title:
Similarities in the structure of the circumstellar environments of B[e]
  supergiants and yellow hypergiants

abstract:
  Yellow Hypergiants (YHGs) and B[e] supergiants (B[e]SGs), though in different
phases in their evolution, display many features in common. This is partly due
to the fact that both types of objects undergo strong, often asymmetric mass
loss, and the ejected material accumulates in shells, rings, or disk-like
structures, giving rise to emission from warm molecules and dust. We performed
an optical spectroscopic survey of northern Galactic emission-line stars aimed
at identifying tracers for the structure and kinematics of circumstellar
environments. We identified two sets of lines, [O I] and [Ca II], which
originate from the discs of B[e]SGs. The same set of lines is observed in V1302
Aql and V509 Cas, which are both hot YHGs. While V1302 Aql is known to have a
disc-like structure, the kinematical broadening of the lines in V509 Cas
suggest a Keplerian disk or ring around this star alike their hotter B[e]SG
counterparts.


title:
Ranking medical jargon in electronic health record notes by adapted
  distant supervision

abstract:
  Objective: Allowing patients to access their own electronic health record
(EHR) notes through online patient portals has the potential to improve
patient-centered care. However, medical jargon, which abounds in EHR notes, has
been shown to be a barrier for patient EHR comprehension. Existing knowledge
bases that link medical jargon to lay terms or definitions play an important
role in alleviating this problem but have low coverage of medical jargon in
EHRs. We developed a data-driven approach that mines EHRs to identify and rank
medical jargon based on its importance to patients, to support the building of
EHR-centric lay language resources.
  Methods: We developed an innovative adapted distant supervision (ADS) model
based on support vector machines to rank medical jargon from EHRs. For distant
supervision, we utilized the open-access, collaborative consumer health
vocabulary, a large, publicly available resource that links lay terms to
medical jargon. We explored both knowledge-based features from the Unified
Medical Language System and distributed word representations learned from
unlabeled large corpora. We evaluated the ADS model using physician-identified
important medical terms.
  Results: Our ADS model significantly surpassed two state-of-the-art automatic
term recognition methods, TF*IDF and C-Value, yielding 0.810 ROC-AUC versus
0.710 and 0.667, respectively. Our model identified 10K important medical
jargon terms after ranking over 100K candidate terms mined from over 7,500 EHR
narratives.
  Conclusion: Our work is an important step towards enriching lexical resources
that link medical jargon to lay terms/definitions to support patient EHR
comprehension. The identified medical jargon terms and their rankings are
available upon request.


title: Top physics at CLIC and ILC

abstract:
  Measurements of top quark production at $e^+e^-$ colliders can provide a leap
in precision in our knowledge of top quark properties and open a new window on
physics beyond the Standard Model. In this contribution the top quark physics
prospects of linear colliders is reviewed. Progress in detailed full-simulation
studies is reported for the highlights of the program. We present the prospects
for a measurement of the top quark mass and width in a scan of the beam energy
through the pair production threshold, and discuss new studies of alternative
measurements in continuum production, which are also capable of a precise
determination of the mass in a rigorously defined mass scheme. A precision of
50 MeV on the $\overline{MS}$ mass is expected when taking into account the
dominant systematic uncertainties. Another key measurement is the study of the
top quark couplings to electroweak gauge bosons, where form factors can be
determined to 1% precision, an order of magnitude better than those from the
full LHC program. New results extend the prospects to different center-of-mass
energies and to CP violating form factors. Finally, new studies are presented
indicating the possibility to detect Flavour Changing Neutral Current decays of
the top quark at linear colliders, such as the decay $t \rightarrow cH$, to a
branching ratio of $BR(t\rightarrow cH) \sim 10^{-5}$.


title: A new outburst of the yellow hypergiant star $\rho$ Cas

abstract:
  Spectroscopic monitoring of the yellow hypergiant $\rho$ Cas revealed a new
outburst in 2013, which is obvious from the development of TiO bands in the
spectra. Also many atmospheric lines characteristic for a later spectral type
appear. This spectroscopic outburst is in agreement with the photometric light
curve, which displays a drop by about 0.6 mag during the same period.


title: Predictable Forward Performance Processes: The Binomial Case

abstract:
  We introduce a new class of forward performance processes that are endogenous
and predictable with regards to an underlying market information set and,
furthermore, are updated at discrete times. We analyze in detail a binomial
model whose parameters are random and updated dynamically as the market
evolves. We show that the key step in the construction of the associated
predictable forward performance process is to solve a single-period inverse
investment problem, namely, to determine, period-by-period and conditionally on
the current market information, the end-time utility function from a given
initial-time value function. We reduce this inverse problem to solving a
functional equation and establish conditions for the existence and uniqueness
of its solutions in the class of inverse marginal functions.


title:
Detection Performance with Many Antennas Available for
  Bandwidth-Efficient Uplink Transmission in MU-MIMO Systems

abstract:
  This paper is concerned with SC/FDE for bandwidth-efficient uplink block
transmission, with QAM schemes, in a MU MIMO system. The number of BS receiver
antennas is assumed to be large, but not necessarily much larger than the
overall number of transmitter antennas jointly using the same time/frequency
resource at MT.
  In this context, we consider several detection techniques and evaluate, in
detail, the corresponding detection performances (discussed with the help of
selected performance bounds), for a range of values regarding the number of
available BS receiver antennas. From our performance results, we conclude that
simple linear detection techniques, designed to avoid the need of complex
matrix inversions, can lead to unacceptably high error floor levels. However,
by combining the use of such simple linear detectors with an appropriate
interference cancellation procedure - within an iterative DF technique -, a
close approximation to the SIMO MFB performance can be achieved after a few
iterations, even for 64-QAM schemes, when the number of BS antennas is, at
least, five times higher than the number of antennas which are jointly used at
the user terminals.


title: Multi-view Recurrent Neural Acoustic Word Embeddings

abstract:
  Recent work has begun exploring neural acoustic word
embeddings---fixed-dimensional vector representations of arbitrary-length
speech segments corresponding to words. Such embeddings are applicable to
speech retrieval and recognition tasks, where reasoning about whole words may
make it possible to avoid ambiguous sub-word representations. The main idea is
to map acoustic sequences to fixed-dimensional vectors such that examples of
the same word are mapped to similar vectors, while different-word examples are
mapped to very different vectors. In this work we take a multi-view approach to
learning acoustic word embeddings, in which we jointly learn to embed acoustic
sequences and their corresponding character sequences. We use deep
bidirectional LSTM embedding models and multi-view contrastive losses. We study
the effect of different loss variants, including fixed-margin and
cost-sensitive losses. Our acoustic word embeddings improve over previous
approaches for the task of word discrimination. We also present results on
other tasks that are enabled by the multi-view approach, including cross-view
word discrimination and word similarity.


title:
Favorite sites of randomly biased walks on a supercritical Galton-Watson
  tree

abstract:
  Erd\H{o}s and R\'ev\'esz initiated the study of favorite sites by considering
the one-dimensional simple random walk. We investigate in this paper the same
problem for a class of null-recurrent randomly biased walks on a supercritical
Gaton-Watson tree. We prove that there is some parameter $\kappa \in (1,
\infty]$ such that the set of the favorite sites of the biased walk is almost
surely bounded in the case $\kappa \in (2, \infty]$, tight in the case
$\kappa=2$, and oscillates between a neighborhood of the root and the boundary
of the range in the case $\kappa \in (1, 2)$. Moreover, our results yield a
complete answer to the cardinality of the set of favorite sites in the case
$\kappa \in (2, \infty]$. The proof relies on the exploration of the Markov
property of the local times process with respect to the space variable and on a
precise tail estimate on the maximum of local times, using a change of measure
for multi-type Galton-Watson trees.


title: Lattice points in elliptic paraboloids

abstract:
  We consider the lattice point problem corresponding to a family of elliptic
paraboloids in $\mathbb{R}^d$ with $d\ge3$ and we prove the expected to be
optimal exponent, improving previous results. This is especially noticeable for
$d=3$ because the optimal exponent is conjectural even for the sphere. We also
treat some aspects of the case $d=2$, getting for a simple parabolic region an
$\Omega$-result that is unknown for the classical circle and divisor problems.


title: Post Training in Deep Learning with Last Kernel

abstract:
  One of the main challenges of deep learning methods is the choice of an
appropriate training strategy. In particular, additional steps, such as
unsupervised pre-training, have been shown to greatly improve the performances
of deep structures. In this article, we propose an extra training step, called
post-training, which only optimizes the last layer of the network. We show that
this procedure can be analyzed in the context of kernel theory, with the first
layers computing an embedding of the data and the last layer a statistical
model to solve the task based on this embedding. This step makes sure that the
embedding, or representation, of the data is used in the best possible way for
the considered task. This idea is then tested on multiple architectures with
various data sets, showing that it consistently provides a boost in
performance.


title: Deep Learning with Sets and Point Clouds

abstract:
  We introduce a simple permutation equivariant layer for deep learning with
set structure.This type of layer, obtained by parameter-sharing, has a simple
implementation and linear-time complexity in the size of each set. We use deep
permutation-invariant networks to perform point-could classification and
MNIST-digit summation, where in both cases the output is invariant to
permutations of the input. In a semi-supervised setting, where the goal is make
predictions for each instance within a set, we demonstrate the usefulness of
this type of layer in set-outlier detection as well as semi-supervised learning
with clustering side-information.


title: Material-independent modes for electromagnetic scattering

abstract:
  In this Letter, we introduce a representation of the electromagnetic field
for the analysis and synthesis of the full-wave scattering by a homogeneous
dielectric object of arbitrary shape in terms of a set of eigenmodes
independent of its permittivity. The expansion coefficients are rational
functions of the permittivity. This approach naturally highlights the role of
plasmonic and photonic modes in any scattering process and suggests a
straightforward methodology to design the permittivity of the object to pursue
a prescribed tailoring of the scattered field. We discuss in depth the
application of the proposed approach to the analysis and design of the
scattering properties of a dielectric sphere.


title: B fields in OB stars (BOB): Concluding the FORS2 observing campaign

abstract:
  The "B fields in OB stars" (BOB) collaboration is based on an ESO Large
Programme, to study the occurrence rate, properties, and ultimately the origin
of magnetic fields in massive stars.
  In the framework of this programme, we carried out low-resolution
spectropolarimetric observations of a large sample of massive stars using FORS2
installed at the ESO VLT 8-m telescope.
  We determined the magnetic field values with two completely independent
reduction and analysis pipelines. Our in-depth study of the magnetic field
measurements shows that differences between our two pipelines are usually well
within 3sigma errors. From the 32 observations of 28 OB stars, we were able to
monitor the magnetic fields in CPD-57 3509 and HD164492C, confirm the magnetic
field in HD54879, and detect a magnetic field in CPD-62 2124. We obtain a
magnetic field detection rate of 6+-3% for the full sample of 69 OB stars
observed with FORS2 within the BOB programme. For the pre-selected objects with
a v sin i below 60 km/s, we obtain a magnetic field detection rate of 5+-5%. We
also discuss X-ray properties and multiplicity of the objects in our FORS2
sample with respect to the magnetic field detections.


title:
Zero-resource Machine Translation by Multimodal Encoder-decoder Network
  with Multimedia Pivot

abstract:
  We propose an approach to build a neural machine translation system with no
supervised resources (i.e., no parallel corpora) using multimodal embedded
representation over texts and images. Based on the assumption that text
documents are often likely to be described with other multimedia information
(e.g., images) somewhat related to the content, we try to indirectly estimate
the relevance between two languages. Using multimedia as the "pivot", we
project all modalities into one common hidden space where samples belonging to
similar semantic concepts should come close to each other, whatever the
observed space of each sample is. This modality-agnostic representation is the
key to bridging the gap between different modalities. Putting a decoder on top
of it, our network can flexibly draw the outputs from any input modality.
Notably, in the testing phase, we need only source language texts as the input
for translation. In experiments, we tested our method on two benchmarks to show
that it can achieve reasonable translation performance. We compared and
investigated several possible implementations and found that an end-to-end
model that simultaneously optimized both rank loss in multimodal encoders and
cross-entropy loss in decoders performed the best.


title:
Accelerated expansion of the universe and chasing photons from the CMB
  to study the late time integrated Sachs-Wolfe effect over different redshift
  ranges

abstract:
  In this study, we are going to discuss the accelerated expansion of the
universe and how this accelerated expansion affects the paths of photons from
cosmic microwave background radiation (CMB). Then we will see how wide-field
galaxy surveys along with cosmic CMB anisotropy maps can help us in studying
dark energy. The cross-correlation of galaxy over/under-density maps with CMB
anisotropy maps help us in measuring one of the most useful signatures of dark
energy i.e. Integrated Sachs-Wolfe (ISW) effect. ISW effect explains the
blue-shifting and red-shifting of CMB photons when they reach to us after
passing through large scale structures and super-voids respectively. We will
look into the theoretical foundations behind ISW effect and discuss how modern
all sky galaxy surveys like EMU-ASKAP will be useful in studying the effect.


title: Mar\v{c}enko-Pastur Law for Kendall's Tau

abstract:
  We prove that Kendall's Rank correlation matrix converges to the
Mar\v{c}enko-Pastur law, under the assumption that the observations are i.i.d
random vectors $X_1$, $\dots$, $X_n$ with components that are independent and
absolutely continuous with respect to the Lebesgue measure. This is the first
result on the empirical spectral distribution of a multivariate $U$-statistic.


title:
On the visualization of the detected communities in dynamic networks: A
  case study of Twitter's network

abstract:
  Understanding the information behind social relationships represented by a
network is very challenging, especially, when the social interactions change
over time inducing updates on the network topology. In this context, this paper
proposes an approach for analysing dynamic social networks, more precisely for
Twitter's network. Our approach relies on two complementary steps: (i) an
online community identification based on a dynamic community detection
algorithm called Dyci. The main idea of Dyci is to track whether a connected
component of the weighted graph becomes weak over time, in order to merge it
with the "dominant" neighbour community. Additionally, (ii) a community
visualization is provided by our visualization tool called NLCOMS, which
combines between two methods of dynamic network visualization. In order to
assess the efficiency and the applicability of the proposed approach, we
consider real-world data of the ANR-Info-RSN project, which deals with
community analysis in Twitter.


title: On the quasi-$\mathfrak{F}$-hypercenter of a finite group

abstract:
  In this paper some properties of the $\mathfrak{F}^*$-hypercenter of a finite
group are studied where $\mathfrak{F}^*$ is the class of all finite
quasi-$\mathfrak{F}$-groups for a hereditary saturated formation $\mathfrak{F}$
of finite groups. In particular, it is shown that the quasinilpotent
hypercenter of a finite group coincides with the intersection of all maximal
quasinilpotent subgroups.


title:
A Hamiltonian for the inclusion of spin effects in long-range Rydberg
  molecules

abstract:
  The interaction between a Rydberg electron and a neutral atom situated inside
its extended orbit is described via contact interactions for each atom-electron
scattering channel. In ultracold environments, these interactions lead to
ultra-long-range molecular states with binding energies typically ranging from
$10$-$10^4$MHz. These energies are comparable to the relativistic and hyperfine
structure of the separate atomic components. Studies of molecular formation
aiming to reproduce observations with spectroscopic accuracy must therefore
include the hyperfine splitting of the neutral atom and the spin-orbit
splittings of both the Rydberg atom and the electron-atom interaction.
Adiabatic potential energy curves that fully include these additional effects
are presented for Rb$_2$ and Cs$_2$. The influence of spin degrees of freedom
on the potential energy curves and molecular multipole moments probed in recent
experimental work is elucidated and contrasted with other recent theoretical
effort in this direction.


title:
Error analysis of projection methods for non inf-sup stable mixed finite
  elements. The Navier-Stokes equations

abstract:
  We obtain error bounds for a modified Chorin-Teman (Euler non-incremental)
method for non inf-sup stable mixed finite elements applied to the evolutionary
Navier-Stokes equations. The analysis of the classical Euler non-incremental
method is obtained as a particular case. We prove that the modified Euler
non-incremental scheme has an inherent stabilization that allows the use of non
inf-sup stable mixed finite elements without any kind of extra added
stabilization. We show that it is also true in the case of the classical
Chorin-Temam method. The relation of the methods with the so called pressure
stabilized Petrov Galerkin method (PSPG) is established. We do not assume
non-local compatibility conditions for the solution.


title:
Error analysis of projection methods for non inf-sup stable mixed finite
  elements. The transient Stokes problem

abstract:
  A modified Chorin-Teman (Euler non-incremental) projection method and a
modified Euler incremental projection method for non inf-sup stable mixed
finite elements are analyzed. The analysis of the classical Euler
non-incremental and Euler incremental methods are obtained as a particular
case. We first prove that the modified Euler non-incremental scheme has an
inherent stabilization that allows the use of non inf-sup stable mixed finite
elements without any kind of extra added stabilization. We show that it is also
true in the case of the classical Chorin-Temam method. For the second scheme,
we study a stabilization that allows the use of equal-order pairs of finite
elements. The relation of the methods with the so called pressure stabilized
Petrov Galerkin method (PSPG) is established. The influence of the chosen
initial approximations in the computed approximations to the pressure is
analyzed. Numerical tests confirm the theoretical results.


title:
The Effect of Variability on X-Ray Binary Luminosity Functions: Multiple
  Epoch Observations of NGC 300 with Chandra

abstract:
  We have obtained three epochs of Chandra ACIS-I observations (totaling
$\sim$184 ks) of the nearby spiral galaxy NGC~300 to study the logN-logS
distributions of its X-ray point source population down to
$\sim$2$\times$10$^{-15}$ erg s$^{-1}$ cm$^{-2}$ in the 0.35-8 keV band
(equivalent to $\sim$10$^{36}$ erg s$^{-1}$). The individual epoch logN-logS
distributions are best described as the sum of a background AGN component, a
simple power law, and a broken power law, with the shape of the logN-logS
distributions sometimes varying between observations. The simple power law and
AGN components produce a good fit for "persistent" sources (i.e., with fluxes
that remain constant within a factor of $\sim$2). The differential power law
index of $\sim$1.2 and high fluxes suggest that the persistent sources
intrinsic to NGC~300 are dominated by Roche lobe overflowing low mass X-ray
binaries. The variable X-ray sources are described by a broken power law, with
a faint-end power law index of $\sim$1.7, a bright-end index of $\sim$2.8-4.9,
and a break flux of $\sim$8$\times10^{-15}$ erg s$^{-1}$ cm$^{-2}$
($\sim$4$\times10^{36}$ erg s$^{-1}$), suggesting they are mostly outbursting,
wind-fed high mass X-ray binaries, although the logN-logS distribution of
variable sources likely also contains low-mass X-ray binaries. We generate
model logN-logS distributions for synthetic X-ray binaries and constrain the
distribution of maximum X-ray fluxes attained during outburst. Our observations
suggest that the majority of outbursting X-ray binaries occur at sub-Eddington
luminosities, where mass transfer likely occurs through direct wind accretion
at $\sim$1-3% of the Eddington rate.


title:
Electronic Band Structure of Transition Metal Dichalcogenides from Ab
  Initio and Slater-Koster Tight-Binding Model

abstract:
  Semiconducting transition metal dichalcogenides present a complex electronic
band structure with a rich orbital contribution to their valence and conduction
bands. The possibility to consider the electronic states from a tight-binding
model is highly useful for the calculation of many physical properties, for
which first principle calculations are more demanding in computational terms
when having a large number of atoms. Here, we present a set of Slater-Koster
parameters for a tight-binding model that accurately reproduce the structure
and the orbital character of the valence and conduction bands of single layer
MX$_2$, where M = Mo,Wand X = S, Se. The fit of the analytical tight-binding
Hamiltonian is done based on band structure from ab initio calculations. The
model is used to calculate the optical conductivity of the different compounds
from the Kubo formula.


title:
Strong approximations for the $p$-fold integrated empirical process with
  applications to statistical tests

abstract:
  The main purpose of this paper is to investigate the strong approximation of
the $p$-fold integrated empirical process, $p$ being a fixed positive integer.
More precisely, we obtain the exact rate of the approximations by a sequence of
weighted Brownian bridges and a weighted Kiefer process. Our arguments are
based in part on results of Koml\'os, Major and Tusn\'ady (1975). We also
obtain an exponential bound for the tail probability of the weighted
approximation to the $p$-fold integrated empirical process. Applications
include the two-sample testing procedures together with the change-point
problems. We also consider the strong approximation of integrated empirical
processes when the parameters are estimated. We study the behavior of the
self-intersection local time of the partial sum process representation of
integrated empirical processes. Finally, simulation results are provided to
illustrate the finite sample performance of the proposed statistical tests
based on the integrated empirical processes.


title:
The Temporal and Spatial Evolution of Momentum, Kinetic Energy and Force
  in Tsunami Waves during Breaking and Inundation

abstract:
  A plethora of studies in the past decade describe tsunami hazards and study
their evolution from the source to the target coastline, but mainly focus on
coastal inundation and maximum runup. Nonetheless, anecdotal reports from
eyewitnesses, photographs and videos suggest counterintuitive flow dynamics,
for example rapid initial acceleration when the wave first strikes the initial
shoreline. Further, the details of the flow field at or within tens of meters
of the shoreline are exquisitely important in determining damage to structures
and evacuation times. Based on a set of three-dimensional numerical simulations
using solitary waves as a model, we show the spatial-temporal distribution of
the flow momentum, kinetic energy and force during the breaking process. We
infer that the flow reaches its highest destructive capacity not when flow
momentum or kinetic energy reach their maxima, but when flow force reaches its.
This occurs in the initial shoreline environment, which needs to be considered
in nearshore structures design.


title:
On the lack of compactness and existence of maximizers for some
  Airy-Strichartz inequalities

abstract:
  This work is devoted to prove a linear profile decomposition for the Airy
equation in $\dot{H}_x^{s_k}(\mathbb{R})$, where $s_k=(k-4)/2k$ and $k>4$. We
also apply this decomposition to establish the existence of maximizers for a
general class of Strichartz type inequalities associated to the Airy equation.


title: Primordial gravitational waves in supersolid inflation

abstract:
  Supersolid inflation is a class of inflationary theories that simultaneously
breaks time and space reparameterization invariance during inflation, with
distinctive features for the dynamics of cosmological fluctuations. We
investigate concrete realizations of such a scenario, including non-minimal
couplings between gravity and the fields driving inflation. We focus in
particular on the dynamics of primordial gravitational waves and discuss how
their properties depend on the pattern of symmetry breaking that we consider.
Tensor modes can have a blue spectrum, and for the first time we build models
in which the squeezed limit of primordial tensor bispectra can be
parametrically enhanced with respect to standard single-field scenarios. At
leading order in a perturbative expansion, the tensor-to-scalar ratio depends
only on the parameter controlling the breaking of space-reparameterization. It
is independent from the quantities controlling the breaking of
time-reparameterization, and this represents a difference with respect to
standard single-field inflationary models.


title:
A minimal empirical model for the cosmic far-infrared background
  anisotropies

abstract:
  Cosmic far-infrared background (CFIRB) probes unresolved dusty star-forming
galaxies across cosmic time and is complementary to ultraviolet and optical
observations of galaxy evolution. In this work, we interpret the observed CFIRB
anisotropies using an empirical model based on resolved galaxies in ultraviolet
and optical surveys. Our model includes stellar mass functions, star-forming
main sequence, and dust attenuation. We find that the commonly used linear
Kennicutt relation between infrared luminosity and star formation rate
overproduces the observed CFIRB amplitudes. The observed CFIRB requires that
low-mass galaxies have lower infrared luminosities than expected from the
Kennicutt relation, implying that low-mass galaxies have lower dust content and
weaker dust attenuation. Our results demonstrate that CFIRB not only provides a
stringent consistency check for galaxy evolution models but also constrains the
dust content of low-mass galaxies.


title: Exploring Novel Quantum Criticality in Strained Graphene

abstract:
  Strain tuning is increasingly being recognized as a clean tuning parameter to
induce novel behavior in quantum matter. Motivated by the possibility of
straining graphene up to $20$ percent, we investigate novel quantum criticality
due to interplay between strain-induced anisotropic band structure and critical
antiferromagnetic spin fluctuations (AFSF) in this setting. We detail how this
interplay drives $(i)$ a quantum phase transition (QPT) between the
Dirac-semimetal-incoherent pseudogapped metal-correlated insulator as a
function of strain ($\epsilon$), and $(ii)$ critical AFSF-driven divergent
nematic susceptibility near critical strain ($\epsilon_{c}$) manifesting as
critical singularities in magneto-thermal expansion and Gr\"uneisen
co-efficients. The correlated band insulator at large strain affords
realization of a two-dimensional dimerized spin-singlet state due to this
interplay, and we argue how doping such an insulator can lead to a spin-charge
separated metal, leading to anomalous metallicity and possible unconventional
superconductivity. On a wider front, our work serves to illustrate the range of
novel states realizable by strain-tuning quantum materials.


title:
Fast Task-Specific Target Detection via Graph Based Constraints
  Representation and Checking

abstract:
  In this work, we present a fast target detection framework for real-world
robotics applications. Considering that an intelligent agent attends to a
task-specific object target during execution, our goal is to detect the object
efficiently. We propose the concept of early recognition, which influences the
candidate proposal process to achieve fast and reliable detection performance.
To check the target constraints efficiently, we put forward a novel policy to
generate a sub-optimal checking order, and prove that it has bounded time cost
compared to the optimal checking sequence, which is not achievable in
polynomial time. Experiments on two different scenarios: 1) rigid object and 2)
non-rigid body part detection validate our pipeline. To show that our method is
widely applicable, we further present a human-robot interaction system based on
our non-rigid body part detection.


title:
Normalizing the Normalizers: Comparing and Extending Network
  Normalization Schemes

abstract:
  Normalization techniques have only recently begun to be exploited in
supervised learning tasks. Batch normalization exploits mini-batch statistics
to normalize the activations. This was shown to speed up training and result in
better models. However its success has been very limited when dealing with
recurrent neural networks. On the other hand, layer normalization normalizes
the activations across all activities within a layer. This was shown to work
well in the recurrent setting. In this paper we propose a unified view of
normalization techniques, as forms of divisive normalization, which includes
layer and batch normalization as special cases. Our second contribution is the
finding that a small modification to these normalization schemes, in
conjunction with a sparse regularizer on the activations, leads to significant
benefits over standard normalization techniques. We demonstrate the
effectiveness of our unified divisive normalization framework in the context of
convolutional neural nets and recurrent neural networks, showing improvements
over baselines in image classification, language modeling as well as
super-resolution.


title:
Simple embedding scheme for the spectral properties of the
  Single-Impurity Anderson Model

abstract:
  In this work we outline a simple and numerically inexpensive approach to
describe the spectral features of the single-impurity Anderson model. The
method combines aspects of the density matrix embedding theory (DMET) approach
with a spectral broadening approach inspired by those used in numerical
renormalization group (NRG) methods. At zero temperature for a wide range of U
, the spectral function produced by this approach is found to be in good
agreement with general expectations as well as more advanced and complex
numerical methods such as DMRG-based schemes. The theory developed here is
simply transferable to more complex impurity problems.


title: Non-equilibration of topological charge and its effects

abstract:
  In QCD simulations at small lattice spacings, the topological charge Q
evolves very slowly and, if this quantity is not properly equilibrated, we
could get incorrect results for physical quantities, or incorrect estimates of
their errors. We use the known relation between the dependence of masses and
decay constants on the QCD vacuum angle theta and the squared topological
charge Q^2 together with chiral perturbation theory results for the dependence
of masses and decay constants on theta to estimate the size of these effects
and suggest strategies for dealing with them. For the partially quenched case,
we sketch an alternative derivation of the known $\chi$PT results of Aoki and
Fukaya, using the nonperturbatively correct chiral theory worked out by
Golterman, Sharpe and Singleton, and by Sharpe and Shoresh. With the MILC
collaboration's ensembles of lattices with four flavors of HISQ dynamical
quarks, we measure the $Q^2$ dependence of masses and decay constants and
compare to the $\chi$PT forms. The observed agreement gives us confidence that
we can reliably estimate the errors from slow topology change, and even correct
for its leading effects.


title: Symmetric correspondences on quadrics

abstract:
  We prove a result comparing the rationality of some elementary algebraic
cycles introduced by Alexander Vishik, defined on orthogonal grassmannians,
with the rationality of some algebraic cycles defined on fiber products of the
corresponding quadric.


title: Group Activity Selection on Social Networks

abstract:
  We propose a new variant of the group activity selection problem (GASP),
where the agents are placed on a social network and activities can only be
assigned to connected subgroups. We show that if multiple groups can
simultaneously engage in the same activity, finding a stable outcome is easy as
long as the network is acyclic. In contrast, if each activity can be assigned
to a single group only, finding stable outcomes becomes intractable, even if
the underlying network is very simple: the problem of determining whether a
given instance of a GASP admits a Nash stable outcome turns out to be NP-hard
when the social network is a path, a star, or if the size of each connected
component is bounded by a constant. On the other hand, we obtain
fixed-parameter tractability results for this problem with respect to the
number of activities.


title:
Solar Corona Thermal Background and Energy Spectrum of the Weak Solar
  Soft X-ray Bursts

abstract:
  The energy spectrum of the weak solar soft X-ray bursts are investigated
using the data of the Interball project.


title: Extragalactic photon-ALP conversion at CTA energies

abstract:
  Magnetic fields in extragalactic space between galaxy clusters may induce
conversions between photons and axion-like particles (ALPs), thereby shielding
the photons from absorption on the extragalactic background light. For TeV
gamma rays, the oscillation length ($l_{\rm osc}$) of the photon-ALP system
becomes inevitably of the same order as the coherence length of the magnetic
field ($l$) and the length over which the field changes significantly
(transition length $l_{\rm t}$) due to refraction on background photons. We
derive exact statistical evolution equations for the mean and variance of the
photon and ALP transfer functions in the non-adiabatic regime ($l_{\rm osc}
\sim l \gg l_{\rm t}$). We also make analytical predictions for the transfer
functions in the quasi-adiabatic regime ($l_{\rm osc} \ll l, l_{\rm t}$). Our
results are important in light of the upcoming Cherenkov Telescope Array (CTA),
and may also be applied to models with non-zero ALP masses.


title:
Roth's solvability criteria for the matrix equations ${AX-\widehat
  XB=C}$ and ${X-A\widehat{X}B=C}$ over the skew field of quaternions with an
  involutive automorphism $q\mapsto \hat q$

abstract:
  The matrix equation $AX-XB=C$ has a solution if and only if the matrices
[A&C\\0&B] and [A &0\\0 & B] are similar. This criterion was proved over a
field by W.E. Roth (1952) and over the skew field of quaternions by Huang
Liping (1996). H.K. Wimmer (1988) obtained an analogous criterion for the
matrix equation $X-AXB=C$ over a field. We extend these criteria to the matrix
equations $AX-\widehat XB=C$ and $X-A\widehat XB=C$ over the skew field of
quaternions with a fixed involutive automorphism $q\mapsto \hat q$.


title:
Benchmarking Quantum Hardware for Training of Fully Visible Boltzmann
  Machines

abstract:
  Quantum annealing (QA) is a hardware-based heuristic optimization and
sampling method applicable to discrete undirected graphical models. While
similar to simulated annealing, QA relies on quantum, rather than thermal,
effects to explore complex search spaces. For many classes of problems, QA is
known to offer computational advantages over simulated annealing. Here we
report on the ability of recent QA hardware to accelerate training of fully
visible Boltzmann machines. We characterize the sampling distribution of QA
hardware, and show that in many cases, the quantum distributions differ
significantly from classical Boltzmann distributions. In spite of this
difference, training (which seeks to match data and model statistics) using
standard classical gradient updates is still effective. We investigate the use
of QA for seeding Markov chains as an alternative to contrastive divergence
(CD) and persistent contrastive divergence (PCD). Using $k=50$ Gibbs steps, we
show that for problems with high-energy barriers between modes, QA-based seeds
can improve upon chains with CD and PCD initializations. For these hard
problems, QA gradient estimates are more accurate, and allow for faster
learning. Furthermore, and interestingly, even the case of raw QA samples (that
is, $k=0$) achieved similar improvements. We argue that this relates to the
fact that we are training a quantum rather than classical Boltzmann
distribution in this case. The learned parameters give rise to hardware QA
distributions closely approximating classical Boltzmann distributions that are
hard to train with CD/PCD.


title:
Can information be spread as a virus? Viral Marketing as epidemiological
  model

abstract:
  In epidemiology, an epidemic is defined as the spread of an infectious
disease to a large number of people in a given population within a short period
of time. In the marketing context, a message is viral when it is broadly sent
and received by the target market through person-to-person transmission. This
specific marketing communication strategy is commonly referred as viral
marketing. Due to this similarity between an epidemic and the viral marketing
process and because the understanding of the critical factors to this
communications strategy effectiveness remain largely unknown, the mathematical
models in epidemiology are presented in this marketing specific field. In this
paper, an epidemiological model SIR (Susceptible- Infected-Recovered) to study
the effects of a viral marketing strategy is presented. It is made a comparison
between the disease parameters and the marketing application, and Matlab
simulations are performed. Finally, some conclusions are carried out and their
marketing implications are exposed: interactions across the parameters suggest
some recommendations to marketers, as the profitability of the investment or
the need to improve the targeting criteria of the communications campaigns.


title:
A classification of totally geodesic and totally umbilical Legendrian
  submanifolds of $(\kappa,\mu)$-spaces

abstract:
  We present classifications of totally geodesic and totally umbilical
Legendrian submanifolds of $(\kappa,\mu)$-spaces with Boeckx invariant $I \leq
-1$. In particular, we prove that such submanifolds must be, up to local
isometries, among the examples that we explicitly construct.


title: Retrofit Control: Localization of Controller Design and Implementation

abstract:
  In this paper, we propose a retrofit control method for stable network
systems. The proposed approach is a control method that, rather than an entire
system model, requires a model of the subsystem of interest for controller
design. To design the retrofit controller, we use a novel approach based on
hierarchical state-space expansion that generates a higher-dimensional cascade
realization of a given network system. The upstream dynamics of the cascade
realization corresponds to an isolated model of the subsystem of interest,
which is stabilized by a local controller. The downstream dynamics can be seen
as a dynamical model representing the propagation of interference signals among
subsystems, the stability of which is equivalent to that of the original
system. This cascade structure enables a systematic analysis of both the
stability and control performance of the resultant closed-loop system. The
resultant retrofit controller is formed as a cascade interconnection of the
local controller and an output rectifier that rectifies an output signal of the
subsystem of interest so as to conform to an output signal of the isolated
subsystem model while acquiring complementary signals neglected in the local
controller design, such as interconnection signals from neighboring subsystems.
Finally, the efficiency of the retrofit control method is demonstrated through
numerical examples of power systems control and vehicle platoon control.


title:
High-energy emission from non-relativistic radiative shocks: application
  to gamma-ray novae

abstract:
  Multiwavelength radiation from relativistic particles accelerated at shocks
in novae and other astrophysical sources carries a wealth of information about
the outflow properties and the microphysical processes at work near the shocks.
The observation of GeV gamma-rays from novae by Fermi/LAT demonstrates that the
shocks in these systems can accelerate particles to energies of at least $\sim
10$ GeV. The low-energy extension of the same non-thermal particle distribution
inevitably gives rise to emission extending into the X-ray band. Above $\gtrsim
10$ keV this radiation can escape the system without significant
absorption/attenuation, and can potentially be detected by NuSTAR. We present
theoretical models for hard X-ray and gamma-ray emission from radiative shocks
in both leptonic and hadronic scenarios, accounting for the rapid evolution of
the downstream properties due to the fast cooling of thermal plasma. Due to
strong Coulomb cooling of the mildly relativistic electrons nominally
responsible for producing hard X-ray emission, only a fraction of $10^{-4} -
10^{-3}$ of the gamma-ray luminosity is radiated in the NuSTAR band;
nevertheless, this emission could be detectable simultaneous with the LAT
emission in bright gamma-ray novae with a $\sim 50$ ks exposure. Our work
demonstrates how combined hard X-ray and gamma-ray observations can be used to
constrain properties of the nova outflow (velocity, density and mass outflow
rate) and particle acceleration at the shock. A very low X-ray to gamma-ray
luminosity ratio ($L_{\rm X}/L_{\gamma} \lesssim 5 \times 10^{-4}$) would
disfavor leptonic models for the gamma-ray emission. Our model can also be
applied to other astrophysical environments with radiative shocks, including
Type IIn supernovae and colliding winds in massive star binaries.


title:
Darboux integrable system with a triple point and pseudo-abelian
  integrals

abstract:
  In this paper we consider the degeneracies of the third type. More exact, the
perturbations of the Darboux integrable foliation with a triple point, i.e. the
case where three of the curves $\{P_i = 0\}$ meet at one point, are considered.
Assuming that this is the only non-genericity, we prove that the number of
zeros of the corresponding pseudo-abelian integrals is bounded uniformly for
close Darboux integrable foliations. Let $\mathcal{F}$ denote the foliation
with triple point (assume it to be at the origin), and let $\mathcal{F}_\lambda
= \{M_\lambda {dH_\lambda \over H_\lambda} = 0\}$, $M_\lambda$ is a integrating
factor, be the close foliation. The main problem is that $\mathcal{F}_\lambda$
can have a small nest of cycles which shrinks to the origin as $\lambda\to 0$.
A particular case of this situation, namely $H_\lambda = (x -\lambda)^\epsilon
(y - x)^{\epsilon_+} (y + x)^{\epsilon_-}\Delta$ with $\Delta$ non-vanishing at
the origin (and generic in appropriate sense).


title: 3-D Convolutional Neural Networks for Glioblastoma Segmentation

abstract:
  Convolutional Neural Networks (CNN) have emerged as powerful tools for
learning discriminative image features. In this paper, we propose a framework
of 3-D fully CNN models for Glioblastoma segmentation from multi-modality MRI
data. By generalizing CNN models to true 3-D convolutions in learning 3-D tumor
MRI data, the proposed approach utilizes a unique network architecture to
decouple image pixels. Specifically, we design a convolutional layer with
pre-defined Difference- of-Gaussian (DoG) filters to perform true 3-D
convolution incorporating local neighborhood information at each pixel. We then
use three trained convolutional layers that act to decouple voxels from the
initial 3-D convolution. The proposed framework allows identification of
high-level tumor structures on MRI. We evaluate segmentation performance on the
BRATS segmentation dataset with 274 tumor samples. Extensive experimental
results demonstrate encouraging performance of the proposed approach comparing
to the state-of-the-art methods. Our data-driven approach achieves a median
Dice score accuracy of 89% in whole tumor glioblastoma segmentation, revealing
a generalized low-bias possibility to learn from medium-size MRI datasets.


title:
Learning-Theoretic Foundations of Algorithm Configuration for
  Combinatorial Partitioning Problems

abstract:
  Max-cut, clustering, and many other partitioning problems that are of
significant importance to machine learning and other scientific fields are
NP-hard, a reality that has motivated researchers to develop a wealth of
approximation algorithms and heuristics. Although the best algorithm to use
typically depends on the specific application domain, a worst-case analysis is
often used to compare algorithms. This may be misleading if worst-case
instances occur infrequently, and thus there is a demand for optimization
methods which return the algorithm configuration best suited for the given
application's typical inputs. We address this problem for clustering, max-cut,
and other partitioning problems, such as integer quadratic programming, by
designing computationally efficient and sample efficient learning algorithms
which receive samples from an application-specific distribution over problem
instances and learn a partitioning algorithm with high expected performance.
Our algorithms learn over common integer quadratic programming and clustering
algorithm families: SDP rounding algorithms and agglomerative clustering
algorithms with dynamic programming. For our sample complexity analysis, we
provide tight bounds on the pseudodimension of these algorithm classes, and
show that surprisingly, even for classes of algorithms parameterized by a
single parameter, the pseudo-dimension is superconstant. In this way, our work
both contributes to the foundations of algorithm configuration and pushes the
boundaries of learning theory, since the algorithm classes we analyze consist
of multi-stage optimization procedures and are significantly more complex than
classes typically studied in learning theory.


title: Role of the strange quark in the rho(770) meson

abstract:
  Recently, the GWU lattice group has evaluated high-precision phase-shift data
for $\pi\pi$ scattering in the $I = 1$, $J = 1$ channel. Unitary Chiral
Perturbation Theory describes these data well around the resonance region and
for different pion masses. Moreover, it allows to extrapolate to the physical
point and estimate the effect of the missing $K\bar{K}$ channel in the
two-flavor lattice calculation. The absence of the strange quark in the lattice
data leads to a lower $\rho$ mass, and the analysis with U$\chi$PT shows that
the $K \bar{K}$ channel indeed pushes the $\pi\pi$-scattering phase shift
upward, having a surprisingly large effect on the $\rho$-mass. The inelasticity
is shown to be compatible with the experimental data. The analysis is then
extended to all available two-flavor lattice simulations and similar mass
shifts are observed. Chiral extrapolations of $N_f = 2 + 1$ lattice simulations
for the $\rho(770)$ are also reported.


title: Multiscale scanning in inverse problems

abstract:
  In this paper we propose a multiscale scanning method to determine active
components of a quantity $f$ w.r.t. a dictionary $\mathcal{U}$ from
observations $Y$ in an inverse regression model $Y=Tf+\xi$ with linear operator
$T$ and general random error $\xi$. To this end, we provide uniform confidence
statements for the coefficients $\langle \varphi, f\rangle$, $\varphi \in
\mathcal U$, under the assumption that $(T^*)^{-1} \left(\mathcal U\right)$ is
of wavelet-type. Based on this we obtain a multiple test that allows to
identify the active components of $\mathcal{U}$, i.e. $\left\langle f,
\varphi\right\rangle \neq 0$, $\varphi \in \mathcal U$, at controlled,
family-wise error rate. Our results rely on a Gaussian approximation of the
underlying multiscale statistic with a novel scale penalty adapted to the
ill-posedness of the problem. The scale penalty furthermore ensures weak
convergence of the statistic's distribution towards a Gumbel limit under
reasonable assumptions. The important special cases of tomography and
deconvolution are discussed in detail. Further, the regression case, when $T =
\text{id}$ and the dictionary consists of moving windows of various sizes
(scales), is included, generalizing previous results for this setting. We show
that our method obeys an oracle optimality, i.e. it attains the same asymptotic
power as a single-scale testing procedure at the correct scale. Simulations
support our theory and we illustrate the potential of the method as an
inferential tool for imaging. As a particular application we discuss
super-resolution microscopy and analyze experimental STED data to locate single
DNA origami.

categories: stat.ME math.NA math.OC math.ST stat.AP stat.TH


title: Recursive partitioning and multi-scale modeling on conditional densities

abstract:
  We introduce a nonparametric prior on the conditional distribution of a
(univariate or multivariate) response given a set of predictors. The prior is
constructed in the form of a two-stage generative procedure, which in the first
stage recursively partitions the predictor space, and then in the second stage
generates the conditional distribution by a multi-scale nonparametric density
model on each predictor partition block generated in the first stage. This
design allows adaptive smoothing on both the predictor space and the response
space, and it results in the full posterior conjugacy of the model, allowing
exact Bayesian inference to be completed analytically through a
forward-backward recursive algorithm without the need of MCMC, and thus
enjoying high computational efficiency (scaling linearly with the sample size).
We show that this prior enjoys desirable theoretical properties such as full
$L_1$ support and posterior consistency. We illustrate how to apply the model
to a variety of inference problems such as conditional density estimation as
well as hypothesis testing and model selection in a manner similar to applying
a parametric conjugate prior, while attaining full nonparametricity. Also
provided is a comparison to two other state-of-the-art Bayesian nonparametric
models for conditional densities in both model fit and computational time. A
real data example from flow cytometry containing 455,472 observations is given
to illustrate the substantial computational efficiency of our method and its
application to multivariate problems.


title: Good Integers and Applications in Coding Theory

abstract:
  A class of good integers has been introduced by P. Moree in $1997$ together
with the characterization of good odd integers. Such integers have shown to
have nice number theoretical properties and wide applications. In this paper, a
complete characterization of all good integers is given.
  Two subclasses of good integers are introduced, namely, oddly-good and
evenly-good integers. The characterization and properties of good integers in
these two subclasses are determined.
  As applications, good integers and oddly-good integers are applied in the
study of the hulls of abelian codes. The average dimension of the hulls of
abelian codes is given together with some upper and lower bounds.


title: The Mount Wilson Observatory S-index of the Sun

abstract:
  The most commonly used index of stellar magnetic activity is the instrumental
flux scale of singly-ionized calcium H & K line core emission, S, developed by
the Mount Wilson Observatory (MWO) HK Project, or the derivative index R'_HK.
Accurately placing the Sun on the S scale is important for comparing solar
activity to that of the Sun-like stars. We present previously unpublished
measurements of the reflected sunlight from the Moon using the
second-generation MWO HK photometer during solar cycle 23 and determine cycle
minimum S_min,23 = 0.1634 +/- 0.0008, amplitude Delta S_23 = 0.0143 +/- 0.0012,
and mean <S_23> = 0.1701 +/- 0.0005. By establishing a proxy relationship with
the closely related National Solar Observatory Sacramento Peak calcium K
emission index, itself well-correlated with the Kodaikanal Observatory plage
index, we extend the MWO S time series to cover cycles 15-24 and find on
average <S_min> = 0.1621 +/- 0.0008, <Delta S_cyc> = 0.0145 +/- 0.0012, <S_cyc>
= 0.1694 +/- 0.0005. Our measurements represent an improvement over previous
estimates which relied on stellar measurements or solar proxies with
non-overlapping time series. We find good agreement from these results with
measurements by the Solar-Stellar Spectrograph at Lowell Observatory, an
independently calibrated instrument, which gives us additional confidence that
we have accurately placed the Sun on the S-index flux scale.


title:
Probing the pairing interaction and multiple Bardasis-Schrieffer modes
  using Raman spectroscopy

abstract:
  In unconventional superconductors, understanding the form of the pairing
interaction is the primary goal. In this regard, Raman spectroscopy is a very
useful tool, as it identifies the ground state and also the subleading pairing
channels by probing collective modes. Here we propose a general theory for
multiband Raman response and identify new features in the spectrum that can
provide a robust test for a pairing theory. We identify multiple
Bardasis-Schrieffer type collective modes and connect the weights of these
modes to the sub-leading gap structures within a microscopic pairing theory.
The conclusions are completely general, and we apply our approach to interpret
the B1g Raman scattering in hole-doped BaFe2As2.


title:
Coherence and Entanglement Monogamy in the Discrete Analogue of Analog
  Grover Search

abstract:
  Grover's search algorithm is the optimal quantum algorithm that can search an
unstructured database quadratically faster than any known classical algorithm.
The role of entanglement and correlations in the search algorithm have been
studied in great detail and it is known that entanglement between the qubits is
necessary to gain a quadratic speedup, for pure state implementation of the
Grover search algorithm. Here, we systematically investigate the behavior of
quantum coherence and monogamy of entanglement in the discrete analogue of the
$\textit{analog analogue of Grover search algorithm}$. The analog analogue of
Grover search is a continuous time quantum algorithm based on the adiabatic
Hamiltonian evolution that gives a quadratic speedup, similar to the original
Grover search algorithm. We show that the decrease of quantum coherence,
quantified using various coherence monotones, is a clear signature of attaining
the maximum success probability in the analog Grover search. We also show that
for any two qubit reduced density matrix of the system, the concurrence evolves
in close vicinity to the increasing rate of success probability. Furthermore,
we show that the system satisfies a $n$-party monogamy inequality for arbitrary
times, hence bounding the amount of $n$-qubit entanglement during the quantum
search.


title: Discontinuous polaron transition in a two-band model

abstract:
  We present exact diagonalization and momentum average approximation (MA)
results for the single polaron properties of a one-dimensional two-band model
with phonon-modulated hopping. At strong electron-phonon coupling, we find a
novel type of sharp transition, where the polaron ground state momentum jumps
discontinuously from $k=\pi$ to $k=0$. The nature and origin of this transition
is investigated and compared to that of the Su-Schrieffer-Heeger (SSH) model,
where a sharp but smooth transition was previously reported. We argue that such
discontinuous transitions are a consequence of the multi-band nature of the
model, and are unlikely to be observed in one-band models. We also show that MA
describes qualitatively and even quantitatively accurately this polaron and its
transition. Given its computationally efficient generalization to higher
dimensions, MA thus promises to allow for accurate studies of electron-phonon
coupling in multi-band models in higher dimensions.


title:
On the strong Lefschetz question for uniform powers of general linear
  forms in $k[x,y,z]$

abstract:
  Schenck and Seceleanu proved that if $R = k[x,y,z]$, where $k$ is an infinite
field, and $I$ is an ideal generated by any collection of powers of linear
forms, then multiplication by a general linear form $L$ induces a homomorphism
of maximal rank from any component of $R/I$ to the next. That is, $R/I$ has the
{\em weak Lefschetz property}. Considering the more general {\em strong
Lefschetz question} of when $\times L^j$ has maximal rank for $j \geq 2$, we
give the first systematic study of this problem. We assume that the linear
forms are general and that the powers are all the same, i.e. that $I$ is
generated by {\em uniform} powers of general linear forms. We prove that for
any number of such generators, $\times L^2$ always has maximal rank. We then
specialize to almost complete intersections, i.e. to four generators, and we
show that for $j = 3,4,5$ the behavior depends on the uniform exponent and on
$j$, in a way that we make precise. In particular, there is always at most one
degree where $\times L^j$ fails maximal rank. Finally, we note that
experimentally all higher powers of $L$ fail maximal rank in at least two
degrees.


title:
Inflation and late time acceleration designed by Stueckelberg massive
  photon

abstract:
  We present a mini review of the Stueckelberg mechanism, which was proposed to
make the abelian gauge theories massive as an alternative to Higgs mechanism,
within the framework of Minkowski as well as curved spacetimes. The higher the
scale the tighter the bounds on the photon mass, which might be gained via the
Stueckelberg mechanism, may be signalling that even an extremely small mass of
the photon which cannot be measured directly could have far reaching effects in
cosmology. We present a cosmological model where Stueckelberg fields, which
consist of both scalar and vector fields, are non-minimally coupled to gravity
and the universe could go through a decelerating expansion phase sandwiched by
two different accelerated expansion phases. We discuss also the possible
anisotropic extensions of the model.


title:
A better bound on the largest induced forests in triangle-free planar
  graphs

abstract:
  It is well-known that there exists a triangle-free planar graph of $n$
verticess such that the largest induced forest has size at most $\frac{5n}{8}$.
Salavatipour proved that there is a forest of size at least $\frac{5n}{9.41}$
in any triangle-free planar graph of $n$ vertices. Dross, Montassier and Pinlou
improved Salavatipour's bound to $\frac{5n}{9.17}$. In this work, we further
improve the bound to $\frac{5n}{9}$. Our technique is inspired by the recent
ideas from Lukot'ka, Maz{\'a}k and Zhu.


title:
Phase transitions in long-range Ising models and an optimal condition
  for factors of $g$-measures

abstract:
  We weaken the assumption of summable variations in a paper by Verbitskiy
\cite{verb} to a weaker condition, Berbee's condition, in order for a 1-block
factor (a single site renormalisation) of the full shift space on finitely many
symbols to have a $g$-measure with a continuous $g$-function. But we also prove
by means of a counterexample, that this condition is (within constants)
optimal. The counterexample is based on the second of our main results, where
we prove that there is an inverse critical temperature in a one-sided
long-range Ising model which is at most 8 times the critical inverse
temperature for the (two-sided) Ising model with long-range interactions.


title: Real Stable Polynomials and Matroids: Optimization and Counting

abstract:
  A great variety of fundamental optimization and counting problems arising in
computer science, mathematics and physics can be reduced to one of the
following computational tasks involving polynomials and set systems: given an
$m$-variate real polynomial $g$ and a family of subsets $B$ of $[m]$, (1) find
$S\in B$ such that the monomial in $g$ corresponding to $S$ has the largest
coefficient in $g$, or (2) compute the sum of coefficients of monomials in $g$
corresponding to all the sets in $B$. Special cases of these problems, such as
computing permanents, sampling from DPPs and maximizing subdeterminants have
been topics of recent interest in theoretical computer science.
  In this paper we present a general convex programming framework geared to
solve both of these problems. We show that roughly, when $g$ is a real stable
polynomial with non-negative coefficients and $B$ is a matroid, the integrality
gap of our relaxation is finite and depends only on $m$ (and not on the
coefficients of g).
  Prior to our work, such results were known only in sporadic cases that relied
on the structure of $g$ and $B$; it was not even clear if one could formulate a
convex relaxation that has a finite integrality gap beyond these special cases.
Two notable examples are a result by Gurvits on the van der Waerden conjecture
for real stable $g$ when $B$ is a single element and a result by Nikolov and
Singh for multilinear real stable polynomials when $B$ is a partition matroid.
Our work, which encapsulates most interesting cases of $g$ and $B$, benefits
from both - we were inspired by the latter in deriving the right convex
programming relaxation and the former in establishing the integrality gap.
However, proving our results requires significant extensions of both; in that
process we come up with new notions and connections between stable polynomials
and matroids which should be of independent interest.


title: MADMAX: A new Dark Matter Axion Search using a Dielectric Haloscope

abstract:
  The axion is an intriguing dark matter candidate emerging from the
Peccei-Quinn solution to the strong CP problem. Current experimental searches
for axion dark matter focus on the axion mass range below 40 $\mu$eV. However,
if the Peccei-Quinn symmetry is restored after inflation the observed dark
matter density points to an axion mass around 100 $\mu$eV. A new project based
on axion-photon conversion at the transition between different dielectric media
is presented. By using $\sim 80$ dielectric discs, the emitted power could be
enhanced by a factor of $\sim 10^5$ over that from a single mirror (flat dish
antenna). Within a 10 T magnetic field, this could be enough to detect $\sim
100 \mu$eV axions with HEMT linear amplifiers. The design for an experiment is
proposed. Results from noise, transmissivity and reflectivity measurements
obtained in a prototype setup are presented. The expected sensitivity is shown.


title: On the equivalence of models with similar low-energy quasiparticles

abstract:
  We use a Metropolis algorithm to calculate the finite temperature spectral
weight of three related models that have identical quasiparticles at $T=0$, if
the exchange favors the appearance of a ferromagnetic background. The
low-energy behavior of two of the models remains equivalent at finite
temperature, however that of the third does not because its low-energy behavior
is controlled by rare events due to thermal fluctuations, which transfer
spectral weight well below the $T=0$ quasiparticle peaks and generate a
pseudogap-like phenomenology. Our results demonstrate that having $T=0$ spectra
with similar quasiparticles is not a sufficient condition to ensure that two
models are equivalent, {\em i.e.} that their low-energy properties are similar.
We also argue that the pseudogap-like phenomenology is quite generic for models
of $t$-$J$ type, appearing in any dimension and for carriers injected into both
ferromagnetic and antiferromagnetic backgrounds.


title:
Comparing Skein and Quantum Group Representations and Their Application
  to Asymptotic Faithfulness

abstract:
  We generalize the asymptotic faithfulness of the skein quantum $SU(2)$
representations of mapping class groups of orientable closed surfaces to skein
$SU(3)$. Skein quantum representations of mapping class groups are different
from the Reshetikin-Turaev ones from quantum groups or geometric quantization
because they are given by different modular tensor categories. We conjecture
asymptotic faithfulness holds for skein quantum $G$ representations when $G$ is
a simply-connected simple Lie group. The difficulty for such a generalization
lies in the lack of an explicit description of the fusion spaces with
multiplicities to define an appropriate complexity of state vectors.


title: A Model-Predictive Motion Planner for the IARA Autonomous Car

abstract:
  We present the Model-Predictive Motion Planner (MPMP) of the Intelligent
Autonomous Robotic Automobile (IARA). IARA is a fully autonomous car that uses
a path planner to compute a path from its current position to the desired
destination. Using this path, the current position, a goal in the path and a
map, IARA's MPMP is able to compute smooth trajectories from its current
position to the goal in less than 50 ms. MPMP computes the poses of these
trajectories so that they follow the path closely and, at the same time, are at
a safe distance of eventual obstacles. Our experiments have shown that MPMP is
able to compute trajectories that precisely follow a path produced by a Human
driver (distance of 0.15 m in average) while smoothly driving IARA at speeds of
up to 32.4 km/h (9 m/s).


title:
Nonlinear Modal Decoupling of Multi-Oscillator Systems with Applications
  to Power Systems

abstract:
  Many natural and manmade dynamical systems that are modeled as large
nonlinear multi-oscillator systems like power systems are hard to analyze. For
such a system, we propose a nonlinear modal decoupling (NMD) approach inversely
constructing as many decoupled nonlinear oscillators as the system oscillation
modes so that individual decoupled oscillators can easily be analyzed to infer
dynamics and stability of the original system. The NMD follows a similar idea
to the normal form except that we eliminate inter-modal terms but allow
intra-modal terms of desired nonlinearities in decoupled systems, so decoupled
systems can flexibly be shaped into desired forms of nonlinear oscillators. The
NMD is then applied to power systems towards two types of nonlinear
oscillators, i.e. the single-machine-infinite-bus (SMIB) systems and a proposed
non-SMIB oscillator. Numerical studies on a 3-machine 9-bus system and New
England 10-machine 39-bus system show that (i) decoupled oscillators keep a
majority of the original system modal nonlinearities and the NMD provides a
bigger validity region than the normal form, and (ii) decoupled non-SMIB
oscillators may keep more authentic dynamics of the original system than
decoupled SMIB systems.


title: Optical potential from first principles

abstract:
  We develop a method to construct a microscopic optical potential from chiral
interactions for nucleon-nucleus scattering. The optical potential is
constructed by combining the Green's function approach with the coupled-cluster
method. To deal with the poles of the Green's function along the real energy
axis we employ a Berggren basis in the complex energy plane combined with the
Lanczos method. Using this approach, we perform a proof-of-principle
calculation of the optical potential for the elastic neutron scattering on
$^{16}{\rm O}$. For the computation of the ground-state of $^{16}{\rm O}$, we
use the coupled-cluster method in the singles-and-doubles approximation, while
for the $A=\pm 1$ nuclei we use particle-attached/removed equation-of-motion
method truncated at two-particle-one-hole and one-particle-two-hole
excitations, respectively. We verify the convergence of the optical potential
and scattering phase shifts with respect to the model-space size and the number
of discretized complex continuum states. We also investigate the absorptive
component of the optical potential (which reflects the opening of inelastic
channels) by computing its imaginary volume integral and find an almost
negligible absorptive component at low-energies. To shed light on this result,
we computed excited states of $^{16}{\rm O}$ using equation-of-motion
coupled-cluster method with singles-and-doubles excitations and we found no
low-lying excited states below 10~MeV. Furthermore, most excited states have a
dominant two-particle-two-hole component, making higher-order particle-hole
excitations necessary to achieve a precise description of these core-excited
states. We conclude that the reduced absorption at low-energies can be
attributed to the lack of correlations coming from the low-order cluster
truncation in the employed coupled-cluster method.


title:
Controlling placement of nonspherical (boomerang) colloids in nematic
  cells with photopatterned director

abstract:
  Placing colloidal particles in predesigned sites represents a major challenge
of the current state-of-the-art colloidal science. Nematic liquid crystals with
spatially varying director patterns represent a promising approach to achieve a
well-controlled placement of colloidal particles thanks to the elastic forces
between the particles and the surrounding landscape of molecular orientation.
Here we demonstrate how the spatially varying director field can be used to
control placement of non-spherical particles of boomerang shape. The boomerang
colloids create director distortions of a dipolar symmetry. When a boomerang
particle is placed in a periodic splay-bend director pattern, it migrates
towards the region of a maximum bend. The behavior is contrasted to that one of
spherical particles with normal surface anchoring, which also produce dipolar
director distortions, but prefer to compartmentalize into the regions with a
maximum splay. The splay-bend periodic landscape thus allows one to spatially
separate these two types of particles. By exploring overdamped dynamics of the
colloids, we determine elastic driving forces responsible for the preferential
placement. Control of colloidal locations through patterned molecular
orientation can be explored for future applications in microfluidic, lab on a
chip, sensing and sorting devices.


title:
Controlling the growth of Bi(110) and Bi(111) films on an insulating
  substrate

abstract:
  Here we demonstrate the controlled growth of Bi(110) and Bi(111) films on an
(insulating) $\alpha$-Al$_2$O$_3$(0001) substrate by surface X-ray diffraction
and X-ray reflectivity using synchrotron radiation. At temperatures as low as
40 K, unanticipated pseudo-cubic Bi(110) films are grown having a thickness
ranging from a few to tens of nanometers. The roughness at the film-vacuum as
well as at the film-substrate interface, can be reduced by mild heating, where
a crystallographic orientation transition of Bi(110) towards Bi(111) is
observed at 400 K. From 450 K onwards high quality and ultrasmooth Bi(111)
films are formed. Growth around the transition temperature results in the
growth of competing Bi(110) and Bi(111) thin film domains.


title: Quark Matter Equation of State from Perturbative QCD

abstract:
  In this proceedings contribution, we discuss recent developments in the
perturbative determination of the Equation of State of dense quark matter,
relevant for the microscopic description of neutron star cores. First, we
introduce the current state of the art in the problem, both at zero and small
temperatures, and then present results from two recent perturbative studies
that pave the way towards extending the EoS to higher orders in perturbation
theory.


title:
Google's Multilingual Neural Machine Translation System: Enabling
  Zero-Shot Translation

abstract:
  We propose a simple solution to use a single Neural Machine Translation (NMT)
model to translate between multiple languages. Our solution requires no change
in the model architecture from our base system but instead introduces an
artificial token at the beginning of the input sentence to specify the required
target language. The rest of the model, which includes encoder, decoder and
attention, remains unchanged and is shared across all languages. Using a shared
wordpiece vocabulary, our approach enables Multilingual NMT using a single
model without any increase in parameters, which is significantly simpler than
previous proposals for Multilingual NMT. Our method often improves the
translation quality of all involved language pairs, even while keeping the
total number of model parameters constant. On the WMT'14 benchmarks, a single
multilingual model achieves comparable performance for
English$\rightarrow$French and surpasses state-of-the-art results for
English$\rightarrow$German. Similarly, a single multilingual model surpasses
state-of-the-art results for French$\rightarrow$English and
German$\rightarrow$English on WMT'14 and WMT'15 benchmarks respectively. On
production corpora, multilingual models of up to twelve language pairs allow
for better translation of many individual pairs. In addition to improving the
translation quality of language pairs that the model was trained with, our
models can also learn to perform implicit bridging between language pairs never
seen explicitly during training, showing that transfer learning and zero-shot
translation is possible for neural translation. Finally, we show analyses that
hints at a universal interlingua representation in our models and show some
interesting examples when mixing languages.


title: Cantor spectra of magnetic chain graphs

abstract:
  We demonstrate a one-dimensional magnetic system can exhibit a Cantor-type
spectrum using an example of a chain graph with $\delta$ coupling at the
vertices exposed to a magnetic field perpendicular to the graph plane and
varying along the chain. If the field grows linearly with an irrational slope,
measured in terms of the flux through the loops of the chain, we demonstrate
the character of the spectrum relating it to the almost Mathieu operator.


title:
Local environment effects on a charge carrier injected into an Ising
  chain

abstract:
  We present numerically exact results for the spectral function of a single
charge carrier that is injected into an Ising chain at finite temperature $T$.
Both ferromagnetic and antiferromagnetic coupling between the Ising spins are
considered. The interaction between the carrier and the Ising spins is assumed
to be on-site and of Ising type, as well. We find that the carrier's spectral
function exhibits a distinctive fine structure of resonances that are due to
the temporary entrapping of the carrier inside small magnetic domains. The
connection to models of disordered binary alloys where similar effects can
occur is explained. We use these results to construct an accurate
(quasi)analytic approximation for low and medium-$T$ spectral functions.


title:
Splitting matters: how monotone transformation of predictor variables
  may improve the predictions of decision tree models

abstract:
  It is widely believed that the prediction accuracy of decision tree models is
invariant under any strictly monotone transformation of the individual
predictor variables. However, this statement may be false when predicting new
observations with values that were not seen in the training-set and are close
to the location of the split point of a tree rule. The sensitivity of the
prediction error to the split point interpolation is high when the split point
of the tree is estimated based on very few observations, reaching 9%
misclassification error when only 10 observations are used for constructing a
split, and shrinking to 1% when relying on 100 observations. This study
compares the performance of alternative methods for split point interpolation
and concludes that the best choice is taking the mid-point between the two
closest points to the split point of the tree. Furthermore, if the (continuous)
distribution of the predictor variable is known, then using its probability
integral for transforming the variable ("quantile transformation") will reduce
the model's interpolation error by up to about a half on average. Accordingly,
this study provides guidelines for both developers and users of decision tree
models (including bagging and random forest).


title:
Note on Nonlinear Schr\"odinger Equation, KdV Equation and 2D
  Topological Yang-Mills-Higgs Theory

abstract:
  In this paper we discuss the relation between the (1+1)D nonlinear
Schr\"odinger equation and the KdV equation. By applying the boson/vortex
duality, we can map the classical nonlinear Schr\"odinger equation into the
classical KdV equation in the small coupling limit, which corresponds to the UV
regime of the theory. At quantum level, the two theories satisfy the Bethe
Ansatz equations of the spin-$\frac{1}{2}$ XXX chain and the XXZ chain in the
continuum limit respectively. Combining these relations with the dualities
discussed previously in the literature, we propose a duality web in the UV
regime among the nonlinear Schr\"odinger equation, the KdV equation and the 2D
$\mathcal{N}=(2,2)^*$ topological Yang-Mills-Higgs theory.

categories: hep-th cond-mat.quant-gas math-ph math.MP


title: Coincidences of homological densities, predicted by arithmetic

abstract:
  Motivated by analogies with basic density theorems in analytic number theory,
we introduce a notion (and variations) of the homological density of one space
in another. We use Weil's number field/ function field analogy to predict
coincidences for limiting homological densities of various sequences
$\mathcal{Z}^{(d_1,\ldots,d_m)}_n(X)$ of spaces of $0$-cycles on manifolds $X$.
The main theorem in this paper is that these topological predictions, which
seem strange from a purely topological viewpoint, are indeed true.
  The obstacle to proving such a theorem with current technology is how to deal
with the combinatorial complexity of all possible "collisions" of points, this
problem does not arise in the simplest (and classical) case $(m,n)=(1,2)$ of
configuration spaces. To overcome this obstacle we develop a method that uses
the Bj\"orner--Wachs theory of lexicographic shellability from algebraic
combinatorics to study such problems. As a consequence we derive new
homological stability theorems for broad classes of $0$-cycles on manifolds.
Even in the classical case $(m,n)=(1,2)$ this gives a new, simplified proof of
classical results, and also of recent theorems of Church and others.


title: 2D Implosion Simulations with a Kinetic Particle Code

abstract:
  We perform two-dimensional (2D) implosion simulations using a Monte Carlo
kinetic particle code. The paper is motivated by the importance of
non-equilibrium effects in inertial confinement fusion (ICF) capsule
implosions. These cannot be fully captured by hydrodynamic simulations while
kinetic methods, as the one presented in this study, are able to describe
continuum and rarefied regimes within one approach. In the past, our code has
been verified via traditional shock wave and fluid instability simulations. In
the present work, we focus on setups that are closer to applications in ICF. We
perform simple 2D disk implosion simulations using one particle species. The
obtained results are compared to simulations using the hydrodynamics code RAGE.
In a first study, the implosions are powered by energy deposition in the outer
layers of the disk. We test the impact of the particle mean-free-path and find
that while the width of the implosion shock broadens, its location as a
function of time remains very similar. In a second study, we focus on the
formation of fluid instabilities from induced perturbations. We find good
agreement with hydrodynamic studies regarding the location of the shock, the
implosion dynamics and the formation of imposed fluid instabilities.
Differences are due to the higher resolution of RAGE and statistical noise in
the kinetic simulations. The current studies represent proofs-of-principle and
serve as a stepping stone for more sophisticated ICF simulations in the future.


title:
Entangled state teleportation through a couple of quantum channels
  composed of XXZ dimers in an Ising-XXZ diamond chain

abstract:
  The quantum teleportation plays an important role in quantum information
process, in this sense, the quantum entanglement properties involving an
infinite chain structure is quite remarkable because real materials could be
well represented by an infinite chain. We study the teleportation of an
entangled state through a couple of quantum channels, composed by Heisenberg
dimers in an infinite Ising-Heisenberg diamond chain, the couple of chains are
considered sufciently far away from each other to be ignored the any
interaction between them . To teleporting a couple of qubits through the
quantum channel, we need to find the average density operator for Heisenberg
spin dimers, which will be used as quantum channels. Assuming the input state
as a pure state, we can apply the concept of fidelity as a useful measurement
of teleportation performance of a quantum channel. Using the standard
teleportation protocol, we have derived an analytical expression for the output
concurrence, fidelity, and average fidelity. We study in detail the effects of
coupling parameters, external magnetic field and temperature dependence of
quantum teleportation. Finally, we explore the relations between entanglement
of the quantum channel, the output entanglement and the average fidelity of the
system. Through a kind of phase diagram as a function of Ising-Heisenberg
diamond chain model parameters, we illustrate where the quantum teleportation
will succeed and a region where the quantum teleportation could fail.


title:
One Leptoquark to unify them? Neutrino masses and unification in the
  light of $(g-2)_\mu$, $R_{D^{(\star)}}$ and $R_K$ anomalies

abstract:
  Leptoquarks have been proposed as a possible explanation of anomalies in
$\bar{B}\mapsto D^{*} \tau \bar{\nu } $ decays, the apparent anomalies in
$(g-2)_\mu$ experiments and a violation of lepton universality. Motivated by
this, we examine other motivations of leptoquarks: radiatively induced neutrino
masses in the presence of a discrete symmetry that prevents a tree level
see-saw mechanism, gauge coupling unification, and vacuum stability at least up
to the unification scale. We present a new model for radiatively generating a
neutrino mass which can significantly improve gauge coupling unification at one
loop. We discuss this, and other models in the light of recent work on flavour
anomalies.


title: Capacity of the range of random walk on $\mathbb{Z}^4$

abstract:
  We study the scaling limit of the capacity of the range of a simple random
walk on the integer lattice in dimension four. We establish a strong law of
large numbers and a central limit theorem with a non-gaussian limit. The
asymptotic behaviour is analogous to that found by Le Gall in '86 for the
volume of the range in dimension two.


title: Heavy quarkonium moving in hot and dense deconfined nuclear matter

abstract:
  We study the behavior of the complex potential between a heavy quark and its
antiquark, which are in relative motion with respect to a hot and dense medium.
The heavy quark-antiquark complex potential is obtained by correcting both the
Coulombic and the linear terms in the Cornell potential through a dielectric
function estimated within the real-time formalism using the hard thermal loop
approximation. We show the variation of both the real and the imaginary parts
of the potential for different values of velocities when the bound state ($
Q\bar{Q}$ pair) is aligned in the direction parallel as well as perpendicular
to the relative velocity of the $ Q\bar{Q}$ pair with the thermal medium. With
an increase of the relative velocity the screening of the real part of the
potential becomes weaker at short distances and stronger at large distances for
the parallel case. However, for the perpendicular case the potential decreases
with an increase of the velocity at all distances which results in the larger
screening of the potential. In addition, the inclusion of the string term makes
the screening of the potential weaker as compared to the Coulombic term alone
for both cases. Therefore, by combining all these effects we expect a stronger
binding of a $ Q\bar{Q} $ pair in a moving medium in the presence of the string
term as compared to the Coulombic term alone. The imaginary part decreases (in
magnitude) with an increase of the relative velocity, leading to a decrease of
the width of the quarkonium state at higher velocities. The inclusion of the
string term increases the magnitude of the imaginary part, which results in an
increase of the width of the quarkonium states. All of these effects lead to
the modification in the dissolution of quarkonium states.


title: Szekeres models: a covariant approach

abstract:
  We exploit the 1+1+2 formalism to covariantly describe the inhomogeneous and
anisotropic Szekeres models. It is shown that an \emph{average scale length}
can be defined \emph{covariantly} which satisfies a 2d equation of motion
driven from the \emph{effective gravitational mass} (EGM) contained in the dust
cloud. The contributions to the EGM are encoded to the energy density of the
dust fluid and the free gravitational field $E_{ab}$. We show that the
quasi-symmetric property of the Szekeres models is justified through the
existence of 3 independent \emph{Intrinsic Killing Vector Fields (IKVFs)}. In
addition the notions of the Apparent and Absolute Apparent Horizons are briefly
discussed and we give an alternative gauge-invariant form to define them in
terms of the kinematical variables of the spacelike congruences. We argue that
the proposed program can be used in order to express Sachs' optical equations
in a covariant form and analyze the confrontation of a spatially inhomogeneous
irrotational overdense fluid model with the observational data.


title: O($N$) Invariance of the Multi-Field Bounce

abstract:
  In his 1977 paper on vacuum decay in field theory: The Fate of the False
Vacuum, Coleman considered the problem of a single scalar field and assumed
that the minimum action tunnelling field configuration, the bounce, is
invariant under O(4) rotations in Euclidean space. A proof of the O(4)
invariance of the bounce was provided later by Coleman, Glaser, and Martin
(CGM), who extended the proof to $N>2$ Euclidean dimensions but, again,
restricted non-trivially to a single scalar field. As far as we know a proof of
O($N$) invariance of the bounce for the tunnelling problem with multiple scalar
fields has not been reported, even though it was assumed in many works since,
being of phenomenological interest. We make progress towards closing this gap.
Following CGM we define the reduced problem of finding a field configuration
minimizing the kinetic energy at fixed potential energy. Given a solution of
the reduced problem, the minimum action bounce can always be obtained from it
by means of a scale transformation. We show that if a solution of the reduced
problem exists, then it and the minimum action bounce derived from it are
indeed O($N$) symmetric.


title: Three-family left-right symmetry with low-scale seesaw mechanism

abstract:
  We suggest a new left-right symmetric model implementing a low-scale seesaw
mechanism in which quantum consistency requires three families of fermions. The
symmetry breaking route to the Standard Model determines the profile of the
"next" expected new physics, characterized either by the simplest left-right
gauge symmetry or by the 3-3-1 scenario. The resulting $Z^\prime$ gauge bosons
can be probed at the LHC and provide a production portal for the right-handed
neutrinos. On the other hand, its flavor changing interactions would affect the
K, D and B neutral meson systems.


title: Seesaw Scale and CP Phases in a Minimal Model of Leptogenesis

abstract:
  The seesaw mechanism to derive the light masses of left-handed neutrinos
using heavy masses of right-handed neutrinos gives rise to a connection between
low-energy measurables and GUT-scale mechanism. We expresses the neutrino
mixing angles in terms of a single variable $\sin\theta_{13}$, whose size was
measured recently. The lepton asymmetry from heavy neutrinos via Yukawa
coupling is described by CP phases in both Dirac and Majorana type. It is shown
that the seesaw scale relevant to the lepton asymmetry can be constrained by CP
phase in this minimal model.


title:
A Review of Mathematical Modeling, Simulation and Analysis of Membrane
  Channel Charge Transport

abstract:
  The molecular mechanism of ion channel gating and substrate modulation is
elusive for many voltage gated ion channels, such as eukaryotic sodium ones.
The understanding of channel functions is a pressing issue in molecular
biophysics and biology. Mathematical modeling, computation and analysis of
membrane channel charge transport have become an emergent field and give rise
to significant contributions to our understanding of ion channel gating and
function. This review summarizes recent progresses and outlines remaining
challenges in mathematical modeling, simulation and analysis of ion channel
charge transport. One of our focuses is the Poisson-Nernst-Planck (PNP) model
and its generalizations. Specifically, the basic framework of the PNP system
and some of its extensions, including size effects, ion-water interactions,
coupling with density functional theory and relation to fluid flow models. A
reduced theory, the Poisson- Boltzmann-Nernst-Planck (PBNP) model, and a
differential geometry based ion transport model are also discussed. For proton
channel, a multiscale and multiphysics Poisson-Boltzmann-Kohn-Sham (PBKS) model
is presented. We show that all of these ion channel models can be cast into a
unified variational multiscale framework with a macroscopic continuum domain of
the solvent and a microscopic discrete domain of the solute. The main strategy
is to construct a total energy functional of a charge transport system to
encompass the polar and nonpolar free energies of solvation and chemical
potential related energies. Current computational algorithms and tools for
numerical simulations and results from mathematical analysis of ion channel
systems are also surveyed.


title: A dynamics-free lower bound on the mass of our galaxy

abstract:
  We use a sample of Milky Way (MW) analogs for which we have stellar and disk
gas mass measurements, published measurements of halo gas masses of the MW and
of similar galaxies, and the well-established value of the cosmological baryon
fraction to place a lower bound on the mass of the Galaxy of $7.7\times10^{11}
M_\odot$ and estimate that the mass is likely to be $\ge 1.2\times10^{12}$
M$_\odot$. Although most dynamical analyses yield measurements consistent with
these results, several recent studies have advocated for a total mass well
below $10^{12} M_\odot$. We reject such low mass estimates because they imply a
Galactic baryon matter fraction significantly above the universal value.
Convergence between dynamical mass estimates and those based on the baryonic
mass is an important milestone in our understanding of galaxies.


title:
Low-temperature evolution of the spectral weight of a spin-up carrier
  moving in a ferromagnetic background

abstract:
  We derive the lowest-temperature correction to the self-energy of a spin-up
particle injected in a ferromagnetic background. The background is modeled with
both Heisenberg and Ising Hamiltonians so that differences due to gapless vs.
gapped magnons can be understood. Beside the expected thermal broadening of the
quasiparticle peak as it becomes a resonance inside a continuum, we also find
that spectral weight is transferred to regions lying outside this continuum. We
explain the origin of this spectral weight transfer and its low-temperature
evolution.


title:
Strong law of large numbers for the capacity of the Wiener sausage in
  dimension four

abstract:
  We prove a strong law of large numbers for the Newtonian capacity of a Wiener
sausage in the critical dimension four.


title: Character expansion of matrix integrals

abstract:
  We consider character expansion of tau functions and multiple integrals in
characters of orhtogonal and symplectic groups. In particular we consider
character expansions of integrals over orthogonal and over symplectic matrices.


title:
Earliness-Aware Deep Convolutional Networks for Early Time Series
  Classification

abstract:
  We present Earliness-Aware Deep Convolutional Networks (EA-ConvNets), an
end-to-end deep learning framework, for early classification of time series
data. Unlike most existing methods for early classification of time series
data, that are designed to solve this problem under the assumption of the
availability of a good set of pre-defined (often hand-crafted) features, our
framework can jointly perform feature learning (by learning a deep hierarchy of
\emph{shapelets} capturing the salient characteristics in each time series),
along with a dynamic truncation model to help our deep feature learning
architecture focus on the early parts of each time series. Consequently, our
framework is able to make highly reliable early predictions, outperforming
various state-of-the-art methods for early time series classification, while
also being competitive when compared to the state-of-the-art time series
classification algorithms that work with \emph{fully observed} time series
data. To the best of our knowledge, the proposed framework is the first to
perform data-driven (deep) feature learning in the context of early
classification of time series data. We perform a comprehensive set of
experiments, on several benchmark data sets, which demonstrate that our method
yields significantly better predictions than various state-of-the-art methods
designed for early time series classification. In addition to obtaining high
accuracies, our experiments also show that the learned deep shapelets based
features are also highly interpretable and can help gain better understanding
of the underlying characteristics of time series data.


title:
Quasars Probing Galaxies: I. Signatures of Gas Accretion at Redshift
  Approximately 0.2

abstract:
  We describe the kinematics of circumgalactic gas near the galactic plane,
combining new measurements of galaxy rotation curves and spectroscopy of
background quasars. The sightlines pass within 19--93 kpc of the target galaxy
and generally detect Mg II absorption. The Mg II Doppler shifts have the same
sign as the galactic rotation, so the cold gas co-rotates with the galaxy.
Because the absorption spans a broader velocity range than disk rotation can
explain, we explore simple models for the circumgalactic kinematics. Gas
spiraling inwards (near the disk plane) offers a successful description of the
observations. An Appendix describes the addition of tangential and radial gas
flows and illustrates how the sign of the disk inclination produces testable
differences in the projected line-of-sight velocity range. This inflow
interpretation implies that cold flow disks remain common down to redshift $z
\approx 0.2$ and prolong star formation by supplying gas to the disk.


title: Some conjectures on codes

abstract:
  Variable-length codes are the bases of the free submonoids of a free monoid.
There are some important longstanding open questions about the structure of
finite maximal codes. In this paper we discuss this conjectures and their
relations with factorizations of cyclic groups.