title: The Div-Curl Lemma Revisited

abstract:
  The Div-Curl Lemma, which is the basic result of the compensated compactness
theory in Sobolev spaces, was introduced by F. Murat (1978) with distinct
proofs for the $L^2(\Omega)$ and $L^p(\Omega)$, $p \neq 2$, cases. In this note
we present a slightly different proof, relying only on a Green-Gauss integral
formula and on the usual Rellich-Kondrachov compactness properties.


title:
Probing the nature of IGR J16493-4348: Spectral and temporal analysis of
  the 1-100 keV emission

abstract:
  IGR J16493-4348 was one of the first new sources to be detected by the
INTEGRAL gamma-ray telescope in the 18-100 keV energy band. Based upon spatial
coincidence the source was originally associated with the free radio pulsar PSR
J1649-4349. Presented here are the results of 2.8 Ms of observations made by
the INTEGRAL mission and a 5.6 ks observation with the Swift X-ray Telescope.
Spectral analysis indicates that the source is best modeled by an absorbed
power law with a high energy cut-off at E$_{cut}$~15 keV and a hydrogen
absorbing column of NH=5.4$^{+1.3}_{-1}$ x 10$^{22}$ cm$^{-2}$. Analysis of the
light curves indicates that the source is a weak, persistent gamma-ray emitter
showing indications of variability in the 2-9 and 22-100 keV bands. The average
source flux is ~1.1 x 10^{-10} erg cm$^{-2}$ s$^{-1}$ in the 1-100 keV energy
band. No coherent timing signal is identified at any timescale in the INTEGRAL
or Swift data.
  The refined source location and positional uncertainty of IGR J16493-4348
places PSR J1649-4349 outside of the 90% error circle. We conclude that IGR
J16493-4348 is not associated with PSR J1649-4349. Combining the INTEGRAL
observations with Swift/XRT data and information gathered by RXTE and Chandra
we suggest that IGR J16493-4348 is an X-ray binary; and that the source
characteristics favour a high mass X-ray binary although an LMXB nature cannot
be ruled out.


title: Central engine afterglow of Gamma-ray Bursts

abstract:
  Before 2004, nearly all GRB afterglow data could be understood in the context
of the external shocks model. This situation has changed in the past two years,
when it became clear that some afterglow components should be attributed to the
activity of the central engine; i.e., the {\it central engine afterglow}. We
review here the afterglow emission that is directly related to the GRB central
engine. Such an interpretation proposed by Katz, Piran & Sari, peculiar in
pre-{\it Swift} era, has become generally accepted now.


title:
Quantum homogenization and state randomization in semi-quantal spin
  systems

abstract:
  We investigate dynamics of semi-quantal spin systems in which quantum bits
are attached to classically and possibly stochastically moving classical
particles. The interaction between the quantum bits takes place when the
respective classical particles get close to each other in space. We find that
with Heisenberg XX couplings quantum homogenization takes place after a time
long enough, regardless of the details of the underlying classical dynamics.
This is accompanied by the development of a stationary bipartite entanglement.
If the information on the details of the motion of a stochastic classical
system is disregarded, the stationary state of the whole quantum subsystem is
found to be a complete mixture in the studied cases, though the transients
depend on the properties of the classical motion.


title: Band profiles and band strengths in mixed H2O:CO ices

abstract:
  A laboratory study on the band profiles and band strengths of H2O in CO ice,
and vice versa, is presented and interpreted in terms of two models. The
results show that a mutual interaction takes place between the two species in
the solid, which alters the band positions and band strengths. It is found that
the band strengths of the H2O bulk stretch, bending and libration vibrational
bands decrease linearly by a factor of up to 2 when the CO concentration is
increased from 0 to 80%. By contrast, the band strength of the free OH stretch
increases linearly. The results are compared to a recently performed
quantitative study on H2O:CO2 ice mixtures. It is shown that for mixing ratios
of 1:0.5 H2O:X and higher, the H2O bending mode offers a good tracer to
distinguish between CO2 or CO in H2O ice. Additionally, it is found that the
band strength of the CO fundamental remains constant when the water
concentration is increased in the ice. The integrated absorbance of the 2152
cm-1 CO feature, with respect to the total integrated CO absorption feature, is
found to be a good indicator of the degree of mixing of CO in the H2O:CO
laboratory ice system. From the change in the H2O absorption band strength in
laboratory ices upon mixing we conclude that astronomical water ice column
densities on various lines of sight can be underestimated by up to 25% if
significant amounts of CO and CO2 are mixed in.


title: Electromagnon excitations in modulated multiferroics

abstract:
  The phenomenological theory of ferroelectricity in spiral magnets presented
in [M. Mostovoy, Phys. Rev. Lett. 96, 067601 (2006)] is generalized to describe
consistently states with both uniform and modulated-in-space ferroelectric
polarizations. A key point in this description is the symmetric part of the
magnetoelectric coupling since, although being irrelevant for the uniform
component, it plays an essential role for the non-uniform part of the
polarization. We illustrate this importance in generic examples of modulated
magnetic systems: longitudinal and transverse spin-density wave states and
planar cycloidal phase. We show that even in the cases with no uniform
ferroelectricity induced, polarization correlation functions follow to the soft
magnetic behavior of the system due to the magnetoelectric effect. Our results
can be easily generalized for more complicated types of magnetic ordering, and
the applications may concern various natural and artificial systems in
condensed matter physics (e.g., magnon properties could be extracted from
dynamic dielectric response measurements).


title:
Pr\'ediction de l'\'evolution granulom\'etrique et morphologique d'une
  poudre dans un four tournant

abstract:
  The dry conversion process for making UO2 nuclear fuel pellets consists of
two steps: hydrolysis of UF6 to UO2F2, followed by reducing pyrohydrolysis to
UO2 in a rotary kiln. The physical characteristics (morphology, particle size
distribution) of the powder obtained at the kiln end determine the final
properties (sinterability, flow-ability, green strength). We developed a
mathematical model describing the morphological evolution of the powder in the
rotary kiln, which enables us to predict morphological characteristics of UO2
powder as functions of the processing conditions. Firstly, the powder flow in
the kiln was modelled, including the exchanges between a dense phase (powder
bed) and an airborne phase (particles showering down). An original feature of
this model is to consider the effect of lifters for calculating the dynamic
variables. Secondly, the phenomena responsible for the changes in morphology
and grain size were identified and modelled. A population of fractal
agglomerates was considered, whose number and size change due to Brownian and
sedimentation agglomeration, sintering, breaking up, and chemical reactions.
The model is based on population balances and the particle size distribution is
divided into sections. Results of both dynamic and morphological calculations
are compared to available measurements. Lastly, the influence of the different
mechanisms of morphological evolution on the final size distribution is
analysed.


title: How to remove the boundary in CFT - an operator algebraic procedure

abstract:
  The relation between two-dimensional conformal quantum field theories with
and without a timelike boundary is explored.


title:
Numerical Sensitivity and Efficiency in the Treatment of Epistemic and
  Aleatory Uncertainty

abstract:
  The treatment of both aleatory and epistemic uncertainty by recent methods
often requires an high computational effort. In this abstract, we propose a
numerical sampling method allowing to lighten the computational burden of
treating the information by means of so-called fuzzy random variables.


title: Thermodynamics of Apparent Horizon in Brane World Scenarios

abstract:
  Applying the Clausius relation, $\delta Q=TdS$, to the apparent horizon of
FRW universe in brane world scenarios, we show that an explicit entropy
expression associated with the apparent horizon can be obtained. On the
apparent horizon, the relation, $dE=TdS +WdV$, also holds in the brane world
scenarios. We show these results in the RSII model, warped DGP model and the
more general case with a Gauss-Bonnet term in the bulk and an intrinsic
curvature term on the brane.


title: Complexes of Injective Words and Their Commutation Classes

abstract:
  Let $S$ be a finite alphabet. An injective word over $S$ is a word over $S$
such that each letter in $S$ appears at most once in the word. We study Boolean
cell complexes of injective words over $S$ and their commutation classes. This
generalizes work by Farmer and by Bj\"orner and Wachs on the complex of all
injective words.


title: Cylindrical spacetimes with a cosmological constant and their sources

abstract:
  We review and investigate some basic properties of static, cylindrically
symmetric spacetimes with non-zero cosmological constant, find non-singular
sheet sources of these spacetimes and discuss their characteristics, and
clarify their relation to the 4D black-string solutions.


title: Atomic four-wave mixing via condensate collisions

abstract:
  We perform a theoretical analysis of atomic four-wave mixing via a collision
of two Bose-Einstein condensates of metastable helium atoms, and compare the
results to a recent experiment. We calculate atom-atom pair correlations within
the scattering halo produced spontaneously during the collision. We also
examine the expected relative number squeezing of atoms on the sphere. The
analysis includes first-principles quantum simulations using the positive
P-representation method. We develop a unified description of the experimental
and simulation results.


title: An example of noncommutative deformations

abstract:
  We compute the noncommutative deformations of a family of modules over the
first Weyl algebra. This example shows some important properties of
noncommutative deformation theory that separates it from commutative
deformation theory.


title: Sobolev homeomorphisms and Poincare inequality

abstract:
  We study global regularity properties of Sobolev homeomorphisms on
$n$-dimensional Riemannian manifolds under the assumption of $p$-integrability
of its first weak derivatives in degree $p\geq n-1$. We prove that inverse
homeomorphisms have integrable first weak derivatives. For the case $p>n$ we
obtain necessary conditions for existence of Sobolev homeomorphisms between
manifolds. These necessary conditions based on Poincar\'e type inequality: $$
\inf_{c\in \mathbb R} \|u-c\mid L_{\infty}(M)\|\leq K \|u\mid
L^1_{\infty}(M)\|. $$ As a corollary we obtain the following geometrical
necessary condition:
  {\em If there exists a Sobolev homeomorphisms $\phi: M \to M'$, $\phi\in
W^1_p(M, M')$, $p>n$, $J(x,\phi)\ne 0$ a. e. in $M$, of compact smooth
Riemannian manifold $M$ onto Riemannian manifold $M'$ then the manifold $M'$
has finite geodesic diameter.}}


title: Nonequilibrium Dephasing in an Electronic Mach-Zehnder Interferometer

abstract:
  We study nonequilibrium dephasing in an electronic Mach-Zehnder
interferometer. We demonstrate that the shot noise at the beam splitter of the
interferometer generates an ensemble of nonequilibrium electron density
configurations and that electron interactions induce configuration-specific
phase shifts of an interfering electron. The resulting dephasing exhibits two
characteristic features, a lobe pattern in the visibility and phase jumps of
$\pi$, in good agreement with experimental data.


title: GEANT4 and CREME96 comparison using only proton fluxes

abstract:
  CREME96 and GEANT4 are two well known particle transport codes through matter
in space science. We present a comparison between the proton fluxes outgoing
from an aluminium target, obtained by using both tools. The primary proton flux
is obtained by CREME96 only, covering an energy range from MeV to hundreds GeV
with the same result in both cases. We studied different thickness targets and
two different GEANT4 physics lists in order to show how the spectra of the
outgoing proton fluxes are modified. Our findings show consistent agreement of
simulation data by each tool, with regards both GEANT4 physics lists and every
thickness target analysed.


title:
Chemical and forensic analysis of JFK assassination bullet lots: Is a
  second shooter possible?

abstract:
  The assassination of President John Fitzgerald Kennedy (JFK) traumatized the
nation. In this paper we show that evidence used to rule out a second assassin
is fundamentally flawed. This paper discusses new compositional analyses of
bullets reportedly to have been derived from the same batch as those used in
the assassination. The new analyses show that the bullet fragments involved in
the assassination are not nearly as rare as previously reported. In particular,
the new test results are compared to key bullet composition testimony presented
before the House Select Committee on Assassinations (HSCA). Matches of bullets
within the same box of bullets are shown to be much more likely than indicated
in the House Select Committee on Assassinations' testimony. Additionally, we
show that one of the ten test bullets is considered a match to one or more
assassination fragments. This finding means that the bullet fragments from the
assassination that match could have come from three or more separate bullets.
Finally, this paper presents a case for reanalyzing the assassination bullet
fragments and conducting the necessary supporting scientific studies. These
analyses will shed light on whether the five bullet fragments constitute three
or more separate bullets. If the assassination fragments are derived from three
or more separate bullets, then a second assassin is likely, as the additional
bullet would not easily be attributable to the main suspect, Mr. Oswald, under
widely accepted shooting scenarios [see Posner (1993), Case Closed, Bantam, New
York].


title:
Magnetic susceptibility of QCD vacuum at finite density from the
  nonlocal chiral quark model

abstract:
  We present in this talk a recent investigation on the magnetic susceptibility
(chi) of the QCD vacuum at finite density, utilizing the nonlocal chiral quark
model from the instanton vacuum. We take into account the nonzero current-quark
mass (m_q) explicitly to consider the effect of explicit flavor SU(3) symmetry
breaking. It turns out that, when we turn on the current-quark mass, chi
becomes smaller, indicating less response to the externally induced
electromagnetic field, in comparison to that for m_q=0.


title: Analysis of vibration impact on stability of dewetting thin liquid film

abstract:
  Dynamics of a thin dewetting liquid film on a vertically oscillating
substrate is considered. We assume moderate vibration frequency and large
(compared to the mean film thickness) vibration amplitude. Using the
lubrication approximation and the averaging method, we formulate the coupled
sets of equations governing the pulsatile and the averaged fluid flows in the
film, and then derive the nonlinear amplitude equation for the averaged film
thickness. We show that there exists a window in the frequency-amplitude domain
where the parametric and shear-flow instabilities of the pulsatile flow do not
emerge. As a consequence, in this window the averaged description is reasonable
and the amplitude equation holds. The linear and nonlinear analyses of the
amplitude equation and the numerical computations show that such vibration
stabilizes the film against dewetting and rupture.


title: Small index subgroups of the mapping class group

abstract:
  We prove that the mapping class group of a closed oriented surface of genus
$\rho \ge 3$ has no proper subgroup of index $\le 4 \rho +4$.


title: Doppler effect in Schwarzschild geometry

abstract:
  The Doppler shift considered in general relativity involves mixed
contributions of distinct, gravitational and kinematical origins and for most
metrics or trajectories it takes a complex form. The expression for the Doppler
shift may simplify due to particular symmetries. In Schwarzschild spacetime it
factorizes in the case of radial fall for an observer and radial null geodesic.
The resulting expression is composed of factors that can be identified with
contributions arising from classical, special relativistic and general
relativistic origins. This result turns out to be more general: it holds for
the whole class of observers travelling parallel to the spatial path of null
geodesics when receiving the signal. It also holds for a particular type of
in-fall in the case of a Kerr metric.


title: Instability of the Time Dependent Horava-Witten Model

abstract:
  We consider scalar perturbations in the time-dependent Ho\u{r}ava-Witten
Model in order to probe its stability. We show that during the non-singular
epoque the model evolves without instabilities until it encounters the
curvature singularity where a big crunch is supposed to occur. We compute the
frequencies of the scalar field oscillation during the stable period and show
how the oscillations can be used to prove the presence of such a singularity.


title: Probing bilinear R-parity violating supergravity at the LHC

abstract:
  We study the collider phenomenology of bilinear R-parity violating
supergravity, the simplest effective model for supersymmetric neutrino masses
accounting for the current neutrino oscillation data. At the CERN Large Hadron
Collider the center-of-mass energy will be high enough to probe directly these
models through the search for the superpartners of the Standard Model (SM)
particles. We analyze the impact of R-parity violation on the canonical
supersymmetry searches - that is, we examine how the decay of the lightest
supersymmetric particle (LSP) via bilinear R-parity violating interactions
degrades the average expected missing momentum of the reactions and show how
this diminishes the reach in the 'usual' channels for supersymmetry searches.
However, the R-parity violating interactions lead to an enhancement of the
final states containing isolated same-sign di-leptons and trileptons,
compensating the reach loss in the fully inclusive channel. We show how the
searches for displaced vertices associated to LSP decay substantially increase
the coverage in supergravity parameter space, giving the corresponding reaches
for two reference luminosities of 10 and 100 fb$^{-1}$ and compare with those
of the R-parity conserving minimal supergravity model.


title: Vehicular traffic flow at a non-signalised intersection

abstract:
  We have developed a modified Nagel-Schreckenberg cellular automata model for
describing a conflicting vehicular traffic flow at the intersection of two
streets. No traffic lights control the traffic flow. The approaching cars to
the intersection yield to each other to avoid collision. Closed boundary
condition is applied to the streets. Extensive Monte Carlo simulations is taken
into account to find the model characteristics. In particular, we obtain the
fundamental diagrams and show that the effect of interaction of two streets can
be regarded as a dynamic impurity located at the intersection point. Our
results suggest that yielding mechanism gives rise to a high total flow
throughout the intersection especially in the low density regime. In some
ranges of densities, yielding mechanism even improves and regulates the flow in
comparison to the absence of perpendicular flow.


title: Extended su(2)_k and restricted U_q sl(2)

abstract:
  Global gauge symmetry becomes more intricate in low dimensional QFT. We
survey the mathematical concepts leading to the relevant analogues of the (D=4)
Doplicher-Haag-Roberts theory of superselection sectors and internal symmetry.
We also review a recently uncovered duality between braid and quantum group
representations in an extension of the chiral su(2)_k WZNW model for
nonnegative integer level k.


title: Stellar contents and star formation in the young open cluster Stock 8

abstract:
  We present $UBVI_c$ CCD photometry of the young open cluster Stock 8 with the
aim to study the basic properties and star formation scenario in this region.
The radius of the cluster is found to be $\sim 6^{\prime}$ ($\sim 3.6$ pc) and
the reddening within the cluster region varies from $E(B-V)=0.40$ to 0.60 mag.
The cluster is located at a distance of $2.05 \pm 0.10$ kpc. Using H$\alpha$
slitless spectroscopy and 2MASS NIR data we identified H$\alpha$ emission and
NIR excess young stellar objects (YSOs), respectively. The colour-magnitude
diagrams of these YSOs reveal that majority of these objects have ages between
1 to 5 Myr indicating a non-coeval star formation in the cluster. Massive stars
in the cluster region reveal an average age of $\le$ 2 Myr. In the cluster
region ($r \le 6^\prime$) the slope of the mass function (MF), $\Gamma$, in the
mass range $\sim 1.0 \le M/M_\odot < 13.4$ can be represented by a power law
having a slope of $-1.38\pm0.12$, which agrees well with Salpeter value
(-1.35). In the mass range $0.3 \le M/M_\odot < 1.0$, the MF is also found to
follow a power law with a shallower slope of $\Gamma = -0.58\pm 0.23$
indicating a break in the slope of the IMF at $\sim 1 M_\odot$. The slope of
the $K$-band luminosity function for the cluster ($r \le 6^\prime$) is found to
be $0.31\pm0.02$, which is smaller than the average value ($\sim$ 0.4) obtained
for embedded star clusters. A significant number of YSOs are distributed along
a Nebulous Stream towards the east side of the cluster. A small cluster is
embedded in the Nebulous Stream. The YSOs lying in the Nebulous Stream and in
the embedded cluster are found to be younger than the stars in the cluster
Stock 8. It appears that star formation activity in the Nebulous Stream and
embedded cluster may be independent from that of Stock 8.


title: Statistics of geodesics in large quadrangulations

abstract:
  We study the statistical properties of geodesics, i.e. paths of minimal
length, in large random planar quadrangulations. We extend Schaeffer's
well-labeled tree bijection to the case of quadrangulations with a marked
geodesic, leading to the notion of "spine trees", amenable to a direct
enumeration. We obtain the generating functions for quadrangulations with a
marked geodesic of fixed length, as well as with a set of "confluent
geodesics", i.e. a collection of non-intersecting minimal paths connecting two
given points. In the limit of quadrangulations with a large area n, we find in
particular an average number 3*2^i of geodesics between two fixed points at
distance i>>1 from each other. We show that, for generic endpoints, two
confluent geodesics remain close to each other and have an extensive number of
contacts. This property fails for a few "exceptional" endpoints which can be
linked by truly distinct geodesics. Results are presented both in the case of
finite length i and in the scaling limit i ~ n^(1/4). In particular, we give
the scaling distribution of the exceptional points.


title:
Non-existence of polar factorisations and polar inclusion of a
  vector-valued mapping

abstract:
  This paper proves some results concerning the polar factorisation of an
integrable vector-valued function u into the composition of the gradient of a
convex function with a measure-preserving mapping. Not every integrable
function has a polar factorisation; we extend the class of counterexamples. We
introduce a generalisation: u has a polar inclusion if u(x) belongs to the
subdifferential of the convex function at y for almost every pair (x,y) with
respect to a measure-preserving plan. Given a regularity assumption, we show
that such measure-preserving plans are exactly the minimisers of a
Monge-Kantorovich optimisation problem.


title: Relativistic models of magnetars: structure and deformations

abstract:
  We find numerical solutions of the coupled system of Einstein-Maxwell's
equations with a linear approach, in which the magnetic field acts as a
perturbation of a spherical neutron star. In our study, magnetic fields having
both poloidal and toroidal components are considered, and higher order
multipoles are also included. We evaluate the deformations induced by different
field configurations, paying special attention to those for which the star has
a prolate shape. We also explore the dependence of the stellar deformation on
the particular choice of the equation of state and on the mass of the star. Our
results show that, for neutron stars with mass M = 1.4 Msun and surface
magnetic fields of the order of 10^15 G, a quadrupole ellipticity of the order
of 10^(-6) - 10^(-5) should be expected. Low mass neutron stars are in
principle subject to larger deformations (quadrupole ellipticities up to
10^(-3) in the most extreme case). The effect of quadrupolar magnetic fields is
comparable to that of dipolar components. A magnetic field permeating the whole
star is normally needed to obtain negative quadrupole ellipticities, while
fields confined to the crust typically produce positive quadrupole
ellipticities.


title:
Generalized Tsirelson Inequalities, Commuting-Operator Provers, and
  Multi-Prover Interactive Proof Systems

abstract:
  A central question in quantum information theory and computational complexity
is how powerful nonlocal strategies are in cooperative games with imperfect
information, such as multi-prover interactive proof systems. This paper
develops a new method for proving limits of nonlocal strategies that make use
of prior entanglement among players (or, provers, in the terminology of
multi-prover interactive proofs). Instead of proving the limits for usual
isolated provers who initially share entanglement, this paper proves the limits
for "commuting-operator provers", who share private space, but can apply only
such operators that are commutative with any operator applied by other provers.
Commuting-operator provers are at least as powerful as usual isolated but
prior-entangled provers, and thus, limits for commuting-operator provers
immediately give limits for usual entangled provers. Using this method, we
obtain an n-party generalization of the Tsirelson bound for the Clauser-Horne-
Shimony-Holt inequality for every n. Our bounds are tight in the sense that, in
every n-party case, the equality is achievable by a usual nonlocal strategy
with prior entanglement. We also apply our method to a 3-prover 1-round binary
interactive proof for NEXP. Combined with the technique developed by Kempe,
Kobayashi, Matsumoto, Toner and Vidick to analyze the soundness of the proof
system, it is proved to be NP-hard to distinguish whether the entangled value
of a 3-prover 1-round binary-answer game is equal to 1 or at most 1-1/p(n) for
some polynomial p, where n is the number of questions. This is in contrast to
the 2-prover 1-round binary-answer case, where the corresponding problem is
efficiently decidable. Alternatively, NEXP has a 3-prover 1-round binary
interactive proof system with perfect completeness and soundness 1-2^{-poly}.


title: Bjorken flow from an AdS Schwarzschild black hole

abstract:
  We consider a large black hole in asymptotically AdS spacetime of arbitrary
dimension with a Minkowski boundary. By performing an appropriate slicing as we
approach the boundary, we obtain via holographic renormalization a gauge theory
fluid obeying Bjorken hydrodynamics in the limit of large longitudinal proper
time. The metric we obtain reproduces to leading order the metric recently
found as a direct solution of the Einstein equations in five dimensions. Our
results are also in agreement with recent exact results in three dimensions.


title:
Isomorphism of critical and off-critical operator spaces in
  two-dimensional quantum field theory

abstract:
  For the simplest quantum field theory originating from a non-trivial fixed
point of the renormalization group, the Lee-Yang model, we show that the
operator space determined by the particle dynamics in the massive phase and
that prescribed by conformal symmetry at criticality coincide.

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


title:
Detection of fast neutrons and digital pulse-shape discrimination
  between neutrons and gamma rays

abstract:
  The basic principles of detection of fast neutrons with liquid scintillator
detectors are reviewed, together with a real example in the form of the Neutron
Wall array. Two of the challenges in neutron detection, discrimination of
neutrons and gamma rays and identification of cross talk between detectors due
to neutron scattering, are briefly discussed, as well as possible solutions to
these problems. The possibilities of using digital techniques for pulse-shape
discrimination are examined. Results from a digital and analog versions of the
zero cross-over algorithm are presented. The digital pulse-shape discrimination
is shown to give, at least, as good results as the corresponding analogue
version.


title: Existence of positive definite noncoercive sums of squares

abstract:
  Positive definite forms $f$ which are sums of squares are constructed to have
the additional property that the members of any collection of forms whose
squares sum to $f$ must share a nontrivial complex root.


title:
Study of conditions of use of E-services accessible to visually disabled
  persons

abstract:
  The aim of this paper is to determine the expectations that French-speaking
disabled persons have for electronic administrative sites (utility). At the
same time, it is a matter of identifying the difficulties of use that the
manipulation of these E-services poses concretely for blind people (usability)
and of evaluating the psychosocial impacts on the way of life of these people
with specific needs. We show that the lack of numerical accessibility is likely
to accentuate the social exclusion of which these people are victim by
establishing a numerical glass ceiling.


title: Radio emission in clusters and connection to X-ray emission

abstract:
  The most spectacular aspect of cluster radio emission is represented by the
large-scale diffuse radio sources, which cannot be obviously associated with
any individual galaxy. These sources demonstrate the existence of relativistic
particles and magnetic fields in the cluster volume, thus indicating the
presence of non-thermal processes in the hot intracluster medium. The knowledge
of the properties of these sources has increased significantly in recent years,
owing to sensitive radio images and to the development of theoretical models.
An important piece of information on the origin and evolution of these sources
can be obtained by the cluster X-ray emission of thermal origin, and by its
relation to the radio emission. Moreover, non-thermal X-ray emission of inverse
Compton origin gives direct information on the energy density of radio emitting
particles and the intensity of magnetic field.


title: Lorentz-violation-induced arrival delays of cosmological particles

abstract:
  We point out that previous studies of possible Lorentz-violating effects in
astronomical time-of-flight data did not take into account the entire
implications of the universe's cosmological expansion. We present the
derivation of the accurate formulation of the problem and show that the
resulting correction of the limits on Lorentz violation is significant.


title:
Scattering of massive W bosons into gravitinos and tree unitarity in
  broken supergravity

abstract:
  The WW scattering into gravitino and gaugino is here investigated in the
broken phase, by using both gauge and mass eigenstates. Differently from what
is obtained for unbroken gauge symmetry, we find in the scattering amplitudes
new structures, which can lead to violation of unitarity above a certain scale.
This happens because, in the annihilation diagram, the longitudinal degrees of
freedom in the propagator of the gauge bosons disappear from the amplitude, by
virtue of the SUGRA vertex. We show that the longitudinal polarizations of the
on-shell W become strongly interacting in the high energy limit, and that the
inclusion of diagrams with off-shell scalars of the MSSM does not cancel the
divergences.


title: Integration on valuation fields over local fields

abstract:
  We present elements of a theory of translation-invariant integration,
measure, and harmonic analysis on a valuation field with local field as residue
field. This extends the work of Fesenko. Applications to zeta integrals for
two-dimensional local fields are then considered.


title: Calabi-Yau crystals in topological string theory

abstract:
  This thesis is concerned with a realisation of topological theories in terms
of statistical models known as Calabi-Yau crystals. The thesis starts with an
introduction and review of topological field and string theories. Subsequently
several new results are presented. The main focus of the thesis is on the
topological string theory. In this case crystal models correspond to
three-dimensional partitions and their relations with the topological vertex
theory and knot invariants are studied. Two-dimensional crystal models
corresponding to topological gauge theories on ALE spaces are also introduced
and analysed. Essential mathematical tools are summarised in appendices.


title: Anyons and lowest Landau level Anyons

abstract:
  A review on the Anyon model and the lowest Landau level Anyon model is
presented.


title:
Integration on product spaces and GL_n of a valuation field over a local
  field

abstract:
  We present elements of a theory of translation-invariant integration on
finite dimensional vector spaces and on GL_n over a valuation field with local
field as residue field. We then discuss the case of an arbitrary algebraic
group. This extends the work of Fesenko.


title: Multi-angle effects in collective supernova neutrino oscillations

abstract:
  We study two-flavor collective neutrino oscillations in the dense-neutrino
region above the neutrino sphere in a supernova (SN). The angular dependence of
the neutrino-neutrino interaction potential causes "multi-angle" effects that
can lead either to complete kinematical decoherence in flavor space or only to
small differences between different trajectories. This nonlinear system
switches abruptly between "self-maintained coherence" and "self-induced
decoherence" among the angular modes, depending on the strength of the
deleptonization flux. For a realistic SN the quasi single-angle behavior is
probably typical, simplifying the numerical treatment and probably allowing for
the survival of observational features of flavor oscillations.


title:
Fubini's theorem and non-linear change of variables over a
  two-dimensional local field

abstract:
  We consider non-linear changes of variables and Fubini's theorem for certain
integrals over a two-dimensional local field. An interesting example is
presented in which imperfectness of a finite characteristic local field causes
Fubini's theorem to unexpectedly fail. The relationship to ramification theory
is discussed.


title: Entropy Fluctuations in Brane Inflation Models

abstract:
  We study the development of entropy fluctuations in brane inflation in a
warped throat, including the brane-antibrane tachyon as the waterfall field. We
find that there is a period at the end of inflation during which the entropy
mode associated with the tachyon field increases exponentially. In turn, the
induced entropy seeds a contribution to the curvature fluctuation on
cosmological scales which grows rapidly and could exceed the primordial
curvature perturbation. We identify parameter values for which in the absence
of back-reaction the induced curvature fluctuations are larger than the
primordial adiabatic ones. In the specific model we study, however,
back-reaction limits the growth of the entropy fluctuations. We discuss
situations in which back-reaction effects are less constraining. The lesson of
our investigation is that the study of the development of entropy fluctuations
at the end of the period of inflation can lead to constraints on models of
brane inflation and suggests that the curvaton mechanism may contribute
significantly to the spectrum of cosmological perturbations.


title:
Study of GEM-like detectors with resistive electrodes for RICH
  applications

abstract:
  We have developed prototypes of GEM-like detectors with resistive electrodes
to be used as RICH photodetectors equipped with CsI photocathodes. The main
advantages of these detectors are their intrinsic spark protection and
possibility to operate at high gain (~10E5) in many gases including poorly
quenched ones, allowing for the adoption of windowless configurations in which
the radiator gas is also used in the chamber. Results of systematic studies of
the resistive GEMs combined with CsI photocathodes are presented: its quantum
efficiency, rate characteristics, long-term stability, etc. On the basis of the
obtained results, we believe that the new detector will be a promising
candidate for upgrading the ALICE RICH detector


title:
In situ x-ray diffraction study of epitaxial growth of ordered Fe3Si
  films

abstract:
  Molecular beam epitaxy of Fe3Si on GaAs(001) is studied in situ by grazing
incidence x-ray diffraction. Layer-by-layer growth of Fe3Si films is observed
at a low growth rate and substrate temperatures near 200 degrees Celsius. A
damping of x-ray intensity oscillations due to a gradual surface roughening
during growth is found. The corresponding sequence of coverages of the
different terrace levels is obtained. The after-deposition surface recovery is
very slow. Annealing at 310 degrees Celsius combined with the deposition of one
monolayer of Fe3Si restores the surface to high perfection and minimal
roughness. Our stoichiometric films possess long-range order and a high quality
heteroepitaxial interface.


title:
Tuning competing orders in La2-xSrxCuO4 cuprate superconductors by the
  application of an external magnetic field

abstract:
  We report the results of a combined muon spin rotation and neutron scattering
study on La2-xSrxCuO4 in the vicinity of the so-called 1/8-anomaly. Application
of a magnetic field drives the system towards a magnetically ordered
spin-density-wave state, which is fully developed at 1/8 doping. The results
are discussed in terms of competition between antiferromagnetic and
superconducting order parameters.


title: Optimal codes for correcting a single (wrap-around) burst of errors

abstract:
  In 2007, Martinian and Trott presented codes for correcting a burst of
erasures with a minimum decoding delay. Their construction employs [n,k] codes
that can correct any burst of erasures (including wrap-around bursts) of length
n-k. The raised the question if such [n,k] codes exist for all integers k and n
with 1<= k <= n and all fields (in particular, for the binary field). In this
note, we answer this question affirmatively by giving two recursive
constructions and a direct one.


title:
Apports des d\'emarches d'inspection et des tests d'usage dans
  l'\'evaluation de l'accessibilit\'e de E-services

abstract:
  This article proposes to describe and compare the contributions of various
techniques of evaluation of the accessibility of E-services carried out
starting from (i) methods of inspection (on the basis of traditional ergonomic
criteria and accessibility) and (ii) of tests of use. It show that these are
the latter which show the best rate of identification of the problems of uses
for the poeple with disabilities


title: The ordered distribution of natural numbers on the square root spiral

abstract:
  Natural numbers divisible by the same prime factor lie on defined spiral
graphs which are running through the Square Root Spiral (also named as the
Spiral of Theodorus or Wurzel Spirale or Einstein Spiral). Prime Numbers also
clearly accumulate on such spiral graphs. And the square numbers 4, 9, 16, 25,
36,... form a highly three-symmetrical system of three spiral graphs, which
divides the square-root-spiral into three equal areas. A mathematical analysis
shows that these spiral graphs are defined by quadratic polynomials. Fibonacci
number sequences also play a part in the structure of the Square Root Spiral.
Fibonacci Numbers divide the Square Root Spiral into areas and angle sectors
with constant proportions. These proportions are linked to the golden mean (or
golden section), which behaves as a self-avoiding-walk-constant in the
lattice-like structure of the square root spiral.


title:
Neumann problems associated to nonhomogeneous differential operators in
  Orlicz--Sobolev spaces

abstract:
  We study a nonlinear Neumann boundary value problem associated to a
nonhomogeneous differential operator. Taking into account the competition
between the nonlinearity and the bifurcation parameter, we establish sufficient
conditions for the existence of nontrivial solutions in a related
Orlicz--Sobolev space.


title:
The Afterglows of Swift-era Gamma-Ray Bursts. I. Comparing pre-Swift and
  Swift era Long/Soft (Type II) GRB Optical Afterglows

abstract:
  We have gathered optical photometry data from the literature on a large
sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to
September 2009, for a total of 76 GRBs, and present an additional three
pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840
additional new photometry data points on a total of 42 GRB afterglows,
including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C,
060418, 080413A and 080810. We analyzed the light curves of all GRBs in the
sample and derived spectral energy distributions for the sample with the best
data quality, allowing us to estimate the host galaxy extinction. We
transformed the afterglow light curves into an extinction-corrected z=1 system
and compared their luminosities with a sample of pre-Swift afterglows. The
results of a former study, which showed that GRB afterglows clustered and
exhibited a bimodal distribution in luminosity space, is weakened by the larger
sample. We found that the luminosity distribution of the two afterglow samples
(Swift-era and pre-Swift) are very similar, and that a subsample for which we
were not able to estimate the extinction, which is fainter than the main
sample, can be explained by assuming a moderate amount of line-of-sight host
extinction. We derived bolometric isotropic energies for all GRBs in our
sample, and found only a tentative correlation between the prompt energy
release and the optical afterglow luminosity at one day after the GRB in the
z=1 system. A comparative study of the optical luminosities of GRB afterglows
with echelle spectra (which show a high number of foreground absorbing systems)
and those without reveals no indication that the former are statistically
significantly more luminous. (abridged)


title:
Investigation of Low-Density Symmetry Energy via Nucleon and Fragment
  Observables

abstract:
  With stochastic transport simulations we study in detail central and
peripheral collisions at Fermi energies and suggest new observables, sensitive
to the symmetry energy below normal density. As such we identify on one hand
the isospin imbalance ratio, i.e. the relative amount of isospin equilibration
in binary, peripheral reactions of nuclei with different isospin, as a function
of the energy loss, which is sensitive to isospin diffusion; on the other hand
the isospin asymmetry of an intermediate mass fragment (IMF) in symmetric
collisions in ternary reactions, or more particularly, the ratio of the IMF to
the residue asymmetry, which is sensitive to isospin migration.


title: Capillarity-like growth of protein folding nuclei

abstract:
  We analyzed folding routes predicted by a variational model in terms of a
generalized formalism of the capillarity scaling theory for 28 two-state
proteins. The scaling exponent ranged from 0.2 to 0.45 with an average of 0.33.
This average value corresponds to packing of rigid objects.That is, on average
the folded core of the nucleus is found to be relatively diffuse. We also
studied the growth of the folding nucleus and interface along the folding route
in terms of the density or packing fraction. The evolution of the folded core
and interface regions can be classified into three patterns of growth depending
on how the growth of the folded core is balanced by changes in density of the
interface. Finally, we quantified the diffuse versus polarized structure of the
critical nucleus through direct calculation of the packing fraction of the
folded core and interface regions. Our results support the general picture of
describing protein folding as the capillarity-like growth of folding nuclei.


title: Towards Control of Steady State Plasma on Tore Supra

abstract:
  The Tore Supra tokamak is the largest superconducting magnetic fusion
facility, has been devoted to long-duration high-performance discharge
research. With a steady-state magnetic field and water cooled plasma facing
components, discharges up to 6 minutes 24 seconds duration with injected /
extracted energy up to 1 GJ have been performed. The Tore Supra real time
measurements and control (RTMC) system has been upgraded to address schemes
dedicated to long pulse operation with simultaneous control of an increasing
number of plasma parameters. This includes plasma equilibrium control with
possible self calibration during the discharge, plasma density control with
possible pellet injection, current profile control to avoid
magneto-hydrodynamic (MHD) instabilities and infrared monitoring of plasma
facing components preventing overheating. Most of these improvements are
relevant to the tokamaks operation in a fully steady state regime.


title: Some Late-time Asymptotics of General Scalar-Tensor Cosmologies

abstract:
  We study the asymptotic behaviour of isotropic and homogeneous universes in
general scalar-tensor gravity theories containing a p=-rho vacuum fluid stress
and other sub-dominant matter stresses. It is shown that in order for there to
be approach to a de Sitter spacetime at large 4-volumes the coupling function,
omega(phi), which defines the scalar-tensor theory, must diverge faster than
|phi_infty-phi|^(-1+epsilon) for all epsilon>0 as phi rightarrow phi_infty <> 0
for large values of the time. Thus, for a given theory, specified by
omega(phi), there must exist some phi_infty in (0,infty) such that omega ->
infty and omega' / omega^(2+epsilon) -> 0 as phi -> 0 phi_infty in order for
cosmological solutions of the theory to approach de Sitter expansion at late
times. We also classify the possible asymptotic time variations of the
gravitation `constant' G(t) at late times in scalar-tensor theories. We show
that (unlike in general relativity) the problem of a profusion of ``Boltzmann
brains'' at late cosmological times can be avoided in scalar-tensor theories,
including Brans-Dicke theory, in which phi -> infty and omega ~ o(\phi^(1/2))
at asymptotically late times.


title: f-oscillators deformation for Moyal algebras

abstract:
  Using general construction of star-product the q-deformed Wigner-Weyl-Moyal
quantization procedure is elaborated. The q-deformed Groenewold kernel
determining the product of quantum observables is given in explicit form for
small nonlinearities corresponding to nonlinear vibrations of classical and
quantum q-oscillators. The deformations of Groenewold kernel related to general
kinds of nonlinear vibrations described by f-oscillators are considered.


title: Age-dependent decay in the landscape

abstract:
  The picture of the "multiverse" arising in diverse cosmological scenarios
involves transitions between metastable vacuum states. It was pointed out by
Krauss and Dent that the transition rates decrease at very late times, leading
to a dependence of the transition probability between vacua on the age of each
vacuum region. I investigate the implications of this non-Markovian,
age-dependent decay on the global structure of the spacetime in landscape
scenarios. I show that the fractal dimension of the eternally inflating domain
is precisely equal to 3, instead of being slightly below 3 in scenarios with
purely Markovian, age-independent decay. I develop a complete description of a
non-Markovian landscape in terms of a nonlocal master equation. Using this
description I demonstrate by an explicit calculation that, under some technical
assumptions about the landscape, the probabilistic predictions of our position
in the landscape are essentially unchanged, regardless of the measure used to
extract these predictions. I briefly discuss the physical plausibility of
realizing non-Markovian vacuum decay in cosmology in view of the possible
decoherence of the metastable quantum state.


title:
Harmonic functions on R-covered foliations and group actions on the
  circle

abstract:
  Let (M, F) be a compact codimension-one foliated manifold whose leaves are
equipped with Riemannian metrics, and consider continuous functions on M that
are harmonic along the leaves of F . If every such function is constant on
leaves we say that (M, F) has the Liouville property. Our main result is that
codimension-one foliated bundles over compact negatively curved manifolds
satisfy the Liouville property. Related results for R-covered foliations, as
well as for discrete group actions and discrete harmonic functions, are also
established.


title: Cohomological analysis of the Epstein-Glaser renormalization

abstract:
  A cohomological analysis of the renormalization freedom is performed in the
Epstein-Glaser scheme on a flat Euclidean space. We study the deviation from
commutativity between the renormalization and the action of all linear partial
differential operators. It defines a Hochschild 1-cocycle and the
renormalization ambiguity corresponds to a nonlinear subset in the cohomology
class of this renormalization cocycle. We have shown that the related
cohomology spaces can be reduced to de Rham cohomologies of the so called
"(ordered) configuration spaces". We have also found cohomological differential
equations that exactly determine the renormalization cocycles up to the
renormalization freedom. This analysis is a first step towards a new approach
for computing renormalization group actions. It can be also naturally extended
to manifolds as well as to the case of causal perturbation theory.


title: Quark and Gluon Degrees of Freedom in High-Energy Heavy Ion Collisions

abstract:
  I discuss some recent progress in our understanding of high energy nuclear
collisions. I will focus on two topics which I was lucky to co-pioneer in the
recent past. One is recombination of quarks and its interpretation as a signal
for deconfinement, the second is electromagnetic radiation from jets passing
through a quark gluon plasma. This talk was given during the award ceremony for
the 2007 IUPAP Young Scientist Award.


title: Dark Energy: back to Newton?

abstract:
  Dark Energy is currently one of the biggest mysteries in science. In this
article the origin of the concept is traced as far back as Newton and Hooke in
the seventeenth century. Newton considered, along with the inverse square law,
a force of attraction that varies linearly with distance. A direct link can be
made between this term and Einstein's cosmological constant, Lambda, and this
leads to a possible relation between Lambda and the total mass of the universe.
Mach's influence on Einstein is discussed and the convoluted history of Lambda
throughout the last ninety years is coherently presented.


title: Di-pion emission in heavy quarkonia decays

abstract:
  The di-pion spectrum for the $\Upsilon(nS) \to \Upsilon (n'S))$ transition
with $n\leq 4$ has the form $\frac{dw}{dq}\sim $ (phase space) $ |\eta-x|^2$,
with $x=\frac{q^2-4m^2_\pi}{(\Delta M)^2 -4 m^2_\pi}< q^2 \equiv M^2_{\pi\pi},
$ and $\Delta M=M(nS) -M(n'S)$. The parameter $\eta $ is calculated and the
spectrum is shown to reproduce the experimental data for all 3 types of decays:
$3\to 1, 2\to 1$ and $3\to 2$ with $\eta \approx 0.5; 0$, and -3, respectively.


title:
An Outer Planet Beyond Pluto and Origin of the Trans-Neptunian Belt
  Architecture

abstract:
  Trans-Neptunian objects (TNOs) are remnants of a collisionally and
dynamically evolved planetesimal disk in the outer solar system. This complex
structure, known as the trans-Neptunian belt (or Edgeworth-Kuiper belt), can
reveal important clues about disk properties, planet formation, and other
evolutionary processes. In contrast to the predictions of accretion theory,
TNOs exhibit surprisingly large eccentricities, e, and inclinations, i, which
can be grouped into distinct dynamical classes. Several models have addressed
the origin and orbital evolution of TNOs, but none have reproduced detailed
observations, e.g., all dynamical classes and peculiar objects, or provided
insightful predictions. Based on extensive simulations of planetesimal disks
with the presence of the four giant planets and massive planetesimals, we
propose that the orbital history of an outer planet with tenths of Earth's mass
can explain the trans-Neptunian belt orbital structure. This massive body was
likely scattered by one of the giant planets, which then stirred the primordial
planetesimal disk to the levels observed at 40-50 AU and truncated it at about
48 AU before planet migration. The outer planet later acquired an inclined
stable orbit (>100 AU; 20-40 deg) because of a resonant interaction with
Neptune (an r:1 or r:2 resonance possibly coupled with the Kozai mechanism),
guaranteeing the stability of the trans-Neptunian belt. Our model consistently
reproduces the main features of each dynamical class with unprecedented detail;
it also satisfies other constraints such as the current small total mass of the
trans-Neptunian belt and Neptune's current orbit at 30.1 AU. We also provide
observationally testable predictions.


title:
Fluctuation induced quantum interactions between compact objects and a
  plane mirror

abstract:
  The interaction of compact objects with an infinitely extended mirror plane
due to quantum fluctuations of a scalar or electromagnetic field that scatters
off the objects is studied. The mirror plane is assumed to obey either
Dirichlet or Neumann boundary conditions or to be perfectly reflecting. Using
the method of images, we generalize a recently developed approach for compact
objects in unbounded space [1,2] to show that the Casimir interaction between
the objects and the mirror plane can be accurately obtained over a wide range
of separations in terms of charge and current fluctuations of the objects and
their images. Our general result for the interaction depends only on the
scattering matrices of the compact objects. It applies to scalar fields with
arbitrary boundary conditions and to the electromagnetic field coupled to
dielectric objects. For the experimentally important electromagnetic Casimir
interaction between a perfectly conducting sphere and a plane mirror we present
the first results that apply at all separations. We obtain both an asymptotic
large distance expansion and the two lowest order correction terms to the
proximity force approximation. The asymptotic Casimir-Polder potential for an
atom and a mirror is generalized to describe the interaction between a
dielectric sphere and a mirror, involving higher order multipole
polarizabilities that are important at sub-asymptotic distances.


title: Hadrons in Nuclei -- from High (200 GeV) to Low (1 GeV) energies

abstract:
  The study of the interaction of hadrons, produced by elementary probes in a
nucleus, with the surrounding nuclear medium can give insight into two
important questions. First, at high energies, the production process, the
time-scales connected with it and the prehadronic interactions can be studied
by using the nuclear radius as a length-scale. We do this here by analyzing
data from the EMC and HERMES experiements on nuclear attenuation. Second, at
low energies the spectral function, and thus the selfenergy of the produced
hadron, can be studied. Specifically, we analyze the CBELSA/TAPS data on
$\omega$ production in nuclei and discuss the importance of understanding
in-medium effects both on the primary production cross section and the final
state branching ratio. In both of these studies an excellent control of the
final state interactions is essential.


title:
Noncommutative Analogs of Monomial Symmetric Functions, Cauchy Identity,
  and Hall Scalar Product

abstract:
  This paper introduces noncommutative analogs of monomial symmetric functions
and fundamental noncommutative symmetric functions. The expansion of ribbon
Schur functions in both of these basis is nonnegative. With these functions at
hand, one can derive a noncommutative Cauchy identity as well as study a
noncommutative scalar product implied by Cauchy identity. This scalar product
seems be the noncommutative analog of Hall scalar product in the commutative
theory.


title: Wrinkled fibrations on near-symplectic manifolds

abstract:
  Motivated by the programmes initiated by Taubes and Perutz, we study the
geometry of near-symplectic 4-manifolds, i.e., manifolds equipped with a closed
2-form which is symplectic outside a union of embedded 1-dimensional
submanifolds, and broken Lefschetz fibrations on them. We present a set of four
moves which allow us to pass from any given fibration to any other broken
fibration which is deformation equivalent to it. Moreover, we study the change
of the near-symplectic geometry under each of these moves. The arguments rely
on the introduction of a more general class of maps, which we call wrinkled
fibrations and which allow us to rely on classical singularity theory.Finally,
we illustrate these constructions by showing how one can merge components of
the zero-set of the near-symplectic form. We also disprove a conjecture of Gay
and Kirby by showing that any achiral broken Lefschetz fibration can be turned
into a broken Lefschetz fibration by applying a sequence of our moves.


title:
The influence of coronal EUV irradiance on the emission in the He I
  10830 A and D3 multiplets

abstract:
  Two of the most attractive spectral windows for spectropolarimetric
investigations of the physical properties of the plasma structures in the solar
chromosphere and corona are the ones provided by the spectral lines of the He I
10830 A and 5876 A (or D3) multiplets, whose polarization signals are sensitive
to the Hanle and Zeeman effects. However, in order to be able to carry out
reliable diagnostics, it is crucial to have a good physical understanding of
the sensitivity of the observed spectral line radiation to the various
competing driving mechanisms. Here we report a series of off-the-limb non-LTE
calculations of the He I D3 and 10830 A emission profiles, focusing our
investigation on their sensitivity to the EUV coronal irradiation and the model
atmosphere used in the calculations. We show in particular that the intensity
ratio of the blue to the red components in the emission profiles of the He I
10830 A multiplet turns out to be a good candidate as a diagnostic tool for the
coronal irradiance. Measurements of this observable as a function of the
distance to the limb and its confrontation with radiative transfer modeling
might give us valuable information on the physical properties of the solar
atmosphere and on the amount of EUV radiation at relevant wavelengths
penetrating the chromosphere from above.


title: Real and integral structures in quantum cohomology I: toric orbifolds

abstract:
  We study real and integral structures in the space of solutions to the
quantum differential equations. First we show that, under mild conditions, any
real structure in orbifold quantum cohomology yields a pure and polarized
tt^*-geometry near the large radius limit. Secondly, we use mirror symmetry to
calculate the "most natural" integral structure in quantum cohomology of toric
orbifolds. We show that the integral structure pulled back from the singularity
B-model is described only in terms of topological data in the A-model; K-group
and a characteristic class. Using integral structures, we give a natural
explanation why the quantum parameter should specialize to a root of unity in
Ruan's crepant resolution conjecture.


title:
PT-invariance and representations of the Temperley-Lieb algebra on the
  unit circle

abstract:
  We present in detail a recent conjecture on self-adjoint representations of
the Temperley-Lieb algebra for particular values on the unit circle. The
formulation in terms of graphical calculus is emphasized and discussed for
several examples. The role of PT (parity and time reversal) invariance is
highlighted as it might prove important for generalising the construction to
other cases.


title:
Optical properties of the charge-density-wave polychalcogenide compounds
  $R_2$Te$_5$ ($R$=Nd, Sm and Gd)

abstract:
  We investigate the rare-earth polychalcogenide $R_2$Te$_5$ ($R$=Nd, Sm and
Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption
spectrum we extract the excitation energy of the CDW gap and estimate the
fraction of the Fermi surface which is gapped by the formation of the CDW
condensate. In analogy to previous findings on the related $R$Te$_n$ (n=2 and
3) families, we establish the progressive closing of the CDW gap and the
moderate enhancement of the metallic component upon chemically compressing the
lattice.


title: Chern classes in Deligne cohomology for coherent analytic sheaves

abstract:
  In this article, we construct Chern classes in rational Deligne cohomology
for coherent sheaves on a smooth complex compact manifold. We prove that these
classes verify the functoriality property under pullbacks, the Whitney formula
and the Grothendieck-Riemann-Roch theorem for projective morphisms between
smooth complex compact manifolds.


title: On the dynamical breaking of chiral symmetry: a new mechanism

abstract:
  We consider a U(1) gauge theory, minimally coupled to a massless Dirac field,
where a higher-derivative term is added to the pure gauge sector, as in the
Lee-Wick models. We find that this term can trigger chiral symmetry breaking at
low energy in the weak coupling regime. Then, the fermion field acquires a mass
that turns out to be a function of both the energy scale associated to the
higher-derivative term and the gauge coupling. The dependence of the fermion
mass on the gauge coupling is non-perturbative. Extensions to SU(N) gauge
theories and fermion-scalar interactions are also analyzed, as well as to
theories with massive gauge fields. A few implications of these results in the
framework of quark-mass generation are discussed.


title: Central Compact Objects in Supernova Remnants

abstract:
  Central Compact Objects (CCOs) are a handful of soft X-ray sources located
close to the centers of Supernova Remnants and supposed to be young,
radio-quiet Isolated Neutron Stars (INSs). A clear understanding of their
physics would be crucial in order to complete our view of the birth properties
of INSs. We will review the phenomenologies of CCOs, underlining the most
important, recent results, and we will discuss the possible relationships of
such sources with other classes of INSs.


title: Magnetism and homogenization of micro-resonators

abstract:
  Arrays of cylindrical metal micro-resonators embedded in a dielectric matrix
were proposed by Pendry, et. al., in 1999 as a means of creating a microscopic
structure that exhibits strong bulk magnetic behavior at frequencies not
realized in nature. This behavior arises for H-polarized fields in the
quasi-static regime, in which the scale of the micro-structure is much smaller
than the free-space wavelength of the fields. We carry out both formal and
rigorous two-scale homogenization analyses, paying special attention to the
appropriate method of averaging, which does not involve the usual cell
averages. We show that the effective magnetic and dielectric coefficients
obtained by means of such averaging characterize a bulk medium that, to leading
order, produces the same scattering data as the micro-structured composite.


title:
On the Bakry-Emery criterion for linear diffusions and weighted porous
  media equations

abstract:
  The goal of this paper is to give a non-local sufficient condition for
generalized Poincar\'e inequalities, which extends the well-known Bakry-Emery
condition. Such generalized Poincar\'e inequalities have been introduced by W.
Beckner in the gaussian case and provide, along the Ornstein-Uhlenbeck flow,
the exponential decay of some generalized entropies which interpolate between
the $L^2$ norm and the usual entropy. Our criterion improves on results which,
for instance, can be deduced from the Bakry-Emery criterion and Holley-Stroock
type perturbation results. In a second step, we apply the same strategy to
non-linear equations of porous media type. This provides new interpolation
inequalities and decay estimates for the solutions of the evolution problem.
The criterion is again a non-local condition based on the positivity of the
lowest eigenvalue of a Schr\"odinger operator. In both cases, we relate the
Fisher information with its time derivative. Since the resulting criterion is
non-local, it is better adapted to potentials with, for instance, a
non-quadratic growth at infinity, or to unbounded perturbations of the
potential.


title:
Next-to-MLLA corrections to single inclusive kt-distributions and
  2-particle correlations in a jet

abstract:
  The hadronic kt-spectrum inside a high energy jet is determined including
corrections of relative magnitude O{\sqrt{\alpha_s}} with respect to the
Modified Leading Logarithmic Approximation (MLLA), in the limiting spectrum
approximation (assuming an infrared cut-off Q0 =Lambda_{QCD}) and beyond
Q_0\ne\Lambda_{QCD}. The results in the limiting spectrum approximation are
found to be, after normalization, in impressive agreement with preliminary
measurements by the CDF collaboration, unlike what occurs at MLLA, pointing out
small overall non-perturbative contributions. Within the same framework,
2-particle correlations inside a jet are also predicted at NMLLA and compared
to previous MLLA calculations.


title: Bicontinuous emulsions stabilized solely by colloidal particles

abstract:
  Recent large-scale computer simulations suggest that it may be possible to
create a new class of soft solids, called `bijels', by stabilizing and
arresting the bicontinuous interface in a binary liquid demixing via spinodal
decomposition using particles that are neutrally wetted by both liquids. The
interfacial layer of particles is expected to be semi-permeable, hence, if
realised, these new materials would have many potential applications, e.g. as
microreaction media. However, the creation of bijels in the laboratory faces
serious obstacles. In general, fast quench rates are necessary to bypass
nucleation, so that only samples with limited thickness can be produced, which
destroys the three-dimensionality of the putative bicontinuous network.
Moreover, even a small degree of unequal wettability of the particles by the
two liquids can lead to ill-characterised, `lumpy' interfacial layers and
therefore irreproducible material properties. Here we report a reproducible
protocol for creating three-dimensional samples of bijel in which the
interfaces are stabilized by essentially a single layer of particles. We
demonstrate how to tune the mean interfacial separation in these bijels, and
show that mechanically, they indeed behave as soft solids.


title: Large scale geometry of certain solvable groups

abstract:
  In this paper we provide the final steps in the proof, announced by
Eskin-Fisher-Whyte, of quasi-isometric rigidity of a class of non-nilpotent
polycyclic groups. To this end, we prove a rigidity theorem on the boundaries
of certain negatively curved homogeneous spaces and combine it with work of
Eskin-Fisher-Whyte and Peng on the structure of quasi-isometries of certain
solvable Lie groups.


title: On coherent systems of type (n,d,n+1) on Petri curves

abstract:
  We study coherent systems of type $(n,d,n+1)$ on a Petri curve $X$ of genus
$g\ge2$. We describe the geometry of the moduli space of such coherent systems
for large values of the parameter $\alpha$. We determine the top critical value
of $\alpha$ and show that the corresponding ``flip'' has positive codimension.
We investigate also the non-emptiness of the moduli space for smaller values of
$\alpha$, proving in many cases that the condition for non-emptiness is the
same as for large $\alpha$. We give some detailed results for $g\le5$ and
applications to higher rank Brill-Noether theory and the stability of kernels
of evaluation maps, thus proving Butler's conjecture in some cases in which it
was not previously known.


title: Loop diagrams in space with SU(2) fuzziness

abstract:
  The structure of loop corrections is examined in a scalar field theory on a
three dimensional space whose spatial coordinates are noncommutative and
satisfy SU(2) Lie algebra. In particular, the 2- and 4-point functions in
$\phi^4$ scalar theory are calculated at the 1-loop order. The theory is
UV-finite as the momentum space is compact. It is shown that the non-planar
corrections are proportional to a one dimensional $\delta$-function, rather
than a three dimensional one, so that in transition rates only the planar
corrections contribute.


title: Extended-Source Effect and Chromaticity in Two-Point-Mass Microlensing

abstract:
  We explore the sensitivity of two-point-mass gravitational microlensing to
the extended nature of the source star, as well as the related sensitivity to
its limb darkening. We demonstrate that the sensitive region, usually
considered to be limited to a source-diameter-wide band along the caustic, is
strongly expanded near cusps, most prominently along their outer axis. In the
case of multi-component caustics, facing cusps may form a region with a
non-negligible extended-source effect spanning the gap between them. We
demonstrate that for smaller sources the size of the sensitive region extending
from a cusp measured in units of source radii increases, scaling as the inverse
cube root of the radius. We study the extent of different sensitivity contours
and show that for a microlensed Galactic bulge giant the probability of
encountering at least a 1% extended-source effect is higher than the
probability of caustic crossing by 40-60% when averaged over a typical range of
lens-component separations, with the actual value depending on the mass ratio
of the components. We derive analytical expressions for the extended-source
effect and chromaticity for a source positioned off the caustic. These formulae
are more generally applicable to any gravitational lens with a sufficiently
small source. Using exactly computed amplifications we test the often used
linear-fold caustic approximation and show that it may lead to errors on the
level of a few percent even in near-ideal caustic-crossing events. Finally, we
discuss several interesting cases of observed binary and planetary microlensing
events and point out the importance of our results for the measurement of
stellar limb darkening from microlensing light curves.


title: Identification of functional information subgraphs in complex networks

abstract:
  We present a general information theoretic approach for identifying
functional subgraphs in complex networks where the dynamics of each node are
observable. We show that the uncertainty in the state of each node can be
expressed as a sum of information quantities involving a growing number of
correlated variables at other nodes. We demonstrate that each term in this sum
is generated by successively conditioning mutual informations on new measured
variables, in a way analogous to a discrete differential calculus. The analogy
to a Taylor series suggests efficient search algorithms for determining the
state of a target variable in terms of functional groups of other degrees of
freedom. We apply this methodology to electrophysiological recordings of
networks of cortical neurons grown it in vitro. Despite strong stochasticity,
we show that each cell's patterns of firing are generally explained by the
activity of a small number of other neurons. We identify these neuronal
subgraphs in terms of their mutually redundant or synergetic character and
reconstruct neuronal circuits that account for the state of each target cell.


title:
Representation theorems for backward doubly stochastic differential
  equations

abstract:
  In this paper we study the class of backward doubly stochastic differential
equations (BDSDEs, for short) whose terminal value depends on the history of
forward diffusion. We first establish a probabilistic representation for the
spatial gradient of the stochastic viscosity solution to a quasilinear
parabolic SPDE in the spirit of the Feynman-Kac formula, without using the
derivatives of the coefficients of the corresponding BDSDE. Then such a
representation leads to a closed-form representation of the martingale
integrand of BDSDE, under only standard Lipschitz condition on the
coefficients.


title:
Phase transition in the rich-get-richer mechanism due to finite-size
  effects

abstract:
  The rich-get-richer mechanism (agents increase their ``wealth'' randomly at a
rate proportional to their holdings) is often invoked to explain the Pareto
power-law distribution observed in many physical situations, such as the degree
distribution of growing scale free nets. We use two different analytical
approaches, as well as numerical simulations, to study the case where the
number of agents is fixed and finite (but large), and the rich-get-richer
mechanism is invoked a fraction r of the time (the remainder of the time wealth
is disbursed by a homogeneous process). At short times, we recover the Pareto
law observed for an unbounded number of agents. In later times, the (moving)
distribution can be scaled to reveal a phase transition with a Gaussian
asymptotic form for r < 1/2 and a Pareto-like tail (on the positive side) and a
novel stretched exponential decay (on the negative side) for r > 1/2.


title: Collisions with Black Holes and Deconfined Plasmas

abstract:
  We use AdS/CFT to investigate i) high energy collisions with balls of
deconfined plasma surrounded by a confining phase and ii) the rapid localized
heating of a deconfined plasma. Both of these processes are dual to collisions
with black holes, where they result in the nucleation of a new "arm" of the
horizon reaching out in the direction of the incident object. We study the
resulting non-equilibrium dynamics in a universal limit of the gravitational
physics which may indicate universal behavior of deconfined plasmas at large
N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii)
can nucleate surprisingly large bubbles of a higher temperature phase.


title:
Geometry as an object of experience: Kant and the missed debate between
  Poincar\'e and Einstein

abstract:
  Poincar\'e held the view that geometry is a convention and cannot be tested
experimentally. This position was apparently refuted by the general theory of
relativity and the successful confirmation of its predictions; unfortunately,
Poincar\'e did not live to defend his thesis. In this paper, I argue that: 1)
Contrary to what many authors have claimed, non-euclidean geometries do not
rule out Kant's thesis that space is a form of intuition given {\it a priori};
on the contrary, Euclidean geometry is the condition for the possibility of any
more general geometry. 2) The conception of space-time as a Riemannian manifold
is an extremely ingenious way to describe the gravitational field, but, as
shown by Utiyama in 1956, general relativity is actually the gauge theory
associated to the Lorentz group. Utiyama's approach does not rely on the
assumption that space-time is curved, though the equations of the gauge theory
are identical to those of general relativity. Thus, following Poincar\'e, it
can be claimed that it is only a matter of convention to describe the
gravitational field as a Riemannian manifold or as a gauge field in Euclidean
space.


title: Entanglement-Assisted Quantum Convolutional Coding

abstract:
  We show how to protect a stream of quantum information from decoherence
induced by a noisy quantum communication channel. We exploit preshared
entanglement and a convolutional coding structure to develop a theory of
entanglement-assisted quantum convolutional coding. Our construction produces a
Calderbank-Shor-Steane (CSS) entanglement-assisted quantum convolutional code
from two arbitrary classical binary convolutional codes. The rate and
error-correcting properties of the classical convolutional codes directly
determine the corresponding properties of the resulting entanglement-assisted
quantum convolutional code. We explain how to encode our CSS
entanglement-assisted quantum convolutional codes starting from a stream of
information qubits, ancilla qubits, and shared entangled bits.


title: Goldstone Bosons and Global Strings in a Warped Resolved Conifold

abstract:
  A warped resolved conifold background of type IIB theory, constructed in
hep-th/0701064, is dual to the supersymmetric $SU(N)\times SU(N)$ gauge theory
with a vacuum expectation value (VEV) for one of the bifundamental chiral
superfields. This VEV breaks both the superconformal invariance and the
baryonic symmetry. The absolute value of the VEV controls the resolution
parameter of the conifold. In this paper we study the phase of the VEV, which
corresponds to the Goldstone boson of the broken symmetry. We explicitly
construct the linearized perturbation of the 4-form R-R potential that contains
the Goldstone boson. On general grounds, the theory should contain global
strings which create a monodromy of the pseudoscalar Goldstone boson field. We
identify these strings with the $D3$-branes wrapping the two-cycle at the tip
of the warped resolved conifold.


title: How to Enhance Dephasing Time in Superconducting Qubits

abstract:
  We theoretically investigate the influence of designed pulse sequences in
restoring quantum coherence lost due to background noise in superconducting
qubits. We consider both 1/f noise and Random Telegraph Noise, and show that
the qubit coherence time can be substantially enhanced by carefully engineered
pulse sequences. Conversely, the time dependence of qubit coherence under
external pulse sequences could be used as a spectroscopic tool for extracting
the noise mechanisms in superconducting qubits, i.e. by using Uhrig's pulse
sequence one can obtain information about moments of the spectral density of
noise. We also study the effect of pulse sequences on the evolution of the
qubit affected by a strongly coupled fluctuator, and show that the non-Gaussian
features in decoherence are suppressed by the application of pulses.


title: Quadrupole Effect on the Heat Conductivity of Cold Glasses

abstract:
  At very low temperatures, the tunnelling theory for amorphous solids predicts
a thermal conductivity $\kappa\propto T^p$, with $p = 2$. We have studied the
effect of the Nuclear Quadrupole moment on the thermal conductivity of glasses
at very low temperatures. We developed a theory that couples the tunnelling
motion to the nuclear quadrupoles moment in order to evaluate the thermal
conductivity. Our result suggests a cross over between two different regimes at
the temperature close to the nuclear quadrupoles energy. Below this temperature
we have shown that the thermal conductivity is larger than the standard
tunneling result and therefore we have $p < 2$. However, for temperatures
higher than the nuclear quadrupoles energy, the result of standard tunnelling
model has been found.


title:
On the cuspidality of pullbacks of Siegel Eisenstein series and
  applications to the Bloch-Kato conjecture

abstract:
  Let $k > 3$ be an integer and $p$ a prime with $p > 2k-2$. Let $f$ be a
newform of weight $2k-2$ and level 1 so that $f$ is ordinary at $p$ and
$\bar{\rho}_{f}$ is irreducible. Under some additional hypotheses we prove that
$ord_{p}(L_{alg}(k,f)) \leq ord_{p}(# S)$ where $S$ is the Pontryagin dual of
the Selmer group associated to $\rho_{f} \otimes \epsilon^{1-k}$ with
$\epsilon$ the $p$-adic cyclotomic character. We accomplish this by first
constructing a congruence between the Saito-Kurokawa lift of $f$ and a non-CAP
Siegel cusp form. Once this congruence is established, we use Galois
representations to obtain the lower bound on the Selmer group.


title: Restoring Holographic Dark Energy in Brane Cosmology

abstract:
  We present a generalized version of holographic dark energy arguing that it
must be considered in the maximally subspace of a cosmological model. In the
context of brane cosmology it leads to a bulk holographic dark energy which
transfers its holographic nature to the effective 4D dark energy. As an
application we use a single-brane model and we show that in the low energy
limit the behavior of the effective holographic dark energy coincides with that
predicted by conventional 4D calculations. However, a finite bulk can lead to
radically different results.


title: Conway classification of alternating knots

abstract:
  The alternating knots, links and twists projected on the $S_2$ sphere were
identified with the phase space of a Hamiltonian dynamic system of one degree
of freedom. The saddles of the system correspond to the crossings, the edges
correspond to the stable and unstable manifolds connecting the saddles. Each
face is then oriented in one of two different senses determined by the
direction of these manifolds. This correspondence can be also realized between
the knot and the Poincar\'e section of a two degrees of freedom integrable
dynamical system. The crossings corresponding to unstable orbits, and the faces
to foliated torus, around a stable orbit.
  The associated matrix to that connected graph was decomposed in two
permutations. The separation was shown unique for knots not for links. The
characteristic polynomial corresponding to some knot, link or twist families
was explicitly computed in terms of Chebyschev polynomials. A classification of
rational knots was formulated in terms of the first derivative of the
polynomial of a knot computed in $x=2$, equal to the number of crossings of the
knot multiplying the same number used previously by Conway for tabulation of
knot properties. This leads to a classification of knots exemplified for the
families having up to five ribbons. We subdivide the families of $N$ ribbons in
subfamilies related to the prime knots of $N$ crossings.


title: Eta forms and determinant lines

abstract:
  We show that there is a canonical construction of a zeta (Bismut-Quillen)
connection on the determinant line bundle of a family of APS elliptic boundary
problems and that it has curvature equal to the 2-form part of a relative eta
form.


title: Trust for Location-based Authorisation

abstract:
  We propose a concept for authorisation using the location of a mobile device
and the enforcement of location-based policies. Mobile devices enhanced by
Trusted Computing capabilities operate an autonomous and secure location
trigger and policy enforcement entity. Location determination is two-tiered,
integrating cell-based triggering at handover with precision location
measurement by the device.


title: Electrostatic interactions between graphene layers and their environment

abstract:
  We analyze the electrostatic interactions between a single graphene layer and
a SiO$_2$ susbtrate, and other materials which may exist in its environment. We
obtain that the leading effects arise from the polar modes at the SiO$_2$
surface, and water molecules, which may form layers between the graphene sheet
and the substrate. The strength of the interactions implies that graphene is
pinned to the substrate at distances greater than a few lattice spacings. The
implications for graphene nanoelectromechanical systems, and for the
interaction between graphene and a STM tip are also considered.


title: Charmonium spectroscopy at BABAR

abstract:
  The charmonium-like states, Y(4260), Y(4350), produced via initial state
radiation, as well as the X(3872), and Y(3940), produced in B meson decays from
the BABAR B-factory are reviewed. These mesons do not seem consistent with
conventional charmonium models, and several alternate hypotheses have been
proposed to explain these new discoveries.


title: Geometry of the conics on the Minkowski plane

abstract:
  Conics in the Euclidean space have been known for their geometrical beauty
and also for their power to model several phenomena in real life. It usually
happens that when thinking about the conics in a semi-Riemannian manifold, the
equations and the graphs that come to mind are those of the quadratic Euclidean
equations. For example, a circle is always perceived like a closed curve. We
study the geometry of the conics in the semi-Riemannian Minkowski spacetime,
and interpret each equation with Euclidean eyes. By defining an extended
geometric completeness for conics, we will show that the conic completeness of
conics can be changed through a Euclidean mirror.


title: A Dynamic ID-based Remote User Authentication Scheme

abstract:
  Password-based authentication schemes are the most widely used techniques for
remote user authentication. Many static ID-based remote user authentication
schemes both with and without smart cards have been proposed. Most of the
schemes do not allow the users to choose and change their passwords, and
maintain a verifier table to verify the validity of the user login. In this
paper we present a dynamic ID-based remote user authentication scheme using
smart cards. Our scheme allows the users to choose and change their passwords
freely, and do not maintain any verifier table. The scheme is secure against
ID-theft, and can resist the reply attacks, forgery attacks, guessing attacks,
insider attacks and stolen verifier attacks.


title: Cosmic string loops: large and small, but not tiny

abstract:
  We develop an analytical model to study the production spectrum of loops in
the cosmic string network. In the scaling regime, we find two different scales
corresponding to large (one order below horizon) and small (few orders below
horizon) loops. The very small (tiny) loops at the gravitational back reaction
scale are absent, and thus, our model has no ultra-violet divergences. We
calculate the spectrum of loops and derive analytical expressions for the
positions and magnitudes of the small and large scale peaks. The small loops
are produced by large bursts of similar loops moving with very high velocities
in the same direction. We describe the shape of large loops, which would
usually consist of few kinks and few cusps per oscillation cycle. We also argue
that the typical size of large loops is set by the correlation length, which
does not depend on the intercommutation probability p, while the interstring
distance scales as p^{1/3}.


title: Localization of nonlocal theories

abstract:
  We show that a certain class of nonlocal scalar models, with a kinetic
operator inspired by string field theory, is equivalent to a system which is
local in the coordinates but nonlocal in an auxiliary evolution variable. This
system admits both Lagrangian and Hamiltonian formulations, and its Cauchy
problem and quantization are well-defined. We classify exact nonperturbative
solutions of the localized model which can be found via the diffusion equation
governing the fields.


title: Identification of Spinning Dust in Halpha-Correlated Microwave Emission

abstract:
  CMB experiments commonly use maps of Halpha intensity as a spatial template
for Galactic free-free emission, assuming a power law I_nu \propto nu^-0.15 for
the spectrum. Any departure from the assumed free-free spectrum could have a
detrimental effect on determination of the primary CMB anisotropy. We show that
the Halpha-correlated emission spectrum in the diffuse warm ionized medium
(WIM) is not the expected free-free spectrum at WMAP frequencies. Instead,
there is a broad bump in the spectrum at ~50 GHz which is consistent with
emission from spinning dust grains. Spectra from both the full sky and smaller
regions of interest are well fit by a superposition of a free-free and WIM
Draine & Lazarian (1998) spinning dust model, shifted in frequency. The
spinning dust emission is ~5 times weaker than the free-free component at 50
GHz, with the null hypothesis that the Halpha-correlated spectrum is pure
free-free, ruled out at >8 sigma in all regions and >100 sigma for the full sky
fit.


title:
Go Long, Go Deep: Finding Optical Jet Breaks for Swift-Era GRBs with the
  LBT

abstract:
  Using the 8.4m Large Binocular Telescope, we observed six GRB afterglows from
2.8 hours to 30.8 days after the burst triggers to systematically probe the
late time behaviors of afterglows including jet breaks, flares, and supernova
bumps. We detected five afterglows with Sloan r' magnitudes ranging from
23.0-26.3 mag. The depth of our observations allows us to extend the temporal
baseline for measuring jet breaks by another decade in time scale. We detected
two jet breaks and a third candidate, all of which are not detectable without
deep, late time optical observations. In the other three cases, we do not
detect the jet breaks either because of contamination from the host galaxy
light, the presence of a supernova bump, or the intrinsic faintness of the
optical afterglow.
  This suggests that the basic picture that GRBs are collimated is still valid
and that the apparent lack of Swift jet breaks is due to poorly sampled
afterglow light curves, particularly at late times.


title: Observational Selection Effects in Quantum Cosmology

abstract:
  Scientific theories need to be testable by observations, say using Bayes'
theorem. A complete theory needs at least the three parts of dynamical laws for
specified physical variables, the correct solution of the dynamical laws
(boundary conditions), and the connection with observations or experience or
conscious perceptions (laws of psycho-physical parallelism). Principles are
proposed for Bayesian meta-theories. One framework that obeys these principles
is Sensible Quantum Mechanics (SQM), which is discussed. In principle, it
allows one to test between single-history and many-worlds theories, and to
discuss threats to certain theories from fake universes and Boltzmann brains.
The threat of fake universes may be dismissed if one doubts the
substrate-independence of consciousness, which seems very implausible in the
SQM framework. Boltzmann brains seem more problematic, though there are many
conceivable solutions. SQM also suggests the possibility that past steps along
our evolutionary ancestry may be so rare that they have occurred nowhere else
within the part of the universe that we can observe.


title: On the newly discovered Canes Venatici II dSph galaxy

abstract:
  We report on the detection of variable stars in the Canes Venatici II (CVn
II) dwarf spheroidal galaxy, a new satellite of the Milky Way recently
discovered by the Sloan Digital Sky Survey. We also present a V, B-V
color-magnitude diagram that reaches V = 25.5 mag, showing the galaxy's main
sequence turn off at V = 24.5 mag and revealing several candidate blue
straggler stars. Two RR Lyrae stars have been identified within the half-light
radius of CVn II,a fundamental-mode variable (RRab) with period P_ab = 0.743
days, and a first-overtone (RRc) RR Lyrae star with P_c = 0.358 days. The
rather long periods of these variables along with their position on the
period-amplitude diagram support an Oosterhoff type II classification for CVn
II. The average apparent magnitude of the RR Lyrae stars, <V> = 21.48 +/- 0.02
mag, is used to obtain a precision distance modulus of mu_0 = 21.02 +/- 0.06
mag and a corresponding distance of 160(+4,-5} kpc, for an adopted reddening
E(B-V) = 0.015 mag.


title:
On Signatures of Atmospheric Features in Thermal Phase Curves of Hot
  Jupiters

abstract:
  Turbulence is ubiquitous in Solar System planetary atmospheres. In hot
Jupiter atmospheres, the combination of moderately slow rotation and thick
pressure scale height may result in dynamical weather structures with unusually
large, planetary-size scales. Using equivalent-barotropic, turbulent
circulation models, we illustrate how such structures can generate a variety of
features in the thermal phase curves of hot Jupiters, including phase shifts
and deviations from periodicity. Such features may have been spotted in the
recent infrared phase curve of HD 189733b. Despite inherent difficulties with
the interpretation of disk-integrated quantities, phase curves promise to offer
unique constraints on the nature of the circulation regime present on hot
Jupiters.


title: On interactions of higher spin fields with gravity and branes in AdS_5

abstract:
  We construct actions of higher spin fields interacting with gravity on AdS_5
backgrounds such that the Compton scattering amplitudes of the interaction are
tree-level unitary. We then consider higher-spin fields in the Randall-Sundrum
scenario. There, in the fermionic case, we construct a tree-level unitary
action of higher spin fields interacting with branes and linearised gravity. In
the bosonic case we show that this is not in general possible. A tree-level
unitary action of bosonic higher spins interacting with linearised gravity and
branes is only possible in the following cases: The brane is a pure tension
brane and/or Dirichlet boundary conditions are imposed thereby making bosonic
higher spin fields invisible to a brane observer. We finally show that higher
spins in Randall-Sundrum II braneworlds can only be produced by (decay into)
gravitons at trans-Planckian scales. We end by commenting on the possible
relevance of higher-spin unparticles as Dark Matter candidates.


title: How to Create a New Integer Sequence

abstract:
  There are several standard procedures used to create new sequences from a
given sequence or from a given pair of sequences. In this paper I discuss the
most popular of these procedures. For each procedure, I give a definition and
provide examples based on three famous sequences: the natural numbers, the
prime numbers and the Fibonacci numbers. I also add my thoughts on what makes a
sequence interesting. My goal is to help my readers invent new sequences,
differentiate interesting sequences from boring ones, and better understand
sequences they encounter.


title:
Exact and Approximate Expressions for the Probability of Undetected
  Error of Varshamov-Tenengol'ts Codes

abstract:
  Computation of the undetected error probability for error correcting codes
over the Z-channel is an important issue, explored only in part in previous
literature. In this paper we consider the case of Varshamov-Tenengol'ts codes,
by presenting some analytical, numerical, and heuristic methods for unveiling
this additional feature. Possible comparisons with Hamming codes are also shown
and discussed.


title:
Non-commutative Schur-Horn theorems and extended majorization for
  hermitian matrices

abstract:
  Let $\mathcal A\subseteq \mat$ be a unital $*$-subalgebra of the algebra
$\mat$ of all $n\times n$ complex matrices and let $B$ be an hermitian matrix.
Let $\U_n(B)$ denote the unitary orbit of $B$ in $\mat$ and let $\mathcal
E_\mathcal A$ denote the trace preserving conditional expectation onto
$\mathcal A$. We give an spectral characterization of the set $$ \mathcal
E_\mathcal A(\U_n(B))=\{\mathcal E_\mathcal A(U^* B U): U\in \mat,\
\text{unitary matrix}\}.$$ We obtain a similar result for the contractive orbit
of a positive semi-definite matrix $B$. We then use these results to extend the
notions of majorization and submajorization between self-adjoint matrices to
spectral relations that come together with extended (non-commutative)
Schur-Horn type theorems.


title: Lattice Boltzmann method for inhomogeneous fluids

abstract:
  We present a lattice-based numerical method to describe the non equilibrium
behavior of a simple fluid under non-uniform spatial conditions. The evolution
equation for the one-particle phase-space distribution function is derived
starting from a microscopic description of the system. It involves a series of
approximations which are similar to those employed in theories of inhomogeneous
fluids, such as Density Functional theory. Among the merits of the present
approach: the possibility to determine the equation of state of the model, the
transport coefficients and to provide an efficient method of numerical solution
under non-uniform conditions. The algorithm is tested in a particular non
equilibrium situation, namely the steady flow of a hard-sphere fluid across a
narrow slit. Pronounced non-hydrodynamic oscillations in the density and
velocity profiles are found.


title: Phase-space approach to dynamical density functional theory

abstract:
  We consider a system of interacting particles subjected to Langevin inertial
dynamics and derive the governing time-dependent equation for the one-body
density. We show that, after suitable truncations of the
Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, and a multiple time scale
analysis, we obtain a self-consistent equation involving only the one-body
density. This study extends to arbitrary dimensions previous work on a
one-dimensional fluid and highlights the subtelties of kinetic theory in the
derivation of dynamical density functional theory.


title:
Measurement of D0-anti-D0 Mixing using the Ratio of Lifetimes for the
  Decays D0 --> K-pi+, K-K+, and pi-pi+

abstract:
  We present a measurement of $D^0$-$\bar{D^0}$ mixing parameters using the
ratios of lifetimes extracted from a sample of $D^0$ mesons produced through
the process $D^{*+}\to\D^0\pi^+$, that decay to $K^{+}\pi^{-}$, K^{-}K^{+}$, or
$\pi^-\pi^+$. The Cabibbo-suppressed modes $K^{-}K^{+}$ and $\pi^-\pi^+$ are
compared to the Cabibbo-favored mode $K^{+}\pi^{-}$ to obtain a measurement of
$y_{CP}$, which in the limit of CP conservation corresponds to the mixing
parameter $y$. The analysis is based on a data sample of 384 $fb^{-1}$
collected by the $BaBar$ detector at the PEP-II asymmetric-energy $e^+e^-$
collider. We obtain $y_{CP} = [1.24\pm 0.39\mathrm{(stat)} \pm
0.13\mathrm{(syst)}]%$, which is evidence of $D^0$-$\bar{D^0}$ mixing at the
$3\sigma$ level, and $\Delta Y = [-0.26\pm 0.36\mathrm{(stat)} \pm 0.08
\mathrm{(syst)}]%$, where $\Delta Y$ constrains possible CP violation.
Combining this result with a previous $BaBar$ measurement of $y_{CP}$ obtained
from a separate sample of $D^0\to K^{-}K^{+}$ events, we obtain $y_{CP} =
[1.03\pm 0.33 \mathrm{(stat)} \pm 0.19 \mathrm{(syst)}]%$.