title: McShane's identity, using elliptic elements

abstract:
  We introduce a new method to establish McShane's Identity, based upon the
fact that elliptic elements of order two in the Fuchsian group uniformizing the
quotient of a fixed once-punctured hyperbolic torus act so as to exclude points
as being highest points of geodesics.


title:
Experimental Characterization of the static behaviour of
  microcatntilevers electrostatically actuated

abstract:
  This paper concerns the experimental validation of some mathematical models
previously developed by the authors, to predict the static behaviour of
microelectrostatic actuators, basically free-clamped microbeams. This layout is
currently used in RF-MEMS design operation or even in material testing at
microscale. The analysis investigates preliminarily the static behaviour of a
set of microcantilevers bending in-plane. This investigation is aimed to
distinguish the geometrical linear behaviour, exhibited under small
displacement assumption, from the geometrical nonlinearity, caused by large
deflection. The applied electromechanical force, which nonlinearly depends on
displacement, charge and voltage, is predicted by a coupled-field approach,
based on numerical methods and herewith experimentally validated, by means of a
Fogale Zoomsurf 3D. Model performance is evaluated on pull-in prediction and on
the curve displacement vs. voltage. In fact, FEM nonlinear solution performed
by a coupled-field approach, available on commercial codes, and by a FEM
non-incremental approach are compared with linear solution, for different
values of the design parameters.


title: Commuting holonomies and rigidity of holomorphic foliations

abstract:
  In this article we study deformations of a holomorphic foliation with a
generic non-rational first integral in the complex plane. We consider two
vanishing cycles in a regular fiber of the first integral with a non-zero self
intersection and with vanishing paths which intersect each other only at their
start points. It is proved that if the deformed holonomies of such vanishing
cycles commute then the deformed foliation has also a first integral. Our
result generalizes a similar result of Ilyashenko on the rigidity of
holomorphic foliations with a persistent center singularity. The main tools of
the proof are Picard-Lefschetz theory and the theory of iterated integrals for
such deformations.


title: Nanobiosensors based on individual olfactory receptors

abstract:
  In the SPOT-NOSED European project, nanoscale sensing elements bearing
olfactory receptors and grafted onto functionalized gold substrates are used as
odorant detectors to develop a new concept of nanobioelectronic nose, through
sensitive impedancemetric measurement of single receptor conformational change
upon ligand binding, with a better specificity and lower detection threshold
than traditional physical sensors.


title: Bridge configurations in piezoresistive two-axis accelerometers

abstract:
  In piezoresisitive two-axis accelerometers with two proof masses suspended by
cantilever beams, there are generally many ways to configure the Wheatstone
bridges. The configurations are different both with respect to functionality
and performance. The main distinction is between bridges that contain resistors
belonging to both proof masses, and the one bridge that doesn't. We compare the
different bridge configurations by analytical calculations of bridge
non-linearity, robustness towards manufacturing variations and electronic
noise. We consider accelerometers where the ratio between the sensitivity to
acceleration normal and parallel to the chip plane vary over a wide range. For
numerical examples we use representative values for p-type silicon. The
performance of the configuration with one bridge connected to each proof mass
is superior to those that combine resistors belonging to different proof
masses.


title: Online Sensor Testing through Superposition of Encoded Stimulus

abstract:
  Online monitoring remains an important requirement for a range of
microsystems. The solution based on the injection of an actuating test stimulus
into the bias structure of active devices holds great potential. This paper
presents an improved solution that aims to remove the measurand-induced signal
from the sensor output. It involves encoding the test stimulus and using a
covariance algorithm to reject the signal that does not contain the code. The
trade-off between the sine wave rejection ratio of the technique and the test
time response is studied and, in the case of a MEMS accelerometer, it is
demonstrated that the rejection is higher than 14dB for a test time of about
0.7s. Furthermore, the accuracy of the test signal can be evaluated to
guarantee the integrity of the online test output.


title: Modeling of T-Shaped Microcantilever Resonators

abstract:
  The extensive research and development of micromechanical resonators is
trying to allow the use of these devices for highly sensitive applications.
Microcantilevers are some of the simplest MEMS structure and had been proved to
be a good platform due to its excellent mechanical properties. A cantilever
working in dynamic mode, adjust its resonance frequency depending on changes in
both the spring constant (k) and mass (m) of the resonator. The aim of this
work was to model a cantilever structure to determine the optimal dimensions in
which the resonance frequency would be a function dominated by mass changes and
not stiffness changes. In order to validate the model a set of microcantilevers
were fabricated and characterized.


title:
Novel Bonding technologies for wafer-level transparent packaging of
  MOEMS

abstract:
  Depending on the type of Micro-Electro-Mechanical System (MEMS), packaging
costs are contributing up to 80% of the total device cost. Each MEMS device
category, its function and operational environment will individually dictate
the packaging requirement. Due to the lack of standardized testing procedures,
the reliability of those MEMS packages sometimes can only be proven by taking
into consideration its functionality over lifetime. Innovation with regards to
cost reduction and standardization in the field of packaging is therefore of
utmost importance to the speed of commercialisation of MEMS devices. Nowadays
heavily driven by consumer applications the MEMS device market is forecasted to
enjoy a compound annual growth rate (CAGR) above 13%, which is when compared to
the IC device market, an outstanding growth rate. Nevertheless this forecasted
value can drift upwards or downwards depending on the rate of innovation in the
field of packaging. MEMS devices typically require a specific fabrication
process where the device wafer is bonded to a second wafer which effectively
encapsulates the MEMS structure. This method leaves the device free to move
within a vacuum or an inert gas atmosphere.


title:
Design and Fabrication of the Suspended High-Q Spiral Inductors with
  X-Beams

abstract:
  In this paper, deep sub-micron CMOS process compatible high Q on chip spiral
inductors with air gap structure were designed and fabricated. In the design
the electromagnetic were used for electrical-characteristics and maximum
mechanical strength, respectively. The copper wires were capped with
electroless Ni plating to prevent the copper from oxidizing. A Si3N4/ SiO2
X-beam was designed to increase the mechanical strength of the inductor in air
gap. The enhancement of maximum mechanical strength of a spiral inductor with
X-beams is more than 4500 times. Among these structures, the measured maximum
quality factor (Q) of the suspending inductor and frequency at maximum Q are
improved from 5.2 and 1.6GHz of conventional spiral inductor to 7.3 and 2.1
GHz, respectively.


title: One MEMS Design Tool with Maximal Six Design Flows

abstract:
  This paper presents one MEMS design tool with total six design flows, which
makes it possible that the MEMS designers are able to choose the most suitable
design flow for their specific devices. The design tool is divided into three
levels and interconnected by six interfaces. The three levels are
lumped-element model based system level, finite element analysis based device
level and process level, which covers nearly all modeling and simulation
functions for MEMS design. The six interfaces are proposed to automatically
transmit the design data between every two levels, thus the maximal six design
flows could be realized. The interfaces take the netlist, solid model and
layout as the data inlet and outlet for the system, device and process level
respectively. The realization of these interfaces are presented and verified by
design examples, which also proves that the enough flexibility in the design
flow can really increase the design efficiency.


title: Studies of Polymer Deformation and Recovery in Hot Embossing

abstract:
  In large area micro hot embossing, the process temperature plays a critical
role to both the local fidelity of microstructure formation and global
uniformity. The significance of low temperature hot embossing is to improve
global flatness of embossed devices. This paper reports on experimental studies
of polymer deformation and relaxation in micro embossing when the process
temperatures are below or near its glass transition temperature (Tg). In this
investigation, an indentation system and a micro embosser were used to
investigate the relationship of microstructure formation versus process
temperature and load pressure. The depth of indentation was controlled and the
load force at a certain indentation depth was measured. Experiments were
carried out using 1 mm thick PMMA films with the process temperature ranging
from Tg-55 degrees C to Tg +20 degrees C. The embossed structures included a
single micro cavity and groups of micro cavity arrays. It was found that at
temperature of Tg-55 degrees C, elastic deformation dominated the formation of
microstructures and significant relaxation happened after embossing. From Tg-20
degrees C to Tg, plastic deformation dominated polymer deformation, and
permanent cavities could be formed on PMMA substrates without obvious
relaxation. However, the formation of protrusive structures as micro pillars
was not complete since there was little polymer flow. With an increase in
process temperature, microstructure could be formed under lower loading
pressure. Considering the fidelity of a single microstructure and global
flatness of embossed substrates, micro hot embossing at a low process
temperature, but with good fidelity, should be preferred.


title:
Evaluation of the thermal and hydraulic performances of a very thin
  sintered copper flat heat pipe for 3D microsystem packages

abstract:
  The reported research work presents numerical studies validated by
experimental results of a flat micro heat pipe with sintered copper wick
structure. The objectives of this project are to produce and demonstrate the
efficiency of the passive cooling technology (heat pipe) integrated in a very
thin electronic substrate that is a part of a multifunctional 3-D electronic
package. The enhanced technology is dedicated to the thermal management of high
dissipative microsystems having heat densities of more than 10W/cm2. Future
applications are envisaged in the avionics sector. In this research 2D
numerical hydraulic model has been developed to investigate the performance of
a very thin flat micro heat pipe with sintered copper wick structure, using
water as a refrigerant. Finite difference method has been used to develop the
model. The model has been used to determine the mass transfer and fluid flow in
order to evaluate the limits of heat transport capacity as functions of the
dimensions of the wick and the vapour space and for various copper spheres
radii. The results are presented in terms of liquid and vapour pressures within
the heat pipe. The simulated results are validated by experiments and proved
that the method can be further used to predict thermal performance of the heat
pipe and to optimise its design.


title: A survey of liquid crystalline oxadiazoles

abstract:
  We propose a survey of those oxadiazole compounds, which are mesogenic. We
will see that they can have bend-shaped molecules, a biaxial nematic phase, or
other interesting peculiarities in the nematic and smectic phase. With large
electric dipoles and luminescent properties, these materials are also very
appealing for technological applications.


title: Propagation of cosmic rays in the foam-like Universe

abstract:
  The model of a classical spacetime foam is considered, which consists of
static wormholes embedded in Minkowski spacetime. We examine the propagation of
particles in such a medium and demonstrate that a single thin ray undergoes a
specific damping in the density of particles depending on the traversed path
and the distribution of wormholes. The missing particles are scattered around
the ray. Wormholes was shown to form DM halos around point-like sources.
Therefore, the correlation predicted between the damping and the amount of DM
can be used to verify the topological nature of Dark Matter.


title: An entropic view of Pickands' theorem

abstract:
  It is shown that distributions arising in Renyi-Tsallis maximum entropy
setting are related to the Generalized Pareto Distributions (GPD) that are
widely used for modeling the tails of distributions. The relevance of such
modelization, as well as the ubiquity of GPD in practical situations follows
from Balkema-De Haan-Pickands theorem on the distribution of excesses (over a
high threshold). We provide an entropic view of this result, by showing that
the distribution of a suitably normalized excess variable converges to the
solution of a maximum Tsallis entropy, which is the GPD. This highlights the
relevance of the so-called Tsallis distributions in many applications as well
as some relevance to the use of the corresponding entropy.


title:
Estim\'ees des noyaux de Green et de la chaleur sur les espaces
  sym\'etriques

abstract:
  We obtain an off-diagonal upper bound for Green and heat kernel of Laplace
type operator on symmetric spaces.


title:
Multiple Stratonovich integral and Hu--Meyer formula for L\'{e}vy
  processes

abstract:
  In the framework of vector measures and the combinatorial approach to
stochastic multiple integral introduced by Rota and Wallstrom [Ann. Probab. 25
(1997) 1257--1283], we present an It\^{o} multiple integral and a Stratonovich
multiple integral with respect to a L\'{e}vy process with finite moments up to
a convenient order. In such a framework, the Stratonovich multiple integral is
an integral with respect to a product random measure whereas the It\^{o}
multiple integral corresponds to integrate with respect to a random measure
that gives zero mass to the diagonal sets. A general Hu--Meyer formula that
gives the relationship between both integrals is proved. As particular cases,
the classical Hu--Meyer formulas for the Brownian motion and for the Poisson
process are deduced. Furthermore, a pathwise interpretation for the multiple
integrals with respect to a subordinator is given.


title:
First principles calculation of spin-interactions and magnetic ground
  states of Cr trimers on Au(111)

abstract:
  We present calculations of the magnetic ground states of Cr trimers in
different geometries on top of a Au(111) surface. By using a least square fit
method based on a fully relativistic embedded-cluster Green's function method
first we determined the parameters of a classical vector-spin model consisting
of second and fourth order interactions. The newly developed method requires no
symmetry constraints, therefore, it is throughout applicable for small
nanoparticles of arbitrary geometry. The magnetic ground states were then found
by solving the Landau-Lifshitz-Gilbert equations. In all considered cases the
configurational energy of the Cr trimers is dominated by large
antiferromagnetic nearest neighbor interactions, whilst biquadratic
spin-interactions have the second largest contributions to the energy. We find
that an equilateral Cr trimer exhibits a frustrated 120$^\circ$ N\'eel type of
ground state with a small out-of-plane component of the magnetization and we
show that the Dzyaloshinsky-Moriya interactions determine the chirality of the
magnetic ground state. In cases of a linear chain and an isosceles trimer
collinear antiferromagnetic ground states are obtained with a magnetization
lying parallel to the surface.


title:
Open-Loop Control in Quantum Optics: Two-Level Atom in Modulated Optical
  Field

abstract:
  The methods of mathematical control theory are widely used in the modern
physics, but still they are less popular in quantum science. We will discuss
the aspects of control theory, which are the most useful in applications to the
real problems of quantum optics. We apply this technique to control the
behavior of the two-level quantum particles (atoms) in the modulated external
optical field in the frame of the so called "semi classical model", where
quantum two-level atomic system (all other levels are neglected) interacts with
classical electromagnetic field. In this paper we propose a simple model of
feedforward (open-loop) control for the quantum particle system, which is a
basement for further investigation of two-level quantum particle in the
external one-dimensional optical field.


title:
Dynamical systems with internal degrees of freedom in non-Euclidean
  spaces

abstract:
  Presented is description of kinematics and dynamics of material points with
internal degrees of freedom moving in a Riemannian manifold. The models of
internal degrees of freedom we concentrate on are based on the orthogonal and
affine groups. Roughly speaking, we consider infinitesimal gyroscopes and
homogeneously deformable gyroscopes (affienly-rigid bodies) in curved
manifolds. We follow our earlier models of extended rigid and affinely-rigid
bodies moving in a flat space. It is well known that in curved spaces in
general there is no well-defined concept of extended rigid or affinely-rigid
body. Our infinitesimal models are mathematically well defined and physically
they may be interpreted as an approximate description of "small" rigid and
affinely-rigid bodies. We derive equations of motion and show how internal
degrees of freedom interact with spatial geometry, first of all with the
curvature but also with the torsion. Integrability and degeneracy problems are
discussed.


title:
Universal properties of a single polymer chain in slit: Scaling versus
  MD simulations

abstract:
  We revisit the classical problem of a polymer confined in a slit in both of
its static and dynamic aspects. We confirm a number of well known scaling
predictions and analyse their range of validity by means of comprehensive
Molecular Dynamics simulations using a coarse-grained bead-spring model of a
flexible polymer chain.
  The normal and parallel components of the average end-to-end distance, mean
radius of gyration and their distributions, the density profile, the force
exerted on the slit walls, and the local bond orientation characteristics are
obtained in slits of width $D$ = $4 \div 10$ (in units of the bead radius) and
for chain lengths $N=50 \div 300$. We demonstrate that a wide range of static
chain properties in normal direction can be described {\em quantitatively} by
analytic model - independent expressions in perfect agreement with computer
experiment. In particular, the observed profile of confinement-induced bond
orientation, is shown to closely match theory predictions.
  The anisotropy of confinement is found to be manifested most dramatically in
the dynamic behavior of the polymer chain. We examine the relation between
characteristic times for translational diffusion and lateral relaxation. It is
demonstrated that the scaling predictions for lateral and normal relaxation
times are in good agreement with our observations. A novel feature is the
observed coupling of normal and lateral modes with two vastly different
relaxation times. We show that the impact of grafting on lateral relaxation is
equivalent to doubling the chain length.


title: Entanglement entropy, conformal invariance and extrinsic geometry

abstract:
  We use the conformal invariance and the holographic correspondence to fully
specify the dependence of entanglement entropy on the extrinsic geometry of the
2d surface $\Sigma$ that separates two subsystems of quantum strongly coupled
${\mathcal{N}}=4$ SU(N) superconformal gauge theory. We extend this result and
calculate entanglement entropy of a generic 4d conformal field theory. As a
byproduct, we obtain a closed-form expression for the entanglement entropy in
flat space-time when $\Sigma$ is sphere $S_2$ and when $\Sigma$ is
two-dimensional cylinder. The contribution of the type A conformal anomaly to
entanglement entropy is always determined by topology of surface $\Sigma$ while
the dependence of the entropy on the extrinsic geometry of $\Sigma$ is due to
the type B conformal anomaly.

categories: hep-th cond-mat.stat-mech gr-qc math.DG quant-ph


title: Moduli of polarized Hodge structures

abstract:
  Around 1970 Griffiths introduced the moduli of polarized Hodge structures/the
period domain $D$ and described a dream to enlarge $D$ to a moduli space of
degenerating polarized Hodge structures. Since in general $D$ is not a
Hermitian symmetric domain, he asked for the existence of a certain automorphic
cohomology theory for $D$, generalizing the usual notion of automorphic forms
on symmetric Hermitian domains. Since then there have been many efforts in the
first part of Griffith's dream but the second part still lives in darkness. The
objective of the present text is two-folded. First, we give an exposition of
the subject. Second, we give another formulation of the Griffiths problem,
based on the classical Weierstrass uniformization theorem.


title: Primordial black holes and asteroid danger

abstract:
  Probability for a primordial black hole to invade the Kuiper belt was
calculated. We showed that primordial black holes of certain masses can
significantly change asteroids' orbits. These events may result in disasters,
local for our solar system and global for the Earth (like the Tunguska
meteorite). We also estimated how often such events occur.


title: Perverse coherent sheaves on blow-up. I. a quiver description

abstract:
  This is the first of two papers studying moduli spaces of a certain class of
coherent sheaves, which we call {\it stable perverse coherent sheaves}, on the
blowup of a projective surface. They are used to relate usual moduli spaces of
stable sheaves on a surface and its blowup. In this first part, we give a
quiver (or ADHM) description of moduli spaces for framed perverse coherent
sheaves on the blowup of the projective plane.


title:
Transmission of information and synchronization in a pair of coupled
  chaotic circuits: an experimental overview

abstract:
  We propose a rationale for experimentally studying the intricate relationship
between the rate of information transmission and synchronization level in
active networks, applying theoretical results recently proposed. We consider
two non-identical coupled Chua's circuit with non-identical coupling strengths
in order to illustrate the proceeding for experimental scenarios of very few
data points coming from highly non-coherent coupled systems, such that phase
synchronization can only be detected by methods that do not rely explicitely on
the calculation of the phase. A relevant finding is to show that for the
coupled Chua's circuit, the larger the level of synchronization the larger the
rate of information exchanged between both circuits. We further validate our
findings with data from numerical simulations, and discuss an extension to
arbitrarily large active networks.


title: Rich-club vs rich-multipolarization phenomena in weighted networks

abstract:
  Large scale hierarchies characterize complex networks in different domains.
Elements at their top, usually the most central or influential, may show
multipolarization or tend to club forming tightly interconnected communities.
The rich-club phenomenon quantified this tendency based on unweighted network
representations. Here, we define this metric for weighted networks and discuss
the appropriate normalization which preserves nodes' strengths and discounts
structural strength-strength correlations if present. We find that in some real
networks the results given by the weighted rich-club coefficient can be in
sharp contrast to the ones in the unweighted approach. We also discuss that the
scanning of the weighted subgraphs formed by the high-strength hubs is able to
unveil features contrary to the average: the formation of local alliances in
rich-multipolarized environments, or a lack of cohesion even in the presence of
rich-club ordering. Beyond structure, this analysis matters for understanding
correctly functionalities and dynamical processes relying on hub
interconnectedness.


title: Classical and Quantized Affine Models of Structured Media

abstract:
  Having in view some applications in nanophysics, in particular in nanophysics
of materials, we develop new dynamical models of structured bodies with affine
internal degrees of freedom. In particular, we construct some models where not
only kinematics but also dynamics of systems of affine bodies is affinely
invariant. Quantization schemes are developed. This is necessary in the range
of physical phenomena we are interested in.


title: Glassy dynamics in monodisperse hard ellipsoids

abstract:
  We present evidence from computer simulations for glassy dynamics in
suspensions of monodisperse hard ellipsoids. In equilibrium, almost spherical
ellipsoids show a first order transition from an isotropic phase to a rotator
phase. When overcompressing the isotropic phase into the rotator regime, we
observe super-Arrhenius slowing down of diffusion and relaxation, accompanied
by two-step relaxation in positional and orientational correlators. The effects
are strong enough for asymptotic laws of mode-coupling theory to apply. Glassy
dynamics are unusual in monodisperse systems. Typically, polydispersity in size
or a mixture of particle species is prerequisite to prevent crystallization.
Here, we show that a slight particle anisometry acts as a sufficient source of
disorder. This sheds new light on the question of which ingredients are
required for glass formation.


title:
Penalized model-based clustering with cluster-specific diagonal
  covariance matrices and grouped variables

abstract:
  Clustering analysis is one of the most widely used statistical tools in many
emerging areas such as microarray data analysis. For microarray and other
high-dimensional data, the presence of many noise variables may mask underlying
clustering structures. Hence removing noise variables via variable selection is
necessary. For simultaneous variable selection and parameter estimation,
existing penalized likelihood approaches in model-based clustering analysis all
assume a common diagonal covariance matrix across clusters, which however may
not hold in practice. To analyze high-dimensional data, particularly those with
relatively low sample sizes, this article introduces a novel approach that
shrinks the variances together with means, in a more general situation with
cluster-specific (diagonal) covariance matrices. Furthermore, selection of
grouped variables via inclusion or exclusion of a group of variables altogether
is permitted by a specific form of penalty, which facilitates incorporating
subject-matter knowledge, such as gene functions in clustering microarray
samples for disease subtype discovery. For implementation, EM algorithms are
derived for parameter estimation, in which the M-steps clearly demonstrate the
effects of shrinkage and thresholding. Numerical examples, including an
application to acute leukemia subtype discovery with microarray gene expression
data, are provided to demonstrate the utility and advantage of the proposed
method.


title: Quantum Systems on Linear Groups

abstract:
  Discussed are quantized dynamical systems on orthogonal and affine groups.
The special stress is laid on geodetic systems with affinely-invariant kinetic
energy operators. The resulting formulas show that such models may be useful in
nuclear and hadronic dynamics. They differ from traditional Bohr-Mottelson
models where SL$(n,\mathbb{R})$ is used as a so-called non-invariance group.
There is an interesting relationship between classical and quantized integrable
lattices.


title:
SUSY interpretation of the Egret GeV anomaly, Xenon-10 dark matter
  search limits and the LHC

abstract:
  The observation of the Egret experiment of an excess of diffuse gamma rays
with energies above E_\gamma =1 GeV has previously been interpreted in the
context of the minimal supergravity model (mSUGRA) as coming from neutralino
annihilation into mainly b-quarks in the galactic halo, with neutralino mass in
the vicinity of 50-70 GeV. We observe that in order to obtain the correct relic
abundance of neutralinos in accord with WMAP measurements, the corresponding
neutralino-proton direct detection (DD) rates should be in excess of recent
limits from the Xenon-10 collaboration. While it does not appear possible to
satisfy the Egret, WMAP and Xenon-10 constraints simultaneously within the
mSUGRA model, we find that it is easily possible in models with non-universal
Higgs soft masses (NUHM). In either case, gluino pair production from
m(gluino)\sim 400-500 GeV should occur at large rates at the CERN LHC, and a
gluino pair production signal should be visible with just 0.1 fb^{-1} of
integrated luminosity. The NUHM interpretation predicts a rather light spectrum
of heavy Higgs bosons with m_A\sim 140-200 GeV over the whole parameter space
which would interpret Egret data. Spin-independent DD rates are predicted to be
just above 10^{-8} pb, within range of the next round of direct dark matter
detection experiments.


title:
$L^p$ Boundedness of Commutators of Riesz Transforms associated to
  Schr\"{o}dinger Operator

abstract:
  In this paper we consider $L^p$ boundedness of some commutators of Riesz
transforms associated to Schr\"{o}dinger operator $P=-\Delta+V(x)$ on
$\mathbb{R}^n, n\geq 3$. We assume that $V(x)$ is non-zero, nonnegative, and
belongs to $B_q$ for some $q \geq n/2$. Let $T_1=(-\Delta+V)^{-1}V,\
T_2=(-\Delta+V)^{-1/2}V^{1/2}$ and $T_3=(-\Delta+V)^{-1/2}\nabla$. We obtain
that $[b,T_j] (j=1,2,3)$ are bounded operators on $L^p(\mathbb{R}^n)$ when $p$
ranges in a interval, where $b \in \mathbf{BMO}(\mathbb{R}^n)$. Note that the
kernel of $T_j (j=1,2,3)$ has no smoothness.


title: An explicit finite difference scheme for the Camassa-Holm equation

abstract:
  We put forward and analyze an explicit finite difference scheme for the
Camassa-Holm shallow water equation that can handle general $H^1$ initial data
and thus peakon-antipeakon interactions. Assuming a specified condition
restricting the time step in terms of the spatial discretization parameter, we
prove that the difference scheme converges strongly in $H^1$ towards a
dissipative weak solution of Camassa-Holm equation.


title:
Reaching for equilibrium : an alternative view of the unbalanced carbon
  cycle

abstract:
  A model is proposed to explain the observed correlation between monthly
fluctuations in atmospheric CO2 concentrations and temperatures. The model
relies on the oceans being in a temperature-dependent equilibrium with the
atmosphere. When temperature changes, the system attempts to restore the
equilibrium, with a time constant constrained by the dynamic fluxes between the
two. The model is used to reconstruct both the historic evolution of CO2
concentrations since 1885, as well as the monthly fluctuations since 1959. The
best fit is obtained with the southern hemisphere sea surface temperature data.
In this new picture, human emissions play no role in the build-up of
atmospheric CO2, but do contribute to the fluxes that restore the equilibrium.


title:
Properties of entangled photon pairs generated by a CW laser with small
  coherence time: theory and experiment

abstract:
  The generation of entangled photon pairs by parametric down--conversion from
solid state CW lasers with small coherence time is theoretically and
experimentally analyzed. We consider a compact and low-cost setup based on a
two-crystal scheme with Type-I phase matching. We study the effect of the pump
coherence time over the entangled state visibility and over the violation of
Bell's inequality, as a function of the crystals length. The full density
matrix is reconstructed by quantum tomography. The proposed theoretical model
is verified using a purification protocol based on a compensation crystal.


title:
Survey of intermediate/high-mass star-forming regions at centimeter and
  millimeter wavelengths

abstract:
  We present the results of millimeter and centimeter continuum observations,
made with the IRAM 30m telescope and the VLA, toward a sample of 11 luminous
IRAS sources classified as high-mass protostellar object candidates. We find
1.2 mm emission for all (but one) regions likely tracing the dust core in which
the massive young stellar object is forming, for which we estimate masses
ranging from 10 to 140 Msun. For all the sources, but one, we detect centimeter
emission associated with the IRAS source, being compact or ultracompact HII
region candidates, with early B-type stars as ionizing stars. The 7 mm emission
is partially resolved for the four sources observed at this wavelength, with
contribution of dust emission at 7 mm ranging from negligible to 44%. By
combining our data with infrared surveys we fitted the spectral energy
distribution of the sources. Finally, we find a correlation between the degree
of disruption of the natal cloud, estimated from the fraction of dust emission
associtaed with the centimeter source relative to the total amount of dust in
its surroundings, and the size of the centimeter source. From this correlation,
we establish an evolutionary sequence which is consistent with the evolutionary
stage expected from maser/outflow/dense gas emission and with the infrared
excess.


title:
Time-reversal symmetry violation and the structure of Superconducting
  Order Parameter of PrOs$_{4}$Sb$_{12}$

abstract:
  The antisymmetrised two-electron functions are constructed for the point
group T$_{h}$, i.e. the symmetry group of unconventional superconductor PrOs$%
_{4}$Sb$_{14}$., and its subgroup D$_{2h}$.The nodal structure of these
function depending on the wavevector group is investigated. Theoretical nodal
structure of these functions made possible to explain the experimental nodal
structure PrOs$_{4}$Sb$_{14}$. as a result of time-reversal symmetry violation.


title:
Effect of the surface polarization in polar perovskites studied from
  first principles

abstract:
  The (001) surfaces of polar perovskites BaTiO$_3$ and PbTiO$_3$ have been
studied from first principles at T=0 K. For both cases of polarization, the
most stable TiO-terminated interfaces show intrinsic ferroelectricity. In the
topmost layer, where the O atoms are $>$0.1 \AA above Ti, this leads to
metallic instead of the insulating behavior of the electronic states that may
have important implications for multiferroic tunneling junctions.


title: Domain Walls with Non-Abelian Clouds

abstract:
  Domain walls in U(N) gauge theories, coupled to Higgs scalar fields with
degenerate masses, are shown to possess normalizable non-Abelian
Nambu-Goldstone(NG) modes, which we call non-Abelian clouds. We construct the
moduli space metric and its Kahler potential of the effective field theory on
the domain walls, by focusing on two models: a U(1) gauge theory with several
charged Higgs fields, and a U(N) gauge theory with 2N Higgs fields in the
fundamental representation. We find that non-Abelian clouds spread between two
domain walls and that their rotation induces long-range repulsive force, in
contrast to a U(1) mode in models with fully non-degenerate masses which gives
short-range force. We also construct a bound state of dyonic domain walls by
introducing the imaginary part of the Higgs masses. In the latter model we find
that when all walls coincide SU(N)_L x SU(N)_R x U(1) symmetry is broken down
to SU(N)_V, and U(N)_A NG modes and the same number of quasi-NG modes are
localized on the wall. When n walls separate, off diagonal elements of U(n) NG
modes have wave functions spreading between two separated walls (non-Abelian
clouds), whereas some quasi-NG modes turn to NG bosons as a result of further
symmetry breaking U(n)_V --> U(1)_V^n. In the case of 4+1 dimensional bulk, we
can dualize the effective theory to the supersymmetric Freedman-Townsend model
of non-Abelian 2-form fields.


title: Joyce invariants for K3 surfaces and mock theta functions

abstract:
  We will discuss Joyce invariants of stability conditions for K3 surfaces and
mock theta functions.


title: Design and Implementation of Aggregate Functions in the DLV System

abstract:
  Disjunctive Logic Programming (DLP) is a very expressive formalism: it allows
for expressing every property of finite structures that is decidable in the
complexity class SigmaP2 (= NP^NP). Despite this high expressiveness, there are
some simple properties, often arising in real-world applications, which cannot
be encoded in a simple and natural manner. Especially properties that require
the use of arithmetic operators (like sum, times, or count) on a set or
multiset of elements, which satisfy some conditions, cannot be naturally
expressed in classic DLP.
  To overcome this deficiency, we extend DLP by aggregate functions in a
conservative way. In particular, we avoid the introduction of constructs with
disputed semantics, by requiring aggregates to be stratified. We formally
define the semantics of the extended language (called DLP^A), and illustrate
how it can be profitably used for representing knowledge. Furthermore, we
analyze the computational complexity of DLP^A, showing that the addition of
aggregates does not bring a higher cost in that respect. Finally, we provide an
implementation of DLP^A in DLV -- a state-of-the-art DLP system -- and report
on experiments which confirm the usefulness of the proposed extension also for
the efficiency of computation.


title: Convergence of weighted polynomial multiple ergodic averages

abstract:
  We study here weighted polynomial multiple ergodic averages. A sequence of
weights is called universally good if any polynomial multiple ergodic average
with this sequence of weights converges in $L^{2}$. We find a necessary
condition and show that for any bounded measurable function $\phi$ on an
ergodic system, the sequence $\phi(T^{n}x)$ is universally good for almost
every $x$. The linear case was understood by Host and Kra.


title: Extreme Lagrangian acceleration in confined turbulent flow

abstract:
  A Lagrangian study of two-dimensional turbulence for two different
geometries, a periodic and a confined circular geometry, is presented to
investigate the influence of solid boundaries on the Lagrangian dynamics. It is
found that the Lagrangian acceleration is even more intermittent in the
confined domain than in the periodic domain. The flatness of the Lagrangian
acceleration as a function of the radius shows that the influence of the wall
on the Lagrangian dynamics becomes negligible in the center of the domain and
it also reveals that the wall is responsible for the increased intermittency.
The transition in the Lagrangian statistics between this region, not directly
influenced by the walls, and a critical radius which defines a Lagrangian
boundary layer, is shown to be very sharp with a sudden increase of the
acceleration flatness from about 5 to about 20.


title:
A coarse-grained Langevin molecular dynamics approach to de novo protein
  structure prediction

abstract:
  De novo prediction of protein structures, the prediction of structures from
amino-acid sequences which are not similar to those of hitherto resolved
structures, has been one of the major challenges in molecular biophysics. In
this paper, we develop a new method of de novo prediction, which combines the
fragment assembly method and the simulation of physical folding process:
Structures which have consistently assembled fragments are dynamically searched
by Langevin molecular dynamics of conformational change. The benchmarking test
shows that the prediction is improved when the candidate structures are
cross-checked by an empirically derived score function.


title: Testing the number of parameters with multidimensional MLP

abstract:
  This work concerns testing the number of parameters in one hidden layer
multilayer perceptron (MLP). For this purpose we assume that we have
identifiable models, up to a finite group of transformations on the weights,
this is for example the case when the number of hidden units is know. In this
framework, we show that we get a simple asymptotic distribution, if we use the
logarithm of the determinant of the empirical error covariance matrix as cost
function.


title:
Efficient Estimation of Multidimensional Regression Model with
  Multilayer Perceptron

abstract:
  This work concerns estimation of multidimensional nonlinear regression models
using multilayer perceptron (MLP). The main problem with such model is that we
have to know the covariance matrix of the noise to get optimal estimator.
however we show that, if we choose as cost function the logarithm of the
determinant of the empirical error covariance matrix, we get an asymptotically
optimal estimator.


title:
Estimation of linear autoregressive models with Markov-switching, the
  E.M. algorithm revisited

abstract:
  This work concerns estimation of linear autoregressive models with
Markov-switching using expectation maximisation (E.M.) algorithm. Our method
generalise the method introduced by Elliot for general hidden Markov models and
avoid to use backward recursion.


title: Electromagnetic Decays of Vector Mesons in a Covariant Model

abstract:
  A fully covariant model for describing the electromagnetic decay of Vector
  Mesons, both in light and in heavy sectors, is presented. The main
ingredients of our approach are i) an Ansatz for the Bethe-Salpeter vertex for
Vector Mesons, and ii) a Mandelstam-like formula for the electromagnetic decay
constant. The free parameters of our approach are fixed through a comparison
with the transverse momentum distribution obtained within a
  Light-Front Hamiltonian Dynamics framework with constituent quarks.
  Preliminary results for both the decays constants and the probability of the
valence component are shown.


title: The Virgin Island Model

abstract:
  A continuous mass population model with local competition is constructed
where every emigrant colonizes an unpopulated island. The population founded by
an emigrant is modeled as excursion from zero of an one-dimensional diffusion.
With this excursion measure, we construct a process which we call Virgin Island
Model. Furthermore, a necessary and sufficient condition for extinction of the
total population is obtained for finite initial total mass.


title:
Infrared Properties Of AGB Stars: from Existing Databases to Antarctic
  Surveys

abstract:
  We present here a study of the Infrared properties of Asymptotic Giant Branch
stars (hereafter AGB) based on existing databases, mainly from space-borne
experiments. Preliminary results about C and S stars are discussed, focusing on
the topics for which future Infrared surveys from Antarctica will be crucial.
This kind of surveys will help in making more quantitative our knowledge of the
last evolutionary stages of low mass stars, especially for what concerns
luminosities and mass loss.


title:
Continued fraction approximation for the nuclear matter response
  function

abstract:
  We use a continued fraction approximation to calculate the RPA response
function of nuclear matter. The convergence of the approximation is assessed by
comparing with the numerically exact response function obtained with a typical
effective finite-range interaction used in nuclear physics. It is shown that
just the first order term of the expansion can give reliable results at
densities up to the saturation density value.


title:
Chemical composition of A and F dwarfs members of the Pleiades open
  cluster

abstract:
  Abundances of 18 chemical elements have been derived for 16 A (normal and
chemically peculiar CP) and 5 F dwarfs members of the Pleiades open cluster in
order to set constraints on evolutionary models. The abundances, rotational
velocities and microturbulent velocities were derived by iteratively adjusting
synthetic spectra to observations at high resolution (R~42000 and R~75000) and
high signal-to-noise (S/N) ratios. The abundances obtained do not exhibit any
clear correlation with the effective temperature nor the projected rotational
velocity. Interestingly, A stars exhibit larger star-to-star variations in C,
Sc, Ti, V, Cr, Mn, Sr, Y, Zr and Ba than F stars. F stars exhibit solar
abundances for almost all the elements. In A stars, the abundances of Si, Ti
and Cr are found to be correlated with that of Fe, the [X/Fe] ratios being
solar for these three elements. The derived abundances have been compared to
the predictions of published evolutionary models at the age of Pleiades (100
Myr). For the F stars, the predicted slight underabundances of light elements
and overabundances of Cr, Fe and Ni are indeed confirmed by our findings. For A
stars, the predicted overabundances in iron peak elements are confirmed in a
few stars only. The large scatter of the abundances in A stars, already found
in the Hyades, Coma Berenices and the UMa group and in field stars appears to
be a characteristic property of dwarf A stars. The occurence of hydrodynamical
processes competing with radiative diffusion in the radiative zones of the A
dwarfs might account for the found scatter in abundances.


title: On the Linear Combinants of a Binary Pencil

abstract:
  Let A,B denote binary forms of order d, and let C_{2r-1} = (A,B)_{2r-1} be
the sequence of their linear combinants for r between 1 and (d+1)/2. It is
known that C_1 and C_3 together determine the pencil generated by A and B, and
hence indirectly the higher C_{2r-1}. In this paper we exhibit explicit
formulae for all r>2, which allow us to recover C_{2r-1} from the knowledge of
C_1 and C_3. The calculations make use of the symbolic method of classical
invariant theory, as well as the quantum theory of angular momentum. Our
theorem pertains to the second exterior power representation of S_d, for the
group SL_2. We give an example for the group SL_3 to show that such a result
may hold for other categories of representations.


title: Self Organizing Map algorithm and distortion measure

abstract:
  We study the statistical meaning of the minimization of distortion measure
and the relation between the equilibrium points of the SOM algorithm and the
minima of distortion measure. If we assume that the observations and the map
lie in an compact Euclidean space, we prove the strong consistency of the map
which almost minimizes the empirical distortion. Moreover, after calculating
the derivatives of the theoretical distortion measure, we show that the points
minimizing this measure and the equilibria of the Kohonen map do not match in
general. We illustrate, with a simple example, how this occurs.


title:
Odd triplet superconductivity in superconductor-ferromagnet structures
  with a narrow domain wall

abstract:
  We study the proximity effect in superconductor-ferromagnet (SF) structure
with a narrow domain wall (DW) at the SF interface. The width of the domain
wall is assumed to be larger than the Fermi wave length, but smaller than other
characteristic lengths (for example, the ''magnetic'' length). The transmission
coefficient is supposed to be small so that we deal with a weak proximity
effect. Solving the linearized Eilenberger equation, we find analytical
expressions for quasiclassical Green's functions. These functions describe the
short-range (SR) condensate components, singlet and triplet with zero
projection of the total spin on the quantization z-axis, induced in F due to
the proximity effect as well as long-range odd triplet component (LRTC) with a
nonzero projection of the total spin of Cooper pairs on the $z$% -axis. The
amplitude of the LRTC essentially depends on the product $h\tau $ and increases
with increasing the exchange energy $h$ ($\tau $ is the elastic scattering
time). We calculate the Josephson current in SFS junction with a thickness of
the F layer much greater than the penetration length of the SR components. The
Josephson critical current caused by the LRTC may be both positive and negative
depending on chirality of the magnetic structure in F.
  The density of states (DOS) in a diffusive SF bilayer is also analyzed. It is
shown that the contributions of the SR and LR components to the DOS in F have a
different dependence on the thickness $d$ of the F layer (nonmonotonous and
monotonous).


title:
Efficient Estimation of Multidimensional Regression Model using
  Multilayer Perceptrons

abstract:
  This work concerns the estimation of multidimensional nonlinear regression
models using multilayer perceptrons (MLPs). The main problem with such models
is that we need to know the covariance matrix of the noise to get an optimal
estimator. However, we show in this paper that if we choose as the cost
function the logarithm of the determinant of the empirical error covariance
matrix, then we get an asymptotically optimal estimator. Moreover, under
suitable assumptions, we show that this cost function leads to a very simple
asymptotic law for testing the number of parameters of an identifiable MLP.
Numerical experiments confirm the theoretical results.


title:
A note on the regularity of solutions of Hamilton-Jacobi equations with
  superlinear growth in the gradient variable

abstract:
  We investigate the regularity of solutions of first order Hamilton-Jacobi
equation with super linear growth in the gradient variable. We show that the
solutions are locally H\"older continuous with H\"older exponent depending only
on the growth of the Hamiltonian. The proof relies on a reverse H\"older
inequality.


title:
Scaling limits of $(1+1)$-dimensional pinning models with Laplacian
  interaction

abstract:
  We consider a random field $\varphi:\{1,...,N\}\to \mathbb{R}$ with Laplacian
interaction of the form $\sum_iV(\Delta\varphi_i)$, where $\Delta$ is the
discrete Laplacian and the potential $V(\cdot)$ is symmetric and uniformly
strictly convex. The pinning model is defined by giving the field a reward
$\varepsilon\ge0$ each time it touches the x-axis, that plays the role of a
defect line. It is known that this model exhibits a phase transition between a
delocalized regime $(\varepsilon<\varepsilon_c)$ and a localized one
$(\varepsilon>\varepsilon_c)$, where $0<\varepsilon_c<\infty$. In this paper we
give a precise pathwise description of the transition, extracting the full
scaling limits of the model. We show, in particular, that in the delocalized
regime the field wanders away from the defect line at a typical distance
$N^{3/2}$, while in the localized regime the distance is just $O((\log N)^2)$.
A subtle scenario shows up in the critical regime
$(\varepsilon=\varepsilon_c)$, where the field, suitably rescaled, converges in
distribution toward the derivative of a symmetric stable L\'evy process of
index 2/5. Our approach is based on Markov renewal theory.


title: Decaying Majoron Dark Matter and Neutrino Masses

abstract:
  We review the recent proposal by Lattanzi & Valle of the majoron as a
suitable warm dark matter candidate. The majoron is the Goldstone boson
associated to the spontaneous breaking of ungauged lepton number, one of the
mechanisms proposed to give rise to neutrino masses. The majoron can acquire a
mass through quantum gravity effects, and can possibly account for the observed
dark matter component of the Universe. We present constraints on the majoron
lifetime, mass and abundance obtained by the analysis of the cosmic microwave
background data. We find that, in the case of thermal production, the limits
for the majoron mass read 0.12 keV<m_J<0.17 keV, and discuss how these limits
are modified in the non-thermal case. The majoron lifetime is constrained to be
larger than 250 Gyrs. We also apply this results to a given seesaw model for
the generation of neutrino masses, and find that this constraints the energy
scale for the lepton number breaking phase transition to be above 10^6 GeV. We
thus find that the majoron decaying dark matter (DDM) scenario fits nicely in
models where neutrino masses arise "a la seesaw" and may lead to other possible
cosmological implications.


title: Infrared Spectroscopy of the Diffuse Ionized Halo of NGC 891

abstract:
  We present infrared spectroscopy from the Spitzer Space Telescope at one disk
position and two positions at a height of 1 kpc from the disk in the edge-on
spiral NGC 891, with the primary goal of studying halo ionization. Our main
result is that the [Ne III]/[Ne II] ratio, which provides a measure of the
hardness of the ionizing spectrum free from the major problems plaguing optical
line ratios, is enhanced in the extraplanar pointings relative to the disk
pointing. Using a 2D Monte Carlo-based photo-ionization code which accounts for
the effects of radiation field hardening, we find that this trend cannot be
reproduced by any plausible photo-ionization model, and that a secondary source
of ionization must therefore operate in gaseous halos. We also present the
first spectroscopic detections of extraplanar PAH features in an external
normal galaxy. If they are in an exponential layer, very rough emission
scale-heights of 330-530 pc are implied for the various features. Extinction
may be non-negligible in the midplane and reduce these scale-heights
significantly. There is little significant variation in the relative emission
from the various features between disk and extraplanar environment. Only the
17.4 micron feature is significantly enhanced in the extraplanar gas compared
to the other features, possibly indicating a preference for larger PAHs in the
halo.


title: Dynamics study of $Z^+(4430)$ and X(3872) in molecular picture

abstract:
  In this talk, we review our recent work about the dynamical studies of
$Z^+(4430)$ and X(3872). $Z^+(4430)$ can not be explained as a $D_1'D^*$ or
$D_1D^*$ molecular state only considering one pion exchange potential without
the cutoff, which needs to be confirmed by introducing sigma exchange potential
and adding the cutoff in the effective potential. One also excludes the
possibility of X(3872) as a $DD^*$ molecular state by one pion and one sigma
exchanges with the cutoff. Fortunately there exists an S-wave $BB^*$ bound
state with $J^{PC}=1^{++}$. we suggest future experiment to search this state.


title: Probing ultra-cold Fermi atoms with a single ion

abstract:
  We show that the recently proposed ionic microscope set-up [Kollath et.al,
PRA, \textbf{76}, 063602 (2007)] could be adapted to measure the \textit {local
single-particle energy distribution} of a degenerate Fermi gas \textit{in situ}
with the resolution on the nanometer scale. We study an ion held in a Paul trap
in an atomic Fermi gas and compute the two-photon Raman photo-association rate
of the ion and an atom. We show that, as a function of the detunings between
the frequencies of the two incident lasers and energies in the atom-ion system,
the photo-association rate directly measures the single-particle energy
distribution in the Fermi gas around the ion. We describe an experiment to
measure the photo-association rate of a trapped ion and argue that, as the
position of the ion can be scanned through the Fermi gas, this experiment
directly probes the local energy and spin-state distribution of the Fermi gas.


title: Finite element method calculations of ZnO nanowires for nanogenerators

abstract:
  The bending of a nonconducting piezoelectric ZnO nanowire is simulated by
finite element method calculations. The top part is bent by a lateral force,
which could be applied by an atomic force microscope (AFM) tip. The generated
electrical potential is 0.3 V. This relatively high signal is, however,
difficult to measure, due to the low capacitance of the ZnO nanowire (4x10^{-5}
pF) as compared to the capacitance of most preamplifiers (5 pF). A further
problem arises from the semiconducting properties of experimentally fabricated
ZnO nanowires which causes the disappearance of the voltage signal within
picoseconds.


title: Models of Modular Inflation and Their Phenomenological Consequences

abstract:
  We study models of modular inflation of the form expected to arise from low
energy effective actions of superstring theories. We argue on general grounds
that the most likely models of modular slow-roll inflation are small field
models in which the inflaton moves about a Planck distance from an extremum of
the potential. We then focus on models in which the inflaton is the bosonic
component of a single (complex) chiral superfield and explain the generic
difficulties in designing small field models of modular inflation. We then show
that if the Kaehler potential (KP) of the inflaton is logarithmic as in
perturbative string theories, then it is not possible to satisfy the slow-roll
conditions for any superpotential. We find that if the corrections to the KP
are large enough so it can be approximated by a canonical KP in the vicinity of
the extremum, then viable slow-roll inflation is possible. In this case,
several parameters have to be tuned to a fraction of a percent. We give a
prescription for designing successful small field supergravity models of
inflation when the KP is canonical and calculate the slow-roll parameters from
the superpotential parameters. Our results strengthen the case for models in
which the moduli slowly roll about a Planck distance from a relatively high
scale extremum that is located in the vicinity of the central region of moduli
space units. Generic models of this class predict a red spectrum of scalar
perturbations and negligible spectral index running. They also predict a
characteristic suppression of tensor perturbations despite the high scale of
inflation. Consequently, a detection of primordial tensor anisotropies or
spectral index running in cosmic microwave background observations in the
foreseeable future will rule out this entire class of modular inflation models.


title:
Experimentally generating and tuning robust entanglement between
  photonic qubits

abstract:
  We generate and study the entanglement properties of novel states composed of
three polarisation-encoded photonic qubits. By varying a single experimental
parameter we can coherently move from a fully separable state to a maximally
robust W state, while at all times preserving an optimally robust, symmetric
entanglement configuration. We achieve a high fidelity with these
configurations experimentally, including the highest reported W state fidelity.


title: Ideal intersections for radio-frequency trap networks

abstract:
  We investigate the possible form of ideal intersections for two-dimensional
rf trap networks suitable for quantum information processing with trapped ions.
We show that the lowest order multipole component of the rf field that can
contribute to an ideal intersection is a hexapole term uniquely determined by
the tangents of the intersecting paths. The corresponding ponderomotive
potential does not provide any confinement perpendicular to the paths if these
intersect at right angles, indicating that ideal right-angle X intersections
are impossible to achieve with hexapole fields. Based on this result, we
propose an implementation of an ideal oblique-X intersection using a
three-dimensional electrode structure.


title:
Creation, manipulation, and detection of Abelian and non-Abelian anyons
  in optical lattices

abstract:
  Anyons are particlelike excitations of strongly correlated phases of matter
with fractional statistics, characterized by nontrivial changes in the wave
function, generalizing Bose and Fermi statistics, when two of them are
interchanged. This can be used to perform quantum computations [A. Yu. Kitaev,
Ann. Phys. (N.Y.) 303, 2 (2003)]. We show how to simulate the creation and
manipulation of Abelian and non- Abelian anyons in topological lattice models
using trapped atoms in optical lattices. Our proposal, feasible with present
technology, requires an ancilla particle which can undergo single-particle
gates, be moved close to each constituent of the lattice and undergo a simple
quantum gate, and be detected.


title:
A non-Hermitian $PT-$symmetric Bose-Hubbard model: eigenvalue rings from
  unfolding higher-order exceptional points

abstract:
  We study a non-Hermitian $PT-$symmetric generalization of an $N$-particle,
two-mode Bose-Hubbard system, modeling for example a Bose-Einstein condensate
in a double well potential coupled to a continuum via a sink in one of the
wells and a source in the other. The effect of the interplay between the
particle interaction and the non-Hermiticity on characteristic features of the
spectrum is analyzed drawing special attention to the occurrence and unfolding
of exceptional points (EPs). We find that for vanishing particle interaction
there are only two EPs of order $N+1$ which under perturbation unfold either
into $[(N+1)/2]$ eigenvalue pairs (and in case of $N+1$ odd, into an additional
zero-eigenvalue) or into eigenvalue triplets (third-order eigenvalue rings) and
$(N+1)\mod 3$ single eigenvalues, depending on the direction of the
perturbation in parameter space. This behavior is described analytically using
perturbational techniques. More general EP unfoldings into eigenvalue rings up
to $(N+1)$th order are indicated.


title: Tridiagonal pairs of shape (1,2,1)

abstract:
  Let $\mathbb F$ denote a field and let $V$ denote a vector space over
$\mathbb F$ with finite positive dimension. We consider a pair of linear
transformations $A:V\to V$ and $A^*:V\to V$ that satisfies the following
conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an
ordering $\lbrace V_i \rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^*
V_i \subseteq V_{i-1}+V_i+V_{i+1}$ for $0 \leq i \leq d$, where $V_{-1} = 0$
and $V_{d+1} = 0$; (iii) there exists an ordering $\lbrace V^*_i
\rbrace_{i=0}^{\delta}$ of the eigenspaces of $A^*$ such that $AV^*_i \subseteq
V^*_{i-1}+V^*_i+V^*_{i+1}$ for $0 \leq i \leq \delta $, where $V^*_{-1} = 0$
and $V^*_{\delta+1} = 0$; (iv) there is no subspace $W$ of $V$ such that
$AW\subseteq W$, $A^*W\subseteq W$, $W \neq 0, W \neq V$. We call such a pair a
{\it tridiagonal pair} on $V$. It is known that $d = \delta$ and that for $0
\leq i \leq d$ the dimensions of $V_i, V_{d-i}, V^*_i, V^*_{d-i}$ coincide; we
denote this common value by $\rho_i$. The sequence $\lbrace
\rho_i\rbrace_{i=0}^d$ is called the {\it shape} of the pair. In this paper we
assume the shape is $(1,2,1)$ and obtain the following results. We describe six
bases for $V$; one diagonalizes $A$, another diagonalizes $A^*$, and the other
four underlie the split decompositions for $A,A^*$. We give the action of $A$
and $A^*$ on each basis. For each ordered pair of bases among the six, we give
the transition matrix. At the end we classify the tridiagonal pairs of shape
$(1,2,1)$ in terms of a sequence of scalars called the parameter array.


title:
The nodal gap component as a good candidate for the superconducting
  order parameter in cuprates

abstract:
  Although more than twenty years have passed since the discovery of high
temperature cuprate superconductivity, the identification of the
superconducting order parameter is still under debate. Here, we show that the
nodal gap component is the best candidate for the superconducting order
parameter. It scales with the critical temperature $T_c$ over a wide doping
range and displays a significant temperature dependence below $T_c$ in both the
underdoped and the overdoped regimes of the phase diagram. In contrast, the
antinodal gap component does not scale with $T_c$ in the underdoped side and
appears to be controlled by the pseudogap amplitude. Our experiments establish
the existence of two distinct gaps in the underdoped cuprates.


title: Decay estimates for a class of wave equations

abstract:
  In this paper we use a unified way studying the decay estimate for a class of
dispersive semigroup given by $e^{it\phi(\sqrt{-\Delta})}$, where $\phi:
\mathbb{R}^+\to \mathbb{R}$ is smooth away from the origin. Especially, the
decay estimates for the solutions of the Klein-Gordon equation and the beam
equation are simplified and slightly improved.


title: Optical spectra and exchange-correlation effects in molecular crystals

abstract:
  We report first-principles GW-Bethe Salpeter Equation and Quantum Monte Carlo
calculations of the optical and electronic properties of molecular and
crystalline rubrene (C$_{42}$H$_{28}$). Many-body effects dominate the optical
spectrum and quasi-particle gap of molecular crystals. We interpret the
observed yellow-green photoluminescence in rubrene microcrystals as a result of
the formation of intermolecular, charge-transfer spin-singlet excitons. In
contrast, spin-triplet excitons are localized and intramolecular with a
predicted phosphorescence at the red end of the optical spectrum. We find that
the exchange energy plays a fundamental role in raising the energy of
intramolecular spin-singlet excitons above the intermolecular ones. Exciton
binding energies are predicted to be around 0.5 eV (spin singlet) to 1 eV (spin
triplet). The calculated electronic gap is 2.8 eV. The theoretical absorption
spectrum agrees very well with recent ellipsometry data.


title: Neutron Beam Effects on Spin Exchange Polarized He-3

abstract:
  We have observed depolarization effects when high intensity cold neutron
beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as
neutron spin filters. This was first observed as a reduction of the maximum
attainable He-3 polarization and was attributed to a decrease of alkali-metal
polarization, which led us to directly measure alkali-metal polarization and
spin relaxation over a range of neutron fluxes at LANSCE and ILL. The data
reveal a new alkali-metal spin-relaxation mechanism that approximately scales
as the square root of the neutron capture-flux density incident on the cell.
This is consistent with an effect proportional to the recombination-limited ion
concentration, but is much larger than expected from earlier work.


title:
Fat tails, long memory, maturity and ageing in open-source software
  projects

abstract:
  We report activity data analysis on several open source software projects,
focusing on time between modifications and on the number of files modified at
once. Both have fat-tailed distributions, long-term memory, and display
systematic non-trivial cross-correlations, suggesting that quiet periods are
followed by cascading modifications. In addition the maturity of a software
project can be measured from the exponent of the distribution of
inter-modification time. Finally, the dynamics of a single file displays
ageing, the average rate of modifications decaying as a function of time
following a power-law.


title: Cosmological Feynman Paths

abstract:
  Arrowed-time divergence-free rules or cosmological quantum dynamics are
formulated through stepped Feynman paths across macroscopic slices of Milne
spacetime. Slice boundaries house totally-relativistic rays representing
elementary entities--preons. Total relativity and the associated preon Fock
space, despite distinction from special relativity (which lacks time arrow),
are based on the Lorentz group. Each path is a set of cubic vertices connected
by straight, directed and stepped arcs that carry inertial, electromagnetic and
gravitational action. The action of an arc step comprises increments each
bounded by Planck's constant. Action from extremely-distant sources is
determined by universe mean energy density. Identifying the arc-step energy
that determines inertial action with that determining gravitational action
establishes both arc-step length and universe density. Special relativity is
accurate for physics at laboratory spacetime scales far below that of Hubble
and far above that of Planck.


title: Lambda hyperonic effect on the normal driplines

abstract:
  A generalized mass formula is used to calculate the neutron and proton drip
lines of normal and lambda hypernuclei treating non-strange and strange nuclei
on the same footing. Calculations suggest existence of several bound
hypernuclei whose normal cores are unbound. Addition of Lambda or,
Lambda-Lambda hyperon(s) to a normal nucleus is found to cause shifts of the
neutron and proton driplines from their conventional limits.


title: All-optical trapping and acceleration of heavy particles

abstract:
  A scheme for fast, compact, and controllable acceleration of heavy particles
in vacuum is proposed, in which two counterpropagating lasers with variable
frequencies drive a beat-wave structure with variable phase velocity, thus
allowing for trapping and acceleration of heavy particles, such as ions or
muons. Fine control over the energy distribution and the total charge of the
beam is obtained via tuning of the frequency variation. The acceleration scheme
is described with a one-dimensional theory, providing the general conditions
for trapping and scaling laws for the relevant features of the particle beam.
Two-dimensional, electromagnetic particle-in-cell simulations confirm the
validity and the robustness of the physical mechanism.


title:
Spectrum of the Lichnerowicz Laplacian on asymptotically hyperbolic
  surfaces

abstract:
  We show that, on any asymptotically hyperbolic surface, the essential
spectrum of the Lichnerowicz Laplacian $\Delta_L$ contains the ray
$[{1/4},+\infty[$. If moreover the scalar curvature is constant then -2 and 0
are infinite dimensional eigenvalues. If, in addition, the inequality $<\Delta
u, u>_{L^2}\geq \frac14||u||^2_{L^2}$ holds for all smooth compactly supported
function $u$, then there is no other value in the spectrum.


title:
Detection of the H92alpha recombination line from the starbursts in the
  Circinus galaxy and NGC 1808

abstract:
  Context. Gas ionized by starburst activity radiates radio recombination lines
(RRLs), from which one can derive the plasma conditions and the number of
massive stars formed in the burst, free of dust obscuration effects.
  Aims. We aimed to find RRL emission from additional starburst systems and to
use the line properties to estimate the properties of the ionized gas.
  Methods. We conducted a search for RRLs in the nearby extragalactic starburst
or Seyfert galaxies NGC 1808, the Circinus galaxy, NGC 4038/9, II Zw 40, NGC
6221, NGC 7552, IRAS 18325-5926, IC 5063, and VV 114. We used the VLA and the
ATCA to search for the RRLs H91alpha and H92alpha with rest frequencies of 8.6
GHz and 8.3 GHz.
  Results. We detected for the first time RRLs from the starburst nuclei in the
Circinus galaxy and NGC 1808. The Circinus galaxy was detected with a line
strength integrated over the source of 3.2 mJy, making it the fourth-strongest
extragalactic RRL emitter known at this frequency (after NGC 4945, M 82, and
NGC 253). The line and continuum emission can be matched by a model consisting
of a collection of 50 to 10 000 H II regions with 300 to 9000 O5 stars required
to maintain the ionization, inferring a star formation rate of 0.2 Msun/yr to 6
Msun/yr. NGC 1808 was detected in RRL emission at 3.9 sigma with a line
strength of 0.47 mJy at the expected velocity.
  Conclusion. We have detected RRLs from two galaxies, adding to the small but
growing number of known extragalactic RRL emitters. The Circinus galaxy is
strong and especially suited to high-quality follow-up spectroscopic study. We
derived conditions and star formation rates in the starbursting regions.
Uncertainties can be reduced by future multi-transition studies.


title: Analyticity of QCD observables beyond leading-order perturbation theory

abstract:
  A theoretical framework is presented to treat hadronic observables within
analytic perturbative QCD beyond the leading order of the coupling and for more
than one single large momentum scale. The approach generalizes and extends the
pioneering work of Shirkov and Solovtsov on an analytic strong running
coupling. Some applications to hadronic observables at the partonic level are
also discussed.


title: General theory of decoy-state quantum cryptography with source errors

abstract:
  The existing theory of decoy-state quantum cryptography assumes the exact
control of each states from Alice's source. Such exact control is impossible in
practice. We develop the theory of decoy-state method so that it is
unconditionally secure even there are state errors of sources, if the range of
a few parameters in the states are known. This theory simplifies the practical
implementation of the decoy-state quantum key distribution because the
unconditional security can be achieved with a slightly shortened final key,
even though the small errors of pulses are not corrected.


title: Orbits and Masses in the T Tauri System

abstract:
  We investigate the binary star T Tauri South, presenting the orbital
parameters of the two components and their individual masses. We combined
astrometric positions from the literature with previously unpublished VLT
observations. Model fits yield the orbital elements of T Tau Sa and Sb. We use
T Tau N as an astrometric reference to derive an estimate for the mass ratio of
Sa and Sb. Although most of the orbital parameters are not well constrained, it
is unlikely that T Tau Sb is on a highly elliptical orbit or escaping from the
system. The total mass of T Tau S is rather well constrained to 3.0 +0.15/-0.24
M_sun. The mass ratio Sb:Sa is about 0.4, corresponding to individual masses of
M_Sa = 2.1+/-0.2 M_sun and M_Sb = 0.8+/-0.1 M_sun. This confirms that the
infrared companion in the T Tauri system is a pair of young stars obscured by
circumstellar material.


title: Higher Extension Modules and the Yoneda Product

abstract:
  A chain of c submodules E =: E_0 >= E_1 >= ... >= E_c >= E_{c+1} := 0 gives
rise to c composable 1-cocycles in Ext^1(E_{i-1}/E_i,E_i/E_{i+1}), i=1,...,c.
In this paper we follow the converse question: When are c composable 1-cocycles
induced by a module E together with a chain of submodules as above? We call
such modules c-extension modules. The case c=1 is the classical correspondence
between 1-extensions and 1-cocycles. For c=2 we prove an existence theorem
stating that a 2-extension module exists for two composable 1-cocycles eta^M_L
in Ext^1(M,L) and eta^L_N in Ext^1(L,N), if and only if their Yoneda product
eta^M_L o eta^L_N in Ext^2(M,N) vanishes. We further prove a modelling theorem
for c=2: In case the set of all such 2-extension modules is non-empty it is an
affine space modelled over the abelian group that we call the first extension
group of 1-cocycles, Ext^1(eta^M_L,eta^L_N) := Ext^1(M,N)/(Hom(M,L) o eta^L_N +
eta^M_L o Hom(L,N)).


title:
Schrodinger quantization of linearly polarized Gowdy $S^1\times S^2$ and
  $S^3$ models coupled to massless scalar fields

abstract:
  In this paper we will construct the Schrodinger representation for the
linearly polarized Gowdy $S^1\times S^2$ and $S^3$ models coupled to massless
scalar fields. Here the quantum states belong to a $L^2$-space for a suitable
quantum configuration space endowed with a Gaussian measure, whose support is
analyzed. This study completes the quantization of these systems previously
performed in the Fock scheme, and provides a specially useful framework to
address physically relevant questions.


title: Detecting entangled states in graphene via crossed Andreev reflection

abstract:
  Shot noise cross-correlations across single layer graphene structures are
calculated with insulators separating a superconducting region. A new feature
of specular crossed Andreev reflection comes into play due to the unique band
structure of graphene. This gives rise to a rich structure in the states of the
electric current flowing across the graphene sheet. We identified a parametric
regime where {\em positive} shot noise cross-correlations of the current appear
signifying entanglement. In contrast to previous proposals the sign of the
cross-correlations can be easily tuned by the application of a gate voltage.


title:
Two-Particle Momentum Correlations in Jets Produced in ppbar Collisions
  at s**(1/2) = 1.96-TeV

abstract:
  We present the first measurement of two-particle momentum correlations in
jets produced in $p\bar p$ collisions at $\sqrt{s}=1.96$ TeV. Results are
obtained for charged particles within a restricted cone with an opening angle
of 0.5 radians around the jet axis and for events with dijet masses between 66
and 563 GeV/c$^{2}$. A comparison of the experimental data to theoretical
predictions obtained for partons within the framework of resummed perturbative
QCD in the next-to-leading log approximation (NLLA) shows that the parton
momentum correlations survive the hadronization stage of jet fragmentation,
giving further support to the hypothesis of local parton-hadron duality. The
extracted value of the NLLA parton shower cutoff scale $Q_\mathit{eff}$ set
equal to $\Lambda_\mathit{QCD}$ is found to be $(1.4^{+0.9}_{-0.7})\times 100$
MeV.


title: Violation of the Cauchy-Schwarz Inequality in the Macroscopic Regime

abstract:
  We have observed a violation of the Cauchy-Schwarz inequality in the
macroscopic regime by more than 8 standard deviations. The violation has been
obtained while filtering out only the low frequency noise of the
quantum-correlated beams that results from the technical noise of the laser
used to generate them. We use bright intensity-difference squeezed beams
produced by four-wave mixing as the source of the correlated fields. We also
demonstrate that squeezing does not necessarily imply a violation of the
Cauchy-Schwarz inequality.


title: Microcavity polaritons in disordered exciton lattices

abstract:
  We investigate the interaction of excitons in a two dimensional lattice and
photons in a planar cavity in the presence of disorder. The strong
exciton-photon coupling is described in terms of polariton quasi-particles,
which are scattered by a disorder potential. We consider three kinds of
disorder: (a) inhomogeneous exciton energy, (b) inhomogeneous exciton-photon
coupling and (c) deviations from an ideal lattice. These three types of
disorder are characteristic of different physical systems, and their separate
analysis gives insight on the competition between randomness and light-matter
coupling. We consider conventional planar polariton structures (with excitons
resonant to photon modes emitting normal to the cavity) and Bragg polariton
structures, in which excitons in a lattice are resonant with photon modes at a
finite angle satisfying the Bragg condition. We calculate the absorption
spectra in the normal direction and at the Bragg angle by a direct
diagonalization of the exciton-photon Hamiltonian. We found that in some cases
weak disorder increases the light-matter coupling and leads to a larger
polariton splitting. Moreover, we found that the coupling of excitons and
photons is less sensitive to disorder of type (b) and (c). This suggests that
polaritonic structures realized with impurities in a semiconductor or with
atoms in optical lattices are good candidate for the observation of some of the
Bragg polariton features.


title: Limitations of Bayesian Evidence Applied to Cosmology

abstract:
  There has been increasing interest by cosmologists in applying Bayesian
techniques, such as Bayesian Evidence, for model selection. A typical example
is in assessing whether observational data favour a cosmological constant over
evolving dark energy. In this paper, the example of dark energy is used to
illustrate limitations in the application of Bayesian Evidence associated with
subjective judgements concerning the choice of model and priors. An analysis of
recent cosmological data shows a statistically insignificant preference for a
cosmological constant over simple dynamical models of dark energy. It is argued
that for nested problems, as considered here, Bayesian parameter estimation can
be more informative than computing Bayesian Evidence for poorly motivated
physical models.


title: Evolution of Nuclear Star Clusters

abstract:
  Two-body relaxation times of nuclear star clusters are short enough that
gravitational encounters should substantially affect their structure in 10 Gyr
or less. In nuclear star clusters without massive black holes, dynamical
evolution is a competition between core collapse, which causes densities to
increase, and heat input from the surrounding galaxy, which causes densities to
decrease. The maximum extent of a nucleus that can resist expansion is derived
numerically for a wide range of initial conditions; observed nuclei are shown
to be compact enough to resist expansion, although there may have been an
earlier generation of low-density nuclei that were dissolved. An evolutionary
model for NGC 205 is presented which suggests that the nucleus of this galaxy
has already undergone core collapse. Adding a massive black hole to a nucleus
inhibits core collapse, and nuclear star clusters with black holes always
expand, due primarily to heat input from the galaxy and secondarily to heating
from stellar disruptions. The expansion rate is smaller for larger black holes
due to the smaller temperature difference between galaxy and nucleus when the
black hole is large. The rate of stellar tidal disruptions and its variation
with time are computed for a variety of initial models. The disruption rate
generally decreases with time due to the evolving nuclear density, particularly
in the faintest galaxies, assuming that scaling relations derived for luminous
galaxies can be extended to low luminosities.


title:
Neutrality of the color-flavor-locked phase in a Dyson-Schwinger
  approach

abstract:
  The role of neutrality constraints for the phase structure of QCD at
non-vanishing chemical potentials is studied within a self-consistent
truncation scheme for the Dyson-Schwinger equation of the quark propagator in
Landau gauge. We find the (approximate) color-flavor-locked phase to be
energetically preferred at all potentially relevant densities and for physical
values of the quark masses. We furthermore observe the impossibility to define
this phase by residual global symmetries and discuss the role of chemical
potentials.


title: Black hole state degeneracy in Loop Quantum Gravity

abstract:
  The combinatorial problem of counting the black hole quantum states within
the Isolated Horizon framework in Loop Quantum Gravity is analyzed. A
qualitative understanding of the origin of the band structure shown by the
degeneracy spectrum, which is responsible for the black hole entropy
quantization, is reached. Even when motivated by simple considerations, this
picture allows to obtain analytical expressions for the most relevant
quantities associated to this effect.


title: $L^2$ extension of adjoint line bundle sections

abstract:
  We prove an $L^2$ extension theorem of Ohsawa-Takegoshi type for extending
holomorphic sections of line bundles from a subvariety which is given as a
maximal log-canonical center of a pair and is of general codimension in a
projective variety. Our method of proof indicates that such a setting is the
most natural one in a sense, for general $L^2$ extension of line bundle
sections.


title: Consistance d'un estimateur de minimum de variance \'etendue

abstract:
  We consider a generalization of the criterion minimized by the K-means
algorithm, where a neighborhood structure is used in the calculus of the
variance. Such tool is used, for example with Kohonen maps, to measure the
quality of the quantification preserving the neighborhood relationships. If we
assume that the parameter vector is in a compact Euclidean space and all it
components are separated by a minimal distance, we show the strong consistency
of the set of parameters almost realizing the minimum of the empirical extended
variance.


title: Estimation consistante de l'architecture des perceptrons multicouches

abstract:
  We consider regression models involving multilayer perceptrons (MLP) with one
hidden layer and a Gaussian noise. The estimation of the parameters of the MLP
can be done by maximizing the likelihood of the model. In this framework, it is
difficult to determine the true number of hidden units because the information
matrix of Fisher is not invertible if this number is overestimated. However, if
the parameters of the MLP are in a compact set, we prove that the minimization
of a suitable information criteria leads to consistent estimation of the true
number of hidden units.


title: Optical Tamm states in one-dimensional magnetophotonic structures

abstract:
  We demonstrate the existence of a spectrally narrow localized surface state,
the so-called optical Tamm state, at the interface between a 1D magnetophotonic
and non-magnetic photonic crystals. The state is spectrally located inside the
photonic band gaps of each of the photonic crystals comprising this
magnetophotonic structure. This state is associated with a sharp transmission
peak through the sample and is responsible for the substantial enhancement of
the Faraday rotation for the corresponding wavelength. The experimental results
are in excellent agreement with the theoretical predictions.


title:
Effects of Quark Interactions on Dynamical Chiral Symmetry Breaking by a
  Magnetic Field

abstract:
  It is shown how the strong interaction dynamics of a multi-quark Lagrangian
affects the catalysis of dynamical symmetry breaking by a constant magnetic
field in (3+1) dimensions. Attention is drawn to the local minima structure of
the theory.


title:
A Deeper Look at Student Learning of Quantum Mechanics: the Case of
  Tunneling

abstract:
  We report on a large-scale study of student learning of quantum tunneling in
4 traditional and 4 transformed modern physics courses. In the transformed
courses, which were designed to address student difficulties found in previous
research, students still struggle with many of the same issues found in other
courses. However, the reasons for these difficulties are more subtle, and many
new issues are brought to the surface. By explicitly addressing how to build
models of wave functions and energy and how to relate these models to real
physical systems, we have opened up a floodgate of deep and difficult questions
as students struggle to make sense of these models. We conclude that the
difficulties found in previous research are the tip of the iceberg, and the
real issue at the heart of student difficulties in learning quantum tunneling
is the struggle to build the complex models that are implicit in experts'
understanding but often not explicitly addressed in instruction.


title: Functionalizing graphene by embedded boron clusters

abstract:
  We present a model system that might serve as a blueprint for the controlled
layout of graphene based nanodevices. The systems consists of chains of B7
clusters implanted in a graphene matrix, where the boron clusters are not
directly connected. We show that the graphene matrix easily accepts these
alternating boron chains, and that the implanted boron components may
dramatically modify the electronic properties of graphene based nanomaterials.
This suggests a functionalization of graphene nanomaterials, where the
semiconducting properties might be supplemented by parts of the graphene matrix
itself, but the basic wiring will be provided by alternating chains of
implanted boron clusters that connect these areas.


title: Observation of two-dimensional lattice interface solitons

abstract:
  We report on the experimental observation of two-dimensional solitons at the
interface between square and hexagonal waveguide arrays. In addition to the
different symmetry of the lattices, the influence of a varying refractive index
modulation depth is investigated. Such variation strongly affects the
properties of surface solitons residing at different sides of the interface.


title: $\Upsilon\to\gamma A_1$ in the NMSSM at large tan beta

abstract:
  We investigate the effects of the radiatively-generated tan beta-enhanced
Higgs-singlet Yukawa couplings on the decay $\Upsilon\to \gamma A_1$ in the
NMSSM, where $A_1$ is the lightest CP-odd scalar. This radiative coupling is
found to dominate in the case of a highly singlet Higgs pseudoscalar. The
branching ratio for the production of such a particle is shown to be within a
few orders of magnitude of current experimental constraints across a
significant region of parameter space. This represents a potentially observable
signal for experiments at present B-factories.


title: Experimental study of isovector spin sum rules

abstract:
  We present the Bjorken integral extracted from Jefferson Lab experiment EG1b
for $0.05<Q^{2}<2.92$ GeV$^2$. The integral is fit to extract the twist-4
element $f_{2}^{p-n}$ which appears to be relatively large and negative.
Systematic studies of this higher twist analysis establish its legitimacy at
$Q^{2}$ around 1 GeV$^{2}$. We also performed an isospin decomposition of the
generalized forward spin polarizability $\gamma_{0}$. Although its isovector
part provides a reliable test of the calculation techniques of Chiral
Perturbation Theory, our data disagree with the calculations.


title: Automated Probabilistic Classification of Transients and Variables

abstract:
  There is an increasing number of large, digital, synoptic sky surveys, in
which repeated observations are obtained over large areas of the sky in
multiple epochs. Likewise, there is a growth in the number of (often automated
or robotic) follow-up facilities with varied capabilities in terms of
instruments, depth, cadence, wavelengths, etc., most of which are geared toward
some specific astrophysical phenomenon. As the number of detected transient
events grows, an automated, probabilistic classification of the detected
variables and transients becomes increasingly important, so that an optimal use
can be made of follow-up facilities, without unnecessary duplication of effort.
We describe a methodology now under development for a prototype event
classification system; it involves Bayesian and Machine Learning classifiers,
automated incorporation of feedback from follow-up observations, and
discriminated or directed follow-up requests. This type of methodology may be
essential for the massive synoptic sky surveys in the future.


title: On Katz's bound for number of elements with given trace and norm

abstract:
  In this note an improvement of the Katz's bound on the number of elements in
a finite field with given trace and norm is given. The improvement is obtained
by reducing the problem to estimating the number of rational points on certain
toric Calabi-Yau hypersurface, and then to use detailed cohomological
calculations by Rojas-Leon and the second author for such toric hypersurfaces.


title: New Physics at a Super Flavor Factory

abstract:
  The potential of a Super Flavor Factory (SFF) for searches of New Physics is
reviewed. While very high luminosity B physics is assumed to be at the core of
the program, its scope for extensive charm and tau studies are also emphasized.
The possibility to run at the Upsilon(5S) is also very briefly discussed; in
principle, this could provide very clean measurements of B_s decays. The
strength and reach of a SFF is most notably due to the possibility of examining
an impressive array of very clean observables. The angles and the sides of the
unitarity triangle can be determined with unprecedented accuracy. These serve
as a reference for New Physics (NP) sensitive decays such as B^+ ->tau^+ nu and
penguin dominated hadronic decay modes, providing tests of generic NP scenarios
with an accuracy of a few percent. Besides, very precise studies of direct and
time dependent CP asymmetries in radiative B decays and forward-backward
asymmetry studies in B-> X_s l^+ l^- and numerous null tests using B, charm and
tau decays are also likely to provide powerful insights into NP. The dramatic
increase in luminosity at a SFF will also open up entirely new avenues for
probing NP observables, e.g. by allowing sensitive studies using theoretically
clean processes such as B -> X_s nu nubar. The SFF is envisioned to be a
crucial tool for essential studies of flavor in the LHC era, and will extend
the reach of the LHC in many important ways.


title: Interaction Quench in the Hubbard model

abstract:
  Motivated by recent experiments in ultracold atomic gases that explore the
nonequilibrium dynamics of interacting quantum many-body systems, we
investigate the opposite limit of Landau's Fermi liquid paradigm: We study a
Hubbard model with a sudden interaction quench, that is the interaction is
switched on at time t=0. Using the flow equation method, we are able to study
the real time dynamics for weak interaction U in a systematic expansion and
find three clearly separated time regimes: i) An initial buildup of
correlations where the quasiparticles are formed. ii) An intermediate
quasi-steady regime resembling a zero temperature Fermi liquid with a
nonequilibrium quasiparticle distribution function. iii) The long time limit
described by a quantum Boltzmann equation leading to thermalization with a
temperature T proportional to U.


title:
Magneto-spectroscopy of Highly-Aligned Carbon Nanotubes: Identifying the
  Role of Threading Magnetic Flux

abstract:
  We have investigated excitons in highly-aligned single-walled carbon
nanotubes (SWCNTs) through optical spectroscopy at low temperature (1.5 K) and
high magnetic fields ($\textbf{\textit{B}}$) up to 55 T. SWCNT/polyacrylic acid
films were stretched, giving SWCNTs that are highly aligned along the direction
of stretch ($\hat{n}$). Utilizing two well-defined measurement geometries,
$\hat{n}\parallel\textbf{\textit{B}}$ and $\hat{n}\perp\textbf{\textit{B}}$, we
provide unambiguous evidence that the photoluminescence energy and intensity
are only sensitive to the $\textbf{\textit{B}}$-component parallel to the tube
axis. A theoretical model of one-dimensional magneto-excitons, based on
exchange-split `bright' and `dark' exciton bands with
Aharonov-Bohm-phase-dependent energies, masses, and oscillator strengths,
successfully reproduces our observations and allows determination of the
splitting between the two bands as $\sim4.8$ meV for (6,5) SWCNTs.


title: Bond chaos in the Sherrington-Kirkpatrick model

abstract:
  We calculate the probability distribution of the overlap between a spin glass
and a copy of itself in which the bonds are randomly perturbed in varying
degrees. The overlap distribution is shown to go to a delta distribution in the
thermodynamic limit for arbitrarily small perturbations (bond chaos) and we
obtain the scaling behaviour of the distribution with system size N in the high
and low temperature phases and exactly at the critical temperature. The results
are relevant for the free energy fluctuations in the Sherrington-Kirkpatrick
model.


title: CCD Photometry of Delta Scuti stars 7 Aql and 8 Aql

abstract:
  As a continuation of the study of the Delta Scuti stars 7 Aql and 8 Aql; new
CCD photometric data were acquired in 2007. We present a period analysis on
these data that confirm the dominant modes detected in each star in the
framework of the STEPHI XII campaign in 2003.


title: Damping by slow relaxing rare earth impurities in Ni80Fe20

abstract:
  Doping NiFe by heavy rare earth atoms alters the magnetic relaxation
properties of this material drastically. We show that this effect can be well
explained by the slow relaxing impurity mechanism. This process is a
consequence of the anisotropy of the on site exchange interaction between the
4f magnetic moments and the conduction band. As expected from this model the
magnitude of the damping effect scales with the anisotropy of the exchange
interaction and increases by an order of magnitude at low temperatures. In
addition our measurements allow us to determine the relaxation time of the 4f
electrons as a function of temperature.


title: How do drops evaporate?

abstract:
  We consider evaporation of pure liquid drops on a thermally conductive
substrate. Two evaporative models are considered: one that concentrates on the
liquid phase in determining evaporative flux, and the other one that centers on
the gas/vapor phase. A single governing equation for the evolution of drop
thickness, including both models, is developed. Experiments are used to
estimate relevant parameters. We show how the derived governing equation can be
used to predict which evaporation model is appropriate under considered
experimental conditions.


title: Positivity of the universal pairing in 3 dimensions

abstract:
  Associated to a closed, oriented surface S is the complex vector space with
basis the set of all compact, oriented 3-manifolds which it bounds. Gluing
along S defines a Hermitian pairing on this space with values in the complex
vector space with basis all closed, oriented 3-manifolds. The main result in
this paper is that this pairing is positive, i.e. that the result of pairing a
nonzero vector with itself is nonzero. This has bearing on the question of what
kinds of topological information can be extracted in principle from unitary 2+1
dimensional TQFTs.
  The proof involves the construction of a suitable complexity function c on
all closed 3-manifolds, satisfying a gluing axiom which we call the topological
Cauchy-Schwarz inequality, namely that c(AB) <= max(c(AA),c(BB)) for all A,B
which bound S, with equality if and only if A=B. The complexity function c
involves input from many aspects of 3-manifold topology, and in the process of
establishing its key properties we obtain a number of results of independent
interest. For example, we show that when two finite volume hyperbolic
3-manifolds are glued along an incompressible acylindrical surface, the
resulting hyperbolic 3-manifold has minimal volume only when the gluing can be
done along a totally geodesic surface; this generalizes a similar theorem for
closed hyperbolic 3-manifolds due to Agol-Storm-Thurston.


title:
A collection of sharp dilation invariant inequalities for differentiable
  functions

abstract:
  We find best constants in several dilation invariant integral inequalities
involving derivatives of functions. Some of these inequalities are new and some
were known without best constants. The contents: 1. Estimate for a quadratic
form of the gradient, 2. Weighted G{\aa}rding inequality for the biharmonic
operator, 3.Dilation invariant Hardy's inequality with remainder term, 4.
Generalized Hardy-Sobolev inequality with sharp constant, 5. Hardy's inequality
with sharp Sobolev remainder term.