id
int64 0
203k
| input
stringlengths 66
4.29k
| output
stringlengths 0
3.83k
|
|---|---|---|
10,700 |
Suppose that you have an abstract for a scientific paper: in this paper , we study simplicial complexes whose stanley reisner rings are almost gorenstein and have @xmath0-invariant zero .
we call such a simplicial complex an almost gorenstein * simplicial complex . to study the almost gorenstein * property
, we introduce a new class of simplicial complexes which we call uniformly cohen macaulay simplicial complexes .
a @xmath1-dimensional simplicial complex @xmath2 is said to be uniformly cohen
macaulay if it is cohen macaulay and , for any facet @xmath3 of @xmath2 , the simplicial complex @xmath4 is cohen macaulay of dimension @xmath1 .
we investigate fundamental algebraic , combinatorial and topological properties of these simplicial complexes , and show that almost gorenstein * simplicial complexes must be uniformly cohen macaulay . by using this fact ,
we show that every almost gorenstein * simplicial complex can be decomposed into those of having one dimensional top homology .
also , we give a combinatorial criterion of the almost gorenstein * property for simplicial complexes of dimension @xmath5 . .
And you have already written the first three sentences of the full article: in this paper , we study the almost gorenstein property of stanley reisner rings .
let @xmath6 be a field , @xmath7 a graded @xmath6-algebra of krull dimension @xmath8 , and let @xmath9 be its canonical module .
the algebra @xmath10 is said to be _ almost gorenstein _.
Please generate the next two sentences of the article
|
if @xmath10 is cohen macaulay and there is a short exact sequence of degree @xmath11 @xmath12 such that the multiplicity of @xmath13 is equal to the number of minimal generators of @xmath13 , where @xmath14 is the _
@xmath0-invariant _ of @xmath10 and where @xmath15 denotes the graded module @xmath16 with grading shifted by degree @xmath17 .
|
10,701 |
Suppose that you have an abstract for a scientific paper: using a new technique we have determined a value for the constant of proportionality between submillimetre ( submm ) emission and dust mass , the dust mass absorption coefficient ( @xmath0 ) at @xmath1 m .
our method has an advantage over previous methods in that we avoid assumptions about the properties of dust in the interstellar medium .
our only assumption is that the fraction of metals incorporated in the dust ( @xmath2 ) in galaxies is a universal constant . to implement our method we require objects that have submillimetre and far - infrared ( fir ) flux measurements as well as gas mass and metallicity estimates .
we present data for all the galaxies with suitable measurements , including new submm maps for five galaxies .
we find @xmath3 .
we have also been able to use our sample to investigate our assumption that @xmath2 is a universal constant .
we find no evidence that @xmath2 is different for dwarf and giant galaxies and show that the scatter in @xmath2 from galaxy to galaxy is apparently quite small .
dust , extinction - galaxies : dwarf - galaxies : abundances - galaxies : evolution .
And you have already written the first three sentences of the full article: measurements of the depletion of heavy elements , relative to the solar abundances , along the line of sight to the stars show that about @xmath4 of the metals in the galaxy is bound up in dust grains ( whittet 1992 ) .
this raises the questions : is this fraction the same for every galaxy ?
what are the processes that so efficiently lock metals into dust grains ?.
Please generate the next two sentences of the article
|
although the presence of dust manifests itself in a multitude of ways - extinction , reddening , the polarisation of starlight , to name but three - the best way , in principle , to estimate the mass of dust in a galaxy is from the submm flux density .
the advantages of this are that ( a ) the emission from dust is optically thin and ( b ) the emission depends mainly on the mass of dust and is only weakly dependent on the temperature of the dust . the practical obstacle to making the full use of this technique has been the difficulty of estimating the constant of proportionality between the emission and the mass of dust , the mass - extinction or the mass - absorption coefficient .
|
10,702 |
Suppose that you have an abstract for a scientific paper: we perform a deductive study of accelerating universe and focus on the importance of variable time - dependent @xmath0 in the einstein s field equations under the phenomenological assumption , @xmath1 for the full physical range of @xmath2 .
the relevance of variable @xmath0 with regard to various key issues like dark matter , dark energy , geometry of the field , age of the universe , deceleration parameter and barotropic equation of state has been trivially addressed .
the deceleration parameter and the barotropic equation of state parameter obey a straight line relationship for a flat universe described by friedmann and raychaudhuri equations .
both the parameters are found identical for @xmath3 .
example.eps gsave newpath 20 20 moveto 20 220 lineto 220 220 lineto 220 20 lineto closepath 2 setlinewidth gsave .4 setgray fill grestore stroke grestore .
And you have already written the first three sentences of the full article: to account for the vast majority of mass in the observable universe and to explain its accelerated expansion , the physical cosmology of today requires two outstanding concepts : ( i ) the matter which does not interact with the electromagnetic force - _ dark matter _ , and ( ii )
the hypothetical energy that tends to increase the rate of expansion of the universe - _ dark energy_. zwicky @xcite , using virial theorem , had suggested for a possible existence of dark matter long ago , which was later on supported by the studies of rotation curves @xcite , gravitational lensing @xcite , cmb anisotropy @xcite and bullet clusters @xcite .
the advent of inflationary theory @xcite led to the convincing belief that @xmath4 of matter content of the universe is hidden mass constituted by @xmath5 dark matter and @xmath6 dark energy @xcite ..
Please generate the next two sentences of the article
|
dark matter plays a central role in early universe during structure formation and galaxy evolution because of its nature to clump in sub - megaparsec scales .
cobe and cmb experiments suggest that baryonic dark matter is not more than a small fraction of the total dark matter present in the universe @xcite .
|
10,703 |
Suppose that you have an abstract for a scientific paper: we investigated a scenario in which m31 could be the remnant of a major merger and at the origin of the lmc .
galaxy merger simulations were run in order to reproduce some m31 properties .
we succeeded in reproducing some of the most important m31 large - scale features like the thick disk or the polar ring , and gave a possible explanation for the formation of the giant stream .
we also found that the lmc could be expelled by this high energetic phenomenon . .
And you have already written the first three sentences of the full article: several observations suggest that the andromeda galaxy could be the remnant of a major merger .
m31 has a robustly classical and not pseudo bulge , which is an argument in favor of such a merger scenario , according to @xcite .
@xcite also argued that due to the high metallicity of the m31 halo and the @xmath0 luminosity profile of the bulge , m31 is likely the result of a merger of two massive metal - rich ancestors ..
Please generate the next two sentences of the article
|
conversely , there are several difficulties in reproducing the giant stream by a recent minor merger , according to @xcite . for instance
, they do not succeed in reproducing the metal - poor ( [ fe / h]@xmath1 ) stellar population .
|
10,704 |
Suppose that you have an abstract for a scientific paper: the rare decay @xmath0 can occur only via annihilation diagrams in the standard model .
we calculate the branching ratio in perturbative qcd approach based on @xmath1 factorization theorem .
we found that the branching ratio of this decay is about of order @xmath2 , which may be sensitive to new physics .
( 0,0)(0,0 ) ( 340,420)bihep - th-2003 - 19 .
And you have already written the first three sentences of the full article: rare @xmath3 decays are very important in particle physics , because they are important windows in testing the standard model ( sm ) and they are sensitive to new physics . as a rather simple method ,
factorization approach is accepted , because it explained many decay branching ratios successfully @xcite .
recently , some efforts have been made to improve their theoretical application ..
Please generate the next two sentences of the article
|
one of these methods is the perturbative qcd approach ( pqcd ) , in which many rare branching ratios such as @xmath4 @xcite , @xmath5 @xcite , @xmath6 @xcite were predicted . in recent calculations , @xmath7 ,
@xmath8 have been analyzed in the pqcd approach @xcite , leaving @xmath9 not calculated . in decay @xmath10 , none of quarks in the final states is the same as one of the @xmath3 meson .
|
10,705 |
Suppose that you have an abstract for a scientific paper: experimental prospects for studying high - energy photon - photon and photon - proton interactions at the lhc are discussed . assuming a typical lhc multipurpose detector , various signals and their irreducible backgrounds are presented after applying acceptance cuts .
selection strategies based on photon interaction tagging techniques are presented .
prospects are discussed for the higgs boson search , detection of susy particles and of anomalous quartic gauge couplings , as well as for the top quark physics . .
And you have already written the first three sentences of the full article: r0.42 a significant fraction of @xmath0 collisions at the lhc will involve ( quasi - real ) photon interactions , at center - of - mass ( c.m.s ) energies well beyond the electroweak energy scale .
hence , the lhc can to some extend be considered as a high - energy photon - photon or photon - proton collider .
the equivalent photon approximation ( epa ) can be successfully used to describe the majority of processes involving photon exchange , provided that the amplitude of a given process can be factorised into the photon exchange and interaction parts @xcite . the photon - photon and photon - proton cross sections , @xmath1 and @xmath2 , must be convoluted with the photon spectra @xmath3 to obtain the @xmath0 cross sections ..
Please generate the next two sentences of the article
|
this paper considers the low pile - up conditions available at start - up and focuses on the irreducible backgrounds to the presented analyses .
deeper studies involving inclusive background will be the object of later communications .
|
10,706 |
Suppose that you have an abstract for a scientific paper: in an attempt to describe cork - pulling , we model a cork as an incompressible rubber - like material and consider that it is subject to a helical shear deformation superimposed onto a shrink fit and a simple torsion . it turns out that this deformation field provides an insight into the possible appearance of secondary deformation fields for special classes of materials .
we also find that these latent deformation fields are woken up by normal stress differences .
we present some explicit examples based on the neo - hookean , the generalized neo - hookean , and the mooney
rivlin forms of the strain - energy density . using the simple exact solution found in the neo - hookean case , we conjecture that it is advantageous to accompany the usual vertical axial force by a twisting moment , in order to extrude a cork from the neck of a bottle efficiently
. then we analyse departures from the neo - hookean behaviour by exact and by asymptotic analyses . in that process
we are able to give an elegant and analytic example of secondary ( or latent ) deformations in the framework of nonlinear elasticity . .
And you have already written the first three sentences of the full article: rubbers and elastomers are highly deformable solids which have the remarkable property of preserving their volume through any deformation .
this permanent isochoricity can be incorporated into the equations of continuum mechanics through the concept of an _ internal constraint _
, here the constraint of _ incompressibility_. mathematically , the formulation of the constraint of incompressibility has led to the discovery of several exact solutions in isotropic finite elasticity , most notably to the controllable or universal solutions of rivlin and co - workers ( see for example rivlin ( 1948 ) ) . subsequently , ericksen ( 1954 ) examined the problem of finding all such solutions ..
Please generate the next two sentences of the article
|
he found that there are no controllable finite deformations in isotropic _ compressible _ elasticity , except for homogeneous deformations ( ericksen 1955 ) .
the impact of that result on the theory of nonlinear elasticity was quite important and long - lasting , and for many years a palpable pessimism reigned about the possibility of finding exact solutions at all for compressible elastic materials .
|
10,707 |
Suppose that you have an abstract for a scientific paper: existence of the @xmath0-dibaryon in the flavor @xmath1 symmetric limit is studied by full qcd simulations on the lattice , in the approach recently developed for the baryon - baryon ( @xmath2 ) interactions .
potential of the flavor - singlet @xmath2 channel is derived from the nambu - bethe - salpeter wave function , and a bound @xmath0-dibaryon is discovered from it , with the binding energy of 2050 mev for the pseudo - scalar meson mass of 4691171 mev .
address = nihon university , college of bioresource sciences , kanagawa 1866 , japan .
And you have already written the first three sentences of the full article: the @xmath0-dibaryon , predicted by r. l. jaffe in 34 years ago @xcite .
is one of most famous candidates of exotic - hadron .
this prediction was based on the observations that the quark exclusion can be completely avoided due to the essentially flavor - singlet(@xmath3 ) nature of @xmath0-dibaryon , together with the large attraction from one - gluon - exchange interaction between quarks suggested in the quark model @xcite ..
Please generate the next two sentences of the article
|
search for the @xmath0-dibaryon is one of the most challenging theoretical and experimental problems in the physics of strong interaction and quantum chromodynamics ( qcd ) .
still it is not clear whether there exists the @xmath0-dibaryon in nature .
|
10,708 |
Suppose that you have an abstract for a scientific paper: we study the coupling between majorana bound states(cmbs ) mediated by a topologically trivial chain in the absence / presence of pairing couplings at the boundaries .
both situations of short - range and long - range interactions in the chain are considered .
our results show that cmbs can be enhanced by the pairing coupling and long - range interaction in the trivial chain . with a driving field applied to the chain
, we calculate the dependence of cmbs on the frequency and amplitude of the driving field .
discussion on the application of the tunable cmbs in quantum computation is made . .
And you have already written the first three sentences of the full article: topological quantum computation@xcite is immune to certain types of noise .
it has attracted much attention since it was proposed and becomes active again in recent years due to the progress in experiments .
the gates used for quantum computation can be conducted by creating quasi - particles , braiding them and measuring their states ..
Please generate the next two sentences of the article
|
two well - known types of quasi - particles are fibonacci anyons and ising anyons ( majorana bound states ) .
the former are capable of offering universal topological quantum computation , while the latter can not form an universal set of gates by braiding operation only .
|
10,709 |
Suppose that you have an abstract for a scientific paper: the evolution of agn in groups and clusters provides important information about how their black holes grow , the extent to which galaxies and black holes coevolve in dense environments , and has implications for feedback in the local universe and at the epoch of cluster assembly .
i describe new observations and analysis that demonstrates that the agn fraction in clusters increases by a factor of eight from the local universe to @xmath0 and that this evolution is consistent with the evolution of star - forming galaxies in clusters .
the cluster agn fraction remains approximately an order of magnitude below the field agn fraction over this entire range , while a preliminary analysis of groups indicates that they too undergo substantial evolution .
address = department of astronomy and center for cosmology and astroparticle physics , + the ohio state university , columbus , oh , usa .
And you have already written the first three sentences of the full article: many studies over the past decade have presented strong evidence for the coevolution of black holes and galaxies based on samples dominated by the low - density field ( e.g. * ? ? ?
* ; * ? ? ?
* and references therein ) ..
Please generate the next two sentences of the article
|
it is interesting to determine if similar coevolution between agn and galaxies is present in groups and clusters because the physical processes that drive galaxy evolution , such as the available cold gas to fuel star formation and black hole growth , are substantially different from the field .
in addition , agn in groups and clusters at low - redshift appear to play the critical role in maintaining the temperature of their hot atmospheres ( e.g. * ? ? ? * ) , while agn heating at the epoch of cluster assembly remains a viable explanation for the minimum entropy level in the intracluster medium .
|
10,710 |
Suppose that you have an abstract for a scientific paper: the study of active region tilt angles and their variations in different time scales plays an important role in revealing the subsurface dynamics of magnetic flux ropes and in understanding the dynamo mechanism . in order to reveal the exact characteristics of tilt angles ,
precise long - term tilt angle data bases are needed .
however , there are only a few different data sets at present , which are difficult to be compared and cross - calibrate because of their substantial deviations . in this paper , we describe new tilt angle data bases derived from the debrecen photoheliographic data ( @xmath0 ) ( 1974 ) and from the soho / mdi - debrecen data ( @xmath1 ) ( 1996 - 2010 ) sunspot catalogues .
we compare them with the traditional sunspot group tilt angle data bases of mount wilson observatory ( 1917 - 85 ) and kodaikanal solar observatory ( 1906 - 87 ) and we analyse the deviations .
various methods and filters are investigated which may improve the sample of data and may help deriving better results based on combined data . as a demonstration of the enhanced quality of the improved data set a refined diagram of the joy s law
is presented .
[ firstpage ] ( sun : ) sunspots methods : data analysis . .
And you have already written the first three sentences of the full article: it has been known for a long time that the line connecting the leading and following portions of a bipolar sunspot group usually tilts with respect to the solar equator @xcite .
the tilt angle has been regarded as an important parameter of the magnetic field since the publication of the solar dynamo models by @xcite and @xcite .
the longest available tilt angle data bases are derived from white - light photographic observations taken at mount wilson observatory ( @xmath2 ) in 1917 - 1985 and kodaikanal solar observatory ( @xmath3 ) in 1906 - 1987 @xcite ..
Please generate the next two sentences of the article
|
the magnetograms available since 1974 also allow the study of tilt angle of active regions @xcite .
numerous characteristics of tilt angles and their changes have been investigated based on these data bases ( e. g. @xcite ) .
|
10,711 |
Suppose that you have an abstract for a scientific paper: in this paper , the classical schrdinger equation , which allows the study of classical dynamics in terms of wave functions , is analyzed theoretically and numerically .
first , departing from classical ( newtonian ) mechanics , and assuming an additional single - valued condition for the hamiltons principal function , the classical schrdinger equation is obtained .
this additional assumption implies inherent non - classical features on the description of the dynamics obtained from the classical schrdinger equation : the trajectories do not cross in the configuration space .
second , departing from bohmian mechanics and invoking the quantum - to - classical transition , the classical schrdinger equation is obtained in a natural way for the center of mass of a quantum system with a large number of identical particles .
this quantum development imposes the condition of dealing with a narrow wave packet , which implicitly avoids the non - classical features mentioned above .
we illustrate all the above points with numerical simulations of the classical and quantum schrdinger equations for different systems . .
And you have already written the first three sentences of the full article: since the beginning of quantum theory a century ago , the study of the frontier between classical and quantum mechanics has been a constant topic of debate @xcite . in our opinion ,
the difficulties in the progress of this debate are also due to the deep - rooted use of different languages in classical and quantum mechanics : while classical system are usually described using trajectories @xcite , quantum descriptions involve wave functions @xcite .
these two languages are so different that it is hard ( and sometimes misleading ) to directly compare trajectories and wave functions . but.
Please generate the next two sentences of the article
|
despite its pervasiveness , this clash of languages can be avoided by using other readily available formulations , where both theories can be compared on an equal footing .
for instance , bohmian mechanics provides a deterministic description of quantum systems where particles have definite positions , and their trajectories are _ choreographed _ by the wave function @xcite . on the other hand , ensembles of classical particles can be described in terms of waves using the hamilton
|
10,712 |
Suppose that you have an abstract for a scientific paper: we derive equations for fluid dynamics from a non - extensive boltzmann transport equation consistent with tsallis non - extensive entropy formula .
we evaluate transport coefficients employing the relaxation time approximation and investigate non - extensive effects in leading order dissipative phenomena at relativistic energies , like heat conductivity , shear and bulk viscosity . .
And you have already written the first three sentences of the full article: the transport properties of matter at extreme high temperature and energy density , well proved in high energy accelerator experiments at the relativistic heavy - ion collider ( rhic ) and at the large hadron collider ( lhc ) , raised some fundamental questions related to the smallest distance scale in physics .
theories , motivated by conformal field theory and higher dimensional dual gravity , in fact predicted a lower limit for the shear viscosity over entropy density ratio being around @xmath0 in natural units @xcite .
although this limitation can be overcome in more sophisticated , nonlinear dual gravity models @xcite or other approaches @xcite , the actual calculation @xcite and measurement of the viscosity and related properties of elementary matter remained in the focus of research interest ..
Please generate the next two sentences of the article
|
the more , because the scientific evaluation of experimental signals , extracted from analyses of particle spectra and correlations , can be interpreted in terms of thermal concepts only if our knowledge about the material quality of a ( strongly ) interacting quark - gluon plasma is well established @xcite . besides the interpretation of temperature @xcite
, the whole hydrodynamical and statistical approach relies on our basic assumptions about the equation of state ( eos ) and the dissipative capacities of this new stage of strongly interacting matter @xcite .
|
10,713 |
Suppose that you have an abstract for a scientific paper: we study the stability of capillary hypersurfaces in a unit euclidean ball .
it is proved that if the mass center of the generalized body enclosed by the immersed capillary hypersurface and the wetted part of the sphere is located at the origin , then the hypersurface is unstable .
an immediate result is that all known examples except the totally geodesic ones and spherical caps are unstable . .
And you have already written the first three sentences of the full article: capillarity is an important physical phenomena , which occurs when two different materials contact and do not mix . given a container @xmath0 with an incompressible liquid drop @xmath1 in it , the interface of the liquid and
the air is a capillary surface @xmath2 . in absence of gravity ,
the interface @xmath2 is of constant mean curvature and the contact angle of @xmath2 to the boundary @xmath3 is constant ..
Please generate the next two sentences of the article
|
one should compare this setting with soap bubble ( resp .
soap film ) , where the surface has no boundary ( resp .
|
10,714 |
Suppose that you have an abstract for a scientific paper: we will discuss selected physical effects of spacetime geometry fluctuations , especially the operational signatures of geometry fluctuations and their effects on black hole horizons .
the operational signatures which we discuss involve the effects of the fluctuations on images , and include luminosity variations , spectral line broadening and angular blurring .
our main interest will be in black hole horizon fluctuations , especially horizon fluctuations which have been enhanced above the vacuum level by gravitons or matter in squeezed states .
we investigate whether these fluctuations can alter the thermal character of a black hole .
we find that this thermal character is remarkably robust , and that hawking s original derivation using transplanckian modes does not seem to be sensitive even to enhanced horizon fluctuations . .
And you have already written the first three sentences of the full article: in this paper , we will discuss selected aspects of the effects of quantum spacetime geometry fluctuations , using the riemann tensor correlation function as our basic tool .
it is first useful to make a distinction between active fluctuations , which arise from the dynamical degrees of freedom of gravity itself , and passive fluctuations , which are driven by quantum stress tensor fluctuations of matter fields . in general , both types of fluctuations are present .
we will be concerned with the case where the fluctuations around a classical background spacetime are small , so we can consider each type separately and add their effects ..
Please generate the next two sentences of the article
|
of course , a full treatment of active fluctuations would require a more complete theory of quantum gravity than currently exists , but we restrict our attention to quantized linear perturbations of the background spacetime .
various aspects of spacetime geometry fluctuations have been discussed by several authors in recent years , for example @xcite . in particular ,
|
10,715 |
Suppose that you have an abstract for a scientific paper: in this paper , we limit the stellar content of 13 high - velocity clouds ( hvcs ; including 1 compact hvc ) using the detection limits of a new survey for resolved milky way satellite galaxies in the sloan digital sky survey early data release ( edr ) .
our analysis is sensitive to stellar associations within the virial radius of the milky way that are up to 50@xmath0 fainter than the faintest known milky way satellites .
statistically , we find no stellar overdensity associated with any of the clouds .
these non - detections suggest lower limits of m@xmath1/@xmath2 that range between @xmath3 and @xmath4 , assuming cloud distances of 50 and 300 kpc and using fiducial optical scale lengths of 3@xmath5 and 7@xmath5 .
we explore the implication of these non - detections on the origin of the hvcs . .
And you have already written the first three sentences of the full article: for decades , astronomers have struggled to determine the properties of the high - velocity clouds ( hvcs ) , a population of objects identified by 21 cm hi emission with velocities inconsistent with galactic rotation .
recent improvements in available radio survey data ( e.g. the hi parkes all - sky survey and the leiden dwingeloo survey ; barnes et al . 2001 and hartmann & burton 1997 respectively ) and uv instrumentation ( e.g. stis and fuse ) , have substantially increased our understanding of these numerous ( @xmath6 2000 in the south alone , putman et al .
2002 ) clouds ..
Please generate the next two sentences of the article
|
however , the origin of the vast majority of the hvc population has remained controversial .
several explanations for their presence have been suggested , including : a galactic fountain ; tidal or ram pressure stripping from dwarf galaxies ; and low mass dark matter halos predicted by currently favored cosmologies but not observed in optical surveys ( blitz et al .
|
10,716 |
Suppose that you have an abstract for a scientific paper: we describe the state of analysis of the mipp experiment , its plans to upgrade the experiment and the impact such an upgraded experiment will have on hypernuclear physics . .
And you have already written the first three sentences of the full article: the upgraded mipp experiment is designed to measure the properties of strong interaction spectra form beams @xmath0 and @xmath1 for momenta ranging from 1 gev / c to 120 gev / c .
the layout of the apparatus in the data taken so far can be seen in figure [ layout ] .
the centerpiece of the experiment is the time projection chamber , which is followed by the time of flight counter , a multi - cell cerenkov detector and the rich detector ..
Please generate the next two sentences of the article
|
the tpc can identify charged particles with momenta less than 1 gev / c using de / dx , the time of flight will identify particles below approximately 2 gev / c , the multi - cell cerenkov detector is operational from 2.5 gev / c to 14 gev / c and the rich detector can identify particles up to 120 gevc . following
this is an em and hadronic calorimeter capable of detecting forward going neutrons and photons .
|
10,717 |
Suppose that you have an abstract for a scientific paper: we demonstrate purcell - like enhancement of rayleigh scattering into a single optical mode of a fabry - perot resonator for several thermal atomic and molecular gases .
the light is detuned by more than an octave , in this case by hundreds of nanometers , from any optical transition , making particle excitation and spontaneous emission negligible .
the enhancement of light scattering into the resonator is explained quantitatively as an interference effect of light waves emitted by a classical driven dipole oscillator .
applications of our method include the sensitive , non - destructive in - situ detection of ultracold molecules . .
And you have already written the first three sentences of the full article: light scattering lies at the heart of optics .
to harvest weak signals , collecting a large fraction of scattered light is essential .
this is most directly achieved using a lens with a large numerical aperture ..
Please generate the next two sentences of the article
|
an alternative and more powerful approach , however , is to couple the scattering object to an optical resonator , even if the relevant light mode covers only a small solid angle .
the potential offered by the resonator comes from the purcell effect @xcite , generally associated with the enhanced spontaneous emission rate of an excited particle in electromagnetically confined space .
|
10,718 |
Suppose that you have an abstract for a scientific paper: an integer additive set - indexer is defined as an injective function @xmath0 such that the induced function @xmath1 defined by @xmath2 is also injective .
an iasi @xmath3 is said to be a weak iasi if @xmath4 for all @xmath5 .
a graph which admits a weak iasi may be called a weak iasi graph .
the set - indexing number of an element of a graph @xmath6 , a vertex or an edge , is the cardinality of its set - labels .
the sparing number of a graph @xmath6 is the minimum number of edges with singleton set - labels , required for a graph @xmath6 to admit a weak iasi . in this paper
, we study the sparing number of certain graphs and the relation of sparing number with some other parameters like matching number , chromatic number , covering number , independence number etc . *
key words * : weak integer additive set - indexers , mono - indexed elements of a graph , sparing number of a graph . +
* ams subject classification : 05c78 * .
And you have already written the first three sentences of the full article: for all terms and definitions , not defined specifically in this paper , we refer to @xcite . unless mentioned otherwise , all graphs considered here are simple , finite and have no isolated vertices .
let @xmath7 denote the set of all non - negative integers . for all @xmath8 , the sum of these sets
is denoted by @xmath9 and is defined by @xmath10 ..
Please generate the next two sentences of the article
|
the set @xmath9 is called the sumset of the sets @xmath11 and @xmath12 . an _ integer additive set - indexer _ ( iasi , in short ) is defined in @xcite as an injective function @xmath0 such that the induced function @xmath1 defined by @xmath2 is also injective .
the cardinality of the labeling set of an element ( vertex or edge ) of a graph @xmath6 is called the _ set - indexing number _ of that element .
|
10,719 |
Suppose that you have an abstract for a scientific paper: we present new evidence of x - ray absorption variability on time scales from a few hours to a few days for several nearby bright agns .
the observed n@xmath0 variations imply that the x - ray absorber is made of clouds eclipsing the x - ray source with velocities in excess of 10@xmath1 km s@xmath2 , and densities , sizes and distances from the central black hole typical of blr clouds .
we conclude that the variable x - ray absorption is due to the same clouds emitting the broad emission lines in the optical / uv .
we then concentrate on the two highest signal - to - noise spectra of eclipses , discovered in two long observations of ngc 1365 and mrk 766 , and we show that the obscuring clouds have a cometary shape , with a high density head followed by a tail with decreasing @xmath3 .
our results show that x - ray time resolved spectroscopy can be a powerful way to directly measure the physical and geometrical properties of blr clouds . .
And you have already written the first three sentences of the full article: x - ray absorption variability is a common feature in active galactic nuclei ( agn ) .
an analysis of a sample of nearby x - ray obscured agn with multiple x - ray observations , performed a few years ago ( risaliti et al .
2002 ) revealed that column density ( n@xmath0 ) variations are almost ubiquitous in local seyfert galaxies ..
Please generate the next two sentences of the article
|
more recent observations performed with _ xmm - newton _ , _ chandra _ and _ suzaku _ further confirmed this finding .
the physical implications of these measurements are that the circumnuclear x - ray absorber ( or , at least , one component of it ) must be clumpy , and located at sub - parsec distances from the central source .
|
10,720 |
Suppose that you have an abstract for a scientific paper: a new class of lrs bianchi type @xmath0 cosmological models with free gravitational fields and a variable cosmological term is investigated in presence of perfect fluid as well as bulk viscous fluid . to get the deterministic solution we have imposed the two different conditions over the free gravitational fields . in first case we consider the free gravitational field as magnetic type whereas in second case ` gravitational wrench ' of unit pitch "
is supposed to be present in free gravitational field .
the viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density .
the cosmological constant @xmath1 is found to be a decreasing function of time and positive which is corroborated by results from recent supernovae ia observations .
the physical and geometric aspects of the models are discussed .
+ + + + + + + + pacs : 98.80.cq , 98.80.-k +
keywords : cosmology .
bianchi models . gravitational fields .
And you have already written the first three sentences of the full article: the problem of the cosmological constant is salient yet unsettled in cosmology .
the smallness of the effective cosmological constant recently observed @xmath2 poses the most difficult problems involving cosmology and elementary particle physics theory . to explain the striking cancellation between the `` bare '' cosmological constant and the ordinary vacuum energy contributions of the quantum fields ,
many mechanisms have been proposed @xcite ..
Please generate the next two sentences of the article
|
the `` cosmological constant problem '' can be expressed as the discrepancy between the negligible value of @xmath1 for the present universe as seen by the successes of newton s theory of gravitation @xcite whereas the values @xmath3 larger is expected by the glashow - salam - weinberg model @xcite and by grand unified theory ( gut ) it should be @xmath4 larger @xcite .
the cosmological term @xmath1 is then small at the present epoch simply because the universe is too old .
|
10,721 |
Suppose that you have an abstract for a scientific paper: the output of a photodetector consists of a current pulse whose charge has the statistical distribution of the actual photon numbers convolved with a bernoulli distribution .
photodetectors are characterized by a nonunit quantum efficiency , _
i.e. _ not all the photons lead to a charge , and by a finite resolution , _
i.e. _ a different number of detected photons leads to a discriminable values of the charge only up to a maximum value .
we present a detailed comparison , based on monte carlo simulated experiments and real data , among the performances of detectors with different upper limits of counting capability . in our scheme
the inversion of bernoulli convolution is performed by maximum - likelihood methods assisted by measurements taken at different quantum efficiencies .
we show that detectors that are only able to discriminate between zero , one and more than one detected photons are generally enough to provide a reliable reconstruction of the photon statistics for single - peaked distributions , while detectors with higher resolution limits do not lead to further improvements .
in addition , we demonstrate that , for semiclassical states , even on / off detectors are enough to provide a good reconstruction .
finally , we show that a reliable reconstruction of multi - peaked distributions requires either higher quantum efficiency or better capability in discriminating high number of detected photons . .
And you have already written the first three sentences of the full article: reconstruction of the photon statistics , @xmath0 , of optical states provides fundamental information on the nature of any optical field and finds relevant applications in foundations of quantum mechanics , quantum state engineering by postselection @xcite , quantum information @xcite , and quantum metrology .
indeed , detectors with the capability of counting photons @xcite are currently under investigation . among these ,
photomultiplier tubes ( pmt s ) @xcite and hybrid photodetectors @xcite are promising devices , though they have the drawback of a low quantum efficiency . on the other hand ,.
Please generate the next two sentences of the article
|
solid state detectors with internal gain are still under development .
highly efficient thermal detectors have also been used as photon counters , though their operating conditions are still extreme to allow common use @xcite .
|
10,722 |
Suppose that you have an abstract for a scientific paper: the tunneling conductance spectra of a normal - metal / insulator / quasi - one - dimensional superconductor is calculated by using the blonder - tinkham - klapwijk formulation .
the pairing symmetry of the superconductor is assumed to be @xmath0 , @xmath1 , and @xmath2-wave .
it is found that there is a well defined zero energy peak in electron tunneling along the direction parallel to the chains or normal to these when the transmitted quasiparticles feel different sign of the pair potential .
the actual line shape of the spectra is sensitive to the nodes of the pair potential on the fermi surface .
key words : tunneling spectra , organic superconductors , andreev reflection , zero energy peak 2 .
And you have already written the first three sentences of the full article: almost @xmath3 years after the discovery of the organic superconductors @xcite , the problem of determination of their pairing state has not yet found a definite solution .
the critical magnetic field @xmath4 exceeds the pauli paramagnetic limit and indicates that the pairing symmetry is triplet @xcite .
the knight shift does not change between the normal and superconducting states and it is a signature for triplet pairing state @xcite . however the absence of hebel - slichter peak and the power - low decay of @xmath5 below @xmath6 @xcite is an indication of the presence of nodes of the pair potential on the fermi surface ..
Please generate the next two sentences of the article
|
the scattering theory can be used to distinguish the symmetry of the pair potential @xcite . in @xmath1-wave superconductors the pair potential changes sign under a @xmath7-rotation .
so under appropriate orientation of the @xmath8-axis within the @xmath9 plane of @xmath1-wave superconductor the transmitted quasiparticles feel different sign of the pair potential .
|
10,723 |
Suppose that you have an abstract for a scientific paper: an improved numerical solver for the unified solution of compressible and incompressible fluids involving interfaces is proposed .
the present method is based on the cip - cup ( cubic interpolated propagation / combined , unified procedure ) method , which is a pressure - based semi - implicit solver for the euler equations of fluid flows . in part
i of this series of articles [ m. ida , comput .
phys .
commun .
132 ( 2000 ) 44 ] , we proposed an improved scheme for the convection terms in the equations , which allowed us discontinuous descriptions of the density interface by replacing the cubic interpolation function used in the cip scheme with a quadratic extrapolation function only around the interface . in this paper , as part ii of this series , the multi - time - step integration technique is adapted to the cip - cup integration . because the cip - cup treats different - nature components in the fluid equations separately ,
the adaptation of the technique is straightforward .
this modification allows us flexible determinations of the time interval , which results in an efficient and accurate integration .
furthermore , some additional discussion on our methods is presented .
finally , the application results to composite flow problems such as compressible and incompressible kelvin - helmholtz instabilities and the dynamics of two acoustically coupled deformable bubbles in a viscous liquid are provided .
unified solution , cip , compressible fluid , incompressible fluid , multi - time - step integration , extrapolation , free - surface flow , bubble dynamics 02.70.bf , 47.11.+j , 47.20.ma , 43.25.yw .
And you have already written the first three sentences of the full article: this series of articles presents an improved solver for a challenging problem , the unified solution of compressible and incompressible fluids .
after harlow and amsden proposed the ice algorithm as a fully implicit solver for fluid equations in a conservative form @xcite , some approaches for this purpose have been investigated , such as the pressure - based semi - implicit algorithms @xcite , approaches based on the asymptotic expansion with respect to the local mach number @xcite , and the boundary condition capturing method that treats compressible and incompressible materials separately @xcite .
( see also recent reviews @xcite for more details . ) among them , the cip - cup method , a pressure - based semi - implicit algorithm proposed by yabe and wang @xcite , has already been applied to many practical multi - material problems such as the laser machining of a metal plate @xcite , comet shoemaker - levy 9 s collision with the planet jupiter @xcite , the interaction of a shock wave and a liquid drop @xcite , and the milk - crown formation on a liquid surface @xcite , and has been proven to be an efficient and robust solver for the unified solution @xcite . in this method ,.
Please generate the next two sentences of the article
|
the euler ( or the navier - stokes ) equations for fluid flows in a non - conservative form are selected as the governing equations , and the convection terms in the equations are solved explicitly by the cip method @xcite , while the acoustic terms are solved implicitly by the cup method @xcite . in part
i of this series @xcite , an improved solver for the convection terms was constructed using both an interpolation and an extrapolation function to describe the spatial profile of the density of materials . in the improved method ,
|
10,724 |
Suppose that you have an abstract for a scientific paper: systems of three interacting particles are notorious for their complex physical behavior .
a landmark theoretical result in few - body quantum physics is efimov s prediction@xcite of a universal set of bound trimer states appearing for three identical bosons with a resonant two - body interaction .
counterintuitively , these states even exist in the absence of a corresponding two - body bound state .
since the formulation of efimov s problem in the context of nuclear physics 35 years ago , it has attracted great interest in many areas of physics@xcite .
however , the observation of efimov quantum states has remained an elusive goal@xcite . here
we report the observation of an efimov resonance in an ultracold gas of cesium atoms .
the resonance occurs in the range of large negative two - body scattering lengths , arising from the coupling of three free atoms to an efimov trimer .
experimentally , we observe its signature as a giant three - body recombination loss@xcite when the strength of the two - body interaction is varied .
we also detect a minimum@xcite in the recombination loss for positive scattering lengths , indicating destructive interference of decay pathways .
our results confirm central theoretical predictions of efimov physics and represent a starting point with which to explore the universal properties of resonantly interacting few - body systems@xcite .
while feshbach resonances@xcite have provided the key to control quantum - mechanical interactions on the two - body level , efimov resonances connect ultracold matter@xcite to the world of few - body quantum phenomena .
institut fr experimentalphysik , universitt innsbruck , technikerstrae 25 , a6020 innsbruck , austria james franck institute , physics department of the university of chicago , 5640 s. ellis ave .
chicago , illinois 60637 , usa institut fr quantenoptik und quanteninformation der sterreichischen akademie der wissenschaften , otto - hittmair - platz 1 , a6020 innsbruck , austria efimov s....
And you have already written the first three sentences of the full article: 12 brhl , r. , kalinin , a. , kornilov , o. , toennies , j. p. , hegerfeldt , g. c. , & stoll , m. matter wave diffraction from an inclined transmission grating : searching for the elusive @xmath90he trimer efimov state .
lett . _ * 95 * , 063002 ( 2005 ) .
we thank e. braaten , c. greene , b. esry , h. hammer , and t. khler for many stimulating and fruitful discussions and e. kneringer for support regarding the data analysis . we acknowledge support by the austrian science fund ( fwf ) within spezialforschungsbereich 15 and within the lise meitner program , and by the european union in the frame of the tmr networks `` cold molecules '' and `` fastnet '' ..
Please generate the next two sentences of the article
|
is supported within the doktorandenprogramm of the austrian academy of sciences . .
the shaded region indicates the scattering continuum for three atoms ( @xmath67 ) and for an atom and a dimer ( @xmath10 ) .
|
10,725 |
Suppose that you have an abstract for a scientific paper: we investigate quantum phase transitions in which a change in the type of entanglement from bound entanglement to either free entanglement or separability may occur .
in particular , we present a theoretical method to construct a class of quantum spin - chain hamiltonians that exhibit this type of quantum criticality . given parameter - dependent two - site reduced density matrices ( with prescribed entanglement properties )
, we lay out a reverse construction for a compatible pure state for the whole system , as well as a class of hamiltonians for which this pure state is a ground state .
this construction is illustrated through several examples . .
And you have already written the first three sentences of the full article: entanglement , a key concept in quantum - information science @xcite , has also been playing a pivotal role in the study of quantum ( or , generally , nonclassical ) correlations and related consequences in many - body systems @xcite , especially quantum phase transitions ( qpts ) induced by varying parameters of system hamiltonian at zero temperature @xcite ( see also refs . @xcite for geometric approaches to qpts . ) . accordingly
, many efforts have been made to find the possible relation between qpt in a system and nonanalyticities of , e.g. , pairwise entanglement of its ground state ( gs ) @xcite .
for example , under some fairly general conditions , a classification of qpts in terms of pairwise entanglement has been provided in ref ..
Please generate the next two sentences of the article
|
besides , through density functional theoretical arguments , it has been shown that by an appropriate choice of entanglement measure ( either bi- or multipartite ) , one can study physical properties of a system near its critical points @xcite .
it is thus evident that having a sufficiently strong entanglement measure which is able to detect entanglement regions of the gs ( in terms of the hamiltonian parameters ) in a more subtle way is of paramount importance .
|
10,726 |
Suppose that you have an abstract for a scientific paper: we derive the co - to - h@xmath0 conversion factor , @xmath1 = @xmath2(h@xmath0)/@xmath3 , across the perseus molecular cloud on sub - parsec scales by combining the dust - based @xmath2(h@xmath0 ) data with the @xmath3 data from the complete survey .
we estimate an average @xmath1 @xmath4 3 @xmath5 10@xmath6 @xmath7 k@xmath8 km@xmath8 s and find a factor of @xmath43 variations in @xmath1 between the five sub - regions in perseus . within the individual regions ,
@xmath1 varies by a factor of @xmath4100 , suggesting that @xmath1 strongly depends on local conditions in the interstellar medium .
we find that @xmath1 sharply decreases at @xmath9 @xmath10 3 mag but gradually increases at @xmath9 @xmath11 3 mag , with the transition occuring at @xmath9 where @xmath3 becomes optically thick .
we compare the @xmath2(hi ) , @xmath2(h@xmath0 ) , @xmath3 , and @xmath1 distributions with two models of the formation of molecular gas , a one - dimensional photodissociation region ( pdr ) model and a three - dimensional magnetohydrodynamic ( mhd ) model tracking both the dynamical and chemical evolution of gas .
the pdr model based on the steady state and equilibrium chemistry reproduces our data very well but requires a diffuse halo to match the observed @xmath2(hi ) and @xmath3 distributions .
the mhd model matches our data reasonably well , suggesting that time - dependent effects on h@xmath0 and co formation are insignificant for an evolved molecular cloud like perseus .
however , we find interesting discrepancies , including a broader range of @xmath2(hi ) , likely underestimated @xmath3 , and a large scatter of @xmath3 at small @xmath9 .
these discrepancies most likely result from strong compressions / rarefactions and density fluctuations in the mhd model . .
And you have already written the first three sentences of the full article: stars form exclusively in molecular clouds , although the question whether molecular gas is a prerequisite or a byproduct of star formation is currently under debate ( e.g. , glover & clark 2012 ; kennicutt & evans 2012 ; krumholz 2012 ) . in either case ,
accurate measuruments of the physical properties of molecular clouds are critical to constrain the initial conditions for star and molecular gas formation . however , obtaining such measurements is hampered by the fact that molecular hydrogen ( h@xmath0 ) , the most abundant molecular species in the interstellar medium ( ism ) , is not directly observed under the typical conditions in molecular clouds . as a homonuclear diatomic molecule , h@xmath0 does not have a permanent electric dipole moment and its ro - vibrational states change only via weak quadrupole transitions . therefore ,
alternative tracers have been employed to infer the abundance and distribution of h@xmath0 ..
Please generate the next two sentences of the article
|
carbon monoxide ( co ) is one of the most commonly used tracers of h@xmath0 due to its large abundance and low rotational transitions that are readily excited in molecular clouds through collisions with h@xmath0 . in particular , the @xmath12co(@xmath13 ) integrated intensity , @xmath3 , is often used to estimate the h@xmath0 column density , @xmath2(h@xmath0 ) , via the so - called `` @xmath14-factor '' , which is defined by @xmath15 accurate knowledge of @xmath1 is crucial to address some of the fundamental questions in astrophysics .
for example , one of the most intriguing properties of galaxies is a strong power - law relation between the surface density of star formation rate , @xmath16 , and the surface density of h@xmath0 , @xmath17 , generally known as the `` kennicutt - schmidt relation '' ( e.g. , schmidt 1959 ; kennicutt 1989 ; bigiel et al .
|
10,727 |
Suppose that you have an abstract for a scientific paper: the non - gaussian contribution to the intrinsic halo spin alignments is analytically modeled and numerically detected . assuming that the growth of non - gaussianity in the density fluctuations caused the tidal field to have nonlinear - order effect on the orientations of the halo angular momentum , we model the intrinsic halo spin alignments as a linear scaling of the density correlations on large scales , which is different from the previous quadratic - scaling model based on the linear tidal torque theory .
then , we analyze the halo catalogs from the recent high - resolution millennium run simulation at four different redshifts ( @xmath0 and @xmath1 ) and measure quantitatively the degree of the nonlinear effect on the halo spin alignments and its changes with redshifts .
a clear signal of spin correlations is found on scales as large as @xmath2mpc at @xmath3 , which marks a detection of the nonlinear tidal effect on the intrinsic halo alignments .
we also investigate how the nonlinear effect depends on the intrinsic properties of the halos .
it is found that the degree of the nonlinear tidal effect increases as the halo mass scale decreases , the halo specific angular momentum increases , and the halo peculiar velocity decreases .
we discuss implication of our result on the weak gravitational lensing . .
And you have already written the first three sentences of the full article: the intrinsic galaxy alignment refers to a cosmic phenomenon that the orientations of the galaxy spin axes ( or galaxy ellipticities ) are not random but locally aligned between neighbors due to the spatial correlations of the initial tidal field .
the topic of the intrinsic galaxy alignments has recently drawn considerable attention in the field of the large - scale structure for three reasons .
firstly , since it is believed to be induced by the spatial correlations of the initial tidal field , it will be possible in principle by measuring the galaxy intrinsic alignments to reconstruct the initial density field on galactic scales @xcite . secondly , the initial tidal correlations are also responsible for the web - like distribution of the large scale structures @xcite ..
Please generate the next two sentences of the article
|
thus , the galaxy intrinsic alignments will be useful to characterize and quantify the influence of the large - scale structures on the orientations of the galaxies distributed in a cosmic web @xcite .
thirdly and most importantly , the galaxy intrinsic alignments could cause non - negligible contamination on weak lensing signals .
|
10,728 |
Suppose that you have an abstract for a scientific paper: we challenge the hypothesis that the ground states of a physical system whose degeneracy depends on topology must necessarily realize topological quantum order and display non - local entanglement . to this end
, we introduce and study a classical rendition of the toric code model embedded on riemann surfaces of different genus numbers .
we find that the minimal ground state degeneracy ( and those of all levels ) depends on the topology of the embedding surface alone . as the ground states of this classical system
may be distinguished by local measurements , a characteristic of landau orders , this example illustrates that topological degeneracy is not a sufficient condition for topological quantum order .
this conclusion is generic and , as shown , it applies to many other models .
we also demonstrate that certain lattice realizations of these models , and other theories , display a ground state entropy ( and those of all levels ) that is holographic " , i.e. , extensive in the system boundary .
we find that clock and @xmath0 gauge theories display topological ( in addition to gauge ) degeneracies . .
And you have already written the first three sentences of the full article: the primary purpose of the current paper is to show that , as a matter of principle , contrary to discerning lore that is realized in many fascinating systems , e.g. , @xcite , the appearance of a _ topological _ ground state degeneracy _ does not _ imply that these degenerate states are `` topologically ordered '' , in the sense that local perturbations can be detected without destroying the encoded quantum information @xcite . towards this end ,
we introduce various models , including a classical version of kitaev s toric code @xcite , that exhibit robust genus dependent degeneracies but are nonetheless landau ordered .
those models do not harbor long - range entangled ground states that can not be told apart from one another by local measurements ..
Please generate the next two sentences of the article
|
rather , they ( as well as all other eigenstates ) are trivial classical states . along the way we will discover that these two - dimensional classical models ( including rather mundane clock and @xmath0 gauge like theories with four spin interactions ( specifically , toric clock and @xmath0 theories that we will define ) may not only have genus dependent symmetries and degeneracies but
, for various lattice types , may also exhibit _ holographic _ degeneracies that scale exponentially in the system perimeter .
|
10,729 |
Suppose that you have an abstract for a scientific paper: we investigate the behavior of the @xmath0 casson invariant for 3-manifolds obtained by dehn surgery along two - bridge knots . using the results of hatcher and thurston , and also results of ohtsuki
, we outline how to compute the culler
shalen seminorms , and we illustrate this approach by providing explicit computations for double twist knots .
we then apply the surgery formula to deduce the @xmath0 casson invariant for the 3-manifolds obtained by @xmath1dehn surgery on such knots .
these results are applied to prove nontriviality of the @xmath0 casson invariant for nearly all 3-manifolds obtained by nontrivial dehn surgery on a hyperbolic two - bridge knot .
we relate the formulas derived to degrees of @xmath2-polynomials and use this information to identify factors of higher multiplicity in the @xmath3-polynomial , which is the @xmath2-polynomial with multiplicities as defined by boyer - zhang .
[ multiblock footnote omitted ] .
And you have already written the first three sentences of the full article: the goal of this paper is to provide computations of the @xmath0 casson invariant for 3-manifolds obtained by dehn surgery on a two - bridge knot .
our approach is to apply the dehn surgery formula of @xcite and @xcite , and this involves computing the culler shalen seminorms . in general
, the surgery formula applies to dehn surgeries on small knots @xmath4 in homology spheres @xmath5 , and a well - known result of hatcher and thurston @xcite shows that all two - bridge knots are small . the culler .
Please generate the next two sentences of the article
|
shalen seminorm plays a key role in the surgery formula , and we use the results of ohtsuki @xcite to provide the required computations . as an application , using the classification of exceptional dehn surgeries on two - bridge knots from @xcite ,
we prove that nearly all 3-manifolds given by a nontrivial @xmath1dehn surgery on a hyperbolic two - bridge knot @xmath4 have nontrivial @xmath0 casson invariant . in our previous work ( * ? ? ?
|
10,730 |
Suppose that you have an abstract for a scientific paper: chiral discrimination with high harmonic generation ( chhg method ) has been introduced in the recent work by r. cireasa et al ( _ nat
. phys . _ * 11 * , 654 - 658 , 2015 ) . in its original implementation
, the chhg method works by detecting high harmonic emission from randomly oriented ensemble of chiral molecules driven by elliptically polarized field , as a function of ellipticity .
here we discuss future perspectives in the development of this novel method , the ways of increasing chiral dichroism using tailored laser pulses , new detection schemes involving high harmonic phase measurements , and concentration - independent approaches . using the example of the epoxypropane molecule c@xmath0h@xmath1o (
also known as 1,2-propylene oxide ) , we show theoretically that application of two - color counter - rotating elliptically polarized laser fields yields an order of magnitude enhancement of chiral dichroism compared to single color elliptical fields .
we also describe how one can introduce a new functionality to chhg : concentration - independent measurement of the enatiomeric excess in a mixture of randomly oriented left - handed and right - handed molecules .
finally , for arbitrary configurations of laser fields , we connect the observables of the chhg method to the amplitude and phase of chiral response , providing a basis for reconstructing wide range of chiral dynamics from chhg measurements , with femtosecond to sub - femtosecond temporal resolution . .
And you have already written the first three sentences of the full article: ever since their discovery , chiral molecular systems puzzled and inspired researches .
the mirror symmetry , characterizing two molecular enatiomers , is possibly the simplest broken symmetry to think of .
the complexity and variety of interactions and occurrences in nature of different enatiomers , flowing from such a small difference in their structure , is amazing ..
Please generate the next two sentences of the article
|
chiral nature of living matter poses both fundamental and practical questions , from the origins of homochirality in biomolecules @xcite to detection and manipulation @xcite of chiral properties .
the oldest method used to detect chirality in such media is optical rotation : the polarization plane of a linearly polarized light propagating through left and right chiral media rotates in opposite directions ( see e.g. optical rotation measurement in epoxypropane molecule ; we shall use this molecule to illustrate our concepts here @xcite ) , microscopically , optical rotation is governed by the interplay of dipole transitions in a chiral medium caused by electric and magnetic fields of a light wave .
|
10,731 |
Suppose that you have an abstract for a scientific paper: in this paper we will extend the product of spectral triples to a product of semifinite spectral triples .
we will prove that finite summability and regularity are preserved under taking products .
connes and marcolli constructed for each @xmath0 a type @xmath1-semifinite spectral triple which can be considered as a geometric space of dimension @xmath2 . a small adaption of their construction yields a type @xmath3-semifinite spectral triple .
we will investigate the properties of these semifinite spectral triples . at the same time
we will also avoid the need for an infra - red cutoff to compute the dimension spectrum .
using this collection of semifinite spectral triples and the product of semifinite spectral triples one can construct a mathematical tool for dimensional and zeta - function regularisation in quantum field theory .
real dimensional spaces in noncommutative geometry .
And you have already written the first three sentences of the full article: in cite @xcite hooft and veltman developed the method of dimensional regularisation to deal with divergent integrals in quantum field theory .
the idea they had was to evaluated the corresponding integrals in @xmath4 dimensions for @xmath5 instead of the original @xmath6 dimensions .
this approach plays a key role in modern quantum field theory computations ..
Please generate the next two sentences of the article
|
it is therefore a natural question whether it is possible to mathematically construct geometric spaces which have dimension @xmath7 .
as described by connes and marcolli in @xcite this is indeed possible in the framework of noncommutative geometry .
|
10,732 |
Suppose that you have an abstract for a scientific paper: we describe a variety of methods to compute the functions @xmath0 , @xmath1 and their derivatives for real @xmath2 and positive @xmath3 .
these functions are numerically satisfactory independent solutions of the differential equation @xmath4 . in the accompanying paper @xcite
, we describe the implementation of these methods in fortran 77 codes . .
And you have already written the first three sentences of the full article: in previous publications @xcite , methods to compute the modified bessel function @xmath0 for positive @xmath3 were described .
we complete here this analysis by describing analogous methods for the computation of the function @xmath1 . with this
, methods for the reliable computation of a pair of linearly independent numerically satisfactory solutions become available which find their implementation in the accompanying paper @xcite . methods to compute their derivatives are also provided ..
Please generate the next two sentences of the article
|
the functions @xmath0 and @xmath1 are solutions of the modified bessel equation for imaginary orders @xmath5 the function @xmath0 finds application in a number of problems of physics and applied mathematics @xcite .
the function @xmath1 is a real valued numerically satisfactory companion to @xmath0 in the sense described in @xcite , pp .
|
10,733 |
Suppose that you have an abstract for a scientific paper: inelastic scattering of electrons incident on a solid surface is determined by the two properties : ( i ) electronic response of the target system and ( ii ) the detailed quantum - mechanical motion of the projectile electron inside and in the vicinity of the target .
we emphasize the equal importance of the second ingredient , pointing out the fundamental limitations of the conventionally used theoretical description of the electron energy - loss spectroscopy ( eels ) in terms of the `` energy - loss functions '' .
our approach encompasses the dipole and impact scattering as specific cases , with the emphasis on the quantum - mechanical treatment of the probe electron .
applied to the high - resolution eels of ag surface , our theory largely agrees with recent experiments , while some instructive exceptions are rationalized . .
And you have already written the first three sentences of the full article: electron energy - loss spectroscopy ( eels ) is an efficient and widely used experimental method to study excitation processes on clean and adsorbates - covered surfaces of solids , and in thin ( including atomically thin ) films @xcite .
this method utilizes the inelastic scattering of electrons , resulting in both the energy and momentum transfer from the projectiles to diverse kinds of excitations in the samples . reflected or transmitted electrons
are analyzed with respect to the energy and momentum loss they have experienced in the interaction with a target , revealing a wealth of information about the properties of the latter ..
Please generate the next two sentences of the article
|
much efforts have been exerted over years to complement eels experimental techniques with comprehensive theoretical pictures @xcite . in this way , a clear understanding of elementary excitations ( such as electron - hole pairs generation , collective electronic excitations
plasmons , atomic vibrational modes , _ etc . _ ) , including their momentum dispersion , for solid surfaces , interfaces , and in thin films have been achieved .
|
10,734 |
Suppose that you have an abstract for a scientific paper: we introduce the characteristic operator as the generalization of the usual concept of a transfer function of linear input - plant - output systems to arbitrary quantum nonlinear markovian input - output models .
this is intended as a tool in the characterization of quantum feedback control systems that fits in with the general theory of networks .
the definition exploits the linearity of noise differentials in both the plant heisenberg equations of motion and the differential form of the input - output relations .
mathematically , the characteristic operator is a matrix of dimension equal to the number of outputs times the number of inputs ( which must coincide ) , but with entries that are operators of the plant system . in this sense
the characteristic operator retains details of the effective plant dynamical structure and is an essentially quantum object .
we illustrate the relevance to model reduction and simplification definition by showing that the convergence of the characteristic operator in adiabatic elimination limit models requires the same conditions and assumptions appearing in the work on limit quantum stochastic differential theorems of bouten and silberfarb @xcite .
this approach also shows in a natural way that the limit coefficients of the quantum stochastic differential equations in adiabatic elimination problems arise algebraically as schur complements , and amounts to a model reduction where the fast degrees of freedom are decoupled from the slow ones , and eliminated . .
And you have already written the first three sentences of the full article: there has been much interest lately in the behavior and control of quantum linear systems , particularly as these are amenable to transfer matrix function techniques . in this note
, we wish to exploit the structural features of quantum markovian models to construct an analogue of the transfer matrix function for non - linear systems .
coming from the classical direction there has been fruitful application of operator techniques to control systems in recent years @xcite employing for instance characteristic functions techniques , multi - analytic operators and commutant lifting methods ..
Please generate the next two sentences of the article
|
here we introduce a natural characteristic operator function associated with a quantum markov ( or slh ) model . as in standard quantum mechanics ,
the model is formulated by representing physical quantities ( observables ) as self - adjoint operators on a hilbert space . the quantum mechanical system ( plant )
|
10,735 |
Suppose that you have an abstract for a scientific paper: we discuss the impact of recent developments in the theory of chaotic dynamical systems , particularly the results of sinai and ruelle , on microwave experiments designed to study quantum chaos .
the properties of closed sinai billiard microwave cavities are discussed in terms of universal predictions from random matrix theory , as well as periodic orbit contributions which manifest as ` scars ' in eigenfunctions .
the semiclassical and classical ruelle zeta - functions lead to quantum and classical resonances , both of which are observed in microwave experiments on @xmath0-disk hyperbolic billiards .
* key words * : microwave , hyperbolic , sinai billiard , correlation , ruelle zeta - function , resonances .
And you have already written the first three sentences of the full article: it may come as a pleasant surprise to the dynamical systems community , to learn that the work of yasha sinai and david ruelle has had a major impact in experiments on microwave geometries .
the connections arise from recent developments which demonstrate that wave mechanics experiments using microwaves are an ideal laboratory for studying the so - called quantum - classical correspondence , a central issue in quantum chaos .
these microwave experiments have shown that several theoretical results on the mathematics of chaotic dynamical systems have manifestations in their corresponding quantum or wave mechanics ..
Please generate the next two sentences of the article
|
the term chaos often means hyperbolicity which guarantees the decomposition of the tangent space at each phase space point into expansion and contraction subspaces .
a systematic study of hyperbolic systems from the geometric theory perspective was initiated by smale @xcite .
|
10,736 |
Suppose that you have an abstract for a scientific paper: as part of our multiwavelength campaign of observations of gx 3394 in 1996 we present our keck spectroscopy performed on may 12 ut . at this time , neither the asm on the _ rossi x - ray timing explorer _ nor batse on the _ compton gamma - ray observatory _ detected the source .
the optical emission was still dominated by the accretion disk with @xmath0 mag .
the dominant emission line is , and for the first time we are able to resolve a double peaked profile . the peak separation @xmath1 .
double peaked emission lines have been seen in the quiescent optical counterparts of many black hole x - ray novae .
however , we find that the peak separation is significantly smaller in gx 3394 , implying that the optical emission comes from a larger radius than in the novae
. the emission line may be more akin to the one in cygnus x-1 , where it is very difficult to determine if the line is intrinsically double peaked because absorption and emission lines from the companion star dominate . .
And you have already written the first three sentences of the full article: most galactic black hole candidates exhibit at least two distinct spectral states ( see liang & narayan 1997 , liang 1998 , poutanen 1998 for reviews ) . in the hard state
(= soft x - ray low state ) the spectrum from @xmath2 kev to a few hundred kev is a hard power law ( photon index @xmath3 ) with an exponential cutoff .
this can be interpreted as inverse comptonization of soft photons . in the soft state.
Please generate the next two sentences of the article
|
( often , but not always , accompanied by the soft x - ray high state ) , the spectrum above @xmath4 kev is a steep power law ( photon index @xmath5 ) with no detectable cutoff out to @xmath2 mev .
this multi - state behavior is seen in both persistent sources ( e.g. cygnus x-1 ) and transient black hole x - ray novae ( bhxrn , e.g. grs 100945 ) .
|
10,737 |
Suppose that you have an abstract for a scientific paper: in this paper we present the results of observations of seventeen hii regions in thirteen galaxies from the sigrid sample of isolated gas rich irregular dwarf galaxies .
the spectra of all but one of the galaxies exhibit the auroral [ o iii ] 4363 line , from which we calculate the electron temperature , t@xmath0 , and gas - phase oxygen abundance .
five of the objects are blue compact dwarf ( bcd ) galaxies , of which four have not previously been analysed spectroscopically .
we include one unusual galaxy which exhibits no evidence of the [ n ii ] @xmath1 6548,6584 lines , suggesting a particularly low metallicity ( @xmath2 z@xmath3/30 ) .
we compare the electron temperature based abundances with those derived using eight of the new strong line diagnostics presented by @xcite . using a method derived from first principles for calculating total oxygen abundance ,
we show that the discrepancy between the t@xmath0-based and strong line gas - phase abundances have now been reduced to within @xmath40.07 dex .
the chemical abundances are consistent with what is expected from the luminosity metallicity relation .
we derive estimates of the electron densities and find them to be between @xmath45 and @xmath4100 @xmath5 .
we find no evidence for a nitrogen plateau for objects in this sample with metallicities 0.5 @xmath6 z@xmath3 @xmath6 0.15 . .
And you have already written the first three sentences of the full article: the metallicity of hii regions in small isolated dwarf galaxies is key to investigating the physical processes that govern star formation in undisturbed stellar systems .
the small isolated gas rich irregular dwarf galaxy ( sigrid ) sample of small isolated gas rich irregular dwarf galaxies @xcite was selected with the aim of exploring the behavior of the mass or luminosity metallicity relation at the low end of the mass scale .
this is based on the observation that nebular metallicity decreases with galaxy stellar mass / luminosity ( see , for example , * ? ? ?.
Please generate the next two sentences of the article
|
* ; * ? ? ?
however , the low end of the mass scale shows significantly more scatter in metallicity than the high end in the tremonti sdss data . by selecting isolated dwarf galaxies
|
10,738 |
Suppose that you have an abstract for a scientific paper: the 499 pixel photomultiplier cameras of the veritas gamma ray telescopes are instrumented with 500mhz sampling flash adcs .
this paper describes a preliminary investigation of the best methods by which to exploit this information so as to optimize the signal - to - noise ratio for the detection of cherenkov light pulses .
the fadcs also provide unprecedented resolution for the study of the timing characteristics of cherenkov images of cosmic - ray and gamma - ray air showers .
this capability is discussed , together with the implications for gamma - hadron separation . .
And you have already written the first three sentences of the full article: imaging atmospheric cherenkov telescopes use large mirror areas to reflect the cherenkov photons from cosmic - ray and gamma - ray air showers onto a photo - detector camera , usually comprised of photo - multiplier tubes ( pmts ) .
the number of photoelectrons generated at each pmt is directly proportional to the charge under the pmt output pulse , and this is easily measured using adcs with fixed - length integration gates .
an alternative method is to use `` flash '' adcs to rapidly sample the output pulse and record the complete pulse shape ..
Please generate the next two sentences of the article
|
this allows to maximize the signal - to - noise ratio for individual pulses at the analysis stage , lowering the effective energy threshold of the telescope @xcite .
a number of authors have suggested that the timing and pulse shape information could also be used to improve sensitivity through improved gamma - hadron separation or better reconstruction of shower parameters ( core location , primary energy , etc . )
|
10,739 |
Suppose that you have an abstract for a scientific paper: we present a new derivation of the cosmic microwave background anisotropy spectrum from the ostriker - vishniac effect for an open , flat , or closed universe , and calculate the anisotropy expected in cold dark - matter ( cdm ) models .
we provide simple semi - analytic fitting formulas for the vishniac power spectrum that can be used to evaluate the expected anisotropy in cdm models for any arbitrary ionization history . in a flat universe ,
cdm models normalized to cluster abundances produce rms temperature anisotropies of 0.82.4 @xmath0k on arcminute angular scales for a constant ionization fraction of unity , whereas an ionization fraction of 0.2 yields rms anisotropies of 0.30.8 @xmath0k . in an open and/or high - baryon - density universe ,
the level of anisotropy is somewhat higher .
the signal in some of these models may be detectable with planned interferometry experiments .
the damping of the acoustic peaks in the primary - anisotropy spectrum at degree angular scales depends primarily on the optical depth and only secondarily on the epoch of reionization . on the other hand ,
the amplitude of ostriker - vishniac anisotropies depends sensitively on the epoch of reionization .
therefore , when combined with the estimate of the reionization optical depth provided by maps of degree - scale anisotropies , the ostriker - vishniac effect can provide a unique probe of the epoch of reionization .
# 1#1 # 1 .
And you have already written the first three sentences of the full article: standard cold dark matter ( cdm ) and its variants are the current leading models for the origin of large - scale structure . the canonical cdm model hypothesizes a primordial scale - free spectrum of primordial adiabatic perturbations and a critical density of cold dark matter .
its variants include low - density ( e.g. , @xmath1 ) models , either in an open universe or in a flat universe with a cosmological constant , tilted models in which the power - law index @xmath2 of the primordial power spectrum differs slightly from scale - free ( @xmath3 ) , low
hubble - constant models , or mixed - dark - matter models in which the universe has a critical density but roughly 30% is in the form of hot dark matter ..
Please generate the next two sentences of the article
|
although most of the matter in these models does not undergo gravitational collapse until relatively late in the history of the universe , some small fraction of the mass is expected to collapse at early times .
ultraviolet photons released by this early generation of star and/or galaxy formation will partially reionize the universe , and these ionized electrons will re - scatter at least some cosmic microwave background ( cmb ) photons after recombination at a redshift of @xmath4 .
|
10,740 |
Suppose that you have an abstract for a scientific paper: one of the most fundamental problems in the study of kuiper belt objects ( kbos ) is to know their true physical size . without knowledge of their albedos
we are not able to distinguish large and dark from small and bright kbos . _
spitzer _ produced rough estimates of the sizes and albedos of about 20 kbos , and the _ herschel _ space telescope will improve on those initial measurements by extending the sample to the @xmath0150 brightest kbos .
_ spica _ s higher sensitivity instruments should allow us not only to broaden the sample to smaller kbos but also to achieve a statistically significant sample of kbo thermal light curves ( _ herschel _ will measure only six objects ) .
a large sample covering a broad range of sizes will be key to identify meaningful correlations between size and other physical and surface properties that constrain the processes of formation and evolution of the solar system . .
And you have already written the first three sentences of the full article: in this paper i discuss the importance of the upcoming _ ` space infrared telescope for cosmology & astrophysics ' _ ( hereafter , _ spica _ ) for the study of the icy small bodies of the outer solar system . here , i focus on the study of kuiper belt objects ( kbos ) but the same ideas can be applied to any atmosphereless bodies .
i will mainly discuss how _ spica _ can help us to measure the sizes of kbos , and how that leads to more accurate estimates of the size distribution and total mass of kbos .
i will also mention how this new infrared space telescope might probe the rotational properties , chemical composition and thermophysical parameters of those icy bodies ..
Please generate the next two sentences of the article
|
other uses of a space - based infrared telescope for solar system studies are detailed elsewhere , in the context of _ spica _
s precursor observatory , _ herschel _ @xcite . in 2 to 4
|
10,741 |
Suppose that you have an abstract for a scientific paper: quantum computation strongly relies on the realisation , manipulation and control of qubits . a central method for realizing qubits is by creating a double - well potential system with a significant gap between the first two eigenvalues and the rest . in this work
we first revisit the theoretical grounds underlying the double - well qubit dynamics , then proceed to suggest novel extensions of these principles to a triple - well qutrit with periodic boundary conditions , followed by a general @xmath0-well analysis of qudits .
these analyses are based on representations of the special unitary groups @xmath1 which expose the systems symmetry and employ them for performing computations .
we conclude with a few notes on coherence and scalability of @xmath0-well systems . .
And you have already written the first three sentences of the full article: the use of quantum mechanical systems for information processing and computation has been studied extensively over the last decades .
models have been well established for using the principles of quantum mechanics to achieve computational advantages in the form of a speedup over classical methods , and to allow efficient simulation of physical systems . however , a central challenge on the way to fulfilling these goals continues to lie in the realisation of such systems - how to construct a large - scale system , which entails the required quantum properties and at the same time allows efficient manipulations necessary for performing these tasks .
some of the main techniques for the realisation problem feature the use of a _ double - well potential _ system to store and manipulate the qubit ..
Please generate the next two sentences of the article
|
realisations of a double - well - based qubit have been demonstrated using superconducting circuits ( _ squid _ ) , which provide efficient control over the qubit transformations and feasible integration with electronic circuitry @xcite . as an alternative to the qubit
, work has been done to study the analogue 3-state register , the _ qutrit _ , and more generally the @xmath0-state _ qudit_. several advantages of using qutrits and qudits rather than qubits have been discussed , e.g. in the context of improved fault - tolerance @xcite and advantages in cryptography @xcite . motivated by these results we suggest a novel _ periodic triple - well qutrit _ system . on the one hand
|
10,742 |
Suppose that you have an abstract for a scientific paper: we study gravity mediated supersymmetry breaking in @xmath0-@xmath1 and its low - energy supersymmetric phenomenology .
the gaugino masses are not unified at the traditional grand unification scale , but we nonetheless have the same one - loop gaugino mass relation at the electroweak scale as minimal supergravity ( msugra ) .
we introduce parameters testable at the colliders to measure the small second loop deviation from the msugra gaugino mass relation at the electroweak scale . in the minimal @xmath1 model with gravity mediated supersymmetry breaking , we show that the deviations from the msugra gaugino mass relations are within 5% .
however , in @xmath0-@xmath1 , we predict the deviations from the msugra gaugino mass relations to be larger due to the presence of vector - like particles , which can be tested at the colliders .
we determine the viable parameter space that satisfies all the latest experimental constraints and find it is consistent with the cdms ii experiment .
further , we compute the cross - sections of neutralino annihilations into gamma - rays and compare to the first published fermi - lat measurement . finally , the corresponding range of proton lifetime predictions is calculated and found to be within reach of the future hyper - kamiokande and dusel experiments . .
And you have already written the first three sentences of the full article: as we initiate the era of the large hadron collider ( lhc ) , we await with anticipation the expected discovery of supersymmetry and the higgs states required to break electroweak symmetry and stabilize the electroweak scale . on the other hand
, there is thus far no concrete model that can explain all observed physics in a comprehensive mathematical framework .
unique predictions that can be tested at the lhc , future international linear collider ( ilc ) , and other forthcoming experiments are necessary if string theory is to be substantiated as the correct fundamental description of nature . following a top - down approach , it may be feasible to derive all known observable physics from a fundamental theory such as string theory ..
Please generate the next two sentences of the article
|
in contrast , the bottom - up approach offers the possibility to infer the framework of the fundamental theory at high - energy from a low - energy signal at the experiments . in the spirit of this bottom - up approach ,
our goal here is to study grand unified theories ( guts ) from f - theory , which have seen exciting progress the past two years , and present f - theory gut low - energy physics observable at current and future experiments .
|
10,743 |
Suppose that you have an abstract for a scientific paper: in this contribution , a review of some of the most important qcd jet preliminary results from both cdf and d0 experiments in run ii is presented , together with future prospects as the integrated luminosity increases .
= 14.5pt .
And you have already written the first three sentences of the full article: the run ii at tevatron will define a new level of precision for qcd studies in hadron collisions .
both collider experiments , cdf and d0 , expect to collect up to @xmath0 of data in this new run period .
the increase in instantaneous luminosity , center - of - mass energy ( from 1.8 tev to 1.96 tev ) and the improved acceptance of the detectors will allow stringent tests of the standard model ( sm ) predictions in extended regions of jet transverse momentum , @xmath1 , and jet rapidity , @xmath2 . in this contribution , a review of some of the most important qcd results from run ii is presented , together with future prospects as the integrated luminosity increases ..
Please generate the next two sentences of the article
|
the measurement of the inclusive jet production cross section for central jets constitutes one of the pillars of the jet physics program at the tevatron .
it provides a stringent test of perturbative qcd predictions over almost nine orders of magnitude and probes distances up to @xmath3 .
|
10,744 |
Suppose that you have an abstract for a scientific paper: we investigate the obstructed motion of tracer ( test ) particles in crowded environments by carrying simulations of two - dimensional gaussian random walk in model fibrinogen monolayers of different orientational ordering .
the fibrinogen molecules are significantly anisotropic and therefore they can form structures where orientational ordering , similar to the one observed in nematic liquid crystals , appears .
the work focuses on the dependence between level of the orientational order ( degree of environmental crowding ) of fibrinogen molecules inside a layer and non - fickian character of the diffusion process of spherical tracer particles moving within the domain .
it is shown that in general particles motion is subdiffusive and strongly anisotropic , and its characteristic features significantly change with the orientational order parameter , concentration of fibrinogens and radius of a diffusing probe . .
And you have already written the first three sentences of the full article: the obstructed transport in disordered and inhomogeneous systems may lead to anomalous diffusion .
transport of a dense fluid in a porous host structure , ballistic tracer motion in a spatially heterogeneous medium , a probe or solute diffusing through fixed scatterers within liquid crystalline phases and protein motion in cellular membranes or in cytoplasm , all exhibit characteristics typical for hindered diffusion @xcite .
models of such systems usually include variants of lorentz approach @xcite in which static scatterers are fixed in space and tracer particles are allowed to move freely through the resulting mesh ..
Please generate the next two sentences of the article
|
the obstacle density is crucial for the anisotropy of motion and excluded volume effects , since only unoccupied , void volume is accessible to the probe particle traveling in the system . in the original lorentz model proposed as a description of the electric conductivity of metals , the motion of a ballistic particle elastically scattered off
randomly distributed spherical obstacles has been analyzed .
|
10,745 |
Suppose that you have an abstract for a scientific paper: we explore the role that red giants might play in the fuelling and evolution of active galactic nuclei . due to their large radii and the low binding energy of the stellar envelope
, giants are vulnerable to envelope stripping from collisions with the accretion disk . using hydrodynamic simulations
we show that such collisions will typically deposit a substantial fraction of the envelope mass into the disk on each passage .
repeated encounters will then lead to the complete destruction of the star save for the dense core .
we estimate the rate of fuel supply by this mechanism using simple models for the agn disk and central stellar cluster .
if the central stellar density is @xmath0 , then stripping of giants could account for the activity of typical agn provided that the accretion disk extends out to @xmath1 pc . for agn with smaller disks , or clusters of lower central density , giant stripping could supply gas enriched via stellar nucleosynthesis to a disk replenished from some other source .
we find that , for typical parameters , this mechanism is able to supply important quantities of gas to the disk at lower stellar densities than previously proposed stellar fuelling models for agn . .
And you have already written the first three sentences of the full article: understanding the origin and evolution of the fuel supply that feeds quasars and other active galactic nuclei ( agn ) is a key mystery in the astrophysics of these systems . to account for luminosities as high as @xmath2 erg / s the most efficient conceivable process - accretion onto a black hole - requires a mass supply of order one solar mass per year . that matter ( which over the lifetime of the active phase may amount to @xmath3 or more )
must be transported from galactic scales down to the schwarzschild radius of the hole at just a few a.u .
evidently this transport mandates an efficient mechanism for disposing of the inflowing material s angular momentum . a partial solution to the problem is provided by invoking the presence of an accretion disk in the immediate vicinity of the hole . although the details are uncertain , viscosity in the disk transports angular momentum outward , and thereby permits mass to flow inward ..
Please generate the next two sentences of the article
|
recent observations by _ asca _ of relativistically broadened iron @xmath4 lines lend strong support to the idea of the existence of both massive black holes and disks in agn ( tanaka et al .
1995 ) . for the purpose of fuelling the hole , however , the disk is unlikely to provide more than a short term reservoir of mass , as models suggest that the disk mass is only a small fraction ( perhaps @xmath5 for a @xmath6 black hole ) of the mass of the hole ( e.g. clarke 1988 ) . even allowing for generous uncertainties in our models of accretion disks
|
10,746 |
Suppose that you have an abstract for a scientific paper: we present a systematic study of the variations of the @xmath0li nmr properties versus magnetic defect concentration @xmath1 within the spinel structure of polycrystalline powder samples ( @xmath2 , and 0.83 mol% ) and a collection of small single crystals ( @xmath3 mol% ) of liv@xmath4o@xmath5 in the temperature range from 0.5 to 4.2 k. we also report static magnetization measurements and ac magnetic susceptibility measurements at 14 mhz on the samples at low temperatures .
both the @xmath6li nmr spectrum and nuclear spin - lattice relaxation rate are inhomogeneous in the presence of the magnetic defects .
the @xmath6li nmr data for the _ powders _ are well explained by assuming that ( i ) there is a random distribution of magnetic point defects , ( ii ) the same heavy fermi liquid is present in the samples containing the magnetic defects as in magnetically pure liv@xmath4o@xmath5 , and ( iii ) the influences of the magnetic defects and of the fermi liquid on the magnetization and nmr properties are separable . in the _ single crystals _
, somewhat different behaviors are observed , possibly due to a modification of the heavy fermi liquid , to a lack of separability of the relaxation effects due to the fermi liquid and the magnetic defects , to non - fermi liquid behavior of the conduction electrons , and/or to quantum fluctuations of finite - size magnetic defects ( magnetic droplets ) .
remarkably , the magnetic defects in the powder samples show evidence of spin freezing below @xmath7 k , whereas in the single crystals with similar magnetic defect concentration no spin freezing was found down to @xmath8 k. thus different types of magnetic defects and/or interactions between them appear to arise in the powders versus the crystals , possibly due to the substantially different synthesis conditions of the powders and crystals . .
And you have already written the first three sentences of the full article: liv@xmath9o@xmath10 is a rare @xmath11-electron heavy fermion system at low temperatures @xmath12 k.@xcite the low temperature linear electronic specific heat coefficient @xmath13 ( 0.42 j / mol k@xmath14 ) and pauli magnetic susceptibility @xmath15 ( @xmath16 @xmath17/mol ) are 180 and 310 times those of a free electron gas , respectively , assuming each vanadium atom contributes 1.5 free electrons .
the wilson ratio @xmath18 , which is the ratio of the enhancement factors of @xmath15 and @xmath13 , is equal to 1.7 , typical for a heavy fermion system.@xcite heavy fermion behavior was further confirmed by electrical resistivity measurements which show a @xmath19 dependence below 2 k with a large coefficient @xmath20 @xmath21 cm / k@xmath14.@xcite the @xmath22 and @xmath13 values approximately follow the kadowaki - woods relation , @xmath23 cm(mol k / j)@xmath14 , which holds for a variety of heavy fermion systems.@xcite despite continuous theoretical work , a detailed explanation of the heavy fermion behaviors in liv@xmath9o@xmath10 remains a challenge.@xcite @xmath6li nuclear magnetic resonance ( nmr ) was an important local probe in establishing the low temperature heavy fermion behavior in magnetically pure samples of liv@xmath9o@xmath10.@xcite the low temperature @xmath6li nuclear spin - lattice relaxation rate @xmath24 follows a korringa relation @xmath25 , with a coefficient @xmath26 s@xmath27k@xmath27 , which is 6000 times larger than in the non - heavy fermion isostructural superconducting@xcite compound liti@xmath9o@xmath10.@xcite the korringa ratio @xmath28k^2t_1t$ ] , where @xmath29 is the knight shift , @xmath30 and @xmath31 are the gyromagnetic ratios of the @xmath6li nuclear spin and the conduction electron spin , respectively , is equal to 0.7 , which is close to the value of unity expected for a free electron gas .
recently , we found that the low temperature @xmath6li nmr properties of polycrystalline liv@xmath9o@xmath10 are very sensitive to the presence of a small concentration....
Please generate the next two sentences of the article
|
however , in the sample with @xmath32 mol% , the @xmath33 showed a stretched exponential recovery @xmath37 $ ] , with the characteristic relaxation rate @xmath38 showing a peak at @xmath39 k. here @xmath40 is the stretching exponent with , in general , @xmath41 .
there was also a clear difference in the @xmath6li nmr spectrum in these two samples . at low temperatures @xmath42
|
10,747 |
Suppose that you have an abstract for a scientific paper: the partition function of the two - dimensional ising model with zero magnetic field on a square lattice with @xmath0 sites wrapped on a torus is computed within the transfer matrix formalism in an explicit step - by - step approach inspired by kaufman s work . however , working with two commuting representations of the complex rotation group so@xmath1 helps us avoid a number of unnecessary complications .
we find all eigenvalues of the transfer matrix and therefore the partition function in a straightforward way . .
And you have already written the first three sentences of the full article: since onsager s solution @xcite in the transfer matrix approach @xcite of the two - dimensional ising model @xcite with vanishing magnetic field and its subsequent simplification by kaufman @xcite , there have been a number of related as well as alternative solutions , see e.g. baxter s book on exactly solved models in statistical mechanics @xcite and references therein . among the transfer matrix solutions
are the ones by schultz , mattis and lieb , by thompson , by baxter and by stephen and mittag @xcite .
nevertheless , the author of this work feels that there is still room for a nice and straightforward solution ..
Please generate the next two sentences of the article
|
a much abbreviated version of this work , sketching only the new aspects may be found in @xcite , while here we give a self - contained account of our approach with all relevant details .
we study the two - dimensional ising model with zero magnetic field on a square lattice with @xmath2 rows and @xmath3 columns subject to toroidal boundary conditions .
|
10,748 |
Suppose that you have an abstract for a scientific paper: we show that quantum theory contains observables that are as incompatible as any probabilistic physical theory can have .
we define the joint measurability region of a probabilistic theory which describes the amount of added noise needed to make any pair of observables in the theory jointly measurable .
we then show that the joint measurability region of quantum theory is contained in the joint measurability region of any other probabilistic theory .
quantum theory has a number of important features not known in classical physics , ranging from the superposition and indeterminacy principles formulated by the pioneers to the more recently discovered no - cloning and no - broadcasting theorems .
it is an old problem to identify operationally significant properties of quantum theory that distinguish it from other probabilistic theories . in recent years
many features have been under intensive investigation from this perspective , including information processing @xcite , optimal state discrimination @xcite , entropy @xcite , purification @xcite and discord @xcite .
it has been found that some properties are quite generally valid in any non - classical ( no - signaling ) probabilistic theories while others are specifically quantum .
the existence of pairs of incompatible observables marks one of the most striking distinctions between quantum theory and classical physical theories .
there are many manifestations of incompatibility , perhaps the most famous being the heisenberg uncertainty principle @xcite . in this letter
we demonstrate that quantum theory contains observables that are as incompatible ( in a sense to be defined ) as observables in any probabilistic theory can be .
our aim is thus to compare quantum theory to other possible probabilistic physical theories .
we first need to set some minimal constraints .
a probabilistic theory is a framework that provides a description of physical systems in terms of states and observables with the following general properties : + ....
And you have already written the first three sentences of the full article: the authors wish to thank tom bullock for comments on an earlier version of this paper . t.h . and j.s .
acknowledge financial support from the academy of finland ( grant no ..
Please generate the next two sentences of the article
| |
10,749 |
Suppose that you have an abstract for a scientific paper: we have investigated the fluorescence emission in the near infrared from the air and its main components , nitrogen and oxygen .
the gas was excited by a @xmath0 electron beam and the fluorescence light detected by an ingaas photodiode , sensitive down to about @xmath1 .
we have recorded the emission spectra by means of a fourier transform infrared spectrometer .
the light yield was also measured by comparing the near infrared signal with the known ultraviolet fluorescence , detected by a si photodiode .
the possibility of using the near infrared fluorescence of the atmosphere to detect ultra - high - energy cosmic rays is discussed , showing the pros and the cons of this novel method .
air fluorescence , nitrogen fluorescence , oxygen fluorescence , near - infrared , cosmic - ray detection , ultra - high - energy cosmic rays .
And you have already written the first three sentences of the full article: the fluorescence of the nitrogen gas in the atmosphere in the visible ( vis ) and ultraviolet ( uv ) regions was independently proposed in the sixties of last century by greisen @xcite , delvaille et al .
@xcite , suga @xcite , and chudakov @xcite as a way to detect high energy showers created by cosmic rays impinging on the earth atmosphere .
nowadays the air fluorescence method is a well established technique used by the experiments hires @xcite , which is the continuation of the pioneering fly s eye experiment @xcite , auger @xcite , and by the telescope array project @xcite ..
Please generate the next two sentences of the article
|
the main emission of the fluorescence light is in the uv region between @xmath2 and @xmath3 .
the transparency of the atmosphere at those wavelength is limited by the presence of molecular oxygen and ozone , which absorb the uv photons . the rayleigh scattering , whose cross section scales as @xmath4 , and the mie scattering further reduce the number of photons which arrive at the detector .
|
10,750 |
Suppose that you have an abstract for a scientific paper: the formation scenarios for _ single _ low - mass ( @xmath0 ) white dwarfs include enhanced mass loss from a metal - rich progenitor star or a common envelope phase of a solar - like star with a close - in massive planet or a brown dwarf .
both scenarios suggest that low - mass white dwarfs may have planets . here
, we present a _ spitzer _ irac search for substellar and planetary mass companions to 14 low - mass white dwarfs .
one of our targets , hs 1653 + 7753 , displays near- and mid - infrared flux excess .
however , follow - up mmt observations show that this excess is due to a nearby resolved source , which is mostly likely a background object .
another target , pg 2257 + 162 , shows flux excess compatible with a late - type stellar companion .
we do not detect substellar companions to any of the remaining targets .
in addition , eight of these stars do not show any radial velocity variations , ruling out stellar mass companions including other white dwarfs .
we conclude that a significant fraction of the low - mass white dwarfs in our sample do not have stellar or massive brown dwarf companions . .
And you have already written the first three sentences of the full article: the fate of planetary systems around sun - like stars can be studied by finding planets around their white dwarf ( wd ) remnants .
wds are physically small ( @xmath1 ) , which sharply limits their luminosity in the infrared , where the planet spectrum peaks @xcite .
compared to main - sequence ( ms ) stars , the significant gain in contrast makes wds excellent targets for photometric searches for planetary companions ..
Please generate the next two sentences of the article
|
however , to this day , no planet detection around wds has been reported . _
spitzer _ irac imaging surveys by @xcite , @xcite , @xcite , and @xcite , and near - infrared imaging surveys by @xcite , @xcite , and @xcite were unsuccessful in finding planetary mass companions to wds with limits typically between 5 and @xmath2 .
|
10,751 |
Suppose that you have an abstract for a scientific paper: in the framework of a multiorbital hubbard model description of superconductivity , a matrix formulation of the superconducting pairing interaction that has been widely used is designed to treat spin , charge , and orbital fluctuations within a random phase approximation ( rpa ) . in terms of feynman diagrams , this takes into account particle - hole ladder and bubble contributions as expected .
it turns out , however , that this matrix formulation also generates additional terms which have the diagrammatic structure of vertex corrections .
here we examine these terms and discuss the relationship between the matrix - rpa superconducting pairing interaction and the feynman diagrams that it sums . .
And you have already written the first three sentences of the full article: despite considerable experimental and theoretical efforts over the last few decades , unconventional superconductivity remains one of the most interesting open puzzles in solid - state physics .
while it has been proposed that in some unconventional superconductors several interactions may be responsible for superconductivity , spin fluctuations are argued by a large fraction of the solid - state community to be the dominant mechanism driving cooper pairing in heavy - fermion systems , cuprates , two - dimensional organic charge - transfer salts and the iron - based superconductors @xcite .
such a statement is based on a few properties that have been found to be characteristic for these material classes like the fact that the superconducting phase is located in close vicinity to an antiferromagnetic ordered state and the phase transition can be easily tuned by application of pressure or charge doping @xcite ..
Please generate the next two sentences of the article
|
assuming spin , charge , and orbital fluctuations provide the dominant mechanism driving superconductivity , various theoretical approaches have been developed in the last few decades in order to predict superconducting gap functions , critical temperatures , and functional characteristics of thermodynamic quantities .
here we shall focus on the random phase approximation ( rpa ) for the hubbard model . in the single - orbital case on a three - dimensional cubic lattice this approach leads to a strong enhancement of the singlet coupling in the proximity of a spin - density - wave instability yielding to a @xmath0 symmetry of the gap function @xcite as observed , for instance , in the high - t@xmath1 cuprates @xcite .
|
10,752 |
Suppose that you have an abstract for a scientific paper: we consider @xmath0 hamiltonian systems whose ground states display symmetry protected topological order .
we show that ground states within the topological phase can not be connected with each other through locc between a bipartition of the system .
our claim is demonstrated by analyzing the entanglement spectrum and rnyi entropies of different physical systems providing examples for symmetry protected topological phases .
specifically , we consider spin-@xmath1 cluster - ising model and a class of spin@xmath2 models undergoing quantum phase transitions to the haldane phase .
our results provide a probe for symmetry - protected topological order . since the picture holds even at the system s _ local scale _ , our analysis can serve as as local experimental test for topological order . .
And you have already written the first three sentences of the full article: understanding topological order in extended systems is one of the major challenges in modern physics .
such an issue has immediate spinoff in condensed matter physics@xcite , but encompasses important aspects of quantum information as well@xcite .
topologically ordered systems are ( generically ) gapped systems characterized by a specific degeneracy of the ground states@xcite ..
Please generate the next two sentences of the article
|
the main attraction for quantum computation applications relays on the intrinsic robustness of such an order to external perturbations .
indeed such a property is nothing but a rephrasing that no local order parameter can be defined to characterize topologically ordered states ( elitzur theorem ) .
|
10,753 |
Suppose that you have an abstract for a scientific paper: we present near - infrared ( nir ) spectra , deep @xmath0 , @xmath1 and @xmath2 low - resolution images , and high - resolution images in @xmath0 and @xmath3 of the low - metallicity blue dwarf galaxy sbs 0335 - 052 .
these new nir data , together with optical and mid - infrared data from the literature , are used to constrain the properties and the star formation history of the galaxy .
the nir spectral characteristics and broadband colors of this galaxy are those of an extremely young starburst .
we find that the nir emission is dominated by star formation occuring in clusters younger than 5 myr ; no optically hidden star formation is revealed in our data .
we also find that a warm - dust component is necessary to explain the @xmath4 color , and is consistent with the mid - infrared spectral energy distribution .
finally , we quantify the possible contribution from an evolved stellar population . .
And you have already written the first three sentences of the full article: sbs 0335 - 052 ( izotov et al . 1990 ) is a blue compact dwarf ( bcd ) galaxy that , at an abundance of @xmath5 ( melnick et al .
1992 , izotov et al .
1997 ) , is the second lowest metallicity galaxy known after i zw 18 ..
Please generate the next two sentences of the article
|
sbs 0335 - 052 hosts an exceptionally powerful episode of star formation , and thuan et al .
( 1997 ) proposed , on the basis of hst observations , that the present burst is possibly the first star - forming episode in the history of the galaxy .
|
10,754 |
Suppose that you have an abstract for a scientific paper: spin - disorder resistivity of fe and ni and its temperature dependence are analyzed using noncollinear density functional calculations within the supercell method .
different models of thermal spin disorder are considered , including the mean - field approximation and the nearest - neighbor heisenberg model .
spin - disorder resistivity is found to depend weakly on magnetic short - range order . if the local moments are kept frozen at their zero - temperature values , very good agreement with experiment is obtained for fe , but for ni the resistivity at elevated temperatures is significantly overestimated .
agreement with experiment for fe is improved if the local moments are iterated to self - consistency .
the overestimation of the resistivity for paramagnetic ni is attributed to the reduction of the local moments down to @xmath0 .
overall , the results suggest that low - energy spin fluctuations in fe and ni are better viewed as classical rotations of local moments rather than quantized spin fluctuations that would require an @xmath1 correction . .
And you have already written the first three sentences of the full article: electron scattering off of spin fluctuations in magnetic metals results in an `` anomalous '' contribution to electric resistivity.@xcite the analysis of this spin - disorder resistivity ( sdr ) is of interest because it can provide material - specific information on the character of spin fluctuations which is not easily accessible by other means .
scattering on spin disorder is also an important factor degrading the performance of magnetoresistive nanostructures in spintronic devices .
the magnitude of the spin - disorder contribution to resistivity is comparable to the phonon contribution near and above the curie temperature @xmath2.@xcite ( magnetic scattering amplitudes have no small parameter unless the local moments are small . ) it is usually assumed that sdr is constant well above @xmath2 . in this region matthiessen s rule is valid , and the phonon contribution can be fitted to the bloch - grneisen formula . the excess resistivity in the whole temperature range may be attributed to spin disorder,@xcite although one may expect deviations from matthiessen s rule at low temperatures where transport is carried by weakly interacting spin channels.@xcite in addition , it was argued that in some cases ( such as ni ) spin disorder may change the character of states on the fermi level and thereby appreciably change the phonon contribution itself.@xcite many authors have studied sdr theoretically using the @xmath3-@xmath4 model hamiltonian.@xcite in this approach the @xmath5 shells in transition metals ( or @xmath6 shells in rare earth metallic magnets ) are assumed to be localized at atomic sites and partially filled , forming magnetic moments @xmath7 that are coupled to the current - carrying conduction electrons by exchange interaction @xmath8 , where @xmath9 is the local @xmath3-@xmath4 exchange coupling constant and @xmath10 the spin - density operator of the conduction electrons at site @xmath11 ..
Please generate the next two sentences of the article
|
thermal fluctuations of the @xmath4-electron spins generate an inhomogeneous exchange potential ; in the born approximation the sdr is then determined by the conduction electron band structure and the spin - spin correlation functions of @xmath4-electron spins.@xcite if the scattering is approximated as being elastic , only equal - time spin correlators have to be considered .
further , if the mean - field approximation ( mfa ) is used for @xmath5 spin statistics , the sdr behaves as @xmath12 $ ] , where @xmath13 is the magnetization at temperature @xmath14 and @xmath15 .
|
10,755 |
Suppose that you have an abstract for a scientific paper: we present numerical results on a complex dynamical model for the aggregation of many individual rankings of @xmath0 alternatives by the pairwise majority rule under a deliberative scenario .
agents are assumed to interact when the kemeny distance between their rankings is smaller than a range @xmath1 .
the main object of interest is the probability that the aggregate ( social ) ranking is transitive as a function of the interaction range .
this quantity is known to decay fast as @xmath0 increases in the non - interacting case . here
we find that when @xmath2 such a probability attains a sharp maximum when the interaction range is sufficiently large , in which case it significantly exceeds the corresponding value for a non - interacting system .
furthermore , the situation improves upon increasing @xmath0 .
a possible microscopic mechanism leading to this counterintuitive result is proposed and investigated . social choice , condorcet paradox , pairwise majority rule 89.65.-s , 05.10.-a , 02.50.ey .
And you have already written the first three sentences of the full article: the aggregation of many individual preferences into a single , `` social '' preference is a long - studied problem in mathematical social sciences which has more recently also been considered from a statistical mechanics viewpoint . here by `` preference ''
we mean simply a ranking of say @xmath0 objects , i.e. a complete ordering e.g. from the favorite downwards .
a minimal consistency requirement for preferences is that they should be transitive , i.e. if @xmath3 is preferred to @xmath4 and @xmath4 to @xmath5 , then @xmath3 should be preferred to @xmath5 ..
Please generate the next two sentences of the article
|
it is however well known that as soon as @xmath0 exceeds 2 the construction of the aggregate preference runs into the condorcet problem @xcite : starting from transitive individual preferences , the social preference may turn out to be intransitive , i.e. contain a cycle of the type @xmath6 ( meaning a preferred to b etc . ) .
the probability with which an intransitive ranking emerges from random individual preferences ( ` impartial culture assumption ' @xcite ) has been studied in the mathematical economics literature in the past @xcite . remarkably , this bottleneck is present to different degrees for all aggregation methods one considers and can be removed only at the cost of loosening some of the requirements that a social choice should satisfy . among the different aggregation methods ,
|
10,756 |
Suppose that you have an abstract for a scientific paper: we analyze a model quantum dynamical system subjected to periodic interaction with an environment , which can describe quantum measurements . under the condition of strong classical chaos and strong decoherence due to large coupling with the measurement device , the spectra of the evolution operator exhibit an universal behavior .
a generic spectrum consists of a single eigenvalue equal to unity , which corresponds to the invariant state of the system , while all other eigenvalues are contained in a disk in the complex plane .
its radius depends on the number of the kraus measurement operators , and determines the speed with which an arbitrary initial state converges to the unique invariant state .
these spectral properties are characteristic of an ensemble of random quantum maps , which in turn can be described by an ensemble of real random ginibre matrices .
this will be proven in the limit of large dimension . .
And you have already written the first three sentences of the full article: time evolution of an isolated quantum system can be described by unitary operators .
quantum dynamics corresponds then to an evolution in the space of quantum pure states , since a given initial state @xmath0 is mapped into another pure state @xmath1 , where @xmath2 . here
@xmath3 represents a hermitian hamiltonian of the system and the time @xmath4 is set to unity ..
Please generate the next two sentences of the article
|
if the underlying classical dynamics is chaotic the hamiltonian @xmath3 or the evolution operator @xmath5 can be mimicked by ensembles of random unitary matrices @xcite . in particular , spectral properties of an evolution operator of a deterministic quantum chaotic system coincide with predictions obtained for the dyson ensembles of random unitary matrices @xcite .
the symmetry properties of the system determine which ensemble of matrices is applicable .
|
10,757 |
Suppose that you have an abstract for a scientific paper: high - intensity photon beams can provide for a viable probe for many particles of standard model extensions .
this workshop contribution briefly reviews the status of the second stage of the any light particle search ( alps - ii ) at desy , an experiment of the light - shining - through - a - wall type , as well as an idea to test asymptotically safe quantum gravity in a photon - scattering experiment . .
And you have already written the first three sentences of the full article: several considerations ( e.g. , uv - completions for the standard model ) and observations ( e.g. , dark matter ) lead us to assume the existence of particles beyond the standard model . in order to have evaded detection so far , such new particles can be either very heavy , or rather light ( e.g. , at sub - ev scale ) if they have extremely small coupling to known particles @xcite .
the most renowned example of such proposed weakly interacting slim particles , `` wisps '' for short , is arguably the axion @xcite , which is a consequence of the peccei - quinn solution to the strong cp - problem .
in addition , strong interest has emerged recently for so - called axion-_like _ particles ( alps ) , whose mass - coupling relation is relaxed compared to the qcd axion : alps can , e.g. , appear in intermediate string scale scenarios @xcite , and constitute dark matter @xcite ..
Please generate the next two sentences of the article
|
moreover they could explain yet puzzling observations in some astrophysical processes such as anomalous white dwarf cooling @xcite and the transmissibility of the universe to high - energetic photons @xcite .
further wisps can be particles of hidden sectors in string- and field - theoretic extensions of the standard model , see , e.g. , @xcite : particularly hidden photons ( hps ) , i.e. , gauge bosons of an extra u(1 ) gauge group as well hidden sector matter . the latter can acquire an electromagnetic fractional charge and thus can constitute so - called minicharged particles ( mcps ) , see @xcite for an overview .
|
10,758 |
Suppose that you have an abstract for a scientific paper: the maximal rate for non - square complex orthogonal designs ( cods ) with @xmath0 transmit antennas is @xmath1 if @xmath0 is even and @xmath2 if @xmath0 is odd , which are close to @xmath3 for large values of @xmath4 a class of maximal rate non - square cods have been constructed by liang ( ieee trans .
inform .
theory , 2003 ) and lu et .
al .
( ieee trans .
inform .
theory , 2005 ) have shown that the decoding delay of the codes given by liang , can be reduced by @xmath5 when number of transmit antennas is a multiple of @xmath6 .
adams et .
al .
( ieee trans .
inform .
theory , 2007 ) have shown that the designs of liang are of minimal - delay for @xmath0 equal to @xmath7 and @xmath8 modulo 4 and that of lu et.al .
are of minimal delay when @xmath0 is a multiple of @xmath9 however , these minimal delays are large compared to the delays of the rate @xmath10 non - square cods constructed by tarokh et al ( ieee trans .
inform .
theory , 1999 ) from rate-@xmath7 real orthogonal designs ( rods ) . in this paper
, we construct a class of rate-@xmath10 non - square cods for any @xmath0 with the decoding delay equal to @xmath5 of that of the delay of the rate-1/2 codes given by tarokh et al .
this is achieved by giving first a general construction of rate-1 square real orthogonal designs ( rods ) which includes as special cases the well known constructions of adams , lax and phillips and geramita and pullman , and then making use of it to obtain the desired rate-@xmath3 non - square cod . for the case of 9 transmit antennas ,
our rate-@xmath3 cod is shown to be of minimal - delay .
the proposed construction results in designs with zero entries which may have high peak - to - average power ratio ( papr ) and it is shown that by appropriate postmultiplication , a design with no zero entries can be obtained with no change in the code parameters . .
And you have already written the first three sentences of the full article: there are several definitions of orthogonal designs ( ods ) in the literature @xcite the well known being as given in @xcite : [ cod ] a complex orthogonal design ( cod ) @xmath11 ( in short @xmath12 ) for @xmath0 transmit antennas is defined as a @xmath13 matrix such that ( i ) the nonzero entries of @xmath12 are the complex variables @xmath14 and their conjugates and ( ii ) @xmath15 where @xmath16 stands for the complex conjugate transpose and @xmath17 is the @xmath18 identity matrix .
the matrix @xmath12 is also said to be a @xmath19 $ ] cod and its rate in complex symbols per channel use is @xmath20 when @xmath21 are real variables , the designs are called real orthogonal design ( rod ) . space - time block codes ( stbcs ) from cods have been widely studied for square designs , i.e. , @xmath22 since they correspond to minimum decoding delay codes for co - located multiple - antenna coherent communication systems .
however , non - square designs naturally appear and important in the following situations . 1 . in coherent co - located mimo systems , for a specified number of transmit antennas , non - square designs can give much higher rate than the square designs @xcite ..
Please generate the next two sentences of the article
|
2 . in non - coherent mimo systems with non - differential detection , non - square designs with @xmath23 lead to low decoding complexity stbcs @xcite .
space - time - frequency codes can be viewed as non - square designs @xcite .
|
10,759 |
Suppose that you have an abstract for a scientific paper: we examine the consequences of a model for the circulation of solids in a protoplanetary nebula in which aerodynamic drag is counterbalanced by the recycling of material to the outer disc by a protostellar outflow or a disc wind .
this population of circulating dust eventually becomes unstable to the formation of planetesimals by gravitational instability , and results in the ultimate deposition of @xmath0 3050 @xmath1 in planetesimals on scales @xmath2 .
such a model may provide an appropriate justification for the approximately power law initial conditions needed to reproduce observed planetary systems by in situ assembly .
[ firstpage ] accretion discs planets and satellites : formation protoplanetary discs .
And you have already written the first three sentences of the full article: the detection of planets orbiting other stars has revealed a great diversity of both planetary mass and location , including several populations which have no analogue in our own solar system .
of particular interest is the discovery of substantial numbers of sub - jovian planets with orbital periods shorter than that of mercury , using both the radial velocity and transit techniques ( howard et al .
2010 ; mayor et al . 2011 ; borucki et al ..
Please generate the next two sentences of the article
|
2011 ; batalha et al .
2013 ) .
|
10,760 |
Suppose that you have an abstract for a scientific paper: we study the conditions under which an overdamped regime can be attained in the dynamic evolution of a quantum field configuration . using a real - time formulation of finite temperature field theory ,
we compute the effective evolution equation of a scalar field configuration , quadratically interacting with a given set of other scalar fields .
we then show that , in the overdamped regime , the dissipative kernel in the field equation of motion is closely related to the shear viscosity coefficient , as computed in scalar field theory at finite temperature .
the effective dynamics is equivalent to a time - dependent ginzburg - landau description of the approach to equilibrium in phenomenological theories of phase transitions .
applications of our results , including a recently proposed inflationary scenario called `` warm inflation '' , are discussed .
pacs number(s ) : 98.80 cq , 05.70.ln , 11.10.wx in press physical review d , 1998 .
And you have already written the first three sentences of the full article: kinetic equations describe the time evolution of a certain chosen set of physical variables .
the choice of physical variables in principle is arbitrary , but often in practice is governed by the measurement of interest .
typical examples are the order parameter of a complex system or the coordinate of a brownian particle in a heat reservoir ..
Please generate the next two sentences of the article
|
the kinetic approach is usually implemented through a proper separation of the microscopic equations of motion of the chosen physical variables into regular and random parts .
an averaging over the random part then generates the effective partition function for the regular part .
|
10,761 |
Suppose that you have an abstract for a scientific paper: the absolute muon flux between 20 and 3000 is measured with the l3 magnetic muon spectrometer for zenith angles ranging from @xmath0 to @xmath1 . due to the large exposure of about 150 m@xmath2srd , and the excellent momentum resolution of the l3 muon chambers , a precision of 2.3% at 150 in the vertical direction is achieved .
the ratio of positive to negative muons is studied between 20 and 500 , and the average vertical muon charge ratio is found to be 1.285 @xmath3 0.003 ( stat . ) @xmath3 0.019 ( syst . ) . _
the l3+c group dedicates this publication to the late bianca monteleoni . _ .
And you have already written the first three sentences of the full article: atmospheric muons are among the final products of cosmic ray induced air - showers .
the absolute muon flux and its momentum dependence are mainly determined by the flux of nucleons entering the atmosphere and the inclusive meson production cross sections in high - energy hadronic interactions .
the ratio of the fluxes of positive to negative muons , denoted as charge ratio in the following , reflects the proton to neutron ratio at the top of the atmosphere , folded with the production and decay spectra of charged pions and kaons . while the knowledge of the primary cosmic ray spectrum below a few 100 has improved considerably in the recent past @xcite.
Please generate the next two sentences of the article
|
, large uncertainties still exist in the primary energy range between 0.1 and 500 responsible for the production of secondaries with momenta in the range under study here .
moreover , the details of high energy hadronic interactions still lack theoretical understanding and there is little experimental data in the relevant energy and phase space regions @xcite .
|
10,762 |
Suppose that you have an abstract for a scientific paper: we present a class of models with radiative neutrino mass and stable dark - matter candidates .
neutrino mass is generated by a one - loop diagram with the same topography as ma s 2006 proposal ( which used an inert scalar - doublet and singlet fermion ) .
we generalize this approach and determine all variants with new fields no larger than the adjoint representation .
when the neutrino mass diagram contains a majorana mass insertion there are two possibilities , both of which are known .
if the mass insertion is of the dirac type there are seven additional models , two of which are excluded by direct - detection experiments .
the other five models are also constrained , such that only scalar dark - matter is viable .
there are cases with an inert singlet , an inert doublet , and an inert triplet , providing a natural setting for inert @xmath0-tuplet models of dark matter , with the additional feature of achieving radiative neutrino mass .
we show that some of the models admit a simple explanation for the ( requisite ) discrete symmetry , and briefly discuss cases with representations larger than the adjoint , which can admit a connection to the astrophysical gamma - ray signal . a class of inert n - tuplet models with radiative neutrino mass and dark matter + sandy s. c. law@xmath1 and kristian l. mcdonald@xmath2 + * department of physics , national cheng - kung university , + tainan 701 , taiwan + @xmath3 arc centre of excellence for particle physics at the terascale , + school of physics , the university of sydney , nsw 2006 , australia + .
And you have already written the first three sentences of the full article: the experimental evidence for neutrino mass , acquired in recent decades , provides concrete evidence for physics beyond the standard model ( sm ) ( see e.g. @xcite ) .
although the requisite new degrees of freedom can not yet be determined it is clear that additional particles are likely to exist , in order to generate the masses .
similarly , there is by now a large amount of evidence for an additional galactic constituent , an unknown substance referred to as dark matter ( see e.g. @xcite ) ..
Please generate the next two sentences of the article
|
this may or may not require new degree s of freedom , but the hypothesis that the dark matter is comprised of a stable ( or long lived ) new particle species provides a simple explanation for this observed feature of the universe . given that these two indicators for beyond - sm physics can be explained by extending the particle spectrum of the sm , it is natural to ask if the requisite new particles can be related .
could the mechanism of neutrino mass be related to the existence of a stable dark - matter candidate ?
|
10,763 |
Suppose that you have an abstract for a scientific paper: it is known that if @xmath0 is a connected simple graph , then @xmath1 is hamiltonian ( in fact , hamilton - connected ) . a simple graph is @xmath2-ordered hamiltonian if for any sequence @xmath3 , @xmath4 , , @xmath5 of @xmath2 vertices there is a hamiltonian cycle containing these vertices in the given order . in this paper , we prove that @xmath6 is @xmath2-ordered hamiltonian for a connected graph @xmath0 on at least @xmath2 vertices .
we further show that if @xmath0 is connected , then @xmath7 is 4-ordered hamiltonian and that if @xmath0 is hamiltonian , then @xmath1 is 5-ordered hamiltonian .
we also give bounds on the smallest power @xmath8 such that @xmath9 is @xmath2-ordered hamiltonian for @xmath10 and @xmath11 .
_ dedicated to pavlo pylyavskyy on the occasion of his 21st birthday . _ .
And you have already written the first three sentences of the full article: the concept of @xmath2-ordered hamiltonian graphs has been recently introduced by ng and schultz @xcite .
a simple graph @xmath0 is @xmath2-_ordered _ ( resp .
@xmath2-_ordered hamiltonian _ ) if for any sequence @xmath3 , @xmath4 , .
Please generate the next two sentences of the article
|
, @xmath5 of @xmath2 vertices of @xmath0 there is a cycle ( resp . a hamiltonian cycle ) in @xmath0 containing these vertices in the given order .
note that being @xmath12-ordered hamiltonian is equivalent to being hamiltonian .
|
10,764 |
Suppose that you have an abstract for a scientific paper: in the context of the conjectured ads - cft correspondence of string theory , we consider a class of asymptotically black holes whose conformal boundary consists of a _ single _ connected component , identical to the conformal boundary of space . in a simplified model of the boundary theory
, we find that the boundary state to which the black hole corresponds is pure , but this state involves correlations that produce thermal expectation values at the usual hawking temperature for suitably restricted classes of operators .
the energy of the state is finite and agrees in the semiclassical limit with the black hole mass .
we discuss the relationship between the black hole topology and the correlations in the boundary state , and speculate on generalizations of the results beyond the simplified model theory .
= 10000 .
And you have already written the first three sentences of the full article: black holes and related classical solutions are a topic of long - standing interest in string theory @xcite .
their study has shed light on old questions @xcite in black hole physics ( see e.g. @xcite ) as well as dualities @xcite and other stringy issues @xcite .
indeed , it was an investigation of black holes that first lead to maldacena s conjecture @xcite ( based on earlier work , e.g. @xcite ) relating string theory in asymptotically anti - de sitter space to a conformal field theory on the boundary at spatial infinity . for evidence supporting this conjecture , see @xcite ..
Please generate the next two sentences of the article
|
it is therefore natural to investigate asymptotically anti - de sitter ( ads ) black holes in light of maldacena s conjecture .
previous work @xcite has analyzed the ( 2 + 1)-dimensional btz black holes @xcite in this way , using the fact that the classical black hole solutions are certain quotients of ads@xmath0 to identify associated states in the conformal field theory ( cft ) .
|
10,765 |
Suppose that you have an abstract for a scientific paper: optics has proved a fertile ground for the experimental simulation of quantum mechanics .
most recently , optical realizations of @xmath0-symmetric quantum mechanics have been shown , both theoretically and experimentally , opening the door to international efforts aiming at the design of practical optical devices exploiting this symmetry . here ,
we focus on the optical @xmath0-symmetric dimer , a two - waveguide coupler were the materials show symmetric effective gain and loss , and provide a review of the linear and nonlinear optical realizations from a symmetry based point of view .
we go beyond a simple review of the literature and show that the dimer is just the smallest of a class of planar @xmath1-waveguide couplers that are the optical realization of lorentz group in 2 + 1 dimensions .
furthermore , we provide a formulation to describe light propagation through waveguide couplers described by non - hermitian mode coupling matrices based on a non - hermitian generalization of ehrenfest theorem . .
And you have already written the first three sentences of the full article: the desire to create an optical directional coupler , a device composed by parallel optical waveguides close enough that leaked energy is transferred between them , led to the exploration of waveguide creation in semi - conductors via proton bombardment @xcite . at the time , power losses played an interesting role and the nascent mode coupling theory @xcite allowed the theoretical description of linear loses in such devices @xcite , @xmath2,\end{aligned}\ ] ] where the real numbers @xmath3 and @xmath4 are the effective linear loss , identical in all implanted waveguides , and the effective waveguide coupling strength , also indentical for the whole system , in that order .
this , to the best of our knowledge , was the first theoretical description of an experimental @xmath1-waveguide coupler including losses in the form of a schrdinger - like equation involving a non - hermitian hamiltonian .
almost twenty years later , the desire to create an intensity dependent switch working at low power levels took another team of researchers to explore twin core nonlinear couplers with gain and loss ..
Please generate the next two sentences of the article
|
again , coupled mode theory allowed the description of such devices @xcite , @xmath5 where we have kept the notation used before and introduce the effective real part of the refractive index , @xmath6 , and the real function @xmath7 that describes an effective kerr nonlinearity induced change in the refractive index of the @xmath8th core , positive for self - focusing and negative for self - defocusing materials . at this point in history , there existed experimental and theoretical work describing an optical dimer where the waveguides present effective loss and gain and a nonlinearity but a little something was missing .
a couple of years later , a theory exploring a particular type of non - hermitian hamiltonians with real spectra was brought forward in quantum mechanics @xcite .
|
10,766 |
Suppose that you have an abstract for a scientific paper: we have obtained new deep optical and near - infrared images of the field of the _ radio - loud _
quasar 1335.8@xmath02834 at @xmath1 where an excess in the surface number density of galaxies was reported by hutchings et al .
[ aj , 106 , 1324 ] from optical data .
we found a significant clustering of objects with very red optical - near infrared colors , @xmath2 and @xmath3 near the quasar .
the colors and magnitudes of the reddest objects are consistent with those of old ( 12 gyr old at @xmath4 ) passively - evolving elliptical galaxies seen at @xmath5 , clearly defining a ` red envelope ' like that found in galaxy clusters at similar or lower redshifts .
this evidence strongly suggests that the quasar resides in a moderately - rich cluster of galaxies ( richness - class @xmath6 ) .
there is also a relatively large fraction of objects with moderately red colors ( @xmath7 ) which have a distribution on the sky similar to that of the reddest objects .
they may be interpreted as cluster galaxies with some recent or on - going star formation . .
And you have already written the first three sentences of the full article: clusters of galaxies from low to high redshift provide a unique opportunity to trace back the evolution of galaxies in dense environments .
detailed studies of elliptical galaxies in nearby and intermediate redshift clusters showed that their photometric properties are homogeneous and evolve only mildly with redshift at @xmath8 .
this is consistent with the so - called ` passive evolution ' , namely the change of the photometric properties of elliptical galaxies by the aging of their stars only , with a formation epoch of at least @xmath9 gyr ago ( bower , lucey & ellis 1992 ; aragn - salamanca et al ..
Please generate the next two sentences of the article
|
1993 ; ellis et al . 1997
; dickinson 1997b ; stanford , eisenhardt , & dickinson 1997 ) . on the other hand , some s0 and spiral galaxies seem to experience faster evolution ( e.g. , dressler et al .
|
10,767 |
Suppose that you have an abstract for a scientific paper: the asymptotic shape of randomly growing radial clusters is studied .
we pose the problem in terms of the dynamics of stochastic partial differential equations .
we concentrate on the properties of the realizations of the stochastic growth process and in particular on the interface fluctuations .
our goal is unveiling under which conditions the developing radial cluster asymptotically _ weakly _ converges to the concentrically propagating spherically symmetric profile or either to a symmetry breaking shape .
we demonstrate that the long range correlations of the surface fluctuations obey a self - affine scaling and that scale invariance is achieved by means of the introduction of three critical exponents .
these are able to characterize the large scale dynamics and to describe those regimes dominated by system size evolution .
the connection of these results with mathematical morphogenetic problems is also outlined . .
And you have already written the first three sentences of the full article: the building blocks of mathematical morphogenesis were put several decades ago in the seminal works of thompson @xcite and turing @xcite . a particularly relevant problem in this context is the examination of the properties relating to the architecture of cell colonies , as already noted and investigated by eden @xcite . at some basic underlying level , one could say that turing and eden shared the goal of understanding how a macroscopic structure , in particular one breaking the initial homogeneity , could arise out of a multiplicity of simple interactions . in the introduction of @xcite
one can read turing thoughts on how a structure composed by randomly and isotropically proliferating cells could or could not break the initial spherical symmetry .
but then his approach moved to the use of reaction diffusion equations and to the search of a deterministic mechanism , the currently well known turing instability , able to give rise to pattern formation . on the other hand ,.
Please generate the next two sentences of the article
|
eden focused his interest on the evolution of a pure growth process .
he concentrated on a probabilistic abstraction of a developing cell colony and studied stochastic symmetry breaking concomitant to growth .
|
10,768 |
Suppose that you have an abstract for a scientific paper: non - fermi liquid ( nfl ) state represents an ensemble of incoherent quantum fluids arising from the coupling between electrons and massless ( critical ) excitations , and is separated by phase boundary from the quasiparticle behavior in the fermi - liquid ( fl ) theory .
here we show that such sharp distinction breaks down in cuprates , and that both nfl and fl states coexists in different momentum ( @xmath0 ) regions at all dopings .
their coexistence originates from the strong anisotropy in the many - body self - energy , arising from dispersive density - density fluctuations . the self - energy attains maxima ( nfl - like ) in the region where density degeneracy is optimum ( antinodal region ) , while the nodal region remains fl - like at all dopings .
we attribute the global nfl / fl behavior via the calculation of the resistivity - temperature exponent ( @xmath1 ) .
surprisingly , we find that the entire brillouin zone becomes neither fully incoherent , nfl - like even at optimal doping with @xmath2 , nor fully fl - like even at overdoping ( @xmath3 ) .
as density degeneracy increases in different materials with increasing superconducting @xmath4 , @xmath1 decreases ; providing a microscopic explanation to this intriguing relationship .
all results , including coexistence of nfl- and fl - self - energies in the @xmath0-space , and their doping , materials dependencies are compared with available experimental data , followed by definite predictions for future studies . .
And you have already written the first three sentences of the full article: non - fermi liquid ( nfl ) or strange metal phase is often observed to precede many correlated phases , such as antiferro- or ferromagnetism , and unconventional superconductivity.@xcite it is characterized by deviation from the well - defined fermi - liquid ( fl ) predictions , such as the resistivity - temperature exponent ( @xmath1 ) being @xmath51 , while @xmath6 is expected from the fl theory .
systematic studies in various superconducting families have also revealed that superconducting transition temperature ( @xmath4 ) increases as the exponent @xmath1 decreases , i.e. , as the system deviates farther from the fl behavior.@xcite therefore , nfl state is considered an important problem towards the understanding of unconventional superconductivity . in the phase diagram , nfl state
is often seen to arise near the boundary between an order phase and the fl state , where superconductivity is optimized.@xcite yet , considerable counter - examples are also present where a nfl phase is present without a quantum phase transition@xcite or superconductivity.@xcite therefore , it has remained a ` chicken - and - egg ' type problem whether a quantum critical point drives the nfl state or vice versa , and how they conspire into superconductivity . to definitely answer this issue.
Please generate the next two sentences of the article
|
, one can approach the nfl state from the fl regime .
the transition from the fl to nfl state is very adiabatic , i.e , the resistivity exponent @xmath1 _ continuously _ changes from 2 ( fl ) to 1 or even below 1 in the nfl state at a given temperature .
|
10,769 |
Suppose that you have an abstract for a scientific paper: in this paper we analyze the peculiar radio structure observed across the central region of the galaxy cluster abell585 ( @xmath0 ) . in the low - resolution radio maps ,
this structure appears uniform and diffuse on angular scales of @xmath1 , and is seemingly related to the distant ( @xmath2 ) radio quasar b30727 + 409 rather than to the cluster itself .
however , after a careful investigation of the unpublished archival radio data with better angular resolution , we resolve the structure into two distinct arcmin - scale features , which resemble typical lobes of cluster radio galaxies with no obvious connection to the background quasar .
we support this conclusion by examining the spectral and polarization properties of the features , demonstrating in addition that the analyzed structure can hardly be associated with any sort of a radio mini - halo or relics of the cluster . yet at the same time we are not able to identify host galaxies of the radio lobes in the available optical and infrared surveys .
we consider some speculative explanations for our findings , including gravitational wave recoil kicks of smbhs responsible for the lobes formation in the process of merging massive ellipticals within the central parts of a rich cluster environment , but we do not reach any robust conclusions regarding the origin of the detected radio features .
[ firstpage ] radiation mechanisms : non - thermal galaxies : active galaxies : clusters : individual : abell585 galaxies : jets quasars : individual : b30727 + 409 radio continuum : galaxies .
And you have already written the first three sentences of the full article: during merging processes leading to the formation of clusters of galaxies , large amounts of gravitational energy are released on timescales of the order of @xmath3gyr .
most of this energy is contained in hot ( temperatures @xmath4kev ) x - ray emitting plasma which constitutes , along with the dark matter , the dominant fraction of the intracluster medium ( icm ; e.g. , @xcite ) .
in addition to the thermal gas , however , @xmath5 g magnetic fields and ultrarelativistic electrons are present within the icm as well , manifesting most clearly in extended diffuse radio structures such as giant and mini radio halos in the central parts of clusters , or radio relics at cluster peripheries ( see the reviews by @xcite ) ..
Please generate the next two sentences of the article
|
these non - thermal constituents of the icm are believe to be related to the energy dissipation processes enabled by large - scale shocks formed at the outskirts of merging systems , and/or turbulence driven by various mechanisms at early post - merger stages of a cluster lifetime .
the presence of ( or rather the amount of ) hadronic cosmic rays in the diffuse cluster environment is still an open question , being currently probed with new - generation @xmath6-ray instruments ( see , e.g. , @xcite ) . besides
|
10,770 |
Suppose that you have an abstract for a scientific paper: # 6 plus 1000pt minus 1000pt # 1 # 1= to # 1#2#1#2 # 1#2#3 ^ 2 # 1#2 # 3 # 1#1| # 1| # 1 # 1#1 # 1/ # 1| # 1| # 1#1^ = # 1#2#3 @xmath0 # 1#2#3#4 @xmath1 # 1#2 @xmath2 # 1#2#3#4#5 @xmath3 # 1 # 1@xmath4 = 1.5ex plus 1pt = 11 addtoresetequationsection normalsizesetsizexiipt plus3pt minus3pt@ plus3pt plus3.5pt minus0pt twosidetrue
@=12 0.0 in 0.0 in 6.0 in 8.5 in .7 cm -1 cm .75 in = 11 .
And you have already written the first three sentences of the full article: # 1 ps . @headings oddfootevenfoot oddhead evenheadoddhead # # 1 ps .
@headings = 12 # 1@xmath4
= 11 # 1 ps . @headings oddfootevenfoot oddhead evenheadoddhead # # 1 ps ..
Please generate the next two sentences of the article
|
@headings = 12
= 11 = 12 # 1#2#3_phys .
|
10,771 |
Suppose that you have an abstract for a scientific paper: diffraction of a surface wave on a rectangular wedge with impedance faces is studied using the sommerfeld - malyuzhinets technique .
an analog of landau s bypass rule in the theory of plasma waves is introduced for selection of a correct branch of the sommerfeld integral , and the exact solution is given in terms of imaginary error function .
the formula derived is valid both in the near - field and far - wave zones .
it is shown that a diffracted surface wave is completely scattered into freely propagating electromagnetic waves and neither reflected nor transmitted surface waves are generated in case of bare metals which have positive real part of surface impedance .
the scattered waves propagate predominantly at a grazing angle along the direction of propagation of the incident surface wave and mainly in the upper hemisphere regarding the wedge face .
the profile of radiated intensity is nonmonotonic and does not resemble the surface wave profile which exponentially evanesces with the distance from the wedge face .
comparison with experiments carried out in the terahertz spectral range at novosibirsk free electron laser has shown a good agreement of the theory and the experiments . .
And you have already written the first three sentences of the full article: plasmonics is now a very rapidly developing field of activity , and advancement to the mid- and far - infrared ( terahertz ) ranges of frequencies is one of the main streams in photonics @xcite .
our interest in this subject has arisen from discussions of the results of experiments on propagation of surface plasmon polaritons ( spps ) along gold - zns - air interfaces @xcite , which were carried out at novosibirsk free electron laser facility @xcite in the terahertz spectral range . for spps not to be disturbed by any material probe , plasmon - polariton characteristics were studied indirectly via sensing of the electromagnetic field in the space behind the tail facet of samples . in the experiments , the profile of radiated intensity is non - monotonic and does not resemble a surface wave profile which exponentially evanesces with the distance from the wedge face .
a maximum of the radiation intensity is observed at some distance from the surface plane whereas a maximum of the surface wave field should be located at the wedge surface ..
Please generate the next two sentences of the article
|
these discrepancies had initiated search for theoretical explanation which has led us to the theory developed by g.d .
malyuzhinets in the 1950s .
|
10,772 |
Suppose that you have an abstract for a scientific paper: we report giant meterwave radio telescope ( gmrt ) continuum observations of six nearby normal galaxies at 333 mhz .
the galaxies are observed with angular resolutions better than @xmath0 ( corresponding to a linear scale of about 0.4 1 kpc ) .
these observations are sensitive to all the angular scales of interest , since the resolution of the shortest baseline in gmrt is greater than the angular size of the galaxies .
further , for five of these galaxies we show that at 333 mhz , the mean thermal fraction is less than 5% . using archival data at about 1 ghz , we estimate the mean thermal fraction to be about 10% at that frequency .
we also find that the nonthermal spectral index is generally steeper in regions with low thermal fraction and/or located in the outer parts of the galaxy . in regions of high thermal fraction , the nonthermal spectral index is flatter , and has a narrow distribution peaking at @xmath1 with a spread of 0.16 , putting stringent constraints on the physical conditions for generation , diffusion and energy losses of cosmic ray electrons at scales of @xmath2 1 kpc .
[ firstpage ] galaxies : spiral galaxies : individual ( ngc 1097 , ngc 3034 , ngc 4736 , ngc 5055 , ngc 5236 , ngc 6946 ) ( ism : ) cosmic rays ( ism : ) regions techniques : interferometric techniques : image processing .
And you have already written the first three sentences of the full article: [ cols="<,^,^,^,^,^,^,^,^ " , ]
the nonthermal spectral index @xmath3 , is the main parameter of interest because it is used to model cre generation and propagation .
however , it is not possible to measure it directly ..
Please generate the next two sentences of the article
|
the quantity which is measured is the total spectral index @xmath4 which is contaminated by thermal free - free emission .
this contamination is significant for spatially resolved regions of the galaxy where the thermal fraction , where , @xmath5 is the flux density of the thermal emission . in the text
|
10,773 |
Suppose that you have an abstract for a scientific paper: experiments of pain with human subjects are difficult , subjective , and ethically constrained .
since the molecular mechanisms of pain transduction are reasonably conserved among different species , these problems are partially solved by the use of animal models .
however , animals can not easily communicate to us their own pain levels .
thus progress depends crucially on our ability to quantitatively and objectively infer the perceived level of noxious stimuli from the behavior of animals .
here we develop a quantitative model to infer the perceived level of thermal nociception from the stereotyped nociceptive response of individual nematodes _
caenorhabditis elegans _ stimulated by an ir laser .
the model provides a method for quantification of analgesic effects of chemical stimuli or genetic mutations in _ c. elegans_. we test the nociception of ibuprofen - treated worms and a trpv ( transient receptor potential ) mutant , and we show that the perception of thermal nociception for the ibuprofen treated worms is lower than the wild - type . at the same time
, our model shows that the mutant changes the worm s behavior beyond affecting nociception . finally , we determine the stimulus level that best distinguishes the analgesic effects and the minimum number of worms that allow for a statistically significant identification of these effects . .
And you have already written the first three sentences of the full article: pain is a common health problem that causes over $ 60 billion a year in productivity losses in the united states @xcite .
research on pain sensing ( also known as nociception ) with human subjects is difficult for a number of reasons including ethical constraints , difficulties in quantifying a psychophysical response , and subjectivity in self - reporting @xcite .
since the molecular mechanisms of pain transduction are believed to be partially conserved among many different species @xcite , some of these problems are solved by using animal models in nociception research ..
Please generate the next two sentences of the article
|
however , animal subjects can not communicate their perceived pain levels to us in an obvious fashion .
thus progress in using animal models depends crucially on our ability to quantitatively and objectively infer the perceived level of noxious stimuli from animal behavior .
|
10,774 |
Suppose that you have an abstract for a scientific paper: we have used coarse - grained simulation methods to investigate the effect of stretching - induced structure orientation on the proton conductivity of nafion - like polyelectrolyte membranes .
recent experimental data on the morphology of ionomers describe nafion as an aggregation of polymeric backbone chains forming elongated objects embedded in a continuous ionic medium .
uniaxial stretching of a recast nafion film causes a preferential orientation of these objects in the direction of stretching .
our simulations of humid nafion show that this has a strong effect on the proton conductivity , which is enhanced along the stretching direction , while the conductivity perpendicular to the stretched polymer backbone is reduced .
stretching also causes the perfluorinated side chains to orient perpendicular to the stretching axis .
this in turn affects the distribution of water at low water contents
. the water forms a continuous network with narrow bridges between small water clusters absorbed in head - group multiplets .
ionomers , proton diffusion , morphology .
And you have already written the first three sentences of the full article: in their role as proton - conducting membranes , ionomers are an important component of many hydrogen fuel cells . in these materials ,
the interplay among the short - range interactions between the hydrophobic backbone polymer and the hydrophilic terminal groups , and the long - range coulomb interactions between the electrostatic charges on the terminal groups and the protons induces a nanophase separation into proton - rich and proton - poor domains .
a general model for the phase morphology of ionomers has been proposed by eisenberg _.
Please generate the next two sentences of the article
|
et al . _
@xcite , according to which a few head groups combine to form multiplets that restrict the mobility of the backbone chain segments directly attached to them .
|
10,775 |
Suppose that you have an abstract for a scientific paper: in the randall - sundrum model , a bulk neutrino field in the 5-dimensional space - time can give rise to tiny dirac masses to neutrinos .
in such a scenario , we have computed the contribution of the bulk neutrino field to the anomalous magnetic moment @xmath0 of muon .
we have computed this contribution in the t hooft - feynman gauge and have found that the contribution has the right sign to fit the current discrepancy between the experiment and the standard model value of @xmath0 .
we have also studied possible constraints on the model parameters by including contributions to @xmath0 from other sources such as bulk gravitons . * muon @xmath1 from the bulk neutrino field in a warped extra dimensional model * + r. s. hundi , sourov roy and soumitra sengupta + department of theoretical physics , + indian association for the cultivation of science , + 2a @xmath2 2b raja s.c .
mullick road , + kolkata - 700 032 , india . .
And you have already written the first three sentences of the full article: the models in extra dimensions have been proposed for solving the hierarchy between the electroweak and planck scales @xcite . among these
the randall - sundrum ( rs ) model assumes the existence of two 3-branes connected by one extra spatial dimension and the metric in this model is non - factorizable @xcite .
the extra spatial coordinate has been orbifolded by the symmetry @xmath3 and one of the 3-branes can be identified as the visible brane and the other as the planck brane ..
Please generate the next two sentences of the article
|
the warp factor in this model suppresses any planck scale quantities into electroweak scale on the visible brane . in the rs model , all the standard model fields
are assumed to be confined on the visible brane and only gravity propagates in the bulk of the five dimensions .
|
10,776 |
Suppose that you have an abstract for a scientific paper: matrix product purifications ( mpp ) are a very efficient tool for the simulation of strongly correlated quantum many - body systems at finite temperatures .
when a system features symmetries , these can be used to reduce computation costs substantially .
it is straightforward to compute an mpp of a grand - canonical ensemble , also when symmetries are exploited .
this paper provides and demonstrates efficient methods to compute mpps of canonical ensembles under utilization of symmetries .
furthermore , we present a scheme for the evaluation of global quantum number distributions using matrix product density operators ( mpdo ) .
we give exact matrix product representations for canonical infinite - temperature states , and discuss how they can be constructed alternatively by applying matrix product operators to vacuum - type states or by using entangler hamiltonians .
a demonstration of the techniques for heisenberg spin-@xmath0 chains explains why the difference in the energy densities of canonical and grand - canonical ensembles decays as @xmath1 . .
And you have already written the first three sentences of the full article: strongly - correlated one - dimensional ( 1d ) and quasi-1d systems can be simulated accurately using the density matrix renormalization group ( dmrg ) @xcite , which is a set of algorithms operating on matrix product states ( mps ) @xcite .
real systems can usually not be isolated completely from their environment and experiments are hence necessarily done at finite ( nonzero ) temperatures . to allow for a direct investigation of experimental results or for theoretical investigations on the influence of temperature ,
dmrg techniques have been generalized to describe thermal states ..
Please generate the next two sentences of the article
|
the historically first dmrg algorithm for finite temperatures is the quantum transfer - matrix renormalization group @xcite , which is however complicated by the non - hermiticity of the quantum transfer matrix and does not allow for a direct evaluation of non - local observables .
a recent approach combines time - dependent dmrg @xcite with monte carlo to evaluate thermal observables by sampling over so - called minimally entangled typical thermal states @xcite and is also applicable for the study response functions @xcite .
|
10,777 |
Suppose that you have an abstract for a scientific paper: surface , image and video data can be considered as functional data with a bivariate domain . to detect outlying surfaces or images ,
a new method is proposed based on the mean and the variability of the degree of outlyingness at each grid point .
a rule is constructed to flag the outliers in the resulting functional outlier map .
heatmaps of their outlyingness indicate the regions which are most deviating from the regular surfaces . the method is applied to fluorescence excitation - emission spectra after fitting a parafac model , to mri image data which are augmented with their gradients , and to video surveillance data .
* keywords : * adjusted outlyingness , functional data , image data , multiway , robustness . .
And you have already written the first three sentences of the full article: the most common type of functional data are curves , typically measured over time .
also spectral data , measured over a range of wavelengths , can be considered as functional data and can be analyzed as such @xcite .
when several measurements are taken at each time point , we obtain multivariate functional data ..
Please generate the next two sentences of the article
|
bivariate examples are height and weight curves of children , temperature and dewpoint temperature at several weather stations during several days , or measurements of the human heart activity at two different places on the body @xcite .
whereas the domain of these data is always univariate , the response can thus be multivariate .
|
10,778 |
Suppose that you have an abstract for a scientific paper: in the framework of the local group census ( lgc ) , a survey of the local group ( lg ) galaxies above dec=@xmath0 , which is aimed at surveying their populations with strong emission lines , we have searched for planetary nebulae ( pne ) in the low - metallicity dwarf irregular galaxies ic 1613 , , 8 .
two new candidate pne have been found in ic 1613 , one in wlm and none in 8 .
the observations presented in this paper , together with the previous results from the lgc , represent the first step in the study of the pn population in low - metallicity , dwarf irregular galaxies of the local group .
they will be followed by deep spectroscopy to confirm their nature and to study their physical - chemical properties .
we used the observed number of pne in each lg galaxy to estimate a lower limit to the mass of the intermediate - age population which was compared to the star formation rate ( sfr ) of lg dwarf galaxies .
these results are in agreement with those from accurate star formation history ( sfh ) analysis for these small galaxy systems .
[ firstpage ] planetary nebulae : individual : ic 1613 , wlm galaxies : individual : ic 1613 , wlm , gr 8 .
And you have already written the first three sentences of the full article: the local group consists of three spiral galaxies and a large number of dwarf galaxies ( @xmath190% of its 40 known members ) .
this proportion of galaxy types may be typical of the local universe as similar distributions are known to exist in nearby groups @xcite and clusters @xcite .
the dwarf galaxies ( irregular , spheroidal or elliptical ) of the lg are of particular interest as their proximity allows us to study them in detail , testing predictions concerning their formation and evolution , as , for instance , the evolution of different kind of dwarfs @xcite or their star formation histories @xcite ..
Please generate the next two sentences of the article
|
furthermore , their study is relevant because , according to the hierarchical scenario of galaxy formation , dwarf galaxies are the first structures to form and from their merging larger galaxies are built @xcite .
moreover , low - luminosity dwarf galaxies , as those discussed in this paper , are metal poor and are expected to have abundances close to primordial values @xcite . thus the abundances derived there can be useful in extrapolating primordial he / h ( @xcite ; @xcite ) .
|
10,779 |
Suppose that you have an abstract for a scientific paper: astrosat is an astronomy satellite designed for simultaneous multi - wavelength studies in the optical / uv and a broad x - ray energy range . with four x - ray instruments and a pair of uv - optical telescopes
, astrosat will provide unprecendented opportunity for simultaneous multi - wavelength observations , which is of immense value in study of highly variable sources , especially x - ray binaries and active galactic nuclei .
the large area x - ray proportional counters ( laxpc ) of astrosat , which has the largest effective area in the hard x - ray band compared to all previous x - ray missions , will enable high time resolution x - ray measurements in the 2 - 80 kev band with moderate energy resolution . here
we give a brief summary of the payload characteristics of astrosat and discuss some of the main science topics that will be addressed with the laxpc , and with simultaneous observations with the uvit telescopes , with particular emphasis on x - ray binaries and compact objects .
the possibility of aiding gravitational wave experiments is also briefly mentioned . .
And you have already written the first three sentences of the full article: almost all astrophysical objects have significant non - thermal processes that result in emission across a broad energy band .
even stars exhibit flares which are non - thermal processes .
multi - wavelength observations are therefore key to have complete understanding of a variety of astrophysical objects and astrophysical processes ..
Please generate the next two sentences of the article
|
x - ray binaries and active galactic nuclei ( agn ) are prime examples of objects with emission over a wide band .
often the most dominant part of the electromagnetic emission is within the optical to hard x - ray band .
|
10,780 |
Suppose that you have an abstract for a scientific paper: we investigate the neutron pair transfer modes associated with the low - lying quadrupole states in neutron - rich sn isotopes by means of the quasiparticle random phase approximation based on the skyrme - hartree - fock - bogoliubov mean field model .
the transition strength of the quadrupole pair - addition mode feeding the @xmath0 state is enhanced in the sn isotopes with @xmath1 .
the transition density of the pair - addition mode has a large spatial extension in the exterior of nucleus , reaching far to @xmath2 fm .
the quadrupole pair - addition mode reflects sensitively a possible increase of the effective pairing interaction strength in the surface and exterior regions of neutron - rich nuclei . .
And you have already written the first three sentences of the full article: the pair correlation is one of the fundamental nucleon many - body correlations , which governs many aspects of the nuclear structure@xcite .
recently attentions are paid to the properties of the pair correlation in neutron - rich nuclei , which exhibit new features such as the neutron halo , the neutron skin and the presence of weakly bound neutrons .
for example , a spatial two - neutron correlation or the di - neutron correlation , between two weakly - bound neutrons forming the halo in @xmath3li and @xmath4he has been discussed extensively @xcite , and its experimental signatures are reported recently @xcite ..
Please generate the next two sentences of the article
|
there exists also several theoretical studies demonstrating similar spatial two - neutron correlation in many other nuclear systems .
the spatial two - particle correlation was originally discussed in the closed - shell + two - particle systems @xcite , and recent selfconsistent hartree - fock - bogoliubov mean - field calculations suggest that the correlation is generically enhanced around the nuclear surface of neutron - rich nuclei covering also medium- and heavy - mass regions @xcite . furthermore it is found that neutron matter at low densities may exhibit features of the strong coupling pairing@xcite , characterized by the small size ( @xmath5 fm at minimum ) of the cooper pair comparable with the average inter - neutron distance @xcite , reflecting the large scattering length @xmath6fm of the bare nuclear force .
|
10,781 |
Suppose that you have an abstract for a scientific paper: extensive measurements of the microwave conductivity of highly pure and oxygen - ordered yba@xmath0cu@xmath1o@xmath2 single crystals have been performed as a means of exploring the intrinsic charge dynamics of a @xmath3-wave superconductor .
broadband and fixed - frequency microwave apparatus together provide a very clear picture of the electrodynamics of the superconducting condensate and its thermally excited nodal quasiparticles .
the measurements reveal the existence of very long - lived excitations deep in the superconducting state , as evidenced by sharp cusp - like conductivity spectra with widths that fall well within our experimental bandwidth .
we present a phenomenological model of the microwave conductivity that captures the physics of energy - dependent quasiparticle dynamics in a @xmath3-wave superconductor which , in turn , allows us to examine the scattering rate and oscillator strength of the thermally excited quasiparticles as functions of temperature .
our results are in close agreement with the ferrell - glover - tinkham sum rule , giving confidence in both our experiments and the phenomenological model .
separate experiments for currents along the @xmath4 and @xmath5 directions of detwinned crystals allow us to isolate the role of the cuo chain layers in yba@xmath0cu@xmath1o@xmath2 , and a model is presented that incorporates both one - dimensional conduction from the chain electrons and two - dimensional transport associated with the cuo@xmath0 plane layers . .
And you have already written the first three sentences of the full article: microwave conductivity measurements have provided a powerful method for investigating the low energy charge dynamics of high temperature cuprate superconductors .
early on , the observation of a linear temperature dependence of the magnetic penetration depth @xmath6 in yba@xmath0cu@xmath1o@xmath7 provided some of the first evidence of @xmath3-wave pairing in these materials.@xcite over a decade later , the @xmath3-wave superconducting phase remains one of the cornerstones of our understanding of the cuprate problem .
surprisingly , the physics of the superconducting state seems to be well described as a bcs instability of a two - dimensional fermi liquid . however , it is essential that this conjecture be thoroughly tested , and one of the best ways to do this is through detailed measurements of charge transport in high quality single crystals . in this work.
Please generate the next two sentences of the article
|
we report on microwave spectroscopy of two gold - standard cuprate materials ortho - i yba@xmath0cu@xmath1o@xmath8 and ortho - ii yba@xmath0cu@xmath1o@xmath9 and develop a simple phenomenology that describes their low - energy charge dynamics . understanding the role of impurities in the cuprate superconductors
has taken many years of great effort .
|
10,782 |
Suppose that you have an abstract for a scientific paper: the lower excitation spectrum of the nucleon and @xmath0 is calculated in a relativistic chiral quark model .
corrections to the baryon mass spectrum from the second order self - energy and exchange diagrams induced by pion and gluon fields are estimated in the field -theoretical framework .
convergent results for the self - energy terms are obtained when including the intermediate quark and antiquark states with a total momentum up to @xmath1 .
relativistic one - meson and color - magnetic one - gluon exchange forces are shown to generate spin 0 , 1 , 2 , etc .
operators , which couple the lower and the upper components of the two interacting valence quarks and yield reasonable matrix elements for the lower excitation spectrum of the nucleon and delta .
the only contribution to the ground state nucleon and @xmath0 comes from the spin 1 operators , which correspond to the exchanged pion or gluon in the l=1 orbit , thus indicating , that the both pion exchange and color - magnetic gluon exchange forces can contribute to the spin of baryons .
is is shown also that the contribution of the color - electric component of the gluon fields to the baryon spectrum is enormously large ( more than 500 mev with a value @xmath2 ) and one needs to restrict to very small values of the strong coupling constant or to exclude completely the gluon - loop corrections to the baryon spectrum . with this restriction
, the calculated spectrum reproduces the main properties of the data , however needs further contribution from the two - pion exchange and instanton induced exchange ( for the nucleon sector ) forces in consistence with the realistic nn - interaction models . .
And you have already written the first three sentences of the full article: the spectroscopy is a serious task for any model of hadron structure .
it can yield a detailed information on the source of hyperfine interaction , as well as on effective degrees of freedom in the description of hadron dynamics .
the so - called `` three - body spin - orbit puzzle '' has a long history . in the original papers of isgur and karl @xcite.
Please generate the next two sentences of the article
|
it was shown that the whole su(3 ) baryon spectrum can be reproduced qualitatively and ( with some restrictions ) quantitatively in a constituent quark model based on a non - relativistic hamiltonian with a central confining potential plus effective color - magnetic one - gluon exchange ( oge ) forces .
the hyperfine interaction was assumed to be a sum of the spin - spin , tensor and spin - orbit interaction potentials between the constituent quarks . however , the spin - orbit term yields a very large ( of order 500 mev ) matrix elements in the three - body system ( typical baryons ) , while in mesons and meson - like baryons @xcite the matrix elements are small as a result of the strong cancelation between the dynamical one - gluon exchange spin - orbit forces and a pure kinematical spin - orbit forces due - to the thomas precession of the quark spin in the central confining potential .
|
10,783 |
Suppose that you have an abstract for a scientific paper: an abelian differential gives rise to a flat structure ( translation surface ) on the underlying riemann surface . in some directions
the directional flow on the flat surface may contain a periodic region that is made up of maximal cylinders filled by parallel geodesics of the same length .
the growth rate of the number of such regions counted with weights , as a function of the length , is quadratic with a coefficient , called siegel veech constant , that is shared by almost all translation surfaces in the ambient stratum .
we evaluate various siegel
veech constants associated to the geometry of configurations of periodic cylinders and their area , and study extremal properties of such configurations in a fixed stratum and in all strata of a fixed genus . .
And you have already written the first three sentences of the full article: suppose that @xmath0 is a closed connected oriented surface @xmath1 of genus @xmath2 with a set of @xmath3 labelled marked points @xmath4 . by a _ translation surface _
@xmath5 we mean a flat riemannian metric and a parallel vector field on @xmath0 .
the metric has cone type singularities at all of the points @xmath6 of @xmath7 where the total angle is of the form @xmath8 for some integer @xmath9 ..
Please generate the next two sentences of the article
|
each geodesic on a translation surface moves in a constant direction , so geodesics do not have self intersections and a regular geodesic that connects a non - singular point to itself comes back with the same angle , so it is a periodic geodesic .
a periodic geodesic is always part of a maximal connected periodic region : a maximal cylinder of parallel periodic geodesics of the same length .
|
10,784 |
Suppose that you have an abstract for a scientific paper: * background : * previous measurements of @xmath0-delayed neutron emitters comprise around 230 nuclei , spanning from the @xmath1he up to @xmath2la . apart from @xmath3tl , with a minuscule branching ratio of 0.007% , no other neutron emitter is measured yet beyond @xmath4 . therefore new data are needed , particularly in the heavy mass region around n=126 , in order to guide theoretical models and to understand the formation of the third r - process peak at @xmath5 . + * purpose : * to measure both , @xmath0-decay half - lives and neutron branching ratios of several neutron - rich au , hg , tl , pb and bi isotopes beyond @xmath6 . + * method : * ions of interest are produced by fragmentation of a @xmath7u beam , selected and identified via the gsi - frs fragment separator . a stack of segmented silicon detectors ( simba ) is used to measure ion - implants and @xmath0-decays .
an array of 30 @xmath8he tubes embedded in a polyethylene matrix ( belen ) is used to detect neutrons with high efficiency and selectivity .
a self - triggered digital system is employed to acquire data and to enable time - correlations .
the latter are analyzed with an analytical model and results for the half - lives and neutron - branching ratios are derived using the binned maximum - likelihood method .
+ * results : * twenty new @xmath0-decay half - lives are reported for @xmath9au , @xmath10hg,@xmath11tl,@xmath12pb and @xmath13bi , nine of them for the first time .
neutron emission probabilities are reported for @xmath14hg and @xmath11tl . + * conclusions : * the new @xmath0-decay half - lives are in good agreement with previous measurements in this region .
the measured neutron emission probabilities are comparable or smaller than values predicted by global models like rhb+rqrpa . .
And you have already written the first three sentences of the full article: very neutron - rich nuclei may emit one or more neutrons when they disintegrate via @xmath0 decay .
this is the so - called @xmath0-delayed neutron ( @xmath15 ) emission process , which is energetically allowed when the q@xmath16-value of the decay exceeds the neutron separation energy ( s@xmath17 ) of the daughter nucleus .
the @xmath15-emission has been experimentally determined for about 230 neutron rich nuclei , spanning from @xmath1he up to @xmath2la @xcite ..
Please generate the next two sentences of the article
|
most of these measurements took advantage of the large fission yields around the two fission peaks at @xmath18 and @xmath19 .
however , @xmath0-delayed neutron emission has remained essentially inaccessible for nuclei heavier than @xmath4 , where only a minuscule value of 0.007% has been reported for the @xmath15-emission probability of @xmath3tl @xcite . because of the scarce or non - existent @xmath15 data in the heavy mass region , rapid neutron capture @xmath20-process @xcite calculations have to rely entirely on theoretical models @xcite .
|
10,785 |
Suppose that you have an abstract for a scientific paper: we propose efficient parallel algorithms and implementations on shared memory architectures of lu factorization over a finite field . compared to the corresponding numerical routines , we have identified three main difficulties specific to linear algebra over finite fields .
first , the arithmetic complexity could be dominated by modular reductions .
therefore , it is mandatory to delay as much as possible these reductions while mixing fine - grain parallelizations of tiled iterative and recursive algorithms .
second , fast linear algebra variants , e.g. , using strassen - winograd algorithm , never suffer from instability and can thus be widely used in cascade with the classical algorithms . there , trade - offs are to be made between size of blocks well suited to those fast variants or to load and communication balancing .
third , many applications over finite fields require the rank profile of the matrix ( quite often rank deficient ) rather than the solution to a linear system .
it is thus important to design parallel algorithms that preserve and compute this rank profile . moreover , as the rank profile is only discovered during the algorithm , block size has then to be dynamic .
we propose and compare several block decomposition : tile iterative with left - looking , right - looking and crout variants , slab and tile recursive .
experiments demonstrate that the tile recursive variant performs better and matches the performance of reference numerical software when no rank deficiency occur .
furthermore , even in the most heterogeneous case , namely when all pivot blocks are rank deficient , we show that it is possbile to maintain a high efficiency . .
And you have already written the first three sentences of the full article: triangular matrix factorization is a main building block in computational linear algebra . driven by a large range of applications in computational sciences ,
parallel numerical dense lu factorization has been intensively studied since several decades which results in software of great maturity ( e.g. , linpack is used for benchmarking the efficiency of the top 500 supercomputers @xcite ) .
more recently , efficient sequential exact linear algebra routines were developed @xcite ..
Please generate the next two sentences of the article
|
they are used in algebraic cryptanalysis , computational number theory , or integer linear programming and they benefit from the experience in numerical linear algebra . in particular , a key point there is to embed the finite field elements in integers stored as floating point numbers , and then rely on the efficiency of the floating point matrix multiplication ` dgemm ` of the blas .
the conversion back to the finite field , done by costly modular reductions , is delayed as much as possible .
|
10,786 |
Suppose that you have an abstract for a scientific paper: we extend a lattice boltzmann algorithm of liquid crystal hydrodynamics to include an applied electric field .
the approach solves the equations of motion written in terms of a tensor order parameter .
back - flow effects and the hydrodynamics of topological defects are included .
we investigate some of the dynamics relevant to liquid crystal devices ; in particular defect - mediated motion of domain walls relevant to the nucleation of states useful in pi - cells .
an anisotropy in the domain wall velocity is seen because defects of different topology couple differently to the flow field .
+ * key words : * lattice boltzmann ; liquid crystals ; complex fluids . .
And you have already written the first three sentences of the full article: the coupling of the optic and electric response of liquid crystals has lead to their wide application in display devices in recent years .
liquid crystalline materials are often made up of long , thin , rod - like molecules@xcite .
this anisotropy is what leads to their useful optic properties ..
Please generate the next two sentences of the article
|
the molecular geometry and interactions can lead to a wide range of equilibrium phases . in this paper
we are concerned with the nematic phase where the molecules tend to align along a preferred direction , referred to as the director , giving long - range orientational order .
|
10,787 |
Suppose that you have an abstract for a scientific paper: the first arcsecond localization of a short gamma - ray burst , grb @xmath0b , has enabled detailed studies of a short burst environment .
we here report on studies of the environment of grb @xmath0b using the _ swift _ x - ray telescope ( xrt ) .
the xrt error circle of the burst overlaps with an elliptical galaxy in the cluster of galaxies zwcl 1234.0 + 02916 .
based on the measured x - ray flux of the cluster we estimate that the probability for a chance superposition of grb @xmath0b and a cluster at least as x - ray bright as this cluster is @xmath1 , presenting the first strong case of a short burst located in a cluster of galaxies .
we also consider the case for grb @xmath0b being located behind zwcl 1234.0 + 02916 and gravitationally lensed . from the velocity dispersion of the elliptical galaxy and the temperature of hot intracluster gas , we model the mass distribution in the elliptical galaxy and the cluster , and calculate the gravitational lensing magnification within the xrt error circle .
we find that , if grb050509b would be positioned significantly behind the cluster , it is most likely magnified by a factor less than two , but that the burst could be strongly lensed if it is positioned within @xmath2 of the center of the bright elliptical galaxy .
further mapping of arcsecond size short burst error boxes is a new promising route to determine the spatial distribution of old stars throughout the universe . .
And you have already written the first three sentences of the full article: about 25% of all gamma - ray bursts detected by batse were `` short '' ( duration less than 2 s , * ? ? ? * ) and had hard spectra . due to the non - detection of an afterglow from a short burst , rendering quick and accurate localization unfeasible ,
their nature have remained elusive .
grb @xmath0b was detected by the _.
Please generate the next two sentences of the article
|
swift _ burst alert telescope ( bat ) on 2005 may 9 at 04:00:19.23 ( ut ) @xcite and upon slewing the _ swift _ x - ray telescope ( xrt ) started observations of the burst 62 s after the bat was triggered .
for the first time , an x - ray afterglow from a short burst was detected enabling a localization within @xmath3 @xcite .
|
10,788 |
Suppose that you have an abstract for a scientific paper: we introduce a new concept of resonance on discrete dynamical systems .
this concept formalizes the observation that , in various combinatorially - natural cyclic group actions , orbit cardinalities are all multiples of divisors of a fundamental frequency .
our prototypical example of this phenomenon is b. wieland s gyration action on alternating sign matrices .
our main result is an equivariant bijection between plane partitions in a box ( or order ideals in the product of three chains ) under rowmotion and increasing tableaux under @xmath0-promotion .
both of these actions were observed to have orbit sizes that were small multiples of divisors of an expected orbit size , and we show this is an instance of resonance , as @xmath0-promotion cyclically rotates the set of labels appearing in the increasing tableaux .
we extract a number of corollaries from this equivariant bijection , including a strengthening of a theorem of [ p. cameron d .
fon - der - flaass 95 ] and several new results on the order of @xmath0-promotion . along the way
, we adapt the proof of the conjugacy of promotion and rowmotion from [ j. striker
n .
williams 12 ] to give a generalization in the setting of @xmath1-dimensional lattice projections . .
And you have already written the first three sentences of the full article: the introduction to this paper is in two parts .
the first subsection defines resonance and gives our prototypical example on alternating sign matrices .
the second subsection describes our main results ; these include two instances of resonance ( on plane partitions and increasing tableaux ) , an equivariant bijection between these two sets with a number of new consequences , and a higher - dimensional analogue of n. williams and the third author s result on the equivariance of ( poset-)promotion and rowmotion @xcite ..
Please generate the next two sentences of the article
|
we introduce the following concept of _ _
resonance__. suppose @xmath2 is a cyclic group acting on a set @xmath3 , @xmath4 a cyclic group of order @xmath5 acting nontrivially on a set @xmath6 , and @xmath7 a surjection .
|
10,789 |
Suppose that you have an abstract for a scientific paper: in this paper we revisit uniformly hyperbolic basic sets and the domination of oseledets splittings at periodic points . we prove that periodic points with simple lyapunov spectrum are dense in non - trivial basic pieces of @xmath0-residual diffeomorphisms on three - dimensional manifolds ( @xmath1 ) . in the case of the @xmath2-topology
we can prove that either all periodic points of a hyperbolic basic piece for a diffeomorphism @xmath3 have simple spectrum @xmath2-robustly ( in which case @xmath3 has a finest dominated splitting into one - dimensional sub - bundles and all lyapunov exponent functions of @xmath3 are continuous in the weak@xmath4-topology ) or it can be @xmath2-approximated by an equidimensional cycle associated to periodic points with robust different signatures . the later can be used as a mechanism to guarantee the coexistence of infinitely many periodic points with different signatures . .
And you have already written the first three sentences of the full article: a global view of dynamical systems has been one of the leading problems considered by the dynamical systems community . based on the pioneering works of peixoto and smale ,
a conjecture proposed by palis in the nineties has constituted a route guide for a global description of the space of dynamical systems .
this program , that roughly describes complement of uniform hyperbolicity as the space of diffeomorphisms that are approximated by those exhibiting either homoclinic tangencies or heteroclinic cycles , has been completed with much success in the @xmath2-topology , where perturbation tools like the pugh closing lemma , franks lemma , hayashi s connecting lemma or ma ergodic closing lemma developed for the characterization of structural stability are available ( see e.g. @xcite and references therein ) ..
Please generate the next two sentences of the article
|
although the uniform geometric structures of invariant manifolds present in hyperbolic diffeomorphisms are a basic ingredient in achieving several core results and are quite well established , some important questions on the regularity of finer dynamical properties still remain to be answer .
motivated by the analysis of the regularity of the lyapunov exponents similarly to the proof of the stability conjecture , periodic orbits and their eigenvalues should play a key role .
|
10,790 |
Suppose that you have an abstract for a scientific paper: we evaluate separation dependent van der waal dispersion ( @xmath0 ) coefficients for the interactions of the li , na , k and rb alkali atoms with a graphene layer and with a single walled carbon nanotube ( cnt ) using the hydrodynamic and dirac models .
the results from both the models are evaluated using accurate values of the dynamic polarizabilities of the above atoms .
accountability of these accurate values of dynamical polarizabilities of the alkali atoms in determination of the above @xmath0 coefficients are accentuated by comparing them with the coefficients evaluated using the dynamic dipole polarizabilities estimated from the single oscillator approximation which are typically employed in the earlier calculations .
for practical description of the atom - surface interaction potentials the radial dependent @xmath0 coefficients are given for a wide range of separation distances between the ground states of the considered atoms and the wall surfaces and also for different values of nanotube radii .
the coefficients for the graphene layer are fit to a logistic function dependent on the separation distance . for cnt ,
we have carried out a paraboloid kind of fit dependent on both the separation distances and radii of the cnt .
these fitted functions , with the list of fitting parameters , can be used to extrapolate the interaction potentials between the considered alkali atoms and the graphene layer or cnt surface conveniently at the given level of accuracy . .
And you have already written the first three sentences of the full article: in the past decade considerable amount of attention have been drawn both towards the experimental and theoretical studies of the internal scattering of atoms with a graphene layer and with various carbon nanostructures @xcite .
owing to the fact that these nanostructures are endowed with exceptional electronic , optical , mechanical , thermal , and magnetic properties that are of vested interest to the modern communication engineering technologies @xcite , their applications are in huge demand both in the scientific and industrial laboratories .
graphene , in particular , manifest unique properties incurring its honey comb - lattice structure that could maximize the interaction of atom on the layer ..
Please generate the next two sentences of the article
|
in fact , the knowledge of the atom - graphene interactions has been very useful in the construction of the hydrogen storage devices @xcite and also plays an important role in understanding different physical , chemical and biological processes @xcite .
moreover , these interactions are connected to the phenomenon of quantum reflections whose studies are of special interest today to many experimentalists and theoreticians for explaining their exact behavior @xcite .
|
10,791 |
Suppose that you have an abstract for a scientific paper: the distribution of interstellar dust grains ( isdg ) observed in the solar system depends on the nature of the interstellar medium - solar wind interaction .
the charge of the grains couples them to the interstellar magnetic field ( ismf ) resulting in some fraction of grains being excluded from the heliosphere while grains on the larger end of the size distribution , with gyroradii comparable to the size of the heliosphere , penetrate the termination shock .
this results in a skewing the size distribution detected in the solar system .
we present new calculations of grain trajectories and the resultant grain density distribution for small isdgs propagating through the heliosphere .
we make use of detailed heliosphere model results , using three - dimensional ( 3-d ) magnetohydrodynamic / kinetic models designed to match data on the shape of the termination shock and the relative deflection of interstellar and flowing into the heliosphere .
we find that the necessary inclination of the ismf relative to the inflow direction results in an asymmetry in the distribution of the larger grains ( 0.1 ) that penetrate the heliopause .
smaller grains ( 0.01 ) are completely excluded from the solar system at the heliopause .
address = harvard - smithsonian center for astrophysics , 60 garden st .
, cambridge , ma 02138 ( usa ) address = dept .
astronomy & astrophysics , u. chicago , 5640 s. ellis ave . ,
chicago , il 60637 ( usa ) address = u .
alabama - huntsville , center for space plasma and aeronomic research , huntsville , al 35899 address = u .
alabama - huntsville , center for space plasma and aeronomic research , huntsville , al 35899 address = dept . of physics and astronomy , 6127 wilder lab , dartmouth college , hanover , nh 03755 address = infrared processing and analysis center , caltech , pasadena , ca
91125 address = u .
alabama - huntsville , center for space plasma and aeronomic research , huntsville , al 35899 address = u .
alabama -....
And you have already written the first three sentences of the full article: up to one percent of the mass of the interstellar cloud surrounding the heliosphere is carried by dust grains that interact with the heliosphere @xcite . the flow of interstellar material past the sun at 26.4 drives large interstellar dust grains into the heliosphere , while small grains are diverted around the heliosphere by the interstellar magnetic field ( ismf ) .
the heliospheric trajectories of intermediate sized grains can be complicated and depend on the solar wind magnetic field and thus solar cycle phase .
observations of isdgs in the solar system by the ulysses , galileo and cassini spacecraft show that the density of smallest grains are deficient in the inner heliosphere when compared to the nominal mathis et al ..
Please generate the next two sentences of the article
|
`` mrn '' power law size distribution ( e.g. * ? ? ?
* ; * ? ? ?
|
10,792 |
Suppose that you have an abstract for a scientific paper: empirical tight binding(etb ) methods are widely used in atomistic device simulations .
traditional ways of generating the etb parameters rely on direct fitting to bulk experiments or theoretical electronic bands .
however , etb calculations based on existing parameters lead to unphysical results in ultra small structures like the as terminated gaas ultra thin bodies(utbs ) . in this work
, it is shown that more reliable parameterizations can be obtained by a process of mapping _
ab - initio _ bands and wave functions to tight binding models .
this process enables the calibration of not only the etb energy bands but also the etb wave functions with corresponding _ ab - initio _ calculations .
based on the mapping process , etb model of si and gaas are parameterized with respect to hybrid functional calculations .
highly localized etb basis functions are obtained .
both the etb energy bands and wave functions with subatomic resolution of utbs show good agreement with the corresponding hybrid functional calculations .
the etb methods can then be used to explain realistically extended devices in non - equilibrium that can not be tackled with _
ab - initio _ methods . .
And you have already written the first three sentences of the full article: modern semiconductor nanodevices have reached critical device dimensions in the sub-10 nanometer range .
these devices consist of complicated two or three dimensional geometries and are composed of multiple materials .
confined geometries such as ultra thin body ( utb)@xcite , finfets@xcite and nanowires@xcite structures are usually adopted in nanometer scale device designs to obtain desired performance characteristics.most of the electrically conducting devices are not arranged in infinite periodic arrays , but are of finite extent with contacts controlling the current injections and potential modulation . typically , there are about 10000 to 10 million atoms in the active device region with contacts controlling the current injection ..
Please generate the next two sentences of the article
|
these finite sized structures suggest an atomistic , local and orbital - based electronic structure representation for device level simulation .
quantitative device design requires the reliable prediction of the materials band gaps and band offsets within a few mev and important effective masses within a few percent in the geometrically confined active device regions .
|
10,793 |
Suppose that you have an abstract for a scientific paper: we consider reflector imaging in a weakly random waveguide .
we address the situation in which the source is farther from the reflector to be imaged than the energy equipartition distance , but the receiver array is closer to the reflector to be imaged than the energy equipartition distance . as a consequence ,
the reflector is illuminated by a partially coherent field and the signals recorded by the receiver array are noisy .
this paper shows that migration of the recorded signals can not give a good image , but an appropriate migration of the cross correlations of the recorded signals can give a very good image .
the resolution and stability analysis of this original functional shows that the reflector can be localized with an accuracy of the order of the wavelength even when the receiver array has small aperture , and that broadband sources are necessary to ensure statistical stability , whatever the aperture of the array . .
And you have already written the first three sentences of the full article: sensor array imaging in a scattering medium is limited because coherent signals recorded at the source - receiver array and coming from a reflector to be imaged are dominated by incoherent signals coming from multiple scattering by the medium . for instance , in a randomly perturbed waveguide , it is known that the field becomes completely incoherent when the propagation distance becomes larger than the equipartition distance , which corresponds to the distance beyond which the source energy has been shared equally among all the propagating modes ( * ? ? ?
* chapter 20 ) .
as we will see , if the distance between the source - receiver array and the reflector is larger than the equipartition distance , then classical migration of the signals recorded at the array can not give a good image ..
Please generate the next two sentences of the article
|
sources can be expensive or difficult to implement but receivers can be cheap and easy to implement , so an imaging problem in which there are a few sources ( all of them being far from the reflector ) and many receivers ( some of them being close to the reflector ) is of theoretical and practical interest . if there is a unique source far from the reflector ( farther than the equipartition distance ) and if the receiver array is close to the reflector ( closer than the equipartition distance ) , then classical migration of the recorded signals fails again .
this was shown is various contexts and we will show it again in the waveguide geometry .
|
10,794 |
Suppose that you have an abstract for a scientific paper: let @xmath0 be a non - compact , real semisimple lie group .
we consider maximal complexifications of @xmath0 which are adapted to a distinguished one - parameter family of naturally reductive , left - invariant metrics . in the case of @xmath1
their realization as equivariant riemann domains over @xmath2 is carried out and their complex - geometric properties are investigated .
one obtains new examples of non - univalent , non - stein , maximal adapted complexifications . .
And you have already written the first three sentences of the full article: let @xmath3 be a linear connection on a real - analytic manifold @xmath4 which is identified with the zero section in the tangent bundle @xmath5 . a complex structure defined on a domain @xmath6 of @xmath7 containing @xmath8
is adapted to the connection if for any @xmath9-geodesic @xmath10 its complexification @xmath11 , given by @xmath12 , is holomorphic on @xmath13 .
in this situation we refer to @xmath6 as an adapted complexification of @xmath14 . in the case where @xmath3 is real - analytic , r. bielawski ( @xcite ) and.
Please generate the next two sentences of the article
|
r. szke ( @xcite ) recently showed that the adapted complex structure exists in a neighborhood of @xmath15 . in @xcite
one also finds a uniqueness result . for the levi civita connection of a real - analytic riemannian manifolds , such results were known since the pioneering works of guillemin - stenzel ( @xcite ) and lempert - szke ( @xcite ) . in the presence of a large enough " lie group acting on @xmath8 and preserving the geodesic flow induced by @xmath9 , one can prove that there exists a maximal domain @xmath6 for the adapted complex structure , i.e.@xmath16every adapted complexification is necessarily contained in @xmath6 ( see@[email protected] , cf .
|
10,795 |
Suppose that you have an abstract for a scientific paper: in 2001 , stlund conjectured that reidemeister moves 1 and 3 are sufficient to describe a homotopy from any generic immersion @xmath0 to the standard embedding of the circle .
we show that this conjecture is false . .
And you have already written the first three sentences of the full article: we wish to consider the problem of simplifying immersed planar curves , in a sense which will later be made precise .
intuitively , a generic immersion @xmath1 can be considered as a knot diagram without the crossing data , and for such immersions we can apply planar versions of the reidemeister moves for knot diagrams . by applying all three reidemeister moves to such a diagram ,
one is able to obtain a standardly embedded circle with no double points ..
Please generate the next two sentences of the article
|
one way to see this is to add crossing data so as to give a knot diagram of the unknot ; applying the standard three reidemeister moves to this knot diagram gives the standardly embedded circle @xcite . in @xcite , stlund observed that reidemeister 1 is the only move that changes the degree of the gauss map , and showed that reidemeister move 3 is the only move that can change the signed number of instances of certain subdiagrams of the gauss diagram for an embedding .
these properties were used to show that any knot @xmath2 admits a pair of diagrams such that every sequence of reidemeister moves connecting them contains instances of reidemeister moves 1 and 3 .
|
10,796 |
Suppose that you have an abstract for a scientific paper: in this paper we explore collisional ionization and time - evolving photoionization in the , x - ray discovered , ionized absorbers in seyfert galaxies .
these absorbers show temporal changes inconsistent with simple equilibrium models .
we develop a simple code to follow the temporal evolution of non - equilibrium photoionized gas . as a result
several effects appear that are easily observable ; and which , in fact , may explain otherwise paradoxical behavior .
specifically we find that : 1 . in many important astrophysical conditions ( ovii , oviii dominant ; and high ( @xmath0@xmath1 ) column density ) pure collisional and photoionization equilibria
can be distinguished with moderate spectral resolution observations , due to a strong absorption structure between 1 and 3 kev .
this feature is due mainly to iron l xvii - xix and neon k ix - x absorption , which is much stronger in collisional models .
this absorption structure may be mis - interpreted as a flattening of the intrinsic emission spectrum above @xmath2 kev in low resolution data .
2 . in time - evolving non - equilibrium photoionization models
the response of the ionization state of the gas to sudden changes of the ionizing continuum is smoothed and delayed at low gas densities ( usually up to @xmath3 @xmath4 ) , even when the luminosity increases .
the recombination time can be much longer ( up to orders of magnitude ) than the photoionization timescale .
hence a photoionized absorber subject to frequent , quick , and consistent changes of ionizing luminosity is likely to be overionized with respect to the equilibrium ionization state .
3 .
if the changes of the ionizing luminosity are not instantaneous , and the electron density is low enough ( the limit depends on the average ionization state of the gas , but is usually @xmath5 @xmath4 to @xmath6 @xmath4 ) , the ionization state of the gas can continue to increase while the source luminosity decreases , so a maximum in the ionization state of a given....
And you have already written the first three sentences of the full article: the detection and the study of ionized absorbers is more difficult than that of cold neutral absorbers , but can yield much more detailed information about the nature of the absorbers and the state and geometry of the nuclear regions of agn .
if photoionization applies then the electron density of the gas and its distance from the ionizing source can be estimated .
absorption features from ionized gas , are common in the x - ray spectra of seyfert galaxies and some quasars.178 , halpern ( 1984 ) , pan , stewart and pounds ( 1990 ) ; 3c 351 , fiore et al ..
Please generate the next two sentences of the article
|
( 1993 ) , nicastro et al . , 1998 ;
see also reynolds ( 1997 ) ] deep oxygen vii and viii absorption edges at 0.74 kev and 0.87 kev ( rest ) have been detected by the rosat pspc and the asca sis in quite a large number of seyfert 1 galaxies ( reynolds , 1997 ) .
|
10,797 |
Suppose that you have an abstract for a scientific paper: the high - spin states in odd - odd @xmath0tl nucleus have been studied by populating them using the @xmath1re(@xmath2c , xn ) reactions at 75 mev of beam energy .
a @xmath3 coincidence measurement has been performed using the inga array with a digital data acquisition system to record the time stamped data .
definite spin - parity assignment of the levels was made from the dco ratio and the ipdco ratio measurements .
the level scheme of @xmath0tl has been extended up to 4.1 mev in excitation energy including 19 new @xmath4-ray transitions .
the @xmath5 band , in the neighboring odd - odd tl isotopes show very similar properties in both experimental observables and calculated shapes .
two new band structures , with 6-quasiparticle configuration , have been observed for the first time in @xmath0tl .
one of these bands has the characteristics of a magnetic rotational band . cranked shell model calculations , using a deformed woods - saxon potential ,
have been performed to obtain the total routhian surfaces in order to study the shapes of the bands and the band crossing in @xmath0tl .
the semiclassical formalism has been used to describe the magnetic rotational band . .
And you have already written the first three sentences of the full article: the thallium nuclei , with proton number z = 81 , are situated in a transition region between the deformed prolate rare earth nuclei and the spherical lead nuclei at z = 82 .
the proton fermi level in tl lies below the z = 82 shell closure and near the 2s@xmath6 orbtal .
the ground state spin - parity of the heavier odd - a thalium isotopes , are accordingly , 1/2@xmath7 @xcite ..
Please generate the next two sentences of the article
|
however , the intruder 9/2@xmath8[505 ] and 1/2@xmath8[541 ] nilsson states , originating from the @xmath9h@xmath10 orbital above z = 82 , are also available near the fermi surface for oblate and prolate deformations , respectively .
the experimental evidence comes from the observation of a low lying 9/2@xmath8 isomeric state and strongly coupled rotational bands built on this in the odd - a thalium isotopes @xcite .
|
10,798 |
Suppose that you have an abstract for a scientific paper: recently it has been understood that flavor - changing processes mediated by higgs bosons could be a new and powerful tool for discovering supersymmetry . in this paper
we show that they may also provide an important method for constraining the parameters of the minimal supersymmetric standard model ( mssm ) .
specifically , we show that observation of @xmath0 at the tevatron implies a significant , model - independent lower bound on @xmath1 in the mssm .
this is very important because @xmath1 enters crucially in predictions and interpretations of the mssm , though it is difficult to measure . within specific models , or with other data ,
the bound becomes significantly stronger .
@=11 caption#1[#2]#3 @=12 .7ex .7ex gev mev ev kev tev m_z m_pl ^-1 ^-1 * d * * d^ * * u * * u^ * * y_d * * y_d^ * * y_u * * y_u^ * * v * * v^ * * v^0 * * v^0 * * x * b^0-|b^0 # 1#1 | # 1| # 1 _ max # 1#2#3nucl
. phys .
* b#1 * ( 19#2 ) # 3 # 1#2#3phys . lett . * b#1 * ( 19#2 ) # 3 # 1#2#3phys . lett . *
# 1b * ( 19#2 ) # 3 # 1#2#3phys . rev .
* d#1 * ( 19#2 ) # 3 # 1#2#3phys .
. lett . *
# 1 * ( 19#2 ) # 3 # 1#2#3phys . rep . *
# 1 * ( 19#2 ) # 3 # 1#2#3ann .
rev .
. astrophys . *
# 1 * ( 19#2 ) # 3 # 1#2#3ann . rev .
nucl .
part .
sci . * # 1 * ( 19#2 ) # 3 # 1#2#3mod .
phys .
lett . *
# 1 * ( 19#2 ) # 3 # 1#2#3zeit .
fr physik * c#1 * ( 19#2 ) # 3 # 1#2#3ap .
j. * # 1 * ( 19#2 ) # 3 # 1#2#3ann . phys . * # 1 * ( 19#2 ) # 3 # 1#2#3rev .
mod .
phys . *
# 1 * ( 19#2 ) # 3 # 1#2#3comm .
math .
phys . *
# 1 * ( 19#2 ) # 3 _ i.e. _ _ et al . _ _ e.g. _ _ etc .
_ _ c.f .
_ /#1/ |#1 # 1#1 mctp-03 - 42 +
hep - ph/0310042 +
september 2003 + * @xmath2 as a probe of @xmath1 at the tevatron * + 0.5 cm _
@xmath3michigan center for theoretical physics , university of michigan , ann arbor , mi 48109 , usa + @xmath4department of physics , university of notre dame....
And you have already written the first three sentences of the full article: first , a little theoretical background .
the question of flavor - changing neutral currents ( fcncs ) mediated by higgs bosons was first addressed two decades ago by glashow and weinberg @xcite .
it had always been obvious that the higgs boson of the _ minimal _ standard model could not have flavor - violating couplings since the couplings of fermions to the higgs field _ defines _ the fermion mass eigenstates and thus also defines our notion of flavor ..
Please generate the next two sentences of the article
|
but in models with two ( or more ) higgs fields , the fermion mass eigenbasis can be different from the higgs interaction eigenbasis and thus higgs - mediated fcncs can occur . in order to avoid large fcncs inconsistent with experiment , the authors of ref .
@xcite proposed several solutions .
|
10,799 |
Suppose that you have an abstract for a scientific paper: monotonic convergence is established for a general class of multiplicative algorithms introduced by silvey , titterington and torsney [ _ comm .
statist . theory methods _ * 14 * ( 1978 ) 13791389 ] for computing optimal designs . a conjecture of titterington [ _ appl .
stat . _
* 27 * ( 1978 ) 227234 ] is confirmed as a consequence .
optimal designs for logistic regression are used as an illustration . . . .
And you have already written the first three sentences of the full article: optimal experimental design ( approximate theory ) is a well - developed area , and we refer to kiefer ( @xcite ) , silvey ( @xcite ) , pzman ( @xcite ) and pukelsheim ( @xcite ) for a general introduction and basic results .
we consider computational aspects of optimal designs , focusing on a finite design space @xmath0 .
suppose the probability density or mass function of the response is specified as @xmath1 where @xmath2 is the parameter of interest ..
Please generate the next two sentences of the article
|
let @xmath3 denote the @xmath4 expected fisher information matrix from a unit assigned to @xmath5 with the @xmath6 entry [ the expectation is with respect to @xmath7 @xmath8.\ ] ] the moment matrix , as a function of the design measure @xmath9 , is defined as @xmath10 which is proportional to the fisher information for @xmath11 when the number of units assigned to @xmath5 is proportional to @xmath12 . here
@xmath13 , and @xmath14 denotes the closure of @xmath15 . throughout
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.