title: Adaptation to the Primary User CSI in Cognitive Radio Sensing and Access

abstract:
  In Cognitive Radio (CR) networks, multiple secondary network users (SUs)
attempt to communicate over wide potential spectrum without causing significant
interference to the Primary Users (PUs). A spectrum sensing algorithm is a
critical component of any sensing strategy. Performance of conventional
spectrum detection methods is severely limited when the average SNR of the
fading channel between the PU transmitter and the SU sensor is low. Cooperative
sensing and advanced detection techniques only partially remedy this problem. A
key limitation of conventional approaches is that the sensing threshold is
determined from the miss detection rate averaged over the fading distribution.
In this paper, the threshold is adapted to the instantaneous PU-to-SU Channel
State Information (CSI) under the prescribed collision probability constraint,
and a novel sensing strategy design is proposed for overlay CR network where
the instantaneous false alarm probability is incorporated into the belief
update and the reward computation. It is demonstrated that the proposed sensing
approach improves SU confidence, randomizes sensing decisions, and
significantly improves SU network throughput while satisfying the collision
probability constraint to the PUs in the low average PU-to-SU SNR region.
Moreover, the proposed adaptive sensing strategy is robust to mismatched and
correlated fading CSI and improves significantly on conventional cooperative
sensing techniques. Finally, joint adaptation to PU channel gain and SU link
CSI is explored to further improve CR throughput and reduce SU collisions.


title: More stable dS vacua from S-dual non-geometric fluxes

abstract:
  Stable vacua obtained from isotropic tori compactification might not be fully
stable provided the existence of runaway directions in the Kaehler directions
of anisotropy. By implementing a genetic algorithm we report the existence of
explicit flux configurations leading to stable de Sitter and Anti- de Sitter
vacua, consisting on Type IIB compactifications on a 6-dimensional anisotropic
torus threaded with standard and S-dual invariant non-geometric fluxes in the
presence of orientifold 3-planes. In all dS vacua the masses of the complex
structure moduli are heavier than the Hubble scale suggesting that the
axio-dilaton and Kaeahler moduli are natural candidates for small-field
inflation. In the way, we also report new solutions on isotropic and
semi-isotropic tori compactifications. Finally, we observe that, since all our
solutions are obtained in the absence of solitonic objects, they are good
candidates to be lifted to stable solutions in extended supersymmetric
theories.


title: A local fingerprinting approach for audio copy detection

abstract:
  This study proposes an audio copy detection system that is robust to various
attacks. These include the severe pitch shift and tempo change attacks which
existing systems fail to detect. First, we propose a novel two dimensional
representation for audio signals called the time-chroma image. This image is
based on a modification of the concept of chroma in the music literature and is
shown to achieve better performance in song identification. Then, we propose a
novel fingerprinting algorithm that extracts local fingerprints from the
time-chroma image. The proposed local fingerprinting algorithm is invariant to
time/frequency scale changes in audio signals. It also outperforms existing
methods like SIFT by a great extent. Finally, we introduce a song
identification algorithm that uses the proposed fingerprints. The resulting
copy detection system is shown to significantly outperform existing methods.
Besides being able to detect whether a song (or a part of it) has been copied,
the proposed system can accurately estimate the amount of pitch shift and/or
tempo change that might have been applied to a song.


title: Sub-parsec radio cores in nearby Seyfert galaxies

abstract:
  We present a census of sub-pc scale properties of the VLBI cores in a
complete sample of local Seyfert galaxies. Seventeen out of 23 sources with a
VLA detection are detected also with VLBI at 1.7 GHz and/or 5 GHz, with an
average monochromatic radio luminosity log [P (5\, GHz) W Hz^{-1} = 19.4. Radio
cores are of heterogeneous nature, the majority of them showing elongated
structures or accompanied by extra components, broad ranges of brightness
temperatures (10^{5}-10^{10} K) and spectral indices (from steep to highly
inverted). Interestingly, the detection rate (26%) of water maser emission is
considerably higher than that found in previous surveys (around 10%),
suggesting that distance biases could significantly affect our knowledge of the
actual occurrence of this phenomenon. The VLBI observational properties of type
1 and type 2 nuclei are similar except for the T_{B}, which is on average
higher in type 1. These results suggest that both thermal and non-thermal
emission are common in low luminosity AGN, with a prevalence of free-free
processes among type 2 cores, likely associated to molecular gas. Though
limited by the low number statistics, we find no significant correlation
between the VLBI radio luminosity and the nuclear X-ray luminosity, the latter
appears to be more connected to the tens of pc scales VLA radio emission,
rather than to the sub-pc scales, particularly in the most X-ray luminous
sources. The X-ray radio-loudness parameter R_{X} = L (6cm)/L(2-10 keV), is on
average very low (< log R_X > = -4.8), with comparatively higher R_{X} found
for sources with the largest black hole masses and the lowest Eddington ratios,
although the radio power does not appear to depend on the accretion rate.


title:
Outflow vs. Infall in Spiral Galaxies: Metal Absorption in the Halo of
  NGC 891

abstract:
  Gas accreting onto a galaxy will be of low metallicity while halo gas due to
a galactic fountain will be of near-solar metallicity. We test these
predictions by measuring the metal absorption line properties of halo gas 5 kpc
above the plane of the edge-on galaxy NGC 891, using observations taken with
HST/STIS toward a bright background quasar. Metal absorption lines of Fe II, Mg
II, and Mg I in the halo of NGC 891 are clearly seen, and when combined with
recent deep H I observations, we are able to place constraints on the
metallicity of the halo gas for the first time. The H I line width defines the
line broadening, from which we model opacity effects in these metal lines,
assuming the absorbing gas is continuously distributed in the halo. The
gas-phase metallicities are [Fe/H] = -1.18 +/- 0.07 and [Mg/H] = -0.23
+0.36/-0.27 (statistical errors) and this difference is probably due to
differential depletion onto grains. When corrected for such depletion using
Galactic gas as a guide, both elements have approximately solar or even
supersolar abundances. This suggests that the gas is from the galaxy disk,
probably expelled into the halo by a galactic fountain, rather than from
accretion of intergalactic gas, which would have a low metallicity. The
abundances would be raised by significant amounts if the absorbing gas lies in
a few clouds with thermal widths smaller than the rotational velocity of the
halo. If this is the case, both the abundances and [Mg/Fe] would be supersolar.


title: Direction-Projection-Permutation for High Dimensional Hypothesis Tests

abstract:
  Motivated by the prevalence of high dimensional low sample size datasets in
modern statistical applications, we propose a general nonparametric framework,
Direction-Projection-Permutation (DiProPerm), for testing high dimensional
hypotheses. The method is aimed at rigorous testing of whether lower
dimensional visual differences are statistically significant. Theoretical
analysis under the non-classical asymptotic regime of dimension going to
infinity for fixed sample size reveals that certain natural variations of
DiProPerm can have very different behaviors. An empirical power study both
confirms the theoretical results and suggests DiProPerm is a powerful test in
many settings. Finally DiProPerm is applied to a high dimensional gene
expression dataset.


title:
On the speed of convergence in the local limit theorem for triangular
  arrays of random variables

abstract:
  We establish the upper bound on the speed of convergence to the infinitely
divisible limit density in the local limit theorem for triangular arrays of
random variables $\{X_{k,n},\, k=1,..,a_n, \, n\in \nat\}$.


title: Fermi-LAT Observation of Impulsive Solar Flares

abstract:
  The Fermi Large Area Telescope (LAT) is the most sensitive instrument ever
deployed in space for observing gamma-ray emission >100 MeV. This sensitivity
has enabled the LAT to detect gamma-ray emission from the Sun during quiescent
periods from pions produced by cosmic-ray protons interacting in the solar
atmosphere and from cosmic-ray electrons interacting with solar optical
photons. The LAT has detected high-energy gamma-ray emission associated with
GOES M-class and X-class X-ray flares accompanied by coronal mass ejections and
solar energetic particle events. In a number of cases, LAT has detected gamma
rays with energies up to several hundreds of MeV during the impulsive phase and
gamma rays up to GeV energies sustained for several hours after the impulsive
phase. This presentation focuses on observations in the impulsive emission
phase in solar flares, including the modest GOES M2-class flare at
SOL2010-06-12T0057 and more recent detections, such as the bright X-class
flares of March 2012.


title:
Fine structure collision strengths and line ratios for [Ne V] in
  infrared and optical sources

abstract:
  Improved collisions strengths for the mid-infrared and optical transitions in
Ne V are presented. Breit-Pauli R-Matrix calculations for electron impact
excitation are carried out with fully resolved near-threshold resonances at
very low energies. In particular, the fine structure lines at 14 micron and 24
micron due to transitions among the ground state levels 1s^22s^22p^3
(^3P_{0,1,2}), and the optical/near-UV lines at 2973, 3346 and 3426 Angstrom
transitions among the ^3P_{0,1,2}, ^1D_2, ^1S_0 levels are described.
Maxwellian averaged collision strengths are tabulated for all forbidden
transistion within the ground configuration. Significant differences are found
in the low temperature range Te < 10000 K for both the FIR and the opitcal
transitions compared to previous results. An analysis of the 14/24 line ratio
in low-energy-density (LED) plasma conditions reveals considerable variation;
the effective rate coefficient may be dominated by the very low-energy
behaviour rather than the maxwellian averaged collision strengths. Computed
values suggest a possible solution to the anomalous mid-IR ratios found to be
lower than theoretical limits observed from planetary nebulae and Seyfert
galaxies. While such LED conditions may be present in infrared sources, they
might be inconsistent with photoionization equilibrium models.


title: The asymmetric simple exclusion process with an open boundary

abstract:
  We consider the asymmetric simple exclusion process confined to the
nonnegative integers with an open boundary at 0. The point 0 is connected to a
reservoir where particles are injected and ejected at prescribed rates subject
to the exclusion rule. We derive formulas for the transition probability as a
function of time from states where initially there are m particles to states
where there are n particles.


title:
Total nonnegativity of infinite Hurwitz matrices of entire and
  meromorphic functions

abstract:
  In this paper we fully describe functions generating the infinite totally
nonnegative Hurwitz matrices. In particular, we generalize the well-known
result by Asner and Kemperman on the total nonnegativity of the Hurwitz
matrices of real stable polynomials. An alternative criterion for entire
functions to generate a P\'olya frequency sequence is also obtained. The
results are based on a connection between a factorization of totally
nonnegative matrices of the Hurwitz type and the expansion of Stieltjes
meromorphic functions into Stieltjes continued fractions (regular $C$-fractions
with positive coefficients).


title:
Regenerative tree growth: Markovian embedding of fragmenters,
  bifurcators, and bead splitting processes

abstract:
  Some, but not all processes of the form $M_t=\exp(-\xi_t)$ for a pure-jump
subordinator $\xi$ with Laplace exponent $\Phi$ arise as residual mass
processes of particle 1 (tagged particle) in Bertoin's partition-valued
exchangeable fragmentation processes. We introduce the notion of a Markovian
embedding of $M=(M_t,t\ge 0)$ in a fragmentation process, and we show that for
each $\Phi$, there is a unique (in distribution) binary fragmentation process
in which $M$ has a Markovian embedding. The identification of the Laplace
exponent $\Phi^*$ of its tagged particle process $M^*$ gives rise to a
symmetrisation operation $\Phi\mapsto\Phi^*$, which we investigate in a general
study of pairs $(M,M^*)$ that coincide up to a random time and then evolve
independently. We call $M$ a fragmenter and $(M,M^*)$ a bifurcator. For
$\alpha>0$, we equip the interval $R_1=[0,\int_0^{\infty}M_t^{\alpha}\,dt]$
with a purely atomic probability measure $\mu_1$, which captures the jump sizes
of $M$ suitably placed on $R_1$. We study binary tree growth processes that in
the $n$th step sample an atom (``bead'') from $\mu _n$ and build
$(R_{n+1},\mu_{n+1})$ by replacing the atom by a rescaled independent copy of
$(R_1,\mu_1)$ that we tie to the position of the atom. We show that any such
bead splitting process $((R_n,\mu_n),n\ge1)$ converges almost surely to an
$\alpha$-self-similar continuum random tree of Haas and Miermont, in the
Gromov-Hausdorff-Prohorov sense. This generalises Aldous's line-breaking
construction of the Brownian continuum random tree.


title:
Interferometric Visibility of a Scintillating Source: Statistics at the
  Nyquist Limit

abstract:
  We derive the distribution of interferometric visibility for a source
exhibiting strong diffractive scintillation, with particular attention to
spectral resolution at or near the Nyquist limit. We also account for arbitrary
temporal averaging, intrinsic variability within the averaging time, and the
possibility of spatially-extended source emission. We demonstrate that the
interplay between scintillation and self-noise induces several remarkable
features, such as a broad "skirt" in the visibility distribution. Our results
facilitate the interpretation of interferometric observations of pulsars at
meter and decimeter wavelengths.


title:
Numerical simulations of particle sedimentation using the immersed
  boundary method

abstract:
  We study the settling of solid particles within a viscous incompressible
fluid contained in a two-dimensional channel, where the mass density of the
particles is slightly greater than that of the fluid. The fluid-structure
interaction problem is simulated numerically using the immersed boundary
method, with an added mass term that is incorporated using a Boussinesq
approximation. Simulations are performed with a single circular particle, and
also with two particles in various initial configurations. The terminal
settling velocities for the particles correspond closely with both theoretical
and experimental results, and the single-particle dynamics reproduce expected
behavior qualitatively. The two-particle simulations exhibit
drafting-kissing-tumbling dynamics that is similar to what is observed in other
experimental and numerical studies.


title:
Hitting times of rare events in boundary driven symmetric simple
  exclusion processes

abstract:
  In the boundary driven symmetric simple exclusion process consider an open
set $\ms O$ of density profiles which does not contain the stationary density
profile. We prove that the first time the empirical measure visits the set $\ms
O$ converges to an exponential distribution.


title: IFP-Intuitionistic fuzzy soft set theory and its applications

abstract:
  In this work, we present definition of intuitionistic fuzzy parameterized
(IFP) intuitionistic fuzzy soft set and its operations. Then we define
IFP-aggregation operator to form IFP-intuitionistic fuzzy soft-decision-making
method which allows constructing more efficient decision processes.


title:
Network Access Control Technology - Proposition to contain new security
  challenges

abstract:
  Traditional products working independently are no longer sufficient, since
threats are continually gaining in complexity, diversity and performance; In
order to proactively block such threats we need more integrated information
security solution. To achieve this objective, we will analyze a real-world
security platform, and focus on some key components Like, NAC, Firewall, and
IPS/IDS then study their interaction in the perspective to propose a new
security posture that coordinate and share security information between
different network security components, using a central policy server that will
be the NAC server or the PDP (the Policy Decision Point), playing an
orchestration role as a central point of control. Finally we will conclude with
potential research paths that will impact NAC technology evolution.


title: Essential Circles and Gromov-Hausdorff Convergence of Covers

abstract:
  We give various applications of essential circles (introduced in an earlier
paper by the authors) in a compact geodesic space X. Essential circles
completely determine the homotopy critical spectrum of X, which we show is
precisely 2/3 the covering spectrum of Sormani-Wei. We use finite collections
of essential circles to define "circle covers," which extend and contain as
special cases the delta-covers of Sormani and Wei (equivalently the
epsilon-covers of the authors); the constructions are metric adaptations of
those utilized by Berestovskii-Plaut in the construction of entourage covers of
uniform spaces. We show that, unlike delta- and epsilon-covers, circle covers
are in a sense closed with respect to Gromov-Hausdorff convergence, and we
prove a finiteness theorem concerning their deck groups that does not hold for
covering maps in general. This allows us to completely understand the structure
of Gromov-Hausdorff limits of delta-covers. Also, we use essential circles to
strengthen a theorem of E. Cartan by finding a new (even for compact Riemannian
manifolds) finite set of generators of the fundamental group of a semilocally
simply connected compact geodesic space. We conjecture that there is always a
generating set of this sort having minimal cardinality among all generating
sets.


title:
New Equations for Neutral Terms: A Sound and Complete Decision
  Procedure, Formalized

abstract:
  The definitional equality of an intensional type theory is its test of type
compatibility. Today's systems rely on ordinary evaluation semantics to compare
expressions in types, frustrating users with type errors arising when
evaluation fails to identify two `obviously' equal terms. If only the machine
could decide a richer theory! We propose a way to decide theories which
supplement evaluation with `$\nu$-rules', rearranging the neutral parts of
normal forms, and report a successful initial experiment.
  We study a simple -calculus with primitive fold, map and append operations on
lists and develop in Agda a sound and complete decision procedure for an
equational theory enriched with monoid, functor and fusion laws.


title: Bose-Einstein Condensation in Satisfiability Problems

abstract:
  This paper is concerned with the complex behavior arising in satisfiability
problems. We present a new statistical physics-based characterization of the
satisfiability problem. Specifically, we design an algorithm that is able to
produce graphs starting from a k-SAT instance, in order to analyze them and
show whether a Bose-Einstein condensation occurs. We observe that, analogously
to complex networks, the networks of k-SAT instances follow Bose statistics and
can undergo Bose-Einstein condensation. In particular, k-SAT instances move
from a fit-get-rich network to a winner-takes-all network as the ratio of
clauses to variables decreases, and the phase transition of k-SAT approximates
the critical temperature for the Bose-Einstein condensation. Finally, we employ
the fitness-based classification to enhance SAT solvers (e.g., ChainSAT) and
obtain the consistently highest performing SAT solver for CNF formulas, and
therefore a new class of efficient hardware and software verification tools.


title: Fluorine-induced local magnetic moment in graphene: A hybrid DFT study

abstract:
  Recent experimental evidence that fluorinated graphene creates local magnetic
moments around F adatoms has not been supported by semilocal density-functional
theory (DFT) calculations where the adsorption of an isolated F adatom induces
no magnetic moment in graphene. Here, we show that such an incorrect prediction
of the nonmagnetic ground state is due to the self-interaction error inherent
in semilocal exchange-correlation functionals. The present hybrid DFT
calculation for an isolated F adatom on graphene predicts not only a
spin-polarized ground state with a spin moment of 1 bohr magneton, but also a
long-range spin polarization caused by the bipartite nature of the graphene
lattice as well as the induced spin polarization of the graphene states. The
results provide support for the experimental observations of local magnetic
moments in fluorinated graphene.


title: Observations of Crab Giant Pulses in 20-84 MHz using LWA1

abstract:
  We report the detection and observed characteristics of giant pulses from the
Crab Nebula pulsar (B0531+21) in four frequency bands covering 20-84 MHz using
the recently-completed Long Wavelength Array Station 1 (LWA1) radio telescope.
In 10 hours of observations distributed over a 72-day period in Fall of 2012,
33 giant pulses having peak flux densities between 400 Jy and 2000 Jy were
detected. Twenty-two of these pulses were detected simultaneously in channels
of 16 MHz bandwidth centered at 44 MHz, 60 MHz, and 76 MHz, including one pulse
which was also detected in a channel centered at 28 MHz. We quantify statistics
of pulse amplitude and pulse shape characteristics, including pulse broadening.
Amplitude statistics are consistent with expectations based on extrapolations
from previous work at higher and lower frequencies. Pulse broadening is found
to be relatively high, but not significantly greater than expected. We present
procedures that have been found to be effective for observing giant pulses in
this frequency range.


title: AF Systems of Certain Cyclic Groups

abstract:
  A K-theoretic classification is given for AF systems of cyclic groups with
prime orders.


title:
Continuous- and discrete-time Glauber dynamics. First- and second-order
  phase transitions in mean-field Potts models

abstract:
  As is known, at the Gibbs-Boltzmann equilibrium, the mean-field $q$-state
Potts model with a ferromagnetic coupling has only a first order phase
transition when $q\geq 3$, while there is no phase transition for an
antiferromagnetic coupling. The same equilibrium is asymptotically reached when
one considers the continuous time evolution according to a Glauber dynamics. In
this paper we show that, when we consider instead the Potts model evolving
according to a discrete-time dynamics, the Gibbs-Boltzmann equilibrium is
reached only when the coupling is ferromagnetic while, when the coupling is
anti-ferromagnetic, a period-2 orbit equilibrium is reached and a stable
second-order phase transition in the Ising mean-field universality class sets
in for each component of the orbit. We discuss the implications of this
scenario in real-world problems.


title:
Population II stars and the Spite plateau; Stellar evolution models with
  mass loss

abstract:
  We aim to determine the constraints that observed chemical abundances put on
the potential role of mass loss in metal poor dwarfs. Self-consistent stellar
evolutionary models that include all the effects of atomic diffusion and
radiative accelerations for 28 chemical species were computed for stellar
masses between 0.6 and 0.8 Msun. Models with an initial metallicity of
Z_0=0.00017 and mass loss rates from 10e-15 Msun to 10e-12 Msun were
calculated. They were then compared to previous models with mass loss, as well
as to models with turbulent mixing. For models with an initial metallicity of
Fe/H=-2.31, mass loss rates of about 10e-12 Msun lead to surface abundance
profiles that are very similar to those obtained in models with turbulence.
Both models have about the same level of agreement with observations of
galactic-halo lithium abundances, as well as lithium and other elemental
abundances from metal poor globular clusters such as NGC 6397. In this cluster,
models with mass loss agree slightly better with subgiant observations of Li
abundance than those with turbulence. Lower red giant branch stars instead
favor the models with turbulence. Larger differences between models with mass
loss and those with turbulence appear in the interior concentrations of metals.
The relatively high mass loss rates required to reproduce plateau-like lithium
abundances appear unlikely when compared to the solar mass-loss rate. However
the presence of a chromosphere on these stars justifies further investigation
of the mass-loss rates.


title:
Asymptotic self-similarity and order-two ergodic theorems for renewal
  flows

abstract:
  We prove a log average almost-sure invariance principle (log asip) for
renewal processes with positive i.i.d. gaps in the domain of attraction of an
$\alpha$-stable law with $0<\alpha<1$. Dynamically, this means that renewal and
Mittag-Leffler paths are forward asymptotic in the scaling flow, up to a time
average. This strengthens the almost-sure invariance principle in log density
we proved in {FisherTalet2011}. The scaling flow is a Bernoulli flow on a
probability space. We study a second flow, the increment flow, transverse to
the scaling flow, which preserves an infinite invariant measure constructed
using singular cocycles. A cocycle version of the Hopf Ratio Ergodic Theorem
leads to an order--two ergodic theorem for the Mittag--Leffler increment flow.
Via the log asip, this result then passes to a second increment flow,
associated to the renewal process. As corollaries, we have new proofs of
theorems of {AaronsonDenkerFisher1992} and of {ChungErdos1951}, motivated by
fractal geometry.


title:
Improving transcriptome assembly through error correction of
  high-throughput sequence reads

abstract:
  The study of functional genomics--particularly in non-model organisms has
been dramatically improved over the last few years by use of transcriptomes and
RNAseq. While these studies are potentially extremely powerful, a
computationally intensive procedure--the de novo construction of a reference
transcriptome must be completed as a prerequisite to further analyses. The
accurate reference is critically important as all downstream steps, including
estimating transcript abundance are critically dependent on the construction of
an accurate reference. Though a substantial amount of research has been done on
assembly, only recently have the pre-assembly procedures been studied in
detail. Specifically, several stand-alone error correction modules have been
reported on, and while they have shown to be effective in reducing errors at
the level of sequencing reads, how error correction impacts assembly accuracy
is largely unknown. Here, we show via use of a simulated dataset, that applying
error correction to sequencing reads has significant positive effects on
assembly accuracy, by reducing assembly error by nearly 50%, and therefore
should be applied to all datasets.


title: Stochastic Generalized Porous Media Equations with Reflection

abstract:
  A non-negative Markovian solution is constructed for a class of stochastic
generalized porous media equations with reflection. To this end, some
regularity properties and a comparison theorem are proved for stochastic
generalized porous media equations, which are interesting by themselves.
Invariant probability measures and ergodicity of the solution are also
investigated.


title: Twenty open problems in quantum control

abstract:
  The subject of controlling quantum systems is not new, but concepts that have
been introduced in the last decade and a half, especially that of coherent
feedback, suggest new questions that broaden and deepen the field. Here we
provide a concise overview and definition of quantum feedback control, both
coherent and measurement-based, and discuss its relationship to "standard"
time-dependent control; there is a sense in which the latter subsumes the rest.
There are many open questions within quantum control and its subfields, and we
highlight and discuss some of them here. These questions are of theoretical as
well as practical interest: the answers will help to determine the relative
power of the different methods of control, and the limits to our ability to
control quantum systems imposed by available resources.


title:
Effects of ground-state correlations on collective excitations of
  $^{16}$O

abstract:
  The effects of the correlations in the ground state of $^{16}$O on the
octupole and dipole excitations are studied using the extended random phase
approximation (ERPA) derived from the time-dependent density-matrix theory. It
is found that the ground-state correlation effects are significant especially
in the octupole excitation. It is shown that the first $3^-$ state calculated
in the random phase approximation (RPA) is shifted upward when the self-energy
contributions are included in particle - hole pairs. The coupling to the two
particle - two hole states plays a role in shifting the first $3^-$ state down
to the right position. It is also found that the dipole strength is fragmented
due to the partial occupation of the single-particle states and that the peak
position of the giant dipole resonance calculated in ERPA is little changed
from that in RPA due to the above-mentioned competing effects: the increase in
particle - hole energy and the coupling to two particle - two hole
configurations.


title: Testing of Cryogenic Photomultiplier Tubes for the MicroBooNE Experiment

abstract:
  The MicroBooNE detector, to be located on axis in the Booster Neutrino
Beamline (BNB) at the Fermi National Accelerator Laboratory (Fermilab),
consists of two main components: a large liquid argon time projection chamber
(LArTPC), and a light collection system. Thirty 8-inch diameter Hamamatsu
R5912-02mod cryogenic photomultiplier tubes (PMTs) will detect the
scintillation light generated in the liquid argon (LAr). This article first
describes the MicroBooNE PMT performance test procedures, including how the
light collection system functions in the detector, and the design of the PMT
base. The design of the cryogenic test stand is then discussed, and finally the
results of the cryogenic tests are reported.


title:
Detailing N=1 Seiberg's Duality through the Seiberg-Witten Solution of
  N=2

abstract:
  Starting from the Seiberg-Witten solution of N=2 SQCD with the U(N) gauge
group and N_f quark flavors we construct the so-called \mu-dual N=1 theory in
the r vacua in the regime analogous to that existing to the left of the left
edge of the Seiberg conformal window (here r is the number of condensed
quarks). The strong-weak coupling duality is shown to exist in the so-called
zero vacua which can be found at r< N_f-N. We show that the \mu-dual theory
matches the Seiberg dual in the zero vacua.


title: Lie Algebrized Gaussians for Image Representation

abstract:
  We present an image representation method which is derived from analyzing
Gaussian probability density function (\emph{pdf}) space using Lie group
theory. In our proposed method, images are modeled by Gaussian mixture models
(GMMs) which are adapted from a globally trained GMM called universal
background model (UBM). Then we vectorize the GMMs based on two facts: (1)
components of image-specific GMMs are closely grouped together around their
corresponding component of the UBM due to the characteristic of the UBM
adaption procedure; (2) Gaussian \emph{pdf}s form a Lie group, which is a
differentiable manifold rather than a vector space. We map each Gaussian
component to the tangent vector space (named Lie algebra) of Lie group at the
manifold position of UBM. The final feature vector, named Lie algebrized
Gaussians (LAG) is then constructed by combining the Lie algebrized Gaussian
components with mixture weights. We apply LAG features to scene category
recognition problem and observe state-of-the-art performance on 15Scenes
benchmark.


title:
The ACS Virgo Cluster Survey. XVII. The Spatial Alignment of Globular
  Cluster Systems With Early-Type Host Galaxies

abstract:
  We study the azimuthal distribution of globular clusters (GCs) in early-type
galaxies and compare them to their host galaxies using data from the ACS Virgo
Cluster Survey. We find that in host galaxies with visible elongation (epsilon
> 0.2) and intermediate to high luminosities (M_z<-19), the GCs are
preferentially aligned along the major axis of the stellar light. The red
(metal-rich) GC subpopulations show strong alignment with the major axis of the
host galaxy, which supports the notion that these GCs are associated with
metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of
being more strongly associated with disks rather than bulges. Surprisingly, we
find that the blue (metal-poor) GCs can also show the same correlation. If the
metal-poor GCs are part of the early formation of the halo and built up through
mergers, then our results support a picture where halo formation and merging
occur anisotropically, and where the present day major axis is an indicator of
the preferred merging axis.


title:
Synthesizing Switching Controllers for Hybrid Systems by Continuous
  Invariant Generation

abstract:
  We extend a template-based approach for synthesizing switching controllers
for semi-algebraic hybrid systems, in which all expressions are polynomials.
This is achieved by combining a QE (quantifier elimination)-based method for
generating continuous invariants with a qualitative approach for predefining
templates. Our synthesis method is relatively complete with regard to a given
family of predefined templates. Using qualitative analysis, we discuss
heuristics to reduce the numbers of parameters appearing in the templates. To
avoid too much human interaction in choosing templates as well as the high
computational complexity caused by QE, we further investigate applications of
the SOS (sum-of-squares) relaxation approach and the template polyhedra
approach in continuous invariant generation, which are both well supported by
efficient numerical solvers.


title:
Infrared Vortex-State Electrodynamics in Type-II Superconducting Thin
  Films

abstract:
  The vortex-state electrodynamics of s-wave superconductors has been studied
by infrared spectroscopy. Far-infrared transmission and reflection spectra of
superconducting NbTiN and NbN thin films were measured in a magnetic field
perpendicular to the film surface, and the optical conductivity was extracted.
The data show clear reduction of superconducting signature. We consider the
vortex state as a two-component effective medium of normal cores embedded in a
BCS superconductor. The spectral features are well explained by the
Maxwell-Garnett theory. Our analysis supports the presence of
magnetic-field-induced pair-breaking effects in the superconducting component
outside of the vortex cores.


title: Monotonicity Results for Dirichlet L-functions

abstract:
  We present some monotonicity results for Dirichlet $L$-functions associated
to real primitive characters. We show in particular that these Dirichlet
$L$-functions are far from being logarithmically completely monotonic. Also, we
show that, unlike in the case of the Riemann zeta function, the problem of
comparing the signs of $\frac{d^k}{ds^k}\log L(s,\chi)$ at any two points $s_1,
s_2>1$ is more subtle.


title: Computational Lower Bounds for Sparse PCA

abstract:
  In the context of sparse principal component detection, we bring evidence
towards the existence of a statistical price to pay for computational
efficiency. We measure the performance of a test by the smallest signal
strength that it can detect and we propose a computationally efficient method
based on semidefinite programming. We also prove that the statistical
performance of this test cannot be strictly improved by any computationally
efficient method. Our results can be viewed as complexity theoretic lower
bounds conditionally on the assumptions that some instances of the planted
clique problem cannot be solved in randomized polynomial time.


title: Regular graphs and the spectra of two-variable logic with counting

abstract:
  The {\em spectrum} of a first-order logic sentence is the set of natural
numbers that are cardinalities of its finite models. In this paper we show that
when restricted to using only two variables, but allowing counting quantifiers,
the spectra of first-order logic sentences are semilinear and hence, closed
under complement. At the heart of our proof are semilinear characterisations
for the existence of regular and biregular graphs, the class of graphs in which
there are a priori bounds on the degrees of the vertices.
  Our proof also provides a simple characterisation of models of two-variable
logic with counting -- that is, up to renaming and extending the relation
names, they are simply a collection of regular and biregular graphs.


title: Spin Hall effect in a simple classical picture of spin forces

abstract:
  Spin Hall effect (SHE) in a 2D-Rashba system has been treated in the
spin-dependent precession [J. Sinova et al., Phys. Rev. Letts. 92, 126603
(2004).] and the time-space gauge [T. Fujita et al., New J. Phys. 12, 013016
(2010).] approaches, both yielding SHE conductivity of {\sigma}_y^z=e/8{\pi} .
Separate studies based on the concept of spin transverse force [S-Q Shen, Phys.
Rev. Lett. 95, 187203 (2005).] provide a heuristic but not a quantifiable
indication of SHE. In this paper, we provide a more complete description of the
SHE using the Heisenberg approach, unifying the Yang-Mills force, the
Heisenberg spin force, and the SHE {\sigma}_y^z under the classical notion of
forces and accelerations. Central to this paper is the spin force equations
that are satisfied by both {\sigma}_y^z and {\sigma}_x^z, the Yang-Mills, and
the Heisenberg spin forces. By linking {\sigma}_y^z to the spin forces, one
sees that the physics of SHE in a 2D-Rashba system is also a simple classical
Lorentz force picture.


title:
Viability of detection by AMS of sudden features due to dark matter
  annihilation to positrons and electrons

abstract:
  The Fermi experiment has measured the cosmic ray electron+positron spectrum
and positron fraction [$\Phi_{e^+}/(\Phi_{e^+ + e^-})]$, and PAMELA has
measured the positron fraction with better precision. While the majority of
cosmic ray electrons and positrons are of astrophysical origin, there may also
be a contribution from dark matter annihilation in the galactic halo. The
upcoming results of the AMS experiment will show measurements of these
quantities with far greater precision. One dark matter annihilation scenario is
where two dark matter particles annihilate directly to $e^+$ and $e^-$ final
states. In this article, we calculate the signature "bumps" in these
measurements assuming a given density profile (NFW profile). If the dark matter
annihilates to electrons and positrons with a cross section $\sigma v \sim\,
10^{-26}$ cm$^3$/s or greater, this feature may be discernible by AMS. However,
we demonstrate that such a prominent spectral feature is already ruled out by
the relative smoothness of the positron + electron cosmic ray spectrum as
measured by Fermi. Hence we conclude that such a feature is undetectable unless
the mass is less than $\sim$40 GeV.


title:
Convergence to pulsating traveling waves with minimal speed in some KPP
  heterogeneous problems

abstract:
  The notion of traveling wave, which typically refers to some particular
spatio-temporal con- nections between two stationary states (typically, entire
solutions keeping the same profile's shape through time), is essential in the
mathematical analysis of propagation phenomena. They provide insight on the
underlying dynamics, and an accurate description of large time behavior of
large classes of solutions, as we will see in this paper. For instance, in an
homogeneous framework, it is well-known that, given a fast decaying initial
datum (for instance, compactly supported), the solution of a KPP type
reaction-diffusion equation converges in both speed and shape to the traveling
wave with minimal speed. The issue at stake in this paper is the gener-
alization of this result to some one-dimensional heterogeneous environments,
namely spatially periodic or converging to a spatially periodic medium. This
result fairly improves our under- standing of the large-time behavior of
solutions, as well as of the role of heterogeneity, which has become a crucial
challenge in this field over the past few years.


title:
A new way to explain the 511 keV signal from the center of the Galaxy
  and its possible consequences

abstract:
  The first gamma-ray line originating from outside the solar system that was
ever detected is the 511 keV emission from the center of our Galaxy. The
accepted explanation of this signal is the annihilation of electrons and
positrons. However, despite 30 years of intense theoretical and observational
investigation, the main sources of positrons have not been identified up to
now. In this paper I propose an alternative explanation: the observed signal is
due to atomic transitions to "small hydrogen atom," where electron is captured
by proton on a small tight orbit around proton. I describe the status of the
experimental search to find the small hydrogen atom both in astrophysics data
and the lab, and propose new methods how to discover it in the lab directly.
The reason we are interested in this problem is that it could explain some
astrophysics observations.
  Key words: 511 keV peak at the galactic center, small hydrogen atom, DDL
atom, dark matter


title:
Long-time asymptotics for the porous medium equation: The spectrum of
  the linearized operator

abstract:
  We compute the complete spectrum of the displacement Hessian operator, which
is obtained from the confined porous medium equation by linearization around
its stationary attractor, the Barenblatt profile. On a formal level, the
operator is conjugate to the Hessian of the entropy via similarity
transformation. We show that the displacement Hessian can be understood as a
self-adjoint operator and find that its spectrum is purely discrete. The
knowledge of the complete spectrum and the explicit information about the
corresponding eigenfunctions give new insights on the convergence and higher
order asymptotics of solutions to the porous medium equation towards its
attractor. More precisely, the inspection of the eigenfunctions allows to
identify symmetries in $\mathbbm{R}^N$ with flows whose rates of convergence
are faster than the uniform, translation-governed bound. The present work
complements the analogous study of Denzler & McCann for the fast-diffusion
equation.


title: Improved Analytical Delay Models for RC-Coupled Interconnects

abstract:
  As the process technologies scale into deep submicron region, crosstalk delay
is becoming increasingly severe, especially for global on-chip buses. To cope
with this problem, accurate delay models of coupled interconnects are needed.
In particular, delay models based on analytical approaches are desirable,
because they not only are largely transparent to technology, but also
explicitly establish the connections between delays of coupled interconnects
and transition patterns, thereby enabling crosstalk alleviating techniques such
as crosstalk avoidance codes (CACs). Unfortunately, existing analytical delay
models, such as the widely cited model in [1], have limited accuracy and do not
account for loading capacitance. In this paper, we propose analytical delay
models for coupled interconnects that address these disadvantages. By
accounting for more wires and eschewing the Elmore delay, our delay models
achieve better accuracy than the model in [1].


title:
Extremal Myers-Perry black holes coupled to Born-Infeld electrodynamics
  in odd dimensions

abstract:
  Employing higher order perturbation theory, we find a new class of
perturbative extremal rotating black hole solutions with Born-Infeld electric
charge in odd D-dimensional spacetime. The seed solution is an odd dimensional
extremal Myers-Perry black hole with equal angular momenta to which a
perturbative nonlinear electric Born-Infeld field charge q is added maintaining
the extremality condition. The perturbations are performed up to third order.
We also study some physical properties of these black holes. In particular, it
is shown that the values of the gyromagnetic ratio of the black holes are
modified by the perturbative parameter q and the Born-Infeld parameter {\beta}.


title:
Explicit left orders on free groups extending the lexicographic order on
  free monoids

abstract:
  For every finitely generated free group we construct an explicit left order
extending the lexicographic order on the free monoid generated by the positive
letters. The order is defined by a left, free action on the orbit of 0 of a
free group of piecewise linear homeomorphisms of the line. The membership in
the positive cone is decidable in linear time in the length of the input word.
The positive cone forms a context-free language closed under word reversal.


title: k-d Match: A Fast Matching Algorithm for Sheared Stellar Samples

abstract:
  This paper presents new and efficient algorithms for matching stellar
catalogues where the transformation between the coordinate systems of the two
catalagoues is unknown and may include shearing. Finding a given object whether
a star or asterism from the first catalogue in the second is logarithmic in
time rather than polynomial, yielding a dramatic speed up relative to a naive
implementation. Both acceleration of the matching algorithm and the ability to
solve for arbitrary affine transformations not only will allow the registration
of stellar catalogues and images that are now impossible to use but also will
find applications in machine vision and other imaging applications.


title:
Multiscale Hybrid Non-local Means Filtering Using Modified Similarity
  Measure

abstract:
  A new multiscale implementation of non-local means filtering for image
denoising is proposed. The proposed algorithm also introduces a modification of
similarity measure for patch comparison. The standard Euclidean norm is
replaced by weighted Euclidean norm for patch based comparison. Assuming the
patch as an oriented surface, notion of normal vector patch is being associated
with each patch. The inner product of these normal vector patches is then used
in weighted Euclidean distance of photometric patches as the weight factor. The
algorithm involves two steps: The first step is multiscale implementation of an
accelerated non-local means filtering in the stationary wavelet domain to
obtain a refined version of the noisy patches for later comparison. This step
is inspired by a preselection phase of finding similar patches in various
non-local means approaches. The next step is to apply the modified non-local
means filtering to the noisy image using the reference patches obtained in the
first step. These refined patches contain less noise, and consequently the
computation of normal vectors and partial derivatives is more accurate.
Experimental results indicate equivalent or better performance of proposed
algorithm as compared to various state of the art algorithms.


title: A Fast Semidefinite Approach to Solving Binary Quadratic Problems

abstract:
  Many computer vision problems can be formulated as binary quadratic programs
(BQPs). Two classic relaxation methods are widely used for solving BQPs,
namely, spectral methods and semidefinite programming (SDP), each with their
own advantages and disadvantages. Spectral relaxation is simple and easy to
implement, but its bound is loose. Semidefinite relaxation has a tighter bound,
but its computational complexity is high for large scale problems. We present a
new SDP formulation for BQPs, with two desirable properties. First, it has a
similar relaxation bound to conventional SDP formulations. Second, compared
with conventional SDP methods, the new SDP formulation leads to a significantly
more efficient and scalable dual optimization approach, which has the same
degree of complexity as spectral methods. Extensive experiments on various
applications including clustering, image segmentation, co-segmentation and
registration demonstrate the usefulness of our SDP formulation for solving
large-scale BQPs.


title: Evidence of Electron Neutrino Appearance in a Muon Neutrino Beam

abstract:
  The T2K collaboration: reports evidence for electron neutrino appearance at
the atmospheric mass splitting, |\Delta m_{32}^2|=2.4x10^{-3} eV^2. An excess
of electron neutrino interactions over background is observed from a muon
neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK)
detector 295 km from the beam's origin. Signal and background predictions are
constrained by data from near detectors located 280 m from the neutrino
production target. We observe 11 electron neutrino candidate events at the SK
detector when a background of 3.3\pm0.4(syst.) events is expected. The
background-only hypothesis is rejected with a p-value of 0.0009 (3.1\sigma),
and a fit assuming \nu_{\mu}->\nu_e oscillations with sin^2(2\theta_{23})=1,
\delta_{CP}=0 and |\Delta m_{32}^2|=2.4x10^{-3} eV^2 yields
sin^2(2\theta_{13})=0.088^{+0.049}_{-0.039}(stat.+syst.).


title:
Development of a MATLAB/STK TLE Accuracy Assessment Tool, in support of
  the NASA Ames Space Traffic Management Project

abstract:
  In order to improve the effectiveness of conjunction analysis using
publically available Two Line Elements (TLEs) a number of strategies are being
investigated as part of the Space Traffic Management project at NASA Ames
Research Center. To assist in evaluating the effectiveness of these approaches
a tool was developed in the MATLAB programming language that interfaces with
the AGI Satellite Toolkit and with Microsoft Excel. The TLEs and any available
truth ephemerides are read in by the tool and propagated orbits are compared
using STK to estimate the errors. This tool is employed to determine the
covariance and investigate the growth of errors in propagating the orbit of the
CNESStella geodetic satellite. The different sources of error are assessed and
future improvements to the tool are suggested.


title:
Slow light enhanced correlated photon pair generation in
  photonic-crystal coupled-resonator optical waveguides

abstract:
  We demonstrate the generation of quantum-correlated photon pairs from a Si
photonic-crystal coupled-resonator optical waveguide. A slow-light supermode
realized by the collective resonance of high-Q and small-mode-volume
photonic-crystal cavities successfully enhanced the efficiency of the
spontaneous four-wave mixing process. The generation rate of photon pairs was
improved by two orders of magnitude compared with that of a photonic-crystal
line defect waveguide without a slow-light effect.


title: Coalitional Manipulation for Schulze's Rule

abstract:
  Schulze's rule is used in the elections of a large number of organizations
including Wikimedia and Debian. Part of the reason for its popularity is the
large number of axiomatic properties, like monotonicity and Condorcet
consistency, which it satisfies. We identify a potential shortcoming of
Schulze's rule: it is computationally vulnerable to manipulation. In
particular, we prove that computing an unweighted coalitional manipulation
(UCM) is polynomial for any number of manipulators. This result holds for both
the unique winner and the co-winner versions of UCM. This resolves an open
question stated by Parkes and Xia (2012). We also prove that computing a
weighted coalitional manipulation (WCM) is polynomial for a bounded number of
candidates. Finally, we discuss the relation between the unique winner UCM
problem and the co-winner UCM problem and argue that they have substantially
different necessary and sufficient conditions for the existence of a successful
manipulation.


title: Adversary Lower Bound for the Orthogonal Array Problem

abstract:
  We prove a quantum query lower bound \Omega(n^{(d+1)/(d+2)}) for the problem
of deciding whether an input string of size n contains a k-tuple which belongs
to a fixed orthogonal array on k factors of strength d<=k-1 and index 1,
provided that the alphabet size is sufficiently large. Our lower bound is tight
when d=k-1.
  The orthogonal array problem includes the following problems as special
cases: k-sum problem with d=k-1, k-distinctness problem with d=1, k-pattern
problem with d=0, (d-1)-degree problem with 1<=d<=k-1, unordered search with
d=0 and k=1, and graph collision with d=0 and k=2.


title:
Study on X(3872) from effective field theory with pion exchange
  interaction

abstract:
  We study $D\bar{D}^*$ ($D^*\bar{D}$) scattering in the framework of
unitarized heavy meson chiral perturbation theory with pion exchange and a
contact interaction. $^3S_1-$$^3D_1$ mixing effects are taken into account. A
loosely bound state X(3872), with the pole position being
$M_{pole}=(3871.70-i0.39)\mathrm{MeV}$, is found. The result is not sensitive
to the strength of the contact interaction. Our calculation provides a
theoretical confirmation of the existence of the $1^{++}$ state X(3872). The
light quark mass dependence of the pole position indicates it has a
predominately $D\bar{D}^*$ ($D^*\bar{D}$) molecular nature. When the $\pi$ mass
is larger than 142 MeV, the pole disappears which makes impossible the lattice
simulation of this state at large quark mass.


title: 4-Regular oriented graphs with optimum skew energy

abstract:
  Let $G$ be a simple undirected graph, and $G^\sigma$ be an oriented graph of
$G$ with the orientation $\sigma$ and skew-adjacency matrix $S(G^\sigma)$. The
skew energy of the oriented graph $G^\sigma$, denoted by
$\mathcal{E}_S(G^\sigma)$, is defined as the sum of the absolute values of all
the eigenvalues of $S(G^\sigma)$. In this paper, we characterize the underlying
graphs of all 4-regular oriented graphs with optimum skew energy and give
orientations of these underlying graphs such that the skew energy of the
resultant oriented graphs indeed attain optimum. It should be pointed out that
there are infinitely many 4-regular connected optimum skew energy oriented
graphs, while the 3-regular case only has two graphs: $K_4$ the complete graph
on 4 vertices and $Q_3$ the hypercube.


title: Phase-Aligned Space-Time Coding for a Single Stream MIMO system

abstract:
  We present a phase-aligned space-time coding scheme that expands the original
Alamouti codeword to three or four transmit antennas ($N_t = 3$ or 4) with
phase alignment. With $1 \sim 2$ bits feedback for the phase information, the
fundamental performance penalty of $10log_{10}(N_t)$ dB of orthogonal
space-time coding compared to the optimum beamforming is reduced by 1 dB (for
$N_t=3$) or 2 dB (for $N_t = 4$) on average. With the proposed scheme, the full
diversity order of $N_t$ is achievable, whereas the receiver architecture
remains the same as the legacy Alamouti decoding with codeword size of two,
since the spatial expansion is transparent to the receiver. Our results show
the proposed scheme outperforms open-loop space-time coding for three or four
transmit antennas by more than 3 dB.


title: Electron-hole symmetry and solutions of Richardson pairing model

abstract:
  Richardson approach provides an exact solution of the pairing Hamiltonian.
This Hamiltonian is characterized by the electron-hole pairing symmetry, which
is however hidden in Richardson equations. By analyzing this symmetry and using
an additional conjecture, fulfilled in solvable limits, we suggest a simple
expression of the ground state energy for an equally-spaced energy-level model,
which is applicable along the whole crossover from the superconducting state to
the pairing fluctuation regime. Solving Richardson equations numerically, we
demonstrate a good accuracy of our expression.

categories: cond-mat.supr-con cond-mat.mes-hall math-ph math.MP nlin.SI


title: Can the "standard" unitarized Regge models describe the TOTEM data?

abstract:
  The standard Regge poles are considered as inputs for two unitarization
methods: eikonal and U-matrix. It is shown that only models with three input
pomerons and two input odderons can describe the high energy data on $pp$ and
$\bar pp$ elastic scattering including the new data from Tevatron and LHC.
However, it seems that the both considered models (eikonal and U-matrix)
require a further modification (e.g., to explore nonlinear reggeon trajectories
and/or nonexponential vertex functions) for a more satisfactory description of
the data at 19.0 GeV$\leq \sqrt{s}\leq$ 7 TeV and 0.01 $\leq |t|\leq $14.2
GeV$^{2}$.


title: Minimal surfaces and eigenvalue problems

abstract:
  We show that metrics that maximize the k-th Steklov eigenvalue on surfaces
with boundary arise from free boundary minimal surfaces in the unit ball. We
prove several properties of the volumes of these minimal submanifolds. For free
boundary minimal submanifolds in the ball we show that the boundary volume is
reduced up to second order under conformal transformations of the ball. For
two-dimensional stationary integer multiplicity rectifiable varifolds that are
stationary for deformations that preserve the ball, we prove that the boundary
length is reduced under conformal transformations. We also give an overview of
some of the known results on extremal metrics of the Laplacian on closed
surfaces, and give a survey of our recent results from [FS2] on extremal
metrics for Steklov eigenvalues on compact surfaces with boundary.


title:
A remark on the permutation representations afforded by the embeddings
  of $O_{2m}^\pm(2^f)$ in $Sp_{2m}(2^f)$

abstract:
  We show that the permutation module over $\mathbb{C}$ afforded by the action
of $Sp_{2m}(2^f)$ on its natural module is isomorphic to the permutation module
over $\mathbb{C}$ afforded by the action of $Sp_{2m}(2^f)$ on the union of the
right cosets of $O_{2m}^+(2^f)$ and $O_{2m}^-(2^f)$.


title:
Compactness and rigidity of K\"{a}hler surfaces with constant scalar
  curvature

abstract:
  A compactness theorem is proved for a family of K\"{a}hler surfaces with
constant scalar curvature and volume bounded from below, diameter bounded from
above, Ricci curvature bounded and the signature bounded from below.
Furthermore, a splitting theorem and some rigidity theorems are proved for
Einstein-Maxwell systems.


title:
An inverse spectral problem related to the Geng-Xue two-component peakon
  equation

abstract:
  We solve a spectral and an inverse spectral problem arising in the
computation of peakon solutions to the two-component PDE derived by Geng and
Xue as a generalization of the Novikov and Degasperis-Procesi equations. Like
the spectral problems for those equations, this one is of a 'discrete cubic
string' type -- a nonselfadjoint generalization of a classical inhomogeneous
string -- but presents some interesting novel features: there are two Lax
pairs, both of which contribute to the correct complete spectral data, and the
solution to the inverse problem can be expressed using quantities related to
Cauchy biorthogonal polynomials with two different spectral measures. The
latter extends the range of previous applications of Cauchy biorthogonal
polynomials to peakons, which featured either two identical, or two closely
related, measures. The method used to solve the spectral problem hinges on the
hidden presence of oscillatory kernels of Gantmacher-Krein type implying that
the spectrum of the boundary value problem is positive and simple. The inverse
spectral problem is solved by a method which generalizes, to a nonselfadjoint
case, M. G. Krein's solution of the inverse problem for the Stieltjes string.


title: Revealing dressed-quarks via the proton's charge distribution

abstract:
  The proton is arguably the most fundamental of Nature's readily detectable
building blocks. It is at the heart of every nucleus and has never been
observed to decay. It is nevertheless a composite object, defined by its
valence-quark content: u+u+d -- i.e., two up (u) quarks and one down (d) quark;
and the manner by which they influence, inter alia, the distribution of charge
and magnetisation within this bound-state. Much of novelty has recently been
learnt about these distributions; and it now appears possible that the proton's
momentum-space charge distribution possesses a zero. Experiments in the coming
decade should answer critical questions posed by this and related advances; and
we explain how such new information may assist in charting the origin and
impact of key emergent phenomena within the strong interaction. Specifically,
we show that the possible existence and location of a zero in the proton's
electric form factor are a measure of nonperturbative features of the
quark-quark interaction in the Standard Model, with particular sensitivity to
the running of the dressed-quark mass.


title:
Representations of rational Cherednik algebras of G(m,r,n) in positive
  characteristic

abstract:
  We study lowest-weight irreducible representations of rational Cherednik
algebras attached to the complex reflection groups G(m,r,n) in characteristic
p. Our approach is mostly from the perspective of commutative algebra. By
studying the kernel of the contravariant bilinear form on Verma modules, we
obtain formulas for Hilbert series of irreducible representations in a number
of cases, and present conjectures in other cases. We observe that the form of
the Hilbert series of the irreducible representations and the generators of the
kernel tend to be determined by the value of n modulo p, and are related to
special classes of subspace arrangements. Perhaps the most novel (conjectural)
discovery from the commutative algebra perspective is that the generators of
the kernel can be given the structure of a "matrix regular sequence" in some
instances, which we prove in some small cases.


title:
Coexistence of Near-Field and Far-Field Sources: the Angular Resolution
  Limit

abstract:
  Passive source localization is a well known inverse problem in which we
convert the observed measurements into information about the direction of
arrivals. In this paper we focus on the optimal resolution of such problem.
More precisely, we propose in this contribution to derive and analyze the
Angular Resolution Limit (ARL) for the scenario of mixed Near-Field (NF) and
Far-Field (FF) Sources. This scenario is relevant to some realistic situations.
We base our analysis on the Smith's equation which involves the Cram\'er-Rao
Bound (CRB). This equation provides the theoretical ARL which is independent of
a specific estimator. Our methodology is the following: first, we derive a
closed-form expression of the CRB for the considered problem. Using these
expressions, we can rewrite the Smith's equation as a 4-th order polynomial by
assuming a small separation of the sources. Finally, we derive in closed-form
the analytic ARL under or not the assumption of low noise variance. The
obtained expression is compact and can provide useful qualitative informations
on the behavior of the ARL.


title: Hypergeometric solutions to the symmetric q-Painlev\'e equations

abstract:
  We consider the symmetric q-Painlev\'e equations derived from the birational
representation of affine Weyl groups by applying the projective reduction and
construct the hypergeometric solutions. Moreover, we discuss continuous limits
of the symmetric q-Painlev\'e equations to Painlev\'e equations together with
their hypergeometric solutions.


title: Angular resolution limit for deterministic correlated sources

abstract:
  This paper is devoted to the analysis of the angular resolution limit (ARL),
an important performance measure in the directions-of-arrival estimation
theory. The main fruit of our endeavor takes the form of an explicit,
analytical expression of this resolution limit, w.r.t. the angular parameters
of interest between two closely spaced point sources in the far-field region.
As by-products, closed-form expressions of the Cram\'er-Rao bound have been
derived. Finally, with the aid of numerical tools, we confirm the validity of
our derivation and provide a detailed discussion on several enlightening
properties of the ARL revealed by our expression, with an emphasis on the
impact of the signal correlation.


title:
The Eclipsing Binary Cepheid OGLE-LMC-CEP-0227 in the Large Magellanic
  Cloud: pulsation modelling of light and radial velocity curves

abstract:
  We performed a new and accurate fit of light and radial velocity curves of
the Large Magellanic Cloud (LMC) Cepheid --OGLE-LMC-CEP-0227-- belonging to a
detached double-lined eclipsing binary system. We computed several sets of
nonlinear, convective models covering a broad range in stellar mass, effective
temperature and in chemical composition. The comparison between theory and
observations indicates that current theoretical framework accounts for
luminosity --V and I band-- and radial velocity variations over the entire
pulsation cycle. Predicted pulsation mass --M=4.14+-0.06 Mo-- and mean
effective temperature --Te=6100+-50 K-- do agree with observed estimates with
an accuracy better than 1 sigma. The same outcome applies, on average, to the
luminosity amplitudes and to the mean radius. We find that the best fit
solution requires a chemical composition that is more metal--poor than typical
LMC Cepheids (Z=0.004 vs 0.008) and slightly helium enhanced (Y=0.27 vs 0.25),
but the sensitivity to He abundance is quite limited. Finally, the best fit
model reddening --E(V-I)=0.171+-0.015 mag-- and the true distance modulus
corrected for the barycenter of the LMC --mu_{0,LMC}=18.50+-0.02+-0.10 (syst)
mag--, agree quite well with similar estimates in the recent literature.


title:
Shape invariant model approach for functional data analysis in
  uncertainty and sensitivity studies

abstract:
  Dynamic simulators model systems evolving over time. Often, it operates
iteratively over fixed number of time-steps. The output of such simulator can
be considered as time series or discrete functional outputs. Metamodeling is an
e ective method to approximate demanding computer codes. Numerous metamodeling
techniques are developed for simulators with a single output. Standard approach
to model a dynamic simulator uses the same method also for multi-time series
outputs: the metamodel is evaluated independently at every time step. This can
be computationally demanding in case of large number of time steps. In some
cases, simulator outputs for di erent combinations of input parameters have
quite similar behaviour. In this paper, we propose an application of shape
invariant model approach to model dynamic simulators. This model assumes a
common pattern shape curve and curve-specific di erences in amplitude and
timing are modelled with linear transformations. We provide an e cient
algorithm of transformation parameters estimation and subsequent prediction
algorithm. The method was tested with a CO2 storage reservoir case using an
industrial commercial simulator and compared with a standard single step
approach. The method provides satisfactory predictivity and it does not depend
on the number of involved time steps.


title: Higher bifurcation currents, neutral cycles and the Mandelbrot set

abstract:
  We prove that given any $\theta_1,\ldots,\theta_{2d-2}\in \R\setminus\Z$, the
support of the bifurcation measure of the moduli space of degree $d$ rational
maps coincides with the closure of classes of maps having $2d-2$ neutral cycles
of respective multipliers $e^{2i\pi\theta_1},\ldots,e^{2i\pi\theta_{2d-2}}$. To
this end, we generalize a famous result of McMullen, proving that homeomorphic
copies of $(\partial \Mand)^{k}$ are dense in the support of the
$k^{th}$-bifurcation current $T^k_\bif$ in general families of rational maps,
where $\Mand$ is the Mandelbrot set. As a consequence, we also get sharp
dimension estimates for the supports of the bifurcation currents in any family.


title:
Quality of Service in Wireless Cellular Networks Subject to Log-Normal
  Shadowing

abstract:
  Shadowing is believed to degrade the quality of service (QoS) in wireless
cellular networks. Assuming log-normal shadowing, and studying mobile's
path-loss with respect to the serving base station (BS) and the corresponding
interference factor (the ratio of the sum of the path-gains form interfering
BS's to the path-gain from the serving BS), which are two key ingredients of
the analysis and design of the cellular networks, we discovered a more subtle
reality. We observe, as commonly expected, that a strong variance of the
shadowing increases the mean path-loss with respect to the serving BS, which in
consequence, may compromise QoS. However, in some cases, an increase of the
variance of the shadowing can significantly reduce the mean interference factor
and, in consequence, improve some QoS metrics in interference limited systems,
provided the handover policy selects the BS with the smallest path loss as the
serving one. We exemplify this phenomenon, similar to stochastic resonance and
related to the "single big jump principle" of the heavy-tailed log-nornal
distribution, studying the blocking probability in regular, hexagonal networks
in a semi-analytic manner, using a spatial version of the Erlang's loss formula
combined with Kaufman-Roberts algorithm. More detailed probabilistic analysis
explains that increasing variance of the log-normal shadowing amplifies the
ratio between the strongest signal and all other signals thus reducing the
interference. The above observations might shed new light, in particular on the
design of indoor communication scenarios.


title:
Efficient Generation of Correctness Certificates for the Abstract Domain
  of Polyhedra

abstract:
  Polyhedra form an established abstract domain for inferring runtime
properties of programs using abstract interpretation. Computations on them need
to be certified for the whole static analysis results to be trusted. In this
work, we look at how far we can get down the road of a posteriori verification
to lower the overhead of certification of the abstract domain of polyhedra. We
demonstrate methods for making the cost of inclusion certificate generation
negligible. From a performance point of view, our single-representation,
constraints-based implementation compares with state-of-the-art
implementations.


title:
A Comparison and Unification of Ellipsoidal Statistical and Shakhov BGK
  Models

abstract:
  The Ellipsoidal Statistical model (ES-model) and the Shakhov model (S-model)
are constructed for the correction of Prandtl number of the original BGK model
through the modification of stress and heat flux. Even though in the continuum
flow regime, both models can give the same Navier-Stokes equations with correct
Prandtl number, their modification of the collision term may have different
dynamic effect in the non-equilibrium transition flow regimes. With the
introduction of one free parameter, a generalized kinetic model with the
combination of the ES-model and S-model can be developed, and this new model
can get the correct Navier-Stokes equations in the continuum flow regime as
well, but with abundant dynamic effect through the adjustment of the new degree
of freedom. In order to validate the generalized model, a numerical method
based on the unified gas kinetic scheme (UGKS) has been developed for the new
model. The physical performance of the new model with the variation of the free
parameter has been tested, where the ES-model and S-model become the limiting
cases. In transition flow regime, many physical problems, i.e., the shock
structure and micro-flows, have been studied using the generalized model. With
a careful choice of the free parameter, good results can be achieved for most
test cases. The overall conclusion is that the S-model predicts more accurate
numerical solutions in most tough test cases presented in this paper than the
ES-model, while ES-model performs better in the cases when the flow is mostly
driven by heat, such as a channel flow with large boundary temperature
variations at high Knudsen number. The numerical study demonstrates the
necessity of developing such a generalized model. With the inclusion of one
more freedom, in the transition regime the new kinetic model may provide more
accurate solution than the ES and Shakhov models.


title: Fine structure of the lowest Landau level in suspended trilayer graphene

abstract:
  Magneto-transport experiments on ABC-stacked suspended trilayer graphene
reveal a complete splitting of the twelve-fold degenerated lowest Landau level,
and, in particular, the opening of an exchange-driven gap at the charge
neutrality point. A quantitative analysis of distinctness of the quantum Hall
plateaus as a function of field yields a hierarchy of the filling factors:
\nu=6, 4, and 0 are the most pronounced, followed by \nu=3, and finally \nu=1,
2 and 5. Apart from the appearance of a \nu=4 state, which is probably caused
by a layer asymmetry, this sequence is in agreement with Hund's rules for
ABC-stacked trilayer graphene.


title: Cylindrical model structures

abstract:
  We build a model structure from the simple point of departure of a structured
interval in a monoidal category - more generally, a structured cylinder and a
structured co-cylinder in a category.


title: Differentiability of Mather's $\beta$-function vs Ma\~n\'e's conjecture

abstract:
  We prove that if a time-periodic Tonelli Lagrangian on a closed manifold $M$
satisfies a strong version of the Differentiability Problem for Mather's
$\beta$-function, then the Legendre transforms of rational homology classes are
dense in the first cohomology of $M$, which is a first step towards Ma\~n\'e's
conjecture.


title:
Patch-based Probabilistic Image Quality Assessment for Face Selection
  and Improved Video-based Face Recognition

abstract:
  In video based face recognition, face images are typically captured over
multiple frames in uncontrolled conditions, where head pose, illumination,
shadowing, motion blur and focus change over the sequence. Additionally,
inaccuracies in face localisation can also introduce scale and alignment
variations. Using all face images, including images of poor quality, can
actually degrade face recognition performance. While one solution it to use
only the "best" subset of images, current face selection techniques are
incapable of simultaneously handling all of the abovementioned issues. We
propose an efficient patch-based face image quality assessment algorithm which
quantifies the similarity of a face image to a probabilistic face model,
representing an "ideal" face. Image characteristics that affect recognition are
taken into account, including variations in geometric alignment (shift,
rotation and scale), sharpness, head pose and cast shadows. Experiments on
FERET and PIE datasets show that the proposed algorithm is able to identify
images which are simultaneously the most frontal, aligned, sharp and well
illuminated. Further experiments on a new video surveillance dataset (termed
ChokePoint) show that the proposed method provides better face subsets than
existing face selection techniques, leading to significant improvements in
recognition accuracy.


title: DEPFET Pixels as a Vertex Detector for the Belle II Experiment

abstract:
  Currently the heavy flavour factory KEKB located at the KEK accelerator
centre in Tsukuba, Japan, is being upgraded to the Super KEKB factory, aiming
for a substantially higher luminosity of 8x10^35 cm^-2 s^-1. This by a factor
of 40 increased luminosity requires significant modifications of the Belle
detector. The vertex detector needs to be redesigned and, besides a four-layer
silicon strip detector, a pixel detector based on the DEPFET technology will be
installed closest to the interaction point. The requirements for this pixel
detector, the DEPFET technology and the current status of the pixel detector
will be presented in this paper.


title:
Coverings by few monochromatic pieces - a transition between two Ramsey
  problems

abstract:
  The typical problem in (generalized) Ramsey theory is to find the order of
the largest monochromatic member of a family F (for example matchings, paths,
cycles, connected subgraphs) that must be present in any edge coloring of a
complete graph K_n with t colors. Another area is to find the minimum number of
monochromatic members of F that partition or cover the vertex set of every edge
colored complete graph. Here we propose a problem that connects these areas:
for fixed positive integers s,t, at least how many vertices can be covered by
the vertices of no more than s monochromatic members of F in every edge
coloring of K_n with t colors. Several problems and conjectures are presented,
among them a possible extension of a well-known result of Cockayne and Lorimer
on monochromatic matchings for which we prove an initial step: in case of s=t-1
we determine how many vertices can be covered by s monochromatic matchings in
every t-coloring of K_n.


title: Timing in chemical reaction networks

abstract:
  Chemical reaction networks (CRNs) formally model chemistry in a well-mixed
solution. CRNs are widely used to describe information processing occurring in
natural cellular regulatory networks, and with upcoming advances in synthetic
biology, CRNs are a promising programming language for the design of artificial
molecular control circuitry. Due to a formal equivalence between CRNs and a
model of distributed computing known as population protocols, results transfer
readily between the two models.
  We show that if a CRN respects finite density (at most O(n) additional
molecules can be produced from n initial molecules), then starting from any
dense initial configuration (all molecular species initially present have
initial count Omega(n), where n is the initial molecular count and volume),
then every producible species is produced in constant time with high
probability.
  This implies that no CRN obeying the stated constraints can function as a
timer, able to produce a molecule, but doing so only after a time that is an
unbounded function of the input size. This has consequences regarding an open
question of Angluin, Aspnes, and Eisenstat concerning the ability of population
protocols to perform fast, reliable leader election and to simulate arbitrary
algorithms from a uniform initial state.


title: On the Two Conjectures of the Wiener Index

abstract:
  The Wiener index of a graph, which is the sum of the distances between all
pairs of vertices, has been well studied. Recently, Sills and Wang in 2012
proposed two conjectures on the maximal Wiener index of trees with a given
degree sequence. This note proves one of the two conjectures and disproves the
other.


title:
Sch\"onemann-Eisenstein-Dumas-type irreducibility conditions that use
  arbitrarily many prime numbers

abstract:
  The famous irreducibility criteria of Sch\"onemann-Eisenstein and Dumas rely
on information on the divisibility of the coefficients of a polynomial by a
single prime number. In this paper we provide several irreducibility criteria
of Sch\"onemann-Eisenstein-Dumas-type for polynomials with integer
coefficients, criteria that are given by some divisibility conditions for their
coefficients with respect to arbitrarily many prime numbers. A special
attention will be paid to those irreducibility criteria that require
information on the divisibility of the coefficients by two distinct prime
numbers.


title:
Synchronization of an array of spin torque nano oscillators in periodic
  applied external magnetic field

abstract:
  Considering an array of spin torque transfer nano oscillators (STNOs), we
have investigated the synchronization property of the system under the action
of a common periodically driven applied external magnetic field by numerically
analyzing the underlying system of Landau-Lifshitz-Gilbert-Slonczewski (LLGS)
equations for the macro-spin variables. We find the novel result that the
applied external magnetic field can act as a medium to induce synchronization
of periodic oscillations, both in-phase and anti-phase, even without coupling
through spin current, thereby leading to the exciting possibility of
enhancement of microwave power in a straightforward way.


title: On the invariance of the relative rest in doubly special relativity

abstract:
  In the framework of the most-studied doubly special relativity models the use
of the naive formula $v=dE/dp$ has been argued to lead to inconsistencies
connected to different rules of transformation, under boosts, of particles with
the same energy but with different masses. In this paper we show that, at least
in 1+1 dimensions, doubly special relativity can be formulated in such a way
that the formula $v=dE/dp$ is fully consistent with the invariance of the
relative rest, easily fitting to the relativity principle. It is also argued
that, always in 1+1d, is not necessary to renounce to the usual (commutative)
Minkowski space-time endowed with energy-independent boost transformations. The
compatibility of the approach with superluminal propagation, with linear
addition rule for energy, and possible extensions to 3+1 dimensions are also
discussed.


title: Testing the characteristics of a L\'evy process

abstract:
  For $n$ equidistant observations of a L\'evy process at time distance
$\Delta_n$ we consider the problem of testing hypotheses on the volatility, the
jump measure and its Blumenthal-Getoor index in a non- or semiparametric
manner. Asymptotically as $n\to\infty$ we allow for both, the high-frequency
regime $\Delta_n=\frac1n$ and the low-frequency regime $\Delta_n=1$ as well as
intermediate cases. The approach via empirical characteristic function unifies
existing theory and sheds new light on diverse results. Particular emphasis is
given to asymptotic separation rates which reveal the complexity of these
basic, but surprisingly non-standard inference questions.


title: C Language Extensions for Hybrid CPU/GPU Programming with StarPU

abstract:
  Modern platforms used for high-performance computing (HPC) include machines
with both general-purpose CPUs, and "accelerators", often in the form of
graphical processing units (GPUs). StarPU is a C library to exploit such
platforms. It provides users with ways to define "tasks" to be executed on CPUs
or GPUs, along with the dependencies among them, and by automatically
scheduling them over all the available processing units. In doing so, it also
relieves programmers from the need to know the underlying architecture details:
it adapts to the available CPUs and GPUs, and automatically transfers data
between main memory and GPUs as needed. While StarPU's approach is successful
at addressing run-time scheduling issues, being a C library makes for a poor
and error-prone programming interface. This paper presents an effort started in
2011 to promote some of the concepts exported by the library as C language
constructs, by means of an extension of the GCC compiler suite. Our main
contribution is the design and implementation of language extensions that map
to StarPU's task programming paradigm. We argue that the proposed extensions
make it easier to get started with StarPU,eliminate errors that can occur when
using the C library, and help diagnose possible mistakes. We conclude on future
work.


title:
Production cross sections of gamma-rays, electrons, and positrons in p-p
  collisions

abstract:
  Because the production cross sections of gamma-rays, electrons, and positrons
made in p-p collisions, $\sigma_{pp\rightarrow \gamma}$ and
$\sigma_{pp\rightarrow {e}^\pm}$, respectively, are kinematically equivalent
with respect to the parent pion-production cross section $\sigma_{pp\rightarrow
\pi}$, we obtain $\sigma_{pp\rightarrow {e}^\pm}$ directly from the machine
data on $\sigma_{pp\rightarrow \gamma}$. In Sato et al. (2012), we give
explicitly $\sigma_{pp\rightarrow \gamma}$, reproducing quite well the
accelerator data with LHC, namely $\sigma_{pp\rightarrow {e}^\pm}$ is
applicable enough over the wide energy range from GeV to 20\,PeV for projectile
proton energy. We dicuss in detail the relation between the cross sections, and
present explicitly $\sigma_{pp\rightarrow {e}^\pm}$ that are valid into the PeV
electron energy.


title:
Remarks on the Cauchy problem for the one-dimensional quadratic
  (fractional) heat equation

abstract:
  We prove that the Cauchy problem associated with the one dimensional
quadratic (fractional) heat equation: $u_t=D_x^{2\alpha} u \mp u^2,\; t\in
(0,T),\; x\in \R$ or $ \T $, with $ 0<\alpha\le 1 $ is well-posed in $ H^s $
for $ s\ge \max(-\alpha,1/2-2\alpha) $ except in the case $ \alpha=1/2 $ where
it is shown to be well-posed for $ s>-1/2 $ and ill-posed for $ s=-1/2 $. As a
by-product we improve the known well-posedness results for the heat equation
($\alpha=1$) by reaching the end-point Sobolev index $ s=-1 $. Finally, in the
case $ 1/2<\alpha\le 1 $, we also prove optimal results in the Besov spaces
$B^{s,q}_2.$


title: On the BP<n>-cohomology of elementary abelian p-groups

abstract:
  The structure of the BP<n>-cohomology of elementary abelian p-groups is
studied, obtaining a presentation expressed in terms of BP-cohomology and mod-p
singular cohomology, using the Milnor derivations.
  The arguments are based on a result on multi-Koszul complexes which is
related to Margolis's criterion for freeness of a graded module over an
exterior algebra.


title: 2MTF II. New Parkes 21-cm observations of 303 southern galaxies

abstract:
  We present new 21-cm neutral hydrogen (HI) observations of spiral galaxies
for the 2MASS Tully Fisher (2MTF) survey. Using the 64-m Parkes radio telescope
multibeam system we obtain 152 high signal-to-noise HI spectra from which we
extract 148 high-accuracy (< 5% error) velocity widths and derive reliable
rotation velocities. The observed sample consists of 303 southern (\delta <
-40\deg) galaxies selected from the MASS Redshift Survey (2MRS) with K_s <11.25
mag, cz < 10,000 km/s and axis ratio b/a < 0.5. The HI observations reported in
this paper will be combined with new HI spectra from the Green Bank and Arecibo
telescopes, together producing the most uniform Tully-Fisher survey ever
constructed (in terms of sky coverage). In particular, due to its near infrared
selection, 2MTF will be significantly more complete at low Galactic latitude
(|b|<15\deg) and will provide a more reliable map of peculiar velocities in the
local universe.


title: An instance of Vaught's conjecture using algebraic logic

abstract:
  Let \phi be a first order formula and M be a countable model. \phi^M denotes
the set of all assignments that satisfy \phi in M. Let M, N be countable
models. A formula \phi distinguishes these models if |\phi^M|\neq |\phi^N|. We
show that the number of distinguishable countable models for a complete
countable first order theory, satisfies the Glimm Effross dichotomy, hence also
Vaught's conjecture. The proof in the presence of equality is fairly easy,
though we need infinite conjunctions to implement it and somewhat heavy
theorems from descriptive set theory. However, the case without equality seems
to be much more difficult (because we cannot count without equality) and in
this case algebraic logic comes to our rescue via the representation theory of
locally finite quasi polyadic algebras. We show that the equivalence relation
induced by such (indistinguishable) models is a Borel subset of the product of
the Stone Polish space (consisting of ultarfilters corresponding to models)
with itself.
  We also formuate and prove a Vaught's theorem for certian infinitary
extensions of first order logic via the representation theory of dimension
complemented algebras.
  In all case we also count the number of non isomorphic models omitting < covK
many non isolated types (the latter is the least cardinal such that the Baire
Category theorem fails and also the largest cardinal such tha Martin's axiom
restrcited to countable Boolean algebra hold.) In such cases, for locally
finite algebras and dimension complemented ones we obtain the same number of
non-ismorphic distinguishable models.


title: Self-intersections of trajectories of Lorentz process

abstract:
  We study the asymptotic behaviour of the number of self-intersections of a
trajectory of a periodic planar Lorentz process with strictly convex obstacles
and finite horizon. We give precise estimates for its expectation and its
variance. As a consequence, we establish the almost sure convergence of the
self-intersections with a suitable normalization.


title:
k-Leibniz algebras from lower order ones: from Lie triple to Lie l-ple
  systems

abstract:
  Two types of higher order Lie $\ell$-ple systems are introduced in this
paper. They are defined by brackets with $\ell > 3$ arguments satisfying
certain conditions, and generalize the well known Lie triple systems. One of
the generalizations uses a construction that allows us to associate a
$(2n-3)$-Leibniz algebra $\fL$ with a metric $n$-Leibniz algebra $\tilde{\fL}$
by using a $2(n-1)$-linear Kasymov trace form for $\tilde{\fL}$. Some specific
types of $k$-Leibniz algebras, relevant in the construction, are introduced as
well. Both higher order Lie $\ell$-ple generalizations reduce to the standard
Lie triple systems for $\ell=3$.


title:
Improved Anomaly Detection in Crowded Scenes via Cell-based Analysis of
  Foreground Speed, Size and Texture

abstract:
  A robust and efficient anomaly detection technique is proposed, capable of
dealing with crowded scenes where traditional tracking based approaches tend to
fail. Initial foreground segmentation of the input frames confines the analysis
to foreground objects and effectively ignores irrelevant background dynamics.
Input frames are split into non-overlapping cells, followed by extracting
features based on motion, size and texture from each cell. Each feature type is
independently analysed for the presence of an anomaly. Unlike most methods, a
refined estimate of object motion is achieved by computing the optical flow of
only the foreground pixels. The motion and size features are modelled by an
approximated version of kernel density estimation, which is computationally
efficient even for large training datasets. Texture features are modelled by an
adaptively grown codebook, with the number of entries in the codebook selected
in an online fashion. Experiments on the recently published UCSD Anomaly
Detection dataset show that the proposed method obtains considerably better
results than three recent approaches: MPPCA, social force, and mixture of
dynamic textures (MDT). The proposed method is also several orders of magnitude
faster than MDT, the next best performing method.


title:
Experimental observation of chaos-chaos intermittency types in spherical
  Couette flow

abstract:
  Flows between concentric, counter rotating spherical boundaries are under
investigation in the gap with size equal to inner sphere radius. Outer sphere
rotational rate is fixed, while inner sphere rotational rate has time periodic
variations. The amplitudes and frequencies of these variations are small
relative to both spheres averaged rotational rates. With amplitude increase
transition from initial periodical flow to chaos is occurred. To determine
state of the flow time series of azimuthal velocity, taken with laser Doppler
anemometry, were used. We demonstrate appearance of flow states in the form of
chaos-chaos and cycle-chaos-chaos intermittency. A procedure is considered
which allow quantitatively confirm distinct properties of different patterns of
time alternating flow state with intermittency.


title:
Is Every Irreducible Shift of Finite Type Flow Equivalent to a Renewal
  System?

abstract:
  Is every irreducible shift of finite type flow equivalent to a renewal
system? For the first time, this variation of a classic problem formulated by
Adler is investigated, and several partial results are obtained in an attempt
to find the range of the Bowen--Franks invariant over the set of renewal
systems of finite type. In particular, it is shown that the Bowen--Franks group
is cyclic for every member of a class of renewal systems known to attain all
entropies realised by shifts of finite type, and several classes of renewal
systems with non--trivial values of the invariant are constructed.


title:
Dirac fields in curved spacetime as Fermi-Hubbard model with non unitary
  tunnelings

abstract:
  In this article we show that a Dirac Hamiltonian in a curved background
spacetime can be interpreted, when discretized, as a tight binding
Fermi-Hubbard model with non unitary tunnelings. We find the form of the
nonunitary tunneling matrices in terms of the metric tensor. The main
motivation behind this exercise is the feasibility of such Hamiltonians by
means of laser assisted tunnelings in cold atomic experiments. The mapping thus
provide a physical interpretation of such Hamiltonians. We demonstrate the use
of the mapping on the example of time dependent metric in 2+1 dimensions.
Studying the spin dynamics, we find qualitative agreement with known
theoretical predictions, namely the particle pair creation in expanding
universe.


title:
Growth and texture of Spark Plasma Sintered Al2O3 ceramics: a combined
  analysis of X-rays and Electron Back Scatter Diffraction

abstract:
  Textured alumina ceramics were obtained by Spark Plasma Sintering (SPS) of
undoped commercial a-Al2O3 powders. Various parameters (density, grain growth,
grain size distribution) of the alumina ceramics, sintered at two typical
temperatures 1400{\deg}C and 1700{\deg}C, are investigated. Quantitative
textural and structural analysis, carried out using a combination of Electron
Back Scattering Diffraction (EBSD) and X-ray diffraction (XRD), are represented
in the form of mapping, and pole figures. The mechanical properties of these
textured alumina ceramics include high elastic modulus and hardness value with
high anisotropic nature, opening the door for a large range of applications


title: Uniqueness of the direct decomposition of toric manifolds

abstract:
  In this paper, we study the uniqueness of the direct decomposition of a toric
manifold. We first observe that the direct decomposition of a toric manifold as
\emph{algebraic varieties} is unique up to order of the factors. An
algebraically indecomposable toric manifold happens to decompose as smooth
manifold and no criterion is known for two toric manifolds to be diffeomorphic,
so the unique decomposition problem for toric manifolds as \emph{smooth
manifolds} is highly nontrivial and nothing seems known for the problem so far.
We prove that this problem is affirmative if the complex dimension of each
factor in the decomposition is less than or equal to two. A similar argument
shows that the direct decomposition of a smooth manifold into copies of
$\mathbb{C}P^1$ and simply connected closed smooth 4-manifolds with smooth
actions of $(S^1)^2$ is unique up to order of the factors.


title:
Competition Between Wireless Service Providers: Pricing, Equilibrium and
  Efficiency

abstract:
  As the communication network is in transition towards a commercial one
controlled by service providers (SP), the present paper considers a pricing
game in a communication market covered by several wireless access points
sharing the same spectrum and analyzes two business models: monopoly (APs
controlled by one SP) and oligopoly (APs controlled by different SPs). We use a
Stackelberg game to model the problem: SPs are the leader(s) and end users are
the followers. We prove, under certain conditions, the existence and uniqueness
of Nash equilibrium for both models and derive their expressions. In order to
compare the impact of different business models on social welfare and SPs'
profits, we define two metrics: PoCS (price of competition on social welfare)
and PoCP (price of competition on profits). For symmetric cross-AP
interferences, the tight lower bound of PoCS is 3/4, and that of PoCP is 1.


title:
Flux conservation in coherent backscattering and weak localisation of
  light

abstract:
  The standard theoretical description of coherent backscattering, accord- ing
to which maximally crossed diagrams accounting for interference between
counter- propagating path amplitudes are added on top of the incoherent
background, violates the fundamental condition of flux conservation. In
contrast to predictions of previous theories, we show that including maximally
crossed diagrams with one additional scat- tering event does not restore flux
conservation. Instead, we propose that the latter is recovered when treating
the effects of coherent backscattering and weak localisation in a unified
framework. On the basis of this framework, we demonstrate explicitly flux
conservation in leading order of the weak disorder parameter 1/(kl).