title: From dynamical scaling to local scale-invariance: a tutorial

abstract:
  Dynamical scaling arises naturally in various many-body systems far from
equilibrium. After a short historical overview, the elements of possible
extensions of dynamical scaling to a local scale-invariance will be introduced.
Schr\"odinger-invariance, the most simple example of local scale-invariance,
will be introduced as a dynamical symmetry in the Edwards-Wilkinson
universality class of interface growth. The Lie algebra construction, its
representations and the Bargman superselection rules will be combined with
non-equilibrium Janssen-de Dominicis field-theory to produce explicit
predictions for responses and correlators, which can be compared to the results
of explicit model studies.
  At the next level, the study of non-stationary states requires to go over,
from Schr\"odinger-invariance, to ageing-invariance. The ageing algebra admits
new representations, which acts as dynamical symmetries on more general
equations, and imply that each non-equilibrium scaling operator is
characterised by two distinct, independent scaling dimensions. Tests of
ageing-invariance are described, in the Glauber-Ising and spherical models of a
phase-ordering ferromagnet and the Arcetri model of interface growth.

categories: cond-mat.stat-mech hep-th math-ph math.MP


title: Decay of correlations and laws of rare events for transitive random maps

abstract:
  We show that a uniformly continuous random perturbation of a transitive map
defines an aperiodic Harris chain which also satisfies Doeblin's condition. As
a result, we get exponential decay of correlations for suitable random
perturbations of such systems. We also prove that, for transitive maps, the
limiting distribution for Extreme Value Laws (EVLs) and Hitting/Return Time
Statistics (HTS/RTS) is standard exponential. Moreover, we show that the Rare
Event Point Process (REPP) converges in distribution to a standard Poisson
process.


title: Holographic black hole engineering at finite baryon chemical potential

abstract:
  This is a contribution for the Proceedings of the Conference Hot Quarks 2016,
held at South Padre Island, Texas, USA, 12-17 September 2016. I briefly review
some thermodynamic and baryon transport results obtained from a bottom-up
Einstein-Maxwell-Dilaton holographic model engineered to describe the physics
of the quark-gluon plasma at finite temperature and baryon density. The results
for the equation of state, baryon susceptibilities, and the curvature of the
crossover band are in quantitative agreement with the corresponding lattice QCD
results with $2+1$ flavors and physical quark masses. Baryon diffusion is
predicted to be suppressed by increasing the baryon chemical potential.


title:
Production of the Doubly Heavy Baryons, $B_c$ Meson and the All-charm
  Tetraquark at AFTER@LHC with Double Intrinsic Heavy Mechanism

abstract:
  In the paper we discuss contribution of the doubly intrinsic heavy mechanism
into the production of $B_c$ meson, the doubly heavy baryons and the all-charm
tetraquark at a future fixed-target experiment at the LHC (AFTER@LHC). The
production cross sections and the mean values of Feynman-x for the finale
states are presented.


title: Criterion for Single Photon Sources

abstract:
  We propose a criterion to classify and compare sources of single photons: the
$p$-norm of their $k$th-order photon correlations. While ideally one should use
the uniform norm with $p\rightarrow\infty$, in practice, the 3-norm already
allows a meaningful comparison and shows the serious limitations of the usual
criterion based on the second order correlation $g^{(2)}$ only. We apply this
new criterion to a large family of popular single photon sources and show that
some of them do not, in fact, qualify for this function. The best sources from
our selections consist of a cascade of two-level systems, improving on the
otherwise standard low-power resonant excitation of a single two-level system.


title:
Puzzles in modern biology. III. Two kinds of causality in age-related
  disease

abstract:
  The two primary causal dimensions of age-related disease are rate and
function. Change in rate of disease development shifts the age of onset. Change
in physiological function provides necessary steps in disease progression. A
causal factor may alter the rate of physiological change, but that causal
factor itself may have no direct physiological role. Alternatively, a causal
factor may provide a necessary physiological function, but that causal factor
itself may not alter the rate of disease onset. The rate-function duality
provides the basis for solving puzzles of age-related disease. Causal factors
of cancer illustrate the duality between rate processes of discovery, such as
somatic mutation, and necessary physiological functions, such as invasive
penetration across tissue barriers. Examples from cancer suggest general
principles of age-related disease.


title:
Puzzles in modern biology. IV. Neurodegeneration, localized origin and
  widespread decay

abstract:
  The motor neuron disease amyotrophic lateral sclerosis (ALS) typically begins
with localized muscle weakness. Progressive, widespread paralysis often follows
over a few years. Does the disease begin with local changes in a small piece of
neural tissue and then spread? Or does neural decay happen independently across
diverse spatial locations? The distinction matters, because local initiation
may arise by local changes in a tissue microenvironment, by somatic mutation,
or by various epigenetic or regulatory fluctuations in a few cells. A local
trigger must be coupled with a mechanism for spread. By contrast, independent
decay across spatial locations cannot begin by a local change, but must depend
on some global predisposition or spatially distributed change that leads to
approximately synchronous decay. This article outlines the conceptual frame by
which one contrasts local triggers and spread versus parallel spatially
distributed decay. Various neurodegenerative diseases differ in their
mechanistic details, but all can usefully be understood as falling along a
continuum of interacting local and global processes. Cancer provides an example
of disease progression by local triggers and spatial spread, setting a
conceptual basis for clarifying puzzles in neurodegeneration. Heart disease
also has crucial interactions between global processes, such as circulating
lipid levels, and local processes in the development of atherosclerotic
plaques. The distinction between local and global processes helps to understand
these various age-related diseases.


title: Design and Implementation of an Antenna Model for the Cooja simulator

abstract:
  COOJA is a network simulator developed for wireless sensor networks. It can
be used for high-level algorithm development as well as low-level device driver
implementations for accurate simulation of wireless sensor networks before
deployment. However, in a simulation Cooja assumes that the nodes are only
equipped with omnidirectional antennas. There is currently no support for
directional antennas. Due to the growing interest in the use of directional or
smart antennas in wireless sensor networks, a model that can support
directional antennas is essential for the realistic simulations of protocols
relying on directional communication. This paper presents work on extending
COOJA with a directional antenna model.


title:
Sizes of spaces of triangulations of 4-manifolds and balanced
  presentations of the trivial group

abstract:
  Let $M$ be any compact four-dimensional PL-manifold with or without boundary
(e.g. the four-dimensional sphere or ball). Consider the space $T(M)$ of all
simplicial isomorphism classes of triangulations of $M$ endowed with the metric
defined as the minimal number of bistellar transformations required to
transform one of two considered triangulations into the other. Our main result
is the existence of an absolute constant $C>1$ such that for every $m$ and all
sufficiently large $N$ there exist more than $C^N$ triangulations of $M$ with
at most $N$ simplices such that pairwise distances between them are greater
than $2^{2^{\ldots^{2^N}}}$ ($m$ times).
  This result follows from a similar result for the space of all balanced
presentations of the trivial group. ("Balanced" means that the number of
generators equals to the number of relations). This space is endowed with the
metric defined as the minimal number of Tietze transformations between finite
presentations. We prove a similar exponential lower bound for the number of
balanced presentations of length $\leq N$ with four generators that are
pairwise $2^{2^{\ldots^{2^N}}}$-far from each other. If one does not fix the
number of generators, then we establish a super-exponential lower bound
$N^{const\ N}$ for the number of balanced presentations of length $\leq N$ that
are $2^{2^{\ldots^{2^N}}}$-far from each other.


title: Explicit linear kernels for packing problems

abstract:
  During the last years, several algorithmic meta-theorems have appeared
(Bodlaender et al. [FOCS 2009], Fomin et al. [SODA 2010], Kim et al. [ICALP
2013]) guaranteeing the existence of linear kernels on sparse graphs for
problems satisfying some generic conditions. The drawback of such general
results is that it is usually not clear how to derive from them constructive
kernels with reasonably low explicit constants. To fill this gap, we recently
presented [STACS 2014] a framework to obtain explicit linear kernels for some
families of problems whose solutions can be certified by a subset of vertices.
In this article we enhance our framework to deal with packing problems, that
is, problems whose solutions can be certified by collections of subgraphs of
the input graph satisfying certain properties. ${\mathcal F}$-Packing is a
typical example: for a family ${\mathcal F}$ of connected graphs that we assume
to contain at least one planar graph, the task is to decide whether a graph $G$
contains $k$ vertex-disjoint subgraphs such that each of them contains a graph
in ${\mathcal F}$ as a minor. We provide explicit linear kernels on sparse
graphs for the following two orthogonal generalizations of ${\mathcal
F}$-Packing: for an integer $\ell \geq 1$, one aims at finding either
minor-models that are pairwise at distance at least $\ell$ in $G$
($\ell$-${\mathcal F}$-Packing), or such that each vertex in $G$ belongs to at
most $\ell$ minors-models (${\mathcal F}$-Packing with $\ell$-Membership).
Finally, we also provide linear kernels for the versions of these problems
where one wants to pack subgraphs instead of minors.


title:
Weak solutions of the Shigesaka-Kawasaki-Teramoto equations and their
  attractors

abstract:
  We derive the global existence of weak solutions of the
Shigesada-Kawasaki-Teramoto systems in space dimension less or equal to 4 with
a rather general condition on the coefficients. The existence is established
using finite differences in time with truncations and an argument of
Stampachia's maximum principle to show the positivity of the solutions. We
derive also the existence of a weak global attractor.


title: General degeneracy in density functional perturbation theory

abstract:
  Degenerate perturbation theory from quantum mechanics is inadequate in
density functional theory (DFT) because of nonlinearity in the Kohn-Sham
potential. Herein, we develop the fully general perturbation theory for
open-shell, degenerate systems in Kohn-Sham DFT, without assuming the presence
of symmetry or equal occupation of degenerate orbitals. To demonstrate the
resulting methodology, we apply it to the iron atom in the central field
approximation, perturbed by an electric quadrupole. This system was chosen
because it displays both symmetry required degeneracy, between the five
3\textit{d} orbitals, as well as accidental degeneracy, between the 3\textit{d}
and 4\textit{s} orbitals. The quadrupole potential couples the degenerate
3\textit{d} and 4\textit{s} states, serving as an example of the most general
perturbation.


title: Large-Scale Cosmic-Ray Anisotropy as a Probe of Interstellar Turbulence

abstract:
  We calculate the large-scale cosmic-ray (CR) anisotropies predicted for a
range of Goldreich-Sridhar (GS) and isotropic models of interstellar
turbulence, and compare them with IceTop data. In general, the predicted CR
anisotropy is not a pure dipole; the cold spots reported at 400 TeV and 2 PeV
are consistent with a GS model that contains a smooth deficit of
parallel-propagating waves and a broad resonance function, though some other
possibilities cannot, as yet, be ruled out. In particular, isotropic fast
magnetosonic wave turbulence can match the observations at high energy, but
cannot accommodate an energy dependence in the shape of the CR anisotropy. Our
findings suggest that improved data on the large-scale CR anisotropy could
provide a valuable probe of the properties - notably the power-spectrum - of
the interstellar turbulence within a few tens of parsecs from Earth.


title: "Twisted" black holes are unphysical

abstract:
  So-called "twisted" black holes have recently been proposed by Zhang
(1609.09721 [gr-qc]), and further considered by Chen and Jing (1610.00886
[gr-qc]), and more recently by Ong (1610.05757 [gr-qc]). While these spacetimes
are certainly Ricci-flat, and so mathematically satisfy the vacuum Einstein
equations, they are also merely minor variants on Taub--NUT spacetimes.
Consequently they exhibit several unphysical features that make them quite
unreasonable as realistic astrophysical objects. Specifically, these "twisted"
black holes are not (globally) asymptotically flat. Furthermore, they contain
closed timelike curves that are not hidden behind any event horizon --- the
most obvious of these closed timelike curves are small azimuthal circles around
the rotation axis, but the effect is more general. The entire region outside
the horizon is infested with closed timelike curves.


title:
POI: Multiple Object Tracking with High Performance Detection and
  Appearance Feature

abstract:
  Detection and learning based appearance feature play the central role in data
association based multiple object tracking (MOT), but most recent MOT works
usually ignore them and only focus on the hand-crafted feature and association
algorithms. In this paper, we explore the high-performance detection and deep
learning based appearance feature, and show that they lead to significantly
better MOT results in both online and offline setting. We make our detection
and appearance feature publicly available. In the following part, we first
summarize the detection and appearance feature, and then introduce our tracker
named Person of Interest (POI), which has both online and offline version.


title:
Langmuir wave filamentation in the kinetic regime. I. Filamentation
  instability of Bernstein-Greene-Kruskal modes in multidimensional Vlasov
  simulations

abstract:
  A nonlinear Langmuir wave in the kinetic regime $k\lambda_D\gtrsim0.2$ may
have a filamentation instability, where $k$ is the wavenumber and $\lambda_D$
is the Debye length. The nonlinear stage of that instability develops into the
filamentation of Langmuir waves which in turn leads to the saturation of the
stimulated Raman scattering in laser-plasma interaction experiments. Here we
study the linear stage of the filamentation instability of the particular
family \cite{RoseRussellPOP2001} of Bernstein-Greene-Kruskal (BGK) modes
\cite{BernsteinGreeneKruskal1957} that is a bifurcation of the linear Langmuir
wave. Performing direct $2+2D$ Vlasov-Poisson simulations of collisionless
plasma we find the growth rates of oblique modes of the electric field as a
function of BGK's amplitude, wavenumber and the angle of the oblique mode's
wavevector relative to the BGK's wavevector. Simulation results are compared to
theoretical predictions.


title: Fundamental Limits on Throughput Capacity in Information-Centric Network

abstract:
  Wireless information-centric networks consider storage as one of the network
primitives, and propose to cache data within the network in order to improve
latency and reduce bandwidth consumption. We study the throughput capacity and
latency in an information-centric network when the data cached in each node has
a limited lifetime. The results show that with some fixed request and cache
expiration rates, the order of the data access time does not change with
network growth, and the maximum throughput order is not changing with the
network growth in grid networks, and is inversely proportional to the number of
nodes in one cell in random networks. Comparing these values with the
corresponding throughput and latency with no cache capability (throughput
inversely proportional to the network size, and latency of order $\sqrt{n}$ and
the inverse of the transmission range in grid and random networks,
respectively), we can actually quantify the asymptotic advantage of caching.
Moreover, we compare these scaling laws for different content discovery
mechanisms and illustrate that not much gain is lost when a simple path search
is used.


title:
The complementarity relations of quantum coherence in quantum
  information processing

abstract:
  We establish two complementarity relations for the relative entropy of
coherence in quantum information processing, i.e., quantum dense coding and
teleportation. We first give an uncertaintylike expression relating local
quantum coherence to the capacity of optimal dense coding for bipartite system.
The relation can also be applied to the case of dense coding by using unital
memoryless noisy quantum channels. Further, the relation between local quantum
coherence and teleportation fidelity for two-qubit system is given.


title:
Honey Onions: a Framework for Characterizing and Identifying Misbehaving
  Tor HSDirs

abstract:
  In the last decade, Tor proved to be a very successful and widely popular
system to protect users' anonymity. However, Tor remains a practical system
with a variety of limitations, some of which were indeed exploited in the
recent past. In particular, Tor's security relies on the fact that a
substantial number of its nodes do not misbehave. In this work we introduce,
the concept of honey onions, a framework to detect misbehaving Tor relays with
HSDir capability. This allows to obtain lower bounds on misbehavior among
relays. We propose algorithms to both estimate the number of snooping HSDirs
and identify the most likely snoopers. Our experimental results indicate that
during the period of the study (72 days) at least 110 such nodes were snooping
information about hidden services they host. We reveal that more than half of
them were hosted on cloud infrastructure and delayed the use of the learned
information to prevent easy traceback.


title:
Search for Pauli Exclusion Principle Violating Atomic Transitions and
  Electron Decay with a P-type Point Contact Germanium Detector

abstract:
  A search for Pauli-exclusion-principle-violating K-alpha electron transitions
was performed using 89.5 kg-d of data collected with a p-type point contact
high-purity germanium detector operated at the Kimballton Underground Research
Facility. A lower limit on the transition lifetime of 5.8x10^30 seconds at 90%
C.L. was set by looking for a peak at 10.6 keV resulting from the x-ray and
Auger electrons present following the transition. A similar analysis was done
to look for the decay of atomic K-shell electrons into neutrinos, resulting in
a lower limit of 6.8x10^30 seconds at 90 C.L. It is estimated that the MAJORANA
DEMONSTRATOR, a 44 kg array of p-type point contact detectors that will search
for the neutrinoless double-beta decay of 76-Ge, could improve upon these
exclusion limits by an order of magnitude after three years of operation.


title: Coupling of Damped and Growing Modes in Unstable Shear Flow

abstract:
  Analysis of the saturation of the Kelvin-Helmholtz (KH) instability is
undertaken to determine the extent to which the conjugate linearly stable mode
plays a role. For a piecewise-continuous mean flow profile with constant shear
in a fixed layer, it is shown that the stable mode is nonlinearly excited,
providing an injection-scale sink of the fluctuation energy similar to what has
been found for gyroradius-scale drift-wave turbulence. Quantitative evaluation
of the contribution of the stable mode to the energy balance at the onset of
saturation shows that nonlinear energy transfer to the stable mode is as
significant as energy transfer to small scales in balancing energy injected
into the spectrum by the instability. The effect of the stable mode on momentum
transport is quantified by expressing the Reynolds stress in terms of stable
and unstable mode amplitudes at saturation, from which it is found that the
stable mode can produce a sizable reduction in the momentum flux.


title:
Real-Space Renormalization Group for Quantum Gravity I: Significance of
  terms linear and quadratic in curvature

abstract:
  Real-Space renormalization group techniques are developed for tackling large
curvature fluctuations in quantum gravity. Within cells of invariant volume
$a^4$, only certain types of fluctuations are allowed. Normal coordinates are
used to avoid redundancy of the degrees of freedom. The relevant integration
measure is read off from the metric on metrics. All fluctuations in a group of
cells are averaged over to get an effective action for the larger cell. In this
paper the simplest type of fluctuations are kept. The measure is simply an
integration over independent components of the curvature tensor at the center
of each cell. Terms of higher order in $a$ are required for convergence in case
of Einstein-Hilbert action. With only next order (in $a$) contribution to the
action, there is no renormalization of Newton's or cosmological constants. The
`massless Gaussian surface' in the renormalization group space is given by
actions that have linear and quadratic terms in curvature and determines the
evolution of coupling constants away from it. Our techniques allow for
systematic improvements.


title: Contagious sets in a degree-proportional bootstrap percolation process

abstract:
  We study the following bootstrap percolation process: given a connected graph
$G$, a constant $\rho \in [0, 1]$ and an initial set $A \subseteq V(G)$ of
\emph{infected} vertices, at each step a vertex~$v$ becomes infected if at
least a $\rho$-proportion of its neighbours are already infected (once
infected, a vertex remains infected forever). Our focus is on the size
$h_\rho(G)$ of a smallest initial set which is \emph{contagious}, meaning that
this process results in the infection of every vertex of $G$.
  Our main result states that every connected graph $G$ on $n$ vertices has
$h_\rho(G) < 2\rho n$ or $h_\rho(G) = 1$ (note that allowing the latter
possibility is necessary because of the case $\rho\leq\tfrac{1}{2n}$, as every
contagious set has size at least one). This is the best-possible bound of this
form, and improves on previous results of Chang and Lyuu and of Gentner and
Rautenbach. We also provide a stronger bound for graphs of girth at least five
and sufficiently small $\rho$, which is asymptotically best-possible.


title:
A global optimization algorithm for sparse mixed membership matrix
  factorization

abstract:
  Mixed membership factorization is a popular approach for analyzing data sets
that have within-sample heterogeneity. In recent years, several algorithms have
been developed for mixed membership matrix factorization, but they only
guarantee estimates from a local optimum. Here, we derive a global optimization
(GOP) algorithm that provides a guaranteed $\epsilon$-global optimum for a
sparse mixed membership matrix factorization problem. We test the algorithm on
simulated data and find the algorithm always bounds the global optimum across
random initializations and explores multiple modes efficiently.


title:
Density of states and dynamical crossover in a dense fluid revealed by
  exponential mode analysis of the velocity autocorrelation function

abstract:
  Extending a previous study of the velocity autocorrelation function (VAF) in
a simulated Lennard-Jones fluid to cover higher-density and lower-temperature
states, we show that the recently demonstrated multiexponential expansion
allows for a full account and understanding of the dynamical processes
encompassed by a fundamental quantity as the VAF. In particular, besides
obtaining evidence of a persisting long-time tail, we assign specific and
unambiguous physical meanings to groups of exponential modes related to the
longitudinal and transverse collective dynamics, respectively. We have made
this possible by consistently introducing the interpretation of the VAF
frequency spectrum as a global density of states in fluids, generalizing a
solid-state concept, and by giving to specific spectral components, obtained
via the VAF exponential expansion, the corresponding meaning of partial
densities of states relative to specific dynamical processes. The clear
identification of a high-frequency oscillation of the VAF with the near-top
excitation frequency in the dispersion curve of acoustic waves is a neat
example of the power of the method. As for the transverse mode contribution,
its analysis turns out to be particularly important, because the
multiexponential expansion reveals a transition marking the onset of
propagating excitations when the density is increased above a threshold value.
While this finding agrees with recent literature debating the issue of
dynamical crossover boundaries, such as the one identified with the Frenkel
line, we can add detailed information on the modes involved in this specific
process in the domains of both time and frequency. This will help obtain a
still missing full account of transverse dynamics, in its nonpropagating and
propagating aspects which are linked by dynamical transitions depending on both
the thermodynamic states and the excitation wavevectors.


title: Arithmetic Kleinian groups generated by elements of finite order

abstract:
  We show that up to commensurability there are only finitely many cocompact
arithmetic Kleinian groups generated by rotations. This implies, in particular,
that there exist only finitely many conjugacy classes of cocompact two
generated arithmetic Kleinian groups. The proof of the main result is based on
a generalized Gromov--Guth inequality and bounds for the hyperbolic and tube
volumes of the quotient orbifolds.


title: Reflective anisotropic hyperbolic lattices of rank $4$

abstract:
  A hyperbolic lattice is called \textit{$1.2$-reflective} if the subgroup of
its automorphism group generated by all $1$- and $2$-reflections is of finite
index. The main result of this article is a complete classification of
$1.2$-reflective maximal anisotropic lattices of rank $4$.


title: Robust Stackelberg controllability for a parabolic equation

abstract:
  The aim of this paper is to perform a Stackelberg strategy to control
parabolic equations. We have one control, \textit{the leader}, that is
responsible for a null controllability property; additionally, we have a
control \textit{the follower} that solves a robust control objective. That
means, that we seek for a saddle point of a cost functional. In this way, the
follower control is not sensitive to a broad class of external disturbances. As
far as we know, the idea of combining robustness with a Stackelberg strategy is
new in literature


title:
Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active
  Region Cores. II. Nanoflare Trains

abstract:
  Despite its prediction over two decades ago, the detection of faint,
high-temperature ("hot") emission due to nanoflare heating in non-flaring
active region cores has proved challenging. Using an efficient two-fluid
hydrodynamic model, this paper investigates the properties of the emission
expected from repeating nanoflares (a nanoflare train) of varying frequency as
well as the separate heating of electrons and ions. If the emission measure
distribution ($\mathrm{EM}(T)$) peaks at $T = T_m$, we find that
$\mathrm{EM}(T_m)$ is independent of details of the nanoflare train, and
$\mathrm{EM}(T)$ above and below $T_m$ reflects different aspects of the
heating. Below $T_m$ the main influence is the relationship of the waiting time
between successive nanoflares to the nanoflare energy. Above $T_m$ power-law
nanoflare distributions lead to an extensive plasma population not present in a
monoenergetic train. Furthermore, in some cases characteristic features are
present in $\mathrm{EM}(T)$. Such details may be detectable given adequate
spectral resolution and a good knowledge of the relevant atomic physics. In the
absence of such resolution we propose some metrics that can be used to infer
the presence of "hot" plasma.


title: Neural Networks for Modeling and Control of Particle Accelerators

abstract:
  We describe some of the challenges of particle accelerator control, highlight
recent advances in neural network techniques, discuss some promising avenues
for incorporating neural networks into particle accelerator control systems,
and describe a neural network-based control system that is being developed for
resonance control of an RF electron gun at the Fermilab Accelerator Science and
Technology (FAST) facility, including initial experimental results from a
benchmark controller.


title:
Impact of Intermediate Sites on Bulk Diffusion Barriers: Mg
  Intercalation in Mg$_2$Mo$_3$O$_8$

abstract:
  The ongoing search for high voltage positive electrode materials for Mg
batteries has been primarily hampered by poor Mg mobility in bulk oxide
frameworks. Motivated by the presence of Mo$_3$ clusters that can facilitate
charge redistribution and the presence of Mg in a non-preferred (tetrahedral)
coordination environment, we have investigated the Mg (de)intercalation
behavior in layered-Mg$_2$Mo$_3$O$_8$, a potential positive electrode. While no
electrochemical activity is observed, chemical demagnesiation of
Mg$_2$Mo$_3$O$_8$ is successful but leads to amorphization. Subsequent
first-principles calculations predict a strong thermodynamic driving force for
structure decomposition at low Mg concentrations and high activation barriers
for bulk Mg diffusion, in agreement with experimental observations. Further
analysis of the Mg diffusion pathway reveals an O--Mg--O dumbbell intermediate
site that creates a high Mg$^{2+}$ migration barrier, indicating the influence
of transition states on setting the magnitude of migration barriers.


title:
Near Threshold Effects on Recombination and Vibrational Relaxation in
  Efimov Systems

abstract:
  We investigate the energy dependence of inelastic processes in systems which
possess Efimov states. We consider the three-body recombination rate $K_3$
where three free atoms interact to produce an atom--dimer pair, and the
relaxation rate $K_{\rm rel}$ where an atom quenches a weakly bound state of a
dimer near an Efimov resonance to more deeply bound levels. Using a model
capturing the key features of the Efimov problem, we identify new energy
regimes for $K_3$, namely the NTR (Near Threshold Resonance) regime behavior
$E^{-2}$ for negative scattering lengths and the NTS (Near Threshold
Suppression) regime behavior $E^2$ for positive scattering lengths. We also
confirm a previously found oscillatory behavior of $K_3$ at higher energy $E$.
Finally, we find that $K_{\rm rel}$ behaves as $E^{-1}$ in the NTR regime.


title: Streamflow forecasting using functional regression

abstract:
  Streamflow, as a natural phenomenon, is continuous in time and so are the
meteorological variables which influence its variability. In practice, it can
be of interest to forecast the whole flow curve instead of points (daily or
hourly). To this end, this paper introduces the functional linear models and
adapts it to hydrological forecasting. More precisely, functional linear models
are regression models based on curves instead of single values. They allow to
consider the whole process instead of a limited number of time points or
features. We apply these models to analyse the flow volume and the whole
streamflow curve during a given period by using precipitations curves. The
functional model is shown to lead to encouraging results. The potential of
functional linear models to detect special features that would have been hard
to see otherwise is pointed out. The functional model is also compared to the
artificial neural network approach and the advantages and disadvantages of both
models are discussed. Finally, future research directions involving the
functional model in hydrology are presented.


title:
Measuring neutron star tidal deformability with Advanced LIGO: a
  Bayesian analysis of neutron star - black hole binary observations

abstract:
  The discovery of gravitational waves (GW) by Advanced LIGO has ushered us
into an era of observational GW astrophysics. Compact binaries remain the
primary target sources for LIGO, of which neutron star-black hole (NSBH)
binaries form an important subset. GWs from NSBH sources carry signatures of
(a) the tidal distortion of the neutron star by its companion black hole during
inspiral, and (b) its potential tidal disruption near merger. In this paper, we
present a Bayesian study of the measurability of neutron star tidal
deformability $\Lambda_\mathrm{NS}\propto (R/M)^{5}$ using observation(s) of
inspiral-merger GW signals from disruptive NSBH coalescences, taking into
account the crucial effect of black hole spins. First, we find that if
non-tidal templates are used to estimate source parameters for an NSBH signal,
the bias introduced in the estimation of non-tidal physical parameters will
only be significant for loud signals with signal-to-noise ratios $> 30$. For
similarly loud signals, we also find that we can begin to put interesting
constraints on $\Lambda_\mathrm{NS}$ (factor of 1-2) with individual
observations. Next, we study how a population of realistic NSBH detections will
improve our measurement of neutron star tidal deformability. For astrophysical
populations of $disruptive$ NSBH mergers, we find 20-35 events to be sufficient
to constrain $\Lambda_\mathrm{NS}$ within $\pm 25-50\%$, depending on the
chosen equation of state. In this we also assume that LIGO will detect black
holes with masses within the astrophysical $mass$-$gap$. If the mass-gap
remains preserved in NSBHs detected by LIGO, we estimate that $25\%$
$additional$ detections will furnish comparable tidal measurement accuracy. In
both cases, we find that the loudest 5-10 events to provide most of the tidal
information, thereby facilitating targeted follow-ups of NSBHs in the upcoming
LIGO-Virgo runs.


title: Black hole microstates from branes at angle

abstract:
  We derive the leading g_s perturbation of the SUGRA fields generated by a
supersymmetric configuration of respectively 1, 2 or 4 D3-branes intersecting
at an arbitrary angle via the computation of the string theory disk scattering
amplitude of one massless NSNS field interacting with open strings stretched
between the branes. The configuration with four branes is expected to be
relevant for black hole microstate counting in four dimensions.


title:
Event count distributions from renewal processes: fast computation of
  probabilities

abstract:
  Discrete distributions derived from renewal processes, ie distributions of
the number of events by some time t are beginning to be used in econometrics
and health sciences. A new fast method is presented for computation of the
probabilities for these distributions. We calculate the count probabilities by
repeatedly convolving the discretized distribution, and then correct them using
Richardson extrapolation. When just one probability is required, a second
algorithm is described, an adaptation of De Pril's method, in which the
computation time does not depend on the ordinality, so that even high-order
probabilities can be rapidly found. Any survival distribution can be used to
model the inter-arrival times, which gives a rich class of models with great
flexibility for modelling both underdispersed and overdispersed data. This work
could pave the way for the routine use of these distributions as an additional
tool for modelling event count data. An empirical example using fertility data
illustrates the use of the method and was fully implemented using an R package
Countr developed by the authors and available from the Comprehensive R Archive
Network.


title: Non-Abelian Ball-Chiu vertex for arbitrary Euclidean momenta

abstract:
  We determine the non-Abelian version of the four longitudinal form factors of
the quark-gluon vertex, using exact expressions derived from the Slavnov-Taylor
identity that this vertex satisfies. In addition to the quark and ghost
propagators, a key ingredient of the present approach is the quark-ghost
scattering kernel, which is computed within the one-loop dressed approximation.
The vertex form factors obtained from this procedure are evaluated for
arbitrary Euclidean momenta, and display features not captured by the
well-known Ball-Chiu vertex, deduced from the Abelian (ghost-free) Ward
identity. The potential phenomenological impact of these results is evaluated
through the study of special renormalization-point-independent combinations,
which quantify the strength of the interaction kernels appearing in the
standard quark gap and Bethe-Salpeter equations.


title:
Purely Singular Continuous Spectrum for Limit-Periodic CMV Operators
  with Applications to Quantum Walks

abstract:
  We show that a generic element of a space of limit-periodic CMV operators has
zero-measure Cantor spectrum. We also prove a Craig--Simon type theorem for the
density of states measure associated with a stochastic family of CMV matrices
and use our construction from the first part to prove that the Craig--Simon
result is optimal in general. We discuss applications of these results to a
quantum walk model where the coins are arranged according to a limit-periodic
sequence. The key ingredient in these results is a new formula which may be
viewed as a relationship between the density of states measure of a CMV matrix
and its Schur function.


title:
Streaming Normalization: Towards Simpler and More Biologically-plausible
  Normalizations for Online and Recurrent Learning

abstract:
  We systematically explored a spectrum of normalization algorithms related to
Batch Normalization (BN) and propose a generalized formulation that
simultaneously solves two major limitations of BN: (1) online learning and (2)
recurrent learning. Our proposal is simpler and more biologically-plausible.
Unlike previous approaches, our technique can be applied out of the box to all
learning scenarios (e.g., online learning, batch learning, fully-connected,
convolutional, feedforward, recurrent and mixed --- recurrent and
convolutional) and compare favorably with existing approaches. We also propose
Lp Normalization for normalizing by different orders of statistical moments. In
particular, L1 normalization is well-performing, simple to implement, fast to
compute, more biologically-plausible and thus ideal for GPU or hardware
implementations.


title: Finite Localities III

abstract: This third in the series establishes a category of finite localities.


title:
Compositional bisimulation metric reasoning with Probabilistic Process
  Calculi

abstract:
  We study which standard operators of probabilistic process calculi allow for
compositional reasoning with respect to bisimulation metric semantics. We argue
that uniform continuity (generalizing the earlier proposed property of
non-expansiveness) captures the essential nature of compositional reasoning and
allows now also to reason compositionally about recursive processes. We
characterize the distance between probabilistic processes composed by standard
process algebra operators. Combining these results, we demonstrate how
compositional reasoning about systems specified by continuous process algebra
operators allows for metric assume-guarantee like performance validation.


title: The many facets of the Fabry-Perot

abstract:
  We address the response, both in amplitude and intensity, of a Fabry-Perot
from a variety of viewpoints. These complementary pictures conspire to achieve
a comprehensive and consistent theory of the operation of this system.


title: Recovering the quantum formalism from physically realist axioms

abstract:
  We present a heuristic derivation of Born's rule and unitary transforms in
Quantum Mechanics, from a simple set of axioms built upon a physical
phenomenology of quantization. This approach naturally leads to the usual
quantum formalism, within a new realistic conceptual framework that is
discussed in details. Physically, the structure of Quantum Mechanics appears as
a result of the interplay between the quantized number of "modalities"
accessible to a quantum system, and the continuum of "contexts" that are
required to define these modalities. Mathematically, the Hilbert space
structure appears as a consequence of a specific "extra-contextuality" of
modalities, closely related to the hypothesis of Gleason's theorem, and
consistent with its conclusions.


title:
Imaging the Long Transport Lengths of Photo-generated Carriers in
  Oriented Perovskite Films

abstract:
  Organometal halide perovskite has emerged as a promising material for solar
cells and optoelectronics. Although the long diffusion length of
photo-generated carriers is believed to be a critical factor responsible for
the material's high efficiency in solar cells, a direct study of carrier
transport over long distances in organometal halide perovskites is still
lacking. We fabricated highly oriented crystalline CH$_3$NH$_3$PbI$_3$
(MAPbI$_3$) thin film lateral transport devices with long channel length (~ 120
$\mu$m). By performing spatially scanned photocurrent imaging measurements with
local illumination, we directly show that the perovskite films prepared here
have very long transport lengths for photo-generated carriers, with a minority
carrier (electron) diffusion length on the order of 10 $\mu$m. Our approach of
applying scanning photocurrent microscopy to organometal halide perovskites may
be further used to elucidate the carrier transport processes and vastly
different carrier diffusion lengths (~ 100 nm to 100 $\mu$m) in different types
of organometal halide perovskites.


title:
Sums of products of binomial coefficients mod 2 and run length
  transforms of sequences

abstract:
  We look at some properties of functions of binomial coefficients mod 2. In
particular, we derive a set of recurrence relations for sums of products of
binomial coefficients mod 2 and show that they result in sequences that are the
run length transforms of well known basic sequences. In particular, we obtain
formulas for the run length transform of the positive integers, Fibonacci
numbers, extended Lucas numbers and Narayana's cows sequence.


title:
Deep Chandra Observations of the Pulsar Wind Nebula Created by PSR
  B0355+54

abstract:
  We report on Chandra X-ray Observatory (CXO) observations of the pulsar wind
nebula (PWN) associated with PSR B0355+54 (eight observations with a 395 ks
total exposure, performed over an 8 month period). We investigated the spatial
and spectral properties of the emission coincident with the pulsar, compact
nebula (CN), and extended tail. We find that the CN morphology can be
interpreted in a way that suggests a small angle between the pulsar spin axis
and our line-of-sight, as inferred from the radio data. On larger scales,
emission from the 7' (2 pc) tail is clearly seen. We also found hints of two
faint extensions nearly orthogonal to the direction of the pulsar's proper
motion. The spectrum extracted at the pulsar position can be described with an
absorbed power-law + blackbody model. The nonthermal component can be
attributed to magnetospheric emission, while the thermal component can be
attributed to emission from either a hot spot (e.g., a polar cap) or the entire
neutron star surface. Surprisingly, the spectrum of the tail shows only a
slight hint of cooling with increasing distance from the pulsar. This implies
either a low magnetic field with fast flow speed, or particle re-acceleration
within the tail. We estimate physical properties of the PWN and compare the
morphologies of the CN and the extended tail with those of other bow shock PWNe
observed with long CXO exposures.


title: Lattice effects on nematic quantum criticality in metals

abstract:
  Theoretically, it is commonly held that in metals near a nematic quantum
critical point the electronic excitations become incoherent on the entire `hot'
Fermi surface, triggering non Fermi liquid behavior. However, such conclusions
are based on electron-only theories, ignoring a symmetry-allowed coupling
between the electronic nematic variable and a suitable crystalline lattice
strain. Here we show that including this coupling leads to entirely different
conclusions because the critical fluctuations are mostly cutoff by the
non-critical lattice shear modes. At sufficiently low temperatures the
thermodynamics remain Fermi liquid type, while, depending on the Fermi surface
geometry, either the entire Fermi surface stays cold, or at most there are hot
spots. In particular, our predictions are relevant for the iron-based
superconductors.


title: Limits on the storage of quantum information in a volume of space

abstract:
  We study the fundamental limits on the reliable storage of quantum
information in lattices of qubits by deriving tradeoff bounds for approximate
quantum error correcting codes. We introduce a notion of local approximate
correctability and code distance, and give a number of equivalent formulations
thereof, generalizing various exact error-correction criteria. Our tradeoff
bounds relate the number of physical qubits $n$, the number of encoded qubits
$k$, the code distance $d$, the accuracy parameter $\delta$ that quantifies how
well the erasure channel can be reversed, and the locality parameter $\ell$
that specifies the length scale at which the recovery operation can be done. In
a regime where the recovery is successful to accuracy $\epsilon$ that is
exponentially small in $\ell$, which is the case for perturbations of local
commuting projector codes, our bound reads $kd^{\frac{2}{D-1}} \le O\bigl(n
(\log n)^{\frac{2D}{D-1}} \bigr)$ for codes on $D$-dimensional lattices of
Euclidean metric. We also find that the code distance of any local approximate
code cannot exceed $O\bigl(\ell n^{(D-1)/D}\bigr)$ if $\delta \le O(\ell
n^{-1/D})$. As a corollary of our formulation of correctability in terms of
logical operator avoidance, we show that the code distance $d$ and the size
$\tilde d$ of a minimal region that can support all approximate logical
operators satisfies $\tilde d d^{\frac{1}{D-1}}\le O\bigl( n
\ell^{\frac{D}{D-1}} \bigr)$, where the logical operators are accurate up to
$O\bigl( ( n \delta / d )^{1/2}\bigr)$ in operator norm. Finally, we prove that
for two-dimensional systems if logical operators can be approximated by
operators supported on constant-width flexible strings, then the dimension of
the code space must be bounded. This supports one of the assumptions of
algebraic anyon theories, that there exist only finitely many anyon types.


title:
BPF-type Region-of-interest Reconstruction for Parallel Translational
  Computed Tomography

abstract:
  Recently, an ultra-low-cost linear scan based tomography architecture was
proposed by our team. Similar to linear tomosynthesis, the source and detector
are translated in opposite directions and the data acquisition system targets
on a region-of-interest (ROI) to acquire data for image reconstruction. This
kind of tomography architecture was named parallel translational computed
tomography (PTCT). In our previous studies, filtered backprojection (FBP)-type
algorithms were developed to reconstruct images from PTCT. However, the
reconstructed ROI images from truncated projections have severe truncation
artifacts. In this paper, we propose two backprojection filtering (BPF)-type
algorithms named MP-BPF and MZ-BPF to reconstruct ROI images from truncated
PTCT data. A weight function is constructed to deal with data redundancy for
multi-linear translations modes. Extensive numerical simulations are performed
to evaluate the proposed MP-BPF and MZ-BPF algorithms for PTCT in fan-beam
geometry. Qualitative and quantitative results demonstrate that the proposed
BPF-type algorithms can not only accurately reconstruct ROI images from
truncated projections but also provide high-quality images for the entire image
support in some circumstances.


title:
Mathematical Modeling of Electrolyte Flow Dynamic Patterns and
  Volumetric Flow Penetrations in the Flow Channel over Porous Electrode
  Layered System in Vanadium Flow Battery with Serpentine Flow Field Design

abstract:
  In this work, a two-dimensional mathematical model is developed to study the
flow patterns and volumetric flow penetrations in the flow channel over the
porous electrode layered system in vanadium flow battery with serpentine flow
field design. The flow distributions at the interface between the flow channel
and porous electrode are examined. It is found that the non-linear pressure
distributions can distinguish the interface flow distributions under the ideal
plug flow and ideal parabolic flow inlet boundary conditions. However, the
volumetric flow penetration within the porous electrode beneath the flow
channel through the integration of interface flow velocity reveals that this
value is identical under both ideal plug flow and ideal parabolic flow inlet
boundary conditions. The volumetric flow penetrations under the advection
effects of flow channel and landing/rib are estimated. The maximum current
density achieved in the flow battery can be predicted based on the 100% amount
of electrolyte flow reactant consumption through the porous electrode beneath
both flow channel and landing channel. The corresponding theoretical maximum
current densities achieved in vanadium flow battery with one and three layers
of SGL 10AA carbon paper electrode have reasonable agreement with experimental
results under a proper permeability.


title:
Enhancing the injection locking range of spin torque oscillators through
  mutual coupling

abstract:
  We investigate how the ability of the vortex oscillation mode of a
spin-torque nano-oscillator to lock to an external microwave signal is modified
when it is coupled to another oscillator. We show experimentally that mutual
electrical coupling can lead to locking range enhancements of a factor 1.64.
Furthermore, we analyze the evolution of the locking range as a function of the
coupling strength through experiments and numerical simulations. By uncovering
the mechanisms at stake in the locking range enhancement, our results will be
useful for designing spin-torque nano-oscillators arrays with high
sensitivities to external microwave stimuli.


title:
A Hybrid Solver of Size Modified Poisson-Boltzmann Equation by Domain
  Decomposition, Finite Element, and Finite Difference

abstract:
  The size-modified Poisson-Boltzmann equation (SMPBE) is one important variant
of the popular dielectric model, the Poisson-Boltzmann equation (PBE), to
reflect ionic size effects in the prediction of electrostatics for a
biomolecule in an ionic solvent. In this paper, a new SMPBE hybrid solver is
developed using a solution decomposition, the Schwartz's overlapped domain
decomposition, finite element, and finite difference. It is then programmed as
a software package in C, Fortran, and Python based on the state-of-the-art
finite element library DOLFIN from the FEniCS project. This software package is
well validated on a Born ball model with analytical solution and a dipole model
with a known physical properties. Numerical results on six proteins with
different net charges demonstrate its high performance. Finally, this new SMPBE
hybrid solver is shown to be numerically stable and convergent in the
calculation of electrostatic solvation free energy for 216 biomolecules and
binding free energy for a DNA-drug complex.


title:
M32 Analogs? A Population of Massive Ultra Compact Dwarf and Compact
  Elliptical Galaxies in intermediate redshift CLASH Clusters

abstract:
  We report the discovery of relatively massive, M32-like ultra compact dwarf
(UCD) and compact elliptical (CE) galaxy candidates in $0.2<z<0.6$ massive
galaxy clusters imaged by the Cluster Lensing And Supernova survey with {\it
Hubble} (CLASH) survey. Examining the nearly unresolved objects in the survey,
we identify a sample of compact objects concentrated around the cluster central
galaxies with colors similar to cluster red sequence galaxies. Their colors and
magnitudes suggest stellar masses around $10^9 \mathrm{M_{\odot}}$. More than
half of these galaxies have half-light radii smaller than 200 pc, falling into
the category of massive UCDs and CEs, with properties similar to M32. The
properties are consistent with a tidal stripping origin, but we cannot rule out
the possibility that they are early-formed compact objects trapped in massive
dark matter halos. The 17 CLASH clusters studied in this work on average
contain 2.7 of these objects in their central 0.3 Mpc and 0.6 in their central
50 kpc. Our study demonstrates the possibility of statistically characterizing
UCDs/CEs with a large set of uniform imaging survey data.


title: HI4PI: A full-sky HI survey based on EBHIS and GASS

abstract:
  Measurement of the Galactic neutral atomic hydrogen (HI) column density, NHI,
and brightness temperatures, Tb, is of high scientific value for a broad range
of astrophysical disciplines. In the past two decades, one of the most-used
legacy HI datasets has been the Leiden/Argentine/Bonn Survey (LAB). We release
the HI 4$\pi$ survey (HI4PI), an all-sky database of Galactic HI, which
supersedes the LAB survey. The HI4PI survey is based on data from the recently
completed first coverage of the Effelsberg-Bonn HI Survey (EBHIS) and from the
third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share
similar angular resolution and match well in sensitivity. Combined, they are
ideally suited to be a successor to LAB. The new HI4PI survey outperforms the
LAB in angular resolution (16.2', FWHM) and sensitivity (RMS: 43 mK). Moreover,
it has full spatial sampling and thus overcomes a major drawback of LAB, which
severely undersamples the sky. We publish all-sky column density maps of the
neutral atomic hydrogen in the Milky Way, along with full spectroscopic data,
in several map projections including HEALPix.


title: On the linearity of tracer bias around voids

abstract:
  The large-scale structure of the universe can only be observed via luminous
tracers of the dark matter. However, the clustering statistics of tracers are
biased and depend on various properties, such as their host-halo mass and
assembly history. On very large scales this tracer bias results in a constant
offset in the clustering amplitude, known as linear bias. Towards smaller
nonlinear scales, this is no longer the case and tracer bias becomes a
complicated function of scale and time. We focus on tracer bias centred on
cosmic voids, depressions of the density field that spatially dominate the
universe. We consider three types of tracers: galaxies, galaxy clusters and
AGN, extracted from the hydrodynamical simulation Magneticum Pathfinder. In
contrast to common clustering statistics that focus on auto-correlations of
tracers, we find that void-tracer cross-correlations are successfully described
by a linear-bias relation. The tracer-density profile of voids can thus be
related to their matter-density profile by a single number. We show that it
coincides with the linear tracer bias extracted from the large-scale
auto-correlation function and expectations from theory, if sufficiently large
voids are considered. For smaller voids we observe a shift towards higher
values. This has important consequences on cosmological parameter inference, as
the problem of unknown tracer bias is alleviated up to a constant number. The
smallest scales in existing datasets become accessible to simpler models,
providing numerous modes of the density field that have been disregarded so
far, but may help to further reduce statistical errors in constraining
cosmology.


title:
Magnetic field-Induced Nonlinear Optical Responses in Inversion
  Symmetric Dirac Semimetals

abstract:
  We show that, under the effect of an external magnetic field, a photogalvanic
effect and the generation of second harmonic wave can be induced in
inversion-symmetric and time reversal invariant Dirac semimetals. The mechanism
responsible of these non linear optical responses is the magnetochiral effect.
The origin of this magnetochiral effect is the band bending of the dispersion
relation in real Dirac semimetals. Some observable consequences of this
phenomenon are the appearance of a dc current on the surface of the system when
it is irradiated with linearly polarized light or a rotation of the
polarization plane of the reflected second harmonic wave.


title: On the existence of stationary Ricci solitons

abstract:
  Previously the DeTurck 'trick' has been used to render the stationary
Einstein's equation a well posed elliptic system that may be solved numerically
by geometric flow or directly. Whilst in the static case for pure gravity with
zero or negative cosmological constant there is a simple proof that solving the
modified "harmonic" Einstein's equation leads to a solution of the original
Einstein system - i.e. not a Ricci soliton - in the stationary case this
argument no longer works. Here we provide a new argument that extends the
static result to the case of stationary spacetimes that possess a "$t$-$\phi$"
reflection symmetry. Defining a "soliton charge" from the asymptotic behaviour
of the solution, we show that this quantity is always non-positive. Provided
asymptotic conditions are chosen such that this charge vanishes, then
stationary solitons cannot exist.


title: Tagging a mono-top signature in Natural SUSY

abstract:
  We study the feasibility of probing a region of Natural Supersymmetry where
the stop and higgsino masses are compressed. Although this region is most
effectively searched for in the mono-jet channel, this signature is present in
many other non-supersymmetric frameworks. Therefore, another channel that
carries orthogonal information is required to confirm the existence of the
light stop and higgsinos. We show that a supersymmetric version of the $t \bar
t H$ process, $pp \to t \tilde t_1 \tilde \chi^0_{1(2)}$, can have observably
large rate when both the stop and higgsinos are significantly light, and it
leads to a distinctive mono-top signature in the compressed mass region. We
demonstrate that the hadronic channel of the mono-top signature can effectively
discriminate the signal from backgrounds by tagging a hadronic top-jet. We show
that the hadronic channel of mono-top signature offers a significant
improvement over the leptonic channel and the sensitivity reaches $m_{\tilde
t_1} \simeq 420$ GeV at the 13 TeV LHC with 3 ab$^{-1}$ luminosity.


title:
Hubble Tarantula Treasury Project V. The star cluster Hodge 301: the old
  face of 30 Doradus

abstract:
  Based on color-magnitude diagrams (CMDs) from the Hubble Space Telescope
Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation
history (SFH) of Hodge~301, the oldest star cluster in the Tarantula Nebula.
The HTTP photometry extends faint enough to reach, for the first time, the
cluster pre-main sequence (PMS) turn-on, where the PMS joins the main sequence.
Using the location of this feature, along with synthetic CMDs generated with
the latest PARSEC models, we find that Hodge~301 is older than previously
thought, with an age between 26.5 and 31.5 Myr. From this age, we also estimate
that between 38 and 61 supernovae Type-II exploded in the region. The same age
is derived from the main sequence turn-off, whereas the age derived from the
post-main sequence stars is younger and between 20 and 25 Myr. Other relevant
parameters are a total stellar mass of $\approx 8800\,\pm 800$M$_{\odot}$ and
average reddening E(B$-$V) $\approx 0.22-0.24$ mag, with a differential
reddening $\delta$E(B$-$V)$\approx 0.04$ mag.


title: Scattering effect on entanglement propagation in RCFTs

abstract:
  In this paper we discuss the scattering effect on entanglement propagation in
RCFTs. In our setup, we consider the time evolution of excited states created
by the insertion of many local operators. Our results show that because of the
finiteness of quantum dimension, entanglement is not changed after the
scattering in RCFTs. In this mean, entanglement is conserved after the
scattering event in RCFTs, which reflects the integrability of the system. Our
results are also consistent with the free quasiparticle picture after the
global quenches.


title:
Bayesian analysis of spatial-dependent cosmic-ray propagation:
  astrophysical background of antiprotons and positrons

abstract:
  The AMS-02 experiment has reported a new measurement of the antiproton/proton
ratio in Galactic cosmic rays (CRs). In the energy range $E\sim\,$60-450 GeV,
this ratio is found to be remarkably constant. Using recent data on CR proton,
helium, and carbon fluxes, 10Be/9Be and B/C ratios, we have performed a global
Bayesian analysis based on a Markov-Chain Monte-Carlo sampling algorithm under
a "two halo model" of CR propagation. In this model, CRs are allowed to
experience a different type of diffusion when they propagate in the region
close of the Galactic disk. We found that the vertical extent of this region is
about 900 pc above and below the disk, and the corresponding diffusion
coefficient scales with energy as $D\sim\,E^{0.15}$, describing well the
observations on primary CR spectra, secondary/primary ratios and anisotropy.
Under this model we have carried out improved calculations of antiparticle
spectra arising from secondary CR production and their corresponding
uncertainties. We made use of Monte-Carlo generators and accelerator data to
assess the antiproton production cross-sections and their uncertainties. While
the positron excess requires the contribution of additional unknown sources, we
found that the new AMS-02 antiproton data are consistent, within the estimated
uncertainties, with our calculations based on secondary production.


title: {\Lambda} CDM is Consistent with SPARC Radial Acceleration Relation

abstract:
  Recent analysis \citep{McGaugh2016} of the SPARC galaxy sample found a
surprisingly tight relation between the radial acceleration inferred from the
rotation curves, and the acceleration due to the baryonic components of the
disc. It has been suggested that this relation may be evidence for new physics,
beyond $\Lambda CDM$. In this letter we show that 32 galaxies from the MUGS2
match the SPARC acceleration relation. These cosmological simulations of star
forming, rotationally supported discs were simulated with a {\sc WMAP3}
$\Lambda CDM$ cosmology, and match the SPARC acceleration relation with less
scatter than the observational data. These results show that this acceleration
relation is a consequence of dissipative collapse of baryons, rather than being
evidence for exotic dark-sector physics or new dynamical laws.


title:
A new asteroseismic diagnostic for internal rotation in $\gamma$ Doradus
  stars

abstract:
  With four years of nearly-continuous photometry from Kepler, we are finally
in a good position to apply asteroseismology to $\gamma$ Doradus stars. In
particular several analyses have demonstrated the possibility to detect
non-uniform period spacings, which have been predicted to be directly related
to rotation. In the present work, we define a new seismic diagnostic for
rotation in $\gamma$ Doradus stars that are too rapidly rotating to present
rotational splittings. Based on the non uniformity of their period spacings, we
define the observable $\Sigma$ as the slope of the period spacing when plotted
as a function of period. We provide a one-to-one relation between this
observable $\Sigma$ and the internal rotation, which applies widely in the
instability strip of $\gamma$ Doradus stars. We apply the diagnostic to a
handful of stars observed by Kepler. Thanks to g-modes in $\gamma$ Doradus
stars, we are now able to determine the internal rotation of stars on the lower
main sequence, which is still not possible for Sun-like stars.


title:
The radii and limb darkenings of Alpha Centauri A and B -
  Interferometric measurements with VLTI/PIONIER

abstract:
  The photospheric radius is one of the fundamental parameters governing the
radiative equilibrium of a star. We report new observations of the nearest
solar-type stars Alpha Centauri A (G2V) and B (K1V) with the VLTI/PIONIER
optical interferometer. The combination of four configurations of the VLTI
enable us to measure simultaneously the limb darkened angular diameter thetaLD
and the limb darkening parameters of the two solar-type stars in the
near-infrared H band (lambda = 1.65 microns). We obtain photospheric angular
diameters of thetaLD(A) = 8.502 +/- 0.038 mas (0.43%) and thetaLD(B) = 5.999
+/- 0.025 mas (0.42%), through the adjustment of a power law limb darkening
model. We find H band power law exponents of alpha(A) = 0.1404 +/- 0.0050
(3.6%) and alpha(B) = 0.1545 +/- 0.0044 (2.8%), which closely bracket the
observed solar value (alpha_sun = 0.15027). Combined with the parallax pi =
747.17 +/- 0.61 mas recently determined, we derive linear radii of RA = 1.2234
+/- 0.0053 Rsun (0.43%) and RB = 0.8632 +/- 0.0037 Rsun (0.43%). The power law
exponents that we derive for the two stars indicate a significantly weaker limb
darkening than predicted by both 1D and 3D stellar atmosphere models. As this
discrepancy is also observed on near-infrared limb darkening profile of the
Sun, an improvement of the calibration of stellar atmosphere models is clearly
needed. The reported PIONIER visibility measurements of Alpha Cen A and B
provide a robust basis to validate the future evolutions of these models.


title: Universality of Sparse $d>2$ Conformal Field Theory at Large $N$

abstract:
  We derive necessary and sufficient conditions for large $N$ conformal field
theories to have a universal free energy and an extended range of validity of
the higher-dimensional Cardy formula. These constraints are much tighter than
in two dimensions and must be satisfied by any conformal field theory dual to
Einstein gravity. We construct and analyze symmetric product orbifold theories
on $\mathbb{T}^d$ and show that they only realize the necessary phase structure
and extended range of validity if the seed theory is assumed to have a
universal vacuum energy.


title:
Testing universality of cosmic-ray acceleration with proton/helium data
  from AMS and Voyager-1

abstract:
  The AMS experiment has recently measured the proton and helium spectra in
cosmic rays (CRs) in the GeV-TeV energy region. The two spectra are found to
progressively harden at rigidity $R = pc/Z >\,$200 GV, while the p/He ratio is
found to fall off steadily as $p/He\sim\,R^{-0.08}$. The p/He decrease is often
interpreted in terms of particle-dependent acceleration, which is in contrast
with the universal nature of DSA mechanisms. A different explanation is that
the p-He anomaly reflects a flux transition between two components: a sub-TeV
flux component (L) provided by hydrogen-rich supernova remnants with soft
acceleration spectra, and a multi-TeV component (G) injected by younger sources
with amplified magnetic fields and hard spectra. In this scenario the
universality of particle acceleration is not violated because both sources
provide composition-blind injection spectra. The present work is aimed at
testing this model using the low-energy CR flux which is expected to be
L-dominated. However, at $E\sim\,$0.5-10 GeV, the fluxes are affected by energy
losses and solar modulation for which a proper modeling is required. To set the
properties of the L-source, I have used the Voyager-1 data collected in the
interstellar space. To compare my calculations with the AMS data, I have
performed a determination of the force-field modulation parameter using neutron
monitor measurements. I will show that the recent $p-He$ data reported by AMS
and Voyager-1 are in good agreement with the predictions of such a scenario,
supporting the hypothesis that CRs are injected in the Galaxy by universal,
composition-blind accelerators. At energies below $\sim\,$0.5 GeV/n, however,
the model is found to underpredict the data collected by PAMELA from 2006 to
2010. This discrepancy is found to increase with increasing solar activity,
reflecting an expected breakdown of the force-field approximation.


title: Small-$x$ asymptotics of the quark helicity distribution

abstract:
  We construct a numerical solution of the small-$x$ evolution equations
recently derived in \cite{Kovchegov:2015pbl} for the (anti)quark helicity TMDs
and PDFs as well as the $g_1$ structure function. We focus on the case of large
$N_c$ where one finds a closed set of equations. Employing the extracted
intercept, we are able to predict directly from theory the behavior of the
helicity PDFs at small $x$, which should have important phenomenological
consequences. We also give an estimate of how much of the proton's spin may be
at small $x$ and what impact this has on the so-called "spin crisis."


title:
MOND Prediction for the Velocity Dispersion of the `Feeble Giant' Crater
  II

abstract:
  Crater II is an unusual object among the dwarf satellite galaxies of the
Local Group in that it has a very large size for its small luminosity. This
provides a strong test of MOND, as Crater II should be in the deep MOND regime
($g_{in} \approx 34\;\mathrm{km}^2\,\mathrm{s}^{-2}\,\mathrm{kpc}^{-1} \ll a_0
= 3700\;\mathrm{km}^2\,\mathrm{s}^{-2}\,\mathrm{kpc}^{-1}$). Despite its great
distance ($\approx 120$ kpc) from the Milky Way, the external field of the host
($g_{ex} \approx 282\; \mathrm{km}^2\,\mathrm{s}^{-2}\,\mathrm{kpc}^{-1}$)
comfortably exceeds the internal field. Consequently, Crater II should be
subject to the external field effect, a feature unique to MOND. This leads to
the prediction of a very low velocity dispersion: $\sigma_{efe} =
2.1^{+0.9}_{-0.6}\;\mathrm{km}\,\mathrm{s}^{-1}$.


title:
Simulations of the Fe K-alpha Energy Spectra from Gravitationally
  Microlensed Quasars

abstract:
  The analysis of the Chandra X-ray observations of the gravitationally lensed
quasar RX J1131-1231 revealed the detection of multiple and energy-variable
spectral peaks. The spectral variability is thought to result from the
microlensing of the Fe K-alpha emission, selectively amplifying the emission
from certain regions of the accretion disk with certain effective frequency
shifts of the Fe K-alpha line emission. In this paper, we combine detailed
simulations of the emission of Fe K-alpha photons from the accretion disk of a
Kerr black hole with calculations of the effect of gravitational microlensing
on the observed energy spectra. The simulations show that microlensing can
indeed produce multiply peaked energy spectra. We explore the dependence of the
spectral characteristics on black hole spin, accretion disk inclination, corona
height, and microlensing amplification factor, and show that the measurements
can be used to constrain these parameters. We find that the range of observed
spectral peak energies of QSO RX J1131-1231 can only be reproduced for black
hole inclinations exceeding 70 degree and for lamppost corona heights of less
than 30 gravitational radii above the black hole. We conclude by emphasizing
the scientific potential of studies of the microlensed Fe K$\alpha$ quasar
emission and the need for more detailed modeling that explores how the results
change for more realistic accretion disk and corona geometries and microlensing
magnification patterns. A full analysis should furthermore model the
signal-to-noise ratio of the observations and the resulting detection biases.


title:
Interplay of non-symmorphic symmetry and spin-orbit coupling in
  hyperkagome spin liquids: Applications to Na$_4$Ir$_3$O$_8$

abstract:
  Na$_4$Ir$_3$O$_8$ provides a material platform to study three-dimensional
quantum spin liquids in the geometrically frustrated hyperkagome lattice of
Ir$^{4+}$ ions. In this work, we consider quantum spin liquids on hyperkagome
lattice for generic spin models, focusing on the effects of anisotropic spin
interactions. In particular, we classify possible $\mathbb{Z}_2$ and $U(1)$
spin liquid states, following the projective symmetry group analysis in the
slave-fermion representation. There are only three distinct $\mathbb{Z}_2$ spin
liquids, together with 2 different $U(1)$ spin liquids. The non-symmorphic
space group symmetry of hyperkagome lattice plays a vital role in simplifying
the classification, forbidding "$\pi$-flux" or "staggered-flux" phases in
contrast to symmorphic space groups. We further prove that both $U(1)$ states
and one $Z_2$ state among all 3 are symmetry-protected gapless spin liquids,
robust against any symmetry-preserving perturbations. Motivated by the
"spin-freezing" behavior recently observed in Na$_4$Ir$_3$O$_8$ at low
temperatures, we further investigate the nearest-neighbor spin model with
dominant Heisenberg interaction subject to all possible anisotropic
perturbations from spin-orbit couplings. We found a $U(1)$ spin liquid ground
state with spinon fermi surfaces is energetically favored over $Z_2$ states.
Among all spin-orbit coupling terms, we show that only Dzyaloshinskii-Moriya
(DM) interaction can induce spin anisotropy in the ground state when perturbing
from the isotropic Heisenberg limit. Our work paves the way for a systematic
study of quantum spin liquids in various materials with a hyperkagome crystal
structure.


title: Initial conditions for inflation

abstract:
  Within the $\alpha$-attractors framework we investigate scalar potentials
with the same pole as the one featured in the kinetic term. We show that, in
field space, this leads to directions without a plateau. Using this, we present
a proposal, which manages to overcome the initial conditions problem of
inflation with a plateau. An earlier period of proto-inflation, beginning at
Planck scale, accounts for the Universe expansion and arranges the required
initial conditions for inflation on the plateau to commence. We show that, if
proto-inflation is power-law, it does not suffer from a sub-Planckian eternal
inflationary stage, which would otherwise be a problem. A simple model
realisation is constructed in the context of $\alpha$-attractors, which can
both generate the inflationary plateau and the exponential slopes around it,
necessary for the two inflation stages. Our mechanism allows to assume chaotic
initial conditions at the Planck scale for proto-inflation, it is generic and
it is shown to work without fine-tuning.


title: Breit-Wigner approximation for propagators of mixed unstable states

abstract:
  For systems of unstable particles that mix with each other, an approximation
of the fully momentum-dependent propagator matrix is presented in terms of a
sum of simple Breit-Wigner propagators that are multiplied with finite on-shell
wave function normalisation factors. The latter are evaluated at the complex
poles of the propagators. The pole structure of general propagator matrices is
carefully analysed, and it is demonstrated that in the proposed approximation
imaginary parts arising from absorptive parts of loop integrals are properly
taken into account. Applying the formalism to the neutral MSSM Higgs sector
with complex parameters, very good numerical agreement is found between cross
sections based on the full propagators and the corresponding cross sections
based on the described approximation. The proposed approach does not only
technically simplify the treatment of propagators with non-vanishing
off-diagonal contributions, it is shown that it can also facilitate an improved
theoretical prediction of the considered observables via a more precise
implementation of the total widths of the involved particles. It is also
well-suited for the incorporation of interference effects arising from
overlapping resonances.


title: Robust and Parallel Bayesian Model Selection

abstract:
  Effective and accurate model selection is an important problem in modern data
analysis. One of the major challenges is the computational burden required to
handle large data sets that cannot be stored or processed on one machine.
Another challenge one may encounter is the presence of outliers and
contaminations that damage the inference quality. The parallel "divide and
conquer" model selection strategy divides the observations of the full data set
into roughly equal subsets and perform inference and model selection
independently on each subset. After local subset inference, this method
aggregates the posterior model probabilities or other model/variable selection
criteria to obtain a final model by using the notion of geometric median. This
approach leads to improved concentration in finding the "correct" model and
model parameters and also is provably robust to outliers and data
contamination.


title:
Nonstationary POT modelling of air pollution concentrations: Statistical
  analysis of the traffic and meteorological impact

abstract:
  Predicting the occurrence, level and duration of high air pollution
concentrations exceeding a given critical level enables researchers to study
the health impact of road traffic on local air quality and to inform public
policy action. Precise estimates of the probabilities of occurrence and level
of extreme concentrations are formidable due to the combination of complex
physical and chemical processes involved. This underpins the need for
developing sophisticated extreme value models, in particular allowing for
non-stationarity of environmental time series. In this paper, extremes of
nitrogen oxide (NO), nitrogen dioxide (NO$_2$) and ozone (O$_3$) concentrations
are investigated using two models. Model I is based on an extended
peaks-over-threshold (POT) approach developed by A. C. Davison and R. L. Smith,
whereby the parameters of the underlying generalized Pareto distribution (GPD)
are treated as functions of covariates (i.e., traffic and meteorological
factors). The new Model II resolves the lack of threshold stability in the
Davison--Smith model by constructing a special functional form for the GPD
parameters. For each of the models, the effects of trafic and meteorological
factors on the frequency and size of extreme values are estimated using Markov
chain Monte Carlo methods. Finally, appropriate goodness-of-fit tests and model
selection criteria confirm that Model II significantly outperforms Model I in
estimation and forecasting of extremes.


title: Structure of radiation dominated gravitoturbulent quasar discs

abstract:
  Self-gravitating accretion discs in a gravitoturbulent state, including
radiation and gas pressures, are studied using a set of new analytical
solutions. While the Toomre parameter of the disc remains close to its critical
value for the onset of gravitational instability, the dimensionless stress
parameter is uniquely determined from the thermal energy reservoir of the disc
and its cooling rate. Our solutions are applicable to the accretion discs with
dynamically important radiation pressure like in the quasars discs. We show
that physical quantities of a gravitoturbulent disc in the presence of
radiation are significantly modified compared to solutions with only gas
pressure. We show that the dimensionless stress parameter is an increasing
function of the radial distance so that its steepness strongly depends on the
accretion rate. In a disc without radiation its slope is 4.5, however, we show
that in the presence of radiation, it varies between 2 and 4.5 depending on the
accretion rate and the central mass. As for the surface density, we find a
shallower profile with an exponent -2 in a disc with sub-Eddington accretion
rate compared to a similar disc, but without radiation, where its surface
density slope is -3 independent of the accretion rate. We then investigate
gravitational stability of the disc when the stress parameter reaches to its
critical value. In order to self-consistently determine the fragmentation
boundary, however, it is shown that the critical value of the stress parameter
is a power-law function of the ratio of gas pressure and the total pressure and
its exponent is around 1.7. We also estimate the maximum mass of the central
black hole using our analytical solutions.


title:
Helicity Evolution at Small $x$: Flavor Singlet and Non-Singlet
  Observables

abstract:
  We extend our earlier results for the quark helicity evolution at small $x$
to derive the small-$x$ asymptotics of the flavor singlet and flavor
non-singlet quark helicity TMDs and PDFs and of the $g_1$ structure function.
In the flavor singlet case we re-derive the evolution equations obtained in our
previous paper on the subject, performing additional cross-checks of our
results. In the flavor non-singlet case we construct new small-$x$ evolution
equations by employing the large-$N_c$ limit. All evolution equations resum
double-logarithmic powers of $\alpha_s \, \ln^2 (1/x)$ in the
polarization-dependent evolution along with the single-logarithmic powers of
$\alpha_s \, \ln (1/x)$ in the unpolarized evolution which includes saturation
effects. We solve the linearized flavor non-singlet equation analytically,
obtaining an intercept which agrees with the one calculated earlier by Bartels,
Ermolaev and Ryskin using the infra-red evolution equations. Our numerical
solution of the linearized large-$N_c$ evolution equations for the flavor
singlet case is presented in the accompanying Letter and is further discussed
here.


title: Localization of interacting Fermi gases in quasiperiodic potentials

abstract:
  We investigate the zero-temperature metal-insulator transition in a
one-dimensional two-component Fermi gas in the presence of a quasi-periodic
potential resulting from the superposition of two optical lattices of equal
intensity but incommensurate periods. A mobility edge separating (low energy)
Anderson localized and (high energy) extended single-particle states appears in
this continuous-space model beyond a critical intensity of the quasi-periodic
potential. In order to discern the metallic phase from the insulating phase in
the interacting many-fermion system, we employ unbiased quantum Monte Carlo
(QMC) simulations combined with the many-particle localization length familiar
from the modern theory of the insulating state. In the noninteracting limit,
the critical optical-lattice intensity for the metal-insulator transition
predicted by the QMC simulations coincides with the Anderson localization
transition of the single-particle eigenstates. We show that weak repulsive
interactions induce a shift of this critical point towards larger intensities,
meaning that repulsion favors metallic behavior. This shift appears to be
linear in the interaction parameter, suggesting that even infinitesimal
interactions can affect the position of the critical point.


title: Better Streaming Algorithms for the Maximum Coverage Problem

abstract:
  We study the classic NP-Hard problem of finding the maximum $k$-set coverage
in the data stream model: given a set system of $m$ sets that are subsets of a
universe $\{1,\ldots,n \}$, find the $k$ sets that cover the most number of
distinct elements. The problem can be approximated up to a factor $1-1/e$ in
polynomial time. In the streaming-set model, the sets and their elements are
revealed online. The main goal of our work is to design algorithms, with
approximation guarantees as close as possible to $1-1/e$, that use sublinear
space $o(mn)$. Our main results are:
  Two $(1-1/e-\epsilon)$ approximation algorithms: One uses $O(\epsilon^{-1})$
passes and $\tilde{O}(\epsilon^{-2} k)$ space whereas the other uses only a
single pass but $\tilde{O}(\epsilon^{-2} m)$ space.
  We show that any approximation factor better than $(1-(1-1/k)^k)$ in constant
passes requires $\Omega(m)$ space for constant $k$ even if the algorithm is
allowed unbounded processing time. We also demonstrate a single-pass,
$(1-\epsilon)$ approximation algorithm using $\tilde{O}(\epsilon^{-2} m \cdot
\min(k,\epsilon^{-1}))$ space.
  We also study the maximum $k$-vertex coverage problem in the dynamic graph
stream model. In this model, the stream consists of edge insertions and
deletions of a graph on $N$ vertices. The goal is to find $k$ vertices that
cover the most number of distinct edges.
  We show that any constant approximation in constant passes requires
$\Omega(N)$ space for constant $k$ whereas $\tilde{O}(\epsilon^{-2}N)$ space is
sufficient for a $(1-\epsilon)$ approximation and arbitrary $k$ in a single
pass.
  For regular graphs, we show that $\tilde{O}(\epsilon^{-3}k)$ space is
sufficient for a $(1-\epsilon)$ approximation in a single pass. We generalize
this to a $(\kappa-\epsilon)$ approximation when the ratio between the minimum
and maximum degree is bounded below by $\kappa$.


title:
The Tungsten Project: Dielectronic Recombination Data For
  Collisional-Radiative Modelling In ITER

abstract:
  Tungsten is an important metal in nuclear fusion reactors. It will be used in
the divertor component of ITER (Latin for 'the way'). The Tungsten Project aims
to calculate partial and total DR rate coefficients for the isonuclear sequence
of Tungsten. The calculated data will be made available as and when they are
produced via the open access database OPEN- ADAS in the standard adf09 and
adf48 file formats. We present our progress thus far, detailing calculational
methods, and showing comparisons with other available data. We conclude with
plans for the future.


title: Two constructions of virtually contact structures

abstract:
  Motivated by recent developments in proving the Weinstein conjecture we
introduce the notion of covering contact connected sum for virtually contact
manifolds and construct virtually contact structures on boundaries of
subcritical handle bodies.


title:
Plancherel decomposition of Howe duality and Euler factorization of
  automorphic functionals

abstract:
  There are several global functionals on irreducible automorphic
representations which are Eulerian, that is: pure tensors of local functionals,
when the representation is written as an Euler product $\pi = \otimes'_v \pi_v$
of local representations. The precise factorization of such functionals is of
interest to number theorists and is -- naturally -- very often related to
special values of $L$-functions.
  The purpose of this paper is to develop in full generality the Plancherel
formula for the Weil or oscillator representation, considered as a unitary
representation of a reductive dual pair, and to use it in order to demonstrate
a very general principle of Euler factorization: local factors are determined
via the Langlands correspondence by a local Plancherel formula. This pattern
has already been observed and conjectured in the author's prior work with
Venkatesh in the case of period integrals. Here, it is shown that the Rallis
inner product formula amounts to the same principle in the setting of global
Howe duality.


title: A high-order staggered meshless method for elliptic problems

abstract:
  We present a new meshless method for scalar diffusion equations which is
motivated by their compatible discretizations on primal-dual grids. Unlike the
latter though, our approach is truly meshless because it only requires the
graph of nearby neighbor connectivity of the discretization points $\bm{x}_i$.
This graph defines a local primal-dual grid complex with a \emph{virtual} dual
grid, in the sense that specification of the dual metric attributes is implicit
in the method's construction. Our method combines a topological gradient
operator on the local primal grid with a Generalized Moving Least Squares
approximation of the divergence on the local dual grid. We show that the
resulting approximation of the div-grad operator maintains polynomial
reproduction to arbitrary orders and yields a meshless method, which attains
$O(h^{m})$ convergence in both $L^2$ and $H^1$ norms, similar to mixed finite
element methods. We demonstrate this convergence on curvilinear domains using
manufactured solutions. Application of the new method to problems with
discontinuous coefficients reveals solutions that are qualitatively similar to
those of compatible mesh-based discretizations.


title: A Reinforcement Learning Approach to the View Planning Problem

abstract:
  We present a Reinforcement Learning (RL) solution to the view planning
problem (VPP), which generates a sequence of view points that are capable of
sensing all accessible area of a given object represented as a 3D model. In
doing so, the goal is to minimize the number of view points, making the VPP a
class of set covering optimization problem (SCOP). The SCOP is NP-hard, and the
inapproximability results tell us that the greedy algorithm provides the best
approximation that runs in polynomial time. In order to find a solution that is
better than the greedy algorithm, (i) we introduce a novel score function by
exploiting the geometry of the 3D model, (ii) we model an intuitive human
approach to VPP using this score function, and (iii) we cast VPP as a Markovian
Decision Process (MDP), and solve the MDP in RL framework using well-known RL
algorithms. In particular, we use SARSA, Watkins-Q and TD with function
approximation to solve the MDP. We compare the results of our method with the
baseline greedy algorithm in an extensive set of test objects, and show that we
can out-perform the baseline in almost all cases.


title: Natural generalized mirage mediation

abstract:
  In the supersymmetric scenario known as mirage mediation (MM), the soft SUSY
breaking terms receive comparable anomaly-mediation and moduli-mediation
contributions leading to the phenomenon of mirage unification. The simplest MM
SUSY breaking models which are consistent with the measured Higgs mass and
sparticle mass constraints are strongly disfavoured by fine-tuning
considerations. However, while MM makes robust predictions for gaugino masses,
the scalar sector is quite sensitive to specific mechanisms for moduli
stabilization and potential uplifting. We suggest here a broader setup of
generalized mirage mediation (GMM), where heretofore discrete parameters are
allowed as continuous to better parametrize these other schemes. We find that
natural SUSY spectra consistent with both the measured value of m(h). as well
as LHC lower bounds on superpartner masses are then possible. We explicitly
show that models generated from natural GMM may be beyond the reach of even
high-luminosity LHC searches. In such a case, the proposed International Linear
e^+e^- Collider (ILC) will be required for natural SUSY discovery via higgsino
pair production reactions. We also outline prospects for detection of
higgsino-like WIMPs from natural GMM.


title: HERUS: A CO Atlas from SPIRE Spectroscopy of local ULIRGs

abstract:
  We present the Herschel SPIRE Fourier Transform Spectroscopy (FTS) atlas for
a complete flux limited sample of local Ultra-Luminous Infra-Red Galaxies as
part of the HERschel ULIRG Survey (HERUS). The data reduction is described in
detail and was optimized for faint FTS sources with particular care being taken
with the subtraction of the background which dominates the continuum shape of
the spectra. Special treatment in the data reduction has been given to any
observation suffering from artefacts in the data caused by anomalous
instrumental effects to improve the final spectra. Complete spectra are shown
covering $200 - 671\mu$m with photometry in the SPIRE bands at 250$\mu$m,
350$\mu$m and 500$\mu$m. The spectra include near complete CO ladders for over
half of our sample, as well as fine structure lines from [CI] 370 $\mu$m, [CI]
609 $\mu$m, and [NII] 205 $\mu$m. We also detect H$_{2}$O lines in several
objects. We construct CO Spectral Line Energy Distributions (SLEDs) for the
sample, and compare their slopes with the far-infrared colours and
luminosities. We show that the CO SLEDs of ULIRGs can be broadly grouped into
three classes based on their excitation. We find that the mid-J (5$<$J$<$8)
lines are better correlated with the total far-infrared luminosity, suggesting
that the warm gas component is closely linked to recent star-formation. The
higher J transitions do not linearly correlate with the far-infrared
luminosity, consistent with them originating in hotter, denser gas unconnected
to the current star-formation. {\bf We conclude that in most cases more than
one temperature components are required to model the CO SLEDs.}


title: Elliptic Polylogarithms and Basic Hypergeometric Functions

abstract:
  Multiple elliptic polylogarithms can be written as (multiple) integrals of
products of basic hypergeometric functions. The latter are computable, to
arbitrary precision, using a q-difference equation and q-contiguous relations.


title:
A Loomis-Sikorski theorem and functional calculus for a generalized
  Hermitian algebra

abstract:
  A generalized Hermitian (GH-) algebra is a generalization of the partially
ordered Jordan algebra of all Hermitian operators on a Hilbert space. We
introduce the notion of a gh-tribe, which is a commutative GH-algebra of
functions on a nonempty set $X$ with pointwise partial order and operations,
and we prove that every commutative GH-algebra is the image of a gh-tribe under
a surjective GH-morphism. Using this result, we prove each element $a$ of a
GH-algebra $A$ corresponds to a real observable $\xi_a$ on the
$\sigma$-orthomodular lattice of projections in $A$ and that $\xi_a$ determines
the spectral resolution of $a$. Also, if $f$ is a continuous function defined
on the spectrum of $a$, we formulate a definition of $f(a)$, thus obtaining a
continuous functional calculus for $A$.


title:
Structured adaptive and random spinners for fast machine learning
  computations

abstract:
  We consider an efficient computational framework for speeding up several
machine learning algorithms with almost no loss of accuracy. The proposed
framework relies on projections via structured matrices that we call Structured
Spinners, which are formed as products of three structured matrix-blocks that
incorporate rotations. The approach is highly generic, i.e. i) structured
matrices under consideration can either be fully-randomized or learned, ii) our
structured family contains as special cases all previously considered
structured schemes, iii) the setting extends to the non-linear case where the
projections are followed by non-linear functions, and iv) the method finds
numerous applications including kernel approximations via random feature maps,
dimensionality reduction algorithms, new fast cross-polytope LSH techniques,
deep learning, convex optimization algorithms via Newton sketches, quantization
with random projection trees, and more. The proposed framework comes with
theoretical guarantees characterizing the capacity of the structured model in
reference to its unstructured counterpart and is based on a general theoretical
principle that we describe in the paper. As a consequence of our theoretical
analysis, we provide the first theoretical guarantees for one of the most
efficient existing LSH algorithms based on the HD3HD2HD1 structured matrix
[Andoni et al., 2015]. The exhaustive experimental evaluation confirms the
accuracy and efficiency of structured spinners for a variety of different
applications.


title: A Theme-Rewriting Approach for Generating Algebra Word Problems

abstract:
  Texts present coherent stories that have a particular theme or overall
setting, for example science fiction or western. In this paper, we present a
text generation method called {\it rewriting} that edits existing
human-authored narratives to change their theme without changing the underlying
story. We apply the approach to math word problems, where it might help
students stay more engaged by quickly transforming all of their homework
assignments to the theme of their favorite movie without changing the math
concepts that are being taught. Our rewriting method uses a two-stage decoding
process, which proposes new words from the target theme and scores the
resulting stories according to a number of factors defining aspects of
syntactic, semantic, and thematic coherence. Experiments demonstrate that the
final stories typically represent the new theme well while still testing the
original math concepts, outperforming a number of baselines. We also release a
new dataset of human-authored rewrites of math word problems in several themes.


title: Diffractive processes at the LHC within $k_t$ -factorization approach

abstract:
  We discuss the single diffractive production of $c \bar c$ pairs and charmed
mesons at the LHC. In addition to standard collinear approach, for a first time
we propose a $k_t$-factorization approach to the diffractive processes. The
transverse momentum dependent (the unintegrated diffractive parton
distributions) in proton are obtained with the help of the Kimber-Martin-Ryskin
prescription where collinear diffractive PDFs are used as input. In this
calculation the transverse momentum of the pomeron is neglected with respect to
transverse momentum of partons entering the hard process. The results of the
new approach are compared with those of the standard collinear one.
Significantly larger cross sections are obtained in the $k_t$-factorization
approach where some part of higher-order effects is effectively included. Some
correlation observables, like azimuthal angle correlation between $c$ and $\bar
c$, and $c \bar c$ pair transverse momentum distribution were obtained for the
first time.


title:
RadioHound: A Pervasive Sensing Network for Sub-6 GHz Dynamic Spectrum
  Monitoring

abstract:
  We design a custom spectrum sensing network, called RadioHound, capable of
tuning from 25 MHz to 6 GHz, which covers nearly all widely-deployed wireless
activity. We describe the system hardware and network infrastructure in detail
with a view towards driving the cost, size, and power usage of the sensors as
low as possible. The system estimates the spatial variation of radio-frequency
power from an unknown random number of sources. System performance is measured
by computing the mean square error against a simulated radio-frequency
environment. We find that the system performance depends heavily on the
deployment density of the sensors. Consequently, we derive an expression for
the sensor density as a function of environmental characteristics and
confidence in measurement quality.