title: Applications of Large Random Matrices in Communications Engineering

abstract:
  This work gives an overview of analytic tools for the design, analysis, and
modelling of communication systems which can be described by linear vector
channels such as y = Hx+z where the number of components in each vector is
large. Tools from probability theory, operator algebra, and statistical physics
are reviewed. The survey of analytical tools is complemented by examples of
applications in communications engineering. Asymptotic eigenvalue distributions
of many classes of random matrices are given. The treatment includes the
problem of moments and the introduction of the Stieltjes transform. Free
probability theory, which evolved from non-commutative operator algebras, is
explained from a probabilistic point of view in order to better fit the
engineering community. For that purpose freeness is defined without reference
to non-commutative algebras. The treatment includes additive and multiplicative
free convolution, the R-transform, the S-transform, and the free central limit
theorem. The replica method developed in statistical physics for the purpose of
analyzing spin glasses is reviewed from the viewpoint of its applications in
communications engineering. Correspondences between free energy and mutual
information as well as energy functions and detector metrics are established.
These analytic tools are applied to the design and the analysis of linear
multiuser detectors, the modelling of scattering in communication channels with
dual antennas arrays, and the analysis of optimal detection for communication
via code-division multiple-access and/or dual antenna array channels.


title:
Ab initio simulation of complex dielectric function for dense aluminum
  plasma

abstract:
  We present calculations of frequency-dependent complex dielectric function of
dense aluminum plasma by quantum molecular dynamics method for temperatures up
to 20 kK. Analysis shows that the dependencies for real and imaginary parts can
be interpolated by the Drude formula with two effective parameters: the mean
charge of ions and the effective frequency of collisions. The rise of these
parameters with temperature deviates from simple theoretical predictions.


title: Beyond the 2nd Fermi Pulsar Catalog

abstract:
  Over thirteen times more gamma-ray pulsars have now been studied with the
Large Area Telescope on NASA's Fermi satellite than the ten seen with the
Compton Gamma-Ray Observatory in the nineteen-nineties. The large sample is
diverse, allowing better understanding both of the pulsars themselves and of
their roles in various cosmic processes. Here we explore the prospects for even
more gamma-ray pulsars as Fermi enters the 2nd half of its nominal ten-year
mission. New pulsars will naturally tend to be fainter than the first ones
discovered. Some of them will have unusual characteristics compared to the
current population, which may help discriminate between models. We illustrate a
vision of the future with a sample of six pulsars discovered after the 2nd
Fermi Pulsar Catalog was written.


title:
Complete Multiwavelength Evolution of Galactic Black Hole Transients
  During Outburst Decay I: Conditions for "Compact" Jet Formation

abstract:
  Compact, steady jets are observed in the near infrared and radio bands in the
hard state of Galactic black hole transients as their luminosity decreases and
the source moves towards a quiescent state. Recent radio observations indicate
that the jets turn off completely in the soft state, therefore multiwavelength
monitoring of black hole transients are essential to probe the formation of
jets. In this work we conducted a systematic study of all black hole transients
with near infrared and radio coverage during their outburst decays. We
characterized the timescales of changes in X-ray spectral and temporal
properties and also in near infrared and/or in radio emission. We confirmed
that state transitions occur in black hole transients at a very similar
fraction of their respective Eddington luminosities. We also found that the
near infrared flux increase that could be due to the formation of a compact jet
is delayed by a time period of days with respect to the formation of a corona.
Finally, we found a threshold disk Eddington luminosity fraction for the
compact jets to form. We explain these results with a model such that the
increase in the near infrared flux corresponds to a transition from a patchy,
small scale height corona along with an optically thin out flow to a large
scale height corona that allows for collimation of a steady compact jet. We
discuss the timescale of jet formation in terms of transport of magnetic fields
from the outer parts of the disk, and also consider two alternative
explanations for the multiwavelength emission: hot inner accretion flows and
irradiation.


title: Cloaking using complementary media in the quasistatic regime

abstract:
  Cloaking using complementary media was suggested by Lai et al. in [8]. The
study of this problem faces two difficulties. Firstly, this problem is unstable
since the equations describing the phenomenon have sign changing coefficients,
hence the ellipticity is lost. Secondly, the localized resonance, i.e., the
field explodes in some regions and remains bounded in some others, might
appear. In this paper, we give a proof of cloaking using complementary media
for a class of schemes inspired from [8] in the quasistatic regime. To handle
the localized resonance, we introduce the technique of removing localized
singularity and apply a three spheres inequality. The proof also uses the
reflecting technique in [11]. To our knowledge, this work presents the first
proof on cloaking using complementary media.


title: Clifford theory of characters in induced blocks

abstract:
  We present a new criterion to predict if a character of a finite group
extends. Let $G$ be a finite group and $p$ a prime. For $N\lhd G$, we consider
$p$-blocks $b$ and $b'$ of $N$ and ${\rm N}_N(D)$, respectively, with
$(b')^N=b$, where $D$ is a defect group of $b'$. Under the assumption that $G$
coincides with a normal subgroup $G[b]$ of $G$, which was introduced by Dade
early 1970's, we give a character correspondence between the sets of all
irreducible constituents of $\phi^G$ and those of $(\phi')^{{\rm N}_G(D)}$
where $\phi$ and $\phi'$ are irreducible Brauer characters in $b$ and $b'$,
respectively. This implies a sort of generalization of the theorem of
Harris-Kn\"orr. An important tool is the existence of certain extensions that
also helps in checking the inductive Alperin-McKay and inductive Blockwise
Alperin Weight conditions, due to the second author.


title:
Behavior-Based online Incentive Mechanism for Crowd Sensing with Budget
  Constraints

abstract:
  Crowd sensing is a new paradigm which leverages the ubiquity of
sensor-equipped mobile devices to collect data. To achieve good quality for
crowd sensing, incentive mechanisms are indispensable to attract more
participants. Most of existing mechanisms focus on the expected utility prior
to sensing, ignoring the risk of low quality solution and privacy leakage.
Traditional incentive mechanisms such as the Vickrey-Clarke-Groves (VCG)
mechanism and its variants are not applicable here. In this paper, to address
these challenges, we propose a behavior based incentive mechanism for crowd
sensing applications with budget constraints by applying sequential all-pay
auctions in mobile social networks (MSNs), not only to consider the effects of
extensive user participation, but also to maximize high quality of the context
based sensing content submission for crowd sensing platform under the budget
constraints, where users arrive in a sequential order. Through an extensive
simulation, results indicate that incentive mechanisms in our proposed
framework outperform the best existing solution.


title: Three-dimensional Microlensing

abstract:
  We study three-dimensional microlensing where two lenses are located at
different distances along the line of sight. We formulate the lens equation in
complex notations and recover several previous results. There are in total
either 4 or 6 images, with an equal number of images with positive and negative
parities. We find that the sum of signed magnifications for six image
configurations is unity. Furthermore, we show that the light curves can be
qualitatively different from those for binary lensing in a single plane. In
particular, the magnifications between a `U'-shaped caustic crossing can be
close to unity, rather than having a minimum magnification of 3 as in the
single plane binary lensing. There is only a small probability
three-dimensional microlensing events will be seen in microlensing toward the
Galactic centre. It is more likely they will be first seen in cosmological
microlensing.


title: Simplicial complexes Alexander dual to boundaries of polytopes

abstract:
  In the paper we treat Gale diagrams in a combinatorial way. The
interpretation allows to describe simplicial complexes which are Alexander dual
to boundaries of simplicial polytopes and, more generally, to nerve-complexes
of general polytopes. This technique and recent results of N.Yu.Erokhovets are
combined to prove the following: Buchstaber invariant $s(P)$ of a convex
polytope equals 1 if and only if $P$ is a pyramid. In general, we describe a
procedure to construct polytopes with $s_R(P)>k$. The construction has purely
combinatorial consequences. We also apply Gale duality to the study of bigraded
Betti numbers and f-vectors of polytopes.


title:
A practical approach to ontology-enabled control systems for
  astronomical instrumentation

abstract:
  Even though modern service-oriented and data-oriented architectures promise
to deliver loosely coupled control systems, they are inherently brittle as they
commonly depend on a priori agreed interfaces and data models. At the same
time, the Semantic Web and a whole set of accompanying standards and tools are
emerging, advocating ontologies as the basis for knowledge exchange. In this
paper we aim to identify a number of key ideas from the myriad of
knowledge-based practices that can readily be implemented by control systems
today. We demonstrate with a practical example (a three-channel imager for the
Mercator Telescope) how ontologies developed in the Web Ontology Language (OWL)
can serve as a meta-model for our instrument, covering as many engineering
aspects of the project as needed. We show how a concrete system model can be
built on top of this meta-model via a set of Domain Specific Languages (DSLs),
supporting both formal verification and the generation of software and
documentation artifacts. Finally we reason how the available semantics can be
exposed at run-time by adding a "semantic layer" that can be browsed, queried,
monitored etc. by any OPC UA-enabled client.


title: O-minimal Hauptvermutung for polyhedra II

abstract:
  Hilbert initiated the standpoint in foundations of mathematics. From this
standpoint, we allow only a finite number of repetitions of elementary
operations when we construct objects and morphisms. When we start from a subset
of a Euclidean space. Then we assume that any element of the line has only a
finite number of connected components. We call the set tame if the assumption
is satisfied, and define a tame morphism in the same way.
  In this paper we will show that a tame topological manifold is carried by a
tame homeomorphism to the interior of a compact piecewise linear manifolds
possibly with boundary and such a piecewise linear manifold possibly with
boundary is unique up to piecewise linear homeomorphisms in the sense that if
two manifolds are such PL manifolds possibly with boundary then they are the
same as piecewise linear manifolds. We modify this to Theorem 2 so that
argument of model theory works, and we prove it. We also consider the
differentiable case.


title:
Pseudogap phenomenon and effects of population imbalance in the normal
  state of a unitary Fermi gas

abstract:
  We investigate strong-coupling corrections to single-particle excitations in
the normal state of a spin-polarized unitary Fermi gas. Within the framework of
an extended T-matrix approximation, we calculate the single-particle density of
states, as well as the single-particle spectral weight, to show that the
so-called pseudogap phenomenon gradually disappears with increasing the
magnitude of an effective magnetic field. In the highly spin-polarized regime,
the calculated spin-polarization rate as a function of the effective magnetic
field agrees well with the recent experiment on a 6Li Fermi gas. Although this
experiment has been considered to be incompatible with the existence of the
pseudogap in an unpolarized Fermi gas, our result clarifies that the observed
spin-polarization rate in the highly spin-polarized regime and the pseudogap in
the unpolarized limit can be explained in a consistent manner, when one
correctly includes effects of population imbalance on single-particle
excitations. Since it is a crucial issue to clarify whether the pseudogap
exists or not in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein
condensation) crossover regime of an ultracold Fermi gas, our results would be
useful for the understanding of this strongly interacting fermion system.


title: Resonant effects in a SQUID qubit subjected to non adiabatic changes

abstract:
  By quickly modifying the shape of the effective potential of a double SQUID
flux qubit from a single-well to a double-well condition, we experimentally
observe an anomalous behavior, namely an alternance of resonance peaks, in the
probability to find the qubit in a given flux state. The occurrence of
Landau-Zener transitions as well as resonant tunneling between degenerate
levels in the two wells may be invoked to partially justify the experimental
results. A quantum simulation of the time evolution of the system indeed
suggests that the observed anomalous behavior can be imputable to quantum
coherence effects. The interplay among all these mechanisms has a practical
implication for quantum computing purposes, giving a direct measurement of the
limits on the sweeping rates possible for a correct manipulation of the qubit
state by means of fast flux pulses, avoiding transitions to non-computational
states.


abstract:
  The study of quarkonia, bound states of heavy (charm or bottom)
quark-antiquark pairs such as the J/psi or the Upsilon?, provides insight into
the earliest and hottest stages of high-energy nucleus-nucleus collisions where
the formation of a Quark-Gluon Plasma is expected. High-precision data from
proton-proton collisions represent an essential baseline for the measurement of
nuclear modifications in nucleus-nucleus collisions and serve also as a crucial
test for models of quarkonium hadroproduction. Another fundamental tool to
understand the quarkonium production in nucleus-nucleus collisions is the the
study of proton-nucleus interactions, which allows one to investigate cold
nuclear matter effects, such as parton shadowing or gluon saturation. The ALICE
detector provides excellent capabilities to study quarkonium production at the
Large Hadron Collider at both central and forward rapidity. An overview on
ALICE results on quarkonium production in pp, p-Pb and Pb-Pb collisions is
presented. Results are compared to theoretical model predictions.


title: Brooks' theorem on powers of graphs

abstract:
  We prove that for $k\geq 3$, the bound given by Brooks' theorem on the
chromatic number of $k$-th powers of graphs of maximum degree $\Delta \geq 3$
can be lowered by 1, even in the case of online list coloring.


title:
Disentangling different types of El Ni\~no episodes by evolving climate
  network analysis

abstract:
  Complex network theory provides a powerful toolbox for studying the structure
of statistical interrelationships between multiple time series in various
scientific disciplines. In this work, we apply the recently proposed climate
network approach for characterizing the evolving correlation structure of the
Earth's climate system based on reanalysis data of surface air temperatures. We
provide a detailed study on the temporal variability of several global climate
network characteristics. Based on a simple conceptual view on red climate
networks (i.e., networks with a comparably low number of edges), we give a
thorough interpretation of our evolving climate network characteristics, which
allows a functional discrimination between recently recognized different types
of El Ni\~no episodes. Our analysis provides deep insights into the Earth's
climate system, particularly its global response to strong volcanic eruptions
and large-scale impacts of different phases of the El Ni\~no Southern
Oscillation (ENSO).


title: A Navier Stokes Phase Field Crystal Model for Colloidal Suspensions

abstract:
  We develop a fully continuous model for colloidal suspensions with
hydrodynamic interactions. The Navier Stokes Phase Field Crystal (NS-PFC) model
combines ideas of dynamic density functional theory with particulate flow
approaches and is derived in detail and related to other dynamic density
functional theory approaches with hydrodynamic interactions. The derived system
is numerically solved using adaptive finite elements and used to analyse
colloidal crystallization in flowing environments demonstrating a strong
coupling in both directions between the crystal shape and the flow field. We
further validate the model against other computational approaches for
particulate flow systems for various colloidal sedimentation problems.


title: Finite $p$-groups with a minimal non-abelian subgroup of index $p$ (III)

abstract:
  In this paper, we finished the classification of three-generator finite
$p$-groups $G$ such that $\Phi(G)\le Z(G)$. This paper is a part of
classification of finite $p$-groups with a minimal non-abelian subgroup of
index $p$, and partly solved a problem proposed by Y. Berkovich.


title:
Using CamiTK for rapid prototyping of interactive Computer Assisted
  Medical Intervention applications

abstract:
  Computer Assisted Medical Intervention (CAMI hereafter) is a complex
multi-disciplinary field. CAMI research requires the collaboration of experts
in several fields as diverse as medicine, computer science, mathematics,
instrumentation, signal processing, mechanics, modeling, automatics, optics,
etc.


title:
Ergodic BSDEs and related PDEs with Neumann boundary conditions under
  weak dissipative assumptions

abstract:
  We study a class of ergodic BSDEs related to PDEs with Neumann boundary
conditions. The randomness of the drift is given by a forward process under
weakly dissipative assumptions with an invertible and bounded diffusion matrix.
Furthermore, this forward process is reflected in a convex subset of $\R^d$ not
necessary bounded. We study the link of such EBSDEs with PDEs and we apply our
results to an ergodic optimal control problem.


title:
A new measurement of the $K^\pm\to\pi^\pm\gamma\gamma$ decay at the
  NA48/2 experiment

abstract:
  The NA48/2 experiment at CERN collected two data samples with minimum bias
trigger conditions in 2003 and 2004. A measurement of the rate and dynamic
properties of the rare decay $K^\pm\to\pi^\pm\gamma\gamma$ from these data sets
based on 149 decay candidates with an estimated background of $15.5\pm0.7$
events is reported. The model-independent branching ratio in the kinematic
range $z=(m_{\gamma\gamma}/m_K)^2>0.2$ is measured to be ${\cal B}_{\rm
MI}(z>0.2) = (0.877 \pm 0.089) \times 10^{-6}$, and the branching ratio in the
full kinematic range assuming a particular Chiral Perturbation Theory
description to be ${\cal B}(K_{\pi\gamma\gamma}) = (0.910 \pm 0.075) \times
10^{-6}$.


title:
Possible experimental signature of octupole correlations in the 0$^+_2$
  states of the actinides

abstract:
  $J^{\pi}$= 0$^+$ states have been investigated in the actinide nucleus
${}^{240}$Pu up to an excitation energy of 3 MeV with a high-resolution (p,t)
experiment at $E_{p}$= 24 MeV. To test the recently proposed $J^{\pi}$= 0$^+_2$
double-octupole structure, the phenomenological approach of the
spdf-interacting boson model has been chosen. In addition, the total 0$^+$
strength distribution and the $0^+$ strength fragmentation have been compared
to the model predictions as well as to the previously studied (p,t) reactions
in the actinides. The results suggest that the structure of the 0$^+_2$ states
in the actinides might be more complex than the usually discussed pairing
isomers. Instead, the octupole degree of freedom might contribute
significantly. The signature of two close-lying 0$^+$ states below the
2-quasiparticle energy is presented as a possible manifestation of strong
octupole correlations in the structure of the 0$^+_2$ states in the actinides.


title: Topological Phase Transition in the Extended Cluster Compass Ladder

abstract:
  We have studied the exact solution of the extended cluster compass ladder,
which is equivalent to extended quantum compass model with cluster interaction
between next-nearest-neighbor spins, by using the Jordan-Wigner transformation.
We show that this model is always gapfull except at the critical surfaces where
the energy gap disappears. We obtain the analytic expressions of all critical
couplings which drive quantum phase transitions. This model shows a rich phase
diagram which includes spin-flop, strip antiferromagnetic and topological
ordered on the legs, in addition to the phase with antiparallel ordering of
spin y component on the rungs. We study also the universality and scaling
properties of the three point correlation functions derivatives in different
regions to confirm the results obtained using the energy gap analysis. On the
other hand, we have replaced the cluster interaction with usual form and using
the Lanczos method a numerical experiment is done. Analyzing the numerical
results, we show that the effect of the cluster interaction between
next-nearest-neighbor spins is completely different from the usual form.


title: Asymptotic Behaviors of Selected Unitary 9j Coefficients

abstract:
  We consider the behaviors of selected unitary 9 coefficients in the large j
limit.


title: Finite $p$-groups with a minimal non-abelian subgroup of index $p$ (IV)

abstract:
  In this paper, we completely classify the finite $p$-groups $G$ such that
$\Phi(G')G_3\le C_p^2$, $\Phi(G')G_3\le Z(G)$ and $G/\Phi(G')G_3$ is minimal
non-abelian. This paper is a part of the classification of finite $p$-groups
with a minimal non-abelian subgroup of index $p$. Together with other four
papers, we solve a problem proposed by Y. Berkovich.


title: Barnette's Conjecture

abstract:
  This report provides an overview of theorems and statements related to a
conjecture stated by D.W. Barnette in 1969 (which is an open problem in graph
theory): Every cubic, bipartite, polyhedral graph contains a Hamilton cycle.


title: Coherence properties of Kerr frequency combs

abstract:
  We use numerical simulations based on an extended Lugiato-Lefever equation
(LLE) to investigate the stability properties of Kerr frequency combs generated
in microresonators. In particular, we show that an ensemble average calculated
over sequences of output fields separated by a fixed number of resonator
roundtrips allows the coherence of Kerr combs to be quantified in terms of the
complex-degree of first-order coherence. We identify different regimes of comb
coherence, linked to the solutions of the LLE. Our approach provides a
practical and unambiguous way of assessing the stability of Kerr combs that is
directly connected to an accessible experimental quantity.


title:
On uniqueness of symmetric Navier-Stokes flows around a body in the
  plane

abstract:
  We investigate the uniqueness of symmetric weak solutions to the stationary
Navier-Stokes equation in a two-dimensional exterior domain $\Omega$. It is
known that, under suitable symmetry condition on the domain and the data, the
problem admits at least one symmetric weak solution tending to zero at
infinity. Given two symmetric weak solutions $u$ and $v$, we show that if $u$
satisfies the energy inequality $\| \nabla u \|_{L^2 (\Omega)}^2 \le (f,u)$ and
$\sup_{x \in \Omega} (|x|+1)|v(x)|$ is sufficiently small, then $u=v$. The
proof relies upon a density property for the solenoidal vector field and the
Hardy inequality for symmetric functions.


title:
On complex oscillation theory, quasi-exact solvability and Fredholm
  Integral Equations

abstract:
  Biconfluent Heun equation (BHE) is a confluent case of the general Heun
equation which has one more regular singular points than the Gauss
hypergeometric equation on the Riemann sphere $\hat{\mathbb{C}}$. Motivated by
a Nevanlinna theory (complex oscillation theory) approach, we have established
a theory of \textit{periodic} BHE (PBHE) in parallel with the Lam\'e equation
verses the Heun equation, and the Mathieu equation verses the confluent Heun
equation. We have established condition that lead to explicit construction of
eigen-solutions of PBHE, and their single and double orthogonality, and a
related first-order Fredholm-type integral equation for which the corresponding
eigen-solutions must satisfy. We have also established a Bessel polynomials
analogue at the BHE level which is based on the observation that both the
Bessel equation and the BHE have a regular singular point at the origin and an
irregular singular point at infinity on the Riemann sphere $\hat{\mathbb{C}}$,
and that the former equation has orthogonal polynomial solutions with respect
to a complex weight. Finally, we relate our results to an equation considered
by Turbiner, Bender and Dunne, etc concerning a quasi-exact solvable
Schr\"odinger equation generated by first order operators such that the second
order operators possess a finite-dimensional invariant subspace in a Lie
algebra of $SL_2(\mathbb{C})$


title: Dynamical Control in a Quasi-periodically Modulated Optical Lattice

abstract:
  We investigate quantum tunneling phenomena for an optical lattice subjected
to a bichromatic ac force. We show that incommensurability of the frequencies
leads to super Bloch oscillation. We propose directed super Bloch oscillation
for the quasi periodically driven optical lattice. We study the dynamical
localization and photon assisted tunneling for a periodical and
quasi-periodical ac force.


title: The Classification of Finite Metahamiltonian $p$-Groups

abstract:
  A group is called metahamiltonian if all non-abelian subgroups of it are
normal. This concept is a natural generation of Hamiltonian groups. In this
paper, a complete classification of finite metahamiltonian $p$-groups is given.


title:
Goodness-of-Fit Tests for Pareto Distribution Based on a
  Characterization and their Asymptotics

abstract:
  In this paper we present a new characterization of Pareto distribution and
consider goodness of fit tests based on it. We provide an integral and
Kolmogorov- Smirnov type statistics based on U-statistics and we calculate
Bahadur efficiency for various alternatives. We find locally optimal
alternatives for those tests. For small sample sizes we compare the power of
those tests with some common goodness of fit tests.


title: Fluid fragmentation from hospital toilets

abstract:
  Hospital-acquired infections represent significant health and financial
burdens to society. Clostridium difficile (C. difficile) is a particularly
challenging bacteria with the potential to cause severe diarrhea and death. One
mode of transmission for C. difficile, as well as other pathogens, which has
received little attention is the potential air contamination by
pathogen-bearing droplets emanating from toilets. In the fluid dynamics video
submitted to the APS DFD Gallery of Fluid Motion 2013, we present flow
visualizations via high-speed recordings showing the capture of the product of
the fluid fragmentation generated by hospital toilet high-pressure flushes.
Important quantities of both large and small droplets are observed. We
illustrate how high-pressure flushes and cleaning products currently used in
hospital toilets result in aggravating, rather than alleviating, the suspension
and recirculation of tenacious airborne pathogen-bearing droplets.


title:
The inductive Alperin-McKay and blockwise Alperin weight conditions for
  blocks with cyclic defect groups

abstract:
  We verify the inductive blockwise Alperin weight (BAW) and the inductive
Alperin-McKay (AM) conditions introduced by the second author for blocks of
finite quasisimple groups with cyclic defect groups. Furthermore we establish a
criterion that describes conditions under which the inductive AM condition for
blocks with abelian defect groups implies the inductive BAW condition for those
blocks.


title:
Twisted mass lattice computation of charmed mesons with focus on
  $D^{\ast \ast}$

abstract:
  We present results of a 2+1+1 flavor twisted mass lattice QCD computation of
the spectrum of $D$ mesons and $D_s$ mesons and of charmonium. Particular focus
is put on the positive parity $D$ states (so-called $D^{\ast \ast}$ mesons)
with quantum numbers $J^P = 0^+$, $1^+$ and $2^+$. Besides computing their
masses we are also separating and classifying the two $J^P = 1^+$ states
according to the angular momentum/spin of their light degrees of freedom (light
quarks and gluons) $j =1/2, 3/2$.


title: Time-Dependent Modulation of Cosmic Rays in the Heliosphere

abstract:
  The time-dependent modulation of galactic cosmic rays in the heliosphere is
studied by computing intensities using a time-dependent modulation model. By
introducing recent theoretical advances in the transport coefficients in the
model, computed intensities are compared with Voyager 1, International
Monitoring Platform (IMP) 8, and Ulysses proton observations in search of
compatibility. The effect of different modulation parameters on computed
intensities is also illustrated. It is shown that this approach produces, on a
global scale, realistic cosmic-ray proton intensities along the Voyager 1
spacecraft trajectory and at Earth upto ~2004, whereafter the computed
intensities recovers much slower towards solar minimum than observed in the
inner heliosphere. A modified time dependence in the diffusion coefficients is
proposed to improve compatibility with the observations at Earth after ~2004.
This modified time dependence led to an improved compatibility between computed
intensities and the observations along the Voyager 1 trajectory and at Earth
even after ~2004. An interesting result is that the cosmic-ray modulation
during the present polarity cycle is not determined only by changes in the
drift coefficient and tilt angle of the wavy current sheet, but is also largely
dependent on changes in the diffusion coefficients.


title: Perfect Permutation Codes with the Kendall's $\tau$-Metric

abstract:
  The rank modulation scheme has been proposed for efficient writing and
storing data in non-volatile memory storage. Error-correction in the rank
modulation scheme is done by considering permutation codes. In this paper we
consider codes in the set of all permutations on $n$ elements, $S_n$, using the
Kendall's $\tau$-metric. We prove that there are no perfect
single-error-correcting codes in $S_n$, where $n>4$ is a prime or $4\leq n\leq
10$. We also prove that if such a code exists for $n$ which is not a prime then
the code should have some uniform structure. We define some variations of the
Kendall's $\tau$-metric and consider the related codes and specifically we
prove the existence of a perfect single-error-correcting code in $S_5$.
Finally, we examine the existence problem of diameter perfect codes in $S_n$
and obtain a new upper bound on the size of a code in $S_n$ with even minimum
Kendall's $\tau$-distance.


title:
Renormalization group-like proof of the universality of the Tutte
  polynomial for matroids

abstract:
  In this paper we give a new proof of the universality of the Tutte polynomial
for matroids. This proof uses appropriate characters of Hopf algebra of
matroids, algebra introduced by Schmitt (1994). We show that these Hopf algebra
characters are solutions of some differential equations which are of the same
type as the differential equations used to describe the renormalization group
flow in quantum field theory. This approach allows us to also prove, in a
different way, a matroid Tutte polynomial convolution formula published by
Kook, Reiner and Stanton (1999). This FPSAC contribution is an extended
abstract.


title: The star formation history of CALIFA galaxies: Radial structures

abstract:
  We study the radial structure of the stellar mass surface density ($\mu$) and
stellar population age as a function of the total stellar mass and morphology
for a sample of 107 galaxies from the CALIFA survey. We use the fossil record
to recover the star formation history (SFH) in spheroidal and disk dominated
galaxies with masses from 10$^9$ to 10$^{12}$ M$_\odot$. We derive the half
mass radius, and we find that galaxies are on average 15% more compact in mass
than in light. HMR/HLR decreases with increasing mass for disk galaxies, but is
almost constant in spheroidal galaxies. We find that the galaxy-averaged
stellar population age, stellar extinction, and $\mu$ are well represented by
their values at 1 HLR. Negative radial gradients of the stellar population ages
support an inside-out formation. The larger inner age gradients occur in the
most massive disk galaxies that have the most prominent bulges; shallower age
gradients are obtained in spheroids of similar mass. Disk and spheroidal
galaxies show negative $\mu$ gradients that steepen with stellar mass. In
spheroidal galaxies $\mu$ saturates at a critical value that is independent of
the galaxy mass. Thus, all the massive spheroidal galaxies have similar local
$\mu$ at the same radius (in HLR units). The SFH of the regions beyond 1 HLR
are well correlated with their local $\mu$, and follow the same relation as the
galaxy-averaged age and $\mu$; suggesting that local stellar mass surface
density preserves the SFH of disks. The SFH of bulges are, however, more
fundamentally related to the total stellar mass, since the radial structure of
the stellar age changes with galaxy mass even though all the spheroid dominated
galaxies have similar radial structure in $\mu$. Thus, galaxy mass is a more
fundamental property in spheroidal systems while the local stellar mass surface
density is more important in disks.


title: Universal features in the energetics of symmetry breaking

abstract:
  A symmetry breaking (SB) involves an abrupt change in the set of microstates
that a system can explore. This change has unavoidable thermodynamic
implications. According to Boltzmann's microscopic interpretation of entropy, a
shrinkage of the set of compatible states implies a decrease of entropy, which
eventually needs to be compensated by dissipation of heat and consequently
requires work. Examples are the compression of a gas and the erasure of
information. On the other hand, in a spontaneous SB, the available phase space
volume changes without the need for work, yielding an apparent decrease of
entropy. Here we show that this decrease of entropy is a key ingredient in the
Szilard engine and Landauer's principle and report on a direct measurement of
the entropy change along SB transitions in a Brownian particle. The SB is
induced by a bistable potential created with two optical traps. The experiment
confirms theoretical results based on fluctuation theorems, allows us to
reproduce the Szilard engine extracting energy from a single thermal bath, and
shows that the signature of a SB in the energetics is measurable, providing new
methods to detect, for example, the coexistence of metastable states in
macromolecules.


title: Canonical Borel equivalence relations on $ \mathbb{R}^n$

abstract:
  In this paper we complete the attempt of H. Lefmann to show that Borel
equivalence relations on the $n$-element subsets of $2^{\omega}$, that respect
an order type, have a finite Ramsey basis.


title: Rewards and the evolution of cooperation in public good games

abstract:
  Properly coordinating cooperation is relevant for resolving public good
problems such as clean energy and environmental protection. However, little is
known about how individuals can coordinate themselves for a certain level of
cooperation in large populations of strangers. In a typical situation, a
consensus-building process hardly succeeds due to lack of face and standing.
The evolution of cooperation in this type of situation is studied using
threshold public good games in which cooperation prevails when it is initially
sufficient, or otherwise, it perishes. While punishment is a powerful tool to
shape human behaviours, institutional punishment is often too costly to start
with only a few contributors, which is another coordination problem. Here we
show that whatever the initial conditions, reward funds based on voluntary
contribution can evolve. The voluntary reward paves the way for effectively
overcoming the coordination problem and efficiently transforms freeloaders to
cooperators with a perceived small risk of collective failure.


title:
On possibility of realization NEUTRINO-4 experiment on search for
  oscillations of the reactor antineutrino into a sterile state

abstract:
  One has investigated possibility of performing NEUTRINO-4 experiment on
search for reactor neutrino oscillations into a sterile state at research
reactors. The simulated experiment has been conducted at 16 MW reactor WWR-M in
PNPI with the purpose of implementing a full scale experiment with the help of
100 MW reactor SM-3 in RIAR. Background conditions for making such an
experiment have been examined at both reactors. The conclusion has been made on
possible implementation of a full scale experiment NEUTRINO-4 at the reactor
SM-3 in RIAR.


title:
Time-dependent cosmic ray modulation in the outer heliosphere:
  Signatures of a heliospheric asymmetry and model predictions along Voyager 1
  and 2 trajectories

abstract:
  A two-dimensional, time-dependent numerical model is used to calculate the
modulation of cosmic rays in the heliosphere. Computations are compared to
spacecraft observations in the inner and outer heliosphere. It is shown that
the model produces cosmic ray proton intensities compatible to different
spacecraft observations on a global scale, at Earth and along both Voyager
spacecraft trajectories. The study reveals that when the same modulation
parameters, which resulted in compatible intensities along Voyager 1, were
assumed along the Voyager 2 trajectory, the model failed to reproduce the
observations. The study also found that any change in diffusion parameters
alone could not reproduce the cosmic ray observations along Voyager 2 so that
changes to the heliospheric geometry were necessary i.e the computed
intensities along both Voyager trajectories suggest that the heliosphere is
asymmetric. Furthermore, $E >$ 70 MeV and 133-242 MeV proton intensities along
Voyager 1 and 2 trajectories are predicted from end of 2012 onwards. It is
shown that the computed intensities along Voyager 1 increase with an almost
constant rate up to the heliopause. However, the model shows that Voyager 2 is
still under the influence of temporal solar activity changes because of its
relatively large distance to the heliopause. Along the Voyager 2 trajectory,
the intensities remained generally constant for some time and should soon start
to increase steadily.


title:
On the uniform convergence of empirical norms and inner products, with
  application to causal inference

abstract:
  Uniform convergence of empirical norms - empirical measures of squared
functions - is a topic which has received considerable attention in the
literature on empirical processes. The results are relevant as empirical norms
occur due to symmetrization. They also play a prominent role in statistical
applications. The contraction inequality has been a main tool but recently
other approaches have shown to lead to better results in important cases. We
present an overview including the linear (anisotropic) case, and give new
results for inner products of functions. Our main application will be the
estimation of the parental structure in a directed acyclic graph. As
intermediate result we establish convergence of the least squares estimator
when the model is wrong.


title: Fast Bayesian parameter estimation for stochastic logistic growth models

abstract:
  The transition density of a stochastic, logistic population growth model with
multiplicative intrinsic noise is analytically intractable. Inferring model
parameter values by fitting such stochastic differential equation (SDE) models
to data therefore requires relatively slow numerical simulation. Where such
simulation is prohibitively slow, an alternative is to use model approximations
which do have an analytically tractable transition density, enabling fast
inference. We introduce two such approximations, with either multiplicative or
additive intrinsic noise, each derived from the linear noise approximation of
the logistic growth SDE. After Bayesian inference we find that our fast LNA
models, using Kalman filter recursion for computation of marginal likelihoods,
give similar posterior distributions to slow arbitrarily exact models. We also
demonstrate that simulations from our LNA models better describe the
characteristics of the stochastic logistic growth models than a related
approach. Finally, we demonstrate that our LNA model with additive intrinsic
noise and measurement error best describes an example set of longitudinal
observations of microbial population size taken from a typical, genome-wide
screening experiment.


title: Systolizing buildings

abstract:
  We introduce a construction turning some Coxeter and Davis realizations of
buildings into systolic complexes. Consequently groups acting geometrically on
buildings of triangle types distinct from $(2,4,4)$, $(2,4,5)$, $(2,5,5)$, and
various rank $4$ types are systolic.


title: Origin of W UMa-type contact binaries - age and orbital evolution

abstract:
  Recently, our understanding of the origin of W UMa-type contact binaries has
become clearer. Initial masses of their components were successfully estimated
by Y{\i}ld{\i}z and Do\u{g}an using a new method mainly based on observational
properties of overluminous secondary components. In this paper, we continue to
discuss the results and make computations for age and orbital evolution of
these binaries. It is shown that the secondary mass, according to its
luminosity, also successfully predicts the observed radius. While the current
mass of the primary component is determined by initial masses, the current
secondary mass is also a function of initial angular momentum. We develop
methods to compute the age of A- and W-subtype W UMa-type contact binaries {in
terms of} initial masses and mass according to the luminosity of the
secondaries. Comparisons of our results with the mean ages from kinematic
properties of these binaries and data pertaining to contact binaries in open
and globular clusters, have increased our confidence on this method. The mean
ages of both A- and W-subtype contact binaries are found as 4.4 and 4.6 Gyr,
respectively. From kinematic studies, these ages are given as 4.5 and 4.4 Gyr,
respectively. We also compute orbital properties of A-subtype contact binaries
at the time of the first overflow. Initial angular momentum of these binaries
is computed by comparing them with the well-known detached binaries. The
angular momentum loss rate derived in the present study for the detached phase
is in very good agreement with the semi-empirical rates available in the
literature. In addition to the limitations on the initial masses of W UMa-type
contact binaries, it is shown that the initial period of these binaries is less
than about 4.45 d.


title: Power laws and Self-Organized Criticality in Theory and Nature

abstract:
  Power laws and distributions with heavy tails are common features of many
experimentally studied complex systems, like the distribution of the sizes of
earthquakes and solar flares, or the duration of neuronal avalanches in the
brain. Previously, researchers surmised that a single general concept may act
as a unifying underlying generative mechanism, with the theory of self
organized criticality being a weighty contender.
  Consequently, a substantial amount of effort has gone into developing new and
extended models and, hitherto, three classes of models have emerged. The first
line of models is based on a separation between the time scales of drive and
dissipation, and includes the original sandpile model and its extensions, like
the dissipative earthquake model. Within this approach the steady state is
close to criticality in terms of an absorbing phase transition. The second line
of models is based on external drives and internal dynamics competing on
similar time scales and includes the coherent noise model, which has a
non-critical steady state characterized by heavy-tailed distributions. The
third line of models proposes a non-critical self-organizing state, being
guided by an optimization principle, such as the concept of highly optimized
tolerance.
  We present a comparative overview regarding distinct modeling approaches
together with a discussion of their potential relevance as underlying
generative models for real-world phenomena. The complexity of physical and
biological scaling phenomena has been found to transcend the explanatory power
of individual paradigmal concepts. The interaction between theoretical
development and experimental observations has been very fruitful, leading to a
series of novel concepts and insights.


title: First experimental research of low energy proton radiography

abstract:
  Proton radiography is a new scatheless diagnostic tool, and which provides a
potential development direction for advanced hydrotesting. Recently a low
energy proton radiography system has been developed at CAEP. This system has
been designed to use 11MeV proton beam to radiograph thin static objects. This
system consists of a proton cyclotron coupled to an imaging beamline. The
design features and commissioning results of this radiography system are
presented.


title:
NMR study of the Superconducting gap variation near the Mott transition
  in Cs$_{3}$C$_{60}$

abstract:
  Former extensive studies of superconductivity in the \textit{A}$_{3}$C$_{60}$
compounds, where \textit{A} is an alkali, have led to consider that Bardeen
Cooper Schrieffer (BCS) electron-phonon pairing prevails in those compounds,
though the incidence of electronic Coulomb repulsion has been highly debated.
The discovery of two isomeric fulleride compounds Cs$_{3}$C$_{60}$ which
exhibit a transition with pressure from a Mott insulator (MI) to a
superconducting (SC) state clearly re-opens that question. Using pressure ($p$)
as a single control parameter of the C$_{60}$ balls lattice spacing, one can
now study the progressive evolution of the SC properties when the electronic
correlations are increased towards the critical pressure $p_{c}$ of the Mott
transition. We have used $^{13}$C and $^{133}$Cs NMR measurements on the cubic
phase A15-Cs$_{3}$C$_{60}$ just above $p_{c}=5.0(3)$ kbar, where the SC
transition temperature $T_{c}$ displays a dome shape with decreasing cell
volume. From the $T$ dependence below $T_{c}$ of the nuclear spin lattice
relaxation rate $(T_{1})^{-1}$ we determine the electronic excitations in the
SC state, that is $2\Delta$, the SC gap value. We find that $2\Delta $
increases with decreasing $p$ towards $p_{c}$, where $T_{c}$ decreases on the
SC dome, so that $2\Delta /k_{B}T_{c}$ increases regularly upon approaching the
Mott transition. These results bring clear evidence that the increasing
correlations near the Mott transition are not significantly detrimental to SC.
They rather suggest that repulsive electron interactions might even reinforce
elecron-phonon SC, being then partly responsible for the large $T_{c}$ values,
as proposed by theoretical models taking the electronic correlations as a key
ingredient.


title:
22 GHz Water Maser Search in 37 Nearby Galaxies - Four New Water
  Megamasers in Seyfert 2 and OH Maser/Absorber Galaxies

abstract:
  We report four new 22 GHz water masers found in a Green Bank Telescope search
toward 37 nearby objects. Our goal was to find new maser galaxies, AGN
disk-masers, and objects where both hydroxyl and water maser species coexist.
We observed 37 sources within 250 Mpc that were selected by high X-ray
luminosity (L_X > 10^40 W) and high absorbing column density (N_H ~ 10^22
cm^-2). Sources also included dual or triple AGN and interacting systems. We
further included objects detected in hydroxyl (OH). The selection consisted of
16 new sources, 13 previous non-detections to follow up with a factor ten
higher sensitivity, 10 OH masers and one deep OH absorber, of which 37 were
observed. Water megamasers were detected towards the Sy 2 galaxy 2MFGC 13581 (a
disk-maser), towards the 6 GHz OH absorber NGC 4261 (3C 270 with a twin-jet and
dusty torus; broad water maser emission), and towards the two 1.6 GHz OH maser
sources IRAS 17526+3253 and IRAS 20550+1656 (possible star formation water
masers). We set upper limits on 33 non-detections. The search increased the
number of known "dual-species" objects containing both OH and H2O masers to
eight. The detection rate was 25 % in OH galaxies and 11 % overall. Combined
with other searches, a total of 95 objects have now been searched for both OH
and H2O masers. We found the overall dual-species detection rate (8 in 95) to
be of the order of the joint probability of both species independently
occurring in the same object (1 % lower bound). However, this needs to be
verified by a more detailed analysis of selection criteria. Lastly, we see a
lack of H2O kilomasers in OH megamaser objects already noted by Tarchi et al.
(2011). This may be due to sensitivity bias rather than astrophysical reasons.


title: Sensing viruses by mechanical tension of DNA in responsive hydrogels

abstract:
  The rapid worldwide spread of severe viral infections, often involving novel
modifications of viruses, poses major challenges to our health care systems.
This means that tools that can efficiently and specifically diagnose viruses
are much needed. To be relevant for a broad application in local health care
centers, such tools should be relatively cheap and easy to use. Here we discuss
the biophysical potential for the macroscopic detection of viruses based on the
induction of a mechanical stress in a bundle of pre-stretched DNA molecules
upon binding of viruses to the DNA. We show that the affinity of the DNA to the
charged virus surface induces a local melting of the double-helix into two
single-stranded DNA. This process effects a mechanical stress along the DNA
chains leading to an overall contraction of the DNA. Our results suggest that
when such DNA bundles are incorporated in a supporting matrix such as a
responsive hydrogel, the presence of viruses may indeed lead to a significant,
macroscopic mechanical deformation of the matrix. We discuss the biophysical
basis for this effect and characterize the physical properties of the
associated DNA melting transition. In particular, we reveal several scaling
relations between the relevant physical parameters of the system. We promote
this DNA-based assay for efficient and specific virus screening.


title:
Implications of the ABC Resonance Structure on Elastic Neutron-Proton
  Scattering

abstract:
  In recent WASA-at-COSY measurements of the basic double-pionic fusion
reactions $pn \to d\pi^0\pi^0$ and $pn \to d\pi^+\pi^-$ a narrow resonance
structure with $I(J^P) = 0(3^+)$ in the total cross section has been found. If
this constitutes a s-channel resonance in the $pn$ system, then it should cause
distinctive consequences in $pn$ scattering. The magnitude of the decay width
into the $pn$ channel is estimated and the expected resonance effects in
integral and differential $pn$ scattering observables are presented. The
inclusion of the resonance improves the description of total cross section
data. For the analyzing power a characteristic energy dependence is predicted,
which should allow a crucial experimental check of the resonance hypothesis.


title: A Critical History of Renormalization

abstract:
  The history of renormalization is reviewed with a critical eye, starting with
Lorentz's theory of radiation damping, through perturbative QED with Dyson,
Gell-Mann & Low, and others, to Wilson's formulation and Polchinski's
functional equation, and applications to "triviality", and dark energy in
cosmology.


title: A Study of Truck Platooning Incentives Using a Congestion Game

abstract:
  We introduce an atomic congestion game with two types of agents, cars and
trucks, to model the traffic flow on a road over various time intervals of the
day. Cars maximize their utility by finding a trade-off between the time they
choose to use the road, the average velocity of the flow at that time, and the
dynamic congestion tax that they pay for using the road. In addition to these
terms, the trucks have an incentive for using the road at the same time as
their peers because they have platooning capabilities, which allow them to save
fuel. The dynamics and equilibria of this game-theoretic model for the
interaction between car traffic and truck platooning incentives are
investigated. We use traffic data from Stockholm to validate parts of the
modeling assumptions and extract reasonable parameters for the simulations. We
use joint strategy fictitious play and average strategy fictitious play to
learn a pure strategy Nash equilibrium of this game. We perform a comprehensive
simulation study to understand the influence of various factors, such as the
drivers' value of time and the percentage of the trucks that are equipped with
platooning devices, on the properties of the Nash equilibrium.


title: Multi-dimensional metric approximation by primitive points

abstract:
  We refine metrical statements in the style of the Khintchine-Groshev Theorem
by requiring certain coprimality constraints on the coordinates of the integer
solutions.


title: Agujeros negros cu\'anticos en la teor\'ia de cuerdas tipo-IIA

abstract:
  In the context of Type-IIA String Theory compactified to four dimensions on a
Calabi-Yau manifold (CY), we study the effect of considering perturbative and
non-perturbative corrections (in alpha prime) to the prepotential of the
resulting effective Supergravity theory on the space of black hole solutions.
Considering the large volume limit of the CY, in which the non-perturbative
corrections are exponentially suppressed, we define a new class of solutions
which turn out to be genuinely quantum, in the sense that not only their
classical limit is not well defined, but also the truncation under
consideration becomes inconsistent in such a limit. Next, we construct the
first non-extremal black hole solution with non-constant scalars in the
presence of perturbative corrections. Right after, restricting ourselves to the
case of self-mirror CY, we study the case in which the sub-dominant
contribution has a non-perturbative origin, obtaining the first family of
explicit supersymmetric solutions of this kind. Surprisingly enough, these
solutions turn out to involve multivalued functions, which opens the door for a
possible violation of the No-Hair conjecture. We discuss how this cannot be
accomplished in our String Theory set up, but how the possibility remains open
in the context of N=2, d=4 ungauged Supergravity.
  Fully in Spanish.


title:
On the construction of Hartle-Hawking-Israel states across a static
  bifurcate Killing horizon

abstract:
  We consider a linear scalar quantum field propagating in a space-time with a
static bifurcate Killing horizon and a wedge reflection. We prove the existence
of a Hadamard state which is pure, quasi-free, invariant under the Killing flow
and which restricts to a double KMS state at the inverse Hawking temperature on
the union of the exterior wedge regions. The existence of such a state was
first conjectured by Hartle and Hawking (1976) and Israel (1976) for stationary
black hole space times. Our result complements a uniqueness result of Kay and
Wald (1991), who considered a general bifurcate Killing horizon and proved that
a certain (large) subalgebra of the free field algebra admits at most one
Hadamard state which is invariant under the Killing flow. In the presence of a
wedge reflection this state reduces to a pure, quasi-free KMS state on the
smaller subalgebra associated to one of the exterior wedge regions. Our result
establishes the existence of such a state on the full algebra in the static
case. Our proof follows the arguments of Sewell (1982) and Jacobson (1994),
exploiting a Wick rotation in the Killing time coordinate to construct a
corresponding Euclidean theory. Because the Killing time coordinate is
ill-defined on the bifurcation surface we systematically replace it by a
Gaussian normal coordinate. A crucial part of our proof is to establish that
the Euclidean ground state satisfies the necessary analogs of analyticity and
reflection positivity with respect to this coordinate.


title: TCC, with History

abstract:
  Modern computer systems are awash in a sea of asynchronous events. There is
an increasing need for a declarative language that can permit business users to
specify complex event-processing rules. Such rules should be able to correlate
different event streams, detect absence of events (negative information),
permit aggregations over sliding windows, specify dependent sliding windows
etc. For instance it should be possible to precisely state a rule such as
"Every seventh trading session that DowJones has risen consecutively, and IBM's
stock is off 3% over its average in this period, evaluate IBM position",
"Declare the sensor as faulty if no reading has been received for 500 ms", etc.
Further, the language should be implementable efficiently in an event-driven
fashion.
  We propose the Timed (Default) Concurrent Constraint, TCC, programming
framework as a foundation for such complex event processing. While very rich,
the TCC framework "forgets" information from one instant to the next. We make
two extensions. First, we extend the TCC model to carry the store from previous
time instants as "past" information in the current time instant. This permits
rules to to be written with rich queries over the past. Second, we show that
many of the powerful properties of the agent language can be folded into the
query language by permitting agents and queries to be defined mutually
recursively, building on the testing interpretation of intuitionistic logic
described in RCC \cite{radha-fsttcs05}. We show that this permits queries to
move "back and forth" in the past, e.g.{} "Order a review if the last time that
IBM stock price dropped by 10% in a day, there was more than 20% increase in
trading volume for Oracle the following day."
  We provide a formal semantics for TCC + Histories and establish some basic
properties.


title: Directed Cycle Double Cover Conjecture: Fork Graphs

abstract:
  We explore the well-known Jaeger's directed cycle double cover conjecture
which is equivalent to the assertion that every cubic bridgeless graph has an
embedding on a closed orientable surface with no dual loop. We associate each
cubic graph G with a novel object H that we call a "hexagon graph"; perfect
matchings of H describe all embeddings of G on closed orientable surfaces. The
study of hexagon graphs leads us to define a new class of graphs that we call
"lean fork-graphs". Fork graphs are cubic bridgeless graphs obtained from a
triangle by sequentially connecting fork-type graphs and performing Y-Delta,
Delta-Y transformations; lean fork-graphs are fork graphs fulfilling a
connectivity property. We prove that Jaeger's conjecture holds for the class of
lean fork-graphs. The class of lean fork-graphs is rich; namely, for each cubic
bridgeless graph G there is a lean fork-graph containing a subdivision of G as
an induced subgraph. Our results establish for the first time, to the best of
our knowledge, the validity of Jaeger's conjecture in a broad inductively
defined class of graphs.


title: Frequency Effects on Predictability of Stock Returns

abstract:
  We propose that predictability is a prerequisite for profitability on
financial markets. We look at ways to measure predictability of price changes
using information theoretic approach and employ them on all historical data
available for NYSE 100 stocks. This allows us to determine whether frequency of
sampling price changes affects the predictability of those. We also relations
between price changes predictability and the deviation of the price formation
processes from iid as well as the stock's sector. We also briefly comment on
the complicated relationship between predictability of price changes and the
profitability of algorithmic trading.


title:
Piecewise Constant Sequential Importance Sampling for Fast Particle
  Filtering

abstract:
  Particle filters are key algorithms for object tracking under non-linear,
non-Gaussian dynamics. The high computational cost of particle filters,
however, hampers their applicability in cases where the likelihood model is
costly to evaluate, or where large numbers of particles are required to
represent the posterior. We introduce the approximate sequential importance
sampling/resampling (ASIR) algorithm, which aims at reducing the cost of
traditional particle filters by approximating the likelihood with a mixture of
uniform distributions over pre-defined cells or bins. The particles in each bin
are represented by a dummy particle at the center of mass of the original
particle distribution and with a state vector that is the average of the states
of all particles in the same bin. The likelihood is only evaluated for the
dummy particles, and the resulting weight is identically assigned to all
particles in the bin. We derive upper bounds on the approximation error of the
so-obtained piecewise constant function representation, and analyze how bin
size affects tracking accuracy and runtime. Further, we show numerically that
the ASIR approximation error converges to that of sequential importance
sampling/resampling (SIR) as the bin size is decreased. We present a set of
numerical experiments from the field of biological image processing and
tracking that demonstrate ASIR's capabilities. Overall, we consider ASIR a
promising candidate for simple, fast particle filtering in generic
applications.


title: Ship Detection and Segmentation using Image Correlation

abstract:
  There have been intensive research interests in ship detection and
segmentation due to high demands on a wide range of civil applications in the
last two decades. However, existing approaches, which are mainly based on
statistical properties of images, fail to detect smaller ships and boats.
Specifically, known techniques are not robust enough in view of inevitable
small geometric and photometric changes in images consisting of ships. In this
paper a novel approach for ship detection is proposed based on correlation of
maritime images. The idea comes from the observation that a fine pattern of the
sea surface changes considerably from time to time whereas the ship appearance
basically keeps unchanged. We want to examine whether the images have a common
unaltered part, a ship in this case. To this end, we developed a method -
Focused Correlation (FC) to achieve robustness to geometric distortions of the
image content. Various experiments have been conducted to evaluate the
effectiveness of the proposed approach.


title: Universalities of Reproducing Kernels Revisited

abstract:
  Kernel methods have been widely applied to machine learning and other
questions of approximating an unknown function from its finite sample data. To
ensure arbitrary accuracy of such approximation, various denseness conditions
are imposed on the selected kernel. This note contributes to the study of
universal, characteristic, and $C_0$-universal kernels. We first give simple
and direct description of the difference and relation among these three kinds
of universalities of kernels. We then focus on translation-invariant and
weighted polynomial kernels. A simple and shorter proof of the known
characterization of characteristic translation-invariant kernels will be
presented. The main purpose of the note is to give a delicate discussion on the
universalities of weighted polynomial kernels.


title: Stability of pairs

abstract:
  This is essentially an expository note based on S. Paul's works on the
stability of pairs. Its connection to K-stability will be also discussed.


title: Koornwinder polynomials and the XXZ spin chain

abstract:
  Nonsymmetric Koornwinder polynomials are multivariable extensions of
nonsymmetric Askey-Wilson polynomials. They naturally arise in the
representation theory of (double) affine Hecke algebras. In this paper we
discuss how nonsymmetric Koornwinder polynomials naturally arise in the theory
of the Heisenberg XXZ spin-$\frac{1}{2}$ chain with general reflecting boundary
conditions. A central role in this story is played by an explicit two-parameter
family of spin representations of the two-boundary Temperley-Lieb algebra.
These spin representations have three different appearances. Their original
definition relates them directly to the XXZ spin chain, in the form of
matchmaker representations they relate to Temperley-Lieb loop models in
statistical physics, while their realization as principal series
representations leads to the link with nonsymmetric Koornwinder polynomials.
The nonsymmetric difference Cherednik-Matsuo correspondence allows to construct
for special parameter values Laurent-polynomial solutions of the associated
reflection quantum KZ equations in terms of nonsymmetric Koornwinder
polynomials. We discuss these aspects in detail by revisiting and extending
work of De Gier, Kasatani, Nichols, Cherednik, the first author and many
others.


title:
Color-Magnitude Relations within Globular Cluster Systems of Giant
  Elliptical Galaxies: The Effects of Globular Cluster Mass Loss and the
  Stellar Initial Mass Function

abstract:
  Several recent studies have provided evidence for a `bottom-heavy' stellar
initial mass function (IMF) in massive elliptical galaxies. Here we investigate
the influence of the IMF shape on the recently discovered color-magnitude
relation (CMR) among globular clusters (GCs) in such galaxies. To this end we
use calculations of GC mass loss due to stellar and dynamical evolution to
evaluate (i) the shapes of stellar mass functions in GCs after 12 Gyr of
evolution as a function of current GC mass along with their effects on
integrated-light colors and mass-to-light ratios, and (ii) their impact on the
effects of GC self-enrichment using the 2009 `reference' model of Bailin &
Harris. As to the class of metal-poor GCs, we find the observed shape of the
CMR (often referred to as the `blue tilt') to be very well reproduced by Bailin
& Harris' reference self-enrichment model once 12 Gyr of GC mass loss is taken
into account. The influence of the IMF on this result is found to be
insignificant. However, we find that the observed CMR among the class of
metal-rich GCs (the `red tilt') can only be adequately reproduced if the IMF
was bottom-heavy (e.g., $-3.0 <~ \alpha <~ -2.3$ in $dN/dM \propto
M^{\alpha}$), which causes the stellar mass function at subsolar masses to
depend relatively strongly on GC mass. This constitutes additional evidence
that the metal-rich stellar populations in giant elliptical galaxies were
formed with a bottom-heavy IMF.


title:
Importance of non-parabolic band effects in the thermoelectric
  properties of semiconductors

abstract:
  We present an analysis of the thermoelectric properties of of $n$-type GeTe
and SnTe in relation to the lead chalcogenides PbTe and PbSe. We find that the
singly degenerate conduction bands of semiconducting GeTe and SnTe are highly
non-ellipsoidal, even very close to the band edges. This leads to isoenergy
surfaces with a strongly corrugated shape that is clearly evident at carrier
concentrations well below 0.005 $e$ per formula unit (7 - 9 $\times$
10$^{19}$cm$^{-3}$ depending on material) Analysis within Boltzmann theory
suggests that this corrugation may be favorable for the thermoelectric
transport. Our calculations also indicate that values of the power factor for
these two materials may well exceed those of PbTe and PbSe. As a result these
materials may exhibit $n$-type performance exceeding that of the lead
chalcogenides.


title: On conjugacy classes of the Klein simple group in Cremona group

abstract:
  We consider countably many three dimensional
$\mathtt{PSL}_2(\mathbb{F}_7)$-del Pezzo surface fibrations over
$\mathbb{P}^1$. Conjecturally they are all irrational except two families, one
of which is the product of a del Pezzo surface with $\mathbb{P}^1$. We show
that the other model is $\mathtt{PSL}_2(\mathbb{F}_7)$-equivariantly birational
to $\mathbb{P}^2\times\mathbb{P}^1$. Based on a result of Prokhorov, we show
that they are non-conjugate as subgroups of the Cremona group
$\mathtt{Cr}_3(\mathbb{C})$.


title: K-theory of crossed products of tiling C*-algebras by rotation groups

abstract:
  Let $\Omega$ be a tiling space and let $G$ be the maximal group of rotations
which fixes $\Omega$. Then the cohomology of $\Omega$ and $\Omega/G$ are both
invariants which give useful geometric information about the tilings in
$\Omega$. The noncommutative analog of the cohomology of $\Omega$ is the
K-theory of a C*-algebra associated to $\Omega$, and for translationally finite
tilings of dimension 2 or less the K-theory is isomorphic to the direct sum of
cohomology groups. In this paper we give a prescription for calculating the
noncommutative analog of the cohomology of $\Omega/G$, that is, the K-theory of
the crossed product of the tiling C*-algebra by $G$. We also provide a table
with some calculated K-groups for many common examples, including the Penrose
and pinwheel tilings.


title: Micro Pixel Chamber with resistive electrodes for spark reduction

abstract:
  The Micro Pixel Chamber (mu-PIC) using resistive electrodes has been
developed and tested. The surface cathodes are made from resistive material, by
which the electrical field is reduced when large current is flowed.
Two-dimensional readouts are achieved by anodes and pickup electrodes, on which
signals are induced. High gas gain (> 60000) was measured using 55Fe (5.9 keV)
source, and very intensive spark reduction was attained under fast neutron. The
spark rate of resistive mu-PIC was only 10^-4 times less than that of
conventional mu-PIC at the gain of 10^4. With these developments, a new MPGD
with no floating structure is achieved, with enough properties of both high
gain and good stability to detect MIP particles. In addition, mu-PIC can be
operated with no HV applied on anodes by using resistive cathodes. Neither AC
coupling capacitors nor HV pull up resisters are needed for any anode
electrode. Signal readout is drastically simplified by that configuration.


title: SymbolicData:SDEval - Benchmarking for Everyone

abstract:
  In this paper we will present SDeval, a software project that contains tools
for creating and running benchmarks with a focus on problems in computer
algebra. It is built on top of the Symbolic Data project, able to translate
problems in the database into executable code for various computer algebra
systems. The included tools are designed to be very flexible to use and to
extend, such that they can be utilized even in contexts of other communities.
With the presentation of SDEval, we will also address particularities of
benchmarking in the field of computer algebra. Furthermore, with SDEval, we
provide a feasible and automatizable way of reproducing benchmarks published in
current research works, which appears to be a difficult task in general due to
the customizability of the available programs. We will simultaneously present
the current developments in the Symbolic Data project.


title:
From evaluation to learning: Some aspects of designing a
  cyber-university

abstract:
  Research is described on a system for web-assisted education and how it is
used to deliver on-line drill questions, automatically suited to individual
students. The system can store and display all of the various pieces of
information used in a class-room (slides, examples, handouts, drill items) and
give individualized drills to participating students. The system is built on
the basic theme that it is for learning rather than evaluation.
  Experimental results shown here imply that both the item database and the
item allocation methods are important and examples are given on how these need
to be tuned for each course. Different item allocation methods are discussed
and a method is proposed for comparing several such schemes. It is shown that
students improve their knowledge while using the system. Classical statistical
models which do not include learning, but are designed for mere evaluation, are
therefore not applicable.
  A corollary of the openness and emphasis on learning is that the student is
permitted to continue requesting drill items until the system reports a grade
which is satisfactory to the student. An obvious resulting challenge is how
such a grade should be computed so as to reflect actual knowledge at the time
of computation, entice the student to continue and simultaneously be a clear
indication for the student. To name a few methods, a grade can in principle be
computed based on all available answers on a topic, on the last few answers or
on answers up to a given number of attempts, but all of these have obvious
problems.


title:
Hypothesis Testing on Invariant Subspaces of the Symmetric Group, Part I
  - Quantum Sanov's Theorem and Arbitrarily Varying Sources

abstract:
  We report a proof of the quantum Sanov Theorem by elementary application of
basic facts about representations of the symmetric group, together with a
complete characterization of the optimal error exponent in a situation where
the null hypothesis is given by an arbitrarily varying quantum source instead.
Our approach differs from previous ones in two points: First, it supports a
reasoning inspired by the method of types. Second, the measurement scheme we
propose to distinguish the two alternatives not only does that job
asymptotically perfect, but also yields additional information about the null
hypothesis. An example of that is given. The measurement is composed of
projections onto permutation-invariant subspaces, thus providing a direct link
between one of the most basic tasks in quantum information on the one hand side
and fundamental objects in representation theory on the other. We additionally
connect to representation theory by proving a relation between Kostka numbers
and quantum states, and to state estimation via a generalization of a
well-known spectral estimation theorem to non-i.i.d. sequences.

categories: quant-ph cs.IT math-ph math.IT math.MP math.RT


title: Non-rigid quartic 3-folds

abstract:
  Let $X\subset \mathbb{P}^4$ be a terminal factorial quartic $3$-fold. If $X$
is non-singular, $X$ is \emph{birationally rigid}, i.e. the classical MMP on
any terminal $\mathbb{Q}$-factorial projective variety $Z$ birational to $X$
always terminates with $X$. This no longer holds when $X$ is singular, but very
few examples of non-rigid factorial quartics are known. In this article, we
first bound the local analytic type of singularities that may occur on a
terminal factorial quartic hypersurface $X\subset \mathbb{P}^4$. A singular
point on such a hypersurface is either of type $cA_n$ ($n\geq 1$), or of type
$cD_m$ ($m\geq 4$), or of type $cE_6, cE_7$ or $cE_8$. We first show that if
$(P \in X)$ is of type $cA_n$, $n$ is at most $7$, and if $(P \in X)$ is of
type $cD_m$, $m$ is at most $8$. We then construct examples of non-rigid
factorial quartic hypersurfaces whose singular loci consist (a) of a single
point of type $cA_n$ for $2\leq n\leq 7$ (b) of a single point of type $cD_m$
for $m= 4$ or $5$ and (c) of a single point of type $cE_k$ for $k=6,7$ or $8$.


title:
Quantum error-correcting codes and 4-dimensional arithmetic hyperbolic
  manifolds

abstract:
  Using 4-dimensional arithmetic hyperbolic manifolds, we construct some new
homological quantum error correcting codes. They are LDPC codes with linear
rate and distance $n^\epsilon$. Their rate is evaluated via Euler
characteristic arguments and their distance using $\mathbb{Z}_2$-systolic
geometry. This construction answers a queston of Z\'emor, who asked whether
homological codes with such parameters could exist at all.


title:
Comment on "Tsallis power laws and finite baths with negative heat
  capacity" [Phys. Rev. E 88, 042126 (2013)]

abstract:
  In [Phys. Rev. E 88, 042126 (2013)] it is stated that Tsallis distributions
do not emerge from thermalization with a "bath" of finite, energy-independent,
heat capacity. We report evidence for the contrary.


title:
On the Optimal Scheduling in Pull-based Real-Time P2P Streaming Systems:
  Layered and Non-Layered Streaming

abstract:
  During the last decade, we witnessed a rapid growth in deployment of
pull-based P2P streaming applications. In these applications, each node selects
some other nodes as its neighbors and requests streaming data from them. This
scheme allows eliminating data redundancy and recovering from data loss, but it
pushes the complexity to the receiver node side. In this paper, we
theoretically study the scheduling problem in Pull-based P2P video streaming
and we model it as an assignment problem. Then, we propose AsSched, new
scheduling algorithm for layered streaming, in order to optimize the throughput
and the delivery ratio of the system. In second time, we derive an optimal
algorithm (NAsSched) for non layered streaming. The results of simulations show
that our algorithms significantly outperform classic scheduling strategies
especially in stern bandwidth constraints.


title: Avoiding Shared Clocks in Networks of Timed Automata

abstract:
  Networks of timed automata (NTA) are widely used to model distributed
real-time systems. Quite often in the literature, the automata are allowed to
share clocks, i.e. transitions of one automaton may be guarded by conditions on
the value of clocks reset by another automaton. This is a problem when one
considers implementing such model in a distributed architecture, since reading
clocks a priori requires communications which are not explicitly described in
the model. We focus on the following question: given an NTA A1 || A2 where A2
reads some clocks reset by A1, does there exist an NTA A'1 || A'2 without
shared clocks with the same behavior as the initial NTA? For this, we allow the
automata to exchange information during synchronizations only, in particular by
copying the value of their neighbor's clocks. We discuss a formalization of the
problem and define an appropriate behavioural equivalence. Then we give a
criterion using the notion of contextual timed transition system, which
represents the behavior of A2 when in parallel with A1. Finally, we effectively
build A'1 || A'2 when it exists.


title: Optimum design accounting for the global nonlinear behavior of the model

abstract:
  Among the major difficulties that one may encounter when estimating
parameters in a nonlinear regression model are the nonuniqueness of the
estimator, its instability with respect to small perturbations of the
observations and the presence of local optimizers of the estimation criterion.
We show that these estimability issues can be taken into account at the design
stage, through the definition of suitable design criteria. Extensions of $E$-,
$c$- and $G$-optimality criteria are considered, which when evaluated at a
given $\theta ^0$ (local optimal design), account for the behavior of the model
response $\eta(\theta )$ for $\theta$ far from $\theta ^0$. In particular, they
ensure some protection against close-to-overlapping situations where
$\|\eta(\theta )-\eta(\theta ^0)\|$ is small for some $\theta$ far from $\theta
^0$. These extended criteria are concave and necessary and sufficient
conditions for optimality (equivalence theorems) can be formulated. They are
not differentiable, but when the design space is finite and the set $\Theta$ of
admissible $\theta$ is discretized, optimal design forms a linear programming
problem which can be solved directly or via relaxation when $\Theta$ is just
compact. Several examples are presented.


title: Bivariate copulas defined from matrices

abstract:
  We propose a semiparametric family of copulas based on a set of orthonormal
functions and a matrix. This new copula permits to reach values of Spearman's
Rho arbitrarily close to one without introducing a singular component.
Moreover, it encompasses several extensions of FGM copulas as well as copulas
based on partition of unity such as Bernstein or checkerboard copulas. Finally,
it is also shown that projection of arbitrary densities of copulas onto tensor
product bases can enter our framework.


title:
The stable hyperelliptic locus in genus 3: An application of Porteous
  Formula

abstract:
  We compute the class of the closure of the locus of hyperelliptic curves in
the moduli space of stable genus-3 curves in terms of the tautological class
$\lambda$ and the boundary classes $\delta_0$ and $\delta_1$. The expression of
this class is known, but here we compute it directly, by means of Porteous
Formula, without resorting to blowups or test curves.


title: Magnetic fields of Sun-like stars

abstract:
  Magnetic fields play an important role at all stages of stellar evolution. In
Sun-like stars, they are generated in the outer convective layers. Studying the
large-scale magnetic fields of these stars enlightens our understanding of the
field properties and gives us observational constraints for the field
generation models. In this review, I summarise the current observational
picture of the large-scale magnetic fields of Sun-like stars, in particular
solar-twins and planet-host stars. I discuss the observations of large-scale
magnetic cycles, and compare these cycles to the solar cycle.


title: Spherical Dirac GJMS operator determinants

abstract:
  Motivated by AdS/CFT, the extension is made to spin-half of a scalar
calculation of the conformal anomalies and functional determinants of GJMS
operators. The formal aspects are heuristic but sufficient. A Barnes zeta
function representation again proves effective. The determinants are calculated
for the two factorisations of the gamma-function (intertwiner) form of the GJMS
operator, and shown to be equal, even including the multiplicative anomaly. A
comment is made on the general eigenvalue problem and a few numerical results
are presented. An alternative approach is detailed for odd dimensions and it is
shown that the scalar determinants are expressed in terms of the spinor ones,
and vice versa. An explicit, general form is given.


title: The Energetic Reasoning Checker Revisited

abstract:
  Energetic Reasoning (ER) is a powerful filtering algorithm for the Cumulative
constraint. Unfortunately, ER is generally too costly to be used in practice.
One reason of its bad behavior is that many intervals are considered as
relevant by the checker of ER, although most of them should be ignored. In this
paper, we provide a sharp characterization that allows to reduce the number of
intervals by a factor seven. Our experiments show that associating this checker
with a Time-Table filtering algorithm leads to promising results.


title:
Phonon induced Superconductivity of High Temperatures in Electrical
  Graphene Superlattices

abstract:
  We discuss the BCS theory for electrons in graphene with a superimposed
electrical unidirectional superlattice potential (SL). New Dirac points emerge
together with van Hove singularities (VHS) linking them. We obtain a
superconducting transition temperature $ T_c $ for chemical potentials close to
the VHS assuming that acoustic phonon coupling should be the dominant
mechanism. Pairing of two onsite electrons with one electron close to the $
{\bf K} $ and the other close to the $ -{\bf K} $ point is the most stable pair
formation. The resulting order parameter is almost constant over the entire SL.


title:
Controlled nucleation of topological defects in the stripe domain
  patterns of Lateral multilayers with Perpendicular Magnetic Anisotropy:
  competition between magnetostatic, exchange and misfit interactions

abstract:
  Magnetic lateral multilayers have been fabricated on weak perpendicular
magnetic anisotropy amorphous Nd-Co films in order to perform a systematic
study on the conditions for controlled nucleation of topological defects within
their magnetic stripe domain pattern. A lateral thickness modulation of period
$w$ is defined on the nanostructured samples that, in turn, induces a lateral
modulation of both magnetic stripe domain periods $\lambda$ and average
in-plane magnetization component $M_{inplane}$. Depending on lateral multilayer
period and in-plane applied field, thin and thick regions switch independently
during in-plane magnetization reversal and domain walls are created within the
in-plane magnetization configuration coupled to variable angle grain boundaries
and disclinations within the magnetic stripe domain patterns. This process is
mainly driven by the competition between rotatable anisotropy (that couples the
magnetic stripe pattern to in-plane magnetization) and in-plane shape
anisotropy induced by the periodic thickness modulation. However, as the
structural period $w$ becomes comparable to magnetic stripe period $\lambda$,
the nucleation of topological defects at the interfaces between thin and thick
regions is hindered by a size effect and stripe domains in the different
thickness regions become strongly coupled.


title: Deleting Edges from Ramsey Minimal Examples

abstract:
  If r(s, t) = p, we shall call Kp a Ramsey Minimal Example. We prove that if
r{s,t) = p, and one edge is deleted from the Ramsey Minimal Example, Kp, the
resulting graph no longer has the Ramsey property, that is, its edges can be
colored red or blue so that the "red" subgraph does not contain Ks and the
"blue" subgraph does not contain Kt. The paper is written in an accessible
style explaining the process that led us to make the conjecture and then prove
this result.


title: Towards Application of the RBNK Model

abstract:
  The computational modeling of genetic regulatory networks is now common
place, either by fitting a system to experimental data or by exploring the
behaviour of abstract systems with the aim of identifying underlying
principles. This paper presents an approach to the latter, considering the
response to environmental changes of a well-known model placed upon tunable
fitness landscapes. The effects on genome size and gene connectivity are
explored.


title: Forwarding, Caching and Congestion Control in Named Data Networks

abstract:
  Emerging information-centric networking architectures seek to optimally
utilize both bandwidth and storage for efficient content distribution. This
highlights the need for joint design of traffic engineering and caching
strategies, in order to optimize network performance in view of both current
traffic loads and future traffic demands. We present a systematic framework for
joint dynamic interest request forwarding and dynamic cache placement and
eviction, within the context of the Named Data Networking (NDN) architecture.
The framework employs a virtual control plane which operates on the user demand
rate for data objects in the network, and an actual plane which handles
Interest Packets and Data Packets. We develop distributed algorithms within the
virtual plane to achieve network load balancing through dynamic forwarding and
caching, thereby maximizing the user demand rate that the NDN network can
satisfy. Next, we show that congestion control can be optimally combined with
forwarding and caching within this framework to maximize user utilities subject
to network stability. Numerical experiments within a number of network settings
demonstrate the superior performance of the resulting algorithms for the actual
plane in terms of high user utilities, low user delay, and high rate of cache
hits.


title:
Exceeding the solar cell Shockley-Queisser limit via thermal
  up-conversion of low-energy photons

abstract:
  Maximum efficiency of ideal single-junction photovoltaic (PV) cells is
limited to 33% (for one sun illumination) by intrinsic losses such as band edge
thermalization, radiative recombination, and inability to absorb below-bandgap
photons. This intrinsic thermodynamic limit, named after Shockley and Queisser
(S-Q), can be exceeded by utilizing low-energy photons either via their
electronic up-conversion or via thermophotovoltaic (TPV) conversion process.
However, electronic up-conversion systems have extremely low efficiencies, and
practical temperature considerations limit the operation of TPV converters to
the narrow-gap PV cells. Here we develop a conceptual design of a hybrid TPV
platform, which exploits thermal up-conversion of low-energy photons and is
compatible with conventional silicon PV cells by using spectral and directional
selectivity of the up-converter. The hybrid platform offers
sunlight-to-electricity conversion efficiency exceeding that imposed by the S-Q
limit on the corresponding PV cells across a broad range of bandgap energies,
under low optical concentration (1-300 suns), operating temperatures in the
range 900-1700K, and in simple flat panel designs. We demonstrate maximum
conversion efficiency of 73% under illumination by non-concentrated sunlight. A
detailed analysis of non-ideal hybrid platforms that allows for up to 15% of
absorption/re-emission losses yields limiting efficiency value of 45% for Si PV
cells.


title:
Critical points of multidimensional random Fourier series: variance
  estimates

abstract:
  To any positive number $\varepsilon$ and any nonnegative even Schwartz
function $w:\mathbb{R}\to\mathbb{R}$ we associate the random function
$u^\varepsilon$ on the $m$-torus
$T^m_\varepsilon:=\mathbb{R}^m/(\varepsilon^{-1}\mathbb{Z})^m$ defined as the
real part of the random Fourier series $$ \sum_{\nu\in\mathbb{Z}^m}
X_{\nu,\varepsilon} \exp\bigl(\; 2\pi \varepsilon \sqrt{-1} \;(\nu\cdot
\theta)\;\bigr),$$ where $X_{\nu,\varepsilon}$ are complex independent Gaussian
random variables with variance $w(\varepsilon|\nu|)$. Let $N^\varepsilon$
denote the number of critical points of $u^\varepsilon$. We describe explicitly
two constants $C, C'$ such that as $\varepsilon$ goes to the zero, the
expectation of the random variable $\frac{1}{{\rm
vol}\,(T^m_\varepsilon)}N^\varepsilon$ converges to $C$, while its variance is
extremely small and behaves like $C'\varepsilon^{m}$.


title:
Products of effective topological spaces and a uniformly computable
  Tychonoff Theorem

abstract:
  This article is a fundamental study in computable analysis. In the framework
of Type-2 effectivity, TTE, we investigate computability aspects on finite and
infinite products of effective topological spaces. For obtaining uniform
results we introduce natural multi-representations of the class of all
effective topological spaces, of their points, of their subsets and of their
compact subsets. We show that the binary, finite and countable product
operations on effective topological spaces are computable. For spaces with
non-empty base sets the factors can be retrieved from the products. We study
computability of the product operations on points, on arbitrary subsets and on
compact subsets. For the case of compact sets the results are uniformly
computable versions of Tychonoff's Theorem (stating that every Cartesian
product of compact spaces is compact) for both, the cover multi-representation
and the "minimal cover" multi-representation.


title: A class of generalized additive Runge-Kutta methods

abstract:
  This work generalizes the additively partitioned Runge-Kutta methods by
allowing for different stage values as arguments of different components of the
right hand side. An order conditions theory is developed for the new family of
generalized additive methods, and stability and monotonicity investigations are
carried out. The paper discusses the construction and properties of
implicit-explicit and implicit-implicit,methods in the new framework. The new
family, named GARK, introduces additional flexibility when compared to
traditional partitioned Runge-Kutta methods, and therefore offers additional
opportunities for the development of flexible solvers for systems with multiple
scales, or driven by multiple physical processes.


title: Glassy phase and freezing of log-correlated Gaussian potentials

abstract:
  In this paper, we consider the Gibbs measure associated to a logarithmically
correlated random potential (including two dimensional free fields) at low
temperature. We prove that the energy landscape freezes and enters in the
so-called glassy phase. The limiting Gibbs weights are integrated atomic random
measures with random intensity expressed in terms of the critical Gaussian
multiplicative chaos. This could be seen as a first rigorous step in the
renormalization theory of super-critical Gaussian multiplicative chaos.


title: The Generation of Super-Resolving Single-Photon Path-Entangled State

abstract:
  In this paper, we propose two protocols for generating super-resolving
\textit{single-photon} path-entangled states from general maximally
path-entangled N00N states. We also show that both protocols generate the
desired state with different probabilities depending on the type of detectors
being used. Such super-resolving single-photon path-entangled states preserve
high resolving power but lack the requirement of a multi-photon absorbing
resist, which makes this state a perfect candidate for quantum lithography.


title: Parameterized (in)approximability of subset problems

abstract:
  We discuss approximability and inapproximability in FPT-time for a large
class of subset problems where a feasible solution $S$ is a subset of the input
data and the value of $S$ is $|S|$. The class handled encompasses many
well-known graph, set, or satisfiability problems such as Dominating Set,
Vertex Cover, Set Cover, Independent Set, Feedback Vertex Set, etc. In a first
time, we introduce the notion of intersective approximability that generalizes
the one of safe approximability and show strong parameterized inapproximability
results for many of the subset problems handled. Then, we study approximability
of these problems with respect to the dual parameter $n-k$ where $n$ is the
size of the instance and $k$ the standard parameter. More precisely, we show
that under such a parameterization, many of these problems, while
W[$\cdot$]-hard, admit parameterized approximation schemata.


title: On cross-section computation in the brane-world models

abstract:
  We present Mathematica7 numerical simulation of the process
$pp\rightarrow\mbox{jet}+E_{T}^{miss}$ in the framework of modified
Randall-Sundrum brane-world model with one infinite and $n$ compact extra
dimension. We compare the energy missing signature with the standard model
background $pp\rightarrow \mbox{jet}+\nu \bar{\nu}$, which was simulated at
CompHep. We show that the models with numbers of compact extra dimensions
greater than 4 can be probed at the protons center-of-mass energy equal 14 TeV.
We also find that testing the brane-world models at 7 TeV on the LHC appears to
hopeless.


title:
Playing with Marbles: Structural and Thermodynamic Properties of
  Hard-Sphere Systems

abstract:
  These lecture notes present an overview of equilibrium statistical mechanics
of classical fluids, with special applications to the structural and
thermodynamic properties of systems made of particles interacting via the
hard-sphere potential or closely related model potentials. The exact
statistical-mechanical properties of one-dimensional systems, the issue of
thermodynamic (in)consistency among different routes in the context of several
approximate theories, and the construction of analytical or semi-analytical
approximations for the structural properties are also addressed.


title: Inflation coupled to a Gauss-Bonnet term

abstract:
  The newly released Planck CMB data place tight constraints on slow-roll
inflationary models. Some of commonly discussed inflationary potentials are
disfavored due mainly to the large tensor-to-scalar ratio. In this paper we
show that these potentials may be in good agreement with the Planck data when
the inflaton has a non-minimal coupling to the Gauss-Bonnet term. Moreover,
such a coupling violates the consistency relation between the tensor spectral
index and tensor-to-scalar ratio. If the tensor spectral index is allowed to
vary freely, the Planck constraints on the tensor-to-scalar ratio are slightly
improved.


title: How many is different? Answer from ideal Bose gas

abstract:
  How many $\mathrm{H_{2}O}$ molecules are needed to form water? While the
precise answer is not known, it is clear that the answer should be a finite
number rather than infinity. We revisit with care the ideal Bose gas confined
in a cubic box which is discussed in most statistical physics textbooks. We
show that the isobar of the ideal gas zigzags on the temperature-volume plane
featuring a `boiling-like' discrete phase transition, provided the number of
particles is equal to or greater than a particular value: 7616. This
demonstrates for the first time how a finite system can feature a mathematical
singularity and realize the notion of `Emergence', without resorting to the
thermodynamic limit.

categories: cond-mat.stat-mech cond-mat.quant-gas hep-th math-ph math.MP


title:
Disorder Correlation Frequency Controlled Diffusion in the
  Jaynes-Cummings-Hubbard Model

abstract:
  We investigate time-dependent stochastic disorder in the one-dimensional
Jaynes-Cummings-Hubbard model and show that it gives rise to diffusive
behaviour. We find that disorder correlation frequency is effective in
controlling the level of diffusivity. In the defectless system the mean squared
displacement (MSD), which is a measure of the diffusivity, increases with
increasing disorder frequency. Contrastingly, when static defects are present
the MSD increases with disorder frequency only at lower frequencies; at higher
frequencies, increasing disorder frequency actually reduces the MSD.