title: On Algebraic Solutions to Painleve VI

abstract:
  We announce some results which might bring a new insight into the
classification of algebraic solutions to the sixth Painleve equation. The main
results consist of the rationality of parameters, trigonometric Diophantine
conditions, and what the author calls the Tetrahedral Theorem regarding the
absence of algebraic solutions in certain situations. The method is based on
fruitful interactions between the moduli theoretical formulation of Painleve VI
and dynamics on character varieties via the Riemann-Hilbert correspondence.


title: A Simple Proof On Poincar\'e Conjecture

abstract:
  We give a simple proof on the Poincar\'e's conjecture which states that every
compact smooth $3-$manifold which is homotopically equivalent to $S^3$ is
diffeomorphic to $S^3$.


title:
Measurement of charm production cross-section and leptons from its
  semileptonic decay at RHIC

abstract:
  In this thesis, we present the measurements of $D^{0}\to K\pi$ at low $p_T$
($p_T\leq2$ GeV/$c$) and non-photonic electron spectra ($0.9\leq p_T\leq5$
GeV/$c$) from $D^0$ semi-leptonic decay. In addition, we use a newly proposed
technique to identify muons from charm decays at low $p_T$. The combination of
all these three measurements stringently constrains the total charm production
cross-section at mid-rapidity at RHIC. They also allow the extraction of the
charmed hadron spectral shape and a study of possible charm radial flow in
Au+Au collisions.


title: Stimulated Radiation Cooling

abstract:
  In this paper the Stimulated radiation cooling (SRC) of ion beams and methods
of formation of the broadband laser beams with given spectral distribution are
discussed.


title:
The Bose-Hubbard ground state: extended Bogoliubov and variational
  methods compared with time-evolving block decimation

abstract:
  We determine the ground-state properties of a gas of interacting bosonic
atoms in a one-dimensional optical lattice. The system is modelled by the
Bose-Hubbard Hamiltonian. We show how to apply the time-evolving block
decimation method to systems with periodic boundary conditions, and employ it
as a reference to find the ground state of the Bose-Hubbard model. Results are
compared with recently proposed approximate methods, such as
Hartree-Fock-Bogoliubov (HFB) theories generalised for strong interactions and
the variational Bijl-Dingle-Jastrow method. We find that all HFB methods do not
bring any improvement to the Bogoliubov theory and therefore provide correct
results only in the weakly-interacting limit, where the system is deeply in the
superfluid regime. On the other hand, the variational Bijl-Dingle-Jastrow
method is applicable for much stronger interactions, but is essentially limited
to the superfluid regime as it reproduces the superfluid-Mott insulator
transition only qualitatively.


title:
Dynamics and statistical mechanics of ultra-cold Bose gases using
  c-field techniques

abstract:
  We review phase space techniques based on the Wigner representation that
provide an approximate description of dilute ultra-cold Bose gases. In this
approach the quantum field evolution can be represented using equations of
motion of a similar form to the Gross-Pitaevskii equation but with stochastic
modifications that include quantum effects in a controlled degree of
approximation. These techniques provide a practical quantitative description of
both equilibrium and dynamical properties of Bose gas systems. We develop
versions of the formalism appropriate at zero temperature, where quantum
fluctuations can be important, and at finite temperature where thermal
fluctuations dominate. The numerical techniques necessary for implementing the
formalism are discussed in detail, together with methods for extracting
observables of interest. Numerous applications to a wide range of phenomena are
presented.

categories: cond-mat.stat-mech cond-mat.other physics.atom-ph quant-ph


title: Dynamics of Connected Rigid Bodies in a Perfect Fluid

abstract:
  This paper presents an analytical model and a geometric numerical integrator
for a system of rigid bodies connected by ball joints, immersed in an
irrotational and incompressible fluid. The rigid bodies can translate and
rotate in three-dimensional space, and each joint has three rotational degrees
of freedom. This model characterizes the qualitative behavior of
three-dimensional fish locomotion. A geometric numerical integrator, refereed
to as a Lie group variational integrator, preserves Hamiltonian structures of
the presented model and its Lie group configuration manifold. These properties
are illustrated by a numerical simulation for a system of three connected rigid
bodies.


title: An optimal local approximation algorithm for max-min linear programs

abstract:
  We present a local algorithm (constant-time distributed algorithm) for
approximating max-min LPs. The objective is to maximise $\omega$ subject to $Ax
\le 1$, $Cx \ge \omega 1$, and $x \ge 0$ for nonnegative matrices $A$ and $C$.
The approximation ratio of our algorithm is the best possible for any local
algorithm; there is a matching unconditional lower bound.


title:
Critical behavior of loops and biconnected clusters on fractals of
  dimension d < 2

abstract:
  We solve the O(n) model, defined in terms of self- and mutually avoiding
loops coexisting with voids, on a 3-simplex fractal lattice, using an exact
real space renormalization group technique. As the density of voids is
decreased, the model shows a critical point, and for even lower densities of
voids, there is a dense phase showing power-law correlations, with critical
exponents that depend on n, but are independent of density. At n=-2 on the
dilute branch, a trivalent vertex defect acts as a marginal perturbation. We
define a model of biconnected clusters which allows for a finite density of
such vertices. As n is varied, we get a line of critical points of this
generalized model, emanating from the point of marginality in the original loop
model. We also study another perturbation of adding local bending rigidity to
the loop model, and find that it does not affect the universality class.


title: Van der Waals interactions at surfaces by DFT using Wannier functions

abstract:
  The method recently developed to include Van der Waals interactions in the
Density Functional Theory by using the Maximally-Localized Wannier functions,
is improved and extended to the case of atoms and fragments weakly bonded
(physisorbed) to metal and semimetal surfaces, thus opening the way to
realistic simulations of surface-physics processes, where Van der Waals
interactions play a key role. Successful applications to the case of Ar on
graphite and on the Al(100) surface, and of the H2 molecule on Al(100) are
presented.


title: Antiferromagnetic order in the FFLO state

abstract:
  We investigate the antiferromagnetic (AF) order in the d-wave superconducting
(SC) state at high magnetic fields. A two-dimensional model with on-site
repulsion U, inter-site attractive interaction V and antiferromagnetic exchange
interaction J is solved using the mean field theory. For finite values of U and
J, a first order transition occurs from the normal state to the FFLO state,
while the FFLO-BCS phase transition is second order, consistent with the
experimental results in CeCoIn_5. Although the BCS-FFLO transition is
continuous, the Ne'el temperature of AF order is discontinuous at the phase
boundary because the AF order in the FFLO state is induced by the Andreev bound
state localized in the zeros of FFLO order parameter, while the AF order hardly
occurs in the uniform BCS state. The spatial structure of the magnetic moment
is investigated for the commensurate AF state as well as for the incommensurate
AF state. The influence of the spin fluctuations is discussed for both states.
Since the fluctuations are enhanced in the normal state for incommensurate AF
order, this AF order can be confined in the FFLO state. The experimental
results in CeCoIn_5 are discussed.


title:
Exploring Large Feature Spaces with Hierarchical Multiple Kernel
  Learning

abstract:
  For supervised and unsupervised learning, positive definite kernels allow to
use large and potentially infinite dimensional feature spaces with a
computational cost that only depends on the number of observations. This is
usually done through the penalization of predictor functions by Euclidean or
Hilbertian norms. In this paper, we explore penalizing by sparsity-inducing
norms such as the l1-norm or the block l1-norm. We assume that the kernel
decomposes into a large sum of individual basis kernels which can be embedded
in a directed acyclic graph; we show that it is then possible to perform kernel
selection through a hierarchical multiple kernel learning framework, in
polynomial time in the number of selected kernels. This framework is naturally
applied to non linear variable selection; our extensive simulations on
synthetic datasets and datasets from the UCI repository show that efficiently
exploring the large feature space through sparsity-inducing norms leads to
state-of-the-art predictive performance.


title:
Photoevaporation of Circumstellar Disks by FUV, EUV and X-ray Radiation
  from the Central Star

abstract:
  We calculate the rate of photoevaporation of a circumstellar disk by
energetic radiation (FUV, 6eV $<h\nu<$13.6eV; EUV, 13.6eV $<h\nu<$0.1keV; and
Xrays, $h\nu>0.1$keV) from its central star. We focus on the effects of FUV and
X-ray photons since EUV photoevaporation has been treated previously, and
consider central star masses in the range $0.3-7 {\rm M}_{\odot}$. Contrary to
the EUV photoevaporation scenario, which creates a gap at about $r_g\sim 7\
(M_*/1{\rm M}_{\odot})$ AU and then erodes the outer disk from inside out, we
find that FUV photoevaporation predominantly removes less bound gas from the
outer disk. Heating by FUV photons can cause significant erosion of the outer
disk where most of the mass is typically located. X-rays indirectly increase
the mass loss rates (by a factor $\sim 2$) by ionizing the gas, thereby
reducing the positive charge on grains and PAHs and enhancing FUV-induced grain
photoelectric heating. FUV and X-ray photons may create a gap in the disk at
$\sim 10$ AU under favourable circumstances. Photoevaporation timescales for
M$_* \sim 1{\rm M}_{\odot}$ stars are estimated to be $\sim 10^6$ years, after
the onset of disk irradiation by FUV and X-rays. Disk lifetimes do not vary
much for stellar masses in the range $0.3-3$M$_{\odot}$. More massive stars
($\gtrsim 7 {\rm M}_{\odot}$) lose their disks rapidly (in $\sim 10^5$ years)
due to their high EUV and FUV fields. Disk lifetimes are shorter for shallow
surface density distributions and when the dust opacity in the disk is reduced
by processes such as grain growth or settling. The latter suggests that the
photoevaporation process may accelerate as the dust disk evolves.


title:
Generalized Lattice Model of Multi-Component Systems with Internal
  Degrees of Freedom. I. General consideration

abstract:
  The paper contains the generalization of usual lattice model of
multicomponent systems. The generalization is related to account the following
factors: 1. The short-range parts of interatomic repulsions. These repulsions
are not identical for different pairs of atoms, therefore it is impossible to
take into account the repulsions by means of usual ideal lattice introduction.
2. The long-range interatomic potentials take into account by means of
effective fields approximation. 3. The presence the interatomic potentials
depending on some inner degrees of freedoms such as atomic electric and/or
magnetic momentum. The Helmholtz free energy functional in the generalized
lattice model is reduced to the Ginzburg-Landau-Cahn-Hilliard-like (GLCH) form.
The connection between the interatomic potentials characteristics and the
parameters of the GLCH-like functional is obtained. The equations for both full
and partial equilibrium distributions of the species in multicomponent systems
are derived.


title: Energy diffusion and superdiffusion in oscillators lattice networks

abstract:
  I review here some recent result on the thermal conductivity of chains of
oscillators whose hamiltonian dynamics is perturbed by a noise conserving
energy and momentum.

categories: math-ph cond-mat.stat-mech math.MP math.PR


title:
Quasi-TEM modes in rectangular waveguides: a study based on the
  properties of PMC and hard surfaces

abstract:
  Hard surfaces or magnetic surfaces can be used to propagate quasi-TEM modes
inside closed waveguides. The interesting feature of these modes is an almost
uniform field distribution inside the waveguide. But the mechanisms governing
how these surfaces act, how they can be characterized, and further how the
modes propagate are not detailed in the literature. In this paper, we try to
answer these questions. We give some basic rules that govern the propagation of
the quasi-TEM modes, and show that many of their characteristics (i.e. their
dispersion curves) can be deduced from the simple analysis of the reflection
properties of the involved surfaces.


title: The critical layer in pipe flow at high Reynolds number

abstract:
  We report the computation of a family of traveling wave solutions of pipe
flow up to $Re=75000$. As in all lower-branch solutions, streaks and rolls
feature prominently in these solutions. For large $Re$, these solutions develop
a critical layer away from the wall. Although the solutions are linearly
unstable, the two unstable eigenvalues approach 0 as $Re\to\infty$ at rates
given by $Re^{-0.41}$ and $Re^{-0.87}$ -- surprisingly, the solutions become
more stable as the flow becomes less viscous. The formation of the critical
layer and other aspects of the $Re\to\infty$ limit could be universal to
lower-branch solutions of shear flows. We give implementation details of the
GMRES-hookstep and Arnoldi iterations used for computing these solutions and
their spectra, while pointing out the new aspects of our method.


title:
Heavy Quark Diffusion with Relativistic Langevin Dynamics in the
  Quark-Gluon Fluid

abstract:
  The relativistic diffusion process of heavy quarks is formulated on the basis
of the relativistic Langevin equation in It\^{o} discretization scheme. The
drag force inside the quark-gluon plasma (QGP) is parametrized according to the
formula for the strongly coupled plasma obtained by the AdS/CFT correspondence.
The diffusion dynamics of charm and bottom quarks in QGP is described by
combining the Langevin simulation under the background matter described by the
relativistic hydrodynamics. Theoretical calculations of the nuclear
modification factor R_{AA} and the elliptic flow v_{2} for the single electrons
from the charm and bottom decays are compared with the experimental data from
the relativistic heavy ion collisions. The R_{AA} for electrons with large
transverse momentum (p_{T} > 3 GeV) indicates that the drag force from the QGP
is as strong as the AdS/CFT prediction.


title:
Searching for molecular hydrogen mid-infrared emission in the
  circumstellar environments of Herbig Be stars

abstract:
  Context: Molecular hydrogen (H2) is the most abundant molecule in the
circumstellar (CS) environments of young stars, and is a key element in giant
planet formation. The measurement of the H2 content provides the most direct
probe of the total amount of CS gas, especially in the inner warm
planet-forming regions of the disks.
  Aims: Most Herbig Be stars (HBes) are distant from the Sun and their nature
and evolution are still debated. We therefore conducted mid-infrared
observations of H2 as a tracer of warm gas around HBes known to have gas-rich
CS environments.
  Methods: We report a search for the H2 S(1) emission line at 17.0348 microns
in the CS environments of 5 HBes with the high resolution spectroscopic mode of
VISIR (ESO VLT Imager and Spectrometer for the mid-InfraRed).
  Results: No source shows evidence for H2 emission at 17.0348 microns.
Stringent 3sigma upper limits on the integrated line fluxes are derived.
Depending on the adopted temperature, limits on column densities and masses of
warm gas are also estimated. These non-detections constrain the amount of warm
(>150 K) gas in the immediate CS environments of our target stars to be less
than 1-10 Jupiter masses.


title: Quantum Semi-Markov Processes

abstract:
  We construct a large class of non-Markovian master equations that describe
the dynamics of open quantum systems featuring strong memory effects, which
relies on a quantum generalization of the concept of classical semi-Markov
processes. General conditions for the complete positivity of the corresponding
quantum dynamical maps are formulated. The resulting non-Markovian quantum
processes allow the treatment of a variety of physical systems, as is
illustrated by means of various examples and applications, including quantum
optical systems and models of quantum transport.


title: Influence of roughness on capillary forces between hydrophilic surfaces

abstract:
  Capillary forces have been measured by Atomic Force Microscopy in the
plate-sphere setup between gold, borosilicate glass, GeSbTe, titanium, and UV
irradiated amorphous titaniumdioxide surfaces. The force measurements were
performed as a function contact time and surface roughness in the range 0.2 -
15 nm rms, and relative humidity ranging between 2 and 40 %. It is found that
even for the lowest attainable relative humidity 2 % very large capillary
forces are still present. The latter suggests the persistence of a nanometers
thick adsorbed water layer that acts as a capillary bridge between contacting
surfaces. Moreover, we found a significantly different scaling behavior of the
force with rms roughness for materials with different hydrophilicity as
compared to gold-gold surfaces.


title:
Reconstructing the interaction between the dark matter and holographic
  dark energy

abstract:
  We reconstruct the interaction rate between the dark matter and the
holographic dark energy with the parameterized equation of states and the
future event horizon as the infrared cut-off length. It is shown that the
observational constraints from the 192 SNIa and BAO measurement permit the
negative interaction in the wide region. Moreover, the usual phenomenological
descriptions can not describe the reconstructed interaction well for many
cases. The other possible interaction is also discussed.


title: On satellites in arbitrary categories

abstract:
  We generalize the definition of satellites with respect to presheaves (and
copresheaves) with trace in the sense of Inassaridze; a presheaf with trace is
replaced by a graph with a pair of diagrams defined on it.
  We show that the right satellite functor is left adjoint to the left
satellite functor, and that a functor having a right (left) adjoint preserves
right (left) satellites.
  In particular cases the construction of satellites is given.


title:
On the Generation of X-Ray Photon Pairs: A Verification of the Unruh
  Effect?

abstract:
  We investigate the production of entangled X-ray photons by incoherent double
Compton scattering (IDCS) which seems to be an interesting alternative to
coherent double Compton scattering used in earlier work. Very recently it has
been proposed to use the Unruh effect as a source for photon pairs
(R.Sch\"utzhold et al.,Phys.Rev.Lett. 100, 091301 (2008)). We will discuss this
mechanism in comparison with inverse IDCS.


title: A characteristic number of bundles determined by mass linear pairs

abstract:
  Let $\Delta$ be a Delzant polytope in ${\mathbb R}^n$ and ${\bf b}\in{\mathbb
  Z}^n$.
  Let $E$ denote the symplectic fibration over $S^2$ determined by the pair
$(\Delta, {\bf b})$. We prove the equivalence between the fact that $(\Delta,
{\bf b})$ is a mass linear pair (D. McDuff, S. Tolman, {\em Polytopes with mass
linear functions, part I.} {\tt arXiv:0807.0900 [math.SG]}) and the vanishing
of a characteristic number of $E$ in the following cases: When $\Delta$ is a
$\Delta_{n-1}$ bundle over $\Delta_1$; when $\Delta$ is the polytope associated
with the one point blow up of ${\mathbb C}P^n$; and when $\Delta$ is the
polytope associated with a Hirzebruch surface.


title:
What can we learn from electromagnetic plasmas about the quark-gluon
  plasma?

abstract:
  Ultra-relativistic electromagnetic plasmas can be used for improving our
understanding of the quark-gluon plasma. In the weakly coupled regime both
plasmas can be described by transport theoretical and quantum field theoretical
methods leading to similar results for the plasma properties (dielectric
tensor, dispersion relations, plasma frequency, Debye screening, transport
coefficients, damping and particle production rates). In particular, future
experiments with ultra-relativistic electron-positron plasmas in ultra-strong
laser fields might open the possibility to test these predictions, e.g. the
existence of a new fermionic plasma wave (plasmino). In the strongly coupled
regime electromagnetic plasmas such as complex plasmas can be used as models or
at least analogies for the quark-gluon plasma possibly produced in relativistic
heavy-ion experiments. For example, pair correlation functions can be used to
investigate the equation of state and cross section enhancement for parton
scattering can be explained.


title: Fermion Tunneling Beyond Semiclassical Approximation

abstract:
  Applying the Hamilton-Jacobi method beyond the semiclassical approximation
prescribed in \cite{Majhi3} for the scalar particle, Hawking radiation as
tunneling of Dirac particle through an event horizon is analysed. We show that,
as before, all quantum corrections in the single particle action are
proportional to the usual semiclassical contribution. We also compute the
modifications to the Hawking temperature and Bekenstein-Hawking entropy for the
Schwarzschild black hole. Finally, the coefficient of the logarithmic
correction to entropy is shown to be related with the trace anomaly.


title: Poisson-Lie generalization of the Kazhdan-Kostant-Sternberg reduction

abstract:
  The trigonometric Ruijsenaars-Schneider model is derived by symplectic
reduction of Poisson-Lie symmetric free motion on the group U(n). The commuting
flows of the model are effortlessly obtained by reducing canonical free flows
on the Heisenberg double of U(n). The free flows are associated with a very
simple Lax matrix, which is shown to yield the Ruijsenaars-Schneider Lax matrix
upon reduction.


title: An Eight-Octant Phase-Mask Coronagraph

abstract:
  We present numerical simulations and laboratory experiments on an
eight-octant phase-mask (EOPM) coronagraph. The numerical simulations suggest
that an achievable contrast for the EOPM coronagraph can be greatly improved as
compared to that of a four-quadrant phase-mask (FQPM) coronagraph for a
partially resolved star. On-sky transmission maps reveal that the EOPM
coronagraph has relatively high optical throughput, a small inner working angle
and large discovery space. We have manufactured an eight-segment phase mask
utilizing a nematic liquid-crystal device, which can be easily switched between
the FQPM and the EOPM modes. The laboratory experiments demonstrate that the
EOPM coronagraph has a better tolerance of the tip-tilt error than the FQPM
one. We also discuss feasibility of a fully achromatic and high-throughput EOPM
coronagraph utilizing a polarization interferometric technique.


title:
Process tomography of field damping and measurement of Fock state
  lifetimes by quantum non-demolition photon counting in a cavity

abstract:
  The relaxation of a quantum field stored in a high-$Q$ superconducting cavity
is monitored by non-resonant Rydberg atoms. The field, subjected to repetitive
quantum non-demolition (QND) photon counting, undergoes jumps between photon
number states. We select ensembles of field realizations evolving from a given
Fock state and reconstruct the subsequent evolution of their photon number
distributions. We realize in this way a tomography of the photon number
relaxation process yielding all the jump rates between Fock states. The damping
rates of the $n$ photon states ($0\leq n \leq 7$) are found to increase
linearly with $n$. The results are in excellent agreement with theory including
a small thermal contribution.


title:
Global well-posedness and scattering for the fourth order nonlinear
  Schr\"{o}dinger equations with small data

abstract:
  For $n\geq 3$, we study the Cauchy problem for the fourth order nonlinear
Schr\"{o}dinger equations, for which the existence of the scattering operators
and the global well-posedness of solutions with small data in Besov spaces
$B^{s}_{2,1}(\R^n)$ are obtained. In one spatial dimension, we get the global
well-posedness result with small data in the critical homogeneous Besov spaces
$\dot{B}^{s}_{2,1}$. As a by-product, the existence of the scattering operators
with small data is also obtained. In order to show these results, the global
version of the estimates for the maximal functions and the local smoothing
effects on the fourth order Schr\"{o}dinger semi-groups are established.


title: Compact Toffoli gate using weighted graph states

abstract:
  We introduce three compact graph states that can be used to perform a
measurement-based Toffoli gate. Given a weighted graph of six, seven or eight
qubits, we show that success probabilities of 1/4, 1/2 and 1 respectively can
be achieved. Our study puts a measurement-based version of this important
quantum logic gate within the reach of current experiments. As the graphs are
setup-independent, they could be realized in a variety of systems, including
linear optics and ion-traps.


title: Semimetalic graphene in a modulated electric potential

abstract:
  The $\pi$-electronic structure of graphene in the presence of a modulated
electric potential is investigated by the tight-binding model. The low-energy
electronic properties are strongly affected by the period and field strength.
Such a field could modify the energy dispersions, destroy state degeneracy, and
induce band-edge states. It should be noted that a modulated electric potential
could make semiconducting graphene semimetallic, and that the onset period of
such a transition relies on the field strength. There exist infinite
Fermi-momentum states in sharply contrast with two crossing points (Dirac
points) for graphene without external fields. The finite density of states
(DOS) at the Fermi level means that there are free carriers, and, at the same
time, the low DOS spectrum exhibits many prominent peaks, mainly owing to the
band-edge states.


title:
Character of magnetic excitations in a quasi-one-dimensional
  antiferromagnet near the quantum critical points: Impact on magneto-acoustic
  properties

abstract:
  We report results of magneto-acoustic studies in the quantum spin-chain
magnet NiCl$_2$-4SC(NH$_2$)$_2$ (DTN) having a field-induced ordered
antiferromagnetic (AF) phase. In the vicinity of the quantum critical points
(QCPs) the acoustic $c_{33}$ mode manifests a pronounced softening accompanied
by energy dissipation of the sound wave. The acoustic anomalies are traced up
to $T > T_N$, where the thermodynamic properties are determined by fermionic
magnetic excitations, the "hallmark" of one-dimensional (1D) spin chains. On
the other hand, as established in earlier studies, the AF phase in DTN is
governed by bosonic magnetic excitations. Our results suggest the presence of a
crossover from a 1D fermionic to a 3D bosonic character of the magnetic
excitations in DTN in the vicinity of the QCPs.


title: SURE shrinkage of Gaussian paths and signal identification

abstract:
  Using integration by parts on Gaussian space we construct a Stein Unbiased
Risk Estimator (SURE) for the drift of Gaussian processes using their local and
occupation times. By almost-sure minimization of the SURE risk of shrinkage
estimators we derive an estimation and de-noising procedure for an input signal
perturbed by a continuous-time Gaussian noise.


title: Statistical thermodynamics of a two dimensional relativistic gas

abstract:
  In this article we study a fully relativistic model of a two dimensional
hard-disk gas. This model avoids the general problems associated with
relativistic particle collisions and is therefore an ideal system to study
relativistic effects in statistical thermodynamics. We study this model using
molecular-dynamics simulation, concentrating on the velocity distribution
functions. We obtain results for $x$ and $y$ components of velocity in the rest
frame ($\Gamma$) as well as the moving frame ($\Gamma'$). Our results confirm
that J\"{u}ttner distribution is the correct generalization of
Maxwell-Boltzmann distribution. We obtain the same "temperature" parameter
$\beta$ for both frames consistent with a recent study of a limited
one-dimensional model. We also address the controversial topic of temperature
transformation. We show that while local thermal equilibrium holds in the
moving frame, relying on statistical methods such as distribution functions or
equipartition theorem are ultimately inconclusive in deciding on a correct
temperature transformation law (if any).


title:
Quantitative Study of Polymer Dynamics Through Hierarchical Multi-scale
  Dynamic Simulations

abstract:
  The long time dynamics of polymeric materials has been extensively studied in
the past through various experimental techniques and computer simulations.
While computer simulations typically treat generic, simplified models,
experiments deal with specific chemistries. In this letter we present a
hierarchical approach that combines atomistic and coarse-grained simulations to
quantitatively study polymer dynamics. As an example we predict diffusion
coefficients of atactic polystyrene melts of molecular weights relevant to
polymer processing (up to 50kDa) without any adjustable parameter and compare
the results to experiment.


title:
Dark stars: Implications and constraints from cosmic reionization and
  extragalactic background radiation

abstract:
  Dark stars powered by dark matter annihilation have been proposed as the
first luminous sources in the universe. These stars are believed to form in the
central dark matter cusp of low-mass minihalos. Recent calculations indicate
stellar masses up to \sim1000 solar masses and/or have very long lifetimes. The
UV photons from these objects could therefore contribute significantly to
cosmic reionization. Here we show that such dark star models would require a
somewhat artificial reionization history, based on a double-reionization phase
and a late star-burst near redshift $z\sim6$, in order to fulfill the WMAP
constraint on the optical depth as well as the Gunn-Peterson constraint at
$z\sim6$. This suggests that, if dark stars were common in the early universe,
then models are preferred which predict a number of UV photons similar to
conventional Pop. III stars. This excludes dark stars with 100 solar masses
that enter a main-sequence phase and other models that lead to a strong
increase in the number of UV photons. We also derive constraints for massive as
well as light dark matter candidates from the observed X-ray, gamma-ray and
neutrino background, considering dark matter profiles which have been steepened
during the formation of dark stars. This increases the clumping factor at high
redshift and gives rise to a higher dark matter annihilation rate in the early
universe. We furthermore estimate the potential contribution from the
annihilation products in the remnants of dark stars, which may provide a
promising path to constrain such models further, but which is currently still
uncertain.


title:
Dislocation interaction with C in alpha-Fe: a comparison between atomic
  simulations and elasticity theory

abstract:
  The interaction of C atoms with a screw and an edge dislocation is modelled
at an atomic scale using an empirical Fe-C interatomic potential based on the
Embedded Atom Method (EAM) and molecular statics simulations. Results of atomic
simulations are compared with predictions of elasticity theory. It is shown
that a quantitative agreement can be obtained between both modelling techniques
as long as anisotropic elastic calculations are performed and both the
dilatation and the tetragonal distortion induced by the C interstitial are
considered. Using isotropic elasticity allows to predict the main trends of the
interaction and considering only the interstitial dilatation will lead to a
wrong interaction.


title:
A degenerate kernel method for eigenvalue problems of a class of
  non-compact operators

abstract:
  We consider the eigenvalue problem of certain kind of non-compact linear
operators given as the sum of a multiplication and a kernel operator. A
degenerate kernel method is used to approximate isolated eigenvalues. It is
shown that entries of the corresponding matrix of this method can be evaluated
exactly. The convergence of the method is proved; it is proved that the
convergence rate is $O(h)$. By some numerical examples, we confirm the results.


title: On the permutation capacity of digraphs

abstract:
  We extend several results of the third author and C. Malvenuto on
graph-different permutations to the case of directed graphs and introduce new
open problems. Permutation capacity is a natural extension of Sperner capacity
from finite directed graphs to infinite digraphs. Our subject is combinatorial
in nature, but can be equally regarded as zero-error information theory.


title: Cosmic constraints rule out s-wave annihilation of light dark matter

abstract:
  Light dark matter annihilating into electron-positron pairs emits a
significant amount of internal bremsstrahlung that may contribute to the cosmic
gamma-ray background. The amount of emitted gamma-rays depends on the dark
matter clumping factor. Recent calculations indicate that this value should be
of order $10^6-10^7$. That allows us to calculate the expected gamma-ray
background contribution from dark matter annihilation. We find that the light
dark matter model can be ruled out if a constant thermally-averaged cross
section is assumed (s-wave annihilation). For more massive dark matter
candidates like neutralinos, however, cosmic constraints are weaker.


title: Q-fundamental surfaces in lens spaces

abstract:
  We determine all the Q-fundamental surfaces in $(p,1)$-lens spaces and
$(p,2)$-lens spaces with respect to natural triangulations with $p$ tetrahedra.
  For general $(p,q)$-lens spaces, we give an upper bound for elements of
vectors which represent Q-fundamental surfaces with no quadrilateral normal
disks disjoint from the core circles of lens spaces.
  We also give some examples of non-orientable closed surfaces which are
Q-fundamental surfaces with such quadrilateral normal disks.


title: Populating the swampland: the case of U(1)^496 and E_8 x U(1)^248

abstract:
  For d=10 N=1 SUGRA coupled to d=10 N=1 SYM, anomaly cancellation places
severe constraints on the allowed gauge groups. Besides the ones known to
appear in string theory, only U(1)^496 and E_8 x U(1)^248 are allowed. There
are no known theories of quantum gravity that reduce in some limit to these two
last supergravity theories, and in this note I present some evidence that those
quantum theories might not exist. The first observation is that, upon
compactification, requring that the quantum theory possesses a moduli space
with finite volume typically implies the existence of singularities where the
4d gauge group is enhanced, but for these two theories that gauge enhancement
is problematic from the 10d point of view. I also point out that while these
four supergravity theories present repulson-type singularities, the known
mechanism that repairs those singularities for the first two - the non-Abelian
enhancon - is not available for the last two theories. In short, these two
supergravity theories might be too Abelian for their own good.


title:
Feedback topology and XOR-dynamics in Boolean networks with varying
  input structure

abstract:
  We analyse a model of fixed in-degree Random Boolean Networks in which the
fraction of input-receiving nodes is controlled by a parameter gamma. We
investigate analytically and numerically the dynamics of graphs under a
parallel XOR updating scheme. This scheme is interesting because it is
accessible analytically and its phenomenology is at the same time under
control, and as rich as the one of general Boolean networks. Biologically, it
is justified on abstract grounds by the fact that all existing interactions
play a dynamical role. We give analytical formulas for the dynamics on general
graphs, showing that with a XOR-type evolution rule, dynamic features are
direct consequences of the topological feedback structure, in analogy with the
role of relevant components in Kauffman networks. Considering graphs with fixed
in-degree, we characterize analytically and numerically the feedback regions
using graph decimation algorithms (Leaf Removal). With varying gamma, this
graph ensemble shows a phase transition that separates a tree-like graph region
from one in which feedback components emerge. Networks near the transition
point have feedback components made of disjoint loops, in which each node has
exactly one incoming and one outgoing link. Using this fact we provide
analytical estimates of the maximum period starting from topological
considerations.


title:
An Asymptotic Preserving Scheme for the Euler equations in a strong
  magnetic field

abstract:
  This paper is concerned with the numerical approximation of the isothermal
Euler equations for charged particles subject to the Lorentz force. When the
magnetic field is large, the so-called drift-fluid approximation is obtained.
In this limit, the parallel motion relative to the magnetic field direction
splits from perpendicular motion and is given implicitly by the constraint of
zero total force along the magnetic field lines. In this paper, we provide a
well-posed elliptic equation for the parallel velocity which in turn allows us
to construct an Asymptotic-Preserving (AP) scheme for the Euler-Lorentz system.
This scheme gives rise to both a consistent approximation of the Euler-Lorentz
model when epsilon is finite and a consistent approximation of the drift limit
when epsilon tends to 0. Above all, it does not require any constraint on the
space and time steps related to the small value of epsilon. Numerical results
are presented, which confirm the AP character of the scheme and its Asymptotic
Stability.


title: Matter Collineations of Plane Symmetric Spacetimes

abstract:
  This paper is devoted to the study of matter collineations of plane symmetric
spacetimes (for a particular class of spacetimes) when the energy-momentum
tensor is non-degenerate. There exists many interesting cases where we obtain
proper matter collineations. The matter collineations in these cases are {\it
four}, \emph{five}, {\it six}, \emph{seven} and {\it ten} with some constraints
on the energy-momentum tensor. We have solved some of these constraints to
obtain solutions of the Einstein field equations.


title:
Energy-Momentum of the Friedmann Models in General Relativity and
  Teleparallel Theory of Gravity

abstract:
  This paper is devoted to the evaluation of the energy-momentum density
components for the Friedmann models. For this purpose, we have used
M${\o}$ller's pseudotensor prescription in General Relativity and a certain
energy-momentum density developed from his teleparallel formulation. It is
shown that the energy density of the closed Friedmann universe vanishes on the
spherical shell at the radius $\rho=2\sqrt{3}$. This coincides with the earlier
results available in the literature. We also discuss the energy of the flat and
open models. A comparison shows a partial consistency between the M${\o}$ller's
pseudotensor for General Relativity and teleparallel theory. Further, it is
shown that the results are independent of the free dimensionless coupling
constant of the teleparallel gravity.


title:
Wave Properties of Plasma Surrounding the Event Horizon of a
  Non-Rotating Black Hole

abstract:
  We have studied the wave properties of the cold and isothermal plasma in the
vicinity of the Schwarzschild black hole event horizon. The Fourier analyzed
perturbed 3+1 GRMHD equations are taken on the basis of which the complex
dispersion relations are obtained for non-rotating, rotating non-magnetized and
rotating magnetized backgrounds. The propagation and attenuation vectors along
with the refractive index are obtained (shown in graphs) to study the
dispersive properties of the medium near the event horizon. The results show
that no information can be obtained from the Schwarzschild magnetosphere.
Further, the pressure ceases the existence of normal dispersion of waves.


title:
Asymptotic Electromagnetic Fields in Non-relativistic QED: the Problem
  of Existence Revisited

abstract:
  This paper is devoted to the scattering of photons at electrons in models of
non-relativistic quantum mechanical particles coupled minimally to the soft
modes of the quantized electromagnetic field. We prove existence of scattering
states involving an arbitrary number of asymptotic photons of arbitrarily high
energy. Previously, upper bounds on the photon energies seemed necessary in the
case of $n>1$ asymptotic photons and non-confined, non-relativistic charged
particles.


title:
Carriers of the mid-IR emission bands in PNe reanalysed. Evidence of a
  link between circumstellar and interstellar aromatic dust

abstract:
  It has been shown that the diversity of the aromatic emission features can be
rationalized into different classes of objects, in which differences between
circumstellar and interstellar matter are emphasised. We probe the links
between the mid-IR emitters observed in planetary nebulae (PNe) and their
counterparts in the interstellar medium in order to probe a scenario in which
the latter have been formed in the circumstellar environment of evolved stars.
The mid-IR (6-14 um) emission spectra of PNe and compact HII regions were
analysed on the basis of previous work on photodissociation regions (PDRs).
Galactic, Large Magellanic Cloud (LMC), and Small Magellanic Cloud (SMC)
objects were considered in our sample.We show that the mid-IR emission of PNe
can be decomposed as the sum of six components. Some components made of
polycyclic aromatic hydrocarbon (PAH) and very small grain (VSG) populations
are similar to those observed in PDRs. Others are fitted in an evolutionary
scenario involving the destruction of the aliphatic component observed in the
post-AGB stage, as well as strong processing of PAHs in the extreme conditions
of PNe that leads to a population of very large ionized PAHs. This species
called PAH^x are proposed as the carriers of a characteristic band at 7.90 um.
This band can be used as part of diagnostics that identify PNe in nearby
galaxies and is also observed in galactic compact HII regions. These results
support the formation of the aromatic very small dust particles in the
envelopes of evolved stars, in the Milky Way, as well as in the LMC and SMC,
and their subsequent survival in the interstellar medium.


title: Dyonic D3 branes

abstract:
  We describe embeddings of a single D3-brane in generic IIB supergravity
backgrounds when both electric and magnetic fields are turned on. As a
particular application, we describe a dyonic D3-brane in AdS_5 x S^1, dual to
1/4 BPS states of N=4$ SYM.


title:
Outflow Dynamics in Modeling Oligopoly Markets: The Case of the Mobile
  Telecommunications Market in Poland

abstract:
  In this paper we introduce two models of opinion dynamics in oligopoly
markets and apply them to a situation, where a new entrant challenges two
incumbents of the same size. The models differ in the way the two forces
influencing consumer choice -- (local) social interactions and (global)
advertising -- interact. We study the general behavior of the models using the
Mean Field Approach and Monte Carlo simulations and calibrate the models to
data from the Polish telecommunications market. For one of the models
criticality is observed -- below a certain critical level of advertising the
market approaches a lock-in situation, where one market leader dominates the
market and all other brands disappear. Interestingly, for both models the best
fits to real data are obtained for conformity level $p \in (0.3,0.4)$. This
agrees very well with the conformity level found by Solomon Asch in his famous
social experiment.


title: Accelerating cosmologies from non-local higher-derivative gravity

abstract:
  We study accelerating cosmological solutions of a general class of non-linear
gravities which depend on Gauss-Bonnet and other higher derivative invariants.
To achieve this goal a local formulation with auxiliary scalars for arbitrary
higher-derivative non-local gravity is developed. It is demonstrated that
non-local Gauss-Bonnet gravity can be reduced, in the local formulation, to a
model of string-inspired scalar-Gauss-Bonnet gravity. A natural unification, in
the theory here developed, of the early-time inflation epoch with a late-time
acceleration stage can also be realized.


title: Tight Lagrangian surfaces in $S^2 \times S^2$

abstract:
  We determine all tight Lagrangian surfaces in $S^2 \times S^2$. In
particular, globally tight Lagrangian surfaces in $S^2 \times S^2$ are nothing
but real forms.


title: On the quantum dynamics of a point particle in conical space

abstract:
  A quantum neutral particle, constrained to move on a conical surface, is used
as a toy model to explore bound states due to both a inverse squared distance
potential and a $\delta$-function potential, which appear naturally in the
model. These pathological potentials are treated with the self-adjoint
extension method which yields the correct boundary condition (not necessarily a
null wavefunction) at the origin. We show that the usual boundary condition
requiring that the wavefunction vanishes at the origin is arbitrary and
drastically reduces the number of bound states if used. The situation studied
here is closely related to the problem of a dipole moving in conical space.


title:
Asymptotic Quantum Search and a Quantum Algorithm for Calculation of a
  Lower Bound of the Probability of Finding a Diophantine Equation That Accepts
  Integer Solutions

abstract:
  Several mathematical problems can be modeled as a search in a database. An
example is the problem of finding the minimum of a function. Quantum algorithms
for solving this problem have been proposed and all of them use the quantum
search algorithm as a subroutine and several intermediate measurements are
realized. In this work, it is proposed a new quantum algorithm for finding the
minimum of a function in which quantum search is not used as a subroutine and
only one measurement is needed. This is also named asymptotic quantum search.
As an example, we propose a quantum algorithm based on asymptotic quantum
search and quantum counting able to calculate a lower bound of the probability
of finding a Diophantine equation with integer solution.


title: Pair correlations of a spin-imbalanced Fermi gas on two-leg ladders

abstract:
  We study the pair correlations of a spin-imbalanced two-leg ladder with
attractive interactions, using the density matrix renormalization group method
(DMRG). We identify regions in the phase diagram spanned by the chemical
potential and the magnetic field that can harbor
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like physics. Results for the pair
structure factor, exhibiting multiple pairing wave-vectors, substantiate the
presence of FFLO-like correlations. We further discuss phase separation
scenarios induced by a harmonic trap, which differ from the case of isolated
chains.


title:
Transferring and bounding single photon in waveguide controlled by
  quantum node based on atomic ensemble

abstract:
  We study the scattering process of photons confined in a one dimensional
optical waveguide by a laser controlled atomic ensemble. The investigation
leads to an alternative setup of quantum node controlling the coherent transfer
of single photon in such one dimensional continuum. To exactly solve the
effective scattering equations by using the discrete coordinate approach, we
simulate the linear waveguide as a coupled resonator array at the high energy
limit. We generally calculate the transmission coefficients and its vanishing
at resonace reflects the good controllability of our scheme. We also show that
there exist two bound states to describe the localize photons around the
cavity.


title: Recursive formulas for Welschinger invariants of the projective plane

abstract:
  Welschinger invariants of the real projective plane can be computed via the
enumeration of enriched graphs, called marked floor diagrams. By a purely
combinatorial study of these objects, we prove a Caporaso-Harris type formula
which allows one to compute Welschinger invariants for configurations of points
with any number of complex conjugated points.


title:
Inverse problem for a parabolic system with two components by
  measurements of one component

abstract:
  We consider a $2\times 2$ system of parabolic equations with first and zeroth
coupling and establish a Carleman estimate by extra data of only one component
without data of initial values. Then we apply the Carleman estimate to inverse
problems of determining some or all of the coefficients by observations in an
arbitrary subdomain over a time interval of only one component and data of two
components at a fixed positive time $\theta$ over the whole spatial domain. The
main results are Lipschitz stability estimates for the inverse problems. For
the Lipschitz stability, we have to assume some non-degeneracy condition at
$\theta$ for the two components and for it, we can approximately control the
two components of the $2 \times 2$ system by inputs to only one component. Such
approximate controllability is proved also by our new Carleman estimate.
Finally we establish a Carleman estimate for a $3\times 3$ system for parabolic
equations with coupling of zeroth-order terms by one component to show the
corresponding approximate controllability with a control to one component.


title: Phonon Confinement in Stressed Silicon Nanocluster

abstract:
  Confined acoustic and optical phonons in Si nanoclusters embedded in
sapphire, synthesized using ion-beam implantation are investigated using Raman
spectroscopy. The l = 0 and l = 2 confined acoustic phonons, found at low Raman
shift, are analyzed using complex frequency model and the size of the
nanoparticles are estimated as 4 and 6 nm. For the confined optical phonon, in
contrast to expected red shift, the Raman line shape shows a substantial blue
shift, which is attributed to size dependent compressive stress in the
nanoparticles. The calculated Raman line shape for the stressed nanoparticles
fits well to data. The sizes of Si nanoparticles obtained using complex
frequency model are consistent with the size estimated from the fitting of
confined optical phonon line shapes and those found from X-ray diffraction and
TEM.


title: Probing Dynamics of Single Molecules: Non-linear Spectroscopy Approach

abstract:
  A two level model of a single molecule undergoing spectral diffusion dynamics
and interacting with a sequence of two short laser pulses is investigated.
Analytical solution for the probability of n=0,1,2 photon emission events for
the telegraph and Gaussian processes are obtained. We examine under what
circumstances the photon statistics emerging from such pump-probe set up
provides new information on the stochastic process parameters, and what are the
measurement limitations of this technique. The impulsive and selective limits,
the semiclassical approximation, and the fast modulation limit, exhibit general
behaviors of this new type of spectroscopy. We show, that in the fast
modulation limit, where one has to use impulsive pulses in order to obtain
meaningful results, the information on the photon statistics is contained in
the molecule's dipole correlation function, equivalently to continuous wave
experiments. In contrast, the photon statistics obtained within the selective
limit depends on the both spectral shifts and rates and exhibits oscillations,
which are not found in the corresponding line-shape.


title: Central limit theorem for a class of one-dimensional kinetic equations

abstract:
  We introduce a class of Boltzmann equations on the real line, which
constitute extensions of the classical Kac caricature. The collisional gain
operators are defined by smoothing transformations with quite general
properties. By establishing a connection to the central limit problem, we are
able to prove long-time convergence of the equation's solutions towards a limit
distribution. If the initial condition for the Boltzmann equation belongs to
the domain of normal attraction of a certain stable law $g_\alpha$, then the
limit is non-trivial and is a statistical mixture of dilations of $g_\alpha$.
Under some additional assumptions, explicit exponential rates for the
equilibration in Wasserstein metrics are calculated, and strong convergence of
the probability densities is shown.


title: On the Equicontinuity Region of Discrete Subgroups of PU(1,n)

abstract:
  Let $ G $ be a discrete subgroup of PU(1,n). Then $ G $ acts on $\mathbb
{P}^n_\mathbb C$ preserving the unit ball $\mathbb {H}^n_\mathbb {C}$, where it
acts by isometries with respect to the Bergman metric. In this work we
determine the equicontinuty region $Eq(G)$ of $G$ in $\mathbb P^n_{\mathbb C}$:
It is the complement of the union of all complex projective hyperplanes in
$\mathbb {P}^n_{\mathbb C}$ which are tangent to $\partial \mathbb
{H}^n_\mathbb {C}$ at points in the Chen-Greenberg limit set $\Lambda_{CG}(G
)$, a closed $G$-invariant subset of $\partial \mathbb {H}^n_\mathbb {C}$,
which is minimal for non-elementary groups. We also prove that the action on
$Eq(G)$ is discontinuous.


title:
Condensation in disordered lasers: theory, 3D+1 simulations and
  experiments

abstract:
  The complex processes underlying the generation of a coherent-like emission
from the multiple-scattering of photons and wave-localization in the presence
of structural disorder are still mostly un-explored. Here we show that a single
nonlinear Schroedinger equation, playing the role of the Schawlow-Townes law
for standard lasers, quantitatively reproduces experimental results and
three-dimensional time-domain parallel simulations of a colloidal laser system.


title:
Modified Electron Beam Induced Deposition of Metal Nanostructure Arrays
  using a Parallel Electron Beam

abstract:
  A modified electron beam induced deposition method using a parallel beam of
electrons is developed. The method relies on the build-up of surface potential
on an insulating surface exposed to an electron beam. Presence of sharp edges
on the insulating surface implies presence of large electric fields that lead
to site-specific nucleation of metal vapor on those regions. Feature sizes as
small as 20 nm can be deposited without the need to use fine probes and thus
the limitation of probe size imposed on the resolution is overcome. The use of
pure metal vapor also renders the process inherently clean.


title: Neural Population Coding is Optimized by Discrete Tuning Curves

abstract:
  The sigmoidal tuning curve that maximizes the mutual information for a
Poisson neuron, or population of Poisson neurons, is obtained. The optimal
tuning curve is found to have a discrete structure that results in a
quantization of the input signal. The number of quantization levels undergoes a
hierarchy of phase transitions as the length of the coding window is varied. We
postulate, using the mammalian auditory system as an example, that the presence
of a subpopulation structure within a neural population is consistent with an
optimal neural code.


title: Parallax and Distance Estimates for Twelve Cataclysmic Variable Stars

abstract:
  We report parallax and distance estimates for twelve more cataclysmic
binaries and related objects observed with the 2.4m Hiltner telescope at MDM
Observatory. The final parallax accuracy is typically about 1 mas. For only one
of the twelve objects, IR Gem, do we fail to detect a significant parallax.
Notable results include distances for V396 Hya (CE 315), a helium double
degenerate with a relatively long orbital period, and for MQ Dra
(SDSSJ155331+551615), a magnetic system with a very low accretion rate. We find
that the Z Cam star KT Persei is physically paired with a K main-sequence star
lying 15 arcsec away. Several of the targets have distance estimates in the
literature that are based on the white dwarf's effective temperature and flux;
our measurements broadly corroborate these estimates, but tend to put the stars
a bit closer, indicating that the white dwarfs may have rather larger masses
than assumed. As a side note, we briefly describe radial velocity spectroscopy
that refines the orbital period of V396 Hya to 65.07 +- 0.08 min.


title: Consistent Query Answers in the Presence of Universal Constraints

abstract:
  The framework of consistent query answers and repairs has been introduced to
alleviate the impact of inconsistent data on the answers to a query. A repair
is a minimally different consistent instance and an answer is consistent if it
is present in every repair. In this article we study the complexity of
consistent query answers and repair checking in the presence of universal
constraints.
  We propose an extended version of the conflict hypergraph which allows to
capture all repairs w.r.t. a set of universal constraints. We show that repair
checking is in PTIME for the class of full tuple-generating dependencies and
denial constraints, and we present a polynomial repair algorithm. This
algorithm is sound, i.e. always produces a repair, but also complete, i.e.
every repair can be constructed. Next, we present a polynomial-time algorithm
computing consistent answers to ground quantifier-free queries in the presence
of denial constraints, join dependencies, and acyclic full-tuple generating
dependencies. Finally, we show that extending the class of constraints leads to
intractability. For arbitrary full tuple-generating dependencies consistent
query answering becomes coNP-complete. For arbitrary universal constraints
consistent query answering is \Pi_2^p-complete and repair checking
coNP-complete.


title: A computer verified, monadic, functional implementation of the integral

abstract:
  We provide a computer verified exact monadic functional implementation of the
Riemann integral in type theory. Together with previous work by O'Connor, this
may be seen as the beginning of the realization of Bishop's vision to use
constructive mathematics as a programming language for exact analysis.


title:
Perturbative approach to an exactly solved problem: the Kitaev honeycomb
  model

abstract:
  We analyze the gapped phase of the Kitaev honeycomb model perturbatively in
the isolated-dimer limit. Our analysis is based on the continuous unitary
transformations method which allows one to compute the spectrum as well as
matrix elements of operators between eigenstates, at high order. The starting
point of our study consists in an exact mapping of the original honeycomb spin
system onto a square-lattice model involving an effective spin and a hardcore
boson. We then derive the low-energy effective Hamiltonian up to order 10 which
is found to describe an interacting-anyon system, contrary to the order 4
result which predicts a free theory. These results give the ground-state energy
in any vortex sector and thus also the vortex gap, which is relevant for
experiments. Furthermore, we show that the elementary excitations are emerging
free fermions composed of a hardcore boson with an attached spin- and phase-
operator string. We also focus on observables and compute, in particular, the
spin-spin correlation functions. We show that they admit a multi-plaquette
expansion that we derive up to order 6. Finally, we study the creation and
manipulation of anyons with local operators, show that they also create
fermions, and discuss the relevance of our findings for experiments in optical
lattices.


title: Hawking Radiation of Apparent Horizon in a FRW Universe

abstract:
  Hawking radiation is an important quantum phenomenon of black hole, which is
closely related to the existence of event horizon of black hole. The
cosmological event horizon of de Sitter space is also of the Hawking radiation
with thermal spectrum. By use of the tunneling approach, we show that there is
indeed a Hawking radiation with temperature, $T=1/2\pi \tilde r_A$, for locally
defined apparent horizon of a Friedmann-Robertson-Walker universe with any
spatial curvature, where $\tilde r_A$ is the apparent horizon radius. Thus we
fill in the gap existing in the literature investigating the relation between
the first law of thermodynamics and Friedmann equations, there the apparent
horizon is assumed to have such a temperature without any proof. In addition,
we stress the implication of the Hawking temperature associated with the
apparent horizon.


title:
On Factorization of a Perturbation of a J-selfadjoint Operator Arising
  in Fluid Dynamics

abstract:
  We prove that some perturbation of a J-selfadjoint second order differential
operator admits factorization and use this new representation of the operator
to prove compactness of its resolvent and to find its domain.


title:
Classification of Bipartite and Tripartite Qutrit Entanglement under
  SLOCC

abstract:
  We classify biqutrit and triqutrit pure states under stochastic local
operations and classical communication. By investigating the right singular
vector spaces of the coefficient matrices of the states, we obtain explicitly
two equivalent classes of biqutrit states and twelve equivalent classes of
triqutrit states respectively.


title:
Oblique ion collection in the drift-approximation: how magnetized
  Mach-probes really work

abstract:
  The anisotropic fluid equations governing a frictionless obliquely-flowing
plasma around an essentially arbitrarily shaped three-dimensional ion-absorbing
object in a strong magnetic field are solved analytically in the quasi-neutral
drift-approximation, neglecting parallel temperature gradients. The effects of
transverse displacements traversing the magnetic presheath are also quantified.
It is shown that the parallel collection flux density dependence upon external
Mach-number is $n_\infty c_s \exp[-1 -(M_{\parallel\infty}-
M_\perp\cot\theta)]$ where $\theta$ is the angle (in the plane of field and
drift velocity) of the object-surface to the magnetic-field and
$M_{\parallel\infty}$ is the external parallel flow. The perpendicular drift,
$\M_\perp$, appearing here consists of the external $\E\wedge\B$ drift plus a
weighted sum of the ion and electron electron diamagnetic drifts that depends
upon the total angle of the surface to the magnetic field. It is that somewhat
counter-intuitive combination that an oblique (transverse) Mach probe
experiment measures.


title:
Mass conservative BDF-discontinuous Galerkin/explicit finite volume
  schemes for coupling subsurface and overland flows

abstract:
  Robust and accurate schemes are designed to simulate the coupling between
subsurface and overland flows. The coupling conditions at the interface enforce
the continuity of both the normal flux and the pressure. Richards' equation
governing the subsurface flow is discretized using a Backward Differentiation
Formula and a symmetric interior penalty Discontinuous Galerkin method. The
kinematic wave equation governing the overland flow is discretized using a
Godunov scheme. Both schemes individually are mass conservative and can be used
within single-step or multi-step coupling algorithms that ensure overall mass
conservation owing to a specific design of the interface fluxes in the
multi-step case. Numerical results are presented to illustrate the performances
of the proposed algorithms.


title:
Robust photometric redshift determinations of gamma-ray burst afterglows
  at z > 2

abstract:
  Theory suggests that about 10% of Swift-detected gamma-ray bursts (GRBs) will
originate at redshifts greater than 5 yet a number of high redshift candidates
may be left unconfirmed due to the lack of measured redshifts. Here we
introduce our code, GRBz, a method of simultaneous multi-parameter fitting of
GRB afterglow optical and near infrared, spectral energy distributions. It
allows for early determinations of the photometric redshift, spectral index and
host extinction to be made. We assume that GRB afterglow spectra are well
represented by a power-law decay and model the effects of absorption due to the
Lyman forest and host extinction. We use a genetic algorithm-based routine to
simultaneously fit the parameters of interest, and a Monte Carlo error
analysis. We use GRBs of previously determined spectroscopic redshifts to prove
our method, while also introducing new near infrared data of GRB 990510 which
further constrains the value of the host extinction. Our method is effective in
estimating the photometric redshift of GRBs, relatively unbiased by assumptions
of the afterglow spectral index or the host galaxy extinction. Monte Carlo
error analysis is required as the method of error estimate based on the optimum
population of the genetic algorithm underestimates errors significantly.


title: Cayley Graph Expanders and Groups of Finite Width

abstract:
  We present new infinite families of expander graphs of vertex degree 4, which
is the minimal possible degree for Cayley graph expanders. Our first family
defines a tower of coverings (with covering indices equals 2) and our second
family is given as Cayley graphs of finite groups with very short presentations
with only 2 generators and 4 relations. Both families are based on particular
finite quotients of a group G of infinite upper triangular matrices over the
ring M(3,F2).
  We present explicit vector space bases for the finite abelian quotients of
the lower exponent-2 groups of G by upper triangular subgroups and prove a
particular 3-periodicity of these quotients.
  The pro-2 completion of the group G satisfies the Golod-Shafarevich
inequality $|R| \geq (|X|^2)/4$, it is infinite, not p-adic analytic, contains
a free nonabelian subgroup, but not a free pro-p group. We also conjecture that
the group G has finite width 3 and finite average width 8/3.


title:
Cyclic generators for irreducible representations of affine Hecke
  algebras

abstract:
  We give a detailed account of a combinatorial construction, due to Cherednik,
of cyclic generators for irreducible modules of the affine Hecke algebra of the
general linear group with generic parameter q.


title:
Electroproduction of p \pi^{+} \pi^{-} off protons at 0.2<Q^{2}<0.6
  GeV^{2} and 1.3<W<1.57 GeV with CLAS

abstract:
  This paper reports on the most comprehensive data set obtained on
differential and fully integrated cross sections for the process $e p \to e' p
\pi^{+} \pi^{-} $. The data were collected with the CLAS detector at Jefferson
Laboratory. Measurements were carried out in the so-far unexplored kinematic
region of photon virtuality 0.2 $<$ $Q^{2}$ $<$ 0.6 GeV$^{2}$ and invariant
mass of the final hadron system $W$ from 1.3 to 1.57 GeV. For the first time,
nine independent 1-fold differential cross sections were determined in each bin
of $W$ and $Q^{2}$ covered by the measurements. A phenomenological analysis of
the data allowed us to establish the most significant mechanisms contributing
to the reaction. The non-resonant mechanisms account for a major part of
cross-sections. However, we find sensitivity to s-channel excitations of
low-mass nucleon resonances, especially to the $N(1440)P_{11}$ and
$N(1520)D_{13}$ states in kinematical dependencies of the 1-fold differential
cross-sections.


title: On the quasi-hereditary property for staggered sheaves

abstract:
  Let G be an algebraic group over an algebraically closed field, acting on a
variety X with finitely many orbits. "Staggered sheaves" are certain complexes
of G-equivariant coherent sheaves on X that seem to possess many remarkable
properties. In this paper, we construct "standard" and "costandard" objects in
the category of staggered sheaves, and we prove that that category has enough
projectives and injectives.


title: Cyclotomy and analytic geometry over F_1

abstract:
  Geometry over non--existent "field with one element" $F_1$ conceived by
Jacques Tits [Ti] half a century ago recently found an incarnation, in at least
two related but different guises. In this paper I analyze the crucial role of
roots of unity in this geometry and propose a version of the notion of
"analytic functions" over $F_1$. The paper combines a focused survey with some
new constructions.
  In new version, several local additions and changes are made, references
added.


title: Electroweak Physics at LHC

abstract:
  The Large Hadron Collider, LHC, though meant for discovery, will provide
enough data from early phase to also perform various studies of Standard Model
processes in as yet unexplored kinematic regions. Precision measurements of the
electroweak variables will be possible due to the large rates of W and Z boson
productions combined with clean leptonic signatures. Examples of simulation
results from CMS and ATLAS collaboration studies are presented to show the wide
variety of measurements possible and how various issues like background
estimation, determination of systematic effects will be taken care of by the
experiments.


title:
Evidence for two-gap superconductivity in (Ba,K)Fe_2As_2 by directional
  point contact Andreev reflection spectroscopy

abstract:
  Directional point-contact Andreev-reflection spectroscopy measurements on the
Ba$_{0.55}$K$_{0.45}$Fe$_2$As$_2$ single crystals are presented. The spectra
show significant differences when measured in the $ab$ plane in comparison with
those measured in the $c$ direction of the crystal. In the latter case only a
reduced point-contact conductance around zero bias has been revealed persisting
well above $T_c$ and probably related to the structural and magnetic
transitions in the system. Within the $ab$ plane two superconducting energy
gaps are detected below $T_c$. Here a reduced conductance above $T_c$ could
also be found. The fits of the $ab$-plane data to the superconducting s-wave
two-gap model indicate that the smaller gap has a size below the BCS value
while the large gap reveals much higher coupling strength.


title: Standard Model backgrounds to supersymmetry searches

abstract:
  This work presents a review of the Standard Model sources of backgrounds to
the search of supersymmetry signals. Depending on the specific model, typical
signals may include jets, leptons, and missing transverse energy due to the
escaping lightest supersymmetric particle. We focus on the simplest case of
multijets and missing energy, since this allows us to expose most of the issues
common to other more complex cases. The review is not exhaustive, and is aimed
at collecting a series of general comments and observations, to serve as
guideline for the process that will lead to a complete experimental
determination of size and features of such SM processes.


title:
Critical Behavior of a General O(n)-symmetric Model of two n-Vector
  Fields in D=4-2 epsilon

abstract:
  The critical behaviour of the O(n)-symmetric model with two n-vector fields
is studied within the field-theoretical renormalization group approach in a
D=4-2 epsilon expansion. Depending on the coupling constants the
beta-functions, fixed points and critical exponents are calculated up to the
one- and two-loop order, resp. (eta in two- and three-loop order). Continuous
lines of fixed points and O(n)*O(2) invariant discrete solutions were found.
Apart from already known fixed points two new ones were found. One agrees in
one-loop order with a known fixed point, but differs from it in two-loop order.


title:
Resonant control of stochastic spatio-temporal dynamics in a tunnel
  diode by multiple time delayed feedback

abstract:
  We study the control of noise-induced spatio-temporal current density
patterns in a semiconductor nanostructure (double barrier resonant tunnelling
diode) by multiple time-delayed feedback. We find much more pronounced resonant
features of noise-induced oscillations compared to single time feedback,
rendering the system more sensitive to variations in the delay time $\tau$. The
coherence of noise-induced oscillations measured by the correlation time
exhibits sharp resonances as a function of $\tau$, and can be strongly
increased by optimal choices of $\tau$. Similarly, the peaks in the power
spectral density are sharpened. We provide analytical insight into the control
mechanism by relating the correlation times and mean frequencies of
noise-induced breathing oscillations to the stability properties of the
deterministic stationary current density filaments under the influence of the
control loop. Moreover, we demonstrate that the use of multiple time delays
enlarges the regime in which the deterministic dynamical properties of the
system are not changed by delay-induced bifurcations.


title: Mumford dendrograms and discrete p-adic symmetries

abstract:
  In this article, we present an effective encoding of dendrograms by embedding
them into the Bruhat-Tits trees associated to $p$-adic number fields. As an
application, we show how strings over a finite alphabet can be encoded in
cyclotomic extensions of $\mathbb{Q}_p$ and discuss $p$-adic DNA encoding. The
application leads to fast $p$-adic agglomerative hierarchic algorithms similar
to the ones recently used e.g. by A. Khrennikov and others. From the viewpoint
of $p$-adic geometry, to encode a dendrogram $X$ in a $p$-adic field $K$ means
to fix a set $S$ of $K$-rational punctures on the $p$-adic projective line
$\mathbb{P}^1$. To $\mathbb{P}^1\setminus S$ is associated in a natural way a
subtree inside the Bruhat-Tits tree which recovers $X$, a method first used by
F. Kato in 1999 in the classification of discrete subgroups of
$\textrm{PGL}_2(K)$.
  Next, we show how the $p$-adic moduli space $\mathfrak{M}_{0,n}$ of
$\mathbb{P}^1$ with $n$ punctures can be applied to the study of time series of
dendrograms and those symmetries arising from hyperbolic actions on
$\mathbb{P}^1$. In this way, we can associate to certain classes of dynamical
systems a Mumford curve, i.e. a $p$-adic algebraic curve with totally
degenerate reduction modulo $p$.
  Finally, we indicate some of our results in the study of general discrete
actions on $\mathbb{P}^1$, and their relation to $p$-adic Hurwitz spaces.


title: Universal properties of the near-horizon optical geometry

abstract:
  We make use of the fact that the optical geometry near a static
non-degenerate Killing horizon is asymptotically hyperbolic to investigate
universal features of black hole physics. We show how the Gauss-Bonnet theorem
allows certain lensing scenarios to be ruled in or out. We find rates for the
loss of scalar, vector and fermionic `hair' as objects fall quasi- statically
towards the horizon. In the process we find the Lienard-Wiechert potential for
hyperbolic space and calculate the force between electrons mediated by
neutrinos, extending the flat space result of Feinberg and Sucher. We use the
enhanced conformal symmetry of the Schwarzschild and Reissner-Nordstrom
backgrounds to re-derive the electrostatic field due to a point charge in a
simple fashion.


title: Decoherence of one-dimensional electron system

abstract:
  Recently, there have been many attempts to implement quantum computation
experimentally. For this purpose, quantum coherence should be maintained during
gate operations. Therefore, the control of decoherence is a very important
problem. In present study, we examine the decoherence of one-dimensional
electron system, which coupled with acoustic phonon. The time-dependent
Hatree-Fock approximation is applied for electron system, the Schroinger
equation is applied for phonon.The metal-insulator transition found for
coherence time. The results are the election interaction reduces the coherence
time. We also exmined the Bang-Bang control, the results shows recovery of
coherence.


title: Stabilization in $H^\infty_{\mathbb{R}}(\mathbb{D})$

abstract:
  In this paper we prove the following theorem: Suppose that $f_1,f_2\in
H^\infty_\R(\D)$, with $\norm{f_1}_\infty,\norm{f_2}_{\infty}\leq 1$, with $$
\inf_{z\in\D}(\abs{f_1(z)}+\abs{f_2(z)})=\delta>0. $$ Assume for some
$\epsilon>0$ and small, $f_1$ is positive on the set of $x\in(-1,1)$ where
$\abs{f_2(x)}<\epsilon$ for some $\epsilon>0$ sufficiently small. Then there
exists $g_1, g_1^{-1}, g_2\in H^\infty_\R(\D)$ with $$
\norm{g_1}_\infty,\norm{g_2}_\infty,\norm{g_1^{-1}}_\infty\leq
C(\delta,\epsilon) $$ and $$ f_1(z)g_1(z)+f_2(z)g_2(z)=1\quad\forall z\in\D. $$


title: Highly ionized Fe X-ray lines at energies 7.7-8.6 keV

abstract:
  Fe XXV lines at 1.85 A (6.70 keV) and nearby Fe XXIV satellites have been
widely used for determining the temperature of the hottest parts of solar flare
and tokamak plasmas, though the spectral region is crowded and the lines are
blended during flare impulsive stages. The aim of this work is to show that
similarly excited Fe lines in the 7.7--8.6 keV (1.44--1.61 A) region have the
same diagnostic capability with the advantage of not being so crowded. Spectra
in the 7.7--8.6 keV range are synthesized using the CHIANTI spectral package
for conditions (temperature, turbulent velocities) appropriate to solar flares.
The calculated spectra show that the Fe lines in the 7.7--8.6 keV are well
separated even when turbulent velocities are present, and Fe XXIV/Fe XXV line
ratios should therefore provide valuable tools for diagnosing flares and
tokamak plasmas. It is concluded that Fe lines in the 7.7--8.6 keV range are
ideal for the measurement of flare temperature and for detecting the presence
of low-energy nonthermal electrons present at flare impulsive stages. An
indication of what type of instruments to observe this region is given.


title: Collapse of the Quantum Wavefunction

abstract:
  We show using a realistic Hamiltonian-type model that definite outcomes of
quantum measurements may emerge from quantum evolution of pure states, i.e
quantum dynamics provides a deterministic collapse of the wavefunction in a
quantum measurement process. The relaxation of the wavefunction into a pointer
state with classical properties is driven by the interaction with an
environment. The destruction of superpositions, i.e. choosing a preferred
attraction basin and thereby a preferred pointer state, is caused by a tiny
nonlinearity in the macroscopic measurement apparatus. In more details, we
numerically studied the many-body quantum dynamics of a closed Universe
consisting of a system spin measured by a ferromagnet embedded in a spin-glass
environment. The nonlinear term is the self-induced magnetic field of the
ferromagnet. The statistics for the outcomes of this quantum measurement
process depends on the size of the attraction basins in the measurement
apparatus and are in accordance to Born's rule.


title:
Size Dependence of Current Spin Polarization Through
  Superconductor/Ferromagnet Nanocontacts

abstract:
  The spin polarization P of the transport current through the interface
between superconducting Al and ferromagnetic Fe is determined by means of
Andreev reflection at nanostructured point contacts. We observe a systematic
decrease of P with decreasing contact resistance. Our data provide evidence for
the reduction of P by spin-orbit scattering and thus establish a link between
density-of-states and transport spin polarizations.


title: Square free words as products of commutators

abstract:
  Elements of the commutator subgroup of a free group can be presented as
values of canonical forms, called Wicks forms. We show that, starting from
sufficiently high genus g, there is a sequence of words w(g) which can be
presented by f(g) distinct Wicks forms, where f(g)>g!. Moreover we may choose
these words w(g) to be square free.


title:
Heterogeneous Susceptibles-Infectives model: Mechanistic derivation of
  the power law transmission function

abstract:
  In many epidemiological models a nonlinear transmission function is used in
the form of power law relationship. It is constantly argued that such form
reflects population heterogeneities including differences in the mixing
pattern, susceptibility, and spatial patchiness, although the function itself
is considered phenomenological. Comparison with large-scale simulations show
that models with this transmission function accurately approximate data from
highly heterogeneous sources. In this note we provide a mechanistic derivation
of the power law transmission function, starting with a simple heterogeneous
susceptibles--infectives (SI) model, which is based on a standard mass action
assumption. We also consider the simplest SI model with separable mixing and
compare our results with known results from the literature.


title: On unimodality problems in Pascal's triangle

abstract:
  Many sequences of binomial coefficients share various unimodality properties.
In this paper we consider the unimodality problem of a sequence of binomial
coefficients located in a ray or a transversal of the Pascal triangle. Our
results give in particular an affirmative answer to a conjecture of Belbachir
et al which asserts that such a sequence of binomial coefficients must be
unimodal. We also propose two more general conjectures.


title: The One-Loop Effective Potential in Non-Linear Gauges

abstract:
  We calculate the 1-loop effective potential of an Abelian Higgs model within
the R_{\xi/\sigma} class of non-linear gauges that preserves the Higgs-boson
low-energy theorem. The R_{\xi/\sigma} gauge involves two gauge-fixing
parameters \xi and \sigma, and is a renormalizable extension of the Feynman--'t
Hooft R_\xi set of gauges beyond the 1-loop level. By taking consistently into
account Goldstone--gauge-boson mixing effects, we show how the 1-loop effective
potential evaluated at its extrema is independent of both \xi and \sigma, in
agreement with the Nielsen identity. The 1-loop constant and wavefunction
renormalizations are presented within this non-linear R_{\xi/\sigma} class of
gauges.


title: On "Regular Landsberg metrics are always Berwald" by Z. I. Szabo

abstract:
  A gap in the proof of the finsler "unicorn" conjecture in the paper "Regular
Landsberg metrics are always Berwald" by Z. I. Szabo is pointed out


title:
Comment on "How to Realize Uniform Three-Dimensional Ellipsoidal
  Electron Bunches"

abstract:
  Via systematic numerical simulation we found that the recently propose
'Pancake' scheme [O. J. Luiten et al., Phys. Rev. Lett. 93, 094802 (2004)] does
not generate a beam desired for low emittance, even when compared with the more
traditionally accepted cylindrical beam geometry.


title:
Local singlets, frustration, and unconventional superconductivity in the
  organic charge-transfer solids

abstract:
  We suggest that superconductivity (SC) in the organic charge transfer solids
(CTS) is reached from a Bond-Charge Density Wave (BCDW). We discuss an
effective model for the BCDW to SC transition, an attractive U extended Hubbard
Hamiltonian with repulsive nearest neighbor interaction V. We discuss
experimental consequences of the theory for different classes of CTS
superconductors as well as related inorganic materials.


title: Microlocal condition for non-displaceablility

abstract:
  We formulate a sufficient condition for non-displaceability (by Hamiltonian
symplectomorphisms which are identity outside of a compact) of a pair of
subsets in a cotangent bundle. This condition is based on micro-local analysis
of sheaves on manifolds by Kashiwara-Schapira. This condition is used to prove
that the real projective space and the Clifford torus inside the complex
projective space are mutually non-displaceable


title:
On the relationship between environment and galaxy properties in
  clusters of galaxies

abstract:
  We study the correlation between different properties of bright (L>L*)
galaxies in clusters and the environment in the Sloan Digital Sky Survey
(SDSS). Samples of clusters of galaxies used in this paper are those selected
by Coenda & Muriel that are drawn from the Popesso et al. and Koester et al.
samples. Galaxies in these clusters have been identified in the Main Galaxy
Sample of the Fifth Data Release (DR5) of SDSS. We analyse which galaxy
properties correlate best with either, cluster mass or cluster-centric distance
using the technique by Blanton et al. We find that galaxy properties do not
clearly depend on cluster mass for clusters more massive than M~10^{14}M_sun.
On the other hand, galaxy properties correlate with cluster-centric distance.
The property most affected by the cluster-centric distance is g-r colour,
closely followed by the u-r colour. These results are irrespective of the
cluster selection criteria. The two samples of clusters were identified based
on the X-ray emission and the galaxy colours, respectively. Moreover, the
parameter that best predicts environment (i.e. cluster-centric distance) is the
same found by Martinez & Muriel for groups of galaxies and Blanton at al. for
the local density of field galaxies.


title: Proof of a conjecture on unimodality

abstract:
  Let $P(x)$ be a polynomial of degree $m$, with nonnegative and non-decreasing
coefficients. We settle the conjecture that for any positive real number $d$,
the coefficients of $P(x+d)$ form a unimodal sequence, of which the special
case $d$ being a positive integer has already been asserted in a previous work.
Further, we explore the location of modes of $P(x+d)$ and present some
sufficient conditions on $m$ and $d$ for which $P(x+d)$ has the unique mode
$\lceil{m-d\over d+1}\rceil$.


title: Non-Markovian Dynamics and Entanglement in Quantum Brownian Motion

abstract:
  Dynamical aspects of quantum Brownian motion in a low temperature environment
are investigated. We give a systematic calculation of quantum entanglement
among two Brownian oscillators without invoking Born-Markov approximation
widely used for the study of open systems. Our approach is suitable to probe
short time dynamics at cold temperatures where many experiments on quantum
information processing are performed.


title:
Understanding Compact Object Formation and Natal Kicks: II. The case of
  XTE J1118+480

abstract:
  In recent years, an increasing number of proper motions have been measured
for Galactic X-ray binaries. When supplemented with accurate determinations of
the component masses, orbital period, and donor effective temperature, these
kinematical constraints harbor a wealth of information on the system's past
evolution. Here, we consider all this available information to reconstruct the
full evolutionary history of the black hole X-ray binary XTE J1118+480,
assuming that the system originated in the Galactic disk and the donor has
solar metallicity. This analysis accounts for four evolutionary phases: mass
transfer through the ongoing X-ray phase, tidal evolution before the onset of
Roche-lobe overflow, motion through the Galactic potential after the formation
of the black hole, and binary orbital dynamics due to explosive mass loss and
possibly a black hole natal kick at the time of core collapse. We find that
right after black hole formation, the system consists of a ~6.0-10.0 solar
masses black hole and a ~1.0-1.6 solar masses main-sequence star. We also find
that that an asymmetric natal kick is not only plausible but required for the
formation of this system, and derive a lower and upper limit on the black hole
natal kick velocity magnitude of 80 km/s and 310 km/s, respectively.


title: Entanglement signatures of quantum Hall phase transitions

abstract:
  We study quantum phase transitions involving fractional quantum Hall states,
using numerical calculations of entanglements and related quantities. We tune
finite-size wavefunctions on spherical geometries, by varying the interaction
potential away from the Coulomb interaction. We uncover signatures of quantum
phase transitions contained in the scaling behavior of the entropy of
entanglement between two parts of the sphere. In addition to the entanglement
entropy, we show that signatures of quantum phase transitions also appear in
other aspects of the reduced density matrix of one part of the sphere.


title: When is there a representer theorem? Vector versus matrix regularizers

abstract:
  We consider a general class of regularization methods which learn a vector of
parameters on the basis of linear measurements. It is well known that if the
regularizer is a nondecreasing function of the inner product then the learned
vector is a linear combination of the input data. This result, known as the
{\em representer theorem}, is at the basis of kernel-based methods in machine
learning. In this paper, we prove the necessity of the above condition, thereby
completing the characterization of kernel methods based on regularization. We
further extend our analysis to regularization methods which learn a matrix, a
problem which is motivated by the application to multi-task learning. In this
context, we study a more general representer theorem, which holds for a larger
class of regularizers. We provide a necessary and sufficient condition for
these class of matrix regularizers and highlight them with some concrete
examples of practical importance. Our analysis uses basic principles from
matrix theory, especially the useful notion of matrix nondecreasing function.


title:
The low-mass YSO CB230-A: investigating the protostar and its jet with
  NIR spectroscopy and Spitzer observations

abstract:
  A jet from the low-mass YSO CB230-A had been discovered in NIR narrow-band
images. We aim to investigate the physical properties of the region from where
the jet is launched. Our analysis was carried out using low-resolution NIR
spectra acquired with the camera NICS at the TNG telescope, with JH and HK
grisms and a 1 arcsec-wide slit. These observational data were complemented
with infrared photometric data from the Spitzer space telescope archive. The
relevant physical properties of CB230-A were constrained by SED fitting of
fluxes from the NIR to the mm. The YSO spectrum exhibits a significant number
of atomic and molecular emission and absorption features. The characteristics
of this spectrum suggest that we are observing a region in the close vicinity
of CB230-A, i. e. its photosphere and/or an active accretion disk. The spectra
of the knots in the jet contain a large number of emission lines, including a
rich set of [FeII] lines. Emission due to H2 and [FeII] are not spatially
correlated, confirming that [FeII] and H2 are excited by different mechanisms,
in agreement with the models where [FeII] traces dissociative J-shocks and
molecular hydrogen traces slower C-shocks. By using intensity ratios involving
density-sensitive [FeII] lines, we estimated the electron densities in the jet
(6x10^3-1x10^4 cm^-3). This indicates either high density post-shock regions of
ionised gas or regions with a high degree of ionisation. By combining the
present data with previously obtained maps at NIR- and mm-wavelengths, the
emerging scenario is that CB230-A is a Class 0/I YSO driving an atomic jet that
is observed to be almost monopolar probably due to its inclination to the plane
of the sky and the resulting higher extinction of its red side. This jet
appears energetic enough to drive the molecular outflow observed in the mm.


title:
Euclidean scalar Green functions near the black hole and black brane
  horizons

abstract:
  We discuss approximations of the Riemannian geometry near the horizon. If a
D+1 dimensional manifold N has a bifurcate Killing horizon then we approximate
N by a product of the two-dimensional Rindler space and a D-1 dimensional
Riemannian manifold M. We obtain approximate formulas for scalar Green
functions. We study the behaviour of the Green functions near the horizon and
their dimensional reduction. We show that if M is compact then the Green
function near the horizon can be approximated by the Green function of a
two-dimensional quantum field theory. The correction term is exponentially
small away from the horizon. We extend the results to black brane solutions of
supergravity in 10 and 11 dimensions. The near horizon geometry can be
approximated by N=AdS_p x S_q. We discuss Euclidean Green functions on N and
their behaviour near the horizon.


title: Constructing Perfect Steganographic Systems

abstract:
  We propose steganographic systems for the case when covertexts (containers)
are generated by a finite-memory source with possibly unknown statistics. The
probability distributions of covertexts with and without hidden information are
the same; this means that the proposed stegosystems are perfectly secure, i.e.
an observer cannot determine whether hidden information is being transmitted.
The speed of transmission of hidden information can be made arbitrary close to
the theoretical limit - the Shannon entropy of the source of covertexts. An
interesting feature of the suggested stegosystems is that they do not require
any (secret or public) key.
  At the same time, we outline some principled computational limitations on
steganography. We show that there are such sources of covertexts, that any
stegosystem that has linear (in the length of the covertext) speed of
transmission of hidden text must have an exponential Kolmogorov complexity.
This shows, in particular, that some assumptions on the sources of covertext
are necessary.


title:
First test of $O(\alpha ^{2})$ correction of the orthopositronium decay
  rate

abstract:
  Positronium is an ideal system for the research of the bound state QED. New
precise measurement of orthopositronium decay rate has been performed with an
accuracy of 150 ppm. This result is consistent with the last three results and
also the 2nd order correction. The result combined with the last three is
7.0401$\pm0.0007\mu \mathrm{sec}^{-1}$ (100 ppm), which is consistent with the
2nd order correction and differs from the 1st order calculation by 2.6$\sigma$
It is the first test to validate the 2nd order correction.


title:
The Auslander-Bridger formula and the Gorenstein property for coherent
  rings

abstract:
  The concept of Gorenstein dimension, defined by Auslander and Bridger for
finitely generated modules over a Noetherian ring, is studied in the context of
finitely presented modules over a coherent ring. A generalization of the
Auslander-Bridger formula is established and is used as a cornerstone in the
development of a theory of coherent Gorenstein rings.


title:
Maximum Principles for Vectorial Approximate Minimizers of Nonconvex
  Functionals

abstract:
  We establish Maximum Principles which apply to vectorial approximate
minimizers of the general integral functional of Calculus of Variations. Our
main result is a version of the Convex Hull Property.
  The primary advance compared to results already existing in the literature is
that we have dropped the quasiconvexity assumption of the integrand in the
gradient term. The lack of weak Lower Semicontinuity is compensated by
introducing a nonlinear convergence technique, based on the approximation of
the projection onto a convex set by reflections and on the invariance of the
integrand in the gradient term under the Orthogonal Group.
  Maximum Principles are implied for the relaxed solution in the case of
non-existence of minimizers and for minimizing solutions of the Euler-Lagrange
system of PDE.


title:
Characterizing the insulator adjacent to the superconductor in
  Bi$_2$Sr$_{2-x}$La$_{x}$CuO$_{6+\delta}$ ($x=0.3$)

abstract:
  The time-averaged and low--frequency noise transport properties were
investigated in the vicinity of the superconductor--insulator transition for a
Bi$_2$Sr$_{2-x}$La$_{x}$CuO$_{6+\delta}$ ($x=0.3$) thin film. The results are
consistent with a superconductor (metal) embedded in a strong insulator, the
latter showing two-dimensional variable range hopping properties. The weak
insulator behavior -- if any -- is attributed to the metallic inclusions only.


title:
The partition function of the two-matrix model as an isomonodromic
  tau-function

abstract:
  We consider the Itzykson-Zuber-Eynard-Mehta two-matrix model and prove that
the partition function is an isomonodromic tau function in a sense that
generalizes Jimbo-Miwa-Ueno's. In order to achieve the generalization we need
to define a notion of tau-function for isomonodromic systems where the
ad-regularity of the leading coefficient is not a necessary requirement.


title:
Isoelectronic series of oxygen deficient centers in silica: experimental
  estimation of homogeneous and inhomogeneous spectral widths

abstract:
  We report nanosecond time-resolved photoluminescence measurements on the
isoelectronic series of oxygen deficient centers in amorphous silica,
Si-ODC(II), Ge-ODC(II) and Sn-ODC(II) which are responsible of fluorescence
activities at $\sim$4 eV under excitation at $\sim$5 eV. The dependence of the
first moment of their emission band on time, and that of the radiative decay
lifetime on emission energy are analyzed within a theoretical model able to
describe the effects introduced by disorder on the optical properties of the
defects. We obtain separate estimates of the homogeneous and inhomogeneous
contributions to the measured emission linewidth and we derive homogeneous
spectroscopic features of the investigated point defects (Huangh-Rhys factor,
homogeneous width, oscillator strength, vibrational frequency). The results
point to a picture in which an oxygen deficient center localized on a heavier
atom features a higher degree of inhomogeneity due to stronger local distortion
of the surrounding matrix. For Si, Ge, Sn related defects the parameter
$\lambda$, able to quantify inhomogeneity, results to be 65, 78 and 90$%,
respectively.


title: A sectorial approach to Kaluza-Klein theory

abstract:
  The Kaluza and Klein versions of Kaluza-Klein theory are reviewed and
compared. The differences in the field equations of the two theories are
related to the transformation properties of the metrics employed. Based on this
comparison a modified version of the Kaluza theory is proposed, in which the
different sectors of the metric which describe gravitation, electromagnetism
and the scalar field are considered to be partially separate entities, with
distinct coordinate transformation properties. In addition, the cylinder
condition is relaxed, so that it only affects the 4-D sector of the metric.
This results in a theory in which the gravitational and electromagnetic fields
are restricted to a four-dimensional brane, and the scalar field is restricted
to the 5-D bulk.