title: Spatial Mappings for Planning and Optimization of Cellular Networks

abstract:
  In cellular networks, users are grouped into different cells and served by
different access points (base stations) that provide wireless access to
services and applications. In general, the service demand is very
heterogeneous, non-uniformly distributed, and dynamic. Consequently, radio
access networks create very irregular topologies with more access points where
service demand is concentrated. While this dynamism requires networks with the
ability to adapt to time-varying conditions, the non-uniformity of the service
demand makes the planning, analysis, and optimization difficult. In order to
help with these tasks, a framework based on canonical domains and spatial
mappings (e.g., conformal mapping) have recently been proposed. The idea is to
carry out part of the planning in a canonical (perfectly symmetric) domain that
is connected to the physical one (real-scenario) by means of a spatial
transformation designed to map the access points consistently with the service
demand. This paper continues the research in that direction by introducing
additional tools and possibilities to that framework, namely the use of
centroidal Voronoi algorithms and non-conformal composite mappings. Moreover,
power optimization is also introduced to the framework. The results show the
usability and effectiveness of the proposed method and its promising research
perspectives.


title:
Radiative capture reaction for $^{17}$Ne formation within a full
  three-body model

abstract:
  Background: The breakout from the hot Carbon-Nitrogen-Oxigen (CNO) cycles can
trigger the rp-process in type I x-ray bursts. In this environment, a
competition between $^{15}\text{O}(\alpha,\gamma){^{19}\text{Ne}}$ and the
two-proton capture reaction $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$ is
expected.
  Purpose: Determine the three-body radiative capture reaction rate for
${^{17}\text{Ne}}$ formation including sequential and direct, resonant and
non-resonant contributions on an equal footing.
  Method: Two different discretization methods have been applied to generate
$^{17}$Ne states in a full three-body model: the analytical transformed
harmonic oscillator method and the hyperspherical adiabatic expansion method.
The binary $p$--$^{15}$O interaction has been adjusted to reproduce the known
spectrum of the unbound $^{16}$F nucleus. The dominant $E1$ contributions to
the $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$ reaction rate have been
calculated from the inverse photodissociation process.
  Results: Three-body calculations provide a reliable description of $^{17}$Ne
states. The agreement with the available experimental data on $^{17}$Ne is
discussed. It is shown that the $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$
reaction rates computed within the two methods agree in a broad range of
temperatures. The present calculations are compared with a previous theoretical
estimation of the reaction rate.
  Conclusions: It is found that the full three-body model provides a reaction
rate several orders of magnitude larger than the only previous estimation. The
implications for the rp-process in type I x-ray bursts should be investigated.


title: Goal-Driven Unfolding of Petri Nets

abstract:
  Unfoldings provide an efficient way to avoid the state-space explosion due to
interleavings of concurrent transitions when exploring the runs of a Petri net.
The theory of adequate orders allows one to define finite prefixes of
unfoldings which contain all the reachable markings. In this paper we are
interested in reachability of a single given marking, called the goal. We
propose an algorithm for computing a finite prefix of the unfolding of a 1-safe
Petri net that preserves all minimal configurations reaching this goal. Our
algorithm combines the unfolding technique with on-the-fly model reduction by
static analysis aiming at avoiding the exploration of branches which are not
needed for reaching the goal. We present some experimental results.


title:
Tunable, Low Optical Loss Strontium Molybdate Thin Films for Plasmonic
  Applications

abstract:
  Strontium molybdate (SrMoO3) thin films are shown to exhibit plasmonic
behaviour with a zero crossover wavelength of the real part of the dielectric
permittivity tunable between 600 and 950 nm (2.05 eV and 1.31 eV). The films
are grown epitaxially on strontium titanate (SrTiO3), magnesium oxide (MgO),
and lanthanum aluminate (LaAlO3) substrates by pulsed laser deposition. SrMoO3
is shown to have optical losses lower than those of gold at the point at which
the real part of the dielectric permittivity is equal to -2, while possessing
low electrical resistivity of 100E-6 Ohm cm at room temperature. Spectroscopic
ellipsometry measurements reveal that SrMoO3 shows plasmonic behaviour,
moreover we demonstrate that the epsilon near zero (ENZ) wavelength is tunable
by engineering the residual strain in the films. The relatively broadband ENZ
behaviour observed in SrMoO3 demonstrates its potential suitability for
transformation optics along with plasmonic applications in the visible to near
infrared spectral range.


title:
Regularized Pel-Recursive Motion Estimation Using Generalized
  Cross-Validation and Spatial Adaptation

abstract:
  The computation of 2-D optical flow by means of regularized pel-recursive
algorithms raises a host of issues, which include the treatment of outliers,
motion discontinuities and occlusion among other problems. We propose a new
approach which allows us to deal with these issues within a common framework.
Our approach is based on the use of a technique called Generalized
Cross-Validation to estimate the best regularization scheme for a given pixel.
In our model, the regularization parameter is a matrix whose entries can
account for diverse sources of error. The estimation of the motion vectors
takes into consideration local properties of the image following a spatially
adaptive approach where each moving pixel is supposed to have its own
regularization matrix. Preliminary experiments indicate that this approach
provides robust estimates of the optical flow.


title:
Mode-decomposition based on crystallographic symmetry in the
  band-unfolding method

abstract:
  The band-unfolding method is widely used to calculate the effective band
structures of a disordered system from its supercell model. The unfolded band
structures show the crystallographic symmetry of the underlying structure,
where the difference of chemical components and the local atomic relaxation are
ignored. It has been, however, still difficult to decompose the unfolded band
structures into the modes based on the crystallographic symmetry of the
underlying structure, and therefore detailed analyses of the unfolded band
structures have been restricted. In this study, we develop a procedure to
decompose the unfolded band structures according to the small representations
(SRs) of the little groups. For this purpose, we derive the projection
operators for SRs based on the group representation theory. We also introduce
another type of projection operators for chemical elements, which enables us to
decompose the unfolded band structures into the contributions of different
combinations of chemical elements. Using the current method, we investigate the
phonon band structure of disordered face-centered cubic Cu0.75Au0.25, which has
large variations of atomic masses and force constants among the atomic sites
due to the chemical disorder. We find several peculiar behaviors such as
discontinuous and split branches in the unfolded phonon band structure. They
are found to occur because different combinations of the chemical elements
contribute to different regions of frequency.


title: Symmetry-unrestricted Skyrme mean-field study of heavy nuclei

abstract:
  In the light of recent experimental developments, increasing attention is
devoted to nuclear phenomena related to rotational excitations of exotic
intrinsic nuclear configurations that often lack symmetries present in the
majority of nuclei. Examples include configurations with a non-vanishing
octupole moment. In order to describe this kind of states, we have developed a
new computer code to solve the self-consistent mean-field equations, able to
use most of today's effective Skyrme interactions and working in
coordinate-space. We report on the development of MOCCa, a code based on the
same principles as EV8, but offering the user individual control on many
symmetry assumptions. In addition, the HF+BCS pairing treatment of EV8 has been
generalised to the full machinery of Hartree-Fock-Bogoliubov transformations.
We discuss as example the static fission barrier of $^{226}$Ra, prefacing
extended studies in the region, using the recent series of Skyrme
parameterizations SLy5s1 through SLy5s8.


title: M31N 2008-12a - The Remarkable Recurrent Nova in M31

abstract:
  M31N 2008-12a is a remarkable recurrent nova within the Andromeda Galaxy.
With eleven eruptions now identified, including eight in the past eight years,
the system exhibits a recurrence period of one year, and possibly just six
months. This short inter eruption period is driven by the combination of a high
mass white dwarf ($1.38\,\mathrm{M}_\odot$) and high mass accretion rate
($\sim1.6\times10^{-7}\,\mathrm{M}_\odot\,\mathrm{yr}^{-1}$). Such a high
accretion rate appears to be provided by the stellar wind of a red giant
companion. Deep H$\alpha$ observations have revealed the presence of a vastly
extended nebula around the system, which could be the `super-remnant' of many
thousands of past eruptions. With a prediction of the white dwarf reaching the
Chandrasekhar mass in less than a mega-year, M31N 2008-12a has become the
leading pre-explosion type Ia supernova candidate. The 2016 eruption - to be
the twelfth detected eruption - is expected imminently, and a vast array of
follow-up observations are already planned.


title:
Renormalization group analysis of a turbulent compressible fluid near $d
  = 4$ : Crossover between local and non-local scaling regimes

abstract:
  We study scaling properties of the model of fully developed turbulence for a
compressible fluid, based on the stochastic Navier-Stokes equation, by means of
the field theoretic renormalization group (RG). The scaling properties in this
approach are related to fixed points of the RG equation. Here we study a
possible existence of other scaling regimes and an opportunity of a crossover
between them. This may take place in some other space dimensions, particularly
at $d = 4$. A new regime may there arise and then by continuity moves into $d =
3$. Our calculations have shown that there really exists an additional fixed
point, that may govern scaling behaviour.


title: Stochastic non-isotropic degenerate parabolic-hyperbolic equations

abstract:
  We introduce the notion of pathwise entropy solutions for a class of
degenerate parabolic-hyperbolic equations with non-isotropic nonlinearity and
fluxes with rough time dependence and prove their well-posedness. In the case
of Brownian noise and periodic boundary conditions, we prove that the pathwise
entropy solutions converge to their spatial average and provide an estimate on
the rate of convergence. The third main result of the paper is a new
regularization result in the spirit of averaging lemmata. This work extends
both the framework of pathwise entropy solutions for stochastic scalar
conservation laws introduced by Lions, Perthame and Souganidis and the analysis
of the long time behavior of stochastic scalar conservation laws by the authors
to a new class of equations.


title:
Non-Hermitian interferometer: Unidirectional amplification without
  distortion

abstract:
  A non-Hermitian interferometer can realize asymmetric transmission in the
presence of imaginary potential and magnetic flux. Here, we propose a
non-Hermitian dimer with an unequal hopping rate by an interferometer-like
cluster in the framework of tight-binding model. The intriguing features of
this design are the wave-vector independence and unidirectionality of
scattering, which amplifies wavepacket without distortion and absorbs
incoherent wave without reflection. The absorption relates to the system
spectral singularities, the dynamical behaviors of the spectral singularities
are also investigated analytically and numerically.


title: Conference matrices with maximum excess and two-intersection sets

abstract:
  A two-intersection set with parameters $(j;\alpha,\beta)$ for a block design
is a $j$-subset of the point set of the design, which intersects every block in
$\alpha$ or $\beta$ points. In this paper, we show the existence of a
two-intersection set with parameters $(2m^2-m+1;m^2-m,m^2)$ for the block
design obtained from translations of the set of nonzero squares in the finite
field of order $q=4m^2+1$. As an application, we give a construction of
conference matrices with maximum excess based on the two-intersection sets.


title: Scaling limits for some random trees constructed inhomogeneously

abstract:
  We define some new sequences of recursively constructed random combinatorial
trees, and show that, after properly rescaling graph distance and equipping the
trees with the uniform measure on vertices, each sequence converges almost
surely to a real tree in the Gromov-Hausdorff-Prokhorov sense. The limiting
real trees are constructed via line-breaking the real half-line with a Poisson
process having rate $(\ell+1)t^\ell dt$, for each positive integer $\ell$, and
the growth of the combinatorial trees may be viewed as an inhomogeneous
generalization of R\'emy's algorithm.


title:
Second-harmonic generation as probe for structural and electronic
  properties of buried GaP/Si(001) interfaces

abstract:
  Optical second-harmonic generation is demonstrated to be a sensitive probe of
the buried interface between the lattice matched semiconductors gallium
phosphide and silicon with (001) orientation. Rotational anisotropy
measurements of SHG from GaP/Si show a strong isotropic component of the
response not present for pure Si(001) or GaP(001). The strength of the
overlaying anisotropic response directly correlates with the quality of the
interface as determined by atomically resolved scanning transmission electron
microscopy.Optical second-harmonic generation is demonstrated to be a sensitive
probe of the buried interface between the lattice matched semiconductors
gallium phosphide and silicon with (001) orientation. Rotational anisotropy
measurements of SHG from GaP/Si show a strong isotropic component of the
response not present for pure Si(001) or GaP(001). The strength of the
overlaying anisotropic response directly correlates with the quality of the
interface as determined by atomically resolved scanning transmission electron
microscopy. Systematic comparison of samples fabricated with different growth
modes in metal organic vapor phase epitaxy reveals that the anisotropy for
different polarization combinations can be used as a selective fingerprint for
the occurrence of anti-phase domains and twins. This all-optical technique can
be applied as an {\it in-situ} and non-invasive monitor even during growth.
Systematic comparison of samples fabricated with different growth modes in
metal organic vapor phase epitaxy reveals that the anisotropy for different
polarization combinations can be used as a selective fingerprint for the
occurrence of anti-phase domains and twins. This all-optical technique can be
applied as an {\it in-situ} and non-invasive monitor even during growth.


title:
Preparation of circular Rydberg states in helium using the crossed
  fields method

abstract:
  Helium atoms have been prepared in the circular
$|n=55,\ell=54,m_{\ell}=+54\rangle$ Rydberg state using the crossed electric
and magnetic fields method. The atoms, initially travelling in pulsed
supersonic beams, were photoexcited from the metastable $1s2s\,^3S_1$ level to
the outermost, $m_{\ell}=0$ Rydberg-Stark state with $n=55$ in the presence of
a strong electric field and weak perpendicular magnetic field. Following
excitation, the electric field was adiabatically switched off causing the atoms
to evolve into the circular state with $m_{\ell}=+54$ defined with respect to
the magnetic field quantization axis. The circular states were detected by
ramped electric field ionization along the magnetic field axis. The dependence
of the circular state production efficiency on the strength of the excitation
electric field, and the electric-field switch-off time was studied, and
microwave spectroscopy of the circular-to-circular
$|55,54,+54\rangle\rightarrow|56,55,+55\rangle$ transition at $\sim38.5$~GHz
was performed.


title: Conductivity and Discharge Guiding Properties of Mid-IR Laser Filaments

abstract:
  The electric conductivity, HV discharge triggering and guiding capabilities
of filaments at 3.9 micrometer in air are investigated in the perspective of
lightning control applications, and compared to near-IR filaments in identical
conditions


title: Achieving Shrinkage in a Time-Varying Parameter Model Framework

abstract:
  Shrinkage for time-varying parameter (TVP) models is investigated within a
Bayesian framework, with the aim to automatically reduce time-varying
parameters to static ones, if the model is overfitting. This is achieved
through placing the double gamma shrinkage prior on the process variances. An
efficient Markov chain Monte Carlo scheme is developed, exploiting boosting
based on the ancillarity-sufficiency interweaving strategy. The method is
applicable both to TVP models for univariate as well as multivariate time
series. Applications include a TVP generalized Phillips curve for EU area
inflation modelling and a multivariate TVP Cholesky stochastic volatility model
for joint modelling of the returns from the DAX-30 index.


title: On subelliptic manifolds

abstract:
  A smooth complex quasi-affine algebraic variety $Y$ is flexible if its
special group $\SAut (Y)$ of automorphisms (generated by the elements of
one-dimensional unipotent subgroups of $\Aut (Y)$) acts transitively on $Y$. An
irreducible algebraic manifold $X$ is locally stably flexible if it is the
union $\bigcup X_i$ of a finite number of Zariski open sets, each $X_i$ being
quasi-affine, so that there is a positive integer $N$ for which $X_i\times
\mathbb{C}^N$ is flexible for every $i$. The main result of this paper is that
the blowup of a locally stably flexible manifold at a smooth algebraic
submanifold (not necessarily equi-dimensional or connected) is subelliptic, and
hence Oka. This result is proven as a corollary of some general results
concerning the so-called $k$-flexible manifolds.


title: An Hierarchical Approach to Big Data

abstract:
  The increasing volumes of astronomical data require practical methods for
data exploration, access and visualisation. The Hierarchical Progressive Survey
(HiPS) is a HEALPix based scheme that enables a multi-resolution approach to
astronomy data from the individual pixels up to the whole sky. We highlight the
decisions and approaches that have been taken to make this scheme a practical
solution for managing large volumes of heterogeneous data. Early implementors
of this system have formed a network of HiPS nodes, with some 250 diverse data
sets currently available, with multiple mirror implementations for important
data sets. This hierarchical approach can be adapted to expose Big Data in
different ways. We describe how the ease of implementation, and local
customisation of the Aladin Lite embeddable HiPS visualiser have been keys for
promoting collaboration on HiPS.


title: Narain Gupta's three normal subgroup problem and group homology

abstract:
  This paper is about application of various homological methods to classical
problems in the theory of group rings. It is shown that the third homology of
groups plays a key role in Narain Gupta's three normal subgroup problem. For a
free group $F$ and its normal subgroups $R,\,S,\,T,$ and the corresponding
ideals in the integral group ring $\mathbb Z[F]$, ${\bf r}=(R-1)\mathbb Z[F],\
{\bf s}=(S-1)\mathbb Z[F],\ {\bf t}=(T-1)\mathbb Z[F],$ a complete description
of the normal subgroup $F\cap (1+{\bf rst})$ is given, provided $R\subseteq T$
and the third and the fourth homology groups of $R/R\cap S$ are torsion groups.


title:
Implicit-explicit, realizability-preserving first-order scheme for
  moment models with Lipschitz-continuous source terms

abstract:
  We derive an implicit-explicit (IMEX), realizability-preserving first-order
scheme for moment models with Lipschitz-continuous source terms. In contrast to
fully-explicit schemes the time step does not depend on the physical
parameters, removing the stiffness from the system. Furthermore, a wider class
of collision operators (e.g. the Laplace-Beltrami operator) can be used. The
derived scheme is applied to minimum-entropy models.


title: Measuring weak lensing correlations of Type Ia Supernovae

abstract:
  We study the feasibility of detecting weak lensing spatial correlations
between Supernova (SN) Type Ia magnitudes with present (Dark Energy Survey,
DES) and future (Large Synoptic Survey Telescope, LSST) surveys. We investigate
the angular auto-correlation function of SN magnitudes (once the background
cosmology has been subtracted) and cross-correlation with galaxy catalogues. We
examine both analytical and numerical predictions, the latter using simulated
galaxy catalogues from the MICE Grand Challenge Simulation. We predict that we
will be unable to detect the SN auto-correlation in DES, while it should be
detectable with the LSST SN deep fields (15,000 SNe on 70 deg^2) at ~6sigma
level of confidence (assuming 0.15 magnitudes of intrinsic dispersion). The
SN-galaxy cross-correlation function will deliver much higher signal-to-noise,
being detectable in both surveys with an integrated signal-to-noise of ~100 (up
to 30 arcmin separations). We predict joint constraints on the matter density
parameter (Omega_m) and the clustering amplitude (sigma_8) by fitting the
auto-correlation function of our mock LSST deep fields. When assuming a
Gaussian prior for Omega_m, we can achieve a 25% measurement of sigma_8 from
just these LSST supernovae (assuming 0.15 magnitudes of intrinsic dispersion).
These constraints will improve significantly if the intrinsic dispersion of SNe
Ia can be reduced.


title:
Double parton scattering in the ultraviolet: addressing the double
  counting problem

abstract:
  An important question in the theory of double parton scattering is how to
incorporate the possibility of the parton pairs being generated perturbatively
via $1 \to 2$ splitting into the theory, whilst avoiding double counting with
single parton scattering loop corrections. Here, we describe a consistent
approach for solving this problem, which retains the notion of double parton
distributions (DPDs) for individual hadrons. Further, we discuss the
construction of appropriate model DPDs in our framework, and the use of these
to compute the DPS part, presenting DPS 'luminosities' from our model DPDs for
a few sample cases.


title:
Precise measurement of the $e^+e^-\to \pi^+\pi^-J/\psi$ cross section at
  center-of-mass energies from 3.77 to 4.60 GeV

abstract:
  The cross section for the process $e^+e^-\to \pi^+\pi^-J/\psi$ is measured
precisely at center-of-mass energies from 3.77 to 4.60~GeV using 9~fb$^{-1}$ of
data collected with the BESIII detector operating at the BEPCII storage ring.
Two resonant structures are observed in a fit to the cross section. The first
resonance has a mass of $(4222.0\pm 3.1\pm 1.4)$~MeV/$c^2$ and a width of
$(44.1\pm 4.3\pm 2.0)$~MeV, while the second one has a mass of $(4320.0\pm 10.4
\pm 7.0)$~MeV/$c^2$ and a width of $(101.4^{+25.3}_{-19.7}\pm 10.2)$~MeV, where
the first errors are statistical and second ones are systematic. The first
resonance agrees with the $Y(4260)$ resonance reported by previous experiments.
The precision of its resonant parameters is improved significantly. The second
resonance is observed in $e^+e^-\to \pi^+\pi^-J/\psi$ for the first time. The
statistical significance of this resonance is estimated to be larger than
$7.6\sigma$. The mass and width of the second resonance agree with the
$Y(4360)$ resonance reported by the $BABAR$ and Belle experiments within
errors. Finally, the $Y(4008)$ resonance previously observed by the Belle
experiment is not confirmed in the description of the BESIII data.


title:
Interval Enclosures of Upper Bounds of Roundoff Errors using
  Semidefinite Programming

abstract:
  A longstanding problem related to floating-point implementation of numerical
programs is to provide efficient yet precise analysis of output errors.
  We present a framework to compute lower bounds on largest absolute roundoff
errors, for a particular rounding model. This method applies to numerical
programs implementing polynomial functions with box constrained input
variables. Our study is based on three different hierarchies, relying
respectively on generalized eigenvalue problems, elementary computations and
semidefinite programming (SDP) relaxations. This is complementary of
over-approximation frameworks, consisting of obtaining upper bounds on the
largest absolute roundoff error. Combining the results of both frameworks
allows to get enclosures for upper bounds on roundoff errors.
  The under-approximation framework provided by the third hierarchy is based on
a new sequence of convergent robust SDP approximations for certain classes of
polynomial optimization problems. Each problem in this hierarchy can be solved
exactly via SDP. By using this hierarchy, one can provide a monotone
non-decreasing sequence of lower bounds converging to the absolute roundoff
error of a program implementing a polynomial function, applying for a
particular rounding model.
  We investigate the efficiency and precision of our method on non-trivial
polynomial programs coming from space control, optimization and computational
biology.


title: Sub- and super-luminal light propagation using a Rydberg state

abstract:
  We present a theoretical study to investigate sub- and super-luminal light
propagation in a rubidium atomic system consisting of a Rydberg state by using
density matrix formalism. The analysis is performed in a 4-level vee+ladder
system interacting with a weak probe, and strong control and switching fields.
The dispersion and absorption profiles are shown for stationary atoms as well
as for moving atoms by carrying out Doppler averaging at room temperature. We
also present the group index variation with control Rabi frequency and observe
that a transparent medium can be switched from sub- to super-luminal
propagation in the presence of switching field. Finally, the transient response
of the medium is discussed, which shows that the considered 4-level scheme has
potential applications in absorptive optical switching.


title:
Creation and transfer of non-classical states of motion using Rydberg
  dressing of atoms in a lattice

abstract:
  We theoretically investigate the manipulation of the motional states of
trapped ground-state atoms using Rydberg dressing via nonresonant laser fields.
The forces resulting from Rydberg-state interaction between dressed neighboring
atoms in an array of microtraps or an optical lattice can strongly couple their
motion. We show that intensity modulation of the dressing field allows to
squeeze the relative motion of a pair of atoms and generate non-classical
mechanical states. Extending this pairwise scheme to one-dimensional chains
provides flexible control over the mechanical degrees of freedom of the whole
system. We illustrate our findings with protocols to manipulate all motional
degrees of freedom of a pair of atoms and create entangled states. We also
present a method to transfer non-classical correlations along an atomic chain
of nontrivial length. The long-lived nature of motional states, together with
the high tunability of Rydberg dressing, makes our proposal feasible for
current experimental setups.


title: Field-induced spin-density wave beyond hidden order in URu2Si2

abstract:
  URu2Si2 is one of the most enigmatic strongly-correlated-electron systems and
offers a fertile testing ground for new concepts in condensed matter science.
In spite of >30 years of intense research, no consensus on the order parameter
of its low-temperature hidden-order phase exists. A strong magnetic field
transforms the hidden order into magnetically-ordered phases, whose order
parameter has also been defying experimental observation. Here, thanks to an
instrumentation breakthrough in high-field neutron scattering, we identify the
field-induced phases of URu2Si2 as a spin-density-wave state with wavevector k1
= (0.6 0 0). The transition to the spin-density wave represents a unique
touchstone for understanding the hidden-order phase. An intimate relationship
between this magnetic structure, the magnetic fluctuations, and the Fermi
surface is emphasized, calling for dedicated band structure calculations.


title: Probing the primordial Universe with MeerKAT and DES

abstract:
  It is usually assumed that we will need to wait until next-generation surveys
like Euclid, LSST and SKA, in order to improve on the current best constraints
on primordial non-Gaussianity from the Planck experiment. We show that two
contemporary surveys, with the SKA precursor MeerKAT and the Dark Energy Survey
(DES), can be combined using the multi-tracer technique to deliver an accuracy
on measurement of $f_{\rm NL}$ that is up to three times better than Planck.


title:
Recovering the Brownian Coalescent Point Process from the Kingman
  Coalescent by Conditional Sampling

abstract:
  We consider a continuous population whose dynamics is described by the
standard stationary Fleming-Viot process, so that the genealogy of $n$
uniformly sampled individuals is distributed as the Kingman $n$-coalescent. In
this note, we study some genealogical properties of this population when the
sample is conditioned to fall entirely into a subpopulation with most recent
common ancestor (MRCA) shorter than $\varepsilon$. First, using the comb
representation of the total genealogy (Lambert & Uribe Bravo 2016), we show
that the genealogy of the descendance of the MRCA of the sample on the
timescale $\varepsilon$ converges as $\varepsilon\to 0$. The limit is the
so-called Brownian coalescent point process (CPP) stopped at an independent
Gamma random variable with parameter $n$, which can be seen as the genealogy at
a large time of the total population of a rescaled critical birth-death
process, biased by the $n$-th power of its size. Secondly, we show that in this
limit the coalescence times of the $n$ sampled individuals are i.i.d. uniform
random variables in $(0,1)$. These results provide a coupling between two
standard models for the genealogy of a random exchangeable population: the
Kingman coalescent and the Brownian CPP.


title: Fueter's theorem for monogenic functions in biaxial symmetric domains

abstract:
  In this paper we generalize the result on Fueter's theorem from [10] by
Eelbode et al. to the case of monogenic functions in biaxially symmetric
domains. To obtain this result, Eelbode et al. used representation theory
methods but their result also follows from a direct calculus we established in
our paper [21]. In this paper we first generalize [21] to the biaxial case and
derive the main result from that.


title: Multi-level Simulation of Internet of Things on Smart Territories

abstract:
  In this paper, a methodology is presented and employed for simulating the
Internet of Things (IoT). The requirement for scalability, due to the possibly
huge amount of involved sensors and devices, and the heterogeneous scenarios
that might occur, impose resorting to sophisticated modeling and simulation
techniques. In particular, multi-level simulation is regarded as a main
framework that allows simulating large-scale IoT environments while keeping
high levels of detail, when it is needed. We consider a use case based on the
deployment of smart services in decentralized territories. A two level
simulator is employed, which is based on a coarse agent-based, adaptive
parallel and distributed simulation approach to model the general life of
simulated entities. However, when needed a finer grained simulator (based on
OMNeT++) is triggered on a restricted portion of the simulated area, which
allows considering all issues concerned with wireless communications. Based on
this use case, it is confirmed that the ad-hoc wireless networking technologies
do represent a principle tool to deploy smart services over decentralized
countrysides. Moreover, the performance evaluation confirms the viability of
utilizing multi-level simulation for simulating large scale IoT environments.


title: Near-membrane refractometry using supercritical angle fluorescence

abstract:
  Total internal reflection fluorescence (TIRF) microscopy and its variants are
key technologies for visualizing the dynamics of single molecules or organelles
in live cells. Yet, truely quantitative TIRF remains problematic. One unknown
hampering the interpretation of evanescent-wave excited fluorescence
intensities is the undetermined cell refractive index (RI). Here, we use a
combination of TIRF excitation and supercritical angle fluorescence emission
detection to directly mea-sure the average RI in the 'footprint' region of the
cell, during imaging. Our RI measurement is based on the determination on a
back-focal plane image of the critical angle separating supercritical and
undercritial fluorescence emission components. We validate our method by
imaging mouse embryonic fibroblasts. By targeting various dyes and
fluorescent-protein chimerae to vesicles, the plasma membrane as well as
mitochondria and the ER, we demonstrate local RI measurements with subcellular
resolution on a standard TIRF microscope with a removable Bertrand lens as the
only modification. Our tech-nique has important applications for imaging axial
vesicle dynamics, mitochondrial energy state or detecting cancer cells.


title:
A blueprint for a simultaneous test of quantum mechanics and general
  relativity in a space-based quantum optics experiment

abstract:
  In this paper we propose an experiment designed to observe a
general-relativistic effect on single photon interference. The experiment
consists of a folded Mach-Zehnder interferometer, with the arms distributed
between a single Earth orbiter and a ground station. By compensating for other
degrees of freedom and the motion of the orbiter, this setup aims to detect the
influence of general relativistic time dilation on a spatially superposed
single photon. The proposal details a payload to measure the required effect,
along with an extensive feasibility analysis given current technological
capabilities.


title: Feasible Interpolation for QBF Resolution Calculi

abstract:
  In sharp contrast to classical proof complexity we are currently short of
lower bound techniques for QBF proof systems. In this paper we establish the
feasible interpolation technique for all resolution-based QBF systems, whether
modelling CDCL or expansion-based solving. This both provides the first general
lower bound method for QBF proof systems as well as largely extends the scope
of classical feasible interpolation. We apply our technique to obtain new
exponential lower bounds to all resolution-based QBF systems for a new class of
QBF formulas based on the clique problem. Finally, we show how feasible
interpolation relates to the recently established lower bound method based on
strategy extraction.


title: On the ranks of elliptic curves with isogenies

abstract:
  In recent years, the question of whether the ranks of elliptic curves defined
over $\mathbb{Q}$ are unbounded has garnered much attention. One can create
refined versions of this question by restricting one's attention to elliptic
curves over $\mathbb{Q}$ with a certain algebraic structure, e.g., with a
rational point of a given order. In an attempt to gather data about such
questions, we look for examples of elliptic curves over $\mathbb{Q}$ with an
$n$-isogeny and rank as large as possible. To do this, we use existing
techniques due to Rogers, Rubin, Silverberg, and Nagao and develop a new
technique (based on an observation made by Mazur) that is more computationally
feasible when the naive heights of the elliptic curves are large.


title: Graph spectral characterisation of the XY model on complex networks

abstract:
  There is recent evidence that the $XY$ spin model on complex networks can
display three different macroscopic states in response to the topology of the
network underpinning the interactions of the spins. In this work, we present a
novel way to characterise the macroscopic states of the $XY$ spin model based
on the spectral decomposition of time series using topological information
about the underlying networks. We use three different classes of networks to
generate time series of the spins for the three possible macroscopic states. We
then use the temporal Graph Signal Transform technique to decompose the time
series of the spins on the eigenbasis of the Laplacian. From this
decomposition, we produce spatial power spectra, which summarise the activation
of structural modes by the non-linear dynamics, and thus coherent patterns of
activity of the spins. These signatures of the macroscopic states are
independent of the underlying networks and can thus be used as universal
signatures for the macroscopic states. This work opens new avenues to analyse
and characterise dynamics on complex networks using temporal Graph Signal
Analysis.


title: RenderGAN: Generating Realistic Labeled Data

abstract:
  Deep Convolutional Neuronal Networks (DCNNs) are showing remarkable
performance on many computer vision tasks. Due to their large parameter space,
they require many labeled samples when trained in a supervised setting. The
costs of annotating data manually can render the use of DCNNs infeasible. We
present a novel framework called RenderGAN that can generate large amounts of
realistic, labeled images by combining a 3D model and the Generative
Adversarial Network framework. In our approach, image augmentations (e.g.
lighting, background, and detail) are learned from unlabeled data such that the
generated images are strikingly realistic while preserving the labels known
from the 3D model. We apply the RenderGAN framework to generate images of
barcode-like markers that are attached to honeybees. Training a DCNN on data
generated by the RenderGAN yields considerably better performance than training
it on various baselines.


title: Exploring the Long-Term Evolution of GRS 1915+105

abstract:
  Among the population of known galactic black hole X-ray binaries, GRS
1915+105 stands out in multiple ways. It has been in continuous outburst since
1992, and has shown a wide range of different states that can be distinguished
by their timing and spectral properties. These states, also observed in IGR
J17091-3624, have in the past been linked to accretion dynamics. Here, we
present the first comprehensive study into the long-term evolution of GRS
1915+105, using the entire data set observed with RXTE over its sixteen-year
lifetime. We develop a set of descriptive features allowing for automatic
separation of states, and show that supervised machine learning in the form of
logistic regression and random forests can be used to efficiently classify the
entire data set. For the first time, we explore the duty cycle and time
evolution of states over the entire sixteen-year time span, and find that the
temporal distribution of states has significantly changed over the span of the
observations. We connect the machine classification with physical
interpretations of the phenomenology in terms of chaotic and stochastic
processes.


title:
Parent Hamiltonians for lattice Halperin states from free-boson
  conformal field theories

abstract:
  We introduce a family of many-body quantum states that describe interacting
spin one-half hard-core particles with bosonic or fermionic statistics on
arbitrary one- and two-dimensional lattices. The wave functions at lattice
filling fraction $\nu=2/(2m+1)$ are derived from deformations of the
Wess-Zumino-Witten model $\mathfrak{su}(3)_1$ and are related to the
$(m+1,m+1,m)$ Halperin fractional quantum Hall states. We derive long-range
SU(2) invariant parent Hamiltonians for these states which in two dimensions
are chiral $t$-$J$-$V$ models with additional three-body interaction terms. In
one dimension we obtain a generalisation to open chains of a periodic
inverse-square $t$-$J$-$V$ model proposed in [Z. N. C. Ha and F. D. M. Haldane,
Phys. Rev. B $\mathbf{46}$, 9359 (1992)]. We observe that the gapless
low-energy spectrum of this model and its open-boundary generalisation can be
described by rapidity sets with the same generalised Pauli exclusion principle.
A two-component compactified free boson conformal field theory is identified
that has the same central charge and scaling dimensions as the periodic bosonic
inverse-square $t$-$J$-$V$ model.


title:
Quantum correlations and entanglement in a model comprised of a short
  chain of nonlinear oscillators

abstract:
  We discuss a model comprised of a chain of three Kerr-like nonlinear
oscillators pumped by two modes of external coherent field. We show that the
system can be treated as nonlinear quantum scissors and behave as a three-qubit
model. For such situation, different types of tripartite entangled states can
be generated, even when damping effects are present in the system. Some amount
of such entanglement can survive even in a long-time limit. The flow of
bipartite entanglement between subsystems of the model and relations among
first-order correlations, second-order correlations, and the entanglement are
discussed.


title: Phi-Entropic Measures of Correlation

abstract:
  A measure of correlation is said to have the tensorization property if it is
unchanged when computed for i.i.d.\ copies. More precisely, a measure of
correlation between two random variables $(X, Y)$ denoted by $\rho(X, Y)$, has
the tensorization property if $\rho(X^n, Y^n)=\rho(X, Y)$ where $(X^n, Y^n)$ is
$n$ i.i.d.\ copies of $(X, Y)$.Two well-known examples of such measures are the
maximal correlation and the hypercontractivity ribbon (HC~ribbon). We show that
the maximal correlation and HC ribbons are special cases of $\Phi$-ribbon,
defined in this paper for any function $\Phi$ from a class of convex functions
($\Phi$-ribbon reduces to HC~ribbon and the maximal correlation for special
choices of $\Phi$). Any $\Phi$-ribbon is shown to be a measures of correlation
with the tensorization property. We show that the $\Phi$-ribbon also
characterizes the $\Phi$-strong data processing inequality constant introduced
by Raginsky. We further study the $\Phi$-ribbon for the choice of $\Phi(t)=t^2$
and introduce an equivalent characterization of this ribbon.


title: Linear perturbation of the Yamabe problem on manifolds with boundary

abstract:
  We build blowing-up solutions for linear perturbation of the Yamabe problem
on manifolds with boundary, provided the dimension of the manifold is n>6 and
the trace-free part of the second fundamental form is non-zero everywhere on
the boundary.


title:
Mechanically Proving Determinacy of Hierarchical Block Diagram
  Translations

abstract:
  Hierarchical block diagrams (HBDs) are at the heart of embedded system design
tools, including Simulink. Numerous translations exist from HBDs into languages
with formal semantics, amenable to formal verification. However, none of these
translations has been proven correct, to our knowledge. We present in this
paper the first mechanically proven HBD translation algorithm. The algorithm
translates HBDs into an algebra of terms with three basic composition
operations (serial, parallel, and feedback). In order to capture various
translation strategies resulting in different terms achieving different
tradeoffs, the algorithm is nondeterministic. Despite this, we prove its
semantic determinacy: for every input HBD, all possible terms that can be
generated by the algorithm are semantically equivalent. We apply this result to
show how three Simulink translation strategies introduced previously can be
formalized as determinizations of the algorithm, and derive that these
strategies yield semantically equivalent results (a question left open in
previous work). All results are formalized and proved in the Isabelle
theorem-prover.


title: On composition of Segal-Bargmann transforms

abstract:
  We introduce and discuss some basic properties of some integral transforms in
the framework of specific functional Hilbert spaces, the holomorphic
Bargmann-Fock spaces on $\mathbb{C}$ and $\mathbb{C}^2$ and the slice
hyperholomorphic Bargmann-Fock space on $\mathbb{H}$. The first one is a
natural integral transform mapping isometrically the standard Hilbert space on
the real line into the two-dimensional Bargmann-Fock space. It is obtained as
composition of the one and two dimensional Segal-Bargmann transforms and
reduces further to an extremely integral operator that looks like a composition
operator of the one-dimensional Segal-Bargmann transform with a specific
symbol. We study its basic properties, including the identification of its
image and the determination of a like-left inverse defined on the whole
two-dimensional Bargmann-Fock space. We also examine their combination with the
Fourier transform which lead to special integral transforms connecting the
two-dimensional Bargmann-Fock space and its analogue on the complex plane. We
also investigate the relationship between special subspaces of the
two-dimensional Bargmann-Fock space and the slice-hyperholomorphic one on the
quaternions by introducing appropriate integral transforms. We identify their
image and their action on the reproducing kernel.


title: J-fusion frame for Krein spaces

abstract:
  In this article we introduce the notion of $J$-fusion frame for a Krein space
$\mathbb{K}$. We relate this new concept with fusion frames for Hilbert spaces
and also with $J$-frames for Krein spaces. We also approximate $J$-fusion frame
bounds of a $J$-fusion frame by the upper and lower bounds of the synthesis
operator. Finally we address the problem of characterizing those bounded linear
operators in $\mathbb{K}$ for which the image of $J$-fusion frame is also a
$J$-fusion frame.


title:
Derivation Hom-Lie 2-algebras and non-abelian extensions of Hom-Lie
  algebras

abstract:
  In this paper, we introduce the notion of a derivation of a Hom-Lie algebra
and construct the corresponding strict Hom-Lie 2-algebra, which is called the
derivation Hom-Lie 2-algebra. As applications, we study non-abelian extensions
of Hom-Lie algebras. We show that iso- morphism classes of diagonal non-abelian
extensions of a Hom-Lie algebra g by a Hom-Lie algebra h are in one-to-one
correspondence with homotopy classes of morphisms from g to the derivation
Hom-Lie 2-algebra DER(h).


title: Fast-slow vector fields of reaction-diffusion systems

abstract:
  A geometrically invariant concept of fast-slow vector fields perturbed by
transport terms (describing molecular diffusion processes) is proposed in this
paper. It is an extension of our concept of singularly perturbed vector fields
to reaction-diffusion systems. Fast-slow vector fields can be represented
locally as "singularly perturbed systems of PDE". The paper focuses on possible
ways of original models decomposition to fast and slow subsystems. We
demonstrate that transport terms can be neglected (under reasonable physical
assumptions) for fast subsystem. A method of analysis of slow subsystem as an
evolution of singularly perturbed profiles along slow invariant manifolds was
discussed in our previous work \cite{BCMGM2016}.
  This paper is motivated by an algorithm of reaction-diffusion manifolds
(REDIM) \cite{BM2007,BM2009,MB2011}. It can be considered as its theoretical
justification extending it from a practical algorithm to a robust computational
procedure under some reasonable physical assumptions. A practical application
of the proposed algorithm for numerical treatment of reaction-diffusion systems
is demonstrated.


title:
Frustrated spin chain physics near the Majumdar-Ghosh point in
  szenicsite Cu$_3$(MoO$_4$)(OH)$_4$

abstract:
  In this joint experimental and theoretical work magnetic properties of the
Cu$^{2+}$ mineral szenicsite Cu$_3$(MoO$_4$)(OH)$_4$ are investigated. This
compound features isolated triple chains in its crystal structure, where the
central chain involves an edge-sharing geometry of the CuO$_4$ plaquettes,
while the two side chains feature a corner-sharing zig-zag geometry. The
magnetism of the side chains can be described in terms of antiferromagnetic
dimers with a coupling larger than 200 K. The central chain was found to be a
realization of the frustrated antiferromagnetic $J_1$-$J_2$ chain model with
$J_1\simeq 68$ K and a sizable second-neighbor coupling $J_2$. The central and
side chains are nearly decoupled owing to interchain frustration. Therefore,
the low-temperature behavior of szenicsite should be entirely determined by the
physics of the central frustrated $J_1$-$J_2$ chain. Our heat-capacity
measurements reveal an accumulation of entropy at low temperatures and suggest
a proximity of the system to the Majumdar-Ghosh point of the antiferromagnetic
$J_1$-$J_2$ spin chain, $J_2/J_1=0.5$.


title:
Local $C^{1,\beta}$-regularity at the boundary of two dimensional
  sliding almost minimal sets in $\mathbb{R}^3$

abstract:
  In this paper, we will give a $C^{1,\beta}$-regularity result on the boundary
for two dimensional sliding almost minimal sets in $\mathbb{R}^3$. This effect
may lead to the existence of a solution to the Plateau problem with sliding
boundary conditions proposed by Guy David in \cite{David:2014p} in the case
that the boundary is a 2-dimensional smooth manifold.


title: The Polytope-Collision Problem

abstract:
  The Orbit Problem consists of determining, given a matrix $A\in
\mathbb{R}^{d\times d}$ and vectors $x,y\in \mathbb{R}^d$, whether there exists
$n\in \mathbb{N}$ such that $A^n=y$. This problem was shown to be decidable in
a seminal work of Kannan and Lipton in the 1980s. Subsequently, Kannan and
Lipton noted that the Orbit Problem becomes considerably harder when the target
$y$ is replaced with a subspace of $\mathbb{R}^d$. Recently, it was shown that
the problem is decidable for vector-space targets of dimension at most three,
followed by another development showing that the problem is in PSPACE for
polytope targets of dimension at most three. In this work, we take a dual look
at the problem, and consider the case where the initial vector $x$ is replaced
with a polytope $P_1$, and the target is a polytope $P_2$. Then, the question
is whether there exists $n\in \mathbb{N}$ such that $A^n P_1\cap P_2\neq
\emptyset$. We show that the problem can be decided in PSPACE for dimension at
most three. As in previous works, decidability in the case of higher dimensions
is left open, as the problem is known to be hard for long-standing
number-theoretic open problems.
  Our proof begins by formulating the problem as the satisfiability of a
parametrized family of sentences in the existential first-order theory of
real-closed fields. Then, after removing quantifiers, we are left with
instances of simultaneous positivity of sums of exponentials. Using techniques
from transcendental number theory, and separation bounds on algebraic numbers,
we are able to solve such instances in PSPACE.


title:
Role of $\sigma$ exchange in the $\gamma p\to \phi p$ process and
  scaling with the $f_1$ axial vector meson from a Reggeized model

abstract:
  We investigate the role driven by the scalar meson $\sigma$ exchange in the
photoproduction of the vector meson $\phi$(1020) off a proton by using a
Reggeized model. Based on the $\pi^0(135)+\sigma(500)+f_2(1270)$+Pomeron
exchanges, we demonstrate that the $\sigma$ exchange plays the role to
reproduce the bump structure at the forward angle in the differential cross
section as well as the peaking behavior in the total cross section observed in
the CLAS Collaboration. We also discuss the possible observation of the scaled
cross section $s^7d\sigma /dt$ at the production angle $\theta=90^{\circ}$ from
the CLAS data. It is found that the axial vector meson $f_1(1285)$ exchange
with the trajectory $\alpha_{f_1}(t)=0.028\,t+0.9\pm0.2$ arising from the axial
anomaly of the QCD vacuum plays the role to clarify the scaling up to 5 GeV.


title: On the primitivity of PRESENT and other lightweight ciphers

abstract:
  We provide two sufficient conditions to guarantee that the round functions of
a translation based cipher generate a primitive group. Furthermore, under the
same hypotheses, and assuming that a round of the cipher is strongly proper and
consists of m-bit S-Boxes, with m = 3; 4 or 5, we prove that such a group is
the alternating group. As an immediate consequence, we deduce that the round
functions of some lightweight translation based ciphers, such as the PRESENT
cipher, generate the alternating group.


title: Hadron yields, the chemical freeze-out and the QCD phase diagram

abstract:
  We present the status of the chemical freeze-out, determined from fits of
hadron yields with the statistical hadronization (thermal) model, with focus on
the data at the LHC. A description of the yields of hadrons containing light
quarks as well as the application of the model for the production of the
J/$\psi$ meson is presented. The implications for the QCD phase diagram are
discussed.


title:
Search for eta-mesic 4He in the dd->3He n pi0 and dd->3He p pi-
  reactions with the WASA-at-COSY facility

abstract:
  The search for 4He-eta bound states was performed with the WASA-at-COSY
facility via the measurement of the excitation function for the dd->3He n pi0
and dd->3He p pi- processes. The beam momentum was varied continuously between
2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd->4He
eta reaction ranging from Q=-70 MeV to Q=30 MeV. The luminosity was determined
based on the dd->3He n reaction and quasi-free proton-proton scattering via
dd->pp n_spectator n_spectator reactions. The excitation functions determined
independently for the measured reactions do not reveal a structure which could
be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the
total cross sections for the bound state production and decay in
dd->(4He-eta)_bound->3He n pi0 and dd->(4He-eta)_bound->3He p pi- processes
were determined taking into account the isospin relation between both the
channels considered. The results of the analysis depend on the assumptions of
the N* momentum distribution in the anticipated mesic-4He. Assuming as in the
previous works, that this is identical with the distribution of nucleons bound
with 20 MeV in 4He, we determined that (for the mesic bound state width in the
range from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about
3 nb and about 6 nb for npi0 and ppi- channels, respectively. However, based on
the recent theoretical findings of the N*(1535) momentum distribution in the
N*-3He nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector
acceptance decreases and hence the corresponding upper limits are 5 nb and 10
nb for npi0 and ppi- channels respectively.


title:
Properties of quantum stochastic walks from the asymptotic scaling
  exponent

abstract:
  This work focuses on the study of quantum stochastic walks, which are a
generalization of coherent, i. e. unitary quantum walks. Our main goal is to
present a measure of a coherence of the walk. To this end, we utilize the
asymptotic scaling exponent of the second moment of the walk i. e. of the mean
squared distance covered by a walk. As the quantum stochastic walk model
encompasses both classical random walks and quantum walks, we are interested
how the continuous change from one regime to the other influences the
asymptotic scaling exponent. Moreover this model allows for behavior which is
not found in any of the previously mentioned model -- the model with global
dissipation. We derive the probability distribution for the walker, and
determine the asymptotic scaling exponent analytically, showing that ballistic
regime of the walk is maintained even at large dissipation strength.


title:
Molecular dynamics simulation of twin boundary effect on deformation of
  Cu nanopillars

abstract:
  Molecular dynamics simulations performed on <110> Cu nanopillars revealed
significant difference in deformation behavior of nanopillars with and without
twin boundary. The plastic deformation in single crystal Cu nanopillar without
twin boundary was dominated by twinning, whereas the introduction of twin
boundary changed the deformation mode from twinning to slip consisting of
leading partial followed by trailing partial dislocations. This difference in
deformation behavior has been attributed to the formation of stair-rod
dislocation and its dissociation in the twinned nanopillars.


title: Improved Pena-Rodriguez Portmanteau Test

abstract:
  Several problems with the diagnostic check suggested by Pena and Rodriguez
[2002. A powerful portmanteau test of lack of fit for time series. J. Amer.
Statist. Assoc. 97, 601-610.] are noted and an improved Monte-Carlo version of
this test is suggested. It is shown that quite often the test statistic
recommended by Pena and Rodriguez [2002. A powerful portmanteau test of lack of
fit for time series. J. Amer. Statist. Assoc. 97, 601-610.] may not exist and
their asymptotic distribution of the test does not agree with the suggested
gamma approximation very well if the number of lags used by the test is small.
It is shown that the convergence of this test statistic to its asymptotic
distribution may be quite slow when the series length is less than 1000 and so
a Monte-Carlo test is recommended. Simulation experiments suggest the
Monte-Carlo test is usually more powerful than the test given by Pena and
Rodriguez [2002. A powerful portmanteau test of lack of fit for time series. J.
Amer. Statist. Assoc. 97, 601-610.] and often much more powerful than the
Ljung-Box portmanteau test. Two illustrative examples of enhanced diagnostic
checking with the Monte-Carlo test are given.


title: Asymmetric Doob inequalities in continuous time

abstract:
  The present paper is devoted to the second part of our project on asymmetric
maximal inequalities, where we consider martingales in continuous time. Let
$(\mathcal M,\tau)$ be a noncommutative probability space equipped with a
continuous filtration of von Neumann subalgebras $(\mathcal M_t)_{0\leq
t\leq1}$ whose union is weak-$*$ dense in $\mathcal{M}$. Let $\mathcal E_t$
denote the corresponding family of conditional expectations. As for discrete
filtrations, we shall prove that for $1 < p < 2$ and $x \in L_p(\mathcal
M,\tau)$ one can find $a, b \in L_p(\mathcal M,\tau)$ and contractions $u_t,
v_t \in \mathcal M$ such that $$\mathcal E_t(x) = a u_t + v_t b \quad
\mbox{and} \quad \max \big\{ \|a\|_p, \|b\|_p \big\} \le c_p \|x\|_p.$$
Moreover, $a u_t$ and $v_t b$ converge in the row/column Hardy spaces $\mathcal
H_p^r(\mathcal M)$ and $\mathcal H_p^c(\mathcal M)$ respectively. We also
confirm in the continuous setting the validity of related asymmetric maximal
inequalities which we recently found for discrete filtrations, including $p=1$.
As for other results in noncommutative martingale theory, the passage from
discrete to continuous index is quite technical and requires genuinely new
methods. Our approach towards asymmetric maximal inequalities is based on
certain construction of conditional expectations for a sequence of projective
systems of $L_p$-modules. The convergence in $\mathcal H_p^r(\mathcal M)$ and
$\mathcal H_p^c(\mathcal M)$ also imposes new algebraic atomic decompositions.


title:
Information Dropout: Learning Optimal Representations Through Noisy
  Computation

abstract:
  The cross-entropy loss commonly used in deep learning is closely related to
the defining properties of optimal representations, but does not enforce some
of the key properties. We show that this can be solved by adding a
regularization term, which is in turn related to injecting multiplicative noise
in the activations of a Deep Neural Network, a special case of which is the
common practice of dropout. We show that our regularized loss function can be
efficiently minimized using Information Dropout, a generalization of dropout
rooted in information theoretic principles that automatically adapts to the
data and can better exploit architectures of limited capacity. When the task is
the reconstruction of the input, we show that our loss function yields a
Variational Autoencoder as a special case, thus providing a link between
representation learning, information theory and variational inference. Finally,
we prove that we can promote the creation of disentangled representations
simply by enforcing a factorized prior, a fact that has been observed
empirically in recent work. Our experiments validate the theoretical intuitions
behind our method, and we find that information dropout achieves a comparable
or better generalization performance than binary dropout, especially on smaller
models, since it can automatically adapt the noise to the structure of the
network, as well as to the test sample.


title:
New insights on the formation of supersaturated solid solutions in the
  Cu Cr system deformed by high pressure torsion

abstract:
  In the Cu Cr system, the formation of supersaturated solid solutions can be
obtained by severe plastic deformation. Energy dispersive synchrotron
diffraction measurements on as deformed Cu Cr samples as a function of the
applied strain during deformation confirm the formation of supersaturated solid
solutions in this usually immiscible system. Due to evaluation of the
diffraction data by a newly developed energy dispersive Rietveld program,
lattice parameter and microstructural parameters such as domain size and
microstrain are determined for as deformed as well as annealed samples. The
obtained information is used to deepen the understanding of the microstructural
evolution and the formation of supersaturated solid solutions during severe
plastic deformation. Complimentary transmission electron microscopy
investigations are furthermore performed to characterize the evolving
microstructure in detail. After annealing at elevated temperatures, the formed
solid solutions decompose. Compared to the as deformed state, an enhanced
hardness combined with a high thermal stability is observed. Possible
mechanisms for the enhanced hardness are discussed.


title:
Disjointness preserving $\mathrm{C}_0$-semigroups and local operators on
  ordered Banach spaces

abstract:
  We generalize results concerning $\mathrm{C}_0$-semigroups on Banach lattices
to a setting of ordered Banach spaces. We prove that the generator of a
disjointness preserving $\mathrm{C}_0$-semigroup is local. Some basic
properties of local operators are also given. We investigate cases where local
operators generate local $\mathrm{C}_0$-semigroups, by using Taylor series or
Yosida approximations. As norms we consider regular norms and show that bands
are closed with respect to such norms. Our proofs rely on the theory of
embedding pre-Riesz spaces in vector lattices and on corresponding extensions
of regular norms.


title: Circular pentagons and real solutions of Painleve VI equations

abstract:
  We study real solutions of a class of Painleve VI equations. To each such
solution we associate a geometric object, a one-parametric family of circular
pentagons. We describe an algorithm which permits to compute the numbers of
zeros, poles, 1-points and fixed points of the solution on the interval x>1 and
their mutual position. The monodromy of the associated linear equation and
parameters of the Painleve VI equation are easily recovered from the family of
pentagons.


title: Neutron star properties and the equation of state for its core

abstract:
  Few unified equations of state for neutron star matter where core and crust
are described using the same nuclear model are available. However the use of
non-unified equations of state with a simplified matching between the crust and
the core has been shown to introduce uncertainties in the radius determination
which can be larger than the expected precision of the next generation of X-ray
satellites.
  We aim at eliminating the dependence of the radius and mass of neutron staron
the detailed model for the crust and on the crust-core matching procedure. We
solve the approximate equations of the hydrostatic equilibrium for the crust of
neutron stars obtaining a precise formula for the radius which depends only on
the core mass and radius, and on the baryon chemical potential at the
core-crust interface and on the crust surface. For a fully accreted crust one
needs additionally the value of the total deep crustal heating per one accreted
nucleon.
  For typical neutron star masses the approximate approach allows to determine
the neutron star radius with an error ~0.1% (~ 10 m, equivalent to a 1%
inaccuracy in the crust thickness).
  The formalism applies to neutron stars with a catalyzed or a fully accreted
crust. The difference in the neutron star radius between the two models is
proportional to the total energy release due to deep crustal heating.
  For a given model of dense matter describing the neutron star core, the
radius of a neutron star can be accurately determined independently of the
crust model with a precision much better than the ~5% one expected from the
next generation of X-ray satellites. This allows to circumvent the problem of
the radius uncertainty which may arise when non-unified equations of state for
the crust and the core are used.


title: On some divisibility properties of binomial sums

abstract:
  In this paper, we consider two particular binomial sums \begin{align*}
\sum_{k=0}^{n-1}(20k^2+8k+1){\binom{2k}{k}}^5 (-4096)^{n-k-1} \end{align*} and
\begin{align*} \sum_{k=0}^{n-1}(120k^2+34k+3){\binom{2k}{k}}^4\binom{4k}{2k}
65536^{n-k-1}, \end{align*} which are inspired by two series for
$\frac{1}{\pi^2}$ obtained by Guillera. We consider their divisibility
properties and prove that they are divisible by $2n^2 \binom{2n}{n}^2$ for all
integer $n\geq 2$. These divisibility properties are stronger than those
divisibility results found by He, who proved the above two sums are divisible
by $2n \binom{2n}{n}$ with the WZ-method.


title: Out-of-Band Radiation from Large Antenna Arrays

abstract:
  Co-existing wireless systems, which share a common spectrum, need to mitigate
out-of-band (OOB) radiation to avoid excessive interference. For legacy
systems, OOB radiation is well understood and is commonly handled by digital
precompensation techniques. When using large arrays, however, new phenomena and
hardware limitations have to be considered. First, signals can be radiated
directionally, which might focus the OOB radiation. Second, low-complexity
hardware is used for cost reasons, which increases the relative amount of OOB
radiation. Given that massive MIMO and millimeter wave communication rely on
base stations with a large number of antennas, the spatial behavior of OOB
radiation from large arrays will have significant implications for the hardware
requirements of future base stations. We show that, if the OOB radiation is
beamformed, its array gain is never larger than that of the in-band signal. In
many cases, the OOB radiation is close to isotropic even when the in-band
signal is highly directive. With the same total radiated power, the OOB
radiation from large arrays is therefore never more severe than from a legacy
system with the same adjacent-channel-leakage ratio. Further, the OOB radiation
is less detrimental than from a legacy system since the high array gain of the
in-band signal allows large arrays to radiate less total power than legacy
systems. We also show how OOB radiation from large arrays varies with location
in static propagation environments and how these effects vanish when averaged
over the small-scale fading. Since a higher relative amount of OOB radiation
can be tolerated for large arrays, the linearity requirement can be relaxed as
compared to legacy systems. Specifically, less stringent linearity requirements
on each transmitter makes it possible to build large arrays from low-complexity
hardware.


title: Portmanteau Tests for ARMA Models with Infinite Variance

abstract:
  Autoregressive and moving-average (ARMA) models with stable Paretian errors
is one of the most studied models for time series with infinite variance.
Estimation methods for these models have been studied by many researchers but
the problem of diagnostic checking fitted models has not been addressed. In
this paper, we develop portmanteau tests for checking randomness of a time
series with infinite variance and as a diagnostic tool for checking model
adequacy of fitted ARMA models. It is assumed that least-squares or an
asymptotically equivalent estimation method, such as Gaussian maximum
likelihood in the case of AR models, is used. And it is assumed that the
distribution of the innovations is IID stable Paretian. It is seen via
simulation that the proposed portmanteau tests do not converge well to the
corresponding limiting distributions for practical series length so a
Monte-Carlo test is suggested. Simulation experiments show that the proposed
test procedure works effectively. Two illustrative applications to actual data
are provided to demonstrate that an incorrect conclusion may result if the
usual portmanteau test based on the finite variance assumption is used.


title: Research on Life Characteristics of Internet Based on Network Motifs

abstract:
  From biosystem to complex system,the study of life is always an important
area. Inspired by hyper-cycle theory about the evolution of non-life system, we
study the metabolism, self-replication and mutation behavior in the Internet
based on node entity, connection relationship and function subgraph--motif--of
network topology. Firstly a framework of complex network evolution is proposed
to analyze the birth and death phenomena of Internet topology from January 1998
to August 2013. Then we find the Internet metabolism behavior from angle of
node, motif to global topology, i.e. one born node is only added into Internet,
subsequently takes part in the local reconstruction activities. Meanwhile there
are nodes' and motifs' death. In process of the local reconstruction, although
the Internet system replicates motifs repeatedly by adding or removing actions,
the system characteristics and global structure are not destroyed. Statistics
about the motif M3 which is a full connectivity subgraph shows that the process
of its metabolism is fluctuation that causes mutation of Internet. Furthermore
we find that mutation is instinctive reaction of Internet when it's influenced
from inside or outside environment, such as Internet bubble, social network
rising and finance crisis. The behaviors of metabolism, self-replication and
mutation of Internet indicate its life characteristic as a complex artificial
life. And our work will inspire people to study the life-like phenomena of
other complex systems from angle of topology structure.


title: Flowgraph Models and Analysis for Markov Jump Processes

abstract:
  Flowgraph models provide an alternative approach in modeling a multi-state
stochastic process. One of the most widely used stochastic processes that have
many real-world applications especially in actuarial models is the Markov jump
process or continuous- time Markov chain. However, finding waiting time
distributions between any two states in a Markov jump process can be very
difficult. Flowgraph analysis for Markov jump process comprises of modeling the
possible states of the process, the interstates waiting time distribution, and
working on the moment generating function domain to obtain the total waiting
time distribution in form of density or survival function. This paper gives the
theory and computational method of flowgraph analysis, uses it in Markov
process problems, and compares the traditional Markov process construction
method with the flowgraph method to demonstrate the convenience and
practicality of flowgraph analysis.


title:
Phase separation of a supersaturated nanocrystalline Cu Co alloy and its
  influence on thermal stability

abstract:
  The thermal decomposition behavior, the microstructural evolution and its
influence on the mechanical properties of a supersaturated Cu Co solid solution
with ~100 nm average grain size prepared by severe plastic deformation is
investigated under non-isothermal and isothermal annealing conditions. Pure
fine grained Cu and Co exhibit substantial grain growth upon annealing, whereas
the Cu Co alloy is thermally stable at the same annealing temperatures. The
annealed microstructures are studied by independent characterization methods,
including scanning electron microscopy, electron energy loss spectroscopy and
atom probe tomography. The phase separation process in the Cu Co alloy proceeds
by the same mechanism, but on different length scales: a fine scaled spinodal
type decomposition is observed in the grain interior, simultaneously Co and Cu
regions with a larger scale are formed near the grain boundary regions.
Subsequent grain growth at higher annealing temperatures results in a
microstructure consisting of the pure equilibrium phases. Such mechanisms can
be used to tailor nano structures to optimize certain properties.


title: A Generalization of the Minisum and Minimax Voting Methods

abstract:
  In this paper, we propose a family of approval voting-schemes for electing
committees based on the preferences of voters. In our schemes, we calculate the
vector of distances of the possible committees from each of the ballots and,
for a given $ p $-norm, choose the one that minimizes the magnitude of the
distance vector under that norm. The minisum and minimax methods suggested by
previous authors and analyzed extensively in the literature naturally appear as
special cases corresponding to $ p = 1 $ and $ p = \infty, $ respectively.
Supported by examples, we suggest that using a small value of $ p, $ such as 2
or 3, provides a good compromise between the minisum and minimax voting methods
with regard to the weightage given to approvals and disapprovals. For large but
finite $ p, $ our method reduces to finding the committee that covers the
maximum number of voters, and this is far superior to the minimax method which
is prone to ties. We also discuss extensions of our methods to ternary voting.


title: The flow and evolution of ice-sucrose crystal mushes

abstract:
  We study the rheology of suspensions of ice crystals at moderate to high
volume fractions in a sucrose solution in which they are partially soluble; a
model system for a wide class of crystal mushes or slurries. Under step changes
in shear rate, the viscosity changes to a new `relaxed' value over several
minutes, in a manner well fitted by a single exponential. The behavior of the
relaxed viscosity is power-law shear thinning with shear rate, with an exponent
of $-1.76 \pm 0.25$, so that shear stress falls with increasing shear rate. On
longer timescales, the crystals ripen (leading to a falling viscosity) so that
the mean radius increases with time to the power $0.14 \pm 0.07$. We speculate
that this unusually small exponent is due to the interaction of classical
ripening dynamics with abrasion or breakup under flow. We compare the
rheological behavior to mechanistic models based on flow-induced aggregation
and breakup of crystal clusters, finding that the exponents can be predicted
from liquid phase sintering and breakup by brittle fracture.


title:
Wave Deflection and Shifted Refocusing in a Medium Modulated by a
  Superluminal Rectangular Pulse

abstract:
  We explore the problem of scattering in a medium modulated by a superluminal
rectangular pulse, with the pulse modulation realized through transverse
excitations. We solve this problem in the moving frame where the modulation
appears purely temporal, since the solution to a purely temporal modulation is
known. Upon this basis, we use a graphical approach to find the angle and
frequency of the wave scattered by the modulation under oblique incidence. This
study reveals that superluminal modulations deflect plane waves
retro-directively, and refocus cylindrical waves to a shifted point of space
with respect to the original source.


title: On Finiteness of 2- and 3-point Functions and the Renormalisation Group

abstract:
  Two and three point functions of composite operators are analysed with regard
to (logarithmically) divergent contact terms. Using the renormalisation group
of dimensional regularisation it is established that the divergences are
governed by the anomalous dimensions of the operators and the leading
UV-behaviour of the $1/\epsilon$-coefficient. Explicit examples are given by
the $<G^2G^2>$-, $<\Theta \Theta>$-trace of the energy momentum tensor) and
$<\bar q q \bar q q>$- correlators in QCD-like theories. The former two are
convergent when all orders are taken into account but divergent at each order
in perturbation theory implying that the latter and the the $\epsilon \to 0$
limit do not generally commute. Finite correlation functions obey unsubtracted
dispersion relations which is of importance when they are directly related to
physical observables. As a byproduct the $R^2$-anomaly is extended to NNLO
($O(\alpha^5)$) using a recent $<G^2G^2>$-computation.


title: Assessing the Ability of LSTMs to Learn Syntax-Sensitive Dependencies

abstract:
  The success of long short-term memory (LSTM) neural networks in language
processing is typically attributed to their ability to capture long-distance
statistical regularities. Linguistic regularities are often sensitive to
syntactic structure; can such dependencies be captured by LSTMs, which do not
have explicit structural representations? We begin addressing this question
using number agreement in English subject-verb dependencies. We probe the
architecture's grammatical competence both using training objectives with an
explicit grammatical target (number prediction, grammaticality judgments) and
using language models. In the strongly supervised settings, the LSTM achieved
very high overall accuracy (less than 1% errors), but errors increased when
sequential and structural information conflicted. The frequency of such errors
rose sharply in the language-modeling setting. We conclude that LSTMs can
capture a non-trivial amount of grammatical structure given targeted
supervision, but stronger architectures may be required to further reduce
errors; furthermore, the language modeling signal is insufficient for capturing
syntax-sensitive dependencies, and should be supplemented with more direct
supervision if such dependencies need to be captured.


title:
Asymptotic Theory of Dependent Bayesian Multiple Testing Procedures
  Under Possible Model Misspecification

abstract:
  We study asymptotic properties of Bayesian multiple testing procedures and
provide sufficient conditions for strong consistency under general dependence
structure. We also consider a novel Bayesian multiple testing procedure and
associated error measures that coherently accounts for the dependence structure
present in the model. We advocate posterior versions of FDR and FNR as
appropriate error rates and show that their asymptotic convergence rates are
directly associated with the Kullback-Leibler divergence from the true model.
Our results hold even when the class of postulated models is misspecified. We
illustrate our results in a variable selection problem with autoregressive
response variables, and compare the new Bayesian procedure with some existing
methods through extensive simulation studies in the variable selection problem.
Superior performance of the new procedure compared to the others vindicate that
proper exploitation of the dependence structure by multiple testing methods is
indeed important. Moreover, we obtain encouraging results in a real, maize data
context, where we select influential marker variables.


title: Partial autocorrelation parameterization for subset autoregression

abstract:
  A new version of the partial autocorrelation plot and a new family of subset
autoregressive models are introduced. A comprehensive approach to model
identification, estimation and diagnostic checking is developed for these
models. These models are better suited to efficient model building of
high-order autoregressions with long time series. Several illustrative examples
are given.


title:
TYC 8241 2652 1 and the case of the disappearing disk: no smoking gun
  yet

abstract:
  TYC 8241 2652 1 is a young star that showed a strong mid-infrared (mid-IR,
8-25 mu) excess in all observations before 2008 consistent with a dusty disk.
Between 2008 and 2010 the mid-IR luminosity of this system dropped dramatically
by at least a factor of 30 suggesting a loss of dust mass of an order of
magnitude or more. We aim to constrain possible models including removal of
disk material by stellar activity processes, the presence of a binary
companion, or other explanations suggested in the literature. We present new
X-ray observations, optical spectroscopy, near-IR interferometry, and mid-IR
photometry of this system to constrain its parameters and further explore the
cause of the dust mass loss. In X-rays TYC 8241 2652 1 has all properties
expected from a young star: Its luminosity is in the saturation regime and the
abundance pattern shows enhancement of O/Fe. The photospheric Ha line is filled
with a weak emission feature, indicating chromospheric activity consistent with
the observed level of coronal emission. Interferometry does not detect a
companion and sets upper limits on the companion mass of 0.2, 0.35, 0.1 and
0.05 M_sun at projected physical separations of 0.1-4 AU,4-5 AU, 5-10 AU, and
10-30 AU, respectively (assuming a distance of 120.9 pc). Our mid-IR
measurements, the first of the system since 2012, are consistent with the
depleted dust level seen after 2009. The new data confirms that stellar
activity is unlikely to destroy the dust in the disk and shows that scenarios
where either TYC 8241 2652 1 heats the disk of a binary companion or a
potential companion heats the disk of TYC 8241 2652 1 are unlikely.


title: Computing The Analytic Connectivity of A Uniform Hypergraph

abstract:
  The analytic connectivity, proposed as a substitute of the algebraic
connectivity in the setting of hypergraphs, is an important quantity in
spectral hypergraph theory. The definition of the analytic connectivity for a
uniform hypergraph involves a series of optimization problems (POPs) associated
with the Laplacian tensor of the hypergraph with nonnegativity constraints and
a sphere constraint, which poses difficulties in computation. To reduce the
involved computation, properties on the algebraic connectivity are further
exploited, and several important structured uniform hypergraphs are shown to
attain their analytic connectivities at vertices of the minimum degrees, hence
admit a relatively less computation by solving a small number of POPs. To
efficiently solve each involved POP, we propose a feasible trust region
algorithm ({\tt FTR}) by exploiting their special structures. The global
convergence of {\tt FTR} to the second-order necessary conditions points is
established, and numerical results for both small and large size examples with
comparison to other existing algorithms for POPs are reported to demonstrate
the efficiency of our proposed algorithm.


title:
Efficient Monte Carlo Estimation of the Expected Value of Sample
  Information using Moment Matching

abstract:
  The Expected Value of Sample Information (EVSI) is used to calculate the
economic value of a new research strategy. While this value would be important
to both researchers and funders, there are very few practical applications of
the EVSI. In the main, this is due to computational difficulties associated
with calculating the EVSI in practical health economic models using nested
simulations. We present an approximation method for the EVSI that is based on
estimating the distribution of the posterior mean of the incremental net
benefit across all the possible future samples, known as the distribution of
the preposterior mean. Specifically, we suggest that this distribution is
estimated using moment matching coupled with simulations that are available for
probabilistic sensitivity analysis, which is typically mandatory in health
economic evaluation. We demonstrate that this method is successful using an
example that has previously been applied to other EVSI approximation methods.
We then conclude by discussing how our method fits in with other recent
additions to the literature that detail approximation methods for the EVSI.


title: MocServer: What & Where in a few milliseconds

abstract:
  The MocServer is an astronomical service dedicated to the manipulation of
data set coverages. This server sets together about 15 000 spatial footprints
associated to catalogs, data bases and pixel surveys. Thanks to the Multi-Order
Coverage map coding method (MOC1.0 IVOA standard), the MocServer is able to
provide in a few milliseconds the list of data set identifiers intersecting any
polygon on the sky. The MOC server has been deployed in June 2015 by the Centre
de Donnees astronomiques de Strasbourg. It is operational and already in use by
Aladin Desktop and Aladin Lite prototype versions.


title: On Infinite Product Identities Generating Solutions for Series

abstract:
  In this paper we present a new identity and some of its variants which can be
used for finding solutions while solving fractional infinite and finite series.
We introduce another simple identity which is capable of generating solutions
for some finite series. We demonstrate a method for generation of variants of
the identities based on the findings. The identities are useful for solving
various infinite products.


title: Denoising based Vector Approximate Message Passing

abstract:
  The denoising-based approximate message passing (D-AMP) methodology, recently
proposed by Metzler, Maleki, and Baraniuk, allows one to plug in sophisticated
denoisers like BM3D into the AMP algorithm to achieve state-of-the-art
compressive image recovery. But AMP diverges with small deviations from the
i.i.d.-Gaussian assumption on the measurement matrix. Recently, the vector AMP
(VAMP) algorithm has been proposed to fix this problem. In this work, we show
that the benefits of VAMP extend to D-VAMP.


title: A Formal Approach to Cyber-Physical Attacks

abstract:
  We apply formal methods to lay and streamline theoretical foundations to
reason about Cyber-Physical Systems (CPSs) and cyber-physical attacks. We focus
on %a formal treatment of both integrity and DoS attacks to sensors and
actuators of CPSs, and on the timing aspects of these attacks. Our
contributions are threefold: (1) we define a hybrid process calculus to model
both CPSs and cyber-physical attacks; (2) we define a threat model of
cyber-physical attacks and provide the means to assess attack
tolerance/vulnerability with respect to a given attack; (3) we formalise how to
estimate the impact of a successful attack on a CPS and investigate possible
quantifications of the success chances of an attack. We illustrate definitions
and results by means of a non-trivial engineering application.


title:
Tackling the sign problem with a moment expansion and application to
  Heavy dense QCD

abstract:
  Heavy-Dense QCD (HDQCD) is a popular theory to investigate the sign problem
in quantum field theory. Besides its physical applications, HDQCD is relatively
easy to implement numerically: the fermionic degrees of freedom are integrated
out, and the fermion determinant factorises into local ones. The theory has a
sign problem, the severeness of which depends on the value of the chemical
potential, which makes this theory ideal to test the reach of new algorithms.
We use the LLR approach to obtain the probability distribution of the phase of
the fermion determinant. Our goal is the calculation of the phase factor
expectation value, which appears as Fourier transform of this probability
distribution. We here propose a new and systematic moment expansion for this
phase factor. We compare the answer from the moment expansion order by order
with the exact answer. We find that this expansion converge quickly and works
very well in the strong sign problem region.


title:
Sparse grid high-order ADI scheme for option pricing in stochastic
  volatility models

abstract:
  We present a sparse grid high-order alternating direction implicit (ADI)
scheme for option pricing in stochastic volatility models. The scheme is
second-order in time and fourth-order in space. Numerical experiments confirm
the computational efficiency gains achieved by the sparse grid combination
technique.


title: Quiver relations and associated symmetric polynomials

abstract:
  The idea is to identify certain path algebra elements with symmetric
functions. We propose such a morphism by solving the quiver relations, which
describe the Plucker-type embedding for quiver grassmannians.


title: Revealing the Anatomy of Vote Trading

abstract:
  Cooperation in the form of vote trading, also known as logrolling, is central
for law-making processes, shaping the development of democratic societies.
Empirical evidence of logrolling is scarce and limited to highly specific
situations because existing methods are not easily applicable to broader
contexts. We have developed a general and scalable methodology for revealing a
network of vote traders, allowing us to measure logrolling on a large scale.
Analysis on more than 9 million votes spanning 40 years in the U.S. Congress
reveals a higher logrolling prevalence in the Senate and an overall decreasing
trend over recent congresses, coincidental with high levels of political
polarization. Our method is applicable in multiple contexts, shedding light on
many aspects of logrolling and opening new doors in the study of hidden
cooperation.


title:
Unique Prediction for High-Energy J/\psi Photoproduction: Color
  Transparency and Saturation

abstract:
  Based on the color-dipole picture, we present a successful parameter-free
prediction for the recent high-energy $J/\psi$ photoproduction data from the
Large Hadron Collider. The experimental data provide empirical evidence for the
transition from color transparency to saturation.


title: Computing the nucleon Dirac radius directly at $Q^2=0$

abstract:
  We describe a lattice approach for directly computing momentum derivatives of
nucleon matrix elements using the Rome method, which we apply to obtain the
isovector magnetic moment and Dirac radius. We present preliminary results
calculated at the physical pion mass using a 2HEX-smeared Wilson-clover action.
For removing the effects of excited-state contamination, the calculations were
done at three source-sink separations and the summation method was used.


title:
Une stratification de Thom-Mather de lensemble asymptotique dune
  application polynomial mapping $F: \mathbb{C}^n \to \mathbb{C}^n$

abstract:
  We prove that the stratification of the asymptotic set associated to a
polynomial mapping $F: \mathbb{C}^n \to \mathbb{C}^n$ defined by "la m\'ethode
des fa\c{c}ons" (arXiv:1407.5329) is a Thom-Mather stratification.
  Nous prouvons que la stratification de lensemble asymptotique dune
application polynomial mapping $F: \mathbb{C}^n \to \mathbb{C}^n$ d\'efinie par
"la m\'ethode des fa\c{c}ons" (arXiv:1407.5329) est une stratification de
Thom-Mather


title: Model Uncertainty Stochastic Mean-Field Control

abstract:
  We consider the problem of optimal control of a mean-field stochastic
differential equation under model uncertainty. The model uncertainty is
represented by ambiguity about the law $\mathcal{L}(X(t))$ of the state $X(t)$
at time $t$. For example, it could be the law $\mathcal{L}_{\mathbb{P}}(X(t))$
of $X(t)$ with respect to the given, underlying probability measure
$\mathbb{P}$. This is the classical case when there is no model uncertainty.
But it could also be the law $\mathcal{L}_{\mathbb{Q}}(X(t))$ with respect to
some other probability measure $\mathbb{Q}$ or, more generally, any random
measure $\mu(t)$ on $\mathbb{R}$ with total mass $1$.
  We represent this model uncertainty control problem as a stochastic
differential game of a mean-field related type stochastic differential equation
(SDE) with two players. The control of one of the players, representing the
uncertainty of the law of the state, is a measure valued stochastic process
$\mu(t)$ and the control of the other player is a classical real-valued
stochastic process $u(t)$. This control with respect to random probability
processes $\mu(t)$ on $\mathbb{R}$ is a new type of stochastic control problems
that has not been studied before. By introducing operator-valued backward
stochastic differential equations, we obtain a sufficient maximum principle for
Nash equilibria for such games in the general nonzero-sum case, and saddle
points for zero-sum games.
  As an application we find an explicit solution of the problem of optimal
consumption under model uncertainty of a cash flow described by a mean-field
related type SDE.


title:
Jetted Tidal Disruptions of Stars as a Flag of Intermediate Mass Black
  Holes at High Redshifts

abstract:
  Tidal disruption events (TDEs) of stars by single or binary supermassive
black holes (SMBHs) brighten galactic nuclei and reveal a population of
otherwise dormant black holes. Adopting event rates from the literature, we aim
to establish general trends in the redshift evolution of the TDE number counts
and their observable signals. We pay particular attention to two types of TDEs
which are expected to be observable out to high redshifts, namely (i) jetted
TDEs whose luminosity is boosted by relativistic beaming, and (ii) TDEs around
binary black holes. We show that the brightest (jetted) TDEs are expected to be
produced by massive black hole binaries if the occupancy of intermediate mass
black holes (IMBHs) in low mass galaxies is high. The same binary population
will also provide gravitational wave sources for eLISA. In addition, we find
that the shape of the X-ray luminosity function of TDEs strongly depends on the
occupancy of IMBHs and could be used to constrain scenarios of SMBH formation.
Finally, we make predictions for the expected number of TDEs observed by future
X-ray telescopes as a function of their sensitivity limits. We find that an
instrument which is 50 times more sensitive than the Burst Alert Telescope
(BAT) on board the Swift satellite is expected to trigger ~10 times more events
than BAT with 50% of the events coming from z>2. Because of their long decay
times, high-redshift TDEs can be mistaken for fixed point sources in deep field
surveys such as the 4Ms survey with the Chandra X-ray Observatory and targeted
observations of the same deep field with year-long intervals could reveal TDEs.
If the occupation fraction of IMBHs is high, 6-20 TDEs are expected in each
deep field observed by a telescope 50 times more sensitive than Chandra.


title:
Necessary and Sufficient Condition for Nonsingular Fisher Information
  Matrix in ARMA Models

abstract:
  It is demonstrated that a necessary and sufficient condition that the Fisher
information matrix of an ARMA model be nonsingular is that the model not be
redundant, that is, the autoregressive and moving-average polynomials do not
share common roots.


title: Light-Meson Spectroscopy at COMPASS

abstract:
  The goal of the COMPASS experiment at CERN is to study the structure and
spectroscopy of hadrons. The two-stage spectrometer has large acceptance and
covers a wide kinematic range for charged as well as neutral particles allowing
to access a wide range of reactions. Light mesons are studied with negative
(mostly $\pi^-$) and positive ($p$, $\pi^+$) hadron beams with a momentum of
$190\,\text{GeV}/c$.
  The light-meson spectrum is measured in different final states produced in
diffractive dissociation reactions with squared four-momentum transfer $t$ to
the target between $0.1$ and $1.0\,(\text{GeV}/c)^2$. The flagship channel is
the $\pi^-\pi^+\pi^-$ final state, for which COMPASS has recorded the currently
world's largest data sample. These data not only allow us to measure the
properties of known resonances with high precision, but also to search for new
states. Among these is a new axial-vector signal, the $a_1(1420)$, with unusual
properties. The findings are confirmed by the analysis of the $\pi^-\pi^0\pi^0$
final state.


title:
Multiscale modeling of femtosecond laser irradiation on copper film with
  electron thermal conductivity from ab initio calculation

abstract:
  By combining ab initio quantum mechanics calculation and Drude model,
electron temperature and lattice temperature dependent electron thermal
conductivity is calculated and implemented into a multiscale model of laser
material interaction, which couples the classical molecular dynamics and
two-temperature model. The results indicated that the electron thermal
conductivity obtained from ab initio calculation leads to faster thermal
diffusion than that using the electron thermal conductivity from empirical
determination, which further induces deeper melting region, larger number of
density waves travelling inside the copper film and more various speeds of
atomic clusters ablated from the irradiated film surface.