id
int64 0
203k
| input
stringlengths 66
4.29k
| output
stringlengths 0
3.83k
|
|---|---|---|
3,200 | Suppose that you have an abstract for a scientific paper: we examine the computation of the nucleation barrier used in the expression for false vacuum decay rates in finite temperature field theory . by a detailed analysis of the determinantal prefactor
, we show that the correct bounce solution used in the computation of the nucleation barrier should not include loop corrections coming from the scalar field undergoing decay .
temperature corrections to the bounce appear from loop contributions from other fields coupled to the scalar field .
we compute the nucleation barrier for a model of scalar fields coupled to fermions , and compare our results to the expression commonly used in the literature .
we find that , for large enough self - couplings , the inclusion of scalar loops in the expression of the nucleation barrier leads to an underestimate of the decay rate in the neighborhood of the critical temperature .
pacs number(s ) : 98.80.cq , 64.60.qb .
+ e - mail : [email protected] ; [email protected] ; [email protected] . .
And you have already written the first three sentences of the full article: for the past decade or so , the study of first - order phase transitions in cosmology has been the focus of much interest due to their possible relevance to the physics of the early universe .
some well - known examples are inflationary models @xcite , the quark - hadron transition @xcite and , more recently , the generation of the cosmological baryon asymmetry in the electroweak phase transition @xcite . in a first - order phase transition
, the initial metastable phase decays to the stable phase by the nucleation of bubbles larger than a critical size ..
Please generate the next two sentences of the article | this decay may be triggered by either quantum or thermal fluctuations , depending on how the ambient temperature compares to the nucleation barrier @xcite . within a cosmological context
, the cooling is provided by the expansion of the universe ; the long - wavelength modes of the order parameter responsible for the symmetry breaking transition are coupled to the `` environment '' , which is assumed to be in local thermal equilibrium at some temperature @xmath0 . |
3,201 | Suppose that you have an abstract for a scientific paper: in the framework of the theory of open systems based on completely positive quantum dynamical semigroups , we give a description of the continuous - variable entanglement for a system consisting of two independent harmonic oscillators interacting with a general environment . using peres - simon necessary and sufficient criterion for separability of two - mode gaussian states , we describe the generation and evolution of entanglement in terms of the covariance matrix for an arbitrary gaussian input state .
for some values of diffusion and dissipation coefficients describing the environment , the state keeps for all times its initial type : separable or entangled . in other cases , entanglement generation or entanglement collapse ( entanglement sudden death ) take place or even a periodic collapse and revival of entanglement .
we show that for certain classes of environments the initial state evolves asymptotically to an entangled equilibrium bipartite state , while for other values of the coefficients describing the environment , the asymptotic state is separable .
we calculate also the logarithmic negativity characterizing the degree of entanglement of the asymptotic state . .
And you have already written the first three sentences of the full article: when two systems are immersed in an environment , then , besides and at the same time with the quantum decoherence phenomenon , the environment can also generate a quantum entanglement of the two systems @xcite . in certain circumstances , the environment enhances the entanglement and in others it suppresses the entanglement and the state describing the two systems becomes separable .
the structure of the environment may be such that not only the two systems become entangled , but also such that the entanglement is maintained for a definite time or a certain amount of entanglement survives in the asymptotic long - time regime . in the present paper we investigate , in the framework of the theory of open systems based on completely positive quantum dynamical semigroups , the dynamics of the continuous - variable entanglement for a subsystem composed of two identical harmonic oscillators interacting with an environment .
we are interested in discussing the correlation effect of the environment , therefore we assume that the two systems are independent , i.e. they do not interact directly ..
Please generate the next two sentences of the article | the initial state of the subsystem is taken of gaussian form and the evolution under the quantum dynamical semigroup assures the preservation in time of the gaussian form of the state .
the organizing of the paper is as follows . in sec . |
3,202 | Suppose that you have an abstract for a scientific paper: the connection between the thermodynamics of charged finite nuclear systems and the asymptotically measured partitions is presented .
some open questions , concerning in particular equilibrium partitions are discussed .
we show a detailed comparison of the decay patterns in @xmath0 central collisions and in @xmath1 quasi - projectile events .
observation of abnormally large fluctuations in carefully selected samples of data is reported as an indication of a first order phase transition ( negative heat capacity ) in the nuclear equation of state . _
8th international conference on nucleus - nucleus collisions , moscow 2003 _ .
And you have already written the first three sentences of the full article: in the last 20 years and especially in the most recent ones , considerable progress has been achieved both theoretically and experimentally in the investigation of nuclear reaction dynamics and thermodynamics in the fermi energy regime @xcite . from a theoretical point of view
, strong efforts have been devoted to the understanding of the nuclear equation of state ( eos ) either with transport theories or statistical approaches . from an experimental point of view
new generation @xmath2 detectors have been developed and are now operating at different accelerator facilities ( dubna , ganil , gsi , lnl , lns , msu , texas a - m ) ..
Please generate the next two sentences of the article | they are producing a huge amount of exclusive data and new kind of analyses .
very rich information has already been extracted from experimental studies on intermediate energy heavy ion collisions . |
3,203 | Suppose that you have an abstract for a scientific paper: we study the conductance of mesoscopic graphene rings in the presence of a perpendicular magnetic field by means of numerical calculations based on a tight - binding model .
first , we consider the magnetoconductance of such rings and observe the aharonov - bohm effect .
we investigate different regimes of the magnetic flux up to the quantum hall regime , where the aharonov - bohm oscillations are suppressed .
results for both clean ( ballistic ) and disordered ( diffusive ) rings are presented .
second , we study rings with smooth mass boundary that are weakly coupled to leads .
we show that the valley degeneracy of the eigenstates in closed graphene rings can be lifted by a small magnetic flux , and that this lifting can be observed in the transport properties of the system . .
And you have already written the first three sentences of the full article: since their experimental discovery , graphite monolayers , also known as graphene , have attracted a huge amount of interest among both experimentalists and theorists due to the linear low energy dispersion and various properties stemming from this unusual dispersion @xcite .
for instance , graphene has opened new perspectives for mesoscopic physics , such as pseudodiffusive conductance at the dirac point @xcite , specular andreev reflection @xcite , or the signatures of symmetries of the graphene hamiltonian in the conductance of diffusive wires @xcite and ballistic cavities @xcite .
mesoscopic rings can be considered as prototypical devices in mesoscopic physics , as they show one of the most basic coherence effects , namely the aharonov - bohm ( ab ) effect @xcite : oscillations of the transmission , or dimensionless conductance , @xmath0 as a function of the magnetic flux @xmath1 through the ring ..
Please generate the next two sentences of the article | the reason for these oscillations is the phase difference @xmath2 between electrons travelling along the different arms of the ring . here
, @xmath3 is the magnetic flux quantum . |
3,204 | Suppose that you have an abstract for a scientific paper: in this paper we present a study of an exciton system where electrons and holes are confined in double quantum well structures . the dominating interaction between excitons in such systems
is a dipole - dipole repulsion .
we show that the tail of this interaction leads to a strong correlation between excitons and substantially affects the behavior of the system . making use of qualitative arguments and estimates
we develop a picture of the exciton - exciton correlations in the whole region of temperature and concentration where excitons exist .
it appears that at low concentration degeneracy of the excitons is accompanied with strong multi - particle correlation so that the system can not be considered as a gas . at high concentration
the repulsion suppresses the quantum degeneracy down to temperatures that could be much lower than in a bose gas with contact interaction .
we calculate the blue shift of the exciton luminescence line which is a sensitive tool to observe the exciton - exciton correlations . .
And you have already written the first three sentences of the full article: a very active investigation of excitons in coupled quantum wells for more than two decades was first motivated by the possibility to reach bose condensation and superfluidity in this system .
further experiments discovered a very large number of related phenomena and quite rich physics of the system ( see refs.@xcite and references therein ) .
theory predicts the existence of many phases with different and unusual properties.@xcite the most expected and searched for is the settling in of coherence in such 2d exciton systems ..
Please generate the next two sentences of the article | a coherence of the exciton bose condensate has to reveal itself in some coherent properties of the exciton luminescence .
investigation of the luminescence led to discovery of not only its coherence @xcite but also a number of patterns not completely understood so far @xcite . a substantial role in these phenomena |
3,205 | Suppose that you have an abstract for a scientific paper: the status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed .
einstein s equivalence principle ( eep ) is well supported by experiments such as the etvs experiment , tests of special relativity , and the gravitational redshift experiment .
future tests of eep will search for new interactions arising from unification or quantum gravity .
tests of general relativity have reached high precision , including the light deflection , the shapiro time delay , the perihelion advance of mercury , and the nordtvedt effect in lunar motion .
gravitational wave damping has been detected to half a percent using the binary pulsar , and new binary pulsar systems promise further improvements .
when direct observation of gravitational radiation from astrophysical sources begins , new tests of general relativity will be possible . .
And you have already written the first three sentences of the full article: at the time of the birth of general relativity ( gr ) , experimental confirmation was almost a side issue .
einstein did calculate observable effects of general relativity , such as the deflection of light , which were tested , but compared to the inner consistency and elegance of the theory , he regarded such empirical questions as almost peripheral . but
today , experimental gravitation is a major component of the field , characterized by continuing efforts to test the theory s predictions , to search for gravitational imprints of high - energy particle interactions , and to detect gravitational waves from astronomical sources ..
Please generate the next two sentences of the article | the modern history of experimental relativity can be divided roughly into four periods , genesis , hibernation , a golden era , and the quest for strong gravity .
the genesis ( 18871919 ) comprises the period of the two great experiments which were the foundation of relativistic physics the michelson - morley experiment and the etvs experiment and the two immediate confirmations of gr the deflection of light and the perihelion advance of mercury . |
3,206 | Suppose that you have an abstract for a scientific paper: in high transition temperature ( @xmath0 ) superconductivity , charge doping is a natural tuning parameter that takes copper oxides from the antiferromagnet to the superconducting region . in the metallic state above @xmath0
the standard landau s fermi - liquid theory of metals as typified by the temperature squared ( @xmath1 ) dependence of resistivity appears to break down . whether the origin of the non - fermi - liquid behavior is related to physics specific to the cuprates is a fundamental question still under debate .
we uncover a new transformation from the non - fermi- to a standard fermi - liquid state driven not by doping but by magnetic field in the overdoped high-@xmath0 superconductor tl@xmath2ba@xmath2cuo@xmath3 . from the @xmath4-axis resistivity measured up to 45 t
, we show that the fermi - liquid features appear above a sufficiently high field which decreases linearly with temperature and lands at a quantum critical point near the superconductivity s upper critical field with the fermi - liquid coefficient of the @xmath1 dependence showing a power - law diverging behavior on the approach to the critical point .
this field - induced quantum criticality bears a striking resemblance to that in quasi - two dimensional heavy - fermion superconductors , suggesting a common underlying spin - related physics in these superconductors with strong electron correlations .
uantum criticality refers to a phase transition process between competing states of matter governed not by thermal but by quantum fluctuations demanded by heisenberg uncertainty principle @xcite .
it has emerged at the front and center of the physics of strongly correlated electron systems known to host competing quantum orders , and is witnessed by a proliferation of reports on heavy fermions @xcite , itinerant ( quantum ) magnets @xcite , and high - transition - temperature ( high-@xmath0 ) superconductors @xcite , with quantum matter tuned ( at times arguably ) through a transition by pressure , magnetic field , or....
And you have already written the first three sentences of the full article: figure [ rho_t ] shows the temperature dependence of @xmath4-axis resistivity at zero and 45 t fields . at zero field
, @xmath11 is metallic all the way down to @xmath0 .
this represents a clear contrast with the semiconductinglike upturn in @xmath14 observed at lower dopings of bi@xmath2sr@xmath2cacu@xmath2o@xmath15 @xcite in the pseudogap state @xcite ..
Please generate the next two sentences of the article | we can examine our data within the overall temperature dependence @xmath16 which reproduces the temperature dependence of @xmath13 @xcite .
also , it can be as easily fitted by a power law with the exponent 1.3 ( @xmath17 ) ( inset in fig . |
3,207 | Suppose that you have an abstract for a scientific paper: we observed the `` micro - quasar '' four times with _ chandra_. two hrc - i observations were made in 2000 september - october spanning an intermediate - to - hard spectral transition ( identified with _ rxte _ ) .
another hrc - i and an acis / hetgs observation were made in 2001 march following a hard - to - soft transition to a very low flux state .
the accurate position ( j2000 ) of the source is ra @xmath0 18 01 12.40 , dec @xmath0 @xmath125 44 36.0 ( 90% confidence radius @xmath0 0.6 ) , consistent with the purported variable radio counterpart .
all images are consistent with being a point source , indicating that any bright jet is less than 1light - month in projected length , assuming a distance of 8.5kpc .
the march spectrum is well - fit with a multi - color disk - blackbody with an inner temperature of @xmath2kev , interstellar absorption of @xmath3 , and ( un - absorbed ) 1@xmath110kev luminosity of @xmath4 .
no narrow emission lines are apparent in the spectrum and upper limits to line equivalent widths are given .
# 1_#1 _ # 1_#1 _ = # 1 1.25 in .125 in .25 in .
And you have already written the first three sentences of the full article: and its sister source , , were the first objects dubbed `` micro - quasars '' .
their spectra are typical of galactic black hole candidates ( bhcs ) , and they are associated with time variable cores of double - lobed radio sources , reminiscent of extra - galactic radio sources .
this morphology , seen on a parsec scale within the milky way , earned them their nickname . and are the brightest persistent sources in the galactic bulge above @xmath550 kev @xcite ..
Please generate the next two sentences of the article | their timing characteristics are typical of the black hole low / hard state @xcite , and they consistently emit near their brightest observed levels , although they vary over times of days to years .
their emission properties are readily likened to the canonical bhc , cyg x-1 . |
3,208 | Suppose that you have an abstract for a scientific paper: we study how a fraction of a population should be vaccinated to most efficiently stop epidemics .
we argue that only local information ( about the neighborhood of specific vertices ) is usable in practice , and hence we consider only local vaccination strategies .
the efficiency of the vaccination strategies is investigated with both static and dynamical measures . among other things
we find that the most efficient strategy for many real - world situations is to iteratively vaccinate the neighbor of the previous vaccinee that has most links out of the neighborhood . .
And you have already written the first three sentences of the full article: diseases spread over networks .
the spreading dynamics are closely related to the structure of networks . for this reason network epidemiology
has turned into of the most vibrant subdisciplines of complex network studies ..
Please generate the next two sentences of the article | @xcite a topic of great practical importance within network epidemiology is the vaccination problem : how should a population be vaccinated to most efficiently prevent a disease to turn into an epidemic ? for economic reasons it is often not possible to vaccinate the whole population .
some vaccines have severe side effects and for this reason one may also want to keep number of vaccinated individuals low . |
3,209 | Suppose that you have an abstract for a scientific paper: we study the chiral condensates and the @xmath0 meson correlators of the massive schwinger model in @xmath1 vacuum .
our data suggest that the pseudoscalar operator does condense in a fixed topological sector and gives long range correlations of the @xmath0 meson .
we find that this is well understood from the clustering decomposition and statistical picture .
our result also indicates that even in @xmath2 case , the long range correlation of @xmath0 meson receives non - zero contributions from all the topological sectors and that their cancellation is non - trivial and requires accurate measurement of the reweighting factors as well as the expectation values .
it is then clear that the fluctuation of the `` disconnected '' diagram originates from the pseudoscalar condensates . .
And you have already written the first three sentences of the full article: in qcd or the massive schwinger model in @xmath3 vacuum @xcite , it is well known that the scalar operator condense while the pseudoscalar does not ; @xmath4 where the second equation follows from parity symmetry . however ,
if we have a non - zero @xmath5 term , which violates parity symmetry , both of them have non - zero expectation values ; @xmath6 which indicates that @xmath7 meson should have a long - range correlation as @xmath8 we would like to present our numerical results of the 2-flavor massive schwinger model with a @xmath1 term .
we investigate @xmath9 condensates and the @xmath0 meson correlators in each topological sector ..
Please generate the next two sentences of the article | it is also found that they are non - trivially related each other to reproduce the @xmath5 dependence .
we find that their behavior is well understood by the intuitive picture based on the clustering decomposition and the statistical mechanics . |
3,210 | Suppose that you have an abstract for a scientific paper: the hot gaseous halos of galaxies likely contain a large amount of mass and are an integral part of galaxy formation and evolution .
the milky way has a @xmath0 k halo that is detected in emission and by absorption in the resonance line against bright background agns , and for which the best current model is an extended spherical distribution . using xmm - newton rgs data
, we measure the doppler shifts of the absorption - line centroids toward an ensemble of agns .
these doppler shifts constrain the dynamics of the hot halo , ruling out a stationary halo at about @xmath1 and a co - rotating halo at @xmath2 , and leading to a best - fit rotational velocity @xmath3kms@xmath4 for an extended halo model .
these results suggest that the hot gas rotates and that it contains an amount of angular momentum comparable to that in the stellar disk .
we examined the possibility of a model with a kinematically distinct disk and spherical halo . to be consistent with the emission - line x - ray data the disk must contribute less than 10% of the column density , implying that the doppler shifts probe motion in the extended hot halo . .
And you have already written the first three sentences of the full article: a basic prediction of @xmath5cdm galaxy - formation models is the existence of a hot ( @xmath6k ) halo of gas accreted from the intergalactic medium around milky way - sized galaxies ( extending to the virial radius ) , which forms as infalling gas is heated to the virial temperature at an accretion shock ( e.g. , * ? ? ?
these halos may provide most of the fuel for long - term star formation in these galaxies @xcite , but their predicted properties are sensitive to the input physics , which can be constrained by the measurable properties of the gas . based on work over the past several years , we know that these extended halos exist , including around the milky way @xcite .
the extent and luminosity of the hot gas implies that it has a similar mass to the stellar disk , and therefore could play an important role in galaxy evolution ..
Please generate the next two sentences of the article | thus , it is important to measure the properties of the hot gas beyond mass and temperature ( such as metallicity and density or velocity structure ) .
however , hot halos are faint and the measurable x - ray luminosity can be dominated by stellar feedback ejecta near the disk @xcite , which makes these measurements difficult . only in the milky way can one measure the structure , temperature , metallicity , and kinematics of the hot gas through emission and absorption lines @xcite , but kinematic constraints from prior studies @xcite are weak . |
3,211 | Suppose that you have an abstract for a scientific paper: in this article we derive a strong version of the pontryagin maximum principle for general nonlinear optimal control problems on time scales in finite dimension .
the final time can be fixed or not , and in the case of general boundary conditions we derive the corresponding transversality conditions . our proof is based on ekeland s variational principle . our statement and comments clearly show the distinction between right - dense points and right - scattered points .
at right - dense points a maximization condition of the hamiltonian is derived , similarly to the continuous - time case . at right - scattered points
a weaker condition is derived , in terms of so - called stable @xmath0-dense directions .
we do not make any specific restrictive assumption on the dynamics or on the set @xmath0 of control constraints .
our statement encompasses the classical continuous - time and discrete - time versions of the pontryagin maximum principle , and holds on any general time scale , that is any closed subset of @xmath1 .
* keywords : * pontryagin maximum principle ; optimal control ; time scale ; transversality conditions ; ekeland s variational principle ; needle - like variations ; right - scattered point ; right - dense point .
* ams classification : * 34k35 ; 34n99 ; 39a12 ; 39a13 ; 49k15 ; 93c15 ; 93c55 . .
And you have already written the first three sentences of the full article: optimal control theory is concerned with the analysis of controlled dynamical systems , where one aims at steering such a system from a given configuration to some desired target one by minimizing or maximizing some criterion . the pontryagin maximum principle ( denoted in short pmp ) , established at the end of the fifties for finite dimensional general nonlinear continuous - time dynamics
( see @xcite , and see @xcite for the history of this discovery ) , is the milestone of the classical optimal control theory .
it provides a first - order necessary condition for optimality , by asserting that any optimal trajectory must be the projection of an extremal ..
Please generate the next two sentences of the article | the pmp then reduces the search of optimal trajectories to a boundary value problem posed on extremals . optimal control theory , and in particular the pmp , have an immense field of applications in various domains , and it is not our aim here to list them .
we refer the reader to textbooks on optimal control such as @xcite for many examples of theoretical or practical applications of optimal control , essentially in a continuous - time setting . right after this discovery |
3,212 | Suppose that you have an abstract for a scientific paper: we report a high - statistics measurement of the relative branching fraction @xmath0(@xmath1)/ @xmath0(@xmath2 ) .
a 357 fb@xmath3 data sample collected with the belle detector at the kekb asymmetric - energy @xmath4 collider was used for the analysis .
the relative branching fraction @xmath0(@xmath1)/ @xmath0(@xmath2 ) is determined with an accuracy comparable to the latest world average value . .
And you have already written the first three sentences of the full article: this measurement is the first step towards a high - statistics dalitz - plot analysis of the @xmath1 decay .
the latter could give insight into the controversy on the s - wave @xmath5 contribution in these decays @xcite , as well as a sensitive study of the @xmath6 violation in the neutral d meson system .
knowledge of @xmath0(@xmath7)/@xmath0(@xmath8 ) ( also based on the @xmath1 dalitz analysis ) could improve our understanding of the apparent discrepancy of the measured two - body branching fractions ( @xmath9 kk , @xmath10 ) with the theoretical expectations @xcite ..
Please generate the next two sentences of the article | the accuracy of the value of @xmath0(@xmath1 ) as reported in pdg04 @xcite is poor .
using a large data sample of @xmath11 decays accumulated with the belle detector , we provide a significantly improved measurement using the @xmath2 decay mode for normalization . since both decay modes involve a neutral pion and the same number of charged tracks in the final state , several sources of the systematic uncertainties are avoided in a determination of the relative branching fraction . |
3,213 | Suppose that you have an abstract for a scientific paper: the continuous packing of a flexible rod in two - dimensional cavities yields a countable set of interacting domains that resembles non - equilibrium cellular systems and belongs to a new class of light - weight material .
however , the link between the length of the rod and the number of domains requires investigation especially in the case of non - simply connected cavities , where the number of avoided regions emulates an effective topological temperature . in the present article
we report the results of an experiment of injection of a single flexible rod into annular cavities in order to find the total length needed to insert a given number of loops ( domains of one vertex ) . using an exponential model to describe the experimental data
we quite minutely analyze the initial conditions , the intermediary behavior , and the tight - packing limit .
this method allows the observation of a new fluctuation phenomenon associated with instabilities in the dynamic evolution of the packing process .
furthermore , the fractal dimension of the global pattern enters the discussion under a novel point of view .
a comparison with the classical problems of the random close packing of disks , and jammed disk packings is made .
keywords : : folded structures , 2d systems , complex packing . .
And you have already written the first three sentences of the full article: the packing of a long flexible rod of diameter @xmath0 into a finite quasi - two - dimensional domain of height @xmath1 yields a network of loops which is a pattern of folds that belongs to a new class of light - weight cellular materials with variable degrees of rigidity and with great potential for application in technology @xcite .
the general problem of a flexible rod confined in a two - dimensional cavity belongs to the context of elastic rods constrained to move on surfaces @xcite .
the structures formed in these circumstances have a high surface / bulk ratio , and they extend the field of evolving non - equilibrium cellular systems composed of interacting domains separated by thin boundaries endowed with line energy @xcite.
Please generate the next two sentences of the article | . new results on this subject may also be of interest in the study of shape memory materials using elastoplastic alloy wires @xcite among others @xcite .
since the rod bends when inserted into the cavity and divides the available area into geometric domains , we can perform a direct comparison between the continuous packing and the discrete number of cells . in this context , the present study deals with the length @xmath2 required to build a given number @xmath3 of loops ( domains with one vertex ) . at the beginning of the injection , |
3,214 | Suppose that you have an abstract for a scientific paper: photon coincidence spectroscopy relies on detecting multiphoton emissions from the combined atom - cavity system in atomic beam cavity quantum electrodynamics experiments .
these multiphoton emissions from the cavity are nearly simultaneous approximately on the cavity lifetime scale .
we determine the optimal time for the detection window of photon pairs in two - photon coincidence spectroscopy .
if the window time is too short , some photon pairs will not be detected ; if the window time is too long , too many nearly coincident independent single photons will be falsely interpreted as being a photon pair . .
And you have already written the first three sentences of the full article: cavity quantum electrodynamics ( cqed ) has continued to develop rapidly , driven both by recent experimental successes and by the promise of exciting new applications .
advances in atom cooling techniques , as well as development of high - q optical cavities with large dipole coupling , have enabled testing of the strong - coupling regime of cqed @xcite .
single - atom experiments are now feasible @xcite , and the possibility of trapping atoms in optical cavities is tantalisingly close @xcite ..
Please generate the next two sentences of the article | potential applications include quantum logic gates @xcite .
applications of cqed rely critically on the quantum effects , namely the entanglement between the field degree of freedom and the internal electronic state of the atom @xcite . |
3,215 | Suppose that you have an abstract for a scientific paper: dem analysis is a major diagnostic tool for stellar atmospheres . but both its derivation and its interpretation are notably difficult because of random and systematic errors , and the inverse nature of the problem .
we use simulations with simple thermal distributions to investigate the inversion properties of sdo / aia observations of the solar corona .
this allows a systematic exploration of the parameter space and using a statistical approach , the respective probabilities of all the dems compatible with the uncertainties can be computed . following this methodology ,
several important properties of the dem inversion , including new limitations , can be derived and presented in a very synthetic fashion . in this first paper
, we describe the formalism and we focus on isothermal plasmas , as building blocks to understand the more complex dems studied in the second paper .
the behavior of the inversion of aia data being thus quantified , and we provide new tools to properly interpret the dem .
we quantify the improvement of the isothermal inversion with 6 aia bands compared to previous euv imagers .
the maximum temperature resolution of aia is found to be 0.03 @xmath0 , and we derive a rigorous test to quantify the compatibility of observations with the isothermal hypothesis .
however we demonstrate limitations in the ability of aia alone to distinguish different physical conditions . .
And you have already written the first three sentences of the full article: the differential emission measure ( dem ) diagnostic technique offers crucial information about the thermal structuring of the solar and stellar atmospheres , providing a measure of the temperature distribution of the plasma along the line of sight ( los ) .
however , to derive the dem from a set of observations is a complex task , due to the inverse nature of the problem , and the understanding of its robustness and accuracy is still relevant today ( e.g. * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | spectrometers are by nature better suited to dem analysis than broad band imagers .
but , because these latter generally offer a higher signal to noise ratio over a larger field of view ( fov ) , dem codes have nevertheless been applied to the three coronal bands of the extreme - ultraviolet imaging telescope ( eit ) @xcite or the transition region and coronal explorer ( trace , * ? ? |
3,216 | Suppose that you have an abstract for a scientific paper: it is anticipated that future space - born missions , such as _ gaia _ , will be able to determine in optical domain positions of more than 100 , 000 bright quasars with sub - mas accuracies that are comparable to very long baseline interferometry ( vlbi ) accuracies . comparisons of coordinate systems from space - born missions and from vlbi will be very important , first for investigation of possible systematic errors , second for investigation of possible shift between centroids of radio and optical emissions in active galaxy nuclea . in order to make such a comparison more robust , a program of densification of the grid of radio sources detectable with both vlbi and _ gaia _ was launched in 2006 . in the second observing campaign a set of 290 objects from the list of 398 compact extragalactic radio sources with declinations @xmath0 was observed with the vlba+evn in 20102011 with the primary goal of producing their images with milliarcsecond resolution .
these sources are brighter than 18 magnitude at v band . in this paper
coordinates of observed sources have been derived with milliarcsecond accuracies from analysis of these vlbi observations following the method of absolute astrometry and their images were produced .
the catalogue of positions of 295 target sources and estimates of their correlated flux densities at 2.2 and 8.4 ghz is presented .
the accuracies of source coordinates are in a range of 2 to 200 mas , with the median 3.2 mas . .
And you have already written the first three sentences of the full article: the method of very long baseline interferometry ( vlbi ) first proposed by @xcite allows us to derive source positions with nanoradian precision ( 1 nrad @xmath1 0.2 mas ) . since 1971
when the first catalogue of source coordinates determined with vlbi was published @xcite , the number of extragalactic compact radio sources which positions were derived using vlbi under absolute astrometry observing programs grew from 35 objects to 7215 in 2012 . for 95% these sources , accuracies of their positions are in a range of 0.05 to 6.5 mas with the median 0.5 mas .
these sources form a dense grid on the sky that can be used for many applications , such as differential astrometry , phase - referencing vlbi observations of weak objects , space navigation , earth orientation parameter determination , and space geodesy ..
Please generate the next two sentences of the article | however , high accuracy of positions of these objects can be exploited _ directly _ only by applications that utilize the vlbi technique .
applications that use different observational techniques can benefit from the high accuracy of vlbi positions only _ indirectly _ by observing common objects from the vlbi catalogue with instruments at other wavelengths . |
3,217 | Suppose that you have an abstract for a scientific paper: we construct @xmath0 supersymmetric fractional branes on the @xmath1 orientifold . intersecting stacks of such branes
are needed to build a supersymmetric standard model .
if @xmath2 are the stacks that generate the @xmath3 and @xmath4 gauge particles , then , in order to obtain _ just _ the chiral spectrum of the ( supersymmetric ) standard model ( with non - zero yukawa couplings to the higgs mutiplets ) , it is necessary that the number of intersections @xmath5 of the stacks @xmath6 and @xmath7 , and the number of intersections @xmath8 of @xmath6 with the orientifold image @xmath9 of @xmath7 satisfy @xmath10 or @xmath11 .
it is also necessary that there is no matter in symmetric representations of the gauge group , and not too much matter in antisymmetric representations , on either stack .
we provide a number of examples having these properties .
different lattices give different solutions and different physics .
0.35 cm 0.2 cm _ department of physics & astronomy , university of sussex + _ _ brighton bn1 9qh , u.k . +
_ 2.5 cm .
And you have already written the first three sentences of the full article: one of the main phenomenological attractions of using d - branes is that they permit a `` bottom - up '' approach to constructing the standard model from type ii string theory .
open strings that begin and end on a stack @xmath6 of @xmath12 d - branes generate the gauge bosons of a ( supersymmetric ) @xmath13 gauge theory living in the world volume of the d - branes . in the original bottom - up models
@xcite a stack of d3-branes is placed at an orbifold @xmath14 singularity and the standard model gauge group ( possibly augmented by additional @xmath15 factors ) is obtained by choosing a suitable embedding @xmath16 of the action of the generator @xmath17 of the orbifold point group @xmath18 on the chan - paton indices of the d3-branes . besides the gauge bosons , fermionic matter also survives the orbifold projection ..
Please generate the next two sentences of the article | so long as only d3-branes are retained , the fermion spectrum generally makes the non - abelian gauge symmetries anomalous , reflecting the fact that a general collection of d3-branes has uncancelled ramond - ramond ( rr ) tadpoles .
the required cancellation is achieved by introducing d7-branes , which generate further gauge symmetries , and additional fermions . when all tadpoles are cancelled , so are the gauge anomalies . |
3,218 | Suppose that you have an abstract for a scientific paper: it is well - known that entanglement of formation ( eof ) and relative entropy of entanglement ( ree ) are exactly identical for all two - qubit pure states even though their definitions are completely different .
we think this fact implies that there is a veiled connection between eof and ree . in this context , we suggest a procedure , which enables us to compute ree from eof without relying on the converse procedure .
it is shown that the procedure yields correct ree for many symmetric mixed states such as bell - diagonal , generalized vedral - plenino , and generalized horodecki states .
it also gives a correct ree for less symmetric vedral - plenio - type state .
however , it is shown that the procedure does not provide correct ree for arbitrary mixed states . .
And you have already written the first three sentences of the full article: entanglement of formation ( eof)@xcite and relative entropy of entanglement ( ree)@xcite are two major entanglement monotones for bipartite systems . for pure states @xmath0 the eof @xmath1 is defined as a von neumann entropy of its subsystem @xmath2 . on the contrary , ree is defined as minimum value of the relative entropy with separable states ; @xmath3 where @xmath4 is a set of separable states , it is called `` distance entanglement measure '' .
another example of the distance entanglement measure is a geometric entanglement measure defined as @xmath5 , where @xmath6 is a maximal overlap of a given state @xmath7 with the nearest product state@xcite . ] .
it was shown in ref.@xcite that @xmath8 is a upper bound of the distillable entanglement@xcite ..
Please generate the next two sentences of the article | the separable state @xmath9 , which yields a minimum value of the relative entropy is called the closest separable state ( css ) of @xmath10 .
surprising fact , at least for us , is that although definitions of eof and ree are completely different , they are exactly same for all pure states@xcite . |
3,219 | Suppose that you have an abstract for a scientific paper: we develop a general method to evaluate the kondo temperature in a multilevel quantum dot that is weakly coupled to conducting leads .
our theory reveals that the kondo temperature is strongly enhanced when the intradot energy - level spacing is comparable or smaller than the charging energy .
we propose an experiment to test our result , which consists of measuring the size - dependence of the kondo temperature . _
introduction. _ the kondo effect , a many - body phenomenon that emerges from the interaction between localized and itinerant fermionic degrees of freedom , is characterized by a low - temperature infrared ( ir ) divergence in perturbative calculations of physical observables such as resistivity and magnetic susceptibility@xcite .
this ir divergence is controlled by an ultraviolet ( uv ) cutoff @xmath0 that appears in the expression for the kondo temperature via @xmath1 , where @xmath2 is the kondo coupling and @xmath3 is the fermi level density of states per spin for itinerant carriers . such expression for @xmath4
is generally valid for @xmath5 and can be derived perturbatively starting from the venerable kondo hamiltonian @xcite , @xmath6
. an accurate microscopic theory of @xmath2 and @xmath0 provides crucial guidance for experimental explorations of strongly correlated electron systems . a precise way to quantify
@xmath4 is to work with a `` first - principles '' microscopic model that reduces to @xmath7 at energy scales below @xmath0 .
quite generally this first - principles hamiltonian can be written as @xmath8 , where @xmath9 captures the hybridization between the localized and itinerant degrees of freedom .
a perturbation theory calculation of physical observables in @xmath9 then yields hallmark kondo - like divergences , with @xmath0 and @xmath2 unequivocally determined in terms of the microscopic parameters of @xmath10 .
perhaps the first author to successfully implement the aforementioned scheme was haldane@xcite , who evaluated the magnetic susceptibility....
And you have already written the first three sentences of the full article: in this supplementary section we present a list of virtual processes that contribute to the first term of eq.(9 ) in the main text .
table i corresponds to the single - level anderson model , whereas tables ii - iv dwell on the universal hamiltonian .
in addition , we present the dimensionless integral that gives rise to @xmath21 ( defined by eq ..
Please generate the next two sentences of the article | 15 in the main text ) : @xmath166 where @xmath167 and @xmath168 .
( [ eq : f ] ) can be derived by adding the @xmath169 transition amplitudes of tables ii - iv along with the second and third term of eq.(9 ) in the main text , with @xmath136 . |
3,220 | Suppose that you have an abstract for a scientific paper: we used a torsion pendulum containing @xmath0 polarized electrons to search new interactions that couple to electron spin .
we limit cp - violating interactions between the pendulum s electrons and unpolarized matter in the earth or the sun , test for rotation and boost - dependent preferred - frame effects using the earth s rotation and velocity with respect to the entire cosmos , and search for exotic velocity - dependent potentials between polarized electrons and unpolarized matter in the sun and moon .
we find @xmath1-violating parameters @xmath2 and @xmath3 for @xmath4au .
we test for preferred - frame interactions of the form @xmath5 , @xmath6 , or @xmath7 , where @xmath8 is the velocity of the earth with respect to the cmb restframe and @xmath9 represent the equatorial inertial coordinates @xmath10,@xmath11 and @xmath12 .
we constrain all 3 components of @xmath13 , obtaining @xmath14 upper limits @xmath15 ev and @xmath16 ev that may be compared to the benchmark value @xmath17 ev . interpreting our constraint on @xmath18 in terms of non - commutative geometry , we obtain an upper bound of @xmath19 on the minimum observable area , where @xmath20 gev ) is the grand unification length . we find that @xmath21 ev .
all 9 components of @xmath22 are constrained at the @xmath23 to @xmath24 ev level .
we determine 9 linear combinations of parameters of the standard model extension ; rotational - noninvariant and boost - noninvariant terms are limited at roughly the @xmath25 gev and @xmath26 gev levels , respectively .
finally , we find that the gravitational mass of an electron spinning toward the galactic center differs by less than about 1 part in @xmath27 from an electron spinning in the opposite direction . as a byproduct of this work , the density of polarized electrons in sm@xmath28co@xmath29 was measured to be @xmath30 at a field of 9.6 kg . .
And you have already written the first three sentences of the full article: this paper describes constraints on possible new spin - coupled interactions using a torsion pendulum containing @xmath31 polarized electrons .
several rather different considerations motivated this work . general relativity ( the classical theory that forms the standard model of gravity ) does not in itself make predictions about the gravitational properties of intrinsic spin a quantum mechanical effect with no classical analog .
because the classic equivalence - principle and inverse - square - law experiments all used unpolarized test bodies they can shed no light on this issue ..
Please generate the next two sentences of the article | in addition , these `` fifth force '' experiments were completely insensitive to the purely spin - dependent forces arising from the first - order exchange of unnatural parity ( @xmath32 , @xmath33 , etc ) bosons .
lastly , the spin pendulum provided a means to search for a new class of preferred - frame effects that involve intrinsic spin . |
3,221 | Suppose that you have an abstract for a scientific paper: we experimentally address the wave - vector and polarization dependence of the internal conical refraction phenomenon by demonstrating that an input light beam of elliptical transverse profile refracts into two beams after passing along one of the optic axes of a biaxial crystal , _
i.e. _ it exhibits double refraction instead of refracting conically .
such double refraction is investigated by the independent rotation of a linear polarizer and a cylindrical lens .
expressions to describe the position and the intensity pattern of the refracted beams are presented and applied to predict the intensity pattern for an axicon beam propagating along the optic axis of a biaxial crystal . + * ocis * : ( 160.1190 ) anisotropic optical materials ; ( 260.1180 ) crystal optics ; ( 260.1140 ) birefringence . .
And you have already written the first three sentences of the full article: light beams propagating in optically uniaxial crystals , with two principal dielectric indexes , exhibit birefringence or double refraction , _
i.e. _ decomposition of an input beam into ordinary ( o ) and extraordinary ( e ) beams with orthogonal linear polarizations .
the extraordinary beam is laterally shifted with respect to the ordinary one , being this shift equal to zero when the input beam propagates along the optic axis ..
Please generate the next two sentences of the article | the intensity distribution between the o- and e- beams , expressed by the malus law , depends only on one parameter : the relative orientation of the crystal with respect to the polarization plane of the input beam .
biaxial crystals ( bcs ) , with three different principal dielectric indexes and two optic axes , also exhibit double refraction . |
3,222 | Suppose that you have an abstract for a scientific paper: the properties of certain networks are determined by hidden variables that are not explicitly measured .
the conditional probability ( propagator ) that a vertex with a given value of the hidden variable is connected to k of other vertices determines all measurable properties .
we study hidden variable models and find an averaging approximation that enables us to obtain a general analytical result for the propagator .
analytic results showing the validity of the approximation are obtained .
we apply hidden variable models to protein - protein interaction networks ( pins ) in which the hidden variable is the association free - energy , determined by distributions that depend on biochemistry and evolution .
we compute degree distributions as well as clustering coefficients of several pins of different species ; good agreement with measured data is obtained . for the human interactome
two different parameter sets give the same degree distributions , but the computed clustering coefficients differ by a factor of about two .
this shows that degree distributions are not sufficient to determine the properties of pins .
= 10000 0.5 cm .
And you have already written the first three sentences of the full article: physicists have recently shown that network analysis is a powerful tool to study the statistical properties of complex biological , technological and social systems of diverse kinds@xcite .
many networks exhibit a scale - free degree distribution in which the probability @xmath0 that a vertex is connected to @xmath1 other vertices falls as a power @xmath2 .
this property is not sufficient to completely describe natural networks because such systems also exhibit degree correlations the degrees of the vertices at the end points of any given edge are not independent @xcite ..
Please generate the next two sentences of the article | it is not surprising that natural systems depend on properties that do not appear explicitly in degree distributions . in particular , protein interaction networks depend on the availability of sufficient binding free energy@xcite to cause interactions to occur ( links between vertices to exist ) .
caldarelli _ et al . |
3,223 | Suppose that you have an abstract for a scientific paper: we propose a novel mathematical approach for the calculation of near - zero energy states by solving potentials which are isospectral with the original one . for any potential , families of strictly isospectral potentials ( with very different shape ) having desirable and adjustable features
are generated by supersymmetric isospectral formalism .
the near - zero energy efimov state in the original potential is effectively trapped in the deep well of the isospectral family and facilitates more accurate calculation of the efimov state . application to the first excited state in @xmath0he trimer is presented . .
And you have already written the first three sentences of the full article: it was proposed by efimov in 1970 that if two spinless neutral bosons interact resonantly then the addition of a third identical particle leads to the appearance of an infinite number of bound three - body energy levels @xcite .
this occurs simultaneously with the divergence of the @xmath1-wave scattering length @xmath2 , associated with appearance of an additional zero - energy two - body bound state .
hence highly exotic efimov states appear when there is a zero or near - zero energy two - body bound state . for a long time.
Please generate the next two sentences of the article | there was no clear signature of efimov states in any naturally occuring trimer system .
efimov states are not possible in atomic systems due to the long range coulomb interaction , however it may exist in the system of spinless neutral atoms . |
3,224 | Suppose that you have an abstract for a scientific paper: we study theoretically the responses of the dynamically corrected gates to time - dependent noises in the exchange - only spin qubit system .
we consider @xmath0 noises having spectra proportional to @xmath1 , where the exponent @xmath2 indicates the strength of correlation within the noise .
the quantum gate errors due to noises are extracted from a numerical simulation of randomized benchmarking , and are compared between the application of uncorrected operations and that of dynamically corrected gates robust against the hyperfine noise .
we have found that for @xmath3 , the dynamically corrected gates offer considerable reduction in the gate error and such reduction is approximately two orders of magnitude for the experimentally relevant noise exponent . on the other hand ,
no improvement of the gate fidelity is provided for @xmath4 .
this critical value @xmath5 is comparatively larger than that for the cases for the singlet - triplet qubits .
the filter transfer functions corresponding to the dynamically corrected gates are also computed and compared to those derived from uncorrected pulses .
our results suggest that the dynamically corrected gates are useful measures to suppress the hyperfine noise when operating the exchange - only qubits . .
And you have already written the first three sentences of the full article: spin qubits confined in semiconductor quantum dots are promising candidates for quantum computing@xcite due to their demonstrated long coherence time , high control fidelities@xcite as well as expected scalability .
a natural approach , proposed by loss and divincenzo,@xcite is to encode one qubit using the spin up and down states of a single electron .
however , difficulties in performing esr - type single electron spin rotations@xcite in this type of the qubit have led researchers to propose alternative ways to encode qubits in the collective states of two or more electrons.@xcite the singlet - triplet qubit is the simplest qubit that can be controlled all - electrically via the exchange interaction,@xcite but its full control still requires a magnetic field gradient.@xcite in a seminal paper,@xcite divincenzo proposed a qubit employing certain three - spin states as the qubit , which can be controlled solely by the exchange interaction , and is thus termed as the `` exchange - only '' qubit ..
Please generate the next two sentences of the article | the exchange - only qubit , together with its variant the resonant exchange qubit , has been experimentally demonstrated at the single - qubit level.@xcite nevertheless , hyperfine - mediated nuclear spin fluctuations@xcite as well as charge noises@xcite contribute to decoherence , preventing the implementation of more complicated operations required to operate two or more qubits , despite extensive theoretical studies on the two qubit gates.@xcite a comprehensive understanding of the interaction between noises and controls is therefore of crucial importance for the field to progress .
dynamically corrected gates@xcite ( dcgs ) are useful measures to combat decoherence . |
3,225 | Suppose that you have an abstract for a scientific paper: statistics of tunneling rates in the presence of chaotic classical dynamics is discussed on a realistic example : a hydrogen atom placed in parallel uniform static electric and magnetic fields , where tunneling is followed by ionization along the fields direction .
depending on the magnetic quantum number , one may observe either a standard porter - thomas distribution of tunneling rates or , for strong scarring by a periodic orbit parallel to the external fields , strong deviations from it .
for the latter case , a simple model based on random matrix theory gives the correct distribution . .
And you have already written the first three sentences of the full article: after many years of intensive research in the `` quantum chaos area '' it is now commonly accepted that the quantum behavior of complex systems may be strongly correlated with the character of their classical motion @xcite . even such a purely quantum phenomenon as tunneling
may be profoundly affected by chaotic classical dynamics . for regular systems a smooth dependence of the tunneling rate on parameters
is expected . in the presence of chaotic motion ,.
Please generate the next two sentences of the article | the tunneling rates typically strongly fluctuate , the game is then to identify both the average behavior and the statistical properties of the fluctuations .
imagine the situation when the wavefunction is predominantly localized in a region of regular motion . |
3,226 | Suppose that you have an abstract for a scientific paper: we present recent measurements of neutrino charged current quasi - elastic ( ) scattering , .
measurements of on carbon near 1 gev by miniboone and sciboone , as well as measurements on iron at 3 gev by minos , disagree with current interaction models , while measurements at higher energies on carbon by nomad show excellent agreement with those same models .
neutrino , cross - section , charged - current quasi - elastic .
And you have already written the first three sentences of the full article: neutrino physics is entering a new era of precision measurements of oscillation parameters .
the measured value of the atmospheric neutrino mass splitting is such that current and future accelerator neutrino beams are best tuned to oscillation physics with neutrino energies in the few - gev region .
however , the precision of neutrino interaction cross - sections is not commensurate with the goals of the next generation of neutrino oscillation experiments @xcite ..
Please generate the next two sentences of the article | moreover , recent measurements have exposed serious shortcomings in the current theoretical models describing neutrino - nucleus interactions .
one of the largest interaction processes in the few - gev region is quasi - elastic scattering ( ) , . |
3,227 | Suppose that you have an abstract for a scientific paper: we present radial stellar population parameters for a subsample of 12 galaxies from the 36 isolated early - type galaxies of reda et al . using new long - slit spectra ,
central values and radial gradients for the stellar age , metallicity [ z / h ] and @xmath0-element abundance [ e / fe ] are measured .
similarly , the central stellar population parameters are derived for a further 5 isolated early - type galaxies using their lick indices from the literature . on average
, the seventeen isolated galaxies have mean central [ z / h]@xmath1 and [ e / fe]@xmath1 of @xmath2 and @xmath3 respectively and span a wide range of ages from 1.7 to 15 gyrs .
we find that isolated galaxies follow similar scaling relations between central stellar population parameters and galaxy velocity dispersion to their counterparts in high density environments .
however , we note a tendency for isolated galaxies to have slightly younger ages , higher metallicities and lower abundance ratios . such properties are qualitatively consistent with the expectation of an extended star formation history for galaxies in lower density environments .
generally we measure constant age and [ e / fe ] radial gradients .
however , three galaxies show remarkable positive age gradients and two galaxies have negative age gradients .
we find that the age gradients anti - correlate with the central galaxy age .
thus as a young starburst evolves , the age gradient flattens from positive to almost zero .
metallicity gradients range from near zero to strongly negative . for our high mass galaxies ( @xmath4 km / s )
metallicity gradients are shallower with increasing mass .
such behaviour is not predicted in dissipational collapse models but might be expected in multiple mergers .
the metallicity gradients are also found to be correlated with the central age and metallicity , as well as to the age gradients . in conclusion ,
our stellar population data for a sample of isolated early - type galaxies are more compatible with an....
And you have already written the first three sentences of the full article: the stellar population properties of early - type galaxies ( e.g. age , metallicity and @xmath0-element abundance [ e / fe ] ) provide crucial clues to their evolutionary history .
most work to date has concentrated on galaxy central regions . while useful , such data only sample a small fraction of the galaxy mass and do not provide any radial gradient information .
radial gradients can help discriminate between different formation models ..
Please generate the next two sentences of the article | for example , dissipational collapse models ( larson 1974 ; carlberg 1984 ; kawata & gibson 2003 ) predict strong metallicity gradients that correlate with galaxy mass , whereas mergers tend to result in shallow gradients ( white 1980 ; bekki & shioya 1999 ) with little galaxy mass dependence . as [ e / fe ]
may be an indicator of star formation timescale , a positive gradient indicates outside - in formation and a negative one the opposite ( e.g. ferreras & silk 2002 ) . |
3,228 | Suppose that you have an abstract for a scientific paper: about 30.5 days of nearly uninterrupted broadband photometry of the solar - type star @xmath0 ceti , obtained with the most ( microvariability & oscillations of stars ) satellite , shows evidence for two large starspots with different rotation periods of 8.9 and approximately 9.3 days ( @xmath1 ) .
ground based measurements in 2002 and 2003 of ca ii h & k emission reveal variations in chromospheric activity with a period of about 9.3 days .
the data were obtained during the most commissioning phase . when the data are combined with historical observations ,
they indicate that the 9.3-day spot has been stable in its period for over 30 years .
the photometry , with a sampling rate of approximately once per minute , was also used to search for acoustic ( p - mode ) oscillations in the star .
we detect no clear evidence for p - modes in the @xmath0 ceti photometry , with a noise level around 7 9 @xmath2mag at frequencies in the range 0.5 4 mhz ( 3@xmath3 detection limit of 21 27 @xmath2mag ) .
there were no flares or planetary transits during the 30.5 days of most monitoring with light amplitudes greater than 2 mmag ( durations greater than 200 minutes ) and 3 mmag ( @xmath4 min durations ) . while this rules out any close - in planets of @xmath50.5 jupiter diameters with an orbital inclination close to @xmath6 , the scatter in differential radial velocities permit a close giant planet in a more highly inclined orbit .
And you have already written the first three sentences of the full article: the production of solar flares , the evolution and migration of sunspots , and the very origin of the sun s magnetic field are all believed to be associated with differential rotation beneath and at the solar surface . to test models of stellar dynamos , measurements of differential rotation in other stars are necessary for correlation with other parameters like magnetic variability and chromospheric activity .
surface differential rotation ( sdr ) can be easily observed in the sun with detailed observations going back to @xcite and subsurface rotation has been inferred from helioseismic data of the sun s 5-minute p - mode oscillations ( e.g. , @xcite ) .
however , it is a challenge to observe sdr directly at the surfaces of other stars . with the notable exception of ek dra , where two spot modulations differing in period by 5.5% are simultaneously visible @xcite , evidence for sdr in most solar - type stars with prominent starspots is seen only by comparing data over many years ..
Please generate the next two sentences of the article | light variations ascribed to rotational modulation sometimes change in period from epoch to epoch , and the most natural explanation is that the dominant spot systems appear at different latitudes and move with different rotation periods ( e.g. , @xcite ; @xcite ) .
doppler imaging of some solar - type stars from epoch to epoch has also revealed evidence for sdr ( see reviews by @xcite and @xcite ) and in at least one case , the rapidly rotating k dwarf ab doradus , sdr was observed in the doppler maps in only a few consecutive rotations ( @xcite ) . |
3,229 | Suppose that you have an abstract for a scientific paper: the magnetic field structure associated with edge localised ideal ballooning mode ( elm ) bursts is analysed by nonlinear gyrofluid computation .
the linear growth phase is characterised by the formation of small scale magnetic islands .
ergodic magnetic field regions develop near the end of the linear phase when the instability starts to perturb the equilibrium profiles .
the nonlinear blow - out gives rise to an ergodisation of the entire edge region .
the time - dependent level of ergodicity is determined in terms of the mean radial displacement of a magnetic field line .
the ergodicity decreases again during the nonlinear turbulent phase of the blow - out in dependence on the degrading plasma beta in the collapsing plasma pedestal profile . .
And you have already written the first three sentences of the full article: the steep gradients related to the edge transport barrier in tokamak h - mode plasmas facilitate the growth of edge localised modes ( elms ) involving repetitive eruption of particles and energy @xcite .
the largest and most vehement of such events , classified as `` type - i '' elms , are commonly associated with the onset of ideal or peeling ballooning modes in edge pedestals @xcite . in future large tokamak devices like iter , the heat flux associated with type i elms
is estimated to seriously damage the plasma facing components ( pfcs ) and methods for the suppression or at least effective mitigation of the disruptions are essential for an economic steady state operation @xcite ..
Please generate the next two sentences of the article | one of the most promising elm mitigation methods is the external application of resonant magnetic perturbations ( rmps ) which has been observed to increase the elm frequency and to reduce the heat load on the pfcs @xcite .
models for the physics underlying the elm mitigation by rmps have been developed @xcite . |
3,230 | Suppose that you have an abstract for a scientific paper: motivated by the recent experiment on kagome - lattice antiferromagnets , we study the zero - field ordering behavior of the antiferromagnetic classical heisenberg model on a uniaxially distorted kagome lattice by monte carlo simulations . a first - order transition , which has no counterpart in the corresponding undistorted model , takes place at a very low temperature .
origin of the transition is ascribed to a cooperative proliferation of topological excitations inherent to the model .
renewed interest has recently been paid to novel ordering properties of geometrically frustrated magnets @xcite .
two - dimensional ( 2d ) kagome lattice , a corner - sharing network of regular triangles , is a typical example of such geometrically frustrated lattices .
many theoretical works have been performed to elucidate the ordering of the antiferromagnetic ( af ) heisenberg model on this lattice for both cases of quantum @xmath0 @xcite and classical @xmath1 @xcite spins . in the quantum @xmath0 case , although there seems to be a consensus among researchers that the ground state of the model lacks in the conventional af long - range order , there still exists a considerable diversity in the view about the nature of its ground state @xcite . in the classical @xmath1 case ,
any combination of the local 120-degrees spin structure on a constituent triangle is allowed as its ground state , leading to the massive degeneracy .
the effect of `` order from disorder '' is operative at low temperatures , which favors at the harmonic level the coplanar states , or the spin nematic states , where all spins are contained on a common plane in the spin space @xcite .
yet , the coplanar ground states themselves are heavily degenerate , the degeneracy of @xmath2 ( @xmath3 the number of spins ) . in order to determine which coplanar state is realized in the @xmath4 limit , nonlinear excitations beyond the harmonic level need to be invoked .
the model selects among them the so - called @xmath5 state @xcite .
....
And you have already written the first three sentences of the full article: in this section , we explain how we check equilibration in our monte carlo ( mc ) simulations .
since our simulations are performed at very low temperatures , an appropriate check of equilibration is crucially important .
the standard check might be to monitor the stability of various observables as a function of mc time for successively longer observation times , which we do perform ..
Please generate the next two sentences of the article | in addition to this standard test , we also perform the following procedure for an additional check of equilibration . .
, width=302 ] as mentioned in the main text , we take our data based on the combination of the heat - bath ( hb ) method and the over - relaxation method . |
3,231 | Suppose that you have an abstract for a scientific paper: for any link and for any modulus @xmath0 we introduce an equivalence relation on the set of non - trivial @xmath0-colorings of the link ( an @xmath0-coloring has values in @xmath1 ) . given a diagram of the link , the equivalence class of a non - trivial @xmath0-coloring is formed by each assignment of colors to the arcs of the diagram that is obtained from the former coloring by a permutation of the colors in the arcs which preserves the coloring condition at each crossing .
this requirement implies topological invariance of the equivalence classes .
we show that for a prime modulus the number of equivalence classes depends on the modulus and on the rank of the coloring matrix ( with respect to this modulus ) .
keywords : links , colorings , equivalence classes of colorings msc 2010 : 57m27 .
And you have already written the first three sentences of the full article: given a diagram @xmath2 of a link and a modulus @xmath3 , a ( fox ) coloring ( @xcite ) is an assignment of integers modulo @xmath0 to the arcs of @xmath2 such that at each crossing twice the color assigned to the over - arc equals the sum of the colors assigned to the under - arcs , modulo @xmath0 ( see figure [ fig : xtop ] ) .
for each diagram and for each modulus @xmath3 there is always at least one solution to this problem namely by assigning the same color ( i.e. , integer modulo @xmath0 ) to each and every arc of the diagram ; thus there are exactly @xmath0 such solutions modulo @xmath0 .
these are the trivial solutions modulo @xmath0 i.e. , the so - called trivial @xmath0-colorings of the diagram ..
Please generate the next two sentences of the article | the non - trivial @xmath0-colorings are the solutions , modulo @xmath0 , which involve at least two distinct colors . * remark*. we remark that it is well known that this system of equations is also a system of relations for the first homology group of the 2-fold branched covering along the link ( @xcite , theorem 3.3 ) . in fact
, the fundamental group of the @xmath4-fold branched covering along a link is presented by labeling the arcs of the unoriented link diagram and having relations of the form @xmath5 read off at each crossing when @xmath6 is the label of the over - crossing line . |
3,232 | Suppose that you have an abstract for a scientific paper: we present a comprehensive picture of ( non - critical ) domain growth in model c systems where a non - conserved scalar order parameter is coupled to a conserved concentration field . for quenches into the region
where the ordered and disordered phases coexist , we confirm earlier partial numerical results and find a growth exponent @xmath0 . for quenches into the ordered region , we confirm the theoretical prediction @xmath1 .
finally we discuss the implications of our results for domain growth in the microcanonical @xmath2-model and we offer some criticism of the work of somoza and sagui on the morphology and wetting properties of domains . 2 .
And you have already written the first three sentences of the full article: coarsening has been a object of intensive study over the last decades not only because of its experimental relevance but also because it constitutes what is maybe the simplest case of out - of - equilibrium dynamics . for a scalar order parameter ,
one generally distinguishes the non - conserved case , e.g. the ising model with glauber dynamics ( model a according to the widely - used classification of @xcite ) , from the conserved case , e.g. the ising model with kawasaki dynamics ( model b ) .
it is now well - established that in these cases phase ordering is characterized by a single lengthscale @xmath3 growing algebraically with time ( @xmath4 ) with the growth exponent @xmath5 taking two different values , @xmath1 for the non - conserved / model a case , and @xmath0 for conserved order parameter systems like model b @xcite . here.
Please generate the next two sentences of the article | we are interested in the more complicated and therefore less well understood case of a non - conserved order parameter coupled to a conserved concentration ( so - called model c ) .
examples of this situation can be found in various physical systems , e.g. , intermetallic alloys ( see @xcite and references therein ) , adsorbed layers on solid substrates @xcite and supercooled liquids @xcite . in these systems , |
3,233 | Suppose that you have an abstract for a scientific paper: an interferometric scheme to study abelian geometric phase shift over the manifold su(n)/su(n-1 ) is presented . #
1/#2.1em .5ex-.1em /-.15em.25ex # 1 # 1 .
And you have already written the first three sentences of the full article: the purpose of this contribution is twofold : to review how an su(n ) transformation can be experimentally realized using optical elements , and to show how such an experimental realization can be used to investigate the cyclic evolution of a state over the manifold su(n)/u(n-1 ) .
the bulk of the results will be presented explicitly for su(3 ) ( see @xcite for further details ) and su(4 ) , although it will become clear that the method can be applied to any su(n ) .
recall that cyclic evolution of a wave function yields the original state plus a phase shift , and this phase shift is a sum of a dynamical phase @xmath0 and a geometric ( or topological , or quantal , or berry ) phase @xmath1 shift@xcite ..
Please generate the next two sentences of the article | the geometric phase shift is important not just for quantum systems but also for all of wave physics . thus far , controlled geometric phase experiments , both realized and proposed , have been exclusively concerned with the abelian geometric phase arising in the evolution of u(1)invariant states @xcite here , we generalize the above results to an abelian geometric phase which arises from geodesic transformations of u(n-1)invariant states in su(n)/u(n-1 ) space .
the scheme employs a sequence of optical element , henceforth called su(n ) elements because they perform transformations described by an su(n ) matrix , arranged so that the net result of the sequence cyclically evolves an initial state back to itself up to a phase . |
3,234 | Suppose that you have an abstract for a scientific paper: we report on the measurements of inclusive @xmath0+jets and @xmath1+jets cross sections in proton proton collisions at @xmath2 tev with the atlas detector .
cross sections , in both the electron and muon decay modes of the bosons , are presented as a function of jet multiplicity , the transverse momentum of the jets and the quantity @xmath3 which is the scalar sum of the @xmath4 in the event .
measurements are also presented of the ratios of cross sections .
the measured cross sections are compared to different particle
level predictions , based on perturbative qcd , where the measured @xmath0 + 3jet cross section is for the first time compared with next to leading order calculations .
address = cavendish laboratory , university of cambridge , cambridge , uk . .
And you have already written the first three sentences of the full article: the experimentally clean signatures of @xmath0 and @xmath1bosons make the measurement of these processes in association with jets well suited to test perturbative qcd at the lhc .
the processes allow for comparisons of multi jet production with predictions either from the parton shower approach or from exact multi parton matrix elements ( @xmath5 ) matched with parton showers . in addition , full next to leading order ( @xmath6 ) calculations are also available for comparison with many of the results .
the @xmath7 processes also differ from pure qcd multi jet processes with respect to the scale of the hard interaction , due to the large mass of the electroweak gauge bosons ..
Please generate the next two sentences of the article | measurements of @xmath0/@xmath1+jets are also important to control backgrounds to other measurements at the lhc . in the standard model context ,
one example is the top quark cross section measurements , where @xmath0+jet is often the dominant background . |
3,235 | Suppose that you have an abstract for a scientific paper: we report _ bepposax _ and optical observations of the black hole candidate gx3394 during its x - ray ` off ' state in 1999 . the broad - band ( 0.850 kev ) x - ray emission can be fitted by a single power law with spectral index , @xmath0 .
the observed luminosity is @xmath1 erg s@xmath2 in the 0.510 kev band , which is at the higher end of the flux distribution of black hole soft x - ray transients in quiescence , comparable to that seen in gs2023 + 338 and 4u163047 .
an optical observation just before the _ bepposax _ observation shows the source to be very faint at these wavelengths as well ( @xmath3 , @xmath4 ) . by comparing with previously reported ` off ' and low states ( ls ) , we conclude that the ` off ' state is actually an extension of the ls , i.e. a ls at lower intensities .
we propose that accretion models such as the advection - dominated accretion flows are able to explain the observed properties in such a state .
# 1to 0pt#1 accretion , accretion disks binaries : close black hole physics stars : individual ( gx3394 ) x - rays : stars .
And you have already written the first three sentences of the full article: the black hole candidate gx3394 was discovered by markert et al .
( 1973 ) with the oso7 satellite and was soon noted for its similarity in x - rays to the classical black hole candidate cygx1 ( market et al .
1973 ; maejima et al . 1984 ; dolan et al . 1987 ) ..
Please generate the next two sentences of the article | the source exhibits aperiodic and quasi - periodic modulations on time scales spanning from milliseconds to years over a wide range of wavelengths .
it spends most of the time in the so - called x - ray low state ( ls ) which has a power - law spectrum with spectral index @xmath5 ( ricketts 1983 ; maejima et al . |
3,236 | Suppose that you have an abstract for a scientific paper: we study an isothermal system of semi - degenerate self - gravitating fermions in general relativity .
such systems present mass density solutions with a central degenerate core , a plateau and a tail which follows a power law behaviour @xmath0 .
the different solutions are governed by the free parameters of the model : the degeneracy and temperature parameters at the center , and the particle mass @xmath1 .
we then analyze in detail the free parameter space for a fixed @xmath1 in the kev regime , by studying the one - parameter sequences of equilibrium configurations up to the critical point , which is represented by the maximum in a central density ( @xmath2 ) vs. core mass ( @xmath3 ) diagram .
we show that for fully degenerate cores , the known expression for the critical core mass @xmath4 is obtained , while instead for low degenerate cores , the critical core mass increases showing the temperature effects in a non linear way .
the main result of this work is that when applying this theory to model the distribution of dark matter in galaxies from the very center up to the outer halos , we do not find any critical core - halo configuration of self - gravitating fermions , which be able to explain the super massive dark object in their centers together with an outer halo simultaneously . .
And you have already written the first three sentences of the full article: systems of self - gravitating semi - degenerate fermions in general relativity were studied in @xcite and more recently with applications to dark matter in galaxies in @xcite .
it was shown that , for a given central temperature parameter ( @xmath5 ) in agreement with the corresponding observed halo circular velocity , there are lower bounds for the central degeneracy parameter ( @xmath6 ) and particle mass ( @xmath7 kev ) above which the _ observed _ halo mass and radius are fulfilled .
the density profiles solutions in this approach present a novel core - halo morphology composed by a quantum degenerate core followed by a low degenerate plateau until they reach the @xmath0 boltzmannian regime ..
Please generate the next two sentences of the article | this interesting overall morphology provides the flat rotation curves in the outermost part of the galaxies as well as a possible alternative to massive black holes in their centers ( see @xcite and @xcite ) .
the system of einstein equations are written in a spherically symmetric space - time metric @xmath8 , where @xmath9 and @xmath10 depend only on the radial coordinate @xmath11 , together with the thermodynamic equilibrium conditions of tolman @xcite , and klein @xcite , @xmath12 where @xmath13 is the temperature , @xmath14 the chemical potential , @xmath1 the particle mass and @xmath15 the speed of light . |
3,237 | Suppose that you have an abstract for a scientific paper: abstractive summarization is an ideal form of summarization since it can synthesize information from multiple documents to create concise informative summaries . in this work
, we aim at developing an abstractive summarizer .
first , our proposed approach identifies the most important document in the multi - document set .
the sentences in the most important document are aligned to sentences in other documents to generate clusters of similar sentences .
second , we generate @xmath0-shortest paths from the sentences in each cluster using a word - graph structure . finally , we select sentences from the set of shortest paths generated from all the clusters employing a novel integer linear programming ( ilp ) model with the objective of maximizing information content and readability of the final summary .
our ilp model represents the shortest paths as binary variables and considers the length of the path , information score and linguistic quality score in the objective function .
experimental results on the duc 2004 and 2005 multi - document summarization datasets show that our proposed approach outperforms all the baselines and state - of - the - art extractive summarizers as measured by the rouge scores .
our method also outperforms a recent abstractive summarization technique . in manual evaluation ,
our approach also achieves promising results on informativeness and readability . .
And you have already written the first three sentences of the full article: abstractive summarization has gained popularity due to its ability of generating new sentences to convey the important information from text documents .
an abstractive summarizer should present the summarized information in a coherent form that is easily readable and grammatically correct .
readability or linguistic quality is an important indicator of the quality of a summary . several text - to - text ( t2 t ) generation techniques that aim to generate novel text from textual input.
Please generate the next two sentences of the article | have been developed @xcite . however , to the best of our knowledge , none of the above methods explicitly model the role of linguistic quality and only aim at maximizing information content of the summaries . in this work ,
we address readability by assigning a log probability score from a language model as an indicator of linguistic quality . more specifically |
3,238 | Suppose that you have an abstract for a scientific paper: the tight correlation of galactic velocity distribution to both luminosity and black hole mass , the relation of halo parameters to luminous mass distribution can not be due to collapse dynamics .
a baryonic big bang shell can solve galaxy formation problems by forming the supermassive black holes necessary to capture the initial blast wave in a coordinated pattern . .
And you have already written the first three sentences of the full article: although the @xmath0cdm model is quite successful on supragalactic scales@xcite , its predictions of galactic properties differ markedly with observation .
there has been an excellent fit to observations over 1 mpc by flat cosmological models with a mixture of baryons , dark matter and the cosmological constant .
however , on smaller scales on the order of galaxy and subgalactic , simulations have failed with the assumption that cold dark matter has weak self - interactions and weak baryonic interactions ..
Please generate the next two sentences of the article | cold dark matter should form triaxial halos with dense cores and other dense halo substructures . yet
it has been found that central regions on galactic scales have nearly spherical low density cores |
3,239 | Suppose that you have an abstract for a scientific paper: we uncover the basis for the validity of the tsallis statistics at the onset of chaos in logistic maps .
the dynamics within the critical attractor is found to consist of an infinite family of mori s @xmath0-phase transitions of rapidly decreasing strength , each associated to a discontinuity in feigenbaum s trajectory scaling function @xmath1 .
the value of @xmath0 at each transition corresponds to the same special value for the entropic index @xmath0 , such that the resultant sets of @xmath0-lyapunov coefficients are equal to the tsallis rates of entropy evolution . .
And you have already written the first three sentences of the full article: searches for evidence of nonextensive @xcite , @xcite properties at the period - doubling onset of chaos in logistic maps - the feigenbaum attractor - have at all times yielded affirmative responses , from the initial numerical studies @xcite , to subsequent heuristic investigations @xcite , and the more recent rigorous results robledo1 , @xcite . however a critical analysis and a genuine understanding of the basis for the validity at this attractor of the nonextensive generalization @xcite , @xcite of the boltzmann - gibbs ( bg ) statistical mechanics - here referred as @xmath0-statistics - is until now lacking . here
we clarify the circumstances under which the features of @xmath0-statistics are observed and , most importantly , we demonstrate that the mechanism by means of which the tsallis entropic index @xmath2 arises is provided by the occurrence of dynamical phase transitions of the kind described by the formalism of mori and colleagues @xcite .
these transitions , similar to first order thermal phase transitions , are associated to trajectories that link different regions within a multifractal attractor ..
Please generate the next two sentences of the article | the onset of chaos is an incipiently chaotic attractor , with memory preserving , nonmixing , phase space trajectories . because many of its properties are familiar , and well understood since many years ago
, it is of interest to explain how previous knowledge fits in with the new perspective . |
3,240 | Suppose that you have an abstract for a scientific paper: we are conducting a large program with the nrao very long baseline array ( vlba ) to measure trigonometric parallaxes of massive star - forming regions across the milky way . here
we report measurement of the parallax and proper motion of methanol masers in and .
the parallax of is @xmath0 mas ( @xmath1 kpc ) , placing it in the perseus spiral arm .
the parallax of is @xmath2 mas ( @xmath3 kpc ) , placing it between the carina - sagittarius and perseus arms , possibly in a local ( orion ) spur of the carina - sagittarius arm . for both sources , kinematic distances
are significantly greater than their parallax distances .
our parallaxes and proper motions yield full space motions accurate to @xmath4 .
both sources orbit the galaxy @xmath5 slower than circular rotation . .
And you have already written the first three sentences of the full article: an image of the milky way , taken by an observer in another galaxy would probably reveal a spiral structure dotted with many bright hii regions .
the milky way is believed to be spiral galaxy , and a best `` educated guess '' is that it is a barred sb to sc galaxy @xcite .
however , since we are inside the milky way , it has proved very difficult to properly characterize its structure @xcite ..
Please generate the next two sentences of the article | originally , studies of hi emission offered the opportunity to map the structure of the milky way @xcite .
hi emission on longitude - velocity plots clearly demonstrated that there were some coherent , large - scale structures , which were probably spiral arms in the milky way . |
3,241 | Suppose that you have an abstract for a scientific paper: this is an exposition of some basic ideas in the realm of global inverse function theorems .
we address ourselves mainly to readers who are interested in the applications to differential equations .
but we do not deal with those applications and we give a ` self - contained ' elementary exposition . the first part is devoted to the celebrated hadamard - caccioppoli theorem on proper local homeomorphisms treated in the framework of the hausdorff spaces . in the proof , the concept of ` @xmath0-limit set ' is used in a crucial way and this is perhaps the novelty of our approach . in the second part we deal with open sets in banach spaces .
the concept of ` attraction basin ' here is the main tool of our exposition which also shows a few recent results , here extended from finite dimensional to general banach spaces , together with the classical theorem of hadamard - levy which assumes that the operator norm of the inverse of the derivative does not grow too fast ( roughly at most linearly ) . .
And you have already written the first three sentences of the full article: a fundamental problem in analysis is the existence and/or uniqueness of the solutions to the equation @xmath1 in the unknown @xmath2 .
the function @xmath3 relates two spaces @xmath4 with some structure , otherwise we are impotent . from the other side , the concrete case where @xmath4 are subsets of the n - space @xmath5
is often too restrictive , and actually many applications arise in more general spaces ..
Please generate the next two sentences of the article | we especially think about injectivity and surjectivity problems in differential equations which are not discussed in this paper but constitute one of the reasons of our discussion .
the books prodi and ambrosetti [ 31 ] , and chow and hale [ 9 ] , give the proof of global inversion theorems in general spaces and show applications to differential equations . |
3,242 | Suppose that you have an abstract for a scientific paper: the einstein time dilation formula was tested in several experiments .
many trials have been made to measure the transverse second order doppler shift by mssbauer spectroscopy using a rotating absorber , to test the validity of this formula .
such experiments are also able to test if the time dilation depends only on the velocity of the absorber , as assumed by einstein s clock hypothesis , or the present centripetal acceleration contributes to the time dilation .
we show here that the fact that the experiment requires @xmath0-ray emission and detection slits of finite size , the absorption line is broadened ; by geometric longitudinal first order doppler shifts immensely . moreover , the absorption line is non - lorenzian .
we obtain an explicit expression for the absorption line for any angular velocity of the absorber . the analysis of the experimental results , in all previous experiments which did not observe the full absorption line itself , were wrong and the conclusions doubtful .
the only proper experiment was done by kndig ( phys .
rev . 129
( 1963 ) 2371 ) , who observed the broadening , but associated it to random vibrations of the absorber .
we establish necessary conditions for the successful measurement of a transverse second order doppler shift by mssbauer spectroscopy .
we indicate how the results of such an experiment can be used to verify the existence of a doppler shift due to acceleration and to test the validity of einstein s clock hypothesis . _
pacs _ : 76.80.+y , 03.30.+p _ keywords _ : mssbauer effect ; absorption line ; time dilation experiments ; transverse doppler shift ; einstein s clock hypothesis .
And you have already written the first three sentences of the full article: after the discovery of the mssbauer effect in 1958 , quantitative measurements of relativistic time dilation were carried out in the 1960s based on this effect @xcite-@xcite , and the interest in such measurements lasts to this day @xcite,@xcite . the experiments @xcite-@xcite reported full agreement with the time dilation predicted by einstein s theory of relativity . in the experiments @xcite-@xcite ,
the mssbauer source was placed at the center of a fast rotating disk and an absorber at the rim of the disk . in the analyses of these experiments ,
it was assumed that the absorption line of the rotating absorber stays lorentzian with same width as at rest , and is shifted only by the time dilation factor ..
Please generate the next two sentences of the article | based on the generalized principle of relativity and the ensuing symmetry , in @xcite it was shown that there are only two possible types of transformations between uniformly accelerated systems . the validity of the _ clock hypothesis _ is crucial to determining which one of the two types of transformations is obtained .
the clock hypothesis , as stated in @xcite , maintains that the rate of an accelerated clock is equal to that of a co - moving unaccelerated clock . |
3,243 | Suppose that you have an abstract for a scientific paper: motivated by future collider proposals that aim to measure the higgs properties precisely , we study the partial decay widths of the lightest higgs boson in the minimal supersymmetric standard model with an emphasis on the parameter region where all superparticles and heavy higgs bosons are not accessible at the lhc . taking account of phenomenological constraints such as the higgs mass , flavor constraints , vacuum stability , and perturbativity of coupling constants up to the grand unification scale ,
we discuss how large the deviations of the partial decay widths from the standard model predictions can be .
these constraints exclude large fraction of the parameter region where the higgs widths show significant deviation from the standard model predictions
. nevertheless , even if superparticles and the heavy higgses are out of the reach of @xmath0 lhc , the deviation may be large enough to be observed at future @xmath1 collider experiments .
ut-15 - 02 + ipmu-15 - 0018 + kek - th-1795 + february , 2015 + .75 in * footprints of supersymmetry on higgs decay * .75 in motoi endo@xmath2 , takeo moroi@xmath2 , and mihoko m. nojiri@xmath3 0.25 in @xmath4 _ department of physics , university of tokyo , tokyo 113 - 0033 , japan _ 0.1 in @xmath5 _ kavli ipmu ( wpi ) , university of tokyo , kashiwa , chiba 277 - 8583 , japan _ 0.1 in @xmath6
_ kek theory center , ipns , kek , tsukuba , ibaraki 305 - 0801 , japan _ 0.1 in @xmath7 _ the graduate university of advanced studies ( sokendai ) , + tsukuba , ibaraki 305 - 0801 , japan
_ .5 in .
And you have already written the first three sentences of the full article: the discovery of the higgs boson at atlas and cms experiments @xcite made a revolutionary impact on the field of particle physics .
it not only confirmed the so - called higgs mechanism for the electroweak symmetry breaking , but also opened a new possibility to perform a precise test of the standard model ( sm ) by studying the properties of the higgs boson . in the sm ,
the coupling constants of the higgs boson with other particles are well understood using the fact that the masses of quarks , leptons , and weak bosons originate in the vacuum expectation value ( vev ) of the higgs field , resulting in the prediction of the partial decay widths of the higgs boson into various particles . in models with physics beyond the sm ( bsm ) ,.
Please generate the next two sentences of the article | measurements of the higgs couplings provide even exciting possibilities . in large class of bsm models
, there exist new particles at the electroweak to tev scale , which affect the properties of the higgs boson . |
3,244 | Suppose that you have an abstract for a scientific paper: in a recent paper published in this journal , zhao and collaborators [ phys .
rev .
d * 82 * , 084030 ( 2010 ) ] analyze a toy model of thick branes generated by a real scalar field with the potential @xmath0 , and investigate the variation of the mass parameter @xmath1 on the branes as well as the localization and resonances of fermions . in that research
the simplest yukawa coupling @xmath2 was considered . in that work
does not analyze the zero mode in details and also contains some misconceptions . in this paper ,
the effect of the variation of the mass parameter @xmath1 on the brane is reinvestigated and it is associated to the phenomenon of brane splitting .
furthermore , it is shown that the zero mode for the left - handed fermions can be localized on the brane depending on the values for the coupling constant @xmath3 and the mass parameter @xmath1 . .
And you have already written the first three sentences of the full article: the authors of ref . @xcite investigated the effects of the variation of the mass parameter @xmath1 on the thick branes .
they used a real scalar field , which has a potential of the @xmath4 model , as the background field of the thick branes .
it was found that the number of the bound states ( in the case without gravity ) or the resonant states ( in the case with gravity ) increases with the parameter @xmath1 ..
Please generate the next two sentences of the article | that work considered the simplest yukawa coupling @xmath2 , where @xmath3 is the coupling constant .
the authors stated that as the value of @xmath1 is increasing , the maximum of the matter energy density splits into two new maxima , and the distance of the new maxima increases and the brane gets thicker . |
3,245 | Suppose that you have an abstract for a scientific paper: the electromagnetic two - body problem has _
neutral differential delay _ equations of motion that , for generic boundary data , can have solutions with _ discontinuous _ derivatives . if one wants to use these neutral differential delay equations with _ arbitrary _ boundary data , solutions with discontinuous derivatives must be expected and allowed .
surprisingly , wheeler - feynman electrodynamics has a boundary value variational method for which minimizer trajectories with discontinuous derivatives are also expected , as we show here .
the variational method defines continuous trajectories with piecewise defined velocities and accelerations , and electromagnetic fields defined _ by _ the euler - lagrange equations _ on _ trajectory points .
here we use the piecewise defined minimizers with the linard - wierchert formulas to define generalized electromagnetic fields almost everywhere ( but on sets of points of zero measure where the advanced / retarded velocities and/or accelerations are discontinuous ) . along with this generalization
we formulate the _ generalized absorber hypothesis _ that the far fields vanish asymptotically _ almost everywhere _ and show that localized orbits with far fields vanishing almost everywhere _ must _ have discontinuous velocities on sewing chains of breaking points .
we give the general solution for localized orbits with vanishing far fields by solving a ( linear ) neutral differential delay equation for these far fields .
we discuss the physics of orbits with discontinuous derivatives stressing the differences to the variational methods of classical mechanics and the existence of a spinorial four - current associated with the generalized variational electrodynamics . .
And you have already written the first three sentences of the full article: non - radiating motion of extended charge distributions in classical electrodynamics has been known to exist for some time ( c.f . @xcite and references therein , and @xcite ) . on the other hand , for systems with a few _ point charges _ , larmor s radiation of energy at a rate proportional to the squared modulus of the acceleration plagues classical electrodynamics . to construct orbits that do not radiate , and hence are without acceleration ,
a simple option are constant velocity motions , which imply unbounded motion .
along _ bounded _ two body motions supported by mutual action at a distance , we expect acceleration to be needed to change velocities , unless velocities are allowed to change discontinuously ..
Please generate the next two sentences of the article | for example , periodic polygonal orbits with piecewise constant velocity segments have vanishing radiation fields .
here we extend wheeler - feynman electrodynamics @xcite to include motion with discontinuous velocities . |
3,246 | Suppose that you have an abstract for a scientific paper: a reliable evaluation of the integral giving the hadronic vacuum polarization contribution to the muon anomalous magnetic moment should be possible using a simple trapezoid - rule integration of lattice data for the subtracted electromagnetic current polarization function in the euclidean momentum interval @xmath0 , coupled with an @xmath1-parameter pad or other representation of the polarization in the interval @xmath2 , for sufficiently high @xmath3 and sufficiently large @xmath1 . using a physically motivated model for the @xmath4 polarization , and the covariance matrix from a recent lattice simulation to generate associated fake `` lattice data , ''
we show that systematic errors associated with the choices of @xmath3 and @xmath1 can be reduced to well below the @xmath5 level for @xmath3 as low as @xmath6 gev@xmath7 and rather small @xmath1 .
for such low @xmath3 , both an nnlo chiral representation with one additional nnnlo term and a low - order polynomial expansion employing a conformally transformed variable also provide representations sufficiently accurate to reach this precision for the low-@xmath8 contribution .
combined with standard techniques for reducing other sources of error on the lattice determination , this hybrid strategy thus looks to provide a promising approach to reaching the goal of a sub - percent precision determination of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment on the lattice . .
And you have already written the first three sentences of the full article: the discrepancy of about @xmath9 between the measured value @xcite and standard model prediction @xcite for the anomalous magnetic moment of the muon , @xmath10 , has attracted considerable attention . after the purely qed contributions , which are now known to five loops @xcite , the next most important term in the standard model prediction is the leading order ( lo ) hadronic vacuum polarization ( hvp ) contribution , @xmath11 .
the error on the dispersive evaluation of this quantity , obtained from the errors on the input @xmath12 cross - sections , is currently the largest of the contributions to the error on the standard model prediction @xcite .
the dispersive approach is , moreover , complicated by discrepancies between the determinations by different experiments of the cross - sections for the most important exclusive channel , @xmath13 @xcite ..
Please generate the next two sentences of the article | the existence of this discrepancy , and the role played by the error on the lo hvp contribution , have led to an increased interest in providing an independent determination of @xmath11 from the lattice @xcite .
such a determination is made possible by the representation of @xmath11 as a weighted integral of the subtracted polarization , @xmath14 , over euclidean momentum - squared @xmath8 @xcite . |
3,247 | Suppose that you have an abstract for a scientific paper: we propose to study possible signals of just - so oscillations in new - generation solar neutrino experiments by separating the events detected when the earth is nearest to the sun ( perihelion @xmath0 3 months ) from those detected when the earth is farthest from the sun ( aphelion @xmath0 3 months ) .
we introduce a solar model independent near - far asymmetry , which is non - zero if just - so oscillations occur .
we apply our calculations to the kinetic energy spectra of electrons induced by @xmath1b solar neutrino interactions in the superkamiokande and sudbury neutrino observatory experiments .
we show that the sensitivity to the neutrino oscillation parameters can be increased by probing the near - far asymmetry in selected parts of the electron energy spectra . .
And you have already written the first three sentences of the full article: neutrino flavor oscillations in vacuum @xcite represent a viable solution @xcite to the observed deficit of the solar neutrino flux @xcite as compared to the predictions of the standard solar model @xcite .
if the oscillations have a wavelength comparable to the earth orbit radius ( just - so oscillations @xcite ) , then significant distortions could arise both in the neutrino energy spectrum @xcite ( as a result of the energy - dependence of the oscillation probability ) and in the time structure of the signal @xcite ( as a result of the earth s orbit eccentricity @xcite ) .
the combination of these two effects , namely time - dependent spectral distortions , could also be observable @xcite ..
Please generate the next two sentences of the article | the four pioneering solar neutrino experiments have not observed such effects .
the three radiochemical experiments @xcite can not observe _ a priori _ spectral distortions since they detect only energy - integrated signals @xcite , and do not show evidence for periodic variations of the detected rates associable to just - so oscillations ( see , e.g. , @xcite ) . the neutrino - electron scattering experiment kamiokande @xcite shows no evidence for distortions in the spectrum of the scattered electrons @xcite either . however , these are low - statistics experiments , and possible vacuum oscillation effects could be hidden by the relatively large uncertainties . much higher statistics ( thousands of events per year ) will be collected with the second - generation experiments superkamiokande @xcite and sudbury neutrino observatory ( sno ) @xcite . |
3,248 | Suppose that you have an abstract for a scientific paper: we demonstrate the applicability of four - body exponentially correlated functions for the accurate calculations of relativistic effects in lithium - like atoms and present results for matrix elements of various operators which involve negative powers of interparticle distances . .
And you have already written the first three sentences of the full article: in the accurate evaluation of atomic energy levels not only the nonrelativistic energy , but also relativistic and qed effects have to be calculated with the high precision .
the only approach which consistently accounts for all corrections in small atomic systems is the one based on the expansion of the energy in the fine structure constant @xmath0 @xmath1.\ ] ] each term in this expansion can be expressed as the expectation value of some effective hamiltonian with the nonrelativistic wave function .
namely @xmath2 is the nonrelativistic energy ( in atomic units ) , @xmath3 is the relativistic correction , which for states with the vanishing angular momentum is the expectation value of @xmath4 in eq ..
Please generate the next two sentences of the article | ( [ df_h4 ] ) .
@xmath5 and higher order corrections are expressed in terms of matrix elements of some more complicated operators . |
3,249 | Suppose that you have an abstract for a scientific paper: baryonic oscillations in the galaxy power spectrum have been studied as a way of probing dark - energy models .
while most studies have focused on spectroscopic surveys at high redshift , large multi - color imaging surveys have already been planned for the near future . in view of this , we study the prospects for measuring baryonic oscillations from angular statistics of galaxies binned using photometric redshifts .
we use the galaxy bispectrum in addition to the power spectrum ; this allows us to measure and marginalize over possibly complex galaxy bias mechanisms to get robust cosmological constraints . in our parameter estimation
we allow for a weakly nonlinear biasing scheme that may evolve with redshift by two bias parameters in each of ten redshift bins .
we find that a multi - color imaging survey that probes redshifts beyond one can give interesting constraints on dark - energy parameters .
in addition , the shape of the primordial power spectrum can be measured to better accuracy than with the cmb alone .
we explore the impact of survey depth , area , and calibration errors in the photometric redshifts on dark - energy constraints .
[ firstpage ] cosmological parameters distance scale equation of state large - scale structure of universe .
And you have already written the first three sentences of the full article: recent cosmological observations have provided strong evidence that a dark - energy component , such as the cosmological constant , comprises as much as 70 per cent of the total energy density of the universe ( @xcite ) . characterizing the nature of the dark energy and its possible
evolution has become a central goal of empirical work in cosmology .
galaxy surveys measure the clustering statistics of galaxies as a function of scale and redshift ..
Please generate the next two sentences of the article | the galaxy power spectrum can be compared to the cmb power spectrum to constrain the growth of structure .
however the amplitude of the galaxy power spectrum depends on the biasing of the particular galaxy sample ; one therefore needs to exercise care in using the full power spectrum for cosmological inferences ( e.g. @xcite ) . |
3,250 | Suppose that you have an abstract for a scientific paper: the solar system started to form about 4.56 gyr ago and despite the long intervening time span , there still exist several clues about its formation .
the three major sources for this information are meteorites , the present solar system structure and the planet - forming systems around young stars . in this introduction
we give an overview of the current understanding of the solar system formation from all these different research fields .
this includes the question of the lifetime of the solar protoplanetary disc , the different stages of planet formation , their duration , and their relative importance .
we consider whether meteorite evidence and observations of protoplanetary discs point in the same direction .
this will tell us whether our solar system had a typical formation history or an exceptional one .
there are also many indications that the solar system formed as part of a star cluster . here
we examine the types of cluster the sun could have formed in , especially whether its stellar density was at any stage high enough to influence the properties of today s solar system .
the likelihood of identifying siblings of the sun is discussed .
finally , the possible dynamical evolution of the solar system since its formation and its future are considered .
november 2014 .
And you have already written the first three sentences of the full article: for decades the solar system was assumed to be the prototype for planetary system formation . with the detection of over a thousand confirmed exoplanets and many more candidates , it has become apparent that many planetary systems exist that differ substantially in their structural properties from our solar system .
nevertheless the formation of the solar system is still of special interest for several reasons .
first , it is only for the solar system that we can directly examine material that is left over from the formation process in the form of meteorites ..
Please generate the next two sentences of the article | second , only for the solar system do we have detailed structural information about the entire system including its smaller bodies .
last but not least , it is only for the solar system that we know for sure that life exists . |
3,251 | Suppose that you have an abstract for a scientific paper: we demonstrate _ in situ _ fluorescence detection of @xmath0li atoms in a 1d optical lattice with single atom precision . even though illuminated lithium atoms tend to boil out , when the lattice is deep , molasses beams without extra cooling retain the atoms while producing sufficient fluorescent photons for detection .
when the depth of the potential well at an antinode is 2.4 mk , an atom remains trapped for 30 s while scattering probe photons at the rate of @xmath1 s@xmath2 .
we propose a simple model that describes the dependence of the lifetime of an atom on well depth .
when the number of trapped atoms is reduced , a clear stepwise change is observed in integrated fluorescence , indicating the detection of a single atom . at a photon - collecting efficiency of only 1.3% owing to small numerical aperture , the presence or absence of an atom
is determined within 300 ms with an error of less than @xmath3 . .
And you have already written the first three sentences of the full article: as both internal and motional states of trapped atoms are controlled more and more precisely for their quantum manipulation , it has also become very important to observe those atoms _ in situ _ and individually .
efforts to image fluorescence from single trapped atoms started with those in a magneto - optical trap ( mot ) @xcite .
it was extended to single atoms in a 1d optical lattice with a site - specific resolution using a diffraction - limited imaging system and careful offline analysis @xcite ..
Please generate the next two sentences of the article | these efforts culminated when the individual sites of a 2d optical lattice were imaged using objective lenses with high numerical aperture ( na ) @xcite .
the 2d version is known as a quantum - gas microscope , and it was developed primarily to prepare samples for and read out results from quantum simulation of interacting particles . |
3,252 | Suppose that you have an abstract for a scientific paper: we present a detailed comparison between far - uv / optical colour magnitude diagrams obtained with high - resolution _
hubble space telescope _ data and suitable theoretical models for three galactic globular clusters : m3 , m13 and m79 .
+ these systems represents a `` classical '' example of clusters in the intermediate metallicity regime that , even sharing similar metal content and age , show remarkably different horizontal branch morphologies . as a consequence
, the observed differences in the colour distributions of horizontal branch stars can not be interpreted in terms of either first ( metallicity ) or a second parameter such as age .
+ we investigate here the possible role of variations of initial helium abundance ( @xmath0 ) .
thanks to the use of a proper setup of far - uv filters , we are able to put strong constraints on the maximum y ( @xmath1 ) values compatible with the data .
we find differences @xmath2 between the clusters with m13 showing the largest value ( @xmath3 ) and m3 the smallest ( @xmath4 ) .
in general we observe that these values are correlated with the colour extensions of their horizontal branches and with the range of the observed na - o anti - correlations .
[ firstpage ] globular clusters : individual ( m3 , m13 , m79 ) ; stars : evolution horizontal branch ; ultraviolet : stars .
And you have already written the first three sentences of the full article: horizontal branch ( hb ) stars are the progeny of low - mass red giant branch stars ( rgb ) burning helium in their cores and hydrogen in a shell around it ( hoyle & schwarzschild 1955 ) .
as first noticed by iben & rood ( 1970 ) , the different hb star colour distributions observed in old stellar systems , is the reflection of the amount of mass lost during the rgb phase .
+ the scientific community agrees from nearly fifty years about the fact that the principal parameter governing the shape of hbs in galactic globular clusters ( ggcs ) is metallicity ..
Please generate the next two sentences of the article | the general rule is that metal - rich systems have red hbs , while in the metal - poor ones stars are distributed on average at higher effective temperatures ( bluer colours ) .
several exceptions have come out during the last decades ; remarkable cases the cases of ngc6388 and ngc6441 ( rich et al . |
3,253 | Suppose that you have an abstract for a scientific paper: a variety of strong and electroweak interaction properties of the pion and the light scalar @xmath0 meson are computed in a relativistic quark model . under the assumption that the resulting coupling of these mesons to the constituent quarks is identical ,
the @xmath0 meson mass is determined as @xmath1 mev .
we discuss in detail the gauging of the non - local meson - quark interaction and calculate the electromagnetic form factor of the pion and the form factors of the @xmath2 and @xmath3 processes .
we obtain explicit expressions for the relevant form factors and evaluate the leading and next - to - leading orders for large euclidean photon virtualities . turning to the decay properties of the @xmath0 we determine the width of the electromagnetic @xmath3 transition and discuss the strong decay @xmath4 . in a final step
we compute the nonleptonic decays @xmath5 and @xmath6 relevant for the possible observation of the @xmath7 meson .
all our results are compared to available experimental data and to results of other theoretical studies .
.5 cm .5 cm _ pacs : _
12.39.ki , 13.25.ft , 13.40.gp , 13.40.hq , 14.40.lb .5 cm _ keywords : _ @xmath8 and @xmath0 meson ; @xmath9 and @xmath10 meson ; relativistic quark model ; nonleptonic and electromagnetic decays . .
And you have already written the first three sentences of the full article: during the last few years the physics of isoscalar scalar mesons and in particular of the @xmath0 meson has received an revival of interest due to substantial progress in experimental and theoretical activities @xcite ( for a status report see , for example , ref .
originally , the light scalar meson @xmath0 was introduced as the chiral partner of the pion in the two - flavor linear @xmath0-model @xcite .
the linear @xmath0-model fulfils the chiral commutation relations , contains the partial conservation of the axial current ( pcac ) and has a manifestly renormalizable lagrangian . in approaches based on the linear realization of chiral symmetry ( see , for example , @xcite ).
Please generate the next two sentences of the article | the @xmath0 meson serves to create spontaneous breaking of chiral symmetry , it generates the constituent quark mass and it is a relevant ingredient in explaining low - energy phenomenology ( @xmath11 scattering , @xmath12 enhancement in @xmath13 , attractive interaction between baryons in nuclear matter , etc . ) . on the other hand , the use of the linear or non - derivative @xmath0-model lagrangian leads to well - known difficulties .
for example , current - algebra results can not be reproduced at the tree level and can only be generated by mixing up different orders in the chiral expansion . |
3,254 | Suppose that you have an abstract for a scientific paper: long - range contributions to the three - nucleon force that have been recently worked out in chiral effective field theory at next - to - next - to - next - to - leading order are for the first time included in the triton and the doublet nucleon - deuteron scattering length calculations .
the strengths of the two short - range terms available at this order in the chiral expansion are determined from the triton binding energy and the neutron - deuteron doublet scattering length .
the structure of the resulting three - nucleon force is explored and effects for the two - nucleon correlation function in the triton are investigated .
expectation values of the individual contributions to the three - nucleon force in the triton are found to be in the range from a few @xmath0 kev to about @xmath1 mev .
our study demonstrates that the very complicated operator structure of the novel chiral three - nucleon forces can be successively implemented in three - nucleon faddeev calculations . .
And you have already written the first three sentences of the full article: chiral effective field theory ( eft ) provides a powerful framework to systematically describe low - energy dynamics of few- and many - nucleon systems .
various variants of effective theories for nuclear forces have been explored , see @xcite for recent review articles . up to now
, the most advanced few - nucleon studies have been carried out within a framework based on pions and nucleons as the only explicit degrees of freedom taken into account in the effective lagrangian . within this approach , the nucleon - nucleon ( nn ) force is currently available up to next - to - next - to - next - to leading order ( n@xmath2lo ) in the chiral expansion . at this chiral order.
Please generate the next two sentences of the article | , it receives contributions from one- , two- and three - pion exchange diagrams as well as short - range nn contact interactions with up to four derivatives . as demonstrated in refs .
@xcite , nn phase shifts are accurately described at n@xmath2lo up to laboratory energies of the order of 200 mev . |
3,255 | Suppose that you have an abstract for a scientific paper: we investigate the contribution of the beamed jet component to the high energy emission in young and compact extragalactic radio sources , focusing for the first time on the @xmath0-ray band .
we derive predictions on the @xmath0-ray luminosities associated with the relativistic jet assuming a leptonic radiative model .
the high energy emission is produced via compton scattering by the relativistic electrons in a spherical region at the considered scales ( @xmath110 kpc ) .
simulations show a wide range of @xmath0-ray luminosities , with intensities up to @xmath2 erg s@xmath3 depending on the assumed jet parameters . we find a highly linear relation between the simulated x - ray and @xmath0-ray luminosities that can be used to select candidates for a @xmath0-ray detection .
we compare the simulated luminosity distributions in the radio , x - ray and @xmath0-ray regimes with observations for the largest sample of x - ray detected young radio quasars .
our analysis of @xmath44-year _ fermi _ large area telescope ( lat ) data does not give any statistically significant detection .
however , the majority of the model - predicted @xmath0-ray fluxes for the sample are near or below the current _ fermi_-lat flux threshold and compatible with the derived upper limits .
our study gives constraints on the minimum jet power ( @xmath5 ) , on a potential jet contribution to the x - ray emission in the most compact sources ( @xmath6 kpc ) and on the particles to magnetic field energy density ratio in broad agreement with equipartition assumption . .
And you have already written the first three sentences of the full article: young and compact radio sources represent the first stage in the evolution of large extragalactic radio sources and constitute an important fraction ( @xmath7 ) of the radio source population ( see , however , * ? ? ?
* ; * ? ? ?
* for problems in selecting genuine young sources against blazars ) ..
Please generate the next two sentences of the article | there are still open questions on the radio source initial phase , concerning its impact on the host galaxy and the evolutionary path from compact to large ( and giant ) radio structures .
+ simulations indicate that during the first phase of the expansion ( which lasts @xmath810@xmath9 yrs ) a powerful radio source can interact with the interstellar medium ( ism ) of its host galaxy , and later on with the intergalactic medium ( igm ) ( * ? ? ? |
3,256 | Suppose that you have an abstract for a scientific paper: we explore the connection between black hole spin and agn power by addressing the consequences underlying the assumption in the recent literature that the gap region between accretion disks and black holes is fundamental in producing strong , spin - dependent , horizon - threading magnetic fields . under the additional assumption that jets and outflows in agn are produced by the blandford - znajek and blandford - payne mechanisms ,
we show that maximum jet / outflow power is achieved for accretion onto black holes having highly retrograde spin parameter , an energetically excited yet unstable gravitomagnetic configuration . .
And you have already written the first three sentences of the full article: the paradigm that has emerged for the production of outflows from active galactic nuclei ( agn ) involves the presence of large scale electromagnetic fields which are instrumental in their formation , acceleration and collimation , many gravitational radii from the central supermassive black hole ( nakamura et al , 2008 ; meier et al , 2001 ; blandford , 1976 ; lovelace , 1976 ) .
two models have taken center stage .
blandford & payne ( 1982 ; henceforth bp ) and extensions of this model ( li et al , 1992 and vlahakis & konigl , 2003 ) describe a centrifugally driven outflow of gas originating in a cold accretion disk as a solution to ideal mhd within the context of self - similarity ..
Please generate the next two sentences of the article | if the angle between the poloidal component of the magnetic field and the disk surface is less than 60 degrees , mass - loading of the magnetic field lines occurs , leading to an inbalance between inward gravitational and outward centrifugal forces , with gravity being overwhelmed . unlike the bp mechanism which taps into the gravitational potential energy of the accretion flow , the blandford - znajek ( 1977 ; henceforth bz ) mechanism produces relativistic jets from large scale magnetic fields threading the rotating event horizon by extraction of black hole rotational energy .
the flux - trapping model ( reynolds et al , 2006 ) is an attempt to understand ways in which black hole accretion flows can overcome their diffusive character ( see also bisnovatyi - kogan & lovelace , 2007 and rothstein & lovelace , 2008 ) to produce strong magnetic field on the black hole ( see bisnovatyi - kogan & ruzmaikin , 1976 , for earliest attempt to study the accretion of large - scale ordered magnetic field on black hole ) indicating that if the flux - trapping behavior of the gap / plunge region is valid , the bz mechanism produces greatest power for black hole spin of @xmath0 ( garofalo , 2009 ) . here |
3,257 | Suppose that you have an abstract for a scientific paper: we study the interaction of graphene with ultrashort few femtosecond long optical pulse .
for such a short pulse , the electron dynamics is coherent and is described within the tight - binding model of graphene .
the interaction of optical pulse with graphene is determined by strong wave vector dependence of the interband dipole matrix elements , which are singular at the dirac points of graphene .
the electron dynamics in optical pulse is highly irreversible with large residual population of the conduction band .
the residual conduction band population as a function of the wave vector is nonuniform with a few localized spots of high conduction band population .
the spots are located near the dirac points and the number of spots depends on the pulse intensity .
the optical pulse propagating through graphene layer generates finite transferred charge , which , as a function of pulse intensity , changes its sign . at small pulse intensity
, the charge is transferred in the direction of the pulse maximum , while at large pulse intensity , the direction of the charge transfer is opposite to the direction of pulse maximum .
this property opens unique possibility of controlling the direction of the charge transfer by variation of the pulse intensity .
= 1.5truecm .
And you have already written the first three sentences of the full article: interaction of ultrashort and strong optical laser pulse with solids has been a subject of intensive theoretical and experimental research during the last few decades .
@xcite the interest in this field has grown after experimental realization of short laser pulses with just a few oscillations of optical field , which is comparable to the internal fields of a solid.@xcite such high intensity optical pulses strongly affect the electron dynamics and strongly modify the transport and optical properties of solids within the duration of the pulse,@xcite which is a few femtosecond - long .
the response of electron system of a solid to the optical field of the pulse strongly depends on the band structure of the solid . for dielectrics , the main energy parameter , which determines the interaction of a solid with the laser pulse , is the bandgap @xmath0 between the occupied valence band and the empty conduction band ..
Please generate the next two sentences of the article | if the pulse frequency is small , @xmath1 , then the electron dynamics can be described in terms of the dynamics of the passage through anticrossing points of quasistationary wannier - stark levels of conduction and valence bands in time dependent electric field of the laser pulse.@xcite the passage through such anticrossing points determines whether the electron dynamics is adiabatic or diabatic .
the last anticrossing point corresponds to the electric field of the strength @xmath2 . |
3,258 | Suppose that you have an abstract for a scientific paper: it has been argued that the solar magnetic cycle consists of two main periodic components : a low - frequency component ( hale s 22-year cycle ) and a high - frequency component ( quasi - biennial cycle ) .
the existence of the double magnetic cycle on the sun is confirmed using stanford , mount wilson and kitt peak magnetograph data from 1976 to 1996 ( solar cycles 21 and 22 ) . in the frame of the parker s dynamo theory a model of the double magnetic cycle is presented .
this model is based on the idea of two dynamo sources separated in space .
the first source of the dynamo action is located near the bottom of the convection zone , and the second operates near the top .
the model is formulated in terms of two coupled systems of non - linear differential equations .
it is demonstrated that in the case of weak interaction between the two dynamo sources the basic features of the double magnetic cycle such as existence of two component and observed temporal variations of high - frequency component can be reproduced .
# 1#2 .
And you have already written the first three sentences of the full article: the 22-yr cycle of solar activity is a magnetic cycle which consists of two 11-years sunspot cycles .
the 22-yr cycles begin on even sunspot cycles according to the zrich numbering ( @xcite ) and manifest themselves in reversal of polarity of sunspots ( hale s law ) . from one 11-yr cycle to another
, the polarity of the preceding ( @xmath0 ) and following ( @xmath1 ) sunspots reverses ..
Please generate the next two sentences of the article | this reversal corresponds to the changing of the toroidal magnetic field ( @xmath2-component ) . during even - numbered cycles @xmath3 ( the direction of the magnetic vector coincides with the direction of solar rotation ) in the northern ( @xmath4 ) hemisphere and @xmath5 in the southern ( @xmath6 ) hemisphere
this relation is reversed during odd - numbered cycles . in parallel with this , the poloidal magnetic field , or background field ( @xmath7-component ) , shows a 22-yr periodicity ( @xcite ) , and other studies ( @xcite ) have suggested that the low - latitude and polar fields similarly show a 22-yr periodicity . |
3,259 | Suppose that you have an abstract for a scientific paper: we study the geometry of the critical clusters in fully coordinated percolation on the square lattice . by monte carlo simulations ( static exponents ) and
normal mode analysis ( dynamic exponents ) , we find that this problem is in the same universality class with ordinary percolation _ statically _ but not so _ dynamically_.
we show that there are large differences in the number and distribution of the _ interior _ sites between the two problems which may account for the different dynamic nature . .
And you have already written the first three sentences of the full article: the geometrical phase transition known as percolation ( see , for a review , stauffer and aharony @xcite ) is appreciated by many to be an elegant and simply defined yet fully featured example of a second order phase transition .
a number of variations of the original percolation problem were proposed as better models of some physical phenomena in the past .
this includes the _ backbone _ percolation for studying electrical conduction through random media , _ polychromatic _ percolation for multi - component composites , and _ four - coordinated _ bond percolation for hydrogen - bonded water molecules . in particular , blumberg et al @xcite and gonzalez and reynolds @xcite studied a random bond , site - correlated percolation problem they call four - coordinated percolation on the square lattice ..
Please generate the next two sentences of the article | they conclude that this problem belongs to the same universality class as the ordinary random percolation with the same set of ( static ) exponents . in this paper
, we revisit a problem in this realm , though not exactly the same one . |
3,260 | Suppose that you have an abstract for a scientific paper: quantum frequency conversion ( qfc ) in nonlinear optical media is a powerful tool for temporal - mode selective manipulation of light .
recent attempts at achieving high mode selectivities and/or fidelities have had to resort to multi - dimensional optimization schemes to determine the system s natural schmidt modes .
certain combinations of relative - group velocities between the relevant frequency bands , medium length , and temporal pulse widths have been known to achieve good selectivities ( exceeding @xmath0% ) for temporal modes that are nearly identical to pump pulse shapes , even for high conversion efficiencies . working in this parameter regime using an off - the - shelf , second - harmonic generation , mgo : ppln waveguide , and with pulses on the order of @xmath1 fs at wavelengths around @xmath2 nm
, we verify experimentally that model - predicted schmidt modes provide the high temporal - mode selectivity expected .
this paves the way to the implementation of a proposed two - stage qfc scheme that is predicted to reach near - perfect ( @xmath3% ) selectivity .
10 b. j. smith and m. g. raymer , `` photon wave functions , wave - packet quantization of light , and coherence theory , '' new journal of physics * 9 * , 414 ( 2007 ) . m. g. raymer and k. srinivasan , `` manipulating the color and shape of single photons , '' physics today * 65 * , 32 ( 2012 ) .
j. roslund , r. m. de araujo , s. jiang , c. fabre , and n. treps , `` wavelength - multiplexed quantum networks with ultrafast frequency combs , '' nat .
photonics * 8 * , 109 ( 2014 ) .
v. a. averchenko , v. thiel , and n. treps , `` nonlinear photon subtraction from a multimode quantum field , '' phys .
rev . a * 89 * , 063808 ( 2014 ) .
b. brecht , d. v. reddy , c. silberhorn , and m. g. raymer , `` photon temporal modes : a complete framework for quantum information science , '' phys .
rev .
x * 5 * , 041017 ( 2015 ) .
m. pant and d. englund , `` high - dimensional unitary....
And you have already written the first three sentences of the full article: temporal modes of light @xcite are a burgeoning new subspace for both classical and quantum information encoding @xcite .
the temporal mode ( tm ) bases are discrete and in principle infinite dimensional , and truly orthogonal .
these orthogonal modes have overlapping spectra at the same carrier frequency , fully overlap in time , and share the same polarization and transverse spatial mode properties , making them convenient for long - distance communication and interfacing with optical memories @xcite ..
Please generate the next two sentences of the article | co - propagating tms maintain relative coherence across the entire mode space , and experience the same reversible unitary dispersion during propagation in typical media . in order to fully exploit tms as a resource ,
we need highly tm - selective , high - fidelity devices that can generate , sort , store , measure , and generally manipulate them , even at the single - photon level @xcite . |
3,261 | Suppose that you have an abstract for a scientific paper: for an understanding of a heat engine working in the microscopic scale , it is often necessary to estimate the amount of reversible work extracted by isothermal expansion of the quantum gas used as its working substance .
we consider an engine with a movable wall , modeled as an infinite square well with a delta peak inside . by solving the resulting one - dimensional schrdinger equation
, we obtain the energy levels and the thermodynamic potentials .
our result shows how quantum tunneling degrades the engine by decreasing the amount of reversible work during the isothermal expansion . .
And you have already written the first three sentences of the full article: a fundamental idea behind classical statistical mechanics is that we are living in a macroscopic world , which means that we are unable to deal with microstates on a molecular level .
this forces us to distinguish heat from work and to accept the increase of entropy on probabilistic ground , when we formulate the laws of thermodynamics .
however , the border between our macroscopic world and the microscopic world of molecules is becoming vague due to technological developments over the last century ..
Please generate the next two sentences of the article | this has led to a natural question ; i.e. , what would it mean to thermodynamics if it became possible to access and manipulate microstates just as we do macrostates ?
the founders of statistical mechanics were already aware of this problem : for example , maxwell imagined an intelligent being s intervention on a molecular level in his famous thought experiment , now known as maxwell s demon @xcite , and expressed deep concern about the foundation of the second law of thermodynamics . |
3,262 | Suppose that you have an abstract for a scientific paper: we study quantum quench in a holographic model of a zero temperature insulator - superfluid transition .
the model is a modification of that of arxiv:0911.0962 and involves a self - coupled complex scalar field , einstein gravity with a negative cosmological constant , and maxwell field with one of the spatial directions compact . in a suitable regime of parameters ,
the scalar field can be treated as a probe field whose backreaction to both the metric and the gauge field can be ignored .
we show that when the chemical potential of the dual field theory lies between two critical values , the equilibrium background geometry is a ads soliton with a constant gauge field , while the complex scalar condenses leading to broken symmetry .
we then turn on a time dependent source for the order parameter which interpolates between constant values and crosses the order - disorder critical point . in the critical region adiabaticity
breaks down , but for a small rate of change of the source @xmath0 there is a new small-@xmath0 expansion in fractional powers of @xmath0 .
the resulting critical dynamics is dominated by a zero mode of the bulk field .
to lowest order in this small-@xmath0 expansion , the order parameter satisfies a time dependent landau - ginsburg equation which has @xmath1 , but non - dissipative .
these predictions are verified by explicit numerical solutions of the bulk equations of motion . uk/12 - 12 + pupt-2431 + * quantum quench across a zero temperature holographic superfluid transition * + pallab basu@xmath2 , diptarka das @xmath2 , sumit r. das @xmath2 and tatsuma nishioka @xmath3 @xmath2 _ department of physics and astronomy , + university of kentucky , lexington , ky 40506 , usa
_ + @xmath3_department of physics , + princeton university , princeton , nj 08564 , usa _ .
And you have already written the first three sentences of the full article: recently there has been several efforts to understand the problem of quantum or thermal quench @xcite in strongly coupled field theories using the ads / cft correspondence @xcite .
this approach has been used to explore two interesting issues .
the first relates to the question of thermalization . in this problem.
Please generate the next two sentences of the article | one typically considers a coupling in the hamiltonian which varies appreciably with time over some finite time interval .
starting with a nice initial state ( e.g. the vacuum ) the question is whether the system evolves into some steady state and whether this steady state resembles a thermal state in a suitably defined sense . in the bulk description |
3,263 | Suppose that you have an abstract for a scientific paper: we have performed high field magnetotransport measurements to investigate the interface electron gas in laalo@xmath0/srtio@xmath0 heterostructures .
shubnikov - de haas oscillations reveal several 2d conduction subbands with carrier effective masses between 1 and 3 @xmath1 , quantum mobilities of order @xmath2 @xmath3/v s , and band edges only a few millielectronvolts below the fermi energy .
measurements in tilted magnetic fields confirm the 2d character of the electron gas , and show evidence of inter - subband scattering . .
And you have already written the first three sentences of the full article: it is now well - established that a two - dimensional electron gas ( 2deg ) can exist at the interface between perovskite oxides laalo@xmath0 ( lao ) and srtio@xmath0 ( sto ) @xcite .
the 2deg is nominally similar to those in semiconductor heterostructures , but supports additional phases , such as superconductivity and magnetism , which are not observed in conventional 2d electron systems , and which have great fundamental and technological interest @xcite .
the mechanism of formation of this oxide 2deg , however , is not established , and although there is a general consensus that the charge carriers occupy sto conduction bands modified by the presence of the interface @xcite , the origin and density of the 2d carriers , and the details of the electronic bandstructure at the interface are not yet fully understood ..
Please generate the next two sentences of the article | three main scenarios have emerged as the possible source of conduction electrons : electronic reconstruction , where a build - up of electric potential across the polar lao layers is avoided by charge transfer from lao to sto @xcite ; donation of electrons by oxygen vacancies in the heterostructure @xcite ; and cationic intermixing and disorder across the interface @xcite .
the relative contributions of these mechanisms seem to be determined by factors such as the sample growth conditions , the lao layer thickness , and the overall integrity of the crystal structure . |
3,264 | Suppose that you have an abstract for a scientific paper: in this paper we analyze the interaction of a uniformly accelerated detector with a quantum field in ( 3 + 1)d spacetime , aiming at the issue of how kinematics can render vacuum fluctuations the appearance of thermal radiance in the detector ( unruh effect ) and how they engender flux of radiation for observers afar .
two basic questions are addressed in this study : a ) how are vacuum fluctuations related to the emitted radiation ?
b ) is there emitted radiation with energy flux in the unruh effect ?
we adopt a method which places the detector and the field on an equal footing and derive the two - point correlation functions of the detector and of the field separately with full account of their interplay . from the exact solutions , we are able to study the complete process from the initial transient to the final steady state ,
keeping track of all activities they engage in and the physical effects manifested .
we derive a quantum radiation formula for a minkowski observer .
we find that there does exist a positive radiated power of quantum nature emitted by the detector , with a hint of certain features of the unruh effect .
we further verify that the total energy of the dressed detector and a part of the radiated energy from the detector is conserved .
however , this part of the radiation ceases in steady state .
so the hint of the unruh effect in radiated power is actually not directly from the energy flux that the detector experiences in unruh effect . since all the relevant quantum and statistical information about the detector ( atom ) and
the field can be obtained from the results presented here , they are expected to be useful , when appropriately generalized , for addressing issues of quantum information processing in atomic and optical systems , such as quantum decoherence , entanglement and teleportation . .
And you have already written the first three sentences of the full article: inasmuch as studies of the interaction between a particle and a quantum field are basic to particle physics and field theory , understanding the interaction between an atom and a quantum field is essential to current atomic and optical physics research @xcite .
the interaction of an accelerated charge or detector ( an object with some internal degrees of freedom such as an atom or harmonic oscillator ) in a quantum field is a simple yet fundamental problem with many implications in quantum field theory @xcite , thermodynamics @xcite and applications in radiation theory and atomic - optical physics .
it is common knowledge that accelerating charges give rise to radiation @xcite ..
Please generate the next two sentences of the article | but it is not entirely straightforward to derive the radiation formula from quantum field theory .
how are vacuum fluctuations related to the emitted radiation ? |
3,265 | Suppose that you have an abstract for a scientific paper: the chiral spin - glass potts system with @xmath0 states is studied in @xmath1 and 3 spatial dimensions by renormalization - group theory and the global phase diagrams are calculated in temperature , chirality concentration @xmath2 , and chirality - breaking concentration @xmath3 , with determination of phase chaos and phase - boundary chaos . in the @xmath4 ,
the system has ferromagnetic , left - chiral , right - chiral , chiral spin - glass , and disordered phases .
the phase boundaries to the ferromagnetic , left- and right - chiral phases show , differently , an unusual , fibrous patchwork ( microreentrances ) of all four ( ferromagnetic , left - chiral , right - chiral , chiral spin - glass ) ordered ordered phases , especially in the multicritical region .
the chaotic behavior of the interactions , under scale change , are determined in the chiral spin - glass phase and on the boundary between the chiral spin - glass and disordered phases , showing lyapunov exponents in magnitudes reversed from the usual ferromagnetic - antiferromagnetic spin - glass systems . at low temperatures ,
the boundaries of the left- and right - chiral phases become thresholded in @xmath2 and @xmath3 . in the @xmath1 ,
the chiral spin - glass system does not have a spin - glass phase , consistently with the lower - critical dimension of ferromagnetic - antiferromagnetic spin glasses .
the left- and right - chirally ordered phases show reentrance in chirality concentration @xmath2 .
chiral potts spin glass , in temperature @xmath5 , chirality concentration @xmath2 , and chirality - breaking concentration @xmath3 .
note that the upper and lower figures are rotated with respect to each other . the ferromagnetically ordered phase ( f ) , the chiral spin - glass phase ( s ) , the left - chirally ordered phase ( l ) , and the disordered phase ( d ) are marked .
the global phase diagram is mirror - symmetric with respect to the chirality - breaking concentration @xmath6 , so that only @xmath7 is shown . in the (....
And you have already written the first three sentences of the full article: the chiral potts model was originally introduced @xcite to model the full phase diagram of krypton monolayers , including the epitaxial and incommensurate ordered phases . in addition to being useful in the analysis of surface layers , the chiral potts model has become an important model of phase transitions and critical phenomena .
we have studied the chiral spin - glass potts system with @xmath0 states in @xmath1 and 3 spatial dimensions by renormalization - group theory and calculated the global phase diagrams in temperature , chirality concentration @xmath2 , and chirality - breaking concentration @xmath3 , also quantitatively determining phase chaos and phase - boundary chaos . in the @xmath9 ,
the system has ferromagnetic , left - chiral , right - chiral , chiral spin - glass , and disordered phases ..
Please generate the next two sentences of the article | the phase boundaries to the ferromagnetic , left- and right - chiral phases show , differently , an unusual , fibrous patchwork ( microreentrances ) of all four ( ferromagnetic , left - chiral , right - chiral , chiral spin - glass ) ordered phases , especially in the multicritical region .
the chaotic behavior of the interactions , under scale change , is determined in the chiral spin - glass phase and on the boundary between the chiral spin - glass and disordered phases , showing lyapunov exponents in magnitudes reversed from the usual ferromagnetic - antiferromagnetic spin - glass systems . at low temperatures , the boundaries of the left- and right - chiral phases become thresholded in @xmath2 and @xmath3 . in the @xmath1 , |
3,266 | Suppose that you have an abstract for a scientific paper: we analyze the directed flow of protons and pions in high - energy heavy - ion collisions in the incident energy range from @xmath0 to 27 gev within a microscopic transport model .
standard hadronic transport approaches do not describe the collapse of directed flow below @xmath1 gev .
by contrast , a model that simulates effects of a softening of the equation of state describes well the behavior of directed flow data recently obtained by the star collaboration @xcite .
we give a detailed analysis of how directed flow is generated .
particularly , we found that softening of the effective equation of state at the overlapping region of two nuclei , i.e. the reaction stages where the system reaches high baryon density state , is needed to explain the observed collapse of proton directed flow within a hadronic transport approach . .
And you have already written the first three sentences of the full article: detecting the qcd phase transition is of primary interest in current nuclear and particle physics .
experiments have shown that a new form of strongly interacting matter is created in high - energy nuclear collisions at the relativistic heavy ion collider ( rhic ) top energy and the large hadron collider ( lhc ) energies @xcite .
theoretical arguments and experimental signals imply that this matter is a quark - gluon plasma ( qgp ) created well above a transition temperature at almost zero baryon chemical potential ..
Please generate the next two sentences of the article | the lattice qcd calculations have confirmed that the transition from hadronic matter to qgp is a crossover at zero baryon density @xcite .
the next challenge is to discover the first and/or second - order phase transition of qcd matter . |
3,267 | Suppose that you have an abstract for a scientific paper: we set up a new calculational framework for the yang - mills vacuum transition amplitude in the schrdinger representation . after integrating out hard - mode contributions perturbatively ,
we perform a gauge invariant gradient expansion of the ensuing soft mode action which renders a subsequent saddle point expansion for the vacuum overlap manageable .
the standard `` squeezed '' approximation for the vacuum wave functional then allows for an essentially analytical treatment of physical amplitudes .
moreover , it leads to the identification of dominant and gauge invariant classes of gauge field orbits which play the role of gluonic infrared ( ir ) degrees of freedom . those emerge as a rich variety of ( mostly solitonic ) solutions to the saddle point equations which are characterized by a common relative gauge orientation of the underlying gluon fields .
we discuss their scale stability , guaranteed by a virial theorem , and other general properties including topological quantum numbers and action bounds .
we then find important saddle point solutions explicitly and examine their physical impact .
some of them are related to tunneling solutions of the classical yang - mills equation , i.e. to instantons and merons , while others appear to play unprecedented roles .
a remarkable new class of ir degrees of freedom comprises vortex and knot solutions of faddeev - niemi type , potentially related to glueballs . .
And you have already written the first three sentences of the full article: the strong couplings among soft qcd gluons manifest themselves in a variety of complex long - distance phenomena .
most of them are thoroughly entwined with the vacuum state , as illustrated by such prominent examples as quark confinement , spontaneous chiral symmetry breaking , vacuum tunneling processes , the ensuing @xmath0 structure as well as large gluon condensates . despite the apparent diversity of these and other effects
, however , the essence of the underlying dynamics is often expected to involve just a few soft gluonic modes ..
Please generate the next two sentences of the article | the quest for these long - wavelength excitations began shortly after the inception of qcd and has inspired the development of various kinds of vacuum models , based e.g. on glueball condensation @xcite , gaussian stochastic processes @xcite , gluonic domains @xcite and instanton @xcite as well as meron @xcite ensembles . over the last decade , lattice simulations increasingly assisted in the search for predominant infrared ( ir ) gluon fields , mostly by means of numerical `` filtering '' @xcite and gauge - fixing @xcite techniques .
these simulations are now beginning to generate quantitative insights into the role of instantons and their size distribution @xcite , and into the classic confinement scenarios based on ( gauge - projected abelian ) monopole @xcite or center vortex @xcite condensation . |
3,268 | Suppose that you have an abstract for a scientific paper: we present the lattice models with exact fermionic symmetries relating fermions and link variables .
the plaquettes are distributed in an ichimatsu pattern ( chequered ) .
we explain this peculiar structure allows us to have a translation in the algebra of the fermionic symmetries . .
And you have already written the first three sentences of the full article: to study dynamics of super yang - mills theory , a lattice formulation is an attractive tool .
there are some approaches , however limited , not exact , realization has done @xcite .
why do we stress the exact symmetry ?.
Please generate the next two sentences of the article | it is because the point of our approach , the scenario is that the exact fermionic symmetry on lattice with keeping @xmath0 symmetry in the continuum limit , then it s just susy if it is not brs symmetry .
so , the first step of our trial is to construct exact fermionic , not brs - like symmetry on lattice . |
3,269 | Suppose that you have an abstract for a scientific paper: temperature dependencies of microwave surface impedance , @xmath0 , were measured for perfect _ c_-oriented ybco thin films deposited on ceo@xmath1buffered sapphire substrates .
the measurements were performed with a use of three copper cylindrical resonators operating at @xmath2 mode ( @xmath3 = 34 , 65 , 134 ghz ) , which incorporated the studied ybco films as end plates .
the measurements revealed a distinct two - peak structure of @xmath4 and @xmath5 dependencies with peaks at 2830 k and 50 k. the peaks become smeared at higher frequencies as well as in applied dc magnetic field ( @xmath6 koe ) , while the peak positions remain almost unchanged . for less perfect , e.g. , pld films , @xmath4 and @xmath5 dependencies are monotonous ( power law ) .
the two - peak @xmath7 dependencies for ybco films differ from those for high quality ybco single crystals , where only one much broader frequency - dependent peak of @xmath4 was detected earlier .
the two - peak @xmath7 behavior is believed to be an intrinsic electron property of extremely perfect quasi - single - crystalline ybco films .
a theoretical model is suggested to explain the observed anomalous @xmath7 behavior .
the model is based on the boltzman kinetic equation for quasiparticles in layered hts cuprates .
it takes into account the supposed _
s_+_d_wave symmetry of electron pairing and strong energy dependent relaxation time of quasiparticles , determined mainly by their elastic scattering on extended defects parallel to the _ c_axis ( e.g. , _ c_oriented dislocations and twin boundaries ) . .
And you have already written the first three sentences of the full article: measurement of the surface impedance @xmath8 in high-@xmath9 superconductors ( hts ) in the microwave frequency range is one of the most effective and frequently used methods to study electron properties and mechanisms of superconductivity in these materials .
such measurements , performed on high quality hts single crystals or perfect single - crystalline films , allow to obtain in a straightforward way the temperature and frequency dependencies of the complex ac conductivity of the materials @xmath10 in the microwave frequency range , that in turn yield a complimentary information on microscopic electron properties of hts , such as low - energy quasiparticle excitations from the superfluid condensate , their scattering rate and density of states , the symmetry of cooper pairing , etc .
numerous experimental and theoretical studies of the microwave response carried out during the last decade have revealed a lot of interesting features of the superconducting state in hts metal - oxide compounds and partly shed a light on the nature of superconductivity in these materials ( e.g. , _.
Please generate the next two sentences of the article | d_wave type of cooper pairing).@xcite however , up to date there is no comprehensive understanding of microwave response in hts . in particular
, this concerns the temperature dependence of surface resistance @xmath11 in highly perfect single crystals and epitaxial films , where nonmonotonous character of this dependence with a wide peak below @xmath9 was observed by many investigators . |
3,270 | Suppose that you have an abstract for a scientific paper: this note studies classical magnetohydrodynamic shock waves in an inviscid fluidic plasma that is assumed to be a perfect conductor of heat as well as of electricity . for this mathematically prototypical material
, it identifies a critical manifold in parameter space , across which slow classical mhd shock waves undergo emergence of a complex conjugate pair of unstable transverse modes . in the reflectionally symmetric case of parallel shocks
, this emergence happens at the spectral value @xmath0 , and the critical manifold possesses a simple explicit algebraic representation .
results of refined numerical treatment show that for only _ almost _ parallel shocks the unstable mode pair emerges from _ two _ spectral values @xmath1 .
= 1 .
And you have already written the first three sentences of the full article: we consider ideal mhd in twodimensional space , @xmath2 the dependent variables @xmath3 denote the fluid s density , pressure , and velocity .
in addition to , the magnetic field @xmath4 satisfies @xmath5 the fluid is assumed to be polytropic , @xmath6 , and have a constant temperature @xmath7 , so that @xmath8 with constant sound speed @xmath9 . by scaling , we assume without loss of generality that @xmath10 we abbreviate as @xmath11 with @xmath12 using , we also write it as a symmetric hyperbolic system , @xmath13 with @xmath14 , @xmath15 , and @xmath16 applying the chain rule , we rewrite as @xmath17 where @xmath18 with @xmath19 note that , as we have used on the way from to , the matrices @xmath20 and @xmath21 in are _ not _ the jacobians of the fluxes @xmath22 and @xmath23 .
ideal mhd shock waves , in their prototypical form , have the structure @xmath24 where @xmath25 is the direction of propagation and @xmath26 the speed of the shock wave ..
Please generate the next two sentences of the article | function being a weak solution of is equivalent to the rankine - hugoniot conditions @xmath27 due to rotational and galilean invariance it is without loss of generality that we henceforth assume that @xmath28 i. e. we exclusively consider shock waves of the form @xmath29 and the rankine - hugoniot conditions read @xmath30 note now first that for waves , as for any solutions of whose spatial dependence is only via @xmath31 , the divergence - free condition reduces to @xmath32 we assume and simply write @xmath33 instead of @xmath34 . in this paper , we are interested in lax shocks . following @xcite , two states @xmath35 that satisfy the rankine - hugoniot conditions constitute a @xmath36 and a @xmath37 two states do satisfy the rankine - hugoniot conditions
if and only if the two quadruples @xmath38 and @xmath39 have coinciding images under the mapping @xmath40 that @xmath22 induces by omitting its forth , trivial component , in other words if both quadruples satisfy the four equations @xmath41 for the same values of the four parameters @xmath42 . as simple arguments or @xmath43 give no lax shocks ] show , we lose no generality in assuming that @xmath44 using in and inserting the result and in then yields @xmath45 as for every solution @xmath46 of , relations , , provide unique associated values for @xmath47 and @xmath48 , understanding will give a complete picture . |
3,271 | Suppose that you have an abstract for a scientific paper: ngc 6946 , known as the fireworks galaxy because of its high supernova rate and high star formation , is embedded in a very extended hi halo .
its northern spiral arm is well detached from the galactic main body .
we found that this arm contains a large ( @xmath0 pc in size ) red ellipse , .
the ellipse is accompanied by a short parallel arc and a few others still smaller and less regular ; a bright star cluster is seen inside these features .
the complicated combination of arcs seems to be unique , it is only a bit similar to some snrs .
however , the long - slit spectral data obtained with the russian 6-m telescope did not confirm the origin of the nebula as a result of a single sn outburst .
the emission - line spectrum corresponds to the photoionization by young hot stars with a small contribution of shock ionization .
the most likely explanation of the red ellipse is a superbbuble created by a collective feedback of massive stars in the star cluster located in the ne side of the red ellipse .
however , the very regular elliptical shape of the nebulae seems strange .
[ firstpage ] hii regions galaxies : spiral galaxies : individual : ngc 6946 ism : supernova remnants galaxies : star formation .
And you have already written the first three sentences of the full article: ngc 6946 , a nearby starburst spiral galaxy , also known as the `` fireworks galaxy '' because of its prolific supernova production , is embedded in an enormous hi halo ( pisano 2014 ) .
the galaxy has a high star formation rate and a number of unusual star - forming regions , such as enigmatic hodge complex which contains a young super star cluster @xcite .
ngc 6946 is famous also for hosting the record number of observed sne ..
Please generate the next two sentences of the article | we found that apart from the above mentioned peculiarities , this galaxy hosts one more strange object , which in common images is seen as just one of its many hii regions .
however , in deep high - resolution images this object is really wonderful . |
3,272 | Suppose that you have an abstract for a scientific paper: we consider a power law @xmath0 correction to einstein gravity as a model for inflation .
the interesting feature of this form of generalization is that small deviations from the starobinsky limit @xmath1 can change the value of tensor to scalar ratio from @xmath2 to @xmath3 .
we find that in order to get large tensor perturbation @xmath4 as indicated by bkp measurements , we require the value of @xmath5 thereby breaking global weyl symmetry . we show that the general @xmath6 model can be obtained from a sugra construction by adding a power law @xmath7 term to the minimal no - scale sugra khler potential .
we further show that this two parameter power law generalization of the starobinsky model is equivalent to generalized non - minimal curvature coupled models with quantum corrected @xmath8- potentials i.e. models of the form @xmath9 and thus the power law starobinsky model is the most economical parametrization of such models .
inflation , cmb , b - mode , starobinsky model , @xmath10-theory , supergravity .
And you have already written the first three sentences of the full article: the starobinsky model of inflation @xcite with an @xmath11 interaction term is of interest as it requires no extra scalar fields but relies on the scalar degree of the metric tensor to generate the inflaton potential .
the @xmath12 starobinsky model gives rise to a plateau potential of the inflaton when transformed to the einstein frame .
this model was favored by the planck constraint on the tensor to scalar ratio which ruled out potentials like @xmath13 and @xmath14 ..
Please generate the next two sentences of the article | in addition the starobinsky model could be mapped to the higgs - inflation models with @xmath15 theory @xcite .
the characteristic feature of the starobinsky equivalent models was the prediction that the tensor to scalar ratio was @xmath16 . |
3,273 | Suppose that you have an abstract for a scientific paper: we report the discovery of a high proper motion l subdwarf ( @xmath0 yr@xmath1 ) in the sloan digital sky survey spectral database . the optical spectrum from the star sdss j125637 - 022452 has mixed spectral features of both late - m spectral subtype ( strong tio and cah at 7000 ) and mid - l spectral subtype ( strong wings of ki at 7700 , crh and feh ) , which is interpreted as the signature of a very low - mass , metal - poor star ( ultra - cool subdwarf ) of spectral type sdl .
the near infrared ( nir ) @xmath2 ) colors from 2mass shows the object to be significantly bluer compared to normal l dwarfs , which is probably due a strong collision induced absorption ( cia ) due to molecule .
this is consistent with the idea that cia from is more pronounced at low metallicities .
proper motion and radial velocity measurements also indicate that the star is kinematically `` hot '' and probably associated with the galactic halo population . .
And you have already written the first three sentences of the full article: ultra - cool dwarfs , low - mass objects of low temperature extending beyond the classical main sequence , have been identified in significant numbers from recent large optical and near infrared surveys , such as the deep near infrared survey @xcite , the sloan digital sky survey @xcite , and the two micron all - sky survey @xcite .
two new spectral type ( l , t ) have been added to classify those extremely cool objects , and these are now widely in use , with several hundred l and t dwarfs classified to date @xcite .
most stars classified as l and t dwarfs are relatively metal - rich , and associated with the galactic disk population ..
Please generate the next two sentences of the article | one also expects the solar neighborhood to be host to ultra - cool members of the galactic halo ( population ii ) .
however pop ii stars are rare in the vicinity of the sun , where they account for roughly one out of every 200 stars . |
3,274 | Suppose that you have an abstract for a scientific paper: we present photometry of 4 transits of the exoplanet wasp-4b , each with a precision of approximately 500 ppm and a time sampling of 40 - 60 s. we have used the data to refine the estimates of the system parameters and ephemerides . during two of the transits we observed a short - lived , low - amplitude anomaly that we interpret as the occultation of a starspot by the planet .
we also found evidence for a pair of similar anomalies in previously published photometry .
the recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis , or else the star spot would not have remained on the transit chord . by analyzing the timings of the anomalies we find the sky - projected stellar obliquity to be @xmath0 degrees .
this result is consistent with ( and more constraining than ) a recent observation of the rossiter - mclaughlin effect .
it suggests that the planet migration mechanism preserved the initially low obliquity , or else that tidal evolution has realigned the system .
future applications of this method using data from the _ corot _ and _ kepler _ missions will allow spin - orbit alignment to be probed for many other exoplanets . .
And you have already written the first three sentences of the full article: spots on the host stars of transiting planets have generally been regarded as a nuisance .
they interfere with the determination of the planet s properties , by causing variations in the transit depth , producing chromatic effects that can be mistaken for atmospheric absorption , and causing anomalies in individual light curves when spots are occulted by the planet ( see , e.g. , rabus et al .
2009 , knutson et al ..
Please generate the next two sentences of the article | 2009 , carter et al . 2011 ) .
silva - valio ( 2008 ) pointed out that starspots may be helpful in one respect : observations of spot - occultation anomalies in two closely - spaced transits can be used to estimate the stellar rotation period . in effect , the planet is used to reveal the longitude of the spot during each transit . for the particular case of corot-2 , silva - valio et al . |
3,275 | Suppose that you have an abstract for a scientific paper: we introduce a system with one or two amplified nonlinear sites ( hot spots " , hss ) embedded into a two - dimensional linear lossy lattice .
the system describes an array of evanescently coupled optical or plasmonic waveguides , with gain applied to selected hs cores .
the subject of the analysis is discrete solitons pinned to the hss .
the shape of the localized modes is found in quasi - analytical and numerical forms , using a truncated lattice for the analytical consideration .
stability eigenvalues are computed numerically , and the results are supplemented by direct numerical simulations . in the case of self - focusing nonlinearity ,
the modes pinned to a single hs are stable and unstable when the nonlinearity includes the cubic loss and gain , respectively .
if the nonlinearity is self - defocusing , the _ unsaturated _ cubic gain acting at the hs supports _ stable _ modes in a small parametric area , while weak cubic loss gives rise to a _
bistability _ of the discrete solitons .
symmetric and antisymmetric modes pinned to a symmetric set of two hss are considered as well . .
And you have already written the first three sentences of the full article: modes of fundamental significance to nonlinear optics @xcite and plasmonics plas1,plas3,plas4,plas5,plas6,plas7,plas8,plas9,marini , korea are dissipative spatial solitons that result from the simultaneous balance among diffraction , self - focusing nonlinearity , loss , and compensating gain .
stability is a crucially important issue in the theoretical analysis of dissipative solitons .
an obvious necessary condition for the stability of localized modes is the stability of the zero background around them ..
Please generate the next two sentences of the article | the basic complex ginzburg - landau ( cgl ) equation , which includes the bandwidth - limited linear gain and nonlinear loss acting on a single field , is unable to produce stable dissipative solitons , since the action of the linear gain on the zero background makes it unstable . on the other hand , dissipative solitons can be fully stabilized in systems of linearly coupled cgl equations @xcite modeling dual - core waveguides , with the linear gain and loss acting in different cores marini , dual1,dual2,dual3,dual4,dual5 , including the @xmath0-symmetric version of the system that features the balance between the gain and loss @xcite .
stable solitons can also be generated by a single cgl equation with cubic gain sandwiched " between linear and quintic losses , which may be realized in optics as a combination of linear amplification and power - dependent absorption cq1,cq2,cq3,cq4,cq5,cq6,cqgle1,cqgle2,cqgle3,cqgle4,cqgle5 . |
3,276 | Suppose that you have an abstract for a scientific paper: we calculate the perturbative value of the free energy in lattice qcd , up to three loops .
our calculation is performed using wilson gluons and the sheikholeslami - wolhert ( clover ) improved action for fermions . the free energy is directly related to the average plaquette . to carry out the calculation ,
we compute all relevant feynman diagrams up to 3 loops , using a set of automated procedures in mathematica ; numerical evaluation of the resulting loop integrals is performed on finite lattice , with subsequent extrapolation to infinite size .
the results are presented as a function of the fermion mass @xmath0 , for any @xmath1 gauge group , and for an arbitrary number of fermion flavors . in order to enable independent comparisons
, we also provide the results on a _ per diagram _ basis , for a specific mass value .
lattice perturbation theory , free energy , average plaquette , clover action , 11.15.ha , 12.38.gc , 12.38.bx .
And you have already written the first three sentences of the full article: in this work we calculate the free energy of qcd on the lattice , up to three loops in perturbation theory .
we employ wilson gluons and the @xmath2 improved sheikholeslami - wohlert ( clover ) @xcite action for fermions .
the purpose of this action is to reduce finite lattice spacing effects , leading to a faster approach to the continuum ..
Please generate the next two sentences of the article | dynamical simulations employing the clover action are currently in progress by the cp - pacs / jlqcd @xcite and ukqcdsf @xcite collaborations and therefore perturbative studies of properties of the qcd action with clover quarks are worthy of being undertaken .
the free energy , in the simpler case of wilson fermions , was studied in @xcite . |
3,277 | Suppose that you have an abstract for a scientific paper: let @xmath0 be the automorphism group of a regular right - angled building @xmath1 .
the
standard uniform lattice " @xmath2 is a canonical graph product of finite groups , which acts discretely on @xmath1 with quotient a chamber .
we prove that the commensurator of @xmath3 is dense in @xmath0 . for this
, we develop a technique of unfoldings " of complexes of groups .
we use unfoldings to construct a sequence of uniform lattices @xmath4 , each commensurable to @xmath5 , and then apply the theory of group actions on complexes of groups to the sequence @xmath6 . as further applications of unfoldings ,
we determine exactly when the group @xmath0 is nondiscrete , and we prove that @xmath0 acts strongly transitively on @xmath1 . .
And you have already written the first three sentences of the full article: two subgroups @xmath5 and @xmath7 of a group @xmath0 are _ commensurable _ if the intersection @xmath8 has finite index in both @xmath5 and @xmath7 .
the _ commensurator _ of @xmath9 in @xmath0 is the group @xmath10 note that @xmath11 contains the normalizer @xmath12 .
it is a classical fact that if @xmath0 is a connected semisimple lie group , with trivial center and no compact factors , and @xmath9 is an irreducible lattice , then either @xmath13 is finite index in @xmath14 or @xmath14 is dense in @xmath0 ( see @xcite ) ..
Please generate the next two sentences of the article | moreover margulis @xcite proved that @xmath13 is arithmetic if and only if @xmath14 is dense .
a semisimple lie group is a locally compact topological group . if @xmath1 is a locally finite , simply connected polyhedral complex , then the group @xmath15 is also locally compact . |
3,278 | Suppose that you have an abstract for a scientific paper: we examine the influence of microwave photoexcitation on the amplitude of shubnikov - de haas ( sdh ) oscillations in a two dimensional gaas / algaas electron system in a regime where the cyclotron frequency , @xmath0 , and the microwave angular frequency , @xmath1 , satisfy @xmath2 .
a sdh lineshape analysis indicates that increasing the incident microwave power has a weak effect on the amplitude of the sdh oscillations , in comparison to the influence of modest temperature changes on the dark - specimen sdh effect .
the results indicate negligible electron heating under modest microwave photoexcitation , in good agreement with theoretical predictions . .
And you have already written the first three sentences of the full article: the gaas / algaas quasi two - dimensional electron system has served as the basis for many interesting developments in modern condensed matter physics.@xcite in the recent past , photo - excited transport studies in this system have become a topic of experimental@xcite and theoretical@xcite interest since the observation of zero - resistance states and associated magneto - resistance oscillations in the microwave excited two - dimensional electron system.@xcite .
periodic in @xmath3 radiation - induced magnetoresistance oscillations , which lead into the radiation - induced zero - resistance states , are now understood to be a consequence of radiation - frequency ( @xmath4 ) , and magnetic field ( @xmath5 ) dependent , scattering at impurities @xcite and/or a change in the distribution function,@xcite while vanishing resistance is thought to be an outcome of negative resistance instability and current domain formation.@xcite although there has been much progress in this field , there remain many aspects , such as indications of activated transport , the overlap with quantum hall effect , and the influence of the scattering lifetimes , that could be better understood from both the experimental and theoretical perspectives .
a further topic of experimental interest is to examine the possibility of electron heating , as theory has,@xcite in consistency with common experience , indicated the possibility of microwave - induced electron heating in the high mobility 2des in the regime of the radiation - induced magnetoresistance oscillations ..
Please generate the next two sentences of the article | not surprisingly , under steady state microwave excitation , the 2des can be expected to absorb energy from the radiation field . at the same time
, electron - phonon scattering can serve to dissipate this surplus energy onto the host lattice . |
3,279 | Suppose that you have an abstract for a scientific paper: we formulate a two - patch mathematical model for ebola virus disease dynamics in order to evaluate the effectiveness of _ cordons sanitaires _ , mandatory movement restrictions between communities while exploring their role on disease dynamics and final epidemic size .
simulations show that severe restrictions in movement between high and low risk areas of closely linked communities may have a deleterious impact on the overall levels of infection in the total population .
* keywords : * ebola virus disease , asymptomatic , final size relation , residence times . .
And you have already written the first three sentences of the full article: ebola virus disease ( evd ) is caused by a genus of the family _ filoviridae _ called _ ebolavirus_. the first recorded outbreak took place in sudan in 1976 with the longest most severe outbreak taking place in west africa during 2014 - 2015 @xcite .
studies have estimated disease growth rates and explored the impact of interventions aimed at reducing the final epidemic size @xcite . despite these efforts , research that improves and increases our understanding of evd and the environments where it thrives is still needed @xcite . +
this chapter is organized as follows : section 2 reviews past modeling work ; section three introduces a single patch model , its associated basic reproduction number @xmath0 , and the final size relationship ; section four introduces a two - patch model that accounts for the time spent by residents of patch @xmath1 on patch @xmath2 ; section 5 includes selected simulations that highlight the possible implications of policies that forcefully restrict movement ( _ cordons sanitaires_);and , section 6 collects our thoughts on the relationship between movement , health disparities , and risk ..
Please generate the next two sentences of the article | chowell et _ al . _
@xcite estimated the basic reproduction numbers for the 1995 outbreak in the democratic republic of congo and the 2000 outbreak in uganda . |
3,280 | Suppose that you have an abstract for a scientific paper: this paper reports on peculiar metamagnetic transitions which take place in antiferromagnetic , charge and orbitally ordered ( afcoo ) manganites . at very low temperatures , the virgin magnetization curves of some of these compounds
exhibit several , sharp steps giving rise to a staircase - like shape .
this staircase effect is shown to be sensitive to various experimental parameters .
several potential interpretations of the staircase effect are discussed in relation to this set of results . a martensitic - like scenario , involving a leading role of the structural distortions associated to the collapse of the orbital ordering , is found to be the most plausible interpretation . .
And you have already written the first three sentences of the full article: mixed - valent manganites of formulation re@xmath0ae@xmath1mno@xmath2 ( re being a trivalent rare - earth ion , and ae a divalent alkaline - earth ion ) exhibit a great variety of fascinating properties , such as charge ordering ( real - space ordering of the mn@xmath3and mn@xmath4species ) and colossal magnetoresistance ( collapse of the resistivity by several orders of magnitude under application of an external magnetic field).@xcite charge ordering is often accompanied by a long - range ordering of the mn@xmath5 e@xmath6 orbitals , leading to prominent structural distortions . in pr@xmath7ca@xmath1mno@xmath2 compounds with @xmath8 , the small a - site cationic radius and the mn@xmath9mn@xmath3 ratio close to 1
contribute to the setting up of a particular groundstate , which is both charge and orbitally ordered , insulating and antiferromagnetic of ce type ( hereafter referred to as afcoo ) .
application of magnetic fields can affect the subtle energy balance in these systems , and trigger the development of a ferromagnetic , conducting state ( hereafter referred to as f ) ..
Please generate the next two sentences of the article | this process is at the origin of the most spectacular effects of colossal magnetoresistance in manganites .
however , very high magnetic fields are required to melt the robust afcoo state present for @xmath10 ( about 25 t at 4 k).@xcite for compositions shifted towards @xmath11 , lower fields are needed ( e.g. , about 5 t for @xmath12).@xcite mn - site substitutions can also weaken the afcoo state,@xcite making it susceptible to undergo an afcoo - f transition at low - t under moderate fields . |
3,281 | Suppose that you have an abstract for a scientific paper: we review the way intense neutrino beams at the front
end of a muon storage ring can be used to probe the structure of hadrons .
specifically , we discuss how the polarized and unpolarized flavor structure of the nucleon can be disentangled in inclusive deep - inelastic scattering , and how less inclusive measurements can shed light on various aspects of hadron structure such as fragmentation functions or generalized parton distributions .
hep - ph/0207209 + rm3th/02 - 10 + .3 cm * hadron physics at a neutrino factory * .5 cm stefano forte .3 cm _ infn , sezione di roma iii , + via della vasca navale 84 , i00146 roma , italy _
* abstract * we review the way intense neutrino beams at the front
end of a muon storage ring can be used to probe the structure of hadrons .
specifically , we discuss how the polarized and unpolarized flavor structure of the nucleon can be disentangled in inclusive deep - inelastic scattering , and how less inclusive measurements can shed light on various aspects of hadron structure such as fragmentation functions or generalized parton distributions .
2.5 cm invited talk at * qcd - n02 * + ferrara , italy , april 2002 + _ to be published in the proceedings _ .
And you have already written the first three sentences of the full article: the use of a muon storage ring as an intense source of neutrinos has attracted renewed attention : it is a natural stepping stone toward a muon collider , and it would offer a wealth of opportunities for doing physics both of neutrinos ( long baseline ) , and with neutrinos ( front - end ) . whereas the physics of neutrino oscillations , and in particular the possibility of discovering cp violation in the neutrino sector provide some of the strongest motivations for a neutrino factory , a sizable part of the physics program at such a facility should be devoted to the use of the neutrino beam as a probe of matter .
end physics at a neutrino factory is based on the realization that , because of the flavor and spin structure of the coupling of neutrinos to weak currents , a neutrino beam has a greater physics potential than conventional electron or muon beams , and it can be used to perform tests of unsurpassed precision of the standard model , and as a probe of hadron structure of unique sensitivity . here
we will briefly review the potential of neutrino beams as probes of matter ..
Please generate the next two sentences of the article | first , we will review deep - inelastic scattering ( dis ) with neutrino beams , and show that it can be used to sort out the flavor structure of parton distributions of the nucleon , both polarized and unpolarized .
then , we will consider increasingly less inclusive measurements , and see how they can be used to shed light on various other aspects of hadron structure , such as fragmentation functions and generalized parton distributions . |
3,282 | Suppose that you have an abstract for a scientific paper: in the present paper we derive a unified new integral whose integrand contains products of fox @xmath0-function and a general class of polynomials having general arguments . a large number of integrals involving various simpler functions follow as special cases of this integral .
= msam10 at 10pt = mtgub at 10.4pt = tibi at 10.4pt [ theore]*theorem * [ theore]proposition [ theore]lemma [ theore]definition [ theore]corollary [ theore]remark [ theore]example .
And you have already written the first three sentences of the full article: the @xmath0-function introduced by fox @xcite , will be represented and defined in the following manner : @xmath1 & = h_{p , q}^{m , n } \left\lbrack x \bigg| \begin{array}{@{}l@ { } } ( a_{1 } , \alpha_{1 } ) , \ldots , ( a_{p } , \alpha_{p})\\[.2pc ] ( b_{1 } , \beta_{1 } ) , \ldots , ( b_{q } , \beta_{q } ) \end{array}\right\rbrack\nonumber\\[.2pc ] & = \frac{1}{2 \pi i } \int_{l }
\frac{\prod_{j = 1}^{m } \gamma ( b_{j } - \beta_{j } \xi ) \prod_{j = 1}^{n } \gamma ( 1 - a_{j } + \alpha_{j } \xi)}{\prod_{j = m + 1}^{q } \gamma ( 1 - b_{j } + \beta_{j } \xi ) \prod_{j = n + 1}^{p } \gamma ( a_{j } - \alpha_{j } \xi ) } x^{\xi } \ { \rm d}\xi.\end{aligned}\ ] ] for the nature of contour @xmath2 in ( 1.1 ) , the convergence , existence conditions and other details of the @xmath0-function , one can refer to @xcite .
the general class of polynomials introduced by srivastava @xcite is defined in the following manner : @xmath3 = \sum\limits_{k = 0}^{[v / u ] } \frac{(-v)_{uk } a ( v , k)}{k ! } x^{k } , \quad v = 0 , 1 , 2 , \ldots,\ ] ] where @xmath4 is an arbitrary positive integer and coefficients @xmath5 are arbitrary constants , real or complex ..
Please generate the next two sentences of the article | @xmath6^{-\nu } h_{p , q}^{m , n } [ y \ { x + a + ( x^{2 } + 2ax)^{1/2 } \}^{-\mu}]\nonumber\\ & \qquad\qquad \times s_{v}^{u } [ z \ { x + a + ( x^{2 } + 2ax)^{1/2 } \}^{-\alpha } ] \hbox{d}x\nonumber\end{aligned}\ ] ] @xmath7 } ( -v)_{uk } a ( v , k ) \frac{(z / a^{\alpha})^{k}}{k ! } h_{p + 2 , q + 2}^{m , n + 2}\nonumber\\[.2pc ] & \quad\ , \times \left\lbrack ya^{-\mu } \bigg| \begin{array}{@{}l@ { } } ( -\nu - \alpha k , \mu ) , ( 1 + \lambda - \nu - \alpha k , \mu ) , ( a_{1 } , \alpha_{1 } ) , \ldots , ( a_{p } , \alpha_{p})\\[.2pc ] ( b_{1 } , \beta_{1}),\ldots,(b_{q } , \beta_{q } ) , ( 1 - \nu - \alpha k , \mu ) , ( -\nu - \alpha k - \lambda , \mu ) \end{array } \!\right\rbrack,\end{aligned}\ ] ] where 1 .
@xmath8 , 2 . |
3,283 | Suppose that you have an abstract for a scientific paper: initial states of glasma in high energy heavy ion collisions are longitudinal classical color electric and magnetic fields . assuming finite color electric conductivity , we show that the color electric field decays by quark pair production with the life time of the order of @xmath0 , i.e. the inverse of the saturation momentum .
quarks and anti - quarks created in the pair production are immediately thermalized as far as their temperature @xmath1 is lower than @xmath2 .
namely , a relaxation time of the quarks to be thermalized is much shorter than @xmath0 when @xmath3 .
we also show that the quarks acquire longitudinal momentum of the order of @xmath2 by the acceleration of the electric field . to discuss the quark pair production , we use chiral anomaly which has been shown to be very powerful tool in the presence of strong magnetic field . .
And you have already written the first three sentences of the full article: initial states of color gauge fields ( glasma ) produced immediately after high energy heavy - ion collisions have recently received much attention . the gauge fields are longitudinal classical color electric and magnetic fields ;
their field strengths are given by the square of the saturation momentum @xmath2 .
the presence of such classical gauge fields has been discussed on the basis of a fairly reliable effective theory of qcd at high energies , that is , a model of color glass condensate ( cgc)@xcite ..
Please generate the next two sentences of the article | it is expected that the decay of the glasma leads to thermalized quark gluon plasma ( qgp ) .
the glasma is homogeneous in the longitudinal direction and inhomogeneous in the transverse directions . |
3,284 | Suppose that you have an abstract for a scientific paper: we examine the wavelength dependence of flux ratios for six gravitationally lensed quasars using @xmath0 and @xmath1 images obtained at the gemini north 8 m telescope .
we select lenses with source redshifts @xmath2 so that @xmath0-band images probe rest - frame optical emission from accretion disks , while @xmath1-band images probe rest - frame near - infrared flux emitted ( in part ) from the more extended surrounding torus . since the observations correspond to different source sizes , the @xmath0 and @xmath1 flux ratios are sensitive to structure on different scales and may be useful for studying small - structure in the lens galaxies .
four of the six lenses show differences between @xmath0 and @xmath1 flux ratios . in he 0435@xmath31223 , sdss 0246@xmath30825 , and he 2149@xmath32745 the differences may be attributable to known microlensing and/or intrinsic variability . in sdss 0806 + 2006 the wavelength dependence is not easily attributed to known variations , and may indicate the presence of substructure .
by contrast , in q0142@xmath3100 and sbs 0909 + 523 the @xmath0 and @xmath1 flux ratios are consistent within the uncertainties .
we discuss the utility of the current data for studying chromatic effects related to microlensing , dust extinction , and dark matter substructure . .
And you have already written the first three sentences of the full article: while the cold dark matter ( cdm ) paradigm for structure formation successfully describes cosmological observations on large ( cmb and cluster ) scales , there is notable disagreement with small - scale observations . among other issues , @xmath4-body simulations ( e.g. , via lactea diemand et al .
2008 ; aquarius springel et al . 2008 ) predict the existence of numerous cdm subhalos , with masses @xmath5@xmath6 , embedded in galaxy - scale dark matter halos . this has proved troubling observationally , because there are many fewer dwarf galaxies in our own milky way than predicted by cdm . since the discrepancy may be due to baryon stripping from subhalos ( e.g. , * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article | * ) , we need ways to probe dark matter substructure directly , regardless of the presence of baryonic material . gravitational lensing provides a unique way to detect cdm substructure in distant galaxies ( e.g. , * ? ? ?
* ; * ? ? ? |
3,285 | Suppose that you have an abstract for a scientific paper: _ inclusive as well as exclusive energy spectra of the light charged particles emitted in the @xmath0si(e@xmath1 mev ) + @xmath0si,@xmath2c reactions have been measured at the strasbourg vivitron facility in a wide angular range 15@xmath3 - 150@xmath3 , using the icare multidetector array .
the observed @xmath4-particle energy spectra are generally well reproduced by the statistical model using a spin - dependent level density parameterisation .
the results suggest significant deformation effects at high spin . _
23 true cm 16 true cm 0 true cm 0 true cm -1 true cm 5.0 cm * abstract * 2.0 cm .
And you have already written the first three sentences of the full article: 1.2 cm in recent years , a number of experimental and theoretical studies have been made to understand the decay of light di - nuclear systems ( a @xmath5 60 ) formed through low - energy ( e@xmath6 @xmath5 10 mev / nucleon ) , heavy - ion reactions . in most of the reactions
studied , the properties of the observed , fully energy damped yields have been successfully explained in terms of either a fusion - fission ( ff ) mechanism or a heavy - ion resonance behavior @xcite .
the strong resonance - like structures observed in elastic and inelastic excitation functions of @xmath7mg+@xmath7 mg @xcite and @xmath0si+@xmath0si @xcite have indicated the presence of shell stabilized , highly deformed configurations in the @xmath8cr and @xmath9ni compound systems , respectively . in a recent experiment using eurogam ,.
Please generate the next two sentences of the article | the present collaboration studied the possibility of preferential population of highly deformed bands in the symmetric fission channel of the @xmath9ni compound nucleus as produced through the @xmath0si+@xmath0si @xcite reaction at e@xmath10 mev .
the present work aims to investigate the possible occurence of highly deformed configurations of the @xmath9ni and @xmath11ca di - nuclei produced in the @xmath0si+@xmath0si and @xmath0si+@xmath2c reactions through the study of light charged particle ( lcp ) emission . in - plane coincidences of the lcp s with both evaporation residues ( er ) and ff fragments have been measured . |
3,286 | Suppose that you have an abstract for a scientific paper: in this paper we analyze the dynamics in a spin - model of quantum computer .
main attention is paid to the dynamical fidelity ( associated with dynamical errors ) of an algorithm that allows to create an entangled state for remote qubits .
we show that in the regime of selective resonant excitations of qubits there is no any danger of quantum chaos .
moreover , in this regime a modified perturbation theory gives an adequate description of the dynamics of the system .
our approach allows to explicitly describe all peculiarities of the evolution of the system under time - dependent pulses corresponding to a quantum protocol .
specifically , we analyze , both analytically and numerically , how the fidelity decreases in dependence on the model parameters . .
And you have already written the first three sentences of the full article: many suggestions for an experimental realization of quantum computers are related to two - level systems ( _ qubits _ ) .
one of the serious problems in this field is a destructive influence of different kinds of errors that may be dangerous for the stability of quantum computation protocols . in the first line
, one should refer to finite temperature effects and interaction of qubits with an environment @xcite ..
Please generate the next two sentences of the article | however , even in the case when these features can be neglected , errors can be generated by the dynamics itself .
this `` dynamical noise '' can not be avoided since the interaction between qubits and with external fields are both necessary for the implementation of any quantum protocol . on the other hand , the inter |
3,287 | Suppose that you have an abstract for a scientific paper: we report here on the observation of kes27 , a proto - typical mixed - morphology snr , using asca .
it clearly shows a filled - center structure in the x - ray region while a shell structure in the radio region .
there are two radio bright regions : one is in the center , while the other is in the east rim .
the x - ray intensity peak coincides well with the radio bright region at the center .
the x - ray spectrum was well - fitted by a collisional ionization equilibrium model with solar abundances .
taking into account the ionization parameter ( @xmath010@xmath1@xmath2s ) and the plasma density ( 0.39@xmath3@xmath2 ) , we found that the age of the snr is longer than @xmath4 yr .
the hardness ratio map indicates that the inner region shows a harder spectrum than that in the outer region , which does not come from the heavier interstellar absorption feature , but from the higher temperature .
there is a temperature gradient from the innner region ( [email protected] kev ) toward outer region ( 0.59@xmath6 kev ) , indicating that the thermal conduction does not play an important role . .
And you have already written the first three sentences of the full article: there are two types of supernova remnants ( snrs ) in the x - ray region from a morphological point of view : a shell structure and a filled - center structure .
some snrs in each type contain a point source at its center .
therefore , the point source at its center does not always affect the morphology of the snr ..
Please generate the next two sentences of the article | the shell structure is generated as the result of a blast wave propagating inside the interstellar matter ( ism ) , while the origin of the filled - center structure has not yet been established .
a cloud evaporation model can explain the filled - center structure ( white , long 1991 ) . the clouds in the interstellar space will gradually evaporate after passage of the blast wave , which enhances the brightness of the central part of the snr , resulting in the filled - center structure . |
3,288 | Suppose that you have an abstract for a scientific paper: we investigate antiferromagnetic order of repulsively interacting fermionic atoms in an optical lattice by means of dynamical mean - field theory ( dmft ) .
special attention is paid to the case of an imbalanced mixture .
we take into account the presence of an underlying harmonic trap , both in a local density approximation and by performing full real - space dmft calculations .
we consider the case that the particle density in the trap center is at half filling , leading to an antiferromagnetic region in the center , surrounded by a fermi liquid region at the edge . in the case of an imbalanced mixture
, the antiferromagnetism is directed perpendicular to the ferromagnetic polarization and canted .
we pay special attention to the boundary structure between the antiferromagnetic and the fermi liquid phase . for the moderately strong interactions considered here , no stoner instability toward a ferromagnetic phase
is found .
phase separation is only observed for strong imbalance and sufficiently large repulsion . .
And you have already written the first three sentences of the full article: ultracold atoms in optical lattices provide a versatile laboratory for interacting quantum many body systems @xcite .
one of the major challenges in this field is the experimental investigation of quantum magnetism in atomic mixtures .
impressive experimental progress in this direction has already been made ..
Please generate the next two sentences of the article | the first important step in experiments with fermionic atoms in optical lattices was the experimental observation of the fermi surface @xcite .
recent experiments with bosonic atoms directly observed correlated particle tunneling @xcite and superexchange @xcite , which are the basic mechanisms underlying quantum antiferromagnetism . |
3,289 | Suppose that you have an abstract for a scientific paper: in this sequel to our work on triply excited hollow resonances in three - electron atomic systems , a density functional theory ( dft)-based formalism is employed to investigate similar resonances in li - isoelectronic series ( z=410 ) .
a combination of the work - function - based local nonvariational exchange potential and the popular gradient plus laplacian included lee - yang - parr correlation energy functional is used .
the generalized pseudospectral method provides nonuniform and optimal spatial discretization of the radial kohn - sham equation to obtain self - consistent set of orbitals and densities in an efficient and accurate manner .
first , all the 8 n=2 intrashell states of b@xmath0 , n@xmath1 and f@xmath2 are presented , which are relatively less studied in the literature compared to the remaining 4 members .
then calculations are performed for the 8 @xmath3n@xmath4 ( 3@xmath5n@xmath56 ) hollow resonance series ; _ viz . , _
2s@xmath6ns @xmath6s@xmath7 , 2s@xmath6np @xmath6p@xmath8 , 2s@xmath6nd @xmath6d@xmath7 , 2s2pns @xmath9p@xmath8 , 2s2pnp @xmath9d@xmath7 , 2p@xmath6ns @xmath9p@xmath7 , 2p@xmath6np @xmath9d@xmath8 and 2p@xmath6ns @xmath6d@xmath7 , of all the 7 positive ions .
next , as an illustration , higher resonance positions of the 2s@xmath6ns @xmath6s@xmath7 series are calculated for all the ions with a maximum of n=25 .
the excitation energies calculated from this single - determinantal approach are in excellent agreement with the available literature data ( for the n=2 intrashell states the deviation is within 0.125% and excepting only one case , the same for the resonance series is well below 0.50% ) . with an increase in z ,
the deviations tend to decrease .
radial densities are also presented for some of the selected states . the only result available in the literature for the lower resonances ( corresponding to a maximum of n=17 )
have been reported very recently .
the n@xmath1016 ( @xmath11 for f@xmath2 ) resonances are examined here for the first time .....
And you have already written the first three sentences of the full article: with all three electrons residing in n@xmath122 shells leaving the k shell empty , the three - electron atomic system constitutes an interesting multi - excited atomic problem .
these are ideal for examining the delicate interelectronic correlation of three electrons under the influence of a nucleus , the well - known four - body coulombic problem .
a large majority of these triply excited hollow states are autoionizing and have found important practical applications in the field of high - temperature plasma diagnostics . ever since their first observation in an electron - helium scattering experiment by kuyatt _.
Please generate the next two sentences of the article | [ 1 ] and the same for li in a beam - foil experiment by bruch _ et al . _
[ 2,3 ] , many subsequent attempts were made to study the spectra of these challenging systems over the past three decades . |
3,290 | Suppose that you have an abstract for a scientific paper: we theoretically investigate the response of a superconducting film to line currents flowing in linear wires placed above the film , and we present analytic expressions for the magnetic - field and current distributions based on the critical state model .
the behavior of the superconducting film is characterized by the sheet - current density @xmath0 , whose magnitude can not exceed the critical value @xmath1 , where @xmath2 is the critical current density and @xmath3 is the thickness of the film .
when the transport current @xmath4 flowing in the wire is small enough , @xmath5 is smaller than @xmath1 and the magnetic field is shielded below the film .
when @xmath4 exceeds a threshold value @xmath6 , on the other hand , @xmath5 reaches @xmath1 and the magnetic field penetrates below the film .
we also calculate the ac response of the film when an ac transport current flows in the linear wires . .
And you have already written the first three sentences of the full article: the response of superconducting films to homogeneous applied magnetic fields is well understood , and analytic expressions for the distributions of the magnetic field and current density have been derived @xcite based on bean s critical state model .
@xcite when small current - carrying coils are placed near the surface to probe the local properties of superconducting films , the magnetic fields generated by the coils are inhomogeneous .
analytic expressions describing the response of superconducting films to small coils have been derived for the linear response regime , @xcite but in order to measure the local distribution of the critical current density @xmath2 in superconducting films , it is necessary to investigate the nonlinear response ..
Please generate the next two sentences of the article | @xcite numerical computations of the nonlinear response of superconducting films to the inhomogeneous magnetic fields arising from small coils have been carried out in refs . , but here we present analytic results for the nonlinear response to line currents above superconducting films . the procedure proposed by claassen _
et al . _ |
3,291 | Suppose that you have an abstract for a scientific paper: radial velocities from the 2.1 m telescope at mcdonald observatory supplemented with radial velocities from the coud feed telescope at kpno provide new precise orbits for the double - lined spectroscopic binaries rr lyn ( a3/a8/a6 ) , 12 boo ( f8iv ) , and hr 6169 ( a2v ) .
we derive orbital dimensions ( @xmath0 and @xmath1 ) and minimum masses ( @xmath2 and @xmath3 ) with accuracies of 0.06 to 0.9% .
the three systems , which have @xmath4 magnitudes of 5.54 , 4.83 , and 6.42 , respectively , are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the prospect , when our spectroscopic observations are complemented by interferometric observations , of fully - determined orbits , precise masses , and distances . in the case of rr lyn , which is also a detached eclipsing binary with a well - determined orbital inclination ( @xmath5 ; khaliullin et al .
2001 ) , we are able to determine the semimajor axis of the relative orbit , @xmath6r@xmath7 , primary and secondary radii of @xmath8r@xmath7 and @xmath9r@xmath7 , respectively ; and primary and secondary masses of @xmath10m@xmath7 and @xmath11m@xmath7 , respectively .
comparison of our new systemic velocity determination , @xmath12 km s@xmath13 , with the earlier one of @xcite , @xmath14 km s@xmath13 , shows no evidence of any change in the systemic velocity in the 40 years separating the two measurements , a null result that neither confirms nor contradicts the presence of the low - mass third component proposed by @xcite .
our spectroscopic orbit of 12 boo is more precise that that of @xcite but confirms their results about this system .
our analysis of hr 6169 has produced a major improvement in its orbital elements .
the minimum masses of the primary and secondary are 2.20 @xmath15 0.01 and 1.64 @xmath15 0.02 m@xmath16 , respectively .
although all three systems have eccentric orbits , the six components of the systems are either pseudosynchronously rotating or very nearly so . .
And you have already written the first three sentences of the full article: the current generation of ground - based interferometers , such as the palomar testbed interferometer ( pti ) @xcite , the naval prototype optical interferometer ( npoi)@xcite , the infrared optical telescope array ( iota3)@xcite , and the center for high angular resolution in astronomy ( chara ) array @xcite , is advancing stellar astronomy in a number of ways .
@xcite , for example , reviewed the state of optical and infrared interferometry .
one direction of progress is the increasing number of spectroscopic binaries that are being resolved as visual binaries ..
Please generate the next two sentences of the article | this allows the determination of their three - dimensional orbits and the derivation of accurate masses for the component stars and distances to the systems , distances that in many cases are more accurate than those from the _ hipparcos _ satellite . in recognition of this development
we have started a program to determine substantially improved spectroscopic orbits for bright , field spectroscopic binaries . |
3,292 | Suppose that you have an abstract for a scientific paper: a strong phase modulated coupling field leads to an amplitude modulation of a probe field in an electromagnetically induced transparency process .
time vs. detuning plots for different modulation frequencies reveals a transition between an adiabatic regime where a series of smooth pulses are created with a global phase dependent upon the detuning , and a non - adiabatic regime where a strong transient oscillating response is added to these pulses . in the extreme non - adiabatic regime , where the modulation frequency is higher than the transient decay time , a coherent interference pattern is revealed .
adding a magnetic field lifts the hyperfine level degeneracy , resulting in a separation of the original pulse to three pulses .
every pulse has now a different phase dependent upon the magnetic field causing an interference effect between the different magnetic level transients .
we explore the dynamics of the magnetic and non magnetic cases and show its resemblance to the landau - zener theory .
we also show that combining the global phase of the pulses with the transient interference allows for a wide magnetic sensing range without loosing the sensitivity of a single eit line .
electromagnetically induced transparency ( eit ) is a coherent process , where a strong coupling field creates a narrow transmission band in the probe spectrum in an otherwise fully absorptive medium @xcite .
the narrow linewidth of eit makes it suitable for applications in many fields such as extreme slow light , quantum storage devices , non linear optics and high sensitivity magnetic sensors . on the other hand
, this narrow linewidth directly limits the bandwidth of data that can be processed . a signal which has a broader bandwidth than the eit linewidth
will be absorbed spectrally , or will not be delayed in the time domain @xcite . in terms of magnetic sensing this means that although a very high sensitivity is possible using eit , it is a problem to probe with this sensitivity a broadband field .
a....
And you have already written the first three sentences of the full article: the ringing observed in fig .
2 is a manifestation of a non - adiabatic transition through the eit resonance .
landau - zener theory deals with this kind of transitions and gives analytic prediction to the population transfer between the levels . in the case of an eit in buffer gas.
Please generate the next two sentences of the article | the best way to describe the system is using the dressed state picture . taking the hamiltonian of the bare three levels under the rotating wave approximation where @xmath83 are the rabi frequencies of the coupling and the probe fields respectively ,
@xmath25 is a constant two photon detuning and @xmath24 is one photon detuning where in the case relevant to us is @xmath84 . in order to see the resemblance to the landau - zener case |
3,293 | Suppose that you have an abstract for a scientific paper: at the karlsruhe and tbingen 3.75mv van de graaff accelerators the thermonuclear @xmath0ti(n,@xmath1)@xmath2ti(5.8min ) cross section was measured by the fast cyclic activation technique via the 320.852 and 928.65kev @xmath1-ray lines of the @xmath2ti - decay .
metallic ti samples of natural isotopic composition and samples of tio@xmath3 enriched in @xmath0ti by 67.53% were irradiated between two gold foils which served as capture standards .
the capture cross - section was measured at the neutron energies 25 , 30 , 52 , and 145kev , respectively .
the direct capture cross section was determined to be [email protected] mbarn at 30kev .
we found evidence for a bound state s - wave resonance with an estimated radiative width of 0.34ev which destructively interfers with direct capture .
the strength of a suggested s - wave resonance at 146.8kev was determined .
the present data served to calculate , in addition to the directly measured maxwellian averaged capture cross sections at 25 and 52kev , an improved stellar @xmath0ti(n,@xmath1)@xmath2ti rate in the thermonuclear energy region from 1 to 250kev .
the new stellar rate leads at low temperatures to much higher values than the previously recommended rate , e.g. , at @xmath5kev the increase amounts to about 50% .
the new reaction rate therefore reduces the abundance of @xmath0ti due to s - processing in agb stars . .
And you have already written the first three sentences of the full article: for a long time it has been known that the solar - system abundances of elements heavier than iron have been produced by neutron - capture reactions @xcite . however , neutron capture is also of relevance for abundances of isotopes lighter than iron especially for neutron - rich isotopes , even though the bulk of these elements has been synthesized by charged - particle induced reactions .
the attempts to understand neutron - induced nucleosynthesis require as important ingredients the knowledge of neutron - capture rates .
the influence of shell effects on neutron capture is one of the most interesting aspects of neutron capture , especially since neutron capture in the vicinity of magic numbers is often a bottleneck in neutron - induced nucleosynthesis ..
Please generate the next two sentences of the article | this is the case also in neutron capture on neutron - rich isotopes close to the magic proton and neutron numbers @xmath6 and @xmath7 , i.e. , in the vicinity of the double - magic nucleus @xmath8ca . in particular , the reaction rate of neutron capture for ti - isotopes is of relevance for isotopic abundance anomalies in silicon carbide ( sic ) grains occurring in carbonecous meteorites @xcite .
contrary to most other solar system solids this type of grains has not been reprocessed an / or homogenized . |
3,294 | Suppose that you have an abstract for a scientific paper: graphite is an example of a layered material that can be bent to form fullerenes which promise important applications in electronic nanodevices .
the spheroidal geometry of a slightly elliptically deformed sphere was used as a possible approach to fullerenes .
we assumed that for a small deformation the eccentricity of the spheroid @xmath0 .
we are interested in the elliptically deformed fullerenes c@xmath1 as well as in c@xmath2 and its spherical generalizations like big c@xmath3 and c@xmath4 molecules .
the low - lying electronic levels are described by the dirac equation in ( 2 + 1 ) dimensions .
we show how a small deformation of spherical geometry evokes a shift of the electronic spectra compared to the sphere .
the flux of a monopole field was included inside the surface to describe the fullerenes .
both the electronic spectrum of spherical and the shift of spheroidal fullerenes were derived . .
And you have already written the first three sentences of the full article: fullerene molecules @xcite are carbon cages which appear in the vaporization of graphite .
one of their most beautiful features from a formal point of view is their geometric character and the exciting possibility of producing them in all sorts of geometric shapes having as building blocks sections of the honeycomb graphite lattice .
the most abundant of them is the most spherical @xmath5 molecule ..
Please generate the next two sentences of the article | the shape of the @xmath5 molecule is that of a soccer ball , consisting of 12 pentagons and 20 hexagons .
however , some fullerenes as @xmath6 are slightly elliptically deformed with the shape being more similar to an american football . |
3,295 | Suppose that you have an abstract for a scientific paper: spin-1/2 ising - heisenberg model with @xmath0 heisenberg pair interaction and two different ising quartic interactions is exactly solved with the help of the generalized star - square transformation , which establishes a precise mapping equivalence with the corresponding eight - vertex model on a square lattice generally satisfying baxter s zero - field ( symmetric ) condition .
the investigated model exhibits a remarkable weak - universal critical behavior with two marked wings of critical lines along which critical exponents vary continuously with the interaction parameters . both wings of critical lines merge together at a very special quantum critical point of the infinite order , which can be characterized through diverging critical exponents . the possibility of observing reentrant phase transitions in a close vicinity of the quantum critical point is related to a relative strength of the exchange anisotropy in the @xmath0 heisenberg pair interaction .
address = department of theoretical physics and astrophysics , faculty of science , + p. j. afrik university , park angelinum 9 , 040 01 koice , slovak republic address = department of applied mathematics , faculty of mechanical engineering , + technical university , letn 9 , 042 00 koice , slovak republic address = graduate school of mathematics , nagoya university , nagoya 464 - 8602 , japan .
And you have already written the first three sentences of the full article: exactly soluble quantum spin models belong to the most fascinating topics to deal with in the area of modern equilibrium statistical mechanics @xcite .
it should be pointed out , however , that quantum effects usually compete with a cooperative nature of spontaneous long - range ordering and thus , it is quite intricate to find an exactly solvable model that simultaneously exhibits both spontaneous long - range order as well as obvious macroscopic features of quantum origin . on the other hand , it is a competition between quantum and cooperative phenomena that is an essential ingredient for observing a quite remarkable and unexpected behavior of low - dimensional quantum spin models .
the hybrid ising - heisenberg models on decorated planar lattices , whose nodal sites are occupied by the classical ising spins and decorating sites by the quantum heisenberg ones , belong to the simplest rigorously solved quantum spin models that exhibit a spontaneous long - range ordering with apparent quantum manifestations ..
Please generate the next two sentences of the article | it is worthwhile to remark , moreover , that the ising - heisenberg planar models @xcite where a finite cluster of the heisenberg spins interacts with either two or three nodal ising spins are in principle tractable by the use of generalized decoration - iteration or star - triangle transformations @xcite , which establish a precise mapping equivalence between them and the spin-1/2 ising model on the corresponding undecorated planar lattice @xcite . among other matters , the exact solutions for this special class of the ising - heisenberg planar models might serve in evidence that these rigorously solvable models exhibit a strong - universal critical behavior , which can be characterized by critical exponents from the standard ising universality class .
contrary to this , the more interesting weak - universal behavior @xcite of the critical exponents has been recently announced for two ising - heisenberg planar models @xcite , where a finite cluster of the heisenberg spins interacts with four nodal ising spins . the spin-1/2 ising - heisenberg model with the pair @xmath0 heisenberg interaction and two quartic ising interactions |
3,296 | Suppose that you have an abstract for a scientific paper: we propose to combine the nonlinear scaling fields associated with the high - temperature ( ht ) fixed point , with those associated with the unstable fixed point , in order to calculate the susceptibility and other thermodynamic quantities .
the general strategy relies on simple linear relations between the ht scaling fields and the thermodynamic quantities , and the estimation of rg invariants formed out of the two sets of scaling fields .
this estimation requires convergent expansions in overlapping domains .
if , in addition , the initial values of the scaling fields associated with the unstable fixed point can be calculated from the temperature and the parameters appearing in the microscopic hamiltonian , one can estimate the critical amplitudes .
this strategy has been developed using dyson s hierarchical model where all the steps can be approximately implemented with good accuracy .
we show numerically that for this model ( and a simplified version of it ) , the required overlap apparently occurs , allowing an accurate determination of the critical amplitudes .
keywords : renormalization group , scaling fields , high - temperature expansion , hierarchical model , normal forms , critical amplitudes , crossover . .
And you have already written the first three sentences of the full article: it is well - known that the magnetic susceptibility of a spin model near its critical temperature can be parametrized as @xmath0 in this expression , the exponents @xmath1 and @xmath2 are universal and can be obtained from the calculation of the eigenvalues of the linearized renormalization group ( rg ) transformation . on the other hand , the critical amplitudes @xmath3 are functions of the microscopic details of the theory .
one can find universal relations @xcite among these amplitudes and the ones associated with other thermodynamic quantities , however these relations do not fix completely the amplitudes . in the end , if we want a quantitative estimate of a particular amplitude , we need to perform a calculation which requires a knowledge of many details of the rg flows .
such a calculation is in general a difficult , nonlinear , multivariable problem . in this article.
Please generate the next two sentences of the article | we propose a general strategy based on the construction of nonlinear scaling fields associated with _
several _ fixed points , to calculate the critical amplitudes , and we demonstrate its feasibility in the case of dyson s hierarchical model . a common strategy in problems involving nonlinear flows near a singular point , is to construct a new system of coordinates for which the governing equations become linear . |
3,297 | Suppose that you have an abstract for a scientific paper: tev emission from bl lacertae ( bl ) objects is commonly modeled as synchrotron - self compton ( ssc ) radiation from relativistically moving homogeneous plasma blobs . in the context of these models , the blob lorentz factors needed to reproduce the corrected for absorption by the diffuse ir background ( dirb ) tev emission are large ( @xmath0 ) .
the main reason for this is that stronger beaming eases the problem of the lack of @xmath1 ir - uv synchrotron seed photons needed to produce the de - absorbed @xmath2 few tev peak of the spectral energy distribution ( sed ) .
however , such high doppler factors are in strong disagreement with the unified scheme , according to which bls are fr i radio galaxies with their jets closely aligned to the line of sight . here , motivated by the detection of sub - luminal velocities in the sub - pc scale jets of the best studied tev blazars , mkn 421 and mkn 501 , we examine the possibility that the relativistic flows in the tev bls decelerate . in this case , the problem of the missing seed photons is solved because of upstream compton ( uc ) scattering , a process in which the upstream energetic electrons from the fast base of the flow ` see ' the synchrotron seed photons produced in the slow part of the flow relativistically beamed . modest lorentz factors ( @xmath3 ) , decelerating down to values compatible with the recent radio interferometric observations , reproduce the @xmath2 few tev peak energy of these sources .
furthermore , such decelerating flows are shown to be in agreement with the bl - fr i unification , naturally reproducing the observed bl / fr i broad band luminosity ratios . .
And you have already written the first three sentences of the full article: there is a small but growing family of blazars detected at tev energies .
these belong exclusively to the class of high peak frequency bls , i.e. blazars whose synchrotron component peaks at x - ray energies .
tev emitting bls are of particular interest because of the possibility of absorption of their tev emission by the dirb @xcite ..
Please generate the next two sentences of the article | study of their spectra in the tev range can be used to probe the properties of dirb as a function of redshift @xmath4 @xcite , given that the magnitude of absorption depends on the redshift of the source and the , still elusive , dirb spectrum @xcite .
the absorption of the tev photons of this blazar class suggests that both the intrinsic peak photon energy @xmath5 and peak luminosity @xmath6 of the high energy ( tev ) component are higher than those observed . |
3,298 | Suppose that you have an abstract for a scientific paper: the deployment of deepcore array significantly lowers icecube s energy threshold to about @xmath0 gev and enhances the sensitivity of detecting neutrinos from annihilations and decays of light dark matter . to match this experimental development , we calculate the track event rate in deepcore array due to neutrino flux produced by annihilations and decays of galactic dark matter .
we also calculate the background event rate due to atmospheric neutrino flux for evaluating the sensitivity of deepcore array to galactic dark matter signatures . unlike previous approaches , which set the energy threshold for track events at around @xmath1 gev ( this choice avoids the necessity of including oscillation effect in the estimation of atmospheric background event rate ) , we have set the energy threshold at @xmath0 gev to take the full advantage of deepcore array .
we compare our calculated sensitivity with those obtained by setting the threshold energy at @xmath1 gev .
we conclude that our proposed threshold energy significantly improves the sensitivity of deepcore array to the dark matter signature for @xmath2 gev in the annihilation scenario and @xmath3 gev in the decay scenario .
= = = = = = = = = ==================== = ======= .
And you have already written the first three sentences of the full article: many astrophysical observations have confirmed the existence of dark matter ( dm ) , which contributes to roughly @xmath4 of the energy density of the universe . among many proposed dm candidates , weakly interacting massive particles ( wimps ) @xcite are popular proposals since they are theoretically well motivated and also capable of producing the correct relic density .
wimps could annihilate or decay into particles such as electrons , positrons , protons , antiprotons , photons , and neutrinos .
it is possible to establish the wimp signature through detecting these particles @xcite ..
Please generate the next two sentences of the article | research activities on wimps have been boosted recently in efforts of explaining the observed anomalous positron excess in the data of pamela @xcite and positron plus electron excess in the data of fermi @xcite . to account for spectral shapes observed by these experiments
, wimps must annihilate or decay mostly into leptons in order to avoid the overproduction of antiprotons . |
3,299 | Suppose that you have an abstract for a scientific paper: a dispersive medium becomes entangled with zero - point fluctuations in the vacuum .
we consider an arbitrary array of material bodies weakly interacting with a quantum field and compute the quantum mutual information between them .
it is shown that the mutual information in @xmath0 dimensions can be mapped to classical thermodynamic entropy in @xmath1 dimensions . as a specific example
, we compute the mutual information both analytically and numerically for a range of separation distances between two bodies in @xmath2 dimensions and find a logarithmic correction to the area law at short separations .
a key advantage of our method is that it allows the strong subadditivity property to be easily verified .
entanglement as a purely quantum phenomenon has become a central subject in many fields , ranging from high - energy physics to many - body systems and quantum information . in particular , the characteristic entropy associated with entanglement
has proved a powerful tool for describing the quantum nature of a system @xcite as well as for quantifying resources available for quantum computation @xcite .
inspired by formal similarities with thermodynamics , parallels between quantum and classical notions of entropy have been suggested in the literature @xcite .
while many studies of entanglement entropy have considered geometrical regions in vacuum @xcite or domains in many - body systems @xcite , rapid advances in quantum computation and atomic and optical physics have prompted studies of entanglement between atoms and light @xcite .
although most studies have addressed the case of one or a few bodies , recent attention has turned to the problem of quantifying the entanglement of a medium interacting with a quantum field , both described by ( infinitely ) many modes . in particular , ref .
@xcite took key first steps in this direction , but simple conceptual pictures and efficient computational tools have remained elusive . in this letter , we consider two or more dispersive....
And you have already written the first three sentences of the full article: computing the covariance matrix @xmath48 requires two - point functions . the latter should be computed by inverting the operator ( cf .
( 3 ) of the main text ) @xmath116 defined on the support of the media @xmath117 . to invert this operator
, we will treat the second term perturbatively justified in the weak - coupling limit where @xmath118 with @xmath39 the linear size of the media ..
Please generate the next two sentences of the article | therefore , to the first order , we find @xmath119 the two - point functions @xmath120 and @xmath121 defined in the manuscript can be computed accordingly .
the field correlation function reads @xmath122 where the factor of 2 in the first equality comes from the restriction to @xmath123 . |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.