title: Degenerations of graded Cohen-Macaulay modules

abstract:
  We introduce a notion of degenerations of graded modules. In relation to it,
we also introduce several partial orders as graded analogies of the hom order,
the degeneration order and the extension order. We prove that these orders are
identical on the graded Cohen-Macaulay modules if a graded ring is of graded
finite representation type and representation directed.


title:
Interacting closed string tachyon with modified Chaplygin gas and its
  stability

abstract:
  In this paper, we have considered closed string tachyon model with a constant
dilaton field and interacted it with Chaplygin gas for evaluating cosmology
parameters. The model has been studied in $26$-dimensional that its
$22$-dimensional is related to compactification on an internal non-flat space
and its other $4$-dimensions is related to FLRW metric. By taking the internal
curvature as a negative constant, we obtained the closed string tachyon
potential as a quartic equation. The tachyon field and the scale factor have
been achieved as functional of time evolution and geometry of curved space
where the behaviour of the scale factor describes an accelerated expansion of
the universe. Next, we discussed the stability of our model by introducing a
sound speed factor, which one must be, in our case, a positive function. By
drawing sound speed against time evolution we investigated stability conditions
for non-flat universe in its three stages: early, late and future time. As a
result we shall see that in these cases remains an instability at early time
and a stability point at late time.


title:
Glass Transitions and Critical Points in Orientationally Disordered
  Crystals and Structural Glassformers: "Strong" Liquids are More Interesting
  Than We Thought

abstract:
  When liquids are classified using Tg -scaled Arrhenius plots of relaxation
times (or relative rates of entropy increase above Tg) across a
"strong-fragile" spectrum of behaviors, the "strong" liquids have always
appeared rather uninteresting [1, 2]. Here we use updated plots of the same
type for crystal phases of the "rotator" variety [3] to confirm that the same
pattern of behavior exists for these simpler (center of mass ordered) systems.
However, in this case we can show that the "strong" systems owe their behavior
to the existence of lambda-type order-disorder transitions at higher
temperatures (directly observable in the cases where observations are not
interrupted by prior melting). Furthermore, the same observation can be made
for other systems in which the glass transition, at which the ordering is
arrested, occurs in the thermodynamic ground state of the system. This prompts
an enquiry into the behavior of strong liquids at high temperatures. Using the
case of silica itself, we again find strong evidence from extended ion dynamics
simulations, for a lambda transition at high temperatures, but only if pressure
is adjusted to a critical value. In this case the lambda point is identifiable
as a liquid-liquid critical point of the type suggested for supercooled water.
We recognize the possibility of exploring, a postiori, the consequences of
rapid cooling of laboratory liquid SiO2 from >5000K and multi-GPa pressures,
using the phenomenology of damage-induced plasmas in optical fibers. The
ramifications of these considerations will be explored to establish a "big
picture"2 of the relation of thermodynamic transitions to supercooled liquid
phenomenology [4, 5].


title:
Analytical description of high-aperture STED resolution with 0-2$\pi$
  vortex phase modulation

abstract:
  Stimulated emission depletion (STED) can achieve optical super-resolution,
with the optical diffraction limit broken by the suppression on the periphery
of the fluorescent focal spot. Previously, it is generally experimentally
accepted that there exists an inverse square root relationship with the STED
power and the resolution, yet without strict analytical description. In this
paper, we have analytically verified the relationship between the STED power
and the achievable resolution from vector optical theory for the widely used
0-2$\pi$ vortex phase modulation. Electromagnetic fields of the focal region of
a high numerical aperture objective are calculated and approximated into
polynomials, and analytical expression of resolution as a function of the STED
intensity has been derived. As a result, the resolution can be estimated
directly from the measurement of the saturation power of the dye and the STED
power applied.


title: The Occurrence Rate of Small Planets around Small Stars

abstract:
  We use the optical and near-infrared photometry from the Kepler Input Catalog
to provide improved estimates of the stellar characteristics of the smallest
stars in the Kepler target list. We find 3897 dwarfs with temperatures below
4000K, including 64 planet candidate host stars orbited by 95 transiting planet
candidates. We refit the transit events in the Kepler light curves for these
planet candidates and combine the revised planet/star radius ratios with our
improved stellar radii to revise the radii of the planet candidates orbiting
the cool target stars. We then compare the number of observed planet candidates
to the number of stars around which such planets could have been detected in
order to estimate the planet occurrence rate around cool stars. We find that
the occurrence rate of 0.5-4 Earth radius planets with orbital periods shorter
than 50 days is 0.90 (+0.04/-0.03) planets per star. The occurrence rate of
Earth-size (0.5-1.4 Earth radius) planets is constant across the temperature
range of our sample at 0.51 (+0.06/-0.05) Earth-size planets per star, but the
occurrence of 1.4-4 Earth radius planets decreases significantly at cooler
temperatures. Our sample includes 2 Earth-size planet candidates in the
habitable zone, allowing us to estimate that the mean number of Earth-size
planets in the habitable zone is 0.15 (+0.13/-0.06) planets per cool star. Our
95% confidence lower limit on the occurrence rate of Earth-size planets in the
habitable zones of cool stars is 0.04 planets per star. With 95% confidence,
the nearest transiting Earth-size planet in the habitable zone of a cool star
is within 21 pc. Moreover, the nearest non-transiting planet in the habitable
zone is within 5 pc with 95% confidence.


title: Constructions of Large Graphs on Surfaces

abstract:
  We consider the degree/diameter problem for graphs embedded in a surface,
namely, given a surface $\Sigma$ and integers $\Delta$ and $k$, determine the
maximum order $N(\Delta,k,\Sigma)$ of a graph embeddable in $\Sigma$ with
maximum degree $\Delta$ and diameter $k$. We introduce a number of
constructions which produce many new largest known planar and toroidal graphs.
We record all these graphs in the available tables of largest known graphs.
Given a surface $\Sigma$ of Euler genus $g$ and an odd diameter $k$, the
current best asymptotic lower bound for $N(\Delta,k,\Sigma)$ is given by
\[\sqrt{\frac{3}{8}g}\Delta^{\lfloor k/2\rfloor}.\] Our constructions produce
new graphs of order \[\begin{cases}6\Delta^{\lfloor k/2\rfloor}& \text{if
$\Sigma$ is the Klein bottle}\\
\(\frac{7}{2}+\sqrt{6g+\frac{1}{4}}\)\Delta^{\lfloor k/2\rfloor}&
\text{otherwise,}\end{cases}\] thus improving the former value by a factor of
4.


title:
Eye-GUIDE (Eye-Gaze User Interface Design) Messaging for
  Physically-Impaired People

abstract:
  Eye-GUIDE is an assistive communication tool designed for the paralyzed or
physically impaired people who were unable to move parts of their bodies
especially people whose communications are limited only to eye movements. The
prototype consists of a camera and a computer. Camera captures images then it
will be send to the computer, where the computer will be the one to interpret
the data. Thus, Eye-GUIDE focuses on camera-based gaze tracking. The proponent
designed the prototype to perform simple tasks and provides graphical user
interface in order the paralyzed or physically impaired person can easily use
it.


title: Fractional BV spaces and first applications to scalar conservation laws

abstract:
  The aim of this paper is to obtain new fine properties of entropy solutions
of nonlinear scalar conservation laws. For this purpose, we study some
"fractional $BV$ spaces" denoted $BV^s$, for $0 < s \leq 1$, introduced by Love
and Young in 1937. The $BV^s(\R)$ spaces are very closed to the critical
Sobolev space $W^{s,1/s}(\R)$. We investigate these spaces in relation with
one-dimensional scalar conservation laws. $BV^s$ spaces allow to work with less
regular functions than BV functions and appear to be more natural in this
context. We obtain a stability result for entropy solutions with $BV^s$ initial
data. Furthermore, for the first time we get the maximal $W^{s,p}$ smoothing
effect conjectured by P.-L. Lions, B. Perthame and E. Tadmor for all nonlinear
degenerate convex fluxes.


title:
Invariant distribution of duplicated diffusions and application to
  Richardson-Romberg extrapolation

abstract:
  With a view to numerical applications we address the following question:
given an ergodic Brownian diffusion with a unique invariant distribution, what
are the invariant distributions of the duplicated system consisting of two
trajectories? We mainly focus on the interesting case where the two
trajectories are driven by the same Brownian path. Under this assumption, we
first show that uniqueness of the invariant distribution (weak confluence) of
the duplicated system is essentially always true in the one-dimensional case.
In the multidimensional case, we begin by exhibiting explicit counter-examples.
Then, we provide a series of weak confluence criterions (of integral type) and
also of a.s. pathwise confluence, depending on the drift and diffusion
coefficients through a non-infinitesimal Lyapunov exponent. As examples, we
apply our criterions to some non-trivially confluent settings such as classes
of gradient systems with non-convex potentials or diffusions where the
confluence is generated by the diffusive component. We finally establish that
the weak confluence property is connected with an optimal transport problem. As
a main application, we apply our results to the optimization of the
Richardson-Romberg extrapolation for the numerical approximation of the
invariant measure of the initial ergodic Brownian diffusion.


title: U-geometry : SL(5)

abstract:
  Recently Berman and Perry constructed a four-dimensional M-theory effective
action which manifests SL(5) U-duality. Here we propose an underlying
differential geometry of it, under the name `SL(5) U-geometry' which
generalizes the ordinary Riemannian geometry in an SL(5) compatible manner. We
introduce a `semi-covariant' derivative that can be converted into fully
covariant derivatives after anti-symmetrizing or contracting the SL(5) vector
indices appropriately. We also derive fully covariant scalar and Ricci-like
curvatures which constitute the effective action as well as the equation of
motion.


title:
Scheme for a spin-based quantum computer employing induction detection
  and imaging

abstract:
  A theoretical spin-based scheme for performing a variety of quantum
computations is presented. It makes use of an array of multiple identical
computer vectors of phosphorus-doped silicon where the nuclei serve as logical
qubits and the electrons as working qubits. The spins are addressed by a
combination of electron spin resonance and nuclear magnetic resonance
techniques operating at a field of ~3.3 T and cryogenic temperatures with an
ultra-sensitive surface microresonator. Spin initialization is invoked by a
combination of strong pre-polarization fields and laser pulses, which shortens
the electrons' T1. The set of universal quantum gates for this system includes
an arbitrary rotation of single qubits and c-NOT operation in two qubits. The
efficient parallel readout of all the spins in the system is performed by high
sensitivity induction detection of the electron spin resonance signals with
one-dimensional imaging. Details of the suggested scheme are provided, which
show that it is scalable to a few hundreds of qubits.


title: Multiple Hilbert transform associated with polynomials

abstract:
  We study conditions determining the $L^p$ boundedness of multiple Hilbert
transforms associated with polynomials.


title: Etale covers of Kawamata log terminal spaces and their smooth loci

abstract:
  Working with a singular variety X, one is often interested in comparing the
set of etale covers of X with that of its smooth locus X_reg. More precisely,
one may ask: What are the obstructions to extend finite etale covers of X_reg
to all of X? How do the etale fundamental groups of X and of its smooth locus
compare? For projective varieties with Kawamata log terminal (klt)
singularities we answer these questions in part. The main result of this paper
asserts that there are no infinite towers of finite morphisms over a klt base
variety where all morphisms are etale in codimension one, but branched over a
small set. In a certain sense, this result can be seen as saying that the
difference between the etale covers of X and those of X_reg is finite if X is
klt. As an immediate application, we construct a finite covering Y of X, etale
in codimension one, such that the etale fundamental groups of Y and Y_reg
agree.


title: A canonical rank-three tensor model with a scaling constraint

abstract:
  A rank-three tensor model in canonical formalism has recently been proposed.
The model describes consistent local-time evolutions of fuzzy spaces through a
set of first-class constraints which form an on-shell closed algebra with
structure functions. In fact, the algebra provides an algebraically consistent
discretization of the Dirac-DeWitt constraint algebra in the canonical
formalism of general relativity. However, the configuration space of this model
contains obvious degeneracies of representing identical fuzzy spaces. In this
paper, to delete the degeneracies, another first-class constraint representing
a scaling symmetry is added to propose a new canonical rank-three tensor model.
A consequence is that, while classical solutions of the previous model have
typically runaway or vanishing behaviors, the new model has a compact
configuration space and its classical solutions asymptotically approach either
fixed points or cyclic orbits in time evolution. Among others, fixed points
contain configurations with group symmetries, and may represent stationary
symmetric fuzzy spaces. Another consequence on the uniqueness of the local
Hamiltonian constraint is also discussed, and a minimal canonical tensor model,
which is unique, is given.


title:
Electroweak corrections to the direct detection cross section of inert
  higgs dark matter

abstract:
  The inert higgs model is a minimal extension of the Standard Model that
features a viable dark matter candidate, the so-called inert higgs ($H^0$). In
this paper, we compute and analyze the dominant electroweak corrections to the
direct detection cross section of dark matter within this model. These
corrections arise from one-loop diagrams mediated by gauge bosons that,
contrary to the tree-level result, do not depend on the unknown scalar coupling
$\lambda$. We study in detail these contributions and show that they can modify
in a significant way the prediction of the spin-independent direct detection
cross section. In both viable regimes of the model, $\mh<M_W$ and $\mh\gtrsim
500 \gev$, we find regions where the cross section at one-loop is much larger
than at tree-level. We also demonstrate that, over the entire viable parameter
space of this model, these new contributions bring the spin-independent cross
section within the reach of future direct detection experiments.


title:
A Family Of Estimators Of Population Mean Using Information On Point
  Bi-Serial and Phi Correlation Coefficient

abstract:
  This paper deals with the problem of estimating the finite population mean
when some information on two auxiliary attributes are available. It is shown
that the proposed estimator is more efficient than the usual mean estimator and
other existing estimators. The study is also extended to two-phase sampling.
The results have been illustrated numerically by taking empirical population
considered in the literature.


title: Graded integral closures

abstract:
  It is investigated how graded variants of integral and complete integral
closures behave under coarsening functors and under formation of group
algebras.


title:
Non-adiabatic time-dependent density functional theory of the impurity
  resistivity of metals

abstract:
  We make use of the time-dependent density functional theory to derive a new
formally exact expression for the dc resistivity of metals with impurities.
This expression takes fully into account the dynamics of electron-electron
interactions. Correction to the conventional $T$-matrix (phase-shifts) theory
is treated within hydrodynamics of inhomogeneous viscous electron liquid. As a
first application, we present calculations of the residual resistivity of
aluminum as a function of the atomic number of the impurities. We show that the
inclusion of many-body corrections considerably improves the agreement between
theory and experiment.


title:
Trends in structural, electronic properties, Fermi surface topology, and
  inter-atomic bonding in the series of ternary layered dichalcogenides KNi2S2,
  KNi2Se2, and KNi2Te2 from first principles calculations

abstract:
  By means of the FLAPW-GGA approach, we have systematically studied the
structural and electronic properties of tetragonal dichalcogenides KNi2Ch2 (Ch
= S, Se, and Te). Our results show that replacements of chalcogens (S -> Se ->
Te) lead to anisotropic deformations of the crystals structure, which are
related to the strong anisotropic character of the inter-atomic bonds, where
inside the [Ni2Ch2] blocks, mixed covalent-ionic-metallic bonds occur, whereas
between the adjacent [Ni2Ch2] blocks and K atomic sheets, ionic bonds emerge.
We found that in the sequence KNi2S2 -> KNi2Se2 -> KNi2Te2 (i) the overall band
structure (where the near-Fermi valence bands are due mainly to the Ni states)
is preserved, but the width of the common valence band and the widths of the
separate subbands and the gaps decrease; (ii) the total DOSs at the Fermi level
also decrease; and (iii) for the Fermi surfaces, the most appreciable changes
are demonstrated by the hole-like sheets, when a necklace-like topology is
formed for the 2D-like sheets and the volume of the closed pockets decreases.
Some trends in structural and electronic parameters for ThCr2Si2-type layered
dichalcogenides, KNi2Ch2, KFe2Ch2, KCo2Se2, are discussed.


title: A generalized family of discrete PT-symmetric square wells

abstract:
  N-site-lattice Hamiltonians H are introduced and perceived as a set of
systematic discrete approximants of a certain PT-symmetric
square-well-potential model with the real spectrum and with a non-Hermiticity
which is localized near the boundaries of the interval. Its strength is
controlled by one, two or three parameters. The problem of the explicit
construction of a nontrivial metric which makes the theory unitary is then
addressed. It is proposed and demonstrated that due to the not too complicated
tridiagonal-matrix form of our input Hamiltonians the computation of the metric
is straightforward and that its matrix elements prove obtainable,
non-numerically, in elementary polynomial forms.


title:
Joint Scalable Coding and Routing for 60 GHz Real-Time Live HD Video
  Streaming Applications

abstract:
  Transmission of high-definition (HD) video is a promising application for 60
GHz wireless links, since very high transmission rates (up to several Gbit/s)
are possible. In particular we consider a sports stadium broadcasting system
where signals from multiple cameras are transmitted to a central location. Due
to the high pathloss of 60 GHz radiation over the large distances encountered
in this scenario, the use of relays might be required. The current paper
analyzes the joint selection of the routes (relays) and the compression rates
from the various sources for maximization of the overall video quality. We
consider three different scenarios: (i) each source transmits only to one relay
and the relay can receive only one data stream, and (ii) each source can
transmit only to a single relay, but relays can aggregate streams from
different sources and forward to the destination, and (iii) the source can
split its data stream into parallel streams, which can be transmitted via
different relays to the destination. For each scenario, we derive the
mathematical formulations of the optimization problem and re-formulate them as
convex mixed-integer programming, which can guarantee optimal solutions.
Extensive simulations demonstrate that high-quality transmission is possible
for at least ten cameras over distances of 300 m. Furthermore, optimization of
the video quality gives results that can significantly outperform algorithms
that maximize data rates.


title:
Generalized Theory of Forster-type Nonradiative Energy Transfer in
  Nanostructures with Mixed Dimensionality

abstract:
  Forster-type nonradiative energy transfer (NRET) is widely used, especially
utilizing nanostructures in different combinations and configurations. However,
the existing well-accepted Forster theory is only for the case of a single
particle serving as a donor together with another particle serving as an
acceptor. There are also other special cases previously studied; however, there
is no complete picture and unified understanding. Therefore, there is a strong
need for a complete theory that models Forster-type NRET for the cases of mixed
dimensionality including all combinations and configurations. We report a
generalized theory for the Forster-type NRET, which includes the derivation of
the effective dielectric function due to the donor in different confinement
geometries and the derivation of transfer rates distance dependencies due to
the acceptor in different confinement geometries, resulting in a complete
picture and understanding of the mixed dimensionality.


title:
A new scheme of causal viscous hydrodynamics for relativistic heavy-ion
  collisions: A Riemann solver for quark-gluon plasma

abstract:
  In this article, we present a state-of-the-art algorithm for solving the
relativistic viscous hydrodynamics equation with the QCD equation of state. The
numerical method is based on the second-order Godunov method and has less
numerical dissipation, which is crucial in describing of quark-gluon plasma in
high-energy heavy-ion collisions. We apply the algorithm to several numerical
test problems such as sound wave propagation, shock tube and blast wave
problems. In sound wave propagation, the intrinsic numerical viscosity is
measured and its explicit expression is shown, which is the second-order of
spatial resolution both in the presence and absence of physical viscosity. The
expression of the numerical viscosity can be used to determine the maximum cell
size in order to accurately measure the effect of physical viscosity in the
numerical simulation.

categories: nucl-th astro-ph.CO astro-ph.HE hep-ph nucl-ex


title:
Gaussian approximation to the extreme value index estimator of a
  heavy-tailed distribution under random censoring

abstract:
  We make use of the empirical process theory to approximate the adapted Hill
estimator, for censored data, in terms of Gaussian processes. Then, we derive
its asymptotic normality, only under the usual second-order condition of
regular variation. Our methodology allows to relax the assumptions, made in
Einmahl, Fils-Villetard and Guillou(2008), on the heavy-tailed distribution
functions and the sample fraction of upper order statistics.


title: A user profile based access control model and architecture

abstract:
  Personalization and adaptation to the user profile capability are the hottest
issues to ensure ambient assisted living and context awareness in nowadays
environments. With the growing healthcare and wellbeing context aware
applications, modeling security policies becomes an important issue in the
design of future access control models. This requires rich semantics using
ontology modeling for the management of services provided to dependant people.
However, current access control models remain unsuitable due to lack of
personalization, adaptability and smartness to the handicap situation. In this
paper, we propose a novel adaptable access control model and its related
architecture in which the security policy is based on the handicap situation
analyzed from the monitoring of userss behavior in order to grant a service
using any assistive device within intelligent environment. the design of our
model is an ontology-learning and evolving security policy for predicting the
future actions of dependent people. This is reached by reasoning about
historical data, contextual data and user behavior according to the access
rules that are used in the inference engine to provide the right service
according to the users needs.


title:
Vitreous silica distends in helium gas: acoustic vs. static
  compressibilities

abstract:
  Sound velocities of vitreous silica are measured under He compression in the
pressure range 0-6 GPa by Brillouin light scattering. It is found that the
well-known anomalous maximum in the pressure dependence of the compressibility
is suppressed by He incorporation into the silica network. This shows that the
elastic anomaly relates to the collapse of the largest interstitial voids in
the structure. The huge difference between the static and the acoustic
compressibilities indicates that the amount of incorporated helium still
increases at 6 GPa.


title: Possible and Necessary Winner Problem in Social Polls

abstract:
  Social networks are increasingly being used to conduct polls. We introduce a
simple model of such social polling. We suppose agents vote sequentially, but
the order in which agents choose to vote is not necessarily fixed. We also
suppose that an agent's vote is influenced by the votes of their friends who
have already voted. Despite its simplicity, this model provides useful insights
into a number of areas including social polling, sequential voting, and
manipulation. We prove that the number of candidates and the network structure
affect the computational complexity of computing which candidate necessarily or
possibly can win in such a social poll. For social networks with bounded
treewidth and a bounded number of candidates, we provide polynomial algorithms
for both problems. In other cases, we prove that computing which candidates
necessarily or possibly win are computationally intractable.


title: Linear Multifractional Stable Motion: fine path properties

abstract:
  Linear Multifractional Stable Motion (LMSM), denoted by $\{Y(t):t\in\R\}$,
has been introduced by Stoev and Taqqu in 2004-2005, by substituting to the
constant Hurst parameter of a classical Linear Fractional Stable Motion (LFSM),
a deterministic function $H(\cdot)$ depending on the time variable $t$; we
always suppose $H(\cdot)$ to be continuous and with values in $(1/\al,1)$,
also, in general we restrict its range to a compact interval. The main goal of
our article is to make a comprehensive study of the local and asymptotic
behavior of $\{Y(t):t\in\R\}$; to this end, one needs to derive fine path
properties of $\{X(u,v) : (u,v)\in\R \times (1/\alpha,1)\}$, the field
generating the latter process (i.e. one has $Y(t)=X(t,H(t))$ for all $t\in\R$).
This leads us to introduce random wavelet series representations of $\{X(u,v) :
(u,v)\in\R \times (1/\alpha,1)\}$ as well as of all its pathwise partial
derivatives of any order with respect to $v$. Then our strategy consists in
using wavelet methods. Among other things, we solve a conjecture of Stoev and
Taqqu, concerning the existence for LMSM of a modification with almost surely
continuous paths; moreover we provides some bounds for the local H\"older
exponent of LMSM: namely, we obtain a quasi-optimal global modulus of
continuity for it, and also an optimal local one. It is worth noticing that,
even in the quite classical case of LFSM, the latter optimal local modulus of
continuity provides a new result which was unknown so far.


title:
Electrical and high-frequency properties of compensated GaN under
  electron streaming conditions

abstract:
  Conditions required for the streaming effect and the optical-phonon
transit-time resonance to take place in a compensated bulk GaN are analyzed in
detail. Monte Carlo calculations of the high-frequency differential electron
mobility are carried out. It is shown that the negative dynamic differential
mobility can be realized in the terahertz frequency range, at low lattice
temperatures of 30--77 K, and applied electric fields of 3--10 kV/cm. New
manifestations of the streaming effect are revealed, namely, the anisotropy of
the dynamic differential mobility and a specific behavior of the diffusion
coefficient in the direction perpendicular to the applied electric field. The
theory of terahertz radiation transmission through the structure with an
epitaxial GaN layer is developed. Conditions for the amplification of
electromagnetic waves in the frequency range of 0.5--2 THz are obtained. The
polarization dependence of the radiation transmission coefficient through the
structure in electric fields above 1 kV/cm is found.


title: Types et contragr\'edientes

abstract:
  Let G be a p-adic reductive group, and R an algebraically closed field. Let
us consider a smooth representation of G on an R-vector space V. Fix an open
compact subgroup K of G and a smooth irreducible representation of K on a
finite-dimensional R-vector space W. The space of K-homomorphisms from W to V
is a right module over the intertwining algebra H(G,K,W). We examine how those
constructions behave when we pass to the contragredient representations of V
and W, and we give conditions under which the behaviour is the same as in the
case of complex representations. We take an abstract viewpoint and use only
general properties of G. In the last section, we apply this to the theory of
types for the group GL(n) and its inner forms over a non-Archimedean local
field.


title: Slow closure of denaturation bubbles in DNA: twist matters

abstract:
  The closure of long equilibrated denaturation bubbles in DNA is studied using
Brownian dynamics simulations. A minimal mesoscopic model is used where the
double-helix is made of two interacting bead-spring freely rotating strands,
with a non-zero torsional modulus in the duplex state, $\kappa_\phi=$200 to 300
kT. For DNAs of lengths N=40 to 100 base-pairs (bps) with a large initial
bubble in their middle, long closure times of 0.1 to 100 microseconds are
found. The bubble starts winding from both ends until it reaches a 10 bp
metastable state. The final closure is limited by three competing mechanisms
depending on $\kappa_\phi$ and N: arms diffusion until their alignment, bubble
diffusion along the DNA until one end is reached, or local Kramers process
(crossing over a torsional energy barrier). For clamped ends or long DNAs, the
closure occurs via this latter temperature activated mechanism, yielding for
the first time a good quantitative agreement with experiments.


title:
Linear fractional stable motion: a wavelet estimator of the $\al$
  parameter

abstract:
  Linear fractional stable motion, denoted by $\{X_{H,\al}(t)\}_{t\in \R}$, is
one of the most classical stable processes; it depends on two parameters $H\in
(0,1)$ and $\al\in (0,2)$. The parameter $H$ characterizes the self-similarity
property of $\{X_{H,\al}(t)\}_{t\in \R}$ while the parameter $\al$ governs the
tail heaviness of its finite dimensional distributions; throughout our article
we assume that the latter distributions are symmetric, that $H>1/\al$ and that
$H$ is known. We show that, on the interval $[0,1]$, the asymptotic behaviour
of the maximum, at a given scale $j$, of absolute values of the wavelet
coefficients of $\{X_{H,\al}(t)\}_{t\in \R}$, is of the same order as
$2^{-j(H-1/\al)}$; then we derive from this result a strongly consistent (i.e.
almost surely convergent) statistical estimator for the parameter $\al$.


title:
Transverse Waves in Nonlinearly Elastic Solids and the Milne-Pinney (or
  Ermakov) Equation

abstract:
  We establish a connection between the general equations of nonlinear
elastodynamics and the nonlinear ordinary differential equation of Pinney
[Proc. Amer. Math. Soc. 1 (1950) 681]. As a starting point, we use the exact
travelling wave solutions of nonlinear elasticity discovered by Carroll [Acta
Mechanica 3 (1967) 167]. The connection provides a method for finding new exact
and approximate dynamic solutions for neo-Hookean and Mooney-Rivlin solids, and
for the general third- and fourth-order elasticity models of incompressible
solids.


title:
Comparison of Proposed Data Dissemination Protocols for Sensor Networks
  Using J-Sim

abstract:
  A distinguishing characteristic of wireless sensor networks is the
opportunity to exploit characteristics of the application at lower layers. This
paper reports on the results of a simulation comparison of proposed data
dissemination protocols using the J-Sim simulator for the WSN protocols:
Forwarding Diffusion Data Dissemination(FDDDP), Decentralized Data
Dissemination(DDDP), Credit Broadcast Data Dissemination (CBDDP), Energy Aware
& Geographical Data Dissemination (EAGDDP) .Our performance provides useful
insights for the network designer such as which protocols (and design choices)
scale control traffic well, improve data delivery or reduce overall energy
consumption,improves routing overhead and maximizes the bandwidth utilization.
The static pre configuration of the cell size in DDDP, is one of the reasons
why DDDP exhibits larger routing overhead than FDDDP by 74.2% on average.
Although CBDDP produces approximately 94.6% smaller overhead than DDDP and
90.7% smaller than FDDDP, because of statically configured amount credit CBDDP
delivers on average 7.5 times more of the redundant data packets than DDDP and
FDDDP.EAGDDP improves the delivery by 80% on average and makes a balance of
energy consumption .We suggest that making these protocols truly self-learning
can significantly improve their performance.


title: Harnack type inequality for positive solution of some integral equation

abstract:
  In this paper, we establish some Harnack type inequalities satisfied by
positive solutions of nonlocal inhomogeneous equations arising in the
description of various phenomena ranging from population dynamics to
micro-magnetism. For regular domains, we also derive an inequality up to the
boundary. The main difficulty in such context lies in a precise control of the
solutions outside a compact set and the existence of local uniform estimates.
We overcome this problem by proving a contraction result which makes the $L^1$
norms of the solutions on two compact sets $\o_1\subset\subset\o_2$ equivalent.
We also construct the principal positive eigenfunctions associated to
particular nonlocal operators by using the corresponding Harnack type
inequalities.


title:
Multiple invariants conserving Runge-Kutta type methods for Hamiltonian
  problems

abstract:
  In a recent series of papers, the class of energy-conserving Runge-Kutta
methods named Hamiltonian BVMs (HBVMs) has been defined and studied. Such
methods have been further generalized for the efficient solution of general
conservative problems, thus providing the class of Line Integral Methods
(LIMs). In this paper we derive a further extension, which we name Enhanced
Line Integral Methods (ELIMs), more tailored for Hamiltonian problems, allowing
for the conservation of multiple invariants of the continuous dynamical system.
The analysis of the methods is fully carried out and some numerical tests are
reported, in order to confirm the theoretical achievements.


title:
Magneto-photoluminescence of charged excitons from MgZnO/ZnO
  heterojunctions

abstract:
  We report on the photoluminescence (PL) properties of MgZnO/ZnO
heterojunctions grown by plasma-assisted molecular-beam epitaxy. Influence of
the applied magnetic field (B) on the radiative recombination of the
two-dimensional electron gas (2DEG) is investigated up to 54 T. An increase in
magnetic field in the range of B <= 20 T results in a redshift in the PL.
Abrupt lineshape changes in the PL spectra are observed at higher magnetic
fields, in correlation with the integer quantum Hall states. We attempt to
interpret these features using the conventional model for the 2DEG-related PL
based on the transition between the 2DEG and a hole as well as a model taking a
bound state effect into account, i.e., a charged exciton. The comparison about
the adequateness of these models was made, being in favor of the charged
exciton model.


title:
Unveiling The Sigma-Discrepancy II: Revisiting the Evolution of ULIRGs &
  The Origin of Quasars

abstract:
  We present the first central velocity dispersions (sigma_o) measured from the
0.85 micron Calcium II Triplet (CaT) for 8 advanced (i.e. single nuclei) local
(z < 0.15) Ultraluminous Infrared Galaxies (ULIRGs). First, these measurements
are used to test the prediction that the "sigma-Discrepancy," in which the CaT
sigma_o is systematically larger than the sigma_o obtained from the 1.6 or 2.3
micron stellar CO band-heads, extends to ULIRG luminosities. Next, we combine
the CaT data with rest-frame I-band photometry obtained from archival Hubble
Space Telescope data and the Sloan Digital Sky Survey (SDSS) to derive
dynamical properties for the 8 ULIRGs. These are then compared to the dynamical
properties of 9,255 elliptical galaxies from the SDSS within the same redshift
volume and of a relatively nearby (z < 0.4) sample of 53 QSO host galaxies. A
comparison is also made between the I-band and H-band dynamical properties of
the ULIRGs. We find four key results: 1) the sigma-Discrepancy extends to ULIRG
luminosities; 2) at I-band ULIRGs lie on the Fundamental Plane (FP) in a region
consistent with the most massive elliptical galaxies and not low-intermediate
mass ellipticals as previously reported in the near-infrared; 3) the I-band M/L
of ULIRGs are consistent with an old stellar population, while at H-band ULIRGs
appear significantly younger and less massive; and 4) we derive an I-band
Kormendy Relation from the SDSS ellipticals and demonstrate that ULIRGs and QSO
host galaxies are dynamically similar.


title:
Low frequency optical conductivity in graphene and in other
  scale-invariant two-band systems

abstract:
  We investigate optical transitions of non-interacting electron systems
consisting of two symmetric energy bands touching each other at the Fermi
energy (e.g. graphene at half filling). Optical conductivity is obtained using
Kubo formula at zero temperature. We show that for particles whose pseudospin
direction is determined solely by the direction of their momentum, the optical
conductivity has power law frequency dependence with the exponent $(d-2)/z$
where $d$ is the dimension of the system and $z$ is the dynamical exponent.
According to our result two-dimensional systems with the above pseudospin
characteristics always exhibit frequency-independent optical conductivity.


title:
Dynamics of the sub-Ohmic spin-boson model: a time-dependent variational
  study

abstract:
  The Dirac-Frenkel time-dependent variation is employed to probe the dynamics
of the zero temperature sub-Ohmic spin-boson model with strong friction
utilizing the Davydov D1 ansatz. It is shown that initial conditions of the
phonon bath have considerable influence on the dynamics. Counterintuitively,
even in the very strong coupling regime, quantum coherence features still
manage to survive under the polarized bath initial condition, while such
features are absent under the factorized bath initial condition. In addition, a
coherent-incoherent transition is found at a critical coupling strength alpha ~
0.1 for s=0.25 under the factorized bath initial condition. We quantify how
faithfully our ansatz follows the Schr\"{o}dinger equation, finding that the
time-dependent variational approach is robust for strong dissipation and deep
sub-Ohmic baths (s<<1).


title: Luminosity profiles and sizes of massive star clusters in NGC 7252

abstract:
  We present Hubble Space Telescope (HST) Wide-Field Camera 3 (WFC3) images of
the merger remnant NGC 7252. In particular, we focus on the surface brightness
profiles and effective radii, Reff, of 36 young massive clusters (YMCs) within
the galaxy. All the clusters have masses exceeding 10^5 Msun and are, despite
the 64 Mpc distance to the galaxy, (partly) resolved on the HST images.
Effective radii can be measured down to ~2.5 pc, and the largest clusters have
Reff approaching 20 pc. The median Reff of our sample clusters is ~6-7 pc,
which is larger than typical radii of YMCs (~2.5 pc). This could be due to our
sample selection (only selecting resolved sources) or to an intrinsic
mass--radius relation within the cluster population. We find at least three
clusters that have power-law profiles of the Elson, Fall, & Freeman (1987,
"EFF") type extending out to >150 pc. Among them are the two most massive
clusters, W3 and W30, which have profiles that extend to at least 500 and 250
pc, respectively. Despite their extended profiles, the effective radii of the
three clusters are 17.2, 12.6 and 9.1 pc for W3, W26 and W30, respectively. We
compare these extended profiles with those of YMCs in the LMC (R136 in 30 Dor),
the Antennae galaxies (Knot S) and in the nearby spiral galaxy NGC 6946.
Extended profiles seem to be a somewhat common feature, even though many nearby
YMCs show distinct truncations. A continuous distribution between these two
extremes, i.e. truncated or extremely extended, is the most likely
interpretation. We suggest that the presence or absence of an extended envelope
in {\em very young clusters} may be due to the gas distribution of the
proto-cluster giant molecular cloud, in particular if the proto-cluster core
becomes distinct from the surrounding gas before star formation begins.


title: On high-dimensional acyclic tournaments

abstract:
  We study a high-dimensional analog for the notion of an acyclic (aka
transitive) tournament. We give upper and lower bounds on the number of
$d$-dimensional $n$-vertex acyclic tournaments. In addition, we prove that
every $n$-vertex $d$-dimensional tournament contains an acyclic subtournament
of $\Omega(\log^{1/d}n)$ vertices and the bound is tight. This statement for
tournaments (i.e., the case $d=1$) is a well-known fact. We indicate a
connection between acyclic high-dimensional tournaments and Ramsey numbers of
hypergraphs. We investigate as well the inter-relations among various other
notions of acyclicity in high-dimensional to tournaments. These include
combinatorial, geometric and topological concepts.


title:
The analysis of cross-sections of proton and deuteron induced reactions
  on tin isotopes at the beam energy of 3.65 GeV/nucleon

abstract:
  In the given paper the total inelastic cross-sections of the reactions of
protons and deuterons on nuclear targets of enriched tin isotopes were
compared. The factorization of cross-sections of reactions was discussed.
Furthermore, the comparison of theoretical estimations on total inelastic
cross-sections with corresponding experimental ones was made.


title: The Geometry of Conventionality

abstract:
  There is a venerable position in the philosophy of space and time that holds
that the geometry of spacetime is conventional, provided one is willing to
postulate a "universal force field". Here we ask a more focused question,
inspired by this literature: in the context of our best classical theories of
space and time, if one understands "force" in the standard way, can one
accommodate different geometries by postulating a new force field? We argue
that the answer depends on one's theory. In Newtonian gravitation the answer is
"yes"; in relativity theory, it is "no".


title: A Tur\'an-type problem on degree sequence

abstract:
  Given $p\geq 0$ and a graph $G$ whose degree sequence is
$d_1,d_2,\ldots,d_n$, let $e_p(G)=\sum_{i=1}^n d_i^p$. Caro and Yuster
introduced a Tur\'an-type problem for $e_p(G)$: given $p\geq 0$, how large can
$e_p(G)$ be if $G$ has no subgraph of a particular type. Denote by $ex_p(n,H)$
the maximum value of $e_p(G)$ taken over all graphs with $n$ vertices that do
not contain $H$ as a subgraph. Clearly, $ex_1(n,H)=2ex(n,H)$, where $ex(n,H)$
denotes the classical Tur\'an number, i.e., the maximum number of edges among
all $H$-free graphs with $n$ vertices. Pikhurko and Taraz generalize this
Tur\'an-type problem: let $f$ be a non-negative increasing real function and
$e_f(G)=\sum_{i=1}^n f(d_i)$, and then define $ex_f(n,H)$ as the maximum value
of $e_f(G)$ taken over all graphs with $n$ vertices that do not contain $H$ as
a subgraph. Observe that $ex_f(n,H)=ex(n,H)$ if $f(x)=x/2$,
$ex_f(n,H)=ex_p(n,H)$ if $f(x)=x^p$. Bollob\'as and Nikiforov mentioned that it
is important to study concrete functions. They gave an example
$f(x)=\phi(k)={x\choose k}$, since $\sum_{i=1}^n{d_i\choose k}$ counts the
$(k+1)$-vertex subgraphs of $G$ with a dominating vertex.
  Denote by $T_r(n)$ the $r$-partite Tur\'an graph of order $n$. In this paper,
using the Bollob\'as--Nikiforov's methods, we give some results on
$ex_{\phi}(n,K_{r+1})$ $(r\geq 2)$ as follows: for $k=1,2$,
$ex_\phi(n,K_{r+1})=e_\phi(T_r(n))$; for each $k$, there exists a constant
$c=c(k)$ such that for every $r\geq c(k)$ and sufficiently large $n$,
$ex_\phi(n,K_{r+1})=e_\phi(T_r(n))$; for a fixed $(r+1)$-chromatic graph $H$
and every $k$, when $n$ is sufficiently large, we have
$ex_\phi(n,H)=e_\phi(n,K_{r+1})+o(n^{k+1})$.


title:
Scalar and fermionic vacuum currents in de Sitter spacetime with compact
  dimensions

abstract:
  Vacuum expectation values (VEVs) of the current densities for charged scalar
and Dirac spinor fields are investigated in (D+1)-dimensional de Sitter (dS)
spacetime with toroidally compactified spatial dimensions. Along compact
dimensions we impose quasiperiodicity conditions with arbitrary phases. In
addition, the presence of a classical constant gauge field is assumed. The VEVs
of the charge density and of the components for the current density along
noncompact dimensions vanish. The gauge field leads to Aharonov-Bohm-like
oscillations of the components along compact dimensions as functions of the
magnetic flux. For small values of the comoving length of a compact dimension,
compared with the dS curvature scale, the current density is related to the
corresponding current in the Minkowski spacetime by a conformal relation. For
large values of the comoving length and for a scalar field, depending on the
mass of the field, two different regimes are realized with the monotonic and
oscillatory damping of the current density. For a massive spinor field, the
decay of the current density is always oscillatory. In supersymmetric models on
the background of Minkowski spacetime with equal number of scalar and fermionic
degrees of freedom and with the same phases in the periodicity conditions, the
total current density vanishes due to the cancellation between the scalar and
fermionic parts. The background gravitational field modifies the current
densities for scalar and fermionic fields in different ways and for massive
fields there is no cancellation in the dS spacetime.


title:
Hopf Algebras, Distributive (Laplace) Pairings and Hash Products: A
  unified approach to tensor product decompositions of group characters

abstract:
  We show for bicommutative graded connected Hopf algebras that a certain
distributive (Laplace) subgroup of the convolution monoid of 2-cochains
parameterizes certain well behaved Hopf algebra deformations. Using the Laplace
group, or its Frobenius subgroup, we define higher derived hash products, and
develop a general theory to study their main properties. Applying our results
to the (universal) bicommutative graded connected Hopf algebra of symmetric
functions, we show that classical tensor product and character decompositions,
such as those for the general linear group, mixed co- and contravariant or
rational characters, orthogonal and symplectic group characters, Thibon and
reduced symmetric group characters, are special cases of higher derived hash
products. In the Appendix we discuss a relation to formal group laws.


title:
A Fast Learning Algorithm for Image Segmentation with Max-Pooling
  Convolutional Networks

abstract:
  We present a fast algorithm for training MaxPooling Convolutional Networks to
segment images. This type of network yields record-breaking performance in a
variety of tasks, but is normally trained on a computationally expensive
patch-by-patch basis. Our new method processes each training image in a single
pass, which is vastly more efficient.
  We validate the approach in different scenarios and report a 1500-fold
speed-up. In an application to automated steel defect detection and
segmentation, we obtain excellent performance with short training times.


title: Viscous potential flow analysis of peripheral heavy ion collisions

abstract:
  The conditions for the development of a Kelvin-Helmholtz Instability (KHI)
for the Quark-gluon Plasma (QGP) flow in a peripheral heavy-ion collision is
investigated. The projectile and target side particles are separated by an
energetically motivated hypothetical surface, characterized with a
phenomenological surface tension. In such a view, a classical potential flow
approximation is considered and the onset of the KHI is studied. The growth
rate of the instability is computed as function of phenomenological parameters
characteristic for the QGP fluid: viscosity, surface tension and flow layer
thickness.


title: Loop Anomalies in the Causal Approach

abstract:
  We consider gauge models in the causal approach and study one-loop
contributions to the chronological products and the anomalies they produce. We
prove that in order greater than 4 there are no one-loop anomalies. Next we
analyze one-loop anomalies in the second and third order of the perturbation
theory. We prove that the even parity contributions (with respect to parity) do
not produce anomalies; for the odd parity contributions we reobtain the
well-known result.


title: Spectral states in Be/X-ray pulsars

abstract:
  In the last quarter of a century, a unified characterization of the spectral
evolution of low-mass X-ray binaries, both containing a neutron star and a
black hole, was possible. In this context, the notion of source states
characterizing the X-ray emission from black-hole binaries and neutron-star
low-mass X-ray binaries revealed to be a very useful tool to disentangle the
complex spectral and aperiodic phenomenology displayed by those classes of
accreting objects. Be/X-ray binaries constitute another major class of
transient accreting binaries, for which very little work has been done on the
correlated timing and spectral variability. Especially, no definition of source
states exists for this class, in spite of their highly variable X-ray emission.
When active, Be/X-ray binaries are among the brightest objects in the X-ray sky
and are characterized by dramatic variability in brightness on timescales
ranging from seconds to years. It is then worth it to ask whether a definition
of spectral states is possible for these systems. In this work, we try to
address such a question, investigating whether accreting X-ray pulsars display
source states and characterizing those states through their spectral
properties. Our results show that Be/X-ray pulsars trace two different branches
in their hardness-intensity diagram: the horizontal branch, a low-intensity
state, and the diagonal branch, a high-intensity state that only appears when
the X-ray luminosity exceeds a critical limit. We propose that the two branches
are the phenomenological signature of two different accretion modes -- in
agreement with recently proposed models -- depending on whether the luminosity
of the source is above or below a critical value.


title:
Optical instabilities in three-level lambda and V system inside
  double-cavity

abstract:
  We obtain optical instabilities in all-optical bistable systems arising from
competing cooperative pathways at low input light levels. In particular for
three-level atomic systems in the lambda and V configuration interacting with
two independent cavity modes, we identify the necessary conditions related to
the incoherent pathways required to obtain instabilities. The instabilities
arise when atomic states involved in the bistable transition are leaky and have
substantial population, where the incoherent processes adversely affect the
cooperative behavior of the atomic ensemble.


title: On a normality criterion of S. Mandelbrojt

abstract:
  Extension of classical Mandelbrojt's criterion for normality of a family of
holomorphic zero-free functions of several complex variables is given. We show
that a family of holomorphic functions of several complex variables whose
corresponding Levi form are uniformly bounded away from zero is normal.


title:
Evidence of Strong Correlations and Coherence-Incoherence Crossover in
  the Iron Pnictide Superconductor KFe2As2

abstract:
  Using resistivity, heat-capacity, thermal-expansion, and susceptibility
measurements we study the normal-state behavior of KFe2As2. We find that both
the Sommerfeld coefficient gamma = 103 mJ mol-1 K-2 and the Pauli
susceptibility chi = 4x10-4 are strongly enhanced, which confirm the existence
of heavy quasiparticles inferred from previous de Haas-van Alphen and ARPES
experiments. We discuss this large enhancement using a Gutzwiller slave-boson
mean-field calculation, which reveals the proximity of KFe2As2 to an
orbital-selective Mott transition. The temperature dependence of the magnetic
susceptibility and the thermal expansion provide strong experimental evidence
for the existence of a coherence-incoherence crossover, similar to what is
found in heavy fermion and ruthenate compounds, due to Hund's coupling between
orbitals.


title: Fairness in Collision-Free WLANs

abstract:
  CSMA/ECA is a contention protocol that makes it possible to construct a
collision-free schedule by using a deterministic backoff after successful
transmissions. In this paper, we further enhance the CSMA/ECA protocol with two
properties that allows to fairly accommodate a large number of contenders in a
collision-free schedule. The first property, called hysteresis, instructs the
contenders not to reset their contention window after successful transmissions.
Thanks to hysteresis, the protocol sustains a high throughput regardless of the
number of contenders. The second property, called fair-share, preserves
fairness when different nodes use different contention windows. We present
simulations results that evidence how these properties account for performance
gains that go even further beyond CSMA/CA.


title:
Antikaons and higher order couplings in relativistic-mean field study of
  neutron stars

abstract:
  We investigate the role of higher order couplings, along with the
condensation of antikaons ($K^-$ and $\bar K^0$), on the properties of neutron
star (NS). We employ extended versions of the relativistic mean-field model, in
which kaon-nucleon and nucleon-nucleon interactions are taken on the same
footing. We find that the onset of condensation of $K^-$ and $\bar K^0$ highly
depends not only on the strength of optical potential but also on the new
couplings. The presence of antikaons leads to a softer equation of state and
makes the neutron star core symmetric and lepton-deficient. We show that these
effects strongly influence the mass-radius relation as well as the composition
of neutron star. We also show that the recently observed 1.97$\pm$.04 solar
mass NS can be explained in three ways: (i) a stiffer EoS with both antikaons,
(ii) a relatively soft EoS with $K^-$ and (iii) a softer EoS without antikaons.


title: Sharp deviation bounds for quadratic forms

abstract:
  This note presents sharp inequalities for deviation probability of a general
quadratic form of a random vector \(\xiv\) with finite exponential moments. The
obtained deviation bounds are similar to the case of a Gaussian random vector.
The results are stated under general conditions and do not suppose any special
structure of the vector \(\xiv\). The obtained bounds are exact
(non-asymptotic), all constants are explicit and the leading terms in the
bounds are sharp.


title: Fast Image Scanning with Deep Max-Pooling Convolutional Neural Networks

abstract:
  Deep Neural Networks now excel at image classification, detection and
segmentation. When used to scan images by means of a sliding window, however,
their high computational complexity can bring even the most powerful hardware
to its knees. We show how dynamic programming can speedup the process by orders
of magnitude, even when max-pooling layers are present.


title: Blind post-processing for the unbalanced BB84

abstract:
  For the realization of quantum key distribution, it is important to
investigate its security based on a mathematical model that captures properties
of the actual devices used by the legitimate users. Recently, Ferenczi, et. al.
(Phys. Rev. A 86 042327 (2012)) pointed out potential influences that the
losses in phase modulators and/or the unbalance in the transmission rate of
beam splitters may have on the security of the phase-encoded BB84 and analyzed
the security of this scheme, which is called the unbalanced BB84. In this
paper, we ask whether blindly applying the post-processing of the balanced BB84
to the unbalanced BB84 would lead to an insecure key or not, and we conclude
that we can safely distill a secure key even with this post-processing. It
follows from our proof that as long as the unbalances are basis-independent,
our conclusion holds even if the unbalances are unknown and fluctuate in time.


title:
The Supergiant Fast X-ray Transient with the shortest orbital period:
  Suzaku observes one orbit in IGRJ16479-4514

abstract:
  The eclipsing hard X-ray source IGR J16479-4514 is the Supergiant Fast X-ray
Transient (SFXT) with the shortest orbital period (3.32 days). This allowed us
to perform a 250 ks long X-ray observation with Suzaku in 2012 February,
covering most of its orbit, including the eclipse egress. Outside the eclipse,
the source luminosity is around a few 1E34erg/s. The X-ray spectrum can be fit
with an absorbed power law together with a neutral iron emission line at 6.4
keV. The column density is constant at 1E23 cm-2 outside the X-ray eclipse.
During the eclipse it is lower, consistent with a scattering origin for the low
X-ray emission during the eclipse by the supergiant companion wind. The
scattered X-ray emission during the X-ray eclipse is used to directly probe the
density of the companion wind at the orbital separation, resulting in 7E-14
g/cm3, which translates into a ratio Mdot_w/v_terminal = 7E-17 solar masses/km
of the wind mass loss rate to the wind terminal velocity. This ratio, assuming
reasonable terminal velocities in the range 500-3000 km/s, translates into an
accretion luminosity two orders of magnitude higher than that observed. We
conclude that a mechanism reducing the accretion rate onto the compact object
is at work, likely due to the neutron star magnetosphere.


title: Picard-Vessiot theory for real partial differential fields

abstract:
  We prove the existence of real Picard-Vessiot extensions for real partial
differential fields with real closed field of constants. We establish a Galois
correspondence theorem for these Picard-Vessiot extensions and characterize
real Liouville extensions of real partial differential fields.


title:
Three-dimensional artificial neural network model of the dayside
  magnetopause

abstract:
  Artificial Neural Networks (ANN) from package NeuroShell 2 are applied for
modeling of dayside magnetopause. The model data set is based on the
magnetopause crossings and on the corresponding hour-averaged measurements of
solar wind plasma and interplanetary magnetic field. ANN model represents 3D
shape and size of the dayside magnetopause in dependence on solar wind dynamic
pressure, Bz and By components of interplanetary magnetic field. The model
permits firstly to describe dynamics of the magnetic cusp and global asymmetry
of the dayside magnetopause under wide range of the external conditions.
Slightly change of the magnetopause size with change of By absolute value is
presented quantitatively in the form of analytical expression. ANN model shows
three regimes of the magnetopause dynamics that controlled by Bz component:
pressure balance regime (Bz>0 nT), reconnection regime (0>Bz>-10 nT) and regime
of reconnection saturation (Bz<-10 nT). Three different regimes of magnetopause
dynamics at the subsolar point are described by modified pressure balance
equation obtained from ANN model.


title: Dynamics of test particles in thin-shell wormhole spacetimes

abstract:
  Geodesic motion in traversable Schwarzschild and Kerr thin-shell wormholes
constructed by the cut-and-paste method introduced by Visser (1989 Nucl. Phys.
B 328 203; 1995 Wormholes: from Einstein to Hawking (Woodbury, MN: American
Institute of Physics)) is studied. The orbits are calculated exactly in terms
of elliptic functions and visualized with the help of embedding diagrams.


title:
Dynamical Structure Factor of Fulde-Ferrell-Larkin-Ovchinnikov
  Superconductors

abstract:
  Superconductor with a spatially-modulated order parameter is known as
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconductor. Using the
time-dependent Ginzburg-Landau (TDGL) formalism we have theoretically studied
the temporal behaviour of the equal-time correlation function, or the structure
factor, of a FFLO superconductor following a sudden quench from the unpaired,
or normal, state to the FFLO state. We find that quenching into the ordered
FFLO phase can reveal the existence of a line in the mean-field phase diagram
which cannot be accessed by static properties.


title:
Multi-phonon relaxation and generation of quantum states in a nonlinear
  mechanical oscillator

abstract:
  The dissipative quantum dynamics of an anharmonic oscillator is investigated
theoretically in the context of carbon-based nano-mechanical systems. In the
short-time limit, it is known that macroscopic superposition states appear for
such oscillators. In the long-time limit, single and multi-phonon dissipation
lead to decoherence of the non-classical states. However, at zero temperature,
as a result of two-phonon losses the quantum oscillator eventually evolves into
a non-classical steady state. The relaxation of this state due to thermal
excitations and one-phonon losses is numerically and analytically studied. The
possibility of verifying the occurrence of the non-classical state is
investigated and signatures of the quantum features arising in a ring-down
setup are presented. The feasibility of the verification scheme is discussed in
the context of quantum nano-mechanical systems.


title:
Studies of atomic diffusion in Ni-Pt solid solution by x-ray photon
  correlation spectroscopy

abstract:
  Atomic scale x-ray photon correlation spectroscopy (aXPCS) was used to study
atomic diffusion in the Ni97 Pt3 solid solution with both a single crystal and
a polycrystalline sample. Different jump diffusion models are discussed using
experimental results and Monte Carlo simulations. The sensitivity of aXPCS
experiments to short-range order (in this case governed by a strong Pt-Pt
repulsive force) is demonstrated. The activation energy of 2.93(10) eV as well
as diffusivities in the range of 10-23 m2 s-1 at 830 K agree very well with the
results of tracer diffusion studies at much higher temperatures.


title: Quantum bath-driven decoherence of mixed spin systems

abstract:
  The decoherence of mixed electron-nuclear spin qubits is a topic of great
current importance, but understanding is still lacking: while important
decoherence mechanisms for spin qubits arise from quantum spin bath
environments with slow decay of correlations, the only analytical framework for
explaining observed sharp variations of decoherence times with magnetic field
is based on the suppression of classical noise. Here we obtain a general
expression for decoherence times of the central spin system which exposes
significant differences between quantum-bath decoherence and decoherence by
classical field noise. We perform measurements of decoherence times of bismuth
donors in natural silicon using both electron spin resonance (ESR) and nuclear
magnetic resonance (NMR) transitions, and in both cases find excellent
agreement with our theory across a wide parameter range. The universality of
our expression is also tested by quantitative comparisons with previous
measurements of decoherence around `optimal working points' or `clock
transitions' where decoherence is strongly suppressed. We further validate our
results by comparison to cluster expansion simulations.


title: Painlev\'e kernels in Hermitian matrix models

abstract:
  After reviewing the Hermitian one matrix model, we will give a brief
introduction to the Hermitian two matrix model and present a summary of some
recent results on the asymptotic behavior of the two matrix model with a
quartic potential. In particular, we will discuss a limiting kernel in the
quartic/quadratic case that is constructed out of a $4\times 4$ Riemann-Hilbert
problem related to Painlev\'e II equation. Also an open problem will be
presented.


title: Comment on "Causality-violating Higgs singlets at the LHC"

abstract:
  The spacetime of Ho and Weiler [Phys. Rev. D {\bf 87}, 045004 (2013)]
supposedly admitting closed timelike curves (CTCs) is flat Minkowski spacetime
with a compactified coordinate and can only contain CTCs if the compact
direction is chosen to be timelike. This case of a "periodic time" is probably
the simplest example of a causality-violating spacetime; it trivially satisfies
all energy conditions usually assumed in general relativity, and its geodesics
are just straight lines. Its relevance for phenomenology of the LHC, on the
other hand, depends on consistency with observational constraints on gravity,
as is mentioned in general but not discussed in any detail by Ho and Weiler. We
verify a basic consistency check for stationary sources.


title: Nonlinearity, Proper Actions and Equivariant Stable Cohomotopy

abstract:
  In this article we extend the classical definitions of equivariant cohomotopy
theory to the setting of proper actions of Lie groups. We combine methods
originally developed in the analysis of nonlinear differential equations,
mainly in connection with Leray-Schauder theory, and on the other hand from
developments of equivariant $K$-Theory by N.C. Phillips. We prove the
correspondence with a previous construction of W. L\"uck by constructing an
index.
  As an illustration of these methods, we introduce a Burnside ring defined in
analytical terms. With this definition, we extend a weak version of the Segal
Conjecture to a certain family of Lie groups and comment the relation to an
invariant in Gauge Theory, due to Bauer and Furuta.


title: GEM applications outside high energy physics

abstract:
  From its invention in 1997, the Gas Electron Multiplier has been applied in
nuclear and high energy physics experiments. Over time however, other
applications have also exploited the favorable properties of GEMs. The use of
GEMs in these applications will be explained in principle and practice.
  This paper reviews applications in research, beam instrumentation and
homeland security. The detectors described measure neutral radiations such as
photons, x-rays, gamma rays and neutrons, as well as all kinds of charged
radiation. This paper provides an overview of the still expanding range of
possibilities of this versatile detector concept.


title: On the density profile of the globular cluster M92

abstract:
  We present new number density and surface brightness profiles for the
globular cluster M92 (NGC 6341). These profiles are calculated from optical
images collected with the CCD mosaic camera MegaCam at the
Canada-France-Hawaii-Telescope and with the Advanced Camera for Surveys on the
Hubble Space Telescope. The ground-based data were supplemented with the Sloan
Digital Sky Survey photometric catalog. Special care was taken to discriminate
candidate cluster stars from field stars and to subtract the background
contamination from both profiles. By examining the contour levels of the number
density, we found that the stellar distribution becomes clumpy at radial
distances larger than about 13 arcminutes, and there is no preferred
orientation of contours in space. We performed detailed fits of King and Wilson
models to the observed profiles. The best-fit models underestimate the number
density inside the core radius. Wilson models better represent the
observations, in particular in the outermost cluster regions: the good global
agreement of these models with the observations suggests that there is no need
to introduce an extra-tidal halo to explain the radial distribution of stars at
large radial distances. The best-fit models for the number density and the
surface brightness profiles are different, even though they are based on the
same observations. Additional tests support the evidence that this fact
reflects the difference in the radial distribution of the stellar tracers that
determine the observed profiles (main sequence stars for the number density,
bright evolved stars for the surface brightness).


title: Congruences for Domb and Almkvist-Zudilin numbers

abstract:
  In this paper we prove some transformation formulae for congruences modulo a
prime and deduce some congruences for Domb numbers and Almkvist-Zudilin
numbers. We also pose some conjectures on congruences modulo prime powers.


title:
Robustness of Exponential Dichotomies of Boundary-Value Problems for
  General First-Order Hyperbolic Systems

abstract:
  We examine robustness of exponential dichotomies of boundary value problems
for general linear first-order one-dimensional hyperbolic systems. The boundary
conditions are supposed to be of types ensuring smoothing solutions in finite
time, which includes reflection boundary conditions. We show that the dichotomy
survives in the space of continuous functions under small perturbations of all
coefficients in the differential equations.


title: Fractional Order Optimal Control Problems with Free Terminal Time

abstract:
  We consider fractional order optimal control problems in which the dynamic
control system involves integer and fractional order derivatives and the
terminal time is free. Necessary conditions for a state/control/terminal-time
triplet to be optimal are obtained. Situations with constraints present at the
end time are also considered. Under appropriate assumptions, it is shown that
the obtained necessary optimality conditions become sufficient. Numerical
methods to solve the problems are presented, and some computational simulations
are discussed in detail.


title: Maximal near-field radiative heat transfer between two plates

abstract:
  A parametric study of Drude and Lorentz models performances in maximizing
near-field radiative heat transfer between two semi-infinite planes separated
by nanometric distances at room temperature is presented in this paper. Optimal
parameters of these models that provide optical properties maximizing the
radiative heat flux are reported and compared to real materials usually
considered in similar studies, silicon carbide and heavily doped silicon in
this case. Results are obtained by exact and approximate (in the extreme
near-field regime and the electrostatic limit hypothesis) calculations. The two
methods are compared in terms of accuracy and CPU resources consumption. Their
differences are explained according to a mesoscopic description of near-field
radiative heat transfer. Finally, the frequently assumed hypothesis which
states a maximal radiative heat transfer when the two semi-infinite planes are
of identical materials is numerically confirmed. Its subsequent practical
constraints are then discussed.


title: The Worldsheet Perspective of T-duality Symmetry in String Theory

abstract:
  The purpose of this article is to present a pedagogical review of T-dualityin
in string theory. The evolution of the closed string is envisaged on the
worldsheet in the presence of its massless excitations. The duality symmetry is
studied when some of the spacial coordinates are compactified on d-dimensional
torus, $T^d$. The known results are reviewed to elucidate that equations of
motion for the compact coordinates are $O(d,d)$ covariant, $d$ being the number
of compact directions. Next, the vertex operators of excited massive levels are
considered in a simple compactification scheme. It is shown that the vertex
operators for each massive level can be cast in a T-duality invariant form in
such a case. Subsequently, the duality properties of superstring is
investigated in the NSR formulation for the massless backgrounds such as
graviton and antisymmetric tensor. The worldsheet superfield formulation is
found to be very suitable for our purpose. The Hassan-Sen compactification is
adopted and it is shown that the worldsheet equations of motion for compact
superfields to be very suitable for our purpose. The Hassan-Sen
compactification is adopted and it is shown that the worldsheet equations of
motion for compact superfields are $O(d,d)$ covariant when the backgrounds are
independent of superfields along compact directions. The vertex operators for
excited levels are presented in the NS-NS sector and it is shown that they can
be cast in T-duality invariant form for the case of Hassan-Sen compactification
scheme. An illustrative example is presented to realize our proposal.


title: Vibrational transition moments of CH$_4$ from first principles

abstract:
  A new nine-dimensional (9D), \textit{ab initio} electric dipole moment
surface (DMS) of methane in its ground electronic state is presented. The DMS
is computed using an explicitly correlated coupled cluster CCSD(T)-F12 method
in conjunction with an F12-optimized correlation consistent basis set of the
TZ-family. A symmetrized molecular bond representation is used to parameterise
the 9D DMS in terms of sixth-order polynomials. Vibrational transition moments
as well as band intensities for a large number of IR-active vibrational bands
of $^{12}$CH$_4$ are computed by vibrationally averaging the \textit{ab initio}
dipole moment components. The vibrational wavefunctions required for these
averages are computed variationally using the program TROVE and a new
`spectroscopic' $^{12}$CH$_4$ potential energy surface. The new DMS will be
used to produce a hot line list for $^{12}$CH$_4$.


title: Bayesian Model Averaging in Astrophysics: A Review

abstract:
  We review the use of Bayesian Model Averaging in astrophysics. We first
introduce the statistical basis of Bayesian Model Selection and Model
Averaging. We discuss methods to calculate the model-averaged posteriors,
including Markov Chain Monte Carlo (MCMC), nested sampling, Population Monte
Carlo, and Reversible Jump MCMC. We then review some applications of Bayesian
Model Averaging in astrophysics, including measurements of the dark energy and
primordial power spectrum parameters in cosmology, cluster weak lensing and
Sunyaev-Zel'dovich effect data, estimating distances to Cepheids, and
classifying variable stars.


title: Binary Linear Codes, Dimers and Hypermatrices

abstract:
  We show that the weight enumerator of any binary linear code is equal to the
permanent of a 3-dimensional hypermatrix (3-matrix). We also show that each
permanent is a determinant of a 3-matrix. As an application we write the dimer
partition function of a finite 3-dimensional cubic lattice as the determinant
of the vertex-adjacency 3-matrix of a 2-dimensional simplicial complex which
preserves the natural embedding of the cubic lattice.


title:
Infinite horizon optimal control of forward-backward stochastic
  differential equations with delay

abstract:
  We consider a problem of optimal control of an infinite horizon system
governed by forward-backward stochastic differential equations with delay.
Sufficient and necessary maximum principles for optimal control under partial
information in infinite horizon are derived. We illustrate our results by an
application to a problem of optimal consumption with respect to recursive
utility from a cash flow with delay.


title: Self-localization of polariton condensates in periodic potentials

abstract:
  We predict the existence of novel spatially localized states of
exciton-polariton Bose-Einstein condensates in semiconductor microcavities with
fabricated periodic in-plane potentials. Our theory shows that, under the
condition of continuous off-resonant pumping and losses associated with
polariton decay, localization is observed for a wide range of optical pump
parameters due to effective potentials self-induced by the polariton flows in
the spatially periodic system. We reveal that the self-localization of
exciton-polaritons in the lattice may occur both in the gaps and bands of the
single-particle linear spectrum, and is dominated by the effects of gain and
dissipation rather than the applied potential, in sharp contrast to the
conservative condensates of ultracold alkali atoms.


title:
Tight-binding branch-point energies and band offsets for cubic InN, GaN,
  AlN and AlGaN alloys

abstract:
  Starting with empirical tight-binding band structures, the branch-point (BP)
energies and resulting valence band offsets (VBOs) for the zincblende phase of
InN, GaN and AlN are calculated from their k-averaged midgap energy.
Furthermore, the directional dependence of the BPs of GaN and AlN is discussed
using the Green's function method of Tersoff. We then show how to obtain the
BPs for binary semiconductor alloys within a band-diagonal representation of
the coherent potential approximation (CPA) and apply this method to cubic AlGaN
alloys. The resulting band offsets show good agreement to available
experimental and theoretical data from the literature. Our results can be used
to determine the band alignment in isovalent heterostructures involving pure
cubic III-nitrides or AlGaN alloys for arbitrary concentrations.


title:
Uncovering the Wider Structure of Extreme Right Communities Spanning
  Popular Online Networks

abstract:
  Recent years have seen increased interest in the online presence of extreme
right groups. Although originally composed of dedicated websites, the online
extreme right milieu now spans multiple networks, including popular social
media platforms such as Twitter, Facebook and YouTube. Ideally therefore, any
contemporary analysis of online extreme right activity requires the
consideration of multiple data sources, rather than being restricted to a
single platform. We investigate the potential for Twitter to act as a gateway
to communities within the wider online network of the extreme right, given its
facility for the dissemination of content. A strategy for representing
heterogeneous network data with a single homogeneous network for the purpose of
community detection is presented, where these inherently dynamic communities
are tracked over time. We use this strategy to discover and analyze persistent
English and German language extreme right communities.


title: Terrorist Network: Towards An Analysis

abstract:
  Terrorist network is a paradigms to understand the terrorism. The terrorist
involves a lot of people, and among them are involved as perpetrators, but on
the contrary it is very difficult to know who they are caused by lack of
information. Network structure is used to reveal other things about the
terrorist beyond the ability of social sciences.


title: Invertibility in groupoid C*-algebras

abstract:
  Given a second-countable, Hausdorff, \'etale, amenable groupoid G with
compact unit space, we show that an element a in C*(G) is invertible if and
only if \lambda_x(a) is invertible for every x in the unit space of G, where
\lambda_x refers to the "regular representation" of C*(G) on l_2(G_x). We also
prove that, for every a in C*(G), there exists some x in G^{(0)} such that
||a|| = ||\lambda_x(a)||.


title: Galois functors and generalised Hopf modules

abstract:
  As shown in a previous paper by the same authors, the theory of Galois
functors provides a categorical framework for the characterisation of bimonads
on any category as Hopf monads and also for the characterisation of opmonoidal
monads on monoidal categories as right Hopf monads in the sense of Bruguieres
and Virelizier. Hereby the central part is to describe conditions under which a
comparison functor between the base category and the category of Hopf modules
becomes an equivalence (Fundamental Theorem).
  For monoidal categories, Aguiar and Chase extended the setting by replacing
the base category by a comodule category for some comonoid and considering a
comparison functor to generalised Hopf modules. For duoidal categories, Bohm,
Chen and Zhang investigated a comparison functor to the Hopf modules over a
bimonoid induced by the two monoidal structures given in such categories. In
both approaches fundamental theorems are proved and the purpose of this paper
is to show that these can be derived from the theory of Galois functors.


title: Subalgebra depths within the path algebra of an acyclic quiver

abstract:
  Constraints are given on the depth of diagonal subalgebras in generalized
triangular matrix algebras. The depth of the top subalgebra B = A /rad A in a
finite, connected, acyclic quiver algebra A over an algebraically closed field
K is then computed. Also the depth of the primary arrow subalgebra 1K + rad A =
B in A is obtained. The two types of subalgebras have depths 3 and 4
respectively, independent of the number of vertices. An upper bound on depth is
obtained for the quotient of a subalgebra pair.


title: Homogenization in fractional elasticity

abstract:
  In this note we treat the equations of fractional elasticity. After
establishing well-posedness, we show a compactness result related to the theory
of homogenization. For this, a previous result in (abstract) homogenization
theory of evolutionary equations has to be improved. The approach also permits
the consideration of non-local operators (in time and space).


title:
Detecting invariant manifolds, attractors, and generalized KAM tori in
  aperiodically forced mechanical systems

abstract:
  We show how the recently developed theory of geodesic transport barriers for
fluid flows can be used to uncover key invariant manifolds in externally
forced, one-degree-of-freedom mechanical systems. Specifically, invariant sets
in such systems turn out to be shadowed by least-stretching geodesics of the
Cauchy-Green strain tensor computed from the flow map of the forced mechanical
system. This approach enables the finite-time visualization of generalized
stable and unstable manifolds, attractors and generalized KAM curves under
arbitrary forcing, when Poincare maps are not available. We illustrate these
results by detailed visualizations of the key finite-time invariant sets of
conservatively and dissipatively forced Duffing oscillators.


title:
Feature Selection for Microarray Gene Expression Data using Simulated
  Annealing guided by the Multivariate Joint Entropy

abstract:
  In this work a new way to calculate the multivariate joint entropy is
presented. This measure is the basis for a fast information-theoretic based
evaluation of gene relevance in a Microarray Gene Expression data context. Its
low complexity is based on the reuse of previous computations to calculate
current feature relevance. The mu-TAFS algorithm --named as such to
differentiate it from previous TAFS algorithms-- implements a simulated
annealing technique specially designed for feature subset selection. The
algorithm is applied to the maximization of gene subset relevance in several
public-domain microarray data sets. The experimental results show a notoriously
high classification performance and low size subsets formed by biologically
meaningful genes.


title: Strong laws for recurrence quantification analysis

abstract:
  The recurrence rate and determinism are two of the basic complexity measures
studied in the recurrence quantification analysis. In this paper, the
recurrence rate and determinism are expressed in terms of the correlation sums,
and strong laws of large numbers are given for them.


title: Hadronic Contribution to the muon $g-2$ factor

abstract:
  The lowest order hadronic contribution to the $g-2$ factor of the muon is
analyzed in the framework of the operator product expansion at short distances,
and a QCD finite energy sum rule designed to quench the role of the $e^+ e^-$
data. This procedure reduces the discrepancy between experiment and theory,
$\Delta a_\mu \equiv a^{EXP}_\mu - a^{SM}_\mu$, from $\Delta a_\mu = 28.7 (8.0)
\times 10^{-10}$ to $\Delta a_\mu = 19.2 (8.0) \times 10^{-10}$, i.e. without
changing the uncertainty.


title:
Dynamics of perturbations of the identity operator by multiples of the
  backward shift on $l^{\infty}(\mathbb{N})$

abstract:
  Let $B$, $I$ be the unweighted backward shift and the identity operator
respectively on $l^{\infty}(\mathbb{N})$, the space of bounded sequences over
the complex numbers endowed with the supremum norm. We prove that $I+\lambda B$
is locally topologically transitive if and only if $|\lambda |>2$. This, shows
that a classical result of Salas, which says that backward shift perturbations
of the identity operator are always hypercyclic, or equivalently topologically
transitive, on $l^p(\mathbb{N})$, $1\leq p<+\infty$, fails to hold for the
notion of local topological transitivity on $l^{\infty}(\mathbb{N})$. We also
obtain further results which complement certain results from \cite{CosMa}.


title: Kleene Algebra with Tests and Coq Tools for While Programs

abstract:
  We present a Coq library about Kleene algebra with tests, including a proof
of their completeness over the appropriate notion of languages, a decision
procedure for their equational theory, and tools for exploiting hypotheses of a
particular shape in such a theory. Kleene algebra with tests make it possible
to represent if-then-else statements and while loops in most imperative
programming languages. They were actually introduced by Kozen as an alternative
to propositional Hoare logic. We show how to exploit the corresponding Coq
tools in the context of program verification by proving equivalences of while
programs, correctness of some standard compiler optimisations, Hoare rules for
partial correctness, and a particularly challenging equivalence of flowchart
schemes.


title: Yet another short proof of Bourgain's distorsion estimate

abstract:
  We use a self-improvement argument to give a very short and elementary proof
of the result of Bourgain saying that regular trees do not admit bi-Lipschitz
embeddings into uniformly convex Banach spaces.


title: Electron-atom scattering in a circularly polarized laser field

abstract:
  We consider electron-atom scattering in a circularly polarized laser field at
sufficiently high electron energies, permitting to describe the scattering
process by the first order Born approximation. Assuming the radiation field has
sufficiently moderate intensities, the laser-dressing of the hydrogen target
atom in its ground state will be treated in second order perturbation theory.
Within this approximation scheme, it is shown that the nonlinear differential
cross sections of free-free transitions do neither depend on the {\it dynamical
phase} $\phi$ of the radiative process nor on the {\it helicity} of the
circularly polarized laser light. Relations to the corresponding results for
linear laser polarization are established.


title:
Crowds reaching targets by maximizing entropy: a Clausius-Duhem
  inequality approach

abstract:
  In this paper we propose the use of concepts from thermodynamics in the study
of crowd dynamics. Our continuous model consists of the continuity equation for
the density of the crowd and a kinetic equation for the velocity field. The
latter includes a nonlocal term that models interactions between individuals.
To support our modelling assumptions, we introduce an inequality that resembles
the Second Law of Thermodynamics, containing an entropy-like functional. We
show that its time derivative equals a positive dissipation term minus a
corrector term. The latter term should be small for the time derivative of the
entropy to be positive. In case of isotropic interactions the corrector term is
absent. For the anisotropic case, we support the claim that the corrector term
is small by simulations for the corresponding particle system. They reveal that
this term is sufficiently small for the entropy still to increase. Moreover, we
show that the entropy converges in time towards a limit value.


title: Discrete Distributions in the Tardos Scheme, Revisited

abstract:
  The Tardos scheme is a well-known traitor tracing scheme to protect
copyrighted content against collusion attacks. The original scheme contained
some suboptimal design choices, such as the score function and the distribution
function used for generating the biases. Skoric et al. previously showed that a
symbol-symmetric score function leads to shorter codes, while Nuida et al.
obtained the optimal distribution functions for arbitrary coalition sizes.
Later, Nuida et al. showed that combining these results leads to even shorter
codes when the coalition size is small. We extend their analysis to the case of
large coalitions and prove that these optimal distributions converge to the
arcsine distribution, thus showing that the arcsine distribution is
asymptotically optimal in the symmetric Tardos scheme. We also present a new,
practical alternative to the discrete distributions of Nuida et al. and give a
comparison of the estimated lengths of the fingerprinting codes for each of
these distributions.


title: Semigroup compactifications in terms of filters

abstract:
  We present a study of semigroup compactifications of a semitopological
semigroup $S$ using certain filters on $S$. We characterize closed
subsemigroups and closed left, right, and two-sided ideals in any semigroup
compactification of any semitopological semigroup $S$ in terms of these filters
and in terms of ideals of the corresponding $m$-admissible subalgebra of
$C(S)$. Furthermore, we characterize those points in any semigroup
compactification of $S$ which belong either to the smallest ideal of the
semigroup compactification or to the closure of this smallest ideal.


title:
Circular dichroism in free-free transitions of high energy electron-atom
  scattering

abstract:
  We consider high energy electron scattering by hydrogen atoms in the presence
of a laser field of moderate power and higher frequencies. If the field is a
superposition of a linearly and a circularly polarized laser beam in a
particular configuration, then we can show that circular dichroism in two
photon transitions can be observed not only for the differential but also for
the integrated cross sections, provided the laser-dressing of the atomic target
is treated in second order perturbation theory and the coupling between
hydrogenic bound and continuum states is involved.


title:
Few-Photon All-Optical {\pi} Phase modulation Based on a
  Double-{\Lambda} System

abstract:
  We propose an efficient all-optical phase modulation based on a
double-{\Lambda} system and demonstrate a {\pi} phase shift of a few-photon
pulse induced by another few-photon pulse in cold rubidium atoms with this
scheme. By changing the phases of the applied laser fields, one can control the
property of the double-{\Lambda} medium. This phase-dependent mechanism makes
the double-{\Lambda} system different form the conventional cross-Kerr-based
system which only depends on the applied laser intensities. The proposed scheme
provides a new route to generate strong nonlinear interactions between photons,
and may have potential for applications in quantum information technologies.


title: Further understanding of the non-$D\bar D$ decays of $\psi(3770)$

abstract:
  We provide details of the study of $\psi(3770)$ non-$D\bar D$ decays into
$VP$, where $V$ and $P$ denote light vector meson and pseudoscalar meson,
respectively. We find that the electromagnetic (EM) interaction plays little
role in these processes, while the strong interaction dominates. The strong
interaction can be separated into two parts, i.e. the short-distance part
probing the wave function at origin and the long-distance part reflecting the
soft gluon exchanged dynamics. The long-distance part is thus described by the
intermediate charmed meson loops. We show that the transition of $\psi(3770)\to
VP$ can be related to $\psi(3686)\to VP$ such that the parameters in our model
can be constrained by comparing the different parts in $\psi(3770)\to VP$ to
those in $\psi(3686)\to VP$. Our quantitative results confirm the findings of
[Zhang {\it et al.}, Phys. Rev. Lett. 102, 172001 (2009)] that the
OZI-rule-evading long-distance strong interaction via the IML plays an
important role in $\psi(3770)$ decays, and could be a key towards a full
understanding of the mysterious $\psi(3770)$ non-$D\bar{D}$ decay mechanism.


title:
Phase Effects in Two-Photon Free-Free Transitions in a Bichromatic Field
  of Frequencies $\omega$ and $3\omega$

abstract:
  The effect of the relative phase between the components of a bichromatic
field of frequencies $\omega$ and $3\omega $ is discussed in the case of
free-free transitions in laser-assisted electron-hydrogen scattering. For fast
projectile and low field intensities, the role of target dressing is pointed
out.


title:
Energy Minimization for Parallel Real-Time Systems with Malleable Jobs
  and Homogeneous Frequencies

abstract:
  In this work, we investigate the potential utility of parallelization for
meeting real-time constraints and minimizing energy. We consider malleable Gang
scheduling of implicit-deadline sporadic tasks upon multiprocessors. We first
show the non-necessity of dynamic voltage/frequency regarding optimality of our
scheduling problem. We adapt the canonical schedule for DVFS multiprocessor
platforms and propose a polynomial-time optimal processor/frequency-selection
algorithm. We evaluate the performance of our algorithm via simulations using
parameters obtained from a hardware testbed implementation. Our algorithm has
up to a 60 watt decrease in power consumption over the optimal non-parallel
approach.


title: A natural cosmological constant from chameleons

abstract:
  We present a simple model where the effective cosmological constant appears
from chameleon scalar fields. For a Kachru-Kallosh-Linde-Trivedi
(KKLT)-inspired form of the potential and a particular chameleon coupling to
the local density, patches of approximately constant scalar field potential
cluster around regions of matter with density above a certain value, generating
the effect of a cosmological constant on large scales. This construction
addresses both the cosmological constant problem (why $\Lambda$ is so small,
yet nonzero) and the coincidence problem (why $\Lambda$ is comparable to the
matter density now).


title:
Identification of intermittent multi-fractal turbulence in fully kinetic
  simulations of magnetic reconnection

abstract:
  Recent fully nonlinear, kinetic three-dimensional simulations of magnetic
reconnection [Daughton et al. 2011] evolve structures and exhibit dynamics on
multiple scales, in a manner reminiscent of turbulence. These simulations of
reconnection are among the first to be performed at sufficient spatio-temporal
resolution to allow formal quantitative analysis of statistical scaling which
we present here. We find that the magnetic field fluctuations generated by
reconnection are anisotropic, have non-trivial spatial correlation and exhibit
the hallmarks of finite range fluid turbulence; they have non-Gaussian
distributions, exhibit Extended Self-Similarity in their scaling and are
spatially multifractal. Furthermore, we find that the field J.E is also
multifractal, so that magnetic energy is converted to plasma kinetic energy in
a manner that is spatially intermittent. This suggests that dissipation in this
sense in collisionless reconnection on kinetic scales has an analogue in
fluid-like turbulent phenomenology, in that it proceeds via multifractal
structures generated by an intermittent cascade.


title: A quantum approach to the uniqueness of Reality

abstract:
  A brief review is given of the present state of an approach to consistency
between basic quantum mechanics and a unique macroscopic reality, with no
assumption of branching in the state of the universe. The main new idea
consists in the recognition of local properties in the growth and transport of
entanglement between a macroscopic measuring quantum system and a microscopic
measured one. Moving waves of entanglement from the environment arise then and
carry external phases, affecting significantly the state of the measuring
device. These "predecoherence" waves perturb randomly the growth of other
waves, which carry entanglement with the measured system. The outcome of these
wave interactions could generate random fluctuations in the quantum
probabilities of different measurement channels, which could lead in turn to a
collapse mechanism satisfying Born's probability rule, according to earlier
works by Nelson and Pearle. A necessary randomness in the environment remains
however unexplained and some suggestions regarding algorithmic complexity of
the wave functions in a large quantum system e are made along that direction.


title: Bass units as free factors in integral group rings of simple groups

abstract:
  Let $G$ be a finite group, $u$ a Bass unit based on an element $a$ of $G$ of
prime order, and assume that $u$ has infinite order modulo the center of the
units of the integral group ring $\Z G$. It was recently proved that if $G$ is
solvable then there is a Bass unit or a bicyclic unit $v$ and a positive
integer $n$ such that the group generated by $u^n$ and $v^n$ is a non-abelian
free group. It has been conjectured that this holds for arbitrary groups $G$.
To prove this conjecture it is enough to do it under the assumption that $G$ is
simple and $a$ is a dihedral $p$-critical element in $G$. We first classify the
simple groups with a dihedral $p$-critical element. They are all of the form
$\PSL(2,q)$. We prove the conjecture for $p=5$; for $p>5$ and $q$ even; and for
$p>5$ and $q+1=2p$. We also provide a sufficient condition for the conjecture
to hold for $p>5$ and $q$ odd. With the help of computers we have verified the
sufficient condition for all $q<10000$.