title: Implementing High-Order FIR Filters in FPGAs

abstract:
  Contemporary field-programmable gate arrays (FPGAs) are predestined for the
application of finite impulse response (FIR) filters. Their embedded digital
signal processing (DSP) blocks for multiply-accumulate operations enable
efficient fixed-point computations, in cases where the filter structure is
accurately mapped to the dedicated hardware architecture. This brief presents a
generic systolic structure for high-order FIR filters, efficiently exploiting
the hardware resources of an FPGA in terms of routability and timing. Although
this seems to be an easily implementable task, the synthesizing tools require
an adaptation of the straightforward digital filter implementation for an
optimal mapping. Using the example of a symmetric FIR filter with 90 taps, we
demonstrate the performance of the proposed structure with FPGAs from Xilinx
and Altera. The implementation utilizes less than 1% of slice logic and runs at
clock frequencies up to 526 MHz. Moreover, an enhancement of the structure
ultimately provides an extended dynamic range for the quantized coefficients
without the costs of additional slice logic.


title: Equations of state for supernovae and compact stars

abstract:
  We review various theoretical approaches for the equation of state (EoS) of
dense matter, relevant for the description of core-collapse supernovae, compact
stars and compact star mergers. The emphasis is put on models that are
applicable to all of these scenarios. Such EoS models have to cover large
ranges in baryon number density, temperature and isospin asymmetry. The
characteristics of matter change dramatically within these ranges, from a
mixture of nucleons, nuclei, and electrons to uniform, strongly interacting
matter containing nucleons, and possibly other particles such as hyperons or
quarks. As the development of an EoS requires joint efforts from many
directions we consider different theoretical approaches and discuss relevant
experimental and observational constraints which provide insights for future
research. Finally, results from applications of the discussed EoS models are
summarized.


title: Modulation Classification via Subspace Detection in MIMO Systems

abstract:
  The problem of efficient modulation classification (MC) in multiple-input
multiple-output (MIMO) systems is considered. Per-layer likelihood-based MC is
proposed by employing subspace decomposition to partially decouple the
transmitted streams. When detecting the modulation type of the stream of
interest, a dense constellation is assumed on all remaining streams. The
proposed classifier outperforms existing MC schemes at a lower complexity cost,
and can be efficiently implemented in the context of joint MC and subspace data
detection.


title:
Notes on the computation of periodic orbits using Newton and Melnikov's
  method

abstract:
  These notes were written during the 9th and 10th sessions of the subject
Dynamical Systems II coursed at DTU (Denmark) during the Winter Semester
2015-2016, and later extended in February 2017. They aim to provide students
with a theoretical and numerical background for the computation of periodic
orbits using Newton's method. We focus on periodically perturbed
quasi-integrable systems (using the forced pendulum as an example) and hence we
take advantage of the Melnikov method to get first guesses. However, these well
known techniques are general enough to be applied in other type of systems.
Periodic orbits are computed by solving a fixed-point equation for the
stroboscopic map, which is very fast and precise. We also consider computing
the Poincar\'e map and compare both strategies. In both cases we show how to
compute the Jacobian of the maps, which is necessary for the Newton method, by
means of variational equations and the implicit function theorem. Some
exercises are proposed along the notes, whose solutions can be found in
github.com/a-granados. The notes themselves do not contain any reference,
although everything described here is well known in the Dynamical Systems
community. A typical reference for the Melnikov method for subharmonic orbits
is the book [GucHol83]. More about the variational equations and their
numerical applications can be found in the notes [Sim].


title: The Rado Path Decomposition Theorem

abstract:
  We discuss a theorem of Rado: Every r-coloring of the pairs of natural
numbers has a path decomposition.


title: Pulsar Magnetospheres and Pulsar Winds

abstract:
  Surprisingly, the chronology of nearly 50 years of the pulsar magnetosphere
and pulsar wind research is quite similar to the history of our civilization.
Using this analogy, I have tried to outline the main results obtained in this
field. In addition to my talk, the possibility of particle acceleration due to
different processes in the pulsar magnetosphere is discussed in more detail.


title: The K\"ahler-Ricci flow on Fano bundles

abstract:
  We study the behavior of the K\"ahler-Ricci flow on some Fano bundle which is
a trivial bundle on one Zariski open set. We show that if the fiber is
$\mathbb{P}^{m}$ blown up at one point or some weighted projective space blown
up at the orbifold point and the initial metric is in a suitable k\"ahler
class, then the fibers collapse in finite time and the metrics converge
sub-sequentially in Gromov-Hausdorff sense to a metric on the base.


title:
Thermal Equilibrium in D-dimensions: From Fluids and Polymers to Kinetic
  Wealth Exchange Models

abstract:
  In this paper we discuss some examples of systems composed of $N$ units,
which exchange a conserved quantity $x$ according to some given stochastic
rule, from some standard kinetic model of condensed matter physics to the
kinetic exchange models used for studying the wealth dynamics of social
systems. The focus is on the similarity of the equilibrium state of the various
examples considered, which all relax toward a canonical Gibbs-Boltzmann
equilibrium distribution for the quantity $x$, given by a $\Gamma$-distribution
with shape parameter $\alpha = D/2$, which implicitly defines an effective
dimension $D$ of the system. We study various systems exploring (continuous)
values of $D$ in the interval $[1,\infty)$.


title: DOTmark - A Benchmark for Discrete Optimal Transport

abstract:
  The Wasserstein metric or earth mover's distance (EMD) is a useful tool in
statistics, machine learning and computer science with many applications to
biological or medical imaging, among others. Especially in the light of
increasingly complex data, the computation of these distances via optimal
transport is often the limiting factor. Inspired by this challenge, a variety
of new approaches to optimal transport has been proposed in recent years and
along with these new methods comes the need for a meaningful comparison.
  In this paper, we introduce a benchmark for discrete optimal transport,
called DOTmark, which is designed to serve as a neutral collection of problems,
where discrete optimal transport methods can be tested, compared to one
another, and brought to their limits on large-scale instances. It consists of a
variety of grayscale images, in various resolutions and classes, such as
several types of randomly generated images, classical test images and real data
from microscopy.
  Along with the DOTmark we present a survey and a performance test for a cross
section of established methods ranging from more traditional algorithms, such
as the transportation simplex, to recently developed approaches, such as the
shielding neighborhood method, and including also a comparison with commercial
solvers.


title: On the General Analytical Solution of the Kinematic Cosserat Equations

abstract:
  Based on a Lie symmetry analysis, we construct a closed form solution to the
kinematic part of the (partial differential) Cosserat equations describing the
mechanical behavior of elastic rods. The solution depends on two arbitrary
analytical vector functions and is analytical everywhere except a certain
domain of the independent variables in which one of the arbitrary vector
functions satisfies a simple explicitly given algebraic relation. As our main
theoretical result, in addition to the construction of the solution, we proof
its generality. Based on this observation, a hybrid semi-analytical solver for
highly viscous two-way coupled fluid-rod problems is developed which allows for
the interactive high-fidelity simulations of flagellated microswimmers as a
result of a substantial reduction of the numerical stiffness.


title:
Optimal Attack Strategies Subject to Detection Constraints Against
  Cyber-Physical Systems

abstract:
  This paper studies an attacker against a cyber-physical system (CPS) whose
goal is to move the state of a CPS to a target state while ensuring that his or
her probability of being detected does not exceed a given bound. The attacker's
probability of being detected is related to the nonnegative bias induced by his
or her attack on the CPS' detection statistic. We formulate a linear quadratic
cost function that captures the attacker's control goal and establish
constraints on the induced bias that reflect the attacker's detection-avoidance
objectives. When the attacker is constrained to be detected at the false-alarm
rate of the detector, we show that the optimal attack strategy reduces to a
linear feedback of the attacker's state estimate. In the case that the
attacker's bias is upper bounded by a positive constant, we provide two
algorithms -- an optimal algorithm and a sub-optimal, less computationally
intensive algorithm -- to find suitable attack sequences. Finally, we
illustrate our attack strategies in numerical examples based on a
remotely-controlled helicopter under attack.


title: Power law cosmology model comparison with CMB scale information

abstract:
  Despite the ability of the cosmological concordance model ($\Lambda$CDM) to
describe the cosmological observations exceedingly well, power law expansion of
the Universe scale radius, $R(t)\propto t^n$, has been proposed as an
alternative framework. We examine here these models, analyzing their ability to
fit cosmological data using robust model comparison criteria. Type Ia
supernovae (SNIa), baryonic acoustic oscillations (BAO) and acoustic scale
information from the cosmic microwave background (CMB) have been used. We find
that SNIa data either alone or combined with BAO can be well reproduced by both
$\Lambda$CDM and power law expansion models with $n\sim 1.5$, while the
constant expansion rate model $(n=1)$ is clearly disfavored. Allowing for some
redshift evolution in the SNIa luminosity essentially removes any clear
preference for a specific model. The CMB data are well known to provide the
most stringent constraints on standard cosmological models, in particular,
through the position of the first peak of the temperature angular power
spectrum, corresponding to the sound horizon at recombination, a scale
physically related to the BAO scale. Models with $n\geq 1$ lead to a divergence
of the sound horizon and do not naturally provide the relevant scales for the
BAO and the CMB. We retain an empirical footing to overcome this issue: we let
the data choose the preferred values for these scales, while we recompute the
ionization history in power law models, to obtain the distance to the CMB. In
doing so, we find that the scale coming from the BAO data is not consistent
with the observed position of the first peak of the CMB temperature angular
power spectrum for any power law cosmology. Therefore, we conclude that when
the three standard probes are combined, the $\Lambda$CDM model is very strongly
favored over any of these alternative models, which are then essentially ruled
out.


title:
Measuring Masses in Semi-Invisible Final States at Electron-Positron
  Colliders

abstract:
  Mass measurement of a particle whose decay products including invisible
particles is a challenging task at colliders. For a new physics model involving
a dark matter candidate $N$ and a $Z_2$ symmetry that stabilizes it, a typical
new process at $e^+e^-$ colliders is the pair production $e^+e^- \to Y\bar{Y}$
followed by decay processes $Y\to aN$ and $\bar{Y}\to b\bar{N}$, where $a$ and
$b$ are visible but $N$ is invisible. In this work, we propose a new method to
measure the physical masses in this topology by making use of the kinematic
equations given by momentum-energy conservation and on-shell conditions. For
each event, the solvability of these equations determines a limited region on
the trial $m_Y$-$m_N$ plane. The edge of this region can be used to define two
variables, $m_Y^\mathrm{edge}$ and $m_N^\mathrm{edge}$, whose distributions are
utilized to derive the measurement values of $m_Y$ and $m_N$. The measurement
deviations and uncertainties are also estimated after including detector
effects and background contamination.


title:
Differential Inequalities in Multi-Agent Coordination and Opinion
  Dynamics Modeling

abstract:
  Distributed algorithms of multi-agent coordination have attracted substantial
attention from the research community; the simplest and most thoroughly studied
of them are consensus protocols in the form of differential or difference
equations over general time-varying weighted graphs. These graphs are usually
characterized algebraically by their associated Laplacian matrices. Network
algorithms with similar algebraic graph theoretic structures, called being of
Laplacian-type in this paper, also arise in other related multi-agent control
problems, such as aggregation and containment control, target surrounding,
distributed optimization and modeling of opinion evolution in social groups. In
spite of their similarities, each of such algorithms has often been studied
using separate mathematical techniques. In this paper, a novel approach is
offered, allowing a unified and elegant way to examine many Laplacian-type
algorithms for multi-agent coordination. This approach is based on the analysis
of some differential or difference inequalities that have to be satisfied by
the some "outputs" of the agents (e.g. the distances to the desired set in
aggregation problems). Although such inequalities may have many unbounded
solutions, under natural graphic connectivity conditions all their bounded
solutions converge (and even reach consensus), entailing the convergence of the
corresponding distributed algorithms. In the theory of differential equations
the absence of bounded non-convergent solutions is referred to as the
equation's dichotomy. In this paper, we establish the dichotomy criteria of
Laplacian-type differential and difference inequalities and show that these
criteria enable one to extend a number of recent results, concerned with
Laplacian-type algorithms for multi-agent coordination and modeling opinion
formation in social groups.


title: Dark Matter in a Constrained $E_6$ Inspired SUSY Model

abstract:
  We investigate dark matter in a constrained $E_6$ inspired supersymmetric
model with an exact custodial symmetry and compare with the CMSSM. The
breakdown of $E_6$ leads to an additional $U(1)_N$ symmetry and a discrete
matter parity. The custodial and matter symmetries imply there are two stable
dark matter candidates, though one may be extremely light and contribute
negligibly to the relic density. We demonstrate that a predominantly Higgsino,
or mixed bino-Higgsino, neutralino can account for all of the relic abundance
of dark matter, while fitting a 125 GeV SM-like Higgs and evading LHC limits on
new states. However we show that the recent LUX 2016 limit on direct detection
places severe constraints on the mixed bino-Higgsino scenarios that explain all
of the dark matter. Nonetheless we still reveal interesting scenarios where the
gluino, neutralino and chargino are light and discoverable at the LHC, but the
full relic abundance is not accounted for. At the same time we also show that
there is a huge volume of parameter space, with a predominantly Higgsino dark
matter candidate that explains all the relic abundance, that will be
discoverable with XENON1T. Finally we demonstrate that for the $E_6$ inspired
model the exotic leptoquarks could still be light and within range of future
LHC searches.


title:
Unidimensional factor models imply weaker partial correlations than
  zero-order correlations

abstract:
  In a unidimensional factor model it is assumed that the set of indicators
that loads on this factor are conditionally independent given the latent
factor. Two indicators are, however, never conditionally independent given (a
set of) other indicators that load on this factor, as this would require one of
the indicators that is conditioned on to correlate one with the latent factor.
Although partial correlations between two indicators given the other indicators
can thus never equal zero (Holland and Rosenbaum, 1986), we show in this paper
that the partial correlations do need to be always weaker than the zero-order
correlations. More precisely, we prove that the partial correlation between two
observed variables that load on one factor given all other observed variables
that load on this factor, is always closer to zero than the zero-order
correlation between these two variables.


title: Cubulating random groups in the square model

abstract:
  Our main result is that for densities $<\frac{3}{10}$ a random group in the
square model has the Haagerup property and is residually finite. Moreover, we
generalize the Isoperimetric Inequality, to some class of non-planar diagrams
and, using this, we introduce a system of modified hypergraphs providing the
structure of a space with walls on the Cayley complex of a random group. Then
we show that the natural action of a random group on this space with walls is
proper, which gives the proper action of a random group on a CAT(0) cube
complex.


title:
A system of state-dependent delay differential equation modelling forest
  growth II: boundedness of solutions

abstract:
  In this article we consider a class of state-dependent delay differential
equations which is modelling the dynamics of the number of adult trees in
forests. We prove the boundedness of solutions for a single species model as
well as a two-species model.


title: Machine learning applied to single-shot x-ray diagnostics in an XFEL

abstract:
  X-ray free-electron lasers (XFELs) are the only sources currently able to
produce bright few-fs pulses with tunable photon energies from 100 eV to more
than 10 keV. Due to the stochastic SASE operating principles and other
technical issues the output pulses are subject to large fluctuations, making it
necessary to characterize the x-ray pulses on every shot for data sorting
purposes. We present a technique that applies machine learning tools to predict
x-ray pulse properties using simple electron beam and x-ray parameters as
input. Using this technique at the Linac Coherent Light Source (LCLS), we
report mean errors below 0.3 eV for the prediction of the photon energy at 530
eV and below 1.6 fs for the prediction of the delay between two x-ray pulses.
We also demonstrate spectral shape prediction with a mean agreement of 97%.
This approach could potentially be used at the next generation of
high-repetition-rate XFELs to provide accurate knowledge of complex x-ray
pulses at the full repetition rate.


title:
Sobolev type inequalities, Euler-Hilbert-Sobolev and
  Sobolev-Lorentz-Zygmund spaces on homogeneous groups

abstract:
  We define Euler-Hilbert-Sobolev spaces and obtain embedding results on
homogeneous groups using Euler operators, which are homogeneous differential
operators of order zero. Sharp remainder terms of $L^{p}$ and weighted Sobolev
type and Sobolev-Rellich inequalities on homogeneous groups are given. Most
inequalities are obtained with best constants. As consequences, we obtain
analogues of the generalised classical Sobolev type and Sobolev-Rellich
inequalities. We also discuss applications of logarithmic Hardy inequalities to
Sobolev-Lorentz-Zygmund spaces. The obtained results are new already in the
anisotropic $\mathbb R^{n}$ as well as in the isotropic $\mathbb R^{n}$ due to
the freedom in the choice of any homogeneous quasi-norm.


title:
The oldest example of $\pi=3+1/8$ in Sumer: Calculation of the area of a
  circular plot

abstract:
  In this paper I shall show that the formula 0:4,48 times circumference
squared for the area of a circle, which occurs in a few Babylonian mathematical
texts, can be traced back to at the latest the twenty-third century BCE.


title: A note on measures vanishing at infinity

abstract:
  In this paper, we review the basic properties of measures vanishing at
infinity and prove a version of the Riemann--Lebesgue lemma for Fourier
transformable measures.


title:
Study of Black Phosphorus Using Angle-Resolved Polarized Raman
  Spectroscopy with 442 nm Excitation

abstract:
  We investigated 10 to 200 nm thick black phosphorus flakes on SiO2/Si and
polyimide substrates by Angle-resolved Polarized Raman spectra (ARPRS) using
442 nm excitation wavelength. The results revealed that ARPRS with 442 nm
excitation can provide unambiguous, convenient, non-destructive and fast
determination of BP's crystallographic orientation. The substrate and thickness
dependencies of Raman spectra and Raman tensor elements were studied. These
dependencies were shown to be influenced by Raman excitation laser heating
effect. By comparing with in-situ Raman measurements at elevated temperatures,
we were able to quantify the laser-heating effect, which is significant and
hard to avoid for Raman measurements of BP on polyimide substrates due to the
poor thermal conductivity of the substrate. Thermal processing by substrate
heating was shown to have a significant impact on BP on SiO2/Si substrate, but
not for BP on polyimide due to smaller thermal expansion mismatch. Our results
give important insights on Raman Spectroscopy characterizations of BP on
different substrates.


title:
Deterministic parallel algorithms for fooling polylogarithmic juntas and
  the Lovasz Local Lemma

abstract:
  Many randomized algorithms can be derandomized efficiently using either the
method of conditional expectations or probability spaces with low (almost-)
independence. A series of papers, beginning with Luby (1993) and continuing
with Berger & Rompel (1991) and Chari et al. (2000), showed that these
techniques can be combined to give deterministic parallel algorithms for
combinatorial optimization problems involving sums of $w$-juntas. We improve
these algorithms through derandomized variable partitioning and a new code
construction for fooling Fourier characters over $GF(2)$. This reduces the
processor complexity to essentially independent of $w$ while the running time
is reduced from exponential in $w$ to linear in $w$.
  As a key subroutine, we give a new algorithm to generate a probability space
which can fool a given set of neighborhoods. Schulman (1992) gave an NC
algorithm to do so for neighborhoods of size $w \leq O(\log n)$. Our new
algorithm is NC1, with essentially optimal time and processor complexity, when
$w = O(\log n)$; it remains NC up to $w = \text{polylog}(n)$. This answers an
open problem of Schulman.
  One major application of these algorithms is an NC algorithm for the
Lov\'{a}sz Local Lemma. Previous NC algorithms, including the seminal algorithm
of Moser & Tardos (2010) and the work of Chandrasekaran et. al (2013), required
that (essentially) the bad-events could span only $O(\log n)$ variables; we
relax this to $\text{polylog}(n)$ variables. We use this for an $\text{NC}^2$
algorithm for defective vertex coloring, which works for arbitrary degree
graphs.


title: Supercongruences involving Lucas sequences

abstract:
  For $A,B\in\mathbb Z$, the Lucas sequence $u_n(A,B)\ (n=0,1,2,\ldots)$ are
defined by $u_0(A,B)=0$, $u_1(A,B)=1$, and $u_{n+1}(A,B) =
Au_n(A,B)-Bu_{n-1}(A,B)$ $(n=1,2,3,\ldots).$ For any odd prime $p$ and positive
integer $n$, we establish the new result $$\frac{u_{pn}(A,B) - (\frac{A^2-4B}p)
u_n(A,B)}{pn} \in \mathbb Z_p,$$ where $(\frac{\cdot}p)$ is the Legendre symbol
and $\mathbb Z_p$ is the ring of $p$-adic integers.
  Let $p$ be an odd prime and let $n$ be a positive integer. For any integer
$m\not\equiv0\pmod p$, we show that $$\frac1{pn}\bigg(\sum_{k=0}^{pn-1}
\frac{\binom{2k}k}{m^k} -\left(\frac{\Delta}p\right)
\sum_{r=0}^{n-1}\frac{\binom{2r}r}{m^r}\bigg)\in\mathbb Z_p$$ and furthermore
$$\frac1n\bigg(\sum_{k=0}^{pn-1} \frac{\binom{2k}k}{m^k}
-\left(\frac{\Delta}p\right)
\sum_{r=0}^{n-1}\frac{\binom{2r}r}{m^r}\bigg)\equiv
\frac{\binom{2n-1}{n-1}}{m^{n-1}} u_{p-(\frac{\Delta}p)}(m-2,1) \pmod{p^2}$$
where $\Delta=m(m-4)$. We also pose some conjectures for further research.


title: Constellations of primes generated by twin primes

abstract: We study a special set of constellations of primes generated by twin primes.


title:
Comparison of different eigensolvers for calculating vibrational spectra
  using low-rank, sum-of-product basis functions

abstract:
  Vibrational spectra and wavefunctions of polyatomic molecules can be
calculated at low memory cost using low-rank sum-of-product (SOP)
decompositions to represent basis functions generated using an iterative
eigensolver. Using a SOP tensor format does not determine the iterative
eigensolver. The choice of the interative eigensolver is limited by the need to
restrict the rank of the SOP basis functions at every stage of the calculation.
We have adapted, implemented and compared different reduced-rank algorithms
based on standard iterative methods (block-Davidson algorithm, Chebyshev
iteration) to calculate vibrational energy levels and wavefunctions of the
12-dimensional acetonitrile molecule. The effect of using low-rank SOP basis
functions on the different methods is analyzed and the numerical results are
compared with those obtained with the reduced rank block power method
introduced in J. Chem. Phys. 140, 174111 (2014). Relative merits of the
different algorithms are presented, showing that the advantage of using a more
sophisticated method, although mitigated by the use of reduced-rank
sum-of-product functions, is noticeable in terms of CPU time.


title: Scaling Limits for Partial Sums of Power Series

abstract:
  In this thesis we show that the partial sums of the Maclaurin series for a
certain class of entire functions possess scaling limits in various directions
in the complex plane. In doing so we obtain information about the zeros of the
partial sums. We will only assume that these entire functions have a certain
asymptotic behavior at infinity.
  With this information we will partially verify for this class of functions a
conjecture on the location of the zeros of their partial sums known as the
Saff-Varga Width Conjecture.
  The thesis begins by introducing the basics (and the not-so-basics) of the
topic and includes a detailed survey of the relevant literature. The body of
the thesis is then divided into chapters which look at different asymptotic
regimes. Following that a chapter is dedicated to applying the results obtained
to several well-known functions including the sine and cosine functions, Bessel
functions, confluent hypergeometric functions, Airy functions, and parabolic
cylinder functions. This chapter includes many figures which clearly illustrate
the behavior we're interested in. The thesis closes with an appendix which aims
to serve as an instructive introduction to the Laplace method of asymptotic
analysis of integrals.


title: Valley splitting of single-electron Si MOS quantum dots

abstract:
  Silicon-based metal-oxide-semiconductor quantum dots are prominent candidates
for high-fidelity, manufacturable qubits. Due to silicon's band structure,
additional low-energy states persist in these devices, presenting both
challenges and opportunities. Although the physics governing these valley
states has been the subject of intense study, quantitative agreement between
experiment and theory remains elusive. Here, we present data from a new
experiment probing the valley states of quantum dot devices and develop a
theory that is in quantitative agreement with both the new experiment and a
recently reported one. Through sampling millions of realistic cases of
interface roughness, our method provides evidence that, despite radically
different processing, the valley physics between the two samples is essentially
the same. This work provides the first evidence that valley splitting can be
deterministically predicted and controlled in metal oxide semiconductor quantum
dots, a critical requirement for such systems to realize a reliable qubit
platform.


title:
Photon Hall Scattering from Alkaline-earth-like atoms and Alkali-like
  ions

abstract:
  We investigate the possibility of observing a magneto-transverse scattering
of photons from alkaline-earth-like atoms as well as alkali-like ions and
provide orders of magnitude. The transverse magneto-scattering is physically
induced by the interference between two possible quantum transitions of an
outer electron in a S-state, one dispersive electric-dipole transition to a
P-orbital state and a second resonant electric-quadrupole transition to a
P-orbital state. In contrast with previous mechanisms proposed for such an
atomic photonic Hall effect, no real photons are scattered by the
electric-dipole allowed transition, which increases the ratio of Hall current
to background photons significantly. The main experimental challenge is to
overcome the small detection threshold, with only 10^{-5} photons scattered per
atom per second.


title: Frobenius techniques in birational geometry

abstract:
  This is a survey for the 2015 AMS Summer Institute on Algebraic Geometry
about the Frobenius type techniques recently used extensively in positive
characteristic algebraic geometry. We first explain the basic ideas through
simple versions of the fundamental definitions and statements, and then we
survey most of the recent algebraic geometry results obtained using these
techniques.


title:
Control of the Oscillatory Interlayer Exchange Interaction with
  Terahertz Radiation

abstract:
  The oscillatory interlayer exchange interaction between two magnetic layers
separated by a metallic spacer is one of the few coherent quantum phenomena
that persist at room temperature. Here we show that this interaction can be
controlled dynamically by illuminating the sample (e.g. a spin valve) with
radiation in the 10-100 THz range. We predict that the exchange interaction can
be changed from ferromagnetic to anti-ferromagnetic (and vice versa) by tuning
the amplitude and/or the frequency of the radiation. Our chief theoretical
result is an expression that relates the dynamical exchange interaction to the
static one that has already been extensively measured.


title: On uniqueness sets for spaces of holomorphic functions

abstract:
  In this article are improved and refined some of our results prior to our
recent article from the journal "Russian Mathematics (Izvestiya VUZ.
Matematika)" in 2015 at the expense of our latest results in 2016 on lower
estimates of subharmonic functions by the logarithm module nonzero holomorphic
function.


title: Crossing the Road Without Traffic Lights: An Android-based Safety Device

abstract:
  In the absence of pedestrian crossing lights, finding a safe moment to cross
the road is often hazardous and challenging, especially for people with visual
impairments. We present a reliable low-cost solution, an Android device
attached to a traffic sign or lighting pole near the crossing, indicating
whether it is safe to cross the road. The indication can be by sound, display,
vibration, and various communication modalities provided by the Android device.
The integral system camera is aimed at approaching traffic. Optical flow is
computed from the incoming video stream, and projected onto an influx map,
automatically acquired during a brief training period. The crossing safety is
determined based on a 1-dimensional temporal signal derived from the
projection. We implemented the complete system on a Samsung Galaxy K-Zoom
Android smartphone, and obtained real-time operation. The system achieves
promising experimental results, providing pedestrians with sufficiently early
warning of approaching vehicles. The system can serve as a stand-alone safety
device, that can be installed where pedestrian crossing lights are ruled out.
Requiring no dedicated infrastructure, it can be powered by a solar panel and
remotely maintained via the cellular network.


title: Rotating Optical Tubes: An Archimedes' Screw for Atoms

abstract:
  The classical dynamics of a cold atom trapped inside a vertical rotating
helical optical tube (HOT) is investigated by taking also into account the
gravitational field. The resulting equations of motion are solved numerically.
The rotation induces a vertical motion for an atom initially at rest. The
motion is a result of the action of two inertial forces, namely the centrifugal
force and the Coriolis force. Both inertial forces force the atom to rotate in
a direction opposite to that of the angular velocity of the HOT. The frequency
and the turning points of the atom's global oscillation can be controlled by
the value and the direction of the angular velocity of the HOT. However, at
large values of the angular velocity of the HOT the atom can escape from the
global oscillation and be transported along the axis of the HOT. In this case,
the rotating HOT operates as an Optical Archimedes' Screw (OAS) for atoms.


title: Flat SML modules and reflexive functors

abstract:
  We give some functorial characterizations of flat strict Mittag-Leffler
modules. We characterize reflexive functors of modules with similar tools,
definitions and theorems.


title: Generating functions for symmetric and shifted symmetric functions

abstract:
  We describe generating functions for several important families of classical
symmetric functions and shifted Schur functions. The approach is originated
from vertex operator realization of symmetric functions and offers a unified
method to treat various families of symmetric functions and their shifted
analogues.


title:
Particle dynamics in self-generated dunes over a range of hydraulic and
  sediment transport conditions using LES--DEM

abstract:
  Direct measurement of vertical and longitudinal sediment fluxes on migrating
sandy bedforms are extremely difficult to perform in both the field and
laboratory. In this study we use the LES--DEM (large eddy simulation--discrete
element method) solver SediFoam to examine the individual particle motions and
resulting fluxes in a domain of self-generated dunes. In SediFoam, the motions
of, and collisions among, the sediment grains as well as their interactions
with surrounding turbulent flows are resolved. The numerical simulations are
performed over a range of transport settings, spanning bedform inception
through washout conditions, to examine the individual particle dynamics. The
space-time evolution of dune surfaces is demonstrated. The self-generated dunes
are stable at relatively low Reynolds numbers, but then become increasingly
unstable at higher Reynolds numbers; eventually washing out as the number of
bypass grains and particles in suspension increase. Data from the simulation
are used to examine the vertical entrainment rate of particles and the
fractionation of total sediment load into bed and suspended fractions as a
function of transport conditions. The study also compares the sediment
transport rate obtained using the bedform geometry and celerity to the true
transport rate at different transport stages.


title:
Continuous dependence and uniqueness for lateral Cauchy problems for
  linear integro-differential parabolic equations

abstract:
  Via Carleman estimates we prove uniqueness and continuous dependence results
for lateral Cauchy problems for linear integro-differential parabolic equations
without initial conditions. The additional information supplied prescribes the
conormal derivative of the temperature on a relatively open subset of the
lateral boundary of the space-time domain.


title:
Strong anisotropy within a Heisenberg model in the J=1/2 insulating
  state of Sr2Ir0.8Ru0.2O4

abstract:
  The dispersive magnetic excitations in Sr2IrO4 have previously been well
described within an isospin-1/2 Heisenberg model on a square lattice that
revealed parallels with La2CuO4. Here we investigate the inelastic spectra of
Sr2Ir0.8Ru0.2O4 with resonant inelastic x-ray scattering (RIXS) at the Ir
L3-edge. The results are well described using linear spin-wave theory within a
similar Heisenberg model applicable to Sr2IrO4, however the disorder induced by
the substitution of 20% Ir4+ ions for Ru4+ removes longer range exchange
interactions. A large spin-gap (40 meV) is measured indicating strong
anisotropy from spin-orbit coupling that is manifest due to the altered
magnetic structure in Sr2Ir0.8Ru0.2O4 with c-axis aligned moments compared to
the basal plane moments in the parent. Collectively the results indicate the
robustness of a Heisenberg model description even when the magnetic structure
is altered and the J=1/2 moments diluted.


title: The Effective Field Theory of nonsingular cosmology

abstract:
  In this paper, we explore the nonsingular cosmology within the framework of
the Effective Field Theory(EFT) of cosmological perturbations. Due to the
recently proved no-go theorem, any nonsingular cosmological models based on the
cubic Galileon suffer from pathologies. We show how the EFT could help us
clarify the origin of the no-go theorem, and offer us solutions to break the
no-go. Particularly, we point out that the gradient instability can be removed
by using some spatial derivative operators in EFT. Based on the EFT
description, we obtain a realistic healthy nonsingular cosmological model, and
show the perturbation spectrum can be consistent with the observations.


title: Disconnecting structure and dynamics in glassy thin films

abstract:
  Nanometrically thin glassy films depart strikingly from the behavior of their
bulk counterparts. We investigate whether the dynamical differences between
bulk and thin film glasses can be understood by differences in local
microscopic structure. We employ machine-learning methods that have previously
identified strong correlations between local structure and particle
rearrangement dynamics in bulk systems. We show that these methods completely
fail to detect key aspects of thin-film glassy dynamics. Furthermore, we show
that no combination of local structural features drawn from a very general set
of two- and multi-point functions is able to distinguish between particles at
the center of film and those in intermediate layers where the dynamics are
strongly perturbed.


title:
$SL(2, Z)$ invariant rotating $(m,n)$ strings in $AdS_3\times S^3$ with
  mixed flux

abstract:
  We study rigidly rotating and pulsating $(m,n)$ strings in $AdS_3 \times S^3$
with mixed three form flux. The $AdS_3 \times S^3$ background with mixed three
form flux is obtained in the near horizon limit of $SL(2,Z)$-transformed
solution, corresponding to the bound state of NS5-branes and fundamental
strings. We study the probe $(m,n)-$string in this background by solving the
manifest $SL(2,Z)-$covariant form of the action. We find out the dyonic giant
magnon and single spike solutions corresponding to the equations of motion of a
probe string in this background and find out various relationships among the
conserved charges. We further study a class of pulsating $(m,n)$ string in
$AdS_3$ with mixed three form flux.


title: On the Abundance Problem for $3$-folds in characteristic $p>5$

abstract:
  In this article we prove two cases of the abundance conjecture for $3$-folds
in characteristic $p>5$: $(i)$ $(X, \Delta)$ is KLT and $\kappa(X,
K_X+\Delta)=1$, and $(ii)$ $(X, 0)$ is KLT, $K_X\equiv 0$ and $X$ is not
uniruled.


title:
Runge-Kutta discontinuous Galerkin methods for the special relativistic
  magnetohydrodynamics

abstract:
  This paper develops $P^K$-based non-central and central Runge-Kutta
discontinuous Galerkin (DG) methods with WENO limiter for the one- and
two-dimensional special relativistic magnetohydrodynamical (RMHD) equations,
$K=1,2,3$. The non-central DG methods are locally divergence-free, while the
central DG are "exactly" divergence-free but have to find two approximate
solutions defined on mutually dual meshes. The adaptive WENO limiter first
identifies the "troubled" cells by using a modified TVB minmod function, and
then uses the WENO technique to locally reconstruct a new polynomial of degree
$(2K+1)$ inside the "troubled" cells replacing the DG solution by based on the
cell average values of the DG solutions in the neighboring cells as well as the
original cell averages of the "troubled" cells. The WENO limiting procedure
does not destroy the locally or "exactly" divergence-free property of magnetic
field and is only employed for finite "troubled" cells so that the
computational cost can be as little as possible. Several test problems in one
and two dimensions are solved by using our non-central and central Runge-Kutta
DG methods with WENO limiter. The numerical results demonstrate that our
methods are stable, accurate, and robust in resolving complex wave structures.


title: Finite atomic lattices and their monomial ideals

abstract:
  This paper primarily studies monomial ideals by their associated
lcm-lattices. It first introduces notions of weak coordinatizations of finite
atomic lattices which have weaker hypotheses than coordinatizations and shows
the characterizations of all such weak coordinatizations. It then defines a
finite super-atomic lattice in $\mathcal{L}(n)$, investigates the structures of
$\mathcal{L}(n)$ by their super-atomic lattices and proposes an algorithm to
calculate all the super-atomic lattices in $\mathcal{L}(n)$. It finally
presents a specific labeling of finite atomic lattice and obtains the
conditions that the specific labelings of finite atomic lattices are the weak
coordinatizations or the coordinatizations by using the terminology of
super-atomic lattices.


title: Complexity of syntactical tree fragments of Independence-Friendly logic

abstract:
  A dichotomy result of Sevenster (2014) completely classified the quantifier
prefixes of regular Independence-Friendly (IF) logic according to the patterns
of quantifier dependence they contain. On one hand, prefixes that contain
"Henkin" or "signalling" patterns were shown to characterize fragments of IF
logic that capture NP-complete problems; all the remaining prefixes were shown
instead to be essentially first-order.
  In the present paper we develop the machinery which is needed in order to
extend the results of Sevenster to non-prenex, regular IF sentences. This
involves shifting attention from quantifier prefixes to a (rather general)
class of syntactical tree prefixes.
  We partially classify the fragments of regular IF logic that are thus
determined by syntactical trees; in particular, a) we identify three tree
prefixes that are neither signalling nor Henkin, and yet express NP-complete
problems and other second-order concepts; and b) we give more general criteria
for checking the first-orderness of an IF sentence.


title:
1.3mm polarized emission in the circumstellar disk of a massive
  protostar

abstract:
  We present the first resolved observations of the 1.3mm polarized emission
from the disk-like structure surrounding the high-mass protostar Cepheus A HW2.
These CARMA data partially resolve the dust polarization, suggesting an uniform
morphology of polarization vectors with an average position angle of 57 degrees
and an average polarization fraction of 2.0%. The distribution of the
polarization vectors can be attributed to (1) the direct emission of
magnetically aligned grains of dust by a uniform magnetic field, or (2) the
pattern produced by the scattering of an inclined disk. We show that both
models can explain the observations, and perhaps a combination of the two
mechanisms produce the polarized emission. A third model including a toroidal
magnetic field does not match the observations. Assuming scattering is the
polarization mechanism, these observations suggest that during the first few
10000 years of high-mass star formation, grain sizes can grow from 1 to several
10s micron.


title: A note on the multiplicative gamma process

abstract:
  Adaptive dimensionality reduction in high-dimensional problems is a key topic
in statistics. The multiplicative gamma process takes a relevant step in this
direction, but improved studies on its properties are required to ease
implementation. This note addresses such aim.


title: From integral estimates of functions to uniformly and locally averaged

abstract:
  Problems pointwise estimates from above functions or its averages often arise
in the function theory under known integral restrictions on the growth of this
function. We offer an approach to such problems based on the integral Jensen's
inequality with the convex function


title:
Nonlinear modes disentangle glassy and Goldstone modes in structural
  glasses

abstract:
  One outstanding problem in the physics of glassy solids is understanding the
statistics and properties of the low-energy excitations that stem from the
disorder that characterizes these systems' microstructure. In this work we
introduce a family of algebraic equations whose solutions represent collective
displacement directions (modes) in the multi-dimensional configuration space of
a structural glass. We explain why solutions of the algebraic equations, coined
nonlinear glassy modes, are quasi-localized low-energy excitations. We present
an iterative method to solve the algebraic equations, and use it to study the
energetic and structural properties of a selected subset of their solutions
constructed by starting from a normal mode analysis of the potential energy of
a model glass. Our key result is that the structure and energies associated
with harmonic glassy vibrational modes and their nonlinear counterparts
converge in the limit of very low frequencies. As nonlinear modes never suffer
hybridizations, our result implies that the presented theoretical framework
constitutes a robust alternative definition of `soft glassy modes' in the
thermodynamic limit, in which Goldstone modes overwhelm and destroy the
identity of low-frequency harmonic glassy modes.


title:
Remarks on the $\Gamma $-regularization of Non-convex and
  Non-semi-continuous Functions on Topological Vector Spaces

abstract:
  We show that the minimization problem of any non-convex and non-lower
semi-continuous function on a compact convex subset of a locally convex real
topological vector space can be studied via an associated convex and lower
semi-continuous function $\Gamma \left( h\right) $. This observation uses the
notion of $\Gamma $-regularization as a key ingredient. As an application we
obtain, on any locally convex real space, a generalization of the Lanford
III-Robinson theorem which has only been proven for separable real Banach
spaces. The latter is a characterization of subdifferentials of convex
continuous functions.


title: Finding Euler Tours in the StrSort Model

abstract:
  We present a first algorithm for finding Euler tours in undirected graphs in
the StrSort model. This model is a relaxation of the semi streaming model. The
graph is given as a stream of its edges and can only be read sequentially, but
while doing a pass over the stream we are allowed to write out another stream
which will be the input for the next pass. In addition, items in the stream are
sorted between passes. This model was introduced by Aggarwal et al. in 2004.
Here we apply this model to the problem of finding an Euler tour in a graph (or
to decide that the graph does not admit an Euler tour). The algorithm works in
two steps. In the first step, a single pass is conducted while a linear (in the
number of vertices $n$) amount of RAM is required. In the second step,
$\mathcal O(\log(n))$ passes are conducted while only $\mathcal O(\log(n))$ RAM
is required.
  We use an alteration of the algorithm of Atallah and Vishkin from 1984 for
finding Euler tours in parallel. It finds a partition of edge-disjoint circuits
and arranges them in a tree expressing their connectivity. Then the circuits
are merged according to this tree. In order to minimize the needed amount of
RAM, we evade the need to store the entire tree and use techniques suggested by
Aggarwal et al. to exchange information concerning the merging of circuits.


title: From integral estimates of functions to uniform. I. Exact versions

abstract:
  We give a general method to obtain from the integral restrictions of
functions sharp pointwise and uniform estimates of these functions. This scheme
is illustrated by the examples for Fock\,--\,Bargmann spaces of entire
functions of several variables and Bergman spaces in balls and polydiscs.


title: Maximum entropy models capture melodic styles

abstract:
  We introduce a Maximum Entropy model able to capture the statistics of
melodies in music. The model can be used to generate new melodies that emulate
the style of the musical corpus which was used to train it. Instead of using
the $n-$body interactions of $(n-1)-$order Markov models, traditionally used in
automatic music generation, we use a $k-$nearest neighbour model with pairwise
interactions only. In that way, we keep the number of parameters low and avoid
over-fitting problems typical of Markov models. We show that long-range musical
phrases don't need to be explicitly enforced using high-order Markov
interactions, but can instead emerge from multiple, competing, pairwise
interactions. We validate our Maximum Entropy model by contrasting how much the
generated sequences capture the style of the original corpus without
plagiarizing it. To this end we use a data-compression approach to discriminate
the levels of borrowing and innovation featured by the artificial sequences.
The results show that our modelling scheme outperforms both fixed-order and
variable-order Markov models. This shows that, despite being based only on
pairwise interactions, this Maximum Entropy scheme opens the possibility to
generate musically sensible alterations of the original phrases, providing a
way to generate innovation.


title: The strong Feller property for singular stochastic PDEs

abstract:
  We show that the Markov semigroups generated by a large class of singular
stochastic PDEs satisfy the strong Feller property. These include for example
the KPZ equation and the dynamical $\Phi^4_3$ model. As a corollary, we prove
that the Brownian bridge measure is the unique invariant measure for the KPZ
equation with periodic boundary conditions.


title: Sequential pattern formation governed by signaling gradients

abstract:
  Rhythmic and sequential segmentation of the embryonic body plan is a vital
developmental patterning process in all vertebrate species. However, a
theoretical framework capturing the emergence of dynamic patterns of gene
expression from the interplay of cell oscillations with tissue elongation and
shortening and with signaling gradients, is still missing. Here we show that a
set of coupled genetic oscillators in an elongating tissue that is regulated by
diffusing and advected signaling molecules can account for segmentation as a
self-organized patterning process. This system can form a finite number of
segments and the dynamics of segmentation and the total number of segments
formed depend strongly on kinetic parameters describing tissue elongation and
signaling molecules. The model accounts for existing experimental perturbations
to signaling gradients, and makes testable predictions about novel
perturbations. The variety of different patterns formed in our model can
account for the variability of segmentation between different animal species.


title:
Is psychosis caused by defective dissociation? An Artificial Life model
  for schizophrenia

abstract:
  Both neurobiological and environmental factors are known to play a role in
the origin of schizophrenia, but no model has been proposed that accounts for
both. This work presents a functional model of schizophrenia that merges
psychodynamic elements with ingredients borrowed from the theory of
psychological traumas, and evidences the interplay of traumatic experiences and
defective mental functions in the pathogenesis of the disorder. Our model
foresees that dissociation is a standard tool used by the mind to protect
itself from emotional pain. In case of repeated traumas, the mind learns to
adopt selective forms of dissociation to avoid pain without losing touch with
external reality. We conjecture that this process is defective in
schizophrenia, where dissociation is either too weak, giving rise to positive
symptoms, or too strong, causing negative symptoms.


title: Uniform Avoidance Coupling of Simple Random Walks

abstract:
  We start by introducing avoidance coupling of Markov chains, with an overview
of existing results. We then introduce and motivate a new notion, uniform
avoidance coupling. We show that the only Markovian avoidance coupling on a
cycle is of this type, and that uniform avoidance coupling of simple random
walks is impossible on trees, and prove that it is possible on several classes
of graphs. We also derive a condition on the vertex neighborhoods in a graph
equivalent to that graph admitting a uniform avoidance coupling of simple
random walks, and an algorithm that tests this with run time polynomial in the
number of vertices.


title: Single-atom spectroscopy of phosphorus dopants implanted into graphene

abstract:
  One of the keys behind the success of the modern semiconductor technology has
been the ion implantation of silicon, which allows its electronic properties to
be tailored. For similar purposes, heteroatoms have been introduced into carbon
nanomaterials both during growth and using post-growth methods. However, due to
the nature of the samples, it has been challenging to determine whether the
heteroatoms have been incorporated into the lattice as intended, with direct
observations so far being limited to N and B dopants, and incidental Si
impurities. Furthermore, ion implantation of these materials is more
challenging due to the requirement of very low ion energies and atomically
clean surfaces. Here, we provide the first atomic-resolution imaging and
electron energy loss spectroscopy (EELS) evidence of phosphorus atoms
incorporated into the graphene lattice by low-energy ion irradiation. The
measured P L-edge response of an single-atom EELS spectrum map shows excellent
agreement with an ab initio spectrum simulation, conclusively identifying the P
in a buckled substitutional configuration. Our results demonstrate the
viability of phosphorus as a lattice dopant in $sp^2$-bonded carbon structures
and provide its unmistakeable fingerprint for further studies.


title:
Reproducing pairs of measurable functions and partial inner product
  spaces

abstract:
  We continue the analysis of reproducing pairs of weakly measurable functions,
which generalize continuous frames. More precisely, we examine the case where
the defining measurable functions take their values in a partial inner product
space (PIP spaces). Several examples, both discrete and continuous, are
presented.


title: Computing All Distinct Squares in Linear Time for Integer Alphabets

abstract:
  Given a string on an integer alphabet, we present an algorithm that computes
the set of all distinct squares belonging to this string in time linear to the
string length. As an application, we show how to compute the tree topology of
the minimal augmented suffix tree in linear time. Asides from that, we
elaborate an algorithm computing the longest previous table in a succinct
representation using compressed working space.


title: Quantum authentication with key recycling

abstract:
  We show that a family of quantum authentication protocols introduced in
[Barnum et al., FOCS 2002] can be used to construct a secure quantum channel
and additionally recycle all of the secret key if the message is successfully
authenticated, and recycle part of the key if tampering is detected. We give a
full security proof that constructs the secure channel given only insecure
noisy channels and a shared secret key. We also prove that the number of
recycled key bits is optimal for this family of protocols, i.e., there exists
an adversarial strategy to obtain all non-recycled bits. Previous works
recycled less key and only gave partial security proofs, since they did not
consider all possible distinguishers (environments) that may be used to
distinguish the real setting from the ideal secure quantum channel and secret
key resource.


title:
Finite-dimensional representations of minimal nilpotent W-algebras and
  zigzag algebras

abstract:
  Let $\frak g$ be a simple finite-dimensional Lie algebra over an
algebraically closed field $\mathbb F$ of characteristic 0. We denote by
$\operatorname{U}(\frak g)$ the universal enveloping algebra of $\frak g$. To
any nilpotent element $e\in \frak g$ one can attach an associative (and
noncommutative as a general rule) algebra $\operatorname{U}({\frak g},~e)$
which is in a proper sense a "tensor factor" of $\operatorname{U}(\frak g)$. In
this article we consider the case in which $\frak g$ is simple and $e$ belongs
of the minimal nonzero nilpotent orbit of $\frak g$. Under these assumptions
$\operatorname{U}({\frak g}, e)$ was described explicitly in terms of
generators and relations. One can expect that the representation theory of
$\operatorname{U}({\frak g}, e)$ would be very similar to the representation
theory of $\operatorname{U}(\frak g)$. For example one can guess that the
category of finite-dimensional $\operatorname{U}({\frak g}, e)$-modules is
semisimple.
  The goal of this article is to show that this is the case if $\frak g$ is not
simply-laced. We also show that, if $\frak g$ is simply-laced and is not of
type $A_n$, then the regular block of finite-dimensional
$\operatorname{U}({\frak g}, e)$-modules is equivalent to the category of
finite-dimensional modules of a zigzag algebra.


title: Long-time existence for Yang-Mills flow

abstract:
  We establish that finite-time singularities do not occur in four-dimensional
Yang-Mills flow, confirming the conjecture of Schlatter, Struwe, and
Tahvildar-Zadeh. The proof relies on a weighted energy identity and sharp decay
estimates in the neck region.


title:
Statistics of Robust Optimization: A Generalized Empirical Likelihood
  Approach

abstract:
  We study statistical inference and distributionally robust solution methods
for stochastic optimization problems, focusing on confidence intervals for
optimal values and solutions that achieve exact coverage asymptotically. We
develop a generalized empirical likelihood framework---based on distributional
uncertainty sets constructed from nonparametric $f$-divergence balls---for
Hadamard differentiable functionals, and in particular, stochastic optimization
problems. As consequences of this theory, we provide a principled method for
choosing the size of distributional uncertainty regions to provide one- and
two-sided confidence intervals that achieve exact coverage. We also give an
asymptotic expansion for our distributionally robust formulation, showing how
robustification regularizes problems by their variance. Finally, we show that
optimizers of the distributionally robust formulations we study enjoy
(essentially) the same consistency properties as those in classical sample
average approximations. Our general approach applies to quickly mixing
stationary sequences, including geometrically ergodic Harris recurrent Markov
chains.


title: Perron's method for nonlocal fully nonlinear equations

abstract:
  This paper is concerned with existence of viscosity solutions of
non-translation invariant nonlocal fully nonlinear equations. We construct a
discontinuous viscosity solution of such nonlocal equation by Perron's method.
If the equation is uniformly elliptic in the sense of \cite{SS}, we prove the
discontinuous viscosity solution is H\"older continuous and thus it is a
viscosity solution.


title: On the dynamic suction pumping of blood cells in tubular hearts

abstract:
  Around the third week after gestation in embryonic development, the human
heart consists only of a valvless tube, unlike a fully developed adult heart,
which is multi-chambered. At this stage in development, the heart valves have
not formed and so net flow of blood through the heart must be driven by a
different mechanism. It is hypothesized that there are two possible mechanisms
that drive blood flow at this stage - Liebau pumping (dynamic suction pumping
or valveless pumping) and peristaltic pumping. We implement the immersed
boundary method with adaptive mesh refinement (IBAMR) to numerically study the
effect of hematocrit on the circulation around a valveless. Both peristalsis
and dynamic suction pumping are considered. In the case of dynamic suction
pumping, the heart and circulatory system is simplified as a flexible tube
attached to a relatively rigid racetrack. For some Womersley number (Wo)
regimes, there is significant net flow around the racetrack. We find that the
addition of flexible blood cells does not significantly affect flow rates
within the tube for Wo $\leq$ 10. On the other hand, peristalsis consistently
drives blood around the racetrack for all Wo and for all hematocrit considered.


title: Arithmetic expanders and deviation bounds for random tensors

abstract:
  We prove hypergraph variants of the celebrated Alon-Roichman theorem on
spectral expansion of sparse random Cayley graphs. One of these variants
implies that for every prime $p\geq 3$ and any $\varepsilon > 0$, there exists
a set of directions $D\subseteq \mathbb{F}_p^n$ of size
$O_{p,\varepsilon}(p^{(1-1/p +o(1))n})$ such that for every set $A\subseteq
\mathbb{F}_p^n$ of density $\alpha$, the fraction of lines in $A$ with
direction in $D$ is within $\varepsilon\alpha$ of the fraction of all lines in
$A$. Our proof uses new deviation bounds for sums of independent random
multi-linear forms taking values in a generalization of the Birkhoff polytope.
The proof of our deviation bound is based on Dudley's integral inequality and a
probabilistic construction of $\varepsilon$-nets. Using the polynomial method
we prove that a Cayley hypergraph with edges generated by a set~$D$ as above
requires $|D| \geq \Omega_p(n^{p-1})$ for (our notion of) spectral expansion
for hypergraphs.


title: Electronic Properties of Nano and Molecular Quantum Devices

abstract:
  The exploring and understanding the electronic properties of molecules
connected to metallic leads is a vital part of nanoscience if molecule is to
have a future. This thesis documents a study for various families of organic
and organometallic molecules, which offer unique concepts and new insights into
the electronic properties of molecular junctions. Different families of
molecules were studied using a combination of density functional theory DFT and
nonequilibrium Greens function formalism of transport theory.The main results
of this thesis are as follows. A quantum circuit rule for combining quantum
interference effects in the conductive properties of oligo phenyleneethynylene
OPE type molecules possessing three aromatic rings was investigated both
theoretically and experimentally. The theoretical and experimental studies of
conductance and the decay of conductance as a function of molecular length
within a homologous series of oligoynes. The single molecule conductances of a
series of bis-terpyridine complexes featuring Ru, Fe, and Co metal ions and
trimethylsilylethynyl or thiomethyl surface contact groups have been determined
theoretically and experimentally.


title: Elliptic Curves in Recreational Number Theory

abstract:
  Several problems which could be thought of as belonging to recreational
mathematics are described. They are all such that solutions to the problem
depend on finding rational points on elliptic curves. Many of the problems
considered lead to the search for points of very large height on the curves,
which (as yet) have not been found.


title:
Observation of the spin-polarized surface state in a noncentrosymmetric
  superconductor BiPd

abstract:
  Recently, noncentrosymmetric superconductor BiPd has attracted considerable
research interest due to the possibility of hosting topological
superconductivity. Here we report a systematic high-resolution angle-resolved
photoemission spectroscopy (ARPES) and spin-resolved ARPES study of the normal
state electronic and spin properties of BiPd. Our experimental results show the
presence of a surface state at higher-binding energy with the location of Dirac
point at around 700 meV below the Fermi level. The detailed photon energy,
temperature-dependent and spin-resolved ARPES measurements complemented by our
first principles calculations demonstrate the existence of the spin polarized
surface states at high-binding energy. The absence of such spin-polarized
surface states near the Fermi level negates the possibility of a topological
superconducting behavior on the surface. Our direct experimental observation of
spin-polarized surface states in BiPd provides critical information that will
guide the future search for topological superconductivity in noncentrosymmetric
materials.


title:
Measurement Error in Atomic-Scale STEM-EDS Mapping of a Model Oxide
  Interface

abstract:
  With the development of affordable aberration-correctors, analytical scanning
transmission electron microscopy (STEM) studies of complex interfaces can now
be conducted at high spatial resolution at laboratories worldwide.
Energy-dispersive X-ray spectroscopy (STEM-EDS) in particular has grown in
popularity, since it enables elemental mapping over a wide range of ionization
energies. However, the interpretation of atomically-resolved data is greatly
complicated by beam-sample interactions that are often overlooked by novice
users. Here we describe the practical factors---namely, sample thickness and
the choice of ionization edge---that affect the quantification of a model
perovskite oxide interface. Our measurements of the same sample in regions of
different thickness indicate that interface profiles can vary by as much as 2-5
unit cells, depending on the spectral feature. This finding is supported by
multislice simulations, which reveal that on-axis maps of even perfectly abrupt
interfaces exhibit significant delocalization. Quantification of thicker
samples is further complicated by channeling to heavier sites across the
interface, as well as an increased signal background. We show that extreme care
must be taken to prepare samples to minimize channeling effects and argue that
it may not be possible to extract atomically-resolved information from many
chemical maps.


title: Subharmonic Versions of Valiron Theorem on Entire Functions

abstract:
  We estimate the growth of the canonical integral of Hadamard-Weierstrass of
measure of finite order on the complex plane by the type of counting function
or average counting function of this measure


title:
Computation of maximum likelihood estimates in cyclic structural
  equation models

abstract:
  Software for computation of maximum likelihood estimates in linear structural
equation models typically employs general techniques from non-linear
optimization, such as quasi-Newton methods. In practice, careful tuning of
initial values is often required to avoid convergence issues. As an alternative
approach, we propose a block-coordinate descent method that cycles through the
considered variables, updating only the parameters related to a given variable
in each step. We show that the resulting block update problems can be solved in
closed form even when the structural equation model comprises feedback cycles.
Furthermore, we give a characterization of the models for which the
block-coordinate descent algorithm is well-defined, meaning that for generic
data and starting values all block optimization problems admit a unique
solution. For the characterization, we represent each model by its mixed graph
(also known as path diagram), which leads to criteria that can be checked in
time that is polynomial in the number of considered variables.


title: Algebraic Families of Harish-Chandra Pairs

abstract:
  Mathematical physicists have studied degenerations of Lie groups and their
representations, which they call contractions. In this paper we study these
contractions, and also other families, within the framework of algebraic
families of Harish-Chandra modules. We construct a family that incorporates
both a real reductive group and its compact form, separate parts of which have
been studied individually as contractions. We give a complete classification of
generically irreducible families of Harish-Chandra modules in the case of the
family associated to SL(2, R).


title:
Tatooine's Future: The Eccentric Response of Kepler's Circumbinary
  Planets to Common-Envelope Evolution of their Host Stars

abstract:
  Inspired by the recent Kepler discoveries of circumbinary planets orbiting
nine close binary stars, we explore the fate of the former as the latter evolve
off the main sequence. We combine binary star evolution models with dynamical
simulations to study the orbital evolution of these planets as their hosts
undergo common-envelope stages, losing in the process a tremendous amount of
mass on dynamical timescales. Five of the systems experience at least one
Roche-lobe overflow and common-envelope stages (Kepler-1647 experiences three),
and the binary stars either shrink to very short orbits or coalesce; two
systems trigger a double-degenerate supernova explosion. Kepler's circumbinary
planets predominantly remain gravitationally bound at the end of the
common-envelope phase, migrate to larger orbits, and may gain significant
eccentricity; their orbital expansion can be more than an order of magnitude
and can occur over the course of a single planetary orbit. The orbits these
planets can reach are qualitatively consistent with those of the currently
known post-common-envelope, eclipse-time variations circumbinary candidates.
Our results also show that circumbinary planets can experience both modes of
orbital expansion (adiabatic and non-adiabatic) if their host binaries undergo
more than one common-envelope stage; multiplanet circumbinary systems like
Kepler-47 can experience both modes during the same common-envelope stage.
Additionally, unlike Mercury orbiting the Sun, a circumbinary planet with the
same semi-major axis can survive the common envelope evolution of a close
binary star with a total mass of 1 MSun.


title: Restoring STM images via Sparse Coding: noise and artifact removal

abstract:
  In this article, we present a denoising algorithm to improve the
interpretation and quality of scanning tunneling microscopy (STM) images. Given
the high level of self-similarity of STM images, we propose a denoising
algorithm by reformulating the true estimation problem as a sparse regression,
often termed sparse coding. We introduce modifications to the algorithm to cope
with the existence of artifacts, mainly dropouts, which appear in a structured
way as consecutive line segments on the scanning direction. The resulting
algorithm treats the artifacts as missing data, and the estimated values
outperform those algorithms that substitute the outliers by a local filtering.
We provide code implementations for both Matlab and Gwyddion.


title: Introduction to Quantum Electromagnetic Circuits

abstract:
  The article is a short opinionated review of the quantum treatment of
electromagnetic circuits, with no pretension to exhaustiveness. This review,
which is an updated and modernized version of a previous set of Les Houches
School lecture notes, has 3 main parts. The first part describes how to
construct a Hamiltonian for a general circuit, which can include dissipative
elements. The second part describes the quantization of the circuit, with an
emphasis on the quantum treatment of dissipation. The final part focuses on the
Josephson non-linear element and the main linear building blocks from which
superconducting circuits are assembled. It also includes a brief review of the
main types of superconducting artificial atoms, elementary multi-level quantum
systems made from basic circuit elements.


title:
Epsilon-Near-Zero behavior from plasmonic Dirac point: theory and
  realization using two-dimensional materials

abstract:
  The electromagnetic response of a two-dimensional metal embedded in a
periodic array of a dielectric host can give rise to a plasmonic Dirac point
that emulates Epsilon-Near-Zero (ENZ) behavior. This theoretical result is
extremely sensitive to tructural features like periodicity of the dielectric
medium and thickness imperfections. We propose that such a device can actually
be realized by using graphene as the 2D metal and materials like the layered
semiconducting transition-metal dichalcogenides or hexagonal boron nitride as
the dielectric host. We propose a systematic approach, in terms of design
characteristics, for constructing metamaterials with linear, elliptical and
hyperbolic dispersion relations which produce ENZ behavior, normal or negative
diffraction.


title: Duality Covariant Solutions in Extended Field Theories

abstract:
  Double field theory and exceptional field theory are formulations of
supergravity that make certain dualities manifest symmetries of the action. To
achieve this, the geometry is extended by including dual coordinates
corresponding to winding modes of the fundamental objects. This geometrically
unifies the spacetime metric and the gauge fields (and their local symmetries)
in a generalized geometry. Solutions to these extended field theories take the
simple form of waves and monopoles in the extended space. From a supergravity
point of view they appear as 1/2 BPS objects such as the string, the membrane
and the fivebrane in ordinary spacetime. In this thesis double field theory and
exceptional field theory are introduced, solutions to their equations of motion
are constructed and their properties are analyzed. Further it is established
how isometries in the extended space give rise to duality relations between the
supergravity solutions. Extensions to these core ideas include studying
Goldstone modes, probing singularities at the core of solutions and localizing
them in winding space. The relation of exceptional field theory to F-theory is
also covered providing an action for the latter and incorporating the duality
between M-theory and F-theory.


title:
The evolution of the star formation rate function and cosmic star
  formation rate density of galaxies at $z \sim 1-4$

abstract:
  We investigate the evolution of the galaxy Star Formation Rate Function
(SFRF) and Cosmic Star Formation Rate Density (CSFRD) of $z\sim 1-4 $ galaxies,
using cosmological Smoothed Particle Hydrodynamic (SPH) simulations and a
compilation of UV, IR and H$\alpha$ observations. These tracers represent
different populations of galaxies with the IR light being a probe of objects
with high star formation rates and dust contents, while UV and H$\alpha$
observations provide a census of low star formation galaxies where mild
obscuration occurs. We compare the above SFRFs with the results of SPH
simulations run with the code {\small{P-GADGET3(XXL)}}. We focus on the role of
feedback from Active Galactic Nuclei (AGN) and supernovae in form of galactic
winds. The AGN feedback prescription that we use decreases the simulated CSFRD
at $z < 3$ but is not sufficient to reproduce the observed evolution at higher
redshifts. We explore different wind models and find that the key factor for
reproducing the evolution of the observed SFRF and CSFRD at $z \sim1-4$ is the
presence of a feedback prescription that is prominent at high redshifts ($z \ge
4$) and becomes less efficient with time. We show that variable galactic winds
which are efficient at decreasing the SFRs of low mass objects are quite
successful in reproducing the observables.


title: Strong lensing by fermionic dark matter in galaxies

abstract:
  It has been shown that a self-gravitating system of massive keV fermions in
thermodynamic equilibrium correctly describes the dark matter (DM) distribution
in galactic halos and predicts a denser quantum core towards the center of the
configuration. Such a quantum core, for a fermion mass in the range of $50$ keV
$\lesssim m c^2 \lesssim 345$ keV, can be an alternative interpretation of the
central compact object in Sgr A*. We present in this work the gravitational
lensing properties of this novel DM model in Milky Way-like spiral galaxies. We
describe the lensing effects of the pure DM component both on halo scales,
where we compare them to the effects of the Navarro-Frenk-White and the
Non-Singular Isothermal Sphere DM models, and near the galaxy center, where we
compare them with the effects of a Schwarzschild BH. For the particle mass
leading to the most compact DM core, $m c^2\approx 10^{2}$ keV, we draw the
following conclusions. At distances $r\gtrsim 20$ pc from the center of the
lens the effect of the central object on the lensing properties is negligible.
However, we show that measurements of the deflection angle produced by the DM
distribution in the outer region at a few kpc, together with rotation curve
data, could help to discriminate between different DM models. We show that at
distances $\sim 10^{-4}$ pc strong lensing effects, such as multiple images and
Einstein rings, may occur. Large differences in the deflection angle produced
by a DM central core and a central BH appear at distances $r\lesssim 10^{-6}$
pc; in this regime the weak-field formalism is no longer applicable and the
exact general-relativistic formula has to be used. We find that quantum DM
cores do not show a photon sphere what implies that they do not cast a shadow.
Similar conclusions apply to the other DM distributions for other fermion
masses in the above specified range and for other galaxy types.


title: An Improved Filtering Algorithm for Big Read Datasets

abstract:
  For single-cell or metagenomic sequencing projects, it is necessary to
sequence with a very high mean coverage in order to make sure that all parts of
the sample DNA get covered by the reads produced. This leads to huge datasets
with lots of redundant data. A filtering of this data prior to assembly is
advisable. Titus Brown et al. (2012) presented the algorithm Diginorm for this
purpose, which filters reads based on the abundance of their $k$-mers. We
present Bignorm, a faster and quality-conscious read filtering algorithm. An
important new feature is the use of phred quality scores together with a
detailed analysis of the $k$-mer counts to decide which reads to keep. With
recommended parameters, in terms of median we remove 97.15% of the reads while
keeping the mean phred score of the filtered dataset high. Using the SDAdes
assembler, we produce assemblies of high quality from these filtered datasets
in a fraction of the time needed for an assembly from the datasets filtered
with Diginorm. We conclude that read filtering is a practical method for
reducing read data and for speeding up the assembly process. Our Bignorm
algorithm allows assemblies of competitive quality in comparison to Diginorm,
while being much faster. Bignorm is available for download at
https://git.informatik.uni-kiel.de/axw/Bignorm.git


title:
Observation of antiphase coherent phonons in the warped Dirac cone of
  Bi$_2$Te$_3$

abstract:
  In this Rapid Communication we investigate the coupling between excited
electrons and phonons in the highly anisotropic electronic structure of the
prototypical topological insulator Bi$_2$Te$_3$. Using time- and angle-resolved
photoemission spectroscopy we are able to identify the emergence and ultrafast
temporal evolution of the longitudinal-optical A$_{1g}$ coherent-phonon mode in
Bi$_2$Te$_3$. We observe an antiphase behavior in the onset of the
coherent-phonon oscillations between the $\overline{\Gamma K}$ and the
$\overline{\Gamma M}$ high-symmetry directions that is consistent with warping.
The qualitative agreement between our density-functional theory calculations
and the experimental results reveals the critical role of the anisotropic
coupling between Dirac fermions and phonon modes in the topological insulator
Bi$_2$Te$_3$.


title:
Magnetic gap opening in rhombohedral-stacked multilayer graphene from
  first principles

abstract:
  We investigate the occurrence of magnetic and charge density wave
instabilities in rhombohedral-stacked multilayer (three to eight layers)
graphene by first principles calculations including exact exchange. Neglecting
spin-polarization, an extremely flat surface band centered at the special point
${\bf K}$ of the Brillouin zone occurs at the Fermi level. Spin polarization
opens a gap in the surface state by stabilizing an antiferromagnetic state. The
top and the bottom surface layers are weakly ferrimagnetic in-plane (net
magnetization smaller than $10^{-3}\mu_B$), and are antiferromagnetic coupled
to each other. This coupling is propagated by the out-of-plane
antiferromagnetic coupling between the nearest neighbors. The gap is very small
in a spin-polarized generalized gradient approximation, while it is
proportional to the amount of exact exchange in hybrid functionals. For
trilayer rhombohedral graphene it is $38.6$ meV in PBE0, in agreement with the
$42$ meV gap found in experiments. We study the temperature and doping
dependence of the magnetic gap. At electron doping of $n \sim 7 \times 10^{11}$
cm$^{-2}$ the gap closes. Charge density wave instabilities with
$\sqrt{3}\times\sqrt{3}$ periodicity do not occur.


title:
Nonsmooth optimization using Taylor-like models: error bounds,
  convergence, and termination criteria

abstract:
  We consider optimization algorithms that successively minimize simple
Taylor-like models of the objective function. Methods of Gauss-Newton type for
minimizing the composition of a convex function and a smooth map are common
examples. Our main result is an explicit relationship between the step-size of
any such algorithm and the slope of the function at a nearby point.
Consequently, we (1) show that the step-sizes can be reliably used to terminate
the algorithm, (2) prove that as long as the step-sizes tend to zero, every
limit point of the iterates is stationary, and (3) show that conditions, akin
to classical quadratic growth, imply that the step-sizes linearly bound the
distance of the iterates to the solution set. The latter so-called error bound
property is typically used to establish linear (or faster) convergence
guarantees. Analogous results hold when the step-size is replaced by the square
root of the decrease in the model's value. We complete the paper with
extensions to when the models are minimized only inexactly.


title:
Optical, UV, and X-Ray Evidence for a 7-Year Stellar Cycle in Proxima
  Centauri

abstract:
  Stars of stellar type later than about M3.5 are believed to be fully
convective and therefore unable to support magnetic dynamos like the one that
produces the 11-year solar cycle. Because of their intrinsic faintness, very
few late M stars have undergone long-term monitoring to test this prediction,
which is critical to our understanding of magnetic field generation in such
stars. Magnetic activity is also of interest as the driver of UV and X-ray
radiation, as well as energetic particles and stellar winds, that affect the
atmospheres of close-in planets that lie within habitable zones, such as the
recently discovered Proxima b. We report here on several years of optical, UV,
and X-ray observations of Proxima Centauri (GJ 551; dM5.5e): 15 years of ASAS
photometry in the V band (1085 nights) and 3 years in the I band (196 nights),
4 years of Swift XRT and UVOT observations (more than 120 exposures), and 9
sets of X-ray observations from other X-ray missions (ASCA, XMM-Newton, and
three Chandra instruments) spanning 22 years. We confirm previous reports of an
83-day rotational period and find strong evidence for a 7-year stellar cycle,
along with indications of differential rotation at about the solar level.
X-ray/UV intensity is anti-correlated with optical V-band brightness for both
rotational and cyclical variations. From comparison with other stars observed
to have X-ray cycles we deduce a simple empirical relationship between X-ray
cyclic modulation and Rossby number, and we also present Swift UV grism spectra
covering 2300-6000 {\AA}.


title:
Some remarks on the classification of global solutions with
  asymptotically flat level sets

abstract:
  We simplify some technical steps from \cite{S1} in which a conjecture of De
Giorgi was addressed. For completeness we make the paper self-contained and
reprove the classification of certain global bounded solutions for semilinear
equations of the type $$\triangle u=W'(u),$$ where $W$ is a double well
potential.


title:
New classes of bi-axially symmetric solutions to four-dimensional
  Vasiliev higher spin gravity

abstract:
  We present new infinite-dimensional spaces of bi-axially symmetric
asymptotically anti-de Sitter solutions to four-dimensional Vasiliev higher
spin gravity, obtained by modifications of the Ansatz used in arXiv:1107.1217,
which gave rise to a Type-D solution space. The current Ansatz is based on
internal semigroup algebras (without identity) generated by exponentials formed
out of the bi-axial symmetry generators. After having switched on the vacuum
gauge function, the resulting generalized Weyl tensor is given by a sum of
generalized Petrov type-D tensors that are Kerr-like or 2-brane-like in the
asymptotic AdS4 region, and the twistor space connection is smooth in twistor
space over finite regions of spacetime. We provide evidence for that the
linearized twistor space connection can be brought to Vasiliev gauge.


title:
A Distributed Multi Agents Based Platform for High Performance Computing
  Infrastructures

abstract:
  This work introduces a novel, modular, layered web based platform for
managing machine learning experiments on grid-based High Performance Computing
infrastructures. The coupling of the communication services offered by the
grid, with an administration layer and conventional web server programming, via
a data synchronization utility, leads to the straightforward development of a
web-based user interface that allows the monitoring and managing of diverse
online distributed computing applications. It also introduces an experiment
generation and monitoring tool particularly suitable for investigating machine
learning in game playing. The platform is demonstrated with experiments for two
different games.


title:
Four-dimensional equation of motion for viscous compressible and charged
  fluid with regard to the acceleration field, pressure field and dissipation
  field

abstract:
  From the principle of least action the equation of motion for viscous
compressible and charged fluid is derived. The viscosity effect is described by
the 4-potential of the energy dissipation field, dissipation tensor and
dissipation stress-energy tensor. In the weak field limit it is shown that the
obtained equation is equivalent to the Navier-Stokes equation. The equation for
the power of the kinetic energy loss is provided, the equation of motion is
integrated, and the dependence of the velocity magnitude is determined. A
complete set of equations is presented, which suffices to solve the problem of
motion of viscous compressible and charged fluid in the gravitational and
electromagnetic fields.


title:
Kek, Cucks, and God Emperor Trump: A Measurement Study of 4chan's
  Politically Incorrect Forum and Its Effects on the Web

abstract:
  The discussion-board site 4chan has been part of the Internet's dark
underbelly since its inception, and recent political events have put it
increasingly in the spotlight. In particular, /pol/, the "Politically
Incorrect" board, has been a central figure in the outlandish 2016 US election
season, as it has often been linked to the alt-right movement and its rhetoric
of hate and racism. However, 4chan remains relatively unstudied by the
scientific community: little is known about its user base, the content it
generates, and how it affects other parts of the Web. In this paper, we start
addressing this gap by analyzing /pol/ along several axes, using a dataset of
over 8M posts we collected over two and a half months. First, we perform a
general characterization, showing that /pol/ users are well distributed around
the world and that 4chan's unique features encourage fresh discussions. We also
analyze content, finding, for instance, that YouTube links and hate speech are
predominant on /pol/. Overall, our analysis not only provides the first
measurement study of /pol/, but also insight into online harassment and hate
speech trends in social media.


title:
High Energy QCD at NLO: from light-cone wave function to JIMWLK
  evolution

abstract:
  Soft components of the light cone wave-function of a fast moving projectile
hadron is computed in perturbation theory to third order in QCD coupling
constant. At this order, the Fock space of the soft modes consists of
one-gluon, two-gluon, and a quark-antiquark states. The hard component of the
wave-function acts as a non-Abelian background field for the soft modes and is
represented by a valence charge distribution that accounts for non-linear
density effects in the projectile. When scattered off a dense target, the
diagonal element of the S-matrix reveals the Hamiltonian of high energy
evolution, the JIMWLK Hamiltonian. This way we provide a new direct derivation
of the JIMWLK Hamiltonian at the Next-to-Leading Order.


title: Deep Variational Canonical Correlation Analysis

abstract:
  We present deep variational canonical correlation analysis (VCCA), a deep
multi-view learning model that extends the latent variable model interpretation
of linear CCA to nonlinear observation models parameterized by deep neural
networks. We derive variational lower bounds of the data likelihood by
parameterizing the posterior probability of the latent variables from the view
that is available at test time. We also propose a variant of VCCA called
VCCA-private that can, in addition to the "common variables" underlying both
views, extract the "private variables" within each view, and disentangles the
shared and private information for multi-view data without hard supervision.
Experimental results on real-world datasets show that our methods are
competitive across domains.


title: On deformations of toric varieties

abstract:
  Let X be a smooth complete toric variety. We describe the
Altmann-Ilten-Vollmert equivariant deformations of toric varieties in the
language of Cox rings. More precisely we construct one parameters families of
deformations of X, such that the total space of the deformation is a T-variety
of complexity one defined by a trinomial equation, and the deformation map is
equivariant with respect to the torus action. Moreover we show that the images
of all these families via the Kodaira-Spencer map form a basis of the vector
space H1(X,T_X).


title:
Tangent cones to generalised theta divisors and generic injectivity of
  the theta map

abstract:
  Let $C$ be a Petri general curve of genus $g$ and $E$ a general stable vector
bundle of rank $r$ and slope $g-1$ over $C$ with $h^0 (C, E) = r+1$. For $g >
(2r+2)(2r+1)$, we show how the bundle $E$ can be recovered from the tangent
cone to the theta divisor $\Theta_E$ at ${\mathcal O}_C$. We use this to give a
constructive proof and a sharpening of Brivio and Verra's theorem that the
theta map $SU_C (r) -rightarrow |r \Theta|$ is generically injective for large
values of $g$.


title:
A finite volume/discontinuous Galerkin method for the advective
  Cahn-Hilliard equation with degenerate mobility on porous domains stemming
  from micro-CT imaging

abstract:
  A numerical method is formulated for the solution of the advective
Cahn-Hilliard (CH) equation with constant and degenerate mobility in
three-dimensional porous media with non-vanishing velocity on the exterior
boundary. The CH equation describes phase separation of an immiscible binary
mixture at constant temperature in the presence of a mass constraint and
dissipation of free energy. Porous media/pore-scale problems specifically
entail high-resolution images of rocks in which the solid matrix and pore
spaces are fully resolved. The interior penalty discontinuous Galerkin method
is used for the spatial discretization of the CH equation in mixed form, while
a semi-implicit convex-concave splitting is utilized for temporal
discretization. The spatial approximation order is arbitrary, while it reduces
to a finite volume scheme for the choice of elementwise constants. The
resulting nonlinear systems of equations are reduced using the Schur complement
and solved via Newton's method. The numerical scheme is first validated using
numerical convergence tests and then applied to a number of fundamental
problems for validation and numerical experimentation purposes including the
case of degenerate mobility. First-order physical applicability and robustness
of the numerical method are shown in a breakthrough scenario on a voxel set
obtained from a micro-CT scan of a real sandstone rock sample.


title: Sampling errors of quantile estimations from finite samples of data

abstract:
  Empirical relationships are derived for the expected sampling error of
quantile estimations using Monte Carlo experiments for two frequency
distributions frequently encountered in climate sciences. The relationships
found are expressed as a scaling factor times the standard error of the mean;
these give a quick tool to estimate the uncertainty of quantiles for a given
finite sample size.


title:
Magnetic concentrations in stratified turbulence: the negative effective
  magnetic pressure instability

abstract:
  In the presence of strong density stratification, hydromagnetic turbulence
attains qualitatively new properties: the formation of magnetic flux
concentrations. We review here the theoretical foundations of this mechanism in
terms of what is now called the negative effective magnetic pressure
instability. We also present direct numerical simulations of forced turbulence
in strongly stratified layers and discuss the qualitative and quantitative
similarities with corresponding mean-field simulations. Finally, the relevance
to sunspot formation is discussed.


title: Formation and composition of planets around very low mass stars

abstract:
  The recent detection of planets around very low mass stars raises the
question of the formation, composition and potential habitability of these
objects. We use planetary system formation models to infer the properties, in
particular their radius distribution and water content, of planets that may
form around stars ten times less massive than the Sun. Our planetary system
formation and composition models take into account the structure and evolution
of the protoplanetary disk, the planetary mass growth by accretion of solids
and gas, as well as planet-planet, planet-star and planet-disk interactions. We
show that planets can form at small orbital period in orbit about low mass
stars. We show that the radius of the planets is peaked at about 1 rearth and
that they are, in general, volatile rich especially if proto-planetary discs
orbiting this type of stars are long-lived. Close-in planets orbiting low-mass
stars similar in terms of mass and radius to the ones recently detected can be
formed within the framework of the core accretion paradigm as modeled here. The
properties of protoplanetary disks, and their correlation with the stellar
type, are key to understand their composition.


title: On break-away forces in actuated motion systems with nonlinear friction

abstract:
  The phenomenon of so-called break-away forces, as maximal actuation forces at
which a sticking system begins to slide and thus passes over to a steady
(macro) motion, is well known from engineering practice but still less
understood in its cause-effect relationship. This note analyzes the break-away
behavior of systems with nonlinear friction, which is analytically
well-described by combining the Coulomb friction law with rate-independent
presliding transitions and, when necessary, Stribeck effect of the
velocity-weakening steady-state curve. The break-away conditions are harmonized
with analytic form of the system description and shown to be in accord with a
relationship between the varying break-away force and actuation force rate --
well known from the experiments reported in several independently published
works.


title: $(\alpha,\beta)$-A-Normal Operators in Semi-Hilbertian Spaces

abstract:
  In this paper we introduce and prove some properties of
$(\alpha;\beta)$-normal operators according to semi-Hilbertian space
structures. Furthermore we s,ate various inequalities between the A-operator
norm and A-numerical radius of $(\alpha,\beta)$-normal operators in semi
Hilbertian spaces.


title: The BV formalism: theory and application to a matrix model

abstract:
  We review the BV formalism in the context of $0$-dimensional gauge theories.
For a gauge theory $(X_{0}, S_{0})$ with an affine configuration space $X_{0}$,
we describe an algorithm to construct a corresponding extended theory
$(\tilde{X}, \tilde{S})$, obtained by introducing ghost and anti-ghost fields,
with $\tilde{S}$ a solution of the classical master equation in
$\mathcal{O}_{\tilde{X}}$. This construction is the first step to define the
(gauge-fixed) BRST cohomology complex associated to $(\tilde{X}, \tilde{S})$,
which encodes many interesting information on the initial gauge theory $(X_{0},
S_{0})$. The second part of this article is devoted to the application of this
method to a matrix model endowed with a $U(2)$-gauge symmetry, explicitly
determining the corresponding $\tilde{X}$ and the general solution $\tilde{S}$
of the classical master equation for the model.


title: Oblique Collisions of Baseballs and Softballs with a Bat

abstract:
  Experiments are done by colliding a swinging bat with a stationary baseball
or softball. Each collision was recorded with high-speed cameras, from which
the post-impact speed, launch angle, and spin of the ball could be determined.
Initial bat speeds were in the range 63-88 mph, producing launch angles in the
range 0$^\circ$-30$^\circ$ and spins in the range 0-3500 rpm. The results are
analyzed in the context of a ball-bat collision model and the parameters of
that model are determined. For both baseballs and softballs, the data are
consistent with a mechanism whereby the ball grips the surface of the bat,
stretching the ball in the transverse direction and resulting in a spin that
was up to 40$\%$ greater than would be obtained by rolling contact of rigid
bodies. Using a lumped parameter contact model, baseballs are shown to be less
compliant tangentially than softballs. Implications of our results for batted
balls in game situations are presented.