title: Transverse wobbling motion in $^{134}$Ce and $^{136}$Nd

abstract:
  The existence of one-phonon and possible two-phonon transverse wobbling bands
is proposed for the first time in two even-even nuclei, $^{134}$Ce and
$^{136}$Nd. The predominant $E2$ character of the $\Delta I = 1$ transitions
connecting the one-phonon wobbling band in $^{134}$Ce to the two-quasiparticle
yrast band supports the wobbling interpretation. The extracted wobbling
frequencies decrease with increasing spin, indicating the transverse character
of the wobbling motion, with the angular momenta of the two quasiparticles
aligned perpendicular to the axis of collective rotation. A candidate for
two-phonon wobbling motion is also proposed in $^{136}$Nd. The wobbling
frequencies calculated in the harmonic frozen approximation are in good
agreement with the experimental ones for both the$^{134}$Ce and $^{136}$Nd
nuclei.


title:
Influence of defect thickness on the angular dependence of coercivity in
  rare-earth permanent magnets

abstract:
  The coercive field and angular dependence of the coercive field of
single-grain Nd$_{2}$Fe$_{14}$B permanent magnets are computed using finite
element micromagnetics. It is shown that the thickness of surface defects plays
a critical role in determining the reversal process. For small defect
thicknesses reversal is heavily driven by nucleation, whereas with increasing
defect thickness domain wall de-pinning becomes more important. This change
results in an observable shift between two well-known behavioral models.
  A similar trend is observed in experimental measurements of bulk samples,
where a Nd-Cu infiltration process has been used to enhance coercivity by
modifying the grain boundaries. When account is taken of the imperfect grain
alignment of real magnets, the single-grain computed results appears to closely
match experimental behaviour.


title: Effectiveness of Hindman's theorem for bounded sums

abstract:
  We consider the strength and effective content of restricted versions of
Hindman's Theorem in which the number of colors is specified and the length of
the sums has a specified finite bound. Let $\mathsf{HT}^{\leq n}_k$ denote the
assertion that for each $k$-coloring $c$ of $\mathbb{N}$ there is an infinite
set $X \subseteq \mathbb{N}$ such that all sums $\sum_{x \in F} x$ for $F
\subseteq X$ and $0 < |F| \leq n$ have the same color. We prove that there is a
computable $2$-coloring $c$ of $\mathbb{N}$ such that there is no infinite
computable set $X$ such that all nonempty sums of at most $2$ elements of $X$
have the same color. It follows that $\mathsf{HT}^{\leq 2}_2$ is not provable
in $\mathsf{RCA}_0$ and in fact we show that it implies $\mathsf{SRT}^2_2$ in
$\mathsf{RCA}_0$. We also show that there is a computable instance of
$\mathsf{HT}^{\leq 3}_3$ with all solutions computing $0'$. The proof of this
result shows that $\mathsf{HT}^{\leq 3}_3$ implies $\mathsf{ACA}_0$ in
$\mathsf{RCA}_0$.


title: 750 GeV Diphoton Resonance in Warped Geometries

abstract:
  We examine the scenario of a warped extra dimension containing bulk SM fields
in light of the observed diphoton excess at 750 GeV. We demonstrate that a
spin-2 graviton whose action contains localized kinetic brane terms for both
gravity and gauge fields is compatible with the excess, while being consistent
with all other constraints. The graviton sector of this model contains a single
free parameter, once the mass of the graviton is fixed. The scale of physics on
the IR-brane is found to lie in the range of a $\sim$ few TeV, relevant to the
gauge hierarchy. There remains significant flexibility in the coupled
gauge/fermion KK sectors to address the strong constraints arising from
precision measurements.


title: Exceptionally simple PDE

abstract:
  We give local descriptions of parabolic contact structures and show how their
flat models yield explicit PDE having symmetry algebras isomorphic to all
complex simple Lie algebras except $\mathfrak{sl}_2$. This yields a remarkably
uniform generalization of the Cartan-Engel models from 1893 in the $G_2$ case.
We give a formula for the harmonic curvature of a $G_2$-contact structure and
describe submaximally symmetric models for general $G$-contact structures.


title:
Predictive Modeling of Opinion and Connectivity Dynamics in Social
  Networks

abstract:
  Recent years saw an increased interest in modeling and understanding the
mechanisms of opinion and innovation spread through human networks. Using
analysis of real-world social data, researchers are able to gain a better
understanding of the dynamics of social networks and subsequently model the
changes in such networks over time. We developed a social network model that
both utilizes an agent-based approach with a dynamic update of opinions and
connections between agents and reflects opinion propagation and structural
changes over time as observed in real-world data. We validate the model using
data from the Social Evolution dataset of the MIT Human Dynamics Lab describing
changes in friendships and health self-perception in a targeted student
population over a nine-month period. We demonstrate the effectiveness of the
approach by predicting changes in both opinion spread and connectivity of the
network. We also use the model to evaluate how the network parameters, such as
the level of `openness' and willingness to incorporate opinions of neighboring
agents, affect the outcome. The model not only provides insight into the
dynamics of ever changing social networks, but also presents a tool with which
one can investigate opinion propagation strategies for networks of various
structures and opinion distributions.


title: Negative Learning Rates and P-Learning

abstract:
  We present a method of training a differentiable function approximator for a
regression task using negative examples. We effect this training using negative
learning rates. We also show how this method can be used to perform direct
policy learning in a reinforcement learning setting.


title: Nonlocality from local contextuality

abstract:
  We experimentally show that nonlocality can be produced from single-particle
contextuality by using two-particle correlations which do not violate any Bell
inequality by themselves. This demonstrates that nonlocality can come from an
{\em a priori} different simpler phenomenon, and connects contextuality and
nonlocality, the two critical resources for, respectively, quantum computation
and secure communication. From the perspective of quantum information, our
experiment constitutes a proof of principle that quantum systems can be used
simultaneously for both quantum computation and secure communication.


title: Chromatic roots and minor-closed families of graphs

abstract:
  Given a minor-closed class of graphs $\mathcal{G}$, what is the infimum of
the non-trivial roots of the chromatic polynomial of $G \in \mathcal{G}$? When
$\mathcal{G}$ is the class of all graphs, the answer is known to be $32/27$. We
answer this question exactly for three minor-closed classes of graphs.
Furthermore, we conjecture precisely when the value is larger than $32/27$.


title: Highly nonlinear wave solutions in a dual to the chiral model

abstract:
  We consider a two-dimensional scalar field theory with a nilpotent current
algebra, which is dual to the Principal Chiral Model. The quantum theory is
renormalizable and not asymptotically free: the theory is strongly coupled at
short distances (encountering a Landau pole). We suggest it can serve as a toy
model for $\lambda\phi^{4}$ theory in four dimensions, just as the principal
chiral model is a useful toy model for Yang-Mills theory. We find some
classical wave solutions that survive the strong coupling limit and quantize
them by the collective variable method. They describe excitations with an
unusual dispersion relation $\omega\propto|k|^{\frac{2}{3}}$ . Perhaps they are
the "preons" at strong coupling, whose bound states form massless particles
over long distances.


title:
The C(3P) + NH3 reaction in interstellar chemistry: I. Investigation of
  the product formation channels

abstract:
  The product formation channels of ground state carbon atoms, C(3P), reacting
with ammonia, NH3, have been investigated using two complementary experiments
and electronic structure calculations. Reaction products are detected in a gas
flow tube experiment (330 K, 4 Torr) using tunable VUV photoionization coupled
with time of flight mass spectrometry. Temporal profiles of the species formed
and photoionization spectra are used to identify primary products of the C +
NH3 reaction. In addition, H-atom formation is monitored by VUV laser induced
fluorescence from room temperature to 50 K in a supersonic gas flow generated
by the Laval nozzle technique. Electronic structure calculations are performed
to derive intermediates, transition states and complexes formed along the
reaction coordinate. The combination of photoionization and laser induced
fluorescence experiments supported by theoretical calculations indicate that in
the temperature and pressure range investigated, the H + H2CN production
channel represents 100% of the product yield for this reaction. Kinetics
measurements of the title reaction down to 50 K and the effect of the new rate
constants on interstellar nitrogen hydride abundances using a model of dense
interstellar clouds are reported in paper II.


title: Conductance of a proximitized nanowire in the Coulomb blockade regime

abstract:
  We identify the leading processes of electron transport across finite-length
segments of proximitized nanowires and build a quantitative theory of their
two-terminal conductance. In the presence of spin-orbit interaction, a nanowire
can be tuned across the topological transition point by an applied magnetic
field. Due to a finite segment length, electron transport is controlled by the
Coulomb blockade. Upon increasing of the field, the shape and magnitude of the
Coulomb blockade peaks in the linear conductance is defined, respectively, by
Andreev reflection, single-electron tunneling, and resonant tunneling through
the Majorana modes emerging after the topological transition. Our theory
provides the framework for the analysis of experiments with proximitized
nanowires, such as reported in Albrecht et al., Nature 531, 206-209 (2016), and
identifies the signatures of the topological transition in the two-terminal
conductance.


title: Engineering Holographic Superconductor Phase Diagrams

abstract:
  We study how to engineer holographic models with features of a high
temperature superconductor phase diagram. We introduce a field in the bulk
which provides a tunable "doping" parameter in the boundary theory. By
designing how this field changes the effective masses of other order parameter
fields, desired phase diagrams can be engineered. We give examples of
generating phase diagrams with phase boundaries similar to a superconducting
dome and an anti-ferromagnetic phase by including two order parameter fields.
We also explore whether the pseudo gap phase can be described without adding
another order parameter field and discuss the potential scaling symmetry
associated with a quantum critical point hidden under the superconducting dome
in this phase diagram.


title: Optimal design of a micro-tubular fuel cell

abstract:
  We discuss the problem of the optimal design of a micro-tubular fuel cell
applying an inverse homogenization technique. Fuel cells are extremely clean
and efficient electrochemical power generation devices, made up of a
cathode/electrolyte/anode structure, whose energetic potential has not being
fully exploited in propulsion systems in aeronautics due to their low power
densities. Nevertheless, thanks to the recent development of additive layer
manufacturing techniques (3D printing), complex structures usually impossible
to design with conventional manufacturing techniques can be constructed with a
low cost, allowing notably to build porous or foam-type structures for fuel
cells. We seek thus to come up with the micro-structure of an arrangement of
micro-tubular cathodes which maximizes the contact surface subject to a
pressure drop and a permeability constraint. The optimal periodic design
(fluid/solid) emerges from the application of a shape gradient algorithm
coupled to a level-set method for the geometrical description of the
corresponding cell problem.


title: Semirings for temporal network analysis

abstract:
  In the article, we describe a new algebraic approach to the temporal network
analysis based on the notion of temporal quantities. We define the semiring for
computing the foremost journey and the traveling semirings for the analysis of
temporal networks where the latency is given, the waiting times are arbitrary,
and some other information on the links are known. We use the operations in the
traveling semiring to compute a generalized temporal betweenness centrality of
the nodes that corresponds to the importance of the nodes with respect to the
ubiquitous foremost journeys in a temporal network.


title: Towards Machine Intelligence

abstract:
  There exists a theory of a single general-purpose learning algorithm which
could explain the principles of its operation. This theory assumes that the
brain has some initial rough architecture, a small library of simple innate
circuits which are prewired at birth and proposes that all significant mental
algorithms can be learned. Given current understanding and observations, this
paper reviews and lists the ingredients of such an algorithm from both
architectural and functional perspectives.


title: Stability of perturbed geodesics in $nD$ axisymmetric spacetimes

abstract:
  The effect of self-gravity of a disk matter is evaluated by the simplest
modes of oscillation frequencies for perturbed circular geodesics. It is
plotted the radial profiles of free oscillations of an equatorial circular
geodesic perturbed within the orbital plane or in the vertical direction. The
calculation is carried out to geodesics of an axisymmetric $n$-dimensional
spacetime. The profiles are computed by examples of disks embeded in
five-dimensional or six-dimensional spacetime, where it is studied the motion
of free test particles for three axisymmetric cases: (i) the Newtonian limit of
a general proposed $5D$ and $6D$ axisymmetric spacetime; (ii) a simple
Randall-Sundrum $5D$ spacetime; (iii) general $5D$ and $6D$ Randall-Sundrum
spacetime. The equation of motion of such particles is derived and the
stability study is computed for both horizontal and vertical directions, to see
how extra dimensions could affect the system. In particular, we investigate a
disk constructed from Schwarzschild and Chazy-Curzon solutions with a simple
extension for extra dimensions in the case (i), and by solving vacuum Einstein
field equations for a kind of Randall-Sundrum-Weyl metric in cases (ii) and
(iii). We find that it is possible to compute a range of possible solutions
where such perturbed geodesics are stable. Basicaly, the stable solutions
appear, for the radial direction, in special cases when the system has $5D$ and
in all cases when the system has $6D$; and, for the axial direction, in all
cases when the system has both $5D$ or $6D$.


title: The Sch\"utzenberger product for syntactic spaces

abstract:
  Starting from Boolean algebras of languages closed under quotients and using
duality theoretic insights, we derive the notion of Boolean spaces with
internal monoids as recognisers for arbitrary formal languages of finite words
over finite alphabets. This leads to a setting that is well-suited for applying
existing tools from Stone duality as applied in semantics. The main focus of
the paper is the development of topo-algebraic constructions pertinent to the
treatment of languages given by logic formulas. In particular, using the
standard semantic view of quantification as projection, we derive a notion of
Sch\"utzenberger product for Boolean spaces with internal monoids. This makes
heavy use of the Vietoris construction, and its dual functor, which is central
to the coalgebraic treatment of classical modal logic. We show that the unary
Sch\"utzenberger product for spaces, when applied to a recogniser for the
language associated to a formula with a free first-order variable, yields a
recogniser for the language of all models of the corresponding existentially
quantified formula. Further, we generalise global and local versions of the
theorems of Sch\"utzenberger and Reutenauer characterising the languages
recognised by the binary Sch\"utzenberger product. Finally, we provide an
equational characterisation of Boolean algebras obtained by local
Sch\"utzenberger product with the one element space based on an Egli-Milner
type condition on generalised factorisations of ultrafilters on words.


title: On positivity of Kauffman bracket skein algebras of surfaces

abstract:
  We show that the Chebyshev polynomials form a basic block of any positive
basis of the Kauffman bracket skein algebras of surfaces.


title:
Ultrafast fluorescent decay induced by metal-mediated dipole-dipole
  interaction in two-dimensional molecular aggregates

abstract:
  Two-dimensional molecular aggregate (2DMA), a thin sheet of strongly
interacting dipole molecules self-assembled at close distance on an ordered
lattice, is a fascinating fluorescent material. It is distinctively different
from the single or colloidal dye molecules or quantum dots in most previous
research. In this paper, we verify for the first time that when a 2DMA is
placed at a nanometric distance from a metallic substrate, the strong and
coherent interaction between the dipoles inside the 2DMA dominates its
fluorescent decay at picosecond timescale. Our streak-camera lifetime
measurement and interacting lattice-dipole calculation reveal that the
metal-mediated dipole-dipole interaction shortens the fluorescent lifetime to
about one half and increases the energy dissipation rate by ten times than
expected from the noninteracting single-dipole picture. Our finding can enrich
our understanding of nanoscale energy transfer in molecular excitonic systems
and may designate a new direction for developing fast and efficient
optoelectronic devices.

categories: physics.optics cond-mat.mes-hall cond-mat.mtrl-sci physics.atm-clus physics.chem-ph


title: Quantum Revivals in Conformal Field Theories in Higher Dimensions

abstract:
  We investigate the behavior of the return amplitude ${\cal F}(t)=
|\langle\Psi(0)|\Psi(t)\rangle|$ following a quantum quench in a conformal
field theory (CFT) on a compact spatial manifold of dimension $d-1$ and linear
size $O(L)$, from a state $|\Psi(0)\rangle$ of extensive energy with
short-range correlations. After an initial gaussian decay ${\cal F}(t)$ reaches
a plateau value related to the density of available states at the initial
energy. However for $d=3,4$ this value is attained from below after a single
oscillation. For a holographic CFT the plateau persists up to times at least
$O(\sigma^{1/(d-1)} L)$, where $\sigma\gg1$ is the dimensionless
Stefan-Boltzmann constant. On the other hand for a free field theory on
manifolds with high symmetry there are typically revivals at times
$t\sim\mbox{integer}\times L$. In particular, on a sphere $S_{d-1}$ of
circumference $2\pi L$, there is an action of the modular group on ${\cal
F}(t)$ implying structure near all rational values of $t/L$, similarly to what
happens for rational CFTs in $d=2$.


title:
Generally Covariant Maxwell Theory for Media with a Local Response:
  Progress since 2000

abstract:
  In the recent decades, it became more and more popular for engineers,
physicists, and mathematicians alike to put the Maxwell equations into a
generally covariant form. This is particularly useful for understanding the
fundamental structure of electrodynamics (conservation of electric charge and
magnetic flux). Moreover, it is ideally suited for applying it to media with
local (and mainly linear) response behavior. We try to collect the new
knowledge that grew out of this development. We would like to ask the
participants of EMTS 2016 to inform us of work that we may have overlooked in
our review.


title: Equivalence of Deterministic walks on regular lattices on the plane

abstract:
  We consider deterministic walks on square, triangular and hexagonal two
dimensional lattices. In each case, there is a scatterer at every site that can
be in one of two states that force the walker to turn either to his/her
immediate right or left. After the walker is scattered, the scatterer changes
state. A lattice with an arrangement of scatterers is an environment. We show
that there are only two environments for which the scattering rules are
injective, mirrors or rotators, on the three lattices. On hexagonal lattices,
B. Z. Webb and E. G. D. Cohen, proved that given an initial position and
velocity of the walker and an environment of one type of scatterers, mirrrors
or rotators, there is an environment of the other type such that the walks on
both environments are equivalent, meaning they visit the same sites at the same
time steps. We prove the equivalence of walks on square and triangular lattices
and include a proof of the equivalence of walks on hexagonal lattices. The
proofs are based both on the geometry of the lattice and the structure of the
scattering rule.


title: Convolutional Networks for Fast, Energy-Efficient Neuromorphic Computing

abstract:
  Deep networks are now able to achieve human-level performance on a broad
spectrum of recognition tasks. Independently, neuromorphic computing has now
demonstrated unprecedented energy-efficiency through a new chip architecture
based on spiking neurons, low precision synapses, and a scalable communication
network. Here, we demonstrate that neuromorphic computing, despite its novel
architectural primitives, can implement deep convolution networks that i)
approach state-of-the-art classification accuracy across 8 standard datasets,
encompassing vision and speech, ii) perform inference while preserving the
hardware's underlying energy-efficiency and high throughput, running on the
aforementioned datasets at between 1200 and 2600 frames per second and using
between 25 and 275 mW (effectively > 6000 frames / sec / W) and iii) can be
specified and trained using backpropagation with the same ease-of-use as
contemporary deep learning. For the first time, the algorithmic power of deep
learning can be merged with the efficiency of neuromorphic processors, bringing
the promise of embedded, intelligent, brain-inspired computing one step closer.


title:
On Sharpness of the Local Kato Smoothing Property of Dispersive Wave
  Equations

abstract:
  Constantin and Saut showed in 1988 that solutions of the Cauchy problem for
general dispersive equations $$
  w_t +iP(D)w=0,\quad w(x,0)=q (x), \quad x\in \mathbb{R}^n, \ t\in \mathbb{R}
, $$ enjoy the local smoothing property $$ q\in H^s (\R ^n) \implies w\in L^2
\Big (-T,T; H^{s+\frac{m-1}{2}}_{loc} \left (\R^n\right )\Big ) , $$ where $m$
is the order of the pseudo-differential operator $P(D)$. This property, now
called local Kato smoothing, was first discovered by Kato for the KdV equation
and implicitly shown later by Sj\"olin for the linear Schr\"odinger equation.
In this paper, we show that the local Kato smoothing property possessed by
solutions general dispersive equations in the 1D case is sharp, meaning that
there exist initial data $q\in H^s \left (\R \right )$ such that the
corresponding solution $w$ does not belong to the space $ L^2 \Big (-T,T;
H^{s+\frac{m-1}{2} +\epsilon}_{loc} \left (\R\right )\Big )$ for any $\epsilon
>0$.


title: Interstellar chemical differentiation across grain sizes

abstract:
  In this work we investigate the effects of ion accretion and size-dependent
dust temperatures on the abundances of both gas-phase and grain-surface
species. While past work has assumed a constant areal density for icy species,
we show that this assumption is invalid and the chemical differentiation over
grain sizes are significant. We use a gas-grain chemical code to numerically
demonstrate this in two typical interstellar conditions: dark cloud (DC) and
cold neutral medium (CNM). It is shown that, although the grain size
distribution variation (but with the total grain surface area unchanged) has
little effect on the gas-phase abundances, it can alter the abundances of some
surface species by factors up to $\sim2-4$ orders of magnitude. The areal
densities of ice species are larger on smaller grains in the DC model as the
consequence of ion accretion. However, the surface areal density evolution
tracks are more complex in the CNM model due to the combined effects of ion
accretion and dust temperature variation. The surface areal density differences
between the smallest ($\sim 0.01\mu$m) and the biggest ($\sim 0.2\mu$m) grains
can reach $\sim$1 and $\sim$5 orders of magnitude in the DC and CNM models,
respectively.


title:
Collective Influence Algorithm to find influencers via optimal
  percolation in massively large social media

abstract:
  We elaborate on a linear time implementation of the Collective Influence (CI)
algorithm introduced by Morone, Makse, Nature 524, 65 (2015) to find the
minimal set of influencers in a network via optimal percolation. We show that
the computational complexity of CI is O(N log N) when removing nodes
one-by-one, with N the number of nodes. This is made possible by using an
appropriate data structure to process the CI values, and by the finite radius l
of the CI sphere. Furthermore, we introduce a simple extension of CI when l is
infinite, the CI propagation (CI_P) algorithm, that considers the global
optimization of influence via message passing in the whole network and
identifies a slightly smaller fraction of influencers than CI. Remarkably, CI_P
is able to reproduce the exact analytical optimal percolation threshold
obtained by Bau, Wormald, Random Struct. Alg. 21, 397 (2002) for cubic random
regular graphs, leaving little improvement left for random graphs. We also
introduce the Collective Immunization Belief Propagation algorithm (CI_BP), a
belief-propagation (BP) variant of CI based on optimal immunization, which has
the same performance as CI_P. However, this small augmented performance of the
order of 1-2 % in the low influencers tail comes at the expense of increasing
the computational complexity from O(N log N) to O(N^2 log N), rendering both,
CI_P and CI_BP, prohibitive for finding influencers in modern-day big-data. The
same nonlinear running time drawback pertains to a recently introduced
BP-decimation (BPD) algorithm by Mugisha, Zhou, arXiv:1603.05781. For instance,
we show that for big-data social networks of typically 200 million users (eg,
active Twitter users sending 500 million tweets per day), CI finds the
influencers in less than 3 hours running on a single CPU, while the BP
algorithms (CI_P, CI_BP and BDP) would take more than 3,000 years to accomplish
the same task.

categories: physics.soc-ph cond-mat.dis-nn cond-mat.stat-mech cs.SI


title:
First and second order necessary conditions for stochastic optimal
  controls

abstract:
  The main purpose of this paper is to establish the first and second order
necessary optimality conditions for stochastic optimal controls using the
classical variational analysis approach. The control system is governed by a
stochastic differential equation, in which both drift and diffusion terms may
contain the control variable and the set of controls is allowed to be
nonconvex. Only one adjoint equation is introduced to derive the first order
necessary condition; while only two adjoint equations are needed to state the
second order necessary conditions for stochastic optimal controls.


title:
Krein's trace formula for unitary operators and operator Lipschitz
  functions

abstract:
  The main result of the paper is a description of the class of functions on
the unit circle, for which Krein's trace formula holds for arbitrary pairs of
unitary operators with trace class difference. We prove that this class of
functions coincides with the class of operator Lipschitz functions.


title:
Progress in Many Body Theory with the Equation of Motion method. Time
  dependent Density Matrix meets Self-Consistent RPA. Applications to solvable
  Models

abstract:
  The Bogoliubov-Born-Green-Kirkwood-Yvon or Time-Dependent Density Matrix
(TDDM) hierarchy of equations for higher density matrices is truncated at the
three body level in approximating the three body correlation function by a
quadratic form of two body ones, closing the equations in this way. The
procedure is discussed in detail and it is shown in non-trivial model cases
that the approximate inclusion of three body correlation functions is very
important to obtain precise results. A small amplitude approximation of this
time dependent nonlinear equation for the two body correlation function is
performed (STDDM*-b) and it is shown that the one body sector of this
generalised non-linear second RPA equation is equivalent to the Self-Consistent
RPA (SCRPA) approach which had been derived previously by different techniques.
It is discussed in which way SCRPA also contains the three body correlations.
TDDM and SCRPA are tested versus exactly solvable model cases.


title: Nonlinear waves in electromigration dispersion in a capillary

abstract:
  We construct exact solutions to an unusual nonlinear advection--diffusion
equation arising in the study of Taylor--Aris (also known as shear) dispersion
due to electroosmotic flow during electromigration in a capillary. An exact
reduction to a Darboux equation is found under a traveling-wave anzats. The
equilibria of this ordinary differential equation are analyzed, showing that
their stability is determined solely by the (dimensionless) wave speed without
regard to any (dimensionless) physical parameters. Integral curves, connecting
the appropriate equilibria of the Darboux equation that governs traveling
waves, are constructed, which in turn are shown to be asymmetric kink solutions
({\it i.e.}, non-Taylor shocks). Furthermore, it is shown that the governing
Darboux equation exhibits bistability, which leads to two coexisting
non-negative kink solutions for (dimensionless) wave speeds greater than unity.
Finally, we give some remarks on other types of traveling-wave solutions and a
discussion of some approximations of the governing partial differential
equation of electromigration dispersion.


title:
Phase diagrams and ordering in charged membranes: Binary mixtures of
  charged and neutral lipids

abstract:
  We propose a model describing the phase behavior of two-component membranes
consisting of binary mixtures of electrically charged and neutral lipids. We
take into account the structural phase transition (main-transition) of the
hydrocarbon chains, and investigate the interplay between this phase transition
and the lateral phase separation. The presence of charged lipids significantly
affects the phase behavior of the multi-component membrane. Due to the
conservation of lipid molecular volume, the main-transition temperature of
charged lipids is lower than that of neutral ones. Furthermore, as compared
with binary mixtures of neutral lipids, the membrane phase separation in binary
mixtures of charged lipids is suppressed, in accord with recent experiments. We
distinguish between two types of charged membranes: mixtures of charged
saturated lipid/neutral unsaturated lipid and a second case of mixtures of
neutral saturated lipid/charged unsaturated lipid. The corresponding phase
behavior is calculated and shown to be very different. Finally, we discuss the
effect of added salt on the phase separation and the temperature dependence of
the lipid molecular area.

categories: cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech physics.bio-ph physics.chem-ph


title:
Small Ball Probabilities for the Infinite-Dimensional Ornstein-Uhlenbeck
  Process in Sobolev Spaces

abstract:
  While small ball, or lower tail, asymptotic for Gaussian measures generated
by solutions of stochastic ordinary differential equations is relatively well
understood, a lot less is known in the case of stochastic partial differential
equations. The paper presents exact logarithmic asymptotics of the small ball
probabilities in a scale of Sobolev spaces when the Gaussian measure is
generated by the solution of a diagonalizable stochastic parabolic equation.
  Compared to the finite-dimensional case, new effects appear in a certain
range of the Sobolev exponents.


title:
Electric-field modulation of exchange stiffness in MgO/CoFeB with
  perpendicular anisotropy

abstract:
  We observe magnetic domain structures of MgO/CoFeB with a perpendicular
magnetic easy axis under an electric field. The domain structure shows a maze
pattern with electric-field dependent isotropic period. We find that the
electric-field modulation of the period is explained by considering the
electric-field modulation of the exchange stiffness constant in addition to the
known magnetic anisotropy modulation.


title: Off-diagonal decay of toric Bergman kernels

abstract:
  We study the off-diagonal decay of Bergman kernels $\Pi_{h^k}(z,w)$ and
Berezin kernels $P_{h^k}(z,w)$ for ample invariant line bundles over compact
toric projective \kahler manifolds of dimension $m$. When the metric is real
analytic, $P_{h^k}(z,w) \simeq k^m \exp - k D(z,w)$ where $D(z,w)$ is the
diastasis. When the metric is only $C^{\infty}$ this asymptotic cannot hold for
all $(z,w)$ since the diastasis is not even defined for all $(z,w)$ close to
the diagonal. We prove that for general $C^{\infty}$ metrics, $P_{h^k}(z,w)
\simeq k^m \exp - k D(z,w)$ as long as $w$ lies on the ${\mathbb R}_+^m$-orbit
of $z$, and for general $(z,w)$, $\limsup_{k \to \infty} \frac{1}{k} \log
P_{h^k}(z,w)
  \leq - D(z^*,w^*)$ where $D(z, w^*)$ is the diastasis between $z$ and the
translate of $w$ by $(S^1)^m$ to the ${\mathbb R}_+^m$ orbit of $z$,
complementary to Mike Christ's negative results (arXiv:1308.5644).


title: Construction of Three-Qubit Kochen-Specker Sets

abstract:
  Contextuality is one of the fundamental deviations of quantum mechanics from
classical physics. The Kochen-Specker (KS) theorem shows that non-contextual
classical physics with hidden variables is inconsistent with the predictions of
quantum mechanics. Parity proof is one of the many different approaches applied
to prove KS theorem for quantum system with different dimensionality. This
method of proof requires KS sets that composed of an odd number of bases and an
even number of projectors. In most of the cases, the number of KS sets produced
is large and its production is generally aided by computer calculation.
However, manually generation of KS sets are also reported previously for qutrit
and two-qubit systems. We put forward the first and surprisingly simple method
to generate manually KS sets, with respect to Mermin pentagram, that can be
used for the parity proof of KS theorem in a state space of eight-dimensional
three-qubit system .


title:
The unimodality of the Ehrhart $\delta$-polynomial of the chain polytope
  of the zig-zag poset

abstract:
  We prove the unimodality of the Ehrhart $\delta$-polynomial of the chain
polytope of the zig-zag poset, which was conjectured by Kirillov. First, based
on a result due to Stanley, we show that this polynomial coincides with the
$W$-polynomial for the zig-zag poset with some natural labeling. Then, its
unimodality immediately follows from a result of Gasharov, which states that
the $W$-polynomials of naturally labeled graded posets of rank $1$ or $2$ are
unimodal.


title: Topology of holomorphic Lefschetz pencils on the four-torus

abstract:
  In this paper we discuss topological properties of holomorphic Lefschetz
pencils on the four-torus. Relying on the theory of moduli spaces of polarized
abelian surfaces, we first prove that, under some mild assumption, the (smooth)
isomorphism class of a holomorphic Lefschetz pencil on the four-torus is
uniquely determined by its genus and divisibility. We then explicitly give a
system of vanishing cycles of the genus-3 holomorphic Lefschetz pencil on the
four-torus due to Smith, and obtain those of holomorphic pencils with higher
genera by taking finite unbranched coverings. One can also obtain the monodromy
factorization associated with Smith's pencil in a combinatorial way. This
construction allows us to generalize Smith's pencil to higher genera, which is
a good source of pencils on the (topological) four-torus. As another
application of the combinatorial construction, for any torus bundle over the
torus with a section we construct a genus-3 Lefschetz pencil whose total space
is homeomorphic to that of the given bundle.


title: Voltage Controlled Interfacial Layering in an Ionic Liquid on SrTiO$_3$

abstract:
  One prominent structural feature of ionic liquids near surfaces is formation
of alternating layers of anions and cations. However, how this layering
responds to applied potential is poorly understood. We focus on the structure
of 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate
(BMPY-FAP) near the surface of a strontium titanate (SrTiO$_3$) electric
double-layer transistor. Using x-ray reflectivity, we show that at positive
bias, the individual layers in the ionic liquid double layer thicken and the
layering persists further away from the interface. We model the reflectivity
using a modified distorted crystal model with alternating cation and anion
layers, which allows us to extract the charge density and the potential near
the surface. We find that the charge density is strongly oscillatory with and
without applied potential, and that with applied gate bias of 4.5 V the first
two layers become significantly more cation rich than at zero bias,
accumulating about $2.5 \times 10^{13}$ cm$^{-2}$ excess charge density.


title:
Mechanism for the Large Conductance Modulation in Electrolyte-gated Thin
  Gold Films

abstract:
  Electrolyte gating using ionic liquid electrolytes has recently generated
considerable interest as a method to achieve large carrier density modulations
in a variety of materials. In noble metal thin films, electrolyte gating
results in large changes in sheet resistance. The widely accepted mechanism for
these changes is the formation of an electric double layer with a charged layer
of ions in the liquid and accumulation or depletion of carriers in the thin
film. We report here a different mechanism. In particular, we show using x-ray
absorption near edge structure (XANES) that the previously reported large
conductance modulation in gold films is due to reversible oxidation and
reduction of the surface rather than the charging of an electric double layer.
We show that the double layer capacitance accounts for less than 10\% of the
observed change in transport properties. These results represent a significant
step towards understanding the mechanisms involved in electrolyte gating.


title:
Atomic Response in the Near-field of Nanostructured Plasmonic
  Metamaterial

abstract:
  We report on reflection spectra of caesium atoms in close vicinity of a
nanostructured metallic meta-surface. We show that the hyperfine sub-Doppler
spectrum of the $6S_{1/2} - 6P_{3/2}$ resonance transition at 852 nm is
strongly affected by the coupling to the plasmonic resonance of the
nanostructure. Fine tuning of dispersion and positions of the atomic lines in
the near-field of plasmonic metamaterials could have uses and implications for
the atom-based metrology, sensing and the development of atom-on-a-chip
devices.


title:
The optical/UV excess of X-ray dim isolated neutron star: I.
  bremsstrahlung emission from a strangeon star plasma atmosphere

abstract:
  X-ray dim isolated neutron stars (XDINSs) are characterized by Planckian
spectra in X-ray bands, but show optical/ultraviolet(UV) excesses which are the
measured photometry exceeding that is extrapolated from X-ray spectra. To solve
this problem, a radiative model of bremsstrahlung emission from a plasma
atmosphere is established in the regime of strangeon star. A strangeon star
atmosphere could simply be regarded as the upper layer of a normal neutron
star. This plasma atmosphere, formed and maintained by the ISM-accreted matter
due to the so-called strangeness barrier, is supposed to be of two-temperature.
All the seven XDINS spectra could be well fitted by the radiative model, from
optical/UV to X-ray bands. The fitted radiation radii of XDINSs are from 7 to
13km, while the modelled electron temperatures are between 50 and 250eV, except
RX J0806.4-4123 with a radiation radius ~3.5km, indicating that this source
could be a low-mass strangeon star candidate. This strangeon star model could
further be tested by soft X-ray polarimetry, such as the Lightweight Asymmetry
and Magnetism Probe which is expected to work on Chinese space station around
2020.


title:
Pricing variance swaps in a hybrid model of stochastic volatility and
  interest rate with regime-switching

abstract:
  In this paper, we consider the problem of pricing discretely-sampled variance
swaps based on a hybrid model of stochastic volatility and stochastic interest
rate with regime-switching. Our modelling framework extends the Heston
stochastic volatility model by including the CIR stochastic interest rate and
model parameters that switch according to a continuous-time observable Markov
chain process. A semi-closed form pricing formula for variance swaps is
derived. The pricing formula is assessed through numerical implementations, and
the impact of including regime-switching on pricing variance swaps is also
discussed.


title:
Partial condition number for the equality constrained linear least
  squares problem

abstract:
  In this paper, the normwise condition number of a linear function of the
equality constrained linear least squares solution called the partial condition
number is considered. Its expression and closed formulae are first presented
when the data space and the solution space are measured by the weighted
Frobenius norm and the Euclidean norm, respectively. Then, we investigate the
corresponding structured partial condition number when the problem is
structured. To estimate these condition numbers with high reliability, the
probabilistic spectral norm estimator and the small-sample statistical
condition estimation method are applied and two algorithms are devised. The
obtained results are illustrated by numerical examples.


title:
Prospects for Reconstruction of Leptonic Unitarity Quadrangle and
  Neutrino Oscillation Experiments

abstract:
  After the observation of non-zero $\theta_{13}$ the goal has shifted to
observe $CP$ violation in the leptonic sector. Neutrino oscillation experiments
can, directly, probe the Dirac $CP$ phases. Alternatively, one can measure $CP$
violation in the leptonic sector using Leptonic Unitarity Quadrangle(LUQ). The
existence of Standard Model (SM) gauge singlets - sterile neutrinos - will
provide additional sources of $CP$ violation. We investigate the connection
between neutrino survival probability and rephasing invariants of the
$4\times4$ neutrino mixing matrix. In general, LUQ contain eight geometrical
parameters out of which five are independent. We obtain $CP$
asymmetry($P_{\nu_f\rightarrow\nu_{f'}}-P_{\bar{\nu}_f\rightarrow\bar{\nu}_{f'}}$)
in terms of these independent parameters of the LUQ and search for the
possibilities of extracting information on these independent geometrical
parameters in short baseline(SBL) and long baseline(LBL) experiments, thus,
looking for constructing LUQ and possible measurement of $CP$ violation. We
find that it is not possible to construct LUQ using data from LBL experiments
because $CP$ asymmetry is sensitive to only three of the five independent
parameters of LUQ. However, for SBL experiments, $CP$ asymmetry is found to be
sensitive to all five independent parameters making it possible to construct
LUQ and measure $CP$ violation.


title: Inclusive three jet production at the LHC as a new BFKL probe

abstract:
  We discuss recently proposed observables, sensitive to BFKL dynamics, in the
context of multijet production at the large hadron collider (LHC). In
particular, we consider ratios of azimuthal angle differences in final states
with three jets, well separated in rapidity from each other, with two of them
being very forward/backward and the third one in the central region.


title: Non-Greedy L21-Norm Maximization for Principal Component Analysis

abstract:
  Principal Component Analysis (PCA) is one of the most important unsupervised
methods to handle high-dimensional data. However, due to the high computational
complexity of its eigen decomposition solution, it hard to apply PCA to the
large-scale data with high dimensionality. Meanwhile, the squared L2-norm based
objective makes it sensitive to data outliers. In recent research, the L1-norm
maximization based PCA method was proposed for efficient computation and being
robust to outliers. However, this work used a greedy strategy to solve the
eigen vectors. Moreover, the L1-norm maximization based objective may not be
the correct robust PCA formulation, because it loses the theoretical connection
to the minimization of data reconstruction error, which is one of the most
important intuitions and goals of PCA. In this paper, we propose to maximize
the L21-norm based robust PCA objective, which is theoretically connected to
the minimization of reconstruction error. More importantly, we propose the
efficient non-greedy optimization algorithms to solve our objective and the
more general L21-norm maximization problem with theoretically guaranteed
convergence. Experimental results on real world data sets show the
effectiveness of the proposed method for principal component analysis.


title: Update on 750 GeV diphotons from closed string states

abstract:
  Motivated by the recent update on LHC searches for narrow and broad
resonances decaying into diphotons we reconsider the possibility that the
observed peak in the invariant mass spectrum at M_{\gamma \gamma} = 750 GeV
originates from a closed string (possibly axionic) excitation \varphi
(associated with low mass scale string theory) that has a coupling with gauge
kinetic terms. We reevaluate the production of \varphi by photon fusion to
accommodate recent developments on additional contributions to relativistic
light-light scattering. We also study the production of \varphi via gluon
fusion. We show that for both a narrow and a broad resonance these two initial
topologies can accommodate the excess of events, spanning a wide range of
string mass scales 7 \alt M_s/TeV \alt 30 that are consistent with the
experimental lower bound: M_s > 7 TeV, at 95% CL. We demonstrate that for the
two production processes the LHC13 data is compatible with the lack of a
diphoton excess in LHC8 data within \sim 1\sigma. We also show that if the
resonance production is dominated by gluon fusion the null results on dijet
searches at LHC8 further constrain the coupling strengths of \varphi, but
without altering the range of possible string mass scales.


title:
Heat pump without particle transport or external work on the medium
  achieved by differential thermostatting of the phase space

abstract:
  We propose a new mechanism that enables heat flow from a colder region to a
hotter region without necessitating either particle transport or external work
on the conductor, thereby bypassing the compressor part of a classical heat
pump cycle. Our mechanism relies on thermostatting the kinetic and
configurational temperatures of the same particle differently. We keep the two
ends of a conductor, which in the present study is a single dimensional
$\phi^4$ chain, at the same kinetic temperature $T_0$, but at different
configurational temperatures - one end hotter and the other end colder than
$T_0$. While external energy is needed within the thermostatted regions to
achieve this differential thermostatting, no external work is performed on the
system itself. We show that the mechanism satisfies the statistical form of the
second law of thermodynamics (the fluctuation theorem). The proposed mechanism
reveals two interesting findings - (i) contrary to traditional thermodynamics
where only the kinetic temperature is thought to govern heat conduction,
configurational temperature can also play an important role, and (ii) the
relative temperature difference between the kinetic and configurational
variables governs the direction of heat flow. The challenge, however, is in
developing experimental techniques to thermostat the kinetic and
configurational variables of the same particle at different values.


title: The SVM Classifier Based on the Modified Particle Swarm Optimization

abstract:
  The problem of development of the SVM classifier based on the modified
particle swarm optimization has been considered. This algorithm carries out the
simultaneous search of the kernel function type, values of the kernel function
parameters and value of the regularization parameter for the SVM classifier.
Such SVM classifier provides the high quality of data classification. The idea
of particles' {\guillemotleft}regeneration{\guillemotright} is put on the basis
of the modified particle swarm optimization algorithm. At the realization of
this idea, some particles change their kernel function type to the one which
corresponds to the particle with the best value of the classification accuracy.
The offered particle swarm optimization algorithm allows reducing the time
expenditures for development of the SVM classifier. The results of experimental
studies confirm the efficiency of this algorithm.


title: Development of System Architecture for E-Government Cloud Platforms

abstract:
  Requirements and criteria for selection of cloud platform and platform
visualization are stated by which optimal cloud products will be chosen for the
Republic of Kazakhstan e-Government considering quality-price ratio, and also
the framework of information and communication architecture will be introduced.


title: Note on limit distribution of normalized return times and escape rate

abstract:
  In this note we discuss limit distribution of normalized return times for
shrinking targets and draw a necessary and sufficient condition using sweep-out
sequence in order for the limit distribution to be exponential with parameter
$1$. The normalizing coefficients are the same as sizes of the targets.
Moreover we study escape rate, namely the exponential decay rate of sweep-out
sequence and prove that in $\psi$-mixing systems for a certain class of sets
the escape rate is in limit proportional to the size of the set.


title:
Dark Matter and Dark Energy Interactions: Theoretical Challenges,
  Cosmological Implications and Observational Signatures

abstract:
  Models where Dark Matter and Dark Energy interact with each other have been
proposed to solve the coincidence problem. We review the motivations underlying
the need to introduce such interaction, its influence on the background
dynamics and how it modifies the evolution of linear perturbations. We test
models using the most recent observational data and we find that the
interaction is compatible with the current astronomical and cosmological data.
Finally, we describe the forthcoming data sets from current and future
facilities that are being constructed or designed that will allow a clearer
understanding of the physics of the dark sector.


title:
A Stochastic Model for Quantitative Security Analyses of Networked
  Systems

abstract:
  Traditional security analyses are often geared towards cryptographic
primitives or protocols. Although such analyses are necessary, they cannot
address a defender's need for insight into {\em which aspects of a networked
system having a significant impact on its security, and how to tune its
configurations or parameters so as to improve security}. This question is known
to be notoriously difficult to answer, and the state-of-the-art is that we know
little about it. Towards ultimately addressing this question, this paper
presents a stochastic model for quantifying security of networked systems. The
resulting model captures two aspects of a networked system: (1) the strength of
deployed security mechanisms such as intrusion detection systems, and (2) the
underlying {\em vulnerability graph}, which reflects how attacks may proceed.
The resulting model brings the following insights: (1) How should a defender
"tune" system configurations (e.g., network topology) so as to improve
security? (2) How should a defender "tune" system parameters (e.g., by
upgrading which security mechanisms) so as to improve security? (3) Under what
conditions is the steady-state number of compromised entities of interest below
a given threshold with a high probability? Simulation studies are conducted to
confirm the analytic results, and to show the tightness of the bounds of
certain important metric that cannot be resolved analytically.


title:
Global well-posedness for the 2D Boussinesq Equations with Zero
  Viscosity

abstract:
  We prove the global well-posedness of the two-dimensional Boussinesq
equations with zero viscosity and positive diffusivity in bounded domains for
rough initial data [ $u_{0}\in L^{2}$, $\text{curl}\,u_{0}\in L^{\infty}$ and
$\theta_{0}\in B^{2-2/p}_{q,p}$ with $p\in (1,\infty)$, $q\in (2,\infty)$ ].
Our method is based on the maximal regularity for heat equation.


title:
The Dubna-Mainz-Taipei Dynamical Model for $\pi N$ Scattering and $\pi$
  Electromagnetic Production

abstract:
  Some of the featured results of the Dubna-Mainz-Taipei (DMT) dynamical model
for $\pi N$ scattering and $\pi^0$ electromagnetic production are summarized.
These include results for threshold $\pi^0$ production, deformation of
$\Delta(1232)$, and the extracted properties of higher resonances below 2 GeV.
The excellent agreement of DMT model's predictions with threshold $\pi^0$
production data, including the recent precision measurements from MAMI
establishes results of DMT model as a benchmark for experimentalists and
theorists in dealing with threshold pion production.


title: Three axis vector atomic magnetometer utilizing polarimetric technique

abstract:
  The three axis magnetic field measurement based on the interaction of a
single elliptically polarized light beam with an atomic system is described.
The magnetic field direction dependent atomic responses are extracted by the
polarimetric detection in combination with laser frequency modulation and
magnetic field modulation techniques. The magnetometer offers additional
critical requirements like compact size and large dynamic range for space
application. Further, the three axis magnetic field is measured using only
reflected signal from the polarimeter, thus can be easily expanded to make
spatial array of detectors or / and high sensitivity field gradient measurement
as required for biomedical application.


title:
An Extended Stochastic Model for Quantitative Security Analysis of
  Networked Systems

abstract:
  Quantitative security analysis of networked computer systems is one of the
decades-long open problems in computer security. Recently, a promising approach
was proposed in \cite{XuTDSC11}, which however made some strong assumptions
including the exponential distribution of, and the independence between, the
relevant random variables. In this paper, we substantially weaken these
assumptions while offering, in addition to the same types of analytical results
as in \cite{XuTDSC11}, methods for obtaining the desired security quantities in
practice. Moreover, we investigate the problem from a higher-level abstraction,
which also leads to both analytical results and practical methods for obtaining
the desired security quantities. These would represent a significant step
toward ultimately solving the problem of quantitative security analysis of
networked computer systems.


title: A New Approach to Modeling and Analyzing Security of Networked Systems

abstract:
  Modeling and analyzing security of networked systems is an important problem
in the emerging Science of Security and has been under active investigation. In
this paper, we propose a new approach towards tackling the problem. Our
approach is inspired by the {\em shock model} and {\em random environment}
techniques in the Theory of Reliability, while accommodating security
ingredients. To the best of our knowledge, our model is the first that can
accommodate a certain degree of {\em adaptiveness of attacks}, which
substantially weakens the often-made independence and exponential attack
inter-arrival time assumptions. The approach leads to a stochastic process
model with two security metrics, and we attain some analytic results in terms
of the security metrics.


title: Field Theoretic Approaches To Early Universe

abstract:
  This thesis compiles the results of six works which deal with - inflationary
model building and estimation of cosmological parameters from various field
theoretic setup, quantification of reheating temperature, studies of
leptogenesis in braneworld and estimation of primordial non-Gaussianity from
${\cal N}=1$ supergravity using $\delta N$ formalism. We start our discussion
with exploring the possibility of MSSM inflation in the light of recent
observed data from various D -flat directions using the saddle and inflection
point techniques. The effective inflaton potential around saddle point and
inflection point have been utilized in estimating the observable parameters and
confronting them with WMAP7 and Planck dataset. Next we explore the possibility
of inflation from the five dimensional ${\cal N} = 2$ supergravity setup by
deriving the effective potential in the context of RS like braneworld model and
DBI Galileon. After deriving an four dimensional effective potential, we obtain
the inflationary observables from both the scenarios and confront them with the
WMAP data. Further we fit the CMB angular power spectra from TT anisotropy and
other polarization data obtained from WMAP. Further, we discuss the non-trivial
features of reheating from supergravity inspired braneworld model, where the
results are to some extent different from that of the usual low energy GR
counterpart, because of the modified Friedmann equations in this setup. We
explicitly derive the analytical expressions for the reheating temperature and
further solve the evolution equation of the number density of thermal gravitino
which results in the gravitino abundance. Finally, we study the primordial
local type of non-Gaussian features using $\delta N$ formalism for a generic
class of sub-Planckian models dominated by the Hubble-induced corrections
within ${\cal N} = 1$ supergravity framework.


title: Cyber Epidemic Models with Dependences

abstract:
  Studying models of cyber epidemics over arbitrary complex networks can deepen
our understanding of cyber security from a whole-system perspective. In this
paper, we initiate the investigation of cyber epidemic models that accommodate
the {\em dependences} between the cyber attack events. Due to the notorious
difficulty in dealing with such dependences, essentially all existing cyber
epidemic models have assumed them away. Specifically, we introduce the idea of
Copulas into cyber epidemic models for accommodating the dependences between
the cyber attack events. We investigate the epidemic equilibrium thresholds as
well as the bounds for both equilibrium and non-equilibrium infection
probabilities. We further characterize the side-effects of assuming away the
due dependences between the cyber attack events, by showing that the results
thereof are unnecessarily restrictive or even incorrect.


title: A Data-driven Study of View Duration on YouTube

abstract:
  Video watching had emerged as one of the most frequent media activities on
the Internet. Yet, little is known about how users watch online video. Using
two distinct YouTube datasets, a set of random YouTube videos crawled from the
Web and a set of videos watched by participants tracked by a Chrome extension,
we examine whether and how indicators of collective preferences and reactions
are associated with view duration of videos. We show that video view duration
is positively associated with the video's view count, the number of likes per
view, and the negative sentiment in the comments. These metrics and reactions
have a significant predictive power over the duration the video is watched by
individuals. Our findings provide a more precise understandings of user
engagement with video content in social media beyond view count.


title: A Stochastic Model of Active Cyber Defense Dynamics

abstract:
  The concept of active cyber defense has been proposed for years. However,
there are no mathematical models for characterizing the effectiveness of active
cyber defense. In this paper, we fill the void by proposing a novel Markov
process model that is native to the interaction between cyber attack and active
cyber defense. Unfortunately, the native Markov process model cannot be tackled
by the techniques we are aware of. We therefore simplify, via mean-field
approximation, the Markov process model as a Dynamic System model that is
amenable to analysis. This allows us to derive a set of valuable analytical
results that characterize the effectiveness of four types of active cyber
defense dynamics. Simulations show that the analytical results are inherent to
the native Markov process model, and therefore justify the validity of the
Dynamic System model. We also discuss the side-effect of the mean-field
approximation and its implications.


title: On chromatic functors and stable partitions of graphs

abstract:
  The chromatic functor of a simple graph is a functorization of the chromatic
polynomial. M. Yoshinaga showed in \cite{Yoshinaga2015} that two finite graphs
have isomorphic chromatic functors if and only if they have the same chromatic
polynomial. The key ingredient in the proof is the use of stable partitions of
graphs. The latter is shown to be closely related to chromatic functors. In
this note, we further investigate some interesting properties of chromatic
functors associated to simple graphs using stable partitions. Our first result
is the determination of the group of natural automorphisms of the chromatic
functor, which is in general a larger group than the automorphism group of the
graph. The second result is that the composition of the chromatic functor
associated to a finite graph restricted to the category $\mathrm{FI}$ of finite
sets and injections with the free functor into the category of complex vector
spaces yields a consistent sequence of representations of symmetric groups
which is representation stable in the sense of Church-Farb \cite{Church2013}.


title: Interest Rates and Inflation

abstract:
  This article is an extension of the work of one of us (Coopersmith, 2011) in
deriving the relationship between certain interest rates and the inflation rate
of a two component economic system. We use the well-known Fisher relation
between the difference of the nominal interest rate and its inflation adjusted
value to eliminate the inflation rate and obtain a delay differential equation.
We provide computer simulated solutions for this equation over regimes of
interest. This paper could be of interest to three audiences: those in
Economics who are interested in interest and inflation; those in Mathematics
who are interested in examining a detailed analysis of a delay differential
equation, which includes a summary of existing results, simulations, and an
exact solution; and those in Physics who are interested in non-traditional
applications of traditional methods of modeling.


title: Optimizing Active Cyber Defense

abstract:
  Active cyber defense is one important defensive method for combating cyber
attacks. Unlike traditional defensive methods such as firewall-based filtering
and anti-malware tools, active cyber defense is based on spreading "white" or
"benign" worms to combat against the attackers' malwares (i.e., malicious
worms) that also spread over the network. In this paper, we initiate the study
of {\em optimal} active cyber defense in the setting of strategic attackers
and/or strategic defenders. Specifically, we investigate infinite-time horizon
optimal control and fast optimal control for strategic defenders (who want to
minimize their cost) against non-strategic attackers (who do not consider the
issue of cost). We also investigate the Nash equilibria for strategic defenders
and attackers. We discuss the cyber security meanings/implications of the
theoretic results. Our study brings interesting open problems for future
research.


title: Dilaton Stabilization in Three-generation Heterotic String Model

abstract:
  We study dilaton stabilization in heterotic string models. By utilizing the
asymmetric orbifold construction, we construct an explicit three-generation
model whose matter content in the visible sector is the supersymmetric standard
model with additional vectorlike matter. This model does not contain any
geometric moduli fields except the dilaton field. Model building at a symmetry
enhancement point in moduli space enlarges the rank of the hidden gauge group.
By analyzing multiple hidden gauge sectors, the dilaton field is stabilized by
the racetrack mechanism. We also discuss a supersymmetry breaking scenario and
F-term uplifting.


title: Active Cyber Defense Dynamics Exhibiting Rich Phenomena

abstract:
  The Internet is a man-made complex system under constant attacks (e.g.,
Advanced Persistent Threats and malwares). It is therefore important to
understand the phenomena that can be induced by the interaction between cyber
attacks and cyber defenses. In this paper, we explore the rich phenomena that
can be exhibited when the defender employs active defense to combat cyber
attacks. To the best of our knowledge, this is the first study that shows that
{\em active cyber defense dynamics} (or more generally, {\em cybersecurity
dynamics}) can exhibit the bifurcation and chaos phenomena. This has profound
implications for cyber security measurement and prediction: (i) it is
infeasible (or even impossible) to accurately measure and predict cyber
security under certain circumstances; (ii) the defender must manipulate the
dynamics to avoid such {\em unmanageable situations} in real-life defense
operations.

categories: cs.CR cs.SI cs.SY math.DS physics.soc-ph


title:
A Shrinkage Principle for Heavy-Tailed Data: High-Dimensional Robust
  Low-Rank Matrix Recovery

abstract:
  This paper introduces a simple principle for robust high-dimensional
statistical inference via an appropriate shrinkage on the data. This widens the
scope of high-dimensional techniques, reducing the moment conditions from
sub-exponential or sub-Gaussian distributions to merely bounded second or
fourth moment. As an illustration of this principle, we focus on robust
estimation of the low-rank matrix $\Theta^*$ from the trace regression model
$Y=Tr (\Theta^{*T}X) +\epsilon$. It encompasses four popular problems: sparse
linear models, compressed sensing, matrix completion and multi-task regression.
We propose to apply penalized least-squares approach to appropriately truncated
or shrunk data. Under only bounded $2+\delta$ moment condition on the response,
the proposed robust methodology yields an estimator that possesses the same
statistical error rates as previous literature with sub-Gaussian errors. For
sparse linear models and multi-tasking regression, we further allow the design
to have only bounded fourth moment and obtain the same statistical rates,
again, by appropriate shrinkage of the design matrix. As a byproduct, we give a
robust covariance matrix estimator and establish its concentration inequality
in terms of the spectral norm when the random samples have only bounded fourth
moment. Extensive simulations have been carried out to support our theories.


title:
Endoscopic lifting of simple supercuspidal representations of unramified
  U(N) to GL(N)

abstract:
  Let U(N) be the quasi-split unitary group in N variables for a quadratic
unramified extension of p-adic fields. We compute the characters of simple
supercuspidal representations of twisted GL(N) and U(N). Comparing them by the
endoscopic character relation, we determine the liftings of simple
supercuspidal representations of U(N) to GL(N), under the assumption that p is
not equal to 2.


title:
Conditions for achieving invisibility of hyperbolic multilayered
  nanotubes

abstract:
  Highly-anisotropic plasmonic nanotubes exhibit a dramatic drop of the
scattering cross section in the transition regime from hyperbolic to elliptic
dispersion. The characterization of a realistic multilayered metamaterial is
typically carried out by means of an effective medium approach providing
average components of the permittivity tensor and wave fields. Here, the edge
effects of the metal-dielectric stratified nanotube for different combinations
were thoroughly analyzed. We show how the boundary layers, which in principle
remain fully irrelevant in the estimation of the effective permittivity of the
nanotube, however play a critical role in the resonant scattering spectra and
the near field patterns. A remarkable enhancement of the scattered wave field
is unexpectedly experienced at the frequencies of interest when a dielectric
layer is chosen to be in contact with the cavity core.


title: Exclusivity Regularized Machine

abstract:
  It has been recognized that the diversity of base learners is of utmost
importance to a good ensemble. This paper defines a novel measurement of
diversity, termed as exclusivity. With the designed exclusivity, we further
propose an ensemble model, namely Exclusivity Regularized Machine (ERM), to
jointly suppress the training error of ensemble and enhance the diversity
between bases. Moreover, an Augmented Lagrange Multiplier based algorithm is
customized to effectively and efficiently seek the optimal solution of ERM.
Theoretical analysis on convergence and global optimality of the proposed
algorithm, as well as experiments are provided to reveal the efficacy of our
method and show its superiority over state-of-the-art alternatives in terms of
accuracy and efficiency.


title:
Anomalous pinch of turbulent plasmas driven by the
  magnetic-drift-induced Lorentz force through the Stokes-Einstein relation

abstract:
  It is found that the Lorentz force generated by the magnetic drift drives a
generic plasma pinch fluxes of particle, energy and momentum through the
Stokes-Einstein relation. The proposed theoretical model applies for both
electrons and ions, trapped particles and passing particles.


title:
Influence of aqueous electrolytes on electrochemical performance of
  vertical graphene nanosheets supercapacitor electrode

abstract:
  Vertical graphene nanosheets (VGN) grown as controlled porous network are
studied and demonstrated as a promising electrode material for supercapacitors.
The VGN synthesized by microwave plasma enhanced chemical vapor deposition
using CH4/Ar gas mixture as precursor are considered for electrochemical
performance in Na2SO4, KOH, and H2SO4 to delineate the electrolyte effect.
Among the electrolytes, H2SO4 exhibited excellent specific areal capacitance
(188 microfarad/cm2) and good capacitance retention (96.8%). No significant
change is observed in impedance spectra even after 200 cycles. An electric
equivalent circuit for the system is simulated from Nyquist plot to elucidate
the behavior of electrode/electrolyte interface. This potential supercapacitor
electrode material is well characterized by scanning electron microscopy,
transmission electron microscopy, Raman spectroscopy, and contact angle
measurement. Utilization of aqueous electrolytes for potential supercapacitors
is also discussed in relation to improved performance observed in H2SO4 medium.


title:
Audio Visual Emotion Recognition with Temporal Alignment and Perception
  Attention

abstract:
  This paper focuses on two key problems for audio-visual emotion recognition
in the video. One is the audio and visual streams temporal alignment for
feature level fusion. The other one is locating and re-weighting the perception
attentions in the whole audio-visual stream for better recognition. The Long
Short Term Memory Recurrent Neural Network (LSTM-RNN) is employed as the main
classification architecture. Firstly, soft attention mechanism aligns the audio
and visual streams. Secondly, seven emotion embedding vectors, which are
corresponding to each classification emotion type, are added to locate the
perception attentions. The locating and re-weighting process is also based on
the soft attention mechanism. The experiment results on EmotiW2015 dataset and
the qualitative analysis show the efficiency of the proposed two techniques.


title:
A route towards controlling the morphology of vertical graphene
  nanosheets

abstract:
  Herein, an effort has given to sheds light on the effects of plasma process
parameters on the growth of vertical graphene nanosheets (VGNs) by plasma
enhanced chemical vapor deposition (PECVD. The parameters include substrate
temperature, microwave power and distance between plasma sources to substrate.
The significant influence of these variable parameters is observed on the
morphology, growth rate and crystallinity. Thus these parameters are found to
be deciding factors, which determine the surface reaction and growth kinetics
that governed the final structure and controlled morphology of VGNs. The
activation energy of the VGNs grown by PECVD is found to be 0.57 eV. A direct
evidence of vertical growth through the nanographitic island is observed from
temperature dependent growth of VGNs. Such understanding on growth of VGNs is
not only useful for growth mechanism under plasma chemistry but also beneficial
to get controlled and desired structure for field emission and energy storage
application.


title: Hierarchy of Groups Evaluation Using Different F-score Variants

abstract:
  The paper presents a cursory examination of clustering, focusing on a rarely
explored field of hierarchy of clusters. Based on this, a short discussion of
clustering quality measures is presented and the F-score measure is examined
more deeply. As there are no attempts to assess the quality for hierarchies of
clusters, three variants of the F-Score based index are presented: classic,
hierarchical and partial order. The partial order index is the authors'
approach to the subject. Conducted experiments show the properties of the
considered measures. In conclusions, the strong and weak sides of each variant
are presented.


title: Stationary radial centers and characterization of convex polyhedrons

abstract:
  We investigate centers of a body (the closure of a bounded open set) defined
as maximum points of potentials. In particular, we study centers defined by the
Riesz potential and by Poisson's integral. These centers, in general, depend on
parameters and move with respect to the parameters. We give a necessary and
sufficient condition for the existence of a center independent of a parameter.


title:
Mutations of the cluster algebra of type $\boldsymbol{A^{(1)}_1}$ and
  the periodic discrete Toda lattice

abstract:
  A direct connection between two sequences of points, one of which is
generated by seed mutations in the cluster algebra of type $A^{(1)}_1$ and the
other by time evolutions of the periodic discrete Toda lattice, is explicitly
given. In this construction, each of them is realized as an orbit of a QRT map
and specialization of the parameters in the maps and appropriate choices of the
initial points relate them. The connection with the periodic discrete Toda
lattice enables us a geometric interpretation of the seed mutations in the
cluster algebra of type $A^{(1)}_1$ as addition of points on an elliptic curve
arising as the spectral curve of the Toda lattice.


title:
A globally convergent algorithm for lasso-penalized mixture of linear
  regression models

abstract:
  Variable selection is an old and pervasive problem in regression analysis.
One solution is to impose a lasso penalty to shrink parameter estimates toward
zero and perform continuous model selection. The lasso-penalized mixture of
linear regressions model (L-MLR) is a class of regularization methods for the
model selection problem in the fixed number of variables setting. In this
article, we propose a new algorithm for the maximum penalized-likelihood
estimation of the L-MLR model. This algorithm is constructed via the
minorization--maximization algorithm paradigm. Such a construction allows for
coordinate-wise updates of the parameter components, and produces globally
convergent sequences of estimates that generate monotonic sequences of
penalized log-likelihood values. These three features are missing in the
previously presented approximate expectation-maximization algorithms. The
previous difficulty in producing a globally convergent algorithm for the
maximum penalized-likelihood estimation of the L-MLR model is due to the
intractability of finding exact updates for the mixture model mixing
proportions in the maximization-step. In our algorithm, we solve this issue by
showing that it can be converted into a polynomial root finding problem. Our
solution to this problem involves a polynomial basis conversion that is
interesting in its own right. The method is tested in simulation and with an
application to Major League Baseball salary data from the 1990s and the present
day. We explore the concept of whether player salaries are associated with
batting performance.


title:
Long-term optical variability of high-mass X-ray binaries. II.
  Spectroscopy

abstract:
  We present the results of our monitoring program to study the long-term
variability of the Halpha line in high-mass X-ray binaries. We have carried out
the most complete optical spectroscopic study of the global properties of
high-mass X-ray binaries so far with the analysis of more than 1100 spectra of
20 sources. Our aim is to characterise the optical variability timescales and
study the interaction between the neutron star and the accreting material. Our
results can be summarised as follows: i) we find that Be/X-ray binaries with
narrow orbits are more variable than systems with long orbital periods, ii) we
show that a Keplerian distribution of the gas particles provides a good
description of the disks in Be/X-ray binaries, as it does in classical Be
stars, iii) a decrease in the Halpha equivalent width is generally observed
after major X-ray outbursts, iv) we confirm that the Halpha equivalent width
correlates with disk radius, v) while systems with supergiant companions
display, multi-structured profiles, most of the Be/X-ray binaries show at some
epoch double-peak asymmetric profiles, indicating that density inhomogeneities
is a common property in the disk of Be/X-ray binaries, vi) the profile
variability (V/R ratio) timescales are shorter and the Halpha equivalent width
are smaller in Be/X-ray binaries than in isolated Be stars, and vii) we provide
new evidence that the disk in Be/X-ray binaries is on average denser than in
classical Be stars.


title: Continuous 3D Label Stereo Matching using Local Expansion Moves

abstract:
  We present an accurate stereo matching method using local expansion moves
based on graph cuts. This new move-making scheme is used to efficiently infer
per-pixel 3D plane labels on a pairwise Markov random field (MRF) that
effectively combines recently proposed slanted patch matching and curvature
regularization terms. The local expansion moves are presented as many
alpha-expansions defined for small grid regions. The local expansion moves
extend traditional expansion moves by two ways: localization and spatial
propagation. By localization, we use different candidate alpha-labels according
to the locations of local alpha-expansions. By spatial propagation, we design
our local alpha-expansions to propagate currently assigned labels for nearby
regions. With this localization and spatial propagation, our method can
efficiently infer MRF models with a continuous label space using randomized
search. Our method has several advantages over previous approaches that are
based on fusion moves or belief propagation; it produces submodular moves
deriving a subproblem optimality; it helps find good, smooth, piecewise linear
disparity maps; it is suitable for parallelization; it can use cost-volume
filtering techniques for accelerating the matching cost computations. Even
using a simple pairwise MRF, our method is shown to have best performance in
the Middlebury stereo benchmark V2 and V3.


title:
Spatially self-organized resilient networks by a distributed cooperative
  mechanism

abstract:
  The robustness of connectivity and the efficiency of paths are incompatible
in many real networks. We propose a self-organization mechanism for
incrementally generating onion-like networks with positive degree-degree
correlations whose robustness is nearly optimal. As a spatial extension of the
generation model based on cooperative copying and adding shortcut, we show that
the growing networks become more robust and efficient through enhancing the
onion-like topological structure on a space. The reasonable constraint for
locating nodes on the perimeter in typical surface growth as a self-propagation
does not affect these properties of the tolerance and the path length.
Moreover, the robustness can be recovered in the random growth damaged by
insistent sequential attacks even without any remedial measures.


title:
An inter comparison of the upper critical fields (Hc2) of different
  superconductors - YBa2Cu3O7, MgB2, NdFeAsO0.8F0.2, FeSe0.5Te0.5 and Nb2PdS5

abstract:
  Here we report the comparison of the upper critical fields of different
superconductors being calculated by two different theories i.e., Werthamer
Helfand Hohenburg (WHH) and Ginzberg Landau (GL). All the samples are
synthesized through previously known solid state reaction route. Phase purity
is determined from the Rietveld refinement of powder X-Ray diffraction (XRD)
data. High field (up to 14Tesla) magneto transport \r{ho}(T)H of different
superconductors is studied to estimate their upper critical field (Hc2). The
present inter comparison covers from Cuprates (YBa2Cu3O7) - Borides (MgB2) - Fe
pnictides (NdFeAsO0.8F0.2) and chalcogenides (FeSe0.5Te0.5) to robust Nb2PdS5.
The upper critical fields [Hc2(T)] at zero temperature are calculated by
extrapolating the data using GL and WHH equations.


title: Simultaneous stability of $C^\infty$ convex integrands and their duals

abstract:
  In this paper, the following three are shown. (1) For a $C^\infty$ convex
integrand $\gamma: S^n\to \mathbb{R}_+$, its dual convex integrand $\delta:
S^n\to \mathbb{R}_+$ is of class $C^\infty$. (2) For a stable convex integrand
$\gamma: S^n\to \mathbb{R}_+$, its dual convex integrand $\delta: S^n\to
\mathbb{R}_+$ is stable. (3) Let $\gamma: S^n\to \mathbb{R}_+$ be a stable
convex integrand. Then, for any $i$ $(0\le i\le n)$, $\theta_0\in S^n$ is a
non-degenerate critical point of $\gamma$ with Morse index $i$ if and only if
$-\theta_0\in S^n$ is a non-degenerate critical point of the dual convex
integrand ${\delta}$ with Morse index $(n-i)$.


title: Stuffle product formulas of multiple zeta values

abstract:
  We obtain recursive formulas for the stuffle product of multiple zeta values
and of multiple zeta-star values. Then we apply the formulas to prove several
stuffle product formulas with one or two strings of $z_p$'s. We also describe
how to use our formulas in general cases.


title:
Quark-Jet model for transverse momentum dependent fragmentation
  functions

abstract:
  In order to describe the hadronization of polarized quarks, we discuss an
extension of the quark-jet model to transverse momentum dependent fragmentation
functions. The description is based on a product ansatz, where each factor in
the product represents one of the transverse momentum dependent splitting
functions, which can be calculated by using effective quark theories. The
resulting integral equations and sum rules are discussed in detail for the case
of inclusive pion production. In particular, we demonstrate that the
3-dimensional momentum sum rules are satisfied naturally in this transverse
momentum dependent quark-jet model. Our results are well suited for numerical
calculations in effective quark theories, and can be implemented in Monte-Carlo
simulations of polarized quark hadronization processes.


title: Comparing Dualities and Gauge Symmetries

abstract:
  We discuss some aspects of the relation between dualities and gauge
symmetries. Both of these ideas are of course multi-faceted, and we confine
ourselves to making two points. Both points are about dualities in string
theory, and both have the 'flavour' that two dual theories are 'closer in
content' than you might think. For both points, we adopt a simple conception of
a duality as an 'isomorphism' between theories: more precisely, as appropriate
bijections between the two theories' sets of states and sets of quantities.
  The first point (Section 3) is that this conception of duality meshes with
two dual theories being 'gauge related' in the general philosophical sense of
being physically equivalent. For a string duality, such as T-duality and
gauge/gravity duality, this means taking such features as the radius of a
compact dimension, and the dimensionality of spacetime, to be 'gauge'.
  The second point (Sections 4, 5 and 6) is much more specific. We give a
result about gauge/gravity duality that shows its relation to gauge symmetries
(in the physical sense of symmetry transformations that are
spacetime-dependent) to be subtler than you might expect. For gauge theories,
you might expect that the duality bijections relate only gauge-invariant
quantities and states, in the sense that gauge symmetries in one theory will be
unrelated to any symmetries in the other theory. This may be so in general; and
indeed, it is suggested by discussions of Polchinski and Horowitz. But we show
that in gauge/gravity duality, each of a certain class of gauge symmetries in
the gravity/bulk theory, viz. diffeomorphisms, is related by the duality to a
position-dependent symmetry of the gauge/boundary theory.


title:
Effect of a Radiation Cooling and Heating Function on Standing
  Longitudinal Oscillations in Coronal Loops

abstract:
  Standing long-period (with the periods longer than several minutes)
oscillations in large hot (with the temperature higher than 3 MK) coronal loops
have been observed as the quasi-periodic modulation of the EUV and microwave
intensity emission and the Doppler shift of coronal emission lines, and have
been interpreted as standing slow magnetoacoustic (longitudinal) oscillations.
Quasi-periodic pulsations of shorter periods, detected in thermal and
non-thermal emissions in solar flares could be produced by a similar mechanism.
We present theoretical modelling of the standing slow magnetoacoustic mode,
showing that this mode of oscillation is highly sensitive to peculiarities of
the radiative cooling and heating function. We generalised the theoretical
model of standing slow magnetoacoustic oscillations in a hot plasma, including
the effects of the radiative losses, and accounting for plasma heating. The
heating mechanism is not specified and taken empirically to compensate the
cooling by radiation and thermal-conduction. It is shown that the evolution of
the oscillations is described by a generalised Burgers equation. Numerical
solution of an initial value problem for the evolutionary equation demonstrates
that different dependences of the radiative cooling and plasma heating on the
temperature lead to different regimes of the oscillations, including growing,
quasi-stationary and rapidly decaying. Our findings provide a theoretical
foundation for probing the coronal heating function, and may explain the
observations of decayless long-period quasi-periodic pulsations in flares. The
hydrodynamic approach employed in this study should be considered with caution
in the modelling of non-thermal emission associated with flares, as it misses
potentially important non-hydrodynamic effects.


title:
Distributed Fusion of Labeled Multi-Object Densities Via Label Spaces
  Matching

abstract:
  In this paper, we address the problem of the distributed multi-target
tracking with labeled set filters in the framework of Generalized Covariance
Intersection (GCI). Our analyses show that the label space mismatching (LS-DM)
phenomenon, which means the same realization drawn from label spaces of
different sensors does not have the same implication, is quite common in
practical scenarios and may bring serious problems. Our contributions are
two-fold. Firstly, we provide a principled mathematical definition of "label
spaces matching (LS-DM)" based on information divergence, which is also
referred to as LS-M criterion. Then, to handle the LS-DM, we propose a novel
two-step distributed fusion algorithm, named as GCI fusion via label spaces
matching (GCI-LSM). The first step is to match the label spaces from different
sensors. To this end, we build a ranked assignment problem and design a cost
function consistent with LS-M criterion to seek the optimal solution of
matching correspondence between label spaces of different sensors. The second
step is to perform the GCI fusion on the matched label space. We also derive
the GCI fusion with generic labeled multi-object (LMO) densities based on LS-M,
which is the foundation of labeled distributed fusion algorithms. Simulation
results for Gaussian mixture implementation highlight the performance of the
proposed GCI-LSM algorithm in two different tracking scenarios.


title:
Worldsheet theory of light-cone gauge noncritical strings on higher
  genus Riemann surfaces

abstract:
  It is possible to formulate light-cone gauge string field theory in
noncritical dimensions. Such a theory corresponds to conformal gauge worldsheet
theory with nonstandard longitudinal part. We study the longitudinal part of
the worldsheet theory on higher genus Riemann surfaces. The results in this
paper shall be used to study the dimensional regularization of light-cone gauge
string field theory.


title: Primordial Black Hole Scenario for the Gravitational-Wave Event GW150914

abstract:
  We point out that the gravitational-wave event GW150914 observed by the LIGO
detectors can be explained by the coalescence of primordial black holes (PBHs).
It is found that the expected PBH merger rate would exceed the rate estimated
by the LIGO scientific Collaboration and Virgo Collaboration if PBHs were the
dominant component of dark matter, while it can be made compatible if PBHs
constitute a fraction of dark matter. Intriguingly, the abundance of PBHs
required to explain the suggested lower bound on the event rate, $> 2$ events
${\rm Gpc}^{-3} {\rm yr}^{-1}$, roughly coincides with the existing upper limit
set by the nondetection of the cosmic microwave background spectral distortion.
This implies that the proposed PBH scenario may be tested in the
not-too-distant future.


title: Nonparaxial accelerating Talbot effect

abstract:
  We demonstrate the fractional Talbot effect of nonpraxial accelerating beams,
theoretically and numerically. It is based on the interference of nonparaxial
accelerating solutions of the Helmholtz equation in two dimensions. The effect
originates from the interfering lobes of a superposition of the solutions that
accelerate along concentric semicircular trajectories with different radii.
Talbot images form along certain central angles, which are referred to as the
Talbot angles. The fractional nonparaxial Talbot effect is obtained by choosing
the coefficients of beam components properly. A single nonparaxial accelerating
beam possesses duality --- it can be viewed as a Talbot effect of itself with
an infinite or zero Talbot angle. These results improve the understanding of
nonparaxial accelerating beams and the Talbot effect among them.


title:
Distributed Fusion with Multi-Bernoulli Filter based on Generalized
  Covariance Intersection

abstract:
  In this paper, we propose a distributed multi-object tracking algorithm
through the use of multi-Bernoulli (MB) filter based on generalized Covariance
Intersection (G-CI). Our analyses show that the G-CI fusion with two MB
posterior distributions does not admit an accurate closed-form expression. To
solve this challenging problem, we firstly approximate the fused posterior as
the unlabeled version of $\delta$-generalized labeled multi-Bernoulli
($\delta$-GLMB) distribution, referred to as generalized multi-Bernoulli (GMB)
distribution. Then, to allow the subsequent fusion with another multi-Bernoulli
posterior distribution, e.g., fusion with a third sensor node in the sensor
network, or fusion in the feedback working mode, we further approximate the
fused GMB posterior distribution as an MB distribution which matches its
first-order statistical moment. The proposed fusion algorithm is implemented
using sequential Monte Carlo technique and its performance is highlighted by
numerical results.


title: Constructive Canonicity of Inductive Inequalities

abstract:
  We prove the canonicity of inductive inequalities in a constructive
meta-theory, for classes of logics algebraically captured by varieties of
normal and regular lattice expansions. This result encompasses
Ghilardi-Meloni's and Suzuki's constructive canonicity results for Sahlqvist
formulas and inequalities, and is based on an application of the tools of
unified correspondence theory. Specifically, we provide an alternative
interpretation of the language of the algorithm ALBA for lattice expansions:
nominal and conominal variables are respectively interpreted as closed and open
elements of canonical extensions of normal/regular lattice expansions, rather
than as completely join-irreducible and meet-irreducible elements of perfect
normal/regular lattice expansions. We show the correctness of ALBA with respect
to this interpretation. From this fact, the constructive canonicity of the
inequalities on which ALBA succeeds follows by an adaptation of the standard
argument. The claimed result then follows as a consequence of the success of
ALBA on inductive inequalities.


title:
Hierarchical Gaussian Mixture Model with Objects Attached to Terminal
  and Non-terminal Dendrogram Nodes

abstract:
  A hierarchical clustering algorithm based on Gaussian mixture model is
presented. The key difference to regular hierarchical mixture models is the
ability to store objects in both terminal and nonterminal nodes. Upper levels
of the hierarchy contain sparsely distributed objects, while lower levels
contain densely represented ones. As it was shown by experiments, this ability
helps in noise detection (modelling). Furthermore, compared to regular
hierarchical mixture model, the presented method generates more compact
dendrograms with higher quality measured by adopted F-measure.


title: Turbulent transport of alpha particles in tokamak plasmas

abstract:
  We investigate the ExB diffusion of fusion born \alpha particles in tokamak
plasmas. We determine the transport regimes for a realistic model that has the
characteristics of the ion temperature gradient (ITG) or of the trapped
electron modes (TEM) driven turbulence. It includes a spectrum of potential
fluctuations that is modeled using the results of the numerical simulations,
the drift of the potential with the effective diamagnetic velocity and the
parallel motion. Our semi-analytical statistical approach is based on the
decorrelation trajectory method (DTM), which is adapted to the gyrokinetic
approximation. We obtain the transport coefficients as a function of the
parameters of the turbulence and of the energy of the \alpha particle.
According to our results, signficant turbulent transport of the \alpha
particles can appear only at energies of the order of 100KeV. We determine the
corresponding conditions.


title: The unresolved mystery of the great divergence is solved

abstract:
  The so-called great divergence in the income per capita is described in the
Unified Growth Theory as the mind-boggling and unresolved mystery about the
growth process. This mystery has now been solved: the great divergence never
happened. It was created by the manipulation of data. Economic growth in
various regions is at different levels of development but it follows similar,
non-divergent trajectories. Unified Growth Theory is shown yet again to be
incorrect and scientifically unacceptable. It promotes incorrect and even
potentially dangerous concepts. The distorted presentation of data supporting
the concept of the great divergence shows that economic growth is now
developing along moderately-increasing trajectories but mathematical analysis
of the same data and even their undistorted presentation shows that these
trajectories are now increasing approximately vertically with time. So, while
the distorted presentation of data used in the Unified Growth Theory suggests
generally sustainable and secure economic growth, the undistorted presentation
of data demonstrates that the growth is unsustainable and insecure. The concept
of takeoffs from stagnation to the sustained-growth regime promoted in the
Unified Growth Theory is also dangerously misleading because it suggests a
sustainable and prosperous future while the mathematical analysis of data shows
that the current economic growth is insecure and unsustainable.


title: $\mathcal{PT}$ symmetry in a fractional Schr\"odinger equation

abstract:
  We investigate the fractional Schr\"odinger equation with a periodic
$\mathcal{PT}$-symmetric potential. In the inverse space, the problem transfers
into a first-order nonlocal frequency-delay partial differential equation. We
show that at a critical point, the band structure becomes linear and symmetric
in the one-dimensional case, which results in a nondiffracting propagation and
conical diffraction of input beams. If only one channel in the periodic
potential is excited, adjacent channels become uniformly excited along the
propagation direction, which can be used to generate laser beams of high power
and narrow width. In the two-dimensional case, there appears conical
diffraction that depends on the competition between the fractional Laplacian
operator and the $\mathcal{PT}$-symmetric potential. This investigation may
find applications in novel on-chip optical devices.