title: Vacuum Stress and Closed Paths in Rectangles, Pistons, and Pistols

abstract:
  Rectangular cavities are solvable models that nevertheless touch on many of
the controversial or mysterious aspects of the vacuum energy of quantum fields.
This paper is a thorough study of the two-dimensional scalar field in a
rectangle by the method of images, or closed classical (or optical) paths,
which is exact in this case. For each point r and each specularly reflecting
path beginning and ending at r, we provide formulas for all components of the
stress tensor T_{\mu\nu}(r), for all values of the curvature coupling constant
\xi and all values of an ultraviolet cutoff parameter. Arbitrary combinations
of Dirichlet and Neumann conditions on the four sides can be treated. The total
energy is also investigated, path by path. These results are used in an attempt
to clarify the physical reality of the repulsive (outward) force on the sides
of the box predicted by calculations that neglect both boundary divergences and
the exterior of the box. Previous authors have studied "piston" geometries that
avoid these problems and have found the force to be attractive. We consider a
"pistol" geometry that comes closer to the original problem of a box with a
movable lid. We find again an attractive force, although its origin and
detailed behavior are somewhat different from the piston case. However, the
pistol (and the piston) model can be criticized for extending idealized
boundary conditions into short distances where they are physically implausible.
Therefore, it is of interest to see whether leaving the ultraviolet cutoff
finite yields results that are more plausible. We then find that the force
depends strongly on a geometrical parameter; it can be made repulsive, but only
by forcing that parameter into the regime where the model is least convincing
physically.


title: Polynomial stochastic games via sum of squares optimization

abstract:
  Stochastic games are an important class of problems that generalize Markov
decision processes to game theoretic scenarios. We consider finite state
two-player zero-sum stochastic games over an infinite time horizon with
discounted rewards. The players are assumed to have infinite strategy spaces
and the payoffs are assumed to be polynomials. In this paper we restrict our
attention to a special class of games for which the single-controller
assumption holds. It is shown that minimax equilibria and optimal strategies
for such games may be obtained via semidefinite programming.


title: Electromagnetic Spin-Orbit Interactions via Scattering

abstract:
  The longitudinal components of orthogonal-circularly polarized fields carry a
phase singularity that changes sign depending on the polarization handedness.
The addition of orbital angular momentum adds to or cancels this singularity
and results in polarization-dependent scattering through round and square
apertures, which we demonstrate analytically, numerically, and experimentally.
By preparing the incident polarization and arranging the configuration of
sub-wavelength apertures, we produce shadow-side scattered fields with
arbitrary phase vorticity.


title: M dwarfs: effective temperatures, radii and metallicities

abstract:
  We empirically determine effective temperatures and bolometric luminosities
for a large sample of nearby M dwarfs, for which high accuracy optical and
infrared photometry is available.
  We introduce a new technique which exploits the flux ratio in different bands
as a proxy of both effective temperature and metallicity. Our temperature scale
for late type dwarfs extends well below 3000 K (almost to the brown dwarf
limit) and is supported by interferometric angular diameter measurements above
3000 K. Our metallicities are in excellent agreement (usually within 0.2 dex)
with recent determinations via independent techniques. A subsample of cool M
dwarfs with metallicity estimates based on hotter Hipparcos common
proper-motion companions indicates our metallicities are also reliable below
3000 K, a temperature range unexplored until now.
  The high quality of our data allow us to identify a striking feature in the
bolometric luminosity versus temperature plane, around the transition from K to
M dwarfs. We have compared our sample of stars with theoretical models and
conclude that this transition is due to an increase in the radii of the M
dwarfs, a feature which is not reproduced by theoretical models.


title:
Forward-Backward Asymmetry in Top Quark Production in ppbar Collisions
  at sqrt{s}=1.96 TeV

abstract:
  Reconstructable final state kinematics and charge assignment in the reaction
ppbar->ttbar allows tests of discrete strong interaction symmetries at high
energy. We define frame dependent forward-backward asymmetries for the outgoing
top quark in both the ppbar and ttbar rest frames, correct for experimental
distortions, and derive values at the parton-level. Using 1.9/fb of ppbar
collisions at sqrt{s}=1.96 TeV recorded with the CDF II detector at the
Fermilab Tevatron, we measure forward-backward top quark production asymmetries
in the ppbar and ttbar rest frames of A_{FB,pp} = 0.17 +- 0.08 and A_{FB,tt} =
0.24 +- 0.14.


title:
Principal eigenvalues and an anti-maximum principle for homogeneous
  fully nonlinear elliptic equations

abstract:
  We study the fully nonlinear elliptic equation $F(D^2u,Du,u,x) = f$ in a
smooth bounded domain $\Omega$, under the assumption the nonlinearity $F$ is
uniformly elliptic and positively homogeneous. Recently, it has been shown that
such operators have two principal "half" eigenvalues, and that the
corresponding Dirichlet problem possesses solutions, if both of the principal
eigenvalues are positive. In this paper, we prove the existence of solutions of
the Dirichlet problem if both principal eigenvalues are negative, provided the
"second" eigenvalue is positive, and generalize the anti-maximum principle of
Cl\'{e}ment and Peletier to homogeneous, fully nonlinear operators.


title:
Low-lying excitations of the three-leg spin tube using the
  density-matrix renormalization group method

abstract:
  Using the (dynamical) density-matrix renormalization group method, we study
the low-energy physics of three-leg antiferromagnetic Heisenberg model where
the periodic boundary conditions are applied in the rung direction. We confirm
that the spin excitations are always gapped as long as the intra-ring couplings
form a regular triangle. From precise finite-size-scaling analyses of the spin
gap and dimerization order parameter, we also find that the spin gap is
collapsed by very small asymmetric modulation of the intra-ring couplings.
Moreover, the dynamical spin structure factors on the intra- and inter-leg
correlations are calculated. It is demonstrated that the low-lying structure of
the inter-leg spectra is particularly affected by the asymmetric modulation.


title:
A mean-field theory for self-propelled particles interacting by velocity
  alignment mechanisms

abstract:
  A mean-field approach (MFA) is proposed for the analysis of orientational
order in a two-dimensional system of stochastic self-propelled particles
interacting by local velocity alignment mechanism. The treatment is applied to
the cases of ferromagnetic (F) and liquid-crystal (LC) alignment. In both
cases, MFA yields a second order phase transition for a critical noise strength
and a scaling exponent of 1/2 for the respective order parameters. We find that
the critical noise amplitude $\eta_c$ at which orientational order emerges in
the LC case is smaller than in the F-alignment case, i.e.
$\eta^{LC}_{C}<\eta^{F}_{C}$. A comparison with simulations of individual-based
models with F- resp. LC-alignment shows that the predictions about the critical
behavior and the qualitative relation between the respective critical noise
amplitudes are correct.


title:
Finite-Temperature Scaling of Magnetic Susceptibility and Geometric
  Phase in the XY Spin Chain

abstract:
  We study the magnetic susceptibility of 1D quantum XY model, and show that
when the temperature approaches zero, the magnetic susceptibility exhibits the
finite-temperature scaling behavior. This scaling behavior of the magnetic
susceptibility in 1D quantum XY model, due to the quantum-classical mapping,
can be easily experimentally tested. Furthermore, the universality in the
critical properties of the magnetic susceptibility in quantum XY model is
verified. Our study also reveals the close relation between the magnetic
susceptibility and the geometric phase in some spin systems, where the quantum
phase transitions are driven by an external magnetic field.


title: Free field realization of the $osp(2n|2n)$ current algebra

abstract:
  The $osp(2n|2n)$ current algebra for a {\it generic} positive integer $n$ at
general level $k$ is investigated. Its free field representation and
corresponding energy-momentum tensor are constructed. The associated screening
currents of the first kind are also presented.


title:
The effect of localized new Higgs doublet on the radiative lepton flavor
  violating decays in the Randall Sundrum background

abstract:
  We study the radiative lepton flavor violating l_1->l_2\gamma decays in the
two Higgs doublet model with localized new Higgs doublet in the Randall Sundrum
background. We estimate the contributions of the KK modes of new Higgs bosons
and left (right) handed charged lepton doublets (singlets) on the branching
ratios of the decays considered. We observe that there is an enhancement in the
branching ratios with the addition of new Higgs boson and lepton KK modes.


title:
Interplay of Local-Moment Ferromagnetism and Superconductivity in
  ErRh$_4$B$_4$ Single Crystals

abstract:
  Tunnel-diode resonator technique was used to study crystals of ferromagnetic
re-entrant superconductor, ErRh$_{4}$B$_{4}$. At the boundary between
ferromagnetism (FM) and superconductivity (SC), dynamic magnetic
susceptibility, $\chi(T,H)$, exhibits highly asymmetric behavior upon warming
and cooling as well as enhanced diamagnetism on the SC side. SC phase nucleates
upon warming in a cascade of discontinuous jumps in magnetic susceptibility
$\chi(T,H)$, whereas FM phase develops gradually as reported in detail in
\cite{prozorov2008}. Here we further investigate enhanced diamagnetism. We find
that when a magnetic field is applied along the magnetic easy axes, a region of
enhanced diamagnetic screening is smaller than in the perpendicular
orientation. A discussion of possible causes of this effect is provided.


title:
Howe duality and Kostant Homology Formula for infinite-dimensional Lie
  superalgebras

abstract:
  Using Howe duality we compute explicitly Kostant-type homology groups for a
wide class of representations of the infinite-dimensional Lie superalgebra
$\hat{\frak{gl}}_{\infty|\infty}$ and its classical subalgebras at positive
integral levels. We also obtain Kostant-type homology formulas for the Lie
algebra $ widehat{\frak{gl}}_\infty$ at negative integral levels. We further
construct resolutions in terms of generalized Verma modules for these
representations.


title:
Black Holes in the Dilatonic Einstein-Gauss-Bonnet Theory in Various
  Dimensions I -- Asymptotically Flat Black Holes --

abstract:
  We study spherically symmetric, asymptotically flat black hole solutions in
the low-energy effective heterotic string theory, which is the Einstein gravity
with Gauss-Bonnet term and the dilaton, in various dimensions. We derive the
field equations for suitable ansatz for general D dimensions and construct
black hole solutions of various masses numerically in D=4,5,6 and 10
dimensional spacetime with (D-2)-dimensional hypersurface with positive
constant curvature. A detailed comparison with the non-dilatonic solutions is
made. We also examine the thermodynamic properties of the solutions. It is
found that the dilaton has significant effects on the black hole solutions, and
we discuss physical consequences.


title:
Nonlinear Evolution of Gravitational Fragmentation Regulated by Magnetic
  Fields and Ambipolar Diffusion

abstract:
  We present results from an extensive set of simulations of gravitational
fragmentation in the presence of magnetic fields and ambipolar diffusion. The
average fragmentation spacing in the nonlinear phase of evolution is in
excellent agreement with the prediction of linear perturbation theory. The time
scale for nonlinear growth and runaway of the first core is $\approx 10$ times
the calculated growth time $\taugm$ of the eigenmode with minimum growth time,
when starting from a uniform background state with small-amplitude white-noise
perturbations. Subcritical and transcritical models typically evolve on a
significantly longer time scale than the supercritical models. Infall motions
in the nonlinear fully-developed contracting cores are subsonic on the core
scale in subcritical and transcritical clouds, but are somewhat supersonic in
supercritical clouds. Core mass distributions are sharply peaked with a steep
decline to large masses, consistent with the existence of a preferred mass
scale for each unique set of dimensionless free parameters. However, a sum
total of results for various initial mass-to-flux ratios yields a broad
distribution reminiscent of observed core mass distributions. Based on our
results, we conclude that fragmentation spacings, magnitude of infall motions,
core shapes, and, especially, the curvature of magnetic field morphology, may
serve as indirect observational means of determining a cloud's ambient
mass-to-flux ratio.


title: Localization-delocalization transition of a polaron near an impurity

abstract:
  We solve the problem of polaron localization on an attractive impurity by
means of direct-space Diagrammatic Monte Carlo implemented for the system in
the thermodynamic limit. In particular we determine the ground state phase
diagram in dependence on the electron-phonon coupling and impurity potential
strength for the whole phonon frequency range. Including the quantum phonon
dynamics we find and characterize a new phase which is missing in the zero
phonon-frequency limit (adiabatic approximation), where self-trapped polarons
are not localized at shallow impurities. We predict and show that in the
vicinity of the localization transition a region with a mixture of weak- and
strong-coupling spectral response is realized.


title:
The Fano effect in the point contact spectroscopy of heavy electron
  materials

abstract:
  We show that Fano interference explains how point contact spectroscopy in
heavy electron materials probes the emergence of the Kondo heavy electron
liquid below the same characteristic temperature T* as that seen in many other
experiments, and why the resulting measured conductance asymmetry reflects the
universal Kondo liquid behavior seen in these. Its physical origin is the
opening of a new channel for electron tunneling beyond that available from the
background conduction electrons. We propose a simple phenomenological
expression for the resulting Fano interference that provides a good fit to the
experimental results for CeCoIn$_5$, CeRhIn$_5$ and YbAl$_3$, over the entire
range of bias voltages, and deduce a life-time of the heavy quasiparticle
excitations that agrees well with recent state-of-the-art numerical
calculations.


title:
Supermassive Black Hole Masses in Type II Active Galactic Nuclei with
  Polarimetric Broad Emission Lines

abstract:
  Type II AGNs with polarimetric broad emission line provided strong evidence
for the orientation-based unified model for AGNs. We want to investigate
whether the polarimetric broad emission line in type II AGNs can be used to
calculate their central supermassive black hole (SMBH) masses, like that for
type I AGNs. We collected 12 type II AGNs with polarimetric broad emission line
width from the literatures, and calculated their central black hole masses from
the polarimetric broad line width and the isotropic \oiii luminosity. We also
calculate the mass from stellar velocity dispersion, $\sigma_*$, with the
$\mbh-\sigma_*$ relation.We find that: (1) the black hole masses derived from
the polarimetric broad line width is averagely larger than that from the $\mbh-
\sigma_*$ relation by about 0.6 dex, (2) If these type II AGNs follow
$\mbh-\sigma_*$ relation, we find that the random velocity can't not be omitted
and is comparable with the BLRs Keplerian velocity. It is consistent with the
scenery of large outflow from the accretion disk suggested by Yong et al.


title:
On sums of figurate numbers by using techniques of poset representation
  theory

abstract:
  We use representations and differentiation algorithms of posets, in order to
obtain results concerning unsolved problems on figurate numbers. In particular,
we present criteria for natural numbers which are the sum of three octahedral
numbers, three polygonal numbers of positive rank or four cubes with two of
them equal. Some identities of the Rogers-Ramanujan type involving this class
of numbers are also obtained.


title: Electron - Dark Matter Scattering in an Evacuated Tube

abstract:
  The light dark matter model can explain both the primordial abundance of dark
matter and the anomalous 511 keV gamma-ray signal from the galactic center.
This model posits a light neutral scalar, \chi, with a mass in the range 1 MeV
< Mchi < 10 MeV, as well as a light neutral spin-1 boson, U, which mediates the
annihilation channel \chi\chi -> e+e-. Since the dark matter particle is light,
its number density is relatively large if it accounts for a local dark matter
density of 0.3 GeV/cm^3. We consider an experiment in which a low-energy,
high-current electron beam is passed through a long evacuated tube, and elastic
scattering of electrons off dark matter particles is observed. The kinematics
of this process allow a clean separation of the signal process from scattering
off residual gas in the tube, and also a direct measurement of Mchi.


title:
Spitzer IRAC and MIPS Imaging of Clusters and Outflows in 9 High-mass
  Star Forming Regions

abstract:
  We present Spitzer Space Telescope IRAC and MIPS observations toward a sample
of nine high-mass star forming regions at a distance of around 2 kpc. Based on
IRAC and MIPS 24 $\mu$m photometric results and 2MASS JHKs data, we carry out a
census of young stellar objects (YSOs) in a 5' by 5' field toward each region.
Toward seven out of the nine regions, we detect parsec sized clusters with
around 20 YSOs surrounded by a more extended and sparse distribution of young
stars and protostars. For the other two regions, IRAS 20126+4104 and IRAS
22172+5549, the former has the lowest number of YSOs in the sample and shows no
obvious cluster, and the latter appears to be part of a larger, potentially
more evolved cluster. The deep IRAC imaging reveals at least twelve outflows in
eight out of the nine regions, with nine outflows prominent in the 4.5 $\mu$m
band most probably attributed to shocked H$_2$ emission, two outflows dominated
by scattered light in the 3.6 and 4.5 $\mu$m bands, and one outflow standing
out from its hydrocarbon emission in the 8.0 $\mu$m band. In comparison with
previous ground-based observations, our IRAC observations reveal new outflow
structures in five regions. The dramatically different morphologies of detected
outflows can be tentatively interpreted in terms of possible evolution of
massive outflows. The driving sources of these outflows are deeply embedded in
dense dusty cores revealed by previous millimeter interferometric observations.
We detect infrared counterparts of these dusty cores in the IRAC or MIPS 24
$\mu$m bands. Reflection nebulae dominated by the emission from UV heated
hydrocarbons in the 8 $\mu$m band can be found in most regions and they may
imply the presence of young B stars.


title:
Two-Photon Exchange Contribution to Proton Form Factors in Time-Like
  region

abstract:
  We estimate two-photon exchange contribution to the process $e^+ +e^- \to p +
\bar{p}$. The two-photon exchange corrections to double spin polarization
observables and form factors in the time-like region are calculated. The
corrections are found to be small in magnitude, but with a strong angular
dependence at fixed momentum transfer. These two features are the same as those
in the space-like region. In the view of experiment, the double spin
polarization observable $P_z$ deserves to be considered.


title: Pell's equation without irrational numbers

abstract:
  We solve Pell's equation in a simple way without continued fractions or
irrational numbers, and relate the algorithm to the Stern Brocot tree.


title: The q-WZ Method for Infinite Series

abstract:
  Motivated by the telescoping proofs of two identities of Andrews and Warnaar,
we find that infinite q-shifted factorials can be incorporated into the
implementation of the q-Zeilberger algorithm in the approach of Chen, Hou and
Mu to prove nonterminating basic hypergeometric series identities. This
observation enables us to extend the q-WZ method to identities on infinite
series. As examples, we will give the q-WZ pairs for some classical identities
such as the q-Gauss sum, the $_6\phi_5$ sum, Ramanujan's $_1\psi_1$ sum and
Bailey's $_6\psi_6$ sum.


title:
Improving SUSY Spectrum Determinations at the LHC with Wedgebox
  Technique

abstract:
  The LHC has the potential not only to discover supersymmetry (SUSY), but also
to permit fairly precise measurements of at least a portion of the sparticle
spectrum. Proposed mass reconstruction methods rely upon either inverting
invariant mass endpoint expressions or upon solving systems of mass-shell
equations. These methodologies suffer from the weakness that one certain
specific sparticle decay chain is assumed to account for all the events in the
sample. Taking two examples of techniques utilizing mass-shell equations, it is
found that also applying the wedgebox technique allows for the isolation of a
purer event sample, thus avoiding errors, possibly catastrophic, due to
mistaken assumptions about the decay chains involved and simultaneously
improving accuracy. What is innovative is using endpoint measurements (via the
wedgebox technique) to obtain a more homogeneous, well-understood sample set
rather than just using said endpoints to constrain the values of the masses
(here found by the mass-shell technique). The fusion of different established
techniques in this manner represents a highly profitable option for LHC
experimentalists who will soon have data to analyze.


title: Congruence Subgroups and Generalized Frobenius-Schur Indicators

abstract:
  We introduce generalized Frobenius-Schur indicators for pivotal categories.
In a spherical fusion category C, an equivariant indicator of an object in C is
defined as a functional on the Grothendieck algebra of the quantum double Z(C)
via generalized Frobenius-Schur indicators. The set of all equivariant
indicators admits a natural action of the modular group. Using the properties
of equivariant indicators, we prove a congruence subgroup theorem for modular
categories. As a consequence, all modular representations of a modular category
have finite images, and they satisfy a conjecture of Eholzer. In addition, we
obtain two formulae for the generalized indicators, one of them a
generalization of Bantay's second indicator formula for a rational conformal
field theory. This formula implies a conjecture of Pradisi-Sagnotti-Stanev, as
well as a conjecture of Borisov-Halpern-Schweigert.


title:
Surface-peaked medium effects in the interaction of nucleons with finite
  nuclei

abstract:
  We investigate the asymptotic separation of the optical model potential for
nucleon-nucleus scattering in momentum space, where the potential is split into
a medium-independent term and another depending exclusively on the gradient of
the density-dependent g matrix. This decomposition confines the medium
sensitivity of the nucleon-nucleus coupling to the surface of the nucleus. We
examine this feature in the context of proton-nucleus scattering at beam
energies between 30 and 100 MeV and find that the pn coupling accounts for most
of this sensitivity. Additionally, based on this general structure of the
optical potential we are able to treat both, the medium dependence of the
effective interaction and the full mixed density as described by
single-particle shell models. The calculated scattering observables agree
within 10% with those obtained by Arellano, Brieva and Love in their
momentum-space g-folding approach.


title: Neuberg cubics over finite fields

abstract:
  The framework of universal geometry allows us to consider metrical properties
of affine views of elliptic curves, even over finite fields. We show how the
Neuberg cubic of triangle geometry extends to the finite field situation and
provides interesting potential invariants for elliptic curves, focussing on an
explicit example over $\mathbb{F}_{23}$. We also prove that tangent conics for
a Weierstrass cubic are identical or disjoint.


title: Effective Action and Schwinger Pair Production in Scalar QED

abstract:
  Some astrophysical objects are supposed to have very strong electromagnetic
fields above the critical strength. Quantum fluctuations due to strong
electromagnetic fields modify the Maxwell theory and particularly electric
fields make the vacuum unstable against pair production of charged particles.
We study the strong field effect such as the effective action and the Schwinger
pair production in scalar QED.


title: The sum-product phenomenon in arbitrary rings

abstract:
  The \emph{sum-product phenomenon} predicts that a finite set $A$ in a ring
$R$ should have either a large sumset $A+A$ or large product set $A \cdot A$
unless it is in some sense "close" to a finite subring of $R$. This phenomenon
has been analysed intensively for various specific rings, notably the reals
$\R$ and cyclic groups $\Z/q\Z$. In this paper we consider the problem in
arbitrary rings $R$, which need not be commutative or contain a multiplicative
identity. We obtain rigorous formulations of the sum-product phenomenon in such
rings in the case when $A$ encounters few zero-divisors of $R$. As applications
we recover (and generalise) several sum-product theorems already in the
literature.


title: Constraining New Physics from D0-anti-D0 mixing

abstract:
  I review constraints on possible New Physics interactions from D0-anti-D0
mixing measurements. I consider the most general low energy effective
Hamiltonian and include leading order QCD running of effective operators. I
discuss constraints from an extensive list of popular New Physics models, each
of which could be discovered at the LHC, that can generate these operators. In
most of the scenarios, strong constraints that surpass those from other search
techniques could be placed on the allowed parameter space using the existent
evidence for observation of D-meson mixing.


title:
Magnetic ordering and quantum statistical effects in strongly repulsive
  Fermi-Fermi and Bose-Fermi mixtures

abstract:
  We investigate magnetic properties and statistical effects in 1D strongly
repulsive two-component fermions and in a 1D mixture of strongly repulsive
polarized fermions and bosons. Universality in the characteristics of phase
transitions, magnetization and susceptibility in the presence of an external
magnetic field $H$ are analyzed from the exact thermodynamic Bethe ansatz
solution. We show explicitly that polarized fermions with a repulsive
interaction have antiferromagnetic behavior at zero temperature. A universality
class of linear field-dependent magnetization persists for weak and finite
strong interaction. The system is fully polarized when the external field
exceeds the critical value $H^F_c\approx \frac{8}{\gamma}E_F$, where $E_F$ is
the Fermi energy and $\gamma$ is the dimensionless interaction strength. In
contrast, the mixture of polarized fermions and bosons in an external field
exhibits square-root field-dependent magnetization in the vicinities of H=0 and
the critical value $H=H^M_c\approx \frac{16}{\gamma}E_F$. We find that a pure
boson phase occurs in the absence of the external field, fully-polarized
fermions and bosons coexist for $0<H<H^M_c$, and a fully-polarized fermion
phase occurs for $H\ge H_c^M$. This phase diagram for the Bose-Fermi mixture is
reminiscent of weakly attractive fermions with population imbalance, where the
interacting fermions with opposite spins form singlet pairs.


title: Sequence length bounds for resolving a deep phylogenetic divergence

abstract:
  In evolutionary biology, genetic sequences carry with them a trace of the
underlying tree that describes their evolution from a common ancestral
sequence. The question of how many sequence sites are required to recover this
evolutionary relationship accurately depends on the model of sequence
evolution, the substitution rate, divergence times and the method used to infer
phylogenetic history. A particularly challenging problem for phylogenetic
methods arises when a rapid divergence event occurred in the distant past. We
analyse an idealised form of this problem in which the terminal edges of a
symmetric four--taxon tree are some factor ($p$) times the length of the
interior edge. We determine an order $p^2$ lower bound on the growth rate for
the sequence length required to resolve the tree (independent of any particular
branch length). We also show that this rate of sequence length growth can be
achieved by existing methods (including the simple `maximum parsimony' method),
and compare these order $p^2$ bounds with an order $p$ growth rate for a model
that describes low-homoplasy evolution. In the final section, we provide a
generic bound on the sequence length requirement for a more general class of
Markov processes.


title: Pseudo-Finsleroid spatial-anisotropic relativistic space

abstract:
  The pseudo-Finsleroid relativistic metric was constructed upon assuming that
the involved vector field $b_i$ is time-like. In the present paper it is shown
that the metric admits just the alternative counterpart in which the field is
space-like. The entailed pseudo-Finsleroid-spatial framework is systematically
described. We face on various remarkable properties, including the constant
curvature of the associated indicatrix, the explicit Hamiltonian function,
transparent presentations for the angle and scalar product. The spray
coefficients are found to be of a rather simple structure. The Berwald case is
attractively realized. Interesting conformal properties are stemming. {\bf
Keywords:} Finsler metrics, relativistic spaces, spray coefficients.


title:
Weak Measurement of Qubit Oscillations with Strong Response Detectors:
  Violation of the Fundamental Bound Imposed on Linear Detectors

abstract:
  We investigate the continuous weak measurement of a solid-state qubit by
single electron transistors in nonlinear response regime. It is found that the
signal-to-noise ratio can violate the universal upper bound imposed quantum
mechanically to any linear response detectors. We understand the violation by
means of the cross-correlation of the detector currents.


title: Central limit theorems for eigenvalues in a spiked population model

abstract:
  In a spiked population model, the population covariance matrix has all its
eigenvalues equal to units except for a few fixed eigenvalues (spikes). This
model is proposed by Johnstone to cope with empirical findings on various data
sets. The question is to quantify the effect of the perturbation caused by the
spike eigenvalues. A recent work by Baik and Silverstein establishes the almost
sure limits of the extreme sample eigenvalues associated to the spike
eigenvalues when the population and the sample sizes become large. This paper
establishes the limiting distributions of these extreme sample eigenvalues. As
another important result of the paper, we provide a central limit theorem on
random sesquilinear forms.


title:
Band Jahn-Teller Instability and Formation of Valence Bond Solid in a
  Mixed-Valent Spinel Oxide LiRh2O4

abstract:
  We have synthesized a new spinel oxide LiRh2O4 with a mixed-valent
configuration of Rh3+ and Rh4+. At room temperature it is a paramagnetic metal,
but on cooling, a metal-insulator transition occurs and a valence bond solid
state is formed below 170 K. We argue that the formation of valence bond solid
is promoted by a band Jahn-Teller transition at 230 K and the resultant
confinement of t2g holes within the xy band. The band Jahn-Teller instability
is also responsible for the observed enhanced thermoelectric power in the
orbital disordered phase above 230 K.


title: Brane cosmology, Weyl fluid, and density perturbations

abstract:
  We develop a technique to study relativistic perturbations in the generalised
brane cosmological scenario, which is a generalisation of the multi-fluid
cosmological perturbations to brane cosmology. The novelty of the technique
lies in the inclusion of a radiative bulk which is responsible for bulk-brane
energy exchange, and in turn, modifies the standard perturbative analysis to a
great extent. The analysis involves a geometric fluid -- called the Weyl fluid
-- whose nature and role have been studied extensively both for the empty bulk
and the radiative bulk scenario. Subsequently, we find that this Weyl fluid can
be a possible geometric candidate for dark matter in this generalised brane
cosmological framework.


title: Origin of large thermopower in LiRh$_2$O$_4$

abstract:
  Motivated by the newly synthesized mixed-valent spinel LiRh$_2$O$_4$ for
which a large thermopower is observed in the metallic cubic phase above 230K
[Okamoto {\it et al.} (arXiv:0806.2504)], we calculate the Seebeck coefficient
by the combination of local density approximation and dynamical mean field
theory (LDA+DMFT). The experimental values are well reproduced not only by
LDA+DMFT but also by the less involved Boltzmann equation approach. A careful
analysis of the latter shows unexpectedly that the origin of the large
thermopower shares a common root with a very different oxide: Na$_x$CoO$_2$. We
also discuss how it is possible to further increase the powerfactor of
LiRh$_2$O$_4$ through doping, which makes the material even more promoising for
technological applications.


title: Bouncing Braneworld with Born-Infeld and Gauss-Bonnet

abstract:
  We show the existence of some bouncing cosmological solutions in the
braneworld scenario. More specifically, we consider a dynamical three-brane in
the background of Born-Infeld and electrically charged Gauss-Bonnet black hole.
We find that, in certain range of parameter space, the brane universe, at least
classically, never shrinks to a zero size, resulting in a singularity-free
cosmology within the classical domain.


title: Gauss-Bonnet Term on Vacuum Decay

abstract:
  We study the effect of the Gauss-Bonnet term on vacuum decay process in the
Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling
with the real scalar field, which appears in the low energy effective action of
string theories. We calculate numerically the instanton solution, which
describes the process of vacuum decay, and obtain the critical size of bubble.
We find that the Gauss-Bonnet term has a nontrivial effect on the false vacuum
decay, depending on the Gauss-Bonnet coefficient.


title:
Proposition of a full deterministic medium access method for wireless
  network in a robotic application

abstract:
  Today, many network applications require shorter react time. Robotic field is
an excellent example of these needs: robot react time has a direct effect on
its task's complexity. Here, we propose a full deterministic medium access
method for a wireless robotic application. This contribution is based on some
low-power wireless personal area networks, like ZigBee standard. Indeed, ZigBee
has identified limits with Quality of Service due to non-determinist medium
access and probable collisions during medium reservation requests. In this
paper, two major improvements are proposed: an efficient polling of the star
nodes and a temporal deterministic distribution of peer-to-peer messages. This
new MAC protocol with no collision offers some QoS faculties.


title: What can we learn from $B\to a_1(1260)(b_1(1235))\pi(K)$ decays?

abstract:
  We investigate the $B\to a_1(1260)(b_1(1235))\pi(K)$ decays under the
factorization scheme and find many discrepancies between theoretical
predictions and the experimental data. In the tree dominated processes, large
contributions from color-suppressed tree diagrams are required in order to
accommodate with the large decay rates of $B^-\to a_1^0\pi^-$ and $B^-\to
a_1^-\pi^0$. For $\bar B^0\to (a_1^+, b_1^+)K^-$ decays which are both induced
by $b\to s$ transition, theoretical predictions on their decay rates are larger
than the data by a factor of 2.8 and 5.5, respectively. Large electro-weak
penguins or some new mechanism are expected to explain the branching ratios of
$B^-\to b_1^0K^-$ and $B^-\to a_1^-\bar K^0$. The
soft-collinear-effective-theory has the potential to explain large decay rates
of $B^-\to a_1^0\pi^-$ and $B^-\to a_1^-\pi^0$ via a large hard-scattering form
factor $\zeta_J^{B\to a_1}$. We will also show that, with proper charming
penguins, predictions on the branching ratios of $\bar B^0\to (a_1^+,
b_1^+)K^-$ can also be consistent with the data.


title:
How does "Which Way" Detector affect Fano Effect in Mesoscopic Transport
  --"Phonon-Fano" Or Not

abstract:
  We investigate the Fano interference in the presence of a "which way"
detector, i.e., a local electron-phonon coupler, in the context of mesoscopic
transport. Special attention is paid to study whether the phonon sidebands in
the differential conductance spectra exhibit the typical lineshape of the Fano
interference. When using a double-dot model we obtain two seemly contradictory
results by slightly different approaches: The Markovian approach leads to {\it
absolutely no} Fano interference at the phonon sidebands, while the
Non-Markovian approach results in {\it finite} Fano interference at the phonon
sidebands. On the other hand, by using the usual Aharonov-Bohm (AB)-ring model,
i.e., only one dot is embedded into one arm of an AB-ring, only the
Non-Markovian results are recovered. We explain these contradictory results and
make a comparison between the double-dot model and the usual AB-ring model at
length. Moreover, we also point out the essential difference between the
manifestation of the "which way" effect in mesoscopic double-slit experiments
and its optical counterpart.


title:
Quenched law of large numbers for branching Brownian motion in a random
  medium

abstract:
  We study a spatial branching model, where the underlying motion is
$d$-dimensional ($d\ge1$) Brownian motion and the branching rate is affected by
a random collection of reproduction suppressing sets dubbed mild obstacles. The
main result of this paper is the quenched law of large numbers for the
population for all $d\ge1$. We also show that the branching Brownian motion
with mild obstacles spreads less quickly than ordinary branching Brownian
motion by giving an upper estimate on its speed. When the underlying motion is
an arbitrary diffusion process, we obtain a dichotomy for the quenched local
growth that is independent of the Poissonian intensity. More general offspring
distributions (beyond the dyadic one considered in the main theorems) as well
as mild obstacle models for superprocesses are also discussed.


title:
The Perfect Binary One-Error-Correcting Codes of Length 15: Part
  I--Classification

abstract:
  A complete classification of the perfect binary one-error-correcting codes of
length 15 as well as their extensions of length 16 is presented. There are 5983
such inequivalent perfect codes and 2165 extended perfect codes. Efficient
generation of these codes relies on the recent classification of Steiner
quadruple systems of order 16. Utilizing a result of Blackmore, the optimal
binary one-error-correcting codes of length 14 and the (15, 1024, 4) codes are
also classified; there are 38408 and 5983 such codes, respectively.


title: Geometric torsions and an Atiyah-style topological field theory

abstract:
  The construction of invariants of three-dimensional manifolds with a
triangulated boundary, proposed earlier by the author for the case when the
boundary consists of not more than one connected component, is generalized to
any number of components. These invariants are based on the torsion of acyclic
complexes of geometric origin. The relevant tool for studying our invariants
turns out to be F.A. Berezin's calculus of anti-commuting variables; in
particular, they are used in the formulation of the main theorem of the paper,
concerning the composition of invariants under a gluing of manifolds. We show
that the theory obeys a natural modification of M. Atiyah's axioms for
anti-commuting variables.


title:
The quantum theory of the free Maxwell field on the de Sitter expanding
  universe

abstract:
  The theory of the free Maxwell field in two moving frames on the de Sitter
spacetime is investigated pointing out that the conserved momentum and energy
operators do not commute to each other. This leads us to consider new plane
waves solutions of the Maxwell equation which are eigenfunctions of the energy
operator. Such particular solutions complete the theory in which only the
solutions of given momentum were considered so far. The energy eigenfunctions
can be obtained thanks to our new time-evolution picture proposed previously
for the scalar and Dirac fields. Considering both these types of modes, it is
shown that the second quantization of the free electromagnetic potential in the
Coulomb gauge can be done in a canonical manner as in special relativity. The
principal conserved one-particle operators associated to Killing vectors are
derived, concentrating on the energy, momentum and total angular momentum
operators.


title:
Dynamics of Bloch vectors and the channel capacity of a non identical
  charged qubit pair

abstract:
  We have considered a system of two superconducting charge qubits capacitively
coupled to a microwave resonator. The dynamics of the Bloch vectors are
investigated for different regimes. By means of the Bloch vectors and cross
dyadic we quantify the degree of entanglement contained in the generated
entangled state. We consider different values of the system parameters to
discuss the dynamics of the channel capacity between the qubits. We show that
there is an important role played by initial state settings, coupling constant
and the mean photon number on generating entangled state with high degree of
entanglement and high capacity.


title: The computability path ordering: the end of a quest

abstract:
  In this paper, we first briefly survey automated termination proof methods
for higher-order calculi. We then concentrate on the higher-order recursive
path ordering, for which we provide an improved definition, the Computability
Path Ordering. This new definition appears indeed to capture the essence of
computability arguments \`a la Tait and Girard, therefore explaining the name
of the improved ordering.


title: Homogenization of a singular random one-dimensional PDE

abstract:
  This paper deals with the homogenization problem for a one-dimensional
parabolic PDE with random stationary mixing coefficients in the presence of a
large zero order term. We show that under a proper choice of the scaling factor
for the said zero order terms, the family of solutions of the studied problem
converges in law, and describe the limit process. It should be noted that the
limit dynamics remain random.


title:
The fraction of Bose-Einstein condensed triplons in TlCuCl3 from
  magnetization M(T,H)-data

abstract:
  In this study we calculate the fraction of condensed magnetic quasiparticles
of TlCuCl3 from magnetization M(T,H)-data. It is independent of the direction
of the magnetic field and slightly decreases with increasing magnetic field.


title:
Bundles of C*-categories, II: C*-dynamical systems and Dixmier-Douady
  invariants

abstract:
  We introduce a cohomological invariant arising from a class in nonabelian
cohomology. This invariant generalizes the Dixmier-Douady class and encodes the
obstruction to a C*-algebra bundle being the fixed-point algebra of a gauge
action. As an application, the duality breaking for group bundles vs. tensor
C*-categories with non-simple unit is discussed in the setting of
Nistor-Troitsky gauge-equivariant K-theory: there is a map assigning a
nonabelian gerbe to a tensor category, and "triviality" of the gerbe is
equivalent to the existence of a dual group bundle. At the C*-algebraic level,
this corresponds to studying C*-algebra bundles with fibre a fixed-point
algebra of the Cuntz algebra and in this case our invariant describes the
obstruction to finding an embedding into the Cuntz-Pimsner algebra of a vector
bundle.


title: Big rip avoidance via black holes production

abstract:
  We consider a cosmological scenario in which the expansion of the Universe is
dominated by phantom dark energy and black holes which condense out of the
latter component. The mass of black holes decreases via Hawking evaporation and
by accretion of phantom fluid but new black holes arise continuously whence the
overall evolution can be rather complex. We study the corresponding dynamical
system to unravel this evolution and single out scenarios where the big rip
singularity does not occur.


title: Supersymmetry Searches at the Tevatron

abstract:
  We present the current status of searches for supersymmetry performed at the
Tevatron accelerator at Fermilab by the CDF and D0 collaborations using
luminosity of up to 2.1 fb-1. We focus on searches for charginos, neutralinos,
squarks, gluinos and sneutrinos in several supersymmetric scenarios. No
supersymmetric signal is detected and limits on the masses and production cross
sections for the supersymmetric particles are set.


title: Electrostatic extraction of cold molecules from a cryogenic reservoir

abstract:
  We present a method which delivers a continuous, high-density beam of slow
and internally cold polar molecules. In our source, warm molecules are first
cooled by collisions with a cryogenic helium buffer gas. Cold molecules are
then extracted by means of an electrostatic quadrupole guide. For ND$_3$ the
source produces fluxes up to $(7 \pm ^{7}_{4}) \times 10^{10}$ molecules/s with
peak densities up to $(1.0 \pm ^{1.0}_{0.6}) \times 10^9$ molecules/cm$^3$. For
H$_2$CO the population of rovibrational states is monitored by depletion
spectroscopy, resulting in single-state populations up to $(82 \pm 10)%$.


title: How Do Schr\"odinger's Cats Die?

abstract:
  Recent experiments with superconducting qubits are motivated by the goal of
fabricating a quantum computer, but at the same time they illuminate the more
fundamental aspects of quantum mechanics. In this paper we analyze the physics
of switching current measurements from the point of view of macroscopic quantum
mechanics.


title:
The quenched invariance principle for random walks in random
  environments admitting a bounded cycle representation

abstract:
  We derive a quenched invariance principle for random walks in random
environments whose transition probabilities are defined in terms of weighted
cycles of bounded length. To this end, we adapt the proof for random walks
among random conductances by Sidoravicius and Sznitman (Probab. Theory Related
Fields 129 (2004) 219--244) to the non-reversible setting.


title: The heavy-ion programme of the ALICE experiment at LHC

abstract:
  The ALICE experiment at LHC is mainly dedicated to heavy-ion physics. An
overview of its performances, some predictions related to its first
measurements and QGP observable measurements will be given.


title: Torelli theorem for the moduli spaces of pairs

abstract:
  Let X be a smooth projective curve of genus at least two over the complex
numbers. A pair (E,\phi) over X consists of an algebraic vector bundle E over X
and a holomorphic section \phi of E. There is a concept of stability for pairs
which depends on a real parameter \tau. Here we prove that the third cohomology
groups of the moduli spaces of \tau-stable pairs with fixed determinant and
rank at least two are polarised pure Hodge structures, and they are isomorphic
to H^1(X) with its natural polarisation (except in very few exceptional cases).
  This implies a Torelli theorem for such moduli spaces. We recover that the
third cohomology group of the moduli space of stable bundles of rank at least
two and fixed determinant is a polarised pure Hodge structure, which is
isomorphic to H^1(X). We also prove Torelli theorems for the corresponding
moduli spaces of pairs and bundles with non-fixed determinant.


title:
Structural and magnetic phase diagram of CeFeAsO1-xFx and its
  relationship to high-temperature superconductivity

abstract:
  We use neutron scattering to study the structural and magnetic phase
transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a
semimetal to a high-transition-temperature (high-Tc) superconductor through
Fluorine (F) doping x. In the undoped state, CeFeAsO develops a structural
lattice distortion followed by a stripe like commensurate antiferromagnetic
order with decreasing temperature. With increasing Fluorine doping, the
structural phase transition decreases gradually while the antiferromagnetic
order is suppressed before the appearance of superconductivity, resulting an
electronic phase diagram remarkably similar to that of the high-Tc copper
oxides. Comparison of the structural evolution of CeFeAsO1-xFx with other
Fe-based superconductors reveals that the effective electronic band width
decreases systematically for materials with higher Tc. The results suggest that
electron correlation effects are important for the mechanism of high-Tc
superconductivity in these Fe pnictides.


title:
Transformation of kinematical quantities from rotating into static
  coordinate system

abstract:
  In this article the problem for the using of uniformly rotating coordinate
system is considered. The correct relations between the kinematical quantities
characterizing the motion of a body relative to uniformly rotating system and
static coordinate system are obtained.


title:
SWIFT J1753.5-0127: a surprising optical/X-ray cross-correlation
  function

abstract:
  We have conducted optical and X-ray simultaneous observations of SWIFT
J1753.5-0127 with RXTE and ULTRACAM, while the system persisted in its
relatively bright low/hard state. In the cross-correlation function (CCF), we
find that the optical leads the X-rays by a few seconds with a broad negative
peak, and has a smaller positive peak at positive lags. This is markedly
different from what was seen for the similarly interesting system XTE
J1118+480, and the first time such a correlation function has been so clearly
measured. Furthermore, there appears to be a significant variation of the
correlation with X-ray energy. We suggest a physical scenario for its origin.


title:
Baryon Operators of Higher Twist in QCD and Nucleon Distribution
  Amplitudes

abstract:
  We develop a general theoretical framework for the description of
higher-twist baryon operators which makes maximal use of the conformal symmetry
of the QCD Lagrangian. The conformal operator basis is constructed for all
twists. The complete analysis of the one-loop renormalization of twist-4
operators is given. The evolution equation for three-quark operators of the
same chirality turns out to be completely integrable. The spectrum of anomalous
dimensions coincides in this case with the energy spectrum of the twist-4
subsector of the SU(2,2) Heisenberg spin chain. The results are applied to give
a general classification and calculate the scale dependence of subleading
twist-4 nucleon distribution amplitudes that are relevant for hard exclusive
reactions involving a helicity flip. In particular we find an all-order
expression (in conformal spin) for the contributions of geometric twist-3
operators to the (light-cone) twist-4 nucleon distribution amplitudes, which
are usually referred to as Wandzura-Wilczek terms.


title: A slitless spectroscopic survey for quasars near quasars

abstract:
  We present the results of the Quasars near Quasars (QNQ) survey, a CCD-based
slitless spectroscopic survey for faint V<22 quasars at 1.7<z<3.6 on 18
26.2'x33.5' fields centred on bright quasars at 2.76<z<4.69. In total 169
quasar candidates with emission lines were selected from the extracted
flux-calibrated spectra on the basis of well-defined automatic selection
criteria followed by visual inspection and verification. With follow-up
spectroscopy of 81 candidates that were likely to reside at z>1.7 we were able
to confirm 80 new quasars at 0.580<z<3.586 on 16 of our fields. 64 of the newly
discovered quasars are located at z>1.7. The overall high success rate implies
that most of the remaining 88 candidates are quasars as well, although the
majority of them likely resides at z<1.7 on the basis of the observed line
shapes and strengths. Due to the insufficient depth of the input source
catalogues needed for extraction of the slitless spectra our survey is not well
defined in terms of limiting magnitude for faint 2.5<z<3.6 quasars whose Lyman
alpha emission is detectable well beyond V=22, albeit at a continuum S/N<1.
While not useful for characterising the evolving space density of quasars, our
sample provides many new closely spaced quasar sightlines around intensely
studied quasars for further investigations on the three-dimensional
distribution of the intergalactic medium.


title:
Asymptotic Analysis of the Performance of LAS Algorithm for Large-MIMO
  Detection

abstract:
  In our recent work, we reported an exhaustive study on the simulated bit
error rate (BER) performance of a low-complexity likelihood ascent search (LAS)
algorithm for detection in large multiple-input multiple-output (MIMO) systems
with large number of antennas that achieve high spectral efficiencies. Though
the algorithm was shown to achieve increasingly closer to near
maximum-likelihood (ML) performance through simulations, no BER analysis was
reported. Here, we extend our work on LAS and report an asymptotic BER analysis
of the LAS algorithm in the large system limit, where $N_t,N_r \to \infty$ with
$N_t=N_r$, where $N_t$ and $N_r$ are the number of transmit and receive
antennas. We prove that the error performance of the LAS detector in V-BLAST
with 4-QAM in i.i.d. Rayleigh fading converges to that of the ML detector as
$N_t,N_r \to \infty$.


title:
Nanostructure design for surface-enhanced Raman spectroscopy - prospects
  and limits

abstract:
  Surface-enhanced Raman spectroscopy (SERS) allows single-molecule detection
due to the strong field localization occurring at sharp bends or kinks of the
metal-vacuum interface. An important question concerns the limits of the signal
enhancement that can be achieved via a judicious design of the surface. By
using a specific example of a technologically realizable nanopatterned surface,
we demonstrate that while very high enhancement factors (~10^12) can be found
for an ideal surface, these are unlikely to be achieved in laboratory samples,
because even a minute, inevitable rounding-off strongly suppresses the
enhancement, as well as shifts the optimal frequency. Our simulations indicate
that the geometric enhancement factors are unlikely to exceed ~10^8 for real
samples, and that it is necessary to consider the geometric uncertainty to
reliably predict the frequency for maximum enhancement.

categories: physics.optics cond-mat.other physics.chem-ph physics.comp-ph


title:
Propagation of compressional elastic waves through a 1-D medium with
  contact nonlinearities

abstract:
  Propagation of monochromatic elastic waves across cracks is investigated in
1D, both theoretically and numerically. Cracks are modeled by nonlinear jump
conditions. The mean dilatation of a single crack and the generation of
harmonics are estimated by a perturbation analysis, and computed by the
harmonic balance method. With a periodic and finite network of cracks, direct
numerical simulations are performed and compared with Bloch-Floquet's analysis.


title: Hard electroproduction of vector mesons

abstract:
  It is reported on a global analysis of hard vector-meson electroproduction
which is based on the handbag factorization. The generalized parton
distributions are constructed from their forward limits with the help of double
distributions and the partonic subprocesses are calculated within the modified
perturbative approach.


title:
Dynamical creation of entanglement versus disentanglement in a system of
  three - level atoms with vacuum - induced coherences

abstract:
  The dynamics of entanglement between three - level atoms coupled to the
common vacuum is investigated. We show that the collective effects such as
collective damping, dipole - dipole interaction and the cross coupling between
orthogonal dipoles, play a crucial role in the process of creation of
entanglement. In particular, the additional cross coupling enhances the
production of entanglement. For the specific initial states we find that the
effect of delayed sudden birth of entanglement, recently invented by Ficek and
Tanas [Phys. Rev. A 77, o54301(2008)] in the case of two - level atoms, can
also be observed in the system. When the initial state is entangled, the
process of spontaneous emission causes destruction of correlation and its
disentanglement. We show that the robustness of initial enatnglement against
the noise can be changed by local operations performed on the state.


title: A Pilot Survey for KX QSOs in the UKIDSS Ultra Deep Survey Field

abstract:
  We have undertaken a pilot survey for faint QSOs in the UKIDSS Ultra Deep
Survey Field using the KX selection technique. These observations exploit the
very deep near-infrared and optical imaging of this field from UKIRT and Subaru
to select candidate QSOs based on their VJK colours and morphologies. We
determined redshifts for 426 candidates using the AAOmega spectrograph on the
AAT in service time. We identify 17 QSOs (M_B<= -23) in this pilot survey at
z=1.57-3.29. We combine our sample with an X-ray selected sample of QSOs in the
same field (a large fraction of which also comply with our KX selection) to
constrain the surface density of QSOs with K<=20, deriving limits on the likely
surface density of 85-150/deg^2. We use the good image quality available from
our near-infrared imaging to detect a spatially extended component of the QSO
light which probably represents the host galaxies. We also use our sample to
investigate routes to improve the selection of KX QSOs at faint limits in the
face of the significant contamination by compact, foreground galaxies. The
brightest examples from our combined QSO sample will be used in conjunction
with a large VLT VIMOS spectroscopic survey of high redshift galaxies in this
region to study the structures inhabited by gas, galaxies and growing
super-massive black holes at high redshifts in the UKIDSS UDS.


title: Reducibility of quantum representations of mapping class groups

abstract:
  In this paper we provide a general condition for the reducibility of the
Reshetikhin-Turaev quantum representations of the mapping class groups. Namely,
for any modular tensor category with a special symmetric Frobenius algebra with
a non-trivial genus one partition function, we prove that the quantum
representations of all the mapping class groups built from the modular tensor
category are reducible. In particular for SU(N) we get reducibility for certain
levels and ranks. For the quantum SU(2) Reshetikhin-Turaev theory we construct
a decomposition for all even levels. We conjecture this decomposition is a
complete decomposition into irreducible representations for high enough levels.


title: The Trigger System of the CMS Experiment

abstract:
  We give an overview of the main features of the CMS trigger and data
acquisition (DAQ) system. Then, we illustrate the strategies and trigger
configurations (trigger tables) developed for the detector calibration and
physics program of the CMS experiment, at start-up of LHC operations, as well
as their possible evolution with increasing luminosity. Finally, we discuss the
expected CPU time performance of the trigger algorithms and the CPU
requirements for the event filter farm at start-up.


title: Quantum decoherence and gravitational waves

abstract:
  The quite different behaviors exhibited by microscopic and macroscopic
systems with respect to quantum interferences suggest the existence of a
borderline beyond which quantum systems loose their coherences and can be
described classically. Gravitational waves, generated within our galaxy or
during the cosmic expansion, constitute a universal environment susceptible to
lead to such a quantum decoherence mechanism. We assess this idea by studying
the quantum decoherence due to gravitational waves on typical microscopic and
macoscopic systems, namely an atom interferometer (HYPER) and the Earth-Moon
system. We show that quantum interferences remain unaffected in the former case
and that they disappear extremely rapidly in the latter case. We obtain the
relevant parameters which, besides the ratio of the system's mass to Planck
mass, characterize the loss of quantum coherences.


title:
Coherence versus reliability of stochastic oscillators with delayed
  feedback

abstract:
  For noisy self-sustained oscillators, both reliability, stability of a
response to a noisy driving, and coherence understood in the sense of constancy
of oscillation frequency belong to the main characteristics. Though the both
characteristics and techniques for controlling them received great attention of
researchers, owing to their importance for neurons, lasers, clocks, electric
generators, etc., these characteristics were previously considered separately.
In this paper, strong quantitative relation between coherence and reliability
is revealed for a limit cycle oscillator subject to a weak noisy driving and a
linear delayed feedback, a convectional control tool. Analytical findings are
verified and enriched with a numerical simulation for the Van der Pol-Duffing
oscillator.


title: On the Time-Modulation of the beta^+$-Decay Rate of H-like 140Pr58+ Ion

abstract:
  According to recent experimental data at GSI, the rates of the number of
daughter ions, produced by the nuclear K-shell electron capture (EC) decays of
the H-like ions 140Pr58+ and 142Pm60+, are modulated in time with periods
T_(EC) simeq 7 s and amplitudes a_(EC) simeq 0.20. We study a possible
time-dependence of the nuclear positron (beta^+) decay rate of the H-like
140Pr58+. We show that the time-dependence of the beta^+ decay rate of the
H-like 140Pr58+ ion as well as any H-like heavy ions cannot be observed. This
result can be used as a prediction for future analysis of the time-dependence
of the beta^+ decay rates of the H-like heavy ions 140Pr58+ and 142Pm60+ at GSI
for the test of the measuring method.


title:
Momentum-space analysis of multipartite entanglement at quantum phase
  transitions

abstract:
  We investigate entanglement properties at quantum phase transitions of an
integrable extended Hubbard model in the momentum space representation. Two
elementary subsystems are recognized: the single mode of an electron, and the
pair of modes (electrons coupled through the eta-pairing mechanism). We first
detect the two/multi-partite nature of each quantum phase transition by a
comparative study of the singularities of Von Neumann entropy and quantum
mutual information. We establish the existing relations between the
correlations in the momentum representation and those exhibited in the
complementary picture: the direct lattice representation. The presence of
multipartite entanglement is then investigated in detail through the Q-measure,
namely a generalization of the Meyer-Wallach measure of entanglement. Such a
measure becomes increasingly sensitive to correlations of a multipartite nature
increasing the size of the reduced density matrix. In momentum space, we
succeed in obtaining the latter for our system at arbitrary size and we relate
its behaviour to the nature of the various QPTs.


title:
Measuring parameters of AGN central engines with very high energy
  gamma-ray flares

abstract:
  We discuss a "compact source" model of very high energy (VHE) emission from
blazars in which the variability time is determined by the blazar central
engine. In this model electron or proton acceleration close to the supermassive
black hole is followed by the development of electromagnetic cascade in a
radiatively inefficient accretion flow. Assuming such a model for the TeV
blazar PKS 2155-304, we show that the variability properties of the TeV
gamma-ray signal observed during a bright flare from this source, such as the
minimal variability time scale and the recurrence period of the sub-flares,
constrain the mass and the angular momentum of the supermassive black hole.


title: Approximate Hermite quasi-interpolation

abstract:
  In this paper we derive approximate quasi-interpolants when the values of a
function $u$ and of some of its derivatives are prescribed at the points of a
uniform grid. As a byproduct of these formulas we obtain very simple
approximants which provide high order approximations for solutions to elliptic
differential equations with constant coefficients.


title: Subelliptic Li-Yau estimates on three dimensional model spaces

abstract:
  We describe three elementary models in three dimensional subelliptic geometry
which correspond to the three models of the Riemannian geometry (spheres,
Euclidean spaces and Hyperbolic spaces) which are respectively the SU(2),
Heisenberg and SL(2) groups. On those models, we prove parabolic Li-Yau
inequalities on positive solutions of the heat equation. We use for that the
$\Gamma_{2}$ techniques that we adapt to those elementary model spaces. The
important feature developed here is that although the usual notion of Ricci
curvature is meaningless (or more precisely leads to bounds of the form
$-\infty$ for the Ricci curvature), we describe a parameter $\rho$ which plays
the same role as the lower bound on the Ricci curvature, and from which one
deduces the same kind of results as one does in Riemannian geometry, like heat
kernel upper bounds, Sobolev inequalities and diameter estimates.


title:
A Data-Parallel Algorithm to Reliably Solve Systems of Nonlinear
  Equations

abstract:
  Numerical methods based on interval arithmetic are efficient means to
reliably solve nonlinear systems of equations. Algorithm bc3revise is an
interval method that tightens variables' domains by enforcing a property called
box consistency. It has been successfully used on difficult problems whose
solving eluded traditional numerical methods. We present a new algorithm to
enforce box consistency that is simpler than bc3revise, faster, and easily data
parallelizable. A parallel implementation with Intel SSE2 SIMD instructions
shows that an increase in performance of up to an order of magnitude and more
is achievable.


title:
Prototyping and Performance Analysis of a QoS MAC Layer for Industrial
  Wireless Network

abstract:
  Today's industrial sensor networks require strong reliability and guarantees
on messages delivery. These needs are even more important in real time
applications like control/command, such as robotic wireless communications
where strong temporal constraints are critical. For these reasons, classical
random-based Medium Access Control (MAC) protocols present a non-null frame
collision probability. In this paper we present an original full deterministic
MAC-layer for industrial wireless network and its performance evaluation thanks
to the development of a material prototype.


title:
Proposition and validation of an original MAC layer with simultaneous
  medium accesses for low latency wireless control/command applications

abstract:
  Control/command processes require a transmission system with some
characteristics like high reliability, low latency and strong guarantees on
messages delivery. Concerning wire networks, field buses technologies like FIP
offer this kind of service (periodic tasks, real time constraints...).
Unfortunately, few wireless technologies can propose a communication system
which respects such constraints. Indeed, wireless transmissions must deal with
medium characteristics which make impossible the direct translation of
mechanisms used with wire networks. The purpose of this paper is to present an
original Medium Access Control (MAC) layer for a real time Low Power-Wireless
Personal Area Network (LP-WPAN). The proposed MAC-layer has been validated by
several complementary methods; in this paper, we focus on the specific
Simultaneous Guaranteed Time Slot (SGTS) part.


title: Dynamics of the solar tachocline II: the stratified case

abstract:
  We present a detailed numerical study of the Gough & McIntyre model for the
solar tachocline. This model explains the uniformity of the rotation profile
observed in the bulk of the radiative zone by the presence of a large-scale
primordial magnetic field confined below the tachocline by flows originating
from within the convection zone. We attribute the failure of previous numerical
attempts at reproducing even qualitatively Gough & McIntyre's idea to the use
of boundary conditions which inappropriately model the radiative--convective
interface. We emphasize the key role of flows downwelling from the convection
zone in confining the assumed internal field. We carefully select the range of
parameters used in the simulations to guarantee a faithful representation of
the hierarchy of expected lengthscales. We then present, for the first time, a
fully nonlinear and self-consistent numerical solution of the Gough & McIntyre
model which qualitatively satisfies the following set of observational
constraints: (i) the quenching of the large-scale differential rotation below
the tachocline - including in the polar regions - as seen by helioseismology
(ii) the confinement of the large-scale meridional flows to the uppermost
layers of the radiative zone as required by observed light element abundances
and suggested by helioseismic sound-speed data.


title: Complexity Measures from Interaction Structures

abstract:
  We evaluate new complexity measures on the symbolic dynamics of coupled tent
maps and cellular automata. These measures quantify complexity in terms of
$k$-th order statistical dependencies that cannot be reduced to interactions
between $k-1$ units. We demonstrate that these measures are able to identify
complex dynamical regimes.


title: Spinor Field Realizations of the half-integer $W_{2,s}$ Strings

abstract:
  The grading Becchi-Rouet-Stora-Tyutin (BRST) method gives a way to construct
the integer $W_{2,s}$ strings, where the BRST charge is written as
$Q_B=Q_0+Q_1$. Using this method, we reconstruct the nilpotent BRST charges
$Q_{0}$ for the integer $W_{2,s}$ strings and the half-integer $W_{2,s}$
strings. Then we construct the exact grading BRST charge with spinor fields and
give the new realizations of the half-integer $W_{2,s}$ strings for the cases
of $s=3/2$, 5/2, and 7/2.


title: Counterterm resummation for 2PI-approximation in constant background

abstract:
  Explicit counterterm construction is presented in a symmetry breaking
background for the 2PI effective action of the self-interacting one-component
scalar field including skeleton diagrams to O(\lambda^2). The applied strategy
is an extension of our treatment of the 2PI-Hartree approximation [G. Fejos, A.
Patkos and Zs. Szep, Nucl. Phys. A803 (2008) 135]. The procedure is also
applied to the O(N) model.


title:
Frequency of Correctness versus Average-Case Polynomial Time and
  Generalized Juntas

abstract:
  We prove that every distributional problem solvable in polynomial time on the
average with respect to the uniform distribution has a frequently
self-knowingly correct polynomial-time algorithm. We also study some features
of probability weight of correctness with respect to generalizations of
Procaccia and Rosenschein's junta distributions [PR07b].


title:
Trionic and quartetting phases in one-dimensional multicomponent
  ultracold fermions

abstract:
  We investigate the possible formation of a molecular condensate, which might
be, for instance, the analogue of the alpha condensate of nuclear physics, in
the context of multicomponent cold atoms fermionic systems. A simple
paradigmatic model of N-component fermions with contact interactions loaded
into a one-dimensional optical lattice is studied by means of low-energy and
numerical approaches. For attractive interaction, a quasi-long-range molecular
superfluid phase, formed from bound-states made of N fermions, emerges at low
density. We show that trionic and quartetting phases, respectively for N=3,4,
extend in a large domain of the phase diagram and are robust against small
symmetry-breaking perturbations.


title:
The influence of memory in deterministic walks in random media:
  analytical calculation within a mean field approximation

abstract:
  Consider a random medium consisting of points randomly distributed so that
there is no correlation among the distances. This is the random link model,
which is the high dimensionality limit (mean field approximation) for the
euclidean random point structure. In the random link model, at discrete time
steps, the walker moves to the nearest site, which has not been visited in the
last $\mu$ steps (memory), producing a deterministic partially self avoiding
walk (the tourist walk). We have obtained analitically the distribution of the
number $n$ of points explored by a walker with memory $\mu = 2$, as well as the
transient and period joint distribution. This result enables to explain the
abrupt change in the exploratory behavior between the cases $\mu = 1$
(memoryless, driven by extremal statistics) and $\mu = 2$ (with memory, driven
by combinatorial statistics). In the $\mu = 1$ case, the mean newly visited
points in the thermodynamic limit $(N \gg 1)$ is just $<n > = e = 2.72 ...$
while in the $\mu = 2$ case, the mean number $<n>$ of visited points is
proportional to $N^{1/2}$. Also, this result allows us to stabilish an
equivalence between the random link model with $\mu=2$ and random map
(uncorrelated back and forth distances) with $\mu=0$ and the drastic change
between the cases where the transient time is null compared to non-null
transient times.


title:
The contribution of fermionic seesaws to the anomalous magnetic moment
  of leptons

abstract:
  We calculate the contribution to the anomalous magnetic moment of leptons in
the type-I and type-III seesaw models. We show that, even if the scale of the
new physics is pushed down to the electroweak scale, this contribution is not
large enough to explain the measured discrepancy of the muon anomalous magnetic
moment.


title: On the Small Deviation Problem for Some Iterated Processes

abstract:
  We derive general results on the small deviation behavior for some classes of
iterated processes. This allows us, in particular, to calculate the rate of the
small deviations for $n$-iterated Brownian motions and, more generally, for the
iteration of $n$ fractional Brownian motions. We also give a new and correct
proof of some results in E. Nane, Laws of the iterated logarithm for
$\alpha$-time Brownian motion, Electron. J. Probab. 11 (2006), no. 18,
434--459.


title: Gravitational clustering: an overview

abstract:
  We discuss the differences and analogies of gravitational clustering in
finite and infinite systems. The process of collective, or violent, relaxation
leading to the formation of quasi-stationary states is one of the distinguished
features in the dynamics of self-gravitating systems. This occurs, in different
conditions, both in a finite than in an infinite system, the latter embedded in
a static or in an expanding background. We then discuss, by considering some
simple and paradigmatic examples, the problems related to the definition of a
mean-field approach to gravitational clustering, focusing on role of discrete
fluctuations. The effect of these fluctuations is a basic issue to be clarified
to establish the range of scales and times in which a collision-less
approximation may describe the evolution of a self-gravitating system and for
the theoretical modeling of the non-linear phase.


title:
On a class of optimal stopping problems for diffusions with
  discontinuous coefficients

abstract:
  In this paper, we introduce a modification of the free boundary problem
related to optimal stopping problems for diffusion processes. This modification
allows the application of this PDE method in cases where the usual regularity
assumptions on the coefficients and on the gain function are not satisfied. We
apply this method to the optimal stopping of integral functionals with
exponential discount of the form $E_x\int_0^{\tau}e^{-\lambda s}f(X_s) ds$,
$\lambda\ge0$ for one-dimensional diffusions $X$. We prove a general
verification theorem which justifies the modified version of the free boundary
problem. In the case of no drift and discount, the free boundary problem allows
to give a complete and explicit discussion of the stopping problem.


title: Kepler versus Akaike

abstract:
  I use the example of the Earth's orbit to illustrate the principle behind the
Akaike Information Criterion, and refute the misconception that the criterion,
by definition, discards more complex models in favour of simpler ones.


title: DMRG studies of critical SU(N) spin chains

abstract:
  The DMRG method is applied to integrable models of antiferromagnetic spin
chains for fundamental and higher representations of SU(2), SU(3), and SU(4).
  From the low energy spectrum and the entanglement entropy, we compute the
central charge and the primary field scaling dimensions. These parameters allow
us to identify uniquely the Wess-Zumino-Witten models capturing the low energy
sectors of the models we consider.


title: Non-Hermitian quantum mechanics in non-commutative space

abstract:
  We study non Hermitian quantum systems in noncommutative space as well as a
\cal{PT}-symmetric deformation of this space. Specifically, a
\mathcal{PT}-symmetric harmonic oscillator together with iC(x_1+x_2)
interaction is discussed in this space and solutions are obtained. It is shown
that in the \cal{PT} deformed noncommutative space the Hamiltonian may or may
not possess real eigenvalues depending on the choice of the noncommutative
parameters. However, it is shown that in standard noncommutative space, the
iC(x_1+x_2) interaction generates only real eigenvalues despite the fact that
the Hamiltonian is not \mathcal{PT}-symmetric. A complex interacting
anisotropic oscillator system has also been discussed.


title:
Dynamical electroweak symmetry breaking due to strong Yukawa
  interactions

abstract:
  We present a new mechanism for electroweak symmetry breaking (EWSB) based on
a strong Yukawa dynamics. We consider an SU(2)_L x U(1)_Y gauge invariant model
endowed with the usual Standard model fermion multiplets and with two massive
scalar doublets. We show that, unlike in the Standard model, EWSB is possible
even with vanishing vacuum expectation values of the scalars. Such EWSB is
achieved dynamically by means of the (presumably strong) Yukawa couplings and
manifests itself by the emergence of fermion and gauge boson masses and scalar
mass-splittings, which are expressed in a closed form in terms of the fermion
and scalar proper self-energies. The `would-be' Nambu--Goldstone bosons are
shown to be composites of both the fermions and the scalars. We demonstrate
that the simplest version of the model is compatible with basic experimental
constraints.


title:
Multiple frustration-induced plateaus in a magnetization process of the
  mixed spin-1/2 and spin-3/2 Ising-Heisenberg diamond chain

abstract:
  Magnetization process of the mixed spin-1/2 and spin-3/2 Ising-Heisenberg
diamond chain is examined by combining three exact analytical techniques: Kambe
projection method, decoration-iteration transformation and transfer-matrix
method. Multiple frustration-induced plateaus in a magnetization process of
this geometrically frustrated system are found provided that a relative ratio
between the antiferromagnetic Heisenberg- and Ising-type interactions exceeds
some particular value. By contrast, there is just a single magnetization
plateau if the frustrating Heisenberg interaction is sufficiently small
compared to the Ising one.


title: The Weil-Steinberg character of finite classical groups

abstract:
  We compute the irreducible constitutents of the product of the Weil character
and the Steinberg character in those finite classical groups for which a Weil
character is defined, namely the symplectic, unitary and general linear groups.
It turns out that this product is multiplicity free for the symplectic and
general unitary groups, but not for the general linear groups.
  As an application we show that the restriction of the Steinberg character of
such a group to the subgroup stabilizing a vector in the natural module is
multiplicity free. The proof of this result for the unitary groups uses an
observation of Brunat, published as an appendix to our paper.
  As our "Weil character" for the symplectic groups in even characteristic we
use the 2-modular Brauer character of the generalized spinor representation.
Its product with the Steinberg character is the Brauer character of a
projective module. We also determine its indecomposable direct summands.


title:
Spontaneous order in the highly frustrated spin-1/2 Ising-Heisenberg
  model on the triangulated Kagome lattice due to the Dzyaloshinskii-Moriya
  anisotropy

abstract:
  The spin-1/2 Ising-Heisenberg model on the triangulated Kagome
(triangles-in-triangles) lattice is exactly solved by establishing a precise
mapping correspondence to the simple spin-1/2 Ising model on Kagome lattice. It
is shown that the disordered spin liquid state, which otherwise occurs in the
ground state of this frustrated spin system on assumption that there is a
sufficiently strong antiferromagnetic intra-trimer interaction, is eliminated
from the ground state by arbitrary but non-zero Dzyaloshinskii-Moriya
anisotropy.


title: Electromagnetic Beams Overpass the Black Hole Horizon

abstract:
  We show that the electromagnetic excitations of the Kerr black hole have very
strong back reaction on metric. In particular, the electromagnetic excitations
aligned with the Kerr congruence form the light-like beams which overcome
horizon, forming the holes in it, which allows matter to escape interior. So,
there is no information lost inside the black hole. This effect is based
exclusively on the analyticity of the algebraically special solutions.


title:
Optimal investment and consumption in a Black--Scholes market with
  L\'evy-driven stochastic coefficients

abstract:
  In this paper, we investigate an optimal investment and consumption problem
for an investor who trades in a Black--Scholes financial market with stochastic
coefficients driven by a non-Gaussian Ornstein--Uhlenbeck process. We assume
that an agent makes investment and consumption decisions based on a power
utility function. By applying the usual separation method in the variables, we
are faced with the problem of solving a nonlinear (semilinear) first-order
partial integro-differential equation. A candidate solution is derived via the
Feynman--Kac representation. By using the properties of an operator defined in
a suitable function space, we prove uniqueness and smoothness of the solution.
Optimality is verified by applying a classical verification theorem.


title:
Validity of the relativistic impulse approximation for elastic
  proton-nucleus scattering at energies lower than 200 MeV

abstract:
  We present the first study to examine the validity of the relativistic
impulse approximation (RIA) for describing elastic proton-nucleus scattering at
incident laboratory kinetic energies lower than 200 MeV. For simplicity we
choose a $^{208}$Pb target, which is a spin-saturated spherical nucleus for
which reliable nuclear structure models exist. Microscopic scalar and vector
optical potentials are generated by folding invariant scalar and vector
scattering nucleon-nucleon (NN) amplitudes, based on our recently developed
relativistic meson-exchange model, with Lorentz scalar and vector densities
resulting from the accurately calibrated PK1 relativistic mean field model of
nuclear structure. It is seen that phenomenological Pauli blocking (PB) effects
and density-dependent corrections to $\sigma$N and $\omega$N meson-nucleon
coupling constants modify the RIA microscopic scalar and vector optical
potentials so as to provide a consistent and quantitative description of all
elastic scattering observables, namely total reaction cross sections,
differential cross sections, analyzing powers and spin rotation functions. In
particular, the effect of PB becomes more significant at energies lower than
200 MeV, whereas phenomenological density-dependent corrections to the NN
interaction {\it also} play an increasingly important role at energies lower
than 100 MeV.


title: Testing single-photon wave packets by Hong-Ou-Mandel interference

abstract:
  We discuss characterization of single-photon wave packets by measuring
Hong-Ou-Mandel interference with a weak coherent pulse. A complete multimode
calculation is presented and effects of multiphoton terms in the coherent field
as well as the impact of source and detection imperfections are discussed.


title: Pulsating White Dwarf Stars and Precision Asteroseismology

abstract:
  Galactic history is written in the white dwarf stars. Their surface
properties hint at interiors composed of matter under extreme conditions. In
the forty years since their discovery, pulsating white dwarf stars have moved
from side-show curiosities to center stage as important tools for unraveling
the deep mysteries of the Universe. Innovative observational techniques and
theoretical modeling tools have breathed life into precision asteroseismology.
We are just learning to use this powerful tool, confronting theoretical models
with observed frequencies and their time rate-of-change. With this tool, we
calibrate white dwarf cosmochronology; we explore equations of state; we
measure stellar masses, rotation rates, and nuclear reaction rates; we explore
the physics of interior crystallization; we study the structure of the
progenitors of Type Ia supernovae, and we test models of dark matter. The white
dwarf pulsations are at once the heartbeat of galactic history and a window
into unexplored and exotic physics.


title:
First stars and the extragalactic background light: How recent gamma-ray
  observations constrain the early universe

abstract:
  The formation of the first stars (Population III; PopIII) marks the end of
the dark ages of the universe, a subject of lively scientific debate. Not (yet)
accessible to direct observations, this early stage of the universe is mostly
studied via theoretical calculations and numerical simulations. An indirect
window is provided by integrated present day observables such as the metal
abundance or the diffuse extragalactic photon fields. We aim to derive
constraints on the properties of the PopIII and low metallicity Population II
(LM PopII) stars utilizing limits on the density of the extragalactic
background light (EBL), recently derived from very-high-energy (E > 100 GeV;
VHE) observations. A model calculation for the evolving EBL density produced by
PopIII/LM PopII stars is presented. The model utilizes stellar population
spectra (SPS) for zero and low metallicity stars and accounts for the changing
emission of an aging stellar population. Emission from the dense HII regions
surrounding the stars (nebula) is included. The resulting EBL density for
different scenarios (metallicity, star formation rate, initial mass function)
is compared to the limit on the EBL density. The potential for detecting a
cut-off in HE/VHE spectra is discussed. Assuming a maximum contribution from
PopIII/LM PopII stars to the EBL density of 5 nW m^-2 s-1 at 2 micrometer a
limit on the star formation rate (SFR) of the first stars of 0.3 to 3 M_solar
Mpc^-3 yr^-1 in the redshift range 7 - 14 is derived. The limit depends on the
assumed shape of the SFR and metallicity.


title: What will Gaia tell us about the Galactic disk?

abstract:
  Gaia will provide parallaxes and proper motions with accuracy ranging from 10
to 1000 microarcsecond on up to one billion stars. Most of these will be disk
stars: for an unreddened K giant at 6 kpc, it will measure the distance
accurate to 15% and the transverse velocity to an accuracy of about 1 km/s.
Gaia will observe tracers of Galactic structure across the whole HR diagram,
including Cepheids, RR Lyrae, white dwarfs, F dwarfs and HB stars. Onboard low
resolution spectrophotometry will permit -- in addition to a Teff estimate --
dwarf/giant discrimination, metallicity measurement and extinction
determination. For the first time, then, Gaia will provide us with a 3D
spatial/properties map and at least a 2D velocity map of these tracers (RVs
will be obtained too for brighter stars.) This will be a goldmine of
information from which to learn about the origin and evolution of the Galactic
disk. I briefly review the Gaia mission, and then show how the expected
astrometric accuracies translate into distance and velocity accuracies and
statistics. I examine the impact Gaia should have on a few scientific areas
relevant to the Galactic disk. I discuss how a better determination of the
spiral arm locations and pattern speed, plus a better reconstruction of the
Sun's orbit over the past billion years (from integration through the
Gaia-measured gravitational potential) will allow us to assess the possible
role of spiral arm crossings in ice ages and mass extinctions on the Earth.


title: Continuum elastic modeling of graphene resonators

abstract:
  Starting from an atomistic approach we have derived a hierarchy of
successively more simplified continuum elasticity descriptions for modeling the
mechanical properties of suspended graphene sheets. The descriptions are
validated by applying them to square graphene-based resonators with clamped
edges and studying numerically their mechanical responses. Both static and
dynamic responses are treated. We find that already for deflections of the
order of 0.5{\AA} a theory that correctly accounts for nonlinearities is
necessary and that for many purposes a set of coupled Duffing-type equations
may be used to accurately describe the dynamics of graphene membranes.


title:
Density dependence of spin relaxation in GaAs quantum well at room
  temperature

abstract:
  Carrier density dependence of electron spin relaxation in an intrinsic GaAs
quantum well is investigated at room temperature using time-resolved circularly
polarized pump-probe spectroscopy. It is revealed that the spin relaxation time
first increases with density in the relatively low density regime where the
linear D'yakonov-Perel' spin-orbit coupling terms are dominant, and then tends
to decrease when the density is large and the cubic D'yakonov-Perel' spin-orbit
coupling terms become important. These features are in good agreement with
theoritical predictions by L\"u {\em et al.} [Phys. Rev. B {\bf 73}, 125314
(2006)]. A fully microscopic calculation based on numerically solving the
kinetic spin Bloch equations with both the D'yakonov-Perel' and the
Bir-Aronov-Pikus mechanisms included, reproduces the density dependence of spin
relaxation very well.


title:
Probing thermal waves on the free surface of various media: Surface
  Fluctuation Specular Reflection Spectroscopy

abstract:
  Thermal motion gives rise to fluctuations in free surfaces; the propagation
of the thermally excited waves on such surfaces depends on the mechanical
properties of the medium. Their measurement can therefore provide information
on those properties. We have developed an optical tool to probe the thermally
excited waves on free surfaces: Surface Fluctuation Specular Reflection (SFSR)
spectroscopy. It consists in measuring the fluctuations in the position of a
laser beam, which is specularly reflected onto the free surface of a medium,
and is therefore sensitive to the roughness of that surface. We show how the
measured signal is related to the medium properties. We also present
measurements performed on Newtonian liquids as well as on a viscoelastic solid;
we show that, in all cases, there is a very good agreement between experimental
and computed spectra. SFSR thus applies to a broad range of materials. It
moreover offers a very good temporal resolution and should provide a useful
tool for dynamical measurements on complex fluids.


title: Structural trends in clusters of quadrupolar spheres

abstract:
  The influence of quadrupolar interactions on the structure of small clusters
is investigated by adding a point quadrupole of variable strength to the
Lennard-Jones potential. Competition arises between sheet-like arrangements of
the particles, favoured by the quadrupoles, and compact structures, favoured by
the isotropic Lennard-Jones attraction. Putative global potential energy minima
are obtained for clusters of up to 25 particles using the basin-hopping
algorithm. A number of structural motifs and growth sequences emerge, including
star-like structures, tubes, shells and sheets. The results are discussed in
the context of colloidal self-assembly.


title: A Local-Global Criterion for Dynamics on P^1

abstract:
  Let K be a number field or a function field, let F:P^1 --> P^1 be a rational
map of degree at least two defined over K, let P be a point in P^1(K) having
infinite F-orbit, and let Z be a finite subset of Z. We prove a local-global
criterion for the intersection of the F-orbit of P and the finite set Z. This
is a special case of a dynamical Brauer-Manin criterion suggested by Hsia and
Silverman.


title: A chain dictionary method for Word Sense Disambiguation and applications

abstract:
  A large class of unsupervised algorithms for Word Sense Disambiguation (WSD)
is that of dictionary-based methods. Various algorithms have as the root Lesk's
algorithm, which exploits the sense definitions in the dictionary directly. Our
approach uses the lexical base WordNet for a new algorithm originated in
Lesk's, namely "chain algorithm for disambiguation of all words", CHAD. We show
how translation from a language into another one and also text entailment
verification could be accomplished by this disambiguation.


title:
A unified framework for utility maximization problems: An Orlicz space
  approach

abstract:
  We consider a stochastic financial incomplete market where the price
processes are described by a vector-valued semimartingale that is possibly
nonlocally bounded. We face the classical problem of utility maximization from
terminal wealth, with utility functions that are finite-valued over
$(a,\infty)$, $a\in\lbrack-\infty,\infty)$, and satisfy weak regularity
assumptions. We adopt a class of trading strategies that allows for stochastic
integrals that are not necessarily bounded from below. The embedding of the
utility maximization problem in Orlicz spaces permits us to formulate the
problem in a unified way for both the cases $a\in\mathbb{R}$ and $a=-\infty$.
By duality methods, we prove the existence of solutions to the primal and dual
problems and show that a singular component in the pricing functionals may also
occur with utility functions finite on the entire real line.


title: Avoided crossings between bound states of ultracold Cesium dimers

abstract:
  We present an efficient new computational method for calculating the binding
energies of the bound states of ultracold alkali-metal dimers in the presence
of magnetic fields. The method is based on propagation of coupled differential
equations and does not use a basis set for the interatomic distance coordinate.
It is much more efficient than the previous method based on a radial basis set
and allows many more spin channels to be included. This is particularly
important in the vicinity of avoided crossings between bound states. We
characterize a number of different avoided crossings in Cs_2 and compare our
converged calculations with experimental results. Small but significant
discrepancies are observed in both crossing strengths and level positions,
especially for levels with l symmetry (rotational angular momentum L=8). The
discrepancies should allow the development of improved potential models in the
future.


title: Multiple Membranes from Gauged Supergravity

abstract:
  Starting from gauged N=8 supergravity in three dimensions we construct
actions for multiple membranes by taking the limit to global supersymmetry for
different choices of the embedding tensor. This provides a general framework
that reproduces many recent results on multiple membrane actions as well as
generalisations thereof. As examples we discuss conformal (non-conformal)
gaugings leading to multiple M2-branes (D2-branes) and massive deformations of
these systems.


title: From dark matter to MOND

abstract:
  MOND-- modified Newtonian dynamics-- may be viewed as an algorithm for
calculating the distribution of force in an astronomical object from the
observed distribution of baryonic matter. The fact that it works for galaxies
is quite problematic for Cold Dark Matter. Moreover, MOND explains or subsumes
systematic aspects of galaxy photometry and kinematics-- aspects that CDM does
not address or gets wrong. I will present evidence here in support of these
assertions and claim that this is effectively a falsification of dark matter
that is dynamically important on the scale of galaxies.


title: Connected subgroups of SO(2,n) acting irreducibly on $\R^{2,n}$

abstract:
  We classify all connected subgroups of SO(2,n) that act irreducibly on
$\R^{2,n}$. Apart from $SO_0(2,n)$ itself these are $U(1,n/2)$, $SU(1,n/2)$, if
$n$ even, $S^1\cdot SO(1,n/2)$ if $n$ even and $n\ge 2$, and $SO_0(1,2)$ for
$n=3$. Our proof is based on the Karpelevich Theorem and uses the
classification of totally geodesic submanifolds of complex hyperbolic space and
of the Lie ball. As an application we obtain a list of possible irreducible
holonomy groups of Lorentzian conformal structures, namely $SO_0(2,n)$,
SU(1,n), and $SO_0(1,2)$.