title: On Kato-Ponce and fractional Leibniz

abstract:
  We show that in the Kato-Ponce inequality $\|J^s(fg)-fJ^s g\|_p \lesssim \|
\partial f \|_{\infty} \| J^{s-1} g \|_p + \| J^s f \|_p \|g\|_{\infty}$, the
$J^s f$ term on the RHS can be replaced by $J^{s-1} \partial f$. This solves a
question raised in Kato-Ponce \cite{KP88}. We propose and prove a new
fractional Leibniz rule for $D^s=(-\Delta)^{s/2}$ and similar operators,
generalizing the Kenig-Ponce-Vega estimate \cite{KPV93} to all $s>0$. We also
prove a family of generalized and refined Kato-Ponce type inequalities which
include many commutator estimates as special cases. To showcase the sharpness
of the estimates at various endpoint cases, we construct several
counterexamples. In particular, we show that in the original Kato-Ponce
inequality, the $L^{\infty}$-norm on the RHS cannot be replaced by the weaker
BMO norm. Some divergence-free counterexamples are also included.


title:
Effects of magnetic and kinetic helicities on the growth of magnetic
  fields in laminar and turbulent flows by helical-Fourier decomposition

abstract:
  We present a numerical and analytical study of incompressible homogeneous
conducting fluids using a helical Fourier representation. We analytically study
both small- and large-scale dynamo properties, as well as the inverse cascade
of magnetic helicity, in the most general minimal subset of interacting
velocity and magnetic fields on a closed Fourier triad. We mainly focus on the
dependency of magnetic field growth as a function of the distribution of
kinetic and magnetic helicities among the three interacting wavenumbers. By
combining direct numerical simulations of the full magnetohydrodynamics
equations with the helical Fourier decomposition we numerically confirm that in
the kinematic dynamo regime the system develops a large-scale magnetic helicity
with opposite sign compared to the small-scale kinetic helicity, a sort of
triad-by-triad $\alpha$-effect in Fourier space. Concerning the small-scale
perturbations, we predict theoretically and confirm numerically that the
largest instability is achieved for the magnetic component with the same
helicity of the flow, in agreement with the Stretch-Twist-Fold mechanism. Vice
versa, in presence of a Lorentz feedback on the velocity, we find that the
inverse cascade of magnetic helicity is mostly local if magnetic and kinetic
helicities have opposite sign, while it is more nonlocal and more intense if
they have the same sign, as predicted by the analytical approach. Our
analytical and numerical results further demonstrate the potential of the
helical Fourier decomposition to elucidate the entangled dynamics of magnetic
and kinetic helicities both in fully developed turbulence and in laminar flows.

categories: physics.flu-dyn astro-ph.EP astro-ph.SR nlin.CD


title: Pattern-Avoiding Polytopes

abstract:
  Two well-known polytopes whose vertices are indexed by permutations in the
symmetric group $\mathfrak{S}_n$ are the permutohedron $P_n$ and the Birkhoff
polytope $B_n$. We consider polytopes $P_n(\Pi)$ and $B_n(\Pi)$, whose vertices
correspond to the permutations in $\mathfrak{S}_n$ avoiding a set of patterns
$\Pi$. For various choices of $\Pi$, we explore the Ehrhart polynomials and
$h^*$-vectors of these polytopes as well as other aspects of their
combinatorial structure.
  For $P_n(\Pi)$, we consider all subsets $\Pi \subseteq \mathfrak{S}_3$ and
are able to provide results in most cases. To illustrate, $P_n(123,132)$ is a
Pitman-Stanley polytope, the number of interior lattice points in
$P_n(132,312)$ is a derangement number, and the normalized volume of
$P_n(123,231,312)$ is the number of trees on $n$ vertices.
  The polytopes $B_n(\Pi)$ seem much more difficult to analyze, so we focus on
four particular choices of $\Pi$. First we show that the $B_n(231,321)$ is
exactly the Chan-Robbins-Yuen polytope. Next we prove that for any $\Pi$
containing $\{123,312\}$ we have $h^*(B_n(\Pi))=1$. Finally, we study
$B_n(132,312)$ and $\widetilde{B}_n(123)$, where the tilde indicates that we
choose vertices corresponding to alternating permutations avoiding the pattern
$123$. In both cases we use order complexes of posets and techniques from toric
algebra to construct regular, unimodular triangulations of the polytopes. The
posets involved turn out to be isomorphic to the lattices of Young diagrams
contained in a certain shape, and this permits us to give an exact expression
for the normalized volumes of the corresponding polytopes via the hook formula.
Finally, Stanley's theory of $(P,\omega)$-partitions allows us to show that
their $h^*$-vectors are symmetric and unimodal.
  Various questions and conjectures are presented throughout.


title:
Combinatorial aspects of the linkage principle for general linear
  supergroups

abstract:
  Let $G=GL(m|n)$ be a general linear supergroup and $G_{ev}$ be its even
subsupergroup isomorphic to $GL(m)\times GL(n)$. In this paper we use the
explicit description of $G_{ev}$-primitive vectors in the costandard
supermodule $\nabla(\lambda)$, the largest polynomial $G$-subsupermodule of the
induced supermodule $H^0_G(\lambda)$, for $(m|n)$-hook partition $\lambda$, and
a properties of certain morphisms $\psi_k$ to derive results related to the odd
linkage for $G$ over a field $F$ of characteristic different from $2$.


title: Optimal Cloning of Quantum States with a Fixed Failure Rate

abstract:
  Perfect cloning of a known set of states with arbitrary prior probabilities
is possible if we allow the cloner to sometimes fail completely. In the optimal
case the probability of failure is at its minimum allowed by the laws of
quantum mechanics. Here we show that it is possible to lower the failure rate
below that of the perfect probabilistic cloner but the price to pay is that the
clones are not perfect; the global fidelity is less than one. We determine the
optimal fidelity of a cloner with a Fixed Failure Rate (FFR cloner) in the case
of a pair of known states. Optimality is shown to be attainable by a
measure-and-prepare protocol in the limit of infinitely many clones. The
optimal protocol consists of discrimination with a fixed rate of inconclusive
outcome followed by preparation of the appropriate clones. The convergence
shows a symmetry-breaking second-order phase transition in the fidelity of the
approximate infinite clones.


title: Late veneer and late accretion to the terrestrial planets

abstract:
  It is generally accepted that silicate-metal (`rocky') planet formation
relies on coagulation from a mixture of sub-Mars sized planetary embryos and
(smaller) planetesimals that dynamically emerge from the evolving circum-solar
disc in the first few million years of our Solar System. Once the planets have,
for the most part, assembled after a giant impact phase, they continue to be
bombarded by a multitude of planetesimals left over from accretion. Here we
place limits on the mass and evolution of these planetesimals based on
constraints from the highly siderophile element (HSE) budget of the Moon.
Outcomes from a combination of N-body and Monte Carlo simulations of planet
formation lead us to four key conclusions about the nature of this early epoch.
First, matching the terrestrial to lunar HSE ratio requires either that the
late veneer on Earth consisted of a single lunar-size impactor striking the
Earth before 4.45 Ga, or that it originated from the impact that created the
Moon. An added complication is that analysis of lunar samples indicates the
Moon does not preserve convincing evidence for a late veneer like Earth.
Second, the expected chondritic veneer component on Mars is 0.06 weight
percent. Third, the flux of terrestrial impactors must have been low (
<=10^(-6) M_earth/Myr) to avoid wholesale melting of Earth's crust after
4.4~Ga, and to simultaneously match the number of observed lunar basins. This
conclusion leads to an Hadean eon which is more clement than assumed
previously. Last, after the terrestrial planets had fully formed, the mass in
remnant planetesimals was ~10^(-3) M_earth, lower by at least an order of
magnitude than most previous models suggest. Our dynamically and geochemically
self-consistent scenario requires that future N-body simulations of rocky
planet formation either directly incorporate collisional grinding or rely on
pebble accretion.


title: Nonmaximal neutrino mixing at NO$\nu$A from nonstandard interactions

abstract:
  Muon neutrino disappearance measurements at NO$\nu$A suggest that maximal
$\theta_{23}$ is excluded at the 2.6$\sigma$ CL. This is in mild tension with
T2K data which prefer maximal mixing. Considering that NO$\nu$A has a much
longer baseline than T2K, we point out that the apparent departure from maximal
mixing in NO$\nu$A may be a consequence of nonstandard neutrino propagation in
matter.


title: Lepton flavor violation in an extended MSSM

abstract:
  In this work we explore a lepton flavor violation effect induced at one loop
for a flavor structure in an extended minimal standard supersymmetric model,
considering an ansatz for the trilinear term. In particular we find a finite
expression which will show the impact of this phenomena in the $h\to \mu \tau$
decay, produced by a mixing in the trilinear coupling of the soft
supersymmetric Lagrangian.


title:
The more you test, the more you find: Smallest P-values become
  increasingly enriched with real findings as more tests are conducted

abstract:
  Increasing accessibility of data to researchers makes it possible to conduct
massive amounts of statistical testing. Rather than follow a carefully crafted
set of scientific hypotheses with statistical analysis, researchers can now
test many possible relations and let P-values or other statistical summaries
generate hypotheses for them. Genetic epidemiology field is an illustrative
case in this paradigm shift. Driven by technological advances, testing a
handful of genetic variants in relation to a health outcome has been abandoned
in favor of agnostic screening of the entire genome, followed by selection of
top hits, e.g., by selection of genetic variants with the smallest association
P-values. At the same time, nearly total lack of replication of claimed
associations that has been shaming the field turned to a flow of reports whose
findings have been robustly replicating. Researchers may have adopted better
statistical practices by learning from past failures, but we suggest that a
steep increase in the amount of statistical testing itself is an important
factor. Regardless of whether statistical significance has been reached, an
increased number of tested hypotheses leads to enrichment of smallest P-values
with genuine associations. In this study, we quantify how the expected
proportion of genuine signals (EPGS) among top hits changes with an increasing
number of tests. When the rate of occurrence of genuine signals does not
decrease too sharply to zero as more tests are performed, the smallest P-values
are increasingly more likely to represent genuine associations in studies with
more tests.


title: Bounded degree and planar spectra

abstract:
  The finite spectrum of a first-order sentence is the set of positive integers
that are the sizes of its models. The class of finite spectra is known to be
the same as the complexity class NE. We consider the spectra obtained by
limiting models to be either planar (in the graph-theoretic sense) or by
bounding the degree of elements. We show that the class of such spectra is
still surprisingly rich by establishing that significant fragments of NE are
included among them. At the same time, we establish non-trivial upper bounds
showing that not all sets in NE are obtained as planar or bounded-degree
spectra.


title: Brain Network Architecture: Implications for Human Learning

abstract:
  Human learning is a complex phenomenon that requires adaptive processes
across a range of temporal and spacial scales. While our understanding of those
processes at single scales has increased exponentially over the last few years,
a mechanistic understanding of the entire phenomenon has remained elusive. We
propose that progress has been stymied by the lack of a quantitative framework
that can account for the full range of neurophysiological and behavioral
dynamics both across scales in the systems and also across different types of
learning. We posit that network neuroscience offers promise in meeting this
challenge. Built on the mathematical fields of complex systems science and
graph theory, network neuroscience embraces the interconnected and hierarchical
nature of human learning, offering insights into the emergent properties of
adaptability. In this review, we discuss the utility of network neuroscience as
a tool to build a quantitative framework in which to study human learning,
which seeks to explain the full chain of events in the brain from sensory input
to motor output, being both biologically plausible and able to make predictions
about how an intervention at a single level of the chain may cause alterations
in another level of the chain. We close by laying out important remaining
challenges in network neuroscience in explicitly bridging spatial scales at
which neurophysiological processes occur, and underscore the utility of such a
quantitative framework for education and therapy.


title: OAM beams from incomplete computer generated holograms

abstract:
  We show that optical beams with orbital angular momentum (OAM) can be
generated even with incomplete computer generated holograms (CGH). These
holograms are made such that random portions of it do not contain any
information. We observe that although the beams produced with these holograms
are less intense, these beams maintain their shape and that their topological
charges are not affected. Furthermore, we show that superposition of two or
more beams can be created using separate incomplete CGHs interspersed together.
Our result is significant especially since most method to generate beams with
OAM for various applications rely on pixelated devices or optical elements with
imperfections.


title: Multiqubit Spectroscopy of Gaussian Quantum Noise

abstract:
  We introduce multi-pulse quantum noise spectroscopy protocols for spectral
estimation of the noise affecting multiple qubits coupled to Gaussian dephasing
environments including both classical and quantum sources. Our protocols are
capable of reconstructing all the noise auto- and cross-correlation spectra
entering the multiqubit dynamics. We argue that this capability is crucial not
only for metrological purposes, as it provides access to the asymmetric spectra
associated with non-classical environments, but ultimately for achieving
quantum fault-tolerance, as it enables the characterization of bath correlation
functions. Our result relies on (i) an exact analytic solution for the reduced
multiqubit dynamics that holds in the presence of an arbitrary Gaussian
environment and dephasing-preserving control; (ii) the use of specific timing
symmetries in the control, which allow for a frequency comb to be engineered
for all filter functions of interest, and for the spectra to be related to
experimentally accessible qubit observables. We show that quantum spectra have
distinctive dynamical signatures, which we explore in two paradigmatic
open-system models describing spin and charge qubits coupled to bosonic
environments. Complete multiqubit noise spectroscopy is demonstrated
numerically in a realistic setting consisting of two-exciton qubits coupled to
a phonon bath. The estimated spectra allow us to accurately predict the exciton
dynamics as well as extract the temperature and spectral density of the quantum
environment.


title: Local Hubble Expansion: Current State of the Problem

abstract:
  We present a brief qualitative overview of the current state of the problem
of Hubble expansion at the sufficiently small scales (e.g., in planetary
systems or local intergalactic volume). The crucial drawbacks of the available
theoretical treatments are emphasized, and the possible ways to avoid them are
outlined. Attention is drawn to a number of observable astronomical phenomena
that could be naturally explained by the local Hubble expansion.

categories: gr-qc astro-ph.CO astro-ph.EP physics.space-ph


title: Tailoring the energy distribution and loss of 2D plasmons

abstract:
  The ability to tailor the energy distribution of plasmons at the nanoscale
has many applications in nanophotonics, such as designing plasmon lasers,
spasers, and quantum emitters. To this end, we analytically study the energy
distribution and the proper field quantization of 2D plasmons with specific
examples for graphene plasmons. We find that the portion of the plasmon energy
contained inside graphene (energy confinement factor) can exceed 50%, despite
graphene being infinitely thin. In fact, this very high energy confinement can
make it challenging to tailor the energy distribution of graphene plasmons just
by modifying the surrounding dielectric environment or the geometry, such as
changing the separation distance between two coupled graphene layers. However,
by adopting concepts of parity-time symmetry breaking, we show that tuning the
loss in one of the two coupled graphene layers can simultaneously tailor the
energy confinement factor and propagation characteristics, causing the
phenomenon of loss-induced plasmonic transparency.


title: MC^2: A Two-Phase Algorithm for Leveraged Matrix Completion

abstract:
  Leverage scores, loosely speaking, reflect the importance of the rows and
columns of a matrix. Ideally, given the leverage scores of a rank-$r$ matrix
$M\in\mathbb{R}^{n\times n}$, that matrix can be reliably completed from just
$O(rn\log^{2}n)$ samples if the samples are chosen randomly from a nonuniform
distribution induced by the leverage scores. In practice, however, the leverage
scores are often unknown a priori. As such, the sample complexity in uniform
matrix completion---using uniform random sampling---increases to
$O(\eta(M)\cdot rn\log^{2}n)$, where $\eta(M)$ is the largest leverage score of
$M$. In this paper, we propose a two-phase algorithm called MC$^2$ for matrix
completion: in the first phase, the leverage scores are estimated based on
uniform random samples, and then in the second phase the matrix is resampled
nonuniformly based on the estimated leverage scores and then completed. For
well-conditioned matrices, the total sample complexity of MC$^2$ is no worse
than uniform matrix completion, and for certain classes of well-conditioned
matrices---namely, reasonably coherent matrices whose leverage scores exhibit
mild decay---MC$^2$ requires substantially fewer samples. Numerical simulations
suggest that the algorithm outperforms uniform matrix completion in a broad
class of matrices, and in particular, is much less sensitive to the condition
number than our theory currently requires.


title:
Effect of stretching-induced changes in hydrodynamic screening on
  coil-stretch hysteresis of unentangled polymer solutions

abstract:
  Extensional rheometry and Brownian Dynamics simulations of flexible polymer
solutions confirm predictions based on blob concepts that coil--stretch
hysteresis in extensional flows increases with concentration, reaching a
maximum at the critical overlap concentration $c^\ast$ before progressively
vanishing in the semidilute regime. These observations demonstrate that chain
stretching strengthens intermolecular hydrodynamic screening in dilute
solutions, but weakens it in semidilute solutions. Flow can thus strongly
modify the concentration dependence of viscoelastic properties of polymer
solutions.


title:
Data Detection in Large Multi-Antenna Wireless Systems via Approximate
  Semidefinite Relaxation

abstract:
  Practical data detectors for future wireless systems with hundreds of
antennas at the base station must achieve high throughput and low error rate at
low complexity. Since the complexity of maximum-likelihood (ML) data detection
is prohibitive for such large wireless systems, approximate methods are
necessary. In this paper, we propose a novel data detection algorithm referred
to as Triangular Approximate SEmidefinite Relaxation (TASER), which is suitable
for two application scenarios: (i) coherent data detection in large multi-user
multiple-input multiple-output (MU-MIMO) wireless systems and (ii) joint
channel estimation and data detection in large single-input multiple-output
(SIMO) wireless systems. For both scenarios, we show that TASER achieves
near-ML error-rate performance at low complexity by relaxing the associated
ML-detection problems into a semidefinite program, which we solve approximately
using a preconditioned forward-backward splitting procedure. Since the
resulting problem is non-convex, we provide convergence guarantees for our
algorithm. To demonstrate the efficacy of TASER in practice, we design a
systolic architecture that enables our algorithm to achieve high throughput at
low hardware complexity, and we develop reference field-programmable gate array
(FPGA) and application-specific integrated circuit (ASIC) designs for various
antenna configurations.


title: Rogue Waves in Ultracold Bosonic Seas

abstract:
  In this work, we numerically consider the initial value problem for nonlinear
Schr\"odinger (NLS) type models arising in the physics of ultracold boson
gases, with generic Gaussian wavepacket initial data. The corresponding
Gaussian's width and, wherever relevant also its amplitude, serve as control
parameters. First we explore the one-dimensional, standard NLS equation with
general power law nonlinearity, in which large amplitude excitations
reminiscent of Peregrine solitons or regular solitons appear to form, as the
width of the relevant Gaussian is varied. Furthermore, the variation of the
nonlinearity exponent aims at a first glimpse of the interplay between rogue or
soliton formation and collapse features. The robustness of the main features to
noise in the initial data is also confirmed. To better connect our study with
the physics of atomic condensates, and explore the role of dimensionality
effects, we also consider the nonpolynomial Schr\"odinger equation (NPSE), as
well as the full three-dimensional NLS equation, and examine the degree to
which relevant considerations generalize.


title:
Differential relations for the largest root distribution of complex
  non-central Wishart matrices

abstract:
  A holonomic system for the probability density function of the largest
eigenvalue of a non-central complex Wishart distribution with identity
covariance matrix is derived. Furthermore a new determinantal formula for the
probability density function is derived (for m=2,3) or conjectured.


title:
Galaxy And Mass Assembly (GAMA): The absence of stellar mass segregation
  in galaxy groups and consistent predictions from GALFORM and EAGLE
  simulations

abstract:
  We investigate the contentious issue of the presence, or lack thereof, of
satellites mass segregation in galaxy groups using the Galaxy And Mass Assembly
(GAMA) survey, the GALFORM semi-analytic and the EAGLE cosmological
hydrodynamical simulation catalogues of galaxy groups. We select groups with
halo mass $12 \leqslant \log(M_{\text{halo}}/h^{-1}M_\odot) <14.5$ and redshift
$z \leqslant 0.32$ and probe the radial distribution of stellar mass out to
twice the group virial radius. All the samples are carefully constructed to be
complete in stellar mass at each redshift range and efforts are made to
regularise the analysis for all the data. Our study shows negligible mass
segregation in galaxy group environments with absolute gradients of
$\lesssim0.08$ dex and also shows a lack of any redshift evolution. Moreover,
we find that our results at least for the GAMA data are robust to different
halo mass and group centre estimates. Furthermore, the EAGLE data allows us to
probe much fainter luminosities ($r$-band magnitude of 22) as well as
investigate the three-dimensional spatial distribution with intrinsic halo
properties, beyond what the current observational data can offer. In both cases
we find that the fainter EAGLE data show a very mild spatial mass segregation
at $z \leqslant 0.22$, which is again not apparent at higher redshift.
Interestingly, our results are in contrast to some earlier findings using the
Sloan Digital Sky Survey. We investigate the source of the disagreement and
suggest that subtle differences between the group finding algorithms could be
the root cause.


title: Event-by-event generation of vorticity in heavy-ion collisions

abstract:
  In a noncentral heavy-ion collision, the two colliding nuclei have finite
angular momentum in the direction perpendicular to the reaction plane. After
the collision, a fraction of the total angular momentum is retained in the
produced hot quark-gluon matter and is manifested in the form of fluid shear.
Such fluid shear creates finite flow vorticity. We study some features of such
generated vorticity, including its strength, beam energy dependence, centrality
dependence, and spatial distribution.


title: Probing nuclear bubble structure via neutron star asteroseismology

abstract:
  We consider torsional oscillations that are trapped in a layer of
spherical-hole (bubble) nuclear structure, which is expected to occur in the
deepest region of the inner crust of a neutron star. Because this layer
intervenes between the phase of slab nuclei and the outer core of uniform
nuclear matter, torsional oscillations in the bubble phase can be excited
separately from usual crustal torsional oscillations. We find from eigenmode
analyses for various models of the equation of state of uniform nuclear matter
that the fundamental frequencies of such oscillations are almost independent of
the incompressibility of symmetric nuclear matter, but strongly depend on the
slope parameter of the nuclear symmetry energy $L$. Although the frequencies
are also sensitive to the entrainment effect, i.e., what portion of nucleons
outside bubbles contribute to the oscillations, by having such a portion fixed,
we can successfully fit the calculated fundamental frequencies of torsional
oscillations in the bubble phase inside a star of specific mass and radius as a
function of $L$. By comparing the resultant fitting formula to the frequencies
of quasi-periodic oscillations (QPOs) observed from the soft-gamma repeaters,
we find that each of the observed low-frequency QPOs can be identified either
as a torsional oscillation in the bubble phase or as a usual crustal
oscillation, given generally accepted values of $L$ for all the stellar models
considered here.


title: Nonlinearity In A Crosslinked Polyelectric Polypeptide

abstract:
  Youngs modulus of soft solids composed of crosslinked synthetic polypeptides
has been determined under different conditions. Co-poly-(L-glutamic acid$_4$,
L-tyrosine$_1$) [PLEY (4:1)] was crosslinked with poly-L-lysine (PLK) and
1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Elasticity
was assessed by subjecting samples to a compressive strain. Cross-linked
material at high relative humidity, RH 75-85%, exhibited non-linear elasticity.
Stress-strain response was approximately linear at low strain but nonlinear
above a threshold strain. Analysis of the secant modulus revealed apparent
softening of samples at low strain and hardening at high strain, as in
biological soft tissues. Fitting stress-strain data with a neo-Hookean model
yielded approximately 40 $\le E \le$ 300 kPa at high RH. Viscoelasticity was
nonlinear at low RH. The average viscosity-driven relaxation time was 13 min at
high strain and 6 min at low strain. Analysis of the derivative of the secant
modulus for non-linear elastic materials revealed a transient response up to a
strain of $\varepsilon \approx$ 0.18-0.20. Above this range, oscillations
tended to zero. Non-linear viscoelastic materials showed lower-amplitude
oscillations than samples at high RH up to $\varepsilon \approx$ 0.06 and
strong damping thereafter. The data suggest that it will be possible to
engineer mechanical properties of polypeptide materials.


abstract:
  We prove existence, multiplicity, and bifurcation results for $p$-Laplacian
problems involving critical Hardy-Sobolev exponents. Our results are mainly for
the case $\lambda \ge \lambda_1$ and extend results in the literature for $0 <
\lambda < \lambda_1$. In the absence of a direct sum decomposition, we use
critical point theorems based on a cohomological index and a related
pseudo-index.


title: A Boosting Method to Face Image Super-resolution

abstract:
  Recently sparse representation has gained great success in face image
super-resolution. The conventional sparsity-based methods enforce sparse coding
on face image patches and the representation fidelity is measured by
$\ell_{2}$-norm. Such a sparse coding model regularizes all facial patches
equally, which however ignores distinct natures of different facial patches for
image reconstruction. In this paper, we propose a new weighted-patch
super-resolution method based on AdaBoost. Specifically, in each iteration of
the AdaBoost operation, each facial patch is weighted automatically according
to the performance of the model on it, so as to highlight those patches that
are more critical for improving the reconstruction power in next step. In this
way, through the AdaBoost training procedure, we can focus more on the patches
(face regions) with richer information. Various experimental results on
standard face database show that our proposed method outperforms
state-of-the-art methods in terms of both objective metrics and visual quality.


title: The Belle II experiment: fundamental physics at the flavor frontier

abstract:
  After the major success of B-factories to establish the CKM mechanism and its
proven potential to search for new physics, the Belle II experiment will
continue exploring the physics at the flavor frontier over the next years.
Belle II will collect 50 times more data than its predecessor, Belle, and allow
for various precision measurements and searches of rare decays and particles.
This paper introduces the B-factory concept and the flavor frontier approach to
search for new physics. It then describes the SuperKEKB accelerator and the
Belle II detector, as well as some of the physics that will be analyzed in
Belle II, concluding with the experiment status and schedule.


title:
Exact and efficient simulation of tail probabilities of heavy-tailed
  infinite series

abstract:
  We develop an efficient simulation algorithm for computing the tail
probabilities of the infinite series $S = \sum_{n \geq 1} a_n X_n$ when random
variables $X_n$ are heavy-tailed. As $S$ is the sum of infinitely many random
variables, any simulation algorithm that stops after simulating only fixed,
finitely many random variables is likely to introduce a bias. We overcome this
challenge by rewriting the tail probability of interest as a sum of a random
number of telescoping terms, and subsequently developing conditional Monte
Carlo based low variance simulation estimators for each telescoping term. The
resulting algorithm is proved to result in estimators that a) have no bias, and
b) require only a fixed, finite number of replications irrespective of how rare
the tail probability of interest is. Thus, by combining a traditional variance
reduction technique such as conditional Monte Carlo with more recent use of
auxiliary randomization to remove bias in a multi-level type representation, we
develop an efficient and unbiased simulation algorithm for tail probabilities
of $S$. These have many applications including in analysis of financial
time-series and stochastic recurrence equations arising in models in actuarial
risk and population biology.


title: Review on Microscopic Pedestrian Simulation Model

abstract:
  Microscopic Pedestrian Simulation Model is computer simulation model of
pedestrian movement where every pedestrian in the model is treated as
individual. Most of pedestrian researches have been done on macroscopic level,
which does not consider the interaction between pedestrians and does not well
suited for prediction of pedestrian flow performance in pedestrian areas or
building with some objects that reduce the effective width of it. In the other
hand, microscopic level has more general usage and considers detail of the
design. Tough the analytical model for microscopic pedestrian model is existed
exist, the numerical solution of the model is very difficult and simulation is
favorable. The model has practical application of Evacuation from building,
Design of pedestrian area, and Experimental & Optimization Design Tool. In
general, Microscopic Pedestrian Simulation Model consist of two terms, that
make the pedestrian moving toward the destination and make repulsive effect
toward other pedestrian or obstacles.


title:
Performance of ternary double circulant, double twistulant, and
  self-dual codes

abstract:
  We study the performance of ternary isodual codes which are not self-dual and
ternary self-dual codes, as measured by the decoding error probability in
bounded distance decoding. We compare the performance of ternary double
circulant and double twistulant codes which are not self-dual with ternary
extremal self-dual codes. We also investigate the performance of ternary
self-dual codes having large minimum weights.


title:
Tracking System to Automate Data Collection of Microscopic Pedestrian
  Traffic Flow

abstract:
  To deal with many pedestrian data, automatic data collection is needed. This
paper describes how to automate the microscopic pedestrian flow data collection
from video files. The study is restricted only to pedestrians without
considering vehicular - pedestrian interaction. Pedestrian tracking system
consists of three sub-systems, which calculates the image processing, object
tracking and traffic flow variables. The system receives input of stacks of
images and parameters. The first sub-system performs Image Processing analysis
while the second sub-system carries out the tracking of pedestrians by matching
the features and tracing the pedestrian numbers frame by frame. The last
sub-system deals with a NTXY database to calculate the pedestrian traffic-flow
characteristic such as flow rate, speed and area module. Comparison with manual
data collection method confirmed that the procedures described have significant
potential to automate the data collection of both microscopic and macroscopic
pedestrian flow variables.


title: Support points

abstract:
  This paper introduces a new way to compact a continuous probability
distribution $F$ into a set of representative points called support points.
These points are obtained by minimizing the energy distance, a statistical
potential measure initially proposed by Sz\'ekely and Rizzo (2004) for testing
goodness-of-fit. The energy distance has two appealing features. First, its
distance-based structure allows us to exploit the duality between powers of the
Euclidean distance and its Fourier transform for theoretical analysis. Using
this duality, we show that support points converge in distribution to $F$, and
enjoy an improved error rate to Monte Carlo for integrating a large class of
functions. Second, the minimization of the energy distance can be formulated as
a difference-of-convex program, which we manipulate using two algorithms to
efficiently generate representative point sets. In simulation studies, support
points provide improved integration performance to both Monte Carlo and a
specific Quasi-Monte Carlo method. Two important applications of support points
are then highlighted: (a) as a way to quantify the propagation of uncertainty
in expensive simulations, and (b) as a method to optimally compact Markov chain
Monte Carlo (MCMC) samples in Bayesian computation.


title:
Intermittent Control Properties of Car Following: Theory and Driving
  Simulator Experiments

abstract:
  A rather simple car driving simulator was created based on the available open
source engine TORCS and used to analyze the basic features of human behavior in
car driving within the car-following setups. Eight subjects with different
skill in driving real cars participated in these experiments. They were
instructed to drive a virtual car without overtaking the lead car driven by
computer at a fixed speed and not to lose sight of it. Moreover, these
experiments were conducted with four different speed including 60km/h, 80km/h,
100km/h, and 120km/h. Based on the collected data the distribution of the
headway, velocity, acceleration, and jerk are constructed and compared with
available experimental data collected previously by the analysis of the real
traffic flow. A new model for car-following is proposed capture the found
properties. As the main results we draw a conclusion that the human behavior in
car driving should be categorized as a generalized intermittent control with
noise-driven activation of the active phase. Besides, we hypothesize that the
extended phase space required for modeling human actions in car driving has to
comprise four phase variables, namely, the headway distance, the velocity of
car, its acceleration, and the car jerk, i.e., the time derivative of the car
acceleration. This time, the time pattern of pedal pushing and the distribution
of time derivative of pedal was utilized in addition to previous variables.
Moreover, all subjects' driving data were categorized as some styles with their
shapes.


title: Effect Of Running Shoes on Foot Impact During Running

abstract:
  Running is part of almost every sport, and requires a great amount of
stamina, endurance, mental toughness and overall strength. At every step, the
foot experiences ground reaction forces necessary to support the motion of the
body. With the advancements in shoe technology, running shoes have grown in
popularity among runners, as well as non-runners, because they reduce the risk
of injuries from the impact felt by the foot. The purpose of this report is to
analyze the effect of running shoes on impact forces on the foot. This is
achieved through the use of three force pads fixed at different locations on
the foot The force measured by each sensor is then used to estimate the
vertical ground reaction force, using the sensors' calibrations equations .
Based on the ground reaction force, the effective mass corresponding to the
momentum change occurring during the transient phase of the impact is
estimated. The results show that running at 9 miles per hour without running
shoes generates an effective mass of (14.9 +/- 4.8)% of the total body mass,
while running at the same speed with running shoes generates an effective mass
of (7.8 +/- 1.5 )% of the total body mass. The values highlight a significant
reduction in the risk of pain or injuries accomplished by wearing running shoes


title:
Molecular Dynamics Simulation of Strong Shock Waves Propagating in Dense
  Deuterium With the Effect of Excited Electrons

abstract:
  We present a molecular dynamics simulation of shock waves propagating in
dense deuterium with the electron force field method [J. T. Su and W. A.
Goddard, Phys. Rev. Lett. 99, 185003 (2007)], which explicitly takes the
excitation of electrons into consideration. Non-equilibrium features associated
with the excitation of electrons are systematically investigated. We show that
chemical bonds in D$_2$ molecules lead to a more complicated shock wave
structure near the shock front, compared with the results of classical
molecular dynamics simulation. Charge separation can bring about accumulation
of net charges on the large scale, instead of the formation of a localized
dipole layer, which might cause extra energy for the shock wave to propagate.
In addition, the simulations also display that molecular dissociation at the
shock front is the major factor corresponding to the "bump" structure in the
principal Hugoniot. These results could help to build a more realistic picture
of shock wave propagation in fuel materials commonly used in the inertial
confinement fusion.


title:
Dressed states of a quantum emitter strongly coupled to a metal
  nanoparticle

abstract:
  Hybrid molecular-plasmonic nanostructures have demonstrated their potential
for surface enhanced spectroscopies, sensing or quantum control at the
nanoscale. In this work, we investigate the strong coupling regime and
explicitly describe the hybridization between the localized plasmons of a metal
nanoparticle and the excited state of a quantum emitter, offering a simple and
precise understanding of the energy exchange in full analogy with cavity
quantum electrodynamics treatment and dressed atom picture. Both near field
emission and far field radiation are discussed, revealing the richness of such
optical nanosources.


title:
Using Dynamic Allocation of Write Voltage to Extend Flash Memory
  Lifetime

abstract:
  The read channel of a Flash memory cell degrades after repetitive program and
erase (P/E) operations. This degradation is often modeled as a function of the
number of P/E cycles. In contrast, this paper models the degradation as a
function of the cumulative effect of the charge written and erased from the
cell. Based on this modeling approach, this paper dynamically allocates voltage
using lower-voltage write thresholds at the beginning of the device lifetime
and increasing the thresholds as needed to maintain the mutual information of
the read channel in the face of degradation. The paper introduces the technique
in an idealized setting and then removes ideal assumptions about channel
knowledge and available voltage resolution to conclude with a practical scheme
with performance close to that of the idealized setting.


title:
401 and beyond: improved bounds and algorithms for the Ramsey algebra
  search

abstract:
  In this paper, we discuss an improvement of an algorithm to search for primes
$p$ and coset-partitions of Z/pZ* that yield Ramsey algebras over Z/pZ. We also
prove an upper bound on the modulus p in terms of the number of cosets. We
have, as a corollary, that there is no prime $p$ for which there exists a
partition of Z/pZ* into 13 cosets that yields a 13-color Ramsey algebra. Thus
A263308(13) = 0.


title:
Fluorescent H_2 Emission Lines from the Reflection Nebula NGC 7023
  Observed with IGRINS

abstract:
  We have analyzed the temperature, velocity and density of H2 gas in NGC 7023
with a high-resolution near-infrared spectrum of the northwestern filament of
the reflection nebula. By observing NGC 7023 in the H and K bands at R ~ 45,000
with the Immersion GRating INfrared Spectrograph (IGRINS), we detected 68 H2
emission lines within the 1" x 15" slit. The diagnostic ratios of 2-1 S(1)/1-0
S(1) is 0.41-0.56. In addition, the estimated ortho-to-para ratios (OPR) is
1.63-1.82, indicating that the H2 emission transitions in the observed region
arises mostly from gas excited by UV fluorescence. Gradients in the
temperature, velocity, and OPR within the observed area imply motion of the
photodissociation region (PDR) relative to the molecular cloud. In addition, we
derive the column density of H2 from the observed emission lines and compare
these results with PDR models in the literature covering a range of densities
and incident UV field intensities. The notable difference between PDR model
predictions and the observed data, in high rotational J levels of v = 1, is
that the predicted formation temperature for newly-formed H2 should be lower
than that of the model predictions. To investigate the density distribution, we
combine pixels in 1" x 1" areas and derive the density distribution at the
0.002 pc scale. The derived gradient of density suggests that NGC 7023 has a
clumpy structure, including a high clump density of ~10^5 cm^-3 with a size
smaller than ~5 x 10^-3 pc embedded in lower density regions of 10^3-10^4
cm^-3.


title: Semantic Video Trailers

abstract:
  Query-based video summarization is the task of creating a brief visual
trailer, which captures the parts of the video (or a collection of videos) that
are most relevant to the user-issued query. In this paper, we propose an
unsupervised label propagation approach for this task. Our approach effectively
captures the multimodal semantics of queries and videos using state-of-the-art
deep neural networks and creates a summary that is both semantically coherent
and visually attractive. We describe the theoretical framework of our
graph-based approach and empirically evaluate its effectiveness in creating
relevant and attractive trailers. Finally, we showcase example video trailers
generated by our system.


title: Replica symmetry breaking in trajectory space for the trap model

abstract:
  We study the localization in the one-dimensional trap model in terms of
statistical mechanics of trajectories. By numerically investigating overlap
between trajectories of two particles on a common disordered potential, we find
that there is a phase transition in the path ensemble. We characterize the low
temperature phase as a replica symmetry breaking phase in trajectory space.


title:
Bring-Your-Own-Device (BYOD): An Evaluation of Associated Risks to
  Corporate Information Security

abstract:
  This study evaluates the cyber-risks to Business Information Assets posed by
the adoption of Bring-Your-Own-Device (BYOD) to the workplace. BYOD is an
emerging trend where employees bring and use personal computing devices on the
companys network to access applications and sensitive data like emails,
calendar and scheduling applications, documents, etc. Employees are captivated
by BYOD because they can have access to private items as well as perform
certain job functions while being unrestricted to their desks. This is however
usually done on the blind side of management or the system administrator; a
situation that tends to expose vital and sensitive corporate information to
various threats like unwanted network traffic, unknown applications, malwares,
and viruses. Expert opinions were elicited in this exploratory study. The study
evaluated the characteristics of BYOD, assessed associated risks, threats and
vulnerabilities. The findings indicate that little or no security measures were
instituted to mitigate risks associated with BYOD. Though, profound benefits
abound with BYOD adoption, they could be eroded by security threats and costs
of mitigation in curing breaches. The most significant risk was found to be
Data Loss which was in consonance with similar studies on Smartphone security
risks. Some mitigation measures are then recommended.


title:
Multi-Tenancy Issues with Service Delivery in Developing Economies:
  Privacy, Trust and Availability Concerns

abstract:
  Cloud computing is a new paradigm and innovation in the technology service
delivery. It is utilized for IT-enabled value creation. The capex-free nature
of cloud service delivery renders it very attractive to many SMEs. But it is
saddled with multi-tenancy issues; prominent under this study are concerns of
privacy, trust and availability. How do end-users trust providers with their
sensitive data? How secured and confidential are their corporate assets? Amidst
the perennial power outages (a.k.a. Dumsor), what is the acceptable available
uptime? We sampled and interviewed cloud service providers (CSPs) as well as
end-users in Ghana, a developing economy. We also gleaned through some
secondary data to ascertain some operational concerns. The results indicate
that security and service level agreements (SLAs) are key concerns in respect
of privacy and trust issues. Similarly, perennial power outages and security
were key availability concerns. This was expected as end-users use cloud
services for mission critical information assets, and so requires high
availability. The implications are that the cyber-security concerns ought to be
addressed if SMEs in developing economies are to adopt and accept cloud
computing resources for IT-enabled competitive advantage.


title:
Challenges to Integration of Information Technology in Physical
  Infrastructure Development Processes at the Local Government Level

abstract:
  Ghana's Decentralization Policy has made significant contribution in
infrastructural implementation and delivery through Metropolitan, Municipal and
District Assemblies as an alternative development strategy to ensure the
implementation of the overall national agenda. To date, many systems and
strategies have been implemented towards improving development of
infrastructure at the local government level. Given that initiation and
implementation of infrastructural development at the local level involves the
multi-institutional participation of various stakeholders in local governance
for effective monitoring and development, several governance forms including
e-governance have been initiated towards improvement and effective management
of the assemblies. E-Governance through the use of relevant Information and
Communication Technology has been implemented through the Government Policy on
Information and Communications Technology for Accelerated Development as a
catalyst to facilitate the cross-sectoral participation in the implementation
of infrastructural development. Unfortunately, to date, the ICT4AD does not
appear to be successfully on course having been in existence for over a decade.
Similarly, the development and monitoring of the physical infrastructure at the
local level continue to suffer several setbacks and it is currently clearly
evident that a refined system of best practices must be put in place to
simplify and harmonize the entire development process. This paper is aimed at
the assessment of the challenges of e-governance in infrastructural development
at the local government level in Ghana. Using a mixed approach with purposive
sampling, data gathered from the MMDAs in Ashanti Region suggest that the
entire programme has been very slow; bedeviled with lack of funding and


title: Why scalar-tensor equivalent theories are not physically equivalent?

abstract:
  Whether Jordan's and Einstein's frame descriptions of F(R) theory of gravity
are physically equivalent, is a long standing debate. However, practically none
questioned on true mathematical equivalence, since classical field equations
may be translated from one frame to the other following a transformation
relation. Here we show that neither Noether symmetries, Noether equations, nor
may quantum equations be translated from one to the other. The reason being, -
conformal transformation results in a completely different system, with a
different Lagrangian. Field equations match only due to the presence of
diffeomorphic invariance. Unless a symmetry generator is found which involves
Hamiltonian constraint equation, the mathematical equivalence between the two
frames appears to be vulnerable. In any case, in quantum domain Mathematical
and therefore physical equivalence can't be established.


title:
$L^2$-contraction of large planar shock waves for multi-dimensional
  scalar viscous conservation laws

abstract:
  We consider a $L^2$-contraction of large viscous shock waves for the
multi-dimensional scalar viscous conservation laws, up to a suitable shift. The
shift function depends on the time and space variables. It solves a parabolic
equation with inhomogeneous coefficients reflecting the perturbation. We
consider a suitably small $L^2$-perturbation around a viscous planar shock wave
of arbitrarily large strength. However, we do not impose any condition on the
anti-derivative variables of the perturbation around shock profile. More
precisely, it is proved that if the initial perturbation around the viscous
shock wave is suitably small in the $L^2$ norm, then the $L^2$-contraction
holds true for the viscous shock wave up to a shift function which may depend
on the temporal and spatial variables. Moreover, as the time $t$ tends to
infinity, the $L^2$-contraction holds true up to a time-dependent shift
function. In particular, if we choose some special initial perturbation, then
we can prove a $L^2$ convergence of the solutions towards the associated shock
profile up to a time-dependent shift.


title:
Fundamental Storage-Latency Tradeoff in Cache-Aided MIMO Interference
  Networks

abstract:
  Caching is an effective technique to improve user perceived experience for
content delivery in wireless networks. Wireless caching differs from
traditional web caching in that it can exploit the broadcast nature of wireless
medium and hence opportunistically change the network topologies. This paper
studies a cache-aided MIMO interference network with 3 transmitters each
equipped with M antennas and 3 receivers each with N antennas. With caching at
both the transmitter and receiver sides, the network is changed to hybrid forms
of MIMO broadcast channel, MIMO X channel, and MIMO multicast channels. We
analyze the degrees of freedom (DoF) of these new channel models using
practical interference management schemes. Based on the collective use of these
DoF results, we then obtain an achievable normalized delivery time (NDT) of the
network, an information-theoretic metric that evaluates the worst-case delivery
time at given cache sizes. The obtained NDT is for arbitrary M, N and any
feasible cache sizes. It is shown to be optimal in certain cases and within a
multiplicative gap of 3 from the optimum in other cases. The extension to the
network with arbitrary number of transmitters and receivers is also discussed.


title:
Optical far-field super-resolution microscopy using nitrogen vacancy
  center ensemble in bulk diamond

abstract:
  We demonstrate an optical far-field super-resolution microscopy using array
of nitrogen vacancy centers in bulk diamond as near-field optical probes. The
local optical field, which transmits through the nanostructures on the diamond
surface, is measured by detecting the charge state conversion of nitrogen
vacancy center. And the locating of nitrogen vacancy center with spatial
resolution of 6.1 nm is realized with the charge state depletion nanoscopy. The
nanostructures on the surface of diamond are then imaged with resolution below
optical diffraction limit. The results offer an approach to built a
general-purpose optical super-resolution microscopy and a convenient platform
for high spatial resolution quantum sensing with nitrogen vacancy center.


title: Delaunay Triangulation on Skeleton of Flowers for Classification

abstract:
  In this work, we propose a Triangle based approach to classify flower images.
Initially, flowers are segmented using whorl based region merging segmentation.
Skeleton of a flower is obtained from the segmented flower using a skeleton
pruning method. The Delaunay triangulation is obtained from the endpoints and
junction points detected on the skeleton. The length and angle features are
extracted from the obtained Delaunay triangles and then are aggregated to
represent in the form of interval-valued type data. A suitable classifier has
been explored for the purpose of classification. To corroborate the efficacy of
the proposed method, an experiment is conducted on our own data set of 30
classes of flowers, containing 3000 samples.


title: Animal Classification System: A Block Based Approach

abstract:
  In this work, we propose a method for the classification of animal in images.
Initially, a graph cut based method is used to perform segmentation in order to
eliminate the background from the given image. The segmented animal images are
partitioned in to number of blocks and then the color texture moments are
extracted from different blocks. Probabilistic neural network and K-nearest
neighbors are considered here for classification. To corroborate the efficacy
of the proposed method, an experiment was conducted on our own data set of 25
classes of animals, which consisted of 4000 sample images. The experiment was
conducted by picking images randomly from the database to study the effect of
classification accuracy, and the results show that the K-nearest neighbors
classifier achieves good performance.


title:
Algorithms For Shaping a Particle Swarm With a Shared Control Input
  Using Boundary Interaction

abstract:
  Consider a swarm of particles controlled by global inputs. This paper
presents algorithms for shaping such swarms in 2D using boundary walls. The
range of configurations created by conforming a swarm to a boundary wall is
limited. We describe the set of stable configurations of a swarm in two
canonical workspaces, a circle and a square. To increase the diversity of
configurations, we add boundary interaction to our model. We provide algorithms
using friction with walls to place two robots at arbitrary locations in a
rectangular workspace. Next, we extend this algorithm to place $n$ agents at
desired locations. We conclude with efficient techniques to control the
covariance of a swarm not possible without wall-friction. Simulations and
hardware implementations with 100 robots validate these results.
  These methods may have particular relevance for current micro- and
nano-robots controlled by global inputs.


title:
Dynamical parton distributions from DGLAP equations with nonlinear
  corrections

abstract:
  Determination of proton parton distribution functions is present under the
dynamical parton model assumption by applying DGLAP equations with GLR-MQ-ZRS
corrections. We provide two data sets, referred as IMParton16, which are from
two different nonperturbative inputs. One is the naive input of three valence
quarks and the other is the input of three valence quarks with
flavor-asymmetric sea components. Basically, both data sets are compatible with
the experimental measurements at high scale ($Q^2>2$ GeV$^2$). Furthermore, our
analysis shows that the input with flavor-asymmetric sea components better
reproduce the structure functions at high $Q^2$. Generally, the obtained parton
distribution functions, especially the gluon distribution function, are the
good options of inputs for simulations of high energy scattering processes. The
analysis is performed under the fixed-flavor number scheme for $n_f=$ 3, 4, 5.
Both data sets start from very low scales around 0.07 GeV$^2$, where the
nonperturbative input is directly connected to the simple picture of quark
model. These results may shed some lights on the origin of the parton
distributions observed at high $Q^2$.


title: Off-shell BCJ Relation in Nonlinear Sigma Model

abstract:
  We investigate relations among tree-level off-shell currents in nonlinear
sigma model. Under Cayley parametrization, we propose and prove a general
revised BCJ relation for even-point currents. Unlike the on-shell BCJ relation,
the off-shell one behaves quite differently from Yang-Mills theory although the
algebraic structure is the same. After performing the permutation summation in
the revised BCJ relation, the sum is non-vanishing, instead, it equals to the
sum of sub-current products with the BCJ coefficients under a specific
ordering, which is presented by an explicit formula. Taking on-shell limit,
this identity is reduced to the on-shell BCJ relation, and thus provides the
full off-shell correspondence of tree-level BCJ relation in nonlinear sigma
model.


title:
Trace distance and scaling behavior of coupled cavity lattice at finite
  temperature

abstract:
  We use an alternative approach to study the quantum phase transition in a
coupled cavity lattice at finite temperature. As an illustrative example, we
investigate the behaviors of the trace distance and quantum phase transition in
a Jaynes-Cummings lattice at finite temperature. It is found that the trace
distance can be used to describe the critical point of the quantum phase
transition at finite low temperatures and the critical points are sensitive to
the atom-field interaction strength and the detuning factor. For
non-equilibrium states, we demonstrate that the time evolution of the trace
distance's maximum value is also a good indicator of the critical points.
Moreover, we show that the scaling behavior of derivative of the trace distance
at the critical points and the scaling rule are dependent on the external
parameters of the Hamiltonian.


title: On the extension and smoothing of the Calabi flow on complex tori

abstract:
  In this paper, we continue to study the Calabi flow on complex tori. We
develop a new method to obtain an explicit bound of the curvature of the Calabi
flow. As an application, we show that when $n=2$, the Calabi flow starting from
a weak K\"ahler metric will become smooth immediately. It implies that in our
settings, the weak minimizer of the Mabuchi energy is a smooth one.


title:
Quantum phase transition by employing trace distance along with the
  density matrix renormalization group

abstract:
  We use an alternative method to investigate the quantum criticality at zero
and finite temperature using trace distance along with the density matrix
renormalization group. It is shown that the average correlation measured by the
trace distance between the system block and environment block in a DMRG sweep
is able to detect the critical points of quantum phase transitions at finite
temperature. As illustrative examples, we study spin-1 XXZ chains with uniaxial
single-ion-type anisotropy and the Heisenberg spin chain with staggered
coupling and external magnetic field. It is found that the trace distance shows
discontinuity at the critical points of quantum phase transition and can be
used as an indicator of QPTs.


title:
Generation and cessation of oscillations: Interplay of excitability and
  dispersal in a class of ecosystem

abstract:
  We investigate the complex spatiotemporal dynamics of an ecological network
with species dispersal mediated via a mean-field coupling. The local dynamics
of the network are governed by the Truscott--Brindley model, which is an
important ecological model showing excitability. Our results focus on the
interplay of excitability and dispersal by always considering that the
individual nodes are in their (excitable) steady states. In contrast to the
previous studies, we not only observe the dispersal induced generation of
oscillation but we also report two distinct mechanisms of cessation of
oscillations, namely amplitude and oscillation death. We show that, the
dispersal between the nodes influences the intrinsic dynamics of the system
resulting multiple oscillatory dynamics such as period-1 and period-2 limit
cycles. We also show the existence of multi-cluster states which has much
relevance and importance in ecology.


title: Holographic Topological Insulator

abstract:
  This research highlight (originally published at
http://www.ntu.edu.sg/ias/newsletters/Documents/APPN/APPNv5n2May2016-lowres.pdf)
introduces recent developments in Topological Insulators and Holography, and
provides an overview of how one can construct a holographic bulk topological
insulator from a boundary Chern insulator with small gap.


title: Curves of medium genus with many points

abstract:
  The defect of a curve over a finite field is the difference between the
number of rational points on the curve and the Weil-Serre upper bound for the
number of points on the curve. We present algorithms for constructing curves of
genus 5, 6, and 7 with small defect. Our aim is to be able to produce, in a
reasonable amount of time, curves that can be used to populate the online table
of curves with many points found at http://www.manypoints.org.


title: Guided Filter based Edge-preserving Image Non-blind Deconvolution

abstract:
  In this work, we propose a new approach for efficient edge-preserving image
deconvolution. Our algorithm is based on a novel type of explicit image filter
- guided filter. The guided filter can be used as an edge-preserving smoothing
operator like the popular bilateral filter, but has better behaviors near
edges. We propose an efficient iterative algorithm with the decouple of
deblurring and denoising steps in the restoration process. In deblurring step,
we proposed two cost function which could be computed with fast Fourier
transform efficiently. The solution of the first one is used as the guidance
image, and another solution will be filtered in next step. In the denoising
step, the guided filter is used with the two obtained images for efficient
edge-preserving filtering. Furthermore, we derive a simple and effective method
to automatically adjust the regularization parameter at each iteration. We
compare our deconvolution algorithm with many competitive deconvolution
techniques in terms of ISNR and visual quality.


title: Learning Boltzmann Machine with EM-like Method

abstract:
  We propose an expectation-maximization-like(EMlike) method to train Boltzmann
machine with unconstrained connectivity. It adopts Monte Carlo approximation in
the E-step, and replaces the intractable likelihood objective with efficiently
computed objectives or directly approximates the gradient of likelihood
objective in the M-step. The EM-like method is a modification of alternating
minimization. We prove that EM-like method will be the exactly same with
contrastive divergence in restricted Boltzmann machine if the M-step of this
method adopts special approximation. We also propose a new measure to assess
the performance of Boltzmann machine as generative models of data, and its
computational complexity is O(Rmn). Finally, we demonstrate the performance of
EM-like method using numerical experiments.


title:
Exploring nonnormality in magnetohydrodynamic rotating shear flows:
  application to astrophysical accretion disks

abstract:
  The emergence of turbulence in shear flows is a well-investigated field. Yet,
one of major issues is the apparent contradiction between linear stability
analysis quoting a flow to be stable and results from experiments and
simulations proving it to be otherwise. There is some success, in particular in
astrophysical systems, based on Magneto-Rotational Instability (MRI). However,
MRI requires the system to be weakly magnetized, which is not a feature of
general magnetohydrodynamic (MHD) flows. Nevertheless, linear perturbations of
such flows are nonnormal in nature which argues for an origin of nonlinearity
therein. The idea is, nonnormal perturbations could produce huge transient
energy growth (TEG), which may lead to non-linearity and further turbulence.
However, so far, nonnormal effects in shear flows have not been explored much
in the presence of magnetic fields. Here, we consider the perturbed
visco-resistive incompressible MHD shear flows with rotation in general.
Basically we consider the magnetized version of Orr-Sommerfeld and Squire
equations and their magnetic analogues in the presence of Coriolis effect. We
solve the equations using a pseudospectral eigenvalue approach. We investigate
the possible emergence of instability and large TEG in three different flows:
the Keplerian, constant angular momentum and plane Couette flows. We show that,
above a certain value of magnetic field, instability and TEG both stop
occurring. We also show that TEG is maximum near the regions of instability in
the wave number space for a given magnetic field and Reynolds number. Rotating
shear flows are ubiquitous in astrophysics, especially accretion disks, where
molecular viscosity is too low to account for observed data. The primary
accepted cause of energy-momentum transport therein is turbulent viscosity.
Hence, these results would have important implications in astrophysics.


title:
Spin-Polarized Surface Resonances Accompanying Topological Surface State
  Formation

abstract:
  Topological insulators host spin-polarized surface states born out of the
energetic inversion of bulk bands driven by the spin-orbit interaction. Here we
discover previously unidentified consequences of band-inversion on the surface
electronic structure of the topological insulator Bi$_2$Se$_3$. By performing
simultaneous spin, time, and angle-resolved photoemission spectroscopy, we map
the spin-polarized unoccupied electronic structure and identify a surface
resonance which is distinct from the topological surface state, yet shares a
similar spin- orbital texture with opposite orientation. Its momentum-
dependence and spin texture imply an intimate connection with the topological
surface state. Calculations show these two distinct states can emerge from
trivial Rashba-like states that change topology through the spin-orbit-induced
band inversion. This work thus provides a compelling view of the coevolution of
surface states through a topological phase transition, enabled by the unique
capability of directly measuring the spin-polarized unoccupied band structure.


title: On Transfer Function Realizations for Linear Quantum Stochastic Systems

abstract:
  The realization of transfer functions of Linear Quantum Stochastic Systems
(LQSSs) is an issue of fundamental importance for the practical applications of
such systems, especially as coherent controllers for other quantum systems. In
this paper, we review two realization methods proposed by the authors in [1],
[2], [3], [4]. The first one uses a cascade of a static linear quantum-optical
network and single-mode optical cavities, while the second uses a feedback
network of such cavities, along with static linear quantum-optical networks
that pre- and post-process the cavity network inputs and outputs.


title: FO Aqr time keeping

abstract:
  Twelve seasons, from 2004 to 2015, of photometric monitoring of the
intermediate polar FO Aqr are presented and are compared with previous
observations. The ambiguities in the cycle counting can be lifted and a new O-C
diagram, spanning 34 yr, is presented, along with new ephemerides.


title: High-order exceptional points in optomechanics

abstract:
  We study mechanical cooling in systems of coupled passive (lossy) and active
(with gain) optical resonators. We find that for a driving laser which is
red-detuned with respect to the cavity frequency, the supermode structure of
the system is radically changed, featuring the emergence of genuine high-order
exceptional points. This in turn leads to giant enhancement of both the
mechanical damping and the spring stiffness, facilitating low-power mechanical
cooling in the vicinity of gain-loss balance. This opens up new avenues of
steering micromechanical devices with exceptional points beyond the
lowest-order two.


title:
Molecular components in $\mathbf{D_{s0}^{\ast}(2317)}$ and
  $\mathbf{D_{s1}(2460)}$ mesons

abstract:
  Different experiments have confirmed that the $D_{s0}^{\ast}(2317)$ and
$D_{s1}(2460)$ mesons are very narrow states located, respectively, below the
$DK$ and $D^{\ast}K$ thresholds. This is markedly in contrast with the
expectations of naive quark models and heavy quark symmetry. We address the
mass shifts of the $c\bar{s}$ ground states with quantum numbers $J^{P}=0^{+}$
($D_{s0}^{\ast}(2317)$) and $J^{P}=1^{+}$ ($D_{s1}(2460)$) using a
nonrelativistic constituent quark model in which quark-antiquark and
meson-meson degrees of freedom are incorporated. The quark model has been
applied to a wide range of hadronic observables and thus the model parameters
are completely constrained. We observe that the coupling of the $0^{+}$
$(1^{+})$ meson sector to the $DK$ $(D^{\ast}K)$ threshold is a key feature in
lowering the masses of the corresponding $D_{s0}^{\ast}(2317)$ and
$D_{s1}(2460)$ states predicted by the naive quark model, but also in
describing the $D_{s1}(2536)$ meson as the $1^{+}$ state of the
$j_{q}^{P}=3/2^{+}$ doublet predicted by heavy quark symmetry and thus
reproducing its strong decay properties. Two features of our formalism cannot
be address nowadays by other approaches: the coupling of the $D$-wave
$D^{\ast}K$ threshold in the $J^{P}=1^{+}$ $c\bar{s}$ channel and the
computation of the probabilities associated with different Fock components in
the physical state.


title: Exceptional spectra of the two-qubit quantum Rabi model

abstract:
  In this report, we have studied exceptional spectra of the two-qubit quantum
Rabi model in two situations. Firstly, an exceptional spectra is achieved in
resonant condition, in which the frequencies of two qubit and photon field
satisfy resonant relation. With transformed rotating-wave approximation (TRWA)
method, the Rabi model can be mapped into the solvable formation in
qubit-photon Fock states space. Based on the quantum supperconducting circuits
experiment setup, the best value range of the system parameters are discussed.
In the resonant station working window, the energy spectrums are calculated.
Secondly, a special quasi-exact solution of two qubits Rabi model in reservoir
is achieved. The algebraic structure of Hamiltonian is analyzed in the photon
number space, a closed quasi-exact eigenstates space is found, and the
quasi-exact solution can be clearly found from the algebraic structure of
Hamiltonian. The results could be used to test quantum Rabi model.


title:
Effect of background magnetic field on the normal modes of conformal
  dissipative chiral hydro and a novel mechanism for explaining pulsar kicks

abstract:
  In the present work, we have studied the collective behaviour of a chiral
plasma with first and second order dissipative corrections allowed by conformal
symmetry. We have derived dispersion relations for ideal, first order and
second order MHD for the chiral plasma. We have also used our results to
explain the observed pulsar kicks.

categories: hep-ph astro-ph.CO hep-th physics.plasm-ph


title:
Strong magnetoelastic coupling at the transition from harmonic to
  anharmonic order in NaFe(WO$_4$)$_2$ with 3d$^5$ configuration

abstract:
  The crystal structure of the double tungstate NaFe(WO$_4$)$_2$ arises from
that of the spin-driven multiferroic MnWO$_4$ by inserting non-magnetic Na
layers. NaFe(WO$_4$)$_2$ exhibits a three-dimensional incommensurate
spin-spiral structure at low temperature and zero magnetic field, which,
however, competes with commensurate order induced by magnetic field. The
incommensurate zero-field phase corresponds to the condensation of a single
irreducible representation but it does not imply ferroelectric polarization
because spirals with opposite chirality coexist. Sizable anharmonic modulations
emerge in this incommensurate structure, which are accompanied by large
magneto-elastic anomalies, while the onset of the harmonic order is invisible
in the thermal expansion coefficient. In magnetic fields applied along the
monoclinic axis, we observe a first-order transition to a commensurate
structure that again is accompanied by large magneto-elastic effects. The large
magnetoelastic coupling, a reduction of the $b$ lattice parameter, is thus
associated only with the commensurate order. Upon releasing the field at low
temperature, the magnetic order transforms to another commensurate structure
that considerably differs from the incommensurate low-temperature phase
emerging upon zero-field cooling. The latter phase, which exhibits a reduced
ordered moment, seems to be metastable.


title:
Cosmological constraints from thermal Sunyaev Zeldovich power spectrum
  revisited

abstract:
  Thermal Sunyaev-Zeldovich (tSZ) power spectrum is one of the most sensitive
methods to constrain cosmological parameters, scaling as the amplitude
$\sigma_8^8$. It is determined by the integral over the halo mass function
multiplied by the total pressure content of clusters, and further convolved by
the cluster gas pressure profile. It has been shown that various feedback
effects can change significantly the pressure profile, possibly even pushing
the gas out to the virial radius and beyond, strongly affecting the tSZ power
spectrum at high $l$. Energetics arguments and SZ-halo mass scaling relations
suggest feedback is unlikely to significantly change the total pressure
content, making low $l$ tSZ power spectrum more robust against feedback
effects. Furthermore, the separation between the cosmic infrared background
(CIB) and tSZ is more reliable at low $l$. Low $l$ modes are however probing
very small volumes, giving rise to very large non-gaussian sampling variance
errors. By computing the trispectrum contribution we identify $90<l<350$ as the
minimum variance scale where the combined error is minimized. Using the
measurement at this $l$ provides constraints that are almost as strong as using
the entire power spectrum. We extend the work by the Planck collaboration by
including a full trispectrum and feedback effects in the analysis. We perform a
Markov-Chain Monte Carlo analysis over the two dimensional parameter space and
find constraints on $\sigma_8$ by marginalizing over the feedback nuisance
parameter.We obtain $\sigma_8
=0.820^{+0.021}_{-0.009}\left(\Omega_m/0.31\right)^{0.4}$, when fixing other
parameters to Planck cosmology values. Our results suggest it is possible to
obtain competitive cosmological constraints from tSZ without cluster redshift
information, and that the current tSZ power spectrum shows no evidence for a
low amplitude of $\sigma_8$.


title:
Behaviour of elements from lithium to europium in stars with and without
  planets

abstract:
  We conducted an analysis of the distribution of elements from lithium to
europium in 200 dwarfs in the solar neighbourhood ~20 pc with temperatures in
the range 4800-6200 K and metallicities [Fe/H] higher than -0.5 dex.
Determinations of atmospheric parameters and the chemical composition of the
dwarfs were taken from our previous studies. We found that the lithium
abundances in the planet-hosting solar-analog stars of our sample were lower
than those in the stars without planetary systems. Our results reveal no
significant differences exceeding the determination errors for the abundances
of investigated elements, except for aluminium and barium, which are more and
less abundant in the planet-hosting stars, respectively. We did not find
confident dependences of the lithium, aluminium and barium abundances on the
ages of our target stars (which is probable because of the small number of
stars). Furthermore, we found no correlation between the abundance differences
in [El/Fe] and the condensation temperature (Tcond) for stars in the 16 Cyg
binary system, unlike the case for 51 Peg (HD 217014), for which a slight
excess of volatile elements and a deficit of refractories were obtained
relative to those of solar twins. We found that one of the components of 16 Cyg
exhibits a slightly higher average abundance than its counterpart
(<[El/H](A-B)> = 0.08+/-0.02 dex); however, no significant abundance trend
versus Tcond was observed. Owing to the relatively large errors, we cannot
provide further constraints for this system.


title: Linear differential equations with slowly growing solutions

abstract:
  This research concerns coefficient conditions for linear differential
equations in the unit disc of the complex plane. In the higher order case the
separation of zeros (of maximal multiplicity) of solutions is considered, while
in the second order case slowly growing solutions in $H^\infty$, $\rm{BMOA}$
and the Bloch space are discussed. A counterpart of the Hardy-Stein-Spencer
formula for higher derivatives is proved, and then applied to study solutions
in the Hardy spaces.


title:
Modeling of a heat capacity peak and an enthalpy jump for a
  paraffin-based phase-change material

abstract:
  Rubitherm RT 27 is a paraffin-based phase-change material (PCM) in which a
change between a solid and liquid phase is used to store/release thermal
energy. Its enthalpy and heat capacity, as measured in a quasistatic regime by
adiabatic scanning calorimetry, has a single distinct jump and peak,
respectively, at about 27.3 C. We present a microscopic development from which
the jump and peak can be accurately fitted and that could be analogously
applied even to other PCMs. It enables us to determine the baseline and excess
part of the heat capacity and thus the latent heat associated with the phase
change. It is shown to be about 84 % of the total enthalpy change that occurs
within 5 C from the peak maximum position. The development is based on the
observation that PCMs often have polycrystalline structure, being composed of
many single-crystalline grains. The enthalpy and heat capacity measured in
experiments are therefore interpreted as superpositions of many contributions
that come from the individual grains.


title: A Note on the Speed of Perfect State Transfer

abstract:
  In Phys. Rev. A 74, 030303 (2006), Yung showed that for a one-dimensional
spin chain of length $N$ and maximum coupling strength $J_{\max}$, the time
$t_0$ for a quantum state to transfer from one end of the chain to another is
bounded by $J_{\max} t_0\geq\pi(N-1)/4$ (even $N$) and $J_{\max}
t_0\geq\pi\sqrt{N^2-1}/4$ (odd $N$). The proof for even $N$ was elegant, but
the proof for odd $N$ was less so. This note provides a proof for the odd $N$
case that is simpler, and more in keeping with the proof for the even case.


title:
Boundary layer flow and heat transfer of Cross fluid over a stretching
  sheet

abstract:
  The current study is a pioneering work in presenting the boundary layer
equations for the two-dimensional flow and heat transfer of the Cross fluid
over a linearly stretching sheet. The system of partial differential equations
is turned down into highly non-linear ordinary differential equations by
applying suitable similarity transformations. The stretching sheet solutions
are presented via. a numerical technique namely the shooting method and graphs
are constructed for the shear-thinning as well as shear-thickening regime. The
impact of the emerging parameters namely the power-law index , the local
Weissenberg number and the Prandtl number on the velocity and temperature
fields are investigated through graphs. Numerical values of the local skin
friction coefficient and the local Nusselt number are also presented in tabular
form. For some limiting cases, comparisons with previously available results in
the literature are made and an excellent agreement is achieved.


title:
A Survey of Downlink Non-orthogonal Multiple Access for 5G Wireless
  Communication Networks

abstract:
  Non-orthogonal multiple access (NOMA) has been recognized as a promising
multiple access technique for the next generation cellular communication
networks. In this paper, we first discuss a simple NOMA model with two users
served by a single-carrier simultaneously to illustrate its basic principles.
Then, a more general model with multicarrier serving an arbitrary number of
users on each subcarrier is also discussed. An overview of existing works on
performance analysis, resource allocation, and multiple-input multiple-output
NOMA are summarized and discussed. Furthermore, we discuss the key features of
NOMA and its potential research challenges.


title: Exact Mappings in Condensed Matter Physics

abstract:
  Condensed matter systems are complex yet simple. Amidst their complexity, one
often find order specified by not more than a few parameters. Key to such a
reductionistic description is an appropriate choice of basis, two of which I
shall describe in this thesis.
  The first, an exact mapping known as the Wannier State Representation (WSR),
provides an exact Hilbert space correspondence between two intensely-studied
topological systems, the Fractional Quantum Hall (FQH) and Fractional Chern
Insulator (FCI) systems. FQH states exist within the partially filled Landau
levels of interacting 2D electron gases under strong magnetic fields, where
quasiparticles exhibit topologically nontrivial braiding statistics. FCI
systems, which are novel lattice realizations of FQH systems without orbital
magnetic field, are still not completely understood and will benefit from a
basis that explicitly connects them to the much better understood FQH systems.
  The second basis mapping, the Exact Holographic Mapping (EHM), maps any
lattice system to a holographic 'bulk' with an additional emergent dimension
representing energy scale. Devised in the spirit of the highly popular AdS-CFT
correspondence, it attempts to understand the relationship between a given
system and its equivalent dual geometry. In particular, we found excellent
theoretical agreement of certain dual geometries from EHM with those expected
from the Ryu-Takanayagi formula relating the bulk geometry with entanglement
entropy. Additionally, the EHM also proves useful in providing a link between
different topological quantities, such as relating the Chern number of the
abovementioned Chern Insulators with the Axion angle of 3D topological
insulators.


title: SO(10) model of standard and dark matter

abstract:
  We consider a novel model for three standard families of left chiral states
of quarks and leptons conjointly with a new family of dark matter fermionic
particles and a sterile neutrino. It is suggested to use a SO(10) symmetry for
description of these families for the first time. It is presented estimations
of masses of dark matter particles and the sterile neutrino as well limitations
for values of mixing parameters between the new family particles and active
neutrinos. This model can be used for predictions and interpretations of
results of experiments for sterile neutrino and dark matter particles search.


title: Automatic Visual Theme Discovery from Joint Image and Text Corpora

abstract:
  A popular approach to semantic image understanding is to manually tag images
with keywords and then learn a mapping from vi- sual features to keywords.
Manually tagging images is a subjective pro- cess and the same or very similar
visual contents are often tagged with different keywords. Furthermore, not all
tags have the same descriptive power for visual contents and large vocabulary
available from natural language could result in a very diverse set of keywords.
In this paper, we propose an unsupervised visual theme discovery framework as a
better (more compact, efficient and effective) alternative to semantic
represen- tation of visual contents. We first show that tag based annotation
lacks consistency and compactness for describing visually similar contents. We
then learn the visual similarity between tags based on the visual features of
the images containing the tags. At the same time, we use a natural language
processing technique (word embedding) to measure the seman- tic similarity
between tags. Finally, we cluster tags into visual themes based on their visual
similarity and semantic similarity measures using a spectral clustering
algorithm. We conduct user studies to evaluate the effectiveness and
rationality of the visual themes discovered by our unsu- pervised algorithm and
obtains promising result. We then design three common computer vision tasks,
example based image search, keyword based image search and image labelling to
explore potential applica- tion of our visual themes discovery framework. In
experiments, visual themes significantly outperforms tags on semantic image
understand- ing and achieve state-of-art performance in all three tasks. This
again demonstrate the effectiveness and versatility of proposed framework.


title:
RRDVCR: Real-Time Reliable Data Delivery Based on Virtual Coordinating
  Routing for Wireless Sensor Networks

abstract:
  Real-time industrial application requires routing protocol that guarantees
data delivery with reliable, efficient and low end-to-end delay. Existing
Routing(THVR) [13] is based velocity of Two-Hop Velocity and protocol relates
two-hop velocity to delay to select the next forwarding node, that has overhead
of exchanging control packets, and depleting the available energy in nodes. We
propose a Real-Time Reliable Data delivery based on Virtual Coordinates Routing
(RRDVCR) algorithm, based on the number of hops to the destination rather than
geographic distance. Selection of forwarding node is based on packet progress
offered by two-hops, link quality and available energy at the forwarding nodes.
All these metric are co-related by dynamic co-relation factor. The proposed
protocol uses selective acknowledgment scheme that results in lower overhead
and energy consumption. Simulation results shows that there is about 22% and
9.5% decrease in energy consumption compared to SPEED [8] and THVR [13]
respectively, 16% and 38% increase in packet delivery compared to THVR [13] and
SPEED[8] respectively, and overhead is reduced by 50%.


title: Magnetic decoupling of ferromagnetic metals through a graphene spacer

abstract:
  We study the magnetic coupling between different ferromagnetic metals (FMs)
across a graphene (G) layer, and the role of graphene as a thin covalent
spacer. Starting with G grown on a FM substrate (Ni or Co), we deposit on top
at room temperature different FM metals (Fe, Ni, Co). By measuring the dichroic
effect of 3p photoemission lines we detect the magnetization of the substrate
and the sign of the exchange coupling in FM overlayer at room temperature. We
show that the G layer magnetically decouples the FM metals.


title: General relativity and relativistic astrophysics

abstract:
  Einstein established the theory of general relativity and the corresponding
field equation in 1915 and its vacuum solutions were obtained by Schwarzschild
and Kerr for, respectively, static and rotating black holes, in 1916 and 1963,
respectively. They are, however, still playing an indispensable role, even
after 100 years of their original discovery, to explain high energy
astrophysical phenomena. Application of the solutions of Einstein's equation to
resolve astrophysical phenomena has formed an important branch, namely
relativistic astrophysics. I devote this article to enlightening some of the
current astrophysical problems based on general relativity. However, there seem
to be some issues with regard to explaining certain astrophysical phenomena
based on Einstein's theory alone. I show that Einstein's theory and its
modified form, both are necessary to explain modern astrophysical processes, in
particular, those related to compact objects.


title:
Observation of Nonlocality Sharing among Three Observers with One
  Entangled Pair via Optimal Weak Measurement

abstract:
  Bell nonlocality plays a fundamental role in quantum theory. Numerous tests
of the Bell inequality have been reported since the ground-breaking discovery
of the Bell theorem.Up to now, however, most discussions of the Bell scenario
have focused on a single pair of entangled particles distributed to only two
separated observers. Recently, it has been shown surprisingly that multiple
observers can share the nonlocality present in a single particle from an
entangled pair using the method of weak measurements [Phys. Rev. Lett. {\bf
114}, 250401 (2015)]. Here we report an observation of double CHSH-Bell
inequality violations for a single pair of entangled photons with strength
continuous-tunable optimal weak measurements in photonic system for the first
time. Our results not only shed new light on the interplay between nonlocality
and quantum measurements but may also be significant for important applications
such as unbounded randomness certification and quantum steering.


title:
CP violating phase from minimal texture neutrino mass matrix: Test of
  the phase relevant to leptogenesis

abstract:
  The model of neutrino mass matrix with minimal texture is now tightly
constrained by experiment so that it can yield a prediction for the phase of CP
violation. This phase is predicted to lie in the range $\delta_{CP}=0.77\pi -
1.24\pi$. If neutrino oscillation experiment would find the CP violation phase
outside this range, this means that the minimal-texture neutrino mass matrix,
the element of which is all real, fails and the neutrino mass matrix must be
complex, i.e., the phase must be present that is responsible for leptogenesis.


title:
Line nodes and surface Majorana flat bands in static and kicked p-wave
  superconducting Harper model

abstract:
  We investigate the effect of introducing nearest-neighbor $p$-wave
superconducting pairing to both the static and kicked extended Harper model
with two periodic phase parameters acting as artificial dimensions to simulate
three-dimensional systems. It is found that in both the static model and the
kicked model, by varying the $p$-wave pairing order parameter, the system can
switch between a fully gapped phase and a gapless phase with point nodes or
line nodes. The topological property of both the static and kicked model is
revealed by calculating corresponding topological invariants defined in the
one-dimensional lattice dimension. Under open boundary conditions along the
physical dimension, Majorana flat bands at energy zero (quasienergy zero and
$\pi$) emerge in the static (kicked) model at the two-dimensional surface
Brillouin zone. For certain values of pairing order parameter, (Floquet)
Su-Schrieffer-Heeger-like edge modes appear in the form of arcs connecting
different (Floquet) Majorana flat bands. Finally, we find that in the kicked
model, it is possible to generate two controllable Floquet Majorana modes, one
at quasienergy zero and the other at quasienergy $\pi$, at the same parameter
values.


title: Relativistic Brueckner-Hartree-Fock theory for finite nuclei

abstract:
  Starting with a bare nucleon-nucleon interaction, for the first time the full
relativistic Brueckner-Hartree-Fock equations are solved for finite nuclei in a
Dirac-Woods-Saxon basis. No free parameters are introduced to calculate the
ground-state properties of finite nuclei. The nucleus $^{16}$O is investigated
as an example. The resulting ground-state properties, such as binding energy
and charge radius, are considerably improved as compared with the
non-relativistic Brueckner-Hartree-Fock results and much closer to the
experimental data. This opens the door for \emph{ab initio} covariant
investigations of heavy nuclei.


title:
Chaperone driven polymer translocation through Nanopore: spatial
  distribution and binding energy

abstract:
  Chaperones are binding proteins which work as a driving force to bias the
biopolymer translocation by binding to it near the pore and preventing its
backsliding. Chaperones may have different spatial distribution. Recently we
show the importance of their spatial distribution in translocation and how it
effects on sequence dependency of the translocation time. Here we focus on
homopolymers and exponential distribution. As a result of the exponential
distribution of chaperones, energy dependency of the translocation time will
changed and one see a minimum in translocation time versus effective energy
curve. The same trend can be seen in scaling exponent of time versus polymer
length, $\beta$ ($T\sim\beta$). Interestingly in some special cases e.g.
chaperones of size $\lambda=6$ and with exponential distribution rate of
$\alpha=5$, the minimum reaches even to amount of less than $1$ ($\beta<1$). We
explain the possibility of this rare result and base on a theoretical
discussion we show that by taking into account the velocity dependency of the
translocation on polymer length, one could truly predict the amount of this
minimum.


title: Scalar field collapse in a conformally flat spacetime

abstract:
  The collapse scenario of a scalar field along with a perfect fluid
distribution is investigated for a conformally flat spacetime. The theorem for
the integrability of an anharmonic oscillator has been utilized. For a pure
power law potential of the form ${\phi}^{n+1}$, it is found that a central
singularity is formed which is covered by an apparent horizon for $n>0$ and
$n<-3$. Some numerical results have also been presented for a combination of
two different powers of $\phi$ in the potential.


title: Asymptotic for optimizers of the fractional Hardy-Sobolev inequality

abstract:
  We consider the optimizers $u$ in the Hardy-Sobolev inequality for the space
$\dot{W}^{s,p}({\mathbb R}^N)$ with order of differentiability $s\in ]0,1[$.
After proving existence through concentration-compactness, we derive the
pointwise asymptotic $u(x)\simeq |x|^{-\frac{N-ps}{p-1}}$ for large $|x|$ and
the summability estimate $u\in \dot{W}^{s,\gamma}({\mathbb R}^N)$ for all
$\gamma>\frac{N(p-1)}{N-s}$. These estimates are optimal in the limit $s\to
1^-$, in which case optimizers are explicitly known.


title:
Revisiting calculation of moments of number of comparisons used by the
  randomized quick sort algorithm

abstract:
  We revisit the method of Kirschenhofer, Prodinger and Tichy to calculate the
moments of comparisons used by the quick sort algorithm. We reemphasize that
this approach helps in calculating these quantities with less computation. We
also point out that as observed by Knuth this method also gives moments for
total path length of a binary search tree built over a random set of n keys.


title:
Spectral multipliers via resolvent type estimates on non-homogeneous
  metric measure spaces

abstract:
  We describe a simple but surprisingly effective technique of obtaining
spectral multiplier results for abstract operators which satisfy the finite
propagation speed property for the corresponding wave equation propagator. We
show that, in this setting, spectral multipliers follow from resolvent type
estimates. The most notable point of the paper is that our approach is very
flexible and can be applied even if the corresponding ambient space does not
satisfy the doubling condition or if the semigroup generated by an operator is
not uniformly bounded. As a corollary we obtain the $L^p$ spectrum independence
for several second order differential operators and recover some known results.
Our examples include the Laplace-Belltrami operator on manifolds with ends and
Schr\"odinger operators with strongly subcritical potentials.


title: Chaining Bounds for Empirical Risk Minimization

abstract:
  This paper extends the standard chaining technique to prove excess risk upper
bounds for empirical risk minimization with random design settings even if the
magnitude of the noise and the estimates is unbounded. The bound applies to
many loss functions besides the squared loss, and scales only with the
sub-Gaussian or subexponential parameters without further statistical
assumptions such as the bounded kurtosis condition over the hypothesis class. A
detailed analysis is provided for slope constrained and penalized linear least
squares regression with a sub-Gaussian setting, which often proves tight sample
complexity bounds up to logartihmic factors.


title: Wigner law for matrices with dependent entries - a perturbative approach

abstract:
  We show that Wigner semi-circle law holds for Hermitian matrices with
dependent entries, provided the deviation of the cumulants from the normalised
Gaussian case obeys a simple power law bound in the size of the matrix. To
establish this result, we use replicas interpreted as a zero-dimensional
quantum field theoretical model whose effective potential obey a
renormalisation group equation.