title:
Quantum Fisher Information as a Predictor of Decoherence in the
  Preparation of Spin-Cat States for Quantum Metrology

abstract:
  In its simplest form, decoherence occurs when a quantum state is entangled
with a second state, but the results of measurements made on the second state
are not accessible. As the second state has effectively "measured" the first,
in this paper we argue that the quantum Fisher information is the relevant
metric for predicting and quantifying this kind of decoherence. The quantum
Fisher information is usually used to determine an upper bound on how precisely
measurements on a state can be used to estimate a classical parameter, and as
such it is an important resource. Quantum enhanced metrology aims to create
non-classical states with large quantum Fisher information and utilise them in
precision measurements. In the process of doing this it is possible for states
to undergo decoherence, for instance atom-light interactions used to create
coherent superpositions of atomic states may result in atom-light entanglement.
Highly non-classical states, such as spin-cat states (Schr\"odinger cat states
constructed from superpositions of collective spins) are shown to be highly
susceptible to this kind of decoherence. We also investigate the required field
occupation of the second state, such that this decoherence is negligible.


title: Single-molecule enhanced spin-flip detection

abstract:
  We studied the spin-flip excitations of a double-decker nickelocene molecule
(Nc) adsorbed on Cu(100) by means of inelastic tunneling spectroscopy (IETS),
X-ray magnetic circular dichroism (XMCD) and density functional theory
calculations (DFT). The results show that the molecule preserves its magnetic
moment and magnetic anisotropy not only on Cu(100), but also in different
metallic environments including the tip apex. Taking advantage of the efficient
spin-flip excitation of this molecule, we show how such a molecular
functionalized tip boosts the inelastic signal of a surface supported Nc by
almost one order of magnitude thanks to a double spin-excitation process.


title: Relative derived dimensions for cotilting modules

abstract:
  For a Noetherian ring $R$ and a cotilting $R$-module $T$ of injective
dimension at least $1$, we prove that the derived dimension of $R$ with respect
to the category $\mathcal{X}_T$ is precisely the injective dimension of $T$ by
applying Auslander-Buchweitz theory and Ghost Lemma. In particular, when $R$ is
a commutative Noetherian local ring with a canonical module $\omega_R$ and
$\dim R\ge1$, the derived dimension of R with respect to the category of
maximal Cohen-Macaulay modules is precisely $\dim R$.


title: Proper holomorphic Legendrian curves in $SL_2(\mathbb{C})$

abstract:
  In this paper we prove that every open Riemann surface properly embeds in the
Special Linear group $SL_2(\mathbb{C})$ as a holomorphic Legendrian curve,
where $SL_2(\mathbb{C})$ is endowed with its standard contact structure.
  As a consequence, we derive the existence of proper, weakly complete, flat
fronts in the real hyperbolic space $\mathbb{H}^3$ with arbitrary complex
structure.


title:
A Survey on Temperley-Lieb-type quotients from the Yokonuma-Hecke
  algebras

abstract:
  In this survey we collect all results regarding the construction of the
Framization of the Temperley-Lieb algebra of type $A$ as a quotient algebra of
the Yokonuma-Hecke algebra of type $A$. More precisely, we present all three
possible quotient algebras the emerged during this construction and we discuss
their dimension, linear bases, representation theory and the necessary and
sufficient conditions for the unique Markov trace of the Yokonuma-Hecke algebra
to factor through to each one of them. Further, we present the link invariants
that are derived from each quotient algebra and we point out which quotient
algebra provides the most natural definition for a framization of the
Temperley-Lieb algebra. From the Framization of the Temperley-Lieb algebra we
obtain new one-variable invariants for oriented classical links that, when
compared to the Jones polynomial, they are not topologically equivalent since
they distinguish more pair of non isotopic oriented links. Finally, we discuss
the generalization of the newly obtained invariants to a new two-variable
invariant for oriented classical links that is stronger than the Jones
polynomial.


title:
An application of incomplete pairwise comparison matrices for ranking
  top tennis players

abstract:
  Pairwise comparison is an important tool in multi-attribute decision making.
Pairwise comparison matrices (PCM) have been applied for ranking criteria and
for scoring alternatives according to a given criterion. Our paper presents a
special application of incomplete PCMs: ranking of professional tennis players
based on their results against each other. The selected 25 players have been on
the top of the ATP rankings for a shorter or longer period in the last 40
years. Some of them have never met on the court. One of the aims of the paper
is to provide ranking of the selected players, however, the analysis of
incomplete pairwise comparison matrices is also in the focus. The eigenvector
method and the logarithmic least squares method were used to calculate weights
from incomplete PCMs. In our results the top three players of four decades were
Nadal, Federer and Sampras. Some questions have been raised on the properties
of incomplete PCMs and remains open for further investigation.


title: Comparison theorems in pseudo-Hermitian geometry and applications

abstract:
  In this paper, we study the theory of geodesics with respect to the
Tanaka-Webster connection in a pseudo-Hermitian manifold, aiming to generalize
some comparison results in Riemannian geometry to the case of pseudo-Hermitian
geometry. Some Hopf-Rinow type, Cartan-Hadamard type and Bonnet-Myers type
results are established.


title: Rapidly rotating red giants

abstract:
  Stellar oscillations give seismic information on the internal properties of
stars. Red giants are targets of interest since they present mixed modes, which
behave as pressure modes in the convective envelope and as gravity modes in the
radiative core. Mixed modes thus directly probe red giant cores, and allow in
particular the study of their mean core rotation. The high-quality data
obtained by CoRoT and Kepler satellites represent an unprecedented perspective
to obtain thousands of measurements of red giant core rotation, in order to
improve our understanding of stellar physics in deep stellar interiors. We
developed an automated method to obtain such core rotation measurements and
validated it for stars on the red giant branch. In this work, we particularly
focus on the specific application of this method to red giants having a rapid
core rotation. They show complex spectra where it is tricky to disentangle
rotational splittings from mixed-mode period spacings. We demonstrate that the
method based on the identification of mode crossings is precise and efficient.
The determination of the mean core rotation directly derives from the precise
measurement of the asymptotic period spacing {\Delta}{\Pi}1 and of the
frequency at which the crossing of the rotational components is observed.


title: Solving puzzles of GW150914 by primordial black holes

abstract:
  The black hole binary properties inferred from the LIGO gravitational wave
signal GW150914 posed several serious problems. The high masses and low
effective spin of black hole binary can be explained if they are primordial
(PBH) rather than the products of the stellar binary evolution. Such PBH
properties are postulated ad hoc but not derived from fundamental theory. We
show that the necessary features of PBHs naturally follow from the slightly
modified Affleck-Dine (AD) mechanism of baryogenesis. The log-normal
distribution of PBHs, predicted within the AD paradigm, is adjusted to provide
an abundant population of low-spin stellar mass black holes. The same
distribution gives a sufficient number of quickly growing seeds of supermassive
black holes observed at high redshifts and may comprise an appreciable fraction
of Dark Matter which does not contradict any existing observational limits.
Testable predictions of this scenario are discussed.


title: On Observables in a Dark Matter-Clustering Quintessence System

abstract:
  We consider a system where dark matter dynamics is enriched by the presence
of clustering quintessence in the approximation where the system is effectively
reduced to one degree of freedom. We study the corresponding observables up to
one-loop order and then point out similarities between the power spectrum of
the reduced system and the behaviour of non-equal time pure dark matter
correlators. We then focus on the one-loop total density power spectrum in the
IR limit as a diagnostic tool for consistency relations breaking. Unlike the
non-equal time case, the reduced system does still obey consistency relations;
we illustrate this by explicitly verifying the 1-loop IR cancellation. A more
general setup, obtained by relaxing the assumption of a vanishing sound speed,
is also analyzed. In this and similar scenarios the presence of additional
dynamics, typical of dark energy and modified gravity models, implies that one
may no longer gauge away the squeezed contribution of observables such as the
dark matter bispectrum. We show how these effects propagate all the way to
biased tracers.


title: Investigations of the $D$-multi-$\rho$ interactions

abstract:
  In the present work, which aims at searching for bound sates, the
interactions of the $D$-multi-$\rho$ systems are investigated by means of the
formalism of the fixed-center-approximation to Faddeev equations. Reproducing
the states of $f_2 (1270)$ and $D_1 (2420)$ dynamically in the two-body
$\rho\rho$ and $\rho D$ interactions, respectively, as the clusters of the
fixed center approximation, the state of $D(3000)^0$ is found as a molecule of
$D-f_2$ or $\rho-D_1$ structures in the three-body interactions, where we
determine its quantum number $J^P = 2^-$ and find another possible state of
$D_2 (3100)$ with isospin $I=3/2$. In our results, there are some other
predictions with uncertainties, a $D_3 (3160)$ state with $I(J^P) = \frac{1}{2}
(3^+)$ in the four-body interactions, a narrow $D_4 (3730)$ state with $I(J^P)
= \frac{1}{2} (4^-)$, a wide $D_4 (3410)$ state of $I(J^P) = \frac{1}{2}
(4^-)$, and another wide $D_4 (3770)$ state but with $I(J^P) = \frac{3}{2}
(4^-)$ in the five-body interactions, and a $D_5 (3570)$ state with $I(J^P) =
\frac{1}{2} (5^+)$ in the six-body interactions. Our results are consistent
with the findings of quark models.


title: A nonparametric HMM for genetic imputation and coalescent inference

abstract:
  Genetic sequence data are well described by hidden Markov models (HMMs) in
which latent states correspond to clusters of similar mutation patterns. Theory
from statistical genetics suggests that these HMMs are nonhomogeneous (their
transition probabilities vary along the chromosome) and have large support for
self transitions. We develop a new nonparametric model of genetic sequence
data, based on the hierarchical Dirichlet process, which supports these self
transitions and nonhomogeneity. Our model provides a parameterization of the
genetic process that is more parsimonious than other more general nonparametric
models which have previously been applied to population genetics. We provide
truncation-free MCMC inference for our model using a new auxiliary sampling
scheme for Bayesian nonparametric HMMs. In a series of experiments on male X
chromosome data from the Thousand Genomes Project and also on data simulated
from a population bottleneck we show the benefits of our model over the popular
finite model fastPHASE, which can itself be seen as a parametric truncation of
our model. We find that the number of HMM states found by our model is
correlated with the time to the most recent common ancestor in population
bottlenecks. This work demonstrates the flexibility of Bayesian nonparametrics
applied to large and complex genetic data.


title:
A multi-resolution model to capture both global fluctuations of an
  enzyme and molecular recognition in the ligand-binding site

abstract:
  In multi-resolution simulations, different system components are
simultaneously modelled at different levels of resolution, these being smoothly
coupled together. In the case of enzyme systems, computationally expensive
atomistic detail is needed in the active site to capture the chemistry of
substrate binding. Global properties of the rest of the protein also play an
essential role, determining the structure and fluctuations of the binding site;
however, these can be modelled on a coarser level. Similarly, in the most
computationally efficient scheme only the solvent hydrating the active site
requires atomistic detail. We present a methodology to couple atomistic and
coarse-grained protein models, while solvating the atomistic part of the
protein in atomistic water. This allows a free choice of which protein and
solvent degrees of freedom to include atomistically, without loss of accuracy
in the atomistic description. This multi-resolution methodology can
successfully model stable ligand binding, and we further confirm its validity
via an exploration of system properties relevant to enzymatic function. In
addition to a computational speedup, such an approach can allow the
identification of the essential degrees of freedom playing a role in a given
process, potentially yielding new insights into biomolecular function.


title:
Holographic R\'enyi entropy for two-dimensional $\mathcal{N}$=(2,2)
  superconformal field theory

abstract:
  We investigate the holographic R\'enyi entropy for two-dimensional $\mathcal
N=(2,2)$ superconformal field theory (SCFT), which is dual to $\mathcal N=2$
supergravity in AdS$_3$ background. In SCFT we have the stress tensor, current,
and their supersymmetric partners, and in supergravity we have the graviton,
vector field, and two gravitinos. We get the R\'enyi mutual information of two
short intervals on complex plane in expansion by the cross ratio $x$ to order
$x^4$, and R\'enyi entropy of one interval on torus in expansion by
$q=\exp(-2\pi\beta/L)$, with $\beta$ being the inverse temperature and $L$
being the spatial period, to order $q^2$. We calculate in both the supergravity
and SCFT sides, and find matches of the results.


title:
Limitations and Alternatives for the Evaluation of Large-scale Link
  Prediction

abstract:
  Link prediction, the problem of identifying missing links among a set of
inter-related data entities, is a popular field of research due to its
application to graph-like domains. Producing consistent evaluations of the
performance of the many link prediction algorithms being proposed can be
challenging due to variable graph properties, such as size and density. In this
paper we first discuss traditional data mining solutions which are applicable
to link prediction evaluation, arguing about their capacity for producing
faithful and useful evaluations. We also introduce an innovative modification
to a traditional evaluation methodology with the goal of adapting it to the
problem of evaluating link prediction algorithms when applied to large graphs,
by tackling the problem of class imbalance. We empirically evaluate the
proposed methodology and, building on these findings, make a case for its
importance on the evaluation of large-scale graph processing.


title:
A uniform asymptotic expansion for the incomplete gamma functions
  revisited

abstract:
  A new uniform asymptotic expansion for the incomplete gamma function
$\Gamma(a,z)$ valid for large values of $z$ was given by the author in {\it J.
Comput. Appl. Math.} {\bf 148} (2002) 323--339. This expansion contains a
complementary error function of an argument measuring transition across the
point $z=a$, with easily computable coefficients that do not involve a
removable singularity in the neighbourhood of this point. In this note we
correct a misprint in the listing of certain coefficients in this expansion and
discuss in more detail the situation corresponding to $\Gamma(a,a)$.


title: Inferring Coupling of Distributed Dynamical Systems via Transfer Entropy

abstract:
  In this work, we are interested in structure learning for a set of spatially
distributed dynamical systems, where individual subsystems are coupled via
latent variables and observed through a filter. We represent this model as a
directed acyclic graph (DAG) that characterises the unidirectional coupling
between subsystems. Standard approaches to structure learning are not
applicable in this framework due to the hidden variables, however we can
exploit the properties of certain dynamical systems to formulate exact methods
based on state space reconstruction. We approach the problem by using
reconstruction theorems to analytically derive a tractable expression for the
KL-divergence of a candidate DAG from the observed dataset. We show this
measure can be decomposed as a function of two information-theoretic measures,
transfer entropy and stochastic interaction. We then present two mathematically
robust scoring functions based on transfer entropy and statistical independence
tests. These results support the previously held conjecture that transfer
entropy can be used to infer effective connectivity in complex networks.


title:
On accelerants and their analogs, and on the characterization of the
  rectangular Weyl functions for Dirac systems with locally square-integrable
  potentials on a semi-axis

abstract:
  We characterize the set of rectangular Weyl matrix functions corresponding to
Dirac systems with locally square-integrable potentials on a semi-axis and
demonstrate a new way to recover the locally square-integrable potential from
the Weyl function. Important interconnections between our approach and
accelerants of convolution operators are discussed as well.


title: Spectroscopy of two dimensional N=2 Super Yang Mills theory

abstract:
  Albeit the standard model is the most successful model of particles physics,
it still has some theoretical shortcomings, for instance the hierarchy problem,
the absence of dark matter, etc. Supersymmetric extensions of the standard
model could be a possible solution to these problems. One of the building
blocks of these supersymmetric models are supersymmetric gauge theories. It is
expected that they exhibit interesting features like confinement, chiral
symmetry breaking, magnetic monopoles and the like. We present new results on
N=2 Super Yang Mills theory in two dimensions. The lattice action is derived by
a dimensional reduction of the N=1 Super Yang Mills theory in four dimensions.
By preserving the R symmetry of the four dimensional model we can exploit Ward
identities to fine tune our parameters of the model to obtain the chiral and
supersymmetric continuum limit. This allows us to calculate the mass spectrum
at the physical point and compare these results with effective field theories.


title: DFT modelling of the effect of strong magnetic field on Aniline molecule

abstract:
  Aniline is an organic compound with the stoichiometric expression
$C_{6}H_{5}NH_{2}$; consisting of a phenyl structure attached to an amino
group. It is colorless, but it slowly oxidizes and resinifies in air, giving a
red-brown tint to aged samples. Until now, there are only few researches on
Aniline considering low magnetic fields. In this work, we study Aniline
molecule under different high magnetic fields using density functional theory
methods including independent particle and interacting particle approaches. We
obtain charge density distrubitions, energy dispersions, dipol moments and
forces as functions of position and magnetic field. Our numerical results show
that magnetic field affects electron density of the considered molecule. As a
result, it is observed that there are strong fluctuations in energy dispersion.


title: Rational curves on smooth hypersurfaces of low degree

abstract:
  We study the family of rational curves on arbitrary smooth hypersurfaces of
low degree using tools from analytic number theory.


title: Unveiling multiple AGN activity in galaxy mergers

abstract:
  In this paper we present an overview of the MAGNA (Multiple AGN Activity)
project aiming at a comprehensive study of multiple supemassive black hole
systems. With the main goal to characterize the sources in merging systems at
different stages of evolution, we selected a sample of objects optically
classified as multiple systems on the basis of emission line diagnostics and
started a massive multiband observational campaign. Here we report on the
discovery of the exceptionally high AGN density compact group SDSS~J0959+1259.
A multiband study suggests that strong interactions are taking place among its
galaxies through tidal forces, therefore this system represents a case study
for physical mechanisms that trigger nuclear activity and star formation. We
also present a preliminary analysis of the multiple AGN system
SDSS~J1038+3921.}


title: Sensitivity Maps of the Hilbert-Schmidt Independence Criterion

abstract:
  Kernel dependence measures yield accurate estimates of nonlinear relations
between random variables, and they are also endorsed with solid theoretical
properties and convergence rates. Besides, the empirical estimates are easy to
compute in closed form just involving linear algebra operations. However, they
are hampered by two important problems: the high computational cost involved,
as two kernel matrices of the sample size have to be computed and stored, and
the interpretability of the measure, which remains hidden behind the implicit
feature map. We here address these two issues. We introduce the Sensitivity
Maps (SMs) for the Hilbert-Schmidt independence criterion (HSIC). Sensitivity
maps allow us to explicitly analyze and visualize the relative relevance of
both examples and features on the dependence measure. We also present the
randomized HSIC (RHSIC) and its corresponding sensitivity maps to cope with
large scale problems. We build upon the framework of random features and the
Bochner's theorem to approximate the involved kernels in the canonical HSIC.
The power of the RHSIC measure scales favourably with the number of samples,
and it approximates HSIC and the sensitivity maps efficiently. Convergence
bounds of both the measure and the sensitivity map are also provided. Our
proposal is illustrated in synthetic examples, and challenging real problems of
dependence estimation, feature selection, and causal inference from empirical
data.


title:
The Morrison-Kawamata Cone Conjecture and Abundance on Ricci flat
  manifolds

abstract:
  The aim of this survey paper is threefold: (a) to discuss the status of the
Morrison-Kawamata cone conjecture, (b) to report on recent developments towards
the Abundance Conjecture, and (c) to discuss the nef line bundle version of the
Abundance Conjecture on $K$-trivial varieties.


title:
The Land Surface Temperature Synergistic Processor in BEAM: A Prototype
  towards Sentinel-3

abstract:
  Land Surface Temperature (LST) is one of the key parameters in the physics of
land-surface processes on regional and global scales, combining the results of
all surface-atmosphere interactions and energy fluxes between the surface and
the atmosphere. With the advent of the European Space Agency (ESA) Sentinel 3
(S3) satellite, accurate LST retrieval methodologies are being developed by
exploiting the synergy between the Ocean and Land Colour Instrument (OLCI) and
the Sea and Land Surface Temperature Radiometer (SLSTR). In this paper we
explain the implementation in the Basic ENVISAT Toolbox for (A)ATSR and MERIS
(BEAM) and the use of one LST algorithm developed in the framework of the
Synergistic Use of The Sentinel Missions For Estimating And Monitoring Land
Surface Temperature (SEN4LST) project. The LST algorithm is based on the
split-window technique with an explicit dependence on the surface emissivity.
Performance of the methodology is assessed by using MEdium Resolution Imaging
Spectrometer/Advanced Along-Track Scanning Radiometer (MERIS/AATSR) pairs,
instruments with similar characteristics than OLCI/ SLSTR, respectively. The
LST retrievals were properly validated against in situ data measured along one
year (2011) in three test sites, and inter-compared to the standard AATSR
level-2 product with satisfactory results. The algorithm is implemented in BEAM
using as a basis the MERIS/AATSR Synergy Toolbox. Specific details about the
processor validation can be found in the validation report of the SEN4LST
project.


title: Improving incremental recommenders with online bagging

abstract:
  Online recommender systems often deal with continuous, potentially fast and
unbounded flows of data. Ensemble methods for recommender systems have been
used in the past in batch algorithms, however they have never been studied with
incremental algorithms that learn from data streams. We evaluate online bagging
with an incremental matrix factorization algorithm for top-N recommendation
with positive-only -- binary -- ratings. Our results show that online bagging
is able to improve accuracy up to 35% over the baseline, with small
computational overhead.


title:
Online Algorithm for Demand Response with Inelastic Demands and Apparent
  Power Constraint

abstract:
  A classical problem in power systems is to allocate in-coming (elastic or
inelastic) demands without violating the operating constraints of electric
networks in an online fashion. Although online decision problems have been
well-studied in the literature, a unique challenge arising in power systems is
the presence of non-linear constraints, a departure from the traditional
settings. A particular example is the capacity constraint of apparent power,
which gives rise to a quadratic constraint, rather than typical linear
constraints. In this paper, we present a competitive randomized online
algorithm for deciding whether a sequence of inelastic demands can be allocated
for the requested intervals, subject to the total satisfiable apparent power
within a time-varying capacity constraint. We also consider an alternative
setting with nodal voltage constraint, using a variant of the online algorithm.
Finally, simulation studies are provided to evaluate the algorithms
empirically.


title:
Synchrotron radiation from a curved plasma channel laser wakefield
  accelerator

abstract:
  A laser pulse guided in a curved plasma channel can excite wakefields that
steer electrons along an arched trajectory. As the electrons are accelerated
along the curved channel, they emit synchrotron radiation. We present simple
analytical models and simulations examining laser pulse guiding, wakefield
generation, electron steering, and synchrotron emission in curved plasma
channels. For experimentally realizable parameters, a ~2 GeV electron emits 0.1
photons per cm with an average photon energy of multiple keV.


title:
Approximation of Quasi-Monte Carlo worst case error in weighted spaces
  of infinitely times smooth functions

abstract:
  In this paper, we consider Quasi-Monte Carlo (QMC) worst case error of
weighted smooth function classes in $C^\infty[0,1]^s$ by a digital net over
$\mathbb F_2$. We show that the ratio of the worst case error to the QMC
integration error of an exponential function is bounded above and below by
constants. This result provides us with a simple interpretation that a digital
net with small QMC integration error for an exponential function also gives the
small integration error for any function in this function space.


title: Complete Regularity: Kopperman's duality {\it \`{a} la quantale}

abstract:
  Nearly three decades from his celebrated result, we study a modern refinement
and strengthening of Kopperman's full metrisabilty of all topological spaces.
Within this new theory of \emph{V-spaces}, developed by Flagg and Weiss, we
investigate several topological notions and their metric counterpart. Among our
main results is the reconstruction, in terms of V-spaces, of Kopperman's
equivalence between symmetric value semigroups and completely regular
topologies. We conclude our work by revisiting some classical topological
results and their almost evident validity through this metric lens.


title: $L^p$ Hardy inequality on $C^{1,\gamma}$ domains

abstract:
  We consider the $L^p$ Hardy inequality involving the distance to the boundary
of a domain in the $n$-dimensional Euclidean space with nonempty compact
boundary. We extend the validity of known existence and non-existence results,
as well as the appropriate tight decay estimates for the corresponding
minimizers, from the case of domains of class $C^2$ to the case of domains of
class $C^{1,\gamma}$ with $\gamma \in (0,1]$. We consider both bounded and
exterior domains. The upper and lower estimates for the minimizers in the case
of exterior domains and the corresponding related non-existence result seem to
be new even for $C^2$-domains.


title:
FIB synthesis of Bi2Se3 1D nanowires demonstrating the co-existence of
  Shubnikov-de Haas oscillations and linear magnetoresistance

abstract:
  Since the discovery of topological insulators (TI), there are considerable
interests in demonstrating metallic surface states, their shielded robust
nature to the backscattering and study their properties at nanoscale dimensions
by fabricating nanodevices. Here we address an important scientific issue
related to TI whether one can clearly demonstrate the robustness of topological
surface states (TSS) to the presence of disorder that does not break any
fundamental symmetry. The simple straightforward method of FIB milling was used
to synthesize nanowires of Bi2Se3 which we believe an interesting route to test
robustness of TSS and obtained results are new compared to many of the earlier
papers on quantum transport in TI demonstrating robustness of metallic SS to
gallium doping. In presence of perpendicular magnetic field, we have observed
the co-existence of Shubnikov de Haas oscillations and linear magnetoresistance
which was systematically investigated at different channel lengths indicating
the Dirac dispersive surface states. The transport properties and estimated
physical parameters shown here demonstrate the robustness of SS to the
fabrication tools triggering flexibility to explore new exotic quantum
phenomena at nanodevice level.


title:
Learning Methods for Dynamic Topic Modeling in Automated Behaviour
  Analysis

abstract:
  Semi-supervised and unsupervised systems provide operators with invaluable
support and can tremendously reduce the operators load. In the light of the
necessity to process large volumes of video data and provide autonomous
decisions, this work proposes new learning algorithms for activity analysis in
video. The activities and behaviours are described by a dynamic topic model.
Two novel learning algorithms based on the expectation maximisation approach
and variational Bayes inference are proposed. Theoretical derivations of the
posterior of model parameters are given. The designed learning algorithms are
compared with the Gibbs sampling inference scheme introduced earlier in the
literature. A detailed comparison of the learning algorithms is presented on
real video data. We also propose an anomaly localisation procedure, elegantly
embedded in the topic modeling framework. The proposed framework can be applied
to a number of areas, including transportation systems, security and
surveillance.


title:
End-to-End Architecture Modularisation and Slicing for Next Generation
  Networks

abstract:
  The journey towards the deployment of next generation networks has recently
accelerated, driven by the joint effort of research and standards
organisations. Despite this fact, the overall picture is still unclear as
prioritization and understanding on several key concepts are not yet agreed by
major vendors and network providers. Network Slicing is one of the central
topics of the debate, and it is expected to become the key feature of next
generation networks, providing the flexibility required to support the variety
of 5G use cases and business. Network slices are seen as network operator
business, offering the possibility to provide flexible services and even
infrastructures to vertical industries and classical Telco customers alike.
Another key ingredient is the Architecture Modularisation concept, discussed in
this paper and regarded by the authors as the essential design principle to
build a flexible network architecture natively supporting Network Slicing.
According to this concept, conventional monolithic network functions, often
corresponding to physical network elements in the existing systems, are to
split into basic building blocks defined with the proper granularity, allowing
the definition of different logical architectures (i.e. different Network
Slices). In this paper, we further discuss a modularisation methodology as a
criteria to define the right set of basic building blocks. Defined through this
proposed methodology, the set of basic building blocks and the relating
interfacing model are discussed. The paper concludes by proposing a modular 5G
network architecture as candidate for next generation network standards.


title: A note on the Mittag--Leffler condition for Bredon-modules

abstract:
  In this note we show the Bredon-analogue of a result by Emmanouil and
Talelli, which gives a criterion when the homological and cohomological
dimensions of a countable group $G$ agree. We also present some applications to
groups of Bredon-homological dimension $1$.


title: Analysis of Link Formation, Persistence and Dissolution in NetSense Data

abstract:
  We study a unique behavioral network data set (based on periodic surveys and
on electronic logs of dyadic contact via smartphones) collected at the
University of Notre Dame.The participants are a sample of members of the
entering class of freshmen in the fall of 2011 whose opinions on a wide variety
of political and social issues and activities on campus were regularly recorded
- at the beginning and end of each semester - for the first three years of
their residence on campus. We create a communication activity network implied
by call and text data, and a friendship network based on surveys. Both networks
are limited to students participating in the NetSense surveys. We aim at
finding student traits and activities on which agreements correlate well with
formation and persistence of links while disagreements are highly correlated
with non-existence or dissolution of links in the two social networks that we
created. Using statistical analysis and machine learning, we observe several
traits and activities displaying such correlations, thus being of potential use
to predict social network evolution.


title: Relative K-stability for K\"ahler manifolds

abstract:
  We study the existence of extremal K\"ahler metrics on K\"ahler manifolds.
After introducing a notion of relative K-stability for K\"ahler manifolds, we
prove that K\"ahler manifolds admitting extremal K\"ahler metrics are
relatively K-stable. Along the way, we prove a general $L^p$ lower bound on the
Calabi functional involving test configurations and their associated numerical
invariants, answering a question of Donaldson.
  When the K\"ahler manifold is projective, our definition of relative
K-stability is stronger than the usual definition given by Sz\'ekelyhidi. In
particular our result strengthens the known results in the projective case
(even for constant scalar curvature K\"ahler metrics), and rules out a well
known counterexample to the "na\"ive" version of the Yau-Tian-Donaldson
conjecture in this setting.


title:
Influence of tangential displacement on the force of adhesion between a
  parabolic profile and plane surface

abstract:
  The force of adhesion of a rotationally symmetric indenter and an elastic
half-space is analyzed analytically and numerically using an extension of the
method of dimensionality reduction (MDR) for superimposed normal/tangential
adhesive contacts. In particular, the dependency of the critical adhesion force
on the simultaneously applied tangential force is obtained and the relevant
dimensionless parameters of the problem are identified. The developed method is
applicable straightforwardly to adhesive contacts of any bodies of revolution.


title:
Nodal intersections for random waves against a segment on the
  3-dimensional torus

abstract:
  We consider random Gaussian eigenfunctions of the Laplacian on the
three-dimensional flat torus, and investigate the number of nodal intersections
against a straight line segment. The expected intersection number, against any
smooth curve, is universally proportional to the length of the reference curve,
times the wavenumber, independent of the geometry. We found an upper bound for
the nodal intersections variance, depending on the arithmetic properties of the
straight line. The considerations made establish a close relation between this
problem and the theory of lattice points on spheres.


title: Wave emission and absorption at spectral singularities

abstract:
  We studied the critical dynamics of spectral singularities. The system
investigated is a coupled resonator array with a side-coupled loss (gain)
resonator. For a gain resonator, the system acts as a wave emitter at spectral
singularities. The reflection probability increased linearly over time. The
rate of increase is proportional to the width of the incident wave packet,
which served as the spectral singularity observer in the experiment. For a
lossy resonator, the system acts as a wave absorber. The emission and
absorption states at spectral singularities coalesce in a finite parity-time
(PT ) symmetric system that combined by the gain and loss structures cut from
corrresponding scattering systems at spectral singularities; in this case, the
PT -symmetric system is at an exceptional point with a 2 * 2 Jordan block. The
dynamics of the PT -symmetric system exhibit the characteristic of exceptional
points and spectral singularities.


title:
Hubbard-to-Heisenberg crossover (and efficient computation) of Drude
  weights at low temperatures

abstract:
  We illustrate how finite-temperature charge and thermal Drude weights of
one-dimensional systems can be obtained from the relaxation of initial states
featuring global (left-right) gradients in the chemical potential or
temperature. The approach is tested for spinless interacting fermions as well
as for the Fermi-Hubbard model, and the behaviour in the vicinity of singular
points (such as half filling or isotropic chains) is discussed. We present
technical details on how to implement the calculation in practice using the
density matrix renormalization group and show that the non-equilibrium dynamics
is often less demanding to simulate numerically and features simpler
finite-time transients than the corresponding linear response current
correlators; thus, new parameter regimes can become accessible. As an
application, we determine the thermal Drude weight of the Hubbard model for
temperatures T which are an order of magnitude smaller than those reached in
the equilibrium approach. This allows us to demonstrate that at low T and half
filling, thermal transport is successively governed by spin excitations and
described quantitatively by the Bethe ansatz Drude weight of the Heisenberg
chain.


title: Compositional Reasoning for Shared-variable Concurrent Programs

abstract:
  Scalable and automatic formal verification for concurrent systems is always
demanding. In this paper, we propose a verification framework to support
automated compositional reasoning for concurrent programs with shared
variables. Our framework models concurrent programs as succinct automata and
supports the verification of multiple important properties. Safety verification
and simulations of succinct automata are parallel compositional, and safety
properties of succinct automata are preserved under refinements. We generate
succinct automata from infinite state concurrent programs in an automated
manner. Furthermore, we propose the first automated approach to checking
rely-guarantee based simulations between infinite state concurrent programs. We
have prototyped our algorithms and applied our tool to the verification of
multiple refinements.


title:
On the Number of Periodic Points of Quadratic Dynamical Systems Modulo a
  Prime

abstract:
  In 2004 Vasiga and Shallit studied the number of periodic points of two
particular discrete quadratic maps modulo prime numbers. They found the
asymptotic behaviour of the sum of the number of periodic points for all primes
less than some bound, assuming the Extended Riemann Hypothesis. Later that same
year Chou and Shparlinski proved this asymptotic result without assuming any
unproven hypotheses.
  Inspired by this we perform experiments and find a striking pattern in the
behaviour of the sum of the number of periodic points for quadratic maps other
than the two particular ones studied previously. From simulations it appears
that the sum of the number of periodic points of all quadratic maps of this
type behave the same. Finally we find that numerically the distribution of the
amounts of periodic points seems to be Rayleigh.


title: Strong Neutrosophic Graphs and Subgraph Topological Subspaces

abstract:
  In this book authors for the first time introduce the notion of strong
neutrosophic graphs. They are very different from the usual graphs and
neutrosophic graphs. Using these new structures special subgraph topological
spaces are defined. Further special lattice graph of subgraphs of these graphs
are defined and described. Several interesting properties using subgraphs of a
strong neutrosophic graph are obtained. Several open conjectures are proposed.
These new class of strong neutrosophic graphs will certainly find applications
in Neutrosophic Cognitive Maps (NCM), Neutrosophic Relational Maps (NRM) and
Neutrosophic Relational Equations (NRE) with appropriate modifications.


title: The new hybrid COAW method for solving multi-objective problems

abstract:
  In this article using Cuckoo Optimization Algorithm and simple additive
weighting method the hybrid COAW algorithm is presented to solve
multi-objective problems. Cuckoo algorithm is an efficient and structured
method for solving nonlinear continuous problems. The created Pareto frontiers
of the COAW proposed algorithm are exact and have good dispersion. This method
has a high speed in finding the Pareto frontiers and identifies the beginning
and end points of Pareto frontiers properly. In order to validation the
proposed algorithm, several experimental problems were analyzed. The results of
which indicate the proper effectiveness of COAW algorithm for solving
multi-objective problems.


title:
Benchmarking Web-testing - Selenium versus Watir and the Choice of
  Programming Language and Browser

abstract:
  Context: Selenium is claimed to be the most popular software test automation
tool. Past academic works have mainly neglected testing tools in favor of more
methodological topics. Objective: We investigated the performance of
web-testing tools, to provide empirical evidence supporting choices in software
test tool selection and configuration. Method: We used 4*5 factorial design to
study 20 different configurations for testing a web-store. We studied 5
programming language bindings (C#, Java, Python, and Ruby for Selenium, while
Watir supports Ruby only) and 4 browsers (Google Chrome, Internet Explorer,
Mozilla Firefox and Opera). Performance was measured with execution time,
memory usage, length of the test scripts and stability of the tests. Results:
Considering all measures the best configuration was Selenium with Python
language binding for Chrome. Selenium with Python bindings was the best option
for all browsers. The effect size of the difference between the slowest and
fastest configuration was very high (Cohens d=41.5, 91% increase in execution
time). Overall Internet Explorer was the fastest browser while having the worst
results in the stability. Conclusions: We recommend benchmarking tools before
adopting them. Weighting of factors, e.g. how much test stability is one
willing to sacrifice for faster performance, affects the decision.


title:
Stable Soliton Excitations in Modulational Instability Regime with the
  Fourth-order Effects

abstract:
  We study the correspondence between modulational instability and types of
fundamental nonlinear excitation in a nonlinear fiber with both third-order and
fourth-order effects. Some stable soliton excitations are obtained in
modulational instability regime, which have not been found in nonlinear fibers
with second-order effects and third-order effects. Explicit analysis suggests
that the stable soliton existence is related with the modulation stability
circle in the modulation instability regime, and they just exist in the
modulational instability regime outside of the modulational stability circle.
It should be emphasized that the stable soliton just exist with two special
profiles on a continuous wave background with certain frequency. The evolution
stability of the solitons is tested numerically, which indicate they are robust
against perturbations even in modulation instability regime. The further
analysis indicates that the solitons in modulational instability regime are
caused by the fourth-order effects.


title: On Verifying Causal Consistency

abstract:
  Causal consistency is one of the most adopted consistency criteria for
distributed implementations of data structures. It ensures that operations are
executed at all sites according to their causal precedence. We address the
issue of verifying automatically whether the executions of an implementation of
a data structure are causally consistent. We consider two problems: (1)
checking whether one single execution is causally consistent, which is relevant
for developing testing and bug finding algorithms, and (2) verifying whether
all the executions of an implementation are causally consistent.
  We show that the first problem is NP-complete. This holds even for the
read-write memory abstraction, which is a building block of many modern
distributed systems. Indeed, such systems often store data in key-value stores,
which are instances of the read-write memory abstraction. Moreover, we prove
that, surprisingly, the second problem is undecidable, and again this holds
even for the read-write memory abstraction. However, we show that for the
read-write memory abstraction, these negative results can be circumvented if
the implementations are data independent, i.e., their behaviors do not depend
on the data values that are written or read at each moment, which is a
realistic assumption.


title: On robust feedback for systems with multidimensional control

abstract:
  The paper deals with local robust feedback synthesis for systems with
multidimensional control and unknown bounded perturbations. Using
V.~I.~Korobov's controllability function method, we construct a bounded control
which steers an arbitrary initial point to the origin in some finite time; an
estimate from above for the time of motion is given. We have found the range of
a segment where the perturbations can vary. As an example we consider the
problem of stopping the oscillations of the system of two coupled pendulums.


title:
Towards High-Efficiency Cascading Outage Simulation and Analysis in
  Power Systems: A Sequential Importance Sampling Approach

abstract:
  This paper addresses how to improve the computational efficiency and
estimation reliability in cascading outage analysis. We first formulate a
cascading outage as a Markov chain with specific state space and transition
probability by leveraging the Markov property of cascading outages. It provides
a rigorous formulation that allows analytic investigation on cascading outages
in the framework of standard mathematical statistics. Then we derive a
sequential importance sampling (SIS) based simulation strategy for cascading
outage simulation and blackout risk analysis with theoretical justification.
Numerical experiments manifest that the proposed SIS strategy can significantly
bring down the number of simulations and reduce the estimation variance of
cascading outage analysis compared with the traditional Monte Carlo simulation
strategy.


title:
Graded index SCH transistor laser: Analysis of various confinement
  structures

abstract:
  New configuration of confinement structure is utilized to improve
optoelectronic performances, including threshold current, AC current gain as
well as optical bandwidth and optical output power of single quantum well
transistor laser. Considering the drift component in addition to the diffusion
term in electron current density, a new continuity equation is developed to
analyze the proposed structures. Physical parameters including, electron
mobility, recombination lifetime, optical confinement factor, electron capture
time and photon lifetime is calculated for new structures. Based on solving
continuity equation in separate confinement heterostructures, threshold current
reduces 67% and optical output power increases 37%.


title: Anomalous Hall effect and magnetic orderings in nanothick V$_5$S$_8$

abstract:
  The rise of graphene marks the advent of two-dimensional atomic crystals,
which have exhibited a cornucopia of intriguing properties, such as the integer
and fractional quantum Hall effects, valley Hall effect, charge density waves
and superconductivity, to name a few. Yet, magnetism, a property of extreme
importance in both science and technology, remains elusive. There is a
paramount need for magnetic two-dimensional crystals. With the availability of
many magnetic materials consisting of van der Waals coupled two-dimensional
layers, it thus boils down to the question of how the magnetic order will
evolve with reducing thickness. Here we investigate the effect of thickness on
the magnetic ordering in nanothick V$_5$S$_8$. We uncover an anomalous Hall
effect, by which the magnetic ordering in V$_5$S$_8$ down to 3.2 nm is probed.
With decreasing thickness, a breakdown of antiferromagnetism is evident,
followed by a spin-glass-like state. For thinnest samples, a weak ferromagnetic
ordering emerges. The results not only show an interesting effect of reducing
thickness on the magnetic ordering in a potential candidate for magnetic
two-dimensional crystals, but demonstrate the anomalous Hall effect as a useful
characterization tool for magnetic orderings in two-dimensional systems.


title:
The impact of magnetic fields on the chemical evolution of the
  supernova-driven ISM

abstract:
  We present three-dimensional magneto-hydrodynamical simulations of the
self-gravitating interstellar medium (ISM) in a periodic (256 pc)$^3$ box with
a mean number density of 0.5 cm$^{-3}$. At a fixed supernova rate we
investigate the multi-phase ISM structure, H$_{2}$ molecule formation and
density-magnetic field scaling for varying initial magnetic field strengths (0,
$6\times 10^{-3}$, 0.3, 3 $\mu$G). All magnetic runs saturate at mass weighted
field strengths of $\sim$ 1 $-$ 3 $\mu$G but the ISM structure is notably
different. With increasing initial field strengths (from $6\times 10^{-3}$ to 3
$\mu$G) the simulations develop an ISM with a more homogeneous density and
temperature structure, with increasing mass (from 5% to 85%) and volume filling
fractions (from 4% to 85%) of warm (300 K $<$ T $<$ 8000 K) gas, with
decreasing volume filling fractions (VFF) from $\sim$ 35% to $\sim$ 12% of hot
gas (T $> 10^5$ K) and with a decreasing H$_{2}$ mass fraction (from 70% to $<$
1%). Meanwhile the mass fraction of gas in which the magnetic pressure
dominates over the thermal pressure increases by a factor of 10, from 0.07 for
an initial field of $6\times 10^{-3}$ $\mu$G to 0.7 for a 3 $\mu$G initial
field. In all but the simulations with the highest initial field strength
self-gravity promotes the formation of dense gas and H$_{2}$, but does not
change any other trends. We conclude that magnetic fields have a significant
impact on the multi-phase, chemical and thermal structure of the ISM and
discuss potential implications and limitations of the model.


title:
Distributed MPC: Guaranteeing Global Stabilizability from Locally
  Designed Tubes

abstract:
  This paper studies a fundamental relation that exists between stabilizability
assumptions usually employed in distributed model predictive control
implementations, and the corresponding notions of invariance implicit in such
controllers. The relation is made explicit in the form of a theorem that
presents sufficient conditions for global stabilizability. It is shown that
constraint admissibility of local robust controllers is sufficient for the
global closed-loop system to be stable, and how these controllers are related
to more complex forms of control such as tube-based distributed model
predictive control implementations.


title: Rectification and non-Gaussian diffusion in heterogeneous media

abstract:
  We show that when Brownian motion takes place in a heterogeneous medium, the
presence of local forces and transport coefficients leads to deviations from a
Gaussian probability distribution that make that the ratio between forward and
backward probabilities depends on the nature of the host medium, on local
forces and also on time. We have applied our results to two situations:
diffusion in a disordered medium and diffusion in a confined system. For such
scenarios we have shown that our theoretical predictions are in very good
agreement with numerical results. Moreover we have shown that the deviations
from the Gaussian solution lead to the onset of rectification. Our predictions
could be used to detect the presence of local forces and to characterize the
intrinsic short-scale properties of the host medium, a problem of current
interest in the study of micro and nano-systems.


title: Skew symmetric logarithms and geodesics on $O_n(\RR)$

abstract:
  We investigate the connections between the differential-geometric properties
of the exponential map from the space of real skew symmetric matrices onto the
group of real special orthogonal matrices and the manifold of real orthogonal
matrices equipped with the Riemannian structure induced by the Frobenius
metric.


title:
Stochastic Control and Differential Games with Path-Dependent Influence
  of Controls on Dynamics and Running Cost

abstract:
  In this paper, we consider the functional It\^o calculus framework to find a
path-dependent version of the Hamilton-Jacobi-Bellman equation for stochastic
control problems that feature dynamics and running cost that depend on the path
of the control. We also prove a Dynamic Programming Principle for such
problems. We apply our results to path-dependence of the delay type. We further
study Stochastic Differential Games in this context.


title:
Counterterm method in dilaton gravity and the critical behavior of
  dilaton black holes with power-Maxwell field

abstract:
  We investigate the critical behavior of an $(n+1)$-dimensional topological
dilaton black holes, in an extended phase space in both canonical and
grand-canonical ensembles, when the gauge field is in the form of power-Maxwell
field. In order to do this we introduce for the first time the counterterms
that remove the divergences of the action in dilaton gravity for the solutions
with curved boundary. Using the counterterm method, we calculate the conserved
quantities and the action and therefore Gibbs free energy in both the canonical
and grand-canonical ensembles. We treat the cosmological constant as a
thermodynamic pressure, and its conjugate quantity as a thermodynamic volume.
In the presence of power-Maxwell field, we find an analogy between the
topological dilaton black holes with van der Walls liquid-gas system in all
dimensions provided the dilaton coupling constant $\alpha$ and the power
parameter $p$ are chosen properly. Interestingly enough, we observe that the
power-Maxwell dilaton black holes admit the phase transition in both canonical
and grand-canonical ensembles. This is in contrast to RN-AdS,
Einstein-Maxwell-dilaton and Born-Infeld-dilaton black holes, which only admit
the phase transition in the canonical ensemble. Besides, we calculate the
critical quantities and show that they depend on $\alpha$, $n$ and $p$.
Finally, we obtain the critical exponents in two ensembles and show that they
are independent of the model parameters and have the same values as mean field
theory.


title: Deep Neural Networks for HDR imaging

abstract:
  We propose novel methods of solving two tasks using Convolutional Neural
Networks, firstly the task of generating HDR map of a static scene using
differently exposed LDR images of the scene captured using conventional cameras
and secondly the task of finding an optimal tone mapping operator that would
give a better score on the TMQI metric compared to the existing methods. We
quantitatively show the performance of our networks and illustrate the cases
where our networks performs good as well as bad.


title: Integrable Lattice Models From Gauge Theory

abstract:
  These notes provide an introduction to recent work by Kevin Costello in which
integrable lattice models of classical statistical mechanics in two dimensions
are understood in terms of quantum gauge theory in four dimensions. This
construction will be compared to the more familiar relationship between quantum
knot invariants in three dimensions and Chern-Simons gauge theory. (Based on a
Whittaker Colloquium at the University of Edinburgh and a lecture at Strings
2016 in Beijing.)

categories: hep-th cond-mat.stat-mech math-ph math.MP


title: Covariant holographic entanglement negativity

abstract:
  We propose a covariant holographic conjecture for the entanglement negativity
of mixed states in bipartite systems described by $d$-dimensional conformal
field theories dual to bulk non static $AdS_{d+1}$ configurations. Application
of our conjecture to $(1+1)$-dimensional conformal field theories dual to bulk
rotating BTZ black holes exactly reproduces the corresponding entanglement
negativity in the large central charge limit and characterizes the distillable
entanglement. We further demonstrate that our conjecture applied to the case of
bulk extremal rotating BTZ black holes also characterizes the entanglement
negativity for the chiral half of the corresponding zero temperature
$(1+1)$-dimensional holographic conformal field theories.


title:
Non-destructive detection of ions using atom-cavity collective strong
  coupling

abstract:
  We present a technique, based on atoms coupled to an optical cavity, for
non-destructive detection of trapped ions. We demonstrate the vacuum-Rabi
splitting (VRS), arising due to the collective strong coupling of ultracold Rb
atoms to a cavity, to change in presence of trapped Rb+ ions. The Rb+ ions are
optically dark and the Rb atoms are prepared in a dark magneto-optical trap
(MOT). The VRS is measured on an optically open transition of the initially
dark Rb atoms. The measurement itself is fast, non-destructive and has
sufficient fidelity to permit the measurement of atomic-state selective
ion-atom collision rate. This demonstration illustrates a method based on
atom-cavity coupling to measure two particle interactions generically and
non-destructively.

categories: physics.atom-ph cond-mat.quant-gas physics.optics quant-ph


title:
On computing the distance to stability for matrices using linear
  dissipative Hamiltonian systems

abstract:
  In this paper, we consider the problem of computing the nearest stable matrix
to an unstable one. We propose new algorithms to solve this problem based on a
reformulation using linear dissipative Hamiltonian systems: we show that a
matrix $A$ is stable if and only if it can be written as $A = (J-R)Q$, where
$J=-J^T$, $R \succeq 0$ and $Q \succ 0$ (that is, $R$ is positive semidefinite
and $Q$ is positive definite). This reformulation results in an equivalent
optimization problem with a simple convex feasible set. We propose three
strategies to solve the problem in variables $(J,R,Q)$: (i) a block coordinate
descent method, (ii) a projected gradient descent method, and (iii) a fast
gradient method inspired from smooth convex optimization. These methods require
$\mathcal{O}(n^3)$ operations per iteration, where $n$ is the size of $A$. We
show the effectiveness of the fast gradient method compared to the other
approaches and to several state-of-the-art algorithms.


title: An Insight in Explaining the Stress Distribution in and around EGS

abstract:
  Developing an Enhanced Geothermal System, otherwise known as EGS, is a
complex process and is dependent on range of geological and operating
variables. Stresses in and around EGS are believed to be either sound and
non-harming or violent and catastrophic among different groups involved,
directly or indirectly, in EGS. Pros and cons of EGS have been under discussion
and research for a while now. This paper addresses issues associated with
stress redistribution during and after working cycle of EGS and gives a new
insight in understanding the behavior of stresses redistribution in and around
basement rock. As the basement rock is thermo-elastically connected to the
country rock, newly generated stresses interact with the existing in-situ
stresses under prevailing conditions of geological, design and operating
variables. Variables dictating the continuous, safe and efficient working of
EGS are also outlined in detailed sections. Guidelines for future of the
research related to stress redistribution in EGS are also part of this paper.


title: Uncertainty propagation within the UNEDF models

abstract:
  The parameters of the nuclear energy density have to be adjusted to
experimental data. As a result they carry certain uncertainty which then
propagates to calculated values of observables. In the present work we quantify
the statistical uncertainties of binding energies, proton quadrupole moments,
and proton matter radius for three UNEDF Skyrme energy density functionals by
taking advantage of the knowledge of the model parameter uncertainties. We find
that the uncertainty of UNEDF models increases rapidly when going towards
proton or neutron rich nuclei. We also investigate the impact of each model
parameter on the total error budget.


title:
A bioinformatics system for searching Co-Occurrence based on
  Co-Operational Formation with Advanced Method (COCOFAM)

abstract:
  Literature analysis is a key step in obtaining background information in
biomedical research. However, it is difficult for researchers to obtain
knowledge of their interests in an efficient manner because of the massive
amount of the published biomedical literature. Therefore, efficient and
systematic search strategies are required, which allow ready access to the
substantial amount of literature. In this paper, we propose a novel search
system, named Co-Occurrence based on Co-Operational Formation with Advanced
Method(COCOFAM) which is suitable for the large-scale literature analysis.
COCOFAM is based on integrating both Spark for local clusters and a global job
scheduler to gather crowdsourced co-occurrence data on global clusters. It will
allow users to obtain information of their interests from the substantial
amount of literature.


title:
Increasing efficiency of a wireless energy transfer system by spatial
  translational transformation

abstract:
  An optical translational projector (OTP) designed by transformation optics is
applied to improve the energy transfer efficiency in a wireless energy transfer
(WET) system. Numerical simulation results show our OTP can greatly enhance the
energy transfer efficiency (e.g. nearly 2 orders, compared to the case without
our OTP) in WET systems, which is much larger than previous methods (e.g.
magnetic super-lens). A 3D reduced OTP composed by layered isotropic magnetic
materials is designed, whose performance has been verified by 3D numerical
simulations in 10MHz. We also study the influence of loss of metamaterials on
the performance of proposed OTP.


title:
An $L^2-$stability estimate for periodic nonuniform sampling in higher
  dimensions

abstract:
  We consider sampling strategies for a class of multivariate bandlimited
functions $f$ that have a spectrum consisting of disjoint frequency bands.
Taking advantage of the special spectral structure, we provide formulas
relating $f$ to the samples $f(y), y\in X$, where $X$ is a periodic nonuniform
sampling set. In this case, we show that the reconstruction can be viewed as an
iterative process involving certain Vandermonde matrices, resulting in a link
between the invertibility of these matrices to the existence of certain
sampling sets that guarantee a unique recovery. Furthermore, estimates of
inverse Vandermonde matrices are used to provide explicit $L^{2}$-stability
estimates for the reconstruction of this class of functions.


title: Ordinal Common-sense Inference

abstract:
  Humans have the capacity to draw common-sense inferences from natural
language: various things that are likely but not certain to hold based on
established discourse, and are rarely stated explicitly. We propose an
evaluation of automated common-sense inference based on an extension of
recognizing textual entailment: predicting ordinal human responses on the
subjective likelihood of an inference holding in a given context. We describe a
framework for extracting common-sense knowledge from corpora, which is then
used to construct a dataset for this ordinal entailment task. We train a neural
sequence-to-sequence model on this dataset, which we use to score and generate
possible inferences. Further, we annotate subsets of previously established
datasets via our ordinal annotation protocol in order to then analyze the
distinctions between these and what we have constructed.


title: Scala-gopher: CSP-style programming techniques with idiomatic Scala

abstract:
  Cala-gopher is a library-level Scala implementation of communication sequence
process constructs: channels, selectors (similar to analogical constructs in
Limbo or Go) transputers (similar to Occam proc) and a set of high-level
operations on top of akka and SIP-22 async. The framework integrates CSP-style
programming into standard Scala concurrency environment via idiomatic API. This
allows usage of communication patterns, well known in Go world, but not easy
expressable in mainstream scala concurrency frameworks, along with algebraic
approach for composing computation builders. Besides, we want to discuss
current implementation issues and future directions in the context of evolving
of compiler and libraries ecosystem.


title:
Space-Like Particle Production: an Interpretation Based on the Majorana
  Equation

abstract:
  This study reconsiders the decay of an ordinary particle in bradyons,
tachyons and luxons in the field of the relativistic quantum mechanics. Lemke
already investigated this from the perspective of covariant kinematics. Since
the decay involves both spacelike and timelike particles, the study uses the
Majorana equation for particles with an arbitrary spin. The equation describes
the tachyonic and bradyonic realms of massive particles, and approaches the
problem of how spacelike particles might develop. This method confirms the
kinematic constraints that Lemke theory provided and proves that some possible
decays are more favourable than others are.


title: Three-body model for the two-neutron decay of $^{16}$Be

abstract:
  While diproton decay was first theorized in 1960 and first measured in 2002,
it was first observed only in 2012. The measurement of $^{14}$Be in coincidence
with two neutrons suggests that $^{16}$Be does decay through the simultaneous
emission of two strongly correlated neutrons. In this work, we construct a full
three-body model of $^{16}$Be (as $^{14}$Be + n + n) in order to investigate
its configuration in the continuum and in particular the structure of its
ground state. In order to describe the three-body system, effective n-$^{14}$Be
potentials were constructed, constrained by the experimental information on
$^{15}$Be. The hyperspherical R-matrix method was used to solve the three-body
scattering problem, and the resonance energy of $^{16}$Be was extracted from a
phase shift analysis. In order to reproduce the experimental resonance energy
of $^{16}$Be within this three-body model, a three-body interaction was needed.
For extracting the width of the ground state of $^{16}$Be, we use the full
width at half maximum of the derivative of the three-body phase shifts and the
width of the three-body elastic scattering cross section. Our results confirm a
dineutron structure for $^{16}$Be, dependent on the internal structure of the
subsystem $^{15}$Be.


title:
Time- and memory-efficient representation of complex mesoscale
  potentials

abstract:
  We apply the modern technique of approximation of multivariate functions -
tensor train cross approximation - to the problem of the description of
physical interactions between complex-shaped bodies in a context of
computational nanomechanics. In this note we showcase one particular example -
van der Waals interactions between two cylindrical bodies - relevant to
modeling of carbon nanotube systems. The potential is viewed as a tensor
(multidimensional table) which is represented in compact form with the help of
tensor train decomposition. The described approach offers a universal solution
for the description of van der Waals interactions between complex-shaped
nanostructures and can be used within the framework of such systems of
mesoscale modeling as recently emerged mesoscopic distinct element method
(MDEM).


title:
Hybrid CPU-GPU generation of the Hamiltonian and Overlap matrices in
  FLAPW methods

abstract:
  In this paper we focus on the integration of high-performance numerical
libraries in ab initio codes and the portability of performance and
scalability. The target of our work is FLEUR, a software for electronic
structure calculations developed in the Forschungszentrum J\"ulich over the
course of two decades. The presented work follows up on a previous effort to
modernize legacy code by re-engineering and rewriting it in terms of highly
optimized libraries. We illustrate how this initial effort to get efficient and
portable shared-memory code enables fast porting of the code to emerging
heterogeneous architectures. More specifically, we port the code to nodes
equipped with multiple GPUs. We divide our study in two parts. First, we show
considerable speedups attained by minor and relatively straightforward code
changes to off-load parts of the computation to the GPUs. Then, we identify
further possible improvements to achieve even higher performance and
scalability. On a system consisting of 16-cores and 2 GPUs, we observe speedups
of up to 5x with respect to our optimized shared-memory code, which in turn
means between 7.5x and 12.5x speedup with respect to the original FLEUR code.


title: Three Perspectives on Complexity $-$ Entropy, Compression, Subsymmetry

abstract:
  There is no single universally accepted definition of "Complexity". There are
several perspectives on complexity and what constitutes complex behaviour or
complex systems, as opposed to regular, predictable behaviour and simple
systems. In this paper, we explore the following perspectives on complexity:
"effort-to-describe" (Shannon entropy $H$, Lempel-Ziv complexity $LZ$),
"effort-to-compress" ($ETC$ complexity) and "degree-of-order" (Subsymmetry or
$SubSym$). While Shannon entropy and $LZ$ are very popular and widely used,
$ETC$ is a recently proposed measure for time series. In this paper, we also
propose a novel normalized measure $SubSym$ based on the existing idea of
counting the number of subsymmetries or palindromes within a sequence. We
compare the performance of these complexity measures on the following tasks: a)
characterizing complexity of short binary sequences of lengths 4 to 16, b)
distinguishing periodic and chaotic time series from 1D logistic map and 2D
H\'{e}non map, and c) distinguishing between tonic and irregular spiking
patterns generated from the "Adaptive exponential integrate-and-fire" neuron
model. Our study reveals that each perspective has its own advantages and
uniqueness while also having an overlap with each other.


title:
Seafloor identification in sonar imagery via simulations of Helmholtz
  equations and discrete optimization

abstract:
  We present a multiscale approach for identifying features in ocean beds by
solving inverse problems in high frequency seafloor acoustics. The setting is
based on Sound Navigation And Ranging (SONAR) imaging used in scientific,
commercial, and military applications. The forward model incorporates
multiscale simulations, by coupling Helmholtz equations and geometrical optics
for a wide range of spatial scales in the seafloor geometry. This allows for
detailed recovery of seafloor parameters including material type. Simulated
backscattered data is generated using numerical microlocal analysis techniques.
In order to lower the computational cost of the large-scale simulations in the
inversion process, we take advantage of a pre-computed library of
representative acoustic responses from various seafloor parameterizations.


title: SDSS-IV MaNGA: Bulge-Disc Decomposition of IFU Datacubes (BUDDI)

abstract:
  With the availability of large integral-field unit (IFU) spectral surveys of
nearby galaxies, there is now the potential to extract spectral information
from across the bulges and discs of galaxies in a systematic way. This
information can address questions such as how these components built up with
time, how galaxies evolve and whether their evolution depends on other
properties of the galaxy such as its mass or environment. We present BUDDI, a
new approach to fit the two-dimensional light profiles of galaxies as a
function of wavelength to extract the spectral properties of these galaxies'
discs and bulges. The fitting is carried out using GalfitM, a modified form of
Galfit which can fit multi-waveband images simultaneously. The benefit of this
technique over traditional multi-waveband fits is that the stellar populations
of each component can be constrained using knowledge over the whole image and
spectrum available. The decomposition has been developed using commissioning
data from the SDSS-IV Mapping Nearby Galaxies at APO (MaNGA) survey with
redshifts z<0.14 and coverage of at least 1.5 effective radii for a spatial
resolution of 2.5 arcsec FWHM and field of view of >22 arcsec, but can be
applied to any IFU data of a nearby galaxy with similar or better spatial
resolution and coverage. We present an overview of the fitting process, the
results from our tests, and we finish with example stellar population analyses
of early-type galaxies from the MaNGA survey to give an indication of the
scientific potential of applying bulge-disc decomposition to IFU data.


title: Variational Methods for Biomolecular Modeling

abstract:
  Structure, function and dynamics of many biomolecular systems can be
characterized by the energetic variational principle and the corresponding
systems of partial differential equations (PDEs). This principle allows us to
focus on the identification of essential energetic components, the optimal
parametrization of energies, and the efficient computational implementation of
energy variation or minimization. Given the fact that complex biomolecular
systems are structurally non-uniform and their interactions occur through
contact interfaces, their free energies are associated with various interfaces
as well, such as solute-solvent interface, molecular binding interface, lipid
domain interface, and membrane surfaces. This fact motivates the inclusion of
interface geometry, particular its curvatures, to the parametrization of free
energies. Applications of such interface geometry based energetic variational
principles are illustrated through three concrete topics: the multiscale
modeling of biomolecular electrostatics and solvation that includes the
curvature energy of the molecular surface, the formation of microdomains on
lipid membrane due to the geometric and molecular mechanics at the lipid
interface, and the mean curvature driven protein localization on membrane
surfaces. By further implicitly representing the interface using a phase field
function over the entire domain, one can simulate the dynamics of the interface
and the corresponding energy variation by evolving the phase field function,
achieving significant reduction of the number of degrees of freedom and
computational complexity. Strategies for improving the efficiency of
computational implementations and for extending applications to coarse-graining
or multiscale molecular simulations are outlined.


title: Shadow of a Charged Rotating Non-Commutative Black Hole

abstract:
  This paper investigates the shadow of a charged rotating non-commutative
black hole. For this purpose, we first formulate the null geodesics and study
the effects of non-commutative charge on the photon orbit. We then explore the
effect of spin, angle of inclination as well as non-commutative charge on the
silhouette of the shadow. It is found that shape of the shadow deviates from
the circle with the decrease in the non-commutative charge. We also discuss
observable quantities to study the deformation and distortion in the shadow
cast by the black hole which decreases for small values of non-commutative
charge. Finally, we study the shadows in the presence of plasma. We conclude
that the non-commutativity has a great impact on the black hole shadow.


title:
Effects of system-bath coupling on Photosynthetic heat engine: A polaron
  master equation approach

abstract:
  In this paper, we apply the polaron master equation, which offers the
possibilities to interpolate between weak and strong system-bath coupling, to
study how system-bath couplings affect charge transfer processes in Photosystem
II reaction center (PSII RC) inspired quantum heat engine (QHE) model in a wide
parameter range. The effects of bath correlation and temperature, together with
the combined effects of these factors are also discussed in details. The
results show a variety of dynamical behaviours. We interpret these results in
terms of noise-assisted transport effect and dynamical localization which
correspond to two mechanisms underpinning the transfer process in
photosynthetic complexes: One is resonance energy transfer and the other is
dynamical localization effect captured by the polaron master equation. The
effects of system-bath coupling and bath correlation are incorporated in the
effective system-bath coupling strength determining whether noise-assisted
transport effect or dynamical localization dominates the dynamics and
temperature modulates the balance of the two mechanisms. Furthermore, these two
mechanisms can be attributed to one physical origin: bath-induced fluctuations.
The two mechanisms is manifestations of dual role played by bath-induced
fluctuations within respective parameter range. In addition, we find that the
effec- tive voltage of QHE exhibits superior robustness with respect to the
bath noise as long as the system-coupling strength is not too large.


title:
Comment on "Gleason-Type Theorem for Projective Measurements, Including
  Qubits" by F. De Zela

abstract:
  It has recently been claimed by De Zela that Gleason's theorem, for
probability measures on the lattice of projection operators, can be extended to
qubits by adding assumptions related to continuity and the existence of
'eigenstates'. This amounts to a claim of the derivation of Born's rule for
Hermitian qubit observables. I point out a simple counterexample, and the flaw
in De Zela's derivation (these are equally applicable to the repetition of the
derivation given in a recent Reply). I also briefly discuss a valid extension
to qubits given by Busch.


title: Surface effects on ferromagnetic resonance in magnetic nanocubes

abstract:
  We study the effect of surface anisotropy on the spectrum of spin-wave
excitations in a magnetic nanocluster and compute the corresponding absorbed
power. For this, we develop a general numerical method based on the (undamped)
Landau-Lifshitz equation, either linearized around the equilibrium state
leading to an eigenvalue problem or solved using a symplectic technique. For
box-shaped clusters, the numerical results are favorably compared to those of
the finite-size linear spin-wave theory. Our numerical method allows us to
disentangle the contributions of the core and surface spins to the spectral
weight and absorbed power. In regard to the recent developments in synthesis
and characterization of assemblies of well defined nano-elements, we study the
effects of free boundaries and surface anisotropy on the spin-wave spectrum in
iron nanocubes and give orders of magnitude of the expected spin-wave
resonances. For an 8 nm iron nanocube, we show that the absorbed power spectrum
should exhibit a low-energy peak around 10 GHz, typical of the uniform mode,
followed by other low-energy features that couple to the uniform mode but with
a stronger contribution from the surface. There are also high-frequency
exchange-mode peaks around 60 GHz.


title:
Determination of the number of participating nucleons in p+p
  interactions at SPS energies

abstract:
  In the past the analyses of inelastic p+p collision for example in terms of
the hadron gas model have assumed that always both protons participate in the
interaction. In this article we show that (at sqrt(s) = 17.3 GeV ) on average
only 1,89 protons are interacting. Measurements of the mean multiplicities of
protons, neutrons, charged pions, charged kaons and {\Lambda} hyperons allow to
compute the number of initial state nucleons using conservation of baryon
number, strangeness, and isospin. We further argue that once the number of
initial state nucleons is given and the mean multiplicities of protons and
charged pions are known in p+p interactions at center-of-mass energies below a
few tens of GeV, the yields of net neutrons, kaons, and hyperons can be
estimated with a precision of a few percent using again baryon and isospin
conservation.


title: Dual Quaternion Variational Integrator for Rigid Body Dynamic Simulation

abstract:
  We introduce a symplectic dual quaternion variational integrator(DQVI) for
simulating single rigid body motion in all six degrees of freedom. Dual
quaternion is used to represent rigid body kinematics and one-step Lie group
variational integrator is used to conserve the geometric structure, energy and
momentum of the system during the simulation. The combination of these two
becomes the first Lie group variational integrator for rigid body simulation
without decoupling translations and rotations. Newton-Raphson method is used to
solve the recursive dynamic equation. This method is suitable for real-time
rigid body simulations with high precision under large time step. DQVI respects
the symplectic structure of the system with excellent long-term conservation of
geometry structure, momentum and energy. It also allows the reference point and
6-by-6 inertia matrix to be arbitrarily defined, which is very convenient for a
variety of engineering problems.


title: A novel 2D non-stationary wideband massive MIMO channel model

abstract:
  In this paper, a novel two-dimensional (2D) non-stationary wideband
geometry-based stochastic model (GBSM) for massive multiple-input
multiple-output (MIMO) communication systems is proposed. Key characteristics
of massive MIMO channels such as near field effects and cluster evolution along
the array are addressed in this model. Near field effects are modelled by a
second-order approximation to spherical wavefronts, i.e., parabolic wavefronts,
leading to linear drifts of the angles of multipath components (MPCs) and
non-stationarity along the array. Cluster evolution along the array involving
cluster (dis)appearance and smooth average power variations is considered.
Cluster (dis)appearance is modeled by a two-state Markov process and smooth
average power variations are modelled by a spatial lognormal process.
Statistical properties of the channel model such as time autocorrelation
function (ACF), spatial cross-correlation function (CCF), and cluster average
power and Rician factor variations over the array are derived. Finally,
simulation results are presented and analyzed, demonstrating that parabolic
wavefronts and cluster soft evolution are good candidates to model important
massive MIMO channel characteristics.


title: Symbols and exact regularity of symmetric pseudo-splines of any arity

abstract:
  Pseudo-splines form a family of subdivision schemes that provide a natural
blend between interpolating schemes and approximating schemes, including the
Dubuc-Deslauriers schemes and B-spline schemes. Using a generating function
approach, we derive expressions for the symbols of the symmetric $m$-ary
pseudo-spline subdivision schemes. We show that their masks have positive
Fourier transform, making it possible to compute the exact H\"older regularity
algebraically as a logarithm of the spectral radius of a matrix. We apply this
method to compute the regularity explicitly in some special cases, including
the symmetric binary, ternary, and quarternary pseudo-spline schemes.


title: The Quantum Trihedron

abstract:
  The convex hull on three points in two dimensional euclidean space of three
flat edges (trihedron) was studied. The Bohr-Sommerfeld quantization of the
area of space is performed. It is shown that it reproduces exactly the
equidistant spacing spectrum found elsewhere.


title: Discussion of the loop formula for the fermionic determinant

abstract:
  A formula expressing the fermionic determinant (a large order polynomial) as
an infinite product of smaller determinants is derived and discussed. These
smaller determinants are of a fixed size, independent of the size of the
lattice and are indexed by loops of increasing length.


title:
Properties of invariant measures in dynamical systems with the shadowing
  property

abstract:
  For dynamical systems with the shadowing property, we provide a method of
approximation of invariant measures by ergodic measures supported on odometers
and their almost 1-1 extensions. For a topologically transitive system with the
shadowing property, we show that ergodic measures supported on odometers are
dense in the space of invariant measures, and then ergodic measures are generic
in the space of invariant measures. We also show that for every $c\geq 0$ and
$\varepsilon>0$ the collection of ergodic measures (supported on almost 1-1
extensions of odometers) with entropy between $c$ and $c + \varepsilon$ is
dense in the space of invariant measures with entropy at least $c$. Moreover,
if in addition the entropy function is upper semi-continuous, then for every
$c\geq 0$ ergodic measures with entropy $c$ are generic in the space of
invariant measures with entropy at least $c$.


title: Factorization in $SL^\infty$

abstract:
  We show that the non-separable Banach space $SL^\infty$ is primary. This is
achieved by directly solving the infinite dimensional factorization problem in
$SL^\infty$. In particular, we bypass Bourgain's localization method.


title: Ultrafast outflows in ultraluminous X-ray sources

abstract:
  Ultraluminous X-ray sources (ULXs) are bright extragalactic sources with
X-ray luminosities above 10^39 erg/s powered by accretion onto compact objects.
According to the first studies performed with XMM-Newton ULXs seemed to be
excellent candidates to host intermediate-mass black holes (10^2-4 solar
masses). However, in the last years the interpretation of super-Eddington
accretion onto stellar-mass black holes or neutron stars for most ULXs has
gained a strong consensus. One critical missing piece to confirm the
super-Eddington scenario was the direct detection of the massive,
radiatively-driven winds expected as atomic emission/absorption lines in ULX
spectra. The first evidence for winds was found as residuals in the soft X-ray
spectra of ULXs. Most recently we have been able to resolve these residuals
into rest-frame emission and blueshifted (~0.2c) absorption lines arising from
highly ionized gas in the deep high-resolution XMM-Newton spectra of two
ultraluminous X-ray sources. The compact object is therefore surrounded by
powerful ultrafast winds as predicted by models of hyper-Eddington accretion.
Here we discuss the relevance of these discoveries and the importance of
further, deep, XMM-Newton observations of powerful winds in many other
ultraluminous X-ray sources to estimate the energetics of the wind, the
geometry of the system, and the masses of the central accretors.


title:
Critical assessment of von Mises distribution and an infinite series
  ansatz for self-propelled particles

abstract:
  We consider a Vicsek model of self-propelled particles with bounded
confidence, where each particle interacts only with neighbors that have a
similar direction. Depending on parameters, the system exhibits a continuous or
discontinuous polar phase transition from the isotropic phase to a phase with a
preferred direction. In a recent paper [1] the von Mises distribution was
proposed as an ansatz for polar ordering. In the present system the time
evolution of the angular distribution can be solved in Fourier space. We
compare the results of the Fourier analysis with the ones obtained by using the
von Mises distribution ansatz. In the latter case the qualitative behavior of
the system is recovered correctly. However, quantitatively there are serious
deviations. We introduce an extended von Mises distribution ansatz such that a
second term takes care of the next two Fourier modes. With the extended ansatz
we find much better quantitative agreement. As an alternative approach we also
use a Gaussian and a geometric series ansatz in Fourier space. The geometric
series ansatz is analytically handable but fails for very weak noise, the
Gaussian ansatz yields better results but it is not analytically treatable.


title:
TorchCraft: a Library for Machine Learning Research on Real-Time
  Strategy Games

abstract:
  We present TorchCraft, a library that enables deep learning research on
Real-Time Strategy (RTS) games such as StarCraft: Brood War, by making it
easier to control these games from a machine learning framework, here Torch.
This white paper argues for using RTS games as a benchmark for AI research, and
describes the design and components of TorchCraft.


title:
Trap effects and continuum limit of the Hubbard model in the presence of
  a harmonic potential

abstract:
  We give a prescription to perform the continuum limit of the $d$-dimensional
Hubbard model in the presence of a harmonic trap at zero temperature. We
perform the continuum limit at fixed number of particles. In $d\geq3$ the
lattice system of spin-1/2 particles is mapped into a non-interacting
two-component Fermi gas in a harmonic trap. In $d=1$ and $d=2$ the particles
with opposite spin interact via a Dirac delta interaction. We show that the
properties of this continuum limit can be put in correspondence with those
derived applying the Trap-Size scaling (TSS) formalism to the confined Hubbard
model in the so called Dilute Regime (fixed number of particles and weak
confinement). The correspondence in $d=1$ and $d=2$ has been tested comparing
the numerical results obtained for lattice system with those of the continuum
limit in the case of two-particle and in absence of spin-polarization
($N=2$,$N_{\uparrow}=N_{\downarrow}=1$).


title: Bistability vs. Metastability in Driven Dissipative Rydberg Gases

abstract:
  We investigate the possibility of a bistable phase in an open many-body
system. To this end we discuss the microscopic dynamics of a continuously
off-resonantly driven Rydberg lattice gas in the regime of strong decoherence.
Our experimental results reveal a prolongation of the temporal correlations
with respect to the lifetime of a single Rydberg excitation and show strong
evidence for the formation of finite-sized Rydberg excitation clusters in the
steady state. We simulate our data using a simplified and a full many-body
rate-equation model. The results are compatible with the formation of
metastable states associated with a bimodal counting distribution as well as
dynamic hysteresis. A scaling analysis reveals however, that the correlation
times remain finite for all relevant system parameters. This suggest that the
Rydberg aggregate is composed of many small clusters and all correlation
lengths remain finite. This is a strong indication for the absence of a global
bistable phase, previously suggested to exist in this system.


title: Baxter operators and asymptotic representations

abstract:
  We introduce a category $\mathcal O$ of representations of the elliptic
quantum group associated with $\mathfrak{sl}_2$ with well-behaved $q$-character
theory. We derive separation of variables relations for asymptotic
representations in the Grothendieck ring of this category. Baxter $Q$-operators
are obtained as transfer matrices for asymptotic representations and obey
$TQ$-relations as a consequence of the relations in $K_0(\mathcal O)$.


title: The Gaia DR1 Mass-Radius Relation for White Dwarfs

abstract:
  The Gaia Data Release 1 (DR1) sample of white dwarf parallaxes is presented,
including 6 directly observed degenerates and 46 white dwarfs in wide binaries.
This data set is combined with spectroscopic atmospheric parameters to study
the white dwarf mass-radius relationship (MRR). Gaia parallaxes and G
magnitudes are used to derive model atmosphere dependent white dwarf radii,
which can then be compared to the predictions of a theoretical MRR. We find a
good agreement between Gaia DR1 parallaxes, published effective temperatures
(Teff) and surface gravities (log g), and theoretical MRRs. As it was the case
for Hipparcos, the precision of the data does not allow for the
characterisation of hydrogen envelope masses. The uncertainties on the
spectroscopic atmospheric parameters are found to dominate the error budget and
current error estimates for well-known and bright white dwarfs may be slightly
optimistic. With the much larger Gaia DR2 white dwarf sample it will be
possible to explore the MRR over a much wider range of mass, Teff, and spectral
types.


title:
The accumulated persistence function, a new useful functional summary
  statistic for topological data analysis, with a view to brain artery trees
  and spatial point process applications

abstract:
  We start with a simple introduction to topological data analysis where the
most popular tool is called a persistent diagram. Briefly, a persistent diagram
is a multiset of points in the plane describing the persistence of topological
features of a compact set when a scale parameter varies. Since statistical
methods are difficult to apply directly on persistence diagrams, various
alternative functional summary statistics have been suggested, but either they
do not contain the full information of the persistence diagram or they are
two-dimensional functions. We suggest a new functional summary statistic that
is one-dimensional and hence easier to handle, and which under mild conditions
contains the full information of the persistence diagram. Its usefulness is
illustrated in statistical settings concerned with point clouds and brain
artery trees. The appendix includes additional methods and examples, together
with technical details. The R-code used for all examples is available at
http://people.math.aau.dk/~christophe/Rcode.zip.


title:
On the ratio probability of the smallest eigenvalues in the Laguerre
  Unitary Ensemble

abstract:
  We study the probability distribution of the ratio between the second
smallest and smallest eigenvalue in the $n\times n$ Laguerre Unitary Ensemble.
The probability that this ratio is greater than $r>1$ is expressed in terms of
an $n \times n$ Hankel determinant with a perturbed Laguerre weight. The
limiting probability distribution for the ratio as $n\to\infty$ is found as an
integral over $(0,\infty)$ containing two functions $q_{1}(x)$ and $q_{2}(x)$.
These functions satisfy a system of two coupled Painlev\'e V equations, which
are derived from a Lax pair of a Riemann-Hilbert problem. We compute asymptotic
behaviours of these functions as $rx \to 0_{+}$ and $(r-1)x \to \infty$, as
well large $n$ asymptotics for the associated Hankel determinants in several
regimes of $r$ and $x$.


title:
The impact of the revised $^{17}$O$(p,\alpha)^{14}$N reaction rate on
  $^{17}$O stellar abundances and yields

abstract:
  Context. Material processed by the CNO cycle in stellar interiors is enriched
in 17O. When mixing processes from the stellar surface reach these layers, as
occurs when stars become red giants and undergo the first dredge up, the
abundance of 17O increases. Such an occurrence explains the drop of the 16O/17O
observed in RGB stars with mass larger than 1.5 M_\solar. As a consequence, the
interstellar medium is continuously polluted by the wind of evolved stars
enriched in 17O . Aims. Recently, the Laboratory for Underground Nuclear
Astrophysics (LUNA) collaboration released an improved rate of the
17O(p,alpha)14N reaction. In this paper we discuss the impact that the revised
rate has on the 16O/17O ratio at the stellar surface and on 17O stellar yields.
Methods. We computed stellar models of initial mass between 1 and 20 M_\solar
and compared the results obtained by adopting the revised rate of the
17O(p,alpha)14N to those obtained using previous rates. Results. The post-first
dredge up 16O/17O ratios are about 20% larger than previously obtained.
Negligible variations are found in the case of the second and the third dredge
up. In spite of the larger 17O(p,alpha)14N rate, we confirm previous claims
that an extra-mixing process on the red giant branch, commonly invoked to
explain the low carbon isotopic ratio observed in bright low-mass giant stars,
marginally affects the 16O/17O ratio. Possible effects on AGB extra-mixing
episodes are also discussed. As a whole, a substantial reduction of 17O stellar
yields is found. In particular, the net yield of stars with mass ranging
between 2 and 20 M_\solar is 15 to 40% smaller than previously estimated.
Conclusions. The revision of the 17O(p,alpha)14N rate has a major impact on the
interpretation of the 16O/17O observed in evolved giants, in stardust grains
and on the 17O stellar yields.