title:
Singular vanishing-viscosity limits of gradient flows: the
  finite-dimensional case

abstract:
  In this note we study the singular vanishing-viscosity limit of a gradient
flow set in a finite-dimensional Hilbert space and driven by a smooth, but
possibly non convex, time-dependent energy functional. We resort to ideas and
techniques from the variational approach to gradient flows and rate-independent
evolution to show that, under suitable assumptions, the solutions to the
singularly perturbed problem converge to a curve of stationary points of the
energy, whose behavior at jump points is characterized in terms of the notion
of Dissipative Viscosity solution. We also provide sufficient conditions under
which Dissipative Viscosity solutions enjoy better properties, which turn them
into Balanced Viscosity solutions. Finally, we discuss the generic character of
our assumptions.


title:
Nonperturbative renormalization group for scalar fields in de Sitter
  space: beyond the local potential approximation

abstract:
  Nonperturbative renormalization group techniques have recently proven a
powerful tool to tackle the nontrivial infrared dynamics of light scalar fields
in de Sitter space. In the present article, we develop the formalism beyond the
local potential approximation employed in earlier works. In particular, we
consider the derivative expansion, a systematic expansion in powers of field
derivatives, appropriate for long wavelength modes, that we generalize to the
relevant case of a curved metric with Lorentzian signature. The method is
illustrated with a detailed discussion of the so-called local potential
approximation prime which, on top of the full effective potential, includes a
running (but field-independent) field renormalization. We explicitly compute
the associated anomalous dimension for O(N) theories. We find that it can take
large values along the flow, leading to sizable differences as compared to the
local potential approximation. However, it does not prevent the phenomenon of
gravitationally induced dimensional reduction pointed out in previous studies.
We show that, as a consequence, the effective potential at the end of the flow
is unchanged as compared to the local potential approximation, the main effect
of the running anomalous dimension being merely to slow down the flow.


title:
Automatically Building Face Datasets of New Domains from Weakly Labeled
  Data with Pretrained Models

abstract:
  Training data are critical in face recognition systems. However, labeling a
large scale face data for a particular domain is very tedious. In this paper,
we propose a method to automatically and incrementally construct datasets from
massive weakly labeled data of the target domain which are readily available on
the Internet under the help of a pretrained face model. More specifically,
given a large scale weakly labeled dataset in which each face image is
associated with a label, i.e. the name of an identity, we create a graph for
each identity with edges linking matched faces verified by the existing model
under a tight threshold. Then we use the maximal subgraph as the cleaned data
for that identity. With the cleaned dataset, we update the existing face model
and use the new model to filter the original dataset to get a larger cleaned
dataset. We collect a large weakly labeled dataset containing 530,560 Asian
face images of 7,962 identities from the Internet, which will be published for
the study of face recognition. By running the filtering process, we obtain a
cleaned datasets (99.7+% purity) of size 223,767 (recall 70.9%). On our testing
dataset of Asian faces, the model trained by the cleaned dataset achieves
recognition rate 93.1%, which obviously outperforms the model trained by the
public dataset CASIA whose recognition rate is 85.9%.


title: Dynamic Key-Value Memory Networks for Knowledge Tracing

abstract:
  Knowledge Tracing (KT) is a task of tracing evolving knowledge state of
students with respect to one or more concepts as they engage in a sequence of
learning activities. One important purpose of KT is to personalize the practice
sequence to help students learn knowledge concepts efficiently. However,
existing methods such as Bayesian Knowledge Tracing and Deep Knowledge Tracing
either model knowledge state for each predefined concept separately or fail to
pinpoint exactly which concepts a student is good at or unfamiliar with. To
solve these problems, this work introduces a new model called Dynamic Key-Value
Memory Networks (DKVMN) that can exploit the relationships between underlying
concepts and directly output a student's mastery level of each concept. Unlike
standard memory-augmented neural networks that facilitate a single memory
matrix or two static memory matrices, our model has one static matrix called
key, which stores the knowledge concepts and the other dynamic matrix called
value, which stores and updates the mastery levels of corresponding concepts.
Experiments show that our model consistently outperforms the state-of-the-art
model in a range of KT datasets. Moreover, the DKVMN model can automatically
discover underlying concepts of exercises typically performed by human
annotations and depict the changing knowledge state of a student.


title: Surface theorem for the Chern-Simons axion coupling

abstract:
  The Chern-Simons axion coupling of a bulk insulator is only defined modulo a
quantum of e^2/h. The quantized part of the coupling is uniquely defined for a
bounded insulating sample, but it depends on the specific surface termination.
Working in a slab geometry and representing the valence bands in terms of
hybrid Wannier functions, we show how to determine that quantized part from the
excess Chern number of the hybrid Wannier sheets located near the surface of
the slab. The procedure is illustrated for a tight-binding model consisting of
coupled quantum anomalous Hall layers. By slowly modulating the model
parameters, it is possible to transfer one unit of Chern number from the bottom
to the top surface over the course of a cyclic evolution of the bulk
Hamiltonian. When the evolution of the surface Hamiltonian is also cyclic, the
Chern pumping is obstructed by chiral touchings between valence and conduction
surface bands.


title: Search for Ultra-High Energy Photons with the Pierre Auger Observatory

abstract:
  The Pierre Auger Observatory, located in Argentina, provides an unprecedented
integrated aperture for the search of photons with energy above 100 PeV. In
this contribution recent results are presented including the diffuse search for
photons and the directional search for photon point sources. The derived limits
are of considerable astrophysical interest: Diffuse limits place severe
constraints on top-down models and start to touch the predicted GZK photon flux
range while directional limits can exclude the continuation of the
electromagnetic flux from measured TeV sources with a significance of more than
5$\sigma$. Finally, prospects of neutral particle searches for the upcoming
detector upgrade AugerPrime are highlighted.


title: Revisiting a classic: the Parker-Moffatt problem

abstract:
  The interaction of two colliding Alfv\'en wave packets is here described by
means of magnetohydrodynamics (MHD) and hybrid kinetic numerical simulations.
The MHD evolution revisits the theoretical insights described by Moffatt,
Parker, Kraichnan, Chandrasekhar and Els\"asser in which the oppositely
propagating large amplitude wave packets interact for a finite time, initiating
turbulence. However, the extension to include compressive and kinetic effects,
while maintaining the gross characteristics of the simpler classic formulation,
also reveals intriguing features which go beyond the pure MHD treatment.


title:
Nontrivial Berry phase and type II Dirac transport in layered material
  PdTe2

abstract:
  Here we report the evidence of the type II Dirac Fermion in the layered
crystal PdTe2. The de Haas-van Alphen oscillations find a small Fermi pocket
with a cross section of 0.077nm-2 with a nontrivial Berry phase.
First-principal calculations reveal that it is originated from the hole pocket
of a tilted Dirac cone. Angle Resolved Photoemission Spectroscopy demonstrates
a type II Dirac cone featured dispersion. We also suggest PdTe2 is an improved
platform to host the topological superconductors.


title: Global bifurcations of limit cycles in the Kukles cubic system

abstract:
  In this paper, using our bifurcational geometric approach, we solve the
problem on the maximum number and distribution of limit cycles in the Kukles
system representing a planar polynomial dynamical system with arbitrary linear
and cubic right-hand sides and having an anti-saddle at the origin. We also
apply alternatively the Wintner-Perko termination principle to solve this
problem.


title: In-situ Atom Probe Deintercalation of Lithium-Manganese-Oxide

abstract:
  Atom probe tomography is routinely used for the characterisation of materials
microstructures usually assuming that the microstructure is unaltered by the
analysis. When analysing ionic conductors, however, gradients in the chemical
potential and the electric field penetrating dielectric atom probe specimens
can cause significant ionic mobility. While ionic mobility is undesired when
aiming for materials characterisation it offers a strategy to manipulate
materials directly in-situ in the atom probe. Here, we present experimental
results on the analysis of the ionic conductor Lithium-Manganese-Oxide with
different atom probe techniques. We demonstrate that at a temperature of 30K
characterisation of the materials microstructure is possible without measurable
Li mobility. Contrary, we show that at 298K the material can be deintercalated
in-situ in the atom probe without changing the Manganese-Oxide host structure.
Combining in-situ atom probe deintercalation and subsequent conventional
characterisation we demonstrate a new methodological approach to study ionic
conductors even in early stages of deintercalation.


title:
Accessing Generalized Parton Distributions in Exclusive Photoproduction
  of a $\gamma \rho$ Pair with a Large Invariant Mass

abstract:
  We propose and study the photoproduction of a $\gamma\,\rho$ pair with a
large invariant mass and a small transverse momentum of the final nucleon, as a
way to access generalized parton distributions. In the kinematics of JLab
12-GeV, we demonstrate the feasibility of this measurement.


title:
Effect of surface state hybridization on current-induced spin-orbit
  torque in thin topological insulator films

abstract:
  We investigate the current-induced spin-orbit torque in thin topological
insulator (TI) films in the presence of hybridization between the top and
bottom surface states. We formulate the relation between spin torque and TI
thickness, from which we derived the optimal value of the thickness to maximize
the torque. We show numerically that in typical TI thin films made of
$\mathrm{Bi_2Se_3}$, the optimal thickness is about 3-5 nm.


title: The condition number of join decompositions

abstract:
  The join set of a finite collection of smooth embedded submanifolds of a
mutual vector space is defined as their Minkowski sum. Join decompositions
generalize some ubiquitous decompositions in multilinear algebra, namely tensor
rank, Waring, partially symmetric rank and block term decompositions. This
paper examines the numerical sensitivity of join decompositions to
perturbations; specifically, we consider the condition number for general join
decompositions. It is characterized as a distance to a set of ill-posed points
in a supplementary product of Grassmannians. We prove that this condition
number can be computed efficiently as the smallest singular value of an
auxiliary matrix. For some special join sets, we characterized the behavior of
sequences in the join set converging to the latter's boundary points. Finally,
we specialize our discussion to the tensor rank and Waring decompositions and
provide several numerical experiments confirming the key results.


title:
BayesVarSel: Bayesian Testing, Variable Selection and model averaging in
  Linear Models using R

abstract:
  This paper introduces the R package BayesVarSel which implements objective
Bayesian methodology for hypothesis testing and variable selection in linear
models. The package computes posterior probabilities of the competing
hypotheses/models and provides a suite of tools, specifically proposed in the
literature, to properly summarize the results. Additionally, \ourpack\ is armed
with functions to compute several types of model averaging estimations and
predictions with weights given by the posterior probabilities. BayesVarSel
contains exact algorithms to perform fast computations in problems of small to
moderate size and heuristic sampling methods to solve large problems. The
software is intended to appeal to a broad spectrum of users, so the interface
has been carefully designed to be highly intuititive and is inspired by the
well-known lm function. The issue of prior inputs is carefully addressed. In
the default usage (fully automatic for the user)BayesVarSel implements the
criteria-based priors proposed by Bayarri et al (2012), but the advanced user
has the possibility of using several other popular priors in the literature.
The package is available through the Comprehensive R Archive Network, CRAN. We
illustrate the use of BayesVarSel with several data examples.


title: Heavy Higgs boson production and decay into top quarks at the LHC

abstract:
  In this contribution we report on the calculation of the next-to-leading
order (NLO) QCD corrections to the hadro-production of heavy neutral Higgs
bosons and their decay into top-quark pairs within the type-II
two-Higgs-doublet extension of the standard model (SM). We take into account
the contributions from resonant Higgs boson production, the non-resonant SM
$t\bar{t}$ background as well as the interference of these two contributions.
The NLO corrections to the signal and interference contributions are calculated
by applying the heavy top-quark mass ($m_t$) limit including an effective
rescaling. In our NLO calculation the QCD-Higgs interference is evaluated in
the resonance region that provides the dominant part of the heavy Higgs-boson
contributions. Evaluating representative $CP$-conserving and $CP$-violating
parameter scenarios within the two-Higgs-doublet model (2HDM) we present
results for different distributions and, in addition, for observables that
depend on the top-quark spin.


title: Optimal Codes from Fibonacci Polynomials and Secret Sharing Schemes

abstract:
  In this work, we study cyclic codes that have generators as Fibonacci
polynomials over finite fields. We show that these cyclic codes in most cases
produce families of maximum distance separable and optimal codes with
interesting properties. We explore these relations and present some examples.
Also, we present applications of these codes to secret sharing schemes.


title:
Impact Factor for Exclusive Diffractive Dijet Production with NLO
  Accuracy

abstract:
  Relying on the shockwave approach, we present the main steps of the
computation of the impact factor for the exclusive diffractive photo- or
electro- production of a forward dijet with NLO accuracy. We provide details of
the cancellation mechanisms for all the divergences which appear in the
intermediate results.


title:
Parallelization of continuous and discontinuous Galerkin dual-primal
  Isogeometric tearing and interconnecting methods

abstract:
  In this paper we investigate the parallelization of dual-primal isogeometric
tearing and interconnecting (IETI-DP) type methods for solving large-scale
continuous and discontinuous Galerkin systems of equations arising from
Isogeometric analysis of elliptic boundary value problems. These methods are
extensions of the finite element tearing and interconnecting methods to
isogeometric analysis. The algorithms are implemented by means of energy
minimizing primal subspaces. We discuss how these methods can efficiently be
parallelized in a distributed memory setting. Weak and strong scaling studies
presented for two and three dimensional problems show an excellent parallel
efficiency.


title: Noninvasive Measurement of Dynamic Correlation Functions

abstract:
  The measurement of dynamic correlation functions of quantum systems is
complicated by measurement backaction. To facilitate such measurements we
introduce a protocol, based on weak ancilla--system couplings, that is
applicable to arbitrary (pseudo)spin systems and arbitrary equilibrium or
nonequilibrium initial states. Different choices of the coupling operator give
access to the real and imaginary parts of the dynamic correlation function.
This protocol reduces disturbances due to the early time measurements to a
minimum, and we quantify the deviation of the measured correlation functions
from the theoretical, unitarily-evolved ones. Implementations of the protocol
in trapped ions and other experimental platforms are discussed. For spin-$1/2$
models and single-site observables we prove that measurement backaction can be
avoided altogether, allowing for the use of ancilla-free protocols.


title:
H\"{o}lder Continuous Periodic Solution of Boussinesq Equation with
  Partial Viscosity

abstract:
  We show the existence of H\"older continuous periodic solution with compact
support in time of the Boussinesq equations with partial viscosity. The
H\"older regularity of the solution we constructed is anisotropic which is
compatible with partial viscosity of the equations.


title: Axial Hall effect and universality of holographic Weyl semi-metals

abstract:
  The holographic Weyl semimetal is a model of a strongly coupled topological
semi-metal. A topological quantum phase transition separates a topological
phase with non-vanishing anomalous Hall conductivity from a trivial state. We
investigate how this phase transition depends on the parameters of the scalar
potential (mass and quartic self coupling) finding that the quantum phase
transition persists for a large region in parameter space. We then compute the
axial Hall conductivity. The algebraic structure of the axial anomaly predicts
it to be 1/3 of the electric Hall conductivity. We find that this holds once a
non-trivial renormalization effect on the external axial gauge fields is taken
into account. Finally we show that the phase transition also occurs in a
top-down model based on a consistent truncation of type IIB supergravity.


title: On mixed joint discrete universality for a class of zeta-functions

abstract:
  We prove a mixed joint discrete universality theorem for a Matsumoto
zeta-function $\varphi(s)$ (belonging to the Steuding subclass) and a periodic
Hurwitz zeta-function $\zeta(s,\alpha;{\mathfrak{B}})$. For this purpose,
certain independence condition for the parameter $\alpha$ and the minimal step
of discrete shifts of these functions is assumed. This paper is a continuation
of authors' works [12] and [arXiv:1601.03795].


title: Coupling DG-FEM and BEM for time harmonic eddy current problem

abstract:
  We introduce and analyze a discontinuous Galerkin FEM/BEM method for a
time-harmonic eddy current problem written in terms of the magnetic field. We
use nonconforming N\'ed\'elec finite elements on a partition of the interior
domain coupled with continuous boundary elements on the transmission interface.
We prove quasi-optimal error estimates in the energy norm.


title: On the distribution of polynomials with bounded height

abstract:
  We provide an asymptotic expression for the probability that a randomly
chosen polynomial with given degree, having integral coefficients bounded by
some B, has a prescribed signature. We also give certain related formulas and
numerical results along this line. Our theorems are closely related to earlier
results of Akiyama and Peth\H{o}, and also yield extensions of recent results
of Dubickas and Sha.


title:
Substrate Induced Molecular Conformations in Rubrene Thin Films: A
  Thickness Dependent Study

abstract:
  A systematic experimental and theoretical study about substrate induced
molecular conformation in rubrene thin films by varying film thickness from
sub-monolayer to multilayer, which currently attracts substantial attention
with regard to its application in organic electronics, is performed. The clean
polycrystalline Au and Ag were used as noble-metals, whereas, H passivated and
SiO2 terminated Si (100) were used as dielectric substrates. Angle dependent
near edge x-ray absorption fine structure spectroscopy (NEXAFS) was employed to
understand the molecular conformation whereas atomic force microscopy (AFM) was
used to investigate the surface morphologies of the films. X-ray absorption
spectra (XAS) of rubrene molecules with flat and twisted conformations were
calculated using density functional theory (DFT). All the observed NEXAFS
spectra of rubrene thin films at various thicknesses and onto different
substrates were explained in terms of different combination of the spectral
intensity from the twisted and the flat molecules. In contrast to general
findings, comparatively rough polycrystalline Ag surface is found to support
growth of better quality rubrene films. The results have important implications
for the understanding of the substrate induced molecular conformations in
rubrene thin films with its thickness and are beneficial for the improvement of
the device performance.


title: Influence of broken flavor and C and P symmetry on the quark propagator

abstract:
  Embedding QCD into the standard model breaks various symmetries of QCD
explicitly, especially C and P. While these effects are usually perturbatively
small, they can be amplified in extreme environments like merging neutron stars
or by the interplay with new physics. To correctly treat these cases requires
fully backcoupled calculations. To pave the way for later investigations of
hadronic physics, we study the QCD quark propagator coupled to an explicit
breaking. This substantially increases the tensor structure even for this
simplest correlation function. To cope with the symmetry structure, and
covering all possible quark masses, from the top quark mass to the chiral
limit, we employ Dyson-Schwinger equations. While at weak breaking the
qualitative effects have similar trends as in perturbation theory, even
moderately strong breakings lead to qualitatively different effects,
non-linearly amplified by the strong interactions.


title:
Extraction of airway trees using multiple hypothesis tracking and
  template matching

abstract:
  Knowledge of airway tree morphology has important clinical applications in
diagnosis of chronic obstructive pulmonary disease. We present an automatic
tree extraction method based on multiple hypothesis tracking and template
matching for this purpose and evaluate its performance on chest CT images. The
method is adapted from a semi-automatic method devised for vessel segmentation.
Idealized tubular templates are constructed that match airway probability
obtained from a trained classifier and ranked based on their relative
significance. Several such regularly spaced templates form the local hypotheses
used in constructing a multiple hypothesis tree, which is then traversed to
reach decisions. The proposed modifications remove the need for local
thresholding of hypotheses as decisions are made entirely based on statistical
comparisons involving the hypothesis tree. The results show improvements in
performance when compared to the original method and region growing on
intensity images. We also compare the method with region growing on the
probability images, where the presented method does not show substantial
improvement, but we expect it to be less sensitive to local anomalies in the
data.


title: Large deviations in Taylor dispersion

abstract:
  We establish a link between the phenomenon of Taylor dispersion and the
theory of empirical distributions. Using this connection, we derive, upon
applying the theory of large deviations, an alternative and much more precise
description of the long-time regime for Taylor dispersion.


title: Effects of QCD bound states on dark matter relic abundance

abstract:
  We study scenarios where there exists an exotic massive particle charged
under QCD in the early Universe. We calculate the formation and dissociation
rates of bound states formed by pairs of these particles, and apply the results
in dark matter (DM) coannihilation scenarios, including also the Sommerfeld
effect. We find that on top of the Sommerfeld enhancement, bound-state effects
can further significantly increase the largest possible DM masses which can
give the observed DM relic abundance, by $\sim 30 - 100\%$ with respect to
values obtained by considering the Sommerfeld effect only, for the color
triplet or octet exotic particles we consider. In particular, it indicates that
the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the
Minimal Supersymmetric extension of the Standard Model (MSSM) can reach $\sim
2.5$ TeV, even though the potential between the stop and antistop prior to
forming a bound state is repulsive. We also apply the bound-state effects in
the calculations of relic abundance of long-lived or metastable massive colored
particles, and discuss the implications on the BBN constraints and the
abundance of a super-weakly interacting DM. The corrections for the bound-state
effect when the exotic massive colored particles also carry electric charges,
and the collider bounds are also discussed.


title: Comparative study of histogram distance measures for re-identification

abstract:
  Color based re-identification methods usually rely on a distance function to
measure the similarity between individuals. In this paper we study the behavior
of several histogram distance measures in different color spaces. We wonder
whether there is a particular histogram distance measure better than others,
likewise also, if there is a color space that present better discrimination
features. Several experiments are designed and evaluated in several images to
obtain measures against various color spaces. We test in several image
databases. A measure ranking is generated to calculate the area under the CMC,
this area is the indicator used to evaluate which distance measure and color
space present the best performance for the considered databases. Also, other
parameters such as the image division in horizontal stripes and number of
histogram bins, have been studied.


title:
Question Retrieval for Community-based Question Answering via
  Heterogeneous Network Integration Learning

abstract:
  Community based question answering platforms have attracted substantial users
to share knowledge and learn from each other. As the rapid enlargement of CQA
platforms, quantities of overlapped questions emerge, which makes users
confounded to select a proper reference. It is urgent for us to take effective
automated algorithms to reuse historical questions with corresponding answers.
In this paper we focus on the problem with question retrieval, which aims to
match historical questions that are relevant or semantically equivalent to
resolve one s query directly. The challenges in this task are the lexical gaps
between questions for the word ambiguity and word mismatch problem.
Furthermore, limited words in queried sentences cause sparsity of word
features. To alleviate these challenges, we propose a novel framework named
HNIL which encodes not only the question contents but also the askers social
interactions to enhance the question embedding performance. More specifically,
we apply random walk based learning method with recurrent neural network to
match the similarities between askers question and historical questions
proposed by other users. Extensive experiments on a large scale dataset from a
real world CQA site show that employing the heterogeneous social network
information outperforms the other state of the art solutions in this task.


title:
Vorticity in the QGP liquid and hyperon polarization at the RHIC BES
  energies

abstract:
  We calculate the polarization of $\Lambda$ hyperons in Au-Au collisions at
RHIC Beam Energy Scan range $\sqrt{s_{\rm NN}}=7.7, \dots, 200$ GeV in a
state-of-the-art 3+1 dimensional cascade + viscous hydro model vHLLE+UrQMD. We
find that the polarization of $\Lambda$ in the out-of-plane direction decreases
substantially with collision energy. We explore the connection between the
polarization signal and thermal vorticity and discuss the feed-down and
hadronic rescattering effects on the mean polarization of all produced
$\Lambda$ hyperons.


title:
A note for some parabolic multilinear commutators generated by a class
  of parabolic maximal and linear operators with rough kernel on the parabolic
  generalized local Morrey spaces

abstract:
  In this paper, we give the boundedness of some parabolic multilinear
commutators generated by a class of parabolic maximal and linear operators with
rough kernel and parabolic local Campanato functions on the parabolic
generalized local Morrey spaces, respectively. Indeed, the results in this
paper are extensions of some known results.


title:
Solutions of the Yang-Baxter equation associated to skew left braces,
  with applications to racks

abstract:
  Given a skew left brace $B$, a method is given to construct all the
non-degenerate set-theoretic solutions $(X,r)$ of the Yang Baxter equation such
that the associated permutation group $\mathcal{G}(X,r)$ is isomorphic, as a
skew left brace, to $B$. This method depends entirely on the brace structure of
$B$. We then adapt this method to show how to construct solutions with
additional properties, like square-free, involutive or irretractable solutions.
Using this result, it is even possible to recover racks from their permutation
group.


title: Torsion pairs in silting theory

abstract:
  In the setting of compactly generated triangulated categories, we show that
the heart of a (co)silting t-structure is a Grothendieck category if and only
if the (co)silting object satisfies a purity assumption. Moreover, in the
cosilting case the previous conditions are related to the coaisle of the
t-structure being a definable subcategory. If we further assume our
triangulated category to be algebraic, it follows that the heart of any
nondegenerate compactly generated t-structure is a Grothendieck category.


title: Cichon's Diagram for uncountable cardinals

abstract:
  We develop a version of Cichon's diagram for cardinal invariants on the
generalized Cantor space 2^kappa or the generalized Baire space kappa^kappa
where kappa is an uncountable regular cardinal. For strongly inaccessible
kappa, many of the ZFC-results about the order relationship of the cardinal
invariants which hold for omega generalize; for example we obtain a natural
generalization of the Bartoszynski-Raisonnier-Stern Theorem. We also prove a
number of independence results, both with <kappa-support iterations and
kappa-support iterations and products, showing that we consistently have strict
inequality between some of the cardinal invariants.


title:
Mean-field energy-level shifts and dielectric properties of strongly
  polarized Rydberg gases

abstract:
  Mean-field energy-level shifts arising as a result of strong electrostatic
dipole interactions within dilute gases of polarized helium Rydberg atoms have
been probed by microwave spectroscopy. The Rydberg states studied had principal
quantum numbers $n=70$ and 72, and electric dipole moments of up to 14050 D,
and were prepared in pulsed supersonic beams at particle number densities on
the order of $10^{8}$ cm$^{-3}$. Comparisons of the experimental data with the
results of Monte Carlo calculations highlight effects of the distribution of
nearest-neighbor spacings in the pulsed supersonic beams, and the dielectric
properties of the strongly polarized Rydberg gases, on the microwave spectra.
These observations reflect the emergence of macroscopic electrical properties
of the atomic samples when strongly polarized.


title:
On the effect of ocean tides and tesseral harmonics on spacecraft flybys
  of the Earth

abstract:
  The so-called flyby anomaly has encouraged several authors to analyze in
detail the minor perturbative contributions to the trajectory of spacecraft
performing a flyby manoeuvre. This anomaly consist of an unexplained increase
or decrease of the asymptotic velocity of the spacecraft after a flyby of the
Earth in the range of a few mm per second. Some order of magnitude estimations
have been performed in recent years to dismiss many possible conventional
effects as the source of such an anomaly but no explanation has been found yet.
In this paper we perform a study of the perturbation induced by ocean tides in
a flybying spacecraft by considering the time dependence of the location of the
high tide as the Moon follows its orbit. We show that this effect implies a
change of the spacecraft velocity of a few micrometers per second.
  We also consider the coupling of tesseral harmonics inhomogeneities and the
rotation of the Earth and its impact of the spacecraft outgoing velocity.
Significant corrections to the observed asymptotic velocities are found in this
case but neither their sign nor their magnitude coincide with the anomalies.
So, we can also rule this out as a conventional explanation.


title: Cofinalities of Marczewski-like ideals

abstract:
  We show that the cofinalities of both the Miller ideal m^0 (the sigma-ideal
naturally related to Miller forcing) and the Laver ideal ell^0 (related to
Laver forcing) are larger than the size of the continuum in ZFC.


title:
How I Stopped Worrying about the Twitter Archive at the Library of
  Congress and Learned to Build a Little One for Myself

abstract:
  Twitter is among the commonest sources of data employed in social media
research mainly because of its convenient APIs to collect tweets. However, most
researchers do not have access to the expensive Firehose and Twitter Historical
Archive, and they must rely on data collected with free APIs whose
representativeness has been questioned. In 2010 the Library of Congress
announced an agreement with Twitter to provide researchers access to the whole
Twitter Archive. However, such a task proved to be daunting and, at the moment
of this writing, no researcher has had the opportunity to access such
materials. Still, there have been experiences that proved that smaller
searchable archives are feasible and, therefore, amenable for academics to
build with relatively little resources. In this paper I describe my efforts to
build one of such archives, covering the first three years of Twitter (actually
from March 2006 to July 2009) and containing 1.48 billion tweets. If you
carefully follow my directions you may have your very own little Twitter
Historical Archive and you may forget about paying for historical tweets.
Please note that to achieve that you should be proficient in some programming
language, knowable about Twitter APIs, and have some basic knowledge on
ElasticSearch; moreover, you may very well get disappointed by the quality of
the contents of the final dataset.


title: Estimating Causal Effects From Nonparanormal Observational Data

abstract:
  One of the basic aims in science is to unravel the chain of cause and effect
of particular systems. Especially for large systems this can be a daunting
task. Detailed interventional and randomized data sampling approaches can be
used to resolve the causality question, but for many systems such interventions
are impossible or too costly to obtain. Recently, Maathuis et al. (2010),
following ideas from Spirtes et al. (2000), introduced a framework to estimate
causal effects in large scale Gaussian systems. By describing the causal
network as a directed acyclic graph it is a possible to estimate a class of
Markov equivalent systems that describe the underlying causal interactions
consistently, even for non-Gaussian systems. In these systems, causal effects
stop being linear and cannot be described any more by a single coefficient. In
this paper, we derive the general functional form of causal effect in a large
subclass of non-Gaussian distributions, called the non- paranormal. We also
derive a convenient approximation, which can be used effectively in estimation.
We apply the method to an observational gene expression dataset.


title:
Optical Schr\"odinger Cat States in One Mode and two Coupled-Modes
  Subject to Environments

abstract:
  Taking the decoherence into account, we investigate nonclassical features of
the optical Schr\"odinger cat states in one mode and two coupled-modes systems
with two-photon driving. In the one mode system, the relationship between the
Schr\"odinger cat states and the system parameters is derived. We observe that
in the presence of single-photon decay the steady states would be a mixture of
Schr\"odinger cats. The dynamics and steady states of such a cat versus
single-photon decay are examined. In the two coupled-modes cases with linear
and nonlinear couplings, the dynamics of entanglement and mutual information
are examined with two different initial states and single-photon decay.
Compared to the linear coupling case, more complicated structure appears in the
Wigner function in the nonlinear coupling case. The joint quadrature
distributions are also explored. Such nonclassical states can be used not only
in exploring the boundary between the classical and the quantum worlds but also
in quantum metrology and quantum information processing.


title: Deformation of $\mathfrak{osp}(2|2)$-Modules of Symbols

abstract:
  We classify deformations of $\mathfrak{osp}(2|2)-$module structure on the
spaces of symbols $\mathfrak{S}_d^2$ of differential operators acting on the
space of weighted densities $\mathfrak{F}_{\lambda}^{2}$.


title:
Thermophysical and magnetic properties of p- and n-type Ti-Ni-Sn based
  half-Heusler alloys

abstract:
  A total of 5 different half-Heusler alloys, two p-type and two n-type with
the fifth a charge compensated alloy have been designed and synthesized. The
thermophysical properties of these alloys have been investigated in the range
10 K to 1000 K while the magnetic behavior has been studied up to 300 K. The
electrical resistivity of all the alloys varies within the range 0.06 to 5
m{\Omega} cm indicating that they are in the degenerate semiconductor limits.
The temperature dependence of p-type alloys exhibits a transition from metallic
to semiconducting behavior, typical of topological insulators. The transition
is found to occur in the range 300 K to 500 K. The n-type and compensated
alloys exhibit a weak metallic behavior in the complete temperature range. The
Seebeck coefficient in the p-type alloys increases with temperature reaching a
maximum value of 50 microV K-1 while that of the n-type alloys increases
continuously reaching a value of 45 microV K-1 at ~ 800 K. The corresponding
power factor of the n-type alloy reaches 900 microW m-1 K-2 at ~ 900 K compared
to a maximum of ~ 250 microW m-1 K-2 at 700 K for the p-type alloy.
Magnetically the p-type and n-type alloys are found to be paramagnetic while
the compensated alloy exhibits a ferromagnetic behavior.


title: Double quarkonium production at high Feynman-$x$

abstract:
  In this paper we give estimates for the proton--proton cross sections into
pairs of quarkonium states $J/\psi$, $\psi(2S)$, $\Upsilon(1S)$ and
$\Upsilon(2S)$ at the scheduled AFTER@LHC energy of $115$GeV. The estimates are
based on the intrinsic heavy flavor mechanism which is observable for high
values of $x_F$, a range outside the dominance of single parton and double
parton scattering.


title: Maximal trees

abstract:
  We show that, consistently, there can be maximal subtrees of P (omega) and P
(omega) / fin of arbitrary regular uncountable size below the size of the
continuum. We also show that there are no maximal subtrees of P (omega) / fin
with countable levels. Our results answer several questions of Campero,
Cancino, Hrusak, and Miranda.


title:
Insight into dielectric response of ferroelectric relaxors by
  statistical modeling

abstract:
  Ferroelectric relaxors are complex materials with distinct properties. The
understanding of their dielectric susceptibility, which strongly depends on
both temperature and probing frequency, have interested researchers for many
years. Here we report a macroscopic and phenomenological approach based on
statistical modeling to investigate and better understand how the dielectric
response of a relaxor depends on temperature. Employing the Maxwell-Boltzmann
distribution and considering temperature dependent dipolar orientational
polarizability, we propose a minimum statistical model and specific equations
to understand and fit numerical and experimental dielectric responses versus
temperature. We show that the proposed formula can successfully fit the
dielectric response of typical relaxors, including Ba(Zr,Ti)O$_{3}$,
Pb(Zn$_{1/3}$Nb$_{2/3}$)$_{0.87}$Ti$_{0.13}$O$_{3}$, and
Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-0.05Pb(Zr$_{0.53}$Ti$_{0.47}$)O$_{3}$, which
demonstrates the general applicability of this approach.


title: Q

abstract:
  A Q-set is an uncountable set of reals all of whose subsets are relative
$G_\delta$ sets. We prove that, for an arbitrary uncountable cardinal kappa,
there is consistently a Q-set of size $\kappa$ whose square is not Q. This
answers a question of A. Miller.


title:
Magnetic behavior of Ni substituted LiCoO2, magnetization and electron
  paramagnetic resonance studies

abstract:
  Single phase Ni substituted LiCo1-xNixO2 solid solutions with x < 0.15 have
been synthesized to study the effect of substitution on the magnetic behavior.
Two different techniques, magnetic susceptibility and electron paramagnetic
resonance, EPR which provide information in two different time windows have
been used. The solid solutions have been found to be single phase with large
grains conforming to R-3m rhombohedral structure. The lattice parameters c and
a increase with increasing Ni substitution but with a nearly constant c/a ratio
of about 4.99 in all the cases indicating that the CoO6 and LiO6 octahedra do
not undergo any Jahn-Teller distortions. The room temperature EPR absorption
spectra clearly shows a peak in all the compounds at a field of 314 mT
corresponding to a g-factor of 2.14. The peak width however is found to be a
strong function of Ni substitution; increasing with increasing Ni from 3.6 mT
to 6.5 mT for x = 0.08. The magnetization increases with decreasing temperature
in all the compounds, a paramagnetic behavior, unlike Li-deficient compounds
which show a Pauli paramagnetic susceptibility. Also, the magnetization
exhibits thermal irreversibility which vanishes at large magnetic fields in all
the compounds. The unsubstituted compound has discontinuities at 200 K and 50 K
corresponding to magnetic transitions which disappear on substitution with 2 %
Ni for Co. The effective magnetic moment is found to increase from 0.32 Bohr
magnetons to 0.66 Bohr magnetons on increasing the substitution to 0.15. The
unique feature however is that all the compounds exhibit a clear magnetic
hysteresis at room temperature with a finite coercivity. The coercivity
increases from 31 Oe to 168 Oe for x = 0.04 and then decreases on further
increasing of x. A deconvolution of the hysteresis loops clearly shows an
increasing paramagnetic component with substitution.


title:
AutoGain: Gain Function Adaptation with Submovement Efficiency
  Optimization

abstract:
  A well-designed control-to-display gain function can improve pointing
performance with indirect pointing devices like trackpads. However, the design
of gain functions is challenging and mostly based on trial and error. AutoGain
is a novel method to individualize a gain function for indirect pointing
devices in contexts where cursor trajectories can be tracked. It gradually
improves pointing efficiency by using a novel submovement-level
tracking+optimization technique that minimizes aiming error
(undershooting/overshooting) for each submovement. We first show that AutoGain
can produce, from scratch, gain functions with performance comparable to
commercial designs, in less than a half-hour of active use. Second, we
demonstrate AutoGain's applicability to emerging input devices (here, a Leap
Motion controller) with no reference gain functions. Third, a one-month
longitudinal study of normal computer use with AutoGain showed performance
improvements from participants' default functions.


title:
Argon assisted chemical vapor deposition of CrO$_2$: an efficient
  process leading to high quality epitaxial films

abstract:
  A comparative study of the structural, microstructural and magnetic
properties of CrO$_2$ thin films grown onto (110) and (100) TiO$_2$ rutile
single crystal substrates by chemical vapor deposition (CVD), using CrO$_3$ as
chromium precursor and either oxygen or argon as carrier gas is presented. Our
results show that growth under argon carrier gas leads to high quality CrO$_2$
epilayers with structural and magnetic properties similar to those obtained
using the more standard oxygen carrier gas. Furthermore, we interpret the
larger magnetic coercivity observed for the (110) oriented films in terms of
their microstructure, in particular of the highest strain and edge roughness of
the building structures of the CrO$_2$ epilayers, which are settled by the
substrate crystallographic orientation.


title: Fast diffusion of water nanodroplets on graphene

abstract:
  Diffusion across surfaces generally involves motion on a vibrating but
otherwise stationary substrate. Here, using molecular dynamics, we show that a
layered material such as graphene opens up a new mechanism for surface
diffusion whereby adsorbates are carried by propagating ripples via a motion
similar to surfing. For water nanodroplets, we demonstrate that the mechanism
leads to exceedingly fast diffusion that is 2-3 orders of magnitude faster than
the self-diffusion of water molecules in liquid water. We also reveal the
underlying principles that regulate this new mechanism for diffusion and show
how it also applies to adsorbates other than water, thus opening up the
prospect of achieving fast and controllable motion of adsorbates across
material surfaces more generally.


title: Three-body problem in 3D space: ground state, (quasi)-exact-solvability

abstract:
  We study aspects of the quantum and classical dynamics of a $3$-body system
in 3D space with interaction depending only on mutual distances. The study is
restricted to solutions in the space of relative motion which are functions of
mutual distances only. It is shown that the ground state (and some other
states) in the quantum case and the planar trajectories in the classical case
are of this type. The quantum (and classical) system for which these states are
eigenstates is found and its Hamiltonian is constructed. It corresponds to a
three-dimensional quantum particle moving in a curved space with special
metric. The kinetic energy of the system has a hidden $sl(4,R)$ Lie (Poisson)
algebra structure, alternatively, the hidden algebra $h^{(3)}$ typical for the
$H_3$ Calogero model. We find an exactly solvable three-body generalized
harmonic oscillator-type potential as well as a quasi-exactly-solvable
three-body sextic polynomial type potential; both models have an extra
integral.

categories: math-ph cond-mat.mes-hall math.MP math.SP physics.class-ph quant-ph


title: Control of three heat equations coupled with two cubic nonlinearities

abstract:
  We study the null controllability of three parabolic equations. The control
is acting only on one of the three equations. The three equations are coupled
by means of two cubic nonlinearities. The linearized control system around 0 is
not null controllable. However, using the cubic nonlinearities, we prove the
(global) null controllability of the control system. The proof relies on the
return method, an algebraic solvability and smoothing properties of the
parabolic equations.


title: The polarimetric multi-frequency radio sources properties

abstract:
  The polarization properties of extragalactic radio sources at frequencies
higher than 20 GHz are still poorly constrained. However, their
characterization would provide invaluable information about the physics of the
emission processes and is crucial to estimate their contamination as
foregrounds of the polarized cosmic microwave background (CMB) angular power
spectrum on scales < 30 arcmin. In this contribution, after summarizing the
state-of-the-art of polarimetric observations in the millimetric wavelength
bands, we present our observations of a complete sample of 53 sources with S >
200 mJy (at 20 GHz) carried out with the Australia Telescope Compact Array
between 5.5 and 38 GHz. The analysis clearly shows that polarization properties
cannot be simply inferred from total intensity ones, as the spectral behaviors
of the two signals are typically different.


title: The uniform quantized electron gas revisited

abstract:
  In this work we continue and extend our recent work on the correlation energy
of the quantized electron gas of uniform density at temperature $T=0$. As
before we utilize the methods, properties, and results obtained by means of
classical statistical mechanics. These were extended to quantized systems via
the Feynman path integral formalism. The latter translates the quantum problem
into a classical polymer problem in four dimensions. Again the well known RPA
(random phase approximation) is recovered as a basic result which we then
modify and improve upon. Here we will we focus upon thermodynamic
self-consistency. Our numerical calculations exhibit a remarkable agreement
with well known results of a standard parametrization of Monte Carlo
correlation energies.


title: One-dimensional stationary mean-field games with local coupling

abstract:
  A standard assumption in mean-field game (MFG) theory is that the coupling
between the Hamilton-Jacobi equation and the transport equation is
monotonically non-decreasing in the density of the population. In many cases,
this assumption implies the existence and uniqueness of solutions. Here, we
drop that assumption and construct explicit solutions for one-dimensional MFGs.
These solutions exhibit phenomena not present in monotonically increasing MFGs:
low-regularity, non-uniqueness, and the formation of regions with no agents.


title:
Velocity Dispersion of Correlated Energy Spread Electron Beams in the
  Free Electron Laser

abstract:
  The effects of a correlated linear energy/velocity chirp in the electron beam
in the FEL, and how to compensate for its effects by using an appropriate taper
(or reverse-taper) of the undulator magnetic field, is well known. The theory,
as described thus far, ignores velocity dispersion from the chirp in the
undulator, taking the limit of a `small' chirp. In the following, the physics
of compensating for chirp in the beam is revisited, including the effects of
velocity dispersion, or beam compression or decompression, in the undulator. It
is found that the limit of negligible velocity dispersion in the undulator is
different from that previously identified as the small chirp limit, and is more
significant than previously considered. The velocity dispersion requires a
taper which is non-linear to properly compensate for the effects of the
detuning, and also results in a varying peak current (end thus a varying gain
length) over the length of the undulator. The results may be especially
significant for plasma driven FELs and low energy linac driven FEL test
facilities.


title:
Diffusion-Weighted MR imaging: Clinical applications of kurtosis
  analysis to prostate cancer

abstract:
  Magnetic resonance imaging technique known as DWI (diffusion-weighted
imaging) allows measurement of water diffusivity on a pixel basis for
evaluating pathology throughout the body and is now routinely incorporated into
many body MRI protocols, mainly in oncology. Indeed water molecules motion
reflects the interactions with other molecules, membranes, cells, and in
general the interactions with the environment. Microstructural changes as e.g.
cellular organization and/or integrity then affect the motion of water
molecules, and consequently alter the water diffusion properties measured by
DWI. Then DWI technique can be used to extract information about tissue
organization at the cellular level indirectly from water motion. In general the
signal intensity in DWI can be quantified by using a parameter known as ADC
(Apparent Diffusion Coefficient) emphasizing that it is not the real diffusion
coefficient, which is a measure of the average water molecular motion. In the
simplest models, the distribu- tion of a water molecule diffusing in a certain
period of time is considered to have a Gaussian form with its width
proportional to the ADC. However, water in biological structures often displays
non-Gaussian diffusion behavior, consequently the DWI signal shows a more
complex behavior that need to be modeled following different approaches. In
this work we explore the possibility to quantify the degree to which water
diffusion in biologic tissues is non-Gaussian introducing the AKC parameter
(Apparent Kurtosis Coefficient). In this work we have realized DWI non-Gaussian
diffusion maps to be used in the clinical routine along with standard ADC maps,
giving to the radiologist another tool to explore how much structure inside a
voxel is organized. In particular in this work some prostate DWI examples have
been analyzed and will be shown.


title: Zeno Hall Effect

abstract:
  We show that the quantum Zeno effect gives rise to the Hall effect by
tailoring the Hilbert space of a two-dimensional lattice system into a single
Bloch band with a nontrivial Berry curvature. Consequently, a wave packet
undergoes transverse motion in response to a potential gradient -- a phenomenon
we call the Zeno Hall effect to highlight its quantum Zeno origin. The Zeno
Hall effect leads to retroreflection at the edge of the system due to an
interplay between the band flatness and the nontrivial Berry curvature. We
propose an experimental implementation of this effect with ultracold atoms in
an optical lattice.


title:
Evolution of perturbed dynamical systems: analytical computation with
  time independent accuracy

abstract:
  An analytical method for investigation of the evolution of dynamical systems
{\it with independent on time accuracy} is developed for perturbed Hamiltonian
systems. The error-free estimation using of computer algebra enables the
application of the method to complex multi-dimensional Hamiltonian and
dissipative systems. It also opens principal opportunities for the qualitative
study of chaotic trajectories. The performance of the method is demonstrated on
perturbed two-oscillator systems. It can be applied to various non-linear
physical and astrophysical systems, e.g. to the long-term planetary dynamics.


title: Radiative distortion of kinematic edges in cascade decays

abstract:
  Kinematic edges of cascade decays of new particles produced in high-energy
collisions may provide important constraints on the involved particles' masses.
For the exemplary case of gluino decay $\tilde{g}\to q\bar q \tilde{\chi}$ into
a pair of quarks and a neutralino through a squark resonance, we study the
hadronic invariant mass distribution in the vicinity of the kinematic edge. We
perform a next-to-leading order calculation in the strong coupling $\alpha_s$
and the ratio of squark width and squark mass $\Gamma_\tilde{q}/m_\tilde{q}$,
based on a systematic expansion in $\Gamma_\tilde{q}/m_\tilde{q}$. The
separation into hard, collinear and soft contributions elucidates the process
dependent and universal features of distributions in the edge region,
represented by on-shell decay matrix elements, universal jet functions and a
soft function that depends on the resonance propagator and soft Wilson lines.


title: Bayesian frequency analysis of HD 201433 observations with BRITE

abstract:
  Multiple oscillation frequencies separated by close to or less than the
formal frequency resolution of a data set are a serious problem in the
frequency analysis of time series data. We present a new and fully automated
Bayesian approach that searches for close frequencies in time series data and
assesses their significance by comparison to no signal and a mono-periodic
signal. We extensively test the approach with synthetic data sets and apply it
to the 156 days-long high-precision BRITE photometry of the SPB star HD 201433,
for which we find a sequence of nine statistically significant rotationally
split dipole modes.


title: Imaging and manipulation of skyrmion lattice domains in Cu2OSeO3

abstract:
  Nanoscale chiral skyrmions in noncentrosymmetric helimagnets are promising
binary state variables in high-density, low-energy nonvolatile memory.
Skyrmions are ubiquitous as an ordered, single-domain lattice phase, which
makes it difficult to write information unless they are spatially broken up
into smaller units, each representing a bit. Thus, the formation and
manipulation of skyrmion lattice domains is a prerequisite for memory
applications. Here, using an imaging technique based on resonant magnetic x-ray
diffraction, we demonstrate the mapping and manipulation of skyrmion lattice
domains in Cu2OSeO3. The material is particularly interesting for applications
owing to its insulating nature, allowing for electric field-driven domain
manipulation.


title:
Kinematics of the Local Universe XIV. Measurements from the 21 cm line
  and the HI mass function from a homogeneous catalog gathered with the
  Nan\c{c}ay radio telescope

abstract:
  This paper presents 828 new 21 cm neutral hydrogen line measurements carried
out with the FORT receiver of the meridian transit Nan\c{c}ay radio telescope
(NRT) in the years 2000 -- 2007. This observational program was part of a
larger project aimed at collecting an exhaustive and magnitude-complete HI
extragalactic catalog for Tully-Fisher applications. Through five massive data
releases, the KLUN series has collected a homogeneous sample of 4876 HI-spectra
of spiral galaxies, complete down to a flux of 5 Jy.km.s^{-1} and with
declination delta > -40{\deg}. We publish here the last release of the KLUN HI
observational program, corresponding to the faint end of the survey, with HI
masses ranging from 5 10^8 to 5 10^{10} solar masses. The size of this final
sample is comparable to the catalogs based on the Arecibo and Parkes radio
telescope campaigns, and it allows general HI mass distribution studies from a
set of homogeneous radio measurements.


title:
On the synchronization of coupled forced negative conductance circuits:
  A numerical study

abstract:
  In this paper, a numerical study on the complete synchronization phenomenon
exhibited by coupled forced negative conductance circuits is presented. The
nonlinear system exhibiting two types of chaotic attractors is studied for
complete synchronization of the identical chaotic attractors through phase
portraits under one type of coupling. The stability of the synchronized states
is observed for different coupling schemes of the circuit variables through
{\emph{Master Stability Function}}. The Conditional lyapunov exponents
explaining the dynamical behaviour of the driven system is presented.


title:
Cutoff latitude variation during solar proton events: Causes and
  consequences

abstract:
  To accurately quantify the effect of solar proton events (SPEs) on the
atmosphere requires a good estimate of the particle energy deposition in the
middle atmosphere (60- 100 km) and how the energy is distributed globally.
Protons in the energy range 1-20MeV, depositing their energy in the middle
atmosphere, are subject to more complex dynamics with strong day-night
asymmetries compared to higher-energy particles. Our study targets six SPEs
from 2003 to 2012. By using measurements from the Medium Energy Proton and
Electron Detector on all available Polar Orbit Environment Satellites (POES),
we show that in the main phase of geomagnetic storms the dayside cutoff
latitudes are pushed poleward, while the nightside cutoff latitudes have the
opposite response, resulting in strong day-night asymmetries in the energy
deposition. These features cannot bemeasured by the frequently used
Geostationary Operational Environmental Satellites (GOES). Assuming that the
protons impact the polar atmosphere homogeneously above a fixed nominal
latitude boundary will therefore give a significant overestimate of the energy
deposited in the middle atmosphere during SPEs. We discuss the magnetospheric
mechanisms responsible for the local time response in the cutoff latitudes and
provide a simple applicable parameterization which includes both dayside and
nightside cutoff latitude variability using only the Dst, the northward
component of the interplanetary magnetic field, and solar wind pressure. The
parameterization is utilized on the GOES particle fluxes, and the resulting
energy deposition successfully captures the day-night asymmetry in good
agreement with the energy deposition predicted from the POES measurement.


title:
Parity-Even and Time-Reversal-Odd Neutron Optical Potential in Spinning
  Matter Induced by Gravitational Torsion

abstract:
  Recent theoretical work has shown that spin $1/2$ particles moving through
unpolarized matter which sources torsion fields experience a new type of
parity-even and time-reversal-odd optical potential if the matter is spinning
in the lab frame. This new type of optical potential can be sought
experimentally using the helicity dependence of the total cross sections for
longitudinally polarized neutrons moving through a rotating cylindrical target.
In combination with recent experimental constraints on short-range P--odd,
T--even torsion interactions derived from polarized neutron spin rotation in
matter one can derive separate constraints on the time components of scalar and
pseudoscalar torsion fields in matter. We estimate the sensitivity achievable
in such an experiment and briefly outline some of the potential sources of
systematic error to be considered in any future experimental search for this
effect.


title: Long time behavior in locally activated random walks

abstract:
  We consider a 1-dimensional Brownian motion whose diffusion coefficient
varies when it crosses the origin. We study the long time behavior and we
establish different regimes, depending on the variations of the diffusion
coefficient: emergence of a non-Gaussian mul-tipeaked probability distribution
and a dynamical transition to an absorbing static state. We compute the
generator and we study the partial differential equation which involves its
adjoint. We discuss global existence and blow-up of the solution to this latter
equation.


title:
A remark on the single scattering preconditioner applied to boundary
  integral equations

abstract:
  This article deals with boundary integral equation preconditioning for the
multiple scattering problem. The focus is put on the single scattering
preconditioner, corresponding to the diagonal part of the integral operator,
for which two results are proved. Indeed, after applying this geometric
preconditioner, it appears that, firstly, every direct integral equations
become identical to each other, and secondly, that the indirect integral
equation of Brakhage-Werner becomes equal to the direct integral equations, up
to a change of basis. These properties imply in particular that the convergence
rate of a Krylov subspaces solver will be exactly the same for every
preconditioned integral equations. To illustrate this, some numerical
simulations are provided at the end of the paper.


title: Neyman-Pearson Test for Zero-Rate Multiterminal Hypothesis Testing

abstract:
  The problem of zero-rate multiterminal hypothesis testing is revisited from
the perspective of information-spectrum approach and finite blocklength
analysis. A Neyman-Pearson-like test is proposed and its non-asymptotic
performance is clarified; for a short block length, it is numerically
determined that the proposed test is superior to the previously reported
Hoeffding-like test proposed by Han-Kobayashi. For a large deviation regime, it
is shown that our proposed test achieves an optimal trade-off between the type
I and type II exponents presented by Han-Kobayashi. Among the class of
symmetric (type based) testing schemes, when the type I error probability is
non-vanishing, the proposed test is optimal up to the second-order term of the
type II error exponent; the latter term is characterized in terms of the
variance of the projected relative entropy density. The information geometry
method plays an important role in the analysis as well as the construction of
the test.


title:
Stability and convergence of time discretizations of quasi-linear
  evolution equations of Kato type

abstract:
  Semidiscretization in time is studied for a class of quasi-linear evolution
equations in a framework due to Kato, which applies to symmetric first-order
hyperbolic systems and to a variety of fluid and wave equations. In the regime
where the solution is suffciently regular, we show stability and optimal-order
convergence of the linearly implicit and fully implicit midpoint rules and of
higher-order implicit Runge{Kutta methods that are algebraically stable and
coercive, such as the collocation methods at Gauss nodes.


title: The Laplacian on the unit square in a self-similar manner

abstract:
  In this paper, we show how to construct the standard Laplacian on the unit
square in a self-similar manner. We rewrite the familiar mean value property of
planar harmonic functions in terms of averge values on small squares, from
which we could know how the planar self-similar resistance form and the
Laplacian look like. This approach combines the constructive
limit-of-difference-quotients method of Kigami for p.c.f. self-similar sets and
the method of averages introduced by Kusuoka and Zhou for the Sierpinski
carpet.


title:
Associative nature of event participation dynamics: a network theory
  approach

abstract:
  The affiliation with various social groups can be a critical factor when it
comes to quality of life of each individual, making such groups an essential
element of every society. The group dynamics, longevity and effectiveness
strongly depend on group's ability to attract new members and keep them engaged
in group activities. It was shown that high heterogeneity of scientist's
engagement in conference activities of the specific scientific community
depends on the balance between the numbers of previous attendances and
non-attendances and is directly related to scientist's association with that
community. Here we show that the same holds for leisure groups of the Meetup
website and further quantify individual members' association with the group. We
examine how structure of personal social networks is evolving with the event
attendance. Our results show that member's increasing engagement in the group
activities is primarily associated with the strengthening of already existing
ties and increase in the bonding social capital. We also show that Meetup
social networks mostly grow trough big events, while small events contribute to
the groups cohesiveness.


title:
Puddle-induced resistance oscillations in the breakdown of the graphene
  quantum Hall effect

abstract:
  We report on the stability of the quantum Hall plateau in wide Hall bars made
from a chemically gated graphene film grown on SiC. The $\nu=2$ quantized
plateau appears from fields $B \simeq 5$ T and persists up to $B \simeq 80$ T.
At high current density, in the breakdown regime, the longitudinal resistance
oscillates with a $1/B$ periodicity and an anomalous phase, which we relate to
the presence of additional electron reservoirs. The high field experimental
data suggest that these reservoirs induce a continuous increase of the carrier
density up to the highest available magnetic field, thus enlarging the quantum
plateaus. These in-plane inhomogeneities, in the form of high carrier density
graphene pockets, modulate the quantum Hall effect breakdown and decrease the
breakdown current.


title: Sums of the digits in bases 2 and 3

abstract:
  Let b $\ge$ 2 be an integer and let s b (n) denote the sum of the digits of
the representation of an integer n in base b. For sufficiently large N , one
has Card{n $\le$ N : |s 3 (n) -- s 2 (n)| $\le$ 0.1457205 log n} \textgreater{}
N 0.970359. The proof only uses the separate (or marginal) distributions of the
values of s 2 (n) and s 3 (n).


title:
Orders of Tate-Shafarevich groups for the Neumann-Setzer type elliptic
  curves

abstract:
  We present the results of our search for the orders of Tate-Shafarevich
groups for the Neumann-Setzer type elliptic curves.


title: Confinement in a three-dimensional Yang-Mills theory

abstract:
  We show that, starting from known exact classical solutions of the Yang-Mills
theory in three dimensions, the string tension is obtained and the potential is
consistent with a marginally confining theory. The potential we obtain agrees
fairly well with preceding findings in literature but here we derive it
analytically from the theory without further assumptions. The string tension is
in strict agreement with lattice results and the well-known theoretical result
by Karabali-Kim-Nair analysis. Classical solutions depend on a dimensionless
numerical factor arising from integration. This factor enters into the
determination of the spectrum and has been arbitrarily introduced in some
theoretical models. We derive it directly from the solutions of the theory and
is now fully justified. The agreement obtained with the lattice results for the
ground state of the theory is well below 1% at any value of the degree of the
group.


title: Flocking particles in a non-Newtonian shear thickening fluid

abstract:
  We prove existence and uniqueness of strong solutions to the Cucker--Smale
flocking model coupled with an incompressible viscous non-Newtonian fluid, with
the stress tensor of a power--law structure for $p\geq\frac{11}{5}$. The
coupling is performed through a drag force on a periodic spatial domain $T^3$.


title:
On hyperbolicity and Gevrey well-posedness. Part two: Scalar or
  degenerate transitions

abstract:
  For first-order quasi-linear systems of partial differential equations, we
formulate an assumption of a transition from initial hyperbolicity to
ellipticity. This assumption bears on the principal symbol of the first-order
operator. Under such an assumption, we prove a strong Hadamard instability for
the associated Cauchy problem, namely an instantaneous defect of H\"older
continuity of the flow from $G^{\sigma}$ to $L^2$, with $0 < \sigma <
\sigma_0$, the limiting Gevrey index $\sigma_0$ depending on the nature of the
transition. We restrict here to scalar transitions, and non-scalar transitions
in which the boundary of the hyperbolic zone satisfies a flatness condition. As
in our previous work for initially elliptic Cauchy problems [B. Morisse,
\textit{On hyperbolicity and Gevrey well-posedness. Part one: the elliptic
case}, arXiv:1611.07225], the instability follows from a long-time
Cauchy-Kovalevskaya construction for highly oscillating solutions. This extends
recent work of N. Lerner, T. Nguyen, and B. Texier [\textit{The onset of
instability in first-order systems}, to appear in J. Eur. Math. Soc.].


title:
Conformally covariant parametrizations for initial data in some modified
  Einstein gravity theories

abstract:
  We propose further conformal parametrizations for initial data in some
modified Einstein gravity theories. Some of them give rise to conformally
covariant systems.


title: Defect-induced magnetism in SiC probed by nuclear magnetic resonance

abstract:
  We give evidence for intrinsic, defect-induced bulk paramagnetism in SiC by
means of $^{13}$C and $^{29}$Si nuclear magnetic resonance (NMR) spectroscopy.
The temperature dependence of the internal dipole-field distribution, probed by
the spin part of the NMR Knight shift and the spectral linewidth, follows a
Curie law and scales very well with the macroscopic DC susceptibility. In order
to quantitatively analyze the NMR spectra, a microscopic model based on
dipole-dipole interactions was developed. The very good agreement between these
simulations and the NMR data establishes a direct relation between the
frequency distribution of the spectral intensity and the corresponding
real-space volumes of nuclear spins. The presented approach by NMR can be
applied to a variety of similar materials and, thus, opens a new avenue for the
microscopic exploration and exploitation of diluted bulk magnetism in
semiconductors.


title: Phenomenology of Left-Right Models in the quark sector

abstract:
  A natural avenue to extend the Standard Model (SM) is to embed it into a more
symmetric framework. Here, I focus in Left-Right (LR) Models, which treat left-
and right-handed chiralities on equal footing. Important information about the
structure of LR Models comes from meson-mixing observables. Due to the impact
of the new contributions to these processes, I consider the calculation of the
short-distance QCD effects correcting the LR Model contributions to
meson-mixing observables at the Next-to-Leading Order. I then revisit the
phenomenology of a simple realization of LR Models, containing doublet scalars,
and combine in a global fit electroweak precision observables, direct searches
of the new gauge bosons and meson oscillation observables, a task performed
within the CKMfitter statistical framework. Finally, I also cover a different
issue, namely the modeling of theoretical uncertainties, a class of
uncertainties specially important for flavour physics. Different frequentist
schemes are compared, and their differences are illustrated with
flavour-oriented examples.


title:
Stochastic thermodynamics for Ising chain and symmetric exclusion
  process

abstract:
  We verify the finite time fluctuation theorem for a linear Ising chain at its
ends in contact with heat reservoirs. Analytic results are derived for a chain
consisting of only two spins. The system can be mapped onto a model for
particle transport, namely the symmetric exclusion process, in contact with
thermal and particle reservoirs. We modify the symmetric exclusion process to
represent a thermal engine and reproduce universal features of the efficiency
at maximum power.


title:
Latitude and power characteristics of solar activity in the end of the
  Maunder minimum

abstract:
  Two important sources of information about sunspots in the Maunder minimum
are the Sp\"orer catalog and observations of the Paris observatory, which cover
in total the last quarter of the 17th and the first two decades of the 18th
century.
  These data, in particular, contain information about sunspot latitudes. As we
showed in previous papers, dispersions of sunspot latitude distributions are
tightly related to sunspot indices, so we can estimate the level of solar
activity in this epoch by a method which is not based on direct calculation of
sunspots and is weakly affected by loss of observational data.
  The latitude distributions of sunspots in the time of transition from the
Maunder minimum to the common regime of solar activity proved to be wide
enough. It gives evidences in favor of, first, not very low cycle No. -3
(1712-1723) with the Wolf number in maximum W=$100\pm50$, and, second, nonzero
activity in the maximum of cycle No. -4 (1700-1711) W=$60\pm45$.
  Therefore, the latitude distributions in the end of the Maunder minimum are
in better agreement with the traditional Wolf number and new revisited indices
of activity SN and GN than with the GSN; the latter provide much lower level of
activity in this epoch.


title: Cauchy-Compact flat spacetimes with BTZ singularities

abstract:
  The zoology of singularities for Lorentzian manifold is slightly more
complicated than for Riemannian manifolds. Our present work study
Cauchy-compact globally hyperbolic singular flat spacetimes with extreme
BTZ-like singular lines. We use the notion of BTZ-extension of a singular
spacetime introduced in a previous paper to give a description of Moduli spaces
of such manifolds in term of common Teichm{\"u}ller spaces. This description is
used to construct convex polyhedral cauchy-surface in Cauchy-compact flat
spacetimes with BTZ.


title:
Interpreting the Predictions of Complex ML Models by Layer-wise
  Relevance Propagation

abstract:
  Complex nonlinear models such as deep neural network (DNNs) have become an
important tool for image classification, speech recognition, natural language
processing, and many other fields of application. These models however lack
transparency due to their complex nonlinear structure and to the complex data
distributions to which they typically apply. As a result, it is difficult to
fully characterize what makes these models reach a particular decision for a
given input. This lack of transparency can be a drawback, especially in the
context of sensitive applications such as medical analysis or security. In this
short paper, we summarize a recent technique introduced by Bach et al. [1] that
explains predictions by decomposing the classification decision of DNN models
in terms of input variables.


title: Carnot efficiency at divergent power output

abstract:
  The widely debated feasibility of thermodynamic machines achieving Carnot
efficiency at finite power has been convincingly dismissed. Yet, the common
wisdom that efficiency can only be optimal in the limit of infinitely-slow
processes overlooks the dual scenario of infinitely-fast processes. We
corroborate that efficient engines at divergent power output are not
theoretically impossible, framing our claims within the theory of Stochastic
Thermodynamics. We inspect the case of an electronic quantum dot coupled to
three particle reservoirs to illustrate the physical rationale.


title: Nietzsche for physicists

abstract:
  One of the most important philosophers in history, the German Friedrich
Nietzsche, is almost ignored by physicists. This author who declared the death
of God in the 19th century was a science enthusiast, especially in the second
period of his work. With the aid of the physical concept of force, Nietzsche
created his concept of will to power. After thinking about energy conservation,
the German philosopher had some inspiration for creating his concept of eternal
recurrence. In this article, some influences of physics on Nietzsche are
pointed out, and the topicality of his epistemological position$-$the
perspectivism$-$is discussed. Considering the concept of will to power, I
propose that the perspectivism leads to an interpretation where physics and
science in general are viewed as a game.


title: Interferences in match kernels

abstract:
  We consider the design of an image representation that embeds and aggregates
a set of local descriptors into a single vector. Popular representations of
this kind include the bag-of-visual-words, the Fisher vector and the VLAD. When
two such image representations are compared with the dot-product, the
image-to-image similarity can be interpreted as a match kernel. In match
kernels, one has to deal with interference, i.e. with the fact that even if two
descriptors are unrelated, their matching score may contribute to the overall
similarity.
  We formalise this problem and propose two related solutions, both aimed at
equalising the individual contributions of the local descriptors in the final
representation. These methods modify the aggregation stage by including a set
of per-descriptor weights. They differ by the objective function that is
optimised to compute those weights. The first is a "democratisation" strategy
that aims at equalising the relative importance of each descriptor in the set
comparison metric. The second one involves equalising the match of a single
descriptor to the aggregated vector.
  These concurrent methods give a substantial performance boost over the state
of the art in image search with short or mid-size vectors, as demonstrated by
our experiments on standard public image retrieval benchmarks.


title:
Domain Adaptation by Mixture of Alignments of Second- or Higher-Order
  Scatter Tensors

abstract:
  In this paper, we propose an approach to the domain adaptation, dubbed
Second- or Higher-order Transfer of Knowledge (So-HoT), based on the mixture of
alignments of second- or higher-order scatter statistics between the source and
target domains. The human ability to learn from few labeled samples is a
recurring motivation in the literature for domain adaptation. Towards this end,
we investigate the supervised target scenario for which few labeled target
training samples per category exist. Specifically, we utilize two CNN streams:
the source and target networks fused at the classifier level. Features from the
fully connected layers fc7 of each network are used to compute second- or even
higher-order scatter tensors; one per network stream per class. As the source
and target distributions are somewhat different despite being related, we align
the scatters of the two network streams of the same class (within-class
scatters) to a desired degree with our bespoke loss while maintaining good
separation of the between-class scatters. We train the entire network in
end-to-end fashion. We provide evaluations on the standard Office benchmark
(visual domains), RGB-D combined with Caltech256 (depth-to-rgb transfer) and
Pascal VOC2007 combined with the TU Berlin dataset (image-to-sketch transfer).
We attain state-of-the-art results.


title:
Non-minimal Derivative Coupling Scalar Field and Bulk Viscous Dark
  Energy

abstract:
  Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity
for dark fluid in a spatially flat two-component Universe. Our viscous dark
energy model represents Phantom crossing avoiding Big-Rip singularity. We
propose a non-minimal derivative coupling scalar field with zero potential
leading to accelerated expansion of Universe in the framework of bulk viscous
dark energy model. In this approach, coupling constant ($\kappa$) is related to
viscosity coefficient ($\gamma$) and energy density of dark energy at the
present time ($\Omega_{\rm DE}^0$). This coupling is bounded as $\kappa\in
[-1/9H_0^2(1-\Omega_{\rm DE}^0), 0]$ and for $\gamma=0$ leads to $\kappa=0$. To
perform robust analysis, we implement recent observational data sets including
Joint Light-curve Analysis (JLA) for SNIa, Gamma Ray Bursts (GRBs) for most
luminous astrophysical objects at high redshifts, Baryon Acoustic Oscillations
(BAO) from different surveys, Hubble parameter from HST project, {\it Planck}
data for CMB power spectrum and CMB Lensing. Joint analysis of
JLA$+$GRBs$+$BAO$+$HST shows that $\Omega_{\rm DE}^0=0.696\pm 0.010$,
$\gamma=0.1404\pm0.0014$ and $H_0=68.1\pm1.3$ at $1\sigma$ confidence interval.
{\it Planck} TT observation provides $\gamma=0.32^{+0.31}_{-0.26}$ at $68\%$
confidence limit for viscosity coefficient. Tension in Hubble parameter is
alleviated in this model. Cosmographic distance ratio indicates that current
observed data prefer to increase bulk viscosity. Finally, the competition
between Phantom and Quintessence behavior of viscous dark energy model can
accommodate cosmological old objects reported as a sign of age crisis in
$\Lambda$CDM model.


title: Observations of Bow Shocks of Runaway Stars with H.E.S.S

abstract:
  Runaway stars form bow shocks by sweeping up interstellar matter in their
direction of motion. Theoretical models predict a spectrally wide non-thermal
component reaching up to gamma-ray energies at a flux level detectable with
current instruments. They were motivated by a detection of non-thermal radio
emission from the bow shock of BD$+43^\circ3654$ and a possible detection of
non-thermal X-rays from AE Aurigae. A search in the high-energy regime using
data from \textit{Fermi}-LAT resulted in flux upper limits for 27 candidates
listed in the first E-BOSS catalogue. We perform the first systematic search
for TeV emission from bow shocks of runaway stars. Using all available archival
H.E.S.S. I data we search for very-high-energy gamma-ray emission at the
positions of bow shock candidates listed in the second E-BOSS catalogue. This
catalogue comprises 73 bow shock candidates, 32 of which have been observed
with the H.E.S.S. telescopes. None of the observed bow shock candidates shows
significant emission in the H.E.S.S. energy range. The resulting upper limits
are used to constrain current models for non-thermal emission from these
objects.


title: Burrows-Wheeler transform and LCP array construction in constant space

abstract:
  In this article we extend the elegant in-place Burrows-Wheeler transform
(BWT) algorithm proposed by Crochemore et al. (Crochemore et al., 2015). Our
extension is twofold: we first show how to compute simultaneously the longest
common prefix (LCP) array as well as the BWT, using constant additional space;
we then show how to build the LCP array directly in compressed representation
using Elias coding, still using constant additional space and with no
asymptotic slowdown. Furthermore, we provide a time/space tradeoff for our
algorithm when additional memory is allowed. Our algorithm runs in quadratic
time, as does Crochemore et al.'s, and is supported by interesting properties
of the BWT and of the LCP array, contributing to our understanding of the
time/space tradeoff curve for building indexing structures.


title: On the full bosonic string from Minkowski space to Riemannian manifolds

abstract:
  We study the action of the full bosonic string for the domain being
two-dimensional Minkowski space and the target a Riemannian manifold. Its
critical points couple the wave map equation to a scalar and a two-form
potential. Besides investigating their basic features we establish existence
results for the latter.


title:
Linking microstructural evolution and macro-scale friction behavior in
  metals

abstract:
  A correlation is established between the macro-scale friction regimes of
metals and a transition between two dominant atomistic mechanisms of
deformation. Metals tend to exhibit bi-stable friction behavior -- low and
converging or high and diverging. These general trends in behavior are shown to
be largely explained using a simplified model based on grain size evolution, as
a function of contact stress and temperature, and are demonstrated for pure
copper and gold. Specifically, the low friction regime is linked to the
formation of ultra-nanocrystalline surface films (10 to 20 nm), driving toward
shear accommodation by grain boundary sliding. Above a critical combination of
stress and temperature -- demonstrated to be a material property -- shear
accommodation transitions to dislocation dominated plasticity and high
friction. We utilize a combination of experimental and computational methods to
develop and validate the proposed structure-property relationship. This
quantitative framework provides a shift from phenomenological to mechanistic
and predictive fundamental understanding of friction for crystalline materials,
including engineering alloys.


title: Dynamic scaling in natural swarms

abstract:
  Collective behaviour in biological systems pitches us against theoretical
challenges way beyond the borders of ordinary statistical physics. The lack of
concepts like scaling and renormalization is particularly grievous, as it
forces us to negotiate with scores of details whose relevance is often hard to
assess. In an attempt to improve on this situation, we present here
experimental evidence of the emergence of dynamic scaling laws in natural
swarms. We find that spatio-temporal correlation functions in different swarms
can be rescaled by using a single characteristic time, which grows with the
correlation length with a dynamical critical exponent z~1. We run simulations
of a model of self-propelled particles in its swarming phase and find z~2,
suggesting that natural swarms belong to a novel dynamic universality class.
This conclusion is strengthened by experimental evidence of non-exponential
relaxation and paramagnetic spin-wave remnants, indicating that previously
overlooked inertial effects are needed to describe swarm dynamics. The absence
of a purely relaxational regime suggests that natural swarms are subject to a
near-critical censorship of hydrodynamics.


title:
An SQP method for mathematical programs with vanishing constraints with
  strong convergence properties

abstract:
  We propose an SQP algorithm for mathematical programs with vanishing
constraints which solves at each iteration a quadratic program with linear
vanishing constraints. The algorithm is based on the newly developed concept of
$\mathcal Q$-stationarity [5]. We demonstrate how $\mathcal Q_M$-stationary
solutions of the quadratic program can be obtained. We show that all limit
points of the sequence of iterates generated by the basic SQP method are at
least M-stationary and by some extension of the method we also guarantee the
stronger property of $\mathcal Q_M$-stationarity of the limit points.


title:
Stability of the interstellar hydrogen inflow longitude from 20 years of
  SOHO/SWAN observations

abstract:
  Aims. A recent debate on the decade-long stability of the interstellar He
flow vector, and in particular the flow longitude, has prompted us to check for
any variability in the interstellar H flow vector as observed by the SWAN
instrument on board SOHO. Methods. We used a simple model-independent method to
determine the interstellar H flow longitude, based on the parallax effects
induced on the Lyman-{\alpha} intensity measured by SWAN following the
satellite motion around the Sun. Results. Our results show that the
interstellar H flow vector longitude does not vary significantly from an
average value of 252.9$^{\circ}$ $\pm$ 1.4$^{\circ}$ throughout the 20-year
span of the SWAN dataset, further strengthening the arguments for the stability
of the interstellar gas flow.


title: Perpetually Dominating Large Grids

abstract:
  In the m-\emph{Eternal Domination} game, a team of guard tokens initially
occupies a dominating set on a graph $G$. An attacker then picks a vertex
without a guard on it and attacks it. The guards defend against the attack: one
of them has to move to the attacked vertex, while each remaining one can choose
to move to one of his neighboring vertices. The new guards' placement must
again be dominating. This attack-defend procedure continues eternally. The
guards win if they can eternally maintain a dominating set against any sequence
of attacks, otherwise, the attacker wins.
  The m-\emph{eternal domination number} for a graph $G$ is the minimum amount
of guards such that they win against any attacker strategy in $G$ (all guards
move model). We study rectangular grids and provide the first known general
upper bound on the m-eternal domination number for these graphs. Our novel
strategy implements a square rotation principle and eternally dominates $m
\times n$ grids by using approximately $\frac{mn}{5}$ guards, which is
asymptotically optimal even for ordinary domination.


title:
Optically switched magnetism in photovoltaic perovskite
  CH$_3$NH$_3$(Mn:Pb)I$_3$

abstract:
  The demand for ever-increasing density of information storage and speed of
manipulation boosts an intense search for new magnetic materials and novel ways
of controlling the magnetic bit. Here, we report the synthesis of a
ferromagnetic photovoltaic CH$_3$NH$_3$(Mn:Pb)I$_3$ material in which the
photo-excited electrons rapidly melt the local magnetic order through the
Ruderman-Kittel-Kasuya-Yosida interactions without heating up the spin system.
Our finding offers an alternative, very simple and efficient way of optical
spin control, and opens an avenue for applications in low power, light
controlling magnetic devices.


title:
New verifiable stationarity concepts for a class of mathematical
  programs with disjunctive constraints

abstract:
  In this paper we consider a sufficiently broad class of nonlinear
mathematical programs with disjunctive constraints, which, e.g., include
mathematical programs with complemetarity/vanishing constraints. We present an
extension of the concept of ${\mathcal Q}$-stationarity as introduced in the
recent paper [2]. ${\mathcal Q}$-stationarity can be easily combined with the
well-known notion of M-stationarity to obtain the stronger property of
so-called ${\mathcal Q}_M$-stationarity. We show how the property of ${\mathcal
Q}_M$-stationarity (and thus also of M-stationarity) can be efficiently
verified for the considered problem class by computing ${\mathcal
Q}$-stationary solutions of a certain quadratic program. We consider further
the situation that the point which is to be tested for ${\mathcal
Q}_M$-stationarity, is not known exactly, but is approximated by some
convergent sequence, as it is usually the case when applying some numerical
method.


title: Texture Synthesis with Spatial Generative Adversarial Networks

abstract:
  Generative adversarial networks (GANs) are a recent approach to train
generative models of data, which have been shown to work particularly well on
image data. In the current paper we introduce a new model for texture synthesis
based on GAN learning. By extending the input noise distribution space from a
single vector to a whole spatial tensor, we create an architecture with
properties well suited to the task of texture synthesis, which we call spatial
GAN (SGAN). To our knowledge, this is the first successful completely
data-driven texture synthesis method based on GANs.
  Our method has the following features which make it a state of the art
algorithm for texture synthesis: high image quality of the generated textures,
very high scalability w.r.t. the output texture size, fast real-time forward
generation, the ability to fuse multiple diverse source images in complex
textures. To illustrate these capabilities we present multiple experiments with
different classes of texture images and use cases. We also discuss some
limitations of our method with respect to the types of texture images it can
synthesize, and compare it to other neural techniques for texture generation.


title: The problem of Pi_2-cut-introduction

abstract:
  We describe an algorithmic method of proof compression based on the
introduction of Pi_2-cuts into a cut-free LK-proof. The current approach is
based on an inversion of Gentzen s cut-elimination method and extends former
methods for introducing Pi_1-cuts. The Herbrand instances of a cut-free proof
pi of a sequent S are described by a grammar G which encodes substitutions
defined in the elimination of quantified cuts. We present an algorithm which,
given a grammar G, constructs a Pi_2-cut formula A and a proof phi of S with
one cut on A. It is shown that, by this algorithm, we can achieve an
exponential proof compression.


title: Search on a Line by Byzantine Robots

abstract:
  We consider the problem of fault-tolerant parallel search on an infinite line
by $n$ robots. Starting from the origin, the robots are required to find a
target at an unknown location. The robots can move with maximum speed $1$ and
can communicate in wireless mode among themselves. However, among the $n$
robots, there are $f$ robots that exhibit {\em byzantine faults}. A faulty
robot can fail to report the target even after reaching it, or it can make
malicious claims about having found the target when in fact it has not. Given
the presence of such faulty robots, the search for the target can only be
concluded when the non-faulty robots have sufficient verification that the
target has been found. We aim to design algorithms that minimize the value of
$S_d(n,f)$, the time to find a target at a distance $d$ from the origin by $n$
robots among which $f$ are faulty. We give several different algorithms whose
running time depends on the ratio $f/n$, the density of faulty robots, and also
prove lower bounds. Our algorithms are optimal for some densities of faulty
robots.


title:
Semiexclusive production of $J/\psi$ mesons in proton-proton collisions
  with electromagnetic and diffractive dissociation of one of the protons

abstract:
  We calculate the cross sections for both electromagnetic and diffractive
dissociation of protons for semiexclusive production of $J/\psi$ mesons in
proton-proton collisions at the LHC. Several differential distributions in
missing mass ($M_X$), or single-particle variables related exclusively to the
$J/\psi$ meson are calculated for $\sqrt{s}$ = 7 TeV as an example. The cross
sections and distributions are compared to the cross section of the purely
exclusive reaction $p p \to p p J/\psi$. We show the corresponding ratio as a
function of $J/\psi$ meson rapidity. We compare the distributions for purely
electromagnetic and purely diffractive proton excitations/dissociation. We
predict cross sections for electromagnetic and diffractive excitations of
similar order of magnitude.


title:
Polarized heat current generated by quantum pumping in two-dimensional
  topological insulators

abstract:
  We consider transport properties of a two dimensional topological insulator
in a double quantum point contact geometry in presence of a time-dependent
external field. In the proposed setup an external gate is placed above a single
constriction and it couples only with electrons belonging to the top edge. This
asymmetric configuration and the presence of an ac signal allow for a quantum
pumping mechanism, which, in turn, can generate finite heat and charge currents
in an unbiased device configuration. A microscopic model for the coupling with
the external time-dependent gate potential is developed and the induced finite
heat and charge currents are investigated. We demonstrate that in the
non-interacting case, heat flow is associated with a single spin component, due
to the helical nature of the edge states, and therefore a finite and polarized
heat current is obtained in this configuration. The presence of e-e
interchannel interactions strongly affects the current signal, lowering the
degree of polarization of the system. Finally, we also show that separate heat
and charge flows can be achieved, varying the amplitude of the external gate.