title:
How adaptation currents change threshold, gain and variability of
  neuronal spiking

abstract:
  Many types of neurons exhibit spike rate adaptation, mediated by intrinsic
slow $\mathrm{K}^+$-currents, which effectively inhibit neuronal responses. How
these adaptation currents change the relationship between in-vivo like
fluctuating synaptic input, spike rate output and the spike train statistics,
however, is not well understood. In this computational study we show that an
adaptation current which primarily depends on the subthreshold membrane voltage
changes the neuronal input-output relationship (I-O curve) subtractively,
thereby increasing the response threshold. A spike-dependent adaptation current
alters the I-O curve divisively, thus reducing the response gain. Both types of
adaptation currents naturally increase the mean inter-spike interval (ISI), but
they can affect ISI variability in opposite ways. A subthreshold current always
causes an increase of variability while a spike-triggered current decreases
high variability caused by fluctuation-dominated inputs and increases low
variability when the average input is large. The effects on I-O curves match
those caused by synaptic inhibition in networks with asynchronous irregular
activity, for which we find subtractive and divisive changes caused by external
and recurrent inhibition, respectively. Synaptic inhibition, however, always
increases the ISI variability. We analytically derive expressions for the I-O
curve and ISI variability, which demonstrate the robustness of our results.
Furthermore, we show how the biophysical parameters of slow
$\mathrm{K}^+$-conductances contribute to the two different types of adaptation
currents and find that $\mathrm{Ca}^{2+}$-activated $\mathrm{K}^+$-currents are
effectively captured by a simple spike-dependent description, while
muscarine-sensitive or $\mathrm{Na}^+$-activated $\mathrm{K}^+$-currents show a
dominant subthreshold component.


title: Reverse Triangle Inequalities for Potentials

abstract:
  We study the reverse triangle inequalities for suprema of logarithmic
potentials on compact sets of the plane. This research is motivated by the
inequalities for products of supremum norms of polynomials. We find sharp
additive constants in the inequalities for potentials, and give applications of
our results to the generalized polynomials.
  We also obtain sharp inequalities for products of norms of the weighted
polynomials $w^nP_n, deg(P_n)\le n,$ and for sums of suprema of potentials with
external fields. An important part of our work in the weighted case is a Riesz
decomposition for the weighted farthest-point distance function.


title: A New Strategy of Cost-Free Learning in the Class Imbalance Problem

abstract:
  In this work, we define cost-free learning (CFL) formally in comparison with
cost-sensitive learning (CSL). The main difference between them is that a CFL
approach seeks optimal classification results without requiring any cost
information, even in the class imbalance problem. In fact, several CFL
approaches exist in the related studies, such as sampling and some
criteria-based pproaches. However, to our best knowledge, none of the existing
CFL and CSL approaches are able to process the abstaining classifications
properly when no information is given about errors and rejects. Based on
information theory, we propose a novel CFL which seeks to maximize normalized
mutual information of the targets and the decision outputs of classifiers.
Using the strategy, we can deal with binary/multi-class classifications
with/without abstaining. Significant features are observed from the new
strategy. While the degree of class imbalance is changing, the proposed
strategy is able to balance the errors and rejects accordingly and
automatically. Another advantage of the strategy is its ability of deriving
optimal rejection thresholds for abstaining classifications and the
"equivalent" costs in binary classifications. The connection between rejection
thresholds and ROC curve is explored. Empirical investigation is made on
several benchmark data sets in comparison with other existing approaches. The
classification results demonstrate a promising perspective of the strategy in
machine learning.


title: Means of algebraic numbers in the unit disk

abstract:
  Schur studied limits of the arithmetic means $s_n$ of zeros for polynomials
of degree $n$ with integer coefficients and simple zeros in the closed unit
disk. If the leading coefficients are bounded, Schur proved that
$\limsup_{n\to\infty} |s_n| \le 1-\sqrt{e}/2.$ We show that $s_n \to 0$, and
estimate the rate of convergence by generalizing the Erd\H{o}s-Tur\'an theorem
on the distribution of zeros.


title:
Pushing the limits of the Gaia space mission by analyzing galaxy
  morphology

abstract:
  The ESA Gaia mission, to be launched during 2013, will observe billions of
objects, among which many galaxies, during its scanning of the sky. This will
provide a large space-based dataset with unprecedented spatial resolution.
Because of its natural Galactic and Astrometric priority, Gaia's observational
strategy was optimized for point sources. Nonetheless, it is expected that 10^6
sources will be extragalactic, and a large portion of them will be angularly
small galaxies. Although the mission was designed for point sources, a
dedicated analysis of the raw data will allow the recovery of morphology of
those objects at a 0.2" level. This may constitute a unique all-sky survey of
such galaxies. We describe the conceptual design of the method we created for
performing the morphological analysis of these objects as well as first results
obtained from data simulations of low-resolution, highly binned, satellite
data. Based on the obtained results we conclude that it is possible to push the
limits of the Gaia space mission by analyzing galaxy morphology. (Abridged)


title: Uniform continuity of POVMs

abstract:
  Recently a characterization of uniformly continuous POVMs and a necessary
condition for a uniformly continuous POVM $F$ to have the norm-1 property have
been provided. Moreover it was proved that in the commutative case, uniform
continuity corresponds to the existence of a Feller Markov kernel. We apply
such results to the analysis of some relevant physical examples; i.e., the
phase space localization observables, the unsharp phase observable and the
unsharp number observable of which we study the uniform continuity, the norm-1
property and the existence of a Feller Markov kernel.


title: Distribution of algebraic numbers

abstract:
  Schur studied limits of the arithmetic means $A_n$ of zeros for polynomials
of degree $n$ with integer coefficients and simple zeros in the closed unit
disk. If the leading coefficients are bounded, Schur proved that
$\limsup_{n\to\infty} |A_n| \le 1-\sqrt{e}/2.$ We show that $A_n \to 0$, and
estimate the rate of convergence by generalizing the Erd\H{o}s-Tur\'an theorem
on the distribution of zeros. As an application, we show that integer
polynomials have some unexpected restrictions of growth on the unit disk.
  Schur also studied problems on means of algebraic numbers on the real line.
When all conjugate algebraic numbers are positive, the problem of finding the
sharp lower bound for $\liminf_{n\to\infty} A_n$ was developed further by
Siegel and others. We provide a solution of this problem for algebraic numbers
equidistributed in subsets of the real line.
  Potential theoretic methods allow us to consider distribution of algebraic
numbers in or near general sets in the complex plane. We introduce the
generalized Mahler measure, and use it to characterize asymptotic
equidistribution of algebraic numbers in arbitrary compact sets of capacity
one. The quantitative aspects of this equidistribution are also analyzed in
terms of the generalized Mahler measure.


title:
Importance of static quadrupole moments for determining collective
  aspects of nuclear structure: N=Z calculations with four and eight valence
  particles

abstract:
  In this work we look at the low lying nuclear structure of several N=Z nuclei
residing between the doubly magic nucei ^{40} Ca and ^{100} Sn. Using large
shell model codes we calculate and discuus the systematics of enegies. We show
energy levels, B(E2)'s, static quadrupule moments and g factors. In all cases
we compare the results of 2 different interactions which yield significanly
different occupation numbers. We compare with the simplest versions of the
rotational and vibrational models. By examinnig B(E2)'s and static quadrupole
moments we make associations with collective models find that in the model
space here considered ,{}^{88} Ru is oblate . The quadruple moment of ^{92} Pd
is very small consistent with the vibrational model.


title:
Speaker Independent Continuous Speech to Text Converter for Mobile
  Application

abstract:
  An efficient speech to text converter for mobile application is presented in
this work. The prime motive is to formulate a system which would give optimum
performance in terms of complexity, accuracy, delay and memory requirements for
mobile environment. The speech to text converter consists of two stages namely
front-end analysis and pattern recognition. The front end analysis involves
preprocessing and feature extraction. The traditional voice activity detection
algorithms which track only energy cannot successfully identify potential
speech from input because the unwanted part of the speech also has some energy
and appears to be speech. In the proposed system, VAD that calculates energy of
high frequency part separately as zero crossing rate to differentiate noise
from speech is used. Mel Frequency Cepstral Coefficient (MFCC) is used as
feature extraction method and Generalized Regression Neural Network is used as
recognizer. MFCC provides low word error rate and better feature extraction.
Neural Network improves the accuracy. Thus a small database containing all
possible syllable pronunciation of the user is sufficient to give recognition
accuracy closer to 100%. Thus the proposed technique entertains realization of
real time speaker independent applications like mobile phones, PDAs etc.


title: Structures in the Planck map of the CMB

abstract:
  We present the results of the quest for ring-type structures on the maps
observed by the Planck satellite.


title:
Self-consistent Gutzwiller study of bcc Fe: interplay of ferromagnetic
  order and kinetic energy

abstract:
  The Gutzwiller technique has long been known as a method to include
correlations in electronic structure calculations. Here we implement an
ab-initio Gutzwiller+LDA calculation, and apply it to a classic problem, the
ferromagnetism of bulk bcc Fe, whose nature has attracted recent interest. In
the conventional Stoner-Wohlfarth model, the ferromagnetic ordering of iron
sets in so that the electrons can reduce their mutual Coulomb repulsion at the
extra cost of some increase of electron kinetic energy. Density functional
theory within the spin polarized local density approximation (LDA) has long
supported that picture, showing that ferromagnetic alignment causes band
narrowing and a corresponding wavefunction localization, whence a kinetic
energy increase. However, because of its inadequate treatment of strong
intra-site correlations for localized d orbitals, LDA cannot be relied upon,
particularly when it comes to separately describing fine potential and kinetic
energy imbalances. With ab-initio Gutzwiller+LDA, we indeed find that the
effect of correlations is to dramatically reverse the balance, the
ferromagnetic ordering of Fe in fact causing a decrease of kinetic energy, at
the cost of some increase of potential energy. The underlying physical
mechanism, foreshadowed long ago by Goodenough and others, and more recently
supported by LDA+DMFT calculations, is that correlations cause eg and t2g 3d
orbitals to behave very differently. Weakly dispersive eg states are
spin-polarized and almost localized, while, more than half filled, the t2g are
broad band, fully delocalized states. Owing to intra-atomic Hund's rule
exchange which aligns eg and t2g spins, the propagation of itinerant t2g holes
is only allowed when different atomic spins are ferromagnetically aligned. We
thus conclude that double exchange is at work already in the most popular
ferromagnetic metal.


title: Full counting statistics of persistent current

abstract:
  We develop a method for calculation of charge transfer statistics of
persistent current in nanostructures in terms of the cumulant generating
function (CGF) of transferred charge. We consider a simply connected
one-dimensional system (a wire) and develop a procedure for the calculation of
the CGF of persistent currents when the wire is closed into a ring via a weak
link. For the non-interacting system we derive a general formula in terms of
the two-particle Green's functions. We show that, contrary to the conventional
tunneling contacts, the resulting cumulant generating function has a doubled
periodicity as a function of the counting field. We apply our general formula
to short tight-binding chains and show that the resulting CGF perfectly
reproduces the known evidence for the persistent current. Its second cumulant
turns out to be maximal at the switching points and vanishes identically at
zero temperature. Furthermore, we apply our formalism for a computation of the
charge transfer statistics of genuinely interacting systems. First we consider
a ring with an embedded Anderson impurity and employing a self-energy
approximation find an overall suppression of persistent current as well as of
its noise. Finally, we compute the charge transfer statistics of a double
quantum dot system in the deep Kondo limit using an exact analytical solution
of the model at the Toulouse point. We analyze the behaviour of the resulting
cumulants and compare them with those of a noninteracting double quantum dot
system and find several pronounced differences, which can be traced back to
interaction effects.


title:
Detecting interactions between dark matter and photons at high energy
  $e^+e^-$ colliders

abstract:
  We investigate the sensitivity to the effective operators describing
interactions between dark matter particles and photons at future high energy
$e^+e^-$ colliders via the $\gamma+ \slashed{E}$ channel. Such operators could
be useful to interpret the potential gamma-ray line signature observed by the
Fermi-LAT. We find that these operators can be further tested at $e^+ e^-$
colliders by using either unpolarized or polarized beams. We also derive a
general unitarity condition for $2 \to n$ processes and apply it to the dark
matter production process $e^+e^-\to\chi\chi\gamma$.


title: Numerical simulation of quadratic BSDEs

abstract:
  This article deals with the numerical approximation of Markovian backward
stochastic differential equations (BSDEs) with generators of quadratic growth
with respect to $z$ and bounded terminal conditions. We first study a slight
modification of the classical dynamic programming equation arising from the
time-discretization of BSDEs. By using a linearization argument and BMO
martingales tools, we obtain a comparison theorem, a priori estimates and
stability results for the solution of this scheme. Then we provide a control on
the time-discretization error of order $\frac{1}{2}-\varepsilon$ for all
$\varepsilon>0$. In the last part, we give a fully implementable algorithm for
quadratic BSDEs based on quantization and illustrate our convergence results
with numerical examples.


title: Neutrino experiments in Physics Department of Rome Sapienza University

abstract:
  This paper describes the history of experimental neutrino physics in the
physics department of Rome Sapienza University


title: Behavior of odd-even mass staggering around 132Sn

abstract:
  We have performed shell-model calculations of binding energies of nuclei
around $^{132}$Sn. The main aim of our study has been to find out if the
behavior of odd-even staggering across N=82 is explainable in terms of the
shell model. In our calculations, we have employed realistic low-momentum
two-body effective interactions derived from the CD-Bonn nucleon-nucleon
potential that have already proved quite successful in describing the
spectroscopic properties of nuclei in the $^{132}$Sn region. Comparison shows
that our results fully explains the trend of the experimental staggering.


title: Self-Assembled Nanostructure Formation in Chemical Vapor Deposition

abstract:
  When thin films are grown on a substrate by chemical vapor deposition, the
evolution of the first deposited layers may be described, on mesoscopic scales,
by dynamical models of the reaction-diffusion type. For monoatomic layers, such
models describe the evolution of atomic coverage due to the combined effect of
reaction terms representing adsorption-desorption and chemical processes and
nonlinear diffusion terms which are of the Cahn-Hilliard type. This combination
may lead, below a critical temperature, to the instability of uniform deposited
layers. This instability triggers the formation of nanostructures corresponding
to regular spatial variations of substrate coverage. Patterns wavelengths and
symmetries are selected by dynamical variables and not by variational
arguments. According to the balance between reaction- and diffusion-induced
nonlinearities, a succession of self-assembled structures including hexagonal
arrays of dots, stripes and localized structures of various types may be
obtained. These structures may initiate different types of growth mechanisms,
including Volmer-Weber and Frank-Van der Merwe type of growth. The relevance of
this approach to the study of different types of deposited monolayers is
discussed.


title: Study of Higgs Production in Fermionic Decay Channels at CMS

abstract:
  In these proceedings to the LHCP conference 2013 results are presented on the
study of the Higgs-like particle at a mass of 125 GeV decaying into final
states consisting of either $\tau^+\tau^-$, or a $b\bar{b}$ quark pair, based
on the full statistics of about 24 fb$^{-1}$, collected in 2011 and 2012 at 7
and 8 TeV respectively with the CMS experiment at the Large Hadron Collider.
Leptonic and hadronic decay channels for the $\tau$-lepton are included in the
search. Different production channels namely gluon fusion, vector boson fusion
(VBF) and associated production with W/Z bosons have been studied
$\tau^+\tau^-$ final states. The $b\bar{b}$ decay channel is studied in VBF as
well as in associated production with W/Z and top quarks.


title: Stable reconstruction of generalized impedance boundary conditions

abstract:
  We are interested in the identification of a Generalized Impedance Boundary
Condition from the far--fields created by one or several incident plane waves
at a fixed frequency. We focus on the particular case where this boundary
condition is expressed with the help of a second order surface operator: the
inverse problem then amounts to retrieve the two functions $\lambda$ and $\mu$
that define this boundary operator. We first derive a global Lipschitz
stability result for the identification of $\ld$ or $\mu$ from the far--field
for bounded piecewise constant impedance coefficients and we give a new type of
stability estimate when inexact knowledge of the boundary is assumed. We then
introduce an optimization method to identify $\lambda$ and $\mu$, using in
particular a $H^1$-type regularization of the gradient. We lastly show some
numerical results in two dimensions, including a study of the impact of some
various parameters, and by assuming either an exact knowledge of the shape of
the obstacle or an approximate one.


title: Reply to Hartig et al. [arXiv:1305.3544]: The "true model" myth

abstract:
  We have shown that commonly used model-fitting methods fail when the
underlying ecological system is chaotic. Importantly, Hartig & Dormann
[arXiv:1305.3544] suggest an alternative method that is able to overcome this
problem for the logistic model when the "true model" is known. This is
encouraging, however the more relevant test is of the method when the "true
model" is unknown, as it always is for real ecosystems. By making a small
modification to the "true model," we find that the suggested method provides
inaccurate forecasts and severely biased estimates of the ecological dynamics.
In contrast, a model-free approach is able to provide accurate forecasts and a
useful foundation for ecological understanding without the burdensome
assumption of a "true model."


title:
Appearance Descriptors for Person Re-identification: a Comprehensive
  Review

abstract:
  In video-surveillance, person re-identification is the task of recognising
whether an individual has already been observed over a network of cameras.
Typically, this is achieved by exploiting the clothing appearance, as classical
biometric traits like the face are impractical in real-world video surveillance
scenarios. Clothing appearance is represented by means of low-level
\textit{local} and/or \textit{global} features of the image, usually extracted
according to some part-based body model to treat different body parts (e.g.
torso and legs) independently. This paper provides a comprehensive review of
current approaches to build appearance descriptors for person
re-identification. The most relevant techniques are described in detail, and
categorised according to the body models and features used. The aim of this
work is to provide a structured body of knowledge and a starting point for
researchers willing to conduct novel investigations on this challenging topic.


title:
Measurement of jet shapes in top pair events at sqrt(s) = 7 TeV using
  the ATLAS detector

abstract:
  A measurement of jet shapes in top-quark pair events using 1.8 fb(-1) of
sqrt(s) = 7 TeV pp collision data recorded by the ATLAS detector at the LHC is
presented. Samples of top-quark pair events are selected in both the
single-lepton and dilepton final states. The differential and integrated shapes
of the jets initiated by bottom-quarks from the top-quark decays are compared
with those of the jets originated by light-quarks from the hadronic W-boson
decays in the single-lepton channel. The light-quark jets are found to have a
narrower distribution of the momentum flow inside the jet area than b-quark
jets.


title:
Stringent limits on top-quark compositeness from top anti-top production
  at the Tevatron and the LHC

abstract:
  If the top quark is a composite state made out of some constituents, its
interaction with the gluon will be modified. We introduce the leading effective
operators that contribute to the radius and anomalous magnetic moment of the
top quark and study their effect on the cross section for top anti-top
production at the Tevatron and the LHC. Current measurements of the cross
sections set a stringent limit on the scale of compositeness. This limit is
comparable to similar limits obtained for light quarks and those from
electroweak precision measurements. It can be used to constrain the parameter
space of some composite Higgs models.


title:
A Stochastically Forced Time Delay Solar Dynamo Model: Self-Consistent
  Recovery from a Maunder-like Grand Minimum Necessitates a Mean-Field Alpha
  Effect

abstract:
  Fluctuations in the Sun's magnetic activity, including episodes of grand
minima such as the Maunder minimum have important consequences for space and
planetary environments. However, the underlying dynamics of such extreme
fluctuations remain ill-understood. Here we use a novel mathematical model
based on stochastically forced, non-linear delay differential equations to
study solar cycle fluctuations, in which, time delays capture the physics of
magnetic flux transport between spatially segregated dynamo source regions in
the solar interior. Using this model we explicitly demonstrate that the
Babcock-Leighton poloidal field source based on dispersal of tilted bipolar
sunspot flux, alone, can not recover the sunspot cycle from a grand minimum. We
find that an additional poloidal field source effective on weak fields--the
mean-field alpha-effect driven by helical turbulence--is necessary for
self-consistent recovery of the sunspot cycle from grand minima episodes.


title: On the isospin 0 and 1 resonances from $\pi \Sigma$ photoproduction data

abstract:
  Recently we presented a successful strategy to extract the position of the
two $\Lambda(1405)$ poles from experimental photoproduction data on the $\gamma
p \to K^+ \pi^0 \Sigma^0 $ reaction at Jefferson Lab. Following a similar
strategy, we extend the previous method to incorporate also the isospin 1
component which allows us to consider in addition the experimental data on
$\gamma p \to K^+ \pi^\pm \Sigma^\mp$. The idea is based on considering a
production mechanism as model independent as possible and implementing the
final state interaction of the final meson-baryon pair based on small
modifications of the unitary chiral perturbation theory amplitudes. Good fits
to the data are obtained with this procedure, by means of which we can also
predict the cross sections for the $K^- p \to \bar K N$, $\pi \Sigma$,
$\pi\Lambda$ reactions for the different charge channels. Besides the two poles
found for the $\Lambda(1405)$ resonance, we discuss the possible existence of
an isospin 1 resonance in the vicinity of the $\bar K N$ threshold.


title: On Eigenvectors of Random Band Matrices with Large Band

abstract:
  We study random, symmetric $N \times N$ band matrices with a band of size $W$
and Bernoulli random variables as entries. This interpolates between nearest
neighbour interaction $W = 1$ and Wigner matrices $W = N$. Eigenvectors are
known to be localized for $W \ll N^{1/8}$, delocalized for $W \gg N^{4/5}$ and
it is conjectured that the transition for the bulk occurs at $W \sim N^{1/2}$.
Eigenvalues in the spectral edge change their behavior at $W \sim N^{5/6}$ but
nothing is known about the associated eigenvectors. We show that up to $W \ll
N^{5/7}$ any random matrix has with large probability some eigenvectors in the
spectral edge, which either exhibit mass concentration or interact strongly on
a small scale.


title:
Angle-resolved photoemission spectroscopy study on iron-based
  superconductors

abstract:
  Angle-resolved photoemission spectroscopy (ARPES) has played an important
role in determining the band structure and the superconducting gap structure of
iron-based superconductors. Here from the ARPES perspective, we briefly review
the main results from our group in the recent years on the iron-based
superconductors and their parent compounds, and depict our current
understanding on the antiferromagnetism and superconductivity in these
materials.


title: Proton Decay and the Origin of Quark and Lepton Mixing

abstract:
  It was recently proposed that all flavor mixing has a single source, namely
the mixing of the three quark and lepton families with "extra" vectorlike
fermions in 5 + 5-bar multiplets of SU(5). This was shown to lead to several
testable predictions including neutrino masses and CP-violating phases. Here it
is shown that the mixing angles within grand unified fermion multiplets are
also predicted. Proton decay branching ratios would thus give several
independent tests of the model. Certain model parameters could be determined
independently from the quark and lepton spectrum and from proton decay.


title: DNStamp: Short-lived Trusted Timestamping

abstract:
  Trusted timestamping consists in proving that certain data existed at a
particular point in time. Existing timestamping methods require either a
centralized and dedicated trusted service or the collaboration of other
participants using the timestamping service. We propose a novel trusted
timestamping scheme, called DNStamp, that does not require a dedicated service
nor collaboration between participants. DNStamp produces shortlived timestamps
with a validity period of several days. The generation and verification
involves a large number of Domain Name System cache resolvers, thus removing
any single point of failure and any single point of trust. Any host with
Internet access may request or verify a timestamp, with no need to register to
any timestamping service. We provide a full description and analysis of
DNStamp. We analyze the security against various adversaries and show
resistance to forward-dating, back-dating and erasure attacks. Experiments with
our implementation of DNStamp show that one can set and then reliably verify
timestamps even under continuous attack conditions.


title: Prisoners' Dilemma in Presence of Collective Dephasing

abstract:
  We quantize prisoner dilemma in presence of collective dephasing with
dephasing rate $\gamma $. It is shown that for two parameters set of strategies
$Q\otimes Q$ is Nash equilibrium below a cut-off value of time. Beyond this
cut-off it bifurcates into two new Nash equilibria $Q\otimes D$ and $D\otimes
Q$. Furthermore for maximum value of decoherence \ $C\otimes D$ and $D\otimes
C$ also become Nash equilibria. At this stage the game has four Nash
equilibria. On the other hand for three parameters set of strategies there is
no pure strategy Nash equilibrium however there is mixed strategy (non unique)
Nash equilibrium that is not affected by collective dephasing..


title:
On the fractional stochastic Navier-Stokes equations on the torus and on
  bounded domains

abstract:
  In this work, we introduce and study the well-posedness of the
multidimensional fractional stochastic Navier-Stokes equations on bounded
domains and on the torus (Briefly dD-FSNSE). We prove the existence of a
martingale solution for the general regime. We establish the uniqueness in the
case a martingale solution enjoys a condition of Serrin's type on the
fractional Sobolev spaces. If an $L^2-$ local weak (strong in probability)
solution exists and enjoys conditions of Beale-Kato-Majda type, this solution
is global and unique. These conditions are automatically satisfied for the
2D-FSNSE on the torus if the initial data has $ H^1-$regularity and the
diffusion term satisfies growth and Lipschitz conditions corresponding to $
H^1-$spaces. The case of 2D-FSNSE on the torus is studied separately. In
particular, we established thresholds for the global existence, uniqueness,
space and time regularities of the weak (strong in probability) solutions in
the subcritical regime.


title: Count Models Based on Weibull Interarrival Times

abstract:
  In this paper, we introduce a generalized model for count data based upon an
assumed Weibull interarrival process that nests the Poisson and negative
binomial models as special cases. In addition, we demonstrate that this new
Weibull count model can model both over and underdispersed count data, allow
covariates to be introduced in a straightforward manner through the hazard
function, and be computed in standard software.


title:
Development and results from a survey on students views of experiments
  in lab classes and research

abstract:
  The Colorado Learning Attitudes about Science Survey for Experimental Physics
(E-CLASS) was developed as a broadly applicable assessment tool for
undergraduate physics lab courses. At the beginning and end of the semester,
the E-CLASS assesses students views about their strategies, habits of mind, and
attitudes when doing experiments in lab classes. Students also reflect on how
those same strategies, habits-of-mind, and attitudes are practiced by
professional researchers. Finally, at the end of the semester, students reflect
on how their own course valued those practices in terms of earning a good
grade. In response to frequent calls to transform laboratory curricula to more
closely align it with the skills and abilities needed for professional
research, the E-CLASS is a tool to assess students' perceptions of the gap
between classroom laboratory instruction and professional research. The E-CLASS
has been validated and administered in all levels of undergraduate physics
classes. To aid in its use as a formative assessment tool, E-CLASS provides all
participating instructors with a detailed feedback report. Example figures and
analysis from the report are presented to demonstrate the capabilities of the
E-CLASS. The E-CLASS is actively administered through an online interface and
all interested instructors are invited to administer the E-CLASS their own
classes and will be provided with a summary of results at the end of the
semester.


title:
Kane-Pumplin-Repko Factorization: its application to precision
  measurements of transverse spin asymmetries and to the study of TMD evolution

abstract:
  This article presents a summary of overlapping presentations by the author to
the QCD Evolution 2013 Workshop and to the Opportunities for Polarized Physics
at Fermilab Workshop. It contains an introduction to the concept of
Kane-Pumplin-Repko (KPR) factorization and descibes how this concept can be
used in the analysis of high-precision measurements of parity-conserving
transverse single-spin asymmetries. The discussion demonstrates that such
measurements can not only probe directly for specific mechanisms that enhance
our fundamental understanding of nonperturbative QCD but, because transverse
spin asymmetries are unambiguously perameterized by a spin-directed momentum
shift, such measurements can also be used to calibrate other phenomenological
applications of transverse momentum dependent distributions (TMD's) and of TMD
evolution. The calibration supplied by these measurements can thus enable the
use of TMD factorization for the exploration of a broad range of other aspects
of hadronic structure.


title:
Time-dependent density-functional theory for real-time electronic
  dynamics on material surfaces

abstract:
  The real-time electronic dynamics on material surfaces is critically
important to a variety of applications. However, their simulations have
remained challenging for conventional methods such as the time-dependent
density-functional theory (TDDFT) for isolated and periodic systems. By
extending the applicability of TDDFT to systems with open boundaries, we
achieve accurate atomistic simulations of real-time electronic response to
local perturbations on material surfaces. Two prototypical scenarios are
exemplified: the relaxation of an excess electron on graphene surface, and the
electron transfer across the molecule-graphene interface. Both the transient
and long-time asymptotic dynamics are validated, which accentuates the
fundamental importance and unique usefulness of an open-system TDDFT approach.
The simulations also provide insights into the characteristic features of
temporal electron evolution and dissipation on surfaces of bulk materials.


title: What size halos do local LIRGs live in?

abstract:
  This work investigates the preferred environment of local Luminous IR
Galaxies (LIRGs) in terms of the host halos that they inhabit, and in
comparison to a control galaxy sample. The LIRGs are drawn from the IRAS Point
Source Catalogue redshift survey (PSCz), while the control sample is drawn from
the 2MASS redshift survey (2MRS). A friends-of-friends algorithm was run on the
2MRS sample to identify galaxies living in the same dark matter halos and the
PSCz galaxies were then associated with these identified halos. We show that
the relative probability of finding local LIRGs with respect to 2MASS galaxies
is largest in approximately group size halos (Mhalo~10^13M_sun), and declines
both in the cluster regime and in smaller halos. This confirms, using a
different technique than in previous work, that local LIRGs are indeed more
abundant in group environments than elsewhere. We also find a trend between the
LIR values of LIRGs and their location within their host dark matter halos,
such that the average location of LIRGs with high IR luminosity is closer to
the halo centre than for low IR luminosity galaxies. Moreover, this trend does
not seem to depend on halo mass.


title:
Rigidity results, inverse curvature flows and Alexandrov-Fenchel type
  inequalities in the sphere

abstract:
  We prove a rigidity result in the sphere which allows us to generalize a
result about smooth convex hypersurfaces in the sphere by Do Carmo-Warner to
convex $C^2$-hypersurfaces. We apply these results to prove
$C^{1,\beta}$-convergence of inverse F-curvature flows in the sphere to an
equator in \mathbb{S}^{n+1} for embedded, closed, strictly convex initial
hypersurfaces. The result holds for large classes of curvature functions
including the mean curvature and arbitrary powers of the Gauss curvature. We
use this result to prove Alexandrov-Fenchel type inequalities in the sphere.


title: Gradings of positive rank on simple Lie algebras

abstract:
  We complete the classification of positive rank gradings on Lie algebras of
simple algebraic groups over an algebraically closed field k whose
characteristic is zero or not too small, and we determine the little Weyl
groups in each case. We also classify the stable gradings and prove Popov's
conjecture on the existence of a Kostant section.


title: Bottonium in QCD at finite temperature

abstract:
  Vector ($\Upsilon$) and pseudoscalar ($\eta_b$) bottonium ground states are
studied at finite temperature in the framework of thermal Hilbert moment QCD
sum rules. The mass, the onset of perturbative QCD in the complex squared
energy plane, $s_0$, the leptonic decay constant, and the total width are
determined as a function of the temperature. Results in both channels show very
little temperature dependence of the mass and of $s_0$, in line with
expectations. However, the width and the leptonic decay constant exhibit a very
strong $T$-dependence. The former increases with increasing temperature, as in
the case of light- and heavy-light-quark systems, but close to the critical
temperature, $T_c$, and for $T/T_c \simeq 0.9$ it drops dramatically
approaching its value at T=0, as obtained recently in this framework for
charmonium states. The leptonic decay constant is basically a monotonically
increasing function of the temperature, also as obtained in the charmonium
channel . These results are interpreted as the survival of these bottonium
states above $T_c$, in line with lattice QCD results.


title:
How fast increasing powers of a continuous random variable converge to
  Benford's law

abstract:
  It is known that increasing powers of a continuous random variable converge
in distribution to Benford's law as the exponent approaches infinity. The rate
of convergence has been estimated using Fourier analysis, but we present an
elementary method, which is easier to apply and provides a better estimation in
the widely studied case of a uniformly distributed random variable.


title:
Exact dynamics and thermalization of an open bosonic quantum system in
  presence of a quantum phase transition induced by the environment

abstract:
  We derive the exact out-of-equilibrium Wigner function of a bosonic mode
linearly coupled to a bosonic bath of arbitrary spectral density. Our solution
does not rely on any master equation approach and it therefore also correctly
describes a bosonic mode which is initially entangled with its environment. It
has been recently suggested that non-Markovian quantum effects lead to dissi-
pationless dynamics in the case of a strong coupling to a bath whose spectral
density has a support bounded from below. We show in this work that such a
system undergoes a quantum phase transi- tion at some critical bath coupling
strength. The apparent dissipationless dynamics then correspond to the
relaxation towards the new ground-state.


title: ATLAS Upgrade Instrumentation in the US

abstract:
  Planned upgrades of the LHC over the next decade should allow the machine to
operate at a center of mass energy of 14 TeV with instantaneous luminosities in
the range 5--7e34 cm^-2 s^-1. With these parameters, ATLAS could collect 3,000
fb^-1 of data in approximately 10 years. However, the conditions under which
this data would be acquired are much harsher than those currently encountered
at the LHC. For example, the number of proton-proton interactions per bunch
crossing will rise from the level of 20--30 per 50 ns crossing observed in 2012
to 140--200 every 25 ns. In order to deepen our understanding of the newly
discovered Higgs boson and to extend our searches for physics beyond that new
particle, the ATLAS detector, trigger, and readout will have to undergo
significant upgrades. In this whitepaper we describe R&D necessary for ATLAS to
continue to run effectively at the highest luminosities foreseen from the LHC.
Emphasis is placed on those R&D efforts in which US institutions are playing a
leading role.


title: Rotating Away Proton Decay in Flipped Unification

abstract:
  It is shown that by a simple extension of the fermion sector of flipped SU(5)
models and other flipped models proton decay coming from dimension-6 operators
can be suppressed by fermion mixing angles by an arbitrary amount in a natural
way.


title: Partial Hamiltonian formalism, multi-time dynamics and singular theories

abstract:
  We formulate singular classical theories without involving constraints.
Applying the action principle for the action (27) we develop a partial (in the
sense that not all velocities are transformed to momenta) Hamiltonian formalism
in the initially reduced phase space (with the canonical coordinates
$q_{i},p_{i}$, where the number $n_{p}$ of momenta $p_{i}$, $i=1,\...,n_{p}$
(17) is arbitrary $n_{p}\leq n$, where $n$ is the dimension of the
configuration space), in terms of the partial Hamiltonian $H_{0}$ (18) and
$(n-n_{p})$ additional Hamiltonians $H_{\alpha}$, $\alpha=n_{p}+1,\...,n$ (20).
We obtain $(n-n_{p}+1)$ Hamilton-Jacobi equations (25)-(26). The equations of
motion are first order differential equations (33)-(34) with respect to
$q_{i},p_{i}$ and second order differential equations (35) for $q_{\alpha}$. If
$H_{0}$, $H_{\alpha}$ do not depend on $\dot{q}_{\alpha}$ (42), then the second
order differential equations (35) become algebraic equations (43) with respect
to $\dot{q}_{\alpha}$. We interpret $q_{\alpha}$ as additional times by (45),
and arrive at a multi-time dynamics. The above independence is satisfied in
singular theories and $r_{W}\leq n_{p}$ (58), where $r_{W}$ is the Hessian
rank. If $n_{p}=r_{W}$, then there are no constraints. A classification of the
singular theories is given by analyzing system (62) in terms of
$F_{\alpha\beta}$ (63). If its rank is full, then we can solve the system (62);
if not, some of $\dot{q}_{\alpha}$ remain arbitrary (sign of a gauge theory).
We define new antisymmetric brackets (69) and (80) and present the equations of
motion in the Hamilton-like form, (67)-(68) and (81)-(82) respectively. The
origin of the Dirac constraints in our framework is shown: if we define extra
momenta $p_{\alpha}$ by (86), then we obtain the standard primary constraints
(87), and the new brackets transform to the Dirac bracket. Quantization is
discussed.


title: Hermitian realizations of kappa-Minkowski spacetime

abstract:
  General realizations, star products and plane waves for kappa-Minkowski
spacetime are considered. Systematic construction of general hermitian
realization is presented, with special emphasis on noncommutative plane waves
and hermitian star product. Few examples are elaborated and possible physical
applications are mentioned.


title: Bulk Majorana mass terms and Dirac neutrinos in Randall Sundrum Model

abstract:
  We present a novel scheme where Dirac neutrinos are realized even if lepton
number violating Majorana mass terms are present. The setup is the
Randall-Sundrum framework with bulk right handed neutrinos. Bulk mass terms of
both Majorana and Dirac type are considered. It is shown that massless zero
mode solutions exist when the bulk Dirac mass term is set to zero. In this
limit, it is found that the effective 4D small neutrino mass is primarily of
Dirac nature with the Majorana type contributions being negligible.
Interestingly, this scenario is very similar to the one known with flat extra
dimensions. Neutrino phenomenology is discussed by fitting both charged lepton
masses and neutrino masses simultaneously. A single Higgs localised on the IR
brane is highly constrained as unnaturally large Yukawa couplings are required
to fit charged lepton masses. A simple extension with two Higgs doublets is
presented which facilitates a proper fit for the lepton masses.


title:
Additional spectra of asteroid 1996 FG3, backup target of the ESA
  MarcoPolo-R mission

abstract:
  Near-Earth binary asteroid (175706) 1996 FG3 is the current backup target of
the ESA MarcoPolo-R mission, selected for the study phase of ESA M3 missions.
It is a primitive (C-type) asteroid that shows significant variation in its
visible and near-infrared spectra. Here we present new spectra of 1996 FG3 and
we compare our new data with other published spectra, analysing the variation
in the spectral slope. The asteroid will not be observable again over the next
three years at least. We obtained the spectra using DOLORES and NICS
instruments at the Telescopio Nazionale Galileo (TNG), a 3.6m telescope located
at El Roque de los Muchachos Observatory in La Palma, Spain. To compare with
other published spectra of the asteroid, we computed the spectral slope S', and
studied any plausible correlation of this quantity with the phase angle
(alpha). In the case of visible spectra, we find a variation in spectral slope
of Delta S' = 0.15 +- 0.10 %/10^3 A/degree for 3 < alpha < 18 degrees, in good
agreement with the values found in the literature for the phase reddening
effect. In the case of the near-infrared, we find a variation in the slope of
Delta S' = 0.04 +- 0.08 %/10^3 A/degree for 6 < alpha < 51 degrees. Our
computed variation in S' agrees with the only two values found in the
literature for the phase reddening in the near-infrared. The variation in the
spectral slope of asteroid 1996 FG3 shows a trend with the phase angle at the
time of the observations, both in the visible and the near-infrared. It is
worth noting that, to fully explain this spectral variability we should take
into account other factors, like the position of the secondary component of the
binary asteroid 1999 FG3 with respect to the primary, or the spin axis
orientation at the time of the observations. More data are necessary for an
analysis of this kind.


title:
The evidence of quasi-free positronium state in GiPS-AMOC spectra of
  glycerol

abstract:
  We present the results of processing of Age-Momentum Correlation (AMOC)
spectra that were measured for glycerol by the Gamma-induced positron
spectroscopy (GiPS) facility. Our research has shown that the shape of
experimental s(t) curve cannot be explained without introduction of the
intermediate state of positronium (Ps), called quasi-free Ps. This state yields
the wide Doppler line near zero lifetimes. We discuss the possible properties
of this intermediate Ps state from the viewpoint of developed model. The amount
of annihilation events produced by quasi-free Ps is estimated to be less than
5% of total annihilations. In the proposed model, quasi-free Ps serves as a
precursor for trapped Ps of para- and ortho-states.


title: An exact algorithm for 1-in-3 SAT

abstract:
  1-in-3 SAT is an NP-complete variant of 3-SAT\ where a "clause" is satisfied
iff exactly one of its three literal is satisfied. We present here an exact
algorithm solving \oit\ in time $O^*(1.260^n)$.


title: Generalizing Krawtchouk polynomials using Hadamard matrices

abstract:
  We investigate polynomials, called m-polynomials, whose generator polynomial
has coefficients that can be arranged as a matrix, where q is a positive
integer greater than one. Orthogonality relations are established and
coefficients are obtained for the expansion of a polynomial in terms of
m-polynomials. We conclude this article by an implementation in MATHEMATICA of
m-polynomials and the results obtained for them.


title:
Energy of adsorption at semiconducting surfaces with Fermi level
  differently pinned -- ab initio study

abstract:
  It is shown that adsorption energy at semiconductor surfaces critically
depends on the charge transfer to or from the adsorbed species. For the
processes without the charge transfer, such as molecular adsorption of closed
shell systems, the adsorption energy is determined by the bonding only. In the
case involving charge transfer, such as open shell systems like metal atoms or
the dissociating molecules, the energy attains different value for the Fermi
level differently pinned. The DFT simulation of adsorption of ammonia at
hydrogen covered GaN(0001) confirms these predictions: the molecular adsorption
is independent on the coverage while the dissociative process energy varies by
several electronvolts.


title: Certifying Separability in Symmetric Mixed States, and Superradiance

abstract:
  Separability criteria are typically of the necessary, but not sufficient,
variety, in that satisfying some separability criterion, such as positivity of
eigenvalues under partial transpose, does not strictly imply separability.
Certifying separability amounts to proving the existence of a decomposition of
a target mixed state into some convex combination of separable states;
determining the existence of such a decomposition is "hard." We show that it is
effective to ask, instead, if the target mixed state "fits" some preconstructed
separable form, in that one can generate a sufficient separability criterion
relevant to all target states in some family by ensuring enough degrees of
freedom in the preconstructed separable form. We demonstrate this technique by
inducing a sufficient criterion for "diagonally symmetric" states of N qubits.
A sufficient separability criterion opens the door to study precisely how
entanglement is (not) formed; we use ours to prove that, counterintuitively,
entanglement is not generated in idealized Dicke model superradiance despite
its exemplification of many-body effects. We introduce a quantification of the
extent to which a given preconstructed parametrization comprises the set of all
separable states; for "diagonally symmetric" states our preconstruction is
shown to be fully complete. This implies that our criterion is necessary in
addition to sufficient, among other ramifications which we explore.


title: Supports of irreducible characters of p-groups

abstract:
  If chi is an irreducible character of a finite group G then the support of
chi is the subset of G on which chi does not vanish. In this note, we study the
supports of characters of certain classes of p-groups (a p-group is a finite
group of prime power order). We show that if chi is an irreducible character of
a metabelian p-group P, then the support of chi contains at most |P|/chi(1)^2
conjugacy classes, and we give a bound on the orders of the elements in the
support. We give more precise results for p-groups of nilpotence class at most
3 and groups of order dividing p^9.


title: Moving to Extremal Graph Parameters

abstract:
  Which graphs, in the class of all graphs with given numbers n and m of edges
and vertices respectively, minimizes or maximizes the value of some graph
parameter? In this paper we develop a technique which provides answers for
several different parameters: the numbers of edges in the line graph, acyclic
orientations, cliques, and forests. (We minimize the first two and maximize the
third and fourth.)
  Our technique involves two moves on the class of graphs. A compression move
converts any graph to a form we call fully compressed: the fully compressed
graphs are split graphs in which the neighbourhoods of points in the
independent set are nested. A second consolidation move takes each fully
compressed graph to one particular graph which we call H(n,m). We show
monotonicity of the parameters listed for these moves in many cases, which
enables us to obtain our results fairly simply.
  The paper concludes with some open problems and future directions.


title: Symmetry energy in nuclear density functional theory

abstract:
  The nuclear symmetry energy represents a response to the neutron-proton
asymmetry. In this survey we discuss various aspects of symmetry energy in the
framework of nuclear density functional theory, considering both
non-relativistic and relativistic self-consistent mean-field realizations
side-by-side. Key observables pertaining to bulk nucleonic matter and finite
nuclei are reviewed. Constraints on the symmetry energy and correlations
between observables and symmetry-energy parameters, using statistical
covariance analysis, are investigated. Perspectives for future work are
outlined in the context of ongoing experimental efforts.


title:
Equivariant Lefschetz and Fuller indices via topological intersection
  theory

abstract:
  For a compact Lie group G, we use G-equivariant Poincar\'e duality for
ordinary RO(G)-graded homology to define an equivariant intersection product,
the dual of the equivariant cup product. Using this, we give a homological
construction of the equivariant Lefschetz number and a simple proof of the
equivariant Lefschetz fixed point theorem. With similar techniques, an
equivariant Fuller index with values in the rationalized Burnside ring is
constructed.


title:
Compact and weakly compact composition operators from the Bloch space
  into M\"obius invariant spaces

abstract:
  We obtain exhaustive results and treat in a unified way the question of
boundedness, compactness, and weak compactness of composition operators from
the Bloch space into any space from a large family of conformally invariant
spaces that includes the classical spaces like $BMOA$, $Q_\alpha$, and analytic
Besov spaces $B^p$. In particular, by combining techniques from both complex
and functional analysis, we prove that in this setting weak compactness is
equivalent to compactness. For the operators into the corresponding "small"
spaces we also characterize the boundedness and show that it is equivalent to
compactness.


title: On dynamics of composite entire functions and singularities

abstract:
  We consider the dynamical properties of transcendental entire functions and
their compositions. We give several conditions under which Fatou set of a
transcendental entire function $f$ coincide with that of $f\circ g,$ where $g$
is another transcendental entire function. We also prove some result giving
relationship between singular values of transcendental entire functions and
their compositions.


title: Astrometric mass ratios for three spectroscopic binaries

abstract:
  The orbits of five single-lined spectroscopic binaries have recently been
determined. We now use astrometric measurements that were collected with the
Hipparcos satellite to constrain the systems' mass ratios and secondary masses.
The barycentric astrometric orbits of three binary systems, HD 140667, HD
158222, and HD 217924, are fully determined and precise estimates of their mass
ratios are obtained. Follow-up of these systems with infrared spectroscopy
could yield model-independent dynamical masses for all components.


title: Charged Lepton Flavor Violation: An Experimenter's Guide

abstract:
  Charged lepton flavor violation (CLFV) is a clear signal of new physics; it
directly addresses the physics of flavor and of generations. The search for
CLFV has continued from the early 1940's, when the muon was identified as a
separate particle, until today. Certainly in the LHC era the motivations for
continued searches are clear and have been covered in many reviews. This review
is focused on the experimental history with a view toward how these searches
might progress. We examine of the status of searches for charged lepton flavor
violation in the muon, tau, and other channels, and then examine the prospects
for new efforts over the next decade. Finally, we examine what paths might be
taken after the conclusion of upcoming experiments and what facilities might be
required.


title: Overdetermined systems of sparse polynomial equations

abstract:
  We show that, for a system of univariate polynomials given in sparse
encoding, we can compute a single polynomial defining the same zero set, in
time quasi-linear in the logarithm of the degree. In particular, it is possible
to determine whether such a system of polynomials does have a zero in time
quasi-linear in the logarithm of the degree. The underlying algorithm relies on
a result of Bombieri and Zannier on multiplicatively dependent points in
subvarieties of an algebraic torus.
  We also present the following conditional partial extension to the higher
dimensional setting. Assume that the effective Zilber conjecture holds. Then,
for a system of multivariate polynomials given in sparse encoding, we can
compute a finite collection of complete intersections outside hypersurfaces
that defines the same zero set, in time quasi-linear in the logarithm of the
degree.


title: Search for neutrino-antineutrino oscillations with a reactor experiment

abstract:
  The disappearance of reactor antineutrinos in the Double Chooz experiment is
used to investigate the possibility of neutrino-antineutrino oscillations
arising due to the breakdown of Lorentz invariance. We find no evidence for
this phenomenon and set the first limits on 15 coefficients describing
neutrino-antineutrino mixing within the framework of the Standard-Model
Extension.


title: Natural MSSM after the LHC 8 TeV run

abstract:
  We investigate the impact of direct LHC SUSY searches on the parameter space
of three natural scenarios in the MSSM. In the first case the spectrum consists
of light stops, sbottoms, and Higgsino-like neutralinos, while the other
particles are assumed to be out of the experimental reach. In the second case
we consider an additional light gluino. Finally we study a more complex
spectrum comprising also light sleptons, a wino-like chargino, and a bino-like
neutralino. We simulate in detail three LHC searches: stop production at ATLAS
with 20.7/fb, CMS 11.7/fb inclusive search for squarks and gluinos with the
variable \alpha_T, and CMS 9.2/fb electroweak production with 3 leptons in the
final state. For each point in our scans we calculate the exclusion likelihood
due to the individual searches and to their statistical combination. We
calculate the fine-tuning measure of the points allowed by the LHC and the
implications for the Higgs mass and other phenomenological observables: Higgs
signal rates, the relic density, BR(Bs --> \mu^+\mu^-), BR(B --> Xs \gamma),
and the spin-independent neutralino-proton scattering cross section. We find
that points with acceptable levels of fine-tuning are for the most part already
excluded by the LHC and including the other constraints further reduces the
overall naturalness of our scenarios.


title:
Low-amplitude rotational modulation rather than pulsations in the CoRoT
  B-type supergiant HD 46769

abstract:
  {We aim to detect and interpret photometric and spectroscopic variability of
the bright CoRoT B-type supergiant target HD\,46769 ($V=5.79$). We also attempt
to detect a magnetic field in the target.} {We analyse a 23-day oversampled
CoRoT light curve after detrending, as well as spectroscopic follow-up data, by
using standard Fourier analysis and Phase Dispersion Minimization methods. We
determine the fundamental parameters of the star, as well as its abundances
from the most prominent spectral lines. We perform a Monte Carlo analysis of
spectropolarimetric data to obtain an upper limit of the polar magnetic field,
assumping a dipole field.} {In the CoRoT data, we detect a dominant period of
4.84\,d with an amplitude of 87\,ppm, and some of its (sub-)multiples. Given
the shape of the phase-folded light curve and the absence of binary motion, we
interpret the dominant variability in terms of rotational modulation, with a
rotation period of 9.69\,d. Subtraction of the rotational modulation signal
does not reveal any sign of pulsations. Our results are consistent with the
absence of variability in the Hipparcos light curve. The spectroscopy leads to
a projected rotational velocity of 72$\pm 2$\,km\,s$^{-1}$ and does not reveal
periodic variability nor the need to invoke macroturbulent line broadening. No
signature of a magnetic field is detected in our data. A field stronger than
$\sim 500$\,G at the poles can be excluded, unless the possible non-detected
field were more complex than dipolar.} {The absence of pulsations and of
macroturbulence of this evolved B-type supergiant is placed into context of
instability computations and of observed variability of evolved B-type stars.}


title: Twisted quasiperiodic textures of biaxial nematics

abstract:
  Textures (i.e., smooth space non-uniform distributions of the order
parameter) in biaxial nematics turned out to be much more difficult and
interesting than expected. Scanning the literature we find only a very few
publications on this topic. Thus, the immediate motivation of the present paper
is to develop a systematic procedure to study, classify and visualize possible
textures in biaxial nematics. Based on the elastic energy of a biaxial nematic
(written in the most simple form that involves the least number of
phenomenological parameters) we derive and solve numerically the Lagrange
equations of the first kind. It allows one to visualize the solutions and
offers a deep insight into their geometrical and topological features.
Performing Fourier analysis we find some particular textures possessing two or
more characteristic space periods (we term such solutions quasiperiodic ones
because the periods are not necessarily commensurate). The problem is not only
of intellectual interest but also of relevance to optical characteristics of
the liquid-crystalline textures.


title: Umbral Moonshine and the Niemeier Lattices

abstract:
  In this paper we relate umbral moonshine to the Niemeier lattices: the 23
even unimodular positive-definite lattices of rank 24 with non-trivial root
systems. To each Niemeier lattice we attach a finite group by considering a
naturally defined quotient of the lattice automorphism group, and for each
conjugacy class of each of these groups we identify a vector-valued mock
modular form whose components coincide with mock theta functions of Ramanujan
in many cases. This leads to the umbral moonshine conjecture, stating that an
infinite-dimensional module is assigned to each of the Niemeier lattices in
such a way that the associated graded trace functions are mock modular forms of
a distinguished nature. These constructions and conjectures extend those of our
earlier paper, and in particular include the Mathieu moonshine observed by
Eguchi-Ooguri-Tachikawa as a special case. Our analysis also highlights a
correspondence between genus zero groups and Niemeier lattices. As a part of
this relation we recognise the Coxeter numbers of Niemeier root systems with a
type A component as exactly those levels for which the corresponding classical
modular curve has genus zero.


title:
Quantum Monte Carlo study of the three-dimensional spin-polarized
  homogeneous electron gas

abstract:
  We have studied the spin-polarized three-dimensional homogeneous electron gas
using the diffusion quantum Monte Carlo method, with trial wave functions
including backflow and three-body correlations in the Jastrow factor, and we
have used twist averaging to reduce finite-size effects. Calculations of the
pair correlation function, including the on-top pair density, as well as the
structure factor and the total energy, are reported for systems of 118
electrons in the density range $r_\text{s}=0.5$--20 a.u., and for spin
polarizations of 0, 0.34, 0.66, and 1. We consider the spin resolution of the
pair correlation function and structure factor, and the energy of spin
polarization. We show that a control variate method can reduce the variance
when twist-averaging, and we have achieved higher accuracy and lower noise than
earlier quantum Monte Carlo studies.


title: Multicharge Superstrings

abstract:
  There are an infinite number of type IIB superstrings in ten dimensions,
called (p,q) strings, that are labeled by two distinct string charges. They can
form string junctions and string networks. These are the key to understanding
the Coulomb branch BPS spectrum of N=4 super Yang--Mills theories in four
dimensions. Nongravitational theories that are analogous to type IIB
superstring theory in some respects are the ADE (2,0) six-dimensional theories
on the Coulomb branch. Each of them contains a finite number of half-BPS
superstrings, which can be labeled by the root vectors of the Lie algebra. When
the rank is greater than one, these strings can also form string junctions and
string networks. The relationship between N=4 super Yang--Mills theories in
four dimensions and the (2,0) theories in six dimensions can be explored by
utilizing the duality between type IIB superstring theory compactified on a
circle and M-theory compactified on a torus.


title: On Araujo's Theorem for flows

abstract:
  Araujo proved in his thesis \cite{A} that a $C^1$ generic surface
diffeomorphism has either infinitely many sinks (i.e. attracting periodic
orbits) or finitely many hyperbolic attractors with full Lebesgue measure
basin. The goal of this paper is to extend this result to $C^1$ vector fields
on compact connected boundaryless manifolds $M$ of dimension 3
(three-dimensional flows for short). More precisely, we shall prove that a
$C^1$ generic three-dimensional flow without singularities has either
infinitely many sinks or finitely many hyperbolic attractors with full Lebesgue
measure basin.


title: Shape Calculus for Shape Energies in Image Processing

abstract:
  Many image processing problems are naturally expressed as energy minimization
or shape optimization problems, in which the free variable is a shape, such as
a curve in 2d or a surface in 3d. Examples are image segmentation, multiview
stereo reconstruction, geometric interpolation from data point clouds. To
obtain the solution of such a problem, one usually resorts to an iterative
approach, a gradient descent algorithm, which updates a candidate shape
gradually deforming it into the optimal shape. Computing the gradient descent
updates requires the knowledge of the first variation of the shape energy, or
rather the first shape derivative. In addition to the first shape derivative,
one can also utilize the second shape derivative and develop a Newton-type
method with faster convergence. Unfortunately, the knowledge of shape
derivatives for shape energies in image processing is patchy. The second shape
derivatives are known for only two of the energies in the image processing
literature and many results for the first shape derivative are limiting, in the
sense that they are either for curves on planes, or developed for a specific
representation of the shape or for a very specific functional form in the shape
energy. In this work, these limitations are overcome and the first and second
shape derivatives are computed for large classes of shape energies that are
representative of the energies found in image processing. Many of the formulas
we obtain are new and some generalize previous existing results. These results
are valid for general surfaces in any number of dimensions. This work is
intended to serve as a cookbook for researchers who deal with shape energies
for various applications in image processing and need to develop algorithms to
compute the shapes minimizing these energies.


title:
Experimental Limits on Primordial Black Hole Dark Matter from the First
  Two Years of Kepler Data

abstract:
  We present the analysis on our new limits of the dark matter (DM) halo
consisting of primordial black holes (PBHs) or massive compact halo objects
(MACHOs). We present a search of the first two years of publicly available
Kepler mission data for potential signatures of gravitational microlensing
caused by these objects, as well as an extensive analysis of the astrophysical
sources of background error. These include variable stars, flare events, and
comets or asteroids which are moving through the Kepler field. We discuss the
potential of detecting comets using the Kepler lightcurves, presenting
measurements of two known comets and one unidentified object, most likely an
asteroid or comet. After removing the background events with statistical cuts,
we find no microlensing candidates. We therefore present our Monte Carlo
efficiency calculation in order to constrain the PBH DM with masses in the
range of 2 x 10^-9 solar masses to 10^-7 solar masses. We find that PBHs in
this mass range cannot make up the entirety of the DM, thus closing a full
order of magnitude in the allowed mass range for PBH DM.


title: Schr\"odinger equations with asymptotically periodic terms

abstract:
  We study the existence of nontrivial solutions for a class of asymptotically
periodic semilinear Schr\"odinger equations in $\mathbb{R}^N$. By combining
variational methods and the concentration-compactness principle we obtain a
nontrivial solution for asymptotically periodic problem and a ground state
solution for the periodic problem. In the proofs we apply the Mountain Pass
Theorem and its local version.


title:
An Adaptive GMM Approach to Background Subtraction for Application in
  Real Time Surveillance

abstract:
  Efficient security management has become an important parameter in todays
world. As the problem is growing, there is an urgent need for the introduction
of advanced technology and equipment to improve the state-of art of
surveillance. In this paper we propose a model for real time background
subtraction using AGMM. The proposed model is robust and adaptable to dynamic
background, fast illumination changes, repetitive motion. Also we have
incorporated a method for detecting shadows using the Horpresert color model.
The proposed model can be employed for monitoring areas where movement or entry
is highly restricted. So on detection of any unexpected events in the scene an
alarm can be triggered and hence we can achieve real time surveillance even in
the absence of constant human monitoring.


title: When universal edge-colored directed graph $C^*$-algebras are exact

abstract:
  We consider when the universal $C^*$-algebras associated to edge-colored
directed graphs are exact. Specifically, for countable edge-colored directed
graphs we show that the universal $C^*$-algebra is exact if and only if the
$C^*$-algebra is isomorphic to a graph $C^*$-algebra which occurs precisely
when the universal and reduced $C^*$-algebras of the edge-colored directed
graph are isomorphic.


title:
Graph theoretic invariants for operator algebras associated to
  topological dynamics

abstract:
  We expand on some invariants used for classifying nonselfadjoint operator
algebras. Specifically to nonselfadjoint operator algebras which have a
conditional expectation onto a commutative diagonal we construct an
edge-colored directed graph which can be used as an operator algebra invariant.


title:
Regularly Varying Measures on Metric Spaces: Hidden Regular Variation
  and Hidden Jumps

abstract:
  We develop a framework for regularly varying measures on complete separable
metric spaces $\mathbb{S}$ with a closed cone $\mathbb{C}$ removed, extending
material in Hult & Lindskog (2006), Das, Mitra & Resnick (2013). Our framework
provides a flexible way to consider hidden regular variation and allows
simultaneous regular variation properties to exist at different scales and
provides potential for more accurate estimation of probabilities of risk
regions. We apply our framework to iid random variables in
$\mathbb{R}_+^\infty$ with marginal distributions having regularly varying
tails and to c\`adl\`ag L\'evy processes whose L\'evy measures have regularly
varying tails. In both cases, an infinite number of regular variation
properties coexist distinguished by different scaling functions and state
spaces.


title:
Fluctuation-induced First Order Quantum Phase Transition of U(1) Quantum
  Spin Liquid in Pyrochlore Quantum Antiferromagnet

abstract:
  We show using quantum free energy calculation that the quantum phase
transition between U(1) quantum spin liquid (QSL) and antiferromagnet (AFM)
phases in pyrochlore quantum antiferromagnet (QAFM) is a first order rather
than second order. This change in order from second to first order is induced
by gauge fluctuations, which are explicitly taken into account at gauge theory
level in our effective low energy theory. We therefore have discovered a
fluctuation-induced first order quantum phase transition in pyrochlore QAFM. We
explicitly derive the quantum free energy description of this QSL to AFM phase
transition and show that it is a weakly first order phase transition. We also
briefly discuss the experimental relevance of this result.


title: Testing Lorentz Symmetry with the Double Chooz Experiment

abstract:
  The Double Chooz reactor-based oscillation experiment searches for an
electron antineutrino disappearance signal to investigate the neutrino mass
matrix mixing angle theta 13. Double Chooz's reported evidence for this
disappearance is generally interpreted as mass-driven mixing through this
parameter. However, the electron antineutrino candidates collected by the
experiment can also be used to search for a signature of the violation of
Lorentz invariance.
  We study the sidereal time dependence of the antineutrino signal rate and
probe Lorentz violation within the Standard-Model Extension (SME) framework. We
find that the data prefer the sidereal time independent solution, and a number
of limits are applied to the relevant SME coefficients, including the first
constraints on those associated with Lorentz violation in the e-tau mixing
sector.


title: Semiparametric Models with Single-Index Nuisance Parameters

abstract:
  In many semiparametric models, the parameter of interest is identified
through conditional expectations, where the conditioning variable involves a
single-index that is estimated in the first step. Among the examples are sample
selection models and propensity score matching estimators. When the first-step
estimator follows cube-root asymptotics, no method of analyzing the asymptotic
variance of the second step estimator exists in the literature. This paper
provides nontrivial sufficient conditions under which the asymptotic variance
is not affected by the first step single index estimator regardless of whether
it is root-n or cube-root consistent. The finding opens a way to simple
inference procedures in these models. Results from Monte Carlo simulations show
that the procedures perform well in finite samples.


title:
Computation of the w-primality and asymptotic w-primality with
  applications to numerical semigroups

abstract:
  We give an algorithm to compute the $\omega$-primality of finitely generated
atomic monoids. Asymptotic $\w$-primality is also studied and a formula to
obtain it in finitely generated quasi-Archimedean monoids is proven. The
formulation is applied to numerical semigroups, obtaining an expression of this
invariant in terms of its system of generators.


title: An inequality on global alliances for trees

abstract:
  In this paper, we prove an inequality on the cardinalities of the minimum
size global defensive alliance and the minimum size global offensive alliance.
A global defensive alliance is a dominating set such that when any point inside
a selected group $S$ is chosen, at least half of the points in its neighborhood
are also in the set $S$, including the selected point. A global offensive
alliance is a dominating set such that if any point outside $S$ is selected, at
least half of the points in its neighborhood, including the selected point, are
in set $S$. Our result answers an open question in [HA].


title:
Earthquake Counting Method for Spatially Localized Probabilities:
  Challenges in Real-Time Information Delivery

abstract:
  We develop and implement a new type of global earthquake forecast. Our
forecast is a perturbation on a smoothed seismicity (Relative Intensity)
spatial forecast combined with a temporal time-averaged (Poisson) forecast. A
variety of statistical and fault-system models have been discussed for use in
computing forecast probabilities. Our paper takes a new approach. The idea is
based on the observation that GR statistics characterize seismicity for all
space and time. Small magnitude event counts (quake counts) are used as markers
for the approach of large events. More specifically, if the GR b-value = 1,
then for every 1000 M>3 earthquakes, one expects 1 M>6 earthquake. So if ~1000
M>3 events have occurred in a spatial region since the last M>6 earthquake,
another M>6 earthquake should be expected soon. In physics, event count models
have been called natural time models, since counts of small events represent a
physical or natural time scale characterizing the system dynamics. In a
previous paper, we used conditional Weibull statistics to convert event counts
into a temporal probability for a given fixed region. In the present paper, we
dispense with a fixed region, and develop a method to compute these Natural
Time Weibull (NTW) forecasts on a global scale, using an internally consistent
method, in regions of arbitrary shape and size. Among the results we find that
the Japan region is at serious risk for a major (M>8) earthquake over the next
year or two, a result that also follows from considering completeness of the
Gutenberg-Richter relation.


title: Synthetic Graphene Grown by Chemical Vapor Deposition on Copper Foils

abstract:
  The discovery of graphene, a single layer of covalently bonded carbon atoms,
has attracted intense interests. Initial studies using mechanically exfoliated
graphene unveiled its remarkable electronic, mechanical and thermal properties.
There has been a growing need and rapid development in large-area deposition of
graphene film and its applications. Chemical vapour deposition on copper has
emerged as one of the most promising methods in obtaining large-scale graphene
films with quality comparable to exfoliated graphene. In this chapter, we
review the synthesis and characterizations of graphene grown on copper foil
substrates by atmospheric pressure chemical vapour deposition. We also discuss
potential applications of such large scale synthetic graphene.


title:
Tunneling into the localized phase near Anderson transitions with
  Coulomb interaction

abstract:
  We study the tunneling density of states (TDOS) of a disordered electronic
system with Coulomb interaction on the insulating side of the Anderson
localization transition. The average TDOS shows a critical behavior at high
energies, with a crossover to a soft Coulomb gap $\Delta$ at low energies. We
demonstrate that the single-particle excitations experience a localization
transition (which belongs to the noninteracting universality class) at an
energy $E=\pm E_c$. The mobility edge $E_c$ scales with the distance
$\mu_c-\mu$ from the interacting critical point according to $E_c\propto
(\mu_c-\mu)^{\nu z}$, where $\nu$ and $z$ are the localization-length and the
dynamical critical exponents. Local TDOS shows strong fluctuations and
long-range correlations which reflect the multifractality associated with
interacting and noninteracting fixed points as well the localization of
low-energy excitations.


title: Poisson AKSZ theories and their quantizations

abstract:
  We generalize the AKSZ construction of topological field theories to allow
the target manifolds to have possibly-degenerate (homotopy) Poisson structures.
Classical AKSZ theories, which exist for all oriented spacetimes, are described
in terms of dioperads. The quantization problem is posed in terms of extending
from dioperads to properads. We conclude by relating the quantization problem
for AKSZ theories on R^d to the formality of the E_d operad, and conjecture a
properadic description of the space of E_d formality quasiisomorphisms.


title:
Measuring Directionality in Double-Beta Decay and Neutrino Interactions
  with Kiloton-Scale Scintillation Detectors

abstract:
  Large liquid-scintillator-based detectors have proven to be exceptionally
effective for low energy neutrino measurements due to their good energy
resolution and scalability to large volumes. The addition of directional
information using Cherenkov light and fast timing would enhance the scientific
reach of these detectors, especially for searches for neutrino-less double-beta
decay. In this paper, we develop a technique for extracting particle direction
using the difference in arrival times for Cherenkov and scintillation light,
and evaluate several detector advances in timing, photodetector spectral
response, and scintillator emission spectra that could be used to make
direction reconstruction a reality in a kiloton-scale detector.


title: Log ramification via curves in rank 1

abstract:
  We prove that in rank 1, the Abbes-Saito log conductor is determined by its
restriction to curves. This result is essentially established by analyzing
Artin-Schreier-Witt extensions. Consequently, we confirm an expectation of H.
Esnault and M. Kerz. We also conjecture that this result holds in arbitrary
finite rank. As an application, we translate recent results in higher class
field theory of M. Kerz and S. Saito to the log-ramification context.


title:
The equation of state of neutron matter, symmetry energy, and neutron
  star structure

abstract:
  We review the calculation of the equation of state of pure neutron matter
using quantum Monte Carlo (QMC) methods. QMC algorithms permit the study of
many-body nuclear systems using realistic two- and three-body forces in a
nonperturbative framework. We present the results for the equation of state of
neutron matter, and focus on the role of three-neutron forces at supranuclear
density. We discuss the correlation between the symmetry energy, the neutron
star radius and the symmetry energy. We also combine QMC and theoretical models
of the three-nucleon interactions, and recent neutron star observations to
constrain the value of the symmetry energy and its density dependence.


title:
Nonlinear Schr\"{o}dinger equation for the twisted Laplacian in the
  critical case

abstract:
  We prove well-posedness of solution to the nonlinear Schr\"{o}dinger equation
associated to the twisted Laplacian on $\C^n$ for a general class of
nonlinearities including power type with subcritical case $0\leq
\alpha<\frac{2}{n-1}$, see Ratnakumar, Sohani (J. Funct. Anal. 2013). In this
paper, we consider critical case $\alpha=\frac{2}{n-1}$ with $n\geq 2$. Our
approach is based on truncation of the given nonlinearity $G$, which is used by
Cazenave Weissler (1989). We obtain solution for the truncated problem. We
obtain solution to the original problem by passing to the limit.


title:
Some $B$-Difference Sequence Spaces Derived by Using Generalized Means
  and Compact Operators

abstract:
  This paper presents new sequence spaces $X(r, s, t, p ; B)$ for $X \in
\{l_\infty(p), c(p), c_0(p), l(p)\}$ defined by using generalized means and
difference operator. It is shown that these spaces are complete paranormed
spaces and the spaces $X(r, s, t, p ; B)$ for $X \in \{c(p), c_0(p), l(p)\}$
have Schauder basis. Furthermore, the $\alpha$-, $\beta$-, $\gamma$- duals of
these sequence spaces are computed and also obtained necessary and sufficient
conditions for some matrix transformations from $X(r, s, t, p ;B)$ to $X$.
Finally, some classes of compact operators on the space $l_p(r, s, t ;B)$ are
characterized by using the Hausdorff measure of noncompactness.


title: On what does not expand in an expanding universe: a very simple model

abstract:
  As the separation between galaxies increases owing to the expansion of the
universe, galaxies themselves and smaller bound structures do not grow. An
accurate description of the dynamics of cosmic structures requires the full
apparatus of general relativity. In order to gain a fairly satisfactory
understanding of what does not expand in an expanding universe, however, it
suffices to take the harmonic oscillator as prototype of a bound system. More
precisely, we show that a study of the quantum dynamics of a nonrelativistic
harmonic oscillator in an expanding universe makes it clear that most bound
systems do not take part in the overall cosmic expansion. The analysis is
elementary and indicates that whether a bound structure partakes in the
expansion partially or not at all is essentially determined by a characteristic
time scale associated with it.


title: Dimensional-Crossover-Driven Mott Insulators in SrVO3 Ultrathin Films

abstract:
  High-quality epitaxial SrVO3 (SVO) thin films of various thicknesses were
grown on (001)-oriented LSAT substrates by pulsed electron-beam deposition
technique. Thick SVO films (~25 nm) exhibited metallic behavior with the
electrical resistivity following the T2 law corresponding to a Fermi liquid
system. We observed a temperature driven metal-insulator transition (MIT) in
SVO ultrathin films with thicknesses below 6.5 nm, the transition temperature
TMIT was found to be at 50 K for the 6.5 nm film, 120 K for the 5.7 nm film and
205 K for the 3 nm film. The emergence of the observed MIT can be attributed to
the dimensional crossover from a three-dimensional metal to a two-dimensional
Mott insulator, as the resulting reduction in the effective bandwidth W opens a
band gap at the Fermi level. The magneto-transport study of the SVO ultrathin
films also confirmed the observed MIT is due to the electron-electron
interactions other than localization.


title:
Metal Abundances, Radial Velocities and other Physical Characteristics
  for the RR Lyrae Stars in the Kepler Field

abstract:
  Spectroscopic iron-to-hydrogen ratios, radial velocities, atmospheric
parameters, and new photometric analyses are presented for 41 RR Lyrae stars
(and one probable high-amplitude delta Scuti star) located in the field-of-view
of the Kepler space telescope. Thirty-seven of the RR Lyrae stars are
fundamental-mode pulsators (i.e., RRab stars) of which 16 exhibit the Blazhko
effect. Four of the stars are multiperiodic RRc pulsators oscillating primarily
in the first-overtone mode. Spectroscopic [Fe/H] values for the 34 stars for
which we were able to derive estimates range from -2.54 +/- 0.13 (NR Lyr) to
-0.05 +/- 0.13 dex (V784 Cyg), and for the 19 Kepler-field non-Blazhko stars
studied by Nemec et al.(2011) the abundances agree will with their photometric
[Fe/H] values. Four non-Blazhko RR Lyrae stars that they identified as
metal-rich (KIC 6100702, V2470 Cyg, V782 Cyg and V784 Cyg) are confirmed as
such, and four additional stars (V839 Cyg, KIC 5520878, KIC 8832417, KIC
3868420) are also shown here to be metal-rich. Five of the non-Blazhko RRab
stars are found to be more metal-rich than [Fe/H] -0.9 dex while all of the 16
Blazhko stars are more metal-poor than this value. New period-phi31s-[Fe/H]
relationships are derived based on ~970 days of quasi-continuous high-precison
Q0-Q11 long- and short-cadence Kepler photometry. With the exception of some
Blazhko stars, the spectroscopic and photometric [Fe/H] values are in good
agreement. Several stars with unique photometric characteristics are
identified, including a Blazhko variable with the smallest known amplitude and
frequency modulations (V838 Cyg).


title:
Gravity-induced phase-shift of light: outline of an interferometric test
  of the Equivalence Principle

abstract:
  I analyze the change of the interference pattern in an optical interferometer
when it passes from rest to free fall. It is shown that the "disconnection" of
the gravitational field causes a jump in the phase difference that could be
measured with the current sensitivity of these instruments. For this reason, I
propose to the optical interferometry community the possibility of a test of
the Equivalence Principle based on the aforementioned effect.


title: Some remarks on resonances in even-dimensional Euclidean scattering

abstract:
  The purpose of this paper is to prove some results about quantum mechanical
black box scattering in even dimensions $d \geq 2$. We study the scattering
matrix and prove some identities which hold for its meromorphic continuation
onto $\Lambda$, the Riemann surface of the logarithm function. We relate the
multiplicities of the poles of the continued scattering matrix to the
multiplicities of the poles of the resolvent. Moreover, we show that the poles
of the scattering matrix on the $m$th sheet of $\Lambda$ are related to the
zeros of a scalar function defined on the physical sheet. This paper contains a
number of results about "pure imaginary" resonances. As an example, in contrast
with the odd-dimensional case, we show that in even dimensions there are no
"purely imaginary" resonances on any sheet of $\Lambda$ for Schr\"odinger
operators with potentials $0 \leq V \in L_0^\infty (\R^d)$.


title:
Gravitational Collapse With Dark Energy And Dark Matter In
  Ho\v{r}ava-Lifshitz Gravity

abstract:
  In this work, the collapsing process of a spherically symmetric star, made of
dust cloud, is studied in Ho\v{r}ava Lifshitz gravity in the background of
Chaplygin gas dark energy. Two different classes of Chaplygin gas, namely, New
variable modified Chaplygin gas and generalized cosmic Chaplygin gas are
considered for the collapse study. Graphs are drawn to characterize the nature
and to determine the possible outcome of gravitational collapse. A comparative
study is done between the collapsing process in the two different dark energy
models. It is found that for open and closed universe, collapse proceeds with
an increase in black hole mass, the only constraint being that, relatively
smaller values of $\Lambda$ has to be considered in comparison to $\lambda$.
But in case of flat universe, possibility of the star undergoing a collapse in
highly unlikely. Moreover it is seen that the most favourable environment for
collapse is achieved when a combination of dark energy and dark matter is
considered, both in the presence and absence of interaction. Finally, it is to
be seen that, contrary to our expectations, the presence of dark energy does
not really hinder the collapsing process in case of Ho\v{r}ava-Lifshitz
gravity.


title:
A Fourier-based Approach for Iterative 3D Reconstruction from Cryo-EM
  Images

abstract:
  A major challenge in single particle reconstruction methods using
cryo-electron microscopy is to attain a resolution sufficient to interpret fine
details in three-dimensional (3D) macromolecular structures. Obtaining high
resolution 3D reconstructions is difficult due to unknown orientations and
positions of the imaged particles, possible incomplete coverage of the viewing
directions, high level of noise in the projection images, and limiting effects
of the contrast transfer function of the electron microscope. In this paper, we
focus on the 3D reconstruction problem from projection images assuming an
existing estimate for their orientations and positions. We propose a fast and
accurate Fourier-based Iterative Reconstruction Method (FIRM) that exploits the
Toeplitz structure of the operator ${\bf A}^{*}{\bf A}$, where $\bf A$ is the
forward projector and ${\bf A}^{*}$ is the back projector. The operator ${\bf
A}^{*}{\bf A}$ is equivalent to a convolution with a kernel. The kernel is
pre-computed using the non-uniform Fast Fourier Transform and is efficiently
applied in each iteration step. The iterations by FIRM are therefore
considerably faster than those of traditional iterative algebraic approaches,
while maintaining the same accuracy even when the viewing directions are
unevenly distributed. The time complexity of FIRM is comparable to the direct
Fourier inversion method. Moreover, FIRM combines images from different defocus
groups simultaneously and can handle a wide range of regularization terms. We
provide experimental results on simulated data that demonstrate the speed and
accuracy of FIRM in comparison with current methods.


title:
Entropic repulsion of Gaussian free field on high-dimensional Sierpinski
  carpet graphs

abstract:
  Consider the free field on a fractal graph based on a high-dimensional
Sierpinski carpet (e.g. the Menger sponge), that is, a centered Gaussian field
whose covariance is the Green's function for simple random walk on the graph.
Moreover assume that a "hard wall" is placed at height zero so that the field
stays positive everywhere. We prove the leading-order asymptotics for the local
sample mean of the free field above the hard wall on any transient Sierpinski
carpet graph, thereby extending a result of Bolthausen, Deuschel, and Zeitouni
for the free field on $\mathbb{Z}^d$, $d \geq 3$, to the fractal setting. Our
proof utilizes the theory of transient regular Dirichlet forms, in conjunction
with the relative entropy, coarse graining, and conditioning arguments
introduced in the previous literature.

categories: math.PR cond-mat.stat-mech math-ph math.MP


title: Remarks on Adjoint QCD with k Flavors, k>= 2

abstract:
  I summarize what we know of adjoint QCD. Some observations (albeit very
simple) are new.


title: Cooperative Energy Harvesting Networks with Spatially Random Users

abstract:
  This paper considers a cooperative network with multiple source-destination
pairs and one energy harvesting relay. The outage probability experienced by
users in this network is characterized by taking the spatial randomness of user
locations into consideration. In addition, the cooperation among users is
modeled as a canonical coalitional game and the grand coalition is shown to be
stable in the addressed scenario. Simulation results are provided to
demonstrate the accuracy of the developed analytical results.


title: Higher preprojective algebras and stably Calabi-Yau properties

abstract:
  In this paper, we give sufficient properties for a finite dimensional graded
algebra to be a higher preprojective algebra. These properties are of
homological nature, they use Gorensteiness and bimodule isomorphisms in the
stable category of Cohen-Macaulay modules. We prove that these properties are
also necessary for $3$-preprojective algebras using \cite{Kel11} and for
preprojective algebras of higher representation finite algebras using
\cite{Dugas}.


title: New and Improved Spanning Ratios for Yao Graphs

abstract:
  For a set of points in the plane and a fixed integer $k > 0$, the Yao graph
$Y_k$ partitions the space around each point into $k$ equiangular cones of
angle $\theta=2\pi/k$, and connects each point to a nearest neighbor in each
cone. It is known for all Yao graphs, with the sole exception of $Y_5$, whether
or not they are geometric spanners. In this paper we close this gap by showing
that for odd $k \geq 5$, the spanning ratio of $Y_k$ is at most
$1/(1-2\sin(3\theta/8))$, which gives the first constant upper bound for $Y_5$,
and is an improvement over the previous bound of $1/(1-2\sin(\theta/2))$ for
odd $k \geq 7$. We further reduce the upper bound on the spanning ratio for
$Y_5$ from $10.9$ to $2+\sqrt{3} \approx 3.74$, which falls slightly below the
lower bound of $3.79$ established for the spanning ratio of $\Theta_5$
($\Theta$-graphs differ from Yao graphs only in the way they select the closest
neighbor in each cone). This is the first such separation between a Yao and
$\Theta$-graph with the same number of cones. We also give a lower bound of
$2.87$ on the spanning ratio of $Y_5$. Finally, we revisit the $Y_6$ graph,
which plays a particularly important role as the transition between the graphs
($k > 6$) for which simple inductive proofs are known, and the graphs ($k \le
6$) whose best spanning ratios have been established by complex arguments. Here
we reduce the known spanning ratio of $Y_6$ from $17.6$ to $5.8$, getting
closer to the spanning ratio of 2 established for $\Theta_6$.


title:
Detection of B-mode Polarization in the Cosmic Microwave Background with
  Data from the South Pole Telescope

abstract:
  Gravitational lensing of the cosmic microwave background generates a curl
pattern in the observed polarization. This "B-mode" signal provides a measure
of the projected mass distribution over the entire observable Universe and also
acts as a contaminant for the measurement of primordial gravity-wave signals.
In this Letter we present the first detection of gravitational lensing B modes,
using first-season data from the polarization-sensitive receiver on the South
Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal
by combining E-mode polarization measured by SPTpol with estimates of the
lensing potential from a Herschel-SPIRE map of the cosmic infrared background.
We compare this template to the B modes measured directly by SPTpol, finding a
non-zero correlation at 7.7 sigma significance. The correlation has an
amplitude and scale-dependence consistent with theoretical expectations, is
robust with respect to analysis choices, and constitutes the first measurement
of a powerful cosmological observable.


title:
Improved characterisation of intra-night optical variability of
  prominent AGN classes

abstract:
  The incidence of intra-night optical variability (INOV) is known to to differ
significantly among different classes of powerful active galactic nuclei (AGN).
A number of statistical methods have been employed in the literature for
testing the presence of INOV in the light curves, sometimes leading to
discordant results. In this paper we compare the INOV characteristics of six
prominent classes of AGN, as evaluated using three commonly used statistical
tests, namely the $\chi^2-$test, the modified $C-$test and the $F-$test, which
has recently begun to gain popularity. The AGN classes considered are:
radio-quiet quasars (RQQs), radio-intermediate quasars (RIQs), lobe-dominated
quasars (LDQs), low optical polarization core-dominated quasars (LPCDQs), high
optical polarization core-dominated quasars (HPCDQs), and TeV blazars. Our
analysis is based on a large body of AGN monitoring data, involving 262
sessions of intra-night monitoring of a total 77 AGN, using 1-2 metre class
optical telescopes located in India. In order to compare the usefulness of the
statistical tests, we have also subjected them to a `sanity check' by comparing
the number of false positives yielded by each test with the corresponding
statistical prediction. The present analysis is intended to serve as a
benchmark for future INOV studies of AGN of different classes.


title: Multiloop Integrand Reduction for Dimensionally Regulated Amplitudes

abstract:
  We present the integrand reduction via multivariate polynomial division as a
natural technique to encode the unitarity conditions of Feynman amplitudes. We
derive a recursive formula for the integrand reduction, valid for arbitrary
dimensionally regulated loop integrals with any number of loops and external
legs, which can be used to obtain the decomposition of any integrand
analytically with a finite number of algebraic operations. The general results
are illustrated by applications to two-loop Feynman diagrams in QED and QCD,
showing that the proposed reduction algorithm can also be seamlessly applied to
integrands with denominators appearing with arbitrary powers.