title:
The Thirteenth Data Release of the Sloan Digital Sky Survey: First
  Spectroscopic Data from the SDSS-IV Survey MApping Nearby Galaxies at Apache
  Point Observatory

abstract:
  The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began
observations in July 2014. It pursues three core programs: APOGEE-2, MaNGA, and
eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS.
This paper describes the first data release from SDSS-IV, Data Release 13
(DR13), which contains new data, reanalysis of existing data sets and, like all
SDSS data releases, is inclusive of previously released data. DR13 makes
publicly available 1390 spatially resolved integral field unit observations of
nearby galaxies from MaNGA, the first data released from this survey. It
includes new observations from eBOSS, completing SEQUELS. In addition to
targeting galaxies and quasars, SEQUELS also targeted variability-selected
objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new
reductions of the SDSS-III BOSS data, improving the spectrophotometric
calibration and redshift classification. DR13 releases new reductions of the
APOGEE-1 data from SDSS-III, with abundances of elements not previously
included and improved stellar parameters for dwarf stars and cooler stars. For
the SDSS imaging data, DR13 provides new, more robust and precise photometric
calibrations. Several value-added catalogs are being released in tandem with
DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and
an updated red-clump catalog for APOGEE. This paper describes the location and
format of the data now publicly available, as well as providing references to
the important technical papers that describe the targeting, observing, and data
reduction. The SDSS website, http://www.sdss.org, provides links to the data,
tutorials and examples of data access, and extensive documentation of the
reduction and analysis procedures. DR13 is the first of a scheduled set that
will contain new data and analyses from the planned ~6-year operations of
SDSS-IV.


title: Assessing significance in a Markov chain without mixing

abstract:
  We present a new statistical test to detect that a presented state of a
reversible Markov chain was not chosen from a stationary distribution. In
particular, given a value function for the states of the Markov chain, we would
like to demonstrate rigorously that the presented state is an outlier with
respect to the values, by establishing a $p$-value for observations we make
about the state under the null hypothesis that it was chosen uniformly at
random.
  A simple heuristic used in practice is to sample ranks of states from long
random trajectories on the Markov chain, and compare these to the rank of the
presented state; if the presented state is a $0.1\%$-outlier compared to the
sampled ranks (i.e., its rank is in the bottom $0.1\%$ of sampled ranks) then
this should correspond to a $p$-value of $0.001$. This test is not rigorous,
however, without good bounds on the mixing time of the Markov chain, as one
must argue that the observed states on the trajectory approximate the
stationary distribution.
  Our test is the following: given the presented state in the Markov chain,
take a random walk from the presented state for any number of steps. We prove
that observing that the presented state is an $\varepsilon$-outlier on the walk
is significant at $p=\sqrt {2\varepsilon}$, under the null hypothesis that the
state was chosen from a stationary distribution. Our result assumes nothing
about the structure of the Markov chain beyond reversibility, and we construct
examples to show that significance at $p\approx\sqrt \varepsilon$ is
essentially best possible in general. We illustrate the use of our test with a
potential application to the rigorous detection of gerrymandering in
Congressional districtings.


title:
Humans display a reduced set of consistent behavioral phenotypes in
  dyadic games

abstract:
  Socially relevant situations that involve strategic interactions are
widespread among animals and humans alike. To study these situations,
theoretical and experimental works have adopted a game-theoretical perspective,
which has allowed to obtain valuable insights about human behavior. However,
most of the results reported so far have been obtained from a population
perspective and considered one specific conflicting situation at a time. This
makes it difficult to extract conclusions about the consistency of individuals'
behavior when facing different situations, and more importantly, to define a
comprehensive classification of the strategies underlying the observed
behaviors. Here, we present the results of a lab-in-the-field experiment in
which subjects face four different dyadic games, with the aim of establishing
general behavioral rules dictating individuals' actions. By analyzing our data
with an unsupervised clustering algorithm, we find that all the subjects
conform, with a large degree of consistency, to a limited number of behavioral
phenotypes (Envious, Optimist, Pessimist, and Trustful), with only a small
fraction of undefined subjects. We also discuss the possible connections to
existing interpretations based on a priori theoretical approaches. Our findings
provide a relevant contribution to the experimental and theoretical efforts
towards the identification of basic behavioral phenotypes in a wider set of
contexts without aprioristic assumptions regarding the rules or strategies
behind actions. From this perspective, our work contributes to a fact-based
approach to the study of human behavior in strategic situations, that could be
applied to simulating societies, policy-making scenario building and even for a
variety of business applications.


title:
Transporting random measures on the line and embedding excursions into
  Brownian motion

abstract:
  We consider two jointly stationary and ergodic random measures $\xi$ and
$\eta$ on the real line $\mathbb{R}$ with equal intensities. An allocation is
an equivariant random mapping from $\mathbb{R}$ to $\mathbb{R}$. We give
sufficient and partially necessary conditions for the existence of allocations
transporting $\xi$ to $\eta$. An important ingredient of our approach is to
introduce a transport kernel balancing $\xi$ and $\eta$, provided these random
measures are mutually singular. In the second part of the paper, we apply this
result to the path decomposition of a two-sided Brownian motion into three
independent pieces: a time reversed Brownian motion on $(-\infty,0]$, an
excursion distributed according to a conditional It\^o's law and a Brownian
motion starting after this excursion. An analogous result holds for Bismut's
excursion law.


title:
Strong local optimality for a bang-bang-singular extremal: the
  fixed-free case

abstract:
  In this paper we give sufficient conditions for a Pontryagin extremal
trajectory, consisting of two bang arcs followed by a singular one, to be a
strong local minimizer for a Mayer problem. The problem is defined on a
manifold $M$ and the end-points constraints are of fixed-free type. We use a
Hamiltonian approach and its connection with the second order conditions in the
form of an accessory problem on the tangent space to $M$ at the final point of
the trajectory. Two examples are proposed.


title: Interpretation of the cosmic ray positron and antiproton fluxes

abstract:
  The spectral shape of cosmic ray positrons and antiprotons has been
accurately measured in the broad kinetic energy range 1-350 GeV. In the higher
part of this range (E > 30 GeV) the e+ and pbar are both well described by
power laws with spectral indices gamma[e+] = 2.77 +-0.02 and gamma[pbar] = 2.78
+- 0.04 that are approximately equal to each other and to the spectral index of
protons.
  In the same energy range the positron/antiproton flux ratio has the
approximately constant value 2.04+-0.04, that is consistent with being equal to
the ratio e_/pbar calculated for the conventional mechanism of production,
where the antiparticles are created as secondaries in the inelastic
interactions of primary cosmic rays with interstellar gas.
  The positron/antiproton ratio at lower energy is significantly higher
(reaching the approximate value e+/pbar = 100 for E around 1 GeV), but in the
entire energy range 1-350 GeV, the flux ratio is consistent with being equal to
ratio of the production rates in the conventional mechanism, as the production
of low energy antiprotons is kinematically suppressed in collisions with a
target at rest.
  These results strongly suggest that cosmic ray positrons and antiprotons have
a common origin as secondaries in hadronic interactions. This conclusion has
broad implications for the astrophysics of cosmic rays in the Galaxy.


title:
Simultaneous observation of free and defect-bound excitons in CH3NH3PbI3
  using four-wave mixing spectroscopy

abstract:
  Solar cells incorporating organic-inorganic perovskite, which may be
fabricated using low-cost solution-based processing, have witnessed a dramatic
rise in efficiencies yet their fundamental photophysical properties are not
well understood. The exciton binding energy, central to the charge collection
process, has been the subject of considerable controversy due to subtleties in
extracting it from conventional linear spectroscopy techniques due to strong
broadening tied to disorder. Here we report the simultaneous observation of
free and defect-bound excitons in CH3NH3PbI3 films using four-wave mixing (FWM)
spectroscopy. Due to the high sensitivity of FWM to excitons, tied to their
longer coherence decay times than unbound electron-hole pairs, we show that the
exciton resonance energies can be directly observed from the nonlinear optical
spectra. Our results indicate low-temperature binding energies of 13 meV (29
meV) for the free (defect-bound) exciton, with the 16 meV localization energy
for excitons attributed to binding to point defects. Our findings shed light on
the wide range of binding energies (2-55 meV) reported in recent years.


title:
Global well-posedness and scattering for the radial, defocusing, cubic
  wave equation with initial data in a critical Besov space

abstract:
  In this paper we prove that the cubic wave equation is globally well - posed
and scattering for radial initial data lying in $B_{1,1}^{2} \times
B_{1,1}^{1}$. This space of functions is a scale invariant subspace of
$\dot{H}^{1/2} \times \dot{H}^{-1/2}$.


title: An Integrated Recommender Algorithm for Rating Prediction

abstract:
  Recommender system is currently widely used in many e-commerce systems, such
as Amazon, eBay, and so on. It aims to help users to find items which they may
be interested in. In literature, neighborhood-based collaborative filtering and
matrix factorization are two common methods used in recommender systems. In
this paper, we combine these two methods with personalized weights on them.
Rather than using fixed weights for these two methods, we assume each user has
her/his own preference over them. Our results shows that our algorithm
outperforms neighborhood-based collaborative filtering algorithm, matrix
factorization algorithm and their combination with fixed weights.


title: Sums of four polygonal numbers with coefficients

abstract:
  Let $m\ge3$ be an integer. The polygonal numbers of order $m+2$ are given by
$p_{m+2}(n)=m\binom n2+n$ $(n=0,1,2,\ldots)$. A famous claim of Fermat proved
by Cauchy asserts that each nonnegative integer is the sum of $m+2$ polygonal
numbers of order $m+2$. For $(a,b)=(1,1),(2,2),(1,3),(2,4)$, we study whether
any sufficiently large integer can be expressed as $$p_{m+2}(x_1) +
p_{m+2}(x_2) + ap_{m+2}(x_3) + bp_{m+2}(x_4)$$ with $x_1,x_2,x_3,x_4$
nonnegative integers. We show that the answer is positive if
$(a,b)\in\{(1,3),(2,4)\}$, or $(a,b)=(1,1)\ \&\ 4\mid m$, or $(a,b)=(2,2)\ \&\
m\not\equiv 2\pmod 4$. In particular, we confirm a conjecture of Z.-W. Sun
which states that any natural number can be written as $p_6(x_1) + p_6(x_2) +
2p_6(x_3) + 4p_6(x_4)$ with $x_1,x_2,x_3,x_4$ nonnegative integers.


title:
Identifying Designs from Incomplete, Fragmented Cultural Heritage
  Objects by Curve-Pattern Matching

abstract:
  Study of cultural-heritage objects with embellished realistic and abstract
designs made up of connected and intertwined curves crosscuts a number of
related disciplines, including archaeology, art history, and heritage
management. However, many objects, such as pottery sherds found in the
archaeological record, are fragmentary, making the underlying complete designs
unknowable at the scale of the sherd fragment. The challenge to reconstruct and
study complete designs is stymied because 1) most fragmentary cultural-heritage
objects contain only a small portion of the underlying full design, 2) in the
case of a stamping application, the same design may be applied multiple times
with spatial overlap on one object, and 3) curve patterns detected on an object
are usually incomplete and noisy. As a result, classical curve-pattern matching
algorithms, such as Chamfer matching, may perform poorly in identifying the
underlying design. In this paper, we develop a new partial-to-global curve
matching algorithm to address these challenges and better identify the full
design from a fragmented cultural heritage object. Specifically, we develop the
algorithm to identify the designs of the carved wooden paddles of the
Southeastern Woodlands from unearthed pottery sherds. A set of pottery sherds
from the Snow Collection, curated at Georgia Southern University, are used to
test the proposed algorithm, with promising results.


title: Public Opinion Polling with Twitter

abstract:
  Solicited public opinion surveys reach a limited subpopulation of willing
participants and are expensive to conduct, leading to poor time resolution and
a restricted pool of expert-chosen survey topics. In this study, we demonstrate
that unsolicited public opinion polling through sentiment analysis applied to
Twitter correlates well with a range of traditional measures, and has
predictive power for issues of global importance. We also examine Twitter's
potential to canvas topics seldom surveyed, including ideas, personal feelings,
and perceptions of commercial enterprises. Two of our major observations are
that appropriately filtered Twitter sentiment (1) predicts President Obama's
job approval three months in advance, and (2) correlates well with surveyed
consumer sentiment. To make possible a full examination of our work and to
enable others' research, we make public over 10,000 data sets, each a
seven-year series of daily word counts for tweets containing a frequently used
search term.


title: Boundary-based MWE segmentation with text partitioning

abstract:
  This work presents a fine-grained, text-chunking algorithm designed for the
task of multiword expressions (MWEs) segmentation. As a lexical class, MWEs
include a wide variety of idioms, whose automatic identification are a
necessity for the handling of colloquial language. This algorithm's core
novelty is its use of non-word tokens, i.e., boundaries, in a bottom-up
strategy. Leveraging boundaries refines token-level information, forging
high-level performance from relatively basic data. The generality of this
model's feature space allows for its application across languages and domains.
Experiments spanning 19 different languages exhibit a broadly-applicable,
state-of-the-art model. Evaluation against recent shared-task data places text
partitioning as the overall, best performing MWE segmentation algorithm,
covering all MWE classes and multiple English domains (including user-generated
text). This performance, coupled with a non-combinatorial, fast-running design,
produces an ideal combination for implementations at scale, which are
facilitated through the release of open-source software.


title: Photometric Bundle Adjustment for Vision-Based SLAM

abstract:
  We propose a novel algorithm for the joint refinement of structure and motion
parameters from image data directly without relying on fixed and known
correspondences. In contrast to traditional bundle adjustment (BA) where the
optimal parameters are determined by minimizing the reprojection error using
tracked features, the proposed algorithm relies on maximizing the photometric
consistency and estimates the correspondences implicitly. Since the proposed
algorithm does not require correspondences, its application is not limited to
corner-like structure; any pixel with nonvanishing gradient could be used in
the estimation process. Furthermore, we demonstrate the feasibility of refining
the motion and structure parameters simultaneously using the photometric in
unconstrained scenes and without requiring restrictive assumptions such as
planarity. The proposed algorithm is evaluated on range of challenging outdoor
datasets, and it is shown to improve upon the accuracy of the state-of-the-art
VSLAM methods obtained using the minimization of the reprojection error using
traditional BA as well as loop closure.


title:
Inferring brain-computational mechanisms with models of activity
  measurements

abstract:
  High-resolution functional imaging is providing increasingly rich
measurements of brain activity in animals and humans. A major challenge is to
leverage such data to gain insight into the brain's computational mechanisms.
The first step is to define candidate brain-computational models (BCMs) that
can perform the behavioural task in question. We would then like to infer,
which of the candidate BCMs best accounts for measured brain-activity data.
Here we describe a method that complements each BCM by a measurement model
(MM), which simulates the way the brain-activity measurements reflect neuronal
activity (e.g. local averaging in fMRI voxels or sparse sampling in array
recordings). The resulting generative model (BCM-MM) produces simulated
measurements. In order to avoid having to fit the MM to predict each individual
measurement channel of the brain-activity data, we compare the measured and
predicted data at the level of summary statistics. We describe a novel
particular implementation of this approach, called probabilistic RSA (pRSA)
with measurement models, which uses representational dissimilarity matrices
(RDMs) as the summary statistics. We validate this method by simulations of
fMRI measurements (locally averaging voxels) based on a deep convolutional
neural network for visual object recognition. Results indicate that the way the
measurements sample the activity patterns strongly affects the apparent
representational dissimilarities. However, modelling of the measurement process
can account for these effects and different BCMs remain distinguishable even
under substantial noise. The pRSA method enables us to perform Bayesian
inference on the set of BCMs and to recognise the data-generating model in each
case.


title:
Explicit Heston Solutions and Stochastic Approximation for
  Path-dependent Option Pricing

abstract:
  New simulation approaches to evaluating path-dependent options without matrix
inversion issues nor Euler bias are evaluated. They employ three main
contributions: Stochastic approximation replaces regression in the LSM
algorithm; Explicit weak solutions to stochastic differential equations are
developed and applied to Heston model simulation; and Importance sampling
expands these explicit solutions. The approach complements Heston (1993) and
Broadie and Kaya (2006) by handling the case of path-dependence in the option's
execution strategy. Numeric comparison against standard Monte Carlo methods
demonstrate up to two orders of magnitude speed improvement. The general ideas
will extend beyond the important Heston setting.


title: Formalization of the prime number theorem and Dirichlet's theorem

abstract:
  We present the formalization of Dirichlet's theorem on the infinitude of
primes in arithmetic progressions, and Selberg's elementary proof of the prime
number theorem, which asserts that the number $\pi(x)$ of primes less than $x$
is asymptotic to $x/\log x$, within the proof system Metamath.


title: Partition Identities and Quiver Representations

abstract:
  We present a particular connection between classical partition combinatorics
and the theory of quiver representations. Specifically, we give a bijective
proof of an analogue of A. L. Cauchy's Durfee square identity to
multipartitions. We then use this result to give a new proof of M. Reineke's
identity in the case of quivers $Q$ of Dynkin type $A$ of arbitrary
orientation. Our identity is stated in terms of the lacing diagrams of S.
Abeasis - A. Del Fra, which parameterize orbits of the representation space of
$Q$ for a fixed dimension vector.


title:
Global existence and asymptotic behavior of classical solutions to a
  parabolic-elliptic chemotaxis system with logistic source on $\mathbb{R}^{N}$

abstract:
  In the current paper, we consider the following parabolic-elliptic semilinear
Keller-Segel model on $\mathbb{R}^{N}$, \begin{equation*} \begin{cases}
u_{t}=\nabla\cdot (\nabla u-\chi u\nabla v)+a u -b u^2, \quad
x\in\mathbb{R}^N,\,\, t>0\cr 0=(\Delta- I)v+ u, \quad x\in\mathbb{R}^N,\,\,
t>0, \end{cases} \end{equation*} where $ \chi >0, \ a\ge 0,\ b> 0$ are constant
real numbers and $N$ is a positive integer. We first prove the local existence
and uniqueness of classical solutions $(u(x,t;u_0),v(x,t;u_0))$ with
$u(x,0;u_0)=u_0(x)$ for various initial functions $u_0(x)$. Next, under some
conditions on the constants $a, b, \chi$ and the dimension $N$, we prove the
global existence and boundedness of classical solution
$(u(x,t;u_0),v(x,t;u_0))$ for given initial functions $u_0(x)$. Finally, we
investigate the asymptotic behavior of the global solutions with strictly
positive initial functions or nonnegative compactly supported initial
functions. Under some conditions on the constants $a, b, \chi$ and the
dimension $N$, we show that for every strictly positive initial function
$u_0(\cdot)$, $$\lim_{t\to\infty} \sup_{x\in\mathbb{R}^N}
\big[|u(x,t;u_0)-\frac{a}{b}|+|v(x,t;u_0)-\frac{a}{b}|\big]=0,$$ and that for
every nonnegative initial function $u_0(\cdot)$ with non-empty and compact
support ${\rm supp}(u_0)$, there are $0<c_{\rm low}^*(u_0)\leq c_{\rm
up}^*(u_0)<\infty$ such that $$\lim_{t\to\infty} \sup_{|x|\leq ct}
\big[|u(x,t;u_0)-\frac{a}{b}|+|v(x,t;u_0)-\frac{a}{b}|\big]=0\quad \forall\,\,
0<c<c_{\rm low}^*(u_0)$$ and $$\lim_{t\to\infty}\sup_{|x|\geq ct}
\big[u(x,t;u_0)+v(x,t;u_0)\big]=0\quad \forall\,\, c>c_{\rm up}^*(u_0).$$


title: Unique coverage in Boolean models

abstract:
  Consider a wireless cellular network consisting of small, densely scattered
base stations. A user $u$ is {\em uniquely covered} by a base station $b$ if
$u$ is the only user within distance $r$ of $b$. This makes it possible to
assign the user $u$ to the base station $b$ without interference from any other
user $u'$. We investigate the maximum possible proportion of users who are
uniquely covered. We solve this problem completely in one dimension and provide
bounds, approximations and simulation results for the two-dimensional case.


title:
The Circum-Galactic Medium of MASsive Spirals I: Overview and a Case
  Study of NGC 5908

abstract:
  The Circum-Galactic Medium of MASsive Spirals (CGM-MASS) is a project
studying the overall content, physical and chemical properties, and spatial
distributions of the multi-phase circum-galactic medium (CGM) around a small
sample of the most massive isolated spiral galaxies in the local Universe. We
introduce the sample and present a detailed case study of the XMM-Newton
observation of the hot gas halo of NGC5908. After data calibration, point
source removal, and background analysis, we find that the diffuse soft X-ray
emission of NGC5908 is significantly more extended than the stellar light in
the vertical direction. The 0.5-1.25keV radial intensity profile tracing hot
gas emission can be detected above the background out to about $2^\prime$, or
$30\rm~kpc$ from the nucleus. The unresolved soft X-ray emission can be
characterized with a $\beta$-model with a slope of $\beta\approx0.68$. The
unresolved 0.5-2keV luminosity within $1^\prime$ is
$6.8\times10^{39}\rm~ergs~s^{-1}$, but young stellar sources may contribute
significantly to it. Assuming a metallicity of 0.2solar, an upper limit
(without subtracting the very uncertain young stellar contribution) to the mass
of hot gas within this radius is $2.3\times10^9\rm~M_\odot$. The cooling radius
is $r_{\rm cool}\approx25\rm~kpc$ or $\approx0.06r_{\rm 200}$, within which the
hot gas could cool radiatively in less than 10Gyr, and the cooling of hot gas
could significantly contribute in replenishing the gas consumed in star
formation. The hot gas accounts for $\approx1.9\%$ of the baryon detected
within the cooling radius. By comparing NGC5908 to other galaxies, we find that
its X-ray luminosity per stellar mass is consistent with lower-mass
non-starburst field spiral galaxies. However, a large scatter in hot gas soft
X-ray emissivity is indicated for spiral galaxies with
$M_*\gtrsim2\times10^{11}\rm~M_\odot$.


title: Modelling the effect of acoustic waves on nucleation

abstract:
  A phase transformation in a metastable phase can be affected when it is
subjected to a high intensity ultrasound wave. In this study we determined the
effect of oscillation in pressure and temperature on a phase transformation
using the Gibbs droplet model in a generic format. The developed model is valid
for both equilibrium and non-equilibrium clusters formed through a stationary
or non-stationary process. We validated the underlying model by comparing the
predicted kinetics of water droplet formation from the gas phase against
experimental data in the absence of ultrasound. Our results demonstrated better
agreement with experimental data in comparison with classical nucleation
theory. Then, we determined the thermodynamics and kinetics of nucleation and
the early stage of growth of clusters in an isothermal sonocrystallisation
process. This new contribution shows that the effect of pressure on the
kinetics of nucleation is cluster size-dependent in contrast to classical
nucleation theory.


title: A proof of Friedman's ergosphere instability for scalar waves

abstract:
  Let $(\mathcal{M}^{3+1},g)$ be a real analytic, stationary and asymptotically
flat spacetime with a non-empty ergoregion $\mathscr{E}$ and no future event
horizon $\mathcal{H}^{+}$. On such spacetimes, Friedman provided a heuristic
argument that the energy of certain solutions $\phi$ of $\square_{g}\phi=0$
grows to $+\infty$ as time increases. In this paper, we provide a rigorous
proof of Friedman's instability. Our setting is, in fact, more general. We
consider smooth spacetimes $(\mathcal{M}^{d+1},g)$, for any $d\ge2$, not
necessarily globally real analytic. We impose only a unique continuation
condition for the wave equation across the boundary $\partial\mathscr{E}$ of
$\mathscr{E}$ on a small neighborhood of a point $p\in\partial\mathscr{E}$.
This condition always holds if $(\mathcal{M},g)$ is analytic in that
neighborhood of $p$, but it can also be inferred in the case when
$(\mathcal{M},g)$ possesses a second Killing field $\Phi$ such that the span of
$\Phi$ and the stationary Killing field $T$ is timelike on
$\partial\mathscr{E}$. We also allow the spacetimes $(\mathcal{M},g)$ under
consideration to possess a (possibly empty) future event horizon
$\mathcal{H}^{+}$, such that, however,
$\mathcal{H}^{+}\cap\mathscr{E}=\emptyset$ (excluding, thus, the Kerr exterior
family). As an application of our theorem, we infer an instability result for
the acoustical wave equation on the hydrodynamic vortex, a phenomenon first
investigated numerically by Oliveira, Cardoso and Crispino. Furthermore, as a
side benefit of our proof, we provide a derivation, based entirely on the
vector field method, of a Carleman-type estimate on the exterior of the
ergoregion for a general class of stationary and asymptotically flat
spacetimes.


title: Pre-potential in the $AdS_{5}\,\times\,S^{5}$ Type IIB superspace

abstract:
  We found the pre-potential in the superspace with $AdS_{5}\,\times\,S^{5}$
background. The pre-potential appears as part of the vielbeins, without
derivatives. The space-cone gauge destroys the bulk Lorentz covariance, but
still preserves boundary Lorentz covariance (projective superspace)
$SO\,(\,3,\,1\,)\,\otimes\,SO\,(\,4\,)$, i.e. symmetries of boundary CFT are
manifest.


title: Concordance invariance of Levine-Tristram signatures of links

abstract:
  We determine for which complex numbers on the unit circle the Levine-Tristram
signature and the nullity give rise to link concordance invariants.


title:
Responding to an enquiry concerning the geographic population structure
  (GPS) approach and the origin of Ashkenazic Jews - a reply to Flegontov et al

abstract:
  Recently, we investigated the geographical origins of Ashkenazic Jews (AJs)
and their native language Yiddish by applying a biogeographical tool, the
Geographic Population Structure (GPS), to a cohort of 367 exclusively
Yiddish-speaking and multilingual AJs genotyped on the Genochip microarray. GPS
localized most AJs along major ancient trade routes in northeastern Turkey
adjacent to primeval villages with names that may be derived from the word
"Ashkenaz." These findings were compatible with the hypothesis of an
Irano-Turko-Slavic origin for AJs and a Slavic origin for Yiddish and at odds
with the Rhineland hypothesis advocating a German origin of both. Our approach
has been recently adopted by Flegontov et al. (2016a) to trace the origin of
the Siberian Ket people and their language. Recently, Flegontov et al. (2016b)
have raised several questions concerning the accuracy of the Genochip
microarray and GPS, specifically in relation to AJs and Yiddish. Although many
of these issues have been addressed in our previous papers, we take this
opportunity to clarify the principles of the GPS approach, review the recent
biogeographical and ancient DNA findings regarding AJs, and comment on the
origin of Yiddish.


title: Left-ordered inp-minimal groups

abstract:
  We prove that any left-ordered inp-minimal group is abelian, and we provide
an example of a non-abelian left-ordered group of dp-rank 2.


title: A Toy Model of Entwinement

abstract:
  Entwinement is the entanglement entropy of a subset of gauge-variant degrees
of freedom in a certain twisted state of an orbifold CFT, defined by embedding
the state in a larger Hilbert space with some gauge constraints removed. We
propose an intrinsically gauge-invariant, algebraic definition of entwinement.
Our main piece of evidence is a computation showing that, in a spin system that
resembles the orbifold CFT, the analog of entwinement is the entanglement
entropy of a gauge-invariant subalgebra, which we identify. We review why
entwinement is relevant for the conjecture that entanglement builds spacetime.


title:
Superradiant instabilities for short-range non-negative potentials on
  Kerr spacetimes and applications

abstract:
  The wave equation $\square_{g_{M,a}}\psi=0$ on subextremal Kerr spacetimes
$(\mathcal{M}_{M,a},g_{M,a})$, $0<|a|<M$, does not admit real mode solutions,
as was established by Shlapentokh-Rothman. In this paper, we show that the
absence of real modes does not persist under the addition of an arbitrary
short-range non-negative potential $V$ to the wave equation or under changes of
the metric $g_{M,a}$ in the far away region of $\mathcal{M}_{M,a}$ (retaining
the causality of $T$ there).
  In particular, we first establish, for any $0<|a|<M$, the existence of real
mode solutions $\psi$ to equation $\square_{g_{M,a}}\psi-V\psi=0$, for a
suitably chosen time-independent real potential $V$ with compact support in
space, satisfying $V\ge0$. Exponentially growing modes are also obtained after
perturbing the potential $V$. Then, as an application of the above result, we
construct a family of spacetimes $(\mathcal{M}_{M,a},g_{M,a}^{(def)})$ which
are compact in space perturbations of $(\mathcal{M}_{M,a},g_{M,a})$, have the
same symmetries as $(\mathcal{M}_{M,a},g_{M,a})$ and moreover admit real and
exponentially growing modes. These spacetimes contain stably trapped null
geodesics, but we also construct a more complicated family of spacetimes with
normally hyperbolic trapped set, admitting real and exponentially growing
modes, at the expense of having conic asymptotics.
  The above results are in contrast with the case of stationary asymptotically
flat (or conic) spacetimes $(\mathcal{M},g)$ with a globally timelike Killing
field $T$, where real modes for equation $\square_{g}\psi-V\psi=0$ are always
absent, giving a useful zero-frequency continuity criterion for showing
stability for a smooth family of equations $\square_{g}\psi-V_{\lambda}\psi=0$,
with $\lambda\in[0,1]$ and $V_{0}=0$. We show explicitly that this criterion
fails on Kerr spacetime.


title:
Reduced models and design principles for half-harmonic generation in
  synchronously-pumped optical parametric oscillators

abstract:
  We develop reduced models that describe half-harmonic generation in a
synchronously-pumped optical parametric oscillator above threshold, where
nonlinearity, dispersion, and group-velocity mismatch are all relevant. These
models are based on (1) an eigenmode expansion for low pump powers, (2) a
simulton-like sech-pulse ansatz for intermediate powers, and (3) dispersionless
box-shaped pulses for high powers. Analytic formulas for pulse compression,
degenerate vs. nondegenerate operation, and stability are derived and compared
to numerical and experimental results.


title:
Defects as a factor limiting carrier mobility in WSe2: a spectroscopic
  investigation

abstract:
  The electrical performance of two dimensional transitional metal
dichalcogenides (TMDs) is strongly influenced by the amount of structural
defects inside. In this work, we provide an optical spectroscopic
characterization approach to correlate the amount of structural defects and the
electrical performance of WSe2 devices. Low temperature photoluminescence (PL)
spectra of electron beam lithography (EBL) processed WSe2 presents a clear
defect-induced PL emission due to excitons bound to defects, which would
strongly degrade the electrical performance. By adopting an e-beam-free
transfer-electrode technique, we are able to prepare backgated WSe2 device with
limited amount of defects. A maximum hole-mobility of about 200 cm2/Vs was
achieved due to reduced scattering sources, which is the highest reported value
among its type. This work would not only provide a versatile and nondestructive
method to monitor the defects in TMDs, but also a new route to approach the
room temperature phonon-limited mobility in high performance TMDs devices.


title:
Boundary estimates for a degenerate parabolic equation with partial
  Dirichlet boundary conditions

abstract:
  We study the boundary regularity properties and derive a priori pointwise
supremum estimates of weak solutions and their derivatives in terms of suitable
weighted $L^2$-norms for a class of degenerate parabolic equations that satisfy
homogeneous Dirichlet boundary conditions on certain portions of the boundary.
Such equations arise in population genetics in the study of models for the
evolution of gene frequencies. Among the applications of our results is the
description of the structure of the transition probabilities and of the hitting
distributions of the underlying gene frequencies process, which correspond to
the fundamental solution and the caloric measure of the parabolic equation,
respectively.


title: Spectrum estimation of density operators with alkaline-earth atoms

abstract:
  We show that Ramsey spectroscopy of fermionic alkaline-earth atoms in a
square-well trap provides an efficient and accurate estimate for the
eigenspectrum of a density matrix whose $n$ copies are stored in the nuclear
spins of $n$ such atoms. This spectrum estimation is enabled by the high
symmetry of the interaction Hamiltonian, dictated, in turn, by the decoupling
of the nuclear spin from the electrons and by the shape of the square-well
trap. Practical performance of this procedure and its potential applications to
quantum computing, quantum simulation, and time-keeping with alkaline-earth
atoms are discussed.


title:
Thermoelectric transport through Majorana bound states and violation of
  Wiedemann-Franz law

abstract:
  We study features of the thermoelectric transport through a Kitaev chain
hosting Majorana bound states (MBS) at its ends. We describe the behavior of
the Seebeck coefficient and the ZT figure of merit for two different
configurations between MBS and normal current leads. We find an important
violation of the Wiedemann-Franz law in one of these geometries, leading to
sizeable values of the thermoelectric efficiency over a narrow window in
chemical potential away from neutrality. These findings could lead to
interesting thermoelectric-based MBSs detection devices, via measurements of
the Seebeck coefficient and figure of merit.


title: Infinitesimal generators of invertible evolution families

abstract:
  A logarithm representation of operators is introduced as well as a concept of
pre-infinitesimal generator. Generators of invertible evolution families are
represented by the logarithm representation, and a set of operators represented
by the logarithm is shown to be associated with analytic semigroups.
Consequently generally-unbounded infinitesimal generators of invertible
evolution families are characterized by a convergent power series
representation.


title:
Global well-posedness for the 3D incompressible inhomogeneous
  Navier-Stokes equations and MHD equations

abstract:
  The present paper is dedicated to the global well-posedness for the 3D
inhomogeneous incompressible Navier-Stokes equations, in critical Besov spaces
without smallness assumption on the variation of the density. We aim at
extending the work by Abidi, Gui and Zhang (Arch. Ration. Mech. Anal. 204
(1):189--230, 2012, and J. Math. Pures Appl. 100 (1):166--203, 2013) to a more
lower regularity index about the initial velocity. The key to that improvement
is a new a priori estimate for an elliptic equation with nonconstant
coefficients in Besov spaces which have the same degree as $L^2$ in
$\mathbb{R}^3$. Finally, we also generalize our well-posedness result to the
inhomogeneous incompressible MHD equations.


title: Weighted complete intersection del Pezzo surfaces

abstract:
  We classify codimension 2 well-formed and quasi-smooth weighted complete
intersection del Pezzo surfaces.


title:
SHOCKFIND - An algorithm to identify magnetohydrodynamic shock waves in
  turbulent clouds

abstract:
  The formation of stars occurs in the dense molecular cloud phase of the
interstellar medium. Observations and numerical simulations of molecular clouds
have shown that supersonic magnetised turbulence plays a key role for the
formation of stars. Simulations have also shown that a large fraction of the
turbulent energy dissipates in shock waves. The three families of MHD shocks
--- fast, intermediate and slow --- distinctly compress and heat up the
molecular gas, and so provide an important probe of the physical conditions
within a turbulent cloud. Here we introduce the publicly available algorithm,
SHOCKFIND, to extract and characterise the mixture of shock families in MHD
turbulence. The algorithm is applied to a 3-dimensional simulation of a
magnetised turbulent molecular cloud, and we find that both fast and slow MHD
shocks are present in the simulation. We give the first prediction of the
mixture of turbulence-driven MHD shock families in this molecular cloud, and
present their distinct distributions of sonic and Alfvenic Mach numbers. Using
subgrid one-dimensional models of MHD shocks we estimate that ~0.03 % of the
volume of a typical molecular cloud in the Milky Way will be shock heated above
50 K, at any time during the lifetime of the cloud. We discuss the impact of
this shock heating on the dynamical evolution of molecular clouds.


title: Compressive Change Retrieval for Moving Object Detection

abstract:
  Change detection, or anomaly detection, from street-view images acquired by
an autonomous robot at multiple different times, is a major problem in robotic
mapping and autonomous driving. Formulation as an image comparison task, which
operates on a given pair of query and reference images is common to many
existing approaches to this problem. Unfortunately, providing relevant
reference images is not straightforward. In this paper, we propose a novel
formulation for change detection, termed compressive change retrieval, which
can operate on a query image and similar reference images retrieved from the
web. Compared to previous formulations, there are two sources of difficulty.
First, the retrieved reference images may frequently contain non-relevant
reference images, because even state-of-the-art place-recognition techniques
suffer from retrieval noise. Second, image comparison needs to be conducted in
a compressed domain to minimize the storage cost of large collections of
street-view images. To address the above issues, we also present a practical
change detection algorithm that uses compressed bag-of-words (BoW) image
representation as a scalable solution. The results of experiments conducted on
a practical change detection task, "moving object detection (MOD)," using the
publicly available Malaga dataset validate the effectiveness of the proposed
approach.


title:
Multi-Model Hypothesize-and-Verify Approach for Incremental Loop Closure
  Verification

abstract:
  Loop closure detection, which is the task of identifying locations revisited
by a robot in a sequence of odometry and perceptual observations, is typically
formulated as a visual place recognition (VPR) task. However, even
state-of-the-art VPR techniques generate a considerable number of false
positives as a result of confusing visual features and perceptual aliasing. In
this paper, we propose a robust incremental framework for loop closure
detection, termed incremental loop closure verification. Our approach
reformulates the problem of loop closure detection as an instance of a
multi-model hypothesize-and-verify framework, in which multiple loop closure
hypotheses are generated and verified in terms of the consistency between loop
closure hypotheses and VPR constraints at multiple viewpoints along the robot's
trajectory. Furthermore, we consider the general incremental setting of loop
closure detection, in which the system must update both the set of VPR
constraints and that of loop closure hypotheses when new constraints or
hypotheses arrive during robot navigation. Experimental results using a stereo
SLAM system and DCNN features and visual odometry validate effectiveness of the
proposed approach.


title: Modeling Growth Curve of Fractal Dimension of Urban Form of Beijing

abstract:
  The growth curves of fractal dimension of urban form take on squashing effect
and can be described by sigmoid functions. The fractal dimension growth of
urban form in western countries can be modeled by Boltzmann's equation and
logistic function. However, these models cannot be well applied to the fractal
dimension growth curve of Beijing city, the national capital of China. In this
paper, the experimental method is employed to find parametric models for the
growth curves of fractal dimension of Chinese urban form. By statistical
analysis, numerical analysis, and comparative analysis, we find that the
quadratic Boltzmann equation and quadratic logistic function can be used to
characterize how the fractal dimension of the urban land-use pattern of Beijing
increases in the course of time. The models are also suitable for many cities
in the north of China. In order to convert the empirical models into
theoretical models, we attempt to construct a model of spatial replacement
dynamics of urban evolution, from which the logistic model of urban fractal
dimension growth can be derived. The models can be utilized to predict the rate
and upper limitation of Chinese urban growth. In particular, the models can be
employed to reveal the similarities and differences between the fractal growth
of Chinese cities and that of the cities in western countries.


title:
Equivalent Relation between Normalized Spatial Entropy and Fractal
  Dimension

abstract:
  Fractal dimension is defined on the base of entropy, including macro state
entropy and information entropy. The generalized correlation dimension of
multifractals is based on Renyi entropy. However, the mathematical transform
from entropy to fractal dimension is not yet clear in both theory and practice.
This paper is devoted to revealing the new equivalence relation between spatial
entropy and fractal dimension using functional box-counting method. Based on
varied regular fractals, the numerical relationship between spatial entropy and
fractal dimension is examined. The results show that the ratio of actual
entropy (Mq) to the maximum entropy (Mmax) equals the ratio of actual dimension
(Dq) to the maximum dimension (Dmax). The spatial entropy and fractal dimension
of complex spatial systems can be converted into one another by means of
functional box-counting method. The theoretical inference is verified by
observational data of urban form. A conclusion is that normalized spatial
entropy is equal to normalized fractal dimension. Fractal dimensions proved to
be the characteristic values of entropies. In empirical studies, if the linear
size of spatial measurement is small enough, a normalized entropy value is
infinitely approximate to the corresponding normalized fractal dimension value.
Based on the theoretical result, new spatial measurements of urban space
filling can be defined, and multifractal parameters can be generalized to
describe both simple systems and complex systems.


title: The generalized 3-(edge) connectivity of total graphs

abstract:
  The generalized $k$-connectivity $\kappa_k(G)$ of a graph $G$, introduced by
Hager in 1985, is a natural generalization of the concept of connectivity
$\kappa(G)$, which is just for $k=2$. Total graph is generalized line graph and
a large graph which obtained by incidence relation between vertices and edges
of original graph. T. Hamada and T. Nonaka et al., in \cite{Hamada} determined
the connectivity of the total graph $T(G)$ for a graph $G$. In this paper we
determine the generalized $k$-(edge)-connectivity of total graph $T(G)$ for
$k=3$.


title:
Simplifying the one loop five graviton amplitude in type IIB string
  theory

abstract:
  We consider the D^8 R^5 and D^{10} R^5 terms in the low momentum expansion of
the five graviton amplitude in type IIB string theory at one loop. They involve
integrals of various modular graph functions over the fundamental domain of
SL(2,Z). Unlike the graphs which arise in the four graviton amplitude or at
lower orders in the momentum expansion of the five graviton amplitude where the
links are given by scalar Green functions, there are several graphs for the D^8
R^5 and D^{10} R^5 terms where two of the links are each given by a derivative
of the Green function. Starting with appropriate auxiliary diagrams, we show
that these graphs can be expressed in terms of those which do not involve any
derivatives. This results in considerable simplification of the amplitude.


title:
Slipping Magnetic Reconnection of Flux Rope Structures as a Precursor to
  an Eruptive X-class Solar Flare

abstract:
  We present the quasi-periodic slipping motion of flux rope structures prior
to the onset of an eruptive X-class flare on 2015 March 11, obtained by the
\emph{Interface Region Imaging Spectrograph} (\emph{IRIS}) and the \emph{Solar
Dynamics Observatory} (\emph{SDO}). The slipping motion occurred at the north
part of the flux rope and seemed to successively peel off the flux rope. The
speed of the slippage was 30$-$40 km s$^{-1}$, with an average period of
130$\pm$30 s. The Si {\sc iv} 1402.77 {\AA} line showed a redshift of 10$-$30
km s$^{-1}$ and a line width of 50$-$120 km s$^{-1}$ at the west legs of
slipping structures, indicative of reconnection downflow. The slipping motion
lasted about 40 min and the flux rope started to rise up slowly at the late
stage of the slippage. Then an X2.1 flare was initiated and the flux rope was
impulsively accelerated. One of the flare ribbons swept across a
negative-polarity sunspot and the penumbral segments of the sunspot decayed
rapidly after the flare. We studied the magnetic topology at the flaring region
and the results showed the existence of a twisted flux rope, together with
quasi-separatrix layers (QSLs) structures binding the flux rope. Our
observations imply that quasi-periodic slipping magnetic reconnection occurs
along the flux-rope-related QSLs in the preflare stage, which drives the later
eruption of the flux rope and the associated flare.


title:
Non-singular field-only surface integral equations for electromagnetic
  scattering

abstract:
  A boundary integral formulation of electromagnetics that involves only the
components of $\boldsymbol{E}$ and $\boldsymbol{H}$ is derived without the use
of surface currents that appear in the classical PMCHWT formulation. The
kernels of the boundary integral equations for $\boldsymbol{E}$ and
$\boldsymbol{H}$ are non-singular so that all field quantities at the surface
can be determined to high precision and also geometries with closely spaced
surfaces present no numerical difficulties. Quadratic elements can readily be
used to represent the surfaces so that the surface integrals can be calculated
to higher numerical precision than using planar elements for the same numbers
of degrees of freedom.


title: Signs in time: Encoding human motion as a temporal image

abstract:
  The goal of this work is to recognise and localise short temporal signals in
image time series, where strong supervision is not available for training.
  To this end we propose an image encoding that concisely represents human
motion in a video sequence in a form that is suitable for learning with a
ConvNet. The encoding reduces the pose information from an image to a single
column, dramatically diminishing the input requirements for the network, but
retaining the essential information for recognition.
  The encoding is applied to the task of recognizing and localizing signed
gestures in British Sign Language (BSL) videos. We demonstrate that using the
proposed encoding, signs as short as 10 frames duration can be learnt from
clips lasting hundreds of frames using only weak (clip level) supervision and
with considerable label noise.


title:
Weighted diffusion LMP algorithm for distributed estimation in
  non-uniform noise conditions

abstract:
  This letter presents an improved version of diffusion least mean ppower (LMP)
algorithm for distributed estimation. Instead of sum of mean square errors, a
weighted sum of mean square error is defined as the cost function for global
and local cost functions of a network of sensors. The weight coefficients are
updated by a simple steepest-descent recursion to minimize the error signal of
the global and local adaptive algorithm. Simulation results show the advantages
of the proposed weighted diffusion LMP over the diffusion LMP algorithm
specially in the non-uniform noise conditions in a sensor network.


title: Exclusions on $Z'$ mass and its non-universal couplings in LFV decays

abstract:
  This letter presents a phenomenological analysis for the lepton ($l_i^{}$)
decaying into $ l_j^{} l_k^{} \bar{l}_k^{}, l_j^{} \pi^+ \pi^-$ considering
family non-universal couplings as source of the lepton flavor-violating (LFV)
currents and a new neutral gauge boson ($Z'$) as mediator in the
flavor-changing. The most viable $g_{V}^{f_if_J}$ and $g_{A}^{f_if_j}$
couplings are reported as long as derive new bounds for the $M_{Z'}^{}$ by
using current results from LHC and a phenomenological analysis.


title: The primordial helium abundance and the number of neutrino families

abstract:
  Based on observations of HII regions and the new computations of the
recombination coefficients of the He I lines by Porter et al. (2013) we obtain
a primordial helium abundance by mass of $Y_P = 0.2446\pm0.0029$. We consider
thirteen sources of error for the $Y_P$ determination, some of them are mainly
due to systematic effects, while the rest are mainly due to statistical
effects. We compare our results with other determinations of $Y_P$ present in
the literature. Combining our $Y_P$ value with computations of primordial
nucleosynthesis we find a number of neutrino species $N_{eff} = 2.90\pm0.22$,
and a neutron mean life $\tau_{\nu} = 872\pm14(s)$.


title: A short proof of telescopic Tate vanishing

abstract:
  We give a short proof of a theorem of Kuhn that Tate constructions for finite
group actions vanish in telescopically localized stable homotopy theory. In
particular, we observe that Kuhn's theorem is equivalent to the statement that
the transfer $BC_{p+} \to S^0$ admits a section after telescopic localization,
which in turn follows from the Kahn-Priddy theorem.


title: Frustrated S=1/2 Two-Leg Ladder with Different Leg Interactions

abstract:
  We explore the ground-state phase diagram of the $S\!=\!1/2$ two-leg ladder
with different isotropic leg interactions and uniform anisotropic rung ones,
which is described by the Hamiltonian ${\cal H}=J_{{\rm l},a}
\sum\nolimits_{j=1}^{L}{\vec S}_{j,a}\cdot {\vec S}_{j+1,a}+J_{{\rm l},b}
\sum\nolimits_{j=1}^{L} {\vec S}_{j,b}\cdot {\vec S}_{j+1,b}+J_{\rm r}
\sum\nolimits_{j=1}^{L} \bigl\{S_{j,a}^x S_{j,b}^x + S_{j,a}^y S_{j,b}^y +
\Delta S_{j,a}^z S_{j,b}^z \bigr\}$. This system has a frustration when
$J_{{\rm l},a} J_{{\rm l},b}\!<\!0$ irrespective of the sign of $J_{\rm r}$.
The phase diagrams on the $\Delta$ ($0\!\leq\!\Delta\!<\!1$) versus $J_{{\rm
l},b}$ plane in the cases of {$J_{{\rm l},a}\!=\!-0.2$ and $J_{{\rm
l},a}\!=\!0.2$ with $J_{{\rm r}}\!=\!-1$ are determined numerically. We employ
the physical consideration, the level spectroscopy analysis of the results
obtained by the exact diagonalization method and also the density-matrix
renormalization-group method. It is found that the non-collinear ferrimagnetic
(NCFR) state appears as the ground state in the frustrated region of the
parameters. Furthermore, the direct-product triplet-dimer (TD) state in which
all rungs form the TD pair is the exact ground state, when $J_{{\rm
l},a}\!+\!J_{{\rm l},b}\!=\!0$ and $0 \leq \Delta \leq 0.83$. The obtained
phase diagrams consist of the TD, $XY$ and Haldane phases as well as the NCFR
phase.


title: Gate-Tuned Thermoelectric Power in Black Phosphorus

abstract:
  The electric field effect is a useful means of elucidating intrinsic material
properties as well as for designing functional devices. The
electric-double-layer transistor (EDLT) enables the control of carrier density
in a wide range, which is recently proved to be an effective tool for the
investigation of thermoelectric properties. Here, we report the gate-tuning of
thermoelectric power in a black phosphorus (BP) single crystal flake with the
thickness of 40 nm. Using an EDLT configuration, we successfully control the
thermoelectric power (S), and find that the S of ion-gated BP reached +510
$\mu$V/K at 210 K in the hole depleted state, which is much higher than the
reported bulk single crystal value of +340 $\mu$V/K at 300 K. We compared this
experimental data with the first-principles-based calculation and found that
this enhancement is qualitatively explained by the effective thinning of the
conduction channel of the BP flake and non-uniformity of the channel owing to
the gate operation in a depletion mode. Our results provide new opportunities
for further engineering BP as a thermoelectric material in nanoscale.


title:
A numerical solution of one class of Volterra integral equations of the
  first kind in terms of the machine arithmetic features

abstract:
  The research is devoted to a numerical solution of the Volterra equations of
the first kind that were obtained using the Laplace integral transforms for
solving the equation of heat conduction. The paper consists of an introduction
and two sections. The first section deals with the calculation of kernels from
the respective integral equations at a fixed length of the significand in the
floating point representation of a real number. The PASCAL language was used to
develop the software for the calculation of kernels, which implements the
function of tracking the valid digits of the significand. The test examples
illustrate the typical cases of systematic error accumulation. The second
section presents the results obtained from the computational algorithms which
are based on the product integration method and the midpoint rule. The results
of test calculations are presented to demonstrate the performance of the
difference methods.


title:
Testing for high-dimensional white noise using maximum
  cross-correlations

abstract:
  We propose a new omnibus test for vector white noise using the maximum
absolute auto-correlations and cross-correlations of the component series.
Based on the newly established approximation by the $L_\infty$-norm of a normal
random vector, the critical value of the test can be evaluated by bootstrapping
from a multivariate normal distribution. In contrast to the conventional white
noise test, the new method is proved to be valid for testing the departure from
non-IID white noise. We illustrate the accuracy and the power of the proposed
test by simulation, which also shows that the new test outperforms several
commonly used methods including, for example, the Lagrange multiplier test and
the multivariate Box-Pierce portmanteau tests especially when the dimension of
time series is high in relation to the sample size. The numerical results also
indicate that the performance of the new test can be further enhanced when it
is applied to the pre-transformed data obtained via the time series principal
component analysis proposed by Chang, Guo and Yao (2014). The proposed
procedures have been implemented in an R-package HDtest and is available online
at CRAN.


title: Arbitrage and utility maximization in market models with an insider

abstract:
  We study arbitrage opportunities, market viability and utility maximization
in market models with an insider. Assuming that an economic agent possesses
from the beginning an additional information in the form of a random variable
G, which only becomes known to the ordinary agents at date T, we give criteria
for the No Unbounded Profits with Bounded Risk property to hold, characterize
optimal arbitrage strategies, and prove duality results for the utility
maximization problem faced by the insider. Examples of markets satisfying NUPBR
yet admitting arbitrage opportunities are provided for both atomic and
continuous random variables G.


title:
Incomplete Phase-Space Method to Reveal Time Delay From Scalar
  Time-series

abstract:
  A computationally quick and conceptually simple method to recover time delay
of the chaotic system from scalar time series is developed in this paper. We
show that the orbits in the incomplete two-dimensional reconstructed
phase-space will show local clustering phenomenon after the component
permutation procedure proposed in this work. We find that information captured
by the incomplete two-dimensional reconstructed phase-space, is related to the
time delay ${\tau _0}$ present in the system, and will be transferred to the
permutation component by the procedure of component permutation. We then
propose the segmented mean-variance (SMV) from the permutation component to
identify the time delay ${\tau _0}$ of the system. The proposed SMV shows clear
maximum when the embedding delay $\tau $ of the incomplete reconstruction
matches the time delay ${\tau _0}$ of the chaotic system. Numerical data
generated by a time-delay system based on the Mackey-Glass equation operating
in the chaotic regime are used to illustrate the effectiveness of the proposed
SMV. Experimental results show that the proposed SMV is robust to additive
observational noise and is able to recover the time delay of the chaotic system
even though the amount of data is relatively small and the feedback strength is
weak. Moreover, the time complexity of the proposed method is quite low.


title:
The HII Galaxy Hubble Diagram Strongly Favors $R_{\rm h}=ct$ over
  $\Lambda$CDM

abstract:
  We continue to build support for the proposal to use HII galaxies (HIIGx) and
giant extragalactic HII regions (GEHR) as standard candles to construct the
Hubble diagram at redshifts beyond the current reach of Type Ia supernovae.
Using a sample of 25 high-redshift HIIGx, 107 local HIIGx, and 24 GEHR, we
confirm that the correlation between the emission-line luminosity and
ionized-gas velocity dispersion is a viable luminosity indicator, and use it to
test and compare the standard model $\Lambda$CDM and the $R_{\rm h}=ct$
Universe by optimizing the parameters in each cosmology using a maximization of
the likelihood function. For the flat $\Lambda$CDM model, the best fit is
obtained with $\Omega_{\rm m}= 0.40_{-0.09}^{+0.09}$. However, statistical
tools, such as the Akaike (AIC), Kullback (KIC) and Bayes (BIC) Information
Criteria favor $R_{\rm h}=ct$ over the standard model with a likelihood of
$\approx 94.8\%-98.8\%$ versus only $\approx 1.2\%-5.2\%$. For $w$CDM (the
version of $\Lambda$CDM with a dark-energy equation of state $w_{\rm de}\equiv
p_{\rm de}/\rho_{\rm de}$ rather than $w_{\rm de}=w_{\Lambda}=-1$), a
statistically acceptable fit is realized with $\Omega_{\rm
m}=0.22_{-0.14}^{+0.16}$ and $w_{\rm de}= -0.51_{-0.25}^{+0.15}$ which,
however, are not fully consistent with their concordance values. In this case,
$w$CDM has two more free parameters than $R_{\rm h}=ct$, and is penalized more
heavily by these criteria. We find that $R_{\rm h}=ct$ is strongly favored over
$w$CDM with a likelihood of $\approx 92.9\%-99.6\%$ versus only $0.4\%-7.1\%$.
The current HIIGx sample is already large enough for the BIC to rule out
$\Lambda$CDM/$w$CDM in favor of $R_{\rm h}=ct$ at a confidence level
approaching $3\sigma$.


title: Transferring Knowledge from Text to Predict Disease Onset

abstract:
  In many domains such as medicine, training data is in short supply. In such
cases, external knowledge is often helpful in building predictive models. We
propose a novel method to incorporate publicly available domain expertise to
build accurate models. Specifically, we use word2vec models trained on a
domain-specific corpus to estimate the relevance of each feature's text
description to the prediction problem. We use these relevance estimates to
rescale the features, causing more important features to experience weaker
regularization.
  We apply our method to predict the onset of five chronic diseases in the next
five years in two genders and two age groups. Our rescaling approach improves
the accuracy of the model, particularly when there are few positive examples.
Furthermore, our method selects 60% fewer features, easing interpretation by
physicians. Our method is applicable to other domains where feature and outcome
descriptions are available.


title:
Combined effect of horizontal magnetic field and vorticity on Rayleigh
  Taylor instability

abstract:
  In this research, the height, curvature and velocity of the bubble tip in
Rayleigh-Taylor instability at arbitrary Atwood number with horizontal magnetic
field are investigated. To support the earlier simulation and experimental
results, the vorticity generation inside the bubble is introduced. It is found
that, in early nonlinear stage, the temporal evolution of the bubble tip
parameters depend essentially on the strength and initial perturbation of the
magnetic field, although the asymptotic nature coincides with the non magnetic
case. The model proposed here agrees with the previous linear, nonlinear and
simulation observations.


title:
Determination of magic wavelengths for the $7s ~ {^2}S_{1/2}-7p ~
  {^2}P_{3/2,1/2}$ transitions in Fr atom

abstract:
  Magic wavelengthsfor the $7S_{1/2}-7P_{1/2,3/2}$ transitions in Fr were
reported by Dammalapati \textit{et al.} in [Phys. Rev. A 93, 043407 (2016)].
These $\lambda_{\rm{magic}}$ were determined by plotting dynamic
polarizabilities ($\alpha$) of the involved states with the above transitions
against a desired range of wavelength. Electric dipole (E1) matrix elements
listed in [J. Phys. Chem. Ref. Data 36, 497 (2007)], from the measured
lifetimes of the $7P_{1/2,3/2}$ states and from the calculations considering
core-polarization effects in the relativistic Hartree-Fock (HFR) method, were
used to determine $\alpha$. However, contributions from core correlation
effects and from the E1 matrix elements of the $7P-7S$, $7P-8S$ and $7P-6D$
transitions to $\alpha$ of the $7P$ states were ignored. In this work, we
demonstrate importance of these contributions and improve accuracies of
$\alpha$ further by replacing the E1 matrix elements taken from the HFR method
by the values obtained employing relativistic coupled-cluster theory. Our
static $\alpha$ are found to be in excellent agreement with the other available
theoretical results; whereas substituting the E1 matrix elements used by
Dammalapati \textit{et al.} give very small $\alpha$ values for the $7P$
states. Owing to this, we find disagreement in $\lambda_{\rm{magic}}$ reported
by Dammalapati \textit{et al.} for linearly polarized light; especially at
wavelengths close to the D-lines and in the infrared region. As a consequence,
a $\lambda_{\rm{magic}}$ reported at 797.75 nm which was seen supporting a blue
detuned trap in their work is now estimated at 771.03 nm and is supporting a
red detuned trap. Also, none of our results match with the earlier results for
circularly polarized light. Moreover, our static values of $\alpha$ will be
very useful for guiding experiments to carry out their measurements.


title:
Regularity of the $3D$ stationary Hall magnetohydrodynamic equations on
  the plane

abstract:
  We study the regularity of weak solutions to the 3D valued stationary Hall
magnetohydrodynamic equations on $ \Bbb R^2$. We prove that every weak solution
is smooth. Furthermore, we prove a Liouville type theorem for the Hall
equations.


title: Fission fragment mass distributions in reactions populating 200Pb

abstract:
  The fission fragment mass distributions have been measured in the reactions
16O + 184W and 19F+ 181Ta populating the same compound nucleus 200Pb? at
similar excitation energies. It is found that the widths of the mass
distribution increases monotonically with excitation energy, indicating the
absence of quasi-fission for both reactions. This is contrary to two recent
claims of the presence of quasi-fission in the above mentioned reactions.


title: Bi-directional Attention with Agreement for Dependency Parsing

abstract:
  We develop a novel bi-directional attention model for dependency parsing,
which learns to agree on headword predictions from the forward and backward
parsing directions. The parsing procedure for each direction is formulated as
sequentially querying the memory component that stores continuous headword
embeddings. The proposed parser makes use of {\it soft} headword embeddings,
allowing the model to implicitly capture high-order parsing history without
dramatically increasing the computational complexity. We conduct experiments on
English, Chinese, and 12 other languages from the CoNLL 2006 shared task,
showing that the proposed model achieves state-of-the-art unlabeled attachment
scores on 6 languages.


title:
Virasoro constraints and polynomial recursion for the linear Hodge
  integrals

abstract:
  The Hodge tau-function is a generating function for the linear Hodge
integrals. It is also a tau-function of the KP hierarchy. In this paper, we
first present the Virasoro constraints for the Hodge tau-function in the
explicit form of the Virasoro equations. The expression of our Virasoro
constraints is simply a linear combination of the Virasoro operators, where the
coefficients are restored from a power series for the Lambert W function. Then,
using this result, we deduce a simple version of the Virasoro constraints for
the linear Hodge partition function, where the coefficients are restored from
the Gamma function. Finally, we establish the equivalence relation between the
Virasoro constraints and polynomial recursion formula for the linear Hodge
integrals.


title: Strangeness in Neutron Star Cooling

abstract:
  We study the thermal evolution of neutron stars in the presence of hyperons
or kaons in the core. Our results indicate that the nucleon and hyperon direct
Urca processes play crucial roles for the cooling of neutron stars. The
presence of hyperons drives fast cooling mechanisms in two ways: 1) it allows
the hyperon direct Urca prior to the nucleon direct Urca, 2) and it makes the
nucleon direct Urca more feasible by reducing the neutron Fermi momentum. We
found that the neutron star equation of state (EOS) with hyperons can be
consistent with both mass and temperature observations. We also found that the
neutron star EOS with kaon condensation can be consistent with observations,
even though the cooling behavior is seldom useful to identify or isolate the
effect of kaon condensation.


title:
Probing the environment of gravitational wave transient sources with TeV
  afterglow emission

abstract:
  Recently, Advanced Laser Interferometer Gravitational-wave Observatory
(aLIGO) detected gravitational wave (GW) transients from mergers of binary
black holes (BHs). The system may also produce a wide-angle, relativistic
outflow if the claimed short GRB detected by GBM is in real association with GW
150914. It was suggested that mergers of double neutron stars (or neutron
star-black hole binaries), another promising source of GW transients, also
produce fast, wide-angle outflows. In this paper, we calculate the high-energy
gamma-ray emission arising from the blast waves driven by these wide-angle
outflows. We find that TeV emission arising from the inverse-Compton process in
the relativistic outflow resulted from mergers of binary BHs similar to those
in GW 150914 could be detectable by ground-based IACT telescopes such as
Cherenkov Telescope Array (CTA) if the sources occur in { a dense medium with
density $n > 0.3 cm^{-3}$}. For neutron star-neutron star (NS-NS) and NS-BH
mergers, TeV emission from the wide-angle, mildly-relativistic outflow could be
detected as well if they occur in a dense medium {with $n > 10-100 cm^{-3}$.}
Thus TeV afterglow emission would be a useful probe of the environment of the
GW transients, which could shed light on the evolution channels of the
progenitors of GW transients.


title: Triple point in the $O(2)$ ghost model with higher-order gradient term

abstract:
  The phase structure and the infrared behaviour of the Euclidean 3-dimensional
$O(2)$ symmetric ghost scalar field $\phi$ has been investigated in Wegner and
Houghton's renormalization group framework, including higher-derivatives in the
kinetic term. It is pointed out that higher-derivative coupling provides three
phases and leads to a triple point in that RG scheme. The types of the phase
transitions have also been identified.


title: Pointed computations and Martin-L\"of randomness

abstract:
  Schnorr showed that a real is Martin-Loef random if and only if all of its
initial segments are incompressible with respect to prefix-free complexity.
Fortnow and independently Nies, Stephan and Terwijn noticed that this statement
remains true if we can merely require that the initial segments of the real
corresponding to a computable increasing sequence of lengths are
incompressible. The purpose of this note is to establish the following
generalization of this fact. We show that a real is X Martin-Loef random if and
only if its initial segments corresponding to a pointedly X-computable sequence
(r_n) (where r_n is computable from X in a self-delimiting way, so that at most
the first r_n bits of X are queried in the computation) of lengths are
incompressible. On the other hand we also show that there are reals which are
very far from being Martin-Loef random, yet they compute an increasing sequence
of lengths at which their initial segments are incompressible.


title: COREALMLIB: An ALM Library Translated from the Component Library

abstract:
  This paper presents COREALMLIB, an ALM library of commonsense knowledge about
dynamic domains. The library was obtained by translating part of the COMPONENT
LIBRARY (CLIB) into the modular action language ALM. CLIB consists of general
reusable and composable commonsense concepts, selected based on a thorough
study of ontological and lexical resources. Our translation targets CLIB states
(i.e., fluents) and actions. The resulting ALM library contains the
descriptions of 123 action classes grouped into 43 reusable modules that are
organized into a hierarchy. It is made available online and of interest to
researchers in the action language, answer-set programming, and natural
language understanding communities. We believe that our translation has two
main advantages over its CLIB counterpart: (i) it specifies axioms about
actions in a more elaboration tolerant and readable way, and (ii) it can be
seamlessly integrated with ASP reasoning algorithms (e.g., for planning and
postdiction). In contrast, axioms are described in CLIB using STRIPS-like
operators, and CLIB's inference engine cannot handle planning nor postdiction.
Under consideration for publication in TPLP.


title: Rare events in stochastic populations under bursty reproduction

abstract:
  Recently, a first step was made by the authors towards a systematic
investigation of the effect of reaction-step-size noise - uncertainty in the
step size of the reaction - on the dynamics of stochastic populations. This was
done by investigating the effect of bursty influx on the switching dynamics of
stochastic populations. Here we extend this formalism to account for bursty
reproduction processes, and improve the accuracy of the formalism to include
subleading-order corrections. Bursty reproduction appears in various contexts,
where notable examples include bursty viral production from infected cells, and
reproduction of mammals involving varying number of offspring. The main
question we quantitatively address is how bursty reproduction affects the
overall fate of the population. We consider two complementary scenarios:
population extinction and population survival; in the former a population gets
extinct after maintaining a long-lived metastable state, whereas in the latter
a population proliferates despite undergoing a deterministic drift towards
extinction. In both models reproduction occurs in bursts, sampled from an
arbitrary distribution. In the extinction problem, we show that bursty
reproduction broadens the quasi-stationary distribution of population sizes in
the metastable state, which results in an exponential decrease of the mean time
to extinction. In the survival problem, bursty reproduction yields an
exponential increase in survival probability of the population. Close to the
bifurcation limit our analytical results simplify considerably and are shown to
depend solely on the mean and variance of the burst-size distribution. Our
formalism is demonstrated on several realistic distributions which all compare
well with numerical Monte-Carlo simulations.


title: Gerstenhaber-Schack Cohomology for Hom-bialgebras and Deformations

abstract:
  Hom-bialgebras and Hom-Hopf algebras are generalizations of bialgebra and
Hopf algebra structures, where associativity and coassociativity conditions are
twisted by a homomorphism. The purpose of this paper is to define a
Gerstenhaber-Schack cohomology complex for Hom-bialgebras and then study one
parameter formal deformations.


title:
An axiomatizable profinite group with infinitely many open subgroups of
  index 2

abstract:
  We show that a profinite group with the same first-order theory as the direct
product over all odd primes $p$ of the dihedral group of order $2p$, is
necessarily isomorphic to this direct product.


title: $C^*$-algebras generated by the paths semigroup

abstract:
  In this paper we study the structure of the $C^*$-algebra, generated by the
representation of the paths semigroup on a partially ordered set (poset) and
get the net of isomorphic $C^*$-algebras over this poset. We construct the
extensions of this algebra, such that the algebra is an ideal in that
extensions and quotient algebras are isomorphic to the Cuntz algebra.


title: Embedding graphs into embedded graphs

abstract:
  A (possibly denerate) drawing of a graph $G$ in the plane is approximable by
an embedding if it can be turned into an embedding by an arbitrarily small
perturbation. We show that testing, whether a straight-line drawing of a planar
graph $G$ in the plane is approximable by an embedding, can be carried out in
polynomial time, if a desired embedding of $G$ belongs to a fixed isotopy
class. In other words, we show that c-planarity with embedded pipes is
tractable for graphs with fixed embeddings.
  To the best of our knowledge an analogous result was previously known
essentially only when $G$ is a cycle.


title:
Evolution of intermediate-mass X-ray binaries driven by magnetic braking
  of Ap/Bp stars: I. ultracompact X-ray binaries

abstract:
  It is generally believed that Ultracompact X-ray binaries (UCXBs) evolved
from binaries consisting of a neutron star accreting from a low-mass white
dwarf or helium star where mass transfer is driven by gravitational radiation.
However, the standard white-dwarf evolutionary channel cannot produce the
relatively long-period ($40 - 60$\,min) UCXBs with high time-averaged
mass-transfer rate. In this work, we explore an alternative evolutionary route
toward UCXBs where the companions evolve from intermediate-mass Ap/Bp stars
with an anomalously strong magnetic field ($100 - 10000$\,G). Including the
magnetic braking caused by the coupling between the magnetic field and an
irradiation-driven wind induced by the X-ray flux from the accreting component,
we show that intermediate-mass X-ray binaries (IMXBs) can evolve into UCXBs.
Using the \emph{MESA} code, we have calculated evolutionary sequences for a
large number of IMXBs. The simulated results indicate that, for a small
wind-driving efficiency $f=10^{-5}$, the anomalous magnetic braking can drive
IMXBs to an ultra-short period of 11 min. Comparing our simulated results with
the observed parameters of fifteen identified UCXBs, the anomalous magnetic
braking evolutionary channel can account for the formation of seven and eight
sources with $f=10^{-3}$, and $10^{-5}$, respectively. In particular, a
relatively large value of $f$ can fit three of the long-period, persistent
sources with high mass-transfer rate. Though the proportion of Ap/Bp stars in
intermediate-mass stars is only 5\%, the lifetime of the UCXB phase is
$\gtrsim$ 2 Gyr, producing a relatively high number of observable systems,
making this an alternative evolutionary channel for the formation of UCXBs.


title: New efficient substepping methods for exponential timestepping

abstract:
  Exponential integrators are time stepping schemes which exactly solve the
linear part of a semilinear ODE system. This class of schemes requires the
approxima- tion of a matrix exponential in every step, and one successful
modern method is the Krylov subspace projection method. We investigate the
effect of breaking down a single timestep into arbitrary multiple substeps,
recycling the Krylov subspace to minimise costs. For these recyling based
schemes we analyse the lo- cal error, investigate them numerically and show
they can be applied to a large system with 106 unknowns. We also propose a new
second order integrator that is found using the extra information from the
substeps to form a corrector to increase the overall order of the scheme. This
scheme is seen to compare favourably with other order two integrators.


title: Dimension reduction for semidefinite programs via Jordan algebras

abstract:
  We propose a new method for simplifying semidefinite programs (SDP) inspired
by symmetry reduction. Specifically, we show if an orthogonal projection map
satisfies certain invariance conditions, restricting to its range yields an
equivalent primal-dual pair over a lower-dimensional symmetric cone---namely,
the cone-of-squares of a Jordan subalgebra of symmetric matrices. We present a
simple algorithm for minimizing the rank of this projection and hence the
dimension of this subalgebra. We also show that minimizing rank optimizes the
direct-sum decomposition of the algebra into simple ideals, yielding an optimal
"block-diagonalization" of the SDP. Finally, we give combinatorial versions of
our algorithm that execute at reduced computational cost and illustrate
effectiveness of an implementation on examples. Through the theory of Jordan
algebras, the proposed method easily extends to linear and second-order-cone
programming and, more generally, symmetric cone optimization.


title:
Second-order asymptotics on distributions of maxima of bivariate
  elliptical arrays

abstract:
  Let $\{ (\xi_{ni}, \eta_{ni}), 1\leq i \leq n, n\geq 1 \}$ be a triangular
array of independent bivariate elliptical random vectors with the same
distribution function as $(S_{1}, \rho_{n}S_{1}+\sqrt{1-\rho_{n}^2}S_{2})$,
$\rho_{n}\in (0,1)$, where $(S_{1},S_{2})$ is a bivariate spherical random
vector. For the distribution function of radius $\sqrt{S_{1}^2+S_{2}^2}$
belonging to the max-domain of attraction of the Weibull distribution, Hashorva
(2006) derived the limiting distribution of maximum of this triangular array if
convergence rate of $\rho_{n}$ to $1$ is given. In this paper, under the
refinement of the rate of convergence of $\rho_{n}$ to $1$ and the second-order
regular variation of the distributional tail of radius, precise second-order
distributional expansions of the normalized maxima of bivariate elliptical
triangular arrays are established.


title:
Computation of quasilocal effective diffusion tensors and connections to
  the mathematical theory of homogenization

abstract:
  This paper aims at bridging existing theories in numerical and analytical
homogenization. For this purpose the multiscale method of M{\aa}lqvist and
Peterseim [Math. Comp. 2014], which is based on orthogonal subspace
decomposition, is reinterpreted by means of a discrete integral operator acting
on standard finite element spaces. The exponential decay of the involved
integral kernel motivates the use of a diagonal approximation and, hence, a
localized piecewise constant coefficient. In a periodic setting, the computed
localized coefficient is proved to coincide with the classical homogenization
limit. An a priori error analysis shows that the local numerical model is
appropriate beyond the periodic setting when the localized coefficient
satisfies a certain homogenization criterion, which can be verified a
posteriori. The results are illustrated in numerical experiments.


title: Topological edge states of bound photon pairs

abstract:
  We predict the existence of interaction-driven edge states of bound
two-photon quasiparticles in a dimer periodic array of nonlinear optical
cavities. Energy spectrum of photon pairs is dramatically richer than in the
noninteracting case or in a simple lattice, featuring collapse and revival of
multiple edge and bulk modes as well as edge states in continuum. Despite the
unexpected breakdown of the Zak phase technique and the edge mixing of internal
and center-of-mass motion we link the edge state existence to the two-photon
quantum walk graph connectivity, thus uncovering the topological nature of the
many-body problem in complex lattices.


title: Desiderata for Vector-Space Word Representations

abstract:
  A plethora of vector-space representations for words is currently available,
which is growing. These consist of fixed-length vectors containing real values,
which represent a word. The result is a representation upon which the power of
many conventional information processing and data mining techniques can be
brought to bear, as long as the representations are designed with some
forethought and fit certain constraints. This paper details desiderata for the
design of vector space representations of words.


title: Construction of the unitary free fermion Segal CFT

abstract:
  In this article, we provide a detailed construction and analysis of the
mathematical conformal field theory of the free fermion, defined in the sense
of Graeme Segal. We verify directly that the operators assigned to disks with
two disks removed correspond to vertex operators, and use this to deduce
analytic properties of the vertex operators. One of the main tools used in the
construction is the Cauchy transform for Riemann surfaces, for which we
establish several properties analogous to those of the classical Cauchy
transform in the complex plane.


title:
Second Order Cone Constrained Convex Relaxations for Nonconvex
  Quadratically Constrained Quadratic Programming

abstract:
  In this paper, we present new convex relaxations for nonconvex quadratically
constrained quadratic programming (QCQP) problems. While recent research has
focused on strengthening convex relaxations using reformulation-linearization
technique (RLT), the state-of-the-art methods lose their effectiveness when
dealing with (multiple) nonconvex quadratic constraints in QCQP. In this
research, we decompose and relax each nonconvex constraint to two second order
cone (SOC) constraints and then linearize the products of the SOC constraints
and linear constraints to construct some effective new valid constraints.
Moreover, we extend the reach of the RLT-like techniques for almost all
different types of constraint-pairs (including valid inequalities by
linearizing the product of a pair of SOC constraints, and the the Hadamard
product or the Kronecker product of two respective valid linear matrix
inequalities), examine dominance relationships among different valid
inequalities, and explore almost all possibilities of gaining benefits from
generating valid constraints. Especially, we successfully demonstrate that
applying RLT-like techniques to additional redundant linear constraints could
reduce the relaxation gap. We demonstrate the efficiency of our results with
numerical experiments.


title:
Encoder-decoder with Focus-mechanism for Sequence Labelling Based Spoken
  Language Understanding

abstract:
  This paper investigates the framework of encoder-decoder with attention for
sequence labelling based spoken language understanding. We introduce
Bidirectional Long Short Term Memory - Long Short Term Memory networks
(BLSTM-LSTM) as the encoder-decoder model to fully utilize the power of deep
learning. In the sequence labelling task, the input and output sequences are
aligned word by word, while the attention mechanism cannot provide the exact
alignment. To address this limitation, we propose a novel focus mechanism for
encoder-decoder framework. Experiments on the standard ATIS dataset showed that
BLSTM-LSTM with focus mechanism defined the new state-of-the-art by
outperforming standard BLSTM and attention based encoder-decoder. Further
experiments also show that the proposed model is more robust to speech
recognition errors.


title:
Extended friction elucidates the breakdown of fast water transport in
  graphene oxide membranes

abstract:
  The understanding of water transport in graphene oxide (GO) membranes stands
out as a major theoretical problem in graphene research. Notwithstanding the
intense efforts devoted to the subject in the recent years, a consolidated
picture of water transport in GO membranes is yet to emerge. By performing
mesoscale simulations of water transport in ultrathin GO membranes, we show
that even small amounts of oxygen functionalities can lead to a dramatic drop
of the GO permeability, in line with experimental findings. The coexistence of
bulk viscous dissipation and spatially extended molecular friction results in a
major decrease of both slip and bulk flow, thereby suppressing the fast water
transport regime observed in pristine graphene nanochannels. Inspection of the
flow structure reveals an inverted curvature in the near-wall region, which
connects smoothly with a parabolic profile in the bulk region. Such inverted
curvature is a distinctive signature of the coexistence between single-particle
Langevin friction and collective hydrodynamics. The present mesoscopic model
with spatially extended friction may offer a computationally efficient tool for
future simulations of water transport in nanomaterials.


title: Isometry Classes of Planes in $(\mathbb{R}^3,d_{\infty})$

abstract:
  We determine geodesics in $\mathbb{R}_{\infty}^n$ (i.e. $(\mathbb{R}^n,
d_{\infty})$) and by using this, classify planes up to isometry in
$\mathbb{R}_{\infty}^3$.


title:
Instability of Abrikosov lattice due to nonanalytic core reconstruction
  of vortices in Bosonic superfluids

abstract:
  We study the impact of the non-analytic reconstruction of vortex cores on
static vortex structures in weakly coupled superfluids. We show that in
rotating two-dimensional systems, the Abrikosov vortex lattice is unstable to
vortex core deformation: Each zero of the wave function becomes a cut of finite
length. The directors characterizing the orientations of the cuts are
themselves ordered in superstructures due either to surface effects or to
interaction with shear deformations of the lattice (spiral structure). Similar
instability may be also observable in clean superconducting films.


title:
The energy density representation of the strangeness enhancement from
  p+p to Pb+Pb

abstract:
  The energy density is the prime parameter to define the deconfinement of
quarks and gluons occurring in collisions of heavy ions. Recently, there is
mounting evidence that many observables in proton-proton collisions behave in a
manner very similar to the one observed in heavy ions. We present as an
additional piece of evidence, a scaling of the strange particle yields as a
function of the energy density of the three collision systems: p+p p+Pb and
Pb+Pb, using the latest results of the ALICE collaboration.


title: Space-time fluctuations and a stochastic Schr\"odinger-Newton equation

abstract:
  We propose a stochastic modification of the Schr\"{o}dinger-Newton equation
which takes into account the effect of extrinsic spacetime fluctuations. We use
this equation to demonstrate gravitationally induced decoherence of two
gaussian wave-packets, and obtain a decoherence criterion similar to those
obtained in the earlier literature in the context of effects of gravity on the
Schr\"{o}dinger equation.


title:
Quasielastic production of polarized hyperons in antineutrino--nucleon
  reactions

abstract:
  We have studied the differential cross section as well as the longitudinal
and perpendicular components of polarization of final
hyperon($\Lambda$,$\Sigma$) produced in the antineutrino induced quasielastic
charged current reactions on nucleon and nuclear targets. The nucleon-hyperon
transition form factors are determined from the experimental data on
quasielastic $(\Delta S =0)$ charged current (anti)neutrino--nucleon scattering
and the semileptonic decay of neutron and hyperons assuming G--invariance,
T--invariance and SU(3) symmetry. The vector transition form factors are
obtained in terms of nucleon electromagnetic form factors for which various
parameterizations available in literature have been used. A dipole
parameterization for the axial vector form factor and the pseudoscalar
transition form factor derived in terms of axial vector form factor assuming
PCAC and GT relation extended to strangeness sector have been used in numerical
evaluations. The flux averaged cross section and polarization observables
corresponding to CERN Gargamelle experiment have been calculated for
quasielastic hyperon production and found to be in reasonable agreement with
the experimental observations. The numerical results for the flux averaged
differential cross section$\frac{d\sigma}{dQ^2}$ and
longitudinal(perpendicular) polarization $P_L(Q^2)(P_P(Q^2))$ relevant for the
antineutrino fluxes of MINER$\nu$A, MicroBooNE, and T2K experiments have been
presented. This will be useful in interpreting future experimental results on
production cross sections and polarization observables from the experiments on
the quasielastic production of hyperons induced by antineutrinos and explore
the possibility of determining the axial vector and pseudoscalar form factors
in the strangeness sector.


title: New principles for auxetic periodic design

abstract:
  We show that, for any given dimension $d\geq 2$, the range of distinct
possible designs for periodic frameworks with auxetic capabilities is infinite.
We rely on a purely geometric approach to auxetic trajectories developed within
our general theory of deformations of periodic frameworks.


title:
Electron-phonon interaction and surface effects on the optoelectronic
  properties of diamondoids: A comparative study

abstract:
  Unusual optoelectronic properties of diamondoids produce some discrepancies
between experiments and the outstanding many-body calculation outputs.
Therefore, many theoretical efforts are attracted to resolve these
inconsistencies. Here first, by combining time-dependent density functional
theory (TD-DFT) and Franck-Condon (FC) approximation, the effect of
electron-phonon (e-ph) interaction on the optical gap (OG) of the smallest
diamondoids and one of its derivatives is studied. Then, the surface effects on
the e-ph coupling and the optical properties of these structures in a
comparative manner are considered. We show that the collective motion of
carbons modifies the previous OG of adamantane predicted by TD-DFT technique.
The introduction of this effect can also fully explain the overestimated gap
predicted by the diffusion quantum Monte-Carlo (DMC) method. In addition, we
show that the chemistry of the surface is another noticeable effect that can
influence the OG renormalization and the spectral lineshape of the system.


title:
Higher-Order QCD prediction for dark matter pair associated with a b-jet
  production at the LHC

abstract:
  Dark matter associated visible particle production at high energy colliders
provides a unique way to determine the microscopic properties of the dark
matter. We investigate a pair of fermionic dark matter particles associated
with a b-jet production at the LHC, through a mediator which couples to
standard model or dark matter particles via either a vector or axial-vector
coupling. The calculation is performed by implementing these simplified models
in the FeynRules/MadGraph5 aMC@NLO framework. In our calculation,
next-to-leading order QCD corrections and parton-shower effects are considered.
We find that this process has a sizeable cross section and the QCD correction
can reach more than 2 times than LO results. We also investigate the discovery
potential in several benchmark scenarios at the 13TeV LHC.


title: A new bound for Vizing's conjecture

abstract:
  For any graph $G$, we define the power $\pi(G)$ as the minimum of the largest
number of neighbors in a $\gamma$-set of $G$, of any vertex, taken over all
$\gamma$-sets of $G$. We show that $\gamma(G\square H)\geq
\frac{\pi(G)}{2\pi(G) -1}\gamma(G)\gamma(H)$. This implies that for any graphs
$G$ and $H$, $\gamma(G\square H)\geq
\frac{\gamma(G)}{2\gamma(G)-1}\gamma(G)\gamma(H)$, and if $G$ is claw-free or
$P_4$-free, $\gamma(G\square H)\geq \frac{2}{3}\gamma(G)\gamma(H)$, where
$\gamma(G)$ is the domination number of $G$.


title: Experimental Device-Independent Tests of Classical and Quantum Entropy

abstract:
  In this paper, we report an experiment about the device-independent tests of
classical and quantum entropy based on a recent proposal [Phys. Rev. Lett. 115,
110501 (2015)], in which the states are encoded on the polarization of a
biphoton system and measured by the state tomography technology. We also
theoretically obtained the minimal quantum entropy for three widely used linear
dimension witnesses. The experimental results agree well with the theoretical
analysis, demonstrating that lower entropy is needed in quantum systems than
that in classical systems under given values of the dimension witness.


title: The critical temperature of smart meta-superconducting MgB2

abstract:
  Enhancing the critical temperature (TC) is important not only to the
practical applications but also to the theories of superconductivity. MgB2 is a
type II superconductor with a TC of 39 K, which is very close to the McMillan
limit. Improving the TC of MgB2 is challenging but significant. Inspired by the
metamaterial structure, we designed a smart meta-superconductor that consists
of MgB2 microparticles and Y2O3:Eu3+ nanorods. In the local electric field,
Y2O3:Eu3+ nanorods will generate electroluminescence (EL) that can excite MgB2
particles, thereby improving the TC by strengthening the electron-phonon
interaction. Each MgB2-based superconductor doped with one of the four dopants
of different EL intensities was prepared by an ex-situ process. The results
showed that the addition of Y2O3:Eu3+ brings about an impurity effect that
decreases the TC and an EL exciting effect that increases the TC. Apart from
the EL intensity, the micro-morphology and degree of dispersion of the dopants
also affected the TC. This smart meta-superconductor provides a new method for
increasing TC.


title: Impurity effects on BCS-BEC crossover in ultracold atomic Fermi gases

abstract:
  We present a systematic investigation of the effects of "nonmagnetic"
impurities on the $s$-wave BCS-BEC crossover in atomic Fermi gases within a
pairing fluctuation theory. Both pairing and impurity scattering $T$-matrices
are treated self-consistently at the same time. While the system is less
sensitive to impurity scattering in the Born limit, for strong impurity
scatterers, both the frequency and the gap function are highly renormalized,
leading to significant suppression of the superfluid $T_c$, the order parameter
and the superfluid density. We also find the formation of impurity bands and
smearing of coherence peak in the fermion density of states, leading to a
spectrum weight transfer and finite lifetime of Bogoliubov quasiparticles. In
the BCS regime, the superfluidity may be readily destroyed by the impurity of
high density. In comparison, the superfluidity in unitary and BEC regimes is
relatively more robust.


title: Bohr neighborhoods in three-fold difference sets

abstract:
  Answering a question of Hegyv\'ari and Ruzsa , we show that if A is a set of
integers having positive upper Banach density, then the set A+A-A:= {a+b-c: a,
b, c are in A} contains Bohr neighborhoods of many elements of A, where the
radius and dimension of the Bohr neighborhood depend only the upper Banach
density of A.