title:
Superlinearity of geodesic length in 2$D$ critical first-passage
  percolation

abstract:
  First-passage percolation is the study of the metric space
$(\mathbb{Z}^d,T)$, where $T$ is a random metric defined as the weighted graph
metric using random edge-weights $(t_e)_{e\in \mathcal{E}^d}$ assigned to the
nearest-neighbor edges $\mathcal{E}^d$ of the $d$-dimensional cubic lattice. We
study the so-called critical case in two dimensions, in which
$\mathbb{P}(t_e=0)=p_c$, where $p_c$ is the threshold for two-dimensional bond
percolation. In contrast to the standard case $(<p_c)$, the distance $T(0,x)$
in the critical case grows sub linearly in $x$ and geodesics are expected to
have Euclidean length which is superlinear. We show a strong version of this
super linearity, namely that there is $s>1$ such that with probability at least
$1-e^{-\|x\|_1^c}$, the minimal length geodesic from $0$ to $x$ has at least
$\|x\|_1^s$ number of edges. Our proofs combine recent ideas to bound $T$ for
general critical distributions, and modifications of techniques of
Aizenman-Burchard to estimate the Hausdorff dimension of random curves.


title: Integrable nonlocal nonlinear equations

abstract:
  A nonlocal nonlinear Schr\"odinger (NLS) equation was recently found by the
authors and shown to be an integrable infinite dimensional Hamiltonian
equation. Unlike the classical (local) case, here the nonlinearly induced
"potential" is $PT$ symmetric thus the nonlocal NLS equation is also $PT$
symmetric. In this paper, new {\it reverse space-time} and {\it reverse time}
nonlocal nonlinear integrable equations are introduced. They arise from
remarkably simple symmetry reductions of general AKNS scattering problems where
the nonlocality appears in both space and time or time alone. They are
integrable infinite dimensional Hamiltonian dynamical systems. These include
the reverse space-time, and in some cases reverse time, nonlocal nonlinear
Schr\"odinger, modified Korteweg-deVries (mKdV), sine-Gordon, $(1+1)$ and
$(2+1)$ dimensional three-wave interaction, derivative NLS, "loop soliton",
Davey-Stewartson (DS), partially $PT$ symmetric DS and partially reverse
space-time DS equations. Linear Lax pairs, an infinite number of conservation
laws, inverse scattering transforms are discussed and one soliton solutions are
found. Integrable reverse space-time and reverse time nonlocal discrete
nonlinear Schr\"odinger type equations are also introduced along with few
conserved quantities. Finally, nonlocal Painlev\'e type equations are derived
from the reverse space-time and reverse time nonlocal NLS equations.


title: Constraint Control of Nonholonomic Mechanical Systems

abstract:
  We derive an optimal control formulation for a nonholonomic mechanical system
using the nonholonomic constraint itself as the control. We focus on Suslov's
problem, which is defined as the motion of a rigid body with a vanishing
projection of the body frame angular velocity on a given direction
$\boldsymbol{\xi}$. We derive the optimal control formulation, first for an
arbitrary group, and then in the classical realization of Suslov's problem for
the rotation group $SO(3)$. We show that it is possible to control the system
using the constraint $\boldsymbol{\xi}(t)$ and demonstrate numerical examples
in which the system tracks quite complex trajectories such as a spiral.


title: The Discrete Adjoint Method for Exponential Integration

abstract:
  The implementation of the discrete adjoint method for exponential time
differencing (ETD) schemes is considered. This is important for parameter
estimation problems that are constrained by stiff time-dependent PDEs when the
discretized PDE system is solved using an exponential integrator. We also
discuss the closely related topic of computing the action of the sensitivity
matrix on a vector, which is required when performing a sensitivity analysis.
The PDE system is assumed to be semi-linear and can be the result of a
linearization of a nonlinear PDE, leading to exponential Rosenbrock-type
methods. We discuss the computation of the derivatives of the
$\varphi$-functions that are used by ETD schemes and find that the derivatives
strongly depend on the way the $\varphi$-functions are evaluated numerically. A
general adjoint exponential integration method, required when computing the
gradients, is developed and its implementation is illustrated by applying it to
the Krogstad scheme. The applicability of the methods developed here to pattern
formation problems is demonstrated using the Swift-Hohenberg model.


title:
Unveiling the link between fractional Schr\"odinger equation and light
  propagation in honeycomb lattice

abstract:
  We establish a link between the fractional Schr\"odinger equation (FSE) and
light propagation in the honeycomb lattice (HCL) - the Dirac-Weyl equation
(DWE). The fractional Laplacian in FSE causes a modulation of the dispersion
relation of the system, which in the limiting case becomes linear. In the HCL,
the dispersion relation is already linear around the Dirac point, suggesting a
possible connection with the FSE. Here, we demonstrate this connection by
describing light propagation in both FSE and HCL, using DWE. Thus, we propagate
Gaussian beams according to FSE, HCL around the Dirac point, and DWE, to
discover very similar behavior - the conical diffraction. However, if an
additional potential is brought into the system, the link between FSE and HCL
is broken, because the added potential serves as a perturbation, which breaks
the translational periodicity of HCL and destroys Dirac cones in the dispersion
relation.


title: Physical model for turbulent friction on rough surfaces

abstract:
  We present a physical model for turbulent friction on rough surfaces with
regularly distributed roughness elements. Wall shear stresses are expressed as
functions of physical quantities. Surfaces with varying roughness densities and
roughness elements with different aspect ratios are considered. We propose a
straight forward method based on the conservation of momentum to deduce the
drag on elements by expressing it as functions of the maximum drag and drag
reductions ratios, as the drag on individual elements decreases as packing
density increases. A drag reduction effect of momentum redistribution is
proposed and the mutual sheltering effect is studied. These two drag reduction
mechanisms for individual elements are significant for sparse and dense
surfaces, respectively. Reduction ratios for redistribution effect and mutual
sheltering effect are deduced, for the two different types of rough surfaces.
The shear stress on elements and the total wall shear stress are obtained as
the result of the drag analysis. The estimated wall shear stresses of the
proposed model are consistent with classical experimental measurements.


title: The Jacobian ideal of a commutative ring and annihilators of cohomology

abstract:
  It is proved that for a ring $R$ that is either an affine algebra over a
field, or an equicharacteristic complete local ring, some power of the Jacobian
ideal of $R$ annihilates $\mathrm{Ext}^{d+1}_{R}(-,-)$, where $d$ is the Krull
dimension of $R$. Sufficient conditions are identified under which the Jacobian
ideal itself annihilates these Ext-modules, and examples are provided that show
that this is not always the case. A crucial new idea is to consider a derived
version of the Noether different of an algebra.


title:
Relative Morita equivalence of Cuntz--Krieger algebras and flow
  equivalence of topological Markov shifts

abstract:
  In this paper, we will introduce notions of relative version of imprimitivity
bimodules and relative version of strong Morita equivalence for pairs of
$C^*$-algebras $(\mathcal{A}, \mathcal{D})$ such that $\mathcal{D}$ is a
$C^*$-subalgebra of $\mathcal{A}$ with certain conditions. We will then prove
that two pairs $(\mathcal{A}_1, \mathcal{D}_1)$ and $(\mathcal{A}_2,
\mathcal{D}_2)$ are relatively Morita equivalent if and only if their relative
stabilizations are isomorphic. In particularly, for two pairs $(\mathcal{O}_A,
\mathcal{D}_A)$ and $(\mathcal{O}_B, \mathcal{D}_B)$ of Cuntz--Krieger algebras
with their canonical masas, they are relatively Morita equivalent if and only
if their underlying two-sided topological Markov shifts
$(\bar{X}_A,\bar{\sigma}_A)$ and $(\bar{X}_B,\bar{\sigma}_B)$ are flow
equivalent. We also introduce a relative version of the Picard group
${\operatorname{Pic}}(\mathcal{A}, \mathcal{D})$ for the pair $(\mathcal{A},
\mathcal{D})$ of $C^*$-algebras and study them for the Cuntz--Krieger pair
$(\mathcal{O}_A, \mathcal{D}_A)$.


title:
Stellar Velocity Dispersion in Mergers: The Effects of Dust and Star
  Formation

abstract:
  We investigate the effects of stellar evolution and dust on measurements of
stellar velocity dispersion in mergers of disk galaxies. $N$-body simulations
and radiative transfer analysis software are used to obtain mass-weighted and
flux-weighted measurements of stellar velocity dispersion. We find that the
distribution of dust with respect to the distribution of young stars in such
systems is more important than the total degree of attenuation. The presence of
dust typically causes flux-weighted measurements of stellar velocity dispersion
to be elevated with respect to mass-weighted measurements because dust
preferentially obscures young stars, which tend to be dynamically cooler than
older stellar populations in such systems. In exceptional situations, in which
young stars are not preferentially obscured by dust, flux-weighted velocity
dispersion measurements tend to be negatively offset with respect to
mass-weighted measurements because the dynamically cool young stellar
populations are more luminous, per unit mass, than older stellar populations.
Our findings provide a context for comparing observationally-obtained
measurements of velocity dispersion with measurements of velocity dispersion
obtained from galaxy merger simulations.


title: Finite Rank Isopairs

abstract:
  An algebraic isopair is a commuting pair of pure isometries that is
annihilated by a polynomial defining a distinguished variety $\mathcal{V}$. The
notion of the rank of a pure algebraic isopair with finite bimultiplicity is
introduced. For $\mathcal{V} $, a union of $s$ irreducible varieties
$\mathcal{V}_j$, the rank is a $s$-tuple $\alpha=(\alpha_1,...,\alpha_s)$ of
natural numbers. A pure algebraic isopair of finite bimultiplicity with rank
$\alpha$ is described as a restriction of a
$\max\{\alpha_1,...,\alpha_s\}$-cyclic pure algebraic isopair to a finite
codimensional invariant subspace. The restriction of a pure algebraic isopair
of finite bimultiplicity with rank $\alpha$ to a finite codimensional invariant
subspace is at least $\max\{\alpha_1,...,\alpha_s\}$-cyclic and there is a
$\max\{\alpha_1,...,\alpha_s\}$-cyclic finite codimensional invariant subspace.


title:
Existence of a highest wave in a fully dispersive two-way shallow water
  model

abstract:
  We consider the existence of periodic traveling waves in a bidirectional
Whitham equation, combining the full two-way dispersion relation from the
incompressible Euler equations with a canonical shallow water nonlinearity. Of
particular interest is the existence of a highest, cusped, traveling wave
solution, which we obtain as a limiting case at the end of the main bifurcation
branch of $2\pi$-periodic traveling wave solutions continuing from the zero
state. Unlike the unidirectional Whitham equation, containing only one branch
of the full Euler dispersion relation, where such a highest wave behaves like
$|x|^{1/2}$ near its crest, the cusped waves obtained here behave like
$|x\log|x||$. Although the linear operator involved in this equation can be
easily represented in terms of an integral operator, it maps continuous
functions out of the H\"older and Lipschitz scales of function spaces by
introducing logarithmic singularities. Since the nonlinearity is also of higher
order than that of the unidirectional Whitham equation, several parts of our
proofs and results deviate from those of the corresponding unidirectional
equation, with the analysis of the logarithmic singularity being the most
subtle component. This paper is part of a longer research programme for
understanding the interplay between nonlinearities and dispersion in the
formation of large-amplitude waves and their singularities.


title: Relating Chromophoric and Structural Disorder in Conjugated Polymers

abstract:
  The optoelectronic properties of amorphous conjugated polymers are sensitive
to conformational disorder and spectroscopy provides the means for structural
characterization of the fragments of the chain which interact with light -
"chromophores". A faithful interpretation of spectroscopic conformational
signatures, however, presents a key challenge. We investigate the relationship
between the ground state optical gaps, the properties of the excited states,
and the structural features of chromophores of a single molecule
poly(3-hexyl)-thiophene (P3HT), using quantum-classical atomistic simulations.
Our results demonstrate that chromophoric disorder reflects an interplay
between excited state de-localization and electron-hole polarization, and is
controlled by torsional disorder that is specifically associated with the
presence of side chains. Within this conceptual framework, we predict and
explain a counter-intuitive spectral signature of P3HT: a red-shifted
absorption, despite shortening of chromophores, with increasing temperature.


title: Exact time evolution of the asymmetric Hubbard dimer

abstract:
  We examine the time evolution of an asymmetric Hubbard dimer, which has a
different on-site interaction on the two sites. The Hamiltonian has a
time-dependent hopping term, which can be employed to describe an electric
field (which creates a Hamiltonian with complex matrix elements), or it can
describe a modulation of the lattice (which has real matrix elements). By
examining the symmetries under spin and pseudospin, we show that the former
case involves at most a 3 x 3 block---it can be mapped onto the time evolution
of a time-independent Hamiltonian, so the dynamics can be evaluated
analytically and exactly (by solving a nontrivial cubic equation). We also show
that the latter case reduces to at most 2 x 2 blocks, and hence the time
evolution for a single Trotter step can be determined exactly, but the time
evolution generically requires a Trotter product.


title:
Doing Moore with Less -- Leapfrogging Moore's Law with Inexactness for
  Supercomputing

abstract:
  Energy and power consumption are major limitations to continued scaling of
computing systems. Inexactness, where the quality of the solution can be traded
for energy savings, has been proposed as an approach to overcoming those
limitations. In the past, however, inexactness necessitated the need for highly
customized or specialized hardware. The current evolution of commercial
off-the-shelf(COTS) processors facilitates the use of lower-precision
arithmetic in ways that reduce energy consumption. We study these new
opportunities in this paper, using the example of an inexact Newton algorithm
for solving nonlinear equations. Moreover, we have begun developing a set of
techniques we call reinvestment that, paradoxically, use reduced precision to
improve the quality of the computed result: They do so by reinvesting the
energy saved by reduced precision.


title: The External Calibrator for Hydrogen Observatories

abstract:
  Multiple instruments are pursuing constraints on dark energy, observing
reionization and opening a window on the dark ages through the detection and
characterization of the 21cm hydrogen line across the redshift spectrum, from
nearby to z=25. These instruments, including CHIME in the sub-meter and HERA in
the meter bands, are wide-field arrays with multiple-degree beams, typically
operating in transit mode. Accurate knowledge of their primary beams is
critical for separation of bright foregrounds from the desired cosmological
signals, but difficult to achieve through astronomical observations alone.
Previous beam calibration work has focused on model verification and does not
address the need of 21cm experiments for routine beam mapping, to the horizon,
of the as-built array. We describe the design and methodology of a
drone-mounted calibrator, the External Calibrator for Hydrogen Observatories
(ECHO), that aims to address this need. We report on a first set of trials to
calibrate low-frequency dipoles and compare ECHO measurements to an established
beam-mapping system based on transmissions from the Orbcomm satellite
constellation. We create beam maps of two dipoles at a 9-degree resolution and
find sample noise ranging from 1 to 2%. Assuming this sample noise represents
the error in the measurement, the higher end of this range is roughly twice the
desired requirement. The overall performance of ECHO suggests that the desired
precision and angular coverage is achievable in practice with modest
improvements. We identify the main sources of systematic error and uncertainty
in our measurements and describe the steps needed to overcome them.


title: Research and Education in Computational Science and Engineering

abstract:
  Over the past two decades the field of computational science and engineering
(CSE) has penetrated both basic and applied research in academia, industry, and
laboratories to advance discovery, optimize systems, support decision-makers,
and educate the scientific and engineering workforce. Informed by centuries of
theory and experiment, CSE performs computational experiments to answer
questions that neither theory nor experiment alone is equipped to answer. CSE
provides scientists and engineers of all persuasions with algorithmic
inventions and software systems that transcend disciplines and scales. Carried
on a wave of digital technology, CSE brings the power of parallelism to bear on
troves of data. Mathematics-based advanced computing has become a prevalent
means of discovery and innovation in essentially all areas of science,
engineering, technology, and society; and the CSE community is at the core of
this transformation. However, a combination of disruptive
developments---including the architectural complexity of extreme-scale
computing, the data revolution that engulfs the planet, and the specialization
required to follow the applications to new frontiers---is redefining the scope
and reach of the CSE endeavor. This report describes the rapid expansion of CSE
and the challenges to sustaining its bold advances. The report also presents
strategies and directions for CSE research and education for the next decade.


title:
Learning Human-Robot Handovers Through $\pi$-STAM: Policy Improvement
  With Spatio-Temporal Affordance Maps

abstract:
  Human-robot handovers are characterized by high uncertainty and poor
structure of the problem that make them difficult tasks. While machine learning
methods have shown promising results, their application to problems with large
state dimensionality, such as in the case of humanoid robots, is still limited.
Additionally, by using these methods and during the interaction with the human
operator, no guarantees can be obtained on the correct interpretation of
spatial constraints (e.g., from social rules). In this paper, we present Policy
Improvement with Spatio-Temporal Affordance Maps -- $\pi$-STAM, a novel
iterative algorithm to learn spatial affordances and generate robot behaviors.
Our goal consists in generating a policy that adapts to the unknown action
semantics by using affordances. In this way, while learning to perform a
human-robot handover task, we can (1) efficiently generate good policies with
few training episodes, and (2) easily encode action semantics and, if
available, enforce prior knowledge in it. We experimentally validate our
approach both in simulation and on a real NAO robot whose task consists in
taking an object from the hands of a human. The obtained results show that our
algorithm obtains a good policy while reducing the computational load and time
duration of the learning process.


title: Visual Closed-Loop Control for Pouring Liquids

abstract:
  Pouring a specific amount of liquid is a challenging task. In this paper we
develop methods for robots to use visual feedback to perform closed-loop
control for pouring liquids. We propose both a model-based and a model-free
method utilizing deep learning for estimating the volume of liquid in a
container. Our results show that the model-free method is better able to
estimate the volume. We combine this with a simple PID controller to pour
specific amounts of liquid, and show that the robot is able to achieve an
average 38ml deviation from the target amount. To our knowledge, this is the
first use of raw visual feedback to pour liquids in robotics.


title: On the zeros of random harmonic polynomials: the naive model

abstract:
  A complex harmonic polynomial is the sum of a complex polynomial and a
conjugated complex polynomial, of degrees $n$ and $m$ respectively. Li and Wei
(2009) presented a formula for the expected number of zeros of a random
harmonic polynomial in $\mathbb{C}$. In this paper we prove that if $m$ is a
fixed number, this expectation is asymptotically $n$ as $n\rightarrow\infty$,
and if $m=n$ we find a lower and upper bound of order $n\log n$ for this
expectation for sufficiently large $n$.


title: Generalized Boltzmann Distribution for Systems out of Equilibrium

abstract:
  The Boltzmann distribution predicts the collective behavior of systems at
thermodynamic equilibrium as a function of their constituent parts. Yet most
systems in nature are not at equilibrium, and a unified theory of their
behavior does not currently exist. Here, I show that the Boltzmann distribution
is a special case of a general distribution that governs all stochastic
systems, even if far from equilibrium. The generalized Boltzmann distribution
is explained as an analog of the voltage equation in electronics, where
resistors, batteries, node voltages, and path currents correspond to
equilibrium rate constants, driven rate constants, probabilities, and
probability flows, respectively. The general distribution recapitulates known
properties of weakly driven systems and enables new closed-form solutions for
strongly-driven systems. These solutions provide insight into fundamental
limits on system performance, and experimental data show that living systems
can operate at those limits. The formal mapping between non-equilibrium systems
and electronic circuits may provide a unified framework to simplify,
understand, and ultimately control the behavior of complex non-equilibrium
systems.


title:
Theoretical description of pump/probe experiments in electron mediated
  charge-density-wave insulators

abstract:
  In this review, we develop the formalism employed to describe
charge-density-wave insulators in pump/probe experiments using ultra short
driving pulses of light. The theory emphasizes exact results in the simplest
model for a charge-density wave insulator (given by a noninteracting systems
with two bands and a gap) and by employing nonequilibrium dynamical mean-field
theory to solve the Falicov-Kimball model in its ordered phase. We show both
how to develop the formalism and how the solutions behave. Care is taken to
describe the details behind these calculations and to show how to verify their
accuracy via sum-rule constraints.


title: Tunneling Dynamics Between Atomic Bright Solitons

abstract:
  We investigate tunneling behavior between two bright solitons in a
Bose-Einstein condensate with attractive contact interactions between atoms.
The explicit tunneling properties including tunneling particles and oscillation
period are described analytically, which indicates that the periodic tunneling
form is a nonlinear Josephson type oscillation. The results suggest that the
breathing behavior of solitons comes from the tunneling mechanism in an
effective double-well potential, which is quite different from the modulational
instability mechanism for Akhmediev breather and K-M breather. Furthermore, we
obtain a phase diagram for two soliton interaction which admits tunneling
property, particle-like property, interference property, and a resonant
interaction case. The explicit conditions for them are clarified based on the
defined critical distance $d_c$ and spatial interference period $D$.


title: A note on homological properties of Nakayama algebras

abstract:
  Using the resolution quiver for a connected Nakayama algebra, a fast
algorithm is given to decide whether its global dimension is finite or not and
whether it is Gorenstein or not. The latter strengthens a result of Ringel.


title:
Learning Spatial-Semantic Context with Fully Convolutional Recurrent
  Network for Online Handwritten Chinese Text Recognition

abstract:
  Online handwritten Chinese text recognition (OHCTR) is a challenging problem
as it involves a large-scale character set, ambiguous segmentation, and
variable-length input sequences. In this paper, we exploit the outstanding
capability of path signature to translate online pen-tip trajectories into
informative signature feature maps using a sliding window-based method,
successfully capturing the analytic and geometric properties of pen strokes
with strong local invariance and robustness. A multi-spatial-context fully
convolutional recurrent network (MCFCRN) is proposed to exploit the multiple
spatial contexts from the signature feature maps and generate a prediction
sequence while completely avoiding the difficult segmentation problem.
Furthermore, an implicit language model is developed to make predictions based
on semantic context within a predicting feature sequence, providing a new
perspective for incorporating lexicon constraints and prior knowledge about a
certain language in the recognition procedure. Experiments on two standard
benchmarks, Dataset-CASIA and Dataset-ICDAR, yielded outstanding results, with
correct rates of 97.10% and 97.15%, respectively, which are significantly
better than the best result reported thus far in the literature.


title:
Time-Average Optimization with Non-Convex Decision Set and Its
  Convergence

abstract:
  This paper considers time-average optimization, where a decision vector is
chosen every time step within a (possibly non-convex) set, and the goal is to
minimize a convex function of the time averages subject to convex constraints
on these averages. Such problems have applications in networking, multi-agent
systems, and operations research, where decisions are constrained to a discrete
set and the decision average can represent average bit rates or average agent
actions. This time-average optimization extends traditional convex formulations
to allow a non-convex decision set. This class of problems can be solved by
Lyapunov optimization. A simple drift-based algorithm, related to a classical
dual subgradient algorithm, converges to an $\epsilon$-optimal solution within
$O(1/\epsilon^2)$ time steps. Further, the algorithm is shown to have a
transient phase and a steady state phase which can be exploited to improve
convergence rates to $O(1/\epsilon)$ and $O(1/{\epsilon^{1.5}})$ when vectors
of Lagrange multipliers satisfy locally-polyhedral and locally-smooth
assumptions respectively. Practically, this improved convergence suggests that
decisions should be implemented after the transient period.


title: Collider Phenomenology of $e^{-}e^{-}\to W^{-}W^{-}$

abstract:
  Whether in nature exists Majorana neutrino is one of the most fundamental
questions in physics. It is directly related to the violation of accidental
$U(1)$-lepton number symmetry(LNV). Enormous efforts had been put into such
test and among them, one conventional experiment is the neutrinoless
double-beta decay ($0\nu\beta\beta$). On the other hand, there have been
proposals of future electron-positron colliders such as International Linear
Collider (ILC) for precision measurements of Higgs boson or new discovered
beyond SM particles and it can potentially be converted into an
electron-electron collider. Such collider enables a new probe of Majorana
neutrino via the inverse $0\nu\beta\beta$ process($e^{-}e^{-}\to W^- W^-$) as
an alternative and complementary test to the conventional neutrinoless
double-beta decay experiments. In this paper, we illustrate the searching
strategies of $e^{-}e^{-}\to W^- W^-$ at future electron colliders, and find
that the channels of pure hadronic, semi-leptonic with muon and pure leptonic
with muons have the most discovery potential.


title: Skeletal Geometric Complexes and Their Symmetries

abstract:
  Skeletal polyhedra and polygonal complexes are finite or infinite periodic
structures in 3-space with interesting geometric, combinatorial, and algebraic
properties. These structures can be viewed as finite or infinite periodic
graphs (nets) equipped with a polyhedral superstructure imposed by the faces,
allowed to be skew, zigzag, or helical. The article describes skeletal
structures with maximal symmetry.


title:
Reconstruction of signals from their autocorrelation and
  cross-correlation vectors, with applications to phase retrieval and blind
  channel estimation

abstract:
  We consider the problem of reconstructing two signals from the
autocorrelation and cross-correlation measurements. This inverse problem is a
fundamental one in signal processing, and arises in many applications,
including phase retrieval and blind channel estimation. In a typical phase
retrieval setup, only the autocorrelation measurements are obtainable. We show
that, when the measurements are obtained using three simple "masks", phase
retrieval reduces to the aforementioned reconstruction problem.
  The classic solution to this problem is based on finding common factors
between the $z$-transforms of the autocorrelation and cross-correlation
vectors. This solution has enjoyed limited practical success, mainly due to the
fact that it is not sufficiently stable in the noisy setting. In this work,
inspired by the success of convex programming in provably and stably solving
various quadratic constrained problems, we develop a semidefinite
programming-based algorithm and provide theoretical guarantees. In particular,
we show that almost all signals can be uniquely recovered by this algorithm (up
to a global phase). Comparative numerical studies demonstrate that the proposed
method significantly outperforms the classic method in the noisy setting.


title: Tilting modules of affine quasi-hereditary algebras

abstract:
  We discuss tilting modules of affine quasi-hereditary algebras. We present an
existence theorem of indecomposable tilting modules when the algebra has a
large center and use it to deduce a criterion for an exact functor between two
affine highest weight categories to give an equivalence. As an application, we
prove that the Arakawa-Suzuki functor [Arakawa-Suzuki, J. of Alg. 209 (1998)]
gives a fully faithful embedding of a block of the deformed BGG category of
$\mathfrak{gl}_{m}$ into the module category of a suitable completion of
degenerate affine Hecke algebra of $GL_{n}$.


title:
Hamilton-Souplet-Zhang type gradient estimates for porous medium type
  equations on Riemannian manifolds

abstract:
  In this paper, by employ the cutoff function and the maximum principle, some
Hamilton-Souplet-Zhang type gradient estimates for porous medium type equation
are deduced. As a special case, an Hamilton-Souplet-Zhang type gradient
estimates of the heat equation is derived which is different from the result of
Souplet-Zhang.
  Furthermore, our results generalize those of Zhu. As application, some
Livillous theorems for ancient solution are derived.


title: Singularity-free Numerical Scheme for the Stationary Wigner Equation

abstract:
  For the stationary Wigner equation with inflow boundary conditions, its
numerical convergence with respect to the velocity mesh size are deteriorated
due to the singularity at velocity zero. In this paper, using the fact that the
solution of the stationary Wigner equation is subject to an algebraic
constraint, we prove that the Wigner equation can be written into a form with a
bounded operator $\mathcal{B}[V]$, which is equivalent to the operator
$\mathcal{A}[V]=\Theta[V]/v$ in the original Wigner equation under some
conditions. Then the discrete operators discretizing $\mathcal{B}[V]$ are
proved to be uniformly bounded with respect to the mesh size. Based on the
therectical findings, a signularity-free numerical method is proposed.
Numerical reuslts are proivded to show our improved numerical scheme performs
much better in numerical convergence than the original scheme based on
discretizing $\mathcal{A}[V]$.


title: Beam halo study on ATF damping ring

abstract:
  Halo distribution is a key topic for background study. This paper has
developed an analytical method to give an estimation of ATF beam halo
distribution. The equilibrium particle distribution of the beam tail in the ATF
damping ring is calculated analytically with different emittance and different
vacuum degree. The analytical results agree the measurements very well. This is
a general method which can be applied to any electron rings.


title:
Constant Matrix Element Approximation to Time-Resolved Angle-Resolved
  Photoemission Spectroscopy

abstract:
  We describe different approximations associated with employing a constant
matrix element for the coupling of light to multiband electrons in the context
of time-resolved angle-resolved photoemission spectroscopy (TR-ARPES). In
particular, we demonstrate that the constant matrix approximation only holds
for one of the coordinate representations, and changing to other bases,
requires including nonconstant corrections to the matrix element. We also
discuss some simplifying approximations, where a constant matrix element is
employed in multiple bases, and the consequences of this further approximation
(especially with respect to the TR-ARPES signal no longer being nonnegative).
We also discuss issues related to gauge invariance of the final spectra.


title:
Eccentricity and Spin-Orbit Misalignment in Short-Period Stellar
  Binaries as a Signpost of Hidden Tertiary Companions

abstract:
  Eclipsing binaries are observed to have a range of eccentricities and
spin-orbit misalignments (stellar obliquities). Whether such properties are
primordial, or arise from post-formation dynamical interactions remains
uncertain. This paper considers the scenario in which the binary is the inner
component of a hierarchical triple stellar system, and derives the requirements
that the tertiary companion must satisfy in order to raise the eccentricity and
obliquity of the inner binary. Through numerical integrations of the secular
octupole-order equations of motion of stellar triples, coupled with the spin
precession of the oblate primary star due to the torque from the secondary, we
obtain a simple, robust condition for producing spin-orbit misalignment in the
inner binary: In order to excite appreciable obliquity, the precession rate of
the stellar spin axis must be smaller than the orbital precession rate due to
the tertiary companion. This yields quantitative requirements on the mass and
orbit of the tertiary. We also present new analytic expressions for the maximum
eccentricity and range of inclinations allowing eccentricity excitation
(Lidov-Kozai window), for stellar triples with arbitrary masses and including
the non-Keplerian potentials introduced by general relativity, stellar tides
and rotational bulges. The results of this paper can be used to place
constraints on unobserved tertiary companions in binaries that exhibit high
eccentricity and/or spin-orbit misalignment, and will be helpful in guiding
efforts to detect external companions around stellar binaries. As an
application, we consider the eclipsing binary DI Herculis, and identify the
requirements that a tertiary companion must satisfy to produce the observed
spin-orbit misalignment.


title: Learning Deep Generative Spatial Models for Mobile Robots

abstract:
  We propose a new probabilistic framework that allows mobile robots to
autonomously learn deep, generative models of their environments that span
multiple levels of abstraction. Unlike traditional approaches that combine
engineered models for low-level features, geometry, and semantics, our approach
leverages recent advances in Sum-Product Networks (SPNs) and deep learning to
learn a single, universal model of the robot's spatial environment. Our model
is fully probabilistic and generative, and represents a joint distribution over
spatial information ranging from low-level geometry to semantic
interpretations. Once learned, it is capable of solving a wide range of tasks:
from semantic classification of places, uncertainty estimation, and novelty
detection, to generation of place appearances based on semantic information and
prediction of missing data in partial observations. Experiments on laser-range
data from a mobile robot show that the proposed universal model obtains
performance superior to state-of-the-art models fine-tuned to one specific
task, such as Generative Adversarial Networks (GANs) or SVMs.


title:
Generating Isolated Terawatt-Attosecond X-ray Pulses via a Chirped Laser
  Enhanced High-Gain Free-electron Laser

abstract:
  A feasible method is proposed to generate isolated attosecond terawatt x-ray
radiation pulses in high-gain free-electron lasers. In the proposed scheme, a
frequency chirped laser pulse is employed to generate a gradually-varied
spacing current enhancement of the electron beam and a series of spatiotemporal
shifters are applied between the undulator sections to amplify a chosen
ultra-short radiation pulse from self-amplified spontaneous emission.
Three-dimensional start-to-end simulations have been carried out and the
calculation results demonstrated that 0.15 nm x-ray pulses with peak power over
1TW and duration of several tens of attoseconds could be achieved by using the
proposed technique.


title:
Three Lectures of Flavor and CP violation within and Beyond the Standard
  Model

abstract:
  These notes are based on the lectures I gave at the 2015 European School of
High-Energy Physics (ESHEP2015). I discuss 1) flavor physics within the
Standard Model, 2) effective field theories and Minimal Flavor Violation, 3)
flavor physics in theories beyond the Standard Model and "high energy" flavor
transitions of the top quark and of the Higgs boson. As a bi-product, I present
the most updated constraints from the measurements of B_s -> mu^+mu^-, as well
as I discuss the most recent development in the LHC searches for top flavor
changing couplings.


title:
Direct Meissner Effect Observation of Superconductivity in Compressed
  H2S

abstract:
  Recently, an extremely high superconducting temperature (Tc) of ~200 K has
been reported in the sulfur hydride system above 100 GPa. This result is
supported by theoretical predictions and verified experimentally. The crystal
structure of the superconducting phase was also identified experimentally,
confirming the theoretically predicted structure as well as a decomposition
mechanism from H2S to H3S+S. Even though nuclear resonant scattering has been
successfully used to provide magnetic evidence for a superconducting state, a
direct measurement of the important Meissner effect is still lacking. Here we
report in situ alternating-current magnetic susceptibility measurements on
compressed H2S under high pressures. It is shown that superconductivity
suddenly appears at 117 GPa and that Tc reaches 183 K at 149 GPa before
decreasing monotonically with a further increase in pressure. This evolution
agrees with both theoretical calculations and earlier experimental
measurements. The idea of conventional high temperature superconductivity in
hydrogen-dominant compounds has thus been realized in the sulfur hydride system
under hydrostatic pressure, opening further exciting perspectives for possibly
realizing room temperature superconductivity in hydrogen-based compounds.


title:
Vortex oscillations around a hemisphere-cylinder body with a high
  fineness ratio

abstract:
  The vortex unsteadiness around a hemisphere-cylinder body at AOAs of 10 to 80
deg was studied using Large Eddy Simulation (LES) and Dynamic Mode
Decomposition (DMD). The Reynolds number (Re) based on the cylinder diameter of
the body is 22000. The results show that vortex oscillations exist over the
forebody at the whole range of AOAs. The oscillation is characterized by
alternate oscillations of a forebody leeward vortex pair up and down and
in-phase swings from side to side. The vortex shedding can be found at the
afterbody as AOAs more than 20o, and the shedding region moves forwards
gradually with AOAs increasing, and accordingly the region of vortex
oscillations contracts and eventually only exists near the nose as AOAs
sufficiently high. The vortex oscillation and shedding all induce fluctuating
side forces along the body, but the ones from vortex oscillations are larger.
The frequencies of vortex oscillations are similar to the ones of vortex
shedding at the AOAs of 10o-40o with St=0.085-0.12, in which the flow fields
over the afterbody are dominated by vortex shedding and forebody-vortex wakes
together; while at AOAs of 50o-80o, the frequencies along the body are
apparently divided into two regimes in which the vortex oscillations over the
forebody have the frequencies of 0.053-0.064, and the vortex shedding over the
afterbody has the frequencies of 0.16-0.2. The DMD analysis shows that except
the mean flows, the most energetic modes correspond to the vortex oscillation
at the forebody and to the vortex shedding at the afterbody respectively, and
the frequencies from DMD are identical to the ones of the side forces obtained
by fast Fourier transform. The time-averaged flow fields for the vortex
oscillations are symmetric, and no apparent asymmetry exists. Therefore, the
vortex pair over the forebody oscillates around a symmetric mean flow field.


title:
Planetary model of sunspot emergence: A spectral and autocorrelation
  analysis

abstract:
  This paper is concerned with intermediate range periodicity in the sunspot
area spectrum. An empirical model of sunspot area emergence based on Mercury
planet conjunctions was developed and the spectra of the model variation and
the sunspot area variation compared. By including solar cycle amplitude
modulation and the effect of solar magnetic field reversal the model was able
to predict fine detail in the sunspot area spectrum. As Mercury planet
conjunctions occur predictably it was possible to compare the time variation of
band limited components of sunspot area with the corresponding component
variations in the model. When the model component variation was stable
corresponding components of sunspot area lagged the model variation by a few
tens of days. When a 180 degree phase change occurred in the model variation
the corresponding component of sunspot area followed the change over an
interval of a few hundred days, first by decreasing to zero and then emerging
in phase with the model variation. Where periodicities in sunspot area did not
match periods of Fourier components of the model the autocorrelation function
of the model variation provided an indirect numerical link to these
periodicities. Included in these indirect periodicities were components at
periods of about 138, 235, 355, 472, 530, 605, 833, 1190 and 2020 days. Direct
periodicities in the model, those linked directly to Fourier components of
sunspot area, included components at about 88, 116, 176, 200, 292 and 405 days.
The model was developed without allowing for a variable threshold for sunspot
emergence. However, it was found that with a variable threshold above which the
model variation is effective in triggering sunspots, weak Fourier components at
the indirect periods were generated. The model with threshold then encompasses
all of the significant intermediate range periodicities in sunspot area.


title: Enabling Medical Translation for Low-Resource Languages

abstract:
  We present research towards bridging the language gap between migrant workers
in Qatar and medical staff. In particular, we present the first steps towards
the development of a real-world Hindi-English machine translation system for
doctor-patient communication. As this is a low-resource language pair,
especially for speech and for the medical domain, our initial focus has been on
gathering suitable training data from various sources. We applied a variety of
methods ranging from fully automatic extraction from the Web to manual
annotation of test data. Moreover, we developed a method for automatically
augmenting the training data with synthetically generated variants, which
yielded a very sizable improvement of more than 3 BLEU points absolute.


title: On Deductive Systems of AC Semantics for Rough Sets

abstract:
  Antichain based semantics for general rough sets were introduced recently by
the present author. In her paper two different semantics, one for general rough
sets and another for general approximation spaces over quasi-equivalence
relations, were developed. These semantics are improved and studied further
from a lateral algebraic logic perspective in this research. The main results
concern the structure of the algebras and deductive systems in the context.


title:
$KMR$ $k_t$-factorization procedure for the description of the $LHCb$
  forward hadron-hadron $Z^0$ production at $\sqrt{s}=13\;TeV$

abstract:
  Quit recently, two sets of new experimental data from the $LHCb$ and the
$CMS$ collaborations have been published, concerning the production of the
$Z^0$ vector boson in hadron-hadron collisions with the center-of-mass energy
$E_{CM}= \sqrt{s}=13\;TeV$. On the other hand, in our recent work, we have
conducted a set of $NLO$ calculations for the production of the electroweak
gauge vector bosons, utilizing the unintegrated parton distribution functions
($UPDF$) in the frameworks of $Kimber$-$Martin$-$Ryskin$ ($KMR$) or
$Martin$-$Ryskin$-$Watt$ ($MRW$) and the $k_t$-factorization formalism,
concluding that the results of the $KMR$ scheme are arguably better in
describing the existing experimental data, coming from $D0$, $CDF$, $CMS$ and
$ATLAS$ collaborations. In the present work, we intend to follow the same $NLO$
formalism and calculate the rate of the production of the $Z^0$ vector boson,
utilizing the $UPDF$ of $KMR$ within the dynamics of the recent data. It will
be shown that our results are in good agreement with the new measurements of
the $LHCb$ and the $CMS$ collaborations.


title: Construction of Regular Black Holes in General Relativity

abstract:
  We present a general procedure for constructing exact black hole solutions
with electric or magnetic charges in General Relativity coupled to a nonlinear
electrodynamics. We obtain a variety of two-parameter family spherically
symmetric black hole solutions. In particular, the singularity at the central
of the space-time can be cancelled in the parameters space and the black hole
solutions become regular everywhere in the space-time. We study the global
properties of the solutions and derive the first law of thermodynamics. We also
generalize the procedure to include a cosmological constant and construct
regular black hole solutions that are asymptotic to anti-de Sitter space-time.


title: Two- and Multi-phase Quadrature Surfaces

abstract:
  In this paper we shall initiate the study of the two- and multi-phase
quadrature surfaces (QS), which amounts to a two/multi-phase free boundary
problems of Bernoulli type. The problem is studied mostly from a potential
theoretic point of view that (for two-phase case) relates to integral
representation $$ \int_{\partial \Omega^+} g h (x) \ d\sigma_x - \int_{\partial
\Omega^-} g h (x) \ d\sigma_x= \int h d\mu \ , $$ where $d\sigma_x$ is the
surface measure, $\mu= \mu^+ - \mu^-$ is given measure with support in (a
priori unknown domain) $\Omega$, $g$ is a given smooth positive function, and
the integral holds for all functions $h$, which are harmonic on $\overline
\Omega$. Our approach is based on minimization of the corresponding two- and
multi-phase functional and the use of its one-phase version as a barrier. We
prove several results concerning existence, qualitative behavior, and
regularity theory for solutions. A central result in our study states that
three or more junction points do not appear.


title:
A higher rank Racah algebra and the $\mathbb{Z}_2^{n}$ Laplace-Dunkl
  operator

abstract:
  A higher rank generalization of the (rank one) Racah algebra is obtained as
the symmetry algebra of the Laplace-Dunkl operator associated to the
$\mathbb{Z}_2^n$ root system. This algebra is also the invariance algebra of
the generic superintegrable model on the $n$-sphere. Bases of Dunkl harmonics
are constructed explicitly using a Cauchy-Kovalevskaia theorem. These bases
consist of joint eigenfunctions of maximal Abelian subalgebras of the higher
rank Racah algebra. A method to obtain expressions for both the connection
coefficients between these bases and the action of the symmetries on these
bases is presented.


title: Recent Developments in Neutrino-Nucleus Scattering (Theory)

abstract:
  Selected theoretical developments in neutrino-nucleus scattering in 2015-2016
are reviewed.


title: Lusztig data of Kashiwara-Nakashima tableaux in types $B$ and $C$

abstract:
  We provide an explicit combinatorial description of the embedding of the
crystal of Kashiwara-Nakashima tableaux in types $B$ and $C$ into that of
$\bi$-Lusztig data associated to a family of reduced expressions $\bi$ of the
longest element $w_0$. The description of the embedding is simple and
elementary using only the Sch\"{u}tzenberger's jeu de taquin and RSK algorithm.
A spinor model for classical crystals plays an important role as an
intermediate object connecting Kashiwara-Nakashima tableaux and Lusztig data.


title:
On the dimension of Furstenberg measure for $SL_2(R)$ random matrix
  products

abstract:
  Let $\mu$ be a measure on $SL_{2}(\mathbb{R})$ generating a non-compact and
totally irreducible subgroup, let $\chi>0$ denote its Lyapunov exponent, and
let $\nu$ be the associated stationary (Furstenberg) measure for the action on
the projective line. We prove that if $\mu$ is supported on finitely many
matrices with algebraic entries, then \[
\dim\nu=\min\{1,\frac{h_{\textrm{RW}}(\mu)}{2\chi}\} \] where
$h_{\textrm{RW}}(\mu)$ is the random walk entropy of $\mu$, and $\dim$ denotes
pointwise dimension. In particular, for every $\delta>0$, there is a
neighborhood $U$ of the identity in $SL_{2}(\mathbb{R})$ such that if a measure
$\mu\in\mathcal{P}(U)$ is supported on algebraic matrices with all atoms of
size at least $\delta$, and generates a group which is non-compact and totally
irreducible, then its stationary measure $\nu$ satisfies $\dim\nu=1$.


title: Left-right model for dark matter

abstract:
  We argue that dark matter can automatically arise from a gauge theory that
possesses a non-minimal left-right gauge symmetry, SU(3)_C \otimes SU(M)_L
\otimes SU(N)_R \otimes U(1)_X, for (M,N) = (2,3), (3,2), (3,3), \cdots, and
(5,5).


title: A model independent safeguard for unbinned Likelihood

abstract:
  We present a universal method to include residual un-modeled background shape
uncertainties in likelihood based statistical tests for high energy physics and
astroparticle physics. This approach provides a simple and natural protection
against mismodeling, thus lowering the chances of a false discovery or of an
over constrained confidence interval, and allows a natural transition to
unbinned space. Unbinned likelihood allows optimal usage of information for the
data and the models, and enhances the sensitivity.
  We show that the asymptotic behavior of the test statistic can be regained in
cases where the model fails to describe the true background behavior, and
present 1D and 2D case studies for model-driven and data-driven background
models. The resulting penalty on sensitivities follows the actual discrepancy
between the data and the models, and is asymptotically reduced to zero with
increasing knowledge.


title: Quenching of Satellite Galaxies at the Outskirts of Galaxy Clusters

abstract:
  We find, using cosmological simulations of galaxy clusters, that the hot
X-ray emitting intra-cluster medium (ICM) enclosed within the outer accretion
shock extends out to $R_{\rm shock}\sim(2 - 3) R_{\rm vir}$, where $R_{\rm
vir}$ is the standard virial radius of the halo. Using a simple analytic model
for satellite galaxies in the cluster, we evaluate the effect of ram pressure
stripping on the gas in the inner discs and in the haloes at different
distances from the cluster centre. We find that significant removal of
star-forming disc gas occurs only at $r \lesssim 0.5 R_{\rm vir}$, while gas
removal from the satellite halo is more effective and can occur when the
satellite is found between $ R_{\rm vir}$ and $R_{\rm shock}$. Removal of halo
gas sets the stage for quenching of the star formation by starvation over
$2\textrm{--}3\,\mathrm{Gyr}$, prior to the satellite entry to the inner
cluster halo. This scenario explains the presence of quenched galaxies,
preferentially discs, at the outskirts of galaxy clusters, and the delayed
quenching of satellites compared to central galaxies.


title: On $L$-packets and depth for $SL_2(K)$ and its inner form

abstract:
  We consider the group $SL_2(K)$, where $K$ is a local non-archimedean field
of characteristic two. We prove that the depth of any irreducible
representation of $SL_2 (K)$ is larger than the depth of the corresponding
Langlands parameter, with equality if and only if the L-parameter is
essentially tame.
  We also work out a classification of all $L$-packets for $SL_2 (K)$ and for
its non-split inner form, and we provide explicit formulae for the depths of
their $L$-parameters.


title:
Coprimeness-preserving non-integrable extension to the two-dimensional
  discrete Toda lattice equation

abstract:
  We introduce a so-called `coprimeness-preserving non-integrable' extension
(another terminology is `quasi-integrable' extension) to the two-dimensional
Toda lattice equation. We believe that this equation is the first example of
such discrete equation defined over a three-dimensional lattice. We prove that
all the iterates of the equation are irreducible Laurent polynomials of the
initial data and that every pair of two iterates is co-prime, which indicate
confined singularities of the equation. By reducing the equation to two- or
one-dimensional lattices, we obtain coprimeness-preserving non-integrable
extensions to the one-dimensional Toda lattice equation and the Somos-4
recurrence.


title: No Percolation in low temperature spin glass

abstract:
  We consider the Edwards-Anderson Ising Spin Glass model for non negative
temperatures T: We define the natural notion of Boltzmann- Gibbs measure for
the Edwards-Anderson spin glass at a given temperature, and of unsatisfied
edges. We prove that for low enough temperatures, in almost every spin
configuration the graph formed by the unsatisfied edges is made of finite
connected components. In other words, the unsatisfied edges do not percolate.


title:
Multi-wavelength observations of IGR J17544-2619 from quiescence to
  outburst

abstract:
  In this paper we report on a long multi-wavelength observational campaign of
the supergiant fast X-ray transient prototype IGR J17544-2619. A 150 ks-long
observation was carried out simultaneously with XMM-Newton and NuSTAR, catching
the source in an initial faint X-ray state and then undergoing a bright X-ray
outburst lasting about 7 ks. We studied the spectral variability during
outburst and quiescence by using a thermal and bulk Comptonization model that
is typically adopted to describe the X-ray spectral energy distribution of
young pulsars in high mass X-ray binaries. Although the statistics of the
collected X-ray data were relatively high we could neither confirm the presence
of a cyclotron line in the broad-band spectrum of the source (0.5-40 keV), nor
detect any of the previously reported tentative detection of the source spin
period. The monitoring carried out with Swift/XRT during the same orbit of the
system observed by XMM-Newton and NuSTAR revealed that the source remained in a
low emission state for most of the time, in agreement with the known property
of all supergiant fast X-ray transients being significantly sub-luminous
compared to other supergiant X-ray binaries. Optical and infrared observations
were carried out for a total of a few thousands of seconds during the
quiescence state of the source detected by XMM-Newton and NuSTAR. The measured
optical and infrared magnitudes were slightly lower than previous values
reported in the literature, but compatible with the known micro-variability of
supergiant stars. UV observations obtained with the UVOT telescope on-board
Swift did not reveal significant changes in the magnitude of the source in this
energy domain compared to previously reported values.


title:
A new selection strategy for selective cluster ensemble based on
  Diversity and Independency

abstract:
  This research introduces a new strategy in cluster ensemble selection by
using Independency and Diversity metrics. In recent years, Diversity and
Quality, which are two metrics in evaluation procedure, have been used for
selecting basic clustering results in the cluster ensemble selection. Although
quality can improve the final results in cluster ensemble, it cannot control
the procedures of generating basic results, which causes a gap in prediction of
the generated basic results' accuracy. Instead of quality, this paper
introduces Independency as a supplementary method to be used in conjunction
with Diversity. Therefore, this paper uses a heuristic metric, which is based
on the procedure of converting code to graph in Software Testing, in order to
calculate the Independency of two basic clustering algorithms. Moreover, a new
modeling language, which we called as "Clustering Algorithms Independency
Language" (CAIL), is introduced in order to generate graphs which depict
Independency of algorithms. Also, Uniformity, which is a new similarity metric,
has been introduced for evaluating the diversity of basic results. As a
credential, our experimental results on varied different standard data sets
show that the proposed framework improves the accuracy of final results
dramatically in comparison with other cluster ensemble methods.


title:
Strongly scale-dependent CMB dipolar asymmetry from super-curvature
  fluctuations

abstract:
  We reconsider the observed CMB dipolar asymmetry in the context of open
inflation, where a supercurvature mode might survive the bubble nucleation. If
such a supercurvature mode modulates the amplitude of the curvature power
spectrum, it would easily produce an asymmetry in the power spectrum. We show
that current observational data can be accommodated in a three-field model,
with simple quadratic potentials and a non-trivial field-space metric. Despite
the presence of three fields, we believe this model is so far the simplest that
can match current observations. We are able to match the observed strong scale
dependence of the dipolar asymmetry, without a fine tuning of initial
conditions, breaking slow roll or adding a feature to the evolution of any
field.


title: Zero Shot Hashing

abstract:
  This paper provides a framework to hash images containing instances of
unknown object classes. In many object recognition problems, we might have
access to huge amount of data. It may so happen that even this huge data
doesn't cover the objects belonging to classes that we see in our day to day
life. Zero shot learning exploits auxiliary information (also called as
signatures) in order to predict the labels corresponding to unknown classes. In
this work, we attempt to generate the hash codes for images belonging to unseen
classes, information of which is available only through the textual corpus. We
formulate this as an unsupervised hashing formulation as the exact labels are
not available for the instances of unseen classes. We show that the proposed
solution is able to generate hash codes which can predict labels corresponding
to unseen classes with appreciably good precision.


title: Finding dominant transition pathways via global optimization of action

abstract:
  We present a new computational approach, Action-CSA, to sample multiple
reaction pathways with fixed initial and final states through global
optimization of the Onsager-Machlup action using the conformational space
annealing method. This approach successfully samples not only the most dominant
pathway but also many other possible paths without initial guesses on reaction
pathways. Pathway space is efficiently sampled by crossover operations of a set
of paths and preserving the diversity of sampled pathways. The sampling ability
of the approach is assessed by finding pathways for the conformational changes
of alanine dipeptide and hexane. The benchmarks demonstrate that the rank order
and the transition time distribution of multiple pathways identified by the new
approach are in good agreement with those of long molecular dynamics
simulations. We also show that the lowest action folding pathway of the
mini-protein FSD-1 identified by the new approach is consistent with previous
molecular dynamics simulations and experiments.


title: Lasso-based forecast combinations for forecasting realized variances

abstract:
  Volatility forecasts are key inputs in financial analysis. While lasso based
forecasts have shown to perform well in many applications, their use to obtain
volatility forecasts has not yet received much attention in the literature.
Lasso estimators produce parsimonious forecast models. Our forecast combination
approach hedges against the risk of selecting a wrong degree of model
parsimony. Apart from the standard lasso, we consider several lasso extensions
that account for the dynamic nature of the forecast model. We apply forecast
combined lasso estimators in a comprehensive forecasting exercise using
realized variance time series of ten major international stock market indices.
We find the lasso extended "ordered lasso" to give the most accurate realized
variance forecasts. Multivariate forecast models, accounting for volatility
spillovers between different stock markets, outperform univariate forecast
models for longer forecast horizons.


title:
Nonlinear optical properties of undoped and doped with Zr and Nb KTiOPO4
  crystals

abstract:
  The structure of the ferroelectric phase of undoped KTiOPO$_4$ and its solid
solutions with zirconium and niobium is studied from first principles within
the density functional theory. The second-order nonlinear susceptibility tensor
and the spontaneous polarization of these materials are obtained. It is shown
that an improvement in nonlinear optical properties of KTiOPO$_4$ upon its
doping with Zr and Nb cannot be explained by a systematic change in the
composition of crystals and is apparently associated with the occurrence of
defects. Possible structures of such defects are discussed.


title:
Higher iterated Hilbert coefficients of the graded components of
  bigraded modules

abstract:
  Let $S=K[x_1,\ldots,x_n]$ be the polynomial ring over the field $K$, and let
$I\subset S$ be a graded ideal. It is shown that the higher iterated Hilbert
coefficients of the graded $S$-modules $\Tor_i^S(M,I^k)$ and $\Ext^i_S(M,I^k)$
are polynomial functions in $k$, and an upper bound for their degree is given.
These results are derived by considering suitable bigraded modules.


title:
Iterative reconstruction of SiPM light response functions in a
  square-shaped compact gamma camera

abstract:
  Compact gamma cameras with a square-shaped monolithic scintillator crystal
and an array of silicon photomultipliers (SiPMs) are actively being developed
for applications in areas such as small animal imaging, cancer diagnostics and
radiotracer guided surgery. Statistical methods of position reconstruction,
which are potentially superior to the traditional centroid method, require
accurate knowledge of the spatial response of each photomultiplier. Using both
Monte Carlo simulations and experimental data obtained with a camera prototype,
we show that the spatial response of all photomultipliers (light response
functions) can be parameterized with axially symmetric functions obtained
iteratively from flood field irradiation data. The study was performed with a
camera prototype equipped with a 30 x 30 x 2 mm3 LYSO crystal and an 8 x 8
array of SiPMs for 140 keV gamma rays. The simulations demonstrate that the
images, reconstructed with the maximum likelihood method using the response
obtained with the iterative approach, exhibit only minor distortions: the
average difference between the reconstructed and the true positions in X and Y
directions does not exceed 0.2 mm in the central area of 22 x 22 mm2 and 0.4 mm
at the periphery of the camera. A similar level of image distortions is shown
experimentally with the camera prototype.


title:
Improving thermoelectric performance of TiNiSn by mixing MnNiSb in the
  half-Heusler structure

abstract:
  The thermoelectric properties of n type semiconductor, TiNiSn is optimized by
partial substitution with metallic, MnNiSb in the half Heusler structure.
Herein, we study the transport properties and intrinsic phase separation in the
system. The Ti1-xMnxNiSn1-xSbx alloys were prepared by arc-melting and were
annealed at temperatures obtained from differential thermal analysis and
differential scanning calorimetry results. The phases were characterized using
powder X-ray diffraction patterns, energy dispersive X-ray spectroscopy, and
differential scanning calorimetry. After annealing the majority phase was
TiNiSn with some Ni rich sites and the minority phases was majorly Ti6Sn5, Sn,
and MnSn2. Ni rich sites were caused by Frenkel defects, this led to a
metal-like behavior of the semiconducting specimens at low temperature. For x
up to 0.05 the samples showed an activated conduction, whereas for x>0.05 they
showed metallic character. The figure of merit for x=0.05 was increased by 61%
(ZT=0.45) in comparison to the pure TiNiSn.


title:
Exploiting Lack of Hardware Reciprocity for Sender-Node Authentication
  at the PHY Layer

abstract:
  This paper proposes to exploit the so-called {\it reciprocity parameters}
(modelling non-reciprocal communication hardware) to use them as decision
metric for binary hypothesis testing based authentication framework at a
receiver node Bob. Specifically, Bob first learns the reciprocity parameters of
the legitimate sender Alice via initial training. Then, during the test phase,
Bob first obtains a measurement of reciprocity parameters of channel occupier
(Alice, or, the intruder Eve). Then, with ground truth and current measurement
both in hand, Bob carries out the hypothesis testing to automatically accept
(reject) the packets sent by Alice (Eve). For the proposed scheme, we provide
its success rate (the detection probability of Eve), and its performance
comparison with other schemes.


title: Implications of lepton nonuniversality in the beauty sector

abstract:
  The phenomenon of CP violation in the standard model (SM) framework and the
decay dynamics have been established from the data obtained from the B
factories and so far we have not seen anything new. Nevertheless, there have
been instances of deviations in many measured observables in the flavor sector,
as far as the data and predictions are concerned. Here we will mention some
deviations obtained in measurements related to lepton universality, as seen
from the data, and try to understand their implications. To accommodate the
observed data we will consider a leptoquark model, which seems to be one
interesting model beyond the SM.


title:
Bounded Confidence under Preferential Flip: A Coupled Dynamics of
  Structural Balance and Opinions

abstract:
  In this work we study the coupled dynamics of social balance and opinion
formation. We propose a model where agents form opinions under bounded
confidence, but only considering the opinions of their friends. The signs of
social ties -friendships and enmities- evolve seeking for social balance,
taking into account how similar agents' opinions are. We consider both the case
where opinions have one and two dimensions. We find that our dynamics produces
the segregation of agents into two cliques, with the opinions of agents in one
clique differing from those in the other. Depending on the level of bounded
confidence, the dynamics can produce either consensus of opinions within each
clique or the coexistence of several opinion clusters in a clique. For the
uni-dimensional case, the opinions in one clique are all below the opinions in
the other clique, hence defining a "left clique" and a "right clique". In the
two-dimensional case, our numerical results suggest that the two cliques are
separated by a hyperplane in the opinion space. We also show that the
phenomenon of unidimensional opinions identified by DeMarzo, Vayanos and
Zwiebel (Q J Econ 2003) extends partially to our dynamics. Finally, in the
context of politics, we comment about the possible relation of our results to
the fragmentation of an ideology and the emergence of new political parties.


title:
A second-order accurate numerical method for the space-time tempered
  fractional diffusion-wave equation

abstract:
  This paper focuses on providing the high order algorithms for the space-time
tempered fractional diffusion-wave equation. The designed schemes are
unconditionally stable and have the global truncation error
$\mathcal{O}(\tau^2+h^2)$, being theoretically proved and numerically verified.


title:
On Strongly Nonlinear Eigenvalue Problems in the Framework of
  Nonreflexive Orlicz-Sobolev Spaces

abstract:
  It is established existence and multiplicity of solutions for strongly
nonlinear problems driven by the $\Phi$-Laplacian operator on bounded domains.
Our main results are stated without the so called $\Delta_{2}$ condition at
infinity which means that the underlying Orlicz-Sobolev spaces are not
reflexive.


title: How the Pauli exclusion principle affects fusion of atomic nuclei

abstract:
  The Pauli exclusion principle induces a repulsion between composite systems
of identical fermions such as colliding atomic nuclei. Our goal is to study how
heavy-ion fusion is impacted by this "Pauli repulsion". We propose a new
microscopic approach, the density-constrained frozen Hartree-Fock method, to
compute the bare potential including the Pauli exclusion principle exactly.
Pauli repulsion is shown to be important inside the barrier radius and
increases with the charge product of the nuclei. Its main effect is to reduce
tunnelling probability. Pauli repulsion is part of the solution to the
long-standing deep sub-barrier fusion hindrance problem.


title:
Radiation pressure induced difference-sideband generation beyond
  linearized description

abstract:
  We investigate radiation-pressure induced generation of the frequency
components at the difference-sideband in an optomechanical system, which beyond
the conventional linearized description of optomechanical interactions between
cavity fields and the mechanical oscillation. We analytically calculate
amplitudes of these signals, and identify a simple square-root law for both the
upper and lower difference-sideband generation which can describe the
dependence of the intensities of these signals on the pump power. Further
calculation shows that difference-sideband generation can be greatly enhanced
via achieving the matching conditions. The effect of difference-sideband
generation, which may have potential application for manipulation of light, is
especially suited for on-chip optomechanical devices, where nonlinear
optomechanical interaction in the weak coupling regime is within current
experimental reach.


title:
Higher lying resonances in low-energy electron scattering with carbon
  monoxide

abstract:
  R-matrix calculations on electron collisions with CO are reported whose aim
is to identify any higher-lying resonances above the well-reported and lowest
$^2\Pi$ resonance at about 1.6~eV. Extensive tests with respect to basis sets,
target models and scattering models are performed. The final results are
reported for the larger cc-pVTZ basis set using a 50 state close-coupling (CC)
calculation. The Breit-Wigner eigenphase sum and the time-delay methods are
used to detect and fit any resonances. Both these methods find a very narrow
$^2\Sigma^+$ symmetry Feshbach-type resonance very close to the target
excitation threshold of the b $^3\Sigma^+$ state which lies at 12.9 eV in the
calculations. This resonance is seen in the CC calculation using cc-pVTZ basis
set while a CC calculation using the cc-pVDZ basis set does not produce this
feature. The electronic structure of CO$^-$ is analysed in the asymptotic
region, 45 molecular states are found to correlate with states dissociating to
an anion and an atom. Electronic structure calculations are used to study the
behaviour of these states at large internuclear separation. Quantitative
results for the total, elastic and electronic excitation cross sections are
also presented. The significance of these results for models of the observed
dissociative electron attachment of CO in the 10 eV region is discussed.


title:
Irreversible Work versus Fidelity Susceptibility for infinitesimal
  quenches

abstract:
  We compare the irreversible work produced in an infinitesimal sudden quench
of a quantum system at zero temperature with its ground state fidelity
susceptibility, giving an explicit relation between the two quantities. We find
that the former is proportional to the latter but for an extra term appearing
in the irreversible work which includes also contributions from the excited
states. We calculate explicitly the two quantities in the case of the quantum
Ising chain, showing that at criticality they exhibit different scaling
behavior. The irreversible work, rescaled by square of the quench's amplitude,
exhibits a divergence slower than the fidelity susceptibility one. As a
consequence, the two quantities obey also different finite-size scaling
relations.


title:
Design and Implementation of a Fleet Management System Using Novel
  GPS/GLONASS Tracker and Web-Based Software

abstract:
  Knowing where the vehicles are, what the drivers doing and monitoring every
event in real time is the key parameters for a well-managed decision-making
process. In this paper, a novel approach for control and monitoring of a fleet
management system using three elements including GPS/GLONASS-based automatic
vehicle locators (called Rad100), GPRS/SMS GSM cellular network and web-based
software (called PayaRadyab) is proposed to show exact position of the desired
vehicle on different maps and take detailed reports of the mission, travelled
path, fuel consumption rate, speed limits, and other necessary information
according to the customers requests. The most significant features of the
proposed system are its global covering, high accuracy of positioning, easy
operation by the user at any location, and easy energy management. In this
study, I have designed and fabricated more than 50 Rad100 trackers and also
programmed a web-based PayaRadyab software in which their performance and
accuracy have been confirmed by the practical results in different conditions.


title: Spectral partitioning in equitable graphs

abstract:
  Graph partitioning problems emerge in a wide variety of complex systems,
ranging from biology to finance, but can be rigorously analyzed and solved only
for a few graph ensembles. Here, an ensemble of equitable graphs, i.e. random
graphs with a block-regular structure, is studied, for which analytical results
can be obtained. In particular, the spectral density of this ensemble is
computed exactly for a modular and bipartite structure. Kesten-McKay's law for
random regular graphs is found analytically to apply also for modular and
bipartite structures when blocks are homogeneous. Exact solution to graph
partitioning for two equal-sized communities is proposed and verified
numerically, and a conjecture on the absence of an efficient recovery
detectability transition in equitable graphs is suggested. Final discussion
summarizes results and outlines their relevance for the solution of graph
partitioning problems in other graph ensembles, in particular for the study of
detectability thresholds and resolution limits in stochastic block models.


title: Holographic Butterfly Effect at Quantum Critical Points

abstract:
  When the Lyapunov exponent $\lambda_L$ in a quantum chaotic system saturates
the bound $\lambda_L\leqslant 2\pi k_BT$, it is proposed that this system has a
holographic dual described by a gravity theory. In particular, the butterfly
effect as a prominent phenomenon of chaos can ubiquitously exist in a black
hole system characterized by a shockwave solution near the horizon. In this
paper we propose that the butterfly velocity can be used to diagnose quantum
phase transition (QPT) in holographic theories. We provide evidences for this
proposal with an anisotropic holographic model exhibiting metal-insulator
transitions (MIT), in which the derivatives of the butterfly velocity with
respect to system parameters characterizes quantum critical points (QCP) with
local extremes in zero temperature limit. We also point out that this proposal
can be tested by experiments in the light of recent progress on the measurement
of out-of-time-order correlation function (OTOC).


title:
Transmission Strategies for Remote Estimation with an Energy Harvesting
  Sensor

abstract:
  We consider the remote estimation of a time-correlated signal using an energy
harvesting (EH) sensor. The sensor observes the unknown signal and communicates
its observations to a remote fusion center using an amplify-and-forward
strategy. We consider the design of optimal power allocation strategies in
order to minimize the mean-square error at the fusion center. Contrary to the
traditional approaches, the degree of correlation between the signal values
constitutes an important aspect of our formulation. We provide the optimal
power allocation strategies for a number of illustrative scenarios. We show
that the most majorized power allocation strategy, i.e. the power allocation as
balanced as possible, is optimal for the cases of circularly wide-sense
stationary (c.w.s.s.) signals with a static correlation coefficient, and
sampled low-pass c.w.s.s. signals for a static channel. We show that the
optimal strategy can be characterized as a water-filling type solution for
sampled low-pass c.w.s.s. signals for a fading channel. Motivated by the
high-complexity of the numerical solution of the optimization problem, we
propose low-complexity policies for the general scenario. Numerical evaluations
illustrate the close performance of these low-complexity policies to that of
the optimal policies, and demonstrate the effect of the EH constraints and the
degree of freedom of the signal.


title: Markovian heat sources with the smallest heat capacity

abstract:
  Thermal Markovian dynamics is typically obtained by coupling a system to a
sufficiently hot bath with a large heat capacity. Here we present a scheme for
inducing Markovian dynamics using an arbitrarily small and cold heat bath. The
scheme is based on injecting phase noise to the small bath. Several unique
signatures of small bath are studied. We discuss realizations in ion traps and
superconducting qubits and show that it is possible to create an ideal setting
where the system dynamics is indifferent to the internal bath dynamics.


title: Internal and external duality in abstract polytopes

abstract:
  We define an abstract regular polytope to be internally self-dual if its
self-duality can be realized as one of its symmetries. This property has many
interesting implications on the structure of the polytope, which we present
here. Then, we construct many examples of internally self-dual polytopes. In
particular, we show that there are internally self-dual regular polyhedra of
each type $\{p, p\}$ for $p \geq 3$ and that there are both infinitely many
internally self-dual and infinitely many externally self-dual polyhedra of type
$\{p, p\}$ for $p$ even. We also show that there are internally self-dual
polytopes in each rank, including a new family of polytopes that we construct
here.


title:
Nonclassic boundary value problems in the theory of irregular systems of
  equations with partial derivatives

abstract:
  The linear PDE ${\mathbf B} {\mathbf L} (\frac{\partial}{\partial x}) u
={\mathbf L}_1(\frac{\partial}{\partial x})u +f(x)$ with nonclassic conditions
on boundary $\partial \Omega$ is considered. Here ${\mathbf B}$ is linear
noninvertible bounded operator acting from linear space $E$ into $E,$
$x=(t,x_1,\dots, x_m) \in \Omega, $ $\Omega \subset {\mathbb R}^{m+1}.$ It is
assumed that ${\mathbf B}$ enjoys the skeleton decomposition ${\mathbf
B}={\mathbf A}_1 {\mathbf A}_2,$ ${\mathbf A}_2 \in {\mathcal L}(E\rightarrow
E_1),$ ${\mathbf A}_1 \in {\mathcal L}(E_1\rightarrow E)$ where $E_1$ is linear
normed space. Differential operators ${\mathbf L}, \, {\mathbf L}_1$ are
partial differential operators. In the concrete cases the domains of definition
of operators ${\mathbf L}, {\mathbf L}_1$ consist of linear manifolds
$E_{\partial}$ of sufficiently smooth abstract functions $u(x)$ with domain in
$\Omega$ and their ranges in $E,$ which satisfy certain system of homogeneous
boundary conditions. The abstract function $f: \Omega \subset {\mathbb R}^{m+1}
\rightarrow E $ is assumed to be given. It is requested to find the solution
$u: \Omega \subset {\mathbb R}^{m+1} \rightarrow E_{\partial},$ which satisfy
certain condition on boundary $\partial \Omega.$ The concept of a skeleton
chains is introduced as sequence of linear operators ${\mathbf B}_i \in
{\mathcal L}(E_i \rightarrow E_i), \, i=1,2,\dots, p,$ where $E_i$ are linear
spaces corresponding to the skeleton decomposition of operator ${\mathbf B}.$
It is assumed that irreversible operator ${\mathbf B}$ generates skeleton chain
of the finite length $p.$ The problem is reduced to a regular split system with
respect to higher order derivative terms with certain initial and boundary
conditions.


title:
Interconnections between equilibrium topology and dynamical quantum
  phase transitions in a linearly ramped Haldane model

abstract:
  We study the behavior of Fisher Zeros (FZs) and dynamical quantum phase
transitions (DQPTs) for a linearly ramped Haldane model occurring in the
subsequent temporal evolution of the same and probe the intimate connection
with the equilibrium topology of the model}. Here, we investigate the temporal
evolution of the final state of the Haldane Hamiltonian (evolving with
time-independent final Hamiltonian) reached following a linear ramping of the
staggered (Semenoff) mass term from an initial to a final value, {first
selecting a specific protocol}, so chosen that the system is ramped from one
non-topological phase to the other through a topological phase. {We establish
the existence of three possible behaviour of areas of FZs corresponding to a
given sector: (i) no-DQPT, (ii) one-DQPT (intermediate) and (iii)two-DQPTs
(re-entrant), depending on the inverse quenching rate $\tau$. Our study also
reveals that the appearance of the areas of FZs is an artefact of the non-zero
(quasi-momentum dependent) Haldane mass ($M_H$), whose absence leads to an
emergent one-dimensional behaviour indicated by the shrinking of the areas FZs
to lines and the non-analyticity in the dynamical "free energy" itself.
Moreover, the characteristic rates of crossover between the three behaviour of
FZs are determined by the time-reversal invariant quasi-momentum points of the
Brillouin zone where $M_H$ vanishes. Thus, we observe that through the presence
or absence of $M_H$, there exists an intimate relation to the topological
properties of the equilibrium model even when the ramp drives the system far
away from equilibrium.


title: On the Mints Hierarchy in First-Order Intuitionistic Logic

abstract:
  We stratify intuitionistic first-order logic over $(\forall,\to)$ into
fragments determined by the alternation of positive and negative occurrences of
quantifiers (Mints hierarchy).
  We study the decidability and complexity of these fragments. We prove that
even the $\Delta_2$ level is undecidable and that $\Sigma_1$ is
Expspace-complete. We also prove that the arity-bounded fragment of $\Sigma_1$
is complete for co-Nexptime.


title: A Sparse Regular Approximation Lemma

abstract:
  We introduce a new variant of Szemer\'edi's regularity lemma which we call
the "sparse regular approximation lemma" (SRAL). The input to this lemma is a
graph $G$ of edge density $p$ and parameters $\epsilon, \delta$, where we think
of $\delta$ as a constant. The goal is to construct an $\epsilon$-regular
partition of $G$ while having the freedom to add/remove up to $\delta |E(G)|$
edges. As we show here, this weaker variant of the regularity lemma already
suffices for proving the graph removal lemma and the hypergraph regularity
lemma, which are two of the main applications of the (standard) regularity
lemma. This of course raises the following question: can one obtain
quantitative bounds for SRAL that are significantly better than those
associated with the regularity lemma?
  Our first result answers the above question affirmatively by proving an upper
bound for SRAL given by a tower of height $O(\log 1/p)$. This allows us to
reprove Fox's upper bound for the graph removal lemma. Our second result is a
matching lower bound for SRAL showing that a tower of height $\Omega(\log 1/p)$
is unavoidable. We in fact prove a more general multicolored lower bound which
is essential for proving lower bounds for the hypergraph regularity lemma.


title:
Microscopic potential model analysis of the radiative $(n,\gamma)$ cross
  sections near the $Z=50$ shell closure taking part in the main s-component

abstract:
  The neutron capture cross sections have been studied near the $Z=50$ closed
shell for a number of nuclei those take part in heavy element nucleosynthesis,
the slow and the rapid neutron capture processes and the proton capture
process. An optical model potential is constructed in theoretical approach by
folding the density dependent M3y purely real nucleon-nucleon interaction with
the target radial matter density in relativistic mean field (RMF) approach. The
standard code TALYS1.8 is used for cross-section calculation. We have presented
the Maxwellian-averaged capture cross-section (MACS) values and stellar neutron
capture reaction rates at astrophysically relevant thermal energies and
temperatures.


title: Multidimensional transition fronts for Fisher-KPP reactions

abstract:
  We study entire solutions to homogeneous reaction-diffusion equations in
several dimensions with Fisher-KPP reactions. Any entire solution $0<u<1$ is
known to satisfy \[ \lim_{t\to -\infty} \sup_{|x|\le c|t|} u(t,x) = 0 \qquad
\text{for each $c<2\sqrt{f'(0)}\,$,} \] and we consider here those satisfying
\[ \lim_{t\to -\infty} \sup_{|x|\le c|t|} u(t,x) = 0 \qquad \text{for some
$c>2\sqrt{f'(0)}\,$.} \] When $f$ is $C^2$ and concave, our main result
provides an almost complete characterization of transition fronts as well as
transition solutions with bounded width within this class of solutions.


title: Efficient transfer of an arbitrary qutrit state in circuit QED

abstract:
  Compared with a qubit, a qutrit (i.e., three-level quantum system) has a
larger Hilbert space and thus can be used to encode more information in quantum
information processing and communication. Here, we propose a scheme to transfer
an arbitrary quantum state between two flux qutrits coupled to two resonators.
This scheme is simple because it only requires two basic operations. The
state-transfer operation can be performed fast because of using resonant
interactions only. Numerical simulations show that high-fidelity transfer of
quantum states between the two qutrits is feasible with current circuit-QED
technology. This scheme is quite general and can be applied to accomplish the
same task for other solid-state qutrits coupled to resonators.


title:
Minimax Optimality of Shiryaev-Roberts Procedure for Quickest Drift
  Change Detection of a Brownian motion

abstract:
  The problem of detecting a change in the drift of a Brownian motion is
considered. The change point is assumed to have a modified exponential prior
distribution with unknown parameters. A worst-case analysis with respect to
these parameters is adopted leading to a min-max problem formulation.
Analytical and numerical justifications are provided towards establishing that
the Shiryaev-Roberts procedure with a specially designed starting point is
exactly optimal for the proposed mathematical setup.


title: Gravity, holography and applications to condensed matter

abstract:
  Momentum relaxation is an ever-present and unavoidable ingredient of any
realistic condensed matter system. In real-world materials the presence of a
lattice, impurities or disorder forces momentum to dissipate and leads to
relevant physical effects such as the finiteness of the DC transport
properties, i.e. conductivities. The main purpose of this thesis is the
introduction of momentum dissipation and its consequent effects into the
framework of AdS/CMT, namely the applications of the gauge-gravity duality to
condensed matter. A convenient and effective way of breaking the translational
symmetry associated to such a conservation law is provided by massive gravity
(MG) bulk theories. We consider generic massive gravity models embedded into
asymptotically Anti de Sitter spacetime and we analyze them using holographic
techniques. We study in detail their consistency and stability. We then focus
our attention on the transport properties of the CFT duals. A big part of our
work is devoted to the analysis of the electric conductivity in relation to
possible universal bounds and the existence of holographic metal-insulator
transitions. We moreover initiate the study of the viscoelastic response and we
consider the possible violation of the well known KSS bound. We finally
describe the effects of momentum relaxation on the well known holographic
models for superconductivity.

categories: hep-th cond-mat.str-el cond-mat.supr-con gr-qc


title:
Perturbation theory for short-range weakly-attractive potentials in one
  dimension

abstract:
  We have obtained the perturbative expressions up to sixth order for the
energy of the bound state in a one dimensional, arbitrarily weak, short range
finite well, applying a method originally developed by Gat and Rosenstein Ref.
[3]. The expressions up to fifth order reproduce the results already known in
the literature, while the sixth order had not been calculated before. As an
illustration of our formulas we have applied them to two exactly solvable
problems and to a nontrivial problem.


title: Interpreting Neural Networks to Improve Politeness Comprehension

abstract:
  We present an interpretable neural network approach to predicting and
understanding politeness in natural language requests. Our models are based on
simple convolutional neural networks directly on raw text, avoiding any manual
identification of complex sentiment or syntactic features, while performing
better than such feature-based models from previous work. More importantly, we
use the challenging task of politeness prediction as a testbed to next present
a much-needed understanding of what these successful networks are actually
learning. For this, we present several network visualizations based on
activation clusters, first derivative saliency, and embedding space
transformations, helping us automatically identify several subtle linguistics
markers of politeness theories. Further, this analysis reveals multiple novel,
high-scoring politeness strategies which, when added back as new features,
reduce the accuracy gap between the original featurized system and the neural
model, thus providing a clear quantitative interpretation of the success of
these neural networks.


abstract:
  Monte Carlo is famous for accepting model extensions and model refinements up
to infinite dimension. However, this powerful incremental design is based on a
premise which has severely limited its application so far: a state-variable can
only be recursively defined as a function of underlying state-variables if this
function is linear. Here we show that this premise can be alleviated by
projecting nonlinearities onto a polynomial basis and increasing the
configuration space dimension. Considering phytoplankton growth in
light-limited environments, radiative transfer in planetary atmospheres,
electromagnetic scattering by particles, and concentrated solar power plant
production, we prove the real-world usability of this advance in four test
cases which were previously regarded as impracticable using Monte Carlo
approaches. We also illustrate an outstanding feature of our method when
applied to acute problems with interacting particles: handling rare events is
now straightforward. Overall, our extension preserves the features that made
the method popular: addressing nonlinearities does not compromise on model
refinement or system complexity, and convergence rates remain independent of
dimension.
  Published: Dauchet J, Bezian J-J, Blanco S, Caliot C, Charon J, Coustet C, El
Hafi M, Eymet V, Farges O, Forest V, Fournier R, Galtier M, Gautrais J, Khuong
A, Pelissier L, Piaud B, Roger M, Terr\'ee G, Weitz S (2018) Addressing
nonlinearities in Monte Carlo. Sci. Rep. 8: 13302,
DOI:10.1038/s41598-018-31574-4


title:
Gate-induced insulator to band-like transport transition in organolead
  halide perovskite

abstract:
  Understanding the intrinsic charge transport in organolead halide perovskites
is essential for the development of high-efficiency photovoltaics and other
optoelectronic devices. Despite the rapid advancement of the organolead halide
perovskite in photovoltaic and optoelectronic applications, the intrinsic
charge carrier transport in these materials remains elusive partly due to the
difficulty of fabricating electrical devices and obtaining good electrical
contact. Here, we report the fabrication of organolead halide perovskite
microplates with monolayer graphene as low barrier electrical contact. A
systematic charge transport studies reveal an insulator to band-like transport
transition. Our studies indicate that the insulator to band-like transport
transition depends on the orthorhombic-to-tetragonal phase transition
temperature and defect densities of the organolead halide perovskite
microplates. Our findings are not only important for the fundamental
understanding of charge transport behavior but also offer valuable practical
implications for photovoltaics and optoelectronic applications based on the
organolead halide perovskite.


title:
Computing Majority by Constant Depth Majority Circuits with Low Fan-in
  Gates

abstract:
  We study the following computational problem: for which values of $k$, the
majority of $n$ bits $\text{MAJ}_n$ can be computed with a depth two formula
whose each gate computes a majority function of at most $k$ bits? The
corresponding computational model is denoted by $\text{MAJ}_k \circ
\text{MAJ}_k$. We observe that the minimum value of $k$ for which there exists
a $\text{MAJ}_k \circ \text{MAJ}_k$ circuit that has high correlation with the
majority of $n$ bits is equal to $\Theta(n^{1/2})$. We then show that for a
randomized $\text{MAJ}_k \circ \text{MAJ}_k$ circuit computing the majority of
$n$ input bits with high probability for every input, the minimum value of $k$
is equal to $n^{2/3+o(1)}$. We show a worst case lower bound: if a
$\text{MAJ}_k \circ \text{MAJ}_k$ circuit computes the majority of $n$ bits
correctly on all inputs, then $k\geq n^{13/19+o(1)}$. This lower bound exceeds
the optimal value for randomized circuits and thus is unreachable for pure
randomized techniques. For depth $3$ circuits we show that a circuit with $k=
O(n^{2/3})$ can compute $\text{MAJ}_n$ correctly on all inputs.


title: LHC Phenomenology of Composite 2-Higgs Doublet Models

abstract:
  We investigate the phenomenology of Composite 2-Higgs Doublet Models (C2HDMs)
of various Yukawa types based on the global symmetry breaking $SO(6)\to
SO(4)\times SO(2)$. The kinetic term and the Yukawa Lagrangian are constructed
in terms of the pseudo Nambu-Goldstone Boson (pNGB) matrix and a 6-plet of
fermions under $SO(6)$. The scalar potential is assumed to be the same as that
of the Elementary 2-Higgs Doublet Model (E2HDM) with a softly-broken discrete
$Z_2$ symmetry. We then discuss the phenomenological differences between the
E2HDM and C2HDM by focusing on the deviations from Standard Model (SM)
couplings of the discovered Higgs state ($h$) as well as on the production
cross sections and Branching Ratios (BRs) at the Large Hadron Collider (LHC) of
extra Higgs bosons. We find that, even if the same deviation in the $hVV$
($V=W,Z$) coupling is assumed in both scenarios, there appear significant
differences between E2HDM and C2HDM from the structure of the Yukawa couplings,
so that production and decay features of extra Higgs bosons can be used to
distinguish between the two scenarios.


title: Metal hydrogen critical temperature at the pressure 500 GPa

abstract:
  \'Eliashberg theory, being generalized to the case of the electron-phonon
(EP) systems with the not constant density of electronic states, as well as to
the frequency behavior of the renormalization of both the electron mass and the
chemical potential, is used to study the normal properties and of the metal
hydrogen phase under pressure of P = 500 GPa. The phonon contribution to the
anomalous electron Green's function (GF) is considered. The pairing is
considered within the overall width of the electron band, and not only in a
narrow layer at the Fermi surface. The frequency dependence of the electron
mass renormalization ReZ , the density of electronic states , the spectral
function of the electron-phonon interaction, obtained by calculation are used
to calculate the electronic abnormal GF. The \'Eliashberg generalized equations
with the variable density of electronic states are resolved. The dependence of
both the real and the imaginary parts of the order parameter on the frequency
in the phase is obtained. The value for the metal hydrogen phase at the
pressure P = 500 GPa has been defined.