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7,700 | Suppose that you have an abstract for a scientific paper: we report the source size distribution , as measured by alma millimetric continuum imaging , of a sample of 13 aztec - selected submillimeter galaxies ( smgs ) at @xmath06 .
their infrared luminosities and star - formation rates ( sfr ) are @xmath12@xmath2l@xmath3 and @xmath4600m@xmath3 yr@xmath5 , respectively
. the sizes of these smgs range from [email protected] to [email protected] , with a median of [email protected]@xmath7 ( fwhm ) , corresponding to a median circularized effective radius ( @xmath8 ) of 0.67@xmath9kpc , comparable to the typical size of the stellar component measured in compact quiescent galaxies at @xmath10 ( cqgs ) @xmath11kpc .
the median surface sfr density of our smgs is 100@xmath12m@xmath3yr@xmath5kpc@xmath13 , comparable to that seen in local merger - driven ( u)lirgs rather than in extended disk galaxies at low and high redshifts .
the discovery of compact starbursts in @xmath14 smgs strongly supports a massive galaxy formation scenario wherein @xmath156 smgs evolve into the compact stellar components of @xmath16 cqgs .
these cqgs are then thought to evolve into the most massive ellipticals in the local universe , mostly via dry mergers .
our results thus suggest that @xmath14 smgs are the likely progenitors of massive local ellipticals , via cqgs , meaning that we can now trace the evolutionary path of the most massive galaxies over a period encompassing @xmath17% of the age of the universe . .
And you have already written the first three sentences of the full article: the most massive galaxies in the local universe are thought to have evolved to their current state via a series of dry mergers of relatively gas - poor galaxies over the last 10gyr ( e.g. * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
their ancestors the so - called compact quiescent galaxies ( cqgs ) are found at @xmath10 in sensitive , near - infrared ( nir ) imaging surveys ( e.g. * ? ? ? |
7,701 | Suppose that you have an abstract for a scientific paper: in his paper `` on the number of primes less than a given magnitude''@xcite , bernhard riemann introduced a prime counting function @xmath0 which counts the number of primes under @xmath1 .
riemann obtained an analytic expression for @xmath0 by evaluating an inverse laplace transform .
his method involved advanced techniques of analysis .
however , this transform can be evaluated using the residue theorem when an appropriate branch of @xmath2 is defined . in this paper , a method for constructing a holomorphic branch of @xmath2 extending to the left half - plane is described along with it s geometry surrounding the logarithmic branch points . using this information , an integral representation of @xmath0
is formulated in terms of this branch of @xmath3 which is then evaluated .
the results are shown equal to riemann s expression . .
And you have already written the first three sentences of the full article: the focus of this paper is three - fold : 1 . to review an historically significant problem in analytic number theory , 2 . to describe a particular branch of @xmath2 , 3 . using ( 2 ) , solve ( 1 ) in a more elementary way . in 1859 , bernhard riemann published `` on the number of primes less than a given magnitude''@xmath4 , and introduced an analytic continuation of the euler product he called the zeta function : @xmath5 . using @xmath5 , infinite product representations of the @xmath6 and @xmath7 functions and relying on advanced principles of analysis , riemann went on to derive an analytic expression for a function he called @xmath0 equal to the number of prime numbers under @xmath1 .
however , if a branch of @xmath2 is carefully chosen , riemann s expression for @xmath0 can be derived via the residue theorem using simpler techniques of analysis .
this approach is described below . throughout this paper ,.
Please generate the next two sentences of the article | a complex variable is represented as @xmath8 , and the non - trivial zeros of the zeta function with positive imaginary component as @xmath9 ( or just @xmath10 in some cases ) , such that @xmath11 .
the principal branch of the complex logarithm is denoted by log and other branches are given by log . |
7,702 | Suppose that you have an abstract for a scientific paper: the overlap formulation of regulated vectorial and chiral gauge theories is reviewed .
ostensibly new constructions , based on the ginsparg - wilson relation are essentially just overlap with new notation . at present
there exists no satisfactory realization of chiral symmetries outside perturbation theory which is structurally different from the overlap .
# 1#2#3#4#1 * # 2 * , # 3 ( # 4 ) 11.15.ha , 12.38.gc .
And you have already written the first three sentences of the full article: my talk is divided into five parts . in the first part
the relevance of the chiral fermion issue to fundamental particle physics and to numerical qcd will be explained . in the second part
the basic ideas of the overlap construction will be reviewed . in the third part.
Please generate the next two sentences of the article | i shall focus on the algebraic ( as opposed to kinematic ) meaning of the overlap . in the fourth part
i shall discuss in greater detail the overlap dirac operator on the lattice . in the last part |
7,703 | Suppose that you have an abstract for a scientific paper: galaxy structure and morphology is nearly always studied using the light originating from stars , however ideally one is interested in measuring structure using the stellar mass distribution . not only does stellar mass trace out the underlying distribution of matter it also minimises the effects of star formation and dust on the appearance and structure of a galaxy .
we present in this paper a study of the stellar mass distributions and structures of galaxies at @xmath0 as found within the goods fields .
we use pixel by pixel k - corrections to construct stellar mass and mass - to - light ratio maps of 560 galaxies of known morphology at magnitudes @xmath1 .
we measure structural and size parameters using these stellar mass maps , as well as on acs @xmath2 band imaging .
this includes investigating the structural @xmath3gini-@xmath4 parameters and half - light radius ( @xmath5 ) for each galaxy .
we further identify and examine unusual galaxy types with this method , including compact and peculiar ellipticals , and peculiar galaxies in some mode of formation .
we compare structural parameters and half - light radii in the acs @xmath6-band and stellar mass maps , finding no systematic bias introduced by measuring galaxy sizes in @xmath6 .
we furthermore investigate relations between structural parameters in the acs @xmath2 bands and stellar mass maps , and compare our result to previous morphological studies . combinations of various parameters in stellar mass generally reveal clear separations between early and late type morphologies , but can not easily distinguish between star formation and dynamically disturbed systems .
we also show that while ellipticals and early - type spirals have fairly constant cas values at @xmath0 we find a tendency for late - type spiral and peculiar morphological types to have a higher @xmath7 at higher redshift .
we argue that this , and the large fraction of peculiars that appear spiral - like in stellar mass maps , are possible evidence for either an....
And you have already written the first three sentences of the full article: one of the most intriguing questions in modern astronomy is how the universe assembled into the structures we see today .
a major part of this question is understanding how galaxies formed over cosmic time
. a popular and rapidly developing method of tracing the evolution of galaxies is through examining galaxy morphologies and structures over a range of redshifts ( e.g. conselice 2003 ; conselice , rajgor & myers 2008 ; conselice et al ..
Please generate the next two sentences of the article | 2009 ; lotz 2008 ; cassata et al .
2010 ; ricciardelli et al . 2010 ; weinzirl et al . |
7,704 | Suppose that you have an abstract for a scientific paper: it is demonstrated that there is a dynamic isospin breaking effect in the near threshold @xmath0 reaction due to the mass difference of the up and down quarks , which also causes isospin breaking in the @xmath1 system .
the photopion reaction is affected through final state @xmath1 interactions ( formally implemented by unitarity and time reversal invariance ) .
it is also demonstrated that the near threshold @xmath2 reaction is a practical reaction to measure isospin breaking in the @xmath1 system , which was first predicted by weinberg about 20 years ago but has never been experimentally tested . since the discovery of a large mass difference between the up and down quarks ( @xmath3 ) there has been considerable interest in the possibility of observing dynamical isospin breaking in the pion - nucleon system @xcite .
the theoretical consensus is that the magnitude of isospin breaking is not @xmath4 , but instead is @xmath5 @xcite , where @xmath6 0.2 gev . in this paper
it will be shown for the first time that the @xmath7 reaction is an excellent candidate to measure dynamic isospin violations due to the up , down quark mass difference .
weinberg first showed that there is an isospin violating effect in the s wave @xmath1 scattering length @xmath8 due to the up , down quark mass difference @xcite .
this predicted effect , which occurs for @xmath9 scattering or charge exchange but not for @xmath10 scattering , has more recently been calculated by chiral perturbation theory ( chpt ) @xcite .
the predicted magnitude of this effect is the same ( to within a factor of @xmath11 in @xmath12 scattering and charge exchange reactions .
however , since the magnitude of @xmath13 is small , the relative magnitude of the isospin violating term is @xmath14 30 % @xcite .
by contrast , for charge exchange where the isospin conserving amplitude is larger , the relative isospin violation is estimated to be @xmath14 2 to 3 % @xcite . in this paper
the ( dynamic ) isospin breaking effect of the up....
And you have already written the first three sentences of the full article: i would like to thank f.e.low for his collaboration in deriving eq .
many fruitful discussions i would like to thank u.g .
meiner , n.kaiser , b.holstein , and u.b.vankolk . for critical help with the manuscript.
Please generate the next two sentences of the article | i would like to thank m.distler and m.pavan .
s. weinberg , transactions of the n.y . |
7,705 | Suppose that you have an abstract for a scientific paper: the analytic solution for the kinetic description of binary reactions can be seen as the continuum version of a basic discrete iterate mapping .
this fact allows a clear definition of the reaction characteristic time which takes the backward effect into account . .
And you have already written the first three sentences of the full article: in most usual laboratory and/or astrophysical conditions chemical reactions of type @xmath0 are well described by the kinetic approach @xcite . if @xmath1 , @xmath2 are the concentrations of species @xmath3 and @xmath4 , and @xmath5 , the problem is fixed by the relative concentrations @xmath6 suppose some method is given for picking particles of types @xmath3 and @xmath4 while sampling the system . concentrations @xmath7 and @xmath8 are then the relative probabilities of getting particles of the corresponding species at time @xmath9 .
the reaction rates are typically given by the inverse times of free - flight , or velocity/(mean free path ) ratios : if @xmath10 is the average velocity of type-@xmath11 particles , @xmath12 where @xmath13 and @xmath14 are the corresponding reaction cross - sections .
the kinetic picture underlying such definitions is well known @xcite : in eq.([reactionrate11 ] ) , for example , @xmath15 is the effective cylindric volume presented by particle @xmath16 to particle @xmath3 per second ..
Please generate the next two sentences of the article | particle @xmath16 will consequently meet @xmath17 particles @xmath3 per second .
the relative concentrations as functions of time are then described by the master ( or gain / loss ) equations @xmath18 variation in the abundance of species @xmath3 is the abundance of species @xmath4 times the rate of @xmath4-to-@xmath3 transformation ( which represents the gain ) minus the @xmath3 abundance times the rate of its disappearance ( the loss ) . |
7,706 | Suppose that you have an abstract for a scientific paper: toric ( or sparse ) elimination theory is a framework developped during the last decades to exploit monomial structures in systems of laurent polynomials . roughly speaking
, this amounts to computing in a _ semigroup algebra _ , _
i.e. _ an algebra generated by a subset of laurent monomials .
in order to solve symbolically sparse systems , we introduce _ sparse grbner bases _ , an analog of classical grbner bases for semigroup algebras , and we propose sparse variants of the @xmath0 and fglm algorithms to compute them .
our prototype `` proof - of - concept '' implementation shows large speed - ups ( more than 100 for some examples ) compared to optimized ( classical ) grbner bases software .
moreover , in the case where the generating subset of monomials corresponds to the points with integer coordinates in a normal lattice polytope @xmath1 and under regularity assumptions , we prove complexity bounds which depend on the combinatorial properties of @xmath2 .
these bounds yield new estimates on the complexity of solving @xmath3-dim systems where all polynomials share the same newton polytope ( _ unmixed case _ ) .
for instance , we generalize the bound @xmath4 on the maximal degree in a grbner basis of a @xmath3-dim .
bilinear system with blocks of variables of sizes @xmath5 to the multilinear case : @xmath6 .
we also propose a variant of frberg s conjecture which allows us to estimate the complexity of solving overdetermined sparse systems . .
And you have already written the first three sentences of the full article: * context and problem statement . * many polynomial systems or systems of laurent polynomials arising in applications do not have a dense monomial structure ( _ e.g _ multi - homogeneous systems , fewnomials , systems invariant under the action of a linear group , ) .
the development of toric geometry during the 70s/80s has led to toric ( or sparse ) elimination theory @xcite , a framework designed to study and exploit algorithmically these monomial structures .
central objects in toric geometry are _ semigroup algebras _ ( also called toric rings ) . if @xmath7 is an affine semigroup ( see def ..
Please generate the next two sentences of the article | [ def : affinesgp ] ) , then the semigroup algebra @xmath8 $ ] is the set of finite sums @xmath9 , where @xmath10 is a formal symbol , @xmath11 is a field , @xmath12 and @xmath13 .
semigroup algebras are isomorphic to subalgebras of @xmath14 $ ] generated by a finite subset of monomials . |
7,707 | Suppose that you have an abstract for a scientific paper: we look for topological bps solutions of an abelian - maxwell - higgs theory endowed by non - standard kinetic terms to both gauge and scalar fields . here , the non - usual dynamics are controlled by two positive functions , @xmath0 and @xmath1 , which are related to the self - dual scalar potential @xmath2 of the model by a fundamental constraint .
the numerical results we found present interesting new features , and contribute to the development of the recent issue concerning the study of generalized models and their applications . .
And you have already written the first three sentences of the full article: in the context of classical field theories , topological structures , such as kinks @xcite , vortices @xcite and magnetic monopoles @xcite , are described as static solutions to some nonlinear models . in particular
, such models must allow for the spontaneous symmetry breaking mechanism , since topological solutions are formed during a symmetry breaking phase transition . in this sense , topologically non - trivial configurations are of great interesting to physics @xcite , mainly concerning the cosmological consequences they may engender , since such configurations can appear in a rather natural way , during phase transitions in the early universe . in particular
, vortices are described as rotationally symmetric solutions of a planar abelian - maxwell - higgs model endowed by a fourth - order scalar potential for the matter self - interaction , which also introduces symmetry breaking and nonlinearity . in the usual case.
Please generate the next two sentences of the article | , the maxwell term controls the dynamics of the gauge field , and the covariant derivative squared term controls the dynamics of the scalar field . in such context , vortices are finite - energy solutions of a set of two coupled first - order differential equations , named bogomolnyi - prasad - sommerfield ( bps ) equations @xcite . in this case , the bps vortices are the minimal - energy solutions of the model , and they have interesting applications , mainly concerning the superconductivity phenomena @xcite and the superfluid he@xmath3 . during the last years , beyond the standard configurations
previously cited , modified ones , also named _ |
7,708 | Suppose that you have an abstract for a scientific paper: we prove the following estimate for the spectrum of the normalized laplace operator @xmath0 on a finite graph @xmath1 , @xmath2)^{\frac{1}{t}}\leq \lambda_1 \leq \cdots \leq \lambda_{n-1}\leq 1 + ( 1- k[t])^{\frac{1}{t } } , \,\forall \,\,\text{integers}\,\ , t\geq 1.\ ] ] here @xmath3 $ ] is a lower bound for the ollivier - ricci curvature on the neighborhood graph @xmath4 $ ] ( here we use the convention @xmath5=g$ ] ) , which was introduced by bauer - jost . in particular , when @xmath6 this is ollivier s estimate @xmath7 and a new sharp upper bound @xmath8 for the largest eigenvalue .
furthermore , we prove that for any @xmath1 when @xmath9 is sufficiently large , @xmath10)^{\frac{1}{t}}$ ] which shows that our estimates for @xmath11 and @xmath12 are always nontrivial and the lower estimate for @xmath11 improves ollivier s estimate @xmath7 for all graphs with @xmath13 . by definition neighborhood graphs possess many loops .
to understand the ollivier - ricci curvature on neighborhood graphs , we generalize a sharp estimate of the curvature given by jost - liu to graphs which may have loops and relate it to the relative local frequency of triangles and loops . .
And you have already written the first three sentences of the full article: in this paper , we utilize techniques inspired by riemannian geometry and the theory of stochastic processes in order to control eigenvalues of graphs . in particular , we shall quantify the deviation of a ( connected , undirected , weighted , finite ) graph @xmath1 from being bipartite ( a bipartite graph is one without cycles of odd lengths ; equivalently , its vertex set can be split into two classes such that edges can be present only between vertices from different classes ) in terms of a spectral gap .
the operator whose spectrum we shall consider here is the normalized graph laplacian @xmath0 ( it is unitarily equivalent to the one studied in chung @xcite ) .
this is the operator underlying random walks on graphs , and so , this leads to a natural connection with the theory of stochastic processes ..
Please generate the next two sentences of the article | we observe that on a bipartite graph , a random walker , starting at a vertex @xmath14 at time 0 and at each step hopping to one of the neighbors of the vertex where it currently sits , can revisit @xmath14 only at even times .
this connection then will be explored via the eigenvalues of @xmath0 . |
7,709 | Suppose that you have an abstract for a scientific paper: we report the discovery and the analysis of the planetary microlensing event , ogle-2013-blg-1761 .
there are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled .
but the detailed light curve analysis ruled out all stellar binary models and shows that the lens to be a planetary system .
there is the so - called close / wide degeneracy in the solutions with the planet / host mass ratio of @xmath0 and @xmath1 with the projected separation in einstein radius units of @xmath2 ( close ) and @xmath3 ( wide ) , respectively .
the microlens parallax effect is not detected but the finite source effect is detected .
our bayesian analysis indicates that the lens system is located at @xmath4 away from us and the host star is an m / k - dwarf with the mass of @xmath5 orbited by a super - jupiter mass planet with the mass of @xmath6 at the projected separation of @xmath7 .
the preference of the large lens distance in the bayesian analysis is due to the relatively large observed source star radius
. the distance and other physical parameters can be constrained by the future high resolution imaging by ground large telescopes or _
hst_. if the estimated lens distance is correct , this planet provides another sample for testing the claimed deficit of planets in the galactic bulge . .
And you have already written the first three sentences of the full article: gravitational microlensing is a unique technique to find exoplanets down to low masses @xcite just beyond the snow line @xcite which plays an important role in the core accretion theory of planet formation @xcite .
microlensing is presently the only technique able to find planets down to an earth size mass at these orbital radii .
microlensing is also sensitive to planets orbiting around faint stars like m - dwarfs and brown dwarfs , and can even detect free - floating planets @xcite because it does not rely on the host s light ..
Please generate the next two sentences of the article | this is complimentary to the other methods like the radial velocity @xcite and the transit @xcite methods which are sensitive to planets close to their host stars .
several survey groups are conducting high cadence survey observations for microlensing events towards the galactic bulge . to date , about 50 exoplanets have been found by microlensing thanks to their continuous effort . |
7,710 | Suppose that you have an abstract for a scientific paper: in this paper we test the results of a recent analytical study by lazarian and pogosyan , on the statistics of emissivity in velocity channel maps , in the case of realistic density and velocity fields obtained from numerical simulations of mhd turbulence in the interstellar medium ( ism ) . to compensate for the lack of well - developed inertial ranges in the simulations due to the limited resolution
, we apply a procedure for modifying the spectral slopes of the fields while preserving the spatial structures .
we find that the density and velocity are moderately correlated in space and prove that the analytical results by lazarian and pogosyan hold in the case when these fields obey the fluid conservation equations .
our results imply that the spectra of velocity and density can be safely recovered from the position - position - velocity ( ppv ) data cubes available through observations , and confirm that the relative contributions of the velocity and density fluctuations to those of the emissivity depend on the velocity resolution used and on the steepness of the density spectral index .
furthermore , this paper supports previous reports that an interpretation of the features in the ppv data cubes as simple density enhancements ( i.e. , `` clouds '' ) can be often erroneous , as we observe that changes in the velocity statistics substantially modify the statistics of emissivity within the velocity data cubes .
* u * .
And you have already written the first three sentences of the full article: it is generally accepted that interstellar turbulence plays a crucial role in many astrophysical processes , including molecular cloud and star formation , mass and energy transfer in accretion disks , acceleration of cosmic rays , etc . at present
we are still groping for the basic facts related to this complex phenomenon and one of the reasons for such an unsatisfactory state of affairs is that the interstellar turbulence statistics are not directly available .
for instance , in studies of the neutral medium , indirect measures , such as spectral line widths and centroids of velocity , are employed ( e.g. miesch & bally 1994 ; see also the review by scalo 1987 ) , while potentially more valuable sources of information available in velocity - channel maps remain mostly untapped ( although see heyer & schloerb 1997 ; rosolowsky et al ..
Please generate the next two sentences of the article | 1999 ; brunt & heyer 2000 ) because of the difficulty of relating the two - dimensional ( 2d ) statistics available through observations to the underlying three - dimensional ( 3d ) statistics .
a discussion of various approaches to the problem of turbulence study using spectral line data can be found in a recent review by lazarian ( 1999 ) . |
7,711 | Suppose that you have an abstract for a scientific paper: cartan matrices are of fundamental importance in representation theory . for algebras defined by quivers with monomial relations the computation of the entries of the cartan
matrix amounts to counting nonzero paths in the quivers , leading naturally to a combinatorial setting .
our main motivation are derived module categories and their invariants : the invariant factors , and hence the determinant , of the cartan matrix are preserved by derived equivalences .
the paper deals with the class of ( skewed- ) gentle algebras which occur naturally in representation theory , especially in the context of derived categories .
we study @xmath0-cartan matrices , where each nonzero path is weighted by a power of an indeterminate @xmath0 according to its length . specializing @xmath1
gives the classical cartan matrix .
we determine normal forms for the @xmath0-cartan matrices of skewed - gentle algebras .
in particular , we give explicit combinatorial formulae for the invariant factors and thus also for the determinant . as an application of our main results
we show how to use our formulae for the difficult problem of distinguishing derived equivalence classes .
msc - classification : 16g10 , 18e30 , 05e99 , 05c38 , 05c50 * @xmath0-cartan matrices and combinatorial invariants of derived categories for skewed - gentle algebras * * christine bessenrodt * fakultt fr mathematik und physik , universitt hannover , + welfengarten 1 , d-30167 hannover , germany * thorsten holm * department of pure mathematics , university of leeds , + leeds ls2 9jt , england .
And you have already written the first three sentences of the full article: this paper deals with combinatorial aspects in the representation theory of algebras .
more precisely , for certain classes of algebras which are defined purely combinatorially by directed graphs and homogeneous relations we will characterize important representation - theoretic invariants in a combinatorial way .
in particular , this leads to new explicit invariants for the derived module categories of the algebras involved . the starting point for this article.
Please generate the next two sentences of the article | is that the unimodular equivalence class of the cartan matrix of a finite dimensional algebra is invariant under derived equivalence .
hence , being able to determine normal forms of cartan matrices yields invariants of the derived category . |
7,712 | Suppose that you have an abstract for a scientific paper: standing waves near the zigzag and armchair edges , and their berry s phases are investigated .
it is suggested that the berry s phase for the standing wave near the zigzag edge is trivial , while that near the armchair edge is non - trivial .
a non - trivial berry s phase implies the presence of a singularity in parameter space .
we have confirmed that the dirac singularity is absent ( present ) in the parameter space for the standing wave near the zigzag ( armchair ) edge .
the absence of the dirac singularity has a direct consequence in the local density of states near the zigzag edge .
the transport properties of graphene nanoribbons observed by recent numerical simulations and experiments are discussed from the point of view of the berry s phases for the standing waves .
the electronic property of a graphene nanoribbon differs greatly from that of a carbon nanotube .
a metallic carbon nanotube exhibits a high mobility , while a graphene nanoribbon shows a transport gap .
@xcite the high mobility observed in metallic carbon nanotubes indicates that the scatterers are not effective in producing backward scattering .
there should be a mechanism which suppresses the backward scattering in metallic carbon nanotubes .
suppose that an electron with momentum @xmath0 is coming into the impurities which are represented by the circles in fig .
[ fig : abs](a ) .
the electron is scattered by the impurities and changes its momentum direction .
let us consider the probability amplitude that the electron is scattered in the backward direction , as shown in fig .
[ fig : abs](a ) . in this case , the final wave function , @xmath1 , is given by rotating the wave vector of the initial state , @xmath2 , by @xmath3 , so that we have the relationship between the initial state and final state as @xmath4 where @xmath5 is a rotational operator with angle @xmath6 .
note that this particular path shown in fig .
[ fig : abs](a ) is not the unique path that an electron can follow .
there....
And you have already written the first three sentences of the full article: this work is financially supported by a grant - in - aid for specially promoted research ( no .
20001006 ) from the ministry of education , culture , sports , science and technology ..
Please generate the next two sentences of the article | |
7,713 | Suppose that you have an abstract for a scientific paper: we calculate the nuclear matrix elements ( nmes ) for neutrinoless double - beta decays ( @xmath0 ) of @xmath1-shell nuclei using the shell model ( sm ) and energy density functional ( edf ) methods .
the systematic study of non - physical decays ( except for @xmath2ca ) of ca@xmath3ti , ti@xmath3cr and cr@xmath3fe allows for a detailed comparison between the two nuclear structure approaches .
we observe that while the dominant gamow - teller part of the nme differs roughly by a factor of two between sm and edf , when we restrict the calculations to spherical edf states and seniority - zero sm configurations , the nmes obtained by both methods are strikingly similar .
this points out to the important role of nuclear structure correlations for @xmath0 decay nmes .
we identify correlations associated with high - seniority components in the initial and final states of the decay as one of the reasons for the discrepancies between sm and edf results .
we also explore exact projection to good isospin , and conclude that it has only a moderate effect in the gamow - teller part of the nmes but strongly affects the fermi contribution .
this work opens up the door for nme benchmarks between different theoretical approaches , and constitutes a step forward towards more reliable estimations of the nmes . .
And you have already written the first three sentences of the full article: [ intro ] experimental searches for the lepton - number violating weak process neutrinoless double beta decay ( @xmath0 decay ) are the most promising approach to determine some of the fundamental properties of neutrinos .
the detection of @xmath0 decay would establish the majorana character of neutrinos and provide information about their absolute mass and hierarchy @xcite .
ongoing experiments exo @xcite , kamland - zen @xcite and gerda @xcite have recently set impressive lower - limits , well over @xmath4 years , on the half - lives of @xmath5xe and @xmath6ge , and the dozen most favorable nuclei are being explored worldwide @xcite ..
Please generate the next two sentences of the article | however , an eventual @xmath0 decay detection does not guarantee the precise determination of absolute neutrino masses , because the half - life depends on the transition nuclear matrix elements ( nme ) , @xmath7 @xcite : @xmath8^{-1}=g_{0\nu}|m^{0\nu}|^{2}\left(\frac{\langle m_{\beta\beta}\rangle}{m_{e}}\right)^{2 } , \label{half_life}\ ] ] with @xmath9 the electron mass and @xmath10 a well - known phase - space factor @xcite .
the combination of neutrino masses that appears in @xmath0 decay is @xmath11 , with @xmath12 the neutrino mixing matrix . |
7,714 | Suppose that you have an abstract for a scientific paper: we study a recurrence defined on a three dimensional lattice and prove that its values are laurent polynomials in the initial conditions with all coefficients equal to one .
this recurrence was studied by propp and by fomin and zelivinsky .
fomin and zelivinsky were able to prove laurentness and conjectured that the coefficients were 1 .
our proof establishes a bijection between the terms of the laurent polynomial and the perfect matchings of certain graphs , generalizing the theory of aztec diamonds . in particular
, this shows that the coefficients of this polynomial , and polynomials obtained by specializing its variables , are positive , a conjecture of fomin and zelevinsky . .
And you have already written the first three sentences of the full article: the octahedron recurrence is the product of three chains of research seeking a common generalization .
the first is the study of the algebraic relations between the connected minors of a matrix , and particularly of a recurrence relating them known and dodgson condensation . attempting to understand the combinatorics of dodgson condensation lead to the discovery of alternating sign matrices and aztec diamonds .
aztec diamonds are graphs whose perfect matchings have extremely structured combinatorics and soon formed their own , second line of research as other graphs were discovered with the similar regularities . the third is the study of somos - sequences and the laurent phenomenon , which began with an attempt to understand theta functions from a combinatorial perspective . in this section.
Please generate the next two sentences of the article | we will sketch both lines of research . in the following section
, we will begin to describe the vocabulary and main results of this paper . |
7,715 | Suppose that you have an abstract for a scientific paper: using the extension of the standard hawking - hartle prescription for defining a wave function for the universe , we show that it is possible , given a suitable form for the scalar field potential , to have the universe begin at its largest size and thereafter contract , with the growth of perturbations proceeding from small , at the largest size , to largest when the universe is small .
this solution would dominate the wave function by an exponentially large amount if one chooses the hartle hawking prescription for the wave - function , but is exponentially sub - dominant for the linde - vilenkin prescription . #
1#2 figure # 1 _ # 2 _ epsf .
And you have already written the first three sentences of the full article: in a surprising result , hartle and hawking twenty years ago showed @xcite how , at least in the semi - classical theory of quantum gravity , one could give an intuitively appealing definition for a preferred wave function for the universe .
if one believes that nature selects this definition , then they argued that this wave function explains various features which we observe the universe to have .
one of these features is that the universe is simple when it is small @xcite and becomes more and more complex as it grows in size ..
Please generate the next two sentences of the article | while hawking originally believed that the universe must always be simple when small @xcite , page and laflamme @xcite pointed out that this wave - function would be expected to also contain probablilities for the universe to be complex when small .
this was interpreted as indicating a classical history of the universe which began simple when small , expanded , with the gravitational instability causing growth in the quantum fluctuations present when small . |
7,716 | Suppose that you have an abstract for a scientific paper: we explore the quantified morphology of atomic hydrogen ( ) disks in the virgo cluster .
these galaxies display a wealth of phenomena in their morphology , e.g. , tails , truncation and warps .
these morphological disturbances are related to the ram - pressure stripping and tidal interaction that galaxies undergo in this dense cluster environment . to quantify the morphological transformation of the disks ,
we compute the morphological parameters of concentration - asymmetry - smoothness , gini and 20 and our own for 51 galaxies in 48 column density maps from the vla imaging of virgo spirals in atomic gas ( viva ) project .
some morphological phenomena can be identified in this space of relatively low resolution data .
truncation of the disk can be cleanly identified via the concentration parameter ( c@xmath01 ) and concentration can also be used to identify deficient disks ( 1@xmath0c@xmath05 ) .
tidal interaction is typically identified using combinations of these morphological parameters , applied to ( optical ) images of galaxies .
we find that some selection criteria ( gini-@xmath1 , asymmetry , and a modified concentration-@xmath1 ) are still applicable for the coarse ( @xmath215@xmath3 fwhm ) viva data .
we note that asymmetry is strongly affected by the choice for the center of these galaxies .
the phenomena of tidal tails can be reasonably well identified using the gini-20 criterion ( 60 % of galaxies with tails identified but with as many contaminants ) .
ram - pressure does move disks into and out of most of our interaction criteria : the ram - pressure sequence identified by vollmer et al .
( 2009 ) tracks into and out of some of these criteria ( asymmetry based and the gini-@xmath1 selections , but not the concentration-20 or the based ones ) .
therefore , future searches for interaction using morphologies should take ram - pressure into account as a mechanism to disturb disks enough to make them appear as gravitationally interacting .
one mechanism....
And you have already written the first three sentences of the full article: the virgo cluster represents an ideal laboratory for the study of galaxy evolution in a cluster environment .
it is one of the nearest galaxy clusters ( d@xmath217 mpc ) , a relatively populous system ( abell richness class i ) , consisting of some two thousand catalogued members in the virgo cluster catalogue ( vcc , * ? ? ?
the virgo cluster is spiral - rich and dynamically young , i.e. , made of galaxy subgroups which are falling into the main cluster ..
Please generate the next two sentences of the article | the most prominent groups are those associated with m86 to the west and m49 to the south .
a particularity of the virgo cluster is that the distribution of its hot intracluster medium is strongly peaked on the central cd galaxy m87 @xcite , and overall highly sub - structured . |
7,717 | Suppose that you have an abstract for a scientific paper: we study the physics of electron acceleration at collisionless shocks that move through a plasma containing large - scale magnetic fluctuations .
we numerically integrate the trajectories of a large number of electrons , which are treated as test particles moving in the time dependent electric and magnetic fields determined from 2-d hybrid simulations ( kinetic ions , fluid electron ) . the large - scale magnetic fluctuations effect the electrons in a number of ways and lead to efficient and rapid energization at the shock front .
since the electrons mainly follow along magnetic lines of force , the large - scale braiding of field lines in space allows the fast - moving electrons to cross the shock front several times , leading to efficient acceleration .
ripples in the shock front occuring at various scales will also contribute to the acceleration by mirroring the electrons .
our calculation shows that this process favors electron acceleration at perpendicular shocks .
the current study is also helpful in understanding the injection problem for electron acceleration by collisionless shocks .
it is also shown that the spatial distribution of energetic electrons is similar to in - situ observations ( e.g. , * ? ? ?
* ; * ? ? ?
* ) .
the process may be important to our understanding of energetic electrons in planetary bow shocks and interplanetary shocks , and explaining herringbone structures seen in some type ii solar radio bursts . .
And you have already written the first three sentences of the full article: collisionless shocks are widely believed to be the primary acceleration mechanism giving rise to the ubiquitous existence of energetic particles in space .
the theory of diffusive shock acceleration ( dsa ) was proposed some @xmath0 years ago @xcite and is currently believed to be the most important mechanism for a variety of astrophysical environments , for example , interplanetary shocks , the heliospheric termination shock , and shocks associated with supernova remnants .
the theory predicts a universal power - law energy flux spectrum @xmath1 for strong shocks with a density compression ratio of 4 ..
Please generate the next two sentences of the article | the physical mechanism by which particles are accelerated from thermal energies to much higher energies where dsa is presumed to be applicable ( the injection problem ) has received some recent attentions but has not reached a common consensus explanation .
many acceleration theories , for example , shock drift acceleration ( sda ) ( see reviews , * ? ? ? * ; * ? ? ? |
7,718 | Suppose that you have an abstract for a scientific paper: we present a new parallel algorithm for the exact diagonalization of the @xmath0-hubbard model with the lanczos - method . by invoking a new scheme of labeling the states we were able to obtain a speedup of up to four on 16 nodes of an ibm sp2 for the calculation of the ground state energy and an almost linear speedup for the calculation of the correlation functions . using this algorithm we performed an extensive study of the influence of the next - nearest hopping parameter @xmath1 in the @xmath0-hubbard model on ground state energy and the superconducting correlation functions for both attractive and repulsive interaction . .
And you have already written the first three sentences of the full article: the hubbard model @xcite is one of the generic models in many particle physics . due to difficulties with the analytic solution of the hubbard model in two dimensions ,
this model is intensively studied with various numerical algorithms , e.g. exact diagonalization @xcite , @xcite , @xcite @xcite , stochastic diagonalization @xcite , @xcite and quantum monte carlo algorithms @xcite , @xcite , @xcite , @xcite . the single band hubbard model with additional
next nearest neighbor hopping is given in real the space by : @xmath2 the sum @xmath3 is over the nearest neighbors and @xmath4 is the sum over the next nearest neighbors ..
Please generate the next two sentences of the article | @xmath5 is the creation operator for an electron with spin @xmath6 on site @xmath7 and @xmath8 is the corresponding number operator . throughout this article
we take @xmath9 as energy unit . in the momentum space |
7,719 | Suppose that you have an abstract for a scientific paper: we propose a _ distribution - free _ approach to the study of random geometric graphs .
the distribution of vertices follows a poisson point process with intensity function @xmath0 , where @xmath1 , and @xmath2 is a probability density function on @xmath3 .
a vertex located at @xmath4 connects via directed edges to other vertices that are within a _ cut - off _
distance @xmath5 .
we prove strong law results for ( i ) the critical cut - off function so that almost surely , the graph does not contain any node with out - degree zero for sufficiently large @xmath6 and ( ii ) the maximum and minimum vertex degrees .
we also provide a characterization of the cut - off function for which the number of nodes with out - degree zero converges in distribution to a poisson random variable .
we illustrate this result for a class of densities with compact support that have at most polynomial rates of decay to zero .
finally , we state a sufficient condition for an enhanced version of the above graph to be almost surely connected eventually . . .
And you have already written the first three sentences of the full article: in this paper we study the asymptotic properties related to connectivity of random geometric graphs where the underlying distribution of the vertices may not be uniform . a random geometric graph ( rgg ) consists of a set of vertices that are distributed in space independently , according to some common probability density function .
the edge set of the graph consists of the set of all pairs of points that are within a specified cut - off distance .
our point of departure from usual random geometric graphs is the specification of a cut - off function @xmath7 that determines the edge set ..
Please generate the next two sentences of the article | a directed edge exists , from a vertex located at @xmath4 to another vertex located at @xmath8 , provided the distance between @xmath4 and @xmath8 is less than @xmath9 .
our motivation for the study of such graphs comes from applications in wireless networks . in models of wireless networks as rggs |
7,720 | Suppose that you have an abstract for a scientific paper: we consider the dynamics of a cosmological substratum of pressureless matter and holographic dark energy with a cutoff length proportional to the ricci scale .
stability requirements for the matter perturbations are shown to single out a model with a fixed relation between the present matter fraction @xmath0 and the present value @xmath1 of the equation - of - state parameter of the dark energy .
this model has the same number of free parameters as the @xmath2cdm model but it has no @xmath2cdm limit .
we discuss the consistency between background observations and the mentioned stability - guaranteeing parameter combination . .
And you have already written the first three sentences of the full article: among the alternative approaches to describe the dark cosmological sector , consisting of dark matter ( dm ) and dark energy ( de ) , so called holographic de models have received considerable attention @xcite . the underlying holographic principle states that the number of degrees of freedom in a bounded system should be finite and related to the area of its boundary @xcite . on this basis ,
a field theoretical relation between a short distance ( ultraviolet ) cutoff and a long distance ( infrared ) cutoff was established @xcite .
such relation ensures that the energy in a box of size @xmath3 does not exceed the energy of a black hole of the same size ..
Please generate the next two sentences of the article | if applied to the dynamics of the universe , @xmath3 has to be a cosmological length scale .
different choices of this cutoff scale result in different de models . for the most obvious choice , the hubble scale , only models in which dm and de are interacting with each other also nongravitationally , give rise to a suitable dynamics @xcite . |
7,721 | Suppose that you have an abstract for a scientific paper: we analyze properties of local polyakov loops using quenched as well as dynamical su(3 ) gauge configurations for a wide range of temperatures . it is demonstrated that for both , the confined and the deconfined regime , the local polyakov loop prefers phase values near the center elements @xmath0 .
we divide the lattice sites into three sectors according to these phases and show that the sectors give rise to the formation of clusters . for a suitable definition of these clusters we find that in the quenched case deconfinement manifests itself as the onset of percolation of the clusters . a possible continuum limit of the center clusters is discussed . .
And you have already written the first three sentences of the full article: with the running and upcoming experiments at lhc , rhic and gsi the analysis of the qcd phase diagram has become an important focus of research .
not only the transition curves which separate different phases are of interest , but one would also like to understand from first principles the physical mechanisms that drive the various transitions .
in this project we probe the finite temperature transition of qcd using static quark sources . in the framework of lattice qcd.
Please generate the next two sentences of the article | these can be implemented using local polyakov loops .
the local polyakov loop @xmath1 is given by the trace of the product of temporal gauge links @xmath2 at a fixed spatial position @xmath3 ( @xmath4 is the number of lattice points in time direction ) : @xmath5 i.e. , the polyakov loop is a gauge transporter that propagates a static quark at position @xmath3 forward in time . for later use |
7,722 | Suppose that you have an abstract for a scientific paper: we present co(1 - 0 ) and co(2 - 1 ) maps of the seyfert galaxy ngc 5728 .
although a stellar nuclear bar structure is clearly identified in the near - infrared images in the central 10 `` , inside the ring identified as the ilr of the primary bar , there is no nuclear bar structure in the molecular gas .
instead , the co emission reveals an elongated structure , 15 '' in length , beginning at the nucleus ( defined by the radio center ) aligned with the jet / ionisation cone , at a pa of 127 degrees .
this morphology , not frequently observed in seyfert galaxies , may be interpreted in terms of enhanced co excitation along the walls of the cone .
kinematical perturbations along the cone support this scenario . at larger - scale
, co emission is tracing the primary bar , and outer ring structure .
the total molecular mass , estimated from the co emission , is m(h@xmath0 ) = 3.1 10@xmath1 m@xmath2 . .
And you have already written the first three sentences of the full article: ngc 5728 is a well known prototype of embedded bars .
it is classified as ( r1)sab(r)a , and a seyfert 2 ( distance 33 mpc
1=180 pc ) ..
Please generate the next two sentences of the article | its nuclear bar is oriented at 45 degrees of the main bar ( shaw et al 1993 ) , and could rotate faster . petitpas & wilson ( 2002 ) have obtained a co map of ngc 5728 with the ovro interferometer .
they found a total co mass of 3.1 10@xmath3 m@xmath2 . |
7,723 | Suppose that you have an abstract for a scientific paper: we compute the four - loop qcd corrections to the massless quark - anti - quark - photon form factor @xmath0 in the large-@xmath1 limit . from the pole part
we extract analytic expressions for the corresponding cusp and collinear anomalous dimensions .
pacs numbers : 11.15.bt , 12.38.bx , 12.38.cy .
And you have already written the first three sentences of the full article: perturbation theory is a powerful tool to obtain reliable predictions for physical observables within the standard model of particle physics or its extensions . due to the high precision of experimental results , e.g. , at the cern large hadron collider ( lhc ) or at the @xmath2 factories , it is on the one hand mandatory to advance the development of tools , which can be used for higher order calculations . on the other hand
it is necessary to improve the understanding of the perturbative structure of quantum field theories .
form factors are ideal objects to obtain deeper insight into the latter . especially in the context of qcd.
Please generate the next two sentences of the article | they are indispensable tools to investigate the infrared structure of scattering amplitudes to high orders in perturbation theory . moreover , from the pole part it is possible to extract universal process - independent quantities @xcite like the cusp anomalous dimension which can be extracted from the @xmath3 pole of the form factor .
the finite parts of the form factors serve as building blocks for a variety of physical processes . |
7,724 | Suppose that you have an abstract for a scientific paper: the status of the solar axion search with the cern axion solar telescope ( cast ) will be discussed .
results from the first part of cast phase ii where the magnet bores were filled with @xmath0 gas at variable pressure in order to scan @xmath1 up to 0.4 ev will be presented . from the absence of excess x - rays
when the magnet was pointing to the sun , we set a typical upper limit on the axion - photon coupling of @xmath210@xmath3gev@xmath4 at 95% cl for @xmath1@xmath5 ev , the exact result depending on the pressure setting .
our search for axions with masses up to about 1.2 ev using @xmath6 as a buffer gas is , since last year , in progress in the second part of cast phase ii .
expectations for sensibilities will be given .
near future perspectives as well as more long term options for a new helioscope experiment will be evoked . .
And you have already written the first three sentences of the full article: the cast ( cern axion solar telescope ) experiment is using a decommissioned lhc dipole magnet to convert solar axions into detectable x - ray photons .
axions are light pseudoscalar particles that arise in the context of the peccei - quinn@xcite solution to the strong cp problem and can be dark matter candidates@xcite .
stars could produce axions via the primakoff conversion of the plasma photons ..
Please generate the next two sentences of the article | the cast experiment is pointing at our closest star , the sun , aiming to detect solar axions .
the detection principle is based on the coupling of an incoming axion to a virtual photon provided by the transverse field of an intense dipole magnet , being transformed into a real , detectable photon that carries the energy and the momentum of the original axion . |
7,725 | Suppose that you have an abstract for a scientific paper: we show that all generalized pollicott - ruelle resonant states of a topologically transitiv @xmath0 anosov flow with an arbitrary @xmath0 potential , have full support . .
And you have already written the first three sentences of the full article: let @xmath1 be a smooth , compact riemannian manifold without boundary .
let @xmath2 be a smooth anosov vector field and let us denote by @xmath3 the flow on @xmath4 generated by @xmath5 and let @xmath6 be a smooth potential function .
then we can define the following differential operator @xmath7 it is a well established approach to study the dynamical properties of anosov flows by the discrete spectrum of the operator @xmath8 , the so called pollicott - ruelle resonances ..
Please generate the next two sentences of the article | the fact that for volume preserving flows and real valued potentials , the operator @xmath8 is an unbounded , essentially self adjoint operator on @xmath9 might suggest , that @xmath8 has good spectral properties on @xmath9 . however , due to the lack of ellipticity @xmath8 has mainly continuous spectrum which carries little information on the dynamics of the flow .
a very important progress was thus to construct banach spaces @xcite or hilbert spaces @xcite for anosov flows in which the operator @xmath8 has discrete spectrum in a sufficiently large region ( see also @xcite for analogous results for anosov diffeomorphism ) . |
7,726 | Suppose that you have an abstract for a scientific paper: we study the model - independent traversable wormholes from cosmological reconstruction based on gaussian processes ( gp ) . using a combination of union 2.1 sne ia data , the latest observational hubble parameter data and recent planck s shift parameter
, we find that our gp method can give a tighter constraint on the normalized comoving distance , its derivatives and the dark energy equation of state than the previous work @xcite .
subsequently , two specific traversable wormhole solutions are obtained , i.e. , the cases of a constant redshift function and a linear shape function .
we find that , with decreasing cosmic acceleration , the traversal velocity @xmath0 of the former case increases and the amounts of exotic matter @xmath1 of the latter case decreases . .
And you have already written the first three sentences of the full article: modern cosmology has already entered a precise , data - driven era . in 1998 ,
the elegant discovery that the universe is undergoing the phase of accelerated expansion @xcite , has motivated a great deal of studies concentrated on how best to parameterize the dark energy and measure its properties .
an accompanying task comes naturally into being , i.e. , explore the corresponding behaviors at astrophysical scales when investigating the expansion history of the universe for different cosmological theories at cosmological scales ..
Please generate the next two sentences of the article | recently , because of the discovery of the accelerating universe , theorists have gradually paid more and more attention to the exotic spacetime configurations , especially , the renewed field wormholes . to be more concrete , in both cases ( accelerating universe and wormholes ) the null energy condition ( nec ) is violated and consequently all of other energy conditions .
thus , an appealing overlap between two seemingly separated subjects occurs . |
7,727 | Suppose that you have an abstract for a scientific paper: we created 4 _ p - si _ models and 4 _ p - si : h _ models all with 50% porosity .
the models contain 32 , 108 , 256 and 500 silicon atoms with a pore parallel to one of the simulational cell axes and a regular cross - section .
we obtained the densities of states of our models by means of ab initio computational methods .
we wrote a code to simulate the emission spectra of our structures considering particular excitations an decay conditions . after comparing the simulated spectra with the experimental results ,
we observe that the position of the maximum of the emission spectra might be related with the size of the silicon backbone for the _ p - si _ models as the quantum confinement models say and with the hydrogen concentration for the _ p - si : h _ structures .
we conclude that the quantum confinement model can be used to explain the emission of the _ p - si _ structures but , in the case of the _ p - si : h _ models it is necessary to consider others theories . .
And you have already written the first three sentences of the full article: since the discovery of the _ p - si _ photoluminiscence ( pl ) at room temperature realized by l.t .
canham in 1990 @xcite , a lot of studies have been carried out to understand the origin of this property .
the possibility that _ p - si _ could be applied to photonic and optoelectronic devices , motivated the study of the dependency of its pl to the temperature , chemical attack variables and molecules on its surface . despite the big amount of scientific reports about the _.
Please generate the next two sentences of the article | p - si _ pl , until now , we have not a model that reproduce the characteristics of all experimental pl spectra reported in the bibliography .
+ during the research of the origins of the _ p - si _ pl , some models about the nature of the pl were proposed ; cullis _ _ et al.__@xcite say that all these models could be reorganized in 6 mayor groups . |
7,728 | Suppose that you have an abstract for a scientific paper: we present an extension of general relativity in which an @xmath0 term la palatini is added to the usual metric einstein - hilbert lagrangian . expressing the theory in a dynamically equivalent scalar - tensor form ,
we show that it can pass the solar system observational tests even if the scalar field is very light or massless .
applications to cosmology and astrophysics , and some exact solutions are discussed . .
And you have already written the first three sentences of the full article: a number of alternative theories of gravity have been proposed in the last decade in relation with the cosmic speedup problem . among them , @xmath0 theories have attracted special attention .
these theories have been mainly studied in the metric@xcite and in the palatini@xcite formalisms . to be in agreement with local tests of gravity
, the former case generically requires that the non - linear curvature terms represent a short - range , massive scalar degree of freedom ..
Please generate the next two sentences of the article | the latter introduces non - perturbative effects that severely constrain the kind of non - linear terms , ruling out infrared corrections . here
we present a hybrid combination@xcite of both approaches which exhibits interesting new features that allow to avoid the typical shortcomings of the pure metric and palatini @xmath0 theories . |
7,729 | Suppose that you have an abstract for a scientific paper: we construct a theory of particles moving in curved both momentum space and spacetime , being a generalization of relative locality .
we find that in order to construct such theory , with desired symmetries , including the general coordinate invariance , we have to use non local position variables .
it turns out that free particles move on geodesics and momentum dependent translations of relative locality are replaced with momentum dependent geodesic deviations . .
And you have already written the first three sentences of the full article: in the recent years the largely forgotten idea that momentum space may have a nontrivial geometric structure , known under the name of born reciprocity @xcite , has been revived in many different guises in the context of quantum gravity .
it was noticed in @xcite that there is a one - to - one correspondence between space - time noncommutativity , expected to be one of the features of quantum gravity , and nontrivial geometric structures in momentum space .
this general observation is supported by explicit calculations done in the context of gravity in 2 + 1 dimensions @xcite , @xcite ..
Please generate the next two sentences of the article | few years later it was realized that many nontrivial features of doubly special relativity class of theories @xcite , @xcite , @xcite can be conveniently described in terms of the geometry of de sitter momentum space @xcite .
relative locality @xcite , @xcite , @xcite is a theoretical framework that has its roots in born reciprocity . in this framework |
7,730 | Suppose that you have an abstract for a scientific paper: we perform a theoretical study of radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers .
this decay necessarily involves an electronic spin flip .
the intrinsic decay mechanism due to interband spin - flip dipole moment perpendicular to the monolayer plane , gives a rate about 1001000 times smaller than that of bright excitons .
however , we find that this mechanism also introduces an energy splitting due to a local field effect , and the whole oscillator strength is contained in the higher - energy component , while the lowest - energy state remains dark and needs an extrinsic spin - flip mechanism for the decay .
rashba effect due to a perpendicular electric field or a dielectric substrate , gives a negligible radiative decay rate ( about @xmath0 times slower than that of bright excitons ) .
spin flip due to zeeman effect in a sufficiently strong in - plane magnetic field can give a decay rate comparable to that due to the intrinsic interband spin - flip dipole . .
And you have already written the first three sentences of the full article: transition metal dichalcogenides ( tmdcs ) are layered materials with the chemical composition mx@xmath1 , where m is a transition metal element ( such as molybdenum or tungsten ) , and x is a chalcogen ( sulfur , selenium , or tellurium ) .
the interest to semiconducting tmdcs has been sparked by the recent discovery of the monolayer mos@xmath1 being a direct - gap semiconductor , in contrast to its bulk indirect - gap counterpart @xcite .
atomically thin tmdc monolayers can be extracted from bulk crystals by exfoliation , similarly to graphene @xcite , or grown by molecular beam epitaxy or chemical vapor deposition @xcite ..
Please generate the next two sentences of the article | the optical gap in the visible light range @xcite and tightly bound excitons @xcite , make them quite promising for optical applications @xcite .
a unique feature of tmdcs is the so - called spin - valley locking @xcite . |
7,731 | Suppose that you have an abstract for a scientific paper: we report the discovery of x - ray quasi - periodic oscillations ( qpos ) at frequencies of 3 - 4 mhz from a transient ultraluminous x - ray source ( ulx ) in m82 .
the qpos are strong and broad and appear with weak or absent red noise , and are detected only in chandra observations when the source is brighter than @xmath0 .
the qpo behavior is similar to the type a - i qpos found in xte j1550@xmath1564 , which is a subclass of low frequency qpos with properties in between type a and b. therefore , we identify the qpos in as of type a or b , and rule out the possibility of type c. with this identification , the mass of the black hole in can be inferred as in the range of 12,000 - 43,000 solar masses by scaling the qpo frequency to that of the type a / b qpos in stellar mass black holes .
cool disk emission is detected in one chandra observation , and the disk inner radius suggests a similar black hole mass range .
black holes of such a high mass are able to produce an energy output in a manner similar to by accreting from the interstellar medium directly . .
And you have already written the first three sentences of the full article: ultraluminous x - ray sources ( ulxs ) are variable x - ray sources which are not coincident with the nucleus of the galaxy and exhibit luminosities over the eddington limit of a 20 @xmath2 black hole ( @xmath3 ) assuming isotropic emission .
they are too bright to be powered by accretion onto stellar mass black holes like galactic black hole binaries ( bhbs ) and are thus candidates of intermediate mass black holes ( imbhs ) . however ,
if the radiation is super - eddington or beamed along the line of sight , imbhs are not required @xcite ..
Please generate the next two sentences of the article | modeling the x - ray spectra of ulxs could shed light on their masses .
for example , the temperature and size of the accretion disk can be used to weigh the central compact object @xcite . however , |
7,732 | Suppose that you have an abstract for a scientific paper: the impact of an external electric field on the spin relaxation in a disordered , two - dimensional electron system is studied within the framework of a field - theoretical formulation .
generalized bloch - equations for the diffusion and the decay of an initial magnetization are obtained .
the equations are applied to the investigation of spin relaxation processes in an electric field . .
And you have already written the first three sentences of the full article: in recent years much attention has been paid to the emerging field of spintronics in semiconductor physics .
much of the interest in this field is stimulated by the spin - field - effect transistor proposed by datta and das @xcite . in this proposal
the rashba spin - orbit interaction is used to manipulate the charge transfer through a transistor like device by controlling the electron spin ..
Please generate the next two sentences of the article | the rashba interaction , which is the conventional spin - orbit interaction with a constant electric field , affects the electron spin like a momentum dependent magnetic field . in practice
the realization of the proposal by datta and das has proven to be a challenging task . |
7,733 | Suppose that you have an abstract for a scientific paper: we revisit the medium - induced coherent radiation associated to _ hard _ and _ forward _ ( small angle ) scattering of an energetic parton through a nuclear medium .
we consider all @xmath0 hard forward processes ( @xmath1 , @xmath2 , @xmath3 and @xmath4 ) , and derive the energy spectrum of induced coherent radiation rigorously to all orders in the opacity expansion and for the specific case of a coulomb scattering potential .
we obtain a simple general formula for the induced coherent spectrum , which encompasses the results corresponding to previously known special cases . .
And you have already written the first three sentences of the full article: the theory of medium - induced gluon radiation has received a lot of attention over the last twenty years , as it became clear that parton energy loss is most likely responsible for the quenching of large @xmath5 hadrons and jets in heavy - ion collisions , first observed at rhic @xcite and then at the lhc @xcite .
multiple scatterings of a high - energy parton propagating in a medium applies more naturally to the former case .
] of length @xmath6 induce the emission of gluons , a process occurring on a typical time @xmath7 , where @xmath8 is the light - cone momentum of the radiated gluon , and @xmath9 ..
Please generate the next two sentences of the article | it is useful to recall the three regimes identified in @xcite depending on the value of the gluon formation time @xmath10 ( for a more detailed discussion in qed and in qcd , see @xcite ) : * * bethe heitler , @xmath11 * , where @xmath12 is the parton mean free path in the medium . in this regime , _ each _ scattering center acts as an independent source of radiation .
the induced gluon spectrum is thus proportional to the ( bethe - heitler ) gluon spectrum induced by a _ |
7,734 | Suppose that you have an abstract for a scientific paper: we provide a complete work - flow , based on the language of quantum information theory , suitable for processing data for the purpose of pattern recognition .
the main advantage of the introduced scheme is that it can be easily implemented and applied to process real - world data using modest computation resources . at the same time
it can be used to investigate the difference in the pattern recognition resulting from the utilization of the tensor product structure of the space of quantum states .
we illustrate this difference by providing a simple example based on the classification of 2d data .
* keywords : * pattern discrimination ; quantum computing ; entanglement of data .
And you have already written the first three sentences of the full article: quantum machine learning aims at merging the methods from quantum information processing and computer engineering to provide new solutions for problems in the areas of pattern recognition and image understanding @xcite . from one side the research in this area
is focused at applying the methods of quantum information processing for solving problems related to classification and clustering in signal processing . from the other perspective the methods for classification developed in computer engineering are used to find solutions for problems like quantum state discrimination @xcite , which are tightly connected with the recent developments in quantum cryptography .
the aim of the paper is to present a complete work - flow , based on the mathematical formalism used in quantum information theory , suitable for processing data for the purpose of pattern recognition ..
Please generate the next two sentences of the article | the main goal is to introduce the method for describing classical data using entangled quantum states and to investigate the difference between the entangled and the separable representations of states .
the presented work - flow enable the processing of real - world data as it can be implemented and executed on standard desktop computers . |
7,735 | Suppose that you have an abstract for a scientific paper: with nonrelativistic qcd factorization , we calculate the @xmath0 prompt production at hadron colliders at next - to - leading order in @xmath1 .
in addition to the color - singlet contribution , color - octet channels ( especially the p - wave channel ) up to @xmath2 are all considered . aside from direct production , the feed - down contributions from higher excited s - wave and p - wave @xmath3 states to @xmath0 production are also included .
we use the potential model estimates as input for color - singlet long - distance matrix elements ( ldmes ) . while for color - octet contributions
, we find they can be approximately described by three ldmes : @xmath4})\rangle}$ ] , @xmath5})\rangle}$ ] and @xmath6})\rangle}$ ] . by fitting the tevatron data we can determine some linear combinations of these ldmes , and then use them to predict @xmath0 production at the lhc .
our predictions are consistent with the new experimental data of cms and lhcb . .
And you have already written the first three sentences of the full article: the study of heavy quarkonium production is particularly interesting because it may provide decisive information in understanding hadronization of heavy quarks and gluons in qcd .
the most widely accepted theory to describe heavy quarkonium production at present is nonrelativistic qcd ( nrqcd ) factorization @xcite , in which the production is factorized into perturbative calculable short - distance coefficients and nonperturbative ( and universal ) long - distance matrix elements ( ldmes ) . as short - distance coefficients can be expanded in strong - coupling @xmath7 and each ldme has a definite power in @xmath8 ( the velocity of heavy quarks in the rest frame of heavy quarkonium ) , nrqcd factorization gives predictions by double expansion in @xmath7 and @xmath9 .
nrqcd factorization is efficient such that in principle only a finite number of universal parameters , which can be determined by using some known experimental data , are involved with required precision in predicting other production processes ..
Please generate the next two sentences of the article | although a complete proof of factorization is still lacking , at least it holds up to next - to - next - to - leading order in @xmath7 @xcite .
based on nrqcd factorization , charmonium production in hadron colliders has been studied extensively in recent years@xcite . specifically , for @xmath10 hadroproduction , it is found that all data at large @xmath11 , including both yield and polarization , can be well described by nrqcd factorization if one chooses a large @xmath12 and a small @xmath13 @xcite ( see also refs.@xcite ) . |
7,736 | Suppose that you have an abstract for a scientific paper: i study non - radiative cooling of x - ray emitting gas via heat conduction along magnetic field lines inside magnetic flux loops in cooling flow clusters of galaxies .
i find that such heat conduction can reduce the fraction of energy radiated in the x - ray band by a factor of @xmath0 .
this non - radiative cooling joins two other proposed non - radiative cooling processes , which can be more efficient .
these are mixing of cold and hot gas , and heat conduction initiated by magnetic fields reconnection between hot and cold gas .
these processes when incorporated into the moderate cooling flow model lead to a general cooling flow model with the following ingredients .
( 1 ) cooling flow does occur , but with a mass cooling rate @xmath1 times lower than in old ( @xmath1 years ago ) versions of the cooling flow model .
namely , heating occurs such that the effective age of the cooling flow is much below the cluster age , but the heating ca nt prevent cooling altogether .
( 2 ) the cooling flow region is in a non - steady state evolution .
( 3 ) non - radiative cooling of x - ray emitting gas can bring the model to a much better agreement with observations .
( 4 ) the general behavior of the cooling flow gas , and in particular the role played by magnetic fields , make the intracluster medium in cooling flow clusters similar in some aspects to the active solar corona . .
And you have already written the first three sentences of the full article: recent _ chandra _ and _ xmm - newton _ observations of cooling flow ( cf ) clusters of galaxies have lead to a shower of papers examining reheating processes of the intracluster medium ( icm ) , which together with pre-_chandra _ and xmm - newton reheating papers make a long list of papers with different ideas ( e.g. , binney & tabor 1995 ; tucker & david 1997 ; ciotti & ostriker 2001 ; david et al .
2001 ; quilis , bower , & balogh 2001 ; brggen , m. & kaiser 2001 ; ruszkowski & begelman 2002 ; nulsen et al .
2002 ; fabian 2003 ; fabian et al . 2003 ; binney 2003 ; mathews et al . 2003.
Please generate the next two sentences of the article | ; for more references see peterson et al .
these recent observations , although in contradiction ( fabian 2003 ) with the cluster - cf models of 10 years ago ( fabian 1994 ) , are compatible with models having low mass cooling rates ( see binney 2003 , for why the new results are not a surprise ) , such as in the moderate cf model ( soker et al . |
7,737 | Suppose that you have an abstract for a scientific paper: the casimir effect in a dispersive and absorbing multilayered system is considered adopting the ( net ) vacuum - field pressure point of view to the casimir force . using the properties of the macroscopic field operators appropriate for absorbing systems and a convenient compact form of the green function for a multilayer ,
a straightforward and transparent derivation of the casimir force in a lossless layer of an otherwise absorbing multilayer is presented .
the resulting expression in terms of the reflection coefficients of the surrounding stacks of layers is of the same form as that obtained by zhou and spruch for a purely dispersive multilayer using the ( surface ) mode summation method [ phys .
rev .
a * 52 * , 297 ( 1995 ) ] . owing to the recursion relations which the generalized fresnel coefficients satisfy ,
this result can be applied to more complex systems with planar symmetry .
this is illustrated by calculating the casimir force on a dielectric ( metallic ) slab in a planar cavity with realistic mirrors .
also , a relationship between the casimir force and energy in two different layers is established . .
And you have already written the first three sentences of the full article: originally , the casimir effect was predicted as a feature of the electromagnetic field between two neutral ideally conducting plates and consisted in the appearance of an attractive force between the plates .
the force is due to the change of the zero - point energy of the field in the confined space @xcite . in this special case , however , the casimir force can also be viewed as the long - range van der waals force @xcite .
it becomes appreciable in the submicron and rapidly increases in the nanometer range ..
Please generate the next two sentences of the article | as such , it may strongly affect processing in nanotechnology as well as functioning of micro- and nanomachines and devices @xcite .
clearly , these new developments pose the problem of realistic calculations of the casimir force on objects in complex enviroments . |
7,738 | Suppose that you have an abstract for a scientific paper: we show that the significantly different effective temperatures ( @xmath0 ) achieved by the luminous blue variable ag carinae during the consecutive visual minima of 19851990 ( @xmath1 k ) and 20002001 ( @xmath2 k ) place the star on different sides of the bistability limit , which occurs in line - driven stellar winds around @xmath3 k. decisive evidence is provided by huge changes in the optical depth of the lyman continuum in the inner wind as @xmath0 changes during the s dor cycle .
these changes cause different fe ionization structures in the inner wind .
the bistability mechanism is also related to the different wind parameters during visual minima : the wind terminal velocity was 23 times higher and the mass - loss rate roughly two times smaller in 19851990 than in 20002003 .
we obtain a projected rotational velocity of @xmath4 during 19851990 which , combined with the high luminosity ( @xmath5 ) , puts ag car extremely close to the eddington limit modified by rotation ( @xmath6 limit ) : for an inclination angle of @xmath7 , @xmath8 for @xmath9 .
based on evolutionary models and mass budget , we obtain an initial mass of @xmath10 and a current mass of @xmath11 for ag car . therefore , ag car is close to , if not at , the @xmath6 limit during visual minimum .
assuming @xmath12 , we find that @xmath13 decreases from 0.93 to 0.72 as ag car expands toward visual maximum , suggesting that the star is not above the eddington limit during maximum phases . .
And you have already written the first three sentences of the full article: albeit rare , massive stars are the main contributors to the input of ionizing photons , energy , and momentum into the interstellar medium , and are responsible for a significant fraction of the chemical enrichment of their host galaxy .
massive stars evolve on relatively short timescales ( a few @xmath14 years ) , and their evolution is strongly influenced by their strong mass loss and rotation ( e.g , * ? ? ?
tremendous advancement in the understanding of the evolution of massive stars has been achieved in recent decades @xcite . in particular.
Please generate the next two sentences of the article | , we now have insights into the effects of rotation on the evolution of massive stars @xcite .
the models predict the existence of a short - lived , transitional stage , usually referred to as the luminous blue variable ( lbv ) phase @xcite , during which the star has a high mass - loss rate ( @xmath15 @xmath16 ) . in the current picture of stellar evolution , |
7,739 | Suppose that you have an abstract for a scientific paper: in this paper , we introduce a framework of new mathematical representation of game theory , including static classical game and static quantum game . the idea is to find a set of base vectors in every single - player strategy space and to define their inner product so as to form them as a hilbert space , and then form a hilbert space of system state .
basic ideas , concepts and formulas in game theory have been reexpressed in such a space of system state .
this space provides more possible strategies than traditional classical game and traditional quantum game .
so besides those two games , more games have been defined in different strategy spaces .
all the games have been unified in the new representation and their relation has been discussed .
general nash equilibrium for all the games has been proposed but without a general proof of the existence . besides the theoretical description , ideas and technics from statistical physics , such as kinetics equation and thermal equilibrium can be easily incorporated into game theory through such a representation .
this incorporation gives an endogenous method for refinement of equilibrium state and some hits to simplify the calculation of equilibrium state .
the more privileges of this new representation depends on further application on more theoretical and real games . here
, almost all ideas and conclusions are shown by examples and argument , while , we wish , lately , we can give mathematical proof for most results .
key words : game theory , quantum game theory , quantum mechanics , statistical physics pacs : 02.50.le , 03.67.-a , 03.65.yz , 05.20.-y , 05.30.-d .
And you have already written the first three sentences of the full article: game theory@xcite is a subject used to predict the strategy of all players in a game .
the simplest game is static and non - cooperative game , which describe by payoff function @xmath0 , a linear mapping from strategy space @xmath1 to n - dimension real space @xmath2 . for a game in mixture strategy space , in which every player uses mixture strategy @xmath3 , a probability distribution on strategy set @xmath4
, nash theorem proves that there is always some mixture - strategy equilibrium points , on which no player has the willing to make an independent change ..
Please generate the next two sentences of the article | therefor , such equilibrium points can be regarded as a converged points ( or at least fixed points ) of the system , then as the end state of all players . on the other hand ,
quantum game theory@xcite has been proposed as a quantum version of game theory@xcite . |
7,740 | Suppose that you have an abstract for a scientific paper: we review and introduce new representations of tensor train decompositions for large - scale vectors , matrices , or low - order tensors .
we provide extended definitions of mathematical multilinear operations such as kronecker , hadamard , and contracted products , with their properties for tensor calculus .
then we introduce an effective low - rank tensor approximation technique called the tensor train ( tt ) format with a number of mathematical and graphical representations .
we also provide a brief review of mathematical properties of the tt format as a low - rank approximation technique . with the aim of breaking the curse - of - dimensionality in large - scale numerical analysis
, we describe basic operations on large - scale vectors and matrices in tt format .
the suggested representations can be used for describing numerical methods based on the tt format for solving large - scale optimization problems such as the system of linear equations and eigenvalue problems . .
And you have already written the first three sentences of the full article: multi - dimensional or multi - way data is prevalent nowadays , which can be represented by tensors .
an @xmath0th - order tensor is a multi - way array of size @xmath1 , where the @xmath2th dimension or mode is of size @xmath3 .
for example , a tensor can be induced by the discretization of a multivariate function @xcite . given a multivariate function @xmath4 defined on a domain @xmath5^n$ ].
Please generate the next two sentences of the article | , we can get a tensor with entries containing the function values at grid points .
for another example , we can obtain tensors based on observed data @xcite . |
7,741 | Suppose that you have an abstract for a scientific paper: we made near infrared multicolor imaging observations of a disk around herbig be star hd100546 using gemini / nici . k ( 2.2@xmath0 m ) , h@xmath1o ice ( 3.06@xmath0 m ) , and l(3.8@xmath0 m ) disk images were obtained and we found the 3.1@xmath0 m absorption feature in the scattered light spectrum , likely due to water ice grains at the disk surface .
we compared the observed depth of the ice absorption feature with the disk model based on @xcite including water ice photodesorption effect by stellar uv photons .
the observed absorption depth can be explained by the both disk models with / without photodesorption effect within the measurement accuracy , but slightly favors the model with photodesorption effects , implying that the uv photons play an important role on the survival / destruction of ice grains at the herbig ae / be disk surface . further improvement on the accuracy of the observations of the water ice absorption depth is needed to constrain the disk models . .
And you have already written the first three sentences of the full article: water ice is believed to play many important roles in the planet formation theories .
for example , ice enhances the surface density of solid material in the cold outer part of a protoplanetary disk , which promotes the formation of massive cores of gaseous planets ( e.g. , * ? ? ? * ) .
thus the ice sublimation / condensation front called snowline , is considered to be the boundary of the forming regions of the terrestrial and jovian planets ..
Please generate the next two sentences of the article | snowline is also suggested as a possible forming site of the planetesimals @xcite .
furthermore , icy planetesimals or comets may bring water to the earth ( e.g. , * ? ? ? |
7,742 | Suppose that you have an abstract for a scientific paper: we present analysis of the excitation spectrum for a 2 component quasi2d bose einstein condensate .
we study how excitations change character across the miscible to immiscible phase transition .
we find that the bulk excitations are typical of a single - component bec with the addition of interface bending excitations .
we study how these excitations change as a function of the interaction strength . .
And you have already written the first three sentences of the full article: ultracold atoms provide an excellent forum to study complex quantum mechanical behavior .
an example is the superfluid to mott insulator transition @xcite , where experimental efforts have imaged this as a quantum phase transition at the single atom level @xcite .
a quantum phase transition is a fundamental change in the ground state as a parameter is altered , in the superfluid - mott insulator example the parameter is lattice depth . near this quantum phase transition the temperature dependence of superfluidity and quantum criticality has been studied @xcite ..
Please generate the next two sentences of the article | another system in ultracold atoms , which exhibits a quantum phase transition , is the 2 component bose einstein condensate ( bec ) , where by tuning the interactions between the components the gas can change from a miscible to an immiscible phase , as has been experimentally demonstrated in rb @xcite .
theoretical studies showed that if @xmath0 is greater ( less ) than zero , the gas is miscible ( immiscible ) @xcite . here |
7,743 | Suppose that you have an abstract for a scientific paper: the recent progress in the qcd theory of diffractive dis ( ddis ) is reviewed .
we place emphasis on pqcd scales , diffractive factorization breaking , jet and charm production and new fundamental observables which are becoming accessible with the leading proton spectrometers ( lps ) of zeus and h1 .
# 1#2#3#4#1 * # 2 * , # 3 ( # 4 ) # 1@xmath0 # 1@xmath0 .
And you have already written the first three sentences of the full article: this is an opening talk on diffraction at dis97 and we start with definitions .
the longitudinal ( l ) and the two transverse ( t ) polarizations of the exchanged photon define the four components @xmath1 ( @xmath2 and @xmath3 ) in the expansion q^2xd^(5)(epepx ) dq^2dxdm^2dp_^2d = _ em \{(1-y+12y^2)d_t^d(3)+ ( 1-y)d_l^(3 ) .
+ ( 1-y)2d_tt^d(3)+(2-y ) d_lt^d(3)}/dm^2dp_^2d[eq:1.1 ] where @xmath4 is the diffractive mass , @xmath5 is the @xmath6 momentum transfer , and @xmath7 is the angle between the @xmath8 and @xmath6 planes . in the charged current ( cc ).
Please generate the next two sentences of the article | ddis there are also the c- and p - odd , @xmath9 and @xmath10 , terms @xcite .
each @xmath11 defines a set of * dimensionless * diffractive structure functions @xmath12 , = _ |
7,744 | Suppose that you have an abstract for a scientific paper: a survey measuring quasar polarization vectors has been started in two regions towards the north and south galactic poles . here , we review the discovery of significant correlations of orientations of polarization vectors over huge angular distances .
we report new results including a larger sample of the quasars confirming the existence of coherent orientations at redshifts @xmath0 . .
And you have already written the first three sentences of the full article: large scale alignments of quasar polarization vectors were uncovered by hutsemkers ( 1998 ) , looking at a sample of 170 qsos selected from the litterature and confirmed later on a larger sample ( hutsemkers & lamy 2001 ) .
the departure to random orientations was found at significance levels small enough to merit deeper investigations .
moreover , these alignments seemed to come from high redshift regions , implying that the underlying mechanism might cover physical distances of giga parsecs . a large survey of linear polarization.
Please generate the next two sentences of the article | was then started , with the long - term goal to characterize better the polarization properties of quasars , and a short - term goal to investigate the reality of the alignments .
this work gives a preliminary analysis of the alignment effect for a total sample of 355 quasars , comprising new polarization measurements from observing runs between 2001 - 2003 and a new comprehensive compilation from the litterature . |
7,745 | Suppose that you have an abstract for a scientific paper: the importance of lattice gauge field interpolation for our recent non - perturbative formulation of chiral gauge theory is emphasized .
we illustrate how the requisite properties are satisfied by our recent four - dimensional non - abelian interpolation scheme , by going through the simpler case of @xmath0 gauge fields in two dimensions . .
And you have already written the first three sentences of the full article: in every major scenario for physics above the @xmath1 scale non - perturbative chiral gauge theory dynamics is expected to play an important role , yet our understanding of this dynamics is very limited .
recently we proposed a non - perturbative formulation of chiral gauge theory on the lattice , in the hope that the important features of these theories will be calculable in future computer simulations @xcite .
we briefly review it here , focussing on a lattice gauge field interpolation procedure which is the crucial feature of our construction ..
Please generate the next two sentences of the article | the fermions are taken to live on a euclidean lattice with spacing @xmath2 .
fermion doublers are eliminated by the rome group method of using a gauge non - invariant wilson term @xcite . |
7,746 | Suppose that you have an abstract for a scientific paper: the interaction of a single - mode field with both a weak kerr medium and a parametric nonlinearity in an intrinsically nonlinear optomechanical system is studied . the nonlinearities due to the optomechanical coupling and kerr - down conversion lead to the bistability and tristability in the mean intracavity photon number .
also , our work demonstrates that the lower bound of the resolved sideband regime and the minimum attainable phonon number can be less than that of a bare cavity by controlling the parametric nonlinearity and the phase of the driving field .
moreover , we find that in the system under consideration the degree of entanglement between the mechanical and optical modes is dependent on the two stability parameters of the system . for both cooling and entanglement
, while parametric nonlinearity increases the optomechanical coupling , the weak kerr nonlinearity is very useful for extending the domain of the stability region to the desired range in which the minimum effective temperature and maximal entanglement are attainable .
also , as shown in this paper , the present scheme allows to have significant entanglement in the tristable regime for the lower and middle branches which makes the current scheme distinct from the bare optomechanical system . .
And you have already written the first three sentences of the full article: considerable interest has recently been focused on the optomechanical system as an excellent candidate for studying the transition of a macroscopic degree of freedom from the classical to the quantum regime .
this system also provides novel routes for practical applications such as detection and interferometry of gravitational waves@xcite and quantum limited displacement sensing @xcite .
the standard and simplest setup of this system is a fabry - perot cavity in which one of the mirrors is much lighter than the other , so that it can move under the effect of the radiation pressure force ..
Please generate the next two sentences of the article | state - of - the - art technology allows experimental demonstration of cooling of the vibrational mode of the mechanical oscillator to its ground state@xcite and strong optomechanical coupling between the vibrational mode of the mechanical oscillator and cavity field@xcite .
this coupling is intrinsically nonlinear since the length of the cavity depends upon the intensity of the field in analogous way to the optical length of a kerr material@xcite . |
7,747 | Suppose that you have an abstract for a scientific paper: this paper investigates how multiuser dimensions can effectively be exploited for target degrees of freedom ( dof ) in interfering broadcast channels ( ibc ) consisting of @xmath0-transmitters and their user groups .
first , each transmitter is assumed to have a single antenna and serve a singe user in its user group where each user has receive antennas less than @xmath0 . in this case , a @xmath0-transmitter single - input multiple - output ( simo ) interference channel ( ic ) is constituted after user selection . without help of multiuser diversity
, @xmath1 interfering signals can not be perfectly removed at each user since the number of receive antennas is smaller than or equal to the number of interferers . only with proper user selection , non -
zero dof per transmitter is achievable as the number of users increases . through geometric interpretation of interfering channels ,
we show that the multiuser dimensions have to be used first for reducing the dof loss caused by the interfering signals , and then have to be used for increasing the dof gain from its own signal .
the sufficient number of users for the target dof is derived .
we also discuss how the optimal strategy of exploiting multiuser diversity can be realized by practical user selection schemes .
finally , the single transmit antenna case is extended to the multiple - input multiple - output ( mimo ) ibc where each transmitter with multiple antennas serves multiple users .
multiuser diversity , degrees of freedom , interference alignment measure , interfering broadcast channel .
And you have already written the first three sentences of the full article: interference is a major performance - limiting factor in modern wireless communication systems .
many interference mitigation strategies have been proposed to improve network spectral efficiency . by allowing partial or full cooperation among interfering base stations ,
interference can effectively be managed and spectral efficiency can be improved ..
Please generate the next two sentences of the article | joint beamforming @xcite and network mimo ( or multicell processing ) @xcite among base stations have been shown to be effective interference mitigation techniques . however ,
if cooperation among transmitters is not allowed , orthogonal multiple access has been a traditional solution to interference . in a @xmath0-user single - input single - output ( siso ) interference channel ( ic ) , for example |
7,748 | Suppose that you have an abstract for a scientific paper: we investigate quantum impurity problems , where a local magnetic moment is coupled to the spin density of a bosonic environment , leading to bosonic versions of the standard kondo and anderson impurity models . in a physical situation
, these bosonic environments can correspond either to deconfined spinons in certain classes of z@xmath0 frustrated antiferromagnets , or to particles in a multicomponent bose gase ( in which case the spin degree of freedom is attributed to hyperfine levels ) . using renormalization group techniques
, we establish that our impurity models , which feature an exchange interaction analogous to kondo impurities in fermi liquids , allow the flow towards a stable strong - coupling state . since the low - energy bosons live around a single point in momentum space , and
there is no fermi surface , an impurity quantum phase transition occurs at intermediate coupling , separating screened and unscreened phases .
this behavior is qualitatively different from previously studied spin - isotropic variants of the spin - boson model , which display stable intermediate - coupling fixed points and no screening . .
And you have already written the first three sentences of the full article: the investigation of quantum phase transitions in strongly correlated electronic systems has been an active field of research during the last two decades.@xcite recently , there has been growing interest in so - called impurity quantum phase transitions
these correspond to qualitative changes in the ground - state properties of discrete degrees of freedom ( a spin @xmath1 in the simplest case ) upon changing their couplings to an external environment . on the one hand ,
impurity quantum phase transitions can be realized , e.g. , in mesoscopic systems , such as quantum dot devices , which provide the high tunability required to access the transition point . on the other hand.
Please generate the next two sentences of the article | , the study of impurity problems is motivated through the dynamical mean - field theory@xcite ( dmft ) , which maps lattice models of strongly correlated electrons assuming a momentum - independent self energy onto effective self - consistent impurity models . in this language ,
certain bulk quantum phase transition correspond to impurity transitions in anderson or kondo - type models . |
7,749 | Suppose that you have an abstract for a scientific paper: in this paper we study the shape characteristics of a polymer chain in a good solvent using a mesoscopic level of modelling .
the dissipative particle dynamics simulations are performed in the @xmath0 space at a range of chain lengths @xmath1 .
the scaling laws for the end - to - end distance and gyration radius are examined first and found to hold for @xmath2 yielding reasonably accurate value for the flory exponent @xmath3 . within the same interval of chain lengths , the asphericity , prolateness , size ratio and other shape characteristics of the chain are found to become independent of @xmath1 .
their mean values are found to agree reasonably well with the respective theoretical results and lattice monte carlo simulations .
broad probability distributions for the shape characteristics are found resembling in form the results of lattice monte carlo simulations . by means of analytic fitting of these distributions the most probable values for the shape characteristics
are found to supplement their mean values .
_ keywords _ : polymer , scaling , dissipative particle dynamics .
And you have already written the first three sentences of the full article: universal scaling laws for the dimensional properties of flexible polymer chain in a good solvent , such as the end - to - end distance @xmath4 and the gyration radius @xmath5 , are well explained and understood since the groundbreaking studies by de gennes and des cloizeaux @xcite .
it was found that both properties scale as @xmath6 for large enough numbers of monomers @xmath1 , where the exponent @xmath3 is universal and depends on the dimension of space @xmath7 only . besides that
, the probability distribution @xmath8 is also examined in both asymoptotic regimes of small and large values of @xmath4 based on the number of chain conformations @xcite ..
Please generate the next two sentences of the article | similar arguments allowed lhuillier to suggest an heuristic form for the probability distribution @xmath9 as well @xcite .
as far as the scaling laws are also valid for a number of other characteristics of the polymer chain , the universality and scaling properties are often treated as identical concepts . |
7,750 | Suppose that you have an abstract for a scientific paper: we compare two effective phonon theories , which have both been applied recently to study heat conduction in anharmonic lattices .
in particular , we study the temperature dependence of the thermal conductivity of fermi - pasta - ulam @xmath0 model via the debye formula , showing the equivalence of both approaches .
the temperature for the minimum of the thermal conductivity and the corresponding scaling behavior are analytically calculated , which agree well with the result obtained from non - equilibrium simulations .
we also give quantum corrections for the thermal conductivity from quantum self - consistent phonon theory .
the vanishing behavior at low temperature regime and the existence of an _ umklapp _ peak are qualitatively consistent with experimental studies .
the study of heat conduction is very important from both theoretical and experimental point of view .
a traditional phenomenological approach to understand the thermal properties in solids is the debye formula given by @xmath1 where @xmath2 is the thermal conductivity , @xmath3 , @xmath4 , @xmath5 are the specific heat , the phonon group velocity and the phonon mean free path of mode @xmath6 , respectively . in spite of its successfulness for qualitative explanation of heat conduction in dielectrics ,
quantitative predictions are hard to make from a microscopic viewpoint .
recently , an increasing study of heat conduction in low dimensional hamiltonian models may shed light on its microscopic understanding @xcite .
however , only a few integrable models can be solved rigourously @xcite .
generally one has to rely on numerical simulations for non - integrable models .
thus it would be worthy to revisit the traditional kinetic approach by incorporating some microscopic consideration for the low dimensional non - integrable lattice systems .
according to the debye formula , the thermal transport process in a nonlinear lattice is intrinsically relative to its dispersion relation and relaxation of normal modes (....
And you have already written the first three sentences of the full article: in this section we will compare the scpt ( see , e.g. , @xcite ) and ept @xcite . to make this concrete
, we mainly focus on the temperature dependence of the physical quantities of the fermi - pasta - ulam @xmath0 ( fpu-@xmath0 ) model , which is a classic example to study heat conduction .
the hamiltonian of the fpu-@xmath0 model is given by @xmath13 within the scp approximation , the hamiltonian is approximated by a trial hamiltonian @xmath14 where the effective harmonic coupling constant @xmath15 is given by eq . in the appendix with the boltzmann constant @xmath16 ..
Please generate the next two sentences of the article | note that @xmath15 is temperature dependent , which stems from the existence of nonlinearity in the system .
the dispersion relation of effective phonons corresponding to the effective hamiltonian can be written in the form @xmath17 it is then straightforward to calculate the dimensionless nonlinearity @xmath10 and the specific heat @xmath18 from gaussian averages of scpt , which yields @xmath19 @xmath20 the derivation of the effective phonon spectrum is based on the generalized equipartition theorem , @xmath21 where the bracket @xmath22 stands for a thermal average in the canonical ensemble and @xmath23 denotes the fourier transform of the coordinate @xmath24 . |
7,751 | Suppose that you have an abstract for a scientific paper: after the positive detection by of hard x - ray radiation up to @xmath080 kev in the coma cluster spectrum , we present evidence for nonthermal emission from a2256 in excess of thermal emission at a 4.6@xmath1 confidence level .
in addition to this power law component , a second nonthermal component already detected by could be present in the x - ray spectrum of the cluster , not surprisingly given the complex radio morphology of the cluster central region .
the spectral index of the hard tail detected by the pds onboard is marginally consistent with that expected by the inverse compton model .
a value of @xmath2 is derived for the intracluster magnetic field of the extended radio emission in the northern regions of the cluster , while a higher value of @xmath3 could be present in the central radio halo , likely related to the hard tail detected by . .
And you have already written the first three sentences of the full article: nonthermal hard x - ray ( hxr ) radiation has been detected for the first time in the coma cluster by ( fusco - femiano 1999 ) and _ rxte _ ( rephaeli , gruber & blanco 1999 ) , while marginal evidence is reported for a2199 ( kaastra 1999 ) .
these observations are only first steps towards assessing the general existence of this new component in the x - ray spectra of clusters of galaxies .
the search for nonthermal emission in more clusters is of high importance as it will allow to derive additional informations on the physical conditions of the intracluster medium ( icm ) environment , which can not be obtained by studying the thermal plasma emission only ..
Please generate the next two sentences of the article | various interpretations of the hxr emission have been presented since its discovery in the coma cluster spectrum .
the most direct explanation is inverse compton ( ic ) scattering of cosmic microwave background ( cmb ) photons by the relativistic electrons responsible of the extended radio emission present in the central region of coma ( willson 1970 ) . |
7,752 | Suppose that you have an abstract for a scientific paper: we present high - resolution maps of stars , dust , and molecular gas in a strongly lensed submillimeter galaxy ( smg ) at @xmath0 .
hatlas j114637.9@xmath1001132 is selected from the _
herschel_-astrophysical terahertz large area survey ( h - atlas ) as a strong lens candidate mainly based on its unusually high 500 @xmath2 m flux density ( @xmath3300 mjy ) .
it is the only high - redshift _ planck _ detection in the 130 deg@xmath4 h - atlas phase - i area .
keck adaptive optics images reveal a quadruply imaged galaxy in the @xmath5-band while the submillimeter array and the jansky very large array show doubly imaged 880 @xmath2 m and co(1@xmath60 ) sources , indicating differentiated distributions of the various components in the galaxy . in the source plane ,
the stars reside in three major kpc - scale clumps extended over @xmath31.6 kpc , the dust in a compact ( @xmath31 kpc ) region @xmath33 kpc north of the stars , and the cold molecular gas in an extended ( @xmath37 kpc ) disk @xmath35 kpc northeast of the stars .
the emission from the stars , dust , and gas are magnified by @xmath317 , @xmath38 , and @xmath37 times , respectively , by four lensing galaxies at @xmath7 .
intrinsically , the lensed galaxy is a warm ( @xmath8 k ) , hyper - luminous ( @xmath9 @xmath10 ; sfr @xmath11 @xmath12 yr@xmath13 ) , gas - rich ( @xmath14 ) , young ( @xmath15 myr ) , and short - lived ( @xmath16 myr ) starburst . with physical properties similar to unlensed @xmath17 smgs , hatlas j114637.9@xmath1001132 offers a detailed view of a typical smg through a powerful cosmic microscope . .
And you have already written the first three sentences of the full article: bright submillimeter - selected galaxies ( smgs * ? ? ?
* ) provide a powerful probe into the distant universe .
thanks to the negative @xmath5-correction in the rayleigh - jeans tail of the dust thermal emission , flux limited submillimeter surveys with 850 @xmath2 m flux density @xmath18 mjy reach an almost uniform integrated infrared ( ir ) luminosity limit across a wide redshift range ( @xmath19 ) and yield a galaxy population mostly at redshifts between @xmath20 @xcite . with star formation rates ( sfrs ) of @xmath21 @xmath22.
Please generate the next two sentences of the article | yr@xmath13 , the smgs are the most intense star - forming galaxies , despite their inevitably short - lived nature ( lifetime @xmath23 0.1 gyr ) .
although such intense starburst systems are extremely rare in the local universe , smgs and the lyman break galaxies may contribute equally to the comoving sfr density at @xmath24 @xcite . |
7,753 | Suppose that you have an abstract for a scientific paper: * establishing the relation between the ubiquitous antiferromagnetism in the non - superconducting parent compounds of unconventional superconductors and their superconducting phase is believed to be important for the understanding of the complex physics in these materials .
going from the bulk systems to thin films strongly affects the phase diagram of unconventional superconductors . for fe@xmath0te , the parent compound of the fe@xmath0se@xmath1te@xmath2 superconductors , bulk sensitive neutron diffraction has revealed an in - plane oriented bicollinear antiferromagnetic structure . here ,
we show by spin - resolved scanning tunneling microscopy that on the surfaces of bulk fe@xmath0te , as well as on thin films grown on the topological insulator bi@xmath3te@xmath4 , the spin direction is canted both away from the surface plane and from the high - symmetry directions of the surface unit cell , while keeping the bicollinear magnetic structure .
our results demonstrate that the magnetism at the fe - chalcogenide surface markedly deviates from a simple in - plane oriented bicollinear antiferromagnetic structure , which implies that the pairing at the surface of the related superconducting compounds might be different from that in the bulk .
* the physics of many transition metal oxides ( tmo ) is dominated by strong electronic correlations which leads to exotic ground states and excitations with a dominant role of electronic charge and spin degrees of freedom .
for example , for cuprate based high temperature superconductors ( htscs ) there have been growing evidence that charge and spin density wave - like states are inherent to these materials with a significant impact on the corresponding excitation spectrum @xcite .
indeed , spin and charge ordering appear to be a key feature for understanding the physics of htscs @xcite .
furthermore , among the correlated electron systems the recently discovered iron - based superconductors @xcite are of particular interest for the understanding of....
And you have already written the first three sentences of the full article: * sp - stm on the surface of fe@xmath0te bulk and thin films . * in spin - polarized scanning tunneling microscopy
the tunneling current depends on the relative orientation of the tip magnetization and the local spin direction of the sample .
the total tunneling current @xmath15 can be described by @xmath16 , where @xmath17 is the spin - averaged tunneling current and @xmath18 is the spin - polarized tunneling current which is proportional to the product of the spin - polarization @xmath19 of tip and @xmath20 of the sample , @xmath21 . here.
Please generate the next two sentences of the article | , @xmath22 is the angle between the spin direction of the tip and the sample . in general
, fe - coated w - tips have a magnetization direction perpendicular to the tip axis and thus parallel to the surface of the sample . |
7,754 | Suppose that you have an abstract for a scientific paper: in the framework of the ginzburg - landau approach , we present a self - consistent theory of specific soliton states in mesoscopic ( thin - walled ) two - band - superconducting cylinders in external parallel magnetic fields .
such states arise in the presence of `` josephson - type '' interband coupling , when phase winding numbers are different for each component of the superconducting order parameter .
we evaluate the gibbs free energy of the sysyem up to second - order terms in a certain dimensionless parameter @xmath0 , where @xmath1 and @xmath2are the magnetic and kinetic inductance , respectively .
we derive the complete set of exact soliton solutions .
these solutions are thoroughly analyzed from the viewpoint of both local and global ( thermodynamic ) stability .
in particular , we show that rotational - symmetry - breaking caused by the formation of solitons gives rise to a zero - frequency rotational mode .
although soliton states prove to be thermodynamically metastable , the minimal energy gap between the lowest - lying single - soliton states and thermodynamically stable zero - soliton states can be much smaller than the magnetic gibbs free energy of the latter states , provided that intraband `` penetration depths '' differ substantially and interband coupling is weak .
the results of our investigation may apply to a wide class of mesoscopic doubly - connected structures exhibiting two - band superconductivity . .
And you have already written the first three sentences of the full article: the subject of this paper is a self - consistent theory of specific soliton states that were originally predicted in ref .
@xcite and reportedly observed experimentally.@xcite without any doubt , these states can be regarded as a hallmark of two - band superconductivity in mesoscopic doubly - connected samples .
indeed , owing to the emergence of additional degrees of freedom of the order parameter , the nomenclature of topological objects in multiband superconductors is much richer than that in conventional single - band superconductors . in particular , ginzburg - landau equations describing two - band superconductivity in bulk samples admit topologically stable solutions ( with one - dimensional singularities of the order parameter ) that can be interpreted as vortices carrying fractional magnetic flux.@xcite in the absence of any interband coupling , these vortices are accompanied by a circulating neutral superfow associated with gradients of the interband phase difference . in the presence of `` josephson - type '' interband coupling , the neutral superflow generates static solitons of the sine - gordon type ..
Please generate the next two sentences of the article | in contrast to traditional abrikosov vortices in type - ii superconductors , the energy per unit length of these composite topological defects diverges at spatial infinity : hence they are thermodynamically metastable and difficult to create in bulk samples .
however , solitons of the interband phase difference can exist by themselves in doubly - connected mesoscopic samples , when the formation of any magnetic vortices in the volume of the superconductor is prohibited energetically.@xcite moreover , soliton states in this case can be induced by an externally applied magnetic field , which makes them a convenient object of investigation . |
7,755 | Suppose that you have an abstract for a scientific paper: a novel approach to complex problems has been previously applied to graph classification and the graph equivalence problem . here
we apply it to the np complete problem of finding the largest perfect clique within a graph @xmath0 . .
And you have already written the first three sentences of the full article: in a novel dynamical approach the @xmath1 vertices of a graph @xmath0 are mapped onto @xmath1 physical points located initially at equal distances from each other forming a symmetric @xmath1 simplex in @xmath2 dimensions .
attractive / repulsive forces are introduced between pairs of points corresponding to connected / disconnected vertices in the original graph @xmath0 .
we then let the system evolve utilizing first order aristotelian dynamics@xcite ..
Please generate the next two sentences of the article | we tune the relative strength of repulsive and attractive forces to be @xmath3 with @xmath4 the average valency i.e. average number of vertices connected to a given vertex so as to have no net average repulsion / attractions .
we found , that as the system evolves various physical clusters of points tend to form . |
7,756 | Suppose that you have an abstract for a scientific paper: inclined air showers those arriving at ground with zenith angle with respect to the vertical @xmath0 are characterised by the dominance of the muonic component at ground which is accompanied by an electromagnetic halo " produced mainly by muon decay and muon interactions . by means of monte carlo simulations
we give a full characterisation of the particle densities at ground in ultra - high energy inclined showers as a function of primary energy and mass composition , as well as for different hadronic models assumed in the simulations .
we also investigate the effect of intrinsic shower - to - shower fluctuations in the particle densities .
cosmic rays , extensive air showers , ground detector , simulation , muon component , electromagnetic component 96.50.s , 96.50.sd , 13.85.tp .
And you have already written the first three sentences of the full article: inclined air showers are conventionally defined as those arriving at ground with zenith angles @xmath1 above @xmath2 . at large
zenith angles the electromagnetic ( em ) component in air showers , mainly produced by the decay of @xmath3s , is largely absorbed in the greatly enhanced atmospheric depth the shower needs to cross before reaching ground , so that in a first approximation only the more penetrating particles such as muons survive to ground .
muons are accompanied by an electromagnetic component produced mainly by muon decay in flight and muon interactions such as bremsstrahlung , pair production and nuclear interactions ..
Please generate the next two sentences of the article | a full characterisation of this so - called electromagnetic halo " is given in this work .
the study of inclined showers is of great interest because their detection immediately enhances the exposure of existing air shower detectors by up to about @xmath4 with respect to that achieved with vertical showers @xmath5 , extending the field of view to sky directions otherwise inaccessible . |
7,757 | Suppose that you have an abstract for a scientific paper: we have precisely measured the nernst effect in nd - doped la@xmath0sr@xmath1cuo@xmath2 single crystals with controlling the strength ( stability ) of the stripe order .
we found that the onset temperature @xmath3 , where the nernst signal starts increasing , does not change conspicuously in spite of nd - doping . at low temperatures , on the other hand , the absolute value of the nernst signal is strongly suppressed in accordance with the strength of the stripe order .
these results imply that the fluctuation of ( charge ) stripe order enhances the nernst signal below @xmath3 at high temperatures , and then the stripe order enhanced by nd - doping suppresses the superconducting fluctuation to reduce the nernst signal at low temperatures .
we also observed an increase of the nernst signal below the charge order temperature @xmath4 which is observed in diffraction measurement .
nernst effect , vortex flow , stripe order 74.25.fy , 74.72.dn , 74.62.dh .
And you have already written the first three sentences of the full article: the nernst effect in the normal state of high-@xmath5 cuprates has become a focus of renewed attention since the detection of an anomalous nernst signal in the normal state of underdoped cuprates @xcite .
it is widely accepted that the large nernst signal is attributed to the movement of vortices which survives far above @xmath5 . on the other hand ,
a large negative nernst coefficient , which is comparable to the vortex signal in the superconducting state , has been reported in the charge density wave state of nbse@xmath6 @xcite ..
Please generate the next two sentences of the article | recently , it is reported that the stripe order causes the nernst signal to become large in nd or eu doped la@xmath0sr@xmath1cuo@xmath2 @xcite .
thus , two mechanisms for the origin of nernst effect have been discussed up to now . |
7,758 | Suppose that you have an abstract for a scientific paper: by modelling the coronal structures by `` slowly '' evolving double beltrami two fluid equilibria ( created by the interaction of the magnetic and velocity fields ) , the conditions for catastrophic transformations of the original state are derived .
it is shown that , at the transition , much of the magnetic energy of the original state is converted to the the flow kinetic energy . _
subject headings : _ sun : flares sun : corona - sun : magnetic fields ' '' '' + @xmath0 0.1 cm plasma physics department , tbilisi + 1.6 cm state university , tbilisi 380028 , georgia + @xmath1 e mail : [email protected] + @xmath2 e mail : [email protected] + 1.6 cm [email protected] + @xmath3 e mail : [email protected] + @xmath4 e mail : [email protected] + .
And you have already written the first three sentences of the full article: the latest trace and soho / eit observations have brought the solar corona into sharp focus .
the observations reveal : 1 ) the structures that constitute the solar corona are in constant motion ; they are full of fast moving gases , and are heated primarily at their footpoints ( base ) very close to the solar surface .
the heating occurs in few minutes in the first ten to twenty thousand kilometers above the surface , i.e , in a rather small fraction of the bright part of the anchored structure . in direct contradiction to the predictions of some theories ,.
Please generate the next two sentences of the article | the heating is neither uniform ( throughout the loops ) nor does it happen preferentially near the top .
a direct quote sums up the situation aptly : moreover , not only heat is deposited low down , but the gas is often actually thrust upward very rapidly . |
7,759 | Suppose that you have an abstract for a scientific paper: fluka is a general purpose monte carlo transport and interaction code used for fundamental physics and for a wide range of applications .
these include cosmic ray physics ( muons , neutrinos , eas , underground physics ) , both for basic research and applied studies in space and atmospheric flight dosimetry and radiation damage .
a review of the hadronic models available in fluka and relevant for the description of cosmic ray air showers is presented in this paper .
recent updates concerning these models are discussed .
the fluka capabilities in the simulation of the formation and propagation of em and hadronic showers in the earth s atmosphere are shown . .
And you have already written the first three sentences of the full article: extended air showers ( eas ) are originated by highly energetic cosmic rays , which interact with air atoms in the earth s atmosphere , producing elementary hadrons and nuclear fragments .
neutral pions immediately decay in two photons , which in turn interact with other particles , generating electromagnetic cascades , while charged pions and kaons , as well as other hadrons , interact and/or decay , depending on their energy and air density , leading to the hadronic component of the shower .
thus , to understand a process as complex as an air shower , models and codes capable of describing the evolution of both the electromagnetic and the hadronic component are needed ..
Please generate the next two sentences of the article | monte carlo codes have been developed in the last few years for this purpose , such as the corsika simulation package @xcite , allowing to choose among different models and model combinations for the description of eas formation and propagation . in this paper , the fluka monte carlo code @xcite
is applied to the study of eas induced by cosmic rays with primary energies up to 1000 tev . |
7,760 | Suppose that you have an abstract for a scientific paper: modified gravity models are subject to a number of consistency requirements which restrict the form that the function @xmath0 can take .
we study a particular class of @xmath0 functions which satisfy various constraints that have been found in the literature .
these models have a late time accelerating epoch , and an acceptable matter era .
we calculate the friedmann equation for our models , and show that in order to satisfy the constraints we impose , they must mimic general relativity plus @xmath1 throughout the cosmic history , with exponentially suppressed corrections .
we also find that the free parameters in our model must be fine tuned to obtain an acceptable late time accelerating phase .
we discuss the generality of this conclusion . .
And you have already written the first three sentences of the full article: in recent years , experimental cosmology has provided strong evidence that the universe is currently undergoing a phase of accelerated expansion .
the physical phenomena responsible for this expansion has proved elusive , and there are numerous theories that attempt to explain the current epoch of the universe . typically , the observed acceleration is attributed to a new energy component , dark energy , which dominates at late times .
numerous models exist of this form , the simplest of which include introducing a cosmological constant @xmath1 , or alternatively a scalar field slowly rolling down a potential . although dark energy is undoubtedly the most popular explanation of the current epoch of the universe , it is not the only way to obtain late time acceleration . in this paper.
Please generate the next two sentences of the article | we consider a class of models where gravity is modified at large scales , in such a way that the late - time expansion of the universe could arise naturally from the new gravitational field equations .
these modified gravity models have been considered by numerous authors , see for example @xcite . modifying gravity in a manner consistent with experimental data has proved difficult . |
7,761 | Suppose that you have an abstract for a scientific paper: the auditory system displays remarkable sensitivity and frequency discrimination , attributes shown to rely on an amplification process that involves a mechanical as well as a biochemical response . models that display proximity to an oscillatory onset ( a.k.a .
hopf bifurcation ) exhibit a resonant response to distinct frequencies of incoming sound , and can explain many features of the amplification phenomenology . to understand the dynamics of this resonance , frequency locking
is examined in a system near the hopf bifurcation and subject to two types of driving forces : additive and parametric .
derivation of a universal amplitude equation that contains both forcing terms enables a study of their relative impact on the hair cell response . in the parametric case , although the resonant solutions are 1:1 frequency locked , they show the coexistence of solutions obeying a phase shift of @xmath0 , a feature typical of the 2:1 resonance .
different characteristics are predicted for the transition from unlocked to locked solutions , leading to smooth or abrupt dynamics in response to different types of forcing .
the theoretical framework provides a more realistic model of the auditory system , which incorporates a direct modulation of the internal control parameter by an applied drive .
the results presented here can be generalized to many other media , including faraday waves , chemical reactions , and elastically driven cardiomyocytes , which are known to exhibit resonant behavior . .
And you have already written the first three sentences of the full article: the sense of hearing requires exquisite mechanical detection , with barely audible tones evoking displacements of the basilar membrane on the order of angstroms @xcite .
the auditory system is also highly tuned , with frequency selectivity in various species reaching 0.1% , and the frequency range reaching as high as 100 khz . over the last 60 years
, there have been significant advances in our understanding of the inner ear ..
Please generate the next two sentences of the article | however , the detailed mechanisms of the auditory system are still not understood , and thus , deficits are being mostly aided by technological solutions , such as cochlear implants .
nonlinear effects have been shown to be important for the extreme sensitivity and robustness of the inner ear @xcite . |
7,762 | Suppose that you have an abstract for a scientific paper: neutron scattering is a powerful probe of strongly correlated systems .
it can directly detect common phenomena such as magnetic order , and can be used to determine the coupling between magnetic moments through measurements of the spin - wave dispersions . in the absence of magnetic order , one can detect diffuse scattering and dynamic correlations .
neutrons are also sensitive to the arrangement of atoms in a solid ( crystal structure ) and lattice dynamics ( phonons ) . in this chapter
, we provide an introduction to neutrons and neutron sources . the neutron scattering cross section is described and formulas are given for nuclear diffraction , phonon scattering , magnetic diffraction , and magnon scattering .
as an experimental example , we describe measurements of antiferromagnetic order , spin dynamics , and their evolution in the la@xmath0ba@xmath1cuo@xmath2 family of high - temperature superconductors . .
And you have already written the first three sentences of the full article: a common symptom of correlated - electron systems is magnetism , and neutron scattering is the premiere technique for measuring magnetic correlations in solids . with a spin angular momentum of @xmath3 ,
the neutron interacts directly with the magnetization density of the solid .
elastic scattering can directly reveal static magnetic order ; for example , neutron diffraction provided the first experimental evidence for nel antiferromagnetism @xcite . through inelastic scattering one can probe dynamic spin - spin correlations ; in an ordered antiferromagnet , one can measure the precession of the spins about their average orientations , which show up as dispersing spin waves ..
Please generate the next two sentences of the article | neutrons do not couple to the charge of the electrons , but instead scatter from atomic nuclei via the strong force . despite the name , the small size of the nucleus compared to the electronic charge cloud of the atom results in a rather weak scattering cross section .
the magnetic and nuclear scattering cross sections are comparable , so that neutron scattering is very sensitive to magnetism , in a relative sense . |
7,763 | Suppose that you have an abstract for a scientific paper: in this paper numerical methods of computing distances between two radon measures on @xmath0 are discussed .
efficient algorithms for wasserstein - type metrics are provided . in particular , we propose a novel algorithm to compute the flat metric ( bounded lipschitz distance ) with a computational cost @xmath1 . the flat distance has recently proven to be adequate for the escalator boxcar train ( ebt ) method for solving transport equations with growth terms . therefore ,
finding efficient numerical algorithms to compute the flat distance between two measures is important for finding the residual error and validating empirical convergence of different methods .
* keywords : * metric spaces , flat metric , wasserstein distance , radon measures , optimal transport , linear programming , minimum - cost flow .
And you have already written the first three sentences of the full article: recent years witnessed large developments in the kinetic theory methods applied to mathematical physics and more recently also to mathematical biology . among important branches of the kinetic theory
are optimal transportation problems and related to them wasserstein metrics , and monge - kantorovich metrics @xcite .
partial differential equations in metric spaces are being applied to transportation problems @xcite , gradient flows @xcite and structured population models @xcite ..
Please generate the next two sentences of the article | output of mathematical modeling can often be described as radon measures .
comparing the results of the models requires then a definition of distance in the space of measures . |
7,764 | Suppose that you have an abstract for a scientific paper: we study both oscillating and inflating curvaton scenarios when the curvaton mechanism is caused by a hybrid potential .
the source of the curvature perturbation is the inhomogeneous phase transition that causes the modulation of the onset of the oscillation . for the supergravity - motivated curvaton
there is a possibility of finding natural coincidence of the energy density that is needed to affect non - gaussianity in the curvaton scenario . .
And you have already written the first three sentences of the full article: the primordial perturbation in the inflationary epoch is widely believed to be the primary origin of the formation of the large - scale structure in the universe @xcite .
the generation of the curvature perturbation @xmath0 in the original inflation scenario is due to the inflaton perturbation @xmath1 that exits the horizon during inflation .
the curvature perturbation @xmath0 in the original single - field inflation scenario is generated from the inflaton perturbation @xmath2 , which remains constant after the horizon exit . in the curvaton scenario , @xmath0 is instead generated after inflation from the isocurvature perturbation of a curvaton field @xcite ( for a recent review see ref ..
Please generate the next two sentences of the article | @xcite ) .
in this paper we consider a hybrid potential for the curvaton scenario and study both the original ( oscillating ) @xcite and the inflating curvaton @xcite . |
7,765 | Suppose that you have an abstract for a scientific paper: in this paper we examine the decay of quantum correlations for the radiation field in a two - mode squeezed thermal state in contact with local thermal reservoirs .
two measures of the evolving quantum correlations are compared : the entanglement of formation and the quantum discord .
we derive analytic expressions of the entanglement - death time in two special cases : when the reservoirs for each mode are identical , as well as when a single reservoir acts on the first mode only . in the latter configuration , we show that all the pure gaussian states lose their entanglement at the same time determined solely by the field - reservoir coupling .
also investigated is the evolution of the gaussian quantum discord for the same choices of thermal baths .
we notice that the discord can increase in time above its initial value in a special situation , namely , when it is defined by local measurements on the attenuated mode and the input state is mixed .
this enhancement of discord is stronger for zero - temperature reservoirs and increases with the input degree of mixing . .
And you have already written the first three sentences of the full article: the extent to which the non - classical properties of one - mode field states survive in the presence of noise and losses was investigated since the early years of quantum optics @xcite . a routine operation like the transmission of light beams through an optical fiber could produce a substantial degradation of their non - classical properties . as an example , it was found that squeezing properties are altered by admixture with thermal noise and disappear completely for values of thermal mean photon occupancy exceeding the threshold @xmath0 @xcite . from a more recent quantum - information perspective
, a lot of work is concentrated on correlations such as entanglement and discord in multi - partite systems @xcite .
while correlations associated with entanglement @xcite are defined in connection to global transformations of bipartite quantum states , the concept of quantum discord arises from local ( marginal ) actions and measurements performed on one subsystem @xcite ..
Please generate the next two sentences of the article | its definition contains an optimization over the set of all one - party measurements , which in the case of mixed states could be a challenging problem .
note that in the pure - state case , entanglement and discord coincide and therefore they measure the total amount of correlations . in the mixed - state case , quantum discord is a measure of quantumness whose relation to entanglement is not a simple one . |
7,766 | Suppose that you have an abstract for a scientific paper: neutrinoless double beta decay pops up almost in any extension of the standard model .
it is perhaps the only process , which can unambiguously determine whether the massive neutrinos are majorana or dirac type particles .
in addition from the lifetime of this decay , combined with sufficient knowledge of the relevant nuclear matrix elements , one can set a constraint involving the neutrino masses .
furthemore , if one incorporates the recent results of the neutrino oscillation experiments , one can determine or set a stringent limit on the neutrino mass scale .
in addition one may obtain usefull information regarding the presence of right handed currents and the right handed neutrino mass scale .
one can also constrain the parameters of supersymmetry and , in particular , set limits in of r - parity violating couplings as well as get information about extra dimensions . .
And you have already written the first three sentences of the full article: neutrinoless double beta decay occurs whenever ordinary beta decay is forbidden due to energy conservation or retarded due to angular momentum mismatch , but the nucleus , which is two units of charge away , is accessible via a order week interaction@xcite-@xcite .
it is a process known for almost 70 years , which has been searched for , but not seen yet .
it is still of great theoretical and experimental interest since perhaps it is the only process , which can unambiguously determine whether massive neutrinos can be majorana or dirac type particles . it can occur only if the mass eigenstates are majorana particles ( the particle coincides with its antiparticle ) . in the weak basis @xmath0 ,.
Please generate the next two sentences of the article | @xmath1 the neutrino mass matrix takes the form : @xmath2 + where @xmath3 is a @xmath4 left - handed ( isotriplet ) majorana mass matrix , @xmath5 is a dirac @xmath6 mass matrix and @xmath7 is the right - handed ( isosinglet ) @xmath8 majorana mass matrix . in models motivated by gut
s @xmath9 , @xmath10 , @xmath5 is of the order of the up quark mass matrix and @xmath7 is very heavy ( @xmath11 gev ) so that light neutrinos with mass of order @xmath12 can occur . on the other hand in r - parity violating supersymmetry |
7,767 | Suppose that you have an abstract for a scientific paper: we study the quantum mechanics of self - gravitating thin shell collapse by solving the polymerized wheeler - dewitt equation .
we obtain the energy spectrum and solve the time dependent equation using numerics . in contradistinction to the continuum theory , we are able to consistently quantize the theory for super - planckian black holes , and find two choices of boundary conditions which conserve energy and probability , as opposed to one in the continuum theory .
another feature unique to the polymer theory is the existence of negative energy stationary states that disappear from the spectrum as the polymer scale goes to zero . in both theories
the probability density is positive semidefinite only for the space of positive energy stationary states .
dynamically , we find that an initial gaussian probability density develops regions of negative probability as the wavepacket approaches @xmath0 and bounces .
this implies that the bouncing state is a sum of both positive and negative eigenstates . .
And you have already written the first three sentences of the full article: the quantum mechanical regime of gravitation continues to be opaque to our probing , both theoretically and experimentally , in the latter case due to the extreme weakness of the gravitational interaction .
there are now many theoretical probes , including ( but not limited to ) string theory , loop quantum gravity , spin foams , causal sets , causal dynamical triangulations and asymptotic safety .
however , none of these are yet complete or able to predict phenomena which can be seen experimentally . given the lack of experimental direction , we must rely heavily on philosophy and mathematics to justify any particular approach . these circumstances have motivated the careful study of mathematical toy models , often obtained by imposing symmetry and/or changing the number of dimensions of spacetime ..
Please generate the next two sentences of the article | such models , if exactly solvable , could help us to see around the obstacles occluding our view of the quantum regime of realistic theories of gravity .
it is also possible that results obtained in the toy models might survive the transition to realistic models , and provide the basis for attempts to experimentally test quantum gravity |
7,768 | Suppose that you have an abstract for a scientific paper: we present a class of higher dimensional solutions to einstein - maxwell equations in @xmath0dimensions .
these solutions are asymptotically locally flat , de sitter , or anti de sitter space - times .
the solutions we obtained depend on two extra parameters other than the mass and the nut charge .
these two parameters are the electric charge @xmath1 and the electric potential at infinity , @xmath2 , which has a non - trivial contribution .
we analyze the conditions one can impose to obtain taub - nut or taub - bolt space - times , including the four - dimensional case .
we found that in the nut case these conditions coincide with that coming from the regularity of the one - form potential at the horizon .
furthermore , the mass parameter for the higher dimensional solutions depends on the nut charge and the electric charge or the potential at infinity . .
And you have already written the first three sentences of the full article: the importance of taub - nut solutions covers a wide area of application that extends from general relativity to string theory .
these solutions @xcite are characterized by non - vanishing nut charges . as a result , they are locally asymptotically flat , i.e. , their boundaries are not @xmath3 but @xmath4 fiber over @xmath5 .
these boundaries are topologically interesting since they do have a non - vanishing first chern number @xmath6 which is proportional to the nut charge . in these space - times.
Please generate the next two sentences of the article | one can not define a global time function , therefore , these manifolds can not be foliated using constant time surfaces and it is not possible to describe their time evolution through a unitary hamiltonian evolution .
taub - nut spaces are also characterized by the existence of zero - dimensional fixed point set of the @xmath7 isometry generated by the time - like killing vector @xmath8 , which is called a nut . |
7,769 | Suppose that you have an abstract for a scientific paper: it is widely believed that the scaling limit of self - avoiding walks ( saws ) at the critical temperature is ( i ) conformally invariant , and ( ii ) describable by schramm - loewner evolution ( sle ) with parameter @xmath0 we consider saws in a rectangle , which originate at its centre and end when they reach the boundary .
we assume that the scaling limit of saws is describable by @xmath1 with the value of @xmath2 to be determined .
it has previously been shown by guttmann and kennedy @xcite that , in the scaling limit , the ratio of the probability that a saw hits the side of the rectangle to the probability that it hits the end of the rectangle , depends on @xmath3 by considering rectangles of fixed aspect ratio 2 , and also rectangles of aspect ratio 10 , we calculate the probabilities exactly for larger and larger rectangles . by extrapolating this data to infinite rectangle size , we obtain the estimate @xmath4 for rectangles of aspect ratio 2 and @xmath5 for rectangles of aspect ratio 10 .
we also provide numerical evidence supporting the conjectured distribution of saws striking the boundary at various points in the case of rectangles with aspect ratio 2 .
.3 cm .
And you have already written the first three sentences of the full article: a self - avoiding walk ( saw ) of length @xmath6 on a periodic graph or lattice @xmath7 is a sequence of distinct vertices @xmath8 in @xmath7 such that each vertex is a nearest neighbour of its predecessor . in figure
[ fig : saw ] a very long walk of @xmath9 steps is shown ( generated by a monte carlo algorithm @xcite ) .
steps on the square lattice courtesy of nathan clisby.,width=188 ] consider now those saws starting at the centre of an @xmath10 rectangle and ending when they hit the boundary ..
Please generate the next two sentences of the article | we take the scaling limit of saw , at the critical point , in the usual way ( described , for example , in @xcite ) .
let @xmath11 be the probability that a randomly chosen saw , in the scaling limit , hits the side of the rectangle before the end , and let @xmath12 be the probability that it hits the end before the side . in guttmann and kennedy @xcite the probability ratio @xmath13 was calculated , under the assumption that the scaling limit is describable by @xmath14 for a rectangle of aspect ratio @xmath15 with parameter @xmath16 where @xmath17 they found , asymptotically , @xmath18,\ ] ] for @xmath19 where @xmath20 the exact result is given as the ratio of two integrals ( [ rat ] ) , and we give an outline of their calculation in the following section . in this work , we have considered all @xmath21 rectangles of aspect ratio 2 of size @xmath22 up to @xmath23 and have generated all saw starting at the origin and ending on the boundary of the rectangles . |
7,770 | Suppose that you have an abstract for a scientific paper: we study the important problem of tracking moving targets in wireless sensor networks .
we try to overcome the limitations of standard state of the art tracking methods based on continuous location tracking , i.e. the high energy dissipation and communication overhead imposed by the active participation of sensors in the tracking process and the low scalability , especially in sparse networks .
instead , our approach uses sensors in a passive way : they just record and judiciously spread information about observed target presence in their vicinity ; this information is then used by the ( powerful ) tracking agent to locate the target by just following the traces left at sensors .
our protocol is greedy , local , distributed , energy efficient and very successful , in the sense that ( as shown by extensive simulations ) the tracking agent manages to quickly locate and follow the target ; also , we achieve good trade - offs between the energy dissipation and latency . oddfootto evenfootto .
And you have already written the first three sentences of the full article: recent advances in micro - electromechanical systems ( mems ) and wireless communications have enabled the development of very small , smart , low cost sensing devices ( @xcite ) with sensing , data - processing and wireless transmission capabilities .
they are meant to be pervasively deployed into forming ad - hoc wireless sensor networks that collect information from the ambient environment and make it available to the user .
some applications imply deployment in remote or hostile environments ( battle - field , tsunami , earth - quake , isolated wild - life island , space exploration ) to assist in tasks such as target tracking , enemy intrusion detection , forest fire detection , environmental or biological monitoring ..
Please generate the next two sentences of the article | some other applications imply deployment indoors or in urban or controlled environments .
examples of such applications are industrial supervising , indoor micro - climate monitoring ( e.g. to reduce heating cost by detecting poor building thermal insulation ) , smart - home applications , patient - doctor health monitoring or blind and impaired assisting . |
7,771 | Suppose that you have an abstract for a scientific paper: we report on the observation of the bright , long gamma - ray burst , grb 090902b , by the gamma - ray burst monitor ( gbm ) and large area telescope ( lat ) instruments on - board the _ fermi _ observatory .
this was one of the brightest grbs to have been observed by the lat , which detected several hundred photons during the prompt phase . with a redshift of @xmath0 ,
this burst is among the most luminous detected by _
fermi_. time - resolved spectral analysis reveals a significant power - law component in the lat data that is distinct from the usual band model emission that is seen in the sub - mev energy range .
this power - law component appears to extrapolate from the gev range to the lowest energies and is more intense than the band component both below @xmath150kev and above 100mev .
the band component undergoes substantial spectral evolution over the entire course of the burst , while the photon index of the power - law component remains constant for most of the prompt phase , then hardens significantly towards the end .
after the prompt phase , power - law emission persists in the lat data as late as 1 ks post - trigger , with its flux declining as @xmath2 .
the lat detected a photon with the highest energy so far measured from a grb , @xmath3 gev .
this event arrived 82 seconds after the gbm trigger and @xmath150seconds after the prompt phase emission had ended in the gbm band .
we discuss the implications of these results for models of grb emission and for constraints on models of the extragalactic background light . .
And you have already written the first three sentences of the full article: the _ fermi _ gamma - ray space telescope hosts two instruments , the large area telescope @xcite and the gamma - ray burst monitor @xcite , which together are capable of measuring the spectral parameters of gamma - ray bursts ( grbs ) across seven decades in energy . since the start of gbm and lat science operations in early august 2008 , emission at energies
@xmath4100mev has been detected from ten grbs .
these detections were made possible by the lat s greater sensitivity and shorter deadtime ( 26@xmath5s ) compared to previous instruments . prior to _ fermi _ , high - energy gamma - rays from grbs with energies up to 18 gev were observed by the egret instrument on - board the _ compton gamma - ray observatory_. the egret observations suggested three types of high - energy emission : an extrapolation of the low energy spectra to the @xmath4100 mev band ( e.g. , * ? ? ?.
Please generate the next two sentences of the article | * ) , an additional spectral component during the prompt emission @xcite and in the case of grb 940217 , a gev afterglow which was detectable for 90 minutes after the trigger @xcite .
the redshifts of these events were not determined . |
7,772 | Suppose that you have an abstract for a scientific paper: using first - principles calculations , we analyze the structural properties of tungsten trioxide wo@xmath0 .
our calculations rely on density functional theory and the use of the b1-wc hybrid functional , which provides very good agreement with experimental data .
the hypothetical high - symmetry cubic reference structure combines several ferroelectric and antiferrodistortive ( antipolar cation motions , rotations and tilts of oxygen octahedra ) structural instabilities .
the instability related to antipolar w motions combines with those associated to oxygen rotations and tilts to produce the biggest energy reduction , yielding a @xmath1 ground state .
this non - polar @xmath1 phase is only different from the experimentally reported @xmath2 ground state by the absence of a very tiny additional ferroelectric distortion .
the calculations performed on a stoichiometric compound so suggest that the low temperature phase of wo@xmath0 is not intrinsically ferroelectric and that the reported ferroelectric character might arise from extrinsic defects such as oxygen vacancies . independently , we also identify never observed @xmath3 and @xmath4 ferroelectric phases with large polarizations and low energies close to the @xmath1 ground state , which makes wo@xmath0 a potential antiferroelectric material
. the relative stability of various phases is discussed in terms of the couplings between different structural distortions , highlighting a very complex interplay involving improper - like couplings up to fourth order in the energy expansion in the cubic phase . .
And you have already written the first three sentences of the full article: tungsten trioxide , wo@xmath0 , has been extensively studied due to its very attractive and rich properties for technological applications . wo@xmath0 and its derivatives h@xmath5wo@xmath0 and wo@xmath6 are electrochromic,@xcite thermocromic,@xcite and superconducting.@xcite
it has been envisaged that wo@xmath0 may become one of the best materials for electrochromic applications such as in energy - efficient windows , smart glasses , antiglare automobile rear - view mirrors , sunroofs , displays , or even tunable photonic crystals@xcite and to reduce photocorrosion.@xcite the wide variety of the underlying electronic instabilities for these properties is mirrored by a multitude of related structural instabilities , which were investigated ever since 1975@xcite and refined later.@xcite all known wo@xmath0 phases are characterized by very large distortions of the archetypal perovskite structure so that even the notion of octahedra tilts is to be taken with some caution .
the wo@xmath7 octahedra are so largely distorted that the variance of w o distances in any observed structure is far greater than in most other known perovskite structures.@xcite in this paper we make the fundamental connection between the electronic and structural structure properties of wo@xmath0 and show that most , if not all , structural instabilities can be derived from a careful analysis of its intrinsic cubic phonon instabilities , despite these large deformation amplitudes . the structural properties can be summarized as follows : wo@xmath0 shows no proper melt , surface melting of crystalline material occurs at 1746 k. crystal growth proceeds typically by sublimation and gas transport at temperatures below 1400k . at the highest temperatures the structures.
Please generate the next two sentences of the article | is tetragonal ( space group @xmath8 ) with strong antiferrodistortive ( afd ) cation movements so that the wo@xmath7 octahedra are strongly distorted@xcite in an anti - polar pattern .
additional rotational octahedral distortions condense in addition to the initial tetragonal displacements when lowering the temperature . |
7,773 | Suppose that you have an abstract for a scientific paper: we report on the results of 34 @xmath0 m spectroscopy of the ultra - luminous infrared galaxy ( ulirg ) ugc 5101 .
it has a cool far - infrared color and a liner - type optical spectrum , and so , based on a view gaining some currency , would be regarded as dominated by star formation .
however , we find that it has strong 3.4 @xmath0 m carbonaceous dust absorption , low - equivalent - width 3.3 @xmath0 m polycyclic aromatic hydrocarbon ( pah ) emission , and a small 3.3 @xmath0 m pah to far - infrared luminosity ratio .
this favors an alternative scenario , in which an energetically dominant agn is present behind obscuring dust .
the agn is plausibly obscured along all lines of sight ( a ` buried agn ' ) , rather than merely obscured along our particular line of sight .
such buried agns have previously been found in thermal infrared studies of the ulirgs iras 08572 + 3915 and iras f00183@xmath17111 , both classified optically as liners .
we argue that buried agns can produce liner - type optical spectra , and that at least some fraction of liner - type ulirgs are predominantly powered by buried agns . .
And you have already written the first three sentences of the full article: ultra - luminous infrared galaxies ( ulirgs ) radiate most of their extremely large , quasar - like luminosities ( @xmath2 ) as infrared dust emission , and dominate the bright end of the galaxy luminosity function in the nearby universe @xcite .
recent studies have revealed that the bulk of the cosmic sub - mm background emission has been resolved into discrete sources , similar to nearby ulirgs @xcite , and for this reason data on nearby ulirgs have been extensively used to derive information on star - formation rates , dust content , and metallicity in the early universe @xcite . understanding the nature of nearby ulirgs is therefore of particular importance both locally and cosmologically .
in contrast to the majority of less infrared luminous ( @xmath3 10@xmath4 ) galaxies , it has been suggested that energetically important , dust - obscured agns are present in ulirgs ( veilleux , kim , & sanders 1999a ; fischer 2000 ) ..
Please generate the next two sentences of the article | if the geometry of the dust distribution is toroidal and/or the amount of dust along our line of sight is not too great , signatures of such dust - obscured agns can be found in the optical and/or near - infrared wavelength range at @xmath5 2 @xmath0 m @xcite .
however , detecting agns that are deeply embedded in a spherical dust shell ( hereafter buried agns ) and estimating their energetic importance is very difficult at @xmath5 2 @xmath0 m , even though they are energetically important , since spectral tracers are dominated by less strongly obscured star - formation activity . |
7,774 | Suppose that you have an abstract for a scientific paper: direct collapse black holes ( dcbhs ) formed from the collapse of atomically - cooled primordial gas in the early universe are strong candidates for the seeds of supermassive bhs .
dcbhs are thought to form in atomic cooling haloes in the presence of a strong molecule - dissociating , lyman - werner ( lw ) radiation field . given that star forming galaxies are likely to be the source of the lw radiation in this scenario , ionizing radiation from these galaxies may accompany the lw radiation .
we present cosmological simulations resolving the collapse of primordial gas into an atomic cooling halo , including the effects of both lw and ionizing radiation .
we find that in cases where the gas is not self - shielded from the ionizing radiation , the collapse can be delayed by @xmath0 25 myr . when the ionized gas does collapse , the free electrons that are present catalyze h@xmath1 formation .
in turn , h@xmath1 cooling becomes efficient in the center of the halo , and dcbh formation is prevented .
we emphasize , however , that in many cases the gas collapsing into atomic cooling haloes at high redshift is self - shielding to ionizing radiation .
therefore , it is only in a fraction of such haloes in which dcbh formation is prevented due to reionization .
-0.8 cm black holes molecules early universe cosmology : theory .
And you have already written the first three sentences of the full article: the origin of the black holes ( bhs ) inhabiting the centers of massive galaxies ( e.g. gebhardt et al .
2000 ; merritt & ferrarese 2001 ) and powering luminous quasars at high redshift ( e.g. willott et al .
2003 ; fan et al ..
Please generate the next two sentences of the article | 2006 ; mortlock et al .
2011 ) has long been an open question at the forefront of cosmology and galaxy formation . |
7,775 | Suppose that you have an abstract for a scientific paper: short gamma - ray bursts ( grbs ) are believed to be produced by relativistic jets from mergers of neutron - stars ( ns ) or neutron - stars and black - holes ( bh ) .
if the lorentz - factors@xmath0of jets from compact - stellar - mergers follow a similar power - law distribution to those observed for other high - energy astrophysical phenomena ( e.g. blazars , agn ) , the population of jets would be dominated by low-@xmath1 outflows .
these jets will not produce the prompt gamma - rays , but jet energy will be released as x - ray / optical / radio transients when they collide with the ambient medium . using monte carlo simulations , we study the properties of such transients .
approximately@xmath2of merger - jets@xmath3mpc result in failed - grbs if the jet@xmath0follows a power - law distribution of index @xmath4 .
x - ray / optical transients from failed - grbs will have broad distributions of their characteristics : light - curves peak @xmath5days after a merger ; flux peaks for x - ray @xmath6mjy ; and optical flux peaks at @xmath7 .
x - ray transients are detectable by swift xrt , and @xmath8 of optical transients will be detectable by telescopes with limiting magnitude @xmath9 , for well localized sources on the sky .
x - ray / optical transients are followed by radio transients with peak times narrowly clustered around @xmath10days , and peak flux of @xmath11mjy at 10@xmath12ghz and @xmath13mjy at 150@xmath12mhz . by considering the all - sky rate of short grbs within the ligo / virgo range ,
the rate of on - axis orphan afterglows from failed - grb would be 2.6(26 ) per year for ns - ns(ns - bh ) mergers , respectively .
since merger jets from gravitational - wave ( gw ) trigger events tend to be directed to us , a significant fraction of gw events could be associated with the on - axis orphan afterglow . .
And you have already written the first three sentences of the full article: gamma - ray bursts ( grbs ) are instantaneously the most luminous objects in the universe , produced by the deceleration of ultra - relativistic outflow ( lorentz factors @xmath14 ) .
the core - collapse of massive stars are the progenitor of long grbs , and the merger of binary compact stellar objects such as neutron stars ( ns ) and black holes ( bh ) are the possible progenitor of short grbs ( woosley & bloom 2006 , nakar 2007 , berger 2014 ) . in both cases accretion onto a compact object is likely to power the relativistic outflow and the same physical processes are involved .
the outflow energy is first dissipated by internal shocks ( or another form of internal dissipation ) which produces the prompt @xmath15-rays ..
Please generate the next two sentences of the article | later the interaction of the outflow with the ambient medium produces an external shock which expands and produces the subsequent afterglow ( e.g. piran 2004 ; zhang & mszros 2004 ) .
relativistic motion is an essential ingredient in the grb model although the exact outflow formation process is not known . |
7,776 | Suppose that you have an abstract for a scientific paper: rapid infall of gas in the nuclei of galaxies could lead to the formation of black holes by direct collapse , without first forming stars .
black holes formed in this way would have initial masses of a few @xmath0 , but would be embedded in massive envelopes that would allow them to grow at a highly super - eddington rate .
thus , seed black holes as large as @xmath1 could form very rapidly .
i will sketch the basic physics of the direct collapse process and the properties of the accreting envelopes .
address = jila , 440 ucb , university of colorado at boulder , boulder , co 80309 - 0440 usa .
And you have already written the first three sentences of the full article: despite years of study , we still do not know how the seeds of supermassive black holes formed .
few if any of the pathways in martin rees s famous flow chart ( begelman & rees 1978 ) can be ruled out , but none of the routes is particularly well understood , either .
what we do know is that some very massive ( @xmath2 ) black holes had to exist by @xmath3 in order to explain early quasars ( fan 2006 ) ..
Please generate the next two sentences of the article | if the seeds of these black holes were the remnants of massive stars , then they must have grown by eddington - limited accretion for most of the time since their formation , or else much of their growth was due to mergers .
a second possibility is that the seeds formed by such a rapid accumulation of matter that it may be considered to be a direct collapse . |
7,777 | Suppose that you have an abstract for a scientific paper: this paper generalizes two previously known techniques for generating minimally coupled einstein - scalar field solutions in 4 dimensions ; the buchdahl and fonarev transformations .
two generalizations are made : i ) the transformation is generalized to arbitrary dimension , and ii ) the new transformation allows vacuum solutions with non - zero cosmological constant as seed .
thus , by applying this solution generation technique , minimally coupled einstein - scalar field solutions can be generated from vacuum solutions with arbitrary cosmological constant in arbitrary dimension .
the only requirement to a seed solution is that it posesses a hypersurface - orthogonal killing vector field .
the generalization that allows us to use seed solutions with arbitrary cosmological constant uncovers a new class of einstein - scalar field solutions that has previously not been studied .
we apply the new solution transformation to the @xmath0 vacuum solution . transforming the resulting einstein - scalar field solution to the conformal frame , a two - parameter family of spatially finite , expanding and accelerating cosmological solutions
are found that are conformally isometric to the einstein static universe @xmath1 .
we study null geodesics and find that for any observer , the solution has a cosmological horizon at an angular distance of @xmath2 away from the observer .
a subset of these solutions are studied in particular : a solution of this kind has an initial point singularity that vanishes at early times as well as another point singularity that emerges at late times .
the solution is non - singular in between those events .
the late time singularity is hidden behind an event horizon , and these solutions can therefore be naturally interpreted as expanding cosmologies in which a scalar black hole is formed at late times .
the energy density is positive definite only in parts of the parameter space .
the conformally coupled scalar field satisfies the weak energy condition as long as....
And you have already written the first three sentences of the full article: the physical relevance of scalar fields in today s gravitational physics and cosmology primarily stems from i ) their key role in current models of early cosmological inflation , with predictions that to an astonishing degree have been confirmed by recent cosmological measurements @xcite , and ii ) the viability of scalar field models as candidate models for dark energy @xcite@xcite@xcite .
the fact that scalar fields are inevitable artifacts of string theory @xcite provides additional rationale for studying scalar fields . the continuing focus on extra - dimensional models in fundamental
physics provides motivation for studying scalar fields in dimensions higher than 4 ..
Please generate the next two sentences of the article | there is an extensive literature on known einstein - scalar field solutions . in a recent paper , wehus and ravndal @xcite
provide a good historical overview of the various einstein - scalar field solutions relevant for the present paper . |
7,778 | Suppose that you have an abstract for a scientific paper: the spin - wave relaxation mechanisms after intense laser excitation in ferromagnetic nickel films are investigated with all - optical pump - probe experiments .
uniform precession ( kittel mode ) , damon - eshbach surface modes and perpendicular standing spin waves can be identified by their dispersion @xmath0 .
however , different to other ferromagnets @xmath0 deviates from the expected behavior .
namely , a mode discontinuity is observed , that can be attributed to a non - linear process . above a critical field
the power spectrum reveals a redistribution of the energy within the spin - wave spectrum populated . .
And you have already written the first three sentences of the full article: spin - wave generation and manipulation have already been demonstrated in many ways.@xcite they are of great importance in magnetism - based spin - wave logic and xnor as well as nand gates have recently been implemented.@xcite to reduce the size of potential devices , effective spin - wave pumping mechanisms are needed in ferromagnetic metallic films owning micron to nanometer characteristic magnetic length scales . here
we present a pumping mechanism using fs - laser excitation that allows for a large precession angle ( @xmath1 ) after local excitation . on the other hand ,
the relevant length scales can be artificially selected by the design of magnonic crystals , i.e. periodically micro- and nano - structured magnetic materials , with only very selected dynamic eigen states . for large precession angles the equations of motion are intrinsically non - linear ..
Please generate the next two sentences of the article | this can be used to pump energy into a certain spin - wave mode by non - linear interaction and becomes evident for example in spin - wave nano - oscillators.@xcite given a spatial separation of two spin - torque oscillators and hence , an overlap in their spin - wave power when excited by a direct current , one finds a locking of frequencies if the frequency mismatch is below a critical value . driven to an extreme , a steady transfer of energy from higher to lower energy modes results in bose - einstein condensation observed at room temperature.@xcite under an external field of @xmath2 .
a large angle of precession as high as @xmath3 is observed . |
7,779 | Suppose that you have an abstract for a scientific paper: accurate measurement of relative distance and orientation of two nearby quantum particles is discussed .
we are in particular interested in a realistic description requiring as little prior knowledge about the system as possible .
thus , unlike in previous studies , we consider the case of an arbitrary relative orientation of the two atoms .
for this , we model the atom with complete zeeman manifolds , and include parallel as well as orthogonal dipole - dipole couplings between all states of the two atoms .
we find that it is possible to determine the distance of the two atoms independent of the orientation , as long as the particles are sufficiently close to each other .
next , we discuss how in addition the alignment of the atoms can be measured . for this
, we focus on the two cases of atoms in a two - dimensional waveguide and of atoms on a surface . .
And you have already written the first three sentences of the full article: progress in many areas of science and its application is fueled by the ongoing progress to measure and structure small objects . in many cases ,
light is used as a primary tool for reading or writing .
but since light is subject to diffraction , a straightforward implementation is restricted to structures of order of the involved wavelength @xcite ..
Please generate the next two sentences of the article | different methods have been invented to surpass this limit , such as near - field imaging @xcite , techniques based on the selective addressing of nearby particles @xcite , resolution enhancement due to non - classical effects @xcite , multiphoton spectroscopy @xcite , quantum lithography with classical fields @xcite , or position - dependent dark states @xcite . among the most fundamental problems in this area
is the measurement of the distance between two nearby quantum particles such as atoms . |
7,780 | Suppose that you have an abstract for a scientific paper: scattering for the energy critical non - linear wave equation for domains exterior to non trapping obstacles in 3 + 1 dimension is known for the star - shaped case . in this paper
, we extend the scattering for a class of non star - shaped obstacles called illuminated from exterior .
the main tool we use is the method of multipliers with weights that generalize the morawetz multiplier to suit the geometry of the obstacle . .
And you have already written the first three sentences of the full article: in this paper we are working on the energy critical nonlinear wave equation in 3 + 1 dimension in a domain @xmath0 where @xmath1 is a non - trapping obstacle with smooth boundary @xmath2 which enjoys the conservation of energy @xmath3 in the boundaryless case ( @xmath4 ) , the first results for the global existence were obtained by grillakis ( @xcite , @xcite ) .
he showed that there are global smooth solutions of the critical wave equation , if the data is smooth .
shatah and struwe ( @xcite , @xcite ) extended this theorem by showing that there are global solutions for the data lying in the energy space @xmath5 ..
Please generate the next two sentences of the article | they also obtained results for critical wave equation in higher dimensions .
for the case of obstacles , the first results were due to smith and sogge @xcite . |
7,781 | Suppose that you have an abstract for a scientific paper: we propose an adaptive finite element method to approximate the solutions to reaction - diffusion systems on time - dependent domains and surfaces .
we derive a computable error estimator that provides an upper bound for the error in the semidiscrete ( space ) scheme .
we reconcile our theoretical results with benchmark computations . .
And you have already written the first three sentences of the full article: our model problem consists of a system of chemicals that are coupled only through the reaction terms and diffuse independently of each other . given an integer @xmath0 ,
let @xmath1 be an ( @xmath2 ) vector of concentrations of chemical species , with @xmath3 , the spatial variable and @xmath4 , \
t>0,$ ] the time variable ..
Please generate the next two sentences of the article | the model we shall consider is of the following form ( see @xcite for details of the derivation ) : find @xmath5 , functions from @xmath6 into @xmath7 , such that for @xmath8 , @xmath5 satisfies @xmath9({\ensuremath{\boldsymbol{x}}},t)=f_{i}\left({\ensuremath{\boldsymbol{u}}}({\ensuremath{\boldsymbol{x}}},t)\right ) , & { \ensuremath{\boldsymbol{x}}}\in{\ensuremath{{\omega_t}}},t\in(0,t],\\ [ { \ensuremath{{{\ensuremath{\boldsymbol{\nu}}}}}}\cdot\nabla{u}_i]({\ensuremath{\boldsymbol{x}}},t)=0 , & \text { } { \ensuremath{\boldsymbol{x}}}\in\partial{\ensuremath{{\omega_t } } } , t>0,\\ u_i({\ensuremath{\boldsymbol{x}}},0)=u_i^{0}({\ensuremath{\boldsymbol{x } } } ) , & \text { } { \ensuremath{\boldsymbol{x}}}\in{\ensuremath{{\omega}}}_0 , \end{cases } \end{split}\ ] ] where @xmath10 is a simply connected bounded continuously deforming domain with respect to @xmath11 , with lipschitz boundary @xmath12 at time @xmath4 $ ] . the vector of nonlinear coupling terms @xmath13 is assumed to be locally lipschitz - continuous , @xmath14 is a vector of strictly positive diffusion coefficients , @xmath15 is a flow velocity generated by the evolution of the domain and the initial data @xmath16 is a bounded vector valued function .
systems of this form arise in the theory of biological pattern formation @xcite . |
7,782 | Suppose that you have an abstract for a scientific paper: declarative data quality has been an active research topic .
the fundamental principle behind a declarative approach to data quality is the use of declarative statements to realize data quality primitives on top of any relational data source .
a primary advantage of such an approach is the ease of use and integration with existing applications . over the last couple of years several similarity predicates
have been proposed for common quality primitives ( approximate selections , joins , etc . ) and have been fully expressed using declarative sql statements . in this thesis ,
new similarity predicates are proposed along with their declarative realization , based on notions of probabilistic information retrieval .
then , full declarative specifications of previously proposed similarity predicates in the literature are presented , grouped into classes according to their primary characteristics . finally , a thorough performance and accuracy study comparing a large number of similarity predicates for data cleaning operations is performed . .
And you have already written the first three sentences of the full article: the importance of data cleaning and quality technologies for business practices is well recognized .
data cleaning has been an active research topic in several communities including statistics , machine learning and data management .
the quality of data suffers from typing mistakes , lack of standards for recording database fields , integrity constraints that are not enforced , inconsistent data mappings , etc . for years.
Please generate the next two sentences of the article | , data quality technology has grown independently from core data management .
data quality tools became part of extract transform load ( etl ) technologies , commonly applied during the initial loading phase of data into a warehouse . |
7,783 | Suppose that you have an abstract for a scientific paper: superconductivity in cuprate superconductors occurs upon charge - carrier doping mott insulators , where a central question is what mechanism causes the loss of electrical resistance below the superconducting transition temperature ? in this review , we attempt to summarize the basic idea of the kinetic - energy driven superconducting mechanism in the description of superconductivity in cuprate superconductors .
the mechanism of the kinetic - energy driven superconductivity is purely electronic without phonons , where the charge - carrier pairing interaction in the particle - particle channel arises directly from the kinetic energy by the exchange of spin excitations in the higher powers of the doping concentration .
this kinetic - energy driven d - wave superconducting - state is controlled by both the superconducting gap and quasiparticle coherence , which leads to that the maximal superconducting transition temperature occurs around the optimal doping , and then decreases in both the underdoped and overdoped regimes .
in particular , the same charge - carrier interaction mediated by spin excitations that induces the superconducting - state in the particle - particle channel also generates the normal - state pseudogap state in the particle - hole channel . the normal - state pseudogap crossover temperature is much larger than the superconducting transition temperature in the underdoped and optimally doped regimes , and then monotonically decreases upon the increase of doping , eventually disappearing together with superconductivity at the end of the superconducting dome .
this kinetic - energy driven superconducting mechanism also indicates that the strong electron correlation favors superconductivity , since the main ingredient is identified into a charge - carrier pairing mechanism not from the external degree of freedom such as the phonon but rather solely from the internal spin degree of freedom of the electron .
the typical properties of cuprate superconductors discussed within the framework....
And you have already written the first three sentences of the full article: , coupling strength @xmath0 ) .
@xmath1 is the nel temperature , while the temperature below which superconductivity ( a pseudogap ) is observed is denoted by @xmath2 ( @xmath3 ) .
[ from ref . @xcite . ].
Please generate the next two sentences of the article | [ phase - diagram - exp ] ] after intensive investigations over more than two decades , it has become clear that cuprate superconductors are among the most complicated systems studied in condensed matter physics @xcite .
the complications arise mainly from that the parent compounds of cuprate superconductors are a form of non - conductor called a mott insulator with an antiferromagnetic ( af ) long - range order ( aflro ) @xcite , where a single common feature in the layered crystal structure is the presence of one to several cuo@xmath4 planes in the unit cell @xcite . |
7,784 | Suppose that you have an abstract for a scientific paper: we report the discovery with _ xmm - newton _ of an @xmath0 7 mhz x - ray ( 0.3 - 10.0 kev ) quasi - periodic oscillation ( qpo ) from the eclipsing , high - inclination black hole binary ic 10 x-1 .
the qpo is significant at @xmath1 4.33@xmath2 confidence level and has a fractional amplitude ( % rms ) and a quality factor , @xmath3 , of @xmath4 and @xmath5 , respectively .
the overall x - ray ( 0.3 - 10.0 kev ) power spectrum in the frequency range 0.0001 - 0.1 hz can be described by a power - law with an index of @xmath6 , and a qpo at 7 mhz . at frequencies
@xmath7 0.02 hz there is no evidence for significant variability . the fractional amplitude ( rms ) of the qpo is roughly energy - independent in the energy range of 0.3 - 1.5 kev . above 1.5 kev the low signal to noise ratio of the data does not allow us to detect the qpo . by directly comparing these properties with the wide range of qpos currently known from accreting black hole and neutron stars , we suggest that the 7 mhz qpo of ic 10 x-1 may be linked to one of the following three categories of qpos : ( 1 ) the `` heartbeat '' mhz qpos of the black hole sources grs 1915 + 105 and igr j17091@xmath83624 , or ( 2 ) the 0.6 - 2.4 hz `` dipper qpos '' of high - inclination neutron star systems , or ( 3 ) the mhz qpos of cygnus x-3 . .
And you have already written the first three sentences of the full article: the x - ray light curves of numerous accreting neutron star and stellar - mass black holes ( stmbhs ) show evidence for the presence of quasi - periodic oscillations ( qpos ) , which appear as finite - width peaks in their power density spectra ( pds ) ( see van der klis 2006 and mcclintock & remillard 2006 for reviews of neutron star and stmbh qpos ) . while it is known that qpos occur with a wide range of centroid frequencies a few mhz to above a khz in neutron stars and a few mhz to a few hundred hz in the case of stmbhs the exact nature of the physical processes producing such oscillations is still a mystery . based on the observed properties , that is , their centroid frequencies , widths , amplitudes , and overall nature of their power spectra , etc .
, qpos have been categorized into different groups . in neutron star
binaries the qpo phenomenon constitutes the _ kilohertz _ qpos ( centroid frequencies in the range of 300 - 1200 hz : see the review by van der klis 2000 ) seen from over two dozen sources ( e.g. , mndez et al ..
Please generate the next two sentences of the article | 2001 ; barret et al .
2008 and references therein ) , the _ hectohertz _ qpos ( @xmath9100 - 300 hz : e.g. , van straaten et al . 2003 ; altamirano et al . |
7,785 | Suppose that you have an abstract for a scientific paper: the solution of the time - dependent schrdinger equation is discussed for a particle confined in half - space @xmath0 with a linear potential @xmath1 in the following situations : ( a ) sudden removal of the wall and switching on the linear potential @xmath1 at @xmath2 , ( b ) sudden removal of the wall and the potential and ( c ) sudden removal of the potential .
a brief discussion of the quantum statistic is presented . .
And you have already written the first three sentences of the full article: the quantum mechanical effects resulting from time - dependent boundary conditions have been studied by some authors @xcite . diffraction in time
was initially introduced by moshinsky @xcite by considering a situation involving a beam of particles impinging from the left on a totally absorbing shutter located at the origin which is suddenly turned off at an instant . in such an example
, the transient probability current has a close mathematical resemblance with the intensity of light resulting from the fresnel diffraction by a straight edge ..
Please generate the next two sentences of the article | see @xcite for a recent review .
an interesting feature of the solutions for cutoff initial waves , occurring both in the free case @xcite and in the presence of a potential interaction @xcite , is that , if initially there is a zero probability for the particle to be at @xmath3 , as soon as @xmath4 , there is instantaneously , a finite , though very small , probability to find the particle at any point @xmath3 . |
7,786 | Suppose that you have an abstract for a scientific paper: we study a class of quantum measurement models .
a microscopic object is entangled with a macroscopic pointer such that a distinct pointer position is tied to each eigenvalue of the measured object observable .
those different pointer positions mutually decohere under the influence of an environment . overcoming limitations of previous approaches we ( i )
cope with initial correlations between pointer and environment by considering them initially in a metastable local thermal equilibrium , ( ii ) allow for object - pointer entanglement and environment - induced decoherence of distinct pointer readouts to proceed simultaneously , such that mixtures of macroscopically distinct object - pointer product states arise without intervening macroscopic superpositions , and ( iii ) go beyond the markovian treatment of decoherence . .
And you have already written the first three sentences of the full article: the interpretation and theoretical description of measurements on quantum systems have been under debate since the birth of quantum theory @xcite .
more recently , interest for this question has been revived by new developments in quantum information .
quantum detection can be used either to extract information on quantum states or to monitor quantum systems ( quantum trajectories @xcite , quantum zeno effect @xcite ) ..
Please generate the next two sentences of the article | quantitative treatments of measurement models serve both to elucidate the self - consistency of quantum theory and its interpretation , and to calculate the time scales relevant for experiments .
data for the decoherence time are in fact accumulating , in microwave cavities @xcite , in solid state devices like superconducting tunnel junction nanocircuits @xcite , and in electron beams interacting with a semiconducting plate @xcite . on a more fundamental ground , ever larger classes of nonlocal |
7,787 | Suppose that you have an abstract for a scientific paper: we perform numerical simulations to study the secular orbital evolution and dynamical structure in the hd 69830 planetary system with the best - fit orbital solutions by lovis and coworkers ( 2006 ) . in the simulations , we show that the triplet neptunian system can be stable at least for 2 gyr and the stability would not be greatly influenced even if we vary the planetary masses from neptune - mass to jupiter - mass .
in addition , we employ the laplace - lagrange secular theory to investigate the long - term behaviors of the system , and the outcomes demonstrate that this theory can well describe and predict the secular orbital evolution for three neptune - mass planets , where the secular periods and amplitudes in the eccentricities are in good agreement with those of the direct numerical integrations .
we first reveal that the secular periods of the eccentricity @xmath0 and @xmath1 are identical about 8,300 yr , i.e. , @xmath2 ( @xmath3 are respectively , the eigenfrequencies of the system ) , while the secular variation of @xmath4 for the outermost planet has a period of @xmath5 yr .
moreover , we extensively explore the planetary configuration of three neptune - mass companions with one massive terrestrial planet residing in 0.07 au @xmath6 au , to examine the asteroid structure in this system .
we underline that there are stable zones at least @xmath7 yr for low - mass terrestrial planets locating between 0.3 and 0.5 au , and 0.8 and 1.2 au with final eccentricities of @xmath8 .
still , we also find that the secular resonance @xmath9 and @xmath10 arising from two inner planets can excite the eccentricities of the terrestrial bodies , and the accumulation or depletion of the asteroid belt are also shaped by orbital resonances of the outer planets , for example , the asteroidal gaps at 2:1 and 3:2 mean motion resonances ( mmrs ) with planet c , and 5:2 and 1:2 mmrs with planet d. in a dynamical sense , the proper candidate regions for the existence of the potential terrestrial planets or....
And you have already written the first three sentences of the full article: to date , more than 200 extrasolar planets have been discovered about the nearby stars within 200 pc ( butler et al .
2006 ; the extrasolar planets encyclopaedia ) mostly by the measurements of doppler surveys and transiting techniques .
the increasing numbers of the extrasolar planets are greatly attributed to the increasing of precision of measurement . at present , the observational precision has been achieved to @xmath13 ms@xmath14 to @xmath15 ms@xmath14 , whereas most observations currently have lower precision ..
Please generate the next two sentences of the article | the improvement of the observations will indeed induce the substantial discovery : ( 1)plentiful multiple systems , which @xmath16 multiple system involved in orbital resonance and secular interactions now have been detected ; ( 2 ) much more low - mass companions around main - sequence stars ( from neptune - mass to earth - mass , so - called super - earths ) , e.g. , 55 cancri ( mcarthur et al .
2004 ) , gj 876 ( rivera et al . 2005 ) , hd 160691 ( santos et al . 2004 ; gozdziewski et al . |
7,788 | Suppose that you have an abstract for a scientific paper: this work concerns with the @xmath0-fold binary asymmetric channels ( @xmath1 ) .
an equivalence relation between two channels can be characterized by both having the same decision criterion when maximum likelihood is considered .
we introduce here a function @xmath2 ( the bac - function ) such that the parameters @xmath3 of the binary channel which determine equivalent channels belong to certain region delimited by its level curves .
explicit equations determining these regions are given and the number of different @xmath4 classes is determined .
a discusion on the size of these regions is also presented . .
And you have already written the first three sentences of the full article: the binary asymmetric channel @xmath5 is the discrete memoryless channel with binary alphabet and transition probability given by @xmath6 and @xmath7 , where @xmath8 denote the probability of receiving @xmath9 if @xmath10 was sent . without loss of generality
we will assume @xmath11 and @xmath12 ( see discussion in section [ sectionfurtherremarks ] ) .
+ there are two extreme cases of binary asymmetric channels : the binary symmetric channels @xmath13 with @xmath14 and the z - channels @xmath15 with @xmath16 ..
Please generate the next two sentences of the article | we may say that all binary symmetric channels are equivalent from the point of view of encoding and decoding , and the same can be said regarding the z - channels . to be more precise ,
let @xmath17 and @xmath18 be two binary symmetric channels or two @xmath19-channels and let @xmath20 denotes the error probability of the code @xmath21 according to the channel @xmath22 . on the encoding part , given two @xmath0-block codes @xmath23 ( for some @xmath24 ) we have that @xmath25 if and only if @xmath26 . |
7,789 | Suppose that you have an abstract for a scientific paper: phase transitions of fluid mixtures of the type introduced by stillinger and helfand are studied using a continuum version of the invaded cluster algorithm .
particles of the same species do not interact , but particles of different types interact with each other via a repulsive potential .
examples of interactions include the gaussian molecule potential and a repulsive step potential .
accurate values of the critical density , fugacity and magnetic exponent are found in two and three dimensions for the two - species model .
the effect of varying the number of species and of introducing quenched impurities is also investigated . in all the cases studied , mixtures of @xmath0-species are found to have properties similar to @xmath0-state potts models . .
And you have already written the first three sentences of the full article: several years ago stillinger and helfand@xcite introduced a simple but nontrivial model of fluid demixing .
their original model consists of a binary mixture of @xmath1 and @xmath2 particles .
particles of the same type do not interact with one another , but @xmath1 and @xmath2 particles interact with a repulsive potential such that the mayer @xmath3-function is a gaussian ..
Please generate the next two sentences of the article | this choice for the @xmath4 potential , known as the gaussian molecule potential , greatly simplifies the calculation of virial coefficients and most work for this potential has been done using series methods@xcite .
the main motivation for this work is to confirm ising universality for the critical exponents of continuum systems . in this paper |
7,790 | Suppose that you have an abstract for a scientific paper: a detailed numerical study is presented of the slow diffusion ( arnold diffusion ) taking place around resonance crossings in nearly integrable hamiltonian systems of three degrees of freedom in the so - called ` nekhoroshev regime ' .
the aim is to construct estimates regarding the speed of diffusion based on the numerical values of a truncated form of the so - called remainder of a normalized hamiltonian function , and to compare them with the outcomes of direct numerical experiments using ensembles of orbits . in this comparison
we examine , one by one , the main steps of the so - called analytic and geometric parts of the nekhoroshev theorem .
thus : i ) we review and implement an algorithm @xcite for hamiltonian normalization in multiply resonant domains which is implemented as a computer program making calculations up to a high normalization order .
ii ) we compute the dependence of the optimal normalization order on the small parameter @xmath0 in a specific model and compare the result with theoretical estimates on this dependence .
iii ) we examine in detail the consequences of assuming simple convexity conditions for the unperturbed hamiltonian on the geometry of the resonances and on the phase space structure around resonance crossings .
iv ) we discuss the dynamical mechanisms by which the remainder of the optimal hamiltonian normal form drives the diffusion process . through these steps
, we are led to two main results : i ) we construct in our concrete example a convenient set of variables , proposed first by benettin and gallavotti @xcite , in which the phenomenon of arnold diffusion in doubly resonant domains can be clearly visualized .
ii ) we determine , by numerical fitting of our data the dependence of the local diffusion coefficient @xmath1 on the size @xmath2 of the optimal remainder function , and we compare this with a heuristic argument based on the assumption of normal diffusion .
we find a power law @xmath3 , where the constant @xmath4 has a small positive value....
And you have already written the first three sentences of the full article: the study of _ diffusion _ in nearly - integrable hamiltonian dynamical systems of the form @xmath5 where @xmath6 are n - dimensional action - angle variables and @xmath0 is a small parameter , constitutes a central problem in hamiltonian dynamical systems theory , in view , in particular , of its multiple applications in physics and astronomy ( see @xcite@xcite for an introduction , the basic review paper @xcite , or @xcite@xcite
@xcite for recent advanced reviews emphasizing various aspects of this subject ) .
it is a well established result that , if @xmath7 , and @xmath8 satisfies appropriate convexity and analyticity conditions ( see section 2 below ) , two distinct regimes characterize the laws of diffusion as a function of @xmath0 : for @xmath9 , where @xmath10 is a threshold value , the onset of the so - called ` nekhoroshev regime ' takes place @xcite@xcite@xcite @xcite@xcite@xcite . in this case.
Please generate the next two sentences of the article | , the nekhoroshev theorem provides an @xmath11 $ ] upper bound for the speed of diffusion .
the exponent @xmath12 depends on the number of degrees of freedom @xmath13 , while its precise value in local domains of the action space depends also on the multiplicity of the resonance conditions holding in such domains ( see e.g. @xcite@xcite@xcite ) . |
7,791 | Suppose that you have an abstract for a scientific paper: though topological aspects of energy bands are known to play a key role in quantum transport in solid - state systems , the implications of floquet band topology for transport in momentum space ( i.e. , acceleration ) are not explored so far . using a ratchet accelerator model inspired by existing cold - atom experiments , here we characterize a class of extended floquet bands of one - dimensional driven quantum systems by chern numbers , reveal topological phase transitions therein , and
theoretically predict the quantization of adiabatic transport in momentum space .
numerical results confirm our theory and indicate the feasibility of experimental studies . in both classical mechanics and quantum mechanics , position and momentum variables form a conjugate pair and can hence be treated on the same footing from a phase space perspective .
the real physical world , however , does not have position - momentum symmetry .
for example , energy bands of a solid are formed because electronic hamiltonians are periodic in position but not in momentum .
due to such unequal roles of position and momentum , the mapping of quantum transport phenomena from position space to momentum space is typically nontrivial but , where possible , may lead to important insights and unforeseen opportunities .
anderson localization , for instance , was first discovered as a seminal result of quantum transport in position space .
its analog in momentum space was later found to be behind the intriguing phenomenon of dynamical localization " @xcite .
this mapping has stimulated fruitful studies of anderson transition in driven cold - atom systems @xcite . as a second example , ratchet transport , namely , directed transport under a zero mean force in position space , has been mapped to momentum space as well , leading to the finding of ratchet accelerators ( ra ) @xcite .
energy - band topology is of fundamental interest to studies of quantum transport in condensed - matter physics .
the issue to be addressed....
And you have already written the first three sentences of the full article: we use the same notation as introduced in the main text .
the floquet propagator of a on - resonance double - kicked rotor is given by @xmath103 with eigenstates and eigenvalues denoted by @xmath104 here @xmath52 represent the bloch eigenstates of @xmath105 with bloch phase @xmath106 , due to momentum - space periodicity of period @xmath107 for @xmath108 .
using the bloch theorem , one rewrites @xmath109 as @xmath110 here @xmath111 holds for all momentum eigenstates @xmath112 ..
Please generate the next two sentences of the article | we adopt the normalization convention @xmath113 . with this normalization convention
, it can be shown that the identity operator in terms of the bloch eigenstates is given by @xmath114 and their inner products are given by @xmath115 which implies that the initial states we considered in the main text [ see also eq . |
7,792 | Suppose that you have an abstract for a scientific paper: we study the ground state pair - correlation properties of a weakly interacting trapped bose gas in three dimension by using a correlated many - body method .
use of the van der waals interaction potential and an external trapping potential shows realistic features .
we also test the validity of shape - independent approximation in the calculation of correlation properties . .
And you have already written the first three sentences of the full article: the last two decades have been witness to intense activities in experimental and theoretical study of correlation properties of interacting quantum systems .
the problem is still challenging and open in the quantum many - body systems which are non - integrable .
the task becomes simplified for integrable systems like one dimensional uniform bose gas described by the lieb - liniger ( ll ) model [ 1,2 ] , which assumes that particles interact via a @xmath0-function repulsive potential ..
Please generate the next two sentences of the article | since the experimental observation of bose einstein condensate ( bec ) in ultracold trapped alkali atomic vapors , a lot of theoretical and experimental work has been done to study its correlation properties [ 3 - 12 ] . in the recent experimental situation
, it is easy to achieve a quasi - one - dimensional strongly interacting degenerate bose gas in a highly anisotropic trap [ 13 - 15 ] which is correctly described by the lieb - liniger model [ 16 ] . |
7,793 | Suppose that you have an abstract for a scientific paper: in this paper , we address the issue of the stability of the thermal equilibrium of large quantum systems with respect to variations of the thermal contact between them .
we study the schrdinger time evolution of a free bosonic field in two coupled one - dimensional cavities after a sudden change of the contact between the cavities . though the coupling we consider is thermodynamically small , modifying it has a considerable impact on the two - point correlation functions of the system .
we find that they do not return to equilibrium but essentially oscillate with a period proportional to the length of the cavities .
we compare this coupled cavities system with the perfect gas which is described by similar expressions but behaves very differently . .
And you have already written the first three sentences of the full article: the physically relevant degrees of freedom of a large isolated system initially out of equilibrium , are expected to relax to their thermal equilibrium values .
obviously , no relaxation behavior can be observed for the complete quantum state of the system but interesting degrees of freedom can evolve irreversibly in the limit of a large system .
this issue of thermalisation in isolated quantum systems has been principally investigated by considering composite systems consisting of two distinguishable subsystems of very different sizes . for such systems , the smaller subsystem relaxes to thermal equilibrium if the larger one is assumed to be in an equilibrium mixed state @xcite ..
Please generate the next two sentences of the article | recently , it has been shown that a priori thermal averaging is not essential .
the small subsystem can thermalise whereas the whole isolated system is in a pure quantum state @xcite . |
7,794 | Suppose that you have an abstract for a scientific paper: we formulate a theory of current - induced spin torques in inhomogeneous iii - v ferromagnetic semiconductors . the carrier spin-3/2 and large spin - orbit interaction , leading to spin non - conservation , introduce significant conceptual differences from spin torques in ferromagnetic metals .
we determine the spin density in an electric field in the weak momentum scattering regime , demonstrating that the torque on the magnetization is intimately related to spin precession under the action of both the spin - orbit interaction and the exchange field characteristic of ferromagnetism .
the spin polarization excited by the electric field is smaller than in ferromagnetic metals and , due to lack of angular momentum conservation , can not be expressed in a simple closed vectorial form .
remarkably , scalar and spin - dependent scattering do not affect the result .
we use our results to estimate the velocity of current - driven domain walls . .
And you have already written the first three sentences of the full article: over a decade ago , slonczewski @xcite and berger @xcite predicted that an electrical current induces a torque on the magnetization of a ferromagnetic metal , and subsequent research has since identified distinct contributions called the reactive spin transfer torque and the dissipative spin transfer torque , sometimes referred to as adiabatic and non - adiabatic , respectively .
@xcite progress on the understanding of this effect in metals has been steady , @xcite and the field has been stimulated by applications in spintronics and nanotechnology , as a way to manipulate magnetization and thus information .
current - induced spin torques arise from a small mismatch between the spin polarization of conduction electrons and the magnetization present throughout a material , and reflect the nonlocal nature of magnetization dynamics in inhomogeneous systems ..
Please generate the next two sentences of the article | @xcite they are the converse of processes such as giant magnetoresistance ( gmr ) .
the calculation of spin torques is equivalent to finding the conduction - electron spin density in an electric field , and in metals they can be easily expressed as the divergence of the spin current . @xcite |
7,795 | Suppose that you have an abstract for a scientific paper: for the two dimensional kinetic ising model at finite temperature , the local mean magnetisation @xmath0 , simply related to the fraction of time spent by a given spin in the positive direction , has a limiting distribution , singular at @xmath1 , the onsager spontaneous magnetization .
the exponent of this singularity defines the persistence exponent @xmath2 .
we also study first passage exponents associated to persistent large deviations of @xmath3 , and their temperature dependence .
epsf _ submitted for publication to _ in this work we present a new approach to the study of persistence for systems undergoing phase ordering @xcite at finite temperature , which we shall illustrate on the case of the two dimensional ising model . in this approach persistence appears as a stationary property of the coarsening system , and the role of the onsager spontaneous magnetization at equilibrium @xmath4 is made apparent , thus revealing new fundamental features of phase ordering .
it departs from previous approaches to finite temperature persistence @xcite , where these features did not appear .
consider a system of ising spins @xmath5 located at sites @xmath6 , started from a random initial condition , and evolving under the heat bath dynamics at fixed temperature below the critical temperature . at each time
step a spin is picked at random , and updated with the probability @xmath7 where the sum runs over the neighbours of site @xmath8 . under this dynamics spins thermalize in their local environment .
therefore the system coarsens , i.e. domains of opposite signs grow and , in the scaling regime , the system is statistically self similar , with only one single characteristic length scale , which is the size of a typical domain @xcite . the question of persistence is to determine the fraction of space @xmath9 which remained in the same phase up to time @xmath10 @xcite ( or from time @xmath11 to time @xmath12 ) . for the two dimensional ising model at zero temperature ,
two phases....
And you have already written the first three sentences of the full article: .
Please generate the next two sentences of the article | |
7,796 | Suppose that you have an abstract for a scientific paper: a differential , membrane - based nanocalorimeter for general specific heat studies of very small samples , ranging from @xmath0 to sub-@xmath1 in mass , is described .
the calorimeter operates over the temperature range from above room temperature down to @xmath2 .
it consists of a pair of cells , each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane , in total giving a background heat capacity less than @xmath3 at @xmath4 , decreasing to @xmath5 at @xmath6 .
the device has several distinctive features : i ) the resistive thermometer , made of a @xmath7 alloy , displays a high dimensionless sensitivity @xmath8 over the entire temperature range .
ii ) the sample is placed in direct contact with the thermometer , which is allowed to self - heat .
the thermometer can thus be operated at high dc current to increase the resolution .
iii ) data are acquired with a set of eight synchronized lock - in amplifiers measuring dc , @xmath9 and @xmath10 harmonic signals of heaters and thermometer .
this gives high resolution and allows continuous output adjustments without additional noise .
iv ) absolute accuracy is achieved via a variable - frequency - fixed - phase technique in which the measurement frequency is automatically adjusted during the measurements to account for the temperature variation of the sample heat capacity and the device thermal conductance .
the performance of the calorimeter is illustrated by studying the heat capacity of a small au sample and the specific heat of a @xmath11 piece of superconducting pb in various magnetic fields . .
And you have already written the first three sentences of the full article: accurate thermodynamic measurements are essential to understand fundamental properties of materials in various fields of physics . in condensed matter ,
the measurement of specific heat is a central characterization applicable to all kind of materials .
low - temperature calorimetry is particularly suited for the investigation of superconductors and other novel systems with electronic phase transitions.@xcite such measurements require high resolution , since the electronic contribution to the heat capacity is only a minor part of the total heat capacity , except at the very lowest temperatures ..
Please generate the next two sentences of the article | the high resolution can be achieved through differential calorimeter designs and various temperature - modulated techniques.@xcite good accuracy is also often needed .
the temperature dependence of the specific heat may , for instance , reveal central aspects of the nature of the electronic system , including energy gap structure , anisotropy , and possible signatures of quantum phase transitions . |
7,797 | Suppose that you have an abstract for a scientific paper: we present a security analysis of the recently introduced quantum private query ( qpq ) protocol .
it is a cheat sensitive quantum protocol to perform a private search on a classical database .
it allows a user to retrieve an item from the database without revealing which item was retrieved , and at the same time it ensures data privacy of the database ( the information that the user can retrieve in a query is bounded and does not depend on the size of the database ) .
the security analysis is based on information - disturbance tradeoffs which show that whenever the provider tries to obtain information on the query , the query ( encoded into a quantum system ) is disturbed so that the person querying the database can detect the privacy violation . .
And you have already written the first three sentences of the full article: in its most basic form , the scenario we consider can be described as follows .
on one side we have a provider , bob , who controls an ordered classical database composed of @xmath0 memory cells .
each cell of the data - base contains an @xmath1 bit string , so that the database consists of @xmath2 strings @xmath3 . on the other side.
Please generate the next two sentences of the article | , we have the person querying the database , alice , who wants to recover the string associated with a memory cell ( say the @xmath4-th one ) but at the same time does not want bob to know which cell she is interested in ( _ user privacy _ ) . in a purely classical setting the simplest strategy for alice consists in placing a large number of decoy queries , i.e. she `` hides '' her query among a large number @xmath5 of randomly selected queries . in this case
, she will be able to get the information she is looking for , while limiting bob s intrusion in her privacy . [ in fact , the mutual information between alice s true query @xmath4 and bob s estimate of such value is upper bounded by @xmath6 . |
7,798 | Suppose that you have an abstract for a scientific paper: we investigate the well - measured spectral and energetic properties of 20 gamma - ray bursts ( grbs ) in their cosmological rest frames . we find a tight relation between the isotropic - equivalent @xmath0-ray energy @xmath1 , the local peak energy @xmath2 of the @xmath3 spectrum , and the local break time @xmath4 of the grb afterglow light curve , which reads @xmath5 ( @xmath6 ; @xmath7 , @xmath8 ) .
such a power - law relation can be understood via the high - energy radiation processes for the grb prompt emission accompanying the beaming effects .
we then consider this relation as an intrinsic one for the observed grb sample , and obtain a constraint on the mass density @xmath9 ( @xmath10 ) for a flat @xmath11cdm universe , and a @xmath12 for @xmath13 and @xmath14 .
ongoing grb observations in the _ swift _ era are expected to confirm this relation and make its cosmological utility progress much . .
And you have already written the first three sentences of the full article: gamma - ray bursts ( grbs ) are the most powerful explosions in the universe since the big bang .
their cosmological origins are identified by the redshift measurements of their exploded remnants , usually named `` grb afterglows '' , or their host galaxies .
grbs are common regarded as jetted phenomena , supported by the observational evidence that an achromatic break appears in the afterglow light curve , which declines more steeply than in the spherical model largely due to the edge effect and the laterally spreading effect ( rhoads 1999 ; sari et al . 1999 ) or the off - axis viewing effect ( rossi , lazzati & rees 2002 ; zhang & mszros 2002a ; berger et al ..
Please generate the next two sentences of the article | 2003 ) . with the advantages of huge energy release for the prompt emission and immunity to dust extinction for the @xmath0-ray photons
, grbs are widely believed to be detectable out to a very high redshift of @xmath15 ( lamb & reichart 2000 ; ciardi & loeb 2000 ; bromm & loeb 2002 ; gou et al . 2004 ) . |
7,799 | Suppose that you have an abstract for a scientific paper: it is shown how the exchange interaction , the dipole - dipole interaction , and the dzyaloshinsky - moriya interaction between electronic spin - density fluctuations emerge naturally from a field - theoretic framework that couples electrons to the fluctuating electromagnetic potential .
semi - quantitative estimates are given to determine when the dipole - dipole interaction , which is often neglected , needs to be considered , and various applications are discussed , with an emphasis on weak ferromagnets and on helimagnets . .
And you have already written the first three sentences of the full article: understanding the origin of ferromagnetism was one of the success stories of applying quantum mechanics to solid - state systems .
classically , magnetic moments interact via the dipole - dipole interaction , which is much too weak to explain magnetic order at as high a temperature as is observed in , e.g. , iron or nickel.@xcite the explanation of this conundrum was found to be the exchange interaction mechanism , which leads to a spin - spin interaction that is governed by the coulomb interaction via the pauli principle .
this was first understood in the context of atomic and molecular physics in the 1920s , and applied to solid - state physics in the 1950s.@xcite somewhat ironically , a straightforward application of the exchange interaction concept leads to a spin - spin interaction that is too strong , as the relevant energy scale is the atomic scale , or roughly @xmath0 ..
Please generate the next two sentences of the article | many - body and band - structure effects renormalize this scale and bring it down to the observed ferromagnetic scale of rougly @xmath1 or lower.@xcite this is still much larger than the dipole - dipole scale , and the latter is often neglected in the discussion of ferromagnets .
when it is considered , e.g. , for its influence on the critical behavior,@xcite it is usually added phenomenologically to models that describe the exchange interaction . |
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