title:
15 cm$^{-1}$ to 12000 cm$^{-1}$ spectral coverage without changing
  optics: diamond beam splitter adaptation of an FTIR spectrometer

abstract:
  In order to facilitate IR absorption measurements of mass-selected ions
isolated in cryogenic matrices, we have upgraded an ion beam deposition
apparatus encompassing a Bruker IFS66v/S FTIR spectrometer. A synthetic diamond
beam splitter without compensator plate and UHV diamond viewports were
installed. We have also modified the IR detector chamber to allow measurements
with 5 different detectors. As a result we can now obtain FT absorption spectra
from 12000 cm$^{-1}$ to 15 cm$^{-1}$ with the same sample held under ultrahigh
vacuum conditions, simply by switching between appropriate IR detectors. We
demonstrate performance of the upgraded FTIR spectrometer by presenting
measurements of matrix isolated fullerene ions and an adhesive tape.


title:
Not that long time ago in the nearest galaxy: 3D slice of molecular gas
  revealed by a 110 years old flare of Sgr A*

abstract:
  A powerful outburst of X-ray radiation from the supermassive black hole Sgr
A* at the center of the Milky Way is believed to be responsible for the
illumination of molecular clouds in the central ~100 pc of the Galaxy (Sunyaev
et al., 1993, Koyama et al., 1996). The reflected/reprocessed radiation comes
to us with a delay corresponding to the light propagation time that depends on
the 3D position of molecular clouds with respect to Sgr A*. We suggest a novel
way of determining the age of the outburst and positions of the clouds by
studying characteristic imprints left by the outburst in the spatial and time
variations of the reflected emission. We estimated the age of the outburst that
illuminates the Sgr A molecular complex to be ~110 yr. This estimate implies
that we see the gas located ~10 pc further away from us than Sgr A*. If the Sgr
B2 complex is also illuminated by the same outburst, then it is located ~130 pc
closer than our Galactic Center. The outburst was short (less than a few years)
and the total amount of emitted energy in X-rays is $\displaystyle \sim
10^{48}\rho_3^{-1}$ erg, where $\rho_3$ is the mean hydrogen density of the
cloud complex in units of $10^3 {\rm cm^{-3}}$. Energetically, such fluence can
be provided by a partial tidal disruption event or even by a capture of a
planet. Further progress in more accurate positioning and timing of the
outburst should be possible with future X-ray polarimetric observations and
long-term systematic observations with Chandra and XMM-Newton. A few
hundred-years long X-ray observations would provide a detailed 3D map of the
gas density distribution in the central $\sim 100$ pc region.


title: End-to-End Training Approaches for Discriminative Segmental Models

abstract:
  Recent work on discriminative segmental models has shown that they can
achieve competitive speech recognition performance, using features based on
deep neural frame classifiers. However, segmental models can be more
challenging to train than standard frame-based approaches. While some segmental
models have been successfully trained end to end, there is a lack of
understanding of their training under different settings and with different
losses.
  We investigate a model class based on recent successful approaches,
consisting of a linear model that combines segmental features based on an LSTM
frame classifier. Similarly to hybrid HMM-neural network models, segmental
models of this class can be trained in two stages (frame classifier training
followed by linear segmental model weight training), end to end (joint training
of both frame classifier and linear weights), or with end-to-end fine-tuning
after two-stage training.
  We study segmental models trained end to end with hinge loss, log loss,
latent hinge loss, and marginal log loss. We consider several losses for the
case where training alignments are available as well as where they are not.
  We find that in general, marginal log loss provides the most consistent
strong performance without requiring ground-truth alignments. We also find that
training with dropout is very important in obtaining good performance with
end-to-end training. Finally, the best results are typically obtained by a
combination of two-stage training and fine-tuning.


title: Two Stage Optimization with Recourse and Revocation

abstract:
  Two-stage optimization with recourse model is an important and widely used
model, which has been studied extensively these years. In this article, we will
look at a new variant of it, called the two-stage optimization with recourse
and revocation model. This new model differs from the traditional one in that
one is allowed to revoke some of his earlier decisions and withdraw part of the
earlier costs, which is not unlikely in many real applications, and is
therefore considered to be more realistic under many situations. We will adopt
several approaches to study this model. In fact, we will develop an LP rounding
scheme for some cover problems and show that they can be solved using this
scheme and an adaptation of the rounding approach for the deterministic
counterpart, provided the polynomial scenario assumption. Stochastic
uncapacitated facility location problem will also be studied to show that the
approximation algorithm that worked for the two-stage with recourse model
worked for this model as well. In addition, we will use other methods to study
the model.


title: Random constraint sampling and duality for convex optimization

abstract:
  We are interested in solving convex optimization problems with large numbers
of constraints. Randomized algorithms, such as random constraint sampling, have
been very successful in giving nearly optimal solutions to such problems. In
this paper, we combine random constraint sampling with the classical
primal-dual algorithm for convex optimization problems with large numbers of
constraints, and we give a convergence rate analysis. We then report numerical
experiments that verify the effectiveness of this algorithm.


title: Revisiting Link Prediction: Evolving Models and Real Data Findings

abstract:
  The explosive growth of Web 2.0, which was characterized by the creation of
online social networks, has reignited the study of factors that could help us
understand the growth and dynamism of these networks. Various generative
network models have been proposed, including the Barabasi-Albert and
Watts-Strogatz models. In this study, we revisit the problem from a perspective
that seeks to compare results obtained from these generative models with those
from real networks. To this end, we consider the dating network Skout Inc. An
analysis is performed on the topological characteristics of the network that
could explain the creation of new network links. Afterwards, the results are
contrasted with those obtained from the Barabasi-Albert and Watts-Strogatz
generative models. We conclude that a key factor that could explain the
creation of links originates in its cluster structure, where link
recommendations are more precise in Watts-Strogatz segmented networks than in
Barabasi-Albert hierarchical networks. This result reinforces the need to
establish more and better network segmentation algorithms that are capable of
clustering large networks precisely and efficiently.


title: Controlled Quantum Operations of a Semiconductor Three-Qubit System

abstract:
  The Coulomb interactions between electrons play important roles in coupling
multiple qubits in various quantum systems. Here we demonstrate controlled
quantum operations of three electron charge qubits based on three capacitively
coupled semiconductor double quantum dots. The strong interactions between one
double dot and other two double dots enable us to control the coherent
rotations of one target qubit by the states of two control qubits.


title: Interplay of inhibition and multiplexing : Largest eigenvalue statistics

abstract:
  The largest eigenvalue of a network provides understanding to various
dynamical as well as stability properties of the underlying system. We
investigate an interplay of inhibition and multiplexing on the largest
eigenvalue statistics of networks. Using numerical experiments, we demonstrate
that presence of the inhibitory coupling may lead to a very different behaviour
of the largest eigenvalue statistics of multiplex networks than those of the
isolated networks depending upon network architecture of the individual layer.
We demonstrate that there is a transition from the Weibull to the Gumbel or to
the Frechet distribution as networks are multiplexed. Furthermore, for denser
networks, there is a convergence to the Gumbel distribution as network size
increases indicating higher stability of larger systems.


title: Bernstein- and Markov-type inequalities for rational functions

abstract:
  Asymptotically sharp Bernstein- and Markov-type inequalities are established
for rational functions on $C^2$ smooth Jordan curves and arcs. The results are
formulated in terms of the normal derivatives of certain Green's functions with
poles at the poles of the rational functions in question. As a special case
(when all the poles are at infinity) the corresponding results for polynomials
are recaptured.


title: New results on top-quark mass, including new methods, in ATLAS

abstract:
  Recent results on top-quark mass measurements with the ATLAS detector using
proton-proton collisions at the Large Hadron Collider are presented. These
results correspond to the measurements in the $t\bar{t}$ all-hadronic and
dilepton channels at $\sqrt{s} = 8\ \mathrm{TeV}$ collisions and an integrated
luminosity of $20\ \mathrm{fb}^{-1}$.


title:
Coherent changes of the circulation in the deep North Atlantic from
  moored transport arrays

abstract:
  In situ boundary arrays have been installed in the North Atlantic to measure
the large-scale ocean circulation. Here, we use measurements at the western
edge of the North Atlantic at $16^\circ$N and $26^\circ$N to investigate
low-frequency variations in deep densities and their associated influence on
ocean transports. At both latitudes, deep waters (below 1100 dbar) at the
western boundary are becoming fresher and less dense. The associated change in
geopotential thickness is about $0.15$ $\mbox{m}^2\mbox{s}^{-2}$ between
2004-2009 and 2010-2014, with the shift occurring between 2009-2010 and earlier
at $26^\circ$N than $16^\circ$N. Without a similar density change on the east
of the Atlantic, a mid-depth reduction in water density at the west drives an
increase in the shear between the upper and lower layers of North Atlantic Deep
Water of about 2.6 Sv at $26^\circ$N and 3.9 Sv at $16^\circ$N. While these
transport anomalies result in an intensifying tendency in the meridional
overturning circulation (MOC) estimate at $16^\circ$N, the method of applying a
zero net mass transport constraint at $26^\circ$N results in an opposing
(reducing) tendency of the MOC.


title: Stable giant vortex annuli in microwave-coupled atomic condensates

abstract:
  Stable self-trapped vortex annuli (VAs) with large values of topological
charge S (giant VAs) are not only a subject of fundamental interest, but are
also sought for various applications, such as quantum information processing
and storage. However, in conventional atomic Bose-Einstein condensates (BECs)
VAs with S>1 are unstable. Here, we demonstrate that robust self-trapped
fundamental solitons (with S=0) and bright VAs (with the stability checked up
to S=5), can be created in the free space by means of the local-field effect
(the feedback of the BEC on the propagation of electromagnetic waves) in a
condensate of two-level atoms coupled by a microwave (MW) field, as well as in
a gas of MW-coupled fermions with spin 1/2. The fundamental solitons and VAs
remain stable in the presence of an arbitrarily strong repulsive contact
interaction (in that case, the solitons are constructed analytically by means
of the Thomas-Fermi approximation). Under the action of the moderate attractive
contact interaction which, by itself, would lead to collapse, the fundamental
solitons and VAs exist and are stable, respectively; it is interesting that
higher-order VAs are more robust than their lower-order couterparts, on the
contrary to what is known in other systems that may support stable self-trapped
vortices. Conditions for the experimental realizations of the VAs are
discussed.


title: Short-Term Variations in the Equatorial Rotation Rate of Sunspot Groups

abstract:
  We have detected several periodicities in the solar equatorial rotation rate
of sunspot groups in the Greenwich Photoheliographic Results (GPR) during the
period 1931-1976, the Solar Optical Observing Network (SOON) during the period
1977-2014, and the Debrecen Photoheliographic Data (DPD) during the period
1974-2014. Our results suggest a ~250-day period in the equatorial rotation
rate determined from both the Mt. Wilson Doppler-velocity data and the
sunspot-group data during 1986-2007. However, a wavelet analysis reveals that
this periodicity appears mostly around 1991 in the velocity data, while it is
present in most of the solar cycles covered by the sunspot-group data, mainly
near the minimum epochs of the solar cycles. We also found the signature of a
period of ~1.4 years period in the velocity data during 1990-1995, and in the
equatorial rotation rate of sunspot groups mostly around the year 1956. The
equatorial rotation rate of sunspot groups reveals a strong ~1.6-year
periodicity around 1933 and 1955 and a weaker one around 1976, and a strong
~1.8-year periodicity around 1943. Our analysis also suggests periodicities of
~5 years, ~7 years, and ~17 years as well as some other short-term
periodicities. However, short-term periodicities are mostly present at the time
of solar minima. Hence, short-term periodicities cannot be confirmed because of
the larger uncertainty in the data.


title: Scaling Limits of Solutions of SPDE Driven by L\'evy White Noises

abstract:
  Consider a random process s solution of the stochastic partial differential
equation Ls = w with L a homogeneous operator and w a multidimensional L\'evy
white noise. In this paper, we study the asymptotic effect of zooming in or
zooming out of the process s. More precisely, we give sufficient conditions on
L and w so that the rescaled versions of s converges in law to a self-similar
process of order H at coarse scales and at fine scales. The parameter H depends
on the homogeneity order of the operator L and the Blumenthal-Getoor indices
associated to the L\'evy white noise w. Finally, we apply our general results
to several notorious classes of random processes and random fields.


title:
A New Simulation Approach to Performance Evaluation of Binary Linear
  Codes in the Extremely Low Error Rate Region

abstract:
  In this paper, the sphere bound (SB) is revisited within a general bounding
framework based on nested Gallager regions. The equivalence is revealed between
the SB proposed by Herzberg and Poltyrev and the SB proposed by Kasami et al.,
whereas the latter was rarely cited in the literatures. Interestingly and
importantly, the derivation of the SB based on nested Gallager regions suggests
us a new simulation approach to performance evaluation of binary linear codes
over additive white Gaussian noise (AWGN) channels. In order for the
performance evaluation, the proposed approach decouples the geometrical
structure of the code from the noise statistics. The former specifies the
conditional error probabilities, which are independent of signal-to-noise
ratios (SNRs) and can be simulated and estimated efficiently, while the latter
determines the probabilities of those conditions, which involve SNRs and can be
calculated numerically. Numerical results show that the proposed simulation
approach matches well with the traditional simulation approach in the high
error rate region but is able to evaluate efficiently the performance in the
extremely low error rate region.


title:
Prediction of Geomagnetic Storm Strength from Inner Heliospheric In Situ
  Observations

abstract:
  Prediction of the effects of coronal mass ejections (CMEs) on Earth strongly
depends on knowledge of the interplanetary magnetic field southward component,
Bz. Predicting the strength and duration of Bz inside a CME with sufficient
accuracy is currently impossible, which forms the so-called Bz problem. Here,
we provide a proof-of-concept of a new method for predicting the CME arrival
time, speed, Bz and the resulting Dst index at Earth based only on magnetic
field data, measured in situ in the inner heliosphere (< 1AU). On 2012 June
12-16, three approximately Earthward-directed and interacting CMEs were
observed the by the STEREO imagers, and by Venus Express (VEX) in situ at 0.72
AU, 6 degree away from the Sun Earth line. The CME kinematics are calculated
using the drag-based and WSA-Enlil models, constrained by the arrival time at
VEX, resulting in the CME arrival time and speed at Earth. The CME magnetic
field strength is scaled with a power law from VEX to Wind. Our investigation
shows promising results for the Dst forecast (predicted: -96 and -114 nT (from
2 Dst models), observed: -71 nT), for the arrival speed (predicted: 531 +- 23
km s-1, observed: 488 +- 30 km s-1) and timing (6 +- 1 hours after actual
arrival time). The prediction lead time is 21 hours. The method may be applied
to vector magnetic field data from a spacecraft at an artificial Lagrange point
between the Sun and Earth, or to data taken by any spacecraft temporarily
crossing the Sun--Earth line.


title:
On Lie algebras of generators of infinitesimal symmetries of
  almost-cosymplectic-contact structures

abstract:
  We study Lie algebras of generators of infinitesimal symmetries of
almost-cosymplectic-contact structures of odd dimensional manifolds. The
almost-cosymplectic-contact structure admits on the sheaf of pairs of 1-forms
and functions the structure of a Lie algebra. We describe Lie subalgebras in
this Lie algebra given by pairs generating infinitesimal symmetries of basic
tensor fields given by the almost-cosymplectic-contact structure.


title: A Hybrid Hoare Logic for Gene Network Models

abstract:
  The main difficulty when modelling gene networks is the identification of the
parameters that govern their dynamics. It is particularly difficult for models
in which time is continuous: parameters have real values which cannot be
enumerated. The widespread idea is to infer new constraints that reduce the
range of possible values. Here we present a new work based on a particular
class of Hybrid automata (inspired by Thomas discrete models) where discrete
parameters are replaced by signed celerities. We propose a new approach
involving Hoare logic and weakest precondition calculus (a la Dijkstra) that
generates constraints on the parameter values. Indeed, once proper
specifications are extracted from biological traces with duration information
(found in the literature or biological experiments), they play a role similar
to imperative programs in the classical Hoare logic. We illustrate our hybrid
Hoare logic on a small model controlling the lacI repressor of the lactose
operon.


title: Noncommutative Spaces and Poincar\'e Symmetry

abstract:
  We present a framework which unifies a large class of non-commutative
spacetimes that can be described in terms of a deformed Heisenberg algebra. The
commutation relations between spacetime coordinates are up to linear order in
the coordinates, with structure constants depending on the momenta plus terms
depending only on the momenta. The possible implementations of the action of
Lorentz transformations on these deformed phase spaces are considered, together
with the consistency requirements they introduce. It is found that Lorentz
transformations in general act nontrivially on tensor products of momenta. In
particular the Lorentz group element which acts on the left and on the right of
a composition of two momenta is different, and depends on the momenta involved
in the process. We conclude with two representative examples, which illustrate
the mentioned effect.


title:
Many-point classical conformal blocks and geodesic networks on the
  hyperbolic plane

abstract:
  We study the semiclassical holographic correspondence between 2d CFT n-point
conformal blocks and massive particle configurations in the asymptotically AdS3
space. On the boundary we use the heavy-light approximation in which case two
of primary operators are the background for the other (n-2) operators
considered as fluctuations. In the bulk the particle dynamics can be reduced to
the hyperbolic time slice. Although lacking exact solutions we nevertheless
show that for any n the classical n-point conformal block is equal to the
length of the dual geodesic network connecting n-3 cubic vertices of worldline
segments. To this end, both the bulk and boundary systems are reformulated as
potential vector fields. Gradients of the conformal block and geodesic length
are given respectively by accessory parameters of the monodromy problem and
particle momenta of the on-shell worldline action represented as a function of
insertion points. We show that the accessory parameters and particle momenta
are constrained by two different algebraic equation systems which nevertheless
have the same roots thereby guaranteeing the correspondence.


title:
Optimal Mechanisms for Selling Two Items to a Single Buyer Having
  Uniformly Distributed Valuations

abstract:
  We consider the design of a revenue-optimal mechanism when two items are
available to be sold to a single buyer whose valuation is uniformly distributed
over an arbitrary rectangle $[c_1,c_1+b_1]\times[c_2,c_2+b_2]$ in the positive
quadrant. We provide an explicit, complete solution for arbitrary nonnegative
values of $(c_1,c_2,b_1,b_2)$. We identify eight simple structures, each with
at most $4$ (possibly stochastic) menu items, and prove that the optimal
mechanism has one of these eight structures. We also characterize the optimal
mechanism as a function of $(c_1,c_2,b_1,b_2)$. The structures indicate that
the optimal mechanism involves (a) an interplay of individual sale and a bundle
sale when $c_1$ and $c_2$ are low, (b) a bundle sale when $c_1$ and $c_2$ are
high, and (c) an individual sale when one of them is high and the other is low.
To the best of our knowledge, our results are the first to show the existence
of optimal mechanisms with no exclusion region. We further conjecture, based on
promising preliminary results, that our methodology can be extended to a wider
class of distributions.


title: Study on the ${\Upsilon}(1S)$ ${\to}$ $B_{c}M$ weak decays

abstract:
  Motivated by the prospects of the potential ${\Upsilon}(1S)$ particle at
high-luminosity heavy-flavor experiments, we studied the ${\Upsilon}(1S)$
${\to}$ $B_{c}M$ weak decays, where $M$ $=$ ${\pi}$, ${\rho}$, $K^{(\ast)}$.
The nonfactorizable contributions to hadronic matrix elements are taken into
consideration with the QCDF approach. It is found that the CKM-favored
${\Upsilon}(1S)$ ${\to}$ $B_{c}{\rho}$ decay has branching ratio of ${\cal
O}(10^{-10})$, which might be measured promisingly by the future experiments.


title: Strong distortion in transformation groups

abstract:
  We discuss boundedness and distortion in transformation groups. We show that
the groups $\mathrm{Diff}^r_0(\mathbb{R}^n)$ and
$\mathrm{Diff}^r(\mathbb{R}^n)$ have the strong distortion property, whenever
$0 \leq r \leq \infty, r \neq n+1$. This implies in particular that every
abstract length function on these groups is bounded. With related techniques we
show that, for $M$ a closed manifold or homeomorphic to the interior of a
compact manifold with boundary, the groups $\mathrm{Diff}_0^r(M)$ satisfy a
relative Higman embedding type property, introduced by Schreier. This answers a
problem asked by Schreier in the famous Scottish Book.


title:
Forensic Analysis of the ChatSecure Instant Messaging Application on
  Android Smartphones

abstract:
  We present the forensic analysis of the artifacts generated on Android
smartphones by ChatSecure, a secure Instant Messaging application that provides
strong encryption for transmitted and locally-stored data to ensure the privacy
of its users.
  We show that ChatSecure stores local copies of both exchanged messages and
files into two distinct, AES-256 encrypted databases, and we devise a technique
able to decrypt them when the secret passphrase, chosen by the user as the
initial step of the encryption process, is known.
  Furthermore, we show how this passphrase can be identified and extracted from
the volatile memory of the device, where it persists for the entire execution
of ChatSecure after having been entered by the user, thus allowing one to carry
out decryption even if the passphrase is not revealed by the user.
  Finally, we discuss how to analyze and correlate the data stored in the
databases used by ChatSecure to identify the IM accounts used by the user and
his/her buddies to communicate, as well as to reconstruct the chronology and
contents of the messages and files that have been exchanged among them.
  For our study we devise and use an experimental methodology, based on the use
of emulated devices, that provides a very high degree of reproducibility of the
results, and we validate the results it yields against those obtained from real
smartphones.


title: Topological K-theory of affine Hecke algebras

abstract:
  Let H(R,q) be an affine Hecke algebra with a positive parameter function q.
We are interested in the topological K-theory of H(R,q), that is, the K-theory
of its C*-completion C*_r (R,q). We will prove that $K_* (C*_r (R,q))$ does not
depend on the parameter q. For this we use representation theoretic methods, in
particular elliptic representations of Weyl groups and Hecke algebras.
  Thus, for the computation of these K-groups it suffices to work out the case
q=1. These algebras are considerably simpler than for q not 1, just crossed
products of commutative algebras with finite Weyl groups. We explicitly
determine $K_* (C*_r (R,q))$ for all classical root data R, and for some others
as well. This will be useful to analyse the K-theory of the reduced C*-algebra
of any classical p-adic group.
  For the computations in the case q=1 we study the more general situation of a
finite group \Gamma acting on a smooth manifold M. We develop a method to
calculate the K-theory of the crossed product $C(M) \rtimes \Gamma$. In
contrast to the equivariant Chern character of Baum and Connes, our method can
also detect torsion elements in these K-groups.


title: Study on ${\Upsilon}(nS)$ ${\to}$ $B_{c}M$ decays

abstract:
  With anticipation of abundant Upsilons data sample at high-luminosity
heavy-flavor experiments in the future, we studied nonleptonic two-body weak
decays of ${\Upsilon}(nS)$ below the open-bottom threshold with $n$ $=$ $1$,
$2$ and $3$. It is found that branching ratios for ${\Upsilon}(1S,2S,3S)$
${\to}$ $B_{c}{\rho}$ decays are relatively large among upsilons decay into
$B_{c}M$ final states ($M$ $=$ ${\pi}$ ${\rho}$, $K$ and $K^{\ast}$) and can
reach up to $10^{-10}$, which is promisingly detected by experiments at the
running LHC and forthcoming SuperKEKB.


title: Direct observation of how the heavy fermion state develops in CeCoIn5

abstract:
  Heavy fermion materials gain high electronic masses and expand Fermi surfaces
when the high-temperature localized f electrons become itinerant and hybridize
with the conduction band at low temperatures. However, despite the common
application of this model, direct microscopic verification remains lacking.
Here we report high-resolution angle-resolved photoemission spectroscopy
measurements on CeCoIn5, a prototypical heavy fermion compound, and reveal the
long-sought band hybridization and Fermi surface expansion. Unexpectedly, the
localized-to-itinerant transition occurs at surprisingly high temperatures, yet
f electrons are still largely localized at the lowest temperature. Moreover,
crystal field excitations likely play an important role in the anomalous
temperature dependence. Our results paint an comprehensive unanticipated
experimental picture of the heavy fermion formation in a periodic multi-level
Anderson/Kondo lattice, and set the stage for understanding the emergent
properties in related materials.


title: Contact angles of a drop pinned on an incline

abstract:
  For a drop on an incline with small tilt angle or small Bond number, when the
contact line is a circle, we show that the retentive force factor is exactly
pi/2 at first order in the tilt angle or the Bond number. The retentive force
factor is the ratio between the weight component along the slope and a
capillary force defined as surface tension times radius of contact line times
difference of cosines of contact angles at the back and at the front of the
drop. The drop profile is computed exactly in the same approximation. These
results are compared with Surface Evolver results, showing a surprisingly large
range of applicability of first order approximations.


title: Quasilinear generalized parabolic Anderson model equation

abstract:
  We present in this note a local in time well-posedness result for the
singular $2$-dimensional quasilinear generalized parabolic Anderson model
equation $$ \partial_t u - a(u)\Delta u = g(u)\xi $$ The key idea of our
approach is a simple transformation of the equation which allows to treat the
problem as a semilinear problem. The analysis is done within the elementary
setting of paracontrolled calculus.


title: Two-pole structure of the $D^\ast_0(2400)$

abstract:
  The so far only known charmed non-strange scalar meson is dubbed as
$D_0^*(2400)$ in the Review of Particle Physics. We show, within the framework
of unitarized chiral perturbation theory, that there are in fact two $(I=1/2,
J^P=0^+)$ poles in the region of the $D_0^*(2400)$ in the coupled-channel
$D\pi$, $D\eta$ and $D_s\bar K$ scattering amplitudes. With all the parameters
previously fixed, we predict the energy levels for the coupled-channel system
in a finite volume, and find that they agree remarkably well with recent
lattice QCD calculations. This successful description of the lattice data is
regarded as a strong evidence for the two-pole structure of the $D_0^*(2400)$.
With the physical quark masses, the poles are located at
$\left(2105^{+6}_{-8}-i\,102^{+10}_{-12}\right)$~MeV and
$\left(2451^{+36}_{-26}-i\,134^{+7}_{-8}\right)$~MeV, with the largest
couplings to the $D\pi$ and $D_s\bar K$ channels, respectively. Since the
higher pole is close to the $D_s\bar K$ threshold, we expect it to show up as a
threshold enhancement in the $D_s\bar K$ invariant mass distribution. This
could be checked by high-statistic data in future experiments. We also show
that the lower pole belongs to the same SU(3) multiplet as the $D_{s0}^*(2317)$
state. Predictions for partners in the bottom sector are also given.


title: Conjugacy classes of centralizers in unitary groups

abstract:
  Let $G$ be a group. Two elements $x,y \in G$ are said to be in the same
$z$-class if their centralizers in $G$ are conjugate within $G$. Consider
$\mathbb F$ a perfect field of characteristic $\neq 2$, which has a non-trivial
Galois automorphism of order $2$. Further, suppose that the fixed field
$\mathbb F_0$ has the property that it has only finitely many field extensions
of any finite degree. In this paper, we prove that the number of $z$-classes in
the unitary group over such fields is finite. Further, we count the number of
$z$-classes in the finite unitary group $U_n(q)$, and prove that this number is
same as that of $GL_n(q)$ when $q>n$.


title:
Estimate of the Fermi Large Area Telescope sensitivity to gamma-ray
  polarization

abstract:
  Although not designed primarily as a polarimeter, the \textit{Fermi}-Large
Area Telescope (LAT) has the potential to detect high degrees of linear
polarization from some of the brightest gamma-ray sources. To achieve the
needed accuracy in the reconstruction of the event geometry, low-energy
($\leq200$ MeV) events converting in the silicon detector layers of the LAT
tracker have to be used. We present preliminary results of the ongoing effort
within the LAT collaboration to measure gamma-ray polarization. We discuss the
statistical and systematic uncertainties affecting such a measurement. We show
that a $5\sigma$ minimum detectable polarization (MDP) of $\approx30-50\%$
could be within reach for the brightest gamma-ray sources as the Vela and Crab
pulsars and the blazar 3C 454.3, after 10 years of observation. To estimate the
systematic uncertainties, we stack bright AGN, and use this stack as a test
source. LAT sensitivity to polarization is estimated comparing the data to a
simulation of the expected unpolarized emission of the stack. We measure a
5$\sigma$ sensitivity limit corresponding to a polarization degree of
$\approx37\%$. This is in agreement with a purely statistical estimate,
suggesting that the systematic errors are likely to be small compared to the
statistical ones.


title:
Unconventional superconductivity from magnetism in transition metal
  dichalcogenide

abstract:
  We investigate proximity-induced superconductivity in monolayers of
transition metal dichalcogenides (TMDs) in the presence of an externally
generated exchange field. A variety of superconducting order parameters is
found to emerge from the interplay of magnetism and superconductivity, covering
the entire spectrum of possibilities to be symmetric or antisymmetric with
respect to the valley and spin degrees of freedom, as well as even or odd in
frequency. More specifically, when a conventional \emph{s}-wave superconductor
with singlet Copper pairs is tunnel-coupled to the TMD layer, both spin-singlet
and triplet pairings between electrons from the same and opposite valleys arise
due to the combined effects of intrinsic spin-orbit coupling and a
magnetic-substrate-induced exchange field. As a key finding, we reveal the
existence of an exotic even-frequency triplet pairing between equal-spin
electrons from different valleys, which arises whenever the spin orientations
in the two valleys are noncollinear. All types of superconducting order turn
out to be highly tunable via straightforward manipulation of the external
exchange field.


title:
Minimax Error of Interpolation and Optimal Design of Experiments for
  Variable Fidelity Data

abstract:
  Engineering problems often involve data sources of variable fidelity with
different costs of obtaining an observation. In particular, one can use both a
cheap low fidelity function (e.g. a computational experiment with a CFD code)
and an expensive high fidelity function (e.g. a wind tunnel experiment) to
generate a data sample in order to construct a regression model of a high
fidelity function. The key question in this setting is how the sizes of the
high and low fidelity data samples should be selected in order to stay within a
given computational budget and maximize accuracy of the regression model prior
to committing resources on data acquisition.
  In this paper we obtain minimax interpolation errors for single and variable
fidelity scenarios for a multivariate Gaussian process regression. Evaluation
of the minimax errors allows us to identify cases when the variable fidelity
data provides better interpolation accuracy than the exclusively high fidelity
data for the same computational budget.
  These results allow us to calculate the optimal shares of variable fidelity
data samples under the given computational budget constraint. Real and
synthetic data experiments suggest that using the obtained optimal shares often
outperforms natural heuristics in terms of the regression accuracy.


title:
An FFT approach to the analysis of dynamic properties of gas/liquid
  interfaces

abstract:
  The characterisation of the dynamic properties of viscoelastic monolayers of
surfactants at the gasliquid interface is very important in the analysis and
prediction of foam stability. With most of the relevant dynamic processes being
rapid (thermal fluctuation, film coalescence etc.) it is important to probe
interfacial dynamics at high deformation rates. Today, only few techniques
allow this, one of them being the characterisation of the propagation of
electrocapillary waves on the liquid surface. Traditionally, this technique has
been applied in a continuous mode (i.e. at constant frequency) in order to
ensure reliable accuracy. Here we explore the possibility to analyse the
propagation of an excited pulse in order to access the interfacial properties
in one single Fourier treatment over a wide range of frequencies. The main
advantage of this approach is that the measurement times and the required
liquid volumes can be reduced significantly. This occurs at the cost of
precision in the measurement, due partly to the presence of a pronounced
resonance of the liquid surface. The pulsed approach may therefore be used to
prescan the surface response before a more in-depth scan at constant frequency;
or to follow the changes of the interfacial properties during surfactant
adsorption.


title:
Simple, self-assembling, single-site model amphiphile for water-free
  simulation of lyotropic phases

abstract:
  Computationally, low-resolution coarse-grained models provide the most viable
means for simulating the large length and time scales associated with
mesoscopic phenomena. Moreover, since lyotropic phases in solution may contain
high solvent to amphiphile ratio, implicit solvent models are appropriate for
many purposes. By modifying the well-known Gay-Berne potential with an imposed
uni-directionality and a longer range, we have come to a simple single-site
model amphiphile that can rapidly self-assemble to give diverse lyotropic
phases without the explicit incorporation of solvent particles. The model
represents a tuneable packing parameter that manifests in the spontaneous
curvature of amphiphile aggregates. Apart from large scale simulations (e.g.
the study of self-assembly, amphiphile mixing, domain formation etc.) this
novel, non-specific model may be useful for suggestive pilot projects with
modest computational resources. No such self-assembling, single-site amphiphile
model has been reported previously in the literature to the best of our
knowledge.


title:
Almost Budget Balanced Mechanisms with Scalar Bids For Allocation of a
  Divisible Good

abstract:
  This paper is about allocation of an infinitely divisible good to several
rational and strategic agents. The allocation is done by a social planner who
has limited information because the agents' valuation functions are taken to be
private information known only to the respective agents. We allow only a scalar
signal, called a bid, from each agent to the social planner. Yang and Hajek
[Jour. on Selected Areas in Comm., 2007] as well as Johari and Tsitsiklis
[Jour. of Oper. Res., 2009] proposed a scalar strategy Vickrey-Clarke-Groves
(SSVCG) mechanism with efficient Nash equilibria. We consider a setting where
the social planner desires minimal budget surplus. Example situations include
fair sharing of Internet resources and auctioning of certain public goods where
revenue maximization is not a consideration. Under the SSVCG framework, we
propose a mechanism that is efficient and comes close to budget balance by
returning much of the payments back to the agents in the form of rebates. We
identify a design criterion for {\em almost budget balance}, impose feasibility
and voluntary participation constraints, simplify the constraints, and arrive
at a convex optimization problem to identify the parameters of the rebate
functions. The convex optimization problem has a linear objective function and
a continuum of linear constraints. We propose a solution method that involves a
finite number of constraints, and identify the number of samples sufficient for
a good approximation.


title: The distance spectra of the derangement graphs

abstract:
  In this paper, we consider the distance spectra of the derangement graphs.
First we give a constructive proof that the connected derangement graphs are of
diameter 2. Then we obtain their distance spectra. In particular, we determine
all their extremal distance eigenvalues.


title: Imprimitive irreducible modules for finite quasisimple groups, II

abstract:
  This work completes the classification of the imprimitive irreducible
modules, over algebraically closed fields of characteristic 0, of the finite
quasisimple groups.


title:
Effect of electromagnetic dipole dark matter on energy transport in the
  solar interior

abstract:
  In recent years, a revised set of solar abundances has led to a discrepancy
in the sound-speed profile between helioseismology and theoretical solar
models. Conventional solutions require additional mechanisms for energy
transport within the Sun. Vincent et al. have recently suggested that dark
matter with a momentum or velocity dependent cross section could provide a
solution. In this work, we consider three models of dark matter with such cross
sections and their effect on the stellar structure. In particular, the three
models incorporate dark matter particles interacting through an electromagnetic
dipole moment: an electric dipole, a magnetic dipole or an anapole. Each model
is implemented in the \texttt{DarkStec} stellar evolution program, which
incorporates the effects of dark matter capture and heat transport within the
solar interior. We show that dark matter with an anapole moment of
$\sim1\mathrm{GeV}^{-2}$ or magnetic dipole moment of $\sim10^{-3}\mu_p$ can
improve the sound-speed profile, small frequency separations and convective
zone radius with respect to the Standard Solar Model. However, the required
dipole moments are strongly excluded by direct detection experiments.


title: Monazite-type SrCrO4 under compression

abstract:
  We report a high-pressure study of monoclinic monazite-type SrCrO4 up to 26
GPa. Therein we combined x-ray diffraction, Raman and optical-absorption
measurements with ab initio calculations, to find a pressure-induced structural
phase transition of SrCrO4 near 8-9 GPa. Evidence of a second phase transition
was observed at 10-13 GPa. The crystal structures of the high-pressure phases
were assigned to the tetragonal scheelite-type and monoclinic AgMnO4-type
structures. Both transitions produce drastic changes in the electronic band gap
and phonon spectrum of SrCrO4. We determined the pressure evolution of the band
gap for the low-pressure and high-pressure phases as well as the frequencies
and pressure dependences of the Raman-active modes. In all three phases most
Raman modes harden under compression; however the presence of low-frequency
modes which gradually soften is also detected. In monazite-type SrCrO4, the
band gap blue-shifts under compression, but the transition to the scheelite
phase causes an abrupt decrease of the band gap in SrCrO4. Calculations showed
good agreement with experiments and were used to better understand the
experimental results. From x-ray diffraction studies and calculations we
determined the pressure dependence of the unit-cell parameters of the different
phases and their ambient-temperature equations of state. The results are
compared with the high-pressure behavior of other monazites, in particular
PbCrO4. A comparison of the high-pressure behavior of the electronic properties
of SrCrO4 (SrWO4) and PbCrO4 (PbWO4) will also be made. Finally, the possible
occurrence of a third structural phase transition is discussed.


title:
Pressure-induced phase transition and bandgap collapse in the
  wide-bandgap semiconductor InTaO4

abstract:
  A pressure-induced phase transition, associated with an increase of the
coordination number of In and Ta, is detected beyond 13 GPa in InTaO4 by
combining synchrotron x-ray diffraction and Raman measurements in a diamond
anvil cell with ab-initio calculations. High-pressure optical-absorption
measurements were also carried out. The high-pressure phase has a monoclinic
structure which shares the same space group with the low-pressure phase (P2/c).
The structure of the high-pressure phase can be considered as a slight
distortion of an orthorhombic structure described by space group Pcna. The
phase transition occurs together with a unit-cell volume collapse and an
electronic bandgap collapse observed by experiments and calculations.
Additionally, a band crossing is found to occur in the low-pressure phase near
7 GPa. The pressure dependence of all the Raman-active modes is reported for
both phases as well as the pressure dependence of unit-cell parameters and the
equations of state. Calculations also provide information on IR-active phonons
and bond distances. These findings provide insights into the effects of
pressure on the physical properties of InTaO4.


title: Model-based Outdoor Performance Capture

abstract:
  We propose a new model-based method to accurately reconstruct human
performances captured outdoors in a multi-camera setup. Starting from a
template of the actor model, we introduce a new unified implicit representation
for both, articulated skeleton tracking and nonrigid surface shape refinement.
Our method fits the template to unsegmented video frames in two stages - first,
the coarse skeletal pose is estimated, and subsequently non-rigid surface shape
and body pose are jointly refined. Particularly for surface shape refinement we
propose a new combination of 3D Gaussians designed to align the projected model
with likely silhouette contours without explicit segmentation or edge
detection. We obtain reconstructions of much higher quality in outdoor settings
than existing methods, and show that we are on par with state-of-the-art
methods on indoor scenes for which they were designed


title: Low complexity Haar null sets without G_{\delta} hulls in Z^\omega

abstract:
  We show that for every $2\le \xi<\omega_1$ there exists a Haar null set in
$\mathbb{Z}^\omega$ that is the difference of two $\mathbf{\Pi}^0_\xi$ sets but
not contained in any $\mathbf{\Pi}^0_\xi$ Haar null set. In particular, there
exists a Haar null set in $\mathbb{Z}^\omega$ that is the difference of two
$G_\delta$ sets but not contained in any $G_\delta$ Haar null set. This
partially answers a question of M. Elekes and Z. Vidny\'anszky. To prove this,
we also prove a theorem which characterizes the Haar null subsets of
$\mathbb{Z}^\omega$.


title: Subwavelength THz imaging of graphene photoconductivity

abstract:
  Using a spatially structured, optical pump pulse with a THz probe pulse, we
are able to determine spatial variations of the ultrafast THz photoconductivity
with sub-wavelength resolution (75 $\mu m \approx \lambda/5$ at 0.8 THz) in a
planar graphene sample. We compare our results to Raman spectroscopy and
correlate the existence of the spatial inhomogeneities between the two
measurements. We find a strong correlation with inhomogeneity in electron
density. This demonstrates the importance of eliminating inhomogeneities in
doping density during CVD growth and fabrication for photoconductive devices.


title:
Follow-the-leader approximations of macroscopic models for vehicular and
  pedestrian flows

abstract:
  We review recent results and present new ones on a deterministic
follow-the-leader particle approximation of first and second order models for
traffic flow and pedestrian movements. We start by constructing the particle
scheme for the first order Lighthill-Whitham-Richards (LWR) model for traffic
flow. The approximation is performed by a set of ODEs following the position of
discretised vehicles seen as moving particles. The convergence of the scheme in
the many particle limit towards the unique entropy solution of the LWR equation
is proven in the case of the Cauchy problem on the real line. We then extend
our approach to the Initial-Boundary Value Problem (IBVP) with time-varying
Dirichlet data on a bounded interval. In this case we prove that our scheme is
convergent strongly in $L^1$ up to a subsequence. We then review extensions of
this approach to the Hughes model for pedestrian movements and to the second
order Aw-Rascle-Zhang (ARZ) model for vehicular traffic. Finally, we complement
our results with numerical simulations. In particular, the simulations
performed on the IBVP and the ARZ model suggest the consistency of the
corresponding schemes, which is easy to prove rigorously in some simple cases.


title: Singlet vs Nonsinglet Perturbative Renormalization of Fermion Bilinears

abstract:
  In this paper we present the perturbative evaluation of the difference
between the renormalization functions of flavor singlet and nonsinglet bilinear
quark operators on the lattice. The computation is performed to two loops and
to lowest order in the lattice spacing, for a class of improved lattice
actions, including Wilson, tree-level (TL) Symanzik and Iwasaki gluons, twisted
mass and SLiNC Wilson fermions, as well as staggered fermions with twice
stout-smeared links. In the staggered formalism, the stout smearing procedure
is also applied to the definition of bilinear operators.


title: Improving Kaufman's exceptional set estimate for packing dimension

abstract:
  Given $0 < s < 1$, I prove that there exists a constant $\epsilon =
\epsilon(s) > 0$ such that the following holds. Let $K \subset \mathbb{R}^{2}$
be a Borel set with $\mathcal{H}^{1}(K) > 0$, and let $E_{s}(K) \subset S^{1}$
be the collection of unit vectors $e$ such that $$\dim_{\mathrm{p}} \pi_{e}(K)
\leq s.$$ Then $\dim_{\mathrm{H}} E_{s}(K) \leq s - \epsilon$.


title: Tropical spectrahedra

abstract:
  We introduce tropical spectrahedra, defined as the images by the
nonarchimedean valuation of spectrahedra over the field of real Puiseux series.
We provide an explicit polyhedral characterization of generic tropical
spectrahedra, involving principal tropical minors of size at most 2. One of the
key ingredients is Denef-Pas quantifier elimination result over valued fields.
We obtain from this that the nonarchimedean valuation maps semialgebraic sets
to semilinear sets that are closed. We also prove that, under a regularity
assumption, the image by the valuation of a basic semialgebraic set is obtained
by tropicalizing the inequalities which define it.


title: Analysis of Finite Element Methods for Vector Laplacians on Surfaces

abstract:
  We develop a finite element method for the vector Laplacian based on the
covariant derivative of tangential vector fields on surfaces embedded in
$\mathbb{R}^3$. Closely related operators arise in models of flow on surfaces
as well as elastic membranes and shells. The method is based on standard
continuous parametric Lagrange elements which describe a $\mathbb{R}^3$ vector
field on the surface and the tangent condition is weakly enforced using a
penalization term. We derive error estimates that take the approximation of
both the geometry of the surface and the solution to the partial differential
equation into account. In particular we note that to achieve optimal order
error estimates, in both energy and $L^2$ norms, the normal approximation used
in the penalization term must be of the same order as the approximation of the
solution. This can be fulfilled either by using an improved normal in the
penalization term, or by increasing the order of the geometry approximation. We
also present numerical results using higher-order finite elements that verify
our theoretical findings.


title:
On Hahn polynomial expansion of a continuous function of bounded
  variation

abstract:
  We consider the well-known method of least squares on an equidistant grid
with $N+1$ nodes on the interval $[-1,1]$. We investigate the following
problem: For which ratio $N/n$ and which functions, do we have pointwise
convergence of the least square operator
${LS}_n^N:\mathcal{C}\left[-1,1\right]\rightarrow\mathcal{P}_n$? To solve this
problem we investigate the relation between the Jacobi polynomials
$P_k^{\alpha,\beta}$ and the Hahn polynomials
$Q_k\left(\cdot;\alpha,\beta,N\right)$. Thereby we describe the least square
operator ${LS}_n^N$ by the expansion of a function by Hahn polynomials. In
particular we present the following result: The series expansion
$\sum_{k=0}^n{\hat{f} Q_k}$ of a function $f$ by Hahn polynomials $Q_k$
converges pointwise, if the series expansion $\sum_{k=0}^n{\hat{f} P_k}$ of the
function $f$ by Jacobi polynomials $P_k$ converges pointwise and if
${n^4}/N\rightarrow 0$ for $n,N\rightarrow\infty$. Furthermore we obtain the
following result: Let
$f\in\left\{g\in\mathcal{C}^1\left[-1,1\right]:g^\prime\in\mathcal{BV}\left[-1,1\right]\right\}$
and let $(N_n)_{n}$ be a sequence of natural numbers with
${n^4}/{N_n}\rightarrow 0$. Then the least square method ${LS}_n^{N_n}[f]$
converges for each $x\in[-1,1]$.


title:
A general algorithm for calculation of recombination losses in
  ionization chambers exposed to ion beams

abstract:
  Dosimetry with ionization chambers in clinical ion beams for radiation
therapy requires correction for recombination effects. However, common
radiation protocols discriminate between initial and general recombination and
provide no universal correction method for the presence of both recombination
types in ion beams of charged particles heavier than protons. Here, we present
the open source code IonTracks, where the combined initial and general
recombination effects in principle can be predicted for any ion beam with
arbitrary particle-energy spectrum and temporal structure. IonTracks uses track
structure theory to distribute the charge carriers in ion tracks. The charge
carrier movements are governed by a pair of coupled differential equations,
based on fundamental physical properties as charge carrier drift, diffusion,
and recombination, which are solved numerically while the initial and general
charge carrier recombination is computed.
  The algorithm is numerically stable and in accordance with experimentally
validated theories for initial recombination in heavy ion tracks and general
recombination in a proton beam.
  IonTracks is validated against the Jaff\'e's and Boag's theory of
recombination in pulsed beams of multiple ion species. IonTracks is able to
calculate the correction factor for initial and general recombination losses in
parallel-plate ionization chambers. Even if only few experimental data on
recombination effects in ionization chambers are available today, the universal
concept of IonTracks is not limited to the ions investigated here. Future
experimental investigations of recombination in pulsed and possibly also
continuous ion beams may be conducted with IonTracks, which ultimately may lead
to a more precise prediction of recombination factors in complex radiation
fields.


title:
Study of Domains in the Ground State of the Two Dimensional Coulomb
  Glass

abstract:
  We have annealed two dimensional lattice model of Coulomb glass using Monte
Carlo simulations to obtain the ground state. We have shown that the energy
required to create a domain of linear size L in d dimensions is proportional to
$L^{d-1}$. Using Imry-Ma arguments given for RFIM, one gets $d_{c}\geq 2$ for
Coulomb glass. The investigations in the transition region shows that the
domain wall of the metastable state in the charge-ordered phase shifts as
disorder is increased to give disordered ground state at higher disorder
strength indicating phase coexistence. This coupled with discontinuity in
magnetization is an indication of first-order type transition from
charge-ordered phase to disordered phase. The structure and nature of Random
field fluctuations of the domain in Coulomb glass are inconsistent with the
assumptions of Imry and Ma as was also reported for RFIM.


title: Non-ergodicity in the Anisotropic Dicke model

abstract:
  We study the ergodic -- non-ergodic transition in a generalized Dicke model
with independent co- and counter rotating light-matter coupling terms. By
studying level statistics, the average ratio of consecutive level spacings, and
the quantum butterfly effect (out-of-time correlation) as a dynamical probe, we
show that the ergodic -- non-ergodic transition in the Dicke model is a
consequence of the proximity to the integrable limit of the model when one of
the couplings is set to zero. This can be interpreted as a hint for the
existence of a quantum analogue of the classical Kolmogorov-Arnold-Moser
theorem. Besides, we show that there is no intrinsic relation between the
ergodic -- non-ergodic transition and the precursors of the normal --
superradiant quantum phase transition.


title:
Comments on "Bayesian Solution Uncertainty Quantification for
  Differential Equations" by Chkrebtii, Campbell, Calderhead & Girolami

abstract:
  We commend the authors for an exciting paper which provides a strong
contribution to the emerging field of probabilistic numerics (PN). Below, we
discuss aspects of prior modelling which need to be considered thoroughly in
future work.


title: Getting Stuck: Using Monosignatures to Test Highly Ionizing Particles

abstract:
  In this paper we argue that monojet and monophoton searches can be a
sensitive test of very highly ionizing particles such as particles with charges
$\gtrsim 150e$ and more generally particles that do not reach the outer parts
of the detector. 8 TeV monojet data from the CMS experiment excludes such
objects with masses in the range $\lesssim 650~{\text{GeV}}$ and charges
$\gtrsim 100e$. This nicely complements searches for highly ionizing objects at
ALICE, ATLAS, CMS and LHCb. Expected improvements in these channels will extend
the sensitivity range to $m\lesssim 750~{\text{GeV}}$. This search strategy can
directly be generalized to other particles that strongly interact with the
detector material, such as e.g. magnetic monopoles.


title:
A Localization Approach for Crowdsourced Air Traffic Communication
  Networks

abstract:
  In this work, we argue that current state-of-the-art methods of aircraft
localization such as multilateration are insufficient, in particular for modern
crowdsourced air traffic networks with random, unplanned deployment geometry.
We propose an alternative, a grid-based localization approach using the
k-Nearest Neighbor algorithm, to deal with the identified shortcomings. Our
proposal does not require any changes to the existing air traffic protocols and
transmitters, and is easily implemented using only low-cost,
commercial-off-the-shelf hardware.
  Using an algebraic multilateration algorithm for comparison, we evaluate our
approach using real-world flight data collected with our collaborative sensor
network OpenSky. We quantify its effectiveness in terms of aircraft location
accuracy, surveillance coverage, and the verification of false position data.
Our results show that the grid-based approach can increase the effective air
traffic surveillance coverage compared to multilateration by a factor of up to
2.5. As it does not suffer from dilution of precision, it is much more robust
in noisy environments and performs better in pre-existing, unplanned receiver
deployments.
  We further find that the mean aircraft location accuracy can be increased by
up to 41% in comparison with multilateration while also being able to pinpoint
the origin of potential spoofing attacks conducted from the ground.


title: Switching in time-optimal problem with control in a ball

abstract:
  In this paper we analyse local regularity of time-optimal controls and
trajectories for an n-dimensional affine control system with a control
parameter, taking values in a k-dimensional closed ball. In the case of k equal
to n-1, we give sufficient conditions in terms of Lie bracket relations for all
optimal controls to be smooth or to have only isolated jump discontinuities.


title:
Fine-grained Recognition in the Noisy Wild: Sensitivity Analysis of
  Convolutional Neural Networks Approaches

abstract:
  In this paper, we study the sensitivity of CNN outputs with respect to image
transformations and noise in the area of fine-grained recognition. In
particular, we answer the following questions (1) how sensitive are CNNs with
respect to image transformations encountered during wild image capture?; (2)
how can we predict CNN sensitivity?; and (3) can we increase the robustness of
CNNs with respect to image degradations? To answer the first question, we
provide an extensive empirical sensitivity analysis of commonly used CNN
architectures (AlexNet, VGG19, GoogleNet) across various types of image
degradations. This allows for predicting CNN performance for new domains
comprised by images of lower quality or captured from a different viewpoint. We
also show how the sensitivity of CNN outputs can be predicted for single
images. Furthermore, we demonstrate that input layer dropout or pre-filtering
during test time only reduces CNN sensitivity for high levels of degradation.
  Experiments for fine-grained recognition tasks reveal that VGG19 is more
robust to severe image degradations than AlexNet and GoogleNet. However, small
intensity noise can lead to dramatic changes in CNN performance even for VGG19.


title: Post-selection free spatial Bell state generation

abstract:
  Spatial states of single photons and spatially entangled photon pairs are
becoming an important resource in quantum communication. This additional degree
of freedom provides an almost unlimited information capacity, making the
development of high-quality sources of spatial entanglement a well-motivated
research direction. We report an experimental method for generation of photon
pairs in a maximally entangled spatial state. In contrast to existing
techniques the method does not require post-selection and allows one to use the
full photon flux from the nonlinear crystal, providing a tool for creating
high-brightness sources of pure spatially entangled photons. Such sources are a
prerequisite for emerging applications in free-space quantum communication.


title: Graphene Plasmons in Triangular Wedges and Grooves

abstract:
  The ability to effectively guide electromagnetic radiation below the
diffraction limit is of the utmost importance in the prospect of all-optical
plasmonic circuitry. Here, we propose an alternative solution to conventional
metal-based plasmonics by exploiting the deep subwavelength confinement and
tunability of graphene plasmons guided along the apex of a graphene-covered
dielectric wedge or groove. In particular, we present a quasi-analytic model to
describe the plasmonic eigenmodes in such a system, including the complete
determination of their spectrum and corresponding induced potential and
electric field distributions. We have found that the dispersion of wedge/groove
graphene plasmons follows the same functional dependence as their flat-graphene
plasmons counterparts, but now scaled by a (purely) geometric factor in which
all the information about the system's geometry is contained. We believe our
results pave the way for the development of novel custom-tailored photonic
devices for subwavelength waveguiding and localization of light based on
recently discovered 2D materials.


title:
Deterministic Distributed (Delta + o(\Delta))-Edge-Coloring, and
  Vertex-Coloring of Graphs with Bounded Diversity

abstract:
  We consider coloring problems in the distributed message-passing setting. The
previously-known deterministic algorithms for edge-coloring employed at least
(2Delta - 1) colors, even though any graph admits an edge-coloring with Delta +
1 colors [V64]. Moreover, the previously-known deterministic algorithms that
employed at most O(Delta) colors required superlogarithmic time
[B15,BE10,BE11,FHK15]. In the current paper we devise deterministic
edge-coloring algorithms that employ only Delta + o(Delta) colors, for a very
wide family of graphs. Specifically, as long as the arboricity is a =
O(Delta^{1 - \epsilon}), for a constant epsilon > 0, our algorithm computes
such a coloring within {polylogarithmic} deterministic time. We also devise
significantly improved deterministic edge-coloring algorithms for {general
graphs} for a very wide range of parameters. Specifically, for any value $\chi$
in the range [4Delta, 2^{o(log Delta)} \cdot Delta], our \chi-edge-coloring
algorithm has smaller running time than the best previously-known
\chi-edge-coloring algorithms. Our algorithms are actually much more general,
since edge-coloring is equivalent to {vertex-coloring of line graphs.} Our
method is applicable to vertex-coloring of the family of graphs with {bounded
diversity} that contains line graphs, line graphs of hypergraphs, and many
other graphs.
  Our results are obtained using a novel technique that connects vertices or
edges in a certain way that reduces clique size. The resulting structures,
which we call {connectors}, can be colored more efficiently than the original
graph. Moreover, the color classes constitute simpler subgraphs that can be
colored even more efficiently using appropriate connectors. Hence, we recurse
until we obtain sufficiently simple structures that are colored directly. We
introduce several types of connectors that are useful for various scenarios.


title: Generalized Zalcman conjecture for some classes of analytic functions

abstract:
  For functions $f(z)= z+ a_2 z^2 + a_3 z^3 + \cdots$ in various subclasses of
normalized analytic functions, we consider the problem of estimating the
generalized Zalcman coefficient functional $\phi(f,n,m;\lambda):=|\lambda a_n
a_m -a_{n+m-1}|$. For all real parameters $\lambda$ and $ \beta<1$, we provide
the sharp upper bound of $\phi(f,n,m;\lambda)$ for functions $f$ satisfying
$\operatorname{Re}f'(z) > \beta$ and hence settles the open problem of
estimating $\phi(f,n,m;\lambda)$ recently proposed by Agrawal and Sahoo [S.
Agrawal and S. k. Sahoo, On coefficient functionals associated with the Zalcman
conjecture, arXiv preprint, 2016]. It is worth mentioning that the sharp
estimations of $\phi(f,n,m;\lambda)$ follow for starlike and convex functions
of order $\alpha$ $(\alpha <1)$ when $\lambda \leq 0$. Moreover, for certain
positive $\lambda$, the sharp estimation of $\phi(f,n,m;\lambda)$ is given when
$f$ is a typically real function or a univalent function with real coefficients
or is in some subclasses of close-to-convex functions.


title: Maximally Divergent Intervals for Anomaly Detection

abstract:
  We present new methods for batch anomaly detection in multivariate time
series. Our methods are based on maximizing the Kullback-Leibler divergence
between the data distribution within and outside an interval of the time
series. An empirical analysis shows the benefits of our algorithms compared to
methods that treat each time step independently from each other without
optimizing with respect to all possible intervals.


title:
Detecting functional decline from normal ageing to dementia: development
  and validation of a short version of the Amsterdam IADL Questionnaire

abstract:
  INTRODUCTION: Detecting functional decline from normal ageing to dementia is
relevant for diagnostic and prognostic purposes. Therefore, the Amsterdam IADL
Questionnaire (A-IADL-Q) was developed: a 70-item proxy-based tool with good
psychometric properties. We aimed to design a short version whilst preserving
its psychometric quality. METHODS: Study partners of subjects (n=1355), ranging
from cognitively normal to dementia subjects, completed the original A-IADL-Q.
We selected the short version items using a stepwise procedure combining
missing data, Item Response Theory and input from respondents and experts. We
investigated internal consistency of the short version as well as concordance
with the original version. To assess its construct validity, we additionally
investigated concordance between the short version and the Mini-Mental State
Examination (MMSE) and Disability Assessment for Dementia (DAD). Lastly, we
investigated differences in IADL scores between diagnostic groups across the
dementia spectrum. RESULTS: We selected 30 items covering the entire spectrum
of IADL functioning. Internal consistency (.98) and concordance with the
original version (.97) were very high. Concordance with the MMSE (.72) and DAD
(.87) scores was high. IADL impairment scores increased across the spectrum
from normal cognition to dementia. DISCUSSION: The A-IADL-Q Short Version
(A-IADL-Q-SV) consists of 30 items. The A-IADL-Q-SV has maintained the
psychometric quality of the original A-IADL-Q. As such, it is a concise measure
of functional decline.


title:
Two Groups of Red Giants with Distinct Chemical Abundances in the Bulge
  Globular Cluster NGC 6553 Through the Eyes of APOGEE

abstract:
  Multiple populations revealed in globular clusters (GCs) are important
windows to the formation and evolution of these stellar systems. The metal-rich
GCs in the Galactic bulge are an indispensable part of this picture, but the
high optical extinction in this region has prevented extensive research. In
this work, we use the high resolution near-infrared (NIR) spectroscopic data
from APOGEE to study the chemical abundances of NGC 6553, which is one of the
most metal-rich bulge GCs. We identify ten red giants as cluster members using
their positions, radial velocities, iron abundances, and NIR photometry. Our
sample stars show a mean radial velocity of $-0.14\pm5.47$ km s$^{-1}$, and a
mean [Fe/H] of $-0.15\pm 0.05$. We clearly separate two populations of stars in
C and N in this GC for the first time. NGC 6553 is the most metal-rich GC where
the multiple stellar population phenomenon is found until now. Substantial
chemical variations are also found in Na, O, and Al. However, the two
populations show similar Si, Ca, and iron-peak element abundances. Therefore,
we infer that the CNO, NeNa, and MgAl cycles have been activated, but the MgAl
cycle is too weak to show its effect on Mg. Type Ia and Type II supernovae do
not seem to have significantly polluted the second generation stars. Comparing
with other GC studies, NGC 6553 shows similar chemical variations as other
relatively metal-rich GCs. We also confront current GC formation theories with
our results, and suggest possible avenues for improvement in the models.


title: Quantum rational preferences and desirability

abstract:
  We develop a theory of quantum rational decision making in the tradition of
Anscombe and Aumann's axiomatisation of preferences on horse lotteries. It is
essentially the Bayesian decision theory generalised to the space of Hermitian
matrices. Among other things, this leads us to give a representation theorem
showing that quantum complete rational preferences are obtained by means of
expected utility considerations.


title:
A priori estimates and positivity for semiclassical ground states for
  systems of critical Schroedinger equations in dimension two

abstract:
  We consider in the whole plane the Hamiltonian coupling of semilinear
Schroedinger equations which have critical growth in the sense of Moser. We
prove that the (nonempty) set S of ground state solutions is compact up to
translations. Moreover, ground states are uniformly bounded and uniformly
decaying at infinity. Then we prove that actually the ground state is positive
and radially symmetric. We apply those results to prove the existence of
semiclassical ground states solutions to the singularly perturbed system when
the external potential stays bounded away from zero. Namely, as the
adimensionalized Planck constant vanishes, we prove the existence of minimal
energy solutions which concentrate around the closest local minima of the
potential with some precise asymptotic rate.


title: The societal impact of big data: A research roadmap for Europe

abstract:
  With its rapid growth and increasing adoption, big data is producing a
substantial impact in society. Its usage is opening both opportunities such as
new business models and economic gains and risks such as privacy violations and
discrimination. Europe is in need of a comprehensive strategy to optimise the
use of data for a societal benefit and increase the innovation and
competitiveness of its productive activities. In this paper, we contribute to
the definition of this strategy with a research roadmap to capture the
economic, social and ethical, legal and political benefits associated with the
use of big data in Europe. The present roadmap considers the positive and
negative externalities associated with big data, maps research and innovation
topics in the areas of data management, processing, analytics, protection,
visualisation, as well as non-technical topics, to the externalities they can
tackle, and provides a time frame to address these topics in order to deliver
social impact, skills development and standardisation. Finally, it also
identifies what sectors will be most benefited by each of the research efforts.
The goal of the roadmap is to guide European research efforts to develop a
socially responsible big data economy, and to allow stakeholders to identify
and meet big data challenges and proceed with a shared understanding of the
societal impact, positive and negative externalities and concrete problems
worth investigating in future programmes.


title:
An evolutionary channel towards the accreting millisecond pulsar SAX
  J1808.4-3658

abstract:
  Recent timing analysis reveals that the orbital period of the first
discovered accreting millisecond pulsar SAX J1808.4-3658 is increasing at a
rate $\dot{P}_{\rm orb}=(3.89\pm0.15)\times 10^{-12}~\rm s\,s^{-1}$, which is
at least one order of magnitude higher than the value arising from the
conservative mass transfer. An ejection of mass loss rate of $10^{-9}~\rm
M_{\odot}{\rm yr}^{-1}$ from the donor star at the inner Lagrangian point
during the quiescence state could interpret the observed orbital period
derivative. However, it is unknown whether this source can offer such a high
mass loss rate. In this work, we attempt to investigate an evolutionary channel
towards SAX J1808.4-3658. Once the accretion disk becomes thermally and
viscously unstable, the spin-down luminosity of the millisecond pulsar and the
X-ray luminosity during outbursts are assumed to evaporate the donor star, and
the resulting winds carry away the specific orbital angular momentum at the
inner Lagrangian point. Our scenario could yield the observed orbital period,
the orbital period derivative, the peak X-ray luminosity during outbursts.
Low-mass X-ray binaries with a $1.0~\rm M_{\odot}$ donor star, and an orbital
period in the range of 0.8 - 1.5 d, may be the progenitor of SAX J1808.4-3658.
Our numerical calculations propose that the current donor star mass is $0.044
~\rm M_{\odot}$, which is in approximately agreement with the minimum mass of
the donor star. In addition, our scenario can also account for the formation of
black widows or the diamond planet like PSR J1719-1438.


title: Automating Induction for Solving Horn Clauses

abstract:
  Verification problems of programs written in various paradigms (such as
imperative, logic, concurrent, functional, and object-oriented ones) can be
reduced to problems of solving Horn clause constraints on predicate variables
that represent unknown inductive invariants. This paper presents a novel Horn
constraint solving method based on inductive theorem proving: the method
reduces Horn constraint solving to validity checking of first-order formulas
with inductively defined predicates, which are then checked by induction on the
derivation of the predicates. To automate inductive proofs, we introduce a
novel proof system tailored to Horn constraint solving and use an SMT solver to
discharge proof obligations arising in the proof search. The main advantage of
the proposed method is that it can verify relational specifications across
programs in various paradigms where multiple function calls need to be analyzed
simultaneously. The class of specifications includes practically important ones
such as functional equivalence, associativity, commutativity, distributivity,
monotonicity, idempotency, and non-interference. Furthermore, our novel
combination of Horn clause constraints with inductive theorem proving enables
us to naturally and automatically axiomatize recursive functions that are
possibly non-terminating, non-deterministic, higher-order, exception-raising,
and over non-inductively defined data types. We have implemented a relational
verification tool for the OCaml functional language based on the proposed
method and obtained promising results in preliminary experiments.


title:
Performance Analysis of Multi-User Massive MIMO Downlink under Channel
  Non-Reciprocity and Imperfect CSI

abstract:
  This paper analyzes the performance of linearly precoded time division duplex
based multi-user massive MIMO downlink system under joint impacts of channel
non-reciprocity (NRC) and imperfect channel state information (CSI). We
consider a generic and realistic NRC model that accounts for transceiver
frequency-response as well as mutual coupling mismatches at both user equipment
(UE) and base station (BS) sides. The analysis covers two most prominent forms
of linear precoding schemes, namely, zero-forcing (ZF) and maximum-ratio
transmission (MRT), and assumes that only the statistical properties of the
beamformed channel are used at the UE side to decode the received signal. Under
the approximation of i.i.d. Gaussian channels, closed-form analytical
expressions are derived for the effective signal to interference and noise
ratios (SINRs) and the corresponding capacity lower bounds. The expressions
show that, in moderate to high SNR, the additional interference caused by
imperfect NRC calibration can degrade the performance of both precoders
significantly. Moreover, ZF is shown to be more sensitive to NRC than MRT.
Numerical evaluations with practical NRC levels indicate that this performance
loss in the spectral efficiency can be as high as 42% for ZF, whereas it is
typically less than 13% for MRT. It is also shown that due to the NRC, the
asymptotic large-antenna performance of both precoders saturate to an identical
finite level. The derived analytical expressions provide useful tools and
valuable technical insight, e.g., into calculating the NRC calibration
requirements in BSs and UEs for any given specific performance targets in terms
of effective SINR or the system capacity bound.


title: Fano Schemes for Generic Sums of Products of Linear Forms

abstract:
  We study the Fano scheme of $k$-planes contained in the hypersurface cut out
by a generic sum of products of linear forms. In particular, we show that under
certain hypotheses, linear subspaces of sufficiently high dimension must be
contained in a coordinate hyperplane. We use our results on these Fano schemes
to obtain a lower bound for the product rank of a linear form. This provides a
new lower bound for the product ranks of the $6\times 6$ Pfaffian and $4\times
4$ permanent, as well as giving a new proof that the product and tensor ranks
of the $3\times 3$ determinant equal five. Based on our results, we formulate
several conjectures.


title:
Giant Positive Magnetoresistance and field-induced metal insulator
  transition in Cr2NiGa

abstract:
  We report here the magneto-transport properties of the newly synthesized
Heusler compound Cr2NiGa which crystallizes in a disordered cubic B2 structure
belonging to Pm-3m space group. The sample is found to be paramagnetic down to
2 K with metallic character. On application of magnetic field, a significantly
large increase in resistivity is observed which corresponds to
magnetoresistance as high as 112% at 150 kOe of field at the lowest
temperature. Most remarkably, the sample shows negative temperature coefficient
of resistivity below about 50 K under the application of field gretare than or
equal to 80 kOe, signifying a field-induced metal to `insulating' transition.
The observed magnetoresistance follows Kohler's rule below 20 K indicating the
validity of the semiclassical model of electronic transport in metal with a
single relaxation time. A multi-band model for electronic transport, originally
proposed for semimetals, is found to be appropriate to describe the
magneto-transport behavior of the sample.


title: Passage times, exit times and Dirichlet problems for open quantum walks

abstract:
  We consider open quantum walks on a graph, and consider the random variables
defined as the passage time and number of visits to a given point of the graph.
We study in particular the probability that the passage time is finite, the
expectation of that passage time, and the expectation of the number of visits,
and discuss the notion of recurrence for open quantum walks. We also study exit
times and exit probabilities from a finite domain, and use them to solve
Dirichlet problems and to determine harmonic measures. We consider in
particular the case of irreducible open quantum walks. The results we obtain
extend those for classical Markov chains.


title:
Variational Koopman models: slow collective variables and molecular
  kinetics from short off-equilibrium simulations

abstract:
  Markov state models (MSMs) and Master equation models are popular approaches
to approximate molecular kinetics, equilibria, metastable states, and reaction
coordinates in terms of a state space discretization usually obtained by
clustering. Recently, a powerful generalization of MSMs has been introduced,
the variational approach (VA) of molecular kinetics and its special case the
time-lagged independent component analysis (TICA), which allow us to
approximate slow collective variables and molecular kinetics by linear
combinations of smooth basis functions or order parameters. While it is known
how to estimate MSMs from trajectories whose starting points are not sampled
from an equilibrium ensemble, this has not yet been the case for TICA and the
VA. Previous estimates from short trajectories, have been strongly biased and
thus not variationally optimal. Here, we employ Koopman operator theory and
ideas from dynamic mode decomposition (DMD) to extend the VA and TICA to
non-equilibrium data. The main insight is that the VA and TICA provide a
coefficient matrix that we call Koopman model, as it approximates the
underlying dynamical (Koopman) operator in conjunction with the basis set used.
This Koopman model can be used to compute a stationary vector to reweight the
data to equilibrium. From such a Koopman-reweighted sample, equilibrium
expectation values and variationally optimal reversible Koopman models can be
constructed even with short simulations. The Koopman model can be used to
propagate densities, and its eigenvalue decomposition provide estimates of
relaxation timescales and slow collective variables for dimension reduction.
Koopman models are generalizations of Markov state models, TICA and the linear
VA and allow molecular kinetics to be described without a cluster
discretization.

categories: stat.ML physics.bio-ph physics.chem-ph q-bio.BM


title:
Asymptotic equivalence of paired Hotelling test and conditional logistic
  regression

abstract:
  Matching, the stratification of observations, is of primary importance for
the analysis of observational studies. We show that the score test of
conditional logistic regression and the paired Student/Hotelling test, two
tests for paired data, are asymptotically equivalent.


title:
Small Bergman-Orlicz and Hardy-Orlicz spaces, and their composition
  operators

abstract:
  We show that the weighted Bergman-Orlicz space $A\_{\alpha}^{\psi}$ coincides
with some weighted Banach space of holomorphic functions if and only if the
Orlicz function $\psi$ satisfies the so-called $\Delta^{2}$--condition. In
addition we prove that this condition characterizes those $A\_{\alpha}^{\psi}$
on which every composition operator is bounded or order bounded into the Orlicz
space $L\_{\alpha}^{\psi}$. This provides us with estimates of the norm and the
essential norm of composition operators on such spaces. We also prove that when
$\psi$ satisfies the $\Delta^{2}$--condition, a composition operator is compact
on $A\_{\alpha}^{\psi}$ if and only if it is order bounded into the so-called
Morse-Transue space $M\_{\alpha}^{\psi}$. Our results stand in the unit ball of
$\mathbb{C}^{N}$.


title:
On the impact of strain on the electronic properties of InAs/GaSb
  quantum well systems

abstract:
  Electron-hole hybridization in InAs/GaSb double quantum well structures leads
to the formation of a mini band gap. We experimentally and theoretically
studied the impact of strain on the transport properties of this material
system. Thinned samples were mounted to piezo electric elements to exert strain
along the [011] and [001] crystal directions. When the Fermi energy is tuned
through the mini gap, a dramatic impact on the resistivity at the charge
neutrality point is found which depends on the amount of applied external
strain. In the electron and hole regimes, strain influences the Landau level
structure. By analyzing the intrinsic strain from the epitaxial growth, the
external strain from the piezo elements and combining our experimental results
with numerical simulations of strained and unstrained quantum wells, we
compellingly illustrate why the InAs/GaSb material system is regularly found to
be semimetallic.


title:
Quasistatic normal-compliance contact problem of visco-elastic bodies
  with Coulomb friction implemented by QP and SGBEM

abstract:
  The quasistatic normal-compliance contact problem of isotropic homogeneous
linear visco-elastic bodies with Coulomb friction at small strains in
Kelvin-Voigt rheology is considered. The discretization is made by a
semi-implicit formula in time and the Symmetric Galerkin Boundary Element
Method (SGBEM) in space, assuming that the ratio of the viscosity and
elasticity moduli is a given relaxation-time coefficient. The obtained
recursive minimization problem, formulated only on the contact boundary, has a
nonsmooth cost function. If the normal compliance responds linearly and the 2D
problems are considered, then the cost function is piecewise-quadratic, which
after a certain transformation gets the quadratic programming (QP) structure.
However, it would lead to second-order cone programming in 3D problems.
Finally, several computational tests are presented and analysed, with
additional discussion on numerical stability and convergence of the involved
approximated Poincar\'e-Steklov operators.


title: Elastic measurements of amorphous silicon films at mK temperatures

abstract:
  The low temperature properties of glass are distinct from those of crystals
due to the presence of poorly understood low-energy excitations. The tunneling
model proposes that these are atoms tunneling between nearby equilibria,
forming tunneling two level systems (TLSs). This model is rather successful,
but it does not explain the remarkably universal value of the mechanical
dissipation $Q^{-1}$ near 1 kelvin. The only known exceptions to this
universality are the $Q^{-1}$ of certain thin films of amorphous silicon,
carbon and germanium. Recently, it was found that $Q^{-1}$ of amorphous silicon
(a-Si) films can be reduced by two orders of magnitude by increasing the
temperature of the substrate during deposition. According to the tunneling
model, the reduction in $Q^{-1}$ at 1 kelvin implies a reduction in
$P_{0}\gamma ^{2}$, where $P_{0}$ is the density of TLSs and $\gamma $ is their
coupling to phonons. In this preliminary report, we demonstrate elastic
measurements of a-Si films down to 20 mK. This will allow us, in future work,
to determine whether $P_{0}$ or $\gamma $ is responsible for the reduction in
$Q^{-1}$ with deposition temperature.


title: Summary of recent experimental results on strangeness production

abstract:
  This article summarises the highlights of the recent experimental findings on
strangeness production presented at the 16th edition of the {\it International
Conference on Strangeness in Quark Matter} in Berkeley. Results obtained by
eight large experimental collaborations (ALICE, ATLAS, CMS, HADES, LHCb, NA-61,
PHENIX, STAR) spanning a large range in centre-of-mass energy and a variety of
collision systems were presented at the conference. The article does not aim at
being a complete review, but rather at connecting the experimental highlights
of the different collaborations and at pointing towards questions which should
be addressed by these experiments in future.


title:
Intrinsic exciton states mixing and non-linear optical properties in
  transition metal dichalcogenide monolayers

abstract:
  Optical properties of transition metal dichalcogenides monolayers are
controlled by the Wannier-Mott excitons forming a series of $1s$, $2s$,
$2p$,... hydrogen-like states. We develop the theory of the excited excitonic
states energy spectrum fine structure. We predict that $p$- and $s$-shell
excitons are mixed due to the specific $D_{3h}$ point symmetry of the
transition metal dichalcogenide monolayers. Hence, both $s$- and $p$-shell
excitons are active in both single- and two-photon processes providing an
efficient mechanism of second harmonic generation. The corresponding
contribution to the nonlinear susceptibility is calculated.


title: Modular Deep Q Networks for Sim-to-real Transfer of Visuo-motor Policies

abstract:
  While deep learning has had significant successes in computer vision thanks
to the abundance of visual data, collecting sufficiently large real-world
datasets for robot learning can be costly. To increase the practicality of
these techniques on real robots, we propose a modular deep reinforcement
learning method capable of transferring models trained in simulation to a
real-world robotic task. We introduce a bottleneck between perception and
control, enabling the networks to be trained independently, but then merged and
fine-tuned in an end-to-end manner to further improve hand-eye coordination. On
a canonical, planar visually-guided robot reaching task a fine-tuned accuracy
of 1.6 pixels is achieved, a significant improvement over naive transfer (17.5
pixels), showing the potential for more complicated and broader applications.
Our method provides a technique for more efficient learning and transfer of
visuo-motor policies for real robotic systems without relying entirely on large
real-world robot datasets.


title: Resurgence Matches Quantization

abstract:
  The quest to find a nonperturbative formulation of topological string theory
has recently seen two unrelated developments. On the one hand, via quantization
of the mirror curve associated to a toric Calabi-Yau background, it has been
possible to give a nonperturbative definition of the topological-string
partition function. On the other hand, using techniques of resurgence and
transseries, it has been possible to extend the string (asymptotic)
perturbative expansion into a transseries involving nonperturbative instanton
sectors. Within the specific example of the local P2 toric Calabi-Yau
threefold, the present work shows how the Borel-Pade-Ecalle resummation of this
resurgent transseries, alongside occurrence of Stokes phenomenon, matches the
string-theoretic partition function obtained via quantization of the mirror
curve. This match is highly non-trivial, given the unrelated nature of both
nonperturbative frameworks, signaling at the existence of a consistent
underlying structure.


title: Les groupes de Mathieu sont-ils aussi sporadiques qu'il y parait ?

abstract:
  A plea to open again the building site of finite simple groups in order to
include finite simple hypergroups.


title: Sylvester-based preconditioning for the waveguide eigenvalue problem

abstract:
  We consider a nonlinear eigenvalue problem (NEP) arising from absorbing
boundary conditions in the study of a partial differential equation (PDE)
describing a waveguide. We propose a new computational approach for this large
scale NEP based on residual inverse iteration (Resinv) with preconditioned
iterative solves. Similar to many preconditioned iterative methods for
discretized PDEs, this approach requires the construction of an accurate and
efficient preconditioner. For the waveguide eigenvalue problem, the associated
linear system can be formulated as a generalized Sylvester equation. The
equation is approximated by a low-rank correction of a Sylvester equation,
which we use as a preconditioner. The action of the preconditioner is
efficiently computed using the matrix equation version of the
Sherman-Morrison-Woodbury (SMW) formula. We show how the preconditioner can be
integrated into Resinv. The results are illustrated by applying the method to
large-scale problems.


title: Tailoring non-collinear magnetism by misfit dislocation lines

abstract:
  The large epitaxial stress induced by the misfit between a triple atomic
layer Fe film and an Ir(111) substrate is relieved by the formation of a dense
dislocation line network. Spin-polarized scanning tunneling microscopy (SP-STM)
investigations show that the strain is locally varying within the Fe film and
that this variation affects the magnetic state of the system. Two types of
dislocation line regions can be distinguished and both exhibit spin spirals
with strain-dependent periods (ranging from 3 nm to 10 nm). Using a simple
micromagnetic model, we attribute the changes of the period of the spin spirals
to variations of the effective exchange coupling in the magnetic film. This
assumption is supported by the observed dependence of the saturation magnetic
field on the spin spiral period. Moreover, magnetic skyrmions appear in an
external magnetic field only in one type of dislocation line area, which we
impute to the different pinning properties of the dislocation lines.


title:
Disorder relevance without Harris Criterion: the case of pinning model
  with $\gamma$-stable environment

abstract:
  We investigate disorder relevance for the pinning of a renewal whose
inter-arrival law has tail exponent $\alpha>0$ when the law of the random
environment is in the domain of attraction of a stable law with parameter
$\gamma \in (1,2)$. We prove that in this case, the effect of disorder is not
decided by the sign of the specific heat exponent as predicted by Harris
criterion but that a new criterion emerges to decide disorder relevance. More
precisely we show that when $\alpha>1-\gamma^{-1}$ there is a shift of the
critical point at every temperature whereas when $\alpha< 1-\gamma^{-1}$, at
high temperature the quenched and annealed critical point coincide, and the
critical exponents are identical.


title: Quantised inertia from relativity and the uncertainty principle

abstract:
  It is shown here that if we assume that what is conserved in nature is not
simply mass-energy, but rather mass-energy plus the energy uncertainty of the
uncertainty principle, and if we also assume that position uncertainty is
reduced by the formation of relativistic horizons, then the resulting increase
of energy uncertainty is close to that needed for a new model for inertial mass
(MiHsC, quantised inertia) which has been shown to predict galaxy rotation
without dark matter and cosmic acceleration without dark energy. The same
principle can also be used to model the inverse square law of gravity, and
predicts the mass of the electron.


title: Robustness of N2H+ as tracer of the CO snowline

abstract:
  [Abridged] Snowlines in protoplanetary disks play an important role in planet
formation and composition. Since the CO snowline is difficult to observe
directly with CO emission, its location has been inferred in several disks from
spatially resolved ALMA observations of DCO+ and N2H+. N2H+ is considered to be
a good tracer of the CO snowline based on astrochemical considerations
predicting an anti-correlation between N2H+ and gas-phase CO. In this work, the
robustness of N2H+ as a tracer of the CO snowline is investigated. A simple
chemical network is used in combination with the radiative transfer code LIME
to model the N2H+ distribution and corresponding emission in the disk around TW
Hya. The assumed CO and N2 abundances, corresponding binding energies, cosmic
ray ionization rate, and degree of large-grain settling are varied to determine
the effects on the N2H+ emission and its relation to the CO snowline. For the
adopted physical structure of the TW Hya disk and molecular binding energies
for pure ices, the balance between freeze-out and thermal desorption predicts a
CO snowline at 19 AU, corresponding to a CO midplane freeze-out temperature of
20 K. A model with a total, i.e. gas plus ice, CO abundance of 3e-6 with
respect to H2 fits the position of the emission peak observed by Qi et al. 2013
for the TW Hya disk. However, the relationship between N2H+ and the CO snowline
is more complicated than generally assumed: for the investigated parameters,
the N2H+ column density peaks at least 5 AU outside the CO snowline. Moreover,
the N2H+ emission can peak much further out, as far as ~50 AU beyond the
snowline. Hence, chemical modeling, as done here, is necessary to derive a CO
snowline location from N2H+ observations.


title: Density Dependence of Nuclear Symmetry Energy

abstract:
  High density behaviour of nuclear symmetry energy is studied on the basis of
a stiffest density dependence of asymmetric contribution to energy per nucleon
in charge neutral $n+p+e+\mu$ matter under beta equilibrium. The density
dependence of nuclear symmetry energy obtained in this way is neither very
stiff nor soft at high densities and is found to be in conformity with recent
observations of neutron stars


title:
Strong convergence analysis of the stochastic exponential Rosenbrock
  scheme for the finite element discretization of semilinear SPDEs driven by
  multiplicative and additive noise

abstract:
  In this paper, we consider the numerical approximation of a general second
order semilinear stochastic partial differential equation (SPDE) driven by
multiplicative and additive noise. Our main interest is on such SPDEs where the
nonlinear part is stronger than the linear part also called stochastic reactive
dominated transport equations. Most numerical techniques, including current
stochastic exponential integrators lose their good stability properties on such
equations. Using finite element for space discretization, we propose a new
scheme appropriated on such equations, called stochastic exponential Rosenbrock
scheme (SERS) based on local linearization at every time step of the
semi-discrete equation obtained after space discretization. We consider noise
that is in a trace class and give a strong convergence proof of the new scheme
toward the exact solution in the root-mean-square $L^2$ norm. Numerical
experiments to sustain theoretical results are provided.


title:
Metadevice for intensity modulation with sub-wavelength spatial
  resolution

abstract:
  Effectively continuous control over propagation of a beam of light requires
light modulation with pixelation that is smaller than the optical wavelength.
Here we propose a spatial intensity modulator with sub-wavelength resolution in
one dimension. The metadevice combines recent advances in reconfigurable
nanomembrane metamaterials and coherent all-optical control of metasurfaces. It
uses nanomechanical actuation of metasurface absorber strips placed near a
mirror in order to control their interaction with light from perfect absorption
to negligible loss, promising a path towards dynamic beam diffraction, light
focusing and holography without unwanted diffraction artefacts.