title:
Generation of higher dimensional entangled states in quantum Rabi
  systems

abstract:
  We present protocols for the generation of high-dimensional entangled states
of anharmonic oscillators by means of coherent manipulation of light-matter
systems in the ultrastrong coupling regime. Our protocols consider a pair of
ultrastrong coupled qubit-cavity systems, each coupled to an ancilla qubit, and
combine classical pulses plus the selection rules imposed by the parity
symmetry. We study the robustness of the entangling protocols under dissipative
effects. This proposal may have applications within state-of-art circuit
quantum electrodynamics.


title: Poisson Random Fields for Dynamic Feature Models

abstract:
  We present the Wright-Fisher Indian buffet process (WF-IBP), a probabilistic
model for time-dependent data assumed to have been generated by an unknown
number of latent features. This model is suitable as a prior in Bayesian
nonparametric feature allocation models in which the features underlying the
observed data exhibit a dependency structure over time. More specifically, we
establish a new framework for generating dependent Indian buffet processes,
where the Poisson random field model from population genetics is used as a way
of constructing dependent beta processes. Inference in the model is complex,
and we describe a sophisticated Markov Chain Monte Carlo algorithm for exact
posterior simulation. We apply our construction to develop a nonparametric
focused topic model for collections of time-stamped text documents and test it
on the full corpus of NIPS papers published from 1987 to 2015.


title:
Starspot signature on the light curve: Learning about the latitudinal
  distribution of spots

abstract:
  Quasi-periodic modulations of the stellar light curve may result from dark
spots crossing the visible stellar disc. Due to differential rotation, spots at
different latitudes generally have different rotation periods. Hence, by
studying spot-induced modulations, one can learn about stellar surface
(differential) rotation and magnetic activity. Recently, Reinhold & Arlt (2015)
proposed a method based on the Lomb-Scargle periodogram of light curves to
identify the sign of the differential rotation at the stellar surface. Our goal
is to understand how the modulation of the stellar light curve due to the
presence of spots and the corresponding periodogram are affected by both the
stellar and spot properties. We generate synthetic light curves of stars with
different properties (inclination angle, limb darkening, and rotation rate) and
spot configurations (number of spots, latitude, intensity contrast, and size).
By analysing their Lomb-Scargle periodograms, we compute the ratio between the
heights of the second and first harmonics of the rotation period
(peak-height-ratio). We find that the peak-height ratios are essentially a
function of a single parameter, the fraction of time the spot is visible, which
is related to the sinusoidality of the spot modulation. We identify the
conditions under which the periodogram analysis can actually provide an
estimate of the spot latitudes and/or the stellar inclination angle. We also
identify possible sources of error in the identification of the sign of the
differential rotation.


title: Graphs, friends and acquaintances

abstract:
  As is well known, a graph is a mathematical object modeling the existence of
a certain relation between pairs of elements of a given set. Therefore, it is
not surprising that many of the first results concerning graphs made reference
to relationships between people or groups of people. In this article, we
comment on four results of this kind, which are related to various general
theories on graphs and their applications: the Handshake lemma (related to
graph colorings and Boolean algebra), a lemma on known and unknown people at a
cocktail party (to Ramsey theory), a theorem on friends in common (to
distance-regularity and coding theory), and Hall's Marriage theorem (to the
theory of networks). These four areas of graph theory, often with problems
which are easy to state but difficult to solve, are extensively developed and
currently give rise to much research work. As examples of representative
problems and results of these areas, which are discussed in this paper, we may
cite the following: the Four Colors Theorem (4CTC), the Ramsey numbers,
problems of the existence of distance-regular graphs and completely regular
codes, and finally the study of topological proprieties of interconnection
networks.


title: Scl in free products

abstract:
  We study stable commutator length (scl) in free products via surface maps
into a wedge of spaces. We prove that scl is piecewise rational linear if it
vanishes on each factor of the free product, generalizing the main result in
Danny Calegari's paper "Scl, sails and surgery". We further prove that the
property of isometric embedding with respect to scl is preserved under taking
free products. The method of proof gives a way to compute scl in free products
which lets us generalize and derive in a new way several well-known formulas.
Finally we show independently and in a new approach that scl in free products
of cyclic groups behaves in a piecewise quasi-rational way when the word is
fixed but the orders of factors vary, previously proved by Timothy Susse,
settling a conjecture of Alden Walker.


title:
Learning about the latitudinal distribution of starspots through the
  periodogram analysis of photometric data

abstract:
  Starspots are cooler and darker than the stellar surface. Therefore, the
emitted flux of a star changes when spots are visible on its surface. The
presence of spots together with the stellar rotation leads to a periodic
modulation on the light curve. By studying that modulation one can then learn
about the stellar rotation and also magnetic activity. Recently, Reinhold &
Arlt (2015) proposed a method based on the analysis of the Lomb Scargle
periodogram of the light curve to identify the sign of the differential
rotation, i.e. whether the equator rotates faster than the poles or the
opposite. We have been studying in detail the spots' impact on the light curve
and on the resulting periodogram. We find that, under some conditions, the
periodogram can actually provide an estimate of the true spot latitudes and/or
the stellar inclination angle. Moreover, we find that the impact of the spot on
the ratio between the heights of the second and first harmonics of the main
peaks in the periodogram can be described by a single parameter, the visibility
time of the spot. Finally, we also identify possible sources of false
positives/negatives for the sign of the differential rotation.


title: Growth of EuO single crystals at reduced temperatures

abstract:
  Single crystals of (Eu$_{1-x}$Ba$_x$)O have been grown in a molten
barium-magnesium metal flux at temperatures up to 1000{\deg}C, producing single
crystals of (Eu$_{1-x}$Ba$_x$)O with barium doping levels ranging from $x=0.03$
to $x=0.25$. Magnetic measurements show that the ferromagnetic Curie
temperature T$_C$ correlates with the Ba doping levels, and a modified
Heisenberg model was used to describe the stoichiometry dependence of T$_C$.
Extrapolation of the results indicates that a sample with Ba concentration of
$x=0.72$ should have a T$_C$ of 0 K, potentially producing a quantum phase
transition in this material.


title: Depth of vertices with high degree in random recursive trees

abstract:
  Let $T_n$ be a random recursive tree with $n$ nodes. List vertices of $T_n$
in decreasing order of degree as $v^1,\ldots,v^n$, and write $d^i$ and $h^i$
for the degree of $v^i$ and the distance of $v^i$ from the root, respectively.
We prove that, as $n \to \infty$ along suitable subsequences, \[ \bigg(d^i -
\lfloor \log_2 n \rfloor, \frac{h^i - \mu\ln n}{\sqrt{\sigma^2\ln n}}\bigg) \to
((P_i,i \ge 1),(N_i,i \ge 1))\, , \] where $\mu=1-(\log_2 e)/2$,
$\sigma^2=1-(\log_2 e)/4$, $(P_i,i \ge 1)$ is a Poisson point process on
$\mathbb{Z}$ and $(N_i,i \ge 1)$ is a vector of independent standard Gaussians.
We additionally establish joint normality for the depths of uniformly random
vertices in $T_n$, which extends results for the case of a single random
vertex. The joint limit holds even if the random vertices are conditioned to
have large degree, provided the normalizing constants are adjusted accordingly;
however, both the mean and variance of the conditinal depths remain of orden
$\ln n$.
  Our results are based on a simple relationship between random recursive trees
and Kingman's $n$-coalescent; a utility that seems to have been largely
overlooked.


title: Finiteness conditions for the non-abelian tensor product of groups

abstract:
  Let $G$, $H$ be groups. We denote by $\eta(G,H)$ a certain extension of the
non-abelian tensor product $G \otimes H$ by $G \times H$. We prove that if $G$
and $H$ are groups that act compatibly on each other and such that the set of
all tensors $T_{\otimes}(G,H)=\{g\otimes h \, : \, g \in G, \, h\in H\}$ is
finite, then the non-abelian tensor product $G \otimes H$ is finite. In the
opposite direction we examine certain finiteness conditions of $G$ in terms of
similar conditions for the tensor square $G \otimes G$.


title: F-Index of Four Operations on Graphs

abstract:
  The F-index of a graph is defined as the sum of cubes of the vertex degrees
of the graph which was introduced in 1972, in the same paper where the first
and second Zagreb indices were introduced. In this paper we study the F-index
of four operations on graphs which were introduced by Eliasi and Taeri [M.
Eliasi, B. Taeri, Four new sums of graphs and their Wiener indices,
\textit{Discrete Appl. Math.}\textbf{157}(2009) 794--803.].


title: Fast Measurements of Robustness to Changing Priors in Variational Bayes

abstract:
  In Bayesian analysis, the posterior follows from the data and a choice of a
prior and a likelihood. One hopes that the posterior is robust to reasonable
variation in the choice of prior, since this choice is made by the modeler and
is often somewhat subjective. A different, equally subjectively plausible
choice of prior may result in a substantially different posterior, and so
different conclusions drawn from the data. Were this to be the case, our
conclusions would not be robust to the choice of prior. To determine whether
our model is robust, we must quantify how sensitive our posterior is to
perturbations of our prior. Despite the importance of the problem and a
considerable body of literature, generic, easy-to-use methods to quantify
Bayesian robustness are still lacking.
  Abstract In this paper, we demonstrate that powerful measures of robustness
can be easily calculated from Variational Bayes (VB) approximate posteriors. We
begin with local robustness, which measures the effect of infinitesimal changes
to the prior on a posterior mean of interest. In particular, we show that the
influence function of Gustafson (2012) has a simple, easy-to-calculate closed
form expression for VB approximations. We then demonstrate how local robustness
measures can be inadequate for non-local prior changes, such as replacing one
prior entirely with another. We propose a simple approximate non-local
robustness measure and demonstrate its effectiveness on a simulated data set.


title:
Herschel / HIFI spectral line survey of the Orion Bar - Temperature and
  density differentiation near the PDR surface

abstract:
  Photon Dominated Regions (PDRs) are interfaces between the mainly ionized and
mainly molecular material around young massive stars. Analysis of the physical
and chemical structure of such regions traces the impact of far-ultraviolet
radiation of young massive stars on their environment. We present results on
the physical and chemical structure of the prototypical high UV-illumination
edge-on Orion Bar PDR from an unbiased spectral line survey with a wide
spectral coverage. A spectral scan from 480-1250 GHz and 1410-1910 GHz at 1.1
MHz resolution was obtained by the HIFI instrument onboard the Herschel Space
Observatory. For molecules with multiple transitions we used rotational
diagrams to obtain excitation temperatures and column densities. For species
with a single detected transition we used an optically thin LTE approximation.
In case of species with available collisional rates, we also performed a
non-LTE analysis to obtain kinetic temperatures, H2 volume densities, and
column densities. About 120 lines corresponding to 29 molecules (including
isotopologues) have been detected in the Herschel/HIFI line survey, including
11 transitions of CO, 7 transitions of 13CO, 6 transitions of C18O, 10
transitions of H2CO, and 6 transitions of H2O. Most species trace kinetic
temperatures in the range between 100 and 150 K and H2 volume densities in the
range between 10^5 and 10^6 cm^-3. The species with temperatures and / or
densities outside of this range include the H2CO transitions tracing a very
high temperature (315 K) and density (1.4x10^6 cm^-3) component and SO
corresponding to the lowest temperature (56 K) measured as a part of this line
survey. The observed lines/species reveal a range of physical conditions (gas
density /temperature) involving structures at high density / high pressure,
obsoleting the traditional 'clump / interclump' picture of the Orion Bar.


title: Distinguished models of intermediate Jacobians

abstract:
  We show that the image of the Abel-Jacobi map admits functorially a model
over the field of definition, with the property that the Abel-Jacobi map is
equivariant with respect to this model. The cohomology of this abelian variety
over the base field is isomorphic as a Galois representation to the deepest
part of the coniveau filtration of the cohomology of the projective variety.
Moreover, we show that this model over the base field is dominated by the
Albanese variety of a product of components of the Hilbert scheme of the
projective variety, and thus we answer a question of Mazur. We also recover a
result of Deligne on complete intersections of Hodge level one.


title: QCD, with Strings Attached

abstract:
  In the nearly twenty years that have elapsed since its discovery, the
gauge-gravity correspondence has become established as an efficient tool to
explore the physics of a large class of strongly-coupled field theories. A
brief overview is given here of its formulation and a few of its applications,
emphasizing attempts to emulate aspects of the strong-coupling regime of
quantum chromodynamics (QCD). To the extent possible, the presentation is
self-contained, and in particular, it does not presuppose knowledge of string
theory.


title:
On the Cauchy problem with large data for a space-dependent
  Boltzmann-Nordheim boson equation II

abstract:
  This paper studies a space-inhomogeneous Boltzmann-Nordheim equation with
pseudo-Maxwellian forces. Strong solutions are obtained for the Cauchy problem
in a setting with large bounded L1 initial data. The main results are
existence, uniqueness, stability and qualitative boundedness features for
solutions conserving mass, momentum and energy.


title:
Kazhdan-Lusztig polynomials of matroids: a survey of results and
  conjectures

abstract:
  We report on various results, conjectures, and open problems related to
Kazhdan-Lusztig polynomials of matroids. We focus on conjectures about the
roots of these polynomials, all of which appear here for the first time.


title:
On the relation between activity-related frequency shifts and the
  sunspot distribution over the solar cycle 23

abstract:
  The activity-related variations in the solar acoustic frequencies have been
known for 30 years. However, the importance of the different contributions is
still not well established. With this in mind, we developed an empirical model
to estimate the spot-induced frequency shifts, which takes into account the
sunspot properties, such as area and latitude. The comparison between the model
frequency shifts obtained from the daily sunspot records and those observed
suggests that the contribution from a stochastic component to the total
frequency shifts is about 30%. The remaining 70% is related to a global,
long-term variation. We also propose a new observable to investigate the short-
and mid-term variations of the frequency shifts, which is insensitive to the
long-term variations contained in the data. On the shortest time scales the
variations in the frequency shifts are strongly correlated with the variations
in the total area covered by sunspots. However, a significant loss of
correlation is still found, which cannot be fully explained by ignoring the
invisible side of the Sun when accounting for the total sunspot area. We also
verify that the times when the frequency shifts and the sunspot areas do not
vary in a similar way tend to coincide with the times of the maximum amplitude
of the quasi-biennial variations found in the seismic data.


title: Eigenvalues of the Hessian in Deep Learning: Singularity and Beyond

abstract:
  We look at the eigenvalues of the Hessian of a loss function before and after
training. The eigenvalue distribution is seen to be composed of two parts, the
bulk which is concentrated around zero, and the edges which are scattered away
from zero. We present empirical evidence for the bulk indicating how
over-parametrized the system is, and for the edges that depend on the input
data.


title: Thermalization of Fermionic Quantum Walkers

abstract:
  We consider the discrete time dynamics of an ensemble of fermionic quantum
walkers moving on a finite discrete sample, interacting with a reservoir of
infinitely many quantum particles on the one dimensional lattice. The reservoir
is given by a fermionic quasifree state, with free discrete dynamics given by
the shift, whereas the free dynamics of the non-interacting quantum walkers in
the sample is defined by means of a unitary matrix. The reservoir and the
sample exchange particles at specific sites by a unitary coupling and we study
the discrete dynamics of the coupled system defined by the iteration of the
free discrete dynamics acting on the unitary coupling, in a variety of
situations. In particular, in absence of correlation within the particles of
the reservoir and under natural assumptions on the sample's dynamics, we prove
that the one- and two-body reduced density matrices of the sample admit large
times limits characterized by the state of the reservoir which are independent
of the free dynamics of the quantum walkers and of the coupling strength.
Moreover, the corresponding asymptotic density profile in the sample is flat
and the correlations of number operators have no structure, a manifestation of
thermalization.


title: An unexpected unity among methods for interpreting model predictions

abstract:
  Understanding why a model made a certain prediction is crucial in many data
science fields. Interpretable predictions engender appropriate trust and
provide insight into how the model may be improved. However, with large modern
datasets the best accuracy is often achieved by complex models even experts
struggle to interpret, which creates a tension between accuracy and
interpretability. Recently, several methods have been proposed for interpreting
predictions from complex models by estimating the importance of input features.
Here, we present how a model-agnostic additive representation of the importance
of input features unifies current methods. This representation is optimal, in
the sense that it is the only set of additive values that satisfies important
properties. We show how we can leverage these properties to create novel visual
explanations of model predictions. The thread of unity that this representation
weaves through the literature indicates that there are common principles to be
learned about the interpretation of model predictions that apply in many
scenarios.


title: Leading order multi-soft behaviors of tree amplitudes in NLSM

abstract:
  In this paper, we investigate multi-soft behaviors of tree amplitudes in
nonlinear sigma model (NLSM). The leading behaviors of amplitudes with odd
number of all-adjacent soft pions are zero. We further propose and prove that
leading soft factors of amplitudes with even number all-adjacent soft pions can
be expressed in terms of products of the leading order Berends-Giele
sub-currents in Cayley parametrization. Each sub-current in the expression
contains at most one hard pion. Discussions are generalized to amplitudes
containing arbitrary number of nonadjacent soft blocks: The leading behaviors
of amplitudes where at least one soft block has odd number of adjacent soft
pions are zero; The leading soft factors for amplitudes where all soft blocks
containing even number of soft pions are given by products of soft factors for
these blocks.


title: Recent Results of Electron-Neutrino Appearance Measurement at NOvA

abstract:
  NOvA is a long-baseline accelerator-based neutrino oscillation experiment
that is optimized for $\nu_e$ measurements. It uses the upgraded NuMI beam from
Fermilab and measures electron-neutrino appearance and muon-neutrino
disappearance at its Far Detector in Ash River, Minnesota. The $\nu_e$
appearance analysis at NOvA aims to resolve the neutrino mass hierarchy problem
and to constrain the CP-violating phase. The first measurement of
electron-neutrino appearance in NOvA based on its first year's data was
produced in 2015, providing solid evidence of $\nu_e$ oscillation with the NuMI
beam line and some hints on mass-hierarchy and CP. This talk will discuss the
second $\nu_e$ oscillation analysis at NOvA, which is based on 2 years of data.


title:
PyCDT: A Python toolkit for modeling point defects in semiconductors and
  insulators

abstract:
  Point defects have a strong impact on the performance of semiconductor and
insulator materials used in technological applications, spanning
microelectronics to energy conversion and storage. The nature of the dominant
defect types, how they vary with processing conditions, and their impact on
materials properties are central aspects that determine the performance of a
material in a certain application. This information is, however, difficult to
access directly from experimental measurements. Consequently, computational
methods, based on electronic density functional theory (DFT), have found
widespread use in the calculation of point-defect properties. Here we have
developed the Python Charged Defect Toolkit (PyCDT) to expedite the setup and
post-processing of defect calculations with widely used DFT software. PyCDT has
a user-friendly command-line interface and provides a direct interface with the
Materials Project database. This allows for setting up many charged defect
calculations for any material of interest, as well as post-processing and
applying state-of-the-art electrostatic correction terms. Our paper serves as a
documentation for PyCDT, and demonstrates its use in an application to the
well-studied GaAs compound semiconductor. We anticipate that the PyCDT code
will be useful as a framework for undertaking readily reproducible calculations
of charged point-defect properties, and that it will provide a foundation for
automated, high-throughput calculations.


title:
Electric-field Induced Reversible Switching of the Magnetic Easy-axis in
  Co/BiFeO3/SrRuO3/SrTiO3 Heterostructures

abstract:
  Electric-field (E-field) control of magnetism enabled by multiferroics has
the potential to revolutionize the landscape of present memory devices plagued
with high energy dissipation. To date, this E-field controlled multiferroic
scheme at room temperature has only been demonstrated using BiFeO3 (BFO) films
grown on DyScO3 (refs 1 and 2), a unique and expensive substrate, which gives
rise to a particular ferroelectric domain pattern in BFO. Here, we demonstrate
reversible E-field-induced switching of the magnetic state of the Co layer in
Co/BFO (001) thin film heterostructures fabricated on SrTiO3 substrates. The
angular dependence of the coercivity and the remanent magnetization of the Co
layer indicates that its easy axis reversibly switches by 45{\deg} back and
forth between the (100) and the (110) crystallographic directions of SrTiO3 as
a result of alternating application of positive and negative voltage pulses on
BFO. The coercivity of the Co layer exhibits a hysteretic behavior between two
states as a function of voltage. To explain the observation, we have also
measured the exact canting angle of the antiferromagnetic G-type domain in BFO
films for the first time using neutron diffraction. These results suggest a
pathway to integrating BFO-based devices on Si wafers for implementing low
power consumption and non-volatile magnetoelectronic devices.


title:
Monte Carlo study of particle production in diffractive proton-proton
  collisions at $\sqrt s$ = 13 TeV with the very forward detector combined with
  central information

abstract:
  Very forward (VF) detectors in hadron colliders, having unique sensitivity to
diffractive processes, can be a powerful tool for studying diffractive
dissociation by combining them with central detectors. Several Monte Carlo
simulation samples in $p$-$p$ collisions at $\sqrt s = 13$ TeV were analyzed,
and different nondiffractive and diffractive contributions were clarified
through differential cross sections of forward neutral particles. Diffraction
selection criteria in the VF-triggered-event samples were determined by using
the central track information. The corresponding selection applicable in real
experiments has $\approx$100% purity and 30%-70% efficiency. Consequently, the
central information enables classification of the forward productions into
diffraction and nondiffraction categories; in particular, most of the surviving
events from the selection belong to low-mass diffraction events at
$\log_{10}(\xi_{x}) < -5.5$. Therefore, the combined method can uniquely access
the low-mass diffraction regime experimentally.


title:
Creating photon-number squeezed strong microwave fields by a Cooper-pair
  injection laser

abstract:
  The use of artificial atoms as an active lasing medium opens a way to
construct novel sources of nonclassical radiation. An example is the creation
of photon-number squeezed light. Here we present a design of a laser consisting
of multiple Cooper-pair transistors coupled to a microwave resonator. Over a
broad range of experimentally realizable parameters, this laser creates
photon-number squeezed microwave radiation, characterized by a Fano factor $F
\ll 1$, at a very high resonator photon number. We investigate the impact of
gate-charge disorder in a Cooper-pair transistor and show that the system can
create squeezed strong microwave fields even in the presence of maximum
disorder.


title:
Scene Labeling using Gated Recurrent Units with Explicit Long Range
  Conditioning

abstract:
  Recurrent neural network (RNN), as a powerful contextual dependency modeling
framework, has been widely applied to scene labeling problems. However, this
work shows that directly applying traditional RNN architectures, which unfolds
a 2D lattice grid into a sequence, is not sufficient to model structure
dependencies in images due to the "impact vanishing" problem. First, we give an
empirical analysis about the "impact vanishing" problem. Then, a new RNN unit
named Recurrent Neural Network with explicit long range conditioning (RNN-ELC)
is designed to alleviate this problem. A novel neural network architecture is
built for scene labeling tasks where one of the variants of the new RNN unit,
Gated Recurrent Unit with Explicit Long-range Conditioning (GRU-ELC), is used
to model multi scale contextual dependencies in images. We validate the use of
GRU-ELC units with state-of-the-art performance on three standard scene
labeling datasets. Comprehensive experiments demonstrate that the new GRU-ELC
unit benefits scene labeling problem a lot as it can encode longer contextual
dependencies in images more effectively than traditional RNN units.


title: Locally self-avoiding eulerian tours

abstract:
  It was independently conjectured by H\"aggkvist in 1989 and Kriesell in 2011
that given a positive integer $\ell$, every simple eulerian graph with high
minimum degree (depending on $\ell$) admits an eulerian tour such that every
segment of length at most $\ell$ of the tour is a path. Bensmail, Harutyunyan,
Le and Thomass\'e recently verified the conjecture for 4-edge-connected
eulerian graphs. Building on that proof, we prove here the full statement of
the conjecture. This implies a variant of the path case of Bar\'at-Thomassen
conjecture that any simple eulerian graph with high minimum degree can be
decomposed into paths of fixed length and possibly an additional shorter path.


title: Center manifolds without a phase space

abstract:
  We establish center manifold theorems that allow one to study the bifurcation
of small solutions from a trivial state in systems of functional equations
posed on the real line. The class of equations includes most importantly
nonlinear equations with nonlocal coupling through convolution operators as
they arise in the description of spatially extended dynamics in neuroscience.
These systems possess a natural spatial translation symmetry but local
existence or uniqueness theorems for a spatial evolution associated with this
spatial shift or even a well motivated choice of phase space for the induced
dynamics do not seem to be available, due to the infinite range forward- and
backward-coupling through nonlocal convolution operators. We perform a
reduction relying entirely on functional analytic methods. Despite the nonlocal
nature of the problem, we do recover a local differential equation describing
the dynamics on the set of small bounded solutions, exploiting that the
translation invariance of the original problem induces a flow action on the
center manifold. We apply our reduction procedure to problems in mathematical
neuroscience, illustrating in particular the new type of algebra necessary for
the computation of Taylor jets of reduced vector fields.


title:
Effective Superpotential and the Renormalization Group Equation in a
  Supersymmetric Chern-Simons-Matter Model in the Superfield Formalism

abstract:
  We studied the Dynamical Symmetry Breaking (DSB) mechanism in a
supersymmetric Chern-Simons theory in $\left(2+1\right)$ dimensions coupled to
$N$ matter superfields in the superfield formalism. For this purpose, we
developed a mechanism to calculate the effective superpotencial
$K_{\mathrm{eff}}\left(\sigma_{\mathrm{cl}},\alpha\right)$, where
$\sigma_{\mathrm{cl}}$ is a background superfield, and $\alpha$ a gauge-fixing
parameter that is introduced in the quantization process. The possible
dependence of the effective potential on the gauge parameter have been studied
in the context of quantum field theory. We developed the formalism of the
Nielsen identities in the superfield language, which is the appropriate
formalism to study DSB when the effective potential is gauge dependent. We also
discuss how to calculate the effective superpotential via the Renormalization
Group Equation (RGE) from the knowledge of the renormalization group functions
of the theory, i.e., $\beta$ functions and anomalous dimensions $\gamma$. We
perform a detailed calculation of these functions at two loops, finding that
these do not depend on $\alpha$, and therefore, by using the RGE, we calculate
the effective superpotencial $K_{\mathrm{eff}}$, showing that it is also
independent of $\alpha$. Then we discuss the improvement of the calculation of
$K_{\mathrm{eff}}$ by summing up leading logarithms, and we compare this
improvement with the one obtained in the non supersymmetric version of the
model. Finally, we study the DSB finding that it is operational for all
reasonable values of the free parameters, while the improvement obtained from
the RGE in general only produces a small quantitative correction in the
results, instead of the more dramatic qualitative change found in non
supersymmetric models.


title:
Approximating k-Forest with Resource Augmentation: A Primal-Dual
  Approach

abstract:
  In this paper, we study the $k$-forest problem in the model of resource
augmentation. In the $k$-forest problem, given an edge-weighted graph $G(V,E)$,
a parameter $k$, and a set of $m$ demand pairs $\subseteq V \times V$, the
objective is to construct a minimum-cost subgraph that connects at least $k$
demands. The problem is hard to approximate---the best-known approximation
ratio is $O(\min\{\sqrt{n}, \sqrt{k}\})$. Furthermore, $k$-forest is as hard to
approximate as the notoriously-hard densest $k$-subgraph problem.
  While the $k$-forest problem is hard to approximate in the worst-case, we
show that with the use of resource augmentation, we can efficiently approximate
it up to a constant factor.
  First, we restate the problem in terms of the number of demands that are {\em
not} connected. In particular, the objective of the $k$-forest problem can be
viewed as to remove at most $m-k$ demands and find a minimum-cost subgraph that
connects the remaining demands. We use this perspective of the problem to
explain the performance of our algorithm (in terms of the augmentation) in a
more intuitive way.
  Specifically, we present a polynomial-time algorithm for the $k$-forest
problem that, for every $\epsilon>0$, removes at most $m-k$ demands and has
cost no more than $O(1/\epsilon^{2})$ times the cost of an optimal algorithm
that removes at most $(1-\epsilon)(m-k)$ demands.


title: Can Co-robots Learn to Teach?

abstract:
  We explore beyond existing work on learning from demonstration by asking the
question: Can robots learn to teach?, that is, can a robot autonomously learn
an instructional policy from expert demonstration and use it to instruct or
collaborate with humans in executing complex tasks in uncertain environments?
In this paper we pursue a solution to this problem by leveraging the idea that
humans often implicitly decompose a higher level task into several subgoals
whose execution brings the task closer to completion. We propose Dirichlet
process based non-parametric Inverse Reinforcement Learning (DPMIRL) approach
for reward based unsupervised clustering of task space into subgoals. This
approach is shown to capture the latent subgoals that a human teacher would
have utilized to train a novice. The notion of action primitive is introduced
as the means to communicate instruction policy to humans in the least
complicated manner, and as a computationally efficient tool to segment
demonstration data. We evaluate our approach through experiments on hydraulic
actuated scaled model of an excavator and evaluate and compare different
teaching strategies utilized by the robot.


title: Mixed-integer convex representability

abstract:
  We consider the question of which nonconvex sets can be represented exactly
as the feasible sets of mixed-integer convex optimization problems. We state
the first complete characterization for the case when the number of possible
integer assignments is finite. We develop a characterization for the more
general case of unbounded integer variables together with a simple necessary
condition for representability which we use to prove the first known negative
results. Finally, we study representability of subsets of the natural numbers,
developing insight towards a more complete understanding of what modeling power
can be gained by using convex sets instead of polyhedral sets; the latter case
has been completely characterized in the context of mixed-integer linear
optimization.


title: Inducing Interpretable Representations with Variational Autoencoders

abstract:
  We develop a framework for incorporating structured graphical models in the
\emph{encoders} of variational autoencoders (VAEs) that allows us to induce
interpretable representations through approximate variational inference. This
allows us to both perform reasoning (e.g. classification) under the structural
constraints of a given graphical model, and use deep generative models to deal
with messy, high-dimensional domains where it is often difficult to model all
the variation. Learning in this framework is carried out end-to-end with a
variational objective, applying to both unsupervised and semi-supervised
schemes.


title: Counting Markov Equivalence Classes by Number of Immoralities

abstract:
  Two directed acyclic graphs (DAGs) are called Markov equivalent if and only
if they have the same underlying undirected graph (i.e. skeleton) and the same
set of immoralities. Using observational data, a DAG model can only be
determined up to Markov equivalence, and so it is desirable to understand the
size and number of Markov equivalence classes (MECs) combinatorially. In this
paper, we address this enumerative question using a pair of generating
functions that encode the number and size of MECs on a skeleton $G$, and in
doing so we connect this problem to classical problems in combinatorial
optimization. The first is a graph polynomial that counts the number of MECs on
$G$ by their number of immoralities. Using connections to the independent set
problem, we show that computing a DAG on $G$ with the maximum possible number
of immoralities is NP-hard. The second generating function counts the MECs on
$G$ according to their size. Via computer enumeration, we show that this
generating function is distinct for every connected graph on $p$ nodes for all
$p\leq 10$.


title:
Gamma-ray signal from Dark Matter Annihilation mediated by mixing scalar
  mediators

abstract:
  We present here a study of the direct and indirect detection prospects of a
generic dark matter simplified model, in which the Majorana dark matter
interacts only with a Standard Model lepton and a pair of uncolored mixing
scalar mediators. We first show that the mixing angle significantly changes the
feature of internal bremsstrahlung, as well as the flux ratio of $\gamma\gamma$
and $\gamma Z$ line signals. The $CP$-violation phase will introduce an
polarization asymmetry in the $\gamma\gamma$ final state. Then we study the
direct detection prospect and discuss the complimentarity of these two search
strategies.


title: Neighborhood-History Quantum Walk

abstract:
  History dependent discrete time quantum walks (QWs) are often studied for
their lattice traversal properties. A particular model in the literature uses
the state of a memory qubit at each site to record visits and to control the
dynamics of the walk. We generalize this model to the neighborhood-history
quantum walk (NHQW), in which the walk dynamics and the state of the memory
qubits in a neighborhood of the particle's position are interdependent. To
demonstrate it, we construct an NHQW on a one-dimensional lattice, with a
simple neighborhood. Several dynamically interesting history dependent QWs can
be realized as single-particle sectors of quantum lattice gas automata (QLGA).
In contrast, the NHQW constructed in this paper is realized as a
single-particle sector of the more general quantum cellular automaton (QCA).
The complexity of the NHQW dynamics presents a promising avenue toward richer
walk strategies and a potentially useful model of QWs for the Noisy
Intermediate-Scale Quantum (NISQ) era of quantum computing. It also modifies
QWs to conceivably allow for modeling fundamental physics incorporating quantum
field interactions with particles.


title: Einstein gravity with torsion induced by the scalar field

abstract:
  We couple a conformal scalar field in (2+1) dimensions to Einstein gravity
with torsion. The field equations are obtained by a variational principle. We
could not solve the Einstein and Cartan equations analytically. These equations
are solved numerically with 4th order Runge-Kutta method. From the numerical
solution, we make an ansatz for the rotation parameter in the proposed metric,
which gives an analytical solution for the scalar field for asymptotic regions.


title: A generalization of Tuza's conjecture

abstract:
  A famous conjecture of Tuza \cite{tuza} is that the minimal number of edges
needed to cover all triangles in a graph is at most twice the maximal number of
edge-disjoint triangles. We propose a wider setting for this conjecture.
  For a hypergraph $H$ let $\nu^{(m)}(H)$ be the maximal size of a collection
of edges, no two of which share $m$ or more vertices, and let $\tau^{(m)}(H)$
be the minimal size of a collection $C$ of sets of $m$ vertices, such that
every edge in $H$ contains a set from $C$. We conjecture that the maximal ratio
$\tau^{(m)}(H)/\nu^{(m)}(H)$ is attained in hypergraphs for which
$\nu^{(m)}(H)=1$. This would imply, in particular, the following generalization
of Tuza's conjecture: if $H$ is $3$-uniform, then $\tau^{(2)}(H)/\nu^{(2)}(H)
\le 2$. (Tuza's conjecture is the case in which $H$ is the set of all triples
of vertices of triangles in the graph). We show that most known results on
Tuza's conjecture go over to this more general setting. We also prove some
general results on the ratio $\tau^{(m)}(H)/\nu^{(m)}(H)$, and study the
fractional versions and the case of $k$-partite hypergraphs.


title: Meson Thermalization by Baryon Injection in D4/D6 Model

abstract:
  We study meson thermalization in a strongly coupled plasma of quarks and
gluons using AdS/CFT duality technique. Four dimensional large-Nc QCD is
considered as a theory governing this quark-gluon plasma (QGP) and D4/D6- brane
model is chosen to be its holographic dual theory. In order to investigate
meson thermalization, we consider a time-dependent change of baryon number
chemical potential. Thermalization in gauge theory side corresponds to horizon
formation on the probe flavor brane in the gravity side. The gravitational dual
theory is compactified on a circle that the inverse of its radius is
proportional to energy scale of dual gauge theory. It is seen that increase of
this energy scale results in thermalization time dilation. In addition we study
the effect of magnetic field on meson thermalization. It will be seen that
magnetic field also prolongs thermalization process by making mesons more
stable.


title:
Representation Formulae and Monotonicity of the Generalized k-Bessel
  Functions

abstract:
  This paper introduces and studies a generalization of the $\mathtt{k}$-Bessel
function of order $\nu$ given by \[\mathtt{W}^{\mathtt{k}}_{\nu, c}(x):=
\sum_{r=0}^\infty \frac{(-c)^r}{\Gamma_{\mathtt{k}}\left( r \mathtt{k}
+\nu+\mathtt{k}\right) r!}
\left(\frac{x}{2}\right)^{2r+\frac{\nu}{\mathtt{k}}}. \] Representation
formulae are derived for $\mathtt{W}^{\mathtt{k}}_{\nu, c}.$ Further the
function $\mathtt{W}^{\mathtt{k}}_{\nu, c}$ is shown to be a solution of a
second order differential equation. Monotonicity and log-convexity properties
for the generalized $\mathtt{k}$-Bessel function $\mathtt{W}^{\mathtt{k}}_{\nu,
c}$ are investigated, particularly in the case $c=-1$. Several inequalities,
including the Tur\'an-type inequality are established.


title:
On the Origin of the Elliptic Flow and its Dependence on the Equation of
  State in Heavy Ion Reactions at Intermediate Energies

abstract:
  Recently it has been discovered that the elliptic flow, v2, of composite
charged particles emitted at midrapidity in Heavy-Ion collisions at
intermediate energies shows the strongest sensitivity to the Nuclear Equation
of State (EoS) which has been observed up to now within a microscopic model.
This dependence on the nuclear EoS is predicted by Quantum Molecular Dynamics
(QMD) calculations [1] which show as well that the absorption or rescattering
of in-plane emitted particles by the spectator matter is not the main reason
for the EoS dependence of the elliptic flow at mid-rapidity but different
density gradients (and therefore different forces) in the direction of the
impact parameter (x-direction) as compared to the direction perpendicular to
the reaction plan (y-direction), caused by the presence of the spectator
matter. The stronger density gradient in y-direction accelerates the particles
more and creates therefore a negative v2. When using a soft momentum dependent
EoS, the QMD calculations reproduce the experimental results.


title: Stable Dyonic Thin-Shell Wormholes in Low-Energy String Theory

abstract:
  Considerable attention has been devoted to the wormhole physics in the past
30 years by exploring the possibilities of finding traversable wormholes
without the need of exotic matter. In particular the thin-shell wormhole
formalism has been widely investigated by exploiting the cut-and-paste
technique to merge two space-time regions and, to research the stability of
these wormholes developed by Visser. This method helps us to minimize the
amount of the exotic matter. In this paper we construct a four dimensional,
spherically symmetric, dyonic thin-shell wormhole with electric charge $Q$,
magnetic charge $P$, and dilaton charge $\Sigma$, in the context of
Einstein-Maxwell-dilaton theory. We have applied Darmois-Israel formalism and
the cut-and-paste method by joining together two identical spacetime solutions.
We carry out the dyonic thin-shell wormhole stability analyses by using a
linear barotropic gas, Chaplygin gas, and logarithmic gas for the exotic
matter. It is shown that by choosing suitable parameter values as well as
equation of state parameter, under specific conditions we obtain a stable
dyonic thin-shell wormhole solution. Finally we argue that, the stability
domain of the dyonic thin-shell wormhole can be increased in terms of electric
charge, magnetic charge, and dilaton charge.


title:
Component-based Synthesis of Table Consolidation and Transformation
  Tasks from Examples

abstract:
  This paper presents an example-driven synthesis technique for automating a
large class of data preparation tasks that arise in data science. Given a set
of input tables and an out- put table, our approach synthesizes a table
transformation program that performs the desired task. Our approach is not
restricted to a fixed set of DSL constructs and can synthesize programs from an
arbitrary set of components, including higher-order combinators. At a
high-level, our approach performs type-directed enumerative search over partial
pro- grams but incorporates two key innovations that allow it to scale: First,
our technique can utilize any first-order specification of the components and
uses SMT-based deduction to reject partial programs. Second, our algorithm uses
partial evaluation to increase the power of deduction and drive enumerative
search. We have evaluated our synthesis algorithm on dozens of data preparation
tasks obtained from on-line forums, and we show that our approach can
automatically solve a large class of problems encountered by R users.


title: Purchasing a C_4 online

abstract:
  Let $G$ be a graph with edge set $(e_1,e_2,...e_N)$. We independently
associate to each edge $e_i$ of $G$ a cost ${x}_i$ that is drawn from a Uniform
[0, 1] distribution. Suppose $\mathcal{F}$ is a set of targeted structures that
consists of subgraphs of $G$. We would like to buy a subset of $\mathcal{F}$ at
small cost, however we do not know a priori the values of the random variables
${x}_1,...,{x}_N$. Instead, we inspect the random variables $x_i$ one at a
time. As soon as we inspect the random variable associated with the cost of an
edge we have to decide whether we want to buy that edge or reject it for ever.
  In the present paper we consider the case where $G$ is the complete graph on
$n$ vertices and $\mathcal{F}$ is the set of all $C_4$ -cycles on 4 vertices-
out of which we want to buy one.


title:
Large net-normal dispersion Er-doped fibre laser mode-locked with a
  nonlinear amplifying loop mirror

abstract:
  We report on an environmentally stable, all-PM-fibre, Er-doped, mode-locked
laser with a central wavelength of 1550 nm. Significantly, the laser possesses
large net-normal dispersion such that its dynamics are comparable to that of an
all-normal dispersion fibre laser at 1 {\mu}m with an analogous architecture.
The laser is mode-locked with a nonlinear amplifying loop mirror to produce
pulses that are externally compressible to 500 fs. Experimental results are in
good agreement with numerical simulations.


title:
Fitting log-linear models in sparse contingency tables using the
  eMLEloglin R package

abstract:
  Log-linear modeling is a popular method for the analysis of contingency table
data. When the table is sparse, and the data falls on a proper face $F$ of the
convex support, there are consequences on model inference and model selection.
Knowledge of the cells determining $F$ is crucial to mitigating these effects.
We introduce the R package (R Core Team (2016)) eMLEloglin for determining $F$
and passing that information on to the glm package to fit the model properly.


title:
Bounding the degrees of a minimal $\mu$-basis for a rational surface
  parametrization

abstract:
  In this paper, we study how the degrees of the elements in a minimal
$\mu$-basis of a parametrized surface behave. For an arbitrary rational surface
parametrization $P(s,t)=(a_1(s,t),a_2(s,t),a_3(s,t),a_4(s,t)) \in
\mathbb{F}[s,t]^4$ over an infinite field $\mathbb{F}$, we show the existence
of a $\mu$-basis with polynomials bounded in degree by $O(d^{33})$, where
$d=\max(\text{deg}(a_1),\text{deg}(a_2), \text{deg}(a_3), \text{deg}(a_4))$.
Under additional assumptions we can obtain tighter bounds.


title: Variational Intrinsic Control

abstract:
  In this paper we introduce a new unsupervised reinforcement learning method
for discovering the set of intrinsic options available to an agent. This set is
learned by maximizing the number of different states an agent can reliably
reach, as measured by the mutual information between the set of options and
option termination states. To this end, we instantiate two policy gradient
based algorithms, one that creates an explicit embedding space of options and
one that represents options implicitly. The algorithms also provide an explicit
measure of empowerment in a given state that can be used by an empowerment
maximizing agent. The algorithm scales well with function approximation and we
demonstrate the applicability of the algorithm on a range of tasks.


title: Perturbative spacetimes from Yang-Mills theory

abstract:
  The double copy relates scattering amplitudes in gauge and gravity theories.
In this paper, we expand the scope of the double copy to construct spacetime
metrics through a systematic perturbative expansion. The perturbative procedure
is based on direct calculation in Yang-Mills theory, followed by squaring the
numerator of certain perturbative diagrams as specified by the double-copy
algorithm. The simplest spherically symmetric, stationary spacetime from the
point of view of this procedure is a particular member of the
Janis-Newman-Winicour family of naked singularities. Our work paves the way for
applications of the double copy to physically interesting problems such as
perturbative black-hole scattering.


title:
A causal framework for discovering and removing direct and indirect
  discrimination

abstract:
  Anti-discrimination is an increasingly important task in data science. In
this paper, we investigate the problem of discovering both direct and indirect
discrimination from the historical data, and removing the discriminatory
effects before the data is used for predictive analysis (e.g., building
classifiers). We make use of the causal network to capture the causal structure
of the data. Then we model direct and indirect discrimination as the
path-specific effects, which explicitly distinguish the two types of
discrimination as the causal effects transmitted along different paths in the
network. Based on that, we propose an effective algorithm for discovering
direct and indirect discrimination, as well as an algorithm for precisely
removing both types of discrimination while retaining good data utility.
Different from previous works, our approaches can ensure that the predictive
models built from the modified data will not incur discrimination in decision
making. Experiments using real datasets show the effectiveness of our
approaches.


title:
A Density Functional Theory Calculations-Based Approach that Predicts
  Layered Materials with Emergent Structures

abstract:
  Recent work shows that density functional theory calculations accurately
describe materials exhibiting turbostratic disorder between layers of
incommensurate constituents. These calculations approximate one of the
constituents as a finite island between continuous layers of the other
constituent. This island approximation allows equal treatment of all relative
angles between the interleaved layers, and it removes the requirement of a unit
cell that is commensurate with both layers. The work presented here uses this
approximation to search for new layered materials that exhibit turbostratic
disorder and magnetic structure. In a first application, the approach finds the
recently synthesized SnSe$_2$-VSe$_2$ system. The approach predicts a stable
Fe$_3$Ge-VSe$_2$ structure and multiple stable structures that interleave
Mn$_x$Se$_y$ layers with VSe$_2$ layers. These Mn$_x$Se$_y$ layers exhibit
emergent structures and stability.


title: Can Broken Multicore Hardware be Mended?

abstract:
  A suggestion is made for mending multicore hardware, which has been diagnosed
as broken.


title:
A Strong Splitting of the Frobenius Morphism on the Algebra of
  Distributions of $SL_2$

abstract:
  Let $p$ be a prime number, and let $Dist(SL_2)$ be the algebra of
distributions, supported at $1$, on the algebraic group $SL_2$ over
$\mathbb{F}_p$. The Frobenius map $Fr:SL_2\to SL_2$ induces a map
$Fr:Dist(SL_2)\to Dist(SL_2)$ which is in particular a surjective algebra
homomorphism. In this note, we construct a section of this map, whenever $p\geq
3$. The main ingredient of this construction is a certain congruence modulo
$p^3$, reminiscent of the congruence $\binom{np}{p}\equiv n\mod p^3$.


title: On a conjecture of Gentner and Rautenbach

abstract:
  Gentner and Rautenbach conjectured that the size of a minimum zero forcing
set in a connected graph on $n$ vertices with maximum degree $3$ is at most
$\frac{1}{3}n+2$. We disprove this conjecture by constructing a collection of
connected graphs $\{G_n\}$ with maximum degree 3 of arbitrarily large order
having zero forcing number at least $\frac{4}{9}|V(G_n)|$.


title: Probing Radiative Neutrino Mass Models With Dilepton Events At The LHC

abstract:
  In this work we prob a class of neutrino mass models at both Large Hadron
Collider (LHC) energies 8 TeV and 14 TeV. The focus will be on the new
introduced interaction terms between a singlet charged scalar, $S^{\pm}$, and
leptons leading to different final states
$pp\rightarrow\ell_{\alpha}^{\pm}\ell_{\beta}^{\mp}$ +$\slashed E$ with
$\ell_{\alpha}\ell_{\beta}=ee,e\mu,\mu\mu$ that implies lepton flavor violation
(LFV). An accurate cut on the $M_{T2}$ eventvariable is found to be crucial for
an effective suppression of the large Standard Model background. The obtained
results can be translated into a possible detectability of the charged scalars
effect..


title:
Memory cost for simulating all quantum correlations of the Peres-Mermin
  scenario

abstract:
  Sequences of compatible quantum measurements can be contextual and any
simulation with a classical model accounting for the quantum observations,
needs to use some internal memory. In Ref. [New J. Phys. 13, 113011 (2011)], it
was shown that simulating the sequences of compatible observables from the
Peres-Mermin scenario requires at least three different memory states in order
to be not in contradiction with the deterministic predictions of quantum
theory. We extend this analysis to the probabilistic quantum predictions and
ask how much memory is required to simulate the quantum correlations generated
by any quantum state. We find, that even in this comprehensive approach only
three internal states are required for the perfect simulation of the quantum
correlations in the Peres-Mermin scenario.


title:
Meteorites and the RNA World: A Thermodynamic Model of Nucleobase
  Synthesis within Planetesimals

abstract:
  The possible meteorite parent body origin of Earth's pregenetic nucleobases
is substantiated by the guanine (G), adenine (A) and uracil (U) measured in
various meteorites. Cytosine (C) and thymine (T) however are absent in
meteorites, making the emergence of a RNA and later RNA/DNA/protein world
problematic. We investigate the meteorite parent body (planetesimal) origin of
all nucleobases by computationally modeling 18 reactions that potentially
contribute to nucleobase formation in such environments. Out of this list, we
identify the two most important reactions for each nucleobase and find that
these involve small molecules such as HCN, CO, NH3, and water that ultimately
arise from the protoplanetary disks in which planetesimals are built. The
primary result of this study is that cytosine is unlikely to persist within
meteorite parent bodies due to aqueous deamination. Thymine has a
thermodynamically favourable reaction pathway from uracil, formaldehyde and
formic acid, but likely did not persist within planetesimals containing H2O2
due to an oxidation reaction with this molecule. Finally, while FT synthesis is
found to be the dominant source of nucleobases within our model planetesimal,
NC synthesis may still be significant under certain chemical conditions (e.g.
within CR2 parent bodies). We discuss several major consequences of our results
for the origin of the RNA world.


title:
Solution of Supplee's submarine paradox through special and general
  relativity

abstract:
  In 1989 Supplee described an apparent relativistic paradox on which a
submarine seems to sink to observers at rest within the ocean, but it rather
seems to float in the submarine proper frame. In this letter, we show that the
paradox arises from a misuse of the Archimedes principle in the relativistic
case. Considering first the special relativity, we show that any relativistic
force field can be written in the Lorentz form, so that it can always be
decomposed into a \emph{static} (electric-like) and a \emph{dynamic}
(magnetic-like) part. These gravitomagnetic effects provide a relativistic
formulation of Archimedes principle, from which the paradox is explained.
Besides, if the curved spacetime on the vicinity of the Earth is taken into
account, we show that the gravitational force exerted by Earth on a moving body
must increase with the speed of the body. The submarine paradox is then
analyzed again with this speed-dependent gravitational force.


title:
Recursive formulation of Madelung continuity equation leads to
  propagation equation

abstract:
  We apply a recursive approach to the continuity equation of the Madelung
fluid resulting in a propagation equation for particle probability densities.
This propagation equation can be used to propagate particle distributions in
the presence of a Madelung pressure field. We show that the derived propagation
equation goes over into the guidance equation of the de Broglie-Bohm theory in
the limit of well located single particles. As an example, we propagate
particles that enter the lower slit of a double-slit experiment, while the
Madelung fluid enters both slits.


title:
Analog electromagnetically induced transparency for circularly polarized
  wave using three dimensional chiral metamaterials

abstract:
  In this paper, we theoretically and experimentally demonstrate a three
dimensional metamaterial that can motivate electromagnetic induced transparency
(EIT) by using circular polarized wave as stimulations. The unit cell consists
of a pair of metallic strips printed on both sides of the printed circuit board
(PCB), where a conductive cylinder junction is used to connect the metal strips
by drilling a hole inside the substrate. When a right circularly polarized wave
is incident, destructive interference is excited between meta-atoms of the 3D
structure, the transmission spectrum demonstrates a sharp transparency window.
A coupled oscillator model and an electrical equivalent circuit model are
applied to quantitatively and qualitatively analyze the coupling mechanism in
the EIT-like metamaterial. Analysis in detail shows the EIT window's amplitude
and frequency are modulated by changing the degree of symmetry breaking. The
proposed metamaterial may achieve potential applications in developing chiral
slow light devices.


title: Photons Squeezing Model in a Nonlinear Micro-ring Resonator

abstract:
  Principally, there are two forms of coupling energy when particle(photon) is
moving around the micro-ring resonator, which is generated by the construction
(creation) and the destruction (annihilation) energies that can disturb the
centre nonlinear microring resonator and lead the system unstable from the
harmonic motion, from which the squeezing state of the particle can occur. The
detected outputs either electrons and their spins or photons can be useful for
the new era of electronic devices and circuits, where the classical
electronics, plasmonic electronics, spintronic electronics and quantum
electronics can be combined and realized.


title: The QUESO Library, User's Manual

abstract:
  QUESO stands for Quantification of Uncertainty for Estimation, Simulation and
Optimization and consists of algorithms and C++ classes intended for research
in uncertainty quantification, including the solution of statistical inverse
problem and statistical forward problems, the validation of mathematical models
under uncertainty, and the prediction of quantities of interest from such
models along with quantification of their uncertainties. QUESO is designed for
flexibility, portability, ease of use and ease of extension. Its software
design follows an object oriented approach and its code is written on C++ and
over MPI. It can run over uniprocessor and multiprocessor environments. QUESO
contains two forms of documentation: a user's manual available in PDF format
and a lower level code documentation available in web based/HTML format. The
present document is a user's manual which provides an overview of the
capabilities of QUESO, procedures for software execution, and includes example
studies.


title: Cluster-Enriched Yang-Baxter Equation from SUSY Gauge Theories

abstract:
  We propose a new generalization of the Yang-Baxter equation, where the
R-matrix depends on cluster $y$-variables in addition to the spectral
parameters. We point out that we can construct solutions to this new equation
from the recently-found correspondence between Yang-Baxter equations and
supersymmetric gauge theories. The $S^2$ partition function of a certain 2d
$\mathcal{N}=(2,2)$ quiver gauge theory gives an R-matrix, whereas its FI
parameters can be identified with the cluster $y$-variables.


title:
Diagrammatic Monte Carlo approach for diagrammatic extensions of
  dynamical mean-field theory -- convergence analysis of the dual fermion
  technique

abstract:
  The dual-fermion approach provides a formally exact prescription for
calculating properties of a correlated electron system in terms of a
diagrammatic expansion around dynamical mean-field theory (DMFT). Most
practical implementations, however, neglect higher-order interaction vertices
beyond two-particle scattering in the dual effective action and further
truncate the diagrammatic expansion in the two-particle scattering vertex to a
leading-order or ladder-type approximation. In this work we compute the
dual-fermion expansion for the two-dimensional Hubbard model including all
diagram topologies with two-particle interactions to high orders by means of a
stochastic diagrammatic Monte Carlo algorithm. We benchmark the obtained
self-energy against numerically exact Diagrammatic Determinant Monte Carlo
simulations to systematically assess convergence of the dual-fermion series and
the validity of these approximations. We observe that, from high temperatures
down to the vicinity of the DMFT N\'eel transition, the dual-fermion series
converges very quickly to the exact solution in the whole range of Hubbard
interactions considered ($4 \leq U/t \leq 12$), implying that contributions
from higher-order vertices are small. As the temperature is lowered further, we
observe slower series convergence, convergence to incorrect solutions, and
ultimately divergence. This happens in a regime where magnetic correlations
become significant. We find however that the self-consistent particle-hole
ladder approximation yields reasonable and often even highly accurate results
in this regime.


title:
Galaxy environment in the 3D-HST fields. Witnessing the onset of
  satellite quenching at z ~ 1-2

abstract:
  We make publicly available a catalog of calibrated environmental measures for
galaxies in the five 3D-HST/CANDELS deep fields. Leveraging the spectroscopic
and grism redshifts from the 3D-HST survey, multi wavelength photometry from
CANDELS, and wider field public data for edge corrections, we derive densities
in fixed apertures to characterize the environment of galaxies brighter than
$JH_{140} < 24$ mag in the redshift range $0.5<z<3.0$. By linking observed
galaxies to a mock sample, selected to reproduce the 3D-HST sample selection
and redshift accuracy, each 3D-HST galaxy is assigned a probability density
function of the host halo mass, and a probability that is a central or a
satellite galaxy. The same procedure is applied to a $z=0$ sample selected from
SDSS. We compute the fraction of passive central and satellite galaxies as a
function of stellar and halo mass, and redshift, and then derive the fraction
of galaxies that were quenched by environment specific processes. Using the
mock sample, we estimate that the timescale for satellite quenching is $t_{\rm
quench} \sim 2-5$ Gyr; longer at lower stellar mass or lower redshift, but
remarkably independent of halo mass. This indicates that, in the range of
environments commonly found within the 3D-HST sample, satellites are quenched
by exhaustion of their gas reservoir in absence of cosmological accretion. We
find that the quenching times can be separated into a delay phase during which
satellite galaxies behave similarly to centrals at fixed stellar mass, and a
phase where the star formation rate drops rapidly ($\sim 0.4-0.6$ Gyr), as
shown previously at $z=0$. We conclude that this scenario requires satellite
galaxies to retain a large reservoir of multi-phase gas upon accretion, even at
high redshift, and that this gas sustains star formation for the long quenching
times observed.


title: Pure Odd Frequency Superconductivity at the Cores of Proximity Vortices

abstract:
  After more than a decade, direct observation of the odd frequency triplet
pairing state in super- conducting hybrid structures remains elusive. We
propose an experimentally feasible setup that can unambiguously reveal the zero
energy peak due to proximity-induced equal spin superconducting triplet
correlations. We theoretically investigate a two dimensional Josephson junction
in the diffu- sive regime. The nanostructure consists of a normal metal
sandwiched between two ferromagnetic layers with spiral magnetization patterns.
By applying an external magnetic field perpendicular to the junction plane,
vortices nucleate in the normal metal. The calculated energy and spatially
resolved density of states, along with the pair potential, reveal that
remarkably, only triplet Cooper pairs survive in the vortex cores. These
isolated odd frequency triplet correlations result in well defined zero energy
peaks in the local density of states that can be identified through tunneling
spectroscopy experiments. Moreover, the diffusive regime considered here rules
out the possibility of Andreev bound states in the vortex core as contributors
to the zero energy peaks.

categories: cond-mat.str-el cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.supr-con quant-ph


title: The weirdest SDSS galaxies: results from an outlier detection algorithm

abstract:
  How can we discover objects we did not know existed within the large datasets
that now abound in astronomy? We present an outlier detection algorithm that we
developed, based on an unsupervised Random Forest. We test the algorithm on
more than two million galaxy spectra from the Sloan Digital Sky Survey and
examine the 400 galaxies with the highest outlier score. We find objects which
have extreme emission line ratios and abnormally strong absorption lines,
objects with unusual continua, including extremely reddened galaxies. We find
galaxy-galaxy gravitational lenses, double-peaked emission line galaxies, and
close galaxy pairs. We find galaxies with high ionisation lines, galaxies which
host supernovae, and galaxies with unusual gas kinematics. Only a fraction of
the outliers we find were reported by previous studies that used specific and
tailored algorithms to find a single class of unusual objects. Our algorithm is
general and detects all of these classes, and many more, regardless of what
makes them peculiar. It can be executed on imaging, time-series, and other
spectroscopic data, operates well with thousands of features, is not sensitive
to missing values, and is easily parallelisable.


title:
The cross-correlation between 21cm intensity mapping maps and the
  Lyman-alpha forest in the post-reionization era

abstract:
  We investigate the cross-correlation signal between 21cm intensity mapping
maps and the Lyman-alpha forest in the fully non-linear regime using
state-of-the-art hydrodynamic simulations. The cross-correlation signal between
these fields can provide a coherent and comprehensive picture of the neutral
hydrogen (HI) content of our Universe in the post-reionization era, probing
both its mass content and volume distribution. We compute the auto-power
spectra of both fields together with their cross-power spectrum at z = 2.4 and
find that on large scales the fields are completely anti-correlated. This
anti-correlation arises because regions with high (low) 21cm emission, such as
those with a large (low) concentration of damped Lyman-alpha systems, will show
up as regions with low (high) transmitted flux. We find that on scales smaller
than k = 0.2 h/Mpc the cross-correlation coefficient departs from -1, at a
scale where non-linearities show up. We use the anisotropy of the power spectra
in redshift-space to determine the values of the bias and of the redshift-space
distortion parameters of both fields; we find that the errors on the value of
these parameters could decrease by 30% when adding data from the cross-power
spectrum in a conservative analysis. Our results point out that linear theory
is capable of reproducing the shape and amplitude of the cross-power up to
rather non-linear scales. Finally, we find that the 21cm-Lya cross-power
spectrum can be detected by combining data from a BOSS-like survey together
with 21cm intensity mapping observations by SKA1-MID with a S/N ratio higher
than 3 in the range 0.06< k <1 h/Mpc. We emphasize that while the shape and
amplitude of the 21cm auto-power spectrum can be severely affected by residual
foreground contamination, cross-power spectra will be less sensitive to that
and therefore can be used to identify systematics in the 21cm maps.


title: Towards holography via quantum source-channel codes

abstract:
  While originally motivated by quantum computation, quantum error correction
(QEC) is currently providing valuable insights into many-body quantum physics
such as topological phases of matter. Furthermore, mounting evidence
originating from holography research (AdS/CFT), indicates that QEC should also
be pertinent for conformal field theories. With this motivation in mind, we
introduce quantum source-channel codes, which combine features of
lossy-compression and approximate quantum error correction, both of which are
predicted in holography. Through a recent construction for approximate recovery
maps, we derive guarantees on its erasure decoding performance from
calculations of an entropic quantity called conditional mutual information. As
an example, we consider Gibbs states of the transverse field Ising model at
criticality and provide evidence that they exhibit non-trivial protection from
local erasure. This gives rise to the first concrete interpretation of a bona
fide conformal field theory as a quantum error correcting code. We argue that
quantum source-channel codes are of independent interest beyond holography.


title:
Fast and efficient evaluation of gravitational waveforms via
  reduced-order spline interpolation

abstract:
  Numerical simulations of merging black hole binaries produce the most
accurate gravitational waveforms. The availability of hundreds of these
numerical relativity (NR) waveforms, often containing many higher spherical
harmonic modes, allows one to study many aspects of gravitational waves.
Amongst these are the response of data analysis pipelines, the calibration of
semi-analytical models, the building of reduced-order surrogates, the
estimation of the parameters of detected gravitational waves, and the
composition of public catalogs of NR waveform data. The large number of
generated NR waveforms consequently requires efficient data storage and
handling, especially since many more waveforms will be generated at an
increased rate in the forthcoming years. In addition, gravitational wave data
analyses often require the NR waveforms to be interpolated and uniformly
resampled at high sampling rates. Previously, this resulted in very large data
files (up to $\sim$ several GB) in memory-intensive operations, which is
unfeasible when confronted with hundreds of multi-modal NR waveforms. To handle
these challenges, we present a simple and efficient method to significantly
\emph{compress} the original waveform data sets while accurately reproducing
the original data via spline interpolation. The method is generically
applicable to relatively smooth, one-dimensional datasets and uses a greedy
algorithm to determine the most relevant subset of the full data such that a
spline interpolant of a specified polynomial degree will represent the original
data to within a requested point-wise tolerance. We find significant
compression of the original NR data sets presented here. These compressed data
sets can then be evaluated fast and efficiently and resampled as desired.


title: Purification in Rapid Repeated Interaction Systems

abstract:
  We investigate the open dynamics of a quantum system when it is rapidly
repeatedly updated by a quantum channel. Specifically, we analyze when this
dynamics can purify the system. We develop a necessary and sufficient condition
for such purification effects to occur and characterize their strength. We
thoroughly analyze the specific scenario of a quantum system undergoing rapid
unitary interactions with a sequence of ancillary quantum systems. We find that
while the purification effects are generally present, in order for these
effects to be strong compared to the decoherence effects the interaction
Hamiltonian must have a minimum degree of complexity. Specifically, a tensor
product interaction $\hat{Q}_\text{S}\otimes\hat{R}_\text{A}$, as well as many
common light-matter interactions cannot purify efficiently.


title: Effects of waveform model systematics on the interpretation of GW150914

abstract:
  Parameter estimates of GW150914 were obtained using Bayesian inference, based
on three semi-analytic waveform models for binary black hole coalescences.
These waveform models differ from each other in their treatment of black hole
spins, and all three models make some simplifying assumptions, notably to
neglect sub-dominant waveform harmonic modes and orbital eccentricity.
Furthermore, while the models are calibrated to agree with waveforms obtained
by full numerical solutions of Einstein's equations, any such calibration is
accurate only to some non-zero tolerance and is limited by the accuracy of the
underlying phenomenology, availability, quality, and parameter-space coverage
of numerical simulations. This paper complements the original analyses of
GW150914 with an investigation of the effects of possible systematic errors in
the waveform models on estimates of its source parameters. To test for
systematic errors we repeat the original Bayesian analyses on mock signals from
numerical simulations of a series of binary configurations with parameters
similar to those found for GW150914. Overall, we find no evidence for a
systematic bias relative to the statistical error of the original parameter
recovery of GW150914 due to modeling approximations or modeling inaccuracies.
However, parameter biases are found to occur for some configurations disfavored
by the data of GW150914: for binaries inclined edge-on to the detector over a
small range of choices of polarization angles, and also for eccentricities
greater than $\sim$0.05. For signals with higher signal-to-noise ratio than
GW150914, or in other regions of the binary parameter space (lower masses,
larger mass ratios, or higher spins), we expect that systematic errors in
current waveform models may impact gravitational-wave measurements, making more
accurate models desirable for future observations.


title: A closer look at the "characteristic" width of molecular cloud filaments

abstract:
  Filaments in Herschel molecular cloud images are found to exhibit a
"characteristic width". This finding is in tension with spatial power spectra
of the data, which show no indication of this characteristic scale. We
demonstrate that this discrepancy is a result of the methodology adopted for
measuring filament widths. First, we perform the previously used analysis
technique on artificial scale-free data, and obtain a peaked width distribution
of filament-like structures. Next, we repeat the analysis on three Herschel
maps and reproduce the narrow distribution of widths found in previous studies
$-$ when considering the average width of each filament. However, the
distribution of widths measured at all points along a filament spine is broader
than the distribution of mean filament widths, indicating that the narrow
spread (interpreted as a "characteristic" width) results from averaging.
Furthermore, the width is found to vary significantly from one end of a
filament to the other. Therefore, the previously identified peak at 0.1 pc
cannot be understood as representing the typical width of filaments. We find an
alternative explanation by modelling the observed width distribution as a
truncated power-law distribution, sampled with uncertainties. The position of
the peak is connected to the lower truncation scale and is likely set by the
choice of parameters used in measuring filament widths. We conclude that a
"characteristic" width of filaments is not supported by the available data.


title:
Turbulence and Particle Acceleration in Giant Radio Haloes: the Origin
  of Seed Electrons

abstract:
  About 1/3 of X-ray-luminous clusters show smooth, Mpc-scale radio emission,
known as giant radio haloes. One promising model for radio haloes is Fermi-II
acceleration of seed relativistic electrons by compressible turbulence. The
origin of these seed electrons has never been fully explored. Here, we
integrate the Fokker-Planck equation of the cosmic ray (CR) electron and proton
distributions when post-processing cosmological simulations of cluster
formation, and confront them with radio surface brightness and spectral data of
Coma. For standard assumptions, structure formation shocks lead to a seed
electron population which produces too centrally concentrated radio emission.
Matching observations requires modifying properties of the CR population (rapid
streaming; enhanced CR electron acceleration at shocks) or turbulence
(increasing turbulent-to-thermal energy density with radius), but at the
expense of fine-tuning. In a parameter study, we find that radio properties are
exponentially sensitive to the amplitude of turbulence, which is inconsistent
with small scatter in scaling relations. This sensitivity is removed if we
relate the acceleration time to the turbulent dissipation time. In this case,
turbulence above a threshold value provides a fixed amount of amplification;
observations could thus potentially constrain the unknown CR seed population.
To obtain sufficient acceleration, the turbulent magneto-hydrodynamics cascade
has to terminate by transit time damping on CRs, i.e., thermal particles must
be scattered by plasma instabilities. Understanding the small scatter in radio
halo scaling relations may provide a rich source of insight on plasma processes
in clusters.


title: Soft Photon and Graviton Theorems in Effective Field Theory

abstract:
  Extensions of the photon and graviton soft theorems are derived in 4d local
effective field theories with massless particles of arbitrary spin. We prove
that effective operators can result in new terms in the soft theorems at
subleading order for photons and subsubleading order for gravitons. The new
soft terms are unique and we provide a complete classification of all local
operators responsible for such modifications. We show that no local operators
can modify the subleading soft graviton theorem. The soft limits are taken in a
manifestly on-locus manner using a complex double deformation of the external
momenta. In addition to the new soft theorems, the resulting master formula
yields consistency conditions such as the conservation of electric charge, the
Einstein equivalence principle, supergravity Ward identities, and the
Weinberg-Witten theorem.


title: Massive three-loop form factor in the planar limit

abstract:
  We compute the three-loop QCD corrections to the massive
quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit.
The analytic results are expressed in terms of Goncharov polylogarithms. This
allows for a straightforward numerical evaluation. We also derive series
expansions, including power suppressed terms, for three kinematic regions
corresponding to small and large invariant masses of the photon momentum, and
small velocities of the heavy quarks.


title:
Partial time-reversal transformation and entanglement negativity in
  fermionic systems

abstract:
  The partial transpose of density matrices in many-body quantum systems, in
which one takes the transpose only for a subsystem of the full Hilbert space,
has been recognized as a useful tool to diagnose quantum entanglement. It can
be used, for example, to define the (logarithmic) negativity. For fermionic
systems, it has been known that the partial transpose of Gaussian fermionic
density matrices is not Gaussian. In this work, we propose to use partial
time-reversal transformation to define (an analog of) the entanglement
negativity and related quantities. We demonstrate that for the
symmetry-protected topological phase realized in the Kitaev chain the
conventional definition of the partial transpose (and hence the entanglement
negativity) fails to capture the formation of the edge Majorana fermions, while
the partial time-reversal computes the quantum dimension of the Majorana
fermions. Furthermore, we show that the partial time-reversal of fermionic
density matrices is Gaussian and can be computed efficiently. Various results
(both numerical and analytical) for the entanglement negativity using the
partial-time reversal are presented for (1+1)-dimensional conformal field
theories, and also for fermionic disordered systems (random single phases).


title: Analyzing Genome-wide Association Study Data with the R Package genMOSS

abstract:
  The R package (R Core Team (2016)) genMOSS is specifically designed for the
Bayesian analysis of genome-wide association study data. The package implements
the mode oriented stochastic search (MOSS) procedure as well as a simple moving
window approach to identify combinations of single nucleotide polymorphisms
associated with a response. The prior used in Bayesian computations is the
generalized hyper Dirichlet.


title:
Robust Bain distortion in the premartensite phase of platinum
  substituted Ni2MnGa magnetic shape memory alloy

abstract:
  The premartensite phase of shape memory and magnetic shape memory alloys
(MSMAs) is believed to be a precursor state of the martensite phase with
preserved austenite phase symmetry. The thermodynamic stability of the
premartensite phase and its relation to the martensitic phase is still an
unresolved issue, even though it is critical to the understanding of the
functional properties of MSMAs. We present here unambiguous evidence for
macroscopic symmetry breaking leading to robust Bain distortion in the
premartensite phase of 10% Pt substituted Ni2MnGa. We show that the robust Bain
distorted premartensite (T2) phase results from another premartensite (T1)
phase with preserved cubic-like symmetry through an isostructural phase
transition. The T2 phase finally transforms to the martensite phase with
additional Bain distortion on further cooling. Our results demonstrate that the
premartensite phase should not be considered as a precursor state with the
preserved symmetry of the cubic austenite phase.


title:
Improving the pseudo-randomness properties of chaotic maps using
  deep-zoom

abstract:
  A generalized method is proposed to compose new orbits from a given chaotic
map. The method provides an approach to examine discrete-time chaotic maps in a
"deep-zoom" manner by using $k$-digits to the right from the decimal separator
of a given point from the underlying chaotic map. Interesting phenomena have
been identified. Rapid randomization was observed, i.e. chaotic patterns tend
to become indistinguishable, when compared to the original orbits of the
underlying chaotic map. Our results were presented using different graphical
analyses (i.e., time-evolution, bifurcation diagram, Lyapunov exponent,
Poincar\'e diagram and frequency distribution). Moreover, taking advantage of
this randomization improvement, we propose a Pseudo-Random Number Generator
(PRNG) based on the $k$-logistic map. The pseudo-random qualities of the
proposed PRNG passed both tests successfully, i.e. DIEHARD and NIST, and were
comparable with other traditional PRNGs such as the Mersenne Twister. The
results suggest that simple maps such as the logistic map can be considered as
good PRNG methods.


title: Basis-neutral Hilbert-space analyzers

abstract:
  Interferometry is one of the central organizing principles of optics. Key to
interferometry is the concept of optical delay, which facilitates spectral
analysis in terms of time-harmonics. In contrast, when analyzing a beam in a
Hilbert space spanned by spatial modes -- a critical task for spatial-mode
multiplexing and quantum communication -- basis-specific principles are invoked
that are altogether distinct from that of `delay.' Here, we extend the
traditional concept of temporal delay to the spatial domain, thereby enabling
the analysis of a beam in an arbitrary spatial-mode basis -- exemplified using
Hermite-Gaussian and radial Laguerre-Gaussian modes. Such generalized delays
correspond to optical implementations of fractional transforms; for example,
the fractional Hankel transform is the generalized delay associated with the
space of Laguerre-Gaussian modes, and an interferometer incorporating such a
`delay' obtains modal weights in the associated Hilbert space. By implementing
an inherently stable, reconfigurable spatial-light-modulator-based
polarization- interferometer, we have constructed a `Hilbert-space analyzer'
capable of projecting optical beams onto any modal basis.


title:
Data Structures for Weighted Matching and Extensions to $b$-matching and
  $f$-factors

abstract:
  This paper shows the weighted matching problem on general graphs can be
solved in time $O(n(m + n\log n))$ for $n$ and $m$ the number of vertices and
edges, respectively. This was previously known only for bipartite graphs. The
crux is a data structure for blossom creation. It uses a dynamic
nearest-common-ancestor algorithm to simplify blossom steps, so they involve
only back edges rather than arbitrary nontree edges.
  The rest of the paper presents direct extensions of Edmonds' blossom
algorithm to weighted $b$-matching and $f$-factors. Again the time bound is the
one previously known for bipartite graphs: for $b$-matching the time is
$O(\min\{b(V),n\log n\}(m + n\log n))$ and for $f$-factors the time is
$O(\min\{f(V),m\log n\}( m + n\log n) )$, where $b(V)$ and $f(V)$ denote the
sum of all degree constraints. Several immediate applications of the $f$-factor
algorithm are given: The generalized shortest path structure of \cite{GS13},
i.e., the analog of the shortest path tree for conservative undirected graphs,
is shown to be a version of the blossom structure for $f$-factors. This
structure is found in time $O(|N|(m+n\log n))$ for $N$ the set of negative
edges ($0<|N|<n$). A shortest $T$-join is found in time $O(n(m+n\log n))$, or
$O(|T|(m+n\log n))$ when all costs are nonnegative. These bounds are all slight
improvements of previously known ones, and are simply achieved by proper
initialization of the $f$-factor algorithm.


title: Multi-neutron emission of Cd isotopes

abstract:
  An influence of the phonon-phonon coupling (PPC) on the $\beta$-decay
half-lives and multi-neutron emission probabilities is analysed within the
microscopic model based on the Skyrme interaction with tensor components
included. The finite-rank separable approximation is used in order to handle
large two-quasiparticle spaces. The even-even nuclei near the r-process pathes
at $N=82$ are studied. The characteristics of ground states, $2^+$ excitations
and $\beta$-decay strength of the neutron-rich Cd isotopes are treated in
detail. It is shown that a strong redistribution of the Gamow-Teller strength
due to the PPC is mostly sensitive to the multi-neutron emission probability of
the Cd isotopes.


title: Positively finitely related profinite groups

abstract:
  We define and study the class of positively finitely related (PFR) profinite
groups. Positive finite relatedness is a probabilistic property of profinite
groups which provides a first step to defining higher finiteness properties of
profinite groups which generalize the positively finitely generated groups
introduced by Avinoam Mann. We prove many asymptotic characterisations of PFR
groups, for instance we show the following: a finitely presented profinite
group is PFR if and only if it has at most exponential representation growth,
uniformly over finite fields (in other words: the completed group algebra has
polynomial maximal ideal growth). From these characterisations we deduce
several structural results on PFR profinite groups.


title:
Self-learning Scene-specific Pedestrian Detectors using a Progressive
  Latent Model

abstract:
  In this paper, a self-learning approach is proposed towards solving
scene-specific pedestrian detection problem without any human' annotation
involved. The self-learning approach is deployed as progressive steps of object
discovery, object enforcement, and label propagation. In the learning
procedure, object locations in each frame are treated as latent variables that
are solved with a progressive latent model (PLM). Compared with conventional
latent models, the proposed PLM incorporates a spatial regularization term to
reduce ambiguities in object proposals and to enforce object localization, and
also a graph-based label propagation to discover harder instances in adjacent
frames. With the difference of convex (DC) objective functions, PLM can be
efficiently optimized with a concave-convex programming and thus guaranteeing
the stability of self-learning. Extensive experiments demonstrate that even
without annotation the proposed self-learning approach outperforms weakly
supervised learning approaches, while achieving comparable performance with
transfer learning and fully supervised approaches.


title:
Largest projections for random walks and shortest curves in random
  mapping tori

abstract:
  We show that the largest subsurface projection distance between a marking and
its image under the nth step of a random walk grows logarithmically in n, with
probability approaching 1 as n tends to infinity. Our setup is general and also
applies to (relatively) hyperbolic groups and to $\mathrm{Out}(F_n)$. We then
use this result to prove Rivin's conjecture that for a random walk $(w_n)$ on
the mapping class group, the shortest geodesic in the hyperbolic mapping torus
$M_{w_n}$ has length on the order of $1/ \log^2(n)$.


title: Local entropy of a nonequilibrium fermion system

abstract:
  The local entropy of a nonequilibrium system of independent fermions is
investigated, and analyzed in the context of the laws of thermodynamics. It is
shown that the local temperature and chemical potential can only be expressed
in terms of derivatives of the local entropy for linear deviations from local
equilibrium. The first law of thermodynamics is shown to lead to an inequality,
not an equality, for the change in the local entropy as the nonequilibrium
state of the system is changed. The maximum entropy principle (second law of
thermodynamics) is proven: a nonequilibrium distribution has a local entropy
less than or equal to a local equilibrium distribution satisfying the same
constraints. It is shown that the local entropy of the system tends to zero
when the local temperature tends to zero, consistent with the third law of
thermodynamics.


title: Aspects of Duality in Cosmology

abstract:
  In the first part of this article, given the intent to stay at a popular
level, it has been introduced and explained briefly basic concepts of
Einstein's General Relativity, Dark Matter, Dark Energy, String Theory, Quantum
Gravity and Extended Theories of Gravity. The core of this research is based on
selecting a class of f(R) theories of gravity, which exhibits scale factor
duality transformations. The starting point of this theory is the effective
theory of gravity derived from Bosonic String Theory, which is called tree
level effective theory of gravity. It is shown that this theory can be cast in
a class of f(R) theories of gravity (modified theories of Einstein's General
Relativity). It is imposed that FLRW metric be solution of this class of $f(R)$
theories, and, using the Noether symmetry approach, it is found that the
cosmological model has scale factor duality like the Pre-Big Bang cosmology of
Gasperini and Veneziano.


title: Total nonnegativity and stable polynomials

abstract:
  We consider homogeneous multiaffine polynomials whose coefficients are the
Pl\"ucker coordinates of a point $V$ of the Grassmannian. We show that such a
polynomial is stable (with respect to the upper half plane) if and only if $V$
is in the totally nonnegative part of the Grassmannian. To prove this, we
consider an action of matrices on multiaffine polynomials. We show that a
matrix $A$ preserves stability of polynomials if and only if $A$ is totally
nonnegative. The proofs are applications of classical theory of totally
nonnegative matrices, and the generalized P\'olya-Schur theory of Borcea and
Br\"and\'en.


title:
On the Benefit of Automated Static Analysis for Small and Medium-Sized
  Software Enterprises

abstract:
  Today's small and medium-sized enterprises (SMEs) in the software industry
are faced with major challenges. While having to work efficiently using limited
resources they have to perform quality assurance on their code to avoid the
risk of further effort for bug fixes or compensations. Automated static
analysis can reduce this risk because it promises little effort for running an
analysis. We report on our experience in analysing five projects from and with
SMEs by three different static analysis techniques: code clone detection, bug
pattern detection and architecture conformance analysis. We found that the
effort that was needed to introduce those techniques was small (mostly below
one person-hour), that we can detect diverse defects in production code and
that the participating companies perceived the usefulness of the presented
techniques as well as our analysis results high enough to include the
techniques in their quality assurance.


title:
On the period of the periodic orbits of the restricted three body
  problem

abstract:
  We will show that the period $T$ of a closed orbit of the planar circular
restricted three-body problem (viewed on rotating coordinates) depends on the
region it encloses. Roughly speaking, we show that, $2 T=k\pi+\int_\Omega g$
where $k$ is an integer, $\Omega$ is the region enclosed by the periodic orbit
and $g:\mathbb{R}^2\to \mathbb{R}$ is a function that only depends on the
constant $C$ known as the Jacobian integral; it does not depend on $\Omega$.
This theorem has a Keplerian flavor in the sense that it relates the period
with the space "swept" by the orbit. As an application, we prove that there is
a neighborhood around $L_4$ such that every periodic solution contained in this
neighborhood must move clockwise. The same result holds true for $L_5$.


title: Maximal irreducibility measure for spatial birth-and-death processes

abstract:
  We prove that under certain general conditions on the birth and death rates
the Lebesgue-Poisson measure is a maximal irreducibility measure for the
spatial birth-and-death process.


title: Parameter Setting for Quantum Annealers

abstract:
  We develop and apply several strategies for setting physical parameters on
quantum annealers for application problems that do not fit natively on the
hardware graph. The strategies are tested with a culled random set of mixed
satisfiability problems, yielding results that generalize to guidelines
regarding which parameter setting strategies to use for different classes of
problems, and how to choose other necessary hardware quantities as well.
Alternate methods of changing the hardware implementation of an application
problem are also considered and their utility discussed.


title: Uncertainty product of an out-of-equilibrium Bose-Einstein condensate

abstract:
  The variance and uncertainty product of the position and momentum
many-particle operators of structureless bosons interacting by a long-range
inter-particle interaction and trapped in a single-well potential are
investigated. In the first example, of an out-of-equilibrium interaction-quench
scenario, it is found that, despite the system being fully condensed, already
when a fraction of a particle is depleted differences with respect to the
mean-field quantities emerge. In the second example, of the pathway from
condensation to fragmentation of the ground state, we find out that, although
the cloud's density broadens while the system's fragments, the position
variance actually decreases, the momentum variance increases, and the
uncertainty product is not a monotonous function but has a maximum. Implication
are briefly discussed.