id
int64 0
203k
| input
stringlengths 66
4.29k
| output
stringlengths 0
3.83k
|
|---|---|---|
12,200 |
Suppose that you have an abstract for a scientific paper: new upper bounds on direct detection rates have recently been presented by a number of experimental collaborations working on searches for wimps . in this paper
we analyze how the constraints on relic neutralinos which can be derived from these results is affected by the uncertainties in the distribution function of wimps in the halo .
various different categories of velocity distribution functions are considered , and the ensuing implications for supersymmetric configurations derived .
we conservatively conclude that current experimental data do not constrain neutralinos of small mass ( below 50 gev ) . .
And you have already written the first three sentences of the full article: in refs . @xcite we have discussed the cosmological properties of light neutralinos ( _ i.e. _ neutralinos with a mass in the range 6 gev @xmath0 50 gev ) , which originate in supersymmetric schemes where gaugino - mass unification is not assumed . actually , the most remarkable features occur for neutralinos in the mass range : 7 gev @xmath0 25 gev .
namely , for relic neutralinos with these masses , direct and indirect detection rates are considerably high , and at the level of present experimental sensitivities .
furthermore , the range of the predicted values for the rates is quite narrow , at variance with what happens for neutralinos of higher masses , where the expected rates are spread over decades ..
Please generate the next two sentences of the article
|
the properties of light neutralinos with respect to wimp direct measurements were analyzed in refs .
since then , some new results and/or analyses of previous data from experiments of wimp direct searches have appeared @xcite . in the present paper
|
12,201 |
Suppose that you have an abstract for a scientific paper: we compare the semi - analytic models of galaxy formation of fu et al .
( 2010 ) , which track the evolution of the radial profiles of atomic and molecular gas in galaxies , with gas fraction scaling relations derived from a stellar mass - limited sample of 299 galaxies from the cold gass survey .
these galaxies have measurements of the co(1 - 0 ) line from the iram 30-m telescope and the hi line from arecibo , as well as measurements of star formation rates , stellar masses , galaxy sizes and concentration parameters from galex+sdss photometry .
the models provides a good description of how condensed baryons in star - forming galaxies are partitioned into atomic and molecular gas and stars as a function of galaxy stellar mass and stellar surface density .
the models do not reproduce the observed tight relation between stellar surface mass density and bulge - to - disk ratio in these galaxies .
the current implementation of `` radio - mode feedback '' in the models produces trends that disagree strongly with the data . in the models ,
gas cooling shuts down in nearly all galaxies in dark matter halos above a mass of @xmath0 . as a result ,
stellar mass is the observable that best predicts whether a galaxy has little or no neutral gas , i.e. whether a galaxy has been quenched .
in contrast , our data show that quenching is largely _ independent _ of stellar mass . instead , there are clear thresholds in bulge - to - disk ratio and in stellar surface density that demarcate the location of quenched galaxies in our chosen parameter space .
we speculate that the disagreement between the models and the observations may be resolved if radial transport of gas from the outer disk is included as an additional bulge - formation mechanism in the models .
in addition , we propose that processes associated with bulge formation play a key role in depleting the neutral gas in galaxies and that gas accretion is suppressed in a significant fraction of galaxies following the formation of the bulge , even in....
And you have already written the first three sentences of the full article: an important goal in modern galaxy formation is an improved understanding of the physical processes that regulate the rate at which stars form in galaxies .
these processes include the cooling and accretion of gas within dark matter halos , the transformation of the accreted gas into molecular clouds and stars , and the effects of `` feedback '' from massive stars and accreting black holes on the gas in and around galaxies .
the lambda - cold dark matter model provides detailed predictions for how dark matter halos assemble over time . within these halos ,.
Please generate the next two sentences of the article
|
gas will cool and settle into a rotationally - supported disk .
one hotly debated issue is the degree to which gas loses angular momentum to the surrounding dark matter during this process . in many `` semi - analytic '' models , the angular momentum of the gas
|
12,202 |
Suppose that you have an abstract for a scientific paper: in this review the correlations between host galaxy properties and black - hole mass determined from nearby quiescent galaxies are briefly discussed , before proceeding to investigate their application to active galactic nuclei ( agn ) .
the recent advances in estimating the black - hole masses of agn are then reviewed , followed by an examination of the connection between black - hole mass and radio luminosity .
galaxies : fundamental parameters - galaxies : active - quasars : general - quasars : emission lines .
And you have already written the first three sentences of the full article: over the last decade the combination of hst and ground - based data has led to the measurement of the black - hole masses of some 40 inactive galaxies in the nearby universe via gas and stellar dynamics .
these black - hole mass measurements have led to the discovery of correlations between black - hole mass and the properties of the surrounding host galaxy , namely bulge luminosity and stellar velocity dispersion . in parallel to the discovery of these correlations in inactive galaxies , the last few years has also seen a new industry emerge in estimating the black - hole masses of active galaxies . in the first section of this review
i will discuss the recent advances in our understanding of the connection between black - hole mass and host - galaxy properties in both active and inactive galaxies at low redshift . in the second section.
Please generate the next two sentences of the article
|
i will proceed to discuss how black - hole mass estimation in active galaxies has been used to investigate the connection between black - hole mass and radio power .
within the context of the study of agn black - hole masses , the most important aspect of the recent increase in the numbers of nearby quiescent galaxies with black - hole mass measurements has been the discovery of two correlations between black - hole mass and the properties of the surrounding host galaxy .
|
12,203 |
Suppose that you have an abstract for a scientific paper: this paper is part of a series reporting the results of the _ australia telescope eso slice project _ ( atesp ) radio survey obtained at 1400 mhz with the _ australia telescope compact array _ ( atca ) over the region covered by the _
eso slice project _
( esp ) galaxy redshift survey .
the survey consists of 16 radio mosaics with @xmath0 resolution and uniform sensitivity ( @xmath1 noise level @xmath279 @xmath3jy ) over the whole area of the esp redshift survey ( @xmath4 sq .
degrees at @xmath5 ) .
+ here we present the catalogue derived from the atesp survey .
we detected @xmath6 distinct radio sources down to a flux density limit of @xmath7 mjy ( @xmath8 ) , 1402 being sub - mjy sources .
we describe in detail the procedure followed for the source extraction and parameterization .
the internal accuracy of the source parameters was tested with monte carlo simulations and possible systematic effects ( e.g. bandwidth smearing ) have been quantified . .
And you have already written the first three sentences of the full article: recent deep radio surveys ( @xmath9 mjy ) have shown that normalized radio source counts flatten below a few mjy .
this has been interpreted as being due to a new population which does not show up at higher fluxes where counts are dominated by active galactic nuclei ( agn ) . to clarify its nature
it is necessary to get detailed information on the radio properties of normal galaxies in the nearby universe ( z @xmath10 0.15 ) , down to faint flux limits and to have at hand large samples of mjy and sub - mjy sources , for subsequent optical identification and spectroscopic work . to this end.
Please generate the next two sentences of the article
|
we have surveyed a large area ( @xmath11 26 sq .
degr ) with the atca at 1.4 ghz with a bandwidth of @xmath12 mhz .
|
12,204 |
Suppose that you have an abstract for a scientific paper: we present evidence that there is a significant correlation between the fraction of a galaxy s mass that lies in its central black hole and the age of the galaxy s stellar population . since the absorption line indices that are used to estimate the age are luminosity weighted
, they essentially measure the time since the last significant episode of star formation in the galaxy .
the existence of this correlation is consistent with several theories of galaxy formation , including the currently - favoured hierarchical picture of galaxy evolution , which predicts just such a relation between black hole mass and the time since the last burst of merger - induced star formation .
it is not consistent with models in which the massive black hole is primordial , and hence uncoupled from the stellar properties of the galaxy .
[ firstpage ] galaxies : formation , nuclei
quasars : general black hole physics .
And you have already written the first three sentences of the full article: the existence of active galactic nuclei has long been taken as evidence for the existence of massive black holes in the centres of some galaxies ( lynden - bell 1969 ) . however , it is only relatively recently that high spatial resolution studies of the kinematics of galactic nuclei have revealed that essentially all galaxies harbour large central masses [ see ho ( 1999 ) for a review of the evidence ] .
the existence of these observations also means that there are now enough data to study the demographics of massive black holes , in order to seek clues to their origins .
the first significant discovery in this regard is that there is a correlation between the mass of the black hole , @xmath0 , and the mass of the host galaxy s spheroidal component , @xmath1 ..
Please generate the next two sentences of the article
|
although there is a variety of possible biasses in measuring this correlation , it seems broadly to be the case that there is a linear relationship , such that @xmath2 ( magorrian et al .
1998 ) .
|
12,205 |
Suppose that you have an abstract for a scientific paper: we give a simple formula for the signature of a foldable triangulation of a lattice polygon in terms of its boundary .
this yields lower bounds on the number of real roots of certain systems of polynomial equations known as `` wronski systems '' . .
And you have already written the first three sentences of the full article: let @xmath0 be a @xmath1-dimensional _ lattice polytope _ in @xmath2 ; that is , @xmath0 is the convex hull of finitely many points in @xmath3 . further , let @xmath4 be a triangulation of @xmath0 .
we call @xmath4 _ dense _ if the points @xmath5 are precisely the vertices of @xmath4 . moreover , we call @xmath4 _ foldable _ if its dual graph is bipartite ; equivalently , the vertices of the @xmath6-skeleton considered as an abstract graph is @xmath7-colorable @xcite . in this case we may distinguish between `` black '' and `` white '' @xmath1-dimensional cells of @xmath4 . the _ signature _ @xmath8 is defined as the absolute value of the difference of the numbers of black and of white @xmath1-dimensional cells of @xmath4 that have odd normalized volume . the _ normalized volume _ of @xmath0 equals @xmath9 times the euclidean volume of @xmath0 . as @xmath0 is a lattice polytope
the normalized volume is an integer ..
Please generate the next two sentences of the article
|
soprunova and sottile @xcite prove that @xmath8 is a lower bound for the number of real roots of so - called `` wronski systems '' of @xmath1 polynomials over the reals in @xmath1 unknowns associated with @xmath0 and @xmath4 . for @xmath10 that result amounts to the basic fact that every univariate real polynomial of odd degree has at least one real zero . in general , the signature @xmath8 can be interpreted as the topological degree of the map which `` folds '' the foldable triangulation @xmath4 onto the standard simplex of the same dimension ; see @xcite and the references given there . in various cases the soprunova sottile bound is sharp for generic coefficients . here
we are concerned with the planar case @xmath11 , where we provide a new lower bound for the signature , and then an explicit example of a wronski system for which the bound is sharp . in the literature foldable abstract simplicial complexes
|
12,206 |
Suppose that you have an abstract for a scientific paper: we investigate the domain growth and phase separation of hydrodynamically - correct binary immiscible fluids of differing viscosity as a function of minority phase concentration in both two and three spatial dimensions using dissipative particle dynamics .
we also examine the behavior of equal - viscosity fluids and compare our results to similar lattice - gas simulations in two dimensions . .
And you have already written the first three sentences of the full article: over the last few years , the dissipative particle dynamics ( dpd ) model of complex fluids has received considerable attention .
it has matured from its somewhat arbitrary initial formulation into a model with a solid theoretical basis .
furthermore , it has been applied with considerable success to a large number of computer simulations of complex fluid systems such as colloidal suspensions , polymeric fluids , spinodal decomposition of binary immiscible fluids , and amphiphilic fluids ..
Please generate the next two sentences of the article
|
dpd also looks promising for simulating multiphase flows and flow in porous media , and is now considered a useful technique alongside the other complex fluid algorithms : molecular dynamics , lattice - gas automata , and techniques based on the lattice - boltzmann equation . no single technique can yet be applied to all situations , and each has different strengths and weaknesses . while molecular dynamics is in principle the most accurate microscopic approach , in practice it is too slow in both its quantum ( car parinello ) and classical forms because of its excessive detail .
discrete mesoscopic methods developed from lattice - gas automata have had some success , but they too have problems , such as lacking galilean invariance .
|
12,207 |
Suppose that you have an abstract for a scientific paper: ngc 6908 , a s0 galaxy situated in direction of ngc 6907 , was only recently recognized as a distinct galaxy , instead of only a part of ngc 6907 .
we present 21 cm radio synthesis observations obtained with the gmrt and optical images and spectroscopy obtained with the gemini north telescope of this pair of interacting galaxies . from the radio observations we obtained the velocity field and the h i column density map of the whole region containing the ngc 6907/8 pair , and by means of the gemini multi - object spectroscopy we obtained high quality photometric images and @xmath0 resolution spectra sampling the two galaxies . by comparing the rotation curve of ngc 6907 obtained from the two opposite sides around the main kinematic axis
, we were able to distinguish the normal rotational velocity field from the velocity components produced by the interaction between the two galaxies .
taking into account the rotational velocity of ngc 6907 and the velocity derived from the absorption lines for ngc 6908 , we verified that the relative velocity between these systems is lower than 60 km s@xmath1 .
the emission lines observed in the direction of ngc 6908 , not typical of s0 galaxies , have the same velocity expected for the ngc 6907 rotation curve .
some emission lines are inside their equivalent absorption lines , reinforcing the idea they were not formed in ngc 6908 .
finally , the h i profile exhibits details of the interaction , showing three components : one for ngc 6908 , another for the excited gas in the ngc 6907 disk and a last one for the gas with higher relative velocities left behind ngc 6908 by dynamical friction , used to estimate the time when the interaction started in @xmath2 years ago .
galaxies : interactions galaxies : kinematics and dynamics galaxies : photometry radio lines : galaxies . .
And you have already written the first three sentences of the full article: searching for companions among the nearby barred galaxies from the shapley - ames catalog , garca - barreto et al .
( 2003 ) identified ngc 6908 as a discoidal companion of ngc 6907 , 10 kpc away from it .
they estimated this distance based only on their angular separation . but according to these authors , the alignment of the objects could be a mere effect of geometrical superposition , since the narrow band h@xmath3 images of ngc 6907 did not reveal any emission in direction of ngc 6908 ( garca - barreto et al . 1996 ) ..
Please generate the next two sentences of the article
|
surace et al . (
2004 ) recognized ngc 6907 and 6908 as a potential interacting system , but the low resolution of their far - infrared images did not allow any further conclusion . in a recent paper , madore et al .
|
12,208 |
Suppose that you have an abstract for a scientific paper: we study bott - chern cohomology on compact complex non - khler surfaces .
in particular , we compute such a cohomology for compact complex surfaces in class @xmath0 and for compact complex surfaces diffeomorphic to solvmanifolds . .
And you have already written the first three sentences of the full article: for a given complex manifold @xmath1 , many cohomological invariants can be defined , and many are known for compact complex surfaces . among these , one can consider _ bott - chern and aeppli cohomologies_. they are defined as follows : @xmath2 note that the identity induces natural maps @xmath3 \ar[d ] \ar[rd ] & \\
h^{\bullet,\bullet}_{{\overline{{\partial}}}}(x ) \ar[rd ] & h^{\bullet}_{dr}(x;{\mathbb{c } } ) \ar[d ] & h^{\bullet,\bullet}_{{\partial}}(x ) \ar[ld ] \\ & h^{\bullet,\bullet}_{a}(x ) & } \ ] ] where @xmath4 denotes the dolbeault cohomology and @xmath5 its conjugate , and the maps are morphisms of ( graded or bi - graded ) vector spaces . for compact khler manifolds ,
the natural map @xmath6 is an isomorphism ..
Please generate the next two sentences of the article
|
assume that @xmath1 is compact .
the bott - chern and aeppli cohomologies are isomorphic to the kernel of suitable @xmath7th - order differential elliptic operators , see ( * ? ? ?
|
12,209 |
Suppose that you have an abstract for a scientific paper: one of the most popular models for quantitatively understanding the emergence of drug resistance both in bacterial colonies and in malignant tumors was introduced long ago by luria and delbrck . here
, individual resistant mutants emerge randomly during the birth events of an exponentially growing sensitive population . a most interesting limit of this process occurs when the population size @xmath0 is large and mutation rates are low , but not necessarily small compared to @xmath1 . here
we provide a scaling solution valid in this limit , making contact with the theory of levy @xmath2-stable distributions , in particular one discussed long ago by landau .
one consequence of this association is that moments of the distribution are highly misleading as far as characterizing typical behavior .
a key insight that enables our solution is that working in the fixed population size ensemble is not the same as working in a fixed time ensemble .
some of our results have been presented previously in shortened form @xcite .
And you have already written the first three sentences of the full article: in 1943 , luria and delbrck @xcite ( ld hereafter ) used a simple evolutionary model together with laboratory experiments to argue that bacterial resistance ( to bacteriophage , in their specific case ) arose via the selection of pre - existing mutations .
their model postulated a constant probability at which dividing normal cells would have a resistant daughter ; these mutations were assumed to not affect the growth rate until the bacteria were challenged . the ld model and various extensions thereof have been used extensively in recent years to study the emergence of antibiotic - resistant microbes @xcite as well as chemotherapy - resistant cancer cells @xcite
. similar models are used to study the generation of differentiated cells from stem - like precursors @xcite ..
Please generate the next two sentences of the article
|
there has been considerable effort in the mathematics and statistical physics communities devoted to understanding the probability distribution that arises from the ld process @xcite . while early efforts focused on various quasi - deterministic versions of the model where both wild - type and mutant cells or alternatively just the wild - type are assumed to undergo continuous exponential growth , more recently interest has focussed on the fully stochastic model .
a major achievement has very recently been achieved by antal and krapivsky @xcite who solve for the generating function of the full joint distribution of the number of wild - types and mutants as a function of time , starting from a single wild - type individual .
|
12,210 |
Suppose that you have an abstract for a scientific paper: we have performed a keck adaptive optics ( ao ) imaging survey of 25 extrasolar planetary systems discovered by the radial velocity programs . typically , the high - resolution ( fwhm@xmath0 ) near - infrared images are able to detect point sources at @xmath1 at @xmath2 , l and t dwarfs at @xmath3 to @xmath4 , and stars and brown dwarfs at 3 - 10 au and 10 - 100 au from the targets .
the ao images reveal 15 faint sources ( @xmath5 - 20 ) near the stars hd 37124 , hd 168443 , hd 187123 , and hd 190228 out to a search radius of @xmath6 .
we have obtained ao images at a second epoch for five of the candidate companions at keck and gemini observatories .
the resulting measurements of proper motions relative to the primary stars indicate that these five sources are background stars .
given that the four primaries are near the galactic plane ( @xmath7 ) , the remaining faint sources are also likely to be background stars rather than substellar companions .
we present the companion detection limits for each target as a function of separation and compare them to the sensitivities of radial velocity surveys , demonstrating the complementary nature of the two techniques . .
And you have already written the first three sentences of the full article: in the search for planetary companions outside of our solar system , a variety of techniques have been devised and implemented , of which radial velocity monitoring has proven the most successful to date .
such measurements have led to the discovery of planets with masses of @xmath8 @xmath9 and separations of a few au or less around @xmath10 nearby stars ( mayor & queloz 1995 ; marcy & butler 1996 ; cochran et al .
1997 ; noyes et al . 1997 ; udry , mayor , & queloz 2001 ; butler et al ..
Please generate the next two sentences of the article
|
2000 ; fischer et al .
2001b ; tinney et al .
|
12,211 |
Suppose that you have an abstract for a scientific paper: laser cooling of mesoscopic mechanical resonators is of great interest for both fundamental studies and practical applications .
we provide a general framework to describe the cavity - assisted backaction cooling in the strong coupling regime . by studying the cooling dynamics
, we find that the temporal evolution of mean phonon number oscillates as a function of the optomechanical coupling strength depending on frequency mixing .
the further analytical result reveals that the optimal cooling limit is obtained when the system eigenmodes satisfy the frequency matching condition .
the reduced instantaneous - state cooling limits with dynamic dissipative cooling approach are also presented .
our study provides a guideline for optimizing the backaction cooling of mesoscopic mechanical resonators in the strong coupling regime . .
And you have already written the first three sentences of the full article: cavity optomechanics @xcite , which explores the interaction between light and mechanical motion , provides a unique platform for various applications , such as the fundamental test of quantum theory @xcite , quantum information processing @xcite and high - precision measurements @xcite .
recent theoretical and experimental efforts have demonstrated optomechanically induced transparency @xcite , optomechanical storage @xcite , normal mode splitting @xcite , quantum - coherent coupling between optical modes and mechanical modes @xcite , state transfer at different optical ( electromagnetic ) wavelengths @xcite , quantum entanglement @xcite , squeezing @xcite and nonlinear quantum optomechanics @xcite . for most applications ,
it is a prerequisite to cool the mechanical resonators close to the quantum ground state so as to suppress the thermal noise . in the past few years.
Please generate the next two sentences of the article
|
, numerous experiments have demonstrated cooling of mechanical resonators by employing pure cryogenic cooling @xcite , feedback cooling ( active cooling , or cold - damping ) @xcite and backaction cooling ( passive cooling , or self - cooling ) @xcite .
the backaction cooling is proved to be efficient @xcite , especially in the resolved sideband limit , where the mechanical resonance frequency is greater than the decay rate of the optical cavity .
|
12,212 |
Suppose that you have an abstract for a scientific paper: if a given behavior of a multi - agent system corresponds to restrict the phase variable to a invariant manifold , then we define a phase transition as change of physical characteristics such as speed , coordination and structure .
we define such a phase transition as splitting an underlying manifold into two sub - manifolds with distinct dimensionalities around the singularity where the transition is physically represented on . here
, we propose a method of detecting phase transitions and splitting the manifold into transitions free sub - manifolds .
therein , we utilize a relationship between curvature and singular value ratio of points sampled in a curve , and then extend the assertion to higher dimensions using the shape operator .
then we attest that , the same transition can also be approximated by singular value ratios computed locally over the data in a neighborhood on the manifold .
we validate the transitions detection method using one particle simulation and three real world examples .
kelum gajamannage erik m. bollt ( communicated by the associate editor name ) .
And you have already written the first three sentences of the full article: multi - agent systems such as crowds of human @xcite , schools of fish @xcite , flocks of birds @xcite , colonies of molds @xcite and ants @xcite often exhibit discrete phase transitions due to variations of the driven force of interaction among members @xcite .
specially , detecting transitions in humans @xcite is an ongoing research problem @xcite .
abrupt changes upon variation of some parameters such as speed , coordination and structure @xcite shift the system from one state to another @xcite ..
Please generate the next two sentences of the article
|
numerous types of swarm decisions which determine the group dynamics are not only influenced by the intrinsic social interaction among members @xcite , but also by some outside factors such as threats @xcite and presence of predators or food sources @xcite .
however , with a majority of observation done via videos , the classical approaches of detecting transitions , such as , tracking individuals and monitoring their dynamics , are constrained by the size of the group and the scale of the problem @xcite .
|
12,213 |
Suppose that you have an abstract for a scientific paper: we study the asymptotic behavior of the principal eigenvector and eigenvalue of the random conductance laplacian in a large domain of @xmath0 ( @xmath1 ) with zero dirichlet condition .
we assume that the conductances @xmath2 are positive i.i.d .
random variables , which fulfill certain regularity assumptions near zero .
if @xmath3<\infty \}<1/4 $ ] , then we show that for almost every environment the principal dirichlet eigenvector asymptotically concentrates in a single site and the corresponding eigenvalue scales subdiffusively .
the threshold @xmath4 is sharp . indeed , other recent results imply that for @xmath5 the top of the dirichlet spectrum homogenizes . our proofs are based on a spatial extreme value analysis of the local speed measure , borel - cantelli arguments , the rayleigh - ritz formula , results from percolation theory , and path arguments . .
And you have already written the first three sentences of the full article: in dimensions greater than one , the spectrum of the i.i.d . random conductance laplacian displays a sharp transition between complete localization and complete homogenization .
this is the result of the present paper in combination with recent papers from flegel , heida , and slowik @xcite and neukamm , schffner , and schlmerkemper @xcite .
while the other two papers cover spectral homogenization , we investigate the localization phase ..
Please generate the next two sentences of the article
|
a simple moment condition distinguishes between the two phases . more precisely , we investigate the spectrum of the laplacian @xmath6 associated with the random conductance model on the euclidean lattice @xmath0 .
the laplacian acts on real - valued functions @xmath7 as @xmath8 we assume that the conductances @xmath2 are positive , independent and identically distributed ( i.i.d . )
|
12,214 |
Suppose that you have an abstract for a scientific paper: we have conducted a detailed analysis of the emission geometry of a handful of radio pulsars that have prominent , multiple - component profiles at meter wavelengths . from careful determination of the total number of emission components and their locations in pulse longitude , we find that all of the six pulsars show clear evidence for retardation and aberration effects in the conal emission beams . using this information , coupled with a dipolar field geometry , we obtain estimates of the height and transverse location in the magnetosphere , for each of the emitting cones in these pulsars .
these results support our earlier conclusions for psr b0329 + 54 in that we find successive outer cones ( in cases of multi - cone pulsars ) being emitted at higher altitudes in the magnetosphere .
the range of inferred heights is from @xmath0 200 to @xmath0 2200 km .
the set of `` active '' field lines from which the conal emissions originate are located in the region from @xmath0 0.22 to @xmath0 0.74 of the polar cap radius . at the neutron star surface , these conal rings map to radii of a few to several tens of meters and
the separation between successive rings is about 10 to 20 meters .
we discuss the implications of these findings for the understanding of the pulsar emission geometry and for current theories and models of the emission mechanism . .
And you have already written the first three sentences of the full article: radio emission from a pulsar is believed to originate in the open field line region of the polar cap of the neutron star .
the size , shape and location of regions of radio emission in the average profiles of pulsars is thus expected to reflect the arrangement of emission regions in the pulsar magnetosphere .
pulsar average profiles exhibit a great diversity in shape , and their classification based on the number of emission components is a useful starting point to study the emission characteristics of pulsars ..
Please generate the next two sentences of the article
|
rankin ( 1993 , 1990 ; and references therein ) has carried out such a detailed classification , and has come up with the conclusion that there are two kinds of emission components core and conal in pulsar profiles , which result from two distinct types of emission mechanisms .
further , rankin proposes that the conal components arise from two nested hollow cones of emission , which along with a central core emission region , make up the complete pulsar emission beam .
|
12,215 |
Suppose that you have an abstract for a scientific paper: we introduce and study some affine hecke algebras of type ade , generalising the affine hecke algebras of gl .
we construct irreducible calibrated representations and describe the calibrated spectrum .
this is done in terms of new families of combinatorial objects equipped with actions of the corresponding weyl groups .
these objects are built from and generalise the usual standard young tableaux , and are controlled by the considered affine hecke algebras . by restriction and limiting procedure
, we obtain several combinatorial models for representations of finite hecke algebras and weyl groups of type ade .
representations are constructed by explicit formulas , in a seminormal form . .
And you have already written the first three sentences of the full article: [ [ section ] ] * 1 . * + + + + the classical approach to the representation theory of the symmetric group involves the combinatorial notion of partitions and associated standard tableaux .
a classical explicit realisation of the irreducible representations is often referred to as the seminormal form " and was already given by a. young @xcite ( see also @xcite ) . in this realisation , a distinguished ( seminormal " ) basis of the irreducible representation spaces
is indexed by standard tableaux and is such that a certain set of commuting elements , the jucys murphy elements , acts as diagonal matrices @xcite ..
Please generate the next two sentences of the article
|
analogues of the seminormal representations of the symmetric group have been given explicitly , using combinatorial constructions , in many other situations .
we refer to @xcite . in all these situations , analogues of jucys
|
12,216 |
Suppose that you have an abstract for a scientific paper: a series of weak - coupling perturbation theories which include the lowest - order vertex corrections are applied to the attractive holstein model in infinite dimensions .
the approximations are chosen to reproduce the iterated perturbation theory in the limit of half - filling and large phonon frequency ( where the holstein model maps onto the hubbard model ) .
comparison is made with quantum monte carlo solutions to test the accuracy of different approximation schemes . .
And you have already written the first three sentences of the full article: the theory of superconductivity , as first developed by bardeen , cooper , and schrieffer,@xcite and then generalized to strong coupling by migdal,@xcite eliashberg,@xcite , and others@xcite , has proven to be one of the most accurate theories of solid - state physics .
properties of conventional low-@xmath0 materials are typically explained to accuracies of one percent or better .
newly discovered materials , however , which have moderate @xmath0 s , do not fit into the parameter regimes studied so successfully in the 50 s and 60 s ..
Please generate the next two sentences of the article
|
these materials , such as the a15 compounds , ba@xmath1k@xmath2bio@xmath3 , and k@xmath3c@xmath4 have large phonon energy scales relative to the inverse electronic density of states , so that both the effect of the energy dependence of the bare electronic density of states ( i. e. , nonconstant density of states ) , and the effect of vertex corrections may become important in their description .
we examine here a series of different weak - coupling perturbation theories that include both the effects of nonconstant density of states and of vertex corrections to ascertain what methods should be used for real materials calculations of these higher @xmath0 compounds . since the most popular implementation of migdal - eliashberg theory is manifestly particle - hole symmetric ( because of the neglect of the energy dependence of the electronic density of states ) it is not clear what the most accurate approximation scheme is when the electron filling is doped away from half - filling and the energy dependence of the electronic density of states becomes important .
|
12,217 |
Suppose that you have an abstract for a scientific paper: ontologies in the biomedical domain are numerous , highly specialized and very expensive to develop .
thus , a crucial prerequisite for ontology adoption and reuse is effective support for exploring and finding _ existing _ ontologies . towards that goal ,
the national center for biomedical ontology ( ncbo ) has developed bioportal an online repository designed to support users in exploring and finding more than @xmath0 existing biomedical ontologies . in @xmath1
, bioportal represents one of the largest portals for exploration of semantic biomedical vocabularies and terminologies , which is used by many researchers and practitioners .
while usage of this portal is high , we know very little about how exactly users search and explore ontologies and what kind of usage patterns or user groups exist in the first place .
deeper insights into user behavior on such portals can provide valuable information to devise strategies for a better support of users in exploring and finding existing ontologies , and thereby enable better ontology reuse . to that end , we study and group users according to their browsing behavior on bioportal using data mining techniques .
additionally , we use the obtained groups to characterize and compare exploration strategies across ontologies . in particular , we were able to identify seven distinct browsing - behavior types , which all make use of different functionality provided by bioportal .
for example , _ search explorers _ make extensive use of the search functionality while _ ontology tree explorers _ mainly rely on the class hierarchy to explore ontologies .
further , we show that specific characteristics of ontologies influence the way users explore and interact with the website .
our results may guide the development of more user - oriented systems for ontology exploration on the web .
< ccs2012 > < concept > < concept_id>10002951.10003260.10003277.10003280</concept_id > < concept_desc > information systems web log analysis</concept_desc > <....
And you have already written the first three sentences of the full article: facilitating reuse on the semantic web requires support for effectively finding and exploring existing semantic resources such as ontologies or taxonomies . particularly in the biomedical domain , where ontologies are highly specialized , costly and often created collaboratively by large groups of domain experts ,
_ identifying and finding existing semantic vocabularies and terminologies _ is crucial . to support researchers and practitioners in this task ,
the national center for biomedical ontology ( ncbo ) has developed bioportal_the world s most comprehensive online repository of biomedical ontologies _ @xcite . [ cols= " < , < , < " , ] [ tab : cluster counts ].
Please generate the next two sentences of the article
|
in this paper we have analyzed , modeled and clustered the browsing behavior of users on bioportal .
in particular , we have grouped users according to their browsing behavior in section [ subsec : res : clusters ] and compared how users explore ontologies in section [ subsec : res : browsing_comparison ] . * differences in browsing - behavior types . *
|
12,218 |
Suppose that you have an abstract for a scientific paper: the modified newtonian dynamics ( mond ) , suggested by milgrom as an alternative to dark matter , implies that isothermal spheres with a fixed anisotropy parameter should exhibit a near perfect relation between the mass and velocity dispersion of the form @xmath0 .
this is consistent with the observed faber - jackson relation for elliptical galaxies a luminosity - velocity dispersion relation with large scatter .
however , the observable global properties of elliptical galaxies comprise a three parameter family ; they lie on a `` fundamental plane '' in a logarithmic space consisting of central velocity dispersion , effective radius ( @xmath1 ) , and luminosity .
the scatter perpendicular to this plane is significantly less than that about the faber - jackson relation .
i show here that , in order to match the observed properties of elliptical galaxies with mond , models must deviate from being strictly isothermal and isotropic ; such objects can be approximated by high - order polytropic spheres with a radial orbit anisotropy in the outer regions .
mond imposes boundary conditions on the inner newtonian regions which restrict these models to a dynamical fundamental plane of the form @xmath2 where the exponents may differ from the newtonian expectations ( @xmath3 , @xmath4 ) .
scatter about this plane is relatively insensitive to the necessary deviations from homology .
epsf galaxies : elliptical galaxies : kinematics and dynamics dark matter , gravitation .
And you have already written the first three sentences of the full article: on a phenomenological level , the most successful alternative to cosmic dark matter is the modified newtonian dynamics ( mond ) proposed by milgrom ( 1983a ) .
the basic idea is that the deviation from newtonian gravity or dynamics occurs below a fixed acceleration scale a proposal which is supported in a general way by the fact that discrepancy between the classical dynamical mass and the observable mass in astronomical systems does seem to appear at accelerations below @xmath5 cm / s@xmath6 ( sanders 1990 , mcgaugh 1998 ) .
the fact that this acceleration scale is comparable to the present value of the hubble parameter multiplied by the speed of light ( @xmath7 ) suggests a cosmological basis for this phenomenology ..
Please generate the next two sentences of the article
|
mond , in a sense , is designed to reproduce flat extended rotation curves of spiral galaxies and a luminosity - rotation velocity relationship of the observed form , @xmath8 ( the tully - fisher relation ) .
but apart from these aspects which are built - in " , the prescription also successfully predicts the observed form of galaxy rotation curves from the observed distribution of stars and gas with reasonable values for the mass - to - light ratio of the stellar component ( begeman et al .
|
12,219 |
Suppose that you have an abstract for a scientific paper: we describe fully relativistic three dimensional calculations of the slowing down and spreading of a relativistic jet by an external medium like the ism .
we calculate the synchrotron spectra and light curves using the conditions determined by the hydrodynamic calculations .
preliminary results with a moderate resolution are presented here .
higher resolution calculations are in progress . .
And you have already written the first three sentences of the full article: the level of beaming in grbs is one of the most interesting open questions in this subject .
the relativistic flow which drives a grb may range from isotropic to strongly collimated into a narrow opening angle .
the degree of collimation ( beaming ) of the outflow has many implications on most aspects grb research , such as the requirements from the `` inner engine '' , the energy release and the event rate . during the prompt emission.
Please generate the next two sentences of the article
|
the lorentz factor of the flow is very high ( @xmath0 ) , and due to relativistic aberration of light , only a narrow angle of @xmath1 around the line of sight ( los ) is visible . during the afterglow stage , the flow decelerates and an increasingly larger angle becomes visible .
as long as @xmath2 an outflow collimated within an angle @xmath3 around the los produces the same observed radiation as if it were part of a spherical outflow .
|
12,220 |
Suppose that you have an abstract for a scientific paper: direct time - resolved spectral fitting has been performed on continuous _ rxte _ monitoring of seven seyfert 1 galaxies in order to study their broadband spectral variability and fe k@xmath0 variability characteristics on time scales of days to years .
variability in the fe k@xmath0 line is not detected in some objects but is present in others , e.g. , in ngc 3516 , ngc 4151 and ngc 5548 there are systematic decreases in line flux by factors of @xmath125 over 34 years .
the fe k@xmath0 line varies less strongly than the broadband continuum , but , like the continuum , exhibits stronger variability towards longer time scales .
relatively less model - dependent broadband fractional variability amplitude ( @xmath2 ) spectra also show weaker line variability compared to the continuum variability .
comparable systematic long - term decreases in the line and continuum are present in ngc 5548 .
overall , however , there is no evidence for correlated variability between the line and continuum , severely challenging models in which the line tracks continuum variations modified only by a light - travel time delay .
local effects such as the formation of an ionized skin at the site of line emission may be relevant .
the spectral fitting and @xmath2 spectra both support spectral softening as continuum flux increases . .
And you have already written the first three sentences of the full article: there is substantial evidence to indicate that the central regions of seyfert 1 active galactic nuclei ( agn ) consist of a geometrically - thin , optically - thick accretion disk surrounding a supermassive ( 10@xmath3@xmath4 ) black hole . in the leading models ,
the inner disk is surrounded by a hot , optically - thin corona that compton - upscatters soft photons thermally emitted from the disk to produce an x - ray power - law continuum over the range 1100 kev , though the geometry of the corona remains uncertain ( e.g. , haardt , maraschi & ghisellini 1994 ) .
furthermore , some optically thick material , such as the accretion disk , intercepts and reprocesses some of the x - rays , producing the so - called compton reflection hump above @xmath110 kev and a strong fe k@xmath0 fluorescent emission line at 6.4 kev ( guilbert & rees 1988 , george & fabian 1991 ) . though the exact configuration of accreting material throughout the central engine is not known , the fe k@xmath0 line , as a primary signature of the reprocessing , serves as a potential tool to trace the distribution of accreting gas ..
Please generate the next two sentences of the article
|
single - epoch spectral fitting has revealed a variety of profiles for the fe k@xmath0 line . in some seyfert 1
galaxies , the line is seen to be relativistically broadened ( e.g. , fwzi up to 100,000 km s@xmath5 in the well - studied broad line profile of mcg6 - 30 - 15 , tanaka et al .
|
12,221 |
Suppose that you have an abstract for a scientific paper: we discuss the x - ray properties of the interacting system arp 284 , consisting of the active nuclear starburst galaxy ngc 7714 and its post - starburst companion ngc 7715 .
a morphological signature of the interaction , thought to have started @xmath0 myr ago , is an asymmetric stellar ring dominating the intensity profile of ngc 7714 in the inner disk ( @xmath1 exponential scale lengths ) . in agreement to previous _
einstein_-data our rosat pspc exposure shows the x - ray emission of arp284 to be confined to ngc 7714 . the bulk of the intrinsic x - ray luminosity in the rosat 0.12.4 kev band can be accounted for by thermal emission from hot ( @xmath2 k ) gas and amounts to @xmath3 .
follow - up observations with the rosat hri revealed two distinct extended emitting regions contributing to the x - ray luminosity in ngc 7714 .
the more luminous of them ( @xmath4 ) coincides with the central starburst nucleus and can be explained this way .
the fainter one ( @xmath5 ) is located @xmath6 off - center and does not have any conspicuous optical counterpart .
it is , likely , located at the borderline between the stellar ring and a massive ( @xmath7 ) -bridge further to the east possibly intersecting ngc 7714 .
the and x - ray morphology and the extensive starburst nature of the nuclear energy source suggest different scenarios for the formation of the eastern emission spot . the possibilities of ( i ) collisional heating of the outlying gas by a starburst - driven nuclear wind and ( ii ) infall of -clouds from the bridge onto the disk of ngc 7714 are discussed . .
And you have already written the first three sentences of the full article: observational work during the past two decades has established the paradigm of interaction - induced activity in galaxies ( cf .
fricke & kollatschny 1989 ; sulentic 1990 ) .
galaxy interactions were initially studied theoretically by simplified n - body simulations ( toomre & toomre 1972 ) and investigated in more detail by n - body / sph models ( barnes & hernquist 1996 and references therein ) ..
Please generate the next two sentences of the article
|
interactions are linked to a variety of physical processes such as nuclear starbursts , non - thermal nuclear activity , and morphological evolution into different classes of galaxies ( barnes & hernquist 1992 ) .
already , collisionless calculations can simulate the transformation of merged spirals into ellipticals ( schweizer 1982 ) and the formation of tidal dwarf galaxies ( duc & mirabel 1994 ; sanders & mirabel 1996 ) .
|
12,222 |
Suppose that you have an abstract for a scientific paper: far infrared cooling lines are ubiquitous features in the spectra of star forming galaxies
. surveys of redshifted fine - structure lines provide a promising new tool to study structure formation and galactic evolution at redshifts including the epoch of reionization as well as the peak of star formation . unlike neutral hydrogen surveys , where the 21 cm line is the only bright line , surveys of red - shifted fine - structure lines suffer from confusion generated by line broadening , spectral overlap of different lines , and the crowding of sources with redshift .
we use simulations to investigate the resulting spectral confusion and derive observing parameters to minimize these effects in pencil - beam surveys of red - shifted far - ir line emission .
we generate simulated spectra of the 17 brightest far - ir lines in galaxies , covering the 150 to 1300 @xmath0 m wavelength region corresponding to redshifts @xmath1 , and develop a simple iterative algorithm that successfully identifies the 158@xmath0 m [ cii ] line and other lines .
although the [ cii ] line is a principal coolant for the interstellar medium , the assumption that the brightest observed lines in a given line of sight are always [ cii ] lines is a poor approximation to the simulated spectra once other lines are included .
blind line identification requires detection of fainter companion lines from the same host galaxies , driving survey sensitivity requirements .
the observations require moderate spectral resolution @xmath2 with angular resolution between 20 and 10 , sufficiently narrow to minimize confusion yet sufficiently large to include a statistically meaningful number of sources . .
And you have already written the first three sentences of the full article: line emission or absorption is a promising probe of the high - redshift universe .
considerable theoretical and instrumental effort has been devoted to the use of the redshifted 21 cm line of neutral hydrogen in such a fashion ( see @xcite for a recent review ) .
comparable observations using atomic or molecular lines at far - infrared wavelengths have seen less development ..
Please generate the next two sentences of the article
|
recent advances in far - ir instrumentation , combining sensitive receivers with large collecting area , have led to the detection of far - ir lines in individual sources at cosmological distances , raising the prospects for a future generation of far - ir line surveys as a probe of the high - redshift universe .
infrared fine structure lines are important coolants of the neutral and ionized gas phases of normal and starburst galaxies .
|
12,223 |
Suppose that you have an abstract for a scientific paper: the computational difficulty of six - dimensional neutrino radiation hydrodynamics has spawned a variety of approximations , provoking a long history of uncertainty in the core - collapse supernova explosion mechanism . under the auspices of the terascale supernova initiative
, we are honoring the physical complexity of supernovae by meeting the computational challenge head - on , undertaking the development of a new adaptive mesh refinement code for self - gravitating , six - dimensional neutrino radiation magnetohydrodynamics .
this code called _ genasis , _ for _ gen_eral _ a_strophysical _ si_mulation _ s_ystem is designed for modularity and extensibility of the physics .
presently in use or under development are capabilities for newtonian self - gravity , newtonian and special relativistic magnetohydrodynamics ( with ` realistic ' equation of state ) , and special relativistic energy- and angle - dependent neutrino transport including full treatment of the energy and angle dependence of scattering and pair interactions . .
And you have already written the first three sentences of the full article: a core - collapse supernova is a colossal explosion resulting from the death of a massive star . at its peak
, a supernova can outshine the combined output of the billion or so stars in its host galaxy .
the star s demise is brought about by an accumulation of iron the final product of stellar burning in the star s core . collapsing catastrophically.
Please generate the next two sentences of the article
|
, the core increases in average density by about a factor of a million in only half a second .
this usually results in a hot and dense neutron star with a mass about the same as the sun , but compressed to a size of tens of kilometers .
|
12,224 |
Suppose that you have an abstract for a scientific paper: recently , javaraiah ( 2012a ) analyzed the combined greenwich and solar optical observing network ( soon ) sunspot group data during the period 18742011 and studied variations in the annual numbers ( counts ) of the small ( maximum area @xmath0 millionth of solar hemisphere , msh ) , large ( @xmath1 msh ) , and big ( @xmath2 msh ) sunspot groups . here that analysis is extended and studied variations in the mean maximum sizes ( the mean values of maximum areas ) of the aforementioned three classes of sunspot groups and also their combination .
it is found that there is no significant correlation between the mean maximum size of any class of sunspot groups and the international sunspot number ( @xmath3 ) , probably due to in a given time interval small sunspot groups / sunspots outnumber the large ones .
a pattern of an approximate 9-year period cycle is seen in the variations of the mean maximum sizes of the large and the big sunspot groups during a solar cycle . on
long - time scales it is found that there exists a strong 130 or more years cycle in the variation of the mean size of the small sunspot groups , whereas there is a hint on the existence of @xmath4 44-year cycles in the variations of the mean maximum sizes of the large and the big sunspot groups . during the decline phase of cycle 23 , there was a scarcity in the sunspot groups whose @xmath537 msh , which may be related to the slow growth of sunspot groups during this period . during the minimum between cycles 23 and 24
may be due to the presence of a number of small sunspot groups whose @xmath6 was larger than that of whose @xmath537 , the relatively large size coronal holes were present at low - latitudes and the total solar irradiance was very low . solar magnetic field , solar activity , solar cycle = 0.5 cm .
And you have already written the first three sentences of the full article: the study of variations in solar activity is important for understanding the mechanism behind the solar activity , and because of solar activity affects space weather and it may also have a contribution in earth s climate change ( e.g. , * ? ? ? * ; * ? ? ?
although it is well believed that the solar cycle results from generation of strong toroidal magnetic fields in the sun , with a main period of about 22-years , by combined effects of convection and differential rotation in the sun ( @xmath7 , * ? ? ?
* ) , it is not known exactly what causes solar cycle ..
Please generate the next two sentences of the article
|
because of the long record of observations , sunspot measurements constitute a primary source of information to better understand the level and nature of solar activity .
it is well - known that the dynamic properties , such as rotation rate and meridional motion , of sunspot groups depend on their sizes .
|
12,225 |
Suppose that you have an abstract for a scientific paper: the site survey for the advanced technology solar telescope concluded recently after more than two years of data gathering and analysis .
six locations , including lake , island and continental sites , were thoroughly probed for image quality and sky brightness .
the present paper describes the analysis methodology employed to determine the height stratification of the atmospheric turbulence .
this information is crucial because day - time seeing is often very different between the actual telescope aperture ( @xmath030 m ) and the ground .
two independent inversion codes have been developed to analyze simultaneously data from a scintillometer array and a solar differential image monitor .
we show here the results of applying them to a sample subset of data from may 2003 , which was used for testing .
both codes retrieve a similar seeing stratification through the height range of interest .
a quantitative comparison between our analysis procedure and actual _ in situ _ measurements confirms the validity of the inversions .
the sample data presented in this paper reveal a qualitatively different behavior for the lake sites ( dominated by high - altitude seeing ) and the rest ( dominated by near - ground turbulence ) . .
And you have already written the first three sentences of the full article: the advanced technology solar telescope ( atst , @xcite @xcite ) , with its 4-meter aperture , will be the largest solar telescope in the world .
a suite of advanced instrumentation will allow for unprecedented resolution and precision imaging , spectroscopy and polarimetry at visible and infrared wavelengths . in order to address the most challenging problems in modern solar physics , atst s
highest priorities are oriented towards high - resolution and coronal science ..
Please generate the next two sentences of the article
|
obviously , these are aspects in which the site selection will have a strong impact and therefore should be considered very carefully in the decision of the telescope location .
the atst site survey working group ( sswg ) was created in 2000 with an open call to the international community .
|
12,226 |
Suppose that you have an abstract for a scientific paper: generally , the conditions for deep sub - doppler laser cooling do not match the conditions for the strong atomic localization that takes a place in deeper optical potential and , in consequence , leads to larger temperature . moreover , for a given detuning in a deep optical potential the secular approximation which is usually used for quantum description of laser cooling becomes no more valid .
here we perform an analysis of atomic localization in optical potential based on a full quantum approach for atomic density matrix .
we also show that the laser cooling in a deep far - off detuned optical potential , created by a light field with a polarization gradient , can be used as an alternative method for forming high contrast spatially localized structures of atoms for the purposes of atom lithography and atomic nanofabrication .
finally , we perform an analysis of the possible limits for the width and the contrast of localized atomic structures that can in principle be reached by this type of the light mask . .
And you have already written the first three sentences of the full article: laser cooling and manipulation of neutral atoms is one of the priority field of atom optics . in the recent time
the major developments and success have been obtained in atom lithography and direct deposition of atoms utilizing light fields as an immaterial optical mask for atomic beam @xcite . in most nanofabrication experiments ,
atomic structures are realized by far off detuned periodical conservative potential created by intense laser fields acting as an array of immaterial light lenses for the atoms ..
Please generate the next two sentences of the article
|
the influence of the spontaneous emission on the focusing is considered to be negligible because of the large light detuning and short interaction times .
in essence , the atom trajectory affected by conservative dipole force without any loses ( or dissipation ) of energy in the atomic beam . in this case
|
12,227 |
Suppose that you have an abstract for a scientific paper: photonic crystals have great potential for use as laser - driven accelerator structures .
a photonic crystal is a dielectric structure arranged in a periodic geometry . like
a crystalline solid with its electronic band structure , the modes of a photonic crystal lie in a set of allowed photonic bands .
similarly , it is possible for a photonic crystal to exhibit one or more photonic band gaps , with frequencies in the gap unable to propagate in the crystal .
thus photonic crystals can confine an optical mode in an all - dielectric structure , eliminating the need for metals and their characteristic losses at optical frequencies .
we discuss several geometries of photonic crystal accelerator structures .
photonic crystal fibers ( pcfs ) are optical fibers which can confine a speed - of - light optical mode in vacuum
. planar structures , both two- and three - dimensional , can also confine such a mode , and have the additional advantage that they can be manufactured using common microfabrication techniques such as those used for integrated circuits .
this allows for a variety of possible materials , so that dielectrics with desirable optical and radiation - hardness properties can be chosen .
we discuss examples of simulated photonic crystal structures to demonstrate the scaling laws and trade - offs involved , and touch on potential fabrication processes .
_ submitted to particale accelerator conference ( pac 2003 ) , may 1216 , 2003 , portland , oregon ( ieee ) _ .
And you have already written the first three sentences of the full article: the extraordinary electric fields available from laser systems make laser - driven charged particle acceleration an exciting possibility .
practical vacuum laser acceleration requires a guided - mode structure capable of confining a speed - of - light ( sol ) mode and composed entirely of dielectric materials , and photonic crystals provide a means to achieve this capability .
a photonic crystal is a structure with permittivity periodic in one or more of its dimensions . as described in @xcite , optical modes in a photonic crystal form bands , just as electronic states do in a crystalline solid ..
Please generate the next two sentences of the article
|
similarly , a photonic crystal can also exhibit one or more photonic band gaps ( pbg s ) , with frequencies in the gap unable to propagate in the crystal .
confined modes can be obtained by introducing a defect into a photonic crystal lattice . since frequencies in the bandgap
|
12,228 |
Suppose that you have an abstract for a scientific paper: in this paper , we study the entanglement properties of a spin-1 model the exact ground state of which is given by a matrix product state .
the model exhibits a critical point transition at a parameter value @xmath0 .
the longitudinal and transverse correlation lengths are known to diverge as @xmath1 .
we use three different entanglement measures @xmath2 ( the one - site von neumann entropy ) , @xmath3 ( the two - body entanglement ) and @xmath4 ( the generalized global entanglement ) to determine the entanglement content of the mp ground state as the parameter @xmath5 is varied .
the entanglement length , associated with @xmath3 , is found to diverge in the vicinity of the quantum critical point @xmath0 .
the first derivative of the entanglement measure @xmath6 @xmath7 w.r.t .
the parameter @xmath5 also diverges .
the first derivative of @xmath4 w.r.t .
@xmath5 does not diverge as @xmath1 but attains a maximum value at @xmath0 . at the qcp itself
all the three entanglement measures become zero .
we further show that multipartite correlations are involved in the qpt at @xmath0 .
department of physics bose institute 93/1 , acharya prafulla chandra road kolkata - 700 009 , india .
And you have already written the first three sentences of the full article: the entanglement characteristics of the ground states of many body hamiltonians describing condensed matter systems constitute an important area of study in quantum information theory .
entanglement is an essential resource in quatum computation and communication protocols .
condensed matter , specially , spin systems have been proposed as candidate systems for the realization of some of the protocols ..
Please generate the next two sentences of the article
|
entanglement provides a measure of non - local quantum correlations in the system and it is of significant interest to determine how the correlations associated with the ground state of the system change as one or more than one parameter of the system is changed .
the focus on ground state characteristics arises from the possibility of quantum phase transitions ( qpts ) which occur at temperature @xmath8 ( when the system is in its ground state ) and are driven solely by quantum fluctuations @xcite .
|
12,229 |
Suppose that you have an abstract for a scientific paper: we present new radio continuum observations of two dwarf starburst galaxies , ngc3125 and ngc5408 , with observations at 4.80ghz ( 6 cm ) and 8.64ghz ( 3 cm ) , taken with the australia telescope compact array ( atca ) .
both galaxies show a complex radio morphology with several emission regions , mostly coincident with massive young star clusters .
the radio spectral indices of these regions are negative ( with @xmath0 ) , indicating that the radio emission is dominated by synchrotron emission associated with supernova activity from the starburst .
one emission region in ngc5408 has a flatter index ( @xmath1 ) indicative of optically thin free - free emission , which could indicate it is a younger cluster .
consequently , in these galaxies we do not see regions with the characteristic positive spectral index indicative of optically obscured star - formation regions , as seen in other dwarf starbursts such as hen 2 - 10 .
galaxies : individual : ngc3125 , ngc5408 galaxies : starburst galaxies : radio emission .
And you have already written the first three sentences of the full article: dwarf starburst galaxies are the more numerous and fainter counterparts of traditional starburst galaxies
. dwarf starbursts will have a particularly important role in the energizing and polluting of the intergalactic medium through galactic winds , as , because of their low escape velocities , even a moderate starburst event in a dwarf galaxy can result in the expulsion of a large fraction of the nuclear processed material in a superwind or outflow ( dekel & silk 1986 ; mac low & ferrara 1999 ; strickland & stevens 2000 ) .
understanding the complexities of starburst processes in dwarf galaxies is therefore an important step in understanding the feedback processes between star - formation and galactic evolution ..
Please generate the next two sentences of the article
|
radio continuum observations of starburst galaxies are particularly useful in studying the star - formation processes , suffering little of the extinction that complicates matters in the optical and uv , which may appear to be more suitable wavebands for studying young massive star populations ( see hopkins et al .
2001 for a discussion of the merits of different wavelength regimes for finding star formation rates ) .
|
12,230 |
Suppose that you have an abstract for a scientific paper: revealing hidden features in unlabeled data is called unsupervised feature learning , which plays an important role in pretraining a deep neural network . here
we provide a statistical mechanics analysis of the unsupervised learning in a restricted boltzmann machine with binary synapses .
a message passing equation to infer the hidden feature is derived , and furthermore , variants of this equation are analyzed .
a statistical analysis by replica theory describes the thermodynamic properties of the model .
our analysis confirms an entropy crisis preceding the non - convergence of the message passing equation , suggesting a discontinuous phase transition as a key characteristic of the restricted boltzmann machine .
continuous phase transition is also confirmed depending on the embedded feature strength in the data .
the mean - field result under the replica symmetric assumption agrees with that obtained by running message passing algorithms on single instances of finite sizes .
interestingly , in an approximate hopfield model , the entropy crisis is absent , and a continuous phase transition is observed instead .
we also develop an iterative equation to infer the hyper - parameter ( temperature ) hidden in the data , which in physics corresponds to iteratively imposing nishimori condition .
our study provides insights towards understanding the thermodynamic properties of the restricted boltzmann machine learning , and moreover important theoretical basis to build simplified deep networks . .
And you have already written the first three sentences of the full article: standard machine learning algorithms require a huge number of training examples to uncover hidden features , while humans and other animals can learn new concepts from only a few examples without any supervision signal @xcite .
learning hidden features in unlabeled training examples is called unsupervised learning . understanding how the number of examples confines the learning process is of fundamental importance in both cognitive neuroscience and machine learning @xcite .
as already observed in training of deep neural networks , unsupervised pretraining can significantly enhance the final performance , because the unsupervised pretraining provides a good initial region in parameter space from which the final fine - tuning starts @xcite . however , there are few theoretical works addressing how unsupervised learning extracts hidden features ..
Please generate the next two sentences of the article
|
one potential reason is that the unsupervised learning process in a deep neural network is typically very complicated .
hence , understanding the mechanism of unsupervised learning in simple models is of significant importance .
|
12,231 |
Suppose that you have an abstract for a scientific paper: over the last few years , several computational techniques have been devised to recover protein complexes from the protein interaction ( ppi ) networks of organisms .
these techniques model dense " subnetworks within ppi networks as complexes .
however , our comprehensive evaluations revealed that these techniques fail to reconstruct many ` gold standard ' complexes that are sparse " in the networks ( only @xmath0 recovered out of @xmath1 known yeast complexes embedded in a network of @xmath2 interactions among @xmath3 proteins ) . in this work
, we propose a novel index called component - edge ( ce ) score to quantitatively measure the notion of complex derivability " from ppi networks . using this index ,
we theoretically categorize complexes as sparse " or
dense " with respect to a given network .
we then devise an algorithm sparc that selectively employs functional interactions to improve the ce scores of predicted complexes , and thereby elevates many of the sparse " complexes to dense " .
this empowers existing methods to detect these sparse " complexes .
we demonstrate that our approach is effective in reconstructing significantly many complexes missed previously ( 104 recovered out of the 123 known complexes or @xmath447% improvement ) .
availability : http://www.comp.nus.edu.sg/@xmath4leonghw/mcl-caw/ .
And you have already written the first three sentences of the full article: stoichiometrically stable complexes are formed by proteins that _ physically _ interact to achieve biological functions within the cell .
these complexes interact with individual proteins or other complexes to form functional modules and pathways that drive the cellular machinery .
therefore , a faithful reconstruction of the entire set of complexes is essential to not only understand complex formations , but also the higher level organization of the cell ..
Please generate the next two sentences of the article
|
recent advances in high - throughput techniques have enabled to catalogue enormous amounts of physical interaction data particularly in organisms such as _ saccharomyces cerevisiae _ ( budding yeast ) . typically these interactions are arranged in the form of a protein interaction network ( or ppi network ) and mined for complexes using computational techniques . from a topological perspective
, these complexes are typically interpreted as regions in the network where proteins are densely connected to each other than to the rest of the network @xcite .
|
12,232 |
Suppose that you have an abstract for a scientific paper: we investigate the properties of interference fragmentation functions arising from the emission of two leading hadrons inside the same jet for inclusive lepton - nucleon deep - inelastic scattering .
using an extended spectator model for the mechanism of the hadronization , we give a complete calculation and numerical estimates for the examples of a proton - pion pair produced with invariant mass on the roper resonance , and of two pions produced with invariant mass close to the @xmath0 mass .
we discuss azimuthal angular dependence of the leading order cross section to point up favourable conditions for extracting transversity from experimental data .
= cmr8 1.5pt .
And you have already written the first three sentences of the full article: because of the still lacking rigorous explanation of confinement , the nonperturbative nature of quarks and gluons inside hadrons can be explored by extracting information from distribution ( df ) and fragmentation functions ( ff ) in hard scattering processes .
there are three fundamental df that completely characterize the quark inside hadrons at leading twist with respect to its longitudinal momentum and spin : the momentum distribution @xmath1 , the helicity distribution @xmath2 and the transversity distribution @xmath3 . at variance with the first two ones
, @xmath3 is difficult to address because of its chiral - odd nature ..
Please generate the next two sentences of the article
|
a complementary information can come from the analysis of the hadrons produced by the fragmentation process of the final quark , namely from ff . so far , only the leading unpolarized ff , @xmath4 , is partly known , which is the counterpart of @xmath1 .
the basic reason for such a poor knowledge is related to the difficulty of measuring more exclusive channels in hard processes .
|
12,233 |
Suppose that you have an abstract for a scientific paper: the lulu operators , well known in the nonlinear multiresolution analysis of sequences , are extended to functions defined on continuous domain , namely , a real interval @xmath0 .
similar to their discrete counterparts , for a given @xmath1 the operators @xmath2 and @xmath3 form a fully ordered semi - group of four elements .
it is shown that the compositions @xmath4 and @xmath5 provide locally @xmath6-monotone approximations for the bounded real functions defined on @xmath7 .
the error of approximation is estimated in terms of the modulus of nonmonotonicity . .
And you have already written the first three sentences of the full article: the lulu operators remove impulsive noise before a signal extraction from a sequence .
they are computationally convenient and conceptually simpler compared to the the median smoothers usually considered to be the `` basic '' smoothers .
the lulu operators have particular properties , e.g. they are fully trend preserving , @xcite , preserve the total variation , @xcite , etc . , which make them an essential tool for multiresolution analysis of sequences ..
Please generate the next two sentences of the article
|
furthermore , it was demonstrated during the last decade or so that these operators , being specific cases of morphological filters , @xcite , have a critical role in the analysis and comparison of nonlinear smoothers , @xcite .
we extend the lulu theory from sequences to functions on a continuous domain , namely , a real interval @xmath7 .
|
12,234 |
Suppose that you have an abstract for a scientific paper: we discuss how the ideal formalism of computational mechanics can be adapted to apply to a non - infinite series of corrupted and correlated data , that is typical of most observed natural time series
. specifically , a simple filter that removes the corruption that creates rare unphysical causal states is demonstrated , and the new concept of effective soficity is introduced .
we believe that computational mechanics can not be applied to a noisy and finite data series without invoking an argument based upon effective soficity .
a related distinction between noise and randomness is also defined : noise can only be eliminated by increasing the length of the time series , whereas the resolution of random structure only requires the finite memory of the analysis to be increased .
the benefits of these new concepts are demonstrated on simulated times series by ( a ) the effective elimination of white noise corruption from a periodic signal using the expletive filter and ( b ) the appearance of an effectively sofic region in the statistical complexity of a biased poisson switch time series that is insensitive to changes in the wordlength ( memory ) used in the analysis . the new algorithm
is then applied to analysis of a real geomagnetic time series measured at halley , antarctica .
two principal components in the structure are detected that are interpreted as the diurnal variation due to the rotation of the earth - based station under an electrical current pattern that is fixed with respect to the sun - earth axis and the random occurrence of a signature likely to be that of the magnetic substorm . in conclusion ,
a hypothesis is advanced about model construction in general . .
And you have already written the first three sentences of the full article: computational mechanics ( cm ) @xcite has a formalism @xcite that has been proved to construct the minimal model capable of statistically reproducing all the resolvable causal structure of any infinite sequence of discrete measurements ( be they scalar , vector , tensor , or descriptive)@xcite .
the size of a model so defined , measured by a quantity termed statistical complexity , @xmath0 , @xcite is a reliable and falsifiable indication of the amount of structure the data contain@xcite .
the particular strengths of this approach are that it enables the complexities and structures of different sets of data to be quantifiably compared and that it directly discovers detailed causal structure within those data . by examining data in this way it is possible to appreciate , in a well - defined abstract sense , how a system actually functions and what scales are most important to it ..
Please generate the next two sentences of the article
|
this information can then be used to optimise the efficiency of physically plausible models@xcite . as with all other analytical tools , cm has some limitations in the face of certain real - world problems that affect the information content of the signal under study .
these problems may include : 1 .
|
12,235 |
Suppose that you have an abstract for a scientific paper: the w50/ss433 system is an unusual galactic outflow - driven object of debatable origin . we have used the australia telescope compact array ( atca ) to observe a new 198 pointing mosaic , covering @xmath0 , and present the highest - sensitivity full - stokes data of w50 to date using wide - field , wide - band imaging over a 2 ghz bandwidth centred at 2.1 ghz .
we also present a complementary h@xmath1 mosaic created using the isaac newton telescope photometric h@xmath1 survey of the northern galactic plane ( iphas ) .
the magnetic structure of w50 is found to be consistent with the prevailing hypothesis that the nebula is a reanimated shell - like supernova remnant ( snr ) , that has been re - energised by the jets from ss433 .
we observe strong depolarization effects that correlate with diffuse h@xmath1 emission , likely due to spatially - varying faraday rotation measure ( rm ) fluctuations of @xmath2 to 61 rad m@xmath3 on scales @xmath4 to 6 pc .
we also report the discovery of numerous , faint , h@xmath1 filaments that are unambiguously associated with the central region of w50 .
these thin filaments are suggestive of a snr s shock emission , and almost all have a radio counterpart . furthermore , an rm - gradient is detected across the central region of w50 , which we interpret as a loop magnetic field with a symmetry axis offset by @xmath590@xmath6 to the east west jet - alignment axis , and implying that the evolutionary processes of both the jets and the snr must be coupled .
a separate rm - gradient is associated with the termination shock in the eastern ear , which we interpret as a ring - like field located where the shock of the jet interacts with the circumstellar medium .
future optical observations will be able to use the new h@xmath1 filaments to probe the kinematics of the shell of w50 , potentially allowing for a definitive experiment on w50 s formation history .
= 1 [ firstpage ] magnetic fields polarization ism : bubbles ism : jets and outflows
ism :....
And you have already written the first three sentences of the full article: the large radio nebula w50 , also referred to as g39.72.0 and the `` manatee nebula '' , is both unusual and of an undetermined origin .
the nebula appears to be interacting with the central compact source and microquasar ss433 the first known stellar source of relativistic jets @xcite .
the w50/ss433 system was first identified at radio wavelengths by @xcite ..
Please generate the next two sentences of the article
|
initial suggestions for the system s origin were made by , e.g. @xcite , which identified ss433 as a new class of stellar remnant ( the first - known galactic microquasar ) and proposed that the surrounding radio nebula of w50 was the remnant from a supernova explosion .
the nebula is widely catalogued and considered as a supernova remnant ( snr ; * ? ? ?
|
12,236 |
Suppose that you have an abstract for a scientific paper: we present an overview of the full range of higgs searches in models beyond the standard model at the tevatron .
this includes both searches for fermiophobic higgs and for susy higgs at high @xmath0 .
no excess is seen in the data , so model dependent limits are set . .
And you have already written the first three sentences of the full article: most of the higgs efforts of the cdf and collaborations are centered on finding a standard model higgs boson .
however the standard model is incomplete and there are proposed extensions to the standard model , many of which feature one or more higgs bosons as well . these are often similar to the standard model higgs , but differ in their couplings to other particles . for the purposes of this presentation ,
i divide the higgs searches into two categories , fermiophobic higgs searches and susy higgs searches at high @xmath0 ..
Please generate the next two sentences of the article
|
in the fermiophobic higgs models , the higgs is assumed not to couple to fermions . at high masses
it then decays to a w pair and at low masses to a photon pair .
|
12,237 |
Suppose that you have an abstract for a scientific paper: we have derived oxygen and nitrogen abundances of a sample of late - type , low surface brightness ( lsb ) galaxies found in the sloan digital sky survey ( sdss ) .
furthermore , we have computed a large grid ( 5000 models ) of chemical evolution models ( cems ) testing various time - scales for infall , baryon densities and several power - law initial mass functions ( imfs ) as well . because of the rather stable n / o - trends found both in cems ( for a given imf ) and in observations , we find that the hypotheses that lsb galaxies have stellar populations dominated by low - mass stars , i.e. , very bottom - heavy imfs ( see lee et al .
2004 ) , can be ruled out .
such models predict much too high n / o - ratios and generally too low o / h - ratios .
we also conclude that lsb galaxies probably have the same ages as their high surface brightness counterparts , although the global rate of star formation must be considerably lower in these galaxies . .
And you have already written the first three sentences of the full article: we use the data compilation by caldwell & bergvall ( 2006 ) consisting of a sample of 1199 close to edge - on ( @xmath0 ) low surface brightness ( lsb ) galaxies in the fourth data release of the sloan digital sky survey ( sdss - dr4 ) .
all galaxies in the sample were selected in order to obtain a sample of isolated , bulge - less systems , which is ideal for comparison with simple cems since the merger histories of such galaxies have less influence on the evolution of elemental ratios .
this total sample is divided by @xmath1 colour limits into a blue sample a ( 377 galaxies ) , a green ( intermediate ) sample b ( 436 galaxies ) and a red sample c ( 386 galaxies ) . from these 1199 galaxies we pick out the ones with a relative error in the h@xmath2-flux less than @xmath3 ..
Please generate the next two sentences of the article
|
we have computed a large grid ( 5000 models ) of one - zone cems , testing time - scales for infall from @xmath4 gyr to @xmath5 gyr , baryon densities ranging between @xmath6 pc@xmath7 and @xmath8 pc@xmath7 , which should cover most of the possible variations within dwarf and late - type galaxies .
star formation is prescribed by a simple schmidt - law , @xmath9 , where the constant @xmath10 is varied between @xmath11 to @xmath12 .
|
12,238 |
Suppose that you have an abstract for a scientific paper: deeply virtual compton scattering has recently been studied by three hera experiments , h1 , zeus and hermes , covering a broad range of kinematic regimes .
we present cross section measurements of the two collider experiments in the kinematic region 2@xmath0@xmath1@xmath0100 gev@xmath2 and 30@xmath0@xmath3@xmath0140 gev , and compare them to qcd - based calculations .
hermes measurements of azimuthal asymmetries and their kinematical dependences are presented for @xmath1@xmath41 gev@xmath2 and 2@xmath0@xmath3@xmath07 gev . .
And you have already written the first three sentences of the full article: the internal structure of the nucleon has long been studied with inclusive deep - inelastic lepton scattering . from these studies , the spin - dependent and spin - independent nucleon structure functions and corresponding parton distribution functions
have been extracted .
recently , the formalism of generalized parton distributions ( gpd ) @xcite-@xcite was introduced . in this framework ,.
Please generate the next two sentences of the article
|
non - forward degrees of freedom are probed in exclusive processes such as meson production or deeply virtual compton scattering ( dvcs ) , the electroproduction of a single real photon on the nucleon , which has been studied at desy @xcite-@xcite and jefferson lab @xcite .
this opens the way to access the distribution of partons in the nucleon perpendicular to its momentum @xcite , and to access the contribution of the orbital angular momenta of the quarks to the nucleon spin @xcite .
|
12,239 |
Suppose that you have an abstract for a scientific paper: the properties of few - body clusters ( mass number @xmath0 ) are modified if they are immersed in a nuclear medium .
in particular , pauli blocking that reflects the antisymmetrization of the many - body wave function is responsible for the medium modification of light clusters and the dissolution with increasing density . a more consistent description is given with takes also the contribution of correlations in the continuum into account .
the relation between cluster formation in warm dense matter and in nuclear structure is discussed . .
And you have already written the first three sentences of the full article: we consider the propagation of @xmath1 nucleons [ @xmath2 neutrons ( @xmath3 ) and @xmath4 protons ( @xmath5 ) ] in a nuclear medium described by the particle densities @xmath6 and @xmath7 as well as the temperature @xmath8 .
using a thermodynamic green function approach , the following in - medium wave equation can be derived ( see @xcite ) @xmath9\psi_{a \nu p}(1\dots a ) \nonumber \\ & & + \sum_{1'\dots a'}\sum_{i < j}[1- f(i)- f(j)]v(ij , i'j')\prod_{k \neq i , j } \delta_{kk'}\psi_{a \nu p}(1'\dots a')=0\ , . \label{wavea}\end{aligned}\ ] ] this equation contains the effects of the medium in the quasiparticle shift @xmath10 as well as in the pauli blocking terms @xmath11 $ ] .
the single - nucleon state @xmath12 is abbreviated by @xmath13 etc ..
Please generate the next two sentences of the article
|
the single - nucleon quasiparticle shift @xmath14 is obtained from the single - nucleon self - energy which can be taken , for instance , in mean - field approximation .
standard expressions give a rigid shift in the energy and , if the momentum dependence is taken into account , the replacement of the nucleon mass @xmath15 by an effective mass .
|
12,240 |
Suppose that you have an abstract for a scientific paper: the mass term for majorana neutrinos explicitly violates lepton number .
several authors have used this fact to create a lepton asymmetry in the universe by considering cp violating effects in the one loop self - energy correction for the decaying heavy majorana neutrino .
we compare and comment on the different approaches used to calculate the lepton asymmetry including those using an effective hamiltonian and resummed propagators .
we also recalculate the asymmetry in the small mass difference limit . plus 1pt
@=12 -0.5 in 0.0 in 0.0 in 8.5 in 6.5 in [ 1 ] # 10= 0=0 1= 1=1 0>1 # 1 / 12h_12 12 t august 1999 + hep - ph/9908417 * leptogenesis with heavy majorana neutrinos reexamined + * * e - mail : [email protected] @xmath0 e - mail : [email protected] after sakharov s seminal paper on the conditions for obtaining a matter asymmetric universe several authors have attempted to realise these conditions in the context of different models@xcite .
one approach is to create a lepton asymmetric universe by the asymmetric decay of heavy scalars or majorana neutrinos and to convert the lepton asymmetry into a baryon asymmetry by b+l violating sphaleron processes . in the original papers on leptogenesis cp violation
was realised by the interference between the tree level diagram and the one loop vertex correction@xcite .
later it was realised that there was an additional contribution from the one loop self - energy correction to the external heavy scalar or neutrino@xcite .
the self - energy contribution has been calculated differently by different authors .
refs.@xcite obtain the asymmetry by considering the interference of the tree level diagram for decay and the diagram containing the one loop self - energy correction .
however this approach breaks down in the degenerate heavy particle mass limit . in refs.@xcite
the authors obtain the one loop effective hamiltonian , or more precisely , the one loop effective mass matrix for the heavy species . because particles in....
And you have already written the first three sentences of the full article: let us start with the lagrangian @xmath2 \nonumber \\ & & + \sum_{\alpha , i } \
, h^\ast_{\alpha i } \ , \overline{n_{ri } } \ , \phi^{\dagger } \ , \ell_{l}^{\alpha } + \sum_{\alpha , i } h_{\alpha i } \ , \overline{\ell_{l}^{\alpha } } \phi \ , n_{ri } \label{eq : lag}\\ & & + \sum_{\alpha , i } \ , h^\ast_{\alpha i } \ , \overline{(\ell_{l } ^{\alpha}})^c \ , \phi^\dagger \ , ( n_{ri})^c + \sum_{\alpha , i } h_{\alpha i } \overline{(n_{ri})^c } \ , \phi \ , ( \ell_{l}^{\alpha})^c \nonumber \ ] ] as in ref.@xcite .
@xmath3 and @xmath4 ..
Please generate the next two sentences of the article
|
@xmath5 are light leptons and @xmath6 is a scalar field . for concreteness the @xmath5 can be the left - handed lepton doublet of the standard model , @xmath6 can be the standard model higgs doublet .
we supress the su(2 ) indices carried by the lepton and the higgs fields which are contracted by the @xmath7 tensor . @xmath8 and @xmath9 are generation indices and we assume one heavy majorana field per generation of light leptons .
|
12,241 |
Suppose that you have an abstract for a scientific paper: the main purpose of this paper is to introduce first a new family of empirical test statistics for testing a simple null hypothesis when the vector of parameters of interest are defined through a specific set of unbiased estimating functions .
this family of test statistics is based on a distance between two probability vectors , with the first probability vector obtained by maximizing the empirical likelihood on the vector of parameters , and the second vector defined from the fixed vector of parameters under the simple null hypothesis .
the distance considered for this purpose is the phi - divergence measure .
the asymptotic distribution is then derived for this family of test statistics . the proposed methodology is illustrated through the well - known data of newcomb s measurements on the passage time for light .
a simulation study is carried out to compare its performance with respect to the empirical likelihood ratio test when confidence intervals are constructed based on the respective statistics for small sample sizes .
the results suggest that the empirical modified likelihood ratio test statistic provides a competitive alternative to the empirical likelihood ratio test statistic , and is also more robust than the empirical likelihood ratio test statistic in the presence of contamination in the data .
finally , we propose empirical phi - divergence test statistics for testing a composite null hypothesis and present some asymptotic as well as simulation results to study the performance of these test procedures .
= 1 * :* 62e20 * :* empirical likelihood , empirical phi - divergence test statistics , influence function , phi - divergence measures , power function , empirical likelihood ratio , empirical modified likelihood ratio . .
And you have already written the first three sentences of the full article: empirical likelihood ( el ) is a powerful and currently widely used approach for developing efficient nonparametric statistics .
the el was introduced by owen ( 1988 ) and since then many papers have appeared on this topic making varied contributions to different inferential problems . in this approach , the parameters are usually defined as functionals of the unknown population distribution . the first purpose of this paper is to introduce a new family of empirical test statistics as an alternative to the likelihood ratio test statistic proposed by qin and lawless ( 1994 ) for testing a simple null hypothesis . as an extension of the empirical likelihood ratio test of qin and lawless ( 1995 ) , a new family of empirical test statistics
is also considered here for composite hypothsis ..
Please generate the next two sentences of the article
|
this new family of empirical test statistics is based on divergence measures .
consider @xmath0-variate i.i.d .
|
12,242 |
Suppose that you have an abstract for a scientific paper: this paper develops a control and estimation design for the one - phase stefan problem .
the stefan problem represents a liquid - solid phase transition as time evolution of a temperature profile in a liquid - solid material and its moving interface .
this physical process is mathematically formulated as a diffusion partial differential equation ( pde ) evolving on a time - varying spatial domain described by an ordinary differential equation ( ode ) .
the state - dependency of the moving interface makes the coupled pde - ode system a nonlinear and challenging problem .
we propose a full - state feedback control law , an observer design , and the associated output - feedback control law via the backstepping method .
the designed observer allows estimation of the temperature profile based on the available measurement of solid phase length .
the associated output - feedback controller ensures the global exponential stability of the estimation errors , the @xmath0-norm of the distributed temperature , and the moving interface to the desired setpoint under some explicitly given restrictions on the setpoint and observer gain .
the exponential stability results are established considering neumann and dirichlet boundary actuations .
stefan problem , backstepping , distributed parameter systems , moving boundary , nonlinear stabilization . .
And you have already written the first three sentences of the full article: [ [ background ] ] background + + + + + + + + + + problem , known as a thermodynamical model of liquid - solid phase transition , has been widely studied since jeseph stefan s work in 1889@xcite .
typical applications include sea ice melting and freezing @xcite , continuous casting of steel @xcite , crystal - growth @xcite , thermal energy storage system @xcite , and lithium - ion batteries @xcite .
for instance , time evolution of the arctic sea ice thickness and temperature profile was modeled in @xcite using the stefan problem , and the correspondence with the empirical data was investigated ..
Please generate the next two sentences of the article
|
apart from the thermodynamical model , the stefan problem has been employed to model a type of population growth , such as in @xcite for tumor growth process and in @xcite for information diffusion on social networks .
while phase change phenomena described by the stefan condition appear in various kinds of science and engineering processes , their mathematical analysis remains quite challenging due to the implicitly given moving interface that reflects the time evolution of a spatial domain , so - called free boundary problem " @xcite .
|
12,243 |
Suppose that you have an abstract for a scientific paper: twenty multiple stellar systems with solar - type primaries were observed at high angular resolution using the palm-3000 adaptive optics system at the 5 m hale telescope . the goal was to complement the knowledge of hierarchical multiplicity in the solar neighborhood by confirming recent discoveries by the visible robo - ao system with new near - infrared observations with palm-3000 . the physical status of most , but not all , of the new pairs is confirmed by photometry in the @xmath0 band and new positional measurements . in addition , we resolved for the first time five close sub - systems : the known astrometric binary in hip 17129ab , companions to the primaries of hip 33555 , and hip 118213 , and the companions to the secondaries in hip 25300 and hip 101430 .
we place the components on a color - magnitude diagram and discuss each multiple system individually
. = @xmath1 @xmath2 .
And you have already written the first three sentences of the full article: statistics of binaries and hierarchical stellar systems trace conditions of star formation and serve as an excellent diagnostic for testing theoretical predictions and numerical simulations .
only recently have observational techniques such as adaptive optics ( ao ) and radial velocities ( rv ) reached the maturity and productivity needed for a high quality binary census over a wide range of periods .
the latest results on binary statistics are reviewed by @xcite ..
Please generate the next two sentences of the article
|
reaching completeness for triple and higher - order hierarchies is even more challenging .
the fraction of known hierarchical systems in the nearby 25-pc volume has doubled recently @xcite in comparison with the earlier work by @xcite .
|
12,244 |
Suppose that you have an abstract for a scientific paper: let @xmath0 be a knot of genus @xmath1 .
if @xmath0 is fibered , then it is well known that the knot group @xmath2 splits only over a free group of rank @xmath3 .
we show that if @xmath0 is not fibered , then @xmath2 splits over non - free groups of arbitrarily large rank . furthermore ,
if @xmath0 is not fibered , then @xmath2 splits over every free group of rank at least @xmath3 .
however , @xmath2 can not split over a group of rank less than @xmath3 .
the last statement is proved using the recent results of agol , przytycki wise and wise . .
And you have already written the first three sentences of the full article: we start out with a few definitions from group theory .
let @xmath4 be a group .
we say that _ @xmath4 splits over the subgroup @xmath5 _ if @xmath4 admits an hnn decomposition with base group @xmath6 and amalgamating subgroup @xmath5 ..
Please generate the next two sentences of the article
|
more precisely , @xmath4 splits over the subgroup @xmath5 if there exists an isomorphism @xmath7 where @xmath8 are subgroups of @xmath4 and @xmath9 is a monomorphism . in this notation ,
relations of @xmath6 are implicit .
|
12,245 |
Suppose that you have an abstract for a scientific paper: we present the results of 45 transit observations obtained for the transiting exoplanet hat - p-32b .
the transits have been observed using several telescopes mainly throughout the yeti network . in 25 cases , complete
transit light curves with a timing precision better than @xmath0min have been obtained .
these light curves have been used to refine the system properties , namely inclination @xmath1 , planet - to - star radius ratio @xmath2 , and the ratio between the semimajor axis and the stellar radius @xmath3 .
first analyses by @xcite suggest the existence of a second planet in the system , thus we tried to find an additional body using the transit timing variation ( ttv ) technique .
taking also literature data points into account , we can explain all mid - transit times by refining the linear ephemeris by @xmath4ms .
thus we can exclude ttv amplitudes of more than @xmath5min .
[ firstpage ] stars : individual : hat - p-32 planets and satellites : individual : hat - p-32b planetary systems .
And you have already written the first three sentences of the full article: since the first results of the _ kepler _ mission were published , the number of known planet candidates has enlarged tremendously .
most _ hot jupiters _ have been found in single planetary systems and it was believed that those kind of giant , close - in planets are not accompanied by other planets ( see e.g. * ? ? ?
this result has been obtained analysing 63 _ kepler _ hot jupiter candidates and is in good agreement with inward migration theories of massive outer planets , and planet planet scattering that could explain the lack of additional close planets in hot jupiter systems ..
Please generate the next two sentences of the article
|
nonetheless , wide companions to hot jupiters have been found , as shown e.g. in @xcite for the hat - p-13 system .
one has to state , though , that the formation of hot jupiters is not yet fully understood ( see @xcite and references therein for some formation scenarios , and e.g. @xcite for possible tests ) .
|
12,246 |
Suppose that you have an abstract for a scientific paper: osiris is a day one instrument that will be available at the 10 m gtc telescope which is being built at la palma observatory in the canary islands .
this optical instrument is designed to obtain wide - field narrow - band images using tunable filters and to do low - resolution spectroscopy in both long - slit and multislit modes . for the multislit spectroscopy mode ,
we have developed a software to assist the observers to design focal plane masks . in this paper
we describe the characteristics of this mask designer tool .
we discuss the main design concepts , the functionality and particular features of the software . .
And you have already written the first three sentences of the full article: osiris ( optical system for imaging and low / intermediate - resolution integrated spectroscopy ) is an instrument designed to obtain images and low - resolution spectra in the optical domain ( from 3650 through 10,000 ) .
it will be installed at the nasmyth focus of the 10 m gtc telescope @xcite at la palma observatory , although it can be also mounted at the cassegrain focus .
a detailed account of the observing modes , optical design , and performance is given in @xcite ..
Please generate the next two sentences of the article
|
osiris is a versatile instrument offering many observing modes : ( a ) direct imaging with broad - band and narrow - band using tunable filters , ( b ) narrow - band with charge shuffling , ( c ) fast photometry , ( d ) long - slit spectroscopy , ( e ) multi - object spectroscopy , ( f ) nod - and - shuffle multi - object spectroscopy , and ( g ) fast spectroscopy .
the main driver of the optical and mechanical design of osiris has been the inclusion of tunable filters ( tf ) in order to obtain narrow - band imaging at an arbitrary wavelength with effective resolutions of around 5 - 60 . in the spectroscopic modes
|
12,247 |
Suppose that you have an abstract for a scientific paper: we systematically analyze the broadband ( 0.5200 kev ) x - ray spectra of hard x - ray ( @xmath0 kev ) selected local low - luminosity active galactic nuclei ( llagns ) observed with _
suzaku _ and _ swift_/bat .
the sample consists of ten llagns detected with _
swift_/bat with intrinsic 14195 kev luminosities smaller than @xmath1 erg s@xmath2 available in the _ suzaku _ archive , covering a wide range of the eddington ratio from @xmath3 to @xmath4 .
the overall spectra can be reproduced with an absorbed cut - off power law , often accompanied by reflection components from distant cold matter , and/or optically - thin thermal emission from the host galaxy . in all objects ,
relativistic reflection components from the innermost disk are not required .
eight objects show a significant narrow iron - k@xmath5 emission line . comparing their observed equivalent widths with the predictions from the monte - carlo based torus model by @xcite , we constrain the column density in the equatorial plane to be @xmath6 or the torus half opening angle @xmath7 .
we infer that the eddington ratio ( @xmath8 ) is a key parameter that determines the torus structure of llagns : the torus becomes large at @xmath9 , whereas at lower accretion rates it is little developed .
the luminosity correlation between the hard x - ray and mid - infrared ( mir ) bands of the llagns follows the same one as for more luminous agns .
this implies that other mechanisms than agn - heated dust are responsible for the mir emission in low eddington ratio llagns . .
And you have already written the first three sentences of the full article: active galactic nuclei ( agns ) emit intense x - ray radiation by converting the gravitational energy of matter accreted onto the supermassive black holes ( smbhs ) . according to the so - called agn unified model @xcite , the central engine is obscured by a dusty torus , which affects the observed x - ray spectrum via photoelectric absorption and compton reflection . in addition , a relativistically blurred reflection component from the innermost accretion disk
would be expected when the disk is extended down to a vicinity of the smbh .
hence , observations of broadband x - ray spectra of agns are useful to investigate their structure including the torus and accretion disk ..
Please generate the next two sentences of the article
|
low - luminosity agns ( llagns ) , which we define by their low x - ray luminosities in the 14195 kev band ( @xmath10 erg s@xmath2 ) , are important objects to understand the evolution of agns .
llagns contain two extreme types of agns : those with a small smbh mass and a high mass - accretion rate ( i.e. , with a high eddington ratio ) , and those with a large smbh mass and a low mass - accretion rate ( a low eddington ratio ) .
|
12,248 |
Suppose that you have an abstract for a scientific paper: during the last few years deep underwater neutrino telescopes of a new generation with dimensions close to 100 m or more were taken into operation .
for the correct track reconstruction of events and for the interpretation of light pulses from calibration lasers one has to use the group velocity for light signals . the difference between group velocity and the traditionally used phase velocity leads to an additional delay of about 10 ns for a distance of 100 m between light source and photomultiplier . from the time of the appearance of the first projects of deep underwater neutrino telescopes in the middle of 70th
this fact was never mentioned in the literature . on the velocity of light signals in the deep underwater neutrino experiments l.a.kuzmichev + skobeltsyn institute of nuclear physics , moscow state university + 119899 , moscow , russia , e - mail : [email protected] [ [ section ] ] during the last few years the new large - scale neutrino telescopes nt-200 /1/ and +
have been taken into operation .
two deep underwater arrays , and antares /4/ , are under construction .
the cherenkov light from high energy muons , electromagnetic and hadronic showers can be recorded at distances of 20 100 m depending upon the light absorption of water or ice .
impulse laser light sources are widely used in these arrays for calibration .
light pulses from such sources can be recorded over even larger distances . at such distances ,
the difference between group and phase velocity of light in water or ice is essential .
as far as i know , this fact hasnt been mentioned in the literature from the time of the first neutrino telescope projects in the middle of the seventies /5,6/ and hasnt been taken into account for the data analysis and mc calculations .
the velocity of light pulses in matter is given by the group velocity /7,8/ : @xmath0 where @xmath1 is the frequency , @xmath2 is the wave vector .
the connection between @xmath1 and @xmath2 can be written in the....
And you have already written the first three sentences of the full article: i would like to express thanks to g.v.domogatsky , j - a.m .
djilkibaev , s.i.klimushin , b.k.lubsandorzhiev , e.a.osipova , v.v.prosin , c.spiering and v.b.tsvetkov for useful discussion .
i.a.belolaptikov et al ..
Please generate the next two sentences of the article
|
, + the baikal underwater neutrino telescope : design , performance , and first results .
+ astroparticle physics 7(1997 ) 263 - 282 .
|
12,249 |
Suppose that you have an abstract for a scientific paper: high - entropy alloys are made from random mixtures of principal elements on simple lattices , stabilized by a high mixing entropy .
the recently discovered bcc ta - nb - hf - zr - ti high entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials , e.g. it has a well defined superconducting transition along with an exceptional robustness against disorder .
here we show that the valence - electron count dependence of the superconducting transition temperature in the high entropy alloy falls between those of analogous simple solid solutions and amorphous materials , and test the effect of alloy complexity on the superconductivity .
we propose high - entropy alloys as excellent intermediate systems for studying superconductivity as it evolves between crystalline and amorphous materials . .
And you have already written the first three sentences of the full article: alloys are among the most relevant materials for modern technologies .
conventional alloys typically consist of one principal element , such as the iron in steel , plus one or more dopant elements in small proportion ( e.g. carbon in the case of steel ) that enhance a certain property of interest ; the properties are based on the modification of those of the principal element . in sharp contrast , high - entropy alloys ( hea ) are comprised of multiple principal elements that are all present in major proportion , with the simple structures observed attributed to the high configurational entropy of the random mixing of the elements on their lattice sites @xcite .
thus , the concept of a `` principal element '' becomes irrelevant ..
Please generate the next two sentences of the article
|
the elements in heas arrange on simple lattices with the atoms stochastically distributed on the crystallographic positions ; heas are commonly referred to as metallic glasses on an ordered lattice ( see figure [ fig:1](a ) and ( b ) ) .
the properties of heas arise as a result of the collective interactions of the randomly distributed constituents @xcite .
|
12,250 |
Suppose that you have an abstract for a scientific paper: it has been shown that the behaviour of primordial gas collapsing in a dark matter minihalo can depend on the adopted choice of 3-body h@xmath0 formation rate . the uncertainties in this rate span two orders of magnitude in the current literature , and
so it remains a source of uncertainty in our knowledge of population iii star formation .
here we investigate how the amount of fragmentation in primordial gas depends on the adopted 3-body rate .
we present the results of calculations that follow the chemical and thermal evolution of primordial gas as it collapses in two dark matter minihalos .
our results on the effect of 3-body rate on the evolution until the first protostar forms agree well with previous studies .
however , our modified version of gadget-2 sph also includes sink particles , which allows us to follow the initial evolution of the accretion disc that builds up on the centre of each halo , and capture the fragmentation in gas as well as its dependence on the adopted 3-body h@xmath0 formation rate .
we find that the fragmentation behaviour of the gas is only marginally effected by the choice of 3-body rate co - efficient , and that halo - to - halo differences are of equal importance in affecting the final mass distribution of stars .
[ firstpage ] stars : formation stars : early universe hydrodynamics
instabilities .
And you have already written the first three sentences of the full article: according to the standard model of the primordial star formation process , the very first stars , the so - called population iii ( or pop .
iii ) stars form within dark matter ( dm ) halos with virial temperature @xmath1 k and masses @xmath2 @xmath3 that collapsed at redshift @xmath4 25 - 30 or above ( @xcite ) .
the hydrogen atoms in the dm halos combine with the small abundances of free electrons via @xmath5 , followed by @xmath6 , where the free electrons act as catalysts and are present as residue from the epoch of recombination at @xmath4 1100 ( @xcite ) ..
Please generate the next two sentences of the article
|
the typical fractional abundances of h@xmath0 of @xmath7 are sufficient to permit the primordial gas in the minihalos to cool as it collapses ( see , e.g. @xcite ) via h@xmath0 rotational and vibrational line emission .
this occurs until the gas reaches a temperature @xmath8 200k @xcite at a density of @xmath9@xmath10 , at which point the h@xmath0 energy levels move into the local thermodynamical equilibrium ( lte ) with the kinetic temperature of the gas , and the resulting cooling time becomes longer than the free - fall of the gas .
|
12,251 |
Suppose that you have an abstract for a scientific paper: we consider the problem of multiple descriptions ( md ) source coding and propose new coding strategies involving both unstructured and structured coding layers .
previously , the most general achievable rate - distortion ( rd ) region for the @xmath0-descriptions problem was the combinatorial message sharing with binning ( cmsb ) region .
the cmsb scheme utilizes unstructured quantizers and unstructured binning . in the first part of the paper , we show that this strategy can be improved upon using more general unstructured quantizers and a more general unstructured binning method . in the second part , structured coding strategies are considered .
first , structured coding strategies are developed by considering specific md examples involving three or more descriptions .
we show that application of structured quantizers results in strict rd improvements when there are more than two descriptions .
furthermore , we show that structured binning also yields improvements . these improvements are in addition to the ones derived in the first part of the paper .
this suggests that structured coding is essential when coding over more than two descriptions . using the ideas developed through these examples we provide a new unified coding strategy by considering several structured coding layers .
finally , we characterize its performance in the form of an inner bound to the optimal rate - distortion region using computable single - letter information quantities .
the new rd region strictly contains all of the previous known achievable regions . .
And you have already written the first three sentences of the full article: the multiple - descriptions ( md ) source coding problem arises naturally in a number of applications such as transmission of video , audio and speech over packet networks and fading channels @xcite@xcite .
the multiple - descriptions ( md ) source coding setup describes a communications setting consisting of one encoder and several decoders .
the encoder receives a discrete memoryless source and wishes to compress it into several _.
Please generate the next two sentences of the article
|
descriptions_. each decoder receives a specific subset of these descriptions through noiseless links , and produces a reconstruction of the source vector with respect to its own distortion criterion .
the parameters of interest are the rates required for transmitting the description and the resulting distortions at the decoders .
|
12,252 |
Suppose that you have an abstract for a scientific paper: we investigate electron - positron pair creation from the vacuum in a pulsed electric background field . employing the sauter - type pulsed field @xmath0 with height @xmath1 and width @xmath2 , we demonstrate explicitly the interplay between the nonperturbative and perturbative aspects of pair creation in the background field .
we analytically compute the number of produced pairs from the vacuum in the sauter - type field , and the result reproduces schwinger s nonperturbative formula in the long pulse limit ( the constant field limit ) , while in the short pulse limit it coincides with the leading - order perturbative result .
we show that two dimensionless parameters @xmath3 and @xmath4 characterize the importance of multiple interactions with the fields and the transition from the perturbative to the nonperturbative regime .
we also find that pair creation is enhanced compared to schwinger s formula when the field strength is relativity weak @xmath5 and the pulse duration is relatively short @xmath6 , and reveal that the enhancement is predominantly described by the lowest order perturbation with a single photon .
ut - komaba/14 - 1 kek - th-1737 * finite pulse effects on @xmath7 pair creation from strong electric fields * h. taya@xmath8 , h. fujii@xmath9 , and k. itakura@xmath10 + @xmath9 _ institute of physics , university of tokyo , komaba 3 - 8 - 1 , tokyo 153 - 8902 , japan _
+ @xmath11 _ department of physics , the university of tokyo , hongo 7 - 3 - 1 , bunkyo - ku , tokyo 113 - 0033 , japan _
+ @xmath12 _ theory center , ipns , high energy accelerator research organization ( kek ) , tsukuba , oho 1 - 1 , ibaraki 305 - 0801 , japan
_ + @xmath13 _ department of particle and nuclear studies , graduate university for advanced studies ( sokendai ) , oho 1 - 1 , tsukuba , ibaraki 305 - 0801 , japan _ .
And you have already written the first three sentences of the full article: in the presence of extraordinarily strong gauge fields , we encounter essentially new phenomena that are not observed in the vacuum .
such phenomena are collectively called strong - field physics , " which has been attracting the attention of many researchers in various fields in physics @xcite .
there are intense laser facilities planned around the world ; in addition , compact stars and relativistic nucleus - nucleus collisions offer unique opportunities to study the strong - field phenomena . even for a system with a small coupling constant ,.
Please generate the next two sentences of the article
|
the physics becomes nonperturbative because the smallness of the coupling constant is compensated by the strong background field strength , which requires some sort of resummations of higher - order contributions .
such nonperturbative nature of interactions between particles and fields is one of the outstanding properties of strong - field physics . at the same time
|
12,253 |
Suppose that you have an abstract for a scientific paper: an analysis of the recent results from several experimental groups reported observation of a new @xmath0 baryon has been presented from a view point of the unified picture for hadron spectra developed early @xcite .
it is shown that , in fact , two different @xmath0 baryons have been discovered .
we have also established that both @xmath0 baryons are excellently incorporated in the unified picture for hadron spectra . it is argued that the presented experimental material revealed an existence of the positive srangeness @xmath0 partners for the observed @xmath1 and @xmath2 states with negative strangeness as we predicted .
* what can we learn about @xmath0 baryon + from unified picture for hadron spectra ?
* + a.a .
arkhipov + _ state research center institute for high energy physics " + 142281 protvino , moscow region , russia _ + .
And you have already written the first three sentences of the full article: the first experimental observation of a new , manifestly exotic baryon ( b=1 , s=1 , originally called the @xmath3 but now denoted as the @xmath4 ) has been reported by leps collaboration @xcite . the experiment was carried out at the laser - electron photon facility at spring-8 in japan .
a sharp baryon resonance peak for the strangeness quantum number s=+1 was found at @xmath5 gev in the @xmath6 missing mass spectrum of the @xmath7 reaction on @xmath8 .
the width of the resonance was estimated to be smaller than 25 mev and gaussian significance of the peak was 4.6 @xmath9 ..
Please generate the next two sentences of the article
|
soon after the confirmation of this observation was received by several experimental groups @xcite from different experiments where sharp peaks were observed in the @xmath10 and @xmath11 invariant mass spectra at the mass near 1540 mev . as a rule , in all experiments
a width was limited by the experimental resolution .
|
12,254 |
Suppose that you have an abstract for a scientific paper: although the lcls photon beam is meant for a single user , the baseline undulator is long enough to serve two users simultaneously . to this end
, we propose a setup composed of two simple elements : an x - ray mirrors pair for x - ray beam deflection , and a short ( @xmath0m - long ) magnetic chicane , which creates an offset for mirrors pair installation in the middle of the baseline undulator .
the insertable mirrors pair can be used for spatial separation of the x - ray beams generated in the first and in the second half of the baseline undulator .
the method of deactivating one half and activating another half of the undulator is based on the rapid switching of the fel amplification process . as proposed elsewhere , using a kicker installed upstream of the lcls baseline undulator and an already existing corrector in the first half of the undulator , it is possible to rapidly switch the x - ray beam from one user to another , thus providing two active beamlines at any time .
we present simulation results dealing with the lcls baseline , and show that it is possible to generate two saturated sase x - ray beams in the whole 0.8 - 8 kev photon energy range in the same baseline undulator .
these can be exploited to serve two users .
implementation of the proposed technique does not perturb the baseline mode of operation of the lcls undulator .
moreover , the magnetic chicane setup is very flexible , and can be used as a self - seeding setup too .
we present simulation results for the lcls baseline undulator with shab ( second harmonic afterburner ) and show that one can produce monochromatic radiation at the 2nd harmonic as well as at the 1st .
we describe an efficient way for obtaining multi - user operation at the lcls hard x - ray fel . to this end
, a photon beam distribution system based on the use of crystals in the bragg reflection geometry is proposed .
the reflectivity of crystal deflectors can be switched fast enough by flipping the crystals with piezoelectric devices similar....
And you have already written the first three sentences of the full article: the success of lcls @xcite motivated the planning of further development . according to this planning
, the two new undulators will be installed in a new undulator tunnel , and their radiation be directed to novel underground experimental halls .
the lcls baseline undulator will remain operative at least during the next decade @xcite . as a result.
Please generate the next two sentences of the article
|
, enhancing the operating lcls baseline capability becomes a challenging problem , subject to many constraints including low cost , little available time to perform changes ( and to be subtracted from operations ) and almost no risk i.e. guarantee of safe return to the baseline mode of operation . in a previous paper of us
@xcite we began to analyze possibilities for enhancing the lcls baseline subject to the above constraints .
|
12,255 |
Suppose that you have an abstract for a scientific paper: this fluid dynamics video shows the breakup of a droplet in a stationary homogeneous and isotropic turbulent flow .
we consider droplets with the same density of the transporting fluid .
the droplets and the fluid are numerically modelled by means of a multicomponent lattice - boltzmann method .
the turbulent fluid is maintained through a large scale stirring force and the radius of stable droplets , for the parameters in our simulation , is larger than the kolmogorov scale .
events of droplet deformation , break - up and aggregation are clearly visible from the movie . with the present database droplet evolution
can be studied from both an eulerian and lagrangian point of view .
the kolmogorov - hinze criteria for droplets break - up can be tested also by means of simulations with different viscosity contrast between the two components . .
And you have already written the first three sentences of the full article: droplet emulsions are key to many natural and industrial processes . in presence of an external flow ,
droplets undergo deformation , breakup , and coagulation . in a turbulent flow ,
breakup of droplets larger than the kolmogorov scale is governed by the interplay between surface tension and turbulent pressure fluctuations ..
Please generate the next two sentences of the article
|
balancing surface tension and pressure fluctuations allows to estimate the minimum unstable droplet diameter that can undergoes breakup @xcite .
turbulent pressure - driven and surface - tension stresses across a droplet of typical diameter @xmath0 and with surface tension @xmath1 can be estimated as : the initially spherical droplet ( left panel ) get strechted ( central panel ) by switching on the stirring force and generation of a turbulent flow .
|
12,256 |
Suppose that you have an abstract for a scientific paper: we investigate different methods to incorporate the effect of photons in hard processes .
we compare two different approaches used for calculating cross sections for two - photon @xmath0 process . in one of the approaches photon
is treated as a collinear parton in the proton . in the second approach
recently proposed a @xmath1-factorization method is used .
we discuss how results of the collinear parton model depend on the initial condition for the qcd evolution and discuss an approximate treatment where photon is excluded from the combined qcd - qed evolution .
we demonstrate that it is not necessary to put photon into the evolution equation as often done recently but it is sufficient to use a simplified approach in which photon couples to quarks and antiquarks which by themselves undergo dglap evolution equations .
we discuss sensitivity of the results to the choice of structure function parametrization and experimental cuts in the @xmath1-factorization approach . a new optimal structure function parametrization is proposed .
we compare results of our calculations with recent experimental data for dilepton production and find that in most cases the contribution of the photon - photon mechanism is rather small .
we discuss how to enhance the photon - photon contribution .
we also compare our results to those of recent measurements of exclusive and semi - exclusive @xmath2 pair production with certain experimental data by the cms collaboration . .
And you have already written the first three sentences of the full article: the two - photon processes may lead to production of two charged leptons and therefore compete with other sources of dileptons , such as continuum drell - yan processes or resonant production of vector quarkonia or @xmath3 boson , which produce dilepton pairs of large invariant masses .
earlier studies of lepton pair production via @xmath4 fusion in inelastic proton - proton collisions can be found in @xcite . for a general review of the @xmath5-fusion mechanism ,
see @xcite ..
Please generate the next two sentences of the article
|
inelastic processes are also included in the monte - carlo generator lpair based on @xcite
. at high energies and small dilepton transverse momenta also semi - leptonic decays of pair - wise produced charmed @xmath6 mesons may be an important ingredient of dileptons @xcite .
|
12,257 |
Suppose that you have an abstract for a scientific paper: we derive an analytical expression which allows efficient computation of the effect of all the fermi surface trajectories induced by a combination of bragg scattering and magnetic breakdown on the in - plane components of the resistivity tensor .
the particular network of coupled orbits which we consider was first formulated by falicov and sievert , who studied the problem numerically .
our approach , based upon a method used previously to derive an analytical solution for interlayer transport , allows us to show that the conductivity tensor can be written as a sum of a matrix representing the effect of total magnetic breakdown and one representing a combination of complex electronic trajectories , and we find a compact expression for the in - plane components of the resistivity tensor that can be evaluated straightforwardly . .
And you have already written the first three sentences of the full article: magnetoresistance has long been used as a tool to study the fermi surface of metals @xcite .
the observation of quantum oscillations provides a measure of the cross - sectional area of closed pockets ( due to the quantization of the landau levels ) .
the background magnetoresistance also contains information about all the electronic orbits induced by the magnetic field ..
Please generate the next two sentences of the article
|
for example , a transverse magnetoresistance saturating in high field can be evidence for the presence of closed orbits , while a magnetoresistance that increases quadratically with field can indicate open orbits .
a number of effects can complicate this picture and one such is magnetic breakdown , a concept first introduced to explain a giant orbit observed in magnesium @xcite . because of the periodic potential in a crystal , small gaps in the dispersion sometimes open up at the brillouin zone edge , splitting the fermi surface into distinct sections . in low magnetic fields ,
|
12,258 |
Suppose that you have an abstract for a scientific paper: certain thermal non - equilibrium situations , outside of the astrophysical realm , suggest that entropy production extrema , instead of entropy extrema , are related to stationary states . in an effort to better understand the evolution of collisionless self - gravitating systems
, we investigate the role of entropy production and develop expressions for the entropy production rate in two particular statistical families that describe self - gravitating systems . from these entropy production descriptions ,
we derive the requirements for extremizing the entropy production rate in terms of specific forms for the relaxation function in the boltzmann equation .
we discuss some implications of these relaxation functions and point to future work that will further test this novel thermodynamic viewpoint of collisionless relaxation . .
And you have already written the first three sentences of the full article: galaxy - hosting dark matter systems and the galactic stellar systems themselves act collisionlessly over hubble timescales . understanding the evolution of self - gravitating , collisionless systems is a foundational element to the larger picture of galaxy evolution .
much of the advancement in understanding collisionless evolution has come from @xmath0-body simulations that focus on the motions of large numbers of individual mass elements .
such simulations allow astrophysicists to determine the density and velocity distributions that result from a variety of initial conditions ( _ e.g. , _ * ? ? ?.
Please generate the next two sentences of the article
|
* ; * ? ? ?
* ; * ? ? ?
|
12,259 |
Suppose that you have an abstract for a scientific paper: in the recent work of s. sharma _
et al . _
, ( arxiv.org : cond - matt/0912.1118 ) , a single - electron spectrum associated with the natural orbitals was defined as the derivative of the total energy with respect to the occupation numbers at half filling for the orbital of interest .
this idea reproduces the bands of various periodic systems using the appropriate functional quite accurately . in the present work
we apply this approximation to the calculation of the ionization potentials and electron affinities of molecular systems using various functionals within the reduced density - matrix functional theory .
we demonstrate that this approximation is very successful in general and in particular for certain functionals it performs better than the direct determination of the ionization potentials and electron affinities through the calculation of positive and negative ions respectively .
the reason for this is identified to be the inaccuracy that arises from different handling of the open- and closed - shell systems . .
And you have already written the first three sentences of the full article: it is generally accepted today that the fermi surfaces of metallic systems obtained with density functional theory ( dft ) , even at the level of local density approximation ( lda ) , are in good agreement with experiments .
unfortunately , this is not the case with the band gaps of insulators and semiconductors which are highly underestimated by most of the exchange - correlation ( xc ) functionals within dft .
even with the exact xc functional of dft , the kohn - sham ( ks ) gap is not expected to reproduce the experimental gap@xcite ..
Please generate the next two sentences of the article
|
this deviation from experiment is most dramatic for mott - insulators , most of which are predicted by their ks spectrum to be metallic while they are experimentally known to be insulating in nature . in this regard reduced density matrix functional theory ( rdmft ) has shown great promise in improving on dft results for a wide class of systems in that it not only improves the ks - band gaps for insulators in general , but also predicts the correct insulating nature for mott insulators @xcite . within rdmft
the total energy of a system of interacting electrons is expressed in terms of the one - body reduced density matrix ( 1-rdm ) , @xmath0 .
|
12,260 |
Suppose that you have an abstract for a scientific paper: the attack of novel avian influenza ( h7n9 ) in east china caused a serious health crisis and public panic . in this paper , we empirically analyze the onset patterns of human cases of the novel avian influenza and observe several spatial and temporal properties that are similar to other infective diseases . more deeply , using the empirical analysis and modeling studies , we find that the spatio - temporal network that connects the cities with human cases along the order of outbreak timing emerges two - section - power - law edge - length distribution , indicating the picture that several islands with higher and heterogeneous risk straggle in east china .
the proposed method is applicable to the analysis on the spreading situation in early stage of disease outbreak using quite limited dataset .
avian influenza ( h7n9 ) , outbreak patterns , connecting nearest - existing - node network , edge - length distribution , two - section power law + 89.75.fb , 05.40.fb , 89.75.da .
And you have already written the first three sentences of the full article: in the spring of 2013 , a novel avian influenza , h7n9 virus , has broken out @xcite .
this new type of influenza has affected at least 132 people ( the total reported human cases until june 30 , 2013 ) and resulted in a huge social panic and billions dollars economic losses , even though there is no evidence of human - to - human transmission has been found so far @xcite . and also , several virological researches indicated that h7n9 virus has potential to be a novel disease with strong human - to - human infection @xcite . comparing with other avian influenzas without the capability of sustained human - to - human transmission ( e.g. h5n1 ) ,
a notable difference between them is that the birds symptom of h7n9 usually is inapparent @xcite , even though the spreading of h7n9 virus in birds and poultry is quite fast ..
Please generate the next two sentences of the article
|
some typical warning signals for the outbreak of avian influenza , such as the death of large number of wild and domestic birds , can not be observed in the process of the h7n9 s spreading .
it causes many serious troubles in the monitor of the epidemic situation and the estimation of public health risk on h7n9 , due to the fact that usually the spreading within birds and poultry is not visible until the outbreak of human cases .
|
12,261 |
Suppose that you have an abstract for a scientific paper: a simple model of how objects of different masses stream towards each other as they cluster gravitationally is described .
the model shows how the mean streaming velocity of dark matter particles is related to the motions of the parent dark matter haloes .
it also provides a reasonably accurate description of how the pairwise velocity dispersion of dark matter particles differs from that of the parent haloes .
the analysis is then extended to describe the streaming motions of galaxies .
this shows explicitly that the streaming motions measured in a given galaxy sample depend on how the sample was selected , and shows how to account for this dependence on sample selection .
in addition , we show that the pairwise dispersion should also depend on sample type .
our model predicts that , on small scales , redshift space distortions should affect red galaxies more strongly than blue .
galaxies : clustering cosmology : theory dark matter . .
And you have already written the first three sentences of the full article: gravity makes objects cluster .
therefore , the motions of objects towards each other may provide information about the background cosmology .
of course , different subsets of the clustering particles may trace the underlying streaming motions differently ..
Please generate the next two sentences of the article
|
the scale dependence of the mean streaming @xmath0 of dark matter particles has been understood for some time now ( hamilton et al .
1991 ; nityananda & padmanabhan 1994 ) .
|
12,262 |
Suppose that you have an abstract for a scientific paper: we present the discovery of spectacular double x - ray tails associated with and a possibly heated x - ray tail associated with , both late - type galaxies in the closest rich cluster abell 3627 .
a deep observation of allows us for the first time to examine the spatial and spectral properties of such x - ray tails in detail . besides the known bright tail that extends to @xmath0 80 kpc from , a fainter and narrower secondary tail with a similar length was surprisingly revealed , as well as some intriguing substructures in the main tail .
there is little temperature variation along both tails .
the widths of the secondary tail and the greater part of the main tail also remain nearly constant with the distance from the galaxy .
all these results challenge the current simulations .
the data also reveal 19 x - ray point sources around the x - ray tails .
we identified six x - ray point sources as candidates of intracluster ulxs with @xmath1 of up to 2.5@xmath2 erg s@xmath3 .
spectra of intracluster hii regions downstream of are also presented , as well as the velocity map of these hii regions that shows the imprint of s disk rotation .
for the first time , we unambiguously know that active star formation can happen in the cold ism stripped by icm ram pressure and it may contribute a significant amount of the intracluster light .
we also report the discovery of a 40 kpc x - ray tail of another late - type galaxy in a3627 , .
its x - ray tail seems hot , @xmath0 2 kev ( compared to @xmath0 0.8 kev for s tails ) .
the h@xmath4 data for are also presented .
we conclude that the high pressure environment around these two galaxies is important for their bright x - ray tails and the intracluster star formation .
the soft x - ray tails can reveal a great deal of the thermal history of the stripped cold ism in mixing with the hot icm , which is discussed along with intracluster star formation . .
And you have already written the first three sentences of the full article: the intracluster medium ( icm ) has long been proposed to play a vital role in galaxy evolution in clusters , through ram pressure and turbulent / viscous stripping of the galactic cold gas ( e.g. , gunn & gott 1972 ; nulsen 1982 ; quilis et al . 2000 ) .
as the halo gas and the cold interstellar medium ( ism ) is depleted in the stripping process , the galactic star formation will eventually be shut down and blue disk galaxies may turn into red galaxies ( e.g. , quilis et al . 2000 ) .
the removal of the cold ism also affects the accretion history of the central smbh ..
Please generate the next two sentences of the article
|
stripping of the ism of the disk galaxies in clusters has been extensively studied in simulations recently , with better resolution and more physics included ( e.g. , abadi et al .
1999 ; stevens et al . 1999 ; quilis et al . 2000 ; schulz & struck 2001 ; bekki & couch 2003 ; roediger & hensler 2005 ; kapferer et al .
|
12,263 |
Suppose that you have an abstract for a scientific paper: in this paper the single and multibunch emittance growths in the main linac of a linear collider are analytically treated in analogy to the brownian motion of a molecule , and the analytical formulae for the emittance growth due to accelerating structure misalignment errors are obtained by solving langevin equation .
the same set of formulae is derived also by solving directly fokker - planck equation .
comparisons with numerical simulation results are made and the agreement is quite well .
= -1 cm 0 0 # 1#2#3_phys .
rep . _ * # 1 * ( # 2 ) # 3 # 1#2#3_phys .
rev . _
* d#1 * ( # 2 ) # 3 + 2.5 cm * analytical treatment of the emittance growth + in the main linacs of future linear colliders * * jie gao * * laboratoire de lacclrateur linaire + * in2p3-cnrs et universit de paris - sud , bp 34 , f-91898 orsay cedex .
And you have already written the first three sentences of the full article: to achieve the required luminosity in a future e@xmath0e@xmath1 linear collider one has to produce two colliding beams at the interaction point ( ip ) with extremely small transverse beam dimensions . according to the linear collider design principles described in ref . 1
, the normalized beam emittance in the vertical plane ( the normalized beam emittance in the horizontal plane is larger ) at ip can be expressed as : @xmath2 where @xmath3 is the normalized beam energy , @xmath4 m is the classical electron radius , @xmath5 is the fine structure constant , @xmath6 is the maximum tolerable beamstrahlung energy spread , and @xmath7 is the mean number of beamstrahlung photons per electron at ip . taking @xmath8 and @xmath9 , one finds @xmath10mrad . to produce beams of this
small transverse emittance damping rings seem to be the only known facilities which have the potential to do this job ..
Please generate the next two sentences of the article
|
the questions now are that once a beam of this small emittance is produced at the exit of the damping ring , how about the emittance growth during the long passage through the accelerating structures and the focusing channels from the damping ring at the beam energy of few gev to the ip with the beam energy of a few hundred of gev , and how to preserve it ?
many works have been dedicated to answer these questions @xcite@xcite@xcite@xcite . to start with , in sections 2 , 3 , and 4
|
12,264 |
Suppose that you have an abstract for a scientific paper: se resume un conjunto de resultados de perfil terico [ 1 - 10 ] , relativos a espectros de energas , densidad de estados excitados , polarizacin del espn , transporte a travs de barreras de potencial , y propiedades pticas ( absorcin en el infra - rojo , luminiscencia ) de sistemas tales como puntos cunticos semiconductores y trampas de tomos .
la caracterstica fundamental de los sistemas investigados consiste en que contienen un nmero de partculas entre 4 y 400 , lo cual hace muy difcil el clculo de sus propiedades . en los trabajos presentados se resalta y se hace amplio uso de la analoga entre estos sistemas y los ncleos atmicos por lo que se adaptaron mtodos de la fsica nuclear tales como : hartree - fock y la rpa para sistemas finitos , el mtodo bcs y la proyeccin de lipkin - nogami y la ecuacin de bethe - goldstone .
adems , se resolvi la ecuacin de schrodinger utilizando bases de funciones de hasta 40,000 elementos utilizando el algoritmo de lanczos y se implementaron otros mtodos como el de monte carlo variacional y los aproximantes dobles de pad .
por ltimo , se propuso un mtodo estocstico para proyectar la funcin de onda bcs .
a set of theoretical results [ 1 - 10 ] is reviewed , which concern calculations of energy spectra , density of energy levels , spin polarization , transport and optical properties ( infrared absorption , luminescence ) of semiconductor quantum dots and atomic traps .
the studied systems contain a number of particles between 4 and 400 , thus the calculation of their physical properties is a hard task .
the analogy between these systems and the atomic nuclei is stressed and used throughout the paper .
common nuclear physics methods like hartree - fock and rpa schemes for finite systems , the bcs approach and the lipkin - nogami projection , and the bethe - goldstone equation were adapted to the present context . on the other hand ,
the schrodinger equation was solved in basis with up to 40,000 functions by means of the lanczos algorithm , and other methods....
And you have already written the first three sentences of the full article: en el trabajo [ 1 ] se calcul la energa del estado base de sistemas de hasta 210 bosones ( tomos con espn entero ) confinados en una trampa .
el clculo se hizo por dos vas : analticamente utilizando los denominados aproximantes dobles de pad [ 11 ] y a partir del denominado mtodo variacional de monte carlo [ 12 ] .
la novedad del trabajo consisti en la extensin del tratamiento analtico empleado en [ 11 ] para calcular el espectro de energas del excitn ( un sistemas de dos partculas : un electrn y un hueco ) a sistemas de cientos de partculas ..
Please generate the next two sentences of the article
|
para ello se hizo necesario calcular series para la energa en el lmite de interaccin dbil ( por teora de perturbaciones hasta segundo orden ) y en el lmite de interaccin fuerte ( oscilaciones de una denominada molcula de wigner ) . estas series son luego conectadas por medio de aproximantes dobles de pad .
por otro lado , el mtodo variacional de monte carlo combina el principio variacional de ritz con la tcnica de monte carlo para evaluar integrales multidimensionales .
|
12,265 |
Suppose that you have an abstract for a scientific paper: solving feasibility problems is a central task in mathematics and the applied sciences .
one particularly successful method is the douglas rachford algorithm . in this paper , we provide many new conditions sufficient for _ finite _ convergence .
numerous examples illustrate our results . *
2010 mathematics subject classification : * primary 47h09 , 90c25 ; secondary 47h05 , 49m27 , 65f10 , 65k05 , 65k10 . *
keywords : * averaged alternating reflections , douglas
rachford algorithm , feasibility problem , finite convergence , projector , reflector , .
And you have already written the first three sentences of the full article: the douglas rachford algorithm ( dra ) was first introduced in @xcite as an operator splitting technique to solve partial differential equations arising in heat conduction . as a result of findings by lions and mercier @xcite in the monotone operator setting
, the method has been extended to find solutions of the sum of two maximally monotone operators . when specialized to normal cone operators , the method is very useful in solving feasibility problems . to fix our setting , we assume throughout that equation i.e , a finite - dimensional real hilbert space with inner product @xmath0 and induced norm @xmath1 . given closed subsets @xmath2 and @xmath3 of @xmath4 with nonempty intersection , we consider the fundamental feasibility problem equation [ e : prob ] which frequently arises in science and engineering applications . a common approach for solving is to use projection algorithms that employ projectors onto the underlying sets ; see , e.g. , @xcite @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , @xcite , and the references therein . among those algorithms , the douglas
rachford algorithm applied to has attracted much attention ; see , e.g. , @xcite and @xcite and the references therein for further information . in the convex case.
Please generate the next two sentences of the article
|
, it is known , see , e.g. , lions and mercier @xcite and svaiter @xcite , that the sequence generated by the dra always converges while the `` shadow sequence '' converges to a point of the intersection .
even when the convex feasibility problem is inconsistent , i.e. , @xmath5 , it was shown in @xcite that the `` shadow sequence '' is bounded and its cluster points solve a best approximation problem ; the entire sequence converges if one of the sets is an affine subspace @xcite .
|
12,266 |
Suppose that you have an abstract for a scientific paper: we propose a model of an adaptive network of spiking neurons that gives rise to a hypernetwork of its dynamic states at the upper level of description . left to itself ,
the network exhibits a sequence of transient clustering which relates to a traffic in the hypernetwork in the form of a random walk .
receiving inputs the system is able to generate reproducible sequences corresponding to stimulus - specific paths in the hypernetwork .
we illustrate these basic notions by a simple network of discrete - time spiking neurons together with its fpga realization and analyze their properties . .
And you have already written the first three sentences of the full article: the interest to multiagent systems with entangled structures and nontrivial dynamics known as complex networks is stimulated by their prevalence in nature , technical applications and society , and by the common mathematical language mainly based on graph theory , statistical physics and nonlinear dynamics @xcite .
the most promising application field of the complex network view is neuroscience @xcite . revealing the architecture of structural links in neuronal structures as well as functional relations between anatomically remote brain regions allows formulating basic principles of the organization of the central nervous system in terms of complex networks and nonlinear dynamics @xcite .
new findings in neuroscience require developing novel concepts in mathematical descriptions ; for example , the hierarchical structure and activity in brain stimulates generalizations in network science , e.g. , temporal , multiplex , multilayer , multilevel networks @xcite , and hypernetworks @xcite ..
Please generate the next two sentences of the article
|
the ever - changing synaptic couplings lead to studying adaptive or evolving dynamical networks @xcite , impermanent nature of most perception and cognitive processes require shifting focus in nonlinear dynamics from attractors to transients @xcite .
the transient dynamics of spatiotemporal patterns and evolving architectures of synaptic links seem to be basic properties underlying most complex brain functions @xcite .
|
12,267 |
Suppose that you have an abstract for a scientific paper: the hyperfine structure ( hfs ) and the @xmath0 factor of a bound electron are caused by external magnetic fields .
for the hfs , the magnetic field is due to the nuclear spin .
a uniform - in - space and constant - in - time magnetic field is used to probe the bound - electron @xmath0 factor .
the self - energy corrections to these effects are more difficult to evaluate than those to the lamb shift . here , we describe a numerical approach for both effects in the notoriously problematic regime of hydrogen - like bound systems with low nuclear charge numbers . the calculation is nonperturbative in the binding coulomb field .
accurate numerical values for the remainder functions are provided for @xmath1 states and for @xmath2 states with @xmath3 . .
And you have already written the first three sentences of the full article: the interaction of a bound electron and an atomic nucleus is characterized by the parameter @xmath4 , where @xmath5 is the nuclear charge number and @xmath6 is the fine - structure constant .
this universal `` coupling parameter '' sets the scale for calculations of the radiative corrections to various bound - state effects including the hyperfine structure ( hfs ) and the bound - electron @xmath0 factor .
traditionally , theoretical investigations of radiative corrections in light systems relied upon an expansion in powers of @xmath7 and @xmath8.
Please generate the next two sentences of the article
|
. however , today it is desirable to advance theory beyond the predictive limits given by the highest available terms in the @xmath7-expansion .
this can be done by carrying out calculations with using nonperturbative ( in @xmath7 ) propagators .
|
12,268 |
Suppose that you have an abstract for a scientific paper: our aim was to identify gravitational lens candidates among some 5500 optical counterparts of the x - ray point - like sources in the medium - deep @xmath0 sq .
deg . xmm - lss survey .
we have visually inspected the optical counterparts of each qsos / agn using cfhtls t006 images .
we have selected compact pairs and groups of sources which could be multiply imaged qso / agn .
we have measured the colors and characterized the morphological types of the selected sources using the multiple psf fitting technique .
we found three good gravitational lens candidates : j021511.4 - 034306 , j022234.3 - 031616 and j022607.0 - 040301 which consist of pairs of point - like sources having similar colors . on the basis of a color - color diagram and x - ray properties
we could verify that all these sources are good qso / agn candidates rather than stars .
additional secondary gravitational lens candidates are also reported .
[ firstpage ] gravitational lensing : strong .
And you have already written the first three sentences of the full article: gravitational lensing remains a powerful tool for studies of dark matter distribution in the universe .
one important application of gravitational lens statistics is to provide strong constraints on the cosmological models and parameters since the lensing optical depth depends on the cosmological volume element ( surdej et al .
1992 , mitchell et al ..
Please generate the next two sentences of the article
|
2005 , oguri et al .
2008 , jullo et al .
|
12,269 |
Suppose that you have an abstract for a scientific paper: the number field sieve ( nfs ) algorithm is the best known method to compute discrete logarithms ( dl ) in finite fields @xmath0 , with @xmath1 medium to large and @xmath2 small .
this algorithm comprises four steps : polynomial selection , relation collection , linear algebra and finally , individual logarithm computation .
the first step outputs two polynomials defining two number fields , and a map from the polynomial ring over the integers modulo each of these polynomials to @xmath0 . after the relation collection and linear algebra phases ,
the ( virtual ) logarithm of a subset of elements in each number field is known .
given the target element in @xmath0 , the fourth step computes a preimage in one number field .
if one can write the target preimage as a product of elements of known ( virtual ) logarithm , then one can deduce the discrete logarithm of the target .
as recently shown by the logjam attack , this final step can be critical when it can be computed very quickly .
but we realized that computing an individual dl is much slower in medium- and large - characteristic non - prime fields @xmath0 with @xmath3 , compared to prime fields and quadratic fields @xmath4 .
we optimize the first part of individual dl : the _ booting step _ , by reducing dramatically the size of the preimage norm .
its smoothness probability is higher , hence the running - time of the booting step is much improved .
our method is very efficient for small extension fields with @xmath5 and applies to any @xmath6 , in medium and large characteristic . .
And you have already written the first three sentences of the full article: given a cyclic group @xmath7 and a generator @xmath8 of @xmath9 , the discrete logarithm ( dl ) of @xmath10 is the element @xmath11 such that @xmath12 .
in well - chosen groups , the exponentiation @xmath13 is very fast but computing @xmath14 from @xmath15 is conjectured to be very difficult : this is the discrete logarithm problem ( dlp ) , at the heart of many asymmetric cryptosystems .
the first group proposed for dlp was the multiplicative group of a prime finite field . nowadays , the group of points of elliptic curves defined over prime fields are replacing the prime fields for dlp - based cryptosystems . in pairing - based cryptography ,.
Please generate the next two sentences of the article
|
the finite fields are still used , because they are a piece in the pairing mechanism .
it is important in cryptography to know precisely the difficulty of dl computation in the considered groups , to estimate the security of the cryptosystems using them .
|
12,270 |
Suppose that you have an abstract for a scientific paper: we present new photometry of hd 149026 spanning five transits of its `` super - neptune '' planet . in combination with previous data ,
we improve upon the determination of the planet - to - star radius ratio : @xmath0 .
we find the planetary radius to be @xmath1 @xmath2 , in accordance with previous theoretical models invoking a high metal abundance for the planet .
the limiting error is the uncertainty in the stellar radius .
although we find agreement among four different ways of estimating the stellar radius , the uncertainty remains at 7% .
we also present a refined transit ephemeris and a constraint on the orbital eccentricity and argument of pericenter , @xmath3 , based on the measured interval between primary and secondary transits . .
And you have already written the first three sentences of the full article: many clues about the processes of planet formation and evolution have been discovered by studying the ensemble properties of exoplanets , such as the `` brown dwarf desert '' ( halbwachs et al .
2000 , marcy & butler 2000 ) and the tendency for metal - rich stars to have more detectable planets ( santos et al .
2003 , fischer & valenti 2005 ) . however , there are also individual exoplanets whose properties bear directly on theories of planet formation and evolution.
Please generate the next two sentences of the article
|
. one of the best examples is the transiting planet hd 149026b ( sato et al .
2005 ) .
|
12,271 |
Suppose that you have an abstract for a scientific paper: supermassive stars ( smss ; @xmath0 ) formed in the first protogalaxies with virial temperature @xmath1 k are expected to collapse into seeds of supermassive black hole in the high - redshift universe ( @xmath2 ) .
fragmentation of the primordial gas is , however , a possible obstacle to sms formation .
we discuss the expected properties of a compact , metal - free , marginally unstable nuclear protogalactic disc , and the fate of the clumps formed in the disc by gravitational instability .
interior to a characteristic radius @xmath3 pc , the disc fragments into massive clumps with @xmath4 .
the clumps grow via accretion and migrate inward rapidly on a time - scale of @xmath5 yr , which is comparable or shorter than the kelvin - helmholtz time @xmath6 yr .
some clumps may evolve to zero - age main - sequence stars and halt gas accretion by radiative feedback , but most of the clumps can migrate inward and merge with the central protostar before forming massive stars .
moreover , we found that dust - induced fragmentation in metal - enriched gas does not modify these conclusions unless @xmath7 , because clump migration below this metallicity remains as rapid as in the primordial case .
our results suggest that fragmentation of a compact , metal - poor disc can not prevent the formation of an sms .
quasars : general cosmology : theory dark ages , reionization , first stars . .
And you have already written the first three sentences of the full article: observations of high - redshift quasars reveal that supermassive black holes ( smbhs ) with mass of @xmath8 already exist as early as redshifts @xmath9 @xcite . gas accretion and mergers of the remnant black holes ( bhs ) formed by the collapse of first - generation stars ( @xmath10 )
have been considered for producing such smbhs ( e.g. * ? ? ?
* ; * ? ? ?.
Please generate the next two sentences of the article
|
* ; * ? ? ?
however , various forms of radiative feedback can prevent efficient bh growth , making it difficult to reach @xmath8 within the age of the high - redshift universe @xcite .
|
12,272 |
Suppose that you have an abstract for a scientific paper: in the framework of the soft - collinear effective theory , we demonstrate that the leading - power heavy - to - light baryonic form factors at large recoil obey the heavy quark and large energy symmetries .
symmetry breaking effects are suppressed by @xmath0 or @xmath1 , where @xmath2 is the hadronic scale , @xmath3 is the @xmath4 quark mass and @xmath5 is the energy of light baryon in the final state . at leading order , the leading power baryonic form factor @xmath6 , in which two hard - collinear gluons are exchanged in the baryon constituents , can factorize into the soft and collinear matrix elements convoluted with a hard - kernel of order @xmath7 . including the energy release dependence
, we derive the scaling law @xmath8 .
we also find that this form factor @xmath9 is numerically smaller than the form factor governed by soft processes , although the latter is formally power - suppressed .
* keywords : * heavy quark physics , qcd , b - physics .
And you have already written the first three sentences of the full article: precision test of the unitarity of the ckm matrix , allowing us to explore the sm description of the cp violation and reveal any physics beyond the sm , greatly depends on our knowledge of the nonperturbative matrix elements .
fortunately the calculation of the amplitudes of bottom meson decays is under control as the amplitudes can be expanded in terms of small ratios justified by both the large @xmath4-quark mass , and a large energy release in the decay . with this expansion ,
a number of theoretical predictions on different observables in various channels are found in global agreement with experimental measurements ( see ref ..
Please generate the next two sentences of the article
|
@xcite for a review ) .
decay processes of heavy baryons consisting of a bottom quark provide complementary information with the @xmath10 meson and thereby are receiving growing attentions on both experimental and theoretical sides .
|
12,273 |
Suppose that you have an abstract for a scientific paper: we present a modification of the method of conical resolutions @xcite .
we apply our construction to compute the rational cohomology of the spaces of equations of nodal cubics in @xmath0 , nodal quartics in @xmath0 and nodal cubics in @xmath1 . in the last two cases we also compute the cohomology of the corresponding moduli spaces . .
And you have already written the first three sentences of the full article: in many situations , geometric objects come parametrized by the elements of an affine space @xmath2 over a field @xmath3 or @xmath4 ; the elements of @xmath2 can usually be divided into `` generic '' and `` singular '' ( what exactly we call `` singular '' depends on the particular example we are considering ) .
the subset @xmath5 of @xmath2 formed by the singular elements is called a ( generalized ) _ discriminant_. to give an example , one can take the space of polynomials of some fixed degree over @xmath6 as @xmath2 , and the subset of @xmath2 formed by the polynomials having a multiple root in @xmath6 as @xmath5 .
notice that in this example @xmath5 is the zero locus of a polynomial in the coefficients of @xmath7 ; this polynomial is called the discriminant , which maybe justifies the use of the term `` discriminant '' in a more general situation ..
Please generate the next two sentences of the article
|
more examples will be considered below . due to the alexander duality
@xmath8 computing ( additively ) the cohomology of @xmath9 is equivalent to computing the borel - moore homology groups of @xmath5 .
|
12,274 |
Suppose that you have an abstract for a scientific paper: the recent advent of wave - shaping methods has demonstrated the focusing of light through and inside even the most strongly scattering materials . typically in wavefront
shaping , light is focused in an area with the size of one speckle spot .
it has been shown that the intensity is not only increased in the target speckle spot , but also in an area outside the optimized speckle spot .
consequently , the total transmission is enhanced , even though only the intensity in a single speckle spot is controlled . here ,
we experimentally study how the intensity enhancement on both interfaces of a scattering medium depends on the optimization area on the transmission side .
we observe that as the optimization radius increases , the enhancement of the total transmitted intensity increases .
we find a concomitant decrease of the total reflected intensity , which implies an energy redistribution between transmission and reflection channels .
in addition , we find a qualitative evidence of a long - range reflection - transmission correlation .
our result is useful for efficient light harvesting in solar cells , multi - channel quantum secure communications , imaging , and complex beam delivery through a scattering medium . .
And you have already written the first three sentences of the full article: wave interference in disordered scattering media results in speckles through the coherent addition of multiple waves , which are independent and have random amplitudes and phases @xcite . between these interfering waves ,
there exist short- , long- , and even infinite - range correlations @xcite .
these correlations have provided enriching information about mesoscopic transport , as well as a deeper understanding of fundamental phenomena such as enhanced backscattering @xcite and anderson localization @xcite . in 1990 , using speckle correlations , freund predicted that an opaque scattering medium can be used as a lens and other optical elements by designing an appropriate incident wavefront @xcite . only recently , this prediction was confirmed by the advent of innovative wave - shaping methods such as wavefront shaping @xcite , time reversal @xcite , phase conjugation @xcite , and transmission - matrix - based control @xcite . in wavefront.
Please generate the next two sentences of the article
|
shaping , an optimization algorithm receives as a feedback the intensity in a target area , typically one speckle spot with an area @xmath0 .
the algorithm then modifies the spatial phase of the incident field on the scattering medium , such that the intensity in the target spot is maximized .
|
12,275 |
Suppose that you have an abstract for a scientific paper: we present three - dimensional magnetohydrodynamic ( mhd ) simulations of superbubbles , to study the importance of mhd effects in the interpretation of images from recent surveys of the galactic plane .
these simulations focus mainly on atmospheres defined by an exponential density distribution and the density distribution . in each case
, the magnetic field is parallel to the galactic plane and we investigate cases with either infinite scale height ( constant magnetic field ) or a constant ratio of gas pressure to magnetic pressure .
the three - dimensional structure of superbubbles in these simulations is discussed with emphasis on the axial ratio of the cavity as a function of magnetic field strength and the age of the bubble .
we investigate systematic errors in the age of the bubble and scale height of the surrounding medium that may be introduced by modeling the data with purely hydrodynamic models .
age estimates derived with symmetric hydrodynamic models fitted to an asymmetric magnetized superbubble can differ by up to a factor of four , depending on the direction of the line of sight .
the scale height of the surrounding medium based on the kompaneets model may be up to 50% lower than the actual scale height .
we also present the first ever predictions of faraday rotation by a magnetized superbubble based on three - dimensional mhd simulations .
we emphasize the importance of mhd effects in the interpretation of observations of superbubbles . .
And you have already written the first three sentences of the full article: the combined stellar wind and supernova ejecta of groups of o and b stars blow large bubbles in the interstellar medium .
the largest of these bubbles , with size scales of 100 pc to 1 kpc are commonly referred to as superbubbles .
the basic structure of a superbubble consists of a hot low - density interior , the cavity , surrounded by a cool shell of swept - up interstellar medium ..
Please generate the next two sentences of the article
|
the continuous formation and dissipation of superbubbles is an important factor in the energy balance of the interstellar medium , and determines the locations of different phases of the interstellar medium on large scales @xcite .
compression of the interstellar medium in the shell may increase cooling and trigger the formation of a new generation of stars . also , the ability of large superbubbles to break out of the disk of a galaxy and initiate an outflow of chemically enriched plasma and ionizing radiation from the disk into the halo has a profound influence on the evolution of galaxies .
|
12,276 |
Suppose that you have an abstract for a scientific paper: we study the quiet sun magnetic fields using spectropolarimetric observations of the infrared and visible fe i lines at 6301.5 , 6302.5 , 15648 and 15653 .
magnetic field strengths and filling factors are inferred by the simultaneous fit of the observed stokes profiles under the misma hypothesis .
the observations cover an intra - network region at the solar disk center .
we analyze 2280 stokes profiles whose polarization signals are above noise in the two spectral ranges , which correspond to 40% of the field of view . most of these profiles can be reproduced only with a model atmosphere including 3 magnetic components with very different field strengths , which indicates the co - existence of kg and sub - kg fields in our 15 resolution elements .
we measure an unsigned magnetic flux density of 9.6 g considering the full field of view .
half of the pixels present magnetic fields with mixed polarities in the resolution element .
the fraction of mixed polarities increases as the polarization weakens .
we compute the probability density function of finding each magnetic field strength .
it has a significant contribution of kg field strengths , which concentrates most of the observed magnetic flux and energy .
this kg contribution has a preferred magnetic polarity , while the polarity of the weak fields is balanced . .
And you have already written the first three sentences of the full article: the quiet sun can be defined as that part of the sun far from magnetic activity .
if we exclude plages and network , the remaining quiet area covers 90% of the surface of the sun , and remains almost unchanged during the solar cycle ( e.g. , * ? ? ?
few decades ago , this internetwork ( in ) was thought to be almost devoid of magnetic fields and consequently , its relevance for the solar magnetism was not obvious @xcite ..
Please generate the next two sentences of the article
|
however , with the present instrumentation , when the spatial resolution is around 1@xmath0 , the quiet sun turns out to be full of magnetic fields @xcite , with an unsigned flux density measured with techniques based on the zeeman effect of the order of 10 g ( e.g. , * ? ? ?
* ; * ? ? ?
|
12,277 |
Suppose that you have an abstract for a scientific paper: we review the renormalisation group evolution of quark and lepton masses , mixing angles and phases both in the ued extension of the standard model and of the minimal supersymmetric standard model .
we consider two typical scenarios : all matter fields propagating in the bulk , and matter fields constrained to the brane .
the resulting renormalisation group evolution equations in these scenarios are compared with the existing results in the literature , together with their implications . .
And you have already written the first three sentences of the full article: the standard model ( sm ) , by meeting all confrontations with experiments , stands as a remarkably simple parameterisation of known physics .
yet it has many unsatisfactory aspects which leads to a belief that there must exist a simpler underlying structure of which the sm is the low energy piece .
this structure is believed to make its appearance at much higher energies , where we can approach this with renormalisation group techniques to extrapolate the sm parameters to the unexplored scales @xcite ..
Please generate the next two sentences of the article
|
recalling that in the sm , the runnings of the gauge , yukawa and quartic scalar couplings are logarithmic with the energy scale , the gauge couplings do not all meet at a point , but do tend to unify near @xmath0 gev .
extensions to the sm such as extra - dimensional scenarios accessible to sm fields have the virtue , thanks to the couplings now having a power law running , of bringing the unification scale down to an explorable range @xcite . note that many other extensions to the sm exist which alter the runnings in different ways , such as supersymmetry ( susy ) , where a range of new particles ensure the gauge couplings do meet at a point , but runnings remain logarithmic @xcite .
|
12,278 |
Suppose that you have an abstract for a scientific paper: we performed the numerical simulation of quantum turbulence produced by thermal counterflow in superfluid @xmath0he by using the vortex filament model .
the pioneering work was made by schwarz , which has two defects .
one is neglecting non - local terms of the biot - savart integral ( localized induction approximation , lia ) , and the other is the unphysical mixing procedure in order to sustain the statistically steady state of turbulence .
we succeeded in making the statistically steady state without the lia and the mixing .
this state shows the characteristic relation @xmath1 between the line - length - density @xmath2 and the counterflow relative velocity @xmath3 with the quantitative agreement of the coefficient @xmath4 with some typical observations .
we compare our numerical results to the observation of experiment by paoletti _
et al _ , where thermal couterflow was visualized by solid hydrogen particles . .
And you have already written the first three sentences of the full article: quantum turbulence(qt ) , which consists of a tangle of quantized vortices , has been investigated since the thermal counterflow experiments of vinen [ 1 - 4 ] half a century ago , while the underlying physics is far from being fully understood [ 5,6 ] .
the numerical simulations are the useful source of knowledge about qt , because the whole dynamics of this system is too complicated to be described analytically .
one of the powerful schemes of the simulation is the vortex filament model based on pioneering works by schwarz [ 7,8 ] ..
Please generate the next two sentences of the article
|
schwarz performed the numerical simulation of counterflow turbulence under the periodic boundary condition by using the localized induction approximation ( lia ) which neglects a non - local term of the biot - savart integral [ 8 ] .
however he could not obtain the statistically steady state ( sss ) because the vortices lie in planes normal to @xmath5 to prevent them from reconnecting .
|
12,279 |
Suppose that you have an abstract for a scientific paper: we derive a general expression for the gauge invariant mass ( @xmath0 ) for an abelian gauge field , as induced by vacuum polarization , in @xmath1 dimensions . from its relation to the chiral anomaly , we show that @xmath0 has to satisfy a certain quantization condition .
this quantization can be , on the other hand , explicitly verified by using the exact general expression for the gauge invariant mass in terms of the fermion propagator .
this result is applied to some explicit examples , exploring the possibility of having interesting physical situations where the value of @xmath0 departs from its canonical value .
we also study the possibility of generalizing the results to the @xmath2 dimensional case at finite temperature , showing that there are indeed situations where a finite and non - vanishing gauge invariant mass is induced . .
And you have already written the first three sentences of the full article: some important physical quantities displaying quantization properties , may sometimes be represented by means of _ momentum _ space integrals which exhibit their topologically invariant character .
considerable effort has been devoted to find these representations , since they are often very useful to prove their quantization , as well as their stability under perturbations .
this is the case , for instance , of the transverse conductivity @xmath3 in @xmath4 , which can be represented as a momentum space integral given by @xcite @xmath5 \ , \ ] ] where @xmath6 is the full fermion propagator ..
Please generate the next two sentences of the article
|
as shown in @xcite , due to the ultraviolet behavior of the fermion propagator , this integral reduces to the kronecker topological invariant which labels the homotopy classes in @xmath7 , that is , @xmath3 is quantized .
a similar representation for the induced chern - simons coefficient has been obtained in @xcite by using a cubic lattice regularization for the euclidean fermionic action . in this case , the possible values for the chern - simons coefficient turn out to be labeled by the winding number characterizing the mapping between the three - dimensional torus in momentum space and the normalized quaternion corresponding to the fermion propagator : @xmath8 .
|
12,280 |
Suppose that you have an abstract for a scientific paper: we have performed powder neutron diffraction on the new superconductor , ceni@xmath0bi@xmath1 with a superconducting transtion temperature @xmath2 4.2 k. the structural parameters of this compound at room temperature are determined by rietveld analysis .
below about 5 k , the clear magnetic bragg peaks with propagation vector @xmath3=(0 0 0 ) are observed .
the observed intensities of magnetic bragg peaks can be explained by the magnetic structure that the two ce moments in the unit cell are antiparallel along @xmath4 axis .
the magnetic bragg peaks are observed in the superconducting state , indicating the coexistence of the antiferromagnetic ordering and the superconductivity in this compound .
the intensity of magnetic bragg peak monotonously increases with decreasing temperature below @xmath5 and does not exhibit apparent anomaly at @xmath6 , obviously different from cases of heavy fermion superconductors in which the magnetic ordering and the superconductivity coexist , for example , cd - doped cecoin@xmath7 .
these results suggest that the 4@xmath8 electron of the ce atom is not coupled with the superconducting carrier , and the magnetic ordering is almost independent of the superconductivity in ceni@xmath0bi@xmath1 . .
And you have already written the first three sentences of the full article: an iron - based superconductor was first discovered in the lafeaso system with a so - called zrcusias - type structure whose superconductivity is induced by partial substitution of flourine for oxygen.@xcite after this discovery , the development of new materials with an fe layer in which the superconductivity is considered to appear , have been performed , resulting in the discoveries of other iron - based superconductors , such as the so - called 122 system,@xcite fese@xmath9te@xmath10,@xcite lifeas,@xcite and so on . on the other hand , new superconductors with a zrcusias - type structure which consist of elements other than fe are also explored , for example , la@xmath9sr@xmath10niaso@xcite .
recently , mizoguchi and his collaborators have discovered the superconductivity in ceni@xmath0bi@xmath1 with a superconducting transition temperature @xmath2 4.2 k.@xcite series compounds cembi@xmath1 and cemsb@xmath1 have zrcusias - type structures with space group of @xmath11 corresponding to the so - called 1111 system , where m is a transition metal element such as mn , fe , ni , cu , ag , and so on.@xcite for cembi@xmath1 , bi1 , m , ce and bi2 sites correspond to as , fe , rare earth element and o sites , respectively .
the `` parent '' compound of ceni@xmath0bi@xmath1 , cenibi@xmath1 is a moderately heavy fermion antiferromagnet ; magnetic ordering appears at about 5 k and the electronic specific heat coefficient @xmath12 is relatively large ( 470 mj / k@xmath13 mol).@xcite this parent compound does not exhibit a superconductivity although the electric conductivity is metallic down to the lowest temperature.@xcite the superconductivity is induced by the deficiency of ni atom,@xcite as the superconductivity in the iron - based superconductor of the so - called 1111 system is induced by oxygen - deficiency.@xcite the resistivity and superconducting shielding signal in the magnetic field show the superconducting transition at about 4.2 k. at about 5 k , specific heat @xmath14 exhibits a jump of....
Please generate the next two sentences of the article
|
the clear jump of the specific heat is not observed at around @xmath6 because the jump caused by the superconducting transition is much smaller than the jump caused by the magnetic ordering , suggesting that the charge carrier which causes the superconductivity is not coupled with the ce 4@xmath8 electron and the mass is not enhanced.@xcite if the ce 4@xmath8 electron is coupled with the superconducting carrier in the present compound , the magnetic fluctuation of 4@xmath8 electron can induce the unconventional superconducting order parameter . in such a case , temperature dependence of the magnetic bragg peak should have some anomaly at @xmath6 .
then we have performed powder neutron diffraction measurements on ceni@xmath0bi@xmath1 in order to investigate the existence of the coupling between the ce 4@xmath8 electron and the superconducting carrier .
|
12,281 |
Suppose that you have an abstract for a scientific paper: we review the possibility that the supersymmetric standard model arises from orbifold constructions of the @xmath0 heterotic superstring , and the phenomenological properties that such a model should have .
in particular , trying to solve the discrepancy between the unification scale predicted by the heterotic superstring ( @xmath1 gev ) and the value deduced from lep experiments ( @xmath2 gev ) , we will predict the presence at low energies of three families of higgses and vector - like colour triplets .
our approach relies on the fayet - iliopoulos breaking , and this is also a crucial ingredient , together with having three higgs families , to obtain in these models an interesting pattern of fermion masses and mixing angles at the renormalizable lebel .
namely , after the gauge breaking some physical particles appear combined with other states , and the yukawa couplings are modified in a well controlled way . on the other hand
, dangerous flavour - changing neutral currents may appear when fermions of a given charge receive their mass through couplings with several higgs doublets .
we will address this potential problem , finding that viable scenarios can be obtained for a reasonable light higgs spectrum . .
And you have already written the first three sentences of the full article: in superstring theory the elementary particles are not point - like objects but extended , string - like objects .
it is surprising that this apparently small change allows us to answer fundamental questions that in the context of the quantum field theory of point - like particles can not even be posed .
for example : why is the standard model gauge group @xmath3 ? why are there three families of particles ?.
Please generate the next two sentences of the article
|
why is the mass of the electron @xmath4 mev ?
why is the fine structure constant @xmath5 ?
|
12,282 |
Suppose that you have an abstract for a scientific paper: we exhibit a new relationship between dynamic and static semantics . we define the categorical outlay needed to define interaction graphs models , a generalisation of girard s geometry of interaction models , which strongly relate to game semantics .
we then show how this category is mapped to weighted relational models of linear logic .
this brings into vision a new bridge between the dynamic and static approaches , and provides formal grounds for considering interaction graphs models as quantitative versions of goi and game semantics models .
we finally proceed to show how the interaction graphs models relate to a very general notion of quantitative coherence spaces . .
And you have already written the first three sentences of the full article: this paper is about denotational semantics of ( a fragment of ) linear logic .
the focus is on ( denotational ) static and dynamic semantics , i.e. respectively _ semantics of proofs _ and _ semantics of proofs and their cut - elimination_. denotational semantics were introduced by scott @xcite as mathematical models for programming languages . through the proofs - as - programs correspondence , it is equivalent to study semantics of programs and semantics of proofs , and the current paper will focus on a fragment of linear logic .
denotational semantics are data - driven semantics , i.e. their focus is on data and data types ..
Please generate the next two sentences of the article
|
a program then corresponds to a function that maps some input data to some output data .
this view of _ programs as functions _
|
12,283 |
Suppose that you have an abstract for a scientific paper: we report a magnetoresistance study of the superconducting ferromagnet ucoge .
the data , taken on single - crystalline samples , show a pronounced structure at @xmath0 t for a field applied along the ordered moment @xmath1 .
angle dependent measurements reveal this field - induced phenomenon has an uniaxial anisotropy .
magnetoresistance measurements under pressure show a rapid increase of @xmath2 to 12.8 t at 1.0 gpa .
we discuss @xmath2 in terms of a field induced polarization change .
upper critical field measurements corroborate the unusual s - shaped @xmath3-curve for a field along the @xmath4-axis of the orthorhombic unit cell . .
And you have already written the first three sentences of the full article: the intermetallic compound ucoge belongs to the select group of superconducting ferromagnets @xcite . in this intriguing group of materials superconductivity
develops in the ferromagnetic state at a temperature @xmath5 well below the curie temperature @xmath6 for ferromagnetic ordering @xcite .
moreover , below @xmath5 , superconductivity and ferromagnetic order coexist on the microscopic scale ..
Please generate the next two sentences of the article
|
the superconducting ferromagnets discovered so far are uge@xmath7 ( under pressure , ref . ) , urhge ( ref . ) , uir ( under pressure , ref . ) and ucoge ( ref . ) .
the co - occurrence of ferromagnetism and superconductivity is at odds with the standard bcs ( bardeen - cooper - schrieffer ) scenario for phonon - mediated spin - singlet superconductivity , since the ferromagnetic exchange field impedes spin - singlet cooper pairing @xcite . instead
|
12,284 |
Suppose that you have an abstract for a scientific paper: we derive the mass term of the bardeen metric in the presence of a noncommutative geometry induced minimal length . in this setup , the proposal of a stable black hole remnant as a candidate to store information is confirmed .
we consider the possibility of having an extremal configuration with one degenerate event horizon and compare different sizes of black hole remnants . as a result , once the magnetic charge @xmath0 of the noncommutative bardeen solution becomes larger , both the minimal nonzero mass @xmath1 and the minimal nonzero horizon radius @xmath2 get larger .
this means , subsequently , under the condition of an adequate amount of @xmath0 , the three parameters @xmath0 , @xmath1 , and @xmath2 are in a connection with each other linearly . according to our results ,
a noncommutative bardeen black hole is colder than the noncommutative schwarzschild black hole and its remnant is bigger , so the minimum required energy for the formation of such a black hole at particle colliders will be larger .
we also find a closely similar result for the hayward solution . .
And you have already written the first three sentences of the full article: the issue of central singularity of a black hole ( bh ) is an open problem in bh physics .
although it is commonly accepted that only a not yet accessible quantum theory of gravity would be competent to solve the problem appropriately , several phenomenological scenarios have been considered in the literature in order to study bhs with regular centers ( for a review , see @xcite ) . in 1968
, bardeen @xcite introduced a compact object with an event horizon and without an intrinsic singularity , namely bardeen bh ; it is the first regular bh model in general relativity ..
Please generate the next two sentences of the article
|
the bardeen spacetime is spherically symmetric without violating the weak energy condition and the inside of the horizon is desitter - like wherein the matter has a high pressure . in 2000 , ayn - beato and garca @xcite reinterpreted the bardeen model as the gravitational field of a nonlinear magnetic monopole .
a few years later , hayward @xcite investigated the formation and evaporation of a new kind of the regular solution , i.e. hayward bh , in which its static region is bardeen - like and the dynamic regions are vaidya - like .
|
12,285 |
Suppose that you have an abstract for a scientific paper: in this paper a prescription for generating an equilibrium spherical system depicted with cuspy density profiles is extended to a core density profile , the burkert profile , which is observationally more suitable to dwarfs . by using a time - saving monte carlo method instead of n - body simulations ,
we show that the burkert halo initialized with the distribution function that depends only on energy is in a practically stable equilibrium . the one generated using
the local maxwellian approximation is unstable , where the flat core density structure tends to steepen .
this is fundamentally different from the previous study on a halo with cuspy density profile .
the deviation of the unstable `` burkert '' from the initial burkert profile is found to be closely related to taking a gaussian as the velocity distribution at any given point .
the significance of not using the local maxwellian approximation is further demonstrated by exploring the dynamical evolution of compact super star clusters in the burkert halo . in particular
, the local maxwellian approximation will result in underestimating the dynamical friction and overestimating sinking time scale .
accordingly , it will lead to lower probability of forming massive bulges and young nuclear star clusters in bulgeless galaxies . .
And you have already written the first three sentences of the full article: generating initial conditions for numerical experiments of a system with a certain density profile is a well - defined but difficult procedure .
there are two steps for constructing the initial conditions of one desired model : 1 ) calculate the steady - state distribution function of the desired model ; 2 ) use monte carlo method to generate the initial conditions .
the main difficulty comes from the first step ..
Please generate the next two sentences of the article
|
one possibility is to make some simplifying approximations about the nature of the distribution function ( @xcite ; @xcite ) .
hernquist ( 1993 ) described a prescription for constructing n - body realization assuming that velocity distribution at any given point is maxwellian .
|
12,286 |
Suppose that you have an abstract for a scientific paper: using the quark mass density- and temperature dependent model , we have studied the thermodynamical properties and the stability of strangelet at finite temperature .
the temperature , charge and strangeness dependences on the stability of strangelet are investigated .
we find that the stable strangelets are only occured in the high strangeness and high negative charge region . .
And you have already written the first three sentences of the full article: the study of small lumps of strange quark matter , called strangelets , plays an important role for research the quark gluon plasma ( qgp ) in recent relativistic heavy ion collision ( rhic ) experiments .
the reason is that although many signatures of qgp such as @xmath0 suppression , strangeness enhancement , thermal dilepton electro magnetic radiation , etc .
, have been found @xcite , but it is still ambiguous because these signatures can also be explained by hadron gas @xcite . to search.
Please generate the next two sentences of the article
|
an unambiguous signature of qgp is the key for rhic experiments .
the strangelet , as was argued by greiner et .
|
12,287 |
Suppose that you have an abstract for a scientific paper: self - organization effects related to light amplification in the collective atomic recoil laser system with the driven atoms confined in a harmonic trap are investigated further . in the dispersive parametric region , our study reveals that the spontaneously formed structures in the phase space contributes an important role to the light amplification of the probe field under the atomic motion being modified by the trap . .
And you have already written the first three sentences of the full article: optical amplification in a strongly driven sodium atoms system without population inversions has been observed in the experiment @xcite where the atomic recoil effect and doppler shift were purposely avoided by a specific systematic configuration .
when the pumping field is off - detuned from the atomic transition frequency @xmath0 , the experimental pump - probe gain spectrum exhibits a normal absorption - gain profile similar to that of fig.1(a ) which is drawn from a direct simulation and has been obtained by bonifacio _
et al _ in their original work @xcite . of the probe field versus pump - probe detuning @xmath1 with parameters @xmath2 , @xmath3 , @xmath4 , @xmath5 , @xmath6 and @xmath7 . ( a ) the atomic motion is totally removed from the model ; ( b ) the motion effect is included ( traditional carl).,title="fig : " ] of the probe field versus pump - probe detuning @xmath1 with parameters @xmath2 , @xmath3 , @xmath4 , @xmath5 , @xmath6 and @xmath7 ..
Please generate the next two sentences of the article
|
( a ) the atomic motion is totally removed from the model ; ( b ) the motion effect is included ( traditional carl).,title="fig : " ] the vertical ordinate of fig.1 stands for a relative gain of the probe field and the horizontal ordinate @xmath8 denotes the detuning between the pump and the probe field
. however , this anti - symmetry gain profile around @xmath9 can be drastically changed ( fig.1(b ) ) by the atomic recoil motion which plays an important role in the amplification mechanism of the collective atomic recoil laser ( carl ) @xcite . as shown in fig.1(b ) , the gain peak within the traditional madey region @xcite is greatly enhanced , and which has been a signature of light amplification induced by cooperative atomic recoil effect .
|
12,288 |
Suppose that you have an abstract for a scientific paper: the effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically .
pair potentials between capillary monopoles and dipoles , corresponding to particles floating on a droplet with a fixed center of mass and subjected to external forces and torques , respectively , exhibit a repulsion at large angular separations and an attraction at smaller separations , with the latter resembling the typical behavior for flat interfaces .
this change of character is not observed for quadrupoles , corresponding to free particles on a mechanically isolated droplet .
the analytical results for quadrupoles are compared with the numerical minimization of the surface free energy of the droplet in the presence of ellipsoidal particles . .
And you have already written the first three sentences of the full article: if colloidal particles get trapped at fluid - fluid interfaces they interact effectively via deformations of the interface .
these so - called capillary interactions can easily be tuned by changing external fields and they depend sensitively on the shape of the particles .
this makes them good candidates for designing self - assembling systems and provides a convenient experimental playground for studying basic issues of statistical mechanics in two dimensions in the presence of long - ranged interactions @xcite . on the other hand ,.
Please generate the next two sentences of the article
|
recent experiments @xcite show that capillary forces between elongated particles floating on spherical interfaces can have important consequences for stabilizing so - called pickering emulsions , which are formed by particle - covered droplets ( e.g. , oil ) in a solvent ( e.g. , water ) . whereas considerable theoretical progress has been made in understanding capillary interactions at flat interfaces @xcite ,
basic issues such as the balance of forces acting on the interface and the influence of the incompressibility of the liquid enclosed by spherical interfaces have not yet been fully resolved .
|
12,289 |
Suppose that you have an abstract for a scientific paper: we study chemically driven running droplets on a partially wetting solid substrate by means of coupled evolution equations for the thickness profile of the droplets and the density profile of an adsorbate layer .
two models are introduced corresponding to two qualitatively different types of experiments described in the literature . in both cases
an adsorption or desorption reaction underneath the droplets induces a wettability gradient on the substrate and provides the driving force for droplet motion .
the difference lies in the behavior of the substrate behind the droplet . in case i the substrate
is irreversibly changed whereas in case ii it recovers allowing for a periodic droplet movement ( as long as the overall system stays far away from equilibrium ) .
both models allow for a non - saturated and a saturated regime of droplet movement depending on the ratio of the viscous and reactive time scales .
in contrast to model i , model ii allows for sitting drops at high reaction rate and zero diffusion along the substrate .
the transition from running to sitting drops in model ii occurs via a super- or subcritical drift - pitchfork bifurcation and may be strongly hysteretic implying a coexistence region of running and sitting drops . .
And you have already written the first three sentences of the full article: [ intro ] the movement of droplets in external gradients fascinates scientists and layman alike at least since newton s description @xcite of hauksbee s experiment with drops of orange oil that move between two non - parallel glass plates towards the point of smallest plate distance @xcite . in another example
a drop of liquid freely immersed in another liquid subject to a temperature gradient will move towards the higher temperature region due to marangoni forces caused by surface tension gradients @xcite .
a drop sitting on a solid substrate also moves in a temperature @xcite or wettability @xcite gradient ..
Please generate the next two sentences of the article
|
especially the marangoni force is already used to manipulate droplets , for example in light induced drop movement @xcite .
similar concepts of a directed movement of small amounts of soft matter in a given gradient are also realized in models of cell motility @xcite
|
12,290 |
Suppose that you have an abstract for a scientific paper: it is well known that standard one - dimensional brownian motion @xmath0 has no isolated zeros almost surely .
we show that for any @xmath1 there are @xmath2-hlder continuous functions @xmath3 for which the process @xmath4 has isolated zeros with positive probability .
we also prove that for any continuous function @xmath3 , the zero set of @xmath4 has hausdorff dimension at least @xmath5 with positive probability , and @xmath5 is an upper bound on the hausdorff dimension if @xmath3 is @xmath5-hlder continuous or of bounded variation . .
And you have already written the first three sentences of the full article: let @xmath6 be standard one - dimensional brownian motion and @xmath7 a continuous function defined on some interval @xmath8 .
a standard result is that the zero set of @xmath6 has no isolated points almost surely , see theorem 2.28 in @xcite . by the cameron - martin theorem ( see theorem 1.38 in @xcite or theorem 2.2 in chapter 8 in @xcite ) the zero set of the process @xmath4 has no isolated points almost surely if @xmath3 is in the cameron - martin space @xmath9 ( integrals of functions in @xmath10 ) .
we will prove that the same is true for any function @xmath3 which is @xmath5-hlder continuous ..
Please generate the next two sentences of the article
|
since all functions in @xmath9 are @xmath5-hlder continuous , this is a stronger statement than the one implied by the cameron - martin theorem . for any function @xmath11 defined on some subset ( or the whole ) of @xmath12 denote by @xmath13 the set of zeros of @xmath11 in @xmath14 .
we remove the origin from consideration since the origin is an isolated zero of the process @xmath4 for any @xmath3 growing fast enough in the neighborhood of the origin , say @xmath15 .
|
12,291 |
Suppose that you have an abstract for a scientific paper: the magnetic eden model ( mem ) [ n. vandewalle et al . , phys .
rev .
e. * 50 * , r635 ( 1994 ) ] with ferromagnetic interactions between nearest - neighbor spins is studied in @xmath0dimensional rectangular geometries for @xmath1 . in the mem ,
magnetic clusters are grown by adding spins at the boundaries of the clusters .
the orientation of the added spins depends on both the energetic interaction with already deposited spins and the temperature , through a boltzmann factor .
a numerical monte carlo investigation of the mem has been performed and the results of the simulations have been analyzed using finite - size scaling arguments . as in the case of the ising model , the mem in @xmath2 is non - critical ( only exhibits an ordered phase at @xmath3 ) . in @xmath4
the mem exhibits an order - disorder transition of second - order at a finite temperature .
such transition has been characterized in detail and the relevant critical exponents have been determined .
these exponents are in agreement ( within error bars ) with those of the ising model in 2 dimensions . further similarities between both models have been found by evaluating the probability distribution of the order parameter , the magnetization and the susceptibility .
results obtained by means of extensive computer simulations allow us to put forward a conjecture which establishes a nontrivial correspondence between the mem for the irreversible growth of spins and the equilibrium ising model .
this conjecture is certainly a theoretical challenge and its confirmation will contribute to the development of a framework for the study of irreversible growth processes .
.5 cm .5 cm 21truecm 15truecm .
And you have already written the first three sentences of the full article: the study of kinetic growth models such as directed percolation , eden growth , ballistic deposition , diffusion limited aggregation , random deposition with and without relaxation , cluster - cluster aggregation , etc .
, is motivated by their interest in many areas of scientific research and technology such as polymer science , crystal and polycrystalline growth , gelation , fracture propagation , epidemic spreading , bacterial and fungi growth colonies , colloids , etc . @xcite . within this context the eden model @xcite
has become an archetype growth model ..
Please generate the next two sentences of the article
|
eden clusters are compact but the self - affinity that characterizes the behavior of the growing interface is of much interest ( see e.g. @xcite ) .
few years ago ausloos et al .
|
12,292 |
Suppose that you have an abstract for a scientific paper: we study the @xmath0 three - dimensional ising model with a longitudinal anisotropic bond randomness on the simple cubic lattice . the random exchange interaction is applied only in the @xmath1 direction , whereas in the other two directions , @xmath2 - planes
, we consider ferromagnetic exchange . by implementing an effective parallel tempering scheme
, we outline the phase diagram of the model and compare it to the corresponding isotropic one , as well as to a previously studied anisotropic ( transverse ) case .
we present a detailed finite - size scaling analysis of the ferromagnetic - paramagnetic and spin glass - paramagnetic transition lines , and we also discuss the ferromagnetic - spin glass transition regime .
we conclude that the present model shares the same universality classes with the isotropic model , but at the symmetric point has a considerably higher transition temperature from the spin - glass state to the paramagnetic phase . our data for
the ferromagnetic - spin glass transition line are supporting a forward behavior in contrast to the reentrant behavior of the isotropic model . .
And you have already written the first three sentences of the full article: ising spin - glass models yield phase diagrams with distinctively complex ordered phases in three - dimensions ( @xmath3 ) .
the global phase diagram of such models includes ferromagnetic , paramagnetic , and glassy phases , and the transitions among these are of second order , belonging to different universality classes .
an important part of the corresponding theoretic and computational studies is based on the edwards - anderson ( ea ) model @xcite ..
Please generate the next two sentences of the article
|
the ea model is defined via the hamiltonian @xmath4 where the summation is over nearest - neighbors , @xmath5 are ising spins , and @xmath6 denotes the quenched uncorrelated exchange interaction , obtained in the current work from the following and most popular random bimodal distribution @xmath7 in the present paper , we consider a bimodal spin - glass model with a spatially longitudinal anisotropic bond randomness on the simple cubic lattice .
the random exchange is applied only in the @xmath1 direction , whereas in the @xmath2 - planes , the exchange is taken to be ferromagnetic . thus the disorder is longitudinal and the interactions in the @xmath2 directions are ferromagnetic .
|
12,293 |
Suppose that you have an abstract for a scientific paper: the spectral variability of active galactic nuclei ( agn ) is one of their key features that enables us to study in more details the structure of agn emitting regions .
especially , the broad line profiles , that vary both in flux and shape , give us invaluable information about the kinematics and geometry of the broad line region ( blr ) where these lines are originating from .
we give here a comparative review of the line shape variability in a sample of five type 1 agn , those with broad emission lines in their spectra , of the data obtained from the international long - term optical monitoring campaign coordinated by the special astrophysical observatory of the russian academy of science .
the main aim of this campaign is to study the physics and kinematics of the blr on a uniform data set , focusing on the problems of the photoionization heating of the blr and its geometry , where in this paper we give for a first time a comparative analysis of the variabilty of five type 1 agn , discussing their complex blr physics and geometry in the framework of the estimates of the supermassive black hole mass in agn .
galaxies : active - galaxies quasar : individual ( arp 102b , 3c 390.3 , ngc 5548 , ngc 4151 , ark 564 ) line : profiles .
And you have already written the first three sentences of the full article: in spite of decades of intensive investigations , the broad line region ( blr ) of active galactic nuclei ( agn ) is yet not fully understood .
the direct detection of the blr remains a challenge for modern instruments , since the angular size of the blr is less than @xmath0 even for the closest agns .
the only information from the blr comes in the form of the broad emission lines ( bel ) , that are a very prominent feature in the spectra of the so - called type 1 agn @xcite ..
Please generate the next two sentences of the article
|
nevertheless , the investigations of the bel s properties ( flux and shape ) , and especially of their variability , indicates that the blr is linked with the accretion process onto the supermassive black hole in the center of an agn .
first of all , the blr gas is photoionized by the continuum radiation from the accretion disk , and secondly , at least part of the blr follows its geometry , i.e. even though the blr geometry is not ubiquitously described it is believed that one part of the blr is a part of the accretion disk or has a disk - like geometry @xcite .
|
12,294 |
Suppose that you have an abstract for a scientific paper: full - dimensional semiclassical dynamical calculations are reported for the photofragmentation of isocyanic acid in the s@xmath0 state .
these calculations , performed for the first time , allow to closely reproduce the key features of high - resolution imaging measurements at photolysis wavelengths of 201 and 210 nm while providing insight into the underlying dissociation mechanism .
isocyanic acid , hnco , is the simplest molecule that contains h , c , n and o atoms , which are essential for life and major constituents of chemical species in chemistry and biology . since its discovery in 1830 @xcite
, hnco has been identified in diverse media .
for instance , this molecule is found in over sixty galactic sources and in nine external galaxies @xcite .
it is relatively highly abundant and it is suggested to be strongly involved in prebiotic chemistry occurring there .
especially , it is a major component of the photochemistry of building blocks of life ( dna bases and amino acids ) .
isocyanic acid has been identified in the atmosphere @xcite where hnco sources are from both anthropogenic and biomass burning , and also released from combustion ( e.g. fuels , cigarettes @xcite ) .
it is known to be toxic and easily dissolves in water ( in lungs ) posing obvious health risks such as the development of atherosclerosis , cataracts and rheumatoid arthritis @xcite and inflammations that can lead to cardiovascular disease . to - date
, the health effects of isocyanic acid , its role in the atmosphere and its photochemistry are not fully known nor understood .
the photochemistry of hnco under uv radiations or in combustion sources is complex . besides the importance of isocyanic acid in diverse fields ( see above ) , its unimolecular decomposition processes represent benchmarks for tetratomic molecules evolution upon electronic excitation .
adiabatically , the lowest hnco singlet electronic states can not lead to the formation of nh ( x@xmath1 ) + co(x@xmath2 ) products . instead ,....
And you have already written the first three sentences of the full article: j. liebig and f. whler , ann .
phys . * 96 * , 369 ( 1830 ) .
n. marcelino , s. brnken , j. cernicharo , d. quan , e. roueff , e. herbst , and p. thaddeus , a&a * 516 * , a105 ( 2010 ) ..
Please generate the next two sentences of the article
|
r. a. perry and d. l. siebers , nature * 324 * , 657 ( 1986 ) .
j. a. miller and c. t. bowman , int . j.
|
12,295 |
Suppose that you have an abstract for a scientific paper: results of optical frequency transfer over a carrier - grade dense - wavelength - division - multiplexing ( dwdm ) optical fibre network are presented .
the relation between soil temperature changes on a buried optical fibre and frequency changes of an optical carrier through the fibre is modelled .
soil temperatures , measured at various depths by the royal netherlands meteorology institute ( knmi ) are compared with observed frequency variations through this model .
a comparison of a nine - day record of optical frequency measurements through the @xmath0 km fibre link with soil temperature data shows qualitative agreement .
a soil temperature model is used to predict the link stability over longer periods ( days - months - years ) .
we show that one - way optical frequency dissemination is sufficiently stable to distribute and compare e.g. rubidium frequency standards over standard dwdm optical fibre networks . .
And you have already written the first three sentences of the full article: in recent years , fibre - optic connections in telecommunication networks have proven to be suitable for frequency comparisons and frequency distribution with high stability over long distances . in general the frequency of either an ultra - stable continuous - wave ( cw ) laser or a stable microwave reference
is transmitted over an optical fibre and received at the remote site .
several experiments @xcite have shown that frequency comparisons at or below the current accuracy level of the best atomic frequency references , a few times 10@xmath1 @xcite , are feasible over long - haul fibre connections ..
Please generate the next two sentences of the article
|
for example , the optical frequency of the 1s-2s transition in atomic hydrogen was recently measured with respect to a remote cs frequency standard with 4.5@xmath2 relative uncertainty , employing a 920 km long fibre - optic link performing at the @xmath3 uncertainty level @xcite .
fibre - optic methods for remote frequency comparison can provide significantly better stability than current satellite - based methods . these include two - way satellite time and frequency transfer ( twstft ) @xcite and ( carrier - phase ) common - view global positioning system ( ( cp/)cv - gps ) comparisons @xcite .
|
12,296 |
Suppose that you have an abstract for a scientific paper: as supernova remnants expand , their shock waves are freezing in and compressing the magnetic field lines they encounter ; consequently we can use supernova remnants as magnifying glasses for their ambient magnetic fields .
we will describe a simple model to determine emission , polarization , and rotation measure characteristics of adiabatically expanding supernova remnants and how we can exploit this model to gain information about the large scale magnetic field in our galaxy .
we will give two examples : the snr da530 , which is located high above the galactic plane , reveals information about the magnetic field in the halo of our galaxy .
the snr g182.4 + 4.3 is located close to the anti - centre of our galaxy and reveals the most probable direction where the large - scale magnetic field is perpendicular to the line of sight .
this may help to decide on the large - scale magnetic field configuration of our galaxy . .
And you have already written the first three sentences of the full article: recently , there have been several studies of the milky way s magnetic field by the means of observing the rotation measure of compact polarized objects like extra - galactic point sources ( e.g. @xcite ) or pulsars ( see talks by a. noutsos and j .- l .
however , we still do not know the large - scale magnetic field configuration or even the number of field reversals within our galaxy .
one problem is that through faraday rotation studies of extra - galactic point sources we only derive the average magnetic field parallel to the line of sight @xmath0 through our galaxy weighted by the electron density @xmath1 , because the rotation measure @xmath2 is given by : @xmath3 here @xmath2 is given in rad / m@xmath4 , @xmath5 in @xmath6 g , @xmath1 in @xmath7 , and the pathlength @xmath8 in pc ..
Please generate the next two sentences of the article
|
in addition extragalactic sources may suffer from intrinsic faraday rotation of unknown magnitude .
faraday rotation studies of pulsars average @xmath0 between us and the pulsar weighted by @xmath1 .
|
12,297 |
Suppose that you have an abstract for a scientific paper: we present a 50ks _ chandra _ acis - i x - ray observation of the @xcite vla archival field .
the observations reach a limiting sensitivity of @xmath0 counts s@xmath1 , corresponding to a flux of a few times @xmath2erg s@xmath1 @xmath3 for the models we explore
. the _ chandra _
observations were undertaken to search for x - ray counterparts to the eight transient sources without optical counterparts , and the two transient sources with optical counterparts seen by @xcite neither of the sources with optical counterparts was detected in x - rays .
one of the eight optical non - detections is associated with a marginal ( @xmath4 ) x - ray detection in our _ chandra _ image . a second optically - undetected @xcite transient
may be associated with a @xmath5 x - ray detected quasar or its host galaxy , or alternatively is undetected in x - rays and is a chance association with the nearby x - ray source .
the x - ray flux upper limits , and the one marginal detection , are consistent with the interpretation of @xcite that the optically - undetected radio transients are flares from isolated old galactic neutron stars .
the marginal x - ray detection has a hardness ratio which implies a temperature too high for a simple one - temperature neutron star model , but plausible multi - component fits are not excluded , and in any case the marginal x - ray detection may be due to cosmic rays or particle background .
the x - ray flux upper limits are also consistent with flare star progenitors at @xmath6kpc ( which would require the radio luminosity of the transient to be unusually high for such an object ) or less extreme flares from brown dwarfs at distances of around 100pc . .
And you have already written the first three sentences of the full article: in recent years , authors such as @xcite , hereafter b07 ; @xcite ; @xcite ; @xcite ; @xcite ; and others , have made use of archival data ( observations of calibration fields , or in some cases , entire telescope archives ) to search for radio transients .
other studies have targeted particular fields with observations dedicated to the search for transients ( * ? ? ? * and references therein ) .
such studies are preparing the groundwork for a new generation of high - throughput radio telescopes : both dedicated new observatories for example , the allen telescope array @xcite , lofar @xcite , and askap @xcite and upgrades to older instruments for example , apertif @xcite and evla @xcite ..
Please generate the next two sentences of the article
|
a major goal for these new facilities is to survey large areas of sky at high sensitivity , both to build up deep , wide - field images , and to search for transient and variable sources from a range of progenitors @xcite .
currently , large areas of rate versus sensitivity parameter space remain to be explored @xcite , and the radio transient population is not well understood . in observations where radio transients are detected , sometimes counterparts are seen in existing surveys at other wavelengths .
|
12,298 |
Suppose that you have an abstract for a scientific paper: the fermi motion effect in @xmath0 production in various hadron colliders is studied .
we deduce that in agreement with sum rules which the fragmentation functions should satisfy , while the effect has considerable influence on the fragmentation probabilities and the differential cross sections , the total cross sections are essentially left unchanged . .
And you have already written the first three sentences of the full article: the @xmath0 state has been one of the interesting problems of qcd both in theory [ 1,2,3 ] and in experiment [ 4 ] .
qcd predictions for production cross section of @xmath0 fails to agree with the experimental results .
color octet senario is introduced to bring about the agreement [ 5,6 ] . in this work ,.
Please generate the next two sentences of the article
|
we introduce the fermi motion into the @xmath0 production .
we only include the charm fragmentation contributions .
|
12,299 |
Suppose that you have an abstract for a scientific paper: g. czdli and e.t . schmidt introduced in 2012 the fork extension . continuing from part i
, we investigate the congruences of a fork extension . .
And you have already written the first three sentences of the full article: ] let @xmath0 be a slim , planar , semimodular lattice , an _ sps lattice_. as in g. czdli and e.t .
schmidt @xcite , _ inserting a fork _ to @xmath0 at the covering square @xmath1 , firstly , replaces @xmath1 by a copy of @xmath2 ( see the lattice @xmath2 in figure [ f : s7 ] ) . secondly ,
if there is a chain @xmath3 such that the element @xmath4 has just been added and @xmath5 is a covering square in the lattice @xmath0 ( and so @xmath6 is not on the boundary of @xmath0 ) but @xmath7 at the present stage of the construction , then we insert a new element @xmath8 such that @xmath9 and @xmath10 ..
Please generate the next two sentences of the article
|
let @xmath11 $ ] denote the lattice we obtain when the procedure terminates .
we say that @xmath11 $ ] is obtained from @xmath0 by _ inserting a fork to @xmath0 _ at the covering square @xmath1 .
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.