title: Surface waves on a quantum plasma half-space

abstract:
  Surface modes are coupled electromagnetic/electrostatic excitations of free
electrons near the vacuum-plasma interface and can be excited on a sufficiently
dense plasma half-space. They propagate along the surface plane and decay in
either sides of the boundary. In such dense plasma models, which are of
interest in electronic signal transmission or in some astrophysical
applications, the dynamics of the electrons is certainly affected by the
quantum effects. Thus, the dispersion relation for the surface wave on a
quantum electron plasma half-space is derived by employing the quantum
hydrodynamical (QHD) and Maxwell-Poison equations. The QHD include quantum
forces involving the Fermi electron temperature and the quantum Bohm potential.
It is found that, at room temperature, the quantum effects are mainly relevant
for the electrostatic surface plasma waves in a dense gold metallic plasma.


title:
Photoemission and x-ray absorption studies of valence states in
  (Ni,Zn,Fe,Ti)$_{3}$O$_{4}$ thin films exhibiting photo-induced magnetization

abstract:
  By means of photoemission and x-ray absorption spectroscopy, we have studied
the electronic structure of (Ni,Zn,Fe,Ti)$_{3}$O$_{4}$ thin films, which
exhibits a cluster glass behavior with a spin-freezing temperature $T_f$ of
$\sim 230$ K and photo-induced magnetization (PIM) below $T_f$. The Ni and Zn
ions were found to be in the divalent states. Most of the Fe and Ti ions in the
thin films were trivalent (Fe$^{3+}$) and tetravalent (Ti$^{4+}$),
respectively. While Ti doping did not affect the valence states of the Ni and
Zn ions, a small amount of Fe$^{2+}$ ions increased with Ti concentration,
consistent with the proposed charge-transfer mechanism of PIM.


title: Results from MiniBooNE

abstract:
  The long awaited experimental results from MiniBooNE have recently been
announced. This experiment tests whether neutrino oscillations can occur at a
higher mass squared difference $\sim1 {eV}^2$ compared to well established
observations of solar and atmospheric neutrinos. The LSND experiment has
previously claimed to have observed neutrino oscillations at $\Delta m^2 \sim 1
{eV}^2$, however the results being controversial, required an independent
confirmation. The MiniBooNE results settle this controversy by observing null
oscillations at the said mass squared difference. These results have strong
implications on existence of sterile neutrinos, CPT violation and mass varying
neutrinos. We review the present status of neutrino masses and mixing in the
light of this recent result.


title: Prompt optical emission from residual collisions in GRB outflows

abstract:
  The prompt gamma-ray emission in gamma-ray bursts is believed to be produced
by internal shocks within a relativistic unsteady outflow. The recent detection
of prompt optical emission accompanying the prompt gamma-ray emission appears
to be inconsistent with this model since the out flowing plasma is expected to
be highly optically thick to optical photons. We show here that fluctuations in
flow properties on short, ~ 1 ms, time scale, which drive the gamma-ray
producing collisions at small radii, are expected to lead to "residual"
collisions at much larger radii, where the optical depth to optical photons is
low. The late residual collisions naturally account for the relatively bright
optical emission. The apparent simultaneity of gamma-ray and optical emission
is due to the highly relativistic speed with which the plasma expands. Residual
collisions may also account for the X-ray emission during the early "steep
decline" phase, where the radius is inferred to be larger than the gamma-ray
emission radius. Finally, we point out that inverse-Compton emission from
residual collisions at large radii is expected to contribute significantly to
the emission at high energy, and may therefore "smear" the pair production
spectral cut-off.


title:
Hidden time interpretation of quantum mechanics and "no protocol"
  argument

abstract:
  Previously suggested hidden time interpretation of quantum mechanics allows
to reproduce the same predictions as standard quantum mechanics provides, since
it is based on Feynman many - paths formulation of QM. While new experimental
consequences of this interpretation are under investigation, some advantages
can be enumerated. (1) The interpretation is much field theoretic - like in
classical sense, so it is local in mathematical sense, though quantum
(physical) non-locality is preserved. (2) The interpretation is based on one
type of mathematical objects, rather than two different (Hilbert space vectors
and operators). (3) The interpretation, as it was argued, overcomes the problem
of hidden variables in a radically new way, with no conflict to Bell's theorem.
Recently an important argument against hidden variables - like formulations of
quantum theory was risen - "no protocol" argument. It is argued in the paper,
that hidden time interpretation successfully overcomes this argument.


title: Sufficient conditions for the convergence of the Magnus expansion

abstract:
  Two different sufficient conditions are given for the convergence of the
Magnus expansion arising in the study of the linear differential equation $Y' =
A(t) Y$. The first one provides a bound on the convergence domain based on the
norm of the operator $A(t)$. The second condition links the convergence of the
expansion with the structure of the spectrum of $Y(t)$, thus yielding a more
precise characterization. Several examples are proposed to illustrate the main
issues involved and the information on the convergence domain provided by both
conditions.


title: Poisson approximation for search of rare words in DNA sequences

abstract:
  Using recent results on the occurrence times of a string of symbols in a
stochastic process with mixing properties, we present a new method for the
search of rare words in biological sequences generally modelled by a Markov
chain. We obtain a bound on the error between the distribution of the number of
occurrences of a word in a sequence (under a Markov model) and its Poisson
approximation. A global bound is already given by a Chen-Stein method. Our
approach, the psi-mixing method, gives local bounds. Since we only need the
error in the tails of distribution, the global uniform bound of Chen-Stein is
too large and it is a better way to consider local bounds. We search for two
thresholds on the number of occurrences from which we can regard the studied
word as an over-represented or an under-represented one. A biological role is
suggested for these over- or under-represented words. Our method gives such
thresholds for a panel of words much broader than the Chen-Stein method.
Comparing the methods, we observe a better accuracy for the psi-mixing method
for the bound of the tails of distribution. We also present the software PANOW
(available at http://stat.genopole.cnrs.fr/software/panowdir/) dedicated to the
computation of the error term and the thresholds for a studied word.


title: Decoding the Golden Code: a VLSI design

abstract:
  The recently proposed Golden code is an optimal space-time block code for 2 X
2 multiple-input multiple-output (MIMO) systems. The aim of this work is the
design of a VLSI decoder for a MIMO system coded with the Golden code. The
architecture is based on a rearrangement of the sphere decoding algorithm that
achieves maximum-likelihood (ML) decoding performance. Compared to other
approaces, the proposed solution exhibits an inherent flexibility in terms of
modulation schemes QAM modulation size and this makes our architecture
particularly suitable for adaptive modulation schemes.


title:
Nonequilibrium pairing instability in ultracold Fermi gases with
  population imbalance

abstract:
  We present detailed numerical and analytical investigations of the
nonequilibrium dynamics of spin-polarized ultracold Fermi gases following a
sudden switching-on of the atom-atom pairing coupling strength. Within a
time-dependent mean-field approach we show that on increasing the imbalance it
takes longer for pairing to develop, the period of the nonlinear oscillations
lengthens, and the maximum value of the pairing amplitude decreases. As
expected, dynamical pairing is suppressed by the increase of the imbalance.
Eventually, for a critical value of the imbalance the nonlinear oscillations do
not even develop. Finally, we point out an interesting temperature-reentrant
behavior of the exponent characterizing the initial instability.


title:
Fast magnetization in counterstreaming plasmas with temperature
  anisotropies

abstract:
  Counterstreaming plasmas exhibits an electromagnetic unstable mode of
filamentation type, which is responsible for the magnetization of plasma
system. It is shown that filamentation instability becomes significantly faster
when plasma is hotter in the streaming direction. This is relevant for
astrophysical sources, where strong magnetic fields are expected to exist and
explain the nothermal emission observed.


title: Distortion of Ultra-high-energy sky by Galactic Magnetic Field

abstract:
  We investigate the deflections of UHE protons by Galactic magnetic field(GMF)
using four conventional GMF models in order to discuss the positional
correlation between the arrival distribution of UHECRs and their sources. UHE
protons coming from the direction around the Galactic center are highly
deflected above $8^{\circ}$ by the dipole magnetic field during their
propagation in Galactic space. However, in bisymmetric spiral field models,
there are directions with the deflection angle below $1^{\circ}$. One of these
directions is toward Centaurus A, the nearest radio-loud active galactic nuclei
that is one of possible candidates of UHECR sources. On the other hand, UHE
protons arriving from the direction of the anti-Galactic center are less
deflected, especially in bisymmetric spiral field models. Thus, the northern
hemisphere, not including the Galactic center, is suitable for the studies of
correlation with sources. The dependence on model parameters is also
investigated. The deflection angles of UHE protons are dependent on the pitch
angle of the spiral field. We also investigate distortion of the supergalactic
plane by GMF. Since the distortion in the direction around Galactic center
strongly depends on the GMF model, we can obtain information on GMF around
Galactic center if Pierre Auger Observatory finds the significant positional
correlation around the supergalactic plane.


title: Hexagonal Structure of Baby Skyrmion Lattices

abstract:
  We study the zero-temperature crystalline structure of baby Skyrmions by
applying a full-field numerical minimization algorithm to baby Skyrmions placed
inside different parallelogramic unit-cells and imposing periodic boundary
conditions. We find that within this setup, the minimal energy is obtained for
the hexagonal lattice, and that in the resulting configuration the Skyrmion
splits into quarter-Skyrmions. In particular, we find that the energy in the
hexagonal case is lower than the one obtained on the well-studied rectangular
lattice, in which splitting into half-Skyrmions is observed.


title: Fluctuations of the total entropy production in stochastic systems

abstract:
  Fluctuations of the excess heat in an out of equilibrium steady state are
experimentally investigated in two stochastic systems : an electric circuit
with an imposed mean current and a harmonic oscillator driven out of
equilibrium by a periodic torque. In these two linear systems, we study excess
heat that represents the difference between the dissipated heat out of
equilibrium and the dissipated heat at equilibrium. Fluctuation theorem holds
for the excess heat in the two experimental systems for all observation times
and for all fluctuation magnitudes.


title:
Superfield approach to symmetry invariance in QED with complex scalar
  fields

abstract:
  We show that the Grassmannian independence of the super Lagrangian density,
expressed in terms of the superfields defined on a (4, 2)-dimensional
supermanifold, is a clear-cut proof for the Becchi-Rouet-Stora-Tyutin (BRST)
and anti-BRST invariance of the corresoponding four (3 + 1)-dimensional (4D)
Lagrangian density that describes the interaction between the U(1) gauge field
and the charged complex scalar fields. The above 4D field theoretical model is
considered on a (4, 2)-dimensional supermanifold parametrized by the ordinary
four spacetime variables x^\mu (with \mu = 0, 1, 2, 3) and a pair of
Grassmannian variables \theta and \bar\theta (with \theta^2 = \bar\theta^2 = 0,
\theta \bar\theta + \bar\theta \theta = 0). Geometrically, the (anti-)BRST
invariance is encoded in the translation of the super Lagrangian density along
the Grassmannian directions of the above supermanifold such that the outcome of
this shift operation is zero.


title:
Potential for measurement of the tensor magnetic polarizability of the
  deuteron in storage ring experiments

abstract:
  General formulas describing deuteron spin dynamics in storage rings with
allowance for the tensor electric and magnetic polarizabilities are derived. It
is found that an initially tensor-polarized deuteron beam can acquire a final
horizontal vector polarization of the order of 1%. This effect allows one to
measure the tensor magnetic polarizability of the deuteron in storage ring
experiments. We also confirm an existence of the effect found by Baryshevsky
and Gurinovich, hep-ph/0506135 and Baryshevsky, hep-ph/0510158; hep-ph/0603191
that the tensor magnetic polarizability of the deuteron causes the spin
rotation with two frequencies and experiences beating for polarized deuteron
beams in storage rings.


title: Local conjugacy classes for analytic torus flows

abstract:
  If a real-analytic flow on the multidimensional torus close enough to linear
has a unique rotation vector which satisfies an arithmetical condition Y, then
it is analytically conjugate to linear. We show this by proving that the orbit
under renormalization of a constant Y vector field attracts all nearby orbits
with the same rotation vector.


title:
Solving the discrepancy between the seismic and photospheric solar
  radius

abstract:
  Two methods are used to observationally determine the solar radius: One is
the observation of the intensity profile at the limb, the other one uses f-mode
frequencies to derive a 'seismic' solar radius which is then corrected to
optical depth unity. The two methods are inconsistent and lead to a difference
in the solar radius of $\sim$0.3 Mm. Because of the geometrical extention of
the solar photosphere and the increased path lengths of tangential rays the Sun
appears to be larger to an observer who measures the extent of the solar disk.
Based on radiative transfer calculations we show that this discrepancy can be
explained by the difference between the height at disk center where
$\tau_{\mathrm{5000}}=1$ ($\tau_{\mathrm{Ross}}=2/3$) and the inflection point
of the intensity profile on the limb. We calculate the intensity profile of the
limb for the MDI continuum and the continuum at 5000 {\AA} for two atmosphere
structures and compare the position of the inflection points with the radius at
$\tau_{\mathrm{5000}}=1$ ($\tau_{\mathrm{Ross}}=2/3$). The calculated
difference between the 'seismic' radius and the inflection point is $0.347\pm
0.06$ Mm with respect to $\tau_{\mathrm{5000}}=1$ and $0.333\pm 0.08$ Mm with
respect to $\tau_{\mathrm{Ross}}=2/3$. We conclude that the standard solar
radius in evolutionary models has to be lowered by $0.333\pm 0.08$ Mm and is
695.66 Mm. Furthermore, this correction reconciles inflection point
measurements and the 'seismic' radii within the uncertainty.


title: Grazing Incidence Reflection and Scattering of MeV Protons

abstract:
  Treating protons as de Broglie waves shows that up to a few MeV energies
protons experience total external reflection using the index of refraction
concept for the target earlier applied to electrons. Angular scattering
distributions can be explained by random surface scattering as known for
X-rays. Applied to the {\it{Chandra}} and {\it{XMM-Newton}} X-ray telescopes
the calculated reflection efficiencies can explain the observed degradation of
the X-ray CCDs for both missions. Some discussion about the possibility of
realizing imaging sub-MeV and MeV proton optics is presented.


title: Compact complete minimal immersions in R^3

abstract:
  In this paper we find, for any arbitrary finite topological type, a compact
Riemann surface $\mathcal{M},$ an open domain $M\subset\mathcal{M}$ with the
fixed topological type, and a conformal complete minimal immersion $X:M\to\R^3$
which can be extended to a continuous map $X:\bar{M}\to\R^3,$ such that
$X_{|\partial M}$ is an embedding and the Hausdorff dimension of $X(\partial
M)$ is $1.$
  We also prove that complete minimal surfaces are dense in the space of
minimal surfaces spanning a finite set of closed curves in $\R^3$, endowed with
the topology of the Hausdorff distance.


title: The Casimir effect as scattering problem

abstract:
  We show that Casimir-force calculations for a finite number of
non-overlapping obstacles can be mapped onto quantum-mechanical billiard-type
problems which are characterized by the scattering of a fictitious point
particle off the very same obstacles. With the help of a modified Krein trace
formula the genuine/finite part of the Casimir energy is determined as the
energy-weighted integral over the log-determinant of the multi-scattering
matrix of the analog billiard problem. The formalism is self-regulating and
inherently shows that the Casimir energy is governed by the infrared end of the
multi-scattering phase shifts or spectrum of the fluctuating field. The
calculation is exact and in principle applicable for any separation(s) between
the obstacles. In practice, it is more suited for large- to medium-range
separations. We report especially about the Casimir energy of a fluctuating
massless scalar field between two spheres or a sphere and a plate under
Dirichlet and Neumann boundary conditions. But the formalism can easily be
extended to any number of spheres and/or planes in three or arbitrary
dimensions, with a variety of boundary conditions or non-overlapping
potentials/non-ideal reflectors.


title: First-principles study of lithium-doped carbon clathrates under pressure

abstract:
  We present a theoretical study on the behavior under pressure of the two
hypothetical C$_{46}$ and Li$_8$C$_{46}$ type-I carbon clathrates in order to
bring new informations concerning their synthesis. Using \textit{ab initio}
calculations, we have explored the energetic and structural properties under
pressure of these two carbon based cage-like materials. These low-density
meta-stable phases show large negative pressure transitions compared to diamond
which represent a serious obstacle for their synthesis. However, we evidence
that a minimum energy barrier can be reached close to 40 GPa, suggesting that
the synthesis of the Li-clathrate under extreme conditions of pressure and
temperature may be possible. Electronic band structure with related density of
states behavior under pressure as well as the dependence of the active Raman
modes with pressure are also examined.


title: Drawing polytopal graphs with polymake

abstract:
  This note wants to explain how to obtain meaningful pictures of (possibly
high-dimensional) convex polytopes, triangulated manifolds, and other objects
from the realm of geometric combinatorics such as tight spans of finite metric
spaces and tropical polytopes. In all our cases we arrive at specific,
geometrically motivated, graph drawing problems. The methods displayed are
implemented in the software system polymake.


title:
The Monitor project: Rotation of low-mass stars in NGC 2362 -- testing
  the disc regulation paradigm at 5 Myr

abstract:
  We report on the results of a time-series photometric survey of NGC 2362,
carried out using the CTIO 4m Blanco telescope and Mosaic-II detector as part
of the Monitor project. Rotation periods were derived for 271 candidate cluster
members over the mass range 0.1 <~ M/Msol <~ 1.2. The rotation period
distributions show a clear mass-dependent morphology, qualitatively similar to
that in NGC 2264, as would be expected from the age of this cluster. Using
models of angular momentum evolution, we show that angular momentum losses over
the ~1-5 Myr age range appear to be needed in order to reproduce the evolution
of the slowest rotators in the sample from the ONC to NGC 2362, as found by
many previous studies. By incorporating Spitzer IRAC mid-IR measurements, we
found that 3-4 objects showing mid-IR excesses indicative of the presence of
circumstellar discs were all slow rotators, as would be expected in the disc
regulation paradigm for early pre-main sequence angular momentum evolution, but
this result is not statistically significant at present, given the extremely
limited sample size.


title:
Minimum-weight double-tree shortcutting for Metric TSP: Bounding the
  approximation ratio

abstract:
  The Metric Traveling Salesman Problem (TSP) is a classical NP-hard
optimization problem. The double-tree shortcutting method for Metric TSP yields
an exponentially-sized space of TSP tours, each of which approximates the
optimal solution within at most a factor of 2. We consider the problem of
finding among these tours the one that gives the closest approximation, i.e.\
the \emph{minimum-weight double-tree shortcutting}. Previously, we gave an
efficient algorithm for this problem, and carried out its experimental
analysis. In this paper, we address the related question of the worst-case
approximation ratio for the minimum-weight double-tree shortcutting method. In
particular, we give lower bounds on the approximation ratio in some specific
metric spaces: the ratio of 2 in the discrete shortest path metric, 1.622 in
the planar Euclidean metric, and 1.666 in the planar Minkowski metric. The
first of these lower bounds is tight; we conjecture that the other two bounds
are also tight, and in particular that the minimum-weight double-tree method
provides a 1.622-approximation for planar Euclidean TSP.


title: Constituting Atoms of a $\sigma$ Algebra via Its Generator

abstract:
  To constitute atoms of a $\sigma$ algebra is not a easy task due to the large
number of its elements. However, determining them via generators seems a
feasible and simple way since most $\sigma$ algebras are generated by their
smaller proper subsets. Precisely, under some conditions each atom of a
$\sigma$ algebra equals the intersection of the elements containing a point of
the atom in the generator. In this paper, a very weak sufficient condition for
determining atoms by the generator is presented. The condition, though not
being a necessary one, is shown to be almost the weakest one in the sense that
it can hardly be improved.


title: Biorthogonal Expansion of Non-Symmetric Jack Functions

abstract:
  We find a biorthogonal expansion of the Cayley transform of the non-symmetric
Jack functions in terms of the non-symmetric Jack polynomials, the coefficients
being Meixner-Pollaczek type polynomials. This is done by computing the
Cherednik-Opdam transform of the non-symmetric Jack polynomials multiplied by
the exponential function.


title:
Neutron star versus heavy-ion data: is the nuclear equation of state
  hard or soft?

abstract:
  Recent astrophysical observations of neutron stars and heavy-ion data are
confronted with our present understanding of the equation of state of dense
hadronic matter. Emphasis is put on the possible role of the presence of
hyperons in the interior of compact stars. We argue that data from low-mass
pulsars provide an important cross-check between high-density astrophysics and
heavy-ion physics.


title: $C^m$-theory of damped wave equations with stabilisation

abstract:
  The aim of this note is to extend the energy decay estimates from [J. Wirth,
J. Differential Equations 222 (2006) 487--514] to a broader class of
time-dependent dissipation including very fast oscillations. This is achieved
using stabilisation conditions on the coefficient in the spirit of [F.
Hirosawa, Math. Ann. 339/4 (2007) 819--839].


title:
Characterization of half-metallic L2_1-phase Co_2FeSi full-Heusler alloy
  films formed by rapid thermal annealing

abstract:
  The authors developed a preparation technique of Co_2FeSi full-Heusler alloy
films with the L2_1-ordered structure on silicon-on-insulator (SOI) substrates,
employing rapid thermal annealing (RTA). The Co_2FeSi full-Heusler alloy films
were successfully formed by RTA-induced silicidation reaction between an
ultrathin SOI (001) layer and Fe/Co layers deposited on it. The highly
(110)-oriented L2_1-phase polycrystalline full-Heusler alloy films were
obtained at the RTA temperature of 700 C. Crystallographic and magnetic
properties of the RTA-formed full-Heusler alloy films were qualitatively the
same as those of bulk full-Heusler alloy. This technique is compatible with
metal source/drain formation process in advanced CMOS technology and would be
applicable to the fabrication of the half-metallic source/drain of MOSFET type
of spin transistors.


title:
Homogenization of spectral problems in bounded domains with doubly high
  contrasts

abstract:
  Homogenization of a spectral problem in a bounded domain with a high contrast
in both stiffness and density is considered. For a special critical scaling,
two-scale asymptotic expansions for eigenvalues and eigenfunctions are
constructed. Two-scale limit equations are derived and relate to certain
non-standard self-adjoint operators. In particular they explicitly display the
first two terms in the asymptotic expansion for the eigenvalues, with a
surprising bound for the error of order \epsilon^{5/4} proved.


title: On Surfaces of Prescribed Weighted Mean Curvature

abstract:
  Utilizing a weight matrix we study surfaces of prescribed weighted mean
curvature which yield a natural generalisation to critical points of
anisotropic surface energies. We first derive a differential equation for the
normal of immersions with prescribed weighted mean curvature, generalising a
result of Clarenz and von der Mosel. Next we study graphs of prescribed
weighted mean curvature, for which a quasilinear elliptic equation is proved.
Using this equation, we can show height and boundary gradient estimates.
Finally, we solve the Dirichlet problem for graphs of prescribed weighted mean
curvature.


title:
Electron scattering in quantum wells subjected to an in-plane magnetic
  field

abstract:
  It is shown that the electron scattering by static defects, acoustic or
optical phonons in quantum wells subjected to an in-plane magnetic field is
asymmetric. The probability of scattering contains terms which are proportional
to both the electron wave vector and the magnetic field components. The terms
under study are caused by the lack of an inversion center in quantum wells due
to structure or bulk inversion asymmetry although they are of pure diamagnetic
origin. Such a magnetic field induced asymmetry of scattering can be
responsible for a number of phenomena. In particular, the asymmetry of
inelastic electron-phonon interaction leads to an electric current flow if only
the electron gas is driven out of thermal equilibrium with the crystal lattice.


title: Travelling waves for the Gross-Pitaevskii equation II

abstract:
  The purpose of this paper is to provide a rigorous mathematical proof of the
existence of travelling wave solutions to the Gross-Pitaevskii equation in
dimensions two and three. Our arguments, based on minimization under
constraints, yield a full branch of solutions, and extend earlier results,
where only a part of the branch was built. In dimension three, we also show
that there are no travelling wave solutions of small energy.


title: Copulas: compatibility and Fr\'echet classes

abstract:
  We determine under which conditions three bivariate copulas are compatible,
viz. they are the bivariate marginals of the same trivariate copula, and, then,
construct the class of these copulas. In particular, the upper and lower bounds
for this class of trivariate copulas are determined.


title:
Microscopic derivation of self-consistent equations of Anderson
  localization in a disordered medium of finite size

abstract:
  We present a microscopic derivation of self-consistent equations of Anderson
localization in a disordered medium of finite size. The derivation leads to a
renormalized, position-dependent diffusion coefficient. The position dependence
of the latter is due to the position dependence of return probability in a
bounded medium.


title: Neural Synchronization and Cryptography

abstract:
  Neural networks can synchronize by learning from each other. In the case of
discrete weights full synchronization is achieved in a finite number of steps.
Additional networks can be trained by using the inputs and outputs generated
during this process as examples. Several learning rules for both tasks are
presented and analyzed. In the case of Tree Parity Machines synchronization is
much faster than learning. Scaling laws for the number of steps needed for full
synchronization and successful learning are derived using analytical models.
They indicate that the difference between both processes can be controlled by
changing the synaptic depth. In the case of bidirectional interaction the
synchronization time increases proportional to the square of this parameter,
but it grows exponentially, if information is transmitted in one direction
only. Because of this effect neural synchronization can be used to construct a
cryptographic key-exchange protocol. Here the partners benefit from mutual
interaction, so that a passive attacker is usually unable to learn the
generated key in time. The success probabilities of different attack methods
are determined by numerical simulations and scaling laws are derived from the
data. They show that the partners can reach any desired level of security by
just increasing the synaptic depth. Then the complexity of a successful attack
grows exponentially, but there is only a polynomial increase of the effort
needed to generate a key. Further improvements of security are possible by
replacing the random inputs with queries generated by the partners.


title:
Mechanical deformation of monocytic THP-1 cells : occurrence of two
  seqential phases with differential sensitivity to metabolic inhibitors

abstract:
  Blood leukocytes can exhibit extensive morphological changes during their
passage through small capillary vessels. The human monocytic THP-1 cell line
was used to explore the metabolic dependence of these shape changes. Cells were
aspirated into micropipettes for determination of the rate of protrusion
formation. They were then released and the kinetics of morphological recovery
was studied. Results were consistent with Evans' model (Blood, 64 : 1028, 1984)
of a viscous liquid droplet surrounded by a tensile membrane. The estimated
values of cytoplasmic viscosity and membrane tension were 162 Pa.s and 0.0142
millinewton/m respectively. The influence of metabolic inhibitors on cell
mechanical behaviour was then studied : results strongly suggested that
deformation involved two sequential phases. The cell elongation rate measured
during the first 30 seconds following the onset of aspiration was unaffected by
azide, an inhibitor of energy production, and it was about doubled by
cytochalasin D, a microfilament inhibitor, and colchicine, a microtubule
inhibitor. However, during the following two minutes, deformation was almost
abolished in cells treated with azide and cytochalasin D, whereas the
protrusion of control cells exhibited about threefold length increase. It is
concluded that, although cells seemed to deform as passive objects, active
metabolic processes were required to allow extensive morphological changes
triggered by external forces.


title: Adjacency preserving mappings on real symmetric matrices

abstract:
  Let $S_{n}$ denote the space of all $n \times n$ real symmetric matrices. For
n=2 or n>2 we characterize maps F from $S_{n}$ to $S_{m}$ which preserve
adjacency, i.e. if rank(A-B)=1, then rank(F(A)-F(B))=1.


title: Superlattice Structures of Graphene based Nanoribbons

abstract:
  Based on first-principles calculations we predict that periodically repeated
junctions of armchair graphene nanoribbons of different widths form
superlattice structures. In these superlattice heterostructures the width and
the energy gap are modulated in real space and specific states are confined in
certain segments. Orientation of constituent nanoribbons, their width and
length, the symmetry of the junction are the structural parameters to engineer
electronic properties of these quantum structures. Not only the size
modulation, but also composition modulation, such as periodically repeated,
commensurate heterojunctions of BN and graphene honeycomb nanoribbons result in
a multiple quantum well structure. We showed that these graphene based quantum
structures can introduce novel concepts to design nanodevices.


title: The QCD spin chain S matrix

abstract:
  Beisert et al. have identified an integrable SU(2,2) quantum spin chain which
gives the one-loop anomalous dimensions of certain operators in large N QCD. We
derive a set of nonlinear integral equations (NLIEs) for this model, and
compute the scattering matrix of the various (in particular, magnon)
excitations.


title: The magnetron instability in a pulsar's cylindrical electrosphere

abstract:
  (abridged) The physics of the pulsar magnetosphere remains poorly constrained
by observations. Little is known about their emission mechanism. Large vacuum
gaps probably exist, and a non-neutral plasma partially fills the neutron star
surroundings to form an electrosphere. We showed that the differentially
rotating equatorial disk in the pulsar's electrosphere is diocotron unstable
and that it tends to stabilise when relativistic effects are included. However,
when approaching the light cylinder, particle inertia becomes significant and
the electric drift approximation is violated. In this paper, we study the most
general instability, i.e. by including particle inertia effects, as well as
relativistic motions. This general non-neutral plasma instability is called the
magnetron instability. We linearise the coupled relativistic cold-fluid and
Maxwell equations. The non-linear eigenvalue problem for the perturbed
azimuthal electric field component is solved numerically. The spectrum of the
magnetron instability in a non-neutral plasma column confined between two
cylindrically conducting walls is computed for several cylindrical
configurations. For a pulsar electrosphere, no outer wall exists. In this case,
we allow for electromagnetic wave emission propagating to infinity. When the
self-field induced by the plasma becomes significant, it can first increase the
growth rate of the magnetron instability. However, equilibrium solutions are
only possible when the self-electric field, measured by the parameter $s_{\rm
e}$ and tending to disrupt the plasma configuration, is bounded to an upper
limit, $s_{\rm e,max}$. For $s_{\rm e}$ close to but smaller than this value
$s_{\rm e,max}$, the instability becomes weaker or can be suppressed as was the
case in the diocotron regime.


title: Diffuse interstellar medium and the formation of molecular clouds

abstract:
  (Abridged) The formation of molecular clouds (MCs) from the diffuse
interstellar gas appears to be a necessary step for star formation, as young
stars invariably occur within them. However, the mechanisms controlling the
formation of MCs remain controversial. In this contribution, we focus on their
formation in compressive flows driven by interstellar turbulence and
large-scale gravitational instability. Turbulent compression driven by
supernovae appears insufficient to explain the bulk of cloud and star
formation. Rather, gravity must be important at all scales, driving the
compressive flows that form both clouds and cores. Cooling and thermal
instability allow the formation of dense gas out of moderate, transonic
compressions in the warm diffuse gas, and drive turbulence into the dense
clouds. MCs may be produced by an overshoot beyond the thermal-pressure
equilibrium between the cold and warm phases of atomic gas, caused by some
combination of the ram pressure of compression and the self-gravity of the
compressed gas. In this case, properties of the clouds such as their mass,
mass-to-magnetic flux ratio, and total kinetic and gravitational energies are
in general time-variable quantities. MCs may never enter a quasi-equilibrium or
virial equilibrium state but rather continuously collapse to stars.


title:
Derivation of the postulates of quantum mechanics from the first
  principles of scale relativity

abstract:
  Quantum mechanics is based on a series of postulates which lead to a very
good description of the microphysical realm but which have, up to now, not been
derived from first principles. In the present work, we suggest such a
derivation in the framework of the theory of scale relativity. After having
analyzed the actual status of the various postulates, rules and principles that
underlie the present axiomatic foundation of quantum mechanics (in terms of
main postulates, secondary rules and derived `principles'), we attempt to
provide the reader with an exhaustive view of the matter, by both gathering
here results which are already available in the literature, and deriving new
ones which complete the postulate list.


title: Ornstein-Uhlenbeck Processes on Lie Groups

abstract:
  We consider Ornstein-Uhlenbeck processes (OU-processes) associated to
hypoelliptic diffusion processes on finite-dimensional Lie groups: let $
\mathcal{L} $ be a hypoelliptic, left-invariant ``sum of the squares''-operator
on a Lie group $ G $ with associated Markov process $ X $, then we construct
OU-processes by adding negative horizontal gradient drifts of functions $ U $.
In the natural case $ U(x) = - \log p(1,x) $, where $ p(1,x) $ is the density
of the law of $ X $ starting at identity $ e $ at time $ t =1 $ with respect to
the right-invariant Haar measure on $G$, we show the Poincar\'e inequality by
applying the Driver-Melcher inequality for ``sum of the squares'' operators on
Lie groups. The resulting Markov process is called the natural OU-process
associated to the hypoelliptic diffusion on $ G $.
  We prove the global strong existence of these OU-type processes on $ G $
under an integrability assumption on $U$. The Poincar\'e inequality for a large
class of potentials $U$ is then shown by a perturbation technique. These
results are applied to obtain a hypoelliptic equivalent of standard results on
cooling schedules for simulated annealing on compact homogeneous spaces $M$.


title: Tidal Love numbers of neutron stars

abstract:
  For a variety of fully relativistic polytropic neutron star models we
calculate the star's tidal Love number k2. Most realistic equations of state
for neutron stars can be approximated as a polytrope with an effective index
n~0.5-1.0. The equilibrium stellar model is obtained by numerical integration
of the Tolman-Oppenheimer-Volkhov equations. We calculate the linear l=2 static
perturbations to the Schwarzschild spacetime following the method of Thorne and
Campolattaro. Combining the perturbed Einstein equations into a single second
order differential equation for the perturbation to the metric coefficient
g_tt, and matching the exterior solution to the asymptotic expansion of the
metric in the star's local asymptotic rest frame gives the Love number. Our
results agree well with the Newtonian results in the weak field limit. The
fully relativistic values differ from the Newtonian values by up to ~24%. The
Love number is potentially measurable in gravitational wave signals from
inspiralling binary neutron stars.


title: Dynamical response function of the disordered kinetic Ising model

abstract:
  Recently Baumann et al. [arXiv:0709.3228v1] studied the phase-ordering
kinetics of the two-dimensional Ising model with uniform spatially quenched
disorder by Monte-Carlo simulations. They found that the two-time response and
correlation functions are in agreement with the predictions of local scale
invariance generalised to z!=2. The present paper shows why this is not true
and suggests an alternative approach which leads to a much better agreement
with the numerical results.


title:
Comment on PRL 99,140402 (2007) "Excitations in a nonequilibrium Bose
  Einstein Condensate of Exciton-polaritons" by M. Wouters and I. Carusotto

abstract: This comment has been withdrawn by the authors due to crucial error.


title:
Effects of the particle-particle channel on properties of low-lying
  vibrational states

abstract:
  Making use of the finite rank separable approach for the quasiparticle random
phase approximation enables one to perform nuclear structure calculations in
very large two-quasiparticle spaces. The approach is extended to take into
account the residual particle-particle interaction. The calculations are
performed by using Skyrme interactions in the particle-hole channel and
density-dependent zero-range interactions in the particle-particle channel. To
illustrate our approach, we study the properties of the lowest quadrupole
states in the even-even nuclei $^{128}$Pd, $^{130}$Cd, $^{124-134}$Sn,
$^{128-136}$Te and $^{136}$Xe.


title: Wormhole geometries with conformal motions

abstract:
  Exact solutions of traversable wormholes were recently found under the
assumption of spherical symmetry and the existence of a non-static conformal
symmetry. In this paper, we verify that in the case of the conformally
symmetric spacetimes with a non-static vector field generating the symmetry,
the conformal factor $\psi$ can be physically interpreted in terms of a
measurable quantity, namely, the tangential velocity of a massive test particle
moving in a stable circular orbit in the spacetime. Physical properties of the
rotational velocity of test particles and of the redshift of radiation emitted
by ultra-relativistic particles rotating around these hypothetical general
relativistic objects are further discussed. Finally, specific characteristics
and properties of gravitational bremsstrahlung emitted by charged particles in
geodesic motion in conformally symmetric wormhole geometries are also explored.


title:
Ab initio Calculations of the Interface States of
  Polyacetylene-Polyvinylfluoride and Polyethylene - Polyvinylfluoride
  Quasi-one-dimensional Chains

abstract:
  The interface states appearing in polyacetylene-polyvinylfluoride and
polyethylene-polyvinylfluoride are determined via an ab initio self consistent
field technique based on Green matrix formalism. Different properties of these
states are explored. Contrary to the results of the second pair, the results of
the first pair showed that the active electronic structure of polyacetylene
leads to new states lying in the energy gap of polyvinylfluoride which enhances
the doping probability in the first pair. The results emphasize the appearance
of bending band phenomenon as a result of the interface of systems considered.


title: Circuits, Attractors and Reachability in Mixed-K Kauffman Networks

abstract:
  The growth in number and nature of dynamical attractors in Kauffman NK
network models are still not well understood properties of these important
random boolean networks. Structural circuits in the underpinning graph give
insights into the number and length distribution of attractors in the NK model.
We use a fast direct circuit enumeration algorithm to study the NK model and
determine the growth behaviour of structural circuits. This leads to an
explanation and lower bound on the growth properties and the number of
attractor loops and a possible K-relationship for circuit number growth with
network size N. We also introduce a mixed-K model that allows us to explore <K>
between pairs of integer K values in Kauffman-like systems. We find that the
circuits' behaviour is a useful metric in identifying phase transitional
behaviour around the critical connectivity in that model too. We identify an
intermediate phase transition in circuit growth behaviour at K_S approximately
1.5, that is distinct from both the percolation transition at K_P = 1 and the
Kauffman transition at K_C = 2. We relate this transition to mutual node
reachability within the giant component of nodes.


title: Dynamic structure factor of a stiff polymer in a glassy solution

abstract:
  We provide a comprehensive overview of the current theoretical understanding
of the dynamic structure factor of stiff polymers in semidilute solution based
on the wormlike chain (WLC) model. We extend previous work by computing exact
numerical coefficients and an expression for the dynamic mean square
displacement (MSD) of a free polymer and compare various common approximations
for the hydrodynamic interactions, which need to be treated accurately if one
wants to extract quantitative estimates for model parameters from experimental
data. A recent controversy about the initial slope of the dynamic structure
factor is thereby resolved. To account for the interactions of the polymer with
a surrounding (sticky) polymer solution, we analyze an extension of the WLC
model, the glassy wormlike chain (GWLC), which predicts near power-law and
logarithmic long-time tails in the dynamic structure factor.


title: Embedding Dark Energy in Supergravity

abstract:
  We give a brief overview of some of the constraints on the embedding of dark
energy in supergravity.


title: Infall of substructures onto a Milky Way-like dark halo

abstract:
  We analyse the dynamical properties of substructures in a high-resolution
dark matter simulation of the formation of a Milky Way-like halo in a
$\Lambda$CDM cosmology. Our goal is to shed light on the dynamical
peculiarities of the Milky Way satellites. Our simulations show that about 1/3
of the subhalos have been accreted in groups. We quantify this clustering by
measuring the alignment of the angular momentum of subhalos in a group. We find
that this signal is visible even for objects accreted up to $z \sim 1$, i.e. 8
Gyr ago, and long after the spatial coherence of the groups has been lost due
the host tidal field. This group infall may well explain the ghostly streams
proposed by Lynden-Bell & Lynden-Bell to orbit the Milky Way. Our analyses also
show that if most satellites originate in a few groups, the disk-like
distribution of the Milky Way satellites would be almost inevitable. This
non-random assignment of satellites to subhalos implies an environmental
dependence on whether these low-mass objects are able to form stars, possibly
related to the nature of reionization in the early Universe. With this picture,
both the ``ghostly streams'' and the ``disk-like configuration'' are
manifestations of the same phenomenon: the hierarchical growth of structure
down to the smallest scales.


title: Topology of Neutral Hydrogen Within the Small Magellanic Cloud

abstract:
  In this paper, genus statistics have been applied to an HI column density map
of the Small Magellanic Cloud in order to study its topology. To learn how
topology changes with the scale of the system, we provide the study of topology
for column density maps at varying resolution. To evaluate the statistical
error of the genus we randomly reassign the phases of the Fourier modes while
keeping the amplitudes. We find, that at the smallest scales studied ($40
{pc}\leq\lambda\leq 80 {pc}$) the genus shift is in all regions negative,
implying a clump topology. At the larger scales ($110 {pc}\leq\lambda\leq 250
{pc}$) the topology shift is detected to be negative in 4 cases and positive
(``swiss cheese'' topology) in 2 cases. In 4 regions there is no statistically
significant topology shift at large scales.


title: Identification of photon-tagged jets in the ALICE experiment

abstract:
  The ALICE experiment at LHC will detect and identify prompt photons and light
neutral-mesons with the PHOS detector and the additional EMCal electromagnetic
calorimeter. Charged particles will be detected and identified by the central
tracking system. In this article, the possibility of studying the interaction
of jets with the nuclear medium, using prompt photons as a tool to tag jets, is
investigated by simulations. New methods to identify prompt photon-jet events
and to distinguish them from the jet-jet background are presented.


title: Two body systems from sl(2,C)-tops

abstract:
  It is shown that sl(2,$\mathbb{C}$) Euler-Arnold tops are equivalent to the
two-body systems of Calogero-Moser type. We prove that generic Hamiltonians of
sl(2,$\mathbb{C}$) tops are equivalent to one of three canonical Hamiltonians.
For all canonical Hamiltonians the corresponding two-body system is found.
Bosonisation formulas for each case are obtained explicitly. Relations with
Antonov-Zabrodin-Hasegawa R-matrix are discussed.


title:
Two-Dimensional Electron Gas with Cold Atoms in Non-Abelian Gauge
  Potentials

abstract:
  Motivated by the possibility of creating non-Abelian fields using cold atoms
in optical lattices, we explore the richness and complexity of non-interacting
two-dimensional electron gases (2DEGs) in a lattice, subjected to such fields.
In the continuum limit, a non-Abelian system characterized by a two-component
"magnetic flux" describes a harmonic oscillator existing in two different
charge states (mimicking a particle-hole pair) where the coupling between the
states is determined by the non-Abelian parameter, namely the difference
between the two components of the "magnetic flux." A key feature of the
non-Abelian system is a splitting of the Landau energy levels, which broaden
into bands, as the spectrum depends explicitly on the transverse momentum.
These Landau bands result in a coarse-grained "moth," a continuum version of
the generalized Hofstadter butterfly. Furthermore, the bands overlap, leading
to effective relativistic effects. Importantly, similar features also
characterize the corresponding two-dimensional lattice problem when at least
one of the components of the magnetic flux is an irrational number. The lattice
system with two competing "magnetic fluxes" penetrating the unit cell provides
a rich environment in which to study localization phenomena. Some unique
aspects of the transport properties of the non-Abelian system are the
possibility of inducing localization by varying the quasimomentum, and the
absence of localization of certain zero-energy states exhibiting a linear
energy-momentum relation. Furthermore, non-Abelian systems provide an
interesting localization scenario where the localization transition is
accompanied by a transition from relativistic to non-relativistic theory.


title: Variable importance in binary regression trees and forests

abstract:
  We characterize and study variable importance (VIMP) and pairwise variable
associations in binary regression trees. A key component involves the node mean
squared error for a quantity we refer to as a maximal subtree. The theory
naturally extends from single trees to ensembles of trees and applies to
methods like random forests. This is useful because while importance values
from random forests are used to screen variables, for example they are used to
filter high throughput genomic data in Bioinformatics, very little theory
exists about their properties.


title: Some Geometry of Nodal Curves

abstract:
  We find a geometrical method of analysing the singularities of a plane nodal
curve. The main results will be used in a forthcoming paper on geometric
Plucker formulas for such curves. Plane nodal curves, that is plane curves
having at most nodes as singularities, form an important class of curves, as
any projective algebraic curve is birational to a plane nodal curve.


title: Nonlinear Dynamics in Double Square Well Potential

abstract:
  Considering the coherent nonlinear dynamics in double square well potential
we find the example of coexistence of Josephson oscillations with a
self-trapping regime. This macroscopic bistability is explained by proving
analytically the simultaneous existence of symmetric, antisymmetric and
asymmetric stationary solutions of the associated Gross-Pitaevskii equation.
The effect is illustrated and confirmed by numerical simulations. This property
allows to make suggestions on possible experiments using Bose-Einstein
condensates in engineered optical lattices or weakly coupled optical waveguide
arrays.

categories: nlin.PS cond-mat.other math-ph math.MP physics.atom-ph


title:
Reply to "Comment on 'Precision measurement of the Casimir-Lifshitz
  force in a fluid'"

abstract:
  We have reviewed the Comment of Geyer et al. [arXiv:0708.1548] concerning our
recent work [Phys. Rev. A 75, 060102 (R) (2007)], and while we disagree with
their criticisms, we acknowledge them for giving us the opportunity to add
interesting addition material and a more detailed description of our
experiment. We describe further our calculation and explain why a more
sophisticated model is not warranted. We also present detailed experiments on
the effects of electrostatic forces in our measurements and show that the
contribution due to work function differences is small and that the residual
electrostatic force is dominated by trapped charges and external fields.
Finally, we estimate the effect of double layer interactions. These additional
calculations and measurements support our original conclusion that the
experimental results are consistent with the Lifshitz theory.


title:
3D chaotic model for sub-grid turbulent dispersion in Large Eddy
  Simulations

abstract:
  We introduce a 3D multiscale kinematic velocity field as a model to simulate
Lagrangian turbulent dispersion. The incompressible velocity field is a
nonlinear deterministic function, periodic in space and time, that generates
chaotic mixing of Lagrangian trajectories. Relative dispersion properties, e.g.
the Richardson's law, are correctly reproduced under two basic conditions: 1)
the velocity amplitudes of the spatial modes must be related to the
corresponding wavelengths through the Kolmogorov scaling; 2) the problem of the
lack of "sweeping effect" of the small eddies by the large eddies, common to
kinematic simulations, has to be taken into account. We show that, as far as
Lagrangian dispersion is concerned, our model can be successfully applied as
additional sub-grid contribution for Large Eddy Simulations of the planetary
boundary layer flow.


title:
Tripled composite fermion liquid in generalized Pfaffian of v=5/2 and
  non-abelian anyonic quasiholes with k=3

abstract:
  This paper has been withdrawn by the author, due to an important sign error
in Eqn. 2.


title: Uniqueness and factorization of Coleff-Herrera currents

abstract:
  We prove a uniqueness result for Coleff-Herrera currents which in particular
means that if $f=(f_1,..., f_m)$ defines a complete intersection, then the
classical Coleff-Herrera product associated to $f$ is the unique Coleff-Herrera
current that is cohomologous to 1 with respect to the operator
$\delta_f-\dbar$, where $\delta_f$ is interior multiplication with $f$. From
the uniqueness result we deduce that any Coleff-Herrera current on a variety
$Z$ is a finite sum of products of residue currents with support on $Z$ and
holomorphic forms.


title: Open Inflationary Universes in Gauss-Bonnet Brane Cosmology

abstract:
  In this article, we study a type of one-field approach for open inflationary
universe scenario in the context of braneworld models with a Gauss-Bonnet
correction term. For a one-bubble universe model, we determine and characterize
the existence of the Coleman-De Lucia instanton together with the period of
inflation after tunneling has occurred. Our results are compared those
analogous obtained when the usual Einstein Theory of Gravitation is used.


title: Are networks with more edges easier to synchronize?

abstract:
  In this paper, the relationship between the network synchronizability and the
edge distribution of its associated graph is investigated. First, it is shown
that adding one edge to a cycle definitely decreases the network
sychronizability. Then, since sometimes the synchronizability can be enhanced
by changing the network structure, the question of whether the networks with
more edges are easier to synchronize is addressed. It is shown by examples that
the answer is negative. This reveals that generally there are redundant edges
in a network, which not only make no contributions to synchronization but
actually may reduce the synchronizability. Moreover, an example shows that the
node betweenness centrality is not always a good indicator for the network
synchronizability. Finally, some more examples are presented to illustrate how
the network synchronizability varies following the addition of edges, where all
the examples show that the network synchronizability globally increases but
locally fluctuates as the number of added edges increases.


title: A note on polylogarithms on curves and abelian schemes

abstract:
  In this note we investigate the connection between polylogarithms on curves
and abelian schemes. The main result shows that the polylogarithm on the
abelian scheme can be obtained as the push-forward of the polylogarithm on a
suitable sub-curve. If the abelian scheme is the Jacobian of a smooth
projective curve, this push-forward can also be written as a cup-product with
the fundamental class of the curve.


title: Proof nets for display logic

abstract:
  This paper explores several extensions of proof nets for the Lambek calculus
in order to handle the different connectives of display logic in a natural way.
The new proof net calculus handles some recent additions to the Lambek
vocabulary such as Galois connections and Grishin interactions. It concludes
with an exploration of the generative capacity of the Lambek-Grishin calculus,
presenting an embedding of lexicalized tree adjoining grammars into the
Lambek-Grishin calculus.


title: An introduction to quantum gravity

abstract:
  After an overview of the physical motivations for studying quantum gravity,
we reprint THE FORMAL STRUCTURE OF QUANTUM GRAVITY, i.e. the 1978 Cargese
Lectures by Professor B.S. DeWitt, with kind permission of Springer. The reader
is therefore introduced, in a pedagogical way, to the functional integral
quantization of gravitation and Yang-Mills theory. It is hoped that such a
paper will remain useful for all lecturers or Ph.D. students who face the task
of introducing (resp. learning) some basic concepts in quantum gravity in a
relatively short time. In the second part, we outline selected topics such as
the braneworld picture with the same covariant formalism of the first part, and
spectral asymptotics of Euclidean quantum gravity with diffeomorphism-invariant
boundary conditions. The latter might have implications for singularity
avoidance in quantum cosmology.


title: Wave packet methods in cavity QED

abstract:
  The Jaynes-Cummings model, with and without the rotating wave approximation,
is expressed in the conjugate variable representation and solved numerically by
wave packet propagation. Both cases are then cast into systems of two coupled
harmonic oscillators, reminiscent of coupled bound electronic potential curves
of diatomic molecules. Using the knowledge of such models, this approach of the
problem gives new insight of the dynamics. The effect of the rotating wave
approximation is discussed. The collapse-revival phenomenon is especially
analyzed in a non-standard manner. Extensions of the method is briefly
mentioned in terms of a three-level atom and the Dicke model.


title: Production of hypernuclei with hadronic and electromagnetic probes

abstract:
  We present an overview of a fully covariant formulation of describing the
hypernuclear production with hadronic and electromagnetic probes. This theory
is based on an effective Lagrangian picture and it focuses on production
amplitudes that are described via creation, propagation and decay into relevant
channel of N*(1650), N*(1710) and N*(1720) intermediate baryonic resonance
states in the initial collision of the projectile with one of the target
nucleons. The bound state nucleon and hyperon wave functions are obtained by
solving the Dirac equation with appropriate scalar and vector potentials.
Specific examples are discussed for reactions which are of interest to current
and future experiments on the hypernuclear production.


title: Characteristic temperatures and spectral appearance of ULX disks

abstract:
  A standard disk around an accreting black hole may become effectively
optically-thin and scattering dominated in the inner region, for high accretion
rates (as already predicted by the Shakura-Sunyaev model). Radiative emission
from that region is less efficient than blackbody emission, leading to an
increase of the colour temperature in the inner region, by an order of
magnitude above the effective temperature. We show that the integrated spectrum
has a power-law-like shape in the ~ 1-5 keV band, with a soft excess at lower
energies and a downward curvature or break at higher energies, in agreement
with the observed spectra of many ultraluminous X-ray sources.


title: The X-ray spectrum of RX J1914.4+2456 revisited

abstract:
  It has been proposed that RX J1914.4+2456 is a stellar binary system with an
orbital period of 9.5 mins. As such it shares many similar properties with RX
J0806.3+1527 (5.4 mins). However, while the X-ray spectrum of RX J0806.3+1527
can be modelled using a simple absorbed blackbody, the X-ray spectrum of RX
J1914.4+2456 has proved difficult to fit using a physically plausible model. In
this paper we re-examine the available X-ray spectra of RX J1914.4+2456 taken
using XMM-Newton. We find that the X-ray spectra can be fitted using a simple
blackbody and an absorption component which has a significant enhancement of
neon compared to the solar value. We propose that the material in the
inter-binary system is significantly enhanced with neon. This makes its
intrinsic X-ray spectrum virtually identical to RX J0806.3+1527. We re-access
the X-ray luminosity of RX J1914.4+2456 and the implications of these results.


title: Testing Primordial Abundances With Sterile Neutrinos

abstract:
  The mixing between sterile and active neutrinos is taken into account in the
calculation of Big Bang Nucleosynthesis. The abundances of primordial elements,
like D, 3He, 4He and 7Li, are calculated by including sterile neutrinos, and by
using finite chemical potentials. It is found that the resulting theoretical
abundances are consistent with WMAP data on baryonic densities, and with limits
of LSND on mixing angles, only if 7Li is excluded from the statistical analysis
of theoretical and experimental results.


title: D-branes at Singularities and String Phenomenology

abstract:
  In these notes we give an introduction to some of the concepts involved in
constructing SM-like gauge theories in systems of branes at singularities of CY
manifolds. These notes are an expanded version of lectures given by Herman
Verlinde at the Cargese 2006 Summer School.


title: The Yang-Mills Vacuum in Coulomb Gauge in D=2+1 Dimensions

abstract:
  The variational approach to the Hamilton formulation of Yang-Mills theory in
Coulomb gauge developed by the present authors previously is applied to
Yang-Mills theory in 2+1 dimensions and is confronted with the existing lattice
data. We show that the resulting Dyson-Schwinger equations (DSE) yield
consistent solutions in 2+1 dimensions only for infrared divergent ghost form
factor and gluon energy. The obtained numerical solutions of the DSE reproduce
the analytic infrared results and are in satisfactory agreement with the
existing lattice date in the whole momentum range.


abstract:
  The article `Global regularity for the 3D Navier-Stokes and the 3D Euler
equations'(arXiv:0711.2453) is withdrawn due to a serious error in the proof.


title: Ladder Operators for q-orthogonal Polynomials

abstract:
  The q-difference analog of the classical ladder operators is derived for
those orthogonal polynomials arising from a class of indeterminate moments
problem.


title: Physical boundary state for the quantum tetrahedron

abstract:
  We consider stability under evolution as a criterion to select a physical
boundary state for the spinfoam formalism. As an example, we apply it to the
simplest spinfoam defined by a single quantum tetrahedron and solve the
associated eigenvalue problem at leading order in the large spin limit. We show
that this fixes uniquely the free parameters entering the boundary state.
Remarkably, the state obtained this way gives a correlation between edges which
runs at leading order with the inverse distance between the edges, in agreement
with the linearized continuum theory. Finally, we give an argument why this
correlator represents the propagation of a pure gauge, consistently with the
absence of physical degrees of freedom in 3d general relativity.


title: Cool X-ray emitting gas in the core of the Centaurus cluster of galaxies

abstract:
  We use a deep XMM-Newton Reflection Grating Spectrometer observation to
examine the X-ray emission from the core of the Centaurus cluster of galaxies.
We clearly detect Fe-XVII emission at four separate wavelengths, indicating the
presence of cool X-ray emitting gas in the core of the cluster. Fe ions from
Fe-XVII to XXIV are observed. The ratio of the Fe-XVII 17.1A lines to 15.0A
line and limits on O-VII emission indicate a lowest detected temperature in the
emitting region of 0.3 to 0.45 keV (3.5 to 5.2x10^6 K). The cluster also
exhibits strong N-VII emission, making it apparent that the N abundance is
supersolar in its very central regions. Comparison of the strength of the
Fe-XVII lines with a Solar metallicity cooling flow model in the inner 17 kpc
radius gives mass deposition rates in the absence of heating of 1.6-3 Msun/yr.
Spectral fitting implies an upper limit of 0.8 Msun/yr below 0.4 keV, 4 Msun/yr
below 0.8 keV and 8 Msun/yr below 1.6 keV. The cluster contains X-ray emitting
gas over at least the range of 0.35 to 3.7 keV, a factor of more than 10 in
temperature. We find that the best fitting metallicity of the cooler components
is smaller than the hotter ones, confirming that the apparent metallicity does
decline within the inner 1 arcmin radius.


title: M-Dwarfs at Large Heliocentric Distances

abstract:
  We present an analysis of the faint M star population seen as foreground
contaminants in deep extragalactic surveys. We use space-based data to separate
such stars from high redshift galaxies in a publically-available dataset, and
consider the photometric properties of the resulting sample in the optical and
infrared. The inferred distances place these stars well beyond the scale height
of the thick disk. We find strong similarities between this faint sample
(reaching i'_{AB}=25) and the brighter disk M dwarf population studied by other
authors. The optical-infrared properties of the bulk of our sources spanning
6000A-4.5microns are consistent with those 5-10 magnitudes brighter. We also
present deep spectroscopy of faint M dwarf stars reaching continuum limits of
i'_{AB}~26, and measure absorption line strengths in the CaH2 and TiO5 bands.
Both photometrically and spectroscopically, our sources are consistent with
metallicities as low as a tenth solar: metal-rich compared with halo stars at
similar heliocentric distances. We comment on the possible MACHO identification
of M stars at faint magnitudes.


title: The environs of the HII region Gum31

abstract:
  We analyze the distribution of the interstellar matter in the environs of the
HII region Gum31, excited by the open cluster NGC3324, located in the complex
Carina region, with the aim of investigating the action of the massive stars on
the surrounding neutral material. We use neutral hydrogen 21-cm line data,
radio continuum images at 0.843, 2.4 and 4.9 GHz, 12CO(1-0) observations, and
IRAS and MSX infrared data. Adopting a distance of 3 kpc for the HII region and
the ionizing cluster, we derived an electron density of 33+/-3 cm^-3 and an
ionized mass of (3.3+/-1.1)x10^3 Mo based on the radio continuum data at 4.9
GHz. The HI 21-cm line images revealed an HI shell surrounding the HII region.
The HI structure is 10.0+/-1.7 pc in radius, has a neutral mass of 1500+/-500
Mo, and is expanding at 11 km/s. The associated molecular gas amounts to
1.1+/-0.5)x10^5 Mo, being its volume density of about 350 cm^3. This molecular
shell could represent the remains of the cloud where the young open cluster
NGC3324 was born or could have originated by the shock front associated with
the HII region. The difference between the ambient density and the electron
density of the HII region suggests that the HII region is expanding. The
distributions of the ionized and molecular material, along with that of the
emission in the MSX band A, suggest that a photodissociation region has
developed at the interface between the ionized and molecular gas. The
characteristics of a relatively large number of the IRAS, MSX, and 2MASS point
sources projected onto the molecular envelope are compatible with protostellar
candidates, showing the presence of active star forming regions. Very probably,
the expansion of the HII region has triggered stellar formation in the
molecular shell.


title:
17O NMR study of the intrinsic magnetic susceptibility and spin dynamics
  of the quantum kagome antiferromagnet ZnCu3(OH)6Cl2

abstract:
  We report through 17O NMR, an unambiguous local determination of the
intrinsic kagome lattice spin susceptibility as well as that created around
non-magnetic defects issued from natural Zn/ Cu exchange in the S=1/2 (Cu2+)
herbertsmithite ZnCu3(OH)6Cl2 compound. The issue of a singlet-triplet gap is
addressed. The magnetic response around a defect is found to markedly differ
from that observed in non-frustrated antiferromagnetic materials. Finally, we
discuss our relaxation measurements in the light of Cu and Cl NMR data
[cond-mat 070314] and suggest a flat q-dependence of the excitations.


title: Linear dimension-free estimates for the Hermite-Riesz transforms

abstract:
  We utilize the Bellman function technique to prove a bilinear dimension-free
inequality for the Hermite operator. The Bellman technique is applied here to a
non-local operator, which at first did not seem to be feasible. As a
consequence of our bilinear inequality one proves dimension-free boundedness
for the Riesz-Hermite transforms on L^p with linear growth in terms of p. A
feature of the proof is a theorem establishing L^p(R^n) estimates for a class
of spectral multipliers with bounds independent of n and p. Connections with
known results on the Heisenberg group as well as with results for the Hilbert
transform along the parabola are also explored. We believe our approach is
quite universal in the sense that one could apply it to a whole range of Riesz
transforms arising from various differential operators. As a first step towards
this goal we prove our dimension-free bilinear embedding theorem for quite a
general family of Schroedinger semigroups.


title:
[WC] and PG1159 Central Stars of Planetary Nebula: the Need for an
  Alternative to the Born-Again Scenario

abstract:
  Hydrogen-deficient central stars of planetary nebula such as Wolf-Rayet and
PG1159 central stars and some weak emission line stars are primarily composed
of helium and carbon. This abundance is well explained by a scenario where a
single post-AGB star experiences a last helium shell flash which ingests and
burns, or simply dilutes, the remaining hydrogen atmosphere. But despite its
success in matching the photospheric abundances of these stars, this scenario
is faced with several observational challenges. A binary scenario is proposed
here as a more natural way to face some of the most stringent observational
constraints. In this scenario the H-rich primary in a close binary formed
during a common envelope on the AGB, suffers a last helium shell flash, which
results in a H-deficient primary with some of the characteristics needed to
match the observations.


title: Groupo\"ides de Lie et Feuilletages

abstract:
  This is a survey concerning the relationship between Lie Groupoids (and their
morphisms) and singular foliations in the sense of Sussmann-Stefan (considered
from a purely geometrical point of view). We focus on the interaction between
the algebraic and differentiable structures underlying Lie groupoids, and
between groups and graphs of equivalence relations, regarded as two basic
degeneracies for groupoids. Historical remarks, motivations and examples are
developed in five appendices.


title: The Distance of 4 kpc to the SNR CTB 109/AXP 1E 2259+586 system

abstract:
  We suggest a revised distance to the supernova remnant (SNR) G109.1-1.0 (CTB
109) and its associated anomalous X-ray pulsar (AXP) 1E 2259+586 by analyzing
21cm HI-line and 12CO-line spectra of CTB 109, HII region Sh 152, and the
adjacent molecular cloud complex. CTB 109 has been established to be
interacting with a large molecular cloud (recession velocity at v=-55 km s^-1).
The highest radial velocities of absorption features towards CTB 109 (-56 km
s^-1) and Sh 152 (-65 km s^-1) are larger than the recombination line velocity
(-50 km s^-1) of Sh 152 demonstrating the velocity reversal within the Perseus
arm. The molecular cloud has cold HI column density large enough to produce HI
self-absorption (HISA) and HI narrow self-absorption (HINSA) if it was at the
near side of the velocity reversal. Absence of both HISA and HINSA indicates
that the cloud is at the far side of the velocity reversal within the Perseus
Arm, so we obtain a distance for CTB 109 of 4+/-0.8 kpc. The new distance still
leads to a normal explosion energy for CTB 109/AXP 1E 2259+586.


title: Prompt photon production in photoproduction, DIS and hadronic collisions

abstract:
  Recent results on prompt photon production in photoproduction, deeply
inelastic scattering and hadronic collisions are reviewed and the importance of
photons for LHC experiments is briefly discussed.


title: A two-dimensional ruin problem on the positive quadrant

abstract:
  In this paper we study the joint ruin problem for two insurance companies
that divide between them both claims and premia in some specified proportions
(modeling two branches of the same insurance company or an insurance and
re-insurance company). Modeling the risk processes of the insurance companies
by Cram\'{e}r-Lundberg processes we obtain the Laplace transform in space of
the probability that either of the insurance companies is ruined in finite
time. Subsequently, for exponentially distributed claims, we derive an explicit
analytical expression for this joint ruin probability by explicitly inverting
this Laplace transform. We also provide a characterization of the Laplace
transform of the joint ruin time.


title:
Representations of the quantum torus and applications to finitely
  presented groups

abstract:
  A structure theorem is proved for strongly holonomic modules over a quantum
torus (a crossed product of a field with a free abelian group in which the
field is central). This can be applied to give a structure theorem for finitely
presented abelian-by-nilpotent groups.


title:
Constraints on economical 331 models from mixing of K, Bd and Bs neutral
  mesons

abstract:
  We analyze the effect of flavor changing neutral currents within 331 models.
In particular, we concentrate in the so-called "economical" models, which have
a minimal scalar sector. Taking into account the experimental measurements of
observables related to neutral K and B meson mixing, we study the resulting
bounds for angles and phases in the mixing matrix for the down quark sector,
and the mass and mixing parameters related to the new Z' gauge boson.


title: The automorphism groups of the groups of orders $16p$ and $16p^2$

abstract:
  Results of the computation of the automorphism groups for the groups of
orders $16p$ and $16p^{2}$ are given. In some cases it has not been possible to
give as complete a set of results as was done previously for the case of groups
of order $8p^2$. Problems arise for those groups of the form ($C_{p} \times
C_{p}$) @ $\G$[16] that occur in the orders $p\equiv 1$ mod(8) and $p\equiv 7$
mod(8), where $G$[16] means any group of order 16. The groups $G$[16] in
question are $C_{16}$, $D_{8}$, $QD_{8}$, and $Q_{4}$. For the other cases,
explicit presentations are presented for the automorphism groups of the groups
of orders 16$p$ and 16$p^2$.


title: Quasi-local contribution to the scalar self-force: Geodesic Motion

abstract:
  We consider a scalar charge travelling in a curved background spacetime. We
calculate the quasi-local contribution to the scalar self-force experienced by
such a particle following a geodesic in a general spacetime. We also show that
if we assume a massless field and a vacuum background spacetime, the expression
for the self-force simplifies significantly. We consider some specific cases
whose gravitational analog are of immediate physical interest for the
calculation of radiation reaction corrected orbits of binary black hole
systems. These systems are expected to be detectable by the LISA space based
gravitational wave observatory. We also investigate how alternate techniques
may be employed in some specific cases and use these as a check on our own
results.


title: From Characters to Quantum (Super)Spin Chains via Fusion

abstract:
  We give an elementary proof of the Bazhanov-Reshetikhin determinant formula
for rational transfer matrices of the twisted quantum super-spin chains
associated with the gl(K|M) algebra. This formula describes the most general
fusion of transfer matrices in symmetric representations into arbitrary finite
dimensional representations of the algebra and is at the heart of analytical
Bethe ansatz approach. Our technique represents a systematic generalization of
the usual Jacobi-Trudi formula for characters to its quantum analogue using
certain group derivatives.


title: The large scale dust lanes of the Galactic bar

abstract:
  (abridged) By comparing the distribution of dust and gas in the central
regions of the Galaxy, we aim to obtain new insights into the properties of the
offset dust lanes leading the bar's major axis in the Milky Way. On the one
hand, the molecular emission of the dust lanes is extracted from the observed
CO l-b-V distribution according to the interpretation of a dynamical model. On
the other hand, a three dimensional extinction map of the Galactic central
region constructed from near-infrared observations is used as a tracer of the
dust itself and clearly reveals dust lanes in its face-on projection.
Comparison of the position of both independent detections of the dust lanes is
performed in the (l, b) plane. These two completely independent methods are
used to provide a coherent picture of the dust lanes in the Milky Way bar. In
both the gas and dust distributions, the dust lanes are found to be out of the
Galactic plane, appearing at negative latitudes for l > 0 deg and at positive
latitudes for l < 0 deg. However, even though there is substantial overlap
between the two components, they are offset from one another with the dust
appearing to lie closer to the b = 0 deg plane. Two scenarios are proposed to
explain the observed offset. The first involves grain destruction by the bar
shock and reformation downstream. Due to the decrease in velocity caused by the
shock, this occurs at lower z. The second assumes that the gas and dust remain
on a common tilted plane, but that the molecular gas decouples from the Milky
Way's magnetic field, itself strong enough to resist the shear of the bar's
shock. The diffuse gas and dust remain coupled to the field and are carried
further downstream. This second scenario has recently been suggested in order
to explain observations of the barred galaxy NGC 1097.


title:
Strangeness, Charm and Beauty in Quark Matter: SQM 2007 Experimental
  Overview

abstract:
  This paper aims at providing an experimental overview of the Strangeness in
Quark Matter 2007 Conference


title: Parton Distributions for LO Generators

abstract:
  We present a study of the results obtained combining LO partonic matrix
elements with either LO or NLO partons distributions. These are compared to the
best prediction using NLO for both matrix elements and parton distributions.
The aim is to determine which parton distributions are most appropriate to use
in those cases where only LO matrix elements are available, e.g. as in many
Monte Carlo generators. Both LO and NLO parton distributions have flaws,
sometimes serious, for some processes, so a modified optimal LO set is
suggested. We investigate a wide variety of process, and the LO* pdf works at
least as well as, and often better than, both LO and NLO pdfs in nearly all
cases.The LO* pdf set is now available in the LHAPDF package.


title: Casimir effect in deformed field

abstract:
  The Casimir energy is calculated in one-, two-, and three-dimensional spaces
for the field with generalized coordinates and momenta satisfying the deformed
Poisson brackets leading to the minimal length.


title: Photon bremsstrahlung and diffusive broadening of a hard jet

abstract:
  The photon bremsstrahlung rate from a quark jet produced in deep-inelastic
scattering (DIS) off a large nucleus is studied in the collinear limit. The
leading medium-enhanced higher twist corrections which describe the multiple
scattering of the jet in the nucleus are re-summed to all orders of twist. The
propagation of the jet in the absence of further radiative energy loss is shown
to be governed by a transverse momentum diffusion equation. We compute the
final photon spectrum in the limit of soft photons, taking into account the
leading and next-to-leading terms in the photon momentum fraction y. In this
limit, the photon spectrum in a physical gauge is shown to arise from two
interfering sources: one where the initial hard scattering produces an
off-shell quark which immediately radiates the photon and then undergoes
subsequent soft re-scattering; alternatively the quark is produced on-shell and
propagates through the medium until it is driven off-shell by re-scattering and
radiates the photon. Our result has a simple formal structure as a product of
the photon splitting function, the quark transverse momentum distribution
coming from a diffusion equation and a dimensionless factor which encodes the
effect of the interferences encountered by the propagating quark over the
length of the medium. The destructive nature of such interferences in the small
y limit are responsible for the origin of the Landau-Pomeranchuck-Migdal (LPM)
effect. Along the way we also discuss possible implications for quark jets in
hot nuclear matter.


title:
Non-quasiparticle states in Co$_2$MnSi evidenced through magnetic tunnel
  junction spectroscopy measurements

abstract:
  We investigate the effects of electronic correlations in the full-Heusler
Co$_2$MnSi, by combining a theoretical analysis of the spin-resolved density of
states with tunneling-conductance spectroscopy measurements using Co$_2$MnSi as
electrode. Both experimental and theoretical results confirm the existence of
so-called non-quasiparticle states and their crucial contribution to the
finite-temperature spin polarisation in this material.


title: Photometric Redshift Estimation on SDSS Data Using Random Forests

abstract:
  Given multiband photometric data from the SDSS DR6, we estimate galaxy
redshifts. We employ a Random Forest trained on color features and
spectroscopic redshifts from 80,000 randomly chosen primary galaxies yielding a
mapping from color to redshift such that the difference between the estimate
and the spectroscopic redshift is small. Our methodology results in tight RMS
scatter in the estimates limited by photometric errors. Additionally, this
approach yields an error distribution that is nearly Gaussian with parameter
estimates giving reliable confidence intervals unique to each galaxy
photometric redshift.


title: A Compact Self-organizing Cellular Automata-based Genetic Algorithm

abstract:
  A Genetic Algorithm (GA) is proposed in which each member of the population
can change schemata only with its neighbors according to a rule. The rule
methodology and the neighborhood structure employ elements from the Cellular
Automata (CA) strategies. Each member of the GA population is assigned to a
cell and crossover takes place only between adjacent cells, according to the
predefined rule. Although combinations of CA and GA approaches have appeared
previously, here we rely on the inherent self-organizing features of CA, rather
than on parallelism. This conceptual shift directs us toward the evolution of
compact populations containing only a handful of members. We find that the
resulting algorithm can search the design space more efficiently than
traditional GA strategies due to its ability to exploit mutations within this
compact self-organizing population. Consequently, premature convergence is
avoided and the final results often are more accurate. In order to reinforce
the superior mutation capability, a re-initialization strategy also is
implemented. Ten test functions and two benchmark structural engineering truss
design problems are examined in order to demonstrate the performance of the
method.


title:
Enhancement in spin-torque efficiency by nonuniform spin current
  generated within a tapered nanopillar spin valve

abstract:
  We examine the effect a spatially non-uniform spin current with a component
polarized partially out of the plane has on a low saturation magnetization
nanomagnet free layer. Micromagnetic simulations indicate that the spin torque
efficiency acting upon the reversing nanomagnet can be enhanced through this
process, resulting in faster switching with smaller currents. In doing so, we
determine that micromagnetic structure within the nanomagnets can be beneficial
for reversal processes. We verify this enhancement experimentally in devices
with a tapered nanopillar geometry that generates a spin current polarized
partly out of plane. Finally, to take even better advantage of these effects,
we examine micromagnetically the benefits of a tapered three-magnetic-layer
structure that further reduces reversal times while maintaining the thermal
stability of the free layer.


title: Alignments of Voids in the Cosmic Web

abstract:
  We investigate the shapes and mutual alignment of voids in the large scale
matter distribution of a LCDM cosmology simulation. The voids are identified
using the novel WVF void finder technique. The identified voids are quite
nonspherical and slightly prolate, with axis ratios in the order of c:b:a
approx. 0.5:0.7:1. Their orientations are strongly correlated with significant
alignments spanning scales >30 Mpc/h.
  We also find an intimate link between the cosmic tidal field and the void
orientations. Over a very wide range of scales we find a coherent and strong
alignment of the voids with the tidal field computed from the smoothed density
distribution. This orientation-tide alignment remains significant on scales
exceeding twice the typical void size, which shows that the long range external
field is responsible for the alignment of the voids. This confirms the view
that the large scale tidal force field is the main agent for the large scale
spatial organization of the Cosmic Web.


title:
New Multiwavelength Observations of PKS 2155-304 and Implications for
  the Coordinated Variability Patterns of Blazars

abstract:
  The TeV blazar PKS 2155--304 was the subject of an intensive 2 week optical
and near-infrared observing campaign in 2004 August with the CTIO 0.9m
telescope. During this time, simultaneous X-ray data from RXTE were also
obtained. We compare the results of our observations to the results from two
previous simultaneous multiwavelength campaigns on PKS 2155-304. We conclude
that the correlation between the X-ray and UV/optical variability is strongest
and the time lag is shortest (only a few hours) when the object is brightest.
As the object becomes fainter, the correlations are weaker and the lags longer,
increasing to a few days. Based on the results of four campaigns, we find
evidence for a linear relationship between the mean optical brightness and lag
time of X-ray and UV/optical events. Furthermore, we assert that this behavior,
along with the different multiwavelength flare lag times across different flux
states is consistent with a highly relativistic shock propagating down the jet
producing the flares observed during a high state. In a quiescent state, the
variability is likely to be due to a number of factors including both the jet
and contributions outside of the jet, such as the accretion disk.


title:
Transport modulation of graphene nanoribbons with side-attached organic
  molecules

abstract:
  In this work we address the effects on the conductance of graphene
nanoribbons (GNRs) at which organic molecules are side-attached on the ribbon
ends. For simplicity, only armchair (AGNRs) and zigzag (ZGNRs) nanoribbons are
considered and quasi one-dimensional molecules, such as linear poly-aromatic
hydrocarbon (LPHC) and poly(para-phenylene), are chosen. The conductance of the
GNRs exhibit a particular behavior as a function of the length of the organic
molecules: the energy spectrum of the quasi one-dimensional system is clearly
reflected in the conductance curves of the GNRs. The results suggest that GNRs
can be used as an spectrograph-sensor device. An even-odd parity effect, as a
function of the length of the attached molecules, can be observed in the
conductance of these system. The nanostructures are described using a
single-band tight binding Hamiltonian and the electronic conductance and the
density of states of the systems are calculated within the Green's function
formalism based on real-space renormalization techniques.


title: Decoherence by a spin thermal bath: Role of the spin-spin interactions

abstract:
  We study the decoherence of two coupled spins that interact with a spin-bath
environment. It is shown that the connectivity and the coupling strength
between the spins in the environment are of crucial importance for the
decoherence of the central system. Changing the connectivity or coupling
strenghts changes the decoherence of the central system from Gaussian to
exponential decay law.


title: Coefficient Quantization for Frames in Banach Spaces

abstract:
  Let $(e_i)$ be a fundamental system of a Banach space.
  We consider the problem of approximating linear combinations of elements of
this system by linear combinations using quantized coefficients. We will
concentrate on systems which are possibly redundant. Our model for this
situation will be frames in Banach spaces.


title:
Sub-natural width of transparency window in 85Rb vapor with D2
  transition,

abstract:
  We study 85Rb atomic vapor for electromagnetically induced transparency (EIT)
and obtain sub-natural EIT spectra at optical power higher than saturation
intensity. It is shown that spectral width of transmission and intensity of EIT
signal increases with intensity of optical field, which is one of the desirable
features for slow light and quantum information processing. A details analysis
has been done on such an atomic system.


title: An annotation based approach to support design communication

abstract:
  The aim of this paper is to propose an approach based on the concept of
annotation for supporting design communication. In this paper, we describe a
co-operative design case study where we analyse some annotation practices,
mainly focused on design minutes recorded during project reviews. We point out
specific requirements concerning annotation needs. Based on these requirements,
we propose an annotation model, inspired from the Speech Act Theory (SAT) to
support communication in a 3D digital environment. We define two types of
annotations in the engineering design context, locutionary and illocutionary
annotations. The annotations we describe in this paper are materialised by a
set of digital artefacts, which have a semantic dimension allowing
express/record elements of technical justifications, traces of contradictory
debates, etc. In this paper, we first clarify the semantic annotation concept,
and we define general properties of annotations in the engineering design
context, and the role of annotations in different design project situations.
After the description of the case study, where we observe and analyse
annotations usage during the design reviews and minute making, the last section
is dedicated to present our approach. We then describe the SAT concept, and
define the concept of annotation acts. We conclude with a description of basic
annotation functionalities that are actually implemented in a software, based
on our approach.


title:
Self-organization and magnetic domain microstructure of Fe nanowire
  arrays

abstract:
  Starting from essentially flat nanometer-thick Fe films, epitaxially grown at
room temperature on W(110) surfaces, we used carefully tuned annealing
schedules to produce periodic arrays of nanoscale ferromagnetic wires. The
structural transition from continuous films to nanowire arrays is accompanied
with an in-plane 90 degree rotation of the spontaneous magnetization. Using
spin-polarized low-energy electron microscopy to map the local magnetization
directions while annealing, we studied the role of the dewetting mechanism on
the self-organization and magnetization reorientation processes.


title:
Controllability properties of a class of systems modeling swimming
  microscopic organisms

abstract:
  We consider a finite-dimensional model for the motion of microscopic
organisms whose propulsion exploits the action of a layer of cilia covering its
surface. The model couples Newton's laws driving the organism, considered as a
rigid body, with Stokes equations governing the surrounding fluid. The action
of the cilia is described by a set of controlled velocity fields on the surface
of the organism. The first contribution of the paper is the proof that such a
system is generically controllable when the space of controlled velocity fields
is at least three-dimensional. We also provide a complete characterization of
controllable systems in the case in which the organism has a spherical shape.
Finally, we offer a complete picture of controllable and non-controllable
systems under the additional hypothesis that the organism and the fluid have
densities of the same order of magnitude.


title: Axiomatic structure of k-additive capacities

abstract:
  In this paper we deal with the problem of axiomatizing the preference
relations modelled through Choquet integral with respect to a $k$-additive
capacity, i.e. whose M\"obius transform vanishes for subsets of more than $k$
elements. Thus, $k$-additive capacities range from probability measures ($k=1$)
to general capacities ($k=n$). The axiomatization is done in several steps,
starting from symmetric 2-additive capacities, a case related to the Gini
index, and finishing with general $k$-additive capacities. We put an emphasis
on 2-additive capacities. Our axiomatization is done in the framework of social
welfare, and complete previous results of Weymark, Gilboa and Ben Porath, and
Gajdos.


title:
The M\"obius transform on symmetric ordered structures and its
  application to capacities on finite sets

abstract:
  Considering a linearly ordered set, we introduce its symmetric version, and
endow it with two operations extending supremum and infimum, so as to obtain an
algebraic structure close to a commutative ring. We show that imposing symmetry
necessarily entails non associativity, hence computing rules are defined in
order to deal with non associativity. We study in details computing rules,
which we endow with a partial order. This permits to find solutions to the
inversion formula underlying the M\"obius transform. Then we apply these
results to the case of capacities, a notion from decision theory which
corresponds, in the language of ordered sets, to order preserving mappings,
preserving also top and bottom. In this case, the solution of the inversion
formula is called the M\"obius transform of the capacity. Properties and
examples of M\"obius transform of sup-preserving and inf-preserving capacities
are given.


title: Labyrinthine Island Growth during Pd/Ru(0001) Heteroepitaxy

abstract:
  Using low energy electron microscopy we observe that Pd deposited on Ru only
attaches to small sections of the atomic step edges surrounding Pd islands.
This causes a novel epitaxial growth mode in which islands advance in a
snakelike motion, giving rise to labyrinthine patterns. Based on density
functional theory together with scanning tunneling microscopy and low energy
electron microscopy we propose that this growth mode is caused by a surface
alloy forming around growing islands. This alloy gradually reduces step
attachment rates, resulting in an instability that favors adatom attachment at
fast advancing step sections.


title: Heavy Baryons in a Quark Model

abstract:
  A quark model is applied to the spectrum of baryons containing heavy quarks.
The model gives masses for the known heavy baryons that are in agreement with
experiment, but for the doubly-charmed baryon Cascade_{cc}, the model
prediction is too heavy. Mixing between the Cascade_Q and Cascade_Q^\prime
states is examined and is found to be small for the lowest lying states. In
contrast with this, mixing between the Cascade_{bc} and Cascade_{bc}^\prime
states is found to be large, and the implication of this mixing for properties
of these states is briefly discussed. We also examine heavy-quark spin-symmetry
multiplets, and find that many states in the model can be placed in such
multiplets. We compare our predictions with those of a number of other authors.


title:
Effect of surface nanostructure on temperature programmed reaction
  spectroscopy: First-principles kinetic Monte Carlo simulations of CO
  oxidation at RuO2(110)

abstract:
  Using the catalytic CO oxidation at RuO2(110) as a showcase, we employ
first-principles kinetic Monte Carlo simulations to illustrate the intricate
effects on temperature programmed reaction spectroscopy data brought about by
the mere correlations between the locations of the active sites at a
nanostructured surface. Even in the absence of lateral interactions, this
nanostructure alone can cause inhomogeneities that cannot be grasped by
prevalent mean-field data analysis procedures, which thus lead to wrong
conclusions on the reactivity of the different surface species.