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9,200 | Suppose that you have an abstract for a scientific paper: the ccd johnson @xmath0 and cousins @xmath1 photometric magnitudes are determined for 20 stars in the field of grb 000926 .
they are used to calibrate the present @xmath2 as well as published @xmath3 photometric magnitudes of the grb 000926 afterglow .
optical light curves of the afterglow emission are obtained in @xmath4 and @xmath2 passbands .
they show a steepening of the flux decay as expected of an anisotropic fireball losing collimation with the fall of the bulk lorentz factor .
we derive the early and late time flux decay constants as @xmath5 and @xmath6 respectively . steepening in the flux decay seems to have started around 1.7 days after the burst .
negligible galactic but relatively large intrinsic extinction amounting @xmath7 0.03 and [email protected] mag respectively are derived in the direction of grb 000926 .
the value of the spectral index in the optical near - infrared region is @xmath9 .
the determination of the redshift @xmath10 indicates a cosmological origin of the burst at a luminosity distance of 16.6 gpc .
the observed fluence in the energy range 20100 kev indicates , if isotropic , the release of @xmath11 ergs of energy . attributing the observed break in the light curve at 1.7 days to the onset of sideways expansion of a jet - like ejecta
, we infer an initial jet opening angle of @xmath120.14 radian .
this indicates a large anisotropy in the original emission and the amount of released energy is reduced by a factor of @xmath12 100 relative to the isotropic value , which can be understood in terms of the currently popular stellar death models . *
grb 000926 and its optical afterglow : another evidence for non - isotropic emission * * r. sagar@xmath13 , s. b. pandey@xmath13 , v. mohan@xmath13 , d. bhattacharya@xmath14 and a. j. castro - tirado@xmath15 * + + _ @xmath14raman research institute , bangalore 560 080 ,
india _ + _ @xmath15iaa - csic , p.o .
box 03004 , e-18080 , granada , spain _ keywords : photometry grb afterglow
flux decay ....
And you have already written the first three sentences of the full article: multiwavelength follow - up of gamma - ray burst ( grb ) afterglows has revolutionized grb astronomy in recent years , yielding a wealth of information about the nature and origin of grbs ( cf .
klose 2000 ; kulkarni et al .
2000 ; galama 2000 ; castro - tirado et al ..
Please generate the next two sentences of the article | 1999 and references therein ) .
one of the most important clues to the origin of grbs is the total amount of energy released in the event . |
9,201 | Suppose that you have an abstract for a scientific paper: we investigate the formation and evolutionary sequences of galactic intermediate- and low - mass x - ray binaries ( i / lmxbs ) by combining binary population synthesis ( bps ) and detailed stellar evolutionary calculations . using an updated bps code
we compute the evolution of massive binaries that leads to the formation of incipient i / lmxbs , and present their distribution in the initial donor mass vs. initial orbital period diagram .
we then follow the evolution of i / lmxbs until the formation of binary millisecond pulsars ( bmsps ) .
we find that the birthrate of the i / lmxb population is in the range of @xmath0 , compatible with that of bmsps which are thought to descend from i / lmxbs .
we show that during the evolution of i / lmxbs they are likely to be observed as relatively compact binaries with orbital periods @xmath1 1 day and donor masses @xmath2 .
the resultant bmsps have orbital periods ranging from less than 1 day to a few hundred days .
these features are consistent with observations of lmxbs and bmsps .
we also confirm the discrepancies between theoretical predications and observations mentioned in the literature , that is , the theoretical average mass transfer rates ( @xmath3yr@xmath4 ) of lmxbs are considerably lower than observed , and the number of bmsps with orbital periods @xmath5 day is severely underestimated .
these discrepancies imply that something is missing in the modeling of lmxbs , which is likely to be related to the mechanisms of the orbital angular momentum loss . .
And you have already written the first three sentences of the full article: low - mass x - ray binaries ( lmxbs ) consist of an accreting compact star , either a black hole or a neutron star ( ns ) and a low - mass ( @xmath6 ) donor star , in which mass transfer proceeds via roche - lobe overflow ( rlof ) .
there are about 200 lmxbs in the galaxy @xcite .
the formation of black hole lmxbs is still a controversial topic ( * ? ? ?.
Please generate the next two sentences of the article | * for a review ) , and will be discussed elsewhere . here
we focus on the formation and evolution of lmxbs with a ns . |
9,202 | Suppose that you have an abstract for a scientific paper: this paper studies the interference channel with a cognitive relay ( iccr ) under delayed feedback .
three types of delayed feedback are studied : delayed channel state information at the transmitter ( csit ) , delayed output feedback , and delayed shannon feedback .
outer bounds are derived for the dof region of the two - user multiple - input multiple - output ( mimo ) iccr with delayed feedback as well as without feedback . for the single - input single - output ( siso ) scenario ,
optimal schemes are proposed based on retrospective interference alignment .
it is shown that while a cognitive relay _ without _ feedback can not extend the sum - dof beyond @xmath0 in the two - user siso interference channel , delayed feedback in the same scenario can extend the sum - dof to @xmath1 .
for the mimo case , achievable schemes are obtained via extensions of retrospective interference alignment , leading to dof regions that meet the respective upper bounds . .
And you have already written the first three sentences of the full article: cognitive radio is a subject of intense interest motivated by its potential for better usage of spectral resources . to explore the fundamental limits of such channels , and to make use of powerful techniques developed for capacity of channels with state known at transmitter , some information - theoretic cognitive models allow a cognitive node to possess non - causal knowledge of data originating elsewhere .
interestingly , in the recent years applications have emerged where knowledge of another nodes data prior to transmission is indeed practically viable .
examples include heterogeneous networks or coordinated networks , where some base stations can possess knowledge of the messages of other base stations by coordination ..
Please generate the next two sentences of the article | other examples involve layered cell structures , where macro base stations can know the messages of pico base stations that are routed from the macro base station over backhaul links .
such heterogeneous or coordinated networks can be modeled by interference channels with cognitive transmitters @xcite . |
9,203 | Suppose that you have an abstract for a scientific paper: the sea quark content of the @xmath0 baryon is investigated using light - cone baryon - meson fluctuation model suggested by brodsky and ma .
it is found that the @xmath0 sea is flavour asymmetric ( @xmath1 ) and quark - antiquark asymmetric ( @xmath2 ) .
our prediction for the flavour asymmetry , @xmath1 , is significantly different from the @xmath3 prediction ( @xmath4 ) , while our prediction for the @xmath5-@xmath6 asymmetry is consistent with the @xmath3 prediction .
pacs numbers : 11.30.hv ; 14.20.-c keywords : flavour asymmetry ; baryon sea ; baryon - meson fluctuation ; @xmath3 16.5 cm 23.5 cm -1.0 cm -0.2 cm -0.2 cm # 1#2#3#4#1 # 2 ( # 4 ) # 3 * the flavour asymmetry and quark - antiquark asymmetry in the @xmath0-sea * institute of fundamental sciences , massey university , private bag 11 222 , palmerston north , new zealand the nucleon sea exhibits two interesting properties : flavour asymmetry @xcite and quark - antiquark asymmetry @xcite . while there have been many studies of the nucleon sea from both experiment ( see e. g. @xcite ) and theory ( see e. g. @xcite and references therein ) , the studies of the sea distributions of the other baryons in the baryon octet predicted by the @xmath3 quark model are very few .
it is of interest to know whether the sea of the other members of the baryon octet has the same properties ( flavour asymmetry and quark - antiquark asymmetry ) as the nucleon sea .
also , through the study of the quark sea of the other members of the baryon octet , we can improve our understanding of the structure of the baryons and the non - perturbative properties of qcd .
alberg _
et al . _
@xcite pointed out that the valence and sea quark distributions of the @xmath7 may exhibit large deviations from the @xmath3 predictions , and these parton distributions could be obtained from drell - yan experiments using charged hyperon beams on proton and deuteron targets .
alberg , falter , and henley @xcite studied the flavour asymmetry in the....
And you have already written the first three sentences of the full article: this work was partially supported by the massey postdoctoral foundation , new zealand .
99 p. amaudraz et al . , ; m. arneodo et al . , ; m. arneodo et al . , .
a. baldit et al . , na51 collaboration , ..
Please generate the next two sentences of the article | e. a. hawker et al . ,
e866/nusea collaboration , . |
9,204 | Suppose that you have an abstract for a scientific paper: let @xmath0 be a connected oriented graph .
a set @xmath1 is convex in @xmath0 if , for every pair of vertices @xmath2 , the vertex set of every @xmath3-geodesic , ( @xmath3 shortest directed path ) and every @xmath4-geodesic in @xmath0 is contained in @xmath5 .
the convexity number , @xmath6 , of a non - trivial oriented graph , @xmath0 , is the maximum cardinality of a proper convex set of @xmath0 .
the strong convexity spectrum of the graph @xmath7 , @xmath8 , is the set @xmath9 . in this paper
we prove that the problem of determining the convexity number of an oriented graph is @xmath10-complete , even for bipartite oriented graphs of arbitrary large girth , extending previous known results for graphs .
we also determine @xmath11 , for every pair of integers @xmath12 .
convexity number , convex set , spectrum , oriented graph , grid 05c 12 , 05c20 .
And you have already written the first three sentences of the full article: graphs considered in the paper are finite , without loops or multiple edges . in a graph @xmath13 ,
@xmath14 and @xmath15 ( @xmath16 and @xmath17 ) denote the vertex set and the edge set of @xmath7 , respectively . for undefined concepts and notation
we refer the reader to @xcite . for two vertices @xmath18 and @xmath19 in a graph @xmath7 , a @xmath20-geodesic is a shortest path between @xmath18 and @xmath19 ..
Please generate the next two sentences of the article | a set @xmath5 of vertices of @xmath7 is convex if the vertices of every @xmath20-geodesic is contained in @xmath5 for every @xmath21 . according to duchet ,
convexity in graphs has been studied since the early seventies , when abstract convexity was studied in different contexts ( @xcite is an outdated , but very nice , survey on the subject ) . |
9,205 | Suppose that you have an abstract for a scientific paper: the measurement of @xmath0+jet events with a direct photon in coincidence with an energetic parton can provide unique insights into the propagation and fragmentation of the parton in the presence of the hot and dense medium created in heavy - ion collisions .
one way to explore these effects is the study of azimuthal correlations between the direct photon and hadrons produced in the fragmentation .
we present azimuthal correlations between photons with a transverse momentum of more than 10gev and charged hadrons with a transverse momentum of more than 2gev in au+au collisions at @xmath1 that have been measured with the star detector at rhic .
the separation of correlations with direct photons and photons from hadronic decays will be discussed . .
And you have already written the first three sentences of the full article: photon - tagged jets in heavy ion collisions provide the ideal framework to study the interaction of energetic partons traversing a strongly interacting , hot and dense medium like the quark - gluon plasma @xcite .
annihilation ( @xmath2 ) or compton scattering ( @xmath3 ) results in @xmath4jet events with a prompt photon , which does not interact strongly , and a parton , which is subject to energy loss in the medium and subsequent fragmentation into a jet of hadrons @xcite .
as the photon escapes the medium without interactions , the analysis of these events will provide the best possible determination of the initial kinematics of the parton , and therefore all modifications of the jet can be attributed to the interaction of the parton or the emerging jet with the medium @xcite ..
Please generate the next two sentences of the article | azimuthal correlations with prompt photons as trigger particles reflect these interactions and provide information about the energy loss mechanism during the propagation of the parton through the medium @xcite .
the data presented here has been taken by the star experiment during a long au+au run at top energy of @xmath5 at the rhic collider . |
9,206 | Suppose that you have an abstract for a scientific paper: with its cometary appearance and a reflection nebula near its edge facing some bright orion stars , the lynd s cloud l1616 shows ample evidence for being affected by one or more of these massive stars . to estimate its mass and star formation efficiency as well as to determine if it is gravitationally bound , we mapped this cloud in j=1@xmath00 transitions of @xmath1co and @xmath2co .
it is found that the distribution of the emission in the line _ wings _ show clear evidence for substantial mass motions . also , the `` virial '' mass of the cloud is found to be five times the actual cloud mass determined from the @xmath2co column density map . it is argued that this cloud has abnormally high star formation efficiency and is possibly disintegrating .
the morphology and the location of the cloud indicate that it is being affected by the star @xmath3 orionis which is also possibly responsible for the cloud s unusual star formation efficiency . over a range of values of the relevant parameters ,
the star is found to quantitatively satisfy the requirements of being the cause of the observed characteristics of the cloud .
= 0.2 cm i keywords : stars : formation ; ism : clouds ; ism : individual : l1616 ; reflection nebulae .
running title : cloud l1616 proofs to : b.ramesh .
And you have already written the first three sentences of the full article: massive stars affect the structure and the evolution of the clouds around them substantially . globules and clouds with bright rims and cometary appearance
are found in the vicinity of many nearby ob associations e.g. vela ( gum nebula ; sridharan 1992 ) , orion ( bally et al . 1991 ) , cepheus ( indrani & sridharan 1994 ) and rosette ( patel , xie & goldsmith 1993 ) .
in addition to affecting the morphology , these stars also accelerate the globules and possibly induce star formation in them as well ..
Please generate the next two sentences of the article | there are many clouds in the orion complex which show evidence of being affected by the nearby stars .
lynd s dark cloud l1616 with its cometary appearance is one among them . |
9,207 | Suppose that you have an abstract for a scientific paper: bailey et al . ( 2016 ) and gomes et al . ( 2016 ) recently suggested that the 6 degree misalignment between the sun s rotational equator and the orbital plane of the major planets may be produced by the forcing from the hypothetical planet nine on an inclined orbit .
here we present a simple but accurate calculation of the effect , which provides a clear description of how the sun s spin orientation depends on the property of planet nine in this scenario . .
And you have already written the first three sentences of the full article: batygin & brown ( 2016 ) showed that a hypothetical planet ( `` planet nine '' ) in the outer solar system can explain several otherwise intriguing orbital properties of distant kbos .
recently , bailey et al .
( 2016 ) and gomes et al ..
Please generate the next two sentences of the article | ( 2016 ) suggested that planet nine , which has an inclined orbit relative to the orbital plane of the major planets , may also be responsible for generating the @xmath0 solar obliquity ( the misalignment angle between the sun s rotational equator and the solar system invariant plane ) .
these studies were based on somewhat formal treatments and involved numerical integrations . in this note |
9,208 | Suppose that you have an abstract for a scientific paper: entropy , under a variety of names , has long been used as a measure of diversity in ecology , as well as in genetics , economics and other fields .
there is a spectrum of viewpoints on diversity , indexed by a real parameter @xmath0 giving greater or lesser importance to rare species .
leinster and cobbold @xcite proposed a one - parameter family of diversity measures taking into account both this variation and the varying similarities between species .
because of this latter feature , diversity is not maximized by the uniform distribution on species .
so it is natural to ask : which distributions maximize diversity , and what is its maximum value ? + in principle , both answers depend on @xmath0 , but our main theorem is that neither does .
thus , there is a single distribution that maximizes diversity from all viewpoints simultaneously , and any list of species has an unambiguous maximum diversity value .
furthermore , the maximizing distribution(s ) can be computed in finite time , and any distribution maximizing diversity from some particular viewpoint @xmath1 actually maximizes diversity for all @xmath0 .
+ although we phrase our results in ecological terms , they apply very widely , with applications in graph theory and metric geometry . .
And you have already written the first three sentences of the full article: for decades , ecologists have used entropy - like quantities as measures of biological diversity .
the basic premise is that given a biological community or ecosystem containing @xmath2 species in proportions @xmath3 , the entropy of the probability distribution @xmath4 indicates the extent to which the community is balanced or ` diverse ' .
shannon entropy itself is often used ; so too are many variants , as we shall see ..
Please generate the next two sentences of the article | but almost all of them share the property that for a fixed number @xmath2 of species , the entropy is maximized by the uniform distribution @xmath5 .
however , there is a growing appreciation that this crude model of a biological community is too far from reality , in that it takes no notice of the varying similarities between species . |
9,209 | Suppose that you have an abstract for a scientific paper: we describe the coupling of moving atoms to a one dimensional photonic waveguide in the regime where the atomic velocities are comparable to the effective speed of light .
such conditions could be achieved , for example , in photonic crystals or coupled resonator arrays , where the maximal photonic group velocity is significantly reduced compared to free space . in this case
the interplay between a velocity - induced directionality and the emergence of effective divergencies in the photonic density of states gives rise to a range of novel phenomena and non - perturbative effects in the emission of photons and the resulting dipole - dipole interactions between moving atoms .
we show that apart from potential nanophotonic implementations , rydberg atoms flying above a coupled array of superconducting microwave resonators provide a versatile platform for exploring this new regime of pseudo - relativistic atom - light interactions under accessible experimental conditions .
the radiation of charged particles moving close to the speed of light is a long - studied problem of classical electrodynamics @xcite with practical relevance for accelerator physics or the development of intense x - ray sources @xcite . in contrast , the coupling of neutral atoms and molecules to classical or quantized fields is usually investigated under opposite conditions , where particle velocities are low and mainly affect the emission and absorption of photons via a linear doppler shift .
this effect , however , is the basis for laser cooling @xcite and successive atom trapping techniques @xcite , which enabled the study of strong light - matter interactions even at the single photon level @xcite . based on the same techniques , it has recently become possible to interface cold atoms with one dimensional ( 1d ) waveguides @xcite and photonic crystal structures @xcite ,
inside which the propagation velocity of photons can be significantly reduced @xcite .
this opens up new possibilities for exploring an....
And you have already written the first three sentences of the full article: in this section we discuss in more detail the derivation and the validity of the effective continuum model given in eq .
( 2 ) in the main text . for this analysis
we assume that the motion of atoms is described by classical trajectories @xmath135 , which is well justified for the parameter regime considered in this work . under this assumption the kinetic term appearing in eq ..
Please generate the next two sentences of the article | ( 1 ) in the main text is constant and the dynamics of the atoms can be reduced to their internal degrees of freedom . to achieve slow - light conditions we consider a periodically modulated waveguide with lattice constant @xmath0 and total length @xmath136 .
the hamiltonian describing the coupling of the two - level atoms and the 1d field in the waveguide can then be written in the general form @xmath137 @xmath138.\ ] ] by assuming periodic boundary conditions the field operator is given by @xmath139 where @xmath140 are bosonic annihilation operators obeying @xmath141=\delta_{bb ' } \delta_{kk'}$ ] and @xmath142 are bloch waves with band index @xmath143 and wavevector @xmath144 $ ] , @xmath145 . |
9,210 | Suppose that you have an abstract for a scientific paper: we calculate the van der waals friction between two semi - infinite solids in normal relative motion and find a drastic difference in comparison with the parallel relative motion .
the case of the good conductors is investigated in details both within the local optic approximation , and using a non - local optic dielectric approach .
we show that the friction may increase by many order of magnitude when the surfaces are covered by adsorbates , or can support low - frequency surface plasmons . in this case
the friction is determined by resonant photon tunneling between adsorbate vibrational modes , or surface plasmon modes .
the theory is compared to atomic force microscope experimental data . .
And you have already written the first three sentences of the full article: a great deal of attention has been devoted to non - contact friction between nanostructures , including , for example , the frictional drag force between two - dimensional quantum wells @xcite , and the friction force between an atomic force microscope tip and a substrate @xcite . in non - contact friction
the bodies are separated by a potential barrier thick enough to prevent electrons or other particles with a finite rest mass from tunneling across it , but allowing interaction via the long - range electromagnetic field , which is always present in the gap between bodies .
the presence of inhomogeneous tip - sample electric fields is difficult to avoid , even under the best experimental conditions @xcite ..
Please generate the next two sentences of the article | for example , even if both the tip and the sample were metallic single crystals , the tip would still have corners present and more than one crystallographic plane exposed .
the presence of atomic steps , adsorbates , and other defects will also contribute to the inhomogeneous electric field . |
9,211 | Suppose that you have an abstract for a scientific paper: we investigate the effect induced by the kaluza - klein ( kk ) graviton in the @xmath0 production in the framework of the large extra dimensions ( led ) model at both the cern large hadron collider ( lhc ) and the international linear collider ( ilc ) .
the integrated cross sections and various kinematic distributions in the led model are presented and compared with those in the standard model .
the results show that the contributions from kk - graviton exchange remarkably affect the observables of the triple gauge boson ( @xmath0 ) production processes at both the ilc and lhc , particularly either in the high transverse momentum region or in the central rapidity region .
we also find that the relative led discrepancy for the @xmath0 production at the lhc is generally larger than that at the ilc due to the additional led contribution via @xmath1 fusion subprocess and the kk - graviton exchanging resonant effect induced by the continuous large colliding energy in @xmath2 collision .
we conclude that the @xmath3 and @xmath4 productions at the lhc could have the distinct advantage over at the ilc from the aspect of effectively exploring the led signal in measuring @xmath0 production .
= 0.32 in addtoresetequationsection .
And you have already written the first three sentences of the full article: the cern large hadron collider ( lhc ) and the upcoming international linear collider ( ilc ) are expected to perform precision tests of the standard model ( sm ) and explore the new physics at the tev scale @xcite .
the large extra dimensions ( led ) model is one of the scenarios beyond the sm which are proposed to solve the hierarchy problem @xcite .
the led model has only one fundamental scale , @xmath5 tev , and it may induce predictable collider phenomena at both the lhc and the ilc . up to now , many works on both the virtual kaluza - klein ( kk ) graviton exchange and the real kk - graviton production have been presented ; for example , the @xmath6 and @xmath7 processes were studied in the led model in refs.@xcite-@xcite ..
Please generate the next two sentences of the article | in fact , the triple gauge boson ( tgb ) production processes are sensitive to the quartic gauge couplings ( qgcs ) and thus related to the electroweak symmetry breaking mechanism @xcite .
any deviation from the sm prediction hints at the existence of new physics , such as the higgsless or extra dimension signals @xcite . in discriminating physics beyond the sm |
9,212 | Suppose that you have an abstract for a scientific paper: we report a comparative raman spectroscopic study of the quasi - one - dimensional charge - density - wave systems a@xmath0moo@xmath1 ( a = k , rb ) .
the temperature and polarization dependent experiments reveal charge - coupled vibrational raman features .
the strongly temperature - dependent collective amplitudon mode in both materials differ by about 3 @xmath2 , thus revealing the role of alkali atom .
we discus the observed vibrational features in terms of charge - density - wave ground state accompanied by change in the crystal symmetry .
a frequency - kink in some modes seen in k@xmath0moo@xmath1 between t = 80 k and 100 k supports the first - order lock - in transition , unlike rb@xmath0moo@xmath1 .
the unusually sharp raman lines(limited by the instrumental response ) at very low temperatures and their temperature evolution suggests that the decay of the low energy phonons is strongly influenced by the presence of the temperature dependent charge density wave gap . .
And you have already written the first three sentences of the full article: quasi - one dimensional ( 1d ) metals are interesting materials because of their tendency to undergo a phase - transition inevitably due to the inherent instability called the peierls instability @xcite .
this instability , originating from the electron - phonon interaction leads to a metal - insulator transition at reduced temperature , where the insulating state may be characterized by a lattice deformation in conjunction with a charge modulation and the opening of a single particle excitation gap in the electronic spectrum.@xcite one of the striking features of these materials are their unusual non - linear electrical conduction properties @xcite , which arises due to the collective motion of the charge - density wave ( cdw ) .
along with the conventional single particle excitations , these materials also have collective excitations , _ viz . _ ,.
Please generate the next two sentences of the article | amplitudons and phasons , which dominate the low energy physical properties @xcite .
the raman active collective amplitudon mode , _ |
9,213 | Suppose that you have an abstract for a scientific paper: the study of quantum quenches in integrable systems has significantly advanced with the introduction of the quench action method , a versatile analytical approach to non - equilibrium dynamics .
however , its application is limited to those cases where the overlaps between the initial state and the eigenstates of the hamiltonian governing the time evolution are known exactly .
conversely , in this work we consider physically interesting initial states for which such overlaps are still unknown . in particular
, we focus on different classes of product states in spin-@xmath0 and spin-@xmath1 integrable chains , such as tilted ferromagnets and antiferromagnets .
we get around the missing overlaps by following a recent approach based on the knowledge of complete sets of quasi - local charges .
this allows us to provide a closed - form analytical characterization of the effective stationary state reached at long times after the quench , through the bethe ansatz distributions of particles and holes .
we compute the asymptotic value of local correlations and check our predictions against numerical data . .
And you have already written the first three sentences of the full article: the complexity in the study of the non - equilibrium dynamics in isolated many - body quantum systems is at first sight overwhelming . at the same time
, many interesting questions naturally arise when a system is brought out of equilibrium , for example regarding the nature of quantum decoherence or relaxation processes . in the past decade , these issues have been at the center of a fruitful theoretical research activity , partially motivated by the experimental achievements in the physics of ultra - cold atoms , such as the possibility to realize highly isolated and controlled many - body quantum systems with reduced effective dimensionality @xcite . in particular , due to the exact solvability of several one - dimensional quantum systems , they represent an ideal framework where exact theoretical results can be compared with experimental data .
many studies have already shown that integrable one - dimensional many - body hamiltonians can be experimentally engineered and their non - equilibrium dynamics probed in exquisite detail @xcite ..
Please generate the next two sentences of the article | arguably , the simplest protocol to bring a system out of equilibrium is that of a quantum quench @xcite : a well - defined initial state ( usually the ground state of some hamiltonian @xmath2 ) is prepared at time @xmath3 and subsequently time evolved with some hamiltonian @xmath4 . after the quench , it is expected that an extended system should act as an infinite thermal bath on its own finite subsystems and , accordingly , local properties should relax to stationary values described by a gibbs ensemble . for a generic ( i.e. non - integrable ) model
, this picture turns out to be correct and the time - dependent local correlations indeed approach thermal stationary values @xcite . a different behavior is observed in integrable systems . in this case , local correlations still approach stationary values but these are not in general given by a thermal ensemble . |
9,214 | Suppose that you have an abstract for a scientific paper: the dynamics of adaptation is difficult to predict because it is highly stochastic even in large populations .
the uncertainty emerges from number fluctuations , called genetic drift , arising in the small number of particularly fit individuals of the population .
random genetic drift in this evolutionary vanguard also limits the speed of adaptation , which diverges in deterministic models that ignore these chance effects .
several approaches have been developed to analyze the crucial role of noise on the _ expected _ dynamics of adaptation , including the mean fitness of the entire population , or the fate of newly arising beneficial deleterious mutations .
however , very little is known about how genetic drift causes fluctuations to emerge on the population level , including fitness distribution variations and speed variations . yet , these phenomena control the replicability of experimental evolution experiments and are key to a truly predictive understanding of evolutionary processes . here , we develop an exact approach to these emergent fluctuations by a combination of computational and analytical methods . we show , analytically , that the infinite hierarchy of moment equations can be closed at any arbitrary order by a suitable choice of a dynamical constraint . this constraint regulates ( rather than fixes ) the population size , accounting for resource limitations .
the resulting linear equations , which can be accurately solved numerically , exhibit fluctuation - induced terms that amplify short - distance correlations and suppress long - distance ones .
importantly , by accounting for the dynamics of sub - populations , we provide a systematic route to key population genetic quantities , such as fixation probabilities and decay rates of the genetic diversity .
we demonstrate that , for some key quantities , asymptotic formulae can be derived . while it is natural to consider the process of adaptation as a branching random walk ( in fitness space ) subject to a constraint ( due to....
And you have already written the first three sentences of the full article: darwinian adaptation spontaneously emerges from the processes of mutation , reproduction and competition , and these features need to be mirrored in any model of adaptation . in models , spontaneous mutations can be represented by a stochastic jump process in a `` fitness space '' .
reproduction is naturally described by a branching process by which individuals give birth at certain fitness - dependent rates @xcite . in combination , reproduction and mutations
thus generate a branching random walk @xcite , which by itself would lead to diverging population sizes . to avoid this unrealistic outcome , models of adaptation also encode a constraint on population sizes to account for the competition for finite resources ..
Please generate the next two sentences of the article | the resulting process is a branching random walk subject to a global constraint , which we now frame mathematically .
the state of the population at time @xmath0 is described by a function @xmath1 representing the number density of individuals with fitness @xmath2 . in this context |
9,215 | Suppose that you have an abstract for a scientific paper: the bohmian quantum approach is implemented to analyze the financial markets . in this approach
, there is a wave function that leads to a quantum potential .
this potential can explain the relevance and entanglements of the agent s behaviors with the past .
the light is shed by considering the relevance of the market conditions with the previous market conditions enabling the conversion of the local concepts to the global ones .
we have shown that there are two potential limits for each market .
in essence , these potential limits act as a boundary which limits the return values inside it . by estimating the difference between these two limits in each market
, it is found that the quantum potentials of the return time series in different time scales , possess a scaling behavior .
the slopes of the scaling behaviors in mature , emerging and commodity markets show different patterns .
the emerge market having a slope greater than 0.5 , has a higher value compared to the corresponding values for the mature and commodity markets which is less than 0.5 .
the cut - off observed in the curve of the commodity market indicates the threshold for the efficiency of the global effects . while before the cut - off , local effects in the market are dominant , as in the case of the mature markets .
the findings could prove adequate for investors in different markets to invest in different time horizons . .
And you have already written the first three sentences of the full article: in the mainstream economy , the cornerstone for mathematical modeling of financial markets is the efficient market hypothesis ( emh)@xcite . a market is said to be efficient if all the existing information has affected the prices and any new random information influences the asset prices randomly @xcite .
the emh hypothesis is based on some assumptions such as rationality of the investors .
empirical studies have shown that the real prices do not completely follow a random walk which is the criterion of emh @xcite ..
Please generate the next two sentences of the article | some methods such as behavioral models , try to explain the real behavior of asset prices . on the other hand ,
one of the behavioral aspects of markets is the entanglement of their conditions that lead to converting the local concepts to the global ones . |
9,216 | Suppose that you have an abstract for a scientific paper: we report on a concept inventory for special relativity : the development process , data analysis methods , and results from an introductory relativity class .
the relativity concept inventory tests understanding of kinematic relativistic concepts .
an unusual feature is confidence testing for each question .
this can provide additional information ; for example high confidence correlated with incorrect answers suggests a misconception .
a novel aspect of our data analysis is the use of monte carlo simulations to determine the significance of correlations .
this approach is particularly useful for small sample sizes , such as ours .
our results include a gender bias that was not present in other assessment , similar to that reported for the force concept inventory . .
And you have already written the first three sentences of the full article: concept inventories are used to assess learning in many areas of physics education @xcite . when used to determine the effectiveness of educational innovations they may contribute to the teaching development cycle . since the literature on special relativity education research does not include a concept inventory we have developed the relativity concept inventory ( rci ) , available from the supplemental appendix to this paper .
special relativity is interesting in a physics education research context because of its combination of deeply challenging concepts and simple mathematics .
this is in contrast with quantum mechanics , which has a more complex mathematical structure . nevertheless , the amount of physics education research on special relativity is small @xcite ..
Please generate the next two sentences of the article | the rci has been validated by feedback from discipline experts and its validity and reliability established by standard methods @xcite .
these include the self - referential statistics of classical test theory , and benchmarking against traditional assessment such as homework and an exam . |
9,217 | Suppose that you have an abstract for a scientific paper: the binder cumulant ( bc ) has been widely used for locating the phase transition point accurately in systems with thermal noise . in systems with quenched disorder
, the bc may show subtle finite - size effects due to large sample - to - sample fluctuations .
we study the globally coupled kuramoto model of interacting limit - cycle oscillators with random natural frequencies and find an anomalous dip in the bc near the transition .
we show that the dip is related to non - self - averageness of the order parameter at the transition .
alternative definitions of the bc , which do not show any anomalous behavior regardless of the existence of non - self - averageness , are proposed .
the characterization of phase transitions relies mainly on the singularity structure of physical quantities at the transition , which can be quantified by critical exponent values . in numerical efforts ,
the accuracy of the estimated exponents heavily depends on the precision of locating the phase transition point . in the case of most thermal systems , the binder cumulant ( bc )
is widely believed to provide one of the most accurate tools for estimating the transition point @xcite . the critical bc value at the transition is also believed to be universal , even though there is still controversy over its universality @xcite . in some complex systems @xcite
, the bc shows an anomalous negative dip in finite systems , which represents a rugged landscape ( multi - peak structure ) in the probability distribution function ( pdf ) of the order parameter .
great care is required in analyzing numerical data to see whether the dip will vanish in the thermodynamic limit .
if it does , the negative dips in the finite systems can be attributed to long - living metastable states .
otherwise , a nonvanishing negative dip usually implies that the transition is not continuous , but is of the first order . in systems with quenched disorder
, the disorder fluctuation may also generate an anomalous negative dip....
And you have already written the first three sentences of the full article: this work was supported by research funds of chonbuk national university ( 2004 ) and the korea research foundation grant ( moehrd ) ( r14 - 2002 - 059 - 01000 - 0 ) ( hh ) , and by the research grants council of the hksar under project 2017/03p and hong kong baptist university under project frg/01 - 02/ii-65 ( lht ) .
k. binder , in _ finite - size scaling and numerical simulation of statistical systems _ , edited by v. privman ( world scientific , singapore , 1990 ) , p. 173 ; k. binder and d. w. heermann , _ monte carlo simulation in statistical physics .
an introduction _ , 3rd ed ..
Please generate the next two sentences of the article | ( springer , berlin , 1997 ) .
y. kuramoto , in _ proceedings of the international symposium on mathematical problems in theoretical physics _ , edited by h. araki ( springer - verlag , new york , 1975 ) ; y. kuramoto , _ chemical oscillations , waves , and turbulence _ |
9,218 | Suppose that you have an abstract for a scientific paper: atomically resolved imaging and spectroscopic characteristics of graphene grown by chemical vapor deposition ( cvd ) on copper are investigated by means of scanning tunneling microscopy and spectroscopy ( stm / sts ) . for cvd - grown graphene remaining on the copper substrate , the monolayer carbon structures exhibit ripples and appear strongly strained , with different regions exhibiting different lattice structures and electronic density of states ( dos ) .
in particular , ridges appear along the boundaries of different lattice structures , which exhibit excess charging effects . additionally , the large and non - uniform strain induces pseudo - magnetic field up to @xmath0 tesla , as manifested by the dos peaks at quantized energies that correspond to pseudo - magnetic field - induced integer and fractional landau levels .
in contrast , for graphene transferred from copper to sio@xmath1 substrates after the cvd growth , the average strain on the whole diminishes , so do the corresponding charging effects and pseudo - magnetic fields except for sample areas near topological defects .
these findings suggest feasible nano - scale `` strain engineering '' of the electronic states of graphene by proper design of the substrates and growth conditions .
scanning tunneling microscopy , scanning tunneling spectroscopies , chemical vapor deposition , quantum effects , surface structure , morphology , roughness , and topography , carbon .
And you have already written the first three sentences of the full article: the superior physical properties of graphene @xcite and its compatibility with two - dimensional lithographic processes have stimulated intense research of graphene - based electronics for `` beyond si - cmos '' technology @xcite .
one of the major challenges for realizing the graphene - based beyond si - cmos technology is the fabrication of high - quality large - area graphene sheets and the retention of superior electronic characteristics of graphene .
the apparent degradation of carrier mobility and significant variations in the electronic characteristics when graphene comes in contact with various dielectrics @xcite suggest significant susceptibility of the single - layer carbon atoms to the surrounding environment . on the other hand.
Please generate the next two sentences of the article | , the strong susceptibility of graphene to external influences also provides opportunities for engineering unique properties of graphene .
for instance , it has been theoretically proposed that a designed strain aligned along three main crystallographic directions induces strong gauge fields that effectively act as a uniform magnetic field on the dirac electrons @xcite . in particular , for a finite doping level , the quantizing field results in an insulating bulk and a pair of counter - circulating edge states , which is similar to the case of topological insulators @xcite . |
9,219 | Suppose that you have an abstract for a scientific paper: a correlation of x - ray source and h@xmath0 emission - line object catalogues in the small magellanic cloud ( smc ) shows that more than two thirds of the optically identified be stars in be / x - ray binaries are found as emission - line objects in the catalogues . on the basis of this result
we propose up to 25 x - ray sources mainly from recent rosat catalogues as new be / x - ray binaries and give their likely optical counterparts . also for the five yet unidentified x - ray pulsars in the smc we propose emission - line stars as counterparts .
this more than doubles the number of known high mass x - ray binary systems in this nearby galaxy .
the spatial distribution of the new candidates is similar to that of the already identified be / x - ray binaries with a strong concentration along the smc main body and some systems in the eastern wing .
the new candidates contribute mainly to the low - luminosity end of the x - ray luminosity distribution of be / x - ray binaries .
a comparison with the luminosity distribution in the milky way reveals no significant differences at the high - luminosity end and the large number of low - luminosity systems in the smc suggests that many such systems may still be undetected in the galaxy
. the overall ratio of known be to ob supergiant x - ray binaries in the smc is an order of magnitude larger than in the galaxy , however , might show spatial variations . while in the eastern wing the ratio is comparable to that in the galaxy no supergiant x - ray binary
is currently known in the main body of the smc .
possible explanations include a different star formation history over the last @xmath1 my . .
And you have already written the first three sentences of the full article: in high mass x - ray binaries ( hmxbs ) a neutron star or black hole orbits a massive early - type star and accretes matter either via roche - lobe overflow or from the stellar wind which powers the x - ray emission ( for recent reviews see nagase 1989 , white et al .
1995 , bildsten et al .
one divides the class of hmxbs according to the stellar type of the mass donor star into supergiant x - ray binaries with luminosity class i - ii ob star and be / x - ray binaries with luminosity class iii - iv be star companions ..
Please generate the next two sentences of the article | be / x - ray binaries form the larger sub - group of hmxbs .
balmer emission lines in the optical spectrum and a characteristic infrared excess are attributed to the presence of circum - stellar material , probably forming a disk in the equatorial plane of the be star . |
9,220 | Suppose that you have an abstract for a scientific paper: we consider a spaceborne gravitational wave ( gw ) detector formed by three spacecraft in a linear array , coherently exchanging laser beams and using the data combinations of time - delay interferometry ( tdi ) .
we previously showed how the measured time series of doppler shifts in the six one - way laser links between spacecraft pairs in a general unequal - arm triangular configuration can be combined , using tdi , to exactly cancel the otherwise overwhelming phase noise of the lasers while retaining sensitivity to gws . here
we apply tdi , unfolding the general triangular configuration , to the special case of a linear array of three spacecraft .
we show that such an array ( `` syzygy '' ) has , compared with an equilateral triangle gw detector of the same scale , degraded ( but non - zero ) sensitivity at low - frequencies ( f @xmath0 c/(array size ) ) but similar peak and high - frequency sensitivities to gws .
we develop the gw and noise responses , noting that in this geometrical case only one tdi combination is gw - sensitive showing a relatively simple 6-pulse response to an incident gw burst .
sensitivity curves are presented for syzygys having various arm - lengths .
a number of technical simplifications result from the linear configuration .
these include : only one faceted ( e.g. cubical ) proof mass per spacecraft , intra - spacecraft laser metrology needed only at the central spacecraft , placement in an appropriate orbit can reduce doppler drifts so that no laser beam modulation is required for ultra - stable oscillator noise calibration , and little or no time - dependent articulation of the telescopes to maintain pointing .
because syzygy s sensitivity falls off more sharply at low - frequency than that of an equilateral triangular array , it may be most useful for gw observations in the band between those of ground - based interferometers ( @xmath1 hz ) and lisa ( @xmath2 hz ) . syzygy with @xmath3 1 light - second scale could , for the same instrumental assumptions as....
And you have already written the first three sentences of the full article: when coherent optical or microwave wave trains are interchanged between three or more freely orbiting spacecraft , and phase or frequency differences of all incoming and outgoing beams recorded , there is a closure that allows subsequent elimination of all source fluctuations ( `` laser noises '' ) and so achieves sensitivity to propagating gravitational waves at much lower levels set by secondary noises . in doing this
, the precise propagation times between sources and readout locations enter the data reduction algorithms , but equality of arm lengths is not necessary .
we have called this scheme `` time delay interferometry '' or tdi , @xcite and subsequently analyzed several configurations and data types needed for further elimination of the most serious secondary phase noise sources , _ viz . _ those due to spacecraft non - geodesic motion ( `` optical bench noise '' ) and especially to fluctuations of the ultra - stable local oscillators , or frequency standards , used in fringe tracking ( `` uso noise '' ) @xcite ..
Please generate the next two sentences of the article | fringe tracking is necessary when the lasers in the configuration have widely differing frequencies , and/or when the configuration does not move rigidly so that emitted and received signals are doppler shifted during slow spacecraft separation changes . the lisa space gravitational wave antenna will use tdi , and is to be roughly equilateral , which maximizes the overall response to low frequency gravitational waves over a wide band . reduction of secondary noise , and simplicity of system architecture , nevertheless suggest consideration also of other schemes ; here we consider the most extreme possible application of tdi , _ viz . _ to a linear orbiting array , or , in astronomical terms , three spacecraft flying in syzygy .
we have previously considered a linear array , or parallel beam interferometric detector of gravitational waves , in work showing that with multiple bounces a split antiparallel laser beam will amplify a gravitational wave signal while laser fluctuations are cancelled conventionally by precise control of equal arm lengths @xcite . |
9,221 | Suppose that you have an abstract for a scientific paper: we report an extensive theoretical study of the protonated water dimer @xmath0 ( zundel ion ) by means of the highly correlated variational monte carlo and lattice regularized monte carlo approaches .
this system represents the simplest model for proton transfer ( pt ) and a correct description of its properties is essential in order to understand the pt mechanism in more complex acqueous systems .
our jastrow correlated agp wave function ensures an accurate treatment of electron correlations . exploiting the advantages of contracting the primitive basis set over atomic hybrid orbitals , we are able to limit dramatically the number of variational parameters with a systematic control on the numerical precision , a crucial ingredient in order to simulate larger systems . we investigate the energetics and geometrical properties of the @xmath0 as a function of the oxygen - oxygen distance , taken as reaction coordinate . in both cases ,
our qmc results are found in excellent agreement with state - of - the - art coupled cluster ccsd(t ) techniques .
calculations on proton transfer static barriers and dissociation energies display the same agreement .
a comparison with density functional theory results in the pbe approximation points out the crucial role of electron correlations for a correct description of the pt in the dimer .
finally , the ability of our method to resolve very tiny energy differences ( @xmath1 kcal / mol ) at which the proton hopping takes place and the corresponding structural variations optimized directly in the vmc framework is also proven .
our approach combines these features with a @xmath2-@xmath3 scaling with number of particles .
this value is favorable with respect to other highly correlated _ ab initio _ approaches and it allows the simulation of more realistic pt models ; a test calculation on a larger protonated water cluster is hence carried out .
the qmc approach used here represents a promising candidate to provide the first high - level _ ab - initio _....
And you have already written the first three sentences of the full article: water is a key element for life , but nevertheless its properties arising from its unique structure are not fully understood yet .
a large amount of published works explored the several phases of water and many efforts have been spent by the scientific community in order to match experimental findings with theoretical predictions . from the chemical and biological points of view , a deep understanding of the properties of acqueous systems and therefore of liquid water is fundamental .
over the past years , the structural and dynamical properties of liquid water have been investigated relying on the state - of - the - art molecular dynamics techniques such as empirical force field methods @xcite and _ ab initio _ molecular dynamics ( aimd ) ..
Please generate the next two sentences of the article | the latter methodology has been extensively employed for the study of liquid water @xcite as well as acqueous solution of biological interest @xcite ; within , this technique , the atomic force fields required as input by any molecular dynamics simulation are constructed from _ ab initio _ potential energy surfaces ( pess ) and therefore directly derived from first principles electronic structure calculations .
working out an accurate pes for liquid water has been a longstanding challenge in the scientific community ; this is due mainly to the absence of an _ ab initio _ method able to develop a reliable pes that describes breaking and formation of hydrogen bonds ; other issues are related to difficulties in simulating weak interaction and polarization effects in the network of polar molecules . |
9,222 | Suppose that you have an abstract for a scientific paper: we have investigated beating patterns in shubnikov - de haas oscillations for hgte / hg@xmath0cd@xmath1te(001 ) quantum wells with electron densities of 2 to 3 @xmath2 @xmath3 . up to 12 beating nodes have been observed at magnetic fields between 0.9 and 6 t. zero magnetic field spin - orbit splitting energies up to @xmath4 mev have been directly determined from the node positions as well as from the intersection of self - consistently calculated landau levels .
these values , which exceed the thermal broadening of landau levels , @xmath5 , at room temperature , are in good agreement with rashba spin - orbit splitting energies calculated by means of an @xmath6 kane model .
the experimental shubnikov - de haas oscillations are also in good agreement with numerical simulations based on this model . .
And you have already written the first three sentences of the full article: in general , level splitting due to structure inversion asymmetry , sia , known as rashba s - o splitting@xcite is inversely proportional to the energy gap .
s - o coupling is zero for s - like conduction bands and strong in p - like hole states .
however , mixing of the conduction subbands with the valence subbands increases with decreasing energy gap ..
Please generate the next two sentences of the article | it has been shown that electrons in narrow gap heterostructures based on hgte@xcite , exhibit strong rashba s - o coupling .
in addition to the small energy gap in hgte quantum wells , qw s , another important factor contributing to the large magnitude of the rashba s - o coupling is the inverted band structure of hgte qw s with well widths greater than 6 nm , in which the first conduction band has heavy hole character.@xcite for possible applications in spintronics,@xcite the rashba effect has recently been investigated in a number of narrow gap iii - v systems@xcite in which typical values of the rashba s - o splitting energy , @xmath7 , are 3 to 5 mev . |
9,223 | Suppose that you have an abstract for a scientific paper: we describe iso observations of the obscured asymptotic giant branch ( agb ) star iras04496@xmath06958 in the large magellanic cloud ( lmc ) .
this star has been classified as a carbon star .
our new isocam cvf spectra show that it is the first carbon star with silicate dust known outside of the milky way .
the existence of this object , and the fact that it is one of the highest luminosity agb stars in the lmc , provide important information for theoretical models of agb evolution and understanding the origin of silicate carbon stars . .
And you have already written the first three sentences of the full article: asymptotic giant branch ( agb ) carbon stars are produced following @xmath1 dredge - up in thermally pulsing stars ( e.g. iben & renzini 1983 ) .
the star changes from oxygen- to carbon - rich when sufficient carbon has been mixed - in with the stellar mantle to yield an abundance ratio c / o@xmath2 .
the chemistry of the dust in the circumstellar envelope ( cse ) changes accordingly ..
Please generate the next two sentences of the article | the change occurs at smaller core - mass or lower luminosity for lower metallicity stars .
clear evidence for this comes from observations of clusters in the large magellanic cloud ( lmc ) that contain both carbon and m - type stars ( lloyd evans 1984 ; marigo et al . |
9,224 | Suppose that you have an abstract for a scientific paper: we report an improved fabrication scheme for carbon based nanospintronic devices and demonstrate the necessity for a careful data analysis to investigate the fundamental physical mechanisms leading to magnetoresistance .
the processing with a low - density polymer and an optimised recipe allows us to improve the electrical , magnetic and structural quality of ferromagnetic permalloy contacts on lateral carbon nanotube ( cnt ) quantum dot spin valve devices , with comparable results for thermal and sputter deposition of the material .
we show that spintronic nanostructures require an extended data analysis , since the magnetisation can affect all characteristic parameters of the conductance features and lead to seemingly anomalous spin transport .
in addition , we report measurements on cnt quantum dot spin valves that seem not to be compatible with the orthodox theories for spin transport in such structures . .
And you have already written the first three sentences of the full article: merging the exquisite tunability of electronic nanostructures with ferromagnetic materials in nanospintronic devices bears great potential for applications and fundamental investigations .
electronic devices using the electron spin in magnetic field sensing are very successful , for example in hard disks of computers .
however , to use the electron spin directly , for example in a spin - transistor @xcite or as quantum bits @xcite , it is necessary to fabricate nanostructures with the required long coherence times and electrical tunability ..
Please generate the next two sentences of the article | carbon nanotubes ( cnts ) and graphene are in principle ideally suited for spintronic devices due to the large intrinsic coherence times , tunable electron density and large maximum current densities .
early electrically tunable spin valves on carbon nanotubes @xcite , or nonlocal spin - accumulation experiments on graphene @xcite demonstrate the great potential of carbon based nanostructures . to obtain an electrically tunable spin signal , |
9,225 | Suppose that you have an abstract for a scientific paper: the work is motivated by a result of manin in @xcite , which relates the arakelov green function on a compact riemann surface to configurations of geodesics in a 3-dimensional hyperbolic handlebody with schottky uniformization , having the riemann surface as conformal boundary at infinity .
a natural question is to what extent the result of manin can be generalized to cases where , instead of dealing with a single riemann surface , one has several riemann surfaces whose union is the boundary of a hyperbolic 3-manifold , uniformized no longer by a schottky group , but by a fuchsian , quasi - fuchsian , or more general kleinian group .
we have considered this question in this work and obtained several partial results that contribute towards constructing an analog of manin s result in this more general context . .
And you have already written the first three sentences of the full article: lets consider that @xmath0 is a compact riemann surface .
then we can define a green s function with respect to a metric and a divisor on @xmath0 .
suppose that @xmath1 is a hyperbolic 3 - manifold with infinite volume and having compact riemann surfaces @xmath2 as its conformal boundaries at infinity . also choose a geometry on @xmath1 which bears a metric of constant negative curvature ..
Please generate the next two sentences of the article | the main new results of this paper express the green s functions on each @xmath3 in terms of the length of some certain geodesics in @xmath1 .
manin has done this provided that @xmath1 has one boundary component ( i.e. n=1 ) and is uniformized by a schottky group in @xcite . in this work |
9,226 | Suppose that you have an abstract for a scientific paper: assuming the majorana nature of massive neutrinos , we generalize the friedberg - lee neutrino mass model to include cp violation in the neutrino mass matrix @xmath0 . the most general case with all the free parameters of @xmath0 being
complex is discussed .
we show that a favorable neutrino mixing pattern ( with @xmath1 , @xmath2 , @xmath3 and @xmath4 ) can naturally be derived from @xmath0 , if it has an approximate or softly - broken @xmath5-@xmath6 symmetry .
we also point out a different way to obtain the nearly tri - bimaximal neutrino mixing pattern with @xmath7 and non - vanishing majorana phases . recently
, a novel neutrino mass model has been proposed by friedberg and lee ( fl).@xcite the neutrino mass operator in the fl model is simply given by @xmath8 where the parameters @xmath9 , @xmath10 , @xmath11 and @xmath12 are all assumed to be _ real _ , and the charged - lepton mass matrix is taken to be diagonal .
a salient feature of @xmath13 is its partial gauge - like symmetry ; i.e. , its @xmath9 , @xmath10 and @xmath11 terms are invariant under the transformation @xmath14 ( for @xmath15 ) with @xmath16 being a space - time independent constant element of the grassmann algebra.@xcite from eq .
( 1 ) , one can directly write down the neutrino mass matrix : @xmath17 two interesting features can be inferred from the diagonalization of @xmath0 .
first , the neutrino mass matrix takes a magic form,@xcite in which the sums of rows and columns are all equal to @xmath12 .
the unitary matrix used to diagonalize @xmath0 must have one eigenvector with three equal components @xmath18 .
second , when @xmath19 holds , it is very easy to check that the neutrino mass operator @xmath13 has the exact @xmath5-@xmath6 symmetry ( i.e. , @xmath13 is invariant under the exchange of @xmath5 and @xmath6 indices).@xcite in addition , one may consider to remove one degree of freedom from @xmath13 or @xmath0 ( for instance , by setting @xmath20).@xcite to include cp or t violation into the fl model ,....
And you have already written the first three sentences of the full article: this work is supported in part by the national natural science foundation of china .
see , e.g. , t. fukuyama and h. nishiura , hep - ph/9702253 ; r. n. mohapatra and s. nussinov , _ phys .
d _ * 60 * , 013002 ( 1999 ) ; z. z. xing , _ phys ..
Please generate the next two sentences of the article | d _ * 61 * , 057301 ( 2000 ) ; _ phys .
d _ * 64 * , 093013 ( 2001 ) ; _ phys . |
9,227 | Suppose that you have an abstract for a scientific paper: more and more claims of having detected wimp dark matter are being put forward . some are discussed here , stressing the importance of exploiting distinctive signatures to ascertain their wimp origin .
the best signals for wimp discovery are characterized by special features that make them recognizable as due to wimps and nothing else . sometimes , however , a single feature , although accountable for in theoretical models , may not be enough to make sure that we have detected wimps .
this is because the theory of wimps and their distribution in the galaxy is still very uncertain , and allows for many possibilities .
what are needed are _ experimental _ verifications of the claimed signals , either by discovering _
unmistakable _ features , or by detecting several kinds of signals that can all be explained by the _
same _ wimp model .
one of the most intriguing results to come out of recent cosmological observations is that about 90% of the mass of the universe is not made of protons , neutrons , electrons , or any other known particle , but of something unknown that does not shine .
discovering the composition of this so - called non - baryonic dark matter is one of the big challenges of modern physics and cosmology .
proposals as to the nature of non - baryonic dark matter do not lack .
is it made of axions ( neutral particles suggested to explain the smallness of cp violation in the strong interactions ) ? or is it made of wimps ( weakly interacting massive particles that arise naturally in extensions of the standard model of particle physics , such as supersymmetry ) ?
or is non - baryonic dark matter made of something else , or a combination of all that ? following the tradition of experimental science , the way to find out the nature of non - baryonic dark matter is to detect its constituents , either directly by recording their collisions with a detector , or indirectly by observing products of their reactions in planets , stars , or galaxies .
the last ten years have....
And you have already written the first three sentences of the full article: the existence of non - baryonic dark matter is supported by varied cosmological measurements . of great relevance
are the values of the matter and energy densities of the universe at the present time .
these densities can be determined by means of several cosmological data : the temperature fluctuations in the cosmic microwave background ( cmb ) , the distance - luminosity relation for supernovas , the distribution of galaxies on large scales , the abundance of light elements ( primordial nucleosynthesis ) , etc ..
Please generate the next two sentences of the article | the density values so obtained are compatible with all current astrophysical and cosmological observations , from the internal motions of galaxies and galaxy clusters to studies of weak gravitational lensing .
@xcite finds the following values @xcite for the current matter and energy densities , @xmath0 , in units of @xmath1 g/@xmath2 ( i.e. 18.79 yg / m@xmath3 or 1.689 nj / m@xmath4 ) : * -0.5em a negligible density in relativistic particles ( `` radiation '' ; e.g. , the cmb photons contribute only @xmath5 ) ; * -0.5em @xmath6 in a smoothly distributed component ( dark energy ) ; * -0.5em @xmath7 in non - relativistic particles ( `` matter '' ) , of which * * -1em @xmath8 in protons and neutrons ( baryons ) , * * -1em @xmath9 ( 95% cl ) in non - baryonic hot dark matter , * * -1em @xmath10 in non - baryonic cold dark matter . |
9,228 | Suppose that you have an abstract for a scientific paper: supernova remnants ( snrs ) are one of the most energetic astrophysical events and are thought to be the dominant source of galactic cosmic rays ( crs ) .
a recent report on observations from the fermi satellite has shown a signature of pion decay in the gamma - ray spectra of snrs .
this provides strong evidence that high - energy protons are accelerated in snrs .
the actual gamma - ray emission from pion decay should depend on the diffusion of crs in the interstellar medium . in order to quantitatively analyse the diffusion of high - energy crs from acceleration sites , we have performed test particle numerical simulations of cr protons using a three - dimensional magnetohydrodynamics ( mhd ) simulation of an interstellar medium swept - up by a blast wave .
we analyse the diffusion of crs at a length scale of order a few pc in our simulated snr , and find the diffusion of crs is precisely described by a bohm diffusion , which is required for efficient acceleration at least for particles with energies above 30 tev for a realistic interstellar medium .
although we find the possibility of a superdiffusive process ( travel distance @xmath0 ) in our simulations , its effect on cr diffusion at the length scale of the turbulence in the snr is limited .
bohm diffusion , galactic cosmic rays , superdiffusion , supernova remnant .
And you have already written the first three sentences of the full article: supernova remnants ( snrs ) have long been believed to be the source of hadronic galactic cosmic rays ( gcrs ) up to energies of the ` knee ' , near @xmath1 ev , of the cosmic ray ( cr ) spectrum .
supernova explosions forming collisionless shock waves induce the shocked gas and relativistic particles ( hereafter cosmic rays ) that produce multi - wavelength thermal and nonthermal emission .
diffusive shock acceleration ( dsa ) is the most promising mechanism for converting the kinetic energy of a supernova explosion into energetic particles @xcite and plays an important role in nonthermal emission during the overall process , ( e.g. , @xcite ) . in the framework of dsa , an.
Please generate the next two sentences of the article | individual charged particle experiences many collisions with background electromagnetic waves and gains energy by shock crossing .
this leads to a nonthermal cr spectrum of the power - law form @xmath2 . |
9,229 | Suppose that you have an abstract for a scientific paper: this paper is a review of previous works on the stochastic background of gravitational waves ( sbgws ) which has been discussed in various peer - reviewed journals and international conferences .
the sbgws is analyzed with the aid of the wilkinson microwave anisotropy probe ( wmap ) data .
we emphasize that , in general , in previous works in the literature about the sbgws , old cosmic background explorer ( cobe ) data were used .
after this , we want to face the problem of how the sbgws and f(r ) gravity ( where f(r ) is a function of the ricci scalar r ) can be related , showing , vice versa , that a revealed sbgws could be a powerful probe for a given theory of gravity . in this way
, it will also be shown that the conform treatment of sbgws can be used to parametrize in a natural way f(r ) theories . some interesting examples which have been recently discussed in the literature will be also analysed .
the presence and the potential detection of the sbgws is quite important in the framework of the debate on high - frequency gravitational waves ( hfgws ) too .
recently , the importance of hfgws has been emphasized in some papers in the literature .
associazione scientifica galileo galilei , via pier cironi 16 , i-59100 prato italy and 0574news.it - sezione scientifico - tecnologica , via sante pisani 46 - 59100 prato , italy _ e - mail address : _
pacs numbers : 04.80.nn , 04.30.nk , 04.50.+h keywords : gravitational waves ; extended theories of gravity ; stochastic background ; high - frequency gravitational waves .
And you have already written the first three sentences of the full article: the accelerated expansion of the universe , which is today observed , shows that cosmological dynamic is dominated by the so called dark energy which gives a large negative pressure .
this is the standard picture , in which such new ingredient is considered as a source of the _ right hand side _ of the well known friedman - robertson - walker field equations @xcite .
it should be some form of non - clustered and non - zero vacuum energy which , together with the clustered dark matter , drives the global dynamics ..
Please generate the next two sentences of the article | this is the so called `` concordance model '' ( lambda cold dark matter , @xmath0cdm ) which gives , in agreement with the cosmic microwave background radiation ( cmbr ) , large structure scale ( lss ) and supernovae ia ( sneia ) data , a good framework of the today observed universe , but presents several shortcomings as the well known `` coincidence '' and `` cosmological constant '' problems @xcite .
an alternative approach is changing the _ left hand side _ of the field equations , seeing if observed cosmic dynamics can be achieved extending general relativity @xcite . in this different context , it is not required to find out candidates for dark energy and dark matter , that , till now , have not been found , but only the `` observed '' ingredients , which are curvature and baryon matter , have to be taken into account . |
9,230 | Suppose that you have an abstract for a scientific paper: we present the first high - resolution spectroscopic study on the orphan stream for five stream candidates , observed with the magellan inamori kyocera echelle ( mike ) spectrograph on the magellan clay telescope .
the targets were selected from the low - resolution catalog of @xcite : 3 high - probability members , 1 medium and 1 low - probability stream candidate were observed .
our analysis indicates the low and medium - probability target are metal - rich field stars .
the remaining three high - probability targets range over @xmath01dex in metallicity , and are chemically distinct compared to the other 2 targets and all standard stars : low [ @xmath1/fe ] abundance ratios are observed , and lower limits are ascertained for [ ba / y ] , which sit well above the milky way trend .
these chemical signatures demonstrate that the undiscovered parent system is unequivocally a dwarf spheroidal galaxy , consistent with dynamical constraints inferred from the stream width and arc . as such
, we firmly exclude the proposed association between ngc 2419 and the orphan stream .
a wide range in metallicities adds to the similarities between the orphan stream and segue 1 , although low [ @xmath1/fe ] abundance ratios in the orphan stream are in tension with high [ @xmath1/fe ] values observed in segue 1 .
open questions remain before segue 1 could possibly be claimed as the ` parent ' of the orphan stream .
the parent system could well remain undiscovered in the southern sky . .
And you have already written the first three sentences of the full article: a prolonged , quiescent period followed the creation of the universe . eventually , minuscule dark matter density perturbations initiated the collapse of dark matter , forming gravitational potential wells and giving rise to the condensation of primordial gas clouds ( e.g. , * ? ? ? * ) .
this process furnished the universe with the earliest building blocks , laying the foundation for cosmological structure .
separate building blocks ( i.e. , gas fragments ) underwent independent chemical enrichment before conglomerating to form larger systems ..
Please generate the next two sentences of the article | evidence of this hierarchical formation @xcite remains observable today through the accretion of satellite systems onto the milky way halo .
although the formation history of the galaxy is tangled and chaotic , it serves as an excellent and more importantly , accessible laboratory to investigate the evolution of the universe since the earliest times . |
9,231 | Suppose that you have an abstract for a scientific paper: i review arguments for the existence of a critical point @xmath0 in the qcd phase diagram as a function of temperature @xmath1 and baryon chemical potential @xmath2 .
i describe how heavy ion collision experiments at the sps and rhic can discover the tell - tale signatures of such a critical point , thus mapping this region of the qcd phase diagram .
i contrast the different ways in which the matter produced in a heavy ion collision can be driven out of equilibrium : quenching out of equilibrium ( possible , but not guaranteed , if the transition region is traversed at @xmath3 ) vs. slowing out of equilibrium ( guaranteed for @xmath4 ) vs. bubbling out of equilibrium ( possible , but not guaranteed , for @xmath5 ) .
quenching or bubbling create and amplify distinct , detectable , non - gaussian fluctuations .
in contrast , slowing out of equilibrium reduces the magnitude of the specific , detectable , gaussian fluctuations which signal the presence of the critical point . .
And you have already written the first three sentences of the full article: one goal of relativistic heavy ion collision experiments is to explore and map the qcd phase diagram as a function of temperature and baryon chemical potential .
recent theoretical developments suggest that a key qualitative feature , namely a critical point which in a sense defines the landscape to be mapped , may be within reach of discovery and analysis by the cern sps or by rhic , as data is taken at several different energies @xcite .
the discovery of the critical point would in a stroke transform the map of the qcd phase diagram from one based only on reasonable inference from universality , lattice gauge theory and models into one with a solid experimental basis @xcite . in qcd with two massless quarks ( @xmath6 ; @xmath7 ).
Please generate the next two sentences of the article | the phase transition at which chiral symmetry is restored as @xmath1 is increased with @xmath8 is likely second order and belongs to the universality class of @xmath9 spin models in three dimensions @xcite .
below @xmath10 , chiral symmetry is broken and there are three massless pions . at @xmath11 , there are four massless degrees of freedom : the pions and the sigma . above @xmath11 , the pion and sigma correlation lengths are degenerate and finite . in nature , the light quarks are not massless . because of this explicit chiral symmetry breaking , |
9,232 | Suppose that you have an abstract for a scientific paper: the main result of this paper is to show that if @xmath0 is a normal subgroup of a kleinian group @xmath1 such that @xmath2 contains a coset which is represented by some loxodromic element , then the hausdorff dimension of the transient limit set of @xmath0 coincides with the hausdorff dimension of the limit set of @xmath1 .
this observation extends previous results by fernndez and melin for riemann surfaces . *
ams classification : * 30 f 40 , 37 f 99 , 37 f 30 , 28 a 80 . *
keywords : * kleinian groups ; poincar exponent ; fractal geometry ; dissipative dynamics . .
And you have already written the first three sentences of the full article: in this paper we study fractal geometric aspects of the limit set @xmath3 of a normal subgroup @xmath0 of some given non - elementary kleinian group @xmath1 acting on @xmath4-dimensional hyperbolic space @xmath5 .
we always assume that @xmath2 contains a coset which is represented by some loxodromic isometry @xmath6 .
it is well known that in this situation @xmath3 coincides with the limit set @xmath7 of the larger group @xmath1 ..
Please generate the next two sentences of the article | however , a comparison of finer aspects of these two limit sets usually turns out to be far more involved , as can be seen , for instance , in the work of brooks @xcite and rees @xcite .
+ in this paper we investigate the set @xmath8 of directions at some arbitrary point @xmath9 on the manifold @xmath10 associated with @xmath0 for which the resulting geodesic movement on @xmath10 eventually escapes from every compact region on @xmath10 , but which is nevertheless contained in the @xmath11-neighbourhood of some sequence of closed loops starting and ending at @xmath9 on @xmath10 , for each @xmath12 . |
9,233 | Suppose that you have an abstract for a scientific paper: we analyze the critical behavior of two - dimensional @xmath0-vector spin systems with noncollinear order within the five - loop renormalization - group approximation .
the structure of the rg flow is studied for different @xmath0 leading to the conclusion that the chiral fixed point governing the critical behavior of physical systems with @xmath1 and @xmath2 does not coincide with that given by the @xmath3 expansion .
we show that the stable chiral fixed point for @xmath4 , including @xmath1 and @xmath2 , turns out to be a focus .
we give a complete characterization of the critical behavior controlled by this fixed point , also evaluating the subleading crossover exponents .
the spiral - like approach of the chiral fixed point is argued to give rise to unusual crossover and near - critical regimes that may imitate varying critical exponents seen in numerous physical and computer experiments .
-0.4 in 0.4 in 9.0 in .
And you have already written the first three sentences of the full article: the critical behavior of two - dimensional frustrated spin models with noncollinear or canted order has been the object of intensive theoretical and experimental studies , being of prime interest for those investigating layered magnetic systems with special structures and superconducting josephson - junction arrays in an external magnetic field . in physical magnets , frustration ( leading to noncollinear order ) may arise either because of the special geometry of the lattice or from the competition of different kinds of interactions .
an example of the first kind is the two - dimensional triangular antiferromagnet , whereas for the latter case typical models are the fully frustrated @xmath5 model on a square lattice and models with different nearest - neighbor and next - nearest - neighbor interactions . in these systems
the hamiltonian is minimized by the noncollinear configurations with a 120@xmath6 spin structure . as a consequence , at criticality.
Please generate the next two sentences of the article | , there is a breakdown of o(@xmath0 ) symmetry in the high - temperature phase to o(@xmath7 ) symmetry in the ordered phase .
field - theoretical ( ft ) studies of systems with noncollinear order are based on the o(@xmath0)@xmath8o(@xmath9 ) symmetric landau - ginzburg - wilson ( lgw ) hamiltonian @xcite @xmath10 + { 1\over 4!}u_0 \left ( \sum_a \phi_a^2\right)^2 \right . \left . + { 1\over 4 ! } v_0 \sum_{a , b } \left [ ( \phi_a \cdot \phi_b)^2 - \phi_a^2\phi_b^2\right ] \right\ } , \label{lgwh}\end{aligned}\ ] ] where @xmath11 ( @xmath12 ) are @xmath9 sets of @xmath0-component vectors . |
9,234 | Suppose that you have an abstract for a scientific paper: we determine the relative ages of the open cluster ngc 188 and selected hipparcos field stars by isochrone fitting , and compare them to the age of the thick disk globular cluster 47 tuc .
the best fit age for ngc 188 was determined to be 6.5 @xmath01.0 gyr .
the solar metallicity hipparcos field stars yielded a slightly older thin disk age , 7.5 @xmath00.7 gyr .
two slightly metal - poor ( @xmath1$}}= -0.22 $ ] ) field stars whose kinematic and orbital parameters indicate that they are members of the thin disk were found to have an age of @xmath2 gyr .
the age for 47 tuc was determined to be 12.5 @xmath01.5 gyr .
all errors are internal errors due to the uncertainty in the values of metallicity and reddening .
thus , the oldest stars dated in the thin disk are found to be @xmath3 gyr younger than 47 tuc .
furthermore , as discussed by @xcite 47 tuc has a similar age to three globular clusters located in the inner part of the galactic halo , implying that star formation in the thin disk started within @xmath3 gyr of star formation in the halo . .
And you have already written the first three sentences of the full article: the dating of the oldest stars in the milky way allows us to infer the early history of star formation in our galaxy , and hence , provides us with important information regarding the formation of the milky way .
a great deal of attention has been paid to the ages of globular clusters ( see for example the reviews by @xcite ) in the halo and there have been a number of studies which determine the ages of the oldest open clusters in the thin disk ( e.g. @xcite ; ( * ? ? ?
* hereafter cgl ) ) . typically , there appears to be a gap of several gyr between the ages of the globular clusters and the ages determined for the oldest stars in the thin disk ..
Please generate the next two sentences of the article | we have elected to investigate this further , in order to quantify the age difference ( if any ) between the thin disk , the thick disk and the halo of the milky way . in recent years , numerous techniques have been employed to determine the ages of the oldest stars in the galactic ( thin ) disk .
@xcite examined the color magnitude diagram ( cmd ) of hipparcos field stars and arrived at a minimum disk age of 8 gyr ; @xcite used isochrone fits to determine the ages of several old open clusters . @xcite and @xcite used observations of local white dwarfs and theoretical white dwarf cooling curves to determine a local disk age of @xmath4 gyr and @xmath5 gyr respectively . |
9,235 | Suppose that you have an abstract for a scientific paper: we present the design of the simulation package pluto , aimed at the study of hadronic interactions at sis and fair energies .
its main mission is to offer a modular framework with an object - oriented structure , thereby making additions such as new particles , decays of resonances , new models up to modules for entire changes easily applicable .
overall consistency is ensured by a plugin- and distribution manager .
particular features are the support of a modular structure for physics process descriptions , and the possibility to access the particle stream for on - line modifications .
additional configuration and self - made classes can be attached by the user without re - compiling the package , which makes pluto extremely configurable .
@xmath0 institut fr kernphysik , goethe - universitt , 60438 frankfurt , germany + @xmath1 gsi helmholtzzentrum fr schwerionenforschung gmbh , 64291 darmstadt , germany + @xmath2 institut de physique nuclaire dorsay , cnrs / in2p3 , 91406 orsay cedex , france + @xmath3 smoluchowski institute of physics , jagiellonian university of cracow , 30 - 059 krakw , poland .
And you have already written the first three sentences of the full article: due to the fact , that experimental setups are usually not suited to cover the complete complete phase space , event generators are very important tools for experiments .
practically , the experimental physicist needs a tool in hand which allows to control almost all kinematic variables with a manageable user interface and to exchange the physics models which have to be compared to measured data . in our contribution
, we present the software structure of the pluto event generator @xcite originally developed for the hades experiment @xcite but successfully used by other collaborations in the hadronic physics field as well ..
Please generate the next two sentences of the article | its recent redesign partly discussed in this contribution enhanced its flexibility and provide new features which allow to meet new challenges coming with the detector studies for the new fair experiments panda @xcite and cbm @xcite .
pluto is a collection of c++ classes , adding up to the framework of a simulation package for hadronic physics interactions in the energy regime up to a few gev . |
9,236 | Suppose that you have an abstract for a scientific paper: we make a case for the existence for ultra - massive black holes ( umbhs ) in the universe , but argue that there exists a likely upper limit to black hole masses of the order of @xmath0 .
we show that there are three strong lines of argument that predicate the existence of umbhs : ( i ) expected as a natural extension of the observed black hole mass bulge luminosity relation , when extrapolated to the bulge luminosities of bright central galaxies in clusters ; ( ii ) new predictions for the mass function of seed black holes at high redshifts predict that growth via accretion or merger - induced accretion inevitably leads to the existence of rare umbhs at late times ; ( iii ) the local mass function of black holes computed from the observed x - ray luminosity functions of active galactic nuclei predict the existence of a high mass tail in the black hole mass function at @xmath1 .
consistency between the optical and x - ray census of the local black hole mass function requires an upper limit to black hole masses .
this consistent picture also predicts that the slope of the @xmath2-@xmath3 relation will evolve with redshift at the high mass end .
models of self - regulation that explain the co - evolution of the stellar component and nuclear black holes naturally provide such an upper limit .
the combination of multi - wavelength constraints predicts the existence of umbhs and simultaneously provides an upper limit to their masses .
the typical hosts for these local umbhs are likely the bright , central cluster galaxies in the nearby universe .
galaxies : evolution , active , nuclei .
x - rays : galaxies . .
And you have already written the first three sentences of the full article: observations of black hole demographics locally is increasingly providing a strong constraint on models that explain the assembly and growth of black holes in the universe .
the existence of a tight relation between the velocity dispersion of bulges and the mass of the central black hole has been reported by several authors ( merritt & ferrarese 2001 ; tremaine et al .
2002 ; gebhardt et al ..
Please generate the next two sentences of the article | this correlation is tighter than that between the luminosity of the bulge and the mass of the central black hole ( magorrian et al .
1998 ) . the physical processes that set up this correlation |
9,237 | Suppose that you have an abstract for a scientific paper: nondominated sorting is a combinatorial algorithm that sorts points in euclidean space into layers according to a partial order .
it was recently shown that nondominated sorting of random points has a hamilton - jacobi equation continuum limit .
the original proof , given in @xcite , relies on a continuum variational problem . in this paper
, we give a new proof using a direct verification argument that completely avoids the variational interpretation .
we believe this proof is new in the homogenization literature , and may be generalized to apply to other stochastic homogenization problems for which there is no obvious underlying variational principle . .
And you have already written the first three sentences of the full article: many problems in science and engineering require the sorting , or ordering , of large amounts of multivariate data . since there is no canonical linear criterion for sorting data in dimensions greater than one , many different methods for sorting
have been proposed to address various problems ( see , e.g. , @xcite ) .
many of these algorithms abandon the idea of a linear ordering , and instead sort the data into layers according to some set of criteria ..
Please generate the next two sentences of the article | we consider here _ nondominated sorting _ , which arranges a set of points in euclidean space into layers by repeatedly removing the set of minimal elements .
let @xmath0 denote the coordinatewise partial order on @xmath1 defined by @xmath2 the _ first nondominated layer _ , also called the _ first pareto front _ and denoted @xmath3 , is exactly the set of minimal elements of @xmath4 with respect to @xmath0 , and the deeper fronts are defined recursively as follows : @xmath5 this peeling process eventually exhausts the entire set @xmath4 , and the result is a partition of @xmath4 based on pareto front index , which is often called _ pareto depth _ or _ rank_. figure [ fig : demo ] gives an illustration of nondominated sorting of a random set @xmath4 . |
9,238 | Suppose that you have an abstract for a scientific paper: teleparallel theories of gravity have a long history .
they include a special case referred to as the _ teleparallel equivalent of general relativity _
( tegr , aka gr@xmath0 ) .
recently this theory has been generalized to @xmath1 gravity .
tight constraints from observations suggest that @xmath1 gravity is not as robust as initially hoped .
this might hint at hitherto undiscovered problems at the theoretical level . in this work ,
we point out that a generic @xmath1 theory can be expected to have certain problems including superluminal propagating modes , the presence of which can be revealed by using the characteristic equations that govern the dynamics in @xmath1 gravity and/or the hamiltonian structure of the theory via dirac constraint analysis .
we use several examples from simpler gauge field theories to explain how such superluminal modes could arise .
we also point out problems with the cauchy development of a constant time hypersurface in flrw spacetime in @xmath1 gravity . the time evolution from a flrw ( and as a special case , minkowski spacetime ) initial condition is not unique . .
And you have already written the first three sentences of the full article: einstein proposed the idea of teleparallelism , or _ fernparallelismus _ ( aka _ absolute parallelism _ , _ distant parallelism _ ) , in order to unify gravity and electromagnetism @xcite .
unlike general relativity , spacetime in teleparallelism is equipped with a connection with zero curvature , but non - vanishing torsion . since the spacetime is _ flat
_ , the parallel transport of a vector is independent of path , and hence the name _ _.
Please generate the next two sentences of the article | tele__parallel , meaning `` parallel at a distance '' .
einstein s quest for unification via teleparallel theory can be found in the interesting account of @xcite . despite einstein s failure to formulate a unified theory , |
9,239 | Suppose that you have an abstract for a scientific paper: we present an automatic , fast , accurate and robust method of classifying astronomical objects .
the self organizing map ( som ) as an unsupervised artificial neural network ( ann ) algorithm is used for classification of stellar spectra of stars .
the som is used to make clusters of different spectral classes of jacoby , hunter and christian ( jhc ) library .
this ann technique needs no training examples and the stellar spectral data sets are directly fed to the network for the classification .
the jhc library contains 161 spectra out of which , 158 spectra are selected for the classification .
these 158 spectra are input vectors to the network and mapped into a two dimensional output grid .
the input vectors close to each other are mapped into the same or neighboring neurons in the output space .
so , the similar objects are making clusters in the output map and making it easy to analyze high dimensional data . after running the som algorithm on 158 stellar spectra , with 2799 data points each ,
the output map is analyzed and found that , there are 7 clusters in the output map corresponding to o to m stellar type .
but , there are 12 misclassifications out of 158 and all of them are misclassified into the neighborhood of correct clusters which gives a success rate of about 92.4% . .
And you have already written the first three sentences of the full article: artificial neural networks are now becoming a more popular tools for handling astronomical data .
it is very important to have some automatic means of analyzing large databases like the surveys and upcoming space missions which would release terabytes of data to the community .
that is why , anns are widely used as an automatic tools for analyzing astronomical data ..
Please generate the next two sentences of the article | some of the previous attempts on anns in astronomy are : @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite .
artificial neural network techniques used in the field of astronomy have been mostly supervised algorithms . here |
9,240 | Suppose that you have an abstract for a scientific paper: we introduce a monogamy inequality for quantum correlations , which implies that the sum of pairwise quantum correlations is upper limited by the amount of multipartite quantum correlations as measured by the global quantum discord .
this monogamy bound holds either for pure or mixed quantum states provided that bipartite quantum discord does not increase under discard of subsystems .
we illustrate the monogamy behavior for multipartite pure states with schmidt decomposition as well as for w - ghz mixed states . as a by - product
, we apply the monogamy bound to investigate residual multipartite correlations . .
And you have already written the first three sentences of the full article: quantum discord ( qd ) @xcite has recently been identified as a general resource in quantum information protocols ( see , e.g. , refs .
@xcite ) . in quantum computation
, it has been conjectured as the origin of speed up in the deterministic quantum computation with one qubit ( dqc1 ) mixed - state model @xcite ..
Please generate the next two sentences of the article | moreover , a fundamental role has been attributed to qd in tasks such as quantum locking @xcite and quantum state discrimination @xcite . besides quantum protocols , remarkable applications of qd have also been found in the characterization of quantum phase transitions @xcite and in the description of quantum dynamics under decoherence @xcite . in order to use quantum correlations ( as provided by qd ) as a resource , we are faced with the problem of their distribution throughout a multipartite state . in this context , a monogamous behavior may reveal important information about the structure of quantum correlations . for instance , monogamy has been found to be the essential feature allowing for security in quantum key distribution @xcite . in general grounds
, it has been investigated whether any given measure @xmath0 of bipartite quantum correlation can obey a monogamy bound in an arbitrary tripartite quantum system @xmath1 . |
9,241 | Suppose that you have an abstract for a scientific paper: the linear response description for impurity diffusion in a granular fluid undergoing homogeneous cooling is developed in the preceeding paper .
the formally exact einstein and green - kubo expressions for the self - diffusion coefficient are evaluated there from an approximation to the velocity autocorrelation function .
these results are compared here to those from molecular dynamics simulations over a wide range of density and inelasticity , for the particular case of self - diffusion .
it is found that the approximate theory is in good agreement with simulation data up to moderate densities and degrees of inelasticity . at higher density ,
the effects of inelasticity are stronger , leading to a significant enhancement of the diffusion coefficient over its value for elastic collisions .
possible explanations associated with an unstable long wavelength shear mode are explored , including the effects of strong fluctuations and mode coupling . .
And you have already written the first three sentences of the full article: attempts to describe granular media in terms of a more fundamental underlying statistical mechanics have met with considerable success . as a prototype for this approach , in the preceding paper @xcite standard linear response methods from normal fluids have been applied , _ mutatis mutandis _
, to the case of an impurity particle diffusing in an isolated one component fluid of smooth inelastic hard spheres ( @xmath0 ) or disks ( @xmath1 ) of diameter @xmath2 .
the collisions are characterized by a coefficient of normal restitution @xmath3 . the isolated system ( or with periodic boundary conditions ) , is not in the typical gibbs state as for elastic collisions , but rather in a time dependent homogeneous cooling state ( hcs ) ..
Please generate the next two sentences of the article | it has been shown in @xcite , and will be elaborated further here , that this time dependent hcs can be exactly transformed to a stationary state description . in the present work ,
this stationary state description is evaluated by molecular dynamics ( md ) simulation to measure the mean square displacement of the impurity , its velocity autocorrelation function , and the resulting diffusion coefficient defined in terms of a formal einstein or green - kubo relation , respectively . for practical purposes , |
9,242 | Suppose that you have an abstract for a scientific paper: we analyse the thermodynamic properties of a generalised dicke model , i.e.a collection of three - level systems interacting with two bosonic modes .
we show that at finite temperatures the system undergoes first - order phase transitions only , which is in contrast to the zero - temperature case where a second - order phase transition exist as well .
we discuss the free energy and prominent expectation values .
the limit of vanishing temperature is discussed as well . .
And you have already written the first three sentences of the full article: the dicke superradiance model @xcite as a test - bed for mean - field like phase transitions @xcite has received renewed attention recently , in particular due to its successful implementation in cold - atom experiments @xcite and optical setups of cavities and lasers @xcite .
much progress has been made towards a realistic description of non - equilibrium and dissipation @xcite , multi - mode effects @xcite , the interplay of the superradiant phase transitions and bose
einstein condensation @xcite , spin glasses @xcite , the analysis of interactions @xcite , inhomogeneous couplings @xcite , finite size effects @xcite , or the adiabatic limit @xcite.
Please generate the next two sentences of the article | . further extensions of the model have appeared allowing for driving @xcite , the creation of goldstone modes @xcite , feedback control @xcite , or the transfer to other platforms such as solid - state systems @xcite . in its simplest version ,
the dicke model hosts a mean - field type ground state phase transition ( ` quantum bifurcation ' ) at zero temperature @xcite between a field - free ( normal ) phase with unpolarised atoms , and a superradiant phase with macroscopic occupation of the field mode and polarisation of the atoms . above a critical coupling strength , the superradiant phase also persists at finite temperatures below a critical temperature which defines the corresponding thermal second order phase transition @xcite . |
9,243 | Suppose that you have an abstract for a scientific paper: in this paper , we present a geometric variational algorithm for optimizing the gaits of kinematic locomoting systems .
the dynamics of this algorithm are analogous to the physics of a soap bubble , with the system s lie bracket supplying an `` inflation pressure '' that is balanced by a `` surface tension '' term derived from a riemannian metric on the system s shape space .
we demonstrate this optimizer on a variety of system geometries ( including purcell s swimmer ) and for optimization criteria that include maximizing displacement and efficiency of motion for both translation and turning motions . .
And you have already written the first three sentences of the full article: gait optimization algorithms for locomoting systems must contend with a number of nonlinear effects , including : shape - dependent system dynamics ( and thus a control structure that depends on the state of the controller and not just the plant ) ; and history - dependent input - output mappings ( e.g. if one part of the gait rotates the system , future translational sections will propel the system in a new direction ) .
the geometric mechanics community has long recognized that lie brackets of the system dynamics can be used to provide an understanding of these nonlinearities , and thereby to identify shape oscillations that produce useful net displacements through the world @xcite . for kinematic locomoting systems with two shape variables ( a class which includes a number of informative systems in viscous , granular , inertial , and fluid environments @xcite )
, the lie bracket can be visualized as a set of `` height functions '' over the shape space , whose topographies identify good placements for gait trajectories . for example , gaits that move a system forward encircle positive peaks ( or negative valleys ) in the @xmath0 component of the lie bracket , whereas gaits that turn the system with minimal translation enclose sign - definite regions in the @xmath1 component and balanced positive and negative regions in the @xmath0 and @xmath2 components ..
Please generate the next two sentences of the article | an enduring goal @xcite of this community has been to go beyond simply identifying the direction in which small shape oscillations will propel the system , and to use the lie bracket principle to identify optimal gaits that generate the most displacement , either per gait cycle or per energy expended . for example , a gait that completely encircles a sign - definite region of a height function ( by tracing out its zero - contour ) would maximize displacement in the corresponding direction ; similarly , a contraction of the zero contour that balances the enclosed area against the perimeter length ( effort ) required to capture it would maximize the efficiency with which this displacement is achieved @xcite . a key obstacle to reaching this goal was the noncommutativity in the equations of motion for most interesting locomoting systems .
because translations and rotations do not commute with each other , summing up lie brackets over a finite region provides only an approximation of the displacement induced by a gait , and the error in this approximation increases with the amplitude of the oscillation . |
9,244 | Suppose that you have an abstract for a scientific paper: for the anisotropic @xmath0$]-theory with we calculate the imaginary parts of the renormalization - group functions in the form of a series expansion in @xmath1 , around the isotropic case .
dimensional regularization is used to evaluate the fluctuation determinants for the isotropic instanton near the space dimension @xmath2 .
the vertex functions in the presence of instantons are renormalized with the help of a nonperturbative procedure introduced for the simple @xmath3-theory by mckane et al . .
And you have already written the first three sentences of the full article: more than twenty years ago , brezin , le guillou and zinn - justin ( bgz ) studied the phase transition of a cubic anisotropic system by means of renormalization group equations @xcite . within a @xmath4-expansion
, they found that to lowest nontrivial order in @xmath5 , the only stable fixed point for @xmath6 is the @xmath7-symmetric one , where @xmath8 is the number of field components appearing in the cubic anisotropic model .
they interpreted this as an indication that the anisotropy is irrelevant as long as @xmath8 is smaller than four . for @xmath9 , the isotropic fixed point destabilized and the trajectories crossed over to the cubic fixed point ..
Please generate the next two sentences of the article | recently , our knowledge of perturbation coefficients of the renormalization group functions of the anisotropic system was extended up to the five - loop level by kleinert and schulte - frohlinde @xcite .
since the perturbation expansions are badly divergent , they do not directly yield improved estimates for the crossover value @xmath10 where the isotropic fixed point destabilizes in favor of the cubic one . |
9,245 | Suppose that you have an abstract for a scientific paper: the hadroproduction of lepton pairs with mass @xmath0 and finite transverse momentum @xmath1 is described in perturbative qcd by the same partonic subprocesses as prompt photon production .
we demonstrate that , like prompt photon production , lepton pair production is dominated by quark - gluon scattering in the region @xmath2 .
this feature leads to sensitivity to the gluon density in kinematical regimes accessible in collider and fixed target experiments , and it provides a new independent method for constraining the gluon density .
anl - hep - cp-00 - 002 + desy
00 - 006 .
And you have already written the first three sentences of the full article: the production of lepton pairs in hadron collisions @xmath3 proceeds through an intermediate virtual photon via @xmath4 , and the subsequent leptonic decay of the virtual photon .
traditionally , interest in this drell - yan process has concentrated on lepton pairs with large mass @xmath0 which justifies the application of perturbative qcd and allows for the extraction of the antiquark density in hadrons @xcite .
prompt photon production @xmath5 can be calculated in perturbative qcd if the transverse momentum @xmath1 of the photon is sufficiently large . because the quark - gluon compton subprocess is dominant , @xmath6 , this reaction provides essential information on the gluon density in the proton at large @xmath7 @xcite ..
Please generate the next two sentences of the article | unfortunately , the analysis suffers from fragmentation , isolation , and intrinsic transverse momentum uncertainties .
alternatively , the gluon density can be constrained from the production of jets with large transverse momentum at hadron colliders @xcite , but the information from different experiments and colliders is ambiguous . in this paper |
9,246 | Suppose that you have an abstract for a scientific paper: using the stellar photometry catalogue based on the latest data release ( dr4 ) of the sloan digital sky survey ( sdss ) , a study of the galactic structure using star counts is carried out for selected areas of the sky .
the sample areas are selected along a circle at a galactic latitude of + 60@xmath0 , and 10 strips of high galactic latitude along different longitudes .
direct statistics of the data show that the surface densities of @xmath1 from @xmath2 to @xmath3 are systematically higher than those of @xmath1 from @xmath4 to @xmath2 , defining a region of overdensity ( in the direction of virgo ) and another one of underdensity ( in the direction of ursa major ) with respect to an axisymmetric model .
it is shown by comparing the results from star counts in the @xmath5 colour that the density deviations are due to an asymmetry of the stellar density in the halo .
theoretical models for the surface density profile are built and star counts are performed using a triaxial halo of which the parameters are constrained by observational data .
two possible reasons for the asymmetric structure are discussed .
[ firstpage ] stars : statistics the galaxy : structure , fundamental parameters , halo .
And you have already written the first three sentences of the full article: it has been one of the central goals of human knowledge to understand the position of the earth in the universe .
a lot of effort has been spent to derive the structure and the history of formation and evolution of our galaxy . doing
this is a particularly difficult task , simply because there is no good viewpoint , as opposed to the case for external galaxies whose structures can be observed directly ..
Please generate the next two sentences of the article | the structure , formation and evolution of the galaxy are very important issues in contemporary astrophysics ; they are closely related to stellar quantities such as distance , age , metallicity , and kinematics of the individual stars , among others .
these properties can be obtained for large stellar samples using straightforward photometric and spectroscopic observations . in the present era , before the full exploitation of the planned huge spectral surveys of galactic stellar objects ( e.g. gaia , segue , 6df , lamost ) is possible , using star counts based on all - sky photometric surveys is a direct and one of the few accessible methods for the study of the structure of the galaxy . probing the galaxy using star counts has a history of about 200 years ( reid 1993 ) , with the modern epoch marked by the classic work of bahcall & soneira ( 1980 ) , based on several observations ( seares et al . |
9,247 | Suppose that you have an abstract for a scientific paper: we have generated new , self - consistent spectral and atmosphere models for the effective temperature range 600 k to 1300 k thought to encompass the known t dwarfs .
for the first time , theoretical models are compared with a _ family _ of measured t dwarf spectra at wavelengths shortward of @xmath01.0 micron . by defining spectral indices and standard colors in the optical and very near - infrared
, we explore the theoretical systematics with , gravity , and metallicity .
we conclude that the short - wavelength range is rich in diagnostics that complement those in the near - infrared now used for spectral subtyping .
we also conclude that the wings of the na d and k i ( 7700 ) resonance lines and aggressive rainout of heavy metals ( with the resulting enhancement of the sodium and potassium abundances at altitude ) are required to fit the new data shortward of 1.0 .
furthermore , we find that the water bands weaken with increasing gravity , that modest decreases in metallicity enhance the effect in the optical of the sodium and potassium lines , and that at low , in a reversal of the normal pattern , optical spectra become bluer with further decreases in .
moreover , we conclude that t dwarf subtype is not a function of alone , but that it is a non - trivial function of gravity and metallicity as well . as do marley et al .
( 2001 ) , we see evidence in early t dwarf atmospheres of a residual effect of clouds . with cloudless models , we obtain spectral fits to the two late t
dwarfs with known parallaxes , but a residual effect of clouds on the emergent spectra of even late t dwarfs can not yet be discounted
. however , our focus is not on detailed fits to individual objects , but on the interpretation of the overall spectral and color trends of the entire class of t dwarfs , as seen at shorter wavelengths . .
And you have already written the first three sentences of the full article: the discovery of gliese 229b ushered in a new chapter in stellar astronomy by penetrating unambiguously below the main sequence edge ( nakajima et al . 1995 ; oppenheimer et al .
1995 ) . in gliese 229b ,
absorption in the far infrared due to collision - induced absorption ( cia ) by h@xmath1 and the lack of absorption in the near infrared at the classic steam opacity windows together result in a redistribution of gliese 229b s emergent flux from the mid- and far - ir to the @xmath2 ( @xmath01.05 ) , @xmath3 ( @xmath01.25 ) , @xmath4 ( @xmath01.6 ) , and @xmath5 ( @xmath02.2 ) bands in the near - infrared ..
Please generate the next two sentences of the article | these band fluxes exceed the corresponding black body values for a given by as much as two to three orders of magnitude . given the importance of the near - infrared bands , it is only natural that they be used to help establish the associated new spectral types ( burgasser et al .
2001a ; geballe et al . |
9,248 | Suppose that you have an abstract for a scientific paper: in this paper , a hub refers to a non - terminal vertex of degree at least three .
we study the minimum number of hubs needed in a network to guarantee certain flow demand constraints imposed between multiple pairs of sources and sinks .
we prove that under the constraints , regardless of the size or the topology of the network , such minimum number is always upper bounded and we derive tight upper bounds for some special parameters . in particular , for two pairs of sources and sinks , we present a novel path - searching algorithm ,
the analysis of which is instrumental for the derivations of the tight upper bounds . .
And you have already written the first three sentences of the full article: consider a network @xmath0 , where @xmath1 denotes the set of vertices in @xmath2 , and @xmath3 denotes the set of edges in @xmath2 .
a vertex in @xmath2 is said to be a _ source _ if it is only incident with outgoing edges , and a _ sink _ if it is only incident with incoming edges .
often , a source or sink is referred to as a _ terminal _ vertex ..
Please generate the next two sentences of the article | a non - terminal vertex is said to be a _ hub _ if its degree is greater than or equal to @xmath4 . in this paper , we are primarily concerned with the minimum number of hubs needed when certain constraints on the flow demand between multiple pairs of sources and sinks are imposed .
the flow demand constraints considered in this paper will be in terms of the vertex - cuts between pairs of sources and sinks . |
9,249 | Suppose that you have an abstract for a scientific paper: pion virtual compton scattering ( vcs ) via the reaction @xmath0 was observed in the fermilab e781 selex experiment .
selex used a @xmath1 @xmath2 beam incident on target atomic electrons , detecting the incident @xmath2 and the final state @xmath2 , electron and @xmath3 .
theoretical predictions based on chiral perturbation theory are incorporated into a monte carlo simulation of the experiment and are compared to the data .
the number of reconstructed events ( 9 ) and their distribution with respect to the kinematic variables ( for the kinematic region studied ) are in reasonable accord with the predictions .
the corresponding @xmath2 vcs experimental cross section is @xmath4 , in agreement with the theoretical expectation @xmath5 . .
And you have already written the first three sentences of the full article: the electric @xmath6 and magnetic @xmath7 pion polarizabilities characterize the pion s deformation in an electromagnetic field , as occurs during @xmath8 compton scattering .
they depend on the rigidity of the pion s internal structure as a composite particle , and are therefore important dynamical quantities to test the validity of theoretical models . based on qcd chiral dynamics , the chiral perturbation theory effective lagrangian
, using data from radiative pion beta decay , predicts the pion electric and magnetic polarizabilities.
Please generate the next two sentences of the article | @xmath9 = -@xmath10 = 2.7 @xmath11 0.4 , expressed in units of @xmath12 @xcite .
other theoretical predictions are also available @xcite . |
9,250 | Suppose that you have an abstract for a scientific paper: the goal for future neutrino facilities is the determination of the u(e3 ) mixing and cp violation in neutrino oscillations .
this will require precision experiments with a very intense neutrino source and energy control . with this objective in mind ,
the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the sps of cern has been proposed .
we discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector .
we conclude that the sps upgrade to 1000 gev is crucial to reach a better sensitivity to cp violation iff it is accompanied by a longer baseline .
we compare the physics potential for two different configurations : i ) @xmath0 and @xmath1 ( maximum achievable at present sps ) to frejus ; ii ) @xmath1 and @xmath2 ( maximum achievable at upgraded sps ) to canfranc .
the main conclusion is that , whereas the gain in the determination of u(e3 ) is rather modest , setup ii provides much better sensitivity to cp violation . .
And you have already written the first three sentences of the full article: a number of experimental facilities to significantly improve on present sensitivity to the connecting mixing @xmath3 in neutrino oscillations and have access to the cp - violating phase @xmath4 have been discussed in the literature : neutrino factories ( neutrino beams from boosted - muon decays ) , superbeams ( very intense conventional neutrino beams ) , improved reactor experiments and more recently @xmath5-beams @xcite .
the original standard scenario for beta beams with lower @xmath6 and short baseline @xmath7 km from cern to frejus with @xmath8 and @xmath9 ions has seen a variant by using an electron capture facility for monochromatic neutrino beams @xcite .
new proposals also include the high @xmath10 value @xmath11 and @xmath12 isotopes in a @xmath13 facility @xcite . in this paper.
Please generate the next two sentences of the article | we discuss the physics reach that a high energy facility for ec beams may provide with the expected sps upgrade at cern .
such study has been made for the standard beta beam facility @xcite . in section 2 |
9,251 | Suppose that you have an abstract for a scientific paper: i review what we currently do and do not know about the masses of disk galaxies and their dark matter halos .
the prognosis for disks is good : the asymptotic rotation velocity provides a good indicator of total disk mass .
the prognosis for halos is bad : cuspy halos provide a poor description of the data , and the total mass of individual dark matter halos remains ill - constrained . .
And you have already written the first three sentences of the full article: the great regularity of the tully - fisher relation @xcite has long been thought to originate from a strong mass - velocity relation and a near constancy of mass - to - light ratio .
the latter requires a fair but not unreasonable amount of regularity in stellar populations .
put simply , ... when it comes to pepper grinders '' ( van den bosch 2001 , private communication ) . ].
Please generate the next two sentences of the article | @xmath0 there have long been indications ( sancisi 1995 , private communication ) that this simple scaling may fail at low luminosities .
this has become more clear as data have improved @xcite,@xcite . |
9,252 | Suppose that you have an abstract for a scientific paper: we study the properties of wave functions and the wave - packet dynamics in quasiperiodic tight - binding models in one , two , and three dimensions .
the atoms in the one - dimensional quasiperiodic chains are coupled by weak and strong bonds aligned according to the fibonacci sequence .
the associated @xmath0-dimensional quasiperiodic tilings are constructed from the direct product of @xmath0 such chains , which yields either the hypercubic tiling or the labyrinth tiling .
this approach allows us to consider rather large systems numerically .
we show that the wave functions of the system are multifractal and that their properties can be related to the structure of the system in the regime of strong quasiperiodic modulation by a renormalization group ( rg ) approach .
we also study the dynamics of wave packets to get information about the electronic transport properties .
in particular , we investigate the scaling behaviour of the return probability of the wave packet with time . applying again the rg approach
we show that in the regime of strong quasiperiodic modulation the return probability is governed by the underlying quasiperiodic structure .
further , we also discuss lower bounds for the scaling exponent of the width of the wave packet and propose a modified lower bound for the absolute continuous regime . .
And you have already written the first three sentences of the full article: in the 1970s works by penrose and ammann showed that the euclidean space can be filled gapless and non - overlapping by two or more tiles which are arranged in a nonperiodic way according to matching rules @xcite .
these quasiperiodic tilings showed a hierarchical structure and long - range oriental order .
the study of such tilings was strongly intensified after the discovery of quasicrystals by shechtman et al . in 1982.
Please generate the next two sentences of the article | these materials are characterized by a perfect long range order without having a three - dimensional translational periodicity .
the former is manifested by the occurrence of sharp spots in the diffraction pattern and the latter in the occurrence of rotational symmetries forbidden for conventional crystals @xcite . |
9,253 | Suppose that you have an abstract for a scientific paper: new high statistics belle data on the @xmath0 reaction cross section measured in the range of pion - pair invariant masses @xmath1 between 0.8 gev and 1.5 gev are analyzed to clarify the current situation around the @xmath2 , @xmath3 , and @xmath4 resonances in @xmath5 collisions .
the present analysis shows that the direct coupling constants of the @xmath2 and @xmath3 resonances to @xmath5 are small , and the @xmath6 and @xmath7 decays are four - quark transitions caused by the @xmath8 and @xmath9 loop mechanisms , respectively .
the chiral shielding of the @xmath2 resonance takes place in the reactions @xmath10 as well as in @xmath11 scattering .
some results of a simultaneous description of the @xmath0 and @xmath12 belle data are also presented . in particular , the following tentative estimate of the @xmath13 decay width is obtained : @xmath14 kev . .
And you have already written the first three sentences of the full article: recently , the belle collaboration performed precise measurements of the @xmath0 reaction cross section for pion - pair invariant masses @xmath1 ranging from 0.8 to 1.5 gev @xcite . owing to the huge statistics and good energy resolution ,
a clear signal from the @xmath3 resonance was first discovered with the belle detector .
evidences for the @xmath3 production in @xmath5 collisions obtained in a series of previous measurements @xcite were essentially less conclusive ..
Please generate the next two sentences of the article | the @xmath3 signal observed in the belle experiment turned out to be rather small .
this feature is in good qualitative agreement with the prediction of the four - quark model @xcite . |
9,254 | Suppose that you have an abstract for a scientific paper: we study the hadronic production of four - quark states with double heavy quarks and double light antiquarks at lhc .
the production mechanism is that a color anti - triplet diquark cluster consisting of double heavy quarks is formed first from the produced double heavy quark - antiquark pairs via @xmath0 fusion hard process , followed by the fragmentation of the diquark cluster into a four - quark ( tetraquark ) state .
predictions for the production cross sections and their differential distributions are presented .
our results show that it is quite promising to discover these tetraquark states in lhc experiments both for large number events and for their unique signatures in detectors .
keyword : tetraquark , diquark , heavy quark , fragmentation , production .
And you have already written the first three sentences of the full article: lhc experiments provide the unique opportunity to explore some exotic states of heavy quarks . among them , particularly interesting states are those four - quark states consisting of double heavy quarks and double light antiquarks ( or their charge conjugator ) .
the existence of such states can be inferred from the heavy quark symmetry .
the double heavy quarks in the color anti - triplet state may form a diquark cluster by the attractive strong interactions . in the heavy quark limit ,.
Please generate the next two sentences of the article | the double heavy quarks move slowly in a small relative velocity @xmath1 in the rest frame within a smaller distance ( @xmath2 ) , comparing to the size of light degree of freedom ( @xmath3 ) .
thus in the tetraquark states the double heavy quarks form a color anti - triplet diquark cluster . |
9,255 | Suppose that you have an abstract for a scientific paper: service - oriented wireless sensor network(wsn ) has been recently proposed as an architecture to rapidly develop applications in wsns . in wsns
, a query task may require a set of services and may be carried out repetitively with a given frequency during its lifetime .
a service composition solution shall be provided for each execution of such a persistent query task . due to the energy saving strategy
, some sensors may be scheduled to be in sleep mode periodically .
thus , a service composition solution may not always be valid during the lifetime of a persistent query .
when a query task needs to be conducted over a new service composition solution , a routing update procedure is involved which consumes energy . in this paper , we study service composition design which minimizes the number of service composition solutions during the lifetime of a persistent query .
we also aim to minimize the total service composition cost when the minimum number of required service composition solutions is derived . a greedy algorithm and a dynamic programming algorithm are proposed to complete these two objectives respectively .
the optimality of both algorithms provides the service composition solutions for a persistent query with minimum energy consumption .
* keywords : * service composition , wireless sensor network , routing , query . .
And you have already written the first three sentences of the full article: service - oriented architecture in wsns@xcite makes it possible to rapidly develop new applications . in a service - oriented wsn
, a typical application requires several different services , e.g. , data aggregation , data processing , decoding , which are provided by service providers that are also sensors .
the task of service composition is to assign each required service to an appropriate service provider according to certain criteria ..
Please generate the next two sentences of the article | service composition with various performance metrics @xcite , e.g. , load balance , end - to - end delay and resource , have been well studied .
service composition in wsns has also recently been studied in @xcite . |
9,256 | Suppose that you have an abstract for a scientific paper: structure and superfluid response of nanoscale size 4 clusters enclosed in spherical cavities are studied by computer simulations .
the curved surface causes the formation of well - defined concentric shells , thus imparting to the system a very different structure from that of free standing clusters . on a strongly attractive substrate ,
superfluidity is only observed at low density , in the single layer coating the inner surface of the cavity .
if the substrate is very weak ( e.g. , li ) , on the other hand , a superfluid two - shell structure can form , whose physical properties interpolate between two and three dimensions .
it is shown how experimental signatures of this physical behavior can be detected through measurements of the momentum distribution . .
And you have already written the first three sentences of the full article: clusters of 4 comprising several tens of atoms ( i.e. , of characteristic size of a few nm ) are perhaps the simplest quantum few - body system ; their investigation , both theoretical and experimental , has been pursued for a few decades now .
early theoretical studies yielded considerable information on their structure,@xcite bose condensation,@xcite excitations@xcite and their predicted superfluid behavior@xcite at temperatures of the order of 1 k. + probing experimentally their physical properties is obviously a difficult proposition , as pristine 4 clusters are very weakly bound , easily fragmented , e.g. , on impact with a scatterer .
thus , although some experiments were carried out , in which low energy 4 atoms were scattered off 4 clusters,@xcite most of what is now known about their physics , chiefly their superfluid properties , has come from spectroscopic studies of a single linear molecule ( e.g. , ocs ) embedded in them.@xcite + despite the remarkable microscopic insight afforded by this approach , the presence of the embedded impurity , whose linear size is typically that of a few 4 atoms , is expected to alter drastically the structure of a cluster of such a small size . specifically , a significant fraction of the 4 atoms are predicted to bind to the foreign molecule , while the rest arrange in shells around it.@xcite this is very different from the featureless structure of a pristine 4 cluster.@xcite the question therefore remains open as to whether one could probe experimentally the superfluid properties of a finite assembly of 4 atoms in a way that does not make use of a foreign impurity , and preserves at least the full rotational invariance of the cluster ..
Please generate the next two sentences of the article | + aside from possible experiments on free standing clusters , with the aforementioned difficulties that they entail , one possibility that does not seem to have been given much consideration so far is that of studying 4 clusters enclosed in nanometer size cavities , e.g. , those of a suitably chosen porous material .
for example , one could think of adsorbing 4 inside zeolites , whose pore diameter is typically of the order of a nm , and therefore may accommodate clusters of a few atoms . |
9,257 | Suppose that you have an abstract for a scientific paper: with the advent of high analysis technology in detecting the gamow - teller ( gt ) excited states beyond one nucleon emission threshold , the quenching of the gt strength to the ikeda sum rule seems to be recovered by the high - lying gt states .
moreover , in some nuclei , the stronger gt peaks than any other peaks appear explicitly in the high - lying excited states .
we address that these high - lying gt excited states stems from the smearing of the fermi surface by the increase of the chemical potential owing to the deformation within a framework of the deformed quasi - particle random phase approximation ( dqrpa ) .
detailed mechanism leading to the smearing is discussed , and comparisons to the available experimental data are shown to explain the strong peaks on the high - lying gt excited states in a satisfactory manner .
the deformation in nuclei becomes more important than last decades with the recent development of rare isotope ( ri ) accelerator facilities , from which one may perform lots of challenging experiments related to the ri nuclei .
most of them are thought to be deformed more or less .
they are usually produced in the successive nuclear capture reactions in the cosmos , _
i.e. _ slow- and rapid- process , presumed to be occurred , respectively , at the initial and explosive stage of stellar evolution , such as supernovae ( sne ) explosion .
although they decay fractions of a second , they imprint their existence on the nuclear abundances of stars @xcite . another interesting nuclear process is the neutrino ( @xmath0)-process in the sne explosion which is treated as one of important nuclear processes for the nucleosynthesis , in particular , of the neutron - deficient nuclei , such as @xmath1la and @xmath2ta @xcite . here
@xmath2ta is a well known deformed nucleus .
since the neutrinos emitted from a proto - neutron star may have tens of mev energy high enough to excite the deformed nuclei , one needs to understand more precisely the high - lying excited states....
And you have already written the first three sentences of the full article: 99 t. hayakawa , n. iwamoto , t. shimizu , t. kajino , h. umeda , and k. nomoto , phys .
lett . * 93 * , 161102 ( 2004 ) .
a. heger , e. kolbe , w.c ..
Please generate the next two sentences of the article | haxton , k. langanke , g. martinez - pinedo and s.e .
woosley , phys . |
9,258 | Suppose that you have an abstract for a scientific paper: we present a microscopic quantum theory of intersubband polarons , quasiparticles originated from the coupling between intersubband transitions and longitudinal optical phonons . to this aim we develop a second quantized theory taking into account both the frhlich interaction between phonons and intersubband transitions and the coulomb interaction between the intersubband transitions themselves .
our results show that the coupling between the phonons and the intersubband transitions is extremely intense , thanks both to the collective nature of the intersubband excitations and to the natural tight confinement of optical phonons .
not only the coupling is strong enough to spectroscopically resolve the resonant splitting between the modes ( strong coupling regime ) , but it can become comparable to the bare frequency of the excitations ( ultrastrong coupling regime ) .
we thus predict the possibility to exploit intersubband polarons both for applied optoelectronic research , where a precise control of the phonon resonances is needed , and also to observe fundamental quantum vacuum physics , typical of the ultrastrong coupling regime . .
And you have already written the first three sentences of the full article: the theory of polarons , the quasiparticles describing electrons in a polarizable medium , dates back to the early days of quantum theory @xcite , and it has been an active field of research ever since @xcite . in this paper
we will develop a microscopic theory of intersubband polarons , that is , a theory of intersubband transitions coupled to longitudinal optical ( lo ) phonons in semiconductor quantum wells .
the coupling between intersubband transitions and lo - phonons is relevant for a number of optoelectronic applications , as it determines the lifetime of carriers in excited subbands @xcite . in particular a precise knowledge of lo - phonons intersubband scattering rates.
Please generate the next two sentences of the article | is important in the engineering of heterostructures for quantum cascade lasers @xcite .
normally optoelectronic devices are designed to avoid being in resonance with optical phonon transitions , due to the high absorption between transverse and longitudinal optical phonon frequencies ( restrahlen band ) . |
9,259 | Suppose that you have an abstract for a scientific paper: radio frequency ( rf ) energy harvesting and transfer techniques have recently become alternative methods to power the next generation of wireless networks .
as this emerging technology enables proactive replenishment of wireless devices , it is advantageous in supporting applications with quality - of - service ( qos ) requirement .
this article focuses on the resource allocation issues in wireless networks with rf energy harvesting capability , referred to as rf energy harvesting networks ( rf - ehns ) .
first , we present an overview of the rf - ehns , followed by a review of a variety of issues regarding resource allocation .
then , we present a case study of designing in the receiver operation policy , which is of paramount importance in the rf - ehns .
we focus on qos support and service differentiation , which have not been addressed by previous literatures .
furthermore , we outline some open research directions . .
And you have already written the first three sentences of the full article: recently , there has been an upsurge of research interests in radio frequency ( rf ) energy harvesting / scavenging technique ( see @xcite and references therein ) , which is the capability of converting the received rf signals into electricity .
this technique has become a promising solution to power energy - constrained wireless networks .
conventionally , the energy - constrained wireless networks , such as wireless sensor networks , have a limited lifetime , which significantly confines the network performance . in contrast.
Please generate the next two sentences of the article | , an rf energy harvesting network ( rf - ehn ) can have power supply from a radio environment .
consequently , rf - ehns have found their applications quickly in various forms , such as wireless sensor networks @xcite , wireless body networks @xcite , and wireless charging systems . |
9,260 | Suppose that you have an abstract for a scientific paper: a discontinuous generalization of the standard map , which arises naturally as the dynamics of a periodically kicked particle in a one dimensional infinite square well potential , is examined .
existence of competing length scales , namely the width of the well and the wavelength of the external field , introduce novel dynamical behaviour .
deterministic chaos induced diffusion is observed for weak field strengths as the length scales do not match .
this is related to an abrupt breakdown of rotationally invariant curves and in particular kam tori .
an approximate stability theory is derived wherein the usual standard map is a point of `` bifurcation '' .
+ pacs number(s ) : 05.45ac , 45.05.+x , 47.52.+j + keywords : chaos .
And you have already written the first three sentences of the full article: the construction and study of area preserving mappings has led to a deeper understanding of apparently complex dynamics , especially of hamiltonian chaos .
the maps range from abstract models @xcite such as the cat maps and the baker map to more generic ones .
one of the most well studied of such generic mappings is the standard map @xcite , which has also been investigated extensively in its quantum version @xcite ..
Please generate the next two sentences of the article | the classical map on the cylinder displays a range of dynamical behaviours , and when completely chaotic , diffusive random walks in momentum take place .
recent experiments using trapped ultra - cold sodium atoms in pulsed laser fields have probed this model , as a kicked rotator , and verified the central phenomenon of quantum localization of momentum diffusion @xcite . in this letter |
9,261 | Suppose that you have an abstract for a scientific paper: we report scattering lengths for the @xmath0 , @xmath1 and @xmath2 adiabatic molecular potentials relevant to collisions of two metastable @xmath3 helium atoms as a function of the uncertainty in these potentials .
these scattering lengths are used to calculate experimentally observable scattering lengths , elastic cross sections and inelastic rates for any combination of states of the colliding atoms , at temperatures where the wigner threshold approximation is valid .
# 1#2 # 1#2#3 # 1#2#3 # 1#2 # 1#2#3 # 1#2 .
And you have already written the first three sentences of the full article: metastable helium has been the subject of many experimental investigations at cold and ultracold temperatures .
these include various methods of laser cooling and trapping , production of an intense beam @xcite , optical collisions in magneto - optical traps and measurements of two - body trap loss rates , including that due to penning ionization , photoassociation spectroscopy @xcite and magnetostatic trapping @xcite .
there have also been several theoretical studies ..
Please generate the next two sentences of the article | much of this interest has been stimulated by the prospect of obtaining a bose - einstein condensate with spin - polarized metastable helium @xmath3 atoms @xcite ; a quest successfully realized very recently @xcite .
the penning ionization ( pi ) and associative ionization ( ai ) processes , @xmath4 have high threshold rates in an unpolarized gas and limit the achievable density of trapped atoms . here |
9,262 | Suppose that you have an abstract for a scientific paper: * spin qubits hosted in silicon ( si ) quantum dots ( qd ) are attractive due to their exceptionally long coherence times and compatibility with the silicon transistor platform . to achieve electrical control of spins for qubit scalability
, recent experiments have utilized gradient magnetic fields from integrated micro - magnets to produce an extrinsic coupling between spin and charge , thereby electrically driving electron spin resonance ( esr ) .
however , spins in silicon qds experience a complex interplay between spin , charge , and valley degrees of freedom , influenced by the atomic scale details of the confining interface . here , we report experimental observation of a valley dependent anisotropic spin splitting in a si qd with an integrated micro - magnet and an external magnetic field .
we show by atomistic calculations that the spin - orbit interaction ( soi ) , which is often ignored in bulk silicon , plays a major role in the measured anisotropy .
moreover , inhomogeneities such as interface steps strongly affect the spin splittings and their valley dependence .
this atomic - scale understanding of the intrinsic and extrinsic factors controlling the valley dependent spin properties is a key requirement for successful manipulation of quantum information in si qds . *
[ fi1 ] how microscopic electronic spins in solids are affected by the crystal and interfacial symmetries has been a topic of great interest over the past few decades and has found potential applications in spin - based electronics and computation @xcite . while the coupling between spin and orbital degrees of freedom has been extensively studied ,
the interplay between spin and the momentum space valley degree of freedom is a topic of recent interest .
this spin - valley interaction is observed both in the exotic class of newly found two - dimensional materials @xcite and in silicon @xcite the old friend of the electronics industry .
progress in silicon qubits in the last few years has come with the....
And you have already written the first three sentences of the full article: for the theoretical calculations , we used a large scale atomistic tight binding approach with spin resolved sp@xmath77d@xmath78s * atomic orbitals with nearest neighbor interactions@xcite .
typical simulation domains comprise of 1.5 - 2 million atoms to capture realistic sized dots .
spin - orbit interactions are directly included in the hamiltonian as a matrix element between p - orbitals following the prescription of chadi @xcite ..
Please generate the next two sentences of the article | the advantage of this approach is that no additional fitting parameters are needed to capture various types of soi such as rashba and dresselhaus soi in contrast to k.p theory .
we introduce monoatomic steps as a source of non - ideality consistent with other works@xcite . |
9,263 | Suppose that you have an abstract for a scientific paper: the decay mode @xmath0 is proposed in order to experimentally identify the effects of the coupling of charmonium states to the continuum @xmath1 states . to have a better understanding of such a two - photon decay process , in this work
we restrict ourselves to investigate the contribution of the discrete part , in which the photons are mainly produced via the intermediate states @xmath2 . besides calculating the resonance contributions of @xmath3
, we also take into account the contributions of the higher excited states @xmath4 and the interference effect among the @xmath5 and @xmath6 states .
we find that the contribution of the @xmath6 states and the interference terms to the total decay width is very tiny .
however , for specific regions of the dalitz plot , off the resonance peaks , we find that these contributions are sizable and should also be accounted for .
we also provide the photon spectrum and study the polarization of @xmath7 . .
And you have already written the first three sentences of the full article: electromagnetic processes have always provided invaluable probes of the strong interactions , the most prominent example being the deep inelastic scattering experiments in the early 1970s which eventually established qcd as the fundamental theory of the strong interactions . among the current challenges of qcd
is the description of the plethora of charmoniumlike states discovered during the past years , the so - called xyz " ( for reviews see , e.g. , refs .
@xcite ) , that lie above the @xmath1 threshold , and do not fit potential model expectations ..
Please generate the next two sentences of the article | it is widely accepted that the effects of the coupling of a core charmonium , namely , a mainly @xmath8 bound state , to a @xmath1 meson pair , the so - called coupled - channel effects , are an important ingredient to understand those states .
we shall call the latter continuum states and the former valence states |
9,264 | Suppose that you have an abstract for a scientific paper: using density - functional perturbation theory and the grneisen formalism , we directly calculate the linear thermal expansion coefficients ( tecs ) of a hexagonal bulk system mos@xmath0 in the crystallographic @xmath1 and @xmath2 directions .
the tec calculation depends critically on the evaluation of a temperature ( @xmath3 ) dependent quantity @xmath4 , which is the integral of the product of heat capacity and @xmath5 , of frequency @xmath6 and strain type @xmath7 , where @xmath5 is the phonon density of states weighted by the grneisen parameters .
we show that to determine the linear tecs we may use minimally two uniaxial strains in the @xmath8 , and either @xmath9 or @xmath10 direction .
however , a uniaxial strain in either @xmath9 and @xmath10 direction drastically reduces the symmetry of the crystal from a hexagonal one to a base - centered orthorhombic one .
we propose to use an efficient and accurate symmetry - preserving biaxial strain in the @xmath11 plane to derive the same result for @xmath12 .
we highlight that the grneisen parameter associated with a biaxial strain may not be the same as the average of grneisen parameters associated with two separate uniaxial strains in the @xmath9 and @xmath10 directions due to possible preservation of degeneracies of the phonon modes under a biaxial deformation .
large anisotropy of tecs is observed where the linear tec in the @xmath2 direction is about @xmath13 times larger than that in the @xmath1 or @xmath14 direction at high temperatures .
our theoretical tec results are compared with experiment . the symmetry - preserving approach adopted here
may be applied to a broad class of two lattice - parameter systems such as hexagonal , trigonal , and tetragonal systems , which allows many complicated systems to be treated on a first - principles level . .
And you have already written the first three sentences of the full article: transition metal dichalcogenides ( tmds ) @xmath15 , where @xmath3 is a transition metal such as w and mo , and @xmath16 is a chalcogen such as s , se , and te , receive considerable attention due to their important mechanical and electronic properties@xcite .
molybdenum disulfide mos@xmath0 , a prototypical example of tmds , is a layered system where mo atoms form hexagonal layers@xcite .
each of the mo hexagonal layer is sandwiched between two similar lattices of s atoms , forming a trilayer@xcite ..
Please generate the next two sentences of the article | the atoms within each trilayer are held together by strong covalent bonds , while the trilayers of mos@xmath0 interact primarily through weak van der waals interactions .
it is this sandwiched structure that endows mos@xmath0 with the important mechanical properties for solid lubricants@xcite . |
9,265 | Suppose that you have an abstract for a scientific paper: based on high - resolution two - dimensional hydrodynamic simulations , we show that the bulk gas motions in a cluster of galaxies , which are naturally expected during the process of hierarchical structure formation of the universe , have a serous impact on the core .
we found that the bulk gas motions represented by acoustic - gravity waves create local but strong turbulence , which reproduces the complicated x - ray structures recently observed in cluster cores .
moreover , if the wave amplitude is large enough , they can suppress the radiative cooling of the cores .
contrary to the previous studies , the heating is operated by the turbulence , not weak shocks .
the turbulence could be detected in near - future space x - ray missions such as _ astro - e2_. .
And you have already written the first three sentences of the full article: clusters of galaxies are the largest gravitationally bound and collapsed systems in the universe .
they are filled with x - ray emitted hot gas with the temperature of @xmath010 kev .
high - resolution x - ray observations have revealed that the hot gas in many cluster cores is not smoothly distributed ( e.g. * ? ? ?.
Please generate the next two sentences of the article | * ; * ? ? ?
, we define the cluster cores as the dense regions within @xmath1300 kpc from the cluster centers . |
9,266 | Suppose that you have an abstract for a scientific paper: we discuss the reference time @xmath0 of afterglow light curves in the context of the standard internal - external shock model .
the decay index of early afterglow is very sensitive to the reference time one chooses . in order to understand the nature of early afterglow , it is essential to take a correct reference time .
our simple analytic model provides a framework to understand special relativistic effects involved in early afterglow phase .
we evaluate light curves of reverse shock emission as well as those of forward shock emission , based on full hydrodynamic calculations .
we show that the reference time does not shift significantly even in the thick shell case . for external shock emission components ,
measuring times from the beginning of the prompt emission is a good approximation and it does not cause an early steep decay . in the thin shell case , the energy transfer time from fireball ejecta to ambient medium typically extends to thousands of seconds .
this might be related to the shallow decay phases observed in early x - ray afterglow at least for some bursts . .
And you have already written the first three sentences of the full article: it is well known that gamma - ray burst ( grb ) afterglow decays as a power - law @xmath1 .
the temporal decay index @xmath2 , together with the spectral index , provides us precious information about grb jets and their environment . in the pre - swift era
afterglow observations start typically a few hours after a burst . in such a late phase ,.
Please generate the next two sentences of the article | the decay index is insensitive to the choice of the reference time @xmath0 , and grb trigger time is often used in afterglow modelings .
the multi - wavelength observatory swift was launched in nov 2004 . |
9,267 | Suppose that you have an abstract for a scientific paper: we perform a simplified ethernet traffic simulation in order to clarify the physical mechanism of the phase transition behavior which has been experimentally observed in the flow density fluctuation of internet traffic . in one
phase traffics from nodes connected with an ethernet cable are mixed , and in the other phase , the nodes alternately send bursts of packets .
the competition of sending packets among nodes and the binary exponential back - off algorithm are revealed to play important roles in producing @xmath0 fluctuations at the critical point .
phase transition ; internet traffic ; numerical simulation , .
And you have already written the first three sentences of the full article: the internet can be viewed as an autonomous system in which the nodes are heterogeneously connected without any central control . in the internet ,
the unit of information is a packet , and many researchers have been investigating the statistical properties of packet density fluctuations . in 1994
leland et ..
Please generate the next two sentences of the article | al analyzed the time series of packet flow density in the internet , and showed the existence of the @xmath0 type fluctuation@xcite .
similar to the packet flow fluctuation , csabai reported that the time series of round trip time ( rtt ) exhibits the self - similarity in certain path of the internet @xcite . following these pioneering works , |
9,268 | Suppose that you have an abstract for a scientific paper: we investigate superfluid properties of a one - component fermi gas with a uniaxially anisotropic @xmath0-wave pairing interaction , @xmath1 ( where @xmath2 ( @xmath3 is a @xmath4-wave pairing interaction ) .
this type of interaction is considered to be realized in a @xmath5k fermi gas . including pairing fluctuations within a strong - coupling @xmath6-matrix theory , we determine the @xmath7-wave superfluid phase transition temperature @xmath8 , as well as the other phase transition temperature @xmath9 ( @xmath10 ) , below which the superfluid order parameter has the @xmath11-wave symmetry . in the normal state near @xmath8
, @xmath7-wave pairing fluctuations are shown to induce an anisotropic pseudogap phenomenon , where a dip structure in the angle - resolved density of states around @xmath12 is the most remarkable in the @xmath7 direction . in the @xmath7-wave superfluid phase ( @xmath13 ) , while the pseudogap in the @xmath7 direction continuously changes to the superfluid gap , the pseudogap in the perpendicular direction to the @xmath7 axis is found to continue developing , because of enhanced @xmath14-wave and @xmath15-wave pairing fluctuations around the node of the @xmath7-wave superfluid order parameter . since pairing fluctuations
are always suppressed in the isotropic @xmath16-wave superfluid state , this phenomenon is peculiar to an unconventional fermi superfluid with a nodal superfluid order parameter .
since the @xmath0-wave fermi superfluid is the most promising non @xmath16-wave pairing state in an ultracold fermi gas , our results would contribute to understanding how the anisotropic pairing fluctuations , as well as the existence of plural superfluid phases , affect many - body properties of this unconventional fermi superfluid . .
And you have already written the first three sentences of the full article: an interesting feature of a non @xmath16-wave fermi condensate is that it may have plural superfluid phases , originating from active orbital and/or spin degrees of freedom . indeed
, this possibility has experimentally been confirmed in various fermi superfluid systems , such as heavy fermion superconductor upt@xmath17 @xcite , as well as superfluid liquid @xmath18he @xcite .
however , the pairing symmetry that has already been realized is still only the simplest @xmath16-wave one in cold fermi gas physics @xcite ..
Please generate the next two sentences of the article | thus , going beyond this situation is a crucial challenge in this research field . in this regard ,
a @xmath0-wave superfluid fermi gas is a strong candidate , and the possibility of this spin - triplet pairing state has extensively been discussed both experimentally @xcite and theoretically @xcite . |
9,269 | Suppose that you have an abstract for a scientific paper: we obtain the spectra of excited heavy baryons containing one heavy quark by quantizing the exactly - solved heavy meson bound states to skyrme soliton .
the results are comparable to the recent experimental observations and quark model predictions , and are consistent with the heavy quark spin symmetry .
however , somewhat large dependence of the results on the heavy quark mass strongly calls for the incorporation of the soliton - recoil effects . .
And you have already written the first three sentences of the full article: up to the present , most ground state charm baryons containing one @xmath0-quark , from @xmath1 to @xmath2 , have been observed @xcite .
there have been much efforts to find excited charm baryons and recently the experimental evidences for @xmath3 @xcite , @xmath4 and @xmath5 @xcite are reported .
although their quantum numbers are not identified yet , the spin - parity of the @xmath6 is interpreted as @xmath7 , and @xmath8 and @xmath5 decaying to @xmath9 are regarded as candidates for @xmath10 and @xmath11 excited states , respectively , in accordance with the quark model predictions @xcite ..
Please generate the next two sentences of the article | the small mass splittings between @xmath6 and @xmath12 and between @xmath13 and @xmath14 are consistent with the heavy quark spin symmetry @xcite , according to which the hadrons come in degenerate doublets with total spin @xmath15 ( unless @xmath16 , the total angular momentum of the light degrees of freedom , is zero ) in the limit of the heavy quark mass going to infinity .
on the other hand , the excited heavy baryons have been extensively studied not only in various quark / bag models @xcite but also in heavy hadron chiral perturbation theory @xcite and in the bound state approach of the skyrme model @xcite . in the bound state model , |
9,270 | Suppose that you have an abstract for a scientific paper: we show that the frequency spectrum of two dimensional photonic crystals is strongly influenced by fano resonances which can be excited already in the linear array of dielectric cylinders .
to support this claim , we calculate the transmission of electromagnetic wave through linear array of dielectric cylinders and show that frequencies of observed fano resonances coincides with position of narrow frequency bands found in the spectra of corresponding two - dimensional photonic crystals .
split of frequency band or overlap of two bands , observed in the band structure of photonic structures are also associated with fano resonances . .
And you have already written the first three sentences of the full article: frequency spectrum of photonic crystals consists of large number of continuous bands .
this is a direct consequence of spatial periodicity of the permittivity @xmath0 which defines the structure . in the limit of infinitesimally small variations of the permittivity
, all frequency bands could be constructed from the dispersion relation of electromagnetic wave in homogeneous medium by reduction of the momenta @xmath1 to the first brillouin zone @xcite . with increasing permittivity contrast , frequency gaps open at the edges of brillouin zone @xcite ..
Please generate the next two sentences of the article | we will call the resulting frequency bands periodic ( @xmath2 ) bands . for higher permittivity contrast , the frequency spectrum is more complicated .
it contains , besides the @xmath2 bands , also other , usually very narrow ( almost dispersionless ) frequency bands . as an example |
9,271 | Suppose that you have an abstract for a scientific paper: the sagdeev potential technique has been considered to find the necessary condition for the existence as well as the polarity of dust ion acoustic solitary structures at @xmath0 , in an unmagnetized nonthermal plasma consisting of negatively charged dust grains , adiabatic positive ions and nonthermal electrons , where @xmath1 is the smallest possible value of the mach number @xmath2 .
depending on the analytical theory , a compositional parameter space showing the nature of existence of solitary structures at @xmath0 has been presented .
the compositional parameter space clearly indicates the upper bounds of the nonthermal parameter ( @xmath3 ) associated with the nonthermal distribution of electrons for the existence of negative and positive potential solitons at @xmath0 .
the compositional parameter space also shows that the present system does not support the coexistence of both negative and positive solitons at @xmath0 .
a critical value of the nonthermal parameter ( @xmath4 ) , which acts as sink of negative solitons and the source of positive solitons at @xmath0 , has been found . however , no solitary wave is possible at @xmath4 .
the compositional parameter space again shows that the present system supports the negative potential double layer along the curve @xmath5 in @xmath6-parametric plane provided that @xmath7 , i.e. , for each @xmath8 lying within the interval @xmath9 , there exists one and only one @xmath10 of @xmath3 such that one can get negative potential double layer at @xmath0 when @xmath5 , where @xmath8 is the ratio of unperturbed number density of nonthermal electrons to that of ions . from the compositional parameter space
, it has been observed that the negative potential solitons at @xmath0 are separated by the curve @xmath5 . a finite jump between amplitudes of negative potential solitons separated by the curve @xmath5 has been observed .
the effect of the parameters on the amplitude of the solitary structures have been discussed . .
And you have already written the first three sentences of the full article: in the last few decades dusty plasma attracts the researchers most , not only because of different types of wave propagation in dusty plasma due to their involvement in the study of astrophysical and space environments but also for its great variety of new phenomena associated with waves and instabilities.@xcite dusty plasmas essentially consists of fairly massive , charged particulates in addition to electrons and ions in the usual two component plasma .
acoustic wave modes in dusty plasma have received a great deal of attention since the last decade .
depending on different time scales , there can exists two or more acoustic waves in a typical dusty plasma ..
Please generate the next two sentences of the article | dust acoustic ( da ) and dust ion - acoustic ( dia ) waves are two such acoustic waves in a plasma containing electrons , ions , and charged dust grains .
shukla and silin @xcite were the first to show that due to the quasi neutrality condition @xmath11 and the strong inequality @xmath12 ( @xmath13 , @xmath14 , and @xmath15 are , respectively , the number density of electrons , ions , and dust particle , where @xmath16 is the number of electrons residing on the dust grain surface ) , a dusty plasma ( with negatively charged static dust grains ) supports low - frequency dia waves with phase velocity much smaller ( larger ) than electron ( ion ) thermal velocity . in case of long wavelength limit |
9,272 | Suppose that you have an abstract for a scientific paper: maximum likelihood estimation of gaussian mixture models with different class - specific covariance matrices is known to be problematic .
this is due to the unboundedness of the likelihood , together with the presence of spurious maximizers .
existing methods to bypass this obstacle are based on the fact that unboundedness is avoided if the eigenvalues of the covariance matrices are bounded away from zero .
this can be done imposing some constraints on the covariance matrices , i.e. by incorporating _ a priori _ information on the covariance structure of the mixture components .
the present work introduces a constrained equivariant approach , where the class conditional covariance matrices are shrunk towards a pre - specified matrix @xmath0 data - driven choices of the matrix @xmath1 when _ a priori _ information is not available , and the optimal amount of shrinkage are investigated .
the effectiveness of the proposal is evaluated on the basis of a simulation study and an empirical example . + * keywords * : model based clustering , gaussian mixture models , equivariant estimators .
And you have already written the first three sentences of the full article: let @xmath2 be a @xmath3-variate random variable following a gaussian mixture model ( gmm ) with density @xmath4 where the @xmath5 s are the mixing proportions , with @xmath6 @xmath7 and @xmath8 , and the component @xmath9 represents the density of a @xmath3-variate normal distribution with mean vector @xmath10 and covariance matrix @xmath11 ; furthermore , let us indicate the set of model parameters with @xmath12 and the parameter space with @xmath13 where the symbol @xmath14 refers to lwner ordering on symmetric matrices and , in this case , is equivalent to requiring that @xmath11 be positive definite .
the gmm is frequently used to classify a sample of observations .
the idea is to consider the sample as drawn from a heterogeneous population where each sub - population is described by one component of the mixture . in other terms.
Please generate the next two sentences of the article | , each observation is assumed to come from one of the @xmath15 different groups characterized by the mixture components .
the observations are classified into the groups by computing the posterior probabilities @xmath16 and assigning each observation to the group with the largest posterior probability . |
9,273 | Suppose that you have an abstract for a scientific paper: we examine the behavior of a non gaussian state like noon state under phase insensitive amplification .
we derive analytical result for the density matrix of the noon state for arbitrary gain of the amplifier .
we consider cases of both symmetric and antisymmetric amplification of the two modes of the noon state .
we quantitatively evaluate the loss of entanglement by the amplifier in terms of the logarithmic negativity parameter .
we find that noon states are more robust than their gaussian counterparts . .
And you have already written the first three sentences of the full article: among the continuous variable ( cv ) entangled states @xcite , non gaussian states are generally believed to possess much more robust entanglement vis a vis the gaussian states states characterized by a gaussian quasi probability distributions and hence by their first and second moments .
though mathematically not as well understood as the gaussian states @xcite in so far as their entanglement properties are concerned , non gaussian states , by virtue of the robustness of their entanglement have in recent years emerged as strong contenders for potential applications in quantum information technology .
the fact that the non gaussian states are defined by what they are not makes a general discussion of their entanglement properties impossible and one is forced to restrict oneself to sub families of non gaussian states such as states obtained by adding or subtracting a fixed number of photons to gaussian states @xcite and forming suitable superpositions thereof ..
Please generate the next two sentences of the article | one such widely discussed family of non gaussian states parameterized by an integer @xmath0 is the family of noon states @xcite @xmath1.\ ] ] these states , similar in structure to the epr states , have attracted much attention in recent years and can be viewed as a two mode state consisting of a superposition of states containing @xmath0 photons in one mode and none in the other and vice versa .
schemes for reliable production of such states have been proposed @xcite and their usefulness as a practical tool in making super - precision measurements in optical interferometry , atomic spectroscopy and in sensing extremely small magnetic fields than hitherto possible have been highlighted @xcite . |
9,274 | Suppose that you have an abstract for a scientific paper: technological applications of many - body structures that emerge in gated devices under minimal control are largely unexplored . here
we show how emergent wigner crystals in a semiconductor quantum wire can facilitate a pivotal requirement for a scalable quantum computer , namely transmitting quantum information encoded in spins faithfully over a distance of micrometers .
the fidelity of the transmission is remarkably high , faster than the relevant decohering effects , independent of the details of the spatial charge configuration in the wire , and realizable in dilution refrigerator temperatures .
the transfer can evidence near unitary many - body nonequilibrium dynamics hitherto unseen in a solid - state device .
it could also be useful in spintronics as a method for pure spin current over a distance without charge movement .
spin chains can facilitate several important technological applications such as pure spin currents in non - itinerant systems @xcite , quantum state transfer @xcite and quantum gates @xcite .
most of the above applications are facilitated by a nearly unitary dynamics of the spin chain .
such dynamics is not only interesting for potential quantum technology @xcite but also fundamentally important to address questions of equilibration , quantum thermodynamics and information propagation @xcite .
thus , the physical realization of artificial spin chains that have the potential for long time unitary dynamics is an important quest
they have been realized only very recently , and exclusively in atomic physics systems : in cold atom systems @xcite , ion traps @xcite and rydberg systems @xcite . in the realm of solid - state , on the other hand , nonequilibrium dynamics of engineered spin chains is far from unitary and primarily driven by equilibration / relaxation @xcite . although some bulk magnetic materials @xcite , nv centre chains @xcite and josephson junction arrays @xcite hold the potential for long chain unitary dynamics , that is still somewhat....
And you have already written the first three sentences of the full article: the trapping potential used in this study is @xmath87 , \nonumber\end{aligned}\ ] ] where @xmath88 , @xmath89 are defined in the main text .
an illustration of this potential is given in fig .
[ fig : potential ] . the external barrier heights in @xmath88 were set to be @xmath90mev and the length of the system set to @xmath91 m as discussed in the main text ..
Please generate the next two sentences of the article | we choose a value of @xmath16 such that the the degeneracy between the two possible ground states @xmath92 and @xmath93 is lifted sufficiently with respect to the temperature , where @xmath92 is the mirror inversion of @xmath93 about the @xmath94-axis .
the probability of excitation from @xmath92 to @xmath93 at temperature @xmath64 in the presence of the symmetry breaking potential @xmath95 is roughly @xmath96 . |
9,275 | Suppose that you have an abstract for a scientific paper: new parameter - sets of the semi - realistic nucleon - nucleon interaction are developed , by modifying the m3y interaction but maintaining the tensor channels and the longest - range central channels .
the modification is made so as to reproduce microscopic results of neutron - matter energies , in addition to the measured binding energies of doubly magic nuclei including @xmath0sn and the even - odd mass differences of the @xmath1 and @xmath2 nuclei in the self - consistent mean - field calculations .
separation energies of the proton- or neutron - magic nuclei are shown to be in fair agreement with the experimental data . with the new parameter - sets m3y - p6 and p7 , the isotropic spin - saturated symmetric nuclear matter remains stable in the density range as wide as @xmath3 , while keeping desirable results of the previous parameter - set on finite nuclei .
isotope shifts of the pb nuclei and tensor - force effects on shell structure are discussed . .
And you have already written the first three sentences of the full article: as exotic natures of unstable nuclei such as the new magic numbers and the neutron halos are disclosed by experiments , microscopic studies based on the nucleon - nucleon ( @xmath4 ) interaction become even more desired in nuclear structure physics . while the fully microscopic @xmath4 ( and @xmath5 ) interaction is still too complicated to cover large volume of nuclei in the periodic table despite significant progress @xcite , the semi - realistic @xmath4 interactions have been developed @xcite by modifying the michigan 3-range yukawa ( m3y ) interaction @xcite , which was originated from brueckner s @xmath6-matrix at the nuclear surface and expressed by the yukawa functions .
the modification has been made so that the saturation and the spin - orbit ( @xmath7 ) splitting should be reproduced within the mean - field approximation ( mfa ) .
owing to the recently developed numerical methods @xcite , self - consistent calculations in the mfa @xcite and in the random - phase approximation ( rpa ) @xcite have been implemented using the semi - realistic interactions . among the advantages of the m3y - type semi - realistic interactions.
Please generate the next two sentences of the article | is that they contain realistic tensor channels as well as correct longest - range central channels originating from the one - pion exchange , which have been pointed out to play significant roles in @xmath8- or @xmath9-dependence of the shell structure @xcite .
the semi - realistic interactions are suitable to investigate effects of these channels within the self - consistent mfa and rpa @xcite . while the parameter - sets of the m3y - type interactions in refs . |
9,276 | Suppose that you have an abstract for a scientific paper: we discuss the stochastic mean - field theory ( smft ) method which is a new approach for describing disordered bose systems in the thermodynamic limit including localization and dimensional effects .
we explicate the method in detail and apply it to the disordered bose - hubbard model at finite temperature , with on - site box disorder , as well as experimentally relevant unbounded speckle disorder .
we find that disorder - induced condensation and reentrant behavior at constant filling are only possible at low temperatures , beyond the reach of current experiments @xcite .
including off - diagonal hopping disorder as well , we investigate its effect on the phase diagram in addition to pure on - site disorder . to make contact to present experiments on a quantitative level
, we also combine smft with an lda approach and obtain the condensate fraction in the presence of an external trapping potential . .
And you have already written the first three sentences of the full article: the interplay between disorder and interactions in bose systems has been a vital field of research in condensed matter both in theory and experiment .
the line of investigation was mainly initiated by the seminal work of fisher et al.@xcite , who first provided a detailed study of localization of interacting bosons in a random potential , which led to the notion of the superfluid - insulator transition and the bose glass ( bg ) .
while disorder effects in fermi systems are relevant to a broad range of experimentally accessible scenarios like correlated electron systems , the status was less diverse for bose systems for a considerable time period , as superfluid @xmath0he situated in random pores of vycor had been the predominant setup which could be studies with sufficient precision @xcite ..
Please generate the next two sentences of the article | this changed dramatically when the realization of the superfluid - mott insulator transition of ultracold bosonic atoms in an optical lattice opened up a new field of investigation @xcite .
in particular , optical lattices provide a relatively pure and tunable simulation of effective models used to describe solid state systems@xcite , where effects like disorder can also be realized in a controlled manner . |
9,277 | Suppose that you have an abstract for a scientific paper: given two convex polytopes , the join , the cartesian product and the direct sum of them are well understood . in this paper
we extend these three kinds of products to abstract polytopes and introduce a new product , called the topological product , which also arises in a natural way .
we show that these products have unique prime factorization theorems .
we use this to compute the automorphism group of a product in terms of the automorphism groups of the factors and show that ( non trivial ) products are almost never regular or two - orbit polytopes .
we finish the paper by studying the monodromy group of a product , show that such a group is always an extension of a symmetric group , and give some examples in which this extension splits . .
And you have already written the first three sentences of the full article: in school we all dealt , in one way or another , with solids such as prisms and pyramids , but maybe also with bipyramids .
the aim of this paper is to generalize these solids as different products of abstract polytopes , and study their symmetry and combinatorial properties .
prisms , pyramids and bipyramids over polygons ( see figure [ pentagons ] ) can be seen as a product of a polygon by either a segment or a point . however , these are three different kinds of products . while prisms are the cartesian product of a segment with a polygon , pyramids are the join product of a point with a polygon and bipyramids are the direct product of a segment with a polygon . in the theory of convex polytopes the generalization of these three notions.
Please generate the next two sentences of the article | are the cartesian product , the join product and the direct sum , respectively ( @xcite ) . given two convex polytopes @xmath0 and @xmath1 ,
their products are defined as follows . |
9,278 | Suppose that you have an abstract for a scientific paper: x - rays from binaries in small , metal - deficient galaxies may have contributed significantly to the heating and reionization of the early universe .
we investigate this claim by studying blue compact dwarfs ( bcds ) as local analogues to these early galaxies .
we constrain the relation of the x - ray luminosity function ( xlf ) to the star - formation rate ( sfr ) using a bayesian approach applied to a sample of 25 bcds .
the functional form of the xlf is fixed to that found for near - solar metallicity galaxies and is used to find the probability distribution of the normalisation that relates x - ray luminosity to sfr .
our results suggest that the xlf normalisation for low metallicity bcds ( 12+log(o / h ) @xmath0 7.7 ) is not consistent with the xlf normalisation for galaxies with near solar metallicities , at a confidence level @xmath1 .
the xlf normalisation for the bcds is found to be @xmath2 , a factor of @xmath3 higher than for near solar metallicity galaxies .
simultaneous determination of the xlf normalisation and power law index result in estimates of @xmath4 and @xmath5 , respectively .
our results suggest a significant enhancement in the population of high - mass x - ray binaries in bcds compared to the near - solar metallicity galaxies .
this suggests that x - ray binaries could have been a significant source of heating in the early universe .
[ firstpage ] galaxies : blue compact dwarf stars : formation x - rays : galaxies .
And you have already written the first three sentences of the full article: x - rays may have played an important role in heating the early universe @xcite .
however , direct study of the sources that produced x - rays in the early universe is currently impractical due to their high redshifts . @xcite
have suggested that blue compact dwarf ( bcd ) galaxies may be local analogues of the x - ray producing , metal - deficient galaxies found in the early universe ..
Please generate the next two sentences of the article | the x - ray emission of bcds is dominated by point - like sources that are likely high - mass x - ray binaries ( hmxb ) @xcite .
recently @xcite , @xcite , and @xcite have reported enhanced production of x - ray binaries in low - metallicity , or extremely metal poor galaxies ( xmpg ) , relative to the star formation rate ( sfr ) . to further study this enhanced production , we analyse data from a sample of 25 metal - poor bcds . |
9,279 | Suppose that you have an abstract for a scientific paper: we investigate the properties of the inverse limit of the algebras of local unitary invariant polynomials of quantum systems containing various types of fermionic and/or bosonic particles as the dimensions of the single particle state spaces tend to infinity .
we show that the resulting algebras are free and present a combinatorial description of an algebraically independent generating set in terms of graphs .
these generating sets can be interpreted as minimal sets of polynomial entanglement measures distinguishing between states showing different nonclassical behaviour .
pter vrana department of theoretical physics , institute of physics + budapest university of technology and economics + h-1111 budapest , hungary ( ) .
And you have already written the first three sentences of the full article: one of the most important questions in quantum information theory is the classification of states containing inequivalent types of quantum correlations .
many results exist in the case when the parts of the composite system are effectively distinguishable , but much less is known in the case of identical particles .
when discussing entanglement at short scales , one can expect that indistinguishability of identical particles changes the nature of quantum correlations in a fundamental way ..
Please generate the next two sentences of the article | understanding such correlations and inequivalent types of entanglement of identical particles is also of great importance outside quantum information theory @xcite .
following recent success in describing the algebra of polynomial invariants under the local unitary group of multipartite quantum systems in the limiting case of large hilbert space dimensions @xcite , in this paper we turn to the question of finding a similar description when identical particles are present . |
9,280 | Suppose that you have an abstract for a scientific paper: a non - universal scalar mass supergravity type of model is explored where the first two generation of scalars and the third generation of sleptons may be very massive .
the lighter or vanishing third generation of squarks as well as higgs scalars at the unification scale cause the radiative electroweak symmetry breaking constraint to be less prohibitive .
thus , both fcnc / cp - violation problems as well as the naturalness problem are within control .
we identify a large slepton mass effect in the rge of @xmath0 ( for the down type of higgs ) that may turn the later negative at the electroweak scale even for a small @xmath1 .
a hyperbolic branch / focus point like effect is found for @xmath2 that may result in very light higgs spectra .
the lightest stable particle is dominantly a bino that pair annihilates via higgs exchange , giving rise to a wmap satisfied relic density region for all @xmath1 .
detection prospects of such lsps in the upcoming dark matter experiments both of direct and indirect types ( photon flux ) are interesting .
the higgs bosons and the third generation of squarks are light in this scenario and these may be easily probed besides charginos and neutralinos in the early runs of lhc .
+ pacs no : 04.65.+e , 13.40em , 14.60ef , 13.85.-t , 14.80.ly -1 cm 16.5 cm 21.5 cm -0.5 cm # 1 # 1 # 1 # 1 ( # 1,#2,#3)*#1 * , # 2 ( # 3)#1#2#3#4#1 * # 2 * , # 3 ( # 4 ) # 1#2#3jhep * # 1 * , # 3 ( # 2 ) # 1#2#3jhep * # 1 * , # 3 ( # 2 ) # 1#2#3phys .
rev .
d * # 1 * , # 3 ( # 2 ) # 1#2#3phys .
rev .
d * # 1 * , # 3 ( # 2 ) # 1#2#3phys .
rev .
lett . *
# 1 * , # 3 ( # 2 ) # 1#2#3phys .
rev .
lett . * # 1 * , # 3 ( # 2 ) # 1#2#3nucl .
phys .
b * # 1 * , # 3 ( # 2 ) # 1#2#3nucl .
phys .
b * # 1 * , # 3 ( # 2 ) # 1arxiv : hep - ph/#1 ( # 1,#2,#3)phys . rep .
( # 1,#2,#3 ) ( # 1,#2,#3)eur .
phys .
j. c ( # 1,#2,#3 ) 0_b_0 22 2 ^ 2_w 2m_z^2 2b2 v#1v_#1 # 1 ^ 0_#1 # 1m_#1 # 1m_#1 # 1m_^0_#1 # 1m_^+_#1 2wsec^2_w 2(g-2 ) _ = 11 # 1#2 #....
And you have already written the first three sentences of the full article: low energy supersymmetry ( susy)@xcite is one of the most active fields of research for physics beyond the standard model ( sm)@xcite . a minimal extension of the standard model when supersymmetry is incorporated is the minimal supersymmetric standard model ( mssm)@xcite that includes two higgs doublets .
the model however has a large number of susy breaking parameters and this motivates one into studying models with specific mechanisms for breaking susy .
the later involves high scale physics input and renormalization group analyses ..
Please generate the next two sentences of the article | this in general leads to a large reduction of the number of unknown parameters .
the minimal supergravity ( msugra)@xcite model is one of the well studied susy models . |
9,281 | Suppose that you have an abstract for a scientific paper: as part of the panoramic imaging survey of centaurus and sculptor ( pisces ) we report the discovery of a pair of faint dwarf galaxies ( cena - mm - dw1 and cena - mm - dw2 ) at a projected distance of @xmath090 kpc from the nearby elliptical galaxy ngc 5128 ( cena ) .
we measure a tip of the red giant branch distance to each dwarf , finding @[email protected] mpc for cena - mm - dw1 and @[email protected] mpc for cena - mm - dw2 , both of which are consistent with the distance to ngc 5128 .
a qualitative analysis of the color magnitude diagrams indicates stellar populations consisting of an old , metal - poor red giant branch ( @xmath312 gyr , [ fe / h]@[email protected] to @xmath41.9 ) .
in addition , cena - mm - dw1 seems to host an intermediate - age population as indicated by its candidate asymptotic giant branch stars .
the derived luminosities ( @xmath5 for cena - mm - dw1 and @xmath6 for cena - mm - dw2 ) and half - light radii ( @xmath7 kpc for cena - mm - dw1 and @xmath8 kpc for cena - mm - dw2 ) are consistent with those of local group dwarfs .
cena - mm - dw1 s low central surface brightness ( @xmath9 mag / arcsec@xmath10 ) places it among the faintest and most extended m31 satellites .
most intriguingly , cena - mm - dw1 and cena - mm - dw2 have a projected separation of only 3 arcmin ( @xmath11 kpc ) : we are possibly observing the first , faint satellite of a satellite in an external group of galaxies . .
And you have already written the first three sentences of the full article: the relative number and astrophysical properties of dwarf galaxies represent one of the major challenges to the widely accepted @xmath12+cold dark matter ( @xmath12cdm ) cosmological model of structure formation .
for instance , the predicted number of dm haloes around a milky way ( mw)-sized halo exceeds the observed number by at least an order of magnitude ( e.g. * ? ? ? * ; * ? ? ? * ) , and their central densities at a given mass are lower than inferred from simulations ( e.g. * ? ? ? * ; * ? ? ? * ) .
understanding these challenges has largely been left to studies of the local group ( lg ; with exceptions , e.g. * ? ? ?.
Please generate the next two sentences of the article | * ) where the faintest satellite galaxies can be discovered and studied in detail . however , a diversity of halo to halo substructure is expected due to varying accretion histories @xcite and inhomogeneous reionization @xcite ; it is also possible that the lg is an outlier in its satellite properties .
a systematic study of the faint satellite populations of a large number of galaxies in a variety of environments is critical before the @xmath12cdm picture of galaxy formation can be confirmed . |
9,282 | Suppose that you have an abstract for a scientific paper: we study the complex geometric phase acquired by the resonant states of an open quantum system which evolves irreversibly in a slowly time dependent environment . in analogy with the case of bound states ,
the berry phase factors of resonant states are holonomy group elements of a complex line bundle with structure group @xmath0 . in sharp contrast with bound states , accidental degeneracies of resonances produce a continuous closed line of singularities formally equivalent to a continuous distribution of `` magnetic '' charge on a `` diabolical '' circle , in consequence , we find different classes of topologically inequivalent non - trivial closed paths in parameter space . .
And you have already written the first three sentences of the full article: for many years now , it has been appreciated that there are distinct advantages in describing quantum resonances and the quantum phenomena associated to the production , evolution and decay of resonances in terms of resonant or gamow states , since many physical effects are then readily expressed and evaluated@xcite . in this work
, we will give closed analytical expressions for the complex berry phase of an open quantum system in a resonant state of a hermitian hamiltonian with non - self - adjoint boundary conditions , and we will discuss some of its properties . during the last fourteen years
the geometric phase factors arising in the adiabatic evolution of quantum systems@xcite have been the subject of many investigations@xcite ..
Please generate the next two sentences of the article | the early literature was mostly concerned with the geometric phase factors of closed systems driven by hermitian hamiltonians@xcite .
more recently there has been a substantial interest in the complex geometric phase acquired by the eigenstates of open quantum systems . |
9,283 | Suppose that you have an abstract for a scientific paper: c - loops are loops satisfying @xmath0 .
they often behave analogously to moufang loops and they are closely related to steiner triple systems and combinatorics .
we initiate the study of c - loops by proving : ( i ) steiner loops are c - loops , ( ii ) c - loops are alternative , inverse property loops with squares in the nucleus , ( iii ) the nucleus of a c - loop is a normal subgroup , ( iv ) c - loops modulo their nucleus are steiner loops , ( v ) c - loops are power associative , power alternative but not necessarily diassociative , ( vi ) torsion commutative c - loops are products of torsion abelian groups and torsion commutative @xmath1-c - loops ; and several other results .
we also give examples of the smallest nonassociative c - loops , and explore the analogy between commutative c - loops and commutative moufang loops . .
And you have already written the first three sentences of the full article: _ c - loops _ are loops satisfying the identity @xmath2 as we shall see , they are in a sense dual to moufang loops the most intensively studied variety of loops and they are closely related to steiner triple systems .
they are thus important both algebraically and combinatorially , and they are amenable to analysis by techniques from both fields . but in spite of this , little is known about them .
it is the intention of this paper to remedy this situation by laying a foundation for the systematic study of c - loops ..
Please generate the next two sentences of the article | we assume that the reader is familiar with the reasoning and notational conventions of loop theory , however , we do not hesitate to include loop - theoretical folklore and to point out some of the pitfalls of nonassociativity mostly because we fell into many of them ourselves .
c - loops were named by ferenc fenyves @xcite , who investigated the inclusions between varieties of loops of _ bol - moufang type_. these are varieties of loops defined by a single identity that : ( i ) involves three distinct variables on both sides , ( ii ) contains variables in the same order on both sides , ( iii ) exactly one of the variables appears twice on both sides . |
9,284 | Suppose that you have an abstract for a scientific paper: we show that a tetragonal lattice of weakly interacting cavities with uniaxial electromagnetic response is the photonic counterpart of topological crystalline insulators , a new topological phase of atomic band insulators .
namely , the frequency band structure stemming from the interaction of resonant modes of the individual cavities exhibits an omnidirectional band gap within which gapless surface states emerge for finite slabs of the lattice . due to the equivalence of a topological crystalline insulator with its photonic - crystal analog ,
the frequency band structure of the latter can be characterized by a @xmath0 topological invariant .
such a topological photonic crystal can be realized in the microwave regime as a three - dimensional lattice of dielectric particles embedded within a continuous network of thin metallic wires . .
And you have already written the first three sentences of the full article: the frequency band structure of artificial periodic dielectrics formally known as photonic crystals is the electromagnetic ( em ) counterpart of the electronic band structure in ordinary atomic solids .
recently , a new analogy between electron and photon states in periodic structures has been proposed by raghu and haldane , @xcite namely the one - way chiral edge states in two - dimensional ( 2d ) photonic - crystal slabs which are similar to the corresponding edge states in the quantum hall effect .
@xcite the photonic chiral edge states are a result of time - reversal ( tr ) symmetry breaking which comes about with the inclusion of gyroelectric/ gyromagnetic material components ; these states are robust to disorder and structural imperfections as long as the corresponding topological invariant ( chern number in this case ) remains constant . in certain atomic solids , tr.
Please generate the next two sentences of the article | symmetry breaking is not prerequisite for the appearance of topological electron states as it is the case in the quantum hall effect .
namely , when spin - orbit interactions are included in a tr symmetric graphene sheet , a bulk excitation gap and spin - filtered edge states emerge @xcite without the presence of an external magnetic field , a phenomenon which is known in literature as quantum spin hall effect . |
9,285 | Suppose that you have an abstract for a scientific paper: we consider a bipartite version of the color degree matrix problem . a bipartite graph @xmath0 is half - regular if all vertices in @xmath1 have the same degree .
we give necessary and sufficient conditions for a bipartite degree matrix ( also known as demand matrix ) to be the color degree matrix of an edge - disjoint union of half - regular graphs .
we also give necessary and sufficient perturbations to transform realizations of a half - regular degree matrix into each other .
based on these perturbations , a markov chain monte carlo method is designed in which the inverse of the acceptance ratios are polynomial bounded .
realizations of a half - regular degree matrix are generalizations of latin squares , and they also appear in applied neuroscience . + degree sequences ; degree matrix ; graph factorization ; edge packing ; latin squares ; markov chain monte carlo .
And you have already written the first three sentences of the full article: consider an edge weighted directed graph as a model of a neural network .
such network can be build up using real life measurements ( see for example , @xcite ) , and neuroscientists are interested in comparing this network with random networks . if the edges were not weighted , the typical approach would be to generate random graphs with prescribed in and out degrees .
this topic has a tremendous literature , see for example , @xcite , just to mention a few . in case of weights.
Please generate the next two sentences of the article | are introduced , one might want to generate a random graph that keeps not only the sum of the weights but also individual weights .
the weights can be transformed into colors , and then we are looking for an edge colored graph with prescribed in and out degrees for each color . |
9,286 | Suppose that you have an abstract for a scientific paper: we define and study a lattice model which we argue is in the universality class of the @xmath0 supercoset sigma model for a large range of values of the coupling constant @xmath1 . in this first paper
, we analyze in details the symmetries of this lattice model , in particular the decomposition of the space of the quantum spin chain @xmath2 as a bimodule over @xmath0 and its commutant , the brauer algebra @xmath3 .
it turns out that @xmath2 is a nonsemisimple module for both @xmath0 and @xmath3 .
the results are used in the companion paper to elucidate the structure of the ( boundary ) conformal field theory . #
1#2#3#4 # 1#2#3#4 constantin candu@xmath4 and hubert saleur@xmath5 _ service de physique thorique , cea saclay , + gif sur yvette , 91191 , france@xmath4 + _ _ department of physics and astronomy , university of southern california + los angeles , ca 90089 , usa@xmath6 + _ .
And you have already written the first three sentences of the full article: the solution of the @xmath7 worldsheet string theory is one of the cornerstones of the ads / cft duality program . despite continuous effort and progress on classical aspects in particular @xcite , and
the generally accepted presence of both integrability and conformal invariance symmetries , most aspects of the quantum theory remain elusive .
it is natural to try to understand some aspects of this quantum theory by first tackling simpler models with similar properties ..
Please generate the next two sentences of the article | the so called @xmath0 coset model - specifically , a sigma model on the supersphere @xmath8 - is a very attractive candidate for such an exercise : like the @xmath7 worldsheet theory it is conformal invariant and its target space is a supergroup coset .
of course , it lacks other aspects such as the brst structure of the string theory . |
9,287 | Suppose that you have an abstract for a scientific paper: the metric @xmath0 theories of gravity are generalized to five - dimensional spacetimes . by assuming a hypersurface - orthogonal killing vector field representing the compact fifth dimension , the five - dimensional theories are reduced to their four - dimensional formalism .
then we study the cosmology of a special class of @xmath1 models in a spatially flat frw spacetime .
it is shown that the parameter @xmath2 can be constrained to a certain range by the current observed deceleration parameter , and its lower bound corresponds to the kaluza - klein theory .
it turns out that both expansion and contraction of the extra dimension may prescribe the smooth transition from the deceleration era to the acceleration era in the recent past as well as an accelerated scenario for the present universe .
hence five - dimensional @xmath0 gravity can naturally account for the present accelerated expansion of the universe .
moreover , the models predict a transition from acceleration to deceleration in the future , followed by a cosmic recollapse within finite time .
this differs from the prediction of the five - dimensional brans - dicke theory but is in consistent with a recent prediction based on loop quantum cosmology .
pacs numbers : 04.50.-h , 98.80.es .
And you have already written the first three sentences of the full article: since 1998 , a series of independent observations , including type ia supernova @xcite , weak lens @xcite , cosmic microwave background anisotropy @xcite , large scale structure @xcite , baryon oscillation @xcite , etc . , have confirmed that our universe is undergoing a period of accelerated expansion .
this result conflicts fiercely with the prediction of general relativity , and therefore triggers a `` golden age '' of cosmology since researchers in cosmology , astrophysics , general relativity , particle physics are all involved in seeking for viable models to explain this phenomena . within the frame of general relativity , the cosmic speed - up can be viewed as an indication that the present universe is dominated by certain mysterious fluid with large negative pressure , called `` dark energy ''
. however , such simple explanations could hardly be satisfactory ..
Please generate the next two sentences of the article | the simplest @xmath3cdm model , which fits the observation data best so far , assumes a cosmological constant to be responsible for the dark content .
but the observed value of the constant @xmath3 is unnaturally smaller than any estimation by tens of orders @xcite . |
9,288 | Suppose that you have an abstract for a scientific paper: uhecr may be either nucleons @xcite or nuclei ; in the latter case the lightest nuclei , as @xmath0 or @xmath1 , li , be , explains at best the absence of virgo signals and the crowding of events around cen - a bent by galactic magnetic fields @xcite .
this model fit the observed nuclear mass composition discovered in auger .
however uhecr nucleons above gzk produce eev neutrinos while heavy nuclei , as fe uhecr do not produce much .
uhecr he nuclei at few @xmath2 suffer nuclear fragmentation ( producing low energetic neutrino at tens pevs ) but it suffer anyway photo - pion gzk suppression ( leading to eev neutrinos ) once above one - few @xmath3 .
both these cosmogenic uhe secondary neutrinos signals may influence usual predicted gzk @xcite,@xcite tau neutrino astronomy @xcite in significant and detectable way ; the role of resonant antineutrino electron - electron leading to tau air - shower may also rise . .
And you have already written the first three sentences of the full article: astrophysical uhe neutrinos is being searched , since four decades , at tev - pev energy via neutrino muons in underground detectors .
their signal is greatly polluted from above ( and below ) by cr secondary muons ( and atmospheric muon neutrinos into muons ) and partially suppressed at pevs , by earth size opacity .
horizontal muons at hundreds tev , originated by astrophysical uhe neutrinos are also polluted by leading prompt atmospheric signals . however , since four decades , the rise of highest energy neutrino astronomy is generally expected also by the cosmogenic eev neutrinos , secondaries of gzk @xcite,@xcite cut - off on ultra high cosmic rays ( uhecr ) ..
Please generate the next two sentences of the article | these ones are difficult to observe in @xmath5 detector .
but since a decade @xcite the uhe tau neutrino astronomy have been foreseen and suggested in present and future detectors . |
9,289 | Suppose that you have an abstract for a scientific paper: we propose a strategy for perfect state transfer in spin chains based on the use of an unmodulated coupling hamiltonian whose coefficients are explicitly time dependent .
we show that , if specific and non - demanding conditions are satisfied by the temporal behavior of the coupling strengths , our model allows perfect state transfer .
the paradigma put forward by our proposal holds the promises to set an alternative standard to the use of clever encoding and coupling - strength engineering for perfect state transfer .
multiple - spin systems , in particular spin chains , have recently been the object of extensive studies . from the quantum information processing ( qip )
viewpoint , such systems embody valuable media for quantum protocols .
in fact , it has been found that specific forms of built - in and permanent intra - register couplings , such as those typical of spin - chain models , could be used for the purposes of quantum computation @xcite and communication in quantum networks .
this second possibility is particularly interesting .
in fact , while photons are ideal candidates for the long - haul transmission of information among different local nodes @xcite , their use in hybrid architectures for quantum networks ( where the nodes are embodied by matter - like systems ) requires the use of quantum interfaces . despite the impressive experimental successes reported in this area , the realization of an interface is usually accompanied by technical problems and errors in transmission . on the other hand , for short - distance quantum communication ,
an alternative arrangement where information carriers and processors are embodied by physical systems having the same nature could be more advantageous . in the seminal work in ref .
@xcite , the idea of using spin chains as _
quantum wires _ has been proposed as a way to avoid the interfacing problems mentioned above .
the original idea has then been extended along various directions ( for more details , see ref .
@xcite ) .....
And you have already written the first three sentences of the full article: the system we analyze is an open spin - chain of @xmath0 elements , whose hamiltonian reads @xmath1+\sum^n_{i=1}b(t)\hat{z}_i.\ ] ] here , @xmath2 and @xmath3 are the coupling strengths of the pairwise interaction between adjacent spins and @xmath4 is a magnetic field . in our notation ,
@xmath5 and @xmath6 denote respectively the @xmath7 and @xmath8-pauli matrix . for the sake of simplicity , we consider @xmath0 as an odd number .
however , all the results presented here can be straightforwardly adapted to the case of an even number of spins in the chain ..
Please generate the next two sentences of the article | physical units are chosen throughout the article so that @xmath9 .
it is important to note that the inter - spin couplings and the amplitude of the magnetic field are site independent . |
9,290 | Suppose that you have an abstract for a scientific paper: optical nanofibres are increasingly being used in cold atom experiments due to their versatility and the clear advantages they have when developing all - fibred systems for quantum technologies .
they provide researchers with a method of overcoming the rayleigh range for achieving high intensities in a focussed beam over a relatively long distance , and can act as a noninvasive tool for probing cold atoms . in this review article , we will briefly introduce the theory of mode propagation in an ultrathin optical fibre and highlight some of the more significant theoretical and experimental progresses to date , including the early work on atom probing , manipulation and trapping , the study of atom - dielectric surface interactions , and the more recent observation of nanofibre - mediated nonlinear optics phenomena in atomic media . the functionality of optical nanofibres in relation to the realisation of atom - photon hybrid quantum systems is also becoming more evident as some of the earlier technical challenges are surpassed and , recently , several schemes to implement optical memories have been proposed .
we also discuss some possible directions where this research field may head , in particular in relation to the use of optical nanofibres that can support higher - order modes with an associated orbital angular momentum . .
And you have already written the first three sentences of the full article: the development of quantum - based devices is becoming increasingly necessary for future technological advances and , as a result , enormous effort is being made to find suitable experimental platforms , one of which is cold , neutral atoms .
strong coupling can be viewed as an essential requirement to devise quantum networks based on neutral atoms @xcite and , until recently , free - space cavities were the most promising method for enabling an atomic system to enter this regime @xcite .
very recently , kato and aoki @xcite demonstrated strong coupling for a single trapped atom and an all - fibred optical cavity based on an optical nanofibre ( onf ) spliced between two fibre bragg grating mirrors , thereby illustrating the potential offered by onfs for future quantum technological advances ..
Please generate the next two sentences of the article | + another distinct advantage of optical nanofibres is that they facilitate the study of nonlinear phenomena in an atomic medium without requiring a tightly focussed laser beam , as in free - space optics .
if light is to be tightly focussed , the interaction distance is essentially limited by the rayleigh length , @xmath0 , given by @xmath1 , where @xmath2 is the beam radius at the narrowest point and @xmath3 is the laser wavelength . if we consider a 780 nm beam , corresponding to the d@xmath4 line in @xmath5rb , the interaction length is limited to about 4 @xmath6 m if the beam is focussed to a 1 @xmath6 m radius . |
9,291 | Suppose that you have an abstract for a scientific paper: we report on the present stage of sn 1987a as observed by the _
chandra _ x - ray observatory .
we reanalyze published _
chandra _ observations and add three more epochs of _ chandra _ data to get a consistent picture of the evolution of the x - ray fluxes in several energy bands .
we discuss the implications of several calibration issues for _ chandra _ data . using the most recent _ chandra _ calibration files , we find that the 0.5 - 2.0 kev band fluxes of sn 1987a have increased by @xmath0 6 @xmath1 erg s@xmath2 @xmath3 per year since 2009 .
this is in contrast with our previous result that the 0.5 - 2.0 kev light curve showed a sudden flattening in 2009 .
based on our new analysis , we conclude that the forward shock is still in full interaction with the equatorial ring . .
And you have already written the first three sentences of the full article: stellar winds of massive stars leave their imprints on the surrounding medium before they explode . after the explosion , the outer shocks of the supernova probe the circumstellar medium , thereby mapping the late stages of the stars evolution . because of its youth
, the remnant of sn 1987a provides a unique opportunity to investigate these late stages .
the case of sn 1987a is especially interesting , as it exhibits the enigmatic three ring structure visible in optical images @xcite ..
Please generate the next two sentences of the article | this structure probably originates from the interaction of a wind from the slow red supergiant phase with the faster wind from the blue supergiant phase @xcite .
the morphology of this structure might provide clues to a binary - merger scenario for the progenitor @xcite . however , this three ring structure might also result from mass - loss from a fast - rotating star @xcite . |
9,292 | Suppose that you have an abstract for a scientific paper: low - temperature ( @xmath0 60k ) phase changes of free clusters containing 50 , 137 , and 229 @xmath1 molecules have been observed in isoenergetic molecular dynamics computations .
bulk solid methane exhibits structural phase transformation at 20.4 k. however , clusters of 50 molecules already melt at @xmath2 25 k , which makes the observation of solid - solid transformations rather challenging . .
And you have already written the first three sentences of the full article: small free clusters of molecules with very high symmetry ( octahedral ) have been found to resemble bulk of the same substance even in the case of small number of ingredients ( 30 to 80 ) @xcite .
the number of particles ( molecules or / and atoms ) that mimics bulk properties like phase transitions is strongly dependent on the range of the potential .
the effect of decreasing the range of the potential is to destabilize strained structures @xcite . in the case of long - range potentials ( coulomb @xcite ).
Please generate the next two sentences of the article | one detects structures , determined by the co - operative ( collective ) interaction - the system is expected to transform easier than in the case of short - range interactions . on the other side ,
the surface of free clusters plays much more important role for long - range potentials . |
9,293 | Suppose that you have an abstract for a scientific paper: the measurement of the @xmath0 cross section allows to determine the pion form factor @xmath1 and the two pion contribution to the muon anomaly @xmath2 .
such a measurement has been performed with the kloe detector at @xmath3 , the frascati @xmath4-factory .
+ the preliminary results on the combination of the last analysis ( kloe12 ) with two previous published ( kloe08 , kloe10 ) will be presented in the following . .
And you have already written the first three sentences of the full article: the anomalous magnetic moment of the muon defined as @xmath5 , can be accurately measured and , within the sm framework , precisely predicted@xcite .
the experimental value of @xmath2 ( @xmath6 ) measured at the brookhaven laboratory differs from the sm estimates by 3.2 - 3.6 @xmath7 @xcite .
if the deviation is confirmed with higher precision it would signal of new physics ..
Please generate the next two sentences of the article | the main theoretical uncertainty for @xmath2 comes from hadronic contributions .
the leading order hadronic term can be derived from a combination of experimental cross section data , related to @xmath8 annihilation to hadrons . at @xmath3 |
9,294 | Suppose that you have an abstract for a scientific paper: we review recent results obtained in the physics of the thermal casimir force acting between two dielectrics , dielectric and metal , and between metal and semiconductor .
the detailed derivation for the low - temperature behavior of the casimir free energy , pressure and entropy in the configuration of two real dielectric plates is presented . for dielectrics with finite static dielectric permittivity
it is shown that the nernst heat theorem is satisfied .
hence , the lifshitz theory of the van der waals and casimir forces is demonstrated to be consistent with thermodynamics .
the nonzero dc conductivity of dielectric plates is proved to lead to a violation of the nernst heat theorem and , thus , is not related to the phenomenon of dispersion forces .
the low - temperature asymptotics of the casimir free energy , pressure and entropy are derived also in the configuration of one metal and one dielectric plate .
the results are shown to be consistent with thermodynamics if the dielectric plate possesses a finite static dielectric permittivity .
if the dc conductivity of a dielectric plate is taken into account this results in the violation of the nernst heat theorem .
we discuss both the experimental and theoretical results related to the casimir interaction between metal and semiconductor with different charge carrier density .
discussions in the literature on the possible influence of spatial dispersion on the thermal casimir force are analyzed . in conclusion ,
the conventional lifshitz theory taking into account only the frequency dispersion remains the reliable foundation for the interpretation of all present experiments . .
And you have already written the first three sentences of the full article: the casimir effect@xcite is the force and also the specific polarization of the vacuum arising in restricted quantization volumes and originating from the zero - point oscillations of quantized fields .
this force acts between two closely spaced macrobodies , between an atom or a molecule and macrobody or between two atoms or molecules . during more than fifty years ,
passed after the discovery of the casimir effect , it has attracted much theoretical attention because of numerous applications in quantum field theory , atomic physics , condensed matter physics , gravitation and cosmology , mathematical physics , and in nanotechnology ( see monographs and reviews ) . in multidimensional kaluza - klein supergravity.
Please generate the next two sentences of the article | the casimir effect was used@xcite as a mechanism for spontaneous compactification of extra spatial dimensions and for constraining the yukawa - type corrections to newtonian gravity.@xcite in quantum chromodynamics the casimir energy plays an important role in the bag model of hadrons.@xcite in cavity quantum electrodynamics the casimir interaction between an isolated atom and a cavity wall leads to the level shifts of atomic electrons depending on the position of the atom near the wall.@xcite both the van der waals and casimir forces are used@xcite for the theoretical interpretation of recent experiments on quantum reflection and bose - einstein condensation of ultracold atoms on or near the cavity wall of different nature .
in condensed matter physics the casimir effect turned out to be important for interaction of thin films , in wetting processes , and in the theory of colloids and lattice defects.@xcite the casimir force was used to actuate nanoelectromechanical devices@xcite and to study the absorption of hydrogen atoms by carbon nanotubes.@xcite theoretical work on the calculation of the casimir energies and forces stimulated important achievements in mathematical physics and in the theory of renormalizations connected with the method of generalized zeta function and heat kernel expansion.@xcite all this made the casimir effect the subject of general interdisciplinary interest and attracted permanently much attention in the scientific literature . |
9,295 | Suppose that you have an abstract for a scientific paper: it is general knowledge that the harmonic mean @xmath0 and that the geometric mean @xmath1 , where @xmath2 and @xmath3 are two positive numbers . in the paper ,
the authors show by several approaches that the harmonic mean @xmath4 and the geometric mean @xmath5 are all bernstein functions of @xmath6 and establish integral representations of the means @xmath7 and @xmath8 . .
And you have already written the first three sentences of the full article: we recall some notions and definitions .
a function @xmath9 is said to be completely monotonic on an interval @xmath10 if @xmath9 has derivatives of all orders on @xmath11 and @xmath12 for all @xmath13 and @xmath14 .
if @xmath15 for some nonnegative integer @xmath16 is completely monotonic on an interval @xmath10 , but @xmath17 is not completely monotonic on @xmath11 , then @xmath18 is called a completely monotonic function of @xmath16-th order on an interval @xmath11 ..
Please generate the next two sentences of the article | a function @xmath9 is said to be logarithmically completely monotonic on an interval @xmath10 if its logarithm @xmath19 satisfies @xmath20^{(k)}\ge0\ ] ] for all @xmath13 and @xmath21 .
a function @xmath22 is called a bernstein function on @xmath11 if @xmath18 has derivatives of all orders and @xmath23 is completely monotonic on @xmath11 . |
9,296 | Suppose that you have an abstract for a scientific paper: dust polarization orientations in molecular clouds often tend to be close to tangential to the stokes @xmath0 dust continuum emission contours .
the magnetic field and the emission gradient orientations , therefore , show some correlation .
a method is proposed , which in the framework of ideal magneto - hydrodynamics ( mhd ) connects the measured angle between magnetic field and emission gradient orientations to the total field strength .
the approach is based on the assumption that a change in emission intensity ( gradient ) is a measure for the resulting direction of motion in the mhd force equation . in particular
, this new method leads to maps of position - dependent magnetic field strength estimates .
when evaluating the field curvature and the gravity direction locally on a map , the method can be generalized to arbitrary cloud shapes .
the technique is applied to high - resolution ( @xmath1 ) submillimeter array polarization data of the collapsing core w51 e2 . a tentative @xmath2 mg field strength is found when averaging over the entire core .
the analysis further reveals some structures and an azimuthally averaged radial profile @xmath3 for the field strength .
maximum values close to the center are around @xmath4 mg . the currently available observations lack higher resolution data to probe the innermost part of the core where the largest field strength is expected from the method .
application regime and limitations of the method are discussed . as a further important outcome of this technique
, the local significance of the magnetic field force compared to the other forces can be quantified in a model - independent way , from measured angles only .
finally , the method can potentially also be expanded and applied to other objects ( besides molecular clouds ) with measurements that reveal the field morphology , as e.g. faraday rotation measurements in galaxies . .
And you have already written the first three sentences of the full article: magnetic fields are being recognized as one of the key components in star formation theories ( e.g. , * ? ? ?
nevertheless , their exact role in the formation and evolution of molecular clouds is still a matter of debate in the literature . on the observational side ,
one of the difficulties is to accurately measure the magnetic field strength ..
Please generate the next two sentences of the article | the zeeman effect still provides the only known method of directly measuring magnetic field strengths along the line of sight in a molecular cloud ( e.g. , * ? ? ?
* ; * ? ? ? |
9,297 | Suppose that you have an abstract for a scientific paper: we propose an automated method for detecting aggressive prostate cancer(cap ) ( gleason score @xmath07 @xcite ) based on a comprehensive analysis of the lesion and the surrounding normal prostate tissue which has been simultaneously captured in t2-weighted mr images , diffusion - weighted images ( dwi ) and apparent diffusion coefficient maps ( adc ) .
the proposed methodology was tested on a dataset of 79 patients ( 40 aggressive , 39 non - aggressive ) .
we evaluated the performance of a wide range of popular quantitative imaging features on the characterization of aggressive versus non - aggressive cap .
we found that a group of 44 discriminative predictors among 1464 quantitative imaging features can be used to produce an area under the roc curve of 0.73 . .
And you have already written the first three sentences of the full article: prostate cancer ( cap ) is the second leading cause of cancer death among american men , killing 29,000 men each year .
the us preventive services task force ( uspstf ) cited the substantial rate of prostate cancer overdiagnosis ( 1750 % ) and overtreatment as justification for discouraging the use of prostate specific antigen ( psa ) for early detection of prostate cancer @xcite.the problem of overdiagnosis is caused by the inability to distinguish aggressive cancer from non - aggressive cancer .
preferential detection of aggressive cancers would improve outcomes in men who need treatment while sparing men with non - aggressive cancers the harms of treatment ..
Please generate the next two sentences of the article | this is critically important because non - aggressive cancers are slow growing and rarely harmful , while aggressive cancers pose a substantial risk of morbidity and mortally @xcite . yet , current methods of prostate cancer detection , including the use of conventional ` blind ' biopsy , detect more non - aggressive cancers than aggressive cancers .
multiparametric mr is a powerful imaging technique that is useful for detection of aggressive cap . |
9,298 | Suppose that you have an abstract for a scientific paper: information - theoretic derivations of the formalism of quantum theory have recently attracted much attention .
we analyze the axioms underlying a few such derivations and propose a conceptual framework in which , by combining several approaches , one can retrieve more of the conventional quantum formalism . .
And you have already written the first three sentences of the full article: initially formulated by john wheeler@xcite , the program of deriving quantum formalism from information - theoretic principles has been receiving lately much attention .
thus , jozsa@xcite promotes a viewpoint which `` attempts to place a notion of information at a primary fundamental level in the formulation of quantum physics '' .
fuchs @xcite presents his program as follows : `` the task is not to make sense of the quantum axioms by heaping more structure , more definitions ... on top of them , but to throw them away wholesale and start afresh.
Please generate the next two sentences of the article | . we should be relentless in asking ourselves : from what deep _ physical _ principles might we _ derive _ this exquisite mathematical structure ? ..
i myself see no alternative but to contemplate deep and hard the tasks , the techniques , and the implications of quantum information theory . '' in a similar fashion , rovelli@xcite distinguishes a philosophical problem of interpretation from a mathematical problem of derivation of quantum mechanical formalism from the first principles . |
9,299 | Suppose that you have an abstract for a scientific paper: this paper develops a symplectic bifurcation theory for integrable systems in dimension four . we prove that if an integrable system has no hyperbolic singularities and its bifurcation diagram has no vertical tangencies , then the fibers of the induced singular lagrangian fibration are connected . the image of this singular lagrangian fibration is , up to smooth deformations , a planar region bounded by the graphs of two continuous functions .
the bifurcation diagram consists of the boundary points in this image plus a countable collection of rank zero singularities , which are contained in the interior of the image .
because it recently has become clear to the mathematics and mathematical physics communities that the bifurcation diagram of an integrable system provides the best framework to study symplectic invariants , this paper provides a setting for studying quantization questions , and spectral theory of quantum integrable systems . .
And you have already written the first three sentences of the full article: a major obstacle to a symplectic theory of finite dimensional integrable hamiltonian systems is that _ differential topological _ and _ symplectic _ problems appear side by side , but smooth and symplectic methods do not always mesh well .
morse - bott theory represents a success in bringing together in a cohesive way continuous and differential tools , and it has been used effectively to study properties of dynamical systems . but incorporating symplectic information into the context of dynamical systems is far from automatic . however , many concrete examples are known for which computations , and numerical simulations , exhibit a close relationship between the symplectic dynamics of a system , and the differential topology of its bifurcation set . in the 1980s and 1990s , the fomenko school developed a morse theory for regular energy surfaces of integrable systems . moreover ,
theoretical successes ( in any dimension ) for compact periodic systems in the 1970s and 1980s by atiyah , guillemin , kostant , sternberg and others , gave hope that one can find a mathematical theory for bifurcations of integrable systems in the symplectic setting ..
Please generate the next two sentences of the article | this paper develops a symplectic bifurcation theory for integrable systems in dimension four compact or not .
because it recently has become clear that the bifurcation diagram of an integrable system is the natural setting to study symplectic invariants ( see for instance @xcite ) , this paper provides a setting for the study of quantum integrable systems . |
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