pinecone/core-2020-05-10-deduplication huggingface dataset:
Regular singular Sturm-Liouville operators and their zeta-determinants

We consider Sturm-Liouville operators on the line segment [0, 1] with general
regular singular potentials and separated boundary conditions. We establish
existence and a formula for the associated zeta-determinant in terms of the
Wronski- determinant of a fundamental system of solutions adapted to the
boundary conditions. This generalizes the earlier work of the first author,
treating general regular singular potentials but only the Dirichlet boundary
conditions at the singular end, and the recent results by Kirsten-Loya-Park for
general separated boundary conditions but only special regular singular
potentials.Comment: 38 pages, 2 figures; Completely revised according to the referees
  comprehensive suggestions; v3: minor corrections, accepted for publication in
  Journal of Functional Analysi
On Lundh's percolation difussion

A collection of spherical obstacles in the ball in Euclidean space is said to
be avoidable for Brownian motion if there is a positive probability that
Brownian motion diffusing from some point in the ball will avoid all the
obstacles and reach the boundary of the ball. The centres of the spherical
obstacles are generated according to a Poisson point process while the radius
of an obstacle is a deterministic function depending only on the distance from
the obstacle's centre to the centre of the ball. Lundh has given the name
percolation diffusion to this process if avoidable configurations are generated
with positive probability. An integral condition for percolation diffusion is
derived in terms of the intensity of the Poisson point process and the function
that determines the radii of the obstacles
Monte Carlo Study of the Finite Size Effects on the Magnetization of
  Maghemite Small Particles

Monte Carlo simulations of a model for $\gamma$-Fe$_2$O$_3$ (maghemite)
single particle of spherical shape are presented aiming at the elucidation the
specific role played by the finite size and the surface on the anomalous
magnetic behaviour observed in small particle systems at low temperature. The
influence of the finite-size effects on the equilibrium properties of extensive
magnitudes, field coolings and hysteresis loops is studied an compared to the
results for periodic boundaries. It is shown that for the smallest sizes the
thermal demagnetization of the surface completely dominates the magnetization
while the behaviour of the core is similar to that of the periodic boundary
case, independently of $D$. The change in shape of the hysteresis loops with
$D$ demonstrates that the reversal mode is strongly influenced by the presence
of broken links and disorder at the surface.Comment: Presented at the 8th Joint MMM-Intermag Conference, San Antonio,
  Texas, 7-11 January 2001. Session HF-09. To be published in J. Appl. Phys. 3
  pages, 3 figure
Electronic Raman Scattering and Phonon Self-Energy Effects in the R-123
  System: Signatures of Gap and Pseudogap

Using Raman spectroscopy and transport measurements we investigate thin
epitaxial films of Y{1-x}(Pr,Ca)xBa2Cu3O{6+y}. We explore the electronic Raman
responses obtained after subtraction of phononic excitations, and the 2Delta
peaks that form out of the electronic background below Tc. We find that the
energy of the B1g 2Delta peak increases monotonically with decreasing doping
until the peaks become unresolvable. In contrast, the peaks in A1g symmetry
follow Tc being resolvable in the Pr-doped films. The B2g responses are weak
and a 2Delta peak is only detected at the highest doping level. As a
consequence of strong electron-phonon coupling, the B1g phonon at 340 cm^-1
exhibits a pronounced Fano-type line shape. We use a phenomenological model to
describe the line shape that takes into account real and imaginary part of the
electronic response. It allows us to obtain the self-energy corrections and the
mass- enhancement factor lambda as a measure of the coupling. In the normal
state we find lambda=0.015 around optimal doping and decreasing values with
decreasing doping. The electron-phonon coupling increases strongly below T_c in
overdoped samples in which the B1g 2Delta peaks appear in the vicinity of the
phonon. Self-energy effects observed in the superconducting state can only
partly be assigned to the redistributing electronic response. Anomalies with
respect to frequency, linewidth, and intensity remain. They appear at
increasing tempera- tures with decreasing doping and we provide evidence that
they are connected to the presence of the pseudogap. We supplement our study by
a comparison with single crystal data and investigate the influence of
site-substitutional disorder on the electronic response and the electron-phonon
interaction.Comment: 46 pages including 20 figures, accepted for publication in Annalen
  der Physik to appear August 1999. Figures and PDF-document are available
  under http://www.physnet.uni-hamburg.de/home/vms/bock/annalen.ht
Seasonal Variations of the Effect from Solar Neutrinos in Lithium
  Detector

The presence of two monochromatic lines of approximately equal intensity:
$^{7}$Be- and pep-neutrinos in the sensitivity plot of lithium detector makes
the pattern of the seasonal variations of the effect from solar neutrinos very
characteristic in case if the long-wave vacuum oscillations are realized. This
can give the very high accuracy in the measurement of the parameters of
neutrino oscillations especially if combined with the results obtained by the
detector sensitive mainly to $^{7}$Be-line like BOREXINO or KamLAND.Comment: 8 pages, 6 figures, one more reference adde
The quark - antiquark asymmetry of the strange sea of the nucleon

The strange sea of the proton is generally assumed to have quark - antiquark
symmetry. However it has been known for some time that non-perturbative
processes involving the meson cloud of the proton may break this symmetry.
Recently this has been of interest as it affects the analysis of the so-called
`NuTeV anomaly', and could explain the large discrepancy between the NuTeV
measurement of $\sin^{2} \theta_{W}$ and the currently accepted value. In this
paper we re-examine strange - anti-strange asymmetry using the meson cloud
model. We calculate contributions to the strange sea arising from fluctuations
in the proton wavefunction to states containing either Lambda or Sigma hyperons
together with either Kaons or pseudovector $K^{*}$ mesons. We find that we
should not ignore fluctuations involving $K^{*}$ mesons in this picture. The
strange sea asymmetry is found to be small, and is unlikely to affect the
analysis of the Llewellyn-Smith cross section ratios or the Paschos-Wolfenstein
relationship.Comment: 12 pages, 3 figure
Transverse Activity of Kaons and the Deconfinement Phase Transition in
  Nucleus--Nucleus Collisions

We found that the experimental results on transverse mass spectra of kaons
produced in central Pb+Pb (Au+Au) interactions show an anomalous dependence on
the collision energy. The inverse slopes of the spectra increase with energy in
the low (AGS) and high (RHIC) energy domains, whereas they are constant in the
intermediate (SPS) energy range. We argue that this anomaly is probably caused
by a modification of the equation of state in the transition region between
confined and deconfined matter. This observation may be considered as a new
signal, in addition to the previously reported anomalies in the pion and
strangeness production, of the onset of deconfinement located in the low SPS
energy domain.Comment: 7 pages, 2 figure
Comparison of the Gottfried and Adler sum rules within the large-Nc
  expansion

The Adler sum rule for deep inelastic neutrino scattering measures the
isospin of the nucleon and is hence exact. By contrast, the corresponding
Gottfried sum rule for charged lepton scattering was based merely on a valence
picture and is modified both by perturbative and non-perturbative effects.
Noting that the known perturbative corrections to two-loop order are suppressed
by a factor 1/N_c^2, relative to those for higher moments, we propose that this
suppression persists at higher orders and also applies to higher-twist effects.
Moreover, we propose that the differences between the corresponding radiative
corrections to higher non-singlet moments in charged-lepton and neutrino deep
inelastic scattering are suppressed by 1/N_c^2, in all orders of perturbation
theory. For the first moment, in the Gottfried sum rule, the substantial
discrepancy between the measured value and the valence-model expectation may be
attributed to an intrinsic isospin asymmetry in the nucleon sea, as is indeed
the case in a chiral-soliton model, where the discrepancy persists in the limit
N_c-->infinity.Comment: 12 pages. Note added in proof, additional reference
Up to four planets around the M dwarf GJ 163. Sensitivity of Bayesian
  planet detection criteria to prior choice

Exoplanet Doppler surveys are currently the most efficient means to detect
low-mass companions to nearby stars. Among these stars, the light M dwarfs
provide the highest sensitivity to detect low-mass exoplanet candidates.
Evidence is accumulating that a substantial fraction of these low-mass planets
are found in high-multiplicity planetary systems. GJ 163 is a nearby inactive M
dwarf with abundant public observations obtained using the HARPS spectrograph.
We obtain and analyse radial velocities from the HARPS public spectra of GJ 163
and investigate the presence of a planetary companions orbiting it. The number
of planet candidates detected might depend on some prior assumptions. Since the
impact of prior choice has not been investigated throughly previously, we study
the effects of different prior densities on the detectability of planet
candidates around GJ 163. We use Bayesian tools, i.e. posterior samplings and
model comparisons, when analysing the GJ 163 velocities. We consider models
accounting for the possible correlations of subsequent measurements. We also
search for activity-related counterparts of the signals we observe and test the
dynamical stability of the planetary systems corresponding to our solutions
using direct numerical integrations of the orbits. We find that there are at
least three planet candidates orbiting GJ 163. The existence of a fourth planet
is supported by the data but the evidence in favor of the corresponding model
is not yet conclusive. The second innermost planet candidate in the system with
an orbital period of 25.6 days and a minimum mass of 8.7 Me is inside the
liquid-water habitable zone of the star.Comment: 13 pages, 11 Figures, to appear in A&
New evolutionary sequences for extremely low mass white dwarfs:
  Homogeneous mass and age determinations, and asteroseismic prospects

We provide a fine and homogeneous grid of evolutionary sequences for He-core
white dwarfs with masses 0.15-0.45 Msun, including the mass range for ELM white
dwarfs (<0.20Msun). The grid is appropriate for mass and age determination, and
to study their pulsational properties. White dwarf sequences have been computed
by performing full evolutionary calculations that consider the main energy
sources and processes of chemical abundance changes during white dwarf
evolution. Initial models for the evolving white dwarfs have been obtained by
computing the non-conservative evolution of a binary system consisting of a
Msun ZAMS star and a 1.4 Msun neutron star for various initial orbital periods.
To derive cooling ages and masses for He-core white dwarf we perform a least
square fitting of the M(Teff, g) and Age(Teff, g) relations provided by our
sequences by using a scheme that takes into account the time spent by models in
different regions of the Teff-g plane. This is useful when multiple solutions
for cooling age and mass determinations are possible in the case of
CNO-flashing sequences. We also explore the adiabatic pulsational properties of
models near the critical mass for the development of CNO flashes (~0.2 Msun).
This is motivated by the discovery of pulsating white dwarfs with stellar
masses near this threshold value. We obtain reliable and homogeneous mass and
cooling age determinations for 58 very low-mass white dwarfs, including 3
pulsating stars. Also, we find substantial differences in the period spacing
distributions of g-modes for models with stellar masses ~ 0.2 Msun, which could
be used as a seismic tool to distinguish stars that have undergone CNO flashes
in their early cooling phase from those that have not. Finally, for an easy
application of our results, we provide a reduced grid of values useful to
obtain masses and ages of He-core white dwarf.Comment: 12 pages, 9 figures, to be published in Astronomy and Astrophysic
Shadow multiplets and superHiggs mechanism

We discuss a general feature of Freund Rubin compactifications that was
previously overlooked. It consist in a curious pairing, which we call a shadow
relation, of completely different (in terms of spin and mass) fields of the
dimensionally reduced theory. Particularly interesting is the case where the
compactification preserves a certain amount of supersymmetry, giving rise to a
shadowing phenomenon between whole supermultiplets of fields. In particular,
there are strong suggestions about the consistency of a massive truncation of
11D supergravity to the massless modes of the graviton supermultiplet plus the
massive modes of its shadow partner. This fact has important consequences in
the ${\cal N}=2$ and ${\cal N}=3$ cases, which seem to realize respectively a
Higgs or a superHiggs phenomenon. In other words, we are led to reinterpret the
dimensionally reduced theory as a spontaneously broken phase of some higher
(super)symmetric theory.Comment: 10 pages, latex. To appear in the proceedings of the RTN conference
  ``The Quantum Structure of Spacetime and the Geometric Nature of Fundamental
  Interactions'' (Berlin, October 2000
Matrix string partition function

We evaluate quasiclassically the Ramond partition function of Euclidean D=10 U(N) super Yang-Mills theory reduced to a two-dimensional torus. The result can be interpreted in terms of free strings wrapping the space-time torus, as expected from the point of view of Matrix string theory. We demonstrate that, when extrapolated to the ultraviolet limit (small area of the torus), the quasiclassical expressions reproduce exactly the recently obtained expression for the partition of the completely reduced SYM theory, including the overall numerical factor. This is an evidence that our quasiclassical calculation might be exact
AdS_6/CFT_5 correpondence for F(4) Supergravity

F(4) supergravity, the gauge theory of the exceptional six-dimensional Anti-de Sitter superalgebra, is coupled to an arbitrary number of vector multiplets whose scalar components parametrize the quaternionic manifold SO(4,n)/SO(4)\times SO(n). By gauging the compact subgroup SU(2)_d \otimes G, where SU(2)_d is the diagonal subgroup of SO(4)= SU(2)_L\otimes SU(2)_R (the R-symmetry group of six-dimensional Poincare' supergravity) and G is a compact group such that dim G = n. The potential admits an AdS background for g=3m, as the pure F(4)-supergravity. The boundary F(4) superconformal fields are realized in terms of a singleton superfield (hypermultiplet) in harmonic superspace with flag manifold SU(2)/U(1)=S^2. We analize the spectrum of short representations in terms of superconformal primaries and predict general features of the K-K specrum of massive type IIA supergravity compactified on warped AdS_6\otimes S^4
A Note on the Green - Schwarz Mechanism in Open - String Theories

An interesting feature of some open superstring models in $D < 10$ is the
simultaneous presence, in the spectrum, of gauge fields and of a number of
antisymmetric tensor fields. In these cases the Green-Schwarz mechanism can
(and does) take a generalized form, resulting from the combined action of all
the antisymmetric tensors. These novelties are illustrated referring to some
simple rational models in six dimensions, and some of their implications for
the low-energy effective field theory are pointed out.Comment: 13 pages, phyzz
Strings and black holes

I review some recent work (done in collaboration with G. Veneziano) which
clarifies the existence of a correspondence between self-gravitating
fundamental string states and Schwarzschild black holes. The main result is a
detailed calculation showing that self-gravity causes a typical string state of
mass M to shrink, as the string coupling g^2 increases, down to a compact
string state whose mass, size, entropy and luminosity match (for the critical
value g_c^2 = (M sqrt{alpha'})^{-1}) those of a Schwarzschild black hole. This
confirms the idea that the entropy of black holes can be accounted for by
counting string states, and suggests that the level spacing of the quantum
states of Schwarzschild black holes is exponentially small, and very much
blurred by radiative effects.Comment: 12 pages, uses annalen.cls, contribution to the proceedings of the
  "Journees Relativistes 99" (Weimar, Sept 1999
Quantile motion of electromagnetic waves in wave guides of varying cross
  section and dispersive media

We discuss applications of the quantile concept of trajectories and
velocities to the propagation of electromagnetic signals in wave guides of
varying cross section. Quantile motion is a general description of the
transport properties of measurable conserved quantities in quantum mechanics as
well as in classical electrodynamics. In the latter case we consider the
quantile motion of electromagnetic energy as the direct result of a physical
measurement. In this sense the quantile velocity corresponds to the
electromagnetic signal velocity also in the presence of barriers and
inhomogeneities in the medium of propagation. We show that this signal velocity
is always smaller than the speed of light in vacuum. Using numerical examples
we demonstrate how typical wave phenomena can be described in terms of the
quantile motion.Comment: 12 pages, LaTeX, revtex, 10 postscript figures. Talk given in the
  workshop "Superluminal(?) Velocities", Cologne, June 6-10, 1998, submitted to
  Annalen der Physi
Stable clustering, the halo model and non-linear cosmological power spectra

We present the results of a large library of cosmological N-body simulations, using power-law initial spectra. The non-linear evolution of the matter power spectra is compared with the predictions of existing analytic scaling formulae based on the work of Hamilton et al. The scaling approach has assumed that highly non-linear structures obey ‘stable clustering’ and are frozen in proper coordinates. Our results show that, when transformed under the self-similarity scaling, the scale-free spectra define a non-linear locus that is clearly shallower than would be required under stable clustering. Furthermore, the small-scale non-linear power increases as both the power spectrum index n and the density parameter Ω decrease, and this evolution is not well accounted for by the previous scaling formulae. This breakdown of stable clustering can be understood as resulting from the modification of dark matter haloes by continuing mergers. These effects are naturally included in the analytic ‘halo model’ for non-linear structure; we use this approach to fit both our scale-free results and also our previous cold dark matter data. This method is more accurate than the commonly used Peacock–Dodds formula and should be applicable to more general power spectra
Tensor Hierarchy and Generalized Cartan Calculus in SL(3)$\times$SL(2)
  Exceptional Field Theory

We construct exceptional field theory for the duality group
SL(3)$\times$SL(2). The theory is defined on a space with 8 `external'
coordinates and 6 `internal' coordinates in the $(3,2)$ fundamental
representation, leading to a 14-dimensional generalized spacetime. The bosonic
theory is uniquely determined by gauge invariance under generalized external
and internal diffeomorphisms. The latter invariance can be made manifest by
introducing higher form gauge fields and a so-called tensor hierarchy, which we
systematically develop to much higher degree than in previous studies. To this
end we introduce a novel Cartan-like tensor calculus based on a covariant
nil-potent differential, generalizing the exterior derivative of conventional
differential geometry. The theory encodes the full $D=11$ or type IIB
supergravity, respectively.Comment: 49 page
A Higher Frobenius-Schur Indicator Formula for Group-Theoretical Fusion
  Categories

Group-theoretical fusion categories are defined by data concerning finite
groups and their cohomology: A finite group $G$ endowed with a three-cocycle
$\omega$, and a subgroup $H\subset G$ endowed with a two-cochain whose
coboundary is the restriction of $\omega$.
  The objects of the category are $G$-graded vector spaces with suitably
twisted $H$-actions; the associativity of tensor products is controlled by
$\omega$. Simple objects are parametrized in terms of projective
representations of finite groups, namely of the stabilizers in $H$ of right
$H$-cosets in $G$, with respect to two-cocycles defined by the initial data.
  We derive and study general formulas that express the higher Frobenius-Schur
indicators of simple objects in a group-theoretical fusion category in terms of
the group-theoretical and cohomological data defining the category and
describing its simples.Comment: 21 page
Long-range pseudorapidity dihadron correlations in $d$+Au collisions at
  $\sqrt{s_{\rm NN}}=200$ GeV

Dihadron angular correlations in $d$+Au collisions at $\sqrt{s_{\rm NN}}=200$
GeV are reported as a function of the measured zero-degree calorimeter neutral
energy and the forward charged hadron multiplicity in the Au-beam direction. A
finite correlated yield is observed at large relative pseudorapidity
($\Delta\eta$) on the near side (i.e. relative azimuth $\Delta\phi\sim0$). This
correlated yield as a function of $\Delta\eta$ appears to scale with the
dominant, primarily jet-related, away-side ($\Delta\phi\sim\pi$) yield. The
Fourier coefficients of the $\Delta\phi$ correlation, $V_{n}=\langle\cos
n\Delta\phi\rangle$, have a strong $\Delta\eta$ dependence. In addition, it is
found that $V_{1}$ is approximately inversely proportional to the mid-rapidity
event multiplicity, while $V_{2}$ is independent of it with similar magnitude
in the forward ($d$-going) and backward (Au-going) directions.Comment: 8 pages, 4 figure
Static pure Lovelock black hole solutions with horizon topology ${\bf
  S^{(n)} \times S^{(n)}}$

It is well known that vacuum equation of arbitrary Lovelock order for static
spacetime ultimately reduces to a single algebraic equation, we show that the
same continues to hold true for pure Lovelock gravity of arbitrary order $N$
for topology ${\bf S^{(n)} \times S^{(n)}}$. We thus obtain pure Lovelock
static black hole solutions with two-sphere topology for any order $N$, and in
particular we study in full detail the third and fourth order Lovelock black
holes. It is remarkable that thermodynamical stability of black hole discerns
between odd and even $N$, and consequently between negative and positive
$\Lambda$ and it favours the former while rejecting the latter.Comment: 21 pages. Matches JHEP published versio