title: Simulation from quasi-stationary distributions on reducible state spaces

abstract:
  Quasi-stationary distributions (QSDs)arise from stochastic processes that
exhibit transient equilibrium behaviour on the way to absorption QSDs are often
mathematically intractable and even drawing samples from them is not
straightforward. In this paper the framework of Sequential Monte Carlo samplers
is utilized to simulate QSDs and several novel resampling techniques are
proposed to accommodate models with reducible state spaces, with particular
focus on preserving particle diversity on discrete spaces. Finally an approach
is considered to estimate eigenvalues associated with QSDs, such as the decay
parameter.


title: Origin of Small-Scale Anisotropies in Galactic Cosmic Rays

abstract:
  The arrival directions of Galactic cosmic rays (CRs) are highly isotropic.
This is expected from the presence of turbulent magnetic fields in our Galactic
environment that repeatedly scatter charged CRs during propagation. However,
various CR observatories have identified weak anisotropies of various angular
sizes and with relative intensities of up to a level of 1 part in 1,000.
Whereas large-scale anisotropies are generally predicted by standard diffusion
models, the appearance of small-scale anisotropies down to an angular size of
10 degrees is surprising. In this review, we summarise the current experimental
situation for both the large-scale and small-scale anisotropies. We address
some of the issues in comparing different experimental results and remaining
questions in interpreting the observed large-scale anisotropies. We then review
the standard diffusive picture and its difficulty in producing the small-scale
anisotropies. Having set the stage, we review the various ideas and models put
forward for explaining the small-scale anisotropies.


title: Quantum Aspects of Black Objects in String Theory

abstract:
  One of important directions in superstring theory is to reveal the quantum
nature of black hole. In this paper we embed Schwarzschild black hole into
superstring theory or M-theory, which we call a smeared black hole, and resolve
quantum corrections to it. Furthermore we boost the smeared black hole along
the 11th direction and construct a smeared quantum black 0-brane in 10
dimensions. Quantum aspects of the thermodynamic for these black objects are
investigated in detail. We also discuss radiations of a string and a D0-brane
from the smeared quantum black 0-brane.


title: On the nature of some SGRs and AXPs as rotation-powered neutron stars

abstract:
  We investigate the possibility that some SGRs/AXPs could be canonical
rotation-powered pulsars using realistic NS structure parameters instead of
fiducial values. We show that realistic NS parameters lowers the estimated
value of the magnetic field and radiation efficiency, $L_X/\dot{E}_{\rm rot}$,
with respect to estimates based on fiducial NS parameters. We show that nine
SGRs/AXPs can be described as canonical pulsars driven by the NS rotational
energy, for $L_X$ computed in the soft (2--10~keV) X-ray band. We compute the
range of NS masses for which $L_X/\dot{E}_{\rm rot}<1$. We discuss the observed
hard X-ray emission in three sources of the group of nine potentially
rotation-powered NSs. This additional hard X-ray component dominates over the
soft one leading to $L_X/\dot{E}_{\rm rot}>1$ in two of them. We show that 9
SGRs/AXPs can be rotation-powered NSs if we analyze their X-ray luminosity in
the soft 2--10~keV band. Interestingly, four of them show radio emission and
six have been associated with supernova remnants (including Swift J1834.9-0846
the first SGR observed with a surrounding wind nebula). These observations give
additional support to our results of a natural explanation of these sources in
terms of ordinary pulsars. Including the hard X-ray emission observed in three
sources of the group of potential rotation-powered NSs, this number of sources
with $L_X/\dot{E}_{\rm rot}<1$ becomes seven. It remains open to verification
1) the accuracy of the estimated distances and 2) the possible contribution of
the associated supernova remnants to the hard X-ray emission.


title:
Extracting an accurate model for permittivity from experimental data :
  Hunting complex poles from the real line

abstract:
  In this letter, we describe a very general procedure to obtain a causal fit
of the permittivity of materials from experimental data with very few
parameters. Unlike other closed forms proposed in the literature, the
particularity of this approach lies in its independence towards the material or
frequency range at stake. Many illustrative numerical examples are given and
the accuracy of the fitting is compared to other expressions in the literature.


title: Stable solutions in potential mean field game systems

abstract:
  We introduce the notion of stable solution in mean field game theory: they
are locally isolated solutions of the mean field game system. We prove that
such solutions exist in potential mean field games and are local attractors for
learning procedures.


title: Fluxes, bundle gerbes and 2-Hilbert spaces

abstract:
  We elaborate on the construction of a prequantum 2-Hilbert space from a
bundle gerbe over a 2-plectic manifold, providing the first steps in a program
of higher geometric quantisation of closed strings in flux compactifications
and of M5-branes in C-fields. We review in detail the construction of the
2-category of bundle gerbes, and introduce the higher geometrical structures
necessary to turn their categories of sections into 2-Hilbert spaces. We work
out several explicit examples of 2-Hilbert spaces in the context of closed
strings and M5-branes on flat space. We also work out the prequantum 2-Hilbert
space associated to an M-theory lift of closed strings described by an
asymmetric cyclic orbifold of the SU(2) WZW model, providing an example of
sections of a torsion gerbe on a curved background. We describe the dimensional
reduction of M-theory to string theory in these settings as a map from
2-isomorphism classes of sections of bundle gerbes to sections of corresponding
line bundles, which is compatible with the respective monoidal structures and
module actions.


title: Integrable Abelian Vortex-like solitons

abstract:
  We propose a modified version of the Ginzburg-Landau energy functional
admitting static solitons and determine all the Painlev\'e-integrable cases of
its Bogomolny equations of a given class of models. Explicit solutions are
determined in terms of the third Painlev\'e transcendents, allowing us to
calculate physical quantities such as the vortex number and the vortex
strength. These solutions can be interpreted as the usual Abelian-Higgs
vortices on surfaces of non-constant curvature with conical singularity.


title:
Interactions and design rules for assembly of porous colloidal
  mesophases

abstract:
  Porous mesophases, where well-defined particle-depleted 'void' spaces are
present within a particle-rich background fluid, can be self-assembled from
colloidal particles interacting via isotropic pair interactions with competing
attractions and repulsions. While such structures could be of wide interest for
technological applications (e.g., filtration, catalysis, absorption, etc.),
relatively few studies have investigated the interactions that lead to these
morphologies and how they compare to those that produce other
micro-phase-separated structures, such as clusters. In this work, we use
inverse methods of statistical mechanics to design model isotropic pair
potentials that form porous mesophases. We characterize the resulting porous
structures, correlating features of the pair potential with the targeted pore
size and the particle packing fraction. The former is primarily encoded by the
amplitude and range of the repulsive barrier of the designed pair potential and
the latter by the attractive well depth. We observe a trade-off with respect to
the packing fraction of the targeted morphology: greater values support more
spherical and monodisperse pores that themselves organize into periodic
structures, while lower values yield more mobile pores that do not assemble
into ordered structures but remain stable over a larger range of packing
fraction. We conclude by commenting on the limitations of targeting a specific
pore diameter within the present inverse design approach as well as by
describing future directions to overcome these limitations.


title: Rational map $ax+1/x$ on the projective line over $\mathbb{Q}\_{p}$

abstract:
  The dynamical structure of the rational map $ax+1/x$ on the projective line
$\P$ over the field $\mathbb{Q}\_p$ of $p$-adic numbers is described for $p\geq
3$.


title:
Fiducial, confidence and objective Bayesian posterior distributions for
  a multidimensional parameter

abstract:
  We propose a way to construct fiducial distributions for a multidimensional
parameter using a step-by-step conditional procedure related to the inferential
importance of the components of the parameter. For discrete models, in which
the non-uniqueness of the fiducial distribution is well known, we propose to
use the geometric mean of the "extreme cases" and show its good behavior with
respect to the more traditional arithmetic mean. Connections with the
generalized fiducial inference approach developed by Hannig and with confidence
distributions are also analyzed. The suggested procedure strongly simplifies
when the statistical model belongs to a subclass of the natural exponential
family, called conditionally reducible, which includes the multinomial and the
negative-multinomial models. Furthermore, because fiducial inference and
objective Bayesian analysis are both attempts to derive distributions for an
unknown parameter without any prior information, it is natural to discuss their
relationships. In particular, the reference posteriors, which also depend on
the importance ordering of the parameters are the natural terms of comparison.
We show that fiducial and reference posterior distributions coincide in the
location-scale models, and we characterize the conditionally reducible natural
exponential families for which this happens. The discussion of some classical
examples closes the paper.


title:
Direct magneto-optical compression of an effusive atomic beam for
  high-resolution focused ion beam application

abstract:
  An atomic rubidium beam formed in a 70 mm long two-dimensional
magneto-optical trap (2D MOT), directly loaded from a collimated Knudsen
source, is analyzed using laser-induced fluorescence. The longitudinal velocity
distribution, the transverse temperature and the flux of the atomic beam are
reported. The equivalent transverse reduced brightness of an ion beam with
similar properties as the atomic beam is calculated because the beam is
developed to be photoionized and applied in a focused ion beam. In a single
two-dimensional magneto-optical trapping step an equivalent transverse reduced
brightness of $(1.0\substack{+0.8-0.4})$ $\times 10^6$ A/(m$^2$ sr eV) was
achieved with a beam flux equivalent to $(0.6\substack{+0.3-0.2})$ nA. The
temperature of the beam is further reduced with an optical molasses after the
2D MOT. This increased the equivalent brightness to $(6\substack{+5-2})$$\times
10^6$ A/(m$^2$ sr eV). For currents below 10 pA, for which disorder-induced
heating can be suppressed, this number is also a good estimate of the ion beam
brightness that can be expected. Such an ion beam brightness would be a six
times improvement over the liquid metal ion source and could improve the
resolution in focused ion beam nanofabrication.


title:
Microseismic events enhancement and detection in sensor arrays using
  autocorrelation based filtering

abstract:
  Passive microseismic data are commonly buried in noise, which presents a
significant challenge for signal detection and recovery. For recordings from a
surface sensor array where each trace contains a time-delayed arrival from the
event, we propose an autocorrelation-based stacking method that designs a
denoising filter from all the traces, as well as a multi-channel detection
scheme. This approach circumvents the issue of time aligning the traces prior
to stacking because every trace's autocorrelation is centered at zero in the
lag domain. The effect of white noise is concentrated near zero lag, so the
filter design requires a predictable adjustment of the zero-lag value.
Truncation of the autocorrelation is employed to smooth the impulse response of
the denoising filter. In order to extend the applicability of the algorithm, we
also propose a noise prewhitening scheme that addresses cases with colored
noise. The simplicity and robustness of this method are validated with
synthetic and real seismic traces.


title: Quantum Dynamics of Skyrmions in Chiral Magnets

abstract:
  We study the quantum propagation of a Skyrmion in chiral magnetic insulators
by generalizing the micromagnetic equations of motion to a finite-temperature
path integral formalism, using field theoretic tools. Promoting the center of
the Skyrmion to a dynamic quantity, the fluctuations around the Skyrmionic
configuration give rise to a time-dependent damping of the Skyrmion motion.
From the frequency dependence of the damping kernel, we are able to identify
the Skyrmion mass, thus providing a microscopic description of the kinematic
properties of Skyrmions. When defects are present or a magnetic trap is
applied, the Skyrmion mass acquires a finite value proportional to the
effective spin, even at vanishingly small temperature. We demonstrate that a
Skyrmion in a confined geometry provided by a magnetic trap behaves as a
massive particle owing to its quasi-one-dimensional confinement. An additional
quantum mass term is predicted, independent of the effective spin, with an
explicit temperature dependence which remains finite even at zero temperature.


title:
On renormalised solution for thermomechanical problem in perfect -
  plasticity

abstract:
  We consider the quasi-static evolution of the thermo-plasticity model in
which the evolution equation law for the inelastic strain is given by the
Prandtl-Reuss flow rule. The thermal part of the Cauchy stress tensor is not
linearised in the neighbourhood of a references temperature. This nonlinear
thermal part imposed to add a damping term to the balance of the momentum,
which can be interpreted as external forces acting on the material. In general
the dissipation term occurring in the heat equation is integrable function only
and the standard methods can not be applied. Combining truncation techniques
and Boccardo-Gallou\"et approach with monotone methods we prove an existence of
renormalised solutions.


title:
Knowing When to Look: Adaptive Attention via A Visual Sentinel for Image
  Captioning

abstract:
  Attention-based neural encoder-decoder frameworks have been widely adopted
for image captioning. Most methods force visual attention to be active for
every generated word. However, the decoder likely requires little to no visual
information from the image to predict non-visual words such as "the" and "of".
Other words that may seem visual can often be predicted reliably just from the
language model e.g., "sign" after "behind a red stop" or "phone" following
"talking on a cell". In this paper, we propose a novel adaptive attention model
with a visual sentinel. At each time step, our model decides whether to attend
to the image (and if so, to which regions) or to the visual sentinel. The model
decides whether to attend to the image and where, in order to extract
meaningful information for sequential word generation. We test our method on
the COCO image captioning 2015 challenge dataset and Flickr30K. Our approach
sets the new state-of-the-art by a significant margin.


title:
Relative generalized matrix weights of matrix codes for universal
  security on wire-tap networks

abstract:
  Universal security over a network with linear network coding has been
intensively studied. However, previous linear codes and code pairs used for
this purpose were linear over a larger field than that used on the network,
which restricts the possible packet lengths of optimal universal secure codes,
does not allow to apply known list-decodable rank-metric codes and requires
performing operations over a large field. In this work, we introduce new
parameters (relative generalized matrix weights and relative dimension/rank
support profile) for code pairs that are linear over the field used in the
network, and show that they measure the universal security performance of these
code pairs. For one code and non-square matrices, generalized matrix weights
coincide with the existing Delsarte generalized weights, hence we prove the
connection between these latter weights and secure network coding, which was
left open. As main applications, the proposed new parameters enable us to: 1)
Obtain optimal universal secure linear codes on noiseless networks for all
possible packet lengths, in particular for packet lengths not considered
before, 2) Obtain the first universal secure list-decodable rank-metric code
pairs with polynomial-sized lists, based on a recent construction by Guruswami
et al, and 3) Obtain new characterizations of security equivalences of linear
codes. Finally, we show that our parameters extend relative generalized Hamming
weights and relative dimension/length profile, respectively, and relative
generalized rank weights and relative dimension/intersection profile,
respectively.


title:
Poincar\'e duality for tropical Dolbeault cohomology of non-archimedean
  Mumford curves

abstract:
  We calculate the tropical Dolbeault cohomology for the analytifications of
the projective line and Mumford curves over non-archimedean fields. We show
that the cohomology satisfies Poincar\'e duality and behaves analogously to the
cohomology of curves over the complex numbers. Further, we give a complete
calculation of the dimension of the cohomology on a basis of the topology.


title: Abstract tropical linear programming

abstract:
  In this paper we develop a combinatorial abstraction of tropical linear
programming. This generalizes the search for a feasible point of a system of
min-plus-inequalities. It is based on the polyhedral properties of
triangulations of the product of two simplices and the combinatorics of the
associated set of bipartite graphs with an additional sign information which we
call a signed tropical matroid. We demonstrate the connections with the
classical simplex method, mean payoff games and scheduling.


title:
Controlled growth of CH$_3$NH$_3$PbI$_3$ nanowires in arrays of open
  nanofluidic channels

abstract:
  Spatial positioning of nanocrystal building blocks on a solid surface is a
prerequisite for assembling individual nanoparticles into functional devices.
Here, we report on the graphoepitaxial liquid-solid growth of nanowires of the
photovoltaic compound CH$_3$NH$_3$PbI$_3$ in open nanofluidic channels. The
guided growth, visualized in real-time with a simple optical microscope,
undergoes through a metastable solvatomorph formation in polar aprotic
solvents. The presently discovered crystallization leads to the fabrication of
mm2-sized surfaces composed of perovskite nanowires having controlled sizes,
cross-sectional shapes, aspect ratios and orientation which have not been
achieved thus far by other deposition methods. The automation of this general
strategy paves the way towards fabrication of wafer-scale perovskite nanowire
thin films well-suited for various optoelectronic devices, e.g. solar cells,
lasers, light-emitting diodes and photodetectors.


title: Cross-Lingual Predicate Mapping Between Linked Data Ontologies

abstract:
  Ontologies in different natural languages often differ in quality in terms of
richness of schema or richness of internal links. This difference is markedly
visible when comparing a rich English language ontology with a non-English
language counterpart. Discovering alignment between them is a useful endeavor
as it serves as a starting point in bridging the disparity. In particular, our
work is motivated by the absence of inter-language links for predicates in the
localised versions of DBpedia. In this paper, we propose and demonstrate an
ad-hoc system to find possible owl:equivalentProperty links between predicates
in ontologies of different natural languages. We seek to achieve this mapping
by using pre-existing inter-language links of the resources connected by the
given predicate. Thus, our methodology stresses on semantic similarity rather
than lexical. Moreover, through an evaluation, we show that our system is
capable of outperforming a baseline system that is similar to the one used in
recent OAEI campaigns.


title:
Monotonicity of the Sample Range of 3-D Data: Moments of Volumes of
  Random Tetrahedra

abstract:
  The sample range of uniform random points $X_1, \dots , X_n$ chosen in a
given convex set is the convex hull ${\rm conv}[X_1, \dots, X_n]$. It is shown
that in dimension three the expected volume of the sample range is not monotone
with respect to set inclusion. This answers a question by Meckes in the
negative.
  The given counterexample is the three-dimensional tetrahedron together with
an infinitesimal variation of it. As side result we obtain an explicit formula
for all even moments of the volume of a random simplex which is the convex hull
of three uniform random points in the tetrahedron and the center of one facet.


title:
Analysis and Evaluation of Real-time and Safety Characteristics of IEEE
  802.11p protocol in VANET

abstract:
  The need for safety in transportation systems has increased the popularity
and applicability of Vehicular Ad-Hoc Networks (VANETs) in recent years.
On-time reception and processing of alarms caused by possible accidents as well
as the preventive actions have important roles in reducing human and financial
losses in road accidents. In such cases, the performance of safety applications
should be evaluated and guaranteed to show whether or not they can ensure the
safety of humans and cars. In this paper, we analyze the behavior of Vehicular
Ad-Hoc Networks by checking the real-time properties of the IEEE 802.11p
protocol using a Colored Petri Net model. To analyze the performance of related
standards, simulations are conducted using CPNTools. Standards from European
Telecommunications Standards Institute (ETSI), and Vehicle Safety
Communications (VSC) are evaluated in this research. We will show that such
standards may not completely fulfill the safety requirements in particular
situations.


title:
Multimodal Transfer: A Hierarchical Deep Convolutional Neural Network
  for Fast Artistic Style Transfer

abstract:
  Transferring artistic styles onto everyday photographs has become an
extremely popular task in both academia and industry. Recently, offline
training has replaced on-line iterative optimization, enabling nearly real-time
stylization. When those stylization networks are applied directly to
high-resolution images, however, the style of localized regions often appears
less similar to the desired artistic style. This is because the transfer
process fails to capture small, intricate textures and maintain correct texture
scales of the artworks. Here we propose a multimodal convolutional neural
network that takes into consideration faithful representations of both color
and luminance channels, and performs stylization hierarchically with multiple
losses of increasing scales. Compared to state-of-the-art networks, our network
can also perform style transfer in nearly real-time by conducting much more
sophisticated training offline. By properly handling style and texture cues at
multiple scales using several modalities, we can transfer not just large-scale,
obvious style cues but also subtle, exquisite ones. That is, our scheme can
generate results that are visually pleasing and more similar to multiple
desired artistic styles with color and texture cues at multiple scales.


title:
Bilayer Linearized Tensor Renormalization Group Approach for Thermal
  Tensor Networks

abstract:
  In this paper, we perform a comprehensive study of the renormalization group
(RG) method on thermal tensor networks (TTN). By Trotter-Suzuki decomposition,
one obtains the 1+1D TTN representing the partition function of 1D quantum
lattice models, and then employs efficient RG contractions to obtain the
thermodynamic properties with high precision. The linearized tensor
renormalization group (LTRG) method, which can be used to contract TTN in an
efficient and accurate way, is briefly reviewed. In addition, the single-layer
LTRG can be generalized to a bilayer form, dubbed as LTRG++, in both finite-
and infinite-size systems, with accuracies significantly improved. We provide
the details of LTRG++ in finite-size system, comparing its accuracy with
single-layer algorithm, and elaborate the infinite-size LTRG++ in the context
of fermion chain model. We show that the LTRG++ algorithm in infinite-size
system is in essence equivalent to transfer-matrix renormalization group
method, while expressed in a tensor network language. LTRG++ is then applied to
study an extended Hubbard model, where the phase separation phenomenon,
groundstate phase diagram, as well as quantum criticality-enhanced
magnetocaloric effects under external fields, are investigated.


title: Validating pore-scale models of drying using microfluidic experiments

abstract:
  We present an experimental micro-model of drying porous media, based on
microfluidic cells made of arrays of pillars on a regular grid, and complement
these experiments with a matching two-dimensional pore-network model of drying.
Disorder, or small-scale heterogeneity, was introduced into the cells by
randomly varying the radii of the pillars, around their average value. The
microfluidic chips were filled with a volatile oil and then dried horizontally,
such that gravitational effects were excluded. The experimental and simulated
drying rates and drying patterns were then compared in detail, for various
levels of disorder, in order to verify the predictive capabilities of our
model. The geometrical features were reproduced well, while reproducing drying
rates proved to be more challenging.


title:
Monte Carlo simulations of measured electron energy-loss spectra of
  diamond and graphite: role of dielectric-response models

abstract:
  In this work we compare Monte Carlo (MC) simulations of electron transport
properties with reflection electron energy loss measurements in diamond and
graphite films. We assess the impact of different approximations of the
dielectric response on the observables of interest for the characterization of
carbon-based materials. We calculate the frequency-dependent dielectric
response and energy loss function of these materials in two ways: a full ab
initio approach, in which we carry out time-dependent density functional
simulations in linear response for different momentum transfers, and a
semi-classical model, based on the Drude--Lorentz extension to finite momenta
of the optical dielectric function. Ab initio calculated dielectric functions
lead to a better agreement with electron energy loss measured spectra with
respect the widely used Drude-Lorentz model. This discrepancy is particularly
evident for insulators and semiconductors beyond the optical limit ($\mathbf{q}
\neq 0$), where single particle excitations become relevant. Furthermore, we
show that the behaviour of the energy loss function at different accuracy
levels has a dramatic effect on other physical observables, such as the
inelastic mean free path and the stopping power in the low energy regime ($<
100$ eV) and thus on the accuracy of MC simulations.


title: Algebraic entropy in locally linearly compact vector spaces

abstract:
  We introduce the algebraic entropy for continuous endomorphisms of locally
linearly compact vector spaces over a discrete field, as the natural extension
of the algebraic entropy for endomorphisms of discrete vector spaces. We show
that the main properties of entropy continue to hold in the general context of
locally linearly compact vector spaces, in particular we extend the Addition
Theorem.


title:
Isotopic profiles imply strong convective influence on water near the
  tropical tropopause

abstract:
  The influence of deep convection on water vapor in the Tropical Tropopause
Layer (TTL), the region just below the high ($\sim$18 km), cold tropical
tropopause, remains an outstanding question in atmospheric science. Moisture
transport to this region is important for climate projections because it drives
the formation of local cirrus (ice) clouds, which have a disproportionate
impact on the Earth's radiative balance. Deep cumulus towers carrying large
volumes of ice are known to reach the TTL, but their importance to the water
budget has been debated for several decades. We show here that profiles of the
isotopic composition of water vapor can provide a quantitative estimate of the
convective contribution to TTL moistening. Isotopic measurements from the ACE
satellite instrument, in conjunction with ice loads inferred from CALIOP
satellite measurements and simple mass-balance modeling, suggest that
convection is the dominant source of water vapor in the TTL up to
near-tropopause altitudes. The relatively large ice loads inferred from CALIOP
satellite measurements can be produced only with significant water sources, and
isotopic profiles imply that these sources are predominantly convective ice.
Sublimating ice from deep convection appears to increase TTL cirrus by a factor
of several over that expected if cirrus production were driven only by
large-scale uplift; sensitivity analysis implies that these conclusions are
robust for most physically reasonable assumptions. Changes in tropical deep
convection in future warmer conditions may thus provide an important climate
feedback.


title: Evolving network structure of academic institutions

abstract:
  Today's colleges and universities consist of highly complex structures that
dictate interactions between the administration, faculty, and student body.
These structures can play a role in dictating the efficiency of policy enacted
by the administration and determine the effect that curriculum changes in one
department have on other departments. Despite the fact that the features of
these complex structures have a strong impact on the institutions, they remain
by-and-large unknown in many cases. In this paper we study the academic
structure of our home institution of Trinity College in Hartford, CT using the
major and minor patterns between graduating students to build a temporal
multiplex network describing the interactions between different departments.
Using recent network science techniques developed for such temporal networks we
identify the evolving community structures that organize departments'
interactions, as well as quantify the interdisciplinary centrality of each
department. We implement this framework for Trinity College, finding practical
insights and applications, but also present it as a general framework for
colleges and universities to better understand their own structural makeup in
order to better inform academic and administrative policy.


title:
Asymptotic number of caterpillars of regularly varying
  $\Lambda$-coalescents that come down from infinity

abstract:
  In this paper we look at the asymptotic number of r-caterpillars for
$\Lambda$-coalescents which come down from infinity, under a regularly varying
assumption. An r-caterpillar is a functional of the coalescent process started
from $n$ individuals which, roughly speaking, is a block of the coalescent at
some time, formed by one line of descend to which r-1 singletons have merged
one by one. We show that the number of $r$-caterpillars, suitably scaled,
converge to an explicit constant as the sample size n goes to infinity.


title: Explicit estimates on the measure of primary KAM tori

abstract:
  From KAM Theory it follows that the measure of phase points which do not lie
on Diophantine, Lagrangian, "primary" tori in a nearly--integrable,
real--analytic Hamiltonian system is $O(\sqrt{\varepsilon})$, if $\varepsilon$
is the size of the perturbation. In this paper we discuss how the constant in
front of $\sqrt{\varepsilon}$ depends on the unperturbed system and in
particular on the phase--space domain.


title: Distributed Detection in Ad Hoc Networks Through Quantized Consensus

abstract:
  We study asymptotic performance of distributed detection in large scale
connected sensor networks. Contrasting to the canonical parallel network where
a single node has access to local decisions from all other nodes, each node can
only exchange information with its direct neighbors in the present setting. We
establish that, with each node employing an identical one-bit quantizer for
local information exchange, a novel consensus reaching approach can achieve the
optimal asymptotic performance of centralized detection as the network size
scales. The statement is true under three different detection frameworks: the
Bayesian criterion where the maximum a posteriori detector is optimal, the
Neyman-Pearson criterion with a constant type-I error probability constraint,
and the Neyman-Pearson criterion with an exponential type-I error probability
constraint. Leveraging recent development in distributed consensus reaching
using bounded quantizers with possibly unbounded data (which are log-likelihood
ratios of local observations in the context of distributed detection), we
design a one-bit deterministic quantizer with controllable threshold that leads
to desirable consensus error bounds. The obtained bounds are key to
establishing the optimal asymptotic detection performance. In addition, we
examine non-asymptotic performance of the proposed approach, and show that the
type-I and type-II error probabilities at each node can be made arbitrarily
close to the centralized ones simultaneously when a continuity condition is
satisfied.


title: The Classical Limit of Entropic Quantum Dynamics

abstract:
  The framework of entropic dynamics (ED) allows one to derive quantum
mechanics as an application of entropic inference. In this work we derive the
classical limit of quantum mechanics in the context of ED. Our goal is to find
conditions so that the center of mass (CM) of a system of N particles behaves
as a classical particle. What is of interest is that Planck's constant remains
finite at all steps in the calculation and that the classical motion is
obtained as the result of a central limit theorem. More explicitly we show that
if the system is sufficiently large, and if the CM is initially uncorrelated
with other degrees of freedom, then the CM follows a smooth trajectory and
obeys the classical Hamilton-Jacobi with a vanishing quantum potential.


title: Effective cycles on blow-ups of Grassmannians

abstract:
  In this paper we study the pseudoeffective cones of blow-ups of Grassmannians
at sets of points. For small numbers of points, the cones are often spanned by
proper transforms of Schubert classes. In some special cases, we provide sharp
bounds for when the Schubert classes fail to span and we describe the resulting
geometry.


title: KFAS: Exponential Family State Space Models in R

abstract:
  State space modelling is an efficient and flexible method for statistical
inference of a broad class of time series and other data. This paper describes
an R package KFAS for state space modelling with the observations from an
exponential family, namely Gaussian, Poisson, binomial, negative binomial and
gamma distributions. After introducing the basic theory behind Gaussian and
non-Gaussian state space models, an illustrative example of Poisson time series
forecasting is provided. Finally, a comparison to alternative R packages
suitable for non-Gaussian time series modelling is presented.


title:
Evidence of effective axial U(1) symmetry restoration at high
  temperature QCD

abstract:
  We study the axial U(1) symmetry at finite temperature in two-flavor lattice
QCD. Employing the Mobius domain-wall fermions, we generate gauge
configurations slightly above the critical temperature Tc with different
lattice sizes L = 2-4 fm. Our action allows frequent topology tunneling while
keeping good chiral symmetry close enough to that of overlap fermions. This
allows us to recover full chiral symmetry by an overlap/domain-wall
reweighting. Above the phase transition, a strong suppression of the low-lying
modes is observed in both of overlap and domain-wall Dirac spectra. We,
however, find a sizable violation of the Ginsparg-Wilson relation in the Mobius
domain-wall Dirac eigenmodes, which dominates the signals of the axial U(1)
symmetry breaking near the chiral limit. We also find that the use of overlap
fermion only in the valence sector is dangerous since it suffers from the
artifacts due to partial quenching. Reweighting the Mobius domain-wall fermion
determinant to that of the overlap fermion, we observe the axial U(1) breaking
to vanish in the chiral limit, which is stable against the changes of the
lattice volume and lattice spacing.


title: Exotic Signals of Vectorlike Quarks

abstract:
  Vectorlike fermions are an important target for hadron collider searches. We
show that the vectorlike quarks may predominantly decay via higher-dimensional
operators into a quark plus a couple of other Standard Model fermions. Pair
production of vectorlike quarks of charge 2/3 at the LHC would then lead to a
variety of possible final states, including $t\bar t + 4\tau$, $t\bar b\nu +
3\tau$, $t\bar t + 4\mu$, $t\bar b\nu + 3\mu$ or $t\bar t + 4b$. Additional
channels ($b\bar b + 4\tau$, $6b$, etc.) arise in the case of a vectorlike
quark of charge $-1/3$. If the vectorlike quark decays into three light quarks,
then the $(3j)(3j)$ signal is more difficult to observe, and the vectorlike
quark mass is almost unconstrained by current searches.


title:
Modular knowledge systems accelerate human migration in asymmetric
  random environments

abstract:
  Migration is a key mechanism for expansion of communities. In spatially
heterogeneous environments, rapidly gaining knowledge about the local
environment is key to the evolutionary success of a migrating population. For
historical human migration, environmental heterogeneity was naturally
asymmetric in the north-south (NS) and east-west (EW) directions. We here
consider the human migration process in the Americas, modeled as random,
asymmetric, modularly correlated environments. Knowledge about the environments
determines the fitness of each individual. We present a phase diagram for
asymmetry of migration as a function of carrying capacity and fitness
threshold. We find that the speed of migration is proportional to the inverse
complement of the spatial environmental gradient, and in particular we find
that north-south migration rates are lower than east-west migration rates when
the environmental gradient is higher in the north-south direction.
Communication of knowledge between individuals can help to spread beneficial
knowledge within the population. The speed of migration increases when
communication transmits pieces of knowledge that contribute in a modular way to
the fitness of individuals. The results for the dependence of migration rate on
asymmetry and modularity are consistent with existing archaeological
observations. The results for asymmetry of genetic divergence are consistent
with patterns of human gene flow.


title:
Lower bounds for the number of nodal domains for sums of two distorted
  plane waves in non-positive curvature

abstract:
  In this paper, we will consider generalised eigenfunctions of the Laplacian
on some surfaces of infinite area. We will be interested in lower bounds on the
number of nodal domains of such eigenfunctions which are included in a given
bounded set.
  We will first of all consider finite sums of plane waves, and give a
criterion on the amplitudes and directions of propagation of these plane waves
which guarantees an optimal lower bound, of the same order as Courant's upper
bound.
  As an application, we will obtain optimal lower bounds for the number of
nodal domains of distorted plane waves on some families of surfaces of
non-positive curvature.


title:
The magnetar model of the superluminous supernova GAIA16apd and the
  explosion jet feedback mechanism (JFM)

abstract:
  Under the assumption that jets explode core collapse supernovae in a negative
jet feedback mechanism (JFM), I show that rapidly rotating neutron stars are
likely to be formed when the explosion is very energetic. Under the assumption
that an accretion disk or an accretion belt around the just-formed neutron star
launch jets and that the accreted gas spins-up the just-formed neutron star, I
derive a crude relation between the energy that is stored in the spinning
neutron star and the explosion energy. This relation reads
Espin/Eexp~(Eexp/1e52erg). It shows that within the frame of the JFM explosion
model of core collapse supernovae, spinning neutron stars, such as magnetars,
might have significant energy in super-energetic explosions. The existence of
magnetars, if confirmed, such as in the recent super-energetic supernova
GAIA16apd, further supports the call for a paradigm shift from neutrino-driven
to jet-driven core-collapse supernova mechanisms.


title: Projective Space: Tetrads and Harmonicity

abstract:
  Within an axiomatic framework for three-dimensional projective space based on
lines alone, we explore the Fano axiom of harmonicity according to which the
diagonal lines of a complete quadrilateral are not concurrent.


title:
Generalized Skyrmions and hairy black holes in asymptotically AdS$_4$
  spacetime

abstract:
  We investigate the properties of spherically symmetric black hole solutions
in the generalized Einstein-Skyrme model theory in four-dimensional
asymptotically anti-de Sitter space-time. The dependencies of the Skyrmion
fields on the cosmological constant and on the strength of the effective
gravitational coupling are examined. We show that the increase of the absolute
value of the cosmological constant qualitatively yields the same effect as
increasing of the effective gravitational coupling. We confirm that, similar to
the model in the asymptotically flat space-time, a necessary condition for the
existence of black holes with Skyrmionic hair is the inclusion of the Skyrme
term.


title: Cosmic Chandlery with Thermonuclear Supernovae

abstract:
  Thermonuclear (Type Ia) supernovae are bright stellar explosions, the light
curves of which can be calibrated to allow for use as "standard candles" for
measuring cosmological distances. Contemporary research investigates how the
brightness of an event may be influenced by properties of the progenitor system
that follow from properties of the host galaxy such as composition and age. The
goals are to better understand systematic effects and to assess the intrinsic
scatter in the brightness, thereby reducing uncertainties in cosmological
studies. We present the results from ensembles of simulations in the
single-degenerate paradigm addressing the influence of age and metallicity on
the brightness of an event and compare our results to observed variations of
brightness that correlate with properties of the host galaxy. We also present
results from "hybrid" progenitor models that incorporate recent advances in
stellar evolution.


title:
Large gap asymptotics at the hard edge for product random matrices and
  Muttalib-Borodin ensembles

abstract:
  We study the distribution of the smallest eigenvalue for certain classes of
positive-definite Hermitian random matrices, in the limit where the size of the
matrices becomes large. Their limit distributions can be expressed as Fredholm
determinants of integral operators associated to kernels built out of Meijer
$G$-functions or Wright's generalized Bessel functions. They generalize in a
natural way the hard edge Bessel kernel Fredholm determinant. We express the
logarithmic derivatives of the Fredholm determinants identically in terms of a
$2\times 2$ Riemann-Hilbert problem, and use this representation to obtain the
so-called large gap asymptotics.


title: Physics objects for top physics in CMS

abstract:
  We present the status and performance of the physics objects with data
corresponding to an integrated luminosity of 12.9 inverse fb collected at 13
TeV by the CMS experiment. We cover the performance of the physics objects
extensively used in physics analyses involving top quarks.


title: High-Pressure Synthesis of a Pentazolate Salt

abstract:
  The pentazolates, the last all-nitrogen members of the azole series, have
been notoriously elusive for the last hundred years despite enormous efforts to
make these compounds in either gas or condensed phases. Here we report a
successful synthesis of a solid state compound consisting of isolated
pentazolate anions N5-, which is achieved by compressing and laser heating
cesium azide (CsN3) mixed with N2 cryogenic liquid in a diamond anvil cell. The
experiment was guided by theory, which predicted the transformation of the
mixture at high pressures to a new compound, cesium pentazolate salt (CsN5).
Electron transfer from Cs atoms to N5 rings enables both aromaticity in the
pentazolates as well as ionic bonding in the CsN5 crystal. This work provides a
critical insight into the role of extreme conditions in exploring unusual
bonding routes that ultimately lead to the formation of novel high nitrogen
content species.


title: Low degree Hodge theory for klt varieties

abstract:
  If X is a complex projective variety with klt singularities, then the mixed
Hodge structures on the first two singular cohomology groups are pure. We
describe the pieces of the Hodge decomposition in terms of reflexive
differential forms. Applications include a Lefschetz (1,1) Theorem and a weak
analogue of the Hodge-Riemann bilinear relations for klt varieties.


title:
Combined atomic force microscopy and photoluminescence imaging to select
  single InAs/GaAs quantum dots for quantum photonic devices

abstract:
  We report on a combined photoluminescence imaging and atomic force microscopy
study of single, isolated self-assembled InAs quantum dots (density <0.01
um^(-2) capped by a 95 nm GaAs layer, and emitting around 950 nm. By combining
optical and scanning probe characterization techniques, we determine the
position of single quantum dots with respect to comparatively large (100 nm to
1000 nm in-plane dimension) topographic features. We find that quantum dots
often appear (>25% of the time) in the vicinity of these features, but
generally do not exhibit significant differences in their non-resonantly pumped
emission spectra in comparison to quantum dots appearing in defect-free
regions. This behavior is observed across multiple wafers produced in different
growth chambers. Our characterization approach is relevant to applications in
which single quantum dots are embedded within nanofabricated photonic devices,
where such large surface features can affect the interaction with confined
optical fields and the quality of the single-photon emission. In particular, we
anticipate using this approach to screen quantum dots not only based on their
optical properties, but also their surrounding surface topographies.


title: A thermodynamic point of view on dark energy models

abstract:
  We present a conjugate analysis of two different dark energy models
investigating both their agreement with recent data and their thermodynamical
properties. The successful match with the data allows to both constrain the
model parameters and characterize their kinematical properties. As a novel
step, we exploit the strong connection between gravity and thermodynamics to
further check models viability by investigating their thermodynamical
quantities. In particular, we study whether the cosmological scenario fulfills
the generalized second law of thermodynamics and, moreover, we contrast the two
model asking whether the evolution of the total entropy is in agreement with
the expectation for a closed system. As a general result, we discuss whether
thermodynamic constraints can be a valid complementary way to both constrain
dark energy models and differentiate among rival scenarios.


title: Tag Prediction at Flickr: a View from the Darkroom

abstract:
  Automated photo tagging has established itself as one of the most compelling
applications of deep learning. While deep convolutional neural networks have
repeatedly demonstrated top performance on standard datasets for
classification, there are a number of often overlooked but important
considerations when deploying this technology in a real-world scenario. In this
paper, we present our efforts in developing a large-scale photo tagging system
for Flickr photo search. We discuss topics including how to 1) select the tags
that matter most to our users; 2) develop lightweight, high-performance models
for tag prediction; and 3) leverage the power of large amounts of noisy data
for training. Our results demonstrate that, for real-world datasets, training
exclusively with this noisy data yields performance on par with the standard
paradigm of first pre-training on clean data and then fine-tuning. In addition,
we observe that the models trained with user-generated data can yield better
fine-tuning results when a small amount of clean data is available. As such, we
advocate for the approach of harnessing user-generated data in large-scale
systems.


title:
XMM-Newton observation of the supernova remnant Kes 78 (G32.8-0.1):
  Evidence for shock-cloud interaction

abstract:
  The Galactic supernova remnant Kes 78 is surrounded by dense molecular
clouds, whose projected position overlaps with the extended HESS gamma-ray
source HESS J1852-000. The X-ray emission from the remnant has been recently
revealed by Suzaku observations, which have shown indications for a hard X-ray
component in the spectra, possibly associated with synchrotron radiation. We
aim at describing the spatial distribution of the physical properties of the
X-ray emitting plasma and at revealing the effects of the interaction of the
remnant with the inhomogeneous ambient medium. We also aim at investigating the
origin of the gamma-ray emission, which may be Inverse Compton radiation
associated with X-ray synchrotron emitting electrons or hadronic emission
originating from the impact of high energy protons on the nearby clouds. We
analyzed an XMM-Newton EPIC observation of Kes 78 by performing image analysis
and spatially resolved spectral analysis on a set of three regions. We tested
our findings against the observations of the 12CO and 13CO emission in the
environment of the remnant. We revealed the complex X-ray morphology of Kes 78
and found variations of the spectral properties of the plasma, with
significantly denser and cooler material at the eastern edge of the remnant,
which we interpret as a signature of interaction with a molecular cloud. We
also exclude the presence of narrow filaments emitting X-ray synchrotron
radiation. Assuming that the very high energy gamma-ray emission is associated
with Kes 78, the lack of synchrotron emission rules out a leptonic origin. A
hadronic origin is further supported by evidence for interaction of the remnant
with a dense molecular cloud in its eastern limb.


title: Bounded linear endomorphisms of rigid analytic functions

abstract:
  Let $K$ be a field of characteristic zero complete with respect to a
non-trivial, non-Archimedean valuation. We relate the sheaf
$\widehat{\mathcal{D}}$ of infinite order differential operators on smooth
rigid $K$-analytic spaces to the algebra $\mathcal{E}$ of bounded $K$-linear
endomorphisms of the structure sheaf. In the case of complex manifolds,
Ishimura proved that the analogous sheaves are isomorphic. In the rigid
analytic situation, we prove that the natural map $\widehat{\mathcal{D}} \to
\mathcal{E}$ is an isomorphism if and only if the ground field $K$ is
algebraically closed and its residue field is uncountable.


title: FlowNet 2.0: Evolution of Optical Flow Estimation with Deep Networks

abstract:
  The FlowNet demonstrated that optical flow estimation can be cast as a
learning problem. However, the state of the art with regard to the quality of
the flow has still been defined by traditional methods. Particularly on small
displacements and real-world data, FlowNet cannot compete with variational
methods. In this paper, we advance the concept of end-to-end learning of
optical flow and make it work really well. The large improvements in quality
and speed are caused by three major contributions: first, we focus on the
training data and show that the schedule of presenting data during training is
very important. Second, we develop a stacked architecture that includes warping
of the second image with intermediate optical flow. Third, we elaborate on
small displacements by introducing a sub-network specializing on small motions.
FlowNet 2.0 is only marginally slower than the original FlowNet but decreases
the estimation error by more than 50%. It performs on par with state-of-the-art
methods, while running at interactive frame rates. Moreover, we present faster
variants that allow optical flow computation at up to 140fps with accuracy
matching the original FlowNet.


title:
Transition Probability for Class of Two Level System Time Dependent
  Hamiltonians

abstract:
  Transition probabilities for a class of two level systems described by
explicitly time dependent Hamiltonians are considered. Provided only that the
approach to the infinite time limit is non-trivial falling at least as fast as
1/t for large t, the transition probability takes a particularly simple form
depending only on the value of Hamiltonian parameters in this limit.


title: Spin-Hall Torques Generated by Rare-Earth (Lanthanide) Thin Films

abstract:
  We report an initial experimental survey of spin-Hall torques generated by
the rare-earth metals Gd, Dy, Ho, and Lu, along with comparisons to
first-principles calculations of their spin Hall conductivities. Using spin
torque ferromagnetic resonance (ST-FMR) measurements and DC-biased ST-FMR, we
estimate lower bounds for the spin-Hall torque ratio, $\xi_{SH}$, of $\approx$
0.04 for Gd, $\approx$ 0.05 for Dy, $\approx$ 0.14 for Ho, and $\approx$ 0.014
for Lu. The variations among these elements are qualitatively consistent with
results from first principles (density functional theory, DFT, in the local
density approximation with a Hubbard-U correction). The DFT calculations
indicate that the spin Hall conductivity is enhanced by the presence of the
partially-filled $f$ orbitals in Dy and Ho, which suggests a strategy to
further strengthen the contribution of the $f$ orbitals to the spin Hall effect
by shifting the electron chemical potential.


title: Invariant Representations for Noisy Speech Recognition

abstract:
  Modern automatic speech recognition (ASR) systems need to be robust under
acoustic variability arising from environmental, speaker, channel, and
recording conditions. Ensuring such robustness to variability is a challenge in
modern day neural network-based ASR systems, especially when all types of
variability are not seen during training. We attempt to address this problem by
encouraging the neural network acoustic model to learn invariant feature
representations. We use ideas from recent research on image generation using
Generative Adversarial Networks and domain adaptation ideas extending
adversarial gradient-based training. A recent work from Ganin et al. proposes
to use adversarial training for image domain adaptation by using an
intermediate representation from the main target classification network to
deteriorate the domain classifier performance through a separate neural
network. Our work focuses on investigating neural architectures which produce
representations invariant to noise conditions for ASR. We evaluate the proposed
architecture on the Aurora-4 task, a popular benchmark for noise robust ASR. We
show that our method generalizes better than the standard multi-condition
training especially when only a few noise categories are seen during training.


title: Sumsets as unions of sumsets of subsets

abstract:
  Let $S$ and $T$ be subsets of $\mathbf{F}_q^n$. We show there are subsets
$S'$ of $S$ and $T'$ of $T$ such that $S+T$ is the union of $S+T'$ and $S'+T$,
with $|S'| + |T'|$ bounded by $c^n$ with $c < q$. The proof relies on the
method of Croot-Lev-Pach and Ellenberg-Gijswijt on the cap set problem,
together with a result of Meshulam on linear spaces of low-rank matrices. The
result is a modest generalization of the recent bounds on (single-colored and
multi-colored) sum-free sets by the author and others.


title: Nonparametric Bayesian label prediction on a graph

abstract:
  An implementation of a nonparametric Bayesian approach to solving binary
classification problems on graphs is described. A hierarchical Bayesian
approach with a randomly scaled Gaussian prior is considered. The prior uses
the graph Laplacian to take into account the underlying geometry of the graph.
A method based on a theoretically optimal prior and a more flexible variant
using partial conjugacy are proposed. Two simulated data examples and two
examples using real data are used in order to illustrate the proposed methods.


title: Quantum Decoherence of Phonons in Bose-Einstein Condensates

abstract:
  We apply modern techniques from quantum optics and quantum information
science to Bose-Einstein Condensates (BECs) in order to study, for the first
time, the quantum decoherence of phonons of isolated BECs. In the last few
years, major advances in the manipulation and control of phonons have
highlighted their potential as carriers of quantum information in quantum
technologies, particularly in quantum processing and quantum communication.
Although most of these studies have focused on trapped ion and crystalline
systems, another promising system that has remained relatively unexplored is
BECs. The potential benefits in using this system have been emphasized recently
with proposals of relativistic quantum devices that exploit quantum states of
phonons in BECs to achieve, in principle, superior performance over standard
non-relativistic devices. Quantum decoherence is often the limiting factor in
the practical realization of quantum technologies, but here we show that
quantum decoherence of phonons is not expected to heavily constrain the
performance of these proposed relativistic quantum devices.


title:
Asymptotically sharp reverse H\"older inequalities for flat Muckenhoupt
  weights

abstract:
  We present reverse H\"older inequalities for Muckenhoupt weights in
$\mathbb{R}^n$ with an asymptotically sharp behavior for flat weights, namely
$A_\infty$ weights with Fujii-Wilson constant $(w)_{A_\infty}\to 1^+$. That is,
the local integrability exponent in the reverse H\"older inequality blows up as
the weight becomes nearly constant. This is expressed in a precise and explicit
computation of the constants involved in the reverse H\"older inequality. The
proofs avoid BMO methods and rely instead on precise covering arguments.
Furthermore, in the one-dimensional case we prove sharp reverse H\"older
inequalities for one-sided and two sided weights in the sense that both the
integrability exponent as well as the multiplicative constant appearing in the
estimate are best possible. We also prove sharp endpoint weak-type reverse
H\"older inequalities and consider further extensions to general non-doubling
measures and multiparameter weights.


title:
Extended relativistic Toda lattice, L-orthogonal polynomials and
  associated Lax pair

abstract:
  When a measure $\psi(x)$ on the real line is subjected to the modification
$d\psi^{(t)}(x) = e^{-tx} d \psi(x)$, then the coefficients of the recurrence
relation of the orthogonal polynomials in $x$ with respect to the measure
$\psi^{(t)}(x)$ are known to satisfy the so-called Toda lattice formulas as
functions of $t$. In this paper we consider a modification of the form $e^{-t(p
x+q/x)}$ of measures or, more generally, of moment functionals, associated with
orthogonal L-polynomials and show that the coefficients of the recurrence
relation of these L-orthogonal polynomials satisfy what we call an extended
relativistic Toda lattice. Most importantly, we also establish the so called
Lax pair representation associated with this extended relativistic Toda
lattice. These results also cover the (ordinary) relativistic Toda lattice
formulations considered in the literature by assuming either $p =0$ or $q=0$.
However, as far as Lax pair representation is concern, no complete Lax pair
representations were established for the respective relativistic Toda lattice
formulations. Some explicit examples of extended relativistic Toda lattice and
Langmuir lattice are also presented. As further results, the lattice formulas
that follow from the three term recurrence relations associated with kernel
polynomials on the unit circle are also established


title: A stochastic process approach to multilayer neutron detectors

abstract:
  The sparsity of the isotope Helium-3, ongoing since 2009, has initiated a new
generation of neutron detectors. One particularly promising development line
for detectors is the multilayer gaseous detector. In this paper, a stochastic
process approach is used to determine the neutron's energy from the additional
data afforded by the multilayer nature of these novel detectors.
  The data from a multi-layer detector consists of counts of the number of
absorbed neutrons along the sequence of the detector's layers, in which the
neutron absorption probability is unknown. We study the Maximum Likelihood
estimator for the intensity and absorption probability, show its consistency
and asymptotic normality, as the experiment time (or the number of incoming
neutrons) goes to infinity. We combine these results with known results on the
relation between the absorption probability and the wavelength to derive an
estimator of the wavelength and to show consistency and asymptotic normality
for the estimator.


title:
Dynamical and Radiative Properties of X-ray Pulsar Accretion Columns:
  Phase-Averaged Spectra

abstract:
  The availability of the unprecedented spectral resolution provided by modern
X-ray observatories is opening up new areas for study involving the coupled
formation of the continuum emission and the cyclotron absorption features in
accretion-powered X-ray pulsar spectra. Previous research focusing on the
dynamics and the associated formation of the observed spectra has largely been
confined to the single-fluid model, in which the super-Eddington luminosity
inside the column decelerates the flow to rest at the stellar surface, while
the dynamical effect of gas pressure is ignored. In a companion paper, we have
presented a detailed analysis of the hydrodynamic and thermodynamic structure
of the accretion column obtained using a new self-consistent model that
includes the effects of both gas and radiation pressure. In this paper, we
explore the formation of the associated X-ray spectra using a rigorous photon
transport equation that is consistent with the hydrodynamic and thermodynamic
structure of the column. We use the new model to obtain phase-averaged spectra
and partially-occulted spectra for Her X-1, Cen X-3, and LMC X-4. We also use
the new model to constrain the emission geometry, and compare the resulting
parameters with those obtained using previously published models. Our model
sheds new light on the structure of the column, the relationship between the
ionized gas and the photons, the competition between diffusive and advective
transport, and the magnitude of the energy-averaged cyclotron scattering cross
section.


title: A Probabilistic Framework for Deep Learning

abstract:
  We develop a probabilistic framework for deep learning based on the Deep
Rendering Mixture Model (DRMM), a new generative probabilistic model that
explicitly capture variations in data due to latent task nuisance variables. We
demonstrate that max-sum inference in the DRMM yields an algorithm that exactly
reproduces the operations in deep convolutional neural networks (DCNs),
providing a first principles derivation. Our framework provides new insights
into the successes and shortcomings of DCNs as well as a principled route to
their improvement. DRMM training via the Expectation-Maximization (EM)
algorithm is a powerful alternative to DCN back-propagation, and initial
training results are promising. Classification based on the DRMM and other
variants outperforms DCNs in supervised digit classification, training 2-3x
faster while achieving similar accuracy. Moreover, the DRMM is applicable to
semi-supervised and unsupervised learning tasks, achieving results that are
state-of-the-art in several categories on the MNIST benchmark and comparable to
state of the art on the CIFAR10 benchmark.


title:
Next-to-leading order corrections to deeply virtual production of
  pseudoscalar mesons

abstract:
  We complete the perturbative next-to-leading order corrections to the hard
scattering amplitudes of deeply virtual meson leptoproduction processes at
leading twist-two level by presenting the results for the production of flavor
singlet pseudoscalar mesons. The new results are given in the common momentum
fraction representation and in terms of conformal moments. We also comment on
the flavor singlet results for deeply virtual vector meson production.


title:
Extension of a factorization method of nonlinear second order ODE's with
  variable coefficients

abstract:
  The factorization of nonlinear second-order differential equations proposed
by Rosu and Cornejo-Perez in 2005 is extended to equations containing quadratic
and cubic forms in the first derivative. A few illustrative examples
encountered in physics are provided.


title: Correlation Alignment for Unsupervised Domain Adaptation

abstract:
  In this chapter, we present CORrelation ALignment (CORAL), a simple yet
effective method for unsupervised domain adaptation. CORAL minimizes domain
shift by aligning the second-order statistics of source and target
distributions, without requiring any target labels. In contrast to subspace
manifold methods, it aligns the original feature distributions of the source
and target domains, rather than the bases of lower-dimensional subspaces. It is
also much simpler than other distribution matching methods. CORAL performs
remarkably well in extensive evaluations on standard benchmark datasets. We
first describe a solution that applies a linear transformation to source
features to align them with target features before classifier training. For
linear classifiers, we propose to equivalently apply CORAL to the classifier
weights, leading to added efficiency when the number of classifiers is small
but the number and dimensionality of target examples are very high. The
resulting CORAL Linear Discriminant Analysis (CORAL-LDA) outperforms LDA by a
large margin on standard domain adaptation benchmarks. Finally, we extend CORAL
to learn a nonlinear transformation that aligns correlations of layer
activations in deep neural networks (DNNs). The resulting Deep CORAL approach
works seamlessly with DNNs and achieves state-of-the-art performance on
standard benchmark datasets. Our code is available
at:~\url{https://github.com/VisionLearningGroup/CORAL}


title:
A de Haas van Alphen study of the role of 4f electrons in
  antiferromagnetic CeZn11 as compared to its non-magnetic analogue LaZn11

abstract:
  We present a de Haas-van Alphen study of the Fermi surface of the low
temperature antiferromagnet CeZn11 and its non-magnetic analogue LaZn11,
measured by torque magnetometry up to fields of 33T and at temperatures down to
320 mK. Both systems possess similar de Haas-van Alphen frequencies, with three
clear sets of features - ranging from 50T to 4kT - corresponding to three bands
of a complex Fermi surface, with an expected fourth band also seen weakly in
CeZn11. The effective masses of the charge carriers are very light (<1 me) in
LaZn11 but a factor of 2 - 4 larger in CeZn11, indicative of stronger
electronic correlations. We perform detailed density functional theory (DFT)
calculations for CeZn11 and find that only DFT+U calculations with U=1.5 eV,
which localize the 4f states, provide a good match to the measured de Haas-van
Alphen frequencies, once the presence of magnetic breakdown orbits is also
considered. Our study suggests that the Fermi surface of CeZn11 is very close
to that of LaZn11 being dominated by Zn 3d, as the Ce 4f states are localised
and have little influence on its electronic structure, however, they are
responsible for its magnetic order and contribute to enhance electronic
correlations.


title: Coactive Critiquing: Elicitation of Preferences and Features

abstract:
  When faced with complex choices, users refine their own preference criteria
as they explore the catalogue of options. In this paper we propose an approach
to preference elicitation suited for this scenario. We extend Coactive
Learning, which iteratively collects manipulative feedback, to optionally query
example critiques. User critiques are integrated into the learning model by
dynamically extending the feature space. Our formulation natively supports
constructive learning tasks, where the option catalogue is generated
on-the-fly. We present an upper bound on the average regret suffered by the
learner. Our empirical analysis highlights the promise of our approach.


title: Semi-Supervised Learning with the Deep Rendering Mixture Model

abstract:
  Semi-supervised learning algorithms reduce the high cost of acquiring labeled
training data by using both labeled and unlabeled data during learning. Deep
Convolutional Networks (DCNs) have achieved great success in supervised tasks
and as such have been widely employed in the semi-supervised learning. In this
paper we leverage the recently developed Deep Rendering Mixture Model (DRMM), a
probabilistic generative model that models latent nuisance variation, and whose
inference algorithm yields DCNs. We develop an EM algorithm for the DRMM to
learn from both labeled and unlabeled data. Guided by the theory of the DRMM,
we introduce a novel non-negativity constraint and a variational inference
term. We report state-of-the-art performance on MNIST and SVHN and competitive
results on CIFAR10. We also probe deeper into how a DRMM trained in a
semi-supervised setting represents latent nuisance variation using
synthetically rendered images. Taken together, our work provides a unified
framework for supervised, unsupervised, and semi-supervised learning.


title:
Segmental Convolutional Neural Networks for Detection of Cardiac
  Abnormality With Noisy Heart Sound Recordings

abstract:
  Heart diseases constitute a global health burden, and the problem is
exacerbated by the error-prone nature of listening to and interpreting heart
sounds. This motivates the development of automated classification to screen
for abnormal heart sounds. Existing machine learning-based systems achieve
accurate classification of heart sound recordings but rely on expert features
that have not been thoroughly evaluated on noisy recordings. Here we propose a
segmental convolutional neural network architecture that achieves automatic
feature learning from noisy heart sound recordings. Our experiments show that
our best model, trained on noisy recording segments acquired with an existing
hidden semi-markov model-based approach, attains a classification accuracy of
87.5% on the 2016 PhysioNet/CinC Challenge dataset, compared to the 84.6%
accuracy of the state-of-the-art statistical classifier trained and evaluated
on the same dataset. Our results indicate the potential of using neural
network-based methods to increase the accuracy of automated classification of
heart sound recordings for improved screening of heart diseases.


title:
Porous Structure Design in Tissue Engineering Using Anisotropic Radial
  Basis Function

abstract:
  Development of additive manufacturing in last decade greatly improves tissue
engineering. During the manufacturing of porous scaffold, simplified but
functionally equivalent models are getting focused for practically reasons.
Scaffolds can be classified into regular porous scaffolds and irregular porous
scaffolds. Several methodologies are developed to design these scaffolds. A
novel method is proposed in this paper using anisotropic radial basis function
(ARBF) interpolation. This is method uses geometric models such as volumetric
meshes as input and proves to be flexible because geometric models are able to
capture the characteristics of complex tissues easily. Moreover, this method is
straightforward and easy to implement.


title: Black Hole Area Quantization rule from Black Hole Mass Fluctuations

abstract:
  We calculate the black hole mass distribution function that follows from the
random emission of quanta by Hawking radiation and with this function we
calculate the black hole mass fluctuation. From a complete different
perspective we regard the black hole as quantum mechanical system with a
quantized event horizon area and transition probabilities among the various
energy levels and then calculate the mass dispersion. It turns out that there
is a perfect agreement between the statistical and the microscopic calculations
if and only if the area spectrum is linear. Accordingly, the quantum mechanical
properties of the black hole which are supposedly relevant only at Planckian
scales do leave an imprint in the black hole mass dispersion at much larger
scales where gravity can be dealt classically, as one would expect from the
correspondence principle.


title: Dipole-dipole dispersion interactions between neutrons

abstract:
  We investigate the long-range interactions between two neutrons utilizing
recent data on the neutron static and dynamic electric and magnetic dipole
polarizabilities. The resulting long-range potentials are used to make
quantitative comparisons between the collisions of a neutron with a neutron and
a neutron with a proton. We also assess the importance of the first pion
production threshold and first excited state of the nucleon, the
$\Delta$-resonance ($J^{\pi}$ = + 3/2, I = 3/2). We found both dynamical
effects to be quite relevant for distances r between ~ 50 fm up to ~$10^3$ fm
in the nn system, the neutron-wall system and in the wall-neutron-wall system,
reaching the expected asymptotic limit beyond that. Relevance of our findings
to the confinement of ultra cold neutrons inside bottles is discussed.


title: One-dimensional irreversible aggregation with TASEP dynamics

abstract:
  We define and study one-dimensional model of irreversible aggregation of
particles obeying a discrete-time kinetics which is a special limit of the
generalized Totally Asymmetric Simple Exclusion Process (gTASEP) on open
chains. The model allows for clusters of particles to translate as a whole
entity one site to the right with the same probability as single particles do.
A particle and a cluster, as well as two clusters, irreversibly aggregate
whenever they become nearest neighbors. Nonequilibrium stationary phases appear
under the balance of injection and ejection of particles. By extensive Monte
Carlo simulations it is established that the phase diagram in the plane of the
injection-ejection probabilities consists of three stationary phases: a
multi-particle (MP) one, a completely filled (CF) phase and a 'mixed' (MP+CF)
one. The transitions between these phases are: an unusual transition between MP
and CF with jump discontinuity in both the bulk density and the current, a
conventional first-order transition with a jump in the bulk density between MP
and MP+CF, and a continuous clustering-type transition from MP to CF, which
takes place throughout the MP+CF phase between them. By the data collapse
method a finite-size scaling function for the current and bulk density is
obtained near the unusual phase transition line. A diverging correlation length
associated with that transition is identified and interpreted as the size of
the largest cluster. The model allows for a future extension to account for
possible cluster fragmentation.


title:
A new method to quantify and reduce projection error in
  whole-solar-active-region parameters measured from vector magnetograms

abstract:
  Projection error limits the use of vector magnetograms of active regions
(ARs) far from disk center. In this Letter, for ARs observed up to 60o from
disk center, we demonstrate a method of measuring and reducing the projection
error in the magnitude of any whole-AR parameter derived from a vector
magnetogram that has been deprojected to disk center. The method assumes that
the center-to-limb curve of the average of the parameter's absolute values
measured from the disk passage of a large number of ARs and normalized to each
AR's absolute value of the parameter at central meridian, gives the average
fractional projection error at each radial distance from disk center. To
demonstrate the method, we use a large set of large-flux ARs and apply the
method to a whole-AR parameter that is among the simplest to measure: whole-AR
magnetic flux. We measure 30,845 SDO/HMI vector magnetograms covering the disk
passage of 272 large-flux ARs, each having whole-AR flux >1022 Mx. We obtain
the center-to-limb radial-distance run of the average projection error in
measured whole-AR flux from a Chebyshev fit to the radial-distance plot of the
30,845 normalized measured values. The average projection error in the measured
whole-AR flux of an AR at a given radial distance is removed by multiplying the
measured flux by the correction factor given by the fit. The correction is
important for both the study of evolution of ARs and for improving the accuracy
of forecasting an AR's major flare/CME productivity.


title:
Equation of Motion for the Solvent Polarization Apparent Charges in the
  Polarizable Continuum Model: Application to Time-Dependent CI

abstract:
  The dynamics of the electrons for a molecule in solution is coupled to the
dynamics of its polarizable environment, i.e., the solvent. To theoretically
investigate such electronic dynamics, we have recently developed equations of
motion (EOM) for the apparent solvent polarization charges that generate the
reaction field in the Polarizable Continuum Model (PCM) for solvation and we
have coupled them to a real-time time-dependent density functional theory (RT
TDDFT) description of the solute [Corni et al. J. Phys. Chem. A 119, 5405
(2014)]. Here we present an extension of the EOM-PCM approach to a
Time-Dependent Configuration Interaction (TD CI) description of the solute
dynamics, which is free from the qualitative artifacts of RT TDDFT in the
adiabatic approximation. As tests of the developed approach, we investigate the
solvent Debye relaxation after an electronic excitation of the solute obtained
either by a $\pi$ pulse of light or by assuming the idealized sudden promotion
to the excited state. Moreover, we present EOM for the Onsager solvation model
and we compare the results with PCM. The developed approach provides
qualitatively correct real-time evolutions and is promising as a general tool
to investigate the electron dynamics elicited by external electromagnetic
fields for molecules in solution.


title: A category of hybrid systems

abstract:
  We propose a definition of the category of hybrid systems in which executions
are special types of morphisms. Consequently morphisms of hybrid systems send
executions to executions.
  We plan to use this result to define and study networks of hybrid systems.


title: Stability of calibration procedures: fractals in the Black-Scholes model

abstract:
  Usually, in the Black-Scholes pricing theory the volatility is a positive
real parameter. Here we explore what happens if it is allowed to be a complex
number. The function for pricing a European option with a complex volatility
has essential singularities at zero and infinity. The singularity at zero
reflects the put-call parity. Solving for the implied volatility that
reproduces a given market price yields not only a real root, but also
infinitely many complex roots in a neighbourhood of the origin. The
Newton-Raphson calculation of the complex implied volatility has a chaotic
nature described by fractals.


title: Why Our Universe is Comprehensible

abstract:
  Einstein wrote memorably that `The eternally incomprehensible thing about the
world is its comprehensibility.' This paper argues that the universe must be
comprehensible at some level for information gathering and utilizing subsystems
such as human observers to evolve and function.


title:
The good, the bad and the ugly coherent states through polynomial
  Heisenberg algebras

abstract:
  Second degree polynomial Heisenberg algebras are realized through the
harmonic oscillator Hamiltonian, together with two deformed ladder operators
chosen as the third powers of the standard annihilation and creation operators.
The corresponding solutions to the Painleve IV equation are easily found.
Moreover, three different sets of eigenstates of the deformed annihilation
operator are constructed, called the good, the bad and the ugly coherent
states. Some physical properties of such states will be as well studied.


title: Increased low-temperature damping in yttrium iron garnet thin films

abstract:
  We report measurements of the frequency and temperature dependence of
ferromagnetic resonance (FMR) for a 15-nm-thick yttrium iron garnet (YIG) film
grown by off-axis sputtering. Although the FMR linewidth is narrow at room
temperature (corresponding to a damping coefficient $\alpha$ = (9.0 $\pm$ 0.2)
$\times 10^{-4}$), comparable to previous results for high-quality YIG films of
similar thickness, the linewidth increases strongly at low temperatures, by a
factor of almost 30. This increase cannot be explained as due to two-magnon
scattering from defects at the sample interfaces. We argue that the increased
low-temperature linewidth is due to impurity relaxation mechanisms that have
been investigated previously in bulk YIG samples. We suggest that the
low-temperature linewidth is a useful figure of merit to guide the optimization
of thin-film growth protocols because it is a particularly sensitive indicator
of impurities.


title: Random dynamical systems, rough paths and rough flows

abstract:
  We analyze common lifts of stochastic processes to rough paths/rough
drivers-valued processes and give sufficient conditions for the cocycle
property to hold for these lifts. We show that random rough differential
equations driven by such lifts induce random dynamical systems. In particular,
our results imply that rough differential equations driven by the lift of
fractional Brownian motion in the sense of Friz-Victoir induce random dynamical
systems.


title: G181.1+9.5, a new high-latitude low-surface brightness supernova remnant

abstract:
  More than 90% of the known Milky Way supernova remnants are within 5 degrees
of the Galactic Plane. We present the discovery of the supernova remnant
G181.1+9.5, a new high-latitude SNR, serendipitously discovered in an ongoing
survey of the Galactic Anti-centre High-Velocity Cloud complex, observed with
the DRAO Synthesis Telescope in the 21~cm radio continuum and HI spectral line.
We use radio continuum observations (including the linearly polarized
component) at 1420~MHz (observed with the DRAO ST) and 4850~MHz (observed with
the Effelsberg 100-m radio telescope) to map G181.1+9.5 and determine its
nature as a SNR. High-resolution 21~cm HI line observations and HI emission and
absorption spectra reveal the physical characteristics of its local
interstellar environment. Finally, we estimate the basic physical parameters of
G181.1+9.5 using models for highly-evolved SNRs. G181.1+9.5 has a circular
shell-like morphology with a radius of about 16~pc at a distance of 1.5 kpc
some 250 pc above the mid-plane. The radio observations reveal highly linearly
polarized emission with a non-thermal spectrum. Archival ROSAT X-ray data
reveal high-energy emission from the interior of G181.1+9.5 indicative of the
presence of shock-heated ejecta. The SNR is in the advanced radiative phase of
SNR evolution, expanding into the HVC inter-cloud medium with a density of
1$~cm$^{-3}$. Basic physical attributes of G181.1+9.5 calculated with radiative
SNR models show an upper-limit age of 16,000 years, a swept-up mass of more
than 300 solar masses, and an ambient density in agreement with that estimated
from HI observations. G181.1+9.5 shows all characteristics of a typical mature
shell-type SNR, but its observed faintness is unusual and requires further
study.


title: Untangling galaxy components: full spectral bulge-disc decomposition

abstract:
  To ascertain whether photometric decompositions of galaxies into bulges and
disks are astrophysically meaningful, we have developed a new technique to
decompose spectral data cubes into separate bulge and disk components, subject
only to the constraint that they reproduce the conventional photometric
decomposition. These decompositions allow us to study the kinematic and stellar
population properties of the individual components and how they vary with
position, in order to assess their plausibility as discrete elements, and to
start to reconstruct their distinct formation histories. An initial application
of this method to CALIFA integral field unit observations of three isolated S0
galaxies confirms that in regions where both bulge and disc contribute
significantly to the flux they can be physically and robustly decomposed into a
rotating dispersion-dominated bulge component, and a rotating low-dispersion
disc component. Analysis of the resulting stellar populations shows that the
bulges of these galaxies have a range of ages relative to their discs,
indicating that a variety of processes are necessary to describe their
evolution. This simple test case indicates the broad potential for extracting
from spectral data cubes the full spectral data of a wide variety of individual
galaxy components, and for using such decompositions to understand the
interplay between these various structures, and hence how such systems formed.


title: Learning Diverse Image Colorization

abstract:
  Colorization is an ambiguous problem, with multiple viable colorizations for
a single grey-level image. However, previous methods only produce the single
most probable colorization. Our goal is to model the diversity intrinsic to the
problem of colorization and produce multiple colorizations that display
long-scale spatial co-ordination. We learn a low dimensional embedding of color
fields using a variational autoencoder (VAE). We construct loss terms for the
VAE decoder that avoid blurry outputs and take into account the uneven
distribution of pixel colors. Finally, we build a conditional model for the
multi-modal distribution between grey-level image and the color field
embeddings. Samples from this conditional model result in diverse colorization.
We demonstrate that our method obtains better diverse colorizations than a
standard conditional variational autoencoder (CVAE) model, as well as a
recently proposed conditional generative adversarial network (cGAN).


title: On the physics of propagating Bessel modes in cylindrical waveguides

abstract:
  In this paper we demonstrate that using a mathematical physics approach
(focusing the attention to the physics and using mathematics as a tool) it is
possible to visualize the formation of the transverse modes inside a
cylindrical waveguide. In opposition, the physical mathematics solutions
(looking at the mathematical problem and then trying to impose a physical
interpretation), when studying cylindrical waveguides yields to the Bessel
differential equation and then it is argued that in the core are only the
Bessel functions of the first kind those who describe the transverse modes. And
the Neumann functions are deemed non physical due to its singularity at the
origin and eliminated from the final description of the solution. In this paper
we show, using a geometrical-wave optics approach, that the inclusion of this
function is physically necessary to describe fully and properly the formation
of the propagating transverse modes. Also, the field in the outside of a
dielectric waveguide arises in a natural way.


title: Characterization of Koll\'ar surfaces

abstract:
  Koll\'ar introduced in [Ko08] the surfaces
$$(x_1^{a_1}x_2+x_2^{a_2}x_3+x_3^{a_3}x_4+x_4^{a_4}x_1=0)\subset
\mathbb{P}(w_1,w_2,w_3,w_4)$$ where $w_i=W_i/w^*$,
$W_i=a_{i+1}a_{i+2}a_{i+3}-a_{i+2}a_{i+3}+a_{i+3}-1$, and
$w^*=$gcd$(W_1,\ldots,W_4)$. The aim was to give many interesting examples of
$\mathbb{Q}$-homology projective planes. They occur when $w^*=1$. For that
case, we prove that Koll\'ar surfaces are Hwang-Keum [HK12] surfaces. For
$w^*>1$, we construct a geometrically explicit birational map between Koll\'ar
surfaces and cyclic covers $z^{w^*}=l_1^{a_2 a_3 a_4} l_2^{-a_3 a_4} l_3^{a_4}
l_4^{-1}$, where $\{l_1,l_2,l_3,l_4\}$ are four general lines in
$\mathbb{P}^2$. In addition, by using various properties on classical Dedekind
sums, we prove that:
  (a) For any $w^*>1$, we have $p_g=0$ iff the Koll\'ar surface is rational.
This happens when $a_{i+1} \equiv 1$ or $a_{i}a_{i+1} \equiv -1 ($mod $w^*)$
for some $i$.
  (b) For any $w^*>1$, we have $p_g=1$ iff the Koll\'ar surface is birational
to a K3 surface. We classify this situation.
  (c) For $w^*>>0$, we have that the smooth minimal model $S$ of a generic
Koll\'ar surface is of general type with $K_{S}^2/e(S) \to 1$.


title:
Universality and unconventional enhancement of flux-flow resistivity in
  Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$

abstract:
  Measurements of the current-voltage characteristics were performed on
Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals with doping level $0.044 \leq x
\leq 0.1$. An unconventional increase in the flux-flow resistivity $\rho_{\rm
ff}$ with decreasing magnetic field was observed across this doping range. Such
an abnormal field dependence of flux-flow resistivity is in contrast with the
linear field dependence of $\rho_{\rm ff}$ in conventional type-II
superconductors, but is similar to the behavior recently observed in the
heavy-fermion superconductor CeCoIn$_5$. A significantly enhanced $\rho_{\rm
ff}$ was found for the x=0.06 single crystals, implying a strong
single-particle energy dissipation around the vortex cores. At different
temperatures and fields and for a given doping concentration, the normalized
$\rho_{\rm ff}$ scales with normalized field and temperature. The doping level
dependence of these parameters strongly suggests that the abnormal upturn
flux-flow resisitivity is likely related to the enhancement of spin
fluctuations around the vortex cores of the optimally doped samples.


title: Non-negatively curved 6-manifolds with almost maximal symmetry rank

abstract:
  We classify closed, simply-connected, non-negatively curved 6-manifolds of
almost maximal symmetry rank up to equivariant diffeomorphism.


title: Dynamic Network Reconstruction from Heterogeneous Datasets

abstract:
  Performing multiple experiments is common when learning internal mechanisms
of complex systems. These experiments can include perturbations to parameters
or external disturbances. A challenging problem is to efficiently incorporate
all collected data simultaneously to infer the underlying dynamic network. This
paper addresses the reconstruction of dynamic networks from heterogeneous
datasets under the assumption that underlying networks share the same Boolean
structure across all experiments. Parametric models for dynamical structure
functions are derived to describe causal interactions between measured
variables. Multiple datasets are integrated into one regression problem with
additional demands of group sparsity to assure network sparsity and structure
consistency. To acquire structured group sparsity, we propose a sampling-based
method, together with extended versions of l1 methods and sparse Bayesian
learning. The performance of the proposed methods is benchmarked in numerical
simulation. In summary, this paper presents efficient methods on network
reconstruction from multiple experiments, and reveals practical experience that
could guide applications.


title: Fuzzy $CP^2$ Space-Times

abstract:
  Four-dimensional manifolds with changing signature are obtained by taking the
large $N$ limit of fuzzy $CP^2$ solutions to a Lorentzian matrix model. The
regions of Lorentzian signature give toy models of closed universes which
exhibit cosmological singularities. These singularities are resolved at finite
$N$, as the underlying $CP^2$ solutions are expressed in terms of finite matrix
elements.


title: Packing Directed and Hamilton Cycles Online

abstract:
  Consider a directed analogue of the random graph process on $n$ vertices,
where the $n(n-1)$ edges are ordered uniformly at random and revealed one at a
time.
  It is known that w.h.p.\@ the first digraph in this process with both
in-degree and out-degree $\geq q$ has a $[q]$-edge-coloring with a Hamilton
cycle in each color. We show that this coloring can be constructed online,
where each edge must be irrevocably colored as soon as it appears. In a similar
fashion, for the \emph{undirected} random graph process, we present an online
$[n]$-edge-coloring algorithm which yields w.h.p.\@ $q$ disjoint rainbow
Hamilton cycles in the first graph of the process that contains $q$ disjoint
Hamilton cycles.


title: On the Minimum Chordal Completion Polytope

abstract:
  A graph is chordal if every cycle of length at least four contains a chord,
that is, an edge connecting two nonconsecutive vertices of the cycle. Several
classical applications in sparse linear systems, database management, computer
vision, and semidefinite programming can be reduced to finding the minimum
number of edges to add to a graph so that it becomes chordal, known as the
minimum chordal completion problem (MCCP). In this article we propose a new
formulation for the MCCP which does not rely on finding perfect elimination
orderings of the graph, as has been considered in previous work. We introduce
several families of facet-defining inequalities for cycle subgraphs and
investigate the underlying separation problems, showing that some key
inequalities are NP-Hard to separate. We also show general properties of the
proposed polyhedra, indicating certain conditions and methods through which
facets and inequalities associated with the polytope of a certain graph can be
adapted in order to become valid and eventually facet-defining for some of its
subgraphs or supergraphs. Numerical studies combining heuristic separation
methods based on a threshold rounding and lazy-constraint generation indicate
that our approach substantially outperforms existing methods for the MCCP,
solving many benchmark graphs to optimality for the first time.


title: On some probabilistic aspects of (generalized) dicyclic groups

abstract:
  In this paper we study probabilistic aspects such as subgroup commutativity
degree and cyclic subgroup commutativity degree of the (generalized) dicyclic
groups. We find explicit formulas for these concepts and we provide another
example of a class of groups whose (cyclic) subgroup commutativity degree
vanishes asymptotically.


title: Numerical Analysis of Discretized ${\cal N}=(2,2)$ SYM on Polyhedra

abstract:
  We perform a numerical simulation of the two-dimensional ${\cal N}=(2,2)$
supersymmetric Yang-Mills (SYM) theory on the discretized curved space. The
$U(1)_{A}$ anomaly of the continuum theory is maintained also in the
discretized theory as an unbalance of the number of the fermions. In the
process, we propose a new phase-quenched approximation, which we call the
"anomaly-phase-quenched (APQ) method", to make the partition function and
observables well-defined by $U(1)_{A}$ phase cancellation. By adopting APQ
method, we estimate the Ward-Takahashi identity for exact SUSY on lattice and
clarify contribution of the pseudo zero-modes to the pfaffian phase.


title:
The landscape of $W^{\pm}$ and $Z$ bosons produced in $pp$ collisions up
  to LHC energies

abstract:
  We consider a selection of recent experimental results on electroweak
$W^{\pm},\,Z$ gauge boson production in $pp$ collisions at BNL RHIC and CERN
LHC energies in comparison to prediction of perturbative QCD calculations based
on different sets of NLO parton distribution functions including the
statistical PDF model known from fits to the DIS data. We show that the current
statistical PDF parameterisation (fitted to the DIS data only) underestimates
the LHC data on $W^{\pm},\,Z$ gauge boson production cross sections at the NLO
by about 20\%. This suggests that there is a need to refit the parameters of
the statistical PDF including the latest LHC data.


title:
Exceptional magneto-electric coupling and spontaneous electric
  polarization in anti-ferromagnet Co4Nb2O9

abstract:
  Synthesis and extensive structural, pyroelectric, magnetic, dielectric and
magneto-electric characterizations are reported for polycrystalline Co4Nb2O9
towards unraveling the multiferroic state especially in reference to the
magnetic spin flop transition. Magnetic measurements confirm the Co4Nb2O9
becomes antiferromagnetic (AFM) at around 28 K but no clear evidence for
spin-flop effect was found. Associated with the magnetic phase transition, a
sharp peak in pyroelectric current indicates the appearance of the strong
magneto-electric coupling below Neel temperature (TN) with a large coupling
constant upto 17.8 uC/m^2T. Using temperature oscillation technique, we
establish Co4Nb2O9 to be a genuine multiferroic with spontaneous electric
polarization in the anti-ferromagnetic state.


title:
Non-Fermi liquid Superconductivity: Eliashberg versus the
  Renormalization Group

abstract:
  We address the problem of superconductivity for non-Fermi liquids using two
commonly adopted, yet apparently distinct methods: 1) the renormalization group
(RG) and 2) Eliashberg theory. The extent to which both methods yield
consistent solutions for the low energy behavior of quantum metals has remained
unclear. We show that the perturbative RG beta function for the 4-Fermi
coupling can be explicitly derived from the linearized Eliashberg equations,
under the assumption that quantum corrections are approximately local across
energy scales. We apply our analysis to the test case of phonon mediated
superconductivity and show the consistency of both the Eliashberg and RG
treatments. We next study superconductivity near a class of quantum critical
points and find a transition between superconductivity and a "naked" metallic
quantum critical point with finite, critical BCS couplings. We speculate on the
applications of our theory to the phenomenology of unconventional metals.

categories: cond-mat.str-el cond-mat.supr-con hep-ph hep-th