title: Relaxed Byzantine Vector Consensus

abstract:
  Exact Byzantine consensus problem requires that non-faulty processes reach
agreement on a decision (or output) that is in the convex hull of the inputs at
the non-faulty processes. It is well-known that exact consensus is impossible
in an asynchronous system in presence of faults, and in a synchronous system,
n>=3f+1 is tight on the number of processes to achieve exact Byzantine
consensus with scalar inputs, in presence of up to f Byzantine faulty
processes. Recent work has shown that when the inputs are d-dimensional vectors
of reals, n>=max(3f+1,(d+1)f+1) is tight to achieve exact Byzantine consensus
in synchronous systems, and n>= (d+2)f+1 for approximate Byzantine consensus in
asynchronous systems.
  Due to the dependence of the lower bound on vector dimension d, the number of
processes necessary becomes large when the vector dimension is large. With the
hope of reducing the lower bound on n, we consider two relaxed versions of
Byzantine vector consensus: k-Relaxed Byzantine vector consensus and
(delta,p)-Relaxed Byzantine vector consensus. In k-relaxed consensus, the
validity condition requires that the output must be in the convex hull of
projection of the inputs onto any subset of k-dimensions of the vectors. For
(delta,p)-consensus the validity condition requires that the output must be
within distance delta of the convex hull of the inputs of the non-faulty
processes, where L_p norm is used as the distance metric. For
(delta,p)-consensus, we consider two versions: in one version, delta is a
constant, and in the second version, delta is a function of the inputs
themselves.
  We show that for k-relaxed consensus and (delta,p)-consensus with constant
delta>=0, the bound on n is identical to the bound stated above for the
original vector consensus problem. On the other hand, when delta depends on the
inputs, we show that the bound on n is smaller when d>=3.


title:
System Identification through Online Sparse Gaussian Process Regression
  with Input Noise

abstract:
  There has been a growing interest in using non-parametric regression methods
like Gaussian Process (GP) regression for system identification. GP regression
does traditionally have three important downsides: (1) it is computationally
intensive, (2) it cannot efficiently implement newly obtained measurements
online, and (3) it cannot deal with stochastic (noisy) input points. In this
paper we present an algorithm tackling all these three issues simultaneously.
The resulting Sparse Online Noisy Input GP (SONIG) regression algorithm can
incorporate new noisy measurements in constant runtime. A comparison has shown
that it is more accurate than similar existing regression algorithms. When
applied to non-linear black-box system modeling, its performance is competitive
with existing non-linear ARX models.


title:
Stellar modelling of Spica, a high-mass spectroscopic binary with a beta
  Cep variable primary component

abstract:
  Binary stars provide a valuable test of stellar structure and evolution,
because the masses of the individual stellar components can be derived with
high accuracy and in a model-independent way. In this work, we study Spica, an
eccentric double-lined spectroscopic binary system with a beta Cep type
variable primary component. We use state-of-the-art modelling tools to
determine accurate orbital elements of the binary system and atmospheric
parameters of both stellar components. We interpret the short-period
variability intrinsic to the primary component, detected on top of the orbital
motion both in the photometric and spectroscopic data. The non-LTE based
spectrum analysis reveals two stars of similar atmospheric chemical composition
consistent with the present day cosmic abundance standard defined by
Nieva&Przybilla (2012). The masses and radii of the stars are found to be
11.43+/-1.15 M_sun and 7.21+/-0.75 M_sun, and 7.47+/-0.54 R_sun and 3.74+/-0.53
R_sun for the primary and secondary, respectively. We find the primary
component to pulsate in three independent modes, of which one is identified as
a radial mode, while the two others are found to be non-radial, low degree l
modes. The frequency of one of these modes is an exact multiple of the orbital
frequency, and the l=m=2 mode identification suggests a tidal nature for this
particular mode. We find a very good agreement between the derived dynamical
and evolutionary masses for the Spica system to within the observational errors
of the measured masses. The age of the system is estimated to be 12.5+/-1 Myr.


title:
Large-displacement statistics of the rightmost particle of the
  one-dimensional branching Brownian motion

abstract:
  Consider a one-dimensional branching Brownian motion, and rescale the
coordinate and time so that the rates of branching and diffusion are both equal
to $1$. If $X_1(t)$ is the position of the rightmost particle of the branching
Brownian motion at time $t$, the empirical velocity $c$ of this rightmost
particle is defined as $c=X_1(t)/t$. Using the Fisher-KPP equation, we evaluate
the probability distribution ${\mathcal P(c,t)}$ of this empirical velocity $c$
in the long time $t$ limit for $c > 2$. It was already known that, for a single
seed particle, ${\mathcal P(c,t)} \sim \exp \,[-(c^2/4-1)t]$ up to a prefactor
that can depend on $c$ and $t$. Here we show how to determine this prefactor.
The result can be easily generalized to the case of multiple seed particles and
to branching random walks associated to other traveling wave equations.


title: Swift-XRT 6-year monitoring of the ultraluminous X-ray source M33-X8

abstract:
  The long term evolution of ULX with their spectral and luminosity variations
in time give important clues on the nature of ULX and on the accretion process
that powers them. We report here the results of a Swift-XRT 6-year monitoring
campaign of the closest example of a persistent ULX, M33 X-8, that extends to
16 years the monitoring of this source in the soft X-rays. The luminosity of
this source is a few 10^39 erg/s, marking the faint end of the ULX luminosity
function. We analysed the set of 15 observations collected during the Swift
monitoring. We searched for differences in the spectral parameters at different
observing epochs, adopting several models commonly used to fit the X-ray
spectra of ULX. The source exhibits flux variations of the order of 30%. No
significant spectral variations are observed along the monitoring. The average
0.5-10 keV spectrum can be well described by a thermal model, either in the
form of a slim disk, or as a combination of a Comptonized corona and a standard
accretion disk.


title: Analysis on the Intersection of Pseudoconvex Domains

abstract:
  In this note, we discuss the preservation of certain analytic properties of
the $\overline{\partial}$-Neumann operator, Bergman projection and Hankel
operators on the intersection of pseudoconvex domains.


title: Nontrivial solutions of systems of nonlocal Caputo fractional BVPs

abstract:
  We discuss the existence, non-existence and multiplicity of nontrivial
solutions for systems of Caputo fractional differential equations subject to
nonlocal boundary conditions. Our methodology relies on classical fixed point
index and we make use of recent results by Infante and Pietramala.


title:
Proton radiography to improve proton radiotherapy: Simulation study at
  different proton beam energies

abstract:
  To improve the quality of cancer treatment with protons, a translation of
X-ray Computed Tomography (CT) images into a map of the proton stopping powers
needs to be more accurate. Proton stopping powers determined from CT images
have systematic uncertainties in the calculated proton range in a patient of
typically 3-4\% and even up to 10\% in region containing
bone~\cite{USchneider1995,USchneider1996,WSchneider2000,GCirrone2007,HPaganetti2012,TPlautz2014,GLandry2013,JSchuemann2014}.
As a consequence, part of a tumor may receive no dose, or a very high dose can
be delivered in healthy ti\-ssues and organs at risks~(e.g. brain
stem)~\cite{ACKnopf2013}. A transmission radiograph of high-energy protons
measuring proton stopping powers directly will allow to reduce these
uncertainties, and thus improve the quality of treatment.
  The best way to obtain a sufficiently accurate radiograph is by tracking
individual protons traversing the phantom
(patient)~\cite{GCirrone2007,TPlautz2014,VSipala2013}. In our simulations we
have used an ideal position sensitive detectors measuring a single proton
before and after a phantom, while the residual energy of a proton was detected
by a BaF$_{2}$ crystal. To obtain transmission radiographs, diffe\-rent phantom
materials have been irradiated with a 3x3~cm$^{2}$ scattered proton beam, with
various beam energies. The simulations were done using the Geant4 simulation
package~\cite{SAgostinelli2003}.
  In this study we focus on the simulations of the energy loss radiographs for
various proton beam energies that are clinically available in proton
radiotherapy.


title: On the vanishing of negative homotopy K-theory

abstract:
  We show that the homotopy invariant algebraic K-theory of Weibel vanishes
below the negative of the Krull dimension of a noetherian scheme. This gives
evidence for a conjecture of Weibel about vanishing of negative algebraic
K-groups.


title:
Crossover to the Anomalous Quantum Regime in the Extrinsic Spin Hall
  Effect of Graphene

abstract:
  Recent reports of spin-orbit coupling enhancement in chemically modified
graphene have opened doors to studies of the spin Hall effect with massless
chiral fermions. Here, we theoretically investigate the interaction and
impurity density dependence of the extrinsic spin Hall effect in spin-orbit
coupled graphene. We present a nonperturbative quantum diagrammatic calculation
of the spin Hall response function in the strong-coupling regime that
incorporates skew scattering and anomalous impurity density-independent
contributions on equal footing. The spin Hall conductivity dependence on Fermi
energy and electron-impurity interaction strength reveals the existence of
experimentally accessible regions where anomalous quantum processes dominate.
Our findings suggest that spin-orbit-coupled graphene is an ideal model system
for probing the competition between semiclassical and bona fide quantum
scattering mechanisms underlying the spin Hall effect.


title:
k-Dirac operator and the Cartan-Kahler theorem for weighted differential
  operators

abstract:
  The k-Dirac operator is a differential operator which is natural to geometric
structure of a parabolic type. We will give a set of initial conditions for
this operator. In the proof of the claim we will need to adapt some parts from
the theory of exterior differential systems to the setting of weighted
differential operators.


title:
F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric
  drive shaft

abstract:
  F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in the
mitochondrial membranes and bacterial inner membranes in a process driven by
the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump
protons against the concentration gradient across the membrane. ATPase is
composed of two rotary motors, F0 and F1, which generate the opposing rotation
and compete for control of their shared central gamma-shaft. Here we present a
self-consistent physical model of the F1 motor as a simplified two-state
Brownian ratchet based on the asymmetry of torsional elastic energy of the
coiled-coil gamma-shaft. This stochastic model unifies the physical description
of linear and rotary motors and explains the stepped unidirectional rotation of
the $\gamma$-shaft, in agreement with the `binding-change' ideas of Boyer.
Substituting the model parameters, all independently known from recent
experiments, our model quantitatively reproduces the ATPase operation, e.g. the
`no-load' angular velocity is ca. 400~rad/s anticlockwise at 4 mM ATP, in close
agreement with experiment. Increasing the pmf torque exerted by F0 can slow,
stop and overcome the torque generated by F1, switching from ATP hydrolysis to
synthesis at a very low value of `stall torque'. We discuss the matters of the
motor efficiency, which is very low if calculated from the useful mechanical
work it produces - but is quite high when the `useful outcome' is measured in
the number of H+ pushed against the chemical gradient in the F1 ATP-driven
operation.


title:
The Riesz transform and quantitative rectifiability for general Radon
  measures

abstract:
  In this paper we show that if $\mu$ is a Borel measure in $\mathbb R^{n+1}$
with growth of order $n$, so that the $n$-dimensional Riesz transform $R_\mu$
is bounded in $L^2(\mu)$, and $B\subset\mathbb R^{n+1}$ is a ball with
$\mu(B)\approx r(B)^n$ such that: (a) there is some $n$-plane $L$ passing
through the center of $B$ such that for some $\delta>0$ small enough, it holds
$\int_B \frac{dist(x,L)}{r(B)}\,d\mu(x)\leq \delta\,\mu(B),$ (b) for some
constant $\epsilon>0$ small enough, $\int_B |R_\mu1(x) -
m_{\mu,B}(R_\mu1)|^2\,d\mu(x) \leq \epsilon \,\mu(B)$, where
$m_{\mu,B}(R_\mu1)$ stands for the mean of $R_\mu1$ on $B$ with respect to
$\mu$; then there exists a uniformly $n$-rectifiable subset $\Gamma$, with
$\mu(\Gamma\cap B)\gtrsim \mu(B)$, and so that $\mu|_\Gamma$ is absolutely
continuous with respect to $H^n|_\Gamma$. This result is an essential tool to
solve an old question on a two phase problem for harmonic measure in a
subsequent paper by Azzam, Mourgoglou and Tolsa.


title:
Neutron Zeeman beam-splitting for the investigation of magnetic
  nanostructures

abstract:
  The Zeeman spatial splitting of a neutron beam takes place during a neutron
spin-flip in magnetically non-collinear systems at grazing incidence geometry.
We apply the neutron beam-splitting method for the investigation of
magnetically non-collinear clusters of submicron size in a thin film. The
experimental results are compared with ones obtained by other methods.


title: Two scales in Bose-Einstein correlations

abstract:
  We argue that the secondaries produced in high energy hadron collisions are
emitted by small size sources distributed over a much larger area in impact
parameter space occupied by the interaction amplitude. That is, Bose-Einstein
correlation of two emitted identical particles should be described by a
`two-radii' parametrization ansatz. We discuss the expected energy, charged
multiplicity and transverse momentum of the pair (that is, $\sqrt{s},~N_{\rm
ch}, k_t$) behaviour of both the small and large size components.


title: Gravitational waves from an SMBH binary in M87

abstract:
  In this paper, we study gravitational-wave (GW) emission from a hypothetical
supermassive black-hole (SMBH) binary at the center of M87. The existence of a
SMBH other than that usually identified with the central AGN is a possible
explanation for the observed displacement ($\sim O(1)~{\rm pc}$) between the
AGN and the galactic centroid, and it is reasonable to assume consid- ering the
evolution of SMBHs through galaxy mergers. Because the period of the binary and
the resulting GWs is much longer than the observational time span, we calculate
the variation of the GW amplitude, rather than the amplitude itself. We
investigate the dependence on the orbital elements and the second BH mass
taking the observational constraints into account. The frequency of the GWs is
too low to be detected with the conventional pulsar timing array and we propose
a new method to detect such low-frequency GWs with the distribution func- tion
of pulsar spin-down rates. Although the GWs from a SMBH binary which explains
the observed displacement is extremely hard to be detected even with the new
method, GWs are still a useful way to probe the M87 center.


title:
Observational signatures of past mass-exchange episodes in massive
  binaries: The case of HD 149 404

abstract:
  Mass and momentum exchanges in close massive binaries play an important role
in their evolution, and produce several observational signatures such as
asynchronous rotation and altered chemical compositions, that remain after the
stars detach again. We investigated these effects for the detached massive
O-star binary HD 149404 (O7.5If + ON9.7I, P = 9.81 days), which is thought to
have experienced a past episode of case A Roche-lobe overflow (RLOF). Using
phase-resolved spectroscopy, we performed the disentangling of the optical
spectra of the two stars. The reconstructed primary and secondary spectra were
then analysed with the CMFGEN model atmosphere code to determine stellar
parameters, such as the effective temperatures and surface gravities, and to
constrain the chemical composition of the components. We complemented the
optical study with the study of IUE spectra, which we compare to the synthetic
binary spectra. The properties of the stars were compared to evolutionary
models. We confirmed a strong overabundance in nitrogen ($\left[\rm
N/C\right]\sim150\left[\rm N/C\right]_{\odot}$) for the secondary and a slight
nitrogen overabundance ($\left[\rm N/C\right]\sim5\left[\rm
N/C\right]_{\odot}$) for the primary star. Comparing the two stars, we found
evidence for asynchronous rotation, with a rotational period ratio of $0.50 \pm
0.11$. The hypothesis of a past case A RLOF interaction in HD 149404 is most
plausible to explain its chemical abundances and rotational asynchronicity.
Some of the observed properties, such as the abundance pattern, are clearly a
challenge for current case A binary evolution models, however.


title:
Generalized bent functions - sufficient conditions and related
  constructions

abstract:
  The necessary and sufficient conditions for a class of functions
$f:\mathbb{Z}_2^n \rightarrow \mathbb{Z}_q$, where $q \geq 2$ is an even
positive integer, have been recently identified for $q=4$ and $q=8$. In this
article we give an alternative characterization of the generalized
Walsh-Hadamard transform in terms of the Walsh spectra of the component Boolean
functions of $f$, which then allows us to derive sufficient conditions that $f$
is generalized bent for any even $q$. The case when $q$ is not a power of two,
which has not been addressed previously, is treated separately and a suitable
representation in terms of the component functions is employed. Consequently,
the derived results lead to generic construction methods of this class of
functions. The main remaining task, which is not answered in this article, is
whether the sufficient conditions are also necessary. There are some
indications that this might be true which is also formally confirmed for
generalized bent functions that belong to the class of generalized
Maiorana-McFarland functions (GMMF), but still we were unable to completely
specify (in terms of necessity) gbent conditions.


abstract:
  Two fields are Witt equivalent if their Witt rings of symmetric bilinear
forms are isomorphic. Witt equivalent fields can be understood to be fields
having the same quadratic form theory. The behavior of finite fields, local
fields, global fields, as well as function fields of curves defined over
archimedean local fields under Witt equivalence is well-understood. Numbers of
classes of Witt equivalent fields with finite numbers of square classes are
also known in some cases. Witt equivalence of general function fields over
global fields was studied in the earlier work [13] by the authors, and applied
to study Witt equivalence of function fields of curves over global fields. In
this paper we extend these results to local case, i.e. we discuss Witt
equivalence of function fields of curves over local fields. As an application,
we show that, modulo some additional assumptions, Witt equivalence of two such
function fields implies Witt equivalence of underlying local fields.


title: The F-pure threshold of quasi-homogeneous polynomials

abstract:
  Inspired by the work of Bhatt and Singh (see: arXiv:1307.1171) we compute the
$F$-pure threshold of quasi-homogeneous polynomials. We first consider the case
of a curve given by a quasi-homogeneous polynomial $f$ in three variables
$x,y,z$ of degree equal to the degree of $xyz$ and then we proceed with the
general case of a Calabi-Yau hypersurface, i.e. a hypersurface given by a
quasi-homogeneous polynomial $f$ in $n+1$ variables $x_0, \ldots, x_n$ of
degree equal to the degree of $x_0 \cdots x_n$.


title: High--cadence observations of spicular-type events on the Sun

abstract:
  Chromospheric observations taken at high cadence and high spatial resolution
show a range of spicule like features, including Type I, Type II (as well as
RBEs and RREs) and those which seem to appear within a few seconds, which if
interpreted as flows would imply mass flow velocities in excess of 1000 km/s.
This article seeks to quantify and study rapidly appearing spicular type
events. We also compare the MOMFBD and speckle reconstruction techniques in
order to understand if such spicules are more favourably observed using a
particular technique. We use spectral imaging observations taken with the CRISP
on the Swedish 1 m Solar Telescope. Data was sampled at multiple positions
within the Halpha line profile for both an ondisk and limb location. The data
is host to numerous rapidly appearing features which are observed at different
locations within the Halpha line profile. The feature's durations vary between
10 and 20 s and lengths around 3500 km. Sometimes, a time delay in their
appearance between the blue and red wings of 3 and 5 s is evident, whereas
sometimes they are near simultaneous. In some instances features are observed
to fade and then re emerge at the same location several tens of seconds later.
We provide the first statistical analysis of these spicules and suggest that
these observations can be interpreted as the LOS movement of highly dynamic
spicules moving in and out of the narrow 60 mA transmission filter used to
observe in different parts of the Halpha line profile. The LOS velocity
component of the observed fast chromospheric features, manifested as Doppler
shifts, are responsible for their appearance in the red and blue wings of
Halpha line. Additional work involving data at other wavelengths is required to
investigate the nature of their possible wavelike activity.


title:
Model selection via Bayesian information capacity designs for
  generalised linear models

abstract:
  The first investigation is made of designs for screening experiments where
the response variable is approximated by a generalised linear model. A Bayesian
information capacity criterion is defined for the selection of designs that are
robust to the form of the linear predictor. For binomial data and logistic
regression, the effectiveness of these designs for screening is assessed
through simulation studies using all-subsets regression and model selection via
maximum penalised likelihood and a generalised information criterion. For
Poisson data and log-linear regression, similar assessments are made using
maximum likelihood and the Akaike information criterion for minimally-supported
designs that are constructed analytically. The results show that effective
screening, that is, high power with moderate type I error rate and false
discovery rate, can be achieved through suitable choices for the number of
design support points and experiment size. Logistic regression is shown to
present a more challenging problem than log-linear regression. Some areas for
future work are also indicated.


title: An alternative model for the origin of gaps in circumstellar disks

abstract:
  Motivated by recent observational and numerical studies suggesting that
collapsing protostellar cores may be replenished from the local environment, we
explore the evolution of protostellar cores submerged in the external
counter-rotating environment. These models predict the formation of
counter-rotating disks with a deep gap in the gas surface density separating
the inner disk (corotating with the star) and the outer counter-rotating disk.
The properties of these gaps are compared to those of planet-bearing gaps that
form in disks hosting giant planets. We employ numerical hydrodynamics
simulations of collapsing cores that are replenished from the local
counter-rotating environment, as well as numerical hydrodynamic simulations of
isolated disks hosting giant planets, to derive the properties of the gaps that
form in both cases. Our numerical simulations demonstrate that counter-rotating
disks can form for a wide range of mass and angular momentum available in the
local environment. The gap that separates both disks has a depletion factor
smaller than 1%, can be located at a distance from ten to over a hundred AU
from the star, and can propagate inward with velocity ranging from 1 AU/Myr to
>100 AU/Myr. Unlike our previous conclusion, the gap can therefore be a
long-lived phenomenon, comparable in some cases to the lifetime of the disk
itself. For a proper choice of the planetary mass, the viscous \alpha-parameter
and the disk mass, the planet-bearing gaps and the gaps in counter-rotating
disks may show a remarkable similarity in the gas density profile and depletion
factor, which may complicate their observational differentiation.


title:
Space-time smoothing of complex survey data: Small area estimation for
  child mortality

abstract:
  Many people living in low- and middle-income countries are not covered by
civil registration and vital statistics systems. Consequently, a wide variety
of other types of data, including many household sample surveys, are used to
estimate health and population indicators. In this paper we combine data from
sample surveys and demographic surveillance systems to produce small area
estimates of child mortality through time. Small area estimates are necessary
to understand geographical heterogeneity in health indicators when
full-coverage vital statistics are not available. For this endeavor
spatio-temporal smoothing is beneficial to alleviate problems of data sparsity.
The use of conventional hierarchical models requires careful thought since the
survey weights may need to be considered to alleviate bias due to nonrandom
sampling and nonresponse. The application that motivated this work is an
estimation of child mortality rates in five-year time intervals in regions of
Tanzania. Data come from Demographic and Health Surveys conducted over the
period 1991-2010 and two demographic surveillance system sites. We derive a
variance estimator of under five years child mortality that accounts for the
complex survey weighting. For our application, the hierarchical models we
consider include random effects for area, time and survey and we compare models
using a variety of measures including the conditional predictive ordinate
(CPO). The method we propose is implemented via the fast and accurate
integrated nested Laplace approximation (INLA).


title:
On the validity of tidal turbine array configurations obtained from
  steady-state adjoint optimisation

abstract:
  Extracting the optimal amount of power from an array of tidal turbines
requires an intricate understanding of tidal dynamics and the effects of
turbine placement on the local and regional scale flow. Numerical models have
contributed significantly towards this understanding, and more recently,
adjoint-based modelling has been employed to optimise the positioning of the
turbines in an array in an automated way and improve on simple, regular
man-made configurations. Adjoint-based optimisation of high-resolution and
ideally 3D transient models is generally a very computationally expensive
problem. As a result, existing work on the adjoint optimisation of tidal
turbine placement has been mostly limited to steady-state simulations in which
very high, non-physical values of the background viscosity are required to
ensure that a steady-state solution exists. However, such compromises may
affect the reliability of the modelled turbines, their wakes and interactions,
and thus bring into question the validity of the computed optimal turbine
positions. This work considers a suite of idealised simulations of flow past
tidal turbine arrays in a 2D channel. It compares four regular array
configurations, detailed by Divett et al. (2013), with the configuration found
through adjoint optimisation in a steady-state, high-viscosity setup. The
optimised configuration produces considerably more power. The same
configurations are then used to produce a suite of transient simulations that
do not use constant high-viscosity, and instead use large eddy simulation (LES)
to parameterise the resulting turbulent structures. It is shown that the LES
simulations produce less power than that predicted by the constant
high-viscosity runs. Nevertheless, they still follow the same trends in the
power curve throughout time, with optimised layouts continuing to perform
significantly better than simplified configurations.


title: A Stokes drift approximation based on the Phillips spectrum

abstract:
  A new approximation to the Stokes drift velocity profile based on the exact
solution for the Phillips spectrum is explored. The profile is compared with
the monochromatic profile and the recently proposed exponential integral
profile. ERA-Interim spectra and spectra from a wave buoy in the central North
Sea are used to investigate the behaviour of the profile. It is found that the
new profile has a much stronger gradient near the surface and lower normalized
deviation from the profile computed from the spectra. Based on estimates from
two open-ocean locations, an average value has been estimated for a key
parameter of the profile. Given this parameter, the profile can be computed
from the same two parameters as the monochromatic profile, namely the transport
and the surface Stokes drift velocity.


title:
Generation of photon-plasmon quantum states in nonlinear hyperbolic
  metamaterials

abstract:
  We develop a general theoretical framework of integrated paired
photon-plasmon generation through spontaneous wave mixing in nonlinear
plasmonic and metamaterial nanostructures, rigorously accounting for material
dispersion and losses in quantum regime through the electromagnetic Green
function. We identify photon-plasmon correlations in layered metal-dielectric
structures with 70% internal heralding quantum efficiency, and reveal novel
mechanism of broadband generation enhancement due to topological transition in
hyperbolic metamaterials.


title: On the renormalization of operator products: the scalar gluonic case

abstract:
  In this paper we study the renormalization of the product of two operators
$O_1=-\frac{1}{4} G^{\mu \nu}G_{\mu \nu}$ in QCD. An insertion of two such
operators $O_1(x)O_1(0)$ into a Greens function produces divergent contact
terms for $x\rightarrow 0$.
  In the course of the computation of the operator product expansion (OPE) of
the correlator of two such operators $i\int\!\mathrm{d}^4x\,e^{iqx}
T\{\,O_1(x)O_1(0)\}$ to three-loop order we discovered that divergent contact
terms remain not only in the leading Wilson coefficient $C_0$, which is just
the VEV of the correlator, but also in the Wilson coefficient $C_1$ in front of
$O_1$. As this correlator plays an important role for example in QCD sum rules
a full understanding of its renormalization is desireable.
  This work explains how the divergences encountered in higher orders of an OPE
of this correlator should be absorbed in counterterms and derives an additive
renormalization constant for $C_1$ from first principles and to all orders in
perturnbation theory. The method to derive the renormalization of this operator
product is an extension of the ideas of a paper by Spiridonov and can be
generalized to other cases.


title:
Tight bound on the classical value of generalized
  Clauser-Horne-Shimony-Holt games

abstract:
  Non-local games are an important part of quantum information processing.
Recently there has been an increased interest in generalizing non-local games
beyond the basic setup by considering games with multiple parties and/or with
large alphabet inputs and outputs. In this paper we consider another
interesting generalization -- games with non-uniform inputs. Here we derive a
tight upper bound for the classical winning probability for a specific family
of non-local games with non-uniform input distribution, known as
$\mathrm{CHSH}_q(p)$ which was introduced recently in the context of
relativistic bit-commitment protocols by [Chakraborty et. al., PRL 115, 250501,
2015].


title:
Nonradial modes in RR Lyrae stars from the OGLE Collection of Variable
  Stars

abstract:
  The Optical Gravitational Lensing Experiment (OGLE) is a great source of
top-quality photometry of classical pulsators. Collection of variable stars
from the fourth part of the project contains more than 38 000 RR Lyrae stars.
These stars pulsate mostly in the radial fundamental mode (RRab), in radial
first overtone (RRc) or in both modes simultaneously (RRd). Analysis of the
OGLE data allowed to detect additional non-radial modes in RRc and in RRd
stars. We have found more than 260 double-mode stars with characteristic period
ratio of the additional (shorter) period to first overtone period around 0.61,
increasing the number of known stars of this type by factor of 10. Stars from
the OGLE sample form three nearly parallel sequences in the Petersen diagram.
Some stars show more than one non-radial mode simultaneously. These modes
belong to different sequences.


title:
Lymphangiogenesis and carcinoma in the uterine cervix: Joint and
  hierarchical models for random cluster sizes and continuous outcomes

abstract:
  Although the lymphatic system is clearly linked to the metastasis of most
human carcinomas, the mechanisms by which lymphangiogenesis occurs in response
to the presence of carcinoma remain unclear. Hierarchical models are presented
to investigate the properties of lymphatic vessel production in 2997 fields
taken from 20 individuals with invasive carcinoma, 21 individuals with cervical
intraepithelial neoplasia and 21 controls. Such data demonstrate a high degree
of correlation within tumour samples from the same individual. Joint
hierarchical models utilising shared random effects are discussed and fitted in
a Bayesian framework to allow for the correlation between two key outcome
measures: a random cluster size (the number of lymphatic vessels in a tissue
sample) and a continuous outcome (vessel size). Results show that invasive
carcinoma samples are associated with increased production of smaller and more
irregularly-shaped lymphatic vessels and suggest a mechanistic link between
carcinoma of the cervix and lymphangiogenesis.


title: Gradient flow structure for McKean-Vlasov equations on discrete spaces

abstract:
  In this work, we show that a family of non-linear mean-field equations on
discrete spaces can be viewed as a gradient flow of a natural free energy
functional with respect to a certain metric structure we make explicit. We also
prove that this gradient flow structure arises as the limit of the gradient
flow structures of a natural sequence of N-particle dynamics, as N goes to
infinity.


title:
Chaos in Fractionally Integrated Generalized Autoregressive Conditional
  Heteroskedastic Processes

abstract:
  Fractionally integrated generalized autoregressive conditional
heteroskedasticity (FIGARCH) arises in modeling of financial time series.
FIGARCH is essentially governed by a system of nonlinear stochastic difference
equations ${u_t}$ = ${z_t}$ $(1-\sum\limits_{j=1}^q \beta_j L^j)\sigma_{t}^2 =
\omega+(1-\sum\limits_{j=1}^q \beta_j L^j - (\sum\limits_{k=1}^p \varphi_k L^k)
(1-L)^d) u_t^2$, where $\omega\in$ R, and $\beta_j\in$ R are constant
parameters, $\{u_t\}_{{t\in}^+}$ and $\{\sigma_t\}_{{t\in}^+}$ are the discrete
time real valued stochastic processes which represent FIGARCH (p,d,q) and
stochastic volatility, respectively. Moreover, L is the backward shift
operator, i.e. $L^d u_t \equiv u_{t-d}$ (d is the fractional differencing
parameter 0$<$d$<$1).
  In this work, we have studied the chaoticity properties of FIGARCH (p,d,q)
processes by computing mutual information, correlation dimensions, FNNs (False
Nearest Neighbour), the Lyapunov exponents, and for both the stochastic
difference equation given above and for the financial time series. We have
observed that maximal Lyapunov exponents are negative, therefore, it can be
suggested that FIGARCH (p,d,q) is not deterministic chaotic process.


title: Precise Predictions for the Higgs-Boson Masses in the NMSSM

abstract:
  The particle discovered in the Higgs boson searches at the LHC with a mass of
about 125 GeV can be identified with one of the neutral Higgs bosons of the
Next-to-Minimal Supersymmetric Standard Model (NMSSM). We calculate predictions
for the Higgs-boson masses in the NMSSM using the Feynman-diagrammatic
approach. The predictions are based on the full NMSSM one-loop corrections
supplemented with the dominant and sub-dominant two-loop corrections within the
Minimal Supersymmetric Standard Model (MSSM). These include contributions at
$\mathcal{O}{\left(\alpha_t \alpha_s, \alpha_b \alpha_s,
\alpha_t^2,\alpha_t\alpha_b\right)}$, as well as a resummation of leading and
subleading logarithms from the top/scalar top sector. Taking these corrections
into account in the prediction for the mass of the Higgs boson in the NMSSM
that is identified with the observed signal is crucial in order to reach a
precision at a similar level as in the MSSM. The quality of the approximation
made at the two-loop level is analysed on the basis of the full one-loop
result, with a particular focus on the prediction for the Standard Model-like
Higgs boson that is associated with the observed signal. The obtained results
will be used as a basis for the extension of the code FeynHiggs to the NMSSM.


title:
A method to achieve rapid localised deep heating in a laser irradiated
  solid density target

abstract:
  Rapid heating of small buried regions by laser generated fast electrons may
be useful for applications such as XUV radiation sources or as drivers for
shock experiments. In non-structured targets the heating profile possesses a
global maximum near the front surface. This paper presents a new target design
that uses resistive guiding to concentrate the fast electron current density at
a finite depth inside the target. The choice of geometry uses principles of
non-imaging optics. A global temperature maximum at depths up to 50{\mu}m into
the target is achieved. Although theoretical calculations suggest that small
source sizes should perform better than large ones, simulations show that a
large angular spread at high intensities results in significant losses of the
fast electrons to the sides. A systematic parameter scan suggests an optimal
laser intensity. A ratio of 1.6 is demonstrated between the maximum ion
temperature and the ion temperature at the front surface.


title: On the geometric properties of the Bessel-Struve kernel function

abstract:
  This paper introduce the Bessel-Struve kernel functions $\mathcal{B}_\nu$
defined on the unit disk in the complex plane. We studies the
close-to-convexity of $\mathcal{B}_\nu$ with respect to several starlike
functions. Sufficient condition on $\nu$ for which the function
$z\mathcal{B}_\nu$ is starlike is given.


title:
Derivation and Analysis of Lattice Boltzmann Schemes for the Linearized
  Euler Equations

abstract:
  We derive Lattice Boltzmann (LBM) schemes to solve the Linearized Euler
Equations in 1D, 2D, and 3D with the future goal of coupling them to an LBM
scheme for Navier Stokes Equations and an Finite Volume scheme for Linearized
Euler Equations. The derivation uses the analytical Maxwellian in a BGK model.
In this way, we are able to obtain second-order schemes. In addition, we
perform an $L^2$-stability analysis. Numerical results validate the approach.


title:
Output squeezed radiation from dispersive ultrastrong light-matter
  coupling

abstract:
  We investigate the output generation of squeezed radiation of a cavity photon
mode coupled to another off-resonant bosonic excitation. By modulating in time
their linear interaction, we predict high degree of output squeezing when the
dispersive ultrastrong coupling regime is achieved, i.e., when the interaction
rate becomes comparable to the frequency of the lowest energy mode. Our work
paves the way to squeezed light generation in frequency domains where the
ultrastrong coupling is obtained, e.g., solid-state resonators in the GHz, THz
and mid-IR spectral range.


title:
An Apodized Kepler Periodogram for Separating Planetary and Stellar
  Activity Signals

abstract:
  A new apodized Keplerian (AK) model is proposed for the analysis of precision
radial velocity (RV) data to model both planetary and stellar activity (SA)
induced RV signals. A symmetrical Gaussian apodization function with unknown
width and center can distinguish planetary signals from SA signals on the basis
of the span of the apodization window. The general model for $m$ apodized
Keplerian signals includes a linear regression term between RV and the stellar
activity diagnostic $\log(R'hk)$, as well as an extra Gaussian noise term with
unknown standard deviation. The model parameters are explored using a Bayesian
fusion MCMC code. A differential version of the Generalized Lomb-Scargle
periodogram that employs a control diagnostic provides an additional way of
distinguishing SA signals and helps guide the choice of new periods. Results
are reported for a recent international RV blind challenge which included
multiple state of the art simulated data sets supported by a variety of stellar
activity diagnostics. In the current implementation, the AK method achieved a
reduction in SA noise by a factor of approximately 6. Final parameter estimates
for the planetary candidates are derived from fits that include AK signals to
model the SA components and simple Keplerians to model the planetary
candidates. Preliminary results are also reported for AK models augmented by a
moving average component that allows for correlations in the residuals.


title:
A note on incompressibility of relativistic fluids and the instantaneity
  of their pressures

abstract:
  We introduce a natural notion of incompressibility for fluids governed by the
relativistic Euler equations on a fixed background spacetime, and show that the
resulting equations reduce to the incompressible Euler equations in the
classical limit as $c\rightarrow \infty$. As our main result, we prove that the
fluid pressure of solutions of these incompressible "relativistic" Euler
equations satisfies an elliptic equation on each of the hypersurfaces
orthogonal to the fluid four-velocity, which indicates infinite speed of
propagation.


title: Optical vibrations in alkali halide crystals

abstract:
  We consider long-wave phonon-polaritons and longitudinal optical phonons in
alkali-halide ionic crystals. The model of point charges that are polarized in
the self-consistent electromagnetic field in a dielectric environment is used.
The standard dispersion laws for both branches of phonon-polaritons and
longitudinal optical phonons are obtained. The transversal optical phonon
frequency is found from the electrostatic equilibrium condition. It is proved
by comparison with tabular data that the found frequency coincides with the ion
plasma frequency multiplied on the relation
$\sqrt{(\varepsilon_{\infty}+2)/(3(\varepsilon_0-\varepsilon_\infty))},$ where
$\varepsilon_{\infty}$ and $\varepsilon_0$ are the high-frequency dielectric
constant and the static one respectively.


title:
Giant Plasmon Instability in Dual-Grating-Gate Graphene Field-Effect
  Transistor

abstract:
  We study instability of plasmons in a dual-grating-gate graphene field-effect
transistor induced by dc current injection using self-consistent simulations
with the Boltzmann equation. With only the acoustic-phonon-limited electron
scattering, it is demonstrated that a total growth rate of the plasmon
instability, with the terahertz/mid-infrared range of the frequency, can exceed
$4\times10^{12}$ s$^{-1}$ at room temperature, which is an order of magnitude
larger than in two-dimensional electron gases based on usual semiconductors. By
Comparing the simulation results with existing theory, it is revealed that the
giant total growth rate originates from simulataneous occurence of the
so-called Dyakonov-Shur and Ryzhii-Satou-Shur instabilities.


title: Construction of uniformly bounded periodic continued fractions

abstract:
  We build, for real quadratic fields, infinitely many periodic continuous
fractions uniformly bounded, with a seemingly better bound than the known ones.
We do that using continuous fraction expansions with the same shape as those of
real numbers sqrt(n) + n. It allows us to obtain that there exist infinitely
many quadratic fields containing infinitely many continuous fraction expansions
formed only by integers 1 and 2. We also prove that a conjecture of Zaremba
implies a conjecture of McMullen, building periodic continuous fractions from
continued fraction expansions of rational numbers.


title:
Mirror symmetry, Tyurin degenerations and fibrations on Calabi-Yau
  manifolds

abstract:
  We investigate a potential relationship between mirror symmetry for
Calabi-Yau manifolds and the mirror duality between quasi-Fano varieties and
Landau-Ginzburg models. More precisely, we show that if a Calabi-Yau admits a
so-called Tyurin degeneration to a union of two Fano varieties, then one should
be able to construct a mirror to that Calabi-Yau by gluing together the
Landau-Ginzburg models of those two Fano varieties. We provide evidence for
this correspondence in a number of different settings, including
Batyrev-Borisov mirror symmetry for K3 surfaces and Calabi-Yau threefolds,
Dolgachev-Nikulin mirror symmetry for K3 surfaces, and an explicit family of
threefolds that are not realized as complete intersections in toric varieties.


title: A Two-Phase Algorithm for Bin Stretching with Stretching Factor 1.5

abstract:
  Online Bin Stretching is a semi-online variant of bin packing in which the
algorithm has to use the same number of bins as an optimal packing, but is
allowed to slightly overpack the bins. The goal is to minimize the amount of
overpacking, i.e., the maximum size packed into any bin.
  We give an algorithm for Online Bin Stretching with a stretching factor of
1.5 for any number of bins. We build on previous algorithms and use a two-phase
approach. However, our analysis is technically more complicated and uses
amortization over the bins with the help of two weight functions.


title:
Channel Pre-Inversion and max-SINR Vector Perturbation for Large-Scale
  Broadcast Channels

abstract:
  We study channel pre-inversion and vector perturbation (VP) schemes for
large-scale broadcast channels, wherein a transmitter has $M$ transmit antennas
and is transmitting to $K$ single-antenna non-cooperating receivers. We provide
results which predict the capacity of MMSE pre-inversion as
$K\rightarrow\infty$. We construct a new VP strategy, max-SINR vector
perturbation (MSVP), which maximizes a sharp estimate of the
signal-to-interference-plus-noise ratio. We provide results which predict the
performance of MSVP and demonstrate that MSVP outperforms other VP methods.
Lastly, we combine MSVP with the low-complexity Sorted QR Precoding method to
show that MSVP has the potential to efficiently deliver data to a very large
number of users at close to channel capacity.


title: Lorentz Constraints on Massive Three-Point Amplitudes

abstract:
  Using the helicity-spinor language we explore the non-perturbative
constraints that Lorentz symmetry imposes on three-point amplitudes where the
asymptotic states can be massive. As it is well known, in the case of only
massless states the three-point amplitude is fixed up to a coupling constant by
these constraints plus some physical requirements. We find that a similar
statement can be made when some of the particles have mass. We derive the
generic functional form of the three-point amplitude by virtue of Lorentz
symmetry, which displays several functional structures accompanied by arbitrary
constants. These constants can be related to the coupling constants of the
theory, but in an unambiguous fashion only in the case of one massive particle.
Constraints on these constants are obtained by imposing that in the UV limit
the massive amplitude matches the massless one. In particular, there is a
certain Lorentz frame, which corresponds to projecting all the massive momenta
along the same null momentum, where the three-point massive amplitude is fully
fixed, and has a universal form.


title:
Astronomical Observing Conditions at Xinglong Observatory from 2007 to
  2014

abstract:
  Xinglong Observatory of the National Astronomical Observatories, Chinese
Academy of Sciences (NAOC), is one of the major optical observatories in China,
which hosts nine optical telescopes including the Large Sky Area Multi-Object
Fiber Spectroscopic Telescope (LAMOST) and the 2.16 m reflector. Scientific
research from these telescopes is focused on stars, galaxies, and exoplanets
using multicolor photometry and spectroscopic observations. Therefore, it is
important to provide the observing conditions of the site, in detail, to the
astronomers for an efficient use of these facilities. In this article, we
present the characterization of observing conditions at Xinglong Observatory
based on the monitoring of meteorology, seeing and sky brightness during the
period from 2007 to 2014. Results suggest that Xinglong Observatory is still a
good site for astronomical observations. Our analysis of the observing
conditions at Xinglong Observatory can be used as a reference to the observers
on targets selection, observing strategy, and telescope operation.


title: A geometric approach to alternating $k$-linear forms

abstract:
  Given an $n$-dimensional vector space $V$ over a field $\mathbb K$, let
$2\leq k < n$. There is a natural correspondence between the alternating
$k$-linear forms $\varphi$ of $V$ and the linear functionals $f$ of
$\bigwedge^kV$. Let $\varepsilon_k:{\mathcal G}_k(V)\rightarrow
{\mathrm{PG}}(\bigwedge^kV)$ be the Plucker embedding of the $k$-Grassmannian
${\mathcal G}_k(V)$ of $V$. Then
$\varepsilon_k^{-1}(\ker(f)\cap\varepsilon_k(\mathcal{G}_k(V)))$ is a
hyperplane of the point-line geometry ${\mathcal G}_k(V)$. All hyperplanes of
${\mathcal G}_k(V)$ can be obtained in this way. For a hyperplane $H$ of
${\mathcal G}_k(V)$, let $R^\uparrow(H)$ be the subspace of ${\mathcal
G}_{k-1}(V)$ formed by the $(k-1)$-subspaces $A\subset V$ such that $H$
contains all $k$-subspaces that contain $A$. In other words, if $\varphi$ is
the (unique modulo a scalar) alternating $k$-linear form defining $H$, then the
elements of $R^\uparrow(H)$ are the $(k-1)$-subspaces $A = \langle a_1,\ldots,
a_{k-1}\rangle$ of $V$ such that $\varphi(a_1,\ldots, a_{k-1},x) = 0$ for all
$x\in V$. When $n-k$ is even it might be that $R^\uparrow(H) = \emptyset$. When
$n-k$ is odd, then $R^\uparrow(H) \neq \emptyset$, since every $(k-2)$-subspace
of $V$ is contained in at least one member of $R^\uparrow(H)$. If every
$(k-2)$-subspace of $V$ is contained in precisely one member of $R^\uparrow(H)$
we say that $R^\uparrow(H)$ is spread-like. In this paper we obtain some
results on $R^\uparrow(H)$ which answer some open questions from the literature
and suggest the conjecture that, if $n-k$ is even and at least $4$, then
$R^\uparrow(H) \neq \emptyset$ but for one exception with ${\mathbb
K}\leq{\mathbb R}$ and $(n,k) = (7,3)$, while if $n-k$ is odd and at least $5$
then $R^\uparrow(H)$ is never spread-like.


title:
Densifying the sparse cloud SimSaaS: The need of a synergy among
  agent-directed simulation, SimSaaS and HLA

abstract:
  Modelling & Simulation (M&S) is broadly used in real scenarios where making
physical modifications could be highly expensive. With the so-called Simulation
Software-as-a-Service (SimSaaS), researchers could take advantage of the huge
amount of resource that cloud computing provides. Even so, studying and
analysing a problem through simulation may need several simulation tools, hence
raising interoperability issues. Having this in mind, IEEE developed a standard
for interoperability among simulators named High Level Architecture (HLA).
Moreover, the multi-agent system approach has become recognised as a convenient
approach for modelling and simulating complex systems. Despite all the recent
works and acceptance of these technologies, there is still a great lack of work
regarding synergies among them. This paper shows by means of a literature
review this lack of work or, in other words, the sparse Cloud SimSaaS. The
literature review and the resulting taxonomy are the main contributions of this
paper, as they provide a research agenda illustrating future research
opportunities and trends.


title:
Measurement-driven Quality Assessment of Nonlinear Systems by
  Exponential Replacement

abstract:
  We discuss the problem how to determine the quality of a nonlinear system
with respect to a measurement task. Due to amplification, filtering,
quantization and internal noise sources physical measurement equipment in
general exhibits a nonlinear and random input-to-output behaviour. This usually
makes it impossible to accurately describe the underlying statistical system
model. When the individual operations are all known and deterministic, one can
resort to approximations of the input-to-output function. The problem becomes
challenging when the processing chain is not exactly known or contains
nonlinear random effects. Then one has to approximate the output distribution
in an empirical way. Here we show that by measuring the first two sample
moments of an arbitrary set of output transformations in a calibrated setup,
the output distribution of the actual system can be approximated by an
equivalent exponential family distribution. This method has the property that
the resulting approximation of the statistical system model is guaranteed to be
pessimistic in an estimation theoretic sense. We show this by proving that an
equivalent exponential family distribution in general exhibits a lower Fisher
information measure than the original system model. With various examples and a
model matching step we demonstrate how this estimation theoretic aspect can be
exploited in practice in order to obtain a conservative measurement-driven
quality assessment method for nonlinear measurement systems.


title: Improving the convergence of reversible samplers

abstract:
  In Monte-Carlo methods the Markov processes used to sample a given target
distribution usually satisfy detailed balance, i.e. they are time-reversible.
However, relatively recent results have demonstrated that appropriate
reversible and irreversible perturbations can accelerate convergence to
equilibrium. In this paper we present some general design principles which
apply to general Markov processes. Working with the generator of Markov
processes, we prove that for some of the most commonly used performance
criteria, i.e., spectral gap, asymptotic variance and large deviation
functionals, sampling is improved for appropriate reversible and irreversible
perturbations of some initially given reversible sampler. Moreover we provide
specific constructions for such reversible and irreversible perturbations for
various commonly used Markov processes, such as Markov chains and diffusions.
In the case of diffusions, we make the discussion more specific using the large
deviations rate function as a measure of performance.


title: Applications of vortex gas models to tornadogenesis and maintenance

abstract:
  Processes related to the production of vorticity in the forward and rear
flank downdrafts and their interaction with the boundary layer are thought to
play a role in tornadogenesis. We argue that an inverse energy cascade is a
plausible mechanism for tornadogenesis and tornado maintenance and provide
supporting evidence which is both numerical and observational. We apply a
three-dimensional vortex gas model to supercritical vortices produced at the
surface boundary layer possibly due to interactions of vortices brought to the
surface by the rear flank downdraft and also to those related to the forward
flank downdraft. Two-dimensional and three-dimensional vortex gas models are
discussed, and the three-dimensional vortex gas model of Chorin, developed
further by Flandoli and Gubinelli, is proposed as a model for intense small-
scale subvortices found in tornadoes and in recent numerical studies by Orf et
al. In this paper, the smaller scales are represented by intense, supercritical
vortices, which transfer energy to the larger-scale tornadic flows (inverse
energy cascade). We address the formation of these vortices as a result of the
interaction of the flow with the surface and a boundary layer.


title: Black Hole Horizons and Bose-Einstein Condensation

abstract:
  Consider a particle sitting at a fixed position outside of a stable black
hole. If the system is heated up, the black hole horizon grows and there should
exist a critical temperature above which the particle enters the black hole
interior. We solve a simple model describing exactly this situation: a large N
matrix quantum mechanics modeling a fixed D-particle in a black hole
background. We show that indeed a striking phenomenon occurs: above some
critical temperature, there is a non-perturbative Bose-Einstein condensation of
massless strings. The transition, even though precisely defined by the presence
of the condensate, cannot be sharply detected by measurements made in a finite
amount of time. The order parameter is fundamentally non-local in time and
corresponds to infinite-time correlations.


title:
Physical and mathematical modeling in experimental papers: achieving
  robustness of mathematical modeling studies

abstract:
  Development of several alternative mathematical models for the biological
system in question and discrimination between such models using experimental
data is the best way to robust conclusions. Models which challenge existing
theories are more valuable than models which support such theories.


title: Grover Walks on a Line with Absorbing Boundaries

abstract:
  In this paper, we study Grover walks on a line with one and two absorbing
boundaries. In particular, we present some results for the absorbing
probabilities both in a semi-finite and finite line. Analytical expressions for
these absorbing probabilities are presented by using the combinatorial
approach. These results are perfectly matched with numerical simulations. We
show that the behavior of Grover walks on a line with absorbing boundaries is
strikingly different from that of classical walks and that of Hadamard walks.


title: Space-Time Index Modulation

abstract:
  In this paper, we present a new multi-antenna modulation scheme, termed as
{\em space-time index modulation (STIM)}. In STIM, information bits are
conveyed through antenna indexing in the spatial domain, slot indexing in the
time domain, and $M$-ary modulation symbols. A time slot in a given frame can
be used or unused, and the choice of the slots used for transmission conveys
slot index bits. In addition, antenna index bits are conveyed in every used
time slot by activating one among the available antennas. $M$-ary symbols are
sent on the active antenna in a used time slot. We study STIM in a
cyclic-prefixed single-carrier (CPSC) system in frequency-selective fading
channels. It is shown that, for the same spectral efficiency, STIM can achieve
better performance compared to conventional orthogonal frequency division
multiplexing (OFDM). Low-complexity iterative algorithms for the detection of
large-dimensional STIM signals are also presented.


title: Replica methods for loopy sparse random graphs

abstract:
  I report on the development of a novel statistical mechanical formalism for
the analysis of random graphs with many short loops, and processes on such
graphs. The graphs are defined via maximum entropy ensembles, in which both the
degrees (via hard constraints) and the adjacency matrix spectrum (via a soft
constraint) are prescribed. The sum over graphs can be done analytically, using
a replica formalism with complex replica dimensions. All known results for
tree-like graphs are recovered in a suitable limit. For loopy graphs, the
emerging theory has an appealing and intuitive structure, suggests how message
passing algorithms should be adapted, and what is the structure of theories
describing spin systems on loopy architectures. However, the formalism is still
largely untested, and may require further adjustment and refinement.


title:
Interpretation of monoclinic hafnia valence electron energy loss spectra
  by TDDFT

abstract:
  We present the valence electron energy-loss spectrum and the dielectric
function of monoclinic hafnia (m-HfO$_2$) obtained from time-dependent
density-functional theory (TDDFT) predictions and compared to energy-filtered
spectroscopic imaging measurements in a high-resolution transmission-electron
microscope. Fermi's Golden Rule density-functional theory (DFT) calculations
can capture the qualitative features of the energy-loss spectrum, but we find
that TDDFT, which accounts for local-field effects, provides nearly
quantitative agreement with experiment. Using the DFT density of states and
TDDFT dielectric functions, we characterize the excitations that result in the
m-HfO$_2$ energy loss spectrum. The sole plasmon occurs between 13-16 eV,
although the peaks $\sim$28 and above 40 eV are also due to collective
excitations. We furthermore elaborate on the first-principles techniques used,
their accuracy, and remaining discrepancies among spectra. More specifically,
we assess the influence of Hf semicore electrons (5$p$ and 4$f$) on the
energy-loss spectrum, and find that the inclusion of transitions from the 4$f$
band damps the energy-loss intensity in the region above 13 eV. We study the
impact of many-body effects in a DFT framework using the adiabatic
local-density approximation (ALDA) exchange-correlation kernel, as well as from
a many-body perspective using a $GW$-derived electronic structure to account
for self-energy corrections. These results demonstrate some cancellation of
errors between self-energy and excitonic effects, even for excitations from the
Hf $4f$ shell. We also simulate the dispersion with increasing momentum
transfer for plasmon and collective excitation peaks.


title: Symmetry vs Symmetry

abstract:
  This preprint deals with the symmetry of parametrized families of systems and
the changes therein as the parameter changes. There are (at least ?) two kinds
of symmetry: generic and specific which behave in almost totally opposite ways
as the parameter changes: generic symmetry has links with entropy while
specific symmetry has to do with symmetry breaking as it is usually understood
in physics.


title: On the rate of change of the best constant in the Sobolev inequality

abstract:
  We estimate the rate of change of the best constant in the Sobolev inequality
of a Euclidean domain which moves outward. Along the way we prove an inequality
which reverses the usual Holder inequality, which may be of independent
interest.


title: Non-extensive condensation in reinforced branching processes

abstract:
  We study a class of branching processes in which a population consists of
immortal individuals equipped with a fitness value. Individuals produce
offspring with a rate given by their fitness, and offspring may either belong
to the same family, sharing the fitness of their parent, or be founders of new
families, with a fitness sampled from a fitness distribution. Examples that can
be embedded in this class are stochastic house-of-cards models, urn models with
reinforcement, and the preferential attachment tree of Bianconi and Barabasi.
Our focus is on the case when the fitness distribution has bounded support and
regularly varying tail at the essential supremum. In this case there exists a
condensation phase, in which asymptotically a proportion of mass in the
empirical fitness distribution of the overall population condenses in the
maximal fitness value. Our main results describe the asymptotic behaviour of
the size and fitness of the largest family at a given time. In particular, we
show that as time goes to infinity the size of the largest family is always
negligible compared to the overall population size. This implies that
condensation, when it arises, is non-extensive and emerges as a collective
effort of several families none of which can create a condensate on its own.
Our result disproves claims made in the physics literature in the context of
preferential attachment trees.


title:
On the quantum mechanical three-body problem with zero-range
  interactions

abstract:
  In this note we discuss the quantum mechanical three-body problem with
pairwise zero-range interactions in dimension three. We review the state of the
art concerning the construction of the corresponding Hamiltonian as a
self-adjoint operator in the bosonic and in the fermionic case. Exploiting a
quadratic form method, we also prove self-adjointness and boundedness from
below in the case of three identical bosons when the Hilbert space is suitably
restricted, i.e., excluding the "s-wave" subspace.


title: Rigidity and reconstruction for graphs

abstract:
  We present measure theoretic rigidity for graphs of first Betti number b>1 in
terms of measures on the boundary of a 2b-regular tree, that we make explicit
in terms of the edge-adjacency and closed-walk structure of the graph. We prove
that edge-reconstruction of the entire graph is equivalent to that of the
"closed walk lengths".


title: Finite Nuclei in the Quark-Meson Coupling (QMC) Model

abstract:
  We report the first use of the effective QMC energy density functional (EDF),
derived from a quark model of hadron structure, to study a broad range of
ground state properties of even-even nuclei across the periodic table in the
non-relativistic Hartree-Fock+BCS framework. The novelty of the QMC model is
that the nuclear medium effects are treated through modification of the
internal structure of the nucleon. The density dependence is microscopically
derived and the spin-orbit term arises naturally. The QMC EDF depends on a
single set of four adjustable parameters having clear physical basis. When
applied to diverse ground state data the QMC EDF already produces, in its
present simple form, overall agreement with experiment of a quality comparable
to a representative Skyrme EDF. There exist however multiple Skyrme paramater
sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF
set of fewer parameters, as derived in this work, is not open to such
variation, chosen set being applied, without adjustment, to both the properties
of finite nuclei and nuclear matter.


title:
Interference Management in Heterogeneous Networks with Blind
  Transmitters

abstract:
  Future multi-tier communication networks will require enhanced network
capacity and reduced overhead. In the absence of Channel State Information
(CSI) at the transmitters, Blind Interference Alignment (BIA) and Topological
Interference Management (TIM) can achieve optimal Degrees of Freedom (DoF),
minimising network's overhead. In addition, Non-Orthogonal Multiple Access
(NOMA) can increase the sum rate of the network, compared to orthogonal radio
access techniques currently adopted by 4G networks. Our contribution is two
interference management schemes, BIA and a hybrid TIM-NOMA scheme, employed in
heterogeneous networks by applying user-pairing and Kronecker Product
representation. BIA manages inter- and intra-cell interference by antenna
selection and appropriate message scheduling. The hybrid scheme manages
intra-cell interference based on NOMA and inter-cell interference based on TIM.
We show that both schemes achieve at least double the rate of TDMA. The hybrid
scheme always outperforms TDMA and BIA in terms of Degrees of Freedom (DoF).
Comparing the two proposed schemes, BIA achieves more DoF than TDMA under
certain restrictions, and provides better Bit-Error-Rate (BER) and sum rate
performance to macrocell users, whereas the hybrid scheme improves the
performance of femtocell users.


title: Finding Outliers in Surface Data and Video

abstract:
  Surface, image and video data can be considered as functional data with a
bivariate domain. To detect outlying surfaces or images, a new method is
proposed based on the mean and the variability of the degree of outlyingness at
each grid point. A rule is constructed to flag the outliers in the resulting
functional outlier map. Heatmaps of their outlyingness indicate the regions
which are most deviating from the regular surfaces. The method is applied to
fluorescence excitation-emission spectra after fitting a PARAFAC model, to MRI
image data which are augmented with their gradients, and to video surveillance
data.


title:
Collective motion patterns of swarms with delay coupling: theory and
  experiment

abstract:
  The formation of coherent patterns in swarms of interacting self-propelled
autonomous agents is a subject of great interest in a wide range of application
areas, ranging from engineering and physics to biology. In this paper, we model
and experimentally realize a mixed-reality large-scale swarm of delay-coupled
agents. The coupling term is modeled as a delayed communication relay of
position. Our analyses, assuming agents communicating over an Erdos-Renyi
network, demonstrate the existence of stable coherent patterns that can only be
achieved with delay coupling and that are robust to decreasing network
connectivity and heterogeneity in agent dynamics. We also show how the
bifurcation structure for emergence of different patterns changes with
heterogeneity in agent acceleration capabilities and limited connectivity in
the network as a function of coupling strength and delay. Our results are
verified through simulation as well as preliminary experimental results of
delay-induced pattern formation in a mixed-reality swarm.


title: Sum rules and large deviations for spectral matrix measures

abstract:
  A sum rule relative to a reference measure on R is a relationship between the
reversed Kullback-Leibler divergence of a positive measure on R and some
non-linear functional built on spectral elements related to this measure (see
for example Killip and Simon 2003). In this paper, using only probabilistic
tools of large deviations, we extend the sum rules obtained in Gamboa, Nagel
and Rouault (2015) to the case of Hermitian matrix-valued measures. We recover
the earlier result of Damanik, Killip and Simon (2010) when the reference
measure is the (matrix-valued) semicircle law and obtain a new sum rule when
the reference measure is the (matrix-valued) Marchenko-Pastur law.


title: Fractional Poisson Fields and Martingales

abstract:
  We present new properties for the Fractional Poisson process and the
Fractional Poisson field on the plane. A martingale characterization for
Fractional Poisson processes is given. We extend this result to Fractional
Poisson fields, obtaining some other characterizations. The fractional
differential equations are studied. We consider a more general Mixed-Fractional
Poisson process and show that this process is the stochastic solution of a
system of fractional differential-difference equations. Finally, we give some
simulations of the Fractional Poisson field on the plane.


title: Otto engine beyond its standard quantum limit

abstract:
  We propose a quantum Otto cycle based on the properties of a two-level system
in a realistic out-of-thermal-equilibrium electromagnetic field acting as its
sole reservoir. This steady configuration is produced without the need of
active control over the state of the environment, which is a non-coherent
thermal radiation, sustained only by external heat supplied to macroscopic
objects. Remarkably, even for non-ideal finite-time transformations, it largely
over-performs the standard ideal Otto cycle, and asymptotically achieves unit
efficiency at finite power.


title: A Swift view on IGR~J19149+1036

abstract:
  IGR~J19149+1036 is a high mass X-ray binary detected by INTEGRAL in 2011 in
the hard X-ray domain. We have analyzed the BAT survey data of the first 103
months of the Swift mission detecting this source at a significance level of
~30 standard deviations. The timing analysis on the long term BAT light curve
reveals the presence of a strong sinusoidal intensity modulation of 22.25+/-
0.05 d, that we interpret as the orbital period of this binary system.
  A broad band (0.3-150 keV) spectral analysis was performed combining the BAT
spectrum and the XRT spectra from the pointed follow up observations. The
spectrum is adequately modeled with an absorbed power law with a high energy
cutoff at ~24 keV and an absorption cyclotron feature at ~31 keV. Correcting
for the gravitational redshift, the inferred magnetic field at the neutron star
surface is B_surf ~ 3.6 x 10^12 gauss.


title: Quantitative Evaluation of Chaotic CBC Mode of Operation

abstract:
  The cipher block chaining (CBC) block cipher mode of operation presents a
very popular way of encrypting which is used in various applications. In
previous research work, we have mathematically proven that, under some
conditions, this mode of operation can admit a chaotic behavior according to
Devaney. Proving that CBC mode is chaotic is only the beginning of the study of
its security. The next step, which is the purpose of this paper, is to develop
the quantitative study of the chaotic CBC mode of operation by evaluating the
level of sensibility and expansivity for this mode.


title: Eternal Hilltop Inflation

abstract:
  We consider eternal inflation in hilltop-type inflation models, favored by
current data, in which the scalar field in inflation rolls off of a local
maximum of the potential. Unlike chaotic or plateau-type inflation models, in
hilltop inflation the region of field space which supports eternal inflation is
finite, and the expansion rate $H_{EI}$ during eternal inflation is almost
exactly the same as the expansion rate $H_*$ during slow roll inflation.
Therefore, in any given Hubble volume, there is a finite and calculable
expectation value for the lifetime of the "eternal" inflation phase, during
which quantum flucutations dominate over classical field evolution. We show
that despite this, inflation in hilltop models is nonetheless eternal in the
sense that the volume of the spacetime at any finite time is exponentially
dominated by regions which continue to inflate. This is true regardless of the
energy scale of inflation, and eternal inflation is supported for inflation at
arbitrarily low energy scale.


title:
On feedback stabilization of linear switched systems via switching
  signal control

abstract:
  Motivated by recent applications in control theory, we study the feedback
stabilizability of switched systems, where one is allowed to chose the
switching signal as a function of $x(t)$ in order to stabilize the system. We
propose new algorithms and analyze several mathematical features of the problem
which were unnoticed up to now, to our knowledge. We prove complexity results,
(in-)equivalence between various notions of stabilizability, existence of
Lyapunov functions, and provide a case study for a paradigmatic example
introduced by Stanford and Urbano.


title: Orbit full groups for locally compact groups

abstract:
  We show that the topological rank of an orbit full group generated by an
ergodic, probability measure-preserving free action of a non-discrete
unimodular locally compact Polish group is two. For this, we use the existence
of a cross section and show that for a locally compact Polish group, the full
group generated by any dense subgroup is dense in the orbit full group of the
action of the group.
  We prove that the orbit full group of a free action of a locally compact
Polish group is extremely amenable if and only if the acting group is amenable,
using the fact that the full group generates the von Neumann algebra of the
action.


title:
mr: a C++ library for the matching and running of the Standard Model
  parameters

abstract:
  We present the C++ program library mr that allows us to reliably calculate
the values of the running parameters in the Standard Model at high energy
scales. The initial conditions are obtained by relating the running parameters
in the $\overline{\mathrm{MS}}$ renormalization scheme to observables at lower
energies with full two-loop precision. The evolution is then performed in
accordance with the renormalization group equations with full three-loop
precision. Pure QCD corrections to the matching and running are included
through four loops. We also provide a Mathematica interface for this program
library.


title: Monomial convergence for holomorphic functions on $\ell\_r$

abstract:
  Let $\mathcal F$ be either the set of all bounded holomorphic functions or
the set of all $m$-homogeneous polynomials on the unit ball of $\ell\_r$. We
give a systematic study of the sets of all $u\in\ell\_r$ for which the monomial
expansion $\sum\_{\alpha}\frac{\partial^\alpha f(0)}{\alpha !}u^\alpha$ of
every $f\in\mathcal F$ converges. Inspired by recent results from the general
theory of Dirichlet series, we establish as our main tool, independently
interesting, upper estimates for the unconditional basis constants of spaces of
polynomials on $\ell\_r$ spanned by finite sets of monomials.


title:
Positivity-preserving discontinuous Galerkin methods with Lax-Wendroff
  time discretizations

abstract:
  This work introduces a single-stage, single-step method for the compressible
Euler equations that is provably positivity-preserving and can be applied on
both Cartesian and unstructured meshes. This method is the first case of a
single-stage, single-step method that is simultaneously high-order,
positivity-preserving, and operates on unstructured meshes. Time-stepping is
accomplished via the Lax-Wendroff approach, which is also sometimes called the
Cauchy-Kovalevskaya procedure, where temporal derivatives in a Taylor series in
time are exchanged for spatial derivatives. The Lax-Wendroff discontinuous
Galerkin (LxW-DG) method developed in this work is formulated so that it looks
like a forward Euler update but with a high-order time-extrapolated flux. In
particular, the numerical flux used in this work is a linear combination of a
low-order positivity-preserving contribution and a high-order component that
can be damped to enforce positivity of the cell averages for the density and
pressure for each time step. In addition to this flux limiter, a moment limiter
is applied that forces positivity of the solution at finitely many quadrature
points within each cell. The combination of the flux limiter and the moment
limiter guarantees positivity of the cell averages from one time-step to the
next. Finally, a simple shock capturing limiter that uses the same basic
technology as the moment limiter is introduced in order to obtain
non-oscillatory results. The resulting scheme can be extended to arbitrary
order without increasing the size of the effective stencil. We present
numerical results in one and two space dimensions that demonstrate the
robustness of the proposed scheme.


title:
On the cohomology of almost complex and symplectic manifolds and proper
  surjective maps

abstract:
  Let $(X,J)$ be an almost-complex manifold. In \cite{li-zhang} Li and Zhang
introduce $H^{(p,q),(q,p)}_J(X)_{\rr}$ as the cohomology subgroups of the
$(p+q)$-th de Rham cohomology group formed by classes represented by real
pure-type forms. Given a proper, surjective, pseudo-holomorphic map between two
almost-complex manifolds we study the relationship among such cohomology
groups. Similar results are proven in the symplectic setting for the cohomology
groups introduced in \cite{tsengyauI} by Tseng and Yau and a new
characterization of the Hard Lefschetz condition in dimension $4$ is provided.


title:
Lightening of Assumptions for Pontryagin Principles in Infinite Horizon
  and Discrete Time

abstract:
  In the infinite-horizon and discrete-time framework we establish maximum
principles of Pontryagin under assumptions which weaker than these ones of
existing results. We avoid several assumptions of continuity and of
Fr{\'e}chet-differentiability and of linear independence. MSC 2010: 49J21,
65K05, 39A99.


title:
Swift reveals the eclipsing nature of the high mass X-ray binary
  IGR~J16195-4945

abstract:
  IGR J16195-4945 is a hard X-ray source discovered by INTEGRAL during the Core
Program observations performed in 2003. We analyzed the X-ray emission of this
source exploiting the Swift-BAT survey data from December 2004 to March 2015,
and all the available Swift-XRT pointed observations. The source is detected at
a high significance level in the 123-month BAT survey data, with an average
15-150 keV flux of the source of ~1.6 mCrab. The timing analysis on the BAT
data reveals with a significance higher than 6 standard deviations the presence
of a modulated signal with a period of 3.945 d, that we interpret as the
orbital period of the binary system. The folded light curve shows a flat
profile with a narrow full eclipse lasting ~3.5% of the orbital period. We
requested phase-constrained XRT observations to obtain a more detailed
characterization of the eclipse in the soft X-ray range. Adopting resonable
guess values for the mass and radius of the companion star, we derive a
semi-major orbital axis of ~31 R_sun, equivalent to ~1.8 times the radius of
the companion star. From these estimates and from the duration of the eclipse
we derive an orbital inclination between 55 and 60 degrees. The broad band
time-averaged XRT+BAT spectrum is well modeled with a strongly absorbed flat
power law, with absorbing column N_H=7x 10^22 cm^(-2) and photon index
Gamma=0.5, modified by a high energy exponential cutoff at E_cut=14 keV.


title:
Liouville correspondence between the Short-Pulse Hierarchy and the
  Sine-Gordon Hierarchy

abstract:
  This paper considers the whole hierarchy of bi-Hamiltonian integrable
equations associated to each of the Short-Pulse (SP) equation and the
Sine-Gordon (SG) equation. We prove that the transformation that relates the SP
equation with the SG equation also serves to establish the correspondence
between their flows and Hamiltonian conservation laws in respective hierarchy.


title:
Spin torque driven dynamics of a coupled two layer structure: interplay
  between conservative and dissipative coupling

abstract:
  In this manuscript the general concepts of spin wave theory are adapted to
the dynamics of a self-polarized system based on two layers coupled via
interlayer exchange (conservative coupling) and mutual spin torque (dissipative
coupling). An analytical description of the non-linear dynamics is proposed and
validated through numerical simulations. In contrast to the single layer model,
the phase equation of the coupled system has a contribution coming from the
dissipative part of the LLGS equation. It is shown that this is a major
contribution to the frequency mandatory to describe well the most basic
features of the dynamics of coupled systems. Using the proposed model a
specific feature of coupled dynamics is addressed: the redshift to blueshift
transition observed in the frequency current dependence of this kind of
exchange coupled systems upon increasing the applied field. It is found that
the blueshift regime can only occur in a region of field where the two linear
eigenmodes contribute equally to the steady state mode (i.e. high mode
hybridization). Finally, a general perturbed Hamiltonian equation for the
coupled system is proposed.


title:
On the persistence regime for Lotka-Volterra in randomly fluctuating
  environments

abstract:
  In this note, we study the long time behavior of Lotka-Volterra systems whose
coefficients vary randomly. Bena{\"i}m and Lobry (2015) recently established
that randomly switching between two environments that are both favorable to the
same species may lead to different regimes: extinction of one species or the
other, or persistence of both species. Our purpose here is to describe more
accurately the range of parameters leading to these regimes, and the support of
the invariant probability measure in case of persistence.


title:
Comparing the Morse index and the first Betti number of minimal
  hypersurfaces

abstract:
  By extending and generalising previous work by Ros and Savo, we describe a
method to show that the Morse index of every closed minimal hypersurface on
certain positively curved ambient manifolds is bounded from below by a linear
function of its first Betti number. The technique is flexible enough to prove
that such a relation between the index and the topology of minimal
hypersurfaces holds, for example, on all compact rank one symmetric spaces, on
products of the circle with spheres of arbitrary dimension and on suitably
pinched submanifolds of the Euclidean spaces. These results confirm a general
conjecture due to Schoen and Marques-Neves for a wide class of ambient spaces.


title: Particle transport after pellet injection in the TJ-II stellarator

abstract:
  We study radial particle transport in stellarator plasmas using cryogenic
pellet injection. By means of perturbative experiments, we estimate the
experimental particle flux and compare it with neoclassical simulations.
Experimental evidence is obtained of the fact that core depletion in helical
devices can be slowed-down even by pellets that do not reach the core region.
This phenomenon is well captured by neoclassical predictions with DKES and
FORTEC-3D.


title:
JADE, TraSMAPI and SUMO: A tool-chain for simulating traffic light
  control

abstract:
  Increased stress, fuel consumption, air pollution, accidents and delays are
some of the consequences of traffic congestion usually incurring in tremendous
economic impacts, which society aims to remedy in order to leverage a
sustainable development. Recently, unconventional means for modeling and
controlling such complex traffic systems relying on multi-agent systems have
arisen. This paper contributes to the understanding of such complex and highly
dynamic systems by proposing an open-source tool-chain to implement
multi-agent-based solutions in traffic and transportation. The proposed
approach relies on two very popular tools in both domains, with focus on
traffic light control. This tool-chain consists in combining JADE (Java Agent
DEvelopment Framework), for the implementation of multi-agent systems, with
SUMO (Simulation of Urban MObility), for the microscopic simulation of traffic
interactions. TraSMAPI (Traffic Simulation Manager Application Programming
Interface) is used to combine JADE and SUMO allowing communication between
them. A demonstration of the concept is presented to illustrate the main
features of this tool-chain, using Q-Learning as the reinforcement learning
method for each traffic light agent in a simulated network. Results demonstrate
the feasibility of the proposed framework as a practical means to experiment
with different agent-based designs of intelligent transportation solutions.


title:
Expert Opinions and Logarithmic Utility Maximization for Multivariate
  Stock Returns with Gaussian Drift

abstract:
  This paper investigates optimal trading strategies in a financial market with
multidimensional stock returns where the drift is an unobservable multivariate
Ornstein-Uhlenbeck process. Information about the drift is obtained by
observing stock returns and expert opinions. The latter provide unbiased
estimates on the current state of the drift at discrete points in time.
  The optimal trading strategy of investors maximizing expected logarithmic
utility of terminal wealth depends on the filter which is the conditional
expectation of the drift given the available information. We state filtering
equations to describe its dynamics for different information settings. Between
expert opinions this is the Kalman filter. The conditional covariance matrices
of the filter follow ordinary differential equations of Riccati type. We rely
on basic theory about matrix Riccati equations to investigate their properties.
Firstly, we consider the asymptotic behaviour of the covariance matrices for an
increasing number of expert opinions on a finite time horizon. Secondly, we
state conditions for the convergence of the covariance matrices on an infinite
time horizon with regularly arriving expert opinions.
  Finally, we derive the optimal trading strategy of an investor. The optimal
expected logarithmic utility of terminal wealth, the value function, is a
functional of the conditional covariance matrices. Hence, our analysis of the
covariance matrices allows us to deduce properties of the value function.


title: Wavefront shaping for opaque cylindrical lenses

abstract:
  Wavefront shaping has revolutionized the concepts of optical imaging and
focusing. Contrary to what was believed, strong scattering in the optical paths
can be exploited in favor of light focusing through turbid media and ultimately
improve optical imaging and light manipulation capabilities. The use of light
shapers and appropriately engineered scattering structures, i.e. opaque lenses
enables the production of nano-scale confined foci and of extended fields of
view. Exploiting this concept we fabricate configurable scattering structures
by direct femtosecond laser writing. The properly shaped light trespassing the
customized structure, a photonic lattice of parallel rods, forms a light-sheet
at user defined positions. We demonstrate that our technique enables
light-sheets with sub-micron resolution and extended depth of focus, a
significant advantage when compared to the existing free space systems.
Moreover, our approach permits to focus light of different wavelengths onto the
same defined position without moving any optical element and correcting for
chromatic aberrations. Furthermore, we demonstrate how an opaque cylindrical
lens can be created using a biological structure, hence unveiling the potential
advantages for optical microscopic and mesoscopic imaging.


title:
A pancake droplet translating in a Hele-Shaw cell: lubrication film and
  flow field

abstract:
  We adopt a boundary integral method to study the dynamics of a translating
droplet confined in a Hele-Shaw cell in the Stokes regime. The droplet is
driven by the motion of the ambient fluid with the same viscosity. We
characterize the three-dimensional (3D) nature of the droplet interface and of
the flow field. The interface develops an arc-shaped ridge near the rear-half
rim with a protrusion in the rear and a laterally symmetric pair of higher
peaks; this pair of protrusions has been identified by recent experiments
(Huerre et al., Phys. Rev. Lett., vol. 115 (6), 2015, 064501) and predicted
asymptotically (Burgess and Foster, Phys. Fluids A, vol. 2 (7), 1990, pp.
1105-1117). The mean film thickness is well predicted by the extended
Bretherton model (Klaseboer et al., Phys. Fluids, vol. 26 (3), 2014, 032107)
with fitting parameters. The flow in the streamwise wall-normal middle plane is
featured with recirculating zones, which are partitioned by stagnation points
closely resembling those of a two-dimensional droplet in a channel.
Recirculation is absent in the wall-parallel, unconfined planes, in sharp
contrast to the interior flow inside a moving droplet in free space. The
preferred orientation of the recirculation results from the anisotropic
confinement of the Hele-Shaw cell. On these planes, we identify a dipolar
disturbance flow field induced by the travelling droplet and its $1/r^2$
spatial decay is confirmed numerically. We pinpoint counter-rotating streamwise
vortex structures near the lateral interface of the droplet, further
highlighting the complex 3D flow pattern.


title: Semantic Localization in the PCL library

abstract:
  The semantic localization problem in robotics consists in determining the
place where a robot is located by means of semantic categories. The problem is
usually addressed as a supervised classification process, where input data
correspond to robot perceptions while classes to semantic categories, like
kitchen or corridor.
  In this paper we propose a framework, implemented in the PCL library, which
provides a set of valuable tools to easily develop and evaluate semantic
localization systems. The implementation includes the generation of 3D global
descriptors following a Bag-of-Words approach. This allows the generation of
dimensionality-fixed descriptors from any type of keypoint detector and feature
extractor combinations. The framework has been designed, structured and
implemented in order to be easily extended with different keypoint detectors,
feature extractors as well as classification models.
  The proposed framework has also been used to evaluate the performance of a
set of already implemented descriptors, when used as input for a specific
semantic localization system. The results obtained are discussed paying special
attention to the internal parameters of the BoW descriptor generation process.
Moreover, we also review the combination of some keypoint detectors with
different 3D descriptor generation techniques.


title:
Chains of benzenes with lithium-atom adsorption: Vibrations and
  spontaneous symmetry breaking

abstract:
  We study effects of different configurations of adsorbates on the vibrational
modes as well as symmetries of polyacenes and poly-p-phenylenes focusing on
lithium atom adsorption. We found that the spectra of the vibrational modes
distinguish the different configurations. For more regular adsorption schemes
the lowest states are bending and torsion modes of the skeleton, which are
essentially followed by the adsorbate. On poly-p-phenylenes we found that
lithium adsorption reduces and often eliminates the torsion between rings thus
increasing symmetry. There is spontaneous symmetry breaking in
poly-p-phenylenes due to double adsorption of lithium atoms on alternating
rings.


title:
Predictions for $\sqrt {s_{NN}}=5.02$ TeV Pb+Pb Collisions from a
  Multi-Phase Transport Model

abstract:
  We present predictions from the string melting version of a multi-phase
transport model on various observables in Pb+Pb collisions at $\sqrt
{s_{NN}}=5.02$ TeV. We use the same version of the model as an earlier study
that reasonably reproduced dN/dy, $p_{\rm T}$-spectra and elliptic flow of
charged pions and kaons at low-$p_{\rm T}$ for central and semi-central heavy
ion collisions at 200 GeV and 2.76 TeV. While we compare with the
already-available centrality dependence data on charged particle $dN/d\eta$ at
mid-pseudorapidity in Pb+Pb collisions at 5.02 TeV, we make predictions on
identified particle dN/dy, $p_{\rm T}$-spectra, azimuthal anisotropies $v_n
(n=2,3,4)$, and factorization ratios $r_{n}(\eta^{a},\eta^{b}) (n=2,3)$ for
longitudinal correlations.


title: Sub-Poisson States Heralded at a Hong-Ou-Mandel Interference Peak

abstract:
  A peak in coincidence events has been observed in a modified Hong-Ou-Mandel
interferometer fed with weak coherent states inside the region of overlapping
wave-packets. The inversion of the usual interference pattern represented by
the HOM dip is equally observed when the wave packets are frequency displaced.
The higher rate of coincidences indicates that photons are more likely to take
on different output paths of the interferometer. This effect was harnessed so a
detection on one of the arms could herald the presence of a photon in the
other. The second order autocorrelation function at zero time was
experimentally determined by means of the Hanburry-Brown and Twiss experiment
and its value below 1 confirmed the sub-Poisson photon statistics of the
heralded states.


title: A State-of-the-art Integrated Transportation Simulation Platform

abstract:
  Nowadays, universities and companies have a huge need for simulation and
modelling methodologies. In the particular case of traffic and transportation,
making physical modifications to the real traffic networks could be highly
expensive, dependent on political decisions and could be highly disruptive to
the environment. However, while studying a specific domain or problem,
analysing a problem through simulation may not be trivial and may need several
simulation tools, hence raising interoperability issues. To overcome these
problems, we propose an agent-directed transportation simulation platform,
through the cloud, by means of services. We intend to use the IEEE standard HLA
(High Level Architecture) for simulators interoperability and agents for
controlling and coordination. Our motivations are to allow multiresolution
analysis of complex domains, to allow experts to collaborate on the analysis of
a common problem and to allow co-simulation and synergy of different
application domains. This paper will start by presenting some preliminary
background concepts to help better understand the scope of this work. After
that, the results of a literature review is shown. Finally, the general
architecture of a transportation simulation platform is proposed.


title: Summability of joint cumulants of nonindependent lattice fields

abstract:
  We consider two nonindependent random fields $\psi$ and $\phi$ defined on a
countable set $Z$. For instance, $Z={\mathbb Z}^d$ or $Z={\mathbb Z}^d\times
I$, where $I$ denotes a finite set of possible "internal degrees of freedom"
such as spin. We prove that, if the cumulants of both $\psi$ and $\phi$ are
$\ell_1$-clustering up to order $2 n$, then all joint cumulants between $\psi$
and $\phi$ are $\ell_2$-summable up to order $n$, in the precise sense
described in the text. We also provide explicit estimates in terms of the
related $\ell_1$-clustering norms, and derive a weighted $\ell_2$-summation
property of the joint cumulants if the fields are merely $\ell_2$-clustering.
One immediate application of the results is given by a stochastic process
$\psi_t(x)$ whose state is $\ell_1$-clustering at any time $t$: then the above
estimates can be applied with $\psi=\psi_t$ and $\phi=\psi_0$ and we obtain
uniform in $t$ estimates for the summability of time-correlations of the field.
The above clustering assumption is obviously satisfied by any
$\ell_1$-clustering stationary state of the process, and our original
motivation for the control of the summability of time-correlations comes from a
quest for a rigorous control of the Green-Kubo correlation function in such a
system. A key role in the proof is played by the properties of non-Gaussian
Wick polynomials and their connection to cumulants.


title: Non-Abelian Aharonov-Bohm effect with the time-dependent gauge fields

abstract:
  We investigate the non-Abelian Aharonov-Bohm (AB) effect for time-dependent
gauge fields. We prove that the non-Abelian AB phase shift related to
time-dependent gauge fields, in which the electric and magnetic fields are
written in the adjoint representation of $SU(N)$ generators, vanishes up to the
first order expansion of the phase factor. Therefore, the flux quantization in
a superconductor ring does not appear in the time-dependent Abelian or
non-Abelian AB effect.