title:
CRIRES-POP: a library of high resolution spectra from 1 to 5 microns II.
  Data reduction and the spectrum of the K giant 10 Leo

abstract:
  Context. High resolution stellar spectral atlases are valuable resources to
astronomy. They are rare in the $1 - 5\,\mu$m region for historical reasons,
but once available, high resolution atlases in this part of the spectrum will
aid the study of a wide range of astrophysical phenomena. Aims. The aim of the
CRIRES-POP project is to produce a high resolution near-infrared spectral
library of stars across the H-R diagram. The aim of this paper is to present
the fully reduced spectrum of the K giant 10 Leo that will form the basis of
the first atlas within the CRIRES-POP library, to provide a full description of
the data reduction processes involved, and to provide an update on the
CRIRES-POP project. Methods. All CRIRES-POP targets were observed with almost
200 different observational settings of CRIRES on the ESO Very Large Telescope,
resulting in a basically complete coverage of its spectral range as accessible
from the ground. We reduced the spectra of 10 Leo with the CRIRES pipeline,
corrected the wavelength solution and removed telluric absorption with
Molecfit, then resampled the spectra to a common wavelength scale, shifted them
to rest wavelengths, flux normalised, and median combined them into one final
data product. Results. We present the fully reduced, high resolution,
near-infrared spectrum of 10 Leo. This is also the first complete spectrum from
the CRIRES instrument. The spectrum is available online. Conclusions. The first
CRIRES-POP spectrum has exceeded our quality expectations and will form the
centre of a state-of-the-art stellar atlas. This first CRIRES-POP atlas will
soon be available, and further atlases will follow. All CRIRES-POP data
products will be freely and publicly available online.


title:
Transport in a two-dimensional disordered electron liquid with isospin
  degrees of freedom

abstract:
  Recent theoretical results on transport in a two-dimensional disordered
electron liquid with spin and isospin degrees of freedom are reviewed. A number
of experimental features in temperature dependence of resistivity at low
temperatures in Si-MOSFET, n-AlAs quantum well and double quantum well
heterostructures is explained. Novel behavior of low-temperature resistivity at
low temperature in electron systems with isospin degrees of freedom are
predicted.


title:
Flow and dispersion in anisotropic porous media: a Lattice-Boltzmann
  study

abstract:
  Given their capability of spreading active chemical species and collecting
electricity, porous media made of carbon fibers are extensively used as
diffusion layers in energy storage systems, such as redox flow batteries. In
spite of this, the dispersion dynamics of species inside porous media is still
not well understood and often lends itself to different interpretations.
Actually, the microscopic design of efficient porous media which can
potentially and effectively improve the performances of flow batteries, is a
still open challenge. The present study aims to investigate the effect of
fibrous media micro-structure on dispersion, in particular the effect of fiber
orientation on drag and dispersion dynamics. Several Lattice-Boltzmann
simulations of {flows through} differently-oriented fibrous media coupled with
Lagrangian simulations of particle tracers have been performed. Results show
that orienting fibers preferentially along the streamwise direction minimizes
the drag and maximizes the dispersion, which is the most desirable condition
for diffusion layers in flow batteries applications.


title:
Lexicon-Free Fingerspelling Recognition from Video: Data, Models, and
  Signer Adaptation

abstract:
  We study the problem of recognizing video sequences of fingerspelled letters
in American Sign Language (ASL). Fingerspelling comprises a significant but
relatively understudied part of ASL. Recognizing fingerspelling is challenging
for a number of reasons: It involves quick, small motions that are often highly
coarticulated; it exhibits significant variation between signers; and there has
been a dearth of continuous fingerspelling data collected. In this work we
collect and annotate a new data set of continuous fingerspelling videos,
compare several types of recognizers, and explore the problem of signer
variation. Our best-performing models are segmental (semi-Markov) conditional
random fields using deep neural network-based features. In the signer-dependent
setting, our recognizers achieve up to about 92% letter accuracy. The
multi-signer setting is much more challenging, but with neural network
adaptation we achieve up to 83% letter accuracies in this setting.


title:
Finite correlation length implies efficient preparation of quantum
  thermal states

abstract:
  Preparing quantum thermal states on a quantum computer is in general a
difficult task. We provide a procedure to prepare a thermal state on a quantum
computer with a logarithmic depth circuit of local quantum channels assuming
that the thermal state correlations satisfy the following two properties: (i)
the correlations between two regions are exponentially decaying in the distance
between the regions, and (ii) the thermal state is an approximate Markov state
for shielded regions. We require both properties to hold for the thermal state
of the Hamiltonian on any induced subgraph of the original lattice. Assumption
(ii) is satisfied for all commuting Gibbs states, while assumption (i) is
satisfied for every model above a critical temperature. Both assumptions are
satisfied in one spatial dimension. Moreover, both assumptions are expected to
hold above the thermal phase transition for models without any topological
order at finite temperature. As a building block, we show that exponential
decay of correlation (for thermal states of Hamiltonians on all induced
subgraph) is sufficient to efficiently estimate the expectation value of a
local observable. Our proof uses quantum belief propagation, a recent
strengthening of strong sub-additivity, and naturally breaks down for states
with topological order.

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


title:
Linear Support Tensor Machine: Pedestrian Detection in Thermal Infrared
  Images

abstract:
  Pedestrian detection in thermal infrared images poses unique challenges
because of the low resolution and noisy nature of the image. Here we propose a
mid-level attribute in the form of multidimensional template, or tensor, using
Local Steering Kernel (LSK) as low-level descriptors for detecting pedestrians
in far infrared images. LSK is specifically designed to deal with intrinsic
image noise and pixel level uncertainty by capturing local image geometry
succinctly instead of collecting local orientation statistics (e.g., histograms
in HOG). Our second contribution is the introduction of a new image similarity
kernel in the popular maximum margin framework of support vector machines that
results in a relatively short and simple training phase for building a rigid
pedestrian detector. Our third contribution is to replace the sluggish but de
facto sliding window based detection methodology with multichannel discrete
Fourier transform, facilitating very fast and efficient pedestrian
localization. The experimental studies on publicly available thermal infrared
images justify our proposals and model assumptions. In addition, the proposed
work also involves the release of our in-house annotations of pedestrians in
more than 17000 frames of OSU Color Thermal database for the purpose of sharing
with the research community.


title: The CAP representations indexed by Hilbert cusp forms

abstract:
  We combine the Duke-Imamoglu-Ikeda lifting with the theta lifting to produce
new CAP representations of metaplectic, symplectic and orthogonal groups. These
constructions partially generalize the theories of Waldspurger on the Shimura
correspondence and of Piatetski-Shapiro on the Saito-Kurokawa lifting to higher
dimensions. Applications include a relation between Fourier coefficients of
Hilbert cusp forms of weight k+1/2 and a weighted sum of the representation
numbers of a quadratic form of rank 2k by a quadratic form of rank 4k.


title: Parallel forms, co-K\"ahler Manifolds and their Models

abstract:
  We show how certain topological properties of co-K\"ahler manifolds derive
from those of the K\"ahler manifolds which construct them. In particular, we
show that the existence of parallel forms on a co-K\"ahler manifold reduces the
computation of cohomology from the de Rham complex to certain amenable
sub-cdga's defined by geometrically natural operators derived from the
co-K\"ahler structure. This provides a simpler proof of the formality of the
foliation minimal model in this context.


title: Superfast maximum likelihood reconstruction for quantum tomography

abstract:
  Conventional methods for computing maximum-likelihood estimators (MLE) often
converge slowly in practical situations, leading to a search for simplifying
methods that rely on additional assumptions for their validity. In this work,
we provide a fast and reliable algorithm for maximum likelihood reconstruction
that avoids this slow convergence. Our method utilizes the state-of-the-art
convex optimization scheme---an accelerated projected-gradient method---that
allows one to accommodate the quantum nature of the problem in a different way
than in the standard methods. We demonstrate the power of our approach by
comparing its performance with other algorithms for n-qubit state tomography.
In particular, an 8-qubit situation that purportedly took weeks of computation
time in 2005 can now be completed in under a minute for a single set of data,
with far higher accuracy than previously possible. This refutes the common
claim that MLE reconstruction is slow, and reduces the need for alternative
methods that often come with difficult-to-verify assumptions. In fact, recent
methods assuming Gaussian statistics or relying on compressed sensing ideas are
demonstrably inapplicable for the situation under consideration here. Our
algorithm can be applied to general optimization problems over the quantum
state space; the philosophy of projected gradients can further be utilized for
optimization contexts with general constraints.


title: Reparametrizing the Polyakov$-$Nambu$-$Jona-Lasinio model

abstract:
  The Polyakov$-$Nambu$-$Jona-Lasinio model has been quite successful in
describing various qualitative features of observables for strongly interacting
matter, that are measurable in heavy-ion collision experiments. The question
still remains on the quantitative uncertainties in the model results. Such an
estimation is possible only by contrasting these results with those obtained
from first principles using the lattice QCD framework. Recently a variety of
lattice QCD data were reported in the realistic continuum limit. Here we make a
first attempt at reparametrizing the model so as to reproduce these lattice
data. We find excellent quantitative agreement for the equation of state.
Certain discrepancies in the charge and strangeness susceptibilities as well as
baryon-charge correlation still remain. We discuss their causes and outline
possible directions to remove them.


title:
Transverse Magneto-Optical Kerr Effect in Active Magneto-Plasmonic
  Structures

abstract:
  We propose a novel method to enhance the transverse magneto-optical Kerr
effect (TMOKE) in the magneto-plasmonic (MP) nanostructures by means of the
active dielectric layer. We report the theoretical analysis of the
magnetoplasmonic structure with a ferromagnetic dielectric doped with
rear-earth ions (Nd3+) as the example of a gain layer. The enhancement takes
place near the surface plasmon polariton (SPP) resonances of the
nanostructures. The stimulated emission of the dopants in the field of SPP wave
partially compensates its losses. It is shown that due to a decrease of SPP
damping a Q-factor of the MP resonance increases and the TMOKE is increased in
comparison with the passive nanostructure.


title: Inflow process of pedestrians to a confined space

abstract:
  To better design safe and comfortable urban spaces, understanding the nature
of human crowd movement is important. However, precise interactions among
pedestrians are difficult to measure in the presence of their complex
decision-making processes and many related factors. While extensive studies on
pedestrian flow through bottlenecks and corridors have been conducted, the
dominant mode of interaction in these scenarios may not be relevant in
different scenarios. Here, we attempt to decipher the factors that affect human
reactions to other individuals from a different perspective. We conducted
experiments employing the inflow process in which pedestrians successively
enter a confined area (like an elevator) and look for a temporary position. In
this process, pedestrians have a wider range of options regarding their motion
than in the classical scenarios; therefore, other factors might become
relevant. The preference of location is visualized by pedestrian density
profiles obtained from recorded pedestrian trajectories. Non-trivial patterns
of space acquisition, e.g., an apparent preference for positions near corners,
were observed. This indicates the relevance of psychological and anticipative
factors beyond the private sphere, which have not been deeply discussed so far
in the literature on pedestrian dynamics. From the results, four major factors,
which we call flow avoidance, distance cost, angle cost, and boundary
preference, were suggested. We confirmed that a description of decision-making
based on these factors can give a rise to realistic preference patterns, using
a simple mathematical model. Our findings provide new perspectives and a
baseline for considering the optimization of design and safety in crowded
public areas and public transport carriers.


title: Optimal sensor placement using machine learning

abstract:
  A new method for optimal sensor placement based on variable importance of
machine learned models is proposed. With its simplicity, adaptivity, and low
computational cost, the method offers many advantages over existing approaches.
The new method is implemented on the flow over an airfoil equipped with a
Coanda actuator. The analysis is based on flow field data obtained from 2D
unsteady Reynolds averaged Navier-Stokes (URANS) simulations with different
actuation conditions. The optimal sensor locations is compared against the
current de-facto standard of maximum POD modal amplitude location, and against
a brute force approach that scans all possible sensor combinations. The results
show that both the flow conditions and the type of sensor have an effect on the
optimal sensor placement, whereas the choice of the response function appears
to have limited influence.


title: Expansion measurement of Supernova Remnant RX J1713.7-3946

abstract:
  Supernova remnant (SNR) RX J1713.7-3946 is well known for its bright TeV
gamma-ray emission with shell-like morphology. To constrain the hydrodynamical
evolution, we have performed six times observations of the northwestern (NW)
shell with the Chandra X-ray Observatory from 2005 to 2011, and measured the
proper motion by using these data and the first epoch observation taken in
2000. The blast-wave shock speed at the NW shell is measured to be $(3900\pm
300) (d/{\rm kpc})\ {\rm km}\ {\rm s}^{-1}$ with an estimated distance of $d =
1$ kpc, and the proper motions of other structures within the NW shell are
significantly less than that. Assuming that the measured blast-wave shock speed
is the representative of the remnant's outer shock wave as a whole, we have
confronted our measurements as well as a recent detection of thermal X-ray
lines, with the analytic solution of the hydrodynamical properties of SNRs. Our
hydrodynamical analysis indicates that the age of the remnant is 1580-2100
years, supporting the association with SN393. A model with SN kinetic energy of
$E = 10^{51}\, \rm erg$, the ejecta mass of $M_{\rm ej} = 3\, M_{\odot}$, and
the ambient density at the current blast wave location of $n_2 = 0.015\, {\rm
cm}^{-3}$, provides reasonable explanation for our measurements and previous
findings at the X-ray and gamma-ray wavelengths. We find that the transition to
the Sedov-Taylor (ST) phase is incomplete for any reasonable set of parameters,
implying that the current maximum energy of accelerated protons in RX
J1713.7-3946 would not correspond to the maximum attainable energy for this
remnant.


title:
Interpretation of Compositional Regression with Application to Time
  Budget Analysis

abstract:
  Regression with compositional response or covariates, or even regression
between parts of a composition, is frequently employed in social sciences.
Among other possible applications, it may help to reveal interesting features
in time allocation analysis. As individual activities represent relative
contributions to the total amount of time, statistical processing of raw data
(frequently represented directly as proportions or percentages) using standard
methods may lead to biased results. Specific geometrical features of time
budget variables are captured by the logratio methodology of compositional
data, whose aim is to build (preferably orthonormal) coordinates to be applied
with popular statistical methods. The aim of this paper is to present recent
tools of regression analysis within the logratio methodology and apply them to
reveal potential relationships among psychometric indicators in a real-world
data set. In particular, orthogonal logratio coordinates have been introduced
to enhance the interpretability of coefficients in regression models.


title: Pythagorean-Hodograph B-Spline Curves

abstract:
  We introduce the new class of planar Pythagorean-Hodograph (PH) B-Spline
curves. They can be seen as a generalization of the well-known class of planar
Pythagorean-Hodograph (PH) B\'ezier curves, presented by R. Farouki and T.
Sakkalis in 1990, including the latter ones as special cases.
Pythagorean-Hodograph B-Spline curves are non-uniform parametric B-Spline
curves whose arc-length is a B-Spline function as well. An important
consequence of this special property is that the offsets of
Pythagorean-Hodograph B-Spline curves are non-uniform rational B-Spline (NURBS)
curves. Thus, although Pythagorean-Hodograph B-Spline curves have fewer degrees
of freedom than general B-Spline curves of the same degree, they offer unique
advantages for computer-aided design and manufacturing, robotics, motion
control, path planning, computer graphics, animation, and related fields. After
providing a general definition for this new class of planar parametric curves,
we present useful formulae for their construction, discuss their remarkable
attractive properties and give some examples of their practical use.


title:
Chiral optical fields: A unified formulation of helicity scattered from
  particles and dichroism enhancement

abstract:
  We establish a general unified formulation which, using the optical theorem
of electromagnetic helicity, shows that dichorism is a phenomenon arising in
any scattering -or diffraction- process, elastic or not, of chiral
electromagnetic fields by objects either chiral or achiral. It is shown how
this approach paves the way to overcoming well-known limitations of standard
circular dichroism, like its weak signal or the difficulties of using it with
magnetodielectric particles.
  Based on the angular spectrum representation of optical fields with only
right circular or left circular plane waves, we introduce beams with transverse
elliptic polarization and posessing a longitudinal component. Then our
formulation for general optical fields shows how to enhance the extinction rate
of incident helicity, (and therefore the dichroism signal), versus that of
energy of the light scattered or emitted by a particle, or viceversa.


title: Driven tracers in narrow channels

abstract:
  Steady state properties of a driven tracer moving in a narrow two dimensional
(2D) channel of quiescent medium are studied. The tracer drives the system out
of equilibrium, perturbs the density and pressure fields, and gives the bath
particles a nonzero average velocity, creating a current in the channel. Three
models in which the confining effect of the channel is probed are analyzed and
compared in this study: the first is the simple symmetric exclusion process
(SSEP), for which the stationary density profile and the pressure on the walls
in the frame of the tracer are computed. We show that the tracer acts like a
dipolar source in an average velocity field. The spatial structure of this 2D
strip is then simplified to a one dimensional SSEP, in which exchanges of
position between the tracer and the bath particles are allowed. Using a
combination of mean field theory and exact solution in the limit where no
exchange is allowed, gives good predictions of the velocity of the tracer and
the density field. Finally, we show that results obtained for the 1D SSEP with
exchanges also apply to a gas of overdamped hard disks in a narrow channel. The
correspondence between the parameters of the SSEP and of the gas of hard disks
is systematic and follows from simple intuitive arguments. Our analytical
results are checked numerically.


title: Magnon Kerr effect in a strongly coupled cavity-magnon system

abstract:
  We experimentally demonstrate magnon Kerr effect in a cavity-magnon system,
where magnons in a small yttrium iron garnet (YIG) sphere are strongly but
dispersively coupled to the photons in a three-dimensional cavity. When the YIG
sphere is pumped to generate considerable magnons, the Kerr effect yields a
perceptible shift of the cavity's central frequency and more appreciable shifts
of the magnon modes. We derive an analytical relation between the magnon
frequency shift and the drive power for the uniformly magnetized YIG sphere and
find that it agrees very well with the experimental results of the Kittel mode.
Our study paves the way to explore nonlinear effects in the cavity-magnon
system.


title:
In vivo compaction dynamics of bacterial DNA: A fingerprint of DNA/RNA
  demixing ?

abstract:
  The volume occupied by unconstrained bacterial DNA in physiological solutions
exceeds 1000 times the volume of the cell. Still, it is confined to a well
defined region of the cell called the nucleoid, which occupies only a fraction
of the cell volume. There is still no general agreement on the mechanism
leading to the compaction of the DNA and the formation of the nucleoid.
However, advances in in vivo sub-wavelength resolution microscopy techniques
have recently allowed the observation of the nucleoid at an unprecedented level
of detail. In particular, these observations show that the compaction of the
nucleoid is not static but is instead a highly dynamic feature, which depends
on several factors, like the richness of the nutrient, the cell cycle stage,
temperature, the action of an osmotic shock or antibiotics, etc. After a short
description of the electrolyte content of the cytosol and a brief overview of
the different mechanisms that may lead to the formation of the nucleoid, this
paper reviews some of the most fascinating recent results of in vivo
sub-wavelength resolution microscopy. It is furthermore argued that these
observations provide converging indications in favor of a model that describes
the cytosol as an aqueous electrolyte solution containing several
macromolecular species, where demixing and segregative phase separation occur
between DNA and RNA (essentially rRNA and mRNA involved in translation
complexes, but also the large amounts of rRNA synthesized at the rrn operons of
cells growing in rich media). It is also pointed out that crowding may play a
crucial role through its synergy with electrostatic forces. By constraining
macromolecules to remain at short distances from one another and feel
electrostatic interactions in spite of the strong screening exerted by
electrolyte species, crowding favors stronger DNA/RNA demixing and nucleoid
compaction.


title: An extension of Borel-Laplace methods and monomial summability

abstract:
  In this paper we will show that monomial summability can be characterized
using Borel-Laplace like integral transformations depending of a parameter
$0<s<1$. We will apply this result to prove 1-summability in a monomial of
formal solutions of a family of partial differential equations.


title:
Role of incoherent scattering on energy filtering in nanostructured
  thermoelectric generators

abstract:
  The physics of energy filtering in electronic transport through nanoscale
barriers is a fundamental aspect in the context of electronic engineering of
nanostructured thermoelectrics. In the context of thermoelectric generators, it
aims to engineer the Seebeck coefficient to favorably increase the power factor
and ultimately the power generated. In this work, we employ the incoherent
non-equilibrium Green's function formalism to investigate in detail the physics
of energy filtering and how it leads to a direct enhancement in power
generation across nanostructured thermoelectrics featuring a single planar
energy barrier. In particular, we reinforce that the enhancement in the
generated power via energy filtering at a particular operating efficiency is a
characteristic of incoherent scattering and is absent in ballistic devices. In
such cases, by assuming an energy dependent relaxation time, $\tau(E)=kE^r$, we
show that there exists a minimum value $r_{min}$ for which the thermoelectric
power generation is enhanced and thereby leading to a degradation in power
generation for $r<r_{min}$. For bulk generators, we delve into the details of
intermode scattering and show that such scattering processes between electrons
in higher energy modes and lower energy modes have a finite contribution to the
enhancement in the generated power. We also discuss realistic aspects such as
finite width of energy barriers and imperfect energy filtering due to partial
reflections. In particular, we show that such imperfect filtering and partial
transmission of electrons near the top of the barrier affects the enhancement
in the generated power drastically in the high efficiency regime of operation.
Analysis of the results obtained in this work should provide general design
guidelines for nanostructured enhancement in power generation via energy
filtering.


title: Interaction Graphs: Nondeterministic Automata

abstract:
  This paper exhibits a series of semantic characterisations of sublinear
nondeterministic complexity classes. These results fall into the general domain
of logic-based approaches to complexity theory and so-called implicit
computational complexity (ICC), i.e. descriptions of complexity classes without
reference to specific machine models. In particular, it relates strongly to ICC
results based on linear logic since the semantic framework considered stems
from work on the latter. Moreover, the obtained characterisations are of a
geometric nature: each class is characterised by a specific action of a group
by measure-preserving maps.


title:
Resolving the base of the relativistic jet in M87 at 6$R_{\rm sch}$
  resolution with global mm-VLBI

abstract:
  M87 is one of the nearest radio galaxies with a central SMBH and a prominent
relativistic jet. Due to its close distance to the observer and the large SMBH
mass, the source is one of the best laboratories to obtain strong observational
constraints on the theoretical models for the formation and evolution of the
AGN jets. In this article, we present preliminary results from our ongoing
observational study about the innermost jet of M87 at an ultra-high resolution
of $\sim$50${\mu}$as achieved by the Global Millimeter-VLBI Array (GMVA). The
data obtained between 2004 and 2015 clearly show limb-brightened jets at
extreme resolution and sensitivity. Our preliminary analysis reveals that the
innermost jet expands in an edge-brightened cone structure (parabolic shape)
but with the jet expansion profile slightly different from the outer regions of
the jet. Brightness temperatures of the VLBI core obtained from cm- to
mm-wavelengths show a systematic evolution, which can be interpreted as the
evolution as a function of distance from the BH. We also adopt an alternative
imaging algorithm, BSMEM, to test reliable imaging at higher angular resolution
than provided by the standard CLEAN method (i.e. super-resolution). A
demonstration with a VLBA 7mm example data set shows consistent results with a
near-in-time 3mm VLBI image. Application of the method to the 2009 GMVA data
yields an image with remarkable fine-scale structures that have been never
imaged before. We present a brief interpretation of the complexity in the
structure.


title: Risk-Consistent Conditional Systemic Risk Measures

abstract:
  We axiomatically introduce risk-consistent conditional systemic risk measures
defined on multidimensional risks. This class consists of those conditional
systemic risk measures which can be decomposed into a state-wise conditional
aggregation and a univariate conditional risk measure. Our studies extend known
results for unconditional risk measures on finite state spaces. We argue in
favor of a conditional framework on general probability spaces for assessing
systemic risk. Mathematically, the problem reduces to selecting a realization
of a random field with suitable properties. Moreover, our approach covers many
prominent examples of systemic risk measures from the literature and used in
practice.


title: Free Energy Landscape of GAGA and UUCG RNA Tetraloops

abstract:
  We report the folding thermodynamics of ccUUCGgg and ccGAGAgg RNA tetraloops
using atomistic molecular dynamics simulations. We obtain a previously
unreported estimation of the folding free energy using parallel tempering in
combination with well-tempered metadynamics. A key ingredient is the use of a
recently developed metric distance, eRMSD, as a biased collective variable. We
find that the native fold of both tetraloops is not the global free energy
minimum using the Amber\c{hi}OL3 force field. The estimated folding free
energies are 30.2kJ/mol for UUCG and 7.5 kJ/mol for GAGA, in striking
disagreement with experimental data. We evaluate the viability of all possible
one-dimensional backbone force field corrections. We find that disfavoring the
gauche+ region of {\alpha} and {\zeta} angles consistently improves the
existing force field. The level of accuracy achieved with these corrections,
however, cannot be considered sufficient by judging on the basis of available
thermodynamic data and solution experiments.

categories: q-bio.BM physics.bio-ph physics.chem-ph physics.comp-ph


title:
Using an innovative assessment approach on a real-world group based
  software project

abstract:
  Currently, there is a lack of practical, real-world projects on Computer
Science (CS) courses at Maynooth University. Generally CS undergraduate modules
are composed of 24 hours of lectures and 24 hours of labs where students learn
theoretical concepts in the lectures and apply their understanding to practical
lab-based exercises. The problem with this approach is that students do not
gain any awareness of, or learn how to solve tasks that they are likely to
encounter in a real-world industrial setting; nor do they gain experience of
working as part of a team even though most software development positions
involve team-based work.
  This paper reports on a web-based development module that incorporated a
real-world group based project was re-designed and delivered. The module went
well; however, assessing the work fairly was found to be difficult, especially
where team members contributed at considerably varying levels was a challenge.
Of particular concern was that some hard-working students were penalised by
other students poor work and lazy students were rewarded because of more
hard-working students work.
  This action research project will attempt to re-address how to assess this
group-based work with a cohort of students. The goal of the research is to
implement an innovative assessment structure, using peer-, self-, and
co-assessment, for a group based real-world project, that is deemed fair and
reasonable and provided a good learning environment.


title: Contour curves and isophotes on rational ruled surfaces

abstract:
  The ruled surfaces, i.e., surfaces generated by one parametric set of lines,
are widely used in the~field of applied geometry. An~isophote on a surface is a
curve consisting of surface points whose normals form a constant angle with
some fixed vector. Choosing an angle equal to $\pi/2$ we obtain a special
instance of a~isophote -- the so called contour curve. While contours on
rational ruled surfaces are rational curves, this is no longer true for the
isophotes. Hence we will provide a formula for their genus. Moreover we will
show that the only surfaces with a~rational generic contour are just rational
ruled surfaces and a one particular class of cubic surfaces. In addition we
will deal with the reconstruction of ruled surfaces from their contours and
silhouettes.


title:
Relativistic theory of spin relaxation mechanisms in the
  Landau-Lifshitz-Gilbert equation of spin dynamics

abstract:
  Starting from the Dirac-Kohn-Sham equation we derive the relativistic
equation of motion of spin angular momentum in a magnetic solid under an
external electromagnetic field. This equation of motion can be written in the
form of the well-known Landau-Lifshitz-Gilbert equation for a harmonic external
magnetic field, and leads to a more general magnetization dynamics equation for
a general time-dependent magnetic field. In both cases with an electronic
spin-relaxation term which stems from the spin-orbit interaction. We thus
rigorously derive, from fundamental principles, a general expression for the
anisotropic damping tensor which is shown to contain an isotropic Gilbert
contribution as well as an anisotropic Ising-like and a chiral,
Dzyaloshinskii-Moriya-like contribution. The expression for the spin relaxation
tensor comprises furthermore both electronic interband and intraband
transitions. We also show that when the externally applied electromagnetic
field possesses spin angular momentum, this will lead to an optical spin torque
exerted on the spin moment.


title:
On the Solution of Large-Scale Robust Transmission Network Expansion
  Planning under Uncertain Demand and Generation Capacity

abstract:
  Two-stage robust optimization has emerged as a relevant approach to deal with
uncertain demand and generation capacity in the transmission network expansion
planning problem. Unfortunately, available solution methodologies for the
resulting trilevel robust counterpart are unsuitable for large-scale problems.
In order to overcome this shortcoming, this paper presents an alternative
column-and-constraint generation algorithm wherein the max-min problem
associated with the second stage is solved by a novel coordinate descent
method. As a major salient feature, the proposed approach does not rely on the
transformation of the second-stage problem to a single-level equivalent. As a
consequence, bilinear terms involving dual variables or Lagrange multipliers do
not arise, thereby precluding the use of computationally expensive big-M-based
linearization schemes. Thus, not only is the computational effort reduced, but
also the typically overlooked non-trivial tuning of bounding parameters for
dual variables or Lagrange multipliers is avoided. The practical applicability
of the proposed methodology is confirmed by numerical testing on several
benchmarks including a case based on the Polish 2383-bus system, which is well
beyond the capability of the robust methods available in the literature.


title: Strongly Consistent Multivariate Conditional Risk Measures

abstract:
  We consider families of strongly consistent multivariate conditional risk
measures. We show that under strong consistency these families admit a
decomposition into a conditional aggregation function and a univariate
conditional risk measure as introduced Hoffmann et al. (2016). Further, in
analogy to the univariate case in F\"ollmer (2014), we prove that under
law-invariance strong consistency implies that multivariate conditional risk
measures are necessarily multivariate conditional certainty equivalents.


title: Dirac fields in flat FLRW cosmology: Uniqueness of the Fock quantization

abstract:
  We address the issue of the infinite ambiguity that affects the construction
of a Fock quantization of a Dirac field propagating in a cosmological spacetime
with flat compact sections. In particular, we discuss a physical criterion that
restricts to a unique possibility (up to unitary equivalence) the infinite set
of available vacua. We prove that this desired uniqueness is guaranteed, for
any possible choice of spin structure on the spatial sections, if we impose two
conditions. The first one is that the symmetries of the classical system must
be implemented quantum mechanically, so that the vacuum is invariant under the
symmetry transformations. The second and more important condition is that the
constructed theory must have a quantum dynamics that is implementable as a
(non-trivial) unitary operator in Fock space. Actually, this unitarity of the
quantum dynamics leads us to identify as explicitly time dependent some very
specific contributions of the Dirac field. In doing that, we essentially
characterize the part of the dynamics governed by the Dirac equation that is
unitarily implementable. The uniqueness of the Fock vacuum is attained then
once a physically motivated convention for the concepts of particles and
antiparticles is fixed.


title:
Transparent EuTiO3 films: a novel two-dimensional magneto-optical device
  for light modulation

abstract:
  The magneto-optical activity of high quality transparent thin films of
insulating EuTiO3 (ETO) deposited on a thin SrTiO3 (STO) substrate with both
being non-magnetic materials are demonstrated to be a versatile tool for light
modulation. The operating temperature is close to room temperature and admits
multiple device engineering. By using small magnetic fields birefringence of
the samples can be switched off and on. Similarly, rotation of the sample in
the field can modify its birefringence {\Delta}n. In addition, {\Delta}n can be
increased by a factor of 4 in very modest fields with simultaneously enhancing
the operating temperature by almost 100K.


title:
Learning through experimenting: an original way of teaching geometrical
  optics

abstract:
  Over the past 10 years, we have developed at University Paris Sud a first
year course on geometrical optics centered on experimentation. In contrast with
the traditional top-down learning structure usually applied at university, in
which practical sessions are often a mere verification of the laws taught
during preceding lectures, this course promotes "active learning" and focuses
on experiments made by the students. Interaction among students and self
questioning are strongly encouraged and practicing comes first, before any
theoretical knowledge. Through a series of concrete examples, the present paper
describes the philosophy underlying the teaching in this course. We demonstrate
that not only geometrical optics can be taught through experiments, but also
that it can serve as a useful introduction to experimental physics. Feedback
over the last ten years shows that our approach succeeds in helping students to
learn better and acquire motivation and autonomy. This approach can easily be
applied to other fields of physics.


title: Performance Comparison of Short-Length Error-Correcting Codes

abstract:
  We compare the performance of short-length linear binary codes on the binary
erasure channel and the binary-input Gaussian channel. We use a universal
decoder that can decode any linear binary block code: Gaussian-elimination
based Maximum-Likelihood decoder on the erasure channel and probabilistic
Ordered Statistics Decoder on the Gaussian channel. As such we compare codes
and not decoders. The word error rate versus the channel parameter is found for
LDPC, Reed-Muller, Polar, and BCH codes at length 256 bits. BCH codes
outperform other codes in absence of cyclic redundancy check. Under joint
decoding, the concatenation of a cyclic redundancy check makes all codes
perform very close to optimal lower bounds.


title:
Spectrahedral Containment and Operator Systems with Finite-Dimensional
  Realization

abstract:
  Containment problems for polytopes and spectrahedra appear in various
applications, such as linear and semidefinite programming, combinatorics,
convexity and stability analysis of differential equations. This paper explores
the theoretical background of a method proposed by Ben-Tal and Nemirovksi.
Their method provides a strengthening of the containment problem, that is
algorithmically well tractable. To analyze this method, we study abstract
operator systems, and investigate when they have a finite-dimensional concrete
realization. Our results give some profound insight into their approach. They
imply that when testing the inclusion of a fixed polyhedral cone in an
arbitrary spectrahedron, the strengthening is tight if and only if the
polyhedral cone is a simplex. This is true independent of the representation of
the polytope. We also deduce error bounds in the other cases, simplifying and
extending recent results by various authors.


title: Pickands' constant at first order in an expansion around Brownian motion

abstract:
  In the theory of extreme values of Gaussian processes, many results are
expressed in terms of the Pickands constant $\mathcal{H}_{\alpha}$. This
constant depends on the local self-similarity exponent $\alpha$ of the process,
i.e. locally it is a fractional Brownian motion (fBm) of Hurst index
$H=\alpha/2$. Despite its importance, only two values of the Pickands constant
are known: ${\cal H}_1 =1$ and ${\cal H}_2=1/\sqrt{\pi}$. Here, we extend the
recent perturbative approach to fBm to include drift terms. This allows us to
investigate the Pickands constant $\mathcal{H}_{\alpha}$ around standard
Brownian motion ($\alpha =1$) and to derive the new exact result
$\mathcal{H}_{\alpha}=1 - (\alpha-1) \gamma_{\rm E} + \mathcal{O}\!\left(
\alpha-1\right)^{2}$.


title:
From Perception to Decision: A Data-driven Approach to End-to-end Motion
  Planning for Autonomous Ground Robots

abstract:
  Learning from demonstration for motion planning is an ongoing research topic.
In this paper we present a model that is able to learn the complex mapping from
raw 2D-laser range findings and a target position to the required steering
commands for the robot. To our best knowledge, this work presents the first
approach that learns a target-oriented end-to-end navigation model for a
robotic platform. The supervised model training is based on expert
demonstrations generated in simulation with an existing motion planner. We
demonstrate that the learned navigation model is directly transferable to
previously unseen virtual and, more interestingly, real-world environments. It
can safely navigate the robot through obstacle-cluttered environments to reach
the provided targets. We present an extensive qualitative and quantitative
evaluation of the neural network-based motion planner, and compare it to a
grid-based global approach, both in simulation and in real-world experiments.


title:
A Model for the Adoption Process of Information System Security
  Innovations in Organisations: A Theoretical Perspective

abstract:
  In this paper, we develop a theoretical model for the adoption process of
Information System Security innovations in organisations. The model stemmed
from the Diffusion of Innovation theory (DOI), the Technology Acceptance Model
(TAM), the Theory of Planned Behaviour (TPB) and the
Technology-Organisation-Environment (TOE) framework. The model portrays
Information System Security adoption process progressing in a sequence of
stages. The study considers the adoption process from the initiation stage
until the acquisition of innovation as an organisational level judgement while
the process of innovation assimilation and integration is assessed in terms of
the user behaviour within the organisation. The model also introduces several
factors that influence the Information System Security innovation adoption. By
merging the organisational adoption and user acceptance of innovation in a
single depiction, this research contributes to IS security literature a more
comprehensive model for IS security adoption in organisation, compare to any of
the past representations.


title: Construction Safety Risk Modeling and Simulation

abstract:
  By building on a recently introduced genetic-inspired attribute-based
conceptual framework for safety risk analysis, we propose a novel methodology
to compute construction univariate and bivariate construction safety risk at a
situational level. Our fully data-driven approach provides construction
practitioners and academicians with an easy and automated way of extracting
valuable empirical insights from databases of unstructured textual injury
reports. By applying our methodology on an attribute and outcome dataset
directly obtained from 814 injury reports, we show that the frequency-magnitude
distribution of construction safety risk is very similar to that of natural
phenomena such as precipitation or earthquakes. Motivated by this observation,
and drawing on state-of-the-art techniques in hydroclimatology and insurance,
we introduce univariate and bivariate nonparametric stochastic safety risk
generators, based on Kernel Density Estimators and Copulas. These generators
enable the user to produce large numbers of synthetic safety risk values
faithfully to the original data, allowing safetyrelated decision-making under
uncertainty to be grounded on extensive empirical evidence. Just like the
accurate modeling and simulation of natural phenomena such as wind or
streamflow is indispensable to successful structure dimensioning or water
reservoir management, we posit that improving construction safety calls for the
accurate modeling, simulation, and assessment of safety risk. The underlying
assumption is that like natural phenomena, construction safety may benefit from
being studied in an empirical and quantitative way rather than qualitatively
which is the current industry standard. Finally, a side but interesting finding
is that attributes related to high energy levels and to human error emerge as
strong risk shapers on the dataset we used to illustrate our methodology.


title:
Stereochemical configuration and selective excitation of the chiral
  molecule halothane

abstract:
  X-ray single-photon ionization and fragmentation of the chiral molecule
halothane (CHBrClCF${}_{3}$) from a racemic mixture have been investigated
using the COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) technique.
Two important facets related to the core ionization of this species are
examined: Firstly, the distinction of enantiomers (mirror isomers) and the
determination of absolute configuration on a single-molecule level by four-body
Coulomb explosion; secondly, the interplay of site-selective excitation and
fragmentation patterns. These results are easily transferrable to other
molecular species and show the wealth of features


title:
Torsional oscillations and observed rotational period variations in
  early-type stars

abstract:
  Some chemically peculiar stars in the upper main sequence show rotational
period variations of unknown origin. We propose these variations are a
consequence of the propagation of internal waves in magnetic rotating stars
that lead to the torsional oscillations of the star. We simulate the
magnetohydrodynamic waves and calculate resonant frequencies for two stars that
show rotational variations: CU Vir and HD 37776. We provide updated analyses of
rotational period variations in these stars and compare our results with
numerical models. For CU Vir, the length of the observed rotational-period
cycle, $\mathit\Pi=67.6(5)$ yr, can be well reproduced by the models, which
predict a cycle length of 51 yr. However, for HD 37776, the observed lower
limit of the cycle length, $\mathit\Pi\geq100$ yr, is significantly longer than
the numerical models predict. We conclude that torsional oscillations provide a
reasonable explanation at least for the observed period variations in CU Vir.


title: Special Ulrich bundles on non-special surfaces with $p_g=q=0$

abstract:
  Let $S$ be a surface with $p_g(S)=q(S)=0$ and endowed with a very ample line
bundle $\mathcal O_S(h)$ such that $h^1\big(S,\mathcal O_S(h)\big)=0$. We show
that $S$ supports special (often stable) Ulrich bundles of rank $2$, extending
a recent result by A. Beauville. Moreover, we show that such an $S$ supports
families of dimension $p$ of pairwise non-isomorphic, indecomposable, Ulrich
bundles for arbitrary large $p$ except for very few cases. We also show that
the same is true for linearly normal non-special surface in $\mathbb P^4$ of
degree at least $4$, Enriques surface and anticanonical rational surface.


title: Deep Structured Features for Semantic Segmentation

abstract:
  We propose a highly structured neural network architecture for semantic
segmentation with an extremely small model size, suitable for low-power
embedded and mobile platforms. Specifically, our architecture combines i) a
Haar wavelet-based tree-like convolutional neural network (CNN), ii) a random
layer realizing a radial basis function kernel approximation, and iii) a linear
classifier. While stages i) and ii) are completely pre-specified, only the
linear classifier is learned from data. We apply the proposed architecture to
outdoor scene and aerial image semantic segmentation and show that the accuracy
of our architecture is competitive with conventional pixel classification CNNs.
Furthermore, we demonstrate that the proposed architecture is data efficient in
the sense of matching the accuracy of pixel classification CNNs when trained on
a much smaller data set.


title:
Efficient continuous-wave nonlinear frequency conversion in high-Q
  Gallium Nitride photonic crystal cavities on Silicon

abstract:
  We report on nonlinear frequency conversion from the telecom range via second
harmonic generation (SHG) and third harmonic generation (THG) in suspended
gallium nitride slab photonic crystal (PhC) cavities on silicon, under
continuous-wave resonant excitation. Optimized two-dimensional PhC cavities
with augmented far-field coupling have been characterized with quality factors
as high as 4.4$\times10^{4}$, approaching the computed theoretical values. The
strong enhancement in light confinement has enabled efficient SHG, achieving
normalized conversion efficiency of 2.4$\times10^{-3}$ $W^{-1}$, as well as
simultaneous THG. SHG emission power of up to 0.74 nW has been detected without
saturation. The results herein validate the suitability of gallium nitride for
integrated nonlinear optical processing.


title:
A linear algorithm for the identification of a weakly singular
  relaxation kernel using two boundary measurements

abstract:
  We consider a distributed system of a type which is encountered in the study
of diffusion processes with memory and in viscoelasticity. The key feature of
such system is the persistence in the future of the past actions due the memory
described via a certain relaxation kernel, see below.
  The parameters of the kernel have to be inferred from experimental
measurements. Our main result in this paper is that by using two boundary
measurements the identification of a relaxation kernel which is linear
combination of Abel kernels (as often assumed in applications) can be reduced
to the solution of a (linear) deconvolution problem.


title:
Copositive Tensor Detection and Its Applications in Physics and
  Hypergraphs

abstract:
  Copositivity of tensors plays an important role in vacuum stability of a
general scalar potential, polynomial optimization, tensor complementarity
problem and tensor generalized eigenvalue complementarity problem. In this
paper, we propose a new algorithm for testing copositivity of high order
tensors, and then present applications of the algorithm in physics and
hypergraphs. For this purpose, we first give several new conditions for
copositivity of tensors based on the representative matrix of a simplex. Then a
new algorithm is proposed with the help of a proper convex subcone of the
copositive tensor cone, which is defined via the copositivity of Z-tensors.
Furthermore, by considering a sum-of-squares program problem, we define two new
subsets of the copositive tensor cone and discuss their convexity. As an
application of the proposed algorithm, we prove that the coclique number of a
uniform hypergraph is equivalent with an optimization problem over the
completely positive tensor cone, which implies that the proposed algorithm can
be applied to compute an upper bound of the coclique number of a uniform
hypergraph. Then we study another application of the proposed algorithm on
particle physics in testing copositivity of some potential fields. At last,
various numerical examples are given to show the performance of the algorithm.


title:
The $NLO$ production of the $W^{\pm}$ and $Z^0$ vector bosons via hadron
  collisions in the frameworks of $KMR$ and $MRW$ unintegrated parton
  distribution functions

abstract:
  In a series of papers, we have investigated the compatibility of the
$Kimber$-$Martin$-$Ryskin$ ($KMR$) and $Martin$-$Ryskin$-$Watt$ ($MRW$)
$unintegrated$ parton distribution functions ($UPDF$) as well as the
description of the experimental data on the proton structure functions. The
present work is a sequel to that survey, via calculation of the transverse
momentum distribution of the electro-weak gauge vector bosons in the
$k_t$-factorization scheme, by the means of the $KMR$, the $LO\;MRW$ and the
$NLO\;MRW$ $UPDF$, in the next-to leading order ($NLO$). To this end, we have
calculated and aggregated the invariant amplitudes of the corresponding
$involved$ diagrams in the $NLO$, and counted the individual contributions in
different frameworks. The preparation process for the $UPDF$ utilizes the $PDF$
of $Martin$ et al, $MSTW2008-LO$, $MSTW2008-NLO$, $MMHT2014-LO$ and
$MMHT2014-NLO$ as the inputs. Afterwards, the results have been analyzed
against each other, as well as the existing experimental data. Our calculation
show excellent agreement with the experiment data. It is however interesting to
point-out that, the calculation using the $KMR$ framework illustrates a
stronger agreement with the experimental data, despite the fact that the
$LO\;MRW$ and the $NLO\;MRW$ formalisms employ a better theoretical description
of the $DGLAP$ evolution equation. This is of course due to the use of the
different implementation of the angular ordering constraint in the $KMR$
approach, in which automatically includes the re-summation of $ln({1/x})$,
$BFKL$ logarithms, in the $LO$-$DGLAP$ evolution equation.


title: Casimir Effect in the Kerr Spacetime with Quintessence

abstract:
  We calculate the Casimir energy of a massless scalar field in a cavity formed
by nearby parallel plates orbiting a rotating spherical body surrounded by
quintessence, investigating the influence of the gravitational field on that
energy, at zero temperature. This influence includes the effects due to the
spacetime dragging caused by the source rotation as well as those ones due to
the quintessence. We show that the energy depends on all the involved
parameters, as source mass, angular momentum and quintessence state parameter,
for any radial coordinate and polar angle. We show that at the north pole the
Casimir energy is not influenced by the quintessential matter. At the
equatorial plane, when the quintessence is canceled, the result obtained in the
literature is recovered. Finally, constraints in the quintessence parameters
are obtained from the uncertainty in the current measurements of Casimir
effect.


title: It wasn't me! Plausible Deniability in Web Search

abstract:
  Our ability to control the flow of sensitive personal information to online
systems is key to trust in personal privacy on the internet. We ask how to
detect, assess and defend user privacy in the face of search engine
personalisation? We develop practical and scalable tools allowing a user to
detect, assess and defend against threats to plausible deniability. We show
that threats to plausible deniability of interest are readily detectable for
all topics tested in an extensive testing program. We show this remains the
case when attempting to disrupt search engine learning through noise query
injection and click obfuscation are used. We use our model we design a defence
technique exploiting uninteresting, proxy topics and show that it provides
amore effective defence of plausible deniability in our experiments.


title: Function Computation through a Bidirectional Relay

abstract:
  We consider a function computation problem in a three node wireless network.
Nodes A and B observe two correlated sources $X$ and $Y$ respectively, and want
to compute a function $f(X,Y)$. To achieve this, nodes A and B send messages to
a relay node C at rates $R_A$ and $R_B$ respectively. The relay C then
broadcasts a message to A and B at rate $R_C$. We allow block coding, and study
the achievable region of rate triples under both zero-error and
$\epsilon$-error. As a preparation, we first consider a broadcast network from
the relay to A and B. A and B have side information $X$ and $Y$ respectively.
The relay node C observes both $X$ and $Y$ and broadcasts an encoded message to
A and B. We want to obtain the optimal broadcast rate such that A and B can
recover the function $f(X,Y)$ from the received message and their individual
side information $X$ and $Y$ respectively. For this problem, we show
equivalence between $\epsilon$-error and zero-error computations-- this gives a
rate characterization for zero-error computation. As a corollary, this also
gives a rate characterization for the relay network under zero-error for a
class of functions called {\em component-wise one-to-one functions} when the
support set of $p_{XY}$ is full. For the relay network, the zero-error rate
region for arbitrary functions is characterized in terms of graph coloring of
some suitably defined probabilistic graphs. We then give a single-letter inner
bound to this rate region. Further, we extend the graph theoretic ideas to
address the $\epsilon$-error problem and obtain a single-letter inner bound.


title: On Intersection of Conjugate Subgoups

abstract:
  We give several algorithms addressing computations of intersections of
conjugate subgroups.


title: Hofer-Like Geometry and Flux Theory

abstract:
  This paper meticulously revisit and study the flux geometry of any compact
oriented manifold $(M; W)$. We generalize several well-known factorization
results, exhibit some orbital conditions for the study of flux geometry, give a
proof of the discreteness of the flux group for volume-preserving
diffeomorphisms, show that any smooth path in the kernel of the flux is a
vanishing flux path, and show that the kernel of the flux for volume-preserving
diffeomorphisms is $C^1$closed inside the group of all volume-preserving
diffeomorphisms isotopic to the identity map:This recovers several results from
symplectic geometry. The fix-points theory does not resist to the above
machinery: We prove a general contractibility result with respect to the orbits
of the fix-points for volume-preserving diffeomorphisms isotopic to the
identity map via vanishing-flux paths, generalize and solve the Arnold
conjecture using the Thurston fragmentation property. In the sequel, we use
fix-points to: Characterize the flux geometry of certain $C^0$limits of
sequences of vanishing-flux paths and volumepreserving diffeomorphisms. Beside
this, a $C^0$criterion for the existence of at least one fix-point is given,
and a weak version of the generalized $C^0$flux conjecture is solved. Finally,
we construct a pseudo right-invariant metric on the group of all
volume-preserving diffeomorphisms isotopic to the identity map, prove several
comparison results suitable to the study of the Hofer-like geometry of the
group $Ham(N; w)$, of all Hamiltonian diffeomorphisms of a closed symplectic
manifold $(N; w)$, derive the equivalence between the Hofer and the Hofer-like
metrics on $Ham(N; w)$, and exhibit a computational proof of the non-degeneracy
of the Hofer-like energies: Here, an outcome is that the Calabi group controls
the Hofer-like geometry of the group $Ham(N; w)$ of any closed symplectic
manifold $(N; w)$.


title: On the digital representation of integers with bounded prime factors

abstract:
  Let $b \ge 2$ be an integer. Not much is known on the representation in base
$b$ of prime numbers or of numbers whose prime factors belong to a given,
finite set. Among other results, we establish that any sufficiently large
integer which is not a multiple of $b$ and has only small (in a suitable sense)
prime factors has at least four nonzero digits in its representation in base
$b$.


title: Triple Massey Products with weights in Galois cohomology

abstract:
  Fix an arbitrary prime $p$. Let $F$ be a field containing a primitive $p$-th
root of unity, with absolute Galois group $G_F$, and let $H^n$ denote its mod
$p$ cohomology group $H^n(G_F,\mathbb{Z}/p\mathbb{Z})$. The triple Massey
product of weight $(n,k,m)\in \mathbb{N}^3$ is a partially defined,
multi-valued function $\langle \cdot,\cdot,\cdot \rangle: H^n\times H^k\times
H^m\rightarrow H^{n+k+m-1}.$ %(in the mod-$p$ Galois cohomology) In this work
we prove that for an arbitrary prime $p$, any defined $3MP$ of weight
$(n,1,m)$, where the first and third entries are assumed to be symbols,
contains zero; and that for $p=2$ any defined $3MP$ of the weight $(1,k,1)$,
where the middle entry is a symbol, contains zero. Finally, we use the
description of the kernel of multiplication by a symbol to study general 3MP
where the middle slot is a symbol. The main tools we will be using is Lemma 4.1
concerning the the annihilator of cup product with an $H^1$ element, and
Theorem 5.2, generalizing a Theorem of Tignol on quaternion algebras with
trivial corestriction along a separable quadratic extension.


title: Truncated Calogero-Sutherland Models on a Circle

abstract:
  We investigate a quantum many-body system with particles moving on a circle
and subject to two-body and three-body potentials. In this new class of models,
that extrapolates from the celebrated Calogero-Sutherland model and a system
with interactions among nearest and next-to-nearest neighbors, the interactions
can be tuned as a function of range. We determine the exact ground state energy
and wavefunction and obtain a part of the excitation spectrum.

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


title: Random Matrices and Matrix Completion

abstract:
  The aim of this note (as well as of the course itself) is to give a largely
self-contained proof of two of the main results in the field of low-rank matrix
recovery. This field aims for identification of low-rank matrices from only
limited linear information exploiting in a crucial way their very special
structure. As a crucial tool we develop also the basic statements of the theory
of random matrices.
  The notes are based on a number of sources, which appeared in the last few
years. As we give only the minimal amount of the subject needed for the
application in mind, the reader is invited to study this further reading in
detail.


title: On dust-gas gravitational instabilities in protoplanetary discs

abstract:
  In protoplanetary disks the aerodynamical friction between particles and gas
induces a variety of instabilities that facilitate planet formation. Of these
we examine the so-called `secular gravitational instability' (SGI) in the
two-fluid approximation, deriving analytical expressions for its stability
criteria and growth rates. Concurrently, we present a physical explanation of
the instability that shows how it manifests upon an intermediate range of
lengthscales exhibiting geostrophic balance in the gas component. In contrast
to a single-fluid treatment, the SGI is quenched within a critical disk radius,
as large as 10 AU and 30 AU for cm and mm sized particles respectively,
although establishing robust estimates is hampered by uncertainties in the
parameters (especially the strength of turbulence) and deficiencies in the
razor-thin disk model we employ. It is unlikely, however, that the SGI is
relevant for well-coupled dust. We conclude by applying these results to the
question of planetesimal formation and the provenance of large-scale dust
rings.


title:
New phenomenology from an old theory--new equilibrium states in the BCS
  model

abstract:
  I analyze the low temperature limit of the BCS theory of s-wave single-band
superconductors, when the attraction band may be asymmetric with respect to the
chemical potential. I discuss equilibrium systems, taking consistently into
account the variation of the energy and of the total number of particles with
the populations of the quasiparticle energy levels. I show that the equation
for the energy gap has two solutions, one of which is stable and the other one
is metastable. When the chemical potential is the center of the attraction band
(the standard BCS assumption), the energy gap in the stable solution is
$\Delta_0$, whereas in the metastable one is $\Delta_0/3$. If the chemical
potential is not in the center of the attraction band, then a quasiparticle
imbalance appears. If the absolute value of the difference between the chemical
potential and center of the attraction band is bigger than $2\Delta_0$, then
the superconducting energy gap cannot be formed. If the number of particles is
conserved and the attraction band is asymmetric, then the stable solution is
unphysical and only metastable solutions are realized.


title:
First direct measurement of the $^{11}$C($\alpha$, p)$^{14}$N stellar
  reaction by an extended thick-target method

abstract:
  The $^{11}$C($\alpha$, p) reaction is an important $\alpha$-induced reaction
competing with $\beta$-limited hydrogen-burning processes in high-temperature
explosive stars. We directly measured its reaction cross sections both for the
ground-state transition ($\alpha$, $p_{0}$) and the excited-state transitions
($\alpha$, $p_{1}$) and ($\alpha$, $p_{2}$) at relevant stellar energies 1.3 -
4.5 MeV by an extended thick-target method featuring time of flight for the
first time. We revised the reaction rate by numerical integration including the
($\alpha$, $p_{1}$) and ($\alpha$, $p_{2}$) contributions and also low-lying
resonances of ($\alpha$, $p_{0}$) using both the present and the previous
experimental data which were totally neglected in the previous compilation
works. The present total reaction rate lies between the previous ($\alpha$,
$p_{0}$) rate and the total rate of the Hauser-Feshbach statistical model
calculation, which is consistent with the relevant explosive hydrogen-burning
scenarios such as the $\nu p$-process.


title: Black holes with constant topological Euler density

abstract:
  A class of four dimensional spherically symmetric and static geometries with
constant topological Euler density is studied. These geometries are shown to
solve the coupled Einstein-Maxwell system when non-linear Born-Infeld-like
electrodynamics is employed.


title: On the arithmetic and geometric means of the prime numbers

abstract:
  In this paper we establish explicit upper and lower bounds for the ratio of
the arithmetic and geometric means of the prime numbers, which improve the
current best estimates. Further, we prove several conjectures related to this
ration stated by Hassani. In order to do this, we use explicit estimates for
the prime counting function, Chebyshev's $\vartheta$-function and the sum of
the first $n$ prime numbers.


title: On Erd\H{o}s and S\'ark\"ozy's sequences with Property P

abstract:
  A sequence $A$ of positive integers having the property that no element $a_i
\in A$ divides the sum $a_j+a_k$ of two larger elements is said to have
`Property P'. We construct an infinite set $S\subset \mathbb{N}$ having
Property P with counting function $S(x)\gg\frac{\sqrt{x}}{\sqrt{\log
x}(\log\log x)^2(\log \log \log x)^2}$. This improves on an example given by
Erd\H{o}s and S\'ark\"ozy with a lower bound on the counting function of order
$\frac{\sqrt{x}}{\log x}$.


title:
SAIL: A CUDA-based implementation of the simulated annealing for the
  inverse Laplace transform problem

abstract:
  We developed a CUDA-based parallelization of the annealing method for the
inverse Laplace transform problem. The algorithm is based on annealing
algorithm and minimizes residue of the reconstruction of the spectral function.
We introduce local updates which preserve first two sum rules and allow an
efficient parallel CUDA implementation. Annealing is performed with the Monte
Carlo method on a population of Markov walkers. We propose imprinted branching
method to improve further the convergence of the anneal. The algorithm is
tested on truncated double-peak Lorentzian spectrum with examples of how the
error in the input data affects the reconstruction.


title:
Weak-lensing shear estimates with general adaptive moments, and studies
  of bias by pixellation, PSF distortions, and noise

abstract:
  In weak gravitational lensing, weighted quadrupole moments of the brightness
profile in galaxy images are a common way to estimate gravitational shear. We
employ general adaptive moments (GLAM) to study causes of shear bias on a
fundamental level and for a practical definition of an image ellipticity. The
GLAM ellipticity has useful properties for any chosen weight profile: the
weighted ellipticity is identical to that of isophotes of elliptical images,
and in absence of noise and pixellation it is always an unbiased estimator of
reduced shear. We show that moment-based techniques, adaptive or unweighted,
are similar to a model-based approach in the sense that they can be seen as
imperfect fit of an elliptical profile to the image. Due to residuals in the
fit, moment-based estimates of ellipticities are prone to underfitting bias
when inferred from observed images. The estimation is fundamentally limited
mainly by pixellation which destroys information on the original, pre-seeing
image. We give an optimized estimator for the pre-seeing GLAM ellipticity and
quantify its bias for noise-free images. To deal with pixel noise, we consider
a Bayesian approach where the posterior of the GLAM ellipticity can be
inconsistent with the true ellipticity if we do not properly account for our
ignorance about fit residuals. This underfitting bias is S/N-independent but
changes with the pre-seeing brightness profile and the correlation or
heterogeneity of pixel noise over the post-seeing image. Furthermore, when
inferring a constant ellipticity or, more relevantly, constant shear from a
source sample with a distribution of intrinsic properties (sizes, centroid
positions, intrinsic shapes), an additional, now noise-dependent bias arises
towards low S/N if incorrect priors for the intrinsic properties are used. We
discuss the origin of this prior bias.


title: A Note On Signs Of Fourier Coefficients Of Two Cusp Forms

abstract:
  Kohnen and Sengupta proved that two cusp forms of different integral weights
with real algebraic Fourier coefficients have infinitely many Fourier
coefficients of the same as well as of opposite sign, up to the action of a
Galois automorphism. Recently Gun, Kohnen and Rath strengthen their result by
comparing the simultaneous sign changes of Fourier coefficients of two cusp
forms with arbitrary real Fourier coefficients. The simultaneous sign changes
of Fourier coefficients of two same integral weight cusp forms follow from an
earlier work of Ram Murty. In this note we compare the signs of the Fourier
coefficients of two cusp forms simultaneously for the congruence subgroup
$\Gamma_0(\mathit{N})$ where the coefficients lie in an arithmetic progression.
Next we consider an analogous question for the particular sparse sequences of
Fourier coefficients of normalized Hecke eigen cusp forms for the full modular
group.


title: Demonstration of liquid crystal for barocaloric cooling application

abstract:
  Current vapor-compression technology is based on the gas-liquid transition of
hazardous gas. The alternative cooling technology focuses on the solid caloric
material. A new liquid barocaloric material, i.e. the liquid crystal, is proved
to be potential for cooling application primarily (based on other literatures).
Its phase transition needs a small stress (tens of MPa) and can be operated
near room temperature. It has a large entropy change of ~200 J.K-1.kg-1 (0.2
J.K-1.cm-1). There is no breakage problem due to its liquid form. It will
provide the advantage for some unique cooling application cases comparing with
solid caloric material. Moreover, this material is sustainable and non-toxic,
which can meet the original intention of the alternative cooling technology.


title: De-pinning of contact line of droplets on rough surfaces

abstract:
  The present study reports the formation of self-assembled droplet pattern on
the PDMS polymer coated over grooved side of DVD under saturated vapours of
alcohols. Comparison of the results with breath figures formed over
unconstrained side of DVD is made. Four different environments namely methanol,
ethanol, 2-propanol and n-butanol are used for the analysis. It is observed
that the pattern formation occurs with methanol and ethanol vapours and not
with 2-propanol and n-butanol. The difference is pattern formation with
different alcohols is attributed to the variation in chain length and the
presence of hydrophobic groups in alcohols, as given by Traube's rule. The
distortion of patterns over constrained surface is attributed to the depinning
of contact lines.


title:
Bethe Ansatz approach to the three-magnon problem in an infinite $XX$
  spin chain with Izing next neighboring ferromagnetic interaction

abstract:
  Using the traditional and degenerative discrete-diffractive versions of Bethe
Ansatz we construct a rude set of three-magnon states in the infinite $XX$ spin
chain with Izing next neighboring ferromagnetic term.


title: On the bracketing entropy condition and generalized empirical measures

abstract:
  We prove a Donsker and a Glivenko--Cantelli theorem for sequences of random
discrete measures generalizing empirical measures. Those two results hold under
standard conditions upon bracketing numbers of the indexing class of functions.
As a byproduct, we derive a posterior consistency and a Bernstein--von Mises
theorem for the Dirichlet process prior, under the topology of total variation,
when the observation space is countable. We also obtain new information about
the Durst--Dudley--Borisov theorem


title:
First results of the Test-Bed Telescopes (TBT) project: Cebreros
  telescope commissioning

abstract:
  The TBT project is being developed under ESA's General Studies and Technology
Programme (GSTP), and shall implement a test-bed for the validation of an
autonomous optical observing system in a realistic scenario within the Space
Situational Awareness (SSA) programme of the European Space Agency (ESA). The
goal of the project is to provide two fully robotic telescopes, which will
serve as prototypes for development of a future network. The system consists of
two telescopes, one in Spain and the second one in the Southern Hemisphere. The
telescope is a fast astrograph with a large Field of View of 2.5 x 2.5
square-degrees and a plate scale of 2.2 arcsec/pixel. The tube is mounted on a
fast direct-drive mount moving with speed up to 20 degrees per second. The
focal plane hosts a 2-port 4K x 4K back-illuminated CCD with readout speeds up
to 1MHz per port. Detection software and hardware are optimised for the
detection of NEOs and objects in high Earth orbits (objects moving from 0.1-40
arcsec/second). Every night it takes all the input needed and prepares a
schedule following predefined rules allocating tasks for the telescopes.
Telescopes are managed by RTS2 control software, that performs the real-time
scheduling of the observation and manages all the devices at the observatory.1
At the end of the night the observing systems report astrometric positions and
photometry of the objects detected. The first telescope was installed in
Cebreros Satellite Tracking Station in mid-2015. We evaluate the site
characteristics and the performance of the TBT Cebreros telescope in the
different modes and strategies. Average residuals for asteroids are under 0.5
arcsecond, while they are around 1 arcsecond for upper-MEO and GEO satellites.
The survey depth is dimmer than magnitude 18.5 for 30-second exposures with the
usual seeing around 4 arcseconds.


title:
Periodicities of the RV Tau-type pulsating star DF Cygni: a combination
  of Kepler data with ground-based observations

abstract:
  The RV Tauri stars constitute a small group of classical pulsating stars with
some dozen known members in the Milky Way. The light variation is caused
predominantly by pulsations, but these alone do not explain the full complexity
of the light curves. High quality photometry of RV Tau-type stars is very rare.
DF Cygni is the only member of this class of stars in the original Kepler
field, hence allowing the most accurate photometric investigation of an RV
Tauri star to date. The main goal is to analyse the periodicities of the RV
Tauri-type star DF Cygni by combining four years of high-quality Kepler
photometry with almost half a century of visual data collected by the American
Association of Variable Star Observers. Kepler quarters of data have been
stitched together to minimize the systematic effects of the space data. The
mean levels have been matched with the AAVSO visual data. Both datasets have
been submitted to Fourier and wavelet analyses, while the stability of the main
pulsations has been studied with the O-C method and the analysis of the
time-dependent amplitudes. DF Cygni shows a very rich behaviour on all
time-scales. The slow variation has a period of 779.606 d and it has been
remarkably coherent during the whole time-span of the combined data. On top of
the long-term cycles the pulsations appear with a period of 24.925 d. Both
types of light variation significantly fluctuate in time, with a constantly
changing interplay of amplitude and phase modulations. The long-period change
(i.e. the RVb signature) somewhat resembles the Long Secondary Period (LSP)
phenomenon of the pulsating red giants, whereas the short-period pulsations are
very similar to those of the Cepheid variables. Comparing the pulsation
patterns with the latest models of Type-II Cepheids, we found evidence of
strong non-linear effects directly observable in the Kepler light curve.


title: $L_p$-Theory of Type $1,1$-Operators

abstract:
  This is a continuation of recent work on the general definition of
pseudo-differential operators of type $1,1$, in H\"ormander's sense. Continuity
in $L_p$-Sobolev spaces and H\"older--Zygmund spaces, and more generally in
Besov and Lizorkin--Triebel spaces, is proved for positive smoothness, with
extension to arbitrary smoothness for operators in the self-adjoint subclass.
As a main tool the paradifferential decomposition is used for type
$1,1$-operators in combination with the Spectral Support Rule for
pseudo-differential operators and pointwise estimates in terms of maximal
functions of Peetre--Fefferman--Stein type.


title: Uncertainty decomposition of quantum networks in SLH framework

abstract:
  This paper presents a systematic method to decompose uncertain linear quantum
input-output networks into uncertain and nominal subnetworks, when
uncertainties are defined in SLH representation. To this aim, two decomposition
theorems are stated, which show how an uncertain quantum network can be
decomposed into nominal and uncertain subnetworks in cascaded connection and
how uncertainties can be translated from SLH parameters into state-space
parameters. As a potential application of the proposed decomposition scheme,
robust stability analysis of uncertain quantum networks is briefly introduced.
The proposed uncertainty decomposition theorems take account of uncertainties
in all three parameters of a quantum network and bridge the gap between SLH
modeling and state-space robust analysis theory for linear quantum networks.


title: Robust Stability of Uncertain Quantum Input-Output Networks

abstract:
  This paper presents a systematic method to analyze stability and robustness
of uncertain Quantum Input-Output Networks (QIONs). A general form of
uncertainty is introduced into quantum networks in the SLH formalism. Results
of this paper are built up on the notion of uncertainty decomposition wherein
the quantum network is decomposed into nominal (certain) and uncertain
sub-networks in cascade connection. Sufficient conditions for robust stability
are derived using two different methods. In the first approach, a generalized
small-gain theorem is presented and in the second approach, robust stability is
analyzed within the framework of Lyapunov theory. In the second method, the
robust stability problem is reformulated as feasibility of a Linear Matrix
Inequality (LMI), which can be examined using the well-established systematic
methods in the literature.


title:
Benchmark solutions for transport in $d$-dimensional Markov binary
  mixtures

abstract:
  Linear particle transport in stochastic media is key to such relevant
applications as neutron diffusion in randomly mixed immiscible materials, light
propagation through engineered optical materials, and inertial confinement
fusion, only to name a few. We extend the pioneering work by Adams, Larsen and
Pomraning \cite{benchmark_adams} (recently revisited by Brantley
\cite{brantley_benchmark}) by considering a series of benchmark configurations
for mono-energetic and isotropic transport through Markov binary mixtures in
dimension $d$. The stochastic media are generated by resorting to Poisson
random tessellations in $1d$ slab, $2d$ extruded, and full $3d$ geometry. For
each realization, particle transport is performed by resorting to the Monte
Carlo simulation. The distributions of the transmission and reflection
coefficients on the free surfaces of the geometry are subsequently estimated,
and the average values over the ensemble of realizations are computed.
Reference solutions for the benchmark have never been provided before for two-
and three-dimensional Poisson tessellations, and the results presented in this
paper might thus be useful in order to validate fast but approximated models
for particle transport in Markov stochastic media, such as the celebrated Chord
Length Sampling algorithm.


title:
Severe signal loss in diamond beam loss monitors in high particle rate
  environments by charge trapping in radiation-induced defects

abstract:
  The beam condition monitoring leakage (BCML) system is a beam monitoring
device in the compact muon solenoid (CMS) experiment at the large hadron
collider (LHC). As detectors 32 poly-crystalline (pCVD) diamond sensors are
positioned in rings around the beam pipe. Here, high particle rates occur from
the colliding beams scattering particles outside the beam pipe. These particles
cause defects, which act as traps for the ionization, thus reducing the charge
collection efficiency (CCE). However, the loss in CCE was much more severe than
expected from low rate laboratory measurements and simulations, especially in
single-crystalline (sCVD) diamonds, which have a low initial concentration of
defects. The reason why in real experiments the CCE is much worse than in
laboratory experiments is related to the ionization rate. At high particle
rates the trapping rate of the ionization is so high compared with the
detrapping rate, that space charge builds up. This space charge reduces locally
the internal electric field, which in turn increases the trapping rate and
recombination and hence reduces the CCE in a strongly non-linear way. A diamond
irradiation campaign was started to investigate the rate dependent electrical
field deformation with respect to the radiation damage. Besides the electrical
field measurements via the Transient Current Technique (TCT), the CCE was
measured. The experimental results were used to create an effective deep trap
model that takes the radiation damage into account. Using this trap model the
rate dependent electrical field deformation and the CCE were simulated with the
software SILVACO TCAD. The simulation, tuned to rate dependent measurements
from a strong radioactive source, was able to predict the non-linear decrease
of the CCE in the harsh environment of the LHC, where the particle rate was a
factor 30 higher.


title: Rejuvenation of metallic glasses under high pressure

abstract:
  Modulating energy states of metallic glasses (MGs) is significant in
understanding the nature of glasses and control their properties. In this
study, we show that rejuvenation in enthalpy can be achieved and preserved in
bulk MGs by using high pressure (HP) annealing, which is a controllable method
to continuously alter the energy states of MGs. Contrary to the decrease in
enthalpy by conventional annealing at ambient pressure, such rejuvenation can
occur and be enhanced by increasing both of annealing temperature and pressure.
By using double aberration corrected scanning transmission electron microscopy,
it is revealed that the rejuvenation, which is attributed to coupling effect of
high pressure and high temperature, originates from the microstructural change
that involves "negative flow units" with a higher atomic packing density
compared to that of the elastic matrix of MGs. The results demonstrate that HP
annealing is an effective way to rejuvenate MGs into higher energy states, and
it may assist in understanding the microstructural origin of the rejuvenation
in MGs.


title:
Gaussian approximations for chemostat models in finite and infinite
  dimensions

abstract:
  In a chemostat, bacteria live in a growth container of constant volume in
which liquid is injected continuously. Recently, Campillo and Fritsch
introduced a mass-structured individual-based model to represent this dynamics
and proved its convergence to a more classic partial differential equation. In
this work, we are interested in the convergence of the fluctuation process. We
consider this process in some Sobolev spaces and use central limit theorems on
Hilbert space to prove its convergence in law to an infinite-dimensional
Gaussian process.As a consequence, we obtain a two-dimensional Gaussian
approximation of the Crump-Young model for which the long time behavior is
relatively misunderstood. For this approximation, we derive the invariant
distribution and the convergence to it. We also present numerical simulations
illustrating our results.


title:
Low cost multi-purpose balloon-borne platform for wide-field imaging and
  video observation

abstract:
  Atmosphere layers, especially the troposphere, hinder the astronomical
observation. For more than 100 years astronomers have tried observing from
balloons to avoid turbulence and extinction. New developments in cardsize
computers, RF equipment and satellite navigation have democratised the access
to the stratosphere. As a result of a ProAm collaboration with the Daedalus
Team we have developed a low-cost multi-purpose platform with stratospheric
balloons carrying up to 3 kg of scientific payload. The Daedalus Team is an
amateur group that has been launching sounding probes since 2010. Since then
the first two authors have provided scienti fic payloads for nighttime flights
with the purpose of technology demonstration for astronomical observation. We
have successfully observed meteor showers (Geminids 2012, Camelopardalis 2014,
Quadrantids 2016 and Lyrids 2016) and city light pollution emission with image
and video sensors covering the 400-1000nm range.


title: L p -norm Sauer-Shelah Lemma for Margin Multi-category Classifiers

abstract:
  In the framework of agnostic learning, one of the main open problems of the
theory of multi-category pattern classification is the characterization of the
way the complexity varies with the number C of categories. More precisely, if
the classifier is characterized only through minimal learnability hypotheses,
then the optimal dependency on C that an upper bound on the probability of
error should exhibit is unknown. We consider margin classifiers. They are based
on classes of vector-valued functions with one component function per category,
and the classes of component functions are uniform Glivenko-Cantelli classes.
For these classifiers, an L p-norm Sauer-Shelah lemma is established. It is
then used to derive guaranteed risks in the L $\infty$ and L 2-norms. These
bounds improve over the state-of-the-art ones with respect to their dependency
on C, which is sublinear.


title: Mass Losing Asymptotic Giant Branch Stars and Supergiants

abstract:
  This paper presents a summary of four invited and twelve contributed
presentations on asymptotic giant branch stars and red supergiants, given over
the course of two afternoon splinter sessions at the 19th Cool Stars Workshop.
It highlights both recent observations and recent theory, with some emphasis on
high spatial resolution, over a wide range of wavelengths. Topics covered
include 3D models, convection, binary interactions, mass loss, dust formation
and magnetic fields.


title: How do walkers avoid a mobile robot crossing their way?

abstract:
  Robots and Humans have to share the same environment more and more often. In
the aim of steering robots in a safe and convenient manner among humans it is
required to understand how humans interact with them. This work focuses on
collision avoidance between a human and a robot during locomotion. Having in
mind previous results on human obstacle avoidance, as well as the description
of the main principles which guide collision avoidance strategies, we observe
how humans adapt a goal-directed locomotion task when they have to interfere
with a mobile robot. Our results show differences in the strategy set by humans
to avoid a robot in comparison with avoiding another human. Humans prefer to
give the way to the robot even when they are likely to pass first at the
beginning of the interaction.


title: A unified model of density limit in fusion plasmas

abstract:
  A limit for the edge density, ruled by radiation losses from light
impurities, is established by a minimal cylindrical magneto-thermal equilibrium
model. For ohmic tokamak and reversed field pinch the limit scales linearly
with the plasma current, as the empirical Greenwald limit. The auxiliary
heating adds a further dependence, scaling with the 0.4 power, in agreement
with L-mode tokamak experiments. For a purely externally heated configuration
the limit takes on a Sudo-like form, depending mainly on the input power, and
is compatible with recent Stellarator scalings.


title:
Level-crossing spectroscopy of nitrogen-vacancy centers in diamond:
  sensitive detection of paramagnetic defect centers

abstract:
  We report a magnetic field dependence of fluorescence of diamond single
crystals containing NV$^-$ centers. In such spectra, numerous sharp lines are
found, which correspond to Level Anti-Crossings (LACs) in coupled spins systems
comprising an NV$^-$ center. Theoretical modeling of such "LAC-spectra" enables
characterization of paramagnetic defect centers and determination of their
magnetic resonance parameters, such as zero-field splitting and hyperfine
coupling constants. The outlined method thus enables sensitive detection of
paramagnetic impurities in diamond crystals.


title:
Binary Hypothesis Testing via Measure Transformed Quasi Likelihood Ratio
  Test

abstract:
  In this paper, the Gaussian quasi likelihood ratio test (GQLRT) for
non-Bayesian binary hypothesis testing is generalized by applying a transform
to the probability distribution of the data. The proposed generalization,
called measure-transformed GQLRT (MT-GQLRT), selects a Gaussian probability
model that best empirically fits a transformed probability measure of the data.
By judicious choice of the transform we show that, unlike the GQLRT, the
proposed test is resilient to outliers and involves higher-order statistical
moments leading to significant mitigation of the model mismatch effect on the
decision performance. Under some mild regularity conditions we show that the
MT-GQLRT is consistent and its corresponding test statistic is asymptotically
normal. A data driven procedure for optimal selection of the measure
transformation parameters is developed that maximizes an empirical estimate of
the asymptotic power given a fixed empirical asymptotic size. A Bayesian
extension of the proposed MT-GQLRT is also developed that is based on selection
of a Gaussian probability model that best empirically fits a transformed
conditional probability distribution of the data. In the Bayesian MT-GQLRT the
threshold and the measure transformation parameters are selected via joint
minimization of the empirical asymptotic Bayes risk. The non-Bayesian and
Bayesian MT-GQLRTs are applied to signal detection and classification, in
simulation examples that illustrate their advantages over the standard GQLRT
and other robust alternatives.


title: Multiplicative LSTM for sequence modelling

abstract:
  We introduce multiplicative LSTM (mLSTM), a recurrent neural network
architecture for sequence modelling that combines the long short-term memory
(LSTM) and multiplicative recurrent neural network architectures. mLSTM is
characterised by its ability to have different recurrent transition functions
for each possible input, which we argue makes it more expressive for
autoregressive density estimation. We demonstrate empirically that mLSTM
outperforms standard LSTM and its deep variants for a range of character level
language modelling tasks. In this version of the paper, we regularise mLSTM to
achieve 1.27 bits/char on text8 and 1.24 bits/char on Hutter Prize. We also
apply a purely byte-level mLSTM on the WikiText-2 dataset to achieve a
character level entropy of 1.26 bits/char, corresponding to a word level
perplexity of 88.8, which is comparable to word level LSTMs regularised in
similar ways on the same task.


title:
Buoyancy effect on the flow pattern and the thermal performance of an
  array of circular cylinders

abstract:
  In this paper we found, by means of numerical simulations, a transition in
the oscillatory character of the flow field for a particular combination of
buoyancy and spacing in an array of six circular cylinders at a Reynolds number
of 100 and Prandtl number of 0.7. The cylinders are iso-thermal and they are
aligned with the Earth acceleration (g). According to the array orientation, an
aiding or an opposing buoyancy is considered. The effect of natural convection
with respect to the forced convection is modulated with the Richardson number,
Ri, ranging between -1 and 1. Two values of center to center spacing (s=3.6d -
4d) are considered. The effects of buoyancy and spacing on the flow pattern in
the near and far field are described. Several transitions in the flow patterns
are found and a parametric analysis of the dependence of the force coefficients
and Nusselt number with respect to the Richardson number is reported. For
Ri=-1, the change of spacing ratio from 3.6 to 4 induces a transition in the
standard deviation of the force coefficients and heat flux. In fact the
transition occurs due to rearrangement of the near field flow in a more ordered
wake pattern. Therefore, attention is focused on the influence of geometrical
and buoyancy parameters on the heat and momentum exchange and their
fluctuations. The available heat exchange models for cylinders array provide a
not accurate prediction of the Nusselt number in the cases here studied.


title: An exhaustive list of isotropic apocalyptic scenarios

abstract:
  We study the possible types of future singularities in the isotropic
homogeneous cosmological models for the arbitrary equation of state of the
contents of the Universe. We obtain all known types of these singularities as
well as two new types using a simple approach. No additional singularity types
are possible. We name the new singularities type "Big Squeeze" and "Little
Freeze". The "Big Squeeze" is possible only in the flat Universe after a finite
time interval. The density of the matter and dark energy tends to zero and its
pressure to minus infinity. This requires the dark energy with a specific
equation of state that has the same asymptotical behaviour at low densities as
the generalised Chaplygin gas. The "Little Freeze" involves an eternal
expansion of the Universe. Some solutions can mimic the $\Lambda$CDM model.


title: $A_p$ weights and Quantitative Estimates in the Schr\"odinger Setting

abstract:
  Suppose $L=-\Delta+V$ is a Schr\"odinger operator on $\mathbb{R}^n$ with a
potential $V$ belonging to certain reverse H\"older class $RH_\sigma$ with
$\sigma\geq n/2$. The aim of this paper is to study the $A_p$ weights
associated to $L$, denoted by $A_p^L$, which is a larger class than the
classical Muckenhoupt $A_p$ weights. We first establish the "exp--log" link
between $A_p^L$ and $BMO_L$ (the BMO space associated with $L$), which is the
first extension of the classical result to a setting beyond the Laplace
operator. Second, we prove the quantitative $A_p^L$ bound for the maximal
function and the maximal heat semigroup associated to $L$. Then we further
provide the quantitative $A_{p,q}^L$ bound for the fractional integral operator
associated to $L$. We point out that all these quantitative bounds are known
before in terms of the classical $A_{p,q}$ constant. However, since
$A_{p,q}\subset A_{p,q}^L$, the $A_{p,q}^L$ constants are smaller than
$A_{p,q}$ constant. Hence, our results here provide a better quantitative
constant for maximal functions and fractional integral operators associated to
$L$.


title: Vacuum energies and multipole interactions

abstract:
  In this paper, we present a quantum-field-theoretical description of the
interaction between stationary and localized external sources linearly coupled
to bosonic fields (specifically, we study models with a scalar and the Maxwell
field). We consider external sources that simulate not only point charges but
also higher-multipole distributions along D-dimensional branes. Our results
complement the ones previously obtained in reference [1].