title: Consistent Manifold Representation for Topological Data Analysis

abstract:
  For data sampled from an arbitrary density on a manifold embedded in
Euclidean space, the Continuous k-Nearest Neighbors (CkNN) graph construction
is introduced. It is shown that CkNN is geometrically consistent in the sense
that under certain conditions, the unnormalized graph Laplacian converges to
the Laplace-Beltrami operator, spectrally as well as pointwise. It is proved
for compact (and conjectured for noncompact) manifolds that CkNN is the unique
unweighted construction that yields a geometry consistent with the connected
components of the underlying manifold in the limit of large data. Thus CkNN
produces a single graph that captures all topological features simultaneously,
in contrast to persistent homology, which represents each homology generator at
a separate scale. As applications we derive a new fast clustering algorithm and
a method to identify patterns in natural images topologically. Finally, we
conjecture that CkNN is topologically consistent, meaning that the homology of
the Vietoris-Rips complex (implied by the graph Laplacian) converges to the
homology of the underlying manifold (implied by the Laplace-de Rham operators)
in the limit of large data.


title: Abelian $p$-extensions and additive polynomials

abstract:
  In this work we present some arithmetic properties of families of abelian
$p$--extensions of global function fields, among which are their generators and
their type of ramification and decomposition.


title: Active Long Term Memory Networks

abstract:
  Continual Learning in artificial neural networks suffers from interference
and forgetting when different tasks are learned sequentially. This paper
introduces the Active Long Term Memory Networks (A-LTM), a model of sequential
multi-task deep learning that is able to maintain previously learned
association between sensory input and behavioral output while acquiring knew
knowledge. A-LTM exploits the non-convex nature of deep neural networks and
actively maintains knowledge of previously learned, inactive tasks using a
distillation loss. Distortions of the learned input-output map are penalized
but hidden layers are free to transverse towards new local optima that are more
favorable for the multi-task objective. We re-frame the McClelland's seminal
Hippocampal theory with respect to Catastrophic Inference (CI) behavior
exhibited by modern deep architectures trained with back-propagation and
inhomogeneous sampling of latent factors across epochs. We present empirical
results of non-trivial CI during continual learning in Deep Linear Networks
trained on the same task, in Convolutional Neural Networks when the task shifts
from predicting semantic to graphical factors and during domain adaptation from
simple to complex environments. We present results of the A-LTM model's ability
to maintain viewpoint recognition learned in the highly controlled iLab-20M
dataset with 10 object categories and 88 camera viewpoints, while adapting to
the unstructured domain of Imagenet with 1,000 object categories.


title:
Load-depth sensing of isotropic, linear viscoelastic materials using
  rigid axisymmetric indenters

abstract:
  An indentation experiment involves five variables: indenter shape, material
behavior of the substrate, contact size, applied load and indentation depth.
Only three variable are known afterwards, namely, indenter shape, plus load and
depth as function of time. As the contact size is not measured and the
determination of the material properties is the very aim of the test; two
equations are needed to obtain a mathematically solvable system.
  For elastic materials, the contact size can always be eliminated once and for
all in favor of the depth; a single relation between load, depth and material
properties remains with the latter variable as unknown.
  For viscoelastic materials where hereditary integrals model the constitutive
behavior, the relation between depth and contact size usually depends also on
the (time-dependent) properties of the material. Solving the inverse problem,
i.e., determining the material properties from the experimental data, therefore
needs both equations. Extending Sneddon's analysis of the indentation problem
for elastic materials to include viscoelastic materials, the two equations
mentioned above are derived. To find the time dependence of the material
properties the feasibility of Golden and Graham's method of decomposing
hereditary integrals (J.M. Golden and G.A.C. Graham. Boundary value problems in
linear viscoelasticity, Springer, 1988) is investigated and applied to a single
load-unload process and to sinusoidally driven stationary state indentation
processes.


title:
Mobius disjointness for interval exchange transformations on three
  intervals

abstract:
  We show that Sarnak's conjecture on Mobius disjointness holds for interval
exchange transformations on three intervals (3-IETs) that satisfy a mild
diophantine condition.


title: The Galactic Nova Rate Revisited

abstract:
  Despite its fundamental importance, a reliable estimate of the Galactic nova
rate has remained elusive. Here, the overall Galactic nova rate is estimated by
extrapolating the observed rate for novae reaching $m\leq2$ to include the
entire Galaxy using a two component disk plus bulge model for the distribution
of stars in the Milky Way. The present analysis improves on previous work by
considering important corrections for incompleteness in the observed rate of
bright novae and by employing a Monte Carlo analysis to better estimate the
uncertainty in the derived nova rates. Several models are considered to account
for differences in the assumed properties of bulge and disk nova populations
and in the absolute magnitude distribution. The simplest models, which assume
uniform properties between bulge and disk novae, predict Galactic nova rates of
$\sim$50 to in excess of 100 per year, depending on the assumed incompleteness
at bright magnitudes. Models where the disk novae are assumed to be more
luminous than bulge novae are explored, and predict nova rates up to 30% lower,
in the range of $\sim$35 to $\sim$75 per year. An average of the most plausible
models yields a rate of $50_{-23}^{+31}$ yr$^{-1}$, which is arguably the best
estimate currently available for the nova rate in the Galaxy. Virtually all
models produce rates that represent significant increases over recent
estimates, and bring the Galactic nova rate into better agreement with that
expected based on comparison with the latest results from extragalactic
surveys.


title: Structure Learning in Graphical Modeling

abstract:
  A graphical model is a statistical model that is associated to a graph whose
nodes correspond to variables of interest. The edges of the graph reflect
allowed conditional dependencies among the variables. Graphical models admit
computationally convenient factorization properties and have long been a
valuable tool for tractable modeling of multivariate distributions. More
recently, applications such as reconstructing gene regulatory networks from
gene expression data have driven major advances in structure learning, that is,
estimating the graph underlying a model. We review some of these advances and
discuss methods such as the graphical lasso and neighborhood selection for
undirected graphical models (or Markov random fields), and the PC algorithm and
score-based search methods for directed graphical models (or Bayesian
networks). We further review extensions that account for effects of latent
variables and heterogeneous data sources.


title:
Example Demonstrating the Application of Small-gain and Density
  Propagation Conditions for Interconnections

abstract:
  This work provides an example that motivates and illustrates theoretical
results related to a combination of small-gain and density propagation
conditions. Namely, in case the small-gain fails to hold at certain points or
intervals the density propagation condition can be applied to assure global
stability properties. We repeat the theoretical results here and demonstrate
how they can be applied in the proposed example.


title:
Precision gaugino mass measurements as a probe of large trilinear soft
  terms at ILC

abstract:
  In supersymmetric models with radiatively-driven naturalness, higgsino-like
electroweak-inos (EW-inos) are expected to lie in a mass range 100--300 GeV,
the lighter the more natural. Such states can be pair-produced at high rates at
ILC where their masses are nearly equal to the value of the superpotential mu
parameter while their mass splittings depend on the gaugino masses M_1 and M_2.
The gaugino masses in turn depend on trilinear soft terms---the A parameters,
which are expected to lie in the multi-TeV range owing to the 125 GeV Higgs
mass---via two-loop contributions to renormalization group running. We examine
the extent to which ILC is sensitive to large A-terms via precision EW-ino mass
measurement. Extraction of gaugino masses at the percent level should allow for
interesting probes of large trilinear soft SUSY breaking terms under the
assumption of unified gaugino masses.


title:
Recent galaxy mergers and residual star formation of red sequence
  galaxies in galaxy clusters

abstract:
  This study explored the GALEX ultraviolet (UV) properties of optical red
sequence galaxies in 4 rich Abell clusters at z \leq 0.1. In particular, we
tried to find a hint of merger-induced recent star formation (RSF) in red
sequence galaxies. Using the NUV - r' colors of the galaxies, RSF fractions
were derived based on various criteria for post-merger galaxies and normal
galaxies. Following k-correction, about 36% of the post-merger galaxies were
classified as RSF galaxies with a conservative criterion (NUV - r' \leq 5), and
that number was doubled (~ 72%) when using a generous criterion (NUV - r' \leq
5.4). The trend was the same when we restricted the sample to galaxies within
0.5xR_{200}. Post-merger galaxies with strong UV emission showed more violent,
asymmetric features in the deep optical images. The RSF fractions did not show
any trend along the clustocentric distance within R_{200}. We performed a
Dressler-Shectman test to check whether the RSF galaxies had any correlation
with the sub-structures in the galaxy clusters. Within R_{200} of each cluster,
the RSF galaxies did not appear to be preferentially related to the clusters'
sub-structures. Our results suggested that only 30% of RSF red sequence
galaxies show morphological hints of recent galaxy mergers. This implies that
internal processes (e.g., stellar mass-loss or hot gas cooling) for the supply
of cold gas to early-type galaxies may play a significant role in the residual
star formation of early-type galaxies at a recent epoch.


title:
Conditions Implying Energy Equality for Weak Solutions of the
  Navier--Stokes Equations

abstract:
  When a Leray--Hopf weak solution to the NSE has a singularity set $S$ of
dimension $d$ less than $3$---for example, a suitable weak solution---we find a
family of new $L^q L^p$ conditions that guarantee validity of the energy
equality. Our conditions surpass the classical Lions--Lady\v{z}enskaja $L^4
L^4$ result in the case $d<1$. Additionally, we establish energy equality in
certain cases of Type-I blowup. The results are also extended to the NSE with
fractional power of the Laplacian below $1$.


title:
Strong coupling of Rydberg atoms and surface phonon polaritons on
  piezoelectric superlattices

abstract:
  We propose a hybrid quantum system where the strong coupling regime can be
achieved between a Rydberg atomic ensemble and propagating surface phonon
polaritons on a piezoelectric superlattice. By exploiting the large electric
dipole moment and long lifetime of Rydberg atoms as well as tightly confined
surface phonon polariton modes, it is possible to achieve a coupling constant
far exceeding the relevant decay rates. The frequency of the surface mode can
be selected so it is resonant with a Rydberg transition by engineering the
piezoelectric superlattice. We describe a way to observe the Rabi splitting
associated with the strong coupling regime under realistic experimental
conditions. The system can be viewed as a new type of optomechanical system.


title: Optimization on Sparse Random Hypergraphs and Spin Glasses

abstract:
  We establish that in the large degree limit, the value of certain
optimization problems on sparse random hypergraphs is determined by an
appropriate Gaussian optimization problem. This approach was initiated in Dembo
et. al.(2016) for extremal cuts of graphs. The usefulness of this technique is
further illustrated by deriving the optimal value for Max $q$-cut on
Erd\H{o}s-R\'enyi and random regular graphs, Max XORSAT on Erd\H{o}s-R\'enyi
hypergraphs, and the min-bisection for the Stochastic Block Model.


title: Generic Torus Canards

abstract:
  Torus canards are solutions of slow/fast systems that alternate between
attracting and repelling manifolds of limit cycles of the fast subsystem. A
relatively new dynamic phenomenon, torus canards have been found in neural
applications to mediate the transition from spiking to bursting via
amplitude-modulated spiking. In $\mathbb{R}^3$, torus canards are degenerate:
they require one-parameter families of 2-fast/1-slow systems in order to be
observed and even then, they only occur on exponentially thin parameter
intervals. The addition of a second slow variable unfolds the torus canard
phenomenon, making them generic and robust. That is, torus canards in slow/fast
systems with (at least) two slow variables occur on open parameter sets. So
far, generic torus canards have only been studied numerically, and their
behaviour has been inferred based on averaging and canard theory. This
approach, however, has not been rigorously justified since the averaging method
breaks down near a fold of periodics, which is exactly where torus canards
originate. In this work, we combine techniques from Floquet theory, averaging
theory, and geometric singular perturbation theory to show that the average of
a torus canard is a folded singularity canard. In so doing, we devise an
analytic scheme for the identification and topological classification of torus
canards in $\mathbb{R}^4$. We demonstrate the predictive power of our results
in a model for intracellular calcium dynamics, where we explain the mechanisms
underlying a novel class of elliptic bursting rhythms, called
amplitude-modulated bursting, by constructing the torus canard analogues of
mixed-mode oscillations. We also make explicit the connection between our
results here with prior studies of torus canards and torus canard explosion in
$\mathbb{R}^3$, and discuss how our methods can be extended to slow/fast
systems of arbitrary (finite) dimension.


title: Competition in periodic media: I -- Existence of pulsating fronts

abstract:
  This paper is concerned with the existence of pulsating front solutions in
space-periodic media for a bistable two-species competition--diffusion
Lotka--Volterra system. Considering highly competitive systems, a simple "high
frequency or small amplitudes" algebraic sufficient condition for the existence
of pulsating fronts is stated. This condition is in fact sufficient to
guarantee that all periodic coexistence states vanish and become unstable as
the competition becomes large enough.


title:
Observables Processing for the Helioseismic and Magnetic Imager
  Instrument on the Solar Dynamics Observatory

abstract:
  NASA's Solar Dynamics Observatory (SDO) was launched 11 February 2010 with 3
instruments on board, including the Helioseismic and Magnetic Imager (HMI).
Since beginning normal operations on 1 May 2010, HMI has observed the Sun's
entire visible disk almost continuously. HMI collects sequences of polarized
filtergrams taken at a fixed cadence with two 4096 x 4096 cameras from which
are computed arcsecond-resolution maps of photospheric observables: the
line-of-sight (LoS) velocity and magnetic field, continuum intensity, line
width, line depth, and the Stokes polarization parameters, I Q U V, at 6
wavelengths. Two processing pipelines implemented at the SDO Joint Science
Operations Center (JSOC) at Stanford University compute observables from
calibrated Level-1 filtergrams. One generates LoS quantities every 45s, and the
other, primarily for the vector magnetic field, computes averages on a 720s
cadence. Corrections are made for static and temporally changing CCD
characteristics, bad pixels, image alignment and distortion, polarization
irregularities, filter-element uncertainty and non-uniformity, as well as
Sun-spacecraft velocity. This report explains issues affecting the resulting
physical quantities, describes the impact of regular updates to the instrument
calibration, and shows how the computations are optimized for actual HMI
observations. During the 5 years of the SDO prime mission, regular calibration
sequences have been used to regularly improve and update the instrument
calibration and to monitor instrument changes. The instrument more than
satisfies the original specifications for data quality and continuity. The
procedures described here still have significant room for improvement. The most
significant remaining systematic errors are associated with the spacecraft
orbital velocity.


title:
Moduli space of irregular singular parabolic connections of generic
  ramified type on a smooth projective curve

abstract:
  We give an algebraic construction of the moduli space of irregular singular
connections of generic ramified type on a smooth projective curve. We prove
that the moduli space is smooth and give its dimension. Under the assumption
that the exponent of ramified type is generic, we give an algebraic symplectic
form on the moduli space.


title: On the largest reduced neighborhood clique cover number of a graph

abstract:
  Let $G$ be a graph and $t\ge 0$. A new graph parameter termed the largest
reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$,
is introduced. Specifically, ${\hat\beta}_t(G)$ is the largest, overall
$t$-shallow minors $H$ of $G$, of the smallest number of cliques that can cover
any closed neighborhood of a vertex in $H$. We verify that ${\hat\beta}_t(G)=1$
when $G$ is chordal, and, ${\hat\beta}_t(G)\le s$, where $G$ is an
incomparability graph that does not have a $t-$shallow minor which is
isomorphic to an induced star on $s$ leaves. Moreover, general properties of
${\hat\beta}_t(G)$ including the connections to the greatest reduced average
density of $G$, or $\bigtriangledown_t(G)$ are studied and investigated. For
instance we show ${{\hat\beta}_t(G)\over 2}\le \bigtriangledown_t(G)\le
p.{\hat\beta}_t(G),$ where $p$ is the size of a largest complete graph which is
a $t-minor$ of $G$. Additionally we prove that largest ratio of any minimum
clique cover to the maximum independent set taken overall $t-$minors of $G$ is
a lower bound for ${\hat\beta}_t(G)$. We further introduce the class of bounded
neighborhood clique cover number for which ${\hat\beta}_t(G)$ has a finite
value for each $t\ge 0$ and verify the membership of geometric intersection
graphs of fat objects (with no restrictions on the depth) to this class. The
results support the conjecture that the class graphs with polynomial bounded
neighborhood clique cover number may have separator theorems with respect to
certain measures.


title: Energy Efficiency in Multicast Multihop D2D Networks

abstract:
  As the demand of mobile devices (MDs) for data services is explosively
increasing, traditional offloading in the cellular networks is facing the
contradiction of energy efficiency and quality of service. Device-to-device
(D2D) communication is considered as an effective solution. This work
investigates a scenario where the MDs have the same demand for common content
and they cooperate to deliver it using multicast multihop relaying. We focus on
the problem of total power minimization by grouping the MDs in multihop D2D
networks, while maintaining the minimum rate requirement of each MD. As the
problem is shown to be NP-complete and the optimal solution can not be found
efficiently, two greedy algorithms are proposed to solve this problem in
polynomial time. Simulation results demonstrate that lots of power can be saved
in the content delivery situation using multihop D2D communication, and the
proposed algorithms are suitable for different situations with different
advantages.


title: Entrainment of traveling waves to rhythmic motor acts

abstract:
  We hypothesized that rhythmic motor acts entrain neural oscillations in
speech production brain regions. We tested this hypothesis in an experiment
where a subject produced consonant-vowel (CV) syllables in a rhythmic fashion,
while we performed ECoG recordings. Over the ventral sensorimotor cortex (vSMC)
we detected significant concentration of phase across trials at the specific
frequency of speech production. We also observed amplitude modulations. In
addition we found significant coupling between the phase of brain oscillations
at the frequency of speech production and their amplitude in the high-gamma
range (i.e., phase-amplitude coupling, PAC). Furthermore, we saw that brain
oscillations at the frequency of speech production organized as traveling waves
(TWs), synchronized to the rhythm of speech production. It has been
hypothesized that PAC is a mechanism to allow low-frequency oscillations to
synchronize with high-frequency neural activity so that spiking occurs at
behaviorally relevant times. If this hypothesis is true, when PAC coexists with
TWs, we expect a specific organization of PAC curves. We observed this
organization experimentally and verified that the peaks of high-gamma
oscillations, and therefore spiking, occur at the same times across electrodes.
Importantly, we observed that these spiking times were synchronized with the
rhythm of speech production. To our knowledge, this is the first report of
motor actions organizing (a) the phase coherence of low-frequency brain
oscillations, (b) the coupling between the phase of these oscillations and the
amplitude of high-frequency oscillations, and (c) TW. It is also the first
demonstration that TWs induce an organization of PAC so that spiking across
spatial locations is synchronized to behaviorally relevant times.


title:
P4QS: A Peer to Peer Privacy Preserving Query Service for Location-Based
  Mobile Applications

abstract:
  The location-based services provide an interesting combination of cyber and
physical worlds. However, they can also threaten the users' privacy. Existing
privacy preserving protocols require trusted nodes, with serious security and
computational bottlenecks. In this paper, we propose a novel distributed
anonymizing protocol based on peer-to-peer architecture. Each mobile node is
responsible for anonymizing a specific zone. The mobile nodes collaborate in
anonymizing their queries, without the need not get access to any information
about each other. In the proposed protocol, each request will be sent with a
randomly chosen ticket. The encrypted response produced by the server is sent
to a particular mobile node (called broker node) over the network, based on the
hash value of this ticket. The user will query the broker to get the response.
All parts of the messages are encrypted except the fields required for the
anonymizer and the broker. This will secure the packet exchange over the P2P
network. The proposed protocol was implemented and tested successfully, and the
experimental results showed that it could be deployed efficiently to achieve
user privacy in location-based services.


title: Abelian Decomposition and Glueball-Quarkonium Mixing in QCD

abstract:
  The Abelian decomposition of QCD which decomposes the gluons to the color
neutral binding gluons (the neurons) and the colored valence gluons (the
chromons) gauge independently naturally generalizes the quark model to the
quark and chromon model which could play the central role in hadron
spectroscopy. We discuss the color reflection symmetry, the fundamental
symmetry of the quark and chromon model, and explain how it describes the
glueballs and the glueball-quarkonium mixing in QCD. We present the numerical
analysis of glueball-quarkonium mixing in $0^{++}$, $2^{++}$, and $0^{-+}$
sectors below 2 GeV, and show that in the $0^{++}$ sector $f_0(500)$ and
$f_0(1500)$, in the $2^{++}$ sector $f_2(1950)$, and in the $0^{-+}$ sector
$\eta(1405)$ and $\eta(1475)$ could be identified as predominantly the glueball
states. We discuss the physical implications of our result.


title:
Pieri rules for classical groups and equinumeration between generalized
  oscillating tableaux and semistandard tableaux

abstract:
  We present several equinumerous results between generalized oscillating
tableaux and semistandard tableaux and give a representation-theoretical proof
to them. As one of the key ingredients of the proof, we provide Pieri rules for
the symplectic and orthogonal groups.


title:
Remarks on the Gauss images of complete minimal surfaces in Euclidean
  four-space

abstract:
  We perform a systematic study of the image of the Gauss map for complete
minimal surfaces in Euclidean four-space. In particular, we give a geometric
interpretation of the maximal number of exceptional values of the Gauss map of
a complete orientable minimal surface in Euclidean four-space. We also provide
optimal results for the maximal number of exceptional values of the Gauss map
of a complete minimal Lagrangian surface in the complex two-space and the
generalized Gauss map of a complete nonorientable minimal surface in Euclidean
four-space.


title: Oblique boundary value problems for augmneted Hessian equations II

abstract:
  In this paper, we continue our investigations into the global theory of
oblique boundary value problems for augmented Hessian equations. We construct a
global barrier function in terms of an admissible function in a uniform way
when the matrix function in the augmented Hessian is only assumed regular. This
enables us to derive global second derivative estimates in terms of boundary
estimates which are then obtained by strengthening the concavity or
monotonicity conditions in our previous work on the strictly regular case.
Finally we give some applications to existence theorems which embrace standard
Hessian equations as special cases.


title: SE3-Nets: Learning Rigid Body Motion using Deep Neural Networks

abstract:
  We introduce SE3-Nets, which are deep neural networks designed to model and
learn rigid body motion from raw point cloud data. Based only on sequences of
depth images along with action vectors and point wise data associations,
SE3-Nets learn to segment effected object parts and predict their motion
resulting from the applied force. Rather than learning point wise flow vectors,
SE3-Nets predict SE3 transformations for different parts of the scene. Using
simulated depth data of a table top scene and a robot manipulator, we show that
the structure underlying SE3-Nets enables them to generate a far more
consistent prediction of object motion than traditional flow based networks.
Additional experiments with a depth camera observing a Baxter robot pushing
objects on a table show that SE3-Nets also work well on real data.


title: Energy-Efficient Transmission Design in Non-Orthogonal Multiple Access

abstract:
  Non-orthogonal multiple access (NOMA) is considered as a promising technology
for improving the spectral efficiency (SE) in 5G. In this correspondence, we
study the benefit of NOMA in enhancing energy efficiency (EE) for a multi-user
downlink transmission, where the EE is defined as the ratio of the achievable
sum rate of the users to the total power consumption. Our goal is to maximize
the EE subject to a minimum required data rate for each user, which leads to a
non-convex fractional programming problem. To solve it, we first establish the
feasible range of the transmitting power that is able to support each user's
data rate requirement. Then, we propose an EE-optimal power allocation strategy
that maximizes the EE. Our numerical results show that NOMA has superior EE
performance in comparison with conventional orthogonal multiple access (OMA).


title:
Breaking the rotating wave approximation for a strongly-driven, dressed,
  single electron spin

abstract:
  We investigate the dynamics of a strongly-driven, microwave-dressed,
donor-bound electron spin qubit in silicon. A resonant oscillating magnetic
field $B_1$ is used to dress the electron spin and create a new quantum system
with a level splitting proportional to $B_1$. The dressed two-level system can
then be driven by modulating the detuning $\Delta\nu$ between the microwave
source frequency $\nu_{\rm MW}$ and the electron spin transition frequency
$\nu_e$ at the frequency of the level splitting. The resulting dressed qubit
Rabi frequency $\Omega_{R\rho}$ is defined by the modulation amplitude, which
can be made comparable to the level splitting using frequency modulation on the
microwave source. This allows us to investigate the regime where the rotating
wave approximation breaks down, without requiring microwave power levels that
would be incompatible with a cryogenic environment. We observe clear deviations
from normal Rabi oscillations and can numerically simulate the time evolution
of the states in excellent agreement with the experimental data.


title: Nonparametric Bayes models for mixed-scale longitudinal surveys

abstract:
  Modeling and computation for multivariate longitudinal surveys have proven
challenging, particularly when data are not all continuous and Gaussian but
contain discrete measurements. In many social science surveys, study
participants are selected via complex survey designs such as stratified random
sampling, leading to discrepancies between the sample and population, which are
further compounded by missing data and loss to follow up. Survey weights are
typically constructed to address these issues, but it is not clear how to
include them in models. Motivated by data on sexual development, we propose a
novel nonparametric approach for mixed-scale longitudinal data in surveys. In
the proposed approach, the mixed-scale multivariate response is expressed
through an underlying continuous variable with dynamic latent factors inducing
time-varying associations. Bias from the survey design is adjusted for in
posterior computation relying on a Markov chain Monte Carlo algorithm. The
approach is assessed in simulation studies, and applied to the National
Longitudinal Study of Adolescent to Adult Health.


title:
Deep Learning Convolutional Networks for Multiphoton Microscopy
  Vasculature Segmentation

abstract:
  Recently there has been an increasing trend to use deep learning frameworks
for both 2D consumer images and for 3D medical images. However, there has been
little effort to use deep frameworks for volumetric vascular segmentation. We
wanted to address this by providing a freely available dataset of 12 annotated
two-photon vasculature microscopy stacks. We demonstrated the use of deep
learning framework consisting both 2D and 3D convolutional filters (ConvNet).
Our hybrid 2D-3D architecture produced promising segmentation result. We
derived the architectures from Lee et al. who used the ZNN framework initially
designed for electron microscope image segmentation. We hope that by sharing
our volumetric vasculature datasets, we will inspire other researchers to
experiment with vasculature dataset and improve the used network architectures.


title:
A level-set-based topology optimisation for acoustic-elastic coupled
  problems with a fast BEM-FEM solver

abstract:
  This paper presents a structural optimisation method in three-dimensional
acoustic-elastic coupled problems. The proposed optimisation method finds an
optimal allocation of elastic materials which reduces the sound level on some
fixed observation points. In the process of the optimisation, configuration of
the elastic materials is expressed with a level set function, and the
distribution of the level set function is iteratively updated with the help of
the topological derivative. The topological derivative is associated with state
and adjoint variables which are the solutions of the acoustic-elastic coupled
problems. In this paper, the acoustic-elastic coupled problems are solved by a
BEM-FEM coupled solver, in which the fast multipole method (FMM) and a
multi-frontal solver for sparse matrices are efficiently combined. Along with
the detailed formulations for the topological derivative and the BEM-FEM
coupled solver, we present some numerical examples of optimal designs of
elastic sound scatterer to manipulate sound waves, from which we confirm the
effectiveness of the present method.


title: From 3D topological quantum field theories to 4D models with defects

abstract:
  (2+1) dimensional topological quantum field theories with defect excitations
are by now quite well understood, while many questions are still open for (3+1)
dimensional TQFTs. Here we propose a strategy to lift states and operators of a
(2+1) dimensional TQFT to states and operators of a (3+1) dimensional theory
with defects. The main technical tool are Heegard splittings, which allow to
encode the topology of a three--dimensional manifold with line defects into a
two--dimensional Heegard surface. We apply this idea to the example of BF
theory which describes locally flat connections. This shows in particular how
the curvature excitation generating surface operators of the (3+1) dimensional
theory can be obtained from closed ribbon operators of the (2+1) dimensional BF
theory. We hope that this technique allows the construction and study of more
general models based on unitary fusion categories.

categories: hep-th cond-mat.str-el gr-qc math-ph math.MP


title: Anarchy in Tor: Performance Cost of Decentralization

abstract:
  Like many routing protocols, the Tor anonymity network has decentralized path
selection, in clients locally and independently choose paths. As a result,
network resources may be left idle, leaving the system in a suboptimal state.
This is referred to as the price of anarchy, where agents acting in their own
self interest can make poor decisions when viewed in a global context. In this
paper we explore the cost of anarchy in Tor by examining the potential
performance increases that can be gained by centrally optimizing circuit and
relay selection using global knowledge. In experiments with both offline and
online algorithms, we show that centrally coordinated clients can achieve up to
75% higher bandwidth compared to traditional Tor. Drawing on these findings, we
design and evaluate a decentralized version of our online algorithm, in which
relays locally distribute information enabling clients to make smarter
decisions locally and perform downloads 10-60% faster. Finally, we perform a
privacy analysis of the decentralized algorithm against a passive and active
adversary trying to reduce anonymity of clients and increase their view of the
Tor network. We conclude that this decentralized algorithm does not enable new
attacks, while providing significantly higher performance.


title:
A Generalized Benjamini-Hochberg Procedure for Multivariate Hypothesis
  Testing

abstract:
  The introduction of the false discovery rate (FDR) by Benjamini and Hochberg
has spurred a great interest in developing methodologies to control the FDR in
various settings. The majority of existing approaches, however, address the FDR
control for the case where an appropriate univariate test statistic is
available. Modern hypothesis testing and data integration applications, on the
other hand, routinely involve multivariate test statistics. The goal, in such
settings, is to combine the evidence for each hypothesis and achieve greater
power, while controlling the number of false discoveries. This paper considers
data-adaptive methods for constructing nested rejection regions based on
multivariate test statistics (z-values). It is proved that the FDR can be
controlled for appropriately constructed rejection regions, even when the
regions depend on data and are hence random. This flexibility is then exploited
to develop optimal multiple comparison procedures in higher dimensions, where
the distribution of non-null z-values is unknown. Results are illustrated using
simulated and real data.


title:
Angle-of-Attack Modulation in Trajectory Tracking for a Reusable Launch
  Vehicle

abstract:
  This paper deals with the problem of angle-of-attack modulation with the aim
of enhancing transient performance of entry guidance during bank reversals,
while compensating adverse effects of fast time-varying transient disturbances.
An extended single-input/single-output system is developed in the velocity
domain by means of a dynamic extension technique, and explicitly captures the
trajectory dynamics of angle-of-attack modulation. A normal form for this
extended system is derived for the sake of employing a feedback linearization
controller. Further, the control characteristics of angle-of-attack modulation
is found to be a non-minimum phase behavior under two common conditions in a
near- equilibrium glide flight. Therefore, the issue of angle-of-attack
modulation is formulated as robust output stabilization of the non-minimum
phase system. A disturbance observer-based feedback linearization technique is
used to design a robustly dynamical output-feedback controller for
angle-of-attack modulation, and an internal-state feedback controller for
bank-angle modulation is used to stabilize the unstable internal dynamics.
Numerical simulations are conducted to demonstrate that the performance of the
proposed method of angle-of-attack modulation is enhanced compared to the
existing shuttle method.


title: A Quantitative Oppenheim Theorem for generic ternary quadratic forms

abstract:
  We prove a quantitative version of Oppenheim's conjecture for generic ternary
indefinite quadratic forms. Our results are inspired by and analogous to recent
results for diagonal quadratic forms due to Bourgain.


title:
About the isocurvature tension between axion and high scale inflationary
  models

abstract:
  The present work suggests that the isocurvature tension between axion and
high energy inflationary scenarios may be avoided by considering a double field
inflationary model involving the hidden Peccei-Quinn Higgs and the Standard
Model one. Some terms in the lagrangian we propose explicitly violate the
Peccei-Quinn symmetry but, at the present era, their effect is completely
negligible. The resulting mechanism allows a large value for the axion
constant, of the order $f_a\sim M_p$, thus the axion isocurvature fluctuations
are suppressed even when the scale of inflation $H_{inf}$ is very high, of the
order of $H_{inf}\sim M_{gut}$. This numerical value is typical in Higgs
inflationary models. An analysis about topological defect formation in this
scenario is also performed, and it is suggested that, under certain
assumptions, their effect is not catastrophic from the cosmological point of
view.


title: Volume monogamy of quantum steering ellipsoids for multi-qubit systems

abstract:
  The quantum steering ellipsoid can be used to visualise two-qubit states, and
thus provides a generalisation of the Bloch picture for the single qubit.
Recently, a monogamy relation for the volumes of steering ellipsoids has been
derived for pure 3-qubit states and shown to be stronger than the celebrated
Coffman-Kundu-Wootters (CKW) inequality. We first demonstrate the close
connection between this volume monogamy relation and the classification of pure
3-qubit states under stochastic local operations and classical communication
(SLOCC). We then show that this monogamy relation does not hold for general
mixed 3-qubit states and derive a weaker monogamy relation that does hold for
such states. We also prove a volume monogamy relation for pure 4-qubit states,
and generalize our 3-qubit inequality to n qubits. Finally, we study the effect
of noise on the quantum steering ellipsoid and find that the volume of any
two-qubit state is non-increasing when the state is exposed to arbitrary local
noise. This implies that any volume monogamy relation for a given class of
multi-qubit states remains valid under the addition of local noise. We
investigate this quantitatively for the experimentally relevant example of
isotropic noise.


title:
Nonlinear Stochastic Dynamics of Complex Systems, III: Noneqilibrium
  Thermodynamics of Self-Replication Kinetics

abstract:
  We briefly review the recently developed, Markov process based isothermal
chemical thermodynamics for nonlinear, driven mesoscopic kinetic systems. Both
the instantaneous Shannon entropy {\boldmath $S[p_{\alpha}(t)]$} and relative
entropy {\boldmath $F[p_{\alpha}(t)]$}, defined based on probability
distribution {\boldmath $\{p_{\alpha}(t)\}$}, play prominent roles. The theory
is general; and as a special case when a chemical reaction system is situated
in an equilibrium environment, it agrees perfectly with Gibbsian chemical
thermodynamics: {\boldmath $k_BS$} and {\boldmath $k_BTF$} become thermodynamic
entropy and free energy, respectively. We apply this theory to a fully
reversible autocatalytic reaction kinetics, represented by a
Delbr\"{u}ck-Gillespie process, in a chemostatic nonequilibrium environment.
The open, driven chemical system serves as an archetype for biochemical
self-replication. The significance of {\em thermodynamically consistent}
kinetic coarse-graining is emphasized. In a kinetic system where death of a
biological organism is treated as the reversal of its birth, the meaning of
mathematically emergent "dissipation", which is not related to the heat
measured in terms of {\boldmath $k_BT$}, remains to be further investigated.


title:
Alternative difference analysis scheme combining R-space EXAFS fit with
  global optimization XANES fit for X-ray transient absorption spectroscopy

abstract:
  Time-resolved X-ray absorption spectroscopy (TR-XAS), based on
laser-pump/X-ray probe method, is powerful in capturing the change of
geometrical and electronic structure of the absorbing atom upon excitation.
TR-XAS data analysis is generally performed on the laser-on minus laser-off
difference spectrum. Here we present a new analysis scheme for the TR-XAS
difference fitting in both the Extended X-Ray Absorption Fine Structure (EXAFS)
and the X-ray Absorption Near Edge Structure (XANES) region. R-space EXAFS
difference fitting could quickly give main quantitative structure change of the
first shell and provide reliable constraint on the range of the variables in
XANES fit. XANES fitting part introduces global non-derivative optimization
algorithm and optimizes the local structure change in a flexible way where both
the core XAS calculation package and the search method in the fitting shell are
changeable. The scheme was applied to the TR-XAS difference analysis of
Fe(phen)3 spin crossover complex and yielded the reliable distance change and
the excitation population.


title: Progressive Attention Networks for Visual Attribute Prediction

abstract:
  We propose a novel attention model that can accurately attends to target
objects of various scales and shapes in images. The model is trained to
gradually suppress irrelevant regions in an input image via a progressive
attentive process over multiple layers of a convolutional neural network. The
attentive process in each layer determines whether to pass or block features at
certain spatial locations for use in the subsequent layers. The proposed
progressive attention mechanism works well especially when combined with hard
attention. We further employ local contexts to incorporate neighborhood
features of each location and estimate a better attention probability map. The
experiments on synthetic and real datasets show that the proposed attention
networks outperform traditional attention methods in visual attribute
prediction tasks.


title: Optimal quantum networks and one-shot entropies

abstract:
  We develop a semidefinite programming method for the optimization of quantum
networks, including both causal networks and networks with indefinite causal
structure. Our method applies to a broad class of performance measures, defined
operationally in terms of interactive tests set up by a verifier. We show that
the optimal performance is equal to a max relative entropy, which quantifies
the informativeness of the test. Building on this result, we extend the notion
of conditional min-entropy from quantum states to quantum causal networks. The
optimization method is illustrated in a number of applications, including the
inversion, charge conjugation, and controlization of an unknown unitary
dynamics. In the non-causal setting, we show a proof-of-principle application
to the maximization of the winning probability in a non-causal quantum game.

categories: quant-ph cs.IT cs.NI math-ph math.IT math.MP


title:
Efficient quadratic penalization through the partial minimization
  technique

abstract:
  Common computational problems, such as parameter estimation in dynamic models
and PDE constrained optimization, require data fitting over a set of auxiliary
parameters subject to physical constraints over an underlying state. Naive
quadratically penalized formulations, commonly used in practice, suffer from
inherent ill-conditioning. We show that surprisingly the partial minimization
technique regularizes the problem, making it well-conditioned. This viewpoint
sheds new light on variable projection techniques, as well as the penalty
method for PDE constrained optimization, and motivates robust extensions. In
addition, we outline an inexact analysis, showing that the partial minimization
subproblem can be solved very loosely in each iteration. We illustrate the
theory and algorithms on boundary control, optimal transport, and parameter
estimation for robust dynamic inference.


title: Deep Successor Reinforcement Learning

abstract:
  Learning robust value functions given raw observations and rewards is now
possible with model-free and model-based deep reinforcement learning
algorithms. There is a third alternative, called Successor Representations
(SR), which decomposes the value function into two components -- a reward
predictor and a successor map. The successor map represents the expected future
state occupancy from any given state and the reward predictor maps states to
scalar rewards. The value function of a state can be computed as the inner
product between the successor map and the reward weights. In this paper, we
present DSR, which generalizes SR within an end-to-end deep reinforcement
learning framework. DSR has several appealing properties including: increased
sensitivity to distal reward changes due to factorization of reward and world
dynamics, and the ability to extract bottleneck states (subgoals) given
successor maps trained under a random policy. We show the efficacy of our
approach on two diverse environments given raw pixel observations -- simple
grid-world domains (MazeBase) and the Doom game engine.


title: Nonequilibrium transient dynamics of photon statistics

abstract:
  We investigate the transient dynamics of photon statistics through two-time
correlation functions for optical fields. We find that the transient
correlations at different time t yield a smooth transition from antibunching to
bunching photon statistics in the weak system-environment coupling regime. In
the strong-coupling regime, the two-time correlations exhibit
bunching-antibunching oscillations that persists both in the transient process
and in the steady-state limit. The photon bunching-antibunching oscillations is
a manifestation of strong non-Markovian dynamics, where the system remains in
nonequilibrium from its environment. We also find that the antibunching to
bunching transition in the weak-coupling regime and the bunching-antibunching
oscillation in the strong-coupling regime are strongly influenced by the
initial environment temperature.


title:
Search for light curve modulations among Kepler candidates. Three very
  low-mass transiting companions

abstract:
  Light curve modulations in the sample of Kepler planet candidates allows the
disentangling of the nature of the transiting object by photometrically
measuring its mass. This is possible by detecting the effects of the
gravitational pull of the companion (ellipsoidal modulations) and in some
cases, the photometric imprints of the Doppler effect when observing in a broad
band (Doppler beaming). We aim to photometrically unveil the nature of some
transiting objects showing clear modulations in the phase-folded Kepler light
curve. We selected a subsample among the large crop of Kepler objects of
interest (KOIs) based on their chances to show detectable light curve
modulations, i.e., close ($a<12~R_{\star}$) and large (in terms of radius)
candidates. We modeled their phase-folded light curves with consistent
equations for the three effects, namely, reflection, ellipsoidal and beaming
(known as REB modulations). We provide detailed general equations for the fit
of the REB modulations for the case of eccentric orbits. These equations are
accurate to the photometric precisions achievable by current and forthcoming
instruments and space missions. By using this mathematical apparatus, we find
three close-in {very low-mass companions (two of them in the brown dwarf mass
domain)} orbiting main-sequence stars (KOI-554, KOI-1074, and KOI-3728), and
reject the planetary nature of the transiting objects (thus classifying them as
false positives). In contrast, the detection of the REB modulations and
transit/eclipse signal allows the measurement of their mass and radius that can
provide important constraints for modeling their interiors since just a few
cases of low-mass eclipsing binaries are known. Additionally, these new systems
can help to constrain the similarities in the formation process of the more
massive and close-in planets (hot Jupiters), brown dwarfs, and very low-mass
companions.


title:
Diophantine approximation on subspaces of $\mathbb{R}^n$ and dynamics on
  homogeneous spaces

abstract:
  In recent years, the ergodic theory of group actions on homogeneous spaces
has played a significant role in the metric theory of Diophantine
approximation. We survey some recent developments with special emphasis on
Diophantine properties of affine subspaces and their submanifolds.


title: Effect of fluid inertia on the motion of a collinear swimmer

abstract:
  The swimming of a two-sphere system and of a three-sphere chain in an
incompressible viscous fluid is studied on the basis of simplified equations of
motion which take account of both Stokes friction and added mass effects. The
analysis is based on an explicit expression for the asymptotic periodic
swimming velocity and a corresponding evaluation of the mean rate of
dissipation. The mean swimming velocity of the two-sphere system is found to be
non-vanishing provided that the two spheres are not identical. The swimming of
a comparable chain of three identical spheres is much more efficient.


title: On clustering network-valued data

abstract:
  Community detection, which focuses on clustering nodes or detecting
communities in (mostly) a single network, is a problem of considerable
practical interest and has received a great deal of attention in the research
community. While being able to cluster within a network is important, there are
emerging needs to be able to cluster multiple networks. This is largely
motivated by the routine collection of network data that are generated from
potentially different populations. These networks may or may not have node
correspondence. When node correspondence is present, we cluster networks by
summarizing a network by its graphon estimate, whereas when node correspondence
is not present, we propose a novel solution for clustering such networks by
associating a computationally feasible feature vector to each network based on
trace of powers of the adjacency matrix. We illustrate our methods using both
simulated and real data sets, and theoretical justifications are provided in
terms of consistency.


title: Covering monopole map and higher degree in non commutative geometry

abstract:
  In this paper we develop analysis of the monopole maps over the universal
covering space of a compact four manifold. We induce a property on local
properness of the covering monopole map under the condition of closeness of the
AHS complex. In particular we construct a higher degree of the covering
monopole map when the linearized equation is isomorphic, which induces a
homomorphism between K group of the group C^* algebras. It involves non linear
analysis on the covering space, which is related to L^p cohomology. We also
obtain various Sobolev estimates on the covering spaces.
  As a possible application, we propose an aspherical version of 10/8
inequality, combining with Singer conjecture on L^2 cohomology. It is satisfied
for a large class of four manifolds which includes some complex surfaces of
general type.


title:
Spin-orbit driven Peierls transition and possible exotic
  superconductivity in CsW$_{2}$O$_{6}$

abstract:
  We study \textit{ab initio} a pyrochlore compound, CsW$_{2}$O$_{6}$, which
exhibits a yet unexplained metal-insulator transition. We find that (1) the
reported low-$T$ structure is likely inaccurate and the correct structure has a
twice larger cell; (2) the insulating phase is not of a Mott or dimer-singlet
nature, but a rare example of a 3D Peierls transition, with a simultaneous
condensation of three density waves; (3) spin-orbit interaction plays a crucial
role, forming well-nested bands. The high-$T$ (HT) phase, if stabilized, could
harbor a unique $e_{g}+ie_{g}$ superconducting state that breaks the time
reversal symmetry, but is not chiral. This state was predicted in 1999, but
never observed. We speculate about possible ways to stabilize the HT phase
while keeping the conditions for superconductivity.


title: Clustering with Same-Cluster Queries

abstract:
  We propose a framework for Semi-Supervised Active Clustering framework
(SSAC), where the learner is allowed to interact with a domain expert, asking
whether two given instances belong to the same cluster or not. We study the
query and computational complexity of clustering in this framework. We consider
a setting where the expert conforms to a center-based clustering with a notion
of margin. We show that there is a trade off between computational complexity
and query complexity; We prove that for the case of $k$-means clustering (i.e.,
when the expert conforms to a solution of $k$-means), having access to
relatively few such queries allows efficient solutions to otherwise NP hard
problems.
  In particular, we provide a probabilistic polynomial-time (BPP) algorithm for
clustering in this setting that asks $O\big(k^2\log k + k\log n)$ same-cluster
queries and runs with time complexity $O\big(kn\log n)$ (where $k$ is the
number of clusters and $n$ is the number of instances). The algorithm succeeds
with high probability for data satisfying margin conditions under which,
without queries, we show that the problem is NP hard. We also prove a lower
bound on the number of queries needed to have a computationally efficient
clustering algorithm in this setting.


title:
Observation of a Hidden Hole-Like Band Approaching the Fermi Level in
  K-Doped Iron Selenide Superconductor

abstract:
  One of the ultimate goals of the study of iron-based superconductors is to
identify the common feature that produces the high critical temperature (Tc).
In the early days, based on a weak-coupling viewpoint, the nesting between
hole- and electron-like Fermi surfaces (FSs) leading to the so-called $s\pm$
state was considered to be one such key feature. However, this theory has faced
a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS)
superconductors, in which only electron-like FSs with a nodeless
superconducting gap are observed. Several theories have been proposed, but a
consistent understanding is yet to be achieved. Here we show experimentally
that a hole-like band exists in KxFe2-ySe2, which presumably forms a hole-like
Fermi surface. The present study suggests that AFS can be categorized in the
same group as iron arsenides with both hole- and electron-like FSs present.
This result provides a foundation for a comprehensive understanding of the
superconductivity in iron-based superconductors.


title:
More characterizations of generalized bent function in odd
  characteristic, their dual and the gray image

abstract:
  In this paper, we further investigate properties of generalized bent Boolean
functions from $\Z_{p}^n$ to $\Z_{p^k}$, where $p$ is an odd prime and $k$ is a
positive integer. For various kinds of representations, sufficient and
necessary conditions for bent-ness of such functions are given in terms of
their various kinds of component functions. Furthermore, a subclass of gbent
functions corresponding to relative difference sets, which we call
$\Z_{p^k}$-bent functions, are studied. It turns out that $\Z_{p^k}$-bent
functions correspond to a class of vectorial bent functions, and the property
of being $\Z_{p^k}$-bent is much stronger then the standard bent-ness. The dual
and the generalized Gray image of gbent function are also discussed. In
addition, as a further generalization, we also define and give
characterizations of gbent functions from $\Z_{p^l}^n$ to $\Z_{p^k}$ for a
positive integer $l$ with $l<k$.


title: Structured Convolution Matrices for Energy-efficient Deep learning

abstract:
  We derive a relationship between network representation in energy-efficient
neuromorphic architectures and block Toplitz convolutional matrices. Inspired
by this connection, we develop deep convolutional networks using a family of
structured convolutional matrices and achieve state-of-the-art trade-off
between energy efficiency and classification accuracy for well-known image
recognition tasks. We also put forward a novel method to train binary
convolutional networks by utilising an existing connection between
noisy-rectified linear units and binary activations.


title: On a theorem of Blichfeldt

abstract:
  Let $G$ be a permutation group on $n<\infty$ objects. Let $f(g)$ be the
number of fixed points of $g\in G$, and let $\{f(g):1\ne g\in
G\}=\{f_1,\ldots,f_r\}$. In this expository note we give a character-free proof
of a theorem of Blichfeldt which asserts that the order of $G$ divides
$(n-f_1)\ldots(n-f_r)$. We also discuss the sharpness of this bound.


title: How to manipulate truthful prior-dependent mechanisms?

abstract:
  In the standard formulation of mechanism design, a key assumption is that the
designer has reliable information and technology to determine a prior
distribution on types of the agents. In the meanwhile, as pointed out by the
Wilson's Principle, a mechanism should reply as little as possible on the
accuracy of prior type distribution. In this paper, we put forward a model to
formalize and quantify this statement.
  In our model, each agent has a type distribution. In addition, the agent can
commit to a fake distribution and bids consistently and credibly with respect
to the fake distribution (i.e., plays Bayes equilibrium under the fake
distributions). We study the equilibria of the induced distribution-committing
games in several well-known mechanisms. Our results can be summarized as
follows: (1) the game induced by Myerson's auction under our model is
strategically equivalent to the first price auction under the standard model.
As a consequence, they are revenue-equivalent as well. (2) the second-price
auction yields weakly better revenue than several reserve-based and
virtual-value-based auctions, under our fake distribution model. These results
echo the recent literature on prior-independent mechanism design.


title: Double Poisson extensions

abstract:
  A double Ore extension was introduced by James Zhang and Jun Zhang [26] to
study a class of Artin-Schelter regular algebras. Here we give a definition of
Poisson double extension which may be considered as an analogue of double Ore
extension and show that algebras in a class of double Ore extensions are
deformation quantizations of Poisson double extensions. We also investigate the
modular derivations of Poisson double extensions and the relationship between
Poisson double extensions and iterated Poisson polynomial extensions. Results
are illustrated by examples.


title: Level-set percolation for the Gaussian free field on a transient tree

abstract:
  We investigate level-set percolation of the Gaussian free field on transient
trees, for instance on super-critical Galton-Watson trees conditioned on
non-extinction. Recently developed Dynkin-type isomorphism theorems provide a
comparison with percolation of the vacant set of random interlacements, which
is more tractable in the case of trees. If $h_*$ and $u_*$ denote the
respective (non-negative) critical values of level-set percolation of the
Gaussian free field and of the vacant set of random interlacements, we show
here that $h_* < \sqrt{2u}_*$ in a broad enough set-up, but provide an example
where $0 = h_* = u_*$ occurs. We also obtain some sufficient conditions
ensuring that $h_* > 0$.


title:
Hidden Markov model tracking of continuous gravitational waves from a
  neutron star with wandering spin

abstract:
  Gravitational wave searches for continuous-wave signals from neutron stars
are especially challenging when the star's spin frequency is unknown a priori
from electromagnetic observations and wanders stochastically under the action
of internal (e.g. superfluid or magnetospheric) or external (e.g. accretion)
torques. It is shown that frequency tracking by hidden Markov model (HMM)
methods can be combined with existing maximum likelihood coherent matched
filters like the F-statistic to surmount some of the challenges raised by spin
wandering. Specifically it is found that, for an isolated, biaxial rotor whose
spin frequency walks randomly, HMM tracking of the F-statistic output from
coherent segments with duration T_drift = 10d over a total observation time of
T_obs = 1yr can detect signals with wave strains h0 > 2e-26 at a noise level
characteristic of the Advanced Laser Interferometer Gravitational Wave
Observatory (Advanced LIGO). For a biaxial rotor with randomly walking spin in
a binary orbit, whose orbital period and semi-major axis are known
approximately from electromagnetic observations, HMM tracking of the
Bessel-weighted F-statistic output can detect signals with h0 > 8e-26. An
efficient, recursive, HMM solver based on the Viterbi algorithm is
demonstrated, which requires ~10^3 CPU-hours for a typical, broadband (0.5-kHz)
search for the low-mass X-ray binary Scorpius X-1, including generation of the
relevant F-statistic input. In a "realistic" observational scenario, Viterbi
tracking successfully detects 41 out of 50 synthetic signals without spin
wandering in Stage I of the Scorpius X-1 Mock Data Challenge convened by the
LIGO Scientific Collaboration down to a wave strain of h0 = 1.1e-25, recovering
the frequency with a root-mean-square accuracy of <= 4.3e-3 Hz.


title:
Effect of ferromagnetic exchange field on band-gap and spin-polarization
  of graphene on a TMD substrate

abstract:
  We calculate the electronic band dispersion of graphene monolayer on a two
dimensional transition metal dichalcogenide substrate (GTMD) (viz., XY2 , X =
Mo, W; Y = S, Se) around K and K prime points taking into account the interplay
of the exchange field due to the ferromagnetic impurities and the substrate
induced, sub-lattice-resolved, strongly enhanced intrinsic spin-orbit
couplings(SOC). There are extrinsic Rashba spin-orbit coupling(RSOC) and the
orbital gap related to the transfer of the electronic charge from graphene to
XY2 as well. The former allows for external tuning of the band gap in GTMD and
connects the nearest neighbors with spin-flip. On account of the strong SOC,
the system acts as a quantum spin Hall insulator. We introduce the exchange
field (M) in the Hamiltonian to take into account the deposition of Fe atoms on
the graphene surface. The cavalcade of the perturbations yield particle-hole
symmetric bands with an effective Zeeman field due to the interplay of the
substrate induced interactions with RSOC as the prime player. Our graphical
analysis with extremely low-lying states strongly suggests the following: The
GTMDs like WY2 exhibit band gap narrowing/widening (Moss-Burs-tein(MB)gap
shift)including the spin-polarization inversion(SPI) at finite but low
temperature (T = 1 K) due to the increase in the exchange field (M) at the
Dirac point K. For graphene on MoY2, on the other hand, the occurrence of the
MB-shift and the SPI at higher temperature (T = 10 K) take place as M is
increased at the Dirac point K prime. Finally, there is anti-crossing of
non-parabolic bands with opposite spins around Dirac points. A direct electric
field control of magnetism at the nano-scale is needed here. The magnetic
multi-ferroics, like BiFeO3 (BFO), are useful for this purpose due to the
coupling between the magnetic and electric order parameters.


title:
New forms and thermodynamics of the neutral rotating squashed black hole
  in five-dimensional vacuum Einstein gravity theory

abstract:
  We initiated the program to look for new and simple forms for the
five-dimensional rotating squashed black holes by solving directly the equation
of motion. In a recent paper, the metric ansatz of dimensional reduction along
the fifth spatial dimension was used to obtain a new but rather simple form for
the five-dimensional rotating uncharged black hole solution with squashed
horizons via solving the vacuum Einstein field equations. In this work, we
continue to seek for another new but relatively simple form for the neutral
rotating squashed black hole solution by using a different metric ansatz of
time-like dimensional reduction. We then find its relation to our previous
solution and investigate its thermodynamics by means of the counterterm method.
Compared with the previous results given by the other author, both of our new
metric forms and their associated thermodynamic expressions are very concise
and elegant. Both of two new forms for the neutral rotating squashed black hole
solution presented in this paper can be used as the seed to generate its
charged generalization in D=5 minimal supergravity.


title: Rotating and accelerating black holes with cosmological constant

abstract:
  We propose a new form of the rotating C-metric with cosmological constant,
which generalises the form found by Hong and Teo for the Ricci-flat case. This
solution describes the entire class of spherical black holes undergoing
rotation and acceleration in dS or AdS space-time. The new form allows us to
identify the complete ranges of coordinates and parameters of this solution. We
perform a systematic study of its geometrical and physical properties, and of
the various limiting cases that arise from it.


title:
Anisotropic flow of Pb+Pb $\sqrt{s_{\rm NN}}$ = 5.02 TeV from A
  Multi-Phase Transport Model

abstract:
  Anisotropic flow is an important observable in the study of the Quark-Gluon
Plasma that is expected to be formed in heavy-ion collisions. With a multiphase
transport (AMPT) model we investigate the elliptic($\emph{v}_{2}$),
triangular($\emph{v}_{3}$), and quadrangular($\emph{v}_{4}$) flow of charged
particles in Pb+Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. Then We
compare our flow results with the published ALICE flow results. We found our
AMPT simulated results are consistent with ALICE experimental data.


title:
Testing an Ansatz for the Leading Secular Loop Corrections from Quantum
  Gravity during Inflation

abstract:
  It is widely believed that the leading secular loop corrections from quantum
gravity can be subsumed into a coordinate redefinition. Hence the apparent
infrared logarithm corrections to any quantity would be just the result of
taking the expectation value of the tree order quantity at the transformed
coordinates in the graviton vacuum. We term this the Transformation Ansatz and
we compare its predictions against explicit one loop computations in Maxwell +
Einstein and Dirac + Einstein on de Sitter background. In each case the ansatz
fails.


title:
A theory addressing the quantum measurement problem: collapse occurs
  when the entangling speed reaches a threshold

abstract:
  To resolve the quantum measurement problem, we propose an objective collapse
theory in which both the wavefunction and the process of collapse are regarded
as ontologically objective. The theory, which we call the
entangling-speed-threshold theory, postulates that collapse occurs when the
entangling speed of a system reaches a threshold, and the collapse basis is
determined so as to eliminate the entangling speed and to minimize its
increasing rate. Using this theory, we provide answers to the questions of
where and when collapse occurs, how the collapse basis is determined, what
systems are (in other words, what the actual tensor product structure is), and
what determines the observables. We also explain how deterministic classical
dynamics emerges from indeterministic quantum collapse, explaining the
quantum-to-classical transition. In addition, we show that the theory
guarantees energy conservation to a high accuracy. We apply the theory to a
macroscopic flying body such as a bullet in the air, and derive a satisfactory
collapse basis that is highly localized in both position and momentum,
consistent with our everyday observation. Finally, we suggest an experiment
that can verify the theory.


title: Universal Synchronous Spin Rotators for Electron-Ion Colliders

abstract:
  The paper provides mathematics and physics considerations concerning a
special class of electron spin manipulating structures for future Electron-Ion
Collider (EIC) projects. These structures, which we call Universal Synchronous
Spin Rotators (USSR), consist of a sequence of standard basic spin manipulating
elements or cells built with two solenoids and one bending magnet between them.
When integrated into the ring arcs, USSR structures do not affect the central
particle orbit, and their spin transformation functions can be described by a
linear mathematical model. In spite of being relatively simple, the model
allows one to design spin rotators, which are able to perform spin direction
changes from vertical to longitudinal and vice versa in significant continuous
intervals of the electron energy. This makes USSR especially valuable tools for
EIC nuclear physics experiments.


title: A Holographic Description of Negative Energy States

abstract:
  Using the AdS/CFT duality, we study the expectation value of stress tensor in
$2+1$-dimensional quantum critical theories with a general dynamical scaling
$z$, and explore various constrains on negative energy density for strongly
coupled field theories. The holographic dual theory is the theory of gravity in
3+1-dimensional Lifshitz backgrounds. We adopt a consistent approach to obtain
the boundary stress tensor from bulk construction, which satisfies the trace
Ward identity associated with Lifshitz scaling symmetry. In particular, the
boundary stress tensor, constructed from the gravitational wave deformed
Lifshitz geometry, is found up to second order in gravitational wave
perturbations. {The result} is compared to its counterpart in free {scalar}
field theory at the same order in an expansion of small squeezing parameters.
This allows us to relate the boundary values of gravitational waves to the
squeezing parameters of squeezed vacuum states. We find that, in both cases
with $z=1$, the stress tensor satisfies the averaged null energy condition, and
is consistent with the quantum interest conjecture. Moreover, the negative
lower bound on null-contracted stress tensor, which is averaged over time-like
trajectories along nearly null directions, is obtained. We find a weaker
constraint on the magnitude and duration of negative null energy density in
strongly coupled field theory as compared with the constraint in free
relativistic field theory. The implications are discussed.


title:
Gossip Dual Averaging for Decentralized Optimization of Pairwise
  Functions

abstract:
  In decentralized networks (of sensors, connected objects, etc.), there is an
important need for efficient algorithms to optimize a global cost function, for
instance to learn a global model from the local data collected by each
computing unit. In this paper, we address the problem of decentralized
minimization of pairwise functions of the data points, where these points are
distributed over the nodes of a graph defining the communication topology of
the network. This general problem finds applications in ranking, distance
metric learning and graph inference, among others. We propose new gossip
algorithms based on dual averaging which aims at solving such problems both in
synchronous and asynchronous settings. The proposed framework is flexible
enough to deal with constrained and regularized variants of the optimization
problem. Our theoretical analysis reveals that the proposed algorithms preserve
the convergence rate of centralized dual averaging up to an additive bias term.
We present numerical simulations on Area Under the ROC Curve (AUC) maximization
and metric learning problems which illustrate the practical interest of our
approach.


title:
Bayesian inference for the stochastic identification of elastoplastic
  material parameters: Introduction, misconceptions and insights

abstract:
  We discuss Bayesian inference (BI) for the probabilistic identification of
material parameters. This contribution aims to shed light on the use of BI for
the identification of elastoplastic material parameters. For this purpose a
single spring is considered, for which the stress-strain curves are
artificially created. Besides offering a didactic introduction to BI, this
paper proposes an approach to incorporate statistical errors both in the
measured stresses, and in the measured strains. It is assumed that the
uncertainty is only due to measurement errors and the material is homogeneous.
Furthermore, a number of possible misconceptions on BI are highlighted based on
the purely elastic case.


title: Gaussian heat kernel estimates: from functions to forms

abstract:
  On a complete non-compact Riemannian manifold satisfying the volume doubling
property, we give conditions on the negative part of the Ricci curvature that
ensure that, unless there are harmonic one-forms, the Gaussian heat kernel
upper estimate on functions transfers to one-forms. These conditions do no
entail any constraint on the size of the Ricci curvature, only on its decay at
infinity.


title: Generic-Precision algorithm for DCT-Cordic architectures

abstract:
  In this paper we propose a generic algorithm to calculate the rotation
parameters of CORDIC angles required for the Discrete Cosine Transform
algorithm (DCT). This leads us to increase the precision of calculation meeting
any accuracy.Our contribution is to use this decomposition in CORDIC based DCT
which is appropriate for domains which require high quality and top precision.
We then propose a hardware implementation of the novel transformation, and as
expected, a substantial improvement in PSNR quality is found.


title: Field Theories Without a Holographic Dual

abstract:
  In applying the gauge-gravity duality to the quark-gluon plasma, one models
the plasma using a particular kind of field theory with specified values of the
temperature, magnetic field, and so forth. One then assumes that the bulk, an
asymptotically AdS black hole spacetime with properties chosen to match those
of the boundary field theory, can be embedded in string theory. But this is not
always the case: there are field theories with no bulk dual. The question is
whether these theories might include those used to study the actual plasmas
produced at such facilities as the RHIC experiment or the relevant experiments
at the LHC. We argue that, \emph{provided} that due care is taken to include
the effects of the angular momentum associated with the magnetic fields
experienced by the plasmas produced by peripheral collisions, the existence of
the dual can be established for the RHIC plasmas. In the case of the LHC
plasmas, the situation is much more doubtful.


title: On the number of SQS

abstract:
  A Steiner quadruple system (briefly $SQS(n)$) is a pair $(X,B)$ where $|X|=n$
and $B$ is a collection of 4-element blocks such that every 3-subset of $X$ is
contained in exactly one member of $B$. Hanani \cite{Hanani} proved that the
necessary condition $n\ {\rm mod}\ 6= 2\ {\rm or}\ 4$ for the existence of a
Steiner quadruple systems of order $n$ is also sufficient. Lenz \cite{Lenz}
proved that the logarithm of the number of different $SQS(n)$ is greater than
$cn^3$ where $c>0$ is a constant and $n$ is admissible. We prove that the
logarithm of the number of different $SQS(n)$ is $\Theta(n^3\ln n)$ as
$n\rightarrow\infty$ and $n\ {\rm mod}\ 6= 2\ {\rm or}\ 4$.


title: VIF: Virtual Interactive Fiction (with a twist)

abstract:
  Nowadays computer science can create digital worlds that deeply immerse
users; it can also process in real time brain activity to infer their inner
states. What marvels can we achieve with such technologies? Go back to
displaying text. And unfold a story that follows and molds users as never
before.


title: The linear request problem

abstract:
  We propose a simple approach to a problem introduced by Galatolo and
Pollicott, consisting in perturbing a dynamical system in order for its
absolutely continuous invariant measure to change in a prescribed way. Instead
of using transfer operators, we observe that restricting to an infinitesimal
conjugacy already yields a solution. This allows us to work in any dimension
and dispense from any dynamical hypothesis. In particular, we don't need to
assume hyperbolicity to obtain a solution, although expansion moreover ensures
the existence of an infinite-dimensional space of solutions.


title:
Second-order Structural Transition in Superconductor
  La$_3$Co$_4$Sn$_{13}$

abstract:
  The quasi-skutterudite superconductor La$_3$Co$_4$Sn$_{13}$ undergoes a phase
transition at $T^*=152$ K. By measuring the temperature dependence of heat
capacity, electrical resistivity, and the superlattice reflection intensity
using X-ray, we explore the character of the phase transition at $T^*$. Our
lattice dynamic calculations found imaginary phonon frequencies around the
${\bf M}$ point, when the high temperature structure is used in the
calculations, indicating that the structure is unstable at the zero temperature
limit. The combined experimental and computational results establish that $T^*$
is associated with a second-order structural transition with $\bf{q}$=(0.5,
0.5, 0) (or the ${\bf M}$ point). Further electronic bandstructure calculations
reveal Fermi surface sheets with low curvature segments, which allow us to draw
qualitative comparison with both Sr$_3$Ir$_4$Sn$_{13}$ and
Sr$_3$Rh$_4$Sn$_{13}$ in which similar physics has been discussed recently.


title: On minimal distance between q-ary bent functions

abstract:
  The minimal Hamming distance between distinct $p$-ary bent functions of $2n$
variables is proved to be $p^n$ for any prime $p$. It is shown that the number
of $p$-ary bent functions at the distance $p^n$ from the quadratic bent
function is equal to $p^n(p^{n-1}+1)\cdots(p+1)(p-1)$ as $p>2$.


title: Finite groups with small number of cyclic subgroups

abstract:
  In this note, we study the finite groups with the number of cylic subgroups
no greater than 6.


title:
Role of Hydrogen in the Electronic Properties of CaFeAsH-based
  Superconductors

abstract:
  The electronic and magnetic properties of the new hydride superconductor
CaFeAsH, which superconducts up to 47 K when electron-doped with La, and the
isovalent alloy system CaFeAsH$_{1-x}$F$_x$ are investigated using density
functional based methods. The $\vec Q = (\pi,\pi,0)$ peak of the nesting
function $\xi(\vec q)$ is found to be extremely strong and sharp, and
additional structure in $\xi(\vec q)$ associated with the near-circular Fermi
surfaces (FSs) that may impact low energy excitations is quantified. The
unusual band introduced by H, which shows strong dispersion perpendicular to
the FeAs layers, is shown to be connected to a peculiar van Hove singularity
just below the Fermi level. This band provides a three dimensional electron
ellipsoid Fermi surface not present in other Fe-based superconducting materials
nor in CaFeAsF. Electron doping by 25\% La or Co has minor affect on this
ellipsoid Fermi surface, but suppresses FS nesting strongly, consistent with
the viewpoint that eliminating strong nesting and the associated magnetic order
allows high T$_c$ superconductivity to emerge. Various aspects of the isovalent
alloy system CaFeAsH$_{1-x}$F$_x$ and means of electron doping are discussed in
terms of influence of incipient bands.


title:
Training Design and Two-stage Channel Estimation for Correlated Two-way
  MIMO Relay Systems

abstract:
  This paper addresses the training signal design for the channel estimation in
two-way multiple-input-and-multipleoutput (MIMO) relay systems, where the
channels are correlated. We first derive the backward channel estimator with
the optimal training signal sent by the relay node. Given the estimated
backward channels and the probabilistic knowledge of the estimation error, we
mainly focus on the forward channel estimation and the related training signal
design. We further propose a novel training signal. The design criterion is to
minimize the relaxation of the total mean square error (MSE) of the forward
channel estimators, which is conditioned on the estimated backward channels.
Finally, the numerical results show that the proposed training signal can
improve the MSE performance.


title:
Threshold singularities, dispersion relations and fixed-order
  perturbative calculations

abstract:
  We show how to correctly treat threshold singularities in fixed-order
perturbative calculations of the electron anomalous magnetic moment and
hadronic pair production processes such as top pair production. With respect to
the former, we demonstrate the equivalence of the "non-perturbative", resummed
treatment of the vacuum polarization contribution, whose spectral function
exhibits bound state poles, with the fixed-order calculation by identifying a
threshold localized term in the four-loop spectral function. In general, we
find that a modification of the dispersion relation by threshold subtractions
is required to make fixed-order calculations well-defined and provide the
subtraction term. We then solve the apparent problem of a divergent convolution
of the partonic cross section with the parton luminosity in the computation of
the top pair production cross section starting from the fourth-order
correction. We find that when the computation is performed in the usual way as
an integral of real and virtual corrections over phase space at a given order
in the expansion in the strong coupling, an additional contribution has to be
added at N3LO.


title:
Structural and electrical properties of CdS thin films spin coated on
  glass substrates

abstract:
  CdS samples were synthesized on amorphous glass and conductive glass
substrates at room temperature using spin coating technique and subsequently
annealed at five different temperatures in air for one hour. The speed and time
of spin coating were varied initially to optimize the properties of the
samples. FTIR spectroscopy was used in this experiment to analyze CdS bond
formation variation with annealing temperature. A liquid junction photocell
with KI/I2 electrolyte was prepared to measure the photovoltaic properties.
Photovoltage, photocurrent and corresponding output power were measured in
order to determine the output power.


title:
HST imaging of the dusty filaments and nucleus swirl in NGC4696 at the
  centre of the Centaurus Cluster

abstract:
  Narrow-band HST imaging has resolved the detailed internal structure of the
10 kpc diameter H alpha+[NII] emission line nebulosity in NGC4696, the central
galaxy in the nearby Centaurus cluster, showing that the dusty, molecular,
filaments have a width of about 60pc. Optical morphology and velocity
measurements indicate that the filaments are dragged out by the bubbling action
of the radio source as part of the AGN feedback cycle. Using the drag force we
find that the magnetic field in the filaments is in approximate pressure
equipartition with the hot gas. The filamentary nature of the cold gas
continues inward, swirling around and within the Bondi accretion radius of the
central black hole, revealing the magnetic nature of the gas flows in massive
elliptical galaxies. HST imaging resolves the magnetic, dusty, molecular
filaments at the centre of the Centaurus cluster to a swirl around and within
the Bondi radius.


title: Fusion ignition via a magnetically-assisted fast ignition approach

abstract:
  Significant progress has been made towards laser-driven fusion ignition via
different schemes, including direct and indirect central ignition, fast
ignition, shock ignition, and impact ignition schemes. However, to reach
ignition conditions, there are still various technical and physical challenges
to be solved for all these schemes. Here, our multi-dimensional integrated
simulation shows that the fast-ignition conditions could be achieved when two
2.8 petawatt heating laser pulses counter-propagate along a 3.5 kilotesla
external magnetic field. Within a period of 5 picoseconds, the laser pulses
heat a nuclear fuel to reach the ignition conditions. Furthermore, we present
the parameter windows of lasers and magnetic fields required for ignition for
experimental test.


title:
Comparison of an open-hardware electroencephalography amplifier with
  medical grade device in brain-computer interface applications

abstract:
  Brain-computer interfaces (BCI) are promising communication devices between
humans and machines. BCI based on non-invasive neuroimaging techniques such as
electroencephalography (EEG) have many applications , however the dissemination
of the technology is limited, in part because of the price of the hardware. In
this paper we compare side by side two EEG amplifiers, the consumer grade
OpenBCI and the medical grade g.tec g.USBamp. For this purpose, we employed an
original montage, based on the simultaneous recording of the same set of
electrodes. Two set of recordings were performed. During the first experiment a
simple adapter with a direct connection between the amplifiers and the
electrodes was used. Then, in a second experiment, we attempted to discard any
possible interference that one amplifier could cause to the other by adding
"ideal" diodes to the adapter. Both spectral and temporal features were tested
-- the former with a workload monitoring task, the latter with an visual P300
speller task. Overall, the results suggest that the OpenBCI board -- or a
similar solution based on the Texas Instrument ADS1299 chip -- could be an
effective alternative to traditional EEG devices. Even though a medical grade
equipment still outperforms the OpenBCI, the latter gives very close EEG
readings, resulting in practice in a classification accuracy that may be
suitable for popularizing BCI uses.


title:
Magnetic energy of sc ferromagnetic films with three layers as described
  by third order perturbed Heisenberg Hamiltonian

abstract:
  The solution of third order perturbed Heisenberg Hamiltonian of simple cubic
ferromagnetic ultra-thin films with three layers were found. All the magnetic
energy parameters such as spin exchange interaction, magnetic dipole
interaction, second order magnetic anisotropy, fourth order magnetic
anisotropy, applied magnetic field, demagnetization factor and stress induced
anisotropy were included in the third order perturbed Heisenberg Hamiltonian.
3-D plots of stress induced anisotropy, out of plane magnetic field,
demagnetization factor and spin exchange interaction are presented in this
manuscript. Magnetic easy and hard directions were determined using these 3-D
plots. MATLAB program was employed to solve the equation with seven parameters.


title:
On the Place of Text Data in Lifelogs, and Text Analysis via Semantic
  Facets

abstract:
  Current research in lifelog data has not paid enough attention to analysis of
cognitive activities in comparison to physical activities. We argue that as we
look into the future, wearable devices are going to be cheaper and more
prevalent and textual data will play a more significant role. Data captured by
lifelogging devices will increasingly include speech and text, potentially
useful in analysis of intellectual activities. Analyzing what a person hears,
reads, and sees, we should be able to measure the extent of cognitive activity
devoted to a certain topic or subject by a learner. Test-based lifelog records
can benefit from semantic analysis tools developed for natural language
processing. We show how semantic analysis of such text data can be achieved
through the use of taxonomic subject facets and how these facets might be
useful in quantifying cognitive activity devoted to various topics in a
person's day. We are currently developing a method to automatically create
taxonomic topic vocabularies that can be applied to this detection of
intellectual activity.


title: Using LHC Forward Proton Detectors to Tag Nuclear Debris

abstract:
  The forward proton detectors, already existing at the LHC, are considered in
the context of heavy ion collisions. It is shown that such detectors have the
potential to measure nuclear debris originating from spectator nucleons. The
geometric acceptance for different nuclei is studied, and how it is affected by
the motion of the nucleons in the nucleus and by the experimental conditions. A
possibility of extending the acceptance region is discussed.


title: An Approach for Isolated Testing of Self-Organization Algorithms

abstract:
  We provide a systematic approach for testing self-organization (SO)
algorithms. The main challenges for such a testing domain are the strongly
ramified state space, the possible error masking, the interleaving of
mechanisms, and the oracle problem resulting from the main characteristics of
SO algorithms: their inherent non-deterministic behavior on the one hand, and
their dynamic environment on the other. A key to success for our SO algorithm
testing framework is automation, since it is rarely possible to cope with the
ramified state space manually. The test automation is based on a model-based
testing approach where probabilistic environment profiles are used to derive
test cases that are performed and evaluated on isolated SO algorithms. Besides
isolation, we are able to achieve representative test results with respect to a
specific application. For illustration purposes, we apply the concepts of our
framework to partitioning-based SO algorithms and provide an evaluation in the
context of an existing smart-grid application.


title:
Gravitational Memory Charges of Supertranslation and Superrotation on
  Rindler Horizons

abstract:
  In a Rindler-type coordinate system spanned in a region outside of a black
hole horizon, we have nonvanishing classical holographic charges as soft hairs
on the horizon for stationary black holes. Taking a large black hole mass
limit, the spacetimes with the charges are described by asymptotic Rindler
metrics. We construct a general theory of gravitational holographic charges for
a (1+3)-dimensional linearized gravity field in the Minkowski background with
Rindler horizons. Although matter crossing a Rindler horizon causes horizon
deformation and a time-dependent coordinate shift, that is, gravitational
memory, the supertranslation and superrotation charges on the horizon can be
defined during and after its passage through the horizon. It is generally
proven that holographic states on the horizon cannot store any information
about absorbed perturbative gravitational waves. However, matter crossing the
horizon really excites holographic states. By using gravitational memory
operators, which consist of the holographic charge operators, we suggest a
resolution of the no-cloning paradox of quantum information between matter
falling into the horizon and holographic charges on the horizon from the
viewpoint of the contextuality of quantum measurement.


title: Existence of an invariant form under a linear map

abstract:
  Let $\F$ be a field of characteristic different from $2$ and $\V$ be a vector
space over $\F$. Let $J: \alpha \to \alpha^J$ be a fixed involutory
automorphism on $\F$. In this paper we answer the following question: given an
invertible linear map $T: \V \to \V$, when does the vector space $\V$ admit a
$T$-invariant non-degenerate $J$-hermitian, resp. $J$-skew-hermitian, form?


title:
4D Pyritohedral Symmetry with Quaternions, Related Polytopes and
  Lattices

abstract:
  We describe extension of the pyritohedral symmetry to 4-dimensional Euclidean
space and present the group elements in terms of quaternions. It turns out that
it is a maximal subgroup of both the rank-4 Coxeter groups W(F4) and W(H4)
implying that it is a group relevant to the crystallography as well as
quasicrystallographic structures in 4-dimensions. First we review the
pyritohedral symmetry in 3 dimensional Euclidean space which is a maximal
subgroup both in the Coxeter-Weyl groups W(B3)=Aut(D3) and W(H3). The related
polyhedra in 3-dimensions are the two dual polyhedra pseudoicosahedron-
pyritohedron and the pseudo icosidodecahedron. In quaternionic representations
it finds a natural extension to the 4-dimensions.The related polytopes turn out
to be the pseudo snub 24-cell and its dual polytope expressed in terms of a
parameter x leading to snub 24-cell and its dual in the limit where the
parameter x takes the golden ratio. It turns out that the relevant lattice is
the root lattice of W(D4).


title:
One-Port Direct/Reverse Method for Characterizing VNA Calibration
  Standards

abstract:
  This paper introduces a one-port method for estimating model parameters of
VNA calibration standards. The method involves measuring the standards through
an asymmetrical passive network connected in direct mode and then in reverse
mode, and using these measurements to compute the S-parameters of the network.
The free parameters of the calibration standards are estimated by minimizing a
figure of merit based on the expected equality of the S-parameters of the
network when used in direct and reverse modes. The capabilities of the method
are demonstrated through simulations, and real measurements are used to
estimate the actual offset delay of a 50-$\mathbf{\Omega}$ calibration load
that is assigned zero delay by the manufacturer. The estimated delay is $38.8$
ps with a $1\sigma$ uncertainty of $2.1$ ps for this particular load. This
result is verified through measurements of a terminated airline. The
measurements agree better with theoretical models of the airline when the
reference plane is calibrated using the new estimate for the load delay.


title: Learning Language Games through Interaction

abstract:
  We introduce a new language learning setting relevant to building adaptive
natural language interfaces. It is inspired by Wittgenstein's language games: a
human wishes to accomplish some task (e.g., achieving a certain configuration
of blocks), but can only communicate with a computer, who performs the actual
actions (e.g., removing all red blocks). The computer initially knows nothing
about language and therefore must learn it from scratch through interaction,
while the human adapts to the computer's capabilities. We created a game in a
blocks world and collected interactions from 100 people playing it. First, we
analyze the humans' strategies, showing that using compositionality and
avoiding synonyms correlates positively with task performance. Second, we
compare computer strategies, showing how to quickly learn a semantic parsing
model from scratch, and that modeling pragmatics further accelerates learning
for successful players.


title: Multiple-Play Bandits in the Position-Based Model

abstract:
  Sequentially learning to place items in multi-position displays or lists is a
task that can be cast into the multiple-play semi-bandit setting. However, a
major concern in this context is when the system cannot decide whether the user
feedback for each item is actually exploitable. Indeed, much of the content may
have been simply ignored by the user. The present work proposes to exploit
available information regarding the display position bias under the so-called
Position-based click model (PBM). We first discuss how this model differs from
the Cascade model and its variants considered in several recent works on
multiple-play bandits. We then provide a novel regret lower bound for this
model as well as computationally efficient algorithms that display good
empirical and theoretical performance.


title:
First Passage percolation on a hyperbolic graph admits bi-infinite
  geodesics

abstract:
  Given an infinite connected graph, a way to randomly perturb its metric is to
assign random i.i.d. lengths to the edges. An open question attributed to
Furstenberg is whether there exists a two-sided infinite geodesic in first
passage percolation on Z^2, and more generally on Z^n for n>1. Although the
answer is generally conjectured to be negative, we give a positive answer for
graphs satisfying some negative curvature assumption. Assuming only strict
positivity and finite expectation of the random lengths, we prove that if a
graph X has bounded degree and contains a Morse geodesic (e.g. is
non-elementary Gromov hyperbolic), then almost surely, there exists a
bi-infinite geodesic in first passage percolation on X.


title: Centralizer's applications to the inverse along an element

abstract:
  In this paper, we first prove that the absorption law for one-sided inverses
along an element holds, deriving the absorption law for the inverse along an
element. We then apply this result to obtain the absorption law for the inverse
along different elements. Also, the reverse order law and the existence
criterion for the inverse along an element are given by centralizers in a ring.
Finally, we characterize the Moore-Penrose inverse by one-sided invertibilities
in a ring with involution.


title:
Optimal Motion of Flexible Objects with Oscillations Elimination at the
  Final Point

abstract:
  In this article, a theoretical justification of one type of skew-symmetric
optimal translational motion (moving in the minimal acceptable time) of a
flexible object carried by a robot from its initial to its final position of
absolute quiescence with the exception of the oscillations at the end of the
motion is presented. The Hamilton-Ostrogradsky principle is used as a criterion
for searching an optimal control. The data of experimental verification of the
control are presented using the Orthoglide robot for translational motions and
several masses were attached to a flexible beam.