title:
Finding normal bases over finite fields with prescribed trace
  self-orthogonal relations

abstract:
  Normal bases and self-dual normal bases over finite fields have been found to
be very useful in many fast arithmetic computations. It is well-known that
there exists a self-dual normal basis of $\mathbb{F}_{2^n}$ over $\mathbb{F}_2$
if and only if $4\nmid n$. In this paper, we prove there exists a normal
element $\alpha$ of $\mathbb{F}_{2^n}$ over $\mathbb{F}_{2}$ corresponding to a
prescribed vector $a=(a_0,a_1,...,a_{n-1})\in \mathbb{F}_2^n$ such that
$a_i={Tr}_{2^n|2}(\alpha^{1+2^i})$ for $0\leq i\leq n-1$, where $n$ is a
2-power or odd, if and only if the given vector $a$ is symmetric ($a_i=a_{n-i}$
for all $i, 1\leq i\leq n-1$), and one of the following is true.
  1) $n=2^s\geq 4$, $a_0=1$, $a_{n/2}=0$, $\sum\limits_{1\leq i\leq n/2-1,
(i,2)=1}a_i=1$;
  2) $n$ is odd, $(\sum\limits_{0\leq i\leq n-1}a_ix^i,x^n-1)=1$.
  Furthermore we give an algorithm to obtain normal elements corresponding to
prescribed vectors in the above two cases. For a general positive integer $n$
with $4|n$, some necessary conditions for a vector to be the corresponding
vector of a normal element of $\mathbb{F}_{2^n}$ over $\mathbb{F}_{2}$ are
given. And for all $n$ with $4|n$, we prove that there exists a normal element
of $\mathbb{F}_{2^n}$ over $\mathbb{F}_2$ such that the Hamming weight of its
corresponding vector is 3, which is the lowest possible Hamming weight.


title:
GenomeFingerprinter and universal genome fingerprint analysis for
  systematic comparative genomics

abstract:
  How to compare whole genome sequences at large scale has not been achieved
via conventional methods based on pair-wisely base-to-base comparison;
nevertheless, no attention was paid to handle in-one-sitting a number of
genomes crossing genetic category (chromosome, plasmid, and phage) with farther
divergences (much less or no homologous) over large size ranges (from Kbp to
Mbp). We created a new method, GenomeFingerprinter, to unambiguously produce
three-dimensional coordinates from a sequence, followed by one
three-dimensional plot and six two-dimensional trajectory projections to
illustrate whole genome fingerprints. We further developed a set of concepts
and tools and thereby established a new method, universal genome fingerprint
analysis. We demonstrated their applications through case studies on over a
hundred of genome sequences. Particularly, we defined the total genetic
component configuration (TGCC) (i.e., chromosome, plasmid, and phage) for
describing a strain as a system, and the universal genome fingerprint map
(UGFM) of TGCC for differentiating a strain as a universal system, as well as
the systematic comparative genomics (SCG) for comparing in-one-sitting a number
of genomes crossing genetic category in diverse strains. By using UGFM,
UGFM-TGCC, and UGFM-TGCC-SCG, we compared a number of genome sequences with
farther divergences (chromosome, plasmid, and phage; bacterium, archaeal
bacterium, and virus) over large size ranges (6Kbp~5Mbp), giving new insights
into critical problematic issues in microbial genomics in the post-genomic era.
This paper provided a new method for rapidly computing, geometrically
visualizing, and intuitively comparing genome sequences at fingerprint level,
and hence established a new method of universal genome fingerprint analysis for
systematic comparative genomics.


title: Efficient Parallel Computation of the Estimated Covariance Matrix

abstract:
  Computation of a signal's estimated covariance matrix is an important
building block in signal processing, e.g., for spectral estimation. Each matrix
element is a sum of products of elements in the input matrix taken over a
sliding window. Any given product contributes to multiple output elements,
thereby complicating parallelization. We present a novel algorithm that attains
very high parallelism without repeating multiplications or requiring inter-core
synchronization. Key to this is the assignment to each core of distinct
diagonal segments of the output matrix, selected such that no multiplications
need to be repeated yet only one core writes to any given output-matrix
element, and exploitation of a shared memory (including L1 cache) that obviates
the need for a corresponding awkward partitioning of the memory among cores.
Implementation on Plurality's HyperCore shared-memory many-core architecture
demonstrates linear speedup of up to 64 cores and speedups of ~85X for 128
cores. On an x86 system we demonstrate that the new algorithm has consider
parallel speedups but also show that a sequential implementation of the new
algorithm outperforms the parallel implementation of the baseline approach. On
a quad-core x86 system, the new algorithm is 20X faster than sequential
baseline and 5X than parallel implementation of the baseline.


title:
Analytical studies on the Sunyaev Zeldovich effect in the cluster of
  galaxies for three Lorentz frames

abstract:
  We study the Sunyaev-Zeldovich effect for clusters of galaxies. The Boltzmann
equations for the CMB photon distribution function are studied in three Lorentz
frames. We clarify the relations of the SZ effects among the different Lorentz
frames. We derive analytic expressions for the photon redistribution functions.
These formulas are applicable to the nonthermal electron distributions as well
as the standard thermal distribution. We show that the Fokker-Planck expansion
of the Boltzmann equation can be expanded by the power series of the diffusion
operator of the original Kompaneets equation.


title:
Topological Many-Body States in Quantum Antiferromagnets via Fuzzy
  Super-Geometry

abstract:
  Recent vigorous investigations of topological order have not only discovered
new topological states of matter but also shed new light to "already known"
topological states. One established example with topological order is the
valence bond solid (VBS) states in quantum antiferromagnets. The VBS states are
disordered spin liquids with no spontaneous symmetry breaking but most
typically manifest topological order known as hidden string order on 1D chain.
Interestingly, the VBS models are based on mathematics analogous to fuzzy
geometry. We review applications of the mathematics of fuzzy super-geometry in
the construction of supersymmetric versions of VBS (SVBS) states, and give a
pedagogical introduction of SVBS models and their properties [arXiv:0809.4885,
1105.3529, 1210.0299]. As concrete examples, we present detail analysis of
supersymmetric versions of SU(2) and SO(5) VBS states, i.e. UOSp(N|2) and
UOSp(N|4) SVBS states whose mathematics are closely related to fuzzy two- and
four-superspheres. The SVBS states are physically interpreted as hole-doped VBS
states with superconducting property that interpolate various VBS states
depending on value of a hole-doping parameter. The parent Hamiltonians for SVBS
states are explicitly constructed, and their gapped excitations are derived
within the single-mode approximation on 1D SVBS chains. Prominent features of
the SVBS chains are discussed in detail, such as a generalized string order
parameter and entanglement spectra. It is realized that the entanglement
spectra are at least doubly degenerate regardless of the parity of bulk
(super)spins. Stability of topological phase with supersymmetry is discussed
with emphasis on its relation to particular edge (super)spin states.


title: The Shannon-McMillan Theorem for AF $C^*$-systems

abstract:
  We give a new proof of quantum Shannon-McMillan theorem, extending it to AF
$C^*$-systems. Our proof is based on the variational principle, instead of the
classical Shannon-McMillan theorem.


title: Distributed optimization over time-varying directed graphs

abstract:
  We consider distributed optimization by a collection of nodes, each having
access to its own convex function, whose collective goal is to minimize the sum
of the functions. The communications between nodes are described by a
time-varying sequence of directed graphs, which is uniformly strongly
connected. For such communications, assuming that every node knows its
out-degree, we develop a broadcast-based algorithm, termed the
subgradient-push, which steers every node to an optimal value under a standard
assumption of subgradient boundedness. The subgradient-push requires no
knowledge of either the number of agents or the graph sequence to implement.
Our analysis shows that the subgradient-push algorithm converges at a rate of
$O(\ln(t)/\sqrt{t})$, where the constant depends on the initial values at the
nodes, the subgradient norms, and, more interestingly, on both the consensus
speed and the imbalances of influence among the nodes.


title:
Effects of n-type doping in InAs/GaAs quantum dot layer on
  current-voltage characteristic of intermediate band solar cells

abstract:
  We investigated the current-voltage characteristic of InAs/GaAs quantum dot
intermediate band solar cells (QD IBSCs) with different n-type doping density
in the QD layer. The n-type doping evidently increases the open circuit
voltage, meanwhile decreases the short circuit current density, and leads to
the conversion efficiency approaching that of the control solar cell, that is
the major role of n-type doping is to suppress the effects of QDs on the
current-voltage characteristic. Our model adopts practical parameters for
simulation rather than those from detailed balanced method, so that the results
in our simulation are not overestimated.


title:
A Big-Bang Nucleosynthesis Limit on the Neutral Fermion Decays into
  Neutrinos

abstract:
  Using the primordial helium abundance, an upper limit to the magnetic moments
for Dirac neutrinos had been provided by imposing restrictions on the number of
the additional helicity states. Considering non-thermal photons produced in the
decay of the heavy sterile mass eigenstates due to the neutrino magnetic
moment, we explore the constraints imposed by the observed abundances of all
the light elements produced during the Big Bang nucleosynthesis.


title:
Intelligent Approaches to interact with Machines using Hand Gesture
  Recognition in Natural way: A Survey

abstract:
  Hand gestures recognition (HGR) is one of the main areas of research for the
engineers, scientists and bioinformatics. HGR is the natural way of Human
Machine interaction and today many researchers in the academia and industry are
working on different application to make interactions more easy, natural and
convenient without wearing any extra device. HGR can be applied from games
control to vision enabled robot control, from virtual reality to smart home
systems. In this paper we are discussing work done in the area of hand gesture
recognition where focus is on the intelligent approaches including soft
computing based methods like artificial neural network, fuzzy logic, genetic
algorithms etc. The methods in the preprocessing of image for segmentation and
hand image construction also taken into study. Most researchers used fingertips
for hand detection in appearance based modeling. Finally the comparison of
results given by different researchers is also presented.


title:
Vapor-liquid coexistence of the Stockmayer fluid in nonuniform external
  fields

abstract:
  We investigate the structure and phase behavior of the Stockmayer fluid in
the presence of nonuniform electric fields using molecular simulation. We find
that an initially homogeneous vapor phase undergoes a local phase separation in
a nonuniform field due to the combined effect of the field gradient and the
fluid vapor--liquid equilibrium. This results in a high density fluid
condensing in the strong field region. The system polarization exhibits a
strong field dependence due to the fluid condensation.


title:
Comprehensive Analysis on the Vulnerability and Efficiency of P2P
  Networks under Static Failures and Targeted Attacks

abstract:
  Peer to peer systems are the networks consisting of a group of nodes possible
to be as wide as the Internet. These networks are required of evaluation
mechanisms and distributed control and configurations, so each peer will be
able to communicate with other peers. Resilience to faults, failures and
attacks, are the main requirements of most communication systems and networks
today. Thus, since P2P networks can be individually used as an infrastructure
and an alternative for many other communication networks, they have to be more
reliable, and resilient to the faults, failures and attacks compared to the
client and server approach. In this work, we present a detailed study on the
behavior of various P2P networks toward faults and failures, and focus on
fault-tolerance subject. We consider two different static failure scenarios:
a)a random strategy in which nodes or edges of the network will be removed with
an equal probability and without any knowledge of the networks infrastructure,
b)a targeted strategy that uses some information about the nodes, and in which
the nodes with the highest degree have the most priority to be attacked. By
static faults, we mean a situation where the nodes or components encounter some
faults before the network starts to work or through its operation, and will
remain faulty to the end of the work session. Our goal is to introduce various
measures to analyzing P2P networks evaluating their vulnerability rate. The
presented criteria can be used for evaluating the reliability and vulnerability
of P2P networks toward both random and targeted failures. There is no limit to
the number and types of failures, the presented measures are able to be used
for different types of failures and even a wide range of networks.


title: Asymptotic behavior of the eigenvalues of the p(x)-Laplacian

abstract:
  We obtain asymptotic estimates for the eigenvalues of the p(x)-Laplacian
defined consistently with a homogeneous notion of first eigenvalue recently
introduced in the literature.


title: Flux exchange in inhomogeneous type-II superconductors

abstract:
  The vortex hopping motion in a type-II superconductor determines the
current-carrying ability and consequently the application fields of the
superconductor. However, it is not clear how the vortices hop between the
different pinning regions in the superconductor. Here we proposed that there
should be magnetic \textit{flux exchange} between two contacting pinning
regions. A system of differential equations was constructed to describe the
flux exchange phenomenon. The qualitative analysis methods were used. The
approximate numerical solutions and approximate analytical solutions of the
system were obtained. The results show that the flux exchange reduces the
internal field in a weak pinning region, but increases the internal field in a
strong pinning region. Moreover, the flux exchange phenomenon is strongly
influenced by the superconductor's geometrical size.


title:
On minimal periods of solutions of higher order functional differential
  equations

abstract:
  We show that a problem on minimal periods of solutions of Lipschitz
functional differential equations is closely related to the unique solvability
of the periodic problem for linear functional differential equations. Sharp
bounds for minimal periods of non-constant solutions of higher order functional
differential equations with different Lipschitz nonlinearities are obtained.


title: 0-th quantization or quantum (information) theory in 42 minutes

abstract:
  We present a concise introduction of basic concepts in quantum information
theory and quantum mechanics prepared as an introduction for a general
audience. In our approach the rules of quantum mechanics are presented in a
simple form of rules describing the method of constructing quantum objects
corresponding to classical objects. As a byproduct of the introduced approach,
we present some alternative rules and use them to describe basic ingredients of
quantum information theory using different types of objects.


title: On an entropy of $Z_+^k$-actions

abstract:
  In this paper, a definition of entropy for $\mathbb{Z}_+^k(k\geq2)$-actions
due to S. Friedland \cite{Friedland} is studied. Unlike the traditional
definition, it may take a nonzero value for actions whose generators have
finite (even zero) entropy as single transformations. Some basic properties are
investigated and its value for the $\mathbb{Z}_+^k$-actions on circles
generated by expanding endomorphisms is given. Moreover, an upper bound of this
entropy for the $\mathbb{Z}_+^k$-actions on tori generated by expanding
endomorphisms is obtained via the preimage entropies, which are entropy-like
invariants depending on the "inverse orbits" structure of the system.


title: Floquet generation of Majorana end modes and topological invariants

abstract:
  We show how Majorana end modes can be generated in a one-dimensional system
by varying some of the parameters in the Hamiltonian periodically in time. The
specific model we consider is a chain containing spinless electrons with a
nearest-neighbor hopping amplitude, a p-wave superconducting term and a
chemical potential; this is equivalent to a spin-1/2 chain with anisotropic XY
couplings between nearest neighbors and a magnetic field applied in the
z-direction. We show that varying the chemical potential (or magnetic field)
periodically in time can produce Majorana modes at the ends of a long chain. We
discuss two kinds of periodic driving, periodic delta-function kicks and a
simple harmonic variation with time. We discuss some distinctive features of
the end modes such as the inverse participation ratio of their wave functions
and their Floquet eigenvalues which are always equal to +/- 1 for time-reversal
symmetric systems. For the case of periodic delta-function kicks, we use the
effective Hamiltonian of a system with periodic boundary conditions to define
two topological invariants. The first invariant is a well-known winding number
while the second invariant has not appeared in the literature before. The
second invariant is more powerful in that it always correctly predicts the
numbers of end modes with Floquet eigenvalues equal to +1 and -1, while the
first invariant does not. We find that the number of end modes can become very
large as the driving frequency decreases. We show that periodic delta-function
kicks in the hopping and superconducting terms can also produce end modes.
Finally, we study the effect of electron-phonon interactions (which are
relevant at finite temperatures) and a random noise in the chemical potential
on the Majorana modes.


title:
Finding a way to determine the pion distribution amplitude from the
  experimental data

abstract:
  It is believed that one can extract more accurate information of the pion
distribution amplitude from the pion-photon transition form factor (TFF) due to
the single pion in this process. However the BABAR and Belle data of the
pion-photon TFF have a big difference for $Q^2\in [15,40]$ GeV$^2$, and at
present, the pion DA can not be definitely determined from the pion-photon TFF.
it is crucial to find the right pion DA behavior and to determine which data is
more reliable. In this letter, we perform a combined analysis of the most
existing data of the processes involving pion by using a general model for the
pion wavefunction/DA. Such a DA model can mimic all the existed pion DA
behaviors, whose parameters can be fixed by the constraints from the processes
$\pi^0\to\gamma\gamma$, $\pi\to\mu\nu$, $B\to\pi l \nu$, and etc. Especially,
we examine the $B \rightarrow \pi$ transition form factors that provides
another constraint to the parameter $B$ in our DA model, which results in $B
\in[0.00,0.29]$. This inversely shows that the predicted curve for the
pion-photon TFF is between the BABAR and Belle data in the region $Q^2\in$
$[15,40]$ GeV$^2$. It will be tested by coming more accurate data at large
$Q^2$ region, and the definite behavior of pion DA can be concluded finally.


title:
A symmetric unimodal decomposition of the derangement polynomial of type
  $B$

abstract:
  The derangement polynomial $d_n (x)$ for the symmetric group enumerates
derangements by the number of excedances. The derangement polynomial $d^B_n(x)$
for the hyperoctahedral group is a natural type $B$ analogue. A new
combinatorial formula for this polynomial is given in this paper. This formula
implies that $d^B_n (x)$ decomposes as a sum of two nonnegative, symmetric and
unimodal polynomials whose centers of symmetry differ by a half and thus
provides a new transparent proof of its unimodality. A geometric
interpretation, analogous to Stanley's interpretation of $d_n (x)$ as the local
$h$-polynomial of the barycentric subdivision of the simplex, is given to one
of the summands of this decomposition. This interpretation leads to a unimodal
decomposition and a new formula for the Eulerian polynomial of type $B$. The
various decomposing polynomials introduced here are also studied in terms of
recurrences, generating functions, combinatorial interpretations, expansions
and real-rootedness.


title: Minimal Generating Sets of Lattice Ideals

abstract:
  Let $L\subset \mathbb{Z}^n$ be a lattice and $I_L=\langle x^{\bf u}-x^{\bf
v}:\ {\bf u}-{\bf v}\in L\rangle$ be the corresponding lattice ideal in
$\Bbbk[x_1,\ldots, x_n]$, where $\Bbbk$ is a field. In this paper we describe
minimal binomial generating sets of $I_L$ and their invariants. We use as a
main tool a graph construction on equivalence classes of fibers of $I_L$. As
one application of the theory developed we characterize binomial complete
intersection lattice ideals, a longstanding open problem in the case of
non-positive lattices.


title: On Milgram's construction and the Duke embedding conjectures

abstract:
  Milgram constructed a 28-vertex cubic graph of genus 4 that disproved Duke's
conjecture relating Betti number to minimum genus. We apply Milgram's method to
construct to find graphs of higher genus violating Duke's conjecture, which
gives a sharper bound on that relationship. These graphs are also
counterexamples to a related conjecture of Nordhaus et al. on the relationship
between minimum and maximum genera of graphs. As a side note, we give a simpler
proof of correctness for Milgram's method and we show that Duke's conjecture is
true for genus at most 3.


title:
Exponential Approximation of Bandlimited Random Processes from
  Oversampling

abstract:
  The Shannon sampling theorem for bandlimited wide sense stationary random
processes was established in 1957, which and its extensions to various random
processes have been widely studied since then. However, truncation of the
Shannon series suffers the drawback of slow convergence. Specifically, it is
well-known that the mean-square approximation error of the truncated series at
$n$ points sampled at the exact Nyquist rate is of the order
$O(\frac1{\sqrt{n}})$. We consider the reconstruction of bandlimited random
processes from finite oversampling points, namely, the distance between
consecutive points is less than the Nyquist sampling rate. The optimal
deterministic linear reconstruction method and the associated intrinsic
approximation error are studied. It is found that one can achieve
exponentially-decaying (but not faster) approximation errors from oversampling.
Two practical reconstruction methods with exponential approximation ability are
also presented.


title:
Tail asymptotics for the supercritical Galton-Watson process in the
  heavy-tailed case

abstract:
  As well known, for a supercritical Galton-Watson process $Z_n$ whose
offspring distribution has mean $m>1$, the ratio $W_n:=Z_n/m^n$ has a.s. limit,
say $W$. We study tail behaviour of the distributions of $W_n$ and $W$ in the
case where $Z_1$ has heavy-tailed distribution, that is, $\E e^{\lambda
Z_1}=\infty$ for every $\lambda>0$. We show how different types of
distributions of $Z_1$ lead to different asymptotic behaviour of the tail of
$W_n$ and $W$. We describe the most likely way how large values of the process
occur.


title: $WW\gamma/Z$ production in the Randall-Sundrum model at LHC and CLIC

abstract:
  We study the $W^+W^-\gamma(Z)$ productions at both the CERN Large Hadron
Collider (LHC) and the Compact Linear Collider (CLIC) in the framework of the
Randall-Sundrum (RS) model. The impacts of the virtual RS Kaluza-Klein (KK)
graviton on these processes are studied and compared with the standard model
(SM) background. We present the integrated and differential cross sections in
both the RS model and the SM. The results show that the relative RS
discrepancies at the CLIC differ from those at the LHC, particularly in the
transverse momentum and rapidity distributions. We also find that the RS
signature performance, as a result of the resonance character of the RS
KK-graviton spectrum, is distinctively unlike that in the large extra
dimensions model. We conclude that the CLIC with unprecedented precision and
high center-of-mass energy has a potential advantage over the LHC in exploring
the effects of the RS KK graviton on the $W^+W^-\gamma(Z)$ production
processes.


title:
Improving adaptation of ubiquitous recommander systems by using
  reinforcement learning and collaborative filtering

abstract:
  The wide development of mobile applications provides a considerable amount of
data of all types (images, texts, sounds, videos, etc.). Thus, two main issues
have to be considered: assist users in finding information and reduce search
and navigation time. In this sense, context-based recommender systems (CBRS)
propose the user the adequate information depending on her/his situation. Our
work consists in applying machine learning techniques and reasoning process in
order to bring a solution to some of the problems concerning the acceptance of
recommender systems by users, namely avoiding the intervention of experts,
reducing cold start problem, speeding learning process and adapting to the
user's interest. To achieve this goal, we propose a fundamental modification in
terms of how we model the learning of the CBRS. Inspired by models of human
reasoning developed in robotic, we combine reinforcement learning and
case-based reasoning to define a contextual recommendation process based on
different context dimensions (cognitive, social, temporal, geographic). This
paper describes an ongoing work on the implementation of a CBRS based on a
hybrid Q-learning (HyQL) algorithm which combines Q-learning, collaborative
filtering and case-based reasoning techniques. It also presents preliminary
results by comparing HyQL and the standard Q-Learning w.r.t. solving the cold
start problem.


title: On the Performance Limits of Map-Aware Localization

abstract:
  Establishing bounds on the accuracy achievable by localization techniques
represents a fundamental technical issue. Bounds on localization accuracy have
been derived for cases in which the position of an agent is estimated on the
basis of a set of observations and, possibly, of some a priori information
related to them (e.g., information about anchor positions and properties of the
communication channel). In this manuscript new bounds are derived under the
assumption that the localization system is map-aware, i.e., it can benefit not
only from the availability of observations, but also from the a priori
knowledge provided by the map of the environment where it operates. Our results
show that: a) map-aware estimation accuracy can be related to some features of
the map (e.g., its shape and area) even though, in general, the relation is
complicated; b) maps are really useful in the presence of some combination of
low signal-to-noise ratios and specific geometrical features of the map (e.g.,
the size of obstructions); c) in most cases, there is no need of refined maps
since additional details do not improve estimation accuracy.


title: Trajectory Based Optimal Segment Computation in Road Network Databases

abstract:
  Finding a location for a new facility such that the facility attracts the
maximal number of customers is a challenging problem. Existing studies either
model customers as static sites and thus do not consider customer movement, or
they focus on theoretical aspects and do not provide solutions that are shown
empirically to be scalable. Given a road network, a set of existing facilities,
and a collection of customer route traversals, an optimal segment query returns
the optimal road network segment(s) for a new facility. We propose a practical
framework for computing this query, where each route traversal is assigned a
score that is distributed among the road segments covered by the route
according to a score distribution model. The query returns the road segment(s)
with the highest score. To achieve low latency, it is essential to prune the
very large search space. We propose two algorithms that adopt different
approaches to computing the query. Algorithm AUG uses graph augmentation, and
ITE uses iterative road-network partitioning. Empirical studies with real data
sets demonstrate that the algorithms are capable of offering high performance
in realistic settings.


title: Nonequilibrium identities of granular vibrating beds

abstract:
  We derive the integral fluctuation theorem around a nonequilibrium stationary
state for frictionless and soft core granular particles under an external
vibration achieved by a balance between an external vibration and inelastic
collisions. We also discuss the connection between the integral fluctuation
theorem and the generalized Green-Kubo formula.


title: Real-time vector field tracking with a cold-atom magnetometer

abstract:
  We demonstrate a fast three-axis optical magnetometer using cold,
optically-trapped $^{87}$Rb gas as a sensor. By near-resonant Faraday rotation
we record the free-induction decay following optical pumping along two
orthogonal axes to obtain the three field components and one gradient
component. A single measurement achieves shot-noise limited sub-nT sensitivity
in 1 ms, with transverse spatial resolution of $\sim$ 20 $\mu$m. We make a
detailed analysis of the shot-noise-limited sensitivity.


title: Inelastic processes in K^(+)- He collisions in energy range 0.7 - 10 keV

abstract:
  Absolute cross sections for charge exchange, ionization, stripping and
excitation in K^(+) - He collisions were measured in the ion energy range 0.7 -
10 keV. The experimental data and the schematic correlation diagrams are used
to analyze and determine the mechanisms for these processes. The increase of
the excitation probability of inelastic channels with the angle of scattering
is revealed. An exceptionally highly excited state of He is observed and a
peculiarity for the excitation function of the resonance line is explained. The
intensity ratio for the excitation of the K II \lambda = 60.1 nm and \lambda =
61.2 nm lines is 5:1 which indicates the high probability for excitation of the
singlet resonance level $^{1}$P$_{1}$ compared to the triplet level
$^{3}$P$_{1}$. The similarity of the population of the 4p state of the
potassium ion and atom as well as the anomalously small values of the
excitation cross sections are explained.


title: Mini-Batch Primal and Dual Methods for SVMs

abstract:
  We address the issue of using mini-batches in stochastic optimization of
SVMs. We show that the same quantity, the spectral norm of the data, controls
the parallelization speedup obtained for both primal stochastic subgradient
descent (SGD) and stochastic dual coordinate ascent (SCDA) methods and use it
to derive novel variants of mini-batched SDCA. Our guarantees for both methods
are expressed in terms of the original nonsmooth primal problem based on the
hinge-loss.


title: Transient Accelerating Scalar Models with Exponential Potential

abstract:
  We study a known class of scalar dark energy models in which the potential is
of exponential type and the current accelerating era is transient. We find
that, although a decelerating era will return in future, however, when
extrapolating the model back to the earlier stages ($z \gtrsim 4$), the scalar
dark energy becomes dominant over the matter. So these models do not have the
desired tracking behavior, and the predicted transient period of acceleration
can not be adopted into the standard scenario of Big Bang cosmology. When
couplings between the scalar field and the matter are introduced, the models
still has the problem, only the time of deceleration return will be varied. To
achieve re-deceleration, one has to turn to alternative models that are
consistent with the standard Big Bang scenario.


title: Capturing Patterns via Parsimonious t Mixture Models

abstract:
  This paper exploits a simplified version of the mixture of multivariate
t-factor analyzers (MtFA) for robust mixture modelling and clustering of
high-dimensional data that frequently contain a number of outliers. Two classes
of eight parsimonious t mixture models are introduced and computation of
maximum likelihood estimates of parameters is achieved using the alternating
expectation conditional maximization (AECM) algorithm. The usefulness of the
methodology is illustrated through applications of image compression and
compact facial representation.


title: Proposition d'une technique de gestion de projet dans les startups

abstract:
  This project is part of the development of mobile CRM. It aims to develop a
management application client named NOMALYS. This application allows the
commercial and business leaders to see their CRM Mobile. We have focused in
this project on the techniques of projects management, this study allowed to
classify different techniques for managing software projects and proposed the
most closely technique that match the needs of the studied company.


title: Graded quiver varieties and derived categories

abstract:
  Inspired by recent work of Hernandez-Leclerc and Leclerc-Plamondon we
investigate the link between Nakajima's graded affine quiver varieties
associated with an acyclic connected quiver Q and the derived category of Q. As
Leclerc-Plamondon have shown, the points of these varieties can be interpreted
as representations of a category, which we call the (singular) Nakajima
category S. We determine the quiver of S and the number of minimal relations
between any two given vertices. We construct a delta-functor Phi taking each
finite-dimensional representation of S to an object of the derived category of
Q. We show that the functor Phi establishes a bijection between the strata of
the graded affine quiver varieties and the isomorphism classes of objects in
the image of Phi. If the underlying graph of Q is an ADE Dynkin diagram, the
image is the whole derived category; otherwise, it is the category of "line
bundles over the non commutative curve given by Q". We show that the
degeneration order between strata corresponds to Jensen-Su-Zimmermann's
degeneration order on objects of the derived category. Moreover, if Q is an ADE
Dynkin quiver, the singular category S is weakly Gorenstein of dimension 1 and
its derived category of singularities is equivalent to the derived category of
Q.


title: On the finiteness of uniform sinks

abstract:
  We study the finiteness of uniform sinks for flow. Precisely, we prove that,
for $\alpha>0$ $T>0$, if a vector field $X$ has only hyperbolic singularities
or sectionally dissipative singularities, then $X$ can have only finitely many
$(\alpha,T)$-uniform sinks. This is a generalized version of a theorem of Liao


title: Spin Dynamics of Trimers on a Distorted Kagom\'e Lattice

abstract:
  We treat the ground state, elementary excitations, and neutron scattering
cross section for a system of trimers consisting of three tightly bound spins
1/2 on a distorted Kagom\'e lattice, subject to isotropic nearest neighbor
(usually antiferromagnetic) Heisenberg interactions. The interactions between
trimers are assumed to be weak compared to the intra trimer interactions. We
compare the spin-wave excitation spectrum of trimers with that obtained from
standard spin-wave theory and attribute the differences at low energy to the
fact that the trimer formulation includes exactly the effects of intra-trimer
zero point motion. Application to existing systems is briefly discussed.


title:
Populations of rotating stars. - I. Models from 1.7 to 15 Msun at Z =
  0.014, 0.006, and 0.002 with {\Omega}/{\Omega}crit between 0 and 1

abstract:
  B-type stars are known to rotate at various velocities, including very fast
rotators near the critical velocity as the Be stars. In this paper, we provide
stellar models covering the mass range between 1.7 to 15 Msun, which includes
the typical mass of known Be stars, at Z = 0.014, 0.006, and 0.002 and for an
extended range of initial velocities on the zero-age main sequence. We used the
Geneva stellar-evolution code, including the effects of shellular rotation,
with a numerical treatment that has been improved so the code can precisely
track the variation in the angular momentum content of the star as it changes
under the influence of radiative winds and/or mechanical mass loss. We discuss
the impact of the initial rotation rate on the tracks in the
Hertzsprung-Russell diagram, the main-sequence (MS) lifetimes, the evolution of
the surface rotation and abundances, as well as on the ejected masses of
various isotopes. Among the new results obtained from the present grid we find
that 1) fast-rotating stars with initial masses around 1.7 Msun present at the
beginning of the core hydrogen-burning phase quite small convective cores with
respect to their slowly rotating counterparts. This fact may be interesting to
keep in mind in the framework of the asteroseismic studies of such stars. 2)
The contrast between the core and surface angular velocity is higher in slower
rotating stars. The values presently obtained are in agreement with the very
few values obtained for B-type stars from asteroseismology. 3) At Z = 0.002,
the stars in the mass range of 1.7 to 3 Msun with a mean velocity on the MS of
the order of 150 km/s show N/H enhancement superior to 0.2 dex at mid-MS, and
superior to 0.4 dex at the end of the MS phase. At solar metallicity the
corresponding values are below 0.2 dex at any time in the MS.


title:
Poletsky-Stessin Hardy Spaces on Domains Bounded by An Analytic Jordan
  Curve in $\mathbb{C}$

abstract:
  We study Poletsky-Stessin Hardy spaces that are generated by continuous,
subharmonic exhaustion functions on a domain $\Omega\subset\mathbb{C}$, that is
bounded by an analytic Jordan curve. Different from Poletsky & Stessin's work
these exhaustion functions are not necessarily harmonic outside of a compact
set but have finite Monge-Amp\'ere mass. We have showed that functions
belonging to Poletsky-Stessin Hardy spaces have a factorization analogous to
classical Hardy spaces and the algebra $A(\Omega)$ is dense in these spaces as
in the classical case ; however, contrary to the classical Hardy spaces,
composition operators with analytic symbols on these Poletsky-Stessin Hardy
spaces need not always be bounded.


title:
Type II Superstring Field Theory: Geometric Approach and Operadic
  Description

abstract:
  We outline the construction of type II superstring field theory leading to a
geometric and algebraic BV master equation, analogous to Zwiebach's
construction for the bosonic string. The construction uses the small Hilbert
space. Elementary vertices of the non-polynomial action are described with the
help of a properly formulated minimal area problem. They give rise to an
infinite tower of superstring field products defining a $\mathcal{N}=1$
generalization of a loop homotopy Lie algebra, the genus zero part generalizing
a homotopy Lie algebra. Finally, we give an operadic interpretation of the
construction.


title: Exterior degree of infinite groups

abstract:
  The exterior degree of a finite group has been introduced in [P. Niroomand
and R. Rezaei, On the exterior degree of finite groups, Comm. Algebra 39
(2011), 335--343] and the present paper is devoted to study the exterior degree
of infinite groups. We find some inequalities of combinatorial nature, which
generalize those of the finite case and allow us to get structural restrictions
for the whole group.


title:
Bilipschitz and quasiconformal rotation, stretching and multifractal
  spectra

abstract:
  We establish sharp bounds for simultaneous local rotation and
H\"older-distortion of planar quasiconformal maps. In addition, we give sharp
estimates for the corresponding joint quasiconformal multifractal spectrum,
based on new estimates for Burkholder functionals with complex parameters. As a
consequence, we obtain optimal rotation estimates also for bi-Lipschitz maps.


title:
From E. Fermi to Fermi-LAT: watching particle acceleration in supernova
  remnants

abstract:
  Supernova remnants (SNRs) have been regarded for many decades as the sources
of Galactic cosmic rays (CRs) up to a few PeV. However, only with the advent of
Fermi-LAT it has been possible to detect - at least in some SNRs - \gamma-rays
whose origin is unequivocally hadronic, namely due to the decay of neutral
pions produced by collisions between relativistic nuclei and the background
plasma. When coupled with observations in other bands (from radio to TeV
\gamma-rays), Fermi-LAT data present evidence for CR spectra significantly
steeper than the standard prediction of diffusive shock acceleration, forcing
us to rethink our theoretical understanding of efficient particle energization
at strong shocks. We outline how, by including the effects of CR-triggered
magnetic field amplification, it is possible to reconcile non-linear models of
diffusive shock acceleration with \gamma-ray observations, in particular
providing a successful application of such a theory to Tycho's SNR. Finally, we
show how kinetic simulations can investigate the microphysics of the non-linear
coupling of accelerated particles and magnetic fields, probing from first
principles the efficiency of the Fermi mechanism at strong shocks


title: Thin Film Motion of an Ideal Fluid on the Rotating Cylinder Surface

abstract:
  The shallow water equations describing the motion of thin liquid film on the
rotating cylinder surface are obtained. These equations are the analog of the
modified Boussinesq equations for shallow water and the Korteweg-de Vries
equation. It is clear that for rotating cylinder the centrifugal force plays
the role of the gravity. For construction the shallow water equations
(amplitude equations) usual depth-averaged and multi-scale asymptotic expansion
methods are used. Preliminary analysis shows that a thin film of an ideal
incompressible fluid precesses around the axis of the cylinder with velocity
which differs from the angular velocity of rotating cylinder. For the
mathematical model of the liquid film motion the analytical solutions are
obtained by the Tanh-Function method. To illustrate the integrability of the
equations the Painleve analysis is used. The truncated expansion method and
symbolic computation allows to present an auto-Backlund transformation. The
results of analysis show that the exact solutions of the model correspond to
the solitary waves of different types.


title: Using basis sets of scar functions

abstract:
  We present a method to efficiently compute the eigenfunctions of classically
chaotic systems. The key point is the definition of a modified Gram-Schmidt
procedure which selects the most suitable elements from a basis set of scar
functions localized along the shortest periodic orbits of the system. In this
way, one benefits from the semiclassical dynamical properties of such
functions. The performance of the method is assessed by presenting an
application to a quartic two dimensional oscillator whose classical dynamics
are highly chaotic. We have been able to compute the eigenfunctions of the
system using a small basis set. An estimate of the basis size is obtained from
the mean participation ratio. A thorough analysis of the results using
different indicators, such as eigenstate reconstruction in the local
representation, scar intensities, participation ratios, and error bounds, is
also presented.


title: New Results for Sorli's Conjecture on Odd Perfect Numbers - Part II

abstract:
  If $N={q^k}{n^2}$ is an odd perfect number given in Eulerian form, then
Sorli's conjecture predicts that $k=\nu_{q}(N)=1$. In this article, we give
some further results related to this conjecture and those contained in the
papers \cite{Dris} and \cite{Dris2}.
  (withdrawn because of a crucial gap in Theorem 1 [see
https://arxiv.org/pdf/1309.0906.pdf for what is currently provable in this
regard], as well as elementary mistakes in the numerical bounds from pages 2 to
4)


title: Image compression using anti-forensics method

abstract:
  A large number of image forensics methods are available which are capable of
identifying image tampering. But these techniques are not capable of addressing
the anti-forensics method which is able to hide the trace of image tampering.
In this paper anti-forensics method for digital image compression has been
proposed. This anti-forensics method is capable of removing the traces of image
compression. Additionally, technique is also able to remove the traces of
blocking artifact that are left by image compression algorithms that divide an
image into segments during compression process. This method is targeted to
remove the compression fingerprints of JPEG compression.


title: Equidistribution of generalized Dedekind sums and exponential sums

abstract:
  For the generalized Dedekind sums s_{ij}(p,q) defined in association with the
x^{i}y^{j}-coefficient of the Todd power series of the lattice cone in R^2
generated by (1,0) and (q,p), we associate an exponential sum. We obtain this
exponential sum using the cocycle property of the Todd series of 2d cones and
the nonsingular cone decomposition along with the continued fraction of q/p.
Its Weil bound is given for the modulus q, applying the purity theorem of the
cohomology of the related l-adic sheaf due to Denef and Loeser. The Weil type
bound of Denef and Loeser fulfills the Weyl's equidistribution criterion for
R(i,j)q^{i+j-2} s_{ij}(p,q). As a special case, we recover the equidistribution
result of the classical Dedekind sums multiplied by 12 not using the modular
weight of the Dedekind's \eta(\tau).


title: K-stability and parabolic stability

abstract:
  Parabolic structures with rational weights encode certain iterated blowups of
geometrically ruled surfaces. In this paper, we show that the three notions of
parabolic polystability, K-polystability and existence of constant scalar
curvature K\"ahler metrics on the iterated blowup are equivalent, for certain
polarizations close to the boundary of the K\"ahler cone.


title: Warburg Effect due to Exposure to Different Types of Radiation

abstract:
  Cancer cells maintain a high level of aerobic glycolysis (the Warburg
effect), which is associated with their rapid proliferation. Many studies have
reported that the suppression of glycolysis and activation of oxidative
phosphorylation can repress the growth of cancer cells through regulation of
key regulators. Whether Warburg effect of cancer cells could be switched by
some other environmental stimulus? Herein, we report an interesting phenomenon
in which cells alternated between glycolysis and mitochondrial respiration
depending on the type of radiation they were exposed to. We observed enhanced
glycolysis and mitochondrial respiration in HeLa cells exposed to 2-Gy X-ray
and 2-Gy carbon ion radiation, respectively. This discovery may provide novel
insights for tumor therapy.


title:
Galois groups associated to generic Drinfeld modules and a conjecture of
  Abhyankar

abstract:
  Let $\phi$ be a rank $r$ Drinfeld $\BF_q[T]$-module determined by $\phi_T(X)
= TX+g_1X^q+...+g_{r-1}X^{q^{r-1}}+X^{q^r}$, where $g_1,...,g_{r-1}$ are
algebraically independent over $\BF_q(T)$. Let $N\in\BF_q[T]$ be a polynomial,
and $k/\BF_q$ an algebraic extension. We show that the Galois group of
$\phi_N(X)$ over $k(T,g_1,...,g_{r-1})$ is isomorphic to
$\GL_r(\BF_q[T]/N\BF_q[T])$, settling a conjecture of Abhyankar.


title:
A hybrid model for the evolution of galaxies and Active Galactic Nuclei
  in the infrared

abstract:
  [Abridged] We present a comprehensive investigation of the cosmological
evolution of the luminosity function (LF) of galaxies and active galactic
nuclei (AGN) in the infrared (IR). Based on the observed dichotomy in the ages
of stellar populations of early-type galaxies on one side and late-type
galaxies on the other, the model interprets the epoch-dependent LFs at z \geq
1.5 using a physical model for the evolution of proto-spheroidal galaxies and
of the associated AGNs, while IR galaxies at z<1.5 are interpreted as being
mostly late-type 'cold' (normal) and 'warm' (starburst) galaxies. As for
proto-spheroids, in addition to the epoch-dependent LFs of stellar and AGN
components separately, we have worked out the evolving LFs of these objects as
a whole (stellar plus AGN component). The model provides a physical explanation
for the observed positive evolution of both galaxies and AGNs up to z \simeq
2.5 and for the negative evolution at higher redshifts, for the sharp
transition from Euclidean to extremely steep counts at (sub-)mm wavelengths, as
well as the (sub-)mm counts of strongly lensed galaxies, that are hard to
account for by alternative, physical or phenomenological, approaches. The
evolution of late-type galaxies and of z<1.5 AGNs is described using a
parametric phenomenological approach. The modeled AGN contributions to the
counts and to the cosmic infrared background (CIB) are always subdominant with
maximal at mid-IR wavelengths. The model provides a good fit to the
multi-wavelength (from the mid-IR to millimeter waves) data on LFs at different
redshifts and on number counts (both global and per redshift slices). A
prediction of the present model is a systematic variation with wavelength of
the populations dominating the counts and the contributions to the CIB
intensity. The implied specific trend for cross-wavelength CIB power spectra is
found to be in good agreement with the data.


title: $\Lambda$CDM and Power-Law Expansion in Lyra's Geometry

abstract:
  We establish in a cosmological model based on Lyra's geometry a relationship
between a displacement vector field $ \phi_{\mu} $, the Hubble parameter and
the matter energy density $ \rho_{m} $ (with a constant equation of state $0
\le \omega_{m} < 1$) via an arbitrary function $\alpha(t)$. For a pressureless
matter ($ \omega_{m}=0 $) the effective equation of state $ \omega_{eff} $ is
completely determined by $ \alpha(t) $. We subsequently investigate and find
exact solutions in models yielding the $ \Lambda $CDM and a power-law
expansion.


title: Definitions of almost periodicity

abstract:
  Various versions of the classical definitions of (one- and twosided) almost
periodicity for functions on groups with values in a uniform space are
formulated and their equivalence is shown.


title: Suppression of Dielectronic Recombination Due to Finite Density Effects

abstract:
  We have developed a general model for determining density-dependent effective
dielectronic recombination (DR) rate coefficients in order to explore
finite-density effects on the ionization balance of plasmas. Our model consists
of multiplying by a suppression factor those highly-accurate total zero-density
DR rate coefficients which have been produced from state-of-the-art theoretical
calculations and which have been benchmarked by experiment. The suppression
factor is based-upon earlier detailed collision-radiative calculations which
were made for a wide range of ions at various densities and temperatures, but
used a simplified treatment of DR. A general suppression formula is then
developed as a function of isoelectronic sequence, charge, density, and
temperature. These density-dependent effective DR rate coefficients are then
used in the plasma simulation code Cloudy to compute ionization balance curves
for both collisionally ionized and photoionized plasmas at very low (ne = 1
cm^-3) and finite (ne=10^10 cm^-3) densities. We find that the denser case is
significantly more ionized due to suppression of DR, warranting further studies
of density effects on DR by detailed collisional-radiative calculations which
utilize state-of-the-art partial DR rate coefficients. This is expected to
impact the predictions of the ionization balance in denser cosmic gases such as
those found in nova and supernova shells, accretion disks, and the broad
emission line regions in active galactic nuclei.


title:
Tailoring the diameter of decorated CN nanotubes by temperature
  variations using HF-CVD

abstract:
  Patterned films of decorated nitrogenated carbon (C-N) nanotubes were
catalytically synthesised by hot filament chemical vapour deposition (HF-CVD)
in a nitrogen-methane-ammonia environment. The systematic study of a transition
between different kinds of C-N nanostructures as a function of the local
substrate temperature ranging from 700 up to 820C is presented. The morphology,
the diameter as well as the properties of the generated tubular structures
showed strong dependence on this parameter. By means of electron microscopy a
new type of decoration covering all tubular structures was observed. Buckled
lattice fringes revealed the disordered graphitic-like character of the hollow
C-N nanotubes. Raman spectroscopy confirmed a transition in the microscopic
order as a function of temperature. Furthermore field emission in vacuum was
studied and showed a spectacular correlation to the deposition temperature and
therefore the diameter of the C-N tubes. For arrays of tubes thinner than 50 nm
an onset field below 4 V/um was observed.


title: RXTE and SWIFT Observations of SWIFT J1729.9-3437

abstract:
  We analyze \emph{RXTE} and \emph{Swift} observations of SWIFT J1729.9$-$3437
after its outburst from 2010 July 20 to 2010 August 12. We calculate a spin
frequency and spin frequency derivative of $1.8734(8) \times 10^{-3}$ Hz and
$6.42(6) \times 10^{-12}$ Hz/s respectively from the quadratic fit of pulse
arrival times. The quadratic fit residuals fit well to a circular orbital model
with a period of $15.3(2)$ days and a mass function of about $1.3M_{\odot}$,
but they can also be explained by a torque noise strength of $6.8 \times
10^{-18}$ Hz sec$^{-2}$. Pulse profiles switches from double-peaked to
single-peaked as the source flux continues to decrease. We find that the pulse
shape generally shows no strong energy dependence. The hardness ratios reveal
that the source becomes softer with decreasing flux. We construct a single
spectrum from all the available RXTE and Swift observations. We find that
adding an \emph{Fe} line complex feature around 6.51 keV slightly improves the
spectral fit and that this feature is more likely to originate from the source
rather than the Galactic ridge. From the pulse phase spectral analysis, it is
shown that that photon index and folding energy of the high energy cut-off vary
with varying pulse phase.


title:
Thermal and dynamical properties of gas accreting onto a supermassive
  black hole in an AGN

abstract:
  (Abridged) We study stability of gas accretion in Active Galactic Nuclei. Our
grid based simulations cover a radial range from 0.1 to 200 pc. Here, as in
previous studies by our group, we include gas radiative cooling as well as
heating by a sub-Eddington X-ray source near the central supermassive black
hole of 10^8 M_{\odot}. Our theoretical estimates and simulations show that for
the X-ray luminosity L_X \sim 0.008 L_{Edd}, the gas is thermally and
convectivelly unstable within the computational domain. In the simulations, we
observe that very tiny fluctuations in an initially smooth, spherically
symmetric, accretion flow, grow first linearly and then non-linearly.
Consequently, an initially one-phase flow relatively quickly transitions into a
two-phase/cold-hot accretion flow. For L_X = 0.015 L_{Edd} or higher, the cold
clouds continue to accrete but in some regions of the hot phase, the gas starts
to move outward. For L_X < 0.015 L_{Edd}, the cold phase contribution to the
total mass accretion rate only moderately dominates over the hot phase
contribution. This result might have some consequences for cosmological
simulations of the so-called AGN feedback problem. Our simulations confirm the
previous results of Barai et al. (2012) who used smoothed particle hydrodynamic
simulations to tackle the same problem. However here, because we use a grid
based code to solve equations in 1-D and 2-D, we are able to follow the gas
dynamics at much higher spacial resolution and for longer time in comparison to
the 3-D SPH simulations. One of new features revealed by our simulations is
that the cold condensations in the accretion flow initially form long
filaments, but at the later times, those filaments may break into smaller
clouds advected outwards within the hot outflow. These simulations may serve as
an attractive model for the so-called Narrow Line Region in AGN.


title: Loop models with crossings

abstract:
  The universal behaviour of two-dimensional loop models can change
dramatically when loops are allowed to cross. We study models with crossings
both analytically and with extensive Monte Carlo simulations. Our main focus
(the 'completely packed loop model with crossings') is a simple generalisation
of well-known models which shows an interesting phase diagram with continuous
phase transitions of a new kind. These separate the unusual 'Goldstone' phase
observed previously from phases with short loops. Using mappings to Z_2 lattice
gauge theory, we show that the continuum description of the model is a replica
limit of the sigma model on real projective space (RP^{n-1}). This field theory
sustains Z_2 point defects which proliferate at the transition. In addition to
studying the new critical points, we characterise the universal properties of
the Goldstone phase in detail, comparing renormalisation group (RG)
calculations with numerical data on systems of linear size up to L=10^6 at loop
fugacity n=1. (Very large sizes are necessary because of the logarithmic form
of correlation functions and other observables.) The model is relevant to
polymers on the verge of collapse, and a particular point in parameter space
maps to self-avoiding trails at their \Theta-point; we use the RG treatment of
a perturbed sigma model to resolve some perplexing features in the previous
literature on trails. Finally, one of the phase transitions considered here is
a close analogue of those in disordered electronic systems --- specifically,
Anderson metal-insulator transitions --- and provides a simpler context in
which to study the properties of these poorly-understood (central-charge-zero)
critical points.


title:
Supersymmetric Descendants of Self-Adjointly Extended Quantum Mechanical
  Hamiltonians

abstract:
  We consider the descendants of self-adjointly extended Hamiltonians in
supersymmetric quantum mechanics on a half-line, on an interval, and on a
punctured line or interval. While there is a 4-parameter family of
self-adjointly extended Hamiltonians on a punctured line, only a 3-parameter
sub-family has supersymmetric descendants that are themselves self-adjoint. We
also address the self-adjointness of an operator related to the supercharge,
and point out that only a sub-class of its most general self-adjoint extensions
is physical. Besides a general characterization of self-adjoint extensions and
their supersymmetric descendants, we explicitly consider concrete examples,
including a particle in a box with general boundary conditions, with and
without an additional point interaction. We also discuss bulk-boundary
resonances and their manifestation in the supersymmetric descendant.


title: Null controllability of the 1D heat equation using flatness

abstract:
  We derive in a straightforward way the null controllability of a 1-D heat
equation with boundary control. We use the so-called {\em flatness approach},
which consists in parameterizing the solution and the control by the
derivatives of a "flat output". This provides an explicit control law achieving
the exact steering to zero. We also give accurate error estimates when the
various series involved are replaced by their partial sums, which is paramount
for an actual numerical scheme. Numerical experiments demonstrate the relevance
of the approach.


title:
Two charges on a plane in a magnetic field: hidden algebra, (particular)
  integrability, polynomial eigenfunctions

abstract:
  The quantum mechanics of two Coulomb charges on a plane $(e_1, m_1)$ and
$(e_2, m_2)$ subject to a constant magnetic field $B$ perpendicular to the
plane is considered. Four integrals of motion are explicitly indicated. It is
shown that for two physically-important particular cases, namely that of two
particles of equal Larmor frequencies, ${e_c} \propto
\frac{e_1}{m_1}-\frac{e_2}{m_2}=0$ (e.g. two electrons) and one of a neutral
system (e.g. the electron - positron pair, Hydrogen atom) at rest (the
center-of-mass momentum is zero) some outstanding properties occur. They are
the most visible in double polar coordinates in CMS $(R, \phi)$ and relative
$(\rho, \varphi)$ coordinate systems: (i) eigenfunctions are factorizable, all
factors except one with the explicit $\rho$-dependence are found analytically,
they have definite relative angular momentum, (ii) dynamics in $\rho$-direction
is the same for both systems, it corresponds to a funnel-type potential and it
has hidden $sl(2)$ algebra; at some discrete values of dimensionless magnetic
fields $b \leq 1$, (iii) particular integral(s) occur, (iv) the hidden $sl(2)$
algebra emerges in finite-dimensional representation, thus, the system becomes
{\it quasi-exactly-solvable} and (v) a finite number of polynomial
eigenfunctions in $\rho$ appear. Nine families of eigenfunctions are presented
explicitly.

categories: math-ph cond-mat.str-el math.MP nlin.SI quant-ph


title: CTA: the future of ground-based gamma-ray astrophysics

abstract:
  Very high energy (VHE; E > 100 GeV) gamma-rays provide a unique probe into
the non-thermal processes in the universe. The ground-based Imaging Air
Cherenkov telescopes (IACTs) for detecting VHE gamma-rays have been perfected,
so a relatively fast and inexpensive assembly of IACTs is now possible. Next
generation instruments will have a sensitivity about 10 times better than
current facilities, and will extend the accessible gamma-ray bandwidth at both
energy ends (down to 30 GeV and up to 300 TeV) with improved angular and energy
resolutions. Some key physics drivers, that are discussed here, suit specific
features of the upcoming IACT facility, the Cherenkov Telescope Array (CTA).
The resulting technical solutions chosen for CTA, and the current status of the
project, are also outlined.


title: On representation varieties of 3-manifold groups

abstract:
  We prove universality theorems ("Murphy's Laws") for representation schemes
of fundamental groups of closed 3-dimensional manifolds. We show that germs of
SL(2,C)-representation schemes of such groups are essentially the same as germs
of schemes of over rational numbers.


title: The MEG detector for ${\mu}+\to e+{\gamma}$ decay search

abstract:
  The MEG (Mu to Electron Gamma) experiment has been running at the Paul
Scherrer Institut (PSI), Switzerland since 2008 to search for the decay \meg\
by using one of the most intense continuous $\mu^+$ beams in the world. This
paper presents the MEG components: the positron spectrometer, including a thin
target, a superconducting magnet, a set of drift chambers for measuring the
muon decay vertex and the positron momentum, a timing counter for measuring the
positron time, and a liquid xenon detector for measuring the photon energy,
position and time. The trigger system, the read-out electronics and the data
acquisition system are also presented in detail. The paper is completed with a
description of the equipment and techniques developed for the calibration in
time and energy and the simulation of the whole apparatus.


title: Effective freeness and very ampleness in positive characteristic

abstract:
  In this paper, we establish a basepoint free theorem of Angehrn-Siu type in
positive characteristic. Moreover, we also give an effective bound for very
ampleness in arbitrary characteristic.


title:
Bracket map for Heisenberg group and the characterization of cyclic
  subspaces

abstract:
  The bracket map was originally considered for locally compact abelian groups.
In this work we extend the study of bracket maps to the noncommutative setting,
providing characterizations of bases and frames for cyclic subspaces of the
Heisenberg group. We also indicate how to generalize these results to a class
of non-abelian nilpotent Lie groups whose irreducible representations are
square integrable modulo the center.


title: Almost complex circle actions with few fixed points

abstract:
  We show that almost complex circle actions with exactly three fixed points do
not exist in dimension 8 and present an infinite series of 6-dimensional
manifolds possessing an almost complex circle action with exactly two fixed
points.


title:
On the splitting of the exact sequence relating the wild and tame
  kernels

abstract:
  Let k be a number field. For an odd prime p and an integer i>1, the i-th
\'etale wild kernel is contained in the second cohomology group of o'_k with
coefficients in Zp(i), where o'_k is the ring of p-integers of k. Using Iwasawa
theory, we give conditions for this inclusion to split. In particular we relate
this splitting problem to the triviality of two invariants, namely the
asymptotic kernels of the Galois descent and codescent for class groups along
the cyclotomic tower of k. We illustrate our results in both split and
non-split cases for quadratic number fields.


title:
Microwave spectroscopy of Josephson junctions in topological
  superconductors

abstract:
  We consider microwave spectroscopy of Josephon junctions composed of
hybridized Majorana states in topological 1-D superconductors. We point out how
spectroscopic features of the junction appear in the current phase relation
under microwave irradiation. Moreover, we discuss a way to directly probe the
nonequilibrium state associated with the 4{\pi} periodic Josephson effect. In
particular, we show how the microwave driving can be used to switch from a
4{\pi} to a 2{\pi} Shapiro step in the current voltage relation.


title:
Pin(2)-equivariant Seiberg-Witten Floer homology and the Triangulation
  Conjecture

abstract:
  We define Pin(2)-equivariant Seiberg-Witten Floer homology for rational
homology 3-spheres equipped with a spin structure. The analogue of Froyshov's
correction term in this setting is an integer-valued invariant of homology
cobordism whose mod 2 reduction is the Rokhlin invariant. As an application, we
show that there are no homology 3-spheres Y of Rokhlin invariant one such that
Y # Y bounds an acyclic smooth 4-manifold. By previous work of Galewski-Stern
and Matumoto, this implies the existence of non-triangulable high-dimensional
manifolds.


title:
Fluctuation conductivity of disordered superconductors in magnetic
  fields

abstract:
  We calculate fluctuation corrections to the longitudinal conductivity of
disordered superconductors subject to an external magnetic field. We derive
analytic expressions that are valid in the entire metallic part of the
temperature-magnetic field phase diagram as long as the effect of the magnetic
field on the spin degrees of freedom of the electrons may be neglected. Our
calculations are based on a kinetic equation approach. For the special case of
superconducting films and wires in parallel magnetic fields we perform a
detailed comparison with results that were previously obtained with
diagrammatic perturbation theory in the imaginary time formalism. As an
application, we study the fluctuation conductivity of films in tilted magnetic
fields with a special focus on the low-temperature regime. We present a
detailed discussion of the phenomenon of the non-monotonous magnetoresistance
and find that it displays a pronounced dependence on the tilting angle.


title:
Evidence for the photospheric excitation of incompressible chromospheric
  waves

abstract:
  Observing the excitation mechanisms of incompressible transverse waves is
vital for determining how energy propagates through the lower solar atmosphere.
We aim to show the connection between convectively driven photospheric flows
and incompressible chromospheric waves. The observations presented here show
the propagation of incompressible motion through the quiet lower solar
atmosphere, from the photosphere to the chromosphere. We determine photospheric
flow vectors to search for signatures of vortex motion and compare results to
{photospheric flows present in} convective simulations. Further, we search for
the chromospheric response to vortex motions. Evidence is presented that
suggests incompressible waves can be excited by the vortex motions of a strong
magnetic flux concentration in the photosphere. A chromospheric counterpart to
the photospheric vortex motion is also observed, presenting itself as a
quasi-periodic torsional motion. Fine-scale, fibril structures that emanate
from the chromospheric counterpart support transverse waves that are driven by
the observed torsional motion. A new technique for obtaining details of
transverse waves from time-distance diagrams is presented and the properties of
transverse waves (e.g., amplitudes and periods) excited by the chromospheric
torsional motion are measured.


title:
Burgers-like equation for spontaneous breakdown of the chiral symmetry
  in QCD

abstract:
  We link the spontaneous breakdown of chiral symmetry in Euclidean QCD to the
collision of spectral shock waves in the vicinity of zero eigenvalue of Dirac
operator. The mechanism, originating from complex Burger's-like equation for
viscid, pressureless, one-dimensional flow of eigenvalues, is similar to
recently observed weak-strong coupling phase transition in large $N_c$
Yang-Mills theory. The spectral viscosity is proportional to the inverse of the
size of the random matrix that replaces the Dirac operator in the universal
(ergodic) regime. We obtain the exact scaling function and critical exponents
of the chiral phase transition for the averaged characteristic polynomial for
$N_c \ge3$ QCD. We reinterpret our results in terms of known properties of
chiral random matrix models and lattice data.


title:
Control of a Novel Chaotic Fractional Order System Using a State
  Feedback Technique

abstract:
  We consider a new fractional order chaotic system displaying an interesting
behavior. A necessary condition for the system to remain chaotic is derived. It
is found that chaos exists in the system with order less than three. Using the
Routh-Hurwitz and the Matignon stability criteria, we analyze the novel chaotic
fractional order system and propose a control methodology that is better than
the nonlinear counterparts available in the literature, in the sense of
simplicity of implementation and analysis. A scalar control input that excites
only one of the states is proposed, and sufficient conditions for the
controller gain to stabilize the unstable equilibrium points derived. Numerical
simulations confirm the theoretical analysis.


title: Metal-insulator transition in three-dimensional semiconductors

abstract:
  We use a random gap model to describe a metal-insulator transition in
three-dimensional semiconductors due to doping and find a conventional phase
transition, where the effective scattering rate is the order parameter.
Spontaneous symmetry breaking results in metallic behavior, whereas the
insulating regime is characterized by the absence of spontaneous symmetry
breaking. The transition is continuous for the average conductivity with
critical exponent equal to 1. Away from the critical point the exponent is
roughly 0.6, which may explain experimental observations of a crossover of the
exponent from 1 to 0.5 by going away from the critical point.


title: Global Flow of Glasma in High Energy Nuclear Collisions

abstract:
  We discuss the energy flow of the classical gluon fields created in
collisions of heavy nuclei at collider energies. We show how the Yang-Mills
analoga of Faraday's Law and Gauss' Law predict the initial gluon flux tubes to
expand or bend. The resulting transverse and longitudinal structure of the
Poynting vector field has a rich phenomenology. Besides the well known radial
and elliptic flow in transverse direction, classical quantum chromodynamics
predicts a rapidity-odd transverse flow that tilts the fireball for non-central
collisions, and it implies a characteristic flow pattern for collisions of
non-symmetric systems $A+B$. The rapidity-odd transverse flow translates into a
directed particle flow $v_1$ which has been observed at RHIC and LHC. The
global flow fields in heavy ion collisions could be a powerful check for the
validity of classical Yang-Mill dynamics in high energy collisions.


title:
Particle-hole condensates of higher angular momentum in hexagonal
  systems

abstract:
  Hexagonal lattice systems (e.g. triangular, honeycomb, kagome) possess a
multidimensional irreducible representation corresponding to $d_{x^2-y^2}$ and
$d_{xy}$ symmetry. Consequently, various unconventional phases that combine
these $d$-wave representations can occur, and in so doing may break
time-reversal and spin rotation symmetries. We show that hexagonal lattice
systems with extended repulsive interactions can exhibit instabilities in the
particle-hole channel to phases with either $d_{x^2-y^2}+d_{xy}$ or $d+id$
symmetry. When lattice translational symmetry is preserved, the phase
corresponds to nematic order in the spin-channel with broken time-reversal
symmetry, known as the $\beta$ phase. On the other hand, lattice translation
symmetry can be broken, resulting in various $d_{x^2-y^2}+d_{xy}$ density wave
orders. In the weak-coupling limit, when the Fermi surface lies close to a van
Hove singularity, instabilities of both types are obtained in a controlled
fashion.


title: On the class of dominant and subordinate products

abstract:
  In this paper we provide proofs of two new theorems that provide a broad
class of partition inequalities and that illustrate a na\"ive version of
Andrews' anti-telescoping technique quite well. These new theorems also put to
rest any notion that including parts of size 1 is somehow necessary in order to
have a valid irreducible partition inequality. In addition, we prove (as a
lemma to one of the theorems) a rather nontrivial class of rational functions
of three variables has entirely nonnegative power series coefficients.


title: F_p is locally like C

abstract:
  Vu, Wood and Wood showed that any finite set S in a characteristic zero
integral domain can be mapped to F_p, for infinitely many primes p, while
preserving finitely many algebraic incidences of S. In this note we show that
the converse essentially holds, namely any small subset of F_p can be mapped to
some finite algebraic extension of Q, while preserving bounded algebraic
relations. This answers a question of Vu, Wood and Wood. We give several
applications, in particular we show that for small subsets of F_p, the
Szemer\'edi-Trotter theorem holds with optimal exponent 4/3, and we improve the
previously best-known sum-product estimate in F_p. We also give an application
to an old question of R\'enyi. The proof of the main result is an application
of elimination theory and is similar in spirit with the proof of the
quantitative Hilbert Nullstellensatz.


title: The Multidimensional Study of Viral Campaigns as Branching Processes

abstract:
  Viral campaigns on the Internet may follow variety of models, depending on
the content, incentives, personal attitudes of sender and recipient to the
content and other factors. Due to the fact that the knowledge of the campaign
specifics is essential for the campaign managers, researchers are constantly
evaluating models and real-world data. The goal of this article is to present
the new knowledge obtained from studying two viral campaigns that took place in
a virtual world which followed the branching process. The results show that it
is possible to reduce the time needed to estimate the model parameters of the
campaign and, moreover, some important aspects of time-generations relationship
are presented.


title: Studying Paths of Participation in Viral Diffusion Process

abstract:
  Authors propose a conceptual model of participation in viral diffusion
process composed of four stages: awareness, infection, engagement and action.
To verify the model it has been applied and studied in the virtual social chat
environment settings. The study investigates the behavioral paths of actions
that reflect the stages of participation in the diffusion and presents
shortcuts, that lead to the final action, i.e. the attendance in a virtual
event. The results show that the participation in each stage of the process
increases the probability of reaching the final action. Nevertheless, the
majority of users involved in the virtual event did not go through each stage
of the process but followed the shortcuts. That suggests that the viral
diffusion process is not necessarily a linear sequence of human actions but
rather a dynamic system.


title: Modeling Hydrogen-Rich Wolf-Rayet Stars in M33

abstract:
  We present the results of a spectral variability study of two very luminous
stars in the M33 galaxy -- LBV V532 and late WN star (possibly, dormant LBV)
FSZ35. We studied spectral variability of V532, derived its atmosphere
parameters and showed that the bolometric luminosity varies between the two
states by a factor of $\sim$1.5. Using the non-LTE radiative transfer code
CMFGEN, we determined wind parameters for both objects. Since both stars are
located at distances of about 100 pc from the nearest association, we supposed
that they may be massive runaway stars with velocities of the order 100 km/s.


title: Flaring gamma-ray AGNs seen with the FERMI LAT

abstract:
  In the first 3.5 years of operations the Fermi LAT detected several sources
with daily fluxes brighter than F(E>100MeV) > 10^{-6} ph/cm^2/s, the threshold
set by the Fermi Collaboration for issuing an Astronomer Telegram. We focus the
attention on these flaring sources, most of which are blazars, known to be
extremely variable over the whole electromagnetic spectrum, from radio to
gamma-ray energies and we investigate the properties of the selected sample
comparing them to the general characteristics of the Fermi catalog sources.


title: An Arzel\`a-Ascoli theorem for the Hausdorff measure of noncompactness

abstract:
  We generalize the Arzel\`a-Ascoli theorem in the space of continuous maps on
a compact interval with values in Euclidean N-space by providing a quantitative
link between the Hausdorff measure of noncompactness in this space and a
natural measure of non-uniform equicontinuity. The proof hinges upon a
classical result of Jung's on the Chebyshev radius.


title:
Negative Effects of Incentivised Viral Campaigns for Activity in Social
  Networks

abstract:
  Viral campaigns are crucial methods for word-of-mouth marketing in social
communities. The goal of these campaigns is to encourage people for activity.
The problem of incentivised and non-incentivised campaigns is studied in the
paper. Based on the data collected within the real social networking site both
approaches were compared. The experimental results revealed that a highly
motivated campaign not necessarily provides better results due to overlapping
effect. Additional studies have shown that the behaviour of individual
community members in the campaign based on their service profile can be
predicted but the classification accuracy may be limited.


title: Types of tightness in spaces with unconditional basis

abstract:
  We present a reflexive Banach space with an unconditional basis which is
quasi-minimal and tight by range, i.e. of type (4) in Ferenczi-Rosendal list
within the framework of Gowers' classification program of Banach spaces, but
contrary to the recently constructed space of type (4) also tight with
constants, thus essentially extending the list of known examples in Gowers
classification program. The space is defined on the base on a boundedly
modified mixed Tsirelson space with use of a special coding function.


title:
Electric Dipole Moments of Nucleons, Nuclei, and Atoms: The Standard
  Model and Beyond

abstract:
  Searches for the permanent electric dipole moments (EDMs) of molecules,
atoms, nucleons and nuclei provide powerful probes of CP violation both within
and beyond the Standard Model (BSM). The interpretation of experimental EDM
limits requires careful delineation of physics at a wide range of distance
scales, from the long-range atomic and molecular scales to the short-distance
dynamics of physics at or beyond the Fermi scale. In this review, we provide a
framework for disentangling contributions from physics at these disparate
scales, building out from the set of dimension four and six effective operators
that embody CP violation at the Fermi scale. We survey existing computations of
hadronic and nuclear matrix elements associated with Fermi-scale CP violation
in systems of experimental interest, and quantify the present level of
theoretical uncertainty in these calculations. Using representative BSM
scenarios of current interest, we illustrate how the interplay of physics at
various scales generates EDMs at a potentially observable level.


title:
Towards Anisotropy-Free and Non-Singular Bounce Cosmology with
  Scale-invariant Perturbations

abstract:
  We investigate non-singular bounce realizations in the framework of
ghost-free generalized Galileon cosmology, which furthermore can be free of the
anisotropy problem. Considering an Ekpyrotic-like potential we can obtain a
total Equation-of-State (EoS) larger than one in the contracting phase, which
is necessary for the evolution to be stable against small anisotropic
fluctuations. Since such a large EoS forbids the Galileon field to generate the
desired form of perturbations, we additionally introduce the curvaton field
which can in general produce the observed nearly scale-invariant spectrum. In
particular, we provide approximate analytical and exact semi-analytical
expressions under which the bouncing scenario is consistent with observations.
Finally, the combined Galileon-curvaton system is free of the Big-Rip after the
bounce.


title: Stability of frozen waves in the Modified Cahn--Hilliard model

abstract:
  We examine the existence and stability of frozen waves in diblock copolymers
with local conservation of the order parameter, which are described by the
modified Cahn--Hilliard model. It is shown that a range of stable waves exists
and each can emerge from a `general' initial condition (not only the one with
the lowest density of free energy). We discuss the implications of these
results for the use of block copolymers in templating nanostructures.


title:
Halpha3: an Halpha imaging survey of HI selected galaxies from ALFALFA.
  III. Nurture shapes up the Hubble sequence in the Great Wall

abstract:
  We present the analysis of Halpha3, an Halpha imaging survey of galaxies
selected from the HI ALFALFA Survey in the Coma Supercluster. By using the
Halpha line as a tracer of the "instantaneous" star formation, complemented
with optical colors from SDSS we explore the hypothesis that a morphological
sequence of galaxies of progressively earlier type, lower gas-content exists in
the neighborhood of the Coma cluster, with specific star formation activity
decreasing with increasing local galaxy density and velocity dispersion. In the
dwarf regime (8.5<\log(M*)< 9.5) we identify a 4-step sequence of galaxies with
progressively redder colors, i.e. of decreasing specific star formation, from
(1) HI-rich Late-Type Galaxies belonging to the blue-cloud exhibiting extended
plus nuclear star formation, (2) HI-poor LTGs with nuclear star formation only,
(3) HI-poor galaxies with no star formation either extended or nuclear, but
with nuclear Post-Star-Burst signature,(4) Early-type Galaxies in the
red-sequence, with no gas or star formation on all scales. Along this sequence
the quenching of the star formation proceeds radially outside-in. The
progression toward redder colors found along this "morphological" (gas content)
sequence is comparable to the one obtained increasing the local galaxy density,
from the cosmic filaments (1,2), to the rich clusters (2,3,4). In the dwarf
regime we find evidence for evolution of HI-rich LTGs into ETGs, passing
through HI-poor and PSB galaxies, driven by the environment. We identify
ram-pressure as the mechanism most likely responsible for this transformation.
We conclude that infall of low-mass galaxies has proceeded for the last 7.5 Gyr
building up the Coma cluster at a rate of approximately 100 galaxies per Gyr.


title: Hadamard-Perron theorems and effective hyperbolicity

abstract:
  We prove several new versions of the Hadamard-Perron Theorem, which relates
infinitesimal dynamics to local dynamics for a sequence of local
diffeomorphisms, and in particular establishes the existence of local stable
and unstable manifolds. Our results imply the classical Hadamard-Perron Theorem
in both its uniform and non-uniform versions, but also apply much more
generally. We introduce a notion of "effective hyperbolicity" and show that if
the rate of effective hyperbolicity is asymptotically positive, then the local
manifolds are well-behaved with positive asymptotic frequency. By applying
effective hyperbolicity to finite orbit segments, we prove a closing lemma
whose conditions can be verified with a finite amount of information.


title: Quasidiagonal Representations of Nilpotent Groups

abstract:
  We show that every unitary representation of a solvable discrete virtually
nilpotent group G is quasidiagonal. Roughly speaking, this says that every
unitary representation of G approximately decomposes as a direct sum of finite
dimensional approximate representations. In operator algebraic terms we show
that C*(G) is strongly quasidiagonal.


title: Dynamical Localization of Bose-Einstein condensate in Optomechanics

abstract:
  We explain dynamical localization of Bose-Einstein condensate (BEC) in
optomechanics both in position and in momentum space. The experimentally
realizable optomechanical system is a Fabry-Perot cavity with one moving end
mirror and driven by single mode standing field. In our study we analyze
variations in modulation strength and effective Plank's constant. Keeping in
view present day experimental advances we provide set of parameters to observe
the phenomenon in laboratory.


title:
Predictive Correlation Screening: Application to Two-stage Predictor
  Design in High Dimension

abstract:
  We introduce a new approach to variable selection, called Predictive
Correlation Screening, for predictor design. Predictive Correlation Screening
(PCS) implements false positive control on the selected variables, is well
suited to small sample sizes, and is scalable to high dimensions. We establish
asymptotic bounds for Familywise Error Rate (FWER), and resultant mean square
error of a linear predictor on the selected variables. We apply Predictive
Correlation Screening to the following two-stage predictor design problem. An
experimenter wants to learn a multivariate predictor of gene expressions based
on successive biological samples assayed on mRNA arrays. She assays the whole
genome on a few samples and from these assays she selects a small number of
variables using Predictive Correlation Screening. To reduce assay cost, she
subsequently assays only the selected variables on the remaining samples, to
learn the predictor coefficients. We show superiority of Predictive Correlation
Screening relative to LASSO and correlation learning (sometimes popularly
referred to in the literature as marginal regression or simple thresholding) in
terms of performance and computational complexity.


title:
Conditions for Robustness of Polar Codes in the Presence of Channel
  Mismatch

abstract:
  A challenging problem related to the design of polar codes is "robustness
against channel parameter variations" as stated in Ar{\i}kan's original work.
In this paper, we describe how the problem of robust polar code design can be
viewed as a mismatch decoding problem. We propose conditions which ensure a
polar encoder/decoder designed for a mismatched B-DMC can be used to
communicate reliably. In particular, the analysis shows that the original polar
code construction method is robust over the class of binary symmetric channels.


title:
Parsimonious Description of Generalized Gibbs Measures : Decimation of
  the 2d-Ising Model

abstract:
  In this paper, we detail and complete the existing characterizations of the
decimation of the Ising model on $\Z^2$ in the generalized Gibbs context. We
first recall a few features of the Dobrushin program of restoration of
Gibbsianness and present the construction of global specifications consistent
with the extremal decimated measures. We use them to consider these
renormalized measures as almost Gibbsian measures and to precise its convex set
of DLR measures. We also recall the weakly Gibbsian description and complete it
using a potential that admits a quenched correlation decay, i.e. a well-defined
configuration-dependent length beyond which this potential decays
exponentially. We use these results to incorporate these decimated measures in
the new framework of parsimonious random fields that has been recently
developed to investigate probability aspects related to neurosciences.


title: Zen and the Art of Space-Time Manufacturing

abstract:
  We present a general discussion about the so-called emergent properties and
discuss whether space-time and gravity can be regarded as emergent features of
underlying more fundamental structures. Finally, we discuss some ideas about
the multiverse, and speculate on how our universe might arise from the
multiverse.


title: The ground state energy of a polaron in a strong magnetic field

abstract:
  We show that the ground state of a polaron in a homogeneous magnetic field
$B$ and its energy are described by an effective one-dimensional minimization
problem in the limit $B\to\infty$. This holds both in the linear Fr\"ohlich and
in the non-linear Pekar model and makes rigorous an argument of Kochetov,
Leschke and Smondyrev.


title: A tip-based source of femtosecond electron pulses at 30keV

abstract:
  We present a nano-scale photoelectron source, optimized towards ultrashort
pulse durations and well-suited for time-resolved diffraction experiments. A
tungsten tip, mounted in a suppressor-extractor electrode configuration, allows
the generation of 30 keV electron pulses with an estimated pulse duration of 37
fs at the gun exit. We infer the pulse duration from particle tracking
simulations, which are in excellent agreement with experimental measurements of
the electron-optical properties of the source. We furthermore demonstrate
femtosecond laser-triggered operation. Besides the short electron pulse
duration, a tip-based source is expected to feature a large transverse
coherence as well as a nanometric emittance.


title: Gamma Rays from Bino-like Dark Matter in the MSSM

abstract:
  We consider regions of the parameter space of the Minimal Supersymmetric
Standard Model (MSSM) with bino-like neutralino dark matter in which a large
fraction of the total dark matter annihilation cross section in the present era
arises from annihilation to final states with monoenergetic photons. The region
of interest is characterized by light sleptons and heavy squarks. We find that
it is possible for the branching fraction to final states with monoenergetic
photons to be comparable to that for continuum photons, but in those cases the
total cross section will be so small that it is unlikely to be observable. For
models where dark matter annihilation may be observable in the present era, the
branching fraction to final states with monoenergetic photons is O(1-10%).


title: Non-embeddable Real Algebraic Hypersurfaces

abstract:
  We study various classes of real hypersurfaces that are not embeddable into
more special hypersurfaces in higher dimension, such as spheres, real algebraic
compact strongly pseudoconvex hypersurfaces or compact pseudoconvex
hypersurfaces of finite type. We conclude by stating some open problems.


title: Asymptotic Normality of Random Sums of m-dependent Random Variables

abstract:
  We prove a central limit theorem for random sums of the form
$\sum_{i=1}^{N_n} X_i$, where $\{X_i\}_{i \geq 1}$ is a stationary
$m-$dependent process and $N_n$ is a random index independent of
$\{X_i\}_{i\geq 1}$. Our proof is a generalization of Chen and Shao's result
for i.i.d. case and consequently we recover their result. Also a variation of a
recent result of Shang on $m-$dependent sequences is obtained as a corollary.
Examples on moving averages and descent processes are provided, and possible
applications on non-parametric statistics are discussed.


title: Descent-Inversion Statistics in Riffle Shuffles

abstract:
  This paper studies statistics of riffle shuffles by relating them to random
word statistics with the use of inverse shuffles. Asymptotic normality of the
number of descents and inversions in riffle shuffles with convergence rates of
order $1/\sqrt{n}$ in the Kolmogorov distance are proven. Results are also
given about the lengths of the longest alternating subsequences of random
permutations resulting from riffle shuffles. A sketch of how the theory of
multisets can be useful for statistics of a variation of top $m$ to random
shuffles is presented.


title:
Information Relaxation and Dual Formulation of Controlled Markov
  Diffusions

abstract:
  Information relaxation and duality in Markov decision processes have been
studied recently by several researchers with the goal to derive dual bounds on
the value function. In this paper we extend this dual formulation to controlled
Markov diffusions: in a similar way we relax the constraint that the decision
should be made based on the current information and impose penalty to punish
the access to the information in advance. We establish the weak duality, strong
duality and complementary slackness results in a parallel way as those in
Markov decision processes. We explore the structure of the optimal penalties
and expose the connection between Markov decision processes and controlled
Markov diffusions. We demonstrate the use of the dual representation for
controlled Markov diffusions in a classic dynamic portfolio choice problem. We
evaluate the lower bounds on the expected utility by Monte Carlo simulation
under a sub-optimal policy, and we propose a new class of penalties to derive
upper bounds with little extra computation. The small gaps between the lower
bounds and upper bounds indicate that the available policy is near optimal as
well as the effectiveness of our proposed penalty in the dual method.


title:
Maximin Analysis of Message Passing Algorithms for Recovering Block
  Sparse Signals

abstract:
  We consider the problem of recovering a block (or group) sparse signal from
an underdetermined set of random linear measurements, which appear in
compressed sensing applications such as radar and imaging. Recent results of
Donoho, Johnstone, and Montanari have shown that approximate message passing
(AMP) in combination with Stein's shrinkage outperforms group LASSO for large
block sizes. In this paper, we prove that, for a fixed block size and in the
strong undersampling regime (i.e., having very few measurements compared to the
ambient dimension), AMP cannot improve upon group LASSO, thereby complementing
the results of Donoho et al.


title: Electronic Thermal Conductivity Measurements in Intrinsic Graphene

abstract:
  The electronic thermal conductivity of graphene and 2D Dirac materials is of
fundamental interest and can play an important role in the performance of
nano-scale devices. We report the electronic thermal conductivity, $K_{e}$, in
suspended graphene in the nearly intrinsic regime over a temperature range of
20 to 300 K. We present a method to extract $K_{e}$ using two-point DC electron
transport at low bias voltages, where the electron and lattice temperatures are
decoupled. We find $K_e$ ranging from 0.5 to 11 W/m.K over the studied
temperature range. The data are consistent with a model in which heat is
carried by quasiparticles with the same mean free-path and velocity as
graphene's charge carriers.


title: Electrostatic Graphene Loudspeaker

abstract:
  Graphene has extremely low mass density and high mechanical strength, key
qualities for efficient wide-frequency-response electrostatic audio speaker
design. Low mass ensures good high frequency response, while high strength
allows for relatively large free-standing diaphragms necessary for effective
low frequency response. Here we report on construction and testing of a
miniaturized graphene-based electrostatic audio transducer. The
speaker/earphone is straightforward in design and operation and has excellent
frequency response across the entire audio frequency range (20HZ - 20kHz), with
performance matching or surpassing commercially available audio earphones.


title: Stationary scalar configurations around extremal charged black holes

abstract:
  We consider the minimally coupled Klein-Gordon equation for a charged,
massive scalar field in the non-extremal Reissner-Nordstr\"om background.
Performing a frequency domain analysis, using a continued fraction method, we
compute the frequencies \omega for quasi-bound states. We observe that, as the
extremal limit for both the background and the field is approached, the real
part of the quasi-bound states frequencies $\mathcal{R}(\omega)$ tends to the
mass of the field and the imaginary part $\mathcal{I}(\omega)$ tends to zero,
for any angular momentum quantum number $\ell$. The limiting frequencies in
this double extremal limit are shown to correspond to a distribution of
extremal scalar particles, at stationary positions, in no-force equilibrium
configurations with the background. Thus, generically, these stationary scalar
configurations are regular at the event horizon. If, on the other hand, the
distribution contains scalar particles at the horizon, the configuration
becomes irregular therein, in agreement with no hair theorems for the
corresponding Einstein-Maxwell-scalar field system.