title:
Resolvent and propagation estimates for Klein-Gordon equations with
  non-positive energy

abstract:
  We study in this paper an abstract class of Klein-Gordon equations: \[
\p_{t}^{2}\phi(t)- 2\i k \p_{t}\phi(t)+ h \phi(t)=0, \] where $\phi: \rr\to
\cH$, $\cH$ is a (complex) Hilbert space, and $h$, $k$ are self-adjoint, resp.
symmetric operators on $\cH$. We consider their generators $H$ (resp. $K$) in
the two natural spaces of Cauchy data, the energy (resp. charge) spaces. We do
not assume that the dynamics generated by $H$ or $K$ has any positive conserved
quantity, in particular these operators may have complex spectrum. Assuming
conditions on $h$ and $k$ which allow to use the theory of selfadjoint
operators on Krein spaces, we prove weighted estimates on the boundary values
of the resolvents of $H$, $K$ on the real axis. From these resolvent estimates
we obtain corresponding propagation estimates on the behavior of the dynamics
for large times. Examples include wave or Klein-Gordon equations on
asymptotically euclidean or asymptotically hyperbolic manifolds, minimally
coupled with an external electro-magnetic field decaying at infinity.


title:
Bayesian Identification of Elastic Constants in Multi-Directional
  Laminate from Moir\'e Interferometry Displacement Fields

abstract:
  The ply elastic constants needed for classical lamination theory analysis of
multi-directional laminates may differ from those obtained from unidirectional
laminates because of three dimensional effects. In addition, the unidirectional
laminates may not be available for testing. In such cases, full-field
displacement measurements offer the potential of identifying several material
properties simultaneously. For that, it is desirable to create complex
displacement fields that are strongly influenced by all the elastic constants.
In this work, we explore the potential of using a laminated plate with an
open-hole under traction loading to achieve that and identify all four ply
elastic constants (E 1, E 2, 12, G 12) at once. However, the accuracy of the
identified properties may not be as good as properties measured from individual
tests due to the complexity of the experiment, the relative insensitivity of
the measured quantities to some of the properties and the various possible
sources of uncertainty. It is thus important to quantify the uncertainty (or
confidence) with which these properties are identified. Here, Bayesian
identification is used for this purpose, because it can readily model all the
uncertainties in the analysis and measurements, and because it provides the
full coupled probability distribution of the identified material properties. In
addition, it offers the potential to combine properties identified based on
substantially different experiments. The full-field measurement is obtained by
moir\'e interferometry. For computational efficiency the Bayesian approach was
applied to a proper orthogonal decomposition (POD) of the displacement fields.
The analysis showed that the four orthotropic elastic constants are determined
with quite different confidence levels as well as with significant correlation.
Comparison with manufacturing specifications showed substantial difference in
one constant, and this conclusion agreed with earlier measurement of that
constant by a traditional four-point bending test. It is possible that the POD
approach did not take full advantage of the copious data provided by the full
field measurements, and for that reason that data is provided for others to use
(as on line material attached to the article).


title: Densities, submeasures and partitions of groups

abstract:
  In 1995 in Kourovka notebook the second author asked the following problem:
it is true that for each partition $G=A_1\cup\dots\cup A_n$ of a group $G$
there is a cell $A_i$ of the partition such that $G=FA_iA_i^{-1}$ for some set
$F\subset G$ of cardinality $|F|\le n$? In this paper we survey several partial
solutions of this problem, in particular those involving certain canonical
invariant densities and submeasures on groups.


title: Complexity and simplicity of plasmas

abstract:
  This paper has two main parts. The first one presents a direct path from
microscopic dynamics to Debye screening, Landau damping and collisional
transport. It shows there is more simplicity in microscopic plasma physics than
previously thought. The second part is more subjective. It describes some
difficulties in facing plasma complexity in general, suggests an inquiry about
the methods used empirically to tackle complex systems, discusses the teaching
of plasma physics as a physics of complexity, and proposes new directions to
face the inflation of information.


title: Handwritten and Printed Text Separation in Real Document

abstract:
  The aim of the paper is to separate handwritten and printed text from a real
document embedded with noise, graphics including annotations. Relying on
run-length smoothing algorithm (RLSA), the extracted pseudo-lines and
pseudo-words are used as basic blocks for classification. To handle this, a
multi-class support vector machine (SVM) with Gaussian kernel performs a first
labelling of each pseudo-word including the study of local neighbourhood. It
then propagates the context between neighbours so that we can correct possible
labelling errors. Considering running time complexity issue, we propose linear
complexity methods where we use k-NN with constraint. When using a kd-tree, it
is almost linearly proportional to the number of pseudo-words. The performance
of our system is close to 90%, even when very small learning dataset where
samples are basically composed of complex administrative documents.


title:
Estimation of consistent parameter sets for continuous-time nonlinear
  systems using occupation measures and LMI relaxations

abstract:
  Obtaining initial conditions and parameterizations leading to a model
consistent with available measurements or safety specifications is important
for many applications. Examples include model (in-)validation, prediction,
fault diagnosis, and controller design. We present an approach to determine
inner- and outer-approximations of the set containing all consistent initial
conditions/parameterizations for nonlinear continuous-time systems. These
approximations are found by occupation measures that encode the system dynamics
and measurements, and give rise to an infinite-dimensional linear program. We
exploit the flexibility and linearity of the decision problem to incorporate
uncertain-but-bounded and pointwise-in-time state and output constraints, a
feature which was not addressed in previous works. The infinite-dimensional
linear program is relaxed by a hierarchy of LMI problems that provide
certificates in case no consistent initial condition/parameterization exists.
Furthermore, the applied LMI relaxation guarantees that the approximations
converge (almost uniformly) to the true consistent set. We illustrate the
approach with a biochemical reaction network involving unknown initial
conditions and parameters.


title: Magnetoelastic effects in doped Fe2P

abstract:
  We use combine high resolution neutron diffraction (HRPD) with density
functional theory (DFT) to investigate the exchange striction at the Curie
temperature (TC) of Fe2P and to examine the effect of boron and carbon doping
on the P site. We find a significant contraction of the basal plane on heating
through TC with a simultaneous increase of the c-axis that results in a small
overall volume change of ~0.01%. At the magnetic transition the FeI-FeI
distance drops significantly and becomes shorter than FeI-FeII . The shortest
metal-metalloid (FeI-PI) distance also decreases sharply. Our DFT model reveals
the importance of the latter as this structural change causes a redistribution
of the FeI moment along the c-axis (Fe-P chain). We are able to understand the
site preference of the dopants, the effect of which can be linked to the
increased moment on the FeI-site, brought about by strong magneto-elasticity
and changes in the electronic band structure.


title: On Procesi bundles

abstract:
  Procesi bundles are certain vector bundles on symplectic resolutions of
symplectic quotient singularities for wreath-products of the symmetric groups
with Kleinian groups. Roughly speaking, we can define Procesi bundles as
bundles on resolutions that provide derived McKay equivalence. In this paper we
classify Procesi bundles on resolutions obtained by Hamiltonian reduction and
relate the Procesi bundles to the tautological bundles on the resolutions. Our
proofs are based on deformation arguments and a connection of Procesi bundles
with Symplectic reflection algebras.


title: Nonequilibrium dynamical mean field simulation of inhomogeneous systems

abstract:
  We extend the nonequilibrium dynamical mean field (DMFT) formalism to
inhomogeneous systems by adapting the "real-space" DMFT method to Keldysh
Green's functions. Solving the coupled impurity problems using strong-coupling
perturbation theory, we apply the formalism to homogeneous and inhomogeneous
layered systems with strong local interactions and up to 39 layers. We study
the diffusion of doublons and holes created by photo-excitation in a Mott
insulating system, the time-dependent build-up of the polarization and the
current induced by a linear voltage bias across a multi-layer structure, and
the photo-induced current in a Mott insulator under bias.


title:
Mechanical properties of nanosheets and nanotubes investigated using a
  new geometry independent volume definition

abstract:
  Cross-sectional area and volume become difficult to define as material
dimensions approach the atomic scale. This limits the transferability of
macroscopic concepts such as Young's modulus. We propose a new volume
definition where the enclosed nanosheet or nanotube average electron density
matches that of the parent layered bulk material. We calculate the Young's
moduli for various nanosheets (including graphene, BN and MoS2) and nanotubes.
Further implications of this new volume definition such as a Fermi level
dependent Young's modulus and out-of-plane Poisson's ratio are shown.


title: On a class of space-time intrinsic random functions

abstract:
  Power law generalized covariance functions provide a simple model for
describing the local behavior of an isotropic random field. This work seeks to
extend this class of covariance functions to spatial-temporal processes for
which the degree of smoothness in space and in time may differ while
maintaining other desirable properties for the covariance functions, including
the availability of explicit convergent and asymptotic series expansions.


title:
Astrophysical and experimental implications from the magnetorotational
  instability of toroidal fields

abstract:
  The interaction of differential rotation and toroidal fields that are
current-free in the gap between two corotating axially unbounded cylinders is
considered. It is shown that nonaxisymmetric perturbations are unstable if the
rotation rate and Alfv\'en frequency of the field are of the same order, almost
independent of the magnetic Prandtl number Pm. For the very steep rotation law
\Omega\propto R^{-2} (the Rayleigh limit) and for small Pm the threshold values
of rotation and field for this Azimuthal MagnetoRotational Instability (AMRI)
scale with the ordinary Reynolds number and the Hartmann number, resp. A
laboratory experiment with liquid metals like sodium or gallium in a
Taylor-Couette container has been designed on the basis of this finding. For
fluids with more flat rotation laws the Reynolds number and the Hartmann number
are no longer typical quantities for the instability. For the weakly nonlinear
system the numerical values of the kinetic energy and the magnetic energy are
derived for magnetic Prandtl numbers \leq 1. We find that the magnetic energy
grows monotonically with the magnetic Reynolds number Rm, while the kinetic
energy grows with Rm/\sqrt{Pm}. The resulting turbulent Schmidt number, as the
ratio of the `eddy' viscosity and the diffusion coefficient of a passive scalar
(such as lithium) is of order 20 for Pm=1, but for small Pm it drops to order
unity. Hence, in a stellar core with fossil fields and steep rotation law the
transport of angular momentum by AMRI is always accompanied by an intense
mixing of the plasma, until the rotation becomes rigid.


title:
Constructing numerically stable Kalman filter-based algorithms for
  gradient-based adaptive filtering

abstract:
  This paper addresses the numerical aspects of adaptive filtering (AF)
techniques for simultaneous state and parameters estimation arising in the
design of dynamic positioning systems in many areas of research. The AF schemes
consist of a recursive optimization procedure to identify the uncertain system
parameters by minimizing an appropriate defined performance index and the
application of the Kalman filter (KF) for dynamic positioning purpose. The use
of gradient-based optimization methods in the AF computational schemes yields
to a set of the filter sensitivity equations and a set of matrix Riccati-type
sensitivity equations. The filter sensitivities evaluation is usually done by
the conventional KF, which is known to be numerically unstable, and its
derivatives with respect to unknown system parameters. Recently, a novel
square-root approach for the gradient-based AF by the method of the maximum
likelihood has been proposed. In this paper, we show that various square-root
AF schemes can be derived from only two main theoretical results. This elegant
and simple computational technique replaces the standard methodology based on
direct differentiation of the conventional KF equations (with their inherent
numerical instability) by advanced square-root filters (and its derivatives as
well). As a result, it improves the robustness of the computations against
roundoff errors and leads to accurate variants of the gradient-based AFs.
Additionally, such methods are ideal for simultaneous state estimation and
parameter identification since all values are computed in parallel. The
numerical experiments are given.


title:
HeI in the central Giant HII Region of NGC 5253. A 2D observational
  approach to collisional and radiative transfer effects

abstract:
  ABRIDGED: NGC5253 is an ideal laboratory for detailed studies of starburst
galaxies. We present for the first time in a starburst galaxy a 2D study of the
spatial behavior of collisional and radiative transfer effects in He^+. The HeI
lines are analysed based on data obtained with FLAMES and GMOS. Collisional
effects are negligible for transitions in the singlet cascade while relatively
important for those in the triplet cascade. In particular, they can contribute
up to 20% of the flux in the HeIl7065 line. Radiative transfer effects are
important over an extended and circular area of 30pc in diameter centered at
the Super Star Clusters. HeI abundance, y^+, has been mapped using extinction
corrected fluxes of six HeI lines, realistic assumptions for T_e, n_e, and the
stellar absorption equivalent width as well as the most recent emissivities. We
found a mean of 10^3 y^+ ~80.3 over the mapped area. The relation between the
excitation and the total helium abundance, y_tot, is consistent with no
abundance gradient. Uncertainties in the derivation of He abundances are
dominated by the adopted assumptions. We illustrated the difficulty of
detecting a putative He enrichment due to the presence of Wolf-Rayet stars in
the main GHIIR. Data are marginally consistent with an excess in the N/He ratio
in the N enriched area of the order of both, the atmospheric N/He ratios in WR
stars and the uncertainties estimated for the N/He ratios.


title:
Multidimensional On-lattice Higher-order Models in the Thermal Lattice
  Boltzmann Theory

abstract:
  We present a set of uniform polynomial equations that provides
multidimensional on-lattice higher-order models of the lattice Boltzmann
theory, while keeping compact the number of discrete velocities. As examples,
we explicitly derive two- and three-dimensional on-lattice models applicable to
describing thermal compressible flows of the accuracy levels of the
Navier-Stokes equations with smaller numbers of discrete velocities in
comparison to the existing models. We demonstrate the accuracy and stability of
the three-dimensional model by using the Riemann problem.


title:
On stochastic integration for volatility modulated Brownian-driven
  Volterra processes via white noise analysis

abstract:
  This paper generalizes the integration theory for volatility modulated
Brownian-driven Volterra processes onto the space G* of Potthoff-Timpel
distributions. Sufficient conditions for integrability of generalized processes
are given, regularity results and properties of the integral are discussed. We
introduce a new volatility modulation method through the Wick product and
discuss its relation to the pointwise-multiplied volatility model.


title: Optimal constraint on g_NL from CMB

abstract:
  An optimal method to constrain the non-linearity parameter g_NL of the
local-type non-Gaussianity from CMB data is proposed. Our optimal estimator for
g_NL is separable and can be efficiently computed in real space. Combining the
exact filtering of CMB maps with the full covariance matrix, our method allows
us to extract cosmological information from observed data as much as possible
and obtain a tighter constraint on g_NL than previous studies. Applying our
method to the WMAP 9-year data, we obtain the constraint g_NL = (-3.3 +- 2.2)
10^5, which is a few times tighter than previous ones. We also make a forecast
for PLANCK data by using the Fisher matrix analysis.


title: Influence of Particle Size Distribution on Random Close Packing

abstract:
  The densest amorphous packing of rigid particles is known as random close
packing. It has long been appreciated that higher densities are achieved by
using collections of particles with a variety of sizes. The variety of sizes is
often quantified by the polydispersity of the particle size distribution: the
standard deviation of the radius divided by the mean radius. Several prior
studies quantified the increase of the packing density as a function of
polydispersity. Of course, a particle size distribution is also characterized
by its skewness, kurtosis, and higher moments, but the influence of these
parameters has not been carefully quantified before. In this work, we
numerically generate many packings with different particle radii distributions,
varying polydispersity and skewness independently of one another. We find two
significant results. First, the skewness can have a significant effect on the
packing density and in some cases can have a larger effect than polydispersity.
Second, the packing fraction is relatively insensitive to the value of the
kurtosis. We present a simple empirical formula for the value of the random
close packing density as a function of polydispersity and skewness.


title:
Efficient numerical algorithms for three-dimensional fractional partial
  differential equations

abstract:
  This paper detailedly discusses the locally one-dimensional numerical methods
for efficiently solving the three-dimensional fractional partial differential
equations, including fractional advection diffusion equation and Riesz
fractional diffusion equation. The second order finite difference scheme is
used to discretize the space fractional derivative and the Crank-Nicolson
procedure to the time derivative. We theoretically prove and numerically verify
that the presented numerical methods are unconditionally stable and second
order convergent in both space and time directions. In particular, for the
Riesz fractional diffusion equation, the idea of reducing the splitting error
is used to further improve the algorithm, and the unconditional stability and
convergency are also strictly proved and numerically verified for the improved
scheme.


title:
The role of hidden influentials in the diffusion of online information
  cascades

abstract:
  In a diversified context with multiple social networking sites, heterogeneous
activity patterns and different user-user relations, the concept of
"information cascade" is all but univocal. Despite the fact that such
information cascades can be defined in different ways, it is important to check
whether some of the observed patterns are common to diverse contagion processes
that take place on modern social media. Here, we explore one type of
information cascades, namely, those that are time-constrained, related to two
kinds of socially-rooted topics on Twitter. Specifically, we show that in both
cases cascades sizes distribute following a fat tailed distribution and that
whether or not a cascade reaches system-wide proportions is mainly given by the
presence of so-called hidden influentials. These latter nodes are not the hubs,
which on the contrary, often act as firewalls for information spreading. Our
results are important for a better understanding of the dynamics of complex
contagion and, from a practical side, for the identification of efficient
spreaders in viral phenomena.


title: On the fundamental domain of affine Springer fibers

abstract:
  For $G$ a connected reductive group, $\gamma\in \kg(F)$ semisimple regular
integral, we introduce a fundamental domain $F_{\gamma}$ for the affine
Springer fibers $\xx_{\gamma}$. There is a beautiful way to reduce the purity
conjecture of $\xx_{\gamma}$ to that of $F_{\gamma}$, we call it the
Arthur-Kottwitz reduction. When restricted to the unramified case, it turns out
that these fundamental domains behave well in family. We formulate a
rationality conjecture about a generating series of their Poincar\'e
polynomials. We then study them in detail for the group $\gl_{3}$. In
particular, we pave them in affine spaces and we prove the rationality
conjecture.


title:
Formation and stability of a two-dimensional nickel silicide on Ni (111)
  an Auger, LEED, STM, and high-resolution photoemission Study

abstract:
  Using low energy electron diffraction (LEED), Auger electron spectroscopy
(AES), scanning tunnelling microscopy (STM) and high resolution photo-electron
spectroscopy (HR-PES) techniques we have studied the annealing effect of one
silicon monolayer deposited at room temperature onto a Ni (111) substrate. The
variations of the Si surface concentration, recorded by AES at 300{\deg}C and
400{\deg}C, show at the beginning a rapid Si decreasing followed by a slowing
down up to a plateau equivalent to about 1/3 silicon monolayer. STM images and
LEED patterns, both recorded at room temperature just after annealing, reveal
the formation of an ordered hexagonal superstructure(rot3xrot3)R30{\deg}-type.
From these observations and from a quantitative analysis of HR-PES data,
recorded before and after annealing, we propose that the (rot3 x
rot3)R30{\deg}superstructure corresponds to a two dimensional (2D) Ni2Si
surface silicide.


title: Geospatial Optimization Problems

abstract:
  There are numerous applications which require the ability to take certain
actions (e.g. distribute money, medicines, people etc.) over a geographic
region. A disaster relief organization must allocate people and supplies to
parts of a region after a disaster. A public health organization must allocate
limited vaccine to people across a region. In both cases, the organization is
trying to optimize something (e.g. minimize expected number of people with a
disease). We introduce "geospatial optimization problems" (GOPs) where an
organization has limited resources and budget to take actions in a geographic
area. The actions result in one or more properties changing for one or more
locations. There are also certain constraints on the combinations of actions
that can be taken. We study two types of GOPs - goal-based and
benefit-maximizing (GBGOP and BMGOP respectively). A GBGOP ensures that certain
properties must be true at specified locations after the actions are taken
while a BMGOP optimizes a linear benefit function. We show both problems to be
NP-hard (with membership in NP for the associated decision problems).
Additionally, we prove limits on approximation for both problems. We present
integer programs for both GOPs that provide exact solutions. We also correctly
reduce the number of variables in for the GBGOP integer constraints. For BMGOP,
we present the BMGOP-Compute algorithm that runs in PTIME and provides a
reasonable approximation guarantee in most cases.


title:
Formulation of the Schwinger mechanism in classical statistical field
  theory

abstract:
  In this paper, we show how classical statistical field theory techniques can
be used to efficiently perform the numerical evaluation of the non-perturbative
Schwinger mechanism of particle production by quantum tunneling. In some
approximation, we also consider the back-reaction of the produced particles on
the external field, as well as the self-interactions of the produced particles.


title: Experimental distribution of entanglement with separable carriers

abstract:
  The key requirement for quantum networking is the distribution of
entanglement between nodes. Surprisingly, entanglement can be generated across
a network without direct transfer - or communication - of entanglement. In
contrast to information gain, which cannot exceed the communicated information,
the entanglement gain is bounded by the communicated quantum discord, a more
general measure of quantum correlation that includes but is not limited to
entanglement. Here, we experimentally entangle two communicating parties
sharing three initially separable photonic qubits by exchange of a carrier
photon that is unentangled with either party at all times. We show that
distributing entanglement with separable carriers is resilient to noise and in
some cases becomes the only way of distributing entanglement through noisy
environments.


title: Quasi-local black hole horizons

abstract:
  This article introduces the subject of quasi-local horizons at a level
suitable for physics graduate students who have taken a first course on general
relativity. It reviews properties of trapped surfaces and trapped regions in
some simple examples, general properties of trapped surfaces including their
stability properties, the definitions and some applications of dynamical-,
trapping-, and isolated-horizons.


title: Spin foams

abstract:
  The spin foam framework provides a way to define the dynamics of canonical
loop quantum gravity in a spacetime covariant way, by using a path integral
over histories of quantum states which can be interpreted as `quantum
space-times'. This chapter provides a basic introduction to spin foams aimed
principally at beginning graduate students and, where possible, at broader
audiences.


title:
Light-ion production from O, Si, Fe and Bi induced by 175 MeV
  quasi-monoenergetic neutron

abstract:
  We have measured double-differential cross sections in the interaction of 175
MeV quasimonoenergetic neutrons with O, Si, Fe and Bi. We have compared these
results with model calculations with INCL4.5-Abla07, MCNP6 and TALYS-1.2. We
have also compared our data with PHITS calculations, where the pre-equilibrium
stage of the reaction was accounted respectively using the JENDL/HE-2007
evaluated data library, the quantum molecular dynamics model (QMD) and a
modified version of QMD (MQMD) to include a surface coalescence model. The most
crucial aspect is the formation and emission of composite particles in the
pre-equilibrium stage.


title:
On Improving Energy Efficiency within Green Femtocell Networks: A
  Hierarchical Reinforcement Learning Approach

abstract:
  One of the efficient solutions of improving coverage and increasing capacity
in cellular networks is the deployment of femtocells. As the cellular networks
are becoming more complex, energy consumption of whole network infrastructure
is becoming important in terms of both operational costs and environmental
impacts. This paper investigates energy efficiency of two-tier femtocell
networks through combining game theory and stochastic learning. With the
Stackelberg game formulation, a hierarchical reinforcement learning framework
is applied for studying the joint expected utility maximization of macrocells
and femtocells subject to the minimum signal-to-interference-plus-noise-ratio
requirements. In the learning procedure, the macrocells act as leaders and the
femtocells are followers. At each time step, the leaders commit to dynamic
strategies based on the best responses of the followers, while the followers
compete against each other with no further information but the leaders'
transmission parameters. In this paper, we propose two reinforcement learning
based intelligent algorithms to schedule each cell's stochastic power levels.
Numerical experiments are presented to validate the investigations. The results
show that the two learning algorithms substantially improve the energy
efficiency of the femtocell networks.


title: Thermalization in collisions of large nuclei at high energies

abstract:
  Hydrodynamical analysis of experimental data of ultrarelativistic heavy ion
collisions seems to indicate that the hot QCD matter created in the collisions
thermalizes very quickly. Theoretically, we have no idea why this should be
true. In this proceeding, I will describe how the thermalization takes place in
the most theoretically clean limit -- that of large nuclei at asymptotically
high energy per nucleon, where the system is described by weak-coupling QCD. In
this limit, plasma instabilities dominate the dynamics from immediately after
the collision until well after the plasma becomes nearly in equilibrium at time
t \alpha^(-5/2)Q^(-1).


title: Critical dimension in profile semiparametric estimation

abstract:
  This paper revisits the classical inference results for profile quasi maximum
likelihood estimators (profile MLE) in the semiparametric estimation problem.
We mainly focus on two prominent theorems: the Wilks phenomenon and Fisher
expansion for the profile MLE are stated in a new fashion allowing finite
samples and model misspecification. The method of study is also essentially
different from the usual analysis of the semiparametric problem based on the
notion of the hardest parametric submodel. Instead we derive finite sample
deviation bounds for the linear approximation error for the gradient of the
loglikelihood. This novel approach particularly allows to address the important
issue of the effective target and nuisance dimension. The obtained
nonasymptotic results are surprisingly sharp and yield the classical asymptotic
statements including the asymptotic normality and efficiency of the profile
MLE. The general results are specified to the important special cases of an
i.i.d. sample and the analysis is exemplified with a single index model.


title:
Electro-thermal characterization of Si-Ge HBTs with pulse measurement
  and transient simulation

abstract:
  This paper describes a new and simple approach to accurately characterize the
transient self-heating effect in Si-Ge Heterojunction Bipolar Transistors
(HBTs), based on pulse measurements and verified through transient
electro-thermal simulations. The measurements have been carried out over pulses
applied at Base and Collector terminals simultaneously and the time response of
Collector current increase due to self-heating effect are obtained. Compared to
previous approach, a complete calibration has been performed including all the
passive elements such as coaxial cables, connectors and bias network.
Furthermore, time domain junction temperature variations, current of heat flux
and lattice temperature distribution have been obtained numerically by means of
3D electro-thermal device simulations. The thermal parameters extracted from
measurements using HiCuM HBT compact model have been verified with the
parameters extracted from electro-thermal transient simulation. It has been
shown that, the standard R-C thermal network is not sufficient to accurately
model the thermal spreading behavior and therefore a recursive network has been
employed which is more physical and suitable for transient electro-thermal
modeling.


title: Extending the range of the inductionless magnetorotational instability

abstract:
  The magnetorotational instability (MRI) can destabilize hydrodynamically
stable rotational flows, thereby allowing angular momentum transport in
accretion disks. A notorious problem for MRI is its questionable applicability
in regions with low magnetic Prandtl number, as they are typical for
protoplanetary disks and the outer parts of accretion disks around black holes.
Using the WKB method, we extend the range of applicability of MRI by showing
that the inductionless versions of MRI, such as the helical MRI and the
azimuthal MRI, can easily destabilize Keplerian profiles ~ 1/r^(3/2) if the
radial profile of the azimuthal magnetic field is only slightly modified from
the current-free profile ~ 1/r. This way we further show how the formerly known
lower Liu limit of the critical Rossby number, Ro=-0.828, connects naturally
with the upper Liu limit, Ro=+4.828.

categories: astro-ph.SR math-ph math.MP physics.flu-dyn physics.plasm-ph


title: How to Measure the Quantum Geometry of Bloch Bands

abstract:
  Single-particle states in electronic Bloch bands form a Riemannian manifold
whose geometric properties are described by two gauge invariant tensors, one
being symmetric the other being antisymmetric, that can be combined into the
so-called Fubini-Study metric tensor of the projective Hilbert space. The
latter directly controls the Hall conductivity. Here we show that the symmetric
part of the Fubini-Study metric tensor also has measurable consequences by
demonstrating that it enters the current noise spectrum. In particular, we show
that a non-vanishing equilibrium current noise spectrum at zero temperature is
unavoidable whenever Wannier states have non-zero minimum spread, the latter
being quantifiable by the symmetric part of the Fubini-Study metric tensor. We
illustrate our results by three examples: (1) atomic layers of hexagonal boron
nitride, (2) graphene, and (3) the surface states of three-dimensional
topological insulators when gaped by magnetic dopants.


title:
Unveiling the complex glassy dynamics of square shoulder systems:
  simulations and theory

abstract:
  We performed extensive molecular dynamics (MD) simulations, supplemented by
Mode Coupling Theory (MCT) calculations, for the Square Shoulder (SS) model, a
purely repulsive potential where the hard-core is complemented by a finite
shoulder. For the one-component version of this model, MCT predicted [Sperl
{\it et al.} Phys. Rev. Lett. {\bf 104}, 145701 (2010)] the presence of
diffusion anomalies both upon cooling and upon compression and the occurrence
of glass-glass transitions. In the simulations, we focus on a non-crystallising
binary mixture, which, at the investigated shoulder width, shows a
non-monotonic behaviour of the diffusion upon cooling but not upon isothermal
compression. In addition, we find the presence of a disconnected glass-glass
line in the phase diagram, ending in two higher-order singularities. These
points generate a logarithmic dependence of the density correlators as well as
a subdiffusive behaviour of the mean squared displacement, although with the
interference of the nearby liquid-glass transition. We also perform novel MCT
calculations using as input the partial structure factors obtained within MD,
confirming the simulation results. The presence of two hard sphere glasses,
differing only in their hard core length, is revealed, showing that the simple
competition between the two is sufficient for creating a rather complex
dynamical behaviour.


title:
Gradient methods for convex minimization: better rates under weaker
  conditions

abstract:
  The convergence behavior of gradient methods for minimizing convex
differentiable functions is one of the core questions in convex optimization.
This paper shows that their well-known complexities can be achieved under
conditions weaker than the commonly accepted ones. We relax the common gradient
Lipschitz-continuity condition and strong convexity condition to ones that hold
only over certain line segments. Specifically, we establish complexities
$O(\frac{R}{\epsilon})$ and $O(\sqrt{\frac{R}{\epsilon}})$ for the ordinary and
accelerate gradient methods, respectively, assuming that $\nabla f$ is
Lipschitz continuous with constant $R$ over the line segment joining $x$ and
$x-\frac{1}{R}\nabla f$ for each $x\in\dom f$. Then we improve them to
$O(\frac{R}{\nu}\log(\frac{1}{\epsilon}))$ and
$O(\sqrt{\frac{R}{\nu}}\log(\frac{1}{\epsilon}))$ for function $f$ that also
satisfies the secant inequality $\ < \nabla f(x), x- x^*\ > \ge \nu\|x-x^*\|^2$
for each $x\in \dom f$ and its projection $x^*$ to the minimizer set of $f$.
The secant condition is also shown to be necessary for the geometric decay of
solution error. Not only are the relaxed conditions met by more functions, the
restrictions give smaller $R$ and larger $\nu$ than they are without the
restrictions and thus lead to better complexity bounds. We apply these results
to sparse optimization and demonstrate a faster algorithm.


title:
Observation of the suppressed ADS modes $B^\pm \to [\pi^\pm K^\mp
  \pi^+\pi^-]_D K^\pm$ and $B^\pm \to [\pi^\pm K^\mp \pi^+\pi^-]_D \pi^\pm$

abstract:
  An analysis of $B^{\pm}\to DK^{\pm}$ and $B^{\pm}\to D\pi^{\pm}$ decays is
presented where the $D$ meson is reconstructed in the four-body final state
$K^{\pm}\pi^{\mp} \pi^+ \pi^-$. Using LHCb data corresponding to an integrated
luminosity of $1.0{\rm \,fb}^{-1}$, first observations are made of the
suppressed ADS modes $B^{\pm}\to [\pi^{\pm} K^{\mp}\pi^+\pi^-]_D K^{\pm}$ and
$B^{\pm}\to [\pi^{\pm} K^{\mp} \pi^+\pi^- ]_D\pi^{\pm}$ with a significance of
$5.1\sigma$ and greater than $10\sigma$, respectively. Measurements of CP
asymmetries and CP-conserving ratios of partial widths from this family of
decays are also performed. The magnitude of the ratio between the suppressed
and favoured $B^{\pm}\to DK^{\pm}$ amplitudes is determined to be $r^K_B =
0.097 \pm{0.011}$.


title:
Observations of Coronal Mass Ejections with the Coronal Multichannel
  Polarimeter

abstract:
  The Coronal Multichannel Polarimeter (CoMP) measures not only the
polarization of coronal emission, but also the full radiance profiles of
coronal emission lines. For the first time, CoMP observations provide
high-cadence image sequences of the coronal line intensity, Doppler shift and
line width simultaneously in a large field of view. By studying the Doppler
shift and line width we may explore more of the physical processes of CME
initiation and propagation. Here we identify a list of CMEs observed by CoMP
and present the first results of these observations. Our preliminary analysis
shows that CMEs are usually associated with greatly increased Doppler shift and
enhanced line width. These new observations provide not only valuable
information to constrain CME models and probe various processes during the
initial propagation of CMEs in the low corona, but also offer a possible
cost-effective and low-risk means of space weather monitoring.


title:
X-ray absorption spectroscopy and magnetic circular dichroism studies of
  L1_0-Mn-Ga thin films

abstract:
  Tetragonally distorted \(\rm{Mn}_{3-x}\rm{Ga}_x\) thin films with \(0.1< x <
2\) show a strong perpendicular magnetic anisotropy and low magnetization and
thus have the potential to serve as electrodes in spin transfer torque magnetic
random access memory. Because a direct capping of these films with MgO is
problematic due to oxide formation, we examined the influence of a CoFeB
interlayer, and of two different deposition methods for the MgO barrier on the
formation of interfacial MnO for \(\rm{Mn}_{62}\rm{Ga}_{38}\) by element
specific X-ray absorption spectroscopy (XAS) and magnetic circular dichroism
(XMCD). A highly textured L1\(_0\) crystal structure of the Mn-Ga films was
verified by X-ray diffraction (XRD) measurements. For samples with e-beam
evaporated MgO barrier no evidence for MnO was found, whereas in samples with
magnetron sputtered MgO MnO was detected, even for the thickest interlayer
thickness. Both XAS and XMCD measurements showed an increasing interfacial MnO
amount with decreasing CoFeB interlayer thickness. Additional element specific
full hysteresis loops determined an out-of-plane magnetization axis for the Mn
and Co, respectively.


title:
The Strong Goldbach Conjecture: Proof for All Even Integers Greater than
  362

abstract:
  The Strong Goldbach conjecture dates back to 1742. It states that every even
integer greater than four can be written as the sum of two prime numbers. Since
then, no one has been able to prove the conjecture. The only best known result
so far is that every sufficiently large even integer N can be written as the
sum of a prime number and the product of at most two prime numbers.
Additionally, the conjecture has been verified to be true for all even integers
up to 4.10^18. In this paper, we prove that the conjecture is true for all even
integers greater than 362.


title: Weak Lensing Measurements in Simulations of Radio Images

abstract:
  We present a study of weak lensing shear measurements for simulated galaxy
images at radio wavelengths. We construct a simulation pipeline into which we
can input galaxy images of known ellipticity, and with which we then simulate
observations with eMERLIN and the international LOFAR array. The simulations
include the effects of the CLEAN algorithm, uv sampling, observing angle, and
visibility noise, and produce realistic restored images of the galaxies. We
apply a shapelet-based shear measurement method to these images and test our
ability to recover the true source ellipticities. We model and deconvolve the
effective PSF, and find suitable parameters for CLEAN and shapelet
decomposition of galaxies. We demonstrate that ellipticities can be measured
faithfully in these radio simulations, with no evidence of an additive bias and
a modest (10%) multiplicative bias on the ellipticity measurements. Our
simulation pipeline can be used to test shear measurement procedures and
systematics for the next generation of radio telescopes.


title: Visualization of the G\"odel universe

abstract:
  The standard model of modern cosmology, which is based on the
Friedmann-Lema\^itre-Robertson-Walker metric, allows the definition of an
absolute time. However, there exist (cosmological) models consistent with the
theory of general relativity for which such a definition cannot be given since
they offer the possibility of time travel. The simplest of these models is the
cosmological solution discovered by Kurt G\"odel, which describes a
homogeneous, rotating universe. Disregarding the paradoxes that come along with
the abolishment of causality in such spacetimes, we are interested in the
purely academical question how an observer would visually perceive the time
travel of an object in G\"odel's universe. For this purpose, we employ the
technique of ray tracing, a standard tool in computer graphics, and visualize
various scenarios to bring out the optical effects experienced by an observer
located in this universe. In this way, we provide a new perspective on the
space-time structure of G\"odel's model.


title: Causal Fermions in Discrete Spacetime

abstract:
  In this paper, we consider fermionic systems in discrete spacetime evolving
with a strict notion of causality, meaning they evolve unitarily and with a
bounded propagation speed. First, we show that the evolution of these systems
has a natural decomposition into a product of local unitaries, which also holds
if we include bosons. Next, we show that causal evolution of fermions in
discrete spacetime can also be viewed as the causal evolution of a lattice of
qubits, meaning these systems can be viewed as quantum cellular automata.
Following this, we discuss some examples of causal fermionic models in discrete
spacetime that become interesting physical systems in the continuum limit:
Dirac fermions in one and three spatial dimensions, Dirac fields and briefly
the Thirring model. Finally, we show that the dynamics of causal fermions in
discrete spacetime can be efficiently simulated on a quantum computer.


title: Nonlinear Electromagnetic Forces in Astrophysics

abstract:
  Electromagnetism becomes a nonlinear theory having (effective) photon-photon
interactions due at least to electron-positron fluctuations in the vacuum. We
discuss the consequences of the nonlinearity for the force felt by a charge
probe particle, and compare the impact of Euler-Kockel QED effective
nonlinearity to the possibility of Born-Infeld-type nonlinearity.


title: Cosmology with sterile neutrino masses from oscillation experiments

abstract:
  There are hints, both from cosmology and from neutrino oscillation
experiments, that one or two sterile neutrinos with eV masses are favored. We
consider the implications of combining data from short baseline neutrino
experiments with cosmological observations. In particular we consider
cosmological models where the equation of state of dark energy and the
curvature are allowed to vary. We find that the consistency of results from
short baseline experiments and cosmology is dependent on the cosmological data
sets that are used. When the two are consistent, we find that the inclusion of
information from short baseline experiments only mildly affects the preferred
values of the cosmological model parameters. A universe with a cosmological
constant type dark energy and zero curvature is still fully consistent with the
data we use. We also report that a thermalized sterile neutrino in the 10 eV
range is fully consistent with a wide range of cosmological data as long as
information on the matter power spectrum in not taken into account.


title:
Absence of Anderson localization of light in a random ensemble of point
  scatterers

abstract:
  As discovered by Philip Anderson in 1958, strong disorder can block
propagation of waves and lead to the localization of wave-like excitations in
space. Anderson localization of light is particularly exciting in view of its
possible applications for random lasing or quantum information processing. We
show that, surprisingly, Anderson localization of light cannot be achieved in a
random three-dimensional ensemble of point scattering centers that is the
simplest and widespread model to study the multiple scattering of waves.
Localization is recovered if the vector character of light is neglected. This
shows that, at least for point scatterers, the polarization of light plays an
important role in the Anderson localization problem.


title:
Comment on 'Evidence for Stratification of Deuterium-Tritium Fuel in
  Inertial Confinement Fusion Implosions'

abstract:
  Recent implosion experiments performed at the OMEGA laser facility reported
by Casey et al.[1], displayed an anomalously low dd proton yield and a high tt
neutron yield as compared to dt fusion reactions, explained as a stratification
of the fuel in the implosion core. We suggest that in the com- pression stage
the fuel is out of equilibrium. Ions are inward accelerated to a velocity v0
independent on the particle type. Yield ratios are simply given by the ratios
of fusion cross-sections obtained at the same velocity. A 'Hubble' type model
gives also a reasonable description of the data. These considerations might be
relevant for implosion experiments at the National Ignition Facility as well.


title: Resonances and poles in the second Riemann sheet

abstract:
  In this work we study basic properties of unstable particles and scalar
hadronic resonances, respectively, within simple quantum mechanical and quantum
field theoretical (effective) models.
  We start with the basic ideas of quantum field theory. In particular, we
introduce the Feynman propagator for unstable scalar resonances and motivate
the idea that this kind of correlation function should possess complex poles
which parameterize the mass and decay width of the considered particle. We also
briefly discuss the problematic scalar sector in particle physics, emphasizing
that hadronic loop contributions dominate its dynamics. A whole chapter is
dedicated to the method of analytic continuation of complex functions through
branch cuts into the so called second Riemann sheet. This method is crucial in
order to describe physics of scalar resonances because the Feynman propagator
of interacting quantum field theories will have branch cuts in the complex
energy plane and complex poles in the second Riemann sheet.
  We then apply these concepts to a simple non-relativistic Lee model and
demonstrate the physical implications, i.e., the motion of the propagator poles
and the behaviour of the spectral function. Besides that, we investigate the
time evolution of a particle described by such a model.
  In the last chapter, we finally concentrate on a simple quantum field
theoretical model which describes the decay of a scalar state into two
(pseudo)scalar ones. It is investigated how the motion of the propagator poles
is influenced by loop contributions of the two (pseudo)scalar particles. We
perform a numerical study for a hadronic system involving a scalar seed state
(alias the \sigma-meson) that couples to pions. The unexpected emergence of a
putative stable state below the two-pion threshold is investigated and it is
clarified under which conditions such a stable state appears.


title:
Multiband Superconductivity of Heavy Electrons in TlNi2Se2 single
  crystal

abstract:
  Superconductivity has been first observed in TlNi$_2$Se$_2$ at T$_C$=3.7 K
and appears to involve heavy electrons with an effective mass $m^*$=14$\sim$20
$m_b$, as inferred from the normal state electronic specific heat and the upper
critical field, H_${C2}$(T). Although the zero-field electronic specific heat
data, $C_{es}(T)$, in low temperatures (T < 1/4 T$_C$) can be fitted with a gap
BCS model, indicating that TlNi$_2$Se$_2$ is a fully gapped superconductor, the
two-gap BCS model presents the best fit to all the $C_{es}(T)$ data below
$T_C$. It is also found that the electronic specific heat coefficient in the
mixed state, $\gamma_N(H)$, exhibits a \textit{H}$^{1/2}$ behavior, which was
also observed in some \textit{s}-wave superconductors, although once considered
as a common feature of the \textit{d}-wave superconductors. Anyway, these
results indicate that TlNi$_2$Se$_2$, as a non-magnetic analogue of
TlFe$_x$Se$_2$ superconductor, is a multiband superconductor of heavy electron
system.


title:
Complementarity of quantum discord and classically accessible
  information

abstract:
  The sum of the Holevo quantity (that bounds the capacity of quantum channels
to transmit classical information about an observable) and the quantum discord
(a measure of the quantumness of correlations of that observable) yields an
observable-independent total given by the quantum mutual information. This
split naturally delineates information about quantum systems accessible to
observers -- information that is redundantly transmitted by the environment --
while showing that it is maximized for the quasi-classical pointer observable.
Other observables are accessible only via correlations with the pointer
observable. Further, we prove an anti-symmetry property relating accessible
information and discord. It shows that information becomes objective --
accessible to many observers -- only as quantum information is relegated to
correlations with the global environment, and, therefore, locally inaccessible.
The resulting complementarity explains why, in a quantum Universe, we perceive
objective classical reality while flagrantly quantum superpositions are out of
reach.


title:
Studying the neutron orbital structure by coherent hard exclusive
  processes off 3He

abstract:
  Hard exclusive processes, such as Deeply Virtual Compton Scattering (DVCS),
allow to access generalized parton distributions (GPDs). By means of an Impulse
Approximation (IA) calculation, it is shown here how, in the low momentum
transfer region, the sum of the GPDs H and E is dominated by the neutron
contribution. Thanks to this property, 3He could open a new way to access the
neutron structure information. In this work, a simple and efficient extraction
procedure of the neutron GPDs, able to take into account the nuclear effects
included in IA analysis, is proposed.


title: Statistics of charge transport and unconventional time ordering

abstract:
  The statistics of charge transport across a tunnel junction with
energy-dependent scattering is investigated. A model with quadratic dispersion
relation is discussed in general and, independently, in the two limiting cases
of a large detector and of a linear dispersion relation. The measurement of
charge takes place according to various protocols. It is found that, as a rule,
the statistics is expressed by means of time-ordered current correlators,
differing however from the conventional ones in the ordering prescription.
Nevertheless binomial statistics is confirmed in all cases.


title:
Equation of state and neutron star properties constrained by nuclear
  physics and observation

abstract:
  Microscopic calculations of neutron matter based on nuclear interactions
derived from chiral effective field theory, combined with the recent
observation of a 1.97 +- 0.04 M_sun neutron star, constrain the equation of
state of neutron-rich matter at sub- and supranuclear densities. We discuss in
detail the allowed equations of state and the impact of our results on the
structure of neutron stars, the crust-core transition density, and the nuclear
symmetry energy. In particular, we show that the predicted range for neutron
star radii is robust. For use in astrophysical simulations, we provide detailed
numerical tables for a representative set of equations of state consistent with
these constraints.


title: Local Theory for 2-Functors on Path 2-Groupoids

abstract:
  In this article we discuss local aspects of 2-functors defined on the path
2-groupoid of a smooth manifold; in particular, local trivializations and
descent data. This is a contribution to a project that provides an axiomatic
formulation of connections on (possibly non-abelian) gerbes in terms of
2-functors. The main result of this paper establishes the first part of this
formulation: we prove an equivalence between the globally defined 2-functors
and their locally defined descent data. The second part appears in a separate
publication; there we prove equivalences between descent data, on one side, and
various existing versions of gerbes with connection on the other side.


title: Large-Scale Learning with Less RAM via Randomization

abstract:
  We reduce the memory footprint of popular large-scale online learning methods
by projecting our weight vector onto a coarse discrete set using randomized
rounding. Compared to standard 32-bit float encodings, this reduces RAM usage
by more than 50% during training and by up to 95% when making predictions from
a fixed model, with almost no loss in accuracy. We also show that randomized
counting can be used to implement per-coordinate learning rates, improving
model quality with little additional RAM. We prove these memory-saving methods
achieve regret guarantees similar to their exact variants. Empirical evaluation
confirms excellent performance, dominating standard approaches across memory
versus accuracy tradeoffs.


title: Multi derivation Maurer-Cartan algebras and sh-Lie-Rinehart algebras

abstract:
  We extend the classical characterization of a finite-dimensional Lie algebra
g in terms of its Maurer-Cartan algebra-the familiar differential graded
algebra of alternating forms on g with values in the ground field, endowed with
the standard Lie algebra cohomology operator-to sh Lie-Rinehart algebras. To
this end, we first develop a characterization of sh Lie-Rinehart algebras in
terms of differential graded cocommutative coalgebras and Lie algebra twisting
cochains that extends the nowadays standard characterization of an ordinary sh
Lie algebra (equivalently: Linfty algebra) in terms of its associated
generalized Cartan-Chevalley-Eilenberg coalgebra. Our approach avoids any
higher brackets but reproduces these brackets in a conceptual manner. The new
technical tool we develop is a notion of filtered multi derivation chain
algebra, somewhat more general than the standard notion of a multicomplex
endowed with a compatible algebra structure. The crucial observation, just as
for ordinary Lie-Rinehart algebras, is this: For a general sh Lie-Rinehart
algebra,the generalized Cartan-Chevalley-Eilenberg operator on the
corresponding graded algebra involves two operators, one coming from the sh Lie
algebra structure and the other from the generalized action on the
corresponding algebra; the sum of the operators is defined on the algebra while
the operators are individually defined only on a larger ambient algebra. We
illustrate the structure with quasi Lie-Rinehart algebras.


title:
The clustering of galaxies in the SDSS-III Baryon Oscillation
  Spectroscopic Survey: Measuring D_A and H at z=0.57 from the Baryon Acoustic
  Peak in the Data Release 9 Spectroscopic Galaxy Sample

abstract:
  We present measurements of the angular diameter distance to and Hubble
parameter at z=0.57 from the measurement of the baryon acoustic peak in the
correlation of galaxies from the Sloan Digital Sky Survey III Baryon
Oscillation Spectroscopic Survey. Our analysis is based on a sample from Data
Release 9 of 264,283 galaxies over 3275 square degrees in the redshift range
0.43<z<0.70. We use two different methods to provide robust measurement of the
acoustic peak position across and along the line of sight in order to measure
the cosmological distance scale. We find D_A(0.57) = 1408 +/- 45 Mpc and
H(0.57) = 92.9 +/- 7.8 km/s/Mpc for our fiducial value of the sound horizon.
These results from the anisotropic fitting are fully consistent with the
analysis of the spherically averaged acoustic peak position presented in
Anderson et al, 2012. Our distance measurements are a close match to the
predictions of the standard cosmological model featuring a cosmological
constant and zero spatial curvature.


title: Reactor On-Off Antineutrino Measurement with KamLAND

abstract:
  The recent long-term shutdown of Japanese nuclear reactors has resulted in a
significantly reduced reactor $\bar{nu}_{e}$ flux at KamLAND. This running
condition provides a unique opportunity to confirm and constrain backgrounds
for the reactor $\bar{nu}_{e}$ oscillation analysis. The data set also has
improved sensitivity for other $\bar{nu}_{e}$ signals, in particular
$\bar{nu}_{e}$'s produced in $\beta$-decays from $^{238}$U and $^{232}$Th
within the Earth's interior, whose energy spectrum overlaps with that of
reactor $\bar{nu}_{e}$'s. Including constraints on $\theta_{13}$ from
accelerator and short-baseline reactor neutrino experiments, a combined
three-flavor analysis of solar and KamLAND data gives fit values for the
oscillation parameters of $tan^{2} \theta_{12} = 0.436^{+0.029}_{-0.025}$,
$\Delta m^{2}_{21} = 7.53^{+0.18}_{-0.18} \times 10^{-5} {eV}^{2}$, and
$sin^{2} \theta_{13} = 0.023^{+0.002}_{-0.002}$. Assuming a chondritic Th/U
mass ratio, we obtain $116^{+28}_{-27}$ $\bar{nu}_{e}$ events from $^{238}$U
and $^{232}$Th, corresponding to a geo $\bar{nu}_{e}$ flux of
$3.4^{+0.8}_{-0.8} \times 10^{6} {cm^{-2}s^{-1}}$ at the KamLAND location. We
evaluate various bulk silicate Earth composition models using the observed geo
$\bar{nu}_{e}$ rate.


title: Localization theorems for nonlinear eigenvalue problems

abstract:
  Let $T : \Omega \rightarrow \bbC^{n \times n}$ be a matrix-valued function
that is analytic on some simply-connected domain $\Omega \subset \bbC$. A point
$\lambda \in \Omega$ is an eigenvalue if the matrix $T(\lambda)$ is singular.
In this paper, we describe new localization results for nonlinear eigenvalue
problems that generalize Gershgorin's theorem, pseudospectral inclusion
theorems, and the Bauer-Fike theorem. We use our results to analyze three
nonlinear eigenvalue problems: an example from delay differential equations, a
problem due to Hadeler, and a quantum resonance computation.


title: A Whirlwind Tour of the World of $(\infty,1)$-categories

abstract:
  This introduction to higher category theory is intended to a give the reader
an intuition for what $(\infty,1)$-categories are, when they are an appropriate
tool, how they fit into the landscape of higher category, how concepts from
ordinary category theory generalize to this new setting, and what uses people
have put the theory to. It is a rough guide to a vast terrain, focuses on ideas
and motivation, omits almost all proofs and technical details, and provides
many references.


title: Automorphisms of hyperk\"ahler manifolds

abstract:
  The present paper provides several results on automorphisms of hyperk\"ahler
(or irreducible holomorphic symplectic) manifolds. In particular it focuses on
the symplectic case and contains a classification of prime order symplectic
automorphisms on deformations of the Hilbert scheme of two points on a K3
surface and, with additional hypothesis, also on Hilbert schemes of n points on
a K3 surface. We also give numerical conditions to establish whether a
symplectic automorfism of order 2,3 and 5 on a deformation of the Hilbert
scheme of two points on a K3 surface is standard. Moreover we also give various
examples.


title: Soft X-ray follow-up of five hard X-ray emitters

abstract:
  We studied the soft-X-ray emission of five hard-X sources: IGR J08262-3736,
IGR J17354-3255, IGR J16328-4726, SAX J1818.6-1703 and IGR J17348-2045. These
sources are: a confirmed supergiant high mass X-ray binary (IGR J08262-3736);
candidates (IGR J17354-3255, IGR J16328- 4726) and confirmed (SAX J1818.6-1703)
supergiant fast X-ray transients; IGR J17348-2045 is one of the as-yet
unidentified objects discovered with INTEGRAL. Thanks to dedicated XMM-Newton
observations, we obtained the first detailed soft X-ray spectral and timing
study of IGR J08262-3736. The results obtained from the observations of IGR
J17354-3255 and IGR J16328-4726 provided further support in favor of their
association with the class of Supergiant Fast X-ray Transients. SAX
J1818.6-1703, observed close to phase 0.5, was not detected by XMM-Newton, thus
supporting the idea that this source reaches its lowest X-ray luminosity
(~10^32 erg/s) around apastron. For IGR J17348-2045 we identified for the first
time the soft X-ray counterpart and proposed the association with a close-by
radio object, suggestive of an extragalactic origin. In this proceeding we
discuss the results obtained from the XMM-Newton follow-up observations of all
the five sources.


title:
Strategic Intelligence on Emerging Technologies: Scientometric Overlay
  Mapping

abstract:
  This paper examines the use of scientometric overlay mapping as a tool of
'strategic intelligence' to aid the governance of emerging technologies. We
develop an integrative synthesis of different overlay mapping techniques and
associated perspectives on technological emergence across the geographical,
social, and cognitive spaces. To do so, we longitudinally analyse (with
publication and patent data) three case-studies of emerging technologies in the
medical domain. These are: RNA interference (RNAi), Human Papilloma Virus (HPV)
testing technologies for cervical cancer, and Thiopurine Methyltransferase
(TPMT) genetic testing. Given the flexibility (i.e. adaptability to different
sources of data) and granularity (i.e. applicability across multiple levels of
data aggregation) of overlay mapping techniques, we argue that these techniques
can favour the integration and comparison of results from different contexts
and cases, thus potentially functioning as platform for a 'distributed'
strategic intelligence for analysts and decision-makers.


title: Geometric achromatic and pseudoachromatic indices

abstract:
  The pseudoachromatic index of a graph is the maximum number of colors that
can be assigned to its edges, such that each pair of different colors is
incident to a common vertex. If for each vertex its incident edges have
different color, then this maximum is known as achromatic index. Both indices
have been widely studied. A geometric graph is a graph drawn in the plane such
that its vertices are points in general position, and its edges are
straight-line segments. In this paper we extend the notion of pseudoachromatic
and achromatic indices for geometric graphs, and present results for complete
geometric graphs. In particular, we show that for $n$ points in convex position
the achromatic index and the pseudoachromatic index of the complete geometric
graph are $\lfloor \tfrac{n^2+n}{4} \rfloor$.


title:
An optimized chiral nucleon-nucleon interaction at
  next-to-next-to-leading order

abstract:
  We optimize the nucleon-nucleon interaction from chiral effective field
theory at next-to-next- to-leading order. The resulting new chiral force
NNLOopt yields \chi^2 \approx 1 per degree of freedom for laboratory energies
below approximately 125 MeV. In the A = 3, 4 nucleon systems, the contributions
of three-nucleon forces are smaller than for previous parametrizations of
chiral interactions. We use NNLOopt to study properties of key nuclei and
neutron matter, and demonstrate that many aspects of nuclear structure can be
understood in terms of this nucleon-nucleon interaction, without explicitly
invoking three-nucleon forces.


title: Electronic structure of relativistic Mott insulator Li$_2$RhO$_3$

abstract:
  Motivated by studies of coexisting electron correlation and spin-orbit
coupling effect in Na$_2$IrO$_3$ and a recent experiment of its 4d analogue
Li$_2$RhO$_3$, we performed first-principles calculations of the rhodium oxide
compound. The experimentally observed ground state of Li$_2$RhO$_3$ can be
recovered only if both spin-orbit coupling and on-site Coulomb interaction are
taken into consideration. Within the proper $U$ range for 4d-orbitals
($2\leqslant U\leqslant 4$ eV), the ground state of Li$_2$RhO$_3$ could be
either zigzag-AFM or stripy-AFM, both yielding energy gap close to experimental
observation. Furthermore, the total energy differences between the competing
magnetic phases are $\leqslant 3$ meV/Rh within $2\leqslant U\leqslant 4$ eV,
manifesting strong magnetic frustration in the compound. Finally, the phase
energy of Li$_2$RhO$_3$ cannot be fitted with the two-dimensional
Heisenberg-Kitaev model involving only the nearest neighbor interactions, and
we propose that inter-layer interactions may be responsible for the
discrepancy.


title: Universal Doomsday: Analyzing Our Prospects for Survival

abstract:
  Given a sufficiently large universe, numerous civilizations almost surely
exist. Some of these civilizations will be short-lived and die out relatively
early in their development, i.e., before having the chance to spread to other
planets. Others will be long-lived, potentially colonizing their galaxy and
becoming enormous in size. What fraction of civilizations in the universe are
long-lived? The "universal doomsday" argument states that long-lived
civilizations must be rare because if they were not, we should find ourselves
living in one. Furthermore, because long-lived civilizations are rare, our
civilization's prospects for long-term survival are poor. Here, we develop the
formalism required for universal doomsday calculations and show that while the
argument has some force, our future is not as gloomy as the traditional
doomsday argument would suggest, at least when the number of early existential
threats is small.


title:
Determining White Noise Forcing From Eulerian Observations in the Navier
  Stokes Equation

abstract:
  The Bayesian approach to inverse problems is of paramount importance in
quantifying uncertainty about the input to and the state of a system of
interest given noisy observations. Herein we consider the forward problem of
the forced 2D Navier Stokes equation. The inverse problem is inference of the
forcing, and possibly the initial condition, given noisy observations of the
velocity field. We place a prior on the forcing which is in the form of a
spatially correlated temporally white Gaussian process, and formulate the
inverse problem for the posterior distribution. Given appropriate spatial
regularity conditions, we show that the solution is a continuous function of
the forcing. Hence, for appropriately chosen spatial regularity in the prior,
the posterior distribution on the forcing is absolutely continuous with respect
to the prior and is hence well-defined. Furthermore, the posterior distribution
is a continuous function of the data. We complement this theoretical result
with numerical simulation of the posterior distribution.


title: Influence of Reheating on the Trispectrum and its Scale Dependence

abstract:
  We study the evolution of the non-linear curvature perturbation during
perturbative reheating, and hence how observables evolve to their final values
which we may compare against observations. Our study includes the evolution of
the two trispectrum parameters, $\gnl$ and $\taunl$, as well as the scale
dependence of both $\fnl$ and $\taunl$. In general the evolution is significant
and must be taken into account, which means that models of multifield inflation
cannot be compared to observations without specifying how the subsequent
reheating takes place. If the trispectrum is large at the end of inflation, it
normally remains large at the end of reheating. In the classes of models we
study, it is very hard to generate $\taunl\gg\fnl^2$, regardless of the decay
rates of the fields. Similarly, for the classes of models in which
$\gnl\simeq\taunl$ during slow--roll inflation, we find the relation typically
remains valid during reheating. Therefore it is possible to observationally
test such classes of models without specifying the parameters of reheating,
even though the individual observables are sensitive to the details of
reheating. It is hard to generate an observably large $\gnl$ however. The
runnings, $\nfnl$ and $\ntaunl$, tend to satisfy a consistency relation
$\ntaunl=(3/2)\nfnl$, but are in general too small to be observed for the class
of models considered regardless of reheating timescale.


title:
Hybrid DEEC: Towards Efficient Energy Utilization in Wireless Sensor
  Networks

abstract:
  The clustering algorithm are considered as a kind of key technique used to
reduce energy consumption. It can help in increasing the stability period and
network life time. Routing protocol for efficient energy utilization should be
designed for heterogeneous Wireless Sensor Networks (WSNs). We purpose
Hybrid-DEEC (H-DEEC), a chain and cluster based (hybrid) distributed scheme for
efficient energy utilization in WSNs. In H-DEEC,elected Cluster Heads (CHs)
communicate the Base Station (BS) through beta elected nodes, by using
multi-hopping. We logically divide the network into two parts, on the basis of
the residual energy of nodes. The normal nodes with high initial and residual
energy will behighlyprobable to be CHs than the nodes with lesser energy. To
overcome the deficiencies of H-DEEC, we propose Multi-Edged Hybrid-DEEC
(MH-DEEC). In MH-DEEC the criteria of chain construction is modified. Finally,
the comparison in simulation results with other heterogeneous protocols show
that, MH-DEEC and H-DEEC achieves longer stability time and network life time
due to efficient energy utilization.


title: On the linearity defect of the residue field

abstract:
  Given a commutative Noetherian local ring $R$, the linearity defect of a
finitely generated $R$-module $M$, denoted $\ld_R(M)$, is an invariant that
measures how far $M$ and its syzygies are from having a linear resolution.
Motivated by a positive known answer in the graded case, we study the question
of whether $\ld_R(k)<\infty$ implies $\ld_R(k)=0$. We give answers in special
cases, and we discuss several interpretations and refinements of the question.


title:
Analytical Hot Spot Shapes and Magnetospheric Radius from 3D Simulations
  of Magnetospheric Accretion

abstract:
  We present an analytical formula for the position and shape of the spots on
the surface of accreting magnetized stars in cases where a star has a dipole
magnetic field tilted at a small misalignment angle Theta < 30 degrees about
the rotational axis, and the magnetosphere is 2.5-5 times the radius of the
star. We observed that the azimuthal position of the spots varies significantly
when the position of the inner disc varies. In contrast, the polar position of
the spots varies only slightly because of the compression of the magnetosphere.
The azimuthal width of the spots strongly varies with Theta: spots have the
shape of an arc at larger misalignment angles, and resemble a ring at very
small misalignment angles. The polar width of the spots varies only slightly
with changes in parameters. The motion of the spots in the azimuthal direction
can provide phase-shifts in accreting millisecond pulsars, and the "drift" of
the period in Classical T Tauri stars. The position and shape of the spots are
determined by three parameters: misalignment angle Theta; normalized corotation
radius, r_c/R_* and normalized magnetospheric radius, r_m/R_*, where R_* is the
stellar radius.
  We also use our data to check the formula for the Alfv\'en radius, where the
main dependencies are r_m \sim (\mu^2/\dot M)^{2/7}, where \mu is the magnetic
moment of the star, and \dot M is the accretion rate. We found that the
dependence is more gradual, r_m \sim (\mu^2/\dot M)^{1/5}, which can be
explained by the compression of the magnetosphere by the disc matter and by the
non-dipole shape of the magnetic field lines of the external magnetosphere.


title: Universal Two-body Physics in Dark Matter near an S-wave Resonance

abstract:
  The dark matter annihilation rate at small relative velocities can be
amplified by a large boost factor using various mechanisms, including
Sommerfeld enhancement, resonance enhancement, and Breit-Wigner enhancement.
These mechanisms all involve a resonance near the threshold for a pair of dark
matter particles. We point out that if the resonance is in the S-wave channel,
the mechanisms are equivalent sufficiently near the resonance and they are
constrained by universal two-body physics. The amplified annihilation rate
requires a corresponding amplification of the elastic scattering cross section.
If the resonance is a bound state below the threshold, it has an increased
lifetime that is inversely proportional to the square root of the binding
energy. Its spatial structure is that of two dark matter particles whose mean
separation is also inversely proportional to the square root of the binding
energy.


title:
Alternating Rate Profile Optimization in Single Stream MIMO Interference
  Channels

abstract:
  The multiple-input multiple-output interference channel is considered with
perfect channel information at the transmitters and single-user decoding
receivers. With all transmissions restricted to single stream beamforming, we
consider the problem of finding all Pareto optimal rate-tuples in the
achievable rate region. The problem is cast as a rate profile optimization
problem. Due to its nonconvexity, we resort to an alternating approach: For
fixed receivers, optimal transmission is known. For fixed transmitters, we show
that optimal receive beamforming is a solution to an inverse field of values
problem. We prove the solution's stationarity and compare it with existing
approaches.


title: A dichotomy for the stability of arithmetic progressions

abstract:
  Let H stand for the set of homeomorphisms on [0,1]. We prove the following
dichotomy for Borel subsets A of [0,1]: either there exists a homeomorphism f
in H such that the image f(A) contains no 3-term arithmetic progressions; or,
for every f in H, the image f(A) contains arithmetic progressions of arbitrary
finite length.
  In fact, we show that the first alternative holds if and only if the set A is
meager (a countable union of nowhere dense sets).


title: Updated CMB, X- and gamma-ray constraints on majoron dark matter

abstract:
  The majoron provides an attractive dark matter candidate, directly associated
to the mechanism responsible for spontaneous neutrino mass generation within
the standard model framework. Here we update the cosmological and astrophysical
constraints on majoron dark matter which come from the Cosmic Microwave
Background (CMB) and a variety of X- and gamma-ray observations.


title: Entanglement Generation is Not Necessary for Optimal Work Extraction

abstract:
  We consider reversible work extraction from identical quantum batteries. From
an ensemble of individually passive states, work can be produced only via
global unitary (and thus entangling) operations. However, we show here that
there always exists a method to extract all possible work without creating any
entanglement, at the price of generically requiring more operations (i.e.
additional time). We then study faster methods to extract work and provide a
quantitative relation between the amount of generated multipartite entanglement
and extractable work. Our results suggest a general relation between
entanglement generation and the power of work extraction.


title: A Fourth Neutrino and its Consequences on CP Asymmetries

abstract:
  A general analysis of the consequences of including a fourth neutrino in the
standard model matter content, on CP violating observables at neutrino
oscillation experiments, is presented. Neutrino oscillations in vacuum and with
matter effects are studied. For the former we update and generalize previous
studies on CP asymmetries with an additional active neutrino using an updated
fit of the PMNS mixing matrix. We study the values of the new CP violating
phases which maximize the different CP asymmetries in T2K and MINOS-like setups
aiming to elucidate if the new phases yield measurable effects in the most
favorable case. We show that due to a combined effect of kinematics and
unitarity it is possible to obtain an observable asymmetry in the survival
channels without violating CPT. For the MINOS-like setup, we find maximum
asymmetries in vacuum of the order of 2% and 4% for the $\nu_\mu \to \nu_e$ and
$\nu_e \to \nu_\tau$ channels respectively. For the T2K-like setup we obtain
maximum asymmetries of the order of 6% in the survival $\nu_\mu \to \nu_\mu$
channel. Tree level matter effects enhance the former reaching asymmetries of
the order of 10% for the $\nu_\mu \to \nu_e$ and $\nu_e \to \nu_\tau$ channels,
while the $\nu_\mu \to \nu_\mu$ survival channel changes slightly depending on
the mass hierarchy. Box diagrams with the fourth mass eigenstate as a virtual
particle were also considered, the corrections to the scattering amplitude
being negligible.


title:
Fundamental properties of nearby stars and the consequences on
  DeltaY/DeltaZ

abstract:
  One of the greatest difficulties in astrophysics is the determination of the
fundamental stellar parameters (FSPs), one of which is the initial mass
fraction of helium (Y). However, given that Y can be measured spectroscopically
in only a small percentage of stars, a linear relationship is assumed between Y
and the mass fraction of metals (Z). This Y-Z relation is generally represented
as Y=Yp+DY/DZxZ, with the value of the helium-to-metal enrichment ratio (DY/DZ)
assumed as a constant. However, there is no fundamental reason for every star
to have a Y value on a linear scale with Z. In this paper a method for
determining the FSPs of nearby stars is presented that uses at the same time
Mbol, Teff, and log g. One of these parameters is Y, which is used to determine
the validity of the Y-Z relation. A new set of evolutionary tracks is created
using the PGPUC stellar evolution code, which includes 7 masses
(0.5<M/Msun<1.1), 7 helium abundances (0.230<Y<0.370), and 12 metallicities
(1.6x10^-4<Z<6.0x10^-2) for solar-scaled chemical compositions
([alpha/Fe]=0.0). The suggested method is tested using two different
spectroscopic databases of nearby main sequence stars with precise parallaxes,
and spectroscopic measurements of [Fe/H], Teff and g. The proposed method is
compared to other techniques used to determine the FSPs, where one assumes an
age of 5 Gyr for all nearby stars. This comparison demonstrates that the
hypothesis regarding constant age leads to an underestimation of the Y value,
especially for low metallicities. In addition, the suggested method is limited
to masses above 0.60 Msun and requires high-precision measurements of
spectroscopic surface gravities in order to obtain reliable results. Finally,
estimating masses and ages assuming a Y-Z relation rather than a free Y value
may induce average errors of approximately 0.02 Msun and 2 Gyr, respectively.


title: Dissipation induced non-Gaussian energy fluctuations

abstract:
  The influence of dissipation on the fluctuation statistics of the total
energy is investigated through both a phenomenological and a stochastic model
for dissipative energy-transfer through a cascade of states. In equilibrium the
states obey equipartition and the total energy obeys the central limit theorem,
giving Gaussian fluctuations. In the presence of dissipation, the fluctuations
can be driven non-Gaussian if there is macroscopic energy transfer from large
to small scales. We are thus able to equate the non-Gaussian order parameter
fluctuations in model equilibrium systems at criticality with energy
fluctuations in these dissipative systems. Energy fluctuations in the
phenomenological model map directly onto the 1/f^alpha noise problem and
numerical simulations of the stochastic model yield results in qualitative
agreement with these predictions.


title: Information Theoretic Resources in Quantum Theory

abstract:
  Resource identification and quantification is an essential element of both
classical and quantum information theory. Entanglement is one of these
resources, arising when quantum communication and nonlocal operations are
expensive to perform. In the first part of this thesis we quantify the
effective entanglement when operations are additionally restricted. For an
important class of errors we find a linear relationship between the usual and
effective higher dimensional generalization of concurrence, a measure of
entanglement.
  In the second chapter we focus on nonlocality in the presence of
superselection rules, where we propose a scheme that may be used to activate
nongenuinely multipartite nonlocality with multiple copies of the state. We
show that whenever the number of particles is insufficient, the genuinely
multipartite nonlocality is degraded to nongenuinely multipartite.
  While in the first few chapters we focus on understanding the resources
present in quantum states, in the final part we turn the picture around and
instead treat operations themselves as a resource. We provide our observers
with free access to classical operations - ie. those that cannot detect or
generate quantum coherence. We show that the operation of interest can then be
used to either generate or detect quantum coherence if and only if it violates
a particular commutation relation. Using the relative entropy, the commutation
relation provides us with a measure of nonclassicality of operations. We show
that the measure is a sum of two contributions, the generating power and the
distinguishing power, each of which is separately an essential ingredient in
quantum communication and information processing. The measure also sheds light
on the operational meaning of quantum discord, which we show can be interpreted
as the difference in superdense coding capacity between a quantum state and a
classical state.


title: Threshold values of autoresonant pumping

abstract:
  There exists stable growing solution of primary resonant equation for a
autoresonant pumping with decreasing amplitude. The primary term of asymptotics
is $O(\sqrt{t})$ and does not depend on order of the force from some interval.
We point to the interval for the amplitude of the pumping for which the growing
stable solution exists.


title:
Crowd Simulation Modeling Applied to Emergency and Evacuation
  Simulations using Multi-Agent Systems

abstract:
  In recent years crowd modeling has become increasingly important both in the
computer games industry and in emergency simulation. This paper discusses some
aspects of what has been accomplished in this field, from social sciences to
the computer implementation of modeling and simulation. Problem overview is
described including some of the most common techniques used. Multi-Agent
Systems is stated as the preferred approach for emergency evacuation
simulations. A framework is proposed based on the work of Fangqin and Aizhu
with extensions to include some BDI aspects. Future work includes expansion of
the model's features and implementation of a prototype for validation of the
propose methodology.


title: EAPESS: An Adaptive Transmission Scheme in Wireless Sensor Networks

abstract:
  Reduced energy consumption in sensor nodes is one of the major challenges in
Wireless Sensor Networks (WSNs) deployment. In this regard, Error Control
Coding (ECC) is one of techniques used for energy optimization in WSNs.
Similarly, critical distance is another term being used for energy efficiency,
when used with ECC provides better results of energy saving. In this paper
three different critical distance values are used against different coding
gains for sake of energy saving. If distance lies below critical distance
values then particular encoders are selected with respect to their particular
coding gains. Coding gains are used for critical distances estimation of all
encoders. This adaptive encoder and transmit power selection scheme with
respect to their coding gain results in a significant energy saving in WSNs
environment. Simulations provide better results of energy saving achieved by
using this adaptive scheme.


title: Recovering Non-negative and Combined Sparse Representations

abstract:
  The non-negative solution to an underdetermined linear system can be uniquely
recovered sometimes, even without imposing any additional sparsity constraints.
In this paper, we derive conditions under which a unique non-negative solution
for such a system can exist, based on the theory of polytopes. Furthermore, we
develop the paradigm of combined sparse representations, where only a part of
the coefficient vector is constrained to be non-negative, and the rest is
unconstrained (general). We analyze the recovery of the unique, sparsest
solution, for combined representations, under three different cases of
coefficient support knowledge: (a) the non-zero supports of non-negative and
general coefficients are known, (b) the non-zero support of general
coefficients alone is known, and (c) both the non-zero supports are unknown.
For case (c), we propose the combined orthogonal matching pursuit algorithm for
coefficient recovery and derive the deterministic sparsity threshold under
which recovery of the unique, sparsest coefficient vector is possible. We
quantify the order complexity of the algorithms, and examine their performance
in exact and approximate recovery of coefficients under various conditions of
noise. Furthermore, we also obtain their empirical phase transition
characteristics. We show that the basis pursuit algorithm, with partial
non-negative constraints, and the proposed greedy algorithm perform better in
recovering the unique sparse representation when compared to their
unconstrained counterparts. Finally, we demonstrate the utility of the proposed
methods in recovering images corrupted by saturation noise.


title: NetLogo Implementation of an Evacuation Scenario

abstract:
  The problem of evacuating crowded closed spaces, such as discotheques, public
exhibition pavilions or concert houses, has become increasingly important and
gained attention both from practitioners and from public authorities. A
simulation implementation using NetLogo, an agent-based simulation framework
that permits the quickly creation of prototypes, is presented. Our aim is to
prove that this model developed using NetLogo, albeit simple can be expanded
and adapted for fire safety experts test various scenarios and validate the
outcome of their design. Some preliminary experiments are carried out, whose
results are presented, validated and discussed so as to illustrate their
efficiency. Finally, we draw some conclusions and point out ways in which this
work can be further extended.


title: Using UWB for Human Trajectory Extraction

abstract:
  In this paper we report on a methodology to model pedestrian behaviours
whilst aggregate variables are concerned, with potential applications to
different situations, such as evacuating a building in emergency events. The
approach consists of using UWB (ultra-wide band) based data collection to
characterise behaviour in specific scenarios. From a number of experiments
carried out, we detail the single-file scenario to demonstrate the ability of
this approach to represent macroscopic characteristics of the pedestrian flow.
Results are discussed and we can conclude that UWB-based data collection shows
great potential and suitability for human trajectory extraction, when compared
to other traditional approaches.


title:
Interplay between radiation pressure force and scattered light intensity
  in the cooperative scattering by cold atoms

abstract:
  The interplay between the superradiant emission of a cloud of cold two-level
atoms and the radiation pressure force is discussed. Using a microscopic model
of coupled atomic dipoles driven by an external laser, the radiation field and
the average radiation pressure force are derived. A relation between the
far-field scattered intensity and the force is derived, using the optical
theorem. Finally, the scaling of the sample scattering cross section with the
parameters of the system is studied.


title: Time-scaled scenario of low-energy heavy-ion collisions

abstract:
  The underlying scenario of low-energy heavy-ion collisions is presented based
on time-dependent density-functional calculations. A classification of several
types of reaction dynamics is given with respect to their time-scales.


title:
Discovering link communities in complex networks by exploiting link
  dynamics

abstract:
  Discovery of communities in complex networks is a fundamental data analysis
problem with applications in various domains. Most of the existing approaches
have focused on discovering communities of nodes, while recent studies have
shown great advantages and utilities of the knowledge of communities of links
in networks. From this new perspective, we propose a link dynamics based
algorithm, called UELC, for identifying link communities of networks. In UELC,
the stochastic process of a link-node-link random walk is employed to unfold an
embedded bipartition structure of links in a network. The local mixing
properties of the Markov chain underlying the random walk are then utilized to
extract two emerged link communities. Further, the random walk and the
bipartitioning processes are wrapped in an iterative subdivision strategy to
recursively identify link partitions that segregate the network links into
multiple subdivisions. We evaluate the performance of the new method on
synthetic benchmarks and demonstrate its utility on real-world networks. Our
experimental results show that our method is highly effective for discovering
link communities in complex networks. As a comparison, we also extend UELC to
extracting communities of node, and show that it is effective for node
community identification.


title: Cosmon inflation

abstract:
  The cosmon field responsible for dynamical dark energy can induce an
inflationary period in early cosmology. Details depend on dilatation symmetry
breaking terms in its potential and kinetic term that are relevant only during
early stages of the evolution of the universe. For a large range of parameters
we find realistic primordial density fluctuations. As a particular example we
discuss a model with almost static geometry in the Jordan frame for all epochs
of cosmology. Here the cosmic evolution of the Hubble parameter is replaced by
a variation of the Planck mass and particle masses. This model predicts a
spectral index $n=0.97$ and a ratio for tensor to scalar fluctuations $r=0.13$.


title:
The critical exponent conjecture for powers of doubly nonnegative
  matrices

abstract:
  Doubly non-negative matrices arise naturally in many setting including Markov
random fields (positively banded graphical models) and in the convergence
analysis of Markov chains. In this short note, we settle a recent conjecture by
C.R. Johnson et al. [Linear Algebra Appl. 435 (2011)] by proving that the
critical exponent beyond which all continuous conventional powers of $n$-by-$n$
doubly nonnegative matrices are doubly nonnegative is exactly $n-2$. We show
that the conjecture follows immediately by applying a general characterization
from the literature. We prove a stronger form of the conjecture by classifying
all powers preserving doubly nonnegative matrices, and proceed to generalize
the conjecture for broad classes of functions. We also provide different
approaches for settling the original conjecture.


title:
MJ no more: Using Concurrent Wikipedia Edit Spikes with Social Network
  Plausibility Checks for Breaking News Detection

abstract:
  We have developed an application called Wikipedia Live Monitor that monitors
article edits on different language versions of Wikipedia, as they happen in
realtime. Wikipedia articles in different languages are highly interlinked. For
example, the English article en:2013_Russian_meteor_event on the topic of the
February 15 meteoroid that exploded over the region of Chelyabinsk Oblast,
Russia, is interlinked with the Russian article on the same topic. As we
monitor multiple language versions of Wikipedia in parallel, we can exploit
this fact to detect concurrent edit spikes of Wikipedia articles covering the
same topics, both in only one, and in different languages. We treat such
concurrent edit spikes as signals for potential breaking news events, whose
plausibility we then check with full-text cross-language searches on multiple
social networks. Unlike the reverse approach of monitoring social networks
first, and potentially checking plausibility on Wikipedia second, the approach
proposed in this paper has the advantage of being less prone to false-positive
alerts, while being equally sensitive to true-positive events, however, at only
a fraction of the processing cost.


title: Cosmic inflation in a landscape of heavy-fields

abstract:
  Heavy isocurvature fields may have a strong influence on the low energy
dynamics of curvature perturbations during inflation, as long as the
inflationary trajectory becomes non-geodesic in the multi-field target space
(the landscape). If fields orthogonal to the inflationary trajectory are
sufficiently heavy, one expects a reliable effective field theory describing
the low energy dynamics of curvature perturbations, with self-interactions
determined by the shape of the inflationary trajectory. Previous work analyzing
the role of heavy-fields during inflation have mostly focused in the effects on
curvature perturbations due to a single heavy-field. In this article we extend
the results of these works by studying models of inflation in which curvature
perturbations interact with two heavy-fields. We show that the second
heavy-field (orthogonal to both tangent and normal directions of the
inflationary trajectory) may significantly affect the evolution of curvature
modes. We compute the effective field theory for the low energy curvature
perturbations obtained by integrating out the two heavy-fields and show that
the presence of the second heavy-field implies the existence of additional
self-interactions not accounted for in the single heavy-field case. We conclude
that future observations will be able to constrain the number of heavy fields
interacting with curvature perturbations.


title:
Anisotropic magnetoresistance in antiferromagnetic semiconductor Sr2IrO4
  epitaxial heterostructure

abstract:
  Lord Kelvin with his discovery of the anisotropic magnetoresistance (AMR)
phenomenon in Ni and Fe was 70 years ahead of the formulation of relativistic
quantum mechanics the effect stems from, and almost one and a half century
ahead of spintronics whose first commercial applications relied on the AMR.
Despite the long history and importance in magnetic sensing and memory
technologies, the microscopic understanding of the AMR has struggled to go far
beyond the basic notion of a relativistic magnetotransport phenomenon arising
from combined effects on diffusing carriers of spin-orbit coupling and broken
symmetry of a metallic ferromagnet. Our work demonstrates that even this
seemingly generic notion of the AMR phenomenon needs revisiting as we observe
the ohmic AMR effect in a nano-scale film of an antiferromagnetic (AFM)
semiconductor Sr2IrO4 (SIO). Our work opens the recently proposed path for
integrating semiconducting and spintronic technologies in AFMs. SIO is a
particularly favorable material for exploring this path since its
semiconducting nature is entangled with the AFM order and strong spin-orbit
coupling. For the observation of the low-field Ohmic AMR in SIO we prepared an
epitaxial heterostructure comprising a nano-scale SIO film on top of an
epilayer of a FM metal La2/3Sr1/3MnO3 (LSMO). This allows the magnetic field
control of the orientation of AFM spins in SIO via the exchange spring effect
at the FM-AFM interface.


title: Heavy tails in multi-server queues

abstract:
  In this paper, the asymptotic behaviour of the distribution tail of the
stationary waiting time $W$ in the $GI/GI/2$ FCFS queue is studied. Under
subexponential-type assumptions on the service time distribution, bounds and
sharp asymptotics are given for the probability ${\bf P}\{W>x\}$. We also get
asymptotics for the distribution tail of a stationary two-dimensional workload
vector and of a stationary queue length. These asymptotics depend heavily on
the traffic load.