title:
Relativistic Radiation Magnetohydrodynamics in Dynamical Spacetimes:
  Numerical Methods and Tests

abstract:
  Many systems of current interest in relativistic astrophysics require a
knowledge of radiative transfer in a magnetized gas flowing in a
strongly-curved, dynamical spacetime. Such systems include coalescing compact
binaries containing neutron stars or white dwarfs, disks around merging black
holes, core collapse supernovae, collapsars, and gamma-ray burst sources. To
model these phenomena, all of which involve general relativity, radiation
(photon and/or neutrino), and magnetohydrodynamics, we have developed a general
relativistic code capable of evolving MHD fluids and radiation in dynamical
spacetimes. Our code solves the coupled Einstein-Maxwell-MHD-Radiation system
of equations both in axisymmetry and in full 3+1 dimensions. We evolve the
metric by integrating the BSSN equations, and use a conservative,
high-resolution shock-capturing scheme to evolve both the MHD and radiation
moment equations. In this paper, we implement our scheme for optically thick
gases and grey-body opacities. Our code gives accurate results in a suite of
tests involving radiating shocks and nonlinear waves propagating in Minkowski
spacetime. In addition, to test our code's ability to evolve the relativistic
radiation-MHD equations in strong-field dynamical spacetimes, we study "thermal
Oppenheimer-Snyder collapse" to a black hole, and find good agreement between
analytic and numerical solutions.


title:
Antiferromagnetic Order of Strongly Interacting Fermions in a Trap:
  Real-Space Dynamical Mean-Field Analysis

abstract:
  We apply Dynamical Mean-Field Theory to strongly interacting fermions in an
inhomogeneous environment. With the help of this Real-Space Dynamical
Mean-Field Theory (R-DMFT) we investigate antiferromagnetic states of
repulsively interacting fermions with spin 1/2 in a harmonic potential. Within
R-DMFT, antiferromagnetic order is found to be stable in spatial regions with
total particle density close to one, but persists also in parts of the system
where the local density significantly deviates from half filling. In systems
with spin imbalance, we find that antiferromagnetism is gradually suppressed
and phase separation emerges beyond a critical value of the spin imbalance.


title: On the Brownian gas: a field theory with a Poissonian ground state

abstract:
  As a first step towards a successful field theory of Brownian particles in
interaction, we study exactly the non-interacting case, its combinatorics and
its non-linear time-reversal symmetry. Even though the particles do not
interact, the field theory contains an interaction term: the vertex is the
hallmark of the original particle nature of the gas and it enforces the
constraint of a strictly positive density field, as opposed to a Gaussian free
field. We compute exactly all the n-point density correlation functions,
determine non-perturbatively the Poissonian nature of the ground state and
emphasize the futility of any coarse-graining assumption for the derivation of
the field theory. We finally verify explicitly, on the n-point functions, the
fluctuation-dissipation theorem implied by the time-reversal symmetry of the
action.

categories: cond-mat.stat-mech hep-th math-ph math.MP


title:
On the distribution of initial masses of stellar clusters inferred from
  synthesis models

abstract:
  The fundamental properties of stellar clusters, such as the age or the total
initial mass in stars, are often inferred from population synthesis models. The
predicted properties are then used to constrain the physical mechanisms
involved in the formation of such clusters in a variety of environments.
Population synthesis models cannot, however, be applied blindy to such systems.
We show that synthesis models cannot be used in the usual straightforward way
to small-mass clusters (say, M < few times 10**4 Mo). The reason is that the
basic hypothesis underlying population synthesis (a fixed proportionality
between the number of stars in the different evolutionary phases) is not
fulfilled in these clusters due to their small number of stars. This incomplete
sampling of the stellar mass function results in a non-gaussian distribution of
the mass-luminosity ratio for clusters that share the same evolutionary
conditions (age, metallicity and initial stellar mass distribution function).
We review some tests that can be carried out a priori to check whether a given
cluster can be analysed with the fully-sampled standard population synthesis
models, or, on the contrary, a probabilistic framework must be used. This leads
to a re-assessment in the estimation of the low-mass tail in the distribution
function of initial masses of stellar clusters.


title: Oxidised cosmic acceleration

abstract:
  We give detailed proofs of several new no-go theorems for constructing flat
four-dimensional accelerating universes from warped dimensional reduction.
These new theorems improve upon previous ones by weakening the energy
conditions, by including time-dependent compactifications, and by treating
accelerated expansion that is not precisely de Sitter. We show that de Sitter
expansion violates the higher-dimensional null energy condition (NEC) if the
compactification manifold M is one-dimensional, if its intrinsic Ricci scalar R
vanishes everywhere, or if R and the warp function satisfy a simple limit
condition. If expansion is not de Sitter, we establish threshold
equation-of-state parameters w below which accelerated expansion must be
transient. Below the threshold w there are bounds on the number of e-foldings
of expansion. If M is one-dimensional or R everywhere vanishing, exceeding the
bound implies the NEC is violated. If R does not vanish everywhere on M,
exceeding the bound implies the strong energy condition (SEC) is violated.
Observationally, the w thresholds indicate that experiments with finite
resolution in w can cleanly discriminate between different models which satisfy
or violate the relevant energy conditions.


title: A Modified TreePM Code

abstract:
  We discuss the performance characteristics of using the modification of the
tree code suggested by Barnes \citep{1990JCoPh..87..161B} in the context of the
TreePM code. The optimisation involves identifying groups of particles and
using only one tree walk to compute force for all the particles in the group.
This modification has been in use in our implementation of the TreePM code for
some time, and has also been used by others in codes that make use of tree
structures. In this paper, we present the first detailed study of the
performance characteristics of this optimisation. We show that the
modification, if tuned properly can speed up the TreePM code by a significant
amount. We also combine this modification with the use of individual time steps
and indicate how to combine these two schemes in an optimal fashion. We find
that the combination is at least a factor of two faster than the modified
TreePM without individual time steps. Overall performance is often faster by a
larger factor, as the scheme of groups optimises use of cache for large
simulations.


title:
Particle acceleration in relativistic collisionless shocks: Fermi
  process at last?

abstract:
  We present evidence that relativistic shocks propagating in unmagnetized
plasmas can self-consistently accelerate particles. We use long-term
two-dimensional particle-in-cell simulations to study the well-developed shock
structure in unmagnetized pair plasma. The particle spectrum downstream of such
a shock consists of two components: a relativistic Maxwellian, with
characteristic temperature set by the upstream kinetic energy of the flow, and
a high-energy tail, extending to energies >100 times that of the thermal peak.
This tail is best fitted as a power law in energy with index -2.4+-0.1,
modified by an exponential cutoff. The cutoff moves to higher energies with
time of the simulation, leaving a larger power law range. The number of
particles in the tail is ~1% of the downstream population, and they carry ~10%
of the kinetic energy in the downstream. Upon investigation of the trajectories
of particles in the tail, we find that the energy gains occur as particles
bounce between the upstream and downstream regions in the magnetic fields
generated by the Weibel instability. We compare this mechanism to the first
order Fermi acceleration, and set a lower limit on the efficiency of shock
acceleration process.


title:
Magnetic field evolution in relativistic unmagnetized collisionless
  shocks

abstract:
  We study relativistic unmagnetized collisionless shocks using unprecedentedly
large particle-in-cell simulations of two-dimensional pair plasma. High energy
particles accelerated by the shock are found to drive magnetic field evolution
on a timescale >10^4 plasma times. Progressively stronger magnetic fields are
generated on larger scales in a growing region around the shock.
Shock-generated magnetic fields and accelerated particles carry >1% and >10% of
the downstream energy flux, respectively. Our results suggest limits on the
magnetization of relativistic astrophysical flows.


title: Predictions for Nongaussianity from Nonlocal Inflation

abstract:
  In our previous work the nonlinearity parameter f_NL, which characterizes
nongaussianity in the cosmic microwave background, was estimated for a class of
inflationary models based on nonlocal field theory. These models include p-adic
inflation and generically have the remarkable property that slow roll inflation
can proceed even with an extremely steep potential. Previous calculations found
that large nongaussianity is possible; however, the technical complications
associated with studying perturbations in theories with infinitely many
derivatives forced us to provide only an order of magnitude estimate for f_NL.
We reconsider the problem of computing f_NL in nonlocal inflation models,
showing that a particular choice of field basis and recent progress in
cosmological perturbation theory makes an exact computation possible. We
provide the first quantitatively accurate computation of the bispectrum in
nonlocal inflation, confirming our previous claim that it can be observably
large. We show that the shape of the bispectrum in this class of models makes
it observationally distinguishable from Dirac-Born-Infeld inflation models.


title:
A New Estimate of the Hubble Time with Improved Modeling of
  Gravitational Lenses

abstract:
  This paper examines free-form modeling of gravitational lenses using Bayesian
ensembles of pixelated mass maps. The priors and algorithms from previous work
are clarified and significant technical improvements are made. Lens
reconstruction and Hubble Time recovery are tested using mock data from simple
analytic models and recent galaxy-formation simulations. Finally, using
published data, the Hubble Time is inferred through the simultaneous
reconstruction of eleven time-delay lenses. The result is
H_0^{-1}=13.7^{+1.8}_{-1.0} Gyr.


title: First-Year Spectroscopy for the SDSS-II Supernova Survey

abstract:
  This paper presents spectroscopy of supernovae discovered in the first season
of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for
and measures multi-band light curves of supernovae in the redshift range z =
0.05 - 0.4, complementing existing surveys at lower and higher redshifts. Our
goal is to better characterize the supernova population, with a particular
focus on SNe Ia, improving their utility as cosmological distance indicators
and as probes of dark energy. Our supernova spectroscopy program features
rapid-response observations using telescopes of a range of apertures, and
provides confirmation of the supernova and host-galaxy types as well as precise
redshifts. We describe here the target identification and prioritization, data
reduction, redshift measurement, and classification of 129 SNe Ia, 16
spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first
season. We also describe our efforts to measure and remove the substantial host
galaxy contamination existing in the majority of our SN spectra.


title: Entanglement and Density Matrix of a Block of Spins in AKLT Model

abstract:
  We study a 1-dimensional AKLT spin chain, consisting of spins $S$ in the bulk
and $S/2$ at both ends. The unique ground state of this AKLT model is described
by the Valence-Bond-Solid (VBS) state. We investigate the density matrix of a
contiguous block of bulk spins in this ground state. It is shown that the
density matrix is a projector onto a subspace of dimension $(S+1)^{2}$. This
subspace is described by non-zero eigenvalues and corresponding eigenvectors of
the density matrix. We prove that for large block the von Neumann entropy
coincides with Renyi entropy and is equal to $\ln(S+1)^{2}$.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title: Continuous-time auxiliary field Monte Carlo for quantum impurity models

abstract:
  We present a continuous-time Monte Carlo method for quantum impurity models,
which combines a weak-coupling expansion with an auxiliary-field decomposition.
The method is considerably more efficient than Hirsch-Fye and free of time
discretization errors, and is particularly useful as impurity solver in large
cluster dynamical mean field theory (DMFT) calculations.


title: Pumping angular momentum by driven chaotic scattering

abstract:
  Chaotic scattering with an internal degree of freedom and the possibility to
generate directed transport of angular momentum is studied in a specific model,
a magnetic dipole moving in a periodically modulated magnetic field confined to
a compact region in space. We show that this system is an irregular scatterer
in large parts of its parameter space. If in addition all spatio-temporal
symmetries are broken, directed transport of mass as well as angular momentum
occurs. The sensitive parameter dependence of the corresponding currents
includes frequent sign reversals. Zeros of either quantity entail the exclusive
occurrence of the other and thus give rise in particular to angular-momentum
separation without mass transport as a classical analogue of spin-polarized
currents.


title: Black Hole Dynamics From Atmospheric Science

abstract:
  In this note, we derive (to third order in derivatives of the fluid velocity)
a 2+1 dimensional theory of fluid dynamics that governs the evolution of
generic long-wavelength perturbations of a black brane or large black hole in
four-dimensional gravity with negative cosmological constant, applying a
systematic procedure developed recently by Bhattacharyya, Hubeny, Minwalla, and
Rangamani. In the regime of validity of the fluid-dynamical description, the
black-brane evolution will generically correspond to a turbulent flow.
Turbulence in 2+1 dimensions has been well studied analytically, numerically,
experimentally, and observationally as it provides a first approximation to the
large scale dynamics of planetary atmospheres. These studies reveal dramatic
differences between fluid flows in 2+1 and 3+1 dimensions, suggesting that the
dynamics of perturbed four and five dimensional large AdS black holes may be
qualitatively different. However, further investigation is required to
understand whether these qualitative differences exist in the regime of fluid
dynamics relevant to black hole dynamics.


title:
Effects of boundaries and density inhomogeneity on states of vortex
  matter in Bose--Einstein condensates at finite temperature

abstract:
  Most of the literature on quantum vortices predicting various states of
vortex matter in three dimensions at finite temperatures in quantum fluids is
based on an assumption of an extended and homogeneous system. It is well known
not to be the case in actual Bose--Einstein condensates in traps which are
finite systems with nonuniform density. This raises the question to what extent
one can speak of different aggregate states of vortex matter (vortex lattices,
liquids and tensionless vortex tangle) in these system. To address this point,
in the present work we focus on the finite-size, boundaries and density
inhomogeneity effects on thermal vortex matter in a Bose--Einstein condensate.
To this end we perform Monte Carlo simulations on a model system describing
trapped Bose--Einstein condensates. Throughout the paper, we draw on analogies
with results for vortex matter obtained for extended systems. This work
suggests that finiteness and intrinsic inhomogeneity of the system not
withstanding, one nonetheless can approximately invoke the notion of distinct
aggregate states of vortex matter realized at certain length scales. This might
be helpful, in particular in search of possible new states of vortex matter in
Bose--Einstein condensates with multiple components and different symmetries.


title:
Assembling the Ingredients for a Jet: How Do Large-Scale Magnetic Fields
  Get There and What Happens When They Do?

abstract:
  Jets and outflows are observed around a wide variety of accreting objects and
seem to be a near-ubiquitous feature of accretion disks. Large-scale magnetic
fields are thought to be necessary for jet formation in many systems, but a
longstanding puzzle is that the turbulence which is responsible for inward disk
accretion should be even more efficient at causing a large-scale magnetic field
to diffuse outward; it just doesn't seem possible to build up a strong field in
the inner disk through advection of a weak one from outside. Here, we report
theoretical work which challenges this conventional wisdom and shows that the
surface layer of the disk (which is nonturbulent) can easily advect magnetic
fields inward. This opens up the possibility for more diverse and robust jet
formation than is seen in numerical simulations which assume that the
large-scale field must be generated entirely via a dynamo within the inner
disk. In addition, strong disk turbulence (as inferred from observations) can
naturally be explained by the magnetorotational instability feeding off a
large-scale magnetic field anchored in the surface layer.


title: Reading the Electron Clock

abstract:
  If electron zitterbewegung is a real effect, it should generate an electric
dipole field oscillating with the zitterbewegung frequency 2mc^2/hbar. The
possibility of detecting it as a resonance in electron channeling is analyzed.


title: Rayleigh scattering in the transit spectrum of HD 189733b

abstract:
  The transit spectrum of the exoplanet HD 189733b has recently been obtained
between 0.55 and 1.05 microns. Here we present an analysis of this spectrum. We
develop first-order equations to interpret absorption spectra. In the case of
HD 189733b, we show that the observed slope of the absorption as a function of
wavelength is characteristic of extinction proportional to the inverse of the
fourth power of the wavelength (lambda^-4). Assuming an extinction dominated by
Rayleigh scattering, we derive an atmospheric temperature of 1340+/-150 K. If
molecular hydrogen is responsible for the Rayleigh scattering, the atmospheric
pressure at the planetary characteristic radius of 0.1564 stellar radius must
be 410+/-30 mbar. However the preferred scenario is scattering by condensate
particles. Using the Mie approximation, we find that the particles must have a
low value for the imaginary part of the refraction index. We identify MgSiO3 as
a possible abundant condensate whose particle size must be between 0.01 and 0.1
microns. For this condensate, assuming solar abundance, the pressure at 0.1564
stellar radius is found to be between a few microbars and few millibars, and
the temperature is found to be in the range 1340-1540 K, and both depend on the
particle size.


title: Goodness in the Axis of Evil

abstract:
  An unexpected alignment of 2-4-8-16 cosmic microwave background spherical
harmonic directions with the direction of a surprisingly large WMAP temperature
minimum, a large radio galaxy void, and an unexpected alignment and handedness
of galaxy spins have been observed. The alignments point to RA=202 degrees,
delta = 25 degrees and are termed the ``Axis of Evil''. Already many authors
have commented about how the AE impacts our understanding of how structure
emerged in the Universe within the framework of Lamda-CDM, warm dark matter,
string theory, and hydro-gravitational dynamics (HGD). The latter uniquely
predicts the size scales of the voids and matter condensations, based upon
estimates of fluid forces in the early phases of structure formation. Reported
departures from simple Gaussian properties of the WMAP data favor two regimes
of turbulent structure formation, and from these we make predictions of the
nature of finer structure expected to be measured with the PLANCK spacecraft.
  From HGD, friction has limited the expansion of superclusters to 30 Mpc but
supervoids have expanded with the universe to 300 Mpc.


title: Toy Models for Retrocausality

abstract:
  A number of writers have been attracted to the idea that some of the
peculiarities of quantum theory might be manifestations of 'backward' or
'retro' causality, underlying the quantum description. This idea has been
explored in the literature in two main ways: firstly in a variety of explicit
models of quantum systems, and secondly at a conceptual level. This note
introduces a third approach, intended to complement the other two. It describes
a simple toy model, which, under a natural interpretation, shows how
retrocausality can emerge from simple global constraints. The model is also
useful in permitting a clear distinction between the kind of retrocausality
likely to be of interest in QM, and a different kind of reverse causality, with
which it is liable to be confused. The model is proposed in the hope that
future elaborations might throw light on the potential of retrocausality to
account for quantum phenomena.


title:
Topological Entanglement Entropy in Chern-Simons Theories and Quantum
  Hall Fluids

abstract:
  We compute directly the entanglement entropy of spatial regions in
Chern-Simons gauge theories in 2+1 dimensions using surgery. We use these
results to determine the universal topological piece of the entanglement
entropy for Abelian and non-Abelian quantum Hall fluids.


title: Coherent method for detection of gravitational wave bursts

abstract:
  We describe a coherent network algorithm for detection and reconstruction of
gravitational wave bursts. The algorithm works for two and more arbitrarily
aligned detectors and can be used for both all-sky and triggered burst
searches. We describe the main components of the algorithm, including the
time-frequency analysis in wavelet domain, construction of the likelihood
time-frequency maps, the identification and selection of burst events.


title:
A new approach for efficient simulation of Coulomb interactions in ionic
  fluids

abstract:
  We propose a simplified version of local molecular field (LMF) theory to
treat Coulomb interactions in simulations of ionic fluids. LMF theory relies on
splitting the Coulomb potential into a short-ranged part that combines with
other short-ranged core interactions and is simulated explicitly. The averaged
effects of the remaining long-ranged part are taken into account through a
self-consistently determined effective external field. The theory contains an
adjustable length parameter sigma that specifies the cut-off distance for the
short-ranged interaction. This can be chosen to minimize the errors resulting
from the mean-field treatment of the complementary long-ranged part. Here we
suggest that in many cases an accurate approximation to the effective field can
be obtained directly from the equilibrium charge density given by the Debye
theory of screening, thus eliminating the need for a self-consistent treatment.
In the limit sigma -> 0, this assumption reduces to the classical Debye
approximation. We examine the numerical performance of this approximation for a
simple model of a symmetric ionic mixture. Our results for thermodynamic and
structural properties of uniform ionic mixtures agree well with similar results
of Ewald simulations of the full ionic system. In addition we have used the
simplified theory in a grand-canonical simulation of a nonuniform ionic mixture
where an ion has been fixed at the origin. Simulations using short-ranged
truncations of the Coulomb interactions alone do not satisfy the exact
condition of complete screening of the fixed ion, but this condition is
recovered when the effective field is taken into account. We argue that this
simplified approach can also be used in the simulations of more complex
nonuniform systems.


title: The dynamics of human body weight change

abstract:
  An imbalance between energy intake and energy expenditure will lead to a
change in body weight (mass) and body composition (fat and lean masses). A
quantitative understanding of the processes involved, which currently remains
lacking, will be useful in determining the etiology and treatment of obesity
and other conditions resulting from prolonged energy imbalance. Here, we show
that the long-term dynamics of human weight change can be captured by a
mathematical model of the macronutrient flux balances and all previous models
are special cases of this model. We show that the generic dynamical behavior of
body composition for a clamped diet can be divided into two classes. In the
first class, the body composition and mass are determined uniquely. In the
second class, the body composition can exist at an infinite number of possible
states. Surprisingly, perturbations of dietary energy intake or energy
expenditure can give identical responses in both model classes and existing
data are insufficient to distinguish between these two possibilities. However,
this distinction is important for the efficacy of clinical interventions that
alter body composition and mass.


title: Characterization of the convergence of stationary Fokker-Planck learning

abstract:
  The convergence properties of the stationary Fokker-Planck algorithm for the
estimation of the asymptotic density of stochastic search processes is studied.
Theoretical and empirical arguments for the characterization of convergence of
the estimation in the case of separable and nonseparable nonlinear optimization
problems are given. Some implications of the convergence of stationary
Fokker-Planck learning for the inference of parameters in artificial neural
network models are outlined.


title: Imaging a 1-electron InAs quantum dot in an InAs/InP nanowire

abstract:
  Nanowire heterostructures define high-quality few-electron quantum dots for
nanoelectronics, spintronics and quantum information processing. We use a
cooled scanning probe microscope (SPM) to image and control an InAs quantum dot
in an InAs/InP nanowire, using the tip as a movable gate. Images of dot
conductance vs. tip position at T = 4.2 K show concentric rings as electrons
are added, starting with the first electron. The SPM can locate a dot along a
nanowire and individually tune its charge, abilities that will be very useful
for the control of coupled nanowire dots.


title: On matrix elements for the quantized cat map modulo prime powers

abstract:
  The quantum cat map is a model for a quantum system with underlying chaotic
dynamics. In this paper we study the matrix elements of smooth observables in
this model, when taking arithmetic symmetries into account. We give explicit
formulas for the matrix elements as certain exponential sums. With these
formulas we can show that there are sequences of eigenfunctions for which the
matrix elements decay significantly slower then was previously conjectured. We
also prove a limiting distribution for the fluctuation of the normalized matrix
elements around their average.


title:
Three-dimensional stability of magnetically confined mountains on
  accreting neutron stars

abstract:
  We examine the hydromagnetic stability of magnetically confined mountains,
which arise when material accumulates at the magnetic poles of an accreting
neutron star. We extend a previous axisymmetric stability analysis by
performing three-dimensional simulations using the ideal-magnetohydrodynamic
(ideal-MHD) code \textsc{zeus-mp}, investigating the role played by boundary
conditions, accreted mass, stellar curvature, and (briefly) toroidal magnetic
field strength. We find that axisymmetric equilibria are susceptible to the
undular sub-mode of the Parker instability but are not disrupted. The
line-tying boundary condition at the stellar surface is crucial in stabilizing
the mountain. The nonlinear three-dimensional saturation state of the
instability is characterized by a small degree of nonaxisymmetry ($\la 0.1$ per
cent) and a mass ellipticity of $\epsilon \sim 10^{-5}$ for an accreted mass of
$M_a = 10^{-5} M_\odot$. Hence there is a good prospect of detecting
gravitational waves from accreting millisecond pulsars with long-baseline
interferometers such as Advanced LIGO. We also investigate the ideal-MHD
spectrum of the system, finding that long-wavelength poloidal modes are
suppressed in favour of toroidal modes in the nonaxisymmetric saturation state.


title: First Detection of Cosmic Structure in the 21-cm Intensity Field

abstract:
  We present the first statistically significant detection of cosmic structure
using broadly distributed hydrogen radio emission. This is accomplished using a
cross correlation with optical galaxies. Statistical noise levels of $20 \mu $K
are achieved, unprecedented in this frequency band. This lends support to the
idea that large volumes of the universe can be rapidly mapped without the need
to resolve individual faint galaxies, enabling precise constraints to dark
energy models. We discuss strategies for improved intensity mapping.


title: NMR study on the local structure in La-based high-Tc cuprates

abstract:
  To date, there has been no evidence for the macroscopic structural phase
transition to the low temperature tetragonal structure (LTT) with a space group
P42/ncm in high-TC cuprate of rare earth-free La2-xSrxCuO4 (LSCO). By
investigating Cu-NMR on single crystals, we have found that spatially
incoherent LTT structure emerges below 50 K in the sample with x=0.12. This
incoherent structure is considered to play a key role for the slight depression
of the superconductivity around x=1/8.


title:
Lepton Flavor Violating Muon Decays in a Model of Electroweak-Scale
  Right-Handed Neutrinos

abstract:
  The small neutrino mass observed in neutrino oscillations is nicely explained
by the seesaw mechanism. Rich phenomenology is generally expected if the heavy
neutrinos are not much heavier than the electroweak scale. A model with this
feature built in has been suggested recently by Hung. The model keeps the
standard gauge group but introduces chirality-flipped partners for the
fermions. In particular, a right-handed neutrino forms a weak doublet with a
charged heavy lepton, and is thus active. We analyze the lepton flavor
structure in gauge interactions. The mixing matrices in charged currents (CC)
are generally non-unitary, and their deviation from unitarity induces flavor
changing neutral currents (FCNC). We calculate the branching ratios for the
rare decays \mu\to e\gamma and \mu\to ee\bar e due to the gauge interactions.
Although the former is generally smaller than the latter by three orders of
magnitude, parameter regions exist in which \mu\to e\gamma is reachable in the
next generation of experiments even if the current stringent bound on \mu\to
ee\bar e is taken into account. If light neutrinos dominate for \mu\to e\gamma,
the latter cannot set a meaningful bound on unitarity violation in the mixing
matrix of light leptons due to significant cancelation between CC and FCNC
contributions. Instead, the role is taken over by the decay \mu\to ee\bar e.


title: Aperiodic order and pure point diffraction

abstract:
  We give a leisurely introduction into mathematical diffraction theory with a
focus on pure point diffraction. In particular, we discuss various
characterisations of pure point diffraction and common models arising from cut
and project schemes. We finish with a list of open problems.


title:
The old open cluster NGC 2112: updated estimates of fundamental
  parameters based on a membership analysis

abstract:
  We report on a new, wide field ($20^{\prime} \times 20^{\prime}$), multicolor
($UBVI$), photometric campaign in the area of the nearby old open cluster NGC
2112. At the same time, we provide medium-resolution spectroscopy of 35 (and
high-resolution of additional 5) Red Giant and Turn Off stars. This material is
analyzed with the aim to update the fundamental parameters of this
traditionally difficult cluster, which is very sparse and suffers from heavy
field star contamination. Among the 40 stars with spectra, we identified 21
{\it bona fide} radial velocity members which allow us to put more solid
constraints on the cluster's metal abundance, long suggested to be as low as
the metallicity of globulars. As indicated earlier by us on a purely
photometric basis (Carraro et al. 2002), the cluster [Fe/H] abundance is
slightly super-solar ([Fe/H] =0.16$\pm$0.03) and close to the Hyades value, as
inferred from a detailed abundance analysis of 3 of the 5 stars with higher
resolution spectra. Abundance ratios are also marginally super solar. Based on
this result, we revise the properties of NGC 2112 using stellar models from the
Padova and Yale-Yonsei groups. For this metal abundance, we find the cluster's
age, reddening, and distance values are 1.8 Gyr, 0.60 mag, and 940 pc,
respectively. Both the Yale-Yonsei and Padova models predict the same values
for the fundamental parameters within the errors. Overall, NGC 2112 is a
typical solar neighborhood, thin disk star cluster, sharing the same chemical
properties of F-G stars and open clusters close to the Sun. This investigation
outlines the importance of a detailed membership analysis in the study of disk
star clusters.


title:
Five-dimensional Monopole Equation with Hedge-Hog Ansatz and Abel's
  Differential Equation

abstract:
  We review the generalized monopole in the five-dimensional Euclidean space. A
numerical solution with the Hedge-Hog ansatz is studied. The Bogomol'nyi
equation becomes a second order autonomous non-linear differential equation.
The equation can be translated into the Abel's differential equation of the
second kind and is an algebraic differential equation.


title:
Optimal angular window for observing Dark Matter annihilation from the
  Galactic Center region: the case of gamma-ray lines

abstract:
  Although the emission of radiation from dark matter annihilation is expected
to be maximized at the Galactic Center, geometric factors and the presence of
point-like and diffuse backgrounds make the choice of the angular window size
to optimize the chance of a signal detection a non-trivial problem. Contrarily
to what is often assumed, we find that the best strategy is to focus on a
window size around the Galactic Center of ~ 1 deg to >~ 30 deg, where the
optimal size depends on the angular distribution of the signal and the
backgrounds. Although our conclusions are general, we illustrate this point in
the particular case of annihilation into two monochromatic photons in the
phenomenologically most interesting range of energy 45 GeV < E < 80 GeV, which
is of great interest for the GLAST satellite. We find for example that Dark
Matter models with sufficiently strong line annihilation signals, like the
Inert Doublet Model, may be detectable without or with very moderate boost
factors.


title: Alpha-particle condensation in 16O via a full four-body OCM calculation

abstract:
  In order to explore the 4 \alpha-particle condensate state in 16O, we solve a
full four-body equation of motion based on the 4 \alpha OCM (Orthogonality
Condition Model) in a large 4 \alpha model space spanned by Gaussian basis
functions. A full spectrum up to the 0_6^+ state is reproduced consistently
with the lowest six 0^+ states of the experimental spectrum. The 0^+_6 state is
obtained at about 2 MeV above the 4 \alpha breakup threshold and has a dilute
density structure, with a radius of about 5 fm. The state has an appreciably
large \alpha condensate fraction of 61 %, and a large component of
\alpha+12C(0_2^+) configuration, both features being reliable evidence for this
state to be of 4 \alpha condensate nature.


title: Some remarks on the size of bodies and black holes

abstract:
  We consider the application of stable marginally outer trapped surfaces to
problems concerning the size of material bodies and the area of black holes.
The results presented extend to general initial data sets (V,g,K) previous
results assuming either maximal (tr K = 0) or time-symmetric (K = 0) initial
data.


title: Laplacians on the basilica Julia set

abstract:
  We consider the basilica Julia set of the polynomial $P(z)=z^{2}-1$ and
construct all possible resistance (Dirichlet) forms, and the corresponding
Laplacians, for which the topology in the effective resistance metric coincides
with the usual topology. Then we concentrate on two particular cases. One is a
self-similar harmonic structure, for which the energy renormalization factor is
2, the spectral dimension is $\log9/\log6$, and we can compute all the
eigenvalues and eigenfunctions by a spectral decimation method. The other is
graph-directed self-similar under the map $z\mapsto P(z)$; it has energy
renormalization factor $\sqrt2$ and spectral dimension 4/3, but the exact
computation of the spectrum is difficult. The latter Dirichlet form and
Laplacian are in a sense conformally invariant on the basilica Julia set.


title: From Dual Models to String Theory

abstract:
  A personal view is given of the development of string theory out of dual
models, including the analysis of the structure of the physical states and the
proof of the No-Ghost Theorem, the quantization of the relativistic string, and
the calculation of fermion-fermion scattering.


title:
Valuation of Mortality Risk via the Instantaneous Sharpe Ratio:
  Applications to Life Annuities

abstract:
  We develop a theory for valuing non-diversifiable mortality risk in an
incomplete market. We do this by assuming that the company issuing a
mortality-contingent claim requires compensation for this risk in the form of a
pre-specified instantaneous Sharpe ratio. We apply our method to value life
annuities. One result of our paper is that the value of the life annuity is
{\it identical} to the upper good deal bound of Cochrane and Sa\'{a}-Requejo
(2000) and of Bj\"{o}rk and Slinko (2006) applied to our setting. A second
result of our paper is that the value per contract solves a {\it linear}
partial differential equation as the number of contracts approaches infinity.
One can represent the limiting value as an expectation with respect to an
equivalent martingale measure (as in Blanchet-Scalliet, El Karoui, and
Martellini (2005)), and from this representation, one can interpret the
instantaneous Sharpe ratio as an annuity market's price of mortality risk.


title:
Evaluation of the Theoretical Uncertainties in the Z to ll Cross
  Sections at the LHC

abstract:
  We study the sources of systematic errors in the measurement of the Z to ll
cross-sections at the LHC. We consider the systematic errors in both the total
cross-section and acceptance for anticipated experimental cuts. We include the
best available analysis of QCD effects at NNLO in assessing the effect of
higher order corrections and PDF and scale uncertainties on the theoretical
acceptance. In addition, we evaluate the error due to missing NLO electroweak
corrections and propose which MC generators and computational schemes should be
implemented to best simulate the events.


title: Algebraic Structure of a Master Equation with Generalized Lindblad Form

abstract:
  The quantum damped harmonic oscillator is described by the master equation
with usual Lindblad form. The equation has been solved completely by us in
arXiv : 0710.2724 [quant-ph]. To construct the general solution a few facts of
representation theory based on the Lie algebra $su(1,1)$ were used.
  In this paper we treat a general model described by a master equation with
generalized Lindblad form. Then we examine the algebraic structure related to
some Lie algebras and construct the interesting approximate solution.


title: On the Capacity and Design of Limited Feedback Multiuser MIMO Uplinks

abstract:
  The theory of multiple-input multiple-output (MIMO) technology has been
well-developed to increase fading channel capacity over single-input
single-output (SISO) systems. This capacity gain can often be leveraged by
utilizing channel state information at the transmitter and the receiver. Users
make use of this channel state information for transmit signal adaptation. In
this correspondence, we derive the capacity region for the MIMO multiple access
channel (MIMO MAC) when partial channel state information is available at the
transmitters, where we assume a synchronous MIMO multiuser uplink. The partial
channel state information feedback has a cardinality constraint and is fed back
from the basestation to the users using a limited rate feedback channel. Using
this feedback information, we propose a finite codebook design method to
maximize sum-rate. In this correspondence, the codebook is a set of transmit
signal covariance matrices. We also derive the capacity region and codebook
design methods in the case that the covariance matrix is rank-one (i.e.,
beamforming). This is motivated by the fact that beamforming is optimal in
certain conditions. The simulation results show that when the number of
feedback bits increases, the capacity also increases. Even with a small number
of feedback bits, the performance of the proposed system is close to an optimal
solution with the full feedback.


title: General Algorithms for Testing the Ambiguity of Finite Automata

abstract:
  This paper presents efficient algorithms for testing the finite, polynomial,
and exponential ambiguity of finite automata with $\epsilon$-transitions. It
gives an algorithm for testing the exponential ambiguity of an automaton $A$ in
time $O(|A|_E^2)$, and finite or polynomial ambiguity in time $O(|A|_E^3)$.
These complexities significantly improve over the previous best complexities
given for the same problem. Furthermore, the algorithms presented are simple
and are based on a general algorithm for the composition or intersection of
automata. We also give an algorithm to determine the degree of polynomial
ambiguity of a finite automaton $A$ that is polynomially ambiguous in time
$O(|A|_E^3)$. Finally, we present an application of our algorithms to an
approximate computation of the entropy of a probabilistic automaton.


title: Relationship between stochastic flows and connection forms

abstract:
  In this article I will prove new representation for the Levi-Civita
connection in terms of the stochastic flow corresponding to Brownian motion on
manifold.


title:
Quantum Fluctuations of Chirality in One-Dimensional Spin-1/2
  Multiferroics: Gapless Dielectric Response from Phasons and Chiral Solitons

abstract:
  We present a quantum theory for one-dimensional spin-1/2 multiferroics, where
the vector spin chirality couples with the electric polarization. Based on
exact diagonalization and bosonization, it is shown that quantum fluctuations
appreciably reduce the chiral ordering amplitude and the associated
ferroelectric polarization. This yields nearly collinear spin correlations in
short-range scales, in qualitative agreement with recent neutron scattering
experiments. There appear gapless chirality excitations described by phasons
and new solitons, which can be experimentally verified from the low-energy
dielectric response.


title: Higgs Mass Bounds, Type II SeeSaw and LHC

abstract:
  In type II seesaw utilized to explain the observed neutrino masses and
mixings, one extends the Standard Model (SM) by introducing scalar fields which
transform as a triplet under the electroweak gauge symmetry. New scalar
couplings involving the Higgs doublet then appear and, as we show, these have
important implications for the Higgs boson mass bounds obtained using vacuum
stability and perturbativity arguments. We identify, in particular, regions of
the parameter space which permit the SM Higgs boson to be as light as 114.4
GeV, the LEP2 bound. The triplet scalars include doubly charged particles whose
masses could, in principle, be in the few hundred GeV range, and so they may be
accessible at the LHC.


title:
Weak Ferromagnetism Accompanying Loop current order in Underdoped
  Cuprates

abstract:
  We discuss the necessary symmetry conditions and the different ways in which
they can be physically realized for the occurrence of ferromagnetism
accompanying the loop current orbital magnetic order observed by polarized
neutron-diffraction experiments or indeed any other conceivable principal order
in the under-doped phase of cuprates. We contrast the Kerr effect experiments
in single crystals observing ferromagnetism with the direct magnetization
measurements in large powder samples, which do not observe it. We also suggest
experiments to resolve the differences among the experiments, all of which we
believe to be correct.


title: Decay of Massive Dirac Hair on a Brane-World Black Hole

abstract:
  We investigate the intermediate and late-time behaviour of the massive Dirac
spinor field in the background of static spherically symmetric brane-world
black hole solutions. The intermediate asymptotic behaviour of the massive
spinor field exhibits a dependence on the field's parameter mass as well as the
multiple number of the wave mode. On the other hand, the late-time behaviour
power law decay has a rate which is independent of those factors.


title: Supersingular Kottwitz-Rapoport strata and Deligne-Lusztig varieties

abstract:
  We investigate Siegel modular varieties in positive characteristic with
Iwahori level structure. On these spaces, we have the Newton stratification,
and the Kottwitz-Rapoport stratification; one would like to understand how
these stratifications are related to each other. We give a simple description
of all KR strata which are entirely contained in the supersingular locus as
disjoint unions of Deligne-Lusztig varieties. We also give an explicit
numerical description of the KR stratification in terms of abelian varieties.


title: Search for a Realistic Orbifold Grand Unification

abstract:
  We review the prototype model of a grand unified theory on the orbifold
$S^1/Z_2$ and discuss topics related to the choice of boundary conditions; the
dynamical rearrangement of gauge symmetry and the equivalence classes of BCs.
We explore a family unification scenario by orbifolding.


title: Binding Energies of 6Li p-wave Feshbach Molecules

abstract:
  We present measurements of the binding energies of $^6$Li p-wave Feshbach
molecules formed in combinations of the (F = 1/2, m_F = +1/2), (1), and (F =
1/2, m_F = -1/2), (2), states. The binding energies scale linearly with
magnetic field detuning for all three resonances. The relative molecular
magnetic moments are found to be $113 \pm 7 \mu$K/G, $111 \pm 6 \mu$K/G and
$118 \pm 8 \mu$K/G for the (1)-(1), (1)-(2) and (2)-(2) resonances,
respectively, in good agreement with theoretical predictions. Closed channel
amplitudes and the size of the p-wave molecules are obtained theoretically from
full closed-coupled calculations.


title: Quadratic superconducting cosmic strings revisited

abstract:
  It has been shown that 5-dimensional general relativity action extended by
appropriate quadratic terms admits a singular superconducting cosmic string
solution. We search for cosmic strings endowed with similar and extended
physical properties by directly integrating the non-linear matrix field
equations thus avoiding the perturbative approach by which we constructed the
above-mentioned \textsl{exact} solution. The most general superconducting
cosmic string, subject to some constraints, will be derived and shown to be
mathematically \textsl{unique} up to linear coordinate transformations mixing
its Killing vectors. The most general solution, however, is not globally
equivalent to the old one due to the existence of Killing vectors with closed
orbits.


title:
Energy-Dependence of the Nucleon Self-Energies in Off-Mass-Shell Energy
  Region and the Gamow-Teller Sum-Rule in the Relativistic Hartree-Fock
  Approach

abstract:
  The relativistic Hartree approximation predicts a deep attractive potential
for antinucleon, which largely reduce the threshold energies of the
nucleon-antinucleon (N-Nbar) production. This effect has played an important
role to explain the quenching of the Gamow-Teller (GT) strength because the
quenched strength in the particle-hole excitation is partially taken by the
nucleon-antinucleon production. On the other hand antiproton experiments do not
reveal deep attractive potential for antinucleon. In this paper we study
energy-dependence of the nucleon self-energies in the relativistic Hartree-Fock
(RHF) approximation in off-mass-shell states. Then we demonstrate that the
antinucleon appearing in low energy observables is in the off-mass-shell energy
region and its properties are quite different from that at the on-mass-shell
state. Furthermore we show that the quenched amount of the GT strength is not
taken only by the \NNbar production but also by the meson production through
the imaginary part of the nucleon self-energy in the RHF approximation.


title: Plurisubharmonic functions with weak singularities

abstract:
  We study the complex Monge-Amp\`ere operator in bounded hyperconvex domains
of $\C^n$. We introduce a scale of classes of weakly singular plurisubharmonic
functions : these are functions of finite weighted Monge-Amp\`ere energy. They
generalize the classes introduced by U.Cegrell, and give a stratification of
the space of (almost) all unbounded plurisubharmonic functions. We give an
interpretation of these classes in terms of the speed of decreasing of the
Monge-Amp\`ere capacity of sublevel sets and solve associated complex
Monge-Amp\`ere equations.


title:
Decay of the cosmological constant by Hawking radiation as quantum
  tunneling

abstract:
  We calculate the emission rate of Hawking radiation from the cosmological
horizon by quantum tunneling approaches. Using the Hamilton-Jacobi and the null
geodesic methods, two typical observations are obtained. First, the spectrum of
radiation is not strictly pure thermal. Second, the value of the cosmological
constant decreases. Our calculation is different from other similar works about
Hawking radiation from the cosmological horizon in that the horizon does not
shrink but expands by taking into account the back-reaction effect. We show
that when a positive frequency particle is materialized near the cosmological
horizon, the contribution of a negative frequency partner to the background
geometry lowers the value of the cosmological constant. We also touch upon
thermodynamics of de Sitter space and the quantum creation of universe.


title: The Forgiving Tree: A Self-Healing Distributed Data Structure

abstract:
  We consider the problem of self-healing in peer-to-peer networks that are
under repeated attack by an omniscient adversary. We assume that the following
process continues for up to n rounds where n is the total number of nodes
initially in the network: the adversary deletes an arbitrary node from the
network, then the network responds by quickly adding a small number of new
edges.
  We present a distributed data structure that ensures two key properties.
First, the diameter of the network is never more than $O(\log \Delta)$ times
its original diameter, where $\Delta$ is the maximum degree of the network
initially. We note that for many peer-to-peer systems, $\Delta$ is
polylogarithmic, so the diameter increase would be a O(log log n)
multiplicative factor. Second, the degree of any node never increases by more
than 3 over its original degree. Our data structure is fully distributed, has
O(1) latency per round and requires each node to send and receive O(1) messages
per round. The data structure requires an initial setup phase that has latency
equal to the diameter of the original network, and requires, with high
probability, each node v to send O(log n) messages along every edge incident to
v. Our approach is orthogonal and complementary to traditional topology-based
approaches to defending against attack.


title: Chaos in Galaxies

abstract:
  After general considerations about limits of theories and models, where small
changes may imply large effects, we discuss three cases in galactic
astrophysics illustrating how galactic dynamics models may become insufficient
when previously neglected effects are taken into account: 1) Like in 3D
hydrodynamics, the non-linearity of the Poisson-Boltzmann system may imply
dissipation through the growth of discontinuous solutions. 2) The relationship
between the microscopic exponential sensitivity of N-body systems and the
stability of mean field galaxy models. 3) The role of quantum physics in the
dynamics of structure formation, considering that cosmological neutrinos are
massive and semi-degenerate fermions.


title:
Conductance and current noise of a superconductor/ferromagnet quantum
  point contact

abstract:
  We study the conductance and current noise of a superconductor/ferromagnet
(S/F) single channel Quantum Point Contact (QPC) as a function of the QPC bias
voltage, using a scattering approach. We show that the Spin-Dependence of
Interfacial Phase Shifts (SDIPS) acquired by electrons upon scattering by the
QPC can strongly modify these signals. For a weakly transparent contact, the
SDIPS induces sub-gap resonances in the conductance and differential Fano
factor curves of the QPC. For high transparencies, these resonances are
smoothed, but the shape of the signals remain extremely sensitive to the SDIPS.
We show that noise measurements could help to gain more information on the
device, e.g. in cases where the SDIPS modifies qualitatively the differential
Fano factor of the QPC but not the conductance.


title: Relative radial mass and rigidity of some warped product manifolds

abstract:
  We give a Riccati type formula adapted for two metrics having the same
geodesics rays starting from a point or orthogonal to an hypersurface, one of
these metrics being a warped product if the dimension $n$ is greater than or
equal to 3. This formula has non-trivial geometric consequences such as a
positive mass type theorem and other rigidity results. We also apply our result
to some standard models.


title: The Supermagic Square in characteristic 3 and Jordan superalgebras

abstract:
  Recently, the classical Freudenthal Magic Square has been extended over
fields of characteristic 3 with two more rows and columns filled with (mostly
simple) Lie superalgebras specific of this characteristic. This Supermagic
Square will be reviewed and some of the simple Lie superalgebras that appear
will be shown to be isomorphic to the Tits-Kantor-Koecher Lie superalgebras of
some Jordan superalgebras.


title: Impact of loop statistics on the thermodynamics of RNA folding

abstract:
  Loops are abundant in native RNA structures and proliferate close to the
unfolding transition. By including a statistical weight ~ l^{-c} for loops of
length l in the recursion relation for the partition function, we show that the
calculated heat capacity depends sensitively on the presence and value of the
exponent c, even of short t-RNA. For homo-RNA we analytically calculate the
critical temperature and critical exponents which exhibit a non-universal
dependence on c.


title: Pressure-induced order-disorder phase transition in superconducting CaC6

abstract:
  By means of synchrotron X-ray diffraction, we studied the effect of high
pressure, P, up to 13 GPa on the room temperature crystal structure of
superconducting CaC6. In this P range, no change of the pristine space group
symmetry, \textit{R\=3m}, is found. However, at 9 GPa, i.e. close to the
critical value at which a large T_c reduction was reported recently, we
observed a compressibility jump concomitant to a large broadening of Bragg
peaks. The reversibility of both effects upon depressurization and symmetry
arguments give evidence of an order-disorder phase transition of second order,
presumably associated with the Ca sublattice, which provides a full account for
the above Tc reduction.


title: How Gaussian competition leads to lumpy or uniform species distributions

abstract:
  A central model in theoretical ecology considers the competition of a range
of species for a broad spectrum of resources. Recent studies have shown that
essentially two different outcomes are possible. Either the species surviving
competition are more or less uniformly distributed over the resource spectrum,
or their distribution is 'lumped' (or 'clumped'), consisting of clusters of
species with similar resource use that are separated by gaps in resource space.
Which of these outcomes will occur crucially depends on the competition kernel,
which reflects the shape of the resource utilization pattern of the competing
species. Most models considered in the literature assume a Gaussian competition
kernel. This is unfortunate, since predictions based on such a Gaussian
assumption are not robust. In fact, Gaussian kernels are a border case
scenario, and slight deviations from this function can lead to either uniform
or lumped species distributions. Here we illustrate the non-robustness of the
Gaussian assumption by simulating different implementations of the standard
competition model with constant carrying capacity. In this scenario, lumped
species distributions can come about by secondary ecological or evolutionary
mechanisms or by details of the numerical implementation of the model. We
analyze the origin of this sensitivity and discuss it in the context of recent
applications of the model.


title: Sphalerons, Antisphalerons and Vortex Rings

abstract:
  We present new classical solutions of Weinberg-Salam theory in the limit of
vanishing Weinberg angle. In these static axially symmetric solutions, the
Higgs field vanishes either on isolated points on the symmetry axis, or on
rings centered around the symmetry axis. The solutions represent systems of
sphalerons, antisphalerons, and vortex rings.


title: Adaptive Confidence Sets for the Optimal Approximating Model

abstract:
  In the setting of high-dimensional linear models with Gaussian noise, we
investigate the possibility of confidence statements connected to model
selection. Although there exist numerous procedures for adaptive point
estimation, the construction of adaptive confidence regions is severely limited
(cf. Li, 1989). The present paper sheds new light on this gap. We develop exact
and adaptive confidence sets for the best approximating model in terms of risk.
One of our constructions is based on a multiscale procedure and a particular
coupling argument. Utilizing exponential inequalities for noncentral
chi-squared distributions, we show that the risk and quadratic loss of all
models within our confidence region are uniformly bounded by the minimal risk
times a factor close to one.


title:
Automorphic properties of generating functions for generalized rank
  moments and Durfee symbols

abstract:
  We define two-parameter generalizations of two combinatorial constructions of
Andrews: the kth symmetrized rank moment and the k-marked Durfee symbol. We
prove that three specializations of the associated generating functions are
so-called quasimock theta functions, while a fourth specialization gives
quasimodular forms. We then define a two-parameter generalization of Andrews'
smallest parts function and note that this leads to quasimock theta functions
as well. The automorphic properties are deduced using q-series identities
relating the relevant generating functions to known mock theta functions.


title:
Equidistribution of expanding translates of curves and Dirichlet's
  theorem on Diophantine approximation

abstract:
  We show that for almost all points on any analytic curve on R^{k} which is
not contained in a proper affine subspace, the Dirichlet's theorem on
simultaneous approximation, as well as its dual result for simultaneous
approximation of linear forms, cannot be improved. The result is obtained by
proving asymptotic equidistribution of evolution of a curve on a strongly
unstable leaf under certain partially hyperbolic flow on the space of
unimodular lattices in R^{k+1}. The proof involves ergodic properties of
unipotent flows on homogeneous spaces.


title:
De l'\'equation de prescription de courbure scalaire aux \'equations de
  contrainte en relativit\'e g\'en\'erale sur une vari\'et\'e asymptotiquement
  hyperbolique

abstract:
  Two problems concerning asymptotically hyperbolic manifolds with an inner
boundary are studied. First, we study scalar curvature presciption with either
Dirichlet or mean curvature prescription interior boundary condition. Then we
apply those results to the Lichnerowicz equation with (future or past) apparent
horizon interior boundary condition. In the last part we show how to construct
TT-tensors. Thus we obtain Cauchy data with constant mean curvature for
Einstein vacuum equations.


title:
Quantization of affine bodies. Theory and applications in mechanics of
  structured media

abstract:
  Discussed is kinematics and dynamics of bodies with affine degrees of
freedom, i.e., homogeneously deformable "gyroscopes". The special stress is
laid on the status and physical justification of affine dynamical invariance.
On the basis of classical Hamiltonian formalism the Schroedinger quantization
procedure is performed. Some methods of the partial separation of variables,
analytical treatment and search of rigorous solutions are developed. The
possiblity of applications in theory of structured media, nanophysics, and
molecular physics is discussed.


title:
Teleparallelism, modified Born-Infeld nonlinearity and space-time as a
  micromorphic ether

abstract:
  Discussed are field-theoretic models with degrees of freedom described by the
$n$-leg field in an $n$-dimensional "space-time" manifold. Lagrangians are
generally-covariant and invariant under the internal group GL$(n,{\bf R})$. It
is shown that the resulting field equations have some correspondence with
Einstein theory and possess homogeneous vacuum solutions given by semisimple
Lie group spaces or their appropriate deformations. There exists a
characteristic link with the generalized Born-Infeld type nonlinearity and
relativistic mechanics of structured continua. In our model signature is not
introduced by hands, but is given by integration constants for certain
differential equations.


title: QCD Evolution of Jets in the Quark-Gluon Plasma

abstract:
  The quark-gluon plasma (QGP) can be explored in relativistic heavy ion
collisions by the jet quenching signature, i.e. by the energy loss of a high
energy quark or gluon traversing the plasma. We introduce a novel QCD evolution
formalism in the leading logarithm approximation, where normal parton radiation
is interleaved with scattering on the plasma gluons occuring at a similar time
scale. The idea is elaborated in two approaches. One extends the DGLAP
evolution equations for fragmentation functions to include scatterings in the
medium, which facilitates numerical solutions for comparison with data and
provides a basis for a Monte Carlo implementation. The other approach is more
general by including also the transverse momentum dependence of the jet
evolution, which allows a separation of the scales also for the scattering term
and provides a basis for analytical investigations. The two approaches are
shown to be related and give the same characteristic softening of the jet
depending on the temperature of the plasma. A substantial effect is found at
the RHIC energy and is further enhanced at LHC. Systematic studies of data on
the energy loss could, therefore, demonstrate the existence of the QGP and
probe its properties.


title: An integrated model of traffic, geography and economy in the Internet

abstract:
  Modeling Internet growth is important both for understanding the current
network and to predict and improve its future. To date, Internet models have
typically attempted to explain a subset of the following characteristics:
network structure, traffic flow, geography, and economy. In this paper we
present a discrete, agent-based model, that integrates all of them. We show
that the model generates networks with topologies, dynamics, and (more
speculatively) spatial distributions that are similar to the Internet.


title: Tur\'an Graphs, Stability Number, and Fibonacci Index

abstract:
  The Fibonacci index of a graph is the number of its stable sets. This
parameter is widely studied and has applications in chemical graph theory. In
this paper, we establish tight upper bounds for the Fibonacci index in terms of
the stability number and the order of general graphs and connected graphs.
Tur\'an graphs frequently appear in extremal graph theory. We show that Tur\'an
graphs and a connected variant of them are also extremal for these particular
problems.


title:
Some Aspects of Testing Process for Transport Streams in Digital Video
  Broadcasting

abstract:
  This paper presents some aspects related to the DVB (Digital Video
Broadcasting) investigation. The basic aspects of DVB are presented, with an
emphasis on DVB-T version of standard. The main purpose of this research is to
analyze the way that the transmission of the transport streams is realized in
case of the Terrestrial Digital Video Broadcasting (DVB-T). To accomplish this,
first, Digital Video Broadcasting standard is presented, and then the main
aspects of DVB testing and analysis of the transport streams are investigated.
The paper presents also the results obtained using two programs designed for
DVB analysis: Mosalina and TSA.


title: White dwarf spins from low mass stellar evolution models

abstract:
  The prediction of the spins of the compact remnants is a fundamental goal of
the theory of stellar evolution. Here, we confront the predictions for white
dwarf spins from evolutionary models including rotation with observational
constraints. We perform stellar evolution calculations for stars in the mass
range 1... 3$\mso$, including the physics of rotation, from the zero age main
sequence into the TP-AGB stage. We calculate two sets of model sequences, with
and without inclusion of magnetic fields. From the final computed models of
each sequence, we deduce the angular momenta and rotational velocities of the
emerging white dwarfs. While models including magnetic torques predict white
dwarf rotational velocities between 2 and 10 km s$^{-1}$, those from the
non-magnetic sequences are found to be one to two orders of magnitude larger,
well above empirical upper limits. We find the situation analogous to that in
the neutron star progenitor mass range, and conclude that magnetic torques may
be required in order to understand the slow rotation of compact stellar
remnants in general.


title:
A Kapitza-Dirac-Talbot-Lau interferometer for highly polarizable
  molecules

abstract:
  Research on matter waves is a thriving field of quantum physics and has
recently stimulated many investigations with electrons, neutrons, atoms,
Bose-condensed ensembles, cold clusters and hot molecules. Coherence
experiments with complex objects are of interest for exploring the transition
to classical physics, for measuring molecular properties and they have even
been proposed for testing new models of space-time. For matter-wave experiments
with complex molecules, the strongly dispersive effect of the interaction
between the diffracted molecule and the grating wall is a major challenge
because it imposes enormous constraints on the velocity selection of the
molecular beam. We here describe the first experimental realization of a new
interferometer that solves this problem by combining the advantages of a
Talbot-Lau setup with the benefits of an optical phase grating and we show
quantum interference with new large molecules.


title:
Implementing a Test Strategy for an Advanced Video Acquisition and
  Processing Architecture

abstract:
  This paper presents some aspects related to test process of an advanced video
system used in remote IP surveillance. The system is based on a Pentium
compatible architecture using the industrial standard PC104+. First the overall
architecture of the system is presented, involving both hardware or software
aspects. The acquisition board which is developed in a special, nonstandard
architecture, is also briefly presented. The main purpose of this research was
to set a coherent set of procedures in order to test all the aspects of the
video acquisition board. To accomplish this, it was necessary to set-up a
procedure in two steps: stand alone video board test (functional test) and an
in-system test procedure verifying the compatibility with both OS: Linux and
Windows. The paper presents also the results obtained using this procedure.


title:
Vibrations of liquid drops in film boiling phenomena: the mathematical
  model

abstract:
  Flattened liquid drops poured on a very hot surface evaporate quite slowly
and float on a film of their own vapour. In the cavities of a surface, an
unusual type of vibrational motions occurs. Large vibrations take place and
different forms of dynamic drops are possible. They form elliptic patterns with
two lobes or hypotrochoid patterns with three lobes or more. The lobes are
turning relatively to the hot surface. We present a model of vibrating motions
of the drops. Frequencies of the vibrations are calculated regarding the number
of lobes. The computations agree with experiments.


title: Iterated Grafting and Holonomy Lifts of Teichmueller space

abstract:
  Let $X$ be a closed hyperbolic surface and $\lambda, \eta$ be weighted
geodesic multicurves which are short on X. We show that the iterated grafting
along $\lambda$ and $\eta$ is close in the Teichmueller metric to grafting
along a single multicurve which can be given explicitly in terms of $\lambda$
and $\eta$.
  Using this result, we study the holonomy lifts $gr_{\lambda}\rho_{X,\lambda}$
of Teichmueller geodesics $\rho_{X,\lambda}$ for integral laminations $\lambda$
and show that all of them have bounded Teichmueller distance to the geodesic
$\rho_{X,\lambda}$. We obtain analogous results for grafting rays.
  Finally we consider the asymptotic behaviour of iterated grafting sequences
$\gr_{n\lambda}X$ and show that they converge geometrically to a punctured
surface.


title: Waiting Times in Simulated Stock Markets

abstract:
  Exploiting a precise reproduction of a stock exchange, the robustness of the
Continuous Double Auction (CDA) mechanism, evaluated by means of the waiting
time distributions, has been proved versus 36 different set ups made by varying
both the operators' behaviour and the market micro structure. The obtained
results demonstrate that the CDA remains able to clear strongly different order
flows, though the Milan stock exchange seemed to be a little more efficient
than the NYSE under the allocative point of view, witnessing the intrinsic
complexity of the stock market. The simulation has been built as an Agent Based
Model in order to obtain a plausible order flow. The decisions of single agents
and their interaction through the market book are realistic and reproduce some
empirical analysis results. The mentioned results have been obtained either by
the analysis of the complete pending time series and the same computation of
the asks and bids series alone.


title:
Nonperturbative deformation of D-brane states by the world sheet
  noncommutativity

abstract:
  By introducing the noncommutativity in the world sheet, we discuss a
modification of the D-brane states in the closed string theory. In particular
we show how the world sheet noncommutativity induces a nonperturbative effect
to the D-brane states.


title:
Use of Rapid Probabilistic Argumentation for Ranking on Large Complex
  Networks

abstract:
  We introduce a family of novel ranking algorithms called ERank which run in
linear/near linear time and build on explicitly modeling a network as uncertain
evidence. The model uses Probabilistic Argumentation Systems (PAS) which are a
combination of probability theory and propositional logic, and also a special
case of Dempster-Shafer Theory of Evidence. ERank rapidly generates approximate
results for the NP-complete problem involved enabling the use of the technique
in large networks. We use a previously introduced PAS model for citation
networks generalizing it for all networks. We propose a statistical test to be
used for comparing the performances of different ranking algorithms based on a
clustering validity test. Our experimentation using this test on a real-world
network shows ERank to have the best performance in comparison to well-known
algorithms including PageRank, closeness, and betweenness.


title:
Fluid-bicontinuous gels stabilized by interfacial colloids: low and high
  molecular weight fluids

abstract:
  Carefully tuned composite materials can have properties wholly unlike their
separate constituents. We review the development of one example:
colloid-stabilized emulsions with bicontinuous liquid domains. These
non-equilibrium structures resemble the sponge mesophase of surfactants;
however, in the colloid-stabilized case the interface separating the liquid
domains is itself semi-solid. The arrangement of domains is created by
arresting liquid-liquid phase separation via spinodal decomposition. Dispersed
colloids exhibiting partial wettability become trapped on the newly created
interface and jam together as the domains coarsen. Similar structures have been
created in polymer blends stabilized using either interfacial nanoparticles or
clay platelets. Here it has been possible to create the domain arrangement
either by phase separation or by direct mixing of the melt. The low
molecular-weight liquid and polymer based structures have been developed
independently and much can be learnt by comparing the two.


title:
Short-time inertial response of viscoelastic fluids measured with
  Brownian motion and with active probes

abstract:
  We have directly observed short-time stress propagation in viscoelastic
fluids using two optically trapped particles and a fast interferometric
particle-tracking technique. We have done this both by recording correlations
in the thermal motion of the particles and by measuring the response of one
particle to the actively oscillated second particle. Both methods detect the
vortex-like flow patterns associated with stress propagation in fluids. This
inertial vortex flow propagates diffusively for simple liquids, while for
viscoelastic solutions the pattern spreads super-diffusively, dependent on the
shear modulus of the medium.


title: A model of continuous time polymer on the lattice

abstract:
  In this article, we try to give a rather complete picture of the behavior of
the free energy for a model of directed polymer in a random environment, in
which the polymer is a simple symmetric random walk on the lattice $\Z^d$, and
the environment is a collection $\{W(t,x);t\ge 0, x\in \Z^d\}$ of i.i.d.
Brownian motions.


title:
From particles to spins: Eulerian formulation of supercooled liquids and
  glasses

abstract:
  The dynamics of supercooled liquid and glassy systems are usually studied
within the Lagrangian representation, in which the positions and velocities of
distinguishable interacting particles are followed. Within this representation,
however, it is difficult to define measures of spatial heterogeneities in the
dynamics, as particles move in and out of any one given region within long
enough times. It is also non-transparent how to make connections between the
structural glass and the spin glass problems within the Lagrangian formulation.
We propose an Eulerian formulation of supercooled liquids and glasses that
allows for a simple connection between particle and spin systems, and that
permits the study of dynamical heterogeneities within a fixed frame of
reference similar to the one used for spin glasses. We apply this framework to
the study of the dynamics of colloidal particle suspensions for packing
fractions corresponding to the supercooled and glassy regimes, which are probed
via confocal microscopy.


title:
Spatially-separated synchronised clocks in the same inertial frame: Time
  dilatation, but no relativity of simultaneity or length contraction

abstract:
  The Lorentz transformation is used to analyse space and time coordinates
corresponding to two spatially-separated clocks in the same inertial frame. The
time dilatation effect is confirmed, but not `relativity of simultaneity' or
`relativistic length contraction'. How these latter, spurious, effects arise
from misuse of the Lorentz transformation is also explained.


title:
Study of direct CP violation in $B^{\pm} \to J/\psi K^{\pm}(\pi^{\pm})$
  decays

abstract:
  We present a search for direct CP violation in $B^{\pm} \to J/\psi
K^{\pm}(\pi^{\pm})$ decays. The event sample is selected from 2.8 fb$^{-1}$ of
$p\bar{p}$ collisions recorded by D0 experiment in Run II of the Fermilab
Tevatron Collider. The charge asymmetry $A_{CP}(B^+ \to J/\psi K^+) = +0.0075
\pm 0.0061$(stat.)$\pm 0.0027$(syst.) is obtained using a sample of
approximately 40 thousand $B^{\pm} \to J/\psi K^{\pm}$ decays. The achieved
precision is of the same level as the expected deviation predicted by some
extensions of the standard model. We also measured the charge asymmetry
$A_{CP}(B^+ \to J/\psi \pi^+) = -0.09 \pm 0.08$(stat.)$\pm 0.03$(syst.).


title: Projective Expected Utility

abstract:
  Motivated by several classic decision-theoretic paradoxes, and by analogies
with the paradoxes which in physics motivated the development of quantum
mechanics, we introduce a projective generalization of expected utility along
the lines of the quantum-mechanical generalization of probability theory. The
resulting decision theory accommodates the dominant paradoxes, while retaining
significant simplicity and tractability. In particular, every finite game
within this larger class of preferences still has an equilibrium.


title:
Suppression of Zeeman splitting and polarization steps in localized
  exciton-polariton condensates

abstract:
  We show that the condensation of exciton-polaritons in semiconductor
microcavities in an applied magnetic field manifests itself in the quenching of
the Zeeman splitting of an elliptically polarized condensate. The circular
polarization degree of a localized condensate with a finite number of particles
increases as a function of the magnetic field with a step-like behavior. The
width of each polarization step is fixed by the polariton-polariton interaction
constants and the number of steps is fixed by the number of polaritons in the
condensate. The magnetic susceptibility of the condensate depends qualitatively
on the parity of the number of polaritons.


title:
Microwave spectral analysis by means of non-resonant parametric recovery
  of spin-wave signals in a thin magnetic film

abstract:
  We report on the storage and non-resonant parametric recovery of microwave
signals carried by a dipolar surface spin-wave pulse in a thin ferrimagnetic
film. The information about the intensity of the spectral components of the
signal within a narrow frequency band is saved due to the excitation of a
dipolar-exchange standing spin-wave mode across the film thickness and is
afterwards restored by means of parametric amplification of this mode. The
intensity of the restored signal measured for varying shifts between the signal
carrier frequency and half of the pumping frequency, which is equal to the
frequency of the standing mode, reveals information about the entire frequency
spectrum of the input microwave signal.


title: Metallicity effects on the modified wind momentum of CSPN

abstract:
  Recent investigations on the central stars of planetary nebulae (CSPN)
indicate that the masses based on model atmospheres can be much larger than the
masses derived from theoretical mass-luminosity relations. Also, the dispersion
in the relation between the modified wind momentum and the luminosity depends
on the mass spread of the CSPN, and is larger than observed in massive hot
stars. Since the wind characteristics probably depend on the metallicity, we
analyze the effects on the modified wind momentum by considering the dispersion
in this quantity caused by the stellar metallicity. Our CSPN masses are based
on a relation between the core mass and the nebular abundances. We conclude
that these masses agree with the known mass distribution both for CSPN and
white dwarfs, and that the spread in the modified wind momentum can be
explained by the observed metallicity variations.


title:
About the annual distribution of magnetically disturbed cloudless days
  and nights over Abastumani (41.75N, 42.82E)

abstract:
  The annual distribution of the planetary geomagnetic Ap index monthly mean
values on visually cloudless days and nights at the Abastumani Astrophysical
Observatory (41.75N, 42.82E) in 1957-1993 is analyzed. Cloudless days were
selected from day-time observations of the total ozone content and cloudless
nights from night-time measurements of the mesosphere-thermosphere nightglow
intensity. Both series of observations were carried out almost uninterrupted
during the referred time period. The distribution of long-term monthly mean Ap
values on cloudless days shows a semi-annual variation with maxima on the
equinoctial months (March and September), while on cloudless nights it displays
a seasonal-like character. The semi-annual and seasonal-like variations of Ap
modulate the annual distribution of long-term monthly numbers of cloudless days
with maximum in August and that of cloudless nights with maximum in September.
The lowest monthly mean Ap value for cloudless days and its highest value for
cloudless nights fall on June. Different annual distributions of long-term
monthly numbers of cloudless days and nights, when sudden storm commencements
are present, have been found. This coupling between the visually cloudless
days/nights and the magnetically disturbed days may be considered as a
manifestation of the influence of space weather/cosmic factors on the regional
and global climate.


title:
De-Rham theorem and Shapiro lemma for Schwartz functions on Nash
  manifolds

abstract:
  In this paper we continue our work on Schwartz functions and generalized
Schwartz functions on Nash (i.e. smooth semi-algebraic) manifolds. Our first
goal is to prove analogs of de-Rham theorem for de-Rham complexes with
coefficients in Schwartz functions and generalized Schwartz functions. Using
that we compute cohomologies of the Lie algebra of an algebraic group G with
coefficients in the space of generalized Schwartz sections of G-equivariant
bundle over a G-transitive variety M. We do it under some assumptions on
topological properties of G and M. This computation for the classical case is
known as Shapiro lemma.


title: The Thermodynamic Universe

abstract:
  Using Planck scale oscillators in the background dark energy in a model that
parallels the theory of phonons, we deduce the Planck mass, the elementary
particle mass scale, the mass of the Universe and a recently discovered
residual energy in the cosmic background. We also deduce the Beckenstein
temperature formula for black holes. Finally we show that the model explains
the four minute time lag in thearrival of gamma photons from a recently
observed gamma flare by the MAGIC telescope.


title:
Asymptotic behavior of weighted quadratic variations of fractional
  Brownian motion: The critical case $H=1/4$

abstract:
  We derive the asymptotic behavior of weighted quadratic variations of
fractional Brownian motion $B$ with Hurst index $H=1/4$. This completes the
only missing case in a very recent work by I. Nourdin, D. Nualart and C. A.
Tudor. Moreover, as an application, we solve a recent conjecture of K. Burdzy
and J. Swanson on the asymptotic behavior of the Riemann sums with alternating
signs associated to $B$.


title: Mathematical study of resonant wind-driven oceanic motions

abstract:
  We are interested here in describing the linear response of the ocean to some
wind forcing, which admits fast time oscillations and may be resonant with the
Coriolis force. In addition to the usual Ekman layer, we exhibit another - much
larger - boundary layer, and some global vertical profile. That means in
particular that the wind effect is no longer localized in the vicinity of the
surface. From a mathematical point of view, the main novelty here is to
introduce some systematic approach for the study of boundary effects.


title: Finsler conformal Lichnerowicz-Obata conjecture

abstract:
  We prove the Finsler analog of the conformal Lichnerowicz-Obata conjecture
showing that a complete and essential conformal vector field on a
non-Riemannian Finsler manifold is a homothetic vector field of a Minkowski
metric.


title:
A characterization of quadric constant mean curvature hypersurfaces of
  spheres

abstract:
  Let $\phi:M\to\mathbb{S}^{n+1}\subset\mathbb{R}^{n+2}$ be an immersion of a
complete $n$-dimensional oriented manifold. For any $v\in\mathbb{R}^{n+2}$, let
us denote by $\ell_v:M\to\mathbb{R}$ the function given by
$\ell_v(x)=\phi(x),v$ and by $f_v:M\to\mathbb{R}$, the function given by
$f_v(x)=\nu(x),v$, where $\nu:M\to\mathbb{S}^{n}$ is a Gauss map. We will prove
that if $M$ has constant mean curvature, and, for some $v\ne{\bf 0}$ and some
real number $\lambda$, we have that $\ell_v=\lambda f_v$, then, $\phi(M)$ is
either a totally umbilical sphere or a Clifford hypersurface. As an
application, we will use this result to prove that the weak stability index of
any compact constant mean curvature hypersurface $M^n$ in $\mathbb{S}^{n+1}$
which is neither totally umbilical nor a Clifford hypersurface and has constant
scalar curvature is greater than or equal to $2n+4$.


title:
Density structure of an active region and associated moss using
  Hinode/EIS

abstract:
  Context: Studying the problem of active region heating requires precise
measurements of physical plasma parameters such as electron density,
temperature etc. It is also important to understand the relationship of coronal
structures with the magnetic field. The Extreme-ultraviolet Imaging
Spectrometer (EIS) aboard Hinode provides a rare opportunity to derive electron
density simultaneously at different temperatures.
  Aims: MethodsWe study the density structure and characterise plasma in active
regions and associated moss regions. In addition we study its relationship to
the photospheric magnetic field.
  Methods: We used data recorded by the EIS, together with magnetic field
measurements from the Michelson Doppler Imager (MDI) aboard SoHO and images
recorded with the Transition Region And Coronal Explorer (TRACE) and X-Ray
Telescope (XRT/Hinode).
  Results: We find that the hot core of the active region is densest with
values as high as 10^10.5 cm^-3. The electron density estimated in specific
regions in the active region moss decreases with increasing temperature. The
moss areas were located primarily on one side of the active region, and they
map the positive polarity regions almost exactly. The density within the moss
region was highest at log T=5.8-6.1, with a value around 10^(10.0-10.5) cm^-3.
The moss densities were highest in the strong positive magnetic field region.
However, there was no such correlation for the negative polarity areas, where
there was a large sunspot.


title:
Closed-Orbit Theory of Spatial Density Oscillations in Finite Fermion
  Systems

abstract:
  We investigate the particle and kinetic-energy densities for $N$
non-interacting fermions confined in a local potential. Using Gutzwiller's
semi-classical Green function, we describe the oscillating parts of the
densities in terms of closed non-periodic classical orbits. We derive universal
relations between the oscillating parts of the densities for potentials with
spherical symmetry in arbitrary dimensions, and a ``local virial theorem''
valid also for arbitrary non-integrable potentials. We give simple analytical
formulae for the density oscillations in a one-dimensional potential.

categories: math-ph cond-mat.other math.MP nlin.SI nucl-th


title: Bifurcations, Schwarzian derivatives and Feigenbaum constant revisited

abstract:
  The main purpose is to show that Feigenbaum delta constant is much more
universal than believed. The paper is mainly devoted to period-doubling
processes in families in one parameter of endomorphisms of the interval and
consider generalizations of the Feigenbaum delta constant. We formulate the
so-called parenthesis permeability hypothesis, a conjecture that holds for all
types of bifurcation (i.e. for flip, fold, pitchfork and transcritical
bifurcations, which states that under some conditions two or three different
functions may have exactly the same bifurcation points.
  We propose a conjecture that considerably relaxes David Singer conditions for
endomorphism families to generate at most one stable orbit, showing that
Feigenbaum constant appears also in some classes of functions that have more
than one maximum and have positive Schwarzian in at least one sub-interval.
This version contains more arguments in favor of an even greater Feiganbaum
constant universality.


title:
On Extracting Physical Content from Asymptotically Flat Space-Time
  Metrics

abstract:
  A major issue in general relativity, from its earliest days to the present,
is how to extract physical information from any solution or class of solutions
to the Einstein equations. Though certain information can be obtained for
arbitrary solutions, e.g., via geodesic deviation, in general, because of the
coordinate freedom, it is often hard or impossible to do. Most of the time
information is found from special conditions, e.g., degenerate principle null
vectors, weak fields close to Minkowski space (using coordinates close to
Minkowski coordinates) or from solutions that have symmetries or approximate
symmetries. In the present work we will be concerned with asymptotically flat
space times where the approximate symmetry is the Bondi-Metzner-Sachs (BMS)
group. For these spaces the Bondi four-momentum vector and its evolution, found
from the Weyl tensor at infinity, describes the total energy-momentum of the
interior source and the energy-momentum radiated. By generalizing the
structures (shear-free null geodesic congruences) associated with the
algebraically special metrics to asymptotically shear-free null geodesic
congruences, which are available in all asymptotically flat space-times, we
give kinematic meaning to the Bondi four-momentum. In other words we describe
the Bondi vector and its evolution in terms of a center of mass position
vector, its velocity and a spin-vector, all having clear geometric meaning.
Among other items, from dynamic arguments, we define a unique (at our level of
approximation) total angular momentum and extract its evolution equation in the
form of a conservation law with an angular momentum flux.


title: Grids of Stellar Models and Frequencies with CLES + LOSC

abstract:
  We present a grid of stellar models, obtained with the CLES evolution code,
following the specification of ESTA-Task1, and the corresponfing seismic
properties, computed with the LOSC code. We provide a complete description of
the corresponding files that will be available on the ESTA web-pages.


title:
Negative-Parity States and beta-decays in odd Ho and Dy Nuclei with
  A=151,153

abstract:
  We have investigated the negative-parity states and electromagnetic
transitions in $^{151,153}$Ho and $^{151,153}$Dy within the framework of the
interacting boson fermion model 2 (IBFM-2). Spin assignments for some states
with uncertain spin are made based on this calculation. Calculated excitation
energies, electromagnetic transitions and branching ratios are compared with
available experimental data and a good agreement is obtained. The model wave
functions have been used to study $\beta$-decays from Ho to Dy isotones, and
the calculated $\log ft$ values are close to the experimental data.


title: Hierarchical Spherical Model from a Geometric Point of View

abstract:
  A continuous version of the hierarchical spherical model at dimension d=4 is
investigated. Two limit distribution of the block spin variable X^{\gamma},
normalized with exponents \gamma =d+2 and \gamma =d at and above the critical
temperature, are established. These results are proven by solving certain
evolution equations corresponding to the renormalization group (RG)
transformation of the O(N) hierarchical spin model of block size L^{d} in the
limit L to 1 and N to \infty . Starting far away from the stationary Gaussian
fixed point the trajectories of these dynamical system pass through two
different regimes with distinguishable crossover behavior. An interpretation of
this trajectories is given by the geometric theory of functions which describe
precisely the motion of the Lee--Yang zeroes. The large--$N$ limit of RG
transformation with L^{d} fixed equal to 2, at the criticality, has recently
been investigated in both weak and strong (coupling) regimes by Watanabe
\cite{W}. Although our analysis deals only with N=\infty case, it complements
various aspects of that work.


title: Viscosity Bound and Causality Violation

abstract:
  In recent work we showed that, for a class of conformal field theories (CFT)
with Gauss-Bonnet gravity dual, the shear viscosity to entropy density ratio,
$\eta/s$, could violate the conjectured Kovtun-Starinets-Son viscosity bound,
$\eta/s\geq1/4\pi$. In this paper we argue, in the context of the same model,
that tuning $\eta/s$ below $(16/25)(1/4\pi)$ induces microcausality violation
in the CFT, rendering the theory inconsistent. This is a concrete example in
which inconsistency of a theory and a lower bound on viscosity are correlated,
supporting the idea of a possible universal lower bound on $\eta/s$ for all
consistent theories.


title: The role of carbon grains in the deuteration of H2

abstract:
  Aims: The production of molecular hydrogen and its deuterated forms onto
carbonaceous dust grains is investigated in detail. The goal of this study is
to estimate the importance of the chemistry occuring on grain surfaces for the
deuteration of H2. Furthermore, we aim to find a robust and general surface
chemical model which can be used in different astrophysical environments.
Methods: Surface processes are described for the cases of graphitic and
amorphous--carbon grains, where laboratory work is available.
Langmuir--Hinshelwood as well as Eley--Rideal surface chemistries are included
in the model and their relative contributions are highlighted. Analytic
expressions are derived for H2, HD, and D2 formation efficiencies for both type
of grains. Rate equations are tested against stochastic methods. Results: As
expected, rate equations and stochastic methods diverge for grain sizes lower
than a critical value acrit. For grain sizes below this critical value, D2
formation decreases to favour HD formation. The formation efficiencies of H2
and D2 can be calculated by adding a correction factor to the rate equations
methods. We found that because of the presence of chemisorbed sites, which can
store atoms to form molecules up to high grain temperatures, the formation
efficiency of HD and D2 is very high compared to models where only
physisorption sites are taken into account. When considering a realistic
distribution of dust grains, we found that the formation rate of H2 and HD is
enhanced by an order of magnitude if small grains are taken into account. The
processes described in this paper, that allow a strong enhancement of the
deuterated forms of molecular hydrogen, could explain the high degree of
deuterium fractionation observed in protostellar environments.


title:
The subelliptic heat kernel on SU(2): Representations, Asymptotics and
  Gradient bounds

abstract:
  The Lie group SU(2) endowed with its canonical subriemannian structure
appears as a three-dimensional model of a positively curved subelliptic space.
The goal of this work is to study the subelliptic heat kernel on it and some
related functional inequalities.


title:
Quasinormal Modes of Charged Scalars around Dilaton Black Holes in 2+1
  Dimensions: Exact Frequencies

abstract:
  We have studied the charged scalar perturbation around a dilaton black hole
in 2 +1 dimensions. The wave equations of a massless charged scalar field is
shown to be exactly solvable in terms of hypergeometric functions. The
quasinormal frequencies are computed exactly. The relation between the
quasinormal frequencies and the charge of the black hole, charge of the scalar
and the temperature of the black hole are analyzed. The asymptotic form of the
real part of the quasinormal frequencies are evaluated exactly.


title:
Environmental limits on the non-resonant cosmic-ray current-driven
  instability

abstract:
  We investigate the so-called non-resonant cosmic-ray streaming instability,
first discussed by Bell (2004). The extent to which thermal damping and
ion-neutral collisions reduce the growth of this instability is calculated.
Limits on the growth of the non-resonant mode in SN1006 and RX J1713.7-3946 are
presented.


title: Phenomenological modeling of DNA overstretching

abstract:
  A phenomenological model based on the three-dimensional theory of nonlinear
elasticity is developed to describe the phenomenon of overstretching in the
force-extension curve for dsDNA. By using the concept of a material with
multiple reference configurations a single formula is obtained to fit the
force-extension curve.


title: Exact Solutions in Nonlocal Linear Models

abstract:
  A general class of cosmological models driven by a nonlocal scalar field
inspired by the string field theory is studied. Using the fact that the
considering linear nonlocal model is equivalent to an infinite number of local
models we have found an exact special solution of the nonlocal Friedmann
equations. This solution describes a monotonically increasing Universe with the
phantom dark energy.