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Suppose that you have an abstract for a scientific paper: we extensively develop a method of implementing mean - field calculations for deformed nuclei , using the gaussian expansion method ( gem ) . this gem algorithm has the following advantages : ( i ) it can efficiently describe the energy - dependent asymptotics of the wave functions at large @xmath0 , ( ii ) it is applicable to various effective interactions including those with finite ranges , and ( iii ) the basis parameters are insensitive to nuclide , thereby many nuclei in wide mass range can be handled by a single set of bases . superposing the spherical gem bases with feasible truncation for the orbital angular momentum of the single - particle bases , we obtain deformed single - particle wave - functions to reasonable precision . we apply the new algorithm to the hartree - fock and the hartree - fock - bogolyubov calculations of mg nuclei with the gogny interaction , by which neck structure of a deformed neutron halo is suggested for @xmath1 mg . pacs numbers : 21.60.jz , 21.10.gv , 21.10.dr , 27.30.+t keywords : mean - field calculation ; gaussian expansion method ; axially - symmetric deformation ; finite - range interaction ; deformed neutron halo . And you have already written the first three sentences of the full article: as experimental facilities supply fruitful data on nuclei far off the @xmath2-stability , it has been recognized that theoretical approaches to nuclear structure should be renewed in some respects . one of the key ingredients is wave - function asymptotics at large @xmath0 , which sometimes produces neutron ( proton ) halos in vicinity of the neutron ( proton ) drip line . it is also important to reinvestigate effective interactions , in connection to the magic numbers that are different from those near the @xmath2-stability line .. Please generate the next two sentences of the article

we developed a method for the spherical mean - field calculations @xcite in which the gaussian expansion method ( gem ) @xcite was applied . this method seems suitable to studying the shell structure from stable to drip - line nuclei , owing to its several advantages .

Suppose that you have an abstract for a scientific paper: from the galaxy power spectrum in redshift space , we derive semi - analytical results on the generic degeneracy of galaxy clustering measurements . defining the observables @xmath0 and @xmath1 , ( being @xmath2 the growth function , @xmath3 the bias , @xmath4 the growth rate , and @xmath5 the amplitude of the power spectrum ) , we perform a fisher matrix analysis to forecast the expected precision of these quantities for a euclid - like survey . among the results we found that galaxy surveys have generically a slightly negative correlation between @xmath6 and @xmath7 , and they can always measure @xmath7 about 3.7 to 4.7 times better than @xmath6 . . And you have already written the first three sentences of the full article: future galaxy surveys will provide new opportunities to verify the current standard cosmological model , and also to constrain modified gravity theories , invoked to explain the present accelerated expansion of the universe . before studying general parametrizations of dark energy , its however important to understand first which quantities can be really observed . from this direction recently @xcite shown that cosmological measurements can determine , in addition to the expansion rate @xmath8 , only three additional variables @xmath9 , @xmath10 and @xmath11 , given by @xmath12 with @xmath2 is the growth function , @xmath3 is the galaxy bias with respect to the dark matter density contrast , and @xmath13 is the dark matter density contrast today . the functions @xmath14 ( the anisotropic stress @xmath15 ) and @xmath16 ( the clustering of dark energy @xmath17 ) , describe the impact of the dark energy on cosmological perturbations . in @xcite , a fisher analysis was made using galaxy clustering , weak lensing and supernovae probes , in order to find the expected accuracy with which an euclid - like survey can measure the anisotropic stress @xmath14 , in a model - independent way .. Please generate the next two sentences of the article

+ in this work we want to obtain some results on the intrinsic degeneracy on galaxy clustering measurements , using the quantities @xmath10 and @xmath9 . we use a flat @xmath18cdm fiducial model , with @xmath19 , @xmath20 , @xmath21 , @xmath22 , @xmath23 , @xmath24 , euclid - like survey specifications are used @xcite : we divided the redshift range @xmath25 $ ] in 5 bins of width @xmath26 and one of width @xmath27 ; a spectroscopic error @xmath28 , and a fraction of sky @xmath29 ; the bias @xmath3 in the fiducial is assumed to be unity .

Suppose that you have an abstract for a scientific paper: in this paper , the relation between skin friction and heat transfer along windward sides of blunt - nosed bodies in hypersonic flows is investigated . the self - similar boundary layer analysis is accepted to figure out the distribution of the ratio of skin friction to heat transfer coefficients along the wall . it is theoretically obtained that the ratio depends linearly on the local slope angle of the wall surface , and an explicit analogy expression is presented for circular cylinders , although the linear distribution is also found for other nose shapes and even in gas flows with chemical reactions . furthermore , based on the theoretical modelling of the second order shear and heat transfer terms in burnett equations , a modified analogy is derived in the near continuum regime by considering the rarefied gas effects . and a bridge function is also constructed to describe the nonlinear analogy in the transition flow regime . at last , the direct simulation monte carlo method is used to validate the theoretical results . the general analogy , beyond the classical reynolds analogy , is applicable to both flat plates and blunt - nosed bodies , in either continuous or rarefied hypersonic flows . + + + + + + + + + . And you have already written the first three sentences of the full article: [ cols="<,^ , < " , ] there have long been concerns on the connection between skin friction and wall heat - transfer rate ( or simply , heat transfer ) , as macroscopically the two quantities are related respectively to the normal gradient of velocity and temperature , and microscopically they are momentum and energy transports arising from molecular moves and collisions . the most famous result of this subject is the reynolds analogy in the flat plate boundary layer flow problem , where the skin friction and heat transfer were found proportional along the surface .. Please generate the next two sentences of the article

but such simple relationship does not exist for curved surfaces . for example , in flows past circular cylinders or spheres the heat transfer reaches its maximum at the stagnation point and diminishes monotonously downstream while the skin friction is zero at the stagnation point and varies non - monotonically downstream . with regard to the relation between skin friction and heat transfer ,

Suppose that you have an abstract for a scientific paper: we show , by means of numerical and analytical methods , that media with a repulsive nonlinearity which grows from the center to the periphery support a remarkable variety of previously unknown complex stationary and dynamical three - dimensional solitary - wave states . peanut - shaped modulation profiles give rise to vertically symmetric and antisymmetric vortex states , and novel stationary _ hybrid states _ , built of top and bottom vortices with opposite topological charges , as well as robust _ dynamical hybrids _ , which feature stable precession of a vortex on top of a zero - vorticity base . the analysis reveals stability regions for symmetric , antisymmetric , and hybrid states . in addition , bead - shaped modulation profiles give rise to the first example of exact analytical solutions for stable three - dimensional vortex solitons . the predicted states may be realized in media with a controllable cubic nonlinearity , such as bose - einstein condensates . . And you have already written the first three sentences of the full article: self - trapping of three - dimensional ( 3d ) confined modes ( solitons or , more properly , solitary waves ) in optics @xcite , bose - einstein condensates ( becs ) @xcite , ferromagnetic media @xcite , superconductors superconductor - knot , semiconductors @xcite , baryonic matter low - energy , and general field theory @xcite is a fundamental problem of nonlinear physics . an apparent condition is that an attractive , or self - focusing , nonlinearity is necessary for the creation of localized states ; however , the attractive cubic nonlinearity simultaneously gives rise to collapse @xcite of localized modes in higher - dimensional settings and , additionally , to strong azimuthal modulational instability of states with intrinsic vorticity @xcite , thus making the search for stable 3d fundamental and topological solitons in materials with the cubic ( kerr ) nonlinearity a challenging issue . various methods have been elaborated over the years , chiefly in the theoretical form , to remedy this situation and stabilize 3d solitary waves , fundamental and vortical ones alike . as outlined in detail in the reviews @xcite. Please generate the next two sentences of the article

( see also the more recent work @xcite ) , stabilization may be achieved by a higher - order quintic self - defocusing nonlinearity , provided that the underlying physical setting gives rise to such terms . another possibility is offered by periodic ( lattice ) potentials review1,dum , review2 . in particular , a 2d potential may be sufficient for the stabilization of 3d solitons , as well as for the stabilization against supercritical collapse @xcite .

Suppose that you have an abstract for a scientific paper: we perform a von neumann stability analysis on a common discretization of the einstein equations . the analysis is performed on two formulations of the einstein equations , namely , the standard adm formulation and the conformal - traceless ( ct ) formulation . the eigenvalues of the amplification matrix are computed for flat space as well as for a highly nonlinear plane wave exact solution . we find that for the flat space initial data , the condition for stability is simply @xmath0 . however , a von neumann analysis for highly nonlinear plane wave initial data shows that the standard adm formulation is unconditionally unstable , while the conformal - traceless ( ct ) formulation is stable for @xmath1 . . And you have already written the first three sentences of the full article: numerically solving the full 3d nonlinear einstein equations is , for several reasons , a daunting task . still , numerical relativity remains the best method for studying astrophysically interesting regions of the solution space of the einstein equations in sufficient detail and accuracy in order to be used to interpret measurements made by the up and coming gravitational wave detectors . even though numerical relativity is almost 35 years old , some of the same problems faced by researchers three decades ago are present today . aside from the computational complexity of implementing a numerical solver for the nonlinear einstein equations , there exist several unsolved problems , including the well - posedness of certain initial value formulations of the einstein equations and the proper choice of gauge .. Please generate the next two sentences of the article

not the least of these problems is numerical stability . a common thread in numerical relativity research over the past three decades is the observation of high frequency ( nyquist frequency ) noise growing and dominating the numerical solution .

Suppose that you have an abstract for a scientific paper: variations of eclipse arrival times have recently been detected in several post common envelope binaries consisting of a white dwarf and a main sequence companion star . the generally favoured explanation for these timing variations is the gravitational pull of one or more circumbinary substellar objects periodically moving the centre of mass of the host binary . using the new extreme - ao instrument sphere , we image the prototype eclipsing post - common envelope binary in search of the brown dwarf that is believed to be responsible for variations in its eclipse arrival times . we report that an unprecedented contrast of @xmath0 at a separation of 260mas was achieved , but resulted in a non - detection . this implies that there is no brown dwarf present in the system unless it is three magnitudes fainter than predicted by evolutionary track models , and provides damaging evidence against the circumbinary interpretation of eclipse timing variations . in the case of v471tau , a more consistent explanation is offered with the applegate mechanism , in which these variations are prescribed to changes in the quadrupole moment within the main - sequence star . . And you have already written the first three sentences of the full article: circumbinary substellar objects , although anticipated for a long time , have only recently been identified around main - sequence binary stars @xcite . long before this however , claims have been made for circumbinary substellar objects around close white dwarf - main sequence binaries . initially consisting of a main sequence binary with separations of order @xmath11 au @xcite , these systems are believed to have been through a spectacular phase of binary star evolution to explain their current close separation .. Please generate the next two sentences of the article

when the more massive star of the binary evolves off the main sequence , it fills its roche - lobe and generates dynamically unstable mass transfer onto the secondary star . as the time scale for dynamically unstable mass transfer is much shorter than the thermal time scale of the secondary , the latter can not adjust its structure fast enough to incorporate the overflowing mass . instead , a common envelope of material forms around both the secondary star and the core of the giant . drag forces between the envelope and the central binary then cause the envelope to be expelled at the expense of orbital energy and angular momentum of the binary ( e.g. * ? ? ?

Suppose that you have an abstract for a scientific paper: the classical observational cosmological tests ( hubble diagram , count of sources , etc . ) are considered for a homogeneous and isotropic model of the universe in the framework of the five - dimensional projective unified field theory in which gravitation is described by both space - time curvature and some hypothetical scalar field ( @xmath0-field ) . it is shown that the presence of the @xmath0-field can essentially affect conclusions obtained from the cosmological tests . the surface brightness - redshift relation can be used as a critical test for @xmath0-field effects . it seems reasonable to say that the available experimental data testify that the @xmath0-field decreases with time . it is concluded that the spatial curvature is positive or negative depending on whether the mass density is larger or smaller than some critical parameter which is smaller than the critical density and can even take negative values . it is shown that the increase in the number of the observational cosmological parameters as compared to the standard friedmann model can essentially facilitate coordination of the existing observational data . . And you have already written the first three sentences of the full article: it has been known that the cosmological tests @xcite are a convenient method of studying cosmological gravitational fields . the most important of them are : magnitude - redshift relation ( hubble diagram ) , count of sources , angular size - redshift relation , etc . these tests allow one to find the hubble constant @xmath1 and the deceleration parameter @xmath2 .. Please generate the next two sentences of the article

however recent estimates of these parameters , obtained from different tests in the framework of the standard friedmann model , are in rather poor mutual agreement without special additional assumptions ( see , e.g. , @xcite and references therein ) . the reasons for these difficulties can be both in unreliability of the observational data ( which is mainly connected with evolution and selection effects ) and in the restriction to the friedmann model based on the equations of general relativity ( gr ) . in this context

Suppose that you have an abstract for a scientific paper: we investigate a three - dimensional kinetically - constrained model that exhibits two types of phase transitions at different densities . at the jamming density @xmath0 there is a mixed - order phase transition in which a finite fraction of the particles become frozen , but the other particles may still diffuse throughout the system . at the caging density @xmath1 , the mobile particles are trapped in finite cages and no longer diffuse . the caging transition occurs due to a percolation transition of the unfrozen sites , and we numerically find that it is a continuous transition with the same critical exponents as random percolation . . And you have already written the first three sentences of the full article: kinetically - constrained models are widely used in the study of jamming- and glass - transitions in amorphous materials @xcite . these lattice - gas ( or spin-@xmath2 ising ) models are characterized by having some local restricting set of rules for particle movement ( or spin flip ) . in spin - facilitated models , the two possible states at each site represent active versus inactive regions , with the fraction of active sites increasing with increasing temperature .. Please generate the next two sentences of the article

the density of these active sites corresponds to the density of vacancies in lattice - gas models . in the fredrickson - andresen @xcite and kob - andersen @xcite models for example , the number of neighboring vacant ( active ) sites sets whether a site is _ blocked _ or not , and _ jamming _ of the system is often studied in terms of the fraction of _ frozen _ particles that will permanently remain blocked under the model s dynamics . in the thermodynamic limit these models jam only in the pathological limit of zero temperature or alternatively vanishing vacancy density @xcite , thus only spatial confinement may induce jamming at a nontrivial density in them @xcite . ) is unblocked if its ( ( w _ or

Suppose that you have an abstract for a scientific paper: we show that numerical quasi - one - dimensional renormalization group allows accurate study of weakly coupled chains with modest computational effort . we perform a systematic comparison with exact diagonalization results in two and three - leg spin ladders with a transverse hamiltonian that can involve frustration . due to the variational nature of the algorithm , the accuracy can be arbitrarily improved enlarging the basis of eigenstates of the density matrix defined in the transverse direction . we observe that the precision of the algorithm is directly correlated to the binding of the chains . we also show that the method performs especially well in frustrated systems . . And you have already written the first three sentences of the full article: it was recently shown @xcite that a general kato - bloch matrix expansion can be applied to weakly - coupled quantum chains . this algorithm was used to study weakly - coupled heisenberg chains @xcite . the dmrg was used as the method of solution for an isolated chain and then again for the solution of an effective 1d model which is obtained by projecting the problem to the basis of the tensor product of independent chain states . a good agreement with the stochastic series expansion ( sse ). Please generate the next two sentences of the article

quantum monte carlo ( qmc ) was found for transverse couplings @xmath0 not too large . then interchain diagonal exchange @xmath1 which frustrates the system was introduced .

Suppose that you have an abstract for a scientific paper: during the last decade , lattice - boltzmann ( @xmath0 ) simulations have been improved to become an efficient tool for determining the permeability of porous media samples . however , well known improvements of the original algorithm are often not implemented . these include for example multirelaxation time schemes or improved boundary conditions , as well as different possibilities to impose a pressure gradient . this paper shows that a significant difference of the calculated permeabilities can be found unless one uses a carefully selected setup . we present a detailed discussion of possible simulation setups and quantitative studies of the influence of simulation parameters . we illustrate our results by applying the algorithm to a fontainebleau sandstone and by comparing our benchmark studies to other numerical permeability measurements in the literature . . And you have already written the first three sentences of the full article: the accurate numerical simulation of fluid flow in porous media is important in many applications ranging from hydrocarbon production and groundwater flow to catalysis and the gas diffusion layers in fuel cells @xcite . examples include the behavior of liquid oil and gas in porous rock @xcite , permeation of liquid in fibrous sheets such as paper @xcite , determining flow in underground reservoirs and the propagation of chemical contaminants in the vadose zone @xcite , assessing the effectiveness of leaching processes @xcite and optimizing filtration and sedimentation operations @xcite . an important and experimentally determinable property of porous media is the permeability , which is highly sensitive to the underlying microstructure .. Please generate the next two sentences of the article

comparison of experimental data to numerically obtained permeabilities can improve the understanding of the influence of different microstructures and assist in the characterization of the material . before the 1990 s the computational power available was very limited restricting all simulations either to small length scales or low resolution of the microstructure .

Suppose that you have an abstract for a scientific paper: in this study , we explore a particular type hawking radiation which ends with zero temperature and entropy . the appropriate black holes for this purpose are the linear dilaton black holes . in addition to the black hole choice , a recent formalism in which the parikh - wilczek s tunneling formalism amalgamated with quantum corrections to all orders in @xmath0 is considered . the adjustment of the coefficients of the quantum corrections plays a crucial role on this particular hawking radiation . the obtained tunneling rate indicates that the radiation is not pure thermal anymore , and hence correlations of outgoing quanta are capable of carrying away information encoded within them . finally , we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation , entropy of the radiation becomes identical with the entropy of the black hole , which corresponds to `` no information loss '' . . And you have already written the first three sentences of the full article: hawking @xcite and @xcite showed in their seminal works that a black hole ( bh ) should slowly radiate away energy with its characteristic temperature and entropy . but the semi - classical picture of the hawking radiation has a thermal nature , which poses a fundamental physical problem . because , when the material entering the bh is a pure quantum state , the transformation of that state into the mixed state of hawking radiation would destroy information about the original quantum state . however , this violates quantum mechanical unitarity and presents a physical paradox so called the information loss paradox . for review of the topic and references on the bh information loss problem. Please generate the next two sentences of the article

the reader may refer to @xcite . there are various ideas about how the paradox could be solved . among them , may be the most elegant and comprehensible one is the parikh and wilczek ( pw ) s quantum tunneling formalism @xcite .

Suppose that you have an abstract for a scientific paper: we analyze some exact and approximate solutions to nonlinear equations for heat transfer models . we prove that recent results derived from a method based on lie algebras are either trivial or wrong . we test a simple analytical expression based on the hypervirial theorem and also discuss earlier perturbation results . . And you have already written the first three sentences of the full article: in a recent paper moitsheki et al@xcite argued that a method based on lie algebras is suitable for obtaining the solution to nonlinear ordinary differential equations that appear in simple models for heat transfer . they compared the analytical solutions with other results coming from perturbation approaches like homotopy perturbation method ( hpm ) and homotopy analysis method ( ham)@xcite . it is worth noticing that there is an unending controversy between the users of those fashionable perturbation approaches that arose some time ago@xcite . the purpose of this paper is to determine the usefulness of the results for the heat transfer systems provided by the lie algebraic method and those perturbation approaches . in sec .. Please generate the next two sentences of the article

[ sec : exact ] we analyze the exact solutions arising from lie algebras , in sec . [ sec : taylor ] we outline the application of the well known taylor series approach , in sec .

Suppose that you have an abstract for a scientific paper: the difference between the strange and antistrange quark distributions , @xmath0 , and the combination of light quark sea and strange quark sea , @xmath1 , are originated from non - perturbative processes , and can be calculated using non - perturbative models of the nucleon . we report calculations of @xmath2 and @xmath3 using the meson cloud model . combining our calculations of @xmath3 with relatively well known light antiquark distributions obtained from global analysis of available experimental data , we estimate the total strange sea distributions of the nucleon . # 1#2#3#4#1 , # 3 , * # 2 * : # 4 strange and antistrange quark distributions , nucleon meson cloud model 2 . And you have already written the first three sentences of the full article: the strange and antistrange quark distributions of the nucleon are of great interest . it has been known for some time that non - perturbative processes involving the meson cloud of the nucleon may break the symmetry between the strange and antistrange quark distributions . this asymmetry affects the extraction of @xmath4 from neutrino dis processes@xcite .. Please generate the next two sentences of the article

a precise understanding on the cross - secrion for @xmath5 production at the large hadron collider ( lhc ) depends on the strange sea distributions at small @xmath6 region . however , the strange sea distributions are not well determined compared with those for the light quark sea .

Suppose that you have an abstract for a scientific paper: using cluster perturbation theory we calculate green s functions , quasi - particle energies and topological invariants for interacting electrons on a 2-d honeycomb lattice , with intrinsic spin - orbit coupling and on - site e - e interaction . this allows to define the parameter range ( hubbard u vs spin - orbit coupling ) where the 2d system behaves as a trivial insulator or quantum spin hall insulator . this behavior is confirmed by the existence of gapless quasi - particle states in honeycomb ribbons . we have discussed the importance of the cluster symmetry and the effects of the lack of full translation symmetry typical of cpt and of most quantum cluster approaches . comments on the limits of applicability of the method are also provided . topological invariants are by now widely recognized as a powerful tool to characterize different phases of matter ; in particular they turn out to be useful in the classification of topological insulators . @xcite in the topological insulator phase , solids are characterized by gapped bulk bands but present gapless edge states that allow charge or spin conductivity on the boundaries . the presence of such gapless edge states is linked to the emergence of non - vanishing topological invariants via a bulk - boundary correspondence . @xcite this topological feature ensures the robustness of the edge states against disorder . @xcite a two - dimensional honeycomb lattice with spin - orbit coupling has been identified as a remarkable and paradigmatic example of topological insulator . this system is the prototype of the so - called quantum spin hall ( qsh ) system presenting a quantized spin - hall conductance at the boundaries . the topological nature of qsh insulators is identified by a time - reversal ( @xmath0 ) - topological invariant @xmath1 @xcite . in the same way as the thouless - kohmoto - nightingale - den nijs @xcite ( tknn ) topological invariant was defined for the integer quantum hall effect , the above @xmath1 invariant was.... And you have already written the first three sentences of the full article: in the search for an extension of topological invariants from the non - interacting to the interacting case , the green s function has proved to be the fundamental tool @xcite . as shown in refs . the dressed one - particle green s function at zero frequency contains all the topological information that is required to calculate topological invariants : the inverse of the green s function at zero frequency defines a fictitious noninteracting topological hamiltonian @xcite @xmath6 and its eigenvectors @xmath7 are the quantities to be used to compute the topological invariants for the interacting system . here @xmath8 , @xmath9 are band and spin indices respectively ( @xmath10 ) .. Please generate the next two sentences of the article

the latter is a good quantum number if as in the model we study below the spin orbit interaction only involves the @xmath11 component of the spin . hence , we can take the time - reversal operator to be @xmath12 where @xmath13 acts on the spin indices , @xmath14 denotes complex conjugation and @xmath15 is the identity for the sublattice indices .

Suppose that you have an abstract for a scientific paper: space- and time - resolved measurements of spin drift and diffusion are performed on a gaas - hosted two - dimensional electron gas . for spins where forward drift is compensated by backward diffusion , we find a precession frequency in absence of an external magnetic field . the frequency depends linearly on the drift velocity and is explained by the cubic dresselhaus spin - orbit interaction , for which drift leads to a spin precession angle twice that of spins that diffuse the same distance . drift and diffusion of charge carriers in semiconductor nanostructures are the foundation of information technology . the spin of the electron is being investigated as an additional or complementary degree of freedom that can enhance the functionality of electronic devices and circuits @xcite . in the presence of spin - orbit interaction ( soi ) , the spins of moving electrons precess about effective magnetic fields that depend on the electron momentum vector , @xmath0 @xcite . in a two - dimensional electron gas ( 2deg ) , this precession has been proposed as a gate - tunable switching mechanism @xcite . spin diffusion and spin drift have been studied using optical @xcite and electrical techniques @xcite . a local spin polarization expands diffusively into a spin mode with a spatial polarization pattern that is characteristic of the strength and symmetry of the soi @xcite . an additional drift induced by an electric field does not modify the spatial precession period in the case of linear soi @xcite . this is because spins that travel a certain distance and direction precess on average by the same angle , irrespective of how the travel is distributed between diffusion and drift . therefore , no spin precession occurs for quasi - stationary electrons , i.e. for electrons where drift is compensated by diffusion . . ( a ) measured spin polarization @xmath1 vs. @xmath2 for different @xmath3 at an electric field @xmath4 kv / m . the data is offset according to @xmath3 and normalized.... And you have already written the first three sentences of the full article: ( 4 ) of the main text , we give the result of @xmath124 for the special case that drift occurs along the @xmath2-direction ( @xmath65 ) and detection at @xmath66 ( @xmath67 ) . here , we provide the result for a general case : @xmath127 \\ - k_{\mathrm{di},x } -2 k_{\mathrm{dr},x } + \frac{2}{k_\mathrm{f}^2 } \left [ k_{\mathrm{di},x } k_{\mathrm{dr},y}^2 + 2 k_{\mathrm{di},y } k_{\mathrm{dr},y } k_{\mathrm{dr},x } + k_{\mathrm{dr},y}^2 k_{\mathrm{dr},x } - 3 k_{\mathrm{di},x } k_{\mathrm{dr},x}^2 - k_{\mathrm{dr},x}^3 \right ] \end{pmatrix } \ , .\ ] ] @xmath129 + 2 k_{\mathrm{dr},y } \left[1 + \left(\frac{k_{\mathrm{dr},y}}{k_\mathrm{f}}\right)^2 \right ] \\ k_{\mathrm{di},x } \left [ 1 - \left(\frac{2 k_{\mathrm{dr},y}}{k_\mathrm{f } } \right)^2 \right ] \end{pmatrix } \ , .\ ] ] for @xmath128 evm , @xmath136 evm and @xmath137 evm , respectively . in all cases , @xmath138 evm , @xmath139 evm and @xmath140 km / s ( violet dashed line ) . we find good agreement between the simulation and the model ( green solid lines ) for the entire parameter range .. Please generate the next two sentences of the article

[ si_fig1 ] ] in the main text , we discuss the validity of the model for cases away from the psh symmetry , i.e. , away from @xmath87 , by comparing the model with spin - precession maps obtained from numerical monte - carlo simulations . we state that , as long as drift occurs along @xmath2 , we obtain good agreement between simulation and model . in fig .

Suppose that you have an abstract for a scientific paper: we use the blanchfield - duval form to define complete invariants for the cobordism group @xmath0 of @xmath1-dimensional @xmath2-component boundary links ( for @xmath3 ) . the author solved the same problem in earlier work via seifert forms . although seifert forms are convenient in explicit computations , the blanchfield - duval form is more intrinsic and appears naturally in homology surgery theory . the free cover of the complement of a link is constructed by pasting together infinitely many copies of the complement of a @xmath2-component seifert surface . we prove that the algebraic analogue of this construction , a functor denoted @xmath4 , identifies the author s earlier invariants with those defined here . we show that @xmath4 is equivalent to a universal localization of categories and describe the structure of the modules sent to zero . taking coefficients in a semi - simple artinian ring , we deduce that the witt group of seifert forms is isomorphic to the witt group of blanchfield - duval forms . invariants of boundary link cobordism ii . + the blanchfield - duval form + desmond sheiham . And you have already written the first three sentences of the full article: this paper is the second in a series on cobordism ( = concordance ) groups of a natural class of high - dimensional links . chapter @xmath5 of the first work @xcite discusses background to the problem at greater length but we summarize here some of the key ideas . a knot is an embedding of spheres or topological manifolds according to taste , with the understanding that @xmath6 is permitted exotic structures if one selects the smooth category . ] @xmath7 .. Please generate the next two sentences of the article

the following are generalizations : * a @xmath2-component _ link _ is an embedding of @xmath2 disjoint spheres @xmath8 * a _ boundary link _ is a link whose components bound disjoint @xmath9-manifolds . the union of these @xmath9-manifolds is called a _

Suppose that you have an abstract for a scientific paper: we employ landau s theory of normal fermi liquids to study the quasiparticle interaction in nuclear matter in the vicinity of saturation density . realistic low - momentum nucleon - nucleon interactions evolved from the idaho n@xmath0lo chiral two - body potential are used as input potentials . we derive for the first time exact results for the central part of the quasiparticle interaction computed to second order in perturbation theory , from which we extract the @xmath1 and @xmath2 landau parameters as well as some relevant bulk equilibrium properties of nuclear matter . the accuracy of the intricate numerical calculations is tested with analytical results derived for scalar - isoscalar boson exchange and ( modified ) pion exchange at second order . the explicit dependence of the fermi liquid parameters on the low - momentum cutoff scale is studied , which provides important insight into the scale variation of phase - shift equivalent _ two - body _ potentials . this leads naturally to explore the role that three - nucleon forces must play in the effective interaction between two quasiparticles . . And you have already written the first three sentences of the full article: describing the properties of infinite nuclear matter has long been an important benchmark for realistic models of the nuclear force and the applied many - body methods . recent calculations @xcite have shown that the ( goldstone ) linked - diagram expansion ( up to at least second order ) can provide an adequate description of the zero - temperature equation of state when realistic two - nucleon and three - nucleon forces are employed . in the present work we study nuclear matter from the perspective of landau s fermi liquid theory @xcite , which is a framework for describing excitations of strongly - interacting normal fermi systems in terms of weakly - interacting quasiparticles .. Please generate the next two sentences of the article

although the complete description of the interacting many - body ground state lies beyond the scope of this theory , various bulk equilibrium and transport properties are accessible through the quasiparticle interaction . the interaction between two quasiparticles can be obtained microscopically within many - body perturbation theory by functionally differentiating the total energy density twice with respect to the quasiparticle distribution function .

Suppose that you have an abstract for a scientific paper: using hourly atmospheric surface pressure field from ecmwf ( european centre for medium - range weather forecasts ) and from ncep ( national centers for environmental prediction ) climate forecast system reanalysis ( cfsr ) models , we show that atmospheric pressure fluctuations excite the translational oscillation of the inner core , the so - called slichter mode , to the sub - nanogal level at the earth surface . the computation is performed using a normal - mode formalism for a spherical , self - gravitating anelastic prem - like earth model . we determine the statistical response in the form of power spectral densities of the degree - one spherical harmonic components of the observed pressure field . both hypotheses of inverted and non - inverted barometer for the ocean response to pressure forcing are considered . based on previously computed noise levels , we show that the surface excitation amplitude is below the limit of detection of the superconducting gravimeters , making the slichter mode detection a challenging instrumental task for the near future . slichter mode ; ecmwf atmospheric model ; ncep / cfsr atmospheric model ; superconducting gravimeters ; surface gravity ; normal mode . And you have already written the first three sentences of the full article: the search for the surface gravity effect of the free translational oscillations of the inner core , the so - called slichter modes @xcite , has been a subject of observational challenge , particularly since the development of worldwide data from superconducting gravimeters ( sgs ) of the global geodynamics project @xcite . indeed these relative gravimeters are the most suitable instruments to detect the small signals that would be expected from the slichter modes @xcite . a first claim by @xcite of a triplet of frequencies that he attributed to the slichter modes led to a controversy ( e.g. @xcite ) . this detection has been supported by @xcite and @xcite but has not been confirmed by other authors @xcite .. Please generate the next two sentences of the article

@xcite have shown it is necessary to consider dynamic love numbers to calculate the slichter mode eigenperiods . latest theoretical computation predicts a degenerate ( without rotation or ellipticity ) eigenperiod of 5.42 h @xcite for the seismological reference prem @xcite earth model . a more recent study by @xcite states that the period could be shorter because of the kinetics of phase transformations at the inner - core boundary ( icb ) . the interest raised by the slichter modes resides in its opportunity to constrain the density jump and the viscosity in the fluid outer core at the icb .

Suppose that you have an abstract for a scientific paper: the effect of a change of noise amplitudes in overdamped diffusive systems is linked to their unperturbed behavior by means of a nonequilibrium fluctuation - response relation . this formula holds also for systems with state - independent nontrivial diffusivity matrices , as we show with an application to an experiment of two trapped and hydrodynamically coupled colloids , one of which is subject to an external random forcing that mimics an effective temperature . the nonequilibrium susceptibility of the energy to a variation of this driving is an example of our formulation , which improves an earlier version , as it does not depend on the time - discretization of the stochastic dynamics . this scheme holds for generic systems with additive noise and can be easily implemented numerically , thanks to matrix operations . @xmath0 dipartimento di fisica e astronomia `` galileo galilei '' , universit di padova , via marzolo 8 , 35131 , padova , italy + @xmath1 laboratoire de physique de ecole normale suprieure de lyon ( cnrs umr5672 ) , 46 alle ditalie , 69364 lyon , france . + @xmath2 max planck institute for mathematics in the sciences , inselstr . 22 , 04103 leipzig , germany + @xmath3 institut fr theoretische physik , universitt leipzig , postfach 100 920 , d-04009 leipzig , germany + @xmath4 infn , sezione di padova , via marzolo 8 , 35131 , padova , italy + @xmath5 email : baiesi@pd.infn.it + _ keywords _ : nonequilibrium statistical mechanics ; fluctuation - response relations ; hydrodynamic interactions . + _ pacs _ : 05.40.-a , 05.70.ln . And you have already written the first three sentences of the full article: several phenomena are often modeled by a continuous stochastic dynamics in which a noise term randomizes the motion of each degree of freedom . these noises can have a nontrivial structure . for example , hydrodynamic interactions between diffusing particles , due to the concerted motion of the fluid molecules , are represented by a cross - correlation of noise terms in langevin equations , with amplitudes proportional to the bath temperature @xcite .. Please generate the next two sentences of the article

finding the response of the system to a variation of one of the noise amplitudes is a task that encounters some mathematical difficulty . while a variation of deterministic drifts in diffusion equations may be dealt with by established tools @xcite , such as the girsanov theorem @xcite and radon - nikodym derivatives @xcite , it is not straightforward to compare two dynamics driven by different noise amplitudes @xcite , due to the missing absolute continuity between the two path measures . this might have hampered the definition of a linear response theory to temperature variations or in general to noise - amplitude variations .

Suppose that you have an abstract for a scientific paper: we present a theoretical study of electromagnetic surface waves localized at an interface separating a conventional uniform medium and a semi - infinite 1-d photonic crystal made of alternate left - handed metamaterial and right - handed material which we refer to as left - handed photonic crystal . we find novel type of surface mode s structure , the so - called surface tamm states and demonstrate that the presence of metamaterial in the photonic crystal structure allows for a flexible control of the dispersion properties of surface states , and can support the tamm states with a backward energy flow and a vortex - like structure . tamm states ; photonic crystals ; metamaterials . And you have already written the first three sentences of the full article: the _ left - handed metamaterial _ ( lhm ) with negative permittivity and negative permeability has attracted much attention @xcite and triggered the debates on the application of the left - handed slab as so - called `` superlenses '' @xcite . over 30 years ago , veselago @xcite , first proposed that this peculiar medium possesses a negative refractive index , which has been demonstrated at microwave frequencies in recent experiment @xcite . in such media , there are many interesting properties such as the reversal of both doppler effect and chernekov radiation @xcite , amplification of evanescent waves @xcite , and unusual photon tuneling @xcite , negative giant goos - hanchen effect @xcite .. Please generate the next two sentences of the article

all these phenomena are rooted in the fact that the phase velocity of light wave in the lhm is opposite to the velocity of energy flow , that is , the poynting vector and wavevector are antiparallel so that the wavevector , the electric field , and the magnetic field form a left - handed ( lh ) system . interfaces between different physical media can support a special type of localized waves as _ surface waves _ or _ surface modes _ where the wave vector becomes complex causing the wave to exponentially decay away from the surface . aside from their intrinsic interest , surface electromagnetics waves

Suppose that you have an abstract for a scientific paper: we have performed a microscopic study of a straight quantized vortex line in three dimensions in condensed @xmath0he at zero temperature using the shadow path integral ground state method and the fixed - phase approximation . we have characterized the energy and the local density profile around the vortex axis in superfluid @xmath0he at several densities , ranging from below the equilibrium density up to the overpressurized regime . for the onsager - feynman ( of ) phase our results are exact and represent a benchmark for other theories . the inclusion of backflow correlations in the phase improves the description of the vortex with respect to the of phase by a large reduction of the core energy of the topological excitation . at all densities the phase with backflow induces a partial filling of the vortex core and this filling slightly increases with density . the core size slightly decreases for increasing density and the density profile has well defined density dependent oscillations whose wave vector is closer to the wave vector of the main peak in the static density response function rather than to the roton wave vector . our results can be applied to vortex rings of large radius @xmath1 and we find good agreement with the experimental value of the energy as function of @xmath1 without any free parameter . we have studied also @xmath0he above the melting density in the solid phase using the same functional form for the phase as in the liquid . we found that off - diagonal properties of the solid are not qualitatively affected by the velocity field induced by the vortex phase , both with and without backflow correlations . therefore we find evidence that a perfect @xmath0he crystal is not a marginally stable quantum solid in which rotation would be able to induce off diagonal long range coherence . . And you have already written the first three sentences of the full article: topological excitations represent a class of excitations of fundamental interest in many ordered phases in condensed matter like bose / bcs condensed quantum fluids , superconductors , crystals or nematic liquid crystals . starting from the works by onsager@xcite and by feynman@xcite a widely studied example of a topological excitation is a vortex line in a bose superfluid , in particular in superfluid @xmath0he . vortices play a fundamental role in many superfluid phenomena , for instance the behavior of a superfluid under rotation or the value of the critical velocity for the onset of dissipation in many cases are determined by vortex nucleation . addressing specifically superfluid @xmath0he almost all the studies of vortices. Please generate the next two sentences of the article

are based on simplified models in which vorticity turns out to be localized along mathematical lines , more precisely the phase of the wave function ( wf ) is assumed to be additive in the phase of each particle , the so called onsager - feynman ( of ) form . within this approximation the vorticity field has a singularity along a line , the vortex core , where the density vanishes and the velocity diverges .

Suppose that you have an abstract for a scientific paper: wireless powered communication network ( wpcn ) is a new networking paradigm where the battery of wireless communication devices can be remotely replenished by means of microwave wireless power transfer ( wpt ) technology . wpcn eliminates the need of frequent manual battery replacement / recharging , and thus significantly improves the performance over conventional battery - powered communication networks in many aspects , such as higher throughput , longer device lifetime , and lower network operating cost . however , the design and future application of wpcn is essentially challenged by the low wpt efficiency over long distance and the complex nature of joint wireless information and power transfer within the same network . in this article , we provide an overview of the key networking structures and performance enhancing techniques to build an efficient wpcn . besides , we point out new and challenging future research directions for wpcn . . And you have already written the first three sentences of the full article: the recent advance of microwave wireless power transfer ( wpt ) technology enables to build wireless powered communication networks ( wpcns ) , where wireless devices ( wds ) are powered over the air by dedicated wireless power transmitters for communications @xcite . compared to conventional battery - powered networks , wpcn eliminates the need of manual battery replacement / recharging , which can effectively reduce the operational cost and enhance communication performance . besides , wpcn has full control over its power transfer , where the transmit power , waveforms , and occupied time / frequency dimensions , etc . , are all tunable for providing stable energy supply under different physical conditions and service requirements .. Please generate the next two sentences of the article

this is in vivid contrast to _ energy harvesting _ ( eh ) based approaches , where wds opportunistically harness renewable energy in environment not dedicated to power the wds , e.g. , solar power and ambient radio frequency ( rf ) transmission . because the availability and strength of renewable energy sources are mostly random and time varying , stable and on - demand energy supply to wds is often not achievable with eh - based methods . these evident advantages of wpt over conventional energy supply methods make wpcn a promising new paradigm to the design and implementation of future wireless communication systems with stable and self - sustainable power supplies .

Suppose that you have an abstract for a scientific paper: two theoretical descriptions of exclusive diffractive jets and higgs production at the lhc were implemented into the fpmc generator : the khoze , martin , ryskin model and the cudell , hernndez , ivanov , dechambre exclusive model . we then study the uncertainties . we compare their predictions to the cdf measurement and discuss the possibility of constraining the exclusive higgs production at the lhc with early measurements of exclusive jets . we show that the present theoretical uncertainties can be reduced with such data by a factor of 5 . . And you have already written the first three sentences of the full article: the higgs boson is the last particle of the standard model remaining to be confirmed experimentally . inclusive searches in decay channels such as @xmath0 , @xmath1 , @xmath2 , @xmath3 and associated production have been performed at the tevatron and are being started at the lhc . however the search for the higgs boson at low mass is complicated due to the huge background coming from qcd jet events . especially the @xmath4 channel , dominant for @xmath5 , is very difficult at the tevatron and literally impossible at the lhc .. Please generate the next two sentences of the article

thus other possibilities have been investigated , in particular using the exclusive diffractive production @xcite . in such processes both incoming hadrons , @xmath6 at the tevatron and @xmath7 at the lhc , remain intact after the interaction and the higgs decays in the central region .

Suppose that you have an abstract for a scientific paper: an overview of the basic results on macdonald - koornwinder polynomials and double affine hecke algebras is given . we develop the theory in such a way that it naturally encompasses all known cases as well as a new rank two case . among the basic properties of the macdonald - koornwinder polynomials we treat are the quadratic norm formulas , duality and the evaluation formulas . this text is a provisional version of a chapter on macdonald - koornwinder polynomials for volume 5 of the askey - bateman project , entitled `` multivariable special functions '' . . And you have already written the first three sentences of the full article: this text is a provisional version of a chapter on macdonald - koornwinder polynomials for volume 5 of the askey - bateman project , entitled `` multivariable special functions '' . the aim is to introduce nonsymmetric and symmetric macdonald - koornwinder polynomials and to present their basic properties : ( bi-)orthogonality , norm formulas , q - difference(-reflection ) equations , duality and evaluation formulas . symmetric @xmath0 type macdonald polynomials were introduced by macdonald @xcite as a two - parameter family of orthogonal multivariate polynomials interpolating between the jack polynomials and the hall - littlewood polynomials .. Please generate the next two sentences of the article

root system generalizations were subsequently defined by macdonald in @xcite . they were labelled by so called admissible pairs of root systems . recasting these data in terms of affine root systems ( cf .

Suppose that you have an abstract for a scientific paper: we investigate the phase diagram of qcd at small chemical potentials , , when chiral and flavour symmetry breaking involves the pairing of a quark and an antiquark . the phase diagram of two - flavour qcd at small chemical potentials involves chiral symmetry restoration and charged pion condensation . we extend previous studies of the topology of the phase diagram , in sections with high degree of symmetry , to the physical case of fully broken flavour symmetry , using generic thermodynamic arguments . we argue that the extension is unique and present the result . in three flavour qcd the phase diagram for chiral symmetry restoration is less well constrained . however , we argue that present lattice data allows just two different phase diagrams , which we discuss . . And you have already written the first three sentences of the full article: more than thirty years after the first discussions about a phase transition in qcd @xcite , only small portions of the phase diagram have been explored . although the complete phase diagram of qcd is of high dimensionality , experiments can at best explore a three dimensional section of the full phase diagram . further , collisions of heavy - ions have only a single control parameter , the cm energy , @xmath0 . as a result. Please generate the next two sentences of the article

they explore a single line in this three - dimensional phase diagram . by varying the nuclei being collided , one could , perhaps , extend the search to a small patch around the line .

Suppose that you have an abstract for a scientific paper: this paper is concerned with two rather basic phenomena : the incoherent fluorescence spectrum of an atom driven by an intense laser field and the coupling of the atom to the ( empty ) modes of the radiation field . the sum of the many - photon processes gives rise to the inelastic part of the atomic fluorescence , which , for a two - level system , has a well - known characteristic three - peak structure known as the mollow spectrum . from a theoretical point of view , the mollow spectrum finds a natural interpretation in terms of transitions among laser - dressed states which are the energy eigenstates of a second - quantized two - level system strongly coupled to a driving laser field . as recently shown , the quasi - energies of the _ laser - dressed _ states receive radiative corrections which are nontrivially different from the results which one would expect from an investigation of the coupling of the _ bare _ states to the vacuum modes . in this article , we briefly review the basic elements required for the analysis of the dynamic radiative corrections , and we generalize the treatment of the radiative corrections to the incoherent part of the steady - state fluorescence to a three - level system consisting of @xmath0 , @xmath1 and @xmath2 states . . And you have already written the first three sentences of the full article: the theory of the interactions of atoms with light began in the 1920s and 1930s with the description of a number of basic processes ; one of these is the kramers heisenberg formula @xcite which describes a process in which an electron absorbs and emits one photon . the corresponding feynman diagram is shown in fig . 1 _ ( a)_. this scattering process is elastic , the electron radiates at exactly the driving frequency , a point which has been stressed a long time ago @xcite . if more than one photon is absorbed or emitted , then the energy conservation applied only to the sum of the frequencies of the absorbed and emitted photons [ see fig . 1 _ ( b ) _ ] .. Please generate the next two sentences of the article

the frequencies of the atomic fluorescence photons ( of the scattered radiation ) are not necessarily equal to the laser frequency @xmath3 . from the point of view of the @xmath4-matrix formalism , 1 _ ( a ) _ and _ ( b ) _ correspond to the forward scattering of an electron in a ( weak ) laser field .

Suppose that you have an abstract for a scientific paper: we deal with the problem of the final sign of the neutrino asymmetry generated by active - sterile neutrino oscillations in the early universe solving the full momentum dependent quantum kinetic equations . we study the parameter region @xmath0 values the sign of the neutrino asymmetry is fixed and does not oscillate . for values of mixing parameters in the region @xmath1 , the neutrino asymmetry appears to undergo rapid oscillations during the period where the exponential growth occurs . our numerical results indicate that the oscillations are able to change the neutrino asymmetry sign . the sensitivity of the solutions and in particular of the final sign of lepton number to small changes in the initial conditions depends whether the number of oscillations is high enough . it is however not possible to conclude whether this effect is induced by the presence of a numerical error or is an intrinsic feature . as the amplitude of the statistical fluctuations is much lower than the numerical error , our numerical analysis can not demonstrate the possibility of a chaotical generation of lepton domains . in any case this possibility is confined to a special region in the space of mixing parameters and it can not spoil the compatibility of the @xmath2 solution to the neutrino atmospheric data obtained assuming a small mixing of the @xmath3 with an @xmath4 neutrino . _ @xmath5 dipartimento di fisica , universit di roma la sapienza " and + i.n.f.n sezione di roma 1 + p.le aldo moro , 2 , i00185 roma , italy + ( dibari@roma1.infn.it ) + @xmath6 school of physics + research centre for high energy physics + the university of melbourne + parkville 3052 australia + ( foot@physics.unimelb.edu.au ) _ . And you have already written the first three sentences of the full article: if light sterile neutrinos exist , then this will lead to important implications for early universe cosmology . this is because ordinary - sterile neutrino oscillations generate large neutrino asymmetries for the large range of parameters , @xmath7@xcite . this is a generic feature of ordinary - sterile neutrino oscillations for this parameter range . for @xmath8 ,. Please generate the next two sentences of the article

the evolution of neutrino asymmetry is qualitatively quite different as collisions are so infrequent and a large neutrino asymmetry can not be generated@xcite . interestingly , some people do not currently accept that large neutrino asymmetry is generated in the early universe@xcite .

Suppose that you have an abstract for a scientific paper: proton temperature anisotropies between the directions parallel and perpendicular to the mean magnetic field are usually observed in the solar wind plasma . here , we employ a high - resolution hybrid particle - in - cell simulation in order to investigate the relation between spatial properties of the proton temperature and the peaks in the current density and in the flow vorticity . our results indicate that , although regions where the proton temperature is enhanced and temperature anisotropies are larger correspond approximately to regions where many thin current sheets form , no firm quantitative evidence supports the idea of a direct causality between the two phenomena . on the other hand , quite a clear correlation between the behavior of the proton temperature and the out - of - plane vorticity is obtained . . And you have already written the first three sentences of the full article: the solar wind is a highly turbulent plasma . this idea is supported by the power - law behavior of its observed energy spectra , which span nearly four decades in frequency , from large to small kinetic scales ( e.g. , @xcite ) . among other things , in situ measurements also reveal the presence of an ubiquitous proton temperature anisotropy between the direction parallel and perpendicular to the mean magnetic field @xcite . vlasov - hybrid simulations suggest that such temperature anisotropy and non - maxwellian kinetic effects are mostly found around peaks of the current density @xcite .. Please generate the next two sentences of the article

recently , high - resolution two - dimensional ( 2d ) hybrid particle - in - cell simulations have proved to be a reliable , state - of - the - art tool to investigate the properties of kinetic plasma turbulence , provided that a sufficiently large number of particles - per - cell is employed , especially when trying to quantitatively estimate the perpendicular proton temperature . in particular , the direct numerical simulations shown in @xcite have been able to recover simultaneously several features observed in the solar wind spectra , e.g. : i ) a power - law behavior for the magnetic , kinetic and residual energy spectra with different spectral indices ( e.g. , @xcite ) , ii ) a magnetic spectrum with a smooth break at proton scales and a power - law scaling in the sub - proton range with a spectral index of @xmath0 ( e.g. , @xcite ) , iii ) an increase in magnetic compressibility at small scales ( e.g. , @xcite ) , iv ) a strong coupling between density and magnetic fluctuations in the kinetic range ( e.g. , @xcite ) . in the present paper , we show new complementary results coming from the 2d hybrid particle - in - cell simulations already presented in @xcite . in particular , we will focus our attention on the correlations between the peaks in the out - of - plane vorticity and the proton temperature enhancement and anisotropy . the numerical results discussed here were obtained by means of the hybrid particle - in - cell code camelia , which treats electrons as a massless , charge neutralizing , isothermal fluid , whereas ions as particles .

Suppose that you have an abstract for a scientific paper: this paper proves best known guarantees for exact reconstruction of a sparse signal @xmath0 from few non - adaptive universal linear measurements . we consider fourier measurements ( random sample of frequencies of @xmath0 ) and random gaussian measurements . the method for reconstruction that has recently gained momentum in the sparse approximation theory is to relax this highly non - convex problem to a convex problem , and then solve it as a linear program . what are best guarantees for the reconstruction problem to be equivalent to its convex relaxation is an open question . recent work shows that the number of measurements @xmath1 needed to exactly reconstruct any @xmath2-sparse signal @xmath0 of length @xmath3 from its linear measurements with convex relaxation is usually @xmath4 . however , known guarantees involve huge constants , in spite of very good performance of the algorithms in practice . in attempt to reconcile theory with practice , we prove the first guarantees for universal measurements ( i.e. which work for all sparse functions ) with reasonable constants . for gaussian measurements , @xmath5 $ ] , which is optimal up to constants . for fourier measurements , we prove the best known bound @xmath6 , which is optimal within the @xmath7 and @xmath8 factors . our arguments are based on the technique of geometric functional analysis and probability in banach spaces . . And you have already written the first three sentences of the full article: during the last two years , the sparse approximation theory benefited from a rapid development of methods based on the linear programming . the idea was to relax a sparse recovery problem to a convex optimization problem . the convex problem can be further be rendered as a linear program , and analyzed with all available methods of linear programming .. Please generate the next two sentences of the article

convex relaxation of sparse recovery problems can be traced back in its rudimentary form to mid - seventies ; references to its early history can be found in @xcite . with the development of fast methods of linear programming in the eighties , the idea of convex relaxation became truly promising .

Suppose that you have an abstract for a scientific paper: identifying intersections among a set of @xmath0-dimensional rectangular regions ( @xmath0-rectangles ) is a common problem in many simulation and modeling applications . since algorithms for computing intersections over a large number of regions can be computationally demanding , an obvious solution is to take advantage of the multiprocessing capabilities of modern multicore processors . unfortunately , many solutions employed for the data distribution management service of the high level architecture are either inefficient , or can only partially be parallelized . in this paper we propose the interval tree matching ( itm ) algorithm for computing intersections among @xmath0-rectangles . itm is based on a simple interval tree data structure , and exhibits an embarrassingly parallel structure . we implement the itm algorithm , and compare its sequential performance with two widely used solutions ( brute force and sort - based matching ) . we also analyze the scalability of itm on shared - memory multicore processors . the results show that the sequential implementation of itm is competitive with sort - based matching ; moreover , the parallel implementation provides good speedup on multicore processors . data distribution management ; high level architecture ; parallel algorithms ; interval tree . And you have already written the first three sentences of the full article: the specification @xcite defines several services to forward events generated on _ update _ regions to a set of _ subscription _ regions . for example , consider a simulation of vehicles moving on a two - dimensional terrain . each vehicle may be interested in events happening inside its area of interest ( e.g. , its field of view ) that might be approximated with a rectangular region centered at the vehicle position .. Please generate the next two sentences of the article

this kind of problem also arises in the context of massively multiplayer online games , where the game engine must send updates only to players that might be affected by game events , in order to reduce computation cost and network traffic . in this paper we assume that a region corresponds to a single _ extent _ in terminology ) , that is , a @xmath0-dimensional rectangle ( @xmath0-rectangle ) in a @xmath0-dimensional routing space .

Suppose that you have an abstract for a scientific paper: we show that density spikes begin to form from dark matter particles around primordial black holes immediately after their formation at the radiation - dominated cosmological stage . this follows from the fact that in the thermal velocity distribution of particles there are particles with low velocities that remain in finite orbits around black holes and are not involved in the cosmological expansion . the accumulation of such particles near black holes gives rise to density spikes . these spikes are considerably denser than those that are formed later by the mechanism of secondary accretion . the density spikes must be bright gamma - ray sources . comparison of the calculated signal from particle annihilation with the fermi - lat data constrains the present - day cosmological density parameter for primordial black holes with masses @xmath0 from above by values from @xmath1 to @xmath2 , depending on @xmath3 . these constraints are several orders of magnitude more stringent than other known constraints . . And you have already written the first three sentences of the full article: primordial black holes ( pbhs ) , the possibility of whose formation was predicted in @xcite and @xcite , can give valuable information about processes in the early universe @xcite , in particular , about the shape of the perturbation spectrum on small scales @xcite . the quantum evaporation of low - mass pbhs is important from the viewpoint of investigating fundamental processes at high energies @xcite and can have significance for the theory of primordial nucleosynthesis and gamma - ray astronomy . in addition , pbhs can offer new possibilities for the formation of quasars at high @xmath4 @xcite and for baryonic objects with chemical peculiarities@xcite .. Please generate the next two sentences of the article

being captured by neutron stars , pbhs can affect their evolution , which gives a constraint on the number of pbhs @xcite . in this paper , we will discuss only the pbhs that are formed during the collapses of adiabatic density perturbations , when a mixture of relativistic particles collapses into a pbh at the instant the perturbation crosses the cosmological horizon @xcite .

Suppose that you have an abstract for a scientific paper: magnetic reconnection in laboratory , space and astrophysical plasmas is often invoked to explain explosive energy release and particle acceleration . however , the timescales involved in classical models within the macroscopic mhd regime are far too slow to match the observations . here we revisit the tearing instability by performing visco - resistive two - dimensional numerical simulations of the evolution of thin current sheets , for a variety of initial configurations and of values of the lunquist number @xmath0 , up to @xmath1 . results confirm that when the critical aspect ratio of @xmath2 is reached in the reconnecting current sheets , the instability proceeds on ideal ( alfvnic ) macroscopic timescales , as required to explain observations . moreover , the same scaling is seen to apply also to the local , secondary reconnection events triggered during the nonlinear phase of the tearing instability , thus accelerating the cascading process to increasingly smaller spatial and temporal scales . the process appears to be robust , as the predicted scaling is measured both in inviscid simulations and when using a prandtl number @xmath3 in the viscous regime . . And you have already written the first three sentences of the full article: most of the explosive events observed in the diverse astrophysical environments require the sudden release of the energy contained in magnetically dominated plasmas . fast reconnection provides the mechanism by which the magnetic energy is channeled into heat and particle acceleration with timescales comparable to the ideal timescale @xmath4 ( here @xmath5 is the characteristic length - scale of the magnetic structure and @xmath6 the alfvn speed ) and much shorter than diffusion timescale @xmath7 ( @xmath8 being the magnetic diffusivity ) . sweet parker ( sp ) models @xcite and the linear tearing instability of a current sheet ( cs ) @xcite based on the resistive magnetohyrodymanics ( mhd ) regime predict reconnection timescales which are too slow to explain bursty phenomena such as solar flares , magnetic substorms , and sawtooth crashes in tokamak @xcite .. Please generate the next two sentences of the article

indeed the reconnection rate in both models is very low ( proportional to @xmath9 where @xmath10 is typically @xmath11 in laboratory and astrophysical plasma ) unless non - mhd effects are taken into account @xcite . it has been recently realized that even in a magnetofluid approach , provided that @xmath12 , the tearing mode can become very fast . in particular sp

Suppose that you have an abstract for a scientific paper: multiscale technicolor models predict the existence of high mass resonances at hadron colliders . although the quark fusion process of production dominates , vector boson fusion offers the advantage of allowing forward jet tagging for background suppression . we calculate here the cross section and differential distributions for @xmath0 production in the vector boson fusion channel at the lhc . @xmath0 production via @xmath1 @xmath2 fusion at hadronic colliders s.r . slabospitsky + _ institute for high energy physics , + protvino , moscow region , 142284 russia _ + ` slabospitsky@mx.ihep.su ` + g. azuelos + _ universit de montreal , canada _ + ` azuelos@lps.umontreal.ca ` + . And you have already written the first three sentences of the full article: in the search for the origin of electroweak symmetry breaking , strong coupling models are an alternative to the standard model higgs mechanism , or for weakly coupled theories based on supersymmetry . although classical technicolor@xcite suffers from major shortcomings , viable multiscale models have been developed @xcite which allow for fermion mass generation and for the absence of weak neutral currents . these models , which are not necessarily excluded by precision measurements of electroweak parameters at lep and slc @xcite , not only provide the technipions which serve as the longitudinal components of the gauge bosons , but also predict the existence of technipions ( @xmath3 ) as mass eigenstates , as well as technirhos ( @xmath0 ) , and other techniparticles . the feasibility of observing such resonances produced in @xmath4 fusion , in atlas has been reported in @xcite .. Please generate the next two sentences of the article

the analysis was based on a pythia @xcite implementation of the multiscale model of eichten , lane and womersley @xcite , and took into account detector effects by using a fast simulation of the atlas detector . in particular , one of the channels analyzed was @xmath5 production with subsequent decay into @xmath6 . assuming a quark fusion process , the authors @xcite of the model have calculated the relevant matrix elements .

Suppose that you have an abstract for a scientific paper: we discuss the universal nature of relaxation in isolated many - body quantum systems subjected to global and strong periodic driving . our rigorous floquet analysis shows that the energy of the system remains almost constant up to an exponentially long time in frequency for arbitrary initial states and that an effective hamiltonian obtained by a truncation of the floquet - magnus expansion is a quasi - conserved quantity in a long timescale . these two general properties lead to intriguing classification on the initial stage of relaxation , one of which is similar to the prethermalization phenomenon in nearly - integrable systems . _ introduction. _ in periodically driven many - body quantum systems , excited states as well as the ground state participate in the dynamics , and nontrivial macroscopic phenomena can appear . recent years have witnessed remarkable experimental developments , such as the discoveries of the higgs mode in the oscillating order parameter of the superconducting material under a terahertz laser @xcite , and the floquet topological states in the periodically driven cold atom @xcite . periodic driving in isolated quantum systems sometimes generates unexpected dynamical phenomena even if the instantaneous hamiltonian at each time step is simple . to name only a few , dynamical localization @xcite , coherent destruction of tunneling @xcite , dynamical freezing @xcite , and dynamical phase transitions @xcite are remarkable far - from - equilibrium phenomena that can not be captured within linear - response analysis . on the other hand , as recently discussed in the context of _ thermalization _ , careful consideration is necessary on the true steady state in driven many - body systems @xcite . thermalization in isolated quantum systems has become one of critical subjects in modern physics @xcite . the first study was made by von neumann early in 1929 @xcite , and now we are on the new stage by incorporating many concepts including quantum entanglement .... And you have already written the first three sentences of the full article: we consider the same model that we discussed in the main text . namely we take a toy model where the dynamics is driven by @xmath43 for the first half period and @xmath44 for the second half period . the time - evolution operator for the single period @xmath93 is given by @xmath94 we show the time - evolution of @xmath95 for several system sizes and periods in fig . [ suppl1 ] . the initial state is chosen as the all spin - down state .. Please generate the next two sentences of the article

each graph of fig . [ suppl1 ] shows that @xmath95 remains finite when the system size is small , while it eventually tends to zero when the system size is large .

Suppose that you have an abstract for a scientific paper: the physics of compact objects is one of the very actively developing branches of theoretical investigations , since the careful analysis of different models for the internal structure of these objects , their evolutionary characteristics and the comparison with modern observational data give access to discriminate among various speculations about the state of matter under extreme conditions . the lecture provides an overview to the problem of neutron star cooling evolution . we discuss the scheme and necessary inputs for neutron star cooling simulations from the background of a microscopic modeling in order to present the surface temperature - age characteristics of hybrid neutron stars including the determination of main regulators of the cooling process , the question of neutrino production and diffusion . . And you have already written the first three sentences of the full article: the interiors of compact stars are considered as systems where high - density phases of strongly interacting matter do occur in nature , see shapiro and teukolsky @xcite , glendenning @xcite and weber @xcite for textbooks . the consequences of different phase transition scenarios for the cooling behaviour of compact stars have been reviewed recently in comparison with existing x - ray data @xcite . the einstein observatory was the first that started the experimental study of surface temperatures of isolated neutron stars ( ns ) .. Please generate the next two sentences of the article

upper limits for some sources have been found . then rosat offered first detections of surface temperatures .

Suppose that you have an abstract for a scientific paper: we consider the problem of deriving the no - signaling condition from the assumption that , as seen from a complexity theoretic perspective , the universe is not an exponential place . a fact that disallows such a derivation is the existence of _ polynomial superluminal _ gates , hypothetical primitive operations that enable superluminal signaling but not the efficient solution of intractable problems . it therefore follows , if this assumption is a basic principle of physics , either that it must be supplemented with additional assumptions to prohibit such gates , or , improbably , that no - signaling is not a universal condition . yet , a gate of this kind is possibly implicit , though not recognized as such , in a decade - old quantum optical experiment involving position - momentum entangled photons . here we describe a feasible modified version of the experiment that appears to explicitly demonstrate the action of this gate . some obvious counter - claims are shown to be invalid . we believe that the unexpected possibility of polynomial superluminal operations arises because some practically measured quantum optical quantities are not describable as standard quantum mechanical observables . . And you have already written the first three sentences of the full article: in a multipartite quantum system , any completely positive ( cp ) map applied locally to one part does not affect the reduced density operator of the remaining part . this fundamental no - go result , called the `` no - signalling theorem '' implies that quantum entanglement @xcite does not enable nonlocal ( `` superluminal '' ) signaling @xcite under standard operations , and is thus consistent with relativity , inspite of the counterintuitive , stronger - than - classical correlations @xcite that entanglement enables . for simple systems , no - signaling follows from non - contextuality , the property that the probability assigned to projector @xmath0 , given by the born rule , tr@xmath1 , where @xmath2 is the density operator , does not depend on how the orthonormal basis set is completed @xcite .. Please generate the next two sentences of the article

no - signaling has also been treated as a basic postulate to derive quantum theory @xcite . it is of interest to consider the question of whether / how computation theory , in particular intractability and uncomputability , matter to the foundations of ( quantum ) physics .

Suppose that you have an abstract for a scientific paper: in this paper , we investigate the perturbations in matter bounce induced from lee - wick lagrangian with the involvement of non - minimal coupling to the einstein gravity . we find that this extra non - minimal coupling term can cause a red - tilt on the primordial metric perturbation at extremely large scales . it can also lead to large enhancement of reheating of the normal field particles compared to the usual minimal coupling models . . And you have already written the first three sentences of the full article: non - singular bouncing cosmology @xcite has become one of the important alternative scenarios of inflation @xcite as a description of the early universe . in terms of a bounce scenario , the universe travels from a contracting phase to an expanding phase through a non - vanishing minimal size , avoiding the singularity problem which plagues the standard big bang theory @xcite or inflationary theory @xcite . moreover , a bounce can occur much below the planck scale , eliminating the transplanckian " problem of which the wavelength of the fluctuation mode we see today will be even smaller than planck scale and thus in the zone of ignorance " where high energy effects are robust and einstein equations might be invalid @xcite . in bounce models ,. Please generate the next two sentences of the article

fluctuations were generated in contracting phase and transferred into expanding phase through bouncing point , which can give rise to a scale invariant power spectrum as expected by the current observational data @xcite . in order to connect the perturbations in contracting phase and expanding phase at the crossing point , the joint condition of hwang - vishniac @xcite ( deruelle - mukhanov @xcite ) can be applied . besides , bouncing scenario can also be originated from non - relativistic gravity theories @xcite and give rise to gravitational waves with running signature and large non - gaussianities @xcite . in the previous studies , a kind of matter bounce " has been proposed where before and after the bounce , the universe could behave as non - relativistic matter .

Suppose that you have an abstract for a scientific paper: we analyse the diagonal quotient for the product of certain artin schreier curves . the smooth models are almost always surfaces of general type , with chern slopes tending asymptotically to 1 . the calculation of numerical invariants relies on a close examination of the relevant wild quotient singularity in characteristic @xmath0 . it turns out that the canonical model has @xmath1 rational double points of type @xmath2 , and embeds as a divisor of degree @xmath3 in @xmath4 , which is in some sense reminiscent of the classical kummer quartic . . And you have already written the first three sentences of the full article: it is a classical fact in complex geometry that the singular kummer surface @xmath5 attached to an abelian surface @xmath6 has sixteen rational double points , and an irreducible principal polarization embeds it as a quartic surface in @xmath4 , compare hudson s classical monography @xcite , or for a modern account @xcite . our starting point was an analogous computation in characteristic @xmath7 for the diagonal action of the additive group @xmath8 on the selfproduct @xmath9 , where @xmath10 is the supersingular elliptic curve , viewed as an artin schreier covering .. Please generate the next two sentences of the article

it turns out that this is a special case of a rather general construction , which works for all primes @xmath0 , in fact for all prime powers @xmath11 . it starts with certain _ artin schreier curves _ and leads , with a few exceptions for small prime powers , to _ surfaces of general type_. the goal of this paper is to describe the geometry of these surfaces , and we obtain a fairly complete description .

Suppose that you have an abstract for a scientific paper: it is known that if a classical link group is a free abelian group , then its rank is at most two , and a @xmath0-component 2-link group for @xmath1 is not a free abelian group . in this paper we give examples of surface links whose link groups are free abelian groups of rank three or four . moreover we show that the examples of rank three are infinitely many and one of them has the triple point number four.[multiblock footnote omitted ] . And you have already written the first three sentences of the full article: closed 1-manifolds embedded locally flatly in the euclidean 3-space @xmath2 are called _ classical links _ , and closed 2-manifolds embedded locally flatly in the euclidean 4-space @xmath3 are called _ surface links_. a surface link whose each component is of genus zero ( resp . one ) is called a _ @xmath4-link _ ( resp . _ @xmath5-link _ ) . two classical links ( resp .. Please generate the next two sentences of the article

surface links ) are _ equivalent _ if one is carried to the other by an ambient isotopy of @xmath2 ( resp . @xmath3 ) .

Suppose that you have an abstract for a scientific paper: in this article we try to answer the question whether the radar detection technique can be used for the detection of high - energy - neutrino induced particle cascades in ice . a high - energy neutrino interacting in ice will induce a particle cascade , also referred to as a particle shower , moving at approximately the speed of light . passing through , the cascade will ionize the medium , leaving behind a plasma tube . the different properties of the plasma - tube , such as its lifetime , size and the charge - density will be used to obtain an estimate if it is possible to detect this tube by means of the radar detection technique . next to the ionization electrons a second plasma due to mobile protons induced by the particle cascade is discussed . an energy threshold for the cascade inducing particle of 4 pev for the electron plasma , and 20 pev for the proton plasma is obtained . this allows the radar detection technique , if successful , to cover the energy - gap between several pev and a few eev in the currently operating neutrino detectors , where on the low side icecube runs out of events , and on the high side the askaryan radio detectors begin to have large effective volumes . cosmic rays , neutrinos , radio detection , radar . And you have already written the first three sentences of the full article: recently the icecube neutrino observatory @xcite for the first time showed the existence of high - energy cosmic neutrinos . since neutrinos are not deflected by magnetic fields in our universe , they should point back to their original source . this opens a new field in physics , the field of neutrino astronomy . at the highest energies , these cosmic neutrinos are extremely rare . at energies above several pev , icecube runs out of events and an even larger detector volume than the 1 km@xmath0 covered by icecube. Please generate the next two sentences of the article

is needed for their detection . due to the long attenuation length of the radio signal , the radio detection technique is an excellent candidate to detect these rare events .

Suppose that you have an abstract for a scientific paper: in low - rank matrix recovery , one aims to reconstruct a low - rank matrix from a minimal number of linear measurements . within the paradigm of compressed sensing , this is made computationally efficient by minimizing the nuclear norm as a convex surrogate for rank . in this work , we identify an improved regularizer based on the so - called diamond norm , a concept imported from quantum information theory . we show that for a class of matrices saturating a certain norm inequality the descent cone of the diamond norm is contained in that of the nuclear norm . this suggests superior reconstruction properties for these matrices and we explicitly characterize this set . we demonstrate numerically that the diamond norm indeed outperforms the nuclear norm in a number of relevant applications : these include signal analysis tasks such as blind matrix deconvolution or the retrieval of certain unitary basis changes , as well as the quantum information problem of process tomography with random measurements . the diamond norm is defined for matrices that can be interpreted as order-4 tensors and it turns out that the above condition depends crucially on that tensorial structure . in this sense , this work touches on an aspect of the notoriously difficult tensor completion problem . . And you have already written the first three sentences of the full article: the task of recovering an unknown low - rank matrix from a small number of measurements appears in a variety of contexts . examples of this task are provided by collaborative filtering in machine learning @xcite , quantum state tomography in quantum information @xcite , the estimation of covariance matrices @xcite , or face recognition @xcite . if the measurements are linear , the technical problem reduces to identifying the lowest - rank element in an affine space of matrices . in general , this problem is @xmath0-hard and it is thus unclear how to approach it algorithmically @xcite . in the wider field of compressed sensing @xcite , the strategy for treating such problems is to replace the complexity measure here the rank with a tight convex relaxation .. Please generate the next two sentences of the article

often , it can be rigorously proved that the resulting convex optimization problem has the same solution as the original problem for many relevant problems , while at the same time allowing for an efficient algorithm . the tightest ( in some sense @xcite ) convex relaxation of rank is the _ nuclear norm _ , i.e. the sum of singular values .

Suppose that you have an abstract for a scientific paper: we consider the ising model on an @xmath0 rectangular lattice with an asymmetric self - dual boundary condition , and derive a closed - form expression for its partition function . we show that zeroes of the partition function are given by the roots of a polynomial equation of degree @xmath1 , which trace out certain loci in the complex temperature plane . particularly , it is shown that ( a ) real solutions of the polynomial equations always lead to zeroes on the unit circle and a segment of the negative real axis , and ( b ) all temperature zeroes lie on two circles in the limit of @xmath2 for any @xmath3 . closed - form expressions of the loci as well as the density of zero distributions in the limit of @xmath4 are derived for @xmath5 and 2 . in addition , we explain the reason of , and establish the criterion for , partition function zeroes of any self - dual spin model to reside precisely on the unit circle . this elucidates a recent finding in the case of the self - dual potts model . @xmath6 . And you have already written the first three sentences of the full article: one of the most remarkable results in statistical mechanics is the circle theorem of yang and lee @xcite who in 1952 established that zeroes of the partition function of the ferromagnetic ising model always lie on the unit circle in the complex @xmath7 plane , where @xmath8 is the reduced magnetic field variable . in 1964 fisher @xcite pointed out that it is also meaningful to consider zeroes of the ising partition function in the complex temperature plane , in which the zeroes reside on a boundary at which the free energy becomes non - analytic . particularly , he showed that temperature zeroes of the square lattice ising model lie on two circles in the thermodynamic limit . since then the consideration of the partition function zeroes has become a power tool in analyzing lattice models .. Please generate the next two sentences of the article

the temperature zeroes of the ising model @xcite as well as the potts model @xcite have been investigated . however , studies to this date have been confined mostly to results in the thermodynamic limit @xcite and/or numerical analyses @xcite .

Suppose that you have an abstract for a scientific paper: in the unification scheme , radio quasars and fr ii radio galaxies come from the same parent population , but viewed at different angles . based on the comptonization models for the @xmath0-ray emission from active galactic nuclei ( agns ) , we estimate the number of radio quasars and fr ii radio galaxies to be detected by the _ gamma - ray large area space telescope _ ( glast ) using the luminosity function ( lf ) of their parent population derived from the flat - spectrum radio quasar ( fsrq ) lf . we find that @xmath1 radio quasars will be detected by glast , if the soft seed photons for comptonization come from the regions outside the jets . we also consider the synchrotron self - comptonization ( ssc ) model , and find it unlikely to be responsible for @xmath0-ray emission from radio quasars . we find that no fr ii radio galaxies will be detected by glast . our results show that most radio agns to be detected by glast will be fsrqs ( @xmath299% for the external comptonization model , ec model ) , while the remainder ( @xmath21% ) will be steep - spectrum radio quasars ( ssrqs ) . this implies that fsrqs will still be good candidates for identifying @xmath0-ray agns even for the glast sources . the contribution of all radio quasars and fr ii radio galaxies to the extragalactic @xmath0-ray background ( egrb ) is calculated , which accounts for @xmath230% of the egrb . . And you have already written the first three sentences of the full article: the third catalog of @xmath0-ray agns detected by the energetic gamma - ray experiment telescope ( egret ) on the _ compton gamma - ray observatory ( cgro ) _ includes @xmath2 80 high - confidence identifications of blazars ( e.g. , * ? ? ? * ; * ? ? ? glast has higher sensitivity than egret , and much more blazars are expected to be detected after its launch .. Please generate the next two sentences of the article

many workers have predicted the statistic properties of blazars in the glast era ( e.g. , * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: the very metal - poor star he 0338 - 3945 shows a double - enhanced pattern of the neutron - capture elements . the study to this sample could make people gain a better understanding of s- and r - process nucleosynthesis at low metallicity . using a parametric model , we find that the abundance pattern of the neutron - capture elements could be best explained by a binary system formed in a molecular cloud , which had been polluted by r - process material . the observed abundance pattern of c and n can be explained by an agb model @xcite . combing with the parameters obtained from @xcite , we suggest that the initial mass of the agb companion is most likely to be about @xmath0 , which excludes the possibility of forming a type-1.5 supernova . by comparing with the observational abundance pattern of cs 22892 - 052 , we find that the dominating production of o should accompany with the production of the heavy r - process elements of r+s stars . similar to r - ii stars , the heavy r - process elements are not produced in conjunction with all the light elements from na to fe group . the abundance pattern of the light and r - process elements for he 0338 - 3945 is very close to the pattern of the r - ii star cs 22892 - 052 . so , we suggest that this star he 0338 - 3945 should be a special r - ii star . . And you have already written the first three sentences of the full article: the two neutron - capture processes , i.e. the ( slow ) s - process and the ( rapid ) r - process , occur under different physical conditions and are therefore likely to arise in different astrophysical sites . the dominant site of the s - process is thought to be the asymptotic giant branch ( agb ) phase in low- and intermediate - mass stars @xcite . the site or sites of the r - process are not known , although suggestions include the @xmath1-driven wind of type ii supernovae @xcite , the mergers of neutron stars @xcite , accretion - induced collapse ( aic ; * ? ? ?. Please generate the next two sentences of the article

* ) , and type 1.5 supernovae @xcite . the neutron - capture elements are composed of some pure r - process , some pure s - process , and some mixed - parentage isotopes . as a result ,

Suppose that you have an abstract for a scientific paper: we study the propagating gravitational waves as a tool to probe the extra dimensions . in the set - up with one compact extra dimension and non - gravitational physics resigning on the 4-dimensional subspace ( brane ) of 5-dimensional spacetime we find the green s function describing the propagation of 5-dimensional signal along the brane . the green s function has a form of the sum of contributions from large number of images due to the compactness of the fifth dimension . additionally , a peculiar feature of the causal wave propagation in five dimensions ( making a five - dimensional spacetime very much different from the familiar four - dimensional case ) is that the entire region inside the past light - cone contributes to the signal at the observation point . the 4-dimensional propagation law is nevertheless reproduced at large ( compared to the size of extra dimension ) intervals from the source as a superposition of signals from large number of images . the fifth dimension however shows up in the form of corrections to the purely 4-dimensional picture . we find three interesting effects : a tail effect for a signal of finite duration , screening at the forefront of this signal and a frequency - dependent amplification for a periodic signal . we discuss implications of these effects in the gravitational wave astronomy and estimate the sensitivity of gravitational antenna needed for detecting the extra dimension . 0.5 cm + 0.4 cm 2truecm * echoing the extra dimension * + 1truecm * a. o. barvinsky@xmath0 and sergey n. solodukhin@xmath1 * + 0.6truecm _ @xmath2 theory department , lebedev physics institute , + leninsky prospect 53 , moscow 117924 , russia 0.4truecm _ _ _ @xmath1theoretische physik , ludwig - maximilians universitt , theresienstrasse 37 , d-80333 , mnchen , germany 1truemm 1truecm . And you have already written the first three sentences of the full article: over decades since the works of kaluza and klein the idea of extra dimensions enjoys constantly growing interest of the physical community . designed originally to serve the unification of the general relativity and maxwell electrodynamics it is now more fashionable to invoke the extra dimensions for solving the problems of hierarchy and vacuum energy . a recent review on old and new paths to the extra dimensions is @xcite . it is customary nowadays to consider the kaluza - klein idea in the context of the brane paradigm . according to this picture ,. Please generate the next two sentences of the article

the non - gravitational physics , conveniently described by the standard model , is confined to a @xmath3-dimensional subspace called brane of the @xmath4-dimensional space - time with @xmath5 compactified extra dimensions . only gravitational field is allowed to propagate through the whole spacetime and probe the extra dimensions .

Suppose that you have an abstract for a scientific paper: let @xmath0 be a nilpotent endomorphism of a finite dimensional @xmath1-vector space . the set @xmath2 of @xmath0-stable complete flags is a projective algebraic variety called a springer fiber . its irreducible components are parameterized by a set of standard tableaux . we provide three characterizations of the singular components of @xmath2 in the case @xmath3 . first , we give the combinatorial description of standard tableaux corresponding to singular components . second , we prove that a component is singular if and only if its poincar polynomial is not palindromic . third , we show that a component is singular when it has too many intersections of codimension one with other components . finally , relying on the second criterion , we infer that , for @xmath0 general , whenever @xmath2 has a singular component , it admits a component whose poincar polynomial is not palindromic . this work relies on a previous criterion of singularity for components of @xmath2 in the case @xmath3 by the first author and on the description of the @xmath4-orbit decomposition of orbital varieties of nilpotent order two by the second author . _ keywords . _ flag varieties , springer fibers , young tableaux , link patterns , singularity criteria , poincar polynomial . And you have already written the first three sentences of the full article: let @xmath5 be a @xmath1-vector space of dimension @xmath6 and let @xmath7 be a nilpotent endomorphism . let @xmath8 be the set of complete flags , i.e. maximal chains of subspaces @xmath9 . the set @xmath8 is a projective algebraic variety , called the _ flag variety_. let @xmath2 be the subset of @xmath0-stable complete flags , i.e. flags @xmath10 such that @xmath11 for every @xmath12 .. Please generate the next two sentences of the article

the set @xmath2 is a closed subvariety of @xmath8 . it is called _ springer fiber _ , since it can be identified with the fiber over @xmath0 of the springer resolution ( see @xcite , @xcite ) .

Suppose that you have an abstract for a scientific paper: we test the consistency of estimates of the non - linear coupling constant @xmath0 using non - gaussian cmb maps generated by the method described in ( liguori , matarrese and moscardini 2003 ) . this procedure to obtain non - gaussian maps differs significantly from the method used in previous works on estimation of @xmath0 . nevertheless , using spherical wavelets , we find results in very good agreement with ( mukherjee and wang 2004 ) , showing that the two ways of generating primordial non - gaussian maps give equivalent results . moreover , we introduce a new method for estimating the non - linear coupling constant from cmb observations by using the local curvature of the temperature fluctuation field . we present both bayesian credible regions ( assuming a flat prior ) and proper ( frequentist ) confidence intervals on @xmath0 , and discuss the relation between the two approaches . the bayesian approach tends to yield lower error bars than the frequentist approach , suggesting that a careful analysis of the different interpretations is needed . using this method , we estimate @xmath1 at the @xmath2 level ( bayesian ) and @xmath3 ( frequentist ) . moreover , we find that the wavelet and the local curvature approaches , which provide similar error bars , yield approximately uncorrelated estimates of @xmath4 and therefore , as advocated in ( cabella et al . 2004 ) , the estimates may be combined to reduce the error bars . in this way , we obtain @xmath5 and @xmath6 at the @xmath7 and @xmath2 level respectively using the frequentist approach . [ firstpage ] cosmic microwave background - cosmology : theory - methods : numerical - methods : statistical - cosmology : observations . And you have already written the first three sentences of the full article: inflation is the standard paradigm for providing the initial conditions for structure formation and cosmic microwave background ( cmb ) anisotropy generation . in the inflationary picture , primordial adiabatic perturbations arise from quantum fluctuations of the _ inflaton _ scalar field which drives the accelerated universe expansion . in the simplest models , the inflaton is assumed to have a shallow potential , thereby leading to a slow rolling of this field down its potential .. Please generate the next two sentences of the article

the flatness of the potential implies that intrinsic non - linear ( hence non - gaussian ) effects during slow - roll inflation are tiny , although non - zero and calculable @xcite . to quantitatively describe the theoretical findings in this framework , let us introduce a useful parameterisation of non - gaussianity according to which the primordial gravitational potential @xmath8 is given by a linear gaussian term @xmath9 , plus a quadratic contribution , as follows ( e.g. @xcite ) : @xmath10 ( up to a constant offset , which only affects the monopole contribution ) , where the dimensionless parameter @xmath0 sets the strength of non - gaussianity .

Suppose that you have an abstract for a scientific paper: we present results from the first observations of the hubble space telescope ( hst ) panchromatic comparative exoplanet treasury ( pancet ) program for wasp-101b , a highly inflated hot jupiter and one of the community targets proposed for the james webb space telescope ( jwst ) early release science ( ers ) program . from a single hst wide field camera 3 ( wfc3 ) observation , we find that the near - infrared transmission spectrum of wasp-101b contains no significant h@xmath0o absorption features and we rule out a clear atmosphere at 13@xmath1 . therefore , wasp-101b is not an optimum target for a jwst ers program aimed at observing strong molecular transmission features . we compare wasp-101b to the well studied and nearly identical hot jupiter wasp-31b . these twin planets show similar temperature - pressure profiles and atmospheric features in the near - infrared . we suggest exoplanets in the same parameter space as wasp-101b and wasp-31b will also exhibit cloudy transmission spectral features . for future hst exoplanet studies , our analysis also suggests that a lower count limit needs to be exceeded per pixel on the detector in order to avoid unwanted instrumental systematics . . And you have already written the first three sentences of the full article: observations of hot jupiters with hubble space telescope ( hst ) have revealed a diversity of atmospheres from clear to cloudy ( @xcite ) . in the near - infrared with wide field camera 3 ( wfc3 ) , significant water absorption features have been measured for a number of exoplanets ( e.g. , @xcite ) . however , a significant number also show little or no evidence of water absorption ( e.g. , @xcite ) , which is plausibly due to clouds high in the planetary atmosphere ( @xcite ) .. Please generate the next two sentences of the article

a number of studies across temperature , mass , and metallicity ranges for exoplanets have shown that clouds and aerosols will likely play a critical role in exoplanetary atmospheres ( e.g. , @xcite ) . several studies , such as by @xcite , have shown that with a cloud - free atmosphere key constraints can be placed on the abundance of both water and carbon - species , important in breaking the c / o - metallicity dependence .

Suppose that you have an abstract for a scientific paper: optical observations of the type ia supernova ( sn ia ) 2005bl in ngc 4070 , obtained from @xmath0 to @xmath1d with respect to the @xmath2-band maximum , are presented . the photometric evolution is characterised by rapidly - declining light curves ( @xmath3m@xmath4 ) and red colours at peak and soon thereafter . with m@xmath5 the sn is an underluminous sn ia , similar to the peculiar sne 1991bg and 1999by . this similarity also holds for the spectroscopic appearance , the only remarkable difference being the likely presence of carbon in pre - maximum spectra of sn 2005bl . a comparison study among underluminous sne ia is performed , based on a number of spectrophotometric parameters . previously reported correlations of the light - curve decline rate with peak luminosity and @xmath6(si ) are confirmed , and a large range of post - maximum siii @xmath7 velocity gradients is encountered . 1d synthetic spectra for sn 2005bl are presented , which confirm the presence of carbon and suggest an overall low burning efficiency with a significant amount of leftover unburned material . also , the fe content in pre - maximum spectra is very low , which may point to a low metallicity of the precursor . implications for possible progenitor scenarios of underluminous sne ia are briefly discussed . [ firstpage ] supernovae : general supernovae : individual : sn 2005bl supernovae : individual : sn 1991bg supernovae : individual : sn 1999by supernovae : individual : sn 1998de galaxies : individual : ngc 4070 . . And you have already written the first three sentences of the full article: the history of underluminous sne ia is a typical example of the ever - recurring pattern in which knowledge about nature is accumulated . usually , in the beginning there is the observation of a phenomenon , followed by a successful theoretical explanation . however , as further experiments or observations are carried out in order to confirm the newly developed theoretical ideas , often an ever higher degree of diversity and ever more exceptions from the simple rules are found the closer the subject of interest is studied .. Please generate the next two sentences of the article

the need for refined and more complex theories to obtain a realistic description of the involved processes becomes evident . in the case of sne ia , first a class of cosmic explosions apparently similar in absolute luminosity ( `` standard candles '' ) and spectroscopic appearance was identified .

Suppose that you have an abstract for a scientific paper: in this paper we report a relaxation induced suppression of the noise for a single level quantum dot coupled to an oscillator with incoherent dynamics in the sequential tunneling regime . it is shown that relaxation induces qualitative changes in the transport properties of the dot , depending on the strength of the electron - phonon coupling and on the applied voltage . in particular , critical thresholds in voltage and relaxation are found such that a suppression below @xmath0 of the fano factor is possible . additionally , the current is either enhanced or suppressed by increasing relaxation , depending on bias being greater or smaller than the above threshold . these results exist for any strength of the electron phonon coupling and are confirmed by a four states toy model . . And you have already written the first three sentences of the full article: in the last years , nanoelectromechanical systems ( nems ) have been a hot research topic both from the theoretical and the experimental point of view . @xcite combining electronic and mechanical degrees of freedom , nems have potentially important applications as fast and ultra sensitive detectors , @xcite as well as being interesting dynamical systems in their own right . in these devices , current can be used both to create and to detect vibrational excitations .. Please generate the next two sentences of the article

clear evidence of phonon excitations induced by single electron tunneling has been reported in a number of different systems , including semiconducting phonon cavities , @xcite molecules @xcite and suspended carbon nanotubes . @xcite at finite bias electrons tend to drive phonons out of equilibrium ; signatures of non equilibrium phonon distribution were observed in a suspended carbon nanotube .

Suppose that you have an abstract for a scientific paper: jahn - teller ( jt ) effect both in the absence and presence of the strong coulomb correlation is studied theoretically focusing on the reduction @xmath0 of the kinetic energy gain which is directly related to the spin wave stiffness . without the coulomb interaction , the perturbative analysis gives @xmath1 depending on the electron number [ @xmath2 : electron - phonon(el - ph ) coupling constant , @xmath3 : mass of the oxygen atom , @xmath4 : frequency of the phonon ] . although there occurs many channels of the jt el - ph interaction in the multiband system , the final results of @xmath0 roughly scales with the density of states at the fermi energy . in the limit of strong electron correlation , the magnitude of the orbital polarization saturate and the relevant degrees of freedom are the direction ( phase ) of it . an effective action is derived for the phase variable including the effect of the jt interaction . in this limit , jt interaction is _ enhanced _ compared with the non - interacting case , and @xmath0 is given by the lattice relaxation energy @xmath5 for the localized electrons , although the electrons remains itinerant . discussion on experiments are given based on these theoretical results . . And you have already written the first three sentences of the full article: it has been recognized that in the strongly correlated electronic systems both the electron - phonon ( el - ph ) and electron - electron ( el - el ) interaction are enhanced and play important roles . in manganites , the colossal magneto - resistance ( cmr ) @xcite has been discussed from both points of view . in this system the ferromagnetism is basically explained by the double exchange model.@xcite however the orbital degeneracy of the @xmath6-states is considered to be very important , and the orbital ordering or disordering is the crucial issue for the understanding of the cmr effect . @xcite therefore there are two viewpoints on this problem , namely the orbital degrees of freedom is governed by ( i ) the jahn - teller ( jt ) electron - phonon coupling or ( ii ) the electron correlation . in the former case ,. Please generate the next two sentences of the article

the change of the bandwidth due to the crossover from small to large jt - polaron is the key mechanism of the cmr effect , and the jt effect is assumed to be negligible in the ferromagnetic metallic state . @xcite this picture appear contradicting with the orbital orderings , which require rather strong coupling , surrounding the ferromagnetic region in the phase diagram .

Suppose that you have an abstract for a scientific paper: this work addresses computing techniques for dose calculations in treatment planning with proton and ion beams , based on an efficient kernel - convolution method referred to as grid - dose spreading ( gds ) and accurate heterogeneity - correction method referred to as gaussian beam splitting . the original gds algorithm suffered from distortion of dose distribution for beams tilted with respect to the dose - grid axes . use of intermediate grids normal to the beam field has solved the beam - tilting distortion . interplay of arrangement between beams and grids was found as another intrinsic source of artifact . inclusion of rectangular - kernel convolution in beam transport , to share the beam contribution among the nearest grids in a regulatory manner , has solved the interplay problem . this algorithmic framework was applied to a tilted proton pencil beam and a broad carbon - ion beam . in these cases , while the elementary pencil beams individually split into several tens , the calculation time increased only by several times with the gds algorithm . the gds and beam - splitting methods will complementarily enable accurate and efficient dose calculations for radiotherapy with protons and ions . proton , ion beam , pencil - beam algorithm , treatment planning , inhomogeneity correction 87.55.d- , 87.55.kd . And you have already written the first three sentences of the full article: dose distributions of radiotherapy are represented by point doses at orthogonally arranged grids . in treatment - planning practice , the grid intervals are defined from a physical , clinical , and practical points of view , often resulting in cubic dimensions of a few millimeters . accuracy , efficiency and their balance are essential in practice , for which the pencil - beam algorithm is commonly used .. Please generate the next two sentences of the article

that is mathematically a convolution integral of total energy released per mass ( terma ) with elementary beam - spread kernel , which may be computationally demanding . the grid - dose - spreading ( gds ) algorithm was developed for fast dose calculation of heavy - charged - particle beams in patient body @xcite .

Suppose that you have an abstract for a scientific paper: the diffuse high - energy gamma - ray emission of the milky way arises from interactions of cosmic - rays ( crs ) with interstellar gas and radiation field in the galaxy . the neutral hydrogen ( h i ) gas component is by far the most massive and broadly distributed component of the interstellar medium . using the 21-cm emission line from the hyperfine structure transition of atomic hydrogen it is possible to determine the column density of h i if the spin temperature ( @xmath0 ) of the emitting gas is known . studies of diffuse gamma - ray emission have generally relied on the assumption of a fixed , constant spin temperature for all h i in the milky way . unfortunately , observations of h i in absorption against bright background sources has shown it to vary greatly with location in the milky way . we will discuss methods for better handling of spin temperatures for galactic diffuse emission modeling using the fermi - lat data and direct observation of the spin temperature using h i absorption . . And you have already written the first three sentences of the full article: the diffuse galactic emission ( dge ) arises from interactions of cosmic - rays ( crs ) with interstellar gas and radiation field in the galaxy . due to the smooth nature of the interstellar radiation field and the cr flux after propagation , the fine structure of the dge is determined by the structure of the interstellar gas . getting the distribution of the interstellar gas correct is therefore crucial when modeling the dge .. Please generate the next two sentences of the article

it is generally assumed that galactic crs are accelerated in interstellar shocks and then propagate throughout the galaxy ( see e.g. * ? ? ? * for a recent review . ) . in this paper , cr propagation and corresponding diffuse emission is calculated using the galprop code ( see * ? ? ? * and references within . ) .

Suppose that you have an abstract for a scientific paper: we present abundances for 20 elements for stars in two stellar streams identified by @xcite : 18 stars from the arcturus stream and 26 from a new stream , which we call af06 stream , both from the galactic thick disk . results show both streams are metal - poor and very old ( 10@xmath014 gyrs ) with kinematics and abundances overlapping with the properties of local field thick disk stars . both streams exhibit a range in metallicity but with relative elemental abundances that are identical to those of thick disk stars of the same metallicity . these results show that neither stream can result from dissolution of an open cluster . it is highly unlikely that either stream represents tidal debris from an accreted satellite galaxy . both streams most probably owe their origin to dynamical perturbations within the galaxy . [ firstpage ] stars : abundances stars : moving groups galaxy : kinematics and dynamics galaxy : disk . And you have already written the first three sentences of the full article: the phase space of the galaxy s disk , as observed near the sun , contains substructure within the larger structures known as the thin and the thick disk . substructures include open clusters and stellar streams , also often referred to as moving groups . moving groups , as promoted by eggen ( see e.g. , @xcite and references therein ) , are considered to be stars having a common space motion and a common chemical composition , and originating from a disssolving open cluster . while some of the well known moving groups do share a common composition ( e.g. , the hr 1614 group - @xcite ) suggesting they come from a tidally - disrupted open cluster , other groups contain stars having very different compositions , a result demanding an origin more complex than disruption of an open cluster .. Please generate the next two sentences of the article

the term ` stream ' is now applied to some entities in galactic phase space . examples in the thin disk include the hercules stream @xcite and the hyades stream or supercluster ( @xcite , @xcite ) . for streams in the thin disk ,

Suppose that you have an abstract for a scientific paper: we estimate the numbers and mass spectra of observed lepton and kaon pairs produced from @xmath0 meson decays in the central rapidity region of an au+au collision at lab energy 11.6 gev / nucleon . the following effects are considered : possible mass shifts , thermal broadening due to collisions with hadronic resonances , and superheating of the resonance gas . changes in the dilepton mass spectrum may be seen , but changes in the dikaon spectrum are too small to be detectable . . And you have already written the first three sentences of the full article: there is currently a great deal of interest in finite - temperature properties of hadronic resonances @xcite . recently , preliminary results for the @xmath0 meson mass spectrum in si+au collisions at lab energy 11.6 gev / nucleon were obtained at brookhaven s alternating gradient synchrotron ( ags ) , by reconstructing the @xmath0 mesons from final - state kaon pairs @xcite . no change was observed from the vacuum width of the @xmath0 , although a possible small mass shift was observed for the most central events . these negative preliminary results could dampen the enthusiasm of other groups to study the @xmath0 peak in the dilepton channel .. Please generate the next two sentences of the article

we show here that no observable change is expected for the @xmath0 peak in the dikaon spectrum , but that effects may be visible in the dilepton spectrum . thus , there is still good reason to study the dilepton @xmath0 peak at the ags , in spite of the fact that dikaon results are negative .

Suppose that you have an abstract for a scientific paper: integer - forcing ( if ) linear receiver has been recently introduced for multiple - input multiple - output ( mimo ) fading channels . the receiver has to compute an integer linear combination of the symbols as a part of the decoding process . in particular , the integer coefficients have to be chosen based on the channel realizations , and the choice of such coefficients is known to determine the receiver performance . the original known solution of finding these integers was based on exhaustive search . a practical algorithm based on hermite - korkine - zolotareff ( hkz ) and minkowski lattice reduction algorithms was also proposed recently . in this paper , we propose a low - complexity method based on complex lll algorithm to obtain the integer coefficients for the if receiver . for the @xmath0 mimo channel , we study the effectiveness of the proposed method in terms of the ergodic rate . we also compare the bit error rate ( ber ) of our approach with that of other linear receivers , and show that the suggested algorithm outperforms the minimum mean square estimator ( mmse ) and zero - forcing ( zf ) linear receivers , but trades - off error performance for complexity in comparison with the if receiver based on exhaustive search or on hkz and minkowski lattice reduction algorithms . clll algorithm , mimo , linear receivers . . And you have already written the first three sentences of the full article: in multipath fading channels , using multiple antennas at the transceivers is known to provide large capacity gains . such a capacity gain comes at the cost of high decoding complexity at the receiver . it is known that a high - complexity joint ml decoder can be employed at the receiver to reliably recover the information . on the other hand , the _ linear receivers _ such as the zf and the mmse receiver. Please generate the next two sentences of the article

@xcite reduce the decoding complexity trading - off error performance . the integer forcing ( if ) linear receiver has been recently proposed @xcite this new architecture obtains high rates in mimo fading channels . in this approach

Suppose that you have an abstract for a scientific paper: we generalize the asymptotic shape theorem in first passage percolation on @xmath0 to cover the case of general semimetrics . we prove a structure theorem for equivariant semimetrics on topological groups and an extended version of the maximal inequality for @xmath0-cocycles of boivin and derriennic in the vector - valued case . this inequality will imply a very general form of kingman s subadditive ergodic theorem . for certain classes of generalized first passage percolation , we prove further structure theorems and provide rates of convergence for the asymptotic shape theorem . we also establish a general form of the multiplicative ergodic theorem of karlsson and ledrappier for cocycles with values in separable banach spaces with the radon nikodym property . . . And you have already written the first three sentences of the full article: first passage percolation was introduced by hammersley and welsh in @xcite . a detailed description of the model is given in section [ class ] . the theory can be roughly described as the study of the generic large - scale geometry of semimetric spaces , where the semimetric is allowed to vary measurably .. Please generate the next two sentences of the article

the classical case deals with the space @xmath0 and semimetrics induced by random weights on the edges of the standard cayley graph of @xmath0 . however , the setup easily extends to general groups . in this paper , we introduce the notion of a random semimetric .

Suppose that you have an abstract for a scientific paper: we study the stability of static black holes in lovelock theory which is a natural higher dimensional generalization of einstein theory . we derive a master equation for tensor perturbations in general lovelock theory . it turns out that the resultant equation is characterized by one functional which determines the background black hole solutions . thus , the stability issue of static black holes under tensor perturbations in general dimensions is reduced to an algebraic problem . we show that small lovelock black holes in even - dimensions are unstable . . And you have already written the first three sentences of the full article: it is well known that string theory can be formulated only in ten dimensions . hence , it is necessary to reconcile this prediction with our real world by compactifying extra - dimensions or by considering braneworld . intriguingly , in the context of the braneworld with large extra - dimensions , black holes could be created at the tev scale @xcite .. Please generate the next two sentences of the article

hence , the stability of higher dimensional black holes becomes important since these black holes could be produced at the lhc if the spacetime has larger than six dimensions . the stability of higher dimensional black holes has been an active topic since the seminal papers by kodama and ishibashi @xcite . it is important to study various black holes in einstein theory because black holes produced at the lhc are expected to be charged or rotating .

Suppose that you have an abstract for a scientific paper: we present a numerical study of noise correlations , i.e. , density - density correlations in momentum space , in the extended fermionic hubbard model in one dimension . in experiments with ultracold atoms , these noise correlations can be extracted from time - of - flight images of the expanding cloud . using the density - matrix renormalization group method to investigate the hubbard model at various fillings and interactions , we confirm that the noise correlations contain full information on the most important fluctuations present in the system . we point out the importance of the sum rules fulfilled by the noise correlations and show that they yield nonsingular structures beyond the predictions of bosonization approaches . noise correlations can thus serve as a universal probe of order and can be used to characterize the many - body states of cold atoms in optical lattices . . And you have already written the first three sentences of the full article: recent advances in methods for trapping and controlling ultracold atoms have opened up the promising possibility of directly simulating strongly interacting many - body hamiltonians . these experimental systems can be used to engineer and analyze models that lie beyond the scope of present analytical and numerical methods , thus potentially shedding new light on fundamental quantum many - body problems @xcite such as the the nature of the mechanism for high-@xmath0 superconductivity or whether a true spin liquid can be realized . such systems can be formed by trapping atomic gases in one- , two- , or three - dimensional optical lattices .. Please generate the next two sentences of the article

the interactions can be accurately tuned by adjusting external fields . in a similar spirit , it has recently been proposed to simulate strongly correlated systems in experiments by studying the dynamics of polaritons in arrays of electromagnetic cavities , see ref . . the techniques for manipulating ultracold atoms are fairly advanced and have already enabled a broad range of astonishing systems , such as a superfluid , a mott insulator @xcite , a strongly interacting fermi gas @xcite or also mixtures of bosonic and fermionic gases @xcite .

Suppose that you have an abstract for a scientific paper: we study a simple one - loop induced neutrino mass model that contains both bosonic and fermionic dark matter candidates and has the capacity to explain the muon anomalous magnetic moment anomaly . we perform a comprehensive analysis by taking into account the relevant constraints of charged lepton flavor violation , electric dipole moments , and neutrino oscillation data . we examine the constraints from lepton flavor - changing @xmath0 boson decays at one - loop level , particularly when the involved couplings contribute to the muon @xmath1 . it is found that @xmath2 - @xmath3 while @xmath4 in the fermionic dark matter scenario . the former can be probed by the precision measurement of the @xmath0 boson at future lepton colliders . . And you have already written the first three sentences of the full article: even though the standard model ( sm ) of particle physics has been very successfully predicting or explaining most experimental results and phenomena , it still has a few outstanding problems with empirical observations . one is the origin of neutrino mass as inferred from neutrino oscillation experiments . we still do not know whether it is of dirac or majorana type and whether it has a normal or inverted hierarchy . another one is the existence of dark matter in the universe . despite its immense gravitational effects at the cosmological scale. Please generate the next two sentences of the article

, we do not know what kind of object it is and how it interacts with sm particles otherwise . radiative seesaw models provide one of the promising scenarios to explain the neutrino oscillation data and dark matter candidates simultaneously .

Suppose that you have an abstract for a scientific paper: the number of known diffuse radio sources in clusters of galaxies has grown in recent years , making it possible to derive statistical properties of these sources and of the hosting clusters . we show that diffuse sources are associated with x - ray luminous clusters which have undergone recent merger processes . the radio and x - ray structures are often similar , and correlations are found between radio and x - ray parameters . this is indication of a link between the diffuse relativistic and thermal plasma in clusters of galaxies . # 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: it is well established that an important component of the intergalactic medium ( igm ) in clusters and groups of galaxies is the hot gas , observed in x - rays and characterized by temperatures in the range @xmath05 - 10 kev , by a central density of @xmath010@xmath1 cm@xmath1 and by a density distribution approximated by a beta model ( cavaliere & fusco - femiano 1981 ) . in addition , magnetic fields are wide spread in clusters ( e.g. eilek 1999 ) , as deduced by rotation measure arguments , and relativistic electrons may be common ( sarazin & lieu 1998 ) . these two non - thermal components can be directly revealed in some clusters by the presence of diffuse extended radio sources , which are related to the intergalactic medium , rather than to a particular cluster galaxy .. Please generate the next two sentences of the article

however , diffuse sources seem not to be a general property of the igm . the importance of these sources is that they represent large scale features , which are related to other cluster properties in the optical and x - ray domain , and are thus directly connected to the cluster history and evolution . in this paper ,

Suppose that you have an abstract for a scientific paper: this note introduces the construction of relational symplectic groupoids as a way to integrate every poisson manifold . examples are provided and the equivalence , in the integrable case , with the usual notion of symplectic groupoid is discussed . . And you have already written the first three sentences of the full article: symplectic groupoids @xcite are lie groupoids with a compatible symplectic structure . their space of objects is naturally endowed with a poisson structure . in a sense , a symplectic groupoid is a good symplectic replacement for the base poisson manifold and is also related to its quantization . this beautiful picture has one fault : namely , not every poisson manifold arises as the space of objects of a symplectic groupoid .. Please generate the next two sentences of the article

moreover , the symplectic category is not the correct classical analogue of the category of hilbert spaces which appears in quantum mechanics . the goal of this paper is to define a more general structure , which we call a relational symplectic groupoid and of which ordinary symplectic groupoids are a particular case , as a

Suppose that you have an abstract for a scientific paper: we calculate the transverse correlation of fluctuations of the deposited energy density in nuclear collisions in the framework of the gaussian color glass condensate model . . And you have already written the first three sentences of the full article: the event - by - event fluctuations of the transverse emission pattern of hadrons in high - energy collisions of identical heavy nuclei have recently attracted much interest experimentally @xcite and theoretically @xcite . when averaged over collision events , the azimuthal angular distribution of emitted hadrons around the beam axis is symmetric with respect to the plane perpendicular to the impact parameter vector @xmath0 between the two nuclei [ au+au or cu+cu at the relativistic heavy ion collider ( rhic ) or pb+pb at the large hadron collider ( lhc ) ] . the event averaged angular distribution @xmath1 where @xmath2 is the angle between @xmath3 and @xmath0 , is therefore completely characterized by the even fourier coefficients @xmath4 .. Please generate the next two sentences of the article

the dominant coefficient , @xmath5 , is called elliptic flow . owing to quantum fluctuations in the density distributions of the colliding nuclei and finite particle number effects on the distribution of emitted particles , the left - right symmetry is broken in individual collision events .

Suppose that you have an abstract for a scientific paper: we present an overview of a recently suggested new model of quantum initial conditions for the universe in the form of a cosmological density matrix . this density matrix originally suggested in the euclidean quantum gravity framework turns out to describe the microcanonical ensemble in the lorentzian quantum gravity of spatially closed cosmological models . this ensemble represents an equipartition in the physical phase space of the theory ( sum over everything ) , but in terms of the observable spacetime geometry it is peaked about a set of cosmologies limited to a bounded range of the cosmological constant . this suggests a mechanism to constrain the landscape of string vacua and a possible solution to the dark energy problem in the form of the quasi - equilibrium decay of the microcanonical state of the universe . the effective friedmann equation governing this decay incorporates the effect of the conformal anomaly of quantum fields and features a new mechanism for a cosmological acceleration stage big boost scenario . we also briefly discuss the relation between our model , the ads / cft correspondence and rs and dgp braneworlds . . And you have already written the first three sentences of the full article: it is widely recognized that euclidean quantum gravity ( eqg ) is a lame duck in modern particle physics and cosmology . after its summit in early and late eighties ( in the form of the cosmological wavefunction proposals @xcite and baby universes boom @xcite ) the interest in this theory gradually declined , especially , in cosmological context , where the problem of quantum initial conditions was superseded by the concept of stochastic inflation @xcite . eqg could not stand the burden of indefiniteness of the euclidean gravitational action @xcite and the cosmology debate of the tunneling vs no - boundary proposals @xcite .. Please generate the next two sentences of the article

thus , a recently suggested eqg density matrix of the universe @xcite is hardly believed to be a viable candidate for the initial state of the universe , even though it avoids the infrared catastrophe of small cosmological constant @xmath0 , generates an ensemble of quasi - thermal universes in the limited range of @xmath0 , and suggests a strong selection mechanism for the landscape of string vacua @xcite . here we want to give a brief overview of these results and also justify them by deriving from first principles of lorentzian quantum gravity applied to a microcanonical ensemble of closed cosmological models @xcite . in view of the peculiarities of spatially closed cosmology

Suppose that you have an abstract for a scientific paper: we study spatially periodic orbits for a coupled map lattice of sine circle maps with nearest neighbour coupling and periodic boundary conditions . the stability analysis for an arbitrary spatial period @xmath0 is carried out in terms of the independent variables of the problem and the stability matrix is reduced to a neat block diagonal form . for a lattice of size @xmath1 , we show that the largest eigenvalue for the stability matrix of size @xmath2 is the same as that for the basic spatial period @xmath0 matrix of size @xmath3 . thus the analysis for a @xmath1 lattice case can be reduced to that for a @xmath0 lattice case . we illustrate this explicitly for a spatial period two case . our formalism is general and can be extended to any coupled map lattice . we also obtain the stability regions of solutions which have the same spatial and temporal period numerically . our analysis shows that such regions form a set of arnold tongues in the @xmath4 space . the tongues corresponding to higher spatial periods are contained within the tongues seen in the temporally periodic spatial period one or synchronised case . we find an interesting new bifurcation wherein the the spatially synchronised and temporal period one solution undergoes a bifurcation to a spatio - temporal period two travelling wave solution . the edges of the stability interval of this solution are analytically obtained . * spatially periodic orbits in coupled sine circle maps * nandini chatterjee@xmath5 and neelima gupte@xmath6 @xmath5 department of physics , university of pune , pune 411007 , india . @xmath6 department of physics , indian institute of technology , madras madras 600036 , india . pacs number(s ) : 05.45 . + b it is well known that systems with many degrees of freedom show complex spatio - temporal behaviour @xcite . this behaviour may lead to highly structured self - organising patterns , or may be highly incoherent in the spatial or temporal sense . studies of systems.... And you have already written the first three sentences of the full article: the specific model under study , is a 1-dimensional coupled map lattice of sine - circle maps with nearest neighbour diffusive symmetric normalized coupling ( also called future coupled laplacian coupling ) and periodic boundary conditions @xcite . this is defined by the evolution equation @xmath19 where @xmath20 is the angular variable associated with the @xmath21th lattice site , at time @xmath22 and lies between @xmath23 and @xmath24 , @xmath25 is the strength of the nonlinearity , @xmath26 is the period of the system for @xmath27 and @xmath18 which lies between 0 and 1 is the strength of the coupling parameter . we study the system for the homogeneous parameter case where @xmath26 and @xmath25 take the same value at each lattice site .. Please generate the next two sentences of the article

however the framework we develop can be used to study inhomogenous systems where the values of @xmath26 and @xmath25 depend on the lattice site . we consider a lattice of @xmath1 sites and are interested in periodic solutions such that @xmath0 is the basic spatial period and @xmath7 is the number of copies of this basic spatial period .

Suppose that you have an abstract for a scientific paper: features of anisotropic collective flow and spectral temperatures have been determined for @xmath0 hyperons emitted from c + c collisions , at incident momentum of @xmath1 , measured using the propane bubble chamber of jinr at dubna . moreover , characteristics of protons and of negative pions , emitted from those collisions , have been determined and provided for comparison . the directed and elliptic flows of @xmath0s both agree in sign with the corresponding flows of protons . parameters of the directed and elliptic flows for @xmath0s agree further , within errors , with the corresponding parameters for the co - produced protons . this contrasts an earlier finding by the e895 collaboration of the directed flow being significantly weaker for @xmath0s than protons , in the much heavier au + au system , at comparable incident momentum . particle spectral temperatures in the c + c collisions have been determined focusing independently on either center - of - mass energy , transverse energy or transverse momentum distributions . for either protons or negative pions , the temperatures were found to be approximately the same , no matter whether the emission of those particles was associated with @xmath0 production or not . results of the measurements have been compared to the results of simulations within the quark - gluon string model . . And you have already written the first three sentences of the full article: produced strange particles represent important probes of high - density nuclear matter formed in relativistic heavy - ion collisions . thus , because of the production thresholds , strangeness needs to be generated within early stages of a collision . due to their longer mean free path , the strange particles are additionally likely to leave the colliding system earlier than other hadrons .. Please generate the next two sentences of the article

given the necessary contributions of the early high - density stages of a collision , to the strangeness production , the yields of strange particles have been linked theoretically to the nuclear equation of state of dense matter @xcite and to the in - medium modifications of particle masses @xcite . in drawing concrete conclusions on the equation of state from yield data , comparison of the results from light c + c and heavy au + au systems turned out to be of crucial importance @xcite .

Suppose that you have an abstract for a scientific paper: this article is devoted to the analysis of a monte - carlo method to approximate effective coefficients in stochastic homogenization of discrete elliptic equations . we consider the case of independent and identically distributed coefficients , and adopt the point of view of the random walk in a random environment . given some final time @xmath0 , a natural approximation of the homogenized coefficients is given by the empirical average of the final squared positions rescaled by @xmath1 of @xmath2 independent random walks in @xmath2 independent environments . relying on a new quantitative version of kipnis - varadhan s theorem ( which is of independent interest ) , we first give a sharp estimate of the error between the homogenized coefficients and the expectation of the rescaled final position of the random walk in terms of @xmath1 . we then complete the error analysis by quantifying the fluctuations of the empirical average in terms of @xmath2 and @xmath1 , and prove a large - deviation estimate . compared to other numerical strategies , this monte - carlo approach has the advantage to be dimension - independent in terms of convergence rate and computational cost . * keywords : * random walk , random environment , stochastic homogenization , effective coefficients , monte - carlo method , quantitative estimates . * 2010 mathematics subject classification : * 35b27 , 60k37 , 60h25 , 65c05 , 60h35 , 60g50 . . And you have already written the first three sentences of the full article: this article is part of a larger program , which consists in devising and quantitatively analyzing numerical methods to approximate effective coefficients in stochastic homogenization of linear elliptic equations . more precisely we tackle here the case of a discrete elliptic equation with independent and identically distributed coefficients ( see however the end of this introduction for more general statistics ) , and present and fully analyze an approximation procedure based on a monte - carlo method . a first possibility to approximate effective coefficients is to directly solve the so - called corrector equation . in this approach , a first step towards the derivation of error estimates is a quantification of the qualitative results proved by knnemann @xcite ( and inspired by papanicolaou and varadhan s treatment of the continuous case @xcite ) and kozlov @xcite . in the stochastic case , such an equation is posed on the whole @xmath3 , and we need to localize it on a bounded domain , say the hypercube @xmath4 of side @xmath5 . as shown in a series of papers by otto and the first author @xcite , and the first author @xcite , there are three contributions to the @xmath6-error in probability between the true homogenized coefficients and its approximation .. Please generate the next two sentences of the article

the dominant error in small dimensions takes the form of a variance : it measures the fact that the approximation of the homogenized coefficients by the average of the energy density of the corrector on a box @xmath4 fluctuates . this error decays at the rate of the central limit theorem @xmath7 in any dimension ( with a logarithmic correction for @xmath8 ) .

Suppose that you have an abstract for a scientific paper: we study the quantum conformal gravity whose dynamics is governed by a single dimensionless gravitational coupling with negative beta function . since the euler term is not dynamical classically , the constant in front of it is not an independent coupling . quantum mechanically , however , it induces the riegert conformal - factor dynamics with brst conformal symmetry representing background free nature . in this paper , we propose how to handle the euler term systematically , incorporating such dynamics on the basis of renormalization group analysis using dimensional regularization . as a nontrivial test of renormalization , we explicitly calculate the three - loop anomalous dimension of the cosmological constant operator and show that it agrees with the exact expression derived using the brst conformal symmetry . the physical significance to inflation and the cosmic microwave background is also discussed . july 2014 ken - ji hamada _ institute of particle and nuclear studies , kek , tsukuba 305 - 0801 , japan _ + and + _ department of particle and nuclear physics , the graduate university for advanced studies ( sokendai ) , tsukuba 305 - 0801 , japan _ . And you have already written the first three sentences of the full article: recent observations of cosmic microwave background ( cmb ) anisotropies by various groups @xcite suggest that the universe began to expand at very high energies beyond the planck scale . there , spacetime would be totally fluctuating according to the laws of quantum mechanics . thus , quantum gravity is now becoming an indispensable theory to describe the dynamics of the early universe . on the other hand , at first glance. Please generate the next two sentences of the article

, it seems to be contradictory that we trace the origin of primordial fluctuations to quantum gravity , because the observations show that scalar fluctuations are more significant than tensor ones in the early universe . this implies that if we wish to explain such fluctuations using quantum gravity only without adding a phenomenological scalar field , we have to construct a model whose physical states become scalarlike in the uv limit . in order to resolve this problem

Suppose that you have an abstract for a scientific paper: the euclidean tsp with neighborhoods ( tspn ) is the following problem : given a set @xmath0 of @xmath1 regions ( subsets of @xmath2 ) , find a shortest tour that visits at least one point from each region . we study the special cases of disjoint , connected , @xmath3-fat regions ( i.e. , every region @xmath4 contains a disk of diameter @xmath5 ) and disjoint unit disks . for the latter , dumitrescu and mitchell @xcite proposed an algorithm based on mitchell s guillotine subdivision approach for the euclidean tsp @xcite , and claimed it to be a ptas . however , their proof contains a severe gap , which we will close in the following . bodlaender et al . @xcite remark that their techniques for the minimum corridor connection problem based on arora s ptas for tsp @xcite carry over to the tspn and yield an alternative ptas for this problem . for disjoint connected @xmath3-fat regions of varying size , mitchell @xcite proposed a slightly different ptas candidate . we will expose several further problems and gaps in this approach . some of them we can close , but overall , for @xmath3-fat regions , the existence of a ptas for the tspn remains open . _ keywords : _ tsp with neighbourhoods , approximation scheme , guillotine subdivision , travelling salesman problem . And you have already written the first three sentences of the full article: the euclidean tsp with neighborhoods ( tspn ) is the following problem : given a set @xmath0 of @xmath1 regions ( subsets of @xmath2 ) , find a shortest tour that visits at least one point from each region . even for disjoint or connected regions , the tspn does not admit a ptas unless @xmath6 @xcite . aiming for a ptas under additional restrictions on the input , @xcite and @xcite require connected and disjoint regions , and both introduce a notion of @xmath3-fatness . [ def : afat - mit ] a region @xmath4 of points in the plane is * @xmath7-fat * , if it contains a disk of diameter @xmath8 .. Please generate the next two sentences of the article

[ def : afat - elb ] a region @xmath4 in the plane is * @xmath7-fat@xmath9 * , if for every disk @xmath10 , such that the center of @xmath10 is contained in @xmath4 but @xmath10 does not fully contain @xmath4 , the area of the intersection @xmath11 is at least @xmath12 times the area of @xmath10 . for @xmath3-fat@xmath13 regions , chan and elbassioni @xcite developed a quasi - polynomial time approximation scheme ( even for a more general notion of fatness and in more general metric spaces ) .

Suppose that you have an abstract for a scientific paper: a veritable zoo of different knots is seen in the ensemble of looped polymer chains , whether created computationally or observed in vitro . at short loop lengths , the spectrum of knots is dominated by the trivial knot ( unknot ) . the fractional abundance of this topological state in the ensemble of all conformations of the loop of @xmath0 segments follows a decaying exponential form , @xmath1 , where @xmath2 marks the crossover from a mostly unknotted ( ie topologically simple ) to a mostly knotted ( ie topologically complex ) ensemble . in the present work we use computational simulation to look closer into the variation of @xmath2 for a variety of polymer models . among models examined , @xmath2 is smallest ( about @xmath3 ) for the model with all segments of the same length , it is somewhat larger ( @xmath4 ) for gaussian distributed segments , and can be very large ( up to many thousands ) when the segment length distribution has a fat power law tail . . And you have already written the first three sentences of the full article: of interest to anglers seeking to fill their creels and children seeking to fasten their shoes , a wide audience has found knots compelling from time immemorial . in the scientific community , knots have been featured in initial formulations of the nature of atoms , @xcite ( see a popular historical account in @xcite ) , the formulation of certain path integrals , @xcite , and also in quantitative biology , where knots have been observed in , @xcite , and tied into , dna , @xcite , where the space of knots is biologically created and manipulated @xcite . knots also have been observed occasionally in proteins , @xcite .. Please generate the next two sentences of the article

historically , the classification of knots and study of knot invariants were the first subjects of knot theory @xcite , and this remains in the center of attention among knot theorists of mathematical orientation @xcite . another fundamental aspect of knot theory is that of knot entropy .

Suppose that you have an abstract for a scientific paper: a new approach to the generalised brownian motion introduced by m. boejko and r. speicher is described , based on symmetry rather than deformation . the symmetrisation principle is provided by joyal s notions of tensorial and combinatorial species . any such species @xmath0 gives rise to an endofunctor @xmath1 of the category of hilbert spaces with contractions . a generalised brownian motion is an algebra of creation and annihilation operators acting on @xmath2 for arbitrary hilbert spaces @xmath3 and having a prescription for the calculation of vacuum expectations in terms of a function @xmath4 on pair partitions . the positivity is encoded by a @xmath5-semigroup of `` broken pair partitions '' whose representation space with respect to @xmath4 is @xmath0 . the existence of the second quantisation as functor @xmath6 from hilbert spaces to noncommutative probability spaces is proved to be equivalent to the multiplicative property of the function @xmath4 . for a certain one parameter interpolation between the fermionic and the free brownian motion it is shown that the `` field algebras '' @xmath7 are type @xmath8 factors when @xmath9 is infinite dimensional . mathematisch instituut + katholieke universiteit nijmegen + toernooiveld 1 , 6526 ed nijmegen + the netherlands + fax:+31 24 3652140 . And you have already written the first three sentences of the full article: in non - commutative probability theory one is interested in finding generalisations of classical probabilistic concepts such as independence and processes with independent stationary increments . motivated by a central limit theorem result and by the analogy with classical brownian motion , m. boejko and r. speicher proposed in @xcite a class of operator algebras called `` generalised brownian motions '' and investigated an example of interpolation between the classical @xcite and the free motion of voiculescu @xcite . a better known interpolation is provided by the `` @xmath10-deformed commutation relations '' @xcite . such an operator algebra is obtained by performing the gns representation of the free tensor algebra @xmath11 over an arbitrary infinite dimensional real hilbert space @xmath9 , with respect to a `` gaussian state '' @xmath12 defined by the following `` pairing prescription '' : @xmath13 where @xmath14 and the sum runs over all pair partitions of the ordered set @xmath15 .. Please generate the next two sentences of the article

the functional is uniquely determined by the complex valued function @xmath4 on pair partitions . classical brownian motion is obtained by taking @xmath16 and @xmath17 with the constant function @xmath18 on all pair partitions ; the free brownian motion @xcite requires @xmath4 to be 0 on crossing partitions and 1 on non - crossing partitions .

Suppose that you have an abstract for a scientific paper: we study a physical system of @xmath0 interacting particles in @xmath1 , @xmath2 , subject to pair repulsion and confined by an external field . we establish a large deviations principle for their empirical distribution as @xmath0 tends to infinity . in the case of riesz interaction , including coulomb interaction in arbitrary dimension @xmath3 , the rate function is strictly convex and admits a unique minimum , the equilibrium measure , characterized via its potential . it follows that almost surely , the empirical distribution of the particles tends to this equilibrium measure as @xmath0 tends to infinity . in the more specific case of coulomb interaction in dimension @xmath3 , and when the external field is a convex or increasing function of the radius , then the equilibrium measure is supported in a ring . with a quadratic external field , the equilibrium measure is uniform on a ball . , . And you have already written the first three sentences of the full article: we study in this work a physical system of @xmath0 particles at positions @xmath4 , @xmath2 , with identical `` charge '' @xmath5 , subject to a confining potential @xmath6 coming from an external field and acting on each particle , and to an interaction potential @xmath7 $ ] acting on each pair of particles . the function @xmath8 is finite outside the diagonal and symmetric : for all @xmath9 with @xmath10 , we have @xmath11 . the energy @xmath12 of the configuration @xmath13 takes the form @xmath14\\[-8pt ] & & \qquad = \frac{1}{n}\sum_{i=1}^nv(x_i)+\frac{1}{n^2}\sum_{i < j}w(x_i , x_j)\nonumber \\ & & \qquad = \int v(x ) \,d\mu_n(x)+\frac{1}{2}\int\!\!\!\int _ { \neq } w(x , y ) \,d\mu_n(x ) \,d\mu_n(y),\nonumber\end{aligned}\ ] ] where @xmath15 is the empirical measure of the particles , and where the subscript `` @xmath16 '' indicates that the double integral is off - diagonal . the energy @xmath17 is a quadratic form functional in the variable @xmath18 . from now on , and unless otherwise stated , we denote by @xmath19 the euclidean norm of @xmath1 , and we make the following additional assumptions : the function @xmath20 $ ] is continuous on @xmath21 , symmetric , takes finite values on @xmath22 and satisfies the following integrability condition : for all compact subset @xmath23 , the function @xmath24 is locally lebesgue - integrable on @xmath25 .. Please generate the next two sentences of the article

the function @xmath26 is continuous and such that@xmath27 and @xmath28 there exist constants @xmath29 and @xmath30 such that for every , @xmath31 ( this must be understood as `` @xmath32 dominates @xmath8 at infinity . '' ) let @xmath33 be a sequence of positive real numbers such that @xmath34 as . under , there exists an integer @xmath35 depending on @xmath36 such that for any @xmath37 , we have @xmath38 so that we can define the boltzmann gibbs probability measure @xmath39 on @xmath40 by @xmath41 the law @xmath39 is the equilibrium distribution of a system of @xmath0 interacting brownian particles in @xmath1 , at inverse temperature @xmath42 , with equal individual `` charge '' @xmath43 , subject to a confining potential @xmath32 acting on each particle , and to an interaction potential @xmath8 acting on each pair of particles ; see section [ ssssde ] . note that for , the quantity @xmath44 can also be interpreted as the distribution of a system of @xmath0 particles living in @xmath1 , with unit `` charge , '' subject to a confining potential @xmath45 acting on each particle , and to an interaction potential @xmath8 acting on each pair of particles . our work is motivated by the following physical control problem : given the ( internal ) interaction potential @xmath8 , for instance , a coulomb potential , a target probability measure @xmath46 on @xmath1 , for instance , the uniform law on the unit ball , and a cooling scheme @xmath34 , for instance , @xmath47 , can we tune the ( external ) confinement potential @xmath32 ( associated to an external confinement field ) such that @xmath48 as @xmath49 ? in this direction , we provide some partial answers in theorems [ thldp ] and [ thriesz ] , corollaries [ cocoulomb ] and [ coprescription ] below .

Suppose that you have an abstract for a scientific paper: the production of chargino - neutralino pairs and their subsequent leptonic decays is one of the most promising supersymmetry ( susy ) signatures at the tevatron @xmath0 collider . we present here the most recent results on the search for the three - lepton and missing - transverse - energy susy signature using data collected with the cdf ii detector . the results are interpreted within the minimal supergravity ( msugra ) scenario . . And you have already written the first three sentences of the full article: in the search for new phenomena , one well - motivated extension to the standard model ( sm ) is supersymmetry ( susy ) . susy particles ( sparticles ) contribute to the higgs mass squared with opposite sign relative to the contributions of sm particles , and thus protect the weak mass scale , @xmath1 , from divergences . susy is a broken symmetry since the sparticles obviously do not have the same mass as their sm partners , but the breaking must be ` soft ' to allow the divergence canceling to remain effective . if @xmath2 parity is conserved , where @xmath3 is baryon number , @xmath4 is lepton number , and @xmath5 is spin . ] , the lightest susy particle ( lsp ) is absolutely stable and provides a viable candidate for cosmological dark matter @xcite .. Please generate the next two sentences of the article

we use as a reference the msugra model of susy breaking . this model has the virtue of containing only five free parameters to specify .

Suppose that you have an abstract for a scientific paper: we test the accuracy of different models of the attenuation of light due to resonant scattering by intergalactic neutral hydrogen by comparing their predictions of the evolution of the mean cosmic flux decrement , @xmath0 , to measurements of this quantity based on observations . to this end , we use data available in the literature and our own measurements of the cosmic flux decrement for 25 quasars in the redshift range @xmath1 taken from the sdss data release 5 . in order to perform the measurements of @xmath0 , we fit a power - law to the continuum redward of the ly@xmath2 emission line , and extrapolate this fit to region blueward of it , where the flux is severely affected by absorption due to intervening hi absorbers . we compute , using numerical simulations , the redshift evolution of @xmath0 accounting for the presence of ly@xmath2 forest absorbers and lyman limit systems randomly distributed along the line - of - sight , and compute its intrinsic scatter at the 1- , 2- , and @xmath3 level due to fluctuations in the absorber properties ( column density , doppler parameter , redshift ) along different lines - of - sight . the numerical simulations consist of monte carlo realizations of distributions of the absorber properties constrained from observations . the results from the models considered here confirm our theoretical expectation that the distribution of @xmath0 at any given redshift be well described by a lognormal distribution function . this implies that the effective optical depth , usually defined as the negative logarithm of the average flux , 1 - @xmath0 , is very accurately gaussian distributed , in contrast to previous studies . this result is independent to the form of the input distribution functions , and rather insensitive to the presence of high - column density absorbers , such as the lyman limit systems . by comparing our and previous measurements of @xmath0 to the outcomes of our simulations , we find an excellent agreement between the observations and the.... And you have already written the first three sentences of the full article: since the introduction of the gunn - peterson ( gp ) test by @xcite , a detailed knowledge about the physical state of the intergalactic medium ( igm ) has been gained from the study of the absorption features identified in the spectra of quasi - stellar objects ( qsos ) at restframe wavelengths @xmath4 , which are now known to be mainly due to resonant scattering by intergalactic neutral hydrogen randomly distributed along the line - of - sight , as first proposed by @xcite . for instance , the null result in the search for a gp trough has been used to rule out the existence of a hot intercloud medium ( icm ) @xcite , which was thought to confine by pressure the ly@xmath2 clouds @xcite . as a result of detailed analyses of the line statistics of the absorbing material , a wealth of information on its clustering ( see _ e.g. _ * ? ? ? * ) , in particular the existence of voids ( _ e.g. _ * ? ? ? * ; * ? ? ? * ; * ? ? ? * ) , and the evolution of its number densities , column densities , and doppler parameter with redshift ( _ e.g. _ * ? ? ? * ) has accumulated over the past years .. Please generate the next two sentences of the article

these results , in combination with the use of state - of - the - art numerical simulations of structure formation based on the currently accepted paradigm of the concordance cosmology @xcite , show that the features seen in absorption against bright background sources arise when the line - of - sight intersects the structures that naturally emerge and evolve with time under the influence of gravitational attraction . different types of structures such as the filaments present in the _ cosmic web _ , galactic haloes , and even the discs of primeval galaxies , give rise to distinct absorption features attributed to entities known historically as ly@xmath2 forest clouds , lyman limit systems ( llss ) , and damped ly@xmath2 absorbers ( dlas ) ( see _ e.g. _ * ? ? ?

Suppose that you have an abstract for a scientific paper: we study the origin of attracting phenomena in the ray dynamics of coupled optical microcavities . to this end we investigate a combined map that is composed of standard and linear map , and a selection rule that defines when which map has to be used . we find that this system shows attracting dynamics , leading exactly to a quasiattractor , due to collapse of phase space . for coupled dielectric disks , we derive the corresponding mapping based on a ray model with deterministic selection rule and study the quasiattractor obtained from it . we also discuss a generalized poincar surface of section at dielectric interfaces . . And you have already written the first three sentences of the full article: an attractor in classical dynamics is , colloquially speaking , a ( invariant ) set of points to which all trajectories starting in its neighborhood ( more precisely , its basin of attraction ) converge . more precisely , an attractor can be defined as a closed set @xmath0 with the following properties @xcite . first , @xmath0 is an invariant set : any trajectory @xmath1 that starts in @xmath0 stays in @xmath0 for all time .. Please generate the next two sentences of the article

secondly , @xmath0 attracts an open set of initial conditions : there is an open set @xmath2 containing @xmath0 such that if @xmath3 , then the distance from @xmath1 to @xmath0 tends to zero as @xmath4 . this means that @xmath0 attracts all trajectories that start sufficiently close to it .

Suppose that you have an abstract for a scientific paper: using self - consistent magnetohydrodynamic ( mhd ) simulations , we explore the hypothesis that nonlinear mhd waves dominate the internal dynamics of galactic molecular clouds . our models employ an isothermal equation of state and allow for self - gravity . we adopt `` slab - symmetry , '' which permits motions @xmath0 and fields @xmath1 perpendicular to the mean field , but permits gradients only parallel to the mean field . this is the simplest possible geometry that relies on waves to inhibit gravitational collapse along the mean field . in our simulations , the speed @xmath2 exceeds the sound speed @xmath3 by a factor @xmath4 , which is realistic for molecular clouds . we simulate the free decay of a spectrum of waves , with and without self - gravity . we also perform simulations with and without self - gravity that include small - scale stochastic forcing , meant to model the mechanical energy input from stellar outflows . our major results are as follows : ( 1 ) we confirm that the pressure associated with fluctuating transverse fields can inhibit the mean - field collapse of clouds that are unstable by jeans s criterion . cloud support requires the energy in -like disturbances to remain comparable to the cloud s gravitational binding energy . ( 2 ) we characterize the turbulent energy spectrum and density structure in magnetically - dominated clouds . the perturbed magnetic and transverse kinetic energies are nearly in equipartition and far exceed the longitudinal kinetic energy . the turbulent spectrum evolves to a power - law shape , approximately @xmath5 with @xmath6 , i.e. approximately consistent with a `` linewidth - size '' relation @xmath7 . the simulations show large density contrasts , with high density regions confined in part by the pressure of the fluctuating magnetic field . ( 3 ) we evaluate the input power required to offset dissipation through shocks , as a function of @xmath8 , the velocity dispersion @xmath9 , and the characteristic scale @xmath10 of.... And you have already written the first three sentences of the full article: the internal dynamics of star - forming galactic molecular clouds is not yet understood . two central questions are ( 1 ) what prevents the clouds and their subcomponents from collapsing under their own weight ; and ( 2 ) what generates and controls the turbulent fluid velocities that broaden molecular lines far beyond the thermal speed @xmath3 ( e.g. @xcite ) . one model which has been proposed ( e. g. @xcite ) is that the clouds are comprised of clumps on essentially ballistic , collisionless orbits . however , while clouds are observed to be clumpy , the volume filling factor of clumps in the clouds @xmath16 ( e.g. @xcite ; @xcite ) implies a clump - clump collision time @xmath17 , which makes the clouds at most marginally collisionless over their lifetimes ( @xcite ) . the clumps are not themselves thermally supported , and they appear to have larger internal filling factors and smaller ratios of internal collision time to dynamical time .. Please generate the next two sentences of the article

although internal velocities may be generated by a cloud s self - gravity , purely hydrodynamic turbulence either clumpy or smooth can not in itself support a structure for longer than the effective collision time ( equal to the eddy - turnover time for a uniform fluid ) because it would dissipate in shocks ( see @xcite and references therein ) .

Suppose that you have an abstract for a scientific paper: it has been known for a long time that a large fraction of disc galaxies are lopsided . we simulate three different mechanisms that can induce lopsidedness : flyby interactions , gas accretion from cosmological filaments and ram pressure from the intergalactic medium . comparing the morphologies , hi spectrum , kinematics and @xmath0 fourier components , we find that all of these mechanisms can induce lopsidedness in galaxies , although in different degrees and with observable consequences . the timescale over which lopsidedness persists suggests that flybys can contribute to @xmath1 per cent of lopsided galaxies . we focus our detailed comparison on the case of ngc 891 , a lopsided , edge - on galaxy with a nearby companion ( ugc 1807 ) . we find that the main properties of ngc 891 ( morphology , hi spectrum , rotation curve , existence of a gaseous filament pointing towards ugc 1807 ) favour a flyby event for the origin of lopsidedness in this galaxy . # 1/#1 methods : _ n_-body simulations - galaxies : kinematics and dynamics - galaxies : interactions - galaxies : individual : ngc 891 . And you have already written the first three sentences of the full article: a high fraction of disc galaxies are lopsided , i.e. their gas and/or stellar component extend further out on one side of the galaxy than on the other ( baldwin , lynden - bell & sancisi 1980 ; block et al . 1994 ; richter & sancisi 1994 ; rix & zaritsky 1995 ; schoenmakers , franx & de zeeuw 1997 ; zaritsky & rix 1997 ; matthews , van driel & gallagher 1998 ; haynes et al . 1998 ; swaters et al . 1999 ; bournaud et al . 2005 , hereafter b05 ; see sancisi et al .. Please generate the next two sentences of the article

2008 for a review ) . the gaseous component of the disc is particularly affected by this phenomenon . richter & sancisi ( 1994 ) show that the lopsidedness of a galaxy can be inferred from asymmetries in its global hi profile , and estimate , from the analysis of 1700 hi spectra , that @xmath2 per cent of disc galaxies are lopsided in the gaseous component .

Suppose that you have an abstract for a scientific paper: two sensitive _ chandra _ x - ray observations of the heavily - reddened galactic starburst cluster westerlund 1 in may and june 2005 detected a previously unknown x - ray pulsar ( cxo j164710.20@xmath0455217 ) . its slow 10.6 s pulsations , moderate x - ray temperature kt @xmath1 0.5 kev , and apparent lack of a massive companion tentatively suggest that it is an anomalous x - ray pulsar ( axp ) . an isothermal blackbody model yields an acceptable spectral fit but the inferred source radius is much less than that of a neutron star , a result that has also been found for other axps . we analyze the x - ray spectra with more complex models including a model that assumes the pulsar is a strongly magnetized neutron star ( `` magnetar '' ) with a light element atmosphere . we conclude that the observed x - ray emission can not be explained as global surface emission arising from the surface of a cooling neutron star or magnetar . the emission likely arises in one or more localized regions ( `` hot spots '' ) covering a small fraction of the surface . we discuss these new results in the context of both accretion and magnetar interpretations for the x - ray emission . . And you have already written the first three sentences of the full article: x - ray pulsars most commonly occur as members of binary systems and their primary energy source is believed to be accretion from a donor star onto the neutron star . however , about a half dozen x - ray pulsars have been identified over the past decade that do not show the telltale doppler shifts associated with orbital motion and have slow pulsation periods of @xmath1 6 - 12 s and similar x - ray properties . they are now known collectively as anomalous x - ray pulsars ( axps ) .. Please generate the next two sentences of the article

the apparent absence of a donor star , slow pulsation periods , and x - ray luminosity levels of axps suggest that their x - ray emission is not powered by binary accretion or rotational energy loss . two somewhat different pictures have emerged to explain the x - ray emission .

Suppose that you have an abstract for a scientific paper: let @xmath0 be a quadratic form of signature @xmath1 , @xmath2 a non - elementary discrete subgroup of @xmath3 and @xmath4 a non - zero vector with the orbit @xmath5 discrete . we introduce the notion of the @xmath2-skinning size @xmath6 of @xmath7 , and we compute an asymptotic formula ( as @xmath8 ) for the number of points in @xmath5 of norm at most @xmath9 , provided both the bowen - margulis - sullivan measure @xmath10 and the @xmath2-skinning size @xmath6 are finite . for @xmath2 geometrically finite , it is known that @xmath11 by sullivan and we give a criterion on the finiteness of @xmath6 : @xmath12 if and only if either @xmath13 or @xmath7 is not externally @xmath2-parabolic . we also prove new weighted equidistribution theorem for normal geodesic evolution of codimension one totally geodesic immersions . however the applicability of the basic result is not limited to geometrically finite groups we use these results to count circles in the circle packing @xmath14 of an ideal triangle of the hyperbolic plane @xmath15 made by repeatedly inscribing the largest circles into the triangular interstices . we obtain that the number of circles in @xmath14 of hyperbolic curvature at most @xmath9 is asymptotic to @xmath16 where @xmath17 is an absolute constant . . And you have already written the first three sentences of the full article: [ [ section ] ] let @xmath18 be a real quadratic form of signature @xmath1 for @xmath19 . for @xmath20 , consider the level set @xmath21 : @xmath22 the variety @xmath21 is a cone ( @xmath23 ) a one - sheeted hyperboloid ( @xmath24 ) or a two sheeted hyperboloid @xmath25 depending on the signature of @xmath26 . denote by @xmath27 the identity component of the special orthogonal group @xmath28 a discrete subgroup of a locally compact group with finite co - volume is called a lattice . for @xmath29 and a subgroup @xmath30 of @xmath27 , we denote by @xmath31 the stabilizer of @xmath32 in @xmath30 . [ drs ] let @xmath2 be a lattice in @xmath27 and @xmath4 a non - zero vector such that @xmath5 is discrete .. Please generate the next two sentences of the article

suppose that @xmath33 is a lattice in @xmath34 . then for any norm @xmath35 on @xmath36 , @xmath37 where @xmath38 and the volumes on @xmath39 and @xmath40 are computed with respect to invariant measures chosen compatibly .

Suppose that you have an abstract for a scientific paper: we study the situation where two point like mirrors are placed in the vacuum state of a scalar field in a two - dimensional spacetime . describing the scattering upon the mirrors by transmittivity and reflectivity functions obeying unitarity , causality and high frequency transparency conditions , we compute the fluctuations of the casimir forces exerted upon the two motionless mirrors . we use the linear response theory to derive the motional forces exerted upon one mirror when it moves or when the other one moves . we show that these forces may be resonantly enhanced at the frequencies corresponding to the cavity modes . we interpret them as the mechanical consequence of generation of squeezed fields . pacs : 03.65 - 42.50 - 12.20 . And you have already written the first three sentences of the full article: the vacuum fluctuations of the electromagnetic field manifest themselves through macroscopic casimir forces @xcite . these forces result from the radiation pressure exerted upon boundaries by the scattered fluctuations which depends upon the instantaneous and local value of the stress tensor . consequently , they are fluctuating quantities @xcite .. Please generate the next two sentences of the article

more precisely , the forces exerted upon the two mirrors of a fabry - perot cavity have to be considered as random variables . in the present paper , we compute the associated correlation functions . for the sake of simplicity , we study the situation where two point like mirrors are placed in the vacuum state of a scalar field in a two - dimensional ( 2d ) spacetime . as illustrated by the langevin theory of brownian motion @xcite , any fluctuating force has a long term cumulative effect .

Suppose that you have an abstract for a scientific paper: we generalize the derivation of dynamo coefficient @xmath0 of field ( 1999 ) to include the following two aspects : first , the de - correlation times of velocity field and magnetic field are different ; second , the magnetic prandtl number can be arbitrary . we find that the contributions of velocity field and magnetic field to the @xmath0 effect are not equal , but affected by their different statistical properties . in the limit of large kinetic reynolds number and large magnetic reynolds number , @xmath0-coefficient may not be small if the de - correlation times of velocity field and magnetic field are shorter than the eddy turn - over time of the mhd turbulence . we also show that under certain circumstances , for example if the kinetic helicity and current helicity are comparable , @xmath0 depends insensitively on magnetic prandtl number , while if either the kinetic helicity or the current helicity is dominated by the other one , a different magnetic prandtl number will significantly change the dynamo @xmath0 effect . # 1#1 * v * * the dependence of dynamo @xmath0-effect on reynolds numbers , magnetic prandtl number , and the statistics of mhd turbulence * + _ harvard - smithsonian center for astrophysics , cambridge , ma 02138 , u.s.a . + chou5@fas.harvard.edu_ . And you have already written the first three sentences of the full article: dynamo theory is an attempt to understand the process of magnetic field generation by self - inductive action in electrically conducting fluids . the theory has been used to explain the magnetic field generation in many celestial objects such as the sun , the earth and the galaxy . dynamo theory divides into a kinematic regime and a dynamic regime . in the kinematic regime , the velocity field. Please generate the next two sentences of the article

is prescribed , and dynamo theory studies the physics of magnetic field under the determined velocity field . in general , kinematic dynamo theory focuses solely on the mathematical solution of the induction equation , = ( ) + ^2 , where @xmath1 , @xmath2 are the velocity and magnetic field , respectively , and @xmath3 is the magnetic diffusivity . in the dynamic regime , the velocity field can be modified by the magnetic field , so that the dynamic dynamo theory must then consider both the induction equation and the momentum equation = -+ + ^2 - p + , where @xmath4 is the molecular viscosity , @xmath5 the total pressure , and @xmath6 the external forcing term .

Suppose that you have an abstract for a scientific paper: negative charge transfer @xmath0o@xmath1 oxides may undergo electronic metal insulator transitions ( mit ) concomitant with a dilation and contraction of nearly rigid octahedra . on both sides of the mit are in - phase or out - of - phase ( or both ) rotations of adjacent octahedra that buckle the @xmath2o@xmath2 bond angle away from 180@xmath3 . using density functional theory with the pbesol@xmath4 approach , we describe a novel octahedral engineering avenue to control the @xmath2 @xmath5 and o @xmath6 orbital polarization through enhancement of the @xmath2o@xmath7 rotation `` sense '' rather than solely through conventional changes to the @xmath2o bond lengths , _ i.e. _ crystal field distortions . using cafeo@xmath1 as a prototypical material , we show the flavor of the octahedral rotation pattern when combined with strain rotation coupling and thin film engineering strategies offers a promising avenue to fine tune orbital polarizations near electronic phase boundaries . = 1 . And you have already written the first three sentences of the full article: transition metal oxide ( tmo ) perovskites are known to be strongly correlated materials @xcite , whose properties are controlled by a complex interplay between geometric and electronic degrees of freedom . these are determined by considering the relative magnitude between various energy scales and interactions : the energy difference of the transition metal ( @xmath8 ) @xmath9 orbitals and the oxygen @xmath10 states , referred to as the charge transfer energy , and the strength of the on - site hubbard @xmath11 interaction of the @xmath9 electrons . the charge transfer energy is more important in tmo where low - energy excitations are of @xmath12-type , whereas the coulombic interaction , which localizes the electrons on the @xmath8-site , produces the insulating state in mott - hubbard systems @xcite .. Please generate the next two sentences of the article

the properties of correlated electrons of tmo are controlled in part by the relative occupancy of the different transition - metal @xmath9 orbitals@xcite . the relative @xmath9 orbital occupancy is largely determined by the crystal field experienced by the transition - metal cation ; this electrostatic field is the result of the 2@xmath10 electronic density of the coordinating oxygen ligands .

Suppose that you have an abstract for a scientific paper: we consider the problem of @xmath0-dimensional quantum gravity coupled to particles . working with the canonically reduced hamiltonian , we obtain its post - newtonian expansion for two identical particles . we quantize the @xmath0-dimensional newtonian system first , after which explicit energy corrections to second order in @xmath1 are obtained . we compute the perturbed wavefunctions and show that the particles are bound less tightly together than in the newtonian case . * perturbative quantum gravity coupled to particles in @xmath0-dimensions * + r.b . mann@xmath2 , m. b. young@xmath3 _ @xmath4 department of physics & astronomy , university of waterloo , + waterloo , ontario , n2l 3g1 , canada _ _ @xmath5 department of mathematics and statistics , queen s university at kingston , + kingston , ontario , k7l 3n6 , canada _ mann@avatar.uwaterloo.ca , 3my@qlink.queensu.ca . And you have already written the first three sentences of the full article: it is safe to say that we are still a considerable distance from a satisfactory theory of quantum gravity . pursuit of this goal is taking place on many fronts , one of which involves working in a two dimensional setting . this furnishes a dynamically simplified framework for developing methods that might be generalizable to higher dimensional quantum gravity , as well as yielding potential insight into quantization of a restricted number of degrees of freedom of such theories .. Please generate the next two sentences of the article

although the einstein vacuum field equations in two spacetime dimensions are trivial insofar as they are satisfied by any metric , it is nevertheless possible to construct dynamically interesting theories in this setting . this can be done by coupling a scalar field ( called the dilaton ) into the theory and including suitable matter sources , which typically include the dilaton itself .

Suppose that you have an abstract for a scientific paper: we show that the riccati form of the one - dimensional schrdinger equation can be reformulated in terms of two linear equations depending on an arbitrary function @xmath0 . when @xmath0 and the potential ( as for anharmonic oscillators ) are polynomials the solutions of these two equations are entire functions ( @xmath1 and @xmath2 ) and the zeroes of @xmath2 are identical to those of the wave function . requiring such a zero at a large but finite value of the argument yields the low energy eigenstates with exponentially small errors . approximate formulas for these errors are provided . we explain how to chose @xmath0 in order improve dramatically the numerical treatment . the method yields many significant digits with modest computer means . we discuss the extension of this method in the case of several variables . 220.5pc plus 4pt minus 3pt . And you have already written the first three sentences of the full article: quantum anharmonic oscillators appear in a wide variety of problems in molecular , nuclear or condensed matter physics . typically , anharmonic terms appear in expansions about a minimum of a potential , when ones tries to incorporate the non - linear features of the forces responsible for this equilibrium . the most celebrated example is the quartic anharmonic oscillator @xcite where a @xmath3 term is added to the usual harmonic hamiltonian .. Please generate the next two sentences of the article

introducing bilinear couplings among a set of such oscillators leads to a rich spectrum , for instance , multiphonon bound states in one - dimensional lattice models @xcite . more generally , one can think about the @xmath4 ( or higher powers of @xmath5 ) field theories in various dimensions as systems of coupled anharmonic oscillators . anharmonic terms can be treated perturbatively and the perturbative series can be represented by feynman diagrams .

Suppose that you have an abstract for a scientific paper: we study quantum communication through an anisotropic heisenberg xy chain in a transverse magnetic field . we find that for some time @xmath0 and anisotropy parameter @xmath1 , one can transfer a state with a relatively high fidelity . in the strong - field regime , the anisotropy does not significantly affect the fidelity while in the weak - field regime the affect is quite pronounced . the most interesting case is the the intermediate regime where the oscillation of the fidelity with time is low and the high - fidelity peaks are relatively broad . this would , in principle , allow for quantum communication in realistic circumstances . moreover , we calculate the purity , or tangle , as a measure of the entanglement between one spin and all the other spins in the chain and find that the stronger the anisotropy and exchange interaction , the more entanglement will be generated for a given time . quantum state transfer , entanglement 03.67hk,03.65ud,75.10jm . And you have already written the first three sentences of the full article: the transfer of a quantum state from one place to another is an important task in quantum information processing . a quantum state prepared by one party needs to be measured by another party at a distance . long distance communication between two parties , for example , in quantum key distribution @xcite , can be realized by means of photons . in this case. Please generate the next two sentences of the article

, photons have the advantage that they have an extremely small interaction with the environment and also travel long distances quickly through optical fibers or empty space . however , for short distance communication , such as connecting distinct quantum processors or registers inside a quantum computer @xcite , conditions and requirements are different @xcite .

Suppose that you have an abstract for a scientific paper: sky / cloud images captured by ground - based cameras ( a.k.a . whole sky imagers ) are increasingly used nowadays because of their applications in a number of fields , including climate modeling , weather prediction , renewable energy generation , and satellite communications . due to the wide variety of cloud types and lighting conditions in such images , accurate and robust segmentation of clouds is challenging . in this paper , we present a supervised segmentation framework for ground - based sky / cloud images based on a systematic analysis of different color spaces and components , using partial least squares ( pls ) regression . unlike other state - of - the - art methods , our proposed approach is entirely learning - based and does not require any manually - defined parameters . in addition , we release the * * s**ingapore * * w**hole sky * * im**aging * * seg**mentation database ( swimseg ) , a large database of annotated sky / cloud images , to the research community . shell : bare demo of ieeetran.cls for journals cloud segmentation , whole sky imager , partial least squares regression , swimseg database . And you have already written the first three sentences of the full article: have been extensively studied in the research community over the past few decades . the analysis of clouds and their features is important for a wide variety of applications . for example , it has been used for nowcasting to deliver accurate weather forecasts @xcite , rainfall and satellite precipitation estimates @xcite , in the study of contrails @xcite , and various other day - to - day meteorological applications @xcite .. Please generate the next two sentences of the article

yuan et al . have been investigating the clouds vertical structure @xcite and cloud attenuation for optimizing satellite links @xcite .

Suppose that you have an abstract for a scientific paper: we examine semi - bar visibility graphs in the plane and on a cylinder in which sightlines can pass through @xmath0 objects . we show every semi - bar @xmath0-visibility graph has a @xmath1-quasiplanar representation in the plane with vertices drawn as points in convex position and edges drawn as segments . we also show that the graphs having cylindrical semi - bar @xmath0-visibility representations with semi - bars of different lengths are the same as the @xmath2-degenerate graphs having edge - maximal @xmath1-quasiplanar representations in the plane with vertices drawn as points in convex position and edges drawn as segments . . And you have already written the first three sentences of the full article: bar visibility graphs are graphs for which vertices can be drawn as horizontal segments ( bars ) and edges can be drawn as vertical segments ( sightlines ) so that two bars are visible to each other if and only if there is a sightline which intersects them and no other bars . the study of bar visibility graphs was motivated in part by the problem of efficiently designing very large scale integration ( vlsi ) circuits @xcite . past research has shown how to represent planar graphs and plane triangular graphs as bar visibility graphs @xcite .. Please generate the next two sentences of the article

@xcite introduced a generalization of bar visibility graphs in which bars are able to see through at most @xmath0 other bars for some nonnegative integer @xmath0 . these graphs are known as bar @xmath0-visibility graphs .

Suppose that you have an abstract for a scientific paper: we discuss a method to constrain the intrinsic shapes of galaxy clusters by combining x - ray and sunyaev - zeldovich observations . the method is applied to a sample of @xmath0 x - ray selected clusters , with measured sunyaev - zeldovich temperature decrements . the sample turns out to be slightly biased , with strongly elongated clusters preferentially aligned along the line of sight . this result demonstrates that x - ray selected cluster samples may be affected by morphological and orientation effects even if a relatively high threshold signal - to - noise ratio is used to select the sample . a large majority of the clusters in our sample exhibit a marked triaxial structure ; the spherical hypothesis is strongly rejected for most sample members . cooling flow clusters do not show preferentially regular morphologies . we also show that identification of multiple gravitationally - lensed images , together with measurements of the sunyaev - zeldovich effect and x - ray surface brightness , can provide a simultaneous determination of the three - dimensional structure of a cluster , of the hubble constant , and the cosmological energy density parameters . . And you have already written the first three sentences of the full article: the intrinsic , three - dimensional ( hereafter 3-d ) shape of clusters of galaxies is an important cosmological probe . the structure of galaxy clusters is sensitive to the mass density in the universe , so knowledge of this structure can help in discriminating between different cosmological models . it has long been clear that the formation epoch of galaxy clusters strongly depends on the matter density parameter of the universe @xcite . the growth of structure in a high - matter - density universe is expected to continue to the present day , whereas in a low density universe the fraction of recently formed clusters , which are more likely to have substructure , is lower .. Please generate the next two sentences of the article

therefore , a sub - critical value of the density parameter @xmath1 favors clusters with steeper density profiles and rounder isodensity contours . less dramatically , a cosmological constant also delays the formation epoch of clusters , favoring the presence of structural irregularity @xcite .

Suppose that you have an abstract for a scientific paper: the fractional polylogarithms , depending on a complex parameter @xmath0 , are defined by a series which is analytic inside the unit disk . after an elementary conversion of the series into an integral presentation , we show that the fractional polylogarithms are multivalued analytic functions in the complex plane minus @xmath1 and @xmath2 . for non - integer values of @xmath0 , we prove the analytic continuation , compute the monodromy around @xmath1 and @xmath2 , give a mittag - leffler decomposition and compute the asymptotic behavior for large values of the complex variable . the fractional polylogarithms are building blocks of resurgent functions that are used in proving that certain power series associated with knotted objects are resurgent . this is explained in a separate publication @xcite . the motivic or physical interpretation of the monodromy of the fractional polylogarithms for non - integer values of @xmath0 is unknown to the authors . . And you have already written the first three sentences of the full article: for a complex number @xmath0 , let us define the _ @xmath0-polylogarithm _ function @xmath3 by the following series : @xmath4 which is absolutely convergent for @xmath5 . these functions appear in algebraic geometry , number theory , mathematical physics , applied mathematics and the theory of special functions .. Please generate the next two sentences of the article

since @xmath6 we really need to study @xmath3 for @xmath7 . for integer @xmath0 a lot is known about the @xmath0-polylogarithm . for example , @xmath8 , thus implies that for all @xmath9 , @xmath10 is a rational function with a single singularity at @xmath11 .

Suppose that you have an abstract for a scientific paper: we use a hadron resonance gas model to study the qcd phase diagram at nonzero temperature , baryon , isospin and strangeness chemical potentials . we determine the temperature of the transition from the hadronic phase to the quark gluon plasma phase using two different methods . we find that the critical temperatures derived in both methods are in very good agreement . we find that the critical surface has a small curvature . we also find that the critical temperature s dependence on the baryon chemical potential at zero isospin chemical potential is almost identical to its dependence on the isospin chemical potential at vanishing baryon chemical potential . this result , which holds when the chemical potentials are small , supports recent lattice simulation studies . finally , we find that at a given baryon chemical potential , the critical temperature is lowered as either the isospin or the strangeness chemical potential are increased . therefore , in order to lower the critical temperature , it might be useful to use different isotopes in heavy ion collision experiments . . And you have already written the first three sentences of the full article: the qcd phase diagram at nonzero temperature and baryon density has been the subject of numerous studies during the past few years @xcite . two regions of the phase diagram have been placed under special scrutiny . first , in the low temperature and high density domain , the ground state is believed to be a color superconductor @xcite .. Please generate the next two sentences of the article

there are numerous types of color superconducting phases that emerge as the baryon chemical potential increases @xcite . second , in the high temperature and low baryon density domain , there is a transition from the hadronic phase to the quark gluon plasma phase @xcite .

Suppose that you have an abstract for a scientific paper: the amplification of a surface electromagnetic wave by means of ultrarelativistic monoenergetic electron bunch running over the flat plasma surface in absence of a magnetic field is studied theoretically . it is shown that when the ratio of electron bunch number density to plasma electron number density multiplied by a powered to 5 relativity factor is much higher than 1 , i.e @xmath0 , the saturation field of the surface electromagnetic wave induced by trapping of bunch electrons gains the magnitude : @xmath1 and does not approache the surface electromagnetic wave front breakdown threshold in plasma . the surface electromagnetic wave saturation energy density in plasma can exceed the electron bunch energy density . here , we discuss the possibility of generation of superpower teraherz radiation on a basis of such scheme . . And you have already written the first three sentences of the full article: the surface electromagnetic waves ( sew ) on plasma surface and plasma - like media ( gaseous plasma , dielectric and conducting media , etc . ) attract special attention of researchers due to their unique properties . first of all , due to its high phase and group velocities close to light speed in vacuum at high media conductivity what makes them the most valuable in radiophysics @xcite . the sew are widely applied in physical electronics due to its high phase velocity leading to its uncomplicated generation by relativistic electron bunches and output from plasma .. Please generate the next two sentences of the article

+ below we discuss the problem of sew amplification with the help of electron bunch running over flat plasma surface . we consider the case of ultrarelativistic monoenergetic electron bunch which remains relativistic in the frame of reference of sew generated by this bunch compared to the works @xcite , where the bunches were nonrelativistic .

Suppose that you have an abstract for a scientific paper: we present a two - pronged approach to the formation of early - type galaxies , using a sample of 18 galaxies at @xmath0 from the hst / acs ultra deep field and grapes surveys : 1 ) we combine slitless low resolution spectroscopy from the grapes dataset with simple models of galaxy formation to explore their star formation histories . 2 ) we also perform an analysis of their surface brightness distribution with the unprecedented details provided by the acs superb angular resolution and photometric depth . our spectroscopic analysis reveals that their stellar populations are rather homogeneous in age and metallicity and formed at redshifts @xmath1 . evolving them passively , they become practically indistinguishable from ellipticals at @xmath2 0 . also , their isophotal shapes appear very similar to those observed for nearby ellipticals , in that the percentages of disky and boxy galaxies at @xmath3 1 are close to the values measured at @xmath2 0 . moreover , we find that the isophotal structure of @xmath4 1 early - type galaxies obeys the correlations already observed among nearby ellipticals , i.e. disky ellipticals have generally higher characteristic ellipticities , and boxy ellipticals have larger half - light radii and are brighter in the rest - frame b band . in this respect then , no significant structural differences are seen for ellipticals between @xmath2 0 and 1 . exception can be possibly made for the _ a@xmath5/a _ parameter , which is larger at @xmath3 1 than usually measured at @xmath2 0 . the _ a@xmath5/a _ parameter measures the deviations from a pure elliptical isophote which are not symmetric with respect to the galaxy center , as in the case of dust features and most notably of clumps . blue clumps have been detected in nearly 50@xmath6 of the @xmath4 1 early - type galaxies ; their photometry is suggestive of young star clusters or dwarf irregulars if they are assumed to be at the same redshift as their host galaxies . we speculate that these clumps may represent recent.... And you have already written the first three sentences of the full article: early - type galaxies form a remarkably homogeneous class of objects with a tight color - magnitude relation and a well defined fundamental plane . the small scatter in their colors ( bower , lucey & ellis 1992 , stanford , eisenhardt & dickinson 1998 , ) and mass - to - light ( m / l ) ratios ( cf . kelson et al . 2000 ) suggest that early - type galaxies formed the bulk of their stars at high redshift ( i.e. @xmath7 2 - 3 , van dokkum et al . 1998 , thomas et al . 2005 ) . since then. Please generate the next two sentences of the article

, early - type galaxies continued to grow in mass at different paces : the more massive objects ( @xmath8 10@xmath9 m@xmath10 ) appear to have increased their mass by less than 1@xmath6 since @xmath11 1 , while the less massive grew by 20 - 40@xmath6 ( cf . chen et al .

Suppose that you have an abstract for a scientific paper: laboratory experiments sensitive to the density dependence of the symmetry energy may place stringent constraints on the equation of state of neutron - rich matter and , thus , on the structure , dynamics , and composition of neutron stars . understanding the equation of state of neutron - rich matter is a central goal of nuclear physics that cuts across a variety of disciplines . in this contribution i focus on how laboratory experiments on neutron skins and on both pygmy and giant resonances can help us elucidate the structure of neutron stars . . And you have already written the first three sentences of the full article: one of the central questions framing the recent report by the committee on the assessment of and outlook for nuclear physics is _ `` how does subatomic matter organize itself?''_@xcite . remarkably , most of the fascinating phases that are predicted to emerge in this subatomic domain can not be probed under normal laboratory conditions . however , such novel states of matter become stable in the interior of neutron stars by virtue of the enormous gravitational fields .. Please generate the next two sentences of the article

the fascinating phases predicted to exist in the crust of neutron stars , such as coulomb crystals of neutron - rich nuclei and nuclear pasta , are within the purview of the facility for rare isotope beams ( frib ) which has as one of its science goals to provide an understanding of matter in the crust of neutron stars@xcite . frib is of relevance to neutron - star structure because at sub - saturation densities the uniform neutron - rich matter residing in the stellar core becomes unstable against cluster formation .

Suppose that you have an abstract for a scientific paper: we discuss possibilities to observe stochastic gravitational wave backgrounds produced by the electroweak phase transition in the early universe . once the first - order phase transition occurs , which is still predicted in a lot of theories beyond the standard model , collisions of nucleated vacuum bubbles and induced turbulent motions can become significant sources of the gravitational waves . detections of such gravitational wave backgrounds are expected to reveal the higgs sector physics . in particular , through pulsar timing experiments planned in square kilometre array ( ska ) under construction , we will be able to detect the gravitational wave in near future and distinguish particle physics models by comparing the theoretical predictions to the observations . kek - th-1735 + kek - cosmo-145 + arxiv:1405.4166 * detecting the relic gravitational wave from the electroweak phase transition at ska * yohei kikuta@xmath0 , kazunori kohri@xmath1 , eunseong so@xmath2 _ @xmath0department of particle and nuclear physics , graduate university for advanced studies _ _ ( sokendai ) , 1 - 1 oho , tsukuba , ibaraki 305 - 0801 , japan _ _ @xmath3kek theory center , institute of particle and nuclear studies , kek , _ _ 1 - 1 oho , tsukuba , ibaraki 305 - 0801 , japan _ . And you have already written the first three sentences of the full article: scientific research on gravitational wave is one of the most important subjects in physics . detecting gravitational wave directly is essential to verify general relativity in strong gravitational fields and explore high - energy particle physics phenomena in the early universe . in other words , physics of gravitational wave is attractive for both astrophysics and particle physics . due to a weakness of its interaction , the relic gravitational wave generated in the early universe. Please generate the next two sentences of the article

brings us information on the early universe for what it was . we observe it as stochastic gravitational wave backgrounds .

Suppose that you have an abstract for a scientific paper: we present observations of a sample of herbig aebe stars , as well as the fu orionis object v1057 cygni . our k - band ( @xmath0 ) observations from the palomar testbed interferometer ( pti ) used baselines of 110 m and 85 m , resulting in fringe spacings of @xmath1 and @xmath2 , respectively . fringes were obtained for the first time on v1057 cygni as well as v594 cas . additional measurements were made of mwc147 , while upper limits to visibility - squared are obtained for mwc297 , hd190073 , and mwc614 . these measurements are sensitive to the distribution of warm , circumstellar dust in these sources . if the circumstellar infrared emission comes from warm dust in a disk , the inclination of the disk to the line of sight implies that the observed interferometric visibilities should depend upon hour angle . surprisingly , the observations of millan - gabet , schloerb , & traub 2001 ( hereafter mst ) did not show significant variation with hour angle . however , limited sampling of angular frequencies on the sky was possible with the iota interferometer , motivating us to study a subset of their objects to further constrain these systems . . And you have already written the first three sentences of the full article: near - infrared , long baseline interferometry is sensitive to the distribution of dust around the nearest young stars on scales of the order of 1 au , and provides a powerful probe of models of disks and envelopes of such stars . the herbig ae - be stars are pre - main sequence , emission line objects that are the intermediate mass ( @xmath3 ) counterparts of t tauri stars ( hillenbrand _ et al . _ 1992 ) . we also observed the fu orionis object v1057 cyg , expected to have a strong disk signature due to the high accretion rate of such objects .. Please generate the next two sentences of the article

while the evolutionary status of the fu orionis objects remains unclear , they are believed to be t tauri stars undergoing an episode of greatly increased disk accretion , involving a brightening of @xmath4 magnitudes . v1057 cyg , whose outburst began in 1969 - 70 , is the only fu orionis object for which a pre - outburst spectrum is available , confirming its pre - main sequence nature ( grasdalen 1973 ) . until now ,

Suppose that you have an abstract for a scientific paper: we consider a sample of ten grbs with long lasting ( @xmath0 ) emission detected by fermi / lat and for which x - ray data around @xmath1day are also available . we assume that both the x - rays and the gev emission are produced by electrons accelerated at the external forward shock , and show that the x - ray and the gev fluxes lead to very different estimates of the initial kinetic energy of the blast wave . the energy estimated from gev is on average @xmath2 times larger than the one estimated from x - rays . we model the data ( accounting also for optical detections around @xmath1day , if available ) to unveil the reason for this discrepancy and find that good modelling within the forward shock model is always possible and leads to two possibilities : either the x - ray emitting electrons ( unlike the gev emitting electrons ) are in the slow cooling regime or ii ) the x - ray synchrotron flux is strongly suppressed by compton cooling , whereas , due to the klein - nishina suppression , this effect is much smaller at gev energies . in both cases the x - ray flux is no longer a robust proxy for the blast wave kinetic energy . on average , both cases require weak magnetic fields ( @xmath3 ) and relatively large isotropic kinetic blast wave energies @xmath4 corresponding to large lower limits on the collimated energies , in the range @xmath5 for an ism environment with @xmath6 and @xmath7 for a wind environment with @xmath8 . these energies are larger than those estimated from the x - ray flux alone , and imply smaller inferred values of the prompt efficiency mechanism , reducing the efficiency requirements on the still uncertain mechanism responsible for prompt emission . [ firstpage ] gamma - ray burst : general . And you have already written the first three sentences of the full article: gamma - ray bursts ( grbs ) have two phases . a short prompt phase in which the emission is predominantly in the sub - mev range is followed by a multi - wavelength afterglow that can be observed up to several years after the prompt emission . according to the generally accepted internal - external model @xcite the prompt emission is thought to originate from internal energy dissipation that takes place within the relativistic outflow . conversely , the afterglow radiation is thought to originate from interactions between the outflow and the external medium @xcite .. Please generate the next two sentences of the article

while the origin of the afterglow radiation has been understood in its general properties of synchrotron emission @xcite , the nature of the prompt radiation has not yet been completely unveiled . indeed , the nature of both the dissipation and the radiative mechanisms is still uncertain . the composition of the outflow , its initial energy content , and the processes at the origin of the prompt radiation are among the most relevant open issues in grb studies .

Suppose that you have an abstract for a scientific paper: the phase dependence of the cavity quantum dynamics in a driven equidistant three - level ladder - type system found in a quantum well structure with perpendicular transition dipoles is investigated in the good cavity limit . the pumping laser phases are directly transferred to the superposed amplitudes of the cavity - quantum - well interaction . their phase difference may be tuned in order to obtain destructive quantum interferences . therefore , the cavity field vanishes although the emitter continues to be pumped . . And you have already written the first three sentences of the full article: the confinement of quantum systems in a specific superposition of states may lead to various quantum processes . in the realm of quantum optics , a particular interest is focused on this type of phenomena , namely , quantum interference phenomena allow to explain and observe various quantum effects @xcite , while etanglement processes @xcite and shape - preserving localized light structures @xcite play a major role for the quantum computation and communication . a powerful tool in the control and manipulation of these effects originates from an additional degree of freedom of the system given by its phase dependence . for example. Please generate the next two sentences of the article

, quantum interference effects influence the collective fluorescence of a driven sample of emitters , which becomes sensitive to phase dependence . thus , the phase difference of the two lasers pumping a collection of three - level emitters may decrease and cancel its fluorescence when quantum interferences appear from a coherently driven source @xcite .

Suppose that you have an abstract for a scientific paper: the _ mars odyssey spacecraft carries two experiments which are capable of detecting cosmic gamma - ray bursts and soft gamma repeaters . since april 2001 they have detected over 275 bursts and , in conjunction with the other spacecraft of the interplanetary network , localized many of them rapidly and precisely enough to allow sensitive multi - wavelength counterpart searches . we present the _ mars odyssey mission and describe the burst capabilities of the two experiments in detail . we explain how the spacecraft timing and ephemeris have been verified in - flight using bursts from objects whose precise positions are known by other means . finally , we show several examples of localizations and discuss future plans for the _ odyssey mission and the network as a whole . _ _ _ . And you have already written the first three sentences of the full article: interplanetary networks ( ipns ) have played an important role in the studies of both cosmic gamma - ray bursts ( grbs ) and soft gamma repeaters ( sgrs ) for over two decades . indeed , until the launch of _ bepposax in 1996 , the only way to derive arcminute positions for these objects was by comparing their arrival times at distant spacecraft . the current ( third ) ipn was formed when the _ ulysses spacecraft was launched in 1990 . over 25 spacecraft have participated in the ipn since then , and the latest interplanetary mission to join the network is _ mars odyssey . it seems fitting that this spacecraft should belong to the ipn , since `` odyssey '' and `` ulysses '' both refer to the same saga of distant voyages .. Please generate the next two sentences of the article

today , the ipn comprises the _ ulysses , konus - wind , ramaty high energy solar spectroscopic imager ( rhessi ) _ , high energy transient explorer ( hete ) _ , swift , and _ mars odyssey ( mo ) missions and experiments , and , with a detection rate of 200 events / year , is responsible for most grb and sgr detections and localizations . as a distant point in the network , mo plays a crucial role : without it , only localizations to annuli or large error boxes would be possible . the triangulation , or arrival - time analysis method for localizing bursts has been presented elsewhere ( hurley et al .

Suppose that you have an abstract for a scientific paper: we present our recently developed _ galcon _ approach to hydrodynamical cosmological simulations of galaxy clusters - a subgrid model added to the _ enzo _ adaptive mesh refinement code - which is capable of tracking galaxies within the cluster potential and following the feedback of their main baryonic processes . galcons are physically extended galactic constructs within which baryonic processes are modeled analytically . by identifying galaxy halos and initializing galcons at high redshift ( @xmath0 , well before most clusters virialize ) , we are able to follow the evolution of star formation , galactic winds , and ram - pressure stripping of interstellar media , along with their associated mass , metals and energy feedback into intracluster ( ic ) gas , which are deposited through a well - resolved spherical interface layer . our approach is fully described and all results from initial simulations with the enhanced _ enzo - galcon _ code are presented . with a galactic star formation rate derived from the observed cosmic star formation density , our galcon simulation better reproduces the observed properties of ic gas , including the density , temperature , metallicity , and entropy profiles . by following the impact of a large number of galaxies on ic gas we explicitly demonstrate the advantages of this approach in producing a lower stellar fraction , a larger gas core radius , an isothermal temperature profile in the central cluster region , and a flatter metallicity gradient than in a standard simulation . * accepted for publication in the astrophysical journal . And you have already written the first three sentences of the full article: hydrodynamical simulations of galaxy clusters , incorporating semi - analytic models for star formation and galactic feedback processes , show an appreciable level of inconsistency with observational results . this is particularly apparent in the simulated properties of intracluster ( ic ) gas - temperature , metallicity and entropy profiles - and the stellar mass density at high redshift ( see the review by borgani et al . 2008 , and references therein ) . statistical properties of clusters , such as x - ray luminosity - temperature , entropy - temperature , and mass - temperature relations , seem also to be discrepant when compared with high - precision optical and x - ray observations ( e.g. , kay et al . 2007 , nagai et al .. Please generate the next two sentences of the article

2007 , tornatore et al . 2007 , kapferer et al . 2007

Suppose that you have an abstract for a scientific paper: vlt[multiblock footnote omitted ] spectroscopic observations of -excess objects in the field of the clumpy radio galaxy 1138262 at @xmath0 have led to the discovery of 14 galaxies and one qso at approximately the same distance as the radio galaxy . all galaxies have redshifts in the range 2.16@xmath10.02 , centered around the redshift of the radio galaxy , and are within a projected physical distance of 1.5 mpc from it . the velocity distribution suggests that there are two galaxy subgroups having velocity dispersions of @xmath2 km s@xmath3 and @xmath4 km s@xmath3 and a relative velocity of 1800 km s@xmath3 . if these are virialized structures , the estimated dynamical masses for the subgroups are @xmath59 and @xmath53 @xmath6 10@xmath7 m@xmath8 respectively , implying a total mass for the structure of more than 10@xmath9 m@xmath8 . the new observations , together with previous results , suggest that the structure of galaxies around 1138262 is likely to be a forming cluster . . And you have already written the first three sentences of the full article: one of the most intriguing questions in modern astrophysics concerns the formation of large scale structure in the early universe ( e.g. bahcall 1997 ) . although various scenarios have been developed within the context of modern cosmological models , the epoch and mechanism of the formation of galaxy clusters are still open questions . + despite several tentative identifications of clusters and groups at high redshift ( e.g. keel 1999 ; campos et al .. Please generate the next two sentences of the article

1999 ; pascarelle 1998 ) , there is yet no solid identification of collapsed clusters or groups at redshifts above 1.5 . recently steidel ( 2000 ) reported the discovery of a significant overdensity of galaxies at @xmath10 and pointed out its possible association with a quasar .