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8,000 | Suppose that you have an abstract for a scientific paper: schrodinger suggested that thermodynamical functions can not be based on the gratuitous allegation that quantum - mechanical levels ( typically the orthogonal eigenstates of the hamiltonian operator ) are the only allowed states for a quantum system [ e. schrodinger , statistical thermodynamics ( courier dover , mineola , 1967 ) ] .
different authors have interpreted this statement by introducing density distributions on the space of quantum pure states with weights obtained as functions of the expectation value of the hamiltonian of the system . in this work we focus on one of the best known of these distributions , and we prove that , when considered in composite quantum systems , it defines partition functions that do not factorize as products of partition functions of the noninteracting subsystems , even in the thermodynamical regime .
this implies that it is not possible to define extensive thermodynamical magnitudes such as the free energy , the internal energy or the thermodynamic entropy by using these models .
therefore , we conclude that this distribution inspired by schrdinger s idea can not be used to construct an appropriate quantum equilibrium thermodynamics . .
And you have already written the first three sentences of the full article: in a note to the second edition of his book on statistical thermodynamics @xcite , schrdinger suggests that thermodynamical functions can not be based on the gratuitous allegation that quantum - mechanical levels ( typically the orthogonal eigenstates of the hamiltonian operator ) are the only allowed states in statistical thermodynamics . in khinchin s classical book on the mathematical foundations of quantum statistics ( sec .
2 of chap iii of @xcite ) an approach to microcanonical averages is proposed in line with schrdinger s suggestion .
landau and lifshitz @xcite also consider unrealistic the possibility of preparing isolated macroscopic physical systems in a precise energy eigenstate , since energy levels are too close to each other to select just one . from these points of view.
Please generate the next two sentences of the article | , it seems then natural to consider the description of quantum statistical systems in terms of probability densities defined on the space of physical states .
this description offers the possibility of considering the weight of a given state in an analogous manner to what it is done when describing classical statistical systems . |
8,001 | Suppose that you have an abstract for a scientific paper: we derive a new set of sum rules between the neutrino mass and mixing parameters in vacuum and their effective counterparts in matter .
the moduli of nine genuine lepton mixing matrix elements can then be calculated in terms of the matter - corrected ones , and the latter can directly be determined from a variety of long - baseline neutrino oscillations .
we show that it is possible to reconstruct the leptonic unitarity triangles and cp violation in a similar parametrization - independent way . .
And you have already written the first three sentences of the full article: thanks to the super - kamiokande @xcite and sno @xcite experiments , both solar and atmospheric neutrino oscillations are convincingly established .
it turns out that neutrinos _
do _ have masses and lepton flavors are really mixed , just as expected in some grand unified theories ..
Please generate the next two sentences of the article | two neutrino mass - squared differences and three lepton mixing angles have been measured or constrained by current neutrino oscillation data @xcite .
a more precise determination of these parameters has to rely on the new generation of accelerator neutrino experiments with very long baselines @xcite , in which leptonic cp violation may also be observed . |
8,002 | Suppose that you have an abstract for a scientific paper: emergence of neutrino physics is fueled by the recent growth in quality and quantity of experimental data , yet , there are still open questions . how much can the determination of mixing parameters be improved ?
can we improve bounds on @xmath0 before experiments designed specifically for this parameter start ? how well can we determine or limit sterile fraction of neutrino flux from sun and sterile mixing angle ?
we examine the impact of outcome from new measurements in the context of providing answers to these questions .
[ [ section ] ] it is well established that , solar neutrinos primarily change into another active flavor@xcite .
experimental evidences from solar@xcite , atmospheric@xcite , reactor@xcite and long - baseline@xcite experiments can be accommodated into the framework of neutrino mass , oscillations , and neutrino mixing . in this formalism
, it is known that solar mixing angle , @xmath1 , is large@xcite , but not maximal , and atmospheric mixing angle , @xmath2 , is large , even maximal .
matter effects probably plays a role in this transformation@xcite .
the size of the third mixing angle , @xmath0 , is currently best limited by combined chooz reactor experiment and sk atmospheric data . in fig .
[ fig:1 ] , we present bounds on @xmath0 under certain considerations .
the horizontal shaded regions are 90% c. l. and 99% c. l. bounds on @xmath3 from superk atmospheric data .
the thick ( thin ) dashed curve is the 90% c. l. ( 3@xmath4 ) chooz bound . the 99% c. l. region on @xmath3 extends as low as @xmath5ev@xmath6 .
at the lower end of this region , @xmath0 is poorly constrained by chooz .
the solid curves in fig .
[ fig:1 ] are bounds from from chooz , kamland and solar data at 90% c. l. and 3@xmath4 .
our analysis shows that , the upper bound on @xmath0 from kamland and solar neutrino data gets stronger ( especially in the region with small @xmath7 where chooz reactor bound is relatively weak ) , and even dominates as this data gets refined .....
And you have already written the first three sentences of the full article: i thank a. b. balantekin , v. barger , d. marfatia and s. pakvasa for collaboration and a. b. mcdonald for useful conversations .
this work was supported in part by the nsf grant no .
phy-0244384 and the wisconsin alumni research foundation . 0 s. n. ahmed _ et al ..
Please generate the next two sentences of the article | _ [ sno collaboration ] , phys . rev .
lett . * 92 * , 181301 ( 2004 ) . |
8,003 | Suppose that you have an abstract for a scientific paper: we obtain a large class of lorentzian wormhole spacetimes in scalar - tensor gravity , for which the matter stress energy does satisfy the weak energy condition .
our constructions have zero ricci scalar and an everywhere finite , non - zero scalar field profile . interpreting the scalar - tensor gravity as an effective on - brane theory resulting from a two - brane randall sundrum model of warped extra dimensions , it is possible to link wormhole existence with that of extra dimensions .
we study the geometry , matter content , gravitational red - shift and circular orbits in such wormholes and argue that our examples are perhaps among those which may have some observational relevance in astrophysics in future .
we also study traversability and find that our wormholes are indeed traversable for values of the metric parameters satisfying the weak energy condition . .
And you have already written the first three sentences of the full article: curved spacetimes for which the ricci scalar @xmath0 is identically zero have been known in general relativity ( gr ) since the discovery of the schwarzschild solution . while , in gr , the schwarzschild is a vacuum spacetime for which both @xmath0 and @xmath1 are zero , the reissner - nordstrom geometry has @xmath2 but @xmath3 , thereby implying the presence of traceless matter .
it has been further shown in @xcite that a generalisation of schwarzschild spacetime with @xmath4 everywhere finite and non - zero and @xmath2 can be obtained .
more recently @xcite , this @xmath2 wormhole spacetime has been found to be a solution in a scalar - tensor theory of gravity which is also the low energy , effective , on - brane gravity theory for the warped two - brane randall - sundrum model ..
Please generate the next two sentences of the article | the @xmath2 spacetime in @xcite when viewed as a solution in gr , requires matter that violates the weak energy condition ( wec ) .
however , as shown in @xcite , in the context of the scalar - tensor theory , the required matter does not violate the wec and the scalar field ( radion ) is also finite and non - zero everywhere . in our work here , |
8,004 | Suppose that you have an abstract for a scientific paper: using data from the southern galactic plane survey we have measured the spatial power spectrum of the interstellar neutral atomic hydrogen in the fourth galactic quadrant .
this function shows the same power law behavior that has been found for hi in the second quadrant of the milky way and in the magellanic clouds , with the same slope .
when we average over velocity intervals broader than the typical small - scale velocity dispersion , we find that the slope steepens , from @xmath0 to @xmath1 for the warm gas , as predicted by theories of interstellar turbulence if the column density fluctuations are dominated by variations in the gas density on small spatial scales .
the cool gas shows a different increase of slope , that suggests that it is in the regime of turbulence dominated by fluctuations in the velocity field .
overall , these results confirm that the small scale structure and motions in the neutral atomic medium are well described by a turbulent cascade of kinetic energy . .
And you have already written the first three sentences of the full article: the structure of the density and velocity fields in the interstellar medium ( ism ) has been studied using a variety of tracers , from spectral lines in emission and absorption to pulsar scintillation and faraday rotation .
a particularly convenient tracer is the 21-cm line of hi because it is very widespread and easily detectable from both dense and diffuse clouds and from the `` intercloud '' or warm neutral medium .
two sorts of structure are traced with this line : deterministic and stochastic ..
Please generate the next two sentences of the article | the former are coherent features in the density and/or velocity fields that can be interpreted dynamically as evolving physical structures , like shells , bubbles , chimneys , clouds , or streams .
the latter are apparently random variations in the density of the gas as a function of position and velocity , that can best be characterized statistically . |
8,005 | Suppose that you have an abstract for a scientific paper: the affleck - dine leptogenesis scenario along the @xmath0 flat direction is reconsidered .
it is known that successful affleck - dine leptogenesis requires that the lightest neutrino mass is extremely small .
this situation can be significantly relaxed if the neutrino mass in the early universe is different from the present one .
we consider a supersymmetric dine - fischler - srednicki - zhitnitsky ( dfsz ) type model , which provides a solution to the strong @xmath1 problem and generates a susy @xmath2-term and right - handed neutrino masses .
if the pq scale during lepton number generation is much larger than the present value , leptogenesis is very efficient so that enough baryon number can be generated without introducing a hierarchically small neutrino mass .
the final baryon asymmetry is related to the @xmath2-term , and hence linked to the level of electroweak fine tuning .
we also show the pq breaking scalar dynamics that keeps a large pq breaking scale during inflation and lepton number generation .
the @xmath2-term generating superpotential plays an important role for preserving the lepton asymmetry during saxion oscillation . in this scenario ,
the axion isocurvature perturbation is naturally suppressed .
ctpu-16 - 44 ut-16 - 37 ipmu-16 - 0190 .
And you have already written the first three sentences of the full article: the baryon asymmetry of the universe ( bau ) is one of the intriguing puzzles in our understanding of the universe . in order to generate the bau ,
three conditions , which have been pointed out by sakharov @xcite , need to be satisfied in the early universe : baryon number ( @xmath3 ) violation , @xmath4/@xmath1 violation and departure from equilibrium .
the @xmath3-violation is actually replaced by @xmath5-violation since the @xmath5-conserving and @xmath6-violating sphaleron process can easily transfer @xmath3 number into @xmath7 number and _ vice versa _ before the electroweak phase transition @xcite ..
Please generate the next two sentences of the article | while several ideas have been proposed to produce bau by using @xmath3-violating interactions , leptogenesis provides a different mechanism for generating bau by using @xmath7-violating interactions @xcite .
in such a case , instead of a baryon asymmetry , a lepton asymmetry is generated in the early universe via @xmath7-violating interactions . |
8,006 | Suppose that you have an abstract for a scientific paper: we studied the possibility of exciton condensation in mott insulating bilayers . in these strongly correlated systems
an exciton is the bound state of a double occupied and empty site . in the strong coupling limit
the exciton acts as a hard - core boson .
its physics are captured by the exciton @xmath0 model , containing an effective @xmath1 model describing the exciton dynamics only . using numerical simulations and analytical mean field theory we constructed the ground state phase diagram .
three homogeneous phases can be distinguished : the antiferromagnet , the exciton checkerboard crystal and the exciton superfluid . for most model parameters ,
however , we predict macroscopic phase separation between these phases .
the exciton superfluid exists only for large exciton hopping energy .
additionally we studied the collective modes and susceptibilities of the three phases . in the superfluid phase
we find the striking feature that the bandwidth of the spin - triplet excitations , potentially detectable by resonant inelastic x - ray scattering ( rixs ) , is proportional to the superfluid density .
the superfluid phase mode is visible in the charge susceptibility , measurable by rixs or electron energy loss spectroscopy ( eels ) . .
And you have already written the first three sentences of the full article: strongly correlated electron systems exhibit the highest attained superconducting transition temperatures currently known , and a rich variety of complex electronic phases@xcite .
many compounds among this family of mott insulators , such as the cuprates , are quasi - two - dimensional layered materials .
this renders them ideal candidates for bilayer exciton condensation , which is the topic of this publication ..
Please generate the next two sentences of the article | the effort to achieve the condensation of excitons has a long history starting just after the discovery of bcs theory@xcite .
an exciton is the bound state of an electron and a hole and as such it can bose condense . the obvious advantage of considering excitons above cooper pairs is the strong coulomb attraction between the electron and the hole ; allowing in principle for a much higher critical temperature . to reduce the exciton lifetime problems caused by electron - hole recombination |
8,007 | Suppose that you have an abstract for a scientific paper: observations of molecular clouds in the gamma ray domain provide us with a tool to study the distribution of cosmic rays in the galaxy .
this is because cosmic rays can penetrate molecular clouds , undergo hadronic interactions in the dense gas , and produce neutral pions that in turn decay into gamma rays .
the detection of this radiation allows us to estimate the spectrum and intensity of cosmic rays at the cloud s position .
remarkably , this fact can be used to constrain the cosmic ray diffusion coefficient at specific locations in the galaxy .
galactic cosmic rays ( crs ) are believed to be accelerated by supernova remnants ( snrs).@xcite the main ( but not conclusive ) arguments supporting this idea are the fact that snrs can provide the total power required to maintain the galactic cr population , and the belief that an efficient acceleration mechanism , diffusive shock acceleration @xcite , operates in these objects .
the detection of some snrs in tev gamma rays @xcite , expected if they indeed are the sources of crs @xcite , also supports this scenario , though the emission might have a leptonic origin and not be related to the acceleration of crs .
@xcite besides the total cr power of the galaxy , a theory of cr origin must also explain the spectrum , isotropy , and chemical composition of crs.@xcite this requires a thorough knowledge not only of the nature of cr sources , but also of the way in which crs propagate in the galaxy .
this is because the observed properties of crs results from the equilibrium between the injection rate of crs from sources and their diffusive escape from the galaxy
. measurements of the amount of spallation suffered by crs allow us to infer the average residence time of a cr of energy @xmath0 in the galaxy as @xmath1 , with @xmath2 .
if @xmath3 is the length a cr has to move away from its source before escaping the galaxy ( i.e. the galaxy s thickness ) , then the diffusion coefficient reads : @xmath4 .
however , this has to be intended as....
And you have already written the first three sentences of the full article: consider a mc with mass @xmath5 at a distance @xmath6 , located in a region in the galaxy where the cr ( protons ) intensity is @xmath7 . for illustrative purpose , we set here @xmath8 .
we further assume that the high energy crs ( the ones with energy above the threshold for @xmath9-production ) can freely penetrate the cloud@xcite . under these assumptions the expected gamma ray flux from the mc due to proton - proton interactions
is given by : @xmath10 where @xmath11 is the interaction cross section , @xmath12 is the proton mass , and @xmath13 depends on @xmath14 and is tabulated in ref . ..
Please generate the next two sentences of the article | equation [ flux ] is valid at high energies only ( @xmath15 ) , while at lower energies the spectrum ( in log - log scale ) is symmetric with respect to the energy @xmath16 .
assume now that the cr intensity in the region under exam differs by a factor @xmath17 from the one measured at the earth ( which is:@xcite @xmath18 ) , so that equation [ flux ] can be rewritten as : @xmath19 where @xmath20 is the mass of the mc in units of @xmath21 , @xmath22 is the distance in kpc , and @xmath23 takes into account the fact that on average crs with energy @xmath0 produce gamma rays with energy @xmath24 . |
8,008 | Suppose that you have an abstract for a scientific paper: the galaxy clusters exhibit noticeably anisotropic pattern in their clustering , which is vividly manifested by the presence of rich filament - like superclusters .
the more anisotropic the clustering of galaxy clusters is , the more straight the rich filament - like superclusters become . given that the degree of the anisotropy in the largest - scale clustering depends sensitively on the nature of dark energy , the supercluster straightness may play a complimentary role in testing dynamic dark energy models . here
we focus on the coupled dark energy ( cde ) models which assume the existence of dark sector coupling between scalar field dark energy and nonbaryonic dark matter . determining the spines of the superclusters identified in the publicly available group catalogs from the codecs ( coupled dark energy cosmological simulations ) for four different cde models as well as for the @xmath0cdm model , we quantify the straightness of each supercluster as the spatial extent of its spine per member cluster where a supercluster spine represents the main stem of the minimal spanning tree constructed out of the member clusters .
it is shown that the dark sector coupling plays a role in making the supercluster less straight relative to the @xmath0cdm case and that in a cde model with supergravity potential the superclusters are least straight .
we also find that the difference in the degree of the supercluster straightness between the cde and the @xmath0cdm cases increases with redshifts .
a physical interpretation of our result as well as its cosmological implication are discussed . .
And you have already written the first three sentences of the full article: the meticulous analysis of the cmb ( cosmic microwave background ) temperature power spectrum done by the planck mission team has casted both light and shadow on the status of the @xmath0cdm ( cosmological constant @xmath0 + cold dark matter ) cosmology . while at high multipoles ( @xmath1 the @xmath0cdm cosmology is found perfect in matching the observational data , at low multipoles ( @xmath2 ) its poor - fits has been confirmed not as numerical flukes but likely to be real @xcite .
given that the low - multipole behavior of the cmb temperature spectrum reflects the most primordial feature of the universe , the planck result along with the infamous long - standing problem associated with @xmath0 may imply the incompleteness of the @xmath0cdm cosmology , encouraging the cosmologists to search more strenuously than ever for physical alternatives .
the coupled dark energy ( cde ) models where dark energy is not the inert @xmath0 but a dynamic scalar field coupled to nonbaryonic dark matter particles @xcite have recently attained probing attention because of their capacity for accommodating several observational mysteries that the @xmath0cdm cosmology could not resolve . for instance , according to @xcite , the high-@xmath3 massive clusters regarded as extremely rare events in the @xmath0cdm universe ( e.g. , see * ? ? ? * and references therein ) are more probable to detect in the cde models ..
Please generate the next two sentences of the article | @xcite demonstrated that the cde models can explain the observed higher degree of the misalignment between the spatial distributions of cluster galaxies and dark matter than naturally expected in the @xmath0cdm cosmology @xcite . in the work of @xcite ,
the morphological properties of the observed bullet cluster @xcite that had been found to be in a serious tension with the prediction of the @xmath0cdm cosmology @xcite were much less anomalous in cde models . |
8,009 | Suppose that you have an abstract for a scientific paper: we discuss the three - body decays @xmath0 , @xmath1 , @xmath2 , and @xmath3 ( @xmath4 ) of the lighter top squark @xmath5 within the minimal supersymmetric standard model .
we give the complete analytical formulas for the decay widths and present a numerical study in view of an upgraded tevatron , the cern lhc , and a future lepton collider demonstrating the importance of these decay modes . .
And you have already written the first three sentences of the full article: the search for supersymmetry ( susy ) @xcite plays an important rle in the experimental program at the colliders lep2 and tevatron
. it will be even more important at future colliders , e.g. an upgraded tevatron , lhc , an @xmath6 linear collider or a @xmath7 collider . therefore many phenomenological studies have been carried out in recent years ( see e.g. @xcite and references therein ) . within the supersymmetric extensions of the standard model ( sm ) the minimal supersymmetric standard model ( mssm )
@xcite is the most investigated one ..
Please generate the next two sentences of the article | the mssm implies that every sm fermion has two spin 0 partners called sfermions @xmath8 and @xmath9 .
in general sfermions decay according to @xmath10 where @xmath11 and @xmath12 denote neutralinos and charginos , respectively . here |
8,010 | Suppose that you have an abstract for a scientific paper: we obtain an exact solution for the breather lattice solution of the modified korteweg - de vries ( mkdv ) equation .
numerical simulation of the breather lattice demonstrates its instability due to the breather - breather interaction .
however , such multi - breather structures can be stabilized through the concurrent application of ac driving and viscous damping terms . * breather lattice and its stabilization for the modified korteweg - de vries equation * .
And you have already written the first three sentences of the full article: there are many physical systems where the @xmath0 mkdv equation @xcite appears , e.g. phonons in anharmonic lattices @xcite , ion acoustic solitons @xcite and van alfvn waves in collisionless plasma @xcite , schottky barrier transmission lines @xcite as well as in the models of traffic congestion @xcite .
a subclass of hyperbolic surfaces @xcite , slag - metallic bath interfaces @xcite , curve motion @xcite , meandering ocean jets @xcite and other models in fluid mechanics @xcite are also related to the mkdv equation .
furthermore , it has been shown that the dynamics of thin elastic rods can also be reduced to the mkdv equation @xcite ..
Please generate the next two sentences of the article | this equation is also of special interest due to its integrability in the context of nonlinear soliton bearing systems @xcite . from a physical perspective
it is therefore important to examine novel classes of solutions of such partial differential equations and their potential relevance in this diverse class of applications . |
8,011 | Suppose that you have an abstract for a scientific paper: we propose a practical quantum cryptographic scheme which combines high information capacity , such as provided by , with the simplicity of a two - dimensional clauser - horne - shimony - holt ( chsh ) bell test for security verification . by applying a state combining entanglement in a two - dimensional degree of freedom , such as photon polarization , with in another degree of freedom , such as photon orbital angular momentum ( oam ) or path
, the scheme provides a considerably simplified route towards security verification in quantum key distribution ( qkd ) aimed at . .
And you have already written the first three sentences of the full article: cryptography is one of the most promising applications of quantum science @xcite . with the recent demonstrations of high - dimensional two - photon entanglement using time bins
@xcite and oam @xcite , large - alphabet entanglement - based quantum key distribution ( qkd ) systems become closer to their real - world implementations and applications .
the traditional approach to large - alphabet qkd based on bell s theorem involves verifying the security of the generated key using a test of a bell inequality ..
Please generate the next two sentences of the article | this is a straighforward generalization of the original protocol introduced by ekert in 1991 ( e91 ) @xcite and e91-based protocols have been demonstrated for qubits using @xcite and using time - energy entanglement @xcite .
a bell - type test of energy - time entangled qutrits has also been realised @xcite . reported experiments using oam qutrits @xcite have implemented a randomized selection of dichotomous measurements instead of full projective measurements in a 3-dimensional state space . |
8,012 | Suppose that you have an abstract for a scientific paper: we perform a search for gravitational wave bursts using data from the second science run of the ligo detectors , using a method based on a wavelet time - frequency decomposition .
this search is sensitive to bursts of duration much less than a second and with frequency content in the 1001100 hz range .
it features significant improvements in the instrument sensitivity and in the analysis pipeline with respect to the burst search previously reported by ligo .
improvements in the search method allow exploring weaker signals , relative to the detector noise floor , while maintaining a low false alarm rate , @xmath0 @xmath1hz .
the sensitivity in terms of the _ root - sum - square _
( rss ) strain amplitude lies in the range of @xmath2 .
no gravitational wave signals were detected in 9.98 days of analyzed data .
we interpret the search result in terms of a frequentist upper limit on the rate of detectable gravitational wave bursts at the level of 0.26 events per day at 90% confidence level .
we combine this limit with measurements of the detection efficiency for given waveform morphologies in order to yield rate versus strength exclusion curves as well as to establish order - of - magnitude distance sensitivity to certain modeled astrophysical sources . both the rate upper limit and its applicability to signal strengths improve our previously reported limits and reflect the most sensitive broad - band search for untriggered and unmodeled gravitational wave bursts to date . .
And you have already written the first three sentences of the full article: the laser interferometer gravitational wave observatory ( ligo ) is a network of interferometric detectors aiming to make direct observations of gravitational waves .
construction of the ligo detectors is essentially complete , and much progress has been made in commissioning them to ( a ) bring the three interferometers to their final optical configuration , ( b ) reduce the interferometers noise floors and improve the stationarity of the noise , and ( c ) pave the way toward long - term science observations .
interleaved with commissioning , four `` science runs '' have been carried out to collect data under stable operating conditions for astrophysical gravitational wave searches , albeit at reduced sensitivity and observation time relative to the ligo design goals ..
Please generate the next two sentences of the article | the first science run , called s1 , took place in the summer of 2002 over a period of 17 days .
s1 represented a major milestone as the longest and most sensitive operation of broad - band interferometers _ in coincidence _ up to that time . using the s1 data from the ligo and geo600 interferometers @xcite , astrophysical searches for four general categories of gravitational wave source types binary inspiral @xcite , burst - like @xcite , stochastic @xcite and continuous wave @xcite were pursued by the ligo scientific collaboration ( lsc ) . |
8,013 | Suppose that you have an abstract for a scientific paper: we study the phase diagram of the hubbard model in the weak - coupling limit for coexisting spin - density - wave order and spin - fluctuation - mediated superconductivity .
both longitudinal and transverse spin fluctuations contribute significantly to the effective interaction potential , which creates cooper pairs of the quasi - particles of the antiferromagnetic metallic state .
we find a dominant @xmath0-wave solution in both electron- and hole - doped cases . in the quasi - spin triplet channel ,
the longitudinal fluctuations give rise to an effective attraction supporting a @xmath1-wave gap , but are overcome by repulsive contributions from the transverse fluctuations which disfavor @xmath1-wave pairing compared to @xmath0 .
the sub - leading pair instability is found to be in the @xmath2-wave channel , but complex admixtures of @xmath3 and @xmath2 are not energetically favored since their nodal structures coincide .
inclusion of interband pairing , in which each fermion in the cooper pair belongs to a different spin - density - wave band , is considered for a range of electron dopings in the regime of well - developed magnetic order .
we demonstrate that these interband pairing gaps , which are non - zero in the magnetic state , must have the same parity under inversion as the normal intraband gaps .
the self - consistent solution to the full system of five coupled gap equations give intraband and interband pairing gaps of @xmath0 structure and similar gap magnitude . in conclusion
, the @xmath0 gap dominates for both hole and electron doping inside the spin - density - wave phase . .
And you have already written the first three sentences of the full article: pairing of electrons by exchange of spin fluctuations is a popular paradigm proposed for unconventional superconductivity including fe - based superconductors , cuprates , and heavy fermion systems .
since many of these systems exhibit an ordered magnetic phase coexisting with , or in close proximity to , the superconducting phase , a small number of studies have addressed the subsidiary problem of pairing of quasi - particles in the symmetry broken spin - density - wave ( sdw ) phase . while this problem has a long history , recent experimental and theoretical developments have led a number of authors to revisit it.@xcite for the simplest case of a doped one - band hubbard model with standard commensurate @xmath4 ordering , the existence of pairing and its consequences for the symmetry of the superconducting order parameter was initially investigated in a seminal paper by schrieffer _
et al . _ , @xcite where the effective pairing interaction was obtained within the random phase approximation ( rpa ) arising from longitudinal spin fluctuations in the magnetically ordered phase ..
Please generate the next two sentences of the article | these authors neglected the contribution to pairing from the transverse spin fluctuations corresponding to the goldstone mode of the spin symmetry broken state , arguing that while such modes lead to a divergent contribution to the spin susceptibility at the ordering vector @xmath5 , the coherence factors of the sdw phase screen the bare electron - electron interaction vertex , which therefore vanishes at @xmath5 .
soon after , frenkel and hanke @xcite showed that the transverse fluctuations do contribute to the pairing interaction in the same order as the longitudinal fluctuations ; the divergence of the transverse spin susceptibility is eliminated by the coherence factors , but a residual constant interaction remains . for electron - doped cuprates , the one - band hubbard model seems to provide a reasonable minimal model since the doped electrons reside primarily on the copper sites . |
8,014 | Suppose that you have an abstract for a scientific paper: in this work , we present a deformed solutions starting from systems of three coupled scalar fields with super - potential @xmath0 by orbit method . first , we deform the corresponding super - potential and obtain defect solutions .
it is shown that how to construct new models altogether with its defect solutions in terms of the non - deformed model .
therefore , we draw the graph of super - potential and different fields in terms of @xmath1 so we observe that the graphs for deformed and non - deformed cases are changed by the scale . + * keywords:*three scalar fields ; deformation method ; orbit solution + + * pacs number : * 11.10.-z , 11.10.lm , 11.27.+d . .
And you have already written the first three sentences of the full article: as we know the defect structures exist in different branches of physics , such as domain wall , kinks , vertices , monopoles , condensed matter and string theory . in higher space - times dimensions
the defect structures are generated by real scalar fields such that the single real scalar field produce just single defect as kink - like and the double sin - gordon model may create two different defects . on the other hand , models containing two or more real scalar fields can give rise to at least two other classes of systems that produce defect that engender internal structure and those that support junctions of defects . also two and three scalar fields describe the regular hexagonal network , higgs model [ 1 - 5 ] and bent brane in five dimensions [ 6 ] . in other hand for field theories involving two and three real scalar fields ,
the mathematical problem concerning the integrability of equations of motion is much harder , as one deals with a system of two coupled second order nonlinear ordinary differential equations ..
Please generate the next two sentences of the article | also the configuration space shows a distribution of minima that allows for a number of topological sectors .
one way of simplifying the problem is to consider potentials belonging to large class corresponding to bosonic sector of supersymmetric theories . |
8,015 | Suppose that you have an abstract for a scientific paper: we analyse properties of contact networks formed in packings of soft frictionless disks near the unjamming transition .
we construct polygonal tilings and triangulations of the contact network that partitions space into convex regions which are either covered or uncovered .
this allows us to characterize the _ local _ spatial structure of the packing near the transition using well - defined geometric objects .
we construct bounds on the number of polygons and triangulation vectors that appear in such packings .
we study these networks using simulations of bidispersed disks interacting via a one - sided linear spring potential . we find that several underlying geometric distributions are reproducible and display self averaging properties .
we find that the total covered area is a reliable real space parameter that can serve as a substitute for the packing fraction .
we find that the unjamming transition occurs at a fraction of covered area @xmath0 .
we determine scaling exponents of the excess covered area as the energy of the system approaches zero @xmath1 , and the coordination number @xmath2 approaches its isostatic value @xmath3 .
we find @xmath4 and @xmath5 , representing new structural critical exponents .
we use the distribution functions of local areas to study the underlying geometric disorder in the packings .
we find that a finite fraction of order @xmath6 persists as the transition is approached .
= -.7 cm @=11
@=12 [ [ section ] ] starttoctoc .
And you have already written the first three sentences of the full article: as finite sized rigid particles are brought together by increasing their density or by compression , they undergo sharp transitions into globally rigid structures , a phenomenon known as jamming @xcite .
such systems do not in general form periodic spatial patterns associated with crystalline solids , instead they display rigidity in an amorphous fashion .
the physical properties of such amorphous solids are intimately linked with the underlying disorder in their packing . the packing of particles into mechanically rigid structures has been of interest in diverse fields including physics , biology and geology and has wide - ranging industrial applications ..
Please generate the next two sentences of the article | several characteristics of rigid particle packings have been studied experimentally and also via numerical simulations @xcite .
many theoretical studies have focussed on frictionless particles with hard core interactions , and much of our rigorous understanding stems from the study of such systems @xcite . |
8,016 | Suppose that you have an abstract for a scientific paper: new research in acceleration physics leads to growing up the power of charged particles bunches .
existed methods based on interaction of detection devices with bunches do not satisfy our need , because of the fact that new high intensity bunches can damage this devices .
moreover , these methods do not allow analyzing the bunches in real time .
recently new technique based on odri ( optical diffraction radiation interference ) by a bunch at its propagation through the slit was proposed . in this work
the results of theoretical simulations on diffraction radiation , in particular odri , by electrons for various slit systems as well as the comparison with the desy experimental data are presented .
pacs : 41.60.-m , 29.27.-a , 41.75.ht , 07.77.ka .
And you have already written the first three sentences of the full article: as known , a charged particle emits electromagnetic radiation at its acceleration independently on the origin of this acceleration @xcite .
this phenomenon well studied both theoretically and experimentally , moreover , for more then 50 years it has been used within various branches of the science , from the basic research ( acceleration physics , particle physics , etc . )
to many applications as a source of radiation ( synchrotron and undulator radiations , free electron lasers , applications in material sciences , chemistry , biology , medicine , etc . ) . however , a charged particle can emit electromagnetic radiation even without its acceleration , in presence of various media , for instance ..
Please generate the next two sentences of the article | the pioneering works on this radiation brings us to the discovery by p. cherenkov and s. vavilov , presently known as cherenkov ( or cherenkov - vavilov ) radiation , the origin of which was first suggested within the phenomenology developed by their colleagues i. tamm and i. frank @xcite .
this radiation is emitted when a charged particle crosses the media with the velocity exceeding the speed of light in media . |
8,017 | Suppose that you have an abstract for a scientific paper: we have mapped the emission - line flux distributions and ratios as well as the gaseous kinematics of the inner 450 pc radius of the seyfert 1 galaxy mrk766 using integral field near - ir j- and k@xmath0-band spectra obtained with the gemini nifs at a spatial resolution of 60 pc and velocity resolution of 40 kms@xmath1 .
emission - line flux distributions in ionized and molecular gas extend up to @xmath2 300 pc from the nucleus .
coronal [ six]@xmath3 m line emission is resolved , being extended up to 150 pc from the nucleus . at the highest flux levels ,
the [ feii]@xmath41.257@xmath5 m line emission is most extended to the south - east , where a radio jet has been observed.the emission - line ratios [ feii]@xmath6m/@xmath7 and @xmath8m / br@xmath9 show a mixture of starburst and seyfert excitation ; the seyfert excitation dominates at the nucleus , to the north - west and in an arc - shaped region between 02 and 06 to the south - east at the location of the radio jet . a contribution from shocks at this location
is supported by enhanced [ feii]/[pii ] line ratios and increased [ feii ] velocity dispersion .
the gas velocity field is dominated by rotation that is more compact for h@xmath10 than for pa@xmath11 , indicating that the molecular gas has a colder kinematics and is located in the galaxy plane .
there is about 10@xmath12 m@xmath13 of hot h@xmath10 , implying @xmath2 10@xmath14 m@xmath13 of cold molecular gas . at the location of the radio jet
, we observe an increase in the [ feii ] velocity dispersion ( 150 km s@xmath1 ) , as well as both blueshift and redshifts in the channel maps , supporting the presence of an outflow there .
the ionized gas mass outflow rate is estimated to be @xmath2 10 m@xmath13 yr@xmath1 , and the power of the outflow @xmath2 0.08 l@xmath15 .
[ firstpage ] galaxies : individual ( mrk766 ) galaxies : active galaxies : seyfert galaxies : nuclei galaxies : kinematics and dynamics .
And you have already written the first three sentences of the full article: the study of the extended emission in the narrow - line region ( nlr ) around nearby active galactic nuclei ( agn ) allows the investigation of both the agn feeding via gas inflows ( e.g. * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
* ; * ? ? ? |
8,018 | Suppose that you have an abstract for a scientific paper: applying large magnetic fields to gain access to the hyperfine paschen - back regime can isolate three - level systems in a hot alkali metal vapors , thereby simplifying usually complex atom - light interactions .
we use this method to make the first direct measurement of the @xmath0 matrix element in @xmath1rb . an analytic model with only three levels
accurately models the experimental electromagnetically induced transparency spectra and extracted rabi frequencies are used to determine the dipole matrix element .
we measure @xmath2 which is in excellent agreement with the theoretical calculations of safronova , williams , and clark [ phys .
rev .
a * 69 * , 022509 ( 2004 ) ] . .
And you have already written the first three sentences of the full article: understanding coherent atom - light interactions in multi - level atomic media continues to be the focus of much attention , with an increasing variety of applications .
phenomena such as electromagnetically induced transparency ( eit ) @xcite , coherent population trapping ( cpt ) @xcite , and four - wave mixing ( fwm ) have been instrumental in the development of atomic clocks @xcite , magnetometers @xcite , sub- and super - luminal propagation of light @xcite , quantum memories @xcite , photonic phase gates @xcite , single - photon sources @xcite , and squeezed states of light @xcite .
quantitative modeling for thermal ensembles remains difficult due to the complex atomic energy - level structure ..
Please generate the next two sentences of the article | in contrast , there has been much recent progress in quantitative modeling of linear systems both in terms of fundamental physics and applications @xcite . a recent experiment @xcite demonstrated that applying a large magnetic field can greatly simplify spectroscopic measurements , allowing the isolation of pure two - level systems even in hot atomic vapors where the doppler broadening is significantly larger than the natural linewidth . here
we show this can be extended to two - photon excitation which , in a similar way , isolates pure three - level systems and thereby allows accurate modeling of eit spectra . as a demonstration we use this method to make the first direct measurement of the @xmath0 matrix element in @xmath1rb . |
8,019 | Suppose that you have an abstract for a scientific paper: in this paper , we propose a mean - field model which attempts to bridge the gap between random boolean networks and more realistic stochastic modeling of genetic regulatory networks .
the main idea of the model is to replace all regulatory interactions to any one gene with an average or effective interaction , which takes into account the repression and activation mechanisms .
we find that depending on the set of regulatory parameters , the model exhibits rich nonlinear dynamics .
the model also provides quantitative support to the earlier qualitative results obtained for random boolean networks . *
pacs : * 05.45.-a ; 87.16.yc institute for biocomplexity and informatics university of calgary 2500 university drive nw , calgary alberta , t2n 1n4 , canada .
And you have already written the first three sentences of the full article: since its proposal , the random boolean network model [ 1 ] has successfully described in a qualitative way several important aspects of gene regulation and cell differentiation processes ( for references see [ 2 ] ) .
the model is constructed by assigning to each of the genes its regulatory inputs from among the large number of genes present in the network .
the model consists of @xmath0 binary variables , corresponding to the two states of gene expression ( off and on ) . in this binary setting , each gene is assigned a logical function on its inputs showing its next activity . while clearly an idealization , much has been learned from this class of large boolean networks , and major features generalize to a class of piecewise linear differential equations [ 3 - 4 ] and a family of polynomial maps [ 5 ] ..
Please generate the next two sentences of the article | the research on complex boolean networks , shows that networks behave in three regimes : ordered , critical and chaotic [ 6 ] .
it is a very attractive hypothesis that cell types have evolved by natural selection to lie in the ordered regime , close to the critical phase transition , where the most complex coordinated behaviors can occur [ 7 - 8 ] . in this deterministic setting , it is almost an inevitable hypothesis that the distinct cell types of an organism correspond to the distinct attractors of the network . |
8,020 | Suppose that you have an abstract for a scientific paper: the mid- to far - infrared emission of the outbursting fu orionis objects has been attributed either to a flared outer disk or to an infalling envelope .
we revisit this issue using detailed radiative transfer calculations to model the recent , high signal - to - noise data from the irs instrument on the _ spitzer space telescope_. in the case of fu ori , we find that a physically - plausible flared disk irradiated by the central accretion disk matches the observations . building on our previous work
, our accretion disk model with outer disk irradiation by the inner disk reproduces the spectral energy distribution between @xmath0 4000 to @xmath1 @xmath2 m .
our model is consistent with near - infrared interferometry but there are some inconsistencies with mid - infared interferometric results . including the outer disk allows us to refine our estimate of the outer radius of the outbursting , high mass accretion rate disk in fu ori as @xmath0 0.5 au , which is a crucial parameter in assessing theories of the fu orionis phenomenon .
we are able to place an upper limit on the mass infall rate of any remnant envelope infall rate to @xmath310@xmath4 m@xmath5yr@xmath6 assuming a centrifugal radius of 200 au .
the fuor bbw 76 is also well modelled by a 0.6 au inner disk and a flared outer disk .
however , v1515 cyg requires an envelope with an outflow cavity to adequately reproduce the irs spectrum .
in contrast with the suggestion by green et al . , we do not require a flattened envelope to match the observations ; the inferred cavity shape is qualitatively consistent with typical protostellar envelopes .
this variety of dusty structures suggests that the fu orionis phase can be present at either early or late stages of protostellar evolution . .
And you have already written the first three sentences of the full article: the fu orionis systems are a small but remarkable class of variable young stellar objects ( ysos ) which undergo outbursts in optical light of 5 magnitudes or more @xcite , with a f - g supergiant optical spectra and k - m supergiant near - infrared ( near - ir ) spectra dominated by deep co overtone absorption .
fu orionis objects ( fuors ) have been modelled as a high mass accretion disk around pre - main - sequence stars ( hartmann @xmath7 kenyon 1985 , 1987a , 1987b ) to explain the infrared color excesses and the variations of both the spectral type and rotational line width with wavelength ( hartmann @xmath7 kenyon 1996 ; paper i ) .
@xcite argued that at least some fu orionis outbursts must be repetitive , and @xcite suggested that this could be explained by infall from an envelope to the disk , replenishing the disk mass for further outbursts . the infall picture is also suggested by the presence of scattered light envelopes around fuors , suggesting that they are objects in early stages of star formation @xcite . in the evolution sequence.
Please generate the next two sentences of the article | , fuors may play significant role in transfering a large amount of mass ( @xmath810@xmath9 ) to the central star , which is even higher than the mass accumulated in the t tauri phase @xcite .
however , not all fuors show the large mid - infrared ( mid - ir ) excesses that clearly demand dense infalling envelopes . |
8,021 | Suppose that you have an abstract for a scientific paper: recent theoretical and experimental papers have shown how one can achieve heisenberg limited measurements by using entangled photons . here
we show how the photons in non - collinear down conversion process can be used for improving the sensitivity of magneto - optical rotation by a factor of four which takes us towards the heisenberg limit .
our results apply to sources with arbitrary pumping .
we also present several generalizations of earlier results for the collinear geometry .
the sensitivity depends on whether the two - photon or four - photon coincidence detection is used . .
And you have already written the first three sentences of the full article: parametric down conversion is a process that is used to produce light possessing strong quantum features .
photon pairs generated by this process show entanglement with respect to different physical attributes such as time of arrival @xcite and states of polarization @xcite .
they are increasingly being utilized for very basic experiments to test the foundation of quantum mechanics and to do quantum information processing @xcite ..
Please generate the next two sentences of the article | it is also recognized that entangled photon pairs could be useful in many practical applications in precision metrology involving e.g. interferometry @xcite , imaging @xcite , lithography @xcite and spectroscopy @xcite .
there is a proposal @xcite to use electromagnetic fields in @xmath0 states to improve the sensitivity of measurements by a factor of @xmath1 . |
8,022 | Suppose that you have an abstract for a scientific paper: the recent research has established an analogy between successive interference cancellation in slotted aloha framework and iterative belief - propagation erasure - decoding , which has opened the possibility to enhance random access protocols by utilizing theory and tools of erasure - correcting codes . in this paper
we present a generalization of the and - or tree evaluation , adapted for the asymptotic analysis of the slotted aloha - based random - access protocols , for the case when the contending users experience different channel conditions , resulting in packet loss probability that varies across users .
we apply the analysis to the example of frameless aloha , where users contend on a slot basis .
we present results regarding the optimal access probabilities and contention period lengths , such that the throughput and probability of user resolution are maximized . .
And you have already written the first three sentences of the full article: slotted aloha and its many variants are popular random access mechanisms used in various networks , e.g. , cellular or satellite networks .
the current rise of machine - to - machine ( m2 m ) communications , with substantially increased number of terminals and different traffic patterns with respect to human - centric communications , requires efficient random access mechanisms and their redesign and enhancements are one of the main interests of m2 m research community . an important research track in this direction is use of successive interference cancellation ( sic ) in slotted aloha - based protocols @xcite .
particularly , the work presented in @xcite identified the analogies between sic in framed slotted aloha and the iterative belief - propagation ( bp ) decoding of fixed - rate erasure - correcting codes , enabling the application of erasure - coding theory and tools ..
Please generate the next two sentences of the article | the asymptotic analysis in terms of symbol erasure probability of erasure - correcting codes is standardly performed using and - or tree evaluation technique , first presented in @xcite , and applied in its original form for the slotted aloha case in @xcite . however , both in @xcite , the underlying assumption is that the contending terminals are able to perform perfect power control , and thus experience the uniform probability of packet loss .
these results are not readily transferable to the case when link quality and packet loss vary across terminals . in this paper |
8,023 | Suppose that you have an abstract for a scientific paper: the @xmath0-dependence ( @xmath1- @xmath2 k ) of the electron paramagnetic resonance ( epr ) , magnetic susceptibility , @xmath3 , and specific heat , @xmath4 , of the @xmath5 antiferromagnetic ( afm ) spinel zncr@xmath6o@xmath7 and the spin - glass ( sg ) zn@xmath8cd@xmath9cr@xmath6o@xmath7 ( @xmath10 ) is reported .
these systems behave as a strongly frustrated afm and sg with @xmath11 @xmath12 k and @xmath13 k @xmath14 k. at high-@xmath0 the epr intensity follows the @xmath3 and the @xmath15-value is @xmath0-independent .
the linewidth broadens as the temperature is lowered , suggesting the existence of short range afm correlations in the paramagnetic phase . for zncr@xmath6o@xmath7 the epr intensity and @xmath3 decreases below @xmath16 k and @xmath17 k , respectively .
these results are discussed in terms of nearest - neighbor cr@xmath18 ( s @xmath19 ) spin - coupled pairs with an exchange coupling of @xmath20 @xmath17 k. the appearance of small resonance modes for @xmath21 k , the observation of a sharp drop in @xmath3 and a strong peak in @xmath4 at @xmath22 k confirms , as previously reported , the existence of long range afm correlations in the low-@xmath0 phase .
a comparison with recent neutron diffraction experiments that found a near dispersionless excitation at @xmath23 mev for @xmath24 and a continuous gapless spectrum for @xmath25 , is also given . .
And you have already written the first three sentences of the full article: frustration in the antiferromagnetic ( afm ) ordering of fcc and spinel lattices was recognized long ago by anderson in his analysis of the highly degenerate magnetic ground state of these structures.@xcite this so - called @xmath26 frustration can prevent the system from undergoing spin - glass ( sg ) or afm ordering down to temperatures much lower than the curie - weiss temperature , @xmath27,@xmath28 .
it has also been shown , theoretically @xcite and experimentally , @xcite that the ground state degeneracy can be removed by atomic disorder leading to a sg type of ordering .
the afm @xmath5 spinel zncr@xmath6o@xmath7 structure , in which the octahedral cr sites form corner - sharing tetrahedra , @xcite as well as the pyrochlore @xcite@xmath29@xcite and kagom@xcite structures , are excellent systems to study the _ geometric _ frustration phenomenon ..
Please generate the next two sentences of the article | zncr@xmath6o@xmath7 has a very high curie - weiss temperature , @xmath30 k , and a first order afm transition at @xmath31 @xmath32 k @xcite accompanied by a slight tetragonal crystal distortion ( @xmath33 ) .
@xcite besides , recent interesting low-@xmath0 neutron diffraction experiments showed , in the ordered phase ( @xmath24 ) , the existence of a near dispersionless excitation at @xmath23 mev , and for @xmath34 , a continuous magnetic gapless density of states.@xcite in this work we report on the @xmath0-dependence ( @xmath1 - @xmath2 k ) of the electron paramagnetic resonance ( epr ) , magnetic susceptibility , @xmath3 , and specific heat , @xmath4 , in a single crystal of the @xmath5 spinel zncr@xmath35o@xmath7 of cubic structure ( @xmath36 , o@xmath37 ) and in the cd doped polycrystalline zn@xmath8cd@xmath9cr@xmath6o@xmath7 ( @xmath10 ) compounds . |
8,024 | Suppose that you have an abstract for a scientific paper: we present an analysis of _ xmm - newton _ observations of the superbubble 30 dor c and compare the results with the predictions from the standard wind - blown bubble model .
we find that the observed x - ray spectra can not be fitted satisfactorily with the model alone and that there is evidence for nonthermal x - ray emission , which is particularly important at @xmath0 kev .
the combination of the bubble model and a power - law gives a reasonable fit to the observed spectra .
the thermal pressure and central temperature of the bubble are @xmath1 dyne @xmath2 and @xmath3 k , respectively , and we infer that , for a bubble age of @xmath4 years , the ambient density is @xmath5 @xmath6 , the mechanical luminosity is @xmath7 erg s@xmath8 , and the coefficient of thermal conductivity is @xmath9 of the spitzer value . the total unabsorbed @xmath10@xmath11 kev luminosities of the eastern and western parts of the bubble are @xmath12 erg s@xmath8 and @xmath13 erg s@xmath8 , respectively .
the unabsorbed @xmath10@xmath11 kev luminosity of the bubble model is @xmath14 erg s@xmath8 and so the power - law component contributes between @xmath15 and @xmath16 to the total unabsorbed luminosity in this energy band .
the nature of the hard nonthermal emission is not clear , although recent supernovae in the bubble may be responsible .
we expect that about one or two core - collapse supernovae could have occured and are required to explain the enrichment of the hot gas , as evidenced by the overabundance of @xmath17-elements by a factor of @xmath18 , compared to the mean value of @xmath19 solar for the interstellar medium in the large magellanic cloud . as in previous studies of various superbubbles ,
the amount of energy currently present in 30 dor c is significantly less than the expected energy input from the enclosed massive stars over their lifetime .
we speculate that a substantial fraction of the input energy may be radiated in far - infrared by dust grains , which are mixed with the hot gas....
And you have already written the first three sentences of the full article: the fast winds from massive stars and their subsequent supernovae ( sne ) ejecta dominate the mass and energy input to the interstellar medium ( ism ; e.g. , abbott 1982 ) and so may regulate star formation and galaxy evolution .
most massive stars form in ob associations , and the concentrated energy input from massive stars in ob associations sweeps up the ambient ism to form expanding shells called superbubbles ( e.g. , mccray & snow 1979 ) .
the physical structure of a superbubble is very similar to that of a bubble blown by the stellar wind of an isolated massive star @xcite ..
Please generate the next two sentences of the article | however , theories of such bubbles are still very uncertain and have not had much serious appraisal with observations of high quality .
studies of galactic superbubbles are difficult because of their large angular sizes and the confusion of objects in the line of sight . |
8,025 | Suppose that you have an abstract for a scientific paper: we introduce a concept that uses detuned arm cavities to increase the shot noise limited sensitivity of ligo without increasing the light power inside the arm cavities .
numerical simulations show an increased sensitivity between 125 and 400hz , with a maximal improvement of about 80% around 225hz , while the sensitivity above 400hz is decreased . furthermore our concept is found to give a sensitivity similar to that of a conventional rse configuration with a signal - recycling mirror of moderate reflectivity . in the near future detuned arm cavities
might be a beneficial alternative to rse , due the potentially less hardware intensive implementation of the proposed concept . .
And you have already written the first three sentences of the full article: the first generation of large - scale laser - interferometric gravitational wave detectors @xcite is now in operation and collects data of impressive sensitivity and bandwidth .
the optical configurations of these kilometer long gravitational wave observatories are based on a michelson interferometer
. moreover , the standard configuration , implemented in the three ligo interferometers as well as in virgo and tama300 , employs cavities in the arms of the interferometer and power - recycling to increase the storage time of the light inside the interferometer . in order to get an optimal power increase inside the arm cavities ,.
Please generate the next two sentences of the article | these are kept to be resonant for the carrier light .
however , as we show in this article , detuning these arm cavities by a few hundred hz has the advantage of a larger signal gain in a certain frequency band and might therefore be favorable . |
8,026 | Suppose that you have an abstract for a scientific paper: we simplify the formalism of polder and van hove [ phys.rev.b * 4 * , 3303(1971 ) ] , which was developed to calculate the heat transfer between macroscopic and nanoscale bodies of arbitrary shape , dispersive and adsorptive dielectric properties . in the non - retarded limit , at small distances between the bodies ,
the problem is reduced to the solution of an electrostatic problem .
we apply the formalism to the study of the heat transfer between : ( a ) two parallel semi - infinite bodies , ( b ) a semi - infinite body and a spherical body , and ( c ) that two spherical bodies .
we consider the dependence of the heat transfer on the temperature @xmath0 , the shape and the separation @xmath1 .
we determine when retardation effects become important . .
And you have already written the first three sentences of the full article: it is well known that for bodies separated by @xmath2 the radiative heat transfer between them is described by the stefan- bolzman law : @xmath3 where @xmath4 and @xmath5 are the temperatures of solid @xmath6 and @xmath7 , respectively . in this limiting case the heat transfer is connected with traveling electromagnetic waves radiated by the bodies , and does not depend on the separation @xmath1 .
for @xmath8 the heat transfer increases by many order of magnitude , which can be explained by the existence of evanescent electromagnetic field that decay exponentially into the vacuum . at present time
there is an increasing number of investigations of heat transfer due to evanescent waves in connection with scanning tunneling microscopy and scanning thermal microscopy ( stm ) under ultrahigh vacuum conditions @xcite ..
Please generate the next two sentences of the article | stm can be used for local heating of the surface , resulting in local desorption or decomposition of molecular species , and this offer further possibilities for the stm to control local chemistry on a surface .
a general formalism for evaluating the heat transfer between macroscopic bodies was proposed some years ago by polder and van hove @xcite . |
8,027 | Suppose that you have an abstract for a scientific paper: in this paper we introduce the notion of _ approximate data structures _ , in which a small amount of error is tolerated in the output .
approximate data structures trade error of approximation for faster operation , leading to theoretical and practical speedups for a wide variety of algorithms .
we give approximate variants of the van emde boas data structure , which support the same dynamic operations as the standard van emde boas data structure @xcite , except that answers to queries are approximate .
the variants support all operations in constant time provided the error of approximation is @xmath0 , and in @xmath1 time provided the error is @xmath2 , for @xmath3 elements in the data structure .
we consider the tolerance of prototypical algorithms to approximate data structures .
we study in particular prim s minimum spanning tree algorithm , dijkstra s single - source shortest paths algorithm , and an on - line variant of graham s convex hull algorithm .
to obtain output which approximates the desired output with the error of approximation tending to zero , prim s algorithm requires only linear time , dijkstra s algorithm requires @xmath4 time , and the on - line variant of graham s algorithm requires constant amortized time per operation . .
And you have already written the first three sentences of the full article: the van emde boas data structure ( veb ) @xcite represents an ordered multiset of integers .
the data structure supports query operations for the current minimum and maximum element , the predecessor and successor of a given element , and the element closest to a given number , as well as the operations of insertion and deletion .
each operation requires @xmath5 time , where the elements are taken from a universe @xmath6 ..
Please generate the next two sentences of the article | we give variants of the veb data structure that are faster than the original veb , but only guarantee approximately correct answers .
the notion of approximation is the following : the operations are guaranteed to be consistent with the behavior of the corresponding exact data structure that operates on the elements after they are mapped by a fixed function @xmath7 . for the multiplicatively approximate variant , the function @xmath7 preserves the order of any two elements differing by at least a factor of some @xmath8 . for the additively approximate variant , the function @xmath7 preserves the order of any two elements differing additively by at least some @xmath9 . |
8,028 | Suppose that you have an abstract for a scientific paper: we propose a method to associate a differentiable riemannian manifold to a generic many degrees of freedom discrete system which is not described by a hamiltonian function .
then , in analogy with classical statistical mechanics , we introduce an entropy as the logarithm of the volume of the manifold .
the geometric entropy so defined is able to detect a paradigmatic phase transition occurring in random graphs theory : the appearance of the ` giant component ' according to the erds - rnyi theorem .
* keywords : * probability theory , riemannian geometry , complex systems .
And you have already written the first three sentences of the full article: thermodynamic phase transitions are examples of emergent phenomena in many degrees of freedom systems , described in the framework of statistical mechanics .
the standard statistical ensembles measures relate macroscopic ( thermodynamic ) observables with microscopic degrees of freedom .
the interactions among the microscopic degrees of freedom - which can be either continuous or discrete ( as in the case of spin models , vertex models , and so on ) - are often described by a hamiltonian function ( or a hamiltonian operator in a quantum context ) @xcite ..
Please generate the next two sentences of the article | but what about discrete systems , i.e. networks , undergoing a phase transition for which a microscopic hamiltonian does not exist ? a paradigmatic example
is represented by a random graphs model @xmath0 devised by choosing with uniform probability a graph from the set of all graphs having @xmath1 vertices and @xmath2 edges @xcite . |
8,029 | Suppose that you have an abstract for a scientific paper: the flow of charm is calculated in 2 + 1 ideal hydrodynamics by introducing the charge of @xmath0 pair assuming that the number of @xmath0 pairs is conserved in relativistic heavy - ion collisions .
it is found that the mean radial flow velocity of charm quarks is smaller than that of bulk matter by 10@xmath115 % and the measured @xmath2 of heavy - flavor electrons is reproduced up to @xmath3 1.5 gev / c in au+au collision at rhic .
the same flow is applied to regenerated @xmath4 and its @xmath2 is discussed . .
And you have already written the first three sentences of the full article: heavy flavor is one of the important probes for the hot dense nuclear matter created in relativistic heavy - ion collisions @xcite . unlike the light flavors , heavy flavor was expected to be much less thermalized in the matter due to the relatively smaller cross section .
however , it was found that @xmath5 of heavy flavor is much suppressed in the intermediate and high transverse momentum region and that its @xmath2 is not small @xcite .
this implies that charm quarks , which comprise the majority of heavy flavors produced in heavy - ion collisions , are considerably thermalized . on the other hand ,.
Please generate the next two sentences of the article | charm quarks never reach chemical equilibrium due to too small cross section for the annihilation or the creation of the @xmath0 pair .
in fact , the measured number of @xmath0 pairs in au+au collision at rhic is almost proportional to the number of binary collisions @xcite . |
8,030 | Suppose that you have an abstract for a scientific paper: sco x-2 ( gx 349 + 2 ) is a low - mass x - ray binary and z source .
we have analysed @xmath0156 ks of _ rossi x - ray timing explorer _ data , obtained in 1998 january , on this source .
we investigated the fast - time variability as a function of position on the z track . during these observations ,
sco x-2 traced out the most extensive z track ever reported from this object , making this the most comprehensive study thus far .
we found the broad peaked flaring branch noise that is typical of sco x-2 , with a centroid frequency in the range 3.35.8 hz .
we also discovered low frequency noise , and a new peaked noise feature , with centroid frequencies in the range 5.47.6 hz and 1154 hz , respectively .
we discuss the phenomenology of these features , their relationship with the power spectral components found in other low - mass x - ray binaries , and the implications for current models .
in particular , the low frequency noise we observed was strongest at intermediate energies , in contrast to the low frequency noise seen in other z sources .
we also detected very low frequency noise , and have calculated complex cross spectra between intensity and hardness .
we found that the very low frequency noise is not entirely due to motion along the z track .
[ firstpage ] accretion , accretion disks stars : binaries : close stars : individual : sco x-2 ; gx 349 + 2 stars : neutron x - rays : stars .
And you have already written the first three sentences of the full article: sco x-2 is one of the persistently bright neutron star low - mass x - ray binaries known as z sources .
z sources are so - named because , over time , they trace out a ` z ' shaped track in an x - ray colour - colour ( cd ) and hardness - intensity ( hid ) diagram . the top of the ` z ' is called the horizontal branch ( hb ) , the diagonal is the normal branch ( nb ) , and the bottom is the flaring branch ( fb ) ( hasinger & van der klis @xcite ) . inferred mass - accretion rate increases from the hb , through the nb , to the fb .
the mass - accretion rate is thought to reach the eddington limit at the bottom of the nb , and is super - eddington in the fb ..
Please generate the next two sentences of the article | the five other traditional z sources are : sco x-1 , gx 17 + 2 , cyg x-2 , gx 340 + 0 and gx 5@xmath11 .
a related class of objects are the atoll sources ; they exhibit a curved track in a colour - colour diagram ( hasinger & van der klis @xcite ) . through the study of the x - ray fast - time variability of low - mass x - ray binaries , |
8,031 | Suppose that you have an abstract for a scientific paper: we report x - ray total scattering and pair distribution function ( pdf ) studies of the structural relaxation around interstitial manganese ( mn@xmath0 ) in ferromagnetic mn@xmath1sb ( @xmath2 ) alloys , guided by density functional theory ( dft ) .
refinements to the experimental pdf using a crystallographically constrained structural model indicate an expansion in the equatorial plane of the mn@xmath0sb@xmath3 trigonal bipyramidal site , which introduces significant positional disorder in addition to the nominally - random occupation of interstitial voids .
observation of a weak diffuse signal near the symmetry - forbidden ( 001 ) reflection position is indicative of correlated disorder from the clustering of mn@xmath0 .
density functional relaxation of supercells approximating the @xmath4 , @xmath5 and @xmath6 compositions provides improved models that accurately describe the short - range structural distortions captured in the pdfs .
such structural relaxation increases the dft calculated moment on mn@xmath0 , which aligns antiparallel to the primary mn moments , but leads to insubstantial changes in the average mn and sb moments and moments of mn and sb proximal to interstitials , thus providing a more accurate description of the observed bulk magnetic properties . .
And you have already written the first three sentences of the full article: manganese pnictides of the hexagonal nias structure type ( _ e.g. _ mnas , mn@xmath1sb , mnbi ; figure [ fig : structure ] ) display a wealth of functional magnetic properties .
the class of materials includes potential candidates for rare earth - free permanent magnets,@xcite magneto - optical data storage,@xcite and magnetic refrigeration.@xcite manganese antimonide is known to only exist as a manganese - rich phase , mn@xmath1sb.@xcite the wide compositional region shown on the equilibrium phase diagram extends from @xmath7,@xcite with excess mn occupying the interstitial site ( figure [ fig : structure]b ) in trigonal bipyramidal coordination by sb .
increasing amounts of interstitial mn ( mn@xmath0 ) lengthen the @xmath8 and shorten the @xmath9 lattice parameters , which accompanies reductions of the saturation magnetization , spin - reorientation temperature ( @xmath10),@xcite and the curie temperature ( @xmath11).@xcite magnetic ordering of the primary mn sites occurs parallel to @xmath9 at high temperature , but it changes to the @xmath12 plane below @xmath10.@xcite although the bulk magnetic properties are well known , the microscopic nature of the magnetism associated with mn@xmath0 has been equivocal ..
Please generate the next two sentences of the article | a straightforward explanation of the reduced magnetization in more mn - rich samples is that mn@xmath0 is aligned antiparallel to the ferromagnetic mn@xmath13 atoms , that is , mn@xmath1sb is ferrimagnetic .
( here we use krger vink notation to differentiate interstitial mn@xmath0 and nominal mn@xmath13 atoms . ) |
8,032 | Suppose that you have an abstract for a scientific paper: resummation , ie .
reorganization of perturbative series , can result in an inconsistent perturbation theory , unless the counterterms are reorganized in an appropriate way . in this paper
two methods are presented for resummation of counterterms : one is a direct method where the necessary counterterms are constructed order by order ; the other is a general one , based on renormalization group arguments .
we demonstrate at one hand that , in mass independent schemes , mass resummation can be performed by gap equations renormalized _ prior to _ the substitution of the resummed mass for its argument .
on the other hand it is shown that any ( momentum - independent ) form of mass and coupling constant resummation is compatible with renormalization , and one can explicitly construct the corresponding counterterms . .
And you have already written the first three sentences of the full article: resummation is often required in a perturbation theory to avoid infrared ( ir ) divergences to appear at finite energy scales .
examples are 1pi diagram resummation ( schwinger - dyson equation ) to cure the on - shell singularity of the propagator , or daisy resummation @xcite to resum ir divergences of massless theories at finite temperature .
we need leading ( or higher order ) logarithmic resummation near a second order phase transition point @xcite , and the htl resummation @xcite to be able to consistently define finite temperature observables in gauge theories ..
Please generate the next two sentences of the article | resummation means reorganization of the perturbative series in a way that the diagrams that are most important from the point of view of ir behavior , are taken into account first .
however , ir importance does not necessarily means uv importance as well , and so it can happen that those ( counterterm ) diagrams that are needed to make the theory finite , are shifted to a later stage in the resummation process . |
8,033 | Suppose that you have an abstract for a scientific paper: intermediate resolution spectroscopy of the white dwarf sdssj104341.53 + 085558.2 contains double - peaked emission lines of caii@xmath08498,8542,8662 and identifies this object to be the second single white dwarf to be surrounded by a gaseous disc of metal - rich material , similar to the recently discovered sdssj1228 + 1040 .
a photospheric magnesium abundance of 0.3 times the solar value , determined from the observed mgii@xmath14481 absorption line , implies that the white dwarf is accreting from the circumstellar material .
the absence of balmer emission lines and of photospheric hei@xmath14471 absorption indicates that the accreted material is depleted in volatile elements and , by analogy with sdss1228 + 1040 , may be the result of the tidal disruption of an asteroid .
additional spectroscopy of the daz white dwarfs wd1337 + 705 and gd362 does not reveal caii emission lines .
gd362 is one of the few cool daz that display strong infrared flux excess , thought to be originating in a circumstellar dust disc , and its temperature is likely too low to sublimate sufficient amounts of disc material to generate detectable caii emission .
wd1337 + 705 is , as sdss1228 + 1040 and sdssj1043 + 0855 , moderately hot , but has the lowest mg abundance of those three stars , suggesting a possible correlation between the photospheric mg abundance and the equivalent width of the emission triplet .
our inspection of 7360 white dwarfs from sdss dr4 fails to unveil additional strong `` metal gas disc '' candidates , and implies that these objects are rather rare .
[ firstpage ] stars : individual : sdssj104341.53 + 085558.2 white dwarfs .
And you have already written the first three sentences of the full article: two decades ago , @xcite detected an infrared excess around the da white dwarf g2938 as part of their search for cool companions to white dwarfs . @xcite and @xcite convincingly ruled out the presence of a low - mass stellar companion , and @xcite suggested that the observed infrared excess is caused by a ring of circumstellar dust around the white dwarf , a model further developed by @xcite , and underpinned by spitzer observations @xcite .
another four single white dwarfs with infrared excesses have since then been discovered ( gd362 , @xcite ; gd56 , @xcite ; wd1150 - 153 , @xcite ; wd2115560 , von hippel et al .
2007 ) , plus one additional candidate ( g1678 , @xcite ) ..
Please generate the next two sentences of the article | two common characteristic of all those white dwarfs with circumstellar dust discs are their low temperatures , @xmath2k , and their substantial abundances of photospheric calcium @xcite .
no evidence for the presence of dusty discs has been found around white dwarfs hotter than @xmath3k @xcite . |
8,034 | Suppose that you have an abstract for a scientific paper: the time evolution of a charged spin @xmath0 particle interacting with a magnetic field is analyzed in the framework of the complex spectral theory , based on prigogine s principles that provide a rigorous description of irreversibility .
a detailed survey of the irreversible relaxation process of the spin @xmath0 particle is carried out on the basis of the subdynamics theory .
we obtain the results for the markovian and the non - markovian evolution of the charged particle .
irreversibility , subdynamics , kinetic , non - markovian .
And you have already written the first three sentences of the full article: our experience suggests that the symmetry in the time is disrupted and the future and the past play different roles .
the world surrounding us has obvious irreversible nature .
however , poincare showed that @xcite the description of the irreversibility is impossible on the basis of the classical laws of dynamics , since the latter are reversible in time ..
Please generate the next two sentences of the article | the equations of quantum mechanics are reversible too .
the description of the physical world on the basis of fundamental classical and quantum theories as defined by the laws of the nature is determined to be time reversible . |
8,035 | Suppose that you have an abstract for a scientific paper: in this letter we point out the possibility to study new physics in the neutrino sector using dark matter detectors based on liquid xenon .
these are characterized by very good spatial resolution and extremely low thresholds for electron recoil energies . when combined with a radioactive @xmath0 source , both features in combination allow for a very competitive sensitivity to neutrino magnetic moments and sterile neutrino oscillations .
we find that , for realistic values of detector size and source strength , the bound on the neutrino magnetic moment can be improved by an order of magnitude with respect to the present value .
regarding sterile neutrino searches , we find that most of the gallium anomaly could be explored at the 95% confidence level just using shape information . .
And you have already written the first three sentences of the full article: neutrinos have long been a rich hunting ground for physics beyond the standard model ( bsm ) .
in fact , neutrino mass is so far the only bsm physics that has been established in laboratory experiments .
astrophysical evidence of dark matter suggests the existence of bsm particles , which have nevertheless not been observed yet . among all feasible candidates , weakly interacting massive particles ( wimps ) are theoretically rather appealing ..
Please generate the next two sentences of the article | these may be observable through their interactions within detectors , as the earth moves through the sea of wimps .
this possibility has triggered a cornucopia of experimental efforts of direct dark matter detection @xcite . in this letter |
8,036 | Suppose that you have an abstract for a scientific paper: two - neutron correlation in the @xmath0 channel in quasi two - dimensional ( 2d ) neutron systems at zero temperature is studied by means of the bcs theory with finite - range effective nuclear forces .
the dineutron correlation in low density neutron systems confined in an infinite slab is investigated in a simplified model that neutron motion of one direction is frozen . when the slab is thin enough , two neutrons form a tightly bound dineutron with a small size in the quasi-2d system , and a bose dineutron gas is found in low density limit .
with increase of fermi momentum , the neutron system changes from the bose - gas phase to the superfluid cooper pair phase .
the density dependence of the neutron pairing shows the bcs - bec crossover phenomena at finite low - density region . in the transition region , the size shrinking of neutron pair and enhancement of pairing gap are found .
the relation to dineutron correlation at surface of neutron - rich nuclei is also discussed . .
And you have already written the first three sentences of the full article: two - neutron correlations in neutron - rich nuclei is presently one of the fore - front subjects in the physics of unstable nuclei . in two - neutron halo nuclei @xcite such as @xmath1li , the dineutron correlation
was theoretically predicted in many studies @xcite and is supported by experiments @xcite .
dineutron correlations are discussed also in light neutron - rich nuclei such as in @xmath2he @xcite and also in medium - heavy neutron - rich nuclei @xcite as well as asymmetric nuclear matter ( for example , refs ..
Please generate the next two sentences of the article | @xcite and references therein ) .
dineutron correlations are characterized by strong spatial correlations of two neutrons in the @xmath0 channel . |
8,037 | Suppose that you have an abstract for a scientific paper: in this note we improve our upper bound given in @xcite by showing that every @xmath0-fold covering of a point set in @xmath1 by finitely many translates of an octant decomposes into two coverings , and our lower bound by a construction for a @xmath2-fold covering that does not decompose into two coverings .
the same bounds also hold for coverings of points in @xmath3 by finitely many homothets or translates of a triangle .
we also prove that certain dynamic interval coloring problems are equivalent to the above question . .
And you have already written the first three sentences of the full article: by an _ octant _ , in this paper we mean an open subset of @xmath1 of the form @xmath4 and the point @xmath5 is called the _ apex _ of the octant . in @xcite
we have shown that every @xmath6-fold covering of a set in @xmath1 by a finite number of octants decomposes into two coverings , i.e. , if every point of some set @xmath7 is contained in at least @xmath6 members of a finite family of octants @xmath8 , then we can partition this family into two subfamilies , @xmath9 , such that every point of @xmath7 is contained in an octant from @xmath10 and in an octant from @xmath11 .
we improve this constant in the following theorem , proved in section [ sec : upper ] ..
Please generate the next two sentences of the article | [ thm:9 ] every @xmath0-fold covering of a point set in @xmath1 by finitely many octants decomposes into two coverings .
the improvement comes from a careful modification of our original proof for @xmath6-fold covering , while the framework remains essentially the same . |
8,038 | Suppose that you have an abstract for a scientific paper: we present a short overview of the formation and evolution of ultra - compact binaries .
they are relevant to a surprisingly large number of astrophysical phenomena ( binary interactions , mass transfer stability , explosive phenomena such as type ia supernovae and gravitational waves ) . .
And you have already written the first three sentences of the full article: ultra - compact binaries refer to double stars with orbital periods typically less than about one hour .
they come in two general flavours : detached systems and interacting binaries in which mass is transferred from one star to the other .
the limit of about one hour is derived from a very simple argument , dating back to ( * ? ? ?.
Please generate the next two sentences of the article | * see also @xcite ) .
each component in a binary has a radius at most the size of its roche lobe , which for a star of mass @xmath0 and radius @xmath1 with a companion of mass @xmath2 can be approximated as @xmath3 @xcite . when combined with kepler s third law to eliminate @xmath4 ( and @xmath2 ! ) using the orbital period @xmath5 this yields @xmath6 . |
8,039 | Suppose that you have an abstract for a scientific paper: we study theoretically the optical properties of quantum tubes , one - dimensional semiconductor nanostructures where electrons and holes are confined to a cylindrical shell . in these structures , which bridge between 2d and 1d systems ,
the electron - hole interaction may be modulated by a dielectric substance outside the quantum tube and possibly inside its core .
we use the exact green s function for the appropriate dielectric configuration and exact diagonalization of the electron - hole interaction within an effective mass description to predict the evolution of the exciton binding energy and oscillator strength .
contrary to the homogeneous case , in dielectrically modulated tubes the exciton binding is a function of the tube diameter and can be tuned to a large extent by structure design and proper choice of the dielectric media . .
And you have already written the first three sentences of the full article: cylindrical semiconductor nanostructures bridge between quasi-1d systems at small diameters and quasi-2d in the opposite limit , thus extending the wealth of physics and applications of low - dimensional solid - state systems .
the controlled growth of semiconductor quantum tubes ( qts ) with diameters in the 10 - 100 nm range has been recently demonstrated through several techniques , including multi - layer overgrowth of nanowires@xcite and strain - induced bending of a planar heterostructure.@xcite in addition to qts with a solid semiconductor core , it is possible to grow _ hollow _ qts , where the charge carriers are confined in a thin semiconductor shell , encompassed by a barrier material which is only a few nm thick.@xcite large surface - to - volume ratios and the possibility of various functionalizations on both the internal and external surfaces make the latter systems particularly interesting for applications.@xcite although experiments concerning the optical properties of these systems are still limited , advancements in the optical quality of the samples point to a rapid increase of these investigations.@xcite the excitonic properties of semiconductor qts are particularly interesting with respect to conventional semiconductor quantum wires , where excitons are confined in the core of the nanostructure.@xcite on the one hand , due to the combined effect of the qt curvature and of the quasi-2d confinement of carriers in the cylindrical shell , excitonic binding energies might be substantially stronger than in bulk , even for large diameter qts . on the other hand , a dielectric medium outside the shell of the qt may result in a dielectric confinement of the electric field felt by the optically excited electron - hole pairs , in most cases enhancing their excitonic binding energy . since the dielectric interface is spatially separated from the carriers , which are confined deep inside the shell , excitonic binding and sensitivity to the medium might be strongly enhanced without spoiling the....
Please generate the next two sentences of the article | present work on qts theoretically considered magnetic states,@xcite reported experimental evidence of the aharonov
bohm effect,@xcite and treated optical properties,@xcite but the influence of the dielectric dismatch between the nanostructure and the environment has been studied so far only for conventional quantum wires@xcite and freestanding nanowires.@xcite here we will consider also a dielectric mismatch between the core and the shell , which will lead to a considerable change in the electron - hole interaction , as shown in fig . [ |
8,040 | Suppose that you have an abstract for a scientific paper: we present the first interferometric polarization maps of the ngc2024 fir5 molecular core obtained with the bima array at approximately 2 resolution .
we measure an average position angle of @xmath0606 in the main core of fir5 and 549 in the eastern wing of fir5 .
the morphology of the polarization angles in the main core of fir5 suggests that the field lines are parabolic with a symmetry axis approximately parallel to the major axis of the putative disk in fir5 , which is consistent with the theoretical scenario that the gravitational collapse pulled the field lines into an hour - glass shape .
the polarization percentage decreases toward regions with high intensity and close to the center of the core , suggesting that the dust alignment efficiency may decrease at high density .
the plane - of - sky field strength can be estimated with the modified chandrasekhar - fermi formula , and the small dispersion of the polarization angles in fir5 suggests that the magnetic field is strong ( @xmath1 mg ) and perhaps dominates the turbulent motions in the core . .
And you have already written the first three sentences of the full article: magnetic fields are thought to play a significant role in all stages of star formation ( e.g. , recent reviews by mouschovias & ciolek 1999 ; shu et al .
1999 ) . however , the magnetic field is the most poorly measured quantity in the star formation process .
observations of the linear polarization from the thermal emission of magnetically aligned dust grains provide a relatively easy approach to explore the magnetic field morphology ( heiles et al ..
Please generate the next two sentences of the article | such observations give the field direction in the plane of the sky perpendicular to the direction of polarization ( davis & greenstein 1951 ; roberge 1996 ) .
information on the magnetic field morphology is useful for testing the predictions of theoretical models and simulations . |
8,041 | Suppose that you have an abstract for a scientific paper: we have determined the magnetic structure of the noncentrosymmetric heavy - fermion superconductor cept@xmath0si using elastic polarized neutron scattering with field - projected ( longitudinal ) xyz polarization analysis .
we find that the magnetic moment has components both in the tetragonal basal plane and along the tetragonal four - fold axis .
such a magnetic structure is not symmetry - allowed if the magnetic phase transition is second order , and may imply that cept@xmath0si has lower symmetry in the superconducting state than originally thought .
the tetragonal heavy - fermion compound cept@xmath0si has received strong attention in recent years because it shows unconventional superconductivity despite its noncentrosymmetric crystal structure @xcite .
this lack of inversion symmetry leads to an antisymmetric spin - orbit coupling of rashba type , which mixes spin - singlet and spin - triplet cooper - pairing channels @xcite .
the superconducting transition occurs at @xmath1 k , well inside the magnetically ordered state that sets in at @xmath2 k. this suggests that magnetism may play an important role in the pairing mechanism , further highlighted by the fact that the cooper pairs are formed by heavy quasiparticles @xcite .
the magnetic excitations in cept@xmath0si are well understood .
the @xmath3 multiplet of the @xmath4 ce@xmath5 ion is split by the tetragonal point symmetry into three doublets .
the doublet ground state is @xmath6 , as shown by a study combining polarized inelastic neutron scattering with soft x - ray absorption spectroscopy @xcite .
the main exchange interactions have been determined from the dispersion of the somewhat damped spin - wave excitations in the magnetically ordered phase by unpolarized inelastic neutron scattering ( ins ) @xcite . above @xmath7 ,
kondo - type spin fluctuations with an anisotropic wave - vector dependence are observed by ins @xcite . as a consequence of the antisymmetric spin - orbit coupling ,
the spin susceptibility is....
And you have already written the first three sentences of the full article: 10 bauer e , hilscher g , michor h , paul ch , scheidt e w , gribanov a , seropegin yu , nol h , sigrist m and rogl p 2004 heavy fermion superconductivity and magnetic order in noncentrosymmetric cept@xmath0si _ phys .
lett . _ * 92 * 027003 bauer e , kaldarar h , prokofiev a , royanian e , amato a , sereni j , brmer - escamilla w and bonalde i 2007 heavy fermion superconductivity and antiferromagnetic ordering in cept@xmath0si without inversion symmetry _ j. phys
jpn . _ * 76 * 051009 willers t , fk b , hollmann n , krner p o , hu z , tanaka a , schmitz d , enderle m , lapertot g , tjeng l h and severing a 2009 crystal - field ground state of the non - centrosymmetric superconductor cept@xmath0si : a combined polarized soft x - ray absorption and polarized neutron study _ phys . rev ..
Please generate the next two sentences of the article | _ b * 80 * 115106 fk b , raymond s , braithwaite d , lapertot g and mignot j - m 2008 low - energy magnetic response of the noncentrosymmetric heavy - fermion superconductor cept@xmath0si studied via inelastic neutron scattering _ phys .
b * 78 * 184518 inosov d s , bourges p , ivanov a , prokofiev a , bauer e and keimer b 2011 dispersion and damping of zone - boundary magnons in the noncentrosymmetric superconductor cept@xmath0si _ j. phys . : |
8,042 | Suppose that you have an abstract for a scientific paper: david findley was born in washington , dc on december 27 , 1940 . after attending high school in lyndon , kentucky , he earned a b.s .
( 1962 ) and m.a .
( 1963 ) in mathematics from the university of cincinnati .
he then lived in germany , studying functional analysis under gottfried kthe , obtaining a ph.d . from the university of frankfurt in 1967 .
returning to the united states , he served as a mathematics professor at the university of cincinnati until 1975 . having transitioned from pure mathematics to statistical time series analysis , findley took a new academic position at the university of tulsa , during which time he interacted frequently with the nearby research laboratories of major oil companies and consulted regularly for cities service oil company ( now citgo ) . in 1980
he was invited to lead the seasonal adjustment research effort at the u.s .
census bureau , and eventually rose to be a senior mathematical statistician before his retirement in 2009 . in 1966
he married mary virginia baker , and they currently live in washington , dc .
david findley has published more than 40 journal articles and book chapters , as well as dozens of technical reports and conference proceedings , many of which are heavily cited and influential .
he has also published two edited volumes ( 1978 and 1981 ) that have had a substantial impact on the field of time series analysis .
numerous honors and awards have accrued to him , including asa fellow ( 1987 ) , the julius shiskin award ( 1996 ) and the u.s .
department of commerce gold medal ( 1997 ) .
. the initial conversation between david findley , scott holan and tucker mcelroy took place on july 13 , 2010 at the u.s . census bureau .
holan and mcelroy later obtained clarifications of certain points from david findley during the following year . .
And you have already written the first three sentences of the full article: * mcelroy * : hello , david .
we are thankful to have the opportunity to discuss your life and career .
could you describe for us the early influences that led you to pursue a career in mathematics ? * findley * : in high school i found algebra and geometry enjoyable and interesting ..
Please generate the next two sentences of the article | i found out decades later that many of my relatives were mathematics teachers , including one who taught in suitland high school , not far from the u.s .
census bureau ( uscb ) . |
8,043 | Suppose that you have an abstract for a scientific paper: the first long - baseline alma campaign resolved the disk around the young star hl tau into a number of axisymmetric bright and dark rings . despite the very young age of hl tau these structures
have been interpreted as signatures for the presence of ( proto)planets .
the alma images triggered numerous theoretical studies based on disk - planet interactions , magnetically driven disk structures , and grain evolution .
of special interest are the inner parts of disks , where terrestrial planets are expected to form .
however , the emission from these regions in hl tau turned out to be optically thick at all alma wavelengths , preventing the derivation of surface density profiles and grain size distributions . here
, we present the most sensitive images of hl tau obtained to date with the karl g. jansky very large array at 7.0 mm wavelength with a spatial resolution comparable to the alma images . at this long wavelength
the dust emission from hl tau is optically thin , allowing a comprehensive study of the inner disk .
we obtain a total disk dust mass of ( 1 - 3)@xmath010@xmath1 m@xmath2 , depending on the assumed opacity and disk temperature .
our optically thin data also indicate fast grain growth , fragmentation , and formation of dense clumps in the inner densest parts of the disk .
our results suggest that the hl tau disk may be actually in a very early stage of planetary formation , with planets not already formed in the gaps but in the process of future formation in the bright rings . .
And you have already written the first three sentences of the full article: hl tau is a very young solar - type star surrounded by a dusty circumstellar disk and a remnant envelope .
the object is located at a distance of @xmath3140 pc ( loinard et al . 2007 ) , within the taurus star - forming region . showing all ingredients of a young system in the earliest stages of planet formation ,
hl tau has attracted a lot of attention over the years . for a summary of the early observational data and the results of the first comprehensive radiative transfer modeling we refer to dalessio et al ..
Please generate the next two sentences of the article | ( 1997 ) and menshchikov , henning & fischer ( 1999 ) .
hl tau drives an ionized jet indicating on - going accretion ( e.g. , pyo et al . |
8,044 | Suppose that you have an abstract for a scientific paper: it is well established that the phase transition between survival and extinction in spreading models with short - range interactions is generically associated with the directed percolation ( dp ) universality class . in many realistic spreading processes , however , interactions are long ranged and well described by lvy - flights , i.e. , by a probability distribution that decays in @xmath0 dimensions with distance @xmath1 as @xmath2 .
we employ the powerful methods of renormalized field theory to study dp with such long range , lvy - flight spreading in some depth .
our results unambiguously corroborate earlier findings that there are four renormalization group fixed points corresponding to , respectively , short - range gaussian , lvy gaussian , short - range dp and lvy dp , and that there are four lines in the @xmath3 plane which separate the stability regions of these fixed points .
when the stability line between short - range dp and lvy dp is crossed , all critical exponents change continuously .
we calculate the exponents describing lvy dp to second order in @xmath4-expansion , and we compare our analytical results to the results of existing numerical simulations .
furthermore , we calculate the leading logarithmic corrections for several dynamical observables . .
And you have already written the first three sentences of the full article: the formation and the properties of random structures have been an exciting topic in statistical physics for many years . in the case
that the formation of such structures obeys local rules , these processes can often be expressed in the language of epidemic spreading .
it is well - known that two special spreading processes referred to in this language respectively as simple epidemic with recovery or gribov process @xcite and epidemic with removal ( general epidemic process ) lead to random structures with the properties of percolation clusters : directed percolation @xcite in the former case and isotropic percolation in the latter ..
Please generate the next two sentences of the article | the gribov process , also known in elementary particle physics as reggeon field theory ( rft ) @xcite , is a stochastic multiparticle process that describes the essential features of a vast number of growth phenomena of populations without exploitation of the environment near their extinction threshold .
the transition between survival and extinction of the population ( infected individuals ) is a nonequilibrium continuous phase transition phenomenon and is characterized by universal scaling laws . |
8,045 | Suppose that you have an abstract for a scientific paper: we study the dynamics of two - dimensional coherent structures in planetary atmospheres and oceans .
we derive the zakharov - kuznetsov equation for large scale motion from the barotropic quasigeostrophic equation in a weakly nonlinear , long wave approximation .
we consider coherent structures emerging out of an instability caused by a narrow jet - like meanflow .
we use multiple scale analysis combined with asymptotic matching .
pacs numbers : 47.35.+i ; 47.32.-y ; 92.10.-c ; 92.60.-e keywords : solitary waves ; zakharov - kuznetsov equation ; barotropic quasigeostrophic equation .
And you have already written the first three sentences of the full article: planetary atmospheres and oceans are strongly turbulent media . however , highly ordered coherent structures arise in a process of self - organization , and dominate the dynamics on slow temporal and large spatial scales . + the spontaneous appearance of coherent structures is a characteristic of two - dimensional fluid flows .
the basic underlying structure of these flows is linked to the existence of two quadratic , positive definite invariants , energy and enstrophy . in spectra of two - dimensional turbulence one
observes two different cascades associated with these conserved quantities ; a direct enstrophy cascade towards small spatial scales , and an indirect energy cascade towards larger spatial scales ..
Please generate the next two sentences of the article | it is the latter which gives rise to vortex merging leading to larger and larger vortices . in this letter
we view the problem as one of weakly nonlinear hydrodynamic stability rather than turbulence phenomenology . |
8,046 | Suppose that you have an abstract for a scientific paper: the isovector gmo sum rule for zero energy forward @xmath0n scattering is critically studied to obtain the charged @xmath1 coupling constant using the precise @xmath2p and @xmath3d scattering lengths deduced recently from pionic atom experiments .
this direct determination leads to @xmath4 ( statistic ) @xmath5 ( systematic ) or @xmath6 .
we obtain also accurate values for the @xmath0n scattering lengths .
And you have already written the first three sentences of the full article: the analysis to determine the @xmath7nn coupling constant should be clear and easily reproducible .
one should do a detailed study for the statistical and systematic errors .
the precise determination is an absolute statement , it could be erroneous and it should be improvable . in this perspective.
Please generate the next two sentences of the article | the goldberger - miyazawa - oehme ( gmo ) sum rule @xcite might be a good candidate .
it is a forward dispersion relation at zero energy for @xmath7n scattering . |
8,047 | Suppose that you have an abstract for a scientific paper: we perform a coupled - channel analysis of pseudodata for the @xmath0 dalitz plot .
the pseudodata are generated from the isobar model of the e791 collaboration , and are reasonably realistic .
we demonstrate that it is feasible to analyze the high - quality data within a coupled - channel framework that describes the final state interaction of @xmath0 as multiple rescatterings of three pseudoscalar mesons through two - pseudoscalar - meson interactions in accordance with the two - body and three - body unitarity .
the two - pseudoscalar - meson interactions are designed to reproduce empirical @xmath1 and @xmath2 scattering amplitudes .
furthermore , we also include mechanisms that are beyond simple iterations of the two - body interactions , i.e. , a three - meson force , derived from the hidden local symmetry model .
a picture of hadronic dynamics in @xmath0 described by our coupled - channel model is found to be quite different from those of the previous isobar - type analyses .
for example , we find that the @xmath3 decay width can get almost triplicated when the rescattering mechanisms are turned on . among the rescattering mechanisms , those associated with the @xmath4 channel , which contribute to @xmath3 only through a channel coupling ,
give a large contribution , and significantly improve the quality of the fits .
the @xmath5 @xmath6-wave amplitude from our analysis is reasonably consistent with those extracted from the e791 model independent partial - wave analysis ; the hadronic rescattering and the coupling to the @xmath4 channel play a major role here .
we also find that the dressed @xmath7 decay vertices have phases , induced by the strong rescatterings , that strongly depend on the momenta of the final pseudoscalar mesons .
although the conventional isobar - type analyses have assumed the phases to be constant , this common assumption is not supported by our more microscopic viewpoint . .
And you have already written the first three sentences of the full article: with the advent of charm and b - factories , a large amount of data for charmed - meson decays have been accumulated in the last decades . among a number of physical interests , one appealing aspect of studying these charmed - meson decays
is that we can gain information about interactions between light mesons and resonances .
this was particularly highlighted by the e791 collaboration s report on their identification of the @xmath8 meson in the dalitz plot of the @xmath9 decay @xcite ..
Please generate the next two sentences of the article | a similar analysis was also made for the @xmath0 decay to identify the @xmath10 resonance @xcite .
these findings triggered further analyses of the @xmath0 dalitz plot data , paying special attention to the @xmath5 @xmath6-wave amplitude , as follows . |
8,048 | Suppose that you have an abstract for a scientific paper: the distinguishing number @xmath0 of a graph @xmath1 is the least cardinal @xmath2 such that @xmath1 has a labeling with @xmath2 labels which is only preserved by the trivial automorphism .
we show that the distinguishing number of infinite , locally finite , connected graphs @xmath1 with infinite motion and growth @xmath3 is either @xmath4 or @xmath5 , which proves the infinite motion conjecture of tom tucker for this type of graphs .
the same holds true for graphs with countably many ends that do not grow too fast .
we also show that graphs @xmath1 of arbitrary cardinality are @xmath5-distinguishable if every nontrivial automorphism moves at least uncountably many vertices @xmath6 , where @xmath7 .
this extends a result of imrich et al . to graphs with automorphism groups of arbitrary cardinality .
* keywords : * distinguishing number , automorphisms , infinite graphs . *
msc classes : * 05c25 , 05c63 , 05c15 , 03e10 . .
And you have already written the first three sentences of the full article: albertson and collins @xcite introduced the distinguishing number @xmath0 of a graph @xmath1 as the least cardinal @xmath2 such that @xmath1 has a labeling with @xmath2 labels which is only preserved by the trivial automorphism .
this seminal concept spawned many papers on finite and infinite graphs .
we are mainly interested in infinite , locally finite , connected graphs of polynomial growth , see @xcite , @xcite , @xcite , and in graphs of higher cardinality , see @xcite , @xcite . in particular , there is one conjecture on which we focus our attention , the infinite motion conjecture of tom tucker . before stating it , we introduce the notation @xmath8 for the number of elements moved by an automorphism @xmath9 , and call @xmath8 the _ motion _ of @xmath9 ..
Please generate the next two sentences of the article | in other words , @xmath8 is the size of the set of vertices which are not fixed by @xmath9 , that is , the size of its _ support _ , @xmath10 . * the infinite motion conjecture of tom tucker . * _ let @xmath1 be an infinite , locally finite , connected graph .
if every nontrivial automorphism of @xmath1 has infinite motion , then the distinguishing number @xmath0 of @xmath1 is either 1 or 2 . |
8,049 | Suppose that you have an abstract for a scientific paper: the trigonometric kz equations associated to a lie algebra @xmath0 depend on a parameter @xmath1 where @xmath2 is a cartan subalgebra .
a system of dynamical difference equations with respect to @xmath3 compatible with the kz equations is introduced in @xcite .
we prove that the standard hypergeometric solutions of the trigonometric kz equations associated to @xmath4 also satisfy the dynamical difference equations . _
@xmath5 department of mathematics , university of north carolina , chapel hill , + nc 27599 3250 , usa + \{yavmar , anv } @ email.unc.edu_ + * mathematics subject classification : * primary : 35q40 ; secondary 17b10 + * key words : * hypergeometric solutions , dynamical equations , kz equations .
And you have already written the first three sentences of the full article: consider the simplest of hypergeometric integrals , @xmath6 it satisfies the differential equation @xmath7 the difference equation @xmath8 and a similar difference equation with respect to @xmath9 .
the equations ( [ simplekz ] ) and ( [ simpledyn ] ) are clearly compatible .
more general hypergeometric integrals appear in conformal field theory as integral representations for conformal blocks , see @xcite ..
Please generate the next two sentences of the article | it is known that the integrals satisfy the kz differential equations .
the kz equations are generalizations of ( [ simplekz ] ) . in @xcite a system of difference equations , generalizing equation ( [ simpledyn ] ) , |
8,050 | Suppose that you have an abstract for a scientific paper: we present a detailed experimental procedure for preparing relativistic vortices , governed by the nonlinear dirac equation , in a two - dimensional bose - einstein condensate ( bec ) in a honeycomb optical lattice .
our setup contains dirac points , in direct analogy to graphene .
we determine a range of practical values for all relevant physical parameters needed to realize relativistic vortices in bec of @xmath0 atoms .
seven distinct vortex types , including anderson - toulouse and mermin - ho skyrmion textures and half - quantum vortices , are obtained , and their discrete spectra and stability properties are calculated in a weak harmonic trap .
we find that most vortices are stable with a lifetime between @xmath1 and @xmath2 seconds .
multi - component bose - einstein condensates ( becs ) present an ideal setting for studying complex vortex structures @xcite .
such vortices allow for topologically intriguing configurations ranging from skyrmions to knots @xcite .
the usual method for adding a spinor structure to a bec relies on hyperfine degrees of freedom or different atomic species .
instead , we use the band structure and linear dispersion relation around the dirac points at the brillouin zone edge of a honeycomb optical lattice to realize a four - component dirac spinor , in direct analogy to graphene @xcite .
this gives us both pseudospin as well as a relativistic structure . to accomplish this
, we propose starting with a bec of weakly interacting alkali metal atoms in the lowest bloch state of a 2d honeycomb optical lattice , then using bragg scattering to populate bloch states at the two inequivalent dirac points , followed by the application of a laguerre - gaussian laser beam to deliver a net angular momentum to the bec which excites a plethora of vortex structures .
the vortices we obtain are solutions of the nonlinear dirac equation ( nlde ) , whose stability is determined by the relativistic linear stability equations ( rlse ) @xcite .
our work on the....
And you have already written the first three sentences of the full article: this material is based in part upon work supported by the national science foundation under grant numbers phy-1067973 , phy-1011156 , and the air force office of scientific research grant number fa9550 - 08 - 1 - 0069 .
thanks the alexander von humboldt foundation and the heidelberg center for quantum dynamics for additional support .
kawaguchi , y. & ueda , m. _ phys ..
Please generate the next two sentences of the article | a _ * 84 , * 053616 ( 2011 ) .
leanhardt , a. e. , shin , y. , kielpinski , d. , pritchard , d. e. & ketterle , w. _ phys . |
8,051 | Suppose that you have an abstract for a scientific paper: using the new supercomputer jump at the research center jlich , we were able to simulate large lattices ( up to @xmath0 , meaning a new world record ) for long times ( up to @xmath1 for @xmath2 ) . using this data
, we examined the dynamical critical exponent @xmath3 .
the old assumption of @xmath4 with logarithmic corrections seems very unlikely according to our data , leaving the asymptotic value of @xmath5 .
+ keywords : ising model , critical point , monte carlo , relaxation . .
And you have already written the first three sentences of the full article: although the two - dimensional ising model was solved exactly by onsager in 1944 and much work has been done in this field over the last decades , some questions still remain open .
one is the dynamical critical behaviour .
when we take a lattice with initially all spins up , right at the curie point the magnetization @xmath6 decays with time as @xmath7 , where @xmath8 is the exponent for the spontaneous magnetization and @xmath9 is the exponent for the correlation length ; both are known exactly ..
Please generate the next two sentences of the article | two main suggestions have been made for the value of @xmath3 in glauber kinetics : one is @xmath5 asymptotically , with simple power law behaviour ( @xcite , @xcite , @xcite ) , the other is @xmath10 with logarithmic corrections to the power law behaviour .
the latter was suggested by domany @xcite and later by swendsen @xcite . |
8,052 | Suppose that you have an abstract for a scientific paper: nucleon drift and diffusion mechanisms in central collisions of asymmetric heavy - ions at near - barrier energies are investigated in the framework of a stochastic mean - field approach .
expressions for diffusion and drift coefficients for nucleon transfer deduced from the stochastic mean - field approach in the semiclassical approximation have similar forms familiar from the phenomenological nucleon exchange model .
the variance of fragment mass distribution agrees with the empirical formula @xmath0 .
the comparison with the time - dependent hartree - fock calculations shows that , below barrier energies , the drift coefficient in the semiclassical approximation underestimates the mean number of nucleon transfer obtained in the quantal framework .
motion of the window in the dinuclear system has a significant effect on the nucleon transfer in asymmetric collisions . .
And you have already written the first three sentences of the full article: in heavy - ion collisions with bombarding energies per nucleon in the order of nucleon binding energy , the mean - field approach , in terms of time - dependent hartree - fock equations ( tdhf ) , provides a good approximation for describing the average behavior of the collision dynamics @xcite .
for example , the mean - field approximation gives a good description of energy dissipation and nucleon drift in deep inelastic heavy - ion collisions ( dic ) .
however , the collective motion is treated in nearly classical , deterministic manner and the fluctuations of collective variables are severely underestimated @xcite ..
Please generate the next two sentences of the article | therefore , in the mean - field approach , it is not possible to describe energy distributions and fragment mass and charge distributions in dic .
there are other reactions , such as heavy - ion fusion at near - barrier energies , spinodal dynamics leading to nuclear fragmentation @xcite , in which dynamics of density fluctuations play a dominant role . |
8,053 | Suppose that you have an abstract for a scientific paper: when introducing special relativity , an elegant connection to familiar rules governing galilean constant acceleration can be made , by describing first the discovery at high speeds that the clocks ( as well as odometers ) of different travelers may proceed at different rates .
one may then show how to parameterize any given interval of constant acceleration with _ either _ : newtonian ( low - velocity approximation ) time , inertial relativistic ( unaccelerated observer ) time , or traveler proper ( accelerated observer ) time , by defining separate velocities for each of these three kinematics as well .
kinematic invariance remains intact for proper acceleration since @xmath0 .
this approach allows students to solve relativistic constant acceleration problems _ with the newtonian equations _
! it also points up the self - contained and special nature of the accelerated - observer kinematic , with its frame - invariant time , 4-vector velocities which in traveler terms exceed newtonian values and the speed of light , and of course relativistic momentum conservation . ; umstl - cme-951101pf ; gr - qc/9512012 .
And you have already written the first three sentences of the full article: paradigm changes in physics are often accompanied by a transformation of language and a hardening of distinctions .
thus the emphasis on acceleration as the second time derivative of displacement _ in teaching newtonian dynamics _ has hardened @xcite , even as the concept of relativistic mass and inertial frame acceleration is being slowly replaced by lorentz covariant definitions of force and acceleration _ in the teaching of special relativity _ @xcite .
the intent of this note is to assist the second process by showing that : ( i ) introduction of three relativistic time - parameterizations , _ including the newtonian one _ , provides a natural bridge for introductory physics students to some deep truths about relativistic space - time before the comparatively abstract concept of lorentz transforms need be introduced , and ( ii ) there are two relativistic alternatives to the popular inertial - frame perspective , which perspective sometimes makes velocity - dependent mass a tempting simplification @xcite , questions the special - relativistic treatability of acceleration @xcite , and implies that travelers as well as spectators are _ bound _ by inertial velocity light - speed limits @xcite ..
Please generate the next two sentences of the article | we also show why students here have said that `` without the 82 nano - roddenberry speed - limit , and with the right vehicle , it s amazing how little of my time it would take for me to get from point a to point b ! ''
we consider in this paper only one - dimensional constant acceleration , and only observers using the same inertial frame spatial coordinate with which to measure change of position @xmath1 . |
8,054 | Suppose that you have an abstract for a scientific paper: protostellar sources in star forming regions are responsible for driving jets with flow velocities ranging between 300 and 400 km s@xmath0 .
this class of jets consists of highly collimated outflows which include thermal knots with number densities estimated to be greater than that of their ambient medium .
on the other hand , extragalactic fr i jets consist of light fluid with low mach number burrowing through a denser medium as the magnetized jets radiate nonthermal emission . both protostellar and extragalactic jets are believed to be launched by accretion disks .
here we consider a jet model in which the characteristics common to both protostellar and extragalactic jets are used to explain the origin of nonthermal filaments in the galactic center region .
we argue that these filaments are analogous to fr i extragalactic sources but are launched by embedded young stars or clusters of stars in star - forming regions . .
And you have already written the first three sentences of the full article: it has been 20 years since the discovery of the nonthermal radio filaments ( nrfs ) associated with the galactic center arc was first reported ( yusef - zadeh , morris , & chance 1984 ) .
these observations showed evidence of linear , magnetized features running perpendicular to the galactic plane .
a number of nrfs with similar characteristics to the prototype nrfs have been discovered in the intervening years ( yusef - zadeh 2003 and references therein ) ..
Please generate the next two sentences of the article | several models have suggested that the filaments trace the illuminated component of a large - scale poloidal magnetic field pervasive throughout the galactic center region .
however , the presence of a number of filaments oriented at large angles to the normal to the galactic plane does not support the above interpretation and indicates a different origin . |
8,055 | Suppose that you have an abstract for a scientific paper: the interlayer magnetoresistance of a quasi - one - dimensional fermi liquid is considered for the case of a magnetic field that is rotated within the plane perpendicular to the most - conducting direction . within semi - classical transport theory dips in the magnetoresistance occur at integer `` magic angles '' only when the electronic dispersion parallel to chains is nonlinear .
if the field direction is fixed at one of the magic angles and the temperature is varied then the resulting variation of the scattering rate can lead to a non - monotonic variation of the interlayer magnetoresistance with temperature .
although the model considered here gives a good description of some of the properties of the bechgaard salts , ( tmtsf)@xmath0pf@xmath1 for pressures less than 8 kbar and ( tmtsf)@xmath0clo@xmath2 it gives a poor description of their properties when the field is parallel to the layers and of the intralayer transport . .
And you have already written the first three sentences of the full article: in spite of intensive research over the past decade the nature of the metallic state in low - dimensional strongly correlated materials is still poorly understood .
widely studied materials include cuprate and organic superconductors@xcite .
many of the properties of the cuprates can not be understood within the fermi liquid picture that has so successfully described conventional metals @xcite ..
Please generate the next two sentences of the article | although some properties of the quasi - two - dimensional molecular crystals , @xmath3-(bedt - ttf)@xmath4x ( reference@xcite ) and the quasi - one - dimensional bechgaard salts@xcite ( tmtsf)@xmath0x can be explained within a fermi liquid framework others can not .
a particular challenge is understanding the dependence of the magnetoresistance of the bechgaard salts on the direction of the magnetic field , especially ( tmtsf)@xmath0pf@xmath5 under pressures of about 10 kbar @xcite . |
8,056 | Suppose that you have an abstract for a scientific paper: niels bohr wrote : there is no quantum world .
there is only an abstract quantum physical description .
it is wrong to think that the task of physics is to find out how nature is .
physics concerns what we can say about nature .
in an analogous way , von weizscker suggested that the notion of the elementary alternative , the `` ur '' , should play a pivotal role when constructing physics .
both approaches suggest that the concept of information should play an essential role in the foundations of any scientific description of nature .
we show that if , in our description of nature , we use one definite proposition per elementary constituent of nature , some of the essential characteristics of quantum physics , such as the irreducible randomness of individual events , quantum complementary and quantum entanglement , arise in a natural way .
then quantum physics is an elementary theory of information . *
dedicated to prof . c. f. von weizscker at the occasion of his @xmath0 birthday . * .
And you have already written the first three sentences of the full article: all our description of objects is represented by propositions .
the use of propositions is not a matter of our choice .
in contrast , it is a necessity which is behind each of our attempts to learn something new about nature and to communicate this knowledge with others . it is a necessity which we follow constantly and without any intention and it seems that there is no way to avoid it even if the phenomena to be described and to be understood are highly counterintuitive and distinct from both our everyday experience and the classical world view ..
Please generate the next two sentences of the article | one may even say that there is no need to avoid it .
the reason is that the only way we are able to understand any phenomena in nature , including quantum phenomena , is exclusively through the epistemological structure of classical physics and everyday experience . |
8,057 | Suppose that you have an abstract for a scientific paper: we undertake the first study of two - planet microlensing models recovered from simulations of microlensing events generated by realistic multi - planet systems in which 292 planetary events including 16 two - planet events were detected from 6690 simulated light curves .
we find that when two planets are recovered , their parameters are usually close to those of the two planets in the system most responsible for the perturbations .
however , in one of the 16 examples , the apparent mass of both detected planets was more than doubled by the unmodeled influence of a third , massive planet .
this fraction is larger than , but statistically consistent with , the roughly 1.5% rate of serious mass errors due to unmodeled planetary companions for the 274 cases from the same simulation in which a single planet is recovered .
we conjecture that an analogous effect due to unmodeled stellar companions may occur more frequently . for seven out of 23 cases
in which two planets in the system would have been detected separately , only one planet was recovered because the perturbations due to the two planets had similar forms .
this is a small fraction ( 7/274 ) of all recovered single - planet models , but almost a third of all events that might plausibly have led to two - planet models .
still , in these cases , the recovered planet tends to have parameters similar to one of the two real planets most responsible for the anomaly . .
And you have already written the first three sentences of the full article: microlensing is an important method in detecting extrasolar planets .
it is sensitive to planets around the einstein radius @xcite @xmath0 where @xmath1 is the lens mass , @xmath2 is the lens - source relative parallax , and @xmath3 and @xmath4 are the distances to the lens and source , respectively . for typical microlensing events
, this angular scale corresponds to a physical size on the lens plane ( @xmath5 ) that typically lies somewhat beyond the `` snow line '' , the region that is believed to be the birth place of giant planets ( e.g. , * ? ? ?.
Please generate the next two sentences of the article | to date , dozens of microlensing planets have been detected , enabling statistical studies of the frequency of distant bound planets @xcite , and unbound `` free - floating planets '' @xcite .
however , among dozens of microlensing events that have yielded planet detections , only two systems securely contain two planets @xcite , although most planets are believed to have been formed in multiple - planet systems . |
8,058 | Suppose that you have an abstract for a scientific paper: we provide a precise definition and analysis of quantum causal histories ( qch s ) .
a qch consists of a discrete , locally finite , causal pre - spacetime with matrix algebras encoding the quantum structure at each event .
the evolution of quantum states and observables is described by completely positive maps between the algebras at causally related events .
we show that this local description of evolution is sufficient and that unitary evolution can be recovered wherever it should actually be expected .
this formalism may describe a quantum cosmology without an assumption of global hyperbolicity ; it is thus more general than the wheeler - dewitt approach .
the structure of a qch is also closely related to quantum information theory and algebraic quantum field theory on a causal set .
l + + + .
And you have already written the first three sentences of the full article: the quest for a quantum theory of gravity is now several decades old and has been studied with approaches ranging from string theory and non - commutative geometry to loop quantum gravity , spin foams , and discrete models of planck - scale spacetime .
most of these take different interpretations of what a quantum theory of gravity should achieve , but with one thing in common : that it should be some merger of general relativity and quantum theory
. the final goal has not yet been achieved , but all these approaches have brought to us new understandings of the problem . we come to the motivation for this paper by putting together a consistent list of features , selectively chosen from among the various indications of what a quantum theory of gravity may be ..
Please generate the next two sentences of the article | such a list is by no means unique , but we will find that it is fruitful ; it leads to a new notion of quantum cosmology and a new formulation of evolution in a planck - scale theory .
our list is the following : 1 ) at energies close to the planck scale , the description of spacetime as a continuous , @xmath0-dimensional manifold breaks down ; this is the usual idea for regularization of quantum field theory . |
8,059 | Suppose that you have an abstract for a scientific paper: the main aim of the present paper is the very first analysis of the binary - orbit precession out of our galaxy .
the light curves of an eclipsing binary macho 82.8043.171 in the large magellanic cloud ( lmc ) were studied in order to analyse the long - term evolution of its orbit .
it is a detached system that is undergoing rapid orbit precession .
the inclination of the orbit towards the observer has been changing , which has caused the eclipse depth to become lower over the past decade , and this is ongoing .
the period of this effect was derived as only about 77 years , so it is the second fastest nodal motion known amongst such systems nowadays .
this is the first analysis of an extragalactic binary with nodal precession .
this effect is probably caused by a distant third body orbiting the pair , which could potentially be detected via spectroscopy .
some preliminary estimates of this body are presented . however
, even such a result can tell us something about the multiplicity fraction in other galaxies . .
And you have already written the first three sentences of the full article: after more than a century of intensive study of eclipsing binaries ( hereafter ebs ) , they still represent the best method for deriving the masses , radii , and luminosities of stars . thanks to modern ( ground- and space- based ) telescopes , we are able to also study these objects in other galaxies and to apply the same methods as used in our solar neighbourhood . nevertheless , there is still a difference in the precision of eb parameters as derived for galactic ( @xmath02 - 3% ) and extragalactic ( @xmath010% ) eclipsing binaries ( see e.g. @xcite , @xcite ) .
the extragalactic ebs can serve as an independent tool for deriving galactic properties and also help us answer such important questions as `` is the chemical composition of our galaxy the same as the neighbouring ones ? '' or `` what is the binary and multiplicity fraction in other galaxies ? '' studying other galaxies via detailed analysis of individual stars can provide some useful hints for answering these questions .
ebs are quite common , even in some nearby galaxies ..
Please generate the next two sentences of the article | however , one special group of ebs is still rather rare - those undergoing an orbit precession . if the orientation of the eb orbit is moving in space , then the depths of eclipse also change , and we can detect this orbit precession . observing the binary at different time epochs
can help us to derive the inclination towards the observer as a function of time . |
8,060 | Suppose that you have an abstract for a scientific paper: we consider the algebro - geometric consequences of integration by parts .
4.5 mm * 2000 mathematics subject classification : * 32 , 14 . * keywords and phrases : * jensen s formula . .
And you have already written the first three sentences of the full article: -5 mm recall that for a suitably regular function @xmath0 on the unit disc @xmath1 we can apply integration by parts / stoke s formula twice to obtain for @xmath2 , @xmath3 where @xmath4 so actually we re integrating @xmath5 . in the presence of singularities things
continue to work . for example
suppose @xmath6 is a holomorphic map of complex spaces and @xmath7 a metricised effective cartier divisor on @xmath8 , with @xmath9 , and @xmath10 , where @xmath11 is the tautological section , then we obtain , @xmath12 obviously it s not difficult to write down similar formulae for not necessarily effective cartier divisors , meromorphic functions , drop the condition that @xmath9 provided @xmath13 , extend to ramified covers @xmath14 , etc . , but in all cases what is clear is , * facts 1.3 ..
Please generate the next two sentences of the article | * _ ( a ) if @xmath8 is compact then @xmath15 is very close to being positive if @xmath16 , e.g. in the particular hypothesis preceding ( 1.2 ) , @xmath17 _
\(b ) there is no such principle for the usual area function @xmath18 except in extremely special cases such as @xmath19 ample . |
8,061 | Suppose that you have an abstract for a scientific paper: the properties of the localized states of a two component bose - einstein condensate confined in a nonlinear periodic potential [ nonlinear optical lattice ] are investigated .
we reveal the existence of new types of solitons and study their stability by means of analytical and numerical approaches .
the symmetry properties of the localized states with respect to the nol are also investigated .
we show that nonlinear optical lattices allow the existence of bright soliton modes with equal symmetry in both components , bright localized modes of mixed symmetry type , as well as , dark - bright bound states and bright modes on periodic backgrounds . in spite of the quasi 1d nature of the problem ,
the fundamental symmetric localized modes undergo a delocalizing transition when the strength of the nonlinear optical lattice is varied .
this transition is associated with the existence of an unstable solution , which exhibits a shrinking ( decaying ) behavior for slightly overcritical ( undercritical ) variations in the number of atoms . .
And you have already written the first three sentences of the full article: bose - einstein condensates ( bec ) in optical lattices ( ol ) have recently attracted a great deal of attention due to the possibility of investigating , both at the theoretical and at the experimental level , interesting physical phenomena such as bloch oscillations , landau zener tunneling , mott transitions , etc . @xcite .
the interplay between the nonlinearity ( intrinsic in the interatomic interaction ) and the periodic structure ( induced by the ol ) leads to the formation of localized states trough the mechanism of the modulational instability of the bloch states at the edges of the brillouin zone of the underlying linear periodic system @xcite .
these states , also known as gap - solitons , can exist in presence of both attractive and repulsive interactions @xcite , this last fact being possible only due to the presence of the ol . the existence of gap solitons in repulsive bec was experimentally demonstrated in @xcite ..
Please generate the next two sentences of the article | the phenomena of bloch oscillations , generation of coherent atomic pulses ( atom laser)@xcite , superfluid - mott transition@xcite , were also experimentally observed .
the ols considered in these experiments act as external potentials ( and therefore linearly ) on the condensate , this introducing an intrinsic ( state independent ) periodicity in the system . in the following |
8,062 | Suppose that you have an abstract for a scientific paper: electron tunneling through a two stage kondo system constituted by a double quantum - dot molecule side coupled to a quantum wire , under the effect of a finite external potential is studied .
we found that @xmath0-@xmath1 characteristic shows a negative differential conductance region induced by the electronic correlation .
this phenomenon is a consequence of the properties of the two stage kondo regime under the effect of an external applied potential that takes the system out of equilibrium .
the problem is solved using the mean - field finite-@xmath2 slave - boson formalism . .
And you have already written the first three sentences of the full article: many devices exhibit negative differential conductance ( @xmath3 ) as multiple quantum wells , double barrier , double quantum dots , etc ndc1,ndc2,ndc3,ndc4,dqd1,dqds .
the @xmath3 has applications as amplifiers and oscillators in the microwave , mm - wave and terahertz frequency range .
extensive experimental and theoretical investigation have been devoted to the study of the @xmath0-@xmath1 characteristics and @xmath3 phenomenon in double quantum dot molecules @xcite ..
Please generate the next two sentences of the article | moreover , there is a wide literature on transport through double quantum dots ( @xmath4 ) in different geometries , e.g , @xmath4 in series and in parallel @xcite .
two aspects of electronic transport through quantum dots have attracted great attention in the last years , the coulomb blockade effect and the kondo effect . recently |
8,063 | Suppose that you have an abstract for a scientific paper: an intriguing trend among _ kepler _ s multi - planet systems is an overabundance of planet pairs with period ratios just wide of mean motion resonances ( mmr ) and a dearth of systems just narrow of them . in a recently published paper @xcite has proposed that gas - disk migration traps planets in a mmr .
after gas dispersal , orbits of these trapped planets are altered through interaction with a residual planetesimal disk .
they found that for massive enough disks planet - planetesimal disk interactions can break resonances and naturally create moderate to large positive offsets from the initial period ratio for large ranges of planetesimal disk and planet properties .
divergence from resonance only happens if the mass of planetesimals that interact with the planets is at least a few percent of the total planet mass .
this threshold , above which resonances are broken and the offset from resonances can grow , naturally explains why the asymmetric large offsets were not seen in more massive planet pairs found via past radial velocity surveys . in this article
we will highlight some of the key findings of cf15 .
in addition , we report preliminary results from an extension of this study , that investigates the effects of planet - planetesimal disk interactions on initially non - resonant planet pairs . we find that planetesimal scattering typically increases period ratios of non - resonant planets
. if the initial period ratios are below and in proximity of a resonance , under certain conditions , this increment in period ratios can create a deficit of systems with period ratios just below the exact integer corresponding to the mmr and an excess just above . from an initially uniform distribution of period ratios just below a 2:1 mmr
, planetesimal interactions can create an asymmetric distribution across this mmr similar to what is observed for the _ kepler _ planet pairs . .
And you have already written the first three sentences of the full article: nasa s _ kepler _ mission has revolutionized our understanding of planetary systems , their occurrence rate , multiplicity and physical properties .
one trend apparent among this new class of small planets was a - priori quite unexpected from traditional theories ; there is a statistically significant excess of planet pairs with period ratios slightly wide of first order mean motion resonances such as 2:1 and 3:2 , and a dearth of them just narrow of these resonances ( @xcite ; figure [ fig : obs ] ) .
interestingly , this trend is absent in planets that were previously discovered via radial velocity ( rv ) surveys ( e.g. , @xcite ) ..
Please generate the next two sentences of the article | smooth gas - disk migration can trap planets in mmrs .
however , such resonant planets are expected to have period ratios with very small offsets from the integer ratio corresponding to the mmr , @xmath0 . |
8,064 | Suppose that you have an abstract for a scientific paper: the onset and characteristics of micro - tearing modes ( mtm ) in the core of spherical ( nstx ) and conventional tokamaks ( asdex - ug and jet ) are studied through local linear gyrokinetic simulations with gyro [ j. candy and e. belli , general atomics report ga - a26818 ( 2011 ) ] . for experimentally relevant core plasma parameters in the nstx and asdex - ug tokamaks , in agreement with previous works ,
we find mtms as the dominant linear instability .
also , for jet - like core parameters considered in our study an mtm is found as the most unstable mode . in all these plasmas ,
finite collisionality is needed for mtms to become unstable and the electron temperature gradient is found to be the fundamental drive .
however , a significant difference is observed in the dependence of linear growth rate of mtms on electron temperature gradient .
while it varies weakly and non - monotonically in jet and asdex - ug plasmas , in nstx it increases with the electron temperature gradient . .
And you have already written the first three sentences of the full article: in recent years , specially in view of an increasing interest in high @xmath0 operation scenarios , such as hybrid scenarios for iter @xcite , the impact of electromagnetic effects on the particle and heat transport has attracted much attention .
here @xmath1 , where @xmath2 and @xmath3 are the electron density and temperature .
@xmath4 is defined as the effective field strength @xcite ..
Please generate the next two sentences of the article | recent reports have shown the significant role of electromagnetic modes such as micro - tearing modes ( mtms ) on the electron heat transport in the core of fusion plasmas @xcite .
it has been found that in plasmas where @xmath0 and collisionality are sufficiently high mtms can become the dominant instability . under these conditions , |
8,065 | Suppose that you have an abstract for a scientific paper: the resonant substructure of @xmath0 decays is studied using a data sample corresponding to an integrated luminosity of @xmath1 of @xmath2 collision data recorded by the lhcb detector .
an excess at @xmath3 is found to be an admixture of spin-1 and spin-3 resonances .
therefore the @xmath4 state previously observed in inclusive @xmath5 and @xmath6 processes consists of at least two particles .
this is the first observation of a heavy flavoured spin-3 resonance , and the first time that any spin-3 particle has been seen to be produced in decays .
the masses and widths of the new states and of the @xmath7 meson are measured , giving the most precise determinations to date .
= 1 european organization for nuclear research ( cern ) lc@r + & & cern - ph - ep-2014 - 183 + & & lhcb - paper-2014 - 035 + & & 20 october 2014 + & & + * * observation of overlapping spin-1 and spin-3 @xmath8 resonances at mass @xmath9 the lhcb collaboration published in phys .
rev .
lett .
cern on behalf of the collaboration , license http://creativecommons.org/licenses/by/4.0/[cc-by-4.0 ] .
studies of heavy meson spectroscopy provide an important probe of quantum chromodynamics .
the observations of the @xmath10 @xcite and @xmath11 @xcite mesons led to renewed activity in the field , as their masses were found to be below the @xmath12 and @xmath13 thresholds , respectively , in contrast to prior predictions .
these states are usually interpreted as being two of the orbitally excited ( 1p ) charm - strange states , the other two being the @xmath14 and @xmath15 resonances .
several other charm - strange states , the @xmath16 , @xmath17 and @xmath18 resonances , have been discovered @xcite . however , their quantum numbers and spectroscopic assignments are not known , with the exception of the @xmath16 meson , which has spin - parity @xmath19 and is generally believed to be a radially excited ( 2s ) state .
reviews of the expectations in theoretical models can be found in refs .
....
And you have already written the first three sentences of the full article: we express our gratitude to our colleagues in the cern accelerator departments for the excellent performance of the lhc .
we thank the technical and administrative staff at the lhcb institutes .
we acknowledge support from cern and from the national agencies : capes , cnpq , faperj and finep ( brazil ) ; nsfc ( china ) ; cnrs / in2p3 ( france ) ; bmbf , dfg , hgf and mpg ( germany ) ; sfi ( ireland ) ; infn ( italy ) ; fom and nwo ( the netherlands ) ; mnisw and ncn ( poland ) ; men / ifa ( romania ) ; mines and fano ( russia ) ; mineco ( spain ) ; snsf and ser ( switzerland ) ; nasu ( ukraine ) ; stfc ( united kingdom ) ; nsf ( usa ) ..
Please generate the next two sentences of the article | the tier1 computing centres are supported by in2p3 ( france ) , kit and bmbf ( germany ) , infn ( italy ) , nwo and surf ( the netherlands ) , pic ( spain ) , gridpp ( united kingdom ) .
we are indebted to the communities behind the multiple open source software packages on which we depend . |
8,066 | Suppose that you have an abstract for a scientific paper: we study a wiener disorder problem of detecting the minimum of @xmath0 change - points in @xmath0 observation channels coupled by correlated noises . it is assumed that the observations in each dimension can have different strengths and that the change - points may differ from channel to channel .
the objective is the quickest detection of the minimum of the @xmath0 change - points .
we adopt a min
max approach and consider an extended lorden s criterion , which is minimized subject to a constraint on the mean time to the first false alarm .
it is seen that , under partial information of the post - change drifts and a general nonsingular stochastic correlation structure in the noises , the minimum of @xmath0 cumulative sums ( cusum ) stopping rules is asymptotically optimal as the mean time to the first false alarm increases without bound .
we further discuss applications of this result with emphasis on its implications to the efficiency of the decentralized versus the centralized systems of observations which arise in engineering .
./style / arxiv - general.cfg , .
And you have already written the first three sentences of the full article: the problem of quickest detection has been known in the engineering literature since the 1930s . since then
there have been various analytical considerations of the quickest detection problem in a variety of models and setups ( see @xcite for an overview ) .
the quickest detection problem , also known as the disorder problem , concerns the detection of a change point in the statistical behavior of a stream of sequential observations . the objective is to blanace the trade off between a small detection delay and small frequency of false alarms . of this problem.
Please generate the next two sentences of the article | there are two main formulations , the bayesian and the min max . in the former , the change point or disorder time
is assumed to have an a priori distribution usually independent of the observation process while in the latter it is assumed to be an unknown constant . |
8,067 | Suppose that you have an abstract for a scientific paper: we propose a scheme for inverse engineering control in open quantum systems . starting from an undetermined time evolution operator ,
a time - dependent hamiltonian is derived in order to guide the system to attain an arbitrary target state at a predefined time .
we calculate the fidelity of our inverse engineering control protocol in presence of the noise with respect to the stochastic fluctuation of the linear parameters of the hamiltonian during the time evolution . for a special family of hamiltonians for two - level systems , we show that the control evolution of the system under noise can be categorized into two standard decohering processes : dephasing and depolarization , for both markovian and non - markovian conditions .
in particular , we illustrate our formalism by analysing the robustness of the engineered target state against errors .
moreover , we discuss the generalization of the inverse protocol for higher - dimensional systems . .
And you have already written the first three sentences of the full article: to fulfill the requirement of high - precision quantum gates , teleportation , or state transfer , the aim of quantum state engineering ( qse ) @xcite is to manipulate the system and attain a target state , typically a pure state , at a designed time @xmath0 ; or more ambitiously , to drive the eigenstates of an initial hamiltonian into those of a final hamiltonian @xcite . to be concrete , for a two - level system
, a passage is constructed through which the system undergoes a transition from an initial state @xmath1 to a final state @xmath2 , with @xmath3 , in an undisturbed way . in a closed - system scenario ,
qse has been considered through time optimal evolution @xcite and robust protocols of realizing qse have been provided by adiabatic passages @xcite and by sequential convex programming @xcite . however , for open systems @xcite , which are under environmental noise due to the onset of the system - bath dynamics @xcite , qse is significantly challenged in both theoretical and experimental implementations . indeed , for decohering systems.
Please generate the next two sentences of the article | , there is a competition between the time required for adiabaticity and the decoherence time scales @xcite , which may limit the applicability of the adiabatic approach @xcite .
identifying protocols that are both fast and fault - tolerant is therefore an important research direction for quantum information processing and quantum control @xcite . |
8,068 | Suppose that you have an abstract for a scientific paper: the strong cp problem was solved by peccei & quinn by introducing axions , which are a viable candidate for dm . here
the pq approach is modified so to yield also dark energy ( de ) , which arises in fair proportions , without tuning any extra parameter .
dm and de arise from a single scalar field and , in the present ecpoch , are weakly coupled .
fluctuations have a fair evolution .
the model is also fitted to wmap release , using a mcmc technique , and performs as well as lcdm , coupled or uncoupled dynamical de .
fit cosmological parameters for different models are mostly within 2@xmath0 level .
the main peculiarity of the model is to favor high values of the hubble parameter . .
And you have already written the first three sentences of the full article: axions are likely to be the dark matter ( dm ) that cosmological data require .
axions arise from the solution of the strong @xmath1 problem proposed by peccei & quinn in 1977 ( @xcite , pq hereafter ) , who suggested that @xmath2 parameter , in the effective lagrangian term @xmath3 ( @xmath4 : strong coupling constant , @xmath5 : gluon field tensor ) , causing @xmath1 violations in strong interactions , is a dynamical variable . under suitable conditions @xmath2 approaches zero in our epoch , so that the term ( [ eq : n1 ] ) is suppressed , while residual @xmath2 oscillations yield dm @xcite . in the pq scheme ,
@xmath2 is the phase of a complex field @xmath6 ; its evolution is set by the potential @xmath7 ^ 2 ~ , \label{eq : n2}\ ] ] whose @xmath8 invariance breaks when @xmath9 ( the pq energy scale , which shall be @xmath10gev ).
Please generate the next two sentences of the article | . then @xmath11 settles at the potential minimum , while @xmath2 takes a random value , different in different horizons . when chiral symmetry also breaks down , during the quark
hadron transition , a further term @xmath12 |
8,069 | Suppose that you have an abstract for a scientific paper: we study a significant nuclear suppression of the relative production rates ( p(d)+a)/(p+d(p ) ) for the drell - yan process at large feynman @xmath0 . since this is the region of minimal values for the light - front momentum fraction variable @xmath1 in the target nucleus , it is tempting to interpret this as a manifestation of coherence or of a color glass condensate .
we demonstrate , however , that this suppression mechanism is governed by the energy conservation restrictions in multiple parton rescatterings in nuclear matter . to eliminate nuclear shadowing effects coming from the coherence ,
we calculate nuclear suppression in the light - cone dipole approach at large dilepton masses and at energy accessible at fnal .
our calculations are in a good agreement with data from the e772 experiment . using the same mechanism we predict also nuclear suppression at forward rapidities in the rhic energy range . .
And you have already written the first three sentences of the full article: recent study of small-@xmath2 physics is realized at rhic by measurements of high-@xmath3 particles in @xmath4 collisions at forward rapidities @xmath5 @xcite .
if a particle with mass @xmath6 and transverse momentum @xmath3 is produced in a hard reaction then the corresponding values of bjorken variable in the beam and the target are @xmath7 .
thus , at forward rapidities the target @xmath1 is @xmath8- times smaller than at midrapidities ..
Please generate the next two sentences of the article | this allows to study coherent phenomena ( shadowing , color glass condensate ( cgc ) ) , which are expected to suppress particle yields .
however , a significant suppression at large @xmath9 for any reaction is observed so far at any energy . |
8,070 | Suppose that you have an abstract for a scientific paper: many - body systems constructed of quantum - optical building blocks can now be realized in experimental platforms ranging from exciton - polariton fluids to ultracold gases of rydberg atoms , establishing a fascinating interface between traditional many - body physics and the driven - dissipative , non - equilibrium setting of cavity - qed . at this interface ,
the standard techniques and intuitions of both fields are called into question , obscuring issues as fundamental as the role of fluctuations , dimensionality , and symmetry on the nature of collective behavior and phase transitions . here , we study the driven - dissipative bose - hubbard model , a minimal description of numerous atomic , optical , and solid - state systems in which particle loss
is countered by coherent driving . despite being a lattice version of optical bistability
a foundational and patently _ non - equilibrium _ model of cavity - qed the steady state possesses an emergent _ equilibrium _ description in terms of a classical ising model .
we establish this picture by identifying a limit in which the quantum dynamics is asymptotically equivalent to non - equilibrium langevin equations , which support a phase transition described by model a of the hohenberg - halperin classification .
numerical simulations of the langevin equations corroborate this picture , producing results consistent with the behavior of a finite - temperature ising model . .
And you have already written the first three sentences of the full article: while cavity - qed systems often contain many interacting degrees of freedom , they are unconventional from the standpoint of traditional many - body physics for two primary reasons
. first , the mediation of interactions through a small number of delocalized cavity modes generally leads to extremely long - ranged interactions @xcite , which suppress the role of fluctuations and often enable accurate mean - field descriptions .
in this sense they are simpler than conventional solid - state realizations of many - body physics , in which short - range interactions promote both quantum and thermal fluctuations to an important role , especially in low spatial dimensions @xcite ..
Please generate the next two sentences of the article | second , cavity - qed systems are typically driven and dissipative ; as a result , even if they reach a time - independent steady state they will generally not be in thermal equilibrium @xcite . in this sense
they are more complicated than conventional solid - state realizations of many - body physics , in which coupling to a thermal reservoir is typically assumed and well justified , leaving the system in thermal equilibrium and enabling the powerful tools of statistical mechanics to be employed @xcite . in recent years |
8,071 | Suppose that you have an abstract for a scientific paper: semileptonic and nonleptonic decays of the @xmath0 meson to charmonium and @xmath1 mesons are studied in the framework of the relativistic quark model .
the decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range .
the relativistic meson wave functions are used for the calculation of the decay rates .
the obtained results are compared with the predictions of other approaches . .
And you have already written the first three sentences of the full article: the investigation of weak decays of mesons composed of a heavy quark and antiquark gives a very important insight in the heavy quark dynamics .
the properties of the @xmath0 meson are of special interest , since it is the only heavy meson consisting of two heavy quarks with different flavor .
this difference of quark flavors forbids annihilation into gluons . as a result ,.
Please generate the next two sentences of the article | the excited @xmath0 meson states lying below the @xmath2 production threshold undergo pionic or radiative transitions to the pseudoscalar ground state which is considerably more stable than corresponding charmonium or bottomonium states and decays only weakly . the collider detector at fermilab ( cdf ) collaboration @xcite reported the discovery of the @xmath0 ground state in @xmath3 collisions .
more experimental data are expected to come in near future from the tevatron and large hadron collider ( lhc ) . |
8,072 | Suppose that you have an abstract for a scientific paper: we study the relevance of various scalar equations , such as inviscid burgers , korteweg - de vries ( kdv ) , extended kdv , and higher order equations ( of camassa - holm type ) , as asymptotic models for the propagation of internal waves in a two - fluid system .
these scalar evolution equations may be justified with two approaches .
the first method consists in approximating the flow with two decoupled , counterpropagating waves , each one satisfying such an equation .
one also recovers homologous equations when focusing on a given direction of propagation , and seeking unidirectional approximate solutions .
this second justification is more restrictive as for the admissible initial data , but yields greater accuracy .
additionally , we present several new coupled asymptotic models : a green - naghdi type model , its simplified version in the so - called camassa - holm regime , and a weakly decoupled model .
all of the models are rigorously justified in the sense of consistency . .
And you have already written the first three sentences of the full article: in this paper , we study asymptotic models for the propagation of internal waves in a two - fluid system , which consists in two layers of immiscible , homogeneous , ideal , incompressible and irrotational fluids under the only influence of gravity .
we assume that there is no topography ( the bottom is flat ) and that the surface is confined by a flat rigid lid , although the case of a free surface could be handled with our method .
the interface between the two layers of fluids is given as the graph of a function , @xmath0 , which expresses the deviation from its rest position @xmath1 at the spatial coordinate @xmath2 and at time @xmath3 ..
Please generate the next two sentences of the article | as we will focus on scalar models , we restrict ourselves to the case of horizontal dimension one .
the governing equations of such a system , describing the evolution of the deformation of the interface , @xmath0 , as well as the velocity flow inside the two layers of fluid is recalled in figure [ fig : sketchofdomain ] ( see section [ sec : models ] for more details ) . |
8,073 | Suppose that you have an abstract for a scientific paper: we will display the fundamental structure of classical electrodynamics . starting from the axioms of ( 1 ) electric charge conservation , ( 2 ) the existence of a lorentz force density , and ( 3 ) magnetic flux conservation , we will derive maxwell s equations .
they are expressed in terms of the field strengths @xmath0 , the excitations @xmath1 , and the sources @xmath2 .
this fundamental set of four microphysical equations has to be supplemented by somewhat less general constitutive assumptions in order to make it a fully determined system with a well - posed initial value problem .
it is only at this stage that a distance concept ( metric ) is required for space - time .
we will discuss one set of possible constitutive assumptions , namely @xmath3 and @xmath4 .
_ file erik8a.tex , 1999 - 07 - 27 _ .
And you have already written the first three sentences of the full article: is it worthwhile to reinvent classical electrodynamics after it has been with us for more than a century ? and after its quantized version , quantum electrodynamics ( unified with the weak interaction ) had turned out to be one of the most accurately tested successful theories ?
we believe that the answer should be affirmative .
moreover , we believe that this reformulation should be done such that it is also comprehensible and useful for experimental physicists and ( electrical ) engineers ..
Please generate the next two sentences of the article | let us collect some of the reasons in favor of such a reformulation .
first of all an `` axiomatics '' of electrodynamics should allow us to make the fundamental structure of electrodynamics transparent , see , e.g. , sommerfeld @xcite or @xcite . |
8,074 | Suppose that you have an abstract for a scientific paper: linear optics underpins tests of fundamental quantum mechanics and computer science , as well as quantum technologies . here
we experimentally demonstrate the longstanding goal of a single reprogrammable optical circuit that is sufficient to implement all possible linear optical protocols up to the size of that circuit .
our six - mode universal system consists of a cascade of 15 mach - zehnder interferometers with 30 thermo - optic phase shifters integrated into a single photonic chip that is electrically and optically interfaced for arbitrary setting of all phase shifters , input of up to six photons and their measurement with a 12 single - photon detector system .
we programmed this system to implement heralded quantum logic and entangling gates , boson sampling with verification tests , and six - dimensional complex hadamards .
we implemented 100 haar random unitaries with average fidelity 0.999 @xmath0 0.001 .
our system is capable of switching between these and any other linear optical protocol in seconds .
these results point the way to applications across fundamental science and quantum technologies .
[ fig : fig1 ] photonics has been crucial in establishing the foundations of quantum mechanics @xcite , and more recently has pushed the vanguard of efforts in understanding new non - classical computational possibilities .
typical protocols involve nonlinear operations , such as the generation of quantum states of light through optical frequency conversion @xcite , or measurement - induced nonlinearities for quantum logic gates @xcite , together with linear operations between optical modes to implement core processing functions @xcite .
encoding qubits in the polarisation of photons has been particularly appealing for the ability to implement arbitrary linear operations on the two polarisation modes using a series of wave plates @xcite . for path encoding the same operations
can be mapped to a sequence of beamsplitters and phase shifters .
in fact , since any linear....
And you have already written the first three sentences of the full article: as shown in fig . [ fig : fig1](b ) , 808 nm laser light from a 140fs pulsed titanium : sapphire laser was attenuated via a half wave plate ( hwp ) and polarising beam splitter ( pbs ) , before being frequency doubled via a type - i barium borate ( bbo ) nonlinear crystal .
the subsequent 404 nm light was reflected from dichroic mirrors ( dm ) , filtering the 808 nm light into a beam dump ( bd ) , and focused onto a type - i bismuth borate ( bibo ) nonlinear crystal to generate multiple pairs of photons through spontaneous parametric down conversion ( spdc ) . after passing through an interference filter ( if )
photons are collected into four polarisation maintaining fibres ( pmf ) and delivered to the lpu ..
Please generate the next two sentences of the article | + the silica - based planar waveguide circuit is fabricated on a silicon wafer using flame hydrolysis deposition , photolithography and reactive ion etching .
the germanium ( @xmath97 ) doped silica core has a cross sectional dimension of @xmath98 , and is surrounded by a silica cladding yielding a core - cladding refractive index difference of @xmath99 . |
8,075 | Suppose that you have an abstract for a scientific paper: electronic transport in a one - dimensional mesoscopic ring threaded by a magnetic flux is studied in presence of rashba and dresselhaus spin - orbit interactions .
a completely analytical technique within a tight - binding formalism unveils the spin - split bands in presence of the spin - orbit interactions and leads to a method of determining the strength of the dresselhaus interaction .
in addition to this , the persistent currents for ordered and disordered rings have been investigated numerically .
it is observed that , the presence of the spin - orbit interaction , in general , leads to an enhanced amplitude of the persistent current .
numerical results corroborate the respective analytical findings . .
And you have already written the first three sentences of the full article: the spin - orbit ( so ) interaction in mesoscopic and nano - scale semiconductor structures has been at the center stage of research in condensed matter theory and device engineering in recent times .
the principal reason is its potential application in spintronics , where the possibility of manipulating and controlling the spin of the electron rather than its charge , plays the all important role @xcite .
the spin - orbit fields in a solid are called the rsoi or the dsoi depending on whether the electric field originates from a structural inversion asymmetry or the bulk inversion asymmetry respectively @xcite ..
Please generate the next two sentences of the article | quantum rings formed at the interface of two semiconducting materials are ideal candidates where the interplay of the two kinds of soi might be observed . a quantum ring in a heterojunction
is realized when a two dimensional gas of electrons is trapped in a quantum well due to the _ band offset _ at the interface of two different semiconducting materials . |
8,076 | Suppose that you have an abstract for a scientific paper: we report muon spin relaxation ( @xmath0sr ) and magnetization measurements , together with synthesis and characterization , of the li - intercalated layered superconductors li@xmath1hfncl and li@xmath1zrncl with / without co - intercalation of thf ( tetrahydrofuran ) or pc ( propylene carbonate ) .
the 3-dimensional ( 3-d ) superfluid density @xmath2 ( superconducting carrier density / effective mass ) , as well as the two dimensional superfluid density @xmath3 ( 2-dimensional ( 2-d ) area density of superconducting carriers / ab - plane effective mass ) , have been derived from the @xmath0sr results of the magnetic - field penetration depth @xmath4 observed with external magnetic field applied perpendicular to the 2-d honeycomb layer of hfn / zrn . in a plot of @xmath5 versus @xmath3 ,
most of the results lie close to the linear relationship found for underdoped high-@xmath5 cuprate ( htsc ) and layered organic bedt superconductors . in li@xmath1zrncl without thf intercalation , the superfluid density and @xmath5 for @xmath6 = 0.17 and 0.4 do not show much difference , reminiscent of @xmath0sr results for some overdoped htsc systems .
together with the absence of dependence of @xmath5 on average interlayer distance among zrn / hfn layers , these results suggest that the 2-d superfluid density @xmath3 is a dominant determining factor for @xmath5 in the intercalated nitride - chloride systems .
we also report @xmath0sr and magnetization results on depinning of flux vortices , and the magnetization results for the upper critical field @xmath7 and the penetration depth @xmath8 .
reasonable agreement was obtained between @xmath0sr and magnetization estimates of @xmath8 .
we discuss the two dimensional nature of superconductivity in the nitride - chloride systems based on these results .
# 1@xmath9#1 .
And you have already written the first three sentences of the full article: layered superconductors , such as high-@xmath5 cuprates ( htsc ) or organic bedt systems , have been a subject of extensive research effort for decades .
these systems show rich novel phenomena , including superconducting fluctuations , pancake vortex , complicated vortex phase diagrams , and interlayer josephson effects .
cuprate superconductors have been investigated extensively as prototypical layered superconductors ..
Please generate the next two sentences of the article | the cuprates have a merit that their carrier concentration can be controlled by chemical substitutions and/or oxygen contents . on the other hand
, it has not been easy to control the interlayer distance in cuprates . in general , superconductivity of these layered systems |
8,077 | Suppose that you have an abstract for a scientific paper: we develop a picture of dipole - nucleus ( namely dilute - dense ) and dipole - dipole ( dilute - dilute ) scattering in the high - energy regime based on the analysis of the fluctuations in the quantum evolution .
we emphasize the difference in the nature of the fluctuations probed in these two processes respectively , which , interestingly enough , leads to observable differences in the scattering amplitude profiles .
address = centre de physique thorique , cole polytechnique , cnrs , palaiseau , france this paper introduces and summarizes the results recently published in ref .
@xcite , from a less technical viewpoint ( see ref .
@xcite for a complementary presentation ) , and with illustrations from numerical simulations ( see figs . [
fig : dipole ] and [ fig : nucleus ] below ) .
our goal is to understand the qualitative properties of the short - lived and short - distance ( with respect to @xmath0 ) quantum fluctuations , namely the ones that are probed most efficiently in deep - inelastic scattering experiments in the small-@xmath1 regime , or in observables in proton - proton and proton - nucleus scattering whose cross sections may be related to dipole amplitudes ( see e.g. ref .
@xcite ) .
( a recent general review of high - energy qcd can be found in ref .
@xcite ) .
we shall first describe qualitatively the scattering of two color dipoles and of a dipole off a nucleus , before turning to an analysis of the quantum fluctuations .
we shall eventually review the most striking quantitative prediction derived from our discussion .
our picture relies on the well - known color dipole model @xcite , which describes , in the framework of perturbative quantum chromodynamics , how the quantum state of a hadron builds up from a cascade of dipole splittings . .
And you have already written the first three sentences of the full article: we start with the scattering of two color dipoles ( concretely , e.g. two quark - antiquark pairs ) of respective transverse sizes @xmath2 and @xmath3 with the ordering @xmath4 . at low energy ,
the forward elastic scattering amplitude of the dipoles consists in the exchange of a pair of gluons .
since the dipoles are colorless , this exchange can take place only if their sizes are comparable ( on a logarithmic scale ) , and if the scattering occurs at coinciding impact parameters ..
Please generate the next two sentences of the article | once these conditions are fulfilled , the cross section is parametrically proportional to @xmath5 .
let us go to larger center - of - mass energies @xmath6 by boosting the small dipole to the rapidity @xmath7 . |
8,078 | Suppose that you have an abstract for a scientific paper: a numerical simulation of the oort cloud is used to explain the observed orbital distributions and numbers of jupiter - family and halley - type short - period comets .
comets are given initial orbits with perihelion distances between 5 and 36 au , and evolve under planetary , stellar and galactic perturbations for 4.5 gyr .
this process leads to the formation of an oort cloud ( which we define as the region of semimajor axes @xmath0 au ) , and to a flux of cometary bodies from the oort cloud returning to the planetary region at the present epoch .
the results are consistent with the dynamical characteristics of short - period comets and other observed cometary populations : the near - parabolic flux , centaurs , and high - eccentricity trans - neptunian objects . to achieve this consistency with observations
, the model requires that the number of comets versus initial perihelion distance is concentrated towards the outer planetary region .
moreover , the mean physical lifetime of observable comets in the inner planetary region ( @xmath1 au ) at the present epoch should be an increasing function of the comets initial perihelion distances . virtually all observed halley - type comets and
nearly half of observed jupiter - family comets come from the oort cloud , and initially ( 4.5 gyr ago ) from orbits concentrated near the outer planetary region .
comets that have been in the oort cloud also return to the centaur ( @xmath2 au , @xmath3 au ) and near - neptune high - eccentricity regions .
such objects with perihelia near neptune are hard to discover , but centaurs with characteristics predicted by the model ( e.g. large semimajor axes , above 60 au , or high inclinations , above @xmath4 ) are increasingly being found by observers .
the model provides a unified picture for the origin of jupiter - family and halley - type comets .
it predicts that the mean physical lifetime of all comets in the region @xmath5 au is less than @xmath6200 revolutions .
example.eps gsave newpath 20 20....
And you have already written the first three sentences of the full article: explaining the origin of short - period ( sp ) comets ( periods @xmath7 yr ) is a long - standing problem .
the main difficulty lies in the differences and apparent inconsistency between the respective numbers and orbital distributions of jupiter - family ( jf ) and halley - type ( ht ) comets .
these we classify using the tisserand parameter @xmath8 with respect to jupiter ( carusi et al ..
Please generate the next two sentences of the article | 1987 ) , jf comets having @xmath9 ( and @xmath10 usually below 20 years ) , ht comets having @xmath11 ( and @xmath10 usually between 20 and 200 years ) .
when sp comets are classified this way the number of observed ht comets is found to be less than , or at most comparable to , the number of observed jf comets ( see section [ obs - sp ] below ) . |
8,079 | Suppose that you have an abstract for a scientific paper: on calcule le module des normes universelles pour une reprsentation @xmath0-adique de de rham .
le calcul utilise la thorie des @xmath1-modules ( la formule de rciprocit de cherbonnier - colmez ) et lquation diffrentielle associe une reprsentation de de rham .
we compute the module of universal norms for a de rham @xmath0-adic representation .
the computation uses the theory of @xmath1-modules ( cherbonnier - colmez s reciprocity formula ) and the differential equation attached to a de rham representation . .
And you have already written the first three sentences of the full article: dans tout cet article , @xmath0 est un
nombre premier , @xmath2 est un corps parfait de caractristique @xmath0 , et @xmath3 est une extension finie du corps des fractions @xmath4 de lanneau des vecteurs de witt sur @xmath2 . on se fixe une
clture algbrique @xmath5 de @xmath3 , et on pose @xmath6 ..
Please generate the next two sentences of the article | utilisant lanneau de priodes @xmath0-adiques @xmath7 , fontaine a dfini la notion de reprsentation de _ de rham _ de @xmath8 .
si @xmath9 est une telle reprsentation et si @xmath10 est une extension finie de @xmath3 , on dfinit @xmath11 comme tant lensemble des classes de cohomologie qui dterminent une extension @xmath12 de reprsentations de @xmath13 telle que @xmath14 est une reprsentation de de rham de @xmath13 . on crira |
8,080 | Suppose that you have an abstract for a scientific paper: the classical kummer construction attaches to an abelian surface a k3 surface . as shioda and katsura showed ,
this construction breaks down for supersingular abelian surfaces in characteristic two . replacing supersingular abelian surfaces by the selfproduct of the rational cuspidal curve , and the sign involution by suitable infinitesimal group scheme actions ,
i give the correct kummer - type construction for this situation .
we encounter rational double points of type @xmath0 and @xmath1 , instead of type @xmath2 .
it turns out that the resulting surfaces are supersingular k3 surfaces with artin invariant one and two .
they lie in a 1-dimensional family obtained by simultaneous resolution , which exists after purely inseparable base change . .
And you have already written the first three sentences of the full article: let @xmath3 be an abelian surface over the complex numbers , and @xmath4 the sign involution .
the quotient surface @xmath5 is a normal surface with 16 rational double points of type @xmath2 , whose minimal resolution @xmath6 is a k3 surface .
one also says that @xmath6 is a kummer k3 surface ; they play a fairly central role in the theory of all complex k3 surfaces ..
Please generate the next two sentences of the article | it is easy to see that the kummer construction works in positive characteristics @xmath7 as well .
in contrast , shioda @xcite and katsura @xcite observed that the kummer construction breaks down in characteristic @xmath8 for supersingular abelian surfaces @xmath3 . in this case |
8,081 | Suppose that you have an abstract for a scientific paper: a chandra x - ray observation has detected an unresolved source at the center of the supernova remnant kes 79 . the best single - model fit to the source spectrum is a blackbody with an x - ray luminosity @xmath0(0.3 - 8.0 kev)=@xmath1 ergs s@xmath2 .
there is no evidence for a surrounding pulsar wind nebula .
there are no cataloged counterparts at other wavelengths , but the absorption is high .
the source properties are similar to the central source in cas a even though the kes 79 remnant is considerably older . .
And you have already written the first three sentences of the full article: source 79 in the radio catalog of kesteven ( 1968 ) lies directly in the galactic plane , @xmath3 ne of the galactic center .
it is a moderately large supernova remnant ( snr ) and is sometimes called g33.6 + 0.1 . radio observations ( velusamy , becker & seward 1991 )
show an outer shell , @xmath4 in diameter , which is approximately circular over the sw half of the remnant but with large indentations in the n and e boundaries ..
Please generate the next two sentences of the article | the brightest part of the radio remnant is an interior region with shell - like form .
the southern part of this `` inner shell '' has the highest surface brightness in the remnant . |
8,082 | Suppose that you have an abstract for a scientific paper: we investigate @xmath0-process nucleosynthesis during the magnetohydrodynamical ( mhd ) explosion of supernova in a massive star of 13 @xmath1 .
contrary to the case of the spherical explosion , jet - like explosion due to the combined effects of the rotation and magnetic field lowers the electron fraction significantly inside the layers above the iron core .
we find that the ejected material of low electron fraction responsible for the @xmath0-process comes out from the silicon rich layer of the presupernova model .
this leads to the production up to the third peak in the solar @xmath0-process elements .
we examine whether the fission affects the @xmath0-process paths by using the full nuclear reaction network with both the spontaneous and @xmath2-delayed fission included .
moreover , we pay particular attention how the mass formula affects the @xmath0-process peaks with use of two mass formulae .
it is found that both formulae can reproduce the global abundance pattern up to the third peak though detailed distributions are rather different .
we point out that there are variations in the @xmath0-process nucleosynthesis if the mhd effects play an important role in the supernova explosion . .
And you have already written the first three sentences of the full article: it has been considered that the origin of heavy neutron - rich elements like uranium is mainly due to the @xmath0-process nucleosynthesis that occurs during the supernova explosions and/or neutron star mergers @xcite .
the main issue concerning the @xmath0-process research is to reproduce the three peaks ( @xmath3 80 , 130 , and 195 ) in the abundance pattern for the @xmath0-elements in the solar system . among models of the @xmath0-process , it has been believed that supernovae are the most plausible astrophysical site @xcite .
the explosion is triggered by the gravitational collapse of massive stars of @xmath4(e.g ..
Please generate the next two sentences of the article | * ) . since a proto - neutron star is formed after the explosion , neutron - rich elements seem to be easily ejected by the supernova shock .
unfortunately all realistic numerical simulations concerning the collapse - driven supernovae have failed to explode the outer layer outside the fe - core @xcite . |
8,083 | Suppose that you have an abstract for a scientific paper: we clarify the mechanism of accelerated core formation by large - scale nonlinear flows in subcritical magnetic clouds by finding a semi - analytical formula for the core formation time and describing the physical processes that lead to them .
recent numerical simulations show that nonlinear flows induce rapid ambipolar diffusion that leads to localized supercritical regions that can collapse . here , we employ non - ideal magnetohydrodynamic simulations including ambipolar diffusion for gravitationally stratified sheets threaded by vertical magnetic fields .
one of the horizontal dimensions is eliminated , resulting in a simpler two - dimensional simulation that can clarify the basic process of accelerated core formation .
a parameter study of simulations shows that the core formation time is inversely proportional to the square of the flow speed when the flow speed is greater than the alfvn speed .
we find a semi - analytical formula that explains this numerical result .
the formula also predicts that the core formation time is about three times shorter than that with no turbulence , when the turbulent speed is comparable to the alfvn speed . .
And you have already written the first three sentences of the full article: the theory that the star formation process in a molecular cloud is controlled by the magnetic field and ambipolar diffusion has been studied for many years ( e.g. , * ? ? ?
* ; * ? ? ?
in the theory , the mass - to - flux ratio , which corresponds to the relative strength of gravity and the magnetic field , is an important parameter for the process ..
Please generate the next two sentences of the article | if the mass - to - flux ratio is greater than its critical value ( i.e. , supercritical : gravity dominates the magnetic field ) , the cloud is likely to collapse or fragment on the dynamical timescale .
if the mass - to - flux ratio is less than its critical value ( i.e. , subcritical : the magnetic field dominates gravity ) , the gravitational driven collapse or fragmentation occurs on the ambipolar diffusion timescale ( e.g. , * ? ? ? |
8,084 | Suppose that you have an abstract for a scientific paper: ion mobility spectrometry ( ims ) is a well - known , sensitive and rapid technique to detect dangerous organic compounds .
we propose a system in which a crown type discharge generates a ionic flux that is swept towards an array of collectors by a transverse electric field .
the ions are separated as they enter the cell according to their mobility .
thus , the distribution of the charge collected at the detector assembly constitutes a _ fingerprint _ for each organic compound .
simulations of our cell and experiments were performed for small amount of acetone , ethanol and toluene .
the dependence on the cell parameters of the current and charge versus time of flight was analyzed .
our simulation reproduces only qualitatively the experimental results .
however , a pca statistical analysis of the simulated results shows that such a fingerprint can be used to identify those compounds with certainty . .
And you have already written the first three sentences of the full article: the technique for identification of volatile organic compounds by differences of ion mobility is one of the most efficient techniques applied for detection of explosives , drugs and industrial toxic compounds @xcite .
the detection limit of this technique is found to be of the order of @xmath0 ( ppb ) .
it has a very rapid response time , which makes it very attractive for situations of high control demands ..
Please generate the next two sentences of the article | the ions of the molecule to be identified acquire a velocity under the influence of an external electric field @xmath1 . at the lowest order @xmath2 where @xmath3 is the mobility .
if the field is intense enough it has been reported @xcite that one should go two orders higher ( cubic ) in the field dependence . |
8,085 | Suppose that you have an abstract for a scientific paper: we report quantum monte carlo ( qmc ) , plane - wave density - functional theory ( dft ) , and interatomic pair - potential calculations of the zero - temperature equation of state ( eos ) of solid neon .
we find that the dft eos depends strongly on the choice of exchange - correlation functional , whereas the qmc eos is extremely close to both the experimental eos and the eos obtained using the best semiempirical pair potential in the literature .
this suggests that qmc is able to give an accurate treatment of van der waals forces in real materials , unlike dft .
we calculate the qmc eos up to very high densities , beyond the range of values for which experimental data are currently available . at high densities
the qmc eos is more accurate than the pair - potential eos .
we generate a different pair potential for neon by a direct evaluation of the qmc energy as a function of the separation of an isolated pair of neon atoms .
the resulting pair potential reproduces the eos more accurately than the equivalent potential generated using the coupled - cluster ccsd(t ) method . .
And you have already written the first three sentences of the full article: one of the most important goals of _ ab initio _ computational electronic - structure theory is the development of accurate methods for describing interatomic bonding . quantum monte carlo ( qmc ) techniques are useful in this regard as they can provide a highly accurate description of electron correlation effects .
although qmc methods are computationally expensive , they can be applied to systems which are large enough to model condensed matter . in this study
we have considered solid neon , in which the bonding arises from the competition between short - range repulsion and the van der waals attraction between the atoms ..
Please generate the next two sentences of the article | high - quality experimental measurements of the equation of state ( eos ) exist , which can be used as reference data .
furthermore , various neon pair potentials have been developed using experimental and theoretical data , which can also be used for comparison purposes . |
8,086 | Suppose that you have an abstract for a scientific paper: we discuss the gravitational wave background produced by bouncing models based on a full quantum evolution of a universe filled with a perfect fluid .
using an ontological interpretation for the background wave function allows us to solve the mode equations for the tensorial perturbations , and we find the spectral index as a function of the fluid equation of state . .
And you have already written the first three sentences of the full article: the theory of cosmological perturbations @xcite relies essentially on two assumptions , namely that the background is described by pure classical general relativity ( gr ) , while the perturbations thereof stem from quantum fluctuations , although they are subsequently evolved classically . quite apart from the computational usefulness of this scheme ,
this state of affairs is rather incomplete , and one would expect instead a fully quantum treatment of both the background and the perturbations to be achievable .
in fact , the overwhelming majority of classical backgrounds possess an initial singularity at which the classical theory is expected to break down . in recent years.
Please generate the next two sentences of the article | , many quantum background cosmological models have been proposed , which share the attractive property of exhibiting neither singularities nor horizons @xcite , leading the universe evolution through a bouncing phase due to quantum effects , and a contracting phase from infinity before the bounce .
these new features of the background introduce a new picture for the evolution of cosmological perturbations : vacuum initial conditions may now be imposed when the universe was very big and almost flat , and effects due to the contracting and bouncing phases , which are not present in the standard background model , may change the subsequent evolution of perturbations in the expanding phase . hence |
8,087 | Suppose that you have an abstract for a scientific paper: pressure and temperature dependence of the negative thermal expansion in zn(cn)@xmath0 is fully investigated using molecular dynamics simulations with a built potential model .
the advantage of this study allows us to reproduce the exotic behaviours of the material , including the negative thermal expansion ( nte ) , the reduction of nte with elevated temperature , the pressure enhancement of nte and the pressure - induced softening .
results of the study provide us detailed data to link the properties in the energy space and the real space , giving us insights to understand the properties and the connections between them . .
And you have already written the first three sentences of the full article: negative thermal expansion ( nte ) is a rare and counter - intuitive phenomenon found primarily in low density materials with crystal structures that are networks of linked coordination polyhedra .
the study of these materials is not only of fundamental scientific importance , but also has many technological applications such as aerospace technologies @xcite , optics @xcite , and electronics @xcite .
while much effort has been put into finding new materials and investigating the origin of nte in them , much less attention has been paid to the change in nte behaviour subject to heating and stress , which holds great importance for the possible applications of the material ..
Please generate the next two sentences of the article | for example , due to stresses and heating , problems such as phase transitions of the nte filler and thermal expansion misfit between the nte filler and matrix are always encountered in designed composites with tailored thermal expansion @xcite . in this paper
, we conduct a simulation study of zn(cn)@xmath0 focusing on the pressure and temperature effects on its negative thermal expansion . |
8,088 | Suppose that you have an abstract for a scientific paper: in the study of the small ten - dimensional schwarzschild blackhole , the blackhole to string transition is an important problem . in @xcite
, a possible identification is made between the gross - witten - wadia ( gww ) type third - order large-@xmath0 phase transition in the boundary gauge theory and the string - black hole transition in the bulk . in this paper
, we exhibit the existence of the gww transition by monte carlo simulation in the zero mode bosonic action of the finite - temperature @xmath1 sym theory on @xmath2 . exhibiting
this transition in the truncated but highly non - trivial gauge theory implies that in the vicinity of the critical temperature @xmath3 , the system goes critical , and the fluctuations give rise to universal formulas derived in @xcite .
we also discuss the issue of @xmath4 r - symmetry breaking .
@xmath5 [ cols= " < " , ] + + + monte carlo studies of the gww phase transition + in large-@xmath0 gauge theories takehiro azuma , pallab basu@xmath6 and spenta r. wadia address after dec . 1 , 2007 : university of british columbia , vancouver , canada . ] .
And you have already written the first three sentences of the full article: understanding the string - black hole transition is an important problem in string theory .
the radius of a schwarzschild blackhole becomes smaller with rising temperature and at a certain temperature the blackhole transits to a gas of strings @xcite .
this is a difficult problem to address as it needs a proper understanding of non - perturbative effects in string theory ..
Please generate the next two sentences of the article | the finite temperature of a schwarzschild blackhole breaks supersymmetry and string loop corrections are uncontrolled . in @xcite
it was demonstrated that the problem of the string - blackhole transition can be formulated in a space - time with @xmath7 boundary conditions . |
8,089 | Suppose that you have an abstract for a scientific paper: we present a theory describing the local electronic properties of the perovskite rare earth nickelates materials which have negative charge transfer energies , strong o @xmath0
ni @xmath1 covalence , and breathing mode lattice distortions at the origin of highly studied metal - insulator and antiferromagnetic ordering transitions . utilizing a full orbital , full correlation double cluster approach , we find strong charge fluctuations in agreement with a bond disproportionation interpretation .
the unique double cluster formulation permits the inclusion of necessary orbital degeneracies and coulomb interactions to calculate resonant x - ray spectral responses , with which we find excellent agreement with well - established experimental results .
this previously absent , crucial link between theory and experiment provides validation of the recently proposed bond disproportionation theory , and provides an analysis methodology for spectroscopic studies of engineered phases of nickelates and other high valence transition metal compounds .
the perovskite rare - earth nickelate compounds ( @xmath2nio@xmath3 ) possess a rich phase diagram , exhibiting metal - insulator and antiferromagnetic ordering transitions with temperatures tunable via the rare earth ionic size @xcite .
the transition into the low temperature insulating phase is concomitant with a structural change where alternating nio@xmath4 octahedra are expanded and compressed in a rocksalt - pattern breathing mode distortion ( see fig . [ fig:1](a ) ) . below the nel temperature in this distorted phase ,
the nickelates are e-type antiferromagnets , with an uncommon @xmath5 ordering vector . remarkably , pressure @xcite , strain @xcite , reduced dimensionality @xcite , and the engineering of various heterointerfaces @xcite have all been found to tune the ground state in various ways .
such a diversity of control mechanisms driving fascinating and useful emergent properties has fueled a wealth of interest in the nickelates in recent....
And you have already written the first three sentences of the full article: our model consists of two ni - ligand clusters , roughly equivalent to two nio@xmath4 octahedra , each containing a ni @xmath0 shell , a ni @xmath1 shell , and a ligand shell .
the ligand shell orbitals are defined as linear combinations of the actual oxygen @xmath0 like wannier - orbitals having the same rotation properties as the ni @xmath43 orbitals within the @xmath15 point group used here @xcite .
the general form of our hamiltonian is : @xmath52 where @xmath53 and @xmath54 refer to the short and long bond sites , respectively ( or identical sites when no breathing distortion is present ) and @xmath55 is the part of the hamiltonian that couples the two clusters together . taken separately , @xmath56 and @xmath57 are independent multiplet ligand field theory hamiltonians . for @xmath56 , we have : @xmath58 with , + [ cols= " < , < " , ] the hamiltonian for site @xmath54 is analogous to @xmath56 ..
Please generate the next two sentences of the article | below we list each term in the hamiltonian in more detail .
[ [ section ] ] the onsite energy of the ni @xmath0 core electrons is given as : @xmath59 with @xmath60 labeling the 6 different ni @xmath0 spin - orbitals with @xmath61 and @xmath62 , @xmath63 ( @xmath64 ) the operator creating ( annihilating ) an electron in orbital @xmath60 and @xmath65 defined in terms of @xmath66 , @xmath67 and @xmath68 as @xcite : @xmath69 where @xmath70 is the formal number of @xmath1 electrons per ni ( @xmath71 for the nickelates studied here ) . |
8,090 | Suppose that you have an abstract for a scientific paper: a world wide web interface to a monte carlo validation and tuning facility is described .
the aim of the package is to allow rapid and reproducible comparisons to be made between detailed measurements at high - energy physics colliders and general physics simulation packages .
the package includes a relational database , a java servlet query and display facility , and clean interfaces to simulation packages and their parameters .
` ucl / hep 2002 - 04 ` + ` october ` ` 2002 ` j. m. butterworth + s. butterworth + + university college london + gower st .
london wc1e
6bt + england _ pacs : _
+ _ keywords : monte carlo simulation ; qcd final states ; jets ; database ; java ; mysql ; www _ .
And you have already written the first three sentences of the full article: we present a web - based facility for the comparison of measurements of hadronic final states and the expectations of physics calculations and simulations .
the physics motivation is discussed .
then follows an outline of the design and technology used in the jetweb server ..
Please generate the next two sentences of the article | section 4 contains a user guide to the server , as presented on the web , while sections 5 and 6 cover the implementation of the server with a view to further development and future plans .
particle physics experiments at high - energy accelerators have provided a wealth of data on the final state in electron - positron , lepton - proton and proton - antiproton interactions . |
8,091 | Suppose that you have an abstract for a scientific paper: `` sticky '' motion in mixed phase space of high dimensional conservative systems is difficult to detect and to characterize .
its effect on quasi - regular motion is quantified here with four different measures , related to the distribution of the finite time lyapunov exponents .
we study systematically conservative maps from the uncoupled two - dimensional case up to coupled maps of dimension @xmath0 .
we find sticky motion in all unstable directions above a threshold @xmath1 of the nonlinearity parameter @xmath2 for the high dimensional cases @xmath3 .
moreover , as @xmath2 increases we can clearly identify the transition from quasiregular to totally chaotic motion which occurs simultaneously in all unstable directions .
results show that all four statistical measures sensitively probe sticky motion in high dimensional systems .
finite time lyapunov exponent distribution , stickiness , chaos , high dimensions .
And you have already written the first three sentences of the full article: the dynamics of conservative systems consists of different types of motion , from regular over quasi - regular to chaotic , depending on the perturbation parameter .
usually , in @xmath4 dimensional conservative systems regular islands ( kolmogorov - arnold - moser kam tori ) can break as the perturbation parameter increases , and chaotic trajectories may coexist with regular islands @xcite .
this regime is called quasiregular ..
Please generate the next two sentences of the article | chaotic trajectories may be trapped around stable islands creating `` sticky '' motion ( for a review see @xcite ) . in such cases
the dynamics in phase space can be very structured and the motion is non - ergodic . |
8,092 | Suppose that you have an abstract for a scientific paper: we recently put forth a new fundamental lattice hamiltonian based on an underlying picture of electrons and deuterons as elementary dirac particles . within this model
there appears a term in which lattice vibrations are coupled to internal nuclear transitions .
this is interesting as it has the potential to provide a connection between experiment and models that describe coherent energy transfer between two - level systems and an oscillator . in this work
we describe a calculation of the coupling matrix element in the case of the deuteron based on the old empirical hamada - johnston model for the nucleon - nucleon interaction .
the triplet s and d states of the the deuteron in the rest frame couples to a singlet p state through this new interaction .
the singlet p state in this calculation is a virtual state with an energy of 125 mev , and a coupling matrix element for @xmath0-directed motion given by @xmath1 . .
And you have already written the first three sentences of the full article: we recently obtained a new hamiltonian for a lattice which includes interactions with internal nuclear degrees of freedom @xcite .
we started with a dirac model for electrons and for nucleons on equal footing , then allowed the nuclei to be described by a finite basis expansion , and finally developed an approximation appropriate for low nuclear velocity .
our original motivation for this was to obtain a model capable of describing the mass shift associated with excited nuclear states in a configuration interaction calculation ..
Please generate the next two sentences of the article | however , the new model unexpectedly contains a new coupling term which provides for a direct interaction between lattice vibrations and nuclear transitions . on the face of it
, this new interaction term looks like it should allow for the strongly - coupled transitions that we have sought @xcite in connection with the generalized lossy spin - boson models @xcite that we proposed to account for some of the anomalies ( such as excess heat @xcite and collimated x - ray emission @xcite ) that have been reported in experiments in recent years . |
8,093 | Suppose that you have an abstract for a scientific paper: radio relic sources in galaxy clusters are often described as the remnants of powerful radio galaxies . here
we develop a model for the evolution of such relics after the jets cease to supply energy to the lobes .
this includes the treatment of a relic overpressured with respect to its gaseous surroundings even after the jets switch off .
we also determine the radio emission of relics for a large variety of assumptions .
we take into account the evolution of the strength of the magnetic field during the phase of relativistic particle injection into the lobes .
the resulting spectra show mild steepening at around 1ghz but avoid any exponential spectral cut - offs .
the model calculations are used to fit the observed spectra of seven radio relics .
the quality of the fits is excellent for _ all _ models discussed .
unfortunately , this implies that it is virtually impossible to determine any of the important source parameters from the observed radio emission alone .
galaxies : active galaxies : jets intergalactic medium radio continuum : galaxies .
And you have already written the first three sentences of the full article: diffuse radio emission without an apparent host galaxy is found in an increasing number of clusters of galaxies ( e.g. * ? ? ?
* ; * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
these objects can roughly be divided into radio halos close to the cluster centre which appear comparatively smooth in radio images and radio relics with a far more distorted and knotty appearance . |
8,094 | Suppose that you have an abstract for a scientific paper: we define refined invariants which `` count '' nodal curves in sufficiently ample linear systems on surfaces , conjecture that their generating function is multiplicative , and conjecture explicit formulas in the case of k3 and abelian surfaces .
we also give a refinement of the caporaso - harris recursion , and conjecture that it produces the same invariants in the sufficiently ample setting .
the refined recursion specializes at @xmath0 to the itenberg - kharlamov - shustin recursion for welschinger invariants .
we find similar interactions between refined invariants of individual curves and real invariants of their versal families . .
And you have already written the first three sentences of the full article: given a general elliptic fibration @xmath1 , we learn by computing @xmath2 that there must be 24 nodal fibers . for more general irreducible curve classes on a k3 , yau and
zaslow @xcite argued that taking the euler characteristic of the relative compactified jacobian would again yield the number of maximally degenerate fibers ; the arguments were clarified by beauville @xcite and by fantechi , van straten , and the first author @xcite . for more general families of curves ,
similar arguments may be made in terms of the relative hilbert schemes of points ..
Please generate the next two sentences of the article | let @xmath3 be a family of reduced planar curves of arithmetic genus @xmath4 , and let @xmath5 } \to b$ ] be the relative hilbert schemes .
certain string - theoretic ideas of gopakumar and vafa @xcite motivate the consideration of the following series , and the following change of variables : @xmath6 } ) = \sum_{i=0}^\infty n^i_{\cc / b } \cdot \left(\frac{q}{(1-q)^2}\right)^{i+1-g}\ ] ] in the case of a single curve @xmath7 , we write simply @xmath8 . |
8,095 | Suppose that you have an abstract for a scientific paper: this work investigates the preferred environment of local luminous ir galaxies ( lirgs ) in terms of the host halos that they inhabit , and in comparison to a control galaxy sample .
the lirgs are drawn from the iras point source catalogue redshift survey ( pscz ) , while the control sample is drawn from the 2mass redshift survey ( 2mrs ) .
a friends - of - friends algorithm was run on the 2mrs sample to identify galaxies living in the same dark matter halos and the pscz galaxies were then associated with these identified halos .
we show that the relative probability of finding local lirgs with respect to 2mass galaxies is largest in approximately group size halos ( @xmath0 ) , and declines both in the cluster regime and in smaller halos .
this confirms , using a different technique than in previous work , that local lirgs are indeed more abundant in group environments than elsewhere .
we also find a trend between the @xmath1 values of lirgs and their location within their host dark matter halos , such that the average location of lirgs with high ir luminosity is closer to the halo centre than for low ir luminosity galaxies . moreover
, this trend does not seem to depend on halo mass .
+ infrared : galaxies - galaxies : star formation - galaxies : evolution - galaxies : haloes . .
And you have already written the first three sentences of the full article: the extreme cases of star formation ( sf ) in the universe are exhibited by classes of galaxies such as luminous infrared galaxies ( lirgs ; defined as galaxies with ir luminosities of @xmath2 ) and ultra - luminous ir galaxies ( ulirgs ; @xmath3 ) and as a result , it is impossible to discuss the phenomenon of extreme sf in the universe without the mention of lirgs and ulirgs .
these galaxies are good laboratories to attempt to understand the nature and detailed mechanism of these exotic forms of sf and they have been the focus of many studies ( see e.g. * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * and references therein ) .
it has long been clear that very strong star forming galaxies in the local universe are related to mergers and interactions ( e.g. * ? ? ? * and references therein ) . |
8,096 | Suppose that you have an abstract for a scientific paper: image segmentation is to separate an image into distinct homogeneous regions belonging to different objects .
it is an essential step in image analysis and computer vision .
this paper compares some segmentation technologies and attempts to find an automated way to better determine the parameters for image segmentation , especially the connectivity value of @xmath0 in @xmath0-connected segmentation .
based on the theories of the maximum entropy method and otsu s minimum variance method , we propose:(1)maximum entropy connectedness determination : a method that uses maximum entropy to determine the best @xmath0 value in @xmath0-connected segmentation , and ( 2 ) minimum variance connectedness determination : a method that uses the principle of minimum variance to determine @xmath0 value . applying these optimization techniques in real images ,
the experimental results have shown great promise in the development of the new methods . in the end , we extend the above method to more general case in order to compare it with the famous mumford - shah method that uses variational principle and geometric measure . .
And you have already written the first three sentences of the full article: image segmentation is the basic approach in image processing and computer vision @xcite . it is used to locate special regions and then extract information from them .
image segmentation is used to partition an image into different components or objects and is an essential procedure for image preprocessing , object detection and extraction , and object tracking .
image segmentation is also related to edge detection . even though there is no unified theory for image segmentation ,.
Please generate the next two sentences of the article | some practical methods have been studied over the years such as thresholding , edge based segmentation , region growing , clustering ( unsupervised classification ) , and split - and - merge segmentation , to name a few .
@xmath0-connected segmentation is a technique in the category of region growing segmentation . |
8,097 | Suppose that you have an abstract for a scientific paper: the associated production of a higgs boson and a top - quark pair , @xmath0 , in proton - proton collisions is addressed in this paper for a center of mass energy of 13 tev at the lhc .
dileptonic final states of @xmath1 events with two oppositely charged leptons and four jets from the decays @xmath2 , @xmath3 and @xmath4 , are used .
signal events , generated with madgraph5amc@nlo , are fully reconstructed by applying a kinematic fit .
new angular distributions of the decay products as well as angular asymmetries are explored in order to improve discrimination of @xmath0 signal events over the dominant irreducible background contribution , @xmath5 . even after the full kinematic fit reconstruction of the events , the proposed angular distributions and asymmetries are still quite different in the @xmath6 signal and the dominant background ( @xmath7 ) . .
And you have already written the first three sentences of the full article: on july 4th 2012 the atlas @xcite and cms @xcite collaborations announced the discovery of a scalar particle at cern s large hadron collider ( lhc ) .
this new particle with a mass of about @xmath8 gev was later identified as the higgs boson , responsible for the generation of all particle masses through the mechanism of spontaneous symmetry breaking @xcite .
so far , the measured properties of the higgs boson have shown a remarkable consistency with those predicted by the standard model ( sm ) of particle physics ..
Please generate the next two sentences of the article | nevertheless , it is by now clear that the sm can not explain all the observed physical phenomena , as for instance it fails to provide a candidate for dark matter or a means to explain the matter anti - matter asymmetry in the universe .
however , as more data is being accumulated and analysed at the lhc , it becomes increasingly clear that any new physics theory has to resemble very much the sm at the electroweak scale . in the first run , |
8,098 | Suppose that you have an abstract for a scientific paper: the non - markovian decoherence of quantum and classical correlations is analytically obtained when two qubits are asymmetrically subjected to the bit flip channel and phase flip channel . for one class of initial mixed states , quantum correlations quantified by quantum discord decay synchronously with classical correlations .
the discovery that the decaying rates of quantum and classical correlations suddenly change at the characteristic time is physically interpreted by the distance from quantum state to the closest classical states . in a large time interval ,
quantum correlations are greater than classical correlations .
the quantum and classical correlations can be preserved over a longer period of time via the kernel characterizing the environment memory effects .
pacs : 03.65.ta , 03.67.mn , 75.10.jm , 75.10.pq keywords : decoherence , quantum discord , non - markovian environments interaction .
And you have already written the first three sentences of the full article: the great obstacle to the practical tasks of quantum information processing is the destruction of quantum correlations arising from the inevitable interactions of the systems of interest with their environments @xcite .
the fundamental quantum correlations are contained in nonclassical states .
it is known that the entanglement measure can only quantify quantum correlations for inseparable states ..
Please generate the next two sentences of the article | recently , a large amount of experimental and theoretical studies have discovered that quantum discord @xcite is a more general measure of nonclassical correlations in comparison with the entanglement @xcite .
quantum correlation introduced by henderson and vedral @xcite is identical to the quantum discord defined by ollivier and zurek @xcite in the case of two qubits @xcite . |
8,099 | Suppose that you have an abstract for a scientific paper: the present work is designed to explore the evolution of helium - core white dwarf ( he wd ) stars for the case of metallicities much lower than the solar metallicity ( @xmath0= 0.001 and @xmath0= 0.0002 ) .
evolution is followed in a self - consistent way with the predictions of detailed and new non - grey model atmospheres , time - dependent element diffusion and the history of the white dwarf progenitor .
reliable initial models for low mass he wds are obtained by applying mass loss rates to a 1 m@xmath1 stellar model in such a way that the stellar radius remains close to the roche lobe radius . the loss of angular momentun caused by gravitational wave emission and magnetic stellar wind braking are considered .
model atmospheres , based on a detailed treatment of the microphysics entering the wd atmosphere ( such as the formalism of hummer - mihalas to deal with non - ideal effects ) as well as hydrogen line and pseudo - continuum opacities , enable us to provide accurate colours and magnitudes at both early and advanced evolutionary stages .
we find that most of our evolutionary sequences experience several episodes of hydrogen thermonuclear flashes .
in particular , the lower the metallicity , the larger the minimum stellar mass for the occurrence of flashes induced by cno cycle reactions .
the existence of a mass threshold for the occurrence of diffusion - induced cno flashes leads to a marked dichotomy in the age of our models .
another finding of this study is that our he wd models experience unstable hydrogen burning via pp nuclear reactions at late cooling stages as a result of hydrogen chemically diffusing inwards .
such pp flashes take place in models with very low metal content .
we also find that models experiencing cno flashes exhibit a pronounced turn - off in most of their colours at m@xmath2 16.finally , colour - magnitude diagrams for our models are presented and compared with recent observational data of he wd candidates in the globular clusters ngc 6397 and 47....
And you have already written the first three sentences of the full article: low - mass helium - core white dwarf stars ( he wds ) are thought to be the result of the evolution of certain close binary systems .
mass - transfer episodes in binary systems are required to form low mass he wds because an isolated star would need a timescale much longer than the present age of the universe to reach a wd configuration with a helium - rich interior .
low mass wds have been detected in large surveys ( bragaglia et al . 1990 ; bergeron , saffer & liebert 1992 ; bragaglia , renzini & bergeron 1995 ; saffer , livio & yungelson 1998 ) and represent an appreciable fraction of the total population of wd stars . since he wds began to be found in numerous binary configurations ( marsh 1995 ; marsh , dhillon & duck 1995 ; lundgren et al ..
Please generate the next two sentences of the article | 1996 ; moran , marsh & bragaglia 1997 ; orosz et al .
1999 ; van kerkwijk et al . |
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