title:
Reanalysis of the $e^+ e^- \to (D^* \bar D^*)^{\pm} \pi^{\mp}$ reaction
  and the claim for the $Z_c (4025)$ resonance

abstract:
  In this paper we study the reaction $e^+ e^- \to (D^* \bar D^*)^{\pm}
\pi^{\mp}$ in which the BESIII collaboration has claimed the existence of a
$1^+$ resonance, named $Z_c(4025)$, in the $D^*\bar D^*$ invariant mass
spectrum with a mass around 4026 MeV and width close to 26 MeV. We determine
the $D^*\bar D^*$ invariant mass distribution and find that although the
explanation considered by the BESIII collaboration is plausible, there are
others which are equally possible, like a $2^+$ resonance or a bound state.
Even more, we find that the data can be explained without the existence of a
resonance/bound state. In view of the different possible interpretations found
for the BESIII data, we try to devise a strategy which could help in
identifying the origin of the signal reported by the BESIII collaboration. For
this, we study the dependence of the $D^*\bar D^*$ spectrum considering the
different options as a function of the total center of mass energy. We arrive
to the conclusion that increasing the center of mass energy from 4.26 GeV to
4.6 GeV can be useful to distinguish between a resonance, a bound state or just
a pure background as being responsible for the signal found. This information
should be useful for future experiments.


title:
Consistency of Probability Measure Quantization by Means of Power
  Repulsion-Attraction Potentials

abstract:
  This paper is concerned with the study of the consistency of a variational
method for probability measure quantization, deterministically realized by
means of a minimizing principle, balancing power repulsion and attraction
potentials. The proof of consistency is based on the construction of a target
energy functional whose unique minimizer is actually the given probability
measure \omega to be quantized. Then we show that the discrete functionals,
defining the discrete quantizers as their minimizers, actually \Gamma-converge
to the target energy with respect to the narrow topology on the space of
probability measures. A key ingredient is the reformulation of the target
functional by means of a Fourier representation, which extends the
characterization of conditionally positive semi-definite functions from points
in generic position to probability measures. As a byproduct of the Fourier
representation, we also obtain compactness of sublevels of the target energy in
terms of uniform moment bounds, which already found applications in the
asymptotic analysis of corresponding gradient flows. To model situations where
the given probability is affected by noise, we additionally consider a modified
energy, with the addition of a regularizing total variation term and we
investigate again its point mass approximations in terms of \Gamma-convergence.
We show that such a discrete measure representation of the total variation can
be interpreted as an additional nonlinear potential, repulsive at a short
range, attractive at a medium range, and at a long range not having effect,
promoting a uniform distribution of the point masses.


title: Multi-boson spectrum of the SU(2)-Higgs model

abstract:
  Lattice simulations are used to compute the spectrum of energy levels for all
angular momentum and parity quantum numbers in the SU(2)-Higgs model, with
parameters chosen to match experimental data from the Higgs-W boson sector of
the standard model. Creation operators are constructed for all lattice
irreducible representations, and a correlation matrix is formed from which the
spectrum is extracted using a variational analysis. Many multi-boson states are
observed and careful analysis reveals that all are consistent with
weakly-interacting Higgs and W bosons.


title: Computational quest for Kaos-land

abstract:
  Using bi-parametric sweeping based on symbolic representation we reveal
self-similar fractal structures induced by hetero- and homoclinic bifurcations
of saddle singularities in the parameter space of two systems with
deterministic chaos. We start with the system which displays several homoclinic
bifurcations of higher codimension: resonant saddle, orbit-flip and inclination
switch that all give rise to the onset of the Lorenz-type attractor in
$Z_2$-systems with the homoclinic butterfly. The second system is the classic
Lorenz model of 1963, originated in fluid mechanics.


title: Antiparticle creation in tunneling

abstract:
  We study particle interaction with a Dirac step potential. In the standard
Klein energy zone, the hypothesis of Klein pair production predicts the
existence of free/oscillatory antiparticles. In this paper, we discuss the
tunneling energy zone characterized by evanescent wave functions in the
classically forbidden region. We ask the question of the nature, particle or
antiparticle, of the densities within the classically forbidden region. The
answer to this question is relevant to the correct form of the reflection
coefficient.


title:
Finite size scaling and the effect of the gauge coupling in 12 flavor
  systems

abstract:
  Finite size scaling is a powerful tool to study the critical properties of
systems governed by one relevant operator, assuming all irrelevant operators
have scaling dimensions much smaller then zero. This condition is likely not
satisfied in many-fermion conformal systems where perturbation theory predicts
a nearly-marginal irrelevant gauge coupling. In this work we carry out a new
investigation of SU(3) lattice gauge theory with 12 fundamental flavors.
Analyzing data at many different gauge couplings, our preliminary results
indicate that a finite size scaling analysis that takes into account the effect
of a nearly-marginal gauge coupling can resolve many of the inconsistencies
observed previously in this system, leading to results consistent with
conformal infrared dynamics and predicting a mass scaling anomalous around
$\gamma_m=0.25$.


title:
Toward robust phase-locking in Melibe swim central pattern generator
  models

abstract:
  Small groups of interneurons, abbreviated by CPG for central pattern
generators, are arranged into neural networks to generate a variety of core
bursting rhythms with specific phase-locked states, on distinct time scales,
that govern vital motor behaviors in invertebrates such as chewing, swimming,
etc. These movements in lower level animals mimic motions of organs in higher
animals due to evolutionarily conserved mechanisms. Hence, various neurological
diseases can be linked to abnormal movement of body parts that are regulated by
a malfunctioning CPG. In this paper, we, being inspired by recent experimental
studies of neuronal activity patterns recorded from a swimming motion CPG of
the sea slug {\it Melibe leonina}, examine a mathematical model of a 4-cell
network that can plausibly and stably underlie the observed bursting rhythm. We
develop a dynamical systems framework for explaining the existence and
robustness of phase-locked states in activity patterns produced by the modeled
CPGs. The proposed tools can be used for identifying core components for other
CPG networks with reliable bursting outcomes and specific phase relationships
between the interneurons. Our findings can be employed for identifying or
implementing the conditions for normal and pathological functioning of basic
CPGs of animals and artificially intelligent prosthetics that can regulate
various movements.


title: Density Functional Theory for Protein Transfer Free Energy

abstract:
  We cast the problem of protein transfer free energy within the formalism of
density functional theory (DFT), treating the protein as a source of external
potential that acts upon the solvent. Solvent excluded volume,
solvent-accessible surface area, and temperature-dependence of the transfer
free energy all emerge naturally within this formalism, and may be compared
with simplified "back of the envelope" models, which are also developed here.
Depletion contributions to osmolyte induced stability range from 5-$10\kB T$
for typical protein lengths. The general DFT transfer theory developed here may
be simplified to reproduce a Langmuir isotherm condensation mechanism on the
protein surface in the limits of short-ranged interactions, and dilute solute.
Extending the equation of state to higher solute densities results in
non-monotonic behavior of the free energy driving protein or polymer collapse.
Effective interaction potentials between protein backbone or sidechains and
TMAO are obtained, assuming a simple backbone/sidechain 2-bead model for the
protein with an effective 6-12 potential with the osmolyte. The transfer free
energy $\delta g$ shows significant entropy: $d(\delta g)/dT \approx 20 \kB$
for a 100 residue protein. The application of DFT to effective solvent forces
for use in implicit-solvent molecular dynamics is also developed. The simplest
DFT expressions for implicit-solvent forces contain both depletion interactions
and an "impeded-solvation" repulsive force at larger distances.


title:
Bayesian sparse graphical models and their mixtures using lasso
  selection priors

abstract:
  We propose Bayesian methods for Gaussian graphical models that lead to sparse
and adaptively shrunk estimators of the precision (inverse covariance) matrix.
Our methods are based on lasso-type regularization priors leading to
parsimonious parameterization of the precision matrix, which is essential in
several applications involving learning relationships among the variables. In
this context, we introduce a novel type of selection prior that develops a
sparse structure on the precision matrix by making most of the elements exactly
zero, in addition to ensuring positive definiteness -- thus conducting model
selection and estimation simultaneously. We extend these methods to finite and
infinite mixtures of Gaussian graphical models for clustered data using
Dirichlet process priors. We discuss appropriate posterior simulation schemes
to implement posterior inference in the proposed models, including the
evaluation of normalizing constants that are functions of parameters of
interest which result from the restrictions on the correlation matrix. We
evaluate the operating characteristics of our method via several simulations
and in application to real data sets.


title: A completeness-like relation for Bessel functions

abstract:
  Completeness relations are associated through Mercer's theorem to complete
orthonormal basis of square integrable functions, and prescribe how a Dirac
delta function can be decomposed into basis of eigenfunctions of a
Sturm-Liouville problem. We use Gegenbauer's addition theorem to prove a
relation very close to a completeness relation, but for a set of Bessel
functions not known to form a complete basis in $L^2[0, 1]$.


title:
Efficient Search (RES) for One-Hop Destination over Wireless Sensor
  Network

abstract:
  The revolution of wireless sensors networks (WSNs) has highly augmented the
expectations of people to get the work done efficiently, but there is little
bit impediment to deal with deployed nodes in WSNs. The nature of used routing
and medium access control (MAC) protocols in WSNs is completely different from
wireless adhoc network protocols. Sensor nodes do not have enough capability to
synchronize with robust way, in resulting causes of longer delay and waste of
energy. In this paper, we deploy efficientenergy consuming sensors and to find
one hop robust and efficient destination search in WSNs. We firstly deploy BT
(Bluetooth enabled) sensors, which offer passive and active sensing capability
to save energy. This work is a continuation of previous published work in [2].
The BT node is supported with efficient searchmethodss. The main objective of
this contribution is to control different types of objects from remote places
using cellular phone. To validate our proposed methodology,simulation is done
with network simulator (ns2) to examine the behavior of WSNs. Based on
simulation results, we claim that our approach saves 62% energy spent for
finding best one- hop destination as compared with existing techniques.


title:
Global Well-posedness of a System of Nonlinearly Coupled KdV equations
  of Majda and Biello

abstract:
  This paper addresses the problem of global well-posedness of a coupled system
of Korteweg-de Vries equations, derived by Majda and Biello in the context of
nonlinear resonant interaction of Rossby waves, in a periodic setting in
homogeneous Sobolev spaces $\dot H^s$, for $s\geq 0$. Our approach is based on
a successive time-averaging method developed by Babin, Ilyin and Titi [1].

categories: math.AP physics.ao-ph physics.flu-dyn physics.geo-ph


title: MALT90: The Millimetre Astronomy Legacy Team 90 GHz Survey

abstract:
  The Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey aims to
characterise the physical and chemical evolution of high-mass star-forming
clumps. Exploiting the unique broad frequency range and on-the-fly mapping
capabilities of the Australia Telescope National Facility Mopra 22 m
single-dish telescope, MALT90 has obtained 3' x 3' maps toward ~2000 dense
molecular clumps identified in the ATLASGAL 870 um Galactic plane survey. The
clumps were selected to host the early stages of high-mass star formation and
to span the complete range in their evolutionary states (from prestellar, to
protostellar, and on to HII regions and photodissociation regions). Because
MALT90 mapped 16 lines simultaneously with excellent spatial (38") and spectral
(0.11 km/s) resolution, the data reveal a wealth of information about the
clump's morphologies, chemistry, and kinematics. In this paper we outline the
survey strategy, observing mode, data reduction procedure, and highlight some
early science results. All MALT90 raw and processed data products are available
to the community. With its unprecedented large sample of clumps, MALT90 is the
largest survey of its type ever conducted and an excellent resource for
identifying interesting candidates for high resolution studies with ALMA.


title:
Study of ttH (H -> mu mu) in the three lepton channel at sqrt(s) = 14
  TeV; A Snowmass white paper

abstract:
  The H -> mu mu signature provides excellent mass resolution for Higgs bosons,
and is therefore an important Higgs boson decay channel despite the small
dimuon branching ratio. We present an optimization of selection criteria in a
search for trilepton ttH (H -> mu mu) events, in which the top quark pair
decays semi-leptonically, at a simulated High Luminosity LHC (HL-LHC) running
at 14 TeV. The study is performed with 3000 fb^(-1) of simulated data with an
average pileup of < mu > = 140. In this ultimate HL-LHC data set, we find that
ttH (H -> mu mu) will be a very difficult signature to observe due to the very
small expected signal.


title: Observing bulk diamond spin coherence in high-purity nanodiamonds

abstract:
  Nitrogen-vacancy centres (NVs) in diamond are attractive for research
straddling quantum information science and nanoscale magnetometry and
thermometry. While ultrapure bulk diamond NVs sustain the longest spin
coherence times among optically accessible spins, nanodiamond NVs display
persistently poor spin coherence. Here we introduce high-purity nanodiamonds
accommodating record-long NV coherence times, >60 us, observed via universal
dynamical decoupling. We show that the main contribution to decoherence comes
from nearby nitrogen impurities rather than surface states. We protect the NV
spin free precession, essential to DC magnetometry, by driving solely these
impurities into the motional narrowing regime. This extends the NV free
induction decay time from 440 ns, longer than that in type Ib bulk diamond, to
1.27 us, which is comparable to that in type IIa (impurity-free) diamond. These
properties allow the simultaneous exploitation of both high sensitivity and
nanometre resolution in diamond-based emergent quantum technologies.


title: Non-corotating models for pulsar magnetospheres

abstract:
  We reconsider pulsar electrodynamics for an obliquely rotating pulsar, and
propose a way of synthesizing the vacuum dipole model (VDM) and the rotating
magnetosphere model (RMM). We first modify the VDM by assuming that the
parallel component of the inductive electric field is screened by charges. We
refer to the resulting model as the minimal model. We calculate the screening
charge density in the minimal model and compare it with the (Goldreich-Julian)
charge density in the RMM. We identify the plasma velocity in the minimal model
as the electric drift velocity due to the perpendicular component of the
inductive electric field. We define a class of synthesized models as a linear
combination of a fraction $y$ times the minimal model and $1-y$ times the RMM.
These models require a gap (with $E_\parallel\ne0$) between the corotating
stellar surface and the non-corotating magnetosphere. We present illustrative
plots of the charge density, of the location of nulls (where the charge density
is zero) and of the three components of the plasma velocity as a function of
the angles ($\theta,\psi$) relative to the rotation axis, for specific values
of the obliquity $\alpha$ and the parameter $y$. We discuss the question "Can
any pulsar magnetosphere be corotating?" critically, pointing out difficulties
associated with setting up corotation in the polar cap region. We speculate
that the corotating plasma may flow across the last closed field line from the
closed-field region. We suggest that abrupt changes in the spin-down rate in
some pulsars may be due to jumps between the RMM and the minimal model.


title: The extended hypergeometric class of L\'evy processes

abstract:
  With a view to computing fluctuation identities related to stable processes,
we review and extend the class of hypergeometric L\'evy processes explored in
Kuznetsov and Pardo (arXiv:1012.0817). We give the Wiener-Hopf factorisation of
a process in the extended class, and characterise its exponential functional.
Finally, we give three concrete examples arising from transformations of stable
processes.


title:
Higher rho invariants and the moduli space of positive scalar curvature
  metrics

abstract:
  Given a closed smooth manifold M which carries a positive scalar curvature
metric, one can associate an abelian group P(M) to the space of positive scalar
curvature metrics on this manifold. The group of all diffeomorphisms of the
manifold naturally acts on P(M). The moduli group of positive scalar curvature
metrics is defined to be the quotient abelian group of this action, i.e. the
coinvariant of the action. The moduli group measures the size of the moduli
space of positive scalar curvature metrics on M. In this paper, we use the
higher rho invariant and the finite part of the K-theory of the group
C*-algebra of the fundamental group of M to give a lower bound of the rank of
the moduli group.


title: GOTCHA Password Hackers!

abstract:
  We introduce GOTCHAs (Generating panOptic Turing Tests to Tell Computers and
Humans Apart) as a way of preventing automated offline dictionary attacks
against user selected passwords. A GOTCHA is a randomized puzzle generation
protocol, which involves interaction between a computer and a human.
Informally, a GOTCHA should satisfy two key properties: (1) The puzzles are
easy for the human to solve. (2) The puzzles are hard for a computer to solve
even if it has the random bits used by the computer to generate the final
puzzle --- unlike a CAPTCHA. Our main theorem demonstrates that GOTCHAs can be
used to mitigate the threat of offline dictionary attacks against passwords by
ensuring that a password cracker must receive constant feedback from a human
being while mounting an attack. Finally, we provide a candidate construction of
GOTCHAs based on Inkblot images. Our construction relies on the usability
assumption that users can recognize the phrases that they originally used to
describe each Inkblot image --- a much weaker usability assumption than
previous password systems based on Inkblots which required users to recall
their phrase exactly. We conduct a user study to evaluate the usability of our
GOTCHA construction. We also generate a GOTCHA challenge where we encourage
artificial intelligence and security researchers to try to crack several
passwords protected with our scheme.


title:
Measurement of associated W + charm production in pp collisions at
  sqrt(s) = 7 TeV

abstract:
  Measurements are presented of the associated production of a W boson and a
charm-quark jet (W + c) in pp collisions at a center-of-mass energy of 7 TeV.
The analysis is conducted with a data sample corresponding to a total
integrated luminosity of 5 inverse femtobarns, collected by the CMS detector at
the LHC. W boson candidates are identified by their decay into a charged lepton
(muon or electron) and a neutrino. The W + c measurements are performed for
charm-quark jets in the kinematic region pt[jet] > 25 GeV, abs(eta) < 2.5, for
two different thresholds for the transverse momentum of the lepton from the
W-boson decay, and in the pseudorapidity range abs(eta[ell]) < 2.1. Hadronic
and inclusive semileptonic decays of charm hadrons are used to measure the
following total cross sections: sigma(pp to W + c + X) times B(W to ell nu) =
107.7 +/- 3.3 (stat.) +/- 6.9 (syst.) pb (pt[ell] > 25 GeV) and sigma(pp to W +
c + X) times B(W to ell nu) = 84.1 +/- 2.0 (stat.) +/- 4.9 (syst.) pb (pt[ell]
> 35 GeV), and the cross section ratios sigma(pp to W+ + c + X)/sigma(pp to W-
+ c + X) = 0.954 +/- 0.025 (stat.) +/- 0.004 (syst.) (pt[ell] > 25 GeV) and
sigma(pp to W+ + c bar + X)/sigma(pp to W- + c + X) = 0.938 +/- 0.019 (stat.)
+/- 0.006 (syst.) (pt[ell] > 35 GeV). Cross sections and cross section ratios
are also measured differentially with respect to the absolute value of the
pseudorapidity of the lepton from the W-boson decay. These are the first
measurements from the LHC directly sensitive to the strange quark and antiquark
content of the proton. Results are compared with theoretical predictions and
are consistent with the predictions based on global fits of parton distribution
functions.


title:
Boolean decision problems with competing interactions on scale-free
  networks: Equilibrium and nonequilibrium behavior in an external bias

abstract:
  We study the equilibrium and nonequilibrium properties of Boolean decision
problems with competing interactions on scale-free networks in an external bias
(magnetic field). Previous studies at zero field have shown a remarkable
equilibrium stability of Boolean variables (Ising spins) with competing
interactions (spin glasses) on scale-free networks. When the exponent that
describes the power-law decay of the connectivity of the network is strictly
larger than 3, the system undergoes a spin-glass transition. However, when the
exponent is equal to or less than 3, the glass phase is stable for all
temperatures. First, we perform finite-temperature Monte Carlo simulations in a
field to test the robustness of the spin-glass phase and show that the system
has a spin-glass phase in a field, i.e., exhibits a de Almeida-Thouless line.
Furthermore, we study avalanche distributions when the system is driven by a
field at zero temperature to test if the system displays self-organized
criticality. Numerical results suggest that avalanches (damage) can spread
across the whole system with nonzero probability when the decay exponent of the
interaction degree is less than or equal to 2, i.e., that Boolean decision
problems on scale-free networks with competing interactions can be fragile when
not in thermal equilibrium.


title: Resonant Excitation of Tilt Mode in Tidally Deformed Disks

abstract:
  In a previous paper (Kato 2013b), we have shown that in deformed disks a pair
of trapped oscillation modes can be resonantly excited through couplings with
disk deformation. In this paper we examine in what cases tilts are excited on
tidally deformed disks by the above-mentioned wave-wave resonant process. The
results show that tilts can be excited in various evolutional stages of tidally
deformed disks, although the wave mode which becomes the pair to the tilt and
the mode of tidal waves contributing to the resonance change by change of disk
stages.


title:
Generalized sampling: stable reconstructions, inverse problems and
  compressed sensing over the continuum

abstract:
  The purpose of this paper is to report on recent approaches to reconstruction
problems based on analog, or in other words, infinite-dimensional, image and
signal models. We describe three main contributions to this problem. First,
linear reconstructions from sampled measurements via so-called generalized
sampling (GS). Second, the extension of generalized sampling to inverse and
ill-posed problems. And third, the combination of generalized sampling with
sparse recovery techniques. This final contribution leads to a theory and set
of methods for infinite-dimensional compressed sensing, or as we shall also
refer to it, compressed sensing over the continuum.


title: Non-Arbitrage up to Random Horizon for Semimartingale Models

abstract:
  This paper addresses the question of how an arbitrage-free semimartingale
model is affected when stopped at a random horizon. We focus on
No-Unbounded-Profit-with-Bounded-Risk (called NUPBR hereafter) concept, which
is also known in the literature as the first kind of non-arbitrage. For this
non-arbitrage notion, we obtain two principal results. The first result lies in
describing the pairs of market model and random time for which the resulting
stopped model fulfills NUPBR condition. The second main result characterises
the random time models that preserve the NUPBR property after stopping for any
market model. These results are elaborated in a very general market model, and
we also pay attention to some particular and practical models. The analysis
that drives these results is based on new stochastic developments in
semimartingale theory with progressive enlargement. Furthermore, we construct
explicit martingale densities (deflators) for some classes of local martingales
when stopped at random time.


title: In-plane spin excitation anisotropy in the paramagnetic phase of NaFeAs

abstract:
  We use unpolarized and polarized inelastic neutron scattering to study
low-energy spin excitations in NaFeAs, which exhibits a
tetragonal-to-orthorhombic lattice distortion at $T_s\approx 58$ K followed by
a collinear antiferromagnetic (AF) order below $T_N\approx 45$ K. In the AF
ordered state ($T<T_N$), spin waves are entirely c-axis polarized below
$\sim$10 meV, exhibiting a gap of $\sim4$ meV at the AF zone center and
disperse to $\sim$7 meV near the c-axis AF zone boundary. On warming to the
paramagnetic state with orthorhombic lattice distortion ($T_N<T<T_s$), spin
excitations become anisotropic within the FeAs plane. Upon further warming to
the paramagnetic tetragonal state ($T>T_s$), spin excitations become more
isotropic. Since similar magnetic anisotropy is also observed in the
paramagnetic tetragonal phase of superconducting
BaFe$_{1.904}$Ni$_{0.096}$As$_2$, our results suggest that the spin excitation
anisotropy in superconducting iron pnictides originates from similar anisotropy
already present in their parent compounds.


title:
The moduli stack of parabolic bundles over the projective line, quiver
  representations, and the Deligne-Simpson problem

abstract:
  In "Quantization of Hitchin's Integrable System and Hecke Eigensheaves",
Beilinson and Drinfeld introduced the "very good" property for a smooth complex
equidimensional stack. They prove that for a semisimple complex group G, the
moduli stack of G-bundles over a smooth complex projective curve X is "very
good", as long as X has genus g > 1. In the case of the projective line, when g
= 0, this is not the case. However, the result can sometimes be extended to the
projective line by introducing additional parabolic structure at a collection
of marked points and slightly modifying the definition of a "very good" stack.
We provide a sufficient condition for the moduli stack of parabolic vector
bundles over the complex projective line to be very good. We then use this
property to study the space of solutions to the Deligne-Simpson problem.


title:
LiteRed 1.4: a powerful tool for the reduction of the multiloop
  integrals

abstract: We review the Mathematica package LiteRed, version 1.4.


title: Iterative stochastic subspace self-consistent field method

abstract:
  We propose a new self-consistent field (SCF) algorithm based on an iterative,
partially stochastic \textit{``Divide \& Conquer''}-type approach. This new SCF
algorithm is a simple variant of the usual SCF procedure and can be easily
implemented in parallel. A detailed description of the algorithm is reported.
We illustrate this new method on one-dimensional hydrogen chains and
three-dimensional hydrogen clusters.


title: A Unified Primal Dual Active Set Algorithm for Nonconvex Sparse Recovery

abstract:
  In this paper, we consider the problem of recovering a sparse signal based on
penalized least squares formulations. We develop a novel algorithm of
primal-dual active set type for a class of nonconvex sparsity-promoting
penalties, including $\ell^0$, bridge, smoothly clipped absolute deviation,
capped $\ell^1$ and minimax concavity penalty. First we establish the existence
of a global minimizer for the related optimization problems. Then we derive a
novel necessary optimality condition for the global minimizer using the
associated thresholding operator. The solutions to the optimality system are
coordinate-wise minimizers, and under minor conditions, they are also local
minimizers. Upon introducing the dual variable, the active set can be
determined using the primal and dual variables together. Further, this relation
lends itself to an iterative algorithm of active set type which at each step
involves first updating the primal variable only on the active set and then
updating the dual variable explicitly. When combined with a continuation
strategy on the regularization parameter, the primal dual active set method is
shown to converge globally to the underlying regression target under certain
regularity conditions. Extensive numerical experiments with both simulated and
real data demonstrate its superior performance in efficiency and accuracy
compared with the existing sparse recovery methods.


title:
Designing a robustly metallic noncenstrosymmetric ruthenate oxide with
  large thermopower anisotropy

abstract:
  The existence of approximately 30 noncentrosymmetric metals (NCSM) suggests a
contraindication between crystal structures without inversion symmetry and
metallic behavior. Those containing oxygen are especially scarce. Here we
propose and demonstrate a design framework to remedy this property disparity
and accelerate NCSM-oxide discovery: The primary ingredient relies on the
removal of inversion symmetry through displacements of atoms whose electronic
degrees of freedom are decoupled from the states at the Fermi level. Density
functional theory calculations validate this crystal--chemistry strategy, and
we predict a new polar ruthenate exhibiting robust metallicity. We demonstrate
that the electronic structure is unaffected by the inclusion of spin-orbit
interactions (SOI), and that cation ordered SrCaRu$_2$O$_6$ exhibits a large
thermopower anisotropy ($\left|\Delta\mathcal{S}_\perp\right|\sim6.3 \mu
\textrm{V K}^{-1}$ at 300 K) derived from its polar structure. Our findings
provide chemical and structural selection guidelines to aid in the search of
new NCS metals with enhanced thermopower anisotropy.


title: Stable solutions of equations with a quadratic gradient term

abstract:
  We study existence and regularity properties of stable positive solutions to
the nonvariational problem - Delta u - b(x)|nabla u|^2 = lambda g(u) in a
bounded smooth domain. In the case where b is constant, by means of a Hopf-Cole
transformation, the problem can be taken to a variational form, for which there
are classical results of Crandall-Rabinowitz, Mignot-Puel and Brezis-Vazquez.
In this paper we obtain results for a general bounded function b=b(x) which
coincide with the classical ones in the constant b case.


title: Complex structural dynamics of bismuth under laser-driven compression

abstract:
  With the aid of nanosecond time-resolved X-ray diffraction techniques, we
have explored the complex structural dynamics of bismuth under laser-driven
compression. The results demonstrate that shocked bismuth undergoes a series of
structural transformations involving four solid structures: the Bi-I, Bi-II,
Bi-III and Bi-V phases. The transformation from the Bi-I phase to the Bi-V
phase occurs within 4 ns under shock compression at ~11 GPa, showing no
transient phases with the available experimental conditions. Successive phase
transitions (Bi-V->Bi-III->Bi-II->Bi-I) during the shock release within 30 ns
have also been resolved, which were inaccessible using other dynamic
techniques.


title:
Chemical abundances in the extremely Carbon and Xenon-rich halo
  planetary nebula H4-1

abstract:
  We performed detailed chemical abundance analysis of the extremely metal-poor
([Ar/H]-2) halo planetary nebula H4-1 based on the multi-wavelength spectra
from Subaru/HDS, GALEX, SDSS, and Spitzer/IRS and determined the abundances of
10 elements. The C and O abundances were derived from collisionally excited
lines (CELs) and are almost consistent with abundances from recombination lines
(RLs). We demonstrated that the large discrepancy in the C abundance between
CEL and RL in H4-1 can be solved using the temperature fluctuation model. We
reported the first detection of the [Xe III]5846 A line in H4-1 and
determination of its elemental abundance ([Xe/H]>+0.48). H4-1 is the most
Xe-rich PN among the Xe-detected PNe. The observed abundances are close to the
theoretical prediction by a ~2.0 Msun single star model with initially
r-process element rich ([r/Fe]=+2.0 dex). The observed Xe abundance would be a
product of the r-process in primordial SNe. The [C/O]-[Ba/(Eu or Xe)] diagram
suggests that the progenitor of H4-1 shares the evolution with two types of
carbon-enhanced metal-poor stars (CEMP), CEMP-r/s and CEMP-no stars. The
progenitor of H4-1 is a presumably binary formed in an r-process rich
environment.


title: A Primal-Dual Method of Partial Inverses for Composite Inclusions

abstract:
  Spingarn's method of partial inverses has found many applications in
nonlinear analysis and in optimization. We show that it can be employed to
solve composite monotone inclusions in duality, thus opening a new range of
applications for the partial inverse formalism. The versatility of the
resulting primal-dual splitting algorithm is illustrated through applications
to structured monotone inclusions and optimization.


title: The Gaussian Two-way Diamond Channel

abstract:
  We consider two-way relaying in a Gaussian diamond channel, where two
terminal nodes wish to exchange information using two relays. A simple baseline
protocol is obtained by time-sharing between two one-way protocols. To improve
upon the baseline performance, we propose two compute-and-forward (CF)
protocols: Compute-and-forward Compound multiple access channel (CF-CMAC) and
Compute-and-forward-Broadcast (CF-BC). These protocols mix the two flows
through the two relays and achieve rates better than the simple time-sharing
protocol. We derive an outer bound to the capacity region that is satisfied by
any relaying protocol, and observe that the proposed protocols provide rates
close to the outer bound in certain channel conditions. Both the CF-CMAC and
CF-BC protocols use nested lattice codes in the compute phases. In the CF-CMAC
protocol, both relays simultaneously forward to the destinations over a
Compound Multiple Access Channel (CMAC). In the simpler CF-BC protocol's
forward phase, one relay is selected at a time for Broadcast Channel (BC)
transmission depending on the rate-pair to be achieved. We also consider the
diamond channel with direct source-destination link and the diamond channel
with interfering relays. Outer bounds and achievable rate regions are compared
for these two channels as well. Mixing of flows using the CF-CMAC protocol is
shown to be good for symmetric two-way rates.


title: On deformation spaces of nonuniform hyperbolic lattices

abstract:
  Let $\Gamma$ be a nonuniform lattice acting on real hyperbolic n-space. We
show that in dimension greater than or equal to 4, the volume of a
representation is constant on each connected component of the representation
variety of $\Gamma$ in SO(n,1). Furthermore, in dimensions 2 and 3, there is a
semialgebraic subset of the representation variety such that the volume of a
representation is constant on connected components of the semialgebraic subset.
Our approach gives a new proof of the local rigidity theorem for nonuniform
hyperbolic lattices and the analogue of Soma's theorem, which shows that the
number of orientable hyperbolic manifolds dominated by a closed, connected,
orientable 3-manifold is finite, for noncompact 3-manifolds.


title: HI Lyman-alpha equivalent widths of stellar populations

abstract:
  We have compiled a library of stellar Lyman-alpha equivalent widths in O and
B stars using the model atmosphere codes CMFGEN and TLUSTY, respectively. The
equivalent widths range from about 0 to 30 \AA in absorption for early-O to
mid-B stars. The purpose of this library is the prediction of the underlying
stellar Lyman-alpha absorption in stellar populations of star-forming galaxies
with nebular Lyman-alpha emission. We implemented the grid of individual
equivalent widths into the Starburst99 population synthesis code to generate
synthetic Lyman-alpha equivalent widths for representative star-formation
histories. A starburst observed after 10 Myr will produce a stellar Lyman-alpha
line with an equivalent width of $\sim$ -10$\pm$4 \AA in absorption for a
Salpeter initial mass function. The lower value (deeper absorption) results for
an instantaneous burst, and the higher value (shallower line) for continuous
star formation. Depending on the escape fraction of nebular Lyman-alpha
photons, the effect of stellar Lyman-alpha on the total profile ranges from
negligible to dominant. If the nebular escape fraction is 10%, the stellar
absorption and nebular emission equivalent widths become comparable for
continuous star formation at ages of 10 to 20 Myr.


title: A Generalization of Aztec Diamond Theorem, Part II

abstract:
  The author gave a proof of a generalization of the Aztec diamond theorem for
a family of $4$-vertex regions on the square lattice with
southwest-to-northeast diagonals drawn in (Electron. J. Combin., 2014) by using
a bijection between tilings and non-intersecting lattice paths. In this paper,
we use Kuo graphical condensation to give a new proof.


title:
Predicted Novel Hydrogen Hydrate Structures under Pressure from First
  Principles

abstract:
  Gas hydrates are systems of prime importance. In particular, hydrogen
hydrates are potential materials of icy satellites and comets, and may be used
for hydrogen storage. We explore the H2O-H2 system at pressures in the range
0-100 GPa with ab initio variable-composition evolutionary simulations.
According to our calculation and previous experiments, the H2O-H2 system
undergoes a series of transformations with pressure, and adopts the known
open-network clathrate structures (sII, C0), dense "filled ice" structures (C1,
C2) and two novel hydrate phases. One of these is based on the hexagonal ice
framework and has the same H2O:H2 ratio (2:1) as the C0 phase at low pressures
and similar enthalpy (we name this phase Ih-C0). The other newly predicted
hydrate phase has a 1:2 H2O:H2 ratio and structure based on cubic ice. This
phase (which we name C3) is predicted to be thermodynamically stable above 38
GPa when including van der Waals interactions and zero-point vibrational
energy, and explains previously mysterious experimental X-ray diffraction and
Raman measurements. This is the hydrogen-richest hydrate and this phase has a
remarkable gravimetric density (18 wt.%) of easily extractable hydrogen.


title:
Covalency in transition metal oxides within all-electron Dynamical Mean
  Field Theory

abstract:
  A combination of dynamical mean field theory and density functional theory,
as implemented in Phys. Rev. B 81, 195107 (2010), is applied to both the early
and late transition metal oxides. For fixed value of the local Coulomb
repulsion, without fine tuning, we obtain the main features of these series,
such as the metallic character of SrVO$_3$ and the the insulating gaps of
LaVO$_3$, LaTiO$_3$ and La$_2$CO$_4$ which are in good agreement with
experiment. The study highlights the importance of local physics and high
energy hybridization in the screening of the Hubbard interaction and how
different low energy behaviors can emerge from the a unified treatment of the
transition metal series.


title:
Six model structures for DG-modules over DGAs: Model category theory in
  homological action

abstract:
  In Part 1, we describe six projective-type model structures on the category
of differential graded modules over a differential graded algebra A over a
commutative ring R. When R is a field, the six collapse to three and are
well-known, at least to folklore, but in the general case the new relative and
mixed model structures offer interesting alternatives to the model structures
in common use. The construction of some of these model structures requires two
new variants of the small object argument, an enriched and an algebraic one,
and we describe these more generally. In Part 2, we present a variety of
theoretical and calculational cofibrant approximations in these model
categories. The classical bar construction gives cofibrant approximations in
the relative model structure, but generally not in the usual one. In the usual
model structure, there are two quite different ways to lift cofibrant
approximations from the level of homology modules over homology algebras, where
they are classical projective resolutions, to the level of DG-modules over
DG-algebras. The new theory makes model theoretic sense of earlier explicit
calculations based on one of these constructions. A novel phenomenon we
encounter is isomorphic cofibrant approximations with different combinatorial
structure such that things proven in one avatar are not readily proven in the
other.


title:
Photoemission of Bi$_2$Se$_3$ with Circularly Polarized Light: Probe of
  Spin Polarization or Means for Spin Manipulation?

abstract:
  Topological insulators are characterized by Dirac cone surface states with
electron spins aligned in the surface plane and perpendicular to their momenta.
Recent theoretical and experimental work implied that this specific spin
texture should enable control of photoelectron spins by circularly polarized
light. However, these reports questioned the so far accepted interpretation of
spin-resolved photoelectron spectroscopy. We solve this puzzle and show that
vacuum ultraviolet photons (50-70 eV) with linear or circular polarization
probe indeed the initial state spin texture of Bi$_2$Se$_3$ while circularly
polarized 6 eV low energy photons flip the electron spins out of plane and
reverse their spin polarization. Our photoemission calculations, considering
the interplay between the varying probing depth, dipole selection rules and
spin-dependent scattering effects involving initial and final states explain
these findings, and reveal proper conditions for light-induced spin
manipulation. This paves the way for future applications of topological
insulators in opto-spintronic devices.


title: Identifying Correlated Heavy-Hitters in a Two-Dimensional Data Stream

abstract:
  We consider online mining of correlated heavy-hitters from a data stream.
Given a stream of two-dimensional data, a correlated aggregate query first
extracts a substream by applying a predicate along a primary dimension, and
then computes an aggregate along a secondary dimension. Prior work on
identifying heavy-hitters in streams has almost exclusively focused on
identifying heavy-hitters on a single dimensional stream, and these yield
little insight into the properties of heavy-hitters along other dimensions. In
typical applications however, an analyst is interested not only in identifying
heavy-hitters, but also in understanding further properties such as: what other
items appear frequently along with a heavy-hitter, or what is the frequency
distribution of items that appear along with the heavy-hitters. We consider
queries of the following form: In a stream S of (x, y) tuples, on the substream
H of all x values that are heavy-hitters, maintain those y values that occur
frequently with the x values in H. We call this problem as Correlated
Heavy-Hitters (CHH). We formulate an approximate formulation of CHH
identification, and present an algorithm for tracking CHHs on a data stream.
The algorithm is easy to implement and uses workspace which is orders of
magnitude smaller than the stream itself. We present provable guarantees on the
maximum error, as well as detailed experimental results that demonstrate the
space-accuracy trade-off.


title:
A Little Prediction Goes a Long Way: Routing in Semi-Deterministic Delay
  Tolerant Networks

abstract:
  Realizing delay-capacity in intermittently connected mobile networks remains
a largely open question, with state-of-the-art routing schemes typically
focusing either on delay or on capacity. We show the feasibility of routing
with both high goodput and desired delay constraints, with REAPER (for
Reliable, Efficient, and Predictive Routing), a fully distributed convergecast
routing framework that jointly optimizes both path length and path delay. A key
idea for efficient instantiation of REAPER is to exploit predictability of
mobility patterns, in terms of a semi-deterministic model which appropriately
captures several vehicular and human inter-contact patterns. Packets are thus
routed using paths that are jointly optimal at their time of arrival, in
contrast to extant DTN protocols which use time-average metrics for routing.
REAPER is also self-stabilizing to changes in the mobility pattern. A
simulation-based evaluation confirms that, across the spectrum of ultra-light
to heavy traffics, REAPER achieves up to 135% and 200% higher throughput and up
to 250% and 1666% higher energy efficiency than state-of-the-art single-copy
protocols MEED-DVR and PROPHET, which optimize a single metric only,
specifically, expected delay and path probability respectively.


title:
Observation of a charged (DD*bar)- mass peak in e+e- --> pi+ (DD*bar)-
  at Ecm=4.26 GeV

abstract:
  We report on a study of the process e+e- --> pi+(D D*bar)- at Ecm=4.26 GeV
using a 525 /pb data sample collected with the BESIII detector at the BEPCII
storage ring. A distinct charged structure is observed in the (DD*bar)-
invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner
lineshape, the pole mass and width are determined to be M_pole=(3883.9 +- 1.5
+- 4.2) MeV and Gamma_pole=(24.8 +- 3.3 +- 11.0) MeV. The mass and width of the
structure, which we refer to as Z_c(3885), are 2sigma and 1sigma, respectively,
below those of the Z_c(3900) --> pi+J/psi peak observed by BESIII and Belle in
pi+pi-J/psi final states produced at the same center-of-mass energy. The
angular distribution of the pi Z_c(3885) system favors a JP=1+ quantum number
assignment for the structure and disfavors 1- or 0-. The Born cross section
times the DD*bar branching fraction of the Z_(3885) is measured to be
sigma(e+e- --> pi+ Z_c(3885)-) x Bf(Z_c(3885)-->DD*bar)=(83.5 +-6.6 +- 22.0)
pb. Assuming the Z_c(3885) --> DD*bar signal reported here and the Z_c(3900)
--> pi J/psi signal are from the same source, the partial width ratio
Gamma(Z_c(3885) --> DD*bar)/Gamma(Z_c(3900) -->pi J/psi)=6.2 +- 1.1 +- 2.7 is
determined.


title:
Almost Difference Sets, Normally Regular Digraphs and Cyclotomic Schemes
  from Cyclotomy of Order Twelve

abstract:
  Using cyclotomic classes of order twelve for certain finite fields, we
construct an infinite family of almost difference sets and normally regular
graphs applying the theory of cyclotomy. We show that in each of these fields
neither the multiplicative cyclic subgroup $C$ of index twelve nor $C\cup
\{0\}$ forms an almost difference set, but a union of cosets of $C$ provides us
an almost difference set. We also calculate the intersection numbers and
character tables of cyclotomic association schemes of class two, three and four
obtained from these fields.


title: The Effects of Minimal Length in Entropic Force Approach

abstract:
  With Verlinde's recent proposal which says that gravity can be identified
with an entropic force and considering the effects of generalized uncertainty
principle in the black hole entropy-area relation we derive the modified
equations for Newton's law of gravitation, modified Newtonian dynamics and
Einstein's general relativity. The corrections to the Newtonian potential is
compared with the corrections that come from Randall-Sundrum II model and an
effective field theoretical model of quantum general relativity. The effect of
the generalized uncertainty principle introduces a $\sqrt{\text{Area}}$ type
correction term in the entropy area relation whose consequences in different
scenarios are discussed.

categories: gr-qc astro-ph.CO hep-th physics.class-ph


title: Flipping Edge-Labelled Triangulations

abstract:
  Flips in triangulations have received a lot of attention over the past
decades. However, the problem of tracking where particular edges go during the
flipping process has not been addressed. We examine this question by attaching
unique labels to the triangulation edges. We introduce the concept of the orbit
of an edge $e$, which is the set of all edges reachable from $e$ via flips.
  We establish the first upper and lower bounds on the diameter of the flip
graph in this setting. Specifically, we prove tight $\Theta(n \log n)$ bounds
for edge-labelled triangulations of $n$-vertex convex polygons and
combinatorial triangulations, contrasting with the $\Theta(n)$ bounds in their
respective unlabelled settings. The $\Omega(n \log n)$ lower bound for the
convex polygon setting might be of independent interest, as it generalizes
lower bounds on certain sorting models. When simultaneous flips are allowed,
the upper bound for convex polygons decreases to $O(\log^2 n)$, although we no
longer have a matching lower bound.
  Moving beyond convex polygons, we show that edge-labelled triangulated
polygons with a single reflex vertex can have a disconnected flip graph. This
is in sharp contrast with the unlabelled case, where the flip graph is
connected for any triangulated polygon. For spiral polygons, we provide a
complete characterization of the orbits. This allows us to decide connectivity
of the flip graph of a spiral polygon in linear time. We also prove an upper
bound of $O(n^2)$ on the diameter of each connected component, which is optimal
in the worst case. We conclude with an example of a non-spiral polygon whose
flip graph has diameter $\Omega(n^3)$.


title:
Analysis of Errors: A Support System for Teachers to Analyse the Error
  Occurring to a Novice Programmer

abstract:
  For a novice programmer, coding is equivalent to a nightmare. A novice
programmer tries to replicate steps provided by the faculty and on compilation
gets a number of errors which the novice programmer is not able to resolve.
This system provides support to the faculty about the coding ability of the
students and their ability to solve those errors. Also, the faculty can provide
a solution to the errors which are occurring to the students and the solution
is displayed accordingly. The emphasis of this paper is on developing this
system within JAVA and making use of Online Compilers. Moreover, we focus on a
new system which is able to provide online code management and these codes get
compiled using an online compiler and these programs can be viewed by the
respective faculty for cross verification. This paper takes into account the
syntactic errors, runtime and semantic errors.


title: Generalized supersymmetry and sigma models

abstract:
  In this paper, we discuss the generalizations of exact supersymmetries
present in the supersymmetrized sigma models. These generalizations are made by
making the supersymmetric transformation parameter field-dependent. Remarkably,
the supersymmetric effective actions emerge naturally through the Jacobian
associated with the generalized supersymmetry transformations. We explicitly
demonstrate these for two different supersymmetric sigma models, namely, one
dimensional sigma model and topological sigma model for hyperinstantons on
quaternionic manifold.


title:
Associated Spaces of Generalized Classical Lorentz Spaces
  $G\Lambda_{p,\psi;\varphi}$

abstract:
  In this paper we have calculated the associate norms of the
$G\Lambda_{p,\psi;\varphi}$ generalized classical Lorentz spaces.


title: Diffusion in active magnetic colloids

abstract:
  Properties of active colloids of circle swimmers are reviewed. As an
particular example of active magnetic colloids the magnetotactic bacteria under
the action of a rotating magnetic field is considered. The relation for a
diffusion coefficient due to the random switching of the direction of rotation
of their rotary motors is derived on the basis of the master equation. The
obtained relation is confirmed by the direct numerical simulation of random
trajectory of a magnetotactic bacterium under the action of the Poisson type
internal noise due to the random switching of rotary motors. The results
obtained are in qualitative and quantitative agreement with the available
experimental results and allows one to determine the characteristic time
between the switching events of a rotary motor of the bacterium.


title:
Results of a one-way experiment to test the isotropy of the speed of
  light

abstract:
  This paper presents the outcome of an experiment based on an improved version
of Fizeau's coupled-slotted-discs that tests the fundamental postulates of
Special Relativity for the one-way speed of light propagation. According to our
methodology, important phenomena - a limit on and the diurnal regularity of the
variation of the speed of light due to the movements of the Earth (assuming
that the speed of light follows a Galilean transformation) - can be tested by
the present experiment. However, these measurements do not indicate any
significant diurnal variation. Consequently, the limit of the present outcome
on the variation of the speed of light is insignificant. Assuming that the
speed of light is not invariant and performing a rigorous statistical analysis,
the limit established is approximately 1/50 of the previous Fizeau-type
experiment with 95% confidence level. These outcomes are consistent with the
assumptions of Einstein's Special Relativity.


title: Processes that can be embedded in a geometric Brownian motion

abstract:
  The main result is a counterpart of the theorem of Monroe [\emph{Ann.
Probability} \textbf{6} (1978) 42--56] for a geometric Brownian motion: A
process is equivalent to a time change of a geometric Brownian motion if and
only if it is a nonnegative supermartingale. We also provide a link between our
main result and Monroe [\emph{Ann. Math. Statist.} \textbf{43} (1972)
1293--1311]. This is based on the concept of a \emph{minimal} stopping time,
which is characterised in Monroe [\emph{Ann. Math. Statist.} \textbf{43} (1972)
1293--1311] and Cox and Hobson [\emph{Probab. Theory Related Fields}
\textbf{135} (2006) 395--414] in the Brownian case. We finally suggest a
sufficient condition for minimality (for the processes other than a Brownian
motion) complementing the discussion in the aforementioned papers.


title: Weak approximation of second-order BSDEs

abstract:
  We study the weak approximation of the second-order backward SDEs (2BSDEs),
when the continuous driving martingales are approximated by discrete time
martingales. We establish a convergence result for a class of 2BSDEs, using
both robustness properties of BSDEs, as proved in Briand, Delyon and M\'{e}min
[Stochastic Process. Appl. 97 (2002) 229-253], and tightness of solutions to
discrete time BSDEs. In particular, when the approximating martingales are
given by some particular controlled Markov chains, we obtain several concrete
numerical schemes for 2BSDEs, which we illustrate on specific examples.


title: Full-Rank Perfect Codes over Finite Fields

abstract:
  In this paper, we propose a construction of full-rank q-ary 1-perfect codes
over finite fields. This construction is a generalization of the Etzion and
Vardy construction of full-rank binary 1-perfect codes (1994). Properties of
i-components of q-ary Hamming codes are investigated and the construction of
full-rank q-ary 1-perfect codes is based on these properties. The switching
construction of 1-perfect codes are generalized for the q-ary case. We give a
generalization of the concept of i-component of 1-perfect codes and introduce
the concept of (i,{\sigma})-components of q-ary 1-perfect codes. We also
present a generalization of the Lindstr\"om and Sch\"onheim construction of
q-ary 1-perfect codes and provide a lower bound on the number of pairwise
distinct q-ary 1-perfect codes of length n.


title:
Extraordinary luminous soft X-ray transient MAXI J0158-744 as an
  ignition of a nova on a very massive O-Ne white dwarf

abstract:
  We present the observation of an extraordinary luminous soft X-ray transient,
MAXI J0158-744, by the Monitor of All-sky X-ray Image (MAXI) on 2011 November
11. This transient is characterized by a soft X-ray spectrum, a short duration
(1.3 x 10^3 s < \Delta T_d < 1.10 x 10^4 s), a very rapid rise (< 5.5 x 10^3
s), and a huge peak luminosity of 2 x 10^40 erg s^-1 in 0.7-7.0 keV band. With
Swift observations and optical spectroscopy from the Small and Moderate
Aperture Research Telescope System (SMARTS), we confirmed that the transient is
a nova explosion, on a white dwarf in a binary with a Be star, located near the
Small Magellanic Cloud. An extremely early turn-on of the super-soft X-ray
source (SSS) phase (< 0.44 d), the short SSS phase duration of about one month,
and a 0.92 keV neon emission line found in the third MAXI scan, 1296 s after
the first detection, suggest that the explosion involves a small amount of
ejecta and is produced on an unusually massive O-Ne white dwarf close to, or
possibly over, the Chandrasekhar limit. We propose that the huge luminosity
detected with MAXI was due to the fireball phase, a direct manifestation of the
ignition of the thermonuclear runaway process in a nova explosion.


title: Structure and compositeness of hadron resonances

abstract:
  The structure of the hadron resonances attracts much attention, in
association with the recent observations of various exotic hadrons which do not
fit well in the conventional picture. These findings urge us to consider
various new configurations such as the multiquark states and the hadronic
molecules. However, it is a subtle problem to define a proper classification
scheme for the hadron structure, and the nonzero decay width of the hadron
resonances makes the analysis complicated. In this paper, we summarize the
recent developments in the studies of the structure of the hadron resonances,
focusing on the notion of the compositeness in terms of the hadronic degrees of
freedom.


title:
Clustering on Multiple Incomplete Datasets via Collective Kernel
  Learning

abstract:
  Multiple datasets containing different types of features may be available for
a given task. For instance, users' profiles can be used to group users for
recommendation systems. In addition, a model can also use users' historical
behaviors and credit history to group users. Each dataset contains different
information and suffices for learning. A number of clustering algorithms on
multiple datasets were proposed during the past few years. These algorithms
assume that at least one dataset is complete. So far as we know, all the
previous methods will not be applicable if there is no complete dataset
available. However, in reality, there are many situations where no dataset is
complete. As in building a recommendation system, some new users may not have a
profile or historical behaviors, while some may not have a credit history.
Hence, no available dataset is complete. In order to solve this problem, we
propose an approach called Collective Kernel Learning to infer hidden sample
similarity from multiple incomplete datasets. The idea is to collectively
completes the kernel matrices of incomplete datasets by optimizing the
alignment of the shared instances of the datasets. Furthermore, a clustering
algorithm is proposed based on the kernel matrix. The experiments on both
synthetic and real datasets demonstrate the effectiveness of the proposed
approach. The proposed clustering algorithm outperforms the comparison
algorithms by as much as two times in normalized mutual information.


title: Dead layer on silicon p-i-n diode charged-particle detectors

abstract:
  Semiconductor detectors in general have a dead layer at their surfaces that
is either a result of natural or induced passivation, or is formed during the
process of making a contact. Charged particles passing through this region
produce ionization that is incompletely collected and recorded, which leads to
departures from the ideal in both energy deposition and resolution. The silicon
\textit{p-i-n} diode used in the KATRIN neutrino-mass experiment has such a
dead layer. We have constructed a detailed Monte Carlo model for the passage of
electrons from vacuum into a silicon detector, and compared the measured energy
spectra to the predicted ones for a range of energies from 12 to 20 keV. The
comparison provides experimental evidence that a substantial fraction of the
ionization produced in the "dead" layer evidently escapes by diffusion, with
46% being collected in the depletion zone and the balance being neutralized at
the contact or by bulk recombination. The most elementary model of a thinner
dead layer from which no charge is collected is strongly disfavored.


title: Variability in Spectropolarimetric properties of Sy 1.5 galaxy Mrk 6

abstract:
  Here we present an analysis of spectro-polarimetric observations of type 1.5
AGN Mrk 6, performed with 6m telescope SAO RAN in 12 epochs (2010 -- 2013).
Additionally, the inter-stellar mater (ISM) polarization has been observed and
its contribution to the AGN spectral polarization is taken into account.
  We measured Stokes parameters and determined the polarization parameters in
12 spectra with and without correction for the ISM polarization. We estimated
the time lag between the unpolarized and polarized continuum flux variation of
about ~2 days, that indicates a compact scattering region which contributes to
the polarized continuum variability. The polarization in H{\alpha} is complex,
showing three prominent components in the BLR, one redshifted around +3000 km/s
that corresponds to the red shoulder in H{\alpha}, and two blue-shifted around
-2000 km/s and -6000 km/s.
  We found that the ISM polarization has a very significant influence on the
measured AGN polarization parameters. After correcting the observations for the
ISM polarization we were able to detect the Keplerian motion in the BLR.
  We give a new method for the black hole mass estimation using
spectro-polarimetric observation in the line profile, finding the black hole
mass in Mrk 6 of $M_{BH} \sim 1.53 \cdot 10^8 M_{\odot}$, that is in a good
agreement with reverberation estimates.


title:
The "Eating up Assumption", Transversality Conditions, and Steady States
  for Discrete Time Infinite Horizon Problems

abstract:
  In this paper, we consider how to construct the optimal solutions for a
general discrete time infinite horizon optimal control problem. We establish
necessary and sufficient conditions for optimality in the sense of a modified
optimality criterion. We also consider how transversality conditions are
related to steady states. The results are applied to two examples to
demonstrate how the new transversality conditions derived in this paper differ
from those given in the previous literature.


title:
On the expectation of normalized Brownian functionals up to first
  hitting times

abstract:
  Let B be a Brownian motion and T its first hitting time of the level 1. For U
a uniform random variable independent of B, we study in depth the distribution
of T^{-1/2}B_{UT}, that is the rescaled Brownian motion sampled at uniform
time. In particular, we show that this variable is centered.


title:
A model space approach to some classical inequalities for rational
  functions

abstract:
  We consider the set \mathcal{R}_{n} of rational functions of degree at most
n\geq1 with no poles on the unit circle \mathbb{T} and its subclass
\mathcal{R}_{n,\, r} consisting of rational functions without poles in the
annulus \left\{\xi:\; r\leq|\xi|\leq\frac{1}{r}\right\}. We discuss an approach
based on the model space theory which brings some integral representations for
functions in \mathcal{R}_{n} and their derivatives. Using this approach we
obtain L^{p}-analogs of several classical inequalities for rational functions
including the inequalities by P. Borwein and T. Erd\'elyi, the Spijker Lemma
and S.M. Nikolskii's inequalities. These inequalities are shown to be
asymptotically sharp as n tends to infinity and the poles of the rational
functions approach the unit circle \mathbb{T}.


title:
Spatially Varying Coefficient Model for Neuroimaging Data with Jump
  Discontinuities

abstract:
  Motivated by recent work on studying massive imaging data in various
neuroimaging studies, we propose a novel spatially varying coefficient model
(SVCM) to spatially model the varying association between imaging measures in a
three-dimensional (3D) volume (or 2D surface) with a set of covariates. Two key
features of most neuorimaging data are the presence of multiple piecewise
smooth regions with unknown edges and jumps and substantial spatial
correlations. To specifically account for these two features, SVCM includes a
measurement model with multiple varying coefficient functions, a jumping
surface model for each varying coefficient function, and a functional principal
component model. We develop a three-stage estimation procedure to
simultaneously estimate the varying coefficient functions and the spatial
correlations. The estimation procedure includes a fast multiscale adaptive
estimation and testing procedure to independently estimate each varying
coefficient function, while preserving its edges among different
piecewise-smooth regions. We systematically investigate the asymptotic
properties (e.g., consistency and asymptotic normality) of the multiscale
adaptive parameter estimates. We also establish the uniform convergence rate of
the estimated spatial covariance function and its associated eigenvalue and
eigenfunctions. Our Monte Carlo simulation and real data analysis have
confirmed the excellent performance of SVCM.


title: Multi Constraint Satisfying AODV routing using Fuzzy Logic

abstract:
  Mobile Networks are in need of what we call as an e-age. There have been
numerous advancements in this field and soft computing has gained roots in this
Mobile Ad-hoc Network domain. This documents studies the use of fuzzy logic
over Ad Hoc On-Demand Distance vector Routing. The evaluation of the network
using fuzzy logic over AODV has been conducted using selective criterion. Both
the terms come from two different computing environments, but when combined
together can achieve better results; when it comes to QoS based upon selective
parameters. The crisp the rules formed in fuzzy logic, better the performance
or quality will be achieved in AODV routing mechanism of MANET.


title: On orbifolds of M-Strings

abstract:
  We consider M-theory in the presence of M parallel M5-branes probing a
transverse A_{N-1} singularity. This leads to a superconformal theory with
(1,0) supersymmetry in six dimensions. We compute the supersymmetric partition
function of this theory on a two-torus, with arbitrary supersymmetry preserving
twists, using the topological vertex formalism. Alternatively, we show that
this can also be obtained by computing the elliptic genus of an orbifold of
recently studied M-strings. The resulting 2d theory is a (4,0) supersymmetric
quiver gauge theory whose Higgs branch corresponds to strings propagating on
the moduli space of SU(N)^{M-1} instantons on R^4 where the right-moving
fermions are coupled to a particular bundle.


title:
Interpreting the large amplitude X-ray variation of GRS 1915+105 and IGR
  J17091-3624 as modulations of an accretion disc

abstract:
  Using the flux resolved spectroscopy for the first time, we analyse the
RXTE/PCA data of the black hole X-ray binaries GRS 1915+105 and IGR
J17091-3624, when both sources show large amplitude, quasi-regular oscillations
in 2.0-60.0 keV X-ray light curves. For different observations, we extract
spectra during the peak (spectrally soft) and dip (spectrally hard) intervals
of the oscillation, and find that their spectra are phenomenologically complex,
requiring at least two distinct spectral components. Besides a thermal
Comptonization component, we find that the disc emission is better modelled by
an index-free multicolour disc blackbody component (p-free disc model) rather
than that from a standard accretion disc. While the peak and dip spectra are
complex, remarkably, their difference spectra constructed by treating dip
spectra as the background spectra of the peak spectra, can be modelled as a
single p-free disc component. Moreover, the variability at different
time-scales and energy bands of the peak flux level is always greater than or
equal to the variability of the dip flux level, which strengthens the
possibility that the peak flux level may be due to an independent spectral
component added to the dip one. We also verify it using joint spectral analysis
of peak and dip spectra with a variable emission component. Our result
substantiates the standard hypothesis that the oscillations are due to the
limit cycle behaviour of an unstable radiation pressure dominated inner disc.
However, in this interpretation, the flux variation of the unstable disc can be
several order of magnitudes as expected from some theoretical simulations and
need not be fine tuned to match the factor ~10 variation seen between the peak
and dip levels.


title:
Labeled Directed Acyclic Graphs: a generalization of context-specific
  independence in directed graphical models

abstract:
  We introduce a novel class of labeled directed acyclic graph (LDAG) models
for finite sets of discrete variables. LDAGs generalize earlier proposals for
allowing local structures in the conditional probability distribution of a
node, such that unrestricted label sets determine which edges can be deleted
from the underlying directed acyclic graph (DAG) for a given context. Several
properties of these models are derived, including a generalization of the
concept of Markov equivalence classes. Efficient Bayesian learning of LDAGs is
enabled by introducing an LDAG-based factorization of the Dirichlet prior for
the model parameters, such that the marginal likelihood can be calculated
analytically. In addition, we develop a novel prior distribution for the model
structures that can appropriately penalize a model for its labeling complexity.
A non-reversible Markov chain Monte Carlo algorithm combined with a greedy hill
climbing approach is used for illustrating the useful properties of LDAG models
for both real and synthetic data sets.


title: Superconformal Chern-Simons theories beyond leading order

abstract:
  We discuss higher-order corrections to superconformal invariance for a class
of N=2 supersymmetric Chern-Simons theories including the ABJM model. We argue
that corrections are inevitable for general theories in this class; but that it
is probable that any corrections are of a particular "maximally transcendental"
form.


title: Integrability in differential coverings

abstract:
  Let $\tau\colon\tilde{\mathcal{E}}\to\mathcal{E}$ be a differential covering
of a PDE $\tilde{\mathcal{E}}$ over $\mathcal{E}$. We prove that if
$\mathcal{E}$ possesses infinite number of symmetries and/or conservation laws
then $\tilde{\mathcal{E}}$ has similar properties.


title:
Review on Fragment Allocation by using Clustering Technique in
  Distributed Database System

abstract:
  Considerable Progress has been made in the last few years in improving the
performance of the distributed database systems. The development of Fragment
allocation models in Distributed database is becoming difficult due to the
complexity of huge number of sites and their communication considerations.
Under such conditions, simulation of clustering and data allocation is adequate
tools for understanding and evaluating the performance of data allocation in
Distributed databases. Clustering sites and fragment allocation are key
challenges in Distributed database performance, and are considered to be
efficient methods that have a major role in reducing transferred and accessed
data during the execution of applications. In this paper a review on Fragment
allocation by using Clustering technique is given in Distributed Database
System.


title: Numerical integration on GPUs for higher order finite elements

abstract:
  The paper considers the problem of implementation on graphics processors of
numerical integration routines for higher order finite element approximations.
The design of suitable GPU kernels is investigated in the context of general
purpose integration procedures, as well as particular example applications. The
most important characteristic of the problem investigated is the large
variation of required processor and memory resources associated with different
degrees of approximating polynomials. The questions that we try to answer are
whether it is possible to design a single integration kernel for different GPUs
and different orders of approximation and what performance can be expected in
such a case.


title:
Decomposition of EOS of Asymmetric Nuclear Matter into Different
  Spin-isospin Channels

abstract:
  We investigate the equation of state of asymmetric nuclear matter and its
isospin dependence in various spin-isospin $ST$ channels within the framework
of the Brueckner-Hartree-Fock approach extended to include a microscopic
three-body force (TBF). It is shown that the potential energy per nucleon in
the isospin-singlet T=0 channel is mainly determined by the contribution from
the tensor SD coupled channel. At high densities, the TBF effect on the
isospin-triplet T=1 channel contribution turns out to be much larger than that
on the T=0 channel contribution. At low densities around and below the normal
nuclear matter density, the isospin dependence is found to come essentially
from the isospin-singlet SD channel and the isospin-triplet T=1 component is
almost independent of isospin-asymmetry. As the density increases, the T=1
channel contribution becomes sensitive to the isospin-asymmetry and at high
enough densities its isospin-dependence may even become more pronounced than
that of the T=0 contribution. The present results may provide some microscopic
constraints for improving effective nucleon-nucleon interactions in nuclear
medium and for constructing new functionals of effective nucleon-nucleon
interaction based on microscopic many-body theories.


title: Anti-Frobenius Algebras and Associative Yang-Baxter Equation

abstract:
  Associative Yang-Baxter equation arises in different areas of algebra, e.g.,
when studying double quadratic Poisson brackets, non-abelian quadratic Poisson
brackets, or associative algebras with cyclic 2-cocycle (anti-Frobenius
algebras). Precisely, faithful representations of anti-Frobenius algebras (up
to isomorphism) are in one-to-one correspondence with skew-symmetric solutions
of associative Yang-Baxter equation (up to equivalence). Following the work of
Odesskii, Rubtsov and Sokolov and using computer algebra system Sage, we found
some constant skew-symmetric solutions of associative Yang-Baxter equation and
construct corresponded non-abelian quadratic Poisson brackets.


title:
Vectorized OpenCL implementation of numerical integration for higher
  order finite elements

abstract:
  In our work we analyze computational aspects of the problem of numerical
integration in finite element calculations and consider an OpenCL
implementation of related algorithms for processors with wide vector registers.
  As a platform for testing the implementation we choose the PowerXCell
processor, being an example of the Cell Broadband Engine (CellBE) architecture.
Although the processor is considered old for today's standards (its design
dates back to year 2001), we investigate its performance due to two features
that it shares with recent Xeon Phi family of coprocessors: wide vector units
and relatively slow connection of computing cores with main global memory. The
performed analysis of parallelization options can also be used for designing
numerical integration algorithms for other processors with vector registers,
such as contemporary x86 microprocessors.


title: A Classical Nernst Engine

abstract:
  We introduce a simple model for an engine based on the Nernst effect. In the
presence of a magnetic field, a vertical heat current can drive a horizontal
particle current against a chemical potential. For a microscopic model invoking
classical particle trajectories subject to the Lorentz force, we prove a
universal bound 3-2*sqrt(2) simeq 0.172 for the ratio between maximum
efficiency and Carnot efficiency. This bound, as the slightly lower one 1/6 for
efficiency at maximum power, can indeed be saturated for large magnetic field
and small fugacity irrespective of the aspect ratio.


title:
Phase-dependent interference fringes in the wavelength scaling of
  harmonic efficiency

abstract:
  We describe phase-dependent wavelength scaling of high-order harmonic
generation efficiency driven by ultra-short laser fields in the mid-infrared.
We employ both numerical solution of the time-dependent Schr\"{o}dinger
equation and the Strong Field Approximation to analyze the fine-scale
oscillations in the harmonic yield in the context of channel-closing effects.
We show, by varying the carrier-envelope phase, that the amplitude of these
oscillations depend strongly on the number of returning electron trajectories.
Furthermore, the peak positions of the oscillations vary significantly as a
function of the carrier-envelope phase. Owing to its practical applications, we
also study the wavelength dependence of harmonic yield in the "single-cycle"
limit, and observe a smooth variation in the wavelength scaling originating
from the vanishing fine-scale oscillations.


title: Second-Order Asymptotics for the Gaussian MAC with Degraded Message Sets

abstract:
  This paper studies the second-order asymptotics of the Gaussian
multiple-access channel with degraded message sets. For a fixed average error
probability $\varepsilon \in (0,1)$ and an arbitrary point on the boundary of
the capacity region, we characterize the speed of convergence of rate pairs
that converge to that boundary point for codes that have asymptotic error
probability no larger than $\varepsilon$. As a stepping stone to this local
notion of second-order asymptotics, we study a global notion, and establish
relationships between the two. We provide a numerical example to illustrate how
the angle of approach to a boundary point affects the second-order coding rate.
This is the first conclusive characterization of the second-order asymptotics
of a network information theory problem in which the capacity region is not a
polygon.


title: Sub-additive ergodic theorems for countable amenable groups

abstract:
  In this paper we generalize Kingman's sub-additive ergodic theorem to a large
class of infinite countable discrete amenable group actions.


title: A comparison method for heavy-tailed random variables

abstract:
  We investigate a way of comparing and classifying tails of random variables.
Our approach extends the notion of classical indices, such as exponential and
moment indices, which are widely used measuring heaviness of tail functions. A
non-parametric risk measure applicable for all heavy-tailed random variables is
obtained as a concave function that represents the decay speed of tail
function. Many key properties of the distribution of a random variable are
encoded into this function, which enables a new way to estimate tails. The
latter half of the paper is devoted to numerous examples illustrating
properties of the results developed during the first half.


title: Improving the H.E.S.S. angular resolution using the Disp method

abstract:
  The angular resolution of imaging atmospheric Cherenkov telescopes depends on
the employed event reconstruction methods. By taking the weighted average of
intersections of shower axes, the H.E.S.S. experiment achieves a 0.08 degree
angular resolution at 20 degree zenith angle with an image size cut of 160 p.e.
for sources with a spectral index of 2. However, the angular resolution
degrades to 0.14 degree at 60 degree zenith angle, due to the larger fraction
of nearly parallel images. The Disp method reduces the impact of parallel
images by including an estimation of the image displacement (disp), inferred
from the Hillas parameters, in the reconstruction procedure. By using this
technique, the angular resolution at large zenith angles can be improved by
50%. An additional cut on the estimated direction uncertainty can further
improve the angular resolution to around 0.05 degrees at the expense of a loss
of 50% of effective area. The performance of this reconstruction method on
simulated gamma-ray events and real data is presented.


title: Higgs Boson in the 4DCHM: LHC phenomenology

abstract:
  Composite Higgs models provide an elegant solution to the hierarchy problem
present in the Standard Model (SM) and give an alternative pattern leading to
the mechanism of Electro-Weak Symmetry Breaking (EWSB). We present an analysis
of the Higgs boson production and decay within a recently proposed realistic
realization of this general idea: the 4D Composite Higgs Model (4DCHM).
Comparing our results with the latest Large Hadron Collider (LHC) data we show
that the 4DCHM could provide an alternative explanation with respect to the SM
of the LHC results pointing to the discovery of a Higgs-like particle at 125
GeV.


title:
Analysis of Magnetic Field-Angle Dependent Electronic Raman Scattering
  to Probe the Superconducting Gap

abstract:
  We study the field-angle resolved electronic Raman scattering in
2-dimensional d-wave superconducting vortex states theoretically by
quasi-classical approximation, the so-called Doppler-shift method. An analytic
expression is obtained for the field angle dependence of the Raman scattering
amplitude at zero temperature. After numerical integration, we obtain the
scattering intensity for various field angles by changing the Raman shift
energy. Field-angle resolved electronic Raman scattering turns out to be an
effective method for probing unconventional superconducting gap structures. It
shows a novel phenomenon: reversal of extrema as a function of frequency
without changing temperature or field magnitude.


title: Mutual ionization in atomic collisions near the electronic threshold

abstract:
  We study mutual ionization in collisions between atomic hydrogen and helium
at impact velocities near the electronic threshold for this process (determined
by the condition that kinetic energy of an equivelocity free electron is
approximately equal to the sum of binding energies of active electrons in the
projectile and target). We show that this process is substantially influenced
by the Coulomb repulsion between the emitted electrons and that the atomic
nuclei are very strongly involved in the momentum balance along the collision
velocity.


title: Concentration phenomena in high dimensional geometry

abstract:
  The purpose of this note is to present several aspects of concentration
phenomena in high dimensional geometry. At the heart of the study is a
geometric analysis point of view coming from the theory of high dimensional
convex bodies. The topic has a broad audience going from algorithmic convex
geometry to random matrices. We have tried to emphasize different problems
relating these areas of research. Another connected area is the study of
probability in Banach spaces where some concentration phenomena are related
with good comparisons between the weak and the strong moments of a random
vector.


title:
Exact dynamics for optical coherent-state qubits subject to environment
  noise

abstract:
  We study the exact dynamics of optical qubits encoded via coherent states
with opposite phases which are interacting with an environment modeled as a
collection of simple harmonic oscillators. Making use of a coherent-state path
integral formulation, we are able to study memory effects on the dynamics of
the coherent-state qubits due to strong environment coupling. We apply this
formulation to examine the time evolution of a noisy quantum channel formed by
two coherent-state qubits that are subject to uncorrelated local environment
noises. In particular, we examine the time evolution of entanglement and
maximal teleportation fidelity of the noisy quantum channel and show that at
strong coupling, due to large feedback effects from the environment noise, it
is possible to maintain a robust quantum channel in the long-time limit if
appropriate error-correcting code is applied.


title: Does high harmonic generation conserve angular momentum?

abstract:
  High harmonic generation (HHG) is a unique and useful process in which
infrared or visible radiation is frequency up converted into the extreme
ultraviolet and x ray spectral regions. As a parametric process, high harmonic
generation should conserve the radiation energy, momentum and angular momentum.
Indeed, conservation of energy and momentum have been demonstrated. Angular
momentum of optical beams can be divided into two components: orbital and spin
(polarization). Orbital angular momentum is assumed to be conserved and
recently observed deviations were attributed to propagation effects. On the
other hand, conservation of spin angular momentum has thus far never been
studied, neither experimentally nor theoretically. Here, we present the first
study on the role of spin angular momentum in extreme nonlinear optics by
experimentally generating high harmonics of bi chromatic elliptically polarized
pump beams that interact with isotropic media. While observing that the
selection rules qualitatively correspond to spin conservation, we unequivocally
find that the process of converting pump photons into a single high-energy
photon does not conserve angular momentum, i.e. this process is not self
contained. In one regime, we numerically find that this major fundamental
discrepancy can be explained if the harmonic photons are emitted in pairs. Yet
in another regime, the ionizing electron carries the missing angular momentum.
The results presented here, apart from exploring the very foundations of HHG,
are also important for a variety of applications, as our system exhibits full
control over the harmonics polarization, from circular through elliptical to
linear polarization, without comprising the efficiency of the process. This
work paves the way for a broad range of applications with HHG, from ultrafast
circular dichroism to zepto-clocks and to attosecond quantum optics.


title: {\eta} and {\eta}' mixing from Lattice QCD

abstract:
  We present a lattice QCD computation of $\eta$ and $\eta^\prime$ masses and
mixing angles, for the first time controlling continuum and quark mass
extrapolations. The results for the eta mass 551(8)(6) MeV (first error
statistical, second systematic) and the eta' mass 1006(54)(38)(+61) MeV (third
error from our method) are in excellent agreement with experiment. Our data
show that the mixing in the quark flavour basis can be described by a single
mixing angle of 46(1)(3) degree indicating that the eta' is mainly a flavour
singlet state.


title: Shape sensitivity analysis of the Hardy constant

abstract:
  We consider the Hardy constant associated with a domain in the
$n$-dimensional Euclidean space and we study its variation upon perturbation of
the domain. We prove a Fr\'{e}chet differentiability result and establish a
Hadamard-type formula for the corresponding derivatives. We also prove a
stability result for the minimizers of the Hardy quotient. Finally, we prove
stability estimates in terms of the Lebesgue measure of the symmetric
difference of domains.


title: Probing the States of Matter in QCD

abstract:
  The ultimate aim of high energy heavy ion collisions is to study quark
deconfinement and the quark-gluon plasma predicted by quantum chromodynamics.
This requires the identification of observables calculable in QCD and
measurable in heavy ion collisions. I concentrate on three such phenomena,
related to specific features of strongly interacting matter. The observed
pattern of hadrosynthesis corresponds to that of an ideal resonance gas in
equilibrium at the pseudo-critical temperature determined in QCD. The critical
behavior of QCD is encoded in the fluctuation patterns of conserved quantum
numbers, which are presently being measured. The temperature of the quark-gluon
plasma can be determined by the dissociation patterns of the different
quarkonium states, now under study at the LHC for both charmonia and
bottomonia.


title:
Effect of grain disorientation on early fatigue crack propagation in
  face-centred-cubic polycristals: A three-dimensional dislocation dynamics
  investigation

abstract:
  Three-dimensional dislocation dynamics simulations are used to study
micro-crack interaction with the first micro-structural barrier in face-centred
cubic bi-crystals loaded in high cycle fatigue conditions. In the examined
configuration, we assumed that micro-crack transmission occurs due to surface
relief growth in the secondary grain ahead of the primary crack. This indirect
transmission mechanism is shown to strongly depend on grain-1/grain-2
disorientation. For instance, small grain disorientation induces plastic strain
localisation ahead of the crack and faster transmission through the first
barrier. Conversely, large grain-1/grain-2 disorientation induces plastic
strain spreading similar to crack tip blunting yielding slower indirect
transmission. A semi-analytical micro-model is developed based on the present
simulation results and complementary experimental observations highlighting the
original notion of first-barrier compliance. The model captures well known
experimental trends including effects of: grain-size, grain disorientation and
micro-crack retardation at the first barrier.


title: On the eigenvalues of Aharonov-Bohm operators with varying poles

abstract:
  We consider a magnetic operator of Aharonov-Bohm type with Dirichlet boundary
conditions in a planar domain. We analyse the behavior of its eigenvalues as
the singular pole moves in the domain. For any value of the circulation we
prove that the k-th magnetic eigenvalue converges to the k-th eigenvalue of the
Laplacian as the pole approaches the boundary. We show that the magnetic
eigenvalues depend in a smooth way on the position of the pole, as long as they
remain simple. In case of half-integer circulation, we show that the rate of
convergence depends on the number of nodal lines of the corresponding magnetic
eigenfunction. In addition, we provide several numerical simulations both on
the circular sector and on the square, which find a perfect theoretical
justification within our main results, together with the ones in
[Bonnaillie-No\"el, V., Helffer, B., Exp. Math. 20 (2011), no. 3, 304-322;
MR2836255 (2012i:35274)].


title:
Coherent propagation of a single photon in a lossless medium: $0\pi$
  pulse formation, slow photon, storage and retrieval in multiple temporal
  modes

abstract:
  Single-photon coherent optics represents a fundamental importance for the
investigation of quantum light-matter interactions. While most work has
considered the interaction in the steady-state regime, here we demonstrate that
a single-photon pulse shorter than any relaxation time in a medium propagates
without energy loss and is consistently transformed into a zero-area pulse. A
general analytical solution is found for photon passage through a cold ensemble
of $\Lambda$-type atoms confined inside a hollow core of a single-mode
photonic-crystal fiber. We use the robust far off-resonant Raman scheme to
control the pulse reshaping by an intense control laser beam and show that in
the case of cw control field, for exact two-photon resonance, the outgoing
photon displays an oscillating temporal distribution, which is the quantum
counterpart of a classical field ringing, while for nonzero two-photon detuning
a slow photon is produced. We demonstrate also that a train of readout control
pulses coherently recalls the stored photon in many well-separated temporal
modes, thus producing time-bin entangled single-photon states. Such states,
which allow sharing quantum information among many users, are highly demanded
for applications in long-distance quantum communication.


title:
Growth and superconducting properties of F-substituted ROBiS2 (R = La,
  Ce, Nd) single crystals

abstract:
  F-substituted ROBiS2 (R = La, Ce, Nd) superconducting single crystals with
different F concentration were grown successfully using CsCl/KCl flux. All the
obtained single crystals had a plate-like shape with a well-developed ab-plane
of 1-2 mm in size. The flux components of Cs, K, and Cl were not detected in
the obtained single crystals by electron probe microanalysis. The grown single
crystals of F-substituted LaOBiS2 and CeOBiS2 showed superconducting at about 3
K while the Tc of the F-substituted NdOBiS2 exhibited approximately 5 K. The
superconducting anisotropy of the single crystals of F-substituted LaOBiS2 and
NdOBiS2 was estimated to be 30-45 according to the effective mass model whereas
those values were 13-21 for the F-substituted CeOBiS2 single crystals. The
F-substituted CeOBiS2 single crystals exhibited magnetic order at about 7 K
that apparently coexisted with superconductivity below around 3 K.


title:
A structure for quasars under the scope of polarisation I. The
  UV/optical polarisation dichotomy of type-1 and type-2 AGN

abstract:
  We present UV/optical spectropolarimetric modelling of the
phenomenologically-based structure for quasars proposed by Elvis (2000). In
this first paper of a series, we explore the continuum polarisation emerging
from radiatively accelerated and bent winds that were vertically launched from
the accretion disc in an active galactic nucleus (AGN). We simulate the
radiative transfer occurring in Thomson scattering and dust extinction media
over a range of morphological parameters and optical depths of the wind. We
demonstrate that the wind geometry proposed by Elvis with a
phenomenologically-derived bending angle of theta = 60deg still underestimates
the observed optical polarisation percentage of type-1 and type-2 AGN and does
not yet reproduce the expected dichotomy of the polarisation position angle. To
recover the observed polarisation properties, a smaller bending angle and some
amount of dust shielding in the equatorial region should be considered. A
two-phase outflow is found to generate both the observed polarisation dichotomy
and acceptable levels of polarisation degree if the wind has a bending angle
theta = 45deg, and the conical shells have a half-openingangle of 3deg <
delta_theta < 10deg. The absorbing dust column at the wind base should be in
the range of 1 < tau_dust < 4 (tau being integrated over 2000 - 8000 Angs).
Straightforward observational tests from spectropolarimetry and from
determining the number density of different AGN types can be performed to
further constrain the wind geometry.


title: The period function and the harmonic balance method

abstract:
  In this paper we consider several families of potential non-isochronous
systems and study their associated period functions. Firstly, we prove some
properties of these functions, like their local behavior near the critical
point or infinity, or their global monotonicity. Secondly, we show that these
properties are also present when we approach to the same questions using the
Harmonic Balance Method.


title:
Firing-rate, symbolic dynamics and frequency dependence in periodically
  driven spiking models: a piecewise-smooth approach

abstract:
  In this work we consider a periodically forced generic integrate-and-fire
model with a unique attracting equilibrium in the subthreshold dynamics and
study the dependence of the firing-rate on the frequency of the drive. In an
earlier study we have obtained rigorous results on the bifurcation structure in
such systems, with emphasis on the relation between the firing-rate and the
rotation number of the existing periodic orbits. In this work we study how
these bifurcation structures behave upon variation of the frequency of the
input. This allows us to show that the dependence of the firing-rate on
frequency of the drive follows a devil's staircase with non-monotonic steps and
that there is an optimal response in the whole frequency domain. We also
characterize certain bounded frequency windows in which the firing-rate
exhibits a bell-shaped envelope with a global maximum.


title:
Graded Quantization: Democracy for Multiple Descriptions in Compressed
  Sensing

abstract:
  The compressed sensing paradigm allows to efficiently represent sparse
signals by means of their linear measurements. However, the problem of
transmitting these measurements to a receiver over a channel potentially prone
to packet losses has received little attention so far. In this paper, we
propose novel methods to generate multiple descriptions from compressed sensing
measurements to increase the robustness over unreliable channels. In
particular, we exploit the democracy property of compressive measurements to
generate descriptions in a simple manner by partitioning the measurement vector
and properly allocating bit-rate, outperforming classical methods like the
multiple description scalar quantizer. In addition, we propose a modified
version of the Basis Pursuit Denoising recovery procedure that is specifically
tailored to the proposed methods. Experimental results show significant
performance gains with respect to existing methods.