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5,600 | Suppose that you have an abstract for a scientific paper: a quite unusual diffuse scattering phenomenology was observed in the single - crystal x - ray diffraction pattern of cubic perovskite bmt ( @xmath0 ) .
the intensity of the scattering is parametrized as a set of cube - like objects located at the centers of reciprocal space unit cells , resembling very broad and cubic - shaped ( 1/2,1/2,1/2)-satellites .
bmt belongs to perovskites of formula ab@xmath1b@xmath2o@xmath3 ( a = mg , b@xmath4ta , b@xmath5 mg ) .
the cubes of the intensity can be attributed to the partial correlations of the occupancies of the b site .
the pair correlation function is the fourier transform of the diffuse scattering intensity and the latter s idealized form yields the unusual property of a power - law correlation decay with distance . up to now
this is observed only in a few exotic instances of magnetic order or nematic crystals .
therefore it can not be classified as a short - range order phenomenon , as in most situations originating diffuse scattering . a monte - carlo search in configuration space yielded solutions that reproduce faithfully the observed diffuse scattering .
analysis of the results in terms of the electrostatic energy and the entropy point to this phase of bmt as a metastable state , kinetically locked , which could be the equilibrium state just below the melting point . .
And you have already written the first three sentences of the full article: an experiment using x - ray single crystal diffraction at the swiss - norwegian beam lines ( snbl ) of european synchrotron radiation facility ( esrf ) on a single crystal of cubic perovskite bmt ( @xmath0 ) has shown an interesting diffuse scattering pattern , consisting of cube - shaped domains of nearly constant intensity , with the centers located on the ( 1/2,1/2,1/2 ) points of the reciprocal lattice and with an edge of @xmath6 of a reciprocal lattice unit ( rlu ) .
all the cubes have the same intensity level , apart from the usual slow modulations due to atomic and thermal factors .
bmt belongs to perovskites of formula ab@xmath1b@xmath2o@xmath3 ( a = ba , b@xmath4ta , b@xmath5 mg ) where different species on the b - site can be ordered to various degrees ..
Please generate the next two sentences of the article | the scattering depends on the site occupancy and when the ordering is directly related to the pair correlation function of the different atomic sites @xcite .
in fact , bmt in its cubic phase is necessarily intrinsically disordered in the b - site . in this paper |
5,601 | Suppose that you have an abstract for a scientific paper: the successful fabrication of single layer graphene has greatly stimulated the progress of the research on graphene . in this article , focusing on the basic electronic and transport properties of graphene nanoribbons ( gnrs ) , we review the recent progress of experimental fabrication of gnrs , and the theoretical and experimental investigations of physical properties and device applications of gnrs . we also briefly discuss the research efforts on the spin polarization of gnrs in relation to the edge states . .
And you have already written the first three sentences of the full article: graphene , one monolayer of carbon atoms tightly packed into a two - dimensional honeycomb lattice , is actively being pursued as a material for next - generation electronics due to its promising electronic properties , such as high carrier mobility @xcite , long phase coherence lengths @xcite . on the other side ,
the unique two - dimensional atomic structure of graphene implies unique confinement on electron system and offers a perfect platform to explore the amazing physics phenomenons , such as quantum hall effect @xcite and massless dirac fermions @xcite .
the first task for experimentalists to study graphene electronics is to fabricate high quality single layer graphene . until now.
Please generate the next two sentences of the article | , several different experimental methods have been proposed and realized to prepare single layer ( or few layers ) graphene , including mechanical exfoliation of highly oriented pyrolytic graphite @xcite , patterned epitaxially grown graphene on silicon carbide or transition metal ( e.g. ru , ni ) substrates @xcite , liquid - phase exfoliation of graphite @xcite , substrate - free gas - phase synthesis @xcite , and chemical vapor deposition @xcite .
the success in fabricating single layer graphene has stimulated the extensive research efforts ( both theoretical and experimental ) in graphene related research area . |
5,602 | Suppose that you have an abstract for a scientific paper: magnetic field dependent universal conductance fluctuations ( ucf s ) are observed in weakly disordered indium tin oxide nanowires from 0.26 k up to @xmath0 k. the fluctuation magnitudes increase with decreasing temperature , reaching a fraction of @xmath1 at @xmath2 k. the shape of the ucf patterns is found to be very sensitive to thermal cycling of the sample to room temperatures , which induces irreversible impurity reconfigurations . on the other hand , the ucf magnitudes are insensitive to thermal cycling . our measured temperature dependence of the root - mean - square ucf magnitudes are compared with the existing theory [ c. w. j. beenakker and h. van houten , phys . rev .
b * 37 * , 6544 ( 1988 ) ] . a notable discrepancy is found , which seems to imply that the experimental ucf s are not cut off by the thermal diffusion length @xmath3 , as would be expected by the theoretical prediction when @xmath4 , where @xmath5 is the electron dephasing length .
the approximate electron dephasing length is inferred from the ucf magnitudes and compared with that extracted from the weak - localization magnetoresistance studies . a reasonable semiquantitative agreement is observed . .
And you have already written the first three sentences of the full article: universal conductance fluctuations ( ucf s ) are one of the most meaningful manifestations of the quantum - interference electron transport in mesoscopic and nanoscale systems .
@xcite in weakly disordered miniature metals and at low temperatures , the aperiodic " ucf patterns are highly reproducible .
those fluctuation patterns are determined by the specific impurity configuration that is frozen " in a given sample at a given cooldown ..
Please generate the next two sentences of the article | @xcite under such conditions , one may sweep a magnetic field @xcite or gate voltage @xcite sufficiently widely to realize statistically distinct subsystems ( independent members ) of the specific ensemble which embraces the given sample under study .
the sample may then be thermally cycled up to room temperatures to induce possible rearrangement of the impurity configuration . |
5,603 | Suppose that you have an abstract for a scientific paper: we have explored the ideas that parametric resonance affects nearly geodesic motion around a black hole or a neutron star , and that it may be relevant to the high frequency ( twin ) quasi - periodic oscillations occurring in some low - mass x - ray binaries .
we have assumed the particles or fluid elements of an accretion disc to be subject to an isotropic perturbation of a hypothetical but rather general form .
we find that the parametric resonance is indeed excited close to the radius where epicyclic frequencies of radial and meridional oscillations are in a @xmath0 ratio .
the location and frequencies of the highest amplitude excitation vary with the strength of the perturbation .
these results agree with actual frequency ratios of twin khz qpos that have been reported in some black hole candidates , and they may be consistent also with correlation of the twin peaks in sco x-1 . .
And you have already written the first three sentences of the full article: pairs of high frequencies , known as kilohertz quasi - periodic oscillations ( khz qpos ) , have been detected in the x - ray emission of low - mass x - ray binaries ( lmxbs ) for more than 20 neutron stars and several black holes .
it has been suggested that a non - linear resonance within an accretion disc in a general - relativistic space - time metric plays a role in the excitation of the two oscillations ( abramowicz & kluniak 2001 , kluniak & abramowicz 2001 ) .
it is now recognized that the frequencies of the two peaks in the power spectrum of x - ray variability in black holes are in rational ratios , @xmath1 , with @xmath2 for two sources , and @xmath3 in a third source ( abramowicz & kluniak 2001 ; kluniak & abramowicz 2002 ; remillard et al ..
Please generate the next two sentences of the article | 2002 , abramowicz et al .
these black hole qpos are thought to have stable frequencies , and until the discovery of the puzzling rational ratios they have been thought to correspond to a trapped g - mode or c - mode of disc oscillation in the kerr metric ( okazaki et al . |
5,604 | Suppose that you have an abstract for a scientific paper: density functional calculations are performed to investigate the experimentally - reported field - induced phase transition in thin - film zro@xmath0 ( j. m@xmath1ller _ et al .
_ , nano .
lett .
12 , 4318 ) .
we find a small energy difference of @xmath2 1 mev / f.u . between the nonpolar tetragonal and polar orthorhombic structures , characteristic of antiferroelectricity .
the requisite first - order transition between the two phases , which atypically for antiferroelectrics have a group - subgroup relation , results from coupling to other zone - boundary modes , as we show with a landau - devonshire model .
tetragonal zro@xmath0 is thus established as a previously unrecognized lead - free antiferroelectric with excellent dielectric properties and compatibility with silicon .
in addition , we demonstrate that a ferroelectric phase of zro@xmath0 can be stabilized through epitaxial strain , and suggest an alternative stabilization mechanism through continuous substitution of zr by hf .
2.5 in 0.5 in # 1 # 1 # 1 # 1 # 1 zirconia ( zro@xmath0 ) is a high - k dielectric @xcite , chemically and structurally similar to hfo@xmath0 , and likewise is a candidate for dynamic random access memory ( dram ) applications @xcite and complementary metal - oxide - semiconductor ( cmos ) devices @xcite .
bulk zro@xmath0 has a high - symmetry cubic ( _ fm@xmath3 m _ ) structure ( fig .
[ fig : zro2-phases](a ) ) above 2400 k , and a tetragonal ( _ p4@xmath0/nmc _ ) structure ( fig .
[ fig : zro2-phases](b ) ) between 2400 k and 1200 k @xcite .
the tetragonal structure is related to the cubic structure by freezing in an unstable @xmath4 mode @xcite and is nonpolar . below 1200 k , zro@xmath0 is monoclinic ( _ p2@xmath5/c _ ) ( fig .
[ fig : zro2-phases](c ) ) .
the first - order transition from the tetragonal phase to the monoclinic phase changes the coordination number of zr from 8 to 7 and increases the volume by @xmath2 5 % . in light of the extensive research which....
And you have already written the first three sentences of the full article: we thank s. v. kalinin , t. mikolajick , j. m@xmath1ller , t. schenk , d. g. schlom , u. schr@xmath26der , and d. vanderbilt for valuable discussions . s.e.r .-
l . would like to thank s. trolier - mckinstry and c. randall for their hospitality at mri - penn state .
this work was supported by the office of naval research grant no ..
Please generate the next two sentences of the article | n00014 - 12 - 1 - 1040 .
l . would also like to thank the support of conicyt and the sponsor of fulbright foundation . |
5,605 | Suppose that you have an abstract for a scientific paper: the fixed - point index of a homeomorphism of jordan curves measures the number of fixed - points , with multiplicity , of the extension of the homeomorphism to the full jordan domains in question .
the now - classical circle index lemma says that the fixed - point index of a positive - orientation - preserving homeomorphism of round circles is always non - negative .
we begin by proving a generalization of this lemma , to accommodate jordan curves bounding domains which do not disconnect each other .
we then apply this generalization to give a new proof of schramm s incompatibility theorem , which was used by schramm to give the first proof of the rigidity of circle packings filling the complex and hyperbolic planes .
as an example application , we include outlines of proofs of these circle packing theorems .
we then introduce a new tool , the so - called torus parametrization , for working with fixed - point index , which allows some problems concerning this quantity to be approached combinatorially .
we apply torus parametrization to give the first purely topological proof of the following lemma : given two positively oriented jordan curves , one may essentially prescribe the images of three points of one of the curves in the other , and obtain an orientation - preserving homeomorphism between the curves , having non - negative fixed - point index , which respects this prescription .
this lemma is essential to our proof of the incompatibility theorem . .
And you have already written the first three sentences of the full article: this article is concerned with a topological quantity , the so - called _ fixed - point index _ of a homeomorphism of jordan curves , which has proven useful in the study of various areas of complex analysis .
we begin with its definition : a _ jordan curve _ is a homeomorphic image of a topological circle @xmath0 in the complex plane @xmath1 .
jordan domain _ is a bounded open set in @xmath1 with jordan curve boundary ..
Please generate the next two sentences of the article | we use the term _ closed jordan domain _ or _ compact jordan domain _ to refer to the closure of a jordan domain .
we define the _ positive orientation _ on a jordan curve as usual . |
5,606 | Suppose that you have an abstract for a scientific paper: the stellar density distribution of the bulge is analyzed through one of its tracers .
we use oxygen - rich miras variables from the catchpole et al .
( 2016 ) survey and ogle - iii survey as standard candles .
the average age of these stars is around 9 gyr .
the population traced by mira variables matches a boxy bulge prediction , not an x - shaped one , because only one peak is observed in the density along the analyzed lines of sight , whereas the prediction of an x - shape gives two clear peaks . .
And you have already written the first three sentences of the full article: the nature of the galactic bulge morphology has been discussed using different interpretations over the last decades .
its non - axisymmetry was quickly recognized with the arrival of the first near - infrared surveys ( e.g. , weiland et al .
1994 ; lpez - corredoira et al ..
Please generate the next two sentences of the article | 1997 ; babusiaux & gilmore 2005 ) , but its shape has not been free from debate .
a peanut shape was evident in the projection of the bulge , especially in infrared surveys covering the full sky , like cobe - dirbe , and extinction was considered to be responsible for the presence of the pronounced `` peanut shape '' waist located near @xmath0 , @xmath1 in the uncorrected dirbe maps of the bulge at 1.25 and 2.2@xmath2 m ( weiland et al . |
5,607 | Suppose that you have an abstract for a scientific paper: the non - local dielectric response theory is extended to describe oblique reflection of light from quantum wells subjected to the magnetic field .
this allows us to calculate the dispersion and polarization of the exciton - polariton modes in semiconductor microcavities in the presence of a magnetic field normal to the plane of the structure .
we show that due to the interplay between the exciton zeeman splitting and te - tm splitting of the photon modes , four polariton dispersion branches are formed with a polarization gradually changing from circular in the exciton - like part to linear in the photon - like part of each branch .
faraday rotation in quantum microcavities is shown to be strongly enhanced as compared with the rotation in quantum wells . .
And you have already written the first three sentences of the full article: cavity polaritons are half - light half - matter quasiparticles resulting from the strong coupling of the photon mode of a microcavity with an exciton resonance of the embedded semiconductor structure @xcite
. being mixed exciton - photon quasiparticles , the cavity polaritons have integer spins and can reveal bosonic properties @xcite responsible for a number of interesting effects both predicted and observed , namely , stimulated scattering @xcite , polariton lasing @xcite , bose - einstein condensation @xcite , superfluidity @xcite etc .
many important properties of the polaritonic systems are connected with their spin degree of freedom @xcite ..
Please generate the next two sentences of the article | it was shown that an external magnetic field strongly affects non - linear dynamics of the polaritons and optical properties of polariton condensates .
recently , the magnetic field induced suppression of polariton superfluidity and the so - called `` spin meissner effect '' have been predicted @xcite . for understanding of the rich variety of non - linear phenomena induced by magnetic field in microcavities a thorough knowledge of the linear properties of magneto - polaritons ( i.e. polaritons subject to a magnetic field ) is needed . though the problem on the surface seems simple it becomes really complex if the polarization of light is included into consideration . |
5,608 | Suppose that you have an abstract for a scientific paper: shift - and - add is an approach employed to mitigate the phenomenon of resolution degradation in images acquired through a turbulent medium . using this technique ,
a large number of consecutive short exposures is registered below the coherence time of the atmosphere or other blurring medium .
the acquired images are shifted to the position of the brightest speckle and stacked together to obtain high - resolution and high signal - to - noise frame .
+ in this paper we present a highly efficient method for determination of frames shifts , even if in a single frame the object can not be distinguished from the background noise .
the technique utilizes our custom genetic algorithm , which iteratively evolves a set of image shifts .
we used the maximal energy of stacked images as an objective function for shifts estimation and validate the efficiency of the method on simulated and real images of simple and complex sources .
obtained results confirmed , that our proposed method allows for the recovery of spatial distribution of objects even only 2% brighter than their background .
the presented approach extends significantly current limits of image reconstruction with the use of shift - and - add method .
the applications of our algorithm include both the optical and the infrared imaging .
our method may be also employed as a digital image stabilizer in extremely low light level conditions in professional and consumer applications .
+ https://www.osapublishing.org/ol/abstract.cfm?uri=ol-40-10-2181 [ original @ optics letters website ] + + .
And you have already written the first three sentences of the full article: images obtained through a turbulent medium ( like the atmosphere ) suffer from serious quality degradation .
there are several methods developed to alleviate this problem .
one of them is the adaptive optics @xcite , which is a method commonly used in astronomy , microscopy and surveillance . in this technique ,.
Please generate the next two sentences of the article | a high - speed camera monitors continuously the shape of the wave front and the closed - loop system compensates for the wave distortions by deforming a special mirror in the optical path @xcite .
however , this approach is very complex , expensive and requires sophisticated equipment ( e.g. the deformable mirror or the wavefront sensing devices ) . |
5,609 | Suppose that you have an abstract for a scientific paper: extending the dynamics underlying the factorization calculation of two - body decays , we propose simple selection rules for nonresonant three - body @xmath0 decays .
we predict , for instance , that in the dalitz plot of @xmath1 , practically no events should be found in the corner region of @xmath2 as compared with the corner of @xmath3 .
we also predict that there should be very few three - body decay events containing one soft meson resonance and two energetic mesons or meson resonances .
the selection rules are quite different from the soft - pion theorem , since they apply to different kinematical regions . for @xmath4 ,
the latter predicts that the decay matrix element vanishes in the zero four - momentum limit of @xmath5 instead of @xmath6 . since this marked difference from the soft - pion theorem
is directly related to the issue of short - distance qcd dominance in two - body b decays , experimental test of the selection rules will shed light on strong interaction dynamics of @xmath0 decay . .
And you have already written the first three sentences of the full article: the factorization calculation@xcite has successfully reproduced the decay rate for many two - body channels of @xmath0 decay .
it has been argued@xcite that the factorization should become exact in the large @xmath7-quark mass limit and that the only deviation from the factorization is short - distance corrections of @xmath8 . for some channels of @xmath0 decay
, however , the factorization calculation appears to be in clear disagreement with current measurement@xcite ..
Please generate the next two sentences of the article | theoretically the factorization and the final - state interaction ( fsi ) are closely tied together@xcite .
if the factorization is a good approximation , the fsi phase should be small in general . if the fsi phase turns out to be large in experiment , it is a warning sign against the factorization . |
5,610 | Suppose that you have an abstract for a scientific paper: we introduce _ quantum finite state transducers ( qfst ) _ , and study the class of relations which they compute .
it turns out that they share many features with probabilistic finite state transducers , especially regarding undecidability of emptiness ( at least for low probability of success ) .
however , like their ` little brothers ' , the quantum finite automata , the power of qfst is incomparable to that of their probabilistic counterpart .
this we show by discussing a number of characteristic examples . .
And you have already written the first three sentences of the full article: [ sec : defi ] the issue of this work is to introduce and to study the computational model of quantum finite state transducers .
these can be understood as finite automata with the addition of an output tape which compute a relation between strings , instead of a decision ( which we read as a binary valued function ) .
after the necessary definitions , the relation to quantum finite automata is clarified ( section [ sec : qfa : qfst ] ) , then decidability questions are addressed ( section [ sec : empty ] ) : it is shown that emptiness of the computed relation is undecidable both for quantum and probabilistic transducers ..
Please generate the next two sentences of the article | however , the membership problem for a specific output is decidable .
next , the relation between deterministic and probabilistic transducers is explored ( section [ sec : det : prob ] ) , and in section [ sec : qfst ] quantum and probabilistic transducers are compared . |
5,611 | Suppose that you have an abstract for a scientific paper: we use the recent results on dark matter searches of the 22-string icecube detector to probe the remaining allowed window for strongly interacting dark matter in the mass range 10@xmath0m@xmath110@xmath2 gev .
we calculate the expected signal in the 22-string icecube detector from the annihilation of such particles captured in the sun and compare it to the detected background . as a result
, the remaining allowed region in the mass versus cross section parameter space is ruled out .
we also show the expected sensitivity of the complete icecube detector with 86 strings . .
And you have already written the first three sentences of the full article: the search for dark matter is currently one of the most active fields of research in experimental astroparticle physics .
common candidates are weakly interacting massive particles ( wimps ) , with only weak and gravitational interactions with normal matter , and which encompass a variety of particle types in the mass range from a few tens of gev to a few hundred tev , where the upper limit is based on theoretical arguments to preserve unitarity @xcite . among wimp candidates
are the lightest neutralino arising in the minimal supersymmetric extension of the standard model ( mssm ) , or the lightest kaluza - klein mode in models of universal extra dimensions ( ued ) @xcite ..
Please generate the next two sentences of the article | these candidates are thermal relics from the big bang , and since they are stable , assumed to be able to contribute to the dark matter content in the halos of galaxies . in a different scenario
, it has been shown that super - massive particles can be produced in the early universe and account for dark matter , independently of their interaction strength with normal matter . in order to avoid the mass limit imposed by unitarity constraints |
5,612 | Suppose that you have an abstract for a scientific paper: the superconductor sr@xmath0ruo@xmath1 is widely believed to be a spin triplet system with a chiral order parameter analogous to the a phase of superfluid helium-3 .
the best evidence for this pairing state is that the knight shift or spin susceptibility measured in neutron scattering is constant below t@xmath2 , unlike in a spin - singlet superconductor .
the original knight shift and neutron scattering measurements were performed for magnetic fields aligned in the ruthenate a - b plane .
these would be consistent with a triplet d - vector @xmath3 aligned along the c - axis .
however recently the knight shift for fields along c was also found to be constant below t@xmath2 , which is not expected for this symmetry state . in this paper
we show that while spin - orbit interaction stabilises the c - axis oriented d - vector , it is possible that only a very small external b field may be sufficient to rotate the d - vector into the a - b plane . in this case
the triplet pairing model remains valid .
we discuss characteristics of the transition and the prospects to detect it in thermodynamic quantities .
ruthenate superconductors , pairing symmetry , d - vector rotation 74.20.-z , 74.20.rp , 74.70.pq , 74.25.bt .
And you have already written the first three sentences of the full article: strontium ruthenate is an intriguing low t@xmath2 superconductor @xcite .
it is widely believed to have spin triplet order parameter .
the orbital symmetry of it , however , is still unknown ..
Please generate the next two sentences of the article | knight shift @xcite and spin susceptibility @xcite being constant below @xmath4 point to the chiral state with d - vector @xmath5 .
this state ( called ( a ) in the following ) is also consistent with the @xmath6-sr experiments which show spontaneous time reversal symmetry breaking at @xmath4 @xcite . |
5,613 | Suppose that you have an abstract for a scientific paper: we analyse a two - particle quantum system in @xmath0 with interaction and in presence of a random external potential field with a continuous argument ( an anderson model in a continuous space ) .
our aim is to establish the so - called wegner - type estimates for such a model , assessing the probability that random spectra of hamiltonians in finite volumes intersect with a given set . for the lattice version of the two - particle model ,
a similar result was obtained in @xcite h l p 00 2 ^ 2 2 ^ 2 _ # 1#1 # 1#1 # 1\{#1 } # 1 # 1#2_#1 # 1| # 1 | # 1\{#1 } # 1 \ { # 1 } # 1#2 _#1\ { # 2 } # 1| # 1 | # 1 # 1 # 1@xmath1-s # 1@xmath1-s # 1 # 1#2#3 # 1#2 # 1 .
And you have already written the first three sentences of the full article: this paper is a follow - up of @xcite and establishes wegner - type ( more precisely , wegmer stollmann - type ) bounds for random continuous schrdinger operators .
we focus here on a two - particle interactive anderson model in a continuous space , subject to a random external field with a continuous argument .
the infinite - volume hamiltonian of the model is a schrdinger operator @xmath2 acting on functions @xmath3 : @xmath4 here @xmath5 is the kinetic energy operator : @xmath6 where @xmath7 is the laplacian in variable @xmath8 corresponding to the @xmath9th particle : @xmath10 the randomness in hamiltonian @xmath11 is concentrated in the potential energy function @xmath12 which is written in the form @xmath13 the term @xmath14 represents the ( nonrandom ) interaction potential while the sum @xmath15 $ ] describes the action of an external potential field on the two - particle system ..
Please generate the next two sentences of the article | more precisely , the external potential field is represented by a family of real random variables ( rvs ) @xmath16 , or , in probabilistic terminology , by a real - valued random field with a continuous argument ( or simply ) .
a sample of such a random field is a ( measurable ) function @xmath17 , and its its graph is a ` hypersurface ' in @xmath18 , with a unique point of intersection with any straight line orthogonal to the ` argument space ' @xmath0 . |
5,614 | Suppose that you have an abstract for a scientific paper: the spectral excess theorem for distance - regular graphs states that a regular ( connected ) graph is distance - regular if and only if its spectral - excess equals its average excess .
a bipartite graph @xmath0 is distance - biregular when it is distance - regular around each vertex and the intersection array only depends on the stable set such a vertex belongs to . in this note
we derive a new version of the spectral excess theorem for bipartite distance - biregular graphs . .
And you have already written the first three sentences of the full article: the spectral excess theorem , due to fiol and garriga @xcite , states that a regular ( connected ) graph @xmath0 is distance - regular if and only if its spectral - excess ( a number which can be computed from the spectrum of @xmath0 ) equals its average excess ( the mean of the numbers of vertices at maximum distance from every vertex ) , see van dam @xcite , and fiol , gago and garriga @xcite for short proofs .
recently , some local as well as global approaches to that result have been used to obtain new versions of the theorem for nonregular graphs , and also to study the problem of characterizing those graphs which have the corresponding distance - regularity property ( see , for instance , dalf , van dam , fiol , garriga , and gorissen @xcite ) .
one of these concepts is that of ` pseudo - distance - regularity ' around a vertex , introduced by fiol , garriga , and yebra @xcite , which generalizes the known concept of distance - regularity around a vertex and , in some cases , coincides with that of distance - biregularity , intended for bipartite graphs ..
Please generate the next two sentences of the article | a bipartite graph is distance - biregular when it is distance - regular around each vertex and the intersection array only depends on the stable set such a vertex belongs to ( see delorme @xcite ) . in general
, distance - regular and distance - biregular graphs have found many ` applications ' . |
5,615 | Suppose that you have an abstract for a scientific paper: we study stability of conservative solutions of the cauchy problem for the periodic camassa holm equation @xmath0 with initial data @xmath1 .
in particular , we derive a new lipschitz metric @xmath2 with the property that for two solutions @xmath3 and @xmath4 of the equation we have @xmath5 . the relationship between this metric and usual norms in @xmath6 and @xmath7
is clarified . .
And you have already written the first three sentences of the full article: the ubiquitous camassa holm ( ch ) equation @xcite @xmath8 where @xmath9 is a constant , has been extensively studied due to its many intriguing properties .
the aim of this paper is to construct a metric that renders the flow generated by the camassa
holm equation lipschitz continuous on a function space in the conservative case . to keep the presentation reasonably short , we restrict the discussion to properties relevant for the current study ..
Please generate the next two sentences of the article | more precisely , we consider the initial value problem for with periodic initial data @xmath10 .
since the function @xmath11 satisfies equation with @xmath12 , we can without loss of generality assume that @xmath13 vanishes . for convenience |
5,616 | Suppose that you have an abstract for a scientific paper: this paper deals with theoretical predictions for he burning models in a range of masses covering the so - called red giant branch phase transition . taking as a guideline the observational constraints given by hipparcos parallaxes to the predicted luminosity of models originated from red giant progenitors with he core undergoing electron degeneracy , we compare models by various authors as recently appeared in the literature , disclosing sensitive differences in the predicted luminosity .
the `` solidity '' of these theoretical predictions is investigated by exploring the effects of varying the assumptions about the efficiency of core overshooting or the amount of mass loss , giving quantitative estimates of the related uncertainties .
however , one finds that theoretical predictions concerning the luminosity of the red giant clump in the hipparcos sample is scarcely affected by these mechanisms . *
a comparison among theoretical predictions as recently given by different authors convincingly demonstrates that the different luminosity predictions are the natural results of evolutionary codes with different - but all reasonable- input physics . * in this context observations suggests that stellar models based on the `` most updated '' input physics are possibly overestimating the luminosity of these structures , raising doubts on several current predictions concerning the luminosity of hb stars in galactic globulars . .
And you have already written the first three sentences of the full article: hipparcos parallaxes for clumping he burning red giants in the solar neighborhood have recently raised a large interest in the astronomical community , providing a new valuable ( though controversial ) tool to approach the problem of magellanic clouds distances ( see , e.g. , udalski et al .
1998 , stanek , zaristski et al .
1998 , cole 1998 , girardi et al . 1998 ) . however , on theoretical grounds one has to notice that these parallaxes provide us for the first time with direct observational evidences for the luminosity of he burning stars whose red giant progenitors experienced electron degeneracy in the stellar core . therefore providing a relevant test for the rather sophisticated input physics supporting current theoretical predictions concerning galactic globulars and , more in particular , concerning some relevant issues as the luminosity of rr lyrae stars and the ages of halo stellar clusters ..
Please generate the next two sentences of the article | such a test appears now of particular interest because of the growing rumor about a possible overluminosity of theoretical models for he burning stars with degenerated progenitors . as a matter of example , pols et al .
( 1998 ) found that the he clump luminosity in the open cluster m67 appears 0.2 - 0.3 mag fainter than predicted on the basis of their evolutionary computations . |
5,617 | Suppose that you have an abstract for a scientific paper: we show that nanosphere dispersed liquid crystal ( ndlc ) metamaterial can be characterized in near ir spectral region as an indefinite medium whose real parts of effective ordinary and extraordinary permittivities are opposite in signs . based on this fact we design a novel electrooptic effect : external electric field driven switch between normal refraction , negative refraction and reflection of tm incident electromagnetic wave from the boundary vacuum / ndlc . a detailed analysis of its functionality is given based on effective medium theory combined with a study of negative refraction in anisotropic metamaterials , and finite elements simulations . .
And you have already written the first three sentences of the full article: novel metamaterials @xcite , in particular those for which the spatial distribution of optical parameters can be specifically tailor made , have proven to be a viable route to realize various linear , nonlinear or tunable optical properties and processes . amongst them , the hyperbolic metamaterials ( hm ) - indefinite metamaterials , for which the permittivity and permeability tensors are negative along only certain of the principal axes of the metamaterial @xcite - attract interest because of possibilities of optical steering and manipulation . closely related are optical effects like negative refraction @xcite , hyperlensing @xcite , cancellation of reflection and transmission @xcite .
optical devices based on indefinite media are designed , like , e.g. , polarization beam splitters @xcite , angular filters @xcite , optical transmission modulator @xcite .
theoretical approaches were worked out to handle the negative refraction in anisotropic indefinite media have also been presented @xcite ..
Please generate the next two sentences of the article | tunability and simple production become important requirements .
one of the few metamaterials which offer tunability @xcite , is nematic liquid crystal ( nlc ) doped with coated core - shell spheres ( ndlc ) @xcite . |
5,618 | Suppose that you have an abstract for a scientific paper: a polynomial invariant of virtual links , arising from an invariant of links in thickened surfaces introduced by jaeger , kauffman , and saleur , is defined and its properties are investigated .
examples are given that the invariant can detect chirality and even non - invertibility of virtual knots and links .
furthermore , it is shown that the polynomial satisfies a conway - type skein relation in contrast to the alexander polynomial derived from the virtual link group .
+ _ keywords : _ virtual knot theory , conway skein relation , alexander invariants + _ ams classification : _ 57m25 * on alexander - conway polynomials + for virtual knots and links * + jrg sawollek + december 21 , 1999 ( revised : january 3 , 2001 ) .
And you have already written the first three sentences of the full article: in @xcite kauffman defines an extension of classical knot diagrams to virtual knot diagrams , motivated by gauss codes on the one hand and knots in thickened surfaces on the other hand .
several classical knot invariants can be generalized to the virtual theory without much effort , e.g. , the knot group and derived invariants such as the alexander polynomial , the bracket and jones polynomials , and vassiliev invariants ( which can be introduced in different ways , see @xcite and @xcite ) . the present paper deals with a polynomial invariant that is derived from an invariant of links in thickened surfaces introduced by jaeger , kauffman , and saleur in @xcite .
the determinant formulation of the polynomial immediately generalizes to virtual link diagrams ..
Please generate the next two sentences of the article | it is a laurent polynomial in two variables with integral coefficients that vanishes on the class of classical link diagrams but gives non - trivial information for diagrams that represent non - classical virtual links .
especially , examples can be given that the invariant is sensitive with respect to changes of orientation of a virtual knot . |
5,619 | Suppose that you have an abstract for a scientific paper: all far ultraviolet observations of hd209458 tend to support a scenario in which the inflated hydrogen atmosphere of its planetary companion strongly absorbs the stellar flux during transit . however , it was not clear how the transit absorption depends on the selected wavelength range in the stellar line profile , nor how the atomic hydrogen cloud was distributed spatially around hd209458b . here
we report a sensitivity study of observed time and spectral variations of the stellar flux .
in particular , the sensitivity of the absorption depth during transit to the assumed spectral range in the stellar line profile is shown to be very weak , leading to a transit depth in the range @xmath0 for all possible wavelength ranges , and thereby confirming our initially - reported absorption rate .
taking the ratio of the line profile during transit to the unperturbed line profile , we also show that the spectral signature of the absorption by the exoplanetary hydrogen nebula is symmetric and typical of a lorentzian , optically thick medium .
our results question the adequacy of models that require a huge absorption and/or a strong asymmetry between the blue and red side of the absorption line during transit as no such features could be detected in the hst fuv absorption profile . finally , we show that standard atmospheric models of hd209458b provide a good fit to the observed absorption profile during transit .
other hybrid models assuming a standard model with a thin layer of superthermal hydrogen on top remain possible . .
And you have already written the first three sentences of the full article: just like our sun , the line profile of hd209458 shows a double - horn emission with the distinguishing feature of intervening interstellar gas strongly absorbing the line core . from the signal left at the earth s orbit ,
@xcite ( hereafter ) initially claimed that hst / stis medium resolution observations of hd209458 are showing a strong absorption of 15% during transit and that a large asymmetry appears on the blue side of the absorption profile .
those authors used the 15% drop - off of the stellar signal during transit as an indication of the presence of a hydrogen cloud that extends beyond the roche lobe of the planet ..
Please generate the next two sentences of the article | the next step for was to use the asymmetry claimed in the blue side of the line during transit as an indication that the evaporated gas is accelerated by the radiation pressure from the star , an acceleration that results into the build - up of a cometary shape of the nebulosity that escapes from the planet away from the star .
+ later on , @xcite rejected the acceleration process by radiation pressure , arguing that neutrals will not have the time to be accelerated by the radiation pressure before they get ionized . |
5,620 | Suppose that you have an abstract for a scientific paper: the ba ii d@xmath0 line at 4554 is a good example , where the @xmath1-state interference effects due to the odd isotopes produce polarization profiles , which are very different from those of the even isotopes that do not exhibit @xmath1-state interference .
it is therefore necessary to account for the contributions from the different isotopes to understand the observed linear polarization profiles of this line . in this paper
we present radiative transfer modeling with partial frequency redistribution ( prd ) , which is shown to be essential to model this line .
this is because complete frequency redistribution ( crd ) can not reproduce the observed wing polarization .
we present the observed and computed @xmath2 profiles at different limb distances .
the theoretical profiles strongly depend on limb distance ( @xmath3 ) and the model atmosphere which fits the limb observations fails at other @xmath3 positions .
[ authorguide ] .
And you have already written the first three sentences of the full article: the interpretation of the second solar spectrum requires taking into account a number of physical processes that are not relevant for the intensity spectrum .
some of the lines observed in the second solar spectrum , like the nai d@xmath4 and d@xmath0 , cr i triplet at 5206 , baii d@xmath4 and d@xmath0 , mg ii h and k , and caii h and k , are affected by quantum interference between states of different total angular momentum ( @xmath5 or @xmath1 states ) .
the importance of quantum interference was first demonstrated both observationally and theoretically by ..
Please generate the next two sentences of the article | an approximate theoretical approach for treating @xmath5-state interference with partial frequency redistribution ( prd ) was proposed by @xcite .
this theory was then applied to model the linear polarization profiles of the cr i triplet at 5204 - 5208 by . |
5,621 | Suppose that you have an abstract for a scientific paper: we show that planet formation via both gravitational collapse and core accretion is unlikely to occur in equal mass binary systems with moderate ( @xmath0 au ) semi - major axes .
internal thermal energy generation in the disks is sufficient to heat the gas everywhere so that spiral structures quickly decay rather than grow or fragment . this same heating will inhibit dust coagulation because the temperatures rise above the vaporization temperatures of many volatile materials .
we consider other processes not included in the model and conclude that our temperatures are conservatively estimated ( low ) , i.e. planet formation is less likely in real systems than in the model . .
And you have already written the first three sentences of the full article: both indirect evidence @xcite and later direct imaging @xcite , have shown that disks are quite common in young stellar systems .
these disks are commonly thought @xcite to be sites for planet or brown dwarf formation . a large fraction of stars are formed in binary systems @xcite and in the same star formation regions as single stars .
theory suggests that the most likely mechanisms responsible for forming jovian mass planets or low mass brown dwarfs are either gravitational collapse of large scale spiral structure or coagulation of small solid grains followed by later accretion of additional gas ( ` core accretion ' ) in the disks of forming stellar systems ..
Please generate the next two sentences of the article | evaluating the effectiveness of these mechanisms is important for understanding the origin of our own solar system as well as planetary systems in other mature single or multiple systems .
the l1551 irs 5 system serves as a useful observational testbed for comparison to theoretical modeling because of its relative youth ( @xmath1 yr , * ? ? ? |
5,622 | Suppose that you have an abstract for a scientific paper: a model based on first - degree family relations network is used to describe the wealth distribution in societies .
the network structure is not a - priori introduced in the model , it is generated in parallel with the wealth values through simple and realistic dynamical rules .
the model has two main parameters , governing the wealth exchange in the network .
choosing their values realistically , leads to wealth distributions in good agreement with measured data .
the cumulative wealth distribution function has an exponential behavior in the low and medium wealth limit , and shows the pareto - like power - law tail for the upper @xmath0 of the society .
the obtained pareto indexes are in good agreement with the measured ones .
the generated family networks also converges to a statistically stable topology with a simple poissonian degree distribution . on this family - network
many interesting correlations are studied , and the main factors leading to wealth - diversification and the formation of the pareto law are identified . , , wealth distribution , random networks , econophysics , pareto s law 89.75-k , 89.65.gh , 89.75.hc , 87.23.ge .
And you have already written the first three sentences of the full article: since the seminal work by vilfredo pareto@xcite , it is known that the wealth distribution in capitalist economies shows a very peculiar and somehow universal functional form . in the range of low income
, the cumulative distribution of wealth ( the probability that the wealth of an individual is greater than a given value ) may be fitted by an exponential or log - normal decreasing function , while in the region containing the richest part of the population , generally less than the @xmath0 of the individuals , this distribution is well characterized by a power - law ( see for example @xcite for a review ) .
this empirical behavior has been confirmed by a number of recent studies on the economy of several corners of the world ..
Please generate the next two sentences of the article | the available data is coming from so far apart as australia @xcite , japan @xcite , the us @xcite , continental europe @xcite or the uk @xcite .
the data is also spanning so long in time as ancient egypt @xcite , renaissance europe @xcite or the @xmath1 century japan@xcite . |
5,623 | Suppose that you have an abstract for a scientific paper: cataclysmic variables ( cvs ) are interacting binary systems where a cool , rapidly rotating secondary star passes material to a white dwarf . if this mass loss is to continue then there must be continuous angular momentum loss from the system .
by analogy with the sun and other cool stars , it has been assumed that magnetic braking is responsible , angular momentum being carried away by an ionised wind from the secondary star , threading a dynamo - generated magnetic field .
we have discovered tio absorption in the spectrum of ss cyg , whose secondary star should be too hot to show such features .
the most likely explanation of its presence is cool star spots caused by the strong ( 0.1 t ) fields required by the magnetic braking theories . .
And you have already written the first three sentences of the full article: cool stars with a spectral type later than f5 ( cooler than about 6500k ) have convective outer layers , which when coupled with rotation , create a dynamo that amplifies magnetic fields and brings them to the stellar surface .
radial magnetic field lines trap the stellar wind , forcing it to co - rotate with the star out to large radii and removing angular momentum from the star .
@xcite first applied such a model to the solar angular momentum loss , and variants of their model can successfully explain the observed rotational spin - down of cool stars in open clusters of increasing age @xcite ..
Please generate the next two sentences of the article | low - mass secondary stars in cataclysmic variables ( cvs ) should exhibit strong ( 0.1 - 0.3 t ) magnetic fields since they have deep convection zones and are rapidly rotating as a result of being tidally locked with their companion .
( tidal interaction ensures that the secondary star is brought into synchronous rotation with the orbit . ) |
5,624 | Suppose that you have an abstract for a scientific paper: high - gain nonlinear observers occur in the nonlinear automatic control theory and are in standard usage in chemical engineering processes .
we apply such a type of analysis in the context of a very simple one - gene regulation circuit . in general
, an observer combines an analytical differential - equation - based model with partial measurement of the system in order to estimate the non - measured state variables .
we use one of the simplest observers , that of gauthier et al . , which is a copy of the original system plus a correction term which is easy to calculate .
for the illustration of this procedure , we employ a biological model , recently adapted from goodwin s old book by de jong , in which one plays with the dynamics of the concentrations of the messenger rna coding for a given protein , the protein itself , and a single metabolite . using the observer instead of the metabolite , it is possible to rebuild the non - measured concentrations of the mrna and the protein . _ keywords : _ high - gain observer ; diffeomorphism ; gene regulation ; gene expression published : physica a 380 ( 1 july 2007 ) 235 - 240 + doi : 10.1016/j.physa.2007.02.105 + arxiv : q - bio/0409036v2 [ q-bio.qm ] .
And you have already written the first three sentences of the full article: according to textbooks , gene expression is a very complicated dynamical process which is regulated at a number of its stages during the synthesis of proteins @xcite . similar to many big cities , with heavy traffic , biological cells host complicated traffic of biochemical signals at all levels . at the nanometer scale ,
clusters of molecules in the form of proteins drive the dynamics of the cellular network that schematically can be divided into four regulated parts : the dna or genes , the transcribed rnas , the set of interacting proteins , and the metabolites .
genes can only affect other genes through specific proteins , as well as through some metabolic pathways that are regulated by proteins themselves ..
Please generate the next two sentences of the article | they act to catalyze the information stored in dna , all the way from the fundamental processes of transcription and translation to the final quantities of produced proteins .
+ for the purpose of modeling , it is essential to generate simple models that help to understand elementary dynamical components of these complex regulatory networks as molecular tools that participate in an important way in the machinery of cellular decisions , that is to say , in the behavior and genetic program of cells . |
5,625 | Suppose that you have an abstract for a scientific paper: we study the shape of @xmath0 hypernuclei in the full ( @xmath1 ) deformation plane , including both axially symmetric and triaxial quadrupole deformations . to this end
, we use the constrained skyrme hartree - fock+bcs method on the three - dimensional cartesian mesh .
the potential energy surface is analyzed for carbon hypernuclei as well as for sd - shell hypernuclei such as @xmath2si and @xmath3 mg .
we show that the potential energy surface in the ( @xmath1 ) plane is similar to each other between the hypernuclei and the corresponding core nuclei , although the addition of @xmath0 hyperon makes the energy surface somewhat softer along the @xmath4 direction . .
And you have already written the first three sentences of the full article: one of the main interests in hypernuclear physics is to investigate how an addition of @xmath0 particle influences the properties of atomic nuclei . due to the absence of pauli s principle between nucleon and @xmath0 particle
, it is believed that a @xmath0 hyperon can be treated as an _ impurity _ to probe deep interior of the nuclear medium . with the presence of hyperon as an impurity , some bulk properties of nuclei such as the shape and collective motions
may be changed @xcite ..
Please generate the next two sentences of the article | indeed , the shrinkage of @xmath5li , with respect to @xmath6li , has been observed experimentally by measuring the b(e2 ) value from the @xmath7 state to the @xmath8 state of @xmath5li @xcite . as the shape of nuclei plays a decisive role in determining their properties such as quadrupole moment and radius ,
mean - field model calculations have been performed in recent years to investigate the change of nuclear shape due to the addition of a @xmath0 hyperon . |
5,626 | Suppose that you have an abstract for a scientific paper: in the supersymmetric grand unified theories ( susy guts ) , gauge bosons associated with the unified gauge group induce proton decay .
we investigate the proton decay rate via the gauge bosons in the susy guts under the two situations ; one is with extra vector - like multiplets , and the other is with heavy sfermions .
it is found that the proton lifetime is significantly reduced in the former case , while in the latter case it is slightly prolonged .
determination of the particle contents and their mass spectrum below the gut scale is important to predict the proton lifetime .
the proton decay searches have started to access to the @xmath0 gev scale .
ipmu12 - 0074 1.35 cm 1.2 cm junji hisano@xmath1 , daiki kobayashi@xmath2 , and natsumi nagata@xmath3 + 0.4 cm _
@xmath2department of physics , nagoya university , nagoya 464 - 8602 , japan _ + _
@xmath4ipmu , todias , university of tokyo , kashiwa 277 - 8568 , japan _ + _ @xmath5department of physics , university of tokyo , tokyo 113 - 0033 , japan _ .
And you have already written the first three sentences of the full article: the grand unified theories ( guts ) , which embed the standard model ( sm ) gauge group into a large single gauge group , are quite attractive , and so a variety of models of the theories are proposed since the earliest work based on the su(5 ) symmetry group was presented by georgi and glashow in 1974 @xcite . among them , the supersymmetric grand unified theories ( susy guts ) are considered to be promising candidates since they realize the gauge coupling unification with great accuracy @xcite as well as solving the hierarchy problem in the guts @xcite . the supersymmetric version of the georgi - glashow su(5 ) gut , which is the simplest among the susy guts , is called the minimal susy su(5 ) gut @xcite .
one of the most distinctive features which guts predict is the existence of baryon - number violating interactions , such as proton decay . in the susy guts with @xmath6 parity , for example ,
proton decay is induced by two different processes : the colored - higgs and the @xmath7-boson exchanging processes ..
Please generate the next two sentences of the article | the colored higgs triplets are introduced for the higgs doublets in the minimal supersymmetric standard model ( mssm ) to be incorporated into the su(5 ) multiplets
. the colored - higgs exchange yields baryon - number violating dimension - five operators , which give rise to the dominant contribution to proton decay in the minimal susy su(5 ) guts @xcite . |
5,627 | Suppose that you have an abstract for a scientific paper: we present a new three - dimensional radiative transfer ( rt ) code , ` radamesh ` , based on a ray - tracing , photon - conserving and adaptive ( in space and time ) scheme . `
radamesh ` uses a novel monte carlo approach to sample the radiation field within the computational domain on a `` cell - by - cell '' basis .
thanks to this algorithm , the computational efforts are now focused where actually needed , i.e. within the ionization - fronts ( i - fronts ) .
this results in an increased accuracy level and , at the same time , a huge gain in computational speed with respect to a `` classical '' monte carlo rt , especially when combined with an adaptive mesh refinement ( amr ) scheme . among several new features , ` radamesh ` is able to adaptively refine the computational mesh in correspondence of the i - fronts , allowing to fully resolve them within large , cosmological boxes . we follow the propagation of ionizing radiation from an arbitrary number of sources and from the recombination radiation produced by h and he . the chemical state of six species ( hi , hii , hei , heii , heiii , e ) and gas temperatures are computed with a time - dependent , non - equilibrium chemistry solver .
we present several validating tests of the code , including the standard tests from the rt code comparison project and a new set of tests aimed at substantiating the new characteristics of ` radamesh ` . using our amr scheme ,
we show that properly resolving the i - front of a bright quasar during reionization produces a large increase of the predicted gas temperature within the whole hii region .
also , we discuss how h and he recombination radiation is able to substantially change the ionization state of both species ( for the classical strmgren sphere test ) with respect to the widely used `` on - the - spot '' approximation .
[ firstpage ] radiative transfer - methods : numerical - hii regions - intergalactic medium - diffuse radiation - cosmology : theory .
And you have already written the first three sentences of the full article: the interaction between matter and radiation is one of the fundamental mechanisms shaping the distribution of the baryonic component in the universe , from stellar to cosmological scales .
this process often couples wildly different scales and the large dynamical range makes accurate modelling difficult .
a notable example is given by the reionization of cosmic hydrogen at redshift @xmath0 ( for a review , see , e.g. , meiksin 2009 ) . during this epoch , the hii regions generated by the first ionizing sources expand to intergalactic scales and overlap , leaving most of the universe highly ionized and re - heated by several thousand kelvin degrees ..
Please generate the next two sentences of the article | the brightest , high - redshift quasars , may have produced even larger hii regions before the end of reionization , with linear sizes extending up to a hundred comoving mpc . nonetheless , most of the evolution in the gas temperature and ionization state still happened on much smaller scales , i.e. within the ionization - fronts , whose sizes are comparable to the local photon mean - free - path just outside the hii regions , about three orders of magnitude smaller than the hii regions themselves for gas at mean cosmic density . even without considering such an extreme case in dynamical range , the numerical solution of the full radiative transfer equations still represents a big computational challenge .
this is mostly due to two factors . |
5,628 | Suppose that you have an abstract for a scientific paper: i briefly discuss effective lagrangians for strong interactions while concentrating on two specific lagrangians for qcd at large matter density .
i then introduce spectral duality in qcd a la montonen and olive .
the latter is already present in qcd in the hadronic phase .
however it becomes transparent at large chemical potential .
finally i show the relevance of having exact non perturbative constraints such as thooft anomaly conditions at zero and nonzero quark chemical potential on the possible phases of strongly interacting matter .
an important outcome is that for three massless quarks at any chemical potential the only non trivial solution of the constraints is chiral symmetry breaking .
this also shows that for three massless flavors at large quark chemical potential cfl is the ground state . .
And you have already written the first three sentences of the full article: in the non perturbative regime of strongly interacting theories effective lagrangians play a dominant role since they efficiently describe the non perturbative dynamics in terms of the relevant degrees of freedom .
symmetries , anomalous and exact , are used to constrain the effective lagrangians .
an important point is that the effective lagrangian approach is applicable to any region of the qcd or qcd - like phase diagram whenever the relevant degrees of freedom and the associated symmetries are defined . at zero temperature and quark chemical potential the simplest effective lagrangian describing a relevant part of the nonperturbative physics of the yang - mills ( ym ).
Please generate the next two sentences of the article | theory is the glueball lagrangian whose potential is : @xmath0 \ . \end{aligned}\ ] ] the latter is constrained using trace anomaly and @xmath1 $ ] with @xmath2 the gluon field stress tensor .
it describes the vacuum of a generic yang - mills theory . |
5,629 | Suppose that you have an abstract for a scientific paper: linked cluster expansions are generalized from an infinite to a finite volume on a @xmath0-dimensional hypercubic lattice .
they are performed to 20th order in the expansion parameter to investigate the phase structure of scalar @xmath1 models for the cases of @xmath2 and @xmath3 in 3 dimensions . in particular
we propose a new criterion to distinguish first from second order transitions via the volume dependence of response functions for couplings close to but not at the critical value .
the criterion is applicable to monte carlo simulations as well .
here it is used to localize the tricritical line in a @xmath4 theory .
we indicate further applications to the electroweak transition . .
And you have already written the first three sentences of the full article: convergent expansions such as linked cluster , hopping parameter or high temperature expansions provide an analytic alternative to monte carlo simulations .
originally they have been developed in the infinite volume , meanwhile they have been extended to finite volumes as well @xcite .
in contrast to generic perturbation theory , hopping parameter expansions ( hpes ) are convergent expansions about completely disordered lattice systems ..
Please generate the next two sentences of the article | the expansion parameter @xmath5 is the coefficient of the ( pair ) interaction term .
since we calculate free energies and connected correlations in the hopping parameter expansion , we generate linked cluster expansions ( lces ) . |
5,630 | Suppose that you have an abstract for a scientific paper: we present milliarsecond - resolution maps of the sio maser emission @xmath0=1 j=21 ( 3 mm ) in the bipolar post - agb nebula oh231.8 + 4.2 , and compare them with our previous observations of the @xmath0=2 j=10 line ( 7 mm ) .
our observations show that the sio masers arise in several bright spots forming a structure elongated in a direction perpendicular to the symmetry axis of the nebula .
this , and the complex velocity gradient observed , is consistent with the presence of an equatorial torus in rotation and with an infall of material towards the star .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: planetary and proto - planetary nebulae ( pne , ppne ) present conspicuous departures from spherical symmetry , including e.g. multiple lobes and jets . to explain their evolution from spherical agb envelopes ,
several models have postulated the presence of dense rings or disks close to the central post - agb stars as the agents of the mechanical collimation of the stellar wind .
existing observations reveal the presence of central disks in several ppne , but their limited spatial resolution can not unveil the very inner regions of the disks that are relevant for the processes mentioned above ..
Please generate the next two sentences of the article | our first vlba observations of sio masers in oh231.8 + 4.2 , carried out at 7 mm ( @xmath0=2 , @xmath1=10 ) in april 2000 , revealed for the first time the structure and kinematics of the close stellar environment in a ppn ( sanchez contreras et al . , 2002 ) .
the sio maser emission arises in several compact , bright spots forming a structure elongated in the direction perpendicular to the symmetry axis of the nebula . |
5,631 | Suppose that you have an abstract for a scientific paper: in this paper we consider the problem of detecting statistically significant sequential patterns in multi - neuronal spike trains .
these patterns are characterized by an ordered sequences of spikes from different neurons with specific delays between spikes .
we have previously proposed a datamining scheme @xcite to efficiently discover such patterns which are frequent in the sense that the count of non - overlapping occurrences of the pattern in the data stream is above a threshold . here
we propose a method to determine the statistical significance of these repeating patterns and to set the thresholds automatically .
the novelty of our approach is that we use a compound null hypothesis that includes not only models of independent neurons but also models where neurons have weak dependencies .
the strength of interaction among the neurons is represented in terms of certain pair - wise conditional probabilities .
we specify our null hypothesis by putting an upper bound on all such conditional probabilities .
we construct a probabilistic model that captures the counting process and use this to calculate the mean and variance of the count for any pattern . using this
we derive a test of significance for rejecting such a null hypothesis .
this also allows us to rank - order different significant patterns .
we illustrate the effectiveness of our approach using spike trains generated from a non - homogeneous poisson model with embedded dependencies . .
And you have already written the first three sentences of the full article: analyzing spike trains from hundreds of neurons to find significant temporal patterns is an important current research problem @xcite . by using experimental techniques such as micro electrode arrays or imaging of neural currents ,
spike data can be recorded simultaneously from many neurons @xcite .
such multi - neuronal spike train data can now be routinely gathered _ in vitro _ from neural cultures or _ in vivo _ from brain slices , awake behaving animals and even humans . such data would be a mixture of stochastic spiking activities of individual neurons as well as that due to correlated activity of groups of neurons due to interconnections , possibly triggered by external inputs . automatically discovering patterns ( regularities ) in these spike trains can lead to better understanding of how interconnected neurons act in a coordinated manner to generate specific functions ..
Please generate the next two sentences of the article | there has been much interest in techniques for analyzing the spike data so as to infer functional connectivity or the functional relationships within the system that produced the spikes @xcite .
in addition to contributing towards our knowledge of brain function , understanding of functional relations embedded in spike trains leads to many applications , e.g. , better brain - machine interfaces . |
5,632 | Suppose that you have an abstract for a scientific paper: the role of carbon stars in the build - up of chemical elements in galaxies is discussed on the basis of stellar evolution calculations and estimated stellar yields , abundance analyses of agb stars , galactic - evolution models and abundance trends among solar - type disk stars .
we conclude that the agb stars in general , and carbon stars in particular , probably are main contributors of @xmath0-elements , that their contributions of flourine and carbon are quite significant , and that possibly their contributions of lithium , @xmath1c and @xmath2ne are of some importance
. also contributions of n , na and al are discussed .
the major uncertainties that characterize almost any statement concerning these issues are underlined . .
And you have already written the first three sentences of the full article: any discussion of the role of carbon stars ( c stars ) in the chemical evolution of galaxies raises a number of important questions such as : for which metal abundances and initial stellar masses do stars become c stars ? how much mass does a star lose during its c star phase ?
what are the elemental compositions of these ejecta ?
c stars are brilliant and show easily recognizable spectral characteristics ..
Please generate the next two sentences of the article | thus , their occurrence and frequency in different galaxies may be interpreted in terms of the properties ( metallicity and age ) of the stellar populations , if we know which stars become c stars .
current answers to this question are , however , not very precise , although stars with masses somewhere in the interval 1.2 to 4m@xmath3 may be a realistic answer . |
5,633 | Suppose that you have an abstract for a scientific paper: to solve the many - boson schrdinger equation we utilize the multiconfigurational time - dependent hartree method for bosons ( mctdhb ) . to be able to attack larger systems and/or to propagate the solution for longer times , we implement a parallel version of the mctdhb method thereby realizing the recently proposed [ streltsov _ et al .
_ arxiv:0910.2577v1 ] novel idea how to construct efficiently the result of the action of the hamiltonian on a bosonic state vector .
we study the real - space dynamics of repulsive bosonic systems made of @xmath0 , 51 and 3003 bosons in triple - well periodic potentials .
the ground state of this system is three - fold fragmented . by suddenly strongly distorting the trap potential , the system performs complex many - body quantum dynamics . at long times
it reveals a tendency to an oscillatory behavior around a threefold fragmented state .
these oscillations are strongly suppressed and damped by quantum depletions . in spite of the richness of the observed dynamics , the three time - adaptive orbitals of mctdhb(@xmath1 ) are capable to describe the many - boson quantum dynamics of the system for short and intermediate times . for longer times , however , more self - consistent time - adaptive orbitals are needed to correctly describe the non - equilibrium many - body physics .
the convergence of the mctdhb(@xmath2 ) method with the number @xmath2 of self - consistent time - dependent orbitals used is demonstrated . .
And you have already written the first three sentences of the full article: quantum dynamics of bosonic systems @xcite is a highly active branch of modern physics .
it plays a crucial role in experiments with trapped ultra cold atomic or molecular clouds especially when external trap potentials are varied in time .
theoretical predictions on the dynamics of quantum systems in these cases are highly desirable ..
Please generate the next two sentences of the article | quantum dynamics is usually governed by the time - dependent schrdinger equation @xcite . to solve it means to define an initial condition , i.e.
, initial wave packet , and to find the evolution of this initial state in time , i.e. , to propagate it . in this work |
5,634 | Suppose that you have an abstract for a scientific paper: particle yields in heavy ion collisions show an overwhelming evidence for chemical or relative chemical equilibrium at all beam energies . the rapidity dependence of the thermal parameters @xmath0 and @xmath1 can now be determined over a wide range of rapidities and
show a systematic behavior towards an increase in @xmath1 away from mid - rapidity . .
And you have already written the first three sentences of the full article: over the past decade , the analysis of particle multiplicities in heavy ion collions has shown overwhelming evidence for chemical equilibrium in the final state except for particles carrying strangeness which are mildly suppressed ; however , their relative yields fulfill statistical equilibrium . a summary as of 2006 , combining the results from many different groups @xcite , is shown in fig . [ eovern ] . us determined from heavy ion collisions at different beam energies .
the lower ags points are based on a preliminary analysis of @xmath2 data.,width=226 ] except for particle multiplicities at rhic energies , all data in fig .
[ eovern ] use integrated particle yields , the very systematic change of thermal parameters over the full range of beam energies is one of the most impressive features of relativistic ion collisions to date ..
Please generate the next two sentences of the article | it is now possible to use the thermal model to make solid predictions for particle multiplicities at lhc energies @xcite and to determine which beam energy will lead to the highest baryon density at freeze - out @xcite . with chemical equilibrium for integrated yields
thus firmly established , we focus on other properties , in particular , since the rapidity distributions of identified particles is now becoming available also at rhic energies @xcite , it is now possible to determine the rapidity dependence of thermal parameters . |
5,635 | Suppose that you have an abstract for a scientific paper: in the study of galaxy integrated light , if photometric indicators could extract age and metallicity information of high enough quality , photometry might be vastly more efficient than spectroscopy for the same astrophysical goals . toward this end
, we search three photometric systems : david dunlap observatory ( ddo ) , beijing - arizona - taiwan - connecticut ( batc ) , and strmgren systems for their ability to disentangle age and abundance effects .
only the strmgren @xmath0 $ ] vs. @xmath1 $ ] plot shows moderate age - metallicity disentanglement .
we also add to the discussion of optical to near - infrared johnson - cousins broad band colours , finding a great decrease in age sensitivity when updated isochrones are used .
[ firstpage ] galaxies : abundances galaxies : evolution galaxies : general galaxies : photometry galaxies : stellar content .
And you have already written the first three sentences of the full article: since the concept of stellar populations was invented @xcite , stellar population synthesis ( sps ) has been proven to be a useful tool for revealing clues about galaxy formation @xcite .
research on several crucial factors of stellar modelling , like convection , opacity , heavy - element mixing , helium content , and mass loss @xcite , resulted in increasingly accurate sps models @xcite . in this scheme ,
estimation of single burst equivalent age and metallicity , was accomplished by comparing integrated light of observed galaxy with that of sps models . however , most of the colours and absorption feature strength appear identical if the changes of age and metallicity satisfy @xmath2 ..
Please generate the next two sentences of the article | this so - called age - metallicity degeneracy @xcite blocks the way to estimating galaxy accurate ages from optical broad band colours . at spectroscopically narrow bands , however , several age sensitive or metallicity sensitive lick indices
@xcite , taken in pairs , are effective at breaking this degeneracy . |
5,636 | Suppose that you have an abstract for a scientific paper: sturm - liouville oscillation theory for periodic jacobi operators with matrix entries is discussed and illustrated .
the proof simplifies and clarifies the use of intersection theory of bott , maslov and conley - zehnder .
it is shown that the eigenvalue problem for linear hamiltonian systems can be dealt with by the same approach . .
And you have already written the first three sentences of the full article: let @xmath0 and @xmath1 be integers and @xmath2 or @xmath3 .
a jacobi matrix with matrix entries is an operator of the form @xmath4 where @xmath5 are selfadjoint complex @xmath6 matrices and @xmath7 are invertible complex @xmath6 matrices . if @xmath3 , then the jacobi matrix is said to have dirichlet boundary conditions ( on the left and right edge ) and we denote it by @xmath8 . if @xmath9 for @xmath10 , the jacobi matrix is called periodic and will be denoted by @xmath11 .
both @xmath11 and @xmath8 are selfadjoint operators on the hilbert space @xmath12 ..
Please generate the next two sentences of the article | matrices of type appear in a number of applications . in an example coming from solid state physics
, @xmath13 is the finite volume approximation of a @xmath14-dimensional tight - binding hopping model with periodic boundary conditions on a discretized cube @xmath15 . |
5,637 | Suppose that you have an abstract for a scientific paper: excited states of the hydrogen molecule subject to a homogeneous magnetic field are investigated for the parallel configuration in the complete regime of field strengths @xmath0 . up
to seven excitations are studied for gerade as well as ungerade spin singlet states of @xmath1 symmetry with a high accuracy .
the evolution of the potential energy curves for the individual states with increasing field strength as well as the overall behaviour of the spectrum are discussed in detail .
a variety of phenomena like for example the sequence of changes for the dissociation channels of excited states and the resulting formation of outer wells are encountered .
possible applications of the obtained data to the analysis of magnetic white dwarfs are outlined . .
And you have already written the first three sentences of the full article: matter which is exposed to strong external magnetic fields changes its basic properties and structure and leads to a variety of new phenomena . as a result strong fields are of importance in different branches of physics like atomic , molecular or solid state physics . for atomic and molecular systems
there are two prominent possibilities to encounter the strong field regime : highly excited rydberg states in the laboratory and atoms and molecules in the atmospheres of magnetized white dwarfs ( see refs.@xcite for a compilation of the subject ) . from a theorists point of view particle systems in strong fields
pose a hard problem due to several competing interactions ( coulomb attraction and repulsion , para- and diamagnetic interactions ) . of particular interest.
Please generate the next two sentences of the article | , but most complicated to investigate , is hereby the so - called intermediate regime which is characterized by comparable magnetic and coulomb binding forces .
focusing on the low - lying states of atoms and molecules we envisage this regime for those magnetic white dwarfs which possess field strengths in the regime @xmath2 . |
5,638 | Suppose that you have an abstract for a scientific paper: in this paper we present a method of scintillation detector energy calibration using the gamma - rays .
the technique is based on the compton scattering of gamma - rays in a scintillation detector and subsequent photoelectric absorption of the scattered photon in the ge - detector .
the novelty of this method is that the source of gamma rays , the germanium and scintillation detectors are immediately arranged adjacent to each other .
the method presents an effective solution for the detectors consisting of a low atomic number materials , when the ratio between compton effect and photoelectric absorption is large and the mean path of gamma - rays is comparable to the size of the detector .
the technique can be used for the precision measurements of the scintillator light yield dependence on the electron energy .
scintillator and semiconductor detectors , energy scale calibration .
And you have already written the first three sentences of the full article: a wide range of detectors is difficult to calibrate using gamma or x - rays , because of the absence of full absorption peaks in the spectrum .
in particular , it includes the detectors with spatial dimensions that are relatively small compared to the mean path of calibration source gamma rays , and also the ones which consist of a material with a low atomic number . as a result , the probability of the photoelectric effect is small compared to the probability of the compton scattering , and a small detector dimensions make it impossible to obtain a full absorption peak which could appear due to the multiple scattering .
the calibration by using the edges of the compton scattering has a significantly lower accuracy ..
Please generate the next two sentences of the article | common examples include widespread plastic and liquid hydrocarbon scintillators @xmath0 or semiconductor detectors of a large volume based on silicon .
for example , the compton scattering cross - section of gamma rays at 0.1 ( 1.0 ) mev on carbon is @xmath1 = 2.9 ( 1.3 ) barn / atom , and the photoelectric effect cross - section is lower by two orders of magnitude @xmath2 = 0.021 @xmath3 barns / atom . |
5,639 | Suppose that you have an abstract for a scientific paper: we give a noncommutative version of the complex projective space @xmath0 and show that scalar qft on this space is free of uv divergencies .
the tools necessary to investigate quantum fields on this fuzzy @xmath0 are developed and several possibilities to introduce spinors and dirac operators are discussed .
h. grosse@xmath1 , a. strohmaier@xmath2 + @xmath3institute for theoretical physics , university of vienna , boltzmanngasse 5 , a-1090 vienna , austria + e - mail : [email protected] + @xmath2institute for theoretical physics , tu- graz , petersgasse 16 , a-8010 graz , austria + e - mail : [email protected] * keywords : * regularization , noncommutative geometry , geometric quantization , @xmath0 .
And you have already written the first three sentences of the full article: recently methods of noncommutative geometry ( @xcite ) were used to introduce a covariant regularization procedure for quantum fields on the 2 sphere ( @xcite ) .
there is hope that with these methods there will be a nonperturbative understanding of quantum effects . for a treatment of the chiral anomaly in the schwinger model
see @xcite ..
Please generate the next two sentences of the article | the idea is to approximate the algebra of functions on the space by matrix algebras and to encode the geometrical information of the space in these algebras . in this way it becomes possible to construct models of qft on the virtual spaces ,
the matrix algebras are thought to be functions on . since the theory has only finite degrees of freedom the problems one usually deals with in qft are absent . for examples of these matrix geometries |
5,640 | Suppose that you have an abstract for a scientific paper: we implement novel numerical models of agn feedback in the sph code gadget-3 , where the energy from a supermassive black hole ( bh ) is coupled to the surrounding gas in the _ kinetic _ form .
gas particles lying inside a bi - conical volume around the bh are imparted a one - time velocity ( @xmath0 km / s ) increment .
we perform hydrodynamical simulations of isolated cluster ( total mass @xmath1 ) , which is initially evolved to form a dense cool core , having central @xmath2 k. a bh resides at the cluster center , and ejects energy .
the feedback - driven fast wind undergoes shock with the slower - moving gas , which causes the imparted kinetic energy to be thermalized .
bipolar bubble - like outflows form propagating radially outward to a distance of a few @xmath3 kpc .
the radial profiles of median gas properties are influenced by bh feedback in the inner regions ( @xmath4 kpc ) .
bh kinetic feedback , with a large value of the feedback efficiency , depletes the inner cool gas and reduces the hot gas content , such that the initial cool core of the cluster is heated up within a time @xmath5 gyr , whereby the core median temperature rises to above @xmath6 k , and the central entropy flattens .
our implementation of bh thermal feedback ( using the same efficiency as kinetic ) , within the star - formation model , can not do this heating , where the cool core remains .
the inclusion of cold gas accretion in the simulations produces naturally a duty cycle of the agn with a periodicity of @xmath3 myr .
[ firstpage ] cosmology : theory galaxies : clusters : general galaxies : jets ( galaxies : ) cooling flows black hole physics .
And you have already written the first three sentences of the full article: the enormous amounts of energy emitted by the centers of active galaxies are believed to be from accretion of matter onto supermassive black holes ( smbhs ) lying there ( e.g. , * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | feedback from active galactic nuclei ( agn ) strongly influences the formation and cosmological evolution of structures , whereby the overall properties of a galaxy can be regulated by its central smbh , which also impacts the environment from pc to mpc scales ( e.g. , * ? ? ?
* ; * ? ? ? |
5,641 | Suppose that you have an abstract for a scientific paper: we analyse the present experimental evidence for a complex ckm matrix , even allowing for new physics contributions to @xmath0 , @xmath1 , @xmath2 , @xmath3 , and the @xmath4 piece of @xmath5 and @xmath6 .
we emphasize the crucial rle played by the angle @xmath7 in both providing irrefutable evidence for a 3@xmath83 complex ckm matrix and placing constraints on the size of np contributions .
it is shown that even if one allows for new physics a real ckm matrix is excluded at a 99.92% c.l . ,
and the probability for the phase @xmath7 to be in the interval @xmath9\cup \lbrack 10^{\circ } ; 170^{\circ } ] $ ] is 99.7% .
large value of the phase @xmath10 , e.g. of order @xmath11 , is only possible in models where the unitarity of the @xmath12 cabibbo - kobayashi - maskawa matrix is violated through the introduction of extra @xmath13 quarks .
we study the allowed range for @xmath10 and the effect of a large @xmath10 on various low - energy observables , such as cp asymmetries in @xmath14 meson decays .
we also discuss the correlated effects which would be observable at high energy colliders , like decays @xmath15 , etc .. .
And you have already written the first three sentences of the full article: as is well - known unitarity triangle fits indicate the prominent role of the cabbibo - kobayashi - maskawa ( ckm ) mechanism@xcite in cp violation and flavour physics . the huge amount and the variety of cp collected data allows for a systematic search of physics beyond the standard model ( sm)@xcite@xcite .
a quite general and natural framework to go beyond the sm is : 1 .
allow for new physics in every place except in weak tree - level dominated processes ..
Please generate the next two sentences of the article | 2 . assume @xmath12 unitarity .
this framework is general enough to include practically all models of new physics ( np ) except those that explicitly violate @xmath12 unitarity . |
5,642 | Suppose that you have an abstract for a scientific paper: the problem of guessing a random string is revisited . a close relation between guessing and compression
is first established .
then it is shown that if the sequence of distributions of the information spectrum satisfies the large deviation property with a certain rate function , then the limiting guessing exponent exists and is a scalar multiple of the legendre - fenchel dual of the rate function .
other sufficient conditions related to certain continuity properties of the information spectrum are briefly discussed .
this approach highlights the importance of the information spectrum in determining the limiting guessing exponent .
all known prior results are then re - derived as example applications of our unifying approach .
guessing , length function , source coding , information spectrum , large deviations . .
And you have already written the first three sentences of the full article: let @xmath0 denote @xmath1 letters of a process where each letter is drawn from a finite set @xmath2 with joint probability mass function ( pmf ) @xmath3 .
let @xmath4 be a realization and suppose that we wish to guess this realization by asking questions of the form `` is @xmath5 ? '' , stepping through the elements of @xmath6 until the answer is `` yes '' . we wish to do this using the minimum expected number of guesses .
there are several applications that motivate this problem ..
Please generate the next two sentences of the article | consider cipher systems employed in digital television or dvds to block unauthorized access to special features .
the ciphers used are amenable to such exhaustive guessing attacks and it is of interest to quantify the effort needed by an attacker ( merhav & arikan @xcite ) . |
5,643 | Suppose that you have an abstract for a scientific paper: in this paper we study the inverse dirichlet - to - neumann problem for certain cylindrical electrical networks . we define and study a birational transformation acting on cylindrical electrical networks called the electrical @xmath0-matrix .
we use this transformation to formulate a general conjectural solution to this inverse problem on the cylinder .
this conjecture extends work of curtis , ingerman , and morrow @xcite , and of de verdire , gitler , and vertigan @xcite for circular planar electrical networks .
we show that our conjectural solution holds for certain `` purely cylindrical '' networks . here
we apply the grove combinatorics introduced by kenyon and wilson @xcite . .
And you have already written the first three sentences of the full article: in this paper we consider the simplest of electrical networks , namely those that consist of only resistors .
the electrical properties of such a network @xmath1 are completely described by the _ response matrix _ @xmath2 , which computes the current that flows through the network when certain voltages are fixed at the boundary vertices of @xmath1 .
de verdire - gitler - vertigan @xcite and curtis - ingerman - morrow @xcite studied the _.
Please generate the next two sentences of the article | inverse ( dirichlet - to - neumann ) problem _ for _ circular planar _ electrical networks . specifically , they considered networks embedded in a disk without crossings , with boundary vertices located on the boundary of the disk .
the following theorem summarizes their results . 1 . |
5,644 | Suppose that you have an abstract for a scientific paper: we present a search for the near infrared spectroscopic signature of the close orbiting extrasolar giant planet .
we obtained @xmath0230 spectra in the wavelength range using the phoenix spectrograph at gemini south . by considering the direct spectrum , derived from irradiated model atmospheres , we search for the absorption profile signature present in the combined star and planet light .
since the planetary spectrum is separated from the stellar spectrum at most phases , we apply a phase dependent orbital model and tomographic techniques to search for absorption signatures . because the absorption signature lies buried in the noise of a single exposure we apply a multiline deconvolution to the spectral lines available in order to boost the effective s / n ratio of the data .
the wavelength coverage of 80 is expected to contain @xmath1 planetary lines , enabling a mean line with s / n ratio of 800 to be achieved after deconvolution .
we are nevertheless unable to detect the presence of the planet in the data and carry out further simulations to show that broader wavelength coverage should enable a planet like to be detected with 99.9 per cent ( 4 @xmath2 ) confidence .
we investigate the sensitivity of our method and estimate detection tolerances for mismatches between observed and model planetary atmospheres .
[ firstpage ] line : profiles methods : data analysis techniques : spectroscopic stars : late - type stars : individual : stars : planetary systems .
And you have already written the first three sentences of the full article: [ section : intro ] one of the great surprises in the search for worlds orbiting other stars was the discovery of a class of close orbiting extrasolar giant planets ( cegps ) .
the existence of such objects did not fit with the formation scenarios used to explain the arrangement of planets in our own solar system .
even before the first extrasolar gaseous giants were discovered , core accretion models predicted that they should only form @xcite at distances similar to those of the giant outer planets @xcite . here.
Please generate the next two sentences of the article | temperatures must be cool enough to enable the formation of an ice ( water , methane and ammonia in solid or liquid form ) core from the proto - planetary disk before gas accretion onto the core can then take place . with the announcement of the discovery of the first cegp orbiting the f8 dwarf 51 peg @xcite at a distance of only 0.05 au came the realisation that existing theories of planetary formation needed to be revised .
@xcite argued , contrary to conventional belief @xcite , that gas giant planets could survive in such close proximity , although their formation beyond the ice point was still required . |
5,645 | Suppose that you have an abstract for a scientific paper: we report an implementation of the constrained random phase approximation ( crpa ) method within the projector augmented - wave framework .
it allows for the calculation of the screened interaction in the same wannier orbitals as our recent dft+@xmath0 and dft+dmft implementations .
we present calculations of the dynamical coulomb screened interaction in uranium dioxide and @xmath1 and @xmath2 cerium on wannier functions .
we show that a self - consistent calculation of the static screened interaction in dft+@xmath0 together with a consistent wannier basis is mandatory for @xmath2 cerium and uranium dioxide .
we emphasize that a static approximation for the screened interaction in @xmath1 cerium is too drastic . .
And you have already written the first three sentences of the full article: because of the limited accuracy of available functionals , density functional theory ( dft ) fails for a large number of correlated systems .
there are numerous examples for which dft can not describe neither their ground state properties , nor their excitation properties .
thus , in order to describe many - body effects arising in the strongly correlated systems containing for instance transition elements or @xmath3 electrons , theories were designed to take into account the interaction among correlated orbitals explicitly ..
Please generate the next two sentences of the article | the dft+@xmath0 method@xcite or the combination of dft with dynamical mean field theory method ( dft+dmft ) @xcite have been successfully applied to a large number of systems in the last twenty years . in particular , these methods have been particularly useful to study the ground state and the photoemission spectra of mott insulators such as bulk actinide@xcite and lanthanide oxide@xcite .
for instance , to date dft+dmft is the only method to give a good description of photoemission spectra of both @xmath1 and @xmath2 cerium @xcite . |
5,646 | Suppose that you have an abstract for a scientific paper: luminous ultrasoft nls1s and low - ionization balqsos share many properties , and they both represent important extremes of the active galaxy phenomenon . we briefly discuss their observational similarities as well as potential physical connections between them , concentrating on the x - ray point of view .
we present several ways by which potential connections might be further tested .
galaxies : active ; qsos : general ; x - rays : galaxies .
And you have already written the first three sentences of the full article: it is clear from the papers presented at this workshop that studies of ultrasoft narrow - line seyfert 1 galaxies ( nls1s ) have undergone exciting growth over the past few years .
progress has been made defining their phenomenological properties ; nls1s show extreme spectral shapes and variability at a variety of wavelengths ( e.g. , x - ray , optical and radio ) . while a solid physical understanding of the origin of their extreme properties has not yet emerged , they are plausibly objects with high values of the mass accretion rate relative to the eddington rate ( @xmath0 ) . in this paper
, we will briefly discuss potential connections between luminous nls1s and broad absorption line qsos ( balqsos ) , concentrating on the x - ray point of view ..
Please generate the next two sentences of the article | we will informally advocate such connections to the greatest extent possible in an attempt to stimulate further work in this area . in the x - ray band ,
even the basic phenomenological properties of balqsos are poorly known ( see 2 ) . |
5,647 | Suppose that you have an abstract for a scientific paper: recent experiments on non - interacting ultra - cold atoms in correlated disorder have yielded conflicting results regarding the so - called mobility edge , i.e. the energy threshold separating anderson localized from diffusive states . at the same time , there are theoretical indications that the experimental data overestimate the position of this critical energy , sometimes by a large amount . the non - trivial effect of anisotropy in the spatial correlations of experimental speckle potentials have been put forward as a possible cause for such discrepancy . using extensive numerical simulations
we show that the effect of anisotropy alone is not sufficient to explain the experimental data .
in particular , we find that , for not - too - strong anisotropy , realistic disorder configurations are essentially identical to the isotropic case , modulo a simple rescaling of the energies .
when a wave travels in a random medium , the interference between multiple scattering paths caused by the disorder barriers can completely stop its diffusion .
this phenomenon , known as anderson localization @xcite , is completely general and applies to any kind of waves including light waves in diffusive media @xcite or in photonic crystals @xcite , ultrasound @xcite , microwaves @xcite and atomic matter waves @xcite , the latter describing the behavior of non - interacting atoms in the low temperature quantum regime .
localization experiments using cold atomic gases have several advantages over their solid - state counterparts@xcite .
the inhibition of transport may be directly measured by probing the atomic wavefunction using the time - of - flight technique .
the effect of interactions , that unavoidably hinders localization measurements in solid - state systems , can here be reduced by going from a bose - einstein condensate to a dilute gas or by using feshbach resonances .
lastly , thanks to light - matter interaction , far - detuned laser speckles can be used as tunable disordered potentials for....
And you have already written the first three sentences of the full article: disordered optical potentials used in current experiments are created by shining coherent laser beams through diffusive plates , as sketched in fig . [
fig : speckle ] .
the shift of atomic energy levels due to light - matter coupling is proportional to the intensity of radiation @xmath0 , yielding an effective optical potential @xmath1 for the center - of - mass motion of the atoms , where @xmath2 is the detuning between the laser and atomic transition frequencies @xcite ..
Please generate the next two sentences of the article | we restrict our study to blue - detuned speckles , corresponding to @xmath3 , which are widely used in experiments .
the optical disorder is then always positive and its potential distribution obeys the rayleigh law . without loss of generality |
5,648 | Suppose that you have an abstract for a scientific paper: the hydrodynamic state of an impurity immersed in a low density granular gas is analyzed .
explicit expressions for the temperature and density fields of the impurity in terms of the hydrodynamic fields of the gas are derived .
it is shown that the ratio between the temperatures of the two components , measuring the departure from energy equipartition , only depends on the mechanical properties of the particles , being therefore constant in the bulk of the system .
this ratio plays an important role in determining the density profile of the intruder and its position with respect to the gas , since it determines the sign of the pressure diffusion coefficient .
the theoretical predictions are compared with molecular dynamics simulation results for the particular case of the steady state of an open vibrated granular system in absence of macroscopic fluxes , and a satisfactory agreement is found . .
And you have already written the first three sentences of the full article: as a consequence of the inelasticity of collisions , granular fluids exhibit a series of behaviors that are in sharp contrast with those of molecular fluids .
one of them is the absence of energy equipartition in a granular mixture of mechanically different species .
the granular temperatures of the components of the mixture , defined from the average kinetic energies , are different ..
Please generate the next two sentences of the article | although this possibility was already pointed out many years ago @xcite , it has not been until recently that a systematic study of the effect has been started . for the homogeneous state of a freely cooling binary mixture of inelastic spheres , an explicit expression for the ratio of temperatures of the two components has been obtained from an approximate solution of the kinetic enskog equations @xcite .
the accuracy of this prediction for weak dissipation and low density has been confirmed by molecular dynamics ( md ) simulations @xcite . |
5,649 | Suppose that you have an abstract for a scientific paper: this paper is a review and an update on recent work on the physical and chemical structure of the envelopes of newly born massive stars , at the stages preceding ultracompact h ii regions .
it discusses methods and results to determine total mass , temperature and density structure , ionization rate , and depth - dependent chemical composition . .
And you have already written the first three sentences of the full article: the first major question in the study of high - mass star formation is whether or not the process is a scaled - up version of the formation of low - mass stars , which are known to form by accretion via a disk , and to disperse their natal envelopes through bipolar outflows . at the other extreme , high - mass stars may form by the coagulation of lower - mass stars or protostellar cores ( see reviews by churchwell and by evans in this volume ) .
the second major question of high - mass star formation is its relation to clustered star formation : does the stellar density influence the emergent mass spectrum ? to what degree
do the conditions in the initial molecular cloud determine the properties of the stellar population it produces ?.
Please generate the next two sentences of the article | the study of high - mass star formation is hampered by the short time - scale of the process .
for example , a late o - type star lasts only @xmath01 myr , equal to the pre - main sequence lifetime of a 1 m@xmath1 star . |
5,650 | Suppose that you have an abstract for a scientific paper: the _ x - ray telescope _ ( xrt ) onboard the _ hinode _ satellite is an x - ray imager that observes the solar corona with unprecedentedly high angular resolution ( consistent with its 1@xmath0 pixel size ) .
xrt has nine x - ray analysis filters with different temperature responses .
one of the most significant scientific features of this telescope is its capability of diagnosing coronal temperatures from less than 1 mk to more than 10 mk , which has never been accomplished before . to make full use of this capability ,
accurate calibration of the coronal temperature response of xrt is indispensable and is presented in this article .
the effect of on - orbit contamination is also taken into account in the calibration .
on the basis of our calibration results , we review the coronal - temperature - diagnostic capability of xrt . .
And you have already written the first three sentences of the full article: the outer atmosphere of the sun , the solar corona , is most clearly discernible when seen in soft x - rays . since the early rocket experiments in the late 1960s
, it has become widely recognized that soft x - ray imagery of the sun provides a powerful means to investigate physical conditions of hot plasmas ( whose temperature often exceeds 1 mk ) that prevail in the corona .
coronal imaging with the _ soft x - ray telescope _ ( sxt ).
Please generate the next two sentences of the article | onboard the _ yohkoh _ ( _ solar - a _ ) satellite @xcite ( operation period : 19912001 ) covered a full solar activity cycle and have revealed that magnetic reconnection plays an essential role in the energy release processes in the dynamic solar corona .
the _ solar - b _ satellite was launched at 21:36 ut on 22 september 2006 . |
5,651 | Suppose that you have an abstract for a scientific paper: we present the observation of an extraordinary luminous soft x - ray transient , maxi j0158@xmath0744 , by the monitor of all - sky x - ray image ( maxi ) on 2011 november 11 .
this transient is characterized by a soft x - ray spectrum , a short duration ( @xmath1 s @xmath2 s ) , a very rapid rise ( @xmath3 s ) , and a huge peak luminosity of @xmath4 erg s@xmath5 in [email protected] kev band . with _
swift _ observations and optical spectroscopy from the small and moderate aperture research telescope system ( smarts ) , we confirmed that the transient is a nova explosion , on a white dwarf in a binary with a be star , located near the small magellanic cloud .
an extremely early turn - on of the super - soft x - ray source ( sss ) phase ( @xmath6 d ) , the short sss phase duration of about one month , and a 0.92 kev neon emission line found in the third maxi scan , 1296 s after the first detection , suggest that the explosion involves a small amount of ejecta and is produced on an unusually massive o - ne white dwarf close to , or possibly over , the chandrasekhar limit .
we propose that the huge luminosity detected with maxi was due to the fireball phase , a direct manifestation of the ignition of the thermonuclear runaway process in a nova explosion . .
And you have already written the first three sentences of the full article: classical or recurrent novae are typically characterized by a rapid optical increase of 6 magnitudes or more followed by a decline to quiescence over the next @xmath7 days @xcite .
they originate from an accreting binary system consisting of a white dwarf ( wd ) and a mass - losing late - type companion star .
novae are triggered by thermonuclear runaways ( tnr ) lasting @xmath8 s at the bottom of the accreted mass layer on the wd surface @xcite ..
Please generate the next two sentences of the article | the tnr blows off the outer layer of the accumulated mass and causes an optically thick wind expanding up to @xmath9 .
it produces bright blackbody emission ( @xmath10 erg s@xmath5 , comparable to the eddington luminosity of a @xmath11 object ) at optical bands . |
5,652 | Suppose that you have an abstract for a scientific paper: in the early morning hours of june 1 , 2009 , during a flight from rio de janeiro to paris , air france flight af 447 disappeared during stormy weather over a remote part of the atlantic carrying 228 passengers and crew to their deaths . after two years of unsuccessful search ,
the authors were asked by the french bureau denqutes et danalyses pour la scurit de laviation to develop a probability distribution for the location of the wreckage that accounted for all information about the crash location as well as for previous search efforts .
we used a bayesian procedure developed for search planning to produce the posterior target location distribution .
this distribution was used to guide the search in the third year , and the wreckage was found with one week of undersea search . in this paper
we discuss why bayesian analysis is ideally suited to solving this problem , review previous non - bayesian efforts , and describe the methodology used to produce the posterior probability distribution for the location of the wreck .
, , .
And you have already written the first three sentences of the full article: in the early morning hours of june 1 , 2009 , air france flight af 447 , with 228 passengers and crew aboard , disappeared during stormy weather over the atlantic while on a flight from rio de janeiro to paris . upon receiving notification of the crash ,
the french bureau denqutes et danalyses ( bea ) pour la scurit de laviation and french search and rescue authorities organized an international search by aircraft and surface ships to look for signs of the plane and possible survivors . on the sixth day of this effort , the first debris and bodies were found 38 nm north of the aircraft s last known position .
that day a large portion of the galley was found along with other debris and some bodies ..
Please generate the next two sentences of the article | figure [ figlastknownpos ] shows the aircraft s last known position , intended flight path and a 40 nm circle about the last known position .
analysis by the bea determined that the wreckage had to lie within 40 nm of the plane s last known position . |
5,653 | Suppose that you have an abstract for a scientific paper: we combine techniques from quantum and from classical density functional theory ( dft ) to describe electron - ion mixtures . for homogeneous systems ,
we show how to calculate ion - ion and ion - electron correlation functions within chihara s quantum hypernetted chain approximation , which we derive within a dft formulation .
we also sketch out how to apply the dft formulation to inhomogeneous electron - ion mixtures , and use this to study the electron distribution at the liquid - solid interface of al .
pacs numbers:71.22.+i,61.10.-i,61.20.gy,61.12.bt .
And you have already written the first three sentences of the full article: density functional theory ( dft ) has proven itself a remarkably successful tool in condensed matter physics@xcite .
the foundations were laid in 1964 , when hohenberg and kohn ( hk)@xcite proved that the ground state energy of any quantum mechanical system could be described as a functional of the one - body density only .
subsequently , kohn and sham@xcite developed an orbital based method which could be applied to electronic systems , and mermin@xcite extended the hk proof to finite temperatures , opening up the possibility of using dft to calculate the free - energy of a statistical mechanical system ..
Please generate the next two sentences of the article | since then many different practical methods have been developed to apply dft to electronic problems , with countless applications in condensed matter physics , chemistry , and biology@xcite .
examples of electronic structure techniques relevant to this paper are the _ ab initio _ molecular dynamics ( aimd ) method of car and parrinello@xcite and the orbital free _ ab initio _ molecular dynamics ( of - aimd ) scheme of madden and co - workers@xcite . in a parallel development , |
5,654 | Suppose that you have an abstract for a scientific paper: we theoretically study the phase behaviour of monolayers of hard rod - plate mixtures using a fundamental - measure density functional in the restricted - orientation ( zwanzig ) approximation .
particles can rotate in 3d but their centres of mass are constrained to be on a flat surface .
in addition , we consider both species to be subject to an attractive potential proportional to the particle contact area on the surface and with adsorption strengths that depend on the species type .
particles have board - like shape , with sizes chosen using a symmetry criterion : same volume and same aspect ratio @xmath0 . phase diagrams were calculated for @xmath1 , 20 and 40 and different values of adsorption strengths . for small adsorption strengths the mixtures exhibit a second - order uniaxial nematic - biaxial nematic transition for molar fraction of rods @xmath2 . in the uniaxial nematic phase the particle axes of rods and plates are aligned perpendicular and parallel to the monolayer , respectively . at the transition ,
the orientational symmetry of the plate axes is broken , and they orient parallel to a director lying on the surface . for large and equal adsorption strengths the mixture demixes at low pressures into a uniaxial nematic phase , rich in plates , and a biaxial nematic phase , rich in rods .
the demixing transition is located between two tricritical points .
also , at higher pressures and in the plate - rich part of the phase diagram , the system exhibits a strong first - order uniaxial nematic - biaxial nematic phase transition with a large density coexistence gap . when rod adsorption is considerably large while that of plates is small , the transition to the biaxial nematic phase is always of second order , and its region of stability in the phase diagram considerably widens . at very high pressures the mixture can effectively be identified as a two - dimensional mixture of squares and rectangles which again demixes above a certain critical point .
we also studied the relative....
And you have already written the first three sentences of the full article: it is well known that the properties of biological vesicles and membrane cells strongly depend on the their constituent blocks , usually composed of phospholipid bilayers with embedded proteins .
these molecules are in general anisotropic ( rod or plate - like ) and the demixed states usually have liquid - crystal symmetries , such as isotropic ( i ) , nematic ( n ) or biaxial nematic ( b ) symmetries . for certain conditions these complex mixtures of biomolecules phase separate , creating regions rich in different species and consequently changing the membrane curvature .
there is much experimental evidence of demixing transitions in monolayers and bilayers of mixed anisotropic biomolecules @xcite ..
Please generate the next two sentences of the article | the adsorption of a large variety of mixtures of rod - like molecules in langmuir monolayers has been extensively studied both experimentally and theoretically .
many of these works focus on the chemical and thermodynamic conditions for which the monolayers become spatially heterogeneous , i.e. when the mixture demixes in different phases usually possessing liquid - crystal ordering @xcite . |
5,655 | Suppose that you have an abstract for a scientific paper: the tail chain of a markov chain can be used to model the dependence between extreme observations . for a positive recurrent markov chain , the tail chain aids in describing the limit of a sequence of point processes @xmath0 , consisting of normalized observations plotted against scaled time points . under fairly general conditions on extremal behaviour
, @xmath1 converges to a cluster poisson process .
our technique decomposes the sample path of the chain into i.i.d .
regenerative cycles rather than using blocking argument typically employed in the context of stationarity with mixing . .
And you have already written the first three sentences of the full article: one of the effects of dependence in a time series is that extremes tend to cluster .
this has applied implications to risk contagion over time but is also mathematically interesting and the challenge is to precisely relate the dependence structure to the clustering . for markov dependence ,
how do we describe exceedance clusters ?.
Please generate the next two sentences of the article | point processes powerfully describe extremal behaviour of certain time series . under appropriate conditions on marginal distributions and rapid decay of dependence as a function of time lag for the process @xmath2 ,
the exceedance point process @xmath3 defined by @xmath4 \times(a,\infty ] \bigr ) = \ # \ { j \leq sn : x_j > ab_n \}\ ] ] converges weakly to a poisson limit as @xmath5 , where @xmath6 is a threshold sequence . |
5,656 | Suppose that you have an abstract for a scientific paper: lhcb has been installed by spring 2008 , followed by intensive testing and commissioning of the system in order to be ready for first data taking . despite the horizontal geometry of the lhcb detector it was possible to collect over one million useful cosmic events that allowed a first time alignment of the sub - detectors .
moreover events from beam dumps during the lhc synchronisation tests provided very useful data for further time and spacial alignment of the detector . here
we present an overview of our commissioning activities , the current status and an outlook on the startup in 2009 . .
And you have already written the first three sentences of the full article: the lhcb detector @xcite at the large hadron collider is dedicated to study the physics in the decay of b - flavoured and other heavy hadrons . at the nominal luminosity of @xmath0 at the location of lhcb and a production cross section of @xmath1 at 14tev proton - proton collisions , @xmath2 pairs
are expected to be produced annually .
the modest luminosity requirement for lhcb can be met very early during lhc operation , long before the high luminosity runs and later maintained adjusting the lhc optics when larger luminosities are delivered to the other multi - purpose experiments at the lhc ..
Please generate the next two sentences of the article | lhcb is designed as a single arm forward spectrometer adapted to the angular distribution of the pairs which are produced predominantly at low polar angles as shown in figure [ fig : lhcb ] .
the detector covers an angular region from about 10mrad to 300(250)mrad in the bending ( non - bending ) plane of the magnet . |
5,657 | Suppose that you have an abstract for a scientific paper: we show that , when graphene is only subject to strain , the spin connection gauge field that arises plays no measurable role , but when intrinsic curvature is present and strain is small , spin connection dictates most the physics .
we do so by showing that the weyl field associated with strain is a pure gauge field and no constraint on the @xmath0-dimensional spacetime appears . on the other hand ,
for constant intrinsic curvature that also gives a pure - gauge weyl field , we find a classical manifestation of a quantum weyl anomaly , descending from a constrained spacetime .
we are in the position to do this because we find the equations that the conformal factor in @xmath0-dimensions has to satisfy , that is a nontrivial generalization to @xmath0-dimensions of the classic liouville equation of differential geometry of surfaces .
finally , we comment on the peculiarities of the only gauge field that can describe strain , that is the well known _ pseudogauge field _ @xmath1 and @xmath2 , and conclude by offering some scenarios of fundamental physics that this peculiar field could help to realize . .
And you have already written the first three sentences of the full article: graphene is a very promising table - top laboratory to indirectly probe some of the fundamental mysteries of nature @xcite .
the low energy regime of its @xmath3 electrons is very well described by an effective theory that shares many of the features of a massless dirac quantum field theory ( qft ) in the presence of a background spacetime . in order for graphene to keep its promises ,
we need to have full control of what sort of fields are there and what they represent in a field theory language . in the vast literature on the gauge fields of graphene ( see @xcite , and @xcite for a recent review ) , there are a variety of proposals , sometimes practically valuable for the applications to condensed matter physics , but most of the time unsatisfactory for probing fundamental physics ..
Please generate the next two sentences of the article | the landscape of proposals ranges from @xmath4 monopolelike gauge fields in the case of graphene membranes with intrinsic curvature ( the inflated graphene buckyballs of @xcite ) to a concurrence of a spin - connection field and a @xmath5 field , in the case of purely strained graphene @xcite ( although sometimes non - abelian fields are evoked in this case as well @xcite ) . even in the simplest case , that is purely strained graphene
, there is some confusion : does the spin connection arising from straining graphene give physical effects or not ? and , what is the interpretation of the @xmath5 field from a fundamental point of view ? in this paper , we try to clarify part of this confusion , having in mind to come back to the full scenario of gauge fields in graphene in a forthcoming work . |
5,658 | Suppose that you have an abstract for a scientific paper: we analyze the stability of a cylindrical couette flow under the imposition of a weak axial flow in case of a very short cylinder with a narrow annulus gap .
we consider an incompressible viscous fluid which is contained in the narrow gap between two concentric short cylinders , where the inner cylinder rotates with constant angular velocity . the caps of the cylinders have narrow tubes conically tapering to super narrow slits which allow for an axial flow along the surface of the inner cylinder .
the approximated solution for the couette flow for short cylinders was found and used for the stability analysis instead of the exact but bulky solution .
the sensitivity of the couette flow to general small perturbations and to the weak axial flow was studied .
we demonstrate that perturbations coming from the axial flow cause the propagation of dispersive waves in the taylor - couette flow .
the coexistence of a rotation and of an axial flow requires to study in addition to the energy and the angular momentum also the helicity of the flow .
the approximated form for the helicity formula in case of short cylinders was derived .
we found that the axial flow stabilizes the taylor - couette flow .
the supercritical flow includes a rich variety of vortical structures including a symmetric pair of taylor vortices , an anomalous single vortex and quasi periodic oscillating vortices .
pattern formation was studied at large for rated ranges of azimuthal and axial reynolds numbers .
a region where three branches of different states occur was localized .
numerical simulations in 3d and in axisymmetrical case of the model flow are presented , which illustrate the instabilities analyzed .
* interaction of a rotational motion and an axial flow in small geometries for a couette - taylor problem * l. a. bordag@xmath0 , o. g. chkhetiani@xmath1 , m. frhner@xmath0 and v. myrnyy@xmath0 + @xmath0 _ fakultt mathematik , naturwissenschaften und informatik + brandenburgische technische....
And you have already written the first three sentences of the full article: since the famous experiments of taylor @xcite in long cylinders many experimental and theoretical investigations of the interesting phenomena of arising and evolution of taylor vortices were done .
the main part of these studies was devoted to cases of long cylinders .
it was done under the assumption that a sufficiently long cylinder and periodic boundary conditions will emulate the infinitely long cylindrical region well ..
Please generate the next two sentences of the article | in addition such regions are convenient for theoretical investigations .
the experimental investigations of short cylinders started much later and gave surprising results ( see , for example , benjamin and mullin @xcite ) , which indicated that the zone and the magnitude of the influence of the caps of the cylinders is much bigger and takes effect on the type of motion in the whole region . |
5,659 | Suppose that you have an abstract for a scientific paper: all - versus - nothing ( avn ) proofs show the conflict between einstein , podolsky , and rosen s elements of reality and the perfect correlations of some quantum states . given an @xmath0-qubit state distributed between @xmath1 parties ,
we provide a method with which to decide whether this distribution allows an @xmath1-partite avn proof specific for this state using only single - qubit measurements .
we apply this method to some recently obtained @xmath0-qubit @xmath1-particle states .
in addition , we provide all inequivalent avn proofs with less than nine qubits and a minimum number of parties . .
And you have already written the first three sentences of the full article: einstein , podolsky , and rosen ( epr ) showed that quantum mechanics is incomplete , in the sense that not every element of reality has a counterpart inside the theory @xcite .
epr proposed the following criterion to identify an element of reality : `` if , without in any way disturbing a system , we can predict with certainty ( i.e. , with probability equal to unity ) the value of a physical quantity , then there exists an element of physical reality corresponding to this physical quantity '' @xcite . in practice
, nondisturbance can be guaranteed when the measurements are performed on distant systems ..
Please generate the next two sentences of the article | predictions with certainty are possible for states having perfect correlations .
a quantum state @xmath2 has @xmath3 perfect correlations when there are @xmath3 different observables @xmath4 such that @xmath5 . |
5,660 | Suppose that you have an abstract for a scientific paper: the inverse scattering problem of the three - dimensional schrdinger equation is considered at fixed scattering energy with spherically symmetric potentials .
the phase shifts determine the potential therefore a constructive scheme for recovering the scattering potential from a _
finite _ set of phase shifts at a fixed energy is of interest .
such a scheme is suggested by cox and thompson @xcite and their method is revisited here .
also some new results are added arising from investigation of asymptotics of potentials and concerning statistics of colliding particles .
a condition is given @xcite for the construction of potentials belonging to the class @xmath0 which are the physically meaningful ones .
an uniqueness theorem is obtained @xcite in the special case of one given phase shift by applying the previous condition .
it is shown that if only one phase shift is specified for the inversion procedure the unique potential obtained by the cox - thompson scheme yields the one specified phase shift while the others are small in a certain sense .
the case of two given phase shifts is also discussed by numerical treatment and synthetic examples are given to illustrate the results . besides the new results this contribution provides a systematic treatment of the ct method . .
And you have already written the first three sentences of the full article: we start with the schrdinger equation in @xmath1 at a fixed positive energy @xmath2\psi(x,\alpha)=0\qquad\text{in } \mathbb{r}^3\ ] ] whose scattering solution takes the form @xmath3 where @xmath4 is the direction of the incident wave and @xmath5 is the scattering amplitude .
the following general theorem is due to ramm @xcite .
@xmath6 scattering amplitude @xmath7 , @xmath8 ( arbitrary small open subsets of @xmath9 ) determine @xmath10 uniquely in the function class @xmath11 , @xmath12 ..
Please generate the next two sentences of the article | the present treatment is restricted to spherically symmetric potentials , that is @xmath13 . in this case
we have the partial wave expansion of the wave function : @xmath14 where @xmath15 satisfies the radial schrdinger equation ( see below ) with the appropriate boundary conditions . for |
5,661 | Suppose that you have an abstract for a scientific paper: we propose to use mapreduce to quickly test new retrieval approaches on a cluster of machines by sequentially scanning all documents .
we present a small case study in which we use a cluster of 15 low cost machines to search a web crawl of 0.5 billion pages showing that sequential scanning is a viable approach to running large - scale information retrieval experiments with little effort .
the code is available to other researchers at : http://mirex.sourceforge.net .
And you have already written the first three sentences of the full article: a lot of research in the field of information retrieval aims at improving the _ quality _ of search results .
search quality might for instance be improved by new scoring functions , new indexing approaches , new query ( re-)formulation approaches , etc . to make a scientific judgment of the quality of a new search approach , it is good practice to use so - called benchmark test collections , such as those provided by trec @xcite .
the following steps typically need to be taken : 1 ..
Please generate the next two sentences of the article | the researcher codes the new approach by adapting an experimental search system , such as lemur @xcite , pf / tijah @xcite , or terrier @xcite ; 2 .
the researcher uses the system to create an inverted index on the documents from the test collection ; 3 . |
5,662 | Suppose that you have an abstract for a scientific paper: the process of destroying a complex network through node removal has been the subject of extensive interest and research .
node loss typically leaves the network disintegrated into many small and isolated clusters .
here we show that these clusters typically remain close to each other and we suggest a simple algorithm that is able to reverse the inflicted damage by restoring the network s functionality .
after damage , each node decides independently whether to create a new link depending on the fraction of neighbors it has lost . in addition to relying only on local information , where nodes do not need knowledge of the global network status , we impose the additional constraint that new links should be as short as possible ( i.e. that the new edge completes a shortest possible new cycle ) .
we demonstrate that this self - healing method operates very efficiently , both in model and real networks .
for example , after removing the most connected airports in usa , the self - healing algorithm re - joined almost 90% of the surviving airports . .
And you have already written the first three sentences of the full article: a property of critical importance for complex networks is their resilience to damage or attack @xcite
. one fascinating demonstration of the underlying complexity of these systems is that compromise in structure can be substantial even after the loss of a very small number of nodes @xcite .
the repercussions to the network from this structural compromise can be immense , usually resulting in complete loss of communication among the surviving nodes and therefore a complete destruction of the intended network functionality . because of the obvious importance for practical applications , the robustness of a network s structure to damage has continuously remained the focus of intensive research in the network science literature @xcite ..
Please generate the next two sentences of the article | even though we now have a thorough understanding of complex network disintegration , the inverse process of ` healing ' a network is much less understood .
is there a direct relationship between healing structural features and restoring function ? |
5,663 | Suppose that you have an abstract for a scientific paper: recent progress in the understanding of the complex magnetic properties of the family of rare - earth strontium oxides , @xmath0 , is reviewed .
these compounds consisting of hexagons and triangles are affected by geometrical frustration and therefore exhibit its characteristic features , such as a significant reduction of magnetic ordering temperatures and complex phase diagrams in an applied field .
some of the observed features appear to be rather remarkable even in the context of the unusual behaviour associated in geometrically frustrated magnetic systems .
of particular interest is the coexistence at the lowest temperature of different magnetic structures ( exhibiting either long or short - range order ) characterised by different propagation vectors in materials without significant chemical or structural disorder . .
And you have already written the first three sentences of the full article: frustrated magnets have been a focal point of the research on magnetism for the past two decades . in this article , the influence of geometrical frustration on the magnetic properties of the family of rare - earth strontium oxides , @xmath0 , ( where @xmath1gd , dy , ho , er , tm , and yb ) is discussed . given the nature of this special issue of _ low temperature physics _ on antiferromagnetism an extensive general introduction to magnetically frustrated systems
is omitted and the reader is instead referred to a collection of reviews available on the subject @xcite .
we start with a description of the crystal structure and general properties of @xmath0 and other closely related compounds and then present the recently obtained experimental results on their low - temperature magnetic properties by our group and others ..
Please generate the next two sentences of the article | particular attention is paid to the zero - field ground state of @xmath2 , @xmath3 , and @xmath4 ( section [ section_zero_field ] ) , as well as the field - induced behaviour of these compounds ( section [ section_field ] ) . the penultimate section briefly reviews the other @xmath0 compounds and discusses the importance of crystal field effects .
the concluding section compares different members of the family and includes a brief summary . positions of the magnetic rare - earth @xmath5 ions within the @xmath0 compounds , with the two crystallographically inequivalent @xmath5 sites shown in different colours . |
5,664 | Suppose that you have an abstract for a scientific paper: in active microrheology the mechanical properties of a material are tested by adding probe particles which are pulled by an external force . in case of supercooled liquids ,
strong forcing leads to a thinning of the host material which becomes more pronounced as the system approaches the glass transition . in this work we provide a quantitative theoretical description of this thinning behavior based on the properties of the potential energy landscape ( pel ) of a model glass - former .
a key role plays the trap - like nature of the pel .
we find that the mechanical properties in the strongly driven system behave the same as in a quiescent system at an enhanced temperature , giving rise to a well - characterized effective temperature .
furthermore , this effective temperature turns out to be independent of the chosen observable and individually shows up in the thermodynamic and dynamic properties of the system .
based on this underlying theoretical understanding , we can estimate its dependence on temperature and force by the pel - properties of the quiescent system .
we furthermore critically discuss the relevance of effective temperatures obtained by scaling relations for the description of out - of - equilibrium situations . *
( a ) * * ( b ) * .
And you have already written the first three sentences of the full article: in microrheology , the mechanical properties of a substance are studied by monitoring the trajectories of single particles @xcite .
thereby , one distinguishes between two different modes : passive microrheology , in which the equilibrium properties of the material are probed by studying the motion of a single particle @xcite , and active microrheology , in which a single particle is subjected to an external drive . in the latter case ,
the response to strong external perturbations is of particular interest since it allows one to study the properties of the system in an out - of - equilibrium situation @xcite ..
Please generate the next two sentences of the article | recently , this method has been applied to study the properties of glass - forming systems in both , experiments @xcite and simulations @xcite . for these systems ,
several remarkable effects have been observed like a nonlinear thinning of supercooled liquids @xcite , local melting of glassy samples @xcite and intermittent superdiffusivity in the supercooled regime @xcite . because of this , there is recently a field of vivid research to provide a theoretical description of the out - of - equilibrium properties @xcite , mostly in the framework of mode - coupling theory @xcite . for diluted colloidal solutions , |
5,665 | Suppose that you have an abstract for a scientific paper: data from e772 and e866 experiments on the drell - yan process exhibit a significant nuclear suppression at large feynman @xmath0 .
we show that a corresponding kinematic region does not allow to interpret this as a manifestation of coherence or a color glass condensate .
we demonstrate , however , that this suppression can be treated alternatively as an effective energy loss proportional to initial energy . to eliminate suppression coming from the coherence , we perform predictions for nuclear effects also at large dilepton masses .
our calculations are in a good agreement with available data . since the kinematic limit can be also approached in transverse momenta @xmath1 , we present in the rhic energy range corresponding predictions for expected large-@xmath1 suppression as well .
since a new experiment e906 planned at fnal will provide us with more precise data soon , we present also predictions for expected large-@xmath0 nuclear suppression in this kinematic region . .
And you have already written the first three sentences of the full article: in comparison with a central region of very small rapidities , @xmath2 , the forward rapidity region allows to study processes corresponding to much higher initial energies accessible at mid rapidities .
if a particle with mass @xmath3 and transverse momentum @xmath1 is produced in a hard reaction then the corresponding values of bjorken variable in the beam and the target are @xmath4 .
thus , at forward rapidities the target @xmath5 is @xmath6- times smaller than at mid rapidities ..
Please generate the next two sentences of the article | this allows to study already at rhic coherence phenomena ( shadowing , color glass condensate ( cgc ) ) , which are expected to suppress particle yields .
forward rapidity physics , manifested itself as a strong nuclear suppression , has been already investigated in variety of processes at different energies : in production of different species of particles in @xmath7 collisions @xcite , in charge pion @xcite and charmonium production @xcite at sps , in the drell - yan process and charmonium production at fermilab @xcite and later on at larger rhic energies by measurements of high-@xmath1 particles in @xmath8 collisions @xcite . |
5,666 | Suppose that you have an abstract for a scientific paper: in this paper we investigate the extension of the charged riemannian penrose inequality to the case where charges are present outside the horizon .
we prove a positive result when the charge densities are compactly supported , and present a counterexample when the charges extend to infinity .
we also discuss additional extensions to other matter models . .
And you have already written the first three sentences of the full article: in @xcite , we proved the riemmanian penrose inequality with charge for multiple black holes . [ crpi ]
let @xmath0 be a strongly asymptotically flat initial data set for the einstein - maxwell equations with outermost minimal surface boundary of area @xmath1 , with adm mass @xmath2 , and total charge @xmath3 , satisfying the charged dominant energy condition and the maxwell constraints without charged matter . then @xmath4 with equality if and only if the data set arises as the canonical slice of the reissner - nordstrm spacetime .
here @xmath5 is a three dimensional manifold , @xmath6 a riemannian metric on @xmath5 , @xmath7 and @xmath8 vector fields on @xmath5 , and @xmath9 is called the _ area radius _ of the outermost minimal surface . when @xmath10 , the positive mass theorem with charge @xcite , @xmath11 , which was accomplished with the following result ..
Please generate the next two sentences of the article | [ thm - imcf ] let @xmath0 be a strongly asymptotically flat initial data set for the einstein - maxwell equations with outermost minimal surface boundary of area @xmath1 , with adm mass @xmath2 , and total charge @xmath3 , satisfying the charged dominant energy condition and the maxwell constraints without charged matter .
if @xmath12 , then @xmath13 with equality if and only if the data set arises as the canonical slice of the reissner - nordstrm spacetime . we proved this theorem using a conformal flow method adapted from @xcite . in @xcite , |
5,667 | Suppose that you have an abstract for a scientific paper: there are several topological spaces associated to a complex hyperplane arrangement : the complement and its boundary manifold , as well as the milnor fiber and its own boundary .
all these spaces are related in various ways , primarily by a set of interlocking fibrations .
we use cohomology with coefficients in rank @xmath0 local systems on the complement of the arrangement to gain information on the homology of the other three spaces , and on the monodromy operators of the various fibrations .
tant donn un arrangement dhyperplans , il y a plusieurs espaces topologiques quon puisse lui associer : le complmentaire et sa varit de bord , ainsi que la fibre de milnor et son bord .
tous ces espaces sont relis , en premier lieu par des fibrations .
on utilise la cohomologie avec coefficients dans les systmes locaux de rang @xmath0 sur le complmentaire dun arrangement dhyperplans pour tudier lhomologie des trois autres espaces , et les oprateurs de monodromie des fibrations associes . .
And you have already written the first three sentences of the full article: this paper is mostly an expository survey , centered on the topology of complements of hyperplane arrangements , their milnor fibrations , and their boundary structures .
the presentation is loosely based on a set of notes for a mini - course given at the conference
arrangements in pyrnes " , held in pau , france in june 2012 . although we expanded the scope of those notes , and provided many more details and explanations , we made every effort to maintain the original spirit of the lectures , which was to give a brisk , self - contained introduction to the subject , and provide motivation for further study ..
Please generate the next two sentences of the article | an arrangement is a finite collection of hyperplanes in a finite - dimensional , complex vector space .
there are various ways to understand the topology of such an object . in this paper , we describe several topological spaces associated to a hyperplane arrangement , all connected to each other by means of inclusions , bundle maps , or covering projections . associated to these spaces , there is a plethora of topological invariants of an algebraic nature : fundamental group and lower central series , betti numbers and torsion coefficients , cohomology ring and massey products , characteristic and resonance varieties , and so on . |
5,668 | Suppose that you have an abstract for a scientific paper: we consider double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive @xmath0 production which is connected with @xmath1 asymmetry .
the predicted asymmetry is large and can be used to obtain the information on the polarized skewed gluon distributions in the proton . .
And you have already written the first three sentences of the full article: sensitivity of diffractive lepto and photoproduction to the gluon density in the proton gives an excellent tool to test these structure functions .
intensive experimental study of diffractive processes were performed in desy @xcite .
theoretical analysis shows that the cross sections of diffractive hadron production are expressed in terms of skewed parton distributions ( spd ) @xcite ..
Please generate the next two sentences of the article | the diffractive charm @xmath0 production and @xmath2 production are determined by the gluon spd @xmath3 because the charm component in the proton is small . for
light hadron production effects of the quark spd should be important for not small @xmath4 . in the polarized case |
5,669 | Suppose that you have an abstract for a scientific paper: the passage - time distribution for a spread - out quantum particle to traverse a specific region is calculated using a detailed quantum model for the detector involved .
that model , developed and investigated in earlier works , is based on the detected particle s enhancement of the coupling between a collection of spins ( in a metastable state ) and their environment .
we treat the continuum limit of the model , under the assumption of the markov property , and calculate the particle state immediately after the first detection .
an explicit example with 15 boson modes shows excellent agreement between the discrete model and the continuum limit .
analytical expressions for the passage - time distribution as well as numerical examples are presented .
the precision of the measurement scheme is estimated and its optimization discussed . for slow particles ,
the precision goes like @xmath0 , which improves previous @xmath1 estimates , obtained with a quantum clock model . .
And you have already written the first three sentences of the full article: time - of - flight measurements are a standard tool for many experimentalists . since the particles or atoms involved are usually fast , their center - of - mass motion is typically treated classically , yielding a simple description of the time - of - flight measurement . but as the diffraction and interference experiments using temporal ( instead of spatial ) slits of szriftgiser et .
al have shown @xcite , such a description of the center - of - mass motion by means of classical physics is not always sufficient : the advance of cooling techniques has made it possible to create ultracold gases in a trap and produce very slow atoms , e.g. , by opening the trap .
whenever such ultracold atoms are involved , the spatial extent and the spreading of the wave function can show noticeable effects ..
Please generate the next two sentences of the article | even the seemingly simple question of the time spent by a particle in a given region of space does not possess a simple and definite answer .
related to this `` dwell - time '' problem are the problems of `` passage time , '' concentrating on those particles that actually cross the region of interest and are not reflected , and `` tunneling time '' in the case of a barrier that classically can not be traversed inside the region of interest . |
5,670 | Suppose that you have an abstract for a scientific paper: the fabrication of artificial pinning structures allows a new generation of experiments which can probe the properties of vortex arrays by forcing them to flow in confined geometries .
we discuss the theoretical analysis of such experiments in both flux liquids and flux solids , focusing on the corbino disk geometry . in the liquid , these experiments can probe the critical behavior near a continuous liquid - glass transition . in the solid , they probe
directly the onset of plasticity . .
And you have already written the first three sentences of the full article: in the mixed state of type - ii superconductors the magnetic field is concentrated in an array of flexible flux bundles that , much like ordinary matter , can form crystalline , liquid and glassy phases.@xcite in clean systems the vortex solid melts into a flux liquid via a first order phase transition.@xcite if the barriers to vortex line crossing are high , a rapidly cooled vortex liquid can bypass the crystal phase and get trapped in a metastable polymer - like glass phase.@xcite the diversity of vortex structures is further increased by pinning from material disorder , which leads to a variety of novel glasses .
disorder - driven glass transitions are continuous , with diverging correlation lengths and universal critical behavior.@xcite of particular interest is the dynamics of the vortex array in the various phases and in the proximity of a phase transition . in the liquid phase the vortex array flows yielding a linear resistivity . in the presence of large scale spatial inhomogeneities , the liquid flow can be highly nonlocal due to interactions and entanglement.@xcite the correlation length controlling the nonlocality of the flow grows with the liquid shear viscosity , which becomes large as the liquid freezes . at a continuous liquid - glass transition this correlation length diverges with a universal critical exponent . in the solid phase the vortex array moves as a single elastic object under uniform drive ,
provided the shear stresses are not too large . in the presence of strong spatial inhomogeneities.
Please generate the next two sentences of the article | , plastic flow occurs for large drives ( or even for vanishingly small drives in a glassy solid ) and the response is always nonlinear.@xcite the dynamical correlation length can be identified with the separation between free dislocations and diverges at a continuous melting transition . probing spatial velocity correlations can therefore give information on vortex dynamics within a given phase , as well as on the nature of the phase transitions connecting the various phases .
as for ordinary matter , the shear rigidity of the vortex array can be probed by forcing the vortices to flow in confined geometries . |
5,671 | Suppose that you have an abstract for a scientific paper: the lennard - jones ( lj ) potential energy problem is to construct the most stable form of @xmath0 atoms of a molecule with the minimal lj potential energy .
this problem has a simple mathematical form @xmath1 where @xmath2 , @xmath3 is the coordinates of atom @xmath4 in @xmath5 , @xmath6 , and @xmath7 ; however it is a challenging and difficult problem for many optimization methods when @xmath0 is larger . in this paper ,
a brief review and a bibliography of important computational algorithms on minimizing the lj potential energy are introduced in sections 1 and 2 .
section 3 of this paper illuminates many beautiful graphs ( gotten by the author nearly 10 years ago ) for the three dimensional structures of molecules with minimal lj potential . * a brief review on results and computational algorithms for minimizing the lennard - jones potential * * jiapu zhang * _ centre for informatics and applied optimization & + graduate school of information technology and mathematical sciences , + university of ballarat , victoria 3353 , australia _ 0.2 cm .
And you have already written the first three sentences of the full article: the lennard - jones potential energy problem is to construct the most stable form of @xmath0 atoms of some material with the minimal energy structure .
its form in mathematics is very simple : @xmath8 where @xmath2 , @xmath9 is the coordinates of atom @xmath4 , @xmath6 , and @xmath7 .
however , it interests many researchers in the field of biology , physics , chemistry , mathematical optimization , computer science , and materials science ..
Please generate the next two sentences of the article | the reason lies in the nonconvexity of the objective function and the huge number of local minima , which is growing exponentially with @xmath0 .
@xcite tells us the number of distinct local minima of @xmath0-atoms lennard - jones problem is about @xmath10 . |
5,672 | Suppose that you have an abstract for a scientific paper: we give a characterization of transport - entropy inequalities in metric spaces . as an application
we deduce that such inequalities are stable under bounded perturbation ( holley - stroock perturbation lemma ) . .
And you have already written the first three sentences of the full article: in their celebrated paper @xcite , otto and villani proved that , in a smooth riemannian setting , the log - sobolev inequality implies the talagrand s transport - entropy inequality @xmath0 .
later , bobkov , gentil and ledoux @xcite proposed an alternative proof of this result .
both approaches are based on semi - group arguments ..
Please generate the next two sentences of the article | more recently , the first named author gave a new proof , based on large deviation theory , valid on metric spaces @xcite . in this paper , on the one hand ,
we give yet another proof of otto and villani s theorem . |
5,673 | Suppose that you have an abstract for a scientific paper: we present high resolution two dimensional velocity fields from integral field spectroscopy along with derived rotation curves for nine low surface brightness galaxies .
this is a positive step forward in terms of both data quality and number of objects studied .
we fit nfw and pseudo - isothermal halo models to the observations .
we find that the pseudo - isothermal halo better represents the data in most cases than the nfw halo , as the resulting concentrations are lower than would be expected for @xmath0cdm . .
And you have already written the first three sentences of the full article: are the dark matter halos of lsb galaxies `` cuspy '' nfw halos , or are they `` cored '' isothermal halos ?
nfw halos can be fit to the observations , but the cosmological parameters implied by the fits are inconsistent with the standard lcdm picture .
isothermal halos provide much better fits , but they have no cosmological dependence or theoretical basis ..
Please generate the next two sentences of the article | we address this question with new data that is both high resolution and two - dimensional .
we observed 12 lsb galaxies using the densepak integrated field unit on the wiyn telescope at kitt peak . |
5,674 | Suppose that you have an abstract for a scientific paper: -1.1 cm using the open quantum system approach applied to the neutrino system , we derive three generations neutrino probability formulae considering the oscillation induced by mass plus quantum decoherence contributions .
the introduction of these dissipative effects is done through the quantum dynamical semigroup formalism .
in addition to the theoretical interest of the approach , at least from the completeness point of view , this extension of the formalism to the three flavors , provide us with a direct application : we can analyze qualitatively the consistency of the two generation pure decoherence solution to the atmospheric neutrino problem , accommodated within this enlarged scheme , with the mean tendencies observed for some of the current neutrino experimental data .
this study was performed based on different choices of the @xmath0 mixing matrix selected in order to adjust the @xmath1 to the same form it has for the decoherence solution in two generations .
our qualitative tests for decoherence with three neutrinos show a clear incompatibility between neutrino data and the theoretical expectations .
15truecm -0.4truecm 22truecm
1.truecm 1.truecm = .
And you have already written the first three sentences of the full article: in the open quantum system approach@xcite , the evolution of a system interacting with an environment is described in an effective way , that is , the interaction with the environment is incorporated in the description of the evolution of the system . in general , the effects produced by the interaction cause dissipation and irreversibility .
this treatment was originally developed for quantum optics@xcite , in order to take into account the system - reservoir ( environment ) interaction , and it has already been applied to elementary particle systems .
recently , it has also been used in the study of two neutrino oscillations@xcite , modifying the well known oscillation probability , due to the presence of dissipative effects ..
Please generate the next two sentences of the article | one very interesting feature of the oscillation probability in this situation is that even in the case that neutrinos are massless , we can have neutrino flavor conversion@xcite .
it has been pointed out that this mechanism is able to explain well , in the context of two generations , the atmospheric neutrino data collected by the super - kamiokande ( sk ) experiment@xcite , as long as the damping parameter is @xmath2 , @xmath3 being the neutrino energy . |
5,675 | Suppose that you have an abstract for a scientific paper: a precise determination of @xmath0 can be obtained exploiting the sum rule for inclusive charmless semileptonic @xmath1-meson decays .
the sum rule is derived on the basis of light - cone expansion and @xmath2-flavored quantum number conservation .
the sum rule does not receive any perturbative qcd correction . in this determination of @xmath0
, there is no perturbative qcd uncertainty , while the dominant hadronic uncertainty is avoided .
moreover , this method is not only theoretically quite clean , but experimentally also very efficient in the discrimination between @xmath3 signal and @xmath4 background .
the sum rule requires measuring the lepton pair spectrum .
we analyze the lepton pair spectrum , including the leading perturbative and nonperturbative qcd corrections . .
And you have already written the first three sentences of the full article: the measurement of the cabibbo - kobayashi - maskawa ( ckm ) matrix @xcite element @xmath0 is currently one of the important goals of @xmath1 physics .
standard model predictions employ the fundamental parameter @xmath0 as input . as the experiments at the @xmath1 factories are starting to take data , a precise determination of @xmath0 is increasingly vital for testing the standard model .
for example , the standard model prediction for the cp - violating asymmetry in @xmath5 decays depends on the value of @xmath0 ..
Please generate the next two sentences of the article | evidence for the cp - violating asymmetry has already been provided by the cdf collaboration @xcite . as the dedicated experiments are expected to achieve much greater precision ,
an increase in the accuracy of @xmath0 is highly desirable in order to test whether the complex phase of the ckm matrix is the only source of cp violation . on the other hand , despite empirical successes , the standard model is definitely not the final theory of particle physics . |
5,676 | Suppose that you have an abstract for a scientific paper: on - demand vehicle access is a method that can be used to reduce types of range anxiety problems related to planned travel for electric vehicle owners . using ideas from elementary queueing theory ,
basic qos metrics are defined to dimension a shared fleet to ensure high levels of vehicle access . using mobility data from ireland
, it is argued that the potential cost of such a system is very low .
* keywords : * electric vehicles ; range anxiety ; on - demand vehicle access .
And you have already written the first three sentences of the full article: growing concerns over the limited supply of fossil - based fuels are motivating intense activity in the search for alternative road transportation propulsion systems . regulatory pressures to reduce urban pollution ,
@xmath0 emissions and city noise have made electric vehicles ( evs ) @xcite and plug - in hybrid vehicles ( phevs ) @xcite a very attractive choice as the alternative to the internal combustion engine ( ice ) @xcite .
electric vehicles in particular , which have zero tailpipe emissions of pollutants , are seen as a very useful tool in reducing urban pollution due to the fact that they deliver energy in a clean form in our cities , as well as reducing the carbon footprint of road transportation generally when combined with clean energy generation ..
Please generate the next two sentences of the article | while the environmental and societal benefits of zero - emission vehicles are evident , their adoption by users has been extremely disappointing .
according to recent reports @xcite , even in europe , where the green agenda is well received , fewer than 12000 electric vehicles were sold in the first half of 2012 ( of which only 1000 of these were sold in the uk ) . |
5,677 | Suppose that you have an abstract for a scientific paper: we use the one - dimensional object - oriented particle - in - cell monte carlo collision code oopd1 to explore the spatio - temporal evolution of the electron heating mechanism in a capacitively coupled oxygen discharge in the pressure range 10 200 mtorr .
the electron heating is most significant in the sheath vicinity during the sheath expansion phase .
we explore how including and excluding detachment by the singlet metastable states o@xmath0(a@xmath1 ) and o@xmath0(b@xmath2 ) influences the heating mechanism , the effective electron temperature and electronegativity , in the oxygen discharge .
we demonstrate that the detachment processes have a significant influence on the discharge properties , in particular for the higher pressures . at 10 mtorr
the time averaged electron heating shows mainly ohmic heating in the plasma bulk ( the electronegative core ) and at higher pressures there is no ohmic heating in the plasma bulk , that is electron heating in the sheath regions dominates . .
And you have already written the first three sentences of the full article: capacitively coupled plasma ( ccp ) radio frequency discharges are frequently used for applications such as plasma etching or plasma enhanced chemical vapor deposition ( pecvd ) processes in integrated circuit manufacturing .
impact by energetic electrons leads to dissociation and ionization of feedstock gas , and thus creation of reactive radicals and ions .
these applications usually require feedstock gases that are complex mixtures of reactive gases , often electronegative ..
Please generate the next two sentences of the article | one such electronegative discharge is the oxygen discharge .
the oxygen discharge and its mixtures are of significance in various materials processing applications including etching of polymer films , ashing of photoresist , oxidation , and deposition of oxide films . |
5,678 | Suppose that you have an abstract for a scientific paper: we present a study of the x - ray emission from binary systems extracted from the lindroos catalogue ( lindroos 1986 ) based on the rosat all - sky survey as well as rosat pspc and hri pointings .
the studied sample consists of visual binary systems comprised of early - type primaries and late - type secondaries .
the ages of the systems were determined by lindroos ( 1985 ) from uvby@xmath0 photometry of the primaries .
these ages range between 33 and 135 myr , so if the late - type secondaries are physically bound to the early - type primaries , they could be post - t tauri stars ( ptts ) .
we have found strong x - ray emission from several secondaries .
this fact together with their optical and ir data , make them _ bona fide _ ptts candidates .
we have also detected x - ray emission from several early - type primaries and , in particular , from most of the late - b type stars .
because their hri hardness ratios are similar to those from resolved late - type stars , the presence of an unresolved late - type companion seems to be the cause of this emission . .
And you have already written the first three sentences of the full article: pre - main sequence ( pms ) late - type stars are known to be x - ray sources ( see walter et al .
1988 , bouvier 1990 and neuhuser et al .
1995 ) . in the evolution of these stars to the main sequence ( ms ) , there is a state usually defined as post - t tauri stars ( ptts ) ..
Please generate the next two sentences of the article | ptts were first defined by herbig ( 1978 ) as pms stars more evolved than classical t tauri stars ( ctts ) but still contracting to the ms .
given that the stage of ctts is only a small fraction of the total time of contraction of low - mass stars to the ms , ptts should be much more abundant than ctts if star formation has been ongoing for a sufficiently long time . however , it is difficult to find ptts because they do not show spectroscopic or photometric peculiarities which make them easy to detect . |
5,679 | Suppose that you have an abstract for a scientific paper: calculations of the @xmath0he@xmath1si total reaction cross sections at intermediate energies are performed on the basis of the glauber - sitenko microscopic optical - limit model .
the target - nucleus density distribution is taken from the electron - nucleus scattering data , and the @xmath0he densities are used as they are derived in different models .
the results of the calculations are compared with the existing experimental data .
the effects of the density tails of the projectile nuclei as well as the role of shell admixtures and short - range correlations are analyzed .
* testing @xmath0he density distributions by calculations of + total reaction cross - sections of @xmath0he+@xmath2si * + [ .3 cm ] v.k .
lukyanov , e.v .
zemlyanaya + _ joint institute for nuclear research , dubna 141980 , russia
_ + s.e .
massen , ch.c .
moustakidis + _ aristotle university of thessaloniki , greece _
+ a.n .
antonov + _ institute for nuclear research and nuclear energy , sofia 1784 , bulgaria _ + g.z .
krumova + _ university of rousse , rousse 7017 , bulgaria _ .
And you have already written the first three sentences of the full article: 0 the study of the matter distributions in the borromean nucleus @xmath3 and the neutron rich isotope @xmath4 is an actual problem discussed in many papers ( see , e.g. , in @xcite and refs . therein ) .
investigations give a reason to expect long tails ( halo ) of the neutron densities .
the first result on the enhancement of the strong interaction radii @xmath5 for @xmath6 was deduced in @xcite from measurements of their interaction cross sections with different target nuclei at fixed energy 800 mev / nucleon ..
Please generate the next two sentences of the article | the same conclusion was made in @xcite about the @xmath0he @xmath7-radii .
later in @xcite , the model densities in the form of a sum of two gaussian functions @xcite were fitted to the data and a conclusion for a significant neutron halo in the outer region of these nuclei was made . |
5,680 | Suppose that you have an abstract for a scientific paper: the form of the leptonic mixing matrix emerging from experiment has , in the last few years , generated a lot of interest in the so - called tribimaximal type .
this form may be naturally associated with the possibility of a discrete permutation symmetry ( @xmath0 ) among the three generations . however , trying to implement this attractive symmetry has resulted in some problems and it seems to have fallen out of favor .
we suggest an approach in which the @xmath0 holds to first approximation , somewhat in the manner of the old @xmath1 flavor symmetry of the three flavor quark model . it is shown that in the case of the neutrino sector , a presently large experimentally allowed region can be fairly well described in this first approximation .
we briefly discuss the nature of the perturbations which are the analogs of the gell - mann okubo perturbations but confine our attention for the most part to the @xmath0 invariant model .
we postulate that the @xmath0 invariant mass spectrum consists of non zero masses for the @xmath2 and zero masses for the other charged fermions but approximately degenerate masses for the three neutrinos .
the mixing matrices are assumed to be trivial for the charged fermions but of tribimaximal type for the neutrinos in the first approximation .
it is shown that this can be implemented by allowing complex entries for the mass matrix and spontaneous breakdown of the @xmath0 invariance of the lagrangian . .
And you have already written the first three sentences of the full article: it is generally considered that a full understanding of the masses and associated mixings of the quarks and leptons is one of the chief unsolved problems in elementary particle physics .
while a great deal of experimental knowledge about quark masses and mixings has been available for quite a long time , it is only in the last few years that very detailed information on lepton masses and mixings has been found from a series of remarkable experiments involving neutrino oscillations ( see for some examples , refs ) .
these results can be expected to provide valuable clues toward the solution of this mass and mixing problem ..
Please generate the next two sentences of the article | one such clue is the fact that the leptonic mixing matrix is now known to be somewhat close to what is called the `` tribimaximal '' form ; actually a number of interesting discussions of this form have been presented over a period of years . for immediate convenience
this form may be read from eq.([r ] ) below and it can be seen that one column has three equal entries while another has two entries of equal magnitude with the third zero . such a structure is natural in the context of permutation symmetry since it is a characteristic one which brings the basis of the defining representation of @xmath0 ( the permutation group on three objects ) to the basis in which it is decomposed into two and one dimensional irreducible pieces . of course |
5,681 | Suppose that you have an abstract for a scientific paper: we present the results of a combined analysis of cosmic microwave background ( cmb ) and x - ray galaxy clusters baryon fraction to deduce constraints over 6 inflationnary cosmological parameters .
such a combination is necessary for breaking degeneracies inherent to the cmb .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: since their first detection by cobe , the cmb temperature fluctuations have become an essential tool for constraining cosmological parameters . from the beginning of 2000 , new experiments have released data set of good quality up to the third acoustic peak .
better constraints have been obtained on several cosmological parameters .
nevertheless , it has been shown that even with precise measurements of the power spectrum , it is nearly impossible to distinguish models with the same physical parameters on the last scattering surface . basically , some degeneracies are inherent to the cmb . we consider in this work x.
Please generate the next two sentences of the article | ray clusters as an independent way for constraining cosmological parameters .
in the present analysis we consider the data from cobe , boomerang , maxima and dasi . |
5,682 | Suppose that you have an abstract for a scientific paper: we describe here how the late time behavior of the decaying states , which is predicted to deviate from an exponential form , while normally of insignificant consequence , may have important cosmological implications in the case of false vacuum decay .
it may increase the likelihood of eternal inflation , and may help explain the likelihood of observing a small vacuum energy at late times , as well as arguing against decay into a large negative energy ( anti - de sitter space ) , vacuum state as has been motivated by some string theory considerations .
several interesting open questions are raised , including whether observing the cosmological configuration of a metastable universe can constrain its inferred lifetime . .
And you have already written the first three sentences of the full article: it is not commonly known , but nevertheless well established since the work of khalfin in 1958@xcite , extended by numerous other authors in the intervening years ( i.e. @xcite that for times long compared to the characteristic decay time of a metastable quantum state , the decay of such states is no longer described by an exponential , but rather by a power law .
one of the reasons that this interesting fact is perhaps not more well recognized is that the characteristic time - scale determined for departures from exponential decay in several sample systems is generally so long that for all intents and purposes all unstable states in any finite system will have decayed before this onset would become relevant .
however , if one generalizes the results from quantum mechanics to quantum field theory then the nature of false vacuum decay can altered , with potentially significant implications for cosmology , as we describe here ..
Please generate the next two sentences of the article | we begin by exploring the generic features of late - time decay , examining the transition from quantum mechanics to quantum field theory in order to explore those implications that are independent of the details of the relevant potential or model , in order to consider their impact upon the dynamics of cosmological false vacuum decay .
we find that the time for departures from exponential growth should depend logarithmically on ratio of the energy gap and the decay width with a prefactor of order unity and then explore the cosmological implications of this . |
5,683 | Suppose that you have an abstract for a scientific paper: the supersymmetric extension to the standard model offers a promising cold dark matter candidate , the lightest neutralino .
i will review the phenomenological and cosmological constraints on the supersymmetric parameter space and discuss the prospects for the detection of this candidate in both accelerator and direct detection searches .
0.0 in -0.5 in 12m_1/2 hep - ph/0211064 + tpi minn02/45 + umn th2117/02 + november 2002 * cdm in supersymmetric models * keith a. olive@xmath0 @xmath1_theoretical physics institute , school of physics and astronomy , + university of minnesota , minneapolis , mn 55455 _ .
And you have already written the first three sentences of the full article: it is well known that supersymmetric models with conserved @xmath2-parity contain one new stable particle which is a candidate for cold dark matter ( cdm ) @xcite .
there are very strong constraints , however , forbidding the existence of stable or long lived particles which are not color and electrically neutral .
strong and electromagnetically interacting lsps would become bound with normal matter forming anomalously heavy isotopes . indeed , there are very strong upper limits on the abundances , relative to hydrogen , of nuclear isotopes @xcite , @xmath3 for 1 gev @xmath4 1 tev ..
Please generate the next two sentences of the article | a strongly interacting stable relic is expected to have an abundance @xmath5 with a higher abundance for charged particles .
there are relatively few supersymmetric candidates which are not colored and are electrically neutral . |
5,684 | Suppose that you have an abstract for a scientific paper: we study the role of finite widths of resonances in a nonlocal version of the wick - cutkosky model .
the spectrum of bound states is known analytically in this model and forms linear regge tragectories .
we compute the widths of resonances , calculate the spectral density in an extension of the breit - wigner _ ansatz _ and discuss a mechanism for the damping of unphysical exponential growth of observables at high energy due to finite widths of resonances . .
And you have already written the first three sentences of the full article: behaviour in field theories with nonlocal interactions in the time - like momentum region is the central concern of this paper .
nonlocal quantum field theory has a long history .
initially it was invented as an attempt at solving the problem of uv divergences ..
Please generate the next two sentences of the article | however after the development of renormalisation techniques for local qft the study of nonlocal interactions became a field of academic interest .
nevertheless the challenge of constructing self - consistent and mathematically rigorous quantum field theories with nonlocal interactions and their phenomenological application have been attracting permanent attention . as a result of this long activity of several decades the general principles of quantisation of nonlocal field theories have been formulated . |
5,685 | Suppose that you have an abstract for a scientific paper: the current paradigm for radio - quiet agns is reviewed , taking into account new results from recent large - scale surveys carried out from the ground and from space .
topics include structure of the central engine , agn demography , fueling / triggering processes , and connection between the supermassive black hole , host galaxy , circumnuclear starburst and agn .
dependences on agn power and lookback time are pointed out in the discussion .
suggestions for future avenues of research are mentioned in the last section . .
And you have already written the first three sentences of the full article: a quick search through the nasa / ads abstract service indicates that more than @xmath0 5000 papers were published over the past five years on agns ! clearly , a comprehensive review of this literature is well beyond the scope of the present article .
the present review highlights important results from recent large - scale ground - based surveys and space missions , and describes the consequences of these results on our understanding of radio - quiet agns .
the standard paradigm for radio - quiet agns is described in 2 along with a few key supporting observations ..
Please generate the next two sentences of the article | important new constraints on this standard picture have been derived from recent uv / optical , infrared , and x - ray surveys ; these are discussed in 3 . in 4 , the nature of the connection between the supermassive black hole , host galaxy , circumnuclear starburst , and agn is briefly reviewed taking into account recent new data .
the issue of agn fueling / triggering is addressed in 5 . |
5,686 | Suppose that you have an abstract for a scientific paper: we calculate the branching ratios of @xmath0 decay in the sequential fourth generation model .
we find that the theoretical values of the branching ratios , @xmath1 , including the contributions of @xmath2 , are much different from the minimal standard model ( sm ) predictions .
the new physics contribution can provide one to two orders enhancement to the standard model prediction of @xmath1 .
but due to the tiny values of 4th generation ckm matrix element @xmath3 , the new physics effect on @xmath4 is very small and can not be distinct from the sm prediction .
it is shown that the decay @xmath5 can give the test of new physics signals from the 4th generation model . .
And you have already written the first three sentences of the full article: the minimal standard model ( sm ) is a very successful theory of the elementary particles known today .
but it should not be the final theory , because it has too many unknown parameters to be put by hand .
most of these parameters are in the fermion part of the theory ..
Please generate the next two sentences of the article | we do nt know the origin of the quarks and leptons , as well as how to determinate their mass and number theoretically .
we have to get their information all from experiments . |
5,687 | Suppose that you have an abstract for a scientific paper: in part i. of this work we have presented evidence that the measured relative phases of transversity amplitudes in @xmath0 processes differ from those predicted by the unitary evolution law .
we ascribed this difference to a non - unitary interaction of the produced final state @xmath1 with a universal quantum environment in the physical universe .
this new kind of interaction must be a pure dephasing interaction in order to render the @xmath2-matrix dynamics of particle scattering processes accessible to experimental observation .
if the quantum environment is to be an integral part of the nature then its dephasing interactions must be fully consistent with the standard model .
in this work we impose on the dephasing interaction the requirements of the conservation of the identities of the final state particles including their four - momenta , lorentz symmetry , @xmath3-parity and the conservation of total angular momentum and isospin . from this consistency alone
we find that the dephasing interaction must be a dipion spin mixing interaction .
the observed amplitudes are a unitary transform of the corresponding @xmath2-matrix amplitudes .
the elements of the spin mixing matrix are forward scattering amplitudes of dipion spin states with recoil nucleon spin states with initial and final dipion spins @xmath4 and @xmath5 , respectively .
dipion helicities are conserved in this scattering .
these amplitudes are matrix elements of kraus operators describing the non - unitary interaction with the environment .
the theory predicts @xmath6 mixing in the @xmath2-and @xmath3-wave amplitudes in @xmath7 .
the predicted moduli and relative phases of the mixed amplitudes are in an excellent qualitative agreement with the experimental results .
the mixing of @xmath2-matrix partial wave amplitudes with different dipion spins to form the observable partial wave amplitudes is a new phenomenon beyond the standard model .
the spontaneous violation of rotational / lorentz symmetry observed in the....
And you have already written the first three sentences of the full article: following the discovery in 1961 of @xmath8 meson in @xmath0 reactions , the measurements of forward - backward asymmetry in @xmath9 suggested the existence of a rho - like resonance in the @xmath2-wave amplitudes , later referred to as @xmath10 scalar meson @xcite .
the cern measurements of @xmath11 and @xmath12 on polarized targets in 1970 s cofirmed the existence of @xmath10 scalar meson .
evidence for a narrow @xmath10 was found in amplitude analyses of @xmath11 at 17.2 gev / c @xcite and in @xmath12 at 5.98 and 11.85 @xcite ..
Please generate the next two sentences of the article | additional evidence for @xmath10 came from the amplitude analysis of the itep data on @xmath7 on polarized target at 1.78 gev / c @xcite .
the @xmath2-wave amplitudes and intensities from all these analyses are surveyed in ref . |
5,688 | Suppose that you have an abstract for a scientific paper: submillimetre ( sub - mm ) galaxies have very high infrared ( ir ) luminosities and are thousands of times more numerous at @xmath0 than local ultra - luminous ir galaxies .
they therefore represent a key phase in galaxy evolution which can be missed in optical surveys .
determining their contribution to the global star formation rate requires dissecting their ir emission into contributions from starbursts ( sb ) and active galactic nuclei ( agn ) .
there are several examples of agn systems which masquerade as sbs in either the ir or x - ray , and sbs can often look like agn in some wavebands .
a combination of sb and agn emission is not unreasonable , given models of merger - driven evolution .
to assess in detail what powers the intense ir luminosity of sub - mm galaxies it is important to obtain a complete multi - wavelength picture .
mid - ir spectroscopy is a particularly good probe of where the intense ir luminosity is coming from .
we present the first results from a program to obtain _ spitzer _ irs spectroscopy of a sample of high redshift galaxies in the goods - n field , a large fraction of which are sub - mm galaxies .
this field is already home to the deepest x - ray , optical , ir and radio data .
we piece together the sub - mm data with the _ spitzer _ photometry and irs spectra to provide a well sampled ir spectral energy distribution ( sed ) of sub - mm galaxies and determine the contribution to the bolometric luminosity from the agn and sb components . .
And you have already written the first three sentences of the full article: enormous effort has gone into understanding the nature of sub - mm selected galaxies since they were first discovered with the submillimetre common user bolometer array ( scuba , holland et al .
1999 ) just under a decade ago ( e.g. smail et al . 1997 ; barger et al . 1998 ; hughes et al .
1998 ) . a general understanding of the sub - mm population and its role in galaxy evolution.
Please generate the next two sentences of the article | is severely limited by the poor spatial resolution of current sub - mm telescopes and the faintness of these sources at other wavelengths ( e.g. pope et al .
the sub - mm population appears to consist of massive objects ( borys et al . |
5,689 | Suppose that you have an abstract for a scientific paper: we consider the langevin dynamics of a gaussian test polymer chain coupled with a surrounding matrix which can undergo the glass transition . the martin - siggia - rose generating functional method and the nonpertubative hartree approximation
are used to derive the generalized rouse equation for the test chain .
it is shown that the interaction of the test chain with the surrounding matrix renormalizes the bare friction and the spring constants of the test chain in such a way that the memory function as well as the bending dependent elastic modulus appear .
we find that below the glass transition temperature @xmath0 of the matrix the rouse modes of the test chain can be frozen and moreover the freezing temperatures ( or the ergodicity - nonergodicity transition temperature ) @xmath1 depends from the rouse mode index @xmath2 .
-15 mm classification : physics abstracts , 05.20 - 36.20 .
And you have already written the first three sentences of the full article: it is wellknown that for relatively short polymer chains the standard rouse model can describe the dynamics of a melt reasonably well @xcite . on the contrary , for chain length
@xmath3 exceeding a critical length , the entanglement length @xmath4 , the behavior is usually described by the reptation model @xcite . here
we restrict ourselves to chain lengths @xmath5 , i.e. the entangled polymer dynamics will be beyond of our consideration ..
Please generate the next two sentences of the article | the reason why in a dense melt the rouse model provides so well dynamical description for short chains is connected with a screening of the long - range hydrodynamic as well as the excluded volume interactions . as a result the fluctuations of the chain variables are gaussian .
but there are further essential questions : how does the bare monomeric friction coefficient @xmath6 and the entropic elastic modulus @xmath7 ( which are simple input parameters of the standard rouse model ) change due to the interactions of the test chain and the surrounding matix ? |
5,690 | Suppose that you have an abstract for a scientific paper: within the wave - packet semiclassical approach , the bloch electron energy is derived to second order in the magnetic field and classified into gauge - invariant terms with clear physical meaning , yielding a fresh understanding of the complex behavior of orbital magnetic susceptibility .
the berry curvature and quantum metric of the bloch states give rise to a geometrical magnetic susceptibility , which can be dominant when bands are filled up to a small energy gap .
there is also an energy polarization term , which can compete with the peierls - landau and pauli magnetism on a fermi surface .
all these , and an additional langevin susceptibility , can be calculated from each single band , leaving the van vleck susceptibility as the only term truly from interband coupling . .
And you have already written the first three sentences of the full article: the intrinsic geometrical properties of the bloch band is of great importance in solid state physics . to zeroth order in electromagnetic fields ,
the effective mass tensor reflects the curvature of band dispersions , which describes the low energy behaviour near band extrema and enters into the carrier density of states and various transport properties.@xcite to first order , an accurate description of bloch electron dynamics not only requires the knowledge of the band dispersion , but also the berry curvature and the orbital magnetic moment as functions of the crystal momentum.@xcite the berry curvature reflects the intrinsic geometry of the bloch state fiber bundle , and its importance has been exemplified in the study of anomalous hall effects of charge and heat and in the investigation of orbital magnetization.@xcite how does the intrinsic geometry of bloch bands affect the second order response to electromagnetic fields ?
are there additional geometrical quantities emerge in the orbital magnetic susceptibility ? in this work , we present an exhaustive analysis of the electron wave - packet energy and orbital magnetic susceptibility by making a gauge invariant classification ..
Please generate the next two sentences of the article | we are able to identify a geometrical contributions from the fermi sea , which we call the geometrical susceptibility , in the sense that it involves geometrical quantities including the berry curvature and the quantum metric .
the geometrical susceptibility is a novel mechanism for orbital magnetic susceptibility , which provides the dominant diamagnetic response around the band gaps , and is especially important in strongly spin / pseudospin - orbit coupled systems such as topological insulators and 2d semimetals . |
5,691 | Suppose that you have an abstract for a scientific paper: the results of a new search for positronium decays into invisible final states are reported .
convincing detection of this decay mode would be a strong evidence for new physics beyond the standard model ( sm ) : for example the existence of extra dimensions , of milli - charged particles , of new light gauge bosons or of mirror particles .
mirror matter could be a relevant dark matter candidate . in this paper the setup and
the results of a new experiment are presented . in a collected sample of about @xmath0
orthopositronium decays , no evidence for invisible decays in an energy window [ 0,80 ] kev was found and an upper limit on the branching ratio of orthopositronium @xmath1 could be set : @xmath2 our results provide a limit on the photon mirror - photon mixing strength @xmath3 and rule out particles lighter than the electron mass with a fraction @xmath4 of the electron charge .
furthermore , upper limits on the branching ratios for the decay of parapositronium @xmath5 and the direct annihilation @xmath6 could be set .
positronium decay , new physics , extradimension , hidden sector .
And you have already written the first three sentences of the full article: although direct manifestations of new physics are searched for at the high energy frontier , new phenomena can also be looked for at low energies via precision measurements .
the new effects might be observed in rare decays of the positronium ( see e.g. @xcite ) .
positronium ( ps ) , the positron - electron bound state , is the lightest known atom , which at the current level of experimental and theoretical precision is bound and self - annihilates through the electromagnetic interaction @xcite ..
Please generate the next two sentences of the article | this feature has made positronium an ideal system for testing the accuracy of quantum electrodynamics ( qed ) calculations for bound states , in particular for the triplet ( @xmath7 ) state of @xmath8 ( orthopositronium , @xmath9 ) @xcite .
due to the odd - parity under c - transformation @xmath9 decays predominantly into three photons with a lifetime in vacuum of @xmath10 ns @xcite-@xcite . |
5,692 | Suppose that you have an abstract for a scientific paper: we use a result on mixed tate motives due to goncharov @xcite to show that the symbol of an arbitrary one - loop @xmath0-gon integral in @xmath0 dimensions may be read off directly from its feynman parameterization .
the algorithm proceeds via recursion in @xmath1 seeded by the well - known box integrals in four dimensions . as a simple application of this method we write down the symbol of a three - mass hexagon integral in six dimensions .
brown - het-1612 nsf - kitp-11 - 076 1 cm .
And you have already written the first three sentences of the full article: recent breathtaking advances in our understanding of the mathematical structure of scattering amplitudes in maximally supersymmetric yang - mills theory ( sym ) have so far had the most dramatic impact on tree - level amplitudes or quantities ( such as leading singularities or the planar integrand @xcite ) which are completely determined in terms of tree - level data .
the guiding principle behind these advances is the observation that amplitudes exhibit simplicity which is completely obscured by their traditional feynman diagram expansions .
in contrast the problem of actually evaluating the integrals which appear in multi - loop amplitudes remains extremely difficult in general ( see @xcite for an introduction to modern methods ) ..
Please generate the next two sentences of the article | however data is starting to accumulate which suggests that the final results for amplitudes ( or even individual integrals ) can again be far simpler than one might have guessed on the basis of results obtained from more traditional integration approaches , such as mellin - barnes techniques .
in @xcite goncharov , vergu and the authors introduced to the sym literature a powerful mathematical tool first developed in @xcite , called the symbol of a transcendental function , for analyzing functions of the type which appear in all currently known sym loop amplitudes . |
5,693 | Suppose that you have an abstract for a scientific paper: we analyze an interferometric complementarity between one- and two - particle interference in the general case : @xmath0 @xmath1 , @xmath2 , and further examine the relation among one - particle interference visibility @xmath3 , two - particle interference visibility @xmath4 and the predication @xmath5 of the path of a single particle .
an equality @xmath6 @xmath1 , @xmath2 is achieved for any pure two - particle source , which implies the condition of the complementarity relation to reach the upper bound and its relation to another interferometric complementarity between path information and interference visibility of a single particle .
meanwhile , the relationships of the complementarities and the entanglement @xmath7 of the composite system are also investigated .
using nuclear magnetic resonance techniques , the two - particle interferometric complementarity was experimentally tested with the ensemble - averaged spin states , including two extreme cases and an intermediate case . .
And you have already written the first three sentences of the full article: quantum superposition and its resulting interference are arguably the most fundamental effects in quantum mechanics , which leads to the concept of complementarity . in 1927 , bohr@xcite first reviewed this subject , claimed that the wave- and particle - like behaviors of a quantum mechanical object are mutually exclusive in a single experiment and expressed it as complementarity .
so bohr complementarity is often superficially identified with the ` wave - particle duality'@xcite which emphasizes two extreme cases that each experiment must be described in terms of either waves or particles , as explained in the textbook .
theoretical investigations about the intermediate situations in which particle and wave aspects coexist have led to some quantitative statements about wave - particle duality@xcite , some of which are expressed as inequalities @xmath8 or @xmath9 about the complementarity between ` which - way ' ( ww ) information of a particle : the predictability @xmath10 and the distinguishability @xmath11 of the path , and the visibility @xmath12 of interference fringes@xcite ..
Please generate the next two sentences of the article | bohr complementarity is often illustrated by means of interferometers and has been experimentally investigated in one - particle interferometer with individual particles , including photons@xcite , electrons@xcite , neutrons@xcite , atoms@xcite and nuclear spins in a bulk ensemble with nuclear magnetic resonance ( nmr ) techniques@xcite .
complementarity , however , is a more general concept which states that quantum systems possess properties that are equally real but mutually exclusive . |
5,694 | Suppose that you have an abstract for a scientific paper: a binary lattice gas model that allows for multiple occupancy of lattice sites , inspired by recent coarse - grained descriptions of solutions of interacting polymers , is investigated by combining the steepest descent approximation with an exploration of the multidimensional energy landscape , and by gibbs ensemble monte carlo simulations . the one - component version of the model , involving on site and nearest neighbour interactions , is shown to exhibit microphase separation into two sub - lattices with different mean occupation numbers . the symmetric two - component version of the multiple occupancy lattice gas is shown to exhibit a demixing transition into two phases above a critical mean occupation number . .
And you have already written the first three sentences of the full article: simple fluids are dominated by excluded volume effects , which , within lattice gas models , are accounted for by the single occupancy constraint , whereby each site on a lattice can be occupied by at most one molecule .
effective interactions between macromolecules or self - assembled aggregates in complex fluids , on the other hand , can be `` soft '' , i.e. lack an impenetrable core . a good example is the effective pair potential between the centres of mass ( cm ) of interacting polymer coils , obtained by taking statistical averages over monomer conformations for fixed distances @xmath0 between the cms @xcite .
recent extensive simulations of self - avoiding walk polymers carried out over a wide range of concentrations show that the repulsive state - dependent effective cm pair potential is of roughly gaussian shape , of width governed by the polymer radius of gyration , and of maximum amplitude @xmath1 @xcite ; this behaviour reflects the fractal nature of polymers in good solvent , leading to a low entropic cost at full overlap ..
Please generate the next two sentences of the article | several other complex fluids have been shown to exhibit ultrasoft coarse - grained interactions , e. g. star polymers @xcite or effective particles considered within dissipative particle dynamics @xcite .
the penetrability of the corresponding `` gaussian core '' ( gc ) model , @xmath2 , leads to interesting phase behaviour at low temperatures ( @xmath3 ) , @xcite , but under conditions relevant for polymer solutions ( @xmath4 ) , the model behaves like a `` mean field '' fluid @xcite . |
5,695 | Suppose that you have an abstract for a scientific paper: one of the long standing challenges in molecular simulation is the description of interfaces . on the molecular length scale
, finite size effects significantly influence the properties of the interface such as its interfacial tension , which can be reliably investigated by molecular dynamics simulation of planar vapor - liquid interfaces . for the lennard - jones fluid ,
finite size effects are examined here by varying the thickness of the liquid slab .
it is found that the surface tension and density in the center of the liquid region decreases significantly for thin slabs .
the influence of the slab thickness on both the liquid density and the surface tension is found to scale with 1/@xmath0 in terms of the slab thickness @xmath1 , and a linear correlation between both effects is obtained .
the results corroborate the analysis of malijevsk and jackson , j. phys .
: cond . mat .
24 : 464121 ( 2012 ) , who recently detected an analogous effect for the surface tension of liquid nanodroplets .
surface tension , long range correction , finite size effects .
And you have already written the first three sentences of the full article: molecular simulation is a well - established approach for the analysis of fluid interfaces and their molecular structure .
much work has been dedicated to the interfacial tension.@xcitefor a fluid interface , there are ( at least ) three different aspects in which its size can be varied , each of which may affect the interfacial tension : * curvature effects , depending on the local characteristic radii of curvature * capillary wave effects , depending on the range of wavelengths permitted by the morphology and size of the interface * confinement effects , which arise due to spatial restrictions imposed on a fluid phase by one or several interfaces or walls according to the tolman @xcite approach , the interfacial tension of a nanodroplet deviates from that of a planar interface due to its extremely curved shape.@xcite however , it should be noted that all three phenomena are present when the size of a droplet is varied : smaller droplets have a higher curvature , a smaller range of capillary wavelengths , and a more significant deviation from bulk - like behaviour due to confinement .
in addition to curvature , the other effects might therefore also have a significant influence on the formation of droplets in a supersaturated vapor , where the size of the critical nucleus and the nucleation rate are of major interest.@xcite a similar case is cavitation , where bubbles emerge in a liquid phase.@xcite on the employed cutoff radius @xmath2 , for the truncated and shifted lj potential without long - range effects ( ljts ) and for the full lj potential with a long - range correction ( lrc ) according to janeek.@xcite the simulations were carried out in the canonical ensemble with @xmath3 = 2 048 particles at @xmath4 = 0.7 using a simulation box with an elongation of @xmath5 = 66 in the direction perpendicular to the vapor - liquid interfaces.,width=293 ] spherically curved interfaces of droplets were simulated for the first time by molecular simulation in the early 1970s.@xcite nonetheless ,....
Please generate the next two sentences of the article | several previous works address the influence of small simulation volumes,@xcite which is usually discussed in terms of capillary wave effects.@xcite the present study considers the influence of the liquid slab thickness , i.e. of confinement by two parallel planar vapor - liquid interfaces which are close to each other .
this effect was previously investigated by weng et al . |
5,696 | Suppose that you have an abstract for a scientific paper: we describe the conditional and unconditional dynamics of two coupled quantum dots when one dot is subjected to a measurement of its occupation number using a single electron transistor ( set ) .
the measurement is made when the bare tunneling rate though the set is changed by the occupation number of one of the dots .
we show that there is a difference between the time scale for the measurement - induced decoherence between the localized states of the dots and the time scale on which the system becomes localized due to the measurement .
a comparison between theory and current experiments is made . .
And you have already written the first three sentences of the full article: there have recently been a number of suggestions for a quantum computer architecture that use quantum dots of varying kinds@xcite .
if these schemes are to be practical many important physical questions need to be answered , one of which is how to readout physical properties such as charge or spin at a single electron level@xcite . in this paper
we present a quantum trajectory analysis of a general scheme to readout a single electronic qubit using a single electron transistor ( set ) ..
Please generate the next two sentences of the article | we adopt a general phenomenological description of the set in which the tunneling rate through the set is conditioned on the occupation or otherwise of a nearby quantum dot .
we consider two spatially separated quantum dots which are strongly coupled so that delocalized states of their relevant degrees of freedom can form . to be specific |
5,697 | Suppose that you have an abstract for a scientific paper: in this paper we introduce a new approach for approximately counting in bounded degree systems with higher - order constraints .
our main result is an algorithm to approximately count the number of solutions to a cnf formula @xmath0 with at least @xmath1 variables per clause and degree at most @xmath2 when @xmath1 is logarithmic in @xmath2 .
this closes an exponential gap between the known upper and lower bounds .
moreover our algorithm extends straightforwardly to approximate sampling , which shows that under lovsz local lemma - like conditions it is not only possible to find a satisfying assignment , it is also possible to generate one approximately uniformly at random from the set of all satisfying assignments .
our approach is a significant departure from earlier techniques in approximate counting , and is based on a framework to bootstrap an oracle for computing marginal probabilities on individual variables .
finally , we give an application of our results to show that it is algorithmically possible to sample from the posterior distribution in an interesting class of graphical models . .
And you have already written the first three sentences of the full article: in this paper we introduce a new approach for approximately counting in bounded degree systems with higher - order constraints .
for example , if we are given a cnf formula @xmath0 with @xmath3 variables and @xmath4 clauses with the property that each clause contains at least @xmath1 variables and each variable belongs to at most @xmath2 clauses we ask : how does @xmath1 need to relate to @xmath2 for there to be algorithms to estimate the number of satisfying assignments to @xmath0 within a @xmath5 multiplicative factor ? in the case of a monotone cnf formula where no variable appears negated , the problem is equivalent to the following : suppose we are given a hypergraph on @xmath3 nodes and @xmath4 hyperedges with the property that each hyperedge contains at least @xmath1 nodes and each node belongs to at most @xmath2 hyper edges . how does @xmath1 need to relate to @xmath2 in order to be able to approximately compute the number of independent sets . here
an independent set is a subset of nodes for which there is no induced hyperedge ..
Please generate the next two sentences of the article | bordewich , dyer and karpinski @xcite gave an mcmc algorithm for approximating the number of hypergraph independent sets ( equivalently , the number of satisfying assignments in a monotone cnf formula ) that succeeds whenever @xmath6 .
bezakova et al . |
5,698 | Suppose that you have an abstract for a scientific paper: the relativistic faddeev equation for three - nucleon scattering is formulated in momentum space and directly solved in terms of momentum vectors without employing a partial wave decomposition .
the equation is solved through pad summation , and the numerical feasibility and stability of the solution is demonstrated .
relativistic invariance is achieved by constructing a dynamical unitary representation of the poincar group on the three - nucleon hilbert space .
based on a malfliet - tjon type interaction , observables for elastic and break - up scattering are calculated for projectile energies in the intermediate energy range up to 2 gev , and compared to their nonrelativistic counterparts .
the convergence of the multiple scattering series is investigated as a function of the projectile energy in different scattering observables and configurations .
approximations to the two - body interaction embedded in the three - particle space are compared to the exact treatment . .
And you have already written the first three sentences of the full article: the lightest nuclei can be accurately modeled as systems of nucleons interacting via effective two- and three - body forces motivated e.g. by meson exchange .
this picture is expected to break down at a higher energy scale , where the physics is more efficiently described in terms of subnuclear degrees of freedom .
few - body methods have been an essential tool for determining model hamiltonians that describe low - energy nuclear physics ..
Please generate the next two sentences of the article | they also have the potential to be a useful framework for testing the limitations of viewing the nucleus as a few nucleon system .
the latter requires extending few - body models and calculations to higher energies . in order to successfully do this , |
5,699 | Suppose that you have an abstract for a scientific paper: a natural extension of bipartite graphs are @xmath0-partite clutters , where @xmath1 is an integer . for a poset @xmath2 ,
ene , herzog and mohammadi introduced the @xmath0-partite clutter @xmath3 of multichains of length @xmath0 in @xmath2 , showing that it is cohen - macaulay .
we prove that the cover ideal of @xmath3 admits an @xmath4-splitting , determining a recursive formula for its betti numbers and generalizing a result of francisco , h and van tuyl on the cover ideal of cohen - macaulay bipartite graphs .
moreover we prove a betti splitting result for the alexander dual of a cohen - macaulay simplicial complex .
* keywords * : resolution of edge ideals , cohen - macaulay clutters , betti splittings , posets .
+ _ ams mathematics subject classification 2010 _ : 13d02 , 13a02 , 05e40 , 05e45 . .
And you have already written the first three sentences of the full article: edge ideals of graphs have been extensively studied by several authors ( see for instance @xcite , @xcite , @xcite , @xcite , @xcite ) . in recent years the interest focused on a generalization of the notion of graph , the so - called _ clutter _ ( see @xcite , @xcite , @xcite , @xcite , @xcite , @xcite ) .
edge ideals have been introduced by villarreal in @xcite .
let @xmath5 be a field and @xmath6 a finite simple graph on @xmath7 vertices ..
Please generate the next two sentences of the article | the edge ideal of @xmath6 is @xmath8.\ ] ] a graph @xmath6 is called cohen - macaulay if @xmath9 is cohen - macaulay .
similarly it is possible to define the edge ideal @xmath10 of a clutter @xmath11 . |
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