title:
Spatial localization and pattern formation in discrete optomechanical
  cavities and arrays

abstract:
  We investigate theoretically the generation of nonlinear dissipative
structures in optomechanical (OM) systems containing discrete arrays of
mechanical resonators. We consider both hybrid models in which the optical
system is a continuous multimode field, as it would happen in an OM cavity
containing an array of micro-mirrors, and also fully discrete models in which
each mechanical resonator interacts with a single optical mode, making contact
with Ludwig & Marquardt [Phys. Rev. Lett. 101, 073603 (2013)]. Also, we study
the connections between both types of models and continuous OM models. While
all three types of models merge naturally in the limit of a large number of
densely distributed mechanical resonators, we show that the spatial
localization and the pattern formation found in continuous OM models can be
still observed for a small number of mechanical elements, even in the presence
of finite-size effects, which we discuss. This opens new venues for
experimental approaches to the subject.


title:
Optical decoherence and spectral diffusion in an erbium-doped silica
  glass fiber featuring long-lived spin sublevels

abstract:
  Understanding decoherence in cryogenically-cooled rare-earth-ion doped glass
fibers is of fundamental interest and a prerequisite for applications of these
material in quantum information applications. Here we study the coherence
properties in a weakly doped erbium silica glass fiber motivated by our recent
observation of efficient and long-lived Zeeman sublevel storage in this
material and by its potential for applications at telecommunication
wavelengths. We analyze photon echo decays as well as the potential mechanisms
of spectral diffusion that can be caused by coupling with dynamic disorder
modes that are characteristic for glassy hosts, and by the magnetic
dipole-dipole interactions between $Er^{3+}$ ions. We also investigate the
effective linewidth as a function of magnetic field, temperature and time, and
then present a model that describes these experimental observations. We
highlight that the operating conditions (0.6 K and 0.05 T) at which we
previously observed efficient spectral hole burning coincide with those for
narrow linewidths (1 MHz) { an important property for applications that has not
been reported before for a rare-earth-ion doped glass.


title:
A Few Photons Among Many: Unmixing Signal and Noise for Photon-Efficient
  Active Imaging

abstract:
  Conventional LIDAR systems require hundreds or thousands of photon detections
to form accurate depth and reflectivity images. Recent photon-efficient
computational imaging methods are remarkably effective with only 1.0 to 3.0
detected photons per pixel, but they are not demonstrated at
signal-to-background ratio (SBR) below 1.0 because their imaging accuracies
degrade significantly in the presence of high background noise. We introduce a
new approach to depth and reflectivity estimation that focuses on unmixing
contributions from signal and noise sources. At each pixel in an image,
short-duration range gates are adaptively determined and applied to remove
detections likely to be due to noise. For pixels with too few detections to
perform this censoring accurately, we borrow data from neighboring pixels to
improve depth estimates, where the neighborhood formation is also adaptive to
scene content. Algorithm performance is demonstrated on experimental data at
varying levels of noise. Results show improved performance of both reflectivity
and depth estimates over state-of-the-art methods, especially at low
signal-to-background ratios. In particular, accurate imaging is demonstrated
with SBR as low as 0.04. This validation of a photon-efficient, noise-tolerant
method demonstrates the viability of rapid, long-range, and low-power LIDAR
imaging.


title:
Scale-free and quantitative unique continuation for infinite dimensional
  spectral subspaces of Schr\"odinger operators

abstract:
  We prove a quantitative unique continuation principle for infinite
dimensional spectral subspaces of Schr\"odinger operators. Let $\Lambda_L =
(-L/2,L/2)^d$ and $H_L = -\Delta_L + V_L$ be a Schr\"odinger operator on $L^2
(\Lambda_L)$ with a bounded potential $V_L : \Lambda_L \to \mathbb{R}^d$ and
Dirichlet, Neumann, or periodic boundary conditions. Our main result is of the
type
  \[
  \int_{\Lambda_L} \lvert \phi \rvert^2 \leq C_{\mathrm{sfuc}} \int_{W_\delta
(L)} \lvert \phi \rvert^2,
  \] where $\phi$ is an infinite complex linear combination of eigenfunctions
of $H_L$ with exponentially decaying coefficients, $W_\delta (L)$ is some union
of equidistributed $\delta$-balls in $\Lambda_L$ and $C_{\mathrm{sfuc}} > 0$ an
$L$-independent constant. The exponential decay condition on $\phi$ can
alternatively be formulated as an exponential decay condition of the map
$\lambda \mapsto \lVert \chi_{[\lambda , \infty)} (H_L) \phi \rVert^2$. The
novelty is that at the same time we allow the function $\phi$ to be from an
infinite dimensional spectral subspace and keep an explicit control over the
constant $C_{\mathrm{sfuc}}$ in terms of the parameters. Moreover, we show that
a similar result cannot hold under a polynomial decay condition.


title:
Q-Learning for Robust Satisfaction of Signal Temporal Logic
  Specifications

abstract:
  This paper addresses the problem of learning optimal policies for satisfying
signal temporal logic (STL) specifications by agents with unknown stochastic
dynamics. The system is modeled as a Markov decision process, in which the
states represent partitions of a continuous space and the transition
probabilities are unknown. We formulate two synthesis problems where the
desired STL specification is enforced by maximizing the probability of
satisfaction, and the expected robustness degree, that is, a measure
quantifying the quality of satisfaction. We discuss that Q-learning is not
directly applicable to these problems because, based on the quantitative
semantics of STL, the probability of satisfaction and expected robustness
degree are not in the standard objective form of Q-learning. To resolve this
issue, we propose an approximation of STL synthesis problems that can be solved
via Q-learning, and we derive some performance bounds for the policies obtained
by the approximate approach. The performance of the proposed method is
demonstrated via simulations.


title:
One-vs-Each Approximation to Softmax for Scalable Estimation of
  Probabilities

abstract:
  The softmax representation of probabilities for categorical variables plays a
prominent role in modern machine learning with numerous applications in areas
such as large scale classification, neural language modeling and recommendation
systems. However, softmax estimation is very expensive for large scale
inference because of the high cost associated with computing the normalizing
constant. Here, we introduce an efficient approximation to softmax
probabilities which takes the form of a rigorous lower bound on the exact
probability. This bound is expressed as a product over pairwise probabilities
and it leads to scalable estimation based on stochastic optimization. It allows
us to perform doubly stochastic estimation by subsampling both training
instances and class labels. We show that the new bound has interesting
theoretical properties and we demonstrate its use in classification problems.


title: Seas of squares with sizes from a $\Pi^0_1$ set

abstract:
  For each $\Pi^0_1$ $S\subseteq \mathbb{N}$, let the $S$-square shift be the
two-dimensional subshift on the alphabet $\{0,1\}$ whose elements consist of
squares of 1s of various sizes on a background of 0s, where the side length of
each square is in $S$. Similarly, let the distinct-square shift consist of seas
of squares such that no two finite squares have the same size. Extending the
self-similar Turing machine tiling construction of Durand, Romashchenko and
Shen, we show that if $X$ is an $S$-square shift or any effectively closed
subshift of the distinct square shift, then $X$ is sofic.


title: Reducing Streaking Artifacts in Quantitative Susceptibility Mapping

abstract:
  It is well-known that reconstruction algorithms in quantitative
susceptibility mapping often contain streaking artifacts. In [1], the cause of
the artifacts is identified as propagation of singularities. In this work, we
analyze such singularities carefully and propose some strategies to reduce the
artifacts.


title:
Four-body Dalitz plot contribution to the radiative corrections in
  K_{l3}^0 decays and its role in the determination of |V_{us}|

abstract:
  The four-body contribution of the model-independent radiative corrections to
the Dalitz plot of the semileptonic decays of neutral kaons are computed to
order (\alpha/\pi)(q/M_1), where q is the momentum transfer and M_1 is the kaon
mass. The final result is presented in two forms. The first one is given in
terms of the triple integration of the bremsstrahlung photon ready to be
performed numerically; the second one is a fully analytical expression. This
paper is organized to make it accessible and reliable in the analysis of the
Dalitz plot of precision experiments involving kaons and is not compromised to
fixing the form factors at predetermined values. As a byproduct, gathering
together three- and four-body contributions of radiative corrections yields,
through a least-squares fit to the measured kaon decay rates, the value
f_+^{K^0\pi^-}|V_{us}| = 0.2168(3).


title: Merging fluid and solid granular behavior

abstract:
  Simple homogeneous shear flows of frictionless, deformable particles are
studied by particle simulations at large shear rates and for differently soft,
deformable particles. The particle stiffness sets a time-scale that can be used
to scale the physical quantities; thus the dimensionless shear rate, i.e. the
inertial number (inversely proportional to pressure), can alternatively be
expressed as inversely proportional to the square root of the particle
stiffness. Asymptotic scaling relations for the field variables pressure, shear
stress and granular temperature are inferred from simulations in both fluid and
solid regimes, corresponding to unjammed and jammed conditions. Then the limit
cases are merged to unique constitutive relations that cover also the
transition zone in proximity of jamming. By exploiting the diverging behavior
of the scaling laws at the jamming density, we arrive at continuous and
differentiable phenomenological constitutive relations for the stresses and the
granular temperature as functions of the volume fraction, shear rate, particle
stiffness and distance from jamming. In contrast to steady shear flows of hard
particles the (shear) stress ratio does not collapse as a function of the
inertial number, indicating the need for an additional control parameter. In
the range of particle stiffnesses investigated, in the solid regime, only the
pressure is rate independent, whereas the shear stress exhibits a slight shear
rate- and stiffness-dependency.


title:
On the Non-Existence of Unbiased Estimators in Constrained Estimation
  Problems

abstract:
  We address the problem of existence of unbiased constrained parameter
estimators. We show that if the constrained set of parameters is compact and
the hypothesized distributions are absolutely continuous with respect to one
another, then there exists no unbiased estimator. Weaker conditions for the
absence of unbiased constrained estimators are also specified. We provide
several examples which demonstrate the utility of these conditions.


title: 3D NLTE analysis of the most iron-deficient star, SMSS0313-6708

abstract:
  Models of star formation in the early universe depend on the details of
accretion, fragmentation and radiative feedback. Different simulations predict
different initial mass functions of the first stars, ranging from predominantly
low mass (0.1-10 Msol), to massive (10-100 Msol), or even supermassive
(100-1000 Msol). The mass distribution of the first stars should lead to unique
chemical imprints on the low-mass second and later generation metal-poor stars
still in existence. The chemical composition of SMSS0313-6708, which has the
lowest abundances of Ca and Fe of any star known, indicates it was enriched by
a single massive supernova. However, even weak spectral lines may be affected
by strong 3D and NLTE effects in metal-poor stars. If these effects are ignored
or treated incorrectly, errors in the inferred abundances may significantly
bias the inferred properties of the polluting supernovae. We redetermine the
chemical composition of SMSS0313-6708 using 3D NLTE radiative transfer to
obtain accurate abundances for Li, Na, Mg, Al, Ca and Fe. The model atoms
employ realistic collisional rates, with no calibrated free parameters. We find
significantly higher abundances in 3D NLTE than 1D LTE by 0.8 dex for Fe, and
0.5 dex for Mg, Al and Ca, while Li and Na are unaffected to within 0.03 dex.
In particular, our upper limit for [Fe/H] is now a factor ten larger, at [Fe/H]
< -6.53 (3 sigma), than previous estimates based on <3D> NLTE (i.e. using
averaged 3D models). This higher estimate is due to a conservative upper limit
estimation, updated NLTE data, and 3D-<3D> NLTE differences, all of which lead
to a higher abundance determination. We find that the revised chemical
composition of SMSS0313-6708 matches supernova yields for massive progenitors
of 20-60 Msol exploding with low energies (1-2 x 10^51 erg), as well as
progenitors of 10 Msol with very low explosion energies (< 10^51 erg).


title: PDFs, $\alpha_s$, and quark masses from global fits

abstract:
  The strong coupling constant $\alpha_s$ and the heavy-quark masses, $m_c$,
$m_b$, $m_t$ are extracted simultaneosly with the parton distribution functions
(PDFs) in the updated ABM12 fit including recent data from CERN-SPS, HERA,
Tevatron, and the LHC. The values of \begin{eqnarray} \nonumber
\alpha_s(M_Z)&=&0.1147\pm0.0008~({\rm exp.)},\\ \nonumber m_c(m_c)&=&1.252\pm
0.018~({\rm exp.})~{\rm GeV},\\ \nonumber m_b(m_b)&=&3.83\pm0.12~({\rm
exp.})~{\rm GeV},\\ \nonumber m_t(m_t)&=&160.9\pm1.1~({\rm exp.})~{\rm GeV}
\end{eqnarray} are obtained with the $\overline{MS}$ heavy-quark mass
definition being employed throughout the analysis.


title:
Estimates of the $L^p$ norms of the Bergman projection on strongly
  pseudoconvex domains

abstract:
  We give estimates of the $L^p$ norm of the Bergman projection on a strongly
pseudoconvex domain in $\mathbb{C}^n$. We show that this norm is comparable to
$\frac{p^2}{p - 1}$ for $1 <p< \infty$.


title: Watermark Options

abstract:
  We consider a new family of derivatives whose payoffs become strictly
positive when the price of their underlying asset falls relative to its
historical maximum. We derive the solution to the discretionary stopping
problems arising in the context of pricing their perpetual American versions by
means of an explicit construction of their value functions. In particular, we
fully characterise the free-boundary functions that provide the optimal
stopping times of these genuinely two-dimensional problems as the unique
solutions to highly non-linear first order ODEs that have the characteristics
of a separatrix. The asymptotic growth of these free-boundary functions can
take qualitatively different forms depending on parameter values, which is an
interesting new feature.


title:
Real-time Human Pose Estimation from Video with Convolutional Neural
  Networks

abstract:
  In this paper, we present a method for real-time multi-person human pose
estimation from video by utilizing convolutional neural networks. Our method is
aimed for use case specific applications, where good accuracy is essential and
variation of the background and poses is limited. This enables us to use a
generic network architecture, which is both accurate and fast. We divide the
problem into two phases: (1) pre-training and (2) finetuning. In pre-training,
the network is learned with highly diverse input data from publicly available
datasets, while in finetuning we train with application specific data, which we
record with Kinect. Our method differs from most of the state-of-the-art
methods in that we consider the whole system, including person detector, pose
estimator and an automatic way to record application specific training material
for finetuning. Our method is considerably faster than many of the
state-of-the-art methods. Our method can be thought of as a replacement for
Kinect, and it can be used for higher level tasks, such as gesture control,
games, person tracking, action recognition and action tracking. We achieved
accuracy of 96.8\% (PCK@0.2) with application specific data.


title:
Delocalising the parabolic Anderson model through partial duplication of
  the potential

abstract:
  The parabolic Anderson model on $\mathbb{Z}^d$ with i.i.d. potential is known
to completely localise if the distribution of the potential is sufficiently
heavy-tailed at infinity. In this paper we investigate a modification of the
model in which the potential is partially duplicated in a symmetric way across
a plane through the origin. In the case of potential distribution with
polynomial tail decay, we exhibit a surprising phase transition in the model as
the decay exponent varies. For large values of the exponent the model
completely localises as in the i.i.d. case. By contrast, for small values of
the exponent we show that the model may delocalise. More precisely, we show
that there is an event of non-negligible probability on which the solution has
non-negligible mass on two sites.


title: Heavy quark fragmentation functions at next-to-leading perturbative QCD

abstract:
  It is well-known that the dominant mechanism to produce hadronic bound states
with large transverse momentum is fragmentation. This mechanism is described by
the fragmentation functions (FFs) which are the universal and
process-independent functions. Here, we review the perturbative FFs formalism
as an appropriate tool for studying these hadronization processes and detail
the extension of this formalism at next-to-leading order (NLO). Using the
Suzuki's model, we calculate the perturbative QCD FF for a heavy quark to
fragment into a S-wave heavy meson at NLO. As an example, we study the LO and
NLO FFs for a charm quark to split into the S-wave $D$-meson and compare our
analytic results both with experimental data and well-known phenomenological
models.


title:
Functional Renormalization Group Approach for Inhomogeneous
  One-Dimensional Fermi Systems with Finite-Ranged Interactions

abstract:
  We introduce an equilibrium formulation of the functional renormalization
group (fRG) for inhomogeneous systems capable of dealing with spatially
finite-ranged interactions. In the general third order truncated form of fRG,
the dependence of the two-particle vertex is described by O(N^4) independent
variables, where N is the dimension of the single-particle system. In a
previous paper [Phys. Rev. B 89, 045128 (2014)], the so-called coupled-ladder
approximation (CLA) was introduced and shown to admit a consistent treatment
for models with a purely onsite interaction, reducing the vertex to O(N^2)
independent variables. Here, we extend this scheme to the extended coupled
ladder approximation (eCLA), which includes a spatially extended feedback
between the individual channels, measured by a feedback length L, using O(N^2
L^2) independent variables for the vertex. We apply the eCLA to three types of
one-dimensional models : First, to a quantum point contact (QPC) with a
parabolic barrier top and short-ranged interactions. Here eCLA achieves
convergence for L equal to the characteristic length l_x of the QPC. It also
turns out that the additional feedback stabilizes the fRG-flow. This enables
us, second, to study the crossover between a QPC and a quantum dot, again for a
model with short-ranged interactions. Third, the enlarged feedback also enables
the treatment of a finite-ranged interaction extending over up to L sites.
Estimating the form of such a finite-ranged interaction in a QPC, we study its
effects on the conductance and the density. For low densities and sufficiently
large interaction ranges the conductance develops additional oscillatory
features, and the corresponding density shows fluctuations that can be
interpreted as Friedel oscillations arising from a renormalized barrier shape
with a rather flat top and steep flanks.


title: On a Very Steep Version of the Standard Map

abstract:
  We consider the long time behavior of the trajectories of the discontinuous
analog of the standard Chirikov map. We prove that for some values of
parameters all the trajectories remains bounded for all time. For other set of
parameters we provide an estimate for the escape rate for the trajectories and
present a numerically supported conjecture for the actual escape rate.


title: The mechanism of spin-orbit coupling in a 2D oxide interface

abstract:
  The presence of spin-orbit coupling drives the anomalous magnetotransport at
oxide interfaces and forms the basis for numerous intriguing properties of
these 2D electron systems, such as topologically protected phases or
anti-localization. For many of those systems, the identification of the
underlying coupling mechanism is obfuscated by multi-band effects. We therefore
analyze the transport of LaAlO$_3$/SrTiO$_3$ interfaces under high pressures, a
technique to single out the multi-band contributions. We argue that the
observed magnetoresistance is due to quantum interference and not related to
Coulomb interaction. Therefore, this system is an excellent candidate to
generate a metal-insulator transition of the long-sought symplectic 2D
universality class. It is shown that the spin-orbit coupling can be linked
unambiguously to the band structure with a cubic (Dresselhaus-like) rather than
a linear (Rashba-like) spin-orbit band splitting.


title:
Modeling of Sensory Characteristics Based on the Growth of Food Spoilage
  Bacteria

abstract:
  During last years theoretical works shed new light and proposed new
hypothesis on the mechanisms which regulate the time behaviour of biological
populations in different natural systems. Despite of this, the role of
environmental variables in ecological systems is still an open question.
Filling this gap of knowledge is a crucial task for a deeper comprehension of
the dynamics of biological populations in real ecosystems. In this work we
study how the dynamics of food spoilage bacteria influences the sensory
characteristics of fresh fish specimens. This topic is crucial for a better
understanding of the role played by the bacterial growth on the organoleptic
properties, and for the quality evaluation and risk assessment of food
products. We therefore analyze the time behaviour, in fresh fish specimens, of
sensory characteristics starting from the growth curves of two spoilage
bacterial communities. The theoretical study, initially based on a
deterministic model, exploits experimental temperature profiles. As a first
step, a model of predictive microbiology is used to reproduce the experimental
behaviour of the two bacterial populations. Afterwards, the theoretical
bacterial growths are converted, through suitable differential equations, into
"sensory" scores, based on the Quality Index Method (QIM), a scoring system for
freshness and quality sensory estimation of fishery products. As a third step,
the theoretical curves of QIM scores are compared with the experimental data
obtained by sensory analysis. Finally, the differential equations for QIM
scores are modified by adding terms of multiplicative white noise, which mimics
the effects of uncertainty and variability in sensory analysis. A better
agreement between experimental and theoretical QIM scores is observed, in some
cases, in the presence of suitable values of noise intensity respect to the
deterministic analysis.


title:
Channel Estimation and Performance Analysis of One-Bit Massive MIMO
  Systems

abstract:
  This paper considers channel estimation and system performance for the uplink
of a single-cell massive multiple-input multiple-output (MIMO) system. Each
receive antenna of the base station (BS) is assumed to be equipped with a pair
of one-bit analog-to-digital converters (ADCs) to quantize the real and
imaginary part of the received signal. We first propose an approach for channel
estimation that is applicable for both flat and frequency-selective fading,
based on the Bussgang decomposition that reformulates the nonlinear quantizer
as a linear functionwith identical first- and second-order statistics. The
resulting channel estimator outperforms previously proposed approaches across
all SNRs. We then derive closed-form expressions for the achievable rate in
flat fading channels assuming low SNR and a large number of users for the
maximal ratio and zero forcing receivers that takes channel estimation error
due to both noise and one-bit quantization into account. The closed-form
expressions in turn allow us to obtain insight into important system design
issues such as optimal resource allocation, maximal sum spectral efficiency,
overall energy efficiency, and number of antennas. Numerical results are
presented to verify our analytical results and demonstrate the benefit of
optimizing system performance accordingly.


title:
Convergence Rate Analysis of a Stochastic Trust Region Method via
  Submartingales

abstract:
  We propose a novel framework for analyzing convergence rates of stochastic
optimization algorithms with adaptive step sizes. This framework is based on
analyzing properties of an underlying generic stochastic process, in particular
by deriving a bound on the expected stopping time of this process. We utilize
this framework to analyze the bounds on expected global convergence rates of a
stochastic variant of a traditional trust region method, introduced in
\cite{ChenMenickellyScheinberg2014}. While traditional trust region methods
rely on exact computations of the gradient, Hessian and values of the objective
function, this method assumes that these values are available up to some
dynamically adjusted accuracy. Moreover, this accuracy is assumed to hold only
with some sufficiently large, but fixed, probability, without any additional
restrictions on the variance of the errors. This setting applies, for example,
to standard stochastic optimization and machine learning formulations.
Improving upon the analysis in \cite{ChenMenickellyScheinberg2014}, we show
that the stochastic process defined by the algorithm satisfies the assumptions
of our proposed general framework, with the stopping time defined as reaching
accuracy $\|\nabla f(x)\|\leq \epsilon$. The resulting bound for this stopping
time is $O(\epsilon^{-2})$, under the assumption of sufficiently accurate
stochastic gradient, and is the first global complexity bound for a stochastic
trust-region method. Finally, we apply the same framework to derive second
order complexity bound under some additional assumptions.


title: A Fast Algorithm for Convolutional Structured Low-Rank Matrix Recovery

abstract:
  Fourier domain structured low-rank matrix priors are emerging as powerful
alternatives to traditional image recovery methods such as total variation and
wavelet regularization. These priors specify that a convolutional structured
matrix, i.e., Toeplitz, Hankel, or their multi-level generalizations, built
from Fourier data of the image should be low-rank. The main challenge in
applying these schemes to large-scale problems is the computational complexity
and memory demand resulting from lifting the image data to a large scale
matrix. We introduce a fast and memory efficient approach called the Generic
Iterative Reweighted Annihilation Filter (GIRAF) algorithm that exploits the
convolutional structure of the lifted matrix to work in the original un-lifted
domain, thus considerably reducing the complexity. Our experiments on the
recovery of images from undersampled Fourier measurements show that the
resulting algorithm is considerably faster than previously proposed algorithms,
and can accommodate much larger problem sizes than previously studied.


title: Charmless Non-Leptonic Multi-Body B decays

abstract:
  I review the theoretical and phenomenological status of two- and three-body
charmless non-leptonic B decays, with an emphasis on factorization approaches.
Most of the material presented here is based on talks given by the participants
of the workshop "Future Challenges in Non-Leptonic B Decays: Theory and
Experiment", held at Bad Honnef in February 2016.


title: An unbiased Monte Carlo estimator for derivatives. Application to CIR

abstract:
  In this paper, we present extensions of the exact simulation algorithm
introduced by Beskos et al. (2006). First, a modification in the order in which
the simulation is done accelerates the algorithm. In addition, we propose a
truncated version of the modified algorithm. We obtain a control of the bias of
this last version, exponentially small in function of the truncation parameter.
Then, we extend it to more general drift functions. Our main result is an
unbiased algorithm to approximate the two first derivatives with respect to the
initial condition \(x\) of quantities with the form \(\mathbb{E}\Psi(X_T^x)\).
We describe it in details in dimension 1 and also discuss its multi-dimensional
extensions for the evaluation of \(\mathbb{E}\Psi(X_T^x)\). Finally, we apply
the algorithm to the CIR process and perform numerical tests to compare it with
classical approximation procedures.


title:
User interfaces for computational science: a domain specific language
  for OOMMF embedded in Python

abstract:
  Computer simulations are used widely across the engineering and science
disciplines, including in the research and development of magnetic devices
using computational micromagnetics. In this work, we identify and review
different approaches to configuring simulation runs: (i) the re-compilation of
source code, (ii) the use of configuration files, (iii) the graphical user
interface, and (iv) embedding the simulation specification in an existing
programming language to express the computational problem. We identify the
advantages and disadvantages of different approaches and discuss their
implications on effectiveness and reproducibility of computational studies and
results. Following on from this, we design and describe a domain specific
language for micromagnetics that is embedded in the Python language, and allows
users to define the micromagnetic simulations they want to carry out in a
flexible way. We have implemented this micromagnetic simulation description
language together with a computational backend that executes the simulation
task using the Object Oriented MicroMagnetic Framework (OOMMF). We illustrate
the use of this Python interface for OOMMF by solving the micromagnetic
standard problem 4. All the code is publicly available and is open source.


title:
Simultaneous suppression of scattering and aberration for ultra-high
  resolution imaging deep within scattering media

abstract:
  Thick biological tissues give rise to not only the scattering of incoming
light waves, but also aberrations of the remaining unscattered waves. Due to
the inability of existing optical imaging methodologies to overcome both of
these problems simultaneously, imaging depth at the sub- micron spatial
resolution has remained extremely shallow. Here we present an experimental
approach for identifying and eliminating aberrations even in the presence of
strong multiple light scattering. For time-gated complex-field maps of
reflected waves taken over various illumination channels, we identify two sets
of aberration correction maps, one for the illumination path and one for the
reflection path, that can preferentially accumulate the unscattered signal
waves over the multiple-scattered waves. By performing closed-loop optimization
for forward and phase- conjugation processes, we demonstrated a spatial
resolution of 600 nm up to the unprecedented imaging depth of 7 scattering mean
free paths.


title:
Regulating Reward Training by Means of Certainty Prediction in a Neural
  Network-Implemented Pong Game

abstract:
  We present the first reinforcement-learning model to self-improve its
reward-modulated training implemented through a continuously improving
"intuition" neural network. An agent was trained how to play the arcade video
game Pong with two reward-based alternatives, one where the paddle was placed
randomly during training, and a second where the paddle was simultaneously
trained on three additional neural networks such that it could develop a sense
of "certainty" as to how probable its own predicted paddle position will be to
return the ball. If the agent was less than 95% certain to return the ball, the
policy used an intuition neural network to place the paddle. We trained both
architectures for an equivalent number of epochs and tested learning
performance by letting the trained programs play against a near-perfect
opponent. Through this, we found that the reinforcement learning model that
uses an intuition neural network for placing the paddle during reward training
quickly overtakes the simple architecture in its ability to outplay the
near-perfect opponent, additionally outscoring that opponent by an increasingly
wide margin after additional epochs of training.


title:
Discovery of a Possible Cool White Dwarf Companion from the AllWISE
  Motion Survey

abstract:
  We present optical and near-infrared spectroscopy of WISEA
J061543.91$-$124726.8, which we rediscovered as a high motion object in the
AllWISE survey. The spectra of this object are unusual; while the red optical
($\lambda >$ 7,000 \AA) and near-infrared spectra exhibit characteristic TiO,
VO, and H$_{2}$O bands of a late-M dwarf, the blue portion of its optical
spectrum shows a significant excess of emission relative to late-M type
templates. The excess emission is relatively featureless, with the exception of
a prominent and very broad Na I D doublet. We find that no single, ordinary
star can reproduce these spectral characteristics. The most likely explanation
is an unresolved binary system of an M7 dwarf and a cool white dwarf. The flux
of a cool white dwarf drops in the optical red and near-infrared, due to
collision-induced absorption, thus allowing the flux of a late-M dwarf to show
through. This scenario, however, does not explain the Na D feature, which is
unlike that of any known white dwarf, but which could perhaps be explained via
unusual abundance or pressure conditions.


title: UAV attitude estimation using Unscented Kalman Filter and TRIAD

abstract:
  A main problem in autonomous vehicles in general, and in \acp{UAV} in
particular, is the determination of the attitude angles. A novel method to
estimate these angles using off-the-shelf components is presented. This paper
introduces an \ac{AHRS} based on the \ac{UKF} using the \ac{TRIAD} algorithm as
the observation model. The performance of the method is assessed through
simulations and compared to an \ac{AHRS} based on the \ac{EKF}. The paper
presents field experiment results using a real fixed-wing \ac{UAV}. The results
show good real-time performance with low computational cost in a
microcontroller.


title: Distributed scaling control of rigid formations

abstract:
  Recently it has been reported that biased range-measurements among
neighboring agents in the gradient distance-based formation control can lead to
predictable collective motion. In this paper we take advantage of this effect
and by introducing distributed parameters to the prescribed inter-distances we
are able to manipulate the steady-state motion of the formation. This
manipulation is in the form of inducing simultaneously the combination of
constant translational and angular velocities and a controlled scaling of the
rigid formation. While the computation of the distributed parameters for the
translational and angular velocities is based on the well-known graph rigidity
theory, the parameters responsible for the scaling are based on some recent
findings in bearing rigidity theory. We carry out the stability analysis of the
modified gradient system and simulations in order to validate the main result.


title: Poisson-Lie groups, bi-Hamiltonian systems and integrable deformations

abstract:
  Given a Lie-Poisson completely integrable bi-Hamiltonian system on
$\mathbb{R}^n$, we present a method which allows us to construct, under certain
conditions, a completely integrable bi-Hamiltonian deformation of the initial
Lie-Poisson system on a non-abelian Poisson-Lie group $G_\eta$ of dimension
$n$, where $\eta \in \mathbb{R}$ is the deformation parameter. Moreover, we
show that from the two multiplicative (Poisson-Lie) Hamiltonian structures on
$G_\eta$ that underly the dynamics of the deformed system and by making use of
the group law on $G_\eta$, one may obtain two completely integrable Hamiltonian
systems on $G_\eta \times G_\eta$. By construction, both systems admit
reduction, via the multiplication in $G_\eta$, to the deformed bi-Hamiltonian
system in $G_\eta$. The previous approach is applied to two relevant
Lie-Poisson completely integrable bi-Hamiltonian systems: the Lorenz and Euler
top systems.


title: Gershgorin disks for multiple eigenvalues of non-negative matrices

abstract:
  Gershgorin's famous circle theorem states that all eigenvalues of a square
matrix lie in disks (called Gershgorin disks) around the diagonal elements.
Here we show that if the matrix entries are non-negative and an eigenvalue has
geometric multiplicity at least two, then this eigenvalue lies in a smaller
disk. The proof uses geometric rearrangement inequalities on sums of higher
dimensional real vectors which is another new result of this paper.


title:
Gravitational lens system SDSS J1339+1310: microlensing factory and time
  delay

abstract:
  We spectroscopically re-observed the gravitational lens system SDSS
J1339+1310 using OSIRIS on the GTC. We also monitored the $r$-band variability
of the two quasar images (A and B) with the LT over 143 epochs in the period
2009$-$2016. These new data in both the wavelength and time domains have
confirmed that the system is an unusual microlensing factory. The
C$\scriptsize{\rm{IV}}$ emission line is remarkably microlensed, since the
microlensing magnification of B relative to that for A, $\mu_{\rm{BA}}$,
reaches a value of 1.4 ($\sim$ 0.4 mag) for its core. Moreover, the B image
shows a red wing enhancement of C$\scriptsize{\rm{IV}}$ flux (relative to A),
and $\mu_{\rm{BA}}$ = 2 (0.75 mag) for the C$\scriptsize{\rm{IV}}$ broad-line
emission. Regarding the nuclear continuum, we find a chromatic behaviour of
$\mu_{\rm{BA}}$, which roughly varies from $\sim$ 5 (1.75 mag) at 7000 \AA\ to
$\sim$ 6 (1.95 mag) at 4000 \AA. We also detect significant microlensing
variability in the $r$ band, and this includes a number of microlensing events
on timescales of 50$-$100 d. Fortunately, the presence of an intrinsic 0.7 mag
dip in the light curves of A and B, permitted us to measure the time delay
between both quasar images. This delay is $\Delta t_{\rm{AB}}$ = 47$^{+5}_{-6}$
d (1$\sigma$ confidence interval; A is leading), in good agreement with
predictions of lens models.


title:
Parallelization of JOREK-STARWALL for non-linear MHD simulations
  including resistive walls (Report of the EUROfusion High Level Support Team
  Projects JORSTAR/JORSTAR2)

abstract:
  Large scale plasma instabilities inside a tokamak can be influenced by the
currents flowing in the conducting vessel wall. This involves non linear plasma
dynamics and its interaction with the wall current. In order to study this
problem the code that solves the magneto-hydrodynamic (MHD) equations, called
JOREK [Huysmans G.T.A. and Czarny O. NF 47, 659 (2007); Czarny O. and Huysmans
G. JCP 227, 7423 (2008)], was coupled [Hoelzl M., et al. Journal of Physics:
Conference Series, 401, 012010 (2012)] with the model for the vacuum region and
the resistive conducting structure named STARWALL [Merkel P., Strumberger E.,
arXiv:150804911 (2015)]. The JOREK-STARWALL model has been already applied to
perform simulations of Vertical Displacement Events (VDEs), Resistive Wall
Modes (RWMs), Quiescent H-Mode, and vertical kick ELM triggering. At the
beginning of the project it was not possible to resolve the realistic wall
structure with a large number of finite element triangles due to the huge
consumption of memory and wall clock time by STARWALL and the corresponding
coupling routine in JOREK. Moreover, both the STARWALL code and the JOREK
coupling routine were only partially parallelized via OpenMP. The aim of this
project is to implement an MPI parallelization to reduce memory consumption and
execution time such that simulations with large resolutions become possible.


title: A vielbein formulation of unified Einstein-Maxwell theory

abstract:
  In the framework of J-bundles a vielbein formulation of unified
Einstein-Maxwell theory is proposed. In the resulting scheme, field equations
matching the gravitational and electromagnetic fields are derived by
constraining a five-dimensional variational principle. No dynamical scalar
field is involved.


title: Localization on $AdS_2\times S^1$

abstract:
  Conformal symmetry relates the metric on $AdS_2 \times S^{1}$ to that of
$S^3$. This implies that under a suitable choice of boundary conditions for
fields on $AdS_2$ the partition function of conformal field theories on these
spaces must agree which makes $AdS_2 \times S^{1}$ a good testing ground to
study localization on non-compact spaces. We study supersymmetry on
$AdS_2\times S^1$ and determine the localizing Lagrangian for ${\cal N}=2$
supersymmetric Chern-Simons theory on $AdS_2\times S^1$. We evaluate the
partition function of ${\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2
\times S^1$ using localization, where the radius of $S^1$ is $q$ times that of
$AdS_2$. With boundary conditions on $AdS_2\times S^1$ which ensure that all
the physical fields are normalizable and lie in the space of square integrable
wave functions in $AdS_2$, the result for the partition function precisely
agrees with that of the theory on the $q$-fold covering of $S^3$.


title:
Quasi-Monte Carlo for an Integrand with a Singularity along a Diagonal
  in the Square

abstract:
  Quasi-Monte Carlo methods are designed for integrands of bounded variation,
and this excludes singular integrands. Several methods are known for integrands
that become singular on the boundary of the unit cube $[0,1]^d$ or at isolated
possibly unknown points within $[0,1]^d$. Here we consider functions on the
square $[0,1]^2$ that may become singular as the point approaches the diagonal
line $x_1=x_2$, and we study three quadrature methods. The first method splits
the square into two triangles separated by a region around the line of
singularity, and applies recently developed triangle QMC rules to the two
triangular parts. For functions with a singularity `no worse than
$|x_1-x_2|^{-A}$ for $0<A<1$ that method yields an error of $O(
(\log(n)/n)^{(1-A)/2})$. We also consider methods extending the integrand into
a region containing the singularity and show that method will not improve up on
using two triangles. Finally, we consider transforming the integrand to have a
more QMC-friendly singularity along the boundary of the square. This then leads
to error rates of $O(n^{-1+\epsilon+A})$ when combined with some
corner-avoiding Halton points or with randomized QMC, but it requires some
stronger assumptions on the original singular integrand.


title: Squark/gluino searches in hadronic channels with CMS

abstract:
  These proceedings summarize the results of four analyses which searched for
squarks and gluinos in hadronic final states with missing transverse momentum
in 2.3 fb$^{-1}$ of data in proton-proton collisions at $\sqrt{s}=13$ TeV
collected in the year 2015 with the CMS detector at the CERN LHC. Each analysis
is characterized by a different kinematic variable that is sensitive to the
presence of invisible particles, e.g., $M_\text{T2}$, $\alpha_{\text{T}}$, and
razor variables. We observed no significant deviation from the standard model
prediction and placed limits on the production cross sections and the masses of
squarks and gluinos in simplified models of supersymmetric models. The limits
are significantly extended from the previous results.


title: On the geometric structure of certain real algebraic surfaces

abstract:
  In this paper we study the affine geometric structure of the graph of a
polynomial $f \in \mathbb{R} [x,y]$. We provide certain criteria to determine
when the parabolic curve is compact and when the unbounded component of its
complement is hyperbolic or elliptic. We analyse the extension to the real
projective plane of both fields of asymptotic lines and the Poincar\'e index of
its singular points when the surface is generic. Thus, we exhibit an index
formula for the field of asymptotic lines involving the number of connected
components of the projective Hessian curve of $f$ and the number of the special
parabolic points. As an application of this investigation, we obtain upper
bounds, respectively, for the number of special parabolic points having an
interior tangency and when they have an exterior tangency.


title:
Variational techniques in general relativity: A metric-affine approach
  to Kaluza's theory

abstract:
  A new variational principle for General Relativity, based on an action
functional $I\/(\Phi,\nabla)\/$ involving both the metric $\Phi\/$ and the
connection $\nabla\/$ as independent, \emph{unconstrained\/} degrees of freedom
is presented. The extremals of $I\/$ are seen to be pairs $\/(\Phi,\nabla)\/$
in which $\Phi\/$ is a Ricci flat metric, and $\nabla\/$ is the associated
Riemannian connection. An application to Kaluza's theory of interacting
gravitational and electromagnetic fields is discussed.


title:
Effect of Bonus Payments in Cost Sharing Mechanism Design for Renewable
  Energy Aggregation

abstract:
  The participation of renewable energy sources in energy markets is
challenging, mainly because of the uncertainty associated with the renewables.
Aggregation of renewable energy suppliers is shown to be very effective in
decreasing this uncertainty. In the present paper, we propose a cost sharing
mechanism that entices the suppliers of wind, solar and other renewable
resources to form or join an aggregate. In particular, we consider the effect
of a bonus for surplus in supply, which is neglected in previous work. We
introduce a specific proportional cost sharing mechanism, which satisfies the
desired properties of such mechanisms that are introduced in the literature,
e.g., budget balancedness, ex-post individual rationality and fairness. In
addition, we show that the proposed mechanism results in a stable market
outcome. Finally, the results of the paper are illustrated by numerical
examples.


title:
Floating rigid bodies: a note on the conservativeness of the hydrostatic
  effects

abstract:
  Within the framework of Lagrangian mechanics, the conservativeness of the
hydrostatic forces acting on a floating rigid body is proved. The
representation of the associated hydrostatic potential is explicitly worked
out. The invariance of the resulting Lagrangian with respect surge, sway and
yaw motions is used in connection with the Routh procedure in order to convert
the original dynamical problem into a reduced one, in three independent
variables. This allows to put on rational grounds the study of hydrostatic
equilibrium, introducing the concept of pseudo--stability, meant as stability
with respect to the reduced problem. The small oscillations of the system
around a pseudo-stable equilibrium configuration are discussed.


title:
Finding long simple paths in a weighted digraph using pseudo-topological
  orderings

abstract:
  Given a weighted digraph D, finding the longest simple path is well known to
be NP-hard. Furthermore, even giving an approximation algorithm is known to be
NP-hard. In this paper we describe an efficient heuristic algorithm for finding
long simple paths, using an hybrid approach of DFS and pseudo-topological
orders, a a generalization of topological orders to non acyclic graphs, via a
process we call "opening edges". An implementation of this algorithm won the
Oracle MDC 2015 coding competition.


title: AMR-to-text generation as a Traveling Salesman Problem

abstract:
  The task of AMR-to-text generation is to generate grammatical text that
sustains the semantic meaning for a given AMR graph. We at- tack the task by
first partitioning the AMR graph into smaller fragments, and then generating
the translation for each fragment, before finally deciding the order by solving
an asymmetric generalized traveling salesman problem (AGTSP). A Maximum Entropy
classifier is trained to estimate the traveling costs, and a TSP solver is used
to find the optimized solution. The final model reports a BLEU score of 22.44
on the SemEval-2016 Task8 dataset.


title:
A Wald-type test statistic for testing linear hypothesis in logistic
  regression models based on minimum density power divergence estimator

abstract:
  In this paper a robust version of the classical Wald test statistics for
linear hypothesis in the logistic regression model is introduced and its
properties are explored. We study the problem under the assumption of random
covariates although some ideas with non random covariates are also considered.
The family of tests considered is based on the minimum density power divergence
estimator instead of the maximum likelihood estimator and it is referred to as
the Wald-type test statistic in the paper. We obtain the asymptotic
distribution and also study the robustness properties of the Wald type test
statistic. The robustness of the tests is investigated theoretically through
the influence function analysis as well as suitable practical examples. It is
theoretically established that the level as well as the power of the Wald-type
tests are stable against contamination, while the classical Wald type test
breaks down in this scenario. Some classical examples are presented which
numerically substantiate the theory developed. Finally a simulation study is
included to provide further confirmation of the validity of the theoretical
results established in the paper.


title: Shear viscosity of nuclear matter

abstract:
  Shear viscosity $\eta$ is calculated for the nuclear matter described as a
system of interacting nucleons with the van der Waals (VDW) equation of state.
The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of
the collective overdamped motion. In the frequent-collision regime, the shear
viscosity depends on the particle-number density $n$ through the mean-field
parameter $a$, which describes attractive forces in the VDW equation. In the
temperature region $T=15 - 40$~MeV, a ratio of the shear viscosity to the
entropy density $s$ is smaller than 1 at the nucleon number density $n =(0.5 -
1.5)\,n^{}_0$, where $n^{}_0=0.16\,$fm$^{-3}$ is the particle density of
equilibrium nuclear matter at zero temperature. A minimum of the $\eta/s$ ratio
takes place somewhere in a vicinity of the critical point of the VDW system.
Large values of $\eta/s\gg 1$ are, however, found in both the low-density,
$n\ll n^{}_0$, and high-density, $n>2n^{}_0$, regions. This makes the ideal
hydrodynamic approach inapplicable for these densities.


title:
Hearing pseudoconvexity in Lipschitz domains with holes via
  $\overline\partial$

abstract:
  Let $\Omega=\widetilde{\Omega}\setminus \overline{D}$ where
$\widetilde{\Omega}$ is a bounded domain with connected complement in $\mathbb
C^n$ (or more generally in a Stein manifold) and $D$ is relatively compact open
subset of $\widetilde{\Omega}$ with connected complement in
$\widetilde{\Omega}$. We obtain characterizations of pseudoconvexity of
$\widetilde{\Omega}$ and $D$ through the vanishing or Hausdorff property of the
Dolbeault cohomology groups on various function spaces. In particular, we show
that if the boundaries of $\widetilde{\Omega}$ and $D$ are Lipschitz and
$C^2$-smooth respectively, then both $\widetilde{\Omega}$ and $D$ are
pseudoconvex if and only if $0$ is not in the spectrum of the
$\overline\partial$-Neumann Laplacian on $(0, q)$-forms for $1\le q\le n-2$
when $n\geq 3$; or $0$ is not a limit point of the spectrum of the
$\overline\partial$-Neumannn Laplacian on $(0, 1)$-forms when $n=2$.


title: Tropicalizing Spherical Embeddings

abstract:
  Recently, a theory for the tropicalization of a spherical homogeneous space
$G/H$ was developed by Tassos Vogiannou. We extend his ideas to define the
tropicalization of a spherical $G/H$-embedding. This generalizes the
construction of tropicalization of toric varieties. We also extend an alternate
definition of spherical tropicalization via Gr\"obner theory developed by
Kiumars Kaveh and Christopher Manon and show that the two notions of extended
tropicalization coincide.


title: Bounds on multiplicities of spherical spaces over finite fields

abstract:
  Let $G$ be a reductive group scheme of type $A$ acting on a spherical scheme
$X$. We prove that there exists a number $C$ such that the multiplicity $\dim
Hom(\rho,\mathbb{C}[X(F)])$ is bounded by $C$, for any finite field $F$ and any
irreducible representation $\rho$ of $G(F)$. We give an explicit bound for $C$.
  We conjecture that this result is true for any reductive group scheme and
when $F$ ranges (in addition) over all local fields of characteristic $0$.


title:
Simulated Cu-Zr glassy alloys: the impact of composition on icosahedral
  order

abstract:
  The structural properties of the simulated $\rm Cu_{\alpha}Zr_{1-\alpha}$
glassy alloys are studied in the wide range of the copper concentration
$\alpha$ to clarify the impact of the composition on the number density of the
icosahedral clusters. Both bond orientational order parameters and Voronoi
tessellation methods are used to identify these clusters. Our analysis shows
that abundance of the icosahedral clusters and the chemical composition of
these clusters are essentially non monotonic versus $\alpha$ and demonstrate
local extrema. That qualitatively explains the existence of pinpoint
compositions of high glass-forming ability observing in Cu-Zr alloys. Finally,
it has been shown that Voronoi method overestimates drastically the abundance
of the icosahedral clusters in comparison with the bond orientational order
parameters one.


title: Conformal symmetry of electron-hole puddles in ungated graphene

abstract:
  In this paper the mono-layer graphene at the charge neutrality point is
considered whithin Thomas-Fermi-Dirac theory, treating inhomogeneous external
potentials and electron-electron interactions on equal footing. We present some
general considerations concerning the probability measure of the ground state
charge density. The system shows degrees of self-similarity. By analyzing the
ground state carrier density profile, we show that although it is not Gaussian,
the critical exponents are consistent with Kondev hyper-scaling relations.
Using Schramm-Loewner (SLE) evolution we show that the ungated graphene has
conformal invariance and the random zero-charge density contours are
SLE$_{\kappa}$ with $\kappa=1.8\pm 0.2$.


title:
Demonstration of entanglement assisted invariance on IBM's Quantum
  Experience

abstract:
  Quantum entanglement is among the most fundamental, yet from classical
intuition also most surprising properties of the fully quantum nature of
physical reality. We report several experiments performed on IBM's Quantum
Experience demonstrating envariance -- entanglement assisted invariance.
Envariance is a recently discovered symmetry of composite quantum systems,
which is at the foundational origin of physics and a quantum phenomenon of pure
states. These very easily reproducible and freely accessible experiments on
Quantum Experience provide simple tools to study the properties of envariance,
and we illustrate this for several cases with "quantum universes" consisting of
up to five qubits.


title: Optimizing positional scoring rules for rank aggregation

abstract:
  Nowadays, several crowdsourcing projects exploit social choice methods for
computing an aggregate ranking of alternatives given individual rankings
provided by workers. Motivated by such systems, we consider a setting where
each worker is asked to rank a fixed (small) number of alternatives and, then,
a positional scoring rule is used to compute the aggregate ranking. Among the
apparently infinite such rules, what is the best one to use? To answer this
question, we assume that we have partial access to an underlying true ranking.
Then, the important optimization problem to be solved is to compute the
positional scoring rule whose outcome, when applied to the profile of
individual rankings, is as close as possible to the part of the underlying true
ranking we know. We study this fundamental problem from a theoretical viewpoint
and present positive and negative complexity results and, furthermore,
complement our theoretical findings with experiments on real-world and
synthetic data.


title: Effect of gene-expression bursts on stochastic timing of cellular events

abstract:
  Gene expression is inherently a noisy process which manifests as cell-to-cell
variability in time evolution of proteins. Consequently, events that trigger at
critical threshold levels of regulatory proteins exhibit stochasticity in their
timing. An important contributor to the noise in gene expression is translation
bursts which correspond to randomness in number of proteins produced in a
single mRNA lifetime. Modeling timing of an event as a first-passage time (FPT)
problem, we explore the effect of burst size distribution on event timing.
Towards this end, the probability density function of FPT is computed for a
gene expression model with burst size drawn from a generic non-negative
distribution. Analytical formulas for FPT moments are provided in terms of
known vectors and inverse of a matrix. The effect of burst size distribution is
investigated by looking at how the feedback regulation strategy that minimizes
noise in timing around a given time deviates from the case when burst is
deterministic. Interestingly, results show that the feedback strategy for
deterministic burst case is quite robust to change in burst size distribution,
and deviations from it are confined to about 20% of the optimal value. These
findings facilitate an improved understanding of noise regulation in event
timing.


title:
Bone fusion in normal and pathological development is constrained by the
  network architecture of the human skull

abstract:
  The premature fusion of cranial bones, craniosynostosis, affects the correct
development of the skull producing morphological malformations in newborns. To
assess the susceptibility of each craniofacial articulation to close
prematurely, we used a network model of the skull to quantify the link
reliability (an index based on stochastic block modeling and Bayesian
inference) of each articulation. We show that, of the 93 human skull
articulations at birth, the few articulations that are associated with
nonsyndromic craniosynostosis conditions have statistically significant lower
reliability scores than the others. In a similar way, articulations that close
during the normal postnatal development of the skull have also lower
reliability scores than those articulations that persist through adult live.
These results indicate a relationship between the architecture of the skull
network and the specific articulations that close during normal development and
in pathological conditions. Our findings suggest that the topological
arrangement of skull bones might act as an epigenetic factor, predisposing some
articulations to closure, both in normal and pathological development, and also
affecting the long-term evolution of the skull.


title: Quantum information theory of the Bell-state quantum eraser

abstract:
  Quantum systems can display particle- or wave-like properties, depending on
the type of measurement that is performed on them. The Bell-state quantum
eraser is an experiment that brings the duality to the forefront, as a single
measurement can retroactively be made to measure particle-like or wave-like
properties (or anything in between). Here we develop a unitary
information-theoretic description of this (and several related) quantum
measurement situations that sheds light on the trade-off between the quantum
and classical features of the measurement. In particular, we show that both the
coherence of the quantum state and the classical information obtained from it
can be described using quantum-information-theoretic tools only, and that those
two measures satisfy an equality on account of the chain rule for entropies.
The coherence information and the which-path information have simple
interpretations in terms of state preparation and state determination, and
suggest ways to account for the relationship between the classical and the
quantum world.


title:
Predicting human-driving behavior to help driverless vehicles drive:
  random intercept Bayesian Additive Regression Trees

abstract:
  The development of driverless vehicles has spurred the need to predict human
driving behavior to facilitate interaction between driverless and human-driven
vehicles. Predicting human driving movements can be challenging, and poor
prediction models can lead to accidents between the driverless and human-driven
vehicles. We used the vehicle speed obtained from a naturalistic driving
dataset to predict whether a human-driven vehicle would stop before executing a
left turn. In a preliminary analysis, we found that BART produced less variable
and higher AUC values compared to a variety of other state-of-the-art binary
predictor methods. However, BART assumes independent observations, but our
dataset consists of multiple observations clustered by driver. Although methods
extending BART to clustered or longitudinal data are available, they lack
readily available software and can only be applied to clustered continuous
outcomes. We extend BART to handle correlated binary observations by adding a
random intercept and used a simulation study to determine bias, root mean
squared error, 95% coverage, and average length of 95% credible interval in a
correlated data setting. We then successfully implemented our random intercept
BART model to our clustered dataset and found substantial improvements in
prediction performance compared to BART and random intercept linear logistic
regression.


title:
The Spherically Symmetric Vacuum in Covariant $F(T) = T +
  \frac{\alpha}{2}T^{2} + \mathcal{O}(T^{\gamma})$ Gravity Theory

abstract:
  Recently, a fully covariant version of the theory of $F(T)$ torsion gravity
has been introduced (arXiv:1510.08432v2 [gr-qc]). In covariant $F(T)$ gravity
the Schwarzschild solution is not a vacuum solution for $F(T)\neq T$ and
therefore determining the spherically symmetric vacuum is an important open
problem. Within the covariant framework we perturbatively solve the spherically
symmetric vacuum gravitational equations around the Schwarzschild solution for
the scenario with $F(T)=T + (\alpha/2)\, T^{2}$, representing the dominant
terms in theories governed by Lagrangians analytic in the torsion scalar. From
this we compute the perihelion shift correction to solar system planetary
orbits as well as perturbative gravitational effects near neutron stars. This
allows us to set an upper bound on the magnitude of the coupling constant,
$\alpha$, which governs deviations from General Relativity. We find the bound
on this nonlinear torsion coupling constant by specifically considering the
uncertainty in the perihelion shift of Mercury. We also analyze a bound from a
similar comparison with the periastron orbit of the binary pulsar PSR
J0045-7319 as an independent check for consistency. Setting bounds on the
dominant nonlinear coupling is important in determining if other effects in the
solar system or greater universe could be attributable to nonlinear torsion.


title: Discreet Coin Weighings and the Sorting Strategy

abstract:
  In 2007, Alexander Shapovalov posed an old twist on the classical coin
weighing problem by asking for strategies that manage to conceal the identities
of specific coins while providing general information on the number of fake
coins. In 2015, Diaco and Khovanova studied various cases of these "discreet
strategies" and introduced the revealing factor, a measure of the information
that is revealed.
  In this paper we discuss a natural coin weighing strategy which we call the
sorting strategy: divide the coins into equal piles and sort them by weight. We
study the instances when the strategy is discreet, and given an outcome of the
sorting strategy, the possible number of fake coins. We prove that in many
cases, the number of fake coins can be any value in an arithmetic progression
whose length depends linearly on the number of coins in each pile. We also show
the strategy can be discreet when the number of fake coins is any value within
an arithmetic subsequence whose length also depends linearly on the number of
coins in each pile. We arrive at these results by connecting our work to the
classic Frobenius coin problem. In addition, we calculate the revealing factor
for the sorting strategy.


title:
The Cauchy problem and BEC stability for the quantum
  Boltzmann-Condensation system for bosons at very low temperature

abstract:
  We study a quantum Boltzmann-Condensation system that describes the evolution
of the interaction between a well formed Bose-Einstein condensate and the
quasi-particles cloud. The kinetic model is valid for a dilute regime at which
the temperature of the gas is very low compared to the Bose-Einstein
condensation critical temperature. In particular, our system couples the
density of the condensate from a Gross-Pitaevskii type equation to the kinetic
equation through the dispersion relation in the kinetic model and the
corresponding transition probability rate from pre to post collision momentum
states. We rigorously show the following three properties (1) the
well-posedness of the Cauchy problem for the system in the case of a radially
symmetric initial configuration, (2) find qualitative properties of the
solution such as instantaneous creation of exponential tails and, (3) prove the
uniform condensate stability related to the initial mass ratio between
condensed particles and quasi-particles. The stability result from (3) leads to
global in time existence of the initial value problem for the quantum
Boltzmann-Condensation system.


title: The A-theoretic Farrell-Jones Conjecture for virtually solvable groups

abstract:
  We prove the A-theoretic Farrell-Jones Conjecture for virtually solvable
groups. As a corollary, we obtain that the conjecture holds for S-arithmetic
groups and lattices in almost connected Lie groups.


title:
Interaction effects on the classification of crystalline topological
  insulators and superconductors

abstract:
  We classify interacting topological insulators and superconductors with
order-two crystal symmetries (reflection and twofold rotation), focusing on the
case where interactions reduce the noninteracting classification. We find that
the free-fermion $\mathbb{Z}_2$ classifications are stable against quartic
contact interactions, whereas the $\mathbb{Z}$ classifications reduce to
$\mathbb{Z}_N$, where $N$ depends on the symmetry class and the dimension $d$.
These results are derived using a quantum nonlinear $\sigma$ model (QNLSM) that
describes the effects of the quartic interactions on the boundary modes of the
crystalline topological phases. We use Clifford algebra extensions to derive
the target spaces of these QNLSMs in a unified way. The reduction pattern of
the free-fermion classification then follows from the presence or absence of
topological terms in the QNLSMs, which is determined by the homotopy group of
the target spaces. We show that this derivation can be performed using either a
complex fermion or a real Majorana representation of the crystalline
topological phases and demonstrate that these two representations give
consistent results. To illustrate the breakdown of the noninteracting
classification we present examples of crystalline topological insulators and
superconductors in dimensions one, two, and three, whose surfaces modes are
unstable against interactions. For the three-dimensional example, we show that
the reduction pattern obtained by the QNLSM method agrees with the one inferred
from the stability analysis of the boundary modes using bosonization.


title:
The Massive Protostellar Cluster NGC6334I at 220 AU Resolution:
  Discovery of Further Multiplicity, Diversity and a Hot Multi-Core

abstract:
  We present VLA and ALMA imaging of the deeply-embedded protostellar cluster
NGC6334I from 5 cm to 1.3 mm at angular resolutions as fine as 0.17 (220 AU).
The dominant hot core MM1 is resolved into seven components at 1.3 mm,
clustered within a radius of 1000 AU. Four of the components have brightness
temperatures >200 K, radii ~300 AU, minimum luminosities ~10000 Lsun, and must
be centrally heated. We term this new phenomenon a "hot multi-core". Two of
these objects also exhibit compact free-free emission at longer wavelengths,
consistent with a hypercompact HII region (MM1B) and a jet (MM1D). The spatial
kinematics of the water maser emission centered on MM1D are consistent with it
being the origin of the high-velocity bipolar molecular outflow seen in CO. The
close proximity of MM1B and MM1D (440~AU) suggests a proto-binary or a
transient bound system. Several components of MM1 exhibit steep millimeter SEDs
indicative of either unusual dust spectral properties or time variability. In
addition to resolving MM1 and the other hot core (MM2) into multiple
components, we detect five new millimeter and two new centimeter sources. Water
masers are detected for the first time toward MM4A, confirming its membership
in the protocluster. With a 1.3 mm brightness temperature of 97 K coupled with
a lack of thermal molecular line emission, MM4A appears to be a highly
optically-thick 240 Lsun dust core, possibly tracing a transient stage of
massive protostellar evolution. The nature of the strongest water maser source
CM2 remains unclear due to its combination of non-thermal radio continuum and
lack of dust emission.


title: Eigenvalue estimates on quantum graphs

abstract:
  On a finite connected metric graph, we establish upper bounds for the
eigenvalues of the Laplacian. These bounds depend on the length, the Betti
number, and the number of pendant vertices. For trees, these estimates are
sharp. We also establish sharp upper bounds for the spectral gap of the
complete graph $K_4$. The proofs are based on estimates for eigenvalues on
graphs with Dirichlet conditions imposed at the pendant vertices.


title: Gated Neural Networks for Option Pricing: Rationality by Design

abstract:
  We propose a neural network approach to price EU call options that
significantly outperforms some existing pricing models and comes with
guarantees that its predictions are economically reasonable. To achieve this,
we introduce a class of gated neural networks that automatically learn to
divide-and-conquer the problem space for robust and accurate pricing. We then
derive instantiations of these networks that are 'rational by design' in terms
of naturally encoding a valid call option surface that enforces no arbitrage
principles. This integration of human insight within data-driven learning
provides significantly better generalisation in pricing performance due to the
encoded inductive bias in the learning, guarantees sanity in the model's
predictions, and provides econometrically useful byproduct such as risk neutral
density.


title:
A Comment on the One Step Quantum Key Distribution Based on EPR
  Entanglement

abstract:
  Recently, in Sci. Rep. \textbf{6} (2016) 28767, Li et al., have proposed a
scheme for quantum key distribution using Bell states. This comment provides a
proof that the proposed scheme of Li et al., is insecure as it involves leakage
of information. Further, it is also shown that all the error rates computed in
the Li et al.'s paper are incorrect as the authors failed to recognize the fact
that any eavesdropping effort will lead to entanglement swapping. Finally, it
is established that Li et al.'s scheme can be viewed as an incrementally (but
incorrectly)modified version of the existing schemes based on Goldenberg
Vaidman (GV) subroutine.


title: Scaling in global tidal dissipation of the Earth-Moon system

abstract:
  The Moon migrated to $r_{\leftmoon}\simeq3.8\times10^{10}$ cm over a
characteristic time $r/v=10^{10}$ Gyr by tidal interaction with the Earth's
oceans at a present velocity of $v=3.8$ cm yr$^{-1}$. We derive scaling of
global dissipation that covers the entire history over the past 4.52 Gyr.
Off-resonance tidal interactions at relatively short tidal periods in the past
reveal the need for scaling {with amplitude}. The global properties of the
complex spatio-temporal dynamics and dissipation in broad spectrum ocean waves
is modeled by damping $\epsilon = h F/(2Q_0)$, where $h$ is the tidal wave
amplitude, $F$ is the tidal frequency, and $Q_0$ is the $Q$-factor at the
present time. It satisfies $Q_0\simeq 14$ for consistency of migration time and
age of the Moon consistent with observations for a near-resonance state today.
It shows a startingly fast eviction of the Moon from an unstable
near-synchronous orbit close to the Roche limit, probably in a protolunar disk.
Rapid spin down of the Earth from an intial $\sim30\%$ of break-up by the Moon
favored early formation of a clement global climate. Our theory suggests moons
may be similarly advantageous to potentially habitable exoplanets.


title: Conditionally Bi-Free Independence for Pairs of Algebras

abstract:
  In this paper, the notion of conditionally bi-free independence for pairs of
algebras is introduced. The notion of conditional $(\ell, r)$-cumulants are
introduced and it is demonstrated that conditionally bi-free independence is
equivalent to mixed cumulants. Furthermore, limit theorems for the additive
conditionally bi-free convolution are studied using both combinatorial and
analytic techniques. In particular, a conditionally bi-free partial
$\mathcal{R}$-transform is constructed and a conditionally bi-free analogue of
the L\'{e}vy-Hin\v{c}in formula for planar Borel probability measures is
derived.


title: Asymptotic tensor rank of graph tensors: beyond matrix multiplication

abstract:
  We present an upper bound on the exponent of the asymptotic behaviour of the
tensor rank of a family of tensors defined by the complete graph on $k$
vertices. For $k\geq4$, we show that the exponent per edge is at most 0.77,
outperforming the best known upper bound on the exponent per edge for matrix
multiplication ($k=3$), which is approximately 0.79. We raise the question
whether for some $k$ the exponent per edge can be below $2/3$, i.e. can
outperform matrix multiplication even if the matrix multiplication exponent
equals 2. In order to obtain our results, we generalise to higher order tensors
a result by Strassen on the asymptotic subrank of tight tensors and a result by
Coppersmith and Winograd on the asymptotic rank of matrix multiplication. Our
results have applications in entanglement theory and communication complexity.


title: Light-like Scattering in Quantum Gravity

abstract:
  We consider scattering in quantum gravity and derive long-range classical and
quantum contributions to the scattering of light-like bosons and fermions
(spin-0, spin-1/2, spin-1) from an external massive scalar field, such as the
Sun or a black hole. This is achieved by treating general relativity as an
effective field theory and identifying the non-analytic pieces of the one-loop
gravitational scattering amplitude. It is emphasized throughout the paper how
modern amplitude techniques, involving spinor-helicity variables, unitarity,
and squaring relations in gravity enable much simplified computations. We
directly verify, as predicted by general relativity, that all classical effects
in our computation are universal (in the context of matter type and
statistics). Using an eikonal procedure we confirm the post-Newtonian general
relativity correction for light-like bending around large stellar objects. We
also comment on treating effects from quantum hbar dependent terms using the
same eikonal method.


title: Screening Rules for Convex Problems

abstract:
  We propose a new framework for deriving screening rules for convex
optimization problems. Our approach covers a large class of constrained and
penalized optimization formulations, and works in two steps. First, given any
approximate point, the structure of the objective function and the duality gap
is used to gather information on the optimal solution. In the second step, this
information is used to produce screening rules, i.e. safely identifying
unimportant weight variables of the optimal solution. Our general framework
leads to a large variety of useful existing as well as new screening rules for
many applications. For example, we provide new screening rules for general
simplex and $L_1$-constrained problems, Elastic Net, squared-loss Support
Vector Machines, minimum enclosing ball, as well as structured norm regularized
problems, such as group lasso.


title: Incorporating Relation Paths in Neural Relation Extraction

abstract:
  Distantly supervised relation extraction has been widely used to find novel
relational facts from plain text. To predict the relation between a pair of two
target entities, existing methods solely rely on those direct sentences
containing both entities. In fact, there are also many sentences containing
only one of the target entities, which provide rich and useful information for
relation extraction. To address this issue, we build inference chains between
two target entities via intermediate entities, and propose a path-based neural
relation extraction model to encode the relational semantics from both direct
sentences and inference chains. Experimental results on real-world datasets
show that, our model can make full use of those sentences containing only one
target entity, and achieves significant and consistent improvements on relation
extraction as compared with baselines. The source code of this paper can be
obtained from https: //github.com/thunlp/PathNRE.


title: Predictive modelling of football injuries

abstract:
  The goal of this thesis is to investigate the potential of predictive
modelling for football injuries. This work was conducted in close collaboration
with Tottenham Hotspurs FC (THFC), the PGA European tour and the participation
of Wolverhampton Wanderers (WW).
  Three investigations were conducted:
  1. Predicting the recovery time of football injuries using the UEFA injury
recordings: The UEFA recordings is a common standard for recording injuries in
professional football. For this investigation, three datasets of UEFA injury
recordings were available. Different machine learning algorithms were used in
order to build a predictive model. The performance of the machine learning
models is then improved by using feature selection conducted through
correlation-based subset feature selection and random forests.
  2. Predicting injuries in professional football using exposure records: The
relationship between exposure (in training hours and match hours) in
professional football athletes and injury incidence was studied. A common
problem in football is understanding how the training schedule of an athlete
can affect the chance of him getting injured. The task was to predict the
number of days a player can train before he gets injured.
  3. Predicting intrinsic injury incidence using in-training GPS measurements:
A significant percentage of football injuries can be attributed to overtraining
and fatigue. GPS data collected during training sessions might provide
indicators of fatigue, or might be used to detect very intense training
sessions which can lead to overtraining. This research used GPS data gathered
during training sessions of the first team of THFC, in order to predict whether
an injury would take place during a week.


title:
Differential equations involving cubic theta functions and Eisenstein
  series

abstract:
  In this paper, we derive systems of ordinary differential equations (ODEs)
satisfied by modular forms of level three, which are level three versions of
Ramanujan's system of ODEs satisfied by the classical Eisenstein series.


title: Force-Depending Radiation Reaction study in an undulator device

abstract:
  The effect of force-depending radiation reaction on charge motion traveling
inside an undulator is studied using the new force approach for radiation
reaction. The effect on the dynamics of a charged particle is determined with
the hope that this one can be measured experimentally and can be determined
whether or not this approach points on the right direction to understand the
nature of radiation reaction.


title: New Angles on Energy Correlation Functions

abstract:
  Jet substructure observables, designed to identify specific features within
jets, play an essential role at the Large Hadron Collider (LHC), both for
searching for signals beyond the Standard Model and for testing QCD in extreme
phase space regions. In this paper, we systematically study the structure of
infrared and collinear safe substructure observables, defining a generalization
of the energy correlation functions to probe $n$-particle correlations within a
jet. These generalized correlators provide a flexible basis for constructing
new substructure observables optimized for specific purposes. Focusing on three
major targets of the jet substructure community---boosted top tagging, boosted
$W/Z/H$ tagging, and quark/gluon discrimination---we use power-counting
techniques to identify three new series of powerful discriminants: $M_i$,
$N_i$, and $U_i$. The $M_i$ series is designed for use on groomed jets,
providing a novel example of observables with improved discrimination power
after the removal of soft radiation. The $N_i$ series behave parametrically
like the $N$-subjettiness ratio observables, but are defined without respect to
subjet axes, exhibiting improved behavior in the unresolved limit. Finally, the
$U_i$ series improves quark/gluon discrimination by using higher-point
correlators to simultaneously probe multiple emissions within a jet. Taken
together, these observables broaden the scope for jet substructure studies at
the LHC.


title:
Swift observations of unidentified radio sources in the revised Third
  Cambridge Catalogue

abstract:
  We have investigated a group of unassociated radio sources included in the
3CR cat- alogue to increase the multi-frequency information on them and
possibly obtain an identification. We have carried out an observational
campaign with the Swift satellite to observe with the UVOT and the XRT
telescopes the field of view of 21 bright NVSS sources within the positional
uncertainty region of the 3CR sources. Furthermore, we have searched in the
recent AllWISE Source Catalogue for infrared sources matching the position of
these NVSS sources. We have detected significant emission in the soft X-ray
band for nine of the investigated NVSS sources. To all of them, and in four
cases with no soft X-ray association, we have associated a WISE infrared
counterpart. Eight of these infrared candidates have not been proposed earlier
in the literature. In the five remaining cases our candidate matches one among
a few optical candidates suggested for the same 3CR source in previous studies.
No source has been detected in the UVOT filters at the position of the NVSS
objects, confirming the scenario that all of them are heavily obscured. With
this in mind, a spectroscopic campaign, preferably in the infrared band, will
be necessary to establish the nature of the sources that we have finally
identified.


title:
A cold neutron star in the transient low-mass X-ray binary HETE
  J1900.1-2455 after 10 years of active accretion

abstract:
  The neutron star low-mass X-ray binary and intermittent millisecond X-ray
pulsar HETE J1900.1-2455 returned to quiescence in late 2015, after a prolonged
accretion outburst of ~10 yr. Using a Chandra observation taken ~180 d into
quiescence we detect the source at a luminosity of ~4.5E31 (D/4.7 kpc)^2 erg/s
(0.5-10 keV). The X-ray spectrum can be described by a neutron star atmosphere
model with a temperature of ~54 eV for an observer at infinity. We perform
thermal evolution calculations based on the 2016 quiescent data and a <98 eV
temperature upper limit inferred from a Swift observation taken during an
unusually brief (<2 weeks) quiescent episode in 2007. We find no evidence in
the present data that the thermal properties of the crust, such as the heating
rate and thermal conductivity, are different than those of non-pulsating
neutron stars. Finding this neutron star so cold after its long outburst
imposes interesting constraints on the heat capacity of the stellar core; these
become even stronger if further cooling were to occur.


title: Hexagonal structure of phase III of solid hydrogen

abstract:
  A hexagonal structure of solid molecular hydrogen with $P6_122$ symmetry is
calculated to be more stable below about 200 GPa than the monoclinic $C2/c$
structure identified previously as the best candidate for phase III. We find
that the effects of nuclear quantum and thermal vibrations play a central role
in the stabilization of $P6_122$. The $P6_122$ and $C2/c$ structures are very
similar and their Raman and infra-red data are in good agreement with
experiment. However, our calculations show that the hexagonal $P6_122$
structure provides better agreement with the available x-ray diffraction data
than the $C2/c$ structure at pressures below about 200 GPa. We suggest that two
phase-III-like structures may be formed at high pressures, hexagonal $P6_122$
below about 200 GPa and monoclinic $C2/c$ at higher pressures.


title: Giant star seismology

abstract:
  The internal properties of stars in the red-giant phase undergo significant
changes on relatively short timescales. Long near-uninterrupted high-precision
photometric timeseries observations from dedicated space missions such as CoRoT
and Kepler have provided seismic inferences of the global and internal
properties of a large number of evolved stars, including red giants. These
inferences are confronted with predictions from theoretical models to improve
our understanding of stellar structure and evolution. Our knowledge and
understanding of red giants have indeed increased tremendously using these
seismic inferences, and we anticipate that more information is still hidden in
the data. Unraveling this will further improve our understanding of stellar
evolution. This will also have significant impact on our knowledge of the Milky
Way Galaxy as well as on exo-planet host stars. The latter is important for our
understanding of the formation and structure of planetary systems.


title:
Application of a resource theory for magic states to fault-tolerant
  quantum computing

abstract:
  Motivated by their necessity for most fault-tolerant quantum computation
schemes, we formulate a resource theory for magic states. We first show that
robustness of magic is a well-behaved magic monotone that operationally
quantifies the classical simulation overhead for a Gottesman-Knill type scheme
using ancillary magic states. Our framework subsequently finds immediate
application in the task of synthesizing non-Clifford gates using magic states.
When magic states are interspersed with Clifford gates, Pauli measurements and
stabilizer ancillas - the most general synthesis scenario - then the class of
synthesizable unitaries is hard to characterize. Our techniques can place
non-trivial lower bounds on the number of magic states required for
implementing a given target unitary. Guided by these results we have found new
and optimal examples of such synthesis.


title: The Complex Circumstellar and Circumbinary Environment of V356 Sgr

abstract:
  We analyze 45 spectropolarimetric observations of the eclipsing, interacting
binary star V356 Sgr, obtained over a period of 21 years, to characterize the
geometry of the system's circumstellar material. After removing interstellar
polarization from these data, we find the system exhibits a large intrinsic
polarization signature arising from electron scattering. In addition, the lack
of repeatable eclipses in the polarization phase curves indicates the presence
of a substantial pool of scatterers not occulted by either star. We suggest
that these scatterers form either a circumbinary disk coplanar with the
gainer's accretion disk or an elongated structure perpendicular to the orbital
plane of V356 Sgr, possibly formed by bipolar outflows. We also observe
small-scale, cycle-to-cycle variations in the magnitude of intrinsic
polarization at individual phases, which we interpret as evidence of
variability in the amount of scattering material present within and around the
system. This may indicate a mass transfer or mass loss rate that varies on the
time-scale of the system's orbital period. Finally, we compare the basic
polarimetric properties of V356 Sgr with those of the well studied beta Lyr
system; the significant differences observed between the two systems suggests
diversity in the basic circumstellar geometry of Roche-lobe overflow systems


title: Monojet searches for momentum-dependent dark matter interactions

abstract:
  We consider minimal dark matter scenarios featuring momentum-dependent
couplings of the dark sector to the Standard Model. We derive constraints from
existing LHC searches in the monojet channel, estimate the future LHC
sensitivity for an integrated luminosity of 300 fb$^{-1}$, and compare with
models exhibiting conventional momentum-independent interactions with the dark
sector. In addition to being well motivated by (composite) pseudo-Goldstone
dark matter scenarios, momentum-dependent couplings are interesting as they
weaken direct detection constraints. For a specific dark matter mass, the LHC
turns out to be sensitive to smaller signal cross-sections in the
momentum-dependent case, by virtue of the harder jet transverse-momentum
distribution.


title:
Testing a Dynamical Equilibrium Model of the Extraplanar Diffuse Ionized
  Gas in NGC 891

abstract:
  The observed scale heights of extraplanar diffuse ionized gas (eDIG) layers
exceed their thermal scale heights by a factor of a few in the Milky Way and
other nearby edge-on disk galaxies. Here, we test a dynamical equilibrium model
of the extraplanar diffuse ionized gas layer in NGC 891, where we ask whether
the thermal, turbulent, magnetic field, and cosmic ray pressure gradients are
sufficient to support the layer. In optical emission line spectroscopy from the
SparsePak integral field unit on the WIYN 3.5-meter telescope, the H-alpha
emission in position-velocity space suggests that the eDIG is found in a ring
between galactocentric radii of R_min <= R <= 8 kpc, where R_min >= 2 kpc. We
find that the thermal (sigma_th = 11 km/s) and turbulent (sigma_turb = 25 km/s)
velocity dispersions are insufficient to satisfy the hydrostatic equilibrium
equation given an exponential electron scale height of h_z = 1.0 kpc. Using a
literature analysis of radio continuum observations from the CHANG-ES survey,
we demonstrate that the magnetic field and cosmic ray pressure gradients are
sufficient to stably support the gas at R >= 8 kpc if the cosmic rays are
sufficiently coupled to the system (gamma_cr = 1.45). Thus, a stable dynamical
equilibrium model is viable only if the extraplanar diffuse ionized gas is
found in a thin ring around R = 8 kpc, and non-equilibrium models such as a
galactic fountain flow are of interest for further study.


title:
On Lithium-Rich Red Giants. II. Engulfment on the Giant Branch of
  Trumpler 20

abstract:
  The Gaia-ESO survey recently reported on a large sample of lithium (Li)
abundance determinations for evolved stars in the rich open cluster Trumpler
20. They argue for a scenario where virtually all stars experience post main
sequence mixing and Li is preserved in only two objects. We present an
alternate explanation, where Li is normal in the vast majority of cluster stars
and anomalously high in these two cases. We demonstrate that the Li upper
limits in the red giants can be explained with a combination of main sequence
depletion and standard dredge-up, and that they are close to the detected
levels in other systems of similar age. In our framework, the two detected
giants are anomalously Li-rich, and we propose that both could have been
produced by the engulfment of a substellar mass companion of 16(+6-10) M_J.
This would imply that ~5% of 1.8 solar mass stars in this system, and by
extension elsewhere, should have substellar mass companions of high mass that
could be engulfed at some point in their lifetimes. We discuss future tests
that could confirm or refute this scenario.


title: Multi-center Vector Field Methods for Wave Equations

abstract:
  We develop the method of vector-fields to further study Dispersive Wave
Equations.
  Radial vector fields are used to get a-priori estimates such as the Morawetz
estimate on solutions of Dispersive Wave Equations.
  A key to such estimates is the repulsiveness or nontrapping conditions on the
flow corresponding to the wave equation. Thus this method is limited to
potential perturbations which are repulsive, that is the radial derivative
pointing away from the origin. In this work, we generalize this method to
include potentials which are repulsive relative to a line in space (in three or
higher dimensions), among other cases. This method is based on constructing
multi-centered vector fields as multipliers, cancellation lemmas and energy
localization.


title: Balancing Covariates via Propensity Score Weighting

abstract:
  Covariate balance is crucial for unconfounded descriptive or causal
comparisons. However, lack of balance is common in observational studies. This
article considers weighting strategies for balancing covariates. We define a
general class of weights---the balancing weights---that balance the weighted
distributions of the covariates between treatment groups. These weights
incorporate the propensity score to weight each group to an analyst-selected
target population. This class unifies existing weighting methods, including
commonly used weights such as inverse-probability weights as special cases.
General large-sample results on nonparametric estimation based on these weights
are derived. We further propose a new weighting scheme, the overlap weights, in
which each unit's weight is proportional to the probability of that unit being
assigned to the opposite group. The overlap weights are bounded, and minimize
the asymptotic variance of the weighted average treatment effect among the
class of balancing weights. The overlap weights also possess a desirable
small-sample exact balance property, based on which we propose a new method
that achieves exact balance for means of any selected set of covariates. Two
applications illustrate these methods and compare them with other approaches.


title:
A Rotation Invariant Latent Factor Model for Moveme Discovery from
  Static Poses

abstract:
  We tackle the problem of learning a rotation invariant latent factor model
when the training data is comprised of lower-dimensional projections of the
original feature space. The main goal is the discovery of a set of 3-D bases
poses that can characterize the manifold of primitive human motions, or
movemes, from a training set of 2-D projected poses obtained from still images
taken at various camera angles. The proposed technique for basis discovery is
data-driven rather than hand-designed. The learned representation is rotation
invariant, and can reconstruct any training instance from multiple viewing
angles. We apply our method to modeling human poses in sports (via the Leeds
Sports Dataset), and demonstrate the effectiveness of the learned bases in a
range of applications such as activity classification, inference of dynamics
from a single frame, and synthetic representation of movements.


title: Dynamical maps, quantum detailed balance and Petz recovery map

abstract:
  Markovian master equations (formally known as quantum dynamical semigroups)
can be used to describe the evolution of a quantum state $\rho$ when in contact
with a memoryless thermal bath. This approach has had much success in
describing the dynamics of real-life open quantum systems in the lab. Such
dynamics increase the entropy of the state $\rho$ and the bath until both
systems reach thermal equilibrium, at which point entropy production stops. Our
main result is to show that the entropy production at time $t$ is bounded by
the relative entropy between the original state and the state at time $2t$. The
bound puts strong constraints on how quickly a state can thermalise, and we
prove that the factor of $2$ is tight. The proof makes use of a key physically
relevant property of these dynamical semigroups -- detailed balance, showing
that this property is intimately connected with the field of recovery maps from
quantum information theory. We envisage that the connections made here between
the two fields will have further applications. We also use this connection to
show that a similar relation can be derived when the fixed point is not
thermal.


title: Overhead analysis of universal concatenated quantum codes

abstract:
  We analyze the resource overhead of recently proposed methods for universal
fault-tolerant quantum computation using concatenated codes. Namely, we examine
the concatenation of the 7-qubit Steane code with the 15-qubit Reed-Muller
code, which allows for the construction of the 49 and 105-qubit codes that do
not require the need for magic state distillation for universality. We compute
a lower bound for the adversarial noise threshold of the 105-qubit code and
find it to be $8.33\times 10^{-6}.$ We obtain a depolarizing noise threshold
for the 49-qubit code of $9.69\times 10^{-4}$ which is competitive with the
105-qubit threshold result of $1.28\times 10^{-3}$. We then provide lower
bounds on the resource requirements of the 49 and 105-qubit codes and compare
them with the surface code implementation of a logical $T$ gate using magic
state distillation. For the sampled input error rates and noise model, we find
that the surface code achieves a smaller overhead compared to our concatenated
schemes.