title: Nuclear multifragmentation and phase transition for hot nuclei

abstract:
  This review article is focused on the tremendous progress realized during the
last fifteen years in the understanding of multifragmentation and its
relationship to the liquid-gas phase diagram of nuclei and nuclear matter. The
explosion of the whole nucleus, early predicted by Bohr [N. Bohr, Nature 137
(1936) 351], is a very complex and rich subject which continues to fascinate
nuclear physicists as well as theoreticians who extend the thermodynamics of
phase transitions to finite systems.


title: Universal convex coverings

abstract:
  In every dimension $d\ge1$, we establish the existence of a constant $v_d>0$
and of a subset $\mathcal U_d$ of $\mathbb R^d$ such that the following holds:
$\mathcal C+\mathcal U_d=\mathbb R^d$ for every convex set $\mathcal C\subset
\mathbb R^d$ of volume at least $v_d$ and $\mathcal U_d$ contains at most
$\log(r)^{d-1}r^d$ points at distance at most $r$ from the origin, for every
large $r$.


title: Geometrical properties of parafermionic spin models

abstract:
  We present measurements of the fractal dimensions associated to the
geometrical clusters for Z_4 and Z_5 spin models. We also attempted to measure
similar fractal dimensions for the generalised Fortuyin Kastelyn (FK) clusters
in these models but we discovered that these clusters do not percolate at the
critical point of the model under consideration. These results clearly mark a
difference in the behaviour of these non local objects compared to the Ising
model or the 3-state Potts model which corresponds to the simplest cases of Z_N
spin models with N=2 and N=3 respectively. We compare these fractal dimensions
with the ones obtained for SLE interfaces.


title: \'Equidistribution et diff\'erentiabilit\'e

abstract:
  We propose a criterion of equidistribution by the differentiability of
certain arithmetic invariants. Combined with the slope method and the
asymptotic measures, this criterion gives a new "conceptual" proof to
equidistribution results originally obtained via the variation principle.


title:
On the Almost Sure Central Limit Theorem for Vector Martingales:
  Convergence of Moments and Statistical Applications

abstract:
  We investigate the almost sure asymptotic properties of vector martingale
transforms. Assuming some appropriate regularity conditions both on the
increasing process and on the moments of the martingale, we prove that
normalized moments of any even order converge in the almost sure cental limit
theorem for martingales. A conjecture about almost sure upper bounds under
wider hypotheses is formulated. The theoretical results are supported by
examples borrowed from statistical applications, including linear
autoregressive models and branching processes with immigration, for which new
asymptotic properties are established on estimation and prediction errors.


title: Irreversibility, least action principle and causality

abstract:
  The least action principle, through its variational formulation, possesses a
finalist aspect. It explicitly appears in the fractional calculus framework,
where Euler-Lagrange equations obtained so far violate the causality principle.
In order to clarify the relation between those two principles, we firstly
remark that the derivatives used to described causal physical phenomena are in
fact left ones. This leads to a formal approach of irreversible dynamics, where
forward and backward temporal evolutions are decoupled. This formalism is then
integrated to the Lagrangian systems, through a particular embedding procedure.
In this set-up, the application of the least action principle leads to
distinguishing trajectories and variations dynamical status. More precisely,
when trajectories and variations time arrows are opposed, we prove that the
least action principle provides causal Euler-Lagrange equations, even in the
fractional case. Furthermore, the embedding developped is coherent.


title: Chevalley's restriction theorem for reductive symmetric superpairs

abstract:
  Let (g,k) be a reductive symmetric superpair of even type, i.e. so that there
exists an even Cartan subspace a in p. The restriction map S(p^*)^k->S(a^*)^W
where W=W(g_0:a) is the Weyl group, is injective. We determine its image
explicitly.
  In particular, our theorem applies to the case of a symmetric superpair of
group type, i.e. (k+k,k) with the flip involution where k is a classical Lie
superalgebra with a non-degenerate invariant even form (equivalently, a
finite-dimensional contragredient Lie superalgebra). Thus, we obtain a new
proof of the generalisation of Chevalley's restriction theorem due to Sergeev
and Kac, Gorelik.
  For general symmetric superpairs, the invariants exhibit a new and surprising
behaviour. We illustrate this phenomenon by a detailed discussion in the
example g=C(q+1)=osp(2|2q,C), endowed with a special involution. In this case,
the invariant algebra defines a singular algebraic curve.


title: New AdS non Abelian black holes with superconducting horizons

abstract:
  We present arguments for the existence of higher dimensional asymptotically
AdS non Abelian black holes with a Ricci flat event horizon and analyze their
basic properties. Unlike higher dimensional black holes with a curved horizon,
of the usual Einstein-Yang-Mills system, these solutions have finite
mass-energy. Below some non-zero critical temperature, they are
thermodynamically preferred over the Abelian configurations.


title: Averaged null energy condition in Loop Quantum Cosmology

abstract:
  Wormhole and time machine are very interesting objects in general relativity.
However, they need exotic matters which are impossible in classical level to
support them. But if we introduce the quantum effects of gravity into the
stress-energy tensor, these peculiar objects can be constructed
self-consistently. Fortunately, loop quantum cosmology (LQC) has the potential
to serve as a bridge connecting the classical theory and quantum gravity.
Therefore it provides a simple way for the study of quantum effect in the
semiclassical case. As is well known, loop quantum cosmology is very successful
to deal with the behavior of early universe. In the early stage, if taken the
quantum effect into consideration, inflation is natural because of the
violation of every kind of local energy conditions. Similar to the inflationary
universe, the violation of the averaged null energy condition is the necessary
condition for the traversable wormholes. In this paper, we investigate the
averaged null energy condition in LQC in the framework of effective
Hamiltonian, and find out that LQC do violate the averaged null energy
condition in the massless scalar field coupled model.


title: X-entanglement of PDC photon pairs

abstract:
  We investigate the spatio-temporal structure of the bi-photon entanglement in
parametric down-conversion (PDC) and we demonstrate its non-factorable X-shaped
geometry. Such a structure gives access to the ultra-broad bandwidth of PDC,
and can be exploited to achieve a bi-photon temporal localization in the
femtosecond range. This extreme localization is connected to our ability to
resolve the photon positions in the source near-field. The non factorability
opens the possibility of tailoring the temporal entanglement by acting on the
spatial degrees of freedom of twin photons.


title: Three generation magnetized orbifold models

abstract:
  We study three generation models in the four-dimensional spacetime, which can
be derived from the ten-dimensional N=1 super Yang-Mills theory on the orbifold
background with a non-vanishing magnetic flux. We classify the flavor
structures and show possible patterns of Yukawa matrices. Some examples of
numerical studies are also shown.


title: Spin Structure of the Nucleon - Status and Recent Results

abstract:
  After the initial discovery of the so-called "spin crisis in the parton
model" in the 1980's, a large set of polarization data in deep inelastic
lepton-nucleon scattering was collected at labs like SLAC, DESY and CERN. More
recently, new high precision data at large x and in the resonance region have
come from experiments at Jefferson Lab. These data, in combination with the
earlier ones, allow us to study in detail the polarized parton densities, the
Q^2 dependence of various moments of spin structure functions, the duality
between deep inelastic and resonance data, and the nucleon structure in the
valence quark region. Together with complementary data from HERMES, RHIC and
COMPASS, we can put new limits on the flavor decomposition and the gluon
contribution to the nucleon spin. In this report, we provide an overview of our
present knowledge of the nucleon spin structure and give an outlook on future
experiments. We focus in particular on the spin structure functions g_1 and g_2
of the nucleon and their moments.


title:
Efficient covariance estimation for asynchronous noisy high-frequency
  data

abstract:
  We focus on estimating the integrated covariance of log-price processes in
the presence of market microstructure noise. We construct an efficient unbiased
estimator for the quadratic covariation of two It\^{o} processes in the case
where high-frequency asynchronous discrete returns under market microstructure
noise are observed. This estimator is based on synchronization and multi-scale
methods and attains the optimal rate of convergence. A Monte Carlo study
analyzes the finite sample size characteristics of our estimator.


title: Long-time behavior in scalar conservation laws

abstract:
  We consider the long-time behavior of the entropy solution of a first-order
scalar conservation law on a Riemannian manifold. In the case of the Torus, we
show that, under a weak property of genuine non-linearity of the flux, the
solution converges to its average value in $L^{p}$, $1\leq p<+\infty$. We give
a partial result in the general case.


title: Estimation of the instantaneous volatility

abstract:
  This paper is concerned with the estimation of the volatility process in a
stochastic volatility model of the following form: $dX_t=a_tdt+\sigma_tdW_t$,
where $X$ denotes the log-price and $\sigma$ is a c\`adl\`ag semi-martingale.
In the spirit of a series of recent works on the estimation of the cumulated
volatility, we here focus on the instantaneous volatility for which we study
estimators built as finite differences of the \textit{power variations} of the
log-price. We provide central limit theorems with an optimal rate depending on
the local behavior of $\sigma$. In particular, these theorems yield some
confidence intervals for $\sigma_t$.


title:
Electromagnetic form factors of the nucleon: new fit and analysis of
  uncertainties

abstract:
  Electromagnetic form factors of proton and neutron, obtained from a new fit
of data, are presented. The proton form factors are obtained from a
simultaneous fit to the ratio $\mu_p G_{Ep}/G_{Mp}$ determined from
polarization transfer measurements and to $ep$ elastic cross section data.
Phenomenological two-photon exchange corrections are taken into account. The
present fit for proton was performed in the kinematical region $Q^2\in (0,6)$
GeV$^2$. Both for protons and neutrons we use the latest available data. For
all form factors the uncertainties and correlations of form factor parameters
are investigated with the $\chi^2$ method.


title: Geometry of the analytic loop group

abstract:
  We introduce and study a notion of analytic loop group with a Riemann-Hilbert
factorization relevant for the representation theory of quantum affine algebras
at roots of unity with non trivial central charge. We introduce a Poisson
structure and study properties of its Poisson dual group. We prove that the
Hopf-Poisson structure is isomorphic to the semi-classical limit of the center
of the quantum affine algebra (it is a geometric realization of the center).
Then the symplectic leaves, and corresponding equivalence classes of central
characters, are parameterized by certain G-bundles on an elliptic curve.


title: Bayesian optimal reconstruction of the primordial power spectrum

abstract:
  The form of the primordial power spectrum has the potential to differentiate
strongly between competing models of perturbation generation in the early
universe and so is of considerable importance. The recent release of five years
of WMAP observations have confirmed the general picture of the primordial power
spectrum as deviating slightly from scale invariance with a spectral tilt
parameter of n_s ~ 0.96. Nonetheless, many attempts have been made to isolate
further features such as breaks and cutoffs using a variety of methods, some
employing more than ~ 10 varying parameters. In this paper we apply the robust
technique of Bayesian model selection to reconstruct the optimal degree of
structure in the spectrum. We model the spectrum simply and generically as
piecewise linear in ln k between `nodes' in k-space whose amplitudes are
allowed to vary. The number of nodes and their k-space positions are chosen by
the Bayesian evidence so that we can identify both the complexity and location
of any detected features. Our optimal reconstruction contains, perhaps,
surprisingly few features, the data preferring just three nodes. This
reconstruction allows for a degree of scale dependence of the tilt with the
`turn-over' scale occuring around k ~ 0.016 Mpc^{-1}. More structure is
penalised by the evidence as over-fitting the data, so there is currently
little point in attempting reconstructions that are more complex.


title: Shape parameters of Galactic open clusters

abstract:
  (abridged) In this paper we derive observed and modelled shape parameters
(apparent ellipticity and orientation of the ellipse) of 650 Galactic open
clusters identified in the ASCC-2.5 catalogue. We provide the observed shape
parameters of Galactic open clusters, computed with the help of a
multi-component analysis. For the vast majority of clusters these parameters
are determined for the first time. High resolution ("star by star") N-body
simulations are carried out with the specially developed $\phi$GRAPE code
providing models of clusters of different initial masses, Galactocentric
distances and rotation velocities. The comparison of models and observations of
about 150 clusters reveals ellipticities of observed clusters which are too low
(0.2 vs. 0.3), and offers the basis to find the main reason for this
discrepancy. The models predict that after $\approx 50$ Myr clusters reach an
oblate shape with an axes ratio of $1.65:1.35:1$, and with the major axis
tilted by an angle of $q_{XY} \approx 30^\circ$ with respect to the
Galactocentric radius due to differential rotation of the Galaxy. Unbiased
estimates of cluster shape parameters require reliable membership determination
in large cluster areas up to 2-3 tidal radii where the density of cluster stars
is considerably lower than the background. Although dynamically bound stars
outside the tidal radius contribute insignificantly to the cluster mass, their
distribution is essential for a correct determination of cluster shape
parameters. In contrast, a restricted mass range of cluster stars does not play
such a dramatic role, though deep surveys allow to identify more cluster
members and, therefore, to increase the accuracy of the observed shape
parameters.


title: Hybrid multi-site excitations in dipolar condensates in optical lattices

abstract:
  Strong 1D lattices usually lead to unconnected two-dimensional gases. The
long-range character of the dipole-dipole interactions leads to a novel
scenario where non-overlapping gases at different sites may interact
significantly. We show that the excitations of non-overlapping condensates in
1D optical lattices acquire a band-like character, being collectively shared by
different sites. In particular, the hybridization of the modes significantly
enhances the rotonization of the excitations, and may induce roton-instability.
We discuss the observability of this effect in on-going experiments.


title: Thermodynamics in Loop Quantum Cosmology

abstract:
  Loop quantum cosmology (LQC) is very powerful to deal with the behavior of
early universe. And the effective loop quantum cosmology gives a successful
description of the universe in the semiclassical region. We consider the
apparent horizon of the Friedmann-Robertson-Walker universe as a
thermodynamical system and investigate the thermodynamics of LQC in the
semiclassical region. The effective density and effective pressure in the
modified Friedmann equation from LQC not only determine the evolution of the
universe in LQC scenario but are actually also found to be the thermodynamic
quantities. This result comes from the energy definition in cosmology (the
Misner-Sharp gravitational energy) and is consistent with thermodynamic laws.
We prove that within the framework of loop quantum cosmology, the elementary
equation of equilibrium thermodynamics is still valid.


title: Collective Property of Numbers and Its Mathematical Refutation

abstract:
  A number has the "collective" property if the number is the greatest lower
bound of a bounded, strictly decreasing sequence on the real line. We prove
that numbers with the collective property constitute an empty set.


title:
Sudden death and sudden birth of entanglement in common structured
  reservoirs

abstract:
  We study the exact entanglement dynamics of two qubits in a common structured
reservoir. We demonstrate that, for certain classes of entangled states,
entanglement sudden death occurs, while for certain initially factorized
states, entanglement sudden birth takes place. The backaction of the
non-Markovian reservoir is responsible for revivals of entanglement after
sudden death has occurred, and also for periods of disentanglement following
entanglement sudden birth.


title: Neutron-triton elastic scattering

abstract:
  The Kohn variational principle and the hyperspherical harmonics technique are
applied to study n-3H elastic scattering at low energies. In this contribution
the first results obtained using a non-local realistic interaction derived from
the chiral perturbation theory are reported. They are found to be in good
agreement with those obtained solving the Faddeev-Yakubovsky equations. The
calculated total and differential cross sections are compared with the
available experimental data. The effect of including a three-nucleon
interaction is also discussed.


title: Prospects for a Nuclear Optical Frequency Standard based on Thorium-229

abstract:
  The 7.6-eV-isomer of Thorium-229 offers the opportunity to perform high
resolution laser spectroscopy of a nuclear transition. We give a brief review
of the investigations of this isomer. The nuclear resonance connecting ground
state and isomer may be used as the reference of an optical clock of very high
accuracy using trapped and laser-cooled thorium ions, or in a compact
solid-state optical frequency standard of high stability.


title:
Observations of the transiting planet TrES-2 with the AIU Jena telescope
  in Gro{\ss}schwabhausen

abstract:
  We have started high precision photometric monitoring observations at the AIU
Jena observatory in Grossschwabhausen near Jena in fall 2006. We used a 25 cm
Cassegrain telescope equipped with a CCD-camera mounted picky-pack on a 90 cm
telescope. To test the obtainable photometric precision, we observed stars with
known transiting planets. We could recover all planetary transits observed by
us. We observed the parent star of the transiting planet TrES-2 over a longer
period in Grossschwabhausen. Between March and November 2007 seven different
transits and almost a complete orbital period were analyzed. Overall, in 31
nights of observation 3423 exposures (in total 57.05 h of observation) of the
TrES-2 parent star were taken. Here, we present our methods and the resulting
light curves. Using our observations we could improve the orbital parameters of
the system.


title: XML Static Analyzer User Manual

abstract:
  This document describes how to use the XML static analyzer in practice. It
provides informal documentation for using the XML reasoning solver
implementation. The solver allows automated verification of properties that are
expressed as logical formulas over trees. A logical formula may for instance
express structural constraints or navigation properties (like e.g. path
existence and node selection) in finite trees. Logical formulas can be
expressed using the syntax of XPath expressions, DTD, XML Schemas, and Relax NG
definitions.


title:
On the Cosmology of Type IIA Compactifications on SU(3)-structure
  Manifolds

abstract:
  We study cosmological properties of type IIA compactifications on
orientifolds of SU(3)-structure manifolds with non-vanishing geometric flux.
These compactifications give rise to effective 4D N=1 supergravity theories
that do not fall under some recently-proven no-go theorems against de Sitter
vacua and slow-roll inflation. Focusing on a well-understood class of models
based on coset spaces, however, we can use a refined no-go theorem that rules
out de Sitter vacua and slow-roll inflation in all but one case. The refined
no-go theorem uses the dilaton and a specific linear combination of the Kaehler
moduli, which is different from the overall volume modulus. It puts a lower
bound on the first slow-roll parameter: epsilon>=2. The only case not ruled out
is the manifold SU(2)x SU(2), for which we indeed find critical points with
epsilon numerically zero. However, all the points we could find have a tachyon
corresponding to an eta-parameter eta<= -2.4.


title:
Tachyon field in loop quantum cosmology: An example of traversable
  singularity

abstract:
  Loop quantum cosmology (LQC) predicts a nonsingular evolution of the universe
through a bounce in the high energy region. But LQC has an ambiguity about the
quantization scheme. Recently, the authors in [Phys. Rev. D 77, 124008 (2008)]
proposed a new quantization scheme. Similar to others, this new quantization
scheme also replaces the big bang singularity with the quantum bounce. More
interestingly, it introduces a quantum singularity, which is traversable. We
investigate this novel dynamics quantitatively with a tachyon scalar field,
which gives us a concrete example. Our result shows that our universe can
evolve through the quantum singularity regularly, which is different from the
classical big bang singularity. So this singularity is only a week singularity.


title: Contact resistance dependence of crossed Andreev reflection

abstract:
  We show experimentally that in nanometer scaled superconductor/normal metal
hybrid devices and in a small window of contact resistances, crossed Andreev
reflection (CAR) can dominate the nonlocal transport for all energies below the
superconducting gap. Besides CAR, elastic cotunneling (EC) and nonlocal charge
imbalance (CI) can be identified as competing subgap transport mechanisms in
temperature dependent four-terminal nonlocal measurements. We demonstrate a
systematic change of the nonlocal resistance vs. bias characteristics with
increasing contact resistances, which can be varied in the fabrication process.
For samples with higher contact resistances, CAR is weakened relative to EC in
the midgap regime, possibly due to dynamical Coulomb blockade. Gaining control
of CAR is an important step towards the realization of a solid state entangler.


title: Quasi-Local Energy in Loop Quantum Gravity

abstract:
  Although there is no known meaningful notion of the energy density of the
gravitational field in general relativity, a few notions of quasi-local energy
of gravity associated to extended but finite domains have been proposed. In
this paper, the notions of quasi-local energy are studied in the framework of
loop quantum gravity, in order to see whether these notions can be carried out
at quantum level. Two basic quasi-local geometric quantities are quantized,
which lead to well-defined operators in the kinematical Hilbert space of loop
quantum gravity. We then use them as basic building blocks to construct
different versions of quasi-local energy operators. The operators corresponding
to Brown-York energy, Liu-Yau energy, Hawking energy, and Geroch energy are
obtained respectively. The virtue of the Geroch energy operator is beneficial
for us to derive a rather general entropy-area relation and thus a holographic
principle from loop quantum gravity.


title: Sterile neutrinos at future long baseline experiments

abstract:
  In this talk we review the current status of sterile neutrino searches and
discuss the potential of future long baseline experiments to study their
properties.


title: Temperature Dependent Structure Function Of Nucleon

abstract:
  A relation between temperature, Fermi momentum and radius of the nucleon has
been derived. The percentage increase in radii of the nucleon with temperature
and the temperature dependent F$_{2}$ structure function of the nucleon have
been investigated. An estimate of the Fermi momentum of the nucleon has been
made. The results are found to be in agreement with existing theoretical and
experimental suggestions .


title: Delayed Recombination and Standard Rulers

abstract:
  Measurements of Baryonic Acoustic Oscillations in galaxy surveys have been
recognized as a powerful tool for constraining dark energy. However, this
method relies on the knowledge of the size of the acoustic horizon at
recombination derived from Cosmic Microwave Background Anisotropy measurements.
This estimate is typically derived assuming a standard recombination scheme;
additional radiation sources can delay recombination altering the cosmic
ionization history and the cosmological inferences drawn from CMB and BAO data.
In this paper we quantify the effect of delayed recombination on the
determination of dark energy parameters from future BAO surveys such as BOSS
and WFMOS. We find the impact to be small but still not negligible. In
particular, if recombination is non-standard (to a level still allowed by CMB
data), but this is ignored, future surveys may incorrectly suggest the presence
of a redshift dependent dark energy component. On the other hand, in the case
of delayed recombination, adding to the analysis one extra parameter describing
deviations from standard recombination, does not significantly degrade the
error-bars on dark energy parameters and yields unbiased estimates.


title: Generalised parton distributions at small x

abstract:
  We justify the practical use of the Shuvaev integral transform approach to
calculate the skewed distributions, needed to describe diffractive processes,
directly from the conventional diagonal global parton distributions. We address
doubts which have been raised about this procedure. We emphasise that the
approach, on the one hand, satisfies all theoretical reqirements, and, on the
other hand, is consistent with DVCS data at NLO. We construct an easily
accessible package for the computation of these skewed distributions.


title: Aging Dynamics of a Fractal Model Gel

abstract:
  Using molecular dynamics computer simulations we investigate the aging
dynamics of a gel. We start from a fractal structure generated by the DLCA-DEF
algorithm, onto which we then impose an interaction potential consisting of a
short-range attraction as well as a long-range repulsion. After relaxing the
system at T=0, we let it evolve at a fixed finite temperature. Depending on the
temperature T we find different scenarios for the aging behavior. For T>0.2 the
fractal structure is unstable and breaks up into small clusters which relax to
equilibrium. For T<0.2 the structure is stable and the dynamics slows down with
increasing waiting time. At intermediate and low T the mean squared
displacement scales as t^{2/3} and we discuss several mechanisms for this
anomalous time dependence. For intermediate T, the self-intermediate scattering
function is given by a compressed exponential at small wave-vectors and by a
stretched exponential at large wave-vectors. In contrast, for low T it is a
stretched exponential for all wave-vectors. This behavior can be traced back to
a subtle interplay between elastic rearrangements, fluctuations of chain-like
filaments, and heterogeneity.


title: Towards Low Energy Physics from the Heterotic String

abstract:
  We investigate orbifold compactifications of the heterotic string, addressing
in detail their construction, classification and phenomenological potential. We
present a strategy to search for models resembling the minimal supersymmetric
extension of the standard model (MSSM) in Z_6-II orbifold compactifications. We
find several MSSM candidates with the gauge group and the exact spectrum of the
MSSM, and supersymmetric vacua below the compactification scale. They also
exhibit the following realistic features: R-parity, seesaw suppressed neutrino
masses, and intermediate scale of supersymmetry breakdown. In addition, we find
that similar models also exist in other Z_N orbifolds and in the SO(32)
heterotic theory.


title: A classical explanation of quantization

abstract:
  In the context of our recently developed emergent quantum mechanics, and, in
particular, based on an assumed sub-quantum thermodynamics, the necessity of
energy quantization as originally postulated by Max Planck is explained by
means of purely classical physics. Moreover, under the same premises, also the
energy spectrum of the quantum mechanical harmonic oscillator is derived.
Essentially, Planck's constant h is shown to be indicative of a particle's
"zitterbewegung" and thus of a fundamental angular momentum. The latter is
identified with quantum mechanical spin, a residue of which is thus present
even in the non-relativistic Schroedinger theory.


title:
On the Infrared Problem for the Dressed Non-Relativistic Electron in a
  Magnetic Field

abstract:
  We consider a non-relativistic electron interacting with a classical magnetic
field pointing along the $x_3$-axis and with a quantized electromagnetic field.
The system is translation invariant in the $x_3$-direction and we consider the
reduced Hamiltonian $H(P_3)$ associated with the total momentum $P_3$ along the
$x_3$-axis. For a fixed momentum $P_3$ sufficiently small, we prove that
$H(P_3)$ has a ground state in the Fock representation if and only if
$E'(P_3)=0$, where $P_3 \mapsto E'(P_3)$ is the derivative of the map $P_3
\mapsto E(P_3) = \inf \sigma (H(P_3))$. If $E'(P_3) \neq 0$, we obtain the
existence of a ground state in a non-Fock representation. This result holds for
sufficiently small values of the coupling constant.


title: Questions & Answers for TEI Newcomers

abstract:
  This paper provides an introduction to the Text Encoding Initia-tive (TEI),
focused at bringing in newcomers who have to deal with a digital document
project and are looking at the capacity that the TEI environment may have to
fulfil his needs. To this end, we avoid a strictly technical presentation of
the TEI and concentrate on the actual issues that such projects face, with
parallel made on the situation within two institutions. While a quick
walkthrough the TEI technical framework is provided, the papers ends up by
showing the essential role of the community in the actual technical
contributions that are being brought to the TEI.


title: Could the photon dispersion relation be non-linear ?

abstract:
  The free photon dispersion relation is a reference quantity for high
precision tests of Lorentz Invariance. We first outline theoretical approaches
to a conceivable Lorentz Invariance Violation (LIV). Next we address
phenomenological tests based on the propagation of cosmic rays, in particular
in Gamma Ray Bursts (GRBs). As a specific concept, which could imply LIV, we
then focus on field theory in a non-commutative (NC) space, and we present
non-perturbative results for the dispersion relation of the NC photon.


title: Efficient simulation of relativistic fermions via vertex models

abstract:
  We have developed an efficient simulation algorithm for strongly interacting
relativistic fermions in two-dimensional field theories based on a formulation
as a loop gas. The loop models describing the dynamics of the fermions can be
mapped to statistical vertex models and our proposal is in fact an efficient
simulation algorithm for generic vertex models in arbitrary dimensions. The
algorithm essentially eliminates critical slowing down by sampling two-point
correlation functions and it allows simulations directly in the massless limit.
Moreover, it generates loop configurations with fluctuating topological
boundary conditions enabling to simulate fermions with arbitrary periodic or
anti-periodic boundary conditions. As illustrative examples, the algorithm is
applied to the Gross-Neveu model and to the Schwinger model in the strong
coupling limit.


title: Harmonics for Deformed Steenrod Operators

abstract:
  We explore in this paper the spaces of common zeros of several deformations
of Steenrod operators.


title:
Feshbach Resonances and Limiting Thermodynamics of Strongly Correlated
  Nucleons

abstract:
  A finite temperature model of strongly correlated nucleons with underlying
isospin symmetries is developed. The model can be used to study the role of
bound states and Feshbach resonances on the thermal properties of a spin 1/2,
isospin 1/2 system of protons and neutrons by varying the proton fraction. An
analysis of features associated with a universal thermodynamic limit or unitary
limit is given. In the limit of very large scattering length, the effective
range to quantum thermal wavelength appears as a limiting scale in an
interaction energy and equation of state.


title: Optimal filter systems for photometric redshift estimation

abstract:
  In the next years, several cosmological surveys will rely on imaging data to
estimate the redshift of galaxies, using traditional filter systems with 4-5
optical broad bands; narrower filters improve the spectral resolution, but
strongly reduce the total system throughput. We explore how photometric
redshift performance depends on the number of filters n_f, characterizing the
survey depth through the fraction of galaxies with unambiguous redshift
estimates. For a combination of total exposure time and telescope imaging area
of 270 hrs m^2, 4-5 filter systems perform significantly worse, both in
completeness depth and precision, than systems with n_f >= 8 filters. Our
results suggest that for low n_f, the color-redshift degeneracies overwhelm the
improvements in photometric depth, and that even at higher n_f, the effective
photometric redshift depth decreases much more slowly with filter width than
naively expected from the reduction in S/N. Adding near-IR observations
improves the performance of low n_f systems, but still the system which
maximizes the photometric redshift completeness is formed by 9 filters with
logarithmically increasing bandwidth (constant resolution) and half-band
overlap, reaching ~0.7 mag deeper, with 10% better redshift precision, than 4-5
filter systems. A system with 20 constant-width, non-overlapping filters
reaches only ~0.1 mag shallower than 4-5 filter systems, but has a precision
almost 3 times better, dz = 0.014(1+z) vs. dz = 0.042(1+z). We briefly discuss
a practical implementation of such a photometric system: the ALHAMBRA survey.


title: Oscillations of Rapidly Rotating Superfluid Stars

abstract:
  Using time evolutions of the relevant linearised equations we study
non-axisymmetric oscillations of rapidly rotating and superfluid neutron stars.
We consider perturbations of Newtonian axisymmetric background configurations
and account for the presence of superfluid components via the standard
two-fluid model. Within the Cowling approximation, we are able to carry out
evolutions for uniformly rotating stars up to the mass-shedding limit. This
leads to the first detailed analysis of superfluid neutron star oscillations in
the fast rotation regime, where the star is significantly deformed by the
centrifugal force. For simplicity, we focus on background models where the two
fluids (superfluid neutrons and protons) co-rotate, are in beta-equilibrium and
coexist throughout the volume of the star. We construct sequences of rotating
stars for two analytical model equations of state. These models represent
relatively simple generalisations of single fluid, polytropic stars. We study
the effects of entrainment, rotation and symmetry energy on non-radial
oscillations of these models. Our results show that entrainment and symmetry
energy can have a significant effect on the rotational splitting of
non-axisymmetric modes. In particular, the symmetry energy modifies the
inertial mode frequencies considerably in the regime of fast rotation.


title: Axial Vector Coupling and Chiral Anomaly in the Spectral Quark Model

abstract:
  We studied the Adler-Bardeen-Bell-Jackiw anomaly in the context of a finite
chiral quark model known as the Spectral Quark Model. Within this model, we
obtain the general non-local form of the axial vertex compatible with a non
vanishing axial coupling, in the chiral limit. The triangle anomaly is computed
and we show that the obtained dependence of the axial vertex with the spectral
mass is necessary to ensure both finiteness and the correct violation of the
chiral Ward-Takahashi identity.


title: Particle Identification in 4th

abstract:
  We describe 12 measurements in the 4th detector that yield particle
identification information. Seven of these have been demonstrated with test
beam data from the DREAM collaboration, one demonstrated in cosmic muon test
data, one verified in ILCroot, and the remaining three will be tested in
ILCroot. Not all are independent, but as a whole they cover all partons of the
standard model.


title:
Black holes in five-dimensional gauged supergravity with higher
  derivatives

abstract:
  We examine five-dimensional $\mathcal N=2$ gauged supergravity including
terms up to four derivatives. These additional terms correspond to the
supersymmetric completion of $R^2$, and were originally obtained in
hep-th/0611329 using conformal supergravity techniques. Here we integrate out
the auxiliary fields and obtain the on-shell action for minimal supergravity
with such corrections. We then construct $R$-charged AdS black holes to linear
order in the four derivative terms and investigate the effect of these
corrections on their thermodynamical properties. Finally, we relate the
geometrical coefficients governing the four-derivative corrections to gauge
theory data using holographic anomaly matching. This enables us to obtain a
microscopic expression for the entropy of the solutions.


title:
Formation of dynamical Schr\"odinger cats in low-dimensional ultracold
  attractive Bose gases

abstract:
  Dynamical Schr\"odinger cats can be formed when a one-dimensional attractive
Bose-gas cloud is scattered off a potential barrier. Once formed, these objects
are stable in time. The phenomenon and its mechanism -- transformation of
kinetic energy to internal energy of the scattered atomic cloud -- are obtained
by solving the time-dependent many-boson Schr\"odinger equation. Implications
are discussed.


title:
Interplay of anisotropy and frustration: triple transitions in a
  triangular-lattice antiferromagnet

abstract:
  The classical Heisenberg antiferromagnet on a triangular lattice with the
single-ion anisotropy of the easy-axis type is theoretically investigated. The
mean-field phase diagram in an external magnetic field is constructed. Three
finite-temperature Berezinskii-Kosterlitz-Thouless transitions are found by the
Monte Carlo simulations in zero field. The two upper transitions are related to
the breaking of the discrete ${\mathbb Z}_{6}$ symmetry group, while the lowest
transition is associated with a quasi-long-range ordering of transverse
components. The intermediate collinear phase between first and second
transitions is the sliding phase predicted by J. V. Jos\'e {\it et al}. [Phys.
Rev. B {\bf 16}, 1217 (1977)].


title: Charge and Spin Ordering in the Mixed Valence Compound LuFe2O4

abstract:
  Landau theory and symmetry considerations are invoked to give a unified
treatment of charge and spin ordering in the mixed valence compound LuFe2O4. In
particular, the unusual evolution of charge ordering correlations can be
explained by invoking phonon mediated interactions.


title: On the antimatter signatures of the cosmological dark matter subhalos

abstract:
  While the PAMELA collaboration has recently confirmed the cosmic ray positron
excess, it is interesting to review the effects of dark matter (DM) subhalos on
the predicted antimatter signals. We recall that, according to general subhalo
properties as inferred from theoretical cosmology, and for DM with constant
annihilation cross section, the enhancement cannot be $\gtrsim$ 20 for the
antimatter yield. This bound is obviously different from that found for
gamma-rays. We also recall some predictions for supersymmetric benchmark models
observable at the LHC and derived in the cosmological N-body framework,
illustrating in the meantime the existing discrepancy between the profiles
derived from N-body experiments and the current observations of the Milky Way.


title: Supersymmetric partners for the associated Lame potentials

abstract:
  The general solution of the stationary Schrodinger equation for the
associated Lame potentials with an arbitrary real energy is found. The
supersymmetric partners are generated by employing seeds solutions for
factorization energies inside the gaps.

categories: math-ph astro-ph hep-th math.MP quant-ph


title:
Regularization, Renormalization, and Dimensional Analysis: Dimensional
  Regularization meets Freshman E&M

abstract:
  We illustrate the dimensional regularization technique using a simple problem
from elementary electrostatics. We contrast this approach with the cutoff
regularization approach, and demonstrate that dimensional regularization
preserves the translational symmetry. We then introduce a Minimal Subtraction
(MS) and a Modified Minimal Subtraction (MS-Bar) scheme to renormalize the
result. Finally, we consider dimensional transmutation as encountered in the
case of compact extra-dimensions.


title:
Simultaneous linearization of holomorphic germs in presence of
  resonances

abstract:
  Let $f_1, ..., f_m$ be $m\ge 2$ germs of biholomorphisms of $\C^n$, fixing
the origin, with $(\d f_1)_O$ diagonalizable and such that $f_1$ commutes with
$f_h$ for any $h=2,..., m$. We prove that, under certain arithmetic conditions
on the eigenvalues of $(\d f_1)_O$ and some restrictions on their resonances,
$f_1, ..., f_m$ are simultaneously holomorphically linearizable if and only if
there exists a particular complex manifold invariant under $f_1,..., f_m$.


title:
On the transition to the normal phase for superconductors surrounded by
  normal conductors

abstract:
  For a cylindrical superconductor surrounded by a normal material, we discuss
transition to the normal phase of stable, locally stable and critical
configurations. Associated with those phase transitions, we define critical
magnetic fields and we provide a sufficient condition for which those critical
fields coincide. In particular, when the conductivity ratio of the
superconducting and the normal material is large, we show that the
aforementioned critical magnetic fields coincide, thereby proving that the
transition to the normal phase is sharp. One key-ingredient in the paper is the
analysis of an elliptic boundary value problem involving `transmission'
boundary conditions. Another key-ingredient involves a monotonicity result
(with respect to the magnetic field strength) of the first eigenvalue of a
magnetic Schroedinger operator with discontinuous coefficients.


title: A recursive approach for the finite element computation of waveguides

abstract:
  The finite element computation of structures such as waveguides can lead to
heavy computations when the length of the structure is large compared to the
wavelength. Such waveguides can in fact be seen as one-dimensional periodic
structures. In this paper a simple recursive method is presented to compute the
global dynamic stiffness matrix of finite periodic structures. This allows to
get frequency response functions with a small amount of computations. Examples
are presented to show that the computing time is of order $\log_2 N$ where $N$
is the number of periods of the waveguide.


title:
Transition to longitudinal instability of detonation waves is
  generically associated with Hopf bifurcation to time-periodic galloping
  solutions

abstract:
  We show that transition to longitudinal instability of strong detonation
solutions of reactive compressible Navier--Stokes equations is generically
associated with Hopf bifurcation to nearby time-periodic "galloping", or
"pulsating", solutions, in agreement with physical and numerical observation.
In the process, we determine readily numerically verifiable stability and
bifurcation conditions in terms of an associated Evans function, and obtain the
first complete nonlinear stability result for strong detonations of the
reacting Navier--Stokes equations, in the limit as amplitude (hence also heat
release) goes to zero. The analysis is by pointwise semigroup techniques
introduced by the authors and collaborators in previous works.


title: Unifying all classical spin models in a Lattice Gauge Theory

abstract:
  We show that the partition function of all classical spin models, including
all discrete Standard Statistical Models and all abelian discrete Lattice Gauge
Theories (LGTs), can be expressed as a special instance of the partition
function of the 4D Z_2 LGT. In this way, all classical spin models with
apparently very different features are unified in a single complete model, and
a physical relation between all models is established. As applications of this
result, we present a new method to do mean field theory for abelian discrete
LGTs with d>3, and we show that the computation of the partition function of
the 4D Z_2 LGT is a computationally hard (#P-hard) problem. We also extend our
results to abelian continuous models, where we show the approximate
completeness of the 4D Z_2 LGT. All results are proven using quantum
information techniques.


title: A Remark on Gelfand Duality for Spectral Triples

abstract:
  We present a duality between the category of compact Riemannian spin
manifolds (equipped with a given spin bundle and charge conjugation) with
isometries as morphisms and a suitable "metric" category of spectral triples
over commutative pre-C*-algebras. We also construct an embedding of a
"quotient" of the category of spectral triples introduced in
arXiv:math/0502583v1 into the latter metric category. Finally we discuss a
further related duality in the case of orientation and spin-preserving maps
between manifolds of fixed dimension.


title: Quarkyonic Matter and Chiral Symmetry Breaking

abstract:
  The appearance of a new phase of QCD, Quarkyonic Matter in the limit of large
number of colors is studied within Nambu-Jona-Lassinio effective chiral model
coupled to the Polyakov loop. The interplay of this novel QCD phase with chiral
symmetry restoration and color deconfinement is discussed. We find that at
vanishing temperature and at large $N_c$, the quarkyonic transition occurs at
densities only slightly lower than that expected for the chiral transition.
This property is also shown to be valid at finite temperature if the
temperature is less than that of deconfinement. The position and
$N_c$-dependence of chiral critical end point is also discussed.


title: Color-Octet Scalars of N=2 Supersymmetry at the LHC

abstract:
  The color gauge hyper-multiplet in N=2 supersymmetry consists of the usual
N=1 gauge vector/gaugino super-multiplet, joined with a novel gaugino/scalar
super-multiplet. Large cross sections are predicted for the production of pairs
of the color-octet scalars $\sigma$ [sgluons] at the LHC: $gg, q\bar{q} \to
\sigma\sigma^{\ast}$. Single $\sigma$ production is possible at one-loop level,
but the $g g\to \sigma$ amplitude vanishes in the limit of degenerate $L$ and
$R$ squarks. When kinematically allowed, $\sigma$ decays predominantly into two
gluinos, whose cascade decays give rise to a burst of eight or more jets
together with four LSP's as signature for $\sigma$ pair events at the LHC.
$\sigma$ can also decay into a squark-antisquark pair at tree level. At
one-loop level $\sigma$ decays into gluons or a $t \bar t$ pair are predicted,
generating exciting resonance signatures in the final states. The corresponding
partial widths are very roughly comparable to that for three body final states
mediated by one virtual squark at tree level.


title: Theory of fractional vortex escape in a 0-kappa long Josephson junction

abstract:
  We consider a fractional Josephson vortex in an infinitely long 0-kappa
Josephson junction. A uniform bias current applied to the junction exerts a
Lorentz force acting on a vortex. When the bias current becomes equal to the
critical (or depinning) current, the Lorentz force tears away an integer fluxon
and the junction switches to the resistive state. In the presence of thermal
and quantum fluctuations this escape process takes place with finite
probability already at subcritical values of the bias current. We analyze the
escape of a fractional vortex by mapping the Josephson phase dynamics to the
dynamics of a single particle in a metastable potential and derive the
effective parameters of this potential. This allows us to predict the behavior
of the escape rate as a function of the topological charge of the vortex.


title:
A multi-wavelength survey of AGN in the XMM-LSS field: I. Quasar
  selection via the KX technique

abstract:
  AIMS: We present a sample of candidate quasars selected using the
KX-technique. The data cover 0.68 deg^2 of the X-ray Multi-Mirror (XMM)
Large-Scale Structure (LSS) survey area where overlapping multi-wavelength
imaging data permits an investigation of the physical nature of selected
sources. METHODS: The KX method identifies quasars on the basis of their
optical (R and z') to near-infrared (Ks) photometry and point-like morphology.
We combine these data with optical (u*,g'r',i',z') and mid-infrared (3.6-24
micron) wavebands to reconstruct the spectral energy distributions (SEDs) of
candidate quasars. RESULTS: Of 93 sources selected as candidate quasars by the
KX method, 25 are classified as quasars by the subsequent SED analysis.
Spectroscopic observations are available for 12/25 of these sources and confirm
the quasar hypothesis in each case. Even more, 90% of the SED-classified
quasars show X-ray emission, a property not shared by any of the false
candidates in the KX-selected sample. Applying a photometric redshift analysis
to the sources without spectroscopy indicates that the 25 sources classified as
quasars occupy the interval 0.7 < z < 2.5. The remaining 68/93 sources are
classified as stars and unresolved galaxies.


title:
Shear Flows Driven by the Lorentz Force: An Energy Source for Coronal
  Mass Ejections and Flares

abstract:
  Shear flows have been prescribed in numerical models of coronal mass
ejections and flares for decades as a way of energizing magnetic fields to
erupt. While such shear flows have long been observed in the solar atmosphere,
until recently, there was no compelling physical explanation for them. This
paper will discuss the discovery that such shear flows are readily explained as
a response to the Lorentz force that naturally occurs as bipolar magnetic
fields emerge and expand in a gravitationally stratified atmosphere. It will be
shown that shearing motions transport axial flux, and magnetic energy from the
submerged portion of the field to the expanding portion, strongly coupling the
solar interior to the corona. This physical process explains active region
shear flows and why the magnetic field is found to be nearly parallel to
photospheric polarity inversion lines where prominences form. Finally, shear
flows driven by the Lorentz force are shown to produce a loss of equilibrium
and eruption in magnetic arcades and flux ropes offering a convincing
explanation for CMEs and flares.


title:
Macroscopic quantum effects generated by the acoustic wave in a
  molecular magnet

abstract:
  We have shown that the size of the magnetization step due to resonant spin
tunneling in a molecular magnet can be strongly affected by sound. The
transverse acoustic wave can also generate macroscopic quantum beats of the
magnetization during the field sweep.


title: How to make a fragile network robust and vice versa

abstract:
  We investigate topologically biased failure in scale-free networks with
degree distribution $P(k) \propto k^{-\gamma}$. The probability $p$ that an
edge remains intact is assumed to depend on the degree $k$ of adjacent nodes
$i$ and $j$ through $p_{ij}\propto(k_{i}k_{j})^{-\alpha}$. By varying the
exponent $\alpha$, we interpolate between random ($\alpha=0$) and systematic
failure. For $\alpha >0 $ ($<0$) the most (least) connected nodes are
depreciated first. This topological bias introduces a characteristic scale in
$P(k)$ of the depreciated network, marking a crossover between two distinct
power laws. The critical percolation threshold, at which global connectivity is
lost, depends both on $\gamma$ and on $\alpha$. As a consequence, network
robustness or fragility can be controlled through fine tuning of the
topological bias in the failure process.


title: Semi log resolution

abstract:
  The aim of this note is to discuss resolution theorems that are useful in the
study of semi log canonical varieties.


title:
A randomized polynomial-time algorithm for the Spanning Hypertree
  Problem on 3-uniform hypergraphs

abstract:
  Consider the problem of determining whether there exists a spanning hypertree
in a given k-uniform hypergraph. This problem is trivially in P for k=2, and is
NP-complete for k>= 4, whereas for k=3, there exists a polynomial-time
algorithm based on Lovasz' theory of polymatroid matching. Here we give a
completely different, randomized polynomial-time algorithm in the case k=3. The
main ingredients are a Pfaffian formula by Vaintrob and one of the authors
(G.M.) for a polynomial that enumerates spanning hypertrees with some signs,
and a lemma on the number of roots of polynomials over a finite field.


title: Minimal Flavor Violation and the Scale of Supersymmetry Breaking

abstract:
  In this paper we explore the constraints from B-physics observables in SUSY
models of Minimal Flavor Violation, in the large tan beta regime, for both low
and high scale supersymmetry breaking scenarios. We find that the rare B-decays
b -> s gamma and B_s -> mu+ mu- can be quite sensitive to the scale M at which
supersymmetry breaking is communicated to the visible sector. In the case of
high scale supersymmetry breaking, we show that the additional gluino
contribution to the b -> s gamma and B_s -> mu+ mu- rare decay rates can be
significant for large tan beta, mu and M_3. The constraints on B_u -> tau nu
are relatively insensitive to the precise scale of M. We also consider the
additional constraints from the present direct Higgs searches at the Tevatron
in the inclusive H/A -> tau tau channel, and the latest CDMS direct dark matter
detection experiments. We find that altogether the constraints from B-physics,
Higgs physics and direct dark matter searches can be extremely powerful in
probing regions of SUSY parameter space for low M_A and large tan beta, leading
to a preference for models with a lightest CP-even Higgs mass close to the
current experimental limit. We find interesting regions of parameter space that
satisfy all constraints and can be probed by Higgs searches at the Tevatron and
the LHC and by direct dark matter searches in the near future.


title:
Modular application of an Integration by Fractional Expansion (IBFE)
  method to multiloop Feynman diagrams II

abstract:
  A modular application of the integration by fractional expansion (IBFE)
method for evaluating Feynman diagrams is extended to diagrams that contain
loop triangle subdiagrams in their geometry. The technique is based in the
replacement of this module or subdiagram by its corresponding multiregion
expansion (MRE), which in turn is obtained from Schwinger's parametric
representation of the diagram. The result is a topological reduction,
transforming the triangular loop into an equivalent vertex, which simplifies
the search for the MRE of the complete diagram. This procedure has important
advantages with respect to considering the parametric representation of the
whole diagram: the obtained MRE is reduced and the resulting hypergeometric
series tend to have smaller multiplicity.


title: A Spectral Theorem for Imprimitivity C*-bimodules

abstract:
  After recalling in detail some basic definitions on Hilbert C*-bimodules,
Morita equivalence and imprimitivity, we discuss a spectral reconstruction
theorem for imprimitivity Hilbert C*-bimodules over commutative unital
C*-algebras and consider some of its applications in the theory of commutative
full C*-categories.


title:
How Colors Influence Numbers: Photon Statistics of Parametric
  Downconversion

abstract:
  Parametric downconversion (PDC) is a technique of ubiquitous experimental
significance in the production of non-classical, photon-number correlated twin
beams. Standard theory of PDC as a two-mode squeezing process predicts and
homodyne measurements observe a thermal photon number distribution per beam.
Recent experiments have obtained conflicting distributions. In this paper, we
explain the observation by an a-priori theoretical model solely based on
directly accessible physical quantities. We compare our predictions with
experimental data and find excellent agreement.


title:
The origin of the diffuse non-thermal X-ray and radio emission in the
  Ophiuchus cluster of galaxies

abstract:
  We present high resolution 240 and 607 MHz GMRT radio observations,
complemented with 74 MHz archival VLA radio observations of the Ophiuchus
cluster of galaxies, whose radio mini-halo has been recently detected at 1400
MHz. We also present archival Chandra and XMM-Newton data of the Ophiuchus
cluster. Our observations do not show significant radio emission from the
mini-halo, hence we present upper limits to the integrated, diffuse non-thermal
radio emission of the core of the Ophiuchus cluster. The XMM-Newton
observations can be well explained by a two-temperature thermal model with
temperatures of ~=1.8 keV and ~=9.0 keV, respectively, which confirms previous
results that suggest that the innermost central region of the Ophiuchus cluster
is a cooling core. We also used the XMM-Newton data to set up an upper limit to
the (non-thermal) X-ray emission from the cluster.
  The combination of available radio and X-ray data has strong implications for
the currently proposed models of the spectral energy distribution (SED) from
the Ophiuchus cluster. In particular, a synchrotron+IC model is in agreement
with the currently available data, if the average magnetic field is in the
range (0.02-0.3) microG. A pure WIMP annihilation scenario can in principle
reproduce both radio and X-ray emission, but at the expense of postulating very
large boost factors from dark matter substructures, jointly with extremely low
values of the average magnetic field. Finally, a scenario where synchrotron and
inverse Compton emission arise from PeV electron-positron pairs (via
interactions with the CMB), can be ruled out, as it predicts a non-thermal soft
X-ray emission that largely exceeds the thermal Bremsstrahlung measured by
INTEGRAL.


title:
A Double-Transition Scenario for Anomalous Diffusion in Glass-Forming
  Mixtures

abstract:
  We study by molecular dynamics computer simulation a binary soft-sphere
mixture that shows a pronounced decoupling of the species' long-time dynamics.
Anomalous, power-law-like diffusion of small particles arises, that can be
understood as a precursor of a double-transition scenario, combining a glass
transition and a separate small-particle localization transition. Switching off
small-particle excluded-volume constraints slows down, rather than enhances,
small-particle transport. The data are contrasted with results from the
mode-coupling theory of the glass transition.


title:
On the connection of the generalized nonlinear sigma model with
  constrained stochastic dynamics

abstract:
  The dynamics of a freely jointed chain in the continuous limit is described
by a field theory which closely resembles the nonlinear sigma model. The
generating functional $\Psi[J]$ of this field theory contains nonholonomic
constraints, which are imposed by inserting in the path integral expressing
$\Psi[J]$ a suitable product of delta functions. The same procedure is commonly
applied in statistical mechanics in order to enforce topological conditions on
a system of linked polymers. The disadvantage of this method is that the
contact with the stochastic process governing the diffusion of the chain is
apparently lost. The main goal of this work is to reestablish this contact. To
this purpose, it is shown here that the generating functional $\Psi[J]$
coincides with the generating functional of the correlation functions of the
solutions of a constrained Langevin equation. In the discrete case, this
Langevin equation describes as expected the Brownian motion of beads connected
together by links of fixed length.


title: A Horizontal Categorification of Gelfand Duality

abstract:
  In the setting of C*-categories, we provide a definition of "spectrum" of a
commutative full C*-category as a one-dimensional unital saturated Fell bundle
over a suitable groupoid (equivalence relation) and prove a categorical Gelfand
duality theorem generalizing the usual Gelfand duality between the categories
of commutative unital C*-algebras and compact Hausdorff spaces.
  Although many of the individual ingredients that appear along the way are
well-known, the somehow unconventional way we "glue" them together seems to
shed some new light on the subject.


title: High Energy Resummation of Drell-Yan Processes

abstract:
  We present a computation of the inclusive Drell-Yan production cross-section
in perturbative QCD to all orders in the limit of high partonic centre-of-mass
energy. We compare our results to the fixed order NLO and NNLO results in MSbar
scheme, and provide predictions at NNNLO and beyond. Our expressions may be
used to obtain fully resummed results for the inclusive cross-section.


title: Motion of a "small body" in non-metric gravity

abstract:
  We describe "small bodies" in a non-metric gravity theory previously studied
by this author. The main dynamical field of the theory is a certain triple of
two-forms rather than the metric, with only the spacetime conformal structure,
not metric, being canonically defined. The theory is obtained from general
relativity (GR) in Plebanski formulation by adding to the action a certain
potential. Importantly, the modification does not change the number of
propagating degrees of freedom as compared to GR. We find that "small bodies"
move along geodesics of a certain metric that is constructed with the help of a
new potential function that appears in the matter sector. We then use the
"small body" results to formulate a prescription for coupling the theory to
general stress-energy tensor. In its final formulation the theory takes an
entirely standard form, with matter propagating in a metric background and only
the matter-gravity coupling and the gravitational dynamics being modified. This
completes the construction of the theory and opens way to an analysis of its
physical predictions.


title: Density Matrix Functional Theory for the Lipkin model

abstract:
  A Density Matrix Functional theory is constructed semi-empirically for the
two-level Lipkin model. This theory, based on natural orbitals and occupation
numbers, is shown to provide a good description for the ground state energy of
the system as the two-body interaction and particle number vary. The
application of Density Matrix Functional theory to the Lipkin model illustrates
that it could be a valuable tool for systems presenting a shape
phase-transition such as nuclei. The improvement of one-body observables
description as well as the interest for Energy Density Functional theory are
discussed.


title:
Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal
  junctions

abstract:
  We have fabricated c-axis Josephson junctions on single crystals of
(Ba,K)Fe2As2 by using Pb as the counter electrode in two geometries, planar and
point contact. Junctions in both geometries show resistively shunted junction
I-V curves below the Tc of the counter electrode. Microwave induced steps were
observed in the I-V curves, and the critical currents are suppressed with an
in-plane magnetic field in a manner consistent with the small junction limit.
ICRN products of up to 0.3 mV have been observed in these junctions at 4.2 K.
The observation of Josephson coupling along the c-axis between (Ba,K)Fe2As2 and
a conventional superconductor suggests the existence of a s-wave
superconducting order parameter in this class of iron pnictide superconductors.


title:
Fully discrete Galerkin schemes for the nonlinear and nonlocal Hartree
  equation

abstract:
  We study the time dependent Hartree equation in the continuum, the
semidiscrete, and the fully discrete setting. We prove existence-uniqueness,
regularity, and approximation properties for the respective schemes, and set
the stage for a controlled numerical computation of delicate nonlinear and
nonlocal features of the Hartree dynamics in various physical applications.


title: Symmetric extension in two-way quantum key distribution

abstract:
  We introduce symmetric extensions of bipartite quantum states as a tool for
analyzing protocols that distill secret key from quantum correlations. Whether
the correlations are coming from a prepare-and-measure quantum key distribution
scheme or from an entanglement-based scheme, the protocol has to produce
effective states without a symmetric extension in order to succeed. By
formulating the symmetric extension problem as a semidefinite program, we solve
the problem for Bell-diagonal states. Applying this result to the six-state and
BB84 schemes, we show that for the entangled states that cannot be distilled by
current key distillation procedures, the failure can be understood in terms of
a failure to break a symmetric extension.


title: Quotients by finite equivalence relations

abstract:
  This note studies the existence of quotients by finite set theoretic
equivalence relations.
  May 18: Substantial revisions with a new appendix by C. Raicu


title:
Mesoscopic Spin-Hall Effect in 2D electron systems with smooth
  boundaries

abstract:
  Spin-Hall effect in ballistic 2D electron gas with Rashba-type spin-orbit
coupling and smooth edge confinement is studied. We predict that the interplay
of semiclassical electron motion and quantum dynamics of spins leads to several
distinct features in spin density along the edge that originate from
accumulation of turning points from many classical trajectories. Strong peak is
found near a point of the vanishing of electron Fermi velocity in the lower
spin-split subband. It is followed by a strip of negative spin density that
extends until the crossing of the local Fermi energy with the degeneracy point
where the two spin subbands intersect. Beyond this crossing there is a wide
region of a smooth positive spin density. The total amount of spin accumulated
in each of these features exceeds greatly the net spin across the entire edge.
The features become more pronounced for shallower boundary potentials,
controlled by gating in typical experimental setups.


title: Hierarchical Soft Terms and Flavor Physics

abstract:
  We study the framework of hierarchical soft terms, in which the first two
generations of squarks and sleptons are heavier than the rest of the
supersymmetric spectrum. This scheme gives distinctive predictions for the
pattern of flavor violations, which we compare to the case of nearly degenerate
squarks. Experiments in flavor physics have started to probe the most
interesting parameter region, especially in $b\leftrightarrow s$ transitions,
where hierarchical soft terms can predict a phase of $B_s$ mixing much larger
than in the Standard Model.


title: Dark Energy vs. Dark Matter: Towards a Unifying Scalar Field?

abstract:
  The standard model of cosmology suggests the existence of two components,
"dark matter" and "dark energy", which determine the fate of the Universe.
Their nature is still under investigation, and no direct proof of their
existences has emerged yet. There exist alternative models which reinterpret
the cosmological observations, for example by replacing the dark energy/dark
matter hypothesis by the existence of a unique dark component, the dark fluid,
which is able to mimic the behaviour of both components. After a quick review
of the cosmological constraints on this unifying dark fluid, we will present a
model of dark fluid based on a complex scalar field and discuss the problem of
the choice of the potential.


title:
Bias correction in a multivariate normal regression model with general
  parameterization

abstract:
  This paper develops a bias correction scheme for a multivariate normal model
under a general parameterization. In the model, the mean vector and the
covariance matrix share the same parameters. It includes many important
regression models available in the literature as special cases, such as
(non)linear regression, errors-in-variables models, and so forth. Moreover,
heteroscedastic situations may also be studied within our framework. We derive
a general expression for the second-order biases of maximum likelihood
estimates of the model parameters and show that it is always possible to obtain
the second order bias by means of ordinary weighted lest-squares regressions.
We enlighten such general expression with an errors-in-variables model and also
conduct some simulations in order to verify the performance of the corrected
estimates. The simulation results show that the bias correction scheme yields
nearly unbiased estimators. We also present an empirical ilustration.


title: Stochastic Vs Worst-case Condition Numbers

abstract:
  We compare Stochastic and Worst-case condition numbers and loss of precision
for general computational problems. We show an upper bound for the ratio of
Worst-case condition number to the Stochastic condition number of order O(sqrt
m). We show an upper bound for the difference between the Worst-case loss of
precision and the Stochastic loss of precision of order O(ln m). The results
hold if the perturbations are measured norm-wise or componentwise.


title:
Proposal to improve the behaviour of self-energy contributions to the
  S-matrix

abstract:
  A simple modification of the definition of the S-matrix is proposed. It is
expected that the divergences related to nonzero self-energies are considerably
milder with the modified definition than with the usual one. This conjecture is
verified in a few examples using perturbation theory. The proposed formula is
written in terms of the total Hamiltonian operator and a free Hamiltonian
operator and is therefore applicable in any case when these Hamiltonian
operators are known.


title:
Unfolding Mixed-Symmetry Fields in AdS and the BMV Conjecture: I.
  General Formalism

abstract:
  We present some generalities of unfolded on-shell dynamics that are useful in
analysing the BMV conjecture for mixed-symmetry fields in constantly curved
backgrounds. In particular we classify the Lorentz-covariant Harish-Chandra
modules generated from primary Weyl tensors of arbitrary mass and shape, and in
backgrounds with general values of the cosmological constant. We also discuss
the unfolded notion of local degrees of freedom in theories with and without
gravity and with and without massive deformation parameters, using the language
of Weyl zero-form modules and their duals.


title: Nonlocal Gluon Condensate from the Dyson--Schwinger Equations

abstract:
  We establish a novel method of obtaining the gauge-invariant bilocal
condensate of gluon fields from the solutions of the Dyson--Schwinger equations
(DSE) which works in the infrared and ultraviolet limits. We present explicit
results for SU(3) case in four dimensions, and compare to other related
analytical and lattice results.


title: Center symmetry and the orientifold planar equivalence

abstract:
  We study the center symmetry of SU(N) gauge theories with fermions in the
two-index representations, by computing the effective potential of the Polyakov
loop in the large-mass expansion on the lattice. In the large-N limit and at
non-zero temperature, we find that the center symmetry is Z_N for fermions in
the adjoint representation and just Z_2 for fermions in the (anti)symmetric
representation. We discuss the fact that our results do not contradict the
orientifold planar equivalence, which relates a common sector defined by the
bosonic gauge-invariant C-even states of theories with fermions in different
two-index representations. Our results complement the work of Armoni et al.
(2007), who showed how at zero temperature a Z_N center symmetry is dynamically
recovered also for fermions in the (anti)symmetric representation, by
considering the theories at finite temperature.


title: Hydrodynamics of confined colloidal fluids in two dimensions

abstract:
  We apply a hybrid Molecular Dynamics and mesoscopic simulation technique to
study the dynamics of two dimensional colloidal discs in confined geometries.
We calculate the velocity autocorrelation functions, and observe the predicted
$t^{-1}$ long time hydrodynamic tail that characterizes unconfined fluids, as
well as more complex oscillating behavior and negative tails for strongly
confined geometries. Because the $t^{-1}$ tail of the velocity autocorrelation
function is cut off for longer times in finite systems, the related diffusion
coefficient does not diverge, but instead depends logarithmically on the
overall size of the system.


title:
On the annealed large deviation rate function for a multi-dimensional
  random walk in random environment

abstract:
  We derive properties of the rate function in Varadhan's (annealed) large
deviation principle for multidimensional, ballistic random walk in random
environment, in a certain neighborhood of the zero set of the rate function.
Our approach relates the LDP to that of regeneration times and distances. The
analysis of the latter is possible due to the i.i.d. structure of
regenerations.


title:
Transmission thresholds in time-periodically driven nonlinear disordered
  systems

abstract:
  We study energy propagation in locally time-periodically driven disordered
nonlinear chains. For frequencies inside the band of linear Anderson modes,
three different regimes are observed with increasing driver amplitude: 1) Below
threshold, localized quasiperiodic oscillations and no spreading; 2) Three
different regimes in time close to threshold, with almost regular oscillations
initially, weak chaos and slow spreading for intermediate times, and finally
strong diffusion; 3) Immediate spreading for strong driving. The thresholds are
due to simple bifurcations, obtained analytically for a single oscillator, and
numerically as turning-points of the nonlinear response manifold for a full
chain. Generically, the threshold is nonzero also for infinite chains.

categories: nlin.PS cond-mat.dis-nn nlin.CD physics.optics


title: Mass Loss by X-ray Winds from Active Galactic Nuclei

abstract:
  We consider a sample of type-I active galactic nuclei (AGN) that were
observed by Chandra/HETG and resulted in high signal-to-noise grating spectra,
which we study in detail. All objects show signatures for very high ionization
outflows. Using a novel scheme to model the physics and spectral signatures of
gaseous winds from these objects, we are able to estimate the mass loss rates
and kinetic luminosities associated with the highly ionized gas and investigate
its physical properties. Our conclusions are as follows: 1) There is a strong
indication that the outflowing gas in those objects is multi-phase with similar
kinematics for the different phases. 2) The X-ray spectrum is consistent with
such flows being thermally driven from ~pc scales, and are therefore unlikely
to be associated with the inner accretion disk. 3) The underlying X-ray
spectrum consists of a hard X-ray powerlaw which is similar for all objects
shining below their Eddington rate and a soft excess whose contribution becomes
more prominent for objects shining close to their Eddington limit. 4) The
physical properties of the outflow are similar in all cases and a coherent
picture emerges concerning its physical properties. 5) The deduced mass loss
rates are, roughly, of the order of the mass accretion rate in those objects so
that the kinetic luminosity carried by such winds is only a tiny fraction
(<<1%) of the bolometric luminosity. We discuss the implications of our results
for AGN structure and AGN interaction with the environment.


title: On initial conditions for the Hot Big Bang

abstract:
  We analyse the process of reheating the Universe in the electroweak theory
where the Higgs field plays a role of the inflaton. We estimate the maximal
temperature of the Universe and fix the initial conditions for
radiation-dominated phase of the Universe expansion in the framework of the
Standard Model (SM) and of the nuMSM -- the minimal extension of the SM by
three right-handed singlet fermions. We show that the inflationary epoch is
followed by a matter dominated stage related to the Higgs field oscillations.
We investigate the energy transfer from Higgs-inflaton to the SM particles and
show that the radiation dominated phase of the Universe expansion starts at
temperature T_r~(3-15)*10^{13} GeV, where the upper bound depends on the Higgs
boson mass. We estimate the production rate of singlet fermions at preheating
and find that their concentrations at T_r are negligibly small. This suggests
that the sterile neutrino Dark Matter (DM) production and baryogenesis in the
nuMSM with Higgs-driven inflation are low energy phenomena, having nothing to
do with inflation. We study then a modification of the nuMSM, adding to its
Lagrangian higher dimensional operators suppressed by the Planck scale. The
role of these operators in Higgs-driven inflation is clarified. We find that
these operators do not contribute to the production of Warm Dark Matter (WDM)
and to baryogenesis. We also demonstrate that the sterile neutrino with mass
exceeding 100 keV (a Cold Dark Matter (CDM) candidate) can be created during
the reheating stage of the Universe in necessary amounts. We argue that the
mass of DM sterile neutrino should not exceed few MeV in order not to overclose
the Universe.


title: Bulk viscosity of N=2* plasma

abstract:
  We use gauge theory/string theory correspondence to study the bulk viscosity
of strongly coupled, mass deformed SU(N_c) N=4 supersymmetric Yang-Mills
plasma, also known as N=2^* gauge theory. For a wide range of masses we confirm
the bulk viscosity bound proposed in arXiv:0708.3459. For a certain choice of
masses, the theory undergoes a phase transition with divergent specific heat
c_V ~ |1-T_c/T|^(-1/2). We show that, although bulk viscosity rapidly grows as
T -> T_c, it remains finite in the vicinity of the critical point.


title:
Simulating star formation in molecular cloud cores IV. The role of
  turbulence and thermodynamics

abstract:
  We perform SPH simulations of the collapse and fragmentation of low-mass
cores having different initial levels of turbulence
(alpha_turb=0.05,0.10,0.25). We use a new treatment of the energy equation
which captures the transport of cooling radiation against opacity due to both
dust and gas (including the effects of dust sublimation, molecules, and H^-
ions). We also perform comparison simulations using a standard barotropic
equation of state. We find that -- when compared with the barotropic equation
of state -- our more realistic treatment of the energy equation results in more
protostellar objects being formed, and a higher proportion of brown dwarfs; the
multiplicity frequency is essentially unchanged, but the multiple systems tend
to have shorter periods (by a factor ~3), higher eccentricities, and higher
mass ratios. The reason for this is that small fragments are able to cool more
effectively with the new treatment, as compared with the barotropic equation of
state. We find that the process of fragmentation is often bimodal. The first
protostar to form is usually, at the end, the most massive, i.e. the primary.
However, frequently a disc-like structure subsequently forms round this
primary, and then, once it has accumulated sufficient mass, quickly fragments
to produce several secondaries. We believe that this delayed fragmentation of a
disc-like structure is likely to be an important source of very low-mass
hydrogen-burning stars and brown dwarfs.


title:
Modular application of an Integration by Fractional Expansion (IBFE)
  method to multiloop Feynman diagrams

abstract:
  We present an alternative technique for evaluating multiloop Feynman
diagrams, using the integration by fractional expansion method. Here we
consider generic diagrams that contain propagators with radiative corrections
which topologically correspond to recursive constructions of bubble type
diagrams. The main idea is to reduce these subgraphs, replacing them by their
equivalent multiregion expansion. One of the main advantages of this
integration technique is that it allows to reduce massive cases with the same
degree of difficulty as in the massless case.


title: Tightened Lieb-Oxford bound for systems of fixed particle number

abstract:
  The Lieb-Oxford bound is a constraint upon approximate exchange-correlation
functionals. We explore a non-empirical tightening of that bound in both
universal and electron-number-dependent form. The test functional is PBE.
Regarding both atomization energies (slightly worsened) and bond lengths
(slightly bettered), we find the PBE functional to be remarkably insensitive to
the value of the Lieb-Oxford bound. This both rationalizes the use of the
original Lieb-Oxford constant in PBE and suggests that enhancement factors more
sensitive to sharpened constraints await discovery.


title:
Bulk-mediated surface diffusion on a cylinder: propagators and
  crossovers

abstract:
  We consider the effective surface motion of a particle that freely diffuses
in the bulk and intermittently binds to that surface. From an exact approach we
derive various regimes of the effective surface motion characterized by
physical rates for binding/unbinding and the bulk diffusivity. We obtain a
transient regime of superdiffusion and, in particular, a saturation regime
characteristic for the cylindrical geometry. This saturation, however, in a
finite system is not terminal but eventually turns over to normal surface
diffusion. The first passage behavior of particles to the cylinder surface is
derived. Consequences for actual systems are discussed.


title: Inflation and The Minimal Supersymmetric Standard Model

abstract:
  There is strong evidence from cosmological data that the universe underwent
an epoch of superluminal expansion called inflation. A satisfactory embedding
of inflation in fundamental physics has been an outstanding problem at the
interface of cosmology and high energy physics. We show how inflation can be
realized within the Minimal Supersymmetric Standard Model (MSSM). The inflaton
candidates are two specific combinations of supersymmetric partners of quarks
and leptons. MSSM inflation occurs at a low scale and generates perturbations
in the range experimentally allowed by the latest data from Wilkinson Microwave
Anisotropy Probe (WMAP). The parameter space for inflation is compatible with
supersymmetric dark matter, and the Large Hadron Collider (LHC) is capable of
discovering the inflaton candidates in the allowed regions of parameter space.


title: The Stress-Energy Tensor of Flavor Fields from AdS/CFT

abstract:
  We use the AdS/CFT correspondence to study the transport properties of
massive N=2 hypermultiplet fields in an N=4 SU(Nc) super-Yang-Mills theory
plasma in the large Nc, large 't Hooft coupling limit, and in the presence of a
baryon number chemical potential and external electric and magnetic fields. In
particular, we compute the flavor fields' contribution to the stress-energy
tensor. We find infrared divergences in the stress-energy tensor, arising from
the flavor fields' constant rate of energy and momentum loss. We regulate these
divergences and extract the energy and momentum loss rates from the divergent
terms. We also check our result in various limits in which the divergences are
absent. The supergravity dual is a system of D7-branes, with a particular
configuration of worldvolume fields, probing an AdS-Schwarzschild background.
The supergravity calculation amounts to computing the stress-energy tensor of
the D7-branes.


title: Hybrid 2D surface trap for quantum simulation

abstract:
  We demonstrate a novel optical trapping scheme for ultracold atoms. Using a
combination of evanescent wave, standing wave, and magnetic potentials we
create a deeply 2D Bose-Einstein condensate (BEC) at a few microns from a glass
surface. Using techniques such as broadband "white" light to create evanescent
and standing waves, we realize a smooth potential with a trap frequency aspect
ratio of 300:1:1 and long lifetimes. This makes the setup suitable for
many-body quantum simulations and applications such as high precision
measurements close to surfaces.


title: A remark on a conjecture of Hain and Looijenga

abstract:
  After recalling the various tautological algebras of the moduli space of
curves and some of its partial compactifications and stating several well-known
results and conjectures concerning these algebras, we prove that the natural
extension to the case of pointed curves of a 1996 conjecture of Hain and
Looijenga is true if and only if two of the stated conjectures are true.


title:
Optimal detection of homogeneous segment of observations in stochastic
  sequence

abstract:
  A Markov process is registered. At random moment $\theta$ the distribution of
observed sequence changes. Using probability maximizing approach the optimal
stopping rule for detecting the change is identified. Some explicit solution is
obtained.


title: Two Loop R-Symmetry Breaking

abstract:
  We analyze two loop quantum corrections for pseudomoduli in O'Raifeartaigh
like models. We argue that R-symmetry can be spontaneously broken at two loop
in non supersymmetric vacua. We provide a basic example with this property. We
discuss on phenomenological applications.


title: Thermal rectification in nonlinear quantum circuits

abstract:
  We present a theoretical study of radiative heat transport in nonlinear
solid-state quantum circuits. We give a detailed account of heat rectification
effects, i.e. the asymmetry of heat current with respect to a reversal of the
thermal gradient, in a system consisting of two reservoirs at finite
temperatures coupled through a nonlinear resonator. We suggest an
experimentally feasible superconducting circuit employing the Josephson
nonlinearity to realize a controllable low temperature heat rectifier with a
maximal asymmetry of the order of 10%. We also discover a parameter regime
where the rectification changes sign as a function of temperature.


title:
NeXSPheRIO results on azimuthal anisotropy in Au-Au collisions at 200A
  GeV

abstract:
  In this work, we present the results obtained by the hydrodynamic code
NeXSPheRIO on anisotropic flows. In our calculation, we made use of
event-by-event fluctuating initial conditions, and chemical freeze-out was
explicitly implemented. We studied directed flow, elliptic flow and forth
harmonic coefficient for various hadrons at different centrality windows for
Au+Au collisions at 200 AGeV. The results are discussed and compared with
experimental data from RHIC.


title:
Reduced leakage current in Josephson tunnel junctions with codeposited
  barriers

abstract:
  Josephson junctions were fabricated using two different methods of barrier
formation. The trilayers employed were Nb/Al-AlOx/Nb on sapphire, where the
first two layers were epitaxial. The oxide barrier was formed either by
exposing the Al surface to O2 or by codepositing Al in an O2 background. The
codeposition process yielded junctions that showed the theoretically predicted
subgap current and no measurable shunt conductance. In contrast, devices with
barriers formed by thermal oxidation showed a small shunt conductance in
addition to the predicted subgap current.


title: Exponential decay for solutions to semilinear damped wave equation

abstract:
  This paper is concerned with decay estimate of solutions to the semilinear
wave equation with strong damping in a bounded domain. Introducing an
appropriate Lyaponuv function, we prove that when the damping is linear, we can
find initial data, for which the solution decays exponentially. This result
improves an early one in an article of Gazzola and Squassina.


title:
Chiral symmetry breaking and the Banks--Casher relation in lattice QCD
  with Wilson quarks

abstract:
  The Banks--Casher relation links the spontaneous breaking of chiral symmetry
in QCD to the presence of a non-zero density of quark modes at the low end of
the spectrum of the Dirac operator. Spectral observables like the number of
modes in a given energy interval are renormalizable and can therefore be
computed using the Wilson formulation of lattice QCD even though the latter
violates chiral symmetry at energies on the order of the inverse lattice
spacing. Using numerical simulations, we find (in two-flavour QCD) that the low
quark modes do condense in the expected way. In particular, the chiral
condensate can be accurately calculated simply by counting the low modes on
large lattices. Other spectral observables can be considered as well and have a
potentially wide range of uses.


title: First tests of a 800 kJ HTS SMES

abstract:
  SMES using high critical temperature superconductors are interesting for high
power pulsed sources. Operation at temperatures above 20 K makes cryogenics
easier, enhances stability and improves operation as pulsed power source. In
the context of a DGA (Delegation Generate pour l'Armement) project, we have
designed and constructed a 800 kJ SMES. The coil is wound with Nexans
conductors made of Bi-2212 PIT tapes soldered in parallel. The coil consists in
26 superposed simple pancakes wound and bonded on sliced copper plates coated
with epoxy. The rated current is 315 A for an energy of 814 kJ. The external
diameter of the coil is 814 mm and its height 222 mm. The cooling at 20 K is
only performed by conduction from cryocoolers to make cryogenics very friendly
and invisible for the SMES users. The cooling down has been successfully
carried out and the thermal system works as designed. After a brief description
of the SMES design and construction, some tests will be presented. From a
current of 244 A, the SMES delivered 425 kJ to a resistance with a maximum
power of 175 kW.


title: Real spin glasses relax slowly in the shade of hierarchical trees

abstract:
  The Parisi solution of the mean-field spin glass has been widely accepted and
celebrated. Its marginal stability in 3d and its complexity however raised the
question of its relevance to real spin glasses. This paper gives a short
overview of the important experimental results which could be understood within
the mean-field solution. The existence of a true phase transition and the
particular behaviour of the susceptibility below the freezing temperature,
predicted by the theory, are clearly confirmed by the experimental results. The
behaviour of the complex order parameter and of the Fluctuation Dissipation
ratio are in good agreement with results of spontaneous noise measurements. The
very particular ultrametric symmetry, the key feature of the theory, provided
us with a simple description of the rejuvenation and memory effects observed in
experiment. Finally, going a step beyond mean-field, the paper shortly
discusses new analyses in terms of correlated domains characterized by their
length scales, as well as new experiments on superspin glasses which compare
well with recent theoretical simulations.


title:
Planet influence on the shape of the hosting star - ellipsoidal
  variations of tau Bootis

abstract:
  This paper presents estimations on the possibility of detection of
ellipsoidal variations by means of measuring brightness of the star distorted
by a close massive planet using Wilson-Devinney method. The problem was already
discussed by Phafl et al. (2008) and earlier by Loeb and Gaudi (2003). The
effect is well known in the case of binary stars where it can produce light
curves with amplitutudes of ellipsoidal variations of about 0.1 mag for
distorted stars. For planets the effect is very small and usually less than
0.0001 mag. The detection of an exoplanet, by searching for small amplitude
ellipsoidal variations, will be very difficult and affected by other
photometric effects; however, it maybe possible for some extreme cases.
Observations of ellipsoidal variations can provide additional constraints on
the model of the system. Light curves for few star/planet systems have been
calculated using PHOEBE eclipsing binary software based on Wilson-Devinney
method. As an example of ellipsoidal variations the synthetic light curve for
tau Bootis is presented. The amplitude of ellipsoidal variation is 0.01 mmag.
The companion is massive 7.3 Mjup and short-period hot Jupiter.


title: MIMO Two-way Relay Channel: Diversity-Multiplexing Tradeoff Analysis

abstract:
  A multi-hop two-way relay channel is considered in which all the terminals
are equipped with multiple antennas. Assuming independent quasi-static Rayleigh
fading channels and channel state information available at the receivers, we
characterize the optimal diversity-multiplexing gain tradeoff (DMT) curve for a
full-duplex relay terminal. It is shown that the optimal DMT can be achieved by
a compress-and-forward type relaying strategy in which the relay quantizes its
received signal and transmits the corresponding channel codeword. It is
noteworthy that, with this transmission protocol, the two transmissions in
opposite directions can achieve their respective single user optimal DMT
performances simultaneously, despite the interference they cause to each other.
Motivated by the optimality of this scheme in the case of the two-way relay
channel, a novel dynamic compress-and-forward (DCF) protocol is proposed for
the one-way multi-hop MIMO relay channel for a half-duplex relay terminal, and
this scheme is shown to achieve the optimal DMT performance.


title:
Large Amplitude Dynamics of the Pairing Correlations in a Unitary Fermi
  Gas

abstract:
  A unitary Fermi gas has a surprisingly rich spectrum of large amplitude modes
of the pairing field alone, which defies a description within a formalism
involving only a reduced set of degrees of freedom, such as quantum
hydrodynamics or a Landau-Ginzburg-like description. These modes are very slow,
with oscillation frequencies well below the pairing gap, which makes their
damping through quasiparticle excitations quite ineffective. In atomic traps
these modes couple naturally with the density oscillations, and the
corresponding oscillations of the atomic cloud are an example of a new type of
collective mode in superfluid Fermi systems. They have lower frequencies than
the compressional collective hydrodynamic oscillations, have a non-spherical
momentum distribution, and could be excited by a quick time variation of the
scattering length.


title: Reduction and Realization in Toda and Volterra

abstract:
  We construct a new symplectic, bi-hamiltonian realization of the KM-system by
reducing the corresponding one for the Toda lattice. The bi-hamiltonian pair is
constructed using a reduction theorem of Fernandes and Vanhaecke. In this paper
we also review the important work of Moser on the Toda and KM-systems.


title:
Microwave response of vortices in superconducting thin films of Re and
  Al

abstract:
  Vortices in superconductors driven at microwave frequencies exhibit a
response related to the interplay between the vortex viscosity, pinning
strength, and flux creep effects. At the same time, the trapping of vortices in
superconducting microwave resonant circuits contributes excess loss and can
result in substantial reductions in the quality factor. Thus, understanding the
microwave vortex response in superconducting thin films is important for the
design of such circuits, including superconducting qubits and photon detectors,
which are typically operated in small, but non-zero, magnetic fields. By
cooling in fields of the order of 100 $\mu$T and below, we have characterized
the magnetic field and frequency dependence of the microwave response of a
small density of vortices in resonators fabricated from thin films of Re and
Al, which are common materials used in superconducting microwave circuits.
Above a certain threshold cooling field, which is different for the Re and Al
films, vortices become trapped in the resonators. Vortices in the Al resonators
contribute greater loss and are influenced more strongly by flux creep effects
than in the Re resonators. This different behavior can be described in the
framework of a general vortex dynamics model.


title: Neutrino electromagnetic properties

abstract:
  The main goal of the paper is to give a short review on neutrino
electromagnetic properties. In the introductory part of the paper a summary on
what we really know about neutrinos is given: we discuss the basics of neutrino
mass and mixing as well as the phenomenology of neutrino oscillations. This is
important for the following discussion on neutrino electromagnetic properties
that starts with a derivation of the neutrino electromagnetic vertex function
in the most general form, that follows from the requirement of Lorentz
invariance, for both the Dirac and Majorana cases. Then, the problem of the
neutrino form factors definition and calculation within gauge models is
considered. In particular, we discuss the neutrino electric charge form factor
and charge radius, dipole magnetic and electric and anapole form factors.
Available experimental constraints on neutrino electromagnetic properties are
also discussed, and the recently obtained experimental limits on neutrino
magnetic moments are reviewed. The most important neutrino electromagnetic
processes involving a direct neutrino coupling with photons (such as neutrino
radiative decay, neutrino Cherenkov radiation, spin light of neutrino and
plasmon decay into neutrino-antineutrino pair in media) and neutrino resonant
spin-flavor precession in a magnetic field are discussed at the end of the
paper.