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7,800 | Suppose that you have an abstract for a scientific paper: using sdss data release 6 , we construct two independent samples of candidate stellar wide binaries selected as i ) pairs of unresolved sources with angular separation in the range @xmath0 , ii ) common proper motion pairs with @xmath1 angular separation , and make them publicly available . these samples are dominated by disk stars , and we use them to constrain the shape of the main - sequence photometric parallax relation @xmath2 , and to study the properties of wide binary systems .
we estimate @xmath2 by searching for a relation that minimizes the difference between distance moduli of primary and secondary components of wide binary candidates .
we model @xmath2 by a fourth degree polynomial and determine the coefficients using markov chain monte carlo fitting , independently for each sample .
both samples yield similar relations , with the largest systematic difference of 0.25 mag for f0 to m5 stars , and a root - mean - square scatter of 0.13 mag . a similar level of agreement is obtained with photometric parallax relations recently proposed by @xcite .
the measurements show a root - mean - square scatter of @xmath3 mag around the best fit @xmath2 relation , and a mildly non - gaussian distribution .
we attribute this scatter to metallicity effects and additional unresolved multiplicity of wide binary components .
aided by the derived photometric parallax relation , we construct a series of high - quality catalogs of candidate main - sequence binary stars .
these range from a sample of @xmath4 candidates with the probability of each pair to be a physical binary ( the `` efficiency '' ) of @xmath5 , to a volume - limited sample of @xmath6 candidates with an efficiency of @xmath7 . using these catalogs
, we study the distribution of semi - major axes of wide binaries , @xmath8 , in the @xmath9 au range . we find the observations to be well described by the pik distribution , @xmath10 , for @xmath11 , where @xmath12 increases roughly linearly with the height @xmath13 above the galactic....
And you have already written the first three sentences of the full article: binary systems can be roughly divided into close ( semi - major axes @xmath18 au ) and wide ( semi - major axes @xmath19 au , @xcite ) pairs .
close binary systems have long been recognized as useful tools for studies of stellar properties .
for example , the stellar parameters such as the masses and radii of individual stars are readily determined to high confidence using eclipsing binaries @xcite ..
Please generate the next two sentences of the article | wide binary systems have proven to be a tool for studies of star formation processes , as well as an exceptionally useful tracer of local potential and tidal fields through which they traverse .
specifically , they were used to place the constraints on the nature of halo dark matter @xcite and to explore the dynamical history of the galaxy @xcite . |
7,801 | Suppose that you have an abstract for a scientific paper: the case of @xmath0-ray absorption due to photon - photon pair production of jet photons in the external photon environment like accretion disk and broad - line region radiation field of @xmath0-ray loud active galactic nuclei ( agn ) that exhibit strong emission lines is considered .
i demonstrate that this local opacity , if detected , will almost unavoidably be redshift - dependent in the sub - tev range .
this introduces non - negligible biases , and complicates approaches for studying the evolution of the extragalactic background light with contemporary gev instruments like e.g. the gamma - ray large area space telescope ( glast ) , etc . , where the @xmath0-ray horizon is probed by means of statistical analysis of absorption features ( e.g. fazio - stecker relation , etc .
) in agn spectra at various redshifts .
it particularly applies to strong - line quasars where external photon fields are potentially involved in @xmath0-ray production . .
And you have already written the first three sentences of the full article: following the unification scheme the central nucleus of an active galaxy ( agn ) consists of a black hole ( bh ) , an accretion disk , line - emitting clouds , a dust torus , and emanates prominent jets when classified as radio - loud .
the properties of radio - loud agn viewed at a small angle to the line - of - sight are in general agreement with the common blazar properties ( e.g. , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | their broadband emission covers the complete electromagnetic band , from the radio up to the @xmath0-ray band , in some cases even reaching tev - energies , and is widely dominated by beamed non - thermal emission from a relativistic jet .
the blazar class subdivides into bl lac objects and flat - spectrum radio quasars ( fsrqs ) . |
7,802 | Suppose that you have an abstract for a scientific paper: we use a @xmath0 sample of @xmath1 star - forming galaxies from the fourth data release of the sloan digital sky survey to investigate the dependence of gas - phase chemical properties on stellar mass and environment .
the local density , determined from the projected distances to the fourth and fifth nearest neighbours , is used as an environment indicator .
considering environments ranging from voids , i.e. , @xmath2 , to the periphery of galaxy clusters , i.e. , @xmath3 , we find no dependence of the relationship between galaxy stellar mass and gas - phase oxygen abundance , along with its associated scatter , on local galaxy density .
however , the star - forming gas in galaxies shows a marginal increase in the chemical enrichment level at a fixed stellar mass in denser environments .
compared with galaxies of similar stellar mass in low density environments , they are enhanced by a few per cent for massive galaxies to about 20 per cent for galaxies with stellar masses @xmath4 .
these results imply that the evolution of star - forming galaxies is driven primarily by their intrinsic properties and is largely independent of their environment over a large range of local galaxy density .
[ firstpage ] galaxies : evolution galaxies : abundances galaxies : fundamental parameters galaxies : clusters : general .
And you have already written the first three sentences of the full article: one of the central problems in astronomy is that of galaxy formation and evolution : when were the various parts of galaxies assembled , when were the stars formed , and how did these processes depend on environment ? at low redshift the dependence of many galaxy properties on environment is well established .
dense environments contain a larger fraction of red , passive galaxies , while low density environments contain more blue , star - forming galaxies ( e.g. , @xcite ) .
the distributions of colour and h@xmath5 equivalent width , and hence inferred star - formation histories , are found to be bimodal @xcite . surprisingly , the two sequences vary little with environment , except in terms of their relative proportions @xcite ..
Please generate the next two sentences of the article | however , some studies find that star - forming galaxies in clusters tend to have a reduced global star formation rate with respect to field galaxies of the same morphological type @xcite .
the chemical abundances of stars and interstellar gas within galaxies provide a fundamental tool for tracing the evolution of their stellar and metal content . |
7,803 | Suppose that you have an abstract for a scientific paper: non - interacting particles with long - range hopping are known to be delocalized in disordered systems of infinite size .
it is thus natural to assume that such particles can traverse any finite - size lattice . here
, we demonstrate that this is not generally true .
the delocalization mechanism is induced by resonances between distant lattice sites .
the number of such resonances diverges with the system size . for a finite - size lattice
the number of resonances is finite and may not be sufficient to result in delocalization .
we consider particles with long - range ( dipolar ) hopping in three - dimensional lattices with diagonal disorder and random dilution .
we compute the wavepacket dynamics of particles placed in an individual lattice site , the inverse participation ratios and the fluctuations of the wavefunctions with disorder .
we show that , for certain finite - size disordered lattices , particles remain localized within a finite volume much smaller than the lattice size , and that the wavefunctions exhibit the log - normal fluctuations characteristic of anderson localization .
we characterize the localization properties as functions of dilution and diagonal disorder .
we combine our results with scaling theory to obtain the size dependence of the localization diffusion crossover .
our results indicate that particles with long - range hopping undergo exponential localization in lattices of finite size , even macroscopically finite .
our phase diagrams illustrate a rather unusual phenomenon : quantum particles can diffuse through a lattice of size @xmath0 , but not through a lattice of size @xmath1 . .
And you have already written the first three sentences of the full article: a quantum particle in a three - dimensional disordered lattice is either localized or diffusive ; this depends on the strength of the disorder @xcite .
if the particles are localized within a finite localization length @xmath2 , one observes current over length scales @xmath3 , while no conductivity over length scales @xmath4 @xcite .
if quantum transport is allowed over infinite length scales , particles are naturally assumed to diffuse over any arbitrary length scale . as was pointed out already in the original work of anderson @xcite , quantum particles with long - range hopping are diffusive in three - dimensional ( 3d ) lattices of infinite size , for any disorder strength ..
Please generate the next two sentences of the article | this absence of localization was later explained by levitov @xcite , who showed that diffusion occurs due to resonant transitions between distant lattice sites .
the number of such resonances diverges with the lattice size , leading to particle transport over infinite length scales . |
7,804 | Suppose that you have an abstract for a scientific paper: this correspondence studies the downlink transmission in a multi - cell system , where multiple base stations ( bss ) each with multiple antennas cooperatively design their respective transmit beamforming vectors to optimize the overall system performance . for simplicity
, it is assumed that all mobile stations ( mss ) are equipped with a single antenna each , and there is one active ms in each cell at one time .
accordingly , the system of interests can be modeled by a multiple - input single - output ( miso ) interference channel ( ic ) , termed as miso - ic , with interference treated as noise .
we propose a new method to characterize different rate - tuples for active mss on the pareto boundary of the achievable rate region for the miso - ic , by exploring the relationship between the miso - ic and the cognitive radio ( cr ) miso channel .
we show that each pareto - boundary rate - tuple of the miso - ic can be achieved in a decentralized manner when each of the bss attains its own channel capacity subject to a certain set of interference - power constraints ( also known as interference - temperature constraints in the cr system ) at the other ms receivers .
furthermore , we show that this result leads to a new decentralized algorithm for implementing the multi - cell cooperative downlink beamforming .
beamforming , cooperative multi - cell system , interference channel , multi - antenna , pareto optimal , rate region . [ section ] [ section ] [ section ] [ section ] [ section ] [ section ] .
And you have already written the first three sentences of the full article: conventional wireless mobile networks are designed with a cellular architecture , where base stations ( bss ) from different cells control communications for their associated mobile stations ( mss ) independently .
the resulting inter - cell interference is treated as additive noise and minimized by applying a predesigned frequency reuse pattern such that the same frequency band is reused only by non - adjacent cells . due to the rapidly growing demand for high - rate wireless multimedia applications ,
conventional cellular networks have been pushed towards their throughput limits ..
Please generate the next two sentences of the article | consequently , many beyond-3 g wireless technologies such as wimax and 3gpp umts long term evolution ( lte ) have relaxed the constraint on the frequency reuse such that the total frequency band becomes available for reuse by all cells .
however , this factor - one frequency reuse pattern renders the overall network performance limited by the inter - cell interference ; consequently , more sophisticated interference management techniques with multi - cell cooperation become crucial . among others , one effective method to cope with the inter - cell interference in the cellular network is via joint signal processing across different bss . in this correspondence |
7,805 | Suppose that you have an abstract for a scientific paper: we study numerically the motion of a one dimensional array of brownian particles in a washboard potential , driven by an external stochastic force and interacting via short range repulsive forces .
in particular , we investigate the role of instantaneous elastic and inelastic collisions on the system dynamics and transport .
the system displays a locked regime , where particles may move only via activated processes and a running regime where particles drift along the direction of the applied field . by tuning the value of the friction parameter controlling the brownian motion we explore both the overdamped dynamics and the underdamped dynamics . in the two regimes we considered the mobility and the diffusivity of the system as functions of the tilt and other relevant control parameters such as , coefficient of restitution , particle size and total number of particles .
we find that , while in the overdamped regime , the results for the interacting systems present similarities with the known non - interacting case , in the underdamped regime , the inelastic collisions determine a rich variety of behaviors among which is an unexpected enhancement of the inelastic diffusion . .
And you have already written the first three sentences of the full article: a large class of phenomena in biology , chemistry , engineering and physics occurs via the transport of particles driven along periodic substrates by an external bias .
these phenomena include polymer diffusion at interfaces @xcite , motion of fluxons in superconductors containing a periodic arrangement of defects @xcite , adsorption on crystal surfaces @xcite , super - ionic conduction @xcite , motion of molecular motors along microtubules @xcite , granular flows on rough inclined substrates @xcite or in a narrow pipe @xcite .
the study of transport properties of granular systems represents an open issue in statistical mechanics of considerable interest and difficulty in view of the continuous energy dissipation caused by particle inelastic interactions @xcite . in this perspective.
Please generate the next two sentences of the article | , we consider a simple model consisting of a granular fluid moving on a tilted rough substrate , which may favor clustering and jamming behaviors . in our formulation , a granular system is a large number of particles ( grains ) colliding with one another and losing a little energy in each collision @xcite .
if such a system is shaken to keep it in motion its dynamics resembles that of fluids as the grains move randomly . |
7,806 | Suppose that you have an abstract for a scientific paper: we investigate the evolution of a zeeman coherence grating induced in a cold atomic cesium sample in the presence of an external magnetic field .
the gratings are created in a three - beam light storage configuration using two quasi - collinear writing laser pulses and reading with a counterpropagating pulse after a variable time delay .
the phase conjugated pulse arising from the atomic sample is monitored .
collapses and revivals of the retrieved pulse are observed for different polarizations of the laser beams and for different directions of the applied magnetic field . while magnetic field inhomogeneities are responsible for the decay of the coherent atomic response , a five - fold increase in the coherence decay time , with respect to no applied magnetic field ,
is obtained for an appropriate choice of the direction of the applied magnetic field .
a simplified theoretical model illustrates the role of the magnetic field mean and its inhomogeneity on the collective atomic response . .
And you have already written the first three sentences of the full article: the mapping of optical information into an atomic ensemble , a phenomenon usually named light storage ( ls ) , plays a fundamental role for both classical and quantum information processing @xcite . to date several observations of ls have been reported both in thermal and in cold atomic systems @xcite .
long storage times as well as the possibility of controlling and manipulating the stored information @xcite , is of essential importance for the realization of any practical quantum protocol . in most of the experimental observations of ls ,
ground state hyperfine levels of alkali atoms are employed to store the optical information into zeeman coherences ..
Please generate the next two sentences of the article | these coherences may be conveniently manipulated by external magnetic fields @xcite .
however , they are also very sensitive to stray magnetic fields gradients , which can strongly reduce the coherence time of the system @xcite . collapses and revivals due to larmor precession of zeeman coherence associated with different hyperfine ground states of rubidium atoms |
7,807 | Suppose that you have an abstract for a scientific paper: electron transport phenomena in disordered electron systems with spin - orbit coupling in two dimensions and below are studied numerically .
the scaling hypothesis is checked by analyzing the scaling of the quasi-1d localization length .
a logarithmic increase of the mean conductance is also confirmed .
these support the theoretical prediction that the two dimensional metal in systems with spin - orbit coupling has a perfect conductivity .
transport through a sierpinski carpet is also reported . , , quantum transport , spin - orbit coupling , symplectic class , scaling theory , perfect conductivity .
And you have already written the first three sentences of the full article: research in spintronics and carbon nanotubes sparked renewed interests in the effects of spin - orbit coupling on quantum transport @xcite .
one of the remarkable features of non - interacting disordered electron systems with spin - orbit coupling is the existence of a metallic phase in two dimensions ( 2d ) @xcite .
more exactly the 2d metallic phase appears in systems with symplectic symmetry , i.e. , in systems with time reversal symmetry but without spin rotation symmetry ..
Please generate the next two sentences of the article | such systems are an exception to the prediction of abrahams _ et al . _ that there is no metallic phase in 2d disordered electron systems @xcite .
recently some 2d metals have been discovered experimentally @xcite . |
7,808 | Suppose that you have an abstract for a scientific paper: we study the properties of very faint , sub-@xmath0 lyman break galaxies at @xmath1@xmath225 thus far a largely neglected but numerically and energetically very important population . we find that the lbg luminosity function undergoes luminosity - dependent evolution : the number of luminous galaxies remains constant while the number of faint ones grows with time .
the total uv luminosity density increases with cosmic time from at least @xmath1@xmath25 until reaching a peak or a plateau around @xmath1@xmath22 behaviour that is governed by the sub-@xmath0 galaxies in the lf s `` faint tail '' . using broadband
sed fitting we find a nearly - linear relationship between sfr and galaxy stellar mass at @xmath1@xmath22 .
a typical @xmath0 lbg at @xmath1@xmath22 shows a stellar mass of @xmath210@xmath3@xmath4 , remarkably similar to the bimodality mass at low redshift .
this similarity suggests that the mechanisms responsible for the galaxy bimodality at low-@xmath1 may have also been at play at @xmath1@xmath22 . .
And you have already written the first three sentences of the full article: until very recently , studies of @xmath1@xmath51 galaxies have focused primarily on luminous , vigorously star - forming objects such as submillimetre sources or @xmath6@xmath2@xmath0 lbgs that are forming stars at rates of 10s or 100s @xmath4/yr .
such studies have largely neglected the less glamorous but far more numerous faint , sub-@xmath0 galaxies that are forming stars at much lower rates .
although individually faint , these sub-@xmath0 objects are very numerous and so collectively they generate more than half the total uv luminosity density of the universe at high redshift ..
Please generate the next two sentences of the article | they are , thus , extremely important contributors to the story of star formation and metal enrichment in the early universe .
moreover , the presence of a break at @xmath0 in the galaxy lf suggests that galaxies below @xmath0 differ substantially from those above it . because of this , our understanding of the mechanisms that drive galaxy evolution at high redshift may profit from comparing the properties of the better - studied luminous ( @xmath6 @xmath7 @xmath0 ) objects with those of the neglected sub-@xmath0 galaxies . this paper summarizes the results of our recent work aimed at understanding these hitherto neglected , individually modest but collectively very important objects . |
7,809 | Suppose that you have an abstract for a scientific paper: the ultraluminous x - ray source ( ulx ) , ngc 5408 x-1 , is one of only 3 such objects to show a quasi - periodic oscillation ( qpo ) in its power spectrum .
previous analysis of this signal identified it with the well - studied type c low - frequency qpo ( lfqpo ) seen in black hole binaries ( bhbs ) , implying an intermediate mass black hole ( imbh ) .
however , in bhbs this qpo has a centroid frequency which scales tightly with the position of the low - frequency break in the broad band power spectrum .
we use this relation to predict the frequency of the power spectral break in ngc 5408 x-1 , and show that this is inconsistent with the break frequencies in both available , archival _ xmm - newton _ observations .
thus the broad band power spectral shape does not support this identification of the qpo .
the energy spectra also do not support an imbh interpretation .
they can be fit by a two - component model , best described by soft thermal emission at low energies , together with low - temperature , optically thick comptonisation producing a tail which dominates above 2 kev .
the parameters of the tail are unlike those seen in any of the sub - eddington bhb spectral states .
the energy dependent variability supports this deconvolution , as it is consistent with the soft thermal component below 2 kev diluting extreme variability of the high energy tail .
the only objects with similar spectra which have similar amounts of variability are the bhb , grs 1915 + 105 , and some extreme nls1s .
this suggests that ngc 5408 x-1 is in a similar super - eddington state , placing a natural limit on the mass of @xmath0 100m@xmath1 .
its qpo could then be similar to the ultra - lfqpo seen occasionally in grs 1915 + 105 , consistent with a large stellar mass black hole .
we suggest a model geometry which may explain the spectra and variability of highly super - eddington sources .
= -0.5 cm [ firstpage ] accretion : accretion discs black hole physics
x - rays : binaries x -....
And you have already written the first three sentences of the full article: extragalactic x - ray sources with luminosities in excess of 10@xmath2 erg s@xmath3 have now been widely detected in the nearby universe ( fabbiano 1989 ; miller & colbert 2004 ; roberts 2007 ) .
these are designated as ultraluminous x - ray sources ( ulxs ) if they are not coincident with the nucleus of their host galaxy ( i.e. an agn ) nor correspond to a foreground or background object , e.g. a qso .
they are too luminous to be powered by a sub - eddington accretion flow in a stellar - mass black hole binary ( bhb ) unless substantial beaming of their emission is invoked ( king et al ..
Please generate the next two sentences of the article | 2001 ) , so either require super - eddington mass accretion onto a stellar mass black hole , or sub - eddington accretion onto an intermediate mass black hole ( imbh ; see colbert & mushotzky 1999 ) .
unambiguously distinguishing between these possibilities requires radial velocity measurements of the underlying binary motion to directly determine the mass ( see e.g. charles & coe 2006 ) . |
7,810 | Suppose that you have an abstract for a scientific paper: complexes of physically interacting proteins are one of the fundamental functional units responsible for driving key biological mechanisms within the cell .
their identification is therefore necessary not only to understand complex formation but also the higher level organization of the cell . with the advent of high - throughput " techniques in molecular biology , significant amount of physical interaction data has been catalogued from organisms such as yeast , which has in turn fueled computational approaches to systematically mine complexes from the network of physical interactions among proteins ( ppi network ) . in this survey , we review , classify and evaluate some of the key computational methods developed till date for the identification of protein complexes from ppi networks .
we present two insightful taxonomies that reflect how these methods have evolved over the years towards improving automated complex prediction .
we also discuss some open challenges facing accurate reconstruction of complexes , the crucial ones being presence of high proportion of errors and noise in current high - throughput datasets and some key aspects overlooked by current complex detection methods .
we hope this review will not only help to condense the history of computational complex detection for easy reference , but also provide valuable insights to drive further research in this area . .
And you have already written the first three sentences of the full article: most biological processes within the cell are carried out by proteins that physically _ interact _ to form stoichiometrically stable _
complexes_. even in the relatively simple model organism _ saccharomyces cerevisiae _ ( budding yeast ) , these complexes are comprised of many subunits that work in a coherent fashion .
these complexes interact with individual proteins or other complexes to form functional modules and pathways that drive the cellular machinery ..
Please generate the next two sentences of the article | therefore , a faithful reconstruction of the entire set of complexes ( the ` complexosome ' ) from the physical interactions among proteins ( the ` interactome ' ) is essential to not only understand complex formations , but also the higher level cellular organization .
protein complexes constitute _ modular _ functional units within the network of physical interactions , the ppi network@xcite . from a biological perspective , this modularity is a result division of labor and of evolution to provide robustness against mutation and chemical attacks@xcite . from a topological perspective , this modularity is a result of proteins within complexes being densely connected to each other than to the rest of the network@xcite . since the advent of high - throughput " screening in molecular biology in the late 1990s and early 2000s |
7,811 | Suppose that you have an abstract for a scientific paper: most of the current theories on the p - wave superfluid in cold atomic gases are based on the effective - range theory for the two - body scattering , where the low energy p - wave scattering amplitude @xmath0 is given by @xmath1 $ ] , where @xmath2 is the incident momentum , and @xmath3 and @xmath4 are the @xmath2-independent scattering volume and effective - range , respectively . however , due to the long - range nature of the van der waals interaction between two colliding ultracold atoms , the p - wave scattering amplitude of the two atoms is not described by the effective - range theory @xcite . in this paper
we provide an explicit calculation for the p - wave scattering of two ultracold atoms near the p - wave magnetic feshbach resonance ( pmfr ) .
we show that the low energy p - wave scattering amplitude in the presence of pmfr takes the form @xmath5 $ ] where @xmath6 @xmath7 and @xmath8 are @xmath2-dependent parameters .
based on this result , we show sufficient conditions for the effective range theory to be a good approximation of the exact scattering amplitude . using these conditions
we show that the effective - range theory is a good approximation for the p - wave scattering in the ultracold gases of @xmath9li and @xmath10k when the scattering volume is enhanced by the resonance . .
And you have already written the first three sentences of the full article: recently , ultracold atomic gases with strong p - wave interaction have attracted broad interest both experimentally expk40 , expk40b , expk40mola , expk40dipo , expk40molb , expli6a , expli6b , expli6c , expli6molsca , expli6r87 , explik , expli6mol , expkrb and theoretically pyou,2dpsfa , psfi,2dpsfb , psf1certa , psf1certb , psferta , psfa , p2dsfb , psff,2dpsfc , psfh , p2dsfa , psfc , 1dpsfb , psfe , pssfa , psfertc , gpra , 1dpsfa , psfb , psfertb , psf1certc , pfrvortex , psfola , pbosonert , psfbosefermi , twofermionerta , maqidajpsj1 , maqidajpsj2,zinnerepjd , maqidaprl1,pra2010a , maqidapra1,maqidapra2,maqidapra3,xxxa , stoofprl , p3bert , ppseudopotentialerta , p2bfr , ppseudopotentialertb , ppseudopotentialc , ppseudopotentiald , ppseudopotentiale , prlblume , nf1,nf2,nf3,nf4 .
the p - wave magnetic feshbach resonances , which can generate tunable p - wave ineratomic interactions , have been observed in the cold gases of @xmath11k @xcite , @xmath12li expli6a , expli6b , @xmath12li-@xmath13rb mixture expli6r87 , @xmath12li-@xmath14k mixture @xcite , and @xmath15k-@xmath13rb mixture @xcite .
the p - wave feshbach molecules have also been created and studied in the gases of @xmath16k @xcite and @xmath12li expli6a , expli6c , expli6mol , expli6molsca ..
Please generate the next two sentences of the article | these experimental achievements stimulate theoretical researches on the quantum superfluid in ultracold atomic gases with strong p - wave interactions pyou,2dpsfa , psfi,2dpsfb , psf1certa , psf1certb , psferta , psfa , p2dsfb , psff,2dpsfc , psfh , p2dsfa , psfc , 1dpsfb , psfe , pssfa , psfertc , gpra , 1dpsfa , psfb , psfertb , psf1certc , pfrvortex , psfola , pbosonert , psfbosefermi , maqidajpsj1,maqidajpsj2 , zinnerepjd , maqidaprl1,pra2010a , maqidapra1,maqidapra2,maqidapra3,xxxa , stoofprl , as well as the relevant few - body problems @xcite .
until now , most theories of ultracold atomic gases with strong p - wave interactions psf1certa , psf1certb , psferta , psfertc , psfertb , psf1certc , pbosonert , stoofprl , twofermionerta , p3bert , ppseudopotentialerta , p2bfr , ppseudopotentialertb are based on the low energy expansion of the p - wave scattering amplitude @xmath17 given by the effective - range theory @xcite @xmath18here @xmath19 is the relative momentum of the two atoms ; @xmath20 is the scattering volume and @xmath4 is the effective - range . |
7,812 | Suppose that you have an abstract for a scientific paper: recent calculations of charge symmetry violation ( csv ) in the valence quark distributions of the nucleon have revealed that the dominant symmetry breaking contribution comes from the mass associated with the spectator quark system .
assuming that the change in the spectator mass can be treated perturbatively , we derive a model independent expression for the shift in the parton distributions of the nucleon .
this result is used to derive a relation between the charge and flavor asymmetric contributions to the valence quark distributions in the proton , and to calculate csv contribution to the nucleon sea . the csv contribution to the gottfried sum rule
is also estimated , and found to be small .
-0.35 in 0.00 in 0.25 in 6.50 in 8.5 in [ [ section ] ] recent measurements of the flavor @xcite and spin @xcite dependence of quark distributions in the nucleon have led to a revival of interest in the soft qcd physics that determines the shape and normalization of parton distributions @xcite , and has led to a re - examination of some of the fundamental assumptions embodied in the parametrizations @xcite used to describe data from high energy experiments . in particular , the violation of charge symmetry in the valence quark distributions has been calculated by a number of authors @xcite in the context of quark models , and surprisingly large violations , as large as 5 - 10% , have been found at large @xmath0 @xcite . although charge symmetry is assumed in all phenomenological parton distributions , there is not a great deal of direct experimental evidence which justifies this assumption . the strongest upper limit on parton charge symmetry violation(csv ) can be obtained by comparing the @xmath1 structure function for charged lepton deep inelastic scattering with the @xmath1 structure function measured in neutrino - induced charged current reactions .
the ccfr group has recently carried out such a test using the most recent available data @xcite .
they compared their neutrino cross sections....
And you have already written the first three sentences of the full article: in this paper , we have used the adelaide approach to calculating quark model parton distributions to calculate the effect of csv on the parton distributions of the proton . for the valence quarks ,
we verify in a model independent fashion the anomalously large csv effects observed in the minority valence quark distribution by several authors @xcite , and we relate these distributions to the difference between the @xmath5 and @xmath6 valence distributions . since there is little data to constrain the size of the csv distributions , proposed tests of csv @xcite will provide a sensitive test of the physics contained in qcd - inspired models of the nucleon . additionally , we have made estimates of the size of csv effects in the nucleon sea .
first , we assume a strong violation of charge symmetry , which would alter the value of sum rules which assume charge symmetry ..
Please generate the next two sentences of the article | for the gottfried sum rule , there is no csv contributions unless there is a simultaneous violation of flavor symmetry in either the sea or valence quarks . in either case
, we estimate that the csv contributions to the gottfried sum rule are much smaller than are suggested by experiment . |
7,813 | Suppose that you have an abstract for a scientific paper: linear response theory describes quantum measurement with an arbitrary detector weakly coupled to a measured system .
this description produces generic quantitative relation characterizing the detector that is analogous to the fluctuation - dissipation theorem for equilibrium systems .
the detector characteristic obtained in this way shows how efficient the trade - off is between the back - action dephasing and information acquisition by the detector . .
And you have already written the first three sentences of the full article: if one puts aside philosophical questions created by the perceived counterintuitive features of the quantum mechanics that are frequently discussed in the literature on the quantum measurement problem ( an entry point to this literature is provided , e.g. , by the collections of papers @xcite or monographs @xcite ) it is easy to see that the physics of quantum measurements is fairly well understood by now at least on a qualitative level .
the process of quantum measurement is dynamic interaction between a microscopic quantum system and a macroscopic detector that establishes correlations between the states of these systems .
although it is impossible to give a universal definition of `` macroscopic '' in this context , a reasonable working definition is that the macroscopic detector is a system with negligible quantum fluctuations ..
Please generate the next two sentences of the article | such systems are quite abundant in nature and can be described quantitatively within the framework of quantum mechanics .
since the description of quantum measurement process as an interaction between microscopic and macroscopic systems is quite broad , it is of interest to see whether there are any universal quantitative features of this process that are independent of specific physical realization of the detectors and the measured system . |
7,814 | Suppose that you have an abstract for a scientific paper: we apply the quantum optimal control theory based on the krotov method to implement single - qubit @xmath0 and @xmath1 gates and two - qubit cnot gates for inductively coupled superconducting flux qubits with fixed qubit transition frequencies and fixed off - diagonal qubit - qubit coupling . our scheme that shares the same advantage of other directly coupling schemes requires no additional coupler subcircuit and control lines .
the control lines needed are only for the manipulation of individual qubits ( e.g. , a time - dependent magnetic flux or field applied on each qubit ) .
the qubits are operated at the optimal coherence points and the gate operation times ( single - qubit gates @xmath2 ns ; cnot gates @xmath3 ns ) are much shorter than the corresponding qubit decoherence time . a cnot gate or other general quantum gates
can be implemented in a single run of pulse sequence rather than being decomposed into several single - qubit and some entangled two - qubit operations in series by composite pulse sequences .
quantum gates constructed via our scheme are all with very high fidelity ( very low error ) as our optimal control scheme takes into account the fixed qubit detuning and fixed two - qubit interaction as well as all other time - dependent magnetic - field - induced single - qubit interactions and two - qubit couplings .
the effect of leakage to higher energy - level states and the effect of qubit decoherence on the quantum gate operations are also discussed . .
And you have already written the first three sentences of the full article: superconducting josephson junction devices and circuits are proving to be promising systems for quantum information processing @xcite . due to the great controllability of the qubits and microwaves in the superconducting circuit systems , single - qubit @xcite ,
two - qubit @xcite , and three - qubit @xcite operations have been experimentally demonstrated .
the next natural step is to develop robust , high - fidelity and scalable gates for larger scale quantum computation ..
Please generate the next two sentences of the article | an essential prerequisite for quantum information processing and quantum computation is precise coherent control of quantum systems or quantum bits ( qubits ) . here , we focus our discussion on high - fidelity quantum control for superconducting flux qubit systems .
the flux qubits have an advantage over other types of superconducting qubits in the larger anharmonic energy level structure , i.e. the difference between adjacent transition frequencies is larger @xcite and thus less leakage to higher energy - level states . several schemes to implement local qubit operations and controllable couplings using microwaves for multi - flux - qubit systems have been proposed or / and realized . |
7,815 | Suppose that you have an abstract for a scientific paper: we consider the distribution of conductance fluctuations in disordered quantum dots with single channel leads . using a perturbative diagrammatic approach , valid for continuous level spectra
, we describe dephasing due to processes within the dot by considering two different contributions to the level broadening , thus satisfying particle number conservation . instead of a completely non - gaussian distribution , which occurs for zero dephasing , we find for strong dephasing that the distribution is mainly gaussian with non - universal variance and non - gaussian tails . 2 .
And you have already written the first three sentences of the full article: soon after the theoretical prediction of universal conductance fluctuations ( ucf ) in disordered electronic samples,@xmath0 it was shown that their distribution function is mainly gaussian.@xcite these considerations referred to a weakly disordered _ open _
sample connected to a reservoir by broad external contacts . in this case , after diffusing through the sample of size @xmath1 during time @xmath2 electrons are inelastically scattered in the reservoir ( @xmath3 is the diffusion coefficient ) . the resulting uncertainty in the level position , i.e. level broadening @xmath4 , is of the order of the thouless energy @xmath5 , and @xmath6 , where @xmath7 is the mean level spacing .
this picture remains almost unchanged in the presence of relatively strong inelastic processes within the sample@xcite which lead to dephasing ( the loss of phase - coherence ) at the time scale @xmath8 : the conductance distribution remains almost gaussian although its variance is no longer universal but decreases @xmath9 where @xmath10 is a spatial dimensionality ..
Please generate the next two sentences of the article | in contrast , it has been shown more recently that the conductance distribution is pronouncedly non - gaussian in almost closed systems like chaotic cavities with single channel leads @xcite , quantum dots in the regime of coulomb blockade@xcite where the distribution of the heights of the coulomb blockade peaks has been measured experimentally,@xcite or isolated conducting rings threaded by an aharonov
bohm flux.@xcite weak transmission through the contacts means that the electrons typically spend more time in the system than @xmath11 so the broadening of energy levels @xmath12 . |
7,816 | Suppose that you have an abstract for a scientific paper: motivated by the desire to test modified gravity theories exhibiting the vainshtein mechanism , we solve in various physically relevant limits , the retarded galileon green s function ( for the cubic theory ) about a background sourced by a massive spherically symmetric static body .
the static limit of our result will aid us , in a forthcoming paper , in understanding the impact of galileon fields on the problem of motion in the solar system . in this paper
, we employ this retarded green s function to investigate the emission of galileon radiation generated by the motion of matter lying deep within the vainshtein radius @xmath0 of the central object : acoustic waves vibrating on its surface , and the motion of compact bodies gravitationally bound to it .
if @xmath1 is the typical wavelength of the emitted radiation , and @xmath2 is the typical distance of the source from the central mass , with @xmath3 , then , compared to its non - interacting massless scalar counterpart , we find that the galileon radiation rate is suppressed by the ratio @xmath4 at the monopole and dipole orders at high frequencies @xmath5 . however , at high enough multipole order , the radiation rate is enhanced by powers of @xmath6 . at low frequencies
@xmath7 , and when the motion is non - relativistic , galileon waves yield a comparable rate for the monopole and dipole terms , and are amplified by powers of the ratio @xmath6 for the higher multipoles . .
And you have already written the first three sentences of the full article: the study of the problem of motion in general relativity ( gr ) has been a central theme in testing its validity .
for instance , the post - newtonian program , computing gr corrections to the newtonian gravitational potential between massive bodies , is crucial to understanding gravity in our solar system . in
the past decade or more , the post - newtonian analysis of weak field gravity has also been developed to very high order in perturbation theory because of the need to model gravitational waves ( gws ) from inspiraling compact binaries , which is expected to be a major source for detectors like advanced ligo . at the same time.
Please generate the next two sentences of the article | , the discovery of cosmic acceleration and its associated cosmological constant problem , has prompted many attempts to modify how gravity operates at large ( astrophysical ) length scales .
one such example is the family of scalar field theories known as galileons @xcite , building on interesting properties of a limit of the dvali - gabadadze - porrati model @xcite . |
7,817 | Suppose that you have an abstract for a scientific paper: entanglement between individual spins can be detected by using thermodynamics quantities as entanglement witnesses .
this applies to collective spins also , provided that their internal degrees of freedom are frozen , as in the limit of weakly - coupled nanomagnets . here
, we extend such approach to the detection of entanglement between subsystems of a spin cluster , beyond such weak - coupling limit .
the resulting inequalities are violated in spin clusters with different geometries , thus allowing the detection of zero- and finite - temperature entanglement . under relevant and experimentally verifiable conditions ,
all the required expectation values can be traced back to correlation functions of individual spins , that are now made selectively available by four - dimensional inelastic neutron scattering .
a great effort has been devoted in the last years to the generation and detection of quantum entanglement in diverse physical systems @xcite .
one of the most practical means in the latter perspective is represented by entanglement witnesses @xcite .
these are observables that can be experimentally accessed in the system of interest , and whose expectation values can exceed given thresholds only in the presence of specific forms of entanglement .
the violation of the corresponding inequalities allows the detection of entanglement , without requiring the derivation of the systems state , and with a variable amount of knowledge of the system hamiltonian . in spin systems ,
routinely measured thermodynamic quantities , such as magnetic susceptibility , can be used as entanglement witnesses @xcite . in clusters of antiferromagnetically coupled spins ,
internal energy allows one to demonstrate the non full - separability of the equilibrium state at low temperatures @xcite .
exchange energy also allows the detection of multipartite entanglement in qubit systems @xcite and in clusters formed by @xmath0 spins @xcite . in the same spirit
, spin - squeezing inequalities can be used to....
And you have already written the first three sentences of the full article: in the present section , we derive inequalities that allow to detect entanglement between two subsystems @xmath1 and @xmath2 of a spin cluster , formed by @xmath10 and @xmath11 individual spins , respectively .
the approach for passing from individual to composite spins is outlined in subsection [ subsec1 ] .
different entanglement inequalities are typically used to detect entanglement in low- and in high - spin systems ..
Please generate the next two sentences of the article | these two cases are thus treated separately ( subsections [ subsec2 ] and [ subsec3 ] , respectively ) .
a possible generalization of the approach to the case of more than two subsystems is sketched in subsection [ subsec4 ] . |
7,818 | Suppose that you have an abstract for a scientific paper: we discuss the impact of the cosmological environment on the evolution of dark matter halos using a high - resolution simulation within a spatially flat @xmath0cdm cosmology . .
And you have already written the first three sentences of the full article: it is generally believed that cold dark matter ( dm ) dominates the mass in the universe and significantly affects both the process of galaxy formation and the large - scale distribution of galaxies .
here we present results of a study of the formation and the evolution of the dm component of galaxies , dm halos .
the structure of the halos depends on the environment ( e.g. , avila - reese et al ..
Please generate the next two sentences of the article | 1999 ) , so that the properties of galaxies are also expected to depend on the cosmological environment . for our analysis
we use a low - density flat cosmological model with cosmological constant @xmath0 , which have been proved to be very successful in describing most of the observational data at both low and high redshifts : @xmath1 , @xmath2 , @xmath3 km / s / mpc , @xmath4 gyrs . |
7,819 | Suppose that you have an abstract for a scientific paper: using a simple phenomenological parametrization of the reaction amplitude we calculated @xmath0-particle spectrum in the reaction p+@xmath1b@xmath2 at the resonance proton energy 675 kev .
the parametrization includes breit - wigner factor with an energy dependent width for intermediate @xmath3 state and the coulomb and the centrifugal factors in @xmath0-particle emission vertexes .
the shape of the spectrum consists of a well defined peak corresponding to emission of the primary @xmath0 and a flat shoulder going down to very low energy .
we found that below 1.5 mev there are 17.5% of @xmath0 s and below 1 mev there are 11% of them . .
And you have already written the first three sentences of the full article: successful realization of aneutronic fusion idea would greatly reduce problems associated with neutron radiation such as ionizing damage , neutron activation , and requirements for biological shielding , remote handling , and safety issues .
one of the reactions discussed in this respect is the reaction p+@xmath1b@xmath2 .
there are at least two proposals @xcite how to use this reaction for energy production ..
Please generate the next two sentences of the article | the shape of @xmath0-particles spectrum , especially its low energy tail is of crucial importance for realisation of these projects .
existing measurements @xcite produce the spectra for fixed angles of @xmath0-particles that does not say much about integrated spectrum . in this paper |
7,820 | Suppose that you have an abstract for a scientific paper: following the long - lived qualitative - dynamics tradition of explaining behavior in complex systems via the architecture of their attractors and basins , we investigate the patterns of switching between qualitatively distinct trajectories in a network of synchronized oscillators .
our system , consisting of nonlinear amplitude - phase oscillators arranged in a ring topology with reactive nearest neighbor coupling , is simple and connects directly to experimental realizations .
we seek to understand how the multiple stable synchronized states connect to each other in state space by applying gaussian white noise to each of the oscillators phases .
to do this , we first identify a set of locally stable limit cycles at any given coupling strength . for each of these attracting states ,
we analyze the effect of weak noise via the covariance matrix of deviations around those attractors .
we then explore the noise - induced attractor switching behavior via numerical investigations .
for a ring of three oscillators we find that an attractor - switching event is always accompanied by the crossing of two adjacent oscillators phases . for larger numbers of oscillators
we find that the distribution of times required to stochastically leave a given state falls off exponentially , and we build an attractor switching network out of the destination states as a coarse - grained description of the high - dimensional attractor - basin architecture .
= 1 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _....
And you have already written the first three sentences of the full article: from the gene regulatory networks that control organismal development @xcite and the coherent oscillations between brain regions responsible for cognition @xcite to the connected technologies that support critical infrastructure @xcite , systems at many scales of modern society rely on the coordination of the dynamics of interdependent systems . analyzing the mechanisms driving such complex networks presents serious challenges to dynamical systems , statistical mechanics , and control theory , including but not limited to the overtly high dimension of their state spaces .
this precludes directly identifying and visualizing their attractors and attractor - basin organization .
moreover , without knowledge of the latter large - scale architecture , predicting network behavior , let alone developing control strategies to maintain function or mitigate failure , is impossible . to shed light on these challenges , we explore limit - cycle attractors arising when rings of coupled nonlinear oscillators synchronize ..
Please generate the next two sentences of the article | we demonstrate how synchronization emerges and stabilizes and identify the diversity of synchronized states .
we probe the global attractor - basin architecture by driving the networks with noise , capturing how the distinct synchronized states can be reached from each other via what we call attractor switching networks . |
7,821 | Suppose that you have an abstract for a scientific paper: we show that a reversible pumping mechanism operating between two states of a kinetic network can give rise to poisson transitions between these two states .
an external observer , for whom the pumping mechanism is not accessible , will observe a markov chain satisfying local detailed balance with an emerging effective force induced by the hidden pump . due to the reversibility of the pump
, the actual entropy production turns out to be lower than the coarse grained entropy production estimated from the flows and affinities of the resulting markov chain .
moreover , in presence of a large time scale separation between the fast pumping dynamics and the slow network dynamics , a finite current with zero dissipation may be produced .
we make use of these general results to build a synthetase - like kinetic scheme able to reversibly produce high free energy molecules at a finite rate and a rotatory motor achieving 100% efficiency at finite speed .
entropy production measures dissipation and is the key quantity to assess the performance of a kinetic process .
the efficiency of chemical motors or of biochemical processes such as metabolic cycles , replication , transcription , or proofreading , typically achieves its maximum value when the entropy production is minimal .
hill , in his classic work @xcite on the transduction of free energy in chemical reactions , provided the basic tools to calculate the entropy production of processes modeled by kinetic networks .
closely related results were also found by schnakenberg @xcite .
they showed that the entropy production in a network consists of a sum of positive edge contributions , each expressed as the product of a probability flux across the edge times an edge affinity ( or thermodynamic force ) .
their theoretical framework constitutes the basis of stochastic thermodynamics @xcite which has become central for the study of molecular machines @xcite . in many applications
the observer has only a partial access to the kinetic network .
....
And you have already written the first three sentences of the full article: we first review the main results concerning energetics and entropy production in kinetic networks . consider a system interacting with a reservoir at temperature @xmath0 and with states @xmath1 that have energies @xmath2 and are occupied with probabilities @xmath3 .
the system dynamics is described by a markovian master equation @xmath4,\ ] ] where @xmath5 is the net probability current from site @xmath6 to site @xmath1 .
the rates @xmath7 describing the reservoir induced transitions from @xmath6 to @xmath1 satisfy local detailed balance @xmath8 where @xmath9 and @xmath10 is a non - conservative thermodynamic force pointing from @xmath6 to @xmath1 which could be induced for instance by a non - equilibrium chemical reservoir or a non - conservative mechanical force ..
Please generate the next two sentences of the article | the state energies @xmath2 may change in time , @xmath11 , due to the action of an external agent . for this generic scenario an unambiguous formulation of non - equilibrium thermodynamics
ensues @xcite . |
7,822 | Suppose that you have an abstract for a scientific paper: the spreading dynamics of surfactant molecules on a thin fluid layer is of both fundamental and practical interest .
a mathematical model formulated by gaver and grotberg @xcite describing the spreading of a single layer of insoluble surfactant has become widely accepted , and several experiments on axisymmetric spreading have confirmed its predictions for both the height profile of the free surface and the spreading exponent ( the radius of the circular area covered by surfactant grows as @xmath0 ) . however , these prior experiments have primarily utilized surfactant quantities exceeding ( sometimes far exceeding ) a monolayer . in this paper
, we report that this regime is characterized by a mismatch between the timescales of the experiment and model , and additionally find that the spatial distribution of surfactant molecules differs substantially from the model prediction . for experiments performed in the monolayer regime for which the model was developed ,
the surfactant layer is observed to have a spreading exponent of less than @xmath1 , far below the predicted value , and the surfactant distribution is also in disagreement .
these findings suggest that the model is inadequate for describing the spreading of insoluble surfactants on thin fluid layers . .
And you have already written the first three sentences of the full article: axisymmetric spreading of an insoluble surfactant on a thin layer of incompressible fluid has been the subject of numerous experimental and mathematical studies @xcite . motivated by the biomedical application of aerosol medications delivered to the thin fluid lining the lung , gaver and grotberg derived a mathematical model , based on lubrication theory , that couples the height profile of the fluid surface @xmath2 to the local surfactant concentration @xmath3 .
this model captures the driving force associated with the marangoni surface stress induced by spatial variations in surfactant concentration , which in turn depends on an equation of state that specifies the dependence of surface tension @xmath4 on @xmath5 .
while the model was developed for monolayer applications of surfactant , it has come to be applied both above @xcite and near @xcite the critical monolayer concentration @xmath6 , the concentration above which a single layer of surfactant molecules can no longer form ..
Please generate the next two sentences of the article | similar models have been used to study thin films in bronchial systems @xcite , ocular systems including blinking dynamics @xcite , bulk solute transport @xcite , drying of latex paint @xcite , ink - jet printing @xcite , and secondary oil recovery @xcite .
numerical simulations have been used to confirm several predictions of the model @xcite based on analysis of self - similar solutions . |
7,823 | Suppose that you have an abstract for a scientific paper: we calculate the constraints on the constants of hypothetical long - range interactions which follow from the recent measurement of the casimir force . a comparison with previous constraints is given .
the new constraints are up to a factor of 3000 stronger in some parameter regions .
= 22.5 cm hep - th/9705101 new constraints on the yukawa - type hypothetical interaction from the recent casimir force measurement m. bordag , g.t .
gillies and v.m . .
And you have already written the first three sentences of the full article: the existence of yukawa - type long - range interactions between the atoms of macro - bodies is predicted by the modern unified gauge - field theories of fundamental interactions , from the principles of supersymmetry and supergravity .
these forces may be understood as a result of the exchange of light elementary particles ( such as the axion , scalar axion , dilaton , spin - one antigraviton etc .
they may be called _ long - range _ because their range of action is much larger than the typical nuclear sizes ..
Please generate the next two sentences of the article | additional yukawa - type interactions may arise also from corrections to the newtonian gravitational law at small distances @xcite . at present , this subject is actively investigated .
there are a large number of papers from both theoreticians and experimentalists . an extended annotative collection of references can be found in @xcite . |
7,824 | Suppose that you have an abstract for a scientific paper: we present a simple and non empirical method to determine optimal scaling coefficients , within the ( spin component)scaled mp2 approach , for calculating intermolecular potential energies of noncovalently interacting systems .
the method is based on an observed proportionality between ( spin component ) mp2 and ccsd(t ) energies for a wide range of intermolecular distances and allows to compute with high accuracy a large portion of the dissociation curve at the cost of a single ccsd(t ) calculation .
the accuracy of the present procedure is assessed for a series of noncovalently interacting test systems : the obtained results reproduce ccsd(t ) quality in all cases and definitely outperform conventional mp2 , ccsd and scs
mp2 results .
the difficult case of the beryllium dimer is also considered . .
And you have already written the first three sentences of the full article: noncovalent interactions of organic molecules play a fundamental role in biochemistry , solvation , surface science , and supermolecular chemistry .
an accurate description of the noncovalent interactions is thus very important for many applications @xcite .
actually , the `` golden standard '' for the simulation of noncovalently interacting complexes is the coupled cluster single and double with perturbative triple ( ccsd(t ) ) approach @xcite ..
Please generate the next two sentences of the article | however , the ccsd(t ) method has a high computational cost , scaling as @xmath0 , and it is not easily applicable in general , especially when numerous single point calculations are required as in the determination of a potential energy surface ( pes ) or for geometry optimizations
. in various applications is thus necessary to recover to lower |
7,825 | Suppose that you have an abstract for a scientific paper: resonant activation in temporally driven spin - boson systems subjected to strong dissipation is researched by means of both , analytical and extensive numerical investigations .
the phenomenon of resonant activation emerges in the presence of either fluctuating or periodically varying driving fields . addressing the incoherent regime ,
a characteristic minimum emerges in the mean first passage time ( mfpt ) to reach an absorbing neighboring state whenever the intrinsic time scale of the modulation matches the characteristic time scale of the system dynamics . for the case of deterministic periodic
driving the first passage time statistics displays a complex , multi - peaked first passage time probability density , which depends crucially on the details of the initial driving phase , the driving frequency and its strength . as an interesting feature we find that the mfpt enters the resonant activation regime at a critical frequency @xmath0 which depends very weakly on the strength of the driving . .
And you have already written the first three sentences of the full article: the objective of the escape dynamics out of a metastable state has been thoroughly investigated since the seminal work of kramers @xcite .
a quantity of primary interest to establish the time scale of the escape dynamics of a classical brownian particle in the presence of a potential barrier is the mean first passage time ( mfpt ) ; i.e. the average time it takes for a particle driven by noise to reach a target position beyond an intervening barrier top @xcite .
the topic of evaluating the mfpt in the presence of external modulations of either stochastic or also deterministic nature has ample applications , among others , in neuronal models which are characterized by a time - varying voltage threshold ; e.g. see refs ..
Please generate the next two sentences of the article | @xcite . + a minimum occurring in the mfpt versus increasing frequency scale of the modulation is known in the literature as resonant activation .
the phenomenon may emerge when the time scale of the barrier modulation matches the characteristic time scale of the escape dynamics . |
7,826 | Suppose that you have an abstract for a scientific paper: we give a detailed analysis of the cost used by the @xmath0-evolutionary algorithm .
the problem has been approached in the evolutionary algorithm literature under various views , formulation and degree of rigor .
our asymptotic approximations for the mean and the variance represent the strongest of their kind .
the approach we develop is also applicable to characterize the limit laws and is based on asymptotic resolution of the underlying recurrence .
while most approximations have their simple formal nature , we elaborate on the delicate error analysis required for rigorous justifications . .
And you have already written the first three sentences of the full article: the last two decades or so have seen an explosion of application areas of evolutionary algorithms ( eas ) in diverse scientific or engineering disciplines .
an ea is a random search heuristic , using evolutionary mechanisms such as crossover and mutation , for finding a solution that often aims at maximizing an objective function .
eas are proved to be extremely useful for combinatorial optimization problems because they can solve complicated problems with reasonable efficiency using only basic mathematical modeling and simple operators ; see @xcite for more information ..
Please generate the next two sentences of the article | although eas have been widely applied in solving practical problems , the analysis of their performance and efficiency , which often provides better modeling prediction for practical uses , are much less addressed ; only computer simulation results are available for most of the eas in use .
see for example @xcite . |
7,827 | Suppose that you have an abstract for a scientific paper: we have investigated the influence of potassium intercalation on the formation of the charge - density wave ( cdw ) instability in by means of electron energy - loss spectroscopy and density functional theory .
our observations are consistent with a filling of the conduction band as indicated by a substantial decrease of the plasma frequency in experiment and theory . in addition
, elastic scattering clearly points to a destruction of the cdw upon intercalation as can be seen by a vanishing of the corresponding superstructures .
this is accompanied by a new superstructure , which can be attributed to the intercalated potassium .
based on the behavior of the @xmath0-axis upon intercalation we argue in favor of interlayer - sites for the alkali - metal and that the lattice remains in the @xmath1 modification . .
And you have already written the first three sentences of the full article: due to their layered structure , transition - metal dichalcogenides ( tmdcs ) show a variety of anisotropic properties , such as thermal expansion , sound velocity and thermal as well as electrical conductivity @xcite .
the lowered dimensionality often also manifests itself in the occurrence of a charge - density wave ( cdw ) phase transition within the @xmath2-plane of the crystal . in the present example of
, this cdw superstructure is incommensurate below and becomes commensurate going below @xcite ..
Please generate the next two sentences of the article | a detailed study of the phase transition containing an incommensurate superstructure followed by a lock - in transition to a commensurate ordering vector has for example been realised by neutron scattering @xcite or x - ray diffraction @xcite .
this transition as well as the cdw state itself were also investigated by angle - resolved photoemission measurements @xcite , clearly showing the opening of a gap at the fermi level when going to the ordered phase . however , the reasoning that the fermi surface is partially gapped already for temperatures far above the phase transition and the link of this fact to a possible nesting mechanism for the cdw order is supported by reflectivity as well as resistivity measurements @xcite . |
7,828 | Suppose that you have an abstract for a scientific paper: einstein s field equations in general relativity admit a variety of solutions with spacetime singularities . numerical relativity has recently revealed the properties of somewhat generic spacetime singularities .
it has been found that in a variety of systems self - similar solutions can describe asymptotic or intermediate behaviour of more general solutions .
the typical example is the convergence to an attractor self - similar solution in gravitational collapse .
this is closely related to the cosmic censorship violation in the spherically symmetric collapse of a perfect fluid .
the self - similar solution also plays an important role in critical phenomena in gravitational collapse .
the critical phenomena are understood as the intermediate behaviour around a critical self - similar solution .
we see that the convergence and critical phenomena are understood in a unified manner in terms of attractors of codimension zero and one , respectively , in renormalisation group flow . .
And you have already written the first three sentences of the full article: the essential assumption of general relativity is that the spacetime is given by a curved manifold with a metric @xmath0 of the lorentzian signature .
@xmath1 denotes the inverse of @xmath2 .
the curvature of the spacetime is given by the riemann tensor @xmath3 ..
Please generate the next two sentences of the article | the metric lifts and lowers the tensor indices .
a vector is timelike , spacelike and null if @xmath4 , @xmath5 and @xmath6 , respectively . |
7,829 | Suppose that you have an abstract for a scientific paper: * abstract : * in this paper , we search the existence of bianchi - v string cosmological model in @xmath0 gravity with power law expansion .
einstein s field equations have been solved by taking into account the law of variation of hubble s parameter that yields the constant value of deceleration parameter ( dp ) .
we observe that the massive strings dominate the early universe but they do not survive for long time and finally disappear from the universe .
we examine the nature of classical potential and also discuss the physical properties of universe . + * keywords : * early universe , @xmath0 gravity and cosmological parameters . .
And you have already written the first three sentences of the full article: the spontaneous breakdown of symmetries in the early universe that produce linear discontinuities in the field is called cosmic string ( kibble 1976 ) .
the cosmic strings are also common in modern string cosmologies . in 2003 , general interest in cosmic strings was heightened by the discovery of what seemed at first to be a plausible candidate for lensing by a cosmic string . a pair of images of elliptical galaxies separated by 1.8 arc seconds was found to have the same redshift , @xmath1 , and the same spectra .
sazhim et al ( 2003 ) confirmed that these images were not distorted in the way that would be expected for lensing of a single galaxy but are consistent with lensing by cosmic string . in the literature ,.
Please generate the next two sentences of the article | the line like structure of cosmic strings with particle attached to them are considered as possible seeds for galaxy formation at the early stages of the evolution of universe . in the past time , stachel ( 1980 ) , letelier ( 1983 ) and vilenkin et al ( 1987 ) have studied different aspects of string cosmological models in general relativity .
reddy ( 2003 ) , reddy and naidu ( 2007 ) and recently yadav ( 2013 ) have investigated anisotropic string cosmological models in scalar - tensor theory of gravitation . + harko et al ( 2011 ) proposed @xmath0 gravity theory by taking into account the gravitational lagrangian as the function of ricci scalar r and of the trace of energy - stress tensor t. they have obtained the equation of motion of test particle and the gravitational field equation in metric formalism both . |
7,830 | Suppose that you have an abstract for a scientific paper: * background : * the @xmath0ne(p,@xmath1)@xmath2na reaction is the most uncertain process in the neon - sodium cycle of hydrogen burning . at temperatures relevant for nucleosynthesis in asymptotic giant branch stars and classical novae , its uncertainty is mainly due to a large number of predicted but hitherto unobserved resonances at low energy .
* purpose : * a new direct study of low energy @xmath0ne(p,@xmath1)@xmath2na resonances has been performed at the laboratory for underground nuclear astrophysics ( luna ) , in the gran sasso national laboratory , italy .
* method : * the proton capture on @xmath0ne was investigated in direct kinematics , delivering an intense proton beam to a @xmath0ne gas target .
@xmath1 rays were detected with two high - purity germanium detectors enclosed in a copper and lead shielding suppressing environmental radioactivity .
* results : * three resonances at 156.2 kev ( @xmath3 = ( [email protected])@xmath510@xmath6 ev ) , 189.5 kev ( @xmath3 = ( [email protected])@xmath510@xmath7 ev ) and 259.7 kev ( @xmath3 = ( [email protected])@xmath510@xmath7 ev ) proton beam energy , respectively , have been observed for the first time . for the levels at @xmath8
= 8943.5 , 8975.3 , and 9042.4 kev excitation energy corresponding to the new resonances , the @xmath1-decay branching ratios have been precisely measured .
three additional , tentative resonances at 71 , 105 and 215 kev proton beam energy , respectively , were not observed here . for the strengths of these resonances ,
experimental upper limits have been derived that are significantly more stringent than the upper limits reported in the literature .
* conclusions : * based on the present experimental data and also previous literature data , an updated thermonuclear reaction rate is provided in tabular and parametric form . the new reaction rate is significantly higher than previous evaluations at temperatures of 0.08 - 0.3 gk . .
And you have already written the first three sentences of the full article: the neon - sodium cycle of hydrogen burning ( nena cycle ) converts hydrogen to helium through a chain of proton induced reactions involving neon and sodium isotopes .
the nena cycle contributes negligibly to the energy budget , but it is of great importance for stellar nucleosynthesis , because it affects the abundances of the elements between @xmath9ne and @xmath10al @xcite .
predicting the abundances of nena cycle elements in different astrophysical objects has become highly topical since the discovery of the anticorrelation between sodium and oxygen abundances in red giant stars of globular clusters ( * ? ? ?.
Please generate the next two sentences of the article | * a review ) . in principle ,
material showing such a na - o anticorrelation may be produced by hydrogen burning when the temperature is so high that not only the cno cycle , but also the nena cycle is activated @xcite . in order to explain how such material can be brought to the stellar surface where it can be detected , |
7,831 | Suppose that you have an abstract for a scientific paper: dilational materials are stable three - dimensional isotropic auxetics with an ultimate poisson s ratio of @xmath0 .
we design , evaluate , fabricate , and characterize crystalline metamaterials approaching this ideal .
to reveal all modes , we calculate the phonon band structures . on this basis , using cubic symmetry , we can unambiguously retrieve all different non - zero elements of the rank-4 effective metamaterial elasticity tensor , from which all effective elastic metamaterial properties follow . while the elastic properties and the phase velocity remain anisotropic , the effective poisson s ratio indeed becomes isotropic and approaches @xmath0 in the limit of small internal connections .
this finding is also supported by independent static continuum - mechanics calculations . in static experiments on macroscopic polymer structures fabricated by three - dimensional printing , we measure poisson s ratios as low as @xmath1 in good agreement with theory .
microscopic samples are also presented .
_ keywords _ : mechanical metamaterials , acoustics , auxetics , dilational metamaterials .
And you have already written the first three sentences of the full article: auxetic materials are rather special and unusual elastic solids .
their poisson s ratio @xmath2 is negative , which means that it is easy to change their volume while fixing their shape , but it is hard to change their shape while fixing their volume @xcite .
this behavior is just opposite to that of an ideal liquid @xcite and to that of an ideal pentamode metamaterial @xcite . in general , auxetic materials.
Please generate the next two sentences of the article | can be anisotropic , in which case the poisson s ratio turns into a poisson s matrix @xcite .
there are no fundamental bounds for the values of the elements of the general poisson s matrix @xcite . in sharp contrast , there are established bounds for stable elastic isotropic media . here , the poisson s ratio is connected to the ratio of bulk modulus @xmath3 ( the inverse of the compressibility ) and shear modulus @xmath4 via @xcite @xmath5 for a stable elastic solid , neither bulk nor shear modulus can be negative . |
7,832 | Suppose that you have an abstract for a scientific paper: a conformal transformation of a uniform triangular pinning array produces a structure called a conformal crystal which preserves the six - fold ordering of the original lattice but contains a gradient in the pinning density .
here we use numerical simulations to show that vortices in type - ii superconductors driven with an ac drive over gradient pinning arrays produce the most pronounced ratchet effect over a wide range of parameters for a conformal array , while square gradient or random gradient arrays with equivalent pinning densities give reduced ratchet effects . in the conformal array , the larger spacing of the pinning sites in the direction transverse to the ac drive permits easy funneling of interstitial vortices for one driving direction , producing the enhanced ratchet effect . in the square array ,
the transverse spacing between pinning sites is uniform , giving no asymmetry in the funneling of the vortices as the driving direction switches , while in the random array , there are numerous easy - flow channels present for either direction of drive .
we find multiple ratchet reversals in the conformal arrays as a function of vortex density and ac amplitude , and correlate the features with a reversal in the vortex ordering , which is greater for motion in the ratchet direction .
the enhanced conformal pinning ratchet effect can also be realized for colloidal particles moving over a conformal array , indicating the general usefulness of conformal structures for controlling the motion of particles . .
And you have already written the first three sentences of the full article: when an assembly of particles are placed in an asymmetric potential , a net dc particle flow can arise due to a ratchet effect that occurs when an ac drive is applied or when the substrate is periodically switched on and off in the presence of a thermal bath @xcite .
ratchet effects on asymmetric substrates have been extensively studied in colloidal systems @xcite , granular matter @xcite , and polymers @xcite .
ratchet effects also appear in ac - driven vortices in type - ii superconductors in the presence of an asymmetric substrate @xcite , such as a quasi - one - dimensional periodic array produced by asymmetrically modulating the sample thickness @xcite , etching funnel - shaped channels for vortex flow @xcite , introducing asymmetry to the sample edges @xcite , or adding periodic pinning arrays in which the individual pinning sites have some form of intrinsic asymmetry @xcite . at lower vortex densities when collective interactions between vortices are weak , the ratchet effect produces a dc flow of vortices in the easy flow direction of the asymmetric substrate ; however , when collective effects are present it is possible to have reversals of the ratchet effect where for one set of parameters the vortices move in the easy direction while for another set of parameters they move in the hard direction @xcite ..
Please generate the next two sentences of the article | a ratchet effect can also be produced by a pinning array containing symmetric pinning sites arranged with a density gradient .
@xcite first studied vortex ratchet effects for random gradient array pinning geometries and found that the vortices undergo a net dc flow in the easy direction . |
7,833 | Suppose that you have an abstract for a scientific paper: the ways in which natural selection can allow the proliferation of cooperative behavior have long been seen as a central problem in evolutionary biology .
most of the literature has focused on interactions between pairs of individuals and on linear public goods games .
this emphasis led to the conclusion that even modest levels of migration would pose a serious problem to the spread of altruism in group structured populations . here
we challenge this conclusion , by analyzing evolution in a framework which allows for complex group interactions and random migration among groups .
we conclude that contingent forms of strong altruism can spread when rare under realistic group sizes and levels of migration .
our analysis combines group - centric and gene - centric perspectives , allows for arbitrary strength of selection , and leads to extensions of hamilton s rule for the spread of altruistic alleles , applicable under broad conditions . .
And you have already written the first three sentences of the full article: the evolution of cooperation and altruism are fundamental scientific challenges highlighted by their role in the major transitions in life s history , when natural selection acted simultaneously on several competing levels @xcite . in this context , the relevance of basic concepts , including group selection and hamilton s rule remain controversial @xcite . here
we address these problems by studying a framework for evolution in group structured populations that incorporates inter- and intra - group competition and migration . combining group - centric with gene - centric perspectives in a constructive group / kin selection approach ,
we build methodology that allows for the analysis of arbitrary non - linear fitness functions , resulting from complex multi - individual interactions across life cycles ..
Please generate the next two sentences of the article | we obtain the conditions for a rare social allele to invade the population .
this is obtained in a mathematically rigorous way , by analyzing the stability of the equilibrium in which this allele is absent . |
7,834 | Suppose that you have an abstract for a scientific paper: contextuality provides a unifying paradigm for nonclassical aspects of quantum probabilities and resources of quantum information .
unfortunately , most forms of quantum contextuality remain experimentally unexplored due to the difficulty of performing sequences of projective measurements on individual quantum systems . here
we show that two - point correlations between binary compatible observables are sufficient to reveal any form of contextuality .
this allows us to design simple experiments that are more robust against imperfections and easier to analyze , thus opening the door for observing interesting forms of contextuality , including those requiring quantum systems of high dimensions .
in addition , it allows us to connect contextuality to communication complexity scenarios and reformulate a recent result relating contextuality and quantum computation .
= 1 .
And you have already written the first three sentences of the full article: quantum theory ( qt ) is in conflict with noncontextual realism @xcite , that is , with the assumption that the results of measurements reveal pre - existing properties that are not affected by compatible measurements .
noncontextual realism is a legitimate assumption in so far as the statistics of the measurement outcomes are not perturbed by other measurements , or , in other words , whenever measurements can not be used to communicate information .
no signaling holds when the measurements are spacelike separated . if this is the case , noncontextual realism is called local realism ..
Please generate the next two sentences of the article | it is well known that qt is also in conflict with local realism @xcite .
however , most quantum violations of noncontextual realism do not occur in scenarios in which parties perform spacelike separated measurements . |
7,835 | Suppose that you have an abstract for a scientific paper: many models of heavy ion collisions employ relativistic hydrodynamics to describe the system evolution at high densities .
the cooper - frye formula is applied in most of these models to turn the hydrodynamical fields into particles . however , the number of particles obtained from the cooper - frye formula is not always positive - definite .
physically negative contributions of the cooper - frye formula are particles that stream backwards into the hydrodynamical region .
we quantify the cooper - frye negative contributions in a coarse - grained transport approach , which allows to compare them to the actual number of underlying particles crossing the transition hypersurface .
it is found that the number of underlying inward crossings is much smaller than the one the cooper - frye formula gives under the assumption of equilibrium distribution functions .
the magnitude of cooper - frye negative contributions is also investigated as a function of hadron mass , collision energy in the range @xmath0 gev , and collision centrality .
the largest negative contributions we find are around 13% for the pion yield at midrapidity at @xmath1 gev collisions . .
And you have already written the first three sentences of the full article: in the hot and dense system of strongly interacting matter created in heavy ion collisions the mean free path of the particles is much smaller than the size of the fireball .
this fact together with the assumption of fast thermal equilibration allows to apply relativistic hydrodynamics for the dynamical description of heavy ion collisions . at later times of the evolution and at its edges
the system is dilute , the mean free path is larger than system size , and hydrodynamics is not applicable ..
Please generate the next two sentences of the article | an adequate description of the system in those circumstances is provided by kinetic ( transport ) equations , such as the boltzmann equation or its modifications for the quantum case .
state of the art simulations of heavy ion collisions couple hydrodynamics for the early stage of the evolution to hadron transport for the late stage . |
7,836 | Suppose that you have an abstract for a scientific paper: we use the field theoretical model to perform relativistic calculations of neutrino energy losses caused by the direct urca processes on nucleons in the degenerate baryon matter . by our analysis ,
the direct neutron decay in the superdense nuclear matter under beta equilibrium is open only due to the isovector meson fields , which create a large energy gap between protons and neutrons in the medium .
our expression for the neutrino energy losses , obtained in the mean field approximation , incorporates the effects of nucleon recoil , parity violation , weak magnetism , and pseudoscalar interaction . for numerical testing of our formula
, we use a self - consistent relativistic model of the multicomponent baryon matter .
the relativistic emissivity of the direct urca reactions is found substantially larger than predicted in the non - relativistic approach .
we found that , due to weak magnetism effects , relativistic emissivities increase by approximately 40 - 50% , while the pseudoscalar interaction only slightly suppresses the energy losses , approximately by 5% . #
1@xmath0#1 psfig.sty .
And you have already written the first three sentences of the full article: modern calculations @xcite based on relativistic equations of state indicate that the neutron star cores consist of neutrons with the admixture of protons , electrons , muons and some exotic particles ( including hyperons , k - mesons , quarks and so on ) .
the composition is governed by the charge neutrality and equilibrium of the medium under weak processes @xmath1 , @xmath2 , where @xmath3 and @xmath4 are baryons ( or quarks ) , and @xmath5 is a lepton , either an electron or a muon .
these reactions , widely known as the direct urca processes , are a central point of any modern scenarios of evolution of neutron stars ..
Please generate the next two sentences of the article | neutrino energy losses caused by the direct urca processes lead to a rapid cooling of degenerate neutron star cores @xcite .
the corresponding reactions on nucleons , @xmath6 , @xmath7 , are the most powerful sources of neutrinos and antineutrinos in cooling neutron stars . in spite of |
7,837 | Suppose that you have an abstract for a scientific paper: we present uniformly measured star formation histories ( sfhs ) of 60 nearby ( @xmath0 @xmath1 4 mpc ) dwarf galaxies based on color - magnitude diagrams of resolved stellar populations from images taken with hubble space telescope and analyzed as part of the acs nearby galaxy survey treasury program ( angst ) .
this volume - limited sample contains 12 dsph / de , 5 dwarf spiral , 28 dirr , 12 dsph / dirr ( transition ) , and 3 tidal dwarf galaxies .
the sample spans a range of @xmath2 10 in @xmath3 and covers a wide range of environments , from highly interacting to truly isolated . from the best fit sfhs we find three significant results : ( 1 ) the average dwarf galaxy formed @xmath4 50% of its stars by z @xmath2 2 and 60% of its stars by z @xmath2 1 , regardless of current morphological type ; ( 2 ) the mean sfhs of dis , dtrans , and dsphs are similar over most of cosmic time , and only begin to diverge a few gyr ago , with the clearest differences between the three appearing during the most recent 1 gyr ; and ( 3 ) the sfhs are complex and the mean values are inconsistent with simple sfh models , e.g. , single bursts , constant sfrs , or smooth , exponentially declining sfrs .
the mean sfhs are in general agreement with the cosmic sfh , although we observe offsets at intermediate times ( z @xmath2 1 ) that could be evidence that low mass systems experienced delayed star formation relative to more massive galaxies .
the sample shows a strong density - morphology relationship , such that the dsphs in the sample are less isolated than dis .
we find that the transition from a gas - rich to gas - poor galaxy can not be solely due to internal mechanisms such as stellar feedback , and instead is likely the result of external mechanisms , e.g. , ram pressure and tidal stripping and tidal forces .
the average transition dwarf galaxy is slightly less isolated and less gas - rich than the typical dwarf irregular .
further , the transition dwarfs can be divided into two groups : interacting and gas -....
And you have already written the first three sentences of the full article: dwarf galaxies have come to play an increasingly important role in understanding how galaxies form and evolve . as the smallest ,
least luminous , and most common systems in the universe , dwarf galaxies span a wide range in physical characteristics and occupy a diverse set of environments ( e.g. , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
7,838 | Suppose that you have an abstract for a scientific paper: we show that for two initially excited qubits , interacting via dipole forces and with a common reservoir , entanglement is preceded by the emergence of quantum and classical correlations . after a time lag ,
entanglement finally starts building up , giving rise to a peculiar entangled state , with very small classical correlations .
different measures of quantum correlations are discussed , and their dynamics are compared and shown to lead to coincident values of these quantifiers for several ranges of time . .
And you have already written the first three sentences of the full article: the characterization of entanglement and the elucidation of its role in quantum computation remain formidable challenges , in spite of the conspicuous presence of this concept in quantum physics since the fundamental and instigating papers published by einstein , podolski , and rosen , as well as schrdinger , in 1935 @xcite .
motivation for the understanding of this subtle concept is stimulated not only by its fundamental character , but also by its applications in quantum information @xcite and , much specially , by the perspective that entanglement could be the key ingredient in the increased efficiency of quantum computing compared to classical computation for certain quantum algorithms @xcite . in an entangled state
, classical and quantum correlations may coexist ..
Please generate the next two sentences of the article | indeed , for instance , in the singlet state @xmath0 there is a perfect classical correlation between the first and the second qubit , namely if the first is in state @xmath1 the second is in state @xmath2 , and vice - versa .
several measures of entanglement have been proposed , like the concurrence @xcite and the negativity @xcite . also , different criteria for the existence of classical correlations have been proposed @xcite . in ref . |
7,839 | Suppose that you have an abstract for a scientific paper: graph analysis is playing an increasingly important role in science and industry . due to numerous limitations in sharing real - world graphs , models for generating massive graphs are critical for developing better algorithms . in this paper
, we analyze the stochastic kronecker graph model ( skg ) , which is the foundation of the graph500 supercomputer benchmark due to its favorable properties and easy parallelization .
our goal is to provide a deeper understanding of the parameters and properties of this model so that its functionality as a benchmark is increased .
we develop a rigorous mathematical analysis that shows this model _ can not _ generate a power - law distribution or even a lognormal distribution . however , we formalize an enhanced version of the skg model that uses random noise for smoothing .
we prove both in theory and in practice that this enhancement leads to a lognormal distribution .
additionally , we provide a precise analysis of isolated vertices , showing that the graphs that are produced by skg might be quite different than intended .
for example , between 50% and 75% of the vertices in the graph500 benchmarks will be isolated .
finally , we show that this model tends to produce extremely small core numbers ( compared to most social networks and other real graphs ) for common parameter choices .
[ complexity measures , performance measures ] [ graphs and networks ] this work was funded by the applied mathematics program at the united states department of energy and performed at sandia national laboratories , a multiprogram laboratory operated by sandia corporation , a wholly owned subsidiary of lockheed martin corporation , for the united states department of energy s national nuclear security administration under contract de - ac04 - 94al85000 .
author s addresses : c. seshadhri , a. pinar , t. kolda , sandia national laboratories , livermore , ca 94551 . .
And you have already written the first three sentences of the full article: the role of graph analysis is becoming increasingly important in science and industry because of the prevalence of graphs in diverse scenarios such as social networks , the web , power grid networks , and even scientific collaboration studies .
massive graphs occur in a variety of situations , and we need to design better and faster algorithms in order to study them
. however , it can be difficult to access to informative large graphs in order to test our algorithms ..
Please generate the next two sentences of the article | companies like netflix , aol , and facebook have vast arrays of data but can not share it due to legal or copyright issues .
moreover , graphs with billions of vertices can not be communicated easily due to their sheer size . as was noted in @xcite , good _ graph models |
7,840 | Suppose that you have an abstract for a scientific paper: we demonstrate that the feedback from stellar bulges can play an essential role in shaping the halo gas of galaxies with substantial bulge components by conducting 1-d hydrodynamical simulations .
the feedback model we consider consists of two distinct phases : 1 ) an early starburst during the bulge formation and 2 ) a subsequent long - lasting mass and energy injection from stellar winds of low - mass stars and type ia sne .
an energetic outward blastwave is initiated by the starburst and is maintained and enhanced by the long - lasting stellar feedback .
for a milky way - like galactic bulge , this blastwave heats up the circum - galactic medium to a scale much beyond the virial radius , thus the gas accretion into the halo can be completely stopped .
in addition to that , the long - lasting feedback in the later phase powers a galactic bulge wind that is reverse - shocked at a large radius in the presence of circum - galactic medium and hence maintains a hot gaseous halo .
as the mass and energy injection decreases with time , the feedback evolves to a subsonic and quasi - stable outflow , which is enough to prevent halo gas from cooling .
the two phases of the feedback thus re - enforce each - other s impact on the gas dynamics .
the simulation results demonstrate that the stellar bulge feedback may provide a plausible solution to the long - standing problems in understanding the milky - way type galaxies , such as the `` missing stellar feedback '' problem and the `` over - cooling '' problem .
the central point of the present model is that the conspiracy of the two - phase feedback keeps a low density and a high temperature for the circum - galactic medium so that its x - ray emission is significantly lowered and the radiative cooling is largely suppressed .
the simulations also show that the properties of the hot gas in the subsonic outflow state depend sensitively on the environment and the formation history of the bulge .
this dependence and variance may explain the large....
And you have already written the first three sentences of the full article: it is believed that galaxies form in dark matter halos , which grow through gravitational instability from the density fluctuations seeded in the early universe .
the baryonic matter is then accreted into the dark matter halos and cools radiatively to assemble galaxies .
although the structure and the evolution of dark matter halos are fairly well understood with the use of analytic modeling @xcite and @xmath1-body simulations @xcite , galaxy formation still remains a challenging problem as it is a complex process involving simultaneous actions of many physical mechanisms ..
Please generate the next two sentences of the article | one of the long - standing problems in galaxy formation is that , in the absence of heating sources , the majority of baryonic matter in the universe is predicted to have cooled into dark matter halos by the present time ( e.g. @xcite ) , while in reality only a small fraction of the baryonic matter associated with galaxies is observed in the cold ( stars plus cold gas ) phase ( @xcite ) .
this `` over - cooling '' problem implies that feedback must have played a very important role in shaping galaxies . |
7,841 | Suppose that you have an abstract for a scientific paper: we report the successful substitution of cobalt , nickel , and copper for iron in the 1038 phase parent compound ca@xmath0(feas)@xmath0(pt@xmath1as@xmath2 ) yielding ca@xmath0(fe@xmath3co@xmath4as)@xmath0(pt@xmath1as@xmath2 ) , ca@xmath0(fe@xmath3ni@xmath4as)@xmath0(pt@xmath1as@xmath2 ) , and ca@xmath0(fe@xmath3cu@xmath4as)@xmath0(pt@xmath1as@xmath2 ) , respectively .
superconductivity is induced in co and ni doped compounds reaching critical temperatures up to 15 k , similar to known pt substituted ca@xmath0(fe@xmath3pt@xmath4as)@xmath0(pt@xmath1as@xmath2 ) , whereas no superconductivity was detected in ca@xmath0(fe@xmath3cu@xmath4as)@xmath0(pt@xmath1as@xmath2 ) .
the obtained @xmath5 phase diagrams are very similar to those of other iron arsenide superconductors indicating rather universal behaviour despite the more complex structures of the 1038-type compounds , where the physics is primarily determined by the feas layer .
superconductivity , iron arsenides , doping , crystal structure , platinum , cobalt , nickel , copper .
And you have already written the first three sentences of the full article: superconductivity in iron arsenides emerges from antiferromagnetic metallic parent compounds in the course of suppressing the magnetic ordering by chemical doping or pressure @xcite , resulting critical temperatures ( @xmath6 ) up to 55 k in sm(o@xmath3f@xmath4)feas @xcite .
relationships between the magneto - structural phase transition and superconductivity in iron arsenides have intensively been studied @xcite . in 2011 the new superconductors ca@xmath0(fe@xmath3pt@xmath4as)@xmath0(pt@xmath1as@xmath2 ) ( 1038 phase , space group @xmath7 ) and polymorphic ca@xmath0(feas)@xmath0(pt@xmath8as@xmath2 ) ( 1048-phases , space groups @xmath9 , @xmath10 , @xmath7 ) with critical temperatures up to 35 k were discovered @xcite .
this new class recently expanded by analogous compounds with iridium ( ir1048 ) @xcite and palladium ( pd1038 ) @xcite instead of platinum . due to the presence of the second metal pnictide layer pt@xmath11as@xmath2 ( @xmath12 = 3 , 4 ) next to feas , as well as the low symmetry of these compounds ( space group @xmath7 ) they were initially considered as rather peculiar representatives of the iron arsenide family ..
Please generate the next two sentences of the article | recent low temperature x - ray structural data together with @xmath13sr spectra @xcite as well as neutron diffraction @xcite revealed a lattice distortion and magnetic phase transition at 120 k , proving that ca@xmath0(feas)@xmath0(pt@xmath1as@xmath2 ) is the parent compound of this branch of the iron arsenide family . thereby closely related superconductors like ca@xmath0(fe@xmath3pt@xmath4as)@xmath0(pt@xmath1as@xmath2 ) ( @xmath14 = 14 k ) , ca@xmath0(feas)@xmath0(pt@xmath8as@xmath2 ) ( @xmath14 = 35 k ) and ( ca@xmath15)@xmath0(feas)@xmath0(pt@xmath1as@xmath2 ) ( @xmath14 = 35 k ) can be derived from this common parent by direct , indirect , and electronic doping , respectively @xcite .
[ fig : structure ] depicts the structure of the 1038 parent compound as well as a section of the pt@xmath1as@xmath2 layer . |
7,842 | Suppose that you have an abstract for a scientific paper: parity violating ( pv ) contributions due to interference between @xmath0 and @xmath1 exchange are calculated for pion electroproduction off the nucleon . a phenomenological model with effective lagrangians
is used to determine the resulting asymmetry for the energy region between threshold and @xmath2 resonance .
the @xmath3 resonance is treated as a rarita - schwinger field with phenomenological @xmath4 transition currents .
the background contributions are given by the usual born terms using the pseudovector @xmath5 lagrangian .
numerical results for the asymmetry are presented .
+ + pacs numbers : 25.30.rw , 13.10.+q .
And you have already written the first three sentences of the full article: the study of the electroweak interaction between leptons and hadrons has been a challenging topic ever since the standard model was proposed by glashow , salam and weinberg .
this model predicts the coupling of the electroweak currents to leptons and quarks in terms of the electric charge @xmath6 and the weinberg angle @xmath7 . in particular , the weak neutral current is mediated by the exchange of the @xmath1 gauge boson . at
low and moderate momentum transfer its contribution is suppressed relative to photon exchange by a factor @xmath8 , where @xmath9 is the four - momentum of the exchanged boson and @xmath10 the mass of the @xmath1 . the interference term beween photon and @xmath1 exchange.
Please generate the next two sentences of the article | contains a parity violating ( pv ) effect , which becomes visible as an asymmetry by scattering polarized electrons with helicity along the direction of the beam @xmath11 or opposite to it @xmath12 , @xmath13 the quantity @xmath14 in this equation should represent an inclusive cross section . in the case of a coincidence experiment , e.g. @xmath15 , there also appear parity conserving asymmetries due to the electromagnetic interaction .
specifically , the so - called 5th response function will generate a background of helicity - dependent contributions , which are parity conserving and , therefore , generally larger than the pv effects by several orders of magnitude . |
7,843 | Suppose that you have an abstract for a scientific paper: the spatially flat friedman - robertson - walker ( frw ) cosmological model with a massless scalar field in loop quantum cosmology admits a description in terms of a completely solvable model . this has been used to prove that : i ) the quantum bounce that replaces the big bang singularity is generic ; ii ) there is an upper bound on the energy density for all states and iii ) semiclassical states at late times had to be semiclassical before the bounce .
here we consider a family of exact solutions to the theory , corresponding to generalized coherent gaussian and squeezed states .
we analyze the behavior of basic physical observables and impose restrictions on the states based on physical considerations .
these turn out to be enough to select , from all the generalized coherent states , those that behave semiclassical at late times .
we study then the properties of such states near the bounce where the most ` quantum behavior ' is expected . as it turns out ,
the states remain sharply peaked and semiclassical _ at the bounce _ and the dynamics is very well approximated by the ` effective theory ' throughout the time evolution .
we compare the semiclassicality properties of squeezed states to those of the gaussian semiclassical states and conclude that the gaussians are better behaved . in particular , the asymmetry in the relative fluctuations before and after the bounce are negligible , thus ruling out claims of so called ` cosmic forgetfulness ' . .
And you have already written the first three sentences of the full article: loop quantum cosmology has provided in past years a useful framework to ask questions about the quantum nature of the early universe @xcite . closely related to loop quantum gravity @xcite ,
the formalism has shown that , for isotropic models , the big bang singularity is replaced by a quantum bounce @xcite .
these results have been obtained for closed and open frw cosmologies @xcite with and without a cosmological constant @xcite for a massless scalar field , and recently extended to the massive case @xcite ..
Please generate the next two sentences of the article | recently , some of these results have been extended to anisotropic @xcite and some inhomogeneous models @xcite . in all these cases , quantum gravitational effects
have been shown to exert a repulsive force and halt the collapse and launch an expanding superinflationary phase before the quantum gravity effects die out and the universe then follows the standard general relativity ( gr ) dynamics . an exactly solvable model for the @xmath0=0 frw with a massless scalar field has allowed to prove analytically the generic nature of the quantum bounce @xcite . in particular , it was shown that the bounce occurs for all physical states , and the energy density possesses a supremum for physical states @xcite . regarding the fluctuations |
7,844 | Suppose that you have an abstract for a scientific paper: we report the results of a survey of the galactic center region ( @xmath0 , @xmath1 ) performed with the @xmath2 satellite .
the flux from the center of our galaxy corresponds to a luminosity of @xmath33 10@xmath4 erg s@xmath5 in the 210 kev range .
due to the limited angular resolution ( @xmath6 ) only part of it is supposed to come from sagittarius a * , the non thermal radio source which is believed to mark the dynamical center of the galaxy .
in addition to the diffuse emission , several bright ( l@xmath7 ergs s@xmath5 ) point sources have been observed , both persistent ( a 1742294 , slx 1744299 , slx 1744300 , 1e 1743.12843 , 1e 1740.72942 ) and transient ( xte j1748288 , sax j1747.02853 and ks 1741293 ) . the low mass x
ray binary ax j1745.62901 , discovered with asca at only @xmath8 from sgra * was detected in a low luminosity state in august 1997 .
the 1150 kev spectrum of the hard x ray source 1e 1740.72942 is well described by a comptonization model , typical of black hole candidates in their low / hard state , with no evidence for strong fe lines .
the detection of a type i burst shows that the transient source sax j1747.02853 ( probably the same as the 1976 transient gx 0.20.2 ) is a lmxrb containing a neutron star . the transient black hole candidate xte j1748288 was detected at a luminosity ( @xmath9 ergs s@xmath5 ) consistent with the extrapolation of the exponential decay of the outburst observed with the xte all sky monitor .
two fainter sources are very likely associated with young neutron stars : the ( possibly diffuse ) x ray source at the center of the composite supernova remnant g0.9 + 0.1 , and the head " of the axially symmetric radio source g359.230.92 .
the latter has been detected above @xmath3 6 kev , supporting a non thermal emission mechanism . #
1to 0pt#1 # 1#2d # 1 d # 2 #1_#1 #1 # 2 a&a , # 1 , # 2 # 1 # 2 mnras , # 1 , # 2 # 1 # 2 apj , # 1 , # 2 # 1 # 2 nature , # 1 , # 2 # 1 # 2 pasj , # 1 , # 2 .
And you have already written the first three sentences of the full article: the galactic center ( hereafter gc ) region has been observed at different spatial scales and energy bands by many x ray missions .
the main results in the 0.510 kev range have been obtained with the einstein observatory ( watson et al . , 1981 ) , rosat ( predehl & trumper , 1994 ) and , more recently , with asca ( maeda et al . 1996 , 1998 ; koyama et al .
1996 ) . at higher energies , the telescopes art .
Please generate the next two sentences of the article | p ( pavlinsky , grebenev & sunyaev 1994 ) and sigma ( goldwurm et al . 1994 ) on board the granat satellite performed a monitoring of the gc region leading to the discovery of many new sources .
these observations have shown that the gc x ray emission comes both from point sources and from a diffuse component . within a few degrees from the direction of the gc region |
7,845 | Suppose that you have an abstract for a scientific paper: we propose a generalization of the supersymmetric representation of spins with symplectic symmetry , generalizing the rotation group of the spin from @xmath0 to @xmath1 . as a test application of this new representation , we consider two toy models involving a competition of the kondo effect and antiferromagnetism : a two - impurity model and a frustrated three - impurity model .
exploring an ensemble of l - shaped representations with a fixed number of boxes in their respective young tableaux , we allow the system to choose which representation is energetically more favorable in each region in parameter space .
we discuss how the features of these preliminary applications can generalize to kondo lattice models . .
And you have already written the first three sentences of the full article: heavy fermion materials involve a lattice of localized magnetic moments derived from f - electrons , embedded in a conduction sea formed principally from delocalized d - electrons @xcite .
the physics of these materials can be understood as a consequence of the interplay between two competing physical processes : * the kondo effect , which tends to screen the local moments to produce a band of heavy electrons , and * antiferromagnetism , which locks the local moments together via the rkky interaction , into a state with long range magnetic order .
the characteristic scales for these two processes are @xmath2 where @xmath3 is the strength of the onsite kondo interaction between the localized f - electrons and conduction electrons , @xmath4 is the density of states of the conduction electrons at the fermi energy and @xmath5 the bandwidth ..
Please generate the next two sentences of the article | the kondo temperature , @xmath6 , sets the energy scale for the onset of the kondo effect and consequently the formation of a coherent heavy fermi liquid ( hfl ) while @xmath7 defines the energy scale for the onset of magnetic order .
the family of heavy fermion materials provides an important setting for the study of quantum criticality @xcite which develops when a continuous second - order phase transition is suppressed to absolute zero temperature . |
7,846 | Suppose that you have an abstract for a scientific paper: within the context of semiquantum nonlocal games , the trust can be removed from the measurement devices in an entanglement - detection procedure . here
we show that a similar approach can be taken to quantify the amount of entanglement . to be specific , first
, we show that in this context a small subset of semiquantum nonlocal games is necessary and sufficient for entanglement detection in the locc paradigm .
second , we prove that the maximum pay - off for these games is a universal measure of entanglement which is convex and continuous .
third , we show that for the quantification of negative - partial - transpose entanglement , this subset can be further reduced down to a single arbitrary element .
importantly , our measure is operationally accessible in a measurement - device - independent way by construction .
finally , our approach is simply extended to quantify the entanglement within any partitioning of multipartite quantum states .
[ [ introduction . ] ] introduction. + + + + + + + + + + + + + + entanglement is a valuable resource for practical as well as fundamental applications of quantum theory , ranging from quantum computation and communication to metrology @xcite .
there are two major challenges in understanding entanglement that stimulates this research .
it is extremely difficult to specify all the nonentangled bipartite or multipartite quantum states .
in fact , the problem is known to be np - hard @xcite .
not surprisingly , the characterization of entangled states is an equally difficult task .
that is , to quantify the amount of entanglement within a quantum state .
the answer to this question is practically very important , because it tells us how well our protocols will perform using a given state @xcite .
recent work by buscemi @xcite has introduced a new way to think about entanglement detection @xcite .
the idea is to map the problem onto a modified class of nonlocal games , called semiquantum nonlocal games ( sqnlgs ) . in any such....
And you have already written the first three sentences of the full article: note that , in general , @xmath119 .
now , the maximization for @xmath120 in eq . can be obtained by choosing the povms @xmath121 and @xmath122 to be the projections onto @xmath123 , and @xmath1 to be the transpose of the extremal point of @xmath38 , @xmath124 , which gives @xmath125 .
thus , by making use of eq . , we obtain @xmath126 ..
Please generate the next two sentences of the article | it is sufficient to prove that a quantum state @xmath127 if and only if @xmath128 . the proof is as follows . for any state @xmath1 , we can write @xmath129 to prove the necessary part , we note that for every separable state @xmath130 , the right - hand - side of eq .
is just zero by using eq . . |
7,847 | Suppose that you have an abstract for a scientific paper: we present an approximation scheme for the dielectric response of thermal collisionless plasmas at arbitrary degeneracy .
a t - fraction representation is obtained from the known expansions of the real part of the dielectric function for small and large arguments .
the partial numerators and denominators of the continued fraction are generated by a modified q - d algorithm . for several typical values of the degeneracy parameter @xmath0 , extensive tables for the expansion coefficients and the partial numerators and denominations
are given allowing for an easy implementation of the fitting function . also , an error analysis is performed . .
And you have already written the first three sentences of the full article: the dielectric response of a collisionless plasma is an ubiquitous quantity in plasma physics and in the many - body theory of coulomb systems in general . for a fermionic system ,
it was first derived by lindhard @xcite and is closely related to the dielectric function @xmath1 in random phase approximation @xcite . in this way ,
the dielectric response is connected to collective effects such as screening , plasmons , and landau damping ..
Please generate the next two sentences of the article | its knowledge is also important for non - ideal plasmas , since the effects of non - ideality are typically parameterized by dynamic local field corrections with respect to the ideal response @xcite .
a detailed study of the ideal dielectric response for fermionic systems has been reported by arista and brandt @xcite . here |
7,848 | Suppose that you have an abstract for a scientific paper: we discuss the possibility that a sterile neutrino of mass around @xmath0 mev slightly mixed with the muon flavor may be the origin of the miniboone anomaly .
we show that its production in the atmosphere in a fraction of kaon decays would imply an excess of contained showers at icecube from down - going and near - horizontal directions .
* a sterile neutrino at miniboone and icecube * manuel masip _ cafpe and departamento de fsica terica y del cosmos _ + _ universidad de granada , 18071 granada , spain _ + ` [email protected] ` .
And you have already written the first three sentences of the full article: during the past 20 years a number of experiments with solar , atmospheric , reactor and baseline neutrinos have shown that neutrinos have masses and mixings @xcite .
these experiments provide a framework with @xmath1 that fits remarkably well most of the data . from a model - building point of view the importance of this discovery
can not be overstated ..
Please generate the next two sentences of the article | we should , however , keep in mind that * there are some very basic questions with no answer yet .
we do not know , in particular , if these masses are purely electroweak ( ew ) ( just like the electron mass ) or if neutrinos are majorana fermions and their mass is revealing a new scale in particle physics ( like radiactivity reveals the ew scale ) : @xmath2 * there has been a _ persistent _ anomaly in several experiments with neutrino beams from particle accelerators . namely , lsnd @xcite and miniboone @xcite have observed an excess of @xmath3 events with an electron in the final state per each 1000 @xmath4 charged - current ( cc ) interactions . |
7,849 | Suppose that you have an abstract for a scientific paper: we present electron spin resonance ( esr ) investigation of the acentric ba@xmath0nbfe@xmath0si@xmath1o@xmath2 , featuring a unique single - domain double - chiral magnetic ground state .
combining simulations of the esr line - width anisotropy and the antiferromagnetic - resonance modes allows us to single out the dzyaloshinsky - moriya ( dm ) interaction as the leading magnetic anisotropy term .
we demonstrate that the rather minute out - of - plane dm component @xmath3 mk is responsible for selecting a unique ground state , which endures thermal fluctuations up to astonishingly high temperatures .
spin - orbit coupling generally has no relevant effect in ordinary magnets , except to pin the orientation of spins with respect to the background lattice in magnetically ordered phases , singled out by the isotropic heisenberg exchange interactions .
an exception is provided on geometrically frustrated lattices where the isotropic interactions alone are often unable to raise the macroscopic degeneracy of a ground state ( gs ) @xcite , leading to unconventional cooperative electronic states @xcite .
then , the magnetic behavior might be exclusively driven by minute perturbing terms in the form of anisotropic interactions emanating from the spin - orbit coupling .
for instance , the antisymmetric dzyaloshinsky - moriya ( dm ) exchange interaction @xcite can induce order on a kagom lattice in the classical limit @xcite and can lead to quantum criticality in the quantum limit @xcite .
furthermore , dm is known to alter phase diagrams of frustrated ladders @xcite and triangular lattices @xcite .
it is also responsible for spin chirality @xcite that can be long - ranged even in the absence of a classical magnetic order @xcite .
spin chirality is one of the key concepts in the physics of strongly correlated electrons , as it is related to various intriguing phenomena , like the realization of spin liquids @xcite , magnetic - order induced ferroelectricity @xcite , anomalous hall effect @xcite and....
And you have already written the first three sentences of the full article: in the linear response theory an electron spin resonance ( esr ) spectrum is given by the fourier transform of the relaxation function @xcite @xmath109 where @xmath110 are transverse magnetization operators and @xmath111 denotes canonical averaging .
line position ( @xmath29-value ) and line width of the spectrum contain important information on local anisotropies @xcite .
the principal axes of the @xmath29-tensor are set by a local symmetry of the crystal field . in bnfso one of the principal axes ( labeled @xmath14 ).
Please generate the next two sentences of the article | is parallel to a two - fold rotational axis passing through the center of each feo@xmath112 tetrahedron , while the other two ( labeled @xmath38 and @xmath37 ) are parallel with the two normals to the o@xmath113-fe - o@xmath113 planes , @xmath114 labeling two pairs of oxygens at a distance of 1.909 and 1.856 from fe , respectively . for site 2 ( see fig . [ fig1s ] and fig . 1 of the main text )
the @xmath14 axis corresponds to the crystallographic @xmath36 direction , while @xmath37 and @xmath38 axes are tilted by @xmath39 and 120@xmath40 from the @xmath115 axis in the crystallographic @xmath42 plane . |
7,850 | Suppose that you have an abstract for a scientific paper: in the face of serious infectious diseases , governments endeavour to implement containment measures such as public vaccination at a macroscopic level .
meanwhile , individuals tend to protect themselves by avoiding contacts with infections at a microscopic level . however , a comprehensive understanding of how such combined strategy influences epidemic dynamics is still lacking .
we study a susceptible - infected - susceptible epidemic model with imperfect vaccination on dynamic contact networks , where the macroscopic intervention is represented by random vaccination of the population and the microscopic protection is characterised by susceptible individuals rewiring contacts from infective neighbours . in particular , the model is formulated both in populations without and then with demographic effects ( births , deaths , and migration ) . using the pairwise approximation and the probability generating function approach , we investigate both dynamics of the epidemic and the underlying network . for populations without demography , the emerging degree correlations , bistable states , and oscillations demonstrate the combined effects of the public vaccination program and individual protective behavior . compared to either strategy in isolation , the combination of public vaccination and individual protection is more effective in preventing and controlling the spread of infectious diseases by increasing both the invasion threshold and the persistence threshold . for populations with additional demographic factors ,
we investigate temporal evolution of infected individuals and infectious contacts , as well as degree distributions of nodes in each class .
it is found that the disease spreads faster but is more restricted in scale - free networks than in the erds - rnyi ones .
the integration between vaccination intervention and individual rewiring may promote epidemic spreading due to the birth effect .
moreover , the degree distributions of both networks in the steady state is closely related to....
And you have already written the first three sentences of the full article: since complex network models @xcite were applied to mathematical epidemiology @xcite in such a way that the host population is modelled as a contact network where nodes represent individuals and links stand for contacts among them the topological structure of the underlying network has shown a strong impact on the spread of infectious diseases @xcite .
for instance , based on mean - field approximations , @xcite suggested that there is no typical epidemic threshold in a scale - free ( sf ) network which follows a power - law degree distribution @xmath0 with the power exponent @xmath1 in the thermodynamic limit .
otherwise , there is a positive critical value @xmath2 of the transmission rate @xmath3 only for @xmath4 ..
Please generate the next two sentences of the article | it is worth remarking that in a more mathematically rigorous analysis , @xcite proved that the critical value @xmath2 is also zero for contact processes on random networks with power - law degree distributions for any power exponent @xmath4 . in other words
, the infection can pervade the whole sf network provided the transmission rate is nonzero . over the past decades |
7,851 | Suppose that you have an abstract for a scientific paper: we determine the optimal bound for the maximum number of moves required to reach a periodic configuration of _ open mancala _
( also called open owari ) , inspired by a popular african game .
a mancala move can be interpreted as a map from the set of compositions of a given integer in itself , thus relating our result to the study of the corresponding finite dynamical system . .
And you have already written the first three sentences of the full article: _ mancala _ is a family of traditional african games played in many versions and under many names .
it comprises a circular list of _ holes _ containing zero or more _ seeds_. a move consists of selecting a nonempty hole , taking all its seeds and _ sowing _ them in the subsequent holes , one seed per hole .
here we study an idealized version of this called _ open mancala _ ( see @xcite , where the game is called _ open owari _ ) ..
Please generate the next two sentences of the article | we assume there is an infinite sequence of holes .
further we assume that the nonempty holes are consecutive ; such a configuration is described by a sequence of positive integers @xmath0 , @xmath1 , giving the number of seeds in each nonempty hole , starting from the leftmost one . |
7,852 | Suppose that you have an abstract for a scientific paper: we present a technique to identify optical counterparts of 250@xmath0m - selected sources from the _ herschel_-atlas survey . of the 6621 250@xmath0 m @xmath1mjy sources in our science demonstration catalogue
we find that @xmath2 percent have counterparts brighter than @xmath3mag in the sloan digital sky survey . applying a likelihood ratio technique
we are able to identify 2423 of the counterparts with a reliability @xmath4 .
this is approximately 37 percent of the full 250@xmath0 m catalogue .
we have estimated photometric redshifts for each of these 2423 reliable counterparts , while 1099 also have spectroscopic redshifts collated from several different sources , including the gama survey .
we estimate the completeness of identifying counterparts as a function of redshift , and present evidence that 250@xmath0m - selected _ herschel_-atlas galaxies have a bimodal redshift distribution .
those with reliable optical identifications have a redshift distribution peaking at @xmath5 , while sub - mm colours suggest that a significant fraction with no counterpart above the r - band limit have @xmath6 .
we also suggest a method for selecting populations of strongly - lensed high redshift galaxies .
our identifications are matched to uv
nir photometry from the gama survey , and these data are available as part of the _ herschel_-atlas public data release .
[ firstpage ] galaxies : local , galaxies : infrared , galaxies : star - forming , methods : statistical , submillimetre : galaxies .
And you have already written the first three sentences of the full article: one of the key problems to overcome when conducting multi - wavelength surveys is determining which sources are associated with one another in different wave - bands , and which are unrelated .
when multiple observations have been conducted at similar wavelengths and with similar resolution and sensitivity , this problem can be reliably addressed by using a simple nearest neighbour match . however , in the situation where the two distinct sets of observations to be matched have considerably different resolution for example matching far - infrared or sub - millimetre survey data to an optical catalogue ( e.g. sutherland et al . , 1991 , clements et al . , 1996 ,
serjeant et al . , 2003 , clements et al . , 2004 , ivison et al ..
Please generate the next two sentences of the article | 2005 , 2007 , wang & rowan - robinson , 2009 , biggs et al .
2010 ) the large positional uncertainties in the longer - wavelength data can make it much more difficult to find reliable associations between sub millimetre sources and their optical / near infrared counterparts . |
7,853 | Suppose that you have an abstract for a scientific paper: we show that in a large class of supersymmetric models with spontaneously broken @xmath0 symmetry , neutron
antineutron oscillations occur at an observable level even though the scale of @xmath0 breaking is very high , @xmath1 gev , as suggested by gauge coupling unification and neutrino masses .
we illustrate this phenomenon in the context of a recently proposed class of seesaw models that solves the strong cp problem and the susy phase problem using parity symmetry .
we obtain an _ upper _ limit on @xmath2 oscillation time in these models , @xmath3 sec .
this suggests that a modest improvement in the current limit on @xmath4 of @xmath5 sec will either lead to the discovery of @xmath2 oscillations , or will considerably restrict the allowed parameter space of an interesting class of neutrino mass models .
epsf.tex ( # 1 width # 2)=#2 .
And you have already written the first three sentences of the full article: it is widely believed that the most natural and appealing explanation of the recent neutrino oscillation results is provided by the seesaw mechanism @xcite incorporated into extensions of the standard model that include a local @xmath0 symmetry .
the simplest models with local @xmath0 symmetry are the left - right symmetric models @xcite based on the gauge group @xmath6 .
these models have the additional virtue that they explain the origin of parity violation in weak interactions as a consequence of spontaneous symmetry breaking in very much the same way as one explains the strength of the weak interaction in the standard model ..
Please generate the next two sentences of the article | stability of the higgs sector under radiative corrections calls for weak scale supersymmetry as in the minimal supersymmetric standard model ( mssm ) .
it has recently been shown that if the mssm is embedded into a left |
7,854 | Suppose that you have an abstract for a scientific paper: stellar black hole ( bh ) binaries are one of the most promising gravitational wave ( gw ) sources for gw detection by the ground - based detectors .
nuclear star clusters ( ncs ) located at the centre of galaxies are known to harbour massive black holes ( mbhs ) and to be bounded by a gravitational potential by other galactic components such as the galactic bulge .
such an environment of ncs provides a favourable conditions for the bh - bh binary formation by the gravitational radiation capture due to the high bh number density and velocity dispersion .
we carried out detailed numerical study of the formation of bh binaries in the ncs using a series of n - body simulations for equal - mass cases .
there is no mass segregation introduced .
we have derived scaling relations of the binary formation rate with the velocity dispersion of the stellar system beyond the radius of influence and made estimates of the rate of formation of black hole binaries per unit comoving volume and thus expected detection rate by integrating the binary formation rate over galaxy population within the detection distance of the advanced detectors .
we find that the overall formation rates for bh - bh binaries per nc is @xmath0 for the milky - way - like galaxies and weakly dependent on the mass of mbh as @xmath1 @xmath2 .
we estimate the detection rate of 0.02 - 14 yr@xmath3 for advanced ligo / virgo considering several factors such as the dynamical evolution of ncs , the variance of the number density of stars and the mass range of mbh giving uncertainties .
[ firstpage ] gravitational waves methods : numerical galaxies : nuclei . .
And you have already written the first three sentences of the full article: the gravitational wave ( gw ) is the propagation of ripples of the space - time curvature with speed of light .
although @xcite predicted the existence of gravitational radiation ( gr ) , the gws have never been directly detected yet . from 30 years observations , @xcite found that the binary pulsar psr 1913 + 16 , discovered by @xcite , exhibited the decrease of the orbital period and the amount of decrease exactly coincide with the prediction of general relativity .
there are several types of astronomical objects that can produce significant amount of gravitational waves : core - collapse supernovae , spinning neutron stars ( e.g. , * ? ? ?.
Please generate the next two sentences of the article | * ) , compact binary coalescences ( e.g. , * ? ? ?
* ) , supermassive black holes ( smbh ) ( e.g. , binary smbh merger , * ? ? ? |
7,855 | Suppose that you have an abstract for a scientific paper: data on inclusive pion and eta production measured with the dielectron spectrometer hades in the reaction p+@xmath0nb at a kinetic beam energy of 3.5 gev are presented .
our results , obtained with the photon - conversion method , supplement the rather sparse information on neutral - meson production in proton - nucleus reactions existing for this bombarding energy regime .
the reconstructed e@xmath1e@xmath2e@xmath1e@xmath2 transverse - momentum and rapidity distributions are confronted with transport - model calculations , which account fairly well for both @xmath3 and @xmath4 production . .
And you have already written the first three sentences of the full article: the high - acceptance dielectron spectrometer ( hades ) experiment at gsi pursues a comprehensive program of dielectron emission studies in few - gevnucleon - nucleon @xcite , proton - nucleus @xcite , and nucleus - nucleus collisions @xcite .
dilepton spectroscopy allows to investigate the properties of hadrons produced , propagated , and decayed in a strongly interacting medium .
this is because leptons ( electrons and muons ) do not themselves interact strongly when traveling through finite - sized hadronic matter , that is , their kinematics remain basically undistorted ..
Please generate the next two sentences of the article | lepton - pair measurements are hence ideally suited to search for medium modifications of hadrons in nuclear matter @xcite .
the observed dilepton spectra consist , however , of a complex superposition of various mesonic and baryonic contributions , and their interpretation requires a detailed knowledge of all sources . |
7,856 | Suppose that you have an abstract for a scientific paper: the accelerated expansion of the universe has now been confirmed by several independent observations including those of high redshift type ia supernovae , and the cosmic microwave background combined with the large scale structure of the universe .
another way of presenting this kinematic property of the universe is to postulate the existence of a new and exotic entity , with negative pressure , the dark energy ( de ) . in spite of observationally
well established , no single theoretical model provides an entirely compelling framework within which cosmic acceleration or de can be understood . at present
all existing observational data are in agreement with the simplest possibility of the cosmological constant to be a candidate for de .
this case is internally self - consistent and non - contradictory .
the extreme smallness of the cosmological constant expressed in either planck , or even atomic units means only that its origin is not related to strong , electromagnetic and weak interactions .
although in this case de reduces to only a single fundamental constant we still have no derivation from any underlying quantum field theory for its small value . from the principles of quantum cosmologies , it is possible to obtain the reason for an inverse - square law for the cosmological constant with no conflict with observations .
despite the fact that this general expression is well known , in this work we introduce families of analytical solutions for the scale factor different from the current literature .
the knowledge of the scale factor behavior might shed some light on these questions since the entire evolution of a homogeneous isotropic universe is contained in the scale factor .
we use different parameters for these solutions and with these parameters we stablish a connection with the equation of state for different dark energy scenarios .
.2 in .
And you have already written the first three sentences of the full article: the research about the cosmological scale factor has attracted intense attention during the last years as well as the investigation about the connection between the cosmological constant and the dark energy issue . as the vacuum has a non - trivial role in the early universe ,
a @xmath0-term in the einstein field equations is generated .
this @xmath0-term leads to the inflationary phase @xcite ..
Please generate the next two sentences of the article | based on the inflationary cosmology we can say that during an early exponential phase , the vacuum energy was a large cosmological constant .
however , the current observed small value of the cosmological constant makes us to assume that @xmath0 , representing the energy density of the vacuum , is a variable dynamic degree of freedom which being initially very large went down to its small present value in an expanding universe @xcite . |
7,857 | Suppose that you have an abstract for a scientific paper: intense beams of cold and slow molecules are produced by supersonic expansion out of a rapidly rotating nozzle , as first demonstrated by gupta and herschbach @xcite .
an improved setup is presented that allows to accelerate or decelerate cold atomic and molecular beams by up to 500 m/s .
technical improvements are discussed and beam parameters are characterized by detailed analysis of time of flight density distributions . the possibility of combining this beam source with electrostatic fields for guiding polar molecules is demonstrated . .
And you have already written the first three sentences of the full article: cold molecules currently attract great attention due to their potential application for precision measurements @xcite , quantum information schemes @xcite , degenerate quantum gases with complex interactions @xcite , and for cold chemistry @xcite . besides the approach of forming cold molecules out of a sample of ultracold trapped atoms @xcite , recent experimental efforts mainly focus on developing techniques of slowing or filtering , cooling , and trapping molecules produced in effusive or nozzle beams .
well established techniques are buffer gas cooling @xcite , the deceleration of beams of polar molecules using time - varying electric fields @xcite , as well as filtering of polar molecules out of an effusive source using static or time - varying electric fields @xcite .
recently , the method of decelerating supersonic molecular beams has been extended to magnetic @xcite and optical fields @xcite ..
Please generate the next two sentences of the article | alternative routes to producing cold molecules have been demonstrated utilizing the kinematics in elastically or reactively colliding molecular beams @xcite .
furthermore , producing beams of slow and cold atoms and molecules by mechanical means has been demonstrated @xcite . in particular the technique of translating a supersonic jet to low longitudinal velocities by means of a rapidly counter - rotating nozzle , pioneered by gupta and herschbach , |
7,858 | Suppose that you have an abstract for a scientific paper: we show that ( a ) the conformal properties of anti - de sitter ( ads ) space , ( b ) the properties of a field theory in one dimension under the full conformal group found by de alfaro , fubini and furlan , and ( c ) the frame - independent single - variable light - front schrdinger equation for bound states all lead to the same result : a relativistic nonperturbative model which successfully incorporates salient features of hadronic physics , including confinement , linear regge trajectories , and results which are conventionally attributed to spontaneous chiral symmetry breaking . .
And you have already written the first three sentences of the full article: one of the most intriguing features of qcd for massless quarks is its underlying conformal invariance , invariance under both scale ( dilatation ) and special conformal transformations @xcite .
for example , in the case of perturbative qcd , the running coupling @xmath0 becomes constant in the limit of zero @xmath1-function and zero quark mass , and conformal symmetry becomes manifest .
in fact , the renormalization scale uncertainty in pqcd predictions can be eliminated by using the principle of maximum conformality ( pmc ) @xcite . using the pmc / blm procedure @xcite , all non -.
Please generate the next two sentences of the article | conformal contributions in the perturbative expansion series are summed into the running coupling by shifting the renormalization scale in @xmath2 from its initial value , and one obtains unique , scale - fixed , scheme - independent predictions at any finite order .
one can also introduce a generalization of conventional dimensional regularization which illuminates the renormalization scheme and scale ambiguities of pqcd predictions , exposes the general pattern of nonconformal terms , and allows one to systematically determine the argument of the running coupling order by order in pqcd in a form which can be readily automatized @xcite . |
7,859 | Suppose that you have an abstract for a scientific paper: recent work for single - relay channels shows that quantize - forward ( qf ) with long - message encoding achieves the same reliable rates as compress - forward ( cf ) with short - message encoding .
it is shown that short - message qf with backward or pipelined ( sliding - window ) decoding also achieves the same rates .
similarly , for many relays and sources , short - message qf with backward decoding achieves the same rates as long - message qf .
several practical advantages of short - message encoding are pointed out , e.g. , reduced delay and simpler modulation .
furthermore , short - message encoding lets relays use decode - forward ( df ) if their channel quality is good , thereby enabling multi - input , multi - output ( mimo ) gains that are not possible with long - message encoding . finally , one may combine the advantages of long- and short - message encoding by hashing a long message to short messages . .
And you have already written the first three sentences of the full article: relaying is receiving attention for wireless cellular applications because it improves rates and reliabilities .
there are two simple geometric scenarios that give insight into relaying strategies , and that show how relaying achieves distributed multi - input , multi - output ( mimo ) gains @xcite .
first , relays that are close to a source node can achieve multi - input " gains by using a decode - forward ( df ) strategy ..
Please generate the next two sentences of the article | second , relays that are close to a destination node can achieve multi - output " gains by using a compress - forward ( cf ) strategy .
both the df and cf strategies appeared for abstract channels in the work of cover and el gamal @xcite . |
7,860 | Suppose that you have an abstract for a scientific paper: gamma - ray bursts ( grbs ) are proposed as candidate sources of ultra - high energy cosmic rays ( uhecrs ) .
we study the possibility that the pev neutrinos recently observed by icecube are produced by grb cosmic rays interacting with the interstellar gas in the host galaxies . by studying the relation between the x - ray absorption column density @xmath0 and the surface star - formation rate of grb host galaxies , we find that @xmath0 is a good indicator of the surface gas density of the host galaxies
. then we are able to calculate the neutrino production efficiency of crs for grbs with known @xmath0 .
we collect a sample of grbs that have both measurements of @xmath0 and accurate gamma - ray fluence , and attempt to calculate the accumulated neutrino flux based on the current knowledge about grbs and their host galaxies .
when the cr intensity produced by grbs is normalized with the observed uhecr flux above @xmath1 , the accumulated neutrino flux at pev energies is estimated to be about @xmath2 ( per flavor ) under the assumption that grb energy production rate follows the cosmic star - formation rate and the favorable assumption about the cr diffusion coefficient .
this flux is insufficient to account for the icecube observations , but the estimate suffers from some assumptions in the calculation and thus we can not rule out this scenario at present . .
And you have already written the first three sentences of the full article: gamma - ray bursts ( grbs ) have been proposed as a potential origin of ultra - high - energy cosmic rays ( uhecrs ) ( e.g. , waxman 1995 ; vietri 1995 ; milgrom and usov 1995 ) .
high - energy neutrinos are thought to be a useful messenger to probe cr acceleration in grbs , as they are predicted to be produced in the dissipative fireballs , where cosmic - ray protons interact with fireball gamma - ray photons through photopion process ( e.g. , waxman & bahcall 1997 ; guetta et al . 2004 ; dermer & atoyan 2006 ; murase et al . 2006 ;
wang & dai 2009 ) ..
Please generate the next two sentences of the article | however , search for high - energy neutrinos in coincident with grbs using icecube has failed to find any associated neutrinos so far ( abbasi et al .
2012 ; aartsen et al . 2015 ) . |
7,861 | Suppose that you have an abstract for a scientific paper: in this paper , we consider lovelock gravity in presence of two born - infeld types of nonlinear electrodynamics and study their thermodynamical behavior .
we extend the phase space by considering cosmological constant as a thermodynamical pressure . we obtain critical values of pressure , volume and temperature and investigate the effects of both the lovelock gravity and the nonlinear electrodynamics on these values .
we plot @xmath0 , @xmath1 and @xmath2 diagrams to study the phase transition of these thermodynamical systems .
we show that power of the nonlinearity and gravity have opposite effects .
we also show how considering cosmological constant , nonlinearity and lovelock parameters as thermodynamical variables will modify smarr formula and first law of thermodynamics .
in addition , we study the behavior of universal ratio of @xmath3 for different values of nonlinearity power of electrodynamics as well as the lovelock coefficients . .
And you have already written the first three sentences of the full article: in context of ads / cft correspondence , it was proposed that variation of cosmological constant corresponds to varying the number of colors in the boundary field theory of yang - mills with chemical potential interpretation @xcite . on the other hand , according to teitelboim and henneaux s mechanism , coupling four - dimensional gravity with antisymmetric gauge field without cosmological constant results into appearance of the cosmological constant as a constant of motion teit , and therefore , the cosmological constant will be a variable .
recently , the cosmological constant was considered as a state - dependant parameter in two dimensional dilaton gravity @xcite .
it was shown that treating the cosmological constant as a @xmath4 charge with non - minimal coupling leads to confining electrostatic potential ..
Please generate the next two sentences of the article | larranaga showed that considering the cosmological constant as thermodynamical variable can be extended to use the smarr formula for inner and outer horizons of btz black hole @xcite .
recently , there has been an increasing interest in thermodynamical behavior of black holes in asymptotically ads spacetime . |
7,862 | Suppose that you have an abstract for a scientific paper: this article is the second of a series of articles aiming at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications ( wind speed and direction , temperature , relative humidity ) and the optical turbulence ( @xmath0 and the derived astro - climatic parameters like seeing @xmath1 , isoplanatic angle @xmath2 , wavefront coherence time @xmath3 ... ) .
this study is done in the framework of the mose project , and focused above the two eso ground - bases sites of cerro paranal and cerro armazones . in this paper
we present the results related to the meso - nh model ability in reconstructing the surface layer atmospherical parameters ( wind speed intensity , wind direction and absolute temperature , [ 0 - 30 ] m a. g. l. ) .
the model reconstruction of all the atmospherical parameters in the surface layer is very satisfactory .
for the temperature , at all levels , the rmse ( root mean square error ) is inferior to 1@xmath4c . for the wind speed ,
it is @xmath52 m@xmath6s@xmath7 , and for the wind direction , it is in the range [ 38 - 46@xmath4 ] , at all levels , that corresponds to a rmse@xmath9 in a range [ 21 - 26% ] . if a filter is applied for the wind direction ( the winds inferior to 3 m@xmath6s@xmath7 are discarded from the computations ) , the wind direction rmse is in the range [ 30 - 41@xmath4 ] , i.e. a rmse@xmath9 in the range [ 17 - 23% ] .
the model operational forecast of the surface layer atmospherical parameters is suitable for different applications , among others : thermalization of the dome using the reconstructed temperature , hours in advance , of the beginning the night ; knowing in advance the main direction which the strong winds will come from during the night could allow the astronomer to anticipate the occurrence of a good / bad seeing night , and plan the observations accordingly ; preventing adaptive secondary mirrors shake generated by the wind speed .
[ firstpage ] turbulence - site....
And you have already written the first three sentences of the full article: this paper is the second part of a general study about the feasibility of the forecast of meteorological parameters and optical turbulence at eso sites ( cerro paranal and cerro armazones ) in the framework of the mose project ( modeling eso sites ) .
the mose project , and the first results obtained for the vertical stratification of different atmospheric parameters , are presented in a joint paper @xcite .
the reader can refer to this joint paper to have more details about mose ..
Please generate the next two sentences of the article | we only recall here that the mose project aims at proving the feasibility of the forecast of the most relevant classical atmospherical parameters for astronomical applications ( wind speed intensity and direction , temperature , relative humidity ) and the optical turbulence ot ( @xmath0 profiles ) with the integrated astro - climatic parameters derived from the @xmath0 i.e. the seeing ( @xmath10 ) , the isoplanatic angle ( @xmath2 ) , the wavefront coherence time ( @xmath3 ) above the two eso sites of cerro paranal ( site of the very large telescope - vlt ) and cerro armazones ( site selected for the european extremely large telescope - e - elt ) .
+ the final outcome of the project is to investigate the opportunity to implement an automatic system for the forecast of these parameters at the vlt observatory at cerro paranal and at the e - elt observatory at cerro armazones . |
7,863 | Suppose that you have an abstract for a scientific paper: we present the results of three - dimensional global magnetohydrodynamic ( mhd ) simulations of the parker - shearing instability in a differentially rotating torus initially threaded by toroidal magnetic fields .
an equilibrium model of magnetized torus is adopted as an initial condition .
when @xmath0 at the initial state , magnetic flux buoyantly escapes from the disk and creates loop - like structures similar to those in the solar corona . inside the torus , growth of non - axisymmetric magneto - rotational ( or balbus & hawley ) instability generates magnetic turbulence .
magnetic field lines are tangled in small scale but in large scale they show low azimuthal wave number spiral structure .
after several rotation period , the system oscillates around a state with @xmath1 .
we found that magnetic pressure dominated ( @xmath2 ) filaments are created in the torus . the volume filling factor of the region where @xmath3 is 2 - 10% .
magnetic energy release in such low-@xmath4 regions may lead to violent flaring activities in accretion disks and in galactic gas disks . .
And you have already written the first three sentences of the full article: magnetic fields in differentially rotating disks play essential roles in the angular momentum transport which enable the accretion and various activities such as x - ray flares and jet formation . motivated by the skylab observations of the solar corona , galeev , rosner , & vaiana ( 1979 ) proposed a model of magnetically structured corona in accretion disks consisting of x - ray emitting magnetic loops .
the magnetic loops can be created due to the buoyant rise of magnetic flux tubes ( or flux sheet ) from the interior of the accretion disk .
matsumoto et al . ( 1988 ) carried out two - dimensional magnetohydrodynamic ( mhd ) simulations of the parker instability ( parker 1966 ) in nonuniform gravitational fields which mimic those in accretion disks ..
Please generate the next two sentences of the article | they showed that when @xmath5 , a plane - parallel disk deforms itself into evacuated undulating magnetic loops and dense blobs accumulated in the valley of magnetic field lines .
the effects of rotation and shear flow , however , were not included in their simulations . shibata , tajima , & matsumoto ( 1990 ) carried out two - dimensional mhd simulations of the parker instability including the effects of shear flow and suggested that magnetic accretion disks fall into two types ; gas pressure dominated ( high-@xmath4 ) solar type disks , and magnetic pressure dominated ( low-@xmath4 ) cataclysmic disks . in high-@xmath4 ( @xmath6 ) disks , magnetic flux escapes from the disk more efficiently as @xmath4 decreases . several authors ( hawley , gammie & balbus 1995 ; matsumoto & tajima 1995 ; brandenburg et al . 1995 ; stone et al . |
7,864 | Suppose that you have an abstract for a scientific paper: aim of this work is to calculate explicitly the result of the experiment of superposition of a mirror in the michelson photon cavities interferometric device proposed by marshall , simon , penrose and bownmeester , as expected within a recently proposed model of non - unitary self - gravity inducing localization . as for other proposals of modifications of quantum mechanics in a non - unitary sense , aimed to account for both unitary evolution and irreversible collapse , like in the famous ghirardi - rimini - weber and pearle s models
, it turns out that , for the experimental parameters proposed , no effect is detectable at all .
it is pointed out that the enhancing properties of matter granularity does not substantially change this conclusion .
parameters have also been exploratively varied in a certain range beyond the proposed values .
it is shown that within ` sensible ' parameters , that are not yet attainable within current technology , the model exhibits a peculiar signature with respect to other collapse models as far as parameters space is explored .
besides , the calculation offers a way to see non - unitary gravity at work in a quasi - realistic setting . .
And you have already written the first three sentences of the full article: in the past few decades several proposals of modification of quantum mechanics ( qm ) have appeared in the literature , aimed at unifying its internal fundamental dichotomy between unitary deterministic quantum dynamics and non - linear irreversible state collapse following a measurement process @xcite . on the other hand big efforts
have been devoted towards an attempt to reconcile einstein gravity with quantum theory . in this context
, some approaches have focused on the possible role of gravity in state function collapse as a result of the incompatibility of general relativity and the unitary time evolution of qm @xcite ..
Please generate the next two sentences of the article | it has been shown , in fact , that the existence of linear superpositions of states with macroscopic mass - distribution differences would entail a breakdown of classical space - time making the traditional quantum dynamics somehow troubling @xcite .
as distinct from penrose proposal , some other detailed collapse models have been proposed , which are based on a spontaneous stochastic state vector reduction : the ghirardi - rimini - weber ( grw ) model @xcite , the quantum mechanics with universal position location model ( qmupl ) of wave function collapse @xcite and the continuous spontaneous localization ( csl ) model @xcite . |
7,865 | Suppose that you have an abstract for a scientific paper: several errors in refs .
@xcite are corrected related to the optical trapping potentials for a state - insensitive , compensated nanofiber trap for the @xmath0 transition of atomic cesium .
section i corrects our basic formalism in ref .
@xcite for calculating dipole - force potentials .
section ii corrects erroneous values for a partial lifetime and a transition wavelength in ref .
@xcite .
sections iii and iv present corrected figures for various trapping configurations considered in refs .
@xcite and @xcite , respectively . .
And you have already written the first three sentences of the full article: the light shifts calculated in ref .
@xcite are based upon eq .
( 2 ) in ref ..
Please generate the next two sentences of the article | the text states that the basis for eq .
( 2 ) is ` spherical ' ( i.e. , irreducible spherical tensors ) . |
7,866 | Suppose that you have an abstract for a scientific paper: we compute the equivariant k - homology of the groups psl@xmath0 of imaginary quadratic integers with trivial and non - trivial class - group .
this was done before only for cases of trivial class number .
+ we rely on reduction theory in the form of the @xmath1-cw - complex defined by flge .
we show that the difficulty arising from the non - proper action of @xmath1 on this complex can be overcome by considering a natural short exact sequence of @xmath2-algebras associated to the universal cover of the borel - serre compactification of the locally symmetric space associated to @xmath1 .
we use rather elementary @xmath2-algebraic techniques including a slightly modified atiyah - hirzebruch spectral sequence as well as several 6-term sequences . +
this computes the k - theory of the reduced and full group @xmath2-algebras of the bianchi groups . .
And you have already written the first three sentences of the full article: this paper is concerned with the bianchi groups , i.e. the class of groups defined by psl@xmath0 of the integers of an imaginary quadratic number field @xmath3 $ ] where @xmath4 is a product of different primes .
any such group is a group of orientation - preserving isometries of hyperbolic three space @xmath5 by means of the right - coset identification @xmath6 .
we aim at computing the left hand side of the baum - connes - conjecture for these groups ..
Please generate the next two sentences of the article | our main result is theorem [ statement ] that accomplishes the calculation in the example case @xmath7 .
+ there is vast literature on the bianchi groups @xcite and the conjecture @xcite . |
7,867 | Suppose that you have an abstract for a scientific paper: we have monitored the atoll - type neutron star low - mass x - ray binary 4u 163653 with the rossi x - ray timing explorer ( rxte ) for more than 1.5 years .
our campaign consisted of short ( @xmath02 ks ) pointings separated by two days , regularly monitoring the spectral and timing properties of the source . during the campaign we observed a clear long - term oscillation with a period of @xmath030 - 40 days , already seen in the light curves from the rxte all - sky monitor , which corresponded to regular transitions between the hard ( island ) and soft ( banana ) states .
we detected khz qpos in about a third of the observations , most of which were in the soft ( banana ) state .
the distribution of the frequencies of the peak identified as the lower khz qpo is found to be different from that previously observed in an independent data set .
this suggests that the khz qpos in the system shows no intrinsically preferred frequency .
[ firstpage ] x - rays : binaries accretion : accretion discs stars : neutron .
And you have already written the first three sentences of the full article: high - frequency quasi - periodic oscillations ( qpo ) in neutron - star x - ray binaries often appear in pairs , with frequencies ranging from a few hundred hz to more than 1 khz ( see van der klis 2006 for a review ) .
these so - called khz qpos , which were discovered with the rossi x - ray timing explorer ( rxte ) , provide a probe into the accretion flow very close to the compact objects and can possibly serve as a tool to observe effects of general relativity .
their frequencies are strongly correlated with other timing and spectral features ( see ford & van der klis 1998 ; psaltis , belloni & van der klis 1999 ; belloni , psaltis & van der klis 2002 ; van straaten et al ..
Please generate the next two sentences of the article | in particular , the frequencies of the lower ( @xmath1 ) and upper ( @xmath2 ) khz qpo are strongly correlated with each other ( see belloni , mndez & homan 2005 , hereafter bmh05 ) .
the correlation is roughly linear ( but see zhang et al . 2006 ) and similar for all sources ( belloni , mndez & homan 2007 ) . |
7,868 | Suppose that you have an abstract for a scientific paper: topological defects play an important role in physics of elastic media and liquid crystals .
their kinematics is determined by constraints of topological origin .
an example is the glide motion of dislocations which has been extensively studied by metallurgists . in a recent theoretical study dealing with quantum dualities associated with the quantum melting of solids
it was argued that these kinematic constraints play a central role in defining the quantum field theories of relevance to the description of quantum liquid crystalline states of the nematic type .
this forms the motivation to analyze more thoroughly the climb constraints underlying the glide motions . in the setting of continuum field theory
the climb constraint is equivalent to the condition that the density of constituent particles is vanishing and we derive a mathematical definition of this constraint which has a universal status .
this makes possible to study the kinematics of dislocations in arbitrary space - time dimensions and as an example we analyze the restricted climb associated with edge dislocations in 3 + 1d .
very generally , it can be shown that the climb constraint is equivalent to the condition that dislocations do not communicate with compressional stresses at long distances .
however , the formalism makes possible to address the full non - linear theory of relevance to short distance behaviors where violations of the constraint become possible . .
And you have already written the first three sentences of the full article: topological defects in crystals @xcite exhibit a rich variety of kinematic properties @xcite .
defects such as interstitials / vacancies , dislocations , and disclinations @xcite perturb the ideal perfectly periodic crystal . to date
, numerous works extensively studied the dynamics and coarsening of these defects , e.g. @xcite . in normal solids ,.
Please generate the next two sentences of the article | dislocations are present at low concentrations and their peculiar ` glide motions ' are an important factor in determining the plastic properties of the medium .
it has long been recognized that the energy - entropy balance of topological defects is responsible ( via deconfinement ) for melting transitions @xcite . in glasses , an extensive configurational entropy of these defects @xcite ( from which ensuing restrictive slow dynamics might follow @xcite ) |
7,869 | Suppose that you have an abstract for a scientific paper: we report the discoveries of two , two - image gravitationally lensed quasars selected from the sloan digital sky survey : sdss j0806 + 2006 at @xmath0 and sdss j1353 + 1138 at @xmath1 with image separations of @xmath2 and @xmath3 respectively .
spectroscopic and optical / near - infrared imaging follow - up observations show that the quasar images have identical redshifts and possess extended objects between the images that are likely to be lens galaxies at @xmath4 in sdss j0806 + 2006 and @xmath5 in sdss j1353 + 1138 .
the field of sdss j0806 + 2006 contains several nearby galaxies that may significantly perturb the system , and sdss j1353 + 1138 has an extra component near its einstein ring that is probably a foreground star .
simple mass models with reasonable parameters reproduce the quasar positions and fluxes of both systems . .
And you have already written the first three sentences of the full article: since the discovery of q0957 + 561 @xcite , about 80 gravitationally lensed quasars have been discovered @xcite .
lensed quasars are not only intriguing phenomena but also have become indispensable astronomical tools , including probes of the cosmological parameters and the structure of galaxies ( e.g. , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | in particular , the abundance of gravitational lenses in a well - defined source sample can be used to constrain dark energy ( e.g. , * ? ? ? * ; * ? ? ? * ; * ? ? ? * ) .
unfortunately , the largest existing survey , the cosmic lens all - sky survey ( class ; * ? ? ? |
7,870 | Suppose that you have an abstract for a scientific paper: we present an all - sky catalog of m dwarf stars with apparent infrared magnitude j@xmath010 .
the 8,889 stars are selected from the ongoing superblink survey of stars with proper motion @xmath140 mas yr@xmath2 , supplemented on the bright end with the tycho-2 catalog .
completeness tests which account for kinematic ( proper motion ) bias suggest that our catalog represents @xmath3 of the estimated @xmath4 m dwarfs with j@xmath010 expected to populate the entire sky .
our catalog is , however , significantly more complete for the northern sky ( @xmath590% ) than it is for the south ( @xmath560% ) .
stars are identified as cool , red m dwarfs from a combination of optical and infrared color cuts , and are distinguished from background m giants and highly - reddened stars using either existing parallax measurements or , if such measurements are lacking , on their location in an optical - to - infrared reduced proper motion diagram .
these bright m dwarfs are all prime targets for exoplanet surveys using the doppler radial velocity or transit methods ; the combination of low - mass and bright apparent magnitude should make possible the detection of earth - size planets on short - period orbits using currently available techniques .
parallax measurements , when available , and photometric distance estimates are provided for all stars , and these place most systems within 60 parsecs of the sun .
spectral type estimated from v - j color shows that most of the stars range from k7 to m4 , with only a few late m dwarfs , all within 20 pc .
proximity to the sun also makes these stars good targets for high - resolution exoplanet imaging searches , especially if younger objects can be identified on the basis of x - ray or uv excess . for that purpose ,
we include x - ray flux from rosat and fuv / nuv ultraviolet magnitudes from galex for all stars for which a counterpart can be identified in those catalogs .
additional photometric data include optical magnitudes from digitized sky survey plates , and....
And you have already written the first three sentences of the full article: m dwarfs are main sequence stars whose spectra display bands of tio and other molecules such as cah , vo , feh , and crh @xcite .
the high molecular opacities are the result of a cool atmosphere with effective temperatures in the range 2400k-3700k @xcite . observed orbital motion of astrometric binaries @xcite
show that m dwarfs have masses ranging from @xmath50.5 m@xmath6 all the way down to the hydrogen - burning limit ( @xmath50.075 m@xmath6 ) ..
Please generate the next two sentences of the article | m dwarfs have relatively small sizes , with radii roughly proportional to their masses .
recent measurements of eclipsing systems @xcite indicate a roughly linear relationship between masses and radii , with a 0.4 m@xmath6 ( 0.1 m@xmath6 ) m dwarf having a radius of 0.4 r@xmath6 ( 0.15 r@xmath6 ) . by number , |
7,871 | Suppose that you have an abstract for a scientific paper: in this talk , we present our recent next - to - leading order ( nlo ) nuclear parton distribution functions ( npdfs ) , which we call eps09 . as an extension to earlier nlo analyses , we supplement the deep inelastic scattering and drell - yan dilepton data by inclusive midrapidity pion measurements from rhic in order to reduce the otherwize large freedom in the nuclear gluon densities .
our hessian - type error analysis leading to a collection of npdf error sets , is the first of its kind among the npdf analyses . .
And you have already written the first three sentences of the full article: the global analyses of the free nucleon parton distribution functions ( pdfs ) are grounded on the asymptotic freedom of qcd , factorization and parton evolution .
these features allow to express the hard - process cross - sections formally as @xmath0 where @xmath1s are the scale - dependent pdfs , and @xmath2 denote the perturbatively computable partonic pieces .
the factorization theorem has turned out to work extremely well with increasingly many different types of data included in the latest free proton pdf analyses . for bound nucleons factorization.
Please generate the next two sentences of the article | is not as well - established , but it has anyway proven to do a very good job @xcite in describing the measured nuclear modifications @xmath3 in deep inelastic scattering ( dis ) and drell - yan ( dy ) dilepton production involving nuclear targets .
this talk summarizes our new nlo analysis @xcite . |
7,872 | Suppose that you have an abstract for a scientific paper: the higgs amplitude mode of the order parameter of an ultracold confined fermi gas in the bcs regime after a quench of the coupling constant is analyzed theoretically .
characteristic features are a damped oscillation which at a certain transition time changes into a rather irregular dynamics .
we compare the numerical solution of the full set of nonlinear equations of motion for the normal and anomalous bogoliubov quasiparticle excitations with a linearized approximation . in doing so the transition time as well as the difference between resonant systems , i.e. , systems where the fermi energy is close to a subband minimum , and off - resonant systems
can be well understood and traced back to the system and geometry parameters . .
And you have already written the first three sentences of the full article: ultracold fermi gases have been subject of many experimental and theoretical studies during recent years ( see e.g. @xcite ) .
they provide a unique system to study key concepts of condensed matter theory .
this is because in these systems many parameters such as the particle density , the fermi energy , the confinement potential , or the interaction strength between the fermions , which in a solid state system are typically fixed quantities , can be externally controlled in a wide range @xcite . in particular , magnetic - field feshbach resonances provide the means for controlling the interaction strength between fermions by varying an external magnetic field ..
Please generate the next two sentences of the article | the tunability of the s - wave scattering length , which is the dominant interaction channel , makes ultracold fermi gases ideal for exploring different regimes of interacting many - body systems in a single system .
this includes the limiting regimes of weakly attracting fermions , which condense into cooper pairs forming a bardeen - cooper - schrieffer ( bcs ) phase below a certain temperature @xmath0 , and repulsive dimers formed by two fermions , which can undergo a bose - einstein condensation ( bec ) . |
7,873 | Suppose that you have an abstract for a scientific paper: poloidal and toroidal velocities of fully - ionised carbon are measured by means of charge exchange recombination spectroscopy ( cxrs ) in the tj - ii stellarator .
we present a detailed treatment of the 3d geometry and show that flow measurements , performed at different locations of the same flux surface , are compatible with flow incompressibility for the low density plasmas under study ( line averaged electron densities @xmath0 m@xmath1 ) .
furthermore , comparison with neoclassical calculations shows quantitative agreement with the measured radial electric field and ion bootstrap parallel flow in the absence of an external momentum input . .
And you have already written the first three sentences of the full article: plasma rotation has become one of the key ingredients of fusion plasma performance , after the discovery of a reduction of turbulence and transport @xcite through a sheared @xmath2 rotation .
with regard to stability , large toroidal rotations can stabilize resistive wall modes and neoclassical tearing modes .
for these reasons , the physics of toroidal momentum transport , and the so - called intrinsic rotation , have become a very active area of research , mainly for their importance in the operation of a reactor plasma , for which the external torque will be negligible @xcite ..
Please generate the next two sentences of the article | thus , reliable rotation measurements are requiered . in this sense , the charge exchange recombination spectroscopy ( cxrs ) technique @xcite has developed into a basic tool for diagnosing plasma rotation over the last three decades , and will be a key diagnostic for iter @xcite .
one of the basic results of the kinetic theory of strongly magnetized plasmas with small ( compared to thermal ) @xmath2 velocity , is that first order ion and electron flows are parallel to flux surfaces and incompressible @xcite , _ i.e. _ , their velocity fields satisfy @xmath3 . |
7,874 | Suppose that you have an abstract for a scientific paper: in this paper we study the rank of planar rigidity matrix of 4-valent graphs , both in case of generic realizations and configurations in general position , under various connectivity assumptions on the graphs . for each case
considered , we prove a lower bound and provide an example which shows the order of the bound we proved is sharp .
this work is closed related to work in @xcite and answers some questions raised there . .
And you have already written the first three sentences of the full article: let @xmath0 be a connected 4-valent graph and @xmath1 a planar realization(the words realization and configuration will be used interchangeably ) . the graph @xmath2 is always assumed to be finite and simple .
the rigidity matrix , which we denote by @xmath3 , is a matrix of size @xmath4 .
the rank of @xmath3 , which we denote by @xmath5 , can be taken as the definition of the rank of the _ infinitesimal rigidity matroid _ of the framework @xmath6 ..
Please generate the next two sentences of the article | when @xmath7 is a _ generic realization _
, one can show @xmath5 is independent of @xmath7 as long as it is generic , this can be taken as the definition of the rank of the _ generic rigidity matroid _ of @xmath2 and we will write @xmath8 for it . for more details on the definitions and terminologies in rigidity theory , we refer the readers to @xcite |
7,875 | Suppose that you have an abstract for a scientific paper: transformation optics is used to design a gateway that can block electromagnetic waves but allows the passage of other entities .
our conceptual device has the advantage that it can be realized with simple materials and structural parameters and can have a reasonably wide bandwidth . in particular , we show that our system can be implemented by using a magnetic photonic crystal structure that employs a square ray of ferrite rods , and as the field response of ferrites can be tuned by external magnetic fields , we end up with an electromagnetic gateway that can be open or shut using external fields .
the functionality is also robust against the positional disorder of the rods that made up the photonic crystal . .
And you have already written the first three sentences of the full article: transformation optics @xcite has paved the way for the development of optical devices that can realize functionalities that were thought to be possible only in science fictions @xcite-@xcite .
one such conceptual device that has attracted great public interest is a gateway that can block electromagnetic waves but that allows the passage of other entities .
this device can be viewed as an implementation of a `` hidden portal '' mentioned in fictions @xcite ..
Please generate the next two sentences of the article | however , the feasibility of such devices is limited by the very complex material parameters and the narrow bandwidth . here , we show that gateway - type devices can actually be realized with simple parameters and they can have wider band widths such that the concept is closer to reality @xcite-@xcite than previously thought .
the structure can be implemented by using the magnetic photonic crystal structures that are field tunable , resulting in an invisible electromagnetic gateway that can be open or shut using magnetic fields . |
7,876 | Suppose that you have an abstract for a scientific paper: the sydney aao multi - object integral field spectrograph ( sami ) galaxy survey is an ongoing project to obtain integral field spectroscopic observations of @xmath03400 galaxies by mid-2016 . including the pilot survey , a total of @xmath01000 galaxies have been observed to date , making the sami galaxy survey the largest of its kind in existence .
this unique dataset allows a wide range of investigations into different aspects of galaxy evolution
. the first public data from the sami galaxy survey , consisting of 107 galaxies drawn from the full sample , has now been released . by giving early access to sami data for the entire research community
, we aim to stimulate research across a broad range of topics in galaxy evolution .
as the sample continues to grow , the survey will open up a new and unique parameter space for galaxy evolution studies . .
And you have already written the first three sentences of the full article: large - scale spectroscopic galaxies surveys , such as the sloan digital sky survey ( sdss ; @xcite ) and galaxy and mass assembly ( gama ; @xcite ) survey , are well established and powerful tools for investigations of galaxy evolution
. however , they are limited by only observing a single aperture in the centre of each galaxy , so are inherently unable to investigate the spatially distributed properties of galaxies .
integral field spectrographs ( ifss ) provide the information missed by traditional fibre - based surveys ..
Please generate the next two sentences of the article | the spatially resolved spectroscopic data produced by an ifs can be used to measure diverse quantities such as rotation curves , spatial distributions of star formation , and radial variation in stellar populations . until recently , technical limitations made ifs observations difficult and time - consuming , limiting sample sizes to a few hundred at most , e.g. 260 in atlas-3d @xcite and @xmath0600 in califa @xcite
. a massive step forward is now being taken by instruments that can make ifs observations of multiple objects at once . |
7,877 | Suppose that you have an abstract for a scientific paper: we study the rotation rates and electric dipole emission of hydrogenated icosahedral fullerenes ( single and multishell ) in various phases of the interstellar medium . using the formalism of draine and lazarian for the rotational dynamics of these molecules in various astrophysical environments , we find effective rotation rates in the range 165 ghz with a trend toward lower rotational frequency as the radius of the molecule increases .
owing to the moderately polar nature of the c h bond , hydrogenated fullerenes ( fulleranes ) are expected to have a net dipole moment and produce electric dipole radiation . adopting the same size distribution proposed for fullerenes in the study of the uv extinction bump ( 2175 ) we predict the dipole electric emission of mixtures of fulleranes for various levels of hydrogenation .
we find that these molecules could be the carriers of the anomalous microwave emission recently detected by watson et al . in the perseus molecular complex . .
And you have already written the first three sentences of the full article: recent experiments dedicated to the study of the anisotropy of the cosmic microwave background have found evidence for galactic microwave emission in the range 1090 ghz correlated at high galactic latitudes with thermal emission ( dirbe 100 @xmath0 m map ) from interstellar dust ( kogut et al . 1996 ; leitch et al . 1997 ; de oliveira - costa et al . 1999 , 2002 , 2004 ) .
an explanation for this anomalous dust - correlated microwave emission based on electric dipole emission from fast rotating carbon - based molecules has been proposed by draine & lazarian 1998a , b ) .
these models appear to reproduce the major features of the so - called anomalous microwave emission ( finkbeiner et al ..
Please generate the next two sentences of the article | 2004 ) but do not identify the actual carrier of the emission . iglesias - groth ( 2004 ) has recently shown that photoabsorption by fullerenes and buckyonions ( multishell fullerenes ) in the interstellar medium ( ism ) can account for the uv bump ( 217.5 nm ) of the interstellar extinction curve and possibly for some of the diffuse interstellar bands .
it is suggested that fullerenes and buckyonions are broadly distributed in the galaxy and contain a large fraction of interstellar carbon . |
7,878 | Suppose that you have an abstract for a scientific paper: in the bayesian approach , the a priori knowledge about the input of a mathematical model is described via a probability measure .
the joint distribution of the unknown input and the data is then conditioned , using bayes formula , giving rise to the posterior distribution on the unknown input . in this
setting we prove posterior consistency for nonlinear inverse problems : a sequence of data is considered , with diminishing fluctuations around a single truth and it is then of interest to show that the resulting sequence of posterior measures arising from this sequence of data concentrates around the truth used to generate the data .
posterior consistency justifies the use of the bayesian approach very much in the same way as error bounds and convergence results for regularisation techniques do . as a guiding example
, we consider the inverse problem of reconstructing the diffusion coefficient from noisy observations of the solution to an elliptic pde in divergence form .
this problem is approached by splitting the forward operator into the underlying continuum model and a simpler observation operator based on the output of the model . in general ,
these splittings allow us to conclude posterior consistency provided a deterministic stability result for the underlying inverse problem and a posterior consistency result for the bayesian regression problem with the push - forward prior .
moreover , we prove posterior consistency for the bayesian regression problem based on the regularity , the tail behaviour and the small ball probabilities of the prior . .
And you have already written the first three sentences of the full article: many mathematical models used in science and technology contain parameters for which a direct observation is very difficult .
a good example is subsurface geophysics .
the aim in subsurface geophysics is the reconstruction of subsurface properties such as density and permeability given measurements on the surface.using the laws of physics , these properties can be used as parameters of a forward model mapping them to the measurements which we subsequently call data ..
Please generate the next two sentences of the article | inverting such a relationship is non - trivial and lies in the focus of the area of inverse problems .
classically , these parameters are estimated by minimisation of a regularised least squares functional which is based on the data output mismatch ( tikhonov ) . |
7,879 | Suppose that you have an abstract for a scientific paper: in aloha - type packetized network , the transmission times of packets follow a stochastic process . in this paper , we advocate a deterministic approach for channel multiple - access .
each user is statically assigned a periodic protocol signal , which takes value either zero or one , and transmit packets whenever the value of the protocol signal is equal to one . on top of this multiple - access protocol , efficient channel coding and network coding schemes are devised .
we illustrate the idea by constructing a transmission scheme for the tandem collision network , for both slot - synchronous and slot - asynchronous systems .
this cross - layer approach is able to achieve the capacity region when the network is bi - directional .
collision channel , protocol sequence , tandem network , bi - directional network , network coding . .
And you have already written the first three sentences of the full article: in their study of multiple - access collision channel without feedback , massey and mathys show that the capacity region can be achieved by deterministic channel access method @xcite .
it contrasts with the more traditional multiple - access scheme like pure aloha or slotted aloha@xcite , where transmission times of packets form a random process . in this paper , we extend the transmission scheme by massey and mathys to tandem network , in which nodes are located on a straight line .
nodes that are more than two hops away do not interfere with each other ..
Please generate the next two sentences of the article | if a node receives two packets that overlap in time , either partially or completely , both packets are assumed erased and unrecoverable .
this model is applicable to wireless sensor network along a highway or river for instance . |
7,880 | Suppose that you have an abstract for a scientific paper: we present an extensive numerical study of spin quadrupolar correlations in single and coupled bilinear - biquadratic spin one chains , using several methods such as exact diagonalization , density matrix renormalization group and strong coupling series expansions . for the single chain we clarify the dominant correlation function in the enigmatic gapless period - three phase for @xmath0 , which is of spin quadrupolar nature with a period three spatial structure .
then we revisit the open problem of the possible existence of a ferroquadrupolar phase between the dimerized and the ferromagnetic phases .
although an extended critical region is in principle compatible with the numerical results , a scenario with a huge crossover scale is more plausible . finally we study the fate of the dimerized phase upon coupling two chains in a ladder geometry .
the dimerized phase rapidly vanishes and an extended gapped phase takes over .
this gapped phase presumably has dominant short - ranged ferroquadrupolar correlations for @xmath1 and suprisingly seems to be adiabatically connected to the plaquette single solid phase of the heisenberg @xmath2 ladder and therefore also with the haldane phase of isolated chains . .
And you have already written the first three sentences of the full article: the recent experimental demonstration @xcite of the transition from a superfluid state to a mott insulating state of atoms in an optical lattice has opened the way to novel realizations of effective quantum lattice models with widely tunable control parameters .
quantum magnetic systems can be realized by spinor atoms in an optical lattice , e.g. @xmath3na with a total @xmath2 moment .
confining @xmath2 atoms to an optical lattice there are two scattering channels for identical atoms with total spin @xmath4 which can be mapped to an effective bilinear and biquadratic spin interaction @xcite : h=_i , j , [ eqn : biquadhamiltonian ] where we adopt the standard parametrization @xmath5 and @xmath6 . in one dimension , the bilinear - biquadratic spin - one model has a rich phase diagram ( see fig . [.
Please generate the next two sentences of the article | fig : phasediagram ] ) with some well established phases : the haldane gap phase @xcite , a dimerized phase @xcite , a ferromagnetic phase and some less well understood phases : a critical phase with period three correlations @xcite , which we will characterize as having dominant spin nematic correlations , and possibly a gapped spin nematic phase between the dimerized and ferromagnetic phase @xcite , which however remains controversial . on the square and the simple cubic lattice , the bilinear - biquadratic spin - one model is well understood for the case @xmath7 .
it exhibits a ferroquadrupolar spin nematic phase for @xmath8 @xcite . |
7,881 | Suppose that you have an abstract for a scientific paper: long s equation describes two dimensional stratified atmospheric flow over terrain which is represented by the geometry of the domain .
the solutions of this equation over simple topography were investigated analytically and numerically by many authors . in this paper
we derive a new terrain following formulation of this equation which incorporates the terrain as part of the differential equation rather than the geometry of the domain .
this leads to new analytic insights about the solutions of this equation and enable us to compute steady state gravity wave patterns over complex topography .
pacs 92.60.gn , 92.60.dj , 02.30.ik .
And you have already written the first three sentences of the full article: long s equation [ 1,2,3,4 ] models the flow of stratified incompressible fluid in two dimensions over terrain .
when the base state of the flow ( that is the unperturbed flow field far upstream ) is without shear the numerical solutions ( in the form of steady lee waves ) of this equation over simple topography ( i.e. one hill ) were studied by many authors [ 5 - 13 ] .
the most common approximation in these studies was to set brunt - visl frequency to a constant or a step function over the computational domain ..
Please generate the next two sentences of the article | moreover the values of two physical parameters which appear in this equation were set to zero .
( these parameters control the stratification and dispersive effects of the atmosphere - see @xmath0 . ) in this ( singular ) limit the nonlinear terms and one of the leading second order derivatives in the equation drop out and the equation reduces to that of a linear harmonic oscillator over two dimensional domain . |
7,882 | Suppose that you have an abstract for a scientific paper: due to stellar rotation , the observed radial velocity of a star varies during the transit of a planet across its surface , a phenomenon known as the rossiter - mclaughlin ( rm ) effect .
the amplitude of the rm effect is related to the radius of the planet which , because of differential absorption in the planetary atmosphere , depends on wavelength .
therefore , the wavelength - dependent rm effect can be used to probe the planetary atmosphere .
we measure for the first time the rm effect of the earth transiting the sun using a lunar eclipse observed with the eso harps spectrograph .
we analyze the observed rm effect at different wavelengths to obtain the transmission spectrum of the earth s atmosphere after the correction of the solar limb - darkening and the convective blueshift . the ozone chappuis band absorption as well as
the rayleigh scattering features are clearly detectable with this technique .
our observation demonstrates that the rm effect can be an effective technique for exoplanet atmosphere characterization .
its particular asset is that photometric reference stars are not required , circumventing the principal challenge for transmission spectroscopy studies of exoplanet atmospheres using large ground - based telescopes . .
And you have already written the first three sentences of the full article: among the nearly 2000 exoplanets discovered so far , more than half are transiting systems . due to the rotation of the host star , the observed stellar radial velocity ( rv )
is expected to change as the planet transits different parts of the rotating stellar surface .
this is called the rossiter - mclaughlin ( rm ) effect and was initially measured for eclipsing binary stars @xcite ..
Please generate the next two sentences of the article | after the first observation of the exoplanetary rm effect by @xcite , there are now more than 80 exoplanet systems with this effect observed , e. g. @xcite .
this effect is normally used to measure the projected angle between the stellar spin and the planetary orbit . |
7,883 | Suppose that you have an abstract for a scientific paper: we report the possible detection ( 99.3% of statistical significance ) of redshifted fe iron line emission in the x - ray afterglow of gamma - ray burst grb970508 observed by bepposax .
its energy is consistent with the redshift of the putative host galaxy determined from optical spectroscopy .
the line disappeared @xmath0 day after the burst .
we have also analyzed the spectral variability during the outburst event that characterizes the x - ray afterglow of this grb .
the spectrum gets harder during the flare , turning to steep when the flux decreases .
the variability , intensity and width of the line indicate that the emitting region should have a mass @xmath1 ( assuming the iron abundance similar to its solar value ) , a size of @xmath2 , is distributed anisotropically , and is moving with sub - relativistic speed .
in contrast to the fairly clean environment expected in the merging of two neutron stars , the observed line properties would imply that the site of the burst is embedded in a large mass of material , consistent with pre - explosion ejecta of a very massive star .
this material could be related with the outburst observed in the afterglow 1 day after the grb and with the spectral variations measured during this phase .
1s^-1 2cm^-2 2r^2 _ .
And you have already written the first three sentences of the full article: distance - scale determination of gamma - ray bursts ( grb ) has been one of the most important achievements of astrophysics in recent years .
accurate and fast localization of the prompt and afterglow emission bursts ( i.e.@xcite ) by the italian / dutch x ray satellite bepposax ( @xcite ) led to the identification of optical counterparts ( @xcite ) and ultimately to spectral measurements of a redshift ( @xcite ) . while the extragalactic origin of grb has gathered solid evidence in its support , the source of the large energy implied by their distance is still speculative .
direct information on the nature of the central engine of grb can be derived by studying the nearby environment ; for example using line spectroscopy ..
Please generate the next two sentences of the article | the star forming region and massive pre - explosion winds associated with the hypernova scenario ( @xcite ) imply a mass rich environment down to short ( @xmath3 ) distance scales .
in contrast , ns - ns merging should happen in a fairly clean environment , because such objects are expected to form with significant speeds which can lead them at least a few parsecs away from the regions of star formation in which they formed . |
7,884 | Suppose that you have an abstract for a scientific paper: i review our qualitative understanding of the increase in the value of the b meson decay constant ( @xmath0 ) , when dynamical fermions are included in lattice qcd calculations . .
And you have already written the first three sentences of the full article: the over determination of the ckm matrix , using the new data from the b factories at slac and kek , is a sensitive test of the standard model @xcite .
the determination of the ckm matrix elements from experiment depends critically on hadronic parameters , such as @xmath0 , @xmath1 , @xmath2 and @xmath3 , most of which are inaccessible to experiment , but can be calculated from lattice qcd . in a recent survey of the latest lattice
qcd results for the @xmath0 ( the decay constant of the b meson ) bernard @xcite quotes : @xmath4 mev from quenched qcd and @xmath5 mev for the value of the b decay constant in full qcd ..
Please generate the next two sentences of the article | although all lattice qcd calculations @xcite have seen an increase in @xmath0 between quenched and unquenched qcd , the effect in the world `` average '' is only at the one @xmath6 level .
the increase in @xmath0 between quenched and full qcd is more significant for an individual collaboration s results , for example cp - pacs , obtain @xcite @xmath7 . |
7,885 | Suppose that you have an abstract for a scientific paper: the results of five years of development of the inner tracking system of the hera - b experiment and first experience from the data taking period of the year 2000 are reported .
the system contains 184 chambers , covering a sensitive area of about ( 20 @xmath0 20 ) @xmath1 each .
the detector is based on microstrip gas counters ( msgcs ) with diamond like coated ( dlc ) glass wafers and gas electron multipliers ( gems ) .
the main problems in the development phase were gas discharges in intense hadron beams and aging in a high radiation dose environment .
the observation of gas discharges which damage the electrode structure of the msgc led to the addition of the gem as a first amplification step .
spurious sparking at the gem can not be avoided completely .
it does not affect the gem itself but can produce secondary damage of the msgc if the electric field between the gem and the msgc is above a threshold depending on operation conditions .
we observed that aging does not only depend on the dose but also on the spot size of the irradiated area .
ar - dme mixtures had to be abandoned whereas a mixture of 70% ar and 30% co@xmath2 showed no serious aging effects up to about 40 mc / cm deposited charge on the anodes .
x - ray measurements indicate that the dlc of the msgc is deteriorated by the gas amplification process . as a consequence
, long term gain variations are expected .
the inner tracker has successfully participated in the data taking at hera - b during summer 2000 .
msgc , msgc - gem , gas aging , discharges , hera - b 29.40.g , 29.40.c , 07.85.f , 81.40.c , 52.80 .
And you have already written the first three sentences of the full article: the experiment @xcite was designed with the goal to measure cp violation in the b - system .
it started operation at desy , hamburg in spring 2000 .
neutral b - mesons are produced by interactions of 920 gev protons on a stationary nuclear target followed by a magnetic spectrometer . since the b cross section is very low , the experiment was planed for an interaction rate of 40 mhz to obtain an acceptable b production rate ..
Please generate the next two sentences of the article | the detectors therefore were designed to withstand the corresponding high particle rates and high radiation levels . to cope with the high particle flux which drops roughly
as one over the distance from the beam axis squared , the main tracking system has been subdivided into two parts with different rate capabilities : the inner tracker ( itr ) near the beam pipe and at larger distance the outer tracker ( otr ) consisting of drift chambers composed of honeycomb structures . |
7,886 | Suppose that you have an abstract for a scientific paper: we present the results of molecular dynamics computer simulations of a binary lennard - jones liquid confined between two parallel rough walls .
these walls are realized by frozen amorphous configurations of the same liquid and therefore the structural properties of the confined fluid are identical to the ones of the bulk system .
hence this setup allows us to study how the relaxation dynamics is affected by the pure effect of confinement , i.e. if structural changes are completely avoided .
we find that the local relaxation dynamics is a strong function of @xmath0 , the distance of the particles from the wall , and that close to the surface the typical relaxation times are orders of magnitude larger than the ones in the bulk . because of the cooperative nature of the particle dynamics
, the slow dynamics also affects the dynamics of the particles for large values of @xmath0 . using various empirical laws , we are able to parameterize accurately the @xmath1dependence of the generalized incoherent intermediate scattering function @xmath2 and also the spatial dependence of structural relaxation times .
these laws allow us to determine various dynamical length scales and we find that their temperature dependence is compatible with an arrhenius law .
furthermore , we find that at low temperatures time and space dependent correlation function fulfill a generalized factorization property similar to the one predicted by mode - coupling theory for bulk systems . for thin films and/or at sufficiently low temperatures
, we find that the relaxation dynamics is influenced by the two walls in a strongly non - linear way in that the slowing down is much stronger than the one expected from the presence of only one confining wall .
finally we study the average dynamics of all liquid particles and find that the data can be described very well by a superposition of two relaxation processes that have clearly separated time scales .
since this is in contrast with the result of our analysis of the local....
And you have already written the first three sentences of the full article: the origin for the dramatic slowing down of the relaxation dynamics of a liquid close to the glass transition is still a matter of debate @xcite .
different theoretical approaches to describe the dynamic transition from the liquid to the glassy state have been presented so far .
some concentrate on thermodynamic aspects and propose a first or second order phase transition ( e.g. free volume theory @xcite or entropy models @xcite ) , while others , such as mode - coupling theory @xcite , focus on the microscopic dynamics that shows non - linear feedback effects which are responsible for the slow dynamics ..
Please generate the next two sentences of the article | many of these theories are using in some form the concept of cooperative motion within a liquid . as already mentioned by kauzmann @xcite it is reasonable to assume that in a liquid neighboring particles can not move independently of each other , in particular at low temperatures .
instead one must expect that the motion of two particles that are separated by a distance that is short is cooperative , i.e. there exist cooperatively rearranging regions ( crr s ) within the liquid . |
7,887 | Suppose that you have an abstract for a scientific paper: fragmentation functions for charged particles in @xmath0 events have been measured for bottom ( b ) , charm ( c ) and light ( uds ) quarks as well as for all flavours together .
the results are based on data recorded between 1990 and 1995 using the opal detector at lep .
event samples with different flavour compositions were formed using reconstructed mesons and secondary vertices .
the @xmath1 distributions and the position of their maxima are also presented separately for uds , c and b quark events .
the fragmentation function for b quarks is significantly softer than for uds quarks .
european laboratory for particle physics cern - ep/98 - 089 + 29 may 1998 * measurements of flavour dependent fragmentation functions in @xmath2 events * the opal collaboration + submitted to european physics journal c + the opal collaboration k.ackerstaff@xmath3 , g.alexander@xmath4 , j.allison@xmath5 , n.altekamp@xmath6 , k.j.anderson@xmath7 , s.anderson@xmath8 , s.arcelli@xmath9 , s.asai@xmath10 , s.f.ashby@xmath11 , d.axen@xmath12 , g.azuelos@xmath13 , a.h.ball@xmath14 , e.barberio@xmath3 , r.j.barlow@xmath5 , r.bartoldus@xmath15 , j.r.batley@xmath6 , s.baumann@xmath15 , j.bechtluft@xmath16 , t.behnke@xmath3 , k.w.bell@xmath17 , g.bella@xmath4 , s.bentvelsen@xmath3 , s.bethke@xmath16 , s.betts@xmath18 , o.biebel@xmath16 , a.biguzzi@xmath6 , s.d.bird@xmath5 , v.blobel@xmath19 , i.j.bloodworth@xmath11 , m.bobinski@xmath20 , p.bock@xmath21 , j.bhme@xmath16 , m.boutemeur@xmath22 , s.braibant@xmath3 , p.bright-thomas@xmath11 , r.m.brown@xmath17 , h.j.burckhart@xmath3 , c.burgard@xmath3 , r.brgin@xmath20 , p.capiluppi@xmath9 , r.k.carnegie@xmath23 , a.a.carter@xmath24 , j.r.carter@xmath6 , c.y.chang@xmath14 , d.g.charlton@xmath25 , d.chrisman@xmath26 , c.ciocca@xmath9 , p.e.l.clarke@xmath18 , e.clay@xmath18 , i.cohen@xmath4 , j.e.conboy@xmath18 , o.c.cooke@xmath3 , c.couyoumtzelis@xmath24 , r.l.coxe@xmath7 , m.cuffiani@xmath9 , s.dado@xmath27 , g.m.dallavalle@xmath9 , r.davis@xmath28 , s.de....
And you have already written the first three sentences of the full article: experimental measurements of the inclusive momentum distribution of charged particles in collisions provide important insight into the process of how quarks turn into hadrons .
this distribution is commonly normalised to the total hadronic cross section @xmath48 and presented as a function of the scaled momenta @xmath49 of the charged hadrons , where is the centre - of - mass energy . in this form ,
the spectrum is usually referred to as the fragmentation function and can be obtained experimentally from the total number of hadronic final states , @xmath50 , and the number of charged particles in each bin , @xmath51 : @xmath52 the charged particle momentum spectrum can also be studied as the distribution of @xmath1 ..
Please generate the next two sentences of the article | the distribution emphasises the low momentum component and the distribution the high momentum component of the momentum spectrum . in the nave
quark parton model , the scaled momentum distribution is expected to be independent from the centre - of - mass energy . a violation of this scaling is expected due to gluon radiation in the final state . experimentally , scaling violation in fragmentation functions had indeed been observed by combining measurements at different centre - of - mass energies and could be used to determine @xcite . |
7,888 | Suppose that you have an abstract for a scientific paper: there is strong evidence indicating that the particular form used to recast the einstein equation as a 3 + 1 set of evolution equations has a fundamental impact on the stability properties of numerical evolutions involving black holes and/or neutron stars .
presently , the longest lived evolutions have been obtained using a parametrized hyperbolic system developed by kidder , scheel and teukolsky or a conformal - traceless system introduced by baumgarte , shapiro , shibata and nakamura .
we present a new conformal - traceless system .
while this new system has some elements in common with the baumgarte - shapiro - shibata - nakamura system , it differs in both the type of conformal transformations and how the non - linear terms involving the extrinsic curvature are handled .
we show results from 3d numerical evolutions of a single , non - rotating black hole in which we demonstrate that this new system yields a significant improvement in the life - time of the simulations . .
And you have already written the first three sentences of the full article: so far , every 3d effort to perform 3 + 1 numerical simulations of space - times containing black - hole singularities , or compact objects such as neutron stars , has encountered the frustration of producing short - lived evolutions .
the impediment is due to the presence of sever instabilities .
there is a common agreement among researchers that the origin of these instabilities is not purely numerical ..
Please generate the next two sentences of the article | inconsistent boundary conditions far away from the holes or neutron stars , unsuitable choices of gauge or coordinate conditions , inappropriate algorithms to excise the black hole singularity , etc .
are all contributing factors . since approximately the mid 90 s |
7,889 | Suppose that you have an abstract for a scientific paper: in this work we characterize those shift spaces which can support a 1-block quasi - group operation and show the analogous of kitchens result : any such shift is conjugated to a product of a full shift with a finite shift .
moreover , we prove that every expansive automorphism on a compact zero - dimensional quasi - group that verifies the medial property , commutativity and has period 2 , is isomorphic to the shift map on a product of a finite quasi - group with a full shift .
marcelo sobottka ' '' '' _ this is a pre - copy - editing , author - produced pdf of an article accepted for publication in discrete and continuous dynamical systems - series a ( dcds - a ) , following peer review .
the definitive publisher - authenticated version marcelo sobottka , topological quasi - group shifts . disc . and cont .
dynamic . systems ( 2007 ) , 17 , 1 , 77 - 93 , is available online at : http://www.aimsciences.org / journals / displayarticles.jsp?paperid=2044 . _ ' '' '' .
And you have already written the first three sentences of the full article: one of the main questions concerning symbolic dynamics and algebraic structures was asked by r. bowen : characterize group shifts , that is shifts supporting a group structure so that the shift map is an automorphism .
this question was answered by b. kitchens @xcite , who showed that any group shift is conjugated to the product of a full shift with a finite set .
a more general case was studied by n.t ..
Please generate the next two sentences of the article | sindhushayana , b. marcus and m. trott @xcite , who proved the analogous result for a homogeneous shift , that is a shift space @xmath0 on the alphabet @xmath1 for which there exist a group @xmath2 of permutations of @xmath1 and a group shift @xmath3 , such that @xmath0 is invariant under the action of any element of @xmath4 .
this work concentrates on quasigroups , often called cancellation semi - groups , thus with left and right cancellable operations . in [ ii2 ] we present sufficient and necessary conditions to a compact zero - dimensional quasi - group @xmath5 , where is defined an expansive automorphism @xmath6 , to be conjugated and isomorphic to a markov shift with a 1-block operation . |
7,890 | Suppose that you have an abstract for a scientific paper: in this paper , we consider a time - optimal control problem with uncertainties .
dynamics of controlled object is expressed by crisp linear system of differential equations with fuzzy initial and final states .
we introduce a notion of fuzzy optimal time and reduce its calculation to two crisp optimal control problems .
we examine the proposed approach on an example .
* keywords : * optimal - time control , fuzzy set , maximum principle , mathematical pendulum . .
And you have already written the first three sentences of the full article: many researchers investigate optimal control problems with uncertainties . in @xcite ,
gabasov et al .
consider optimal preposterous observation and optimal control problems for dynamic systems under uncertainty with use of a priori and current information about the controlled object behavior and uncertainty . in @xcite , gabasov et al ..
Please generate the next two sentences of the article | investigate for an optimal control problem under uncertainty the positional solutions , which are based on the results of inexact measurements of input and output signals of controlled object . in @xcite ,
gabasov et al . |
7,891 | Suppose that you have an abstract for a scientific paper: we develop spectral theory for the generator of the @xmath0-boson ( stochastic ) particle system .
our central result is a plancherel type isomorphism theorem for this system .
this theorem has various implications .
it proves the completeness of the bethe ansatz for the @xmath0-boson generator and consequently enables us to solve the kolmogorov forward and backward equations for general initial data . owing to a markov duality with @xmath0-tasep ,
this leads to moment formulas which characterize the fixed time distribution of @xmath0-tasep started from general initial conditions .
the theorem also implies the biorthogonality of the left and right eigenfunctions .
we consider limits of our @xmath0-boson results to a discrete delta bose gas considered previously by van diejen , as well as to another discrete delta bose gas that describes the evolution of moments of the semi - discrete stochastic heat equation ( or equivalently , the oconnell - yor semi - discrete directed polymer partition function ) .
a further limit takes us to the delta bose gas which arises in studying moments of the stochastic heat equation / kardar - parisi - zhang equation .
[ section ] [ section ] [ theorem]conjecture [ theorem]lemma [ theorem]proposition [ theorem]corollary [ theorem]claim [ theorem]critical point derivation [ theorem]experimental result # 1 # 1#1 # 1 [ theorem]remark [ theorem]example [ theorem]definition [ theorem]definitions .
And you have already written the first three sentences of the full article: in this work we develop spectral theory for the @xmath0-boson ( stochastic ) particle system - boson totally asymmetric diffusion model while in @xcite it was also referred to as @xmath0-tazrp .
the term `` stochastic '' is included here to differentiate this with the non - stochastic quantum particle system considered in earlier work @xcite under the name @xmath0-bosons . that earlier studied system is a special limit of the more general system presently considered ( see section [ vandiejen ] ) . despite this , in what follows we will generally suppress the term `` stochastic '' , though still always referring to the stochastic particle system ] .
this is an interacting particle system whose generator is a stochastic representation of the generalization of the @xmath0-boson hamiltonian introduced by sasamoto - wadati in 1998 @xcite ( see section [ afortiori ] for more details ) ..
Please generate the next two sentences of the article | the system ( in fact , a totally asymmetric zero range process ) consists of @xmath1 particles on @xmath2 with locations labeled by @xmath3 . in continuous time , each cluster of particles with the same location transfers one particle to the left by one at rate @xmath4 , where @xmath5 is the size of the cluster and @xmath0 is a parameter fixed between 0 and 1 . in order to preserve the ordering of @xmath6 ,
the highest index particle in a cluster is always the one which moves left . |
7,892 | Suppose that you have an abstract for a scientific paper: we show that two tight binding electrons that repel may form a bounded pair in two dimensions .
the paired states form a band with energies that scale like the strength of the interaction potential . by applying an electric field
we show that the dynamics of such states is that of a composite particle of charge 2e .
the system still sustains bloch - like states , so that if the two bands overlap single and paired states might coexist allowing for a bosonic fluid component that , if condensed , would decrease the resistance at low temperatures .
the presence of two bands allows for new oscillations whose experimental detection would permit a direct measurement of the interaction potential strength . .
And you have already written the first three sentences of the full article: bound states are normally associated with basins of attraction , and it is always surprising to find them in the presence of a repulsive interaction .
the most remarkable case is the pairing of electrons in normal superconductors , mediated by lattice distortions .
a new kind was recently observed for ultracold rubidium atoms in an optical lattice [ 1 ] , where the binding arises from pure quantum interference ..
Please generate the next two sentences of the article | the pairs were shown to be stable , thus suggesting that they might form a superfluid phase if the composite is a boson .
the effect was originally predicted for a one dimensional string [ 2 - 5 ] . |
7,893 | Suppose that you have an abstract for a scientific paper: we give a survey of recent classification results for von neumann algebras @xmath0 arising from measure preserving group actions on probability spaces .
this includes ii@xmath1 factors with uncountable fundamental groups and the construction of w@xmath2-superrigid actions where @xmath0 entirely remembers the initial group action @xmath3 .
primary 46l36 ; secondary 46l40 , 28d15 , 37a20 .
von neumann algebra , ii@xmath1 factor , measure preserving group action , fundamental group of a ii@xmath1 factor , outer automorphism group , w@xmath2-superrigidity . .
And you have already written the first three sentences of the full article: a von neumann algebra is a an algebra of bounded linear operators on a hilbert space that is closed under the adjoint @xmath4-operation and that is closed in the weak operator topology .
von neumann algebras arise naturally in the study of groups and their actions on measure spaces .
these constructions go back to murray and von neumann s seminal papers ( * ? ? ?.
Please generate the next two sentences of the article | * chapter xii ) and @xcite .
* if @xmath5 is a countable group , the left translation unitary operators on @xmath6 generate the _ group von neumann algebra _ @xmath7 . |
7,894 | Suppose that you have an abstract for a scientific paper: we revisit the problem of entanglement of thermal equilibrium states of composite systems .
we introduce characteristic , viz .
critical , temperatures and bounds for them marking transitions from entanglement to separability .
we present examples for the various possible thermal entanglement scenarios in bipartite qubit / qubit and qubit / qutrit systems . .
And you have already written the first three sentences of the full article: consider a finite composite quantum system described by the complex hilbert space @xmath0 , which is the tensor product of @xmath1 ( @xmath2 ) finite dimensional hilbert spaces @xmath3 of dimension @xmath4 ( @xmath5 ) ; and has dimension @xmath6 .
given any hamiltonian @xmath7 acting on @xmath8 , the thermal equilibrium ( or gibbs ) state @xmath9 for temperature @xmath10 is @xmath11 .
since the quantum system is assumed to be finite , negative temperatures are possible , but they will be disregarded here for reasons of economy although the effects described below are also present for negative temperatures ..
Please generate the next two sentences of the article | + since the system has components , the question of the entanglement of the gibbs - states arises .
we recall that an arbitrary state @xmath12 ( mixed or pure ) of the composite system is said to be _ |
7,895 | Suppose that you have an abstract for a scientific paper: the inhomogeneous structure of a fluid at a wall can be characterized in several ways . within a thermodynamic description
the surface free energy @xmath0 and the excess adsorption @xmath1 are of central importance . for theoretical studies
closed expression of @xmath0 and @xmath1 can be very valuable ; however , even for a well - studied model system such as a hard - sphere fluid at a planar hard wall , the accuracy of existing expressions for @xmath0 and @xmath1 , compared to precise computer simulation data , can still be improved . here , we compare several known expressions for @xmath0 and @xmath1 to the most precise computer simulation data .
while good agreement is generally found at low to intermediate fluid densities , the existing parameterizations show significant deviation at high density . in this work ,
we propose new parameterizations for @xmath0 and @xmath1 that agree with the simulation data within statistical error over the entire fluid density range . .
And you have already written the first three sentences of the full article: the hard - sphere fluid at a hard wall is a useful reference model for the solid - liquid interface between chemically dissimilar materials .
its simple , but non - trivial , nature has made it a standard reference model to test theories of inhomogeneous fluids , such as integral equation theories and classical density - functional theories . as such , there have been a large number of simulation efforts to study the detailed thermodynamics and structure of this system , both to provide data for the testing of theoretical methods and to provide insight into the generic phenomenology of solid - liquid interfaces .
of particular interest in such studies is the surface free energy , @xmath0 , which measures the work required to create a unit area of interface , and the excess adsorption , @xmath1 , which measures the number of particles in the interfacial region relative to that in a region of equal volume in the bulk . in terms of the single - particle density profile , @xmath2 ,.
Please generate the next two sentences of the article | the excess adsorption is given by @xmath3\ ; dz\ ] ] where @xmath4 is the bulk fluid density and @xmath5 is the cartesian coordinate normal to the surface .
the excess adsorption and the surface free energy are related through the gibbs adsorption equation @xmath6 where @xmath7 is the chemical potential . |
7,896 | Suppose that you have an abstract for a scientific paper: we observe the past and present of the universe , but can we predict the far future ?
observations suggest that in thousands of billions of years from now most matter and radiation will be absorbed by the cosmological horizon .
as it absorbs the contents of the universe , the cosmological horizon is pushed further and further away . in time , the universe asymptotes towards an equilibrium state of the gravitational field .
flat minkowski space is the limit of this process .
it is indistinguishable from a space with an extremely small cosmological constant ( @xmath0 ) and thus has divergent entropy . .
And you have already written the first three sentences of the full article: if we ignored gravitational entropy , we would think that the early universe had high entropy because it was uniform and hot @xcite , and that the cold and clumpy universe of today has low entropy .
the evolution of the universe would then violate the second law of thermodynamics , which states that entropy never decreases .
however , gravitational entropy can not be ignored because it increases with clumpiness and ends up dominating the other forms of entropy ..
Please generate the next two sentences of the article | gravitational entropy is usually identified with a quarter the area of a horizon , which suggests that the entropy arises in some way from the information that the horizon hides from us . in the case of the cosmological horizon , the expansion of the universe carries the distant object beyond contact with observers from within the horizon . in the black hole case
, the composition of an object is forgotten once it falls into the hole , and only a few macroscopic variables - mass , spin , and charge - remain . |
7,897 | Suppose that you have an abstract for a scientific paper: because _ spitzer _ is an earth - trailing orbit , losing about 0.1 au / yr , it is excellently located to perform microlens parallax observations toward the magellanic clouds ( lmc / smc ) and the galactic bulge .
these yield the so - called `` projected velocity '' of the lens , which can distinguish statistically among different populations .
a few such measurements toward the lmc / smc would reveal the nature of the lenses being detected in this direction ( dark halo objects , or ordinary lmc / smc stars ) .
cool _ spitzer _ has already made one such measurement of a ( rare ) bright red - clump source , but warm ( presumably less oversubscribed ) _ spitzer _ could devote the extra time required to obtain microlens parallaxes for the more common , but fainter , turnoff sources . warm _ spitzer _ could observe bulge microlenses for 38 days per year , which would permit up to 24 microlens parallaxes per year .
this would yield interesting information on the disk mass function , particularly old brown dwarfs , which at present are inaccessible by other techniques .
target - of - opportunity ( too ) observations should be divided into rtoo / dtoo , i.e. , `` regular '' and `` disruptive '' toos , as pioneered by the _ space interferometry mission ( sim)_. lmc / smc parallax measurements would be dtoo , but bulge measurements would be rtoo , i.e. , they could be scheduled in advance , without knowing exactly which star was to be observed . .
And you have already written the first three sentences of the full article: microlens parallaxes measure a vector quantity , the `` projected velocity '' @xmath0 , which is the projection of the lens - source relative velocity on the plane of the observer .
another way of writing this quantity is @xmath1 where @xmath2 and @xmath3 are the lens - source relative parallax and proper motion .
it is a useful quantity to measure because it depends only on the kinematic properties of the lens and source , and is independent of the mass ..
Please generate the next two sentences of the article | once it is measured , one can also determine the projected einstein radius " , @xmath4 where @xmath5 is the einstein timescale " ( which is almost always well - measured ) and @xmath6 .
hence , an ensemble microlens parallax measurements can distinguish statistically between different kinematic populations . |
7,898 | Suppose that you have an abstract for a scientific paper: in this paper , the problem of compressible flow over a thin airfoil located near the ground is studied .
a singular integral equation , also known as possio equation @xcite , that relates the pressure jump along the airfoil to its downwash is derived .
the derivation of the equation utilizes laplace transform , fourier transform , method of images , and theory of mikhlin multipliers .
the existence and uniqueness of solution to the possio equation is verified for the steady state case and an approximate solution is obtained .
the aerodynamic loads are then calculated based on the approximate solution .
moreover , the divergence speed of a continuum wing structure located near the ground is obtained based on the derived expressions for the aerodynamic loads .
department of mathematics and statistics + american university of sharjah + sharjah , uae + e - mail : mohamedserry91100gmail.com + e - mail : atufaha100aus.edu .
And you have already written the first three sentences of the full article: in the last few decades , the fields of aerodynamics and aero - elasticity have bloomed significantly due to advances in computation power and experimentation . as a result ,
the implementation of analytical methods has receded slightly . despite their limitations ,
analytical techniques have contributed significantly in the development of the fields of aerodynamics and aero - elasticity ..
Please generate the next two sentences of the article | an important example is the pioneering work of theodorsen @xcite who derived closed form expressions of the aerodynamic loads on thin airfoils in incompressible flow using tools from complex analysis . despite the relative simplicity of the expressions derived by theodorsen
, they have been intensively used by a significant number of researchers to study the aero - elastic stability and control of wing structures ( see for example @xcite ) . |
7,899 | Suppose that you have an abstract for a scientific paper: we describe an imbalanced superfluid fermi gas in three dimensions within the path - integral framework . to allow for the formation of the fulde - ferell - larkin - ovchinnikov - state ( fflo - state ) , a suitable form of the saddle - point
is chosen , in which the pairs have a finite centre - of - mass momentum . to test the correctness of this path - integral description
, the zero - temperature phase diagram for an imbalanced fermi gas in three dimensions is calculated , and compared to recent theoretical results .
subsequently , we investigate two models that describe the effect of imposing a one - dimensional optical potential on the 3d imbalanced fermi gas .
we show that this 1d optical potential can greatly enlarge the stability region of the fflo - state , relative to the case of the 3d fermi gas without 1d periodic modulation .
furthermore it is show that there exists a direct connection between the centre - of - mass momentum of the fflo - pairs and the wavevector of the optical potential .
we propose that this concept can be used experimentally to resonantly enhance the stability region of the fflo - state . .
And you have already written the first three sentences of the full article: the study of superconducting and superfluid systems has recently attracted wide attention , among other things because of the realization of ultracold fermi gasses in optical lattices @xcite .
these systems can be considered as quantum simulators that can be used for probing fundamental problems in condensed - matter physics @xcite , for instance the search for exotic new phases in strongly magnetized superconductors .
ultracold fermi gasses offer important advantages over conventional superconductors , mainly because of their extensive tunability . in a superconductor ,.
Please generate the next two sentences of the article | the number of spin - up and spin - down electrons is equal and the interaction strength is fixed . in ultracold fermi gasses , one can not only tune the interaction strength by use of feshbach resonances @xcite , but also the population imbalance can be freely adapted .
this experimental freedom has led to the study of a variety of new phenomena in imbalanced ultracold fermi gasses @xcite . |
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