title:
Bypassing slip velocity: rotational and translational velocities of
  autophoretic colloids in terms of surface flux

abstract:
  A standard approach to propulsion velocities of autophoretic colloids with
thin interaction layers uses a reciprocity relation applied to the slip
velocity. But the surface flux (chemical, electrical, thermal, etc.), which is
the source of the field driving the slip is often more accessible. We show how,
under conditions of low Reynolds number and a field obeying the Laplace
equation in the outer region, the slip velocity can be bypassed in velocity
calculations. In a sense, the actual slip velocity and a normal field
proportional to the flux density are equivalent for this type of calculation.
Using known results for surface traction induced by rotating or translating an
inert particle in a quiescent fluid, we derive simple and explicit integral
formulas for translational and rotational velocities of arbitrary spheroidal
and slender-body autophoretic colloids.


title:
Asymptotic behavior of impurity-induced bound states in low-dimensional
  topological superconductors

abstract:
  We study theoretically the asymptotic behavior of the Shiba bound states
associated with magnetic impurities embedded in both 2D and 1D anomalous
superconductors. We calculate analytically the spatial dependence of the local
density of states together with the spin polarization associated with the Shiba
bound states. We show that the latter quantity exhibits drastic differences
between s-wave and different types of p-wave superconductors. Such properties,
which could be measured using spin-polarized STM, offer therefore a way to
discriminate between singlet and triplet pairing in low-dimensional
superconductors, as well as a way to estimate the amplitude of the triplet
pairing in these systems.


title: Optimal Storage Aware Caching Policies for Content-Centric Clouds

abstract:
  Caches in Content-Centric Networks (CCN) are increasingly adopting flash
memory based storage. The current flash cache technology stores all files with
the largest possible expiry date, i.e. the files are written in the memory so
that they are retained for as long as possible. This, however, does not
leverage the CCN data characteristics where content is typically short-lived
and has a distinct popularity profile. Writing files in a cache using the
longest retention time damages the memory device thus reducing its lifetime.
However, writing using a small retention time can increase the content
retrieval delay, since, at the time a file is requested, the file may already
have been expired from the memory. This motivates us to consider a joint
optimization wherein we obtain optimal policies for jointly minimizing the
content retrieval delay (which is a network-centric objective) and the flash
damage (which is a device-centric objective). Caching decisions now not only
involve what to cache but also for how long to cache each file. We design
provably optimal policies and numerically compare them against prior policies.


title: A note on stochastic Fubini's theorem and stochastic convolution

abstract:
  We provide a version of the stochastic Fubini's theorem which does not depend
on the particular stochastic integrator chosen as far as the stochastic
integration is built as a continuous linear operator from an $L^p$ space of
Banach space-valued processes (the stochastically integrable processes) to an
$L^p$ space of Banach space-valued paths (the integrated processes). Then, for
integrators on a Hilbert space $H$, we consider stochastic convolutions with
respect to a strongly continuous map $R:(0,T]\rightarrow L(H)$, not necessarily
a semigroup. We prove existence of predictable versions of stochastic
convolutions and we characterize the measurability needed by operator-valued
processes in order to be convoluted with $R$. Finally, when $R$ is a
$C_0$-semigroup and the stochastic integral provides continuous paths, we show
existence of a continuous version of the convolution, by adapting the
factorization method to the present setting.


title: Factorising the 3D Topologically Twisted Index

abstract:
  We explore the path integration -- upon the contour of hermitian
(non-auxliary) field configurations -- of topologically twisted $\mathcal{N}=2$
Chern-Simons-matter theory (TTCSM) on $\mathbb{S}_2$ times a segment. In this
way, we obtain the formula for the 3D topologically twisted index, first as a
convolution of TTCSM on $\mathbb{S}_2$ times halves of $\mathbb{S}_1$, second
as TTCSM on $\mathbb{S}_2$ times $\mathbb{S}_1$ -- with a puncture --, and
third as TTCSM on $\mathbb{S}_2 \times \mathbb{S}_1$. In contradistinction to
the first two cases, in the third case, the vector multiplet auxiliary field
$D$ is constrained to be anti-hermitian.


title: Power-free values of polynomials on symmetric varieties

abstract:
  Given a symmetric variety Y defined over the rationals and a non-zero
polynomial with integer coefficients, we use techniques from homogeneous
dynamics to establish conditions under which the polynomial can be made r-free
for a Zariski dense set of integral points on Y. We also establish an
asymptotic counting formula for this set. In the special case that Y is a
quadric hypersurface, we give explicit bounds on the size of r by combining the
argument with a uniform upper bound for the density of integral points on
general affine quadrics.


title: Twitter as a Source of Global Mobility Patterns for Social Good

abstract:
  Data on human spatial distribution and movement is essential for
understanding and analyzing social systems. However existing sources for this
data are lacking in various ways; difficult to access, biased, have poor
geographical or temporal resolution, or are significantly delayed. In this
paper, we describe how geolocation data from Twitter can be used to estimate
global mobility patterns and address these shortcomings. These findings will
inform how this novel data source can be harnessed to address humanitarian and
development efforts.


title:
Two-loop Bhabha Scattering at High Energy beyond Leading Power
  Approximation

abstract:
  We evaluate the two-loop ${\cal O}(m_e^2/s)$ contribution to the wide-angle
high-energy electron-positron scattering in the double-logarithmic
approximation. The origin and the general structure of the power-suppressed
double logarithmic corrections are discussed in detail.


title:
Domains and ferroelectric switching pathways in Ca$_3$Ti$_2$O$_7$ from
  first principles

abstract:
  Hybrid improper ferroelectricity, where an electrical polarization can be
induced via a trilinear coupling to two non-polar structural distortions of
different symmetry, has recently been experimentally demonstrated for the first
time in the $n$=2 Ruddlesden-Popper compound Ca$_3$Ti$_2$O$_7$. In this paper
we use group theoretic methods and first-principles calculations to identify
possible ferroelectric switching pathways in Ca$_3$Ti$_2$O$_7$. We identify
low-energy paths that reverse the polarization direction by switching via an
orthorhombic twin domain, or via an antipolar structure. We also introduce a
chemically intuitive set of local order parameters to give insight into how
these paths are relevant to switching nucleated at domain walls. Our findings
suggest that switching may proceed via more than one mechanism in this
material.


title:
On nonequivalence of regular boundary points for second-order elliptic
  operators

abstract:
  In this paper we present examples of nondivergence form second order elliptic
operators with continuous coefficients such that $L$ has an irregular boundary
point that is regular for the Laplacian. Also for any eigenvalue spread <1 of
the matrix of the coefficients we provide an example of operator with
discontinuous coefficients that has regular boundary points nonequivalent to
Laplacian's (we give examples for each direction of nonequivalence).
  All examples are constructed for each dimension starting with 3.


title:
Comparing the suitability of Lithium ion, Lithium Sulfur and Lithium air
  batteries for current and future vehicular applications

abstract:
  In this report, future performance demands of batteries for various vehicular
applications are modeled. Vehicles ranging in size from electric bikes to heavy
trucks are assessed using driving cycle data which allows key performance
parameters such as desired range (km), specific energy of the battery (Wh/Kg),
cycle life requirement and expected price per unit capacity (Euro/kWh) to be
calculated. These projected performance requirements are compared with the
outputs for three existing Li-ion batteries (namely (a) Kokam based high
specific energy source (b) A123 based high power energy source and (c) Winston
low cost system). The theoretical, current state of the art and projected
performance parameters for 'beyond Li-ion' technologies (Li-S and Li-O2) are
also compared to the modeled battery performance demands. The analysis
indicates that current battery technologies are unlikely to meet future
requirements in terms of required specific energies and will likely be too
costly. In comparison, fully realized beyond Li-ion alternatives may deliver
the required specific energy for the full range of vehicles examined. However,
scale-up of these systems is a daunting challenge and their successful
implementation will depend on improvements in terms of cycle life, electrode
and electrolyte stability, rate performance and development of practical
battery architectures.


title: Aspects of perturbative unitarity

abstract:
  We reconsider perturbative unitarity in quantum field theory and upgrade
several arguments and results. The minimum assumptions that lead to the largest
time equation, the cutting equations and the unitarity equation are identified.
Using this knowledge and a special gauge, we give a new, simpler proof of
perturbative unitarity in gauge theories and generalize it to quantum gravity,
in four and higher dimensions. The special gauge interpolates between the
Feynman gauge and the Coulomb gauge without double poles. When the Coulomb
limit is approached, the unphysical particles drop out of the cuts and the
cutting equations are consistently projected onto the physical subspace. The
proof does not extend to nonlocal quantum field theories of gauge fields and
gravity, whose unitarity remains uncertain.


title: Integrability of motion around galactic razor-thin disks

abstract:
  We consider the three-dimensional bounded motion of a test particle around
razor-thin disk configurations, by focusing on the adiabatic invariance of the
vertical action associated with disk-crossing orbits. We find that it leads to
an approximate third integral of motion predicting envelopes of the form
$Z(R)\propto[\Sigma(R)]^{-1/3}$, where $R$ is the radial galactocentric
coordinate, $Z$ is the z-amplitude (vertical amplitude) of the orbit and
$\Sigma$ represents the surface mass density of the thin disk. This third
integral, which was previously formulated for the case of flattened 3D
configurations, is tested for a variety of trajectories in different thin-disk
models.


title: Chemical freeze-out conditions in hadron resonance gas

abstract:
  The hadron resonance gas model with hadron-type dependent eigenvolume
corrections is employed to fit the hadron yield data of the NA49 collaboration
for central Pb+Pb collisions at the c.m. energy per nucleon pair Ecm=6.3, 7.6,
8.8, 12.3, and 17.3 GeV, the hadron midrapidity yield data of the STAR
collaboration for Au+Au collisions at Ecm=200 GeV, and the hadron midrapidity
yield data of the ALICE collaboration for Pb+Pb collisions at Ecm=2760 GeV. The
influence of the eigenvolume corrections is studied.


title: Geometric MCMC for Infinite-Dimensional Inverse Problems

abstract:
  Bayesian inverse problems often involve sampling posterior distributions on
infinite-dimensional function spaces. Traditional Markov chain Monte Carlo
(MCMC) algorithms are characterized by deteriorating mixing times upon
mesh-refinement, when the finite-dimensional approximations become more
accurate. Such methods are typically forced to reduce step-sizes as the
discretization gets finer, and thus are expensive as a function of dimension.
Recently, a new class of MCMC methods with mesh-independent convergence times
has emerged. However, few of them take into account the geometry of the
posterior informed by the data. At the same time, recently developed geometric
MCMC algorithms have been found to be powerful in exploring complicated
distributions that deviate significantly from elliptic Gaussian laws, but are
in general computationally intractable for models defined in infinite
dimensions. In this work, we combine geometric methods on a finite-dimensional
subspace with mesh-independent infinite-dimensional approaches. Our objective
is to speed up MCMC mixing times, without significantly increasing the
computational cost per step (for instance, in comparison with the vanilla
preconditioned Crank-Nicolson (pCN) method). This is achieved by using ideas
from geometric MCMC to probe the complex structure of an intrinsic
finite-dimensional subspace where most data information concentrates, while
retaining robust mixing times as the dimension grows by using pCN-like methods
in the complementary subspace. The resulting algorithms are demonstrated in the
context of three challenging inverse problems arising in subsurface flow, heat
conduction and incompressible flow control. The algorithms exhibit up to two
orders of magnitude improvement in sampling efficiency when compared with the
pCN method.


title: Visualizing textual models with in-text and word-as-pixel highlighting

abstract:
  We explore two techniques which use color to make sense of statistical text
models. One method uses in-text annotations to illustrate a model's view of
particular tokens in particular documents. Another uses a high-level,
"words-as-pixels" graphic to display an entire corpus. Together, these methods
offer both zoomed-in and zoomed-out perspectives into a model's understanding
of text. We show how these interconnected methods help diagnose a classifier's
poor performance on Twitter slang, and make sense of a topic model on
historical political texts.


title: Scott sentences for certain groups

abstract:
  We give Scott sentences for certain computable groups, and we use index set
calculations as a way of checking that our Scott sentences are as simple as
possible. We consider finitely generated groups and torsion-free abelian groups
of finite rank. For both kinds of groups, the computable ones all have
computable $\Sigma_3$ Scott sentences. Sometimes we can do better. In fact, the
computable finitely generated groups that we have studied all have Scott
sentences that are "computable $d$-$\Sigma_2$" (the conjunction of a computable
$\Sigma_2$ sentence and a computable $\Pi_2$ sentence). This was already shown
for the finitely generated free groups. Here we show it for all finitely
generated abelian groups, and for the infinite dihedral group. Among the
computable torsion-free abelian groups of finite rank, we focus on those of
rank $1$. These are exactly the additive subgroups of $\mathbb{Q}$. We show
that for some of these groups, the computable $\Sigma_3$ Scott sentence is best
possible, while for others, there is a computable $d$-$\Sigma_2$ Scott
sentence.


title: Multiple Instance Hyperspectral Target Characterization

abstract:
  In this paper, two methods for multiple instance target characterization,
MI-SMF and MI-ACE, are presented. MI-SMF and MI-ACE estimate a discriminative
target signature from imprecisely-labeled and mixed training data. In many
applications, such as sub-pixel target detection in remotely-sensed
hyperspectral imagery, accurate pixel-level labels on training data is often
unavailable and infeasible to obtain. Furthermore, since sub-pixel targets are
smaller in size than the resolution of a single pixel, training data is
comprised only of mixed data points (in which target training points are
mixtures of responses from both target and non-target classes). Results show
improved, consistent performance over existing multiple instance concept
learning methods on several hyperspectral sub-pixel target detection problems.


title:
A Hierarchical Reinforcement Learning Method for Persistent
  Time-Sensitive Tasks

abstract:
  Reinforcement learning has been applied to many interesting problems such as
the famous TD-gammon and the inverted helicopter flight. However, little effort
has been put into developing methods to learn policies for complex persistent
tasks and tasks that are time-sensitive. In this paper, we take a step towards
solving this problem by using signal temporal logic (STL) as task
specification, and taking advantage of the temporal abstraction feature that
the options framework provide. We show via simulation that a relatively easy to
implement algorithm that combines STL and options can learn a satisfactory
policy with a small number of training cases


title:
Bots, #StrongerIn, and #Brexit: Computational Propaganda during the
  UK-EU Referendum

abstract:
  Bots are social media accounts that automate interaction with other users,
and they are active on the StrongerIn-Brexit conversation happening over
Twitter. These automated scripts generate content through these platforms and
then interact with people. Political bots are automated accounts that are
particularly active on public policy issues, elections, and political crises.
In this preliminary study on the use of political bots during the UK referendum
on EU membership, we analyze the tweeting patterns for both human users and
bots. We find that political bots have a small but strategic role in the
referendum conversations: (1) the family of hashtags associated with the
argument for leaving the EU dominates, (2) different perspectives on the issue
utilize different levels of automation, and (3) less than 1 percent of sampled
accounts generate almost a third of all the messages.


title: Complex Embeddings for Simple Link Prediction

abstract:
  In statistical relational learning, the link prediction problem is key to
automatically understand the structure of large knowledge bases. As in previous
studies, we propose to solve this problem through latent factorization.
However, here we make use of complex valued embeddings. The composition of
complex embeddings can handle a large variety of binary relations, among them
symmetric and antisymmetric relations. Compared to state-of-the-art models such
as Neural Tensor Network and Holographic Embeddings, our approach based on
complex embeddings is arguably simpler, as it only uses the Hermitian dot
product, the complex counterpart of the standard dot product between real
vectors. Our approach is scalable to large datasets as it remains linear in
both space and time, while consistently outperforming alternative approaches on
standard link prediction benchmarks.


title:
High Resolution Nonperturbative Light-Front Simulations of the True
  Muonium Atom

abstract:
  Through the development of a parallel code called TMSWIFT, an extensive
light-front quantization study of the nonperturbative spectrum of the bound
state $(\mu^+\mu^-)$, true muonium, has been performed. Using Pad\'{e}
approximants, it has been possible to extract continuum and infinite-cutoff
limits for the singlet and triplet states for a range of values of the coupling
constant $\alpha$. This data set allows for an investigation of the $\alpha$
dependence of the light-front spectra, the results of which are compared to
standard calculations. Decay constants have also been obtained. Improved
calculations have been undertaken for the energy shifts due to the presence of
a second, lighter flavor ($e$). Finally, initial results for three-flavor ($e$,
$\mu$, $\tau$) calculations are presented.


title:
Boundary-induced dynamics in 1D topological systems and memory effects
  of edge modes

abstract:
  Dynamics induced by a change of boundary conditions reveals rate-dependent
signatures associated with topological properties in one-dimensional Kitaev
chain and SSH model. While the perturbation from a change of the boundary
propagates into the bulk, the density of topological edge modes in the case of
transforming to open boundary condition reaches steady states. The steady-state
density depends on the transformation rate of the boundary and serves as an
illustration of quantum memory effects in topological systems. Moreover, while
a link is physically broken as the boundary condition changes, some correlation
functions can remain finite across the broken link and keep a record of the
initial condition. By testing those phenomena in the non-topological regimes of
the two models, none of the interesting signatures of memory effects can be
observed. Our results thus contrast the importance of topological properties in
boundary-induced dynamics.


title: Twisted Alexander polynomials of hyperbolic links

abstract:
  In this paper we apply the twisted Alexander polynomial to study the fibering
and genus detecting problems for oriented links. In particular we generalize a
conjecture of Dunfield, Friedl and Jackson on the torsion polynomial of
hyperbolic knots to hyperbolic links, and confirm it for an infinite family of
hyperbolic 2-bridge links. Moreover we consider a similar problem for parabolic
representations of 2-bridge link groups.


title: A Probabilistic Generative Grammar for Semantic Parsing

abstract:
  Domain-general semantic parsing is a long-standing goal in natural language
processing, where the semantic parser is capable of robustly parsing sentences
from domains outside of which it was trained. Current approaches largely rely
on additional supervision from new domains in order to generalize to those
domains. We present a generative model of natural language utterances and
logical forms and demonstrate its application to semantic parsing. Our approach
relies on domain-independent supervision to generalize to new domains. We
derive and implement efficient algorithms for training, parsing, and sentence
generation. The work relies on a novel application of hierarchical Dirichlet
processes (HDPs) for structured prediction, which we also present in this
manuscript.
  This manuscript is an excerpt of chapter 4 from the Ph.D. thesis of Saparov
(2022), where the model plays a central role in a larger natural language
understanding system.
  This manuscript provides a new simplified and more complete presentation of
the work first introduced in Saparov, Saraswat, and Mitchell (2017). The
description and proofs of correctness of the training algorithm, parsing
algorithm, and sentence generation algorithm are much simplified in this new
presentation. We also describe the novel application of hierarchical Dirichlet
processes for structured prediction. In addition, we extend the earlier work
with a new model of word morphology, which utilizes the comprehensive
morphological data from Wiktionary.


title:
Rational torsion on the generalized Jacobian of a modular curve with
  cuspidal modulus

abstract:
  We consider the generalized Jacobian $\widetilde{J}_0(N)$ of a modular curve
$X_0(N)$ with respect to a reduced divisor given by the sum of all cusps on it.
When $N$ is a power of a prime $\geq 5$, we exhibit that the group of rational
torsion points $\widetilde{J}_0(N)(\mathbb{Q})_{\mathrm{Tor}}$ tends to be much
smaller than the classical Jacobian.


title: In situ AFM Observations of Li-Oxygen Electrochemical Reactions

abstract:
  The morphologies of crystalline lithium peroxide (Li2O2) discharge products
in Li-O2 batteries have been shown to exhibit a dependency on subtle variations
within the battery cell-operating environment including exposure to ambient
air, moisture, or additives. As a result, imaging battery discharge products in
real time under carefully controlled environmental conditions is a challenging
obstacle for complete mechanistic understanding of Li2O2 growth and deposition
during discharge in metal-air batteries. Here, we report the design of a
completely enclosed cell for high-resolution in situ AFM imaging of Li-O2
battery discharge products. The air-and moisture-free electrochemical cell
environment enabled the observation of different product morphologies during
AFM imaging when LiTFSI in oxygen-saturated tetraethylene glycol dimethyl ether
(tetraglyme) solvent was employed. This in situ AFM cell development brings
complimentary information to various proposed mechanisms for lithium oxygen
reaction.


title: Predicting Student Dropout in Higher Education

abstract:
  Each year, roughly 30% of first-year students at US baccalaureate
institutions do not return for their second year and over $9 billion is spent
educating these students. Yet, little quantitative research has analyzed the
causes and possible remedies for student attrition. Here, we describe initial
efforts to model student dropout using the largest known dataset on higher
education attrition, which tracks over 32,500 students' demographics and
transcript records at one of the nation's largest public universities. Our
results highlight several early indicators of student attrition and show that
dropout can be accurately predicted even when predictions are based on a single
term of academic transcript data. These results highlight the potential for
machine learning to have an impact on student retention and success while
pointing to several promising directions for future work.


title: Physics of the Bacon Internal Resonator Banjo

abstract:
  The internal resonator banjo, patented and first sold by Fred Bacon around
1906, remains something of a cult favorite and is still produced by some
independent luthiers. According to enthusiasts, the characteristic design
elements produce a sound that is mellower, richer, and of greater complexity
and presence than without them. Aspects of that sound are studied here,
comparing instruments that are otherwise identical and identifying physics
mechanisms that are likely responsible.


title:
FSMJ: Feature Selection with Maximum Jensen-Shannon Divergence for Text
  Categorization

abstract:
  In this paper, we present a new wrapper feature selection approach based on
Jensen-Shannon (JS) divergence, termed feature selection with maximum
JS-divergence (FSMJ), for text categorization. Unlike most existing feature
selection approaches, the proposed FSMJ approach is based on real-valued
features which provide more information for discrimination than binary-valued
features used in conventional approaches. We show that the FSMJ is a greedy
approach and the JS-divergence monotonically increases when more features are
selected. We conduct several experiments on real-life data sets, compared with
the state-of-the-art feature selection approaches for text categorization. The
superior performance of the proposed FSMJ approach demonstrates its
effectiveness and further indicates its wide potential applications on data
mining.


title:
Will Kinematic Sunyaev-Zel'dovich Measurements Enhance the Science
  Return from Galaxy Redshift Surveys?

abstract:
  Yes. Future CMB experiments such as Advanced ACTPol and CMB-S4 should achieve
measurements with S/N of $> 0.1$ for the typical galaxies in redshift surveys.
These measurements will provide complementary measurements of the growth rate
of large scale structure $f$ and the expansion rate of the Universe $H$ to
galaxy clustering measurements. This paper emphasizes that there is significant
information in the anisotropy of the relative pairwise kSZ measurements. We
expand the relative pairwise kSZ power spectrum in Legendre polynomials and
consider up to its octopole. Assuming that the noise in the filtered maps is
uncorrelated between the positions of galaxies in the survey, we derive a
simple analytic form for the power spectrum covariance of the relative pairwise
kSZ temperature in redshift space. While many previous studies have assumed
optimistically that the optical depth of the galaxies $\tau_{\rm T}$ in the
survey is known, we marginalize over $\tau_{\rm T}$, to compute constraints on
the growth rate $f$ and the expansion rate $H$. For realistic sure parameters,
we find that combining kSZ and galaxy redshift survey data reduces the
marginalized $1$-$\sigma$ errors on $H$ and $f$ by $\sim50$-$70\%$ compared to
the galaxy-only analysis.


title:
Unanimous Prediction for 100% Precision with Application to Learning
  Semantic Mappings

abstract:
  Can we train a system that, on any new input, either says "don't know" or
makes a prediction that is guaranteed to be correct? We answer the question in
the affirmative provided our model family is well-specified. Specifically, we
introduce the unanimity principle: only predict when all models consistent with
the training data predict the same output. We operationalize this principle for
semantic parsing, the task of mapping utterances to logical forms. We develop a
simple, efficient method that reasons over the infinite set of all consistent
models by only checking two of the models. We prove that our method obtains
100% precision even with a modest amount of training data from a possibly
adversarial distribution. Empirically, we demonstrate the effectiveness of our
approach on the standard GeoQuery dataset.


title: Contextual Weisfeiler-Lehman Graph Kernel For Malware Detection

abstract:
  In this paper, we propose a novel graph kernel specifically to address a
challenging problem in the field of cyber-security, namely, malware detection.
Previous research has revealed the following: (1) Graph representations of
programs are ideally suited for malware detection as they are robust against
several attacks, (2) Besides capturing topological neighbourhoods (i.e.,
structural information) from these graphs it is important to capture the
context under which the neighbourhoods are reachable to accurately detect
malicious neighbourhoods.
  We observe that state-of-the-art graph kernels, such as Weisfeiler-Lehman
kernel (WLK) capture the structural information well but fail to capture
contextual information. To address this, we develop the Contextual
Weisfeiler-Lehman kernel (CWLK) which is capable of capturing both these types
of information. We show that for the malware detection problem, CWLK is more
expressive and hence more accurate than WLK while maintaining comparable
efficiency. Through our large-scale experiments with more than 50,000
real-world Android apps, we demonstrate that CWLK outperforms two
state-of-the-art graph kernels (including WLK) and three malware detection
techniques by more than 5.27% and 4.87% F-measure, respectively, while
maintaining high efficiency. This high accuracy and efficiency make CWLK
suitable for large-scale real-world malware detection.


title: Independence and matching numbers of some token graphs

abstract:
  Let $G$ be a graph of order $n$ and let $k\in\{1,\ldots,n-1\}$. The $k$-token
graph $F_k(G)$ of $G$, is the graph whose vertices are the $k$-subsets of
$V(G)$, where two vertices are adjacent in $F_k(G)$ whenever their symmetric
difference is an edge of $G$. We study the independence and matching numbers of
$F_k(G)$. We present a tight lower bound for the matching number of $F_k(G)$
for the case in which $G$ has either a perfect matching or an almost perfect
matching. Also, we estimate the independence number for bipartite $k$-token
graphs, and determine the exact value for some graphs.


title:
Inverse source problem for time fractional diffusion with discrete
  random noise

abstract:
  In this paper, we deal with the inverse source problem of determining a
source in a time fractional diffusion equation where data are given at a fixed
time. This problem is ill-posed, i.e., the solution does not depend
continuously on the data. To regularize the instable solution, we use the
trigonometric method in nonparametric regression associated with the truncated
expansion method. We also investigate the convergence rate.


title: Neutrino masses from a pseudo-Dirac Bino

abstract:
  We show that, in $U(1)_R$-symmetric supersymmetric models, the bino and its
Dirac partner (the singlino) can play the role of right-handed neutrinos and
generate the neutrino masses and mixing, without the need for traditional
bilinear or trilinear R-parity violating operators. The two particles form a
pseudo-Dirac pair, the `bi$\nu$o'. An Inverse Seesaw texture is generated for
the neutrino-bi$\nu$o sector, and the lightest neutrino is predicted to be
massless. Unlike in most models with heavy right-handed neutrinos, the bi$\nu$o
can be sizably produced at the LHC through its interactions with colored
particles, while respecting low energy constraints from neutrinoless
double-beta decay and charged lepton flavor violation.


title: Decay and Eigenvalue Problems in Isotropic Turbulence

abstract:
  Based on the Karman-Howarth equation in 3D incompressible fluid, a new
isotropic turbulence scale evolution equation and its related theory progress.
The present results indicate that the energy cascading process has remarkable
similarities with the determinisitic construction rules of the isotonic
oscillators in quantum mechanics.


title:
An Empirical Approach to Cosmological Galaxy Survey Simulation:
  Application to SPHEREx Low-Resolution Spectroscopy

abstract:
  Highly accurate models of the galaxy population over cosmological volumes are
necessary in order to predict the performance of upcoming cosmological
missions. We present a data-driven model of the galaxy population constrained
by deep 0.1-8 $\rm \mu m$ imaging and spectroscopic data in the COSMOS survey,
with the immediate goal of simulating the spectroscopic redshift performance of
the proposed SPHEREx mission. SPHEREx will obtain over the full-sky $R\sim41$
spectrophotometry at moderate spatial resolution ($\sim6"$) over the wavelength
range 0.75-4.18 $\rm \mu m$ and $R\sim135$ over the wavelength range 4.18-5
$\rm \mu m$. We show that our simulation accurately reproduces a range of known
galaxy properties, encapsulating the full complexity of the galaxy population
and enables realistic, full end-to-end simulations to predict mission
performance. Finally, we discuss potential applications of the simulation
framework to future cosmology missions and give a description of released data
products.


title:
Diphotons at the $Z$-pole in Models of the 750 GeV Resonance Decaying to
  Axion-Like Particles

abstract:
  Models in which the 750 GeV resonance ($S$) decays to two light axion-like
particles (ALPs $a$), which in turn decay to collimated photons mimicking the
observed signal, are motivated by Hidden Valley scenarios and could also
provide a mechanism by which a $S \to \gamma \gamma$ signal persists while $S
\to Z \gamma,\; ZZ$ and $WW$ remain subdued in the near future. We point out
that these Hidden Valley like models invoking $S \to aa \to 4 \gamma$ must also
contend with $Z \to a (\to \gamma \gamma) \gamma$ constraints coming from CDF
and ATLAS. Within an effective field theory framework, we work out the
constraints on the couplings of $S$ to $a$ and gauge bosons coming from
photonic $Z$ decays and ensuring that the ALPs decay inside the electromagnetic
calorimeter, in two regimes - where $a$ decays primarily to photons, and where
$a$ also has hadronic branchings. The analysis is done for both when $S$ has a
large as well as a narrow width, and for different relative contributions to
the signal coming from $S \to \gamma \gamma$ and $a \to \gamma \gamma$. Results
for the particular case where $S$ and $a$ belong to the same complex field are
also presented. A $\gamma\gamma$ resonance at the $Z$-pole coming from $Z \to a
\gamma$ is expected in this class of models. Taking benchmark ALP masses below
around 0.4 GeV and, assuming reasonable values for the fake jet rate and the
identification efficiency of the photon-jet, we find the prospects for the
discovery of diphotons at the $Z$-pole.


title: A verified abstract machine for functional coroutines

abstract:
  Functional coroutines are a restricted form of control mechanism, where each
coroutine is represented with both a continuation and an environment. This
restriction was originally obtained by considering a constructive version of
Parigot's classical natural deduction which is sound and complete for the
Constant Domain logic. In this article, we present a refinement of de Groote's
abstract machine for functional coroutines and we prove its correctness.
Therefore, this abstract machine also provides a direct computational
interpretation of the Constant Domain logic.


title: Kernel-based Generative Learning in Distortion Feature Space

abstract:
  This paper presents a novel kernel-based generative classifier which is
defined in a distortion subspace using polynomial series expansion, named
Kernel-Distortion (KD) classifier. An iterative kernel selection algorithm is
developed to steadily improve classification performance by repeatedly removing
and adding kernels. The experimental results on character recognition
application not only show that the proposed generative classifier performs
better than many existing classifiers, but also illustrate that it has
different recognition capability compared to the state-of-the-art
discriminative classifier - deep belief network. The recognition diversity
indicates that a hybrid combination of the proposed generative classifier and
the discriminative classifier could further improve the classification
performance. Two hybrid combination methods, cascading and stacking, have been
implemented to verify the diversity and the improvement of the proposed
classifier.


title: First Class Call Stacks: Exploring Head Reduction

abstract:
  Weak-head normalization is inconsistent with functional extensionality in the
call-by-name $\lambda$-calculus. We explore this problem from a new angle via
the conflict between extensionality and effects. Leveraging ideas from work on
the $\lambda$-calculus with control, we derive and justify alternative
operational semantics and a sequence of abstract machines for performing head
reduction. Head reduction avoids the problems with weak-head reduction and
extensionality, while our operational semantics and associated abstract
machines show us how to retain weak-head reduction's ease of implementation.


title:
Answer-Type Modification without Tears: Prompt-Passing Style Translation
  for Typed Delimited-Control Operators

abstract:
  The salient feature of delimited-control operators is their ability to modify
answer types during computation. The feature, answer-type modification (ATM for
short), allows one to express various interesting programs such as typed printf
compactly and nicely, while it makes it difficult to embed these operators in
standard functional languages.
  In this paper, we present a typed translation of delimited-control operators
shift and reset with ATM into a familiar language with multi-prompt shift and
reset without ATM, which lets us use ATM in standard languages without
modifying the type system. Our translation generalizes Kiselyov's direct-style
implementation of typed printf, which uses two prompts to emulate the
modification of answer types, and passes them during computation. We prove that
our translation preserves typing. As the naive prompt-passing style translation
generates and passes many prompts even for pure terms, we show an optimized
translation that generate prompts only when needed, which is also
type-preserving. Finally, we give an implementation in the tagless-final style
which respects typing by construction.


title: From Push/Enter to Eval/Apply by Program Transformation

abstract:
  Push/enter and eval/apply are two calling conventions used in implementations
of functional languages. In this paper, we explore the following observation:
when considering functions with multiple arguments, the stack under the
push/enter and eval/apply conventions behaves similarly to two particular
implementations of the list datatype: the regular cons-list and a form of lists
with lazy concatenation respectively. Along the lines of Danvy et al.'s
functional correspondence between definitional interpreters and abstract
machines, we use this observation to transform an abstract machine that
implements push/enter into an abstract machine that implements eval/apply. We
show that our method is flexible enough to transform the push/enter Spineless
Tagless G-machine (which is the semantic core of the GHC Haskell compiler) into
its eval/apply variant.


title: A Modular Structural Operational Semantics for Delimited Continuations

abstract:
  It has been an open question as to whether the Modular Structural Operational
Semantics framework can express the dynamic semantics of call/cc. This paper
shows that it can, and furthermore, demonstrates that it can express the more
general delimited control operators control and shift.


title: Command injection attacks, continuations, and the Lambek calculus

abstract:
  This paper shows connections between command injection attacks,
continuations, and the Lambek calculus: certain command injections, such as the
tautology attack on SQL, are shown to be a form of control effect that can be
typed using the Lambek calculus, generalizing the double-negation typing of
continuations. Lambek's syntactic calculus is a logic with two implicational
connectives taking their arguments from the left and right, respectively. These
connectives describe how strings interact with their left and right contexts
when building up syntactic structures. The calculus is a form of propositional
logic without structural rules, and so a forerunner of substructural logics
like Linear Logic and Separation Logic.


title:
A singular Lambert-W Schr\"odinger potential exactly solvable in terms
  of the confluent hypergeometric functions

abstract:
  We introduce two potentials explicitly given by the Lambert-W function for
which the exact solution of the one-dimensional stationary Schr\"odinger
equation is written through the first derivative of a double-confluent Heun
function. One of these potentials is a singular potential that behaves as the
inverse square root in the vicinity of the origin and vanishes exponentially at
the infinity. The exact solution of the Schr\"odinger equation for this
potential is given through fundamental solutions each of which presents an
irreducible linear combination of two confluent hypergeometric functions. Since
the potential is effectively a short-range one it supports only a finite number
of bound states.


title: On the Herbrand content of LK

abstract:
  We present a structural representation of the Herbrand content of LK-proofs
with cuts of complexity prenex Sigma-2/Pi-2. The representation takes the form
of a typed non-deterministic tree grammar of order 2 which generates a finite
language of first-order terms that appear in the Herbrand expansions obtained
through cut-elimination. In particular, for every Gentzen-style reduction
between LK-proofs we study the induced grammars and classify the cases in which
language equality and inclusion hold.


title:
Denotational Semantics of the Simplified Lambda-Mu Calculus and a New
  Deduction System of Classical Type Theory

abstract:
  Classical (or Boolean) type theory is the type theory that allows the type
inference $\sigma \to \bot) \to \bot => \sigma$ (the type counterpart of
double-negation elimination), where $\sigma$ is any type and $\bot$ is
absurdity type. This paper first presents a denotational semantics for a
simplified version of Parigot's lambda-mu calculus, a premier example of
classical type theory. In this semantics the domain of each type is divided
into infinitely many ranks and contains not only the usual members of the type
at rank 0 but also their negative, conjunctive, and disjunctive shadows in the
higher ranks, which form an infinitely nested Boolean structure. Absurdity type
$\bot$ is identified as the type of truth values. The paper then presents a new
deduction system of classical type theory, a sequent calculus called the
classical type system (CTS), which involves the standard logical operators such
as negation, conjunction, and disjunction and thus reflects the discussed
semantic structure in a more straightforward fashion.


title: The computational content of Nonstandard Analysis

abstract:
  Kohlenbach's proof mining program deals with the extraction of effective
information from typically ineffective proofs. Proof mining has its roots in
Kreisel's pioneering work on the so-called unwinding of proofs. The proof
mining of classical mathematics is rather restricted in scope due to the
existence of sentences without computational content which are provable from
the law of excluded middle and which involve only two quantifier alternations.
By contrast, we show that the proof mining of classical Nonstandard Analysis
has a very large scope. In particular, we will observe that this scope includes
any theorem of pure Nonstandard Analysis, where `pure' means that only
nonstandard definitions (and not the epsilon-delta kind) are used. In this
note, we survey results in analysis, computability theory, and Reverse
Mathematics.


title: A note on strong normalization in classical natural deduction

abstract:
  In the context of natural deduction for propositional classical logic, with
classicality given by the inference rule reductio ad absurdum, we investigate
the De Morgan translation of disjunction in terms of negation and conjunction.
Once the translation is extended to proofs, it obtains a reduction of
provability to provability in the disjunction-free subsystem. It is natural to
ask whether a reduction is also obtained for, say, strong normalization; that
is, whether strong normalization for the disjunction-free system implies the
same property for the full system, and whether such lifting of the property can
be done along the De Morgan translation. Although natural, these questions are
neglected by the literature. We spell out the map of reduction steps induced by
the De Morgan translation of proofs. But we need to "optimize" such a map in
order to show that a reduction sequence in the full system from a proof
determines, in a length-preserving way, a reduction sequence in the
disjunction-free system from the De Morgan translation of the proof. In this
sense, the above questions have a positive answer.


title:
Efficient Spectral and Spectral Element Methods for Eigenvalue Problems
  of Schr\"{o}dinger Equations with an Inverse Square Potential

abstract:
  In this article, we study numerical approximation of eigenvalue problems of
the Schr\"{o}dinger operator $\displaystyle -\Delta u + \frac{c^2}{|x|^2}u$.
There are three stages in our investigation: We start from a ball of any
dimension, in which case the exact solution in the radial direction can be
expressed by Bessel functions of fractional degrees. This knowledge helps us to
design two novel spectral methods by modifying the polynomial basis to fit the
singularities of the eigenfunctions. At the second stage, we move to circular
sectors in the two dimensional setting. Again the radial direction can be
expressed by Bessel functions of fractional degrees. Only in the tangential
direction some modifications are needed from stage one. At the final stage, we
extend the idea to arbitrary polygonal domains. We propose a mortar spectral
element approach: a polygonal domain is decomposed into several sub-domains
with each singular corner including the origin covered by a circular sector, in
which origin and corner singularities are handled similarly as in the former
stages, and the remaining domains are either a standard quadrilateral/triangle
or a quadrilateral/triangle with a circular edge, in which the traditional
polynomial based spectral method is applied. All sub-domains are linked by
mortar elements (note that we may have hanging nodes). In all three stages,
exponential convergence rates are achieved. Numerical experiments indicate that
our new methods are superior to standard polynomial based spectral (or spectral
element) methods and $hp$-adaptive methods. Our study offers a new and
effective way to handle eigenvalue problems of the Schr\"{o}dinger operator
including the Laplacian operator on polygonal domains with reentrant corners.


title: A Linear Potential Function for Pairing Heaps

abstract:
  We present the first potential function for pairing heaps with linear range.
This implies that the runtime of a short sequence of operations is faster than
previously known. It is also simpler than the only other potential function
known to give amortized constant amortized time for insertion.


title: Weights of the mod $p$ kernel of the theta operators

abstract:
  We give some relations between the weights and the prime $p$ of elements of
the mod $p$ kernel of the generalized theta operator $\Theta ^{[j]}$. In order
to construct examples of the mod $p$ kernel of $\Theta ^{[j]}$ from any modular
form, we introduce new operators $A^{(j)}(M)$ and show the modularity of
$F|A^{(j)}(M)$ when $F$ is a modular form. Finally, we give some examples of
the mod $p$ kernel of $\Theta ^{[j]}$ and the filtrations of some of them.


title:
Phase transitions and self-organized criticality in networks of
  stochastic spiking neurons

abstract:
  Phase transitions and critical behavior are crucial issues both in
theoretical and experimental neuroscience. We report analytic and computational
results about phase transitions and self-organized criticality (SOC) in
networks with general stochastic neurons. The stochastic neuron has a firing
probability given by a smooth monotonic function $\Phi(V)$ of the membrane
potential $V$, rather than a sharp firing threshold. We find that such networks
can operate in several dynamic regimes (phases) depending on the average
synaptic weight and the shape of the firing function $\Phi$. In particular, we
encounter both continuous and discontinuous phase transitions to absorbing
states. At the continuous transition critical boundary, neuronal avalanches
occur whose distributions of size and duration are given by power laws, as
observed in biological neural networks. We also propose and test a new
mechanism to produce SOC: the use of dynamic neuronal gains -- a form of
short-term plasticity probably in the axon initial segment (AIS) -- instead of
depressing synapses at the dendrites (as previously studied in the literature).
The new self-organization mechanism produces a slightly supercritical state,
that we called SOSC, in accord to some intuitions of Alan Turing.


title: Mean Curvature Flows of Graphs with Neumann Boundary condition

abstract:
  In this paper, we study the mean curvature flow of graphs with Neumann
boundary condition. The main aim is to use the maximum principle to get the
boundary gradient estimate for solutions. In particular, we obtain the
corresponding existence theorem for the mean curvature flow of graphs.


title:
A Generalized Uhlenbeck and Beth Formula for the Third Cluster
  Coefficient

abstract:
  Relatively recently (A. Amaya-Tapia, S. Y. Larsen and M. Lassaut. Ann. Phys.,
vol. 306 (2011) 406), we presented a formula for the evaluation of the third
Bose fugacity coefficient - leading to the third virial coefficient - in terms
of three-body eigenphase shifts, for particles subject to repulsive forces. An
analytical calculation for a 1-dim. model, for which the result is known,
confirmed the validity of this approach. We now extend the formalism to
particles with attractive forces, and therefore must allow for the possibility
that the particles have bound states. We thus obtain a true generalization of
the famous formula of Uhlenbeck and Beth (G.E. Uhlenbeck and E. Beth. Physica,
vol. 3 (1936) 729; E. Beth and G.E. Uhlenbeck. ibid, vol.4 (1937) 915) (and of
Gropper (L. Gropper. Phys. Rev. vol. 50 (1936) 963; ibid vol. 51 (1937) 1108))
for the second virial. We illustrate our formalism by a calculation, in an
adiabatic approximation, of the third cluster in one dimension, using McGuire's
model as in our previous paper, but with attractive forces. The inclusion of
three-body bound states is trivial; taking into account states having
asymptotically two particles bound, and one free, is not.


title:
Experimental and first-principles studies of magnetism and
  magnetoelectric effect in Co4Nb2O9 and Co4Ta2O9

abstract:
  We report results of joint experimental and theoretical studies on
magnetoelectric (ME) compounds Co4Nb2O9 and Co4Ta2O9. On the experimental side,
we present results of the magnetization and dielectric permittivity
measurements in the magnetic field. On the theoretical side, we construct the
low-energy Hubbard-type model for the magnetically active Co 3d bands in the
Wannier basis, using the input of first-principles electronic structure
calculations, solve this model in the mean-field Hartree-Fock approximation,
and evaluate the electric polarization in terms of the Berry phase theory. Both
experimental and theoretical results suggest that Co4Ta2O9 is magnetically
softer than Co4Nb2O9. Therefore, it is reasonable to expect that the
antiferromagnetic structure of Co4Ta2O9 can be easier deformed by the external
magnetic field, yielding larger polarization. This trend is indeed reproduced
by our theoretical calculations, but does not seem to be consistent with the
experimental behavior of the polarization and dielectric permittivity. Thus, we
suggest that there should be a hidden mechanism controlling the ME coupling in
these compounds, probably related to the magnetic striction or a spontaneous
change of the magnetic structure, which breaks the inversion symmetry.
Furthermore, we argue that unlike in other ME systems (e.g. Cr2O3), in Co4Nb2O9
and Co4Ta2O9 there are two crystallographic sublattices, which contribute to
the ME effect. These contributions are found to be of the opposite sign and
tend to compensate each other. The latter mechanism can be also used to control
and reverse the electric polarization in these compounds.


title: Online Stochastic Matching: New Algorithms and Bounds

abstract:
  Online matching has received significant attention over the last 15 years due
to its close connection to Internet advertising. As the seminal work of Karp,
Vazirani, and Vazirani has an optimal (1 - 1/e) competitive ratio in the
standard adversarial online model, much effort has gone into developing useful
online models that incorporate some stochasticity in the arrival process. One
such popular model is the "known I.I.D. model" where different customer-types
arrive online from a known distribution. We develop algorithms with improved
competitive ratios for some basic variants of this model with integral arrival
rates, including (a) the case of general weighted edges, where we improve the
best-known ratio of 0.667 due to Haeupler, Mirrokni and Zadimoghaddam to 0.705;
and (b) the vertex-weighted case, where we improve the 0.7250 ratio of Jaillet
and Lu to 0.7299. We also consider an extension of stochastic rewards, a
variant where each edge has an independent probability of being present. For
the setting of stochastic rewards with non-integral arrival rates, we present a
simple optimal non-adaptive algorithm with a ratio of 1 - 1/e. For the special
case where each edge is unweighted and has a uniform constant probability of
being present, we improve upon 1 - 1/e by proposing a strengthened LP
benchmark.


title: On optimal embeddings and trees

abstract:
  We apply the theory of Bruhat-Tits trees to the study of optimal embeddings
of two and three dimensional commutative orders into quaternion algebras.
Specifically, we determine how many conjugacy classes of global Eichler orders
in a quaternion algebra yield optimal representations of such orders. This
completes the previous work by C. Maclachlan, who considered only Eichler
orders of square free level and integral domains as sub-orders. The same
technique is used in the second part of this work to compute local embedding
numbers, extending previous results by J. Brzezinski.


title:
On the existence of the biharmonic Green kernels and the the adjoint
  biharmonic functions

abstract:
  We study the existence and the regularity of the biharmonic Green kernel in a
Brelot biharmonic space whose associated harmonic spaces have Green kernels. We
show by some examples that this kernel does not always exist. We then introduce
and study the adjoint of the given biharmonic space. This study was initiated
by Smyrnelis, however, it seems that several results were incomplete and we
clarify them here.


title: On the Hodge-Newton filtration for p-divisible groups of Hodge type

abstract:
  A p-divisible group, or more generally an F-crystal, is said to be
Hodge-Newton reducible if its Hodge polygon passes through a break point of its
Newton polygon. Katz proved that Hodge-Newton reducible F-crystals admit a
canonical filtration called the Hodge-Newton filtration. The notion of
Hodge-Newton reducibility plays an important role in the deformation theory of
p-divisible groups; the key property is that the Hodge-Newton filtration of a
p-divisible group over a field of characteristic p can be uniquely lifted to a
filtration of its deformation.
  We generalize Katz's result to F-crystals that arise from an unramified local
Shimura datum of Hodge type. As an application, we give a generalization of
Serre-Tate deformation theory for local Shimura data of Hodge type. We also
apply our deformation theory to study some congruence relations on Shimura
varieties of Hodge type.


title:
Uniqueness Trees: A Possible Polynomial Approach to the Graph
  Isomorphism Problem

abstract:
  This paper presents the novel `uniqueness tree' algorithm, as one possible
method for determining whether two finite, undirected graphs are isomorphic. We
prove that the algorithm has polynomial time complexity in the worst case, and
that it will always detect the presence of an isomorphism whenever one exists.
We also propose that the algorithm will equivalently discern the lack of an
isomorphism whenever one does not exist, and some initial justifications are
given for this proposition, although it cannot yet be rigorously proven.
Finally, we present experimental evidence for both the effectiveness and
efficiency of the uniqueness tree method, using data gathered from a practical
implementation of the algorithm. Some consequences and directions for further
research are discussed.


title: Paramagnetic excited vortex states in superconductors

abstract:
  We consider excited vortex states, which are vortex states left inside a
superconductor once the external applied magnetic field is switched off and
whose energy is lower than of the normal state. We show that this state is
paramagnetic and develop here a general method to obtain its Gibbs free energy
through conformal mapping. The solution for any number of vortices in any cross
section geometry can be read off from the Schwarz - Christoffel mapping. The
method is based on the first order equations used by A. Abrikosov to discover
vortices.


title: A mesoscopic model for binary fluids

abstract:
  We propose a model to study symmetric binary fluids, based in the mesoscopic
molecular simulation technique known as multiparticle collision, where space
and state variables are continuous while time is discrete. We include a
repulsion rule to simulate segregation processes that does not require the
calculation of the interaction forces between particles, thus allowing the
description of binary fluids at a mesoscopic scale. The model is conceptually
simple, computationally efficient, maintains Galilean invariance, and conserves
the mass and the energy in the system at micro and macro scales; while momentum
is conserved globally. For a wide range of temperatures and densities, the
model yields results in good agreement with the known properties of binary
fluids, such as density profile, width of the interface, phase separation and
phase growth. We also apply the model to study binary fluids in crowded
environments with consistent results.


title:
Relationship between Symmetry Protected Topological Phases and Boundary
  Conformal Field Theories via the Entanglement Spectrum

abstract:
  Quantum phase transitions out of a symmetry-protected topological (SPT) phase
in (1+1) dimensions into an adjacent, topologically distinct SPT phase
protected by the same symmetry or a trivial gapped phase, are typically
described by a conformal field theory (CFT). At the same time, the low-lying
entanglement spectrum of a gapped phase close to such a quantum critical point
is known(Cho et al., arXiv:1603.04016), very generally, to be universal and
described by (gapless) boundary conformal field theory. Using this connection
we show that symmetry properties of the boundary conditions in boundary CFT can
be used to characterize the symmetry-protected degeneracies of the entanglement
spectrum, a hallmark of non-trivial symmetry-protected topological phases.
Specifically, we show that the relevant boundary CFT is the orbifold of the
quantum critical point with respect to the symmetry group defining the SPT, and
that the boundary states of this orbifold carry a quantum anomaly that
determines the topological class of the SPT. We illustrate this connection
using various characteristic examples such as the time-reversal breaking
"Kitaev chain" superconductor (symmetry class D), the Haldane phase, and the
$\mathbb{Z}_8$ classification of interacting topological superconductors in
symmetry class BDI in (1+1) dimensions.


title:
Cooperative single-photon subradiant states in a three-dimensional
  atomic array

abstract:
  We propose a complete superradiant and subradiant states that can be
manipulated and prepared in a three-dimensional atomic array. These subradiant
states can be realized by absorbing a single photon and imprinting the
spatially-dependent phases on the atomic system. We find that the collective
decay rates and associated cooperative Lamb shifts are highly dependent on the
phases we manage to imprint, and the subradiant state of long lifetime can be
found for various lattice spacings and atom numbers. We also investigate both
optically thin and thick atomic arrays, which can serve for systematic studies
of super- and sub-radiance. Our proposal offers an alternative scheme for
quantum memory of light in a three-dimensional array of two-level atoms, which
is applicable and potentially advantageous in quantum information processing.


title: Concordance group of virtual knots

abstract:
  We study concordance of virtual knots. Our main result is that a classical
knot K is virtually slice if and only if it is classically slice. From this we
deduce that the concordance group of classical knots embeds into the
concordance group of long virtual knots.


title:
The role of the spin connection in quantum Hall effect: A perspective
  from geometric quantization

abstract:
  The topological terms of the bulk effective action for the integer quantum
Hall effect, capturing the dynamics of gauge and gravitational fluctuations,
reveal a curiosity, namely, the Abelian potential for the magnetic field
appears in a particular combination with the Abelian spin connection. This
seems to hold for quantum Hall effect on complex projective spaces of arbitrary
dimensions. An interpretation of this in terms of the algebra of symplectic
transformations is given. This can also be viewed in terms of the metaplectic
correction in geometric quantization.

categories: hep-th cond-mat.mes-hall math-ph math.MP


title: Incremental Parsing with Minimal Features Using Bi-Directional LSTM

abstract:
  Recently, neural network approaches for parsing have largely automated the
combination of individual features, but still rely on (often a larger number
of) atomic features created from human linguistic intuition, and potentially
omitting important global context. To further reduce feature engineering to the
bare minimum, we use bi-directional LSTM sentence representations to model a
parser state with only three sentence positions, which automatically identifies
important aspects of the entire sentence. This model achieves state-of-the-art
results among greedy dependency parsers for English. We also introduce a novel
transition system for constituency parsing which does not require binarization,
and together with the above architecture, achieves state-of-the-art results
among greedy parsers for both English and Chinese.


title: Elements of Geometric Quantization and Applications to Fields and Fluids

abstract:
  These lecture notes (from the Second Autumn School in High Energy Physics and
Quantum Field Theory, Yerevan 2014) cover a number of topics related to
geometric quantization. Most of the material is presented from a physicist's
point of view. The original notes are posted at
\verb+http://theorphyslab-ysu.info/VW_ASW-2014/uploads/ArmeniaLectures.pdf+.
The have been revised with some additions and changes, although referencing is
still somewhat dated. These notes are posted here as they may be good
background material for some recent papers.

categories: hep-th cond-mat.mes-hall math-ph math.MP quant-ph


title:
Convergence Analysis and Assurance for Gaussian Message Passing
  Iterative Detector in Massive MU-MIMO Systems

abstract:
  This paper considers a low-complexity Gaussian Message Passing Iterative
Detection (GMPID) algorithm for massive Multiuser Multiple-Input
Multiple-Output (MU-MIMO) system, in which a base station with $M$ antennas
serves $K$ Gaussian sources simultaneously. Both $K$ and $M$ are very large
numbers, and we consider the cases that $K<M$. The GMPID is a low-complexity
message passing algorithm based on a fully connected loopy graph, which is well
understood to be not convergent in some cases. As it is hard to analyse the
GMPID directly, the large-scale property of the massive MU-MIMO is used to
simplify the analysis. Firstly, we prove that the variances of the GMPID
definitely converge to the mean square error of Minimum Mean Square Error
(MMSE) detection. Secondly, we propose two sufficient conditions that the means
of the GMPID converge to those of the MMSE detection. However, the means of
GMPID may not converge when $ K/M\geq (\sqrt{2}-1)^2$. Therefore, a new
convergent GMPID called SA-GMPID (scale-and-add GMPID) , which converges to the
MMSE detection in mean and variance for any $K<M$ and has a faster convergence
speed than the GMPID, but has no higher complexity than the GMPID, is proposed.
Finally, numerical results are provided to verify the validity and accuracy of
the theoretical results.


title:
Stochastic homogenization of viscous superquadratic Hamilton-Jacobi
  equations in dynamic random environment

abstract:
  We study the qualitative homogenization of second order viscous
Hamilton-Jacobi equations in space-time stationary ergodic random environments.
Assuming that the Hamiltonian is convex and superquadratic in the momentum
variable (gradient) we establish a homogenization result and characterize the
effective Hamiltonian for arbitrary (possibly degenerate) elliptic diffusion
matrices. The result extends previous work that required uniform ellipticity
and space-time homogeneity for the diffusion.


title:
Thermodynamic measurement of the sound velocity of a Bose gas across the
  transition to Bose-Einstein condensation

abstract:
  We present an alternative method for determining the sound velocity in atomic
Bose-Einstein condensates, based on thermodynamic global variables. The total
number of trapped atoms was as a function of temperature carefully studied
across the phase transition, at constant volume. It allowed us to evaluate the
sound velocity resulting in consistent values from the quantum to classical
regime, in good agreement with previous results found in literature. We also
provide some insight about the dominant sound mode (thermal or superfluid)
across a wide temperature range.


title:
Exact sampling of first passage event of certain symmetric Levy
  processes with unbounded variation

abstract:
  We show that exact sampling of the first passage event can be done for a Levy
process with unbounded variation, if the process can be embedded in a
subordinated standard Brownian motion. By sampling a series of first exit
events of the Brownian motion and first passage events of the subordinator, the
first passage event of interest can be obtained. The sampling of the first exit
time and pre-exit location of the Brownian motion may be of independent
interest.


title: Sparse graphs of high gonality

abstract:
  By considering graphs as discrete analogues of Riemann surfaces, Baker and
Norine (Adv. Math. 2007) developed a concept of linear systems of divisors for
graphs. Building on this idea, a concept of gonality for graphs has been
defined and has generated much recent interest. We show that there are
connected graphs of treewidth 2 of arbitrarily high gonality. We also show that
there exist pairs of connected graphs $\{G,H\}$ such that $H\subseteq G$ and
$H$ has strictly lower gonality than $G$. These results resolve three open
problems posed in a recent survey by Norine (Surveys in Combinatorics 2015).


title:
Stability of positive solutions to biharmonic equations on Heisenberg
  group

abstract:
  In this note, we establish the existence of a positive solution and its
stability to the following problem
$$\Delta_{\mathbb{H}^n}^2u=a(\xi)u-f(\xi,u)\text{ in }\Omega, \,\,\,
u|_{\partial\Omega} = 0 =\left.\Delta_{\mathbb{H}^n} u|_{\partial\Omega},$$ on
Heisenberg group.


title:
Singular Adams inequality for biharmonic operator on Heisenberg Group
  and its applications

abstract:
  The goal of this paper is to establish singular Adams type inequality for
biharmonic operator on Heisenberg group. As an application, we establish the
existence of a solution to \begin{equation*} \Delta_{\mathbb{H}^n}^2
u=\frac{f(\xi,u)}{\rho(\xi)^a}\,\,\text{ in }\Omega,\,\,
u|_{\partial\Omega}=0=\left.\frac{\partial u}{\partial
\nu}\right|_{\partial\Omega}, \end{equation*} where $0\in \Omega \subseteq
\mathbb{H}^4$ is a smooth bounded domain, $0\leq a<Q,\,(Q=10).$ The special
feature of this problem is that it contains an exponential nonlinearity and
singular potential.


title: Evolutionary status of isolated B[e] stars

abstract:
  Aims. We study a sample of eight B[e] stars with uncertain evolutionary
status to shed light on the origin of their circumstellar dust.
  Methods. We performed a diagnostic analysis on the spectral energy
distribution beyond infrared wavelengths, and conducted a census of neighboring
region of each target to ascertain its evolutionary status.
  Results. In comparison to pre-main sequence Herbig stars, these B[e] stars
show equally substantial excess emission in the near-infrared, indicative of
existence of warm dust, but much reduced excess at longer wavelengths, so the
dusty envelopes should be compact in size. Isolation from star-forming regions
excludes the possibility of their pre-main sequence status. Six of our targets,
including HD 50138, HD 45677, CD-245721, CD-49 3441, MWC 623, and HD 85567,
have been previously considered as FS CMa stars, whereas HD 181615/6 and HD
98922 are added to the sample by this work. We argue that the circumstellar
grains of these isolated B[e] stars, already evolved beyond the pre-main
sequence phase, should be formed in situ. This is in contrast to Herbig stars,
which inherit large grains from parental molecular clouds. It has been thought
that HD 98922, in particular, is a Herbig star because of its large infrared
excess, but we propose it being in a more evolved stage. Because dust condenses
out of stellar mass loss in an inside-out manner, the dusty envelope is
spatially confined, and anisotropic mass flows, or anomalous optical properties
of tiny grains, lead to the generally low line-of-sight extinction toward these
stars.


title:
Non-equilibrium fractional quantum Hall states visualized by optically
  detected MRI

abstract:
  Using photoluminescence microscopy enhanced by MRI, we visualize in real
space both electron and nuclear polarization occurring in non-equilibrium FQH
liquids. We observe stripe-like regions comprising FQH excited states which
discretely form when the FQH liquid is excited by a source-drain current. These
regions are topologically protected and deformable, and give rise to
bidirectionally polarized nuclear spins as spin-resolved electrons flow across
their boundaries.


title:
Reconstruction theorems for semigroups of functions which contain all
  transpositions of a set and for clones with the same property

abstract:
  We prove that if S is a set of functions from a set A to itself, S is closed
under composition, and S contains all transpositions of A, then the action of S
on Acan be recovered from the semigroup consisting of S together with its
compositionoperation. We also prove the analogous statement for clones.


title: Finite State Markov Wiretap Channel with Delayed Feedback

abstract:
  The finite state Markov channel (FSMC), where the channel transition
probability is controlled by a state undergoing a Markov process, is a useful
model for the mobile wireless communication channel. In this paper, we
investigate the security issue in the mobile wireless communication systems by
considering the FSMC with an eavesdropper, which we call the finite state
Markov wiretap channel (FSM-WC). We assume that the state is perfectly known by
the legitimate receiver and the eavesdropper, and through a noiseless feedback
channel, the legitimate receiver sends his received channel output and the
state back to the transmitter after some time delay. Inner and outer bounds on
the capacity-equivocation regions of the FSM-WC with delayed state feedback and
with or without delayed channel output feedback are provided in this paper, and
we show that these bounds meet if the eavesdropper's received symbol is a
degraded version of the legitimate receiver's. The above results are further
explained via degraded Gaussian and Gaussian fading examples.


title:
Qubit assisted enhancement of quantum correlations in an optomechanical
  system

abstract:
  We perform a theoretical study on quantum correlations in an optomechanical
system where the mechanical mirror is perturbatively coupled to an auxiliary
qubit. In our study, we consider logarithmic negativity to quantify the degree
of stationary entanglement between the cavity field and mechanical mirror, and,
Gaussian quantum discord as an witness of the quantumness of the correlation
beyond entanglement. Utilizing experimentally feasible parameters, we show that
both entanglement and quantum discord enhance significantly with increase in
mirror-qubit coupling. Moreover, we find that in presence of the mirror-qubit
coupling entanglement could be generated at a considerably lower optomechanical
coupling strength, which is also extremely robust against the environmental
temperature. Overall, our proposed scheme offers some considerable advantages
for realizing the continuous-variable quantum information and communication.


title: Colored-hadron distribution in hadron scattering in SU(2) lattice QCD

abstract:
  In color SU(2) lattice QCD, we investigate colored-diquark distributions in
two-hadron scatterings by means of Bethe-Salpeter amplitudes on the lattice.
With colored-diquark operators in the Coulomb gauge, we measure components of
two colored diquarks realized as intermediate states via one gluon exchange
(OGE) processes in hadron scattering. From the colored-diquark distributions,
we estimate the dominant range of gluon (color) exchanges between closely
located two hadrons. We find that the colored-diquark components are enhanced
at the short range ($\leq$0.2 fm) and their tails show the single-exponential
damping. In order to distinguish the genuine colored-diquark components
originating in the color exchange processes from trivial colored two-quark
components contained in two color-singlet hadrons as a result of simple
transformation of hadronic basis, we repeat the analyses on the artificially
constructed gauge fields, where low- and high-momentum gluon components are
decoupled and only restricted pair of quarks can share and exchange
low-momentum gluons. We observe qualitatively the same behaviors and confirm
that the short-range enhancement of the colored-diquark distributions is the
genuine OGE-origin color excitation in hadron scattering.


title:
Approximation of the weighted maximin dispersion problem over Lp-ball:
  SDP relaxation is misleading

abstract:
  Consider the problem of finding a point in a unit $n$-dimensional
$\ell_p$-ball ($p\ge 2$) such that the minimum of the weighted Euclidean
distance from given $m$ points is maximized. We show in this paper that the
recent SDP-relaxation-based approximation algorithm [SIAM J. Optim. 23(4),
2264-2294, 2013] will not only provide the first theoretical approximation
bound of $\frac{1-O\left(\sqrt{ \ln(m)/n}\right)}{2}$, but also perform much
better in practice, if the SDP relaxation is removed and the optimal solution
of the SDP relaxation is replaced by a simple scalar matrix.


title: Weakly True Concurrency and Its Logic

abstract:
  We firstly find the existence of silent event $\tau$ in true concurrency
(named weakly true concurrency) by defining weakly true concurrent behaviors
and weakly true concurrent logics. Based on Paolo Baldan and Silvia Crafa's
comprehensive work on (strongly) true concurrency, we find the correspondence
between weakly true concurrent equivalences and weakly true concurrent logics.


title: Non-Coherent Direction of Arrival Estimation via Frequency Estimation

abstract:
  This letter investigates the non-coherent Direction of Arrival (DOA)
estimation problem dealing with the DOA estimation from magnitude only
measurements of the array output. The magnitude squared of the array output is
expanded as a superposition of some harmonics. Hence, a frequency estimation
approach is used to find some nonlinear relations between DOAs, which results
in inherent ambiguities. To solve the nonlinear equations and resolve the
ambiguities, we assume a high amplitude reference target at low angles to
estimate the true DOA's with no ambiguities. However, the proposed algorithm
requires a large number of antenna array elements to accurately estimate the
DOA's. To overcome this drawback, and to enhance the estimation accuracy, we
suggest two variants of the algorithm. One is to add virtual elements in the
array and the second is to integrate multiple snapshots. Simulation results
show that the proposed frequency estimation-based algorithm outperforms the
non-coherent GESPAR algorithm in the low signal to noise ratio (SNR) regime and
it is two orders of magnitude faster than the non-coherent GESPAR algorithm.


title:
A Novel Framework to Expedite Systematic Reviews by Automatically
  Building Information Extraction Training Corpora

abstract:
  A systematic review identifies and collates various clinical studies and
compares data elements and results in order to provide an evidence based answer
for a particular clinical question. The process is manual and involves lot of
time. A tool to automate this process is lacking. The aim of this work is to
develop a framework using natural language processing and machine learning to
build information extraction algorithms to identify data elements in a new
primary publication, without having to go through the expensive task of manual
annotation to build gold standards for each data element type. The system is
developed in two stages. Initially, it uses information contained in existing
systematic reviews to identify the sentences from the PDF files of the included
references that contain specific data elements of interest using a modified
Jaccard similarity measure. These sentences have been treated as labeled data.A
Support Vector Machine (SVM) classifier is trained on this labeled data to
extract data elements of interests from a new article. We conducted experiments
on Cochrane Database systematic reviews related to congestive heart failure
using inclusion criteria as an example data element. The empirical results show
that the proposed system automatically identifies sentences containing the data
element of interest with a high recall (93.75%) and reasonable precision
(27.05% - which means the reviewers have to read only 3.7 sentences on
average). The empirical results suggest that the tool is retrieving valuable
information from the reference articles, even when it is time-consuming to
identify them manually. Thus we hope that the tool will be useful for automatic
data extraction from biomedical research publications. The future scope of this
work is to generalize this information framework for all types of systematic
reviews.


title:
Study of open clusters within 1.8 kpc and understanding the Galactic
  structure

abstract:
  Based on an almost complete sample of Galactic open star clusters within 1.8
kpc, we perform a comprehensive statistical analysis of various cluster
parameters like spatial position, age, size, mass and extinction in order to
understand the general properties of the open cluster system in the Galaxy and
the Galactic structure. Based on the distribution of 1241 open clusters about
the Galactic plane and in different age bins, we find the average Galactic
scale height as Zh = 60+/-2 pc for the youngest cluster population having Age
<700 Myr, however, it increases up to 64+/-2 pc when we also include older
population of clusters. The solar offset is found to be 6.2+/-1.1 pc above the
formal Galactic plane. We derive a local mass density of \rho_0 = 0.090+/-0.005
Msun/pc^3 and found a negligibly small amount of dark matter in the solar
neighbourhood. The reddening in the direction of clusters suggests a strong
correlation with their vertical distance from the Galactic plane having a
respective slope of dE(B-V)/dz = 0.40+/-0.04 and 0.42+/-0.05 mag/kpc below and
above the GP. We observe a linear mass-radius and mass-age relations in the
open clusters and derive a slope of dR/d(logM) = 2.08+/-0.10 and
d(logM)/d(logT) = -0.36+/-0.05,respectively.


title: The hot Gamma-Doradus and Maia stars

abstract:
  The hot $\gamma$~Doradus stars have multiple low frequencies characteristic
of $\gamma$~Dor or SPB variables, but are located between the red edge of the
SPB and the blue edge of the $\gamma$~Dor instability strips where all
low-frequency modes are stable in current models of these stars. Though
$\delta$~Sct stars also have low frequencies, there is no sign of high
frequencies in hot $\gamma$~Dor stars. We obtained spectra to refine the
locations of some of these stars in the H-R diagram and conclude that these
are, indeed, anomalous pulsating stars. The Maia variables have multiple high
frequencies characteristic of $\beta$~Cep and $\delta$~Sct stars, but lie
between the red edge of the $\beta$~Cep and the blue edge of the $\delta$~Sct
instability strips. We compile a list of all Maia candidates and obtain spectra
of two of these stars. Again, it seems likely that these are anomalous
pulsating stars which are currently not understood.


title: Clustering with Capacity and Size Constraints: A Deterministic Approach

abstract:
  This paper discusses a deterministic clustering approach to capacitated
resource allocation problems. In particular, the Deterministic Annealing (DA)
algorithm from the data-compression literature, which bears a distinct analogy
to the phase transformation under annealing process in statistical physics, is
adapted to address problems pertaining to clustering with several forms of size
constraints. These constraints are addressed through appropriate modifications
of the basic DA formulation by judiciously adjusting the free-energy function
in the DA algorithm. At a given value of the annealing parameter, the
iterations of the DA algorithm are of the form of a Descent Method, which
motivate scaling principles for faster convergence.


title:
All $\alpha+u\beta$-constacyclic codes of length $np^{s}$ over
  $\mathbb{F}_{p^{m}}+u\mathbb{F}_{p^{m}}$

abstract:
  Let $\mathbb{F}_{p^{m}}$ be a finite field with cardinality $p^{m}$ and
$R=\mathbb{F}_{p^{m}}+u\mathbb{F}_{p^{m}}$ with $u^{2}=0$. We aim to determine
all $\alpha+u\beta$-constacyclic codes of length $np^{s}$ over $R$, where
$\alpha,\beta\in\mathbb{F}_{p^{m}}^{*}$, $n, s\in\mathbb{N}_{+}$ and
$\gcd(n,p)=1$. Let $\alpha_{0}\in\mathbb{F}_{p^{m}}^{*}$ and
$\alpha_{0}^{p^{s}}=\alpha$. The residue ring $R[x]/\langle
x^{np^{s}}-\alpha-u\beta\rangle$ is a chain ring with the maximal ideal
$\langle x^{n}-\alpha_{0}\rangle$ in the case that $x^{n}-\alpha_{0}$ is
irreducible in $\mathbb{F}_{p^{m}}[x]$. If $x^{n}-\alpha_{0}$ is reducible in
$\mathbb{F}_{p^{m}}[x]$, we give the explicit expressions of the ideals of
$R[x]/\langle x^{np^{s}}-\alpha-u\beta\rangle$. Besides, the number of
codewords and the dual code of every $\alpha+u\beta$-constacyclic code are
provided.


title:
The Gap of the Consecutive Eigenvalues of the Drifting Laplacian on
  Metric Measure Spaces

abstract:
  In this paper, we investigate eigenvalues of the Dirichlet problem and the
closed eigenvalue problem of drifting Laplacian on the complete metric measure
spaces and establish the corresponding general formulas. By using those general
formulas, we give some upper bounds of consecutive gap of the eigenvalues of
the eigenvalue problems, which is sharp in the sense of the order of the
eigenvalues. As some interesting applications, we study the eigenvalue of
drifting Laplacian on Ricci solitons, self-shrinkers and product Riemannian
manifolds. We give the explicit upper bounds of the gap of the consecutive
eigenvalues of the drifting Laplacian. Since eigenvalues is invariant in the
sense of isometry, by the classifications of Ricci solitons and self-shrinkers,
we give the explicit upper bounds for the consecutive eigenvalues of the
drifting Laplacian on a large class metric measure spaces. In addition, we also
consider the case of product Riemannian manifolds with certain curvature
conditions and some upper bounds are obtained. Basing on the case of Laplace
operator, we also present a conjecture as follows: all of the eigenvalues of
the Dirichlet problem of drifting Laplacian on metric measure spaces satisfy:
$$\lambda_{k+1}-\lambda_{k}\leq(\lambda_{2}-\lambda_{1})k^{\frac{1}{n}}.$$We
note the conjecture is true in some special cases.


title:
New halo stars of the Galactic globular clusters M3 and M13 in the
  LAMOST DR1 Catalog

abstract:
  M3 and M13 are Galactic globular clusters with previous reports of
surrounding stellar halos. We present the results of a search for members and
extratidal cluster halo stars within and outside of the tidal radius of these
clusters in the LAMOST Data Release 1. We find seven candidate cluster members
(inside the tidal radius) of both M3 and M13 respectively. In M3 we also
identify eight candidate extratidal cluster halo stars at distances up to ~9.8
times the tidal radius, and in M13 we identify 12 candidate extratidal cluster
halo stars at distances up to ~13.8 times the tidal radius. These results
support previous indications that both M3 and M13 are surrounded by extended
stellar halos, and we find that the GC destruction rates corresponding to the
observed mass loss are generally significantly higher than theoretical studies
predict.


title:
Optical and Radio variability of the Northern VHE gamma-ray emitting BL
  Lac objects

abstract:
  We compare the variability properties of very high energy gamma-ray emitting
BL Lac objects in the optical and radio bands. We use the variability
information to distinguish multiple emission components in the jet, to be used
as a guidance for spectral energy distribution modelling. Our sample includes
32 objects in the Northern sky that have data for at least 2 years in both
bands. We use optical R-band data from the Tuorla blazar monitoring program and
15 GHz radio data from the Owens Valley Radio Observatory blazer monitoring
program. We estimate the variability amplitudes using the intrinsic modulation
index, and study the time-domain connection by cross-correlating the optical
and radio light curves assuming power law power spectral density. Our sample
objects are in general more variable in the optical than radio. We find
correlated flares in about half of the objects, and correlated long-term trends
in more than 40% of the objects. In these objects we estimate that at least
10%-50% of the optical emission originates in the same emission region as the
radio, while the other half is due to faster variations not seen in the radio.
This implies that simple single-zone spectral energy distribution models are
not adequate for many of these objects.


title:
Nanoparticle Translocation through Conical Nanopores: A Finite Element
  Study of Electrokinetic Transport

abstract:
  Recent years have seen a surge of interest in nanopores because such
structures show a strong potential for characterizing nanoparticles, proteins,
DNA, and even single molecules. These systems have been extensively studied in
experiment as well as by all-atom and coarse-grained simulations, with a strong
focus on DNA translocation. However, the equally interesting problem of
particle characterization using nanopores has received far less attention.
Here, we theoretically investigate the translocation of a nanoparticle through
a conical nanocapillary. We use a model based on numerically solving the
coupled system of electrokinetic continuum equations, which we introduce in
detail. Based on our findings, we formulate basic guidelines for obtaining the
maximum current signal during the translocation event, which should be
transferable to other nanopore geometries. In addition, the dependence of the
signal strength on particle properties, such as surface charge and size, is
evaluated. Finally, we identify conditions under which the translocation is
prevented by the formation of a strong electro-osmotic barrier and show that
the particle may even become trapped at the pore orifice, without imposing an
external hydrostatic pressure difference.


title: Mechanism of High-Order Harmonic Generation from Periodic Potentials

abstract:
  We study numerically the Bloch electron wave-packet dynamics in periodic
potentials to simulate laser-solid interactions. We introduce a quasi-classical
model in the \emph{k} space combined with the energy band structure to
understand the high-order harmonic generation (HHG) process occurring in a
subcycle timescale. This model interprets the multiple plateau structure in HHG
spectra well and the linear dependence of cutoff energies on the amplitude of
vector potential of the laser fields. It also predicts the emission time of
HHG, which agrees well with the results by solving the time-dependent
Schr\"{o}dinger equation (TDSE). It provides a scheme to reconstruct the energy
dispersion relations in Brillouin zone and to control the trajectories of HHG
by varying the shape of laser pulses. This model is instructive for
experimental measurements.


title: The Schema Editor of OpenIoT for Semantic Sensor Networks

abstract:
  Ontologies provide conceptual abstractions over data, in domains such as the
Internet of Things, in a way that sensor data can be harvested and interpreted
by people and applications. The Semantic Sensor Network (SSN) ontology is the
de-facto standard for semantic representation of sensor observations and
metadata, and it is used at the core of the open source platform for the
Internet of Things, OpenIoT. In this paper we present a Schema Editor that
provides an intuitive web interface for defining new types of sensors, and
concrete instances of them, using the SSN ontology as the core model. This
editor is fully integrated with the OpenIoT platform for generating virtual
sensor descriptions and automating their semantic annotation and registration
process.


title:
Adsorption and STM imaging of tetracyanoethylene on Ag(001): An
  ab-initio study

abstract:
  We investigate the adsorption of a single tetracyanoethylene (TCNE) molecule
on the silver (001) surface. Adsorption structures, electronic properties, and
scanning tunneling microscopy (STM) images are calculated within
density-functional theory. Adsorption occurs most favorably in on-top
configuration, with the C=C double bond directly above a silver atom and the
four N atoms bound to four neighboring Ag atoms. The lowest unoccupied
molecular orbital of TCNE becomes occupied due to electron transfer from the
substrate. This state dominates the electronic spectrum and the STM image at
moderately negative bias. We discuss and employ a spatial extrapolation
technique for the calculation of STM and scanning tunneling spectroscopy (STS)
images. Our calculated images are in good agreement with experimental data.


title:
On the derivation of the Hartree equation in the mean field limit:
  Uniformity in the Planck constant

abstract:
  In this paper the Hartree equation is derived from the $N$-body
Schr\''odinger equation in the mean-field limit, with convergence rate
estimates that are uniform in the Planck constant $\hbar$. Specifically, we
consider the two following cases:(a) T\''oplitz initial data and Lipschitz
interaction forces, and (b) analytic initial data and interaction potential,
over short time intervals independent of $\hbar$. The convergence rates in
these two cases are $1/\sqrt{\log\log N}$ and $1/N$ respectively. The treatment
of the second case is entirely self-contained and all the constants appearing
in the final estimate are explicit. It provides a derivation of the Vlasov
equation from the $N$-body classical dynamics using BBGKY hierarchies instead
of empirical measures.


title: Efficient 2D and 3D Facade Segmentation using Auto-Context

abstract:
  This paper introduces a fast and efficient segmentation technique for 2D
images and 3D point clouds of building facades. Facades of buildings are highly
structured and consequently most methods that have been proposed for this
problem aim to make use of this strong prior information. Contrary to most
prior work, we are describing a system that is almost domain independent and
consists of standard segmentation methods. We train a sequence of boosted
decision trees using auto-context features. This is learned using stacked
generalization. We find that this technique performs better, or comparable with
all previous published methods and present empirical results on all available
2D and 3D facade benchmark datasets. The proposed method is simple to
implement, easy to extend, and very efficient at test-time inference.


title:
Equivalence of finite dimensional input-output models of solute
  transport and diffusion in geosciences

abstract:
  We show that for a large class of finite dimensional input-output positive
systems that represent networks of transport and diffusion of solute in
geological media, there exist equivalent multi-rate mass transfer and multiple
interacting continua representations, which are quite popular in geo-sciences.
Moreover, we provide explicit methods to construct these equivalent
representations. The proofs show that controllability property is playing a
crucial role for obtaining equivalence. These results contribute to our
fundamental understanding on the effect of fine-scale geological structures on
the transfer and dispersion of solute, and, eventually, on their interaction
with soil microbes and minerals.


title: Social-sparsity brain decoders: faster spatial sparsity

abstract:
  Spatially-sparse predictors are good models for brain decoding: they give
accurate predictions and their weight maps are interpretable as they focus on a
small number of regions. However, the state of the art, based on total
variation or graph-net, is computationally costly. Here we introduce sparsity
in the local neighborhood of each voxel with social-sparsity, a structured
shrinkage operator. We find that, on brain imaging classification problems,
social-sparsity performs almost as well as total-variation models and better
than graph-net, for a fraction of the computational cost. It also very clearly
outlines predictive regions. We give details of the model and the algorithm.


title: On three-dimensional plasmon resonance in elastostatics

abstract:
  We consider the plasmon resonance for the elastostatic system in
$\mathbb{R}^3$ associated with a very broad class of sources. The plasmonic
device takes a general core-shell-matrix form with the metamaterial located in
the shell. It is shown that the plasmonic device in the literature which
induces resonance in $\mathbb{R}^2$ does not induce resonance in
$\mathbb{R}^3$. We then construct two novel plasmonic devices with suitable
plasmon constants, varying according to the source term or the loss parameter,
which can induce resonances. If there is no core, we show that resonance always
occurs. If there is a core of an arbitrary shape, we show that the resonance
strongly depends on the location of the source. In fact, there exists a
critical radius such that resonance occurs for sources lying within the
critical radius, whereas resonance does not occur for source lying outside the
critical radius. Our argument is based on the variational technique by making
use of the primal and dual variational principles for the elastostatic system,
along with the highly technical construction of the associated perfect plasmon
elastic waves.


title:
Nucleon structure functions and longitudinal spin asymmetries in the
  chiral quark constituent model

abstract:
  We have analysed the phenomenological dependence of the spin independent
($F_1^{p,n}$ and $F_2^{p,n}$) and the spin dependent ($g_1^{p,n}$) structure
functions of the nucleon on the the Bjorken scaling variable $x$ using the
unpolarized distribution functions of the quarks $q(x)$ and the polarized
distribution functions of the quarks $\Delta q(x)$ respectively. The chiral
constituent quark model ($\chi$CQM), which is known to provide a satisfactory
explanation of the proton spin crisis and related issues in the nonperturbative
regime, has been used to compute explicitly the valence and sea quark flavor
distribution functions of $p$ and $n$. In light of the improved precision of
the world data, the $p$ and $n$ longitudinal spin asymmetries ($A_1^p(x)$ and
$A_1^n(x)$) have been calculated. The implication of the presence of the sea
quarks has been discussed for ratio of polarized to unpolarized quark
distribution functions for up and down quarks in the $p$ and $n$ $\frac{\Delta
u^p(x)}{u^p(x)}$, $\frac{\Delta d^p(x)}{d^p(x)}$, $\frac{\Delta
u^n(x)}{u^n(x)}$, and $\frac{\Delta d^n(x)}{d^n(x)}$. The ratio of the $n$ and
$p$ structure functions $R^{np}(x)=\frac{F_2^n(x)}{F_2^p(x)}$ has also been
presented. The results have been compared with the recent available
experimental observations. The results on the spin sum rule have also been
included and compared with data and other recent approaches.


title: Conjugation Properties of Tensor Product and Fusion Coefficients

abstract:
  We review some recent results on properties of tensor product and fusion
coefficients under complex conjugation of one of the factors. Some of these
results have been proven, some others are conjectures awaiting a proof, one of
them involving hitherto unnoticed observations on ordinary representation
theory of finite simple groups of Lie type