title: Cortical Geometry Network and Topology Markers for Parkinson's Disease

abstract:
  Neurodegeneration affects cortical gray matter leading to loss of cortical
mantle volume. As a result of such volume loss, the geometrical arrangement of
the regions on the cortical surface is expected to be altered in comparison to
healthy brains. Here we present a novel method to study the alterations in
brain cortical surface geometry in Parkinson's disease (PD) subjects with a
\emph{Geometry Networks (GN)} framework. The local geometrical arrangement of
the cortical surface is captured as the 3D coordinates of the centroids of
anatomically defined parcels on the surface. The inter-regional distance
between cortical patches is the signal of interest and is captured as a
geometry network. We study its topology by computing the dimensionality of
simplicial complexes induced on a filtration of binary undirected networks for
each geometry network. In a permutation statistics test, a statistically
significant ($p<0.05$) difference was observed in the homology features between
PD and healthy control groups highlighting its potential to differentiate
between the groups and their potential utility in disease diagnosis.


title:
Power Efficiency and Delay Tradeoff of 10GBase-T Energy Efficient
  Ethernet Protocol

abstract:
  In this paper, we study the power efficiency and delay performance of the
IEEE 802.3az Energy Efficient Ethernet (EEE) protocol. A new approach is
proposed to analyze the M/G/1 queue with the vacation time that is governed by
the arrival process and the parameter {\tau} and N of the BTR strategy. Our key
idea is to establish the connection between the vacation time and the arrival
process to account for their dependency. We first derive the distribution of
the number of arrivals during a vacation time based on an event tree of the BTR
strategy, from which we obtain the mean vacation time and the power efficiency.
Next, from the condition on the number of arrivals at the end of a vacation
period, we derive a generalized P-K formula of the mean delay for EEE systems,
and prove that the classical P-K formula of the vacation model is only a
special case when the vacation time is independent of the arrival process. Our
analysis demonstrates that the {\tau} policy and N policy of the BTR strategy
are compensating each other. The {\tau} policy ensures the frame delay is
bounded when the traffic load is light, while the N policy ensures the queue
length at the end of vacation is bounded when the traffic load is heavy. These
results, in turn, provide the rules to select appropriate {\tau} and N. Our
analytical results are confirmed by simulations.


title: Collective navigation of complex networks: Participatory greedy routing

abstract:
  Many networks are used to transfer information or goods, in other words, they
are navigated. The larger the network, the more difficult it is to navigate
efficiently. Indeed, information routing in the Internet faces serious
scalability problems due to its rapid growth, recently accelerated by the rise
of the Internet of Things. Large networks like the Internet can be navigated
efficiently if nodes, or agents, actively forward information based on hidden
maps underlying these systems. However, in reality most agents will deny to
forward messages, which has a cost, and navigation is impossible. Can we design
appropriate incentives that lead to participation and global navigability?
Here, we present an evolutionary game where agents share the value generated by
successful delivery of information or goods. We show that global navigability
can emerge, but its complete breakdown is possible as well. Furthermore, we
show that the system tends to self-organize into local clusters of agents who
participate in the navigation. This organizational principle can be exploited
to favor the emergence of global navigability in the system.

categories: physics.soc-ph nlin.AO physics.comp-ph physics.data-an


title:
Investigating the X-ray time-lags in PG 1244+026 using an extended
  corona model

abstract:
  We present an extended corona model based on ray-tracing simulations to
investigate X-ray time lags in Active Galactic Nuclei (AGN). This model
consists of two axial point sources illuminating an accretion disc that produce
the reverberation lags. These lags are due to the time delays between the
directly observed and reflection photons and are associated with the
light-travel time between the source and the disc, so they allow us to probe
the disc-corona geometry. We assume the variations of two X-ray sources are
triggered by the same primary variations, but allow the two sources to respond
in different ways (i.e. having different source responses). The variations of
each source induce a delayed accretion disc response and the total lags consist
of a combination of both source and disc responses. We show that the extended
corona model can reproduce both the low-frequency hard and high-frequency soft
(reverberation) lags. Fitting the model to the timing data of PG~1244+026
reveals the hard and soft X-ray sources at $\sim6r_{\text{g}}$ and
$\sim11r_{\text{g}}$, respectively. The upper source produces small amounts of
reflection and can be interpreted as a relativistic jet, or outflowing blob,
whose emission is beamed away from the disc. This explains the observed
lag-energy in which there is no soft lag at energies $<1$~keV as they are
diluted by the soft continuum of the upper source. Finally, our models suggest
that the fluctuations propagating between the two sources of PG~1244+026 are
possible but only at near the speed of light.


title:
Almost Everywhere Regularity for the Free Boundary of the Normalized
  p-harmonic Obstacle problem $p>2$

abstract:
  Let $u$ be a solution to the normalized p-harmonic obstacle problem with
$p>2$. That is, $u\in W^{1,p}(B_1(0))$, $2<p<\infty$, $u\ge 0$ and $$ \d\left(
|\nabla u|^{p-2}\nabla u\right)=\chi_{\{u>0\}}\textrm{ in }B_1(0) $$ where
$u(x)\ge 0$ and $\chi_A$ is the characteristic function of the set $A$. Our
main result is that for almost every free boundary point, with respect to the
$(n-1)-$Hausdorff measure, there is a neighborhood where the free boundary is a
$C^{1,\beta}-$graph. That is, for $\H^{n-1}-$a.e. point $x^0\in \partial
\{u>0\}\cap B_1(0)$ there is an $r>0$ such that $B_r(x^0)\cap \partial
\{u>0\}\in C^{1,\beta}$.


title: Analysis of the Kinematic Structure of the Cygnus OB1 association

abstract:
  The main objective of this study is the characterization of the velocity
field in the Cygnus OB1 association using the radial velocity data currently
available in the literature. This association is part of a larger star-forming
complex located in the direction of the Cygnus region, but whose main
subsystems may be distributed at different distances from the sun. We have
collected radial velocity data for more than 300 stars in the area of 5 x 5
square degrees centred on the Cygnus OB1 association. We present the results of
a kinematic clustering analysis in the subspace of the phase space formed by
angular coordinates and radial velocity using two independent methodologies. We
have found evidence of structure in the phase space with the detection of two
main groups, corresponding to different radial velocity and distance values,
belonging to the association, and associated with two main shells defined by
the Halpha emission. A third grouping well separated from the other two in
velocity appears to occupy the whole region associated with what has been
called "common shell".


title:
Joint Graph Decomposition and Node Labeling: Problem, Algorithms,
  Applications

abstract:
  We state a combinatorial optimization problem whose feasible solutions define
both a decomposition and a node labeling of a given graph. This problem offers
a common mathematical abstraction of seemingly unrelated computer vision tasks,
including instance-separating semantic segmentation, articulated human body
pose estimation and multiple object tracking. Conceptually, the problem we
state generalizes the unconstrained integer quadratic program and the minimum
cost lifted multicut problem, both of which are NP-hard. In order to find
feasible solutions efficiently, we define two local search algorithms that
converge monotonously to a local optimum, offering a feasible solution at any
time. To demonstrate their effectiveness in tackling computer vision tasks, we
apply these algorithms to instances of the problem that we construct from
published data, using published algorithms. We report state-of-the-art
application-specific accuracy for the three above-mentioned applications.


title: Heavy-Light Mesons in Chiral AdS/QCD

abstract:
  We discuss a minimal holographic model for the description of heavy-light and
light mesons with chiral symmetry, defined in a slab of AdS space. The model
consists of a pair of chiral Yang-Mills and tachyon fields with specific
boundary conditions that break spontaneously chiral symmetry in the infrared.
The heavy-light spectrum and decay constants are evaluated explicitly. In the
heavy mass limit the model exhibits both heavy-quark and chiral symmetry and
allows for the explicit derivation of the one-pion axial couplings to the
heavy-light mesons.


title:
Expanding hot flow in the black hole binary SWIFT J1753.5-0127: evidence
  from optical timing

abstract:
  We describe the evolution of optical and X-ray temporal characteristics
during the outburst decline of the black hole X-ray binary SWIFT J1753.5-0127.
The optical/X-ray cross-correlation function demonstrates a single positive
correlation at the outburst peak, then it has multiple dips and peaks during
the decline stage, which are then replaced by the precognition dip plus peak
structure in the outburst tail. Power spectral densities and phase lags show a
complex evolution, revealing the presence of intrinsically connected optical
and X-ray quasi-periodic oscillations. For the first time, we quantitatively
explain the evolution of these timing properties during the entire outburst
within one model, the essence of which is the expansion of the hot accretion
flow towards the tail of the outburst. The pivoting of the spectrum produced by
synchrotron Comptonization in the hot flow is responsible for the appearance of
the anti-correlation with the X-rays and for the optical quasi-periodic
oscillations. Our model reproduces well the cross-correlation and phase lag
spectrum during the decline stage, which could not be understood with any model
proposed before.


title:
Impact of strain and morphology on magnetic properties of
  Fe$_3$O$_4$/NiO bilayers grown on Nb:SrTiO$_3$(001) and MgO(001)

abstract:
  We present a comparative study on the morphology and structural as well as
magnetic properties of crystalline Fe$_3$O$_4$/NiO bilayers grown on both
MgO(001) and SrTiO$_3$(001) substrates by reactive molecular beam epitaxy.
These structures are investigated by means of x-ray photoelectron spectroscopy,
low energy electron diffraction, x-ray reflectivity and diffraction as well as
vibrating sample magnetometry. While the lattice mismatch of NiO grown on
MgO(001) is only 0.8%, it is exposed to a lateral lattice mismatch of -6.9% if
grown on SrTiO$_3$. In the case of Fe$_3$O$_4$, the misfit strain on MgO(001)
and SrTiO$_3$(001) amounts to 0.3% and -7.5%, respectively. To clarify the
relaxation process of the bilayer system, the film thicknesses of the magnetite
and nickel oxide films have been varied between 5 and 20nm. While NiO films are
well ordered on both substrates, Fe$_3$O$_4$ films grown on NiO/SrTiO$_3$
exhibit a higher surface roughness as well as lower structural ordering
compared to films grown on NiO/MgO. Further, NiO films grow pseudomorphic in
the investigated thickness range on MgO substrates without any indication of
relaxation, whereas on SrTiO$_3$ the NiO films show strong strain relaxation.
Fe$_3$O$_4$ films exhibit also strong relaxation even for films of 5nm
thickness on both NiO/MgO as well as on NiO/SrTiO$_3$. The magnetite layers on
both substrates show a fourfold magnetic in-plane anisotropy with magnetic easy
axes pointing in $\left\langle100\right\rangle$ directions. The coercive field
is strongly enhanced for magnetite grown on NiO/SrTiO$_3$ due to higher density
of structural defects, compared to magnetite grown on NiO/MgO.


title: Control of Fusion by Abelian Subgroups of the Hyperfocal Subgroup

abstract:
  We prove that an isomorphism between saturated fusion systems over the same
finite p-group is detected on the elementary abelian subgroups of the
hyperfocal subgroup if p is odd, and on the abelian subgroups of the hyperfocal
subgroup of exponent at most 4 if p = 2. For odd p, this has implications for
mod p group cohomology.


title:
Microscopic mechanisms of initial formation process of graphene on
  SiC(0001) surfaces

abstract:
  We report total-energy calculations based on the density-functional theory
that clarify microscopic mechanisms of initial stage of graphene formation on
the SiC(0001) surface. We explore favorable reactions for desorption of either
Si or C atoms from the stepped surface by determining the desorption and the
subsequent migration pathways and calculating the corresponding energy barriers
for the first time. We find that the energy barrier for the desorption of an Si
atom at the step edge and the subsequent migration toward stable terrace sites
are lower than that of a C atom by 0.75 eV, indicative of the selective
desorption of Si from the SiC surface. We also find that the subsequent Si
desorption is an exothermic reaction. This exothermicity comes from the energy
gain due to the bond formation of C atoms being left near the step edges. This
is certainly a seed of graphene flakes.


title: Bilinear-form invariants of Lefschetz fibrations over the 2-sphere

abstract:
  We introduce invariants of Hurwitz equivalence classes with respect to
arbitrary group $G$. The invariants are constructed from any right $G$-modules
$M$ and any $G$-invariant bilinear function on $M$, and are of bilinear forms.
For instance, when $G$ is the mapping class group of the closed surface,
$\mathcal{M}_g$, we get an invariant of 4-dimensional Lefschetz fibrations over
the 2-sphere. Moreover, the construction is applicable for the quantum
representations of $\mathcal{M}_g $ derived from Chern-Simons field theory. We
compute the associated invariants in some cases, and find infinitely many
Lefschetz fibrations which have the same Seiberg-Witten invariant and are
homeomorphic but not mutually isomorphic as fibrations.


title: The probability of extinction of ISAv in one and two patches

abstract:
  Single type and multitype branching process have been used to study the
dynamics of a variety of stochastic birth-death type phenomena in biology and
physics. Their use in epidemiology goes back to Whittle's study of a
Susceptible--Infected--Recovered (SIR) model in the 1950s. In the case of an
SIR model, the presence of only one infectious class allows for the use of
single type branching processes. Multitype branching processes allow for
multiple infectious classes and have latterly been used to study metapopulation
models of disease. In this article, we develop a Continuous Time Markov Chain
(CTMC) model of Infectious Salmon Anemia virus in two patches, two CTMC models
in one patch and companion multitype branching process (MTBP) models. The CTMC
models are related to deterministic models which inform the choice of
parameters. The probability of extinction is computed for the CTMC via
numerical methods and approximated by the MTBP in the supercritical regime. The
stochastic models are treated as toy models and the parameter choices are made
to highlight regions of the parameter space where CTMC and MTBP agree or
disagree, without regard to biological significance. Partial extinction events
are defined and their relevance discussed. A case is made for calculating the
probability of such events, noting that MTBP's are not suitable for making
these calculations.


title: Fair and Throughput-Optimal Routing in Multi-Modal Underwater Networks

abstract:
  While acoustic communications have been considered the prominent technology
to communicate under water for several years, other technologies are being
developed based, e.g., on optical and radio-frequency electro-magnetic waves.
Each technology has its own advantages and drawbacks: for example, acoustic
signals achieve long communication ranges at order-of-kbit/s bit rate, whereas
optical signals offer order-of-Mbit/s transmission rates but only over short
transmitter--receiver distances. Such a technological diversity can be
leveraged by multi-modal systems, which integrate different technologies and
provide intelligence to decide which one should be used at any given time. In
this paper, we address a fundamental part of this intelligence by proposing a
novel routing protocol for networks of multi-modal nodes. The protocol makes
distributed decisions about the flow in each link and over each technology at
any given time, in order to advance a packet towards its destination. Our
routing protocol prevents bottlenecks and allocates resources fairly to
different nodes. We analyze the performance of our protocol via simulations and
in a field experiment. The results show that our protocol successfully
leverages all technologies to deliver data, even in the presence of imperfect
topology information. To permit the reproduction of our results, we share our
simulation code.


title:
Cross section line shape of $e^+e^-\to\chi_{c0}\omega$ around the
  $Y(4260)$ mass region

abstract:
  We demonstrate that the recent measurement of the cross section line shapes
of $e^+e^-\to \chi_{c0}\omega$ can be naturally explained by the molecular
picture for $Y(4260)$ where the $Y(4260)$ is treated as a hadronic molecule
dominated by $\bar{D}D_1(2420)+c.c.$ This result is consistent with properties
extracted for $Y(4260)$ as the $\bar{D}D_1(2420)+c.c.$ molecular state in other
reactions such as $e^+e^-\to J/\psi\pi\pi$, $h_c\pi\pi$, $\bar D D^*\pi +c.c.$,
and $\gamma X(3872)$.


title:
Multi-centered ${\mathcal N}=2$ BPS black holes: a double copy
  description

abstract:
  We present the on-shell double copy dictionary for linearised ${\mathcal
N}=2$ supergravity coupled to an arbitrary number of vector multiplets in four
dimensions. Subsequently, we use it to construct a double copy description of
multi-centered BPS black hole solutions in these theories in the weak-field
approximation.


title: Quasi-asymptotically conical Calabi-Yau manifolds

abstract:
  We construct new examples of quasi-asymptotically conical (QAC) Calabi-Yau
manifolds that are not quasi-asymptotically locally Euclidean (QALE). We do so
by first providing a natural compactification of QAC-spaces by manifolds with
fibred corners and by giving a definition of QAC-metrics in terms of an
associated Lie algebra of smooth vector fields on this compactification. Thanks
to this compactification and the Fredholm theory for elliptic operators on
QAC-spaces developed by the second author and Mazzeo, we can in many instances
obtain K\"ahler QAC-metrics having Ricci potential decaying sufficiently fast
at infinity. This allows us to obtain QAC Calabi-Yau metrics in the K\"ahler
classes of these metrics by solving a corresponding complex Monge-Amp\`ere
equation.


title:
Secondary Phenotype Analysis in Ascertained Family Designs: Application
  to the Leiden Longevity Study

abstract:
  The case-control design is often used to test associations between the
case-control status and genetic variants. In addition to this primary phenotype
a number of additional traits, known as secondary phenotypes, are routinely
recorded and typically associations between genetic factors and these secondary
traits are studied too. Analysing secondary phenotypes in case-control studies
may lead to biased genetic effect estimates, especially when the marker tested
is associated with the primary phenotype and when the primary and secondary
phenotypes tested are correlated. Several methods have been proposed in the
literature to overcome the problem but they are limited to case-control studies
and not directly applicable to more complex designs, such as the multiple-cases
family studies. A proper secondary phenotype analysis, in this case, is
complicated by the within families correlations on top of the biased sampling
design. We propose a novel approach to accommodate the ascertainment process
while explicitly modelling the familial relationships. Our approach pairs
existing methods for mixed-effects models with the retrospective likelihood
framework and uses a multivariate probit model to capture the association
between the mixed type primary and secondary phenotypes. To examine the
efficiency and bias of the estimates we performed simulations under several
scenarios for the association between the primary phenotype, secondary
phenotype, and genetic markers. We will illustrate the method by analysing the
association between triglyceride levels and glucose (secondary phenotypes) and
genetic markers from the Leiden Longevity study, a multiple-cases family study
that investigates longevity.


title:
$D$-modules, Bernstein-Sato polynomials and $F$-invariants of direct
  summands

abstract:
  We study the structure of $D$-modules over a ring $R$ which is a direct
summand of a polynomial or a power series ring $S$ with coefficients over a
field. We relate properties of $D$-modules over $R$ to $D$-modules over $S$. We
show that the localization $R_f$ and the local cohomology module $H^i_I(R)$
have finite length as $D$-modules over $R$. Furthermore, we show the existence
of the Bernstein-Sato polynomial for elements in $R$. In positive
characteristic, we use this relation between $D$-modules over $R$ and $S$ to
show that the set of $F$-jumping numbers of an ideal $I\subseteq R$ is
contained in the set of $F$-jumping numbers of its extension in $S$. As a
consequence, the $F$-jumping numbers of $I$ in $R$ form a discrete set of
rational numbers. We also relate the Bernstein-Sato polynomial in $R$ with the
$F$-thresholds and the $F$-jumping numbers in $R$.


title:
Automatic discovery of discriminative parts as a quadratic assignment
  problem

abstract:
  Part-based image classification consists in representing categories by small
sets of discriminative parts upon which a representation of the images is
built. This paper addresses the question of how to automatically learn such
parts from a set of labeled training images. The training of parts is cast as a
quadratic assignment problem in which optimal correspondences between image
regions and parts are automatically learned. The paper analyses different
assignment strategies and thoroughly evaluates them on two public datasets:
Willow actions and MIT 67 scenes. State-of-the art results are obtained on
these datasets.


title:
Interference Cancellation at Receivers in Cache-Enabled Wireless
  Networks

abstract:
  In this paper, we propose to exploit the limited cache packets as side
information to cancel incoming interference at the receiver side. We consider a
stochastic network where the random locations of base stations and users are
modeled using Poisson point processes. Caching schemes to reap both the local
caching gain and the interference cancellation gain for the users are developed
based on two factors: the density of different user subsets and the packets
cached in the corresponding subsets. The packet loss rate (PLR) is analyzed,
which depends on both the cached packets and the channel state information
(CSI) available at the receiver. Theoretical results reveal the tradeoff
between caching resource and wireless resource. The performance for different
caching schemes are analyzed and the minimum achievable PLR for the distributed
caching is derived.


title: Approximated structured pseudospectra

abstract:
  Pseudospectra and structured pseudospectra are important tools for the
analysis of matrices. Their computation, however, can be very demanding for all
but small matrices. A new approach to compute approximations of pseudospectra
and structured pseudospectra, based on determining the spectra of many suitably
chosen rank-one or projected rank-one perturbations of the given matrix is
proposed. The choice of rank-one or projected rank-one perturbations is
inspired by Wilkinson's analysis of eigenvalue sensitivity. Numerical examples
illustrate that the proposed approach gives much better insight into the
pseudospectra and structured pseudospectra than random or structured random
rank-one perturbations with lower computational burden. The latter approach is
presently commonly used for the determination of structured pseudospectra.


title: On numerical approximation schemes for expectation propagation

abstract:
  Several numerical approximation strategies for the expectation-propagation
algorithm are studied in the context of large-scale learning: the Laplace
method, a faster variant of it, Gaussian quadrature, and a deterministic
version of variational sampling (i.e., combining quadrature with variational
approximation). Experiments in training linear binary classifiers show that the
expectation-propagation algorithm converges best using variational sampling,
while it also converges well using Laplace-style methods with smooth factors
but tends to be unstable with non-differentiable ones. Gaussian quadrature
yields unstable behavior or convergence to a sub-optimal solution in most
experiments.


title: Leech Constellations of Construction-A Lattices

abstract:
  The problem of communicating over the additive white Gaussian noise (AWGN)
channel with lattice codes is addressed in this paper. Theoretically, Voronoi
constellations have proved to yield very powerful lattice codes when the
fine/coding lattice is AWGN-good and the coarse/shaping lattice has an optimal
shaping gain. However, achieving Shannon capacity with these premises and
practically implementable encoding algorithms is in general not an easy task.
In this work, a new way to encode and demap Construction-A Voronoi lattice
codes is presented. As a meaningful application of this scheme, the second part
of the paper is focused on Leech constellations of low-density Construction-A
(LDA) lattices: LDA Voronoi lattice codes are presented whose numerically
measured waterfall region is situated at less than 0.8 dB from Shannon
capacity. These LDA lattice codes are based on dual-diagonal nonbinary
low-density parity-check codes. With this choice, encoding, iterative decoding,
and demapping have all linear complexity in the blocklength.


title:
Spin-chain model for strongly interacting one-dimensional Bose-Fermi
  mixtures

abstract:
  Strongly interacting one-dimensional (1D) Bose-Fermi mixtures form a tunable
XXZ spin chain. Within the spin-chain model developed here, all properties of
these systems can be calculated from states representing the ordering of the
bosons and fermions within the atom chain and from the ground-state wave
function of spinless noninteracting fermions. We validate the model by means of
an exact diagonalization of the full few-body Hamiltonian in the strongly
interacting regime. Using the model, we explore the phase diagram of the atom
chain as a function of the boson-boson (BB) and boson-fermion (BF) interaction
strengths and calculate the densities, momentum distributions, and trap-level
occupancies for up to 17 particles. In particular, we find antiferromagnetic
(AFM) and ferromagnetic (FM) order and a demixing of the bosons and fermions in
certain interaction regimes. We find, however, no demixing for equally strong
BB and BF interactions in agreement with earlier calculations that combined the
Bethe ansatz with a local-density approximation.


title:
Buffering Time Strategies for Wireless Full-duplex Systems under Poisson
  Traffic

abstract:
  Full-duplex wireless communication has the potential to double the capacity
of wireless networks by reducing the band occupancy of transmissions. However,
a full-duplex capability cannot always reduce the band occupancy because the
real traffic is not fully buffered. Buffering time while waiting for a packet
to arrive at an opposite node is expected to reduce the band occupancy. In this
study, we provide the first theoretical analysis of band occupancy and the mean
waiting time for full-duplex communication with and without buffering time
under traffic that is not fully buffered based on queueing theory, as well as
the closed-form results. We also present the results of simulations of band
occupancy and the mean waiting time. The basic analysis provided in this study
shows how the mean waiting time and band occupancy are affected by the
buffering time. When the buffering time is half the packet length, the band
occupancy is reduced by approximately 15 %. In addition, under asymmetrical
traffic, the results suggest that the buffering time should not be set at the
node who has a higher traffic intensity compared with another node. These
results support the design of a full-duplex medium access control protocol and
devices.


title: Stolarsky principle and energy optimization on the sphere

abstract:
  The classical Stolarsky invariance principle connects the spherical cap $L^2$
discrepancy of a finite point set on the sphere to the pairwise sum of
Euclidean distances between the points. In this paper we further explore and
extend this phenomenon. In addition to a new elementary proof of this fact, we
establish several new analogs, which relate various notions of discrepancy to
different discrete energies. In particular, we find that the hemisphere
discrepancy is related to the sum of geodesic distances. We also extend these
results to arbitrary measures on the sphere and arbitrary notions of
discrepancy and apply them to problems of energy optimization and combinatorial
geometry and find that, surprisingly, the geodesic distance energy behaves
differently than its Euclidean counterpart.


title: On the nature of an excited state

abstract:
  In many lattice simulations with dynamical quarks, radial or orbital
excitations of hadrons lie near multihadron thresholds: it makes the extraction
of excited states properties more challenging and can introduce some
systematics difficult to estimate without an explicit computation of
correlators using interpolating fields strongly coupled to multihadronic
states. In a recent study of the strong decay of the first radial excitation of
the $B^*$ meson, this issue has been investigated and we have clues that a
diquark interpolating field $\bar{b} \gamma^i q$ is very weakly coupled to a $B
\pi$ $P$-wave state while the situation is quite different if we consider an
interpolating field of the kind $\bar{b} \nabla^i q$, where $\vec{\nabla}$ is a
covariant derivative: those statements are based on examining the charge
density distribution.


title: Sharp Interface Limit for a Stokes/Allen-Cahn System

abstract:
  We consider the sharp interface limit of a coupled Stokes/Allen-Cahn system,
when a parameter $\varepsilon>0$ that is proportional to the thickness of the
diffuse interface tends to zero, in a two dimensional bounded domain. For
sufficiently small times we prove convergence of the solutions of the
Stokes/Allen-Cahn system to solutions of a sharp interface model, where the
interface evolution is given by the mean curvature equation with an additional
convection term coupled to a two-phase Stokes system with an additional
contribution to the stress tensor, which describes the capillary stress. To
this end we construct a suitable approximation of the solution of the
Stokes/Allen-Cahn system, using three levels of the terms in the formally
matched asymptotic calculations, and estimate the difference with the aid of a
suitable refinement of a spectral estimate of the linearized Allen-Cahn
operator. Moreover, a careful treatment of the coupling terms is needed.


title: Expertise revisited I: Interactional Expertise

abstract:
  The notion of interactional expertise is explained starting with its origins
and discussing its many applications. Interactional expertise is the ability to
understand a technical area purely be deeply immersed in its
'practice-language' without actually practising. One of its many applications
is to explain how large sciences are managed.


title:
New Developments in Killing Spinor Programme and More Motivations for
  Physics

abstract:
  This present work is based on our previous publications, which all together
trigger our "Killing spinor programme". Other significant spinor fields are
injected into the scheme and the intricate relations between them and their
bilinears are constructed here. The web of relations concerning these
constructions are presented clearly in a Venn diagram. Particular attention is
devoted to the construction of equations satisfied by the homogeneous bilinears
induced from Dirac spinors. Contacts with various physics theories are made
throughout the text and some of the future directions of the programme are
defined.


title:
The Drought-Stress Response of a Drought Resistant Impatiens Processed
  in PEG-6000 Solution in a Simulation Test

abstract:
  Premise of the Study: Impatiens is a commonly seen garden flower, renowned
for its strong adaptability and long history of cultivation. However, seldom
has any research touched on its physiological resistance mechanism. In this
experiment, the impatiens is selected from those which experienced aerospace
mutation and thereafter 12 years of cultivation and breeding. Therefore, it is
superior to the non-mutagenized impatiens in terms of drought resistance and
demonstrates tremendous differences from the normal impatiens in physiology,
which intrigues scholars to search for the underlying reasons . Methods: By
reference to Impatiens balsamina L,this experiment uses mutagenized impatiens
seeds, processed by PEG-6000 in different solution concentration, to measure
the germination rate of impatiens, its relative enzymatic activity and
expression differences between gene SoS2 and gene RD29b in the drought lower
reaches. Key results: Under simulated drought stress, there is no distinct
difference between the mutagenized impatiens and the normal impatiens in terms
of germination rate. But by measuring the root tillers and the length, the
relative enzymatic activity, MDA, and the expression differences between gene
SoS2 and gene RD29b in the drought lower reaches, it is verified that the
mutagenized impatiens has more advantages than the normal impatiens, and it Can
further cultivate become drought resistance varieties impatiens. Conclusions:
In this experiment,which is a positive mutation, the mutagenized impatiens
improves drought resistance through radiative mutation. The so obtained
impatiens is more pleasing in sight in terms of color and shape and has higher
application value in garden virescence.


title:
Quantifying the Information Leak in Cache Attacks through Symbolic
  Execution

abstract:
  Cache timing attacks allow attackers to infer the properties of a secret
execution by observing cache hits and misses. But how much information can
actually leak through such attacks? For a given program, a cache model, and an
input, our CHALICE framework leverages symbolic execution to compute the amount
of information that can possibly leak through cache attacks. At the core of
CHALICE is a novel approach to quantify information leak that can highlight
critical cache side-channel leaks on arbitrary binary code. In our evaluation
on real-world programs from OpenSSL and Linux GDK libraries, CHALICE
effectively quantifies information leaks: For an AES-128 implementation on
Linux, for instance, CHALICE finds that a cache attack can leak as much as 127
out of 128 bits of the encryption key.


title: Dynamics and energy spectra of aperiodic discrete-time quantum walks

abstract:
  Deterministically aperiodic sequences are an intermediary between periodic
sequences and completely random sequences. Materials which are translationally
periodic have Bloch-like extended states, while random media exhibit Anderson
localisation. Materials constructed on the basis of deterministic aperiodic
sequences such as Fibonacci, Thue-Morse, and Rudin-Shapiro exhibit different
properties, which can be related to their spectrum. Here, by investigating the
dynamics of discrete-time quantum walks using different aperiodic sequences of
coin operations in position space and time we establish the role of the
diffraction spectra in characterizing the spreading of the wavepacket.


title:
Correlated X-ray and optical variability in intermediate polars during
  their outbursts

abstract:
  We present a study of the evolution of the optical and X-ray fluxes during
outbursts of two short-period cataclysmic variables, the confirmed intermediate
polar CC Scl and the intermediate polar candidate FS Aur. We found that the
X-ray and optical light curves are well correlated in both objects, although
the amplitudes of outbursts in X-rays are smaller than those in the optical.
The ratio of the outburst amplitudes in X-rays and the optical in both objects
is close to ~0.6. This is significantly higher than was observed during the
outburst of the non-magnetic dwarf nova U Gem, in which this ratio was only
~0.03. The obtained data also suggest that the dependence between the X-ray and
optical fluxes must steepen significantly toward very low accretion rates and
very low fluxes. Similarities in the behaviour of CC Scl and FS Aur indicate
strongly the magnetic nature of the white dwarf in FS Aur.


title:
Matrix Characterization for GFDM Systems: Low-Complexity MMSE Receivers
  and Optimal Prototype Filters

abstract:
  In this paper, a new matrix-based characterization of
generalized-frequency-division-multiplexing (GFDM) transmitter matrices is
proposed, as opposed to traditional vector-based characterization with
prototype filters. The characterization facilitates deriving properties of GFDM
(transmitter) matrices, including conditions for GFDM matrices being
nonsingular and unitary, respectively. Using the new characterization, the
necessary and sufficient conditions for the existence of a form of
low-complexity implementation for a minimum mean square error (MMSE) receiver
are derived. Such an implementation exists under multipath channels if the GFDM
transmitter matrix is selected to be unitary. For cases where this
implementation does not exist, a low-complexity suboptimal MMSE receiver is
proposed, with its performance approximating that of an MMSE receiver. The new
characterization also enables derivations of optimal prototype filters in terms
of minimizing receiver mean square error (MSE). They are found to correspond to
the use of unitary GFDM matrices under many scenarios. The use of such optimal
filters in GFDM systems does not cause the problem of noise enhancement,
thereby demonstrating the same MSE performance as orthogonal frequency division
multiplexing. Moreover, we find that GFDM matrices with a size of power of two
are verified to exist in the class of unitary GFDM matrices. Finally, while the
out-of-band (OOB) radiation performance of systems using a unitary GFDM matrix
is not optimal in general, it is shown that the OOB radiation can be
satisfactorily low if parameters in the new characterization are carefully
chosen.


title: Positrons in Surface Physics

abstract:
  Within the last decade powerful methods have been developed to study surfaces
using bright low-energy positron beams. These novel analysis tools exploit the
unique properties of positron interaction with surfaces, which comprise the
absence of exchange interaction, repulsive crystal potential and positron
trapping in delocalized surface states at low energies. By applying reflection
high-energy positron diffraction (RHEPD) one can benefit from the phenomenon of
total reflection below a critical angle that is not present in electron surface
diffraction. Therefore, RHEPD allows the determination of the atom positions of
(reconstructed) surfaces with outstanding accuracy. The main advantages of
positron annihilation induced Auger-electron spectroscopy (PAES) are the
missing secondary electron background in the energy region of Auger-transitions
and its topmost layer sensitivity for elemental analysis. In order to enable
the investigation of the electron polarization at surfaces low-energy
spin-polarized positrons are used to probe the outermost electrons of the
surface. Furthermore, in fundamental research the preparation of well defined
surfaces tailored for the production of bound leptonic systems plays an
outstanding role. In this report, it is envisaged to cover both, the
fundamental aspects of positron surface interaction and the present status of
surface studies using modern positron beam techniques.


title:
C3, A Command-line Catalogue Cross-match tool for large astrophysical
  catalogues

abstract:
  Modern Astrophysics is based on multi-wavelength data organized into large
and heterogeneous catalogues. Hence, the need for efficient, reliable and
scalable catalogue cross-matching methods plays a crucial role in the era of
the petabyte scale. Furthermore, multi-band data have often very different
angular resolution, requiring the highest generality of cross-matching
features, mainly in terms of region shape and resolution. In this work we
present $C^{3}$ (Command-line Catalogue Cross-match), a multi-platform
application designed to efficiently cross-match massive catalogues. It is based
on a multi-core parallel processing paradigm and conceived to be executed as a
stand-alone command-line process or integrated within any generic data
reduction/analysis pipeline, providing the maximum flexibility to the end-user,
in terms of portability, parameter configuration, catalogue formats, angular
resolution, region shapes, coordinate units and cross-matching types. Using
real data, extracted from public surveys, we discuss the cross-matching
capabilities and computing time efficiency also through a direct comparison
with some publicly available tools, chosen among the most used within the
community, and representative of different interface paradigms. We verified
that the $C^{3}$ tool has excellent capabilities to perform an efficient and
reliable cross-matching between large datasets. Although the elliptical
cross-match and the parametric handling of angular orientation and offset are
known concepts in the astrophysical context, their availability in the
presented command-line tool makes $C^{3}$ competitive in the context of public
astronomical tools.


title: Conditions for Beurling's integers to have a density

abstract:
  In 1997 H.G.Diamond gave a condition on Beurling's generalized prime numbers
in order that the corresponding generalized integers have a density. We give a
new proof of this condition (Theorem 1) and a proof that it is not necessary
(Theorem 2 and Examples). However, it is very near to be necessary (Theorem 3).
Both proofs of Theorems 1 and 2 rely on Fourier analysis, mainly the Wiener
algebra, and partly on probability methods.


title: The Quamoco Product Quality Modelling and Assessment Approach

abstract:
  Published software quality models either provide abstract quality attributes
or concrete quality assessments. There are no models that seamlessly integrate
both aspects. In the project Quamoco, we built a comprehensive approach with
the aim to close this gap.
  For this, we developed in several iterations a meta quality model specifying
general concepts, a quality base model covering the most important quality
factors and a quality assessment approach. The meta model introduces the new
concept of a product factor, which bridges the gap between concrete
measurements and abstract quality aspects. Product factors have measures and
instruments to operationalise quality by measurements from manual inspection
and tool analysis. The base model uses the ISO 25010 quality attributes, which
we refine by 200 factors and 600 measures for Java and C# systems.
  We found in several empirical validations that the assessment results fit to
the expectations of experts for the corresponding systems. The empirical
analyses also showed that several of the correlations are statistically
significant and that the maintainability part of the base model has the highest
correlation, which fits to the fact that this part is the most comprehensive.
Although we still see room for extending and improving the base model, it shows
a high correspondence with expert opinions and hence is able to form the basis
for repeatable and understandable quality assessments in practice.


title:
Amplitude reconstruction from complete experiments and truncated
  partial-wave expansions

abstract:
  We compare the methods of amplitude reconstruction, for a complete experiment
and a truncated partial wave analysis, applied to the photoproduction of
pseudo-scalar mesons. The approach is pedagogical, showing in detail how the
amplitude reconstruction (observables measured at a single energy and angle) is
related to a truncated partial-wave analysis (observables measured at a single
energy and a number of angles).


title:
The Burrell Schmidt Deep Virgo Survey: Tidal Debris, Galaxy Halos, and
  Diffuse Intracluster Light in the Virgo Cluster

abstract:
  We present a deep imaging survey of the Virgo Cluster, designed to study the
connection between cluster galaxies and Virgo's diffuse intracluster light
(ICL). Our observations span roughly 16 square degrees and reach a 3-sigma
depth of mu(B)=29.5 and mu(V)=28.5 mag/arcsec^2. At these depths, the limiting
systematic uncertainties are astrophysical: scattered starlight from foreground
Galactic dust, and variations in faint background sources. The dust-scattered
starlight is well-traced by deep far-infrared imaging, making it
distinguishable from true Virgo diffuse light. Our imaging maps the Virgo core
around M87 and the adjacent M86/M84 region, in subcluster B around M49, and in
the more distant W' cloud around NGC 4365. Most of the detected ICL is found in
the Virgo core and within the W' cloud, with little evidence for extensive ICL
in subcluster B. The large amount of diffuse light seen in the infalling W'
cloud likely illustrates the importance of the group environment for generating
ICL. The bulk of the detected ICL is fairly red (B-V=0.7-0.9), indicative of
old stellar populations. We estimate a total Virgo ICL fraction of 7-15%,
somewhat smaller than expected for massive, evolved clusters, suggesting that
Virgo is still growing its ICL component. We trace M87's extremely boxy halo
out to ~ 150 kpc, and show that the current stripping rate of low luminosity
galaxies is insufficient to have built M87's outer halo over a Hubble time.
Finally, we identify another large ultra-diffuse galaxy in Virgo, likely in the
process of being shredded by the cluster tidal field.


title: The Orlicz-Petty bodies

abstract:
  This paper is dedicated to the Orlicz-Petty bodies. We first propose the
homogeneous Orlicz affine and geominimal surface areas, and establish their
basic properties such as homogeneity, affine invariance and affine
isoperimetric inequalities. We also prove that the homogeneous geominimal
surface areas are continuous, under certain conditions, on the set of convex
bodies in terms of the Hausdorff distance. Our proofs rely on the existence of
the Orlicz-Petty bodies and the uniform boundedness of the Orlicz-Petty bodies
of a convergent sequence of convex bodies. Similar results for the
nonhomogeneous Orlicz geominimal surface areas are proved as well.


title: $G$-parity violating amplitudes in the $J/\psi \to \pi^+ \pi^-$ decay

abstract:
  The decays of the negative $G$-parity meson $G$-parity into even numbers of
pions violate $G$-parity. Such decays, as well as other $G$-parity decays into
hadrons, can be parametrized in terms of three main intermediate virtual
states: one photon, one photon plus two gluons, and three gluons. Since the
electromagnetic interaction does not conserve $G$-parity, $G$-parity decays
into positive $G$-parity final states should be dominantly electromagnetic.
Nevertheless, the one-photon contribution to $J/\psi \to \pi^+ \pi^-$, that can
be estimated by exploiting the cross section $\sigma(e^+e^-\to \pi^+ \pi^-)$,
differs from the observed decay probability for {more than} 4.5 standard
deviations. We present a computation of the $gg\gamma$ amplitude based on a
phenomenological description of the decay mechanism in terms of dominant
intermediate states $\eta\gamma$, $\eta'\gamma$ and $f_1(1285)\gamma$. The
obtained value is of the order of the electromagnetic contribution.


title: Afterglow of the dynamical Schwinger process: soft photons amass

abstract:
  We consider the conversion of an electric field into photons as a secondary
probe of the dynamical Schwinger process. In spatially homogeneous electric
fields, quantum fluctuations of electron-positron ($e^+e^-$) pairs are lifted
on the mass shell leaving asymptotically a small finite pair density. The
$e^+e^-$ dynamics in turn couples to the quantized photon field and drives its
on-shell mode occupation. The spectral properties of the emerging asymptotic
photons accompanying the Schwinger process are calculated in lowest-order
perturbation theory. Soft photons in the optical range are produced amass in
the sub critical region, thus providing a promising discovery avenue, e.g. for
laser parameters of the Extreme Light Initiative (ELI-NP) to be put in
operation soon.


title:
The topological classification of one-dimensional symmetric quantum
  walks

abstract:
  We give a topological classification of quantum walks on an infinite 1D
lattice, which obey one of the discrete symmetry groups of the tenfold way,
have a gap around some eigenvalues at symmetry protected points, and satisfy a
mild locality condition. No translation invariance is assumed. The
classification is parameterized by three indices, taking values in a group,
which is either trivial, the group of integers, or the group of integers modulo
2, depending on the type of symmetry. The classification is complete in the
sense that two walks have the same indices if and only if they can be connected
by a norm continuous path along which all the mentioned properties remain
valid. Of the three indices, two are related to the asymptotic behaviour far to
the right and far to the left, respectively. These are also stable under
compact perturbations. The third index is sensitive to those compact
perturbations which cannot be contracted to a trivial one. The results apply to
the Hamiltonian case as well. In this case all compact perturbations can be
contracted, so the third index is not defined. Our classification extends the
one known in the translation invariant case, where the asymptotic right and
left indices add up to zero, and the third one vanishes, leaving effectively
only one independent index. When two translationally invariant bulks with
distinct indices are joined, the left and right asymptotic indices of the
joined walk are thereby fixed, and there must be eigenvalues at $1$ or $-1$
(bulk-boundary correspondence). Their location is governed by the third index.
We also discuss how the theory applies to finite lattices, with suitable
homogeneity assumptions.


title: On classification of non-unital simple amenable C*-algebras, I

abstract:
  We present a stable uniqueness theorem for non-unital C*-algebras.
Generalized tracial rank one is defined for stably projectionless simple
C*-algebras. Let $A$ and $B$ be two stably projectionless separable simple
amenable C*-algebras with $gTR(A)\le 1$and $gTR(B)\le 1.$ Suppose also that
$KK(A, D)=KK(B,D)=\{0\}$ for all C*-algebras $D.$ Then $A\cong B$ if and only
if they have the same tracial cones with scales. We also show that every
separable simple C*-algebra, $A$ with finite nuclear dimension which satisfies
the UCT with non-zero traces must have $gTR(A)\le 1$ if $K_0(A)$ is torsion. In
the next part of this research, we show similar results without the restriction
on $K$-theory.


title: Pion Polarizabilities from $\gamma\gamma\to\pi\pi$ Analysis

abstract:
  We present results for pion polarizabilities predicted using dispersion
relations from our earlier Amplitude Analysis of world data on two photon
production of meson pairs. The helicity-zero polarizabilities are rather stable
and insensitive to uncertainties in cross-channel exchanges. The need is first
to confirm the recent result on $(\alpha_1-\beta_1)$ for the charged pion by
COMPASS at CERN to an accuracy of 10\% by measuring the
$\gamma\gamma\to\pi^+\pi^-$ cross-section to an uncertainty of ~1\%. Then the
same polarizability, but for the $\pi^0$, is fixed to be
$(\alpha_1-\beta_1)_{\pi^0}=(-0.9\pm0.2)\times 10^{-4}$ fm$^{3}$. By analyzing
the correlation between uncertainties in the meson polarizability and those in
$\gamma\gamma$ cross-sections, we suggest experiments need to measure these
cross-sections between $\sqrt{s}\simeq 350$ and 600 MeV. The $\pi^0\pi^0$
cross-section then makes the $(\alpha_2-\beta_2)_{\pi^0}$ the easiest
helicity-two polarizability to determine.


title:
Topologically correct quantum nonadiabatic formalism for on-the-fly
  dynamics

abstract:
  On-the-fly quantum nonadiabatic dynamics for large systems greatly benefits
from the adiabatic representation readily available from the electronic
structure programs. However, frequently occurring in this representation
conical intersections introduce non-trivial geometric or Berry phases which
require a special treatment for adequate modelling of the nuclear dynamics. We
analyze two approaches for nonadiabatic dynamics using the time-dependent
variational principle and the adiabatic representation. The first approach
employs adiabatic electronic functions with global parametric dependence on the
nuclear coordinates. The second approach uses adiabatic electronic functions
obtained only at the centres of moving localized nuclear basis functions (e.g.
frozen-width Gaussians). Unless a gauge transformation is used to enforce
single-valued boundary conditions, the first approach fails to capture the
geometric phase. In contrast, the second approach accounts for the geometric
phase naturally because of the absence of the global nuclear coordinate
dependence in the electronic functions.


title: A study of conditional spreading sequences

abstract:
  It is shown that every conditional spreading sequence can be decomposed into
two well behaved parts, one being unconditional and the other being convex
block homogeneous, i.e. equivalent to its convex block sequences. This
decomposition is then used to prove several results concerning the structure of
spaces with conditional spreading bases as well as results in the theory of
conditional spreading models. Among other things, it is shown that the space
$C(\omega^\omega)$ is universal for all spreading models, i.e., it admits all
spreading sequences, both conditional and unconditional, as spreading models.
Moreover, every conditional spreading sequence is generated as a spreading
model by a sequence in a space that is quasi-reflexive of order one.


title:
Possibilistic semantics for a modal KD45 extension of G\"odel fuzzy
  logic

abstract:
  In this paper we provide a simplified semantics for the logic KD45(G), i.e.
the many-valued G\"odel counterpart of the classical modal logic KD45. More
precisely, we characterize KD45(G) as the set of valid formulae of the class of
possibilistic G\"odel Kripke Frames $\langle W,\pi \rangle$, where $W$ is a
non-empty set of worlds and $\pi: W \longrightarrow [0, 1]$ is a normalized
possibility distribution on $W$.


title: Relativistic electron wave packets carrying angular momentum

abstract:
  There are important differences between the nonrelativistic and relativistic
description of electron beams. The orbital angular momentum quantum number
cannot be used to specify the wave functions in the relativistic case. In this
Letter we introduce analytic solutions of the Dirac equation in the form of
exponential wave packets and we argue that they properly describe relativistic
electron beams carrying angular momentum.


title: Spectrum of a Rudin-Shapiro-like sequence

abstract:
  We show that a recently proposed Rudin-Shapiro-like sequence, with balanced
weights, has purely singular continuous diffraction spectrum, in contrast to
the well-known Rudin-Shapiro sequence whose diffraction is absolutely
continuous. This answers a question that had been raised about this new
sequence.


title: Nuclei and automorphism groups of generalized twisted Gabidulin codes

abstract:
  Generalized twisted Gabidulin codes are one of the few known families of
maximum rank matrix codes over finite fields. As a subset of m by n matrices,
when m=n, the automorphism group of any generalized twisted Gabidulin code has
been completely determined recently. In this paper, we consider the same
problem for m<n. Under certain conditions on their parameters, we determine
their middle nuclei and right nuclei, which are important invariants with
respect to the equivalence for rank metric codes. Furthermore, we also use them
to derive necessary conditions on the automorphisms of generalized twisted
Gabidulin codes.


title:
Designing, Building, Measuring and Testing a Constant Equivalent Fall
  Height Terrain Park Jump

abstract:
  Previous work has presented both a theoretical foundation for designing
terrain park jumps that control landing impact and computer software to
accomplish this task. US ski resorts have been reluctant to adopt this more
engineered approach to jump design, in part due to questions of feasibility.
The present study demonstrates this feasibility. It describes the design,
construction, measurement and experimental testing of such a jump. It improves
on previous efforts with more complete instrumentation, a larger range of jump
distances, and a new method for combining jumper- and board-mounted
accelerometer data to estimate equivalent fall height, a measure of impact
severity. It unequivocally demonstrates the efficacy of the engineering design
approach, namely that it is possible and practical to design and build free
style terrain park jumps with landing surface shapes that control for landing
impact as predicted by the theory.


title:
Twist decomposition of Drell-Yan structure functions: phenomenological
  implications

abstract:
  The forward Drell--Yan process in $pp$ scattering at the LHC at $\sqrt{S}=14$
TeV is considered. We analyze the Drell--Yan structure functions assuming the
dominance of a Compton-like emission of a virtual photon from a fast quark
scattering off the small $x$ gluons. The color dipole framework is applied to
perform quantitatively the twist decomposition of all the Drell--Yan structure
functions. Two models of the color dipole scattering are applied: the
Golec-Biernat--W\"{u}sthoff model and the dipole cross section obtained from
the Balitsky--Fadin--Kuraev--Lipatov evolution equation. The two models have
essentially different higher twist content and the gluon transverse momentum
distribution and lead to different significant effects beyond the collinear
leading twist description. It is found that the gluon transverse momentum
effects are significant in the Drell--Yan structure functions for all
Drell--Yan pair masses $M$, and the higher twist effects become important for
$M \lesssim 10$ GeV. It is found that the structure function $W_{TT}$ related
to the $A_2$ angular coefficient and the Lam--Tung observable $A_0 -A_2$ are
particularly sensitive to the gluon $k_T$ effects and to the higher twist
effects. A procedure is suggested how to disentangle the higher twist effects
from the gluon transverse momentum effects.


title:
SUSY model and dark matter determination in the compressed-spectrum
  region at the ILC

abstract:
  It is an appealing possibility that the observed dark matter density in the
universe can be fully explained by SUSY. The current experimental knowledge
indicates that this possibility strongly favors a co-annihilation scenario. In
such scenarios, the mass difference between the next-to-lightest SUSY particle
(the NLSP) and the lightest one (the LSP) is quite small, which assures that
the annihilation cross-section is sufficient not to predict a too large
abundance of dark matter. However, the small mass difference also means that
observing SUSY becomes hard at hadron colliders, where the observation hinges
on the tell-tale signature of missing transverse energy: if the mass difference
NLSP-to-LSP is small, only little energy is carried away by the invisible LSP.
This is also true even if several other SUSY particles are within the kinematic
reach, since these states would to a large extent decay via cascades ending
with an NLSP to LSP decay. A lepton collider does not have this problem. The
clean environment and known initial state at such machines assures that SUSY
can be detected even if the mass difference is very small, provided the
center-of-mass energy is sufficiently high. We present prospects for
observation and precision characterization of SUSY with small mass differences
at the ILC, based on detailed simulations of the ILD detector concept. The
resulting possibility to predict the dark matter relic density is evaluated and
compared to the precision obtained from the Planck mission. Taking a specific
model as an example, we also discuss the synergies from combining ILC and
HL-LHC results.


title:
The effect of electron holes on cyclotron maser emission driven by
  horseshoe distributions

abstract:
  This Brief Communication presents a quantitative investigation for the effect
of electron holes on electron-cyclotron maser (ECM) driven by horseshoe
distributions. The investigation is based on an integrated distribution
function for the horseshoe distributions with electron holes. Results show that
the presence of electron holes can significantly enhance the ECM growth rate by
2-3 times in a very narrow waveband. The present study suggests that these
electron holes probably are responsible for some fine structures of radiations,
such as narrowband events in auroral kilometric radiation and solar microwave
spikes.


title:
Explicit solutions of Laplace equations with inverse square and and
  singular P\"oschl-Teller Potentials

abstract:
  In this article we give in analytical closed form the solutions of the
Direchlet problems for the Laplace equations with inverse square and singular
P\"oschl-Teller potentials


title: Finitely stable racks and rack representations

abstract:
  We define a new class of racks, called finitely stable racks, which, to some
extent, share various flavors with Abelian groups. Characterization of finitely
stable Alexander quandles is established. Further, we study twisted rack
dynamical systems, construct their cross-products, and introduce representation
theory of racks and quandles. We prove several results on the {\em strong}
representations of finite connected involutive racks analogous to the
properties of finite Abelian groups. Finally, we define the {\em Pontryagin}
dual of a rack as an Abelian group which, in the finite involutive connected
case, coincides with the set of its strong irreducible representations.


title: Simple model on collisionless thin-shell instability growth

abstract:
  The manuscript discusses a simple model on the Thin Shell Instability (TSI)
growth phenomenon at early stage, by only imposing the fulfillment of
conservation laws; and in particular just applying the laws of mass and linear
momentum conservation, without taking into account the energy partitioning
inside the thin shell.


title: Columbia MVSO Image Sentiment Dataset

abstract:
  The Multilingual Visual Sentiment Ontology (MVSO) consists of 15,600 concepts
in 12 different languages that are strongly related to emotions and sentiments
expressed in images. These concepts are defined in the form of Adjective-Noun
Pair (ANP), which are crawled and discovered from online image forum Flickr. In
this work, we used Amazon Mechanical Turk as a crowd-sourcing platform to
collect human judgments on sentiments expressed in images that are uniformly
sampled over 3,911 English ANPs extracted from a tag-restricted subset of MVSO.
Our goal is to use the dataset as a benchmark for the evaluation of systems
that automatically predict sentiments in images or ANPs.


title:
TiO$_2$-based Memristors and ReRAM: Materials, Mechanisms and Models (a
  Review)

abstract:
  The memristor is the fundamental non-linear circuit element, with uses in
computing and computer memory. ReRAM (Resistive Random Access Memory) is a
resistive switching memory proposed as a non-volatile memory. In this review we
shall summarise the state of the art for these closely-related fields,
concentrating on titanium dioxide, the well-utilised and archetypal material
for both. We shall cover material properties, switching mechanisms and models
to demonstrate what ReRAM and memristor scientists can learn from each other
and examine the outlook for these technologies.


title:
Long term dynamics beyond Neptune: secular models to study the regular
  motions

abstract:
  Two semi-analytical one-degree-of-freedom secular models are presented for
the motion of small bodies beyond Neptune. A special attention is given to
trajectories entirely exterior to the planetary orbits. The first one is the
well-known non-resonant model of Kozai (1962) adapted to the transneptunian
region. Contrary to previous papers, the dynamics is fully characterized with
respect to the fixed parameters. A maximum perihelion excursion possible of
16.4 AU is determined. The second model handles the occurrence of a mean-motion
resonance with one of the planets. In that case, the one-degree-of-freedom
integrable approximation is obtained by postulating the adiabatic invariance,
and is much more general and accurate than previous secular models found in the
literature. It brings out in a plain way the possibility of perihelion
oscillations with a very high amplitude. Such a model could thus be used in
future studies to deeper explore that kind of motion. For complex resonant
orbits (especially of type 1:k), a segmented secular description is necessary
since the trajectories are only "integrable by parts". The two models are
applied to the Solar System but the notations are kept general so that it could
be used for any quasi-circular and coplanar planetary system.


title: On the splitting case of a semi-biplane construction

abstract:
  We consider the case where a particular incidence structure splits into two
substructures. The incidence structure in question was used previously by the
authors to construct semi-biplanes $sbp(k^2,k)$ or $sbp(k^2/2,k)$. A complete
description of the two substructures is obtained. We also show that none of the
three semi-biplanes, $sbp(18,6)$, can be described using this construction.


title: On the energisation of charged particles by fast magnetic reconnection

abstract:
  We study the role of turbulence in magnetic reconnection, within the
framework of magneto-hydrodynamics, using three-dimensional direct numerical
simulations. For small turbulent intensity we find that the reconnection rate
obeys Sweet-Parker scaling. For large enough turbulent intensity reconnection
rate departs significantly from Sweet-Parker behaviour, becomes almost a
constant as a function of the Lundquist number. We further study energisation
of test-particles in the same setup. We find that the speed of the energised
particles obeys a Maxwellian distribution, whose variance also obeys
Sweet-Parker scaling for small turbulent intensity but depends weakly on the
Lundquist number for large turbulent intensity. Furthermore, the variance is
found to increase with the strength of the reconnecting magnetic field.


title:
Predictive, finite-sample model choice for time series under
  stationarity and non-stationarity

abstract:
  In statistical research there usually exists a choice between structurally
simpler or more complex models. We argue that, even if a more complex, locally
stationary time series model were true, then a simple, stationary time series
model may be advantageous to work with under parameter uncertainty. We present
a new model choice methodology, where one of two competing approaches is chosen
based on its empirical, finite-sample performance with respect to prediction,
in a manner that ensures interpretability. A rigorous, theoretical analysis of
the procedure is provided. As an important side result we prove, for possibly
diverging model order, that the localised Yule-Walker estimator is strongly,
uniformly consistent under local stationarity. An R package, forecastSNSTS, is
provided and used to apply the methodology to financial and meteorological data
in empirical examples. We further provide an extensive simulation study and
discuss when it is preferable to base forecasts on the more volatile
time-varying estimates and when it is advantageous to forecast as if the data
were from a stationary process, even though they might not be.


title: On the Oscillations of Second Order Linear Differential Equations

abstract:
  This paper extends the discriminant associated to second order linear
constant coefficient differential equations to general second order linear
differential equations. The main result of this paper is that the discriminant
of a second order linear differential equation is a function who bounded
behaviour determines whether solutions oscillate on an infinite interval, i.e.
has infinitely many zeroes. This paper is accessible to any undergraduate who
has completed a course in differential equations, and basic analysis.


title: Ramanujan Sums as Derivatives

abstract:
  In 1918 S. Ramanujan defined a family of trigonometric sum now known as
Ramanujan sums. In the last few years, Ramanujan sums have inspired the signal
processing community. In this paper, we have defined an operator termed here as
Ramanujan operator. In this paper it has been proved that these operator
possesses properties of first derivative and second derivative with a
particular shift. Generalised multiplicative property and new method of
computing Ramanujan sums are also derived in terms of interpolation.


title:
On global attraction to stationary states for wave equations with
  concentrated nonlinearities

abstract:
  The global attraction to stationary states is established for solutions to 3D
wave equations with concentrated nonlinearities: each finite energy solution
converges as $t\to\pm\infty$ to stationary states. The attraction is caused by
nonlinear energy radiation.


title:
A non-strictly pseudoconvex domain for which the squeezing function
  tends to one towards the boundary

abstract:
  In recent work by Zimmer it was proved that if $\Omega\subset\mathbb C^n$ is
a bounded convex domain with $C^\infty$-smooth boundary, then $\Omega$ is
strictly pseudoconvex provided that the squeezing function approaches one as
one approaches the boundary. We show that this result fails if $\Omega$ is only
assumed to be $C^2$-smooth.


title:
Advancing Memristive Analog Neuromorphic Networks: Increasing
  Complexity, and Coping with Imperfect Hardware Components

abstract:
  We experimentally demonstrate classification of 4x4 binary images into 4
classes, using a 3-layer mixed-signal neuromorphic network ("MLP perceptron"),
based on two passive 20x20 memristive crossbar arrays, board-integrated with
discrete CMOS components. The network features 10 hidden-layer and 4
output-layer analog CMOS neurons and 428 metal-oxide memristors, i.e. is almost
an order of magnitude more complex than any previously reported functional
memristor circuit. Moreover, the inference operation of this classifier is
performed entirely in the integrated hardware. To deal with larger crossbar
arrays, we have developed a semi-automatic approach to their forming and
testing, and compared several memristor training schemes for coping with
imperfect behavior of these devices, as well as with variability of analog CMOS
neurons. The effectiveness of the proposed schemes for defect and variation
tolerance was verified experimentally using the implemented network and,
additionally, by modeling the operation of a larger network, with 300
hidden-layer neurons, on the MNIST benchmark. Finally, we propose a simple
modification of the implemented memristor-based vector-by-matrix multiplier to
allow its operation in a wider temperature range.


title: Multimode bolometer development for the PIXIE instrument

abstract:
  The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission
concept designed to measure the polarization and absolute intensity of the
cosmic microwave background. In the following, we report on the design,
fabrication, and performance of the multimode polarization-sensitive bolometers
for PIXIE, which are based on silicon thermistors. In particular we focus on
several recent advances in the detector design, including the implementation of
a scheme to greatly raise the frequencies of the internal vibrational modes of
the large-area, low-mass optical absorber structure consisting of a grid of
micromachined, ion-implanted silicon wires. With $\sim30$ times the absorbing
area of the spider-web bolometers used by Planck, the tensioning scheme enables
the PIXIE bolometers to be robust in the vibrational and acoustic environment
at launch of the space mission. More generally, it could be used to reduce
microphonic sensitivity in other types of low temperature detectors. We also
report on the performance of the PIXIE bolometers in a dark cryogenic
environment.


title:
Microfluidization of graphite and formulation of graphene-based
  conductive inks

abstract:
  We report the exfoliation of graphite in aqueous solutions under high shear
rate [$\sim10^8s^{-1}$] turbulent flow conditions, with a 100\% exfoliation
yield. The material is stabilized without centrifugation at concentrations up
to 100 g/L using carboxymethylcellulose sodium salt to formulate conductive
printable inks. The sheet resistance of blade coated films is
below$\sim2\Omega/\square$. This is a simple and scalable production route for
graphene-based conductive inks for large area printing in flexible electronics.


title: The Most Massive Active Galactic Nuclei at $1\lesssim z \lesssim 2$

abstract:
  We obtained near-infrared spectra of 26 SDSS quasars at $0.7<z<2.5$ with
reported rest-frame ultraviolet $M_{\rm BH} \sim 10^{10}M_{\odot}$ to
critically examine the systematic effects involved with their mass estimations.
We find that AGNs heavier than $10^{10}M_{\odot}$ often display double-peaked
H$\alpha$ emission, extremely broad FeII complex emission around MgII, and
highly blueshifted and broadened CIV emission. The weight of this evidence,
combined with previous studies, cautions against the use of $M_{\rm BH}$ values
based on any emission line with a width over 8000 km/s. Also, the $M_{\rm BH}$
estimations are not positively biased along the presence of ionized narrow line
outflows, anisotropic radiation, or the use of line FWHM instead of $\sigma$
for our sample, and unbiased with variability, scatter in broad line equivalent
width, or obscuration for general type-1 quasars. Removing the systematically
uncertain $M_{\rm BH}$ values, $\sim10^{10}M_{\odot}$ BHs in $1\lesssim z
\lesssim 2$ AGNs can still be explained by anisotropic motion of the broad line
region from $\sim10^{9.5}M_{\odot}$ BHs, although current observations support
they are intrinsically most massive, and overmassive to the host's bulge mass.


title:
Sizes and Kinematics of Extended Narrow-Line Regions in Luminous
  Obscured AGN Selected by Broadband Images

abstract:
  To study the impact of active galactic nuclei (AGN) feedback on the galactic
ISM, we present Magellan long-slit spectroscopy of 12 luminous nearby type 2
AGN (L_bol~10^{45.0-46.5} erg/s, z~0.1). These objects are selected from a
parent sample of spectroscopically identified AGN to have high
[OIII]{\lambda}5007 and WISE mid-IR luminosities and extended emission in the
SDSS r-band images, suggesting the presence of extended [OIII]{\lambda}5007
emission. We find spatially resolved [OIII] emission (2-35 kpc from the
nucleus) in 8 out of 12 of these objects. Combined with samples of higher
luminosity type 2 AGN, we confirm that the size of the narrow-line region
(R_NLR) scales with the mid-IR luminosity until the relation flattens at ~10
kpc. Nine out of 12 objects in our sample have regions with broad [OIII]
linewidths (w_80>600 km/s), indicating outflows. We define these regions as the
kinematically-disturbed region (KDR). The size of the KDR (R_KDR) is typically
smaller than R_NLR by few kpc but also correlates strongly with the AGN mid-IR
luminosity. Given the unknown density in the gas, we derive a wide range in the
energy efficiency {\eta}=dot{E}/L_bol=0.01%-30%. We find no evidence for an AGN
luminosity threshold below which outflows are not launched. To explain the
sizes, velocity profiles, and high occurrence rates of the outflows in the most
luminous AGN, we propose a scenario in which energy-conserving outflows are
driven by AGN episodes with ~10^8-year durations. Within each episode the AGN
flickers on shorter timescales, with a cadence of ~10^6 year active phases
separated by ~10^7 years.


title: On the weak separation limit of a two-component Bose-Einstein condensate

abstract:
  This paper deals with the study of the behaviour of the wave functions of a
two-component Bose-Einstein condensate in the case of weak segregation. This
amounts to the study of the asymptotic behaviour of a heteroclinic connection
in a conservative Hamiltonian system of two coupled second order ODE's, as the
strength of the coupling tends to its infimum. For this purpose, we apply
geometric singular perturbation theory.


title: Adiabatic Quantum Computing

abstract:
  Adiabatic quantum computing (AQC) started as an approach to solving
optimization problems, and has evolved into an important universal alternative
to the standard circuit model of quantum computing, with deep connections to
both classical and quantum complexity theory and condensed matter physics. In
this review we give an account of most of the major theoretical developments in
the field, while focusing on the closed-system setting. The review is organized
around a series of topics that are essential to an understanding of the
underlying principles of AQC, its algorithmic accomplishments and limitations,
and its scope in the more general setting of computational complexity theory.
We present several variants of the adiabatic theorem, the cornerstone of AQC,
and we give examples of explicit AQC algorithms that exhibit a quantum speedup.
We give an overview of several proofs of the universality of AQC and related
Hamiltonian quantum complexity theory. We finally devote considerable space to
Stoquastic AQC, the setting of most AQC work to date, where we discuss
obstructions to success and their possible resolutions.


title:
Effects of sterile neutrino and extra-dimension on big bang
  nucleosynthesis

abstract:
  By assuming the existence of extra-dimensional sterile neutrinos in big bang
nucleosynthesis (BBN) epoch, we investigate the sterile neutrino ($\nu_{\rm
s}$) effects on the BBN and constrain some parameters associated with the
$\nu_{\rm s}$ properties. First, for cosmic expansion rate, we take into
account effects of a five-dimensional bulk and intrinsic tension of the brane
embedded in the bulk, and constrain a key parameter of the extra dimension by
using the observational element abundances. Second, effects of the $\nu_{\rm
s}$ traveling on or off the brane are considered. In this model, the effective
mixing angle between a $\nu_{\rm s}$ and an active neutrino depends on energy,
which may give rise to a resonance effect on the mixing angle. Consequently,
reaction rate of the $\nu_{\rm s}$ can be drastically changed during the cosmic
evolution. We estimated abundances and temperature of the $\nu_{\rm s}$ by
solving the rate equation as a function of temperature until the sterile
neutrino decoupling. We then find that the relic abundance of the $\nu_{\rm s}$
is drastically enhanced by the extra-dimension and maximized for a
characteristic resonance energy $E_{\rm res}\gtrsim 0.01$ GeV. Finally, some
constraints related to the $\nu_{\rm s}$, mixing angle and mass difference, are
discussed in detail with the comparison of our BBN calculations corrected by
the extra-dimensional $\nu_{\rm s}$ to observational data on light element
abundances.


title:
Simultaneous detection and estimation of trait associations with genomic
  phenotypes

abstract:
  Genomic phenotypes, such as DNA methylation and chromatin accessibility, can
be used to characterize the transcriptional and regulatory activity of DNA
within a cell. Recent technological advances have made it possible to measure
such phenotypes very densely. This density often results in spatial structure,
in the sense that measurements at nearby sites are very similar.
  In this paper, we consider the task of comparing genomic phenotypes across
experimental conditions, cell types, or disease subgroups. We propose a new
method, Joint Adaptive Differential Estimation (JADE), which leverages the
spatial structure inherent to genomic phenotypes. JADE simultaneously estimates
smooth underlying group average genomic phenotype profiles, and detects regions
in which the average profile differs between groups. We evaluate JADE's
performance in several biologically plausible simulation settings. We also
consider an application to the detection of regions with differential
methylation between mature skeletal muscle cells, myotubes and myoblasts.


title:
Revisiting FPGA Acceleration of Molecular Dynamics Simulation with
  Dynamic Data Flow Behavior in High-Level Synthesis

abstract:
  Molecular dynamics (MD) simulation is one of the past decade's most important
tools for enabling biology scientists and researchers to explore human health
and diseases. However, due to the computation complexity of the MD algorithm,
it takes weeks or even months to simulate a comparatively simple biology entity
on conventional multicore processors. The critical path in molecular dynamics
simulations is the force calculation between particles inside the simulated
environment, which has abundant parallelism. Among various acceleration
platforms, FPGA is an attractive alternative because of its low power and high
energy efficiency. However, due to its high programming cost using RTL, none of
the mainstream MD software packages has yet adopted FPGA for acceleration.
  In this paper we revisit the FPGA acceleration of MD in high-level synthesis
(HLS) so as to provide affordable programming cost. Our experience with the MD
acceleration demonstrates that HLS optimizations such as loop pipelining,
module duplication and memory partitioning are essential to improve the
performance, achieving a speedup of 9.5X compared to a 12-core CPU. More
importantly, we observe that even the fully optimized HLS design can still be
2X slower than the reference RTL architecture due to the common dynamic
(conditional) data flow behavior that is not yet supported by current HLS
tools. To support such behavior, we further customize an array of processing
elements together with a data-driven streaming network through a common RTL
template, and fully automate the design flow. Our final experimental results
demonstrate a 19.4X performance speedup and 39X energy efficiency for the
widely used ApoA1 MD benchmark on the Convey HC1ex FPGA compared to a 12-core
Intel Xeon server.


title:
Variations between Dust and Gas in the Diffuse Interstellar Medium. 2.
  Search for Cold Gas

abstract:
  The content of interstellar clouds, in particular the inventory of diffuse
molecular gas, remains uncertain. We identified a sample of isolated clouds,
approximately 100 solar masses in size, and used the dust content to estimate
the total amount of gas. In Paper 1, the total inferred gas content was found
significantly larger than that seen in 21-cm emission measurements of atomic
hydrogen. In this paper we test the hypothesis that the apparent excess 'dark'
gas is cold atomic hydrogen, which would be evident in absorption but not in
emission due to line saturation. The results show there is not enough 21-cm
absorption toward the clouds to explain the total amount of 'dark' gas.


title:
Performance studies of D-meson tagged jets in pp collisions at
  $\sqrt{s}=7\,\mathrm{TeV}$ with ALICE

abstract:
  We present the current status of the measurement of jets that contain a D
meson (D-tagged jets) with ALICE. D-meson candidates, identified via their
hadronic decay channels, were combined with the other charged tracks
reconstructed with the central tracking system, using the anti-$k_{\rm T}$
jet-finding algorithm. The yield of D-tagged jets was extracted through an
invariant mass analysis of the D-meson candidates. A Monte Carlo simulation was
used to determine the detector performance and validate the signal extraction
techniques.


title: Control Synthesis for Bilevel Linear Model Predictive Control

abstract:
  Distributed model predictive control (MPC) is either cooperative or
competitive, and control-theoretic properties have been less studied in the
competitive (e.g., game theory) setting. This paper studies MPC with linear
dynamics and a Stackelberg game structure: Given a fixed lower-level linear MPC
(LoMPC) controller, the bilevel linear MPC (BiMPC) controller chooses inputs to
steer LoMPC knowing that LoMPC is optimizing with respect to a different cost
function. After defining LoMPC and BiMPC, we give examples to demonstrate how
interconnections in a dynamic Stackelberg game can lead to loss/gain (as
compared to the same system being centrally controlled) of controllability or
stability. Then, we give sufficient conditions under an arbitrary finite MPC
horizon for stabilizability of BiMPC, and develop an approach to synthesize a
stabilizing BiMPC controller. Next, we define two (a duality-based technique
and an integer-programming-based technique) reformulations to numerically solve
the optimization problem associated with BiMPC, prove equivalence of these
reformulations to BiMPC, and demonstrate their useful by simulations of a
synthetic system and a case study of an electric utility changing electricity
prices to perform demand response of a home's air conditioner controlled by a
linear MPC.


title: Lump Solutions to a Jimbo-Miwa Like Equations

abstract:
  A Jimbo-Miwa like nonlinear differential equation in (3+1)-dimensions is
developed through a generalized bilinear equation with the generalized bilinear
derivatives. Based on the generalized bilinear forms, two classes of lump
solutions, rationally localized in all directions in the space, and a class of
complex lump type solution are generated from a Maple search of quadratic
polynomial function solution to the proposed Jimbo-Miwa like equation. The
apposite conditions to assurance analyticity and rational localization of the
solutions are offered. Each of the resulting lump solutions hold six free
parameters, two of which are due to the translation invariance of the
Jimbo-Miwa like equations and four of which only require to satisfy the
presented apposite conditions of being lump solutions. We also generate circle
or ellipse shape solutions from the obtained solutions using different
conditions on the lumps solutions. Moreover, figures are given to visualize the
properties of the explicit solutions.


title: Giesbrecht's algorithm, the HFE cryptosystem and Ore's $p^s$-polynomials

abstract:
  We report on a recent implementation of Giesbrecht's algorithm for factoring
polynomials in a skew-polynomial ring. We also discuss the equivalence between
factoring polynomials in a skew-polynomial ring and decomposing
$p^s$-polynomials over a finite field, and how Giesbrecht's algorithm is
outlined in some detail by Ore in the 1930's. We end with some observations on
the security of the Hidden Field Equation (HFE) cryptosystem, where
$p$-polynomials play a central role.


title: Study and application of the resonant secular dynamics beyond Neptune

abstract:
  We use a secular representation to describe the long-term dynamics of
transneptunian objects in mean-motion resonance with Neptune. The model applied
is thoroughly described in Saillenfest et al. (2016). The parameter space is
systematically explored, showing that the secular trajectories depend little on
the resonance order. High-amplitude oscillations of the perihelion distance are
reported and localised in the space of the orbital parameters. In particular,
we show that a large perihelion distance is not a sufficient criterion to
declare that an object is detached from the planets. Such a mechanism, though,
is found unable to explain the orbits of Sedna or 2012VP113, which are
insufficiently inclined (considering their high perihelion distance) to be
possibly driven by such a resonant dynamics. The secular representation
highlights the existence of a high-perihelion accumulation zone due to
resonances of type 1:k with Neptune. That region is found to be located roughly
at semi-major axes in [100;300] AU, perihelion distances in [50;70] AU and
inclinations [30;50]{\deg}. In addition to the flux of objects directly coming
from the Scattered Disc, numerical simulations show that the Oort Cloud is also
a substantial source for such objects. Naturally, as that mechanism relies on
fragile captures in high-order resonances, our conclusions break down in the
case of a significant external perturber. The detection of such a reservoir
could thus be an observational constraint to probe the external Solar System.


title:
Can fully convolutional networks perform well for general image
  restoration problems?

abstract:
  We present a fully convolutional network(FCN) based approach for color image
restoration. FCNs have recently shown remarkable performance for high-level
vision problem like semantic segmentation. In this paper, we investigate if FCN
models can show promising performance for low-level problems like image
restoration as well. We propose a fully convolutional model, that learns a
direct end-to-end mapping between the corrupted images as input and the desired
clean images as output. Our proposed method takes inspiration from domain
transformation techniques but presents a data-driven task specific approach
where filters for novel basis projection, task dependent coefficient
alterations, and image reconstruction are represented as convolutional
networks. Experimental results show that our FCN model outperforms traditional
sparse coding based methods and demonstrates competitive performance compared
to the state-of-the-art methods for image denoising. We further show that our
proposed model can solve the difficult problem of blind image inpainting and
can produce reconstructed images of impressive visual quality.


title: Practical Secure Aggregation for Federated Learning on User-Held Data

abstract:
  Secure Aggregation protocols allow a collection of mutually distrust parties,
each holding a private value, to collaboratively compute the sum of those
values without revealing the values themselves. We consider training a deep
neural network in the Federated Learning model, using distributed stochastic
gradient descent across user-held training data on mobile devices, wherein
Secure Aggregation protects each user's model gradient. We design a novel,
communication-efficient Secure Aggregation protocol for high-dimensional data
that tolerates up to 1/3 users failing to complete the protocol. For 16-bit
input values, our protocol offers 1.73x communication expansion for $2^{10}$
users and $2^{20}$-dimensional vectors, and 1.98x expansion for $2^{14}$ users
and $2^{24}$ dimensional vectors.


title: Koszulity for skew PBW extensions over fields

abstract:
  Koszul and homogeneous Koszul algebras were defined by Priddy in
\cite{Priddy1970}. There exist some relations between these algebras and the
skew PBW extensions introduced in \cite{LezamaGallego}. In this paper we give
conditions to guarantee that skew PBW extensions over fields are Koszul or
homogeneous Koszul. We also show that a constant skew PBW extension of a field
is a PBW deformation of its homogeneous version.


title:
Local Structure of Gromov-Hausdorff Space near Finite Metric Spaces in
  General Position

abstract:
  We investigate the local structure of the space $\mathcal{M}$ consisting of
isometry classes of compact metric spaces, endowed with the Gromov-Hausdorff
metric. We consider finite metric spaces of the same cardinality and suppose
that these spaces are in general position, i.e., all nonzero distances in each
of the spaces are distinct, and all triangle inequalities are strict. We show
that sufficiently small balls in $\mathcal{M}$ centered at these spaces and
having the same radii are isometric. As consequences, we prove that the cones
over such spaces (with the vertices at one-point space) are isometrical; the
isometry group of each sufficiently small ball centered at a general position
$n$-points space, $n\ge3$, contains a subgroup isomorphic to the group $S_n$ of
permutations of a set containing $n$ points.


title:
Essential criteria for efficient pulse amplification via Raman and
  Brillouin scattering

abstract:
  Raman and Brillouin amplification are two schemes for amplifying and
compressing short laser pulses in plasma. Analytical models have already been
derived for both schemes, but the full consequences of these models are little
known or used. Here, we present new criteria that govern the evolution of the
attractor solution for the seed pulse in Raman and Brillouin amplification, and
show how the initial laser pulses need to be shaped to control the properties
of the final amplified seed and improve the amplification efficiency.


title: On centers of bimodule categories and induction-restriction functors

abstract:
  In this paper we study a toy categorical version of Lusztig's induction and
restriction functors for character sheaves, but in the abstract setting of
multifusion categories. Let $\mathscr{C}$ be an indecomposable multifusion
category and let $\mathscr{M}$ be an invertible $\mathscr{C}$-bimodule
category. Then the center $\mathscr{Z}_{\mathscr{C}}(\mathscr{M})$ of
$\mathscr{M}$ with respect to $\mathscr{C}$ is an invertible module category
over the Drinfeld center $\mathscr{Z}(\mathscr{C})$ which is a braided fusion
category. Let
$\zeta_{\mathscr{M}}:\mathscr{Z}_{\mathscr{C}}(\mathscr{M})\longrightarrow\mathscr{M}$
denote the forgetful functor and let
$\chi_{\mathscr{M}}:\mathscr{M}\longrightarrow\mathscr{Z}_{\mathscr{C}}(\mathscr{M})$
be its right adjoint functor. These functors can be considered as toy analogues
of the restriction and induction functors used by Lusztig to define character
sheaves on (possibly disconnected) reductive groups. In this paper we look at
the relationship between the decomposition of the images of the simple objects
under the above functors and the character tables of certain Grothendieck
rings. In case $\mathscr{C}$ is equipped with a spherical structure and
$\mathscr{M}$ is equipped with a $\mathscr{C}$-bimodule trace, we relate this
to the notion of the crossed S-matrix associated with the
$\mathscr{Z}(\mathscr{C})$-module category
$\mathscr{Z}_{\mathscr{C}}(\mathscr{M})$.


title:
Detecting kinematic boundary surfaces in phase space: particle mass
  measurements in SUSY-like events

abstract:
  We critically examine the classic endpoint method for particle mass
determination, focusing on difficult corners of parameter space, where some of
the measurements are not independent, while others are adversely affected by
the experimental resolution. In such scenarios, mass differences can be
measured relatively well, but the overall mass scale remains poorly
constrained. Using the example of the standard SUSY decay chain $\tilde q\to
\tilde\chi^0_2\to \tilde \ell \to \tilde \chi^0_1$, we demonstrate that
sensitivity to the remaining mass scale parameter can be recovered by measuring
the two-dimensional kinematical boundary in the relevant three-dimensional
phase space of invariant masses squared. We develop an algorithm for detecting
this boundary, which uses the geometric properties of the Voronoi tessellation
of the data, and in particular, the relative standard deviation (RSD) of the
volumes of the neighbors for each Voronoi cell in the tessellation. We propose
a new observable, $\bar\Sigma$, which is the average RSD per unit area,
calculated over the hypothesized boundary. We show that the location of the
$\bar\Sigma$ maximum correlates very well with the true values of the new
particle masses. Our approach represents the natural extension of the
one-dimensional kinematic endpoint method to the relevant three dimensions of
invariant mass phase space.


title:
Generative Models and Model Criticism via Optimized Maximum Mean
  Discrepancy

abstract:
  We propose a method to optimize the representation and distinguishability of
samples from two probability distributions, by maximizing the estimated power
of a statistical test based on the maximum mean discrepancy (MMD). This
optimized MMD is applied to the setting of unsupervised learning by generative
adversarial networks (GAN), in which a model attempts to generate realistic
samples, and a discriminator attempts to tell these apart from data samples. In
this context, the MMD may be used in two roles: first, as a discriminator,
either directly on the samples, or on features of the samples. Second, the MMD
can be used to evaluate the performance of a generative model, by testing the
model's samples against a reference data set. In the latter role, the optimized
MMD is particularly helpful, as it gives an interpretable indication of how the
model and data distributions differ, even in cases where individual model
samples are not easily distinguished either by eye or by classifier.


title:
Bijections for Weyl Chamber walks ending on an axis, using arc diagrams
  and Schnyder woods

abstract:
  In the study of lattice walks there are several examples of enumerative
equivalences which amount to a trade-off between domain and endpoint
constraints. We present a family of such bijections for simple walks in Weyl
chambers which use arc diagrams in a natural way. One consequence is a set of
new bijections for standard Young tableaux of bounded height. A modification of
the argument in two dimensions yields a bijection between Baxter permutations
and walks ending on an axis, answering a recent question of Burrill et al.
(2016). Some of our arguments (and related results) are proved using Schnyder
woods. Our strategy for simple walks extends to any dimension and yields a new
bijective connection between standard Young tableaux of height at most $2k$ and
certain walks with prescribed endpoints in the $k$-dimensional Weyl chamber of
type D.