title:
AMI observations of ten CLASH galaxy clusters: SZ and X-ray data used
  together to determine cluster dynamical states

abstract:
  Using Arcminute Microkelvin Imager (AMI) SZ observations towards ten CLASH
clusters we investigate the influence of cluster mergers on observational
galaxy cluster studies. Although selected to be largely relaxed, there is
disagreement in the literature on the dynamical states of CLASH sample members.
We analyse our AMI data in a fully Bayesian way to produce estimated cluster
parameters and consider the intrinsic correlations in our NFW/GNFW-based model.
Varying pressure profile shape parameters, illustrating an influence of mergers
on scaling relations, induces small deviations from the canonical self-similar
predictions -- in agreement with simulations of Poole et al. 2007 who found
that merger activity causes only small scatter perpendicular to the relations.
We demonstrate this effect observationally using the different dependencies of
SZ and X-ray signals to $n_{\rm e}$ that cause different sensitivities to the
shocking and/or fractionation produced by mergers. Plotting $Y_{\rm
X}$--$M_{\rm gas}$ relations (where $Y_{\rm X}=M_{\rm gas}T$) derived from AMI
SZ and from $Chandra$ X-ray gives ratios of AMI and $Chandra$ $Y_{\rm X}$ and
$M_{\rm gas}$ estimates that indicate movement of clusters \textit{along} the
scaling relation, as predicted by Poole et al. 2007. Clusters that have moved
most along the relation have the most discrepant $T_{\rm SZ}$ and $T_{\rm X}$
estimates: all the other clusters (apart from one) have SZ and X-ray estimates
of $M_{\rm gas}$, $T$ and $Y_{\rm X}$ that agree within $r_{500}$. We use SZ vs
X-ray discrepancies in conjunction with $Chandra$ maps and $T_{\rm X}$
profiles, making comparisons with simulated cluster merger maps in Poole et al.
2006, to identify disturbed members of our sample and estimate merger stages.


title: Evaluation of Zika Vector Control Strategies Using Agent-Based Modeling

abstract:
  Aedes Aegypti is the vector of several deadly diseases, including Zika.
Effective and sustainable vector control measures must be deployed to keep A.
aegypti numbers under control. The distribution of A. Aegypti is subject to
spatial and climatic constraints. Using agent-based modeling, we model the
population dynamics of A. aegypti subjected to the spatial and climatic
constraints of a neighborhood in the Key West. Satellite imagery was used to
identify vegetation, houses (CO2 zones) both critical to the mosquito
lifecycle. The model replicates the seasonal fluctuation of adult population
sampled through field studies and approximates the population at a high of 986
(95% CI: [979, 993]) females and 1031 (95% CI: [1024, 1039]) males in the fall
and a low of 316 (95% CI: [313, 319]) females and 333 (95% CI: [330, 336])
males during the winter. We then simulate two biological vector control
strategies: 1) Wolbachia infection and 2) Release of Insects carrying a
Dominant Lethal gene (RIDL). Our results support the probability of sustained
Wolbachia infection within the population for two years after the year of
release. egies, our approach provides a realistic simulation environment
consisting of male and female Aedes aegypti, breeding spots, vegetation and CO2
sources.


title:
Developing a project-based computational physics course grounded in
  expert practice

abstract:
  We describe a project-based computational physics course developed using a
backwards course design approach. From an initial competency-based model of
problem solving in computational physics, we interviewed faculty who use these
tools in their own research to determine indicators of expert practice. From
these, a rubric was formulated that enabled us to design a course intended to
allow students to learn these skills. We also report an initial implementation
of the course and, by having the interviewees regrade student work, show that
students acquired many of the expert practices identified.


title:
Do siblings always form and evolve simultaneously? Testing the coevality
  of multiple protostellar systems through SEDs

abstract:
  Multiplicity is common in field stars and among protostellar systems. Models
suggest two paths of formation: turbulent fragmentation and protostellar disk
fragmentation. We attempt to find whether or not the coevality frequency of
multiple protostellar systems can help to better understand their formation
mechanism. The coevality frequency is determined by constraining the relative
evolutionary stages of the components in a multiple system. SEDs for known
multiple protostars in Perseus were constructed from literature data. Herschel
PACS photometric maps were used to sample the peak of the SED for systems with
separations >7", a crucial aspect in determining the evolutionary stage of a
protostellar system. Inclination effects and the surrounding envelope and
outflows were considered to decouple source geometry from evolution. This
together with the shape and derived properties from the SED was used to
determine each system's coevality as accurately as possible. SED models were
used to examine the frequency of non-coevality that is due to geometry. We find
a non-coevality frequency of 33+/-10% from the comparison of SED shapes of
resolved multiple systems. Other source parameters suggest a somewhat lower
frequency of non-coevality. The frequency of apparent non-coevality that is due
to random inclination angle pairings of model SEDs is 17+/-0.5%. Observations
of the outflow of resolved multiple systems do not suggest significant
misalignments within multiple systems. Effects of unresolved multiples on the
SED shape are also investigated. We find that 1/3 of the multiple protostellar
systems sampled here are non-coeval, which is more than expected from random
geometric orientations. The other 2/3 are found to be coeval. Higher order
multiples show a tendency to be non-coeval. The frequency of non-coevality
found here is most likely due to formation and enhanced by dynamical evolution.


title: Pair correlation and twin primes revisited

abstract:
  We use the methods developed in our papers on moments and divisor
correlations to derive heuristically the conjectural ratios formula for two
zetas over two zetas.


title:
Collective coordinate quantization and spin statistics of the solitons
  in the $\mathbb{C}P^N$ Skyrme-Faddeev model

abstract:
  The $\mathbb{C}P^N$ extended Skyrme-Faddeev model possesses planar soliton
solutions. We consider quantum aspects of the solutions applying collective
coordinate quantization in regime of rigid body approximation. In order to
discuss statistical properties of the solutions we include an Abelian
Chern-Simons term (the Hopf term) in the Lagrangian. Since
$\Pi_3(\mathbb{C}P^1)=\mathbb{Z}$ then for $N=1$ the term becomes an integer.
On the other hand for $N>1$ it became perturbative because
$\Pi_3(\mathbb{C}P^N)$ is trivial. The prefactor of the Hopf term (anyon angle)
$\Theta$ is not quantized and its value depends on the physical system. The
corresponding fermionic models can fix value of the angle $\Theta$ for all $N$
in a way that the soliton with $N=1$ is not an anyon type whereas for $N>1$ it
is always an anyon even for $\Theta=n\pi, n\in \mathbb{Z}$. We quantize the
solutions and calculate several mass spectra for $N=2$. Finally we discuss
generalization for $N\geqq 3$.


title:
The porous medium equation on Riemannian manifolds with negative
  curvature. The large-time behaviour

abstract:
  We consider nonnegative solutions of the porous medium equation (PME) on a
Cartan-Hadamard manifold whose negative curvature can be unbounded. We take
compactly supported initial data because we are also interested in free
boundaries. We classify the geometrical cases we study into quasi-hyperbolic,
quasi-Euclidean and critical cases, depending on the growth rate of the
curvature at infinity. We prove sharp upper and lower bounds on the long-time
behaviour of the solutions in terms of corresponding bounds on the curvature.
In particular we obtain a sharp form of the smoothing effect on such manifolds.
We also estimate the location of the free boundary. A global Harnack principle
follows.
  We also present a change of variables that allows to transform radially
symmetric solutions of the PME on model manifolds into radially symmetric
solutions of a corresponding weighted PME on Euclidean space and back. This
equivalence turns out to be an important tool of the theory.


title: The HOMFLY Polynomial of Links in Closed Braid Form

abstract:
  It is well known that any link can be represented by the closure of a braid.
The minimum number of strings needed in a braid whose closure represents a
given link is called the braid index of the link and the well known
Morton-Frank-Williams inequality reveals a close relationship between the
HOMFLY polynomial of a link and its braid index. In the case that a link is
already presented in a closed braid form, Jaeger derived a special formulation
of the HOMFLY polynomial. In this paper, we prove a variant of Jaeger's result
as well as a dual version of it. Unlike Jaeger's original reasoning, which
relies on representation theory, our proof uses only elementary geometric and
combinatorial observations. Using our variant and its dual version, we provide
a direct and elementary proof of the fact that the braid index of a link that
has an $n$-string closed braid diagram that is also reduced and alternating, is
exactly $n$. Until know this fact was only known as a consequence of a result
due to Murasugi on fibered links that are star products of elementary torus
links and of the fact that alternating braids are fibered.


title: (Sub-)stellar variability: from 20 M$_{\odot}$ to 13 M$_{\rm Jup}$

abstract:
  Massive early-type stars vary; low-mass late-type brown dwarfs vary, too. I
will make a short, but illustrative, summary of my previous studies on stellar
and sub-stellar photometric variability (including the discovery of the most
variable brown dwarf in the whole sky), and explain how amateurs can help
professional astronomers with our investigations.


title: Global Albedos of Pluto and Charon from LORRI New Horizons Observations

abstract:
  The exploration of the Pluto-Charon system by the New Horizons spacecraft
represents the first opportunity to understand the distribution of albedo and
other photometric properties of the surfaces of objects in the Solar System's
"Third Zone" of distant ice-rich bodies. Images of the entire illuminated
surface of Pluto and Charon obtained by the Long Range Reconnaissance Imager
(LORRI) camera provide a global map of Pluto that reveals surface albedo
variegations larger than any other Solar System world except for Saturn's moon
Iapetus. Normal reflectances on Pluto range from 0.08-1.0, and the low-albedo
areas of Pluto are darker than any region of Charon. Charon exhibits a much
blander surface with normal reflectances ranging from 0.20-0.73. Pluto's albedo
features are well-correlated with geologic features, although some exogenous
low-albedo dust may be responsible for features seen to the west of the area
informally named Tombaugh Regio. The albedo patterns of both Pluto and Charon
are latitudinally organized, with the exception of Tombaugh Regio, with darker
regions concentrated at the Pluto's equator and Charon's northern pole The
phase curve of Pluto is similar to that of Triton, the large moon of Neptune
believed to be a captured Kuiper Belt Object (KBO), while Charon's is similar
to that of the Moon. Preliminary Bond albedos are 0.25+/-0.03 for Charon and
0.72+/-0.07 for Pluto. Maps of an approximation to the Bond albedo for both
Pluto and Charon are presented for the first time. Our work shows a connection
between very high albedo (near unity) and planetary activity, a result that
suggests the KBO Eris may be currently active.


title:
Accuracy of the geometric-mean method for determining spatial
  resolutions of tracking detectors in the presence of multiple Coulomb
  scattering

abstract:
  The geometric-mean method is often used to estimate the spatial resolution of
a position-sensitive detector probed by tracks. It calculates the resolution
solely from measured track data without using a detailed tracking simulation
and without considering multiple Coulomb scattering effects. Two separate
linear track fits are performed on the same data, one excluding and the other
including the hit from the probed detector. The geometric mean of the widths of
the corresponding exclusive and inclusive residual distributions for the probed
detector is then taken as a measure of the intrinsic spatial resolution of the
probed detector: $\sigma=\sqrt{\sigma_{ex}\cdot\sigma_{in}}$. The validity of
this method is examined for a range of resolutions with a stand-alone Geant4
Monte Carlo simulation that specifically takes multiple Coulomb scattering in
the tracking detector materials into account. Using simulated as well as actual
tracking data from a representative beam test scenario, we find that the
geometric-mean method gives systematically inaccurate spatial resolution
results. Good resolutions are estimated as poor and vice versa. The more the
resolutions of reference detectors and probed detector differ, the larger the
systematic bias. An attempt to correct this inaccuracy by statistically
subtracting multiple-scattering effects from geometric-mean results leads to
resolutions that are typically too optimistic by 10-50\%. This supports an
earlier critique of this method based on simulation studies that did not take
multiple scattering into account.


title: Amoeboid swimming in a channel

abstract:
  Several micro-organisms, such as bacteria, algae, or spermatozoa, use
flagella or cilia to swim in a fluid, while many other micro-organisms instead
use ample shape deformation, described as amoeboid, to propel themselves by
either crawling on a substrate or swimming. Many eukaryotic cells were believed
to require an underlying substratum to migrate (crawl) by using membrane
deformation (like blebbing or generation of lamellipodia) but there is now
increasing evidence that a large variety of cells (including those of the
immune system) can migrate without the assistance of focal adhesion, allowing
them to swim as efficiently as they can crawl. This paper details the analysis
of amoeboid swimming in a confined fluid by modeling the swimmer as an
inextensible membrane deploying local active forces. The swimmer displays a
rich behavior: it may settle into a straight trajectory in the channel or
navigate from one wall to the other depending on its confinement. The nature of
the swimmer is also found to be affected by confinement: the swimmer can
behave, on the average over one swimming cycle, as a pusher at low confinement,
and becomes a puller at higher confinement. The swimmer's nature is thus not an
intrinsic property. The scaling of the swimmer velocity V with the force
amplitude A is analyzed in detail showing that at small enough A, $V\sim
A^2/\eta^2$, whereas at large enough A, V is independent of the force and is
determined solely by the stroke frequency and swimmer size. This finding
starkly contrasts with currently known results found from swimming models where
motion is based on flagellar or ciliary activity, where $V\sim A/\eta$. To
conclude, two definitions of efficiency as put forward in the literature are
analyzed with distinct outcomes. We find that one type of efficiency has an
optimum as a function of confinement while the other does not. Future
perspectives are outlined.

categories: physics.bio-ph cond-mat.soft physics.comp-ph physics.flu-dyn q-bio.CB


title:
Optimal timing of cross-sectional network samples in longitudinal
  network studies

abstract:
  When choosing the timing of cross-sectional network snapshots in longitudinal
social network studies, the effect on the precision of parameter estimates
generally plays a minor role. Often the timing is opportunistic or determined
by a variety of considerations such as organizational constraints, funding, and
availability of study participants. Theory to guide the timing of network
snapshots is also missing. We use a statistical framework to relate the timing
to the precision of the parameter estimates, specifically, the sum of the
relative widths of their confidence intervals. We illustrate this
computationally using the STERGM suite of the statnet package to estimate the
parameters of the network dynamics. Analytically, we derive simple
approximations for the optimal timing when the parameters correspond to the
rates for different network events. We find that the optimal time depends the
most on the network processes with short expected durations and few expected
events such as the dissolution of ties. We apply our approximations to a simple
example of a dynamic network with formation and dissolution of iid ties.


title: Embedded all relevant feature selection with Random Ferns

abstract:
  Many machine learning methods can produce variable importance scores
expressing the usability of each feature in context of the produced model;
those scores on their own are yet not sufficient to generate feature selection,
especially when an all relevant selection is required. Although there are
wrapper methods aiming to solve this problem, they introduce a substantial
increase in the required computational effort.
  In this paper I investigate an idea of incorporating all relevant selection
within the training process by producing importance for implicitly generated
shadows, attributes irrelevant by design. I propose and evaluate such a method
in context of random ferns classifier. Experiment results confirm the
effectiveness of such approach, although show that fully stochastic nature of
random ferns limits its applicability either to small dimensions or as a part
of a broader feature selection procedure.


title: Circumstellar and explosion properties of Type Ibn supernovae

abstract:
  We investigate circumstellar and explosion properties of Type Ibn supernovae
(SNe) by analyzing their bolometric light curves. Bolometric light curves of
Type Ibn SNe generally have a large contrast between peak luminosity and
late-phase luminosity, which is much larger than those of 56Ni-powered SNe.
Thus, most of them are likely powered by the interaction between SN ejecta and
dense circumstellar media. In addition, Type Ibn SNe decline much faster than
Type IIn SNe, and this indicates that the interaction in Type Ibn SNe ceases
earlier than in Type IIn SNe. Thus, we argue that Type Ibn SN progenitors
experience high mass-loss rates in a short period just before explosion, while
Type IIn SN progenitors have high mass-loss rates sustained for a long time.
Furthermore, we show that rise time and peak luminosity of Type Ibn and Type
IIn SNe are similar and thus, they have similar explosion properties and
circumstellar density. The similar circumstellar density in the two kinds of
SNe may indicate that mass-loss rates of Type Ibn SN progenitors are generally
higher than those of Type IIn as the wind velocities inferred from narrow
spectral components are generally higher in Type Ibn SNe. We also show that
56Ni mass and explosion energy of Type Ibn SNe may be smaller than those of
other stripped-envelope SNe, probably because they tend to suffer large
fallback or some of them may not even be terminal stellar explosions.


title:
Stability for the Complete Intersection Theorem, and the Forbidden
  Intersection Problem of Erd\H{o}s and S\'os

abstract:
  A family $F$ of sets is said to be $t$-intersecting if $|A \cap B| \geq t$
for any $A,B \in F$. The seminal Complete Intersection Theorem of Ahlswede and
Khachatrian (1997) gives the maximal size $f(n,k,t)$ of a $t$-intersecting
family of $k$-element subsets of $[n]=\{1,2,\ldots,n\}$, together with a
characterisation of the extremal families.
  The forbidden intersection problem, posed by Erd\H{o}s and S\'{o}s in 1971,
asks for a determination of the maximal size $g(n,k,t)$ of a family $F$ of
$k$-element subsets of $[n]$ such that $|A \cap B| \neq t-1$ for any $A,B \in
F$.
  In this paper, we show that for any fixed $t \in \mathbb{N}$, if $o(n) \leq k
\leq n/2-o(n)$, then $g(n,k,t)=f(n,k,t)$. In combination with prior results,
this solves the above problem of Erd\H{o}s and S\'{o}s for any constant $t$,
except for in the ranges $n/2-o(n) < k < n/2+t/2$ and $k < 2t$.
  One key ingredient of the proof is the following sharp `stability' result for
the Complete Intersection Theorem: if $k/n$ is bounded away from $0$ and $1/2$,
and $F$ is a $t$-intersecting family of $k$-element subsets of $[n]$ such that
$|F| \geq f(n,k,t) - O(\binom{n-d}{k})$, then there exists a family $G$ such
that $G$ is extremal for the Complete Intersection Theorem, and $|F \setminus
G| = O(\binom{n-d}{k-d})$. We believe this result to be of interest in its own
right; indeed, it proves a conjecture of Friedgut from 2008. We prove it by
combining classical `shifting' arguments with a `bootstrapping' method based
upon an isoperimetric inequality.
  Another key ingredient is a `weak regularity lemma' for families of
$k$-element subsets of $[n]$, where $k/n$ is bounded away from 0 and 1. This
states that any such family $F$ is approximately contained within a `junta',
such that the restriction of $F$ to each subcube determined by the junta is
`pseudorandom' in a certain sense.


title:
On the torsion group of elliptic curves induced by Diophantine triples
  over quadratic fields

abstract:
  The possible torsion groups of elliptic curves induced by Diophantine triples
over quadratic fields, which do not appear over Q, are Z/2Z x Z/10Z, Z/2Z x
Z/12Z and Z/4Z x Z/4Z. In this paper, we show that all these torsion groups
indeed appear over some quadratic field. Moreover, we prove that there are
infinitely many Diophantine triples over quadratic fields which induce elliptic
curves with these torsion groups.


title: Feet in Orthogonal-Buekenhout-Metz Unitals

abstract:
  Given an Orthogonal-Buekenhout-Metz unital $U_{\alpha,\beta}$, embedded in
$PG(2,q^2)$, and a point $P\notin U_{\alpha,\beta}$, we study the set of feet,
$\tau_{P}(U_{\alpha,\beta})$, of $P$ in $U_{\alpha,\beta}$. We characterize
geometrically each of these sets as either $q+1$ collinear points or as $q+1$
points partitioned into two arcs. Other results about the geometry of these
sets are also given.


title: Host Galaxy Identification for Supernova Surveys

abstract:
  Host galaxy identification is a crucial step for modern supernova (SN)
surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey
Telescope (LSST), which will discover SNe by the thousands. Spectroscopic
resources are limited, so in the absence of real-time SN spectra these surveys
must rely on host galaxy spectra to obtain accurate redshifts for the Hubble
diagram and to improve photometric classification of SNe. In addition, SN
luminosities are known to correlate with host-galaxy properties. Therefore,
reliable identification of host galaxies is essential for cosmology and SN
science. We simulate SN events and their locations within their host galaxies
to develop and test methods for matching SNe to their hosts. We use both real
and simulated galaxy catalog data from the Advanced Camera for Surveys General
Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe
residing in undetected faint hosts into our analysis, with an assumed hostless
rate of 5%. Our fully automated algorithm is run on catalog data and matches
SNe to their hosts with 91% accuracy. We find that including a machine learning
component, run after the initial matching algorithm, improves the accuracy
(purity) of the matching to 97% with a 2% cost in efficiency (true positive
rate). Although the exact results are dependent on the details of the survey
and the galaxy catalogs used, the method of identifying host galaxies we
outline here can be applied to any transient survey.


title: Notes on Lynch-Morawska Systems

abstract:
  In this paper we investigate convergent term rewriting systems that conform
to the criteria set out by Christopher Lynch and Barbara Morawska in their
seminal paper "Basic Syntactic Mutation." The equational unification problem
modulo such a rewrite system is solvable in polynomial-time. In this paper, we
derive properties of such a system which we call an $LM$-system. We show, in
particular, that the rewrite rules in an $LM$-system have no left- or
right-overlaps. We also show that despite the restricted nature of an
$LM$-system, there are important undecidable problems, such as the deduction
problem in cryptographic protocol analysis (also called the the cap problem)
that remain undecidable for $LM$-systems.


title:
Detection of Potential Transit Signals in 17 Quarters of Kepler Data:
  Results of the Final Kepler Mission Transiting Planet Search (DR25)

abstract:
  We present results of the final Kepler Data Processing Pipeline search for
transiting planet signals in the full 17-quarter primary mission data set. The
search includes a total of 198,709 stellar targets, of which 112,046 were
observed in all 17 quarters and 86,663 in fewer than 17 quarters. We report on
17,230 targets for which at least one transit signature is identified that
meets the specified detection criteria: periodicity, minimum of three observed
transit events, detection statistic (i.e., signal-to-noise ratio) in excess of
the search threshold, and passing grade on three statistical transit
consistency tests. Light curves for which a transit signal is identified are
iteratively searched for additional signatures after a limb-darkened transiting
planet model is fitted to the data and transit events are removed. The search
for additional planets adds 16,802 transit signals for a total of 34,032; this
far exceeds the number of transit signatures identified in prior pipeline runs.
There was a strategic emphasis on completeness over reliability for the final
Kepler transit search. A comparison of the transit signals against a set of
3402 well-established, high-quality Kepler Objects of Interest yields a
recovery rate of 99.8%. The high recovery rate must be weighed against a large
number of false-alarm detections. We examine characteristics of the planet
population implied by the transiting planet model fits with an emphasis on
detections that would represent small planets orbiting in the habitable zone of
their host stars.


title: 2-hereditary algebras and almost Fano weighted surfaces

abstract:
  Tilting bundles $\mathcal{T}$ on a weighted projective line $\mathbb{X}$ have
been intensively studied by representation theorists since they give rise to a
derived equivalence between $\mathbb{X}$ and the finite dimensional algebra End
$\mathcal{T}$. A classical result states that if End $\mathcal{T}$ is
hereditary, then $\mathbb{X}$ is Fano and conversely, for every Fano weighted
projective line, there exists a tilting bundle $\mathcal{T}$ with End
$\mathcal{T}$ hereditary. In this paper, we examine the question of when a
weighted projective surface has a tilting bundle whose endomorphism ring is
2-hereditary in the sense of Herschend-Iyama-Oppermann. It is natural to
conjecture that they are the almost Fano weighted surfaces, weighted only on
rational curves, and we give evidence to support this.


title:
On the mixed $(\ell _{1},\ell _{2})$-Littlewood inequalities and
  interpolation

abstract:
  It is well-known that the optimal constant of the bilinear Bohnenblust--Hille
inequality (i.e., Littlewood's $4/3$ inequality) is obtained by interpolating
the bilinear mixed $\left( \ell _{1},\ell_{2}\right) $-Littlewood inequalities.
We remark that this cannot be extended to the $3$-linear case and, in the
opposite direction, we show that the asymptotic growth of the constants of the
$m$-linear Bohnenblust--Hille inequality is the same of the constants of the
mixed $\left( \ell _{\frac{2m+2}{m+2}},\ell _{2}\right) $-Littlewood
inequality. This means that, contrary to what the previous works seem to
suggest, interpolation does not play a crucial role in the search of the exact
asymptotic growth of the constants of the Bohnenblust--Hille inequality. In the
final section we use mixed Littlewood type inequalities to obtain the optimal
cotype constants of certain sequence spaces.


title:
Location-Based Beamforming and Physical Layer Security in Rician Wiretap
  Channels

abstract:
  We propose a new location-based beamforming (LBB) scheme for wiretap
channels, where a multi-antenna source communicates with a single-antenna
legitimate receiver in the presence of a multi-antenna eavesdropper. We assume
that all channels are in a Rician fading environment, the channel state
information from the legitimate receiver is perfectly known at the source, and
that the only information on the eavesdropper available at the source is her
location. We first describe how the optimal beamforming vector that minimizes
the secrecy outage probability of the system is obtained, illustrating its
dependence on the eavesdropper's location. We then derive an easy-to-compute
expression for the secrecy outage probability when our proposed LBB scheme is
adopted. We also consider the positive impact a friendly jammer can have on our
beamforming solution, showing how the path to optimality remains the same.
Finally, we investigate the impact of location uncertainty on the secrecy
outage probability, showing how our solution can still allow for secrecy even
when the source only has a noisy estimate of the eavesdropper's location. Our
work demonstrates how a multi-antenna array, operating in the most general
channel conditions and most likely system set-up, can be configured rapidly in
the field so as to deliver an optimal physical layer security solution.


title:
Service Rate, Busy Period & Throughput Analysis of a Horizontal Traffic
  Queue

abstract:
  We consider a horizontal traffic queue (HTQ) on a periodic road segment,
where vehicles arrive according to a spatio-temporal Poisson process, and
depart after traveling a distance that is sampled independently and identically
from a spatial distribution. When inside the queue, the speed of a vehicle is
proportional to a power $m >0$ of the distance to the vehicle in front. The
service rate of HTQ is equal to the sum of the speeds of the vehicles, and has
a complex dependency on the state (vehicle locations) of the system. We show
that the service-rate increases (resp., decreases) in between arrivals and
departures for $m<1$ (resp., $m>1$) case. For a given initial condition, we
define the throughput of such a queue as the largest arrival rate under which
the queue length remains bounded. We extend the busy period calculations for
M/G/1 queue to our setting, including for non-empty initial condition. These
calculations are used to prove that the throughput for $m=1$ case is equal to
the inverse of the time required to travel average total distance by a solitary
vehicle in the system, and also to derive a probabilistic upper bound on the
queue length over a finite time horizon for the $m>1$ case. Finally, we study
throughput under a release control policy, where the additional expected
waiting time caused by the control policy is interpreted as the magnitude of
the perturbation to the arrival process. We derive a lower bound on throughput
for a given combination of maximum allowable perturbation, for $m<1$ and $m>1$
cases. In particular, if the allowable perturbation is sufficiently large, then
this lower bound grows unbounded as $m \to 0^+$. Illustrative simulation
results are also presented.


title:
Estimating Semi-parametric Panel Multinomial Choice Models using Cyclic
  Monotonicity

abstract:
  This paper proposes a new semi-parametric identification and estimation
approach to multinomial choice models in a panel data setting with individual
fixed effects. Our approach is based on cyclic monotonicity, which is a
defining feature of the random utility framework underlying multinomial choice
models. From the cyclic monotonicity property, we derive identifying
inequalities without requiring any shape restrictions for the distribution of
the random utility shocks. These inequalities point identify model parameters
under straightforward assumptions on the covariates. We propose a consistent
estimator based on these inequalities.


title:
Recovering $U(n)$-invariant toric K\"ahler metrics on
  $\mathbb{C}\mathbb{P}^n$ from the torus equivariant spectrum

abstract:
  In this note we prove that toric K\"ahler metrics on complex projective space
which are also $U(n)$-invariant are determined by their equivariant spectrum
i.e. the list of eigenvalues of the Laplacian together with weights of the
torus representation on the eigenspaces.


title: Electrochemical kinetics and dimensional considerations at the nanoscale

abstract:
  It is shown that the consideration of the density of states variation in
nanoscale electrochemical systems yields modulations in the rate constant and
concomitant electrical currents. The proposed models extend the utility of
Marcus-Hush-Chidsey (MHC) kinetics to a larger class of materials and could be
used as a test of dimensional character. The implications of the study are of
much significance to an understanding and modulation of charge transfer
nanostructured electrodes.


title: Disordered Contact Networks in Jammed Packings of Frictionless Disks

abstract:
  We analyse properties of contact networks formed in packings of soft
frictionless disks near the unjamming transition. We construct polygonal
tilings and triangulations of the contact network that partitions space into
convex regions which are either covered or uncovered. This allows us to
characterize the local spatial structure of the packing near the transition
using well-defined geometric objects. We construct bounds on the number of
polygons and triangulation vectors that appear in such packings. We study these
networks using simulations of bidispersed disks interacting via a one-sided
linear spring potential. We find that several underlying geometric
distributions are reproducible and display self averaging properties. We find
that the total covered area is a reliable real space parameter that can serve
as a substitute for the packing fraction. We find that the unjamming transition
occurs at a fraction of covered area $A_G^{*} = 0.446(1)$. We determine scaling
exponents of the excess covered area as the energy of the system approaches
zero $E_G \to 0^+$, and the coordination number $\langle z_g \rangle$
approaches its isostatic value $\Delta Z = \langle z_g \rangle - \langle z_g
\rangle_{\rm iso} \to 0^{+}$. We find $\Delta A_G \sim \Delta {E_G}^{0.28(1)}$
and $\Delta A_G \sim \Delta Z^{1.00(1)}$, representing new structural critical
exponents. We use the distribution functions of local areas to study the
underlying geometric disorder in the packings. We find that a finite fraction
of order $\Psi_O^* = 0.369(1)$ persists as the transition is approached.


title:
Manifestation of a non-abelian gauge field in a p-type semiconductor
  system

abstract:
  Gauge theories, while describing fundamental interactions in nature, also
emerge in a wide variety of physical systems. Abelian gauge fields have been
predicted and observed in a number of novel quantum many-body systems,
topological insulators, ultracold atoms and many others. However, the
non-abelian gauge field, while playing the most fundamental role in particle
physics, up to now has remained a purely theoretical construction in many-body
physics. In the present paper we report the first observation of a non-abelian
gauge field in a spin-orbit coupled quantum system. The gauge field manifests
itself in quantum magnetic oscillations of a hole doped two-dimensional (2D)
GaAs heterostructure. Transport measurements were performed in tilted magnetic
fields, where the effect of the emergent non-abelian gauge field was controlled
by the components of the magnetic field in the 2D plane.


title: Curvature estimates for immersed hypersurfaces in Riemannian manifolds

abstract:
  We establish mean curvature estimate for immersed hypersurface with
nonnegative extrinsic scalar curvature in Riemannian manifold $(N^{n+1}, \bar
g)$ through regularity study of a degenerate fully nonlinear curvature equation
in general Riemannian manifold. The estimate has a direct consequence for the
Weyl isometric embedding problem of $(\mathbb S^2, g)$ in $3$-dimensional
warped product space $(N^3, \bar g)$. We also discuss isometric embedding
problem in spaces with horizon in general relativity, like the Anti-de
Sitter-Schwarzschild manifolds and the Reissner-Nordstr\"om manifolds.


title: Enhancing Multiuser MIMO Through Opportunistic D2D Cooperation

abstract:
  We propose a cellular architecture that combines multiuser MIMO (MU-MIMO)
downlink with opportunistic use of unlicensed ISM bands to establish
device-to-device (D2D) cooperation. The architecture consists of a
physical-layer cooperation scheme based on forming downlink virtual MIMO
channels through D2D relaying, and a novel resource allocation strategy for
such D2D-enabled networks. We prove the approximate optimality of the
physical-layer scheme, and demonstrate that such cooperation boosts the
effective SNR of the weakest user in the system, especially in the many-user
regime, due to multiuser diversity. To harness this physical-layer scheme, we
formulate the cooperative user scheduling and relay selection problem using the
network utility maximization framework. For such a cooperative network, we
propose a novel utility metric that jointly captures fairness in throughput and
the cost of relaying in the system. We propose a joint user scheduling and
relay selection algorithm, which we prove to be asymptotically optimal. We
study the architecture through system-level simulations over a wide range of
scenarios. The highlight of these simulations is an approximately $6$x
improvement in data rate for cell-edge (bottom fifth-percentile) users (over
the state-of-the-art SU-MIMO) while still improving the overall throughput, and
taking into account various system constraints.


title: Permanental random variables, ${M}$-matrices and $\alpha$-permanents

abstract:
  We explore some properties of a recent representation of permanental vectors
which expresses them as sums of independent vectors with components that are
independent gamma random variables.


title: Nonextensive information theoretical machine

abstract:
  In this paper, we propose a new discriminative model named \emph{nonextensive
information theoretical machine (NITM)} based on nonextensive generalization of
Shannon information theory. In NITM, weight parameters are treated as random
variables. Tsallis divergence is used to regularize the distribution of weight
parameters and maximum unnormalized Tsallis entropy distribution is used to
evaluate fitting effect. On the one hand, it is showed that some well-known
margin-based loss functions such as $\ell_{0/1}$ loss, hinge loss, squared
hinge loss and exponential loss can be unified by unnormalized Tsallis entropy.
On the other hand, Gaussian prior regularization is generalized to Student-t
prior regularization with similar computational complexity. The model can be
solved efficiently by gradient-based convex optimization and its performance is
illustrated on standard datasets.


title:
Deep Adaptive Network: An Efficient Deep Neural Network with Sparse
  Binary Connections

abstract:
  Deep neural networks are state-of-the-art models for understanding the
content of images, video and raw input data. However, implementing a deep
neural network in embedded systems is a challenging task, because a typical
deep neural network, such as a Deep Belief Network using 128x128 images as
input, could exhaust Giga bytes of memory and result in bandwidth and computing
bottleneck. To address this challenge, this paper presents a hardware-oriented
deep learning algorithm, named as the Deep Adaptive Network, which attempts to
exploit the sparsity in the neural connections. The proposed method adaptively
reduces the weights associated with negligible features to zero, leading to
sparse feedforward network architecture. Furthermore, since the small
proportion of important weights are significantly larger than zero, they can be
robustly thresholded and represented using single-bit integers (-1 and +1),
leading to implementations of deep neural networks with sparse and binary
connections. Our experiments showed that, for the application of recognizing
MNIST handwritten digits, the features extracted by a two-layer Deep Adaptive
Network with about 25% reserved important connections achieved 97.2%
classification accuracy, which was almost the same with the standard Deep
Belief Network (97.3%). Furthermore, for efficient hardware implementations,
the sparse-and-binary-weighted deep neural network could save about 99.3%
memory and 99.9% computation units without significant loss of classification
accuracy for pattern recognition applications.


title: Cube invariance of higher Chow groups with modulus

abstract:
  The higher Chow group with modulus was introduced by Binda-Saito as a common
generalization of Bloch's higher Chow group and the additive higher Chow group.
In this paper, we study invariance properties of the higher Chow group with
modulus. First, we formulate and prove "cube invariance," which generalizes
$\mathbb{A}^1$-homotopy invariance of Bloch's higher Chow group. Next, we
introduce the nilpotent higher Chow group with modulus, as an analogue of the
nilpotent algebraic $K$-group, and define a module structure on it over the big
Witt ring of the base field. We deduce from the module structure that the
higher Chow group with modulus with appropriate coefficients satisfies
$\mathbb{A}^1$-homotopy invariance. We also prove that $\mathbb{A}^1$-homotopy
invariance implies independence from the multiplicity of the modulus divisors.


title:
Classifications and canonical forms of tensor product expressions in the
  presence of permutation symmetries

abstract:
  Complicated mathematical equations involving products of tensors with
permutation symmetries, frequently encountered in fields such as general
relativity and quantum chemistry (e.g., equations in high-order coupled cluster
theories), require computer-based automatic derivations and manipulations. In
these processes, a key step is the collection of tensor product terms that can
be found identical by utilizing permutation symmetries of tensors or relabeling
dummy indices, which is usually achieved by defining a canonical form for
tensor product expressions. However, the problem of finding a canonical form is
nontrivial, and can be potentially of exponential cost in the number of
indices. In this work, we provided a general solution to this tensor
canonicalization problem.


title: An Intuitive Tangible Game Controller

abstract:
  This paper outlines the development of a sensory feedback device providing a
tangible interface for controlling digital environments, in this example a
flight simulator, where the intention for the device is that it is relatively
low cost, versatile and intuitive. Gesture based input allows for a more
immersive experience, so rather than making the user feel like they are
controlling an aircraft the intuitive interface allows the user to become the
aircraft that is controlled by the movements of the user's hand. The movements
are designed to allow a sense of immersion that would be difficult to achieve
with an alternative interface. A vibrotactile based haptic feedback is
incorporated in the device to further enhance the connection between the user
and the game environment by providing immediate confirmation of game events.
When used for navigating an aircraft simulator, this device invites playful
action and thrill. It bridges new territory on portable, low cost solutions for
haptic devices in gaming contexts.


title: Augmented Body: Changing Interactive Body Play

abstract:
  This paper investigates the player's body as a system capable of unfamiliar
interactive movement achieved through digital mediation in a playful
environment. Body interactions in both digital and non-digital environments can
be considered as a perceptually manipulative exploration of self. This implies
a player may alter how they perceive their body and its operations in order to
create a new playful and original experience. This paper therefore questions
how player interaction can change as their perception of their body changes
using augmentative technology.


title: Social Play Spaces for Active Community Engagement

abstract:
  This paper puts forward the perspective that social play spaces are
opportunities to utilise both technology and body for the benefit of community
culture and engagement. Co-located social gaming coupled with tangible
interfaces offer active participant engagement and the development of the local
video game scene. This paper includes a descriptive account of Rabble Room
Arcade, an experimental social event combining custom-built physical interface
devices and multiplayer video games.


title:
Miniature optical planar camera based on a wide-angle metasurface
  doublet corrected for monochromatic aberrations

abstract:
  Optical metasurfaces are two-dimensional arrays of nano-scatterers that
modify optical wavefronts at subwavelength spatial resolution. They are poised
to revolutionize optics by enabling complex low-cost systems where multiple
metasurfaces are lithographically stacked and integrated with electronics. For
imaging applications, metasurface stacks can perform sophisticated image
corrections and can be directly integrated with image sensors. Here, we
demonstrate this concept with a miniature flat camera integrating a monolithic
metasurface lens doublet corrected for monochromatic aberrations, and an image
sensor. The doublet lens, which acts as a fisheye photographic objective, has a
small $f$-number of 0.9, an angle-of-view larger than
60$^\circ\times$60$^\circ$, and operates at 850 nm wavelength with 70% focusing
efficiency. The camera exhibits nearly diffraction-limited image quality, which
indicates the potential of this technology in the development of optical
systems for microscopy, photography, and computer vision.


title:
Production of Neutral and Doubly Charged Partners of D_{s0}^+(2317)
  Revisited

abstract:
  Rates for productions of neutral and doubly charged partners of
D_{s0}^+(2317) in B meson decays are studied by using a hard D meson
approximation in the infinite momentum frame, and the results are of the same
order of magnitude as that of D_{s0}^+(2317). Because the bottom-strange
X^{+-}(5568) which can be interpreted as iso-triplet bottom partners of
D_{s0}^+(2317) have recently been discovered, observations of neutral and
doubly charged partners of D_{s0}^+(2317) are strongly desired.


title:
The Extended Littlestone's Dimension for Learning with Mistakes and
  Abstentions

abstract:
  This paper studies classification with an abstention option in the online
setting. In this setting, examples arrive sequentially, the learner is given a
hypothesis class $\mathcal H$, and the goal of the learner is to either predict
a label on each example or abstain, while ensuring that it does not make more
than a pre-specified number of mistakes when it does predict a label.
  Previous work on this problem has left open two main challenges. First, not
much is known about the optimality of algorithms, and in particular, about what
an optimal algorithmic strategy is for any individual hypothesis class. Second,
while the realizable case has been studied, the more realistic non-realizable
scenario is not well-understood. In this paper, we address both challenges.
First, we provide a novel measure, called the Extended Littlestone's Dimension,
which captures the number of abstentions needed to ensure a certain number of
mistakes. Second, we explore the non-realizable case, and provide upper and
lower bounds on the number of abstentions required by an algorithm to guarantee
a specified number of mistakes.


title:
Topological steps toward the Homflypt skein module of the lens spaces
  $L(p,1)$ via braids

abstract:
  In this paper we work toward the Homflypt skein module of the lens spaces
$L(p,1)$, $\mathcal{S}(L(p,1))$, using braids. In particular, we establish the
connection between $\mathcal{S}({\rm ST})$, the Homflypt skein module of the
solid torus ST, and $\mathcal{S}(L(p,1))$ and arrive at an infinite system,
whose solution corresponds to the computation of $\mathcal{S}(L(p,1))$. We
start from the Lambropoulou invariant $X$ for knots and links in ST, the
universal analogue of the Homflypt polynomial in ST, and a new basis,
$\Lambda$, of $\mathcal{S}({\rm ST})$ presented in \cite{DL1}. We show that
$\mathcal{S}(L(p,1))$ is obtained from $\mathcal{S}({\rm ST})$ by considering
relations coming from the performance of braid band moves (bbm) on elements in
the basis $\Lambda$, where the braid band moves are performed on any moving
strand of each element in $\Lambda$. We do that by proving that the system of
equations obtained from diagrams in ST by performing bbm on any moving strand
is equivalent to the system obtained if we only consider elements in the basic
set $\Lambda$.
  The importance of our approach is that it can shed light to the problem of
computing skein modules of arbitrary c.c.o. $3$-manifolds, since any
$3$-manifold can be obtained by surgery on $S^3$ along unknotted closed curves.
The main difficulty of the problem lies in selecting from the infinitum of band
moves some basic ones and solving the infinite system of equations.


title:
Outage Probability Analysis of Amplify-and-Forward Cooperative Diversity
  Relay Networks

abstract:
  The statistical analysis of the fading End to End channel gain of the amplify
and forward relaying protocol, however, is well known as extremely complex, and
research work to date have only studied the asymptotic behaviour of the outage
probability of the network at either very low or very high Signal Noise Ratios.
Most current works circumvent the analytical complexity by first ignoring the
effect of Additive White Gaussian noise then by using the simple approximated
upper bound for the Signal Noise Ratio. The new approximated upper bound
proposed in this paper, is far better bound than the previous results for the
entire Signal Noise Ratio, which allows us to derive exact analytical
expressions to study the effect of Additive White Gaussian noise on the network
performance.


title:
Zodiacal Exoplanets in Time (ZEIT) III: A short-period planet orbiting a
  pre-main-sequence star in the Upper Scorpius OB Association

abstract:
  We confirm and characterize a close-in ($P_{\rm{orb}}$ = 5.425 days),
super-Neptune sized ($5.04^{+0.34}_{-0.37}$ Earth radii) planet transiting
K2-33 (2MASS J16101473-1919095), a late-type (M3) pre-main sequence (11
Myr-old) star in the Upper Scorpius subgroup of the Scorpius-Centaurus OB
association. The host star has the kinematics of a member of the Upper Scorpius
OB association, and its spectrum contains lithium absorption, an unambiguous
sign of youth (<20 Myr) in late-type dwarfs. We combine photometry from K2 and
the ground-based MEarth project to refine the planet's properties and constrain
the host star's density. We determine \name's bolometric flux and effective
temperature from moderate resolution spectra. By utilizing isochrones that
include the effects of magnetic fields, we derive a precise radius (6-7%) and
mass (16%) for the host star, and a stellar age consistent with the established
value for Upper Scorpius. Follow-up high-resolution imaging and Doppler
spectroscopy confirm that the transiting object is not a stellar companion or a
background eclipsing binary blended with the target. The shape of the transit,
the constancy of the transit depth and periodicity over 1.5 years, and the
independence with wavelength rules out stellar variability, or a dust cloud or
debris disk partially occulting the star as the source of the signal; we
conclude it must instead be planetary in origin. The existence of K2-33b
suggests close-in planets can form in situ or migrate within $\sim 10$ Myr,
e.g., via interactions with a disk, and that long-timescale dynamical migration
such as by Lidov-Kozai or planet-planet scattering is not responsible for all
short-period planets.


title:
Bounding quantification in parametric expansions of Presburger
  arithmetic

abstract:
  We generalize Cooper's method of quantifier elimination for classical
Presburger arithmetic to give a new proof that all parametric Presburger
families (as defined by Kevin Woods) are definable by formulas with
polynomially bounded quantifiers in an expanded language with predicates for
divisibility by f(t) for every polynomial f over the integers. In fact, this
quantifier bounding method works more generally in expansions of Presburger
arithmetic with multiplication by scalars from any ring of functions into Z.


title: Testing the Quantal Response Hypothesis

abstract:
  This paper develops a non-parametric test for consistency of players'
behavior in a series of games with the Quantal Response Equilibrium (QRE). The
test exploits a characterization of the equilibrium choice probabilities in any
structural QRE as the gradient of a convex function, which thus satisfies the
cyclic monotonicity inequalities. Our testing procedure utilizes recent
econometric results for moment inequality models. We assess our test using lab
experimental data from a series of generalized matching pennies games. We
reject the QRE hypothesis in the pooled data, but it cannot be rejected in the
individual data for over half of the subjects.


title:
Dynamics of dissipative solitons in a high repetition rate
  normal-dispersion erbium-doped fiber laser

abstract:
  The dynamics of dissipative solitons (DSs) are explored in a high repetition
rate normal-dispersion erbium-doped fiber laser for the first time. Despite of
the high fundamental repetition rate of 129 MHz and thus the low pulse energy,
a DS train with a dechirped pulse width of 418 fs, period-doubling of single
and dual DSs, as well as 258 MHz 2nd-order harmonic mode-locking of DSs can be
observed in the fiber laser with increasing pump power and appropriate
settings. A transmitted semiconductor saturable absorber and a wavelength
division multiplexer/isolator/tap hybrid module are employed to simplify the
laser configuration, thus not only increasing the repetition rate, but also
enhancing the stability and robustness of the fiber laser due to the commercial
availability of all the components.


title: A Database for Storing the Results of Material Radiopurity Measurements

abstract:
  Searches for rare nuclear processes, such as neutrinoless double beta-decay
and the interactions of WIMP dark matter, are motivating experiments with
ever-decreasing levels of radioactive backgrounds. These background reductions
are achieved using various techniques, but amongst the most important is
minimizing radioactive contamination in the materials from which the experiment
is constructed. To this end there have been decades of advances in material
sourcing, manufacture and certification, during which researchers have
accumulated many thousands of measurements of material radiopurity. Some of
these assays are described in publications, others are in databases, but many
are still communicated informally. Until this work, there has been no standard
format for encoding assay results and no effective, central location for
storing them. The aim of this work is to address these long-standing problems
by creating a concise and flexible material assay data format and powerful
software application to manipulate it. A public installation of this software,
available at http://www.radiopurity.org, is the largest database of assay
results ever compiled and is intended as a long-term repository for the
community's data.


title: Adjusted Empirical Likelihood for Long-memory Time Series Models

abstract:
  Empirical likelihood method has been applied to short-memory time series
models by Monti (1997) through the Whittle's estimation method. Yau (2012)
extended this idea to long-memory time series models. Asymptotic distributions
of the empirical likelihood ratio statistic for short and long-memory time
series have been derived to construct confidence regions for the corresponding
model parameters. However, computing profile empirical likelihood function
involving constrained maximization does not always have a solution which leads
to several drawbacks. In this paper, we propose an adjusted empirical
likelihood procedure to modify the one proposed by Yau (2012) for
autoregressive fractionally integrated moving average (ARFIMA) model. It
guarantees the existence of a solution to the required maximization problem as
well as maintains same asymptotic properties obtained by Yau (2012).
Simulations have been carried out to illustrate that the adjusted empirical
likelihood method for different long-time series models provides better
confidence regions and coverage probabilities than the unadjusted ones,
especially for small sample sizes.


title:
High-Order Extended Finite Element Methods for Solving Interface
  Problems

abstract:
  In this paper, we study arbitrary order extended finite element (XFE) methods
based on two discontinuous Galerkin (DG) schemes in order to solve elliptic
interface problems in two and three dimensions. Optimal error estimates in the
piecewise $H^1$-norm and in the $L^2$-norm are rigorously proved for both
schemes. In particular, we have devised a new parameter-friendly DG-XFEM
method, which means that no "sufficiently large" parameters are needed to
ensure the optimal convergence of the scheme. To prove the stability of
bilinear forms, we derive non-standard trace and inverse inequalities for
high-order polynomials on curved sub-elements divided by the interface. All the
estimates are independent of the location of the interface relative to the
meshes. Numerical examples are given to support the theoretical results.


title:
New Bounds for Partial Spreads of $H(2d-1, q^2)$ and Partial Ovoids of
  the Ree-Tits Octagon

abstract:
  Two results are obtained that give upper bounds on partial spreads and
partial ovoids respectively.
  The first result is that the size of a partial spread of the Hermitian polar
space $\mathsf{H}(3, q^2)$ is at most $\left(\frac{2p^3+p}{3} \right)^t+1$,
where $q=p^t$, $p$ is a prime. For fixed $p$ this bound is in $o(q^3)$, which
is asymptotically better than the previous best known bound of $(q^3+q+2)/2$.
Similar bounds for partial spreads of $\mathsf{H}(2d-1, q^2)$, $d$ even, are
given.
  The second result is that the size of a partial ovoid of the Ree-Tits octagon
$\mathsf{O}(2^t)$ is at most $26^t+1$. This bound, in particular, shows that
the Ree-Tits octagon $\mathsf{O}(2^t)$ does not have an ovoid.


title: Onset of Plasticity in Thin Polystyrene Films

abstract:
  Polymer glasses have numerous advantageous mechanical properties in
comparison to other materials. One of the most useful is the high degree of
toughness that can be achieved due to significant yield occurring in the
material. Remarkably, the onset of plasticity in polymeric materials is very
poorly quantified, despite its importance as the ultimate limit of purely
elastic behavior. Here we report the results of a novel experiment which is
extremely sensitive to the onset of yield and discuss its impact on measurement
and elastic theory. In particular, we use an elastic instability to locally
bend and impart a \textit{local} tensile stress in a thin, glassy polystyrene
film, and directly measure the resulting residual stress caused by the bending.
We show that plastic failure is initiated at extremely low strains, of order
$10^{-3}$ for polystyrene. Not only is this critical strain found to be small
in comparison to bulk measurement, we show that it is influenced by thin film
confinement - leading to an increase in the critical strain for plastic failure
as film thickness approaches zero.


title: Training Deep Nets with Sublinear Memory Cost

abstract:
  We propose a systematic approach to reduce the memory consumption of deep
neural network training. Specifically, we design an algorithm that costs
O(sqrt(n)) memory to train a n layer network, with only the computational cost
of an extra forward pass per mini-batch. As many of the state-of-the-art models
hit the upper bound of the GPU memory, our algorithm allows deeper and more
complex models to be explored, and helps advance the innovations in deep
learning research. We focus on reducing the memory cost to store the
intermediate feature maps and gradients during training. Computation graph
analysis is used for automatic in-place operation and memory sharing
optimizations. We show that it is possible to trade computation for memory -
giving a more memory efficient training algorithm with a little extra
computation cost. In the extreme case, our analysis also shows that the memory
consumption can be reduced to O(log n) with as little as O(n log n) extra cost
for forward computation. Our experiments show that we can reduce the memory
cost of a 1,000-layer deep residual network from 48G to 7G with only 30 percent
additional running time cost on ImageNet problems. Similarly, significant
memory cost reduction is observed in training complex recurrent neural networks
on very long sequences.


title:
Universal Fluctuations of Single-Particle Diffusivity in Quenched
  Environment

abstract:
  Local diffusion coefficients in disordered materials such as living cells are
highly heterogeneous. Quenched disorder is utilized substantially to study such
complex systems, whereas its analytical treatment is difficult to handle. We
consider finite systems with quenched disorder in order to investigate the
effects of sample disorder fluctuations and confinement on single-particle
diffusivity. While the system is ergodic in a single disorder realization, the
time-averaged mean squared displacement depends on the disorder, i.e., the
system is ergodic but non-self-averaging. We find that the inverse Levy
distribution is a universal distribution for diffusivity in the sense that it
can be applied for arbitrary dimensions. Quantifying the degree of the
non-self-averaging effect, we show that fluctuations of single-particle
diffusivity far exceed the corresponding annealed theory and also find
confinement effects. The relevance for experimental situations is also
discussed.


title: Tropical Embeddings of Metric Graphs

abstract:
  Every graph $\Gamma$ can be embedded in the plane with a minimal number of
edge intersections, called its classical crossing number
$\text{cross}\left(\Gamma\right)$. In this paper, we prove that if $\Gamma$ is
a metric graph it can be realized as a tropical curve in the plane with exactly
$\text{cross}\left(\Gamma\right)$ crossings, where the tropical curve is
equipped with the lattice length metric. Our result has an application in
algebraic geometry, as it enables us to construct a rational map of
non-Archimedean curves into the projective plane, whose tropicalization is
almost faithful when restricted to their skeleton.


title: Non-contractible periodic orbits in Hamiltonian dynamics on tori

abstract:
  We show that the presence of one non-degenerate, non-contractible periodic
orbit of a Hamiltonian on the standard symplectic torus implies the existence
of infinitely many simple non-contractible periodic orbits.


title: Continuous extension of functions from countable sets

abstract:
  We give a characterization of countable discrete subspace $A$ of a
topological space $X$ such that there exists a (linear) continuous mapping
$\varphi:C_p^*(A)\to C_p(X)$ with $\varphi(y)|_A=y$ for every $y\in C_p^*(A)$.
Using this characterization we answer two questions of A.~Arhangel'skii.
Moreover, we introduce the notion of well-covered subset of a topological space
and prove that for well-covered functionally closed subset $A$ of a topological
space $X$ there exists a linear continuous mapping $\varphi:C_p(A)\to C_p(X)$
with $\varphi(y)|_A=y$ for every $y\in C_p(A)$.


title:
Piezoelectric electromechanical coupling in nanomechanical resonators
  with two-dimensional electron gas

abstract:
  The electrical response of two-dimensional electron gas to vibrations of a
nanomechanical cantilever containing it is studied. Vibrations of
perpendicularly oriented cantilevers are experimentally shown to change
oppositely the conductivity near their bases. This indicates the piezoelectric
nature of electromechanical coupling. A physical model is developed, which
quantitatively explains the experiment. It shows that the main origin of the
conductivity change is a rapid change in the mechanical stress on the boundary
between suspended and non-suspended areas, rather than the stress itself.


title:
Explaining the 750 GeV diphoton excess with a colored scalar charged
  under a new confining gauge interaction

abstract:
  We consider a charged scalar particle $\chi$ of mass around 375 GeV charged
under both $SU(3)_c$ and a new confining non-abelian gauge interaction. After
pair production, these interactions confine the exotic scalar into
non-relativistic bound states whose decays into photons can explain the 750 GeV
diphoton excess observed at the LHC. Taking the new confining group to be
$\mathrm{SU}(2)$, we find $\chi$ must carry an electric charge of $Q \sim
[\frac{1}{2}, 1]$ to fit the data. Interestingly, we find that pair production
of the scalars and the subsequent formation of the bound state dominates over
direct bound state resonance production. This explanation is quite weakly
constrained by current searches and data from the forthcoming run at the LHC
will be able to probe our scenario more fully. In particular dijet, mono-jet,
di-Higgs and jet + photon searches may be the most promising discovery
channels.


title:
Approximation Algorithm for Fault-Tolerant Virtual Backbone in Wireless
  Sensor Networks

abstract:
  To save energy and alleviate interferences in a wireless sensor network, the
usage of virtual backbone was proposed. Because of accidental damages or energy
depletion, it is desirable to construct a fault tolerant virtual backbone,
which can be modeled as a $k$-connected $m$-fold dominating set (abbreviated as
$(k,m)$-CDS) in a graph. A node set $C\subseteq V(G)$ is a $(k,m)$-CDS of graph
$G$ if every node in $V(G)\backslash C$ is adjacent with at least $m$ nodes in
$C$ and the subgraph of $G$ induced by $C$ is $k$-connected. In this paper, we
present an approximation algorithm for the minimum $(3,m)$-CDS problem with
$m\geq3$. The performance ratio is at most $\gamma$, where
$\gamma=\alpha+8+2\ln(2\alpha-6)$ for $\alpha\geq4$ and $\gamma=3\alpha+2\ln2$
for $\alpha<4$, and $\alpha$ is the performance ratio for the minimum
$(2,m)$-CDS problem. Using currently best known value of $\alpha$, the
performance ratio is $\ln\delta+o(\ln\delta)$, where $\delta$ is the maximum
degree of the graph, which is asymptotically best possible in view of the
non-approximability of the problem. This is the first performance-guaranteed
algorithm for the minimum $(3,m)$-CDS problem on a general graph. Furthermore,
applying our algorithm on a unit disk graph which models a homogeneous wireless
sensor network, the performance ratio is less than 27, improving previous ratio
62.3 by a large amount for the $(3,m)$-CDS problem on a unit disk graph.


title: The THUMOS Challenge on Action Recognition for Videos "in the Wild"

abstract:
  Automatically recognizing and localizing wide ranges of human actions has
crucial importance for video understanding. Towards this goal, the THUMOS
challenge was introduced in 2013 to serve as a benchmark for action
recognition. Until then, video action recognition, including THUMOS challenge,
had focused primarily on the classification of pre-segmented (i.e., trimmed)
videos, which is an artificial task. In THUMOS 2014, we elevated action
recognition to a more practical level by introducing temporally untrimmed
videos. These also include `background videos' which share similar scenes and
backgrounds as action videos, but are devoid of the specific actions. The three
editions of the challenge organized in 2013--2015 have made THUMOS a common
benchmark for action classification and detection and the annual challenge is
widely attended by teams from around the world.
  In this paper we describe the THUMOS benchmark in detail and give an overview
of data collection and annotation procedures. We present the evaluation
protocols used to quantify results in the two THUMOS tasks of action
classification and temporal detection. We also present results of submissions
to the THUMOS 2015 challenge and review the participating approaches.
Additionally, we include a comprehensive empirical study evaluating the
differences in action recognition between trimmed and untrimmed videos, and how
well methods trained on trimmed videos generalize to untrimmed videos. We
conclude by proposing several directions and improvements for future THUMOS
challenges.


title:
The most elementary heat to work conversion: work extraction from a
  completely passive state by a single photon

abstract:
  The concepts of work and heat in the quantum domain, as well as their
interconversion principles, are still an open debate. We have found theoretical
evidence that a single photon packet is capable of extracting work from a
single two-level system (TLS). More importantly, this effect is found for a
photon as it is spontaneously emitted, therefore carrying only heat away from
the emitter. This is the most elementary process in which heat is converted
into work, requiring not more than two off-resonance atoms for that purpose.
From a more practical point of view it is found that, surprisingly, work can be
extracted from a TLS in a completely passive initial state. The process is
cyclic in the sense that the TLS initial and final states are equal. The state
of the TLS remains passive throughout the interaction time with the
single-photon packet. The physical meaning of the work performed by the TLS is
found to be a dynamical change in the color of the photon during the reemission
process. All our predictions are, in principle, measurable within
state-of-the-art experiments.


title: Gauge interactions and topological phases of matter

abstract:
  We initiate the study of the effects of strongly-coupled gauge interactions
on the properties of the topological phases of matter. In particular, we
discuss fermionic systems with three spatial dimensions, protected by time
reversal symmetry. We first derive a sufficient condition for the introduction
of a dynamical Yang-Mills field to preserve the topological phase of matter,
and then show how the massless pions capture in the infrared the topological
properties of the fermions in the ultraviolet. Finally, we use the S-duality of
${\mathcal N}=2$ supersymmetric $SU(2)$ gauge theory with $N_f{=}4$ flavors to
show that the $\nu{=}16$ phase of Majorana fermions can be continuously
connected to the trivial $\nu{=}0$ phase.


title: The Dual Standard Model and the 750 GeV Events at the LHC

abstract:
  The aim of this short paper is to discuss the recently observed excess at 750
GeV by both CMS and ATLAS in the light of the dual standard model. Within this
framework it is natural to introduce neutral spin 0 and/or spin 2 $SU(2)$ glue
mesons which could easily account for this observation if it is confirmed. The
model predicts that these glue mesons would be part of $SU(2)$ triplets and
that there must thus be charged counterparts of these glue mesons carrying a
QED charge of $\pm 1$ with a spin 0 and/or 2 as well.


title:
Induced low-energy effective action in the 6D, N=(1,0) hypermultiplet
  theory on the vector multiplet background

abstract:
  We consider the six dimensional N=(1,0) hypermultiplet model coupled to an
external field of the Abelian vector multiplet in harmonic superspace approach.
Using the superfield proper-time technique we find the divergent part of the
effective action and derive the complete finite induced low-energy superfield
effective action. This effective action depends on external field and contains
in bosonic sector all the powers of the constant Maxwell field strength. The
obtained result can be treated as the 6D, N=(1,0) supersymmetric
Heisenberg-Euler type effective action.


title:
Evolutionary Image Transition Based on Theoretical Insights of Random
  Processes

abstract:
  Evolutionary algorithms have been widely studied from a theoretical
perspective. In particular, the area of runtime analysis has contributed
significantly to a theoretical understanding and provided insights into the
working behaviour of these algorithms. We study how these insights into
evolutionary processes can be used for evolutionary art. We introduce the
notion of evolutionary image transition which transfers a given starting image
into a target image through an evolutionary process. Combining standard
mutation effects known from the optimization of the classical benchmark
function OneMax and different variants of random walks, we present ways of
performing evolutionary image transition with different artistic effects.


title:
Multiple complex-valued solutions for nonlinear magnetic Schrodinger
  equations

abstract:
  We study, in the semiclassical limit, the singularly perturbed nonlinear
Schr\"odinger equations $$ L^{\hbar}_{A,V} u = f(|u|^2)u \quad \mbox{in } R^N
$$ where $N \geq 3$, $L^{\hbar}_{A,V}$ is the Schr\"odinger operator with a
magnetic field having source in a $C^1$ vector potential $A$ and a scalar
continuous (electric) potential $V$ defined by \begin{equation}
L^{\hbar}_{A,V}= -\hbar^2 \Delta-\frac{2\hbar}{i} A \cdot \nabla + |A|^2-
\frac{\hbar}{i}\operatorname{div}A + V(x). \end{equation} Here $f$ is a
nonlinear term which satisfies the so-called Berestycki-Lions conditions. We
assume that there exists a bounded domain $\Omega \subset R^N$ such that \[ m_0
\equiv \inf_{x \in \Omega} V(x) < \inf_{x \in \partial \Omega} V(x) \] and we
set $K = \{ x \in \Omega \ | \ V(x) = m_0\}$. For $\hbar >0$ small we prove the
existence of at least $cuplenght(K) + 1$ geometrically distinct, complex-valued
solutions whose modula concentrate around $K$ as $\hbar \to 0$.


title:
Herschel observed Stripe 82 quasars and their host galaxies: connections
  between the AGN activity and the host galaxy star formation

abstract:
  In this work, we present a study of 207 quasars selected from the Sloan
Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars
within this sample are high luminosity quasars with a mean bolometric
luminosity of $10^{46.4}$ erg s$^{-1}$. The redshift range of this sample is
within $z<4$, with a mean value of $1.5\pm0.78$. Because we only selected
quasars that have been detected in all three Herschel-SPIRE bands, the quasar
sample is complete yet highly biased. Based on the multi-wavelength photometric
observation data, we conducted a spectral energy distribution (SED) fitting
through UV to FIR. Parameters such as active galactic nucleus (AGN) luminosity,
FIR luminosity, stellar mass, as well as many other AGN and galaxy properties
are deduced from the SED fitting results. The mean star formation rate (SFR) of
the sample is 419 $M_{\odot}$ yr$^{-1}$ and the mean gas mass is $\sim
10^{11.3}$ $M_{\odot}$. All these results point to an IR luminous quasar
system. Comparing with star formation main sequence (MS) galaxies, at least 80
out of 207 quasars are hosted by starburst galaxies. It supports the statement
that luminous AGNs are more likely to be associated with major mergers. The SFR
increases with the redshift up to $z=2$. It is correlated with the AGN
bolometric luminosity, where $L_{\rm FIR} \propto L_{\rm Bol}^{0.46\pm0.03}$.
The AGN bolometric luminosity is also correlated with the host galaxy mass and
gas mass. Yet the correlation between $L_{\rm FIR}$ and $L_{\rm Bol}$ has
higher significant level, implies that the link between AGN accretion and the
SFR is more primal. The $M_{\rm BH}/M_{\ast}$ ratio of our sample is 0.02,
higher than the value 0.005 in the local Universe. It might indicate an
evolutionary trend of the $M_{\rm BH} - M_{\ast}$ scaling relation.


title: Hunt for Sterile Neutrinos: Decay at Rest Experiments

abstract:
  In the standard model of the elementary particles, the number of neutrino
flavor is three. However, there have been indications of existence of 4th
neutrino, called sterile neutrino, in some neutrino oscillation related
experiments. A number of experiments are planned to test whether such
indications are true or not. Among them, experiments which use neutrinos from
pi+, K+, mu+ decay at rest (DAR) are promising because the energy spectra of
neutrinos are very well known and clean oscillation measurements are possible.
In this proceedings, properties of such DAR neutrinos and LSND, JSNS2, OscSNS
and KPipe experiments are briefly introduced.


title:
Entanglement-assisted codeword stabilized quantum codes with imperfect
  ebits

abstract:
  Quantum error correcting codes (QECCs) in quantum communi- cation systems has
been known to exhibit improved performance with the use of error-free
entanglement bits (ebits). In practical situations, ebits inevitably suffer
from errors, and as a result, the error-correcting capability of the code is
diminished. Prior studies have proposed two different schemes as a solu- tion.
One uses only one QECC to correct errors on the receiver's side (i.e., Bob) and
on the sender's side (i.e., Alice). The other uses different QECCs on each
side. In this paper, we present a method to correct errors on both sides by
using single nonadditive Entanglement-assisted codeword stabilized quantum
error correcting code(EACWS QECC). We use the property that the number of
effective error patterns decreases as much as the number of ebits. This
property results in a greater number of logical codewords using the same number
of physical qubits.


title: Calibration of evolutionary diagnostics in high-mass star formation

abstract:
  The evolutionary classification of massive clumps that are candidate
progenitors of high-mass young stars and clusters relies on a variety of
independent diagnostics based on observables from the near-infrared to the
radio. A promising evolutionary indicator for massive and dense
cluster-progenitor clumps is the L/M ratio between the bolometric luminosity
and the mass of the clumps. With the aim of providing a quantitative
calibration for this indicator we used SEPIA/APEX to obtain CH3C2H(12-11)
observations, that is an excellent thermometer molecule probing densities >
10^5 cm^-3 , toward 51 dense clumps with M>1000 solar masses, and uniformly
spanning -2 < Log(L/M) < 2.3.
  We identify three distinct ranges of L/M that can be associated to three
distinct phases of star formation in massive clumps. For L/M <1 no clump is
detected in CH3C2H , suggesting an inner envelope temperature below 30K. For 1<
L/M < 10 we detect 58% of the clumps, with a temperature between 30 and 35 K
independently from the exact value of L/M; such clumps are building up
luminosity due to the formation of stars, but no star is yet able to
significantly heat the inner clump regions. For L/M> 10 we detect all the
clumps, with a gas temperature rising with Log(L/M), marking the appearance of
a qualitatively different heating source within the clumps; such values are
found towards clumps with UCHII counterparts, suggesting that the quantitative
difference in T - L/M behaviour above L/M >10 is due to the first appearance of
ZAMS stars in the clumps.


title:
Determination of the QCD $\Lambda$-parameter and the accuracy of
  perturbation theory at high energies

abstract:
  We discuss the determination of the strong coupling
$\alpha_\mathrm{\overline{MS}}^{}(m_\mathrm{Z})$ or equivalently the QCD
$\Lambda$-parameter. Its determination requires the use of perturbation theory
in $\alpha_s(\mu)$ in some scheme, $s$, and at some energy scale $\mu$. The
higher the scale $\mu$ the more accurate perturbation theory becomes, owing to
asymptotic freedom. As one step in our computation of the $\Lambda$-parameter
in three-flavor QCD, we perform lattice computations in a scheme which allows
us to non-perturbatively reach very high energies, corresponding to $\alpha_s =
0.1$ and below. We find that (continuum) perturbation theory is very accurate
there, yielding a three percent error in the $\Lambda$-parameter, while data
around $\alpha_s \approx 0.2$ is clearly insufficient to quote such a
precision. It is important to realize that these findings are expected to be
generic, as our scheme has advantageous properties regarding the applicability
of perturbation theory.


title: Dynamic matrix factorization with social influence

abstract:
  Matrix factorization is a key component of collaborative filtering-based
recommendation systems because it allows us to complete sparse user-by-item
ratings matrices under a low-rank assumption that encodes the belief that
similar users give similar ratings and that similar items garner similar
ratings. This paradigm has had immeasurable practical success, but it is not
the complete story for understanding and inferring the preferences of people.
First, peoples' preferences and their observable manifestations as ratings
evolve over time along general patterns of trajectories. Second, an individual
person's preferences evolve over time through influence of their social
connections. In this paper, we develop a unified process model for both types
of dynamics within a state space approach, together with an efficient
optimization scheme for estimation within that model. The model combines
elements from recent developments in dynamic matrix factorization, opinion
dynamics and social learning, and trust-based recommendation. The estimation
builds upon recent advances in numerical nonlinear optimization. Empirical
results on a large-scale data set from the Epinions website demonstrate
consistent reduction in root mean squared error by consideration of the two
types of dynamics.


title: Articulated Hand Pose Estimation Review

abstract:
  With the increase number of companies focusing on commercializing Augmented
Reality (AR), Virtual Reality (VR) and wearable devices, the need for a hand
based input mechanism is becoming essential in order to make the experience
natural, seamless and immersive. Hand pose estimation has progressed
drastically in recent years due to the introduction of commodity depth cameras.
  Hand pose estimation based on vision is still a challenging problem due to
its complexity from self-occlusion (between fingers), close similarity between
fingers, dexterity of the hands, speed of the pose and the high dimension of
the hand kinematic parameters. Articulated hand pose estimation is still an
open problem and under intensive research from both academia and industry.
  The 2 approaches used for hand pose estimation are: discriminative and
generative. Generative approach is a model based that tries to fit a hand model
to the observed data. Discriminative approach is appearance based, usually
implemented with machine learning (ML) and require a large amount of training
data. Recent hand pose estimation uses hybrid approach by combining both
discriminative and generative methods into a single hand pipeline.
  In this paper, we focus on reviewing recent progress of hand pose estimation
from depth sensor. We will survey discriminative methods, generative methods
and hybrid methods. This paper is not a comprehensive review of all hand pose
estimation techniques, it is a subset of some of the recent state-of-the-art
techniques.


title: Interference Management in Massive MIMO HetNets: A Nested Array Approach

abstract:
  The nested array, which is implemented by nonuniform antenna placement, is an
effective approach to achieve O(N^2) degrees of freedom (DoF) with an antenna
array of N antennas. Such DoF refers to the number of directions of incoming
signals that can be resolved. With the increased number of DoF, an important
application of nested array is to nullify the interference signals from
multiple directions. In this paper, we apply nested array in a massive MIMO
heterogeneous network (HetNet) for interference management. With nested array
based interference nulling, each base station (BS) can nullify a certain number
of interference signals. A key design issue is to select the interference
sources to be nullified at each BS. We formulate this problem as an integer
programming problem. The objective is to maximize the sum rate of all users,
subject to BS DoF constraints. We propose an approximation scheme to solve this
problem and derive a performance upper bound. Simulation results show that the
proposed scheme effectively improves the sum rate and achieves a near optimal
performance.


title: Factorization of CP-rank-3 completely positive matrices

abstract:
  A symmetric positive semi-definite matrix A is called completely positive if
there exists a matrix B with nonnegative entries such that A=BB^T. If B is such
a matrix with a minimal number p of columns, then p is called the cp-rank of A.
In this paper we develop a finite and exact algorithm to factorize any matrix A
of cp-rank 3. Failure of this algorithm implies that A does not have cp-rank 3.
Our motivation stems from the question if there exist three nonnegative
polynomials of degree at most four that vanish at the boundary of an interval
and are orthonormal with respect to a certain inner product.


title: On a second numerical index for Banach spaces

abstract:
  We introduce a second numerical index for real Banach spaces with non-trivial
Lie algebra, as the best constant of equivalence between the numerical radius
and the quotient of the operator norm modulo the Lie algebra. We present a
number of examples and results concerning absolute sums, duality, vector-valued
function spaces\ldots which show that, in many cases, the behaviour of this
second numerical index differs from the one of the classical numerical index.
As main results, we prove that Hilbert spaces have second numerical index one
and that they are the only spaces with this property among the class of Banach
spaces with one-unconditional basis and non-trivial Lie algebra. Besides, an
application to the Bishop-Phelps-Bollob\'as property for numerical radius is
given.


title:
Weighted composition operators on spaces of analytic vector-valued
  Lipschitz functions

abstract:
  Let {\phi} be an analytic self-map of D and be an analytic operator-valued
function on D, where D is the unit disk. We provide necessary and sufficient
conditions for the boundedness and compactness of weighted composition
operators W_{\psi,\phi} on Lip_A(D;X;\alpha) and lip_A(D;X;{\alpha}), the
spaces of analytic X-valued Lipschitz functions f, where X is a complex Banach
space and {\alpha} is in (0, 1].


title: Proof of the renormalizability of the gradient flow

abstract:
  We give an alternative perturbative proof of the renormalizability of the
system defined by the gradient flow and the fermion flow in vector-like gauge
theories.


title: Electron spin filter and polarizer in a standing light wave

abstract:
  We demonstrate the theoretical feasibility of spin-dependent diffraction and
spin-polarization of an electron in two counter-propagating, circularly
polarized laser beams. The spin-dynamics appears in a two-photon process of the
Kapitza-Dirac effect in the Bragg regime. We show the spin-dependence of the
diffraction process by comparison of the time-evolution of a spin-up and
spin-down electron in a relativistic quantum simulation. We further discuss the
spin properties of the scattering by studying an analytically approximated
solution of the time-evolution matrix. A classification scheme in terms of
unitary or non-unitary propagation matrices is used for establishing a
generalized and spin-independent description of the spin properties in the
diffraction process.


title:
Spinning boson stars and Kerr black holes with scalar hair: the effect
  of self-interactions

abstract:
  Self-interacting boson stars have been shown to alleviate the astrophysically
low maximal mass of their non-self-interacting counterparts. We report some
physical features of spinning self-interacting boson stars, namely their
compactness, the occurence of ergo-regions and the scalar field profiles, for a
sample of values of the coupling parameter. The results agree with the general
picture that these boson stars are comparatively less compact than the
non-self-interacting ones. We also briefly discuss the effect of scalar
self-interactions on the properties of Kerr black holes with scalar hair.


title:
Synchronization in heterogeneous FitzHugh-Nagumo networks with
  hierarchical architecture

abstract:
  We study synchronization in heterogeneous FitzHugh-Nagumo networks. It is
well known that heterogeneities in the nodes hinder synchronization when
becoming too large. Here, we develop a controller to counteract the impact of
these heterogeneities. We first analyze the stability of the equilibrium point
in a ring network of heterogeneous nodes. We then derive a sufficient condition
for synchronization in the absence of control. Based on these results we derive
the controller providing synchronization for parameter values where
synchronization without control is absent. We demonstrate our results in
networks with different topologies. Particular attention is given to
hierarchical (fractal) topologies, which are relevant for the architecture of
the brain.


title:
Satisfiability-Based Methods for Reactive Synthesis from Safety
  Specifications

abstract:
  Existing approaches to synthesize reactive systems from declarative
specifications mostly rely on Binary Decision Diagrams (BDDs), inheriting their
scalability issues. We present novel algorithms for safety specifications that
use decision procedures for propositional formulas (SAT solvers), Quantified
Boolean Formulas (QBF solvers), or Effectively Propositional Logic (EPR). Our
algorithms are based on query learning, templates, reduction to EPR, QBF
certification, and interpolation. A parallelization combines multiple
algorithms. Our optimizations expand quantifiers and utilize unreachable states
and variable independencies. Our approach outperforms a simple BDD-based tool
and is competitive with a highly optimized one. It won two medals in the
SyntComp competition.


title:
Ward Identity and Homes' Law in a Holographic Superconductor with
  Momentum Relaxation

abstract:
  We study three properties of a holographic superconductor related to
conductivities, where momentum relaxation plays an important role. First, we
find that there are constraints between electric, thermoelectric and thermal
conductivities. The constraints are analytically derived by the Ward identities
regarding diffeomorphism from field theory perspective. We confirm them by
numerically computing all two-point functions from holographic perspective.
Second, we investigate Homes' law and Uemura's law for various high-temperature
and conventional superconductors. They are empirical and (material independent)
universal relations between the superfluid density at zero temperature, the
transition temperature, and the electric DC conductivity right above the
transition temperature. In our model, it turns out that the Homes' law does not
hold but the Uemura's law holds at small momentum relaxation related to
coherent metal regime. Third, we explicitly show that the DC electric
conductivity is finite for a neutral scalar instability while it is infinite
for a complex scalar instability. This shows that the neutral scalar
instability has nothing to do with superconductivity as expected.


title:
Symplectic embeddings of four-dimensional ellipsoids into integral
  polydiscs

abstract:
  In previous work, the second author and M\"uller determined the function
$c(a)$ giving the smallest dilate of the polydisc $P(1,1)$ into which the
ellipsoid $E(1,a)$ symplectically embeds. We determine the function of two
variables $c_b(a)$ giving the smallest dilate of the polydisc $P(1,b)$ into
which the ellipsoid $E(1,a)$ symplectically embeds for all integers $b
\geqslant 2$.
  It is known that for fixed $b$, if $a$ is sufficiently large then all
obstructions to the embedding problem vanish except for the volume obstruction.
We find that there is another kind of change of structure that appears as one
instead increases $b$: the number-theoretic "infinite Pell stairs" from the
$b=1$ case almost completely disappears (only two steps remain), but in an
appropriately rescaled limit, the function $c_b(a)$ converges as $b$ tends to
infinity to a completely regular infinite staircase with steps all of the same
height and width.


title:
Thermodynamics and Phase transition of the Reissner-Nordstr\"om Black
  Hole surrounded by quintessence

abstract:
  We investigate thermodynamics and Phase transition of the
Reissner-Nordstr\"om black hole surrounded by quintessence. Using
thermodynamical laws of black holes, we derive the expressions of some
thermodynamics quantities for the Reissner-Nordstr\"om black hole surrounded by
quintessence. The variations of the temperature and heat capacity with the
entropy were plotted for different values of the state parameter related to the
quintessence, $\omega_{q}$, and the normalization constant related to the
density of quintessence $c$. We show that when varying the entropy of the black
hole a phase transition is observed in the black hole. Moreover, when
increasing the density of quintessence, the transition point is shifted to
lower entropy and the temperature of the black hole decreases.


title:
Nonlinear force dependence on optically bound micro-particle arrays in
  the eva-nescent fields of fundamental and higher order microfibre modes

abstract:
  Particles trapped in the evanescent field of an ultrathin optical fibre
inter-act over very long distances via multiple scattering of the fibre-guided
fields. In ultrathin fibres that support higher order modes, these
interac-tions are stronger and exhibit qualitatively new behaviour due to the
cou-pling of different fibre modes, which have different propagation
wave-vectors, by the particles. Here, we study one dimensional longitudinal
opti-cal binding interactions of chains of 3 {\mu}m polystyrene spheres under
the influence of the evanescent fields of a two-mode microfibre. The
observa-tion of long-range interactions, self-ordering and speed variation of
parti-cle chains reveals strong optical binding effects between the particles
that can be modelled well by a tritter scattering-matrix approach. The optical
forces, optical binding interactions and the velocity of bounded particle
chains are calculated using this method. Results show good agreement with
finite element numerical simulations. Experimental data and theoreti-cal
analysis show that higher order modes in a microfibre offer a promis-ing method
to not only obtain stable, multiple particle trapping or faster particle
propulsion speeds, but that they also allow for better control over each
individual trapped object in particle ensembles near the microfibre surface.


title:
Determining astrophysical three-body radiative capture reaction rates
  from inclusive Coulomb break-up measurements

abstract:
  A relationship between the Coulomb inclusive break-up probability and the
radiative capture reaction rate for weakly-bound three-body systems is
established. This direct link provides a robust procedure to estimate the
reaction rate for nuclei of astrophysical interest by measuring inclusive
break-up processes at different energies and angles. This might be an
advantageous alternative to the determination of reaction rates from the
measurement of $B(E1)$ distributions through exclusive Coulomb break-up
experiments. In addition, it provides a reference to assess the validity of
different theoretical approaches that have been used to calculate reaction
rates. The procedure is applied to $^{11}$Li ($^{9}$Li+n+n) and $^6$He
($^{4}$He+n+n) three-body systems for which some data exist.


title: Double Auctions in Markets for Multiple Kinds of Goods

abstract:
  Motivated by applications such as stock exchanges and spectrum auctions,
there is a growing interest in mechanisms for arranging trade in two-sided
markets. Existing mechanisms are either not truthful, or do not guarantee an
asymptotically-optimal gain-from-trade, or rely on a prior on the traders'
valuations, or operate in limited settings such as a single kind of good. We
extend the random market-halving technique used in earlier works to markets
with multiple kinds of goods, where traders have gross-substitute valuations.
We present MIDA: a Multi Item-kind Double-Auction mechanism. It is prior-free,
truthful, strongly-budget-balanced, and guarantees near-optimal gain from trade
when market sizes of all goods grow to $\infty$ at a similar rate.


title: Understanding the LIGO GW150914 event

abstract:
  We present a simplified method for the extraction of meaningful signals from
Hanford and Livingstone 32 seconds data for the GW150914 event made publicly
available by the LIGO collaboration and demonstrate its ability to reproduce
the LIGO collaboration's own results quantitatively given the assumption that
all narrow peaks in the power spectrum are a consequence of physically
uninteresting signals and can be removed. After the clipping of these peaks and
return to the time domain, the GW150914 event is readily distinguished from
broadband background noise. This simple technique allows us to identify the
GW150914 event without any assumption regarding its physical origin and with
minimal assumptions regarding its shape. We also confirm that the LIGO GW150914
event is uniquely correlated in the Hanford and Livingston detectors for 4096
second data at the level of $6-7\,\sigma$ with a temporal displacement of
$\tau=6.9 \pm 0.4\,$ms. We have also identified a few events that are
morphologically close to GW150914 but less strongly cross correlated with it.


title:
Importance of separated efficiencies between positively and negatively
  charged particles for cumulant calculations

abstract:
  We show the importance of separated efficiency corrections between positively
and negatively charged particles for cumulant calculations by Monte Carlo toy
models and analytical calculations. Our results indicate that S{\sigma} in
published net-proton results from the STAR experiment will be suppressed about
5 to 10% in central collisions, and 10 to 20% in peripheral collisions at the
beam energy of \sqrt s_{NN} = 62.4 and 200 GeV if the separated efficiencies
are used to efficiency correction.


title:
Asymptotical stability of differential equations driven by
  H\"older--continuous paths

abstract:
  In this manuscript, we establish asymptotic local exponential stability of
the trivial solution of differential equations driven by H\"older--continuous
paths with H\"older exponent greater than $1/2$. This applies in particular to
stochastic differential equations driven by fractional Brownian motion with
Hurst parameter greater than $1/2$. We motivate the study of local stability by
giving a particular example of a scalar equation, where global stability of the
trivial solution can be obtained.