title:
Effect of Interactions on Vortices in a Non-equilibrium Polariton
  Condensate

abstract:
  We demonstrate the creation of vortices in a macroscopically occupied
polariton state formed in a semiconductor microcavity. A weak external laser
beam carrying orbital angular momentum (OAM) is used to imprint a vortex on the
condensate arising from the polariton optical parametric oscillator (OPO). The
vortex core radius is found to decrease with increasing pump power, and is
determined by polariton-polariton interactions. As a result of OAM conservation
in the parametric scattering process, the excitation consists of a vortex in
the signal and a corresponding anti-vortex in the idler of the OPO. The
experimental results are in good agreement with a theoretical model of a vortex
in the polariton OPO.


title: Geometric Results for Compressible Magnetohydrodynamics

abstract:
  Recently, compressible magnetohydrodynamics (MHD) has been elegantly
formulated in terms of Lie derivatives. This paper exploits the geometrical
properties of the Lie bracket to give new insights into the properties of
compressible MHD behaviour, both with and without feedback of the magnetic
field on the flow. These results are expected to be useful for the solution of
MHD equations in both tokamak fusion experiments and space plasmas.


title:
Analysis of Optimization Techniques to Improve User Response Time of Web
  Applications and Their Implementation for MOODLE

abstract:
  Analysis of seven optimization techniques grouped under three categories
(hardware, back-end, and front-end) is done to study the reduction in average
user response time for Modular Object Oriented Dynamic Learning Environment
(Moodle), a Learning Management System which is scripted in PHP5, runs on
Apache web server and utilizes MySQL database software. Before the
implementation of these techniques, performance analysis of Moodle is performed
for varying number of concurrent users. The results obtained for each
optimization technique are then reported in a tabular format. The maximum
reduction in end user response time was achieved for hardware optimization
which requires Moodle server and database to be installed on solid state disk.


title: Chasing infinity with matrix product states by embracing divergences

abstract:
  In this paper, we present a formalism for representing infinite systems in
quantum mechanics by employing a strategy that embraces divergences rather than
avoiding them. We do this by representing physical quantities such as inner
products, expectations, etc., as maps from natural numbers to complex numbers
which contain information about how these quantities diverge, and in particular
whether they scale linearly, quadratically, exponentially, etc. with the size
of the system. We build our formalism on a variant of matrix product states, as
this class of states has a structure that naturally provides a way to obtain
the scaling function. We show that the states in our formalism form a module
over the ring of functions that are made up of sums of exponentials times
polynomials and delta functions. We analyze properties of this formalism and
show how it works for selected systems. Finally, we discuss how our formalism
relates to other work.


title: Shear-induced structures versus flow instabilities

abstract:
  The Taylor-Couette flow of a dilute micellar system known to generate
shear-induced structures is investigated through simultaneous rheometry and
ultrasonic imaging. We show that flow instabilities must be taken into account
since both the Reynolds number and the Weissenberg number may be large. Before
nucleation of shear-induced structures, the flow can be inertially unstable,
but once shear-induced structures are nucleated the kinematics of the flow
become chaotic, in a pattern reminiscent of the inertio-elastic turbulence
known in dilute polymer solutions. We outline a general framework for the
interplay between flow instabilities and flow-induced structures.


title:
A generalized analytic Fourier-Feynman transform on the product function
  space $C_{a,b}^2[0,T]$ and related topics

abstract:
  In this paper we obtain various results involving the generalized analytic
Fourier-Feynman transform and the first variation of functionals in a Fresnel
type class defined on the product function space $C_{a,b}^2[0,T]$.


title:
Topological analysis and Boolean functions. I. Methods and application
  to classical systems

abstract:
  We aim to completely formalize the rough topological analysis of integrable
Hamiltonian systems admitting analytical solutions such that the initial phase
variables along with the time derivatives of the auxiliary variables are
expressed as rational functions (in fact, as polynomials) in some set of
radicals depending on one variable each. We suggest a method to define the
admissible regions in the integral constants space, the segments of oscillation
of the separated variables and the number of connected components of integral
manifolds and critical integral surfaces. This method is based on some
algorithms of processing the tables of some Boolean vector-functions and of
reducing the matrices of linear Boolean vector-functions to some canonical
form. From this point of view we consider here the topologically richest
classical problems of the rigid body dynamics. The article will be continued
with the investigation of some new integrable problems.


title:
EASY-II: a system for modelling of n, d, p, {\gamma} and {\alpha}
  activation and transmutation processes

abstract:
  EASY-II is designed as a functional replacement for the previous European
Activation System, EASY-2010. It has extended nuclear data and new software,
FISPACT-II, written in object-style Fortran to provide new capabilities for
predictions of activation, transmutation, depletion and burnup. The new
FISPACT-II code has allowed us to implement many more features in terms of
energy range, up to GeV; incident particles: alpha, gamma, proton, deuteron and
neutron; and neutron physics: self-shielding effects, temperature dependence,
pathways analysis, sensitivity and error estimation using covariance data.
These capabilities cover most application needs: nuclear fission and fusion,
accelerator physics, isotope production, waste management and many more. In
parallel, the maturity of modern general-purpose libraries such as TENDL-2012
encompassing thousands of target nuclides, the evolution of the ENDF format and
the capabilities of the latest generation of processing codes PREPRO-2012,
NJOY2012 and CALENDF-2010 have allowed the FISPACT-II code to be fed with more
robust, complete and appropriate data: cross-sections with covariance,
probability tables in the resonance ranges, kerma, dpa, gas and radionuclide
production and 24 decay types. All such data for the five most important
incident particles are placed in evaluated data files up to an incident energy
of 200 MeV. The resulting code and data system, EASY-II, includes many new
features and enhancements. It has been extensively tested, and also benefits
from the feedback from wide-ranging validation and verification activities
performed with its predecessor.


title: Models of solar surface dynamics: impact on eigenfrequencies and radius

abstract:
  We study the effects of different descriptions of the solar surface
convection on the eigenfrequencies of p-modes. 1-D evolution calculations of
the whole Sun and 3-D hydrodynamic and magnetohydrodynamic simulations of the
current surface are performed. These calculations rely on realistic physics.
Averaged stratifications of the 3-D simulations are introduced in the 1-D solar
evolution or in the structure models. The eigenfrequencies obtained are
compared to those of 1-D models relying on the usual phenomenologies of
convection and to observations of the MDI instrument aboard SoHO. We also
investigate how the magnetic activity could change the eigenfrequencies and the
solar radius, assuming that, 3 Mm below the surface, the upgoing plasma advects
a 1.2 kG horizontal field.
  All models and observed eigenfrequencies are fairly close below 3 mHz. Above
3 mHz the eigenfrequencies of the phenomenological convection models are above
the observed eigenfrequencies. The frequencies of the models based on the 3-D
simulations are slightly below the observed frequencies. Their maximum
deviation is ~ 3 \mu Hz at 3 mHz but drops below 1 \mu Hz at 4 mHz. Replacing
the hydrodynamic by the magnetohydrodynamic simulation increases the
eigenfrequencies. The shift is negligible below 2.2 mHz and then increases
linearly with frequency to reach ~ 1.7 \mu Hz at 4 mHz. The impact of the
simulated activity is a 14 milliarcsecond shrinking of the solar layers near
the optical depth unity.


title:
Topological analysis and Boolean functions. II. Application to new
  algebraic solutions

abstract:
  This work continues the author's article in Rus. J. Nonlinear Dynamics (2010,
v.6, No.4) and contains applications of the Boolean functions method to
investigation of the admissible regions and the phase topology of three
algebraically solvable systems in the problem of motion of the Kowalevski top
in the double force field.


title:
Scalar Field Cosmologies Hidden Within the Nonlinear Schrodinger
  Equation

abstract:
  The nonlinear, cubic Schrodinger (NLS) equation has numerous physical
applications, but in general is very difficult to solve. Nonetheless, under
certain circumstances parameters quantifying the width, momentum and energy of
the wavefunction evolve under a closed set of ordinary differential equations.
It is shown that for the case of the radial, two dimensional NLS equation, such
evolution equations may be mapped directly onto the cosmological Friedmann
equations for a spatially flat and isotropic universe sourced by a
self-interacting scalar field and a barotropic perfect fluid. Consequently,
analytical techniques that have been developed to study the dynamics of such
cosmological models may be applied to gain insight into aspects of nonlinear
quantum mechanics. In this paper, the Hamilton-Jacobi formalism of the
Friedmann equations, where the scalar field is viewed as the dynamical
variable, is developed within this context. Algorithms for finding exact
solutions are presented and the scaling solutions determined. A form-invariance
of the wavefunction evolution equations is identified. The analysis has direct
applications to anisotropic Bose-Einstein condensation. The Ermakov-Pinney
equation plays a central role in establishing the correspondence between the
quantum-mechanical and gravitational systems.


title:
The Effect of 45{\deg} Grain Boundaries and associated Fe particles on
  Jc and resistivity in Ba(Fe0.9Co0.1)2As2 Thin Films

abstract:
  The anisotropy of the critical current density Jc depends in general on both
the properties of the flux lines (such as line tension, coherence length and
penetration depth) and the properties of the defects (such as density, shape,
orientation etc.). Whereas the Jc anisotropy in microstructurally clean films
can be scaled to an effective magnetic field containing the Ginzburg-Landau
anisotropy term, it is in general not possible (or only in a limited field
range) for samples containing extended defects. Here, the Jc anisotropy of a
Co-doped BaFe2As2 sample with 45{\deg} [001] tilt grain boundaries (GBs), i.e.
grain boundaries created by 45{\deg} in-plane rotated grains, as well as
extended Fe particles is investigated. This microstructure leads to c-axis
correlated pinning, both due to the GBs and the Fe particles and manifests in a
c-axis peak in the Jc anisotropy at low magnetic fields and a deviation from
the anisotropic Ginzburg-Landau scaling at higher fields. Strong pinning at
ellipsoidal extended defects, i.e. the Fe particles, is discussed, and the full
Jc anisotropy is fitted successfully with the vortex path model. The results
are compared to a sample without GBs and Fe particles. 45{\deg} GBs seem to be
good pinning centers rather than detrimental to current flow.


title: Constrained non-collinear magnetism in disordered Fe and Fe-Cr alloys

abstract:
  The development of quantitative models for radiation damage effects in iron,
iron alloys and steels, particularly for the high temperature properties of the
alloys, requires understanding of magnetic interactions, which control the
phase stability of ferritic-martensitic, ferritic, and austenitic steels. In
this work, disordered magnetic configurations of pure iron and Fe-Cr alloys are
investigated using Density Functional Theory (DFT) formalism, in the form of
constrained non-collinear magnetic calculations, with the objective of creating
a database of atomic magnetic moments and forces acting between the atoms. From
a given disordered atomic configuration of either pure Fe or Fe-Cr alloy, a
penalty contribution to the usual spin-polarized DFT total energy has been
calculated by constraining the magnitude and direction of magnetic moments. An
extensive database of non-collinear magnetic moment and force components for
various atomic configurations has been generated and used for interpolating the
spatially-dependent magnetic interaction parameters, for applications in
large-scale spin-lattice dynamics and magnetic Monte-Carlo simulations.


title:
Radiation from a semi-infinite unflanged cylindrical dielectric
  waveguide or optical fiber

abstract:
  Radiative emission from a semi-infinite unflanged circular cylindrical
dielectric waveguide or optical fiber is studied for the case of axisymmetric
modes of TM polarization on the basis of an iterative scheme. The first step of
the scheme leads to approximate values for the reflection coefficients and the
electromagnetic fields inside and outside the waveguide. In a numerical example
the reflection back into the waveguide is appreciable. Correspondingly the
radiation pattern of the outgoing radiation differs appreciably from the lowest
order approximation in which reflection is neglected.


title: Beyond ITER: Neutral beams for DEMO

abstract:
  In the development of magnetically confined fusion as an economically
sustainable power source, ITER is currently under construction. Beyond ITER is
the DEMO programme in which the physics and engineering aspects of a future
fusion power plant will be demonstrated. DEMO will produce net electrical
power. The DEMO programme will be outlined and the role of neutral beams for
heating and current drive will be described. In particular, the importance of
the efficiency of neutral beam systems in terms of injected neutral beam power
compared to wallplug power will be discussed. Options for improving this
efficiency including advanced neutralisers and energy recovery are discussed.


title:
Planck's uncertainty principle and the saturation of Lorentz boosts by
  Planckian black holes

abstract:
  A basic inconsistency arises when the Theory of Special Relativity meets with
quantum phenomena at the Planck scale. Specifically, the Planck length is
Lorentz invariant and should not be affected by a Lorentz boost. We argue that
Planckian relativity must necessarily involve the effect of black hole
formation. Recent proposals for resolving the noted inconsistency seem
unsatisfactory in that they ignore the crucial role of gravity in the
saturation of Lorentz boosts. Furthermore, an invariant length at he Planck
scale amounts to a universal quantum of resolution in the fabric of spacetime.
We argue, therefore, that the universal Planck length requires an extension of
the Uncertainty Principle as well. Thus, the noted inconsistency lies at the
core of Quantum Gravity. In this essay we reflect on a possible resolution of
these outstanding problems.


title:
Analyse des r\^oles dans les communaut\'es virtuelles : d\'efinitions et
  premi\`eres exp\'erimentations sur IMDb

abstract:
  Role analysis in online communities allows us to understand and predict users
behavior. Though several approaches have been followed, there is still lack of
generalization of their methods and their results. In this paper, we discuss
about the ground theory of roles and search for a consistent and computable
definition that allows the automatic detection of roles played by users in
forum threads on the internet. We analyze the web site IMDb to illustrate the
discussion.


title: Value-indefinite observables are almost everywhere

abstract:
  Kochen-Specker theorems assure the breakdown of certain types of
non-contextual hidden variable theories through the non-existence of global,
holistic frame functions; alas they do not allow us to identify where this
breakdown occurs, nor the extent of it. It was recently shown [Phys. Rev. A 86,
062109 (2012)] that this breakdown does not occur everywhere; here we show that
it is maximal in that it occurs almost everywhere, and thus prove that quantum
indeterminacy--often referred to as contextuality or value indefiniteness--is a
global property as is often assumed. In contrast to the Kochen-Specker theorem,
we only assume the weaker non-contextuality condition that any potential value
assignments that may exist are locally non-contextual. Under this assumption,
we prove that once a single arbitrary observable is fixed to occur with
certainty, almost (i.e. with Lebesgue measure one) all remaining observables
are indeterminate.


title:
Optimal control of first-order Hamilton-Jacobi equations with linearly
  bounded Hamiltonian

abstract:
  We consider the optimal control of solutions of first order Hamilton-Jacobi
equations, where the Hamiltonian is convex with linear growth. This models the
problem of steering the propagation of a front by constructing an obstacle. We
prove existence of minimizers to this optimization problem as in a relaxed
setting and characterize the minimizers as weak solutions to a mean field game
type system of coupled partial differential equations. Furthermore, we prove
existence and partial uniqueness of weak solutions to the PDE system. An
interpretation in terms of mean field games is also discussed.
  Keywords: Hamilton-Jacobi equations, optimal control, nonlinear PDE,
viscosity solutions, front propagation, mean field games


title: Photo-generated THz antennas: All-optical control of plasmonic materials

abstract:
  Localized surface plasmon polaritons in conducting structures give rise to
enhancements of electromagnetic local fields and extinction efficiencies.
Resonant conducting structures are conventionally fabricated with a fixed
geometry that determines their plasmonic response. Here, we challenge this
conventional approach by demonstrating the photo-generation of plasmonic
materials (THz plasmonic antennas) on a flat semiconductor layer by the
structured optical illumination through a spatial light modulator. Free charge
carriers are photo-excited only on selected areas, which enables the definition
of different plasmonic antennas on the same sample by simply changing the
illumination pattern, thus without the need of physically structuring the
sample. These results open a wide range of possibilities for an all-optical
spatial and temporal control of resonances on plasmonic surfaces and the
concomitant control of THz extinction and local field enhancements.


title: Status of the Clausius inequality in classical thermodynamics

abstract:
  We present an analysis of the foundations of the well known Clausius
inequality. It is shown that, strictly speaking, the inequality is not a
logical consequence of the Kelvin-Planck formulation of the second law of
thermodynamics. Some thought experiments demonstrating the violation of the
Clausius inequality are considered. Also, a reformulation of the Landauer's
principle in terms of the Clausius inequality is proposed. This version of the
inequality may be considered a consequence of the fluctuation theorem.


title: A Torelli type problem for logarithmic bundles over projective varieties

abstract:
  We investigate the logarithmic bundles associated to arrangements of
hypersurfaces with a fixed degree in a smooth projective variety. We then
specialize to the case when the variety is a quadric hypersurface and a
multiprojective space to prove a Torelli type theorem in some cases.


title: Minimal Weak Basis Textures and Quark Mixing Data

abstract:
  The phenomenology of most general quark mass matrices with minimum of three
texture zeros obtained through weak basis (WB) transformations has been
discussed within the framework of the standard Model (SM). The relationship of
textures, naturalness and weak basis transformations has also been studied.
Adopting a 'hierarchical' parametrization for the quark mass matrix, we have
detailed exact relations for the various elements of the quark mixing matrix
along with the CP asymmetry angle {\beta} illustrating the explicit
relationship between the observed hierarchies among the WB quark mass matrices
and the quark mixing matrix. Besides exploring the complete parameter space
available to the (Mq)11, (q = u, d) elements in these mass matrices, their
implications for quark mixing data and CP violation asymmetries have also been
explored.


title: Pre-conceptual Design Assessment of DEMO Remote Maintenance

abstract:
  EDFA, as part of the Power Plant Physics and Technology programme, has been
working on the pre-conceptual design of a Demonstration Power Plant (DEMO). As
part of this programme, a review of the remote maintenance strategy considered
maintenance solutions compatible with expected environmental conditions, whilst
showing potential for meeting the plant availability targets. A key finding was
that, for practical purposes, the expected radiation levels prohibit the use of
complex remote handling operations to replace the first wall. In 2012/13, these
remote maintenance activities were further extended, providing an insight into
the requirements, constraints and challenges. In particular, the assessment of
blanket and divertor maintenance, in light of the expected radiation conditions
and availability, has elaborated the need for a very different approach from
that of ITER. This activity has produced some very informative virtual reality
simulations of the blanket segments and pipe removal that are exceptionally
valuable in communicating the complexity and scale of the required operations.
Through these simulations, estimates of the maintenance task durations have
been possible demonstrating that a full replacement of the blankets within 6
months could be achieved. The design of the first wall, including the need to
use sacrificial limiters must still be investigated. In support of the
maintenance operations, a first indication of the requirements of an Active
Maintenance Facility (AMF) has been elaborated.


title:
A first-principles investigation of the thermodynamic and mechanical
  properties of Ni-Ti-Sn Heusler and half-Heusler materials

abstract:
  First principles calculations of the vibrational, thermodynamic and
mechanical properties of the Ni-Ti-Sn Heusler and half-Heusler compounds have
been performed. First, we have calculated the Raman and infrared spectra of
NiTiSn, providing benchmark theoretical data directly useful for the
assignments of its experimental spectra and clarifying the debate reported in
the literature on the assignment of its modes. Then, we have discussed the
significant vibrational density-of-states of Ni2TiSn at low-frequencies. These
states are at the origin of (i) its smaller free energy, (ii) its higher
entropy, and (iii) its lower Debye temperature, with respect to NiTiSn.
Finally, we have reported the mechanical properties of the two compounds. In
particular, we have found that the half-Heusler compound has the largest
stiffness. Paradoxically, its bulk modulus is also the smallest. This unusual
behavior has been related to the Ni-vacancies that weaken the structure under
isostatic compression. Both compounds show a ductile behavior.


title:
Infinitely many positive solutions of nonlinear Schr\"{o}dinger
  equations with non-symmetric potentials

abstract:
  We consider the standing-wave problem for a nonlinear Schr\"{o}dinger
equation, corresponding to the semilinear elliptic problem \begin{equation*}
-\Delta u+V(x)u=|u|^{p-1}u,\ u\in H^1(\mathbb{R}^2), \end{equation*} where
$V(x)$ is a uniformly positive potential and $p>1$. Assuming that
\begin{equation*}
V(x)=V_\infty+\frac{a}{|x|^m}+O\Big(\frac{1}{|x|^{m+\sigma}}\Big),\ \text{as}\
|x|\rightarrow+\infty, %\tag{$V2$} \end{equation*} for instance if $p>2$, $m>2$
and $\sigma>1$ we prove the existence of infinitely many positive solutions. If
$V(x)$ is radially symmetric, this result was proved in \cite{WY-10}. The proof
without symmetries is much more difficult, and for that we develop a new {\em
intermediate Lyapunov-Schmidt reduction method}, which is a compromise between
the finite and infinite dimensional versions of it.


title:
A novel Monte Carlo model and simulations of magnetic alloys for nuclear
  applications

abstract:
  We develop a Magnetic Cluster Expansion (MCE) model for binary bcc and fcc
Fe-Cr alloys, as well as for fcc Fe-Ni alloys, and apply it to the
investigation of magnetic properties of these alloys over a broad interval of
concentrations, and over a broad interval of temperatures extending well over
1000 K. We show how an MCE-based Monte Carlo study describes the magnetic
properties of these alloys, for example the composition and microstructure
dependence of the Curie temperature, the non-collinearity of magnetic
structures found in bcc Fe-Cr alloys, phase transitions between bcc and fcc in
Fe-Cr, and the enthalpy of mixing of Fe-Ni alloys. The results of simulations
are in excellent agreement with experimental observations.


title: On the Complexity of Reconstructing Chemical Reaction Networks

abstract:
  The analysis of the structure of chemical reaction networks is crucial for a
better understanding of chemical processes. Such networks are well described as
hypergraphs. However, due to the available methods, analyses regarding network
properties are typically made on standard graphs derived from the full
hypergraph description, e.g.\ on the so-called species and reaction graphs.
However, a reconstruction of the underlying hypergraph from these graphs is not
necessarily unique. In this paper, we address the problem of reconstructing a
hypergraph from its species and reaction graph and show NP-completeness of the
problem in its Boolean formulation. Furthermore we study the problem
empirically on random and real world instances in order to investigate its
computational limits in practice.


title: DEMO Hot Cell and Ex-Vessel Remote Handling

abstract:
  In Europe the work on the specification and design of a Demonstration Power
Plant (DEMO) is being carried out by EFDA in the Power Plant Physics and
Technology (PPP&T) programme. DEMO will take fusion from experimental research
into showing the potential for commercial power generation. This paper
describes the first steps being taken towards the design of the DEMO Hot Cell.
It will show a comparison of the current DEMO in-vessel maintenance concepts
from a Hot Cell perspective, describe a proposed ex-vessel transport system,
and summarize the facilities that have been identified as required within the
Hot Cell, examine current RH technology and discuss the identified critical
development issues.


title:
Computation of Large Deviation Statistics via Iterative
  Measurement-and-Feedback Procedure

abstract:
  We propose a computational method for large deviation statistics of
time-averaged quantities in general Markov processes. In our proposed method,
we repeat a response measurement against external forces, where the forces are
determined by the previous measurement as feedback. Consequently, we obtain a
set of stationary states corresponding to an exponential family of
distributions, each of which shows rare events in the original system as the
typical behavior. As a demonstration of our method, we study large deviation
statistics of one-dimensional lattice gas models.


title:
Subleading processes in production of $W^+ W^-$ pairs in proton-proton
  collisions

abstract:
  We discuss many new subleading processes for inclusive production of $W^+
W^-$ pairs not included in the literature so far. We focus on photon-photon
induced processes. We include elastic-elastic, elastic-inelastic,
inelastic-elastic and inelastic-inelastic contributions. The inelastic photon
distributions in the proton are calculated in two different ways: naive
approach used already in the literature and using photon distributions by
solving special evolution equation with photon being a parton in the proton.
The results strongly depend on the approach used. We calculate also
contributions with resolved photons. The diffractive components have similar
characteristics as the photon-photon elastic-inelastic and inelastic-elastic
mechanisms. The subleading contributions are compared with the well known $q
\bar q$ and $g g$ as well as with double-parton scattering contributions.
Predictions for the total cross section and differential distributions in $W$-
boson rapidity and transverse momentum as well as $WW$ invariant mass are
presented. The $\gamma \gamma$ components constitute only about 1-2 % of the
inclusive $W^+ W^-$ cross section but about 10 % at large $W^{\pm}$ transverse
momenta, and are even comparable to the dominant $q \bar q$ component at large
$M_{WW}$, i.e. are much larger than the often celebrated $g g \to W^+ W^-$
component. Its size is comparable to double parton scattering contribution.
Only elastic-elastic, elastic-inelastic and inelastic-elastic contributions
could be potentially measured to verify our predictions using forward proton
detectors.


title: Poisson varieties from Riemann surfaces

abstract:
  Short survey based on talk at the Poisson 2012 conference. The main aim is to
describe and give some examples of wild character varieties (naturally
generalising the character varieties of Riemann surfaces by allowing more
complicated behaviour at the boundary), their Poisson/symplectic structures
(generalising both the Atiyah-Bott approach and the quasi-Hamiltonian
approach), and the wild mapping class groups.


title:
Solutions for Functional Fully Coupled Forward-Backward Stochastic
  Differential Equations

abstract:
  In this paper, we study a functional fully coupled forward-backward
stochastic differential equations (FBSDEs). Under a new type of integral
Lipschitz and monotonicity conditions, the existence and uniqueness of
solutions for functional fully coupled FBSDEs is proved. We also investigate
the relationship between the solution of functional fully coupled FBSDE and the
classical solution of the path-dependent partial differential equation (P-PDE).
When the solution of the P-PDE has some smooth and regular properties, we solve
the related functional fully coupled FBSDE and prove the P-PDE has a unique
solution.


title: Magnetoacoustic waves in a partially ionized two-fluid plasma

abstract:
  Compressible disturbances propagate in a plasma in the form of
magnetoacoustic waves driven by both gas pressure and magnetic forces. In
partially ionized plasmas the dynamics of ionized and neutral species are
coupled due to ion-neutral collisions. As a consequence, magnetoacoustic waves
propagating through a partially ionized medium are affected by the ion-neutral
coupling. The degree to which the behavior of the classic waves is modified
depends on the physical properties of the various species and on the relative
value of the wave frequency compared to the ion-neutral collision frequency.
Here, we perform a comprehensive theoretical investigation of magnetoacoustic
wave propagation in a partially ionized plasma using the two-fluid formalism.
We consider an extensive range of values for the collision frequency,
ionization ratio, and plasma $\beta$, so that the results are applicable to a
wide variety of astrophysical plasmas. We determine the modification of the
wave frequencies and study the frictional damping due to ion-neutral
collisions. Approximate analytic expressions to the frequencies are given in
the limit case of strongly coupled ions and neutrals, while numerically
obtained dispersion diagrams are provided for arbitrary collision frequencies.
In addition, we discuss the presence of cutoffs in the dispersion diagrams that
constrain wave propagation for certain combinations of parameters. A specific
application to propagation of compressible waves in the solar chromosphere is
given.


title: Multiferroicity in V-doped PbTiO$_{3}$

abstract:
  We report \emph{ab initio} predictions on the proper multiferroic
(ferromagnetic, insulating and ferroelectric) character of PbTiO$_{3}$ doped
with vanadium. V impurities coupled ferromagnetically carry a magnetization of
1 $\mu_{\rm B}$ each. The coupling is expected to be strong, since the
paramagnetic solution is higher by 150 meV/vanadium, and no stable
antiferromagnetic solution was found. The electronic gap in the doped system is
about 0.2-0.3 eV in GGA, hence the system is properly multiferroic. V doping
increases the spontaneous polarization in PbTiO$_{3}$, with an approximate
percentual rate of 0.7 $\mu$C/cm$^{2}$.


title: Decoherence in quantum cosmology and the cosmological constant

abstract:
  We discuss a spacetime having the topology of $S^{3}\times\mathbb{R}$ but
with a different smoothness structure. The initial state of the cosmos in our
model is identified with a wildly embedded 3-sphere (or a fractal space). In
previous work we showed that a wild embedding is obtained by a quantization of
a usual (or tame) embedding. Then a wild embedding can be identified with a
(geometrical) quantum state. During a decoherence process this wild 3-sphere is
changed to a homology 3-sphere. We are able to calculate the decoherence time
for this process. After the formation of the homology 3-sphere, we obtain a
spacetime with an accelerated expansion enforced by a cosmological constant.
The calculation of this cosmological constant gives a qualitative agreement
with the current measured value.


title: All photonic quantum repeaters

abstract:
  Quantum communication holds promise for unconditionally secure transmission
of secret messages and faithful transfer of unknown quantum states. Photons
appear to be the medium of choice for quantum communication. Owing to photon
losses, robust quantum communication over long lossy channels requires quantum
repeaters. It is widely believed that a necessary and highly demanding
requirement for quantum repeaters is the existence of matter quantum memories
at the repeater nodes. Here we show that such a requirement is, in fact,
unnecessary by introducing the concept of all photonic quantum repeaters based
on flying qubits. As an example of the realization of this concept, we present
a protocol based on photonic cluster state machine guns and a loss-tolerant
measurement equipped with local high-speed active feedforwards. We show that,
with such an all photonic quantum repeater, the communication efficiency still
scales polynomially with the channel distance. Our result paves a new route
toward quantum repeaters with efficient single-photon sources rather than
matter quantum memories.


title:
Averaging and spectral properties for the 2D advection-diffusion
  equation in the semi-classical limit for vanishing diffusivity

abstract:
  We consider the two-dimensional advection-diffusion equation on a bounded
domain subject to either Dirichlet or von Neumann boundary conditions and study
both time-independent and time-periodic cases involving Liouville integrable
Hamiltonians that satisfy conditions conducive to applying the averaging
principle. Transformation to action-angle coordinates permits averaging in time
and angle, leading to an underlying eigenvalue equation that allows for
separation of the angle and action coordinates. The result is a one-dimensional
second-order equation involving an anti-symmetric imaginary potential. For
radial flows on a disk or an annulus, we rigorously apply existing
complex-plane WKBJ methods to study the spectral properties in the
semi-classical limit for vanishing diffusivity. In this limit, the spectrum is
found to be a complicated set consisting of lines related to Stokes graphs.
Eigenvalues in the neighborhood of these graphs exhibit nonlinear scaling with
respect to diffusivity leading to convection-enhanced rates of dissipation
(relaxation, mixing) for initial data which are mean-free in the angle
coordinate. These branches coexist with a diffusive branch of eigenvalues that
scale linearly with diffusivity and contain the principal eigenvalue (no
dissipation enhancement).


title: On the efficiency of pseudo-marginal random walk Metropolis algorithms

abstract:
  We examine the behaviour of the pseudo-marginal random walk Metropolis
algorithm, where evaluations of the target density for the accept/reject
probability are estimated rather than computed precisely. Under relatively
general conditions on the target distribution, we obtain limiting formulae for
the acceptance rate and for the expected squared jump distance, as the
dimension of the target approaches infinity, under the assumption that the
noise in the estimate of the log-target is additive and is independent of the
position. For targets with independent and identically distributed components,
we also obtain a limiting diffusion for the first component. We then consider
the overall efficiency of the algorithm, in terms of both speed of mixing and
computational time. Assuming the additive noise is Gaussian and is inversely
proportional to the number of unbiased estimates that are used, we prove that
the algorithm is optimally efficient when the variance of the noise is
approximately 3.283 and the acceptance rate is approximately 7.001%. We also
find that the optimal scaling is insensitive to the noise and that the optimal
variance of the noise is insensitive to the scaling. The theory is illustrated
with a simulation study using the particle marginal random walk Metropolis.


title: Resolvent-Techniques For Multiple Exercise Problems

abstract:
  We study optimal multiple stopping of strong Markov processes with random
refraction periods. The refraction periods are assumed to be exponentially
distributed with a common rate and independent of the underlying dynamics. Our
main tool is using the resolvent operator. In the first part, we reduce
infinite stopping problems to ordinary ones in a general strong Markov setting.
This leads to explicit solutions for wide classes of such problems. Starting
from this result, we analyze problems with finitely many exercise rights and
explain solution methods for some classes of problems with underlying L\'evy
and diffusion processes, where the optimal characteristics of the problems can
be identified more explicitly. We illustrate the main results with explicit
examples.


title: Soft interactions in jet quenching

abstract:
  We study the collisional aspects of jet quenching in a high energy nuclear
collision, especially in the final state pion gas. The jet has a large energy,
and acquires momentum transverse to its axis more effectively by multiple soft
collisions than by few hard scatterings (as known from analogous systems such
as J/\psi production at Hera). Such regime of large E and small momentum
transfer corresponds to Regge kinematics and is characteristically dominated by
the pomeron. From this insight we estimate the jet quenching parameter in the
hadron medium (largely a pion gas) at the end of the collision, which is
naturally small and increases with temperature in line with the gas density.
The physics in the quark-gluon plasma/liquid phase is less obvious, and here we
revisit a couple of simple estimates that suggest indeed that the
pomeron-mediated interactions are very relevant and should be included in
analysis of the jet quenching parameter. Finally, the ocasional hard collisions
produce features characteristic of a L\`evy flight in the q_perp^2 plane
perpendicular to the jet axis. We suggest one- and two-particle q_perp
correlations as interesting experimental probes.


title: Stability of the CMSSM against sfermion VEVs

abstract:
  The recent discovery of a Higgs boson by the LHC experiments has profound
implications for supersymmetric models. In particular, in the context of
restricted models, such as the supergravity-inspired constrained minimal
supersymmetric standard model, one finds that preferred regions in parameter
space have large soft supersymmetry-breaking trilinear couplings. This
potentially gives rise to charge- and/or color-breaking minima besides those
with the correct breaking of $SU(2)_L \times U(1)_Y$. We investigate the
stability of parameter points in this model against tunneling to possible
deeper color- and/or charge-breaking minima of the one-loop effective
potential. We find that allowed regions of the parameter space with light staus
or with light stops are seriously constrained by the requirement that the
tunneling time out of the normal electroweak-symmetry-breaking vacuum is more
than a fifth of the age of the known Universe. We also find that "thumb rule"
conditions on Lagrangian parameters based on specific directions in the
tree-level potential are of limited use.


title:
Properties of unique hard X-ray dips observed from GRS 1915+105 and IGR
  J17091-3624 and their implications

abstract:
  We report a comprehensive study on spectral and timing properties of hard
X-ray dips uniquely observed in some so-called variability classes of the
micro-quasars GRS 1915+105 and IGR J17091-3624. These dips are characterized by
a sudden decline in the 2.0-60.0 keV X-ray intensity by a factor of 4-12
simultaneous with the increase in hardness ratio by a factor of 2-4. Using 31
observations of GRS 1915+105 with RXTE/PCA, we show that different behavior are
observed in different types of variability classes, and we find that a
dichotomy is observed between classes with abrupt transitions vs those with
smoother evolution. For example, both energy-lag spectra and frequency-lag
spectra of hard X-ray dips in classes with abrupt transitions and shorter dip
intervals show hard-lag (hard photons lag soft photons), while both lag spectra
during hard dips in classes with smoother evolution and longer dip intervals
show soft-lag. Both lag time-scales are of the order of 100-600 msec. We also
show that timing and spectral properties of hard X-ray dips observed in light
curves of IGR J17091-3624 during its 2011 outburst are consistent with the
properties of the abrupt transitions in GRS 1915+105 rather than smooth
evolution. A global correlation between the X-ray intensity cycle time and hard
dip time is observed for both abrupt and smooth transition which may be due to
two distinct physical processes whose time-scales are eventually correlated. We
discuss implications of our results in the light of some generic models.


title: Shutdown Margin for High Conversion BWRs Operating in Th-233U Fuel Cycle

abstract:
  Several reactivity control system design options are explored in order to
satisfy shutdown margin (SDM) requirements in a high conversion BWRs operating
in Th-233U fuel cycle (Th-RBWR). The studied has an axially heterogeneous fuel
assembly structure with a single fissile zone sandwiched between two fertile
blanket zones. The utilization of an originally suggested RBWR Y-shape control
rod in Th-RBWR is shown to be insufficient for maintaining adequate SDM to
balance the high negative reactivity feedbacks, while maintaining fuel breeding
potential, core power rating, and minimum Critical Power Ratio (CPR). Instead,
an alternative assembly design, also relying on heterogeneous fuel zoning, is
proposed for achieving fissile inventory ratio (FIR) above unity, adequate SDM
and meeting minimum CPR limit at thermal core output matching the ABWR power.
The new concept was modeled as a single 3-dimensional fuel assembly having
reflective radial boundaries, using the BGCore system, which consists of the
MCNP code coupled with fuel depletion and thermo-hydraulic feedback modules.


title: Fourier-Mukai functors and perfect complexes on dual numbers

abstract:
  We show that every exact fully faithful functor from the category of perfect
complexes on the spectrum of dual numbers to the bounded derived category of a
noetherian separated scheme is of Fourier-Mukai type. The kernel turns out to
be an object of the bounded derived category of coherent complexes on the
product of the two schemes. We also study the space of stability conditions on
the derived category of the spectrum of dual numbers.


title: Morphology and magnetic properties of Fe3O4-alginic acid nanocomposites

abstract:
  Morphology, structure and magnetic properties of nanocomposites of magnetite
(Fe3O4) nanoparticles and alginic acid (AA) are studied. Magnetite Fe3O4
nanoparticles and the nanoparticles capped with alginic acid exhibit very
distinct properties. The chemical bonding between alginic acid and surface of
magnetite nanoparticles results in recovery of surface magnetization. On the
other hand, it also leads to enhanced surface spin disorder and unconventional
behavior of magnetization observed in Fe3O4-AA nanocomposites at low
temperatures.


title: Infinite energy solutions to inelastic homogeneous Boltzmann equation

abstract:
  This paper is concerned with the existence, shape and dynamical stability of
infinite-energy equilibria for a general class of spatially homogeneous kinetic
equations in space dimensions $d \geq 3$. Our results cover in particular
Bobyl\"ev's model for inelastic Maxwell molecules. First, we show under certain
conditions on the collision kernel, that there exists an index $\alpha\in(0,2)$
such that the equation possesses a nontrivial stationary solution, which is a
scale mixture of radially symmetric $\alpha$-stable laws. We also characterize
the mixing distribution as the fixed point of a smoothing transformation.
Second, we prove that any transient solution that emerges from the NDA of some
(not necessarily radial symmetric) $\alpha$-stable distribution converges to an
equilibrium. The key element of the convergence proof is an application of the
central limit theorem to a representation of the transient solution as a
weighted sum of i.i.d. random vectors.


title: Bounds on sup-norms of half-integral weight modular forms

abstract:
  Bounding sup-norms of modular forms in terms of the level has been the focus
of much recent study. In this work the sup norm of a half integral weight cusp
form is bounded in terms of the level.


title: Fractional energy states of strongly-interacting bosons in one dimension

abstract:
  We study two-component bosonic systems with strong inter-species and
vanishing intra-species interactions. A new class of exact eigenstates is found
with energies that are {\it not} sums of the single-particle energies with wave
functions that have the characteristic feature that they vanish over extended
regions of coordinate space. This is demonstrated in an analytically solvable
model for three equal mass particles, two of which are identical bosons, which
is exact in the strongly-interacting limit. We numerically verify our results
by presenting the first application of the stochastic variational method to
this kind of system. We also demonstrate that the limit where both inter- and
intra-component interactions become strong must be treated with extreme care as
these limits do not commute. Moreover, we argue that such states are generic
also for general multi-component systems with more than three particles. The
states can be probed using the same techniques that have recently been used for
fermionic few-body systems in quasi-1D.

categories: cond-mat.quant-gas math-ph math.MP quant-ph


title: Degree of Regularity of Linear Homogeneous Equations

abstract:
  We define a linear homogeneous equation to be strongly r-regular if, when a
finite number of inequalities is added to the equation, the system of the
equation and inequalities is still r-regular. In this paper, we show that, if a
linear homogeneous equation is r-regular, then it is strongly r-regular. In
2009, Alexeev and Tsimerman introduced a family of equations, each of which is
(n-1)-regular but not n-regular, verifying a conjecture of Rado from 1933.
These equations are actually strongly (n-1)-regular as an immediate corollary
of our results.


title:
Maximal tripartite entanglement between singlet-triplet qubits in
  quantum dots

abstract:
  Singlet-triplet states in double quantum dots are promising realizations of
qubits, and capacitive coupling can be used to create entanglement between
these qubits. We propose an entangling three-qubit gate of singlet-triplet
qubits in a triangular setup. Our simulations using a realistic microscopic
model show that a maximally entangled Greenberger-Horne-Zeilinger state can be
generated as the qubits are evolved under exchange. Furthermore, our analysis
for the gate operation can be used to extract the actual experimental pulse
sequence needed to realize this.


title: Continuous compliance: a proxy-based monitoring framework

abstract:
  Within the Own Risk and Solvency Assessment framework, the Solvency II
directive introduces the need for insurance undertakings to have efficient
tools enabling the companies to assess the continuous compliance with
regulatory solvency requirements. Because of the great operational complexity
resulting from each complete evaluation of the Solvency Ratio, this monitoring
is often complicated to implement in practice. This issue is particularly
important for life insurance companies due to the high complexity to project
life insurance liabilities. It appears relevant in such a context to use
parametric tools, such as Curve Fitting and Least Squares Monte Carlo in order
to estimate, on a regular basis, the impact on the economic own funds and on
the regulatory capital of the company of any change over time of its underlying
risk factors. In this article, we first outline the principles of the
continuous compliance requirement then we propose and implement a possible
monitoring tool enabling to approximate the eligible elements and the
regulatory capital over time. In a final section we compare the use of the
Curve Fitting and the Least Squares Monte Carlo methodologies in a standard
empirical finite sample framework, and stress adapted advices for future
proxies users.


title: SARAH 4: A tool for (not only SUSY) model builders

abstract:
  We present the new version of the Mathematica package SARAH which provides
the same features for a non-supersymmetric model as previous versions for
supersymmetric models. This includes an easy and straightforward definition of
the model, the calculation of all vertices, mass matrices, tadpole equations,
and self-energies. Also the two-loop renormalization group equations for a
general gauge theory are now included and have been validated with the
independent Python code PyR@te. Model files for FeynArts, CalcHep/CompHep,
WHIZARD and in the UFO format can be written, and source code for SPheno for
the calculation of the mass spectrum, a set of precision observables, and the
decay widths and branching ratios of all states can be generated. Furthermore,
the new version includes routines to output model files for Vevacious for both,
supersymmetric and non-supersymmetric, models. Global symmetries are also
supported with this version and by linking Susyno the handling of Lie groups
has been improved and extended.


title:
Site-disorder driven superconductor-insulator transition: A dynamical
  mean field study

abstract:
  We investigate the effect of site-disorder on the superconducting (SC) state
in the attractive Hubbard model within the framework of dynamical mean field
theory. For a fixed interaction strength ($U$), the SC order parameter (OP)
decreases monotonically with increasing disorder ($x$), while the
single-particle spectral gap (SG) decreases for small $x$, reaches a minimum
and keeps increasing for larger $x$. Thus, the system remains gapped beyond the
destruction of the superconducting state, indicating a disorder-driven
superconductor-insulator transition. We investigate this transition in depth
considering the effects of weak and strong disorder for a range of interaction
strengths. In the clean case, the order-parameter is known to increase
monotonically with increasing interaction, saturating at a finite value
asymptotically for $U\rightarrow \infty$. The presence of disorder results in
destruction of superconductivity at large $U$, thus drastically modifying the
clean case behaviour. A physical understanding of our findings is obtained by
invoking particle-hole asymmetry and the probability distributions of the order
parameter and spectral gap.


title: Enumeration of PLCP-orientations of the 4-cube

abstract:
  The linear complementarity problem (LCP) provides a unified approach to many
problems such as linear programs, convex quadratic programs, and bimatrix
games. The general LCP is known to be NP-hard, but there are some promising
results that suggest the possibility that the LCP with a P-matrix (PLCP) may be
polynomial-time solvable. However, no polynomial-time algorithm for the PLCP
has been found yet and the computational complexity of the PLCP remains open.
Simple principal pivoting (SPP) algorithms, also known as Bard-type algorithms,
are candidates for polynomial-time algorithms for the PLCP. In 1978, Stickney
and Watson interpreted SPP algorithms as a family of algorithms that seek the
sink of unique-sink orientations of $n$-cubes. They performed the enumeration
of the arising orientations of the $3$-cube, hereafter called
PLCP-orientations. In this paper, we present the enumeration of
PLCP-orientations of the $4$-cube.The enumeration is done via construction of
oriented matroids generalizing P-matrices and realizability classification of
oriented matroids.Some insights obtained in the computational experiments are
presented as well.


title: Efficient Computation of Invariant Tori in Volume-Preserving Maps

abstract:
  In this paper we implement a numerical algorithm to compute codimension-one
tori in three-dimensional, volume-preserving maps. A torus is defined by its
conjugacy to rigid rotation, which is in turn given by its Fourier series. The
algorithm employs a quasi-Newton scheme to find the Fourier coefficients of a
truncation of the series. This technique is based upon the theory developed in
the accompanying article by Blass and de la Llave. It is guaranteed to converge
assuming the torus exists, the initial estimate is suitably close, and the map
satisfies certain nondegeneracy conditions. We demonstrate that the growth of
the largest singular value of the derivative of the conjugacy predicts the
threshold for the destruction of the torus. We use these singular values to
examine the mechanics of the breakup of the tori, making comparisons to
Aubry-Mather and anti-integrability theory when possible.


title: Linear Stability of the boundary layer under a solitary wave

abstract:
  A theoretical and numerical analysis of the linear stability of the boundary
layer flow under a solitary wave is presented. In the present work, the
nonlinear boundary layer equations are solved. The result is compared to the
linear boundary layer solution in Liu et al. (2007) reveal- ing that both
profiles are disagreeing more than has been found before. A change of frame of
reference has been used to allow for a classical linear stability analysis
without the need to redefine the notion of stability for this otherwise
unsteady flow. For the linear stability the Orr-Sommerfeld equation and the
parabolic stability equation were used. The results are compared to key results
of inviscid stability theory and validated by means of a direct numerical
simulation using a Legendre-Galerkin spectral ele- ment Navier-Stokes solver.
Special care has been taken to ensure that the numerical results are valid.
Linear stability predicts that the boundary layer flow is unstable for the
entire parameter range considered, confirm- ing qualitatively the results by
Blondeaux et al. (2012). As a result of this analysis the stability of this
flow cannot be described by a critical Reynolds number unlike what is atempted
in previous publications. This apparent contradiction can be resolved by
looking at the amplification factor responsible for the amplification of the
perturbation. For lower Reynolds numbers, the boundary layer flow becomes
unstable in the de- celeration region of the flow. For higher Reynolds numbers,
instability arises also in the acceleration region of the flow, confirming,
albeit only qualitatively, an observation in the experiments by Sumer et al.
(2010).


title: Total domination multisubdivision number of a graph

abstract:
  The domination multisubdivision number of a nonempty graph $G$ was defined as
the minimum positive integer $k$ such that there exists an edge which must be
subdivided $k$ times to increase the domination number of $G$. Similarly we
define the total domination multisubdivision number msd$_{\gamma_t}(G)$ of a
graph $G$ and we show that for any connected graph $G$ of order at least two,
msd$_{\gamma_t}(G)\leq 3.$ We show that for trees the total domination
multisubdivision number is equal to the known total domination subdivision
number. We also determine the total domination multisubdivision number for some
classes of graphs and characterize trees $T$ with msd$_{\gamma_t}(T)=1$.


title: Extremal divisors on moduli spaces of rational curves with marked points

abstract:
  We study effective divisors on $\overline{M}_{0,n}$, focusing on hypertree
divisors introduced by Castravet and Tevelev and the proper transforms of
divisors on $\overline{M}_{1,n-2}$ introduced by Chen and Coskun. Results
include a database of hypertree divisor classes and closed formulas for
Chen--Coskun divisor classes. We relate these two types of divisors, and from
this construct extremal divisors on $\overline{M}_{0,n}$ for $n \geq 7$ that
furnish counterexamples to the conjectural description of the effective cone of
$\overline{M}_{0,n}$ given by Castravet and Tevelev.


title:
Monotonicity and nonexistence results for some fractional elliptic
  problems in the half space

abstract:
  We study a class of fractional elliptic problems of the form $\Ds u= f(u)$ in
the half space $\R^N_+:=\{x \in \R^N\::\: x_1>0\}$ with the complementary
Dirichlet condition $u \equiv 0$ in $\R^N \setminus \R^N_+$. Under mild
assumptions on the nonlinearity $f$, we show that bounded positive solutions
are increasing in $x_1$. For the special case $f(u)=u^q$, we deduce
nonexistence of positive bounded solutions in the case where $q \ge 1$ and
$q<\frac{N-1+2s}{N-1-2s}$ if $N \ge 1+2s$. We do not require integrability
assumptions on the solutions we study.


title: On Nonrelativistic Diffeomorphism Invariance

abstract:
  We study certain aspects of the recently proposed notion of nonrelativistic
diffeomorphism invariance. In particular, we consider specific examples of
invariant actions, extended gauge symmetry as well as an application to the
theory of quantum Hall effect. We also discuss an alternative approach based on
Horava-Lifshitz gravity.


title: Generalized geometric structures on complex and symplectic manifolds

abstract:
  On a smooth manifold M, generalized complex (generalized paracomplex)
structures provide a notion of interpolation between complex (paracomplex) and
symplectic structures on M.
  Given a complex manifold (M,j), we define six families of distinguished
generalized complex or paracomplex structures on M. Each one of them
interpolates between two geometric structures on M compatible with j, for
instance, between totally real foliations and Kahler structures, or between
hypercomplex and C-symplectic structures. These structures on M are sections of
fiber bundles over M with typical fiber G/H for some Lie groups G and H. We
determine G and H in each case.
  We proceed similarly for symplectic manifolds. We define six families of
generalized structures on (M,omega), each of them interpolating between two
structures compatible with omega, for instance, between a C-symplectic and a
para-Kahler structure (aka bi-Lagrangian foliation).


title: Multilayer Networks

abstract:
  In most natural and engineered systems, a set of entities interact with each
other in complicated patterns that can encompass multiple types of
relationships, change in time, and include other types of complications. Such
systems include multiple subsystems and layers of connectivity, and it is
important to take such "multilayer" features into account to try to improve our
understanding of complex systems. Consequently, it is necessary to generalize
"traditional" network theory by developing (and validating) a framework and
associated tools to study multilayer systems in a comprehensive fashion. The
origins of such efforts date back several decades and arose in multiple
disciplines, and now the study of multilayer networks has become one of the
most important directions in network science. In this paper, we discuss the
history of multilayer networks (and related concepts) and review the exploding
body of work on such networks. To unify the disparate terminology in the large
body of recent work, we discuss a general framework for multilayer networks,
construct a dictionary of terminology to relate the numerous existing concepts
to each other, and provide a thorough discussion that compares, contrasts, and
translates between related notions such as multilayer networks, multiplex
networks, interdependent networks, networks of networks, and many others. We
also survey and discuss existing data sets that can be represented as
multilayer networks. We review attempts to generalize single-layer-network
diagnostics to multilayer networks. We also discuss the rapidly expanding
research on multilayer-network models and notions like community structure,
connected components, tensor decompositions, and various types of dynamical
processes on multilayer networks. We conclude with a summary and an outlook.


title: Maximizing Spectral Flux from Self-Seeding Hard X-ray FELs

abstract:
  Fully coherent x-rays can be generated by self-seeding x-ray free-electron
lasers (XFELs). Self-seeding by a forward Bragg diffraction (FBD) monochromator
has been recently proposed [1] and demonstrated [2]. Characteristic time To of
FBD determines the power, spectral, and time characteristics of the FBD seed
[3]. Here we show that for a given electron bunch with duration sigma_e the
spectral flux of the self-seeding XFEL can be maximized, and the spectral
bandwidth can be respectively minimized by choosing To ~ sigma_e/pi and by
optimizing the electron bunch delay tau_e. The choices of To and tau_e are not
unique. In all cases, the maximum value of the spectral flux and the minimum
bandwidth are primarily determined by sigma_e. Two-color seeding takes place To
>> sigma_e/\pi. The studies are performed, for a Gaussian electron bunch
distribution with the parameters, close to those used in the short-bunch
(sigma_e ~ 5 fs) and long-bunch (sigma_e ~ 20 fs) operation modes of the LCLS
XFEL.


title:
A "Continuous" Limit of the Complementary Bannai-Ito Polynomials:
  Chihara Polynomials

abstract:
  A novel family of $-1$ orthogonal polynomials called the Chihara polynomials
is characterized. The polynomials are obtained from a "continuous" limit of the
complementary Bannai-Ito polynomials, which are the kernel partners of the
Bannai-Ito polynomials. The three-term recurrence relation and the explicit
expression in terms of Gauss hypergeometric functions are obtained through a
limit process. A one-parameter family of second-order differential Dunkl
operators having these polynomials as eigenfunctions is also exhibited. The
quadratic algebra with involution encoding this bispectrality is obtained. The
orthogonality measure is derived in two different ways: by using Chihara's
method for kernel polynomials and, by obtaining the symmetry factor for the
one-parameter family of Dunkl operators. It is shown that the polynomials are
related to the big $-1$ Jacobi polynomials by a Christoffel transformation and
that they can be obtained from the big $q$-Jacobi by a $q\rightarrow -1$ limit.
The generalized Gegenbauer/Hermite polynomials are respectively seen to be
special/limiting cases of the Chihara polynomials. A one-parameter extension of
the generalized Hermite polynomials is proposed.


title: The Farrell-Jones conjecture for S-arithmetic groups

abstract:
  This paper contains the results of my PhD-thesis. I will show the K- and
L-theoretic Farrell-Jones conjecture (FJC) for the general linear groups over
the rationals and over the rational functions over a finite field. This
especially implies the conjecture for all S-arithmetic groups.


title: Torsion subschemes and the Tate-Voloch conjecture over p-adic fields

abstract:
  We give a new proof of the Tate-Voloch conjecture, in the situation where the
ambient variety is a semiabelian variety defined over Qp. Our proof is new in
the sense that it avoids any reference to algebraic model theory or p-adic
Hodge theory.


title:
Analemmatic and Horizontal Sundials of the Bronze Age (Northern Black
  Sea Coast)

abstract:
  The paper presents the results of a study of unique plate with images of
Srubna burial of tumuli group Popov Yar-2 (Ukraine) and plate of Srubna burial
of tumulus field Tavriya-1 (Russia). A distinctive feature of the images is the
orderliness and symmetry of the composition, as well as the location of
elliptical cupped depressions. With the help of mathematical and astronomical
methods we prove in this paper that the plates with the images are the ancient
sundials. At the Popov Yar-2 plate located two sundials, which worked at the
same time: the analemmatic sundial and the horizontal sundial with two gnomons
and the linear scale. At the Tavriya-1 plate located analemmatic sundial. On
the basis of the reconstruction of the linear parameters of the gnomon of both
Popov Yar-2 plate sundials and given the scale value of horizontal sundial, in
the article that the potential indirect impact protoscientific knowledge of
ancient Egypt to the Srubna population in the Northern Black Sea coast.
  Srubna burial, plate, wells, cupped depressions, analemmatic, horizontal
sundial, gnomon, archaeoastronomy, archeology


title:
A trace formula approach to control theorems for overconvergent
  automorphic forms

abstract:
  We present an approach to proving control theorems for overconvergent
automorphic forms on some Harris-Taylor unitary Shimura varieties based on a
comparison between the rigid coho- mology of the multiplicative ordinary locus
and the rigid cohomology of the overlying Igusa tower, the latter which may be
computed using the Harris-Taylor version of the Langlands-Kottwitz method. We
also prove a higher level version, generalizing work of Coleman.


title:
On the vanishing of cohomologies of $p$-adic Galois representations
  associated with elliptic curves

abstract:
  Let $K$ be a $p$-adic field and $E$ an elliptic curve over $K$ with potential
good reduction. For some large Galois extensions $L$ of $K$ containing all
$p$-power roots of unity, we show the vanishing of certain Galois cohomology
groups of $L$ with values in the $p$-adic representation associated with $E$.
This generalizes some results of Coates, Sujatha and Wintenberger.


title: Truncation and the induction theorem

abstract:
  A key result in a 2004 paper by S. Arkhipov, R. Bezrukavnikov, and V.
Ginzburg (ABG) gives an equivalence of the bounded derived category of finite
dimensional modules for the principal block of a Lusztig quantum algebra at an
$\ell^{th}$ root of unity, with am explicit full subcategory of the bounded
derived category of integrable type 1 modules for a Borel part of the quantum
algebra. Some restrictions on $\ell$ are required; in particular, it is assumed
$\ell > h$, the Coxeter number. The same paper suggests there is an analogous
result for representations of semisimple algebraic groups in characteristic
$p>0$, and the authors of this paper have proved such a result (with $p>h$) in
a separate manuscript, recently posted. The philosophy of the proof is a
variation on that of ABG, but contains new ingredients and some missing
details, even in the quantum case. The present paper continues the study of the
modular case, showing the equivalence constructed (via a right derived functor
of induction from a Borel part) behaves well, when $p>2h-2$, with respect to
certain weight poset "truncations", making use of van der Kallen's 1989
"excellent order" highest weight categories. This implies, in particular, that
the equivalence can be reformulated in terms of triangulated categories
associated to derived categories of finite dimensional quasi-hereditary
algebras. We expect that a similar result holds in the quantum case.


title:
Method for the Analysis of Forward-Backward Multiplicity Correlations in
  Heavy-Ion Collisions

abstract:
  In heavy-ion ({\it A-A}) collisions, the correlations among the particles
produced across wide range in rapidity, probe the early stages of the reaction.
The analyses of forward-backward multiplicity correlations in these collisions
are complicated by several effects, which are absent or minimized in
hadron-hadron collisions. This includes effects, such as the centrality
selection in the {\it A-A} collisions, which interfere with the measurement of
the dynamical correlations. A method, which takes into account the fluctuations
in centrality selection, has been utilized to determine the forward-backward
correlation strength {$b_{\rm corr}$} in {\itA-A} collisions. This method has
been validated by using the HIJING event generator in case of Au-Au collisions
at $\sqrt{s_{NN}}$= 200 GeV and Pb-Pb collisions at $\sqrt{s_{NN}}$= 2.76 TeV.
It is shown that the effect of impact parameter fluctuations is to be
considered properly in order to obtain meaningful results.


title:
Structural, electrical and magnetic properties of magnetoelectric GdMnO3
  thin films prepared by sol-gel method

abstract:
  In this work, we analysed GdMnO3 magnetoelectric thin films prepared by a
general sol-gel method. The film formation temperature is analysed by
termogravimetric analysis, while the lattice parameters of the Pbnm
orthorhombic films are determined from the analysis of the x-ray spectra. The
x-ray results also reveal that GdMnO3 films are under compression along the b
axis. The lattice dynamic analysis carried out by Raman spectroscopy confirms
the formation of films with a Pbnm orthorhombic structure. Moreover, the
analysis of the Raman spectra suggests that besides film-substrate interaction,
texture and grain size influence can alters lattice dynamics relative to bulk
ones. Magnetic measurements shows that the films response is different of the
observed in ceramic and single crystal; mainly, in the shape and temperature
where the transitions taking place. The magnetic study also reveals that GdMnO3
films are paramagnetic above 80 K, showing a ferromagnetic response at low
temperatures (T=<15 K). The dielectric analysis carried out in the 850C
annealed films shows the formation of a relaxation process at low temperature,
which is associated with a polaronic process. Moreover, it is also observed a
small anomaly at T~27 K that might be related with the magnetic transition
taking place in this temperature range.


title: Geometric structure of percolation clusters

abstract:
  We investigate the geometric properties of percolation clusters, by studying
square-lattice bond percolation on the torus. We show that the density of
bridges and nonbridges both tend to 1/4 for large system sizes. Using Monte
Carlo simulations, we study the probability that a given edge is not a bridge
but has both its loop arcs in the same loop, and find that it is governed by
the two-arm exponent. We then classify bridges into two types: branches and
junctions. A bridge is a {\em branch} iff at least one of the two clusters
produced by its deletion is a tree. Starting from a percolation configuration
and deleting the branches results in a {\em leaf-free} configuration, while
deleting all bridges produces a bridge-free configuration. Although branches
account for $\approx 43%$ of all occupied bonds, we find that the fractal
dimensions of the cluster size and hull length of leaf-free configurations are
consistent with those for standard percolation configurations. By contrast, we
find that the fractal dimensions of the cluster size and hull length of
bridge-free configurations are respectively given by the backbone and external
perimeter dimensions. We estimate the backbone fractal dimension to be
$1.643\,36(10)$.


title: Higher-order superintegrability of a Holt related potential

abstract:
  In a recent paper, Post and Winternitz studied the properties of
two-dimensional Euclidean potentials that are linear in one of the two
Cartesian variables. In particular, they proved the existence of a potential
endowed with an integral of third-order and an integral of fourth-order. In
this paper we show that these results can be obtained in a more simple and
direct way by noting that this potential is directly related with the Holt
potential. It is proved that the existence of a potential with higher order
superintegrability is a direct consequence of the integrability of the family
of Holt type potentials.


title:
Lattice stability and formation energies of intrinsic defects in Mg2Si
  and Mg2Ge via first principles simulations

abstract:
  We report an ab initio study of the semiconducting Mg2X (with X = Si, Ge)
compounds and in particular we analyze the formation energy of the different
point defects with the aim to understand the intrinsic doping mechanisms. We
find that the formation energy of Mg2Ge is 50 % larger than the one of Mg2Si,
in agreement with the experimental tendency. From the study of the stability
and the electronic properties of the most stable defects taking into account
the growth conditions, we show that the main reason for the n-doping in these
materials comes from interstitial magnesium defects. Conversely, since other
defects acting like acceptors such as Mg vacancies or multivacancies are more
stable in Mg2Ge than in Mg2Si, this explains why Mg2Ge can be of n or p type,
contrary to Mg2Si. The finding that the most stable defects are different in
Mg2Si and Mg2Ge and depend on the growth conditions is important and must be
taken into account in the search of the optimal doping to improve the
thermoelectric properties of these materials.


title: On Generalized Integrals and Ramanujan-Jacobi Special Functions

abstract:
  In this article we consider new generalized functions for evaluating
integrals and roots of functions. The construction of these generalized
functions is based on Rogers-Ramanujan continued fraction, the
Ramanujan-Dedekind eta, the elliptic singular modulus and other similar
functions. We also provide modular equations of these new generalized functions
and remark some interesting properties.


title: The equations of CCC

abstract:
  I review the equations of Conformal Cyclic Cosmology given by Penrose. I
suggest a slight modification to Penrose's prescription and show how this works
out for FRW cosmologies and for Class A Bianchi cosmologies.


title:
A- and B-type star pulsations in the Kepler and CoRoT era: theoretical
  considerations

abstract:
  Among A-type main-sequence variables, pulsations of $\delta$ Sct and $\gamma$
Dor variables are driven in the He II ionization zone, while H-ionization zone
and strong magnetic fields seem to play roles in the excitation of high-order
p-modes in rapidly oscillating Ap (roAp) stars. Pulsations in B-type variables,
$\beta$ Cephei and slowly pulsating B (SPB) stars are excited by the
$\kappa$-mechanism at the Fe-opacity bump at $T\approx 2\times10^5$K. In
addition, the strange-mode instability seems responsible for the excitation of
pulsations in luminous AB-supergiants ($\alpha$ Cygni variables). We discuss
excitation mechanisms for pulsations in A- and B-type variables stars.


title:
Rotational properties of the O-type star population in the Tarantula
  region

abstract:
  The 30 Doradus (30\,Dor) region in the Large Magellanic Cloud (also known as
the Tarantula Nebula) is the nearest massive starburst region, containing the
richest sample of massive stars in the Local Group. It is the best possible
laboratory to investigate aspects of the formation and evolution of massive
stars. Here, we focus on rotation which is a key parameter in the evolution of
these objects. We establish the projected rotational velocity, $v_{e}\sin i$,
distribution of an unprecedented sample of 216 radial velocity constant
($\rm{\Delta RV\, \leq\, 20 \,km s^{-1}}$) O-type stars in 30\,Dor observed in
the framework of the VLT-FLAMES Tarantula Survey (VFTS). The distribution of
$v_{e}\sin i$ shows a two-component structure: a peak around 80 $\rm{km
s^{-1}}$ and a high-velocity tail extending up to $\sim$600 $\rm{km s^{-1}}$.
Around 75% of the sample has 0 $\leq\, v_{e}\sin i \leq$ 200 $\rm{km s^{-1}}$
with the other 25% distributed in the high-velocity tail. The presence of the
low-velocity peak is consistent with that found in other studies of late-O and
early-B stars. The high-velocity tail is compatible with expectations from
binary interaction synthesis models and may be predominantly populated by
post-binary interaction, spun-up, objects and mergers. This may have important
implications for the nature of progenitors of long-duration gamma ray bursts.


title: Pulsation of magnetic stars

abstract:
  Some Ap stars with strong magnetic fields pulsate in high order p-modes; they
are called roAp (rapidly oscillating Ap) stars. The p-mode frequencies are
modified by the magnetic fields. Although the large frequency separations are
hardly affected, small separations are modified considerably. The magnetic
field also affects the latitudinal amplitude distribution on the surface. We
discuss the property of axisymmetric p-mode oscillations in roAp stars.


title: The concordance classification of low crossing number knots

abstract:
  We present the complete classification of the subgroup of the classical knot
concordance group generated by knots with eight or fewer crossings. Proofs are
presented in summary. We also describe extensions of this work to the case of
nine crossing knots.


title:
N=4 mechanics with diverse (4,4,0) multiplets: explicit examples of HKT,
  CKT, and OKT geometries

abstract:
  We present simple models of N=4 supersymmetric mechanics with ordinary and
mirror linear (4,4,0) multiplets that give a transparent description of HKT,
CKT, and OKT geometries. These models are treated in the N=4 and N=2 superfield
approaches, as well as in the component approach. Our study makes manifest that
the CKT and OKT supersymmetric sigma models are distinguished from the more
simple HKT models by the presence of extra holomorphic torsions in the
supercharges.


title: Phonons correlation with magnetic excitations in weak ferromagnet YCrO3

abstract:
  We report on the temperature dependent Raman spectroscopic studies of
orthorombic distorted perovskite YCrO3 in the temperature range of 20-300K.
Temperature dependence of DC-magnetization measurement under field cooled and
zero field cooled modes confirmed the transition temperature (TN ~142K) and
anomalous characteristic temperature (T* ~60K), above which magnetization tends
to saturate. Magnetization isotherm recorded below TN at 125K shows clear loop
opening without magnetization saturation up to 20kOe, indicating the
coexistence of antiferromagnetic (AFM) interaction with weak ferromagnetic
(WFM) phase. Mean field calculation for exchange constants further confirms the
complex magnetic phase below TN. Temperature evolution of lineshape parameters
of selected modes (associated with the octahedral rotation and A-shift in the
unit cell) revealed anomalous phonon shift near Cr3+ magnetic ordering
temperature (TN ~142K). Additional phonon anomaly was identified at T* ~60K in
agreement with the magnetization results and reflects the change in spin
dynamics, plausibly due to the change in Cr-spin configuration. Moreover, the
positive and negative shift in Raman frequency below TN revel the existence of
competing WFM and AFM exchanges. The phonon shift of B3g (3)-octahedral
rotation mode fairly scaled with the square of sublattice magnetization from TN
to T*, below which it start to depart from theconventional behaviour and need
further attention. This correlation between magnetic and Raman data elucidate
the spin-phonon coupling owing to the multiferroic phenomenon in YCrO3.


title:
Phase behavior and mesoscale solubilization in aqueous solutions of
  hydrotropes

abstract:
  Hydrotropes are amphiphilic molecules that are too small to spontaneously
form equilibrium structures in aqueous solutions, but form dynamic, noncovalent
assemblies, referred to as clusters. In the presence of a hydrophobic compound,
these clusters seem to get stabilized leading to the formation of long-lived,
highly stable mesoscopic droplets, a phenomenon that we call mesoscale
solubilization. In this work, we focus on the unusual mesoscopic properties of
aqueous solutions of a nonionic hydrotrope, namely tertiary butyl alcohol
(TBA), on addition of various hydrophobic compounds. Aqueous TBA solutions, in
about 3 to 8 mol percent TBA concentration range and about 0 to 25 deg. C
temperature range, show the presence of short-ranged (0.5 nm), short-lived
(tens of picoseconds) molecular clusters which result in anomalies of the
thermodynamic properties. These clusters are transient but do not relax by
diffusion, thus distinctly different from conventional concentration
fluctuations. In this concentration and temperature range, upon the addition of
a third (more hydrophobic) component to TBA-water solutions, long-lived
mesoscopic droplets of about 100 nm size are observed. In this work, we clarify
the ambiguity behind the definition of solubility and elucidate the phenomenon
of mesoscale solubilization. A systematic study of the macro and meso phase
behavior of three ternary systems TBA-water-propylene oxide, TBA-water-isobutyl
alcohol, and TBA-water-cyclohexane has been carried out. We differentiate
between molecular solubility, mesoscale solubilization, and macroscopic phase
separation. We have confirmed that practically stable aqueous colloids can be
created from small molecules, without addition of surfactants or polymers. Such
kind of novel materials may find applications in the design of various
processes and products, ranging from pharmaceuticals to cosmetics and
agrochemicals.


title:
Branching Ratios and CP Violations of B \to K_0^*(1430) K^* Decays in
  the pQCD Approach

abstract:
  We investigate $B \to K_0^*(1430) K^*$ decays in the perturbative QCD(pQCD)
factorization approach, where $B$ denotes $B_u$, $B_d$ and $B_s$ meson
respectively, and the scalar $K_0^*(1430)$ is considered as a meson based on
the model of conventional two-quark structure. With the light-cone distribution
amplitude of $K_0^*(1430)$ defined in two scenarios, namely Scenario 1 and
Scenario 2, we make the first estimation for the branching ratios and
CP-violating asymmetries for those concerned decay modes in the pQCD
factorization approach. For all considered $B \to K_0^*(1430) K^*$ decays in
this paper, only one preliminary upper limit on the branching ratio of $B^0 \to
{K_0^*(1430)}^0 \bar{K}^{*0}$ measured at 90% C.L. by Belle Collaboration is
available now. It is therefore of great interest to examine the predicted
physical quantities at two $B$ factories, Large Hadron Collider experiments,
and forthcoming Super-$B$ facility, then test the reliability of the pQCD
approach employed to study the considered decay modes involving a $p$-wave
scalar meson as one of the final state mesons. Furthermore, these pQCD
predictions combined with the future precision measurements are also helpful to
explore the complicated QCD dynamics involved in the light scalars.


title:
Measurement of the Antineutrino Neutral-Current Elastic Differential
  Cross Section

abstract:
  We report the measurement of the flux-averaged antineutrino neutral current
elastic scattering cross section ($d\sigma_{\bar \nu N \rightarrow \bar \nu
N}/dQ^{2}$) on CH$_{2}$ by the MiniBooNE experiment using the largest sample of
antineutrino neutral current elastic candidate events ever collected. The ratio
of the antineutrino to neutrino neutral current elastic scattering cross
sections and a ratio of antineutrino neutral current elastic to antineutrino
charged current quasi elastic cross section is also presented.


title:
Polylogarithmic Supports are required for Approximate Well-Supported
  Nash Equilibria below 2/3

abstract:
  In an epsilon-approximate Nash equilibrium, a player can gain at most epsilon
in expectation by unilateral deviation. An epsilon well-supported approximate
Nash equilibrium has the stronger requirement that every pure strategy used
with positive probability must have payoff within epsilon of the best response
payoff. Daskalakis, Mehta and Papadimitriou conjectured that every win-lose
bimatrix game has a 2/3-well-supported Nash equilibrium that uses supports of
cardinality at most three. Indeed, they showed that such an equilibrium will
exist subject to the correctness of a graph-theoretic conjecture. Regardless of
the correctness of this conjecture, we show that the barrier of a 2/3 payoff
guarantee cannot be broken with constant size supports; we construct win-lose
games that require supports of cardinality at least Omega((log n)^(1/3)) in any
epsilon-well supported equilibrium with epsilon < 2/3. The key tool in showing
the validity of the construction is a proof of a bipartite digraph variant of
the well-known Caccetta-Haggkvist conjecture. A probabilistic argument shows
that there exist epsilon-well-supported equilibria with supports of cardinality
O(log n/(epsilon^2)), for any epsilon> 0; thus, the polylogarithmic cardinality
bound presented cannot be greatly improved. We also show that for any delta >
0, there exist win-lose games for which no pair of strategies with support
sizes at most two is a (1-delta)-well-supported Nash equilibrium. In contrast,
every bimatrix game with payoffs in [0,1] has a 1/2-approximate Nash
equilibrium where the supports of the players have cardinality at most two.


title: W γ production in vector boson fusion at NLO in QCD

abstract:
  The next-to-leading order QCD corrections to W gamma production in
association with two jets via vector boson fusion are calculated, including the
leptonic decay of the W with full off-shell effects and spin correlations. The
process lends itself to a test of quartic gauge couplings. The next-to-leading
order corrections reduce the scale uncertainty significantly and show a
non-trivial phase space dependence.


title: Evidence for a Kondo destroying quantum critical point in YbRh2Si2

abstract:
  The heavy-fermion metal YbRh$_{2}$Si$_{2}$ is a weak antiferromagnet below
$T_{N} = 0.07$ K. Application of a low magnetic field $B_{c} = 0.06$ T ($\perp
c$) is sufficient to continuously suppress the antiferromagnetic (AF) order.
Below $T \approx 10$ K, the Sommerfeld coefficient of the electronic specific
heat $\gamma(T)$ exhibits a logarithmic divergence. At $T < 0.3$ K, $\gamma(T)
\sim T^{-\epsilon}$ ($\epsilon: 0.3 - 0.4$), while the electrical resistivity
$\rho(T) = \rho_{0} + aT$ ($\rho_{0}$: residual resistivity). Upon
extrapolating finite-$T$ data of transport and thermodynamic quantities to $T =
0$, one observes (i) a vanishing of the "Fermi surface crossover" scale
$T^{*}(B)$, (ii) an abrupt jump of the initial Hall coefficient $R_{H}(B)$ and
(iii) a violation of the Wiedemann Franz law at $B = B_{c}$, the field-induced
quantum critical point (QCP). These observations are interpreted as evidence of
a critical destruction of the heavy quasiparticles, i.e., propagating Kondo
singlets, at the QCP of this material.


title:
Detecting Fake Escrow Websites using Rich Fraud Cues and Kernel Based
  Methods

abstract:
  The ability to automatically detect fraudulent escrow websites is important
in order to alleviate online auction fraud. Despite research on related topics,
fake escrow website categorization has received little attention. In this study
we evaluated the effectiveness of various features and techniques for detecting
fake escrow websites. Our analysis included a rich set of features extracted
from web page text, image, and link information. We also proposed a composite
kernel tailored to represent the properties of fake websites, including content
duplication and structural attributes. Experiments were conducted to assess the
proposed features, techniques, and kernels on a test bed encompassing nearly
90,000 web pages derived from 410 legitimate and fake escrow sites. The
combination of an extended feature set and the composite kernel attained over
98% accuracy when differentiating fake sites from real ones, using the support
vector machines algorithm. The results suggest that automated web-based
information systems for detecting fake escrow sites could be feasible and may
be utilized as authentication mechanisms.


title: Design Elements that Promote the use of Fake Website Detection Tools

abstract:
  Fake websites have emerged as a major source of online fraud, accounting for
billions of dollars of loss by Internet users. We explore the process by which
salient design elements could increase the use of protective tools, thus
reducing the success rate of fake websites. Using the protection motivation
theory, we conceptualize a model to investigate how salient design elements of
detection tools could influence user perceptions of the tools, efficacy in
dealing with threats, and use of such tools. The research method was a
controlled lab experiment with a novel and extensive experimental design and
protocol. We found that trust in the detector is the pivotal coping mechanism
in dealing with security threats and is a major conduit for transforming
salient design elements into increased use. We also found that design elements
have profound and unexpected impacts on self-efficacy. The significant
theoretical and empirical implications of findings are discussed.


title: Can very compact and very massive neutron stars both exist?

abstract:
  The existence of neutron stars with masses of $\sim 2\,M_{\odot}$ requires a
stiff equation of state at high densities. On the other hand, the necessary
appearance also at high densities of new degrees of freedom, such as hyperons
and $\Delta$ resonances, can lead to a strong softening of the equation of
state with resulting maximum masses of $\sim 1.5\, M_{\odot}$ and radii smaller
than $\sim 10$ km. Hints for the existence of compact stellar objects with very
small radii have been found in recent statistical analysis of quiescent
low-mass X-ray binaries in globular clusters. We propose an interpretation of
these two apparently contradicting measurements, large masses and small radii,
in terms of two separate families of compact stars: hadronic stars, whose
equation of state is soft, can be very compact, while quark stars, whose
equation of state is stiff, can be very massive. In this respect an early
appearance of $\Delta$ resonances is crucial to guarantee the stability of the
branch of hadronic stars. Our proposal could be tested by measurements of radii
with an error of $\sim 1$ km, which is within reach of the planned LOFT
satellite, and it would be further strengthened by the discovery of compact
stars heavier than $\sim 2\,M_{\odot}$.


title: Robust Consensus in Distributed Networks using Total Variation

abstract:
  Consider a connected network of agents endowed with local cost functions
representing private objectives. Agents seek to find an agreement on some
minimizer of the aggregate cost, by means of repeated communications between
neighbors. Consensus on the average over the network, usually addressed by
gossip algorithms, is a special instance of this problem, corresponding to
quadratic private objectives. Consensus on the median, or more generally
quantiles, is also a special instance, as many more consensus problems. In this
paper we show that optimizing the aggregate cost function regularized by a
total variation term has appealing properties. First, it can be done very
naturally in a distributed way, yielding algorithms that are efficient on
numerical simulations. Secondly, the optimum for the regularized cost is shown
to be also the optimum for the initial aggregate cost function under
assumptions that are simple to state and easily verifiable. Finally, these
algorithms are robust to unreliable agents that keep injecting some false value
in the network. This is remarkable enough, and is not the case, for instance,
of gossip algorithms, that are entirely ruled by unreliable agents as detailed
in the paper.


title: Computing individual Kazhdan-Lusztig basis elements

abstract:
  In well-known work, Kazhdan and Lusztig (1979) defined a new set of Hecke
algebra basis elements (actually two such sets) associated to elements in any
Coxeter group. Often these basis elements are computed by a standard recursive
algorithm which, for Coxeter group elements of long length, generally involves
computing most basis elements corresponding to Coxeter group elements of
smaller length. Thus, many calculations simply compute all basis elements
associated to a given length or less, even if the interest is in a specific
Kazhdan-Lusztig basis element. Similar remarks apply to "parabolic" versions of
these basis elements defined later by Deodhar (1987,1990), though the lengths
involved are the (smaller) lengths of distinguished coset representatives. We
give an algorithm which targets any given Kazhdan-Lusztig basis element or
parabolic analog and does not precompute any other Kazhdan-Lusztig basis
elements. In particular it does not have to store them. This results in a
considerable saving in memory usage, enabling new calculations in an important
case (for finite and algebraic group 1-cohomology with irreducible
coefficients) analyzed by Scott-Xi (2010).


title: Evaluating Link-Based Techniques for Detecting Fake Pharmacy Websites

abstract:
  Fake online pharmacies have become increasingly pervasive, constituting over
90% of online pharmacy websites. There is a need for fake website detection
techniques capable of identifying fake online pharmacy websites with a high
degree of accuracy. In this study, we compared several well-known link-based
detection techniques on a large-scale test bed with the hyperlink graph
encompassing over 80 million links between 15.5 million web pages, including
1.2 million known legitimate and fake pharmacy pages. We found that the QoC and
QoL class propagation algorithms achieved an accuracy of over 90% on our
dataset. The results revealed that algorithms that incorporate dual class
propagation as well as inlink and outlink information, on page-level or
site-level graphs, are better suited for detecting fake pharmacy websites. In
addition, site-level analysis yielded significantly better results than
page-level analysis for most algorithms evaluated.


title: Cosmology and the Dark Matter Frontier

abstract:
  A brief overview is given about some issues in current astroparticle physics,
focusing on the dark matter (DM) problem, where the connection to LHC physics
is particularly strong. New data from the Planck satellite has made the
evidence in favour of the existence of DM even stronger. The favourite, though
not the only, candidates for cosmological DM, weakly interacting massive
particles (WIMPs), are being probed by a variety of experiments - direct
detection through scattering in terrestrial detectors, indirect detection by
observing products of annihilation of DM in the Galaxy, and finally searches at
accelerators such as the LHC. The field is in the interesting situation that
all of these search methods are reaching sensitivities where signals of DM may
plausibly soon be found, and a vast array of models will be probed in the next
few years. Of course, expectations for a positive signature are high, which
calls for caution regarding 'false alarms'. Some of the presently puzzling and
partly conflicting pieces of evidence for DM detection are discussed as well as
expectations for the future.


title:
The asymptotic distribution of the determinant of a random correlation
  matrix

abstract:
  Random correlation matrices are studied for both theoretical interestingness
and importance for applications. The author of [6] is interested in their
interpretation as covariance matrices of purely random signals, the authors of
[16] employ them in the generation of random clusters for studying clustering
methods, whereas the authors of [8] use them for studying subset selection in
multiple regression, etc. The determinant of a matrix is one of the most basic
and important matrix functions, and this makes studying the distribution of the
determinant of a random correlation matrix of paramount importance. Our main
result gives the asymptotic distribution of the determinant of a random
correlation matrix sampled from a uniform distribution over the space of $d
\times d$ correlation matrices. Several spin-off results are proven along the
way, and an interesting connection with the law of the determinant of general
random matrices, proven in [15], is investigated.


title: Tight-binding models in a quasiperiodic optical lattice

abstract:
  This paper describes how one can use four standing wave laser fields to
realize a two dimensional optical quasicrystal with eight-fold symmetry,
closely related to the well-known octagonal or Ammann-Beenker tiling
quasicrystal. We describe the structure and its properties, and the effective
tight-binding model for atoms in this optical quasicrystal. Such a system, if
realized experimentally, should provide valuable insights into the quantum
properties of quasicrystals.


title: Evaluating the Usefulness of Sentiment Information for Focused Crawlers

abstract:
  Despite the prevalence of sentiment-related content on the Web, there has
been limited work on focused crawlers capable of effectively collecting such
content. In this study, we evaluated the efficacy of using sentiment-related
information for enhanced focused crawling of opinion-rich web content regarding
a particular topic. We also assessed the impact of using sentiment-labeled web
graphs to further improve collection accuracy. Experimental results on a large
test bed encompassing over half a million web pages revealed that focused
crawlers utilizing sentiment information as well as sentiment-labeled web
graphs are capable of gathering more holistic collections of opinion-related
content regarding a particular topic. The results have important implications
for business and marketing intelligence gathering efforts in the Web 2.0 era.