title:
Stationary measures for two dual families of finite and zero temperature
  models of directed polymers on the square lattice

abstract:
  We study the recently introduced Inverse-Beta polymer, an exactly solvable,
anisotropic finite temperature model of directed polymer on the square lattice,
and obtain its stationary measure. In parallel we introduce an anisotropic zero
temperature model of directed polymer on the square lattice, the
Bernoulli-Geometric polymer, and obtain its stationary measure. This new
exactly solvable model is dual to the Inverse-Beta polymer and interpolates
between models of first and last passage percolation on the square lattice.
Both stationary measures are shown to satisfy detailed balance. We also obtain
the asymptotic mean value of (i) the free-energy of the Inverse-Beta polymer;
(ii) the optimal energy of the Bernoulli-Geometric polymer. We discuss the
convergence of both models to their stationary state. We perform simulations of
the Bernoulli-Geometric polymer that confirm our results.

categories: cond-mat.dis-nn cond-mat.stat-mech math-ph math.MP


title:
Recent Pythia 8 developments: Hard diffraction, Colour reconnection and
  $\gamma\gamma$ collisions

abstract:
  An overview of recent developments in \pythia~8 is given. First the new hard
diffraction model, which is implemented as a part of the multiparton
interactions (MPI) framework, is discussed. Then the new colour reconnection
model, which includes beyond leading colour effects that can become important
when MPI are present, is briefly reviewed. As a last topic an introduction is
given to our implementation of photon-photon collisions. In particular photon
PDFs, required modifications for the initial state radiation algorithm and beam
remnant handling with photon beams is discussed.


title: Knowledge Ratings in MetaboLights

abstract:
  This technical report presents an evaluation of the ontology annotations in
the metadata of a subset of entries of MetaboLights, a database for
Metabolomics experiments and derived information. The work includes a manual
analysis of the entries and a comprehensive qualitative evaluation of their
annotations, together with the evaluation guide and its rationale, that was
defined and followed. The approach was also implemented as a software script
that given a MetaboLights entry returns a quantitative evaluation of the
quality of its annotations (available on request).


title: The problem of coherent control in non-Markovian open quantum systems

abstract:
  We critically evaluate the most widespread assumption in the theoretical
description of coherent control strategies for open quantum systems. We show
that, for non-Markovian open systems dynamics, this fixed-dissipator assumption
leads to a serious pitfall causing insurmountable difficulties in the effective
modelling of the controlled system. We show that the only way to avoid these
problems is a full microscopic description of the controlled system in presence
of noise. We illustrate our findings with a paradigmatic example.


title:
Gravitational waveforms from binary neutron star mergers with high-order
  WENO schemes in numerical relativity

abstract:
  The theoretical modeling of gravitational waveforms from binary neutron star
mergers requires precise numerical relativity simulations. Assessing
convergence of the numerical data and building the error budget is currently
challenging due to the low accuracy of general-relativistic hydrodynamics
schemes and to the grid resolutions that can be employed in $(3+1)$-dimensional
simulations. In this work, we explore the use of high-order
weighted-essentially-nonoscillatory (WENO) schemes in neutron star merger
simulations and investigate the accuracy of the waveforms obtained with such
methods. We find that high-order WENO schemes can be robustly employed for
simulating the inspiral-merger phase and they significantly improve the
assessment of the waveform's error budget with respect to finite-volume
methods. High-order WENO schemes can be thus efficiently used for high-quality
waveforms production, also in future large-scale investigations of the binary
parameter space.


title: Twists of $GL(3)$ $L$-functions

abstract:
  Let $\pi$ be a $SL(3,\mathbb Z)$ Hecke-Maass cusp form, and let $\chi$ be a
primitive Dirichlet character modulo $M$, which we assume to be prime. In this
note we revisit the subconvexity problem addressed in `The circle method and
bounds for $L$-functions IV' and establish the following unconditional bound
\begin{align*} L\left(\tfrac{1}{2},\pi\otimes\chi\right)\ll
M^{3/4-1/308+\varepsilon}. \end{align*}


title: Context Tree based Image Contour Coding using A Geometric Prior

abstract:
  If object contours in images are coded efficiently as side information, then
they can facilitate advanced image / video coding techniques, such as graph
Fourier transform coding or motion prediction of arbitrarily shaped pixel
blocks. In this paper, we study the problem of lossless and lossy compression
of detected contours in images. Specifically, we first convert a detected
object contour composed of contiguous between-pixel edges to a sequence of
directional symbols drawn from a small alphabet. To encode the symbol sequence
using arithmetic coding, we compute an optimal variable-length context tree
(VCT) $\mathcal{T}$ via a maximum a posterior (MAP) formulation to estimate
symbols' conditional probabilities. MAP prevents us from overfitting given a
small training set $\mathcal{X}$ of past symbol sequences by identifying a VCT
$\mathcal{T}$ that achieves a high likelihood $P(\mathcal{X}|\mathcal{T})$ of
observing $\mathcal{X}$ given $\mathcal{T}$, and a large geometric prior
$P(\mathcal{T})$ stating that image contours are more often straight than
curvy. For the lossy case, we design efficient dynamic programming (DP)
algorithms that optimally trade off coding rate of an approximate contour
$\hat{\mathbf{x}}$ given a VCT $\mathcal{T}$ with two notions of distortion of
$\hat{\mathbf{x}}$ with respect to the original contour $\mathbf{x}$. To reduce
the size of the DP tables, a total suffix tree is derived from a given VCT
$\mathcal{T}$ for compact table entry indexing, reducing complexity.
Experimental results show that for lossless contour coding, our proposed
algorithm outperforms state-of-the-art context-based schemes consistently for
both small and large training datasets. For lossy contour coding, our
algorithms outperform comparable schemes in the literature in rate-distortion
performance.


title:
Testing the concordance model in cosmology with model-independent
  methods: some issues

abstract:
  Since the number of dark energy models have rapidly increased over the last
years, some model-independent methods have been developed in order to analyse
the cosmological evolution in a phenomenological way. In this manuscript, we
analyse some of these approaches and their shortcomings to provide reliable
information.


title:
Crystal structure, stability and optoelectronic properties of the
  organic-inorganic wide bandgap perovskite CH3NH3BaI3: Candidate for
  transparent conductor applications

abstract:
  Structural stability, electronic structure and optical properties of
CH3NH3BaI3 hybrid perovskite is examined both from theory as well as
experiment. Solution-processed thin films of CH3NH3BaI3 exhibited a high band
gap of approximately 3.87 eV, which is in excellent agreement with the
theoretical estimate of 4 eV. Also, the XRD patterns of the thin films match
well with the l-peaks of the simulated pattern obtained from the relaxed unit
cell of CH3NH3BaI3, crystallizing in the I4/mcm space group, with lattice
parameters, a = 9.30 A, c = 13.94 A. Atom projected density of state and band
structure calculations reveal the conduction and valence band edges to be
comprised primarily of Barium d-orbitals and Iodine p-orbitals, respectively.
The larger band gap of CH3NH3BaI3 compared to CH3NH3PbI3 can be attributed to
the lower electro-negativity coupled with the lack of d-orbitals in the valence
band of Ba{2+}. A more detailed analysis reveals the excellent chemical and
mechanical stability of CH3NH3BaI3 against humidity, unlike its lead halide
counterpart, which degrades under such conditions. The dopability of the
CH3NH3BaI3 compound e.g. by doping La on the Ba site combined with its
structural and mechanical stability under the ambient conditions, suggests this
compound as a promising candidate for transparent conductor applications,
especially for all perovskite solar cells.


title:
An Analytical Solution for Probabilistic Guarantees of Reservation Based
  Soft Real-Time Systems

abstract:
  We show a methodology for the computation of the probability of deadline miss
for a periodic real-time task scheduled by a resource reservation algorithm. We
propose a modelling technique for the system that reduces the computation of
such a probability to that of the steady state probability of an infinite state
Discrete Time Markov Chain with a periodic structure. This structure is
exploited to develop an efficient numeric solution where different
accuracy/computation time trade-offs can be obtained by operating on the
granularity of the model. More importantly we offer a closed form conservative
bound for the probability of a deadline miss. Our experiments reveal that the
bound remains reasonably close to the experimental probability in one real-time
application of practical interest. When this bound is used for the optimisation
of the overall Quality of Service for a set of tasks sharing the CPU, it
produces a good sub-optimal solution in a small amount of time.


title:
Geometric and Kinematic Structure of the Outflow/Envelope System of
  L1527 Revealed by Subarcsecond-resolution Observation of CS

abstract:
  Subarcsecond-resolution images of the rotational line emissions of CS and
c-C$_3$H$_2$ obtained toward the low-mass protostar IRAS 04368$+$2557 in L1527
with the Atacama Large Millimeter/submillimeter Array are investigated to
constrain the orientation of the outflow/envelope system. The distribution of
CS consists of an envelope component extending from north to south and a faint
butterfly-shaped outflow component. The kinematic structure of the envelope is
well reproduced by a simple ballistic model of an infalling rotating envelope.
Although the envelope has a nearly edge-on configuration, the inclination angle
of the rotation axis from the plane of the sky is found to be 5$^\circ$, where
we find that the western side of the envelope faces the observer. This
configuration is opposite to the direction of the large-scale ($\sim$ 10$^4$
AU) outflow suggested previously from the $^{12}$CO ($J$=3$-$2) observation,
and to the morphology of infrared reflection near the protostar ($\sim$ 200
AU). The latter discrepancy could originate from high extinction by the outflow
cavity of the western side, these discrepancies or may indicate that the
outflow axis is not parallel to the rotation axis of the envelope.
Position-velocity diagrams show the accelerated outflow cavity wall, and its
kinematic structure in the 2000 AU scale is explained by a standard parabolic
model with the inclination angle derived from the analysis of the envelope. The
different orientation of the outflow between the small and large scale implies
a possibility of precession of the outflow axis. The shape and the velocity of
the outflow in the vicinity of the protostar are compared with those of other
protostars.


title: Symmetric multiplicative formality of the Kontsevich operad

abstract:
  In his famous paper entitled "Operads and motives in deformation
quantization", Maxim Kontsevich constructed (in order to prove the formality of
the little d-disks operad) a topological operad, which is called in the
literature the Kontsevich operad, and which is denoted Kd in this paper. This
operad has a nice structure: it is a multiplicative symmetric operad, that is,
it comes with a morphism from the symmetric associative operad. There are many
results in the literature concerning the formality of Kd. It is well known (by
Kontsevich) that Kd is formal over reals as a symmetric operad. It is also well
known that Kd is formal as a multiplicative nonsymmetric operad. In this paper,
we prove that the Kontsevich operad is formal over reals as a multiplicative
symmetric operad, when d > 2.


title:
A state-dependent vector control for a West Nile Virus model from
  mosquitoes to birds

abstract:
  In this paper, a novel West Nile Virus model looking upon the infected birds
as monitoring threshold, for the mosquitoes and birds with impulsive state
feedback control is considered. We obtain sufficient conditions of the global
asymptotical stability of the system without impulsive state feedback control
via comprehensively qualitative analysis. By using the Poincar\'e map, we
obtain that the system with impulsive state feedback control has a positive
periodic solution of order-1 or order-2 which is asymptotical stability due to
the analogue of Poincar\'e criterion, theory of differential inequalities,
differential equation geometry and so on. What's more, sufficient conditions
for existence and stability of the order one periodic solution are given by the
existence and uniqueness of the limit. Our results show that the control
measure is effective and feasible by means of numerical simulations.


title:
Improved Statistical Determination of Absolute Neutrino Masses via
  Radiative Emission of Neutrino Pairs from Atoms

abstract:
  The atomic transition from an excited state $|{\rm e}\rangle$ to the ground
state $|{\rm g}\rangle$ by emitting a neutrino pair and a photon, i.e., $|{\rm
e}\rangle \to |{\rm g}\rangle + |\gamma\rangle + |\nu^{}_i\rangle +
|\bar{\nu}^{}_j\rangle$ with $i, j = 1, 2, 3$, has been proposed by Yoshimura
and his collaborators as an alternative way to determine the absolute scale
$m^{}_0$ of neutrino masses. More recently, a statistical analysis of the fine
structure of the photon spectrum from this atomic process has been performed
[N. Song {\it et al.}, Phys.\ Rev.\ D {\bf 93}, 013020 (2016)] to
quantitatively examine the experimental requirements for a realistic
determination of absolute neutrino masses. In this paper, we show how to
improve the statistical analysis and demonstrate that the previously required
detection time can be reduced by one order of magnitude for the case of a
$3\sigma$ determination of $m_0^{} \sim 0.01~\text{eV}$ with an accuracy better
than $10\%$. Such an improvement is very encouraging for further investigations
on measuring absolute neutrino masses through atomic processes.


title:
Entropies in General Probabilistic Theories and its Application to
  Holevo Bound

abstract:
  General probabilistic theories are designed to provide operationally the most
general probabilistic models including both classical and quantum theories. In
this letter, we introduce a systematic method to construct a series of
entropies, all of which generalize Shannon entropy in classical system and von
Neumann entropy in quantum system. Using these entropies, the Holevo bound, an
upper bound of the accessible information from a quantum system, is generalized
to hold in any general probabilistic theory.


title: Deep Learning for Saliency Prediction in Natural Video

abstract:
  The purpose of this paper is the detection of salient areas in natural video
by using the new deep learning techniques. Salient patches in video frames are
predicted first. Then the predicted visual fixation maps are built upon them.
We design the deep architecture on the basis of CaffeNet implemented with Caffe
toolkit. We show that changing the way of data selection for optimisation of
network parameters, we can save computation cost up to 12 times. We extend deep
learning approaches for saliency prediction in still images with RGB values to
specificity of video using the sensitivity of the human visual system to
residual motion. Furthermore, we complete primary colour pixel values by
contrast features proposed in classical visual attention prediction models. The
experiments are conducted on two publicly available datasets. The first is
IRCCYN video database containing 31 videos with an overall amount of 7300
frames and eye fixations of 37 subjects. The second one is HOLLYWOOD2 provided
2517 movie clips with the eye fixations of 19 subjects. On IRCYYN dataset, the
accuracy obtained is of 89.51%. On HOLLYWOOD2 dataset, results in prediction of
saliency of patches show the improvement up to 2% with regard to RGB use only.
The resulting accuracy of 76, 6% is obtained. The AUC metric in comparison of
predicted saliency maps with visual fixation maps shows the increase up to 16%
on a sample of video clips from this dataset.


title: Growth and dissolution of macromolecular Markov chains

abstract:
  The kinetics and thermodynamics of free living copolymerization are studied
for processes with rates depending on k monomeric units of the macromolecular
chain behind the unit that is attached or detached. In this case, the sequence
of monomeric units in the growing copolymer is a kth-order Markov chain. In the
regime of steady growth, the statistical properties of the sequence are
determined analytically in terms of the attachment and detachment rates. In
this way, the mean growth velocity as well as the thermodynamic entropy
production and the sequence disorder can be calculated systematically. These
different properties are also investigated in the regime of depolymerization
where the macromolecular chain is dissolved by the surrounding solution. In
this regime, the entropy production is shown to satisfy Landauer's principle.


title:
Cycle Chacterization of the Aubry Set for Weakly Coupled Hamilton-Jacobi
  Systems

abstract:
  We study a class of weakly coupled systems of Hamilton-acobi equations using
the random frame introduced in a previous paper of
Mitake-Siconolfi-Tran-Yamada. We provide a cycle condition characterizing the
points of Aubry set. This generalizes a property already known in the scalar
case.


title: High-Energy Resummation in Di-hadron Production at the LHC

abstract:
  We propose to study at the Large Hadron Collider (LHC) the inclusive
production of a pair of hadrons (a "di-hadron" system) in a kinematics where
two detected hadrons with high transverse momenta are separated by a large
interval of rapidity. This process has much in common with the widely discussed
Mueller-Navelet jet production and can also be used to access the dynamics of
hard proton-parton interactions in the Regge limit. For both processes large
contributions enhanced by logarithms of energy can be resummed in perturbation
theory within the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism with
next-to-leading logarithmic accuracy (NLA). The experimental study of di-hadron
production would provide with an additional clear channel to test the BFKL
dynamics. We present here the first theoretical predictions for cross sections
and azimuthal angle correlations of the di-hadrons produced with LHC
kinematics.


title:
Fractal Tube Formulas for Compact Sets and Relative Fractal Drums:
  Oscillations, Complex Dimensions and Fractality

abstract:
  We establish pointwise and distributional fractal tube formulas for a large
class of relative fractal drums in Euclidean spaces of arbitrary dimensions. A
relative fractal drum (or RFD, in short) is an ordered pair $(A,\Omega)$ of
subsets of the Euclidean space (under some mild assumptions) which generalizes
the notion of a (compact) subset and that of a fractal string. By a fractal
tube formula for an RFD $(A,\Omega)$, we mean an explicit expression for the
volume of the $t$-neighborhood of $A$ intersected by $\Omega$ as a sum of
residues of a suitable meromorphic function (here, a fractal zeta function)
over the complex dimensions of the RFD $(A,\Omega)$. The complex dimensions of
an RFD are defined as the poles of its meromorphically continued fractal zeta
function (namely, the distance or the tube zeta function), which generalizes
the well-known geometric zeta function for fractal strings. These fractal tube
formulas generalize in a significant way to higher dimensions the corresponding
ones previously obtained for fractal strings by the first author and van
Frankenhuijsen and later on, by the first author, Pearse and Winter in the case
of fractal sprays. They are illustrated by several interesting examples. These
examples include fractal strings, the Sierpi\'nski gasket and the 3-dimensional
carpet, fractal nests and geometric chirps, as well as self-similar fractal
sprays. We also propose a new definition of fractality according to which a
bounded set (or RFD) is considered to be fractal if it possesses at least one
nonreal complex dimension or if its fractal zeta function possesses a natural
boundary. This definition, which extends to RFDs and arbitrary bounded subsets
of $\mathbb{R}^N$ the previous one introduced in the context of fractal
strings, is illustrated by the Cantor graph (or devil's staircase) RFD, which
is shown to be `subcritically fractal'.


title: Zeros of the first derivative of Dirichlet $L$-functions

abstract:
  Y\i ld\i r\i m has classified zeros of the derivatives of Dirichlet
$L$-functions into trivial zeros, nontrivial zeros and vagrant zeros. In this
paper we remove the possibility of vagrant zeros for $L'(s,\chi)$ when the
conductors are large to some extent. Then we improve asymptotic formulas for
the number of zeros of $L'(s,\chi)$ in
$\{s\in\mathbb{C}:\operatorname{Re}(s)>0, |\operatorname{Im}(s)|\leq T\}$. We
also establish analogues of Speiser's theorem, which characterize the
generalized Riemann hypothesis for $L(s,\chi)$ in terms of zeros of
$L'(s,\chi)$, when the conductor is large.


abstract:
  We propose Adaptive Incremental Mixture Markov chain Monte Carlo (AIMM), a
novel approach to sample from challenging probability distributions defined on
a general state-space. While adaptive MCMC methods usually update a parametric
proposal kernel with a global rule, AIMM locally adapts a semiparametric
kernel. AIMM is based on an independent Metropolis-Hastings proposal
distribution which takes the form of a finite mixture of Gaussian
distributions. Central to this approach is the idea that the proposal
distribution adapts to the target by locally adding a mixture component when
the discrepancy between the proposal mixture and the target is deemed to be too
large. As a result, the number of components in the mixture proposal is not
fixed in advance. Theoretically, we prove that there exists a process that can
be made arbitrarily close to AIMM and that converges to the correct target
distribution. We also illustrate that it performs well in practice in a variety
of challenging situations, including high-dimensional and multimodal target
distributions.


title:
Some aspects of the interplay between bipartite correlations and quantum
  channels

abstract:
  This thesis explores ways in which quantum channels and correlations (of both
classical and quantum types) manifest themselves, and also studies the
interplay between these two aspects in various physical settings. Quantum
channels represent all possible evolutions of states allowed by quantum
mechanics while correlations are intrinsic (nonlocal) properties of composite
systems. There are four main problems that are addressed (i) the role played by
initial system-bath correlations on the subsystem dynamics of an open quantum
system, (ii) computation of correlations for two-qubit X-states, (iii) the
robustness of non-Gaussian entanglement under symmetric local noisy attenuator
and amplifier channels, and finally, (iv) the connection between
nonclassicality breaking and entanglement breaking for single-mode bosonic
Gaussian channels.


title:
First- and second-order phase transitions between the uniform and FFLO
  excitonic states in the three-chain Hubbard model for Ta2NiSe5

abstract:
  We examine the free energy and the thermodynamic properties in the
three-chain Hubbard model for Ta2NiSe5 to clarify the phase transitions between
the uniform and the FFLO excitonic states which are expected to be observed in
Ta2NiSe5 under high pressure.


title:
A parallel code for multiprecision computations of the Lane-Emden
  differential equation

abstract:
  We compute multiprecision solutions of the Lane-Emden equation. This
differential equation arises when introducing the well-known polytropic model
into the equation of hydrostatic equilibrium for a nondistorted star. Since
such multiprecision computations are time-consuming, we apply to this problem
parallel programming techniques and thus the execution time of the computations
is drastically reduced.


title: Time-resolved Scattering of a Single Photon by a Single Atom

abstract:
  Scattering of light by matter has been studied extensively in the past. Yet,
the most fundamental process, the scattering of a single photon by a single
atom, is largely unexplored [1-3]. One prominent prediction of quantum optics
is the deterministic absorption of a traveling photon by a single atom,
provided the photon waveform matches spatially and temporally the time-reversed
version of a spontaneously emitted photon [4-12]. Here, we experimentally
address this prediction and investigate the influence of the temporal profile
of the photon on the scattering dynamics using a single trapped atom and
heralded single photons. In a time-resolved measurement of the atomic
excitation we find a 56(11)% increase of the peak excitation by photons with an
exponentially rising profile compared to a decaying one. This result
demonstrates that tailoring the envelope of single photons enables precise
control of the photon-atom interaction.


title:
Isobaric heat capacity, isothermal compressibility and fluctuational
  properties of 1-bromoalkanes

abstract:
  We present results of the experimental measurements of the isobaric heat
capacity for 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane,
1-bromodecane, 1-bromoundecane, 1-bromododecane and 1-bromo-tetradecane at
normal pressure and the speed of sound and the density for 1-bromotetradecane
within the temperature range 298.15--423.15~K. These data on the isobaric heat
capacity and the literature-based reference data for the density and the speed
of sound were used to calculate the isothermal compressibility and the inverse
reduced fluctuations. Based on the comparison of the results for pure n-alkanes
and $\alpha,\omega$-dibromoalkanes, we discuss the influence of bromine atom on
the volume fluctuations.


title:
On the Optical -- X-ray correlation from outburst to quiescence in Low
  Mass X-ray Binaries: the representative cases of V404 Cyg and Cen X-4

abstract:
  Low mass X-ray binaries (LMXBs) show evidence of a global correlation of
debated origin between X-ray and optical luminosity. We study for the first
time this correlation in two transient LMXBs, the black hole V404 Cyg and the
neutron star Cen X-4, over 6 orders of magnitude in X-ray luminosity, from
outburst to quiescence. After subtracting the contribution from the companion
star, the Cen X-4 data can be described by a single power law correlation of
the form $L_{opt}\propto\,L_{X}^{0.44}$, consistent with disk reprocessing. We
find a similar correlation slope for V404 Cyg in quiescence (0.46) and a
steeper one (0.56) in the outburst hard state of 1989. However, V404 Cyg is
about $160-280$ times optically brighter, at a given $3-9$ keV X-ray
luminosity, compared to Cen X-4. This ratio is a factor of 10 smaller in
quiescence, where the normalization of the V404 Cyg correlation also changes.
We show that once the bolometric X-ray emission is considered and the known
main differences between V404 Cyg and Cen X-4 are taken into account (a larger
compact object mass, accretion disk size, and the presence of a strong jet
contribution in the hard state for the black hole system) the two systems lie
on the same correlation. In V404 Cyg, the jet dominates spectrally at
optical-infrared frequencies during the hard state, but makes a negligible
contribution in quiescence, which may account for the change in its correlation
slope and normalization. These results provide a benchmark to compare with data
from the 2015 outburst of V404 Cyg and, potentially, other transient LMXBs as
well.


title:
Semiclassical bifurcations and topological phase transitions in a
  one-dimensional lattice of coupled Lipkin-Meshkov-Glick models

abstract:
  In this work we study a one-dimensional lattice of Lipkin-Meshkov-Glick
models with alternating couplings between nearest-neighbors sites, which
resembles the Su-Schrieffer-Heeger model. Typical properties of the underlying
models are present in our semiclassical-topological hybrid system, allowing us
to investigate an interplay between semiclassical bifurcations at mean-field
level and topological phases. Our results show that bifurcations of the energy
landscape lead to diverse ordered quantum phases. Furthermore, the study of the
quantum fluctuations around the mean field solution reveals the existence of
nontrivial topological phases. These are characterized by the emergence of
localized states at the edges of a chain with open boundary conditions.


title: Globular clusters indicate ultra diffuse galaxies are dwarfs

abstract:
  We present an analysis of archival {\it HST/ACS} imaging in the F475W
($g_{475}$), F606W ($V_{606}$) and F814W ($I_{814}$) bands of the globular
cluster (GC) system of a large (3.4 kpc effective radius) ultra-diffuse galaxy
(DF17) believed located in the Coma Cluster of galaxies. We detect 11 GCs down
to the 5$\sigma$ completeness limit of the imaging ($I_{814}=$27 mag).
Correcting for background and our detection limits yields a total population of
GCs in this galaxy of $27\pm5$ and a $V$-band specific frequency, $S_N=28\pm5$.
Based on comparisons to the GC systems of Local galaxies, we show that both the
absolute number and the colors of the GC system of DF17 are consistent with the
GC system of a dark-matter dominated dwarf galaxy with virial mass
$\sim0.9\times10^{10}$~\msun and a dark-to-stellar mass ratio, $M_{vir} / M_{
star}\sim 1000$. Based on the stellar mass-growth of the Milky Way, we show
that DF17 cannot be understood as a failed Milky Way-like system, but is more
similar to quenched Large Magellanic Cloud-like systems. We find that the mean
color of GC population, $g_{475}-I_{814}$ = $0.91\pm0.05$ mag, coincides with
the peak of the color distribution of intracluster GCs and are also similar to
those of the blue GCs in the outer regions of massive galaxies. We suggest that
both the intracluster GC population in Coma and the blue-peak in the GC
populations of massive galaxies may be fed - at least in part - by the
disrupted equivalents of systems such as DF17.


title:
History dependence of the magnetic properties of single-crystal
  Fe$_{1-x}$Co$_{x}$Si

abstract:
  We report the magnetization, ac susceptibility, and specific heat of
optically float-zoned single crystals of Fe$_{1-x}$Co$_{x}$Si, $0.20 \leq x
\leq 0.50$. We determine the magnetic phase diagrams for all major
crystallographic directions and cooling histories. After zero-field cooling,
the phase diagrams resemble that of the archetypal stoichiometric cubic chiral
magnet MnSi. Besides the helical and conical state, we observe a pocket of
skyrmion lattice phase just below the helimagnetic ordering temperature. At the
phase boundaries between these states evidence for slow dynamics is observed.
When the sample is cooled in small magnetic fields, the phase pocket of
skyrmion lattice may persist metastably down to lowest temperatures. Taken
together with the large variation of the transition temperatures, transition
fields, and the helix wavelength as a function of composition, this hysteresis
identifies Fe$_{1-x}$Co$_{x}$Si as an ideal material for future experiments
exploring, for instance, the topological unwinding of the skyrmion lattice.


title: Lepton mixing patterns from combinations of elementary correlations

abstract:
  Recent data of reactor neutrino experiments set more stringent constraint on
leptonic mixing patterns. We examine all possible patterns on the basis of
combinations of elementary correlations of elements of leptonic mixing matrix.
we obtain 62 viable mixing patters at 3$\sigma$ level of mixing parameters.
Most of these patterns can be paired via the {\mu}- interchange which changes
the octant of $\theta_{23}$ and the sign of $\cos{\delta}$. All viable patterns
can be classified into two groups: the perturbative patterns and
non-perturbative patterns. The former can be obtained from perturbing TBM. The
latter cannot be obtained from perturbing any mixing pattern whose
$\theta_{13}$ is zero. Different predictions of Dirac CP phase $\delta$ of
these two types of mixing patterns are discussed. Evolutions of mass matrices
of neutrinos with small mixing parameters are discussed via special mixing
patterns on the basis of flavor groups. In general cases, a small variation of
$\sin\theta_{13}$ may bring about large modifications to alignment of vacuum
expectation values in a mixing model. Therefore, small but nonzero
$\sin\theta_{13}$ brings a severer challenge to leptonic mixing models on the
basis of flavor groups than usual views.


title: Massless scalar Feynman diagrams: five loops and beyond

abstract:
  Several powerful techniques for evaluating massless scalar Feynman diagrams
are developed, viz: the solution of recurrence relations to evaluate diagrams
with arbitrary numbers of loops in $n=4-2\omega$ dimensions; the discovery and
use of symmetry properties to restrict and compute Taylor series in $\omega$;
the reduction of triple sums over Chebyshev polynomials to products of Riemann
zeta functions; the exploitation of conformal invariance to avoid
four-dimensional Racah coefficients. As an example of the power of these
techniques we evaluate all of the 216 diagrams, with 5 loops or less, which
give finite contributions of order $1/k^2$ or $1/k^4$ to a propagator of
momentum $k$ in massless four-dimensional scalar field theories. Remarkably,
only 5 basic numbers are encountered: $\zeta(3)$, $\zeta(5)$, $\zeta(7)$,
$\zeta(9)$ and the value of the most symmetrical diagram, which is calculated
to 14 significant figures. It is conceivable that these are the only
irrationals appearing in 6-loop beta functions. En route to these results we
uncover and only partially explain many remarkable relations between diagrams.


title: Plasma rotation from momentum transport by neutrals in tokamaks

abstract:
  Neutral atoms can strongly influence the intrinsic rotation and radial
electric field at the tokamak edge. Here, we present a framework to investigate
these effects when the neutrals dominate the momentum transport. We explore the
parameter space numerically, using highly flexible model geometries and a state
of the art kinetic solver. We find that the most important parameters
controlling the toroidal rotation and electric field are the major radius where
the neutrals are localized and the plasma collisionality. This offers a means
to influence the rotation and electric field by, for example, varying the
radial position of the X-point to change the major radius of the neutral peak.


title:
The Dirichlet problem for a complex Hessian equation on compact
  Hermitian manifolds with boundary

abstract:
  We solve the classical Dirichlet problem for a general complex Hessian
equation on a small ball in $\bC^n$. Then, we show that there is a continuous
solution, in pluripotential theory sense, to the Dirichlet problem on compact
Hermitian manifolds with boundary that equipped locally conformal K\"ahler
metrics, provided a subsolution.


title:
Nonlinear response of the quantum Hall system to a strong
  electromagnetic radiation

abstract:
  We study nonlinear response of a quantum Hall system in
semiconductor-heterostructures via third harmonic generation process and
nonlinear Faraday effect. We demonstrate that Faraday rotation angle and third
harmonic radiation intensity have a characteristic Hall plateaus feature. These
nonlinear effects remain robust against the significant broadening of Landau
levels. We predict realization of an experiment through the observation of the
third harmonic signal and Faraday rotation angle, which are within the
experimental feasibility.


title: The power of the resource theory of genuine quantum coherence

abstract:
  Any quantum resource theory is based on free states and free operations,
i.e., states and operations which can be created and performed at no cost. In
the resource theory of coherence free states are diagonal in some fixed basis,
and free operations are those which cannot create coherence for some particular
experimental realization. Recently, some problems of this approach have been
discussed, and new sets of operations have been proposed to resolve these
problems. As an example for such a problem, a quantum operation can be
incoherent in one particular experimental realization, but it still can create
large amount of coherence in another. This problem is resolved by the framework
of genuine quantum coherence. Here, we investigate this concept further and
study other more general sets of operations which cannot create coherence in
any experimental realization. We analyze in detail the mathematical structure
of this class of maps and use this to study possible state transformations
under these operations. We show that deterministic manipulation is severely
limited, even in the asymptotic settings. In particular, this framework does
not have a unique golden unit, i.e., there is no single state from which all
other states can be created deterministically with the free operations. On the
other hand, we show that these theories allow for a richer structure in what
comes to stochastic manipulation of states. In particular, we determine the
optimal probability of conversion among pure states with genuinely incoherent
operations. Still, the aforementioned limitations suggest that any reasonably
powerful resource theory of coherence must contain free operations which can
potentially create coherence in some experimental realization.


title: Scale Factor Duality for Conformal Cyclic Cosmologies

abstract:
  The scale factor duality is a symmetry of dilaton gravity which is known to
lead to pre-big-bang cosmologies. A conformal time version of the scale factor
duality (SFD) was recently implemented as a UV/IR symmetry between decelerated
and accelerated phases of the post-big-bang evolution within Einstein gravity
coupled to a scalar field. The problem investigated in the present paper
concerns the employment of the conformal time SFD methods to the construction
of pre-big-bang and cyclic extensions of these models. We demonstrate that each
big-bang model gives rise to two qualitatively different pre-big-bang
evolutions: a contraction/expansion SFD model and Penrose's Conformal Cyclic
Cosmology (CCC). A few examples of SFD symmetric cyclic universes involving
certain gauged K\"ahler sigma models minimally coupled to Einstein gravity are
studied. We also describe the specific SFD features of the thermodynamics and
the conditions for validity of the generalized second law in the case of
Gauss-Bonnet (GB) extension of these selected CCC models.


title:
Polyelectrolyte assisted charge titration spectrometry: applications to
  latex and oxide nanoparticles

abstract:
  The electrostatic charge density of particles is of paramount importance for
the control of the dispersion stability. Conventional methods use
potentiometric, conductometric or turbidity titration but require large amount
of samples. Here we report a simple and cost-effective method called
polyelectrolyte assisted charge titration spectrometry or PACTS. The technique
takes advantage of the propensity of oppositely charged polymers and particles
to assemble upon mixing, leading to aggregation or phase separation. The mixed
dispersions exhibit a maximum in light scattering as a function of the
volumetric ratio X, and the peak position XMax is linked to the particle charge
density according to {\sigma} ~ D0 XMax where D0 is the particle diameter. The
PACTS is successfully applied to organic latex, aluminum and silicon oxide
particles of positive or negative charge using poly(diallyldimethylammonium
chloride) and poly(sodium 4-styrenesulfonate). The protocol is also optimized
with respect to important parameters such as pH and concentration, and to the
polyelectrolyte molecular weight. The advantages of the PACTS technique are
that it requires minute amounts of sample and that it is suitable to a broad
variety of charged nano-objects.


title: Non-inner automorphisms of order p in finite p-groups of coclass 3

abstract:
  In this paper we study the existence of at least one non-inner automorphism
of order p of a non-abelian finite p-group of coclass 3, where p is a prime
integer such that p is different from 3.


title: Rogue Wave Spectra of the Kundu-Eckhaus Equation

abstract:
  In this paper we analyze the rogue wave spectra of the Kundu-Eckhaus equation
(KEE). We compare our findings with their nonlinear Schrodinger equation (NLSE)
analogs and show that the spectra of the individual rogue waves significantly
differ from their NLSE analogs. A remarkable difference is the one-sided
development of the triangular spectrum before the rogue wave becomes evident in
time. Also we show that increasing the skewness of the rogue wave results in
increased asymmetry in the triangular Fourier spectra. Additionally, the
triangular spectra of the rogue waves of the KEE begin to develop at earlier
stages of the their development compared to their NLSE analogs, especially for
larger skew angles. This feature may be used to enhance the early warning times
of the rogue waves. However we show that in a chaotic wavefield with many
spectral components the triangular spectra remains as the main attribute as a
universal feature of the typical wavefields produced through modulation
instability and characteristic features of the KEE's analytical rogue wave
spectra may be suppressed in a realistic chaotic wavefield.

categories: nlin.PS physics.ao-ph physics.flu-dyn physics.optics


title:
Magnetic Inhibition of Convection and the Fundamental Properties of
  Low-Mass Stars. III. A Consistent 10 Myr Age for the Upper Scorpius OB
  Association

abstract:
  When determining absolute ages of identifiably young stellar populations,
results strongly depend on which stars are studied. Cooler (K, M) stars
typically yield ages that are systematically younger than warmer (A, F, G)
stars by a factor of two. I explore the possibility that these age
discrepancies are the result of magnetic inhibition of convection in cool young
stars by using magnetic stellar evolution isochrones to determine the age of
the Upper Scorpius subgroup of the Scorpius-Centaurus OB Association. A median
age of 10 Myr consistent across spectral types A through M is found, except for
a subset of F-type stars that appear significantly older. Agreement is shown
for ages derived from the Hertzsprung-Russell diagram and from the empirical
mass-radius relationship defined by eclipsing multiple-star systems. Surface
magnetic field strengths required to produce agreement are of order 2.5 kG and
are predicted from a priori estimates of equipartition values. A region in the
HR diagram is identified that plausibly connects stars whose structures are
weakly influenced by the presence of magnetic fields with those whose
structures are strongly influenced by magnetic fields. The models suggest this
region is characterized by stars with rapidly thinning outer convective
envelopes where the radiative core mass is greater than 75% of the total
stellar mass. Furthermore, depletion of lithium predicted from magnetic models
appears in better agreement with observed lithium equivalent widths than
predictions from non-magnetic models. These results suggest that magnetic
inhibition of convection plays an important role in the early evolution of
low-mass stars and that it may be responsible for noted age discrepancies in
young stellar populations.


title: On Dynamic Deviation Measures and Continuous-Time Portfolio Optimisation

abstract:
  In this paper we propose the notion of dynamic deviation measure, as a
dynamic time-consistent extension of the (static) notion of deviation measure.
To achieve time-consistency we require that a dynamic deviation measures
satisfies a generalised conditional variance formula. We show that, under a
domination condition, dynamic deviation measures are characterised as the
solutions to a certain class of backward SDEs. We establish for any dynamic
deviation measure an integral representation, and derive a dual
characterisation result in terms of additively $m$-stable dual sets. Using this
notion of dynamic deviation measure we formulate a dynamic mean-deviation
portfolio optimisation problem in a jump-diffusion setting and identify a
subgame-perfect Nash equilibrium strategy that is linear as function of wealth
by deriving and solving an associated extended HJB equation.


title: Disformal transformations on the CMB

abstract:
  In this work we study the role of disformal transformation on cosmological
backgrounds and its relation to the speed of sound for tensor modes. A speed
different from one for tensor modes can arise in several contexts, such as
Galileons theories or massive gravity, nevertheless the speed is very
constrained to be one by observations of gravitational wave emission. It has
been shown that in inflation a disformal trans- formation allows to set the
speed for tensor modes to one without making changes to the curvature power
spectrum. Here we show that this invariance does not hold when considering the
CMB anisotropy power spectrum. It turns out that the after doing the
transformation there is an imprint on the acoustic peaks and the diffusion
damping. This has interesting consequences; here we explore quartic galileon
theories which allow a modified speed for tensor modes. For these theories the
transformation can be used to constraint the parameter space in different
regimes.


title:
A Study of Cosmic Expansion Generated by Non-conservation of Matter in
  the Framework of Brans-Dicke Theory

abstract:
  The present study, on the expansion of universe, is based on an assumption
regarding the possibility of inter-conversion between matter and dark energy,
through some interaction of matter with the scalar field in the framework of
Brans-Dicke theory. The field equations for a spatially flat space-time have
been solved using an empirical dependence of scalar field parameter upon the
scale factor. To represent the behaviour regarding the non-conservation of
matter, a function, expressed in terms of the Hubble parameter, has been
empirically incorporated into the field equations. Their solution shows that,
this function, whose value is proportional to the matter content of the
universe, decreases monotonically with time. This matter-field interaction
generates late time acceleration, causing the deceleration parameter to change
its sign from positive to negative. Time dependence of the proportion of dark
energy component of the universe has been determined and shown graphically.
Time variation of gravitational constant and the Brans-Dicke dimensionless
parameter has been analyzed in the present study. The rate of generation of
dark energy from matter has been found to affect the time variations of
deceleration parameter and gravitational constant.


title: Finding Finite Models in Multi-Sorted First Order Logic

abstract:
  This work extends the existing MACE-style finite model finding approach to
multi-sorted first order logic. This existing approach iteratively assumes
increasing domain sizes and encodes the related ground problem as a SAT
problem. When moving to the multi-sorted setting each sort may have a different
domain size, leading to an explosion in the search space. This paper focusses
on methods to tame that search space. The key approach adds additional
information to the SAT encoding to suggest which domains should be grown.
Evaluation of an implementation of techniques in the Vampire theorem prover
shows that they dramatically reduce the search space and that this is an
effective approach to find finite models in multi-sorted first order logic.


title: Reducing DRAM Latency at Low Cost by Exploiting Heterogeneity

abstract:
  In modern systems, DRAM-based main memory is significantly slower than the
processor. Consequently, processors spend a long time waiting to access data
from main memory, making the long main memory access latency one of the most
critical bottlenecks to achieving high system performance. Unfortunately, the
latency of DRAM has remained almost constant in the past decade. This is mainly
because DRAM has been optimized for cost-per-bit, rather than access latency.
As a result, DRAM latency is not reducing with technology scaling, and
continues to be an important performance bottleneck in modern and future
systems.
  This dissertation seeks to achieve low latency DRAM-based memory systems at
low cost in three major directions. First, based on the observation that long
bitlines in DRAM are one of the dominant sources of DRAM latency, we propose a
new DRAM architecture, Tiered-Latency DRAM (TL-DRAM), which divides the long
bitline into two shorter segments using an isolation transistor, allowing one
segment to be accessed with reduced latency. Second, we propose a fine-grained
DRAM latency reduction mechanism, Adaptive-Latency DRAM, which optimizes DRAM
latency for the common operating conditions for individual DRAM module. Third,
we propose a new technique, Architectural-Variation-Aware DRAM (AVA-DRAM),
which reduces DRAM latency at low cost, by profiling and identifying only the
inherently slower regions in DRAM to dynamically determine the lowest latency
DRAM can operate at without causing failures.
  This dissertation provides a detailed analysis of DRAM latency by using both
circuit-level simulation with a detailed DRAM model and FPGA-based profiling of
real DRAM modules. Our latency analysis shows that our low latency DRAM
mechanisms enable significant latency reductions, leading to large improvement
in both system performance and energy efficiency.


title: Three-Dimensional Extended Bargmann Supergravity

abstract:
  We show that three-dimensional General Relativity, augmented with two vector
fields, allows for a non-relativistic limit, different from the standard limit
leading to Newtonian gravity, that results into a well-defined action which is
of the Chern-Simons type. We show that this three-dimensional `Extended
Bargmann Gravity', after coupling to matter, leads to equations of motion
allowing a wider class of background geometries than the ones that one
encounters in Newtonian gravity. We give the supersymmetric generalization of
these results and point out an important application in the context of
calculating partition functions of non-relativistic field theories using
localization techniques.


title: Relativistic two-body calculation of $b\bar{b}$-mesons radiative decays

abstract:
  This paper is a prosecution of a previous work where we presented a unified
two-fermion covariant scheme which produced very precise results for the masses
of light and heavy mesons. We extend the analysis to some radiative decays of
mesons $\Upsilon,\,\chi_{b2}\,,h_b\,,\chi_{b1}\,,\chi_{b0}\,,\eta_b\,$ and we
calculate their branching ratios and their widths. For most of them we can make
a comparison with experimental data finding a good agreement.For the decays for
which data are not available we compare ours with other recent theoretical
previsions.


title: A splitting approach for the magnetic Schr\"odinger equation

abstract:
  The Schr\"odinger equation in the presence of an external electromagnetic
field is an important problem in computational quantum mechanics. It also
provides a nice example of a differential equation whose flow can be split with
benefit into three parts. After presenting a splitting approach for three
operators with two of them being unbounded, we exemplarily prove first-order
convergence of Lie splitting in this framework. The result is then applied to
the magnetic Schr\"odinger equation, which is split into its potential, kinetic
and advective parts. The latter requires special treatment in order not to lose
the conservation properties of the scheme. We discuss several options.
Numerical examples in one, two and three space dimensions show that the method
of characteristics coupled with a nonequispaced fast Fourier transform (NFFT)
provides a fast and reliable technique for achieving mass conservation at the
discrete level.


title: Estimating psychopathological networks: be careful what you wish for

abstract:
  Network models, in which psychopathological disorders are conceptualized as a
complex interplay of psychological and biological components, have become
increasingly popular in the recent psychopathological literature. These network
models often contain significant numbers of unknown parameters, yet the sample
sizes available in psychological research are limited. As such, general
assumptions about the true network are introduced to reduce the number of free
parameters. Incorporating these assumptions, however, means that the resulting
network will lead to reflect the particular structure assumed by the estimation
method---a crucial and often ignored aspect of psychopathological networks. For
example, observing a sparse structure and simultaneously assuming a sparse
structure does not imply that the true model is, in fact, sparse. To illustrate
this point, we discuss recent literature and show the effect of the assumption
of sparsity in three simulation studies.


title:
The Continuing Story of SN IIb 2013df: New Optical and IR Observations
  and Analysis

abstract:
  SN 2013df is a nearby Type IIb supernova that seems to be the spectroscopic
twin of the well-known SN 1993J. Previous studies revealed many, but not all
interesting properties of this event. Our goal was to add new understanding of
both the early and late-time phases of SN 2013df. Our spectral analysis is
based on 6 optical spectra obtained with the 9.2m Hobby-Eberly Telescope during
the first month after explosion, complemented by a near-infrared spectrum. We
applied the SYNAPPS spectral synthesis code to constrain the chemical
composition and physical properties of the ejecta. A principal result is the
identification of "high-velocity" He I lines in the early spectra of SN 2013df,
manifest as the blue component of the double-troughed profile at ~5650 A. This
finding, together with the lack of clear separation of H and He lines in
velocity space, indicates that both H and He features form at the outer
envelope during the early phases. We also obtained ground-based BVRI and
g'r'i'z' photometric data up to +45 days and unfiltered measurements with the
ROTSE-IIIb telescope up to +168 days. From the modelling of the early-time
quasi-bolometric light curve, we find $M_{ej} \sim 3.2-4.6 M_{\odot}$ and
$E_{kin} \sim 2.6-2.8 \times 10^{51}$ erg for the initial ejecta mass and the
initial kinetic energy, respectively, which agree well with the values derived
from the separate modelling of the light-curve tail. Late-time mid-infrared
excess indicates circumstellar interaction starting ~1 year after explosion, in
accordance with previously published optical, X-ray, and radio data.


title: Convergence of Functions and their Moreau Envelopes on Hadamard Spaces

abstract:
  A well known result of H. Attouch states that the Mosco convergence of a
sequence of proper convex lower semicontinuous functions defined on a Hilbert
space is equivalent to the pointwise convergence of the associated Moreau
envelopes. In the present paper we generalize this result to Hadamard spaces.
More precisely, while it has already been known that the Mosco convergence of a
sequence of convex lower semicontinuous functions on a Hadamard space implies
the pointwise convergence of the corresponding Moreau envelopes, the converse
implication was an open question. We now fill this gap.
  Our result has several consequences. It implies, for instance, the
equivalence of the Mosco and Frol\'ik-Wijsman convergences of convex sets. As
another application, we show that there exists a complete metric on the cone of
proper convex lower semicontinuous functions on a separable Hadamard space such
that a sequence of functions converges in this metric if and only if it
converges in the sense of Mosco.


title:
From geodesic flow on a surface of negative curvature to electronic
  generator of robust chaos

abstract:
  Departing from the geodesic flow on a surface of negative curvature as a
classic example of the hyperbolic chaotic dynamics, we propose an electronic
circuit operating as a generator of rough chaos. Circuit simulation in NI
Multisim software package and numerical integration of the model equations are
provided. Results of computations (phase trajectories, time dependences of
variables, Lyapunov exponents and Fourier spectra) show good correspondence
between the chaotic dynamics on the attractor of the proposed system and of the
Anosov dynamics for the original geodesic flow.


title: Higher-dimensional Contou-Carr\`ere symbol and continuous automorphisms

abstract:
  We prove that the higher-dimensional Contou-Carr\`ere symbol is invariant
under continuous automorphisms of algebras of iterated Laurent series over a
ring. Applying this property, we obtain a new explicit formula for the
higher-dimensional Contou-Carr\`ere symbol. Unlike previously known formulas,
this formula is given over an arbitrary ring, not necessarily a $\mathbb
Q$-algebra, and does not involve algebraic $K$-theory.


title:
Investigation of the Newly Proposed Carrier-Envelope-Phase Stable
  Attosecond Pulse Source

abstract:
  Practical aspects of the robust method we recently proposed for producing
few-cycle attosecond pulses with arbitrary waveform in the extreme ultraviolet
spectral range are studied numerically. It is based on the undulator radiation
of relativistic ultrathin electron layers produced by inverse free-electron
laser process. Optimal conditions for nanobunching are given; attosecond pulse
energy and waveform, and their stability are studied. For K=0.8 undulator
parameter, carrier-envelope-phase stable pulses with >45 nJ energy and 80 as
duration at 20 nm, and >250 nJ energy and 240 as duration at 60 nm are
predicted with 31 mrad and 13 mrad phase stability, respectively.


title: Helium-4 Glass Phase: a Model for Liquid Elements

abstract:
  The specific heat of liquid helium confined under pressure in nanoporous
material and the formation, in these conditions, of a glass phase accompanied
by latent heat are known. These properties are in good agreement with a recent
model predicting, in liquid elements, the formation of ultrastable glass having
universal thermodynamic properties. The third law of thermodynamics involves
that the specific heat decreases at low temperatures and consequently the
effective transition temperature of the glass increases up to the temperature
where the frozen enthalpy becomes equal to the predicted value. The glass
residual entropy is about 23.6% of the melting entropy.


title: About the distance between random walkers on some graphs

abstract:
  We consider two or more simple symmetric walks on some graphs, e.g. the real
line, the plane or the two dimensional comb lattice, and investigate the
properties of the distance among the walkers.


title: Signed graphs with two negative edges

abstract:
  The presented paper studies the flow number $F(G,\sigma)$ of flow-admissible
signed graphs $(G,\sigma)$ with two negative edges. We restrict our study to
cubic graphs, because for each non-cubic signed graph $(G,\sigma)$ there is a
set ${\cal G}(G,\sigma)$ of cubic graphs such that $F(G, \sigma) \leq \min
\{F(H,\sigma_H) : (H,\sigma_H) \in {\cal G}(G)\}$. We prove that $F(G,\sigma)
\leq 6$ if $(G,\sigma)$ contains a bridge and $F(G,\sigma) \leq 7$ in general.
We prove better bounds, if there is an element $(H,\sigma_H)$ of ${\cal
G}(G,\sigma)$ which satisfies some additional conditions. In particular, if $H$
is bipartite, then $F(G,\sigma) \leq 4$ and the bound is tight. If $H$ is
3-edge-colorable or critical or if it has a sufficient cyclic
edge-connectivity, then $F(G,\sigma) \leq 6$. Furthermore, if Tutte's 5-Flow
Conjecture is true, then $(G,\sigma)$ admits a nowhere-zero 6-flow endowed with
some strong properties.


title:
Non-Relativistic Chern-Simons Theories and Three-Dimensional
  Horava-Lifshitz Gravity

abstract:
  We show that certain three-dimensional Horava-Lifshitz gravity theories can
be written as Chern-Simons gauge theories on various non-relativistic algebras.
The algebras are specific extensions of the Bargmann, Newton-Hooke and
Schroedinger algebra each of which has the Galilean algebra as a subalgebra. To
show this we employ the fact that Horava-Lifshitz gravity corresponds to
dynamical Newton-Cartan geometry. In particular, the extended Bargmann
(Newton-Hooke) Chern-Simons theory corresponds to projectable Horava-Lifshitz
gravity with a local U(1) gauge symmetry without (with) a cosmological
constant. Moreover we identify an extended Schroedinger algebra containing 3
extra generators that are central with respect to the subalgebra of Galilean
boosts, momenta and rotations, for which the Chern-Simons theory gives rise to
a novel version of non-projectable conformal Horava-Lifshitz gravity that we
refer to as Schroedinger gravity. This theory has a z=2 Lifshitz geometry as a
vacuum solution and thus provides a new framework to study Lifshitz holography.


title: Selecting the Selection

abstract:
  Modern saturation-based Automated Theorem Provers typically implement the
superposition calculus for reasoning about first-order logic with or without
equality. Practical implementations of this calculus use a variety of literal
selections and term orderings to tame the growth of the search space and help
steer proof search. This paper introduces the notion of lookahead selection
that estimates (looks ahead) the effect on the search space of selecting a
literal. There is also a case made for the use of incomplete selection
functions that attempt to restrict the search space instead of satisfying some
completeness criteria. Experimental evaluation in the \Vampire\ theorem prover
shows that both lookahead selection and incomplete selection significantly
contribute to solving hard problems unsolvable by other methods.


title: On the near horizon rotating black hole geometries with NUT charges

abstract:
  The near horizon geometries are usually constructed by implementing a
specific limit to a given extreme black hole configuration. Their salient
feature is that the isometry group includes the conformal subgroup SO(2,1). In
this work, we turn the logic around and use the conformal invariants for
constructing Ricci-flat metrics in d=4 and d=5 where the vacuum Einstein
equations reduce to a coupled set of ordinary differential equations. In four
dimensions the analysis can be carried out in full generality and the resulting
metric describes the d=4 near horizon Kerr-NUT black hole. In five dimensions
we choose a specific ansatz whose structure is similar to the d=5 near horizon
Myers-Perry black hole. A Ricci-flat metric involving five arbitrary parameters
is constructed. A particular member of this family, which is characterized by
three parameters, seems to be a natural candidate to describe the d=5 near
horizon Myers-Perry black hole with a NUT charge.


title:
A numerical method to compute derivatives of functions of large complex
  matrices and its application to the overlap Dirac operator at finite chemical
  potential

abstract:
  We present a method for the numerical calculation of derivatives of functions
of general complex matrices. The method can be used in combination with any
algorithm that evaluates or approximates the desired matrix function, in
particular with implicit Krylov-Ritz-type approximations. An important use case
for the method is the evaluation of the overlap Dirac operator in lattice
Quantum Chromodynamics (QCD) at finite chemical potential, which requires the
application of the sign function of a non-Hermitian matrix to some source
vector. While the sign function of non-Hermitian matrices in practice cannot be
efficiently approximated with source-independent polynomials or rational
functions, sufficiently good approximating polynomials can still be constructed
for each particular source vector. Our method allows for an efficient
calculation of the derivatives of such implicit approximations with respect to
the gauge field or other external parameters, which is necessary for the
calculation of conserved lattice currents or the fermionic force in Hybrid
Monte-Carlo or Langevin simulations. We also give an explicit deflation
prescription for the case when one knows several eigenvalues and eigenvectors
of the matrix being the argument of the differentiated function. We test the
method for the two-sided Lanczos approximation of the finite-density overlap
Dirac operator on realistic $SU(3)$ gauge field configurations on lattices with
sizes as large as $14\times14^3$ and $6\times18^3$.


title: Lifting QBF Resolution Calculi to DQBF

abstract:
  We examine the existing Resolution systems for quantified Boolean formulas
(QBF) and answer the question which of these calculi can be lifted to the more
powerful Dependency QBFs (DQBF). An interesting picture emerges: While for QBF
we have the strict chain of proof systems Q-Resolution < IR-calc < IRM-calc,
the situation is quite different in DQBF. Q-Resolution and likewise universal
Resolution are too weak: they are not complete. IR-calc has the right strength:
it is sound and complete. IRM-calc is too strong: it is not sound any more, and
the same applies to long-distance Resolution. Conceptually, we use the relation
of DQBF to EPR and explain our new DQBF calculus based on IR-calc as a
subsystem of FO-Resolution.


title: New Bounds for Hypergeometric Creative Telescoping

abstract:
  Based on a modified version of Abramov-Petkov\v{s}ek reduction, a new
algorithm to compute minimal telescopers for bivariate hypergeometric terms was
developed last year. We investigate further in this paper and present a new
argument for the termination of this algorithm, which provides an independent
proof of the existence of telescopers and even enables us to derive lower as
well as upper bounds for the order of telescopers for hypergeometric terms.
Compared to the known bounds in the literature, our bounds are sometimes
better, and never worse than the known ones.


title:
Temperature Dependence Calibration and Correction of the DAMPE BGO
  Electromagnetic Calorimeter

abstract:
  A BGO electromagnetic calorimeter (ECAL) is built for the DArk Matter
Particle Explorer (DAMPE) mission. The effect of temperature on the BGO ECAL
was investigated with a thermal vacuum experiment. The light output of a BGO
crystal depends on temperature significantly. The temperature coefficient of
each BGO crystal bar has been calibrated, and a correction method is also
presented in this paper.


title: Electrooptical Properties of Rydberg Excitons

abstract:
  We show how to compute the electrooptical functions (absorption, reflection,
and transmission) when Rydberg Excitons appear, including the effect of the
coherence between the electron-hole pair and the electromagnetic field. With
the use of Real Density Matrix Approach numerical calculations applied for
Cu$_2$0 crystal are performed. We also examine in detail and explain the
dependence of the resonance displacement on the state number and applied
electric field strength. We report a good agreement with recently published
experimental data.


title:
Global classical solutions of the Vlasov-Fokker-Planck equation with
  local alignment forces

abstract:
  In this paper, we are concerned with the global well-posedness and
time-asymptotic decay of the Vlasov-Fokker-Planck equation with local alignment
forces. The equation can be formally derived from an agent-based model for
self-organized dynamics which is called Motsch-Tadmor model with noises. We
present the global existence and uniqueness of classical solutions to the
equation around the global Maxwellian in the whole space. For the large-time
behavior, we show the algebraic decay rate of solutions towards the equilibrium
under suitable assumptions on the initial data. We also remark that the rate of
convergence is exponential when the spatial domain is periodic. The main
methods used in this paper are the classical energy estimates combined with
hyperbolic-parabolic dissipation arguments.


title: Phase Separation and Dynamics of two-component Bose-Einstein condensates

abstract:
  The miscibility of two interacting quantum systems is an important testing
ground for the understanding of complex quantum systems. Two-component
Bose-Einstein condensates enable the investigation of this scenario in a
particularly well controlled setting. In a homogeneous system, the transition
between mixed and separated phases is fully characterised by a `miscibility
parameter', based on the ratio of intra- to inter-species interaction
strengths. Here we show, however, that this parameter is no longer the optimal
one for trapped gases, for which the location of the phase boundary depends
critically on atom numbers. We demonstrate how monitoring of damping rates and
frequencies of dipole oscillations enables the experimental mapping of the
phase diagram by numerical implementation of a fully self-consistent
finite-temperature kinetic theory for binary condensates. The change in damping
rate is explained in terms of surface oscillation in the immiscible regime, and
counterflow instability in the miscible regime, with collisions becoming only
important in the long time evolution.


title:
Using Cardy-Jacobsen and Yaffe-Svetitsky Conjectures to Solve the
  Cosmological Domain Wall and Dark Matter Overproduction Problems

abstract:
  In this paper I will combine and use two Cardy-Jacobsen and Yaffe-Svetitsky
conjectures \cite{c.1,c.2} to present a mechanism for a late-time inflation
during the electroweak symmetry breaking due to discrete $Z_3$ symmetry at
$\textit{O} (10)^2$ GeV and a psudo-inflation at $\textit{O}(10)^2$ MeV scale
in order to solve the cosmological domain wall problem as well as thermal and
non-thermal relics overproduction in the early universe. We will see that
Cardy-Jacobsen conjecture and Zel'dovic statement for cosmological domain wall
problem are incompatible. Also, in the psudo-inflation mechanism presented here
there would be a latent heat release and entropy injection without an
exponential expansion and reheating period.


title: Wide Aperture Vector magnet for neutron scattering studies

abstract:
  We propose an innovative design for a vector magnet compatible with neutron
scattering experiments. This would vastly expand the range of experimental
possibilities since applying a magnetic field and orienting the sample in
diffraction conditions will become completely independent. This Wide Aperture
VEctor magnet is a setup made of 16 coils, all with a vertical axis. The
vertical component of the field is produced by two pairs of coaxial coils
carrying opposite currents for an active shielding of the stray field, while
the horizontal components are generated by 3 sets of 4 coils each, two above
and two below the diffraction plane. This innovative geometry allows a very
wide aperture (220$\,^{\circ}$ horizontal, $\pm$ 10$\,^{\circ}$ vertical),
which is crucial for neutron diffraction and inelastic neutron scattering
experiments. Moreover, the homogeneity of the field is far better than in the
usual vertical coils, and the diameter of the sample bore is unusually large
(10 cm).
  The concept has been developed so as to be used as a sample environment on
every LLB instrument relevant for magnetism studies.


title:
The Manne et al. self-stabilizing 2/3-approximation matching algorithm
  is sub-exponential

abstract:
  Manne et al. designed the first algorithm computing a maximal matching that
is a 2/3 -approximation of the maximum matching in $O(^2n)$ moves. However, the
complexity tightness was not proved. In this paper, we exhibit a
sub-exponential execution of this matching algorithm.


title: Emergent Gravity from an Augmented Variational Principle

abstract:
  A direct and non-trivial link between Padmanabhan's entropy used in emergent
gravity and standard GR action is established. To do that, Augmented
Variational Principles (AVP) will be used. We shall discuss how this link
accounts for the details of the variation of Padmanabhan's action based on
gravitational entropy. It will also clarify the role of the background metric
and its non-dynamical role.


title: Sum-of-Squares approach to feedback control of laminar wake flows

abstract:
  A novel nonlinear feedback control design methodology for incompressible
fluid flows aiming at the optimisation of long-time averages of flow quantities
is presented. It applies to reduced-order finite-dimensional models of fluid
flows, expressed as a set of first-order nonlinear ordinary differential
equations with the right-hand side being a polynomial function in the state
variables and in the controls. The key idea, first discussed in Chernyshenko et
al. 2014, Philos. T. Roy. Soc. 372(2020), is that the difficulties of treating
and optimising long-time averages of a cost are relaxed by using the
upper/lower bounds of such averages as the objective function. In this setting,
control design reduces to finding a feedback controller that optimises the
bound, subject to a polynomial inequality constraint involving the cost
function, the nonlinear system, the controller itself and a tunable polynomial
function. A numerically tractable approach to the solution of such optimisation
problems, based on Sum-of-Squares techniques and semidefinite programming, is
proposed.
  To showcase the methodology, the mitigation of the fluctuation kinetic energy
in the unsteady wake behind a circular cylinder in the laminar regime at
Re=100, via controlled angular motions of the surface, is numerically
investigated. A compact reduced-order model that resolves the long-term
behaviour of the fluid flow and the effects of actuation, is derived using
Proper Orthogonal Decomposition and Galerkin projection. In a full-information
setting, feedback controllers are then designed to reduce the long-time average
of the kinetic energy associated with the limit cycle. These controllers are
then implemented in direct numerical simulations of the actuated flow. Control
performance, energy efficiency, and physical control mechanisms identified are
analysed. Key elements, implications and future work are discussed.


title:
Identification of Nonlinear Normal Modes of Engineering Structures under
  Broadband Forcing

abstract:
  The objective of the present paper is to develop a two-step methodology
integrating system identification and numerical continuation for the
experimental extraction of nonlinear normal modes (NNMs) under broadband
forcing. The first step processes acquired input and output data to derive an
experimental state-space model of the structure. The second step converts this
state-space model into a model in modal space from which NNMs are computed
using shooting and pseudo-arclength continuation. The method is demonstrated
using noisy synthetic data simulated on a cantilever beam with a
hardening-softening nonlinearity at its free end.


title: Convex Hedging in Incomplete Markets

abstract:
  In incomplete financial markets not every contingent claim can be replicated
by a self-financing strategy. The risk of the resulting shortfall can be
measured by convex risk measures, recently introduced by F\"ollmer, Schied
(2002). The dynamic optimization problem of finding a self-financing strategy
that minimizes the convex risk of the shortfall can be split into a static
optimization problem and a representation problem. It follows that the optimal
strategy consists in superhedging the modified claim $\widetilde{\varphi}H$,
where $H$ is the payoff of the claim and $\widetilde{\varphi}$ is the solution
of the static optimization problem, the optimal randomized test.
  In this paper, we will deduce necessary and sufficient optimality conditions
for the static problem using convex duality methods. The solution of the static
optimization problem turns out to be a randomized test with a typical
$0$-$1$-structure.


title:
On the Vulnerability of Digital Fingerprinting Systems to Finite
  Alphabet Collusion Attacks

abstract:
  This paper proposes a novel, non-linear collusion attack on digital
fingerprinting systems. The attack is proposed for fingerprinting systems with
finite alphabet but can be extended to continuous alphabet. We analyze the
error probability of the attack for some classes of proposed random and
deterministic schemes and obtain a bound on the number of colluders necessary
to correctly estimate the host signal. That is, it requires fewer number of
colluders to defeat the fingerprinting scheme. Our simulation results show that
our attack is more powerful in practice than predicted by the theoretical
bound.


title:
The discrete family symmetry as a possible solution to the flavour
  problem

abstract:
  In order to explain the fermions masses and mixing parameters appearing in
the lepton sector of the Standard Model, one proposes the extension of its
symmetry. A discrete, non-abelian subgroup of $U(3)$ is added to the gauge
group $SU(3)_{C}\times SU(2)_{L}\times U(1)_{Y}$ . Apart from that, one assumes
the existence of one extra Higgs doublet. This article focuses mainly on the
mathematical theorems and computational techniques which brought us to the
results.


title:
Damping of the Collective Amplitude Mode in Superconductors with Strong
  Electron-Phonon Coupling

abstract:
  We study the effect of strong electron-phonon interactions on the damping of
the Higgs amplitude mode in superconductors by means of non-equilibrium
dynamical mean-field simulations of the Holstein model. In contrast to the BCS
dynamics, we find that the damping of the Higgs mode strongly depends on the
temperature, becoming faster as the systen approaches the transition
temperature. The damping at low temperatures is well described by a power-law,
while near the transition temperature the damping shows exponential-like
behavior. We explain this crossover by a temperature-dependent quasiparticle
lifetime caused by the strong electron- phonon coupling, which smears the
superconducting gap edge and makes the relaxation of the Higgs mode into
quasiparticles more efficient at elevated temperatures. We also reveal that the
phonon dynamics can soften the Higgs mode, which results in a slower damping.


title:
A numerical estimate of the regularity of a family of Strange
  Non--Chaotic Attractors

abstract:
  We estimate numerically the regularities of a family of Strange Non--Chaotic
Attractors related with one of the models studied in C. Grebogy et al. (1984)
(see also G. Keller (1996)). To estimate these regularities we use wavelet
analysis in the spirit of R. de la Llave et al. (2002) together with some
ad-hoc techniques that we develop to overcome the theoretical difficulties that
arise in the application of the method to the particular family that we
consider. These difficulties are mainly due to the facts that we do not have an
explicit formula for the attractor and it is discontinuous almost everywhere
for some values of the parameters. Concretely we propose an algorithm based on
the Fast Wavelet Transform. Also a quality check of the wavelet coefficients
and regularity estimates is done.


title:
Finding Influential Users in Social Media Using Association Rule
  Learning

abstract:
  Influential users play an important role in online social networks since
users tend to have an impact on one other. Therefore, the proposed work
analyzes users and their behavior in order to identify influential users and
predict user participation. Normally, the success of a social media site is
dependent on the activity level of the participating users. For both online
social networking sites and individual users, it is of interest to find out if
a topic will be interesting or not. In this article, we propose association
learning to detect relationships between users. In order to verify the
findings, several experiments were executed based on social network analysis,
in which the most influential users identified from association rule learning
were compared to the results from Degree Centrality and Page Rank Centrality.
The results clearly indicate that it is possible to identify the most
influential users using association rule learning. In addition, the results
also indicate a lower execution time compared to state-of-the-art methods.


title: The algebro-geometric study of range maps

abstract:
  Localizing a radiant source is a widespread problem to many scientific and
technological research areas. E.g. localization based on range measurements
stays at the core of technologies like radar, sonar and wireless sensors
networks. In this manuscript we study in depth the model for source
localization based on range measurements obtained from the source signal, from
the point of view of algebraic geometry. In the case of three receivers, we
find unexpected connections between this problem and the geometry of Kummer's
and Cayley's surfaces. Our work gives new insights also on the localization
based on range differences.


title:
Monogamy relation of multi-qubit systems for squared Tsallis-\emph{q}
  entanglement

abstract:
  Tsallis-$q$ entanglement is a bipartite entanglement measure which is the
generalization of entanglement of formation for $q$ tending to 1. We first
expand the range of $q$ for the analytic formula of Tsallis-\emph{q}
entanglement. For $\frac{5-\sqrt{13}}{2} \leq \emph{q} \leq
\frac{5+\sqrt{13}}{2}$, we prove the monogamy relation in terms of the squared
Tsallis-$q$ entanglement for an arbitrary multi-qubit systems. It is shown that
the multipartite entanglement indicator based on squared Tsallis-$q$
entanglement still works well even when the indicator based on the squared
concurrence loses its efficacy. We also show that the $\mu$-th power of
Tsallis-\emph{q} entanglement satisfies the monogamy or polygamy inequalities
for any three-qubit state.


title:
Entropy geometric construction of a pure substance with normal,
  superfluid and supersolid phases

abstract:
  Using the laws of thermodynamics together with empirical data, we present a
qualitative geometric construction of the fundamental relation of a pure
substance $S = S(E,N,V)$, with $S$ entropy, $E$ energy, $N$ number of particles
and $V$ volume. We analyze two very general type of substances, a "normal" and
a "quantum" one, the main difference between them being that the latter
presents superfluid phases. It is found that the constant entropy level curves
are completely different in both cases, in the normal substances being obtuse
while acute in quantum ones. A concomitant signature of the previous result is
that the chemical potential can be both positive and negative in quantum
substances, but only negative in normal ones. Our results suggest the existence
of a region in the quantum substances that may be identified as a supersolid
phase. We also make emphasis on the relevance of the present study within the
context of superfluidity in ultracold gases.


title: UBL: an R package for Utility-based Learning

abstract:
  This document describes the R package UBL that allows the use of several
methods for handling utility-based learning problems. Classification and
regression problems that assume non-uniform costs and/or benefits pose serious
challenges to predictive analytic tasks. In the context of meteorology,
finance, medicine, ecology, among many other, specific domain information
concerning the preference bias of the users must be taken into account to
enhance the models predictive performance. To deal with this problem, a large
number of techniques was proposed by the research community for both
classification and regression tasks. The main goal of UBL package is to
facilitate the utility-based predictive analytic task by providing a set of
methods to deal with this type of problems in the R environment. It is a
versatile tool that provides mechanisms to handle both regression and
classification (binary and multiclass) tasks. Moreover, UBL package allows the
user to specify his domain preferences, but it also provides some automatic
methods that try to infer those preference bias from the domain, considering
some common known settings.


title: Concurrent Data Structures Linked in Time

abstract:
  Arguments about correctness of a concurrent data structure are typically
carried out by using the notion of linearizability and specifying the
linearization points of the data structure's procedures. Such arguments are
often cumbersome as the linearization points' position in time can be dynamic
(depend on the interference, run-time values and events from the past, or even
future), non-local (appear in procedures other than the one considered), and
whose position in the execution trace may only be determined after the
considered procedure has already terminated.
  In this paper we propose a new method, based on a separation-style logic, for
reasoning about concurrent objects with such linearization points. We embrace
the dynamic nature of linearization points, and encode it as part of the data
structure's auxiliary state, so that it can be dynamically modified in place by
auxiliary code, as needed when some appropriate run-time event occurs. We name
the idea linking-in-time, because it reduces temporal reasoning to spatial
reasoning. For example, modifying a temporal position of a linearization point
can be modeled similarly to a pointer update in separation logic. Furthermore,
the auxiliary state provides a convenient way to concisely express the
properties essential for reasoning about clients of such concurrent objects. We
illustrate the method by verifying (mechanically in Coq) an intricate optimal
snapshot algorithm due to Jayanti, as well as some clients.


title:
Intermittency and Velocity Fluctuations in Hopper Flows Prone to
  Clogging

abstract:
  We experimentally study the dynamics of granular media in a discharging
hopper. In such flows, there often appears to be a critical outlet size $D_c$
such that the flow never clogs for $D > D_c$. We report on the time-averaged
velocity distributions, as well as temporal intermittency in the
ensemble-averaged velocity of grains in a viewing window, for both $D < D_c$
and $D > D_c$, near and far from the outlet. We characterize the velocity
distributions by the standard deviation and the skewness of the distribution of
vertical velocities. We propose a measure for intermittency based on the
two-sample Kolmogorov-Smirnov $D_{KS}$-statistic for the velocity distributions
as a function of time. We find that there is no discontinuity or kink in these
various measures as a function of hole size. This result supports the
proposition that there is no well-defined $D_c$ and that clogging is always
possible. Furthermore, the intermittency time scale of the flow is set by the
speed of the grains at the hopper exit. This latter finding is consistent with
a model of clogging as the independent sampling for stable configurations at
the exit with a rate set by the exiting grain speed [Thomas and Durian, Phys.
Rev. Lett. (2015)].


title: The QCD Running Coupling

abstract:
  We review the present knowledge for $\alpha_s$, the fundamental coupling
underlying the interactions of quarks and gluons in QCD. The dependence of
$\alpha_s(Q^2)$ on momentum transfer $Q$ encodes the underlying dynamics of
hadron physics -from color confinement in the infrared domain to asymptotic
freedom at short distances. We review constraints on $\alpha_s(Q^2)$ at high
$Q^2$, as predicted by perturbative QCD, and its analytic behavior at small
$Q^2$, based on models of nonperturbative dynamics. In the introductory part of
this review, we explain the phenomenological meaning of $\alpha_s$, the reason
for its running, and the challenges facing a complete understanding of its
analytic behavior in the infrared domain. In the second, more technical, part
of the review, we discuss the behavior of $\alpha_s(Q^2)$ in the high $Q^2$
domain of QCD. We review how $\alpha_s$ is defined, including its
renormalization scheme dependence, the definition of its renormalization scale,
the utility of effective charges, as well as Commensurate Scale Relations which
connect the various definitions of $\alpha_s$ without renormalization-scale
ambiguity. We also report recent measurements and theoretical analyses which
have led to precise QCD predictions at high energy. In the last part of the
review, we discuss the challenge of understanding the analytic behavior
$\alpha_s(Q^2)$ in the infrared domain. We also review important methods for
computing $\alpha_s$, including lattice QCD, the Schwinger-Dyson equations, the
Gribov-Zwanziger analysis and light-front holographic QCD. After describing
these approaches and enumerating their conflicting predictions, we discuss the
origin of these discrepancies and how to remedy them. Our aim is not only to
review the advances in this difficult area, but also to suggest what could be
an optimal definition of $\alpha_s$ in order to bring better unity to the
subject.


title:
Open problems concerning the Holder continuity of the direction of
  vorticity for the Navier-Stokes equations

abstract:
  In these notes we consider solutions u to the evolution three dimensional
Navier-Stokes equations in the whole space. Set w= curl u, the vorticity of u.
Our study concerns mainly the relation between Holdercontinuity assumptions on
the direction of the vorticity and induced space-time integrability regularity
results for w. We discuss some related open problems, consistent with our
calculations. We hope that our approach should help readers interesting in
carrying on the investigation.


title: Nijenhuis forms on Lie-infinity algebras associated to Lie algebroids

abstract:
  Introducing Nijenhuis forms on Lie-infinity algebras gives a general frame to
understand deformations of the latter. We give here a Nijenhuis interpretation
of a deformation of an arbitrary Lie algebroid into a Lie-infinity algebra.
Then we show that Nijenhuis forms on Lie-infinity algebras also give a short
and efficient manner to understand Poisson-Nijenhuis structures and, more
generally, the so-called exact Poisson quasi-Nijenhuis structures with
background.


title:
Scalable Bayesian nonparametric measures for exploring pairwise
  dependence via Dirichlet Process Mixtures

abstract:
  In this article we propose novel Bayesian nonparametric methods using
Dirichlet Process Mixture (DPM) models for detecting pairwise dependence
between random variables while accounting for uncertainty in the form of the
underlying distributions. A key criteria is that the procedures should scale to
large data sets. In this regard we find that the formal calculation of the
Bayes factor for a dependent-vs.-independent DPM joint probability measure is
not feasible computationally. To address this we present Bayesian diagnostic
measures for characterising evidence against a "null model" of pairwise
independence. In simulation studies, as well as for a real data analysis, we
show that our approach provides a useful tool for the exploratory nonparametric
Bayesian analysis of large multivariate data sets.


title: Balanced model order reduction for systems depending on a parameter

abstract:
  We provide an analytical framework for balanced realization model order
reduction of linear control systems which depend on an unknown parameter.
Besides recovering known results for the first order corrections, we obtain
explicit novel expressions for the form of second order corrections for
singular values and singular vectors. The final result of our procedure is an
order reduced model which incorporates the uncertain parameter. We apply our
algorithm to the model order reduction of a linear system of masses and springs
with parameter dependent coefficients.


title: Consistent Map-based 3D Localization on Mobile Devices

abstract:
  The objective of this paper is to provide consistent, real-time 3D
localization capabilities to mobile devices navigating within previously mapped
areas. To this end, we introduce the Cholesky-Schmidt-Kalman filter (C-SKF),
which explicitly considers the uncertainty of the prior map, by employing the
sparse Cholesky factor of the map's Hessian, instead of its dense
covariance--as is the case for the Schmidt-Kalman filter (SKF). By doing so,
the C-SKF has memory requirements typically linear in the size of the map, as
opposed to quadratic for storing the map's covariance. Moreover, and in order
to bound the processing needs of the C-SKF (between linear and quadratic in the
size of the map), we introduce a relaxation of the C-SKF algorithm, the sC-SKF,
which operates on the Cholesky factors of independent sub-maps resulting from
dividing the trajectory and observations used for constructing the map into
overlapping segments. Lastly, we assess the processing and memory requirements
of the proposed C-SKF and sC-SKF algorithms, and compare their positioning
accuracy against other approximate map-based localization approaches that
employ measurement-noise-covariance inflation to compensate for the map's
uncertainty.


title: Detecting Violence in Video using Subclasses

abstract:
  This paper attacks the challenging problem of violence detection in videos.
Different from existing works focusing on combining multi-modal features, we go
one step further by adding and exploiting subclasses visually related to
violence. We enrich the MediaEval 2015 violence dataset by \emph{manually}
labeling violence videos with respect to the subclasses. Such fine-grained
annotations not only help understand what have impeded previous efforts on
learning to fuse the multi-modal features, but also enhance the generalization
ability of the learned fusion to novel test data. The new subclass based
solution, with AP of 0.303 and P100 of 0.55 on the MediaEval 2015 test set,
outperforms several state-of-the-art alternatives. Notice that our solution
does not require fine-grained annotations on the test set, so it can be
directly applied on novel and fully unlabeled videos. Interestingly, our study
shows that motion related features, though being essential part in previous
systems, are dispensable.


title:
Hot scalar radiation around a cosmic string setting bounds on the
  coupling parameter $\xi$

abstract:
  In this work, by investigating the low temperature behaviour of a scalar
field around a cosmic string, and assuming stable thermodynamic equilibrium, it
is shown that the coupling parameter of the field with curvature must be
restricted to a certain range of values whose bounds are determined by the
deficit angle of the associated conical geometry.


title:
Reconstruction of a conic-section surface from autocollimator-based
  deflectometric profilometry

abstract:
  We present a description of our method to process a set of
autocollimator-based deflectometer 1-dimensional line-scans taken over a large
optical surface and reconstruct them to a best-fit conic-section surface. The
challenge with our task is that each line-scan is in a different (unknown)
coordinate reference frame with respect to the other line-scans in the set.
This problem arises due to the limited angular measurement range of the
autocollimator used in the deflectometer and the need to measure over a greater
range; this results in the optic under measurement being rotated (in pitch and
roll) between each scan to bring the autocollimator back into measurement range
and therefore each scan is taken in a different coordinate frame. We describe
an approach using a 6N+2 dimension optimisation (where N is the number of scan
lines taken across the mirror) that uses a gradient-based non-linear least
squares fitting combined with a multi-start global search strategy to find the
best-fit surface. Careful formulation of the problem is required to reduce
numerical noise and allow the routine to converge on a solution of the required
accuracy.


title:
Hausdorff dimension of the scaling limit of loop-erased random walk in
  three dimensions

abstract:
  Let $M_{n}$ be the length (number of steps) of the loop-erasure of a simple
random walk up to the first exit from a ball of radius $n$ centered at its
starting point. It is shown in [18] that there exists $\beta \in (1,
\frac{5}{3}]$ such that $E (M_{n} )$ is of order $n^{\beta}$ in 3 dimensions.
In the present article, we show that the Hausdorff dimension of the scaling
limit of the loop-erased random walk in 3 dimensions is equal to $\beta$ almost
surely.


title:
Enhanced reaction kinetics and reactive mixing scale dynamics in mixing
  fronts under shear flow for arbitrary Damk\"ohler numbers

abstract:
  Mixing fronts, where fluids of different chemical compositions mix with each
other, are typically subjected to velocity gradients, ranging from the pore
scale to the catchment scale due to permeability variations and flow line
geometries. A common trait of these processes is that the mixing interface is
strained by shear. Depending on the P\'eclet number $Pe$, which represents the
ratio of the characteristic diffusion time to the characteristic advection
time, and the Damk\"ohler number $Da$, which represents the ratio of the
characteristic diffusion time to the characteristic reaction time, the local
reaction rates can be strongly impacted by the dynamics of the mixing
interface. This impact has been characterized mostly either in kinetics-limited
or in mixing-limited conditions, that is, for either very low or very high
$Da$. Here the coupling of shear flow and chemical reactivity is investigated
for arbitrary Damk\"ohler numbers, for a bimolecular reaction and an initial
interface with separated reactants. Approximate analytical expressions for the
global production rate and reactive mixing scale are derived based on a
reactive lamella approach that allows for a general coupling between stretching
enhanced mixing and chemical reactions. While for $Pe<Da$, reaction kinetics
and stretching effects are decoupled, a scenario which we name "weak
stretching", for $Pe>Da$, we uncover a "strong stretching" scenario where new
scaling laws emerge from the interplay between reaction kinetics, diffusion,
and stretching. The analytical results are validated against numerical
simulations. These findings shed light on the effect of flow heterogeneity on
the enhancement of chemical reaction and the creation of spatially localized
hotspots of reactivity for a broad range of systems ranging from kinetic
limited to mixing limited situations.