title:
Introduction to Sofic and Hyperlinear groups and Connes' embedding
  conjecture

abstract:
  Sofic and hyperlinear groups are the countable discrete groups that can be
approximated in a suitable sense by finite symmetric groups and groups of
unitary matrices. These notions turned out to be very deep and fruitful, and
stimulated in the last 15 years an impressive amount of research touching
several seemingly distant areas of mathematics including geometric group
theory, operator algebras, dynamical systems, graph theory, and more recently
even quantum information theory. Several longstanding conjectures that are
still open for arbitrary groups were settled in the case of sofic or
hyperlinear groups. These achievements aroused the interest of an increasing
number of researchers into some fundamental questions about the nature of these
approximation properties. Many of such problems are to this day still open such
as, outstandingly: Is there any countable discrete group that is not sofic or
hyperlinear? A similar pattern can be found in the study of II_1 factors. In
this case the famous conjecture due to Connes (commonly known as the Connes
embedding conjecture) that any II_1 factor can be approximated in a suitable
sense by matrix algebras inspired several breakthroughs in the understanding of
II_1 factors, and stands out today as one of the major open problems in the
field. The aim of these notes is to present in a uniform and accessible way
some cornerstone results in the study of sofic and hyperlinear groups and the
Connes embedding conjecture. The presentation is nonetheless self contained and
accessible to any student or researcher with a graduate level mathematical
background. An appendix by V. Pestov provides a pedagogically new introduction
to the concepts of ultrafilters, ultralimits, and ultraproducts for those
mathematicians who are not familiar with them, and aiming to make these
concepts appear very natural.


title: Asymptotic stability for the Couette flow in the 2D Euler equations

abstract:
  In this expository note we discuss our recent work [arXiv:1306.5028] on the
nonlinear asymptotic stability of shear flows in the 2D Euler equations of
ideal, incompressible flow. In that work it is proved that perturbations to the
Couette flow which are small in a suitable regularity class converge strongly
in $L^2$ to a shear flow which is close to the Couette flow. Enstrophy is mixed
to small scales by an almost linear evolution and is generally lost in the weak
limit as t -> +/- infinity. In this note we discuss the most important physical
and mathematical aspects of the result and the key ideas of the proof.


title:
The geometry of the tangent bundle and the relativistic kinetic theory
  of gases

abstract:
  This article discusses the relativistic kinetic theory for a simple
collisionless gas from a geometric perspective. We start by reviewing the rich
geometrical structure of the tangent bundle TM of a given spacetime manifold,
including the splitting of the tangent spaces of TM into horizontal and
vertical subspaces and the natural metric and symplectic structure it induces
on TM. Based on these structures we introduce the Liouville vector field L and
a suitable Hamiltonian function H on TM. The Liouville vector field turns out
to be the Hamiltonian vector field associated to H. On the other hand, H also
defines the mass shells as Lorentzian submanifolds of the tangent bundle. A
simple collisionless gas is described by a distribution function on a
particular mass shell, satisfying the Liouville equation. Together with the
Liouville vector field the distribution function can be thought of as defining
a fictitious incompressible fluid on the mass shells, with associated conserved
current density. Flux integrals of this current density provide the averaged
properties of the gas, while suitable fibre integrals of the distribution
function define divergence-free tensor fields on the spacetime manifold such as
the current density and stress-energy tensor. Finally, we discuss the
relationship between symmetries of the spacetime manifold and symmetries of the
distribution function.
  As a first application of our formalism we derive the most general
spherically symmetric distribution function on any spherically symmetric
spacetime and write the Einstein-Liouville equations as effective field
equations on the two-dimensional radial manifold. As a second application we
derive the most general collisionless distribution function on a Kerr black
hole spacetime background.


title:
Ferromagnetic cluster-glass state in itinerant electron system
  Sr1-xLaxRuO3

abstract:
  The magnetic and electronic properties of Sr1-xLaxRuO3 were studied by means
of dc-magnetization, ac-susceptibility, specific heat, and electrical
resistivity measurements. The dc-magnetization and ac-susceptibility
measurements have revealed that the transition temperature and the ordered
moment of the ferromagnetic order are strongly suppressed as La is substituted
for Sr. The ac-susceptibility exhibits a peak at T* due to the occurrence of
spontaneous spin polarization. Furthermore, we observed that T* shows clear
frequency variations for x>= 0.3. The magnitude of the frequency shifts of T*
is comparable to that of cluster-glass systems, and the frequency dependence is
well described in terms of the Vogel-Fulcher law. On the other hand, it is
found that the linear specific heat coefficient gamma enhances with the
suppression of the ferromagnetic order. The relatively large gamma values
reflect the presence of the Ru 4d state at Fermi level, and hence, the
magnetism of this system is considered to be tightly coupled with the itinerant
characteristics of the Ru 4d electrons. The present experimental results and
analyses suggest that the intrinsic coexistence of the spatially inhomogeneous
magnetic state and the itinerant nature of the Ru 4d electrons is realized in
this system, and such a feature may be commonly involved in La- and Ca-doped
SrRuO3.


title: Submodular Maximization Meets Streaming: Matchings, Matroids, and More

abstract:
  We study the problem of finding a maximum matching in a graph given by an
input stream listing its edges in some arbitrary order, where the quantity to
be maximized is given by a monotone submodular function on subsets of edges.
This problem, which we call maximum submodular-function matching (MSM), is a
natural generalization of maximum weight matching (MWM), which is in turn a
generalization of maximum cardinality matching (MCM). We give two incomparable
algorithms for this problem with space usage falling in the semi-streaming
range---they store only $O(n)$ edges, using $O(n\log n)$ working memory---that
achieve approximation ratios of $7.75$ in a single pass and $(3+\epsilon)$ in
$O(\epsilon^{-3})$ passes respectively. The operations of these algorithms
mimic those of Zelke's and McGregor's respective algorithms for MWM; the
novelty lies in the analysis for the MSM setting. In fact we identify a general
framework for MWM algorithms that allows this kind of adaptation to the broader
setting of MSM.
  In the sequel, we give generalizations of these results where the
maximization is over "independent sets" in a very general sense. This
generalization captures hypermatchings in hypergraphs as well as independence
in the intersection of multiple matroids.


title: Precision bounds for noisy nonlinear quantum metrology

abstract:
  We derive the ultimate bounds on the performance of nonlinear measurement
schemes in the presence of noise. In particular, we investigate the precision
of the second-order estimation scheme in the presence of the two most
detrimental types of noise, photon loss and phase diffusion. We find that the
second-order estimation scheme is affected by both types of noise in an
analogous way as the linear one. Moreover, we observe that for both types of
noise the gain in the phase sensitivity with respect to the linear estimation
scheme is given by a multiplicative term $\mathcal{O}(1/N)$. Interestingly, we
also find that under certain circumstances, a careful engineering of the
environment can, in principle, improve the performance of measurement schemes
affected by phase diffusion.


title: Neutral kaon mixing from new physics: matrix elements in $N_f=2+1$ QCD

abstract:
  We present results for matrix elements of $\Delta S=2$ four-fermion operators
arising generically in models of new physics. These are needed to constrain
such models using the measured values of $\varepsilon_K$ and $\Delta M_K$. We
use lattice QCD with 2+1 flavors of improved staggered fermions on lattices
generated by the MILC collaboration. We extrapolate to the continuum from three
lattice spacings ranging down to $a\approx 0.045\;$fm. Total errors are $\sim
5-6%$, arising primarily from our use of one-loop matching between lattice and
continuum operators. For two of the matrix elements, our results disagree
significantly from those obtained using different fermion discretizations.


title: Continuous maximal regularity on uniformly regular Riemannian manifolds

abstract:
  We establish continuous maximal regularity results for parabolic differential
operators acting on sections of tensor bundles on Riemannian manifolds. As an
application, we show that solutions to the Yamabe flow instantaneously
regularize and become real analytic in space and time. The regularity result is
obtained by introducing a family of parameter-dependent diffeomorphims acting
on functions over Riemannian manifolds in conjunction with maximal regularity
and the implicit function theorem.


title: A tale of ellipsoids in potential theory

abstract:
  Ellipsoids possess several beautiful properties associated with classical
potential theory. Some of them are well known, and some have been forgotten. In
this article we hope to bring a few of the "lost" pieces of classical
mathematics back to the limelight.


title:
A family of parameter-dependent diffeomorphisms acting on function
  spaces over a Riemannian manifold and applications to geometric flows

abstract:
  It is the purpose of this article to establish a technical tool to study
regularity of solutions to parabolic equations on manifolds. As applications of
this technique, we prove that solutions to the Ricci-DeTurck flow, the surface
diffusion flow and the mean curvature flow enjoy joint analyticity in time and
space, and solutions to the Ricci flow admit temporal analyticity.


title: The limit on $w'$ for tachyon dark energy

abstract:
  We get the same degeneracy relation between $w_0$ and $w_a$ for the tachyon
fields as for quintessence and phantom fields. Our results show that the
dynamics of scalar fields with different origins becomes indistinguishable when
the equation of state parameter $w$ does not deviate too far away from -1, and
the time variation $w'$ satisfies the same bound for the same class of models.
For the tachyon fields, a limit on $w'$ exists due to the Hubble damping and we
derived the generic bounds on $w'$ for different classes of models. We may
distinguish different models in the phase plane of $w-w'$. The current
constraints on $w$ and $w'$ are consistent with all classes of models. We need
to improve the constraint on $w'$ by 50% to distinguish different models.


title: First measurement of gravitational lensing by cosmic voids in SDSS

abstract:
  We report the first measurement of the diminutive lensing signal arising from
matter underdensities associated with cosmic voids. While undetectable
individually, by stacking the weak gravitational shear estimates around 901
voids detected in SDSS DR7 by Sutter et al. (2012a), we find substantial
evidence for a depression of the lensing signal compared to the cosmic mean.
This depression is most pronounced at the void radius, in agreement with
analytical models of void matter profiles. Even with the largest void sample
and imaging survey available today, we cannot put useful constraints on the
radial dark-matter void profile. We invite independent investigations of our
findings by releasing data and analysis code to the public at
https://github.com/pmelchior/void-lensing


title: Obscuration of Flare Emission by an Eruptive Prominence

abstract:
  We report on the eclipsing of microwave flare emission by an eruptive
prominence from a neighboring region as observed by the Nobeyama
Radioheliograph at 17 GHz. The obscuration of the flare emission appears as a
dimming feature in the microwave flare light curve. We use the dimming feature
to derive the temperature of the prominence and the distribution of heating
along the length of the filament. We find that the prominence is heated to a
temperature above the quiet Sun temperature at 17 GHz. The duration of the
dimming is the time taken by the eruptive prominence in passing over the
flaring region. We also find evidence for the obscuration in EUV images
obtained by the Solar and Heliospheric Observatory (SOHO) mission.


title:
Uniqueness of maximum three-distance sets in the three-dimensional
  Euclidean space

abstract:
  A subset $X$ in the $d$-dimensional Euclidean space is called a $k$-distance
set if there are exactly $k$ distances between two distinct points in $X$.
Einhorn and Schoenberg conjectured that the vertices of the regular icosahedron
is the only 12-point three-distance set in $\mathbb{R}^3$ up to isomorphism. In
this paper, we prove the uniqueness of 12-point three-distance sets in
$\mathbb{R}^3$.


title:
Timelike vs spacelike DVCS from JLab, Compass to ultraperipheral
  collisions and AFTER@LHC

abstract:
  Timelike and spacelike virtual Compton scattering in the generalized Bjorken
scaling regime are complementary tools to access generalized parton
distributions. We stress that the gluonic contributions are by no means
negligible, even in the medium energy range which will be studied intensely at
JLab12 and in the COMPASS-II experiment at CERN. Ultraperipheral collisions
with proton or ion beams may also be used at RHIC and at collider or fixed
target experiments at LHC.


title: Isovector and hidden-beauty partners of the X(3872)

abstract:
  The isovector partners of the X(3872), recently found at BES III, Belle and
CLEO-c were predicted in a simple model based on the chromomagnetic interaction
among quarks (H. Hogaasen, J-M. Richard and P. Sorba, Phys. Rev. D73, 054013,
2006). The extension to the hidden-beauty sector is discussed.


title: Duality and Socle Generators for Residual Intersections

abstract:
  Paper has been accepted for publication in the Journal f\"ur die reine und
Angewandte Mathematik. This version contains the corrections and additional
references made in the Galley proofs.


title:
Creation of planar charged fermions in Coulomb and Aharonov-Bohm
  potentials

abstract:
  The creation of charged fermions from the vacuum by a Coulomb field in the
presence of an Aharonov--Bohm (AB) potential are studied in 2+1 dimensions. The
process is governed by a (singular) Dirac Hamiltonian that requires the
supplementary definition in order for it to be treated as a self-adjoint
quantum-mechanical operator. By constructing a one-parameter self-adjoint
extension of the Dirac Hamiltonian, specified by boundary conditions, we
describe the (virtual bound) quasistationary states with "complex energy"
emerging in an attractive Coulomb potential, derive for the first time, complex
equations (depending upon the electron spin and the extension parameter) for
the quasistationary state "complex energy". The constructed self-adjoint Dirac
Hamiltonians in Coulomb and AB potentials are applied to provide a correct
description to the low-energy electron excitations, as well as the creation of
charged quasiparticles from the vacuum in graphene by the Coulomb impurity in
the presence of AB potential. It is shown that the strong Coulomb field can
create charged fermions for some range of the extension parameter.


title: On the Strategic Allocation of Social Gratification

abstract:
  Members of social networks are given opportunities to bestow positive
recognition upon one another by means of constructs such as "likes" and
"retweets." Although recipients no doubt experience utility from these actions,
one might question why these constructs with no intrinsic value for the sender
are exchanged at all. Here we formulate a metric for the prestige of a member
of a social network based on his or her place within the network and the rate
at which "likes" are exchanged within his or her social circle. Simulation
reveals that the 1% most strategically-optimized networks exchange likes at an
average rate 23.5% higher than that of their random counterparts. This suggests
that purely strategic agents, even with no concern for altruism or the general
welfare, experience utility from giving social gratification. Further, we show
that prestige-maximization creates a selective pressure for structural features
associated with social networks including clustering and the small-world
property.


title: On three theorems of Folsom, Ono and Rhoades

abstract:
  In his deathbed letter to Hardy, Ramanujan gave a vague definition of a mock
modular function: at each root of unity its asymptotics matches the one of a
modular form, though a choice of the modular function depends on the root of
unity. Recently Folsom, Ono and Rhoades have proved an elegant result about the
match for a general family related to Dyson's rank (mock theta) function and
the Andrews--Garvan crank (modular) function---the match with explicit formulae
for implied $O(1)$ constants. In this note we give another elementary proof of
Ramanujan's original claim and outline some heuristics which may be useful for
obtaining a new proof of the general Folsom--Ono--Rhoades theorem.


title: Generalised Planar Black Holes and the Holography of Hydrodynamic Shear

abstract:
  AdS black holes with planar event horizon topology play a central role in
AdS/CFT holography, and particularly in its applications. Generalisations of
the known planar black holes can be found by considering the
Plebanski--Demianski metrics, a very general family of exactly specified
solutions of the Einstein equations. These generalised planar black holes may
be useful in applications. We give a concrete example of this in the context of
the holographic description of the Quark-Gluon Plasma (QGP). We argue that our
generalised planar black holes allow us to construct a model of the internal
shearing motion generated when the QGP is produced in peripheral heavy-ion
collisions. When embedded in string theory, the bulk physics is in fact
unstable. We find however that this instability may develop too slowly to
affect the evolution of the plasma, except possibly for high values of the
quark chemical potential, such as will be studied in experimental scans of the
quark matter phase diagram.


title: Beyond visual P300 based brain-computer interfacing paradigms

abstract:
  The paper reviews and summarizes recent developments in spatial auditory and
tactile brain-computer interfacing neurotechology applications. It serves as
the latest developments summary in "non-visual" brain-computer interfacing
solutions presented in a tutorial delivered by the author at the IICST 2013
workshop. The novel concepts of unimodal auditory or tactile, as well as a
bimodal combined paradigms are described and supported with recent research
results from our BCI-lab research group at Life Science Center, University of
Tsukuba, Japan. The newly developed experimental paradigms fit perfectly to
needs of paralyzed or hearing impaired users, in case of tactile stimulus, as
well as for able users who cannot utilize vision in computer or machine
interaction (driving or operation of machinery required not disturbed
eyesight). We present and review the EEG event related potential responses
useful for brain computer interfacing applications beyond state-of-the-art
visual paradigms. In conclusion the recent results are discussed and
suggestions for further applications are drawn.


title: Topological properties in topological insulators and superconductors

abstract:
  We give a self-contained and enriched review about topology properties in the
rapidly growing field of topological states of matter (TSM). This review is
mainly focus on the beautiful interplay of topology mathematics and condensed
matter physics that issuing TSM. Fiber bundle theory is a powerful concept to
describe the non-trivial topology properties underlying the physical system. So
we briefly present some motivation of fiber bundle theory and following that
several effective topological methods have been introduced to judge whether a
fiber bundle is trivial or not. Next, we give some topological invariants that
characterizes the non-trivial TSM in the non-interacting systems in all
dimensions, which is called topological band theory. Following that, we review
and generalize the topological response using topological field theory called
Chern-Simons effective theory.
  Finally, the classification of free-fermion systems have been studied by loop
space and K-theory.


title: Single image super resolution in spatial and wavelet domain

abstract:
  Recently single image super resolution is very important research area to
generate high resolution image from given low resolution image. Algorithms of
single image resolution are mainly based on wavelet domain and spatial domain.
Filters support to model the regularity of natural images is exploited in
wavelet domain while edges of images get sharp during up sampling in spatial
domain. Here single image super resolution algorithm is presented which based
on both spatial and wavelet domain and take the advantage of both. Algorithm is
iterative and use back projection to minimize reconstruction error. Wavelet
based denoising method is also introduced to remove noise.


title:
Wormholes in higher dimensional space-time: Exact solutions and their
  linear stability analysis

abstract:
  We derive the simplest traversable wormhole solutions in $n$-dimensional
general relativity, assuming static and spherically symmetric spacetime with a
ghost scalar field. This is the generalization of the Ellis solution (or the
so-called Morris-Thorne's traversable wormhole) into a higher-dimension. We
also study their stability using linear perturbation analysis. We obtain the
master equation for the perturbed gauge-invariant variable and search their
eigenvalues. Our analysis shows that all higher-dimensional wormholes have an
unstable mode against the perturbations with which the throat radius is
changed. The instability is consistent with the earlier numerical analysis in
four-dimensional solution.


title:
Quantum Field Theory Analysis of Polarizations Correlations,
  Entanglement and Bell's Inequality: Explicit Processes

abstract:
  This paper provides explicit and detailed quantum field theory (QFT)
computations of polarizations correlations of emerging particles in several
processes in QED, Electroweak Theory, and even in particle productions from
strings, and hence are based on dynamical theries. The novel properties
observed in the computations of such polarizations correlations, as predicted
by QFT, is that they depend on the speed of the colliding particles, and, in
some cases, even on coupling parameters ratios as well as on mass ratios of the
underlying theory. These investigations clearly show that arguments based
simply on combining spins to generate probabilities of such polarization
correlations are not reliable. The novel properties obtained, with details of
derivations provided here, hopefully would call for experiments on
polarizations correlations which would monitor speeds of colliding particles,
and, would, in turn, lead to new tests of the fundamental interactions of QFT
such as of QED and of the Electroweak Theory.


title:
Hamilton-Jacobi method for molecular distribution function in a chemical
  oscillator

abstract:
  Using the Hamilton-Jacobi method, we solve chemical Fokker-Planck equations
within the Gaussian approximation and obtain a simple and compact formula for a
conditional probability distribution. The formula holds in general transient
situations, and can be applied not only for a steady state but also for a
oscillatory state. By analyzing the long time behavior of the solution in the
oscillatory case, we obtain the phase diffusion constant along the periodic
orbit and the steady distribution perpendicular to it. A simple method for
numerical evaluation of these formulas are devised, and they are compared with
Monte Carlo simulations in the case of Brusselator as an example. Some results
are shown to be identical to previously obtained expressions.


title: One-dimensional superlattices with s-p resonance

abstract:
  We propose a realization of an extended Bose-Hubbard model, which takes into
account next-nearest-neighbor tunneling, by one-dimensional double-well optical
superlattice with a resonance between s and p orbitals in the neighboring
sites. Custom method of finding maximally-localized Wannier functions enables
us to compute physical tunneling coefficients, which put some restrictions on
the studies of the model, what have recently been done using arbitrary values
of parameters. Furthermore, it turns out that out of s-p resonance the system
splits up into two disconnected lattices. We analyze also Zak-Berry phase and
single-particle spectrum of the system. In order to present the problem in the
full context, short review of rudiments of optical lattice physics and
derivation of the standard Bose-Hubbard model is included.


title:
Injection of thermal and suprathermal seed particles into coronal shocks
  of varying obliquity

abstract:
  Context: Diffusive shock acceleration in the solar corona can accelerate
solar energetic particles to very high energies. Acceleration efficiency is
increased by entrapment through self-generated waves, which is highly dependent
on the amount of accelerated particles. This, in turn, is determined by the
efficiency of particle injection into the acceleration process.
  Aims: We present an analysis of the injection efficiency at coronal shocks of
varying obliquity. We assessed injection through reflection and downstream
scattering, including the effect of a cross-shock potential. Both quasi-thermal
and suprathermal seed populations were analysed. We present results on the
effect of cross-field diffusion downstream of the shock on the injection
efficiency.
  Methods: Using analytical methods, we present applicable injection speed
thresholds that were compared with both semi-analytical flux integration and
Monte Carlo simulations, which do not resort to binary thresholds. Shock-normal
angle and shock-normal velocity were varied to assess the injection efficiency
with respect to these parameters.
  Results: We present evidence of a significant bias of thermal seed particle
injection at small shock-normal angles. We show that downstream isotropisation
methods affect the theta-dependence of this result. We show a non-negligible
effect caused by the cross-shock potential, and that the effect of downstream
cross-field diffusion is highly dependent on boundary definitions.
  Conclusions: Our results show that for Monte Carlo simulations of coronal
shock acceleration a full distribution function assessment with downstream
isotropisation through scatterings is necessary to realistically model particle
injection. Based on our results, seed particle injection at quasi-parallel
coronal shocks can result in significant acceleration efficiency, especially
when combined with varying field-line geometry.


title:
Study of baryon octet electromagnetic form factors in perturbative
  chiral quark model

abstract:
  The electromagnetic properties of baryon octet are studied in the
perturbative chiral quark model (PCQM). The relativistic quark wave function is
extracted by fitting the theoretical results of the proton charge form factor
to experimental data and the predetermined quark wave function is applied to
study the electromagnetic form factors of other octet baryons as well as
magnetic moments, charge and magnetic radii. The PCQM results are found, based
on the predetermined quark wave function, in good agreement with experimental
data.


title:
The quantum and Klein-Gordon oscillators in a non-commutative complex
  space and the thermodynamic functions

abstract:
  In this work we study the quantum and Klein-Gordon oscillators in
non-commutative complex space. We show that the quantum oscillator in
non-commutative complex space obeys an equation similar to the equation of
motion of an electron with spin in a commutative space in an external uniform
magnetic field. Therefore the wave function ${\psi}(z,\bar{z}) $ takes values
in $C^{4}$, spin up, spin down, particle, antiparticle, a result which is
obtained by the Dirac theory. We derive the thermodynamic functions associated
to the partition function. We show that the non-commutativity affects energy at
the high temperature limit. The Klein Gordon oscillator in non-commutative
complex space also has a similar equation of motion to that a fermions with
spin 1/2 in a commutative space in a constant magnetic field. The energy levels
could be obtained by exact solution.


title:
Koecher-Maass series of a certain half-integral weight modular form
  related to the Duke-Imamoglu-Ikeda lift

abstract:
  Let k and n be positive even integers. For a cuspidal Hecke eigenform h in
the Kohnen plus space of weight k-n/2+1/2, let f be the corresponding primitive
form of weight 2k-n for SL(2,Z) under the Shimura correspondence, and I(h) the
Duke-Imamoglu-Ikeda lift of h to the space of cusp forms of weight k of genus
n. Moreover, let FJ(I(h),1) be the first Fourier-Jacobi coefficient of I(h) and
s(FJ(I(h),1)) be the cusp form in the generalized Kohnen plus space of weight
k-1/2 corresponding to FJ(I(h),1) under the Ibukiyama isomorphism. We then give
an explicit formula for the Koecher-Maass series of s(FJ(I(h),1)) expressed in
terms of the usual L-functions of h and f.


title: Strain-induced magnetism in MoS2 monolayer with defects

abstract:
  The strain-induced magnetism is observed in single-layer MoS2 with atomic
single vacancies from density functional calculations. Calculated magnetic
moment is no less than 2muB per vacancy defect. The straininduced band gap
closure is concurrent with the occurrence of the magnetism. Possible physical
mechanism of the emergence of strain-induced magnetism is illustrated. We also
demonstrate the possibility to test the predicted magnetism in experiment. Our
study may provide an opportunity for the design of new type of memory-switching
or logic devices by using earth-rich nonmagnetic materials MoS2.


title: A first evidence of the CMSSM is appearing soon

abstract:
  We explore the coannihilation region of the constrained minimal
supersymmetric standard model (CMSSM) being consistent with current
experimental/observational results. The requirements from the
experimental/observational results are the 125GeV Higgs mass and the relic
abundances of both the dark matter and light elements, especially the
lithium-7. We put these requirements on the caluculated values, and thus we
obtain allowed region. Then we give predictions to the mass spectra of the SUSY
particles, the anomalous magnetic moment of muon, branching fractions of the
B-meson rare decays, the direct detection of the neutralino dark matter, and
the number of SUSY particles produced in 14TeV run at the LHC experiment.
Comparing these predictions with current bounds, we show the feasibility of the
test for this scenario in near future experiment.


title:
Modified Cross-Validation for Penalized High-Dimensional Linear
  Regression Models

abstract:
  In this paper, for Lasso penalized linear regression models in
high-dimensional settings, we propose a modified cross-validation method for
selecting the penalty parameter. The methodology is extended to other
penalties, such as Elastic Net. We conduct extensive simulation studies and
real data analysis to compare the performance of the modified cross-validation
method with other methods. It is shown that the popular $K$-fold
cross-validation method includes many noise variables in the selected model,
while the modified cross-validation works well in a wide range of coefficient
and correlation settings. Supplemental materials containing the computer code
are available online.


title: Unary negation

abstract:
  We study fragments of first-order logic and of least fixed point logic that
allow only unary negation: negation of formulas with at most one free variable.
These logics generalize many interesting known formalisms, including modal
logic and the $\mu$-calculus, as well as conjunctive queries and monadic
Datalog. We show that satisfiability and finite satisfiability are decidable
for both fragments, and we pinpoint the complexity of satisfiability, finite
satisfiability, and model checking. We also show that the unary negation
fragment of first-order logic is model-theoretically very well behaved. In
particular, it enjoys Craig Interpolation and the Projective Beth Property.


title: On the relation between dynamics and geometry in GRBs

abstract:
  We estimate the initial bulk Lorentz factors Gamma_0 for GRBs that show the
onset of the afterglow in their optical light curves. We find that Gamma_0 is
strongly correlated with both the isotropic equivalent luminosity L_iso and
energy E_iso and, with a larger scatter, also with the rest frame peak energy
E_peak. These new correlations allow us to interpret the spectral energy
correlations E_peak-L_iso (-E_iso) as a sequence of Gamma_0 factors. By
accounting for the beaming effects, we find that the comoving frame properties
of GRBs result clustered around typical values (e.g. L'_iso~5x10^48 erg/s).
Moreover, it is theoretically predicted that there should be a link between the
jet dynamics (Gamma_0) and its geometry (theta_jet). Through a population
synthesis code we reconstruct the Gamma_0 and theta_jet distributions and
search for a possible link between them. We find that Gamma_0 and theta_jet in
GRBs should have log-normal distributions and they should be anti correlated
(i.e. theta_jet^2*Gamma_0=const).


title: Edgeworth expansion for functionals of continuous diffusion processes

abstract:
  This paper presents new results on the Edgeworth expansion for high frequency
functionals of continuous diffusion processes. We derive asymptotic expansions
for weighted functionals of the Brownian motion and apply them to provide the
second order Edgeworth expansion for power variation of diffusion processes.
Our methodology relies on martingale embedding, Malliavin calculus and stable
central limit theorems for semimartingales. Finally, we demonstrate the density
expansion for studentized statistics of power variations.


title:
Point spread function due to multiple scattering of light in the
  atmosphere

abstract:
  The atmospheric scattering of light has a significant influence on results of
optical observations of air showers. It causes attenuation of direct light from
the shower, but also contributes a delayed signal to the observed light. The
scattering of light therefore should be accounted for, both in simulations of
air shower detection and reconstruction of observed events. In this work a
Monte Carlo simulation of multiple scattering of light has been used to
determine the contribution of the scattered light in observations of a point
source of light. Results of the simulations and a parameterization of the
angular distribution of the scattered light contribution to the observed signal
(the point spread function) are presented.


title:
Why the globular cluster NGC 6752 contains no sodium-rich
  second-generation AGB star

abstract:
  (Abridged) Globular clusters host multiple stellar populations showing
different sodium enrichments. These various populations can be observed along
the main sequence, red giant and horizontal branch phases. Recently it was
shown, however, that at least in the globular cluster NGC 6752, no sodium-rich
stars are observed along the early asymptotic giant branch, posing an apparent
problem for stellar evolution. We present an explanation for this lack of
sodium-rich stars in this region of the colour-magnitude diagram.


title: Learning Transformations for Clustering and Classification

abstract:
  A low-rank transformation learning framework for subspace clustering and
classification is here proposed. Many high-dimensional data, such as face
images and motion sequences, approximately lie in a union of low-dimensional
subspaces. The corresponding subspace clustering problem has been extensively
studied in the literature to partition such high-dimensional data into clusters
corresponding to their underlying low-dimensional subspaces. However,
low-dimensional intrinsic structures are often violated for real-world
observations, as they can be corrupted by errors or deviate from ideal models.
We propose to address this by learning a linear transformation on subspaces
using matrix rank, via its convex surrogate nuclear norm, as the optimization
criteria. The learned linear transformation restores a low-rank structure for
data from the same subspace, and, at the same time, forces a a maximally
separated structure for data from different subspaces. In this way, we reduce
variations within subspaces, and increase separation between subspaces for a
more robust subspace clustering. This proposed learned robust subspace
clustering framework significantly enhances the performance of existing
subspace clustering methods. Basic theoretical results here presented help to
further support the underlying framework. To exploit the low-rank structures of
the transformed subspaces, we further introduce a fast subspace clustering
technique, which efficiently combines robust PCA with sparse modeling. When
class labels are present at the training stage, we show this low-rank
transformation framework also significantly enhances classification
performance. Extensive experiments using public datasets are presented, showing
that the proposed approach significantly outperforms state-of-the-art methods
for subspace clustering and classification.


title: A laser setup for rubidium cooling dedicated to space applications

abstract:
  We present the complete characterization of a laser setup for rubidium
cooling dedicated to space applications. The experimental setup is realized
with commercial off-the-shelf fiber components suitable for space applications.
By frequency doubling two fiber laser diodes at 1560 nm, we produce the two
optical frequencies at 780 nm required for atomic cooling of $^{87}$Rb. The
first laser is locked on saturated absorption signal and long term frequency
drift has been canceled using a digital integrator. The optical frequency of
the second laser is controlled relatively to the first one by a frequency
comparison method. A full characterization of the setup, including frequency
stability evaluation and frequency noise measurement has been performed. The
optical frequency doubling module has been submitted to environmental tests to
verify its compatibility with space applications.


title: Symmetries of dynamical systems and convergent normal forms

abstract:
  It is shown that, under suitable conditions, involving in particular the
existence of analytic constants of motion, the presence of Lie point symmetries
can ensure the convergence of the transformation taking a vector field (or
dynamical system) into normal form


title:
An optimal fuzzy-PI force/motion controller to increase industrial robot
  autonomy

abstract:
  This paper presents a method for robot self-recognition and self-adaptation
through the analysis of the contact between the robot end effector and its
surrounding environment. Often, in off-line robot programming, the idealized
robotic environment (the virtual one) does not reflect accurately the real one.
In this situation, we are in the presence of a partially unknown environment
(PUE). Thus, robotic systems must have some degree of autonomy to overcome this
situation, especially when contact exists. The proposed force/motion control
system has an external control loop based on forces and torques exerted on the
robot end effector and an internal control loop based on robot motion. The
external control loop is tested with an optimal proportional integrative (PI)
and a fuzzy-PI controller. The system performance is validated with real-world
experiments involving contact in PUEs.


title: Direct off-line robot programming via a common CAD package

abstract:
  This paper focuses on intuitive and direct off-line robot programming from a
CAD drawing running on a common 3-D CAD package. It explores the most suitable
way to represent robot motion in a CAD drawing, how to automatically extract
such motion data from the drawing, make the mapping of data from the virtual
(CAD model) to the real environment and the process of automatic generation of
robot paths/programs. In summary, this study aims to present a novel CAD-based
robot programming system accessible to anyone with basic knowledge of CAD and
robotics. Experiments on different manipulation tasks show the effectiveness
and versatility of the proposed approach.


title:
CAD-based robot programming: The role of Fuzzy-PI force control in
  unstructured environments

abstract:
  More and more, new ways of interaction between humans and robots are desired,
something that allow us to program a robot in an intuitive way, quickly and
with a high-level of abstraction from the robot language. In this paper is
presented a CAD-based system that allows users with basic skills in CAD and
without skills in robot programming to generate robot programs from a CAD model
of a robotic cell. When the CAD model reproduces exactly the real scenario, the
system presents a satisfactory performance. On the contrary, when the CAD model
does not reproduce exactly the real scenario or the calibration process is
poorly done, we are dealing with uncertain (unstructured environment). In order
to minimize or eliminate the previously mentioned problems, it was introduced
sensory feedback (force and torque sensing) in the robotic framework. By
controlling the end-effector pose and specifying its relationship to the
interaction/contact forces, robot programmers can ensure that the robot
maneuvers in an unstructured environment, damping possible impacts and also
increasing the tolerance to positioning errors from the calibration process.
Fuzzy-PI reasoning was used as a force control technique. The effectiveness of
the proposed approach was evaluated in a series of experiments.


title:
Structure Learning of Probabilistic Logic Programs by Searching the
  Clause Space

abstract:
  Learning probabilistic logic programming languages is receiving an increasing
attention and systems are available for learning the parameters (PRISM,
LeProbLog, LFI-ProbLog and EMBLEM) or both the structure and the parameters
(SEM-CP-logic and SLIPCASE) of these languages. In this paper we present the
algorithm SLIPCOVER for "Structure LearnIng of Probabilistic logic programs by
searChing OVER the clause space". It performs a beam search in the space of
probabilistic clauses and a greedy search in the space of theories, using the
log likelihood of the data as the guiding heuristics. To estimate the log
likelihood SLIPCOVER performs Expectation Maximization with EMBLEM. The
algorithm has been tested on five real world datasets and compared with
SLIPCASE, SEM-CP-logic, Aleph and two algorithms for learning Markov Logic
Networks (Learning using Structural Motifs (LSM) and ALEPH++ExactL1). SLIPCOVER
achieves higher areas under the precision-recall and ROC curves in most cases.


title: Discretization and fitting of nominal data for autonomous robots

abstract:
  This paper presents methodologies to discretize nominal robot paths extracted
from 3-D CAD drawings. Behind robot path discretization is the ability to have
a robot adjusting the traversed paths so that the contact between robot tool
and work-piece is properly maintained. In addition, a hybrid force/motion
control system based on Fuzzy-PI control is proposed to adjust robot paths with
external sensory feedback. All these capabilities allow to facilitate the robot
programming process and to increase the robots autonomy.


title: Discrete q-Hermite polynomials: An elementary approach

abstract:
  We present a simple approach to discrete q-Hermite polynomials with special
emphasis on analogies with the classical case.


title: Unitary cycles on Shimura curves and the Shimura lift II

abstract:
  We consider two families of arithmetic divisors defined on integral models of
Shimura curves. The first was studied by Kudla, Rapoport and Yang, who proved
that if one assembles these divisors in a formal generating series, one obtains
the q-expansion of a modular form of weight 3/2. The present work concerns the
Shimura lift of this modular form: we identify the Shimura lift with a
generating series comprised of unitary divisors, which arose in recent work of
Kudla and Rapoport regarding cycles on Shimura varieties of unitary type. In
the prequel to this paper, the author considered the geometry of the two
families of cycles; these results are combined with the archimedian
calculations found in this work in order to establish the theorem. In
particular, we obtain new examples of modular generating series whose
coefficients lie in arithmetic Chow groups of Shimura varieties.


title:
Real-Time and Continuous Hand Gesture Spotting: an Approach Based on
  Artificial Neural Networks

abstract:
  New and more natural human-robot interfaces are of crucial interest to the
evolution of robotics. This paper addresses continuous and real-time hand
gesture spotting, i.e., gesture segmentation plus gesture recognition. Gesture
patterns are recognized by using artificial neural networks (ANNs) specifically
adapted to the process of controlling an industrial robot. Since in continuous
gesture recognition the communicative gestures appear intermittently with the
noncommunicative, we are proposing a new architecture with two ANNs in series
to recognize both kinds of gesture. A data glove is used as interface
technology. Experimental results demonstrated that the proposed solution
presents high recognition rates (over 99% for a library of ten gestures and
over 96% for a library of thirty gestures), low training and learning time and
a good capacity to generalize from particular situations.


title: Vertices of Lie Modules

abstract:
  Let Lie(n) be the Lie module of the symmetric group S_n over a field F of
characteristic p>0, that is, Lie(n) is the left ideal of FS_n generated by the
Dynkin-Specht-Wever element. We study the problem of parametrizing
non-projective indecomposable summands of Lie(n), via describing their vertices
and sources. Our main result shows that this can be reduced to the case when n
is a power of p. When n=9 and p=3, and when n=8 and p=2, we present a precise
answer. This suggests a possible parametrization for arbitrary prime powers.


title:
High-level robot programming based on CAD: dealing with unpredictable
  environments

abstract:
  Purpose - The purpose of this paper is to present a CAD-based human-robot
interface that allows non-expert users to teach a robot in a manner similar to
that used by human beings to teach each other.
  Design/methodology/approach - Intuitive robot programming is achieved by
using CAD drawings to generate robot programs off-line. Sensory feedback allows
minimization of the effects of uncertainty, providing information to adjust the
robot paths during robot operation.
  Findings - It was found that it is possible to generate a robot program from
a common CAD drawing and run it without any major concerns about calibration or
CAD model accuracy.
  Research limitations/implications - A limitation of the proposed system has
to do with the fact that it was designed to be used for particular
technological applications.
  Practical implications - Since most manufacturing companies have CAD packages
in their facilities today, CAD-based robot programming may be a good option to
program robots without the need for skilled robot programmers.
  Originality/value - The paper proposes a new CAD-based robot programming
system. Robot programs are directly generated from a CAD drawing running on a
commonly available 3D CAD package (Autodesk Inventor) and not from a
commercial, computer aided robotics (CAR) software, making it a simple CAD
integrated solution. This is a low-cost and low-setup time system where no
advanced robot programming skills are required to operate it. In summary, robot
programs are generated with a high-level of abstraction from the robot
language.


title:
Baa.pl: A tool to evaluate de novo genome assemblies with RNA
  transcripts

abstract:
  Assessing the correctness of genome assemblies is an important step in any
genome project. Several methods exist, but most are computationally intensive
and, in some cases, inappropriate. Here I present baa.pl, a fast and
easy-to-use program that uses transcript data to evaluate genomic assemblies.
Through simulations using human chromosome 22, I show that baa.pl excels at
detecting levels of missing sequence and contiguity. The program is freely
available at: https://github.com/josephryan/baa.pl


title:
Angular momentum-area proportionality of extremal charged black holes in
  odd dimensions

abstract:
  Extremal rotating black holes in Einstein-Maxwell theory feature two
branches. On the branch emerging from the Myers-Perry solutions their angular
momentum is proportional to their horizon area, while on the branch emerging
from the Tangherlini solutions their angular momentum is proportional to their
horizon angular momentum. The transition between these branches occurs at a
critical value of the charge, which depends on the value of the angular
momentum. However, when a dilaton is included, the angular momentum is always
proportional to the horizon area.


title:
A low-cost laser scanning solution for flexible robotic cells: spray
  coating

abstract:
  In this paper, an adaptive and low-cost robotic coating platform for small
production series is presented. This new platform presents a flexible
architecture that enables fast/automatic system adaptive behaviour without
human intervention. The concept is based on contactless technology, using
artificial vision and laser scanning to identify and characterize different
workpieces travelling on a conveyor. Using laser triangulation, the workpieces
are virtually reconstructed through a simplified cloud of three-dimensional
(3D) points. From those reconstructed models, several algorithms are
implemented to extract information about workpieces profile (pattern
recognition), size, boundary and pose. Such information is then used to on-line
adjust the base robot programmes. These robot programmes are off-line generated
from a 3D computer-aided design model of each different workpiece profile.
Finally, the robotic manipulator executes the coating process after its base
programmes have been adjusted. This is a low-cost and fully autonomous system
that allows adapting the robots behaviour to different manufacturing
situations. It means that the robot is ready to work over any piece at any
time, and thus, small production series can be reduced to as much as a
one-object series. No skilled workers and large setup times are needed to
operate it. Experimental results showed that this solution proved to be
efficient and can be applied not only for spray coating purposes but also for
many other industrial processes (automatic manipulation, pick-and-place,
inspection, etc.).


title: Accelerometer-based control of an industrial robotic arm

abstract:
  Most of industrial robots are still programmed using the typical teaching
process, through the use of the robot teach pendant. In this paper is proposed
an accelerometer-based system to control an industrial robot using two low-cost
and small 3-axis wireless accelerometers. These accelerometers are attached to
the human arms, capturing its behavior (gestures and postures). An Artificial
Neural Network (ANN) trained with a back-propagation algorithm was used to
recognize arm gestures and postures, which then will be used as input in the
control of the robot. The aim is that the robot starts the movement almost at
the same time as the user starts to perform a gesture or posture (low response
time). The results show that the system allows the control of an industrial
robot in an intuitive way. However, the achieved recognition rate of gestures
and postures (92%) should be improved in future, keeping the compromise with
the system response time (160 milliseconds). Finally, the results of some tests
performed with an industrial robot are presented and discussed.


title: Excitons and biexcitons in symmetric electron-hole bilayers

abstract:
  Symmetric electron-hole bilayer systems have been studied at zero temperature
using the diffusion quantum Monte Carlo method. A flexible trial wave function
is used that can describe fluid, excitonic and biexcitonic phases. We calculate
condensate fractions and pair correlation functions for a large number of
densities rs and layer separations d. At small d we find a one-component fluid
phase, an excitonic fluid phase, and a biexcitonic fluid phase, and the
transitions among them appear to be continuous. At d = 0, excitons appear to
survive down to about rs = 0.5 a.u., and biexcitons form at rs > 2.5 a.u.


title: Laser assisted Compton scattering of X-ray photons

abstract:
  The Compton scattering of X-ray photons, assisted by a short intense optical
laser pulse, is discussed. The differential scattering cross section reveals
the interesting feature that the main Klein-Nishina line is accompanied by a
series of side-lines forming a broad plateau where up to ${\cal O} (10^3)$
laser photons participate simultaneously in a single scattering event. An
analytic formula for the width of the plateau is given. Due to the non-linear
mixing of X-ray and laser photons a frequency dependent rotation of the
polarization of the final state X-ray photons relative to the scattering plane
emerges. A consistent description of the scattering process with short laser
pulses requires to work with X-ray pulses. An experimental investigation can be
accomplished, e.g., at LCLS or the European XFEL in the near future.


title:
High-level programming and control for industrial robotics: using a
  hand-held accelerometer-based input device for gesture and posture
  recognition

abstract:
  Purpose - Most industrial robots are still programmed using the typical
teaching process, through the use of the robot teach pendant. This is a tedious
and time-consuming task that requires some technical expertise, and hence new
approaches to robot programming are required. The purpose of this paper is to
present a robotic system that allows users to instruct and program a robot with
a high-level of abstraction from the robot language.
  Design/methodology/approach - The paper presents in detail a robotic system
that allows users, especially non-expert programmers, to instruct and program a
robot just showing it what it should do, in an intuitive way. This is done
using the two most natural human interfaces (gestures and speech), a force
control system and several code generation techniques. Special attention will
be given to the recognition of gestures, where the data extracted from a motion
sensor (three-axis accelerometer) embedded in the Wii remote controller was
used to capture human hand behaviours. Gestures (dynamic hand positions) as
well as manual postures (static hand positions) are recognized using a
statistical approach and artificial neural networks.
  Practical implications - The key contribution of this paper is that it offers
a practical method to program robots by means of gestures and speech, improving
work efficiency and saving time.
  Originality/value - This paper presents an alternative to the typical robot
teaching process, extending the concept of human-robot interaction and
co-worker scenario. Since most companies do not have engineering resources to
make changes or add new functionalities to their robotic manufacturing systems,
this system constitutes a major advantage for small- to medium-sized
enterprises.


title:
The Linearized Bregman Method via Split Feasibility Problems: Analysis
  and Generalizations

abstract:
  The linearized Bregman method is a method to calculate sparse solutions to
systems of linear equations. We formulate this problem as a split feasibility
problem, propose an algorithmic framework based on Bregman projections and
prove a general convergence result for this framework. Convergence of the
linearized Bregman method will be obtained as a special case. Our approach also
allows for several generalizations such as other objective functions,
incremental iterations, incorporation of non-gaussian noise models or box
constraints.


title: UV diagnostic of porosity-free mass-loss estimates in B stars

abstract:
  We seek to establish evidence in UV P Cygni line profiles that the signs of
wind clumping and porosity vary with velocity. We aim to demonstrate
empirically that while at most wind velocities optically thick clumps cover
only a fraction of the stellar surface, close to the terminal velocity where
narrow absorption components (NACs) appear in UV lines the covering factor is
approximately unity. SEI line-synthesis models are used to determine the radial
optical depths of blue and red components of the SiIV 1400 resonance line
doublet in a sample of 12 B0 to B4 supergiants. We focus on stars with well
developed NACs and relatively low terminal velocity so that the SiIV doublet
components can be treated as radiatively decoupled and formed independently.
For all 12 stars the mean optical depth ratio of the blue to red components is
closer to ~ 2 (i.e. the ratio of oscillator strengths) in the NACs than at
intermediate and lower velocities. The product of mass-loss rate and Si^3+ ion
fraction calculated from the NAC optical depths is a factor of ~ 2 to 9 higher
compared to mass-loss values sampled at ~ 0.4 to 0.6 of the terminal velocity.
Since the wind effectively becomes `smooth' at the high NAC velocities and the
column density is uniformly distributed over the stellar disk, the optical
depths of the NACs are not seriously affected by porosity and this feature thus
provides the most reliable measurement of mass-loss rate in the UV lines.
Applications of this result to the weak-wind problem of late O-dwarf stars and
the "PV mass loss discordance" in early O supergiants are discussed.


title: Pressurised xenon as scintillator for gamma spectroscopy

abstract:
  Detectors based on liquid or gas xenon have been used and are in use for a
number of applications, in particular for the detection of gamma rays. Xenon is
a well-suited medium for gamma spectroscopy thanks to its high atomic number
and, consequently, large cross-section for photo-electric absorption. This
paper presents experimental studies of high pressure xenon as a scintillator,
with the aim of developing a gamma ray detector for the detection of Special
Nuclear Materials (SNM). The first goal was to study the dependence of the
light yield and of the energy resolution on the thermodynamic conditions. We
present preliminary results from an optimised version of the detector.


title: The Technicolor Higgs in the Light of LHC Data

abstract:
  We consider scenarios in which the 125 GeV resonance observed at the Large
Hadron Collider is a Technicolor (TC) isosinglet scalar, the TC Higgs. By
comparison with quantum chromodynamics, we argue that the couplings of the TC
Higgs to the massive weak bosons are very close to the Standard Model (SM)
values. The couplings to photons and gluons are model-dependent, but close to
the SM values in several TC theories. The couplings of the TC Higgs to SM
fermions are due to interactions beyond TC, such as Extended Technicolor: if
such interactions successfully generate mass for the SM fermions, we argue that
the couplings of the latter to the TC Higgs are also SM-like.
  We suggest a generic parameterization of the TC Higgs interactions with SM
particles that accommodates a large class of TC models, and we perform a fit of
these parameters to the Higgs LHC data. The fit reveals regions of parameter
space where the form factors are of order unity and consistent with data at the
95% CL, in agreement with expectations in TC theories. This indicates that the
discovered Higgs boson is consistent with the TC Higgs hypothesis for several
TC theories.


title: A Holographic Study on Vector Condensate Induced by a Magnetic Field

abstract:
  We study a holographic model with vector condensate by coupling the anti-de
Sitter gravity to an Abelian gauge field and a charged vector field in $(3+1)$
dimensional spacetime. In this model there exists a non-minimal coupling of the
vector filed to the gauge field. We find that there is a critical temperature
below which the charged vector condenses via a second order phase transition.
The DC conductivity becomes infinite and the AC conductivity develops a gap in
the condensed phase. We study the effect of a background magnetic field on the
system. It is found that the background magnetic field can induce the
condensate of the vector field even in the case without chemical
potential/charge density. In the case with non-vanishing charge density, the
transition temperature raises with the applied magnetic field, and the
condensate of the charged vector operator forms a vortex lattice structure in
the spatial directions perpendicular to the magnetic field.


title:
Generalization of Levi-Civita regularization in the restricted
  three-body problem

abstract:
  A family of polynomial coupled function of $n$ degree is proposed, in order
to generalize the Levi-Civita regularization method, in the restricted
three-body problem. Analytical relationship between polar radii in the physical
plane and in the regularized plane are established; similar for polar angles.
As a numerical application, trajectories of the test particle using polynomial
functions of $2, 3,..., 8$ degree are obtained. For the polynomial of second
degree, the Levi-Civita regularization method is found.


title:
Spectral estimates and basis properties for self-adjoint block operator
  matrices

abstract:
  In the first part of this manuscript a relationship between the spectrum of
self-adjoint operator matrices and the spectra of their diagonal entries is
found. This leads to enclosures for spectral points and in particular,
enclosures for eigenvalues. We also consider graph invariant subspaces, and
their corresponding angular operators. The existence of a bounded angular
operator leads to basis properties of the first component of eigenvectors of
operator matrices for which the corresponding eigenvalues lie in a half line.
The results are applied to an example from magnetohydrodynamics.


title:
Convergence of an Adaptive Finite Element Method for Distributed Flux
  Reconstruction

abstract:
  We shall establish the convergence of an adaptive conforming finite element
method for the reconstruction of the distributed flux in a diffusion system.
The adaptive method is based on a posteriori error estimators for the
distributed flux, state and costate variables. The sequence of discrete
solutions produced by the adaptive algorithm is proved to converge to the true
triplet satisfying the optimality conditions in the energy norm and the
corresponding error estimator converges to zero asymptotically.


title: On the neutrino mass ordering and flavor mixing structure

abstract:
  Whether the neutrino mass spectrum is normal (m_1 < m_2 < m_3) or abnormal
(m_3 < m_1 < m_2) remains an open question, but we show that the latter
possibility looks quite unnatural when it is related to the lepton flavor
mixing matrix U in a way similar to the reasonable correlation between the
quark mass spectrum and the quark flavor mixing matrix. Taking into account the
freedom in choosing the basis of weak interactions, we make a novel prediction
for |U_{tau 1}|/|U_{tau 2}| in terms of the three neutrino masses in the large
tau mass limit. This result is testable, and it implies that the normal
neutrino mass ordering is more likely to coincide with the observed structure
of U.


title: Puzzle Encryption Algorithm

abstract:
  This document describes the symmetric encryption algorithm called Puzzle. It
is free and open. The objective of this paper is to get an opinion about its
security from the cryptology community. It is separated in two parts, a
technical description of the algorithm and its cryptanalysis. The algorithm has
some interesting properties :
  The block size is variable and unknown from an attacker. The size of the key
has no limit and is unknown from an attacker. The key size does not affect the
algorithm speed (using a 256 bit key is the same as using a 1024 bit key). The
algorithm is much faster than the average cryptographic function. Experimental
test showed 600 Mo/s - 4 cycles/byte on an Intel Core 2 Duo P8600 2.40GHz and
1,2 Go/s - 2 cycles/byte on an Intel i5-3210M 2.50GHz. Both CPU had only 2
cores.


title: The scalar pion form factor in two-flavor lattice QCD

abstract:
  We calculate the scalar form factor of the pion using two dynamical flavors
of non-perturbatively $\mathcal{O}(a)$-improved Wilson fermions, including both
the connected and the disconnected contribution to the relevant correlation
functions. We employ the calculation of all-to-all propagators using stochastic
sources and a generalized hopping parameter expansion. From the form factor
data at vanishing momentum transfer, $Q^2=0$, and two non-vanishing $Q^2$ we
obtain an estimate for the scalar radius $\left<r^2\right>^\pi_{_{\rm S}}$ of
the pion at one value of the lattice spacing and for five different pion
masses. Using Chiral Perturbation Theory at next-to-leading order, we find
$\left<r^2\right>^\pi_{_{\rm S}}=0.635\pm0.016$ fm$^2$ at the physical pion
mass (statistical error only). This is in good agreement with the
phenomenological estimate from $\pi\pi$-scattering. The inclusion of the
disconnected contribution is essential for achieving this level of agreement.


title: Majorana Fermions on a Lattice and a Matrix Problem

abstract:
  We investigate matrix problems arising in the study of Majorana Fermions on a
lattice.


title: More on the identity of Chaundy and Bullard

abstract:
  Some ramifications of the identity of Chaundy and Bullard are presented. We
discuss its homogeneous form and its relations to other identities, as well as
extensions to more variables and more parameters.


title:
Statistical mechanics of the coagulation-diffusion process with a
  stochastic reset

abstract:
  The effects of a stochastic reset, to its initial configuration, is studied
in the exactly solvable one-dimensional coagulation-diffusion process. A finite
resetting rate leads to a modified non-equilibrium stationary state. If in
addition the input of particles at a fixed given rate is admitted, a
competition between the resetting and the input rates leads to a non-trivial
behaviour of the particle-density in the stationary state. From the exact
inter-particle probability distribution, a simple physical picture emerges: the
reset mainly changes the behaviour at larger distance scales, while at smaller
length scales, the non-trivial correlation of the model without a reset
dominates.

categories: cond-mat.stat-mech math-ph math.MP nlin.SI


title: Analysis of the possible Blazhko-effect Cepheid V473 Lyrae

abstract:
  V473 Lyrae is a peculiar Galactic Cepheid, showing strong amplitude
modulation that resembles the Blazhko-effect observed in RR Lyrae stars. We
collected data spanning several modulation cycles and started a detailed
analysis. The first results indicate that the star shows both amplitude and
phase modulations with an average period of 1204 days, but both the cycle
length and the strength of the modulation are subjected to considerable
variations. A possible quintuplet component in the Fourier spectrum and
additional period changes were also detected.


title: Daehee Numbers and polynomials

abstract:
  We consider the Witt-type formula for Daehee numbrers and polynomials and
investigate some properties of those numbers and polynomials. In particular,
Daehee numbers are closely related to higher-order Bernoulli numbers and
Bernoulli numbers of the second kind.


title: On Thermal Vacuum Radiation of Nanoparticles and Their Ensembles

abstract:
  Radiant emittance of dimers and ensembles of particles consisting of gold,
graphite and silica glass nanoparticles in vacuum is studied numerically based
on the fluctuation-electromagnetic theory. The presence of neighboring
particles of the same temperature causes an oscillating character of radiant
emittance (per one particle) depending on the particle size, interparticle
distance and temperature. We conclude that an ensemble of particles could be a
much more intense source of thermal radiation than an equivalent solid body
with the same outer surface area. Alternatively, when the neighboring particles
create a significant screening effect (silica), an ensemble of particles could
be a very good heat protector.


title:
Variance of the Number of Zeroes of Shift-Invariant Gaussian Analytic
  Functions

abstract:
  Following Wiener, we consider the zeroes of Gaussian analytic functions in a
strip in the complex plane, with translation-invariant distribution. We show
that the variance of the number of zeroes in a long horizontal rectangle
$[0,T]\times [a,b]$ is asymptotically between $cT$ and $CT^2$, with positive
constants $c$ and $C$. We also supply with conditions (in terms of the spectral
measure) under which the variance asymptotically grows linearly, as a quadratic
function of $T$, or has intermediate growth.


title:
Time-dependent equation for the magnetic order parameter near the
  quantum critical point in multiband superconductors with a spin density wave

abstract:
  Using a simple two-band model for Fe-based pnictides and the generalized
Eilenberger equation, we present a microscopic derivation of a time-dependent
equation for the amplitude of the spin density wave near the quantum critical
point where it turns to zero. This equation describes the dynamics of the
magnetic---$m$, as well as the superconducting order parameter---$\Delta$. It
is valid at low temperatures $T$ and small $m$ (${T, m \ll \Delta}$) in a
region of coexistence of both order parameters, $m$ and $\Delta$. The boundary
of this region is found in the space of the nesting parameter
$\{\mu_{0},\mu_{\phi}\}$ where $\mu_{0}$ describes the relative position of the
electron and the hole pockets on the energy scale, and $\mu_{\phi}$ accounts
for the ellipticity of the electron pocket. At low $T$ the number of
quasiparticles is small due to the presence of the energy gap $\Delta$, and
therefore the quasiparticles do not play a role in the relaxation of $m$. This
circumstance allows one to derive the time-dependent equation for $m$ in
contrast to the case of conventional superconductors for which the
time-dependent Ginzburg--Landau equation can be derived near $T_{\text{c}}$
only in some special cases (high concentration of paramagnetic impurities. In
the stationary case the derived equation is valid at arbitrary temperatures. We
find a solution of the stationary equation which describes a domain wall in the
magnetic structure. In the center of the domain wall the superconducting order
parameter has a maximum, which means a local enhancement of superconductivity.
Using the derived time-dependent equation for $m$, we investgate also the
stability of a uniform commensurate SDW and obtain the values of $\{\mu_{0},
\mu_{\phi}\}$ at which the first order transition into the state with ${m = 0}$
takes place or the transition to the state with an inhomogeneous SDW occurs.


title: On wheel-free graphs

abstract:
  A wheel is a graph formed by a chordless cycle and a vertex that has at least
three neighbors in the cycle. We prove that every 3-connected graph that does
not contain a wheel as a subgraph is in fact minimally 3-connected. We give a
new proof of a theorem of Thomassen and Toft: every graph that does not contain
a wheel as a subgraph is 3-colorable.


title: Phase lags of solar hemispheric cycles

abstract:
  The North-South asymmetry of solar activity is variable in time and strength.
We analyse the long-term variation of the phase lags of hemispheric cycles and
check a conjectured relationship between these phase lags and the hemispheric
cycle strengths. Sunspot data are used from cycles 12-23 in which the
separation of northern and southern hemispheres is possible. The centers of
mass of the hemispheric cycle profiles were used to study the phase relations
and relative strengths of the hemispheric cycles. This approach considers a
cycle as a whole and disregards the short-term fluctuations of the cycle time
profile. The phase of the hemispheric cycles shows an alternating variation:
the northern cycle leads in 4 cycles and follows in 4 cycles. No significant
relationship is found between the phase and strength differences of the
hemispheric cycles.
  The period of 4+4 cycles appears to be close to the Gleissberg cycle and may
provide a key to its physical background. It may raise a new aspect in the
solar dynamo mechanism because it needs a very long memory.


title: Cheeger's constant and the first eigenvalue of a closed Finsler manifold

abstract:
  In this paper, we consider Cheeger's constant and the first eigenvalue of the
nonlinear Laplacian on closed Finsler manifolds. Being based on these, we
establish Cheeger's inequality and Buser's inequality for closed Finsler
manifolds.


title:
Law of iterated logarithm and invariance principle for one-parameter
  families of interval maps

abstract:
  We show that for almost every map in a transversal one-parameter family of
piecewise expanding unimodal maps the Birkhoff sum of suitable observables
along the forward orbit of the turning point satisfies the law of iterated
logarithm. This result will follow from an almost sure invariance principle for
the Birkhoff sum, as a function on the parameter space. Furthermore, we obtain
a similar result for general one-parameter families of piecewise expanding maps
on the interval.


title:
The Superconducting Toroid for the New International AXion Observatory
  (IAXO)

abstract:
  IAXO, the new International AXion Observatory, will feature the most
ambitious detector for solar axions to date. Axions are hypothetical particles
which were postulated to solve one of the puzzles arising in the standard model
of particle physics, namely the strong CP (Charge conjugation and Parity)
problem. This detector aims at achieving a sensitivity to the coupling between
axions and photons of one order of magnitude beyond the limits of the current
detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a
high-magnetic field distributed over a very large volume to convert solar
axions to detectable X-ray photons. Inspired by the ATLAS barrel and end-cap
toroids, a large superconducting toroid is being designed. The toroid comprises
eight, one meter wide and twenty one meters long racetrack coils. The assembled
toroid is sized 5.2 m in diameter and 25 m in length and its mass is about 250
tons. The useful field in the bores is 2.5 T while the peak magnetic field in
the windings is 5.4 T. At the operational current of 12 kA the stored energy is
500 MJ. The racetrack type of coils are wound with a reinforced Aluminum
stabilized NbTi/Cu cable and are conduction cooled. The coils optimization is
shortly described as well as new concepts for cryostat, cold mass, supporting
structure and the sun tracking system. Materials selection and sizing,
conductor, thermal loads, the cryogenics system and the electrical system are
described. Lastly, quench simulations are reported to demonstrate the system's
safe quench protection scheme.


title: A new approach on helices in pseudo-Riemannian manifolds

abstract:
  In this paper, we give a definition of harmonic curvature functions in terms
of V_{n} and define a new kind of slant helix which is called V_{n}-slant helix
in n-dimensional pseudo-Riemannian manifold. Also, we give important
characterizations about the helix.


title:
Origin of the unusual strong suppression of low frequency
  antiferromagnetic fluctuations in underdoped HgBa$_2$CuO$_{4+\delta}$

abstract:
  Generally strong charge and magnetic inhomogeneities are observed in NQR/NMR
experiments on underdoped cuprates. It is not the case for the underdoped
HgBa$_2$CuO$_{4+\delta}$, the most symmetric and highest T$_c$ single layer
cuprate, whose magnetic inhomogeneity is strongly suppressed. Also neutron
scattering experiments reveal a unique pair of weakly dispersive magnetic modes
in this material. We propose that these special properties stem from the
symmetric positioning of the O-dopants between adjacent CuO$_2$ layers that
lead to a strong superexchange interaction between a pair of hole spins. In
this Letter we present a theoretical model, which gives a consistent
explanation to the anomalous magnetic properties of this material.


title:
Universality of the local regime for the block band matrices with a
  finite number of blocks

abstract:
  We consider the block band matrices, i.e. the Hermitian matrices $H_N$,
$N=|\Lambda|W$ with elements $H_{jk,\alpha\beta}$, where $j,k
\in\Lambda=[1,m]^d\cap \mathbb{Z}^d$ (they parameterize the lattice sites) and
$\alpha, \beta= 1,\ldots, W$ (they parameterize the orbitals on each site). The
entries $H_{jk,\alpha\beta}$ are random Gaussian variables with mean zero such
that $\langle
H_{j_1k_1,\alpha_1\beta_1}H_{j_2k_2,\alpha_2\beta_2}\rangle=\delta_{j_1k_2}\delta_{j_2k_1}
\delta_{\alpha_1\beta_2}\delta_{\beta_1\alpha_2} J_{j_1k_1},$ where
$J=1/W+\alpha\Delta/W$, $\alpha\le 1/4d$. This matrices are the special case of
Wegner's $W$-orbital models. Assuming that the number of sites $|\Lambda|$ is
finite, we prove universality of the local eigenvalue statistics of $H_N$ for
the energies $|\lambda_0|< \sqrt{2}$.


title: Duality in convex problems of Bolza over functions of bounded variation

abstract:
  This paper studies convex problems of Bolza in the conjugate duality
framework of Rockafellar. We parameterize the problem by a general Borel
measure which has direct economic interpretation in problems of financial
economics. We derive a dual representation for the optimal value function in
terms of continuous dual arcs and we give conditions for the existence of
solutions. Combined with well-known results on problems of Bolza over
absolutely continuous arcs, we obtain optimality conditions in terms of
extended Hamiltonian conditions.


title: A stochastic model of long-range interacting particles

abstract:
  We introduce a model of long-range interacting particles evolving under a
stochastic Monte Carlo dynamics, in which possible increase or decrease in the
values of the dynamical variables is accepted with preassigned probabilities.
For symmetric increments, the system at long times settles to the Gibbs
equilibrium state, while for asymmetric updates, the steady state is out of
equilibrium. For the associated Fokker-Planck dynamics in the thermodynamic
limit, we compute exactly the phase space distribution in the nonequilibrium
steady state, and find that it has a nontrivial form that reduces to the
familiar Gibbsian measure in the equilibrium limit.


title: On the Atkin Polynomials

abstract:
  We identify the Atkin polynomials in terms of associated Jacobi polynomials.
Our identificationthen takes advantage of the theory of orthogonal polynomials
and their asymptotics to establish many new properties of the Atkin
polynomials. This shows that co-recursive polynomials may lead to interesting
sets of orthogonal polynomials.


title:
High-Mobility Two-Dimensional Electron Gases at Oxide Interfaces:
  Origins and Opportunities

abstract:
  The discovery of two-dimensional electron gas (2DEG) at well-defined
interfaces between insulating complex oxides provides the opportunity for a new
generation of all-oxide electronics. Particularly, the 2DEG at the interface
between two perovskite insulators represented by the formula of ABO3, such as
LaAlO3 and SrTiO3, has attracted significant attention. In recent years,
progresses have been made to decipher the puzzle of the origin of interface
conduction, to design new types of oxide interfaces, and to improve the
interfacial carrier mobility significantly. These achievements open the door to
explore fundamental as well as applied physics of complex oxides. Here, we
review our recent experimental work on metallic and insulating interfaces
controlled by interfacial redox reactions in SrTiO3-based heterostructures. Due
to the presence of oxygen-vacancies at the SrTiO3 surface, metallic conduction
can be created at room temperature in perovskite-type interfaces when the
overlayer oxide ABO3 involves Al, Ti, Zr, or Hf elements at the B-sites.
Furthermore, relying on interface-stabilized oxygen vacancies, we have created
a new type of 2DEG at the heterointerface between SrTiO3 and a spinel
{\gamma}-Al2O3 epitaxial film with compatible oxygen ions sublattices. The
spinel/perovskite oxide 2DEG exhibits an electron mobility exceeding 100,000
cm2V-1s-1, more than one order of magnitude higher than those of hitherto
investigated perovskite-type interfaces. Our findings pave the way for design
of high-mobility all-oxide electronic devices and open a route towards studies
of mesoscopic physics with complex oxides.


title: Solving optimal stopping problems via empirical dual optimization

abstract:
  In this paper we consider a method of solving optimal stopping problems in
discrete and continuous time based on their dual representation. A novel and
generic simulation-based optimization algorithm not involving nested
simulations is proposed and studied. The algorithm involves the optimization of
a genuinely penalized dual objective functional over a class of adapted
martingales. We prove the convergence of the proposed algorithm and demonstrate
its efficiency for optimal stopping problems arising in option pricing.


title:
Effect of disorder on condensation in the lattice gas model on a random
  graph

abstract:
  The lattice gas model of condensation in a heterogeneous pore system,
represented by a random graph of cells, is studied using an exact analytical
solution. A binary mixture of pore cells with different coordination numbers is
shown to exhibit two phase transitions as a function of chemical potential in a
certain temperature range. Heterogeneity in interaction strengths is
demonstrated to reduce the critical temperature and, for large enough degree of
disorder, divides the cells into ones which are either on average occupied or
unoccupied. Despite treating the pore space loops in a simplified manner, the
random-graph model provides a good description of condensation in porous
structures containing loops. This is illustrated by considering capillary
condensation in a structural model of mesoporous silica SBA-15.


title: Measurement of a spin-1 system

abstract:
  We derive exact formulas describing an indirect von Neumann measurement of a
spin-1 system. The results hold for any interaction strength and for an
arbitrary output variable $\Hat{O}$.


title: Exploring the Boundaries of Monad Tensorability on Set

abstract:
  We study a composition operation on monads, equivalently presented as large
equational theories. Specifically, we discuss the existence of tensors, which
are combinations of theories that impose mutual commutation of the operations
from the component theories. As such, they extend the sum of two theories,
which is just their unrestrained combination. Tensors of theories arise in
several contexts; in particular, in the semantics of programming languages, the
monad transformer for global state is given by a tensor. We present two main
results: we show that the tensor of two monads need not in general exist by
presenting two counterexamples, one of them involving finite powerset (i.e. the
theory of join semilattices); this solves a somewhat long-standing open
problem, and contrasts with recent results that had ruled out previously
expected counterexamples. On the other hand, we show that tensors with bounded
powerset monads do exist from countable powerset upwards.


title: Large spheres motion in a non homogeneous turbulent flow

abstract:
  We investigate the dynamics of very large particles freely advected in a
turbulent von Karman flow. Contrary to other experiments for which the particle
dynamics is generally studied near the geometrical center of the flow, we track
the particles in the whole experiment volume. We observe a strong influence of
the mean structure of the flow that generates an unexpected large-scale
sampling effect for the larger particles studied; contrary to neutrally buoyant
particles of smaller yet finite sizes that exhibit no preferential
concentration in homogeneous and isotropic turbulence (Fiabane et al., Phys.
Rev. E 86(3), 2012). We find that particles whose diameter approaches the flow
integral length scale explore the von Karman flow non-uniformly, with a higher
probability to move in the vicinity of two tori situated near the poloidal
neutral lines. This preferential sampling is quite robust with respect to
changes of any varied parameters: Reynolds number, particle density and
particle surface roughness.


title: The Interrupted Power Law and The Size of Shadow Banking

abstract:
  Using public data (Forbes Global 2000) we show that the asset sizes for the
largest global firms follow a Pareto distribution in an intermediate range,
that is ``interrupted'' by a sharp cut-off in its upper tail, where it is
totally dominated by financial firms. This flattening of the distribution
contrasts with a large body of empirical literature which finds a Pareto
distribution for firm sizes both across countries and over time. Pareto
distributions are generally traced back to a mechanism of proportional random
growth, based on a regime of constant returns to scale. This makes our findings
of an ``interrupted'' Pareto distribution all the more puzzling, because we
provide evidence that financial firms in our sample should operate in such a
regime. We claim that the missing mass from the upper tail of the asset size
distribution is a consequence of shadow banking activity and that it provides
an (upper) estimate of the size of the shadow banking system. This estimate --
which we propose as a shadow banking index -- compares well with estimates of
the Financial Stability Board until 2009, but it shows a sharper rise in shadow
banking activity after 2010. Finally, we propose a proportional random growth
model that reproduces the observed distribution, thereby providing a
quantitative estimate of the intensity of shadow banking activity.


title:
Towards atomistic resolution structure of phosphatidylcholine glycerol
  backbone and choline headgroup at different ambient conditions

abstract:
  Phospholipids are essential building blocks of biological membranes. Despite
of vast amount of accurate experimental data the atomistic resolution
structures sampled by the glycerol backbone and choline headgroup in
phoshatidylcholine bilayers are not known. Atomistic resolution molecular
dynamics simulation model would automatically resolve the structures giving an
interpretation of experimental results, if the model would reproduce the
experimental data. In this work we compare the C-H bond vector order parameters
for glycerol backbone and choline headgroup between 14 different atomistic
resolution models and experiments in fully hydrated lipid bilayer. The current
models are not accurately enough to resolve the structure. However, closer
inspection of three best performing models (CHARMM36, GAFFlipid and MacRog)
suggest that improvements in the sampled dihedral angle distributions would
potentilly lead to the model which would resolve the structure. Despite of the
inaccuracy in the fully hydrated structures, the response to the dehydration,
i.e. P-N vector tilting more parallel to membrane normal, is qualitatively
correct in all models. The CHARMM36 and MacRog models describe the interactions
between lipids and cholesterol better than Berger/H\"oltje model. This work has
been, and continues to be, progressed and discussed through the blog:
nmrlipids.blogspot.fi. Everyone is invited to join the discussion and make
contributions through the blog. The manuscript will be eventually submitted to
an appropriate scientific journal. Everyone who has contributed to the work
through the blog will be offered coauthorship. For more details see:
nmrlipids.blogspot.fi.


title: R\^ole communautaire des capitalistes sociaux dans Twitter

abstract:
  Les capitalistes sociaux sont des utilisateurs de m\'edias sociaux tels que
Twitter, appliquant diverses techniques pour obtenir un maximum de
visibilit\'e. Ils peuvent \^etre n\'efastes \`a l'\'equilibre du service, dans
la mesure o\`u leurs comptes, en gagnant en importance sans r\'eelle raison de
contenu, rendent difficile l'acc\`es \`a un contenu pertinent. Dans ce travail,
nous nous int\'eressons \`a leur caract\'erisation d'un point de vue purement
topologique, i.e. sans consid\'erer la nature des contenus partag\'es. Nous
utilisons pour cela la notion de r\^ole communautaire, qui est bas\'ee sur la
structure de communaut\'es du r\'eseau \'etudi\'e. Nous apportons des
modifications \`a des mesures pr\'ec\'edemment d\'efinies \`a cet effet, et
proposons une m\'ethode objective de d\'etection des r\^oles. Nous appliquons
ensuite notre m\'ethode \`a l'analyse d'un r\'eseau repr\'esentant Twitter. Nos
r\'esultats montrent que les r\^oles que nous identifions via nos mesures se
r\'ev\`elent particuli\`erement coh\'erents par rapport aux capitalistes
sociaux du r\'eseau Twitter, dont le comportement est clairement
identifi\'e---Social capitalists are social media users taking advantage of
various methods to maximize their visibility. This results in artificially
important accounts, in the sense this importance is not backed by any real
content. The risk is then to see those accounts hiding relevant contents and
therefore preventing other users to access them. In this work, we want to
characterize social capitalists from a purely topological perspective, i.e.
without considering the nature of the shared contents. For this purpose, we use
the notion of community role, based on the community structure of the studied
network. We modify some measures previously designed for this matter, and
propose an objective method to determine roles. We then apply this method to
the analysis of a Twitter network. Our results show the roles identified
through our measures are particularly consistent with Twitter's social
capitalists, whose behavior was clearly identified.


title:
Probing the radial temperature structure of protoplanetary disks with
  Herschel/HIFI

abstract:
  Herschel/HIFI spectroscopic observations of CO J=10-9, CO J=16-15 and [CII]
towards HD 100546 are presented. The objective is to resolve the velocity
profile of the lines to address the emitting region of the transitions and
directly probe the distribution of warm gas in the disk. The spectra reveal
double-peaked CO line profiles centered on the systemic velocity, consistent
with a disk origin. The J=16-15 line profile is broader than that of the J=10-9
line, which in turn is broader than those of lower J transitions (6-5, 3-2,
observed with APEX), thus showing a clear temperature gradient of the gas with
radius. A power-law flat disk model is used to fit the CO line profiles and the
CO rotational ladder simultaneously, yielding a temperature of T_0=1100 \pm 350
K (at r_0 = 13 AU) and an index of q=0.85 \pm 0.1 for the temperature radial
gradient. This indicates that the gas has a steeper radial temperature gradient
than the dust (mean q_{dust} ~ 0.5), providing further proof of the thermal
decoupling of gas and dust at the disk heights where the CO lines form. The
[CII] line profile shows a strong single-peaked profile red-shifted by 0.5 km
s-1 compared to the systemic velocity. We conclude that the bulk of the [CII]
emission has a non-disk origin (e.g., remnant envelope or diffuse cloud).


title:
Vector meson fragmentation using a model with broken SU(3) at the
  Next-to-Leading Order

abstract:
  A detailed study of fragmentation of vector mesons at the next-to-leading
order (NLO) is given for e^+ e^- scattering. A model with broken SU(3) symmetry
uses three input fragmentation functions \alpha(x, Q^2), \beta(x,Q^2) and
\gamma(x,Q^2) and a strangeness suppression parameter \lambda to describe all
the light quark fragmentation functions for the entire vector meson octet. At a
starting low energy scale of Q_0^2 = 1.5 GeV^2 for three light quarks (u, d, s)
along with initial parameterization, the fragmentation functions are evolved
through DGLAP evolution equations at NLO and the cross-section is calculated.
The heavy quarks contribution are added in appropriate thresholds during
evolution. The results obtained are fitted at the momentum scale of \sqrt{s}=
91.2 GeV for LEP and SLD data. Good-quality fits are obtained for \rho, K^*,
\omega and \phi mesons, implying the consistency and efficiency of this model
that explains the fragmentation functions of vector mesons both at the leading
and the next to leading order in QCD. Keywords: vector meson, fragmentation,
SU(3) symmetry, NLO .


title: Asymptotically Lifshitz black hole solutions in F(R) gravity

abstract:
  We consider a class of spherically symmetric spacetime to obtain some
interesting solutions in F(R) gravity without matter field (pure gravity). We
investigate the geometry of the solutions and find that there is an essential
singularity at the origin. In addition, we show that there is an analogy
between obtained solutions with the black holes of Einstein-Lambda
-power-Maxwell-invariant theory. Furthermore, we find that these solutions are
equivalent to the asymptotically Lifshitz black holes. Also, we calculate
d^2F/dR^2 to examine the Dolgov-Kawasaki stability criterion.


title:
Deconvolution with application to estimation of sampling probabilities
  and the Horvitz-Thompson estimator

abstract:
  We elaborate on a deconvolution method, used to estimate the empirical
distribution of unknown parameters, as suggested recently by Efron (2013). It
is applied to estimating the empirical distribution of the 'sampling
probabilities' of m sampled items. The estimated empirical distribution is used
to modify the Horvitz-Thompson estimator. The performance of the modified
Horvitz-Thompson estimator is studied in two examples. In one example the
sampling probabilities are estimated based on the number of visits until a
response was obtained. The other example is based on real data from panel
sampling, where in four consecutive months there are corresponding four
attempts to interview each member in a panel. The sampling probabilities are
estimated based on the number of successful attempts.
  We also discuss briefly, further applications of deconvolution, including
estimation of False discovery rate.


title: Square-Free Shuffles of Words

abstract:
  Let $u \shuffle v$ denote the set of all shuffles of the words $u$ and $v$.
It is shown that for each integer $n \geq 3$ there exists a square-free ternary
word $u$ of length $n$ such that $u\shuffle u$ contains a square-free word.
This property is then shown to also hold for infinite words, i.e., there exists
an infinite square-free word $u$ on three letters such that $u$ can be shuffled
with itself to produce an infinite square-free word $w \in u \shuffle u$.


title: On the Complexity of Computing Critical Points with Gr\"obner Bases

abstract:
  Computing the critical points of a polynomial function $q\in\mathbb
Q[X_1,\ldots,X_n]$ restricted to the vanishing locus $V\subset\mathbb R^n$ of
polynomials $f_1,\ldots, f_p\in\mathbb Q[X_1,\ldots, X_n]$ is of first
importance in several applications in optimization and in real algebraic
geometry. These points are solutions of a highly structured system of
multivariate polynomial equations involving maximal minors of a Jacobian
matrix. We investigate the complexity of solving this problem by using
Gr\"obner basis algorithms under genericity assumptions on the coefficients of
the input polynomials. The main results refine known complexity bounds (which
depend on the maximum $D=\max(deg(f_1),\ldots,deg(f_p),deg(q))$) to bounds
which depend on the list of degrees $(deg(f_1),\ldots,deg(f_p),deg(q))$: we
prove that the Gr\"obner basis computation can be performed in
$\delta^{O(\log(A)/\log(G))}$ arithmetic operations in $\mathbb Q$, where
$\delta$ is the algebraic degree of the ideal vanishing on the critical points,
and $A$ and $G$ are the arithmetic and geometric average of a multiset
constructed from the sequence of degrees. As a by-product, we prove that
solving such generic optimization problems with Gr\"obner bases requires at
most $D^{O(n)}$ arithmetic operations in $\mathbb Q$, which meets the best
known complexity bound for this problem. Finally, we illustrate these
complexity results with experiments, giving evidence that these bounds are
relevant for applications.


title:
Frequency and time domain packet scheduling based on channel prediction
  with imperfect CQI in LTE

abstract:
  Channel-dependent scheduling of transmission of data packets in a wireless
system is based on measurement and feedback of the channel quality. To
alleviate the performance degradation due to simultaneous multiple imperfect
channel quality information (CQI), a simple and efficient packet scheduling
(PS) algorithm is developed in downlink LTE system for real time traffic. A
frequency domain channel predictor based on Kalman filter is first developed to
restore the true CQI from erroneous channel quality feedback. Then, a time
domain grouping technique employing the joint of Proportional Fair (PF) and
Modified Largest Weighted Delay First (M-LWDF) algorithms is used. It was
proved this proposal achieves better performance in terms of system throughput
and packet loss ratio by simulation results.