title:
Site-Percolation Threshold of Carbon Nanotube Fibers: Fast Inspection of
  Percolation with Markov Stochastic Theory

abstract:
  We present a site-percolation model based on a modified FCC lattice, as well
as an efficient algorithm of inspecting percolation which takes advantage of
the Markov stochastic theory, in order to study the percolation threshold of
carbon nanotube (CNT) fibers. Our Markov-chain based algorithm carries out the
inspection of percolation by performing repeated sparse matrix-vector
multiplications, which allows parallelized computation to accelerate the
inspection for a given configuration. With this approach, we determine that the
site-percolation transition of CNT fibers occurs at p_c =0.1533+-0.0013, and
analyze the dependence of the effective percolation threshold (corresponding to
0.5 percolation probability) on the length and the aspect ratio of a CNT fiber
on a finite-size-scaling basis. We also discuss the aspect ratio dependence of
percolation probability with various values of p (not restricted to p_c).


title: Synthetic hydrogen spectra of prominence oscillations

abstract:
  Context. Prominence oscillations have been mostly detected using Doppler
velocity, although there are also claimed detections by means of periodic
variations in half-width or line intensity. However, scarce observational
evidence exists about simultaneous detection of oscillations in several
spectral indicators. Aims. Our main aim here is to explore the relationship
between spectral indicators, such as Doppler shift, line intensity, and line
half-width, and the linear perturbations excited in a simple prominence model.
Methods. Our equilibrium background model consists of a bounded, homogeneous
slab, which is permeated by a transverse magnetic field, having prominence-like
physical properties. Assuming linear perturbations, the dispersion relation for
fast and slow modes has been derived, as well as the perturbations for the
different physical quantities. These perturbations have been used as the input
variables in a one-dimensional radiative transfer code, which calculates the
full spectral profile of the hydrogen H-alpha and H-beta lines. Results. We
have found that different oscillatory modes produce spectral indicator
variations in different magnitudes. Detectable variations in the Doppler
velocity were found for the fundamental slow mode only. Substantial variations
in the H-beta line intensity were found for specific modes. Other modes lead to
lower and even undetectable parameter variations. Conclusions. To perform
prominence seismology, analysis of the H-alpha and H-beta spectral line
parameters could be a good tool to detect and identify oscillatory modes.


title: Model theoretic properties of the Urysohn sphere

abstract:
  We characterize model theoretic properties of the Urysohn sphere as a metric
structure in continuous logic. In particular, our first main result shows that
the theory of the Urysohn sphere is $\text{SOP}_n$ for all $n\geq 3$, but does
not have the fully finite strong order property. Our second main result is a
geometric characterization of dividing independence in the theory of the
Urysohn sphere. We further show that this characterization satisfies the
extension axiom, and so forking and dividing are the same for complete types.
Our results require continuous analogs of several tools and notions in
classification theory. While many of these results are undoubtedly known to
researchers in the field, they have not previously appeared in publication.
Therefore, we include a full exposition of these results for general continuous
theories.


title: Lifshitz black holes in Einstein-Yang-Mills theory

abstract:
  We find that the four dimensional cosmological Einstein-Yang-Mills theory
with $SU(2)$ gauge group admits Lifshitz spacetime as a base solution for the
dynamical exponent $z>1$. Motivated by this, we next demonstrate numerically
that the field equations admit black hole solutions which behave regularly on
the horizon and at spatial infinity for different horizon topologies. The
solutions depend on one parameter, the strength of the gauge field at the
horizon, which is fine-tuned to capture the Lifshitz asymptotics at infinity.
We also discuss the behavior of solutions and the change in Hawking temperature
for black holes that are large or small with respect to the length scale $L$,
which is itself fixed by the value of the cosmological constant.


title: 10 Simple Rules for the Care and Feeding of Scientific Data

abstract:
  This article offers a short guide to the steps scientists can take to ensure
that their data and associated analyses continue to be of value and to be
recognized. In just the past few years, hundreds of scholarly papers and
reports have been written on questions of data sharing, data provenance,
research reproducibility, licensing, attribution, privacy, and more, but our
goal here is not to review that literature. Instead, we present a short guide
intended for researchers who want to know why it is important to "care for and
feed" data, with some practical advice on how to do that.


title:
Implementing and Automating Fixed-Form Variational Posterior
  Approximation through Stochastic Linear Regression

abstract:
  We recently proposed a general algorithm for approximating nonstandard
Bayesian posterior distributions by minimization of their Kullback-Leibler
divergence with respect to a more convenient approximating distribution. In
this note we offer details on how to efficiently implement this algorithm in
practice. We also suggest default choices for the form of the posterior
approximation, the number of iterations, the step size, and other user choices.
By using these defaults it becomes possible to construct good posterior
approximations for hierarchical models completely automatically.


title: Regular black hole metrics and the weak energy condition

abstract:
  In this work we construct a family of spherically symmetric, static, charged
regular black hole metrics in the context of Einstein-nonlinear electrodynamics
theory. The construction of the charged regular black hole metrics is based on
three requirements: (a) the weak energy condition should be satisfied, (b) the
energy-momentum tensor should have the symmetry $T^{0}_{0}=T^{1}_{1}$, and (c)
these metrics have to asymptotically behave as the Reissner-Nordstr\"{o}m black
hole metric. In addition, these charged regular black hole metrics depend on
two parameters which for specific values yield regular black hole metrics that
already exist in the literature. Furthermore, by relaxing the third
requirement, we construct more general regular black hole metrics which do not
behave asymptotically as a Reissner-Nordstr\"{o}m black hole metric.


title:
Differential ultrafast all-optical switching of the resonances of a
  micropillar cavity

abstract:
  We perform frequency- and time-resolved all-optical switching of a GaAs-AlAs
micropillar cavity using an ultrafast pump-probe setup. The switching is
achieved by two-photon excitation of free carriers. We track the cavity
resonances in time with a high frequency resolution. The pillar modes exhibit
simultaneous frequency shifts, albeit with markedly different maximum switching
amplitudes and relaxation dynamics. These differences stem from the
non-uniformity of the free carrier density in the micropillar, and are well
understood by taking into account the spatial distribution of injected free
carriers, their spatial diffusion and surface recombination at micropillar
sidewalls.


title:
Prediction of temperature distribution in turbulent Rayleigh-Benard
  convection

abstract:
  A quantitative theory is developed for the vertical mean temperature profile
(MTP) in turbulent Rayleigh-Benard convection (RBC), which explains the recent
experimental and numerical observations of a logarithmic law by Ahlers et
al.(Phys. Rev. Lett., 2012). A multi-layer model is formulated and quantified,
whose predictions agree with DNS and experimental data for the Rayleigh-number
(Ra) over seven decades. In particular, a thermal buffer layer follows a 1/7
scaling like the previously postulated mixing zone (Procaccia et al, Phys. Rev.
A,1991), and yields a Ra-dependent log law constant. A new parameterization of
Nu(Ra) dependence is proposed, based on the present multi-layer quantification
of the bulk MTP.


title:
Distinguishing noise from chaos: objective versus subjective criteria
  using Horizontal Visibility Graph

abstract:
  A recently proposed methodology called the Horizontal Visibility Graph (HVG)
[Luque {\it et al.}, Phys. Rev. E., 80, 046103 (2009)] that constitutes a
geometrical simplification of the well known Visibility Graph algorithm [Lacasa
{\it et al.\/}, Proc. Natl. Sci. U.S.A. 105, 4972 (2008)], has been used to
study the distinction between deterministic and stochastic components in time
series [L. Lacasa and R. Toral, Phys. Rev. E., 82, 036120 (2010)].
Specifically, the authors propose that the node degree distribution of these
processes follows an exponential functional of the form $P(\kappa)\sim
\exp(-\lambda~\kappa)$, in which $\kappa$ is the node degree and $\lambda$ is a
positive parameter able to distinguish between deterministic (chaotic) and
stochastic (uncorrelated and correlated) dynamics. In this work, we investigate
the characteristics of the node degree distributions constructed by using HVG,
for time series corresponding to $28$ chaotic maps and $3$ different stochastic
processes. We thoroughly study the methodology proposed by Lacasa and Toral
finding several cases for which their hypothesis is not valid. We propose a
methodology that uses the HVG together with Information Theory quantifiers. An
extensive and careful analysis of the node degree distributions obtained by
applying HVG allow us to conclude that the Fisher-Shannon information plane is
a remarkable tool able to graphically represent the different nature,
deterministic or stochastic, of the systems under study.


title: Structure of Leavitt path algebras of polynomial growth

abstract:
  We determine the structure of Leavitt path algebras of polynomial growth and
discuss their automorphisms and involutions.


title: N.C. Rana: The Life of a `Comet' in the Astrophysical World

abstract:
  Narayan Chandra Rana, a person with extraordinary potential from a remote
village of Bengal, India, came into the limelight of the international
scientific world through his exceptional talent, zeal and courage. In his very
short life-span, he excelled not only into various branches of astrophysics,
but also took a leading role in science popularization, text book writing etc.
In this paper, life and works of that budding scientist of India have been
discussed from multifarious viewpoints.


title:
Quantum Algorithms for Nearest-Neighbor Methods for Supervised and
  Unsupervised Learning

abstract:
  We present several quantum algorithms for performing nearest-neighbor
learning. At the core of our algorithms are fast and coherent quantum methods
for computing distance metrics such as the inner product and Euclidean
distance. We prove upper bounds on the number of queries to the input data
required to compute these metrics. In the worst case, our quantum algorithms
lead to polynomial reductions in query complexity relative to the corresponding
classical algorithm. In certain cases, we show exponential or even
super-exponential reductions over the classical analog. We study the
performance of our quantum nearest-neighbor algorithms on several real-world
binary classification tasks and find that the classification accuracy is
competitive with classical methods.


title: Drinfeld J Presentation of Twisted Yangians

abstract:
  We present a quantization of a Lie coideal structure for twisted half-loop
algebras of finite-dimensional simple complex Lie algebras. We obtain algebra
closure relations of twisted Yangians in Drinfeld J presentation for all
symmetric pairs of simple Lie algebras and for simple twisted even half-loop
Lie algebras. We provide the explicit form of the closure relations for twisted
Yangians in Drinfeld J presentation for the ${\mathfrak{sl}}_3$ Lie algebra.


title: Hyper-extensions in metric fixed point theory

abstract:
  We apply a modern axiomatic system of nonstandard analysis in metric fixed
point theory. In particular, we formulate a nonstandard iteration scheme for
nonexpansive mappings and present a nonstandard approach to fixed-point
problems in direct sums of Banach spaces.


title: B -> K* mu+ mu- optimised observables in the MSSM

abstract:
  We provide a detailed analysis of the impact of the newly measured optimised
observables in the B -> K* mu+ mu- decay by the LHCb experiment. The analysis
is performed in the MSSM, both in the context of the usual constrained
scenarios, and in the context of a more general set-up where the SUSY partner
masses are independent. We show that the global agreement of the MSSM solutions
with the data is still very good. Nevertheless, especially in the constrained
scenarios, the limits from B -> K* mu+ mu- are now very strong, and are at the
same level as the well-known b -> s gamma constraints. We describe the
implications of the B -> K* mu+ mu- measurements both on the Wilson
coefficients and on the SUSY parameters.


title:
Spectrum of a diffusion operator with coefficient changing sign over a
  small inclusion

abstract:
  We study a spectral problem $(\mathscr{P}^{\delta})$ for a diffusion like
equation in a 3D domain $\Omega$. The main originality lies in the presence of
a parameter $\sigma^{\delta}$, whose sign changes on $\Omega$, in the principal
part of the operator we consider. More precisely, $\sigma^{\delta}$ is positive
on $\Omega$ except in a small inclusion of size $\delta>0$. Because of the
sign-change of $\sigma^{\delta}$, for all $\delta>0$ the spectrum of
$(\mathscr{P}^{\delta})$ consists of two sequences converging to $\pm\infty$.
However, at the limit $\delta=0$, the small inclusion vanishes so that there
should only remain positive spectrum for $(\mathscr{P}^{\delta})$. What happens
to the negative spectrum? In this paper, we prove that the positive spectrum of
$(\mathscr{P}^{\delta})$ tends to the spectrum of the problem without the small
inclusion. On the other hand, we establish that each negative eigenvalue of
$(\mathscr{P}^{\delta})$ behaves like $\delta^{-2}\mu$ for some constant
$\mu<0$. We also show that the eigenfunctions associated with the negative
eigenvalues are localized around the small inclusion. We end the article
providing 2D numerical experiments illustrating these results.


title: Anomalous light absorption around subwavelength apertures in metal films

abstract:
  In this work, we study the heat dissipated at metal surfaces by the
electromagnetic field scattered by isolated subwavelength apertures in metal
screens. In contrast to our common belief that the intensity of waves created
by local sources should decrease with the distance from the sources, we reveal
that the dissipated heat at the surface remains constant over a broad spatial
interval of a few tens of wavelengths. This behavior which occurs for noble
metals at near infrared wavelengths is observed with nonintrusive
thermoreflectance measurements and is analyzed with an analytical model which
underlines the intricate role played by quasi-cylindrical waves in the
phenomenon. Additionally, computational results reveal that the absorption
plateau is an intrinsic property that occurs for a large variety of topologies,
irrespective of aperture shapes.


title: Emergent cosmological constant from colliding electromagnetic waves

abstract:
  In this study we advocate the view that the cosmological constant is of
electromagnetic (em) origin, which can be generated from the collision of em
shock waves coupled with gravitational shock waves. The wave profiles that
participate in the collision have different amplitudes. It is shown that,
circular polarization with equal amplitude waves does not generate cosmological
constant. We also prove that the generation of the cosmological constant is
related to the linear polarization. The addition of cross polarization
generates no cosmological constant. Depending on the value of the wave
amplitudes, the generated cosmological constant can be positive or negative. We
show additionally that, the collision of nonlinear em waves in a particular
class of Born-Infeld theory also yields a cosmological constant.


title: High precision predictions for exclusive $VH$ production at the LHC

abstract:
  We present a resummation-improved prediction for $VH$ + 0 jets production at
the Large Hadron Collider. We focus on highly-boosted final states in the
presence of jet veto to suppress the $t{\bar t}$ background. In this case,
conventional fixed-order calculations are plagued by the existence of large
Sudakov logarithms $\alpha_s^n \log^m (p_T^{veto}/Q)$ for $Q\sim m_V + m_H$
which lead to unreliable predictions as well as large theoretical
uncertainties, and thus limit the accuracy when comparing experimental
measurements to the Standard Model. In this work, we show that the resummation
of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined
with the next-to-next-to-leading order calculation, reduces the scale
uncertainty and stabilizes the perturbative expansion in the region where the
vector bosons carry large transverse momentum. Our result improves the
precision with which Higgs properties can be determined from LHC measurements
using boosted Higgs techniques.


title: Steady-State Axisymmetric MHD Solutions with Various Boundary Conditions

abstract:
  Axisymmetric magnetohydrodynamics (MHD) can be invoked for describing
astrophysical magnetized flows and formulated to model stellar magnetospheres
including main sequence stars (e.g. the Sun), compact stellar objects [e.g.
magnetic white dwarfs (MWDs), radio pulsars, anomalous X-ray pulsars (AXPs),
magnetars, isolated neutron stars etc.], and planets as a major step forward
towards a full three-dimensional model construction. Using powerful and
reliable numerical solvers based on two distinct finite-difference method (FDM)
and finite-element method (FEM) schemes of algorithm, we examine axisymmetric
steady-state or stationary MHD models in Throumoulopoulos & Tasso (2001),
finding that their separable semi-analytic nonlinear solutions are actually not
unique given their specific selection of several free functionals and chosen
boundary conditions. The multiplicity of nonlinear steady MHD solutions gives
rise to differences in the total energies contained in the magnetic fields and
flow velocity fields as well as in the asymptotic behaviours approaching
infinity, which may in turn explain why numerical solvers tend to converge to a
nonlinear solution with a lower energy than the corresponding separable
semi-analytic one. By properly adjusting model parameters, we invoke
semi-analytic and numerical solutions to describe different kind of scenarios,
including nearly parallel case and the situation in which the misalignment
between the fluid flow and magnetic field is considerable. We propose that
these MHD models are capable of describing the magnetospheres of MWDs as
examples of applications with moderate conditions (including magnetic field)
where the typical values of several important parameters are consistent with
observations. We discuss the challenges of developing numerical extrapolation
MHD codes in view of nonlinear degeneracy.


title: Two active states of the narrow-line gamma-ray-loud AGN GB 1310+487

abstract:
  Previously unremarkable, the extragalactic radio source GB 1310+487 showed a
gamma-ray flare on 2009 November 18, reaching a daily flux of ~10^-6
photons/cm^2/s at energies E>100 MeV and becoming one of the brightest GeV
sources for about two weeks. Its optical spectrum is not typical for a blazar,
instead, it resembles those of narrow emission-line galaxies. We investigate
changes of the object's radio-to-GeV spectral energy distribution (SED) during
and after the prominent GeV flare with the aim to determine the nature of the
object and constrain the origin of the variable high-energy emission. The data
collected by the Fermi and AGILE satellites at gamma-ray energies, Swift at
X-ray and ultraviolet, Kanata, NOT, and Keck telescopes at optical, OAGH and
WISE at infrared, and IRAM 30m, OVRO 40m, Effelsberg 100m, RATAN-600, and VLBA
at radio, are analysed together to trace the SED evolution on timescales of
months. The gamma-ray/radio-loud narrow-line active galactic nucleus (AGN) is
located at redshift z=0.638. It is shining through an unrelated foreground
galaxy at z=0.500. The AGN light is likely amplified by a factor of a few
because of gravitational lensing. The AGN SED shows a two-humped structure
typical of blazars and gamma-ray-loud NLSy1 galaxies, with the high-energy
(inverse-Compton) emission dominating by more than an order of magnitude over
the low-energy (synchrotron) emission during gamma-ray flares. The difference
between the two SED humps is smaller during the low-activity state. Fermi
observations reveal a strong correlation between the gamma-ray flux and
spectral index, with the hardest spectrum observed during the brightest
gamma-ray state. If the gamma-ray flux is a mixture of synchrotron self-Compton
(SSC) and external Compton (EC) emission, the observed GeV spectral variability
may result from varying relative contributions of these two emission
components.


title: Two-photon spin states and entanglement states

abstract:
  In this paper, we have given the spin states of two-photon, which are
expressed by the quadratic combination of two single photon spin states, they
are a kind of quantum expression. Otherwise, we give all entanglement states of
two-photon, which are different from the xanzsd classical polarization vector
expression of two-photon entanglement state.


title: Ontology - Based Dynamic Business Process Customization

abstract:
  The interaction between business models is used in consumer centric manner
instead of using a producer centric approach for customizing the business
process in cloud environment. The knowledge based human semantic web is used
for customizing the business process It introduces the Human Semantic Web as a
conceptual interface, providing human-understandable semantics on top of the
ordinary Semantic Web, which provides machine-readable semantics based on RDF
in this mismatching is a major problem. To overcome this following technique
automatic customization detection is an automated process of detecting possible
elements or variables of a business process that needto be especially treated
in order to suit the requirement of the other process. To the business
processto be customized as the primary business process and those that it
collaborates with as secondary business process or SBP Automatic customization
enactment is an automated process of taking actions to perform the
customization on the PBP according to the detected customization spots and the
automatic reasoning on the customization conceptualization knowledge framework.
The process of customizing businessprocesses by composite the web pages by
using web service.


title:
Stochastic functionals and fluctuation theorem for the multi-kangaroo
  process

abstract:
  We introduce multi-kangaroo Markov processes and provide a general procedure
for evaluating a certain type of stochastic functionals. We calculate
analytically the large deviation properties. Applications include zero-crossing
statistics and stochastic thermodynamics.


title: Seismoelectric effects due to mesoscopic heterogeneities

abstract:
  While the seismic effects of wave-induced fluid flow due to mesoscopic
heterogeneities have been studied for several decades, the role played by these
types of heterogeneities on seismoelectric phenomena is largely unexplored. To
address this issue, we have developed a novel methodological framework which
allows for the coupling of wave-induced fluid flow, as inferred through
numerical oscillatory compressibility tests, with the pertinent seismoelectric
conversion mechanisms. Simulating the corresponding response of a
water-saturated sandstone sample containing mesoscopic fractures, we
demonstrate for the first time that these kinds of heterogeneities can produce
measurable seismoelectric signals under typical laboratory conditions. Given
that this phenomenon is sensitive to key hydraulic and mechanical properties,
we expect that the results of this pilot study will stimulate further
exploration on this topic in several domains of the Earth, environmental, and
engineering sciences.


title:
The effect of Landau-Zener tunnelings on the nonlinear dynamics of cold
  atoms in a modulated laser field

abstract:
  We study the motion of a cold atom in a frequency-modulated standing laser
wave. If the detuning between the atomic electronic transition and the field is
large, the atom moves in a modulated optical potential demonstrating known
classical nonlinear effects such as chaos and nonlinear resonances. If the
atom-field detuning is small, then two optical potentials emerge in the system,
and the atom performs Landau-Zener (LZ) tunnelings between them. It is a
radically non-classical behavior. However, we show that classical nonlinear
structures in system's phase space (KAM-tori and chaotic layers) survive.
Quantum effect of LZ tunnelings only induces small random jumps of trajectories
between these structures (dynamical tunneling).


title: The Absolute Magnitude Distribution of Kuiper Belt Objects

abstract:
  Here we measure the absolute magnitude distributions (H-distribution) of the
dynamically excited and quiescent (hot and cold) Kuiper Belt objects (KBOs),
and test if they share the same H-distribution as the Jupiter Trojans. From a
compilation of all useable ecliptic surveys, we find that the KBO
H-distributions are well described by broken power-laws. The cold population
has a bright-end slope, $\alpha_{\textrm{1}}=1.5_{-0.2}^{+0.4}$, and break
magnitude, $H_{\textrm{B}}=6.9_{-0.2}^{+0.1}$ (r'-band). The hot population has
a shallower bright-end slope of, $\alpha_{\textrm{1}}=0.87_{-0.2}^{+0.07}$, and
break magnitude $H_{\textrm{B}}=7.7_{-0.5}^{+1.0}$. Both populations share
similar faint end slopes of $\alpha_2\sim0.2$. We estimate the masses of the
hot and cold populations are $\sim0.01$ and $\sim3\times10^{-4} \mbox{
M$_{\bigoplus}$}$. The broken power-law fit to the Trojan H-distribution has
$\alpha_\textrm{1}=1.0\pm0.2$, $\alpha_\textrm{2}=0.36\pm0.01$, and
$H_{\textrm{B}}=8.3$. The KS test reveals that the probability that the Trojans
and cold KBOs share the same parent H-distribution is less than 1 in 1000. When
the bimodal albedo distribution of the hot objects is accounted for, there is
no evidence that the H-distributions of the Trojans and hot KBOs differ. Our
findings are in agreement with the predictions of the Nice model in terms of
both mass and H-distribution of the hot and Trojan populations. Wide field
survey data suggest that the brightest few hot objects, with
$H_{\textrm{r'}}\lesssim3$, do not fall on the steep power-law slope of fainter
hot objects. Under the standard hierarchical model of planetesimal formation,
it is difficult to account for the similar break diameters of the hot and cold
populations given the low mass of the cold belt.


title: Jet Shapes with the Broadening Axis

abstract:
  Broadening is a classic jet observable that probes the transverse momentum
structure of jets. Traditionally, broadening has been measured with respect to
the thrust axis, which is aligned along the (hemisphere) jet momentum to
minimize the vector sum of transverse momentum within a jet. In this paper, we
advocate measuring broadening with respect to the "broadening axis", which is
the direction that minimizes the scalar sum of transverse momentum within a
jet. This approach eliminates many of the calculational complexities arising
from recoil of the leading parton, and observables like the jet angularities
become recoil-free when measured using the broadening axis. We derive a simple
factorization theorem for broadening-axis observables which smoothly
interpolates between the thrust-like and broadening-like regimes. We argue that
the same factorization theorem holds for two-point energy correlation functions
as well as for jet shapes based on a "winner-take-all axis". Using kinked
broadening axes, we calculate event-wide angularities in e+e- collisions with
next-to-leading logarithmic resummation. Defining jet regions using the
broadening axis, we also calculate the global logarithms for angularities
within a single jet. We find good agreement comparing our calculations both to
showering Monte Carlo programs and to automated resummation tools. We give a
brief historical perspective on the broadening axis and suggest ways that
broadening-axis observables could be used in future jet substructure studies at
the Large Hadron Collider.


title: The impact of rotation on the line profiles of Wolf-Rayet stars

abstract:
  Massive Wolf-Rayet stars are recognized today to be in a very common, but
short, evolutionary phase of massive stars. While our understanding of
Wolf-Rayet stars has increased dramatically over the past decades, it remains
unclear whether rapid rotators are among them. There are various indications
that rapidly rotating Wolf-Rayet stars should exist. Unfortunately, due to
their expanding atmospheres, rotational velocities of Wolf-Rayet stars are very
difficult to measure. However, recently observed spectra of several Wolf-Rayet
stars reveal peculiarly broad and round emission lines. Could these spectra
imply rapid rotation?
  In this work, we model the effects of rotation on the atmospheres of
Wolf-Rayet stars. We further investigate whether the peculiar spectra of five
Wolf-Rayet stars may be explained with the help of stellar rotation, infer
appropriate rotation parameters, and discuss the implications of our results.
We make use of the Potsdam Wolf-Rayet (PoWR) non-LTE model atmosphere code.
Since the observed spectra of Wolf-Rayet stars are mainly formed in their
expanding atmospheres, rotation must be accounted for with a 3D integration
scheme of the formal integral. For this purpose, we assume a rotational
velocity field consisting of an inner co-rotating domain and an outer domain,
where the angular momentum is conserved. We find that rotation can reproduce
the unique spectra analyzed here. However, the inferred rotational velocities
at the stellar surface are large (~200 km/s), and the inferred co-rotation
radii (~10 stellar radii) suggest the existence of very strong photospheric
magnetic fields (~20 kG).


title: Quantum Quenches in the Thermodynamic Limit

abstract:
  We introduce a linked-cluster based computational approach that allows one to
study quantum quenches in lattice systems in the thermodynamic limit. This
approach is used to study quenches in one-dimensional lattices. We provide
evidence that, in the thermodynamic limit, thermalization occurs in the
nonintegrable regime but fails at integrability. A phase transitionlike
behavior separates the two regimes.


title:
The Study of TeV Variability and Duty Cycle of Mrk 421 from 3 Years of
  Observations with the Milagro Observatory

abstract:
  TeV flaring activity with time scales as short as tens of minutes and an
orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421).
The TeV emission from Mrk 421 is believed to be produced by leptonic
synchrotron self-Compton (SSC) emission. In this scenario, correlations between
the X-ray and the TeV fluxes are expected, TeV orphan flares are hardly
explained and the activity (measured as duty cycle) of the source at TeV
energies is expected to be equal or less than that observed in X-rays if only
SSC is considered. To estimate the TeV duty cycle of Mrk 421 and to establish
limits on its variability at different time scales, we continuously observed
Mrk 421 with the Milagro observatory. Mrk 421 was detected by Milagro with a
statistical significance of 7.1 standard deviations between 2005 September 21
and 2008 March 15. The observed spectrum is consistent with previous
observations by VERITAS. We estimate the duty cycle of Mrk 421 for energies
above 1 TeV for different hypothesis of the baseline flux and for different
flare selections and we compare our results with the X-ray duty cycle estimated
by Resconi et al. 2009. The robustness of the results is discussed.


title:
Effects of neutral $Z^{\prime}$ boson in $B_{s} \to \phi \ell^{+}
  \ell^{-}$ decay with polarized $\phi$ and the unpolarized and polarized $CP$
  violation asymmetry

abstract:
  The effects of new neutral $Z^\prime$ boson in
$B_{s}\to\phi\ell^{+}\ell^{-}$, when $\phi$ is longitudinal or transverse
polarized, are studied. In addition, the implications of $Z^{\prime}$ boson on
the unpolarized and polarized $CP$ violation asymmetries, with reference to
lepton, are also presented. It is observed that the branching ratio with
polarized $\phi$ are quite sensitive to the $Z^{\prime}$ contributions which
are coming through the modification of Wilson coefficients $C^{eff}_{9}$ and
$C_{10}$. Moreover, the off-diagonal elements of the chiral $Z^{\prime}$
couplings contain new weak phase $\phi_{sb}$ that provide a new source of $CP$
violation. Keeping in view that in the FCNC transitions the $CP$ violation
asymmetries are highly suppressed in the SM, we have studied the unpolarized
and polarized $CP$ violation asymmetries in $B_{s}\to\phi\ell^{+}\ell^{-}$
decays. Our results indicate that these $CP$ violation asymmetries are
remarkably significant and can attribute the any new physics coming through the
$Z^{\prime}$ boson. It is hoped that the accurate measurements of these
asymmetries will not only help us to establish NP but will also give a chance
to determine the precise values of the coupling parameters of the $Z^{\prime}$
boson.


title:
Estimation of Partially Linear Regression Model under Partial
  Consistency Property

abstract:
  In this paper, utilizing recent theoretical results in high dimensional
statistical modeling, we propose a model-free yet computationally simple
approach to estimate the partially linear model $Y=X\beta+g(Z)+\varepsilon$.
Motivated by the partial consistency phenomena, we propose to model $g(Z)$ via
incidental parameters. Based on partitioning the support of $Z$, a simple local
average is used to estimate the response surface. The proposed method seeks to
strike a balance between computation burden and efficiency of the estimators
while minimizing model bias. Computationally this approach only involves least
squares. We show that given the inconsistent estimator of $g(Z)$, a root $n$
consistent estimator of parametric component $\beta$ of the partially linear
model can be obtained with little cost in efficiency. Moreover, conditional on
the $\beta$ estimates, an optimal estimator of $g(Z)$ can then be obtained
using classic nonparametric methods. The statistical inference problem
regarding $\beta$ and a two-population nonparametric testing problem regarding
$g(Z)$ are considered. Our results show that the behavior of test statistics
are satisfactory. To assess the performance of our method in comparison with
other methods, three simulation studies are conducted and a real dataset about
risk factors of birth weights is analyzed.


title: Charged Higgs Discovery in the W plus "Dark" Vector Boson Decay Mode

abstract:
  In Two Higgs doublet extensions of the Standard Model, flavor-changing
neutral current constraints can be addressed by introducing a U(1)' gauge
symmetry, under which the Higgs doublets carry different charges. That scenario
implies the presence of a H^\pm W^\mp Z' vertex at tree level. For the light
"dark" Z model (Z'=Z_d) with m_{Z_d} < 10 GeV, such a coupling leads to the
dominant decay mode H^\pm \to W^\pm + Z_d (for m_{H^\pm} \lsim 175 GeV), rather
than the usual type I model decay H^\pm \to \tau^\pm \nu, for a broad range of
parameters. We find that current analyses do not place significant bounds on
this scenario. Over much of the parameter space considered, the decay of a
pair-produced t ({\bar t}) into H^+ b (H^- {\bar b}) provides the dominant
H^\pm production. Analysis of available LHC data can likely cover significant
ranges of our parameters, if Z_d \to \mu^+\mu^- has a branching ratio of \sim
20%. If the Z_d decays mainly invisibly then probing the entire relevant
parameter space would likely require additional data from future LHC runs. We
briefly discuss the phenomenology for m_{H^\pm}\gsim 175 GeV.


title: NextBestOnce: Achieving Polylog Routing despite Non-greedy Embeddings

abstract:
  Social Overlays suffer from high message delivery delays due to insufficient
routing strategies. Limiting connections to device pairs that are owned by
individuals with a mutual trust relationship in real life, they form topologies
restricted to a subgraph of the social network of their users. While
centralized, highly successful social networking services entail a complete
privacy loss of their users, Social Overlays at higher performance represent an
ideal private and censorship-resistant communication substrate for the same
purpose.
  Routing in such restricted topologies is facilitated by embedding the social
graph into a metric space. Decentralized routing algorithms have up to date
mainly been analyzed under the assumption of a perfect lattice structure.
However, currently deployed embedding algorithms for privacy-preserving Social
Overlays cannot achieve a sufficiently accurate embedding and hence
conventional routing algorithms fail. Developing Social Overlays with
acceptable performance hence requires better models and enhanced algorithms,
which guarantee convergence in the presence of local optima with regard to the
distance to the target.
  We suggest a model for Social Overlays that includes inaccurate embeddings
and arbitrary degree distributions. We further propose NextBestOnce, a routing
algorithm that can achieve polylog routing length despite local optima. We
provide analytical bounds on the performance of NextBestOnce assuming a
scale-free degree distribution, and furthermore show that its performance can
be improved by more than a constant factor when including Neighbor-of-Neighbor
information in the routing decisions.


title:
Implications of GRB 130603B and its macronova for r-process
  nucleosynthesis

abstract:
  The tentative identification of a Li-Paczynski macronova following the short
GRB 130603B indicated that a few hundredths of a solar mass of neutron star
matter were ejected and that this ejected mass has radioactively decayed into
heavy r-process elements. If correct, this confirms long standing predictions
(Eichler, Livio, Piran and Schramm 1989) that on the one hand, sGRBs are
produced in compact binary mergers (CBMs) and on the other hand that these
events are significant and possibly dominant sources of the heavy (A>130)
r-process nuclei. Assuming that this interpretation is correct we obtain a
lower limit of 0.02 m_sun on the ejected mass. Using the current estimates of
the rate of sGRBs and with a beaming factor of 50, mergers associated with
sGRBs can produce all the observed heavy r-process material in the Universe. We
confront this conclusion with cosmochemistry and show that even though such
events are rare, mixing is sufficient to account for the current homogeneous
distribution of r-process material in the Galaxy. However, the appearance of
significant amounts of Eu in some very low metallicity stars requires that some
mergers took place very early on, namely with a very short time delay after the
earliest star formation episodes. Alternatively, an additional early
r-processsource may have contributed at that early stage. Finally, we note that
evidence for short lived {244}^Pu in the very early solar system suggests that
a merger of this kind took place within the vicinity of the solar system
shortly (a few hundred million years) before its formation.


title:
Effects of short-ranged interactions on the Kane-Mele model without
  discrete particle-hole symmetry

abstract:
  We study the effects of short-ranged interactions on the $Z_2$ topological
insulator phase, also known as the quantum spin Hall phase, in the Kane-Mele
model at half-filling with staggered potentials which explicitly breaks the
discrete particle-hole symmetry. Within Hartree-Fock mean-field analysis, we
conclude that the on-site repulsive interactions help stabilize the topological
phase (quantum spin Hall) against the staggered potentials by enlarging the
regime of the topological phase along the axis of the ratio of the staggered
potential strength and the spin-orbit coupling. In sharp contrast, the on-site
attractive interactions destabilize the topological phase. We also examine the
attractive interaction case by means of the unbiased determinant projector
quantum Monte Carlo and the results are qualitatively consistent with the
Hartree-Fock picture.


title:
Partially Observable Total-Cost Markov Decision Processes with Weakly
  Continuous Transition Probabilities

abstract:
  This paper describes sufficient conditions for the existence of optimal
policies for Partially Observable Markov Decision Processes (POMDPs) with Borel
state, observation, and action sets and with the expected total costs. Action
sets may not be compact and one-step cost functions may be unbounded. The
introduced conditions are also sufficient for the validity of optimality
equations, semi-continuity of value functions, and convergence of value
iterations to optimal values. Since POMDPs can be reduced to Completely
Observable Markov Decision Processes (COMDPs), whose states are posterior state
distributions, this paper focuses on the validity of the above mentioned
optimality properties for COMDPs. The central question is whether transition
probabilities for a COMDP are weakly continuous. We introduce sufficient
conditions for this and show that the transition probabilities for a COMDP are
weakly continuous, if transition probabilities of the underlying Markov
Decision Process are weakly continuous and observation probabilities for the
POMDP are continuous in the total variation. Moreover, the continuity in the
total variation of the observation probabilities cannot be weakened to setwise
continuity. The results are illustrated with counterexamples and examples.


title:
Achievability of Nonlinear Degrees of Freedom in Correlatively Changing
  Fading Channels

abstract:
  A new approach toward the noncoherent communications over the time varying
fading channels is presented. In this approach, the relationship between the
input signal space and the output signal space of a correlatively changing
fading channel is shown to be a nonlinear mapping between manifolds of
different dimensions. Studying this mapping, it is shown that using nonlinear
decoding algorithms for single input-multiple output (SIMO) and multiple input
multiple output (MIMO) systems, extra numbers of degrees of freedom (DOF) are
available. We call them the nonlinear degrees of freedom.


title:
The Multiplicative Structure on Hochschild Cohomology of a Complete
  Intersection

abstract:
  We determine the product structure on Hochschild cohomology of commutative
algebras in low degrees, obtaining the answer in all degrees for complete
intersection algebras. As applications, we consider cyclic extension algebras
as well as Hochschild and ordinary cohomology of finite abelian groups.


title:
Edge proximity-induced magnetoresistance and spin polarization in
  ferromagnetic gated bilayer graphene nanoribbon

abstract:
  Coherent spin-dependent transport through a junction containing of
Normal/Ferromagnetic/Normal bilayer graphene nanoribbon with zigzag edges is
investigated by using Landauer formalism. In a more realistic set-up, the
exchange field is induced by two ferromagnetic insulator strips deposited on
the ribbon edges while a perpendicular electric field is applied by the top
gated electrodes. Our results show that, for antiparallel configuration, a band
gap is opened giving rise a semiconducting behavior, while for parallel
configuration, the band structure has no band gap. As a result, a giant
magnetoresistance is achievable by changing the alignment of induced
magnetization. Application of a perpendicular electric field on the parallel
configuration, results in a spin field-effect transistor where a fully spin
polarization occurs around the Dirac point. To be comparable our results with
the one for monolayer graphene, we demonstrate that the reflection symmetry and
so the parity conservation fails in bilayer graphene nanoribbons with the
zigzag edges.


title: Acustica con una Bic e uno smartphone

abstract:
  A smartphone, with its integrated sensors and cpu, can aid experiments in
many different areas of Physics. We show how the resonant frequencies of a pipe
can be measured using a smartphone and a Bic pen.


title: Majorana Flat Bands in s-Wave Gapless Topological Superconductors

abstract:
  We demonstrate how the non-trivial interplay between spin-orbit coupling and
nodeless $s$-wave superconductivity can drive a fully gapped two-band
topological insulator into a time-reversal invariant gapless topological
superconductor supporting symmetry-protected Majorana flat bands. We
characterize topological phase diagrams by a ${\mathbb Z}_2 \times{\mathbb
Z}_2$ partial Berry-phase invariant, and show that, despite the trivial crystal
geometry, no unique bulk-boundary correspondence exists. We trace this behavior
to the anisotropic quasiparticle bulk gap closing, linear vs. quadratic, and
argue that this provides a unifying principle for gapless topological
superconductivity. Experimental implications for tunneling conductance
measurements are addressed, relevant for lead chalcogenide materials.


title: Non-Rigid Parabolic Geometries of Monge Type

abstract:
  In this paper we study a novel class of parabolic geometries which we call
parabolic geometries of Monge type. These parabolic geometries are defined by
special gradings of simple Lie algebras, namely, gradings with the property
that their -1 component contains a nonzero co-dimension 1 abelian subspace
whose bracket with its complement is non-degenerate. We completely classify the
simple Lie algebras with such gradings in terms of elementary properties of the
defining set of simple roots. We then characterize those parabolic geometries
of Monge type which are non-rigid in the sense that, apart from the flat
models, they have nonzero harmonic curvatures in positive weights. Standard
models of all non-rigid parabolic geometries of Monge type are then described
by under-determined ODE systems. The full symmetry algebras for these
under-determined ODE systems are explicitly calculated; surprisingly, these
symmetries are all just prolonged point symmetries.


title: A Second Look at Counting Triangles in Graph Streams (revised)

abstract:
  In this paper we present improved results on the problem of counting
triangles in edge streamed graphs. For graphs with $m$ edges and at least $T$
triangles, we show that an extra look over the stream yields a two-pass
treaming algorithm that uses $O(\frac{m}{\eps^{2.5}\sqrt{T}}\polylog(m))$ space
and outputs a $(1+\eps)$ approximation of the number of triangles in the graph.
This improves upon the two-pass streaming tester of Braverman, Ostrovsky and
Vilenchik, ICALP 2013, which distinguishes between triangle-free graphs and
graphs with at least $T$ triangle using $O(\frac{m}{T^{1/3}})$ space. Also, in
terms of dependence on $T$, we show that more passes would not lead to a better
space bound. In other words, we prove there is no constant pass streaming
algorithm that distinguishes between triangle-free graphs from graphs with at
least $T$ triangles using $O(\frac{m}{T^{1/2+\rho}})$ space for any constant
$\rho \ge 0$.


title: Can a light Higgs impostor hide in composite gauge models?

abstract:
  The frequently discussed strongly interacting gauge theory with a fermion
flavor doublet in the two-index symmetric (sextet) representation of the SU(3)
color gauge group is investigated. In previous studies the chiral condensate
and the mass spectrum were shown to be consistent with chiral symmetry breaking
($\chi$SB) at vanishing fermion mass. The recently reported $\beta$-function is
not inconsistent with this observation, suggesting that the model is very close
to the conformal window and a light "Higgs impostor" could emerge as a
composite state. In this work we describe the methodology and preliminary
results of studying the emergence of the light composite scalar with $0^{++}$
quantum numbers.


title:
First-principles study of luminescence in Eu$^{2+}$-doped inorganic
  scintillators

abstract:
  Luminescence in Eu$^{2+}$ activated materials corresponds to a transition
from an excited state where the lowest Eu 5$d$ level is filled with one
electron (often called the (Eu$^{2+}$)$^*$ state) to the ground state with
half-filled 4$f$ shell with seven electrons of the same spin. We have performed
theoretical calculations based on Density Functional Theory to determine the
ground state band structure of Eu-doped materials as well as study the
(Eu$^{2+}$)$^*$ excited state. Calculations were performed on Eu doped
materials, experimentally known to be either scintillators or
non-scintillators, in order to relate theoretically calculable parameters to
experimentally observed properties. Applying criteria previously developed for
Ce-doped systems (A.Canning, A. Chaudhry, R. Boutchko and N.
Gr\o{}nbech-Jensen, Phys. Rev. B Vol.83, 125115 (2011)) to new Eu-doped
materials we developed a list of candidate materials for new bright Eu
activated scintillators. Ba$_2$CsBr$_5$:Eu is an example of a new bright
scintillator from our candidate list that has been synthesized in
microcrystalline powder form. As discussed in our previous paper on Ce-doped
materials this approach was designed as a systematic high-throughput method to
aid in the discovery of new bright scintillator materials by prioritization and
down-selection on the large number of potential new materials.


title:
First-order chiral to non-chiral transition in the angular dependence of
  the upper critical induction of the Scharnberg-Klemm $p$-wave pair state

abstract:
  We calculate the temperature $T$ and angular $(\theta,\phi)$ dependence of
the upper critical induction $B_{c2}(\theta,\phi,T)$ for parallel-spin
superconductors with an axially symmetric $p$-wave pairing interaction pinned
to the lattice and a dominant ellipsoidal Fermi surface (FS). For all FS
anisotropies, the chiral Scharnberg-Klemm state $B_{c2}(\theta,\phi,T)$ exceeds
that of the chiral Anderson-Brinkman-Morel state, and exhibits a kink at
$\theta=\theta^{*}(T,\phi)$, indicative of a first-order transition from its
chiral, nodal-direction behavior to its non-chiral, antinodal-direction
behavior. Applicability to Sr$_2$RuO$_4$, UCoGe, and topological
superconductors such as Cu$_x$Bi$_2$Se$_3$ is discussed.


title:
A Correlation between Star Formation Rate and Average Black Hole
  Accretion in Star-forming Galaxies (Proceeding of IAUS304: Multiwavelength
  AGN Surveys and Studies)

abstract:
  We present the results of recent studies on the co-evolution of galaxies and
the supermassive black holes (SMBHs) using Herschel far-infrared and Chandra
X-ray observations in the Bo\"otes survey region. For a sample of star-forming
(SF) galaxies, we find a strong correlation between galactic star formation
rate and the average SMBH accretion rate in SF galaxies. Recent studies have
shown that star formation and AGN accretion are only weakly correlated for
individual AGN, but this may be due to the short variability timescale of AGN
relative to star formation. Averaging over the full AGN population yields a
strong linear correlation between accretion and star formation, consistent with
a simple picture in which the growth of SMBHs and their host galaxies are
closely linked over galaxy evolution time scales.


title: Veiled Nonlocality and Cosmic Censorship

abstract:
  The premise that consciousness has a quantum mechanical basis or correlate
implies that its workings have a nonlocal component. To check whether
consciousness as an entity leaves a physical trace, we propose that laboratory
searches for such a trace should be for nonlocality, where probabilities do not
conform to local expectations. Starting with the idea that nonlocality may be
veiled as one of the ways cosmic censorship operates, we further argue that in
order to preserve the ordinary objective reality described by local realism and
general relativity, veiled nonlocality and cosmic censorship are indispensable
operational aspects of the interactions of observers with physical systems.
Nevertheless, it may be possible to indirectly detect traces of nonlocality in
experiments where humans and other sentient subjects are involved


title: A biologically inspired model for transshipment problem

abstract:
  Transshipment problem is one of the basic operational research problems. In
this paper, our first work is to develop a biologically inspired mathematical
model for a dynamical system, which is first used to solve minimum cost flow
problem. It has lower computational complexity than Physarum Solver. Second, we
apply the proposed model to solve the traditional transshipment problem.
Compared with the conditional methods, experiment results show the provided
model is simple, effective as well as handling problem in a continuous manner.


title:
Current dependence of spin torque switching rate based on Fokker-Planck
  approach

abstract:
  The spin torque switching rate of an in-plane magnetized system in the
presence of an applied field is derived by solving the Fokker-Planck equation.
It is found that three scaling currents are necessary to describe the current
dependence of the switching rate in the low-current limit. The dependences of
these scaling currents on the applied field strength are also studied.


title: Reflection and implantation of low energy helium with tungsten surfaces

abstract:
  Reflection and implantation of low energy helium (He) ions by tungsten (W)
substrate are studied using molecular dynamics (MD) simulations. Motivated by
the ITER divertor design, our study considers a range of W substrate
temperatures (300 K, 1000 K, 1500 K), a range of He atom incidence energies
($\le$100 eV) and a range of angles of incidence ($0^{\circ}$-$75^{\circ}$)
with respect to substrate normal. The MD simulations quantify the reflection
and implantation function, the integrated moments such as the particle/energy
reflection coefficients and average implantation depths. Distributions of
implantation depths, reflected energy, polar and azimuthal angles of reflection
are obtained, as functions of simulation parameters, such as W substrate
temperature, polar angle of incidence, the energy of incident He, and the type
of W substrate surface. Comparison between the MD simulation results, the
results obtained using SRIM simulation package, and the existing experimental
and theoretical results is provided.


title: Variations on Memetic Algorithms for Graph Coloring Problems

abstract:
  Graph vertex coloring with a given number of colors is a well-known and
much-studied NP-complete problem.The most effective methods to solve this
problem are proved to be hybrid algorithms such as memetic algorithms or
quantum annealing. Those hybrid algorithms use a powerful local search inside a
population-based algorithm.This paper presents a new memetic algorithm based on
one of the most effective algorithms: the Hybrid Evolutionary Algorithm HEA
from Galinier and Hao (1999).The proposed algorithm, denoted HEAD - for HEA in
Duet - works with a population of only two individuals.Moreover, a new way of
managing diversity is brought by HEAD.These two main differences greatly
improve the results, both in terms of solution quality and computational
time.HEAD has produced several good results for the popular DIMACS benchmark
graphs, such as 222-colorings for \textless{}dsjc1000.9\textgreater{},
81-colorings for \textless{}flat1000\_76\_0\textgreater{} and even 47-colorings
for \textless{}dsjc500.5\textgreater{} and 82-colorings for
\textless{}dsjc1000.5\textgreater{}.


title: Foresighted Demand Side Management

abstract:
  We consider a smart grid with an independent system operator (ISO), and
distributed aggregators who have energy storage and purchase energy from the
ISO to serve its customers. All the entities in the system are foresighted:
each aggregator seeks to minimize its own long-term payments for energy
purchase and operational costs of energy storage by deciding how much energy to
buy from the ISO, and the ISO seeks to minimize the long-term total cost of the
system (e.g. energy generation costs and the aggregators' costs) by dispatching
the energy production among the generators. The decision making of the entities
is complicated for two reasons. First, the information is decentralized: the
ISO does not know the aggregators' states (i.e. their energy consumption
requests from customers and the amount of energy in their storage), and each
aggregator does not know the other aggregators' states or the ISO's state (i.e.
the energy generation costs and the status of the transmission lines). Second,
the coupling among the aggregators is unknown to them. Specifically, each
aggregator's energy purchase affects the price, and hence the payments of the
other aggregators. However, none of them knows how its decision influences the
price because the price is determined by the ISO based on its state. We propose
a design framework in which the ISO provides each aggregator with a conjectured
future price, and each aggregator distributively minimizes its own long-term
cost based on its conjectured price as well as its local information. The
proposed framework can achieve the social optimum despite being decentralized
and involving complex coupling among the various entities.


title: Monic representations of the Cuntz algebra and Markov measures

abstract:
  We study representations of the Cuntz algebras $\O_N$. While, for fixed $N$,
the set of equivalence classes of representations of $\O_N$ is known not to
have a Borel cross section, there are various subclasses of representations
which can be classified. We study monic representations of $\O_N$, that have a
cyclic vector for the canonical abelian subalgebra. We show that $\O_N$ has a
certain universal representation which contains all positive monic
representations. A large class of examples of monic representations is based on
Markov measures. We classify them and as a consequence we obtain that different
parameters yield mutually singular Markov measure, extending the classical
result of Kakutani. The monic representations based on the Kakutani measures
are exactly the ones that have a one-dimensional cyclic $S_i^*$-invariant
space.


title: A Busy Beaver Problem for Infinite-Time Turing Machines

abstract:
  This note introduces a generalization to the setting of infinite-time
computation of the busy beaver problem from classical computability theory, and
proves some results concerning the growth rate of an associated function. In
our view, these results indicate that the generalization is both natural and
promising.


title: Sparse recovery under weak moment assumptions

abstract:
  We prove that iid random vectors that satisfy a rather weak moment assumption
can be used as measurement vectors in Compressed Sensing, and the number of
measurements required for exact reconstruction is the same as the best possible
estimate -- exhibited by a random gaussian matrix. We also prove that this
moment condition is necessary, up to a $\log \log $ factor. Applications to the
Compatibility Condition and the Restricted Eigenvalue Condition in the noisy
setup and to properties of neighbourly random polytopes are also discussed.


title:
Modeling of $^6_\Lambda$He hypernucleus within configuration space
  Faddeev approach

abstract:
  The cluster $^4\rm He+\Lambda+\rm n$ model is applied to describe the
$^6_\Lambda$He hypernucleus. The consideration is based on the configuration
space Faddeev equations for a system of non-identical particles. A set of the
pair potentials includes the OBE simulating (NSC97f) model for the $\Lambda \rm
n$ interaction and the phenomenological potentials for the $\alpha\Lambda$ and
$\alpha \rm n$ interactions. We calculated energies of spin (1$^-$,2$^-$)
doublet. For the 2$^-$ excitation energy, the obtained value is 0.18 MeV. The
hyperon binding energy of the bound 1$^-$ state is less than the experimental
value, which may be an evidence for violation of the exact three-body cluster
structure.


title: On almost complex surfaces in the nearly K\"ahler $S^3\times S^3$

abstract:
  We study almost complex surfaces in the nearly K\"ahler $S^3\times S^3$. We
show that there is a local correspondence between almost complex surfaces and
solutions of the H-surface equation introduced by Wente. We find a global
holomorphic differential on every almost complex surface, and show that when
this differential vanishes, then the corresponding solution of the H-surface
equation gives a constant mean curvature surface in $\mathbb{R}^3$. We use
this, together with a theorem of Hopf, to classify all almost complex
2-spheres. In fact there is essentially only one, and it is totally geodesic.
More details, as well as the proofs of the various theorems are given in [1].
Finally, we state two theorems, one of which states that locally there are just
two almost complex surfaces with parallel second fundamental form.


title: Two-Atom Rydberg Blockade using Direct 6S to nP Excitation

abstract:
  We explore a single-photon approach to Rydberg state excitation and Rydberg
blockade. Using detailed theoretical models, we show the feasibility of direct
excitation, predict the effect of background electric fields, and calculate the
required interatomic distance to observe Rydberg blockade. We then measure and
control the electric field environment to enable coherent control of Rydberg
states. With this coherent control, we demonstrate Rydberg blockade of two
atoms separated by 6.6(3) {\mu}m. When compared with the more common two-photon
excitation method, this single-photon approach is advantageous because it
eliminates channels for decoherence through photon scattering and AC Stark
shifts from the intermediate state while moderately increasing Doppler
sensitivity.


title: Nakayama's Lemma on $\textbf{Act}-S$

abstract:
  A crucial lemma on module theory is Nakayama's lemma \cite{AF}. In this
article, we shall investigate some forms of Nakayama's lemma in the category of
right acts over a given monoid $S$ with identity 1. More precisely, among other
things, we show that equality $AI=A$ for some proper ideal $I$ of $S$ implies
$A=\{\theta\}$, when $A$ is a finitely generated quasi-strongly faithful
$S$-act with unique zero element $\theta$ and $S$ is a monoid in which its
unique maximal right ideal $\mathfrak{M}$ is two-sided. Furthermore, as an
application of Nakayama's lemma we prove Krull intersection theorem for
$S$-acts. Finally, as a consequence, we shall see a homological classification
form of this lemma, i.e, we prove if $S$ is a commutative monoid then every
projective $S$-act is free if and only if $E(S)=\{1\}$, which $E(S)$ is the set
of all idempotents of $S$.


title:
Analytic approximations, perturbation theory, effective field theory
  methods and their applications

abstract:
  We summarize the parallel session B4: 'Analytic approximations, perturbation
theory effective field theory methods and their applications' and the joint
session B2/B4: 'Approximate solutions to Einstein equations: Methods and
Applications', of the GR20 & Amaldi10 conference in Warsaw, July 2013. The
contributed talks reported significant advances on various areas of research in
gravity.


title: Hunting for binary Cepheids using lucky imaging technique

abstract:
  Detecting companions to Cepheids is difficult. In most cases the bright
pulsator overshines the fainter secondary. Since Cepheids play a key role in
determining the cosmic distance scale it is crucial to find binaries among the
calibrating stars of the period-luminosity relation. Here we present an ongoing
observing project of searching for faint and close companions of Galactic
Cepheids using lucky imaging technique.


title: A lower bound for metric 1-median selection

abstract:
  Consider the problem of finding a point in an n-point metric space with the
minimum average distance to all points. We show that this problem has no
deterministic $o(n^2)$-query $(4-\Omega(1))$-approximation algorithms.


title: A Graphical Approach to Radio Frequency Quadrupole Design

abstract:
  The design of a radio frequency quadrupole, an important section of all ion
accelerators, and the calculation of its beam dynamics properties can be
achieved using the existing computational tools. These programs, originally
designed in 1980s, show effects of aging in their user interfaces and in their
output. The authors believe there is room for improvement in both design
techniques using a graphical approach and in the amount of analytical
calculations before going into CPU burning finite element analysis techniques.
Additionally an emphasis on the graphical method of controlling the evolution
of the relevant parameters using the drag-to-change paradigm is bound to be
beneficial to the designer. A computer code, named DEMIRCI, has been written in
C++ to demonstrate these ideas. This tool has been used in the design of
Turkish Atomic Energy Authority (TAEK)'s 1.5 MeV proton beamline at Saraykoy
Nuclear Research and Training Center (SANAEM). DEMIRCI starts with a simple
analytical model, calculates the RFQ behavior and produces 3D design files that
can be fed to a milling machine. The paper discusses the experience gained
during design process of SANAEM Project Prometheus (SPP) RFQ and underlines
some of DEMIRCI's capabilities.


title: O(2) Hopf bifurcation of viscous shock waves in a channel

abstract:
  Extending work of Texier and Zumbrun in the semilinear non-re ection
symmetric case, we study O(2) transverse Hopf bifurcation, or \cellular
instability," of viscous shock waves in a channel, for a class of quasilinear
hyperbolic{parabolic systems including the equations of thermoviscoelasticity.
The main difficulties are to (i) obtain Fr'echet differentiability of the
time-T solution operator by appropriate hyperbolic{parabolic energy estimates,
and (ii) handle O(2) symmetry in the absence of either center manifold
reduction (due to lack of spectral gap) or (due to nonstandard quasilinear
hyperbolic-parabolic form) the requisite framework for treatment by spatial
dynamics on the space of time-periodic functions, the two standard treatments
for this problem. The latter issue is resolved by Lyapunov{Schmidt reduction of
the time-T map, yielding a four-dimensional problem with O(2) plus approximate
S1 symmetry, which we treat \by hand" using direct Implicit Function Theorem
arguments. The former is treated by balancing information obtained in
Lagrangian coordinates with that from an augmented system. Interestingly, this
argument does not apply to gas dynamics or magnetohydrodynamics (MHD), due to
the infinite-dimensional family of Lagrangian symmetries corresponding to
invariance under arbitrary volume-preserving diffeomorphisms.


title: Energy-aware Load Balancing Policies for the Cloud Ecosystem

abstract:
  The energy consumption of computer and communication systems does not scale
linearly with the workload. A system uses a significant amount of energy even
when idle or lightly loaded. A widely reported solution to resource management
in large data centers is to concentrate the load on a subset of servers and,
whenever possible, switch the rest of the servers to one of the possible sleep
states. We propose a reformulation of the traditional concept of load balancing
aiming to optimize the energy consumption of a large-scale system: {\it
distribute the workload evenly to the smallest set of servers operating at an
optimal energy level, while observing QoS constraints, such as the response
time.} Our model applies to clustered systems; the model also requires that the
demand for system resources to increase at a bounded rate in each reallocation
interval. In this paper we report the VM migration costs for application
scaling.


title: Will boson-sampling ever disprove the Extended Church-Turing thesis?

abstract:
  Boson-sampling is a highly simplified, but non-universal, approach to
implementing optical quantum computation. It was shown by Aaronson and Arkhipov
that this protocol cannot be efficiently classically simulated unless the
polynomial hierarchy collapses, which would be a shocking result in
computational complexity theory. Based on this, numerous authors have made the
claim that experimental boson-sampling would provide evidence against, or
disprove, the Extended Church-Turing thesis -- that any physically realisable
system can be efficiently simulated on a Turing machine. We argue against this
claim on the basis that, under a general, physically realistic independent
error model, boson-sampling does not implement a provably hard computational
problem in the asymptotic limit of large systems.


title: A scenario approach for non-convex control design

abstract:
  Randomized optimization is an established tool for control design with
modulated robustness. While for uncertain convex programs there exist
randomized approaches with efficient sampling, this is not the case for
non-convex problems. Approaches based on statistical learning theory are
applicable to non-convex problems, but they usually are conservative in terms
of performance and require high sample complexity to achieve the desired
probabilistic guarantees. In this paper, we derive a novel scenario approach
for a wide class of random non-convex programs, with a sample complexity
similar to that of uncertain convex programs and with probabilistic guarantees
that hold not only for the optimal solution of the scenario program, but for
all feasible solutions inside a set of a-priori chosen complexity. We also
address measure-theoretic issues for uncertain convex and non-convex programs.
Among the family of non-convex control- design problems that can be addressed
via randomization, we apply our scenario approach to randomized Model
Predictive Control for chance-constrained nonlinear control-affine systems.


title: Decompositions of Generalized Wavelet Representations

abstract:
  Let $N$ be a simply connected, connected nilpotent Lie group which admits a
uniform subgroup $\Gamma.$ Let $\alpha$ be an automorphism of $N$ defined by
$\alpha\left( \exp X\right) =\exp AX.$ We assume that the linear action of $A$
is diagonalizable and we do not assume that $N$ is commutative. Let $W$ be a
unitary wavelet representation of the semi-direct product group $\left\langle
\cup_{j\in\mathbb{Z}}\alpha^{j}\left( \Gamma\right) \right\rangle
\rtimes\left\langle \alpha\right\rangle $ defined by $W\left( \gamma,1\right)
=f\left( \gamma^{-1}x\right) $ and $W\left( 1,\alpha\right) =\left\vert \det
A\right\vert ^{1/2}f\left( \alpha x\right) .$ We obtain a decomposition of $W$
into a direct integral of unitary representations. Moreover, we provide an
explicit unitary operator intertwining the representations, a precise
description of the representations occurring, the measure used in the direct
integral decomposition and the support of the measure. We also study the
irreducibility of the fiber representations occurring in the direct integral
decomposition in various settings. We prove that in the case where $A$ is an
expansive automorphism then the decomposition of $W$ is in fact a direct
integral of unitary irreducible representations each occurring with infinite
multiplicities if and only if $N$ is non-commutative. This work naturally
extends results obtained by H. Lim, J. Packer and K. Taylor who obtained a
direct integral decomposition of $W$ in the case where $N$ is commutative and
the matrix $A$ is expansive, i.e. all eigenvalues have absolute values larger
than one.


title: The Tarski numbers of groups

abstract:
  The Tarski number of a non-amenable group G is the minimal number of pieces
in a paradoxical decomposition of G. In this paper we investigate how Tarski
numbers may change under various group-theoretic operations. Using these
estimates and known properties of Golod-Shafarevich groups, we show that the
Tarski numbers of 2-generated non-amenable groups can be arbitrarily large. We
also use the cost of group actions to show that there exist groups with Tarski
numbers 5 and 6. These provide the first examples of non-amenable groups
without free subgroups whose Tarski number has been computed precisely.


title: Asymptotically linear fractional Schrodinger equations

abstract:
  By exploiting a variational technique based upon projecting over the Pohozaev
manifold, we prove existence of positive solutions for a class of nonlinear
fractional Schrodinger equations having a nonhomogenous nonautonomous
asymptotically linear nonlinearity.


title: A Suggestion for MOND

abstract:
  Modified Newtonian dynamics (Mond) has had considerable success in describing
motions in galaxies. It uses a single force which falls off inversely with the
distance at large distances and inversely with the square of the distance at
smaller distances. We present an alternative theory with two forces, one the
traditional Newtonian inverse-square, and the other that falls off inversely
with distance at large distances. This obvious possibility has been avoided
because of fear that the second force would be incompatible with observed
planetary motions. However, the non-linear field equation that governs this
force is shown to reduce its strength near stars. The theory is derived from a
Lagrangian density with two scalar potentials. It is non-relativistic, but
nevertheless agrees with the classical tests of relativistic gravity and can be
used to calculate the bending of light in gravitational fields. Possible
applications to interactions in galactic clusters and to anomalous planetary
motions are noted.


title: Optimal Testing for Planted Satisfiability Problems

abstract:
  We study the problem of detecting planted solutions in a random
satisfiability formula. Adopting the formalism of hypothesis testing in
statistical analysis, we describe the minimax optimal rates of detection. Our
analysis relies on the study of the number of satisfying assignments, for which
we prove new results. We also address algorithmic issues, and give a
computationally efficient test with optimal statistical performance. This
result is compared to an average-case hypothesis on the hardness of refuting
satisfiability of random formulas.


title:
Using Light-Switching Molecules to Modulate Charge Mobility in a Quantum
  Dot Array

abstract:
  We have studied the electron hopping in a two-CdSe quantum dot system linked
by an azobenzene-derived light-switching molecule. This system can be
considered as a prototype of a QD supercrystal. Following the computational
strategies given in our recent work [Chu et al. J. Phys. Chem. C 115, 21409
(2011)], we have investigated the effects of molecular attachment, molecular
isomer (trans and cis) and QD size on electron hopping rate using Marcus
theory. Our results indicate that molecular attachment has a large impact on
the system for both isomers. In the most energetically favorable attachment,
the cis isomer provides significantly greater coupling between the two QDs and
hence the electron hopping rate is greater compared to the trans isomer. As a
result, the carrier mobility of the QD array in the low carrier density, weak
external electric field regime is several orders of magnitude higher in the cis
compared to the trans configuration. This is the first demonstration of
mobility modulation using QDs and azobenzene that could lead to a new type of
switching device.


title: 2d SCFT from M-branes and its spectral network

abstract:
  We consider the low-energy limit of the two-dimensional theory on multiple
M2-branes suspended between a flat M5-brane and a curved M5-brane. We argue
that it is described by an $\mathcal{N}=(2,2)$ supersymmetric Landau-Ginzburg
model with the superpotential determined by the shape of the curved M5-branes,
which flows in the low-energy limit to a Kazama-Suzuki coset model. We provide
evidence by studying ground states and BPS spectra of the systems.


title: Optical Biochemical Platforms for Nanoparticles Detection

abstract:
  In the biochemical sensing field, a fervent research activity related to the
development of real time, low cost, compact and high throughput devices for the
detection and characterization of natural or synthetic nanoparticles NPs
actually exists. In this research scenario, different platforms for biosensing
purposes have been developed according to the huge amount of physical effects
involved in the transduction of the biochemical-signal into a measurable output
signal. In the present work two different optical platforms for NP detection
have been investigated, one based on integrated optics and the other based on
microscopy. Both the approaches rely on the study of the interaction of an
electromagnetic wave with a small particle in the hypothesis of dealing with a
Rayleigh scatterer, i.e. a nanoparticle having a size really smaller than the
one of the wavelength of the incident light and scattering light elastically.


title:
Using the Buffer to Avoid Rebuffers: Evidence from a Large Video
  Streaming Service

abstract:
  To provide a better streaming experience, video clients today select their
video rates by observing and estimating the available capacity. Recent work has
shown that capacity estimation is fraught with difficulties because of complex
interactions between the ABR control loop, HTTP server performance and TCP
congestion control. Estimation-based rate selection algorithms can lead to
unnecessary rebuffering events and suboptimal video quality. This paper argues
that we should do away with estimating network capacity, and instead directly
observe and control the playback buffer--which is the state variable we are
most interested in controlling. We present a class of "buffer-based" rate
selection algorithms that reduce the rebuffering rate while allowing us to
control the delivered video quality. We implemented our algorithms inside the
Netflix video client and ran a series of experiments spanning millions of
Netflix users around the world. Our results show that by doing away with
estimating network capacity and instead focusing on buffer occupancy, we can
reduce rebuffer rates by 20% while holding video rate constant.


title:
Hypoellipticity of the $\bar\partial$-Neumann problem by means of
  subelliptic multipliers

abstract:
  We prove local hypoellipticity of the complex Laplacian $\Box$ and of the
Kohn Laplacian $\Box_b$ in a pseudoconvex boundary when, for a system of
cut-off $\eta$, the gradient $\partial_b\eta$ and the Levi form
$\partial_b\bar\partial_b\eta^2$ are subelliptic multipliers in the sense of
Kohn.


title: Possibilities of life around Alpha Centauri B

abstract:
  We make a preliminary assessment on the habitability of potential rocky
exoplanets around Alpha Centauri B. We use several indexes: the Earth
Similarity Index, a mathematical model for photosynthesis, and a biological
productivity model. Considering the atmospheres of the exoplanets similar to
current Earth's atmosphere, we find consistent predictions of both the Earth
Similarity Index and the biological productivity model. The mathematical model
for photosynthesis clearly failed because does not consider the temperature
explicitly. For the case of Alpha Centauri B, several simulation runs give 11
planets in the habitable zone. Applying to them above mentioned indexes, we
select the five exoplanets more prone for photosynthetic life; showing that two
of them in principle have better conditions than Earth for this kind of life.


title: Single to quadruple quantum dots with tunable tunnel couplings

abstract:
  We prepare a gate-defined quadruple quantum dot to study the gate-tunability
of single to quadruple quantum dots with finite inter-dot tunnel couplings. The
measured charging energies of various double dots suggest that the dot size is
governed by gate geometry. For the triple and quadruple dots we study
gate-tunable inter-dot tunnel couplings. Particularly for the triple dot we
find that the effective tunnel coupling between side dots significantly depends
on the alignment of the center dot potential. These results imply that the
present quadruple dot device has gate performance relevant for implementing
spin-based four-qubit systems with controllable exchange couplings.


title: Planar digraphs of digirth five are 2-colorable

abstract:
  Neumann-Lara (1985) and \v{S}krekovski conjectured that every planar digraph
with digirth at least three is 2-colorable. We prove a relaxed version of this
conjecture: every planar digraph of digirth at least five is 2-colorable. The
result also holds in the setting of list colorings.


title:
Observation of Energetic particles between a pair of Corotating
  Interaction Regions

abstract:
  We report observations of the acceleration and trapping of energetic ions and
electrons between a pair of corotating interaction regions (CIRs). The event
occurred in Carrington Rotation 2060. Observed at spacecraft STEREO-B, the two
CIRs were separated by less than 5 days. In contrast to other CIR events, the
fluxes of energetic ions and electrons in this event reached their maxima
between the trailing-edge of the first CIR and the leading edge of the second
CIR. The radial magnetic field (Br) reversed its sense and the anisotropy of
the flux also changed from sunward to anti-sunward between the two CIRs.
Furthermore, there was an extended period of counter-streaming suprathermal
electrons between the two CIRs. Similar observations for this event were also
obtained for ACE and STEREO-A. We conjecture that these observations were due
to a "U-shape" large scale magnetic field topology connecting the reverse shock
of the first CIR and the forward shock of the second CIR. Such a disconnected
U-shaped magnetic field topology may have formed due to magnetic reconnection
in the upper corona.


title: The group fixed by a family of endomorphisms of a surface group

abstract:
  For a closed surface $S$ with $\chi(S)<0$, we show that the fixed subgroup of
a family $\mathcal B$ of endomorphisms of $\pi_1(S)$ has $\rk \fix\mathcal
B\leq \rk \pi_1(S)$. In particular, if $\mathcal B$ contains a non-epimorphic
endomorphism, then $\rk \fix\mathcal B\leq \frac{1}{2} \rk \pi_1(S)$. We also
show that geometric subgroups of $\pi_1(S)$ are inert, and hence the fixed
subgroup of a family of epimorphisms of $\pi_1(S)$ is also inert.


title: Local matrix generalizations of $W$-algebras

abstract:
  In this paper, we propose local matrix generalizations of the classical
$W$-algebras based on the second Hamiltonian structure of the
$\mathcal{Z}_m$-valued KP hierarchy, where $\mathcal{Z}_m$ is a maximal
commutative subalgebra of $gl(m,\mathbb{C})$.


title: Cyclic Hodge Integrals and Loop Schur Functions

abstract:
  We conjecture an evaluation of three-partition cyclic Hodge integrals in
terms of loop Schur functions. Our formula implies the orbifold
Gromov-Witten/Donaldson-Thomas correspondence for toric Calabi-Yau threefolds
with transverse type A singularities. We prove the formula in the case where
one of the partitions is empty, and thus establish the orbifold Gromov-
Witten/Donaldson-Thomas correspondence for local toric surfaces with transverse
type A singularities.


title:
Direct comparison of graphene devices before and after transfer to
  different substrates

abstract:
  The entire graphene field-effect-transistor (FET) devices first fabricated on
SiO2/Si are peeled from the surface and placed on a different wafer. Both
longitudinal and transverse resistivity measurements of the devices before and
after the transfer are measured to calculate the mobility for a direct
comparison. After transferred to different SiO2/Si wafers, the mobility
generally is comparable and the defect density does not show any significant
increase, which indicates the degradation due to the transfer process itself is
minimal. The same method can be applied to transfer graphene devices to any
arbitrary substrates (e.g. SrTiO3 or STO). The transfer method developed here
not only eliminates the need to locate single-layer graphene on non-SiO2/Si
substrates for patterning, but also provides a convenient way to study the
effects of various substrates on graphene electronic properties.


title:
The Earliest Stages of Star and Planet Formation: Core Collapse, and the
  Formation of Disks and Outflows

abstract:
  (Abridged) In this review we focus on the observations and theory of the
formation of early disks and outflows, and their connections with the first
phases of planet formation. Large rotationally supported circumstellar disks,
although common around more evolved young stellar objects, are rarely detected
during the earliest, "Class 0" phase; however, a few excellent candidates have
been discovered recently around both low and high mass protostars. In this
early phase, prominent outflows are ubiquitously observed; they are expected to
be associated with at least small magnetized disks. Disk formation - once
thought to be a simple consequence of the conservation of angular momentum
during hydrodynamic core collapse - is far more subtle in magnetized gas. In
this case, the rotation can be strongly magnetically braked. Indeed, both
analytic arguments and numerical simulations have shown that disk formation is
suppressed in the strict ideal magnetohydrodynamic (MHD) limit for the observed
level of core magnetization. We review what is known about this "magnetic
braking catastrophe", possible ways to resolve it, and the current status of
early disk observations. Outflows are also intimately linked to disk formation;
they are a natural product of magnetic fields and rotation and are important
signposts of star formation. We review new developments on early outflow
generation since PPV. The properties of early disks and outflows are a key
component of planet formation in its early stages and we review these major
connections.


title:
Analog Network Coding for Multi-User Spread-Spectrum Communication
  Systems

abstract:
  This work presents another look at an analog network coding scheme for
multi-user spread-spectrum communication systems. Our proposed system combines
coding and cooperation between a relay and users to boost the throughput and to
exploit interference. To this end, each pair of users, $\mathcal{A}$ and
$\mathcal{B}$, that communicate with each other via a relay $\mathcal{R}$
shares the same spreading code. The relay has two roles, it synchronizes
network transmissions and it broadcasts the combined signals received from
users. From user $\mathcal{B}$'s point of view, the signal is decoded, and
then, the data transmitted by user $\mathcal{A}$ is recovered by subtracting
user $\mathcal{B}$'s own data. We derive the analytical performance of this
system for an additive white Gaussian noise channel with the presence of
multi-user interference, and we confirm its accuracy by simulation.


title:
X-Ray Absorption by the Warm-Hot Intergalactic Medium in the Hercules
  Supercluster

abstract:
  The "missing baryons", in the form of warm-hot intergalactic medium (WHIM),
are expected to reside in cosmic filamentary structures that can be traced by
signposts such as large-scale galaxy superstructures. The clear detection of an
X-ray absorption line in the Sculptor Wall demonstrated the success of using
galaxy superstructures as a signpost to search for the WHIM. Here we present an
XMM-Newton Reflection Grating Spectrometer (RGS) observation of the blazar Mkn
501, located in the Hercules Supercluster. We detected an O VII K$\alpha$
absorption line at the 98.7 % level ($2.5\sigma$) at the redshift of the
foreground Hercules Supercluster. The derived properties of the absorber are
consistent with theoretical expectations of the WHIM. We discuss the
implication of our detection for the search for the "missing baryons". While
this detection shows again that using signposts is a very effective strategy to
search for the WHIM, follow-up observations are crucial both to strengthen the
statistical significance of the detection and to rule out other
interpretations. A local, $z\sim0$ O VII K$\alpha$ absorption line was also
clearly detected at the $4\sigma$ level, and we discuss its implications for
our understanding of the hot gas content of our Galaxy.


title: Ferroelectric-like SrTiO3 surface dipoles probed by graphene

abstract:
  The electrical transport properties of graphene are greatly influenced by its
environment. Owing to its high dielectric constant, strontium titanate (STO) is
expected to suppress the long-range charged impurity scattering and
consequently to enhance the mobility. However, the absence of such enhancement
has caused some controversies regarding the scattering mechanism. In graphene
devices transferred from SiO2 to STO using a newly developed technique, we
observe a moderate mobility enhancement near the Dirac point, which is the
point of charge neutrality achieved by adjusting the Fermi level. While bulk
STO is not known as a ferroelectric material, its surface was previously
reported to exhibit an outward displacement of oxygen atoms and
ferroelectric-like dipole moment. When placed on STO, graphene shows strong and
asymmetric hysteresis in resistivity, which is consistent with the dipole
picture associated with the oxygen displacement. The hysteretic response of the
surface dipole moment diminishes the polarizability, therefore weakens the
ability of STO to screen the Coulomb potential of the impurities.


title: How accurate are SuperCOSMOS positions?

abstract:
  Optical positions from the SuperCOSMOS Sky Survey have been compared in
detail with accurate radio positions that define the second realisation of the
International Celestial Reference Frame (ICRF2). The comparison was limited to
the IIIaJ plates from the UK/AAO and Oschin (Palomar) Schmidt telescopes. A
total of 1373 ICRF2 sources was used, with the sample restricted to stellar
objects brighter than $B_J=20$ and Galactic latitudes $|b|>10^{\circ}$.
Position differences showed an rms scatter of $0.16''$ in right ascension and
declination. While overall systematic offsets were $<0.1''$ in each hemisphere,
both the systematics and scatter were greater in the north.


title:
A Comparative Study of Reservoir Computing for Temporal Signal
  Processing

abstract:
  Reservoir computing (RC) is a novel approach to time series prediction using
recurrent neural networks. In RC, an input signal perturbs the intrinsic
dynamics of a medium called a reservoir. A readout layer is then trained to
reconstruct a target output from the reservoir's state. The multitude of RC
architectures and evaluation metrics poses a challenge to both practitioners
and theorists who study the task-solving performance and computational power of
RC. In addition, in contrast to traditional computation models, the reservoir
is a dynamical system in which computation and memory are inseparable, and
therefore hard to analyze. Here, we compare echo state networks (ESN), a
popular RC architecture, with tapped-delay lines (DL) and nonlinear
autoregressive exogenous (NARX) networks, which we use to model systems with
limited computation and limited memory respectively. We compare the performance
of the three systems while computing three common benchmark time series:
H{\'e}non Map, NARMA10, and NARMA20. We find that the role of the reservoir in
the reservoir computing paradigm goes beyond providing a memory of the past
inputs. The DL and the NARX network have higher memorization capability, but
fall short of the generalization power of the ESN.


title: A combinatorial geometric Satake equivalence

abstract:
  The geometric Satake correspondence provides an equivalence of categories
between the Satake category of spherical perverse sheaves on the affine
Grassmannian and the category of representations of the dual group. In this
note, we define a combinatorial version of the Satake category using
irreducible components of fibres of the convolution morphism. We then prove an
equivalence of coboundary categories between this combinatorial Satake category
and the category of crystals of the dual group.


title:
Lagrangian perturbations theory : Third-order solution for general dark
  energy models

abstract:
  We investigate the Lagrangian perturbation theory of a general dark energy
models with a constant equation of state, \omega, and derive the fitting form
of the fastest growing mode solutions up to the third order. These fitting
forms are less than few % errors compared to the numerical calculation. We also
correct the solutions of Einstein-de Sitter and the open universe with the
proper initial conditions and the correct consideration for the growing mode
solutions in order to compare with the general dark energy models. Even though
these fitting forms are limited to the constant equation of state models, one
can apply these to the time-varying \omega by interpolating between models with
the constant \omega. These fitting forms can be used for the correct prediction
for the two point correlation function and can give the proper predictions for
the different dark energy models.


title:
Lower bounds for algebraic connectivity of graphs in terms of matching
  number or edge covering number

abstract:
  In this paper we characterize the unique graph whose algebraic connectivity
is minimum among all connected graphs with given order and fixed matching
number or edge covering number, and present two lower bounds for the algebraic
connectivity in terms of the matching number or edge covering number.


title:
Multistage Compute-and-Forward with Multilevel Lattice Codes Based on
  Product Constructions

abstract:
  A novel construction of lattices is proposed. This construction can be
thought of as Construction A with codes that can be represented as the
Cartesian product of $L$ linear codes over
$\mathbb{F}_{p_1},\ldots,\mathbb{F}_{p_L}$, respectively; hence, is referred to
as the product construction. The existence of a sequence of such lattices that
are good for quantization and Poltyrev-good under multistage decoding is shown.
This family of lattices is then used to generate a sequence of nested lattice
codes which allows one to achieve the same computation rate of Nazer and
Gastpar for compute-and-forward under multistage decoding, which is referred to
as lattice-based multistage compute-and-forward.
  Motivated by the proposed lattice codes, two families of signal
constellations are then proposed for the separation-based compute-and-forward
framework proposed by Tunali \textit{et al.} together with a multilevel
coding/multistage decoding scheme tailored specifically for these
constellations. This scheme is termed separation-based multistage
compute-and-forward and is shown having a complexity of the channel coding
dominated by the greatest common divisor of the constellation size (may not be
a prime number) instead of the constellation size itself.


title: A Survey on optimization approaches to text document clustering

abstract:
  Text Document Clustering is one of the fastest growing research areas because
of availability of huge amount of information in an electronic form. There are
several number of techniques launched for clustering documents in such a way
that documents within a cluster have high intra-similarity and low
inter-similarity to other clusters. Many document clustering algorithms provide
localized search in effectively navigating, summarizing, and organizing
information. A global optimal solution can be obtained by applying high-speed
and high-quality optimization algorithms. The optimization technique performs a
globalized search in the entire solution space. In this paper, a brief survey
on optimization approaches to text document clustering is turned out.


title: An ANN Based Call Handoff Management Scheme for Mobile Cellular Network

abstract:
  Handoff decisions are usually signal strength based because of simplicity and
effectiveness. Apart from the conventional techniques, such as threshold and
hysteresis based schemes, recently many artificial intelligent techniques such
as Fuzzy Logic, Artificial Neural Network (ANN) etc. are also used for taking
handoff decision. In this paper, an Artificial Neural Network based handoff
algorithm is proposed and its performance is studied. We have used ANN here for
taking fast and accurate handoff decision. In our proposed handoff algorithm,
Backpropagation Neural Network model is used.The advantages of Back propagation
method are its simplicity and reasonable speed. The algorithm is designed,
tested and found to give optimum results.


title:
Bidirectional Control of Absence Seizures by the Basal Ganglia: A
  Computational Evidence

abstract:
  Absence epilepsy is believed to be associated with the abnormal interactions
between the cerebral cortex and thalamus. Besides the direct coupling,
anatomical evidence indicates that the cerebral cortex and thalamus also
communicate indirectly through an important intermediate bridge--basal ganglia.
It has been thus postulated that the basal ganglia might play key roles in the
modulation of absence seizures, but the relevant biophysical mechanisms are
still not completely established. Using a biophysically based model, we
demonstrate here that the typical absence seizure activities can be controlled
and modulated by the direct GABAergic projections from the substantia nigra
pars reticulata (SNr) to either the thalamic reticular nucleus (TRN) or the
specific relay nuclei (SRN) of thalamus, through different biophysical
mechanisms. Under certain conditions, these two types of seizure control are
observed to coexist in the same network. More importantly, due to the
competition between the inhibitory SNr-TRN and SNr-SRN pathways, we find that
both decreasing and increasing the activation of SNr neurons from the normal
level may considerably suppress the generation of SWDs in the coexistence
region. Overall, these results highlight the bidirectional functional roles of
basal ganglia in controlling and modulating absence seizures, and might provide
novel insights into the therapeutic treatments of this brain disorder.