied neutrino electromagnetic properties . @xcite as it was shown long ago @xcite , in a wide set of theoretical frameworks neutrino magnetic moment is proportional to the neutrino mass and in general very small . for instance , for the minimally extended standard model the dirac neutrino magnetic moment is given by @xcite : @xmath0 at the same time , the magnetic moment of hypothetical heavy neutrino ( with mass @xmath1 ) is @xmath2 @xcite .. Please generate the next two sentences of the article

it should be noted here that much larger values for the neutrino magnetic moments are possible in various extensions of the standard model ( see , for instance , in @xcite ) constraints on the neutrino magnetic moment can be obtained in @xmath3 scattering experiments from the observed lack of distortions of the recoil electron energy spectra . recent reactor experiments provides us with the following upper bounds on the neutrino magnetic moment : @xmath4 ( munu collaboration @xcite ) , @xmath5 ( texono collaboration @xcite ) .

Suppose that you have an abstract for a scientific paper: we formulate a general scheme to improve the truncated perturbative expansion in @xmath0 by means of the renormalization group in qcd for the single - scale quantities . the procedure is used for the evaluation of hadronic decay rates of @xmath1-lepton and @xmath2-charmonium . the scale dependence of result for @xmath2 is studied in the scheme of fixed value for the @xmath3-mass of charmed quark . = -1 cm = -2 cm . And you have already written the first three sentences of the full article: for many physical cases in qcd , an observable quantity is usually expressed in terms of truncated series in the coupling constant @xmath0 with given coefficients , so that in the next - to - next - to - next - to - leading order ( n@xmath4lo ) we get @xmath5 where @xmath6 are some numbers , and @xmath7 is a fixed scale . so , the value @xmath8 is the single - scale quantity . the exhausted examples are the followings : 1 . the hadronic fraction of @xmath1-decay width @xcite @xmath9 } { \gamma[\tau\to \nu_{\tau}e^+\nu_e ] } = \nonumber\\ & & { \cal r}_{\tau}^{[0 ] } \left ( 1 + c_1^{\tau}\,\frac{\alpha_s(m_{\tau})}{\pi}+ c_2^{\tau}\,\left(\frac{\alpha_s(m_{\tau})}{\pi}\right)^2 + c_3^{\tau}\,\left(\frac{\alpha_s(m_{\tau})}{\pi}\right)^3 + \delta r_{\mbox{\small np}}\right ) , \label{eq:2}\end{aligned}\ ] ] where @xmath10}=3.058 $ ] , the coefficients are given by @xmath11 and @xmath12 is a nonperturbative contribution .. Please generate the next two sentences of the article

the hadronic fraction of @xmath2-decay width @xcite @xmath13 } { \gamma[\eta_c\to \gamma\gamma ] } = { \cal r}_{\eta_c}^{[0 ] } \left ( 1 + d_1\,\frac{\alpha_s(2 m_c)}{\pi}\right),\end{aligned}\ ] ] where @xmath14 } = \frac{c_f}{2n_c}\,\frac{1}{e_c^4}\ , \frac{\alpha_s^2(2m_c)}{\alpha^2_{\rm em}}\ ] ] with @xmath15 , @xmath16 is the number of colors , @xmath17 is the electric charge of charmed quark , and the coefficient @xmath18 is given by @xmath19 where @xmath20 is the number of ` active ' flavors , and @xmath21 is the pole mass of charmed quark . the above formulae can be used for the extraction of @xmath0 at the appropriate scale .

Suppose that you have an abstract for a scientific paper: strong magnetic barriers are defined in two - dimensional electron gases by magnetizing dysprosium ferromagnetic platelets on top of a ga[al]as heterostructure . a small resistance across the barrier is observed even deep inside the closed regime . we have used semiclassical simulations to explain this behavior quantitatively in terms of a combined effect of elastic electron scattering inside the barrier region and e x b drift at the intersection of the magnetic barrier with the edge of the hall bar . . And you have already written the first three sentences of the full article: a two - dimensional electron gas ( 2deg ) reacts sensitively to perpendicular magnetic fields . making the magnetic field inhomogeneous opens the door to a wide variety of fascinating effects and applications , ranging from magnetic superlattices @xcite and magnetic waveguides @xcite to hall sensors for magnetic nanostructures . @xcite one particularly simple magnetic field structure is the _. Please generate the next two sentences of the article

magnetic barrier _ , namely a perpendicular magnetic field configuration strongly localized along one in - plane direction and homogeneous in the second one . @xcite in a classical picture , magnetic barriers can be considered as selective transmitters that filter the electrons according to their angle of incidence .

Suppose that you have an abstract for a scientific paper: we test the recent claim by hu et al . ( 2008 ) that feii emission in type 1 agn shows a systematic redshift relative to the local source rest frame and broad - line h@xmath0 . we compile high s / n median composites using sdss spectra from both the hu et al . sample and our own sample of the 469 brightest dr5 spectra . our composites are generated in bins of fwhm h@xmath0 and feii strength as defined in our 4d eigenvector 1 ( 4de1 ) formalism . we find no evidence for a systematic feii redshift and consistency with previous assumptions that feii shift and width ( fwhm ) follow h@xmath0 shift and fwhm in virtually all sources . this result is consistent with the hypothesis that feii emission ( quasi - ubiquitous in type 1 sources ) arises from a broad - line region with geometry and kinematics the same as that producing the balmer lines . . And you have already written the first three sentences of the full article: spectra of type 1 agn show a diversity of broad and narrow emission lines that provide direct insights into the structure and kinematics of photoionized , and otherwise excited , gas in the vicinity of the putative central massive object . broad emission lines , like much studied h@xmath0 ( e.g. , * ? ? ? * hereafter z10 ) , are thought to arise in or near an accretion disk acting as the fuel reservoir for the central supermassive black hole ( log m@xmath1 m@xmath2 ) .. Please generate the next two sentences of the article

h@xmath0 shows a diversity of line widths as well as profile shifts and asymmetries @xcite . despite this diversity some systematics have emerged and are best highlighted via the concept of two type 1 agn populations @xcite .

Suppose that you have an abstract for a scientific paper: we present an exact diagonalization study of the single particle spectral function in the 1d and 2d @xmath0@xmath1@xmath2 model . by studying the scaling properties with @xmath2 and @xmath0 we find a simple building pattern in 1d and show that every spectral feature can be uniquely assigned by a spinon and holon momentum . we find two types of low energy excitations : a band with energy scale @xmath2 and high spectral weight disperses upwards in the interior part of the brillouin zone and reaches @xmath3 at @xmath4 , and a band with energy scale @xmath0 and low spectral weight disperses downwards in the outer part of the zone , touching @xmath3 at @xmath5 . an analogous analysis of the 2d case at half filling shows that the @xmath0-band exists also in this case , but is diffuse and never reaches the fermi energy . for the doped case in 2d the picture is more reminiscent of 1d , in particular the ` main - band ' with a dispersion @xmath6 and the ` shadow band ' with energy scale @xmath0 can be identified also in this case . this leads us to propose that the shadow bands discovered by aebi _ et al . _ in bi2212 are the 2d analogue of the @xmath5 singularity in 1d systems and unrelated to antiferromagnetic spin fluctuations . 2 . And you have already written the first three sentences of the full article: recent developments in photoelectron spectroscopy have challenged the apparent simple truth that the fermi surface of cuprate superconductors is simply the one corresponding to lda band structures with the only effect of the closeness to the mott - hubbard insulator being a moderate correlation narrowing of the band width . the discovery of the ` shadow bands'@xcite , the temperature dependent pseudogap in the underdoped state@xcite and the substantial doping dependence of the quasiparticle band structure@xcite leave little doubt that a simple single - particle description is quite fundamentally inadequate for these materials . moreover , photoemission experiments on one - dimensional ( 1d ) copper oxides@xcite have shown very clear signatures of spin charge separation .. Please generate the next two sentences of the article

the equally clear nonobservation of these signatures in the cuprate superconductors at any doping level advises against another apparent simple truth , namely that the fermi surface seen in the cuprates is simply that of the ` spinons ' in a 2d version of the tomonaga - luttinger liquid ( tll ) realized in 1d . motivated by these developments , we have performed a detailed exact diagonalization study of the electron removal spectrum in the 1d and 2d @xmath0@xmath1@xmath2 model .

Suppose that you have an abstract for a scientific paper: we introduce and motivate the method of effective charges , and consider how to implement an all - orders resummation of large kinematical logarithms in this formalism . fits for qcd @xmath0 and power corrections are performed for the @xmath1 event shape obesrvables 1-thrust and heavy - jet mass , and somewhat smaller power corrections found than in the usual approach employing the `` physical scale '' choice . . And you have already written the first three sentences of the full article: in this talk i will describe some recent work together with michael dinsdale concerning the relative size of non - perturbative power corrections for qcd event shape observables @xcite . for @xmath1 event shape _ means _ the delphi collaboration have found in a recent analysis that , if the next - to - leading order ( nlo ) perturbative corrections are evaluated using the method of effective charges @xcite , then one can obtain excellent fits to data without includingany power corrections @xcite . in contrast fits based on the use of standard fixed - order perturbation theory in the @xmath2 scheme with a physical choice of renormalization scale equal to the c.m .. Please generate the next two sentences of the article

energy , require additional power corrections @xmath3 with @xmath4 . power corrections of this size are also predicted in a model based on an infrared finite coupling @xcite , which is able to fit the data reasonably well in terms of a single parameter .

Suppose that you have an abstract for a scientific paper: we reexamine the randall - sundrum ( rs ) model with enlarged gauge symmetry @xmath0 in the presence of a brane - localized higgs sector . in contrast to the existing literature , we perform the kaluza - klein ( kk ) decomposition within the mass basis , which avoids the truncation of the kk towers . expanding the low - energy spectrum as well as the gauge couplings in powers of the higgs vacuum expectation value , we obtain analytic formulas which allow for a deep understanding of the model - specific protection mechanisms of the @xmath1 parameter and the left - handed @xmath2-boson couplings . in particular , in the latter case we explain which contributions escape protection and identify them with the irreducible sources of @xmath3 symmetry breaking . we furthermore show explicitly that no protection mechanism is present in the charged - current sector confirming existing model - independent findings . the main focus of the phenomenological part of our work is a detailed discussion of higgs - boson couplings and their impact on physics at the cern large hadron collider . for the first time , a complete one - loop calculation of all relevant higgs - boson production and decay channels is presented , incorporating the effects stemming from the extended electroweak gauge - boson and fermion sectors . mz - th/10 - 18 + may 23 , 2010 + * the custodial randall - sundrum model : + from precision tests to higgs physics * s. casagrande@xmath4 , f. goertz@xmath5 , u. haisch@xmath5 , m. neubert@xmath6 and t. pfoh@xmath5 + . And you have already written the first three sentences of the full article: precision experiments in the last two decades have elevated the standard model ( sm ) of particle physics from a promising description to a provisional law of nature , tested as a quantum field theory at the level of one percent or better . despite its triumphs the sm is not an entirely satisfactory theory , however , because it has various theoretical shortcomings . in particular , the gauge hierarchy problem , _ i.e. _ , the instability of the electroweak scale @xmath7 under radiative corrections , has spurred the imagination of many theorists and led to the development of a plethora of models of physics beyond the sm that envision new phenomena at or not far above the tev scale . a particularly appealing proposal for stabilizing the electroweak scale , featuring one compact extra dimension with a non - factorizable anti - de sitter ( ads@xmath8 ) metric , is the randall - sundrum ( rs ) model @xcite , which by virtue of the ads / cft correspondence @xcite can be thought of as dual to a strongly coupled four - dimensional ( 4d ) cft . with two three - branes acting as the boundaries of the warped extra dimension. Please generate the next two sentences of the article

, the ads@xmath8 background generates an exponential hierarchy of energy scales , so that the natural scale at one orbifold fixed point ( the ultra - violet ( uv ) brane ) is much larger than at the other ( the infra - red ( ir ) brane ) , @xmath9 . in the rs framework the gauge hierarchy problem is thus solved by gravitational red - shifting .

Suppose that you have an abstract for a scientific paper: from social networks to p2p systems , network sampling arises in many settings . we present a detailed study on the nature of biases in network sampling strategies to shed light on how best to sample from networks . we investigate connections between specific biases and various measures of structural representativeness . we show that certain biases are , in fact , beneficial for many applications , as they `` push '' the sampling process towards inclusion of desired properties . finally , we describe how these sampling biases can be exploited in several , real - world applications including disease outbreak detection and market research . [ data mining ] . And you have already written the first three sentences of the full article: we present a detailed study on the nature of biases in network sampling strategies to shed light on how best to sample from networks . a _ network _ is a system of interconnected entities typically represented mathematically as a graph : a set of vertices and a set of edges among the vertices . networks are ubiquitous and arise across numerous and diverse domains . for instance , many web - based social media , such as online social networks , produce large amounts of data on interactions and associations among individuals .. Please generate the next two sentences of the article

mobile phones and location - aware devices produce copious amounts of data on both communication patterns and physical proximity between people . in the domain of biology also , from neurons to proteins to food webs , there is now access to large networks of associations among various entities and a need to analyze and understand these data . with advances in technology , pervasive use of the internet , and the proliferation of mobile phones and location - aware devices , networks under study today are not only substantially larger than those in the past , but sometimes exist in a decentralized form ( e.g. the network of blogs or the web itself ) . for many networks ,

Suppose that you have an abstract for a scientific paper: we discuss the production of real or virtual photons in a quark - gluon plasma . laboratoire de physique thorique lapth , + bp110 , f-74941 , annecy le vieux cedex , france lapth - conf-810/2000 . And you have already written the first three sentences of the full article: it has long been thought that electro - magnetic probes _ i.e. _ real or virtual photons would provide a way to detect the formation of a quark - gluon plasma in ultra - relativistic heavy ion collisions . the energy distribution of the photons would allow to measure the temperature of the plasma provided the rate of production in the plasma exceeds that of various backgrounds .. Please generate the next two sentences of the article

it is expected that this will occur in a small window in the gev range for the energy of the photon . at lower values of the energy the rate is dominated by various hadron decay processes while at higher values the usual hard processes ( those occurring in the very early stage of the collision before the plasma is formed ) , calculable by standard perturbative qcd methods , would dominate . in contrast to hadronic observables ( or heavy quarkonia ) which are sensitive to the late evolution of the plasma as well as to the re - hadronisation phase , the photons in the gev range are produced soon after the plasma is formed and then they escape the plasma without further interaction .

Suppose that you have an abstract for a scientific paper: we describe the fundamental constructions and properties of determinantal probability measures and point processes , giving streamlined proofs . we illustrate these with some important examples . we pose several general questions and conjectures . primary 60k99 , 60g55 ; secondary 42c30 , 37a15 , 37a35 , 37a50 , 68u99 . random matrices , eigenvalues , orthogonal projections , positive contractions , exterior algebra , stochastic domination , negative association , point processes , mixtures , spanning trees , orthogonal polynomials , completeness , bernoulli processes . determinantal point processes were originally defined by macchi @xcite in physics . starting in the 1990s , determinantal probability began to flourish as examples appeared in numerous parts of mathematics @xcite . recently , applications to machine learning have appeared @xcite . a discrete determinantal probability measure is one whose elementary cylinder probabilities are given by determinants . more specifically , suppose that @xmath0 is a finite or countable set and that @xmath1 is an @xmath2 matrix . for a subset @xmath3 , let @xmath4 denote the submatrix of @xmath1 whose rows and columns are indexed by @xmath5 . if @xmath6 is a random subset of @xmath0 with the property that for all finite @xmath7 , we have e.dpm = ( qa ) , then we call @xmath8 a . the inclusion - exclusion principle in combination with yields the probability of each elementary cylinder event . therefore , for every @xmath1 , there is at most one probability measure , to be denoted @xmath9 , on subsets of @xmath0 that satisfies . conversely , it is known ( see , e.g. , b.lyons:det/ ) that there is a determinantal probability measure corresponding to @xmath1 if @xmath1 is the matrix of a positive contraction on @xmath10 ( in the standard orthonormal basis ) . technicalities are required even to define the corresponding concept of determinantal point process for @xmath0 being euclidean space or a more general space . we present.... And you have already written the first three sentences of the full article: i am grateful to alekos kechris for informing me of t.dyck/ ; the proof given seems to be due to alain louveau . i thank norm levenberg for references . hough , j.b .. Please generate the next two sentences of the article

, krishnapur , m. , peres , y. , and virg , b. , _ zeros of gaussian analytic functions and determinantal point processes_. university lecture series , * 51*. american mathematical society , providence , ri , 2009 . mester , p. , invariant monotone coupling need not exist .

Suppose that you have an abstract for a scientific paper: recently , a multi - level fuzzy min max neural network ( mlf ) was proposed , which improves the classification accuracy by handling an overlapped region ( area of confusion ) with the help of a tree structure . in this brief , an extension of mlf is proposed which defines a new boundary region , where the previously proposed methods mark decisions with less confidence and hence misclassification is more frequent . a methodology to classify patterns more accurately is presented . our work enhances the testing procedure by means of data centroids . we exhibit an illustrative example , clearly highlighting the advantage of our approach . results on standard datasets are also presented to evidentially prove a consistent improvement in the classification rate . hyperbox , fuzzy min - max , data centroids , neural networks , neurofuzzy , classification , machine learning . . And you have already written the first three sentences of the full article: set theory was proposed with the intended use to the fields of pattern classification and information processing [ 1 ] . indeed , it has attracted many researchers , and their applications to real - life problems are of a great significance . simpson [ 2 ] presented the fuzzy min max neural network ( fmm ) , which makes the soft decisions to organize hyperboxes by its degree of belongingness to a particular class , which is known as a membership function .. Please generate the next two sentences of the article

hyperbox is a convex box , completely represented by min and max points . fmm classification results are completely characterized with the help of a membership function .

Suppose that you have an abstract for a scientific paper: we define the anti - forcing number of a perfect matching @xmath0 of a graph @xmath1 as the minimal number of edges of @xmath1 whose deletion results in a subgraph with a unique perfect matching @xmath0 , denoted by @xmath2 . the anti - forcing number of a graph proposed by vukievi and trinajsti in kekul structures of molecular graphs is in fact the minimum anti - forcing number of perfect matchings . for plane bipartite graph @xmath1 with a perfect matching @xmath0 , we obtain a minimax result : @xmath2 equals the maximal number of @xmath0-alternating cycles of @xmath1 where any two either are disjoint or intersect only at edges in @xmath0 . for a hexagonal system @xmath3 , we show that the maximum anti - forcing number of @xmath3 equals the fries number of @xmath3 . as a consequence , we have that the fries number of @xmath3 is between the clar number of @xmath3 and twice . further , some extremal graphs are discussed . * keywords : * graph ; hexagonal system ; perfect matching ; forcing number ; anti - forcing number ; fries number . . And you have already written the first three sentences of the full article: we only consider finite and simple graphs . let @xmath1 be a graph with vertex set @xmath4 and edge set @xmath5 . a perfect matching or 1-factor @xmath0 of a graph @xmath1 is a set of edges of @xmath1 such that each vertex of @xmath1 is incident with exactly one edge in @xmath0 . a kekul structure of some molecular graph ( for example , benzenoid and fullerene ) coincides with a perfect matching of a graph .. Please generate the next two sentences of the article

randi and klein @xcite proposed the _ innate degree of freedom _ of a kekul structure , i.e. the least number of double bonds can determine this entire kekule structure , nowadays it is called the forcing number by harary et al . @xcite . a _ forcing set _ @xmath6 of a perfect matching @xmath0 of @xmath1 is a subset of @xmath0 such that @xmath6 is contained in no other perfect matchings of @xmath1 .

Suppose that you have an abstract for a scientific paper: we analyse star formation in the nuclei of 9 seyfert galaxies at spatial resolutions down to 0.085 , corresponding to length scales of order 10pc in most objects . our data were taken mostly with the near infrared adaptive optics integral field spectrograph sinfoni . the stellar light profiles typically have size scales of a few tens of parsecs . in two cases there is unambiguous kinematic evidence for stellar disks on these scales . in the nuclear regions there appear to have been recent but no longer active starbursts in the last 10 - 300myr . the stellar luminosity is less than a few percent of the agn in the central 10pc , whereas on kiloparsec scales the luminosities are comparable . the surface stellar luminosity density follows a similar trend in all the objects , increasing steadily at smaller radii up to @xmath0l@xmath1kpc@xmath2 in the central few parsecs , where the mass surface density exceeds 10@xmath3m@xmath1pc@xmath2 . the intense starbursts were probably eddington limited and hence inevitably short - lived , implying that the starbursts occur in multiple short bursts . the data hint at a delay of 50100myr between the onset of star formation and subsequent fuelling of the black hole . we discuss whether this may be a consequence of the role that stellar ejecta could play in fuelling the black hole . while a significant mass is ejected by ob winds and supernovae , their high velocity means that very little of it can be accreted . on the other hand winds from agb stars ultimately dominate the total mass loss , and they can also be accreted very efficiently because of their slow speeds . . And you have already written the first three sentences of the full article: during recent years there has been increasing evidence for a connection between active galactic nuclei ( agn ) and star formation in the vicinity of the central black holes . this subject forms the central topic of this paper , and is discussed in sections [ sec : prop ] and [ sec : staragn ] . a large number of studies have addressed the issue of star formation around agn .. Please generate the next two sentences of the article

those which have probed closest to the nucleus , typically on scales of a few hundred parsecs , have tended to focus on seyferts notably seyfert2 galaxies since these are the closest examples @xcite . the overall conclusion of these studies is that in 3050% cases the agn is associated with young ( i.e. age less than a few 100myr ) star formation .

Suppose that you have an abstract for a scientific paper: we have developed a new , very efficient numerical scheme to solve the cr diffusion convection equation that can be applied to the study of the nonlinear time evolution of cr modified shocks for arbitrary spatial diffusion properties . the efficiency of the scheme derives from its use of coarse - grained finite momentum volumes . this approach has enabled us , using @xmath0 momentum bins spanning nine orders of magnitude in momentum , to carry out simulations that agree well with results from simulations of modified shocks carried out with our conventional finite difference scheme requiring more than an order of magnitude more momentum points . the coarse - grained , cgmv scheme reduces execution times by a factor approximately half the ratio of momentum bins used in the two methods . depending on the momentum dependence of the diffusion , additional economies in required spatial and time resolution can be utilized in the cgmv scheme , as well . these allow a computational speed - up of at least an order of magnitude in some cases . , . And you have already written the first three sentences of the full article: collisionless shocks are widely thought to be effective accelerators of energetic , nonthermal particles ( hereafter cosmic - rays or crs ) . those particles play central roles in many astrophysical problems . the physical basis of the responsible diffusive shock acceleration ( dsa ) process is now well established through in - situ measurements of heliospheric shocks @xcite and through analytic and numerical calculations @xcite . while test particle dsa model treatments are relatively well developed ; e.g. , @xcite , it has long been recognized that dsa is an integral part of collisionless shock physics and that there are substantial and highly nonlinear backreactions from the crs to the bulk flows and to the mhd wave turbulence mediating the cr diffusive transport ( see , for example , @xcite and references therein ) .. Please generate the next two sentences of the article

most critically , the crs can capture a large fraction of the kinetic energy dissipated across such transitions . as they diffuse upstream the crs form a pressure gradient that decelerates and compresses the entering flow inside a broad shock precursor .

Suppose that you have an abstract for a scientific paper: we have presented dynamic phase transition features and stationary - state behavior of a ferrimagnetic small nanoparticle system with a core - shell structure . by means of detailed monte carlo simulations , a complete picture of the phase diagrams and magnetization profiles have been presented and the conditions for the occurrence of a compensation point @xmath0 in the system have been investigated . according to nel nomenclature , the magnetization curves of the particle have been found to obey p - type , n - type and q - type classification schemes under certain conditions . much effort has been devoted to investigation of hysteretic response of the particle and we observed the existence of triple hysteresis loop behavior which originates from the existence of a weak ferromagnetic core coupling @xmath1 , as well as a strong antiferromagnetic interface exchange interaction @xmath2 . most of the calculations have been performed for a particle in the presence of oscillating fields of very high frequencies and high amplitudes in comparison with exchange interactions which resembles a magnetic system under the influence of ultrafast switching fields . particular attention has also been paid on the influence of the particle size on the thermal and magnetic properties , as well as magnetic features such as coercivity , remanence and compensation temperature of the particle . we have found that in the presence of ultrafast switching fields , the particle may exhibit a dynamic phase transition from paramagnetic to a dynamically ordered phase with increasing ferromagnetic shell thickness . . And you have already written the first three sentences of the full article: in recent years , influences of small - size and surface effects on the magnetic properties of magnetic nanoparticles have provided a conspicuous and productive field for the interaction between theoretical works @xcite and technological @xcite , as well as biomedical applications @xcite . as the physical size of a magnetic system reduces to a characteristic length , surface effects become dominant on the system , hence , some unusual and interesting magnetic phenomena can be observed , which may differ from those of bulk materials @xcite . recent developments in the experimental techniques allow the scientists to fabricate such kinds of fine nanoscaled materials @xcite , and the magnetization of certain nanomaterials such as @xmath3-@xmath4 nanoparticles has been experimentally measured @xcite .. Please generate the next two sentences of the article

in particular , magnetic nanowires and nanotubes such as @xmath5 @xcite , @xmath6 and @xmath7 @xcite can be synthesized by various experimental techniques and they have many applications in nanotechnology @xcite . from the theoretical point of view , many studies have been performed regarding the magnetic properties of nanoparticles , such as nanowire , nanotube , and nanorod systems , and theoretical works can be classified in two basic categories based on the investigation of equilibrium or nonequilibrium phase transition properties of such nanoscaled magnetic structures . namely , in the former group , equilibrium properties of these systems have been investigated by a variety of techniques such as mean field theory ( mft ) @xcite , effective - field theory ( eft ) @xcite , green functions formalism @xcite , variational cumulant expansion ( vce ) @xcite and monte carlo ( mc ) simulations @xcite . based on mc simulations ,

Suppose that you have an abstract for a scientific paper: we have used high - resolution , hst wfc3/ir , near - infrared imaging to conduct a detailed bulge - disk decomposition of the morphologies of @xmath0 of the most massive ( @xmath1 ) galaxies at @xmath2 in the candels - uds field . we find that , while such massive galaxies at low redshift are generally bulge - dominated , at redshifts @xmath3 they are predominantly mixed bulge+disk systems , and by @xmath4 they are mostly disk - dominated . interestingly , we find that while most of the quiescent galaxies are bulge - dominated , a significant fraction ( @xmath5% ) of the most quiescent galaxies , have disk - dominated morphologies . thus , our results suggest that the physical mechanisms which quench star - formation activity are not simply connected to those responsible for the morphological transformation of massive galaxies . . And you have already written the first three sentences of the full article: the study of the high - redshift progenitors of today s massive galaxies can provide us with invaluable insights into the key mechanisms that shape the evolution of galaxies in the high - mass regime . the latest generation of galaxy formation models are now able to explain the number densities and ages of massive galaxies at high redshift . however , this is only part of the challenge , as recent studies have posed new questions about how the morphologies of massive galaxies evolve with redshift . in addition to the basic question of how high - redshift galaxies evolve in size , there is also still much debate about how these massive galaxies evolve in terms of their fundamental morphological type .. Please generate the next two sentences of the article

extensive studies of the local universe have revealed a bimodality in the colour - morphology plane , with spheroidal galaxies typically inhabiting the red sequence and disk galaxies making up the blue cloud ( e.g. ( * ? ? ? * baldry et al . 2004 ) ) .

Suppose that you have an abstract for a scientific paper: this paper considers @xmath0-graphs in which all vertices have degree 4 or 6 , and studies the question of calculating the genus of nonorientable surfaces into which such graphs may be embedded . in a previous paper @xcite by the authors , the problem of calculating whether a given @xmath0-graph in which all vertices have degree 4 or 6 admits a @xmath1-homologically trivial embedding into a given orientable surface was shown to be equivalent to a problem on matrices . here we extend those results to nonorientable surfaces . the embeddability condition that we obtain yields quadratic - time algorithms to determine whether a @xmath0-graph with all vertices of degree 4 or 6 admits a @xmath1-homologically trivial embedding into the projective plane or into the klein bottle . * keywords : * graph , @xmath0-graph , surface , embedding , genus * ams subject classification : * primary 05c10 ; secondary 57c15 , 57c27 . And you have already written the first three sentences of the full article: a _ @xmath0-graph _ is a graph which at each vertex has a bijection from the outgoing half - edges to the vertices of a cycle graph . half - edges which are mapped to adjacent vertices are ( formally ) _ adjacent_. half - edges are said to be _ opposite _ if they are mapped to vertices of maximal distance in the cycle graph . by an embedding of a @xmath0-graph @xmath2 into a surface @xmath3. Please generate the next two sentences of the article

we always mean an embedding of @xmath2 into @xmath3 such that the formal relation of being adjacent coincides with the relation of being adjacent induced by the embedding . an _ angle _ in a @xmath0-graph is a pair of adjacent half - edges at a vertex .

Suppose that you have an abstract for a scientific paper: a coordinated cyber - attack on grid meter readings and breaker statuses can lead to incorrect state estimation that can subsequently destabilize the grid . this paper studies cyber - attacks by an adversary that changes breaker statuses on transmission lines to affect the estimation of the grid topology . the adversary , however , is incapable of changing the value of any meter data and can only block recorded measurements on certain lines from being transmitted to the control center . the proposed framework , with limited resource requirements as compared to standard data attacks , thus extends the scope of cyber - attacks to grids secure from meter corruption . we discuss necessary and sufficient conditions for feasible attacks using a novel graph - coloring based analysis and show that an optimal attack requires breaker status change at only one transmission line . the potency of our attack regime is demonstrated through simulations on ieee test cases . . And you have already written the first three sentences of the full article: real time operation of the power grid and computation of electricity prices @xcite require accurate estimation of its structure and critical state variables . remote terminal units ( rtus ) transmit measurements collected from different grid components to the central control center for state estimation and subsequent use in analyzing grid stability . the collected measurements can be broadly classified into two kinds : meter readings and breaker statuses .. Please generate the next two sentences of the article

the breaker statuses on transmission lines help create the current operational topology of the grid . the meter readings , comprising of line flow and bus power injection measurements , are then used to estimate the state variables over the estimated topology . in a practical

Suppose that you have an abstract for a scientific paper: given an n - dimensional natural hamiltonian l on a riemannian or pseudo - riemannian manifold , we call `` extension '' of l the n+1 dimensional hamiltonian @xmath0 with new canonically conjugated coordinates @xmath1 . for suitable l , the functions @xmath2 and @xmath3 can be chosen depending on any natural number m such that h admits an extra polynomial first integral in the momenta of degree m , explicitly determined in the form of the m - th power of a differential operator applied to a certain function of coordinates and momenta . in particular , if l is maximally superintegrable ( ms ) then h is ms also . therefore , the extension procedure allows the creation of new superintegrable systems from old ones . for m=2 , the extra first integral generated by the extension procedure determines a second - order symmetry operator of a laplace - beltrami quantization of h , modified by taking in account the curvature of the configuration manifold . the extension procedure can be applied to several hamiltonian systems , including the three - body calogero and wolfes systems ( without harmonic term ) , the tremblay - turbiner - winternitz system and n - dimensional anisotropic harmonic oscillators . we propose here a short review of the known results of the theory and some previews of new ones . . And you have already written the first three sentences of the full article: natural hamiltonian systems are the mathematical models of those physical systems for which the energy is constant , for example harmonic oscillators or the kepler system . often , as in the previous two examples , more quantities are constants of the motion ( or _ first integrals _ ) : angular momentum , laplace - runge - lentz vector , etc . usually , these constants are expressed by quadratic polynomials in the momenta or , for quantum systems , by second - order differential operators . hamiltonian systems with constants of the motion of degree higher than two are less common , nevertheless , some of them are of great interest , as for instance the three - body jacobi - calogero and wolfes systems .. Please generate the next two sentences of the article

these systems represent the dynamics of three point - masses on a line under forces determined by the potential functions @xmath4 respectively ( we do not consider here the harmonic oscillator terms ) and they have essentially the same dynamics @xcite . both the resulting natural hamiltonians in @xmath5 admit one linear and one quadratic in the momenta constants of the motion , making the systems liouville - integrable and solvable by separation of variables ( see @xcite and references therein ) . other two independent constants of the motion do exist , one quadratic , due to the multiseparability of the hamiltonian , and one cubic .

Suppose that you have an abstract for a scientific paper: dense cores are the simplest star - forming sites that we know , but despite their simplicity , they still hold a number of mysteries that limit our understanding of how solar - type stars form . alma promises to revolutionize our knowledge of every stage in the life of a core , from the pre - stellar phase to the final disruption by the newly born star . this contribution presents a brief review of the evolution of dense cores and illustrates particular questions that will greatly benefit from the increase in resolution and sensitivity expected from alma . . And you have already written the first three sentences of the full article: nearby dark clouds like taurus and perseus contain dozens of dense molecular cores where stars like our sun are currently forming or have done so in the recent past ( myers 1995 ) . their large number , together with their proximity and simple structure , make cores unique targets to study the complex physics involved in the formation of a star . dense cores that have not yet formed stars , the so called starless or pre - stellar cores , inform us of the initial conditions of star formation , and their study can help us elucidate the process by which pockets of cloud material condense and become gravitationally unstable. Please generate the next two sentences of the article

. cores with deeply embedded young stellar objects ( `` protostellar cores '' ) are unique targets to study the complex motions that occur during the period of accretion , when a combination of infall , outflow , and rotation is necessary to assemble the star and redistribute the gas angular momentum . finally , evolved cores are primary targets to study the interaction between the newly born star and its environment . these feedback effects are responsible for the transition of the protostar from embedded to visible , and may be important determining the final mass of the star and stabilizing the nearby gas via turbulence generation . the observational study of dense cores has advanced enormously over the last decade thanks to the increase in resolution provided by the new millimeter and submillimeter interferometers , and also due to the systematic combination of observations of dust and molecular tracers ( e.g. , bergin & tafalla 2007 ) .

Suppose that you have an abstract for a scientific paper: we have examined the relation for early - type galaxies in the efar sample and its dependence on cluster properties . a comprehensive maximum likelihood treatment of the sample selection and measurement errors gives fits to the global relation of @xmath0 and @xmath1 . the slope of these relations is 25% steeper than that obtained by most other authors due to the reduced bias of our fitting method . the intrinsic scatter in the global relation is estimated to be 0.016 mag in and 0.023 mag in . the relation for cd galaxies has a higher zeropoint than for e and s0 galaxies , implying that cds are older and/or more metal - rich than other early - type galaxies with the same velocity dispersion . we investigate the variation in the zeropoint of the relation between clusters . we find it is consistent with the number of galaxies observed per cluster and the intrinsic scatter between galaxies in the global relation . we find no significant correlation between the zeropoint and the cluster velocity dispersion , x - ray luminosity or x - ray temperature over a wide range in cluster mass . these results provide constraints for models of the formation of elliptical galaxies . however the relation on its own does not place strong limits on systematic errors in fundamental plane distance estimates due to stellar population differences between clusters . we compare the intrinsic scatter in the and fundamental plane ( fp ) relations with stellar population models in order to constrain the dispersion in ages , metallicities and @xmath2 ratios for early - type galaxies at fixed velocity dispersion . we find that variations in age alone or metallicity alone can not explain the measured intrinsic scatter in both and the fp . we derive the joint constraints on the dispersion in age and metallicity implied by the scatter in the and fp relations for a simple gaussian model . we find upper limits on the dispersions in age and metallicity at fixed velocity dispersion of 32% in @xmath3.... And you have already written the first three sentences of the full article: the primary aim of the efar project ( wegner 1996 ; paper 1 ) is to use the tight correlations between the global properties of early - type galaxies embodied in the fundamental plane ( fp : djorgovski & davis 1987 , dressler 1987 ) to measure relative distances to clusters of galaxies in order to investigate peculiar motions and the mass distribution on large scales . however these global relations also constrain the dynamical properties and evolutionary histories of early - type galaxies . for example , renzini & ciotti ( 1993 ) show that the tilt of the fp implies a range in mass - to - light ratio @xmath2 among ellipticals of less than a factor of three , while the low scatter about the fp implies a scatter in @xmath2 at any location in the plane of less than 12% .. Please generate the next two sentences of the article

similar reasoning has been used to constrain the star formation history of cluster ellipticals using the colour magnitude relation ( bower 1992 , kodama & arimoto 1997 ) . recently the fp , and colour magnitude relations have been followed out to higher redshifts and used to show that the early - type galaxies seen at @xmath9@xmath101 differ from present - day early - type galaxies in a manner consistent with passive evolutionary effects ( van dokkum & franx 1996 , ziegler & bender 1997 , kelson 1997 , ellis 1997 , kodama & arimoto 1997 , stanford 1998 , kodama 1998 , bender 1998 , van dokkum 1998 ) . in this paper

Suppose that you have an abstract for a scientific paper: the microcanonical multifragmentation model from [ al . h. raduta and ad . r. raduta , phys . rev . c * 55 * , 1344 ( 1997 ) ; * 56 * , 2059 ( 1997 ) ; * 59 * , 323 ( 1999 ) ] is refined and improved by taking into account the experimental discrete levels for fragments with @xmath0 and by including the stage of sequential decay of the primary excited fragments . the caloric curve is reevaluated and the heat capacity at constant volume curve is represented as a function of excitation energy and temperature . the sequence of equilibrated sources formed in the reactions studied by the aladin group ( @xmath1au+@xmath1au at 600 , 800 and 1000 mev / nucleon bombarding energy ) is deduced by fitting simultaneously the model predicted mean multiplicity of intermediate mass fragments ( @xmath2 ) and charge asymmetry of the two largest fragments ( @xmath3 ) versus bound charge ( @xmath4 ) on the corresponding experimental data . calculated heli isotopic temperature curves as a function of the bound charge are compared with the experimentally deduced ones . . And you have already written the first three sentences of the full article: nuclear multifragmentation is presently intensely studied both theoretically and experimentally . due to the similitude existent between the nucleon - nucleon interaction and the van der waals forces , signs of a liquid - gas phase transition in nuclear matter are searched . while the theoretical calculations concerning this problem started at the beginning of 1980 @xcite , the first experimental evaluation of the nuclear caloric curve was reported in 1995 by the aladin group @xcite . a wide plateau situated at around 5 mev temperature lasting from 3 to 10 mev / nucleon excitation energy was identified .. Please generate the next two sentences of the article

the fact was obviously associated with the possible existence of a liquid - gas phase transition in nuclear matter and generated new motivations for further theoretical and experimental work . similar experiments of eos @xcite and indra @xcite followed shortly . using different reactions they obtained slightly different caloric curves , the plateau - like region being absent in the majority of cases .

Suppose that you have an abstract for a scientific paper: the ladder theory , in which the bethe - goldstone equation for the effective potential between two scattering particles plays a central role , is well known for its satisfactory description of the short - range correlations in the homogeneous electron liquid . by solving exactly the bethe - goldstone equation in the limit of large transfer momentum between two scattering particles , we obtain accurate results for the on - top pair - correlation density @xmath0 , in both three dimensions and two dimensions . furthermore , we prove , in general , the ladder theory satisfies the cusp condition for the pair - correlation density @xmath1 at zero distance @xmath2 . . And you have already written the first three sentences of the full article: the pair - correlation density @xmath1 is one of the key concepts in describing the correlation effects , arising from pauli exclusion principle and coulomb interaction , in the homogeneous electron liquid ( or gas).@xcite it also plays a significant role in the constructions of the exchange - correlation energy density functionals in density - functional theory ( dft),@xcite since in such constructions the homogeneous electron system is conventionally taken as a reference system . a great deal of theoretical progress has recently been made in giving an accurate evaluation of @xmath1 , or the more specific spin - resolved pair - correlation densities @xmath3 , with @xmath4$].@xcite in particular , @xmath0 , the on - top pair - correlation density , which arises totally from @xmath5 since @xmath6 , has been well known to play a special role in dft.@xcite the important implication of @xmath0 was also realized in many - body theory long ago because the random phase approximation ( rpa),@xcite due to its lack of accurate description of the short - range electron correlations , yields erroneous negative values for @xmath0 when the electron densities are not sufficiently high.@xcite it is well known that , in many - body theory , the long - range correlations can be rather successfully taken into account in the rpa , while the short - range correlations can be properly described by the ladder theory ( lt).@xcite in this paper , we attempt to investigate the short - range correlations in terms of @xmath7 in the lt , in both three dimensions ( 3d ) and two dimensions ( 2d ) . in fact , investigations in this direction date back long ago , and a great deal of achievement has been made .. Please generate the next two sentences of the article

@xcite it is necessary here to give some introduction to the lt . the effective interaction @xmath8 in the lt between two scattering electrons with respective momenta @xmath9 and @xmath10 satisfies the following bethe - goldstone equation:@xcite @xmath11 where @xmath12 is the fourier transform of the coulomb potential , @xmath13 is the momentum distribution in the noninteracting ground state and @xmath14 is the fermi momentum , and @xmath15 . as mentioned above

Suppose that you have an abstract for a scientific paper: it is well known that the late - time behaviour of gravitational collapse is _ dominated _ by an inverse power - law decaying tail . we calculate _ higher - order corrections _ to this power - law behaviour in a spherically symmetric gravitational collapse . the dominant `` contamination '' is shown to die off at late times as @xmath0 . this decay rate is much _ slower _ than has been considered so far . it implies , for instance , that an ` exact ' ( numerical ) determination of the power index to within @xmath1 requires extremely long integration times of order @xmath2 . we show that the leading order fingerprint of the black - hole electric _ charge _ is of order @xmath3 . . And you have already written the first three sentences of the full article: waves propagating in a curved spacetime develop `` tails '' . in particular , it is well established that the _ dominant _ late - time behaviour of massless fields propagating in black - hole spacetimes is a power - law tail . price @xcite was the first to analyze the mechanism by which the spacetime outside a ( nearly spherical ) collapsing star divests itself of all radiative multipole moments , and leaves behind a schwarzschild black hole ; it was demonstrated that all radiative perturbations decay asymptotically as an inverse power of time . physically , these inverse power - law tails are associated with the backscattering of waves off the effective curvature potential at asymptotically far regions @xcite .. Please generate the next two sentences of the article

the analysis of price was extended by other authors . bik @xcite generalized the analysis and studied the dynamics of a scalar field in a _ charged _ reissner - nordstrm spacetime .

Suppose that you have an abstract for a scientific paper: we present a theoretical study on the orbital magnetism in multilayer graphenes within the effective mass approximation . the hamiltonian and thus susceptibility can be decomposed into contributions from sub - systems equivalent to monolayer or bilayer graphene . the monolayer - type subband exists only in odd layers and exhibits a delta - function susceptibility at @xmath0 . the bilayer - type subband appearing in every layer number gives a singular structure in the vicinity of @xmath0 due to the trigonal warping as well as a logarithmic tail away from @xmath0 . the integral of the susceptibility over energy is approximately given only by the layer number . . And you have already written the first three sentences of the full article: recently unconventional electronic properties of mono - crystalline graphenes attracts much attention motivated by experimental fabrication,@xcite although they were already the subject of theoretically study prior to the fabrication.@xcite multilayer films which contain more than two layers can also be synthesized , and various phenomena depending on the layer number have been reported.@xcite in this paper we present a theoretical study on the orbital magnetism in multilayer graphenes . the electronic structure of the monolayer graphene is quite different from conventional metals , because the conduction and valence bands touch at @xmath1 and @xmath2 points in the brillouin zone , around which the dispersion becomes linear like a relativistic particle . in multi - layer graphenes , the interlayer coupling makes a complex structure around the band touching . the electronic properties of graphene bilayer were theoretically studied for the band structure @xcite and the transport properties.@xcite for few - layered graphenes of more than two stacks , the electronic structure is investigated theoretically in a @xmath3 approximation,@xcite a density functional calculation,@xcite and a tight - binding model.@xcite on the experimental side , the band structures of graphenes from one to four layers were recently measured using angle - resolved photoemission spectroscopy.@xcite the orbital magnetism in graphene - based systems was first studied for a monolayer as a simple model to explain the large diamagnetism of graphite.@xcite it was found that the susceptibility becomes highly diamagnetic at @xmath4 ( band touching point ) even though the density of states vanishes there .. Please generate the next two sentences of the article

the calculation was extended to graphite @xcite and to few - layered graphenes as a model of graphite intercalation compounds.@xcite the fermi surface of the graphite is known to be trigonally warped around the band touching point @xcite and the effect of the warping on magnetization was discussed within the perturbational approach.@xcite recently , the disorder effects on the magnetic oscillation @xcite and on the susceptibility @xcite were studied for the monolayer graphene . here we present a systematic study on the orbital magnetism for multilayer graphenes with arbitrary layer numbers in the effective mass approximation .

Suppose that you have an abstract for a scientific paper: it is shown that fractional derivatives of the ( integrated ) invariant measure of the feigenbaum map at the onset of chaos have power - law tails in their cumulative distributions , whose exponents can be related to the spectrum of singularities @xmath0 . this is a new way of characterizing multifractality in dynamical systems , so far applied only to multifractal random functions ( frisch and matsumoto ( _ j . stat . phys . _ * 108*:1181 , 2002 ) ) . the relation between the thermodynamic approach ( vul , sinai and khanin ( _ russian math . surveys _ * 39*:1 , 1984 ) ) and that based on singularities of the invariant measures is also examined . the theory for fractional derivatives is developed from a heuristic point view and tested by very accurate simulations . _ j. stat . phys . in press _ * keywords : * chaotic dynamics , multifractals , thermodynamic formalism . . And you have already written the first three sentences of the full article: recently a new method for analyzing multifractal functions @xmath1 was introduced @xcite . it exploits the fact that the fractional derivative of order @xmath2 ( denoted here by @xmath3 ) of @xmath1 has , for a suitable range of @xmath2 , a power - law tail in its cumulative probability @xmath4 the exponent @xmath5 is the unique solution of the equation @xmath6 where @xmath7 is the scaling exponent associated to the behavior at small separations @xmath8 of the structure function of order @xmath9 , i.e. @xmath10 . it was also shown that the actual observability of the power - law tail when multifractality is restricted to a finite range of scales is controlled by how much @xmath7 departs from linear dependence on @xmath9 . the larger this departure. Please generate the next two sentences of the article

the easier it is to observe multifractality . so far the theory of such power - law tails has been developed only for synthetic random functions , in particular the random multiplicative process @xcite for which kesten - type maps @xcite and large deviations theory can be used .

Suppose that you have an abstract for a scientific paper: heating mechanisms of the solar corona will be investigated at the high - altitude solar observatory lomnicky peak of the astronomical institute of sas ( slovakia ) using its mid - size lyot coronagraph and post - focal instrument secis provided by astronomical institute of the university of wrocaw ( poland ) . the data will be studied with respect to the energy transport and release responsible for heating the solar corona to temperatures of mega - kelvins . in particular investigations will be focused on detection of possible high - frequency mhd waves in the solar corona . the scientific background of the project , technical details of the secis system modified specially for the lomnicky peak coronagraph , and inspection of the test data are described in the paper . . And you have already written the first three sentences of the full article: for more than 60 years it has been well known that the quiet solar corona is heated to a temperature of about 12 million kelvins while the visible surface of the sun is roughly 250 times cooler ( grotrian 1939 ; edlen 1942 ; phillips , 1995 ) . it has been also recognized that magnetic fields or waves play a key rle in the heating of the solar corona so that somehow convective energy in the photosphere is converted to thermal energy in the corona via magnetic fields or wave energy . the primary energy source for this heating must lie in the convection zone below the solar photosphere ( e.g. bray et al . , 1991 ; golub & pasachoff 1998 ; aschwanden 2004 ) where there is 100 times as much energy available than that required to heat the corona ( @xmath0300w / m@xmath1 : withbroe & noyes 1977 , aschwanden 2001 ) . currently , the debate centres on whether the energy to heat the corona derives from dissipation of magneto - hydrodynamic ( mhd ) waves ( e.g. hollweg , 1981 ) or from numerous small - scale magnetic reconnection events giving rise to nanoflares ( parker , 1988 , aschwanden 2004 ) .. Please generate the next two sentences of the article

it has been found theoretically that the interaction of the magnetic field with convective flows in or below the photosphere can produce two types of magnetic disturbances in coronal structures . firstly , the buffeting of magnetic flux concentrations in the photosphere by granulation generates mhd waves which can propagate into magnetic flux tubes and dissipate their energy in the chromosphere or corona ( e.g. ofman et al . 1998 ) .

Suppose that you have an abstract for a scientific paper: this study presents miscellaneous properties of pseudo - factorials , which are numbers whose recurrence relation is a twisted form of that of usual factorials . these numbers are associated with special elliptic functions , most notably , a dixonian and a weierstra function , which parametrize the fermat cubic curve and are relative to a hexagonal lattice . a continued fraction expansion of the ordinary generating function of pseudo - factorials , first discovered empirically , is established here . this article also provides a characterization of the associated orthogonal polynomials , which appear to form a new family of `` elliptic polynomials '' , as well as various other properties of pseudo - factorials , including a hexagonal lattice sum expression and elementary congruences . . And you have already written the first three sentences of the full article: start from the innocuous looking recurrence , @xmath0 which determines a sequence of integers with initial values @xmath1 these numbers will be called _ pseudo - factorials _ , since the omission of the sign alternation @xmath2 in equation determines the sequence of factorials , @xmath3 at the suggestion of one of us ( bacher , october 2004 ) , they have been included as sequence * a098777 * in the _ on - line encyclopedia of integer sequences _ @xcite , which is brilliantly maintained by sloane and a gang of dedicated volunteers . the purpose of this note is to show that these numbers , though not classical , have a host of interesting properties . the _ exponential generating function _ , @xmath4 is fundamental to our treatment . ( the fact that the absolute values @xmath5 are dominated by factorials implies that @xmath6 is analytic at least in @xmath7 . ). Please generate the next two sentences of the article

we first elucidate the relation between @xmath6 and elliptic functions of a kind introduced by alfred cardew dixon in 1890 ( _ vide _ @xcite ) , then show the reduction to the more common weierstra framework of @xmath8functions : this forms the subject of sections [ dixon - sec ] and [ weier - sec ] .

Suppose that you have an abstract for a scientific paper: recent results on minijet production in nuclear collisions at the rhic and lhc energies are reviewed . initial conditions of the qgp at @xmath0 @xmath1 , especially parton chemistry , thermalization and net baryon number - to - entropy ratio are discussed . also , contribution of minijets from a hard bfkl - pomeron ladder will be estimated . = -1 cm = -1 cm = 16.5 cm = 22.8 cm * minijets in ultrarelativistic heavy ion collisions at rhic and lhc * k.j.eskola _ cern / th , ch-1211 geneve 23 , switzerland _ . And you have already written the first three sentences of the full article: particle and transverse energy production in the central rapidity region of heavy ion collisions can be treated as a combination of hard / semihard parton production and soft particle production . with increasing energies , the semihard qcd - processes are expected to become increasingly important . this is due to two reasons : firstly , already in @xmath2 collisions the rapid rise of the total and inelastic cross sections can be explained by copious production of semihard partons , _ minijets _ , with transverse momenta @xmath3 gev @xcite . this is also expected to happen in @xmath4 collisions at very high energies .. Please generate the next two sentences of the article

secondly , the semihard particle production scales as @xmath5 , so that for large nuclei the importance of semihard partons is increased further @xcite . the soft , non - perturbative , particle production in ultrarelativistic heavy ion collisions can be modelled _

Suppose that you have an abstract for a scientific paper: in this article we present a review of the radon transform and the instability of the tomographic reconstruction process . we show some new mathematical results in tomography obtained by a variational formulation of the reconstruction problem based on the minimization of a mumford - shah type functional . finally , we exhibit a physical interpretation of this new technique and discuss some possible generalizations . i _ keywords _ : radon transform ; integral geometry ; image segmentation ; calculus of variations . . And you have already written the first three sentences of the full article: the primary goal of tomography is to determine the internal structure of an object without cutting it , namely using data obtained by methods that leave the object under investigation undamaged . these data can be obtained by exploiting the interaction between the object and various kinds of probes including x - rays , electrons , and many others . after its interaction with the object under investigation , the probe is detected to produce what we call a projected distribution or tomogram , see fig .. Please generate the next two sentences of the article

[ fig : profiles ] . tomography is a rapidly evolving field for its broad impact on issues of fundamental nature and for its important applications such as the development of diagnostic tools relevant to disparate fields , such as engineering , biomedical and archaeometry .

Suppose that you have an abstract for a scientific paper: we present an elementary proof concerning reciprocal transmittances and reflectances . the proof is direct , simple , and valid for the diverse objects that can be absorptive and induce diffraction and scattering , as long as the objects respond linearly and locally to electromagnetic waves . the proof enables students who understand the basics of classical electromagnetics to grasp the physical basis of reciprocal optical responses . in addition , we show an example to demonstrate reciprocal response numerically and experimentally . . And you have already written the first three sentences of the full article: reciprocity , which was first found by lorentz at the end of 19th century , has a long history@xcite and has been derived in several formalisms . there are two typical reciprocal configurations in optical responses as shown in fig . the configurations in figs .. Please generate the next two sentences of the article

[ fig1](a ) and [ fig1](b ) are transmission reciprocal and those in figs . [ fig1](a ) and [ fig1](c ) are reflection reciprocal . as shown in fig .

Suppose that you have an abstract for a scientific paper: we continue our work on developing techniques for studying turbulence with spectroscopic data . we show that doppler - broadened absorption spectral lines , in particularly , saturated absorption lines , can be used within the framework of the earlier - introduced technique termed the velocity coordinate spectrum ( vcs ) . the vcs relates the statistics of fluctuations along the velocity coordinate to the statistics of turbulence , thus it does not require spatial coverage by sampling directions in the plane of the sky . we consider lines with different degree of absorption and show that for lines of optical depth less than one , our earlier treatment of the vcs developed for spectral emission lines is applicable , if the optical depth is used instead of intensity . this amounts to correlating the logarithms of absorbed intensities . for larger optical depths and saturated absorption lines , we show , that the amount of information that one can use is , inevitably , limited by noise . in practical terms , this means that only wings of the line are available for the analysis . in terms of the vcs formalism , this results in introducing an additional window , which size decreases with the increase of the optical depth . as a result , strongly saturated absorption lines carry the information only about the small scale turbulence . nevertheless , the contrast of the fluctuations corresponding to the small scale turbulence increases with the increase of the optical depth , which provides advantages for studying turbulence combining lines with different optical depths . we show that , eventually , at very large optical depths the lorentzian profile of the line gets important and extracting information on velocity turbulence , gets impossible . combining different absorption lines one can tomography turbulence in the interstellar gas in all its complexity . And you have already written the first three sentences of the full article: turbulence is a key element of the dynamics of astrophysical fluids , including those of interstellar medium ( ism ) , clusters of galaxies and circumstellar regions . the realization of the importance of turbulence induces sweeping changes , for instance , in the paradigm of ism . it became clear , for instance , that turbulence affects substantially star formation , mixing of gas , transfer of heat .. Please generate the next two sentences of the article

observationally it is known that the ism is turbulent on scales ranging from aus to kpc ( see armstrong et al 1995 , elmegreen & scalo 2004 ) , with an embedded magnetic field that influences almost all of its properties . the issue of quantitative descriptors that can characterize turbulence is not a trivial one ( see discussion in lazarian 1999 and ref . therein ) .

Suppose that you have an abstract for a scientific paper: an approach is proposed to nuclear pairing at finite temperature and angular momentum , which includes the effects of the quasiparticle - number fluctuation and dynamic coupling to pair vibrations within the self - consistent quasiparticle random - phase approximation . the numerical calculations of pairing gaps , total energies , and heat capacities are carried out within a doubly folded multilevel model as well as several realistic nuclei . the results obtained show that , in the region of moderate and strong couplings , the sharp transition between the superconducting and normal phases is smoothed out , causing a thermal pairing gap , which does not collapse at a critical temperature predicted by the conventional bardeen - cooper - schrieffer s ( bcs ) theory , but has a tail extended to high temperatures . the theory also predicts the appearance of a thermally assisted pairing in hot rotating nuclei . . And you have already written the first three sentences of the full article: the effect of temperature and angular momentum on pairing properties is an interesting subject in the study of nuclear structure . because of its simplicity , the bcs theory is often used , which offers a good description of pairing correlation in the macroscopic systems such as metallic superconductors . it predicts a collapse of the pairing gap at @xmath0 , which signals the sharp superfluid - normal ( sn ) phase transition at finite temperature .. Please generate the next two sentences of the article

the bcs theory , however , ignores quantal and thermal fluctuations , which are significant in finite small systems . therefore , it needs to be corrected for the application to finite nuclei .

Suppose that you have an abstract for a scientific paper: we present observations of the 5@xmath04@xmath1 transition of water vapor _ at 325.15 ghz _ taken with the cso telescope towards orion irc2 . the emission is more extended than that of other molecular species such as ch@xmath2oh . however , it is much less extended than the emission of water vapor at 183.31 ghz reported by cernicharo et al ( 1994 ) . a comparison of the line intensities at 325.15 ghz and 183.31 ghz puts useful constraints on the density and temperature of the emitting regions and allows an estimate of h@xmath3o abundance , x(h@xmath3o ) , of @xmath410@xmath5 in the plateau and @xmath410@xmath6 - 10@xmath7 in the ridge . 21.75 cm -0.5 cm = 20pt ism : molecules ism : individual ( orion irc2 ) line : profiles masers radio lines : ism submillimeter . And you have already written the first three sentences of the full article: water vapor is an important molecule for the chemistry of interstellar and circumstellar clouds . the 6@xmath8 - 5@xmath9 masing transition of h@xmath3o at 22 ghz , which arises from levels around 700k , has been used since its detection by cheung et al . ( 1969 ) to trace high excitation gas around star forming regions and evolved stars .. Please generate the next two sentences of the article

the size of the emitting regions at that frequency is typically of the order of a few milliarcseconds ( a few 10@xmath10 cm ) . hence , no information has been obtained from this line on the role of h@xmath3o at large spatial scales .

Suppose that you have an abstract for a scientific paper: we study a new class of networks , generated by sequences of letters taken from a finite alphabet consisting of @xmath0 letters ( corresponding to @xmath0 types of nodes ) and a fixed set of connectivity rules . recently , it was shown how a binary alphabet might generate threshold nets in a similar fashion [ hagberg et al . , phys . rev . e 74 , 056116 ( 2006 ) ] . just like threshold nets , sequence nets in general possess a modular structure reminiscent of everyday life nets , and are easy to handle analytically ( i.e. , calculate degree distribution , shortest paths , betweenness centrality , etc . ) . exploiting symmetry , we make a full classification of two- and three - letter sequence nets , discovering two new classes of two - letter sequence nets . the new sequence nets retain many of the desirable analytical properties of threshold nets while yielding richer possibilities for the modeling of everyday life complex networks more faithfully . . And you have already written the first three sentences of the full article: threshold nets are obtained by assigning a weight @xmath1 , from a distribution @xmath2 , to each of @xmath3 nodes and connecting any two nodes @xmath4 and @xmath5 whose combined weights exceed a certain threshold , @xmath6 : @xmath7 @xcite . threshold nets can be produced of ( almost ) arbitrary degree distributions , including scale - free , by judiciously choosing the weight distribution @xmath2 and the threshold @xmath6 , and they encompass an astonishingly wide variety of important architectures : from the star graph ( a simple cartoon " model of scale - free graphs consisting of a single hub ) with its low density of links , @xmath8 , to the complete graph . studied extensively in the graph - theoretical literature @xcite , they have recently come to the attention of statistical and non - linear physicists due to the beautiful work of hagberg , swart , and schult @xcite . , and ( b ) its box representation , highlighting modularity .. Please generate the next two sentences of the article

nodes are added one at a time from bottom to top , @xmath9 s on the left and @xmath10 s on the right.,scaledwidth=35.0% ] hagberg _ et al_. , exploit the fact that threshold graphs may be more elegantly encoded by a two - letter sequence , corresponding to two types of nodes , @xmath9 and @xmath10 @xcite . as new nodes are introduced , according to a prescribed sequence , nodes of type @xmath9 connect to none of the existing nodes , while nodes of type @xmath10 connect to all of the nodes , of either type : @xmath11 and @xmath12 . in fig .

Suppose that you have an abstract for a scientific paper: the majority of active galactic nuclei ( agn ) observed by _ xmm - newton _ reveal narrow fe k@xmath0 lines at @xmath1 6.4 kev , due to emission from cold ( neutral ) material . there is an x - ray baldwin effect in type i agn , in that the equivalent width of the line decreases with increasing luminosity , with weighted linear regression giving ew @xmath2 l@xmath3 ( spearman rank probability of @xmath4 99.9 per cent ) . with current instrumental capabilities it is not possible to determine the precise origin for the narrow line , with both the broad line region and putative molecular torus being possibilities . a possible explanation for the x - ray baldwin effect is a decrease in covering factor of the material forming the fluorescence line . [ firstpage ] galaxies : active x - rays : galaxies quasars : emission lines . And you have already written the first three sentences of the full article: as the number of agn surveyed by _ xmm - newton _ and _ chandra _ increases , it is becoming apparent that the vast majority show evidence for a narrow ( unresolved by _ xmm _ ) line at @xmath1 6.4 kev , due to emission from neutral iron ; recent papers describing such lines include gondoin ( 2003 ; ngc 3227 ) , page ( 2003 ; mrk 896 ) , pounds ( 2003 ; mrk 766 ) , petrucci ( 2002 ; mrk 841 ) , turner ( 2002 ; ngc 3516 ) , obrien ( 2001 ; mrk 359 ) , reeves ( 2001 ; mrk 205 ) and many others . in a number of cases ( e.g. , ngc 3783 kaspi 2002 ; ngc 5548 yaqoob 2001 ) the lines have actually been resolved by _. Please generate the next two sentences of the article

, with fwhm velocities typically @xmath5 5000 km s@xmath6 . iron k@xmath0 emission was first identified as a common feature by _ ginga _ ( pounds 1990 ; nandra & pounds 1994 ) ; observations by _ asca _ tended to find relatively broad profiles , although re - analysis of some of the data indicates that the lines _ may _ be narrower than originally measured ( lubinski & zdziarski 2001 ) .

Suppose that you have an abstract for a scientific paper: we report on a simple and robust technique to generate a dispersive signal which serves as an error signal to electronically stabilize a monomode cw laser emitting around an atomic resonance . we explore nonlinear effects in the laser beam propagation through a resonant vapor by way of spatial filtering . the performance of this technique is validated by locking semiconductor lasers to the cesium and rubidium @xmath0 line and observing long - term reduction of the emission frequency drifts , making the laser well adapted for many atomic physics applications . . And you have already written the first three sentences of the full article: the use of lasers in atomic physics often demands long term stability of the central frequency of the light emission . for metrological applications the stabilization technique @xcite should be very carefully chosen and applied , frequently controlling the laser linewidth and avoiding to introduce any artificial shift in the laser emission frequency . moreover , locking to the center of an atomic or molecular transition usually requires modulation techniques and lock - in detection . on the other hand , for many scientific and technical applications one only needs to avoid frequency drifts and , sometimes , the desired laser frequency does not lay at the maximum of an atomic lineshape , but rather at a displaced frequency , as for instance , when operating an optical cooler @xcite . for such applications. Please generate the next two sentences of the article

a few simple and reliable techniques were developed @xcite and allow on e to deal with lasers in various long run experiments . the main idea behind many of these techniques is to generate a dispersive lineshape that will produce an error signal . in particular , for the dichroic atomic vapor laser lock ( davll ) @xcite and its variants

Suppose that you have an abstract for a scientific paper: although finding numerically the quasinormal modes of a nonrotating black hole is a well - studied question , the physics of the problem is often hidden behind complicated numerical procedures aimed at avoiding the direct solution of the spectral system in this case . in this article , we use the exact analytical solutions of the regge - wheeler equation and the teukolsky radial equation , written in terms of confluent heun functions . in both cases , we obtain the quasinormal modes numerically from spectral condition written in terms of the heun functions . the frequencies are compared with ones already published by andersson and other authors . a new method of studying the branch cuts in the solutions is presented the epsilon - method . in particular , we prove that the mode @xmath0 is not algebraically special and find its value with more than 6 firm figures of precision for the first time . the stability of that mode is explored using the @xmath1 method , and the results show that this new method provides a natural way of studying the behavior of the modes around the branch cut points . . And you have already written the first three sentences of the full article: the study of quasinormal modes ( qnms ) of a black hole ( bh ) has long history @xcite . the reason behind this interest is that the qnms offer a direct way of studying the key features of the physics of compact massive objects , without the complications of the full 3d general relativistic simulations . for example , by comparing the theoretically obtained gravitational qnms with the frequencies of the gravitational waves , one can confirm or refute the nature of the central engines of many astrophysical objects , since those modes differ for the different types of objects black holes , superspinars ( naked singularities ) , neutron stars , black hole mimickers etc . @xcite . to find the qnms. Please generate the next two sentences of the article

, one needs to solve the second - order linear differential equations describing the linearized perturbations of the metric : the regge - wheeler equation ( rwe ) and the zerilli equation for the schwarzschild metric or the teukolsky radial equation ( tre ) for the kerr metric and to impose the appropriate boundary conditions the so - called black hole boundary conditions ( waves going simultaneously into the horizon and into infinity)@xcite . additionally , one requires a regularity condition for the angular part of the solutions .

Suppose that you have an abstract for a scientific paper: in this paper we discuss bayesian nonconvex penalization for sparse learning problems . we explore a nonparametric formulation for latent shrinkage parameters using subordinators which are one - dimensional lvy processes . we particularly study a family of continuous compound poisson subordinators and a family of discrete compound poisson subordinators . we exemplify four specific subordinators : gamma , poisson , negative binomial and squared bessel subordinators . the laplace exponents of the subordinators are bernstein functions , so they can be used as sparsity - inducing nonconvex penalty functions . we exploit these subordinators in regression problems , yielding a hierarchical model with multiple regularization parameters . we devise ecme ( expectation / conditional maximization either ) algorithms to simultaneously estimate regression coefficients and regularization parameters . the empirical evaluation of simulated data shows that our approach is feasible and effective in high - dimensional data analysis . . And you have already written the first three sentences of the full article: variable selection methods based on penalty theory have received great attention in high - dimensional data analysis . a principled approach is due to the lasso of @xcite , which uses the @xmath0-norm penalty . @xcite also pointed out that the lasso estimate can be viewed as the mode of the posterior distribution .. Please generate the next two sentences of the article

indeed , the @xmath1 penalty can be transformed into the laplace prior . moreover , this prior can be expressed as a gaussian scale mixture . this has thus led to bayesian developments of the lasso and its variants @xcite .

Suppose that you have an abstract for a scientific paper: we report on our search for the optical counterparts of the southern hemisphere anomalous x - ray pulsar 1e1048.1 - 5937 and the radio - quiet neutron stars in supernova remnants puppis a , rcw 103 , and pks 1209 - 52 . the observations were carried out with the new mit / cfa magic camera on the magellan - i 6.5 m telescope in chile . we present deep multiband optical images of the x - ray error circles for each of these targets and discuss the resulting candidates and limits . # 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in . And you have already written the first three sentences of the full article: * the anomalous x - ray pulsars ( axps ) * are a group of x - ray pulsars whose spin periods fall in a narrow range ( @xmath0 s ) , whose x - ray spectra are very soft , and which show no evidence that they accrete from a binary companion ( see mereghetti 1999 for a recent review ) . these objects may be isolated neutron stars with extremely strong ( @xmath1 g ) surface magnetic fields , or they may be accreting from a `` fallback '' accretion disk . optical measurements could potentially help discriminate between these models . an optical counterpart to one axp , 4u 0142 + 61 , has recently been identified and shown to have peculiar optical colors ( hulleman et al .. Please generate the next two sentences of the article

* the radio - quiet neutron stars ( rqnss ) * are a group of compact x - ray sources found near the center of young supernova remnants . their x - ray spectra are roughly consistent with young , cooling neutron stars , but they show no evidence for the non - thermal emission associated with `` classical '' young pulsars like the crab ( see brazier & johnston 1999 for a review )

Suppose that you have an abstract for a scientific paper: we consider a three - dimensional chaotic system consisting of the suspension of arnold s cat map coupled with a clock via a weak dissipative interaction . we show that the coupled system displays a synchronization phenomenon , in the sense that the relative phase between the suspension flow and the clock locks to a special value , thus making the motion fall onto a lower dimensional attractor . more specifically , we construct the attractive invariant manifold , of dimension smaller than three , using a convergent perturbative expansion . moreover , we compute via convergent series the lyapunov exponents , including notably the central one . the result generalizes a previous construction of the attractive invariant manifold in a similar but simpler model . the main novelty of the current construction relies in the computation of the lyapunov spectrum , which consists of non - trivial analytic exponents . some conjectures about a possible smoothening transition of the attractor as the coupling is increased are also discussed . * _ keywords : _ * partially hyperbolic systems ; anosov systems ; synchronization ; phase - locking ; lyapunov exponents ; fractal attractor ; srb measure ; tree expansion ; perturbation theory . . And you have already written the first three sentences of the full article: synchronization in chaotic systems is a surprising phenomenon , which recently received a lot of attention , see e.g. @xcite . even though the heuristic theory and the classification of the synchronization phenomena are well studied and reasonably well understood , a mathematically rigorous theory is still lacking . generally speaking , a standard difficulty lies in the fact that the phenomenon involves the dynamics of non - uniformly chaotic systems , typically consisting of different sub - systems , whose long - time behavior depends crucially on the sign of the `` central '' lyapunov exponents , i.e. of those exponents that are zero in the case of zero coupling , and become possibly non - trivial in the presence of interactions among the sub - systems .. Please generate the next two sentences of the article

the mathematical control of such exponents is typically very hard . progress in their computation is a fundamental preliminary step for the construction of the srb measure of chains or lattices of chaotic flows , which may serve as toy models for extensive chaotic systems out - of - equilibrium ( i.e. they may serve as standard models for non - equilibrium steady states in non - equilibrium statistical mechanics ) . in a previous paper @xcite

Suppose that you have an abstract for a scientific paper: in many analyses in high energy physics , attempts are made to remove the effects of detector smearing in data by techniques referred to as `` unfolding '' histograms , thus obtaining estimates of the true values of histogram bin contents . such unfolded histograms are then compared to theoretical predictions , either to judge the goodness of fit of a theory , or to compare the abilities of two or more theories to describe the data . when doing this , even informally , one is testing hypotheses . however , a more fundamentally sound way to test hypotheses is to smear the theoretical predictions by simulating detector response and then comparing to the data without unfolding ; this is also frequently done in high energy physics , particularly in searches for new physics . one can thus ask : to what extent does hypothesis testing after unfolding data materially reproduce the results obtained from testing by smearing theoretical predictions ? we argue that this `` bottom - line - test '' of unfolding methods should be studied more commonly , in addition to common practices of examining variance and bias of estimates of the true contents of histogram bins . we illustrate bottom - line - tests in a simple toy problem with two hypotheses . . And you have already written the first three sentences of the full article: in high energy physics ( hep ) , unfolding ( also called unsmearing ) is a general term describing methods that attempt to take out the effect of smearing resolution in order to obtain a measurement of the true underlying distribution of a quantity . typically the acquired data ( distorted by detector response , inefficiency , etc . ) are binned in a histogram .. Please generate the next two sentences of the article

the result of some unfolding procedure is then a new histogram with estimates of the true mean bin contents prior to smearing and inefficiency , along with some associated uncertainties . it is commonly assumed that such unfolded distributions are useful scientifically for comparing data to one or more theoretical predictions , or even as quantitative measurements to be propagated into further calculations .

Suppose that you have an abstract for a scientific paper: here we report our recent study on the spectral energy distribution ( sed ) of the high frequency bllac object mrk421 in different luminosity states . we used a full - fledged @xmath0-minimization procedure instead of more commonly used `` eyeball '' fit to model the observed flux of the source ( from optical to very high energy ) , with a synchrotron - self - compton ( ssc ) emission mechanism . our study shows that the synchrotron power and peak frequency remain constant with varying source activity , and the magnetic field ( @xmath1 ) decreases with the source activity while the break energy of electron spectrum ( @xmath2 ) and the doppler factor ( @xmath3 ) increase . since a lower magnetic field and higher density of electrons result in increased electron - photon scattering efficiency , the compton power increases , so does the total emission . . And you have already written the first three sentences of the full article: active galactic nuclei ( agn ) involve the most powerful , steady sources of luminosity in the universe . it is believed that the center core of agn consist of super massive black hole ( smbh ) surrounded by an accretion disk . in some cases powerful collimated jets are found in agn , perpendicular to the plane of accretion disk .. Please generate the next two sentences of the article

the origin of jets are still unclear . agns whose jets are viewed at a small angle to its axis are called blazars . the overall ( radio to @xmath4-ray ) spectral energy distribution ( sed ) of blazars shows two broad non - thermal continuum peaks .

Suppose that you have an abstract for a scientific paper: trace distance is available to capture the dynamical information of the unital aspect of a quantum process . however , it can not reflect the non - unital part . so , the non - divisibility originated from the non - unital aspect can not be revealed by the corresponding measure based on the trace distance . we provide a measure of non - unital non - markovianity of quantum processes , which is a supplement to breuer - laine - piilo ( blp ) non - markovianity measure . a measure on the degree of the non - unitality is also provided . . And you have already written the first three sentences of the full article: understanding and characterizing general features of the dynamics of open quantum systems is of great importance to physics , chemistry , and biology @xcite . the non - markovian character is one of the most central aspects of an open quantum process , and attracts increasing attentions @xcite . markovian dynamics of quantum systems is described by a quantum dynamical semigroup @xcite , and often taken as an approximation of realistic circumstances with some very strict assumptions . meanwhile ,. Please generate the next two sentences of the article

exact master equations , which describe the non - markovian dynamics , are complicated @xcite . based on the infinitesimal divisibility in terms of quantum dynamical semigroup , wolf _ et al . _ provided a model - independent way to study the non - markovian features @xcite .

Suppose that you have an abstract for a scientific paper: we introduce a microscopic model aimed at describing superconductivity that can possibly exist in the background of a magnetic texture called spin - vortex checkerboard " . this texture was proposed previously as a possible alternative to stripes to interpret the experimental phenomenology of spin and charge modulations in 1/8-doped lanthanum cuprates . the model involves two kinds of interacting fermionic excitations residing in spin - rich and spin - poor regions of the modulated structure . it is a generalization of another model developed earlier for the so - called grid checkerboard " . we present the mean - field solution of the model , from which we obtain model s predictions for the temperature evolution of the superconducting gap , compare these predictions with available experiments on high-@xmath0 cuprate superconductors and find a good overall agreement . . And you have already written the first three sentences of the full article: interplay between superconductivity and the onset of electronic spin and charge modulations in cuprate superconductors remains one of the intriguing and unresolved issues in the field of high - temperature superconductivity . manifestations of electronic modulations are reported in a broad doping range for several families of cuprates most noticeably around the doping level of 1/8@xcite . for 1/8-doped lanthanum cuprates , the modulated structure is widely believed to exhibit one - dimensional pattern often referred to as stripes " @xcite . yet the principal aspects of the same experimental evidence are also consistent with the possibility of two - dimensional modulations called checkerboards " @xcite . the experiment - based arguments discriminating between stripes and checkerboards in 1/8-doped lanthanum cuprates are at present rather indirect . at the same time. Please generate the next two sentences of the article

, the issue can not be resolved on purely theoretical grounds , because it requires accuracy of the calculations of the ground state energy not achievable by first - principles theories . the checkerboard was , initially , less popular as an interpretation of experiments , in part , because of the perception that it inhibits the electronic transport in all lattice directions and hence prevents the onset of superconductivity as well .

Suppose that you have an abstract for a scientific paper: the motion of free nearby test particles relative to a stable equatorial circular geodesic orbit about a kerr source is investigated . it is shown that the nonlinear generalized jacobi equation can be transformed in this case to an autonomous form . tidal dynamics beyond the critical speed @xmath0 is studied . we show , in particular , that a free test particle vertically launched from the circular orbit parallel or antiparallel to the kerr rotation axis is tidally accelerated if its initial relative speed exceeds @xmath1 . possible applications of our results to high - energy astrophysics are briefly mentioned . . And you have already written the first three sentences of the full article: the purpose of this paper is to study some aspects of the relative motion of free test particles in the gravitational field of a rotating astronomical source . imagine , for the sake of concreteness , a free mass @xmath2 in orbit about the central source of mass @xmath3 and angular momentum @xmath4 , where @xmath2 , @xmath5 and @xmath4 are constants . let @xmath6 be the proper time along the orbit of mass @xmath2 and @xmath7 be a local orthonormal tetrad system that is parallel transported along this path . here @xmath8 is the four - velocity vector of @xmath2 and @xmath9 , @xmath10 , are unit spacelike gyro directions that determine the local spatial frame of @xmath2 .. Please generate the next two sentences of the article

we employ units such that @xmath11 throughout ; moreover , the signature of the metric is @xmath12 in our convention . suppose that at @xmath13 a probe is launched from @xmath2 and for some time @xmath14 the motion of the probe is closely monitored by observers comoving with @xmath2 . to study relative motion in an invariant manner within the context of general relativity , the quasi - inertial fermi normal coordinate system @xcite is indispensable as it most closely corresponds to actual observations .

Suppose that you have an abstract for a scientific paper: a new fixed - target experiment at the cern sps accelerator is proposed that will use decays of charm mesons to search for heavy neutral leptons ( hnls ) , which are right - handed partners of the standard model neutrinos . the existence of such particles is strongly motivated by theory , as they can simultaneously explain the baryon asymmetry of the universe , account for the pattern of neutrino masses and oscillations and provide a dark matter candidate . cosmological constraints on the properties of hnls now indicate that the majority of the interesting parameter space for such particles was beyond the reach of the previous searches at the ps191 , bebc , charm , ccfr and nutev experiments . for hnls with mass below @xmath0gev , the proposed experiment will improve on the sensitivity of previous searches by four orders of magnitude and will cover a major fraction of the parameter space favoured by theoretical models . the experiment requires a 400gev proton beam from the sps with a total of @xmath1 protons on target , achievable within five years of data taking . the proposed detector will reconstruct exclusive hnl decays and measure the hnl mass . the apparatus is based on existing technologies and consists of a target , a hadron absorber , a muon shield , a decay volume and two magnetic spectrometers , each of which has a 0.5tm magnet , a calorimeter and a muon detector . the detector has a total length of about 100 m with a 5 m diameter . the complete experimental set - up could be accommodated in cern s north area . the discovery of a hnl would have a great impact on our understanding of nature and open a new area for future research . + cern - spsc-2013 - 024 / spsc - eoi-010 + + + proposal to search for heavy neutral leptons at the sps w. bonivento@xmath2 , a. boyarsky@xmath3 , h. dijkstra@xmath4 , u. egede@xmath5 , m. ferro - luzzi@xmath4 , b. goddard@xmath4 , a. golutvin@xmath5 , d. gorbunov@xmath6 , r. jacobsson@xmath4 , j. panman@xmath4 , m. .... And you have already written the first three sentences of the full article: the new scalar particle with mass @xmath10@xmath11 gev ( atlas ) @xcite , @xmath12 gev ( cms ) @xcite , recently found at the lhc , has properties consistent with those of the long - awaited higgs boson of the standard model ( sm ) @xcite . this discovery implies that the landau pole in the higgs self - interaction is well above the quantum gravity scale @xmath13 gev ( see , e.g. ref . moreover , within the sm , the vacuum is stable , or metastable with a lifetime exceeding that of the universe by many orders of magnitude @xcite . without the addition of any further new particles ,. Please generate the next two sentences of the article

the sm is therefore an entirely self - consistent , weakly - coupled , effective field theory all the way up to the planck scale ( see refs . @xcite for a recent discussion ) . nevertheless , it is clear that the sm is incomplete . besides a number of fine - tuning problems ( such as the hierarchy and strong cp problems ) , the sm is in conflict with the observations of non - zero neutrino masses , the excess of matter over antimatter in the universe , and the presence of non - baryonic dark matter .

Suppose that you have an abstract for a scientific paper: we study a noisy kuramoto - sivashinsky ( ks ) equation which describes unstable surface growth and chemical turbulence . it has been conjectured that the universal long - wavelength behavior of the equation , which is characterized by scale - dependent parameters , is described by a kardar - parisi - zhang ( kpz ) equation . we consider this conjecture by analyzing a renormalization - group equation for a class of generalized kpz equations . we then uniquely determine the parameter values of the kpz equation that most effectively describes the universal long - wavelength behavior of the noisy ks equation . _ introduction. _ eddy viscosity in turbulence , which can explain how a vortex pattern emerges in a non - uniform turbulent flow , depends on the observed length scales @xcite . as exemplified by the richardson law @xcite , there are cases in which a parameter of a macroscopic description is not given as a definite value , but is rather expressed as a function of length scale . another example of scale - dependent parameters has been observed in one- or two- dimensional fluid dynamics , where the viscosity is not uniquely defined in the hydrodynamic description @xcite . here , it seems reasonable to expect that such scale dependent parameters in a macroscopic description can be reproduced by an effective stochastic system @xcite . in this letter , we attempt to determine the effective stochastic system theoretically when scale - dependent parameters are observed . as the simplest example for scale - dependent parameters , we consider the one - dimensional kardar - parisi - zhang ( kpz ) equation @xcite . it is known that the effective surface tension @xmath0 at a scale @xmath1 for the equation is @xmath2 in the limit @xmath3 , which is similar to the richardson law for turbulence . recently , the kpz equation was rigorously derived from a stochastic many - particle model @xcite , and the so - called kpz class has been extensively discussed both theoretically and experimentally.... And you have already written the first three sentences of the full article: in this section , we review the renormlization group ( rg ) equation for the generalized karder - parisi - zhang ( kpz ) equations . we first define scale - dependent parameters @xmath0 , @xmath69 , @xmath71 , and @xmath72 , and then introduce a perturbation theory leading to the equation for determining them . we start with the generating functional @xmath184 $ ] by which all statistical quantities of the kpz equations are determined . following the martin - siggia - rose - janssen - dedominicis ( msrjd ) formalism @xcite , @xmath184 $ ] is expressed as @xmath185 = \int \mathcal{d } [ h , { i\tilde{h } } ] \exp\biggl[-s[h,{i\tilde{h}};\lambda_0]+\int_{-\infty}^{\infty } d\omega \int_{-\lambda_0}^{\lambda_0 } dk \biggl({j}(k,\omega ) h(-k,-\omega)+ { \tilde{j}}(k,\omega ) { i\tilde{h}}(-k,-\omega ) \biggr ) \biggr ] , \label{eq : generatingfunctional}\ ] ] where @xmath186 is the auxiliary field , @xmath187 and @xmath188 are source fields , and @xmath189 $ ] is the msrjd action for the generalized kpz equation . throughout supplemental material , we use the notation @xmath190 for the fourier transform of @xmath191 for any field a. the action @xmath189 $ ] is explicitly written as @xmath192 = & \frac{1}{2}\int_{-\infty}^{\infty } \frac{d\omega}{2\pi } \int^{\lambda_0}_{-\lambda_0}\frac{d k}{2\pi } \begin{pmatrix } h(-k,-\omega ) & { i\tilde{h}}(-k,-\omega ) \end{pmatrix } g_0^{-1}(k,\omega ) \begin{pmatrix } h(k,\omega ) \\ { i\tilde{h}}(k,\omega ) \end{pmatrix } \nonumber \\ & + \frac{\lambda_0}{2 } \int_{-\infty}^{\infty } \frac{d\omega_1 d\omega_2}{(2\pi)^2 } \int^{\lambda_0}_{-\lambda_0}\frac{d k_1 d k_2}{(2\pi)^2 } k_1 k_2{i\tilde{h } } ( -k_1-k_2,-\omega_1-\omega_2 ) h(k_1 , \omega_1)h(k_2,\omega_2 ) , \label{eq : action}\end{aligned}\ ] ] where @xmath193 is the inverse matrix of the bare propagator @xmath194 here , we consider a coarse - grained description at a cutoff @xmath195 .. Please generate the next two sentences of the article

let us define @xmath196 for any quantity @xmath190 , where @xmath197 is the heaviside step function . the statistical quantities of @xmath198 are described by the generating functional @xmath199 $ ] with replacement of @xmath200 by @xmath201 .

Suppose that you have an abstract for a scientific paper: the thermodynamic and transport properties of the unitary fermi gas at finite temperature @xmath0 are governed by a quantum critical point at @xmath1 and zero density . we compute the universal shear viscosity to entropy ratio @xmath2 in the high - temperature quantum critical regime @xmath3 and find that this strongly coupled quantum fluid comes close to perfect fluidity @xmath4 . using a controlled large-@xmath5 expansion we show that already at the first non - trivial order the equation of state and the tan contact density @xmath6 agree well with the most recent experimental measurements and theoretical luttinger - ward and bold diagrammatic monte carlo calculations . . And you have already written the first three sentences of the full article: the unitary fermi gas is a basic many - body problem which describes strongly interacting fermions ranging from ultracold atoms near a feshbach resonance @xcite to dilute neutron matter . the properties in the dilute limit are independent of the microscopic details of the interaction potential and share a common universal phase diagram . a quantum critical point ( qcp ) at zero temperature governs the critical behavior in the whole phase diagram as a function of temperature @xmath0 , chemical potential @xmath7 , detuning from the feshbach resonance @xmath8 , and magnetic field @xmath9 @xcite . whereas conventional qcps separate two phases of finite density , in our case the density itself is the order parameter which vanishes for @xmath10 and assumes a finite value for @xmath11 @xcite . in the spin balanced case @xmath12 , and at resonance @xmath13 the fermi gas is unitary and scale invariant . in terms of the thermal length @xmath14. Please generate the next two sentences of the article

the density equation of state @xmath15 is a universal function which has been measured experimentally @xcite . the unitary fermi gas becomes superfluid at a universal @xmath16 @xcite , see fig .

Suppose that you have an abstract for a scientific paper: we report on our calculations of the inner - sphere reorganization energy and the interaction of the @xmath0 orbitals within dna oligomers . the exponential decrease of the electronic coupling between the highest and second highest occupied base orbitals of the intrastrand nucleobases in the ( a - t)@xmath1 and ( g - c)@xmath1 oligomers have been found with an increase of the sequence number @xmath2 in the dna structure . we conclude that for realistic estimation of the electronic coupling values between the nucleobases within the dna molecule , a dna chain containing at least four base pairs is required . we estimate the geometry relaxation of the base pairs within the ( a - t)@xmath1 and ( g - c)@xmath1 oligomers ( @xmath3 ) due to their oxidation . the decrease of the inner - sphere reorganization energy with elongation of the oligomer structure participating in the oxidation process have been observed . the maximum degree of geometry relaxation of the nucleobase structures and correspondingly the higher charge density in the oxidized state are found to be located close to the oligomer center . = 1.5truecm . And you have already written the first three sentences of the full article: discovery of charge migration in dna molecules has opened new avenues to investigate various possibilities ranging from its role in the dna oxidative damage and repair @xcite to application of dna in nanoelectronic device developments @xcite . in fact , dna - based molecular electronic devices are expected to operate within the picoseconds range @xcite that can exceed the potential of the present solid state devices . quite expectedly , the dna molecule has become a subject of intense research activities both theoretically @xcite and experimentally @xcite . from all these studies of charge migration in the dna molecule. Please generate the next two sentences of the article

reported as yet , it is clear that there are two mechanisms for transfer of charge depending on the dna structure and transfer parameters : a superexchange charge transfer and the incoherent hopping @xcite . the charge migration leads to the geometry changes in the nucleotides and the surrounding environment , which significantly contribute to the charge migration process . due to the interaction of the @xmath0 orbitals of the nearest neighbor duplexes and insignificant ip difference between them

Suppose that you have an abstract for a scientific paper: we report the observation and systematic investigation of the space charge effect and mirror charge effect in photoemission spectroscopy . when pulsed light is incident on a sample , the photoemitted electrons experience energy redistribution after escaping from the surface because of the coulomb interaction between them ( space charge effect ) and between photoemitted electrons and the distribution of mirror charges in the sample ( mirror charge effect ) . these combined coulomb interaction effects give rise to an energy shift and a broadening which can be on the order of 10 mev for a typical third - generation synchrotron light source . this value is comparable to many fundamental physical parameters actively studied by photoemission spectroscopy and should be taken seriously in interpreting photoemission data and in designing next generation experiments . key words : space charge , mirror charge , photoemission , fermi level shift , fermi level broadening . . And you have already written the first three sentences of the full article: photoemission spectroscopy measures the energy distribution of photo - emitted electrons when materials are irradiated with light @xcite(fig . it is widely used in solid state physics and chemistry for investigating the electronic structure of surface , interface and bulk materials@xcite . recently it has become a prime choice of technique in studying strongly correlated electron systems@xcite , such as high temperature superconductors@xcite .. Please generate the next two sentences of the article

the availability of synchrotron light sources and lasers , combined with the latest advancement of electron energy analyzer , has made a dramatic improvement on the energy resolution of photoemission technique in the last decade ; an energy resolution of @xmath0 5mev or better can now be routinely obtained . these achievements have made it possible to probe intrinsic properties of materials and many - body effects@xcite .

Suppose that you have an abstract for a scientific paper: this report summarizes the progress in the study of higgs physics at a future linear electron positron collider at center - of - mass energies up to about 1000 gev and high luminosity . after the publication of the tesla technical design report @xcite , an extended ecfa / desy study on linear collider physics and detectors was performed . the paper summarizes the status of the studies with main emphasis on recent results obtained in the course of the workshop . . And you have already written the first three sentences of the full article: elucidating the mechanism responsible for electro - weak symmetry breaking is one of the most important tasks of future collider based particle physics . experimental and theoretical indications of a light higgs boson make the precision study of the properties of higgs bosons one of the major physics motivations of a linear collider ( lc ) . both the higgs boson of the standard model ( sm ) and those of extended models will be copiously produced in @xmath0 collisions in various production mechanisms . a large variety of different decay modes can be observed with low backgrounds and high efficiency .. Please generate the next two sentences of the article

these measurements allow us to extract the fundamental parameters of the higgs sector with high precision . the series of ecfa / desy workshops aims at a comprehensive study of the physics case , a determination of the achievable precisions on higgs observables as well as on a fruitful cross - talk between theory , physics simulations and detector layout .

Suppose that you have an abstract for a scientific paper: ground state properties and excited states of ladder - type paraphenylene oligomers are calculated applying semiempirical methods for up to eleven phenylene rings . the results are in qualitative agreement with experimental data . a new scheme to interpret the excited states is developed which reveals the excitonic nature of the excited states . the electron - hole pair of the @xmath0-state has a mean distance of approximately 4 . . And you have already written the first three sentences of the full article: the investigation of @xmath1-conjugated polymers is in many ways affected by the structural disorder in these systems . in contrast , the ladder - type poly - p - phenylenes ( lppp ) @xcite offer the opportunity to study large , rod - like chains of planarised phenylene units . as a consequence , the @xmath1-system might spread out over an entire polymer and a vibronic resolution of the @xmath2 transition is discernible @xcite . in order to deduce some characteristics of the polymeric films @xcite , like the effective conjugation length. Please generate the next two sentences of the article

, several oligomers have been synthesized in the past to study the low - lying electronic excited states of the polymer @xcite . photoconduction in lppp films @xcite has been measured as a function of the energy of the exciting light , too .