title:
MAGIC reveals a complex morphology within the unidentified gamma-ray
  source HESS J1857+026

abstract:
  HESS J1857+026 is an extended TeV gamma-ray source that was discovered by
H.E.S.S. as part of its Galactic plane survey. Given its broadband spectral
energy distribution and its spatial coincidence with the young energetic pulsar
PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN)
candidate. MAGIC has performed follow-up observations aimed at mapping the
source down to energies approaching 100 GeV in order to better understand its
complex morphology. HESS J1857+026 was observed by MAGIC in 2010, yielding 29
hours of good quality stereoscopic data that allowed us to map the source
region in two separate ranges of energy. We detected very-high-energy gamma-ray
emission from HESS J1857+026 with a significance of $12 \sigma$ above $150$
GeV. The differential energy spectrum between $100$ GeV and $13$ TeV is well
described by a power law function $dN/dE = N_0(E/1\textrm{TeV})^{-\Gamma}$ with
$N_0 = (5.37 \pm0.44_{stat} \pm1.5_{sys}) \times 10^{-12} (\textrm{TeV}^{-1}
\textrm{cm}^{-2}$ $\textrm{ s}^{-1})$ and $\Gamma = 2.16\pm0.07_{stat}
\pm0.15_{sys}$, which bridges the gap between the GeV emission measured by
Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we
present a detailed analysis of the energy-dependent morphology of this region.
We couple these results with archival multi-wavelength data and outline
evidence in favor of a two-source scenario, whereby one source is associated
with a PWN, while the other could be linked with a molecular cloud complex
containing an HII region and a possible gas cavity.


title:
Group analysis of variable coefficient generalized fifth-order KdV
  equations

abstract:
  We carry out group analysis of a class of generalized fifth-order Korteweg-de
Vries equations with time dependent coefficients. Admissible transformations,
Lie symmetries and similarity reductions of equations from the class are
classified exhaustively. A criterion of reducibility of variable coefficient
fifth-order KdV equations to their constant coefficient counterparts is
derived. Some exact solutions are presented.


title: On weighted Hardy inequalities for non-increasing sequences

abstract:
  A result of Bennett and Grosse-Erdmann characterizes the weights for which
the corresponding weighted Hardy inequality holds on the cone of non-negative,
non-increasing sequences and a bound for the best constant is given. In this
paper, we improve the bound for $1<p \leq 2$.


title:
Characteristic Functions Describing the Power Absorption Response of
  Periodic Structures to Partially Coherent Fields

abstract:
  Many new types of sensing or imaging surfaces are based on periodic thin
films. It is explained how the response of those surfaces to partially coherent
fields can be fully characterized by a set of functions in the wavenumber
spectrum domain. The theory is developed here for the case of 2D absorbers with
TE illumination and arbitrary material properties in the plane of the problem,
except for the resistivity which is assumed isotropic. Sum and difference
coordinates in both spatial and spectral domains are conveniently used to
represent the characteristic functions, which are specialized here to the case
of periodic structures. Those functions can be either computed or obtained
experimentally. Simulations rely on solvers based on periodic-boundary
conditions, while experiments correspond to Energy Absorption Interferometry
(EAI), already described in the literature. We derive rules for the convergence
of the representation versus the number of characteristic functions used, as
well as for the sampling to be considered in EAI experiments. Numerical
examples are given for the case of absorbing strips printed on a semi-infinite
substrate.


title:
Strong openness conjecture and related problems for plurisubharmonic
  functions

abstract:
  In this article, we solve the strong openness conjecture on the multiplier
ideal sheaves for the plurisubharmonic functions posed by Demailly. We prove
two conjectures about the growth of the volumes of the sublevel sets of
plurisubharmonic functions related to the complex singularity exponents and
quasi-plurisubharmonic functions related to the jumping numbers, which were
posed by Demailly-Koll\'{a}r and Jonsson-Mustat\u{a} respectively. We give a
new proof of a lower semicontinuity conjecture posed by Demailly-Koll\'{a}r
without using the ACC conjecture. Other applications by combining with
well-known results are also mentioned.


title:
Orbital-resolved vortex core states in FeSe Superconductors: calculation
  based on a three-orbital model

abstract:
  We study electronic structure of vortex core states of FeSe superconductors
based on a t$_{2g}$ three-orbital model by solving the Bogoliubov-de
Gennes(BdG) equation self-consistently. The orbital-resolved vortex core states
of different pairing symmetries manifest themselves as distinguishable
structures due to different quasi-particle wavefunctions. The obtained vortices
are classified in terms of the invariant subgroups of the symmetry group of the
mean-field Hamiltonian in the presence of magnetic field. Isotropic $s$ and
anisotropic $s$ wave vortices have $G_5$ symmetry for each orbital, whereas
$d_{x^2-y^2}$ wave vortices show $G^{*}_{6}$ symmetry for $d_{xz/yz}$ orbitals
and $G^{*}_{5}$ symmetry for $d_{xy}$ orbital. In the case of $d_{x^2-y^2}$
wave vortices, hybridized-pairing between $d_{xz}$ and $d_{yz}$ orbitals gives
rise to a relative phase difference in terms of gauge transformed pairing order
parameters between $d_{xz/yz}$ and $d_{xy}$ orbitals, which is essentially
caused by a transformation of co-representation of $G^{*}_{5}$ and $G^{*}_{6}$
subgroup. The calculated local density of states(LDOS) of $d_{x^2-y^2}$ wave
vortices show qualitatively similar pattern with experiment results. The phase
difference of $\frac{\pi}{4}$ between $d_{xz/yz}$ and $d_{xy}$ orbital-resolved
$d_{x^2-y^2}$ wave vortices can be verified by further experiment observation.


title: Causality and momentum conservation from relative locality

abstract:
  Theories with a curved momentum space, which became recently of interest in
the quantum-gravity literature, can in general violate many apparently robust
aspects of our current description of the laws of physics, including
relativistic invariance, locality, causality and global momentum conservation.
We here explore some aspects of the particularly severe pathologies arising in
generic theories with curved momentum space for what concerns causality and
momentum conservation. However, we also report results suggesting that when
momentum space is maximally symmetric, and the theory is formulated
(DSR-)relativistically, with the associated relativity of spacetime locality,
momentum is globally conserved and there is no violation of causality.


title:
Circular Sphere Decoding: A Low Complexity Detection for MIMO Systems
  with General Two-dimensional Signal Constellations

abstract:
  We propose a low complexity complex valued Sphere Decoding (CV-SD) algorithm,
referred to as Circular Sphere Decoding (CSD) which is applicable to
multiple-input multiple-output (MIMO) systems with arbitrary two dimensional
(2D) constellations. CSD provides a new constraint test. This constraint test
is carefully designed so that the element-wise dependency is removed in the
metric computation for the test. As a result, the constraint test becomes
simple to perform without restriction on its constellation structure. By
additionally employing this simple test as a prescreening test, CSD reduces the
complexity of the CV-SD search. We show that the complexity reduction is
significant while its maximum-likelihood (ML) performance is not compromised.
We also provide a powerful tool to estimate the pruning capacity of any
particular search tree. Using this tool, we propose the Predict-And-Change
strategy which leads to a further complexity reduction in CSD. Extension of the
proposed methods to soft output SD is also presented.


title: Superconducting nano-mechanical diamond resonators

abstract:
  In this work we present the fabrication and characterization of
superconducting nano-mechanical resonators made from nanocrystalline boron
doped diamond (BDD). The oscillators can be driven and read out in their
superconducting state and show quality factors as high as 40,000 at a resonance
frequency of around 10 MHz. Mechanical damping is studied for magnetic fields
up to 3 T where the resonators still show superconducting properties. Due to
their simple fabrication procedure, the devices can easily be coupled to other
superconducting circuits and their performance is comparable with
state-of-the-art technology.


title: On the Puzzle of Long and Short Gamma-Ray Bursts

abstract:
  In this paper we give a brief review of our recent studies on the long and
short gamma-ray bursts (GRBs) detected Swift, in an effort to understand the
puzzle of classifying GRBs. We consider that it is still an appealing
conjecture that both long and short GRBs are drawn from the same parent sample
by observational biases.


title:
Three-dimensional patchy lattice model: ring formation and phase
  separation

abstract:
  We investigate the structural and thermodynamic properties of a model of
particles with $2$ patches of type $A$ and $10$ patches of type $B$. Particles
are placed on the sites of a face centered cubic lattice with the patches
oriented along the nearest neighbor directions. The competition between the
self-assembly of chains, rings and networks on the phase diagram is
investigated by carrying out a systematic investigation of this class of
models, using an extension of Wertheim's theory for associating fluids and
Monte Carlo numerical simulations. We varied the ratio
$r\equiv\epsilon_{AB}/\epsilon_{AA}$ of the interaction between patches $A$ and
$B$, $\epsilon_{AB}$, and between $A$ patches, $\epsilon_{AA}$ ($\epsilon_{BB}$
is set to $0$) as well as the relative position of the $A$ patches, i.e., the
angle $\theta$ between the (lattice) directions of the $A$ patches. We found
that both $r$ and $\theta$ ($60^\circ,90^\circ,$ or $120^\circ$) have a
profound effect on the phase diagram. In the empty fluid regime ($r < 1/2$) the
phase diagram is re-entrant with a closed miscibility loop. The region around
the lower critical point exhibits unusual structural and thermodynamic behavior
determined by the presence of relatively short rings. The agreement between the
results of theory and simulation is excellent for $\theta=120^\circ$ but
deteriorates as $\theta$ decreases, revealing the need for new theoretical
approaches to describe the structure and thermodynamics of systems dominated by
small rings.


title:
Temperature and phase-space density of cold atom cloud in a quadrupole
  magnetic trap

abstract:
  We present studies on the modifications in temperature, number density and
phase-space density when a laser cooled atom cloud from the optical molasses is
trapped in a quadrupole magnetic trap. Theoretically it is shown that for a
given temperature and size of the cloud from the molasses, the phase-space
density in the magnetic trap first increases with magnetic field gradient and
then decreases with it, after attaining a maximum value at an optimum value of
magnetic field gradient. The experimentally measured variation in phase-space
density in the magnetic trap with the magnetic field gradient has shown the
similar trend. However, the experimentally measured values of number density
and phase-space density are much lower than their theoretically predicted
values. This is attributed to the higher experimentally observed temperature in
the magnetic trap than the theoretically predicted temperature. Nevertheless,
these studies can be useful to set a higher phase-space density in the trap by
setting the optimum value of field gradient of the quadrupole magnetic trap.


title:
Current-driven filamentation upstream of magnetized relativistic
  collisionless shocks

abstract:
  The physics of instabilities in the precursor of relativistic collisionless
shocks is of broad importance in high energy astrophysics, because these
instabilities build up the shock, control the particle acceleration process and
generate the magnetic fields in which the accelerated particles radiate. Two
crucial parameters control the micro-physics of these shocks: the magnetization
of the ambient medium and the Lorentz factor of the shock front; as of today,
much of this parameter space remains to be explored. In the present paper, we
report on a new instability upstream of electron-positron relativistic shocks
and we argue that this instability shapes the micro-physics at moderate
magnetization levels and/or large Lorentz factors. This instability is seeded
by the electric current carried by the accelerated particles in the shock
precursor as they gyrate around the background magnetic field. The compensation
current induced in the background plasma leads to an unstable configuration,
with the appearance of charge neutral filaments carrying a current of the same
polarity, oriented along the perpendicular current. This ``current-driven
filamentation'' instability grows faster than any other instability studied so
far upstream of relativistic shocks, with a growth rate comparable to the
plasma frequency. Furthermore, the compensation of the current is associated
with a slow-down of the ambient plasma as it penetrates the shock precursor (as
viewed in the shock rest frame). This slow-down of the plasma implies that the
``current driven filamentation'' instability can grow for any value of the
shock Lorentz factor, provided the magnetization \sigma <~ 10^{-2}. We argue
that this instability explains the results of recent particle-in-cell
simulations in the mildly magnetized regime.


title:
Preservation of coherence for a Two-Level atom tunneling through a
  squeezed vacuum with finite bandwidth

abstract:
  Tunneling of a two-state particle through a squeezed vacuum is considered. It
has been shown that repetitive measurement or interaction with the external
field can preserve the coherence. Moreover, the coherence time in terms of the
squeezing parameters has been calculated. A specific condition is derived,
under which the coherence is sustainable.


title: Dynamics of a monodisperse Lennard-Jones system on a sphere

abstract:
  We investigate by Molecular Dynamics simulation a system of $N$ particles
moving on the surface of a two-dimensional sphere and interacting by a
Lennard-Jones potential. We detail the way to account for the changes brought
by a nonzero curvature, both at a methodological and at a physical level. When
compared to a two-dimensional Lennard-Jones liquid on the Euclidean plane,
where a phase transition to an ordered hexagonal phase takes place, we find
that the presence of excess defects imposed by the topology of the sphere
frustrates the hexagonal order. We observe at high density a rapid increase of
the relaxation time when the temperature is decreased, whereas in the same
range of temperature the pair correlation function of the system evolves only
moderately.


title:
On the Evaluation of the Polyanskiy-Poor-Verdu Converse Bound for Finite
  Blocklength Coding in AWGN

abstract:
  A tight converse bound to channel coding rate in the finite block-length
regime and under AWGN conditions was recently proposed by Polyanskiy, Poor, and
Verdu (PPV). The bound is a generalization of a number of other classical
results, and it was also claimed to be equivalent to Shannon's 1959 cone
packing bound. Unfortunately, its numerical evaluation is troublesome even for
not too large values of the block-length n. In this paper we tackle the
numerical evaluation by compactly expressing the PPV converse bound in terms of
non-central chi-squared distributions, and by evaluating those through a an
integral expression and a corresponding series expansion which exploit a method
proposed by Temme. As a result, a robust evaluation method and new insights on
the bound's asymptotics, as well as new approximate expressions, are given.


title: Self-affinity in financial asset returns

abstract:
  We test for departures from normal and independent and identically
distributed (NIID) returns, when returns under the alternative hypothesis are
self-affine. Self-affine returns are either fractionally integrated and
long-range dependent, or drawn randomly from an L-stable distribution with
infinite higher-order moments. The finite sample performance of estimators of
the two forms of self-affinity is explored in a simulation study which
demonstrates that, unlike rescaled range analysis and other conventional
estimation methods, the variant of fluctuation analysis that considers finite
sample moments only is able to identify either form of self-affinity. However,
when returns are self-affine and long-range dependent under the alternative
hypothesis, rescaled range analysis has greater power than fluctuation
analysis. The finite-sample properties of the estimators when returns exhibit
either form of self-affinity can be exploited to determine the source of
self-affinity in empirical returns data. The techniques are illustrated by
means of an analysis of the fractal properties of the daily logarithmic returns
for the indices of 11 stock markets.


title: Probably Safe or Live

abstract:
  This paper presents a formal characterisation of safety and liveness
properties \`a la Alpern and Schneider for fully probabilistic systems. As for
the classical setting, it is established that any (probabilistic tree) property
is equivalent to a conjunction of a safety and liveness property. A simple
algorithm is provided to obtain such property decomposition for flat
probabilistic CTL (PCTL). A safe fragment of PCTL is identified that provides a
sound and complete characterisation of safety properties. For liveness
properties, we provide two PCTL fragments, a sound and a complete one. We show
that safety properties only have finite counterexamples, whereas liveness
properties have none. We compare our characterisation for qualitative
properties with the one for branching time properties by Manolios and Trefler,
and present sound and complete PCTL fragments for characterising the notions of
strong safety and absolute liveness coined by Sistla.


title: On the AdS stability problem

abstract:
  We discuss the notion of stability and the choice of boundary conditions for
AdS-type space-times and point out difficulties in the construction of Cauchy
data which arise if reflective boundary conditions are imposed.


title:
A-posteriori error estimates for the localized reduced basis multi-scale
  method

abstract:
  We present a localized a-posteriori error estimate for the localized reduced
basis multi-scale (LRBMS) method [Albrecht, Haasdonk, Kaulmann, Ohlberger
(2012): The localized reduced basis multiscale method]. The LRBMS is a
combination of numerical multi-scale methods and model reduction using reduced
basis methods to efficiently reduce the computational complexity of parametric
multi-scale problems with respect to the multi-scale parameter $\varepsilon$
and the online parameter $\mu$ simultaneously. We formulate the LRBMS based on
a generalization of the SWIPDG discretization presented in [Ern, Stephansen,
Vohralik (2010): Guaranteed and robust discontinuous Galerkin a posteriori
error estimates for convection-diffusion-reaction problems] on a coarse
partition of the domain that allows for any suitable discretization on the fine
triangulation inside each coarse grid element. The estimator is based on the
idea of a conforming reconstruction of the discrete diffusive flux, that can be
computed using local information only. It is offline/online decomposable and
can thus be efficiently used in the context of model reduction.


title: Sculpturing the Electron Wave Function

abstract:
  Coherent electrons such as those in electron microscopes, exhibit wave
phenomena and may be described by the paraxial wave equation. In analogy to
light-waves, governed by the same equation, these electrons share many of the
fundamental traits and dynamics of photons. Today, spatial manipulation of
electron beams is achieved mainly using electrostatic and magnetic fields.
Other demonstrations include simple phase-plates and holographic masks based on
binary diffraction gratings. Altering the spatial profile of the beam may be
proven useful in many fields incorporating phase microscopy, electron
holography, and electron-matter interactions. These methods, however, are
fundamentally limited due to energy distribution to undesired diffraction
orders as well as by their binary construction. Here we present a new method in
electron-optics for arbitrarily shaping of electron beams, by precisely
controlling an engineered pattern of thicknesses on a thin-membrane, thereby
molding the spatial phase of the electron wavefront. Aided by the past decade's
monumental leap in nano-fabrication technology and armed with light-optic's
vast experience and knowledge, one may now spatially manipulate an electron
beam's phase in much the same way light waves are shaped simply by passing them
through glass elements such as refractive and diffractive lenses. We show
examples of binary and continuous phase-plates and demonstrate the ability to
generate arbitrary shapes of the electron wave function using a holographic
phase-mask. This opens exciting new possibilities for microscopic studies of
materials using shaped electron beams and enables electron beam lithography
without the need to move the electron beam or the sample, as well as high
resolution inspection of electronic chips by structured electron illumination.


title: Asymmetric Levy flights in nonhomogeneous environments

abstract:
  We consider stochastic systems involving general -- non-Gaussian and
asymmetric -- stable processes. The random quantities, either a stochastic
force or a waiting time in a random walk process, explicitly depend on the
position. A fractional diffusion equation corresponding to a master equation
for a jumping process with a variable jumping rate is solved in a diffusion
limit. It is demonstrated that for some model parameters the equation is
satisfied in that limit by the stable process with the same asymptotics as the
driving noise. The Langevin equation containing a multiplicative noise,
depending on the position as a power-law, is solved; the existing moments are
evaluated. The motion appears subdiffusive and the transport depends on the
asymmetry parameter: it is fastest for the symmetric case. A special case of
the one-sided distribution is discussed.


title: Do dipole correlations exist in two-dimensional spin ice?

abstract:
  Here we study the statistical properties of two-dimensional spin ice in its
ground state by the Monte Carlo simulation method. Using a new sampling
algorithm, we show that the short-range ice rule in two dimensions gives rise
to long-range but not dipole-like correlations, to non-Gaussian probability
density function for magnetization and to non-extensive conditional entropy
(entropy with given value of magnetization).


title: New observations of the old magnetic nova GQ Muscae

abstract:
  We report photometric observations of GQ Mus performed between 1992 and 2011.
We find that the total amplitude of the orbital modulation of its brightness
decreased from ~0.9 mag in 1992 to ~0.2 mag in 2010, becoming comparable to the
amplitude of chaotic flickering on a time scale of several minutes. Optical
spectra obtained in 2001 and 2012 indicate continuing activity of GQ Mus. The
spectra show broad emission lines of HeII and HI typical for magnetic
cataclysmic variables. The nova was observed as an UV-bright object in 2001 and
2012. We also show that the orbital period of GQ Mus has been constant between
1989 and 2010-2011.


title:
Stationary and quasi-stationary light pulse in three-level cold atomic
  system

abstract:
  We have studied stationary and quasi-stationary signal light pulses in cold
lambda-type atomic media driven by counterpropagating control laser fields at
the condition of electromagnetically induced transparency. By deriving a
dispersion relation we present spectral and temporal properties of the signal
light pulse and a significant influence of atomic decoherence on the coupled
stationary light pulses for spatial splitting. Finally we discuss
quasi-stationary light pulse evolution characterized by frozen spatial
spreading for a robust coherent control of slow light pulses.


title: On generalized Ramanujan primes

abstract:
  In this paper we establish several results concerning the generalized
Ramanujan primes. For $n\in\mathbb{N}$ and $k \in \mathbb{R}_{> 1}$ we give
estimates for the $n$th $k$-Ramanujan prime which lead both to generalizations
and to improvements of the results presently in the literature. Moreover, we
obtain results about the distribution of $k$-Ramanujan primes. In addition, we
find explicit formulae for certain $n$th $k$-Ramanujan primes. As an
application, we prove that a conjecture of Mitra, Paul and Sarkar concerning
the number of primes in certain intervals holds for every sufficiently large
positive integer.


title: Stabilization Mechanism of ZnO nanoparticles by Fe doping

abstract:
  Surprisingly low solubility and toxicity of Fe-doped ZnO nanoparticles is
elucidated on the basis of first-principles calculations. Various ZnO surfaces
that could be present in nanoparticles are subject to substitutional Fe doping.
We show that Fe stabilizes polar instable surfaces, while non-polar surfaces,
namely (1010) and (1120), remain intact. Polar surfaces can be stabilized
indirectly through Fe2+-Fe3+ pair assisted charge transfer, what reduces
surface polarity and therefore, the solubility in polar solvents.


title: Optimizing a spin-flip Zeeman slower

abstract:
  We present a design of a spin-flip Zeeman slower controlled by a fast
feedback circuit for a sodium Bose-Einstein condensate apparatus. We also
demonstrate how the efficiency of the slower strongly depends on its intrinsic
parameters, and compare these observations with a few theoretical models. Our
findings lead to a simple three-step procedure of designing an optimal Zeeman
slower for neutral atoms, especially for those atomic species with high initial
velocities, such as sodium and lithium atoms.


title:
Existence, unique continuation and symmetry of least energy nodal
  solutions to sublinear Neumann problems

abstract:
  We consider the sublinear problem \begin {equation*} \left\{\begin{array}{r c
l c} -\Delta u & = &|u|^{q-2}u & \textrm{in }\Omega, \\ u_n & = & 0 &
\textrm{on }\partial\Omega,\end{array}\right. \end {equation*} where $\Omega
\subset \real^N$ is a bounded domain, and $1 \leq q < 2$. For $q=1$,
$|u|^{q-2}u$ will be identified with $\sgn(u)$. We establish a variational
principle for least energy nodal solutions, and we investigate their
qualitative properties. In particular, we show that they satisfy a unique
continuation property (their zero set is Lebesgue-negligible). Moreover, if
$\Omega$ is radial, then least energy nodal solutions are foliated Schwarz
symmetric, and they are nonradial in case $\Omega$ is a ball. The case $q=1$
requires special treatment since the formally associated energy functional is
not differentiable, and many arguments have to be adjusted.


title: On the independence ratio of distance graphs

abstract:
  A distance graph is an undirected graph on the integers where two integers
are adjacent if their difference is in a prescribed distance set. The
independence ratio of a distance graph $G$ is the maximum density of an
independent set in $G$. Lih, Liu, and Zhu [Star extremal circulant graphs, SIAM
J. Discrete Math. 12 (1999) 491--499] showed that the independence ratio is
equal to the inverse of the fractional chromatic number, thus relating the
concept to the well studied question of finding the chromatic number of
distance graphs.
  We prove that the independence ratio of a distance graph is achieved by a
periodic set, and we present a framework for discharging arguments to
demonstrate upper bounds on the independence ratio. With these tools, we
determine the exact independence ratio for several infinite families of
distance sets of size three, determine asymptotic values for others, and
present several conjectures.


title: Measurements of Riemannian two-disks and two-spheres

abstract:
  We prove that any Riemannian two-sphere with area at most 1 can be
continuously mapped onto a tree in a such a way that the topology of fibers is
controlled and their length is less than 7.6. This result improves previous
estimates and relies on a similar statement for Riemannian two-disks.


title: Blowing in the wind: The dust wave surrounding $\sigma$ Ori AB

abstract:
  Observations with the Spitzer Space Telescope and the WISE satellite have
revealed a prominent arc-like structure at 50" ($\simeq0.1$ pc) from the
O9.5V/B0.5V system $\sigma$ Ori AB. We attribute this dust structure to the
interaction of radiation pressure from the star with dust carried along by the
IC 434 photo-evaporative flow of ionized gas from the dark cloud L1630. We have
developed a quantitative model for the interaction of a dusty ionized flow with
nearby (massive) stars where radiation pressure stalls dust, piling it up at an
appreciable distance (> 0.1 pc), and force it to flow around the star. The
model demonstrates that for the conditions in IC 434, the gas will decouple
from the dust and will keep its original flow lines. We argue that this dust
structure is the first example of a dust wave created by a massive star moving
through the interstellar medium. Dust waves (and bow waves) stratify dust
grains according to their radiation pressure opacity, which reflects the size
distribution and composition of the grain material. Comparison of our model
with observations implies that dust-gas coupling through Coulomb interaction is
less important than previously thought, challenging our understanding of grain
dynamics in hot, ionized regions of space. We describe the difference between
dust (and bow) waves and classical bow shocks. We conclude that dust waves and
bow waves should be common around stars showing the weak-wind phenomenon and
that these structures are best observed at mid-IR to FIR wavelengths. In
particular, dust waves and bow waves are most efficiently formed around
weak-wind stars moving through a high density medium. Moreover, they provide a
unique opportunity to study the direct interaction between a (massive) star and
its immediate surroundings.


title: Linear Koszul duality and Fourier transform for convolution algebras

abstract:
  In this paper we prove that the linear Koszul duality isomorphism for
convolution algebras in K-homology defined in a previous paper and the Fourier
transform isomorphism for convolution algebras in Borel-Moore homology are
related by the Chern character. So, Koszul duality appears as a categorical
upgrade of Fourier transform of constructible sheaves. This result explains the
connection between the categorification of the Iwahori-Matsumoto involution for
graded affine Hecke algebras (due to Evens and the first author) and for usual
affine Hecke algebras (obtained in a previous paper).


title:
Fractional heat equations with subcritical absorption having a measure
  as initial data

abstract:
  We study existence and uniqueness of weak solutions to (F) $\partial\_t u+
(-\Delta)^\alphau+h(t, u)=0 $ in $(0,\infty)\times\R^N$,with initial condition
$u(0,\cdot)=\nu$ in $\R^N$, where $N\ge2$, the operator $(-\Delta)^\alpha$is
the fractional Laplacian with $\alpha\in(0,1)$, $\nu$ isa bounded Radon measure
and $h:(0,\infty)\times\R\to\R$ is a continuous function satisfying a
subcritical integrability condition.In particular, if $h(t,u)=t^\beta u^p$ with
$\beta\textgreater{}-1$ and $0 \textless{} p \textless{}
p^*\_\beta:=1+\frac{2\alpha(1+\beta)}{N}$, we prove that there exists a unique
weak solution $u\_k$ to (F) with $\nu=k\delta\_0$, where $\delta\_0$ is the
Dirac mass at the origin. We obtain that $u\_k\to\infty$ in
$(0,\infty)\times\R^N$ as $k\to\infty$ for $p\in(0,1]$ and the limit of $u\_k$
exists as $k\to\infty$ when $1 \textless{} p \textless{} p^*\_\beta$, we denote
it by $u\_\infty$.When
$1+\frac{2\alpha(1+\beta)}{N+2\alpha}:=p^{**}\_\beta\textless{} p \textless{}
p^*\_\beta$,$u\_\infty$ is the minimal self-similar solution of $(F)\_\infty$
$\partial\_t u+ (-\Delta)^\alpha u+t^\beta u^p=0 $ in $(0,\infty)\times\R^N$
with the initial condition $u(0,\cdot)=0$ in $\R^N\setminus\{0\}$ and it
satisfies $u\_\infty(0,x)=0$ for $x\neq 0$.While if $1\textless{} p \textless{}
p^{**}\_\beta$, then $u\_\infty\equiv U\_p$, where $U\_p$ is the maximal
solution of the differential equation $y'+t^\beta y^p=0$ on $\R\_+$.


title: Network Connectivity: Stochastic vs. Deterministic Wireless Channels

abstract:
  We study the effect of stochastic wireless channel models on the connectivity
of ad hoc networks. Unlike in the deterministic geometric disk model where
nodes connect if they are within a certain distance from each other, stochastic
models attempt to capture small-scale fading effects due to shadowing and
multipath received signals. Through analysis of local and global network
observables, we present conclusive evidence suggesting that network behaviour
is highly dependent upon whether a stochastic or deterministic connection model
is employed. Specifically we show that the network mean degree is lower
(higher) for stochastic wireless channels than for deterministic ones, if the
path loss exponent is greater (lesser) than the spatial dimension. Similarly,
the probability of forming isolated pairs of nodes in an otherwise dense random
network is much less for stochastic wireless channels than for deterministic
ones. The latter realisation explains why the upper bound of $k$-connectivity
is tighter for stochastic wireless channels. We obtain closed form analytic
results and compare to extensive numerical simulations.


title: Negative index Jacobi forms and quantum modular forms

abstract:
  In this paper, we consider the Fourier coefficients of a special class of
meromorphic Jaocbi forms of negative index. Much recent work has been done on
such coefficients in the case of Jacobi forms of positive index, but almost
nothing is known for Jacobi forms of negative index. In this paper we show,
from two different perspectives, that their Fourier coefficients have a simple
decomposition in terms of partial theta functions. The first perspective uses
the language of Lie super algebras, and the second applies the theory of
elliptic functions. In particular, we find a new infinite family of rank-crank
type PDEs generalizing the famous example of Atkin and Garvan. We then describe
the modularity properties of these coefficients, showing that they are "mixed
partial theta functions", along the way determining a new class of quantum
modular partial theta functions which is of independent interest.


title: Global wake instabilities of low aspect-ratio flate-plates

abstract:
  This paper investigates the linear destabilization of three-dimensional
steady wakes developing behind flate plates placed normal to the incoming flow.
Plates characterized by low length-to-width ratio $L$ are considered here. By
varying this aspect ratio in the range $1 \le L \le 6$ three destabilization
scenarios are identified. For very low aspect ratio $1 \le L \le 2$, the flow
is first destabilized, when increasing the Reynolds number,by a steady global
mode that breaks the top/bottom planar reflectional symmetry. The symmetric
steady flow bifurcates, via a pitchfork bifurcation, towards an asymmetric
steady wakes, similarly to the case of axisymmetric wakes behind sphere and
disks. For long aspect ratio, $2.5 \le L \le 6$, the first unstable mode also
breaks the top/bottom symmetry but is unsteady. A Hopf bifurcation occurs, as
for the wake developing behind a two-dimensional circular cylinder. Finally an
intermediate regime $2 \le L \le 2.5$ is found for which the flow gets first
unstable to an unsteady mode that breaks the left/right planar reflectional
symmetry.


title: Modeling Life as Cognitive Info-Computation

abstract:
  This article presents a naturalist approach to cognition understood as a
network of info-computational, autopoietic processes in living systems. It
provides a conceptual framework for the unified view of cognition as evolved
from the simplest to the most complex organisms, based on new empirical and
theoretical results. It addresses three fundamental questions: what cognition
is, how cognition works and what cognition does at different levels of
complexity of living organisms. By explicating the info-computational character
of cognition, its evolution, agent-dependency and generative mechanisms we can
better understand its life-sustaining and life-propagating role. The
info-computational approach contributes to rethinking cognition as a process of
natural computation in living beings that can be applied for cognitive
computation in artificial systems.


title: Functionals on Closed 2-Surfaces

abstract:
  We show that the 2-torus in ${\mathbb R}^3$ is a critical point of a sequence
of functionals ${\cal F}_{n}$ ($n=1,2,3, \cdots$) defined over compact
2-surfaces in ${\mathbb R}^3$. When the Lagrange function ${\cal E}$ is a
polynomial of degree $n$ of the mean curvature $H$ of the surface, the radii
($a,r$) of the 2-torus are related as $\frac{a^2}{r^2}=\frac{n^2-n}{n^2-n-1}, n
\ge 2$. If the Lagrange function depends on both mean and Gaussian curvatures,
the 2- torus remains to be a critical point of ${\cal F}_{n}$ without any
constraints on the radii of the torus.


title:
Visualizing Cognitive Moves for Assessing Information Perception Biases
  in Decision Making

abstract:
  In decision making a key source of uncertainty is people's perception of
information which is influenced by their attitudes toward risk. Both,
perception of information and risk attitude, affect the interpretation of
information and hence the choice of suitable courses of action in a variety of
contexts ranging from project planning to military operations. Visualization
associated with the dynamics of cognitive states of people processing
information and making decision is therefore not only important for analysis
but has also significant practical applications, in particular in the military
command and control domain. In this paper, we focus on a major concept that
affect human cognition in this context: reliability of information. We
introduce Cognitive Move Diagrams (CMD)---a simple visualization tool---to
represent and evaluate the impact of this concept on decision making. We
demonstrate through both a hypothetical example and a subject matter expert
based experiment that CMD are effective in visualizing, detecting and
qualifying human biases.


title: Polygonal Dissections and Reversions of Series

abstract:
  The Catalan numbers $C_k$ were first studied by Euler, in the context of
enumerating triangulations of polygons $P_{k+2}$. Among the many
generalizations of this sequence, the Fuss-Catalan numbers $C^{(d)}_k$ count
enumerations of dissections of polygons $P_{k(d-1)+2}$ into $(d+1)$-gons. In
this paper, we provide a formula enumerating polygonal dissections of
$(n+2)$-gons, classified by partitions $\lambda$ of $[n]$. We connect these
counts $a_{\lambda}$ to reverse series arising from iterated polynomials.
Generalizing this further, we show that the coefficients of the reverse series
of polynomials $x=z-\sum_{j=0}^{\infty} b_j z^{j+1}$ enumerate colored
polygonal dissections.


title: Estimation for the Linear Model with Uncertain Covariance Matrices

abstract:
  We derive a maximum a posteriori estimator for the linear observation model,
where the signal and noise covariance matrices are both uncertain. The
uncertainties are treated probabilistically by modeling the covariance matrices
with prior inverse-Wishart distributions. The nonconvex problem of jointly
estimating the signal of interest and the covariance matrices is tackled by a
computationally efficient fixed-point iteration as well as an approximate
variational Bayes solution. The statistical performance of estimators is
compared numerically to state-of-the-art estimators from the literature and
shown to perform favorably.


title: Shock-cloud interaction and particle acceleration in SN 1006

abstract:
  The supernova remnant SN 1006 is a powerful source of high-energy particles
and evolves in a relatively tenuous and uniform environment, though interacting
with an atomic cloud in its northwestern limb. The X-ray image of SN 1006
reveals an indentation in the southwestern part of the shock front and the HI
maps show an isolated cloud (southwestern cloud) having the same velocity as
the northwestern cloud and whose morphology fits perfectly in the indentation.
We performed spatially resolved spectral analysis of a set of small regions in
the southwestern nonthermal limb and studied the deep X-ray spectra obtained
within the XMM-Newton SN 1006 Large Program. We also analyzed archive HI data,
obtained combining single dish and interferometric observations. We found that
the best-fit value of the N_H derived from the X-ray spectra significantly
increases in regions corresponding to the southwestern cloud, while the cutoff
energy of the synchrotron emission decreases. The amount of the N_H variations
corresponds perfectly with the HI column density of the southwestern cloud, as
measured from the radio data. The decrease in the cutoff energy at the
indentation clearly reveals that the back side of the cloud is actually
interacting with the remnant. The southwestern limb therefore presents a unique
combination of efficient particle acceleration and high ambient density, thus
being the most promising region for gamma-ray hadronic emission in SN 1006. We
estimate that such emission will be detectable with the Fermi telescope within
a few years.


title: On the Bellman function of Nazarov, Treil and Volberg

abstract:
  We give an explicit formula for the Bellman function associated with the dual
bound related to the unconditional constant of the Haar system.


title:
Arbitrage of the first kind and filtration enlargements in
  semimartingale financial models

abstract:
  In a general semimartingale financial model, we study the stability of the No
Arbitrage of the First Kind (NA1) (or, equivalently, No Unbounded Profit with
Bounded Risk) condition under initial and under progressive filtration
enlargements. In both cases, we provide a simple and general condition which is
sufficient to ensure this stability for any fixed semimartingale model.
Furthermore, we give a characterisation of the NA1 stability for all
semimartingale models.


title: Stochastic Hydrodynamic Synchronization in Rotating Energy Landscapes

abstract:
  Hydrodynamic synchronization provides a general mechanism for the spontaneous
emergence of coherent beating states in independently driven mesoscopic
oscillators. A complete physical picture of those phenomena is of definite
importance to the understanding of biological cooperative motions of cilia and
flagella. Moreover, it can potentially suggest novel routes to exploit
synchronization in technological applications of soft matter. We demonstrate
that driving colloidal particles in rotating energy landscapes results in a
strong tendency towards synchronization, favouring states where all beads
rotate in phase. The resulting dynamics can be described in terms of activated
jumps with transition rates that are strongly affected by hydrodynamics leading
to an increased probability and lifetime of the synchronous states. Using
holographic optical tweezers we quantitatively verify our predictions in a
variety of spatial configurations of rotors.


title: Seiberg Duality, 5d SCFTs and Nekrasov Partition Functions

abstract:
  It is known that a 4d N = 1 SCFT lives on D3-branes probing a local del Pezzo
Calabi-Yau singularity. The Seiberg (or toric) duality of this SCFT arises from
the Picard-Lefshetz transformation of the affine E_N 7-brane background that is
associated with the Calabi-Yau threefold. In this paper we study the duality of
the affine E_N background itself and a 5-brane probing it. We then find that
many different Type IIB 5-brane webs describe the same SCFT in 5d. We check
this duality by comparing the Nekrasov partition functions of these 5-brane web
configurations.


title:
Persistent metal-insulator transition at the surface of an
  oxygen-deficient, epitaxial manganite film

abstract:
  The oxygen stoichiometry has a large influence on the physical and chemical
properties of complex oxides. Most of the functionality in e.g. catalysis and
electrochemistry depends in particular on control of the oxygen stoichiometry.
In order to understand the fundamental properties of intrinsic surfaces of
oxygen-deficient complex oxides, we report on in situ temperature dependent
scanning tunnelling spectroscopy experiments on pristine oxygen deficient,
epitaxial manganite films. Although these films are insulating in subsequent ex
situ in-plane electronic transport experiments at all temperatures, in situ
scanning tunnelling spectroscopic data reveal that the surface of these films
exhibits a metal-insulator transition (MIT) at 120 K, coincident with the onset
of ferromagnetic ordering of small clusters in the bulk of the oxygen-deficient
film. The surprising proximity of the surface MIT transition temperature of
nonstoichiometric films with that of the fully oxygenated bulk suggests that
the electronic properties in the surface region are not significantly affected
by oxygen deficiency in the bulk. This carries important implications for the
understanding and functional design of complex oxides and their interfaces with
specific electronic properties for catalysis, oxide electronics and
electrochemistry.


title:
Splitting bright matter-wave solitons on narrow potential barriers:
  quantum to classical transition and applications to interferometry

abstract:
  We study bright solitons in the Gross-Pitaevskii equation as they are split
and recombined in a low energy system. We present new analytic results
determining the general region in which a soliton may not be split on a
potential barrier, and confirm these results numerically. Furthermore, we
analyse the energetic regimes where quantum fluctuations in the initial center
of mass position and momentum become influential on the outcome of soliton
splitting and recombination events. We then use the results of this analysis to
determine a parameter regime where soliton interferometry is practicable.


title: Conjugacy languages in groups

abstract:
  We study the regularity of several languages derived from conjugacy classes
in a finitely generated group G for a variety of examples including word
hyperbolic, virtually abelian, Artin, and Garside groups. We also determine the
rationality of the growth series of the shortlex conjugacy language in
virtually cyclic groups, proving one direction of a conjecture of Rivin.


title:
One loop radiative correction to Kaluza-Klein masses in $S^2/Z_2$
  universal extra dimensional model

abstract:
  We investigate a radiative correction to the masses of Kaluza-Klein(KK) modes
in a universal extra dimensional model which are defined on a six-dimensional
spacetime with extra space as a two-sphere orbifold $S^2/Z_2$. We first define
the Feynman rules which are necessary for the calculation. We then calculate
the one-loop diagrams which contribute to the radiative corrections to the KK
masses, and obtain one-loop corrections to masses for fermions, gauge bosons
and scalar bosons. We estimate the one-loop corrections to KK masses for the
first KK modes of standard model particles as a function of momentum cut-off
scale, and we determine the lightest KK particle which would be a promising
candidate of a dark matter.


title:
Beyond the Hubble scale: Super cosmic variance and nongaussianity as a
  portal to the superhorizon

abstract:
  If cosmological perturbations in our Hubble sized volume are nongaussian,
then they will be coupled to any larger perturbation modes outside our Hubble
volume. This has important consequences for modeling inflation: the scalar
power spectrum and spectral index measured in our Hubble volume would depend on
an adjacent background of super Hubble perturbations. In other words, a
detection of nongaussianity implies a possible portal to the superhorizon. By
the same token, ruling out nongaussianity would rule out the possibility that
the power spectrum's size and running are accidents of super cosmic variance.
In this note, we provide a compact derivation of super cosmic variance, survey
recent results, and show how experimental limits on nongaussianity help to rule
it out.


title: Using the s-Ensemble to Probe Glasses Formed by Cooling and Aging

abstract:
  From length scale distributions characterizing frozen amorphous domains, we
relate the s-ensemble method with standard cooling and aging protocols for
forming glass. We show that in a general class of models, where space-time
scaling is in harmony with that of experiment, the domain size distributions
obtained with the s-ensemble are identical to those obtained through cooling or
aging, but the computational effort for applying the s-ensemble is generally
many orders of magnitude smaller than that of straightforward numerical
simulation of cooling or aging.


title:
Parton density constraints from massive vector boson production at the
  LHC

abstract:
  We demonstrate that not only the production of virtual photons decaying into
low-mass lepton pairs, but also the one of weak bosons at large transverse
momenta is dominated by quark-gluon scattering. Measurements of these processes
at the LHC can therefore provide useful constraints on the parton densities in
the proton, in particular the one of the gluon, and their nuclear
modifications.


title:
Every symplectic toric orbifold is a centered reduction of a Cartesian
  product of weighted projective spaces

abstract:
  We prove that every symplectic toric orbifold is a centered reduction of a
Cartesian product of weighted projective spaces. A theorem of Abreu and
Macarini shows that if the level set of the reduction passes through a
non-displaceable set then the image of this set in the reduced space is also
non-displaceable. Using this result we show that every symplectic toric
orbifold contains a non-displaceable fiber and we identify this fiber.


title: Oblique repulsion in the nonnegative quadrant

abstract:
  We consider an electrostatic attractive-repulsive differential system in the
nonnegative quadrant. Under some condition on the constants there exists a
unique global solution. The main difficulty is to prove uniqueness when
starting at the corner of the quadrant.


title:
Collisionless Relativistic Shocks:current driven turbulence and particle
  acceleration

abstract:
  The physics of collisionless relativistic shocks with a moderate
magnetization is presented. Micro-physics is relevant to explain the most
energetic radiative phenomena of Nature, namely that of the termination shock
of Gamma Ray Bursts. A transition towards Fermi process occurs for decreasing
magnetization around a critical value which turns out to be the condition for
the scattering to break the mean field inhibition. Scattering is produced by
magnetic micro-turbulence driven by the current carried by returning particles,
which had not been considered till now, but turns out to be more intense than
Weibel's one around the transition. The current is also responsible for a
buffer effect on the motion of the incoming flow, on which the threshold for
the onset of turbulence depends.


title: Measuring the Orbital Angular Momentum of Electron Beams

abstract:
  The recent demonstration of electron vortex beams has opened up the new
possibility of studying orbital angular momentum (OAM) in the interaction
between electron beams and matter. To this aim, methods to analyze the OAM of
an electron beam are fundamentally important and a necessary next step. We
demonstrate the measurement of electron beam OAM through a variety of
techniques. The use of forked holographic masks, diffraction from geometric
apertures, diffraction from a knife-edge and the application of an astigmatic
lens are all experimentally demonstrated. The viability and limitations of each
are discussed with supporting numerical simulations.


title: Space and time in a quantized world

abstract:
  Rather than an a priori arena in which events take place, space-time is a
construction of our mind making possible a particular kind of ordering of
events. As quantum entanglement is a property of states independent of
classical distances, the notion of space and time has to be revised to
represent the holistic interconnection of quanta. We also speculate about
various forms of reprogramming, or reconfiguring, the propagation of
information for multipartite statistics and in quantum field theory.


title:
Existence and convergence of Galerkin approximation for second order
  hyperbolic equations with memory

abstract:
  We study a second order hyperbolic initial-boundary value partial
differential equation with memory, that results in an integro-differential
equation with a convolution kernel. The kernel is assumed to be either smooth
or no worse than weakly singular, that arise, e.g. in linear and fractional
order viscoelasticity. Existence and uniqueness of the spatial local and global
Galerkin approximation of the problem is proved by means of Picard iteration.
Then spatial finite element approximation of the problem is formulated, and
optimal order a priori error estimates are proved by energy method. The
required regularity of the solution, for optimal order convergence, is the same
as minimum regularity of the solution for second order hyperbolic partial
differential equations.


title:
Exploring dependence between categorical variables: benefits and
  limitations of using variable selection within Bayesian clustering in
  relation to log-linear modelling with interaction terms

abstract:
  This manuscript is concerned with relating two approaches that can be used to
explore complex dependence structures between categorical variables, namely
Bayesian partitioning of the covariate space incorporating a variable selection
procedure that highlights the covariates that drive the clustering, and
log-linear modelling with interaction terms. We derive theoretical results on
this relation and discuss if they can be employed to assist log-linear model
determination, demonstrating advantages and limitations with simulated and real
data sets. The main advantage concerns sparse contingency tables. Inferences
from clustering can potentially reduce the number of covariates considered and,
subsequently, the number of competing log-linear models, making the exploration
of the model space feasible. Variable selection within clustering can inform on
marginal independence in general, thus allowing for a more efficient
exploration of the log-linear model space. However, we show that the clustering
structure is not informative on the existence of interactions in a consistent
manner. This work is of interest to those who utilize log-linear models, as
well as practitioners such as epidemiologists that use clustering models to
reduce the dimensionality in the data and to reveal interesting patterns on how
covariates combine.


title:
Direct Measurement of the Surface Tension of a Soft Elastic Hydrogel:
  Exploration of Elasto-Capillary Instability in Adhesion

abstract:
  An adhesively stressed thin film of a soft hydrogel confined between two
rigid flat substrates auto-roughens with its dominant wavelength exhibiting
pronounced dependence on the film thickness (H). A linear stability analysis
confirmed that this long wavelength instability (~7H) is due to an
elasto-capillary effect, the implementation of which required direct
measurements of the surface tension and the elasticity of the gel. The surface
tension of the gel was estimated from the fundamental spherical harmonic of a
hemispherical cap of the gel that was excited by an external noise. The shear
modulus of the gel was determined from its resonant shear mode in a confined
geometry. During the course of this study, it was found that a high density
steel ball submerges itself inside the gel by balancing its excess weight with
the accumulated strain induced elastic force that allows another estimation of
its elastic modulus. The large ratio (1.8 mm) of the surface tension to its
elasticity ascertains the role of elasto-capillarity in the adhesion induced
pattern formation with such gels. Experimental results are in accord with a
linear stability analysis that predicts that the rescaled wavelength is linear
with H, which modifies the conventional stress to pull-off a rigid flat object
from a very soft film by a multiplicative factor. The analysis also suggests
some new results related to the role of the finite dilation of a material in
interfacial pattern formation that may have non-trivial consequences in the
adhesive delamination of very thin and/or soft elastic films via self-generated
cracks.


title: Reconfigurable Structures for Direct Equalisation in Mobile Receivers

abstract:
  Any communication channel will usually distort the transmitted signal. This
is especially true in the case of mobile systems, where multipath propagation
causes the received signal to be seriously degraded. Over the years, many
techniques have been proposed to combat channel effects. Two of the most
popular are linear equalisation (LE) and decision feedback equalisation (DFE).
These methods offer a good compromise between performance and computational
complexity. LE and DFE are implemented using finite impulse response (FIR)
filters whose frequency spectrum approximates the inverse of the channel
spectrum plus noise. In mobile systems, the equaliser is made adaptable in
order to be able to respond to the channel variations. Adaptability is achieved
using adaptive FIR filters whose coefficients are iteratively updated. In
principle, an infinite number of filter coefficients would be needed to achieve
perfect channel inversion. In practice, the number of taps must be finite.
Simulations show that, in realistic scenarios, making the equaliser longer than
a certain (undetermined) number of taps will not yield any benefit. Moreover,
computation and power will be wasted. In battery powered devices, like mobile
terminals, it would be desirable to have the equaliser properly dimensioned.
The equaliser's optimum length strongly depends on the particular scenario, and
as channel conditions vary, this optimum is likely to vary. This thesis
presents novel techniques to perform equaliser length adjustment. Methods for
the LE and the DFE have been developed. Simulations in many different scenarios
show that the proposed schemes optimise the number of taps to be used.
Moreover, these techniques are able to detect changes in the channel and
re-adjust the equaliser length appropriately.


title: Small Inner Companions of Warm Jupiters: Lifetimes and Legacies

abstract:
  Although warm jupiters are generally too far from their stars for tides to be
important, the presence of an inner planetary companion to a warm jupiter can
result in tidal evolution of the system. Insight into the process and its
effects comes form classical secular theory of planetary perturbations. The
lifetime of the inner planet may be shorter than the age of the system, because
the warm jupiter maintains its eccentricity and hence promotes tidal migration
into the star. Thus a warm jupiter observed to be alone in its system might
have previously cleared away any interior planets. Before its demise, even if
an inner planet is of terrestrial scale, it may promote damping of the warm
jupiter's eccentricity. Thus any inferences of the initial orbit of an observed
warm jupiter must include the possibility of a greater initial eccentricity
than would be estimated by assuming it had always been alone. Tidal evolution
involving multiple planets also enhances the internal heating of the planets,
which readily exceeds that of stellar radiation for the inner planet, and may
be great enough to affect the internal structure of warm jupiters. Secular
theory gives insight into the tidal processes, providing, among other things, a
way to constrain eccentricities of transiting planets based on estimates of the
tidal parameter Q.


title: The oscillating behavior of the pair correlation function in galaxies

abstract:
  The pair correlation function (PCF) for galaxies presents typical
oscillations in the range 20-200 Mpc/h which are named baryon acoustic
oscillation (BAO). We first review and test the oscillations of the PCF when
the 2D/3D vertexes of the Poissonian Voronoi Tessellation (PVT) are considered.
We then model the behavior of the PCF at a small scale in the presence of an
auto gravitating medium having a line/plane of symmetry in 2D/3D. The analysis
of the PCF in an astrophysical context was split into two, adopting a
non-Poissonian Voronoi Tessellation (NPVT). We first analyzed the case of a 2D
cut which covers few voids and a 2D cut which covers approximately 50 voids.
The obtained PCF in the case of many voids was then discussed in comparison to
the bootstrap predictions for a PVT process and the observed PCF for an
astronomical catalog. An approximated formula which connects the averaged
radius of the cosmic voids to the first minimum of the PCF is given.


title:
Surface Folding Induced Attraction and Motion of Particles in a Soft
  Elastic Gel: Cooperative Effects of Surface Tension, Elasticity and Gravity

abstract:
  We report, for the first time, some experimental observations regarding a new
type of long range interaction between rigid particles that prevails when they
are suspended in an soft elastic gel. A denser particle submerges itself to a
considerable depth inside the gel and becomes buoyant by balancing its weight
against the elastic force exerted by the surrounding medium. By virtue of a
large elastic-capillary length, the surface of the gel wraps around the
particle and closes to create a line singularity connecting the particle to the
free surface of the gel. Substantial amount of tensile strain is thus developed
in the gel network parallel to the free surface that penetrates to a
significant depth inside the gel. The field of this tensile strain is rather
long range owing to a large correlation length and strong enough to pull two
submerged particles into contact. The particles move towards each other with an
effective force following an inverse linear distance law. When more monomers or
dimers of the particles are released inside the gel, they orient rather freely
inside the capsules they are in, and attract each other to form close packed
clusters. Eventually, these clusters themselves interact and coalesce. This is
an emergent phenomenon in which the gravity, the capillarity and the elasticity
work in tandem to create a long range interaction. We also present the results
of a related experiment, in which a particle suspended inside a thickness
graded gel moves accompanied by the continuous folding and the relaxation of
the surface of the gel.


title: Category Theory Using String Diagrams

abstract:
  In work of Fokkinga and Meertens a calculational approach to category theory
is developed. The scheme has many merits, but sacrifices useful type
information in the move to an equational style of reasoning. By contrast,
traditional proofs by diagram pasting retain the vital type information, but
poorly express the reasoning and development of categorical proofs. In order to
combine the strengths of these two perspectives, we propose the use of string
diagrams, common folklore in the category theory community, allowing us to
retain the type information whilst pursuing a calculational form of proof.
These graphical representations provide a topological perspective on
categorical proofs, and silently handle functoriality and naturality conditions
that require awkward bookkeeping in more traditional notation.
  Our approach is to proceed primarily by example, systematically applying
graphical techniques to many aspects of category theory. We develop string
diagrammatic formulations of many common notions, including adjunctions,
monads, Kan extensions, limits and colimits. We describe representable functors
graphically, and exploit these as a uniform source of graphical calculation
rules for many category theoretic concepts. These graphical tools are then used
to explicitly prove many standard results in our proposed diagrammatic style.


title:
Tides, planetary companions, and habitability: Habitability in the
  habitable zone of low-mass stars

abstract:
  Earth-scale planets in the classical habitable zone (HZ) are more likely to
be habitable if they possess active geophysics. Without a constant internal
energy source, planets cool as they age, eventually terminating tectonic
activity and rendering the planet sterile to life. However, for planets
orbiting low-mass stars, the presence of an outer companion could generate
enough tidal heat in the HZ planet to prevent such cooling. The range of mass
and orbital parameters for the companion that give adequate long-term heating
of the inner HZ planet, while avoiding very early total desiccation, is
probably substantial. We locate the ideal location for the outer of a pair of
planets, under the assumption that the inner planet has the same incident flux
as Earth, orbiting example stars: a generic late M dwarf ($T_{eff}=2670 K$) and
the M9V/L0 dwarf DEN1048. Thus discoveries of Earth-scale planets in the HZ
zone of old small stars should be followed by searches for outer companion
planets that might be essential for current habitability.


title: On derived categories and noncommutative motives of varieties

abstract:
  In this short note we show how results of Orlov and To\"en imply that any
equivalence between the derived categories of coherent sheaves on two varieties
lifts to an equivalence at the level of dg-categories. This establishes the
link between the noncommutative geometry practised by the school of
Bondal-Orlov, and the variant developed by Kontsevich and Tabuada. As an
application we recover Orlov's result that the derived category determines the
Chow motive with rational coefficients up to Tate twists.


title: X-ray observation of ULAS J1120+0641, the most distant quasar at z=7.08

abstract:
  We aim at probing the emission mechanism of the accreting super massive black
holes in the high redshift Universe. We study the X-ray spectrum of
ULAS1120+0641, the highest redshift quasar detected so far at z=7.085, which
has been deeply observed (340 ks) by XMM-Newton. Despite the long integration
time the spectral analysis is limited by the poor statistics, with only 150
source counts being detected. We measured the spectrum in the 2-80 keV
rest-frame (0.3-10 keV observed) energy band. Assuming a simple power law model
we find a photon index of 2.0+/-0.3 and a luminosity of 6.7+/-0.3 10^44 erg/s
in the 2-10 keV band, while the intrinsic absorbing column can be only loosely
constrained (NH< 1E23 cm^-2). Combining our data with published data we
calculate that the X-ray-to-optical spectral index alpha_OX is1.8+/-0.1, in
agreement with the alpha_OX-UV luminosity correlation valid for lower redshift
quasars. We expanded to high energies the coverage of the spectral energy
distribution of ULAS1120+0641. This is the second time that a z >6 quasar has
been investigated through a deep X-ray observation. In agreement with previous
studies of z~6 AGN samples, we do not find any hint of evolution in the
broadband energy distribution. Indeed from our dataset ULAS 1120+0641 is
indistinguishable from the population of optically bright quasar at lower
redshift.


title: Is ergodicity a reasonable hypothesis?

abstract:
  In the physics literature "ergodicity" is taken to mean that a system,
including a macroscopic one, visits all microscopic states in a relatively
short time. We show that this is an impossibility even if that time is billions
of years. We also suggest that this feature does not contradict most physical
considerations since those considerations deal with correlations of only a few
particles.


title: Relative entropy, interaction energy and the nature of dissipation

abstract:
  Many thermodynamic relations involve inequalities, with equality if a process
does not involve dissipation. In this article we provide equalities in which
the dissipative contribution is shown to involve the relative entropy (a.k.a.
Kullback-Leibler divergence). The processes considered are general time
evolutions both in classical and quantum mechanics, and the initial state is
sometimes thermal, sometimes partially so. By calculating a transport
coefficient we show that indeed---at least in this case---the source of
dissipation in that coefficient is the relative entropy.

categories: cond-mat.stat-mech math-ph math.MP physics.chem-ph


title:
Determinant Quantum Monte Carlo Study of d-wave pairing in the Plaquette
  Hubbard Hamiltonian

abstract:
  Determinant Quantum Monte Carlo (DQMC) is used to determine the pairing and
magnetic response for a Hubbard model built up from four-site clusters -a
two-dimensional square lattice consisting of elemental 2x2 plaquettes with
hopping $t$ and on-site repulsion $U$ coupled by an inter-plaquette hopping $t'
\leq t$. Superconductivity in this geometry has previously been studied by a
variety of analytic and numeric methods, with differing conclusions concerning
whether the pairing correlations and transition temperature are raised near
half-filling by the inhomogeneous hopping or not. For $U/t=4$, DQMC indicates
an optimal $t'/t \approx 0.4$ at which the pairing vertex is most attractive.
The optimal $t'/t$ increases with $U/t$. We then contrast our results for this
plaquette model with a Hamiltonian which instead involves a regular pattern of
site energies whose large site energy limit is the three band CuO$_2$ model; we
show that there the inhomogeneity rapidly, and monotonically, suppresses
pairing.


title:
A Two-Level Variant of Additive Schwarz Preconditioning for Use in
  Reservoir Simulation

abstract:
  The computation time for reservoir simulation is dominated by the linear
solver. The sets of linear equations which arise in reservoir simulation have
two distinctive features: the problems are usually highly anisotropic, with a
dominant vertical flow direction, and the commonly used fully implicit method
requires a simultaneous solution for pressure and saturation or molar
concentration variables. These variables behave quite differently, with the
pressure feeling long-range effects while the saturations vary locally. In this
paper we review preconditioned iterative methods used for solving the linear
system equations in reservoir simulation and their parallelisation. We then
propose a variant of the classical additive Schwarz preconditioner designed to
achieve better results on a large number of processors and discuss some
directions for future research.


title:
Fractality and other properties of center domains at finite temperature
  Part 1: SU(3) lattice gauge theory

abstract:
  Using finite temperature SU(3) lattice gauge theory in the fixed scale
approach we analyze center properties of the local Polyakov loop L(x). We
construct spatial clusters of points x where the phase of L(x) is near the same
center element and study their properties as a function of temperature. We find
that below the deconfinement transition the clusters form objects with a
fractal dimension D < 3. As the temperature is increased, the largest cluster
starts to percolate and its dimensionality approaches D=3. The fractal
structure of the clusters in the transition region may have implications
regarding both the small shear viscosity and the large opacity of the Quark
Gluon Plasma observed in heavy-ion collision experiments.


title:
MIMO Multiway Relaying with Pairwise Data Exchange: A Degrees of Freedom
  Perspective

abstract:
  In this paper, we study achievable degrees of freedom (DoF) of a
multiple-input multiple-output (MIMO) multiway relay channel (mRC) where $K$
users, each equipped with $M$ antennas, exchange messages in a pairwise manner
via a common $N$-antenna relay node. % A novel and systematic way of joint
beamforming design at the users and at the relay is proposed to align signals
for efficient implementation of physical-layer network coding (PNC). It is
shown that, when the user number $K=3$, the proposed beamforming design can
achieve the DoF capacity of the considered mRC for any $(M,N)$ setups. % For
the scenarios with $K>3$, we show that the proposed signaling scheme can be
improved by disabling a portion of relay antennas so as to align signals more
efficiently. Our analysis reveals that the obtained achievable DoF is always
piecewise linear, and is bounded either by the number of user antennas $M$ or
by the number of relay antennas $N$. Further, we show that the DoF capacity can
be achieved for $\frac{M}{N} \in \left(0,\frac{K-1}{K(K-2)} \right]$ and
$\frac{M}{N} \in \left[\frac{1}{K(K-1)}+\frac{1}{2},\infty \right)$, which
provides a broader range of the DoF capacity than the existing results.
Asymptotic DoF as $K\rightarrow \infty$ is also derived based on the proposed
signaling scheme.


title:
Energy dependence of potential barriers and its effect on fusion
  cross-sections

abstract:
  Couplings between relative motion and internal structures are known to affect
fusion barriers by dynamically modifying the densities of the colliding nuclei.
The effect is expected to be stronger at energies near the barrier top, where
changes in density have longer time to develop than at higher energies.
Quantitatively, modern TDHF calculations are able to predict realistic fusion
thresholds. However, the evolution of the potential barrier with bombarding
energy remains to be confronted with the experimental data. The aim is to find
signatures of the energy dependence of the barrier by comparing fusion
cross-sections calculated from potentials obtained at different bombarding
energies with the experimental data. This comparison is made for the
$^{40}$Ca+$^{40}$Ca and $^{16}$O+$^{208}$Pb systems. Fusion cross-sections are
computed from potentials calculated with the density-constrained TDHF method.
The couplings decrease the barrier at low-energy in both cases. A deviation
from the Woods-Saxon nuclear potential is also observed at the lowest energies.
In general, fusion cross-sections around a given energy are better reproduced
by the potential calculated at this energy. The coordinate-dependent mass plays
a crucial role for the reproduction of sub-barrier fusion cross-sections.
Effects of the energy dependence of the potential can be found in experimental
barrier distributions only if the variation of the barrier is significant in
the energy-range spanned by the distribution. It appears to be the case for
$^{16}$O+$^{208}$Pb but not for $^{40}$Ca+$^{40}$Ca. These results show that
the energy dependence of the barrier predicted in TDHF calculations is
realistic. This confirms that the TDHF approach can be used to study the
couplings between relative motion and internal degrees of freedom in heavy-ion
collisions.


title: Some variants of the classical Aubin-Lions Lemma

abstract:
  This paper explores two generalizations of the classical Aubin-Lions Lemma.
First we give a sufficient condition to commute weak limit and multiplication
of two functions. We deduce from this criteria a compactness Theorem for
degenerate parabolic equations. Secondly, we state and prove a compactness
Theorem for non-cylindrical domains, including the case of dual estimates
involving only divergence-free test functions.


title: Strangeness on the nucleon

abstract:
  Observables from parity violation in elastic electron-nucleon scattering and
neutral current quasi-elastic neutrino-nucleus scattering are employed as tools
to improve the current knowledge on the strangeness content in the nucleon.


title: Measuring large-scale social networks with high resolution

abstract:
  This paper describes the deployment of a large-scale study designed to
measure human interactions across a variety of communication channels, with
high temporal resolution and spanning multiple years - the Copenhagen Networks
Study. Specifically, we collect data on face-to-face interactions,
telecommunication, social networks, location, and background information
(personality, demographic, health, politics) for a densely connected population
of 1,000 individuals, using state-of-art smartphones as social sensors. Here we
provide an overview of the related work and describe the motivation and
research agenda driving the study. Additionally the paper details the
data-types measured, and the technical infrastructure in terms of both backend
and phone software, as well as an outline of the deployment procedures. We
document the participant privacy procedures and their underlying principles.
The paper is concluded with early results from data analysis, illustrating the
importance of multi-channel high-resolution approach to data collection.


title: Propositional dynamic logic for searching games with errors

abstract:
  We investigate some finitely-valued generalizations of propositional dynamic
logic with tests. We start by introducing the (n+1)-valued Kripke models and a
corresponding language based on a modal extension of {\L}ukasiewicz many-valued
logic. We illustrate the definitions by providing a framework for an analysis
of the R\'enyi - Ulam searching game with errors.
  Our main result is the axiomatization of the theory of the (n+1)-valued
Kripke models. This result is obtained through filtration of the canonical
model of the smallest (n+1)-valued propositional dynamic logic.


title:
Projective-geometric aspects of homogeneous third-order Hamiltonian
  operators

abstract:
  We investigate homogeneous third-order Hamiltonian operators of
differential-geometric type. Based on the correspondence with quadratic line
complexes, a complete list of such operators for two and three components is
obtained.


title: Anti-holomorphic involutions of the moduli spaces of Higgs bundles

abstract:
  We study anti-holomorphic involutions of the moduli space of principal
$G$-Higgs bundles over a compact Riemann surface $X$, where $G$ is a complex
semisimple Lie group. These involutions are defined by fixing anti-holomorphic
involutions on both $X$ and $G$. We analyze the fixed point locus in the moduli
space and their relation with representations of the orbifold fundamental group
of $X$ equipped with the anti-holomorphic involution. We also study the
relation with branes. This generalizes work by
Biswas--Garc\'{\i}a-Prada--Hurtubise and Baraglia--Schaposnik.


title: Simulating star formation in Ophiuchus

abstract:
  We have simulated star formation in prestellar cores, using SPH and initial
conditions informed by observations of the cores in Ophiuchus. Because the
observations are limited to two spatial dimensions plus radial velocity, we
cannot infer initial conditions for the collapse of a particular core. However,
with a minimum of assumptions (isotropic turbulence with a power-law spectrum,
a thermal mix of compressive and solenoidal modes, a critical Bonnor-Ebert
density profile) we can generate initial conditions that match, in a
statistical sense, the distributions of mass, projected size and aspect ratio,
thermal and non-thermal one-dimensional velocity dispersion, observed in
Ophiuchus. The time between core-core collisions in Ophiuchus is sufficiently
long, that we can simulate single cores evolving is isolation, and therefore we
are able to resolve masses well below the opacity limit. We generate an
ensemble of 100 cores, and evolve them with no radiative feedback from the
stars formed, then with continuous radiative feedback, and finally with
episodic radiative feedback. With no feedback the simulations produce too many
brown dwarfs, and with continuous feedback too few. With episodic radiative
feedback, both the peak of the protostellar mass function (at ~ 0.2 M_sun) and
the ratio of H-burning stars to brown dwarfs are consistent with observations.
The mass of a star is not strongly related to the mass of the core in which it
forms. Low-mass cores (M ~ 0.1 M_sun) tend to collapse into single objects,
whereas high-mass cores (1 > M_sun) usually fragment into several objects with
a broad mass range.


title:
Effect of one-, two-, and three-body atom loss processes on
  superpositions of phase states in Bose-Josephson junctions

abstract:
  In a two-mode Bose-Josephson junction formed by a binary mixture of ultracold
atoms, macroscopic superpositions of phase states are produced during the time
evolution after a sudden quench to zero of the coupling amplitude. Using
quantum trajectories and an exact diagonalization of the master equation, we
study the effect of one-, two-, and three-body atom losses on the
superpositions by analyzing separately the amount of quantum correlations in
each subspace with fixed atom number. The quantum correlations useful for atom
interferometry are estimated using the quantum Fisher information. We identify
the choice of parameters leading to the largest Fisher information, thereby
showing that, for all kinds of loss processes, quantum correlations can be
partially protected from decoherence when the losses are strongly asymmetric in
the two modes.


title:
Contexts of diffusion: Adoption of research synthesis in Social Work and
  Women's Studies

abstract:
  Texts reveal the subjects of interest in research fields, and the values,
beliefs, and practices of researchers. In this study, texts are examined
through bibliometric mapping and topic modeling to provide a birds eye view of
the social dynamics associated with the diffusion of research synthesis methods
in the contexts of Social Work and Women's Studies. Research synthesis texts
are especially revealing because the methods, which include meta-analysis and
systematic review, are reliant on the availability of past research and data,
sometimes idealized as objective, egalitarian approaches to research
evaluation, fundamentally tied to past research practices, and performed with
the goal informing future research and practice. This study highlights the
co-influence of past and subsequent research within research fields;
illustrates dynamics of the diffusion process; and provides insight into the
cultural contexts of research in Social Work and Women's Studies. This study
suggests the potential to further develop bibliometric mapping and topic
modeling techniques to inform research problem selection and resource
allocation.


title:
Coherent spin transport and suppression of spin relaxation in InSb
  nanowires with single subband occupancy at room temperature

abstract:
  A longstanding goal of spintronics is to inject, coherently transport, and
detect spins in a semiconductor nanowire where a SINGLE quantized subband is
occupied at room temperature. Here, we report achieving this goal in 50-nm
diameter InSb nanowires by demonstrating both the spin-valve and the Hanle
effect. The spin relaxation time in the nanowires was found to have increased
by an order of magnitude over what has been reported in bulk and quantum wells
due to the suppression of D'yakonov-Perel' spin relaxation as a result of
single subband occupancy. These experiments raise hopes for the realization of
a room-temperature Datta-Das spin transistor.


title:
Markov adaptive P\'olya trees and multi-resolution adaptive shrinkage in
  nonparametric modeling

abstract:
  We introduce a hierarchical nonparametric model for probability measures
based on a multi-resolution transformation of probability distributions. The
model allows a varying amount of shrinkage to be applied to data features of
different scales and/or at different locations in the sample space, and the
varying shrinkage level is locally adaptive to the empirical behavior of the
data. Moreover, the model's hierarchical design---through a latent Markov tree
structure---allows borrowing of information across locations and scales in
setting the adaptive shrinkage level. Inference under the model proceeds
efficiently using general recipes for conjugate hierarchical models. We
illustrate the work of the model in density estimation and evaluate its
performance through simulation under several schematic scenarios carefully
designed to be representative of a variety of applications. We compare its
performance to those of several state-of-the-art nonparametric models---the
P\'olya tree, the optional P\'olya tree, and the Dirichlet process mixture of
normals. In addition, we establish several important theoretical properties for
the model including absolute continuity, full nonparametricity, and posterior
consistency.


title: Specific Salt Effects on Thermophoresis of Charged Colloids

abstract:
  We study the Soret effect of charged polystyrene particles as a function of
temperature and electrolyte composition. As a main result we find that the
Soret coefficient is determined by charge effects, and that non-ionic
contributions are small. In view of the well-kown electric-double layer
interactions, our thermal field-flow fractionation data lead us to the
conclusion that the Soret effect originates to a large extent from
diffusiophoresis in the salt gradient and from the electrolyte Seebeck effect,
both of which show strong specific-ion effects. Moreover, we find that
thermophoresis of polystyrene beads is fundamentally different from proteins
and aqueous polymer solutions, which show a strong non-ionic contribution.


title:
Evidence for leptonic CP phase from NO$\nu$A, T2K and ICAL: A
  chronological progression

abstract:
  We study the synergy between the long-baseline (LBL) experiments NO$\nu$A and
T2K and the atmospheric neutrino experiment ICAL@INO for obtaining the first
hint of CP violation in the lepton sector. We also discuss how precisely the
leptonic CP phase ($\delta_{CP}$) can be measured by these experiments. The CP
sensitivity is first described at the level of oscillation probabilities,
discussing its dependence on the parameters -- $\theta_{13}$, mass hierarchy
and $\theta_{23}$. In particular, we discuss how the precise knowledge or lack
thereof of these parameters can affect the CP sensitivity of LBL experiments.
We follow a staged approach and analyze the $\delta_{CP}$ sensitivity that can
be achieved at different points of time over the next 15 years from these LBL
experiments alone and/or in conjunction with ICAL@INO. We find that the CP
sensitivity of NO$\nu$A/T2K is enhanced due to the synergies between the
different channels and between the two experiments. On the other hand the lack
of knowledge of hierarchy and octant makes the CP sensitivity poorer for some
parameter ranges. Addition of ICAL data to T2K and NO$\nu$A can exclude these
spurious wrong-hierarchy and/or wrong-octant solutions and cause a significant
increase in the range of $\delta_{CP}$ values for which a hint of CP violation
can be achieved. In fact in parameter regions unfavourable for NO$\nu$A/T2K, we
may get the first evidence of CP violation by adding the ICAL data to these.
Similarly the precision with which $\delta_{CP}$ can be measured also improves
with inclusion of ICAL data.


title: $k$-reflexivity defect of the image of a generalized derivation

abstract:
  Let $\mathcal{X}$ be a finite-dimensional complex vector space and let k be a
positive integer. An explicit formula for the k-reflexivity defect of the image
of a generalized derivation on $L(\mathcal{X})$, the space of all linear
transformations on $\mathcal{X}$, is given. Using latter, we also study the
k-reflexivity defect of the image of an elementary operator of the form
$\Delta(T)=ATB-T$ $(T \in L(\mathcal{X}))$.


title: Modular perverse sheaves on flag varieties I: tilting and parity sheaves

abstract:
  In this paper we prove that the category of parity complexes on the flag
variety of a complex connected reductive group is a "graded version" of the
category of tilting perverse sheaves on the flag variety of the dual group, for
any field of coefficients whose characteristic is good. We derive some
consequences on Soergel's modular category O, and on multiplicities and
decomposition numbers in the category of perverse sheaves.


title: Quantifying resonant activation like phenomenon in non-Markovian systems

abstract:
  Resonant activation is an effect of a noise-induced escape over a modulated
potential barrier. The modulation of a energy landscape facilitates the escape
kinetics and makes it optimal as measured by the mean first passage time. A
canonical example of resonant activation is a Brownian particle moving in a
time-dependent potential under action of Gaussian white noise. Resonant
activation is observed not only in typical Markovian-Gaussian systems but also
in far from equilibrium and far from Markovianity regimes. We demonstrate that
using an alternative to the mean first passage time, robust measures of
resonant activation, the signature of this effect can be observed in general
continuous time random walks in modulated potentials even in situations when
the mean first passage time diverges.


title:
Quantum-limited shot noise and quantum interference in graphene based
  Corbino disk

abstract:
  This is a theoretical study of finite voltage effects on the conductance, the
shot noise power, and the third charge-transfer cumulant for graphene-based
Corbino disk in the presence of external magnetic fields. Periodic
magnetoconductance oscillations, predicted in Refs. [1,2], become invisible for
relatively small source-drain voltages, as the current decays rapidly with
magnetic field. Quantum interference still governs the behavior of higher
charge-transfer cumulants.


title: A large class of sofic monoids

abstract:
  We prove that a monoid is sofic, in the sense recently introduced by
Ceccherini-Silberstein and Coornaert, whenever the J-class of the identity is a
sofic group, and the quotients of this group by orbit stabilisers in the rest
of the monoid are amenable. In particular, this shows that the following are
all sofic: cancellative monoids with amenable group of units; monoids with
sofic group of units and finitely many non-units; and monoids with amenable
Schutzenberger groups and finitely many L-classes in each D-class. This
provides a very wide range of sofic monoids, subsuming most known examples
(with the notable exception of locally residually finite monoids). We conclude
by discussing some aspects of the definition, and posing some questions for
future research.


title: Fuzzy Controller Design for Assisted Omni-Directional Treadmill Therapy

abstract:
  One of the defining characteristic of human being is their ability to walk
upright. Loss or restriction of such ability whether due to the accident, spine
problem, stroke or other neurological injuries can cause tremendous stress on
the patients and hence will contribute negatively to their quality of life.
Modern research shows that physical exercise is very important for maintaining
physical fitness and adopting a healthier life style. In modern days treadmill
is widely used for physical exercises and training which enables the user to
set up an exercise regime that can be adhered to irrespective of the weather
conditions. Among the users of treadmills today are medical facilities such as
hospitals, rehabilitation centres, medical and physiotherapy clinics etc. The
process of assisted training or doing rehabilitation exercise through treadmill
is referred to as treadmill therapy. A modern treadmill is an automated machine
having built in functions and predefined features. Most of the treadmills used
today are one dimensional and user can only walk in one direction. This paper
presents the idea of using omnidirectional treadmills which will be more
appealing to the patients as they can walk in any direction, hence encouraging
them to do exercises more frequently. This paper proposes a fuzzy control
design and possible implementation strategy to assist patients in treadmill
therapy. By intelligently controlling the safety belt attached to the treadmill
user, one can help them steering left, right or in any direction. The use of
intelligent treadmill therapy can help patients to improve their walking
ability without being continuously supervised by the specialists. The patients
can walk freely within a limited space and the support system will provide
continuous evaluation of their position and can adjust the control parameters
of treadmill accordingly to provide best possible assistance.


title: Quantum quenches from excited states in the Ising chain

abstract:
  We consider the non-equilibrium dynamics after a sudden quench of the
magnetic field in the transverse field Ising chain starting from excited states
of the pre-quench Hamiltonian. We prove that stationary values of local
correlation functions can be described by the generalised Gibbs ensemble (GGE).
Then we study the full time evolution of the transverse magnetisation by means
of stationary phase methods. The equal time two-point longitudinal correlation
function is analytically derived for a particular class of excited states for
quenches within the ferromagnetic phase, and studied numerically in general.
The full time dependence of the entanglement entropy of a block of spins is
also obtained analytically for the same class of states and for arbitrary
quenches.


title: Transparency of Strong Gravitational Waves

abstract:
  This paper studies diagonal spacetime metrics. It is shown that the
overdetermined Einstein vacuum equations are compatible if one Killing vector
exists. The stability of plane gravitational waves of the Robinson type is
studied. This stability problem bares a fantastic mathematical resemblance to
the stability of the Schwarzschild black hole studied by Regge and Wheeler.
Just like for the Schwarzschild black hole, the Robinson gravitational waves
are proven to be stable with respect to small perturbations. We conjecture that
a bigger class of vacuum solutions are stable, among which are all
gravitational solitons. Moreover, the stability analysis reveals a surprising
fact: a wave barrier will be transparent to the Robinson waves, which therefore
passes through the barrier freely. This is a hint of integrability of the 1+2
vacuum Einstein equations for diagonal metrics.


title: Dynamical arrest: interplay of the glass and of the gel transitions

abstract:
  The structural arrest of a polymeric suspension might be driven by an
increase of the cross--linker concentration, that drives the gel transition, as
well as by an increase of the polymer density, that induces a glass transition.
These dynamical continuous (gel) and discontinuous (glass) transitions might
interfere, since the glass transition might occur within the gel phase, and the
gel transition might be induced in a polymer suspension with glassy features.
Here we study the interplay of these transitions by investigating via
event--driven molecular dynamics simulation the relaxation dynamics of a
polymeric suspension as a function of the cross--linker concentration and the
monomer volume fraction. We show that the slow dynamics within the gel phase is
characterized by a long sub-diffusive regime, which is due both to the crowding
as well as to the presence of a percolating cluster. In this regime, the
transition of structural arrest is found to occur either along the gel or along
the glass line, depending on the length scale at which the dynamics is probed.
Where the two line meet there is no apparent sign of higher order dynamical
singularity. Logarithmic behavior typical of $A_{3}$ singularity appear inside
the gel phase along the glass transition line. These findings seem to be
related to the results of the mode coupling theory for the $F_{13}$ schematic
model.


title: Nonlinear L\'evy Processes and their Characteristics

abstract:
  We develop a general construction for nonlinear L\'evy processes with given
characteristics. More precisely, given a set $\Theta$ of L\'evy triplets, we
construct a sublinear expectation on Skorohod space under which the canonical
process has stationary independent increments and a nonlinear generator
corresponding to the supremum of all generators of classical L\'evy processes
with triplets in $\Theta$. The nonlinear L\'evy process yields a tractable
model for Knightian uncertainty about the distribution of jumps for which
expectations of Markovian functionals can be calculated by means of a partial
integro-differential equation.


title: Some Negative Remarks on Operational Approaches to Quantum Theory

abstract:
  Over the last 10 years there has been an explosion of "operational
reconstructions" of quantum theory. This is great stuff: For, through it, we
come to see the myriad ways in which the quantum formalism can be chopped into
primitives and, through clever toil, brought back together to form a smooth
whole. An image comes to mind of a brain-teaser puzzle, all sliding and
interlocking pieces. There is no doubt that this is invaluable work,
particularly for our understanding of the intricate connections between so many
quantum information protocols. But to me, it seems to miss the mark for an
ultimate understanding of quantum theory; I am left hungry. I still want to
know what strange property of matter forces this formalism upon our information
accounting. To play on something Einstein once wrote to Max Born, "The quantum
reconstructions are certainly imposing. But an inner voice tells me that they
are not yet the real thing. The reconstructions say a lot, but do not really
bring us any closer to the secret of the `old one'." In this talk, I hope to
expand on these points and convey some sense of why I am fascinated with the
problem of the symmetric informationally complete POVMs to an extent greater
than axiomatic reconstructions.


title: The multi-marginal optimal partial transport problem

abstract:
  We introduce and study a multi-marginal optimal partial transport problem.
Under a natural and sharp condition on the dominating marginals, we establish
uniqueness of the optimal plan. Our strategy of proof establishes and exploits
a connection with another novel problem, which we call the Monge-Kantorovich
partial barycenter problem (with quadratic cost). This latter problem has a
natural interpretation as a variant of the mines and factories description of
optimal transport. We then turn our attention to various analytic properties of
these two problems. Of particular interest, we show that monotonicity of the
active marginals can fail, a surprising difference from the two marginal case.