title:
Risk and Ambiguity in Information Seeking: Eye Gaze Patterns Reveal
  Contextual Behaviour in Dealing with Uncertainty

abstract:
  Information foraging connects optimal foraging theory in ecology with how
humans search for information. The theory suggests that, following an
information scent, the information seeker must optimize the tradeoff between
exploration by repeated steps in the search space vs. exploitation, using the
resources encountered. We conjecture that this tradeoff characterizes how a
user deals with uncertainty and its two aspects, risk and ambiguity in economic
theory. Risk is related to the perceived quality of the actually visited patch
of information, and can be reduced by exploiting and understanding the patch to
a better extent. Ambiguity, on the other hand, is the opportunity cost of
having higher quality patches elsewhere in the search space. The aforementioned
tradeoff depends on many attributes, including traits of the user: at the two
extreme ends of the spectrum, analytic and wholistic searchers employ entirely
different strategies. The former type focuses on exploitation first,
interspersed with bouts of exploration, whereas the latter type prefers to
explore the search space first and consume later. Based on an eye-tracking
study of experts' interactions with novel search interfaces in the biomedical
domain, we demonstrate that perceived risk shifts the balance between
exploration and exploitation in either type of users, tilting it against vs. in
favour of ambiguity minimization. Since the pattern of behaviour in information
foraging is quintessentially sequential, risk and ambiguity minimization cannot
happen simultaneously, leading to a fundamental limit on how good such a
tradeoff can be. This in turn connects information seeking with the emergent
field of quantum decision theory.


title: Kahler and symplectic structures on 4-manifolds and hyperKahler geometry

abstract:
  A non-linear generalization of the Dirac operator in 4-dimensions, obtained
by replacing the spinor representation with a hyperKahler manifold admitting
certain symmetries, is considered. We show that the existence of a covariantly
constant, generalized spinor defines a Kahler structure on the base
4-dimensional manifold. For a class of hyperKahler manifolds obtained via
hyperKahler reduction, we also show that a harmonic spinor, under mild
conditions, defines a symplectic structure. Finally, we show that if a
covariantly constant, generalized spinor satisfies generalized Seiberg-Witten
equations, the metric on the base manifold has a constant scalar curvature.


title:
Spin wave power flow and caustics in ultrathin ferromagnets with the
  Dzyaloshinskii-Moriya interaction

abstract:
  The Dzyaloshinskii-Moriya interaction in ultrathin ferromagnets can result in
nonreciprocal propagation of spin waves. We examine theoretically how spin wave
power flow is influenced by this interaction. We show that the combination of
the dipole-dipole and Dzyaloshinskii-Moriya interactions can result in
unidirectional caustic beams in the Damon-Eshbach geometry. Morever,
self-generated interface patterns can also be induced from a point-source
excitation.


title:
Geometric ergodicity of Rao and Teh's algorithm for Markov jump
  processes and CTBNs

abstract:
  Rao and Teh (2012, 2013) introduced an efficient MCMC algorithm for sampling
from the posterior distribution of a hidden Markov jump process. The algorithm
is based on the idea of sampling virtual jumps. In the present paper we show
that the Markov chain generated by Rao and Teh's algorithm is geometrically
ergodic. To this end we establish a geometric drift condition towards a small
set. A similar result is also proved for a special version of the algorithm,
used for probabilistic inference in Continuous Time Bayesian Networks.


title: Superconductivity at 35 K by self doping in RbGd$_2$Fe$_4$As$_4$O$_2$

abstract:
  We report synthesis, crystal structure and physical properties of a novel
quinary compound RbGd$_2$Fe$_4$As$_4$O$_2$. The new iron oxyarsenide is
isostructural to the fluo-arsenide KCa$_2$Fe$_4$As$_4$F$_2$, both of which
contain separate double Fe$_2$As$_2$ layers that are self hole-doped in the
stoichiometric composition. Bulk superconductivity at $T_\mathrm{c}$ = 35 K is
demonstrated by the measurements of electrical resistivity, dc magnetic
susceptibility and heat capacity. An exceptionally high value of the initial
slope of the upper critical field
($\mu_0$d$H_{\mathrm{c2}}$/d$T|_{T_\mathrm{c}}$ = 16.5 T/K) is measured for the
polycrystalline sample.


title:
On Keiding's Equation and its relation to differential equations about
  prevalence and incidence in chronic disease epidemiology

abstract:
  We study the relation between the age-specific prevalence, incidence and
mortality in an illness-death model consisting of the three states Healthy,
Ill, Dead. The dependency on three different time scales (age, calendar time,
disease duration) is considered. It is shown that Keiding's equation published
in 1991 is a generalisation of the solution of Brunet and Struchiner's partial
differential equation from 1999. In a special case, we propose a particularly
simple estimate of the incidence from prevalence data.


title: Skyrmions at the edge: Confinement effects in Fe/Ir(111)

abstract:
  We have employed spin-polarized scanning tunneling microscopy and Monte-Carlo
simulations to investigate the effect of lateral confinement onto the
nanoskyrmion lattice in Fe/Ir(111). We find a strong coupling of one diagonal
of the square magnetic unit cell to the close-packed edges of Fe
nanostructures. In triangular islands this coupling in combination with the
mismatching symmetries of the islands and of the square nanoskyrmion lattice
leads to frustration and triple-domain states. In direct vicinity to
ferromagnetic NiFe islands, the surrounding skyrmion lattice forms additional
domains. In this case a side of the square magnetic unit cell prefers a
parallel orientation to the ferromagnetic edge. These experimental findings can
be reproduced and explained by Monte-Carlo simulations. Here, the single-domain
state of a triangular island is lower in energy, but nevertheless multi-domain
states occur due to the combined effect of entropy and an intrinsic domain wall
pinning arising from the skyrmionic character of the spin texture.


title: Online Informative Path Planning for Active Classification on UAVs

abstract:
  We propose an informative path planning (IPP) algorithm for active
classification using an unmanned aerial vehicle (UAV), focusing on weed
detection in precision agriculture. We model the presence of weeds on farmland
using an occupancy grid and generate plans according to information-theoretic
objectives, enabling the UAV to gather data efficiently. We use a combination
of global viewpoint selection and evolutionary optimization to refine the UAV's
trajectory in continuous space while satisfying dynamic constraints. We
validate our approach in simulation by comparing against standard "lawnmower"
coverage, and study the effects of varying objectives and optimization
strategies. We plan to evaluate our algorithm on a real platform in the
immediate future.


title: Supervised learning based on temporal coding in spiking neural networks

abstract:
  Gradient descent training techniques are remarkably successful in training
analog-valued artificial neural networks (ANNs). Such training techniques,
however, do not transfer easily to spiking networks due to the spike generation
hard non-linearity and the discrete nature of spike communication. We show that
in a feedforward spiking network that uses a temporal coding scheme where
information is encoded in spike times instead of spike rates, the network
input-output relation is differentiable almost everywhere. Moreover, this
relation is piece-wise linear after a transformation of variables. Methods for
training ANNs thus carry directly to the training of such spiking networks as
we show when training on the permutation invariant MNIST task. In contrast to
rate-based spiking networks that are often used to approximate the behavior of
ANNs, the networks we present spike much more sparsely and their behavior can
not be directly approximated by conventional ANNs. Our results highlight a new
approach for controlling the behavior of spiking networks with realistic
temporal dynamics, opening up the potential for using these networks to process
spike patterns with complex temporal information.


title:
Influence of non-collisional laser heating on the electron dynamics in
  dielectric materials

abstract:
  The electron dynamics in dielectric materials induced by intense femtosecond
laser pulses is theoretically addressed. The laser driven temporal evolution of
the energy distribution of electrons in the conduction band is described by a
kinetic Boltzmann equation. In addition to the collisional processes for energy
transfer such as electron-phonon-photon and electron-electron interactions, a
non-collisional process for photon absorption in the conduction band is
included. It relies on direct transitions between sub-bands of the conduction
band through multiphoton absorption. This mechanism is shown to significantly
contribute to the laser heating of conduction electrons for large enough laser
intensities. It also increases the time required for the electron distribution
to reach the equilibrium state as described by the Fermi-Dirac statistics.
Quantitative results are provided for quartz irradiated by a femtosecond laser
pulse with a wavelength of 800 nm and for intensities in the range of tens of
TW/cm$^2$, lower than the ablation threshold. The change in the energy
deposition induced by this non-collisional heating process is expected to have
a significant influence on the laser processing of dielectric materials.


title:
Study of optical nonlinearity of a highly dispersive medium using
  optical heterodyne detection technique

abstract:
  We discuss the optical heterodyne detection technique to study the absorption
and dispersion of a probe beam propagating through a medium with a narrow
resonance. The technique has been demonstrated for Rydberg Electro-magnetically
induced transparency (EIT) in rubidium thermal vapor and the optical
non-linearity of a probe beam with variable intensity has been studied. A
quantitative comparison of the experimental result with a suitable theoretical
model is presented. The limitations and the working regime of the technique are
discussed.


title: Final Results of the MEG Experiment

abstract:
  Transitions of charged leptons from one generation to another are basically
prohibited in the Standard Model because of the mysteriously tiny neutrino
masses, although such flavor-violating transitions have been long observed for
quarks and neutrinos. Supersymmetric Grand Unified Theories (SUSY GUT), which
unify quarks and leptons as well as their forces, predict that charged leptons
should also make such transitions at small but experimentally observable rates.
The MEG experiment was the first to have explored one of such transitions, mu+
-> e+ gamma decays, down to the branching ratios predicted by SUSY GUT. Here we
report the final results of the MEG experiment based on the full dataset
collected from 2009 to 2013 at the Paul Scherrer Institut, corresponding to a
total of 7.5 x 10^14 stopped muons on target. No excess for mu+ -> e+ gamma
decays was found. Thus the most stringent upper bound was placed on the
branching ratio, B(mu+ -> e+ gamma) < 4.2 x 10^-13 at 90% C.L., about 30 times
tighter than previous experiments, and severely constrains SUSY GUT and other
well-motivated theories. We are now preparing the upgraded experiment MEG II
with an aim to achieve a sensitivity of 4 x 10^-14 after three years of data
taking. It is expected to start late in 2017.


title:
Extended field-of-view in a lensless endoscope using an aperiodic
  multicore fiber

abstract:
  We investigate lensless endoscopy using coherent beam combining and aperiodic
multicore fibers (MCF). We show that diffracted orders, inherent to MCF with
periodically arranged cores, dramatically reduce the field of view (FoV) and
that randomness in MCF core positions can increase the FoV up to the
diffraction limit set by a single fiber core, while maintaining MCF
experimental feasibility. We demonstrate experimentally pixelation-free
lensless endoscopy imaging over a 120 micron FoV with an aperiodic MCF designed
with widely spaced cores. We show that this system is suitable to perform beam
scanning imaging by simply applying a tilt to the proximal wavefront.


title:
Measurement of forward-backward multiplicity correlations in lead-lead,
  proton-lead and proton-proton collisions with the ATLAS detector

abstract:
  Two-particle pseudorapidity correlations are measured in $\sqrt{s_{\rm{NN}}}$
= 2.76 TeV Pb+Pb, $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV $p$+Pb, and $\sqrt{s}$ = 13
TeV $pp$ collisions at the LHC, with total integrated luminosities of
approximately 7 $\mu\mathrm{b}^{-1}$, 28 $\mathrm{nb}^{-1}$, and 65
$\mathrm{nb}^{-1}$, respectively. The correlation function $C_{\rm
N}(\eta_1,\eta_2)$ is measured as a function of event multiplicity using
charged particles in the pseudorapidity range $|\eta|<2.4$. The correlation
function contains a significant short-range component, which is estimated and
subtracted. After removal of the short-range component, the shape of the
correlation function is described approximately by $1+\langle{a_1^2}\rangle
\eta_1\eta_2$ in all collision systems over the full multiplicity range. The
values of $\sqrt{\langle{a_1^2}\rangle}$ are consistent between the
opposite-charge pairs and same-charge pairs, and for the three collision
systems at similar multiplicity. The values of $\sqrt{\langle{a_1^2}\rangle}$
and the magnitude of the short-range component both follow a power-law
dependence on the event multiplicity. The $\eta$ distribution of the
short-range component, after symmetrizing the proton and lead directions in
$p$+Pb collisions, is found to be smaller than that in $pp$ collisions with
comparable multiplicity.


title: A Master Action for D=11 Supergravity in the Component Formulation

abstract:
  We give a solution to the classical master equation of D=11 supergravity in
the conventional component formulation. Based on a careful investigation of the
symmetry algebra including terms proportional to the equation of motion, we
construct an explicit expression of the master action in an order-by-order
manner.


title: Detectors and Concepts for sub-100 ps timing with gaseous detectors

abstract:
  We give a short compendium of the main ongoing detectors and concepts capable
of performing accurate sub-100 ps timing at high particle fluxes and on large
areas, through technologies based on gaseous media. We briefly discuss the
state-of-the-art, technological limitations and prospects, and a new bizarre
idea.


title: Three Magnetic Rotation Bands in 84^Rb

abstract:
  High-spin states in $^{84}$Rb are studied by using the $^{70}$Zn($^{18}$O,
p3n)$^{84}$Rb reaction at beam energy of 75 MeV. Three high-lying
negative-parity bands are established, whose level spacings are very regular,
i.e., there don't exist signature splitting. The dipole character of the
transitions of these three bands is assigned by the $\gamma$-$\gamma$
directional correlations of oriented states (DCO) intensity ratios and the
multipolarity M1 is suggested by the analogy to multiparticle excitations in
neighboring nuclei. The strong M1 and weak or no E2 transitions are observed.
All these characteristic features show they are magnetic rotation bands.


title: On plasma density blobs in drift turbulence

abstract:
  By keeping nonlinear Boltzmann factor in electron density dependence on
electrostatic potential it is demonstrated that large plasma density blobs,
often seen in experiment inside separatrix, can exist within the framework of
drift wave dynamics. The estimates show that plasma density in a blob can be ~3
times higher that average plasma density, but hardly exceeds this limit, which
in a ball park is in agreement with experimental observations.


title:
Comment on "Dual-wavelength in-line phase-shifting interferometry based
  on two dc-term-suppressed intensities with a special phase shift for
  quantitative phase extraction"

abstract:
  We comment on the recent Letter by Xu and Wang et al. [Opt. Lett. 41, 2430
(2016)] in which an approach of quantitative phase extraction in
dual-wavelength in-line phase-shifting interferometry (DWILPSI) was proposed.
It is noted that a special phase shift is used, which more or less embarrasses
its practical operation. We wish to show that the same result can also be
reached by combining the generalized phase-shifting algorithm and the
least-square algorithm, in which the phase shift can be chosen randomly. In
addition to maintaining high accuracy and rapid processing speed of the DWILPSI
method, the proposed method greatly facilitates its application in actual
measurement.


title:
Universal transport dynamics in a quenched tunnel-coupled Luttinger
  liquid

abstract:
  The transport dynamics of a quenched Luttinger liquid tunnel-coupled to a
fermionic reservoir is investigated. In the transient dynamics, we show that
for a sudden quench of the electron interaction universal power-law decay in
time of the tunneling current occurs, ascribed to the presence of entangled
compound excitations created by the quench. In sharp contrast to the usual non
universal power-law behavior of a zero-temperature non-quenched Luttinger
liquid, the steady state tunneling current is ohmic and can be explained in
terms of an effective quench-activated heating of the system. Our study unveils
an unconventional dynamics for a quenched Luttinger liquid that could be
identified in quenched cold Fermi gases.


title: Quasilocal energy and surface geometry of Kerr spacetime

abstract:
  We study the quasi-local energy (QLE) and the surface geometry for Kerr
spacetime in the Boyer-Lindquist coordinates without taking the slow rotation
approximation. We also consider in the region $r\leq2m$, which is inside the
ergosphere. For a certain region, $r>r_{k}(a)$, the Gaussian curvature of the
surface with constant $t,r$ is positive, and for $r>\sqrt{3}a$ the critical
value of the QLE is positive. We found that the three curves: the outer horizon
$r=r_{+}(a)$, $r=r_{k}(a)$ and $r=\sqrt{3}a$ intersect at the point
$a=\sqrt{3}m/2$, which is the limit for the horizon to be isometrically
embedded into $\mathbb{R}^3$. The numerical result indicates that the Kerr QLE
is monotonically decreasing to the ADM $m$ from the region inside the
ergosphere to large $r$. Based on the second law of black hole dynamics, the
QLE is increasing with respect to the irreducible mass $M_{\mathrm{ir}}$. From
a results of Chen-Wang-Yau, we conclude that in a certain region, $r>r_{h}(a)$,
the critical value of the Kerr QLE is a global minimum.


title:
Low-pressure phase diagram of crystalline benzene from quantum Monte
  Carlo

abstract:
  We study the low-pressure (0 to 10 GPa) phase diagram of crystalline benzene
using quantum Monte Carlo (QMC) and density functional theory (DFT) methods. We
consider the $Pbca$, $P4_32_12$, and $P2_1/c$ structures as the best candidates
for phase I and phase II. We perform diffusion quantum Monte Carlo (DMC)
calculations to obtain accurate static phase diagrams as benchmarks for modern
van der Waals density functionals. We use density functional perturbation
theory to compute phonon contribution in the free-energy calculations. Our DFT
enthalpy-pressure phase diagram indicates that the $Pbca$ and $P2_1/c$
structures are the most stable phases within the studied pressure range. The
DMC Gibbs free-energy calculations predict that the room temperature $Pbca$ to
$P2_1/c$ phase transition occurs at 2.1(1) GPa. This prediction is consistent
with available experimental results at room temperature. Our DMC calculations
show an estimate of 50.6$\pm$0.5 kJ/mol for crystalline benzene lattice energy.


title: Minimal Higgs inflation

abstract:
  In this paper we propose two simple minimal Higgs inflation scenarios through
a simple modification of the Higgs potential, as opposed to the usual
non-minimal Higgs-gravity coupling prescription. The modification is done in
such a way that it creates a flat plateau for a huge range of field values at
the inflationary energy scale $\mu \simeq (\lambda)^{1/4} \alpha$. Assuming the
perturbative Higgs quartic coupling, $\lambda \simeq {\cal O}(1)$, for both the
models inflation energy scale turned out to be $\mu \simeq (10^{14}, 10^{15})$
GeV, and prediction of all the cosmologically relevant quantities,
$(n_s,r,dn_s^k)$, fit extremely well with observations made by PLANCK.
Considering observed central value of the scalar spectral index, $n_s= 0.968$,
our two models predict efolding number, $N = (52,47)$. Within a wide range of
viable parameter space, we found that the prediction of tensor to scalar ratio
$r (\leq 10^{-5})$ is far below the current experimental sensitivity to be
observed in the near future. The prediction for the running of scalar spectral
index, $dn_s^k$, approximately remains the same as was predicted by the usual
chaotic and quartic inflation scenario. We also the computed the background
field dependent unitarity scale $\Lambda(h)$, which turned out to be much
larger than the aforementioned inflationary energy.


title: Probability of noise- and rate-induced tipping

abstract:
  We propose an approximation for the probability of tipping when the speed of
parameter change and additive white noise interact to cause tipping. Our
approximation is valid for small to moderate drift speeds and helps to estimate
the probability of false positives and false negatives in early-warning
indicators in the case of rate- and noise-induced tipping. We illustrate our
approximation on a prototypical model for rate-induced tipping with additive
noise using Monte-Carlo simulations. The formula can be extended to close
encounters of rate-induced tipping and is otherwise applicable to other forms
of tipping.
  We also provide an asymptotic formula for the critical ramp speed of the
parameter in the absence of noise for a general class of systems undergoing
rate-induced tipping.


title: Computing graded Betti tables of toric surfaces

abstract:
  We present various facts on the graded Betti table of a projectively embedded
toric surface, expressed in terms of the combinatorics of its defining lattice
polygon. These facts include explicit formulas for a number of entries, as well
as a lower bound on the length of the linear strand that we conjecture to be
sharp (and prove to be so in several special cases). We also present an
algorithm for determining the graded Betti table of a given toric surface by
explicitly computing its Koszul cohomology, and report on an implementation in
SageMath. This works well for ambient projective spaces of dimension up to
roughly $25$, depending on the concrete combinatorics, although the current
implementation runs in finite characteristic only. As a main application we
obtain the graded Betti table of the Veronese surface $\nu_6(\mathbb{P}^2)
\subseteq \mathbb{P}^{27}$ in characteristic $40\,009$. This allows us to
formulate precise conjectures predicting what certain entries look like in the
case of an arbitrary Veronese surface $\nu_d(\mathbb{P}^2)$.


title:
Photocentric orbits from a direct combination of ground-based astrometry
  with Hipparcos II. Preliminary orbits for six astrometric binaries

abstract:
  Based on a direct combination of the Hipparcos data with astrometric
ground-based observational catalogues having epochs between 1938 and 1999 the
preliminary orbits and component masses are calculated for 6 binaries with no
previous orbit calculation: $\iota$~Vir (HIP~69701) with period of 55 years,
photocentric semi-major axis of 200 mas, relative semi-major axis of 830 mas
and a dwarf secondary of 0.6 solar masses; $\gamma$~UMa (HIP~58001) -- 20.5
years, 90 mas, 460 mas and a dwarf secondary of 0.8 solar masses; $\kappa$~Del
(HIP~101916) -- 45 years, 100 mas, 520 mas and a dwarf secondary of 0.4 solar
masses; 20~Oph (HIP~82369) -- 35.5 years, 140 mas, 460 mas and a dwarf
secondary of 0.8 solar masses; $\mu$~Ser (HIP~77516) -- 36 years, 110 mas, 350
mas and a secondary of 2.3 solar masses; as well as a possible new component of
Mizar~A ($\zeta$~UMa, HIP~65378) -- 36.5 years, 180 mas, 780 mas, 1.5 solar
masses. The latter may be a pair of dwarfs.


title:
Secular Gravity Gradients in Non-Dynamical Chern-Simons Modified Gravity
  for Satellite Gradiometry Measurements

abstract:
  With continuous advances in related technologies, relativistic gravitational
experiments with orbiting gradiometers becomes feasible, which could naturally
be incorporated into future satellite gravity missions. Tests of Chern-Simons
modified gravity are meaningful since such a modification gives us insights
into (possible) parity-violations in gravitation. In this work, we derive, at
the post-Newtonian level, the new observables of secular gradients from the
non-dynamical Chern-Simons modified gravity, which will greatly improve the
constraint on the mass scale $M_{CS}$ that may be drawn from satellite
gradiometry measurements. For superconducting gradiometers, a strong bound
$M_{CS}\geq 10^{-7}\ eV$ could in principle be obtained. For future optical
gradiometers based on similar technologies from the LISA PathFinder mission, a
even stronger bound $M_{CS}\geq 10^{-6}\sim 10^{-5}\ eV$ might be expected.


title:
Distinguishing number and distinguishing index of lexicographic product
  of two graphs

abstract:
  The distinguishing number (index) $D(G)$ ($D'(G)$) of a graph $G$ is the
least integer $d$ such that $G$ has an vertex labeling (edge labeling) with $d$
labels that is preserved only by a trivial automorphism. The lexicographic
product of two graphs $G$ and $H$, $G[H]$ can be obtained from $G$ by
substituting a copy $H_u$ of $H$ for every vertex $u$ of $G$ and then joining
all vertices of $H_u$ with all vertices of $H_v$ if $uv\in E(G)$. In this paper
we obtain some sharp bounds for the distinguishing number and the
distinguishing index of lexicographic product of two graphs. As consequences,
we prove that if $G$ is a connected graph with a special condition on
automorphism group of $G[G]$ and $D(G)> 1$, then for every natural $k$,
$D(G)\leq D(G^k)\leq D(G)+k-1$, where $G^k=G[G[...]]$. Also we prove that all
lexicographic powers of $G$, $G^k$ ($k\geq 2$) can be distinguished by at most
two edge labels.


title: Basic hypergeometry of supersymmetric dualities

abstract:
  We introduce several new identities combining basic hypergeometric sums and
integrals. Such identities appear in the context of superconformal index
computations for three-dimensional supersymmetric dual theories. We give both
analytic proofs and physical interpretations of the presented identities.


title:
Superior thermal conductivity in suspended bilayer hexagonal boron
  nitride

abstract:
  We reported the basal-plane thermal conductivity in exfoliated bilayer
hexagonal boron nitride h-BN that was measured using suspended prepatterned
microstructures. The h-BN sample suitable for thermal measurements was
fabricated by dry-transfer method, whose sample quality, due to less polymer
residues on surfaces, is believed to be superior to that of PMMA-mediated
samples. The measured room temperature thermal conductivity is around 484
Wm-1K-1(+141 Wm-1K-1/ -24 Wm-1K-1) which exceeds that in bulk h-BN, providing
experimental observation of the thickness-dependent thermal conductivity in
suspended few-layer h-BN.


title:
Production and dynamics of positrons in ultrahigh intensity laser-foil
  interactions

abstract:
  The electron-positron pair production accompanying interaction of a
circularly polarized laser pulse with a foil is studied for laser intensities
higher than $10^{24}$W cm$^{-2}$. The laser energy penetrates into the foil due
to the effect of the relativistic hole-boring. It is demonstrated that the
electron-positron plasma is produced as a result of quantum-electrodynamical
cascading in the field of the incident and reflected laser light in front of
the foil. The incident and reflected laser light makes up the circularly
polarized standing wave in the reference frame of the hole-boring front and the
pair density peaks near the nodes and antinodes of the wave. A model based on
the particle dynamics with radiation reaction effect near the magnetic nodes is
developed. The model predictions are verified by 3D PIC-MC simulations.


title: A WENO-type slope-limiter for a family of piecewise polynomial methods

abstract:
  A new, high-order slope-limiting procedure for the Piecewise Parabolic Method
(PPM) and the Piecewise Quartic Method (PQM) is described. Following a Weighted
Essentially Non-Oscillatory (WENO)-type paradigm, the proposed slope-limiter
seeks to reconstruct smooth, non-oscillatory piecewise polynomial profiles as a
non-linear combination of the natural and monotone-limited PPM and PQM
interpolants. Compared to existing monotone slope-limiting techniques, this new
strategy is designed to improve accuracy at smooth extrema, while controlling
spurious oscillations in the neighbourhood of sharp features. Using the new
slope-limited PPM and PQM interpolants, a high-order accurate
Arbitrary-Lagrangian-Eulerian framework for advection-dominated flows is
constructed, and its effectiveness is examined using a series of one- and
two-dimensional benchmark cases. It is shown that the new WENO-type
slope-limiting techniques offer a significant improvement in accuracy compared
to existing strategies, allowing the PPM- and PQM- based schemes to achieve
fully third- and fifth-order accurate convergence, respectively, for
sufficiently smooth problems.

categories: physics.comp-ph math.NA physics.ao-ph physics.flu-dyn


title: Representations of SU(2) and Jacobi polynomials

abstract:
  This is a tutorial introduction to the representation theory of SU(2) with
emphasis on the occurrence of Jacobi polynomials in the matrix elements of the
irreducible representations. The last section traces the history of the insight
that Jacobi polynomials occur in the representation theory of SU(2).


title: The Cherenkov Telescope Array

abstract:
  The Cherenkov Telescope Array (CTA) is planned to be the next generation
ground based observatory for very high energy (VHE) gamma-ray astronomy.
Gamma-rays provide a powerful insight into the non-thermal universe and
hopefully a unique probe for new physics. Imaging Cherenkov telescopes have
already discovered more than 170 VHE gamma-ray emitters providing plentiful of
valuable data and clearly demonstrating the power of this technique. In spite
of the impressive results there are indications that the known sources
represent only the tip of the iceberg. A major step in sensitivity is needed to
increase the number of detected sources, observe short time-scale variability
and improve morphological studies of extended sources. An extended energy
coverage is advisable to observe far-away extragalactic objects and improve
spectral analysis. CTA aims to increase the sensitivity by an order of
magnitude compared to current facilities, to extend the accessible gamma-ray
energies from a few tens of GeV to a hundred of TeV, and to improve on other
parameters like angular and energy resolution. CTA will provide moreover a full
sky-coverage by featuring an array of imaging atmospheric Cherenkov telescopes
in both hemispheres. This paper presents an overview of the technical design
and summarize the current status of the project. CTA prospects for some key
science topics like the origin of relativistic cosmic particles, the
acceleration mechanisms in extreme environments such as neutron stars and black
holes and searches for Dark Matter are discussed.


title: Ising antiferromagnet on the Archimedean lattices

abstract:
  Geometric frustration effects were studied systematically with the Ising
antiferromagnet on the 11 Archimedean lattices using the Monte-Carlo methods.
The Wang-Landau algorithm for static properties (specific heat and residual
entropy) and the Metropolis algorithm for a freezing order parameter were
adopted. The exact residual entropy was also found. Based on the degree of
frustration and dynamic properties, ground states of them were determined. The
Shastry-Sutherland lattice and the trellis lattice are weakly-frustrated and
have two-dimensional and one-dimensional long-range-ordered ground states,
respectively. The bounce, maple-leaf, and star lattices have the spin ice
phase. The spin liquid phase appears in the triangular and kagom\'e lattices.


title:
Simulations of recoiling black holes: adaptive mesh refinement and
  radiative transfer

abstract:
  (Abridged) We here continue our effort to model the behaviour of matter when
orbiting or accreting onto a generic black hole by developing a new numerical
code employing advanced techniques geared solve the equations of in
general-relativistic hydrodynamics. The new code employs a number of
high-resolution shock-capturing Riemann-solvers and reconstruction algorithms,
exploiting the enhanced accuracy and the reduced computational cost of AMR
techniques. In addition, the code makes use of sophisticated ray-tracing
libraries that, coupled with general-relativistic radiation-transfer
calculations, allow us to compute accurately the electromagnetic emissions from
such accretion flows. We validate the new code by presenting an extensive
series of stationary accretion flows either in spherical or axial symmetry and
performed either in 2D or 3D. In addition, we consider the highly nonlinear
scenario of a recoiling black hole produced in the merger of a supermassive
black hole binary interacting with the surrounding circumbinary disc. In this
way we can present, for the first time, ray-traced images of the shocked fluid
and the light-curve resulting from consistent general-relativistic
radiation-transport calculations from this process. The work presented here
lays the ground for the development of a generic computational infrastructure
employing AMR techniques to deal accurately and self-consistently with
accretion flows onto compact objects. In addition to the accurate handling of
the matter, we provide a self-consistent electromagnetic emission from these
scenarios by solving the associated radiative-transfer problem. While magnetic
fields are presently excluded from our analysis, the tools presented here can
have a number of applications to study accretion flows onto black holes or
neutron stars.


title: From Chio Pivotal Condensation to the Matrix-Tree theorem

abstract:
  We show a determinant identity which generalizes both the Chio pivotal
condensation theorem and the Matrix-Tree theorem.


abstract:
  In this paper we prove the Jawerth-Franke embeddings of Herz-type Besov and
Triebel-Lizorkin spaces. Moreover, we obtain the Jawerth-Franke embeddings of
Besov and Triebel-Lizorkin spaces equipped with power weights. An application
we present new embeddings between Besov and Herz spaces.


title:
Novel approach to measure the leptonic eta(')->mu+mu- decays via charmed
  meson decays

abstract:
  In this article, we propose a novel approach to measure the branching ratios
of the leptonic eta(')-> mu+mu- decays by using charmed meson decays, namely,
D+(s)->pi+ eta(')(->mu+mu-) and D0->K-pi+eta(')(->mu+mu-). We advocate that the
data available at LHCb can already yield a new measurement of Br(eta->mu+mu-)
with accuracy competitive with the current world average. We also estimate that
using the data collected by LHCb between 2015 and 2018 in proton-proton
collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated
luminosity of 5.0/fb, the relative uncertainties to this branching ratio can be
reduced down to ~10%. We also show that the first observation of
Br(eta'->mu+mu-) may be possible with the Upgrade of the LHCb experiment.


title: On conjectures of Andrews and Curtis

abstract:
  It is shown that the original Andrews--Curtis conjecture on balanced
presentations of the trivial group is equivalent to its "cyclic" version in
which, in place of arbitrary conjugations, one can use only cyclic
permutations. This, in particular, proves a satellite conjecture of Andrews and
Curtis made in 1966. We also consider a more restrictive "cancellative" version
of the cyclic Andrews--Curtis conjecture with and without stabilizations and
show that the restriction does not change the Andrews--Curtis conjecture when
stabilizations are allowed. On the other hand, the restriction makes the
conjecture false when stabilizations are not allowed.


title:
J/$\psi$ suppression at forward rapidity in Pb-Pb collisions at
  $\sqrt{s_{{\rm NN}}} = 5.02$ TeV

abstract:
  The inclusive J/$\psi$ production has been studied in Pn-Pb and pp collisions
at the centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}}=5.02$ TeV,
using the ALICE detector at the CERN LHC. The J/$\psi$ meson is reconstructed,
in the centre-of-mass rapidity interval $2.5<y<4$ and in the
transverse-momentum range $p_{\rm T}<12$ GeV/$c$, via its decay to a muon pair.
In this Letter, we present results on the inclusive J/$\psi$ cross section in
pp collisions at $\sqrt{s}=5.02$ TeV and on the nuclear modification factor
$R_{\rm AA}$. The latter is presented as a function of the centrality of the
collision and, for central collisions, as a function of the transverse momentum
$p_{\rm T}$ of the J/$\psi$. The measured $R_{\rm AA}$ values indicate a
suppression of the J/$\psi$ in nuclear collisions and are then compared to our
previous results obtained in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV.
The ratio of the $R_{\rm AA}$ values at the two energies is also computed and
compared to calculations of statistical and dynamical models. The numerical
value of the ratio for central events (0-10\% centrality) is $1.17 \pm 0.04
{\rm{(stat)}}\pm 0.20 {\rm{(syst)}}$. In central events, as a function of
$p_{\rm T}$, a slight increase of $R_{\rm AA}$ with collision energy is visible
in the region $2<p_{\rm T}<6$ GeV/$c$. Theoretical calculations provide a good
description of the measurements, within uncertainties.


title:
Two-qubit gates using adiabatic passage of the Stark-tuned F\"orster
  resonances in Rydberg atoms

abstract:
  We propose schemes of controlled-Z and controlled-NOT gates with ultracold
neutral atoms based on deterministic phase accumulation during double adiabatic
passage of the Stark-tuned F\"{o}rster resonance of Rydberg states. The effect
of deterministic phase accumulation during double adiabatic passage in a
two-level quantum system has been analyzed in detail. Adiabatic rapid passage
using nonlinearly chirped pulses with rectangle intensity profile has been
discussed. Nonlinear time dependence of the energy detuning from the
F\"{o}rster resonance is used to achieve a high fidelity of population transfer
between Rydberg states. Fidelity of two-qubit gates has been studied with an
example of the $90S+96S\to 90P+95P$ Stark-tuned F\"{o}rster resonance in Cs
Rydberg atoms.


title:
Analysis of family-wise error rates in statistical parametric mapping
  using random field theory

abstract:
  This technical report revisits the analysis of family-wise error rates in
statistical parametric mapping - using random field theory - reported in
(Eklund et al., 2015). Contrary to the understandable spin that these sorts of
analyses attract, a review of their results suggests that they endorse the use
of parametric assumptions - and random field theory - in the analysis of
functional neuroimaging data. We briefly rehearse the advantages parametric
analyses offer over nonparametric alternatives and then unpack the implications
of (Eklund et al., 2015) for parametric procedures.


title: Molecular echoes in space and time

abstract:
  Mountain echoes are a well-known phenomenon, where an impulse excitation is
mirrored by the rocks to generate a replica of the original stimulus, often
with reverberating recurrences. For spin echoes in magnetic resonance and
photon echoes in atomic and molecular systems the role of the mirror is played
by a second, time delayed pulse which is able to reverse the ow of time and
recreate the original event. Recently, laser-induced rotational alignment and
orientation echoes were introduced for molecular gases, and discussed in terms
of rotational-phase-space filamentation. Here we present, for the first time, a
direct spatiotemporal analysis of various molecular alignment echoes by means
of coincidence Coulomb explosion imaging. We observe hitherto unreported
spatially rotated echoes, that depend on the polarization direction of the pump
pulses, and find surprising imaginary echoes at negative times.


title: Flux free growth of superconducting FeSe single crystals

abstract:
  We report flux free growth of superconducting FeSe single crystals by an easy
and versatile high temperature melt and slow cooling method for first time. The
room temperature XRD on the surface of the piece of such obtained crystals
showed single 101 plane of Beta-FeSe tetragonal phase. The bulk powder XRD,
being obtained by crushing the part of crystal chunk showed majority tetragonal
and minority FeSe hexagonal crystalline phases. Detailed HRTEM images along
with SAED (selected area electron diffraction) showed the abundance of both
majority and minority FeSe phases. Both transport (RT) and magnetization (MT)
exhibited superconductivity at below around 10K. Interestingly, the
magnetization signal of these crystals is dominated by the magnetism of
minority magnetic phase, and hence the isothermal magnetization (MH) at 4K was
seen to be ferromagnetic (FM) like. Transport (R-T) measurements under magnetic
field showed superconductivity onset at below 12K, and R = 0 (Tc) at 9K.
Superconducting transition temperature (Tc) decreases with applied field to
around 6K at 7Tesla, with dTc/dH of 0.4K/Tesla, giving rise to an Hc2 value of
around 50 Tesla, 30 Tesla and 20 Tesla for Rn = 90, 50 and 10 percent
respectively. FeSe single crystal activation energy is calculated from
Thermally Activated Flux Flow (TAFF) model which is found to decreases with
field.


title:
Effect of the inter-subband spin-orbit interaction on the spin
  transistor operation

abstract:
  We consider the electron transport in the Datta-Das spin transistor within
the two-subband model taking into account the intra- and inter-subband
spin-orbit (SO) interaction and study the influence of the inter-subband SO
coupling on the spin-transistor operation. Starting from the model, in which
the SO coupling constants are treated as parameters, we show that the
inter-subband SO interaction strongly affects the ordinary conductance
oscillations predicted for the transistor with the single occupancy.
Interestingly, we find that even in the absence of the intra-subband SO
interaction, the conductance oscillates as a function of the inter-subband SO
coupling constant. This phenomenon is explained as resulting from the
inter-subband transition with spin-flip. Next, we consider the realistic spin
transistor model based on the gated
Al$_{0.48}$In$_{0.52}$As/Ga$_{0.47}$In$_{0.53}$As double quantum well, for
which the SO coupling constants are determined by the Schr\"{o}dinger-Poisson
approach. We show that the SO coupling constants rapidly change around $V_g=0$,
which is desirable for the spin transistor operation. We demonstrate that for
high electron densities the inter-subband SO interaction starts to play the
dominant role. The strong evidence of this interaction is the reduction of the
conductance for gate voltage $V_g=0$, which leads to the reduction of the
on/off conductance ratio.


title: Fekete points, formation control, and the balancing problem

abstract:
  We study formation control problems. Our approach is to let a group of
systems maximize their pairwise distances whilst bringing them all to a given
submanifold, determining the shape of the formation. The algorithm we propose
allows to initialize the positions of the individual systems in the ambient
space of the given submanifold but brings them to the desired formation
asymptotically in a stable fashion. Our control inherently consists of a
distributed component, maximizing the pairwise distances, and a decentralized
component, asymptotically stabilizing the submanifold. We establish a
graph-theoretical interpretation of the equilibria that our control enforces
and extend our approach to systems living on the special Euclidean group.
Throughout the paper, we illustrate our approach on different examples.


title:
Randomized dynamic programming principle and Feynman-Kac representation
  for optimal control of McKean-Vlasov dynamics

abstract:
  We analyze a stochastic optimal control problem, where the state process
follows a McKean-Vlasov dynamics and the diffusion coefficient can be
degenerate. We prove that its value function V admits a nonlinear Feynman-Kac
representation in terms of a class of forward-backward stochastic differential
equations, with an autonomous forward process. We exploit this probabilistic
representation to rigorously prove the dynamic programming principle (DPP) for
V. The Feynman-Kac representation we obtain has an important role beyond its
intermediary role in obtaining our main result: in fact it would be useful in
developing probabilistic numerical schemes for V. The DPP is important in
obtaining a characterization of the value function as a solution of a
non-linear partial differential equation (the so-called Hamilton-Jacobi-Belman
equation), in this case on the Wasserstein space of measures. We should note
that the usual way of solving these equations is through the Pontryagin maximum
principle, which requires some convexity assumptions. There were attempts in
using the dynamic programming approach before, but these works assumed a priori
that the controls were of Markovian feedback type, which helps write the
problem only in terms of the distribution of the state process (and the control
problem becomes a deterministic problem). In this paper, we will consider
open-loop controls and derive the dynamic programming principle in this most
general case. In order to obtain the Feynman-Kac representation and the
randomized dynamic programming principle, we implement the so-called
randomization method, which consists in formulating a new McKean-Vlasov control
problem, expressed in weak form taking the supremum over a family of equivalent
probability measures. One of the main results of the paper is the proof that
this latter control problem has the same value function V of the original
control problem.


title: Anomalous magnetohydrodynamics in the extreme relativistic domain

abstract:
  The evolution equations of anomalous magnetohydrodynamics are derived in the
extreme relativistic regime and contrasted with the treatment of hydromagnetic
nonlinearities pioneered by Lichnerowicz in the absence of anomalous currents.
In particular we explore the situation where the conventional vector currents
are complemented by the axial-vector currents arising either from the pseudo
Nambu-Goldstone bosons of a spontaneously broken symmetry or because of finite
fermionic density effects. After expanding the generally covariant equations in
inverse powers of the conductivity, the relativistic analog of the magnetic
diffusivity equation is derived in the presence of vortical and magnetic
currents. While the anomalous contributions are generally suppressed by the
diffusivity, they are shown to disappear in the perfectly conducting limit.
When the flow is irrotational, boost-invariant and with vanishing
four-acceleration the corresponding evolution equations are explicitly
integrated so that the various physical regimes can be directly verified.


title: Optical pumping effect in absorption imaging of F=1 atomic gases

abstract:
  We report our study of the optical pumping effect in absorption imaging of
$^{23}$Na atoms in the $F=1$ hyperfine spin states. Solving a set of rate
equations for the spin populations in the presence of a probe beam, we obtain
an analytic expression for the optical signal of the $F=1$ absorption imaging.
Furthermore, we verify the result by measuring the absorption spectra of
$^{23}$Na Bose-Einstein condensates prepared in various spin states with
different probe beam pulse durations. The analytic result can be used in the
quantitative analysis of $F=1$ spinor condensate imaging and readily applied to
other alkali atoms with $I=3/2$ nuclear spin such as $^{87}$Rb.


title: Semantic homophily in online communication: evidence from Twitter

abstract:
  People are observed to assortatively connect on a set of traits. This
phenomenon, termed assortative mixing or sometimes homophily, can be quantified
through assortativity coefficient in social networks. Uncovering the exact
causes of strong assortative mixing found in social networks has been a
research challenge. Among the main suggested causes from sociology are the
tendency of similar individuals to connect (often itself referred as homophily)
and the social influence among already connected individuals. An important
question to researchers and in practice can be tackled, as we present here:
understanding the exact mechanisms of interplay between these tendencies and
the underlying social network structure. Namely, in addition to the mentioned
assortativity coefficient, there are several other static and temporal network
properties and substructures that can be linked to the tendencies of homophily
and social influence in the social network and we herein investigate those.
Concretely, we tackle a computer-mediated \textit{communication network} (based
on Twitter mentions) and a particular type of assortative mixing that can be
inferred from the semantic features of communication content that we term
\textit{semantic homophily}. Our work, to the best of our knowledge, is the
first to offer an in-depth analysis on semantic homophily in a communication
network and the interplay between them. We quantify diverse levels of semantic
homophily, identify the semantic aspects that are the drivers of observed
homophily, show insights in its temporal evolution and finally, we present its
intricate interplay with the communication network on Twitter. By analyzing
these mechanisms we increase understanding on what are the semantic aspects
that shape and how they shape the human computer-mediated communication.


title: The winding of stationary Gaussian processes

abstract:
  This paper studies the winding of a continuously differentiable Gaussian
stationary process $f:\mathbb{R}\to\mathbb{C}$ in the interval $[0,T]$. We give
formulae for the mean and the variance of this random variable. The variance is
shown to always grow at least linearly with $T$, and conditions for it to be
asymptotically linear or quadratic are given. Moreover, we show that if the
covariance function together with its second derivative are in
$L^2(\mathbb{R})$, then the winding obeys a central limit theorem. These
results correspond to similar results for zeroes of real-valued stationary
Gaussian functions by Cuzick, Slud and others.


title:
Isogeometric Simulation of Lorentz Detuning in Superconducting
  Accelerator Cavities

abstract:
  Cavities in linear accelerators suffer from eigenfrequency shifts due to
mechanical deformation caused by the electromagnetic radiation pressure, a
phenomenon known as Lorentz detuning. Estimating the frequency shift up to the
needed accuracy by means of standard Finite Element Methods, is a complex task
due to the non exact representation of the geometry and due to the necessity
for mesh refinement when using low order basis functions. In this paper, we use
Isogeometric Analysis for discretising both mechanical deformations and
electromagnetic fields in a coupled multiphysics simulation approach. The
combined high-order approximation of both leads to high accuracies at a
substantially lower computational cost.


title:
Magnetizability of the relativistic hydrogenlike atom in an arbitrary
  discrete energy eigenstate: Application of the Sturmian expansion of the
  generalized Dirac-Coulomb Green function

abstract:
  The Sturmian expansion of the generalized Dirac--Coulomb Green function
[R.\/~Szmytkowski, J.\ Phys.\ B \textbf{30}, 825 (1997); \textbf{30}, 2747(E)
(1997)] is exploited to derive a closed-form expression for the magnetizability
of the relativistic one-electron atom in an arbitrary discrete state, with a
point-like, spinless and motionless nucleus of charge $Ze$. The result has the
form of a double finite sum involving the generalized hypergeometric functions
${}_3F_2$ of the unit argument. Our general expression agrees with formulas
obtained analytically earlier by other authors for some particular states of
the atom. We present also numerical values of the magnetizability for some
excited states of selected hydrogenlike ions with $1 \leqslant Z \leqslant 137$
and compare them with data available in the literature.


title:
The fractional Hartree equation without the Ambrosetti-Rabinowitz
  condition

abstract:
  We consider a class of pseudo-relativistic Hartree equations in presence of
general nonlinearities not satisfying the Ambrosetti-Rabinowitz condition.
Using variational methods based on critical point theory, we show the existence
of two non trivial signed solutions, one positive and one negative.


title: Bernoulli and tail-dependence compatibility

abstract:
  The tail-dependence compatibility problem is introduced. It raises the
question whether a given $d\times d$-matrix of entries in the unit interval is
the matrix of pairwise tail-dependence coefficients of a $d$-dimensional random
vector. The problem is studied together with Bernoulli-compatible matrices,
that is, matrices which are expectations of outer products of random vectors
with Bernoulli margins. We show that a square matrix with diagonal entries
being 1 is a tail-dependence matrix if and only if it is a Bernoulli-compatible
matrix multiplied by a constant. We introduce new copula models to construct
tail-dependence matrices, including commonly used matrices in statistics.


title:
Exciton-phonon relaxation bottleneck and radiative decay of thermal
  exciton reservoir in two-dimensional materials

abstract:
  We study exciton radiative decay in a two-dimensional material, taking into
account large thermal population in the non-radiative states, from which
excitons are scattered into the radiative states by acoustic phonons. We find
an analytical solution of the kinetic equation for the non-equilibrium
distribution function of excitons in the radiative states. Our estimates for
bright excitons in transition metal dichalcogenides indicate a strong depletion
of radiative state population due to insufficient exciton-phonon scattering
rate at low temperatures.


title: A dirty integration of Leibniz algebras

abstract:
  In this article, we present an integration of any real finite-dimensional
Leibniz algebra as a Lie rack which reduces in the particular case of a Lie
algebra to the ordinary connected simply connected Lie group. The construction
is not functorial.


title:
Collective dynamics of chemically active particles trapped at a fluid
  interface

abstract:
  Chemically active colloids generate changes in the chemical composition of
their surrounding solution and thereby induce flows in the ambient fluid which
affect their dynamical evolution. Here we study the many-body dynamics of a
monolayer of active particles trapped at a fluid-fluid interface. To this end
we consider a mean-field model which incorporates the direct pair interaction
(including also the capillary interaction which is caused specifically by the
interfacial trapping) as well as the effect of hydrodynamic interactions
(including the Marangoni flow induced by the response of the interface to the
chemical activity). The values of the relevant physical parameters for typical
experimental realizations of such systems are estimated and various scenarios,
which are predicted by our approach for the dynamics of the monolayer, are
discussed. In particular, we show that the chemically-induced Marangoni flow
can prevent the clustering instability driven by the capillary attraction.


title:
Pazy's fixed point theorem with respect to the partial order in
  uniformly convex Banach spaces

abstract:
  In this paper, the Pazy's Fixed Point Theorems of monotone
$\alpha-$nonexpansive mapping $T$ are proved in a uniformly convex Banach space
$E$ with the partial order "$\leq$". That is, we obtain that the fixed point
set of $T$ with respect to the partial order "$\leq$" is nonempty whenever the
Picard iteration $\{T^nx_0\}$ is bounded for some initial point $x_0$ with
$x_0\leq Tx_0$ or $Tx_0\leq x_0$. When restricting the demain of $T$ to the
cone $P$, a monotone $\alpha-$nonexpansive mapping $T$ has at least a fixed
point if and only if the Picard iteration $\{T^n0\}$ is bounbed. Furthermore,
with the help of the properties of the normal cone $P$, the weakly and strongly
convergent theorems of the Picard iteration $\{T^nx_0\}$ are showed for finding
a fixed point of $T$ with respect to the partial order "$\leq$" in uniformly
convex ordered Banach space.


title: Weak measurements and supraluminal communication

abstract:
  There is suggested a version of the experiment with a correlated pair of
particles in the entangled state. The experiment demonstrates that, in the case
of weak and/or non-demolition measurements of one of the particles, it is
possible to transmit information with a speed not limited by velocity of light.


title:
Strain-driven criticality underlies nonlinear mechanics of fibrous
  networks

abstract:
  Networks with only central force interactions are floppy when their average
connectivity is below an isostatic threshold. Although such networks are
mechanically unstable, they can become rigid when strained. It was recently
shown that the transition from floppy to rigid states as a function of simple
shear strain is continuous, with hallmark signatures of criticality (Nat. Phys.
12, 584 (2016)). The nonlinear mechanical response of collagen networks was
shown to be quantitatively described within the framework of such mechanical
critical phenomenon. Here, we provide a more quantitative characterization of
critical behavior in subisostatic networks. Using finite size scaling we
demonstrate the divergence of strain fluctuations in the network at
well-defined critical strain. We show that the characteristic strain
corresponding to the onset of strain stiffening is distinct from but related to
this critical strain in a way that depends on critical exponents. We confirm
this prediction experimentally for collagen networks. Moreover, we find that
the apparent critical exponents are largely independent of the spatial
dimensionality. In a highly simplified computational model of network dynamics,
we also observe critical slowing down in the vicinity of the critical strain.
With subisostaticity as the only required condition, strain-driven criticality
is expected to be a general feature of biologically relevant fibrous networks.


title: On the M\"ossbauer effect and the rigid recoil question

abstract:
  Various theories for the M\"ossbauer rigid-recoil effect, which enables a
crystal to absorb momentum but not appreciable energy, are compared. These
suggest that the recoil may not be instantaneous, and that the recoil time
could be used to distinguish between them. An experiment is proposed to measure
this time. The idea is to use a small sphere whose outer surface is coated with
an electrically charged M\"ossbauer-active element, and then to measure the
amount of energy lost due to Bremmsstrahlung during the recoil of this sphere
when a M\"ossbauer event occurs. As the energy radiated is proportional to the
square of the acceleration from Larmor's formula, the amount of energy so
radiated varies inversely proportional to the recoil time, and proportional to
the charge squared. Although this energy is quite small, it can in principle be
measured with the extreme sensitivity available in M\"ossbauer experiments. It
is found that the most information would be gained with more long-lived isomers
such as Rhodium-103m as the M\"ossbauer agent, and that correction terms to
Larmor's formula need to be considered due to the finite radius of a small
particle, and some of these corrections are included in the paper. These
corrections are taken from the extensive literature on radiating spherical
shells which were developed to analyze the Abraham-Lorentz model for a
classical charged particle. This problem is interesting because a perfectly
rigid crystal seems to pose questions about relativity, and because the
M\"ossbauer effect is a phenomenon where the solid-state environment
dramatically influences the probability of a nuclear process. Moreover, if the
experiment proposed can measure the recoil time, then such measurements might
provide a new class of analytical methods for material science and chemistry.


title: Quasi-Optimal Regulation of FlowNetworks with Input Constraints

abstract:
  In this work we consider a flow network for which the goal is to solve a
practical optimal regulation problem in the presence of input saturation. Based
on Lyapunov arguments we propose distributed controllers which guarantee global
convergence to an arbitrarily small neighborhood of the desired optimal steady
state while fulfilling the constraints. As a case study we apply our
distributed controller to a district heating network.


title:
The centripetal force law and the equation of motion for a particle on a
  curved hypersurface

abstract:
  It is pointed out that the current form of extrinsic equation of motion for a
particle constrained to remain on a hypersurface is in fact a half-finished
version for it is established without regard to the fact that the particle can
never depart from the geodesics on the surface. Once the fact be taken into
consideration, the equation takes that same form as that for centripetal force
law, provided that the symbols are re-interpreted so that the law is applicable
for higher dimensions. The controversial issue of constructing operator forms
of these equations is addressed, and our studies show the quantization of
constrained system based on the extrinsic equation of motion is favorable.


title:
A Quillen adjunction between algebras and operads, Koszul duality, and
  the Lagrange inversion formula

abstract:
  We define, for a somewhat standard forgetful functor from nonsymmetric
operads to weight graded associative algebras, two functorial "enveloping
operad" functors, the right inverse and the left adjoint of the forgetful
functor. Those functors turn out to be related by operadic Koszul duality, and
that relationship can be utilised to provide examples showing limitations of
two standard tools of the Koszul duality theory. We also apply these functors
to get a homotopical algebra proof of the Lagrange inversion formula.


title:
Sufficient minimal model for DNA denaturation: Integration of harmonic
  scalar elasticity and bond energies

abstract:
  We study DNA denaturation by integrating elasticity -- as described by the
Gaussian network model -- with bond binding energies, distinguishing between
different base-pair and stacking energies. We use exact calculation, within the
model, of the Helmholtz free-energy of any partial denaturation state, which
implies that the entropy of all formed bubbles ("loops") is accounted for.
Considering base-pair bond removal single events, the bond designated for
opening is chosen by minimizing the free-energy difference for the process,
over all remaining base-pair bonds. Despite of its great simplicity, for
several known DNA sequences our results are in accord with available
theoretical and experimental studies. Moreover, we report free-energy profiles
along the denaturation pathway, which allow to detect stable or meta-stable
partial denaturation states, composed of "bubbles", as local free-energy minima
separated by barriers. Our approach allows to study very long DNA strands with
commonly available computational power, as we demonstrate for a few random
sequences in the range 200-800 base-pairs. For the latter we also elucidate the
self-averaging property of the system. Implications for the well known
breathing dynamics of DNA are elucidated.


title: Coset spaces and Einstein manifolds with l-conformal Galilei symmetry

abstract:
  The group theoretic construction is applied to construct a novel dynamical
realization of the $l$--conformal Galilei group in terms of geodesic equations
on the coset space. A peculiar feature of the geodesics is that all their
integrals of motion, including the accelerations, are functionally independent.
The analysis in the recent work [Phys. Lett. B 754 (2016) 249] is extended to
construct the Einstein metrics with the $l$--conformal Galilei isometry group.


title: A center transversal theorem for an improved Rado depth

abstract:
  A celebrated result of Dol'nikov, and of \v{Z}ivaljevi\'c and Vre\'cica,
asserts that for every collection of $m$ measures $\mu_1,\dots,\mu_m$ on the
Euclidean space $\mathbb R^{n + m - 1}$ there exists a projection onto an
$n$-dimensional vector subspace $\Gamma$ with a point in it at depth at least
$\tfrac{1}{n + 1}$ with respect to each associated $n$-dimensional marginal
measure $\Gamma_*\mu_1,\dots,\Gamma_*\mu_m$.
  In this paper we consider a natural extension of this result and ask for a
minimal dimension of a Euclidean space in which one can require that for any
collection of $m$ measures there exists a vector subspace $\Gamma$ with a point
in it at depth slightly greater than $\tfrac{1}{n + 1}$ with respect to each
$n$-dimensional marginal measure. In particular, we prove that if the required
depth is $\tfrac{1}{n + 1} + \tfrac{1}{3(n + 1)^3}$ then the increase in the
dimension of the ambient space is a linear function in both $m$ and $n$.


title: Weak embeddings of posets to the Boolean lattice

abstract:
  The goal of this paper is to prove that several variants of deciding whether
a poset can be (weakly) embedded into a small Boolean lattice, or to a few
consecutive levels of a Boolean lattice, are NP-complete, answering a question
of Griggs and of Patkos. As an equivalent reformulation of one of these
problems, we also derive that it is NP-complete to decide whether a given graph
can be embedded to the two middle levels of some hypercube.


title: Hafnium carbide formation in oxygen deficient hafnium oxide thin films

abstract:
  On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO$_{2-x}$)
contaminated with adsorbates of carbon oxides, the formation of hafnium carbide
(HfC$_x$) at the surface during vacuum annealing at temperatures as low as 600
{\deg}C is reported. Using X-ray photoelectron spectroscopy the evolution of
the HfC$_x$ surface layer related to a transformation from insulating into
metallic state is monitored in situ. In contrast, for fully stoichiometric
HfO$_2$ thin films prepared and measured under identical conditions, the
formation of HfC$_x$ was not detectable suggesting that the enhanced adsorption
of carbon oxides on oxygen deficient films provides a carbon source for the
carbide formation. This shows that a high concentration of oxygen vacancies in
carbon contaminated hafnia lowers considerably the formation energy of hafnium
carbide. Thus, the presence of a sufficient amount of residual carbon in
resistive random access memory devices might lead to a similar carbide
formation within the conducting filaments due to Joule heating.


title: Ising antiferromagnet on the 2-uniform lattices

abstract:
  The antiferromagnetic Ising model is investigated on the 20 2-uniform
lattices using the Monte-Carlo method based on the Wang-Landau algorithm and
the Metropolis algorithm to study the geometric frustration effect
systematically. Based on the specific heat, the residual entropy, and the
Edwards-Anderson freezing order parameter, the ground states of them were
determined. In addition to the long-range-ordered phase and the spin ice phase
found in the Archimedean lattices, two more phases were found. The partial
long-range order is long-range order with exceptional disordered sites, which
gives extensive residual entropy. In the partial spin ice phase, the partial
freezing phenomenon appears: Majority of sites are frozen without long-range
order, but the other sites are fluctuating even at zero temperature. The spin
liquid ground state was not found in the 2-uniform lattices.


title: States and synaptic algebras

abstract:
  Different versions of the notion of a state have been formulated for various
so-called quantum structures. In this paper, we investigate the interplay among
states on synaptic algebras and on its sub-structures. A synaptic algebra is a
generalization of the partially ordered Jordan algebra of all bounded
self-adjoint operators on a Hilbert space. The paper culminates with a
characterization of extremal states on a commutative generalized Hermitian
algebra, a special kind of synaptic algebra.


title: The snapping out Brownian motion

abstract:
  We give a probabilistic representation of a one-dimensional diffusion
equation where the solution is discontinuous at $0$ with a jump proportional to
its flux. This kind of interface condition is usually seen as a semi-permeable
barrier. For this, we use a process called here the snapping out Brownian
motion, whose properties are studied. As this construction is motivated by
applications, for example, in brain imaging or in chemistry, a simulation
scheme is also provided.


title:
Large scale opacity fluctuations in the Lyman alpha forest: evidence for
  QSOs dominating the ionising UV background at z ~ 5.5-6 ?

abstract:
  Lyman-alpha forest data probing the post-reionization Universe shows
surprisingly large opacity fluctuations over rather large ($\ge$50 comoving
Mpc/h) spatial scales. We model these fluctuations using a hybrid approach
utilizing the large volume Millennium simulation to predict the spatial
distribution of QSOs combined with smaller scale full hydrodynamical simulation
performed with RAMSES and post-processed with the radiative transfer code ATON.
We produce realictic mock absorption spectra that account for the contribution
of galaxies and QSOs to the ionising UV background. This improved models
confirm our earlier findings that a significant ($\ge$50%) contribution of
ionising photons from QSOs can explain the large reported opacity fluctuations
on large scales. The inferred QSO luminosity function is thereby consistent
with recent estimates of the space density of QSOs at this redshift. Our
simulations still somewhat struggle, however, to reproduce the very long (110
comoving Mpc/h) high opacity absorption through observed in ULAS J0148+0600,
perhaps suggesting an even later end of reionization than assumed in our
previously favoured model. Medium-deep/medium area QSO surveys as well as
targeted searches for the predicted strong transverse QSO proximity effect
whould illuminate the origin of the observed large scale opacity fluctuations.
They would allow to substantiate whether UV fluctuations due to QSO are indeed
primarily responsible, or whether significant contributions from other recently
proposed mechansims such as large scale fluctuations in temperature and mean
free path (even in the absence of rare bright sources) are required.


title: Information integration from distributed threshold-based interactions

abstract:
  We consider a collection of distributed units that interact with one another
through the sending of messages. Each message carries a positive ($+1$) or
negative ($-1$) tag and causes the receiving unit to send out messages as a
function of the tags it has received and a threshold. This simple model
abstracts some of the essential characteristics of several systems used in the
field of artificial intelligence, and also of biological systems epitomized by
the brain. We study the integration of information inside a temporal window as
the model's dynamics unfolds. We quantify information integration by the total
correlation, relative to the window's duration ($w$), of a set of random
variables valued as a function of message arrival. Total correlation refers to
the rise of information gain above and beyond that which the units already
achieve individually, being therefore related to consciousness studies in some
models. We report on extensive computational experiments that explore the
interrelations of the model's parameters (two probabilities and the threshold),
highlighting relevant scenarios of message traffic and how they impact the
behavior of total correlation as a function of $w$. We find that total
correlation can occur at significant fractions of the maximum possible value
and provide semi-analytical results on the message-traffic characteristics
associated with values of $w$ for which it peaks. We then reinterpret the
model's parameters in terms of the current best estimates of some quantities
pertaining to cortical structure and dynamics. We find the resulting
possibilities for best values of $w$ to be well aligned with the time frames
within which percepts are thought to be processed and eventually rendered
conscious.


title:
A Preliminary Mathematical Model for the Dynamic Transmission of Dengue,
  Chikungunya and Zika

abstract:
  Aedes aegypti is a known vector of Dengue, Chikungunya and Zika and the goal
of this study is to propose the first mathematical model to describe the
dynamic transmission of these three diseases. We present two preliminary models
that consist of the SEIR model for the human populations and an SEI model for
the vector to describe (a) the single transmission dynamics of dengue,
Chikungunya or Zika, and (b) any possible coinfection between two diseases in
the same population. In order to do that, we obtain an analytical solution of
the system of 17 and 30 coupled differential equations for each model
respectively, and later obtain the eigenvalues by analyzing the Jacobian matrix
in order to begin the development of a surveillance system to prevent the
spread of these three diseases.


title: Magnetic ratchet effect in bilayer graphene

abstract:
  We consider the orbital effect of an in-plane magnetic field on electrons in
bilayer graphene, deriving linear-in-field contributions to the low-energy
Hamiltonian arising from the presence of either skew interlayer coupling or
interlayer potential asymmetry, the latter being tunable by an external
metallic gate. To illustrate the relevance of such terms, we consider the
ratchet effect in which a dc current results from the application of an
alternating electric field in the presence of an in-plane magnetic field and
inversion-symmetry breaking. By comparison with recent experimental
observations in monolayer graphene [C. Drexler et al., Nature Nanotech. 8, 104
(2013)], we estimate that the effect in bilayer graphene can be two orders of
magnitude greater than that in monolayer, illustrating that the bilayer is an
ideal material for the realization of optoelectronic effects that rely on
inversion-symmetry breaking.


title: Dynamics of a quantum two-state system in a linearly driven quantum bath

abstract:
  When an open quantum system is driven by an external time-dependent force,
the coupling of the driving to the central system is usually included whereas
the impact of the driving field on the bath is neglected. We investigate the
effect of a quantum bath of linearly driven harmonic oscillators on the
relaxation dynamics of a quantum two-level system which itself is not directly
driven. In particular, we calculate the frequency-dependent response of the
system when the bath is subject to a Dirac and a Gaussian driving-pulse. We
show that a time-retarded effective force on the system is induced by the
driven bath which depends on the full history of the perturbation and the
spectral characteristics of the underlying bath. In particular, when a
structured Ohmic bath with a pronounced Lorentzian peak is considered, the
dynamical response of the system to a driven bath is qualitatively different as
compared to the undriven bath. Specifically, additional resonances appear which
can be directly associated to a Jaynes-Cummings-like effective energy spectrum.


title: Robust Spin Squeezing Preservation in Photonic Crystal Cavities

abstract:
  We show that the robust spin squeezing preservation can be achieved by
utilizing detuning modification for an ensemble of N separate two-level atoms
embedded in photonic crystal cavities (PCC). In particular, we explore the
different dynamical behaviors of spin squeezing between isotropic and
anisotropic PCC cases when the atomic frequency is inside the band gap. In both
cases, it is shown that the robust preservation of spin squeezing is completely
determined by the formation of bound states. Intriguingly, we find that unlike
the isotropic case where steady-state spin squeezing varies smoothly when the
atomic frequency moves from the inside to the outside band edge, a sudden
transition occurs for the anisotropic case. The present results may be of
direct importance for, e.g., quantum metrology in open quantum systems.


title: The tennis racket effect in a three-dimensional rigid body

abstract:
  We propose a complete theoretical description of the tennis racket effect,
which occurs in the free rotation of a three-dimensional rigid body. This
effect is characterized by a flip ($\pi$- rotation) of the head of the racket
when a full ($2\pi$) rotation around the unstable inertia axis is considered.
We describe the asymptotics of the phenomenon and conclude about the robustness
of this effect with respect to the values of the moments of inertia and the
initial conditions of the dynamics. This shows the generality of this geometric
property which can be found in a variety of rigid bodies. A simple analytical
formula is derived to estimate the twisting effect in the general case.
Different examples are discussed.


title:
A construction of a large family of commuting pairs of integrable
  symplectic birational 4-dimensional maps

abstract:
  We give a construction of completely integrable 4-dimensional Hamiltonian
systems with cubic Hamilton functions. Applying to the corresponding pairs of
commuting quadratic Hamiltonian vector fields the so called Kahan-Hirota-Kimura
discretization scheme, we arrive at pairs of birational 4-dimensional maps. We
show that these maps are symplectic with respect to a symplectic structure that
is a perturbation of the standard symplectic structure on $\mathbb R^4$, and
possess two independent integrals of motion, which are perturbations of the
original Hamilton functions. Thus, these maps are completely integrable in the
Liouville-Arnold sense. Moreover, under a suitable normalization of the
original pairs of vector fields, the pairs of maps commute and share the
invariant symplectic structure and the two integrals of motion.


title:
Temperature dependence of Er3+ ionoluminescence and photoluminescence in
  Gd2O3:Bi nanopowder

abstract:
  Ionoluminescence (IL) and photoluminescence (PL) of trivalent erbium ions
(Er3+) in Gd2O3 nanopowder host activated with Bi3+ ions has been studied in
order to establish the link between changes in luminescent spectra and
temperature of the sample material. IL measurements have been performed with
H2+ 100 keV ion beam bombarding the target material for a few seconds, while PL
spectra have been collected for temperatures ranging from 20 to 700{\deg}C. The
PL data was used as a reference in determining the temperature corresponding to
IL spectra. The collected data enabled the definition of empirical formula
based on the Boltzmann distribution, which allows the temperature to be
determined with a maximum sensitivity of 9.7 x 10-3 {\deg}C-1. The analysis of
the Er3+ energy level structure in terms of tendency of the system to stay in
thermal equilibrium, explained different behaviors of the lines intensities.
This work led to the conclusion that temperature changes during ion excitation
can be easily defined with separately collected PL spectra. The final result,
which is empirical formula describing dependence of fluorescence intensity
ratio on temperature, raises the idea of an application of method in
temperature control, during processes like ion implantation and some nuclear
applications.


title: Reconstruction of $n$-dimensional convex bodies from surface tensors

abstract:
  In this paper, we derive uniqueness and stability results for surface
tensors. Further, we develop two algorithms that reconstruct shape of
$n$-dimensional convex bodies. One algorithm requires knowledge of a finite
number of surface tensors, whereas the other algorithm is based on noisy
measurements of a finite number of harmonic intrinsic volumes. The derived
stability results ensure consistency of the two algorithms. Examples that
illustrate the feasibility of the algorithms are presented.


title: Hot dense magnetized ultrarelativistic spinor matter in a slab

abstract:
  Properties of hot dense ultrarelativistic spinor matter in a slab of finite
width, placed in a transverse uniform magnetic field, are studied. The
admissible set of boundary conditions is determined by the requirement that
spinor matter be confined inside the slab. In thermal equilibrium, the chiral
separation effect in the slab is shown to depend on both temperature and
chemical potential; this is distinct from the unrealistic case of the magnetic
field filling the unbounded (infinite) medium, when the effect is temperature
independent. In the realistic case of the slab, a stepwise behaviour of the
axial current density at zero temperature is smoothed out as temperature
increases, turning into a linear behaviour at infinitely large temperature. A
choice of boundary conditions can facilitate either augmentation or attenuation
of the chiral separation effect; in particular, the effect can persist even at
zero chemical potential, if temperature is finite. Thus the boundary condition
can serve as a source that is additional to the spinor matter density.

categories: hep-th astro-ph.HE cond-mat.mes-hall math-ph math.MP quant-ph


title: The homotopy sequence for regular singular stratified bundles

abstract:
  A separable, proper morphism of varieties with geometrically connected fibers
induces a homotopy exact sequence relating the \'etale fundamental groups of
source, target and fiber. Extending work of dos Santos, we prove the existence
of an analogous homotopy exact sequence for fundamental group schemes
classifying regular singular stratified bundles, under the additional
assumption that the morphism in question can be (partially) compactified to a
log smooth morphism.


title: PDF4LHC recommendations for Run II

abstract:
  The interpretation of LHC measurements requires a careful estimate of various
sources of uncertainties that affect theoretical calculations. In this
contribution, we present the PDF4LHC Working Group recommendations for the
usage of sets of parton distribution functions (PDFs) at the LHC Run II. We
review the construction and validation of the PDF4LHC15 combined sets, and
study some of their phenomenological implications. We also address some recent
criticism of these recommendations.


title: Morita's trace maps on the group of homology cobordisms

abstract:
  Morita introduced in 2008 a 1-cocycle on the group of homology cobordisms of
surfaces with values in an infinite-dimensional vector space. His 1-cocycle
contains all the "traces" of Johnson homomorphisms which he introduced fifteen
years earlier in his study of the mapping class group. In this paper, we
propose a new version of Morita's 1-cocycle based on a simple and explicit
construction. Our 1-cocycle is proved to satisfy several fundamental
properties, including a connection with the Magnus representation and the LMO
homomorphism. As an application, we show that the rational abelianization of
the group of homology cobordisms is non-trivial. Besides, we apply some of our
algebraic methods to compare two natural filtrations on the automorphism group
of a finitely-generated free group.


title:
Combinatorial Sums $\sum_{k\equiv r(\mbox{mod } m)}{n\choose k}a^k$ and
  Lucas Quotients

abstract:
  In this paper, we study the combinatorial sum $$\sum_{k\equiv r(\mbox{mod
}m)}{n\choose k}a^k.$$ By studying this sum, we obtain new congruences for
Lucas quotients of two infinite families of Lucas sequences. Only for three
Lucas sequences, there are such known results.


title: The Dulmage-Mendelsohn Decomposition for $b$-Matchings

abstract:
  We establish the theory of the Dulmage-Mendelsohn decomposition for
$b$-matchings. The original Dulmage-Mendelsohn decomposition is a classical
canonical decomposition of bipartite graphs, which describes the structures of
the maximum $1$-matchings and the dual optimizers, i.e., the minimum vertex
covers. In this paper, we develop analogical properties, and thus obtain the
structure of the maximum $b$-matchings and characterizes the family of
$b$-verifying set.


title:
Two-dimensional Josephson vortex lattice and anomalously slow decay of
  the Fraunhofer oscillations in a ballistic SNS junction with a warped Fermi
  surface

abstract:
  $ $The critical current of a Josephson junction is an oscillatory function of
the enclosed magnetic flux $\Phi$, because of quantum interference modulated
with periodicity $h/2e$. We calculate these Fraunhofer oscillations in a
two-dimensional (2D) ballistic superconductor--normal-metal--superconductor
(SNS) junction. For a Fermi circle the amplitude of the oscillations decays as
$1/\Phi$ or faster. If the Fermi circle is strongly warped, as it is on a
square lattice near the band center, we find that the amplitude decays slower
$\propto 1/\sqrt\Phi$ when the magnetic length $l_m=\sqrt{\hbar/eB}$ drops
below the separation $L$ of the NS interfaces. The crossover to the slow decay
of the critical current is accompanied by the appearance of a 2D array of
current vortices and antivortices in the normal region, which form a bipartite
rectangular lattice with lattice constant $\simeq l_m^2/L$. The 2D lattice
vanishes for a circular Fermi surface, when only the usual single row of
Josephson vortices remains.


title: Chernoff Index for Cox Test of Separate Parametric Families

abstract:
  The asymptotic efficiency of a generalized likelihood ratio test proposed by
Cox is studied under the large deviations framework for error probabilities
developed by Chernoff. In particular, two separate parametric families of
hypotheses are considered [Cox, 1961, 1962]. The significance level is set such
that the maximal type I and type II error probabilities for the generalized
likelihood ratio test decay exponentially fast with the same rate. We derive
the analytic form of such a rate that is also known as the Chernoff index
[Chernoff, 1952], a relative efficiency measure when there is no preference
between the null and the alternative hypotheses. We further extend the analysis
to approximate error probabilities when the two families are not completely
separated. Discussions are provided concerning the implications of the present
result on model selection.


title: Positive solutions for a class of quasilinear singular elliptic systems

abstract:
  In this paper we establish the existence of two positive solutions for a
class of quasilinear singular elliptic systems. The main tools are sub and
supersolution method and Leray-Schauder Topological degree.


title: Quantum quenching of radiation losses in short laser pulses

abstract:
  Accelerated charges radiate, and therefore must lose energy. The impact of
this energy loss on particle motion, called radiation reaction, becomes
significant in intense-laser matter interactions, where it can reduce collision
energies, hinder particle acceleration schemes, and is seemingly unavoidable.
Here we show that this common belief breaks down in short laser pulses, and
that energy losses and radiation reaction can be controlled and effectively
switched off by appropriate tuning of the pulse length. This "quenching" of
emission is impossible in classical physics, but becomes possible in QED due to
the discrete nature of quantum emissions.


title:
On the Stability and the Exponential Concentration of Extended
  Kalman-Bucy filters

abstract:
  The exponential stability and the concentration properties of a class of
extended Kalman-Bucy filters are analyzed. New estimation concentration
inequalities around partially observed signals are derived in terms of the
stability properties of the filters. These non asymptotic exponential
inequalities allow to design confidence interval type estimates in terms of the
filter forgetting properties with respect to erroneous initial conditions. For
uniformly stable signals, we also provide explicit non-asymptotic estimates for
the exponential forgetting rate of the filters and the associated stochastic
Riccati equations w.r.t. Frobenius norms. These non asymptotic exponential
concentration and quantitative stability estimates seem to be the first results
of this type for this class of nonlinear filters. Our techniques combine
$\chi$-square concentration inequalities and Laplace estimates with spectral
and random matrices theory, and the non asymptotic stability theory of
quadratic type stochastic processes.


title:
Metal-insulator transition and tunable Dirac-cone surface state in the
  topological insulator TlBi1-xSbxTe2 studied by angle-resolved photoemission

abstract:
  We report a systematic angle-resolved photoemission spectroscopy on
topological insulator (TI) TlBi1-xSbxTe2 which is bulk insulating at 0.5 < x <
0.9 and undergoes a metal-insulator-metal transition with the Sb content x. We
found that this transition is characterized by a systematic hole doping with
increasing x, which results in the Fermi-level crossings of the bulk conduction
and valence bands at x~ 0 and x~1, respectively. The Dirac point of the
topological surface state is gradually isolated from the valence-band edge,
accompanied by a sign reversal of Dirac carriers. We also found that the Dirac
velocity is the largest among known solid-solution TI systems. The
TlBi1-xSbxTe2 system thus provides an excellent platform for Dirac-cone
engineering and device applications of TIs.


title: Wireless Coded Caching: A Topological Perspective

abstract:
  We explore the performance of coded caching in a SISO BC setting where some
users have higher link capacities than others. Focusing on a binary and fixed
topological model where strong links have a fixed normalized capacity 1, and
where weak links have reduced normalized capacity $\tau<1$, we identify --- as
a function of the cache size and $\tau$ --- the optimal throughput performance,
within a factor of at most 8. The transmission scheme that achieves this
performance, employs a simple form of interference enhancement, and exploits
the property that weak links attenuate interference, thus allowing for
multicasting rates to remain high even when involving weak users. This approach
ameliorates the negative effects of uneven topology in multicasting, now
allowing all users to achieve the optimal performance associated to $\tau=1$,
even if $\tau$ is approximately as low as $\tau\geq 1-(1-w)^g$ where $g$ is the
coded-caching gain, and where $w$ is the fraction of users that are weak. This
leads to the interesting conclusion that for coded multicasting, the weak users
need not bring down the performance of all users, but on the contrary to a
certain extent, the strong users can lift the performance of the weak users
without any penalties on their own performance. Furthermore for smaller ranges
of $\tau$, we also see that achieving the near-optimal performance comes with
the advantage that the strong users do not suffer any additional delays
compared to the case where $\tau = 1$.


title:
Fermiology of possible topological superconductor Tl0.5Bi2Te3 derived
  from hole-doped topological insulator

abstract:
  We have performed angle-resolved photoemission spectroscopy on Tl0.5Bi2Te3, a
possible topological superconductor derived from Bi2Te3. We found that the bulk
Fermi surface consists of multiple three-dimensional hole pockets surrounding
the Z point, produced by the direct hole doping into the valence band. The
Dirac-cone surface state is well isolated from the bulk bands, and the surface
chemical potential is variable in the entire band-gap range. Tl0.5Bi2Te3 thus
provides an excellent platform to realize two-dimensional topological
superconductivity through a proximity effect from the superconducting bulk.
Also, the observed Fermi-surface topology provides a concrete basis for
constructing theoretical models for bulk topological superconductivity in
hole-doped topological insulators.


title:
On exponential type entire functions without zeros in the open lower
  half-plane

abstract:
  We obtain sufficient conditions for an exponential type entire function not
to have zeros in the open lower half-plane. An exact inequality containing the
real and imaginary parts of such functions and their derivatives restricted to
the real axis is deduced. A connection is established to the positive definite
functions.


title:
On the stability and the uniform propagation of chaos of a class of
  Extended Ensemble Kalman-Bucy filters

abstract:
  This article is concerned with the exponential stability and the uniform
propagation of chaos properties of a class of Extended Ensemble Kalman-Bucy
filters with respect to the time horizon. This class of nonlinear filters can
be interpreted as the conditional expectations of nonlinear McKean Vlasov type
diffusions with respect to the observation process. In contrast with more
conventional Langevin nonlinear drift type processes, the mean field
interaction is encapsulated in the covariance matrix of the diffusion. The main
results discussed in the article are quantitative estimates of the exponential
stability properties of these nonlinear diffusions. These stability properties
are used to derive uniform and non asymptotic estimates of the propagation of
chaos properties of Extended Ensemble Kalman filters, including exponential
concentration inequalities. To our knowledge these results seem to be the first
results of this type for this class of nonlinear ensemble type Kalman-Bucy
filters.


title: On detecting Higgs coupling in transitions of light atoms

abstract:
  In light of the known Higgs mass and the current constraints on the
quark-lepton Higgs coupling, we derive conditions for extracting upper limits
on the lepton-nucleon Higgs coupling from light atoms and ions, assuming the
availability of locally precise two- and three-body methods might be
beneficial. A recent work has proposed to extract these limits in heavy atoms
where the Higgs term is enhanced by $\approx 10^3 AZ$, due to both the large
coupling modifier and large $A$, $Z$, and assuming sufficiently precise
relativistic electron wave functions. We first revisit the old idea of using
the Lamb shift in light muonic ions where the coupling is enhanced by about
$201^3 AZ^3$ primarily due to the concentration of the muon wave function at
the origin, the muon coupling modifier already being close to 1. For the muonic
helium an experimental precision below 0.1 ppm is required to reach the
constraints on Higgs couplings. However, theoretical uncertainty is large due
to nuclear potential dependence of the finite size terms enhanced by the small
muon orbit, and their elimination by using several states is precluded due to
the Lamb shift being the only precisely measurable state. In normal
(electronic) light systems transitions between low-lying states lie near the
optical region allowing precise experiments, and extraction may be possible by
eliminating the finite-size, polarization and Zemach moment terms from a set of
transitions, e.g. $1S-2S$ and improved $2^3S-2^3P$ and $2^1S-2^3S$ in ${\rm
He}^+$, while isotope shifts could be used if additional transitions are
measured as precisely.


title:
Efficiently tunable photon emission from an optically driven artificial
  molecule

abstract:
  In this work, we investigate the emission properties of double quantum dot
driven by a monochromatic electromagnetic field, while undergoing resonant
tunneling and dissipation by phonons. We found emission spectra for both cases,
with and without phonons, whose comparison allows to determine the dissipative
effects. On the basis of the obtained results we propose efficient control of
the resonance fluorescence of an artificial molecule, suitable for
optoelectronic applications.


title:
Impact of Free Carriers on Modulational Instability in
  Silicon-on-insulator Nanowaveguides

abstract:
  We have numerically studied the effect of free-carrier-induced loss and
dispersion on the modulational instability (MI) gain at low input powers in
silicon-on-insulator (SOI) nanowaveguides with normal and anomalous
second-order dispersion. We have shown that the free carriers affect the gain
spectra even at low input powers. First time we have reported the gain in
normal SOI nanowaveguides even in the absence of higher order dispersion
parameters, which is due to the interaction of free-carrier-induced dispersion
and nonlinearity. The MI gain in an anomalous SOI nanowaveguide vanishes even
at a few milliwatt range of input power due to this interaction. We have shown
that the gain could be achieved in an anomalous nanowaveguides by reducing the
free carrier lifetime.


title:
Electromagnetically induced transparency with Rydberg atoms across the
  Breit-Rabi regime

abstract:
  We present experimental results on the influence of magnetic fields and laser
polarization on electromagnetically induced transparency (EIT) using Rydberg
levels of $^{87}$Rb atoms. The measurements are performed in a room temperature
vapor cell with two counter-propagating laser beams at 480nm and 780nm in a
ladder-type energy level scheme. We measure the EIT spectrum of a range of
$ns_{1/2}$ Rydberg states for $n=19-27$, where the hyperfine structure can
still be resolved. Our measurements span the range of magnetic fields from the
low field linear Zeeman regime to the high field Paschen-Back regimes. The
observed spectra are very sensitive to small changes in magnetic fields and the
polarization of the laser beams. We model our observations using optical Bloch
equations that take into account the full multi-level structure of the atomic
states involved and the decoupling of the electronic $J$ and nuclear $I$
angular momenta in the Breit-Rabi regime. The numerical model yields excellent
agreement with the observations. In addition to EIT related experiments, our
results are relevant for experiments involving coherent excitation to Rydberg
levels in the presence of magnetic fields.


title: K-stability of Fano manifolds with not small alpha invariants

abstract:
  We show that any $n$-dimensional Fano manifold $X$ with $\alpha(X)=n/(n+1)$
and $n\geq 2$ is K-stable, where $\alpha(X)$ is the alpha invariant of $X$
introduced by Tian. In particular, any such $X$ admits K\"ahler-Einstein
metrics and the holomorphic automorphism group of $X$ is finite.