title: On a Consequence of the Order Ideal Conjecture

abstract:
  Given a minimal set of generators $\bold{x}$ of an ideal $I$ of height d in a
regular local ring ($R, m, k$) we prove several cases for which the map
$K_d(\bold{x}; R) \otimes k \to \Tor_d^R (R/I, k)$ is the 0-map. As a
consequence of the order ideal conjecture we derive several cases for which
$K_{d+i}(\bold{x}; R) \otimes k \to \Tor_{d+i}^R (R/I, k)$ are 0-maps for $i
\ge 0$.


title:
Scaling of heat flux and energy spectrum for "very large" Prandtl number
  convection

abstract:
  Under the limit of infinite Prandtl number, we derive analytical expressions
for the large-scale quantities, e.g., P\'{e}clet number Pe, Nusselt number Nu,
and rms value of the temperature fluctuations $\theta_\mathrm{rms}$. We
complement the analytical work with direct numerical simulations, and show that
$\mathrm{Nu} \sim \mathrm{Ra}^{\gamma}$ with $\gamma \approx (0.30-0.32)$,
$\mathrm{Pe} \sim \mathrm{Ra}^{\eta}$ with $\eta \approx (0.57-0.61)$, and
$\theta_\mathrm{rms} \sim \mathrm{const}$. The Nusselt number is observed to be
an intricate function of $\mathrm{Pe}$, $\theta_\mathrm{rms}$, and a
correlation function between the vertical velocity and temperature. Using the
scaling of large-scale fields, we show that the energy spectrum $E_u(k)\sim
k^{-13/3}$, which is in a very good agreement with our numerical results. The
entropy spectrum $E_\theta(k)$ however exhibits dual branches consisting of
$k^{-2}$ and $k^0$ spectra; the $k^{-2}$ branch corresponds to the Fourier
modes $\hat{\theta}(0,0,2n)$, which are approximately $-1/(2n \pi)$. The
scaling relations for Prandtl number beyond $10^2$ match with those for
infinite Prandtl number.


title:
Equivalent Conditions on Periodic Feedback Stabilization for Linear
  Periodic Evolution Equations

abstract:
  This paper studies the periodic feedback stabilization for a class of linear
$T$-periodic evolution equations.Several equivalent conditions on the linear
periodic feedback stabilization are obtained. These conditions are related with
the following subjects: the attainable subspace of the controlled evolution
equation under consideration; the unstable subspace (of the evolution equation
with the null control) provided by the Kato projection; the Poincar$\acute{e}$
map associated with the evolution equation with the null control; and two
unique continuation properties for the dual equations on different time
horizons $[0,T]$ and $[0,n_0T]$ (where $n_0$ is the sum of algebraic
multiplicities of distinct unstable eigenvalues of the Poincar$\acute{e}$ map).
It is also proved that a $T$-periodic controlled evolution equation is linear
$T$-periodic feedback sabilizable if and only if it is linear $T$-periodic
feedback sabilizable with respect to a finite dimensional subspace. Some
applications to heat equations with time-periodic potentials are presented.


title:
Inclusive cross-sections for gluon production in collision of two
  projectiles on two targets in the BFKL approach

abstract:
  Inclusive cross-sections for gluon production in collision of two mucleons
with two nucleons are studied in the BFKL approach. Various contributions
include emission from the pomerons attached to the participants, from the BFKL
interactions in between these pomerons and from the intermediate BKP state. The
last contribution may be observable provided the growth with energy of the
pomeron contribution is tamed in accordance with unitarity.


title: Optimization of stochastic database cracking

abstract:
  Variant Stochastic cracking is a significantly more resilient approach to
adaptive indexing. It showed [1]that Stochastic cracking uses each query as a
hint on how to reorganize data, but not blindly so; it gains resilience and
avoids performance bottlenecks by deliberately applying certain arbitrary
choices in its decision making. Therefore bring, adaptive indexing forward to a
mature formulation that confers the workload-robustness that previous
approaches lacked. Original cracking relies on the randomness of the workloads
to converge well. [2][3] However, where the workload is non-random, cracking
needs to introduce randomness on its own. Stochastic Cracking clearly improves
over original cracking by being robust in workload changes while maintaining
all original cracking features when it comes to adaptation. But looking at both
types of cracking, it conveyed an incomplete picture as at some point of time
it is must to know whether the workload is random or sequential. In this paper
our focus is on optimization of variant stochastic cracking, that could be
achieved in two ways either by reducing the initialization cost to make
stochastic cracking even more transparent to the user, especially for queries
that initiate a workload change and hence incur a higher cost or by combining
the strengths of the various stochastic cracking algorithms via a dynamic
component that decides which algorithm to choose for a query on the fly. The
efforts have been put in to make an algorithm that reduces the initialization
cost by using the main notion of both cracking, while considering the
requirements of adaptive indexing [2].


title: Microscopic characterization of L\'evy flights of light in atomic vapors

abstract:
  We investigate multiple scattering of near-resonant light in a
Doppler-broadened atomic vapor. We experimentally characterize the length
distribution of the steps between successive scattering events. The obtained
power law is characteristic of a superdiffusive behavior, where rare but very
long steps (L\'evy flights) dominate the transport properties.


title:
Stationary solutions of Keller-Segel type crowd motion and herding
  models: multiplicity and dynamical stability

abstract:
  In this paper we study two models for crowd motion and herding. Each of the
models is of Keller-Segel type and involves two parabolic equations, one for
the evolution of the density and one for the evolution of a mean field
potential. We classify all radial stationary solutions, prove multiplicity
results and establish some qualitative properties of these solutions, which are
characterized as critical points of an energy functional. A notion of
variational stability is associated to such solutions. The dynamical stability
in a neighborhood of a stationary solution is also studied in terms of the
spectral properties of the linearized evolution operator. For one of the two
models, we exhibit a Lyapunov functional which allows to make the link between
the two notions of stability. Even in that case, for certain values of the mass
parameter and all other parameters taken in an appropriate range, we find that
two dynamically stable stationary solutions exist. We further discuss
qualitative properties of the solutions using theoretical methods and numerical
computations.


title: The Responses of Magnetically Sub-Critical Cores to Shocks

abstract:
  An ideal magnetohydrodynamics (MHD) code with adaptive mesh refinement (AMR)
was used to investigate the interactions of fast-mode shocks with
self-gravitating, isothermal cores with mass-to-flux ratios that are somewhat
below the minimum value required for gravitational collapse. We find that shock
focussing produces colliding flows along the field lines that generate very
high densities, even for relatively weak shocks. Self-gravity plays only a
minor role in determining the highest density that is reached, but it does play
a role in the subsequent evolution. The densities at comparable times differ by
a factor of a few for shocks initially propagating perpendicularly or obliquely
to the magnetic field in the ambient medium.


title: The effect of planet-planet scattering on the survival of exomoons

abstract:
  Compared to the giant planets in the solar system, exoplanets have many
remarkable properties such as the prevalence of giant planets on eccentric
orbits and the presence of hot Jupiters. Planet-planet scattering (PPS) between
giant planets is a possible mechanism in interpreting above and other observed
properties. If the observed giant planet architectures are indeed the outcomes
of PPS, such drastic dynamical process must affect their primordial moon
systems. In this Letter, we discuss the effect of the PPS on the survival of
their regular moons. From the viewpoint of observations, some preliminary
conclusions are drawn from the simulations. 1. PPS is a destructive process to
the moon systems, single planets on eccentric orbits are not the ideal
moon-search targets. 2. If hot Jupiters formed through PPS, their original
moons have little chance to survive. 3. Planets in multiple systems with small
eccentricities are more likely holding their primordial moons. 4. Compared to
the lower-mass planets, the massive ones in multiple systems may not be the
preferred moon-search targets if the system underwent a PPS history.


title:
Baseline drift effect on the performance of neutron and gamma ray
  discrimination using frequency gradient analysis

abstract:
  Frequency gradient analysis (FGA) effectively discriminates neutrons and
gamma rays by examining the frequency-domain features of the photomultiplier
tube anode signal. This approach is insensitive to noise but is inevitably
affected by the baseline drift, similar to other pulse shape discrimination
methods. The baseline drift effect is attributed to the factors such as power
line fluctuation, dark current, noise disturbances, hum, and pulse tail in
front-end electronics. This effect needs to be elucidated and quantified before
the baseline shift can be estimated and removed from the captured signal.
Therefore, the effect of baseline shift on the discrimination performance of
neutrons and gamma rays with organic scintillation detectors using FGA is
investigated in this paper. The relationship between the baseline shift and
discrimination parameters of FGA is derived and verified by an experimental
system consisting of an americium-beryllium source, a BC501A liquid
scintillator detector, and a 5 GSPS 8-bit oscilloscope. Both theoretical and
experimental results show that the estimation of the baseline shift is
necessary, and the removal of baseline drift from the pulse shapes can improve
the discrimination performance of FGA.


title:
Local cohomology with support in ideals of maximal minors and
  sub-maximal Pfaffians

abstract:
  We compute the GL-equivariant description of the local cohomology modules
with support in the ideal of maximal minors of a generic matrix, as well as of
those with support in the ideal of 2n x 2n Pfaffians of a (2n+1)x(2n+1) generic
skew-symmetric matrix. As an application, we characterize the Cohen-Macaulay
modules of covariants for the action of the special linear group SL(G) on G^m.
The main tool we develop is a method for computing certain Ext modules based on
the geometric technique for computing syzygies and on Matlis duality.


title: Trace functions with applications in quantum physics

abstract:
  We consider both known and not previously studied trace functions with
applications in quantum physics. By using perspectives we obtain convexity
statements for different notions of residual entropy, including the entropy
gain of a quantum channel as studied by Holevo and others.
  We give new and simplified proofs of the Carlen-Lieb theorems concerning
concavity or convexity of certain trace functions by making use of the theory
of operator monotone functions. We then apply these methods in a study of new
types of trace functions.
  Keywords: Trace function, convexity, entropy gain, residual entropy, operator
monotone function.


title: Noisy continuous time random walks

abstract:
  Experimental studies of the diffusion of biomolecules in the environment of
biological cells are routinely confronted with multiple sources of
stochasticity, whose identification renders the detailed data analysis of
single molecule trajectories quite intricate. Here we consider subdiffusive
continuous time random walks, that represent a seminal model for the anomalous
diffusion of tracer particles in complex environments. This motion is
characterized by multiple trapping events with infinite mean sojourn time. In
real physical situations, however, instead of the full immobilization predicted
by the continuous time random walk model, the motion of the tracer particle
shows additional jiggling, for instance, due to thermal agitation of the
environment. We here present and analyze in detail an extension of the
continuous time random walk model. Superimposing the multiple trapping behavior
with additive Gaussian noise of variable strength, we demonstrate that the
resulting process exhibits a rich variety of apparent dynamic regimes. In
particular, such noisy continuous time random walks may appear ergodic while
the naked continuous time random walk exhibits weak ergodicity breaking.
Detailed knowledge of this behavior will be useful for the truthful physical
analysis of experimentally observed subdiffusion.


title:
One-dimensional quantum walks via generating function and the CGMV
  method

abstract:
  We treat a quantum walk (QW) on the line whose quantum coin at each vertex
tends to be the identity as the distance goes to infinity. We obtain a limit
theorem that this QW exhibits localization with not an exponential but a
"power-law" decay around the origin and a "strongly" ballistic spreading called
bottom localization in this paper. This limit theorem implies the weak
convergence with linear scaling whose density has two delta measures at $x=0$
(the origin) and $x=1$ (the bottom) without continuous parts.


title:
Asymptotics of linear waves and resonances with applications to black
  holes

abstract:
  We apply the results of arXiv:1301.5633 to describe asymptotic behavior of
linear waves on stationary Lorentzian metrics with r-normally hyperbolic
trapped sets, in particular Kerr and Kerr-de Sitter metrics with |a|<M and
M\Lambda a << 1. We prove that if the initial data is localized at frequencies
\lambda >> 1, then the energy norm of the solution is bounded by
O(\lambda^{1/2} exp(-(\nu_min - \epsilon)t/2) + \lambda^(-\infty)), for t < C
log\lambda, where \nu_min is a natural dynamical quantity. The key tool is a
microlocal projector splitting the solution into a component with controlled
rate of exponential decay and an O(\lambda exp(-(\nu_min -\epsilon)t) +
\lambda^(-\infty)) remainder; this splitting can be viewed as an analog of
resonance expansion. Moreover, for the Kerr-de Sitter case we study
quasi-normal modes; under a dynamical pinching condition, a Weyl law in a band
holds.


title:
Evidence for nuclear gluon shadowing from the ALICE measurements of PbPb
  ultraperipheral exclusive J/{\psi} production

abstract:
  We show that the recent ALICE measurements of exclusive J/{\psi} production
in ultraperipheral PbPb collisions at 2.76 TeV provide the first direct
experimental evidence for the strong nuclear gluon shadowing in lead at $x \sim
10^{-3}$. The evidence is based on the comparison of the nuclear suppression
factor S(x\approx 0.001)=0.61^{+0.05}_{-0.04} found in the analysis of the
coherent J/{\psi} photoproduction cross sections measured by ALICE with the
nuclear gluon shadowing predicted by the global fits of nuclear parton
distributions and by the leading twist theory of nuclear shadowing.


title: Experimental study of 199Hg spin anti-relaxation coatings

abstract:
  We report on a comparison of spin relaxation rates in a $^{199}$Hg
magnetometer using different wall coatings. A compact mercury magnetometer was
built for this purpose. Glass cells coated with fluorinated materials show
longer spin coherence times than if coated with their hydrogenated homologues.
The longest spin relaxation time of the mercury vapor was measured with a
fluorinated paraffin wall coating.


title:
On differences between the border rank and the smoothable rank of a
  polynomial

abstract:
  We consider higher secant varieties to Veronese varieties. Most points on the
r-th secant variety are represented by a finite scheme of length r contained in
the Veronese variety --- in fact, for generic point, it is just a union of r
distinct points. A modern way to phrase it is: the smoothable rank is equal to
the border rank for most polynomials. This property is very useful for studying
secant varieties, especially, whenever the smoothable rank is equal to the
border rank for all points of the secant variety in question. In this note we
investigate those special points for which the smoothable rank is not equal to
the border rank. In particular, we show an explicit example of a cubic in five
variables with border rank 5 and smoothable rank 6. We also prove that all
cubics in at most four variables have the smoothable rank equal to the border
rank.


title:
On attribute-based usage control policy ratification for cooperative
  computing context

abstract:
  In an open information systems paradigm, real-time context-awareness is vital
for the success of cooperation, therefore dynamic security attributes of
partners should considered in coalition for avoiding security conflicts.
Furthermore, the cross-boundary asset sharing activities and risks associated
to loss of governance call for a continuous regulation of partners' behavior,
paying attention to the resource sharing and consuming activities. This paper
describes an attribute-based usage control policy shceme compline to this
needs. A concise syntax with EBNF is used to summarize the base policy model.
The semantics of negotiation process is disambiguated with abductive constraint
logic programming (ACLP) and Event Calculus (EC). Then we propose a policy
ratification method based on a policy aggregation algebra that elaborate the
request space and policy rule relation. This method ensures that, when policies
are aggregated due to resource sharing and merging activities, the resulting
policy correctly interprets the original security goals of the providers'
policies.


title: Finiteness of classes of relative equilibria for the $n$-body problem

abstract:
  We prove that if the masses of the $n$-body problem of celestial mechanics
are given, the number of classes of relative equilibria that solve the $n$-body
problem is finite.


title:
A Simple Technique for the Converse of Finite Blocklength Multiple
  Access Channels

abstract:
  A converse for the Discrete Memoryless Multiple Access Channel is given. The
result in [13] is refined, and the third order term is obtained. Moreover, our
proof is much simpler than [13]. With little modification, the region can be
further improved.


title: The Redundancy of Slepian-Wolf Coding Revisited

abstract:
  [Draft] In this paper, the redundancy of Slepian Wolf coding is revisited.
Applying the random binning and converse technique in \cite{yang}, the same
results in \cite{he} are obtained with much simpler proofs. Moreover, our
results reflect more details about the high-order terms of the coding rate. The
redundancy is investigated for both fixed-rate and variable-rate cases. The
normal approximation (or dispersion) can also be obtained with minor
modification.


title:
Mapping the Central Region of the PPN CRL 618 at Sub-arcsecond
  Resolution at 350 GHz

abstract:
  CRL 618 is a well-studied pre-planetary nebula. We have mapped its central
region in continuum and molecular lines with the Submillimeter Array at 350 GHz
at ~ 0.3" to 0.5" resolutions. Two components are seen in 350 GHz continuum:
(1) a compact emission at the center tracing the dense inner part of the H II
region previously detected in 23 GHz continuum and it may trace a fast ionized
wind at the base, and (2) an extended thermal dust emission surrounding the H
II region, tracing the dense core previously detected in HC3N at the center of
the circumstellar envelope. The dense core is dusty and may contain mm-sized
dust grains. It may have a density enhancement in the equatorial plane. It is
also detected in carbon chain molecules HC3N and HCN, and their isotopologues,
with higher excitation lines tracing closer to the central star. It is also
detected in C2H3CN toward the innermost part. Most of the emission detected
here arises within ~ 630 AU (~0.7") from the central star. A simple radiative
transfer model is used to derive the kinematics, physical conditions, and the
chemical abundances in the dense core. The dense core is expanding and
accelerating, with the velocity increasing roughly linearly from ~ 3 km/s in
the innermost part to ~ 16 km/s at 630 AU. The mass-loss rate in the dense core
is extremely high with a value of ~ 1.15x10^{-3} solar mass per year. The dense
core has a mass of ~ 0.47 solar mass and a dynamical age of ~ 400 yrs. It could
result from a recent enhanced heavy mass-loss episode that ends the AGB phase.
The isotopic ratios of 12C/13C and 14N/15N are 9$\pm$4 and 150$\pm50$,
respectively, both lower than the solar values.


title:
Tuning the electronic properties of J_eff=1/2 correlated semimetal in
  epitaxial perovskite SrIrO3

abstract:
  We investigated the electronic properties of epitaxially stabilized
perovskite SrIrO3 and demonstrated the effective strain-control on its
electronic structure. Comprehensive transport measurements showed that the
strong spin-orbit coupling renders a novel semimetallic phase for the J_eff=1/2
electrons rather than an ordinary correlated metal, elucidating the nontrivial
mechanism underlying the dimensionality-controlled metal-insulator transition
in iridates. The electron-hole symmetry of this correlated semimetal was found
to exhibit drastic variation when subject to bi-axial strain. Under compressive
strain, substantial electron-hole asymmetry is observed in contrast to the
tensile side, where the electron and hole effective masses are comparable,
illustrating the susceptivity of the J_eff=1/2 to structural distortion.
Tensile strain also shrinks the Fermi surface, indicative of an increasing
degree of correlation which is consistent with optical measurements. These
results pave a pathway to investigate and manipulate the electronic states in
spin-orbit-coupled correlated oxides, and lay the foundation for constructing
5d transition metal heterostructures.


title: Curves of Generalized AW(k)-type in Euclidean Spaces

abstract:
  In this study, we consider curves of generalized AW(k)-type of Euclidean
n-space. We give curvature conditions of these kind of curves.


title:
When Politicians Tweet: A Study on the Members of the German Federal
  Diet

abstract:
  In this preliminary study we compare the characteristics of retweets and
replies on more than 350,000 messages collected by following members of the
German Federal Diet on Twitter. We find significant differences in the
characteristics pointing to distinct types of usages for retweets and replies.
Using time series and regression analysis we observe that the likelihood of a
politician using replies increases with typical leisure times while retweets
occur constant over time. Including formal references increases the probability
of a message being retweeted but drops its chance of being replied. This hints
to a more professional use for retweets while replies tend to have a personal
connotation.


title: Permutation complexity of interacting dynamical systems

abstract:
  The coupling complexity index is an information measure introduced within the
framework of ordinal symbolic dynamics. This index is used to characterize the
complexity of the relationship between dynamical system components. In this
work, we clarify the meaning of the coupling complexity by discussing in detail
some cases leading to extreme values, and present examples using synthetic data
to describe its properties. We also generalize the coupling complexity index to
the multivariate case and derive a number of important properties by exploiting
the structure of the symmetric group. The applicability of this index to the
multivariate case is demonstrated with a real-world data example. Finally, we
define the coupling complexity rate of random and deterministic time series.
Some formal results about the multivariate coupling complexity index have been
collected in an Appendix.


title:
Global dynamical correlation energies in covariant density functional
  theory: cranking approximation

abstract:
  The global dynamical correlation energies for 575 even-even nuclei with
proton numbers ranging from Z=8 to Z=108 calculated with the covariant density
functional theory using the PC-PK1 parametrization are presented. The dynamical
correlation energies include the rotational correction energies obtained with
the cranking approximation and the quadrupole vibrational correction energies.
The systematic behavior of the present correlation energies is in good
agreement with that obtained from the projected generator coordinate method
using the SLy4 Skyrme force although our values are systematically smaller.
After including the dynamical correlation energies, the root-mean-square
deviation predicted by the PC-PK1 for the 575 even-even nuclei masses is
reduced from 2.58 MeV to 1.24 MeV.


title: MC-curves and aesthetic measurements for pseudospiral curve segments

abstract:
  This article studies families of curves with monotonic curvature function
(MC-curves) and their applications in geometric modelling and aesthetic design.
Aesthetic analysis and assessment of the structure and plastic qualities of
pseudospirals, which are curves with monotonic curvature function, are
conducted for the first time in the field of geometric modelling from the
position of technical aesthetics laws. The example of car body surface
modelling with the use of aesthetics splines is given.


title: Spins, Electromagnetic Moments, and Isomers of 107-129Cd

abstract:
  The neutron-rich isotopes of cadmium up to the N=82 shell closure have been
investigated by high-resolution laser spectroscopy. Deep-UV excitation at 214.5
nm and radioactive-beam bunching provided the required experimental
sensitivity. Long-lived isomers are observed in 127Cd and 129Cd for the first
time. One essential feature of the spherical shell model is unambiguously
confirmed by a linear increase of the 11/2- quadrupole moments. Remarkably,
this mechanism is found to act well beyond the h11/2 shell.


title:
Determination of structures in the space-time from local measurements: a
  detailed exposition

abstract:
  We consider inverse problems for the Einstein equation with a time-depending
metric on a 4-dimensional globally hyperbolic Lorentzian manifold $(M,g)$. We
formulate the concept of active measurements for relativistic models. We do
this by coupling the Einstein equation with equations for scalar fields and
study the system $Ein(g)=T$, $T=T(g,\phi)+F_1$, and $\square_g
\phi=F_2+S(g,\phi,F_1,F_2)$. Here $F=(F_1,F_2)$ correspond to the perturbations
of the physical fields which we control and $S$ is a secondary source
corresponding to the adaptation of the system to the perturbation so that the
conservation law $div_g(T)=0$ will be satisfied.
  The inverse problem we study is the question, do the observation of the
solutions $(g,\phi)$ in an open subset $U\subset M$ of the space-time
corresponding to sources $F$ supported in $U$ determine the properties of the
metric in a larger domain $W\subset M$ containing $U$. To study this problem we
define the concept of light observation sets and show that these sets determine
the conformal class of the metric. This corresponds to passive observations
from a distant area of the space which is filled by light sources (e.g. we see
light from stars varying in time). One can apply the obtained result to solve
inverse problems encountered in general relativity and in various practical
imaging problems.


title: Radio pulsars: the search for truth

abstract:
  It was as early as the 1980s that A V Gurevich and his group proposed a
theory to explain the magnetosphere of radio pulsars and the mechanism by which
they produce coherent radio emission. The theory has been sharply criticized
and is currently rarely mentioned when discussing the observational properties
of radio pulsars, even though all the criticisms were in their time disproven
in a most thorough and detailed manner. Recent results show even more
conclusively that the theory has no internal inconsistencies. New observational
data also demonstrate the validity of the basic conclusions of the theory.
Based on the latest results on the effects of wave propagation in the
magnetosphere of a neuron star, we show that the developed theory does indeed
allow quantitative predictions of the evolution of neutron stars and the
properties of the observed radio emission.


title:
On the multiple hyperbolic systems modeling phase transformation
  kinetics

abstract:
  We discuss Cahn's time cone method modeling phase transformation kinetics.
The model equation by the time cone method is an integral equation in the
space-time region. First we reduce it to a system of hyperbolic equations, and
in the case of odd spatial dimensions, the reduced system is a multiple
hyperbolic equation. Next we propose a numerical method for such a hyperbolic
system. By means of alternating direction implicit methods, numerical
simulations for practical forward problems are implemented with satisfactory
accuracy and efficiency. In particular, in the three dimensional case, our
numerical method on basis of reduced multiple hyperbolic equation, is fast.


abstract:
  The Kuramoto model constitutes a paradigmatic model for the dissipative
collective dynamics of coupled oscillators, characterizing in particular the
emergence of synchrony. Here we present a classical Hamiltonian (and thus
conservative) system with 2N state variables that in its action-angle
representation exactly yields Kuramoto dynamics on N-dimensional invariant
manifolds. We show that the synchronization transition on a Kuramoto manifold
emerges where the transverse Hamiltonian action dynamics becomes unstable. The
uncovered Kuramoto dynamics in Hamiltonian systems thus distinctly links
dissipative to conservative dynamics.


title:
Grand-Canonical Quantized Liquid Density-Functional Theory in a
  Car-Parrinello Implementation

abstract:
  Quantized Liquid Density-Functional Theory [Phys. Rev. E 2009, 80, 031603], a
method developed to assess the adsorption of gas molecules in porous
nanomaterials, is reformulated within the grand canonical ensemble. With the
grand potential it is possible to compare directly external and internal
thermodynamic quantities. In our new implementation, the grand potential is
minimized utilizing the Car-Parrinello approach and gives, in particular for
low temperature simulations, a significant computational advantage over the
original canonical approaches. The method is validated against original QLDFT,
and applied to model potentials and graphite slit pores.


title: Suffix Tree of Alignment: An Efficient Index for Similar Data

abstract:
  We consider an index data structure for similar strings. The generalized
suffix tree can be a solution for this. The generalized suffix tree of two
strings $A$ and $B$ is a compacted trie representing all suffixes in $A$ and
$B$. It has $|A|+|B|$ leaves and can be constructed in $O(|A|+|B|)$ time.
However, if the two strings are similar, the generalized suffix tree is not
efficient because it does not exploit the similarity which is usually
represented as an alignment of $A$ and $B$.
  In this paper we propose a space/time-efficient suffix tree of alignment
which wisely exploits the similarity in an alignment. Our suffix tree for an
alignment of $A$ and $B$ has $|A| + l_d + l_1$ leaves where $l_d$ is the sum of
the lengths of all parts of $B$ different from $A$ and $l_1$ is the sum of the
lengths of some common parts of $A$ and $B$. We did not compromise the pattern
search to reduce the space. Our suffix tree can be searched for a pattern $P$
in $O(|P|+occ)$ time where $occ$ is the number of occurrences of $P$ in $A$ and
$B$. We also present an efficient algorithm to construct the suffix tree of
alignment. When the suffix tree is constructed from scratch, the algorithm
requires $O(|A| + l_d + l_1 + l_2)$ time where $l_2$ is the sum of the lengths
of other common substrings of $A$ and $B$. When the suffix tree of $A$ is
already given, it requires $O(l_d + l_1 + l_2)$ time.


title: Mobile Recommender Systems Methods: An Overview

abstract:
  The information that mobiles can access becomes very wide nowadays, and the
user is faced with a dilemma: there is an unlimited pool of information
available to him but he is unable to find the exact information he is looking
for. This is why the current research aims to design Recommender Systems (RS)
able to continually send information that matches the user's interests in order
to reduce his navigation time. In this paper, we treat the different approaches
to recommend.


title:
Structured $H_\infty$-Optimal Control for Nested Interconnections: A
  State-Space Solution

abstract:
  If imposing general structural constraints on controllers, it is unknown how
to design $H_\infty$-controllers by convex optimization. Under a so-called
quadratic invariance structure of the generalized plant, the Youla
parametrization allows to translate the structured synthesis problem into an
infinite-dimensional convex program. Nested interconnections that are
characterized by a standard plant with a block-triangular structure fall into
this class. Recently it has been shown how to design optimal $H_2$-controllers
for such nested structures in the state-space by solving algebraic Riccati
equations. In the present paper we provide a state-space solution of the
corresponding output-feedback $H_\infty$ synthesis problem without any
counterpart in the literature. We argue that a solution based on Riccati
equations is - even for state-feedback problems - not feasible and we
illustrate our results by means of a simple numerical example.


title: Optimal dividend problem for a generalized compound Poisson risk model

abstract:
  In this note we study the optimal dividend problem for a company whose
surplus process, in the absence of dividend payments, evolves as a generalized
compound Poisson model in which the counting process is a generalized Poisson
process. This model including the classical risk model and the Polya-Aeppli
risk model as special cases. The objective is to find a dividend policy so as
to maximize the expected discounted value of dividends which are paid to the
shareholders until the company is ruined. We show that under some conditions
the optimal dividend strategy is formed by a barrier strategy.


title: On the (co)homology of Frobenius Poisson algebras

abstract:
  In this paper, we study the Poisson (co)homology of a Frobenius Poisson
algebra. More precisely, we show that there exists a duality between the
Poisson homology and the Poisson cohomology, similar to the duality between the
Hochschild homology and the Hochschild cohomology of a Frobenius algebra. Using
the non-degenerated bilinear form on a Frobenius algebra we construct a
Batalin-Vilkovisky structure on the Poisson cohomology ring of a class of
Frobenius Poisson algebras.


title: The generator and quantum Markov semigroup for quantum walks

abstract:
  The quantum walks in the lattice spaces are represented as unitary
evolutions. We find a generator for the evolution and apply it to further
understand the walks. We first extend the discrete time quantum walks to
continuous time walks. Then we construct the quantum Markov semigroup for
quantum walks and characterize it in an invariant subalgebra. In the meanwhile,
we obtain the limit distributions of the quantum walks in one-dimension with a
proper scaling, which was obtained by Konno by a different method.


title: Quantum transition-edge detectors

abstract:
  Small perturbations to systems near critical points of quantum phase
transitions can induce drastic changes in the system properties. Here I show
that this sensitivity can be exploited for weak-signal detection applications.
This is done by relating a widely studied signature of quantum chaos and
quantum phase transitions known as the Loschmidt echo to the minimum error
probability for a quantum detector and noting that the echo, and therefore the
error, can be significantly reduced near a critical point. Three examples,
namely, the quantum Ising model, the optical parametric oscillator model, and
the Dicke model, are presented to illustrate the concept. For the latter two
examples, the detectable perturbation can exhibit a Heisenberg scaling with
respect to the number of detectors, even though the detectors are not entangled
and no special quantum state preparation is specified.


title:
Inference and testing for structural change in time series of counts
  model

abstract:
  We consider here together the inference questions and the change-point
problem in Poisson autoregressions (see Tj{\o}stheim, 2012). The conditional
mean (or intensity) of the process is involved as a non-linear function of it
past values and the past observations. Under Lipschitz-type conditions, it is
shown that the conditional mean can be written as a function of lagged
observations. In the latter model, assume that the link function depends on an
unknown parameter $\theta_0$. The consistency and the asymptotic normality of
the maximum likelihood estimator of the parameter are proved. These results are
used to study change-point problem in the parameter $\theta_0$. We propose two
tests based on the likelihood of the observations. Under the null hypothesis
(i.e. no change), it is proved that both those test statistics converge to an
explicit distribution. Consistencies under alternatives are proved for both
tests. Simulation results show how those procedure work practically, and an
application to real data is also processed.


title:
Relation spaces of hyperplane arrangements and modules defined by graphs
  of fiber zonotopes

abstract:
  We study the exactness of certain combinatorially defined complexes which
generalize the Orlik-Solomon algebra of a geometric lattice. The main results
pertain to complex reflection arrangements and their restrictions. In
particular, we consider the corresponding relation complexes and give a simple
proof of the $n$-formality of these hyperplane arrangements. As an application,
we are able to bound the Castelnouvo-Mumford regularity of certain modules over
polynomial rings associated to Coxeter arrangements (real reflection
arrangements) and their restrictions. The modules in question are defined using
the relation complex of the Coxeter arrangement and fiber polytopes of the dual
Coxeter zonotope. They generalize the algebra of piecewise polynomial functions
on the original arrangement.


title: Fractional Gamma process and fractional Gamma-subordinated processes

abstract:
  We define and study fractional versions of the well-known Gamma subordinator
$\Gamma :=\{\Gamma (t),$ $t\geq 0\},$ which are obtained by time-changing $%
\Gamma $ by means of an independent stable subordinator or its inverse. Their
densities are proved to satisfy differential equations expressed in terms of
fractional versions of the shift operator (with fractional parameter greater or
less than one, in the two cases). As a consequence, the fractional
generalization of some Gamma subordinated processes (i.e. the Variance Gamma,
the Geometric Stable and the Negative Binomial) are introduced and the
corresponding fractional differential equations are obtained.


title: Two Higgs doublet models at future colliders

abstract:
  The two Higgs doublet model (THDM) is a simple extension of the standard
model, which can provide a low energy effective description of more fundamental
theories. The model contains additional Higgs bosons, and predicts rich
phenomenology especially due to the variation of Yukawa interactions. Under
imposing a softly broken discrete symmetry, there are four independent types of
Yukawa interactions in THDMs. In this review, we briefly summarize bounds from
current experimental data on THDMs and implications at future collider
experiments. We pay special attention to the collider phenomenology of the
Type-X (lepton specific) THDM, and also discuss recent progress for $\tan\beta$
determination in THDMs.


title: Nucleosynthesis in the accretion disks of Type II collapsars

abstract:
  We investigate nucleosynthesis inside the gamma-ray burst (GRB) accretion
disks formed by the Type II collapsars. In these collapsars, the core collapse
of massive stars first leads to the formation of a proto-neutron star and a
mild supernova explosion is driven. However, this supernova ejecta lack
momentum and falls back onto the neutron star which gets transformed to a
stellar mass black hole. In order to study the hydrodynamics and
nucleosynthesis of such an accretion disk formed from the fallback material of
the supernova ejecta, we use the well established hydrodynamic models. In such
a disk neutrino cooling becomes important in the inner disk where the
temperature and density are higher. Higher the accretion rate (dot{M}), higher
is the density and temperature in the disks. In this work we deal with
accretion disks with relatively low accretion rates: 0.001 M_sun s^{-1}
\lesssim dot{M} \lesssim 0.01 M_sun s^{-1} and hence these disks are
predominantly advection dominated. We use He-rich and Si-rich abundances as the
initial condition of nucleosynthesis at the outer disk, and being equipped with
the disk hydrodynamics and the nuclear network code, we study the abundance
evolution as matter inflows and falls into the central object. We investigate
the variation in the nucleosynthesis products in the disk with the change in
the initial abundance at the outer disk and also with the change in the mass
accretion rate. We report the synthesis of several unusual nuclei like {31}P,
{39}K, {43}Sc, {35}Cl, and various isotopes of titanium, vanadium, chromium,
manganese and copper. We also confirm that isotopes of iron, cobalt, nickel,
argon, calcium, sulphur and silicon get synthesized in the disk, as shown by
previous authors. Much of these heavy elements thus synthesized are ejected
from the disk via outflows and hence they should leave their signature in
observed data.


title:
Minimal state space realization, static output feedback and matrix
  completion of families of systems

abstract:
  We here characterize the minimality of realization of arbitrary linear
time-invariant dynamical systems through (i) intersection of the spectra of the
realization matrix and of the corresponding state submatrix and (ii) moving the
poles by applying static output feedback. In passing, we introduce, for a given
square matrix A, a parameterization of all matrices B for which the pairs (A,
B) are controllable. In particular, the minimal rank of such B turns to be
equal to the smallest geometric multiplicity among the eigenvalues of A.
Finally, we show that the use of a (not necessarily square) realization matrix
L to examine minimality of realization, is equivalent to the study of a smaller
dimensions, square realization matrix L_sq, which in turn is linked to
realization matrices obtained as polynomials in L_sq. Namely a whole family of
systems.


title: Baryonic Isgur-Wise Functions in Large $N_c$ HQET

abstract:
  Large N_c relations among baryonic Isgur-Wise functions appearing at the
order of 1/m_Q are analyzed. An application to \Omega_b \to \Omega_c weak
decays is given.


title: Hitting probabilities for general Gaussian processes

abstract:
  For a scalar Gaussian process $B$ on $\mathbb{R}_{+}$ with a prescribed
general variance function $\gamma^{2}\left(r\right)
=\mathrm{Var}\left(B\left(r\right) \right) $ and a canonical metric
$\mathrm{E}[\left(B\left(t\right) -B\left(s\right) \right) ^{2}]$ which is
commensurate with $\gamma^{2}\left(t-s\right) $, we estimate the probability
for a vector of $d$ iid copies of $B$ to hit a bounded set $A$ in
$\mathbb{R}^{d}$, with conditions on $\gamma$ which place no restrictions of
power type or of approximate self-similarity, assuming only that $\gamma$ is
continuous, increasing, and concave, with $\gamma\left(0\right) =0$ and
$\gamma^{\prime}\left(0+\right) =+\infty$. We identify optimal base (kernel)
functions which depend explicitly on $\gamma$, to derive upper and lower bounds
on the hitting probability in terms of the corresponding generalized Hausdorff
measure and non-Newtonian capacity of $A$ respectively. The proofs borrow and
extend some recent progress for hitting probabilities estimation, including the
notion of two-point local-nondeterminism in Bierm\'{e}, Lacaux, and Xiao
\cite{Bierme:09}.


title:
Implicit-Explicit Runge-Kutta schemes for the Boltzmann-Poisson system
  for semiconductors

abstract:
  In this paper we develop a class of Implicit-Explicit Runge-Kutta schemes for
solving the multi-scale semiconductor Boltzmann equation. The relevant scale
which characterizes this kind of problems is the diffusive scaling. This means
that, in the limit of zero mean free path, the system is governed by a
drift-diffusion equation. Our aim is to develop a method which accurately works
for the different regimes encountered in general semiconductor simulations: the
kinetic, the intermediate and the diffusive one. Moreover, we want to overcome
the restrictive time step conditions of standard time integration techniques
when applied to the solution of this kind of phenomena without any
deterioration in the accuracy. As a result, we obtain high order time and space
discretization schemes which do not suffer from the usual parabolic stiffness
in the diffusive limit. We show different numerical results which permit to
appreciate the performances of the proposed schemes.


title:
Investigation on the Coronal Magnetic Field Using a Type II Solar Radio
  Burst

abstract:
  The Type-II solar radio burst recorded on 13 June 2010 by the radio
spectrograph of the Hiraiso Solar Observatory was employed to estimate the
magnetic-field strength in the solar corona. The burst was characterized by a
well pronounced band-splitting, which we used to estimate the density jump at
the shock and Alfven Mach number using the Rankine-Hugoniot relations. The
plasma frequency of the Type-II bursts is converted into height [R] in solar
radii using the appropriate density model, then we estimated the shock speed
[Vs], coronal Alfven velocity [Va], and the magnetic-field strength at
different heights. The relative bandwidth of the band-split is found to be in
the range 0.2 -- 0.25, corresponding to the density jump of X = 1.44 -- 1.56,
and the Alfven Mach number of MA = 1.35 -- 1.45. The inferred mean shock speed
was on the order of V ~ 667 km/s. From the dependencies V(R) and MA(R) we found
that Alfven speed slightly decreases at R ~ 1.3 -- 1.5. The magnetic-field
strength decreases from a value between 2.7 and 1.7 G at R ~ 1.3 -- 1.5 Rs
depending on the coronal-density model employed. We find that our results are
in good agreement with the empirical scaling by Dulk and McLean (Solar Phys.
57, 279, 1978) and Gopalswamy et al. (Astrophys. J. 744, 72, 2012). Our result
shows that Type-II band splitting method is an important tool for inferring the
coronal magnetic field, especially when independent measurements were made from
white light observations.


title:
The Thouless theorem for matrix product states and subsequent
  post-density matrix renormalization group methods

abstract:
  The similarities between Hartree-Fock (HF) theory and the density-matrix
renormalization group (DMRG) are explored. Both methods can be formulated as
the variational optimization of a wave-function ansatz. Linearization of the
time-dependent variational principle near a variational minimum allows to
derive the random phase approximation (RPA). We show that the non-redundant
parametrization of the matrix product state (MPS) tangent space [J. Haegeman et
al., Phys. Rev. Lett. 107, 070601 (2011)] leads to the Thouless theorem for
MPS, i.e. an explicit non-redundant parametrization of the entire MPS manifold,
starting from a specific MPS reference. Excitation operators are identified,
which extends the analogy between HF and DMRG to the Tamm-Dancoff approximation
(TDA), the configuration interaction (CI) expansion, and coupled cluster
theory. For a small one-dimensional Hubbard chain, we use a CI-MPS ansatz with
single and double excitations to improve on the ground state and to calculate
low-lying excitation energies. For a symmetry-broken ground state of this
model, we show that RPA-MPS allows to retrieve the Goldstone mode. We also
discuss calculations of the RPA-MPS correlation energy. With the long-range
quantum chemical Pariser-Parr-Pople Hamiltonian, low-lying TDA-MPS and RPA-MPS
excitation energies for polyenes are obtained.


title: New Bounds on the Capacity of Fiber-Optics Communications

abstract:
  By taking advantage of the temporal correlations of the nonlinear phase noise
in WDM systems we show that the capacity of a nonlinear fiber link is notably
higher than what is currently assumed. This advantage is translated into the
doubling of the link distance for a fixed transmission rate.


title:
The photospheric solar oxygen project: II. Non-concordance of the oxygen
  abundance derived from two forbidden lines

abstract:
  In the Sun, the two forbidden [OI] lines at 630 and 636 nm were previously
found to provide discrepant oxygen abundances. aims: We investigate whether
this discrepancy is peculiar to the Sun or whether it is also observed in other
stars. method: We make use of high-resolution, high signal-to-noise ratio
spectra of four dwarf to turn-off stars, five giant stars, and one sub-giant
star observed with THEMIS, HARPS, and UVES to investigate the coherence of the
two lines. results: The two lines provide oxygen abundances that are
consistent, within observational errors, in all the giant stars examined by us.
On the other hand, for the two dwarf stars for which a measurement was
possible, for Procyon, and for the sub-giant star Capella, the 636 nm line
provides systematically higher oxygen abundances, as already seen for the Sun.
conclusions: The only two possible reasons for the discrepancy are a serious
error in the oscillator strength of the NiI line blending the 630 nm line or
the presence of an unknown blend in the 636 nm line, which makes the feature
stronger. The CN lines blending the 636 nm line cannot be responsible for the
discrepancy. The CaI autoionisation line, on the red wing of which the 636 nm
line is formed, is not well modelled by our synthetic spectra. However, a
better reproduction of this line would result in even higher abundances from
the 636 nm, thus increasing the discrepancy.


title:
The study of s-process nucleosynthesis based on barium stars, CEMP-s and
  CEMP-r/s stars

abstract:
  In order to get a broader view of the s-process nucleosynthesis we study the
abundance distribution of heavy elements of 35 barium stars and 24 CEMP-stars,
including nine CEMP-s stars and 15 CEMP-r/s stars. The similar distribution of
[Pb/hs] between CEMP-s and CEMP-r/s stars indicate that the s-process material
of both CEMP-s and CEMP-r/s stars should have a uniform origin, i.e. mass
transfer from their predominant AGB companions. For the CEMP-r/s stars, we
found that the r-process should provide similar proportional contributes to the
second s-peak and the third s-peak elements, and also be responsible for the
higher overabundance of heavy elements than those in CEMP-s stars. Which hints
that the r-process origin of CEMP-r/s stars should be closely linked to the
main r-process. The fact that some small $r$ values exist for both barium and
CEMP-s stars, implies that the single exposure event of the s-process
nucleosynthesis should be general in a wide metallicity range of our Galaxy.
Based on the relation between $C_{r}$ and $C_{s}$, we suggest that the origin
of r-elements for CEMP-r/s stars have more sources. A common scenario is that
the formation of the binary system was triggered by only one or a few
supernova. In addition, accretion-induced collapse(AIC) or SN 1.5 should be the
supplementary scenario, especially for these whose pre-AGB companion with
higher mass and smaller orbit radius, which support the higher values of both
$C_{r}$ and $C_{s}$.


title:
Phase structure of a generalized Nambu Jona-Lasinio model with Wilson
  fermions in the mean field or large $N$-expansion

abstract:
  We analyze the vacuum structure of a generalized lattice Nambu--Jona-Lasinio
model with two flavors of Wilson fermions, such that its continuum action is
the most general four-fermion action with 'trivial' color interactions, and
having a $SU(2)_V x SU(2)_A$ symmetry in the chiral limit. The phase structure
of this model in the space of the two four-fermion couplings shows, in addition
to the standard Aoki phases, new phases with $<\bar\psi \gamma_5\psi> != 0$, in
close analogy to similar results recently suggested by some of us for lattice
QCD with two degenerate Wilson fermions. This result shows how the phase
structure of an effective model for low energy QCD cannot be entirely
understood from Wilson Chiral Perturbation Theory, based on the standard QCD
chiral effective Lagrangian approach.


title: Google In A Photonic Lattice

abstract:
  The quantum version of Google PageRank has recently been investigated by
various groups and shown to be quadratically faster in time than the classical
PageRank algorithm. In this paper we propose the implementation of Quantum
PageRank by a stochastic quantum walk of correlated photons in a photonic
waveguide lattice, where we allow the density matrix to evolve according to the
Lindblad-Kossakowski master equation. This yields a stationary state, the
diagonal of whose density matrix gives the page ranking.


title: Negativity and steering: a stronger Peres conjecture

abstract:
  The violation of a Bell inequality certifies the presence of entanglement
even if neither party trusts their measurement devices. Recently Moroder et.
al. showed how to make this statement quantitative, using semidefinite
programming to calculate how much entanglement is certified by a given
violation. Here I adapt their techniques to the case where Bob's measurement
devices are in fact trusted, the setting for "EPR-steering" inequalities.
Interestingly, all of the steering inequalities studied turn out to require
negativity for their violation. This supports a significant strengthening of
Peres' conjecture that negativity is required to violate a bipartite Bell
inequality.


title:
Entanglement as an indicator of a geometrical crossover in a
  two-electron quantum dot in a magnetic field

abstract:
  We found that a downwardly concave entanglement evolution of the ground state
of a two-electron axially symmetric quantum dot testifies that a shape
transition from a lateral to a vertical localization of two electrons under a
perpendicular magnetic field takes place. Although affected, the two-electron
probability density does not exhibit any prominent change.


title:
The LHC excess of four-lepton events interpreted as Higgs-boson signal:
  background from Double Drell--Yan process?

abstract:
  We construct a simple model of the Double Drell--Yan Process (DDYP) for
proton--proton collisions and investigate its possible contribution to the
background for the Higgs-boson searches at the LHC. We demonstrate that under
the assumption of the predominance of short range, ${\cal O}(0.1)\,$fm,
transverse-plane correlations of quark--antiquark pairs within the proton this
contribution becomes important and may even explain the observed excess of the
four-lepton events at the LHC -- the events interpreted as originating from the
Higgs-boson decays: $ H \rightarrow ZZ^{*} \rightarrow 4l$ and $ H \rightarrow
WW^{*} \rightarrow 2l 2 \nu$.


title:
Topological Surface States in Paramagnetic and Antiferromagnetic Iron
  Pnictides

abstract:
  The electronic structure of iron pnictides is topologically nontrivial,
leading to the appearance of Dirac cones in the band structure for the
antiferromagnetic phase. Motivated by the analogy with Dirac cones in graphene,
we explore the possible existence of topologically protected surface states.
Surprisingly, bands of surface states exist even in the paramagnetic state. A
realistic five-orbital model predicts two such bands. In the antiferromagnetic
phase, these surface bands survive but split. We obtain the bulk and surface
dispersion from exact diagonalization of two- and five-orbital models in a
strip geometry and discuss the results based on topology.


title: Trace class operators, regulators, and assembly maps in K-theory

abstract:
  Let G be a group, Fin the family of its finite subgroups, and E(G,Fin) the
classifying space. Let L^1 be the algebra of trace-class operators in an
infinite dimensional, separable Hilbert space over the complex numbers.
Consider the rational assembly map in homotopy algebraic K-theory
H_p^G(E(G,Fin),KH(L^1))\otimes\Q \to KH_p(L^1[G])\otimes\Q. The rational
KH-isomorphism conjecture predicts that the map above is an isomorphism; it
follows from a theorem of Yu (see arXiv:1106.3796, arXiv:1202.4999) that it is
always injective. In the current article we prove the following. Theorem:
Assume that the map above is surjective. Let n\equiv p+1\mod 2. Then: i) The
assembly map for the trivial family H_n^G(E(G,{1}),K(\Z)) \to K_n(\Z[G]) is
rationally injective. ii) For every number field F, the assembly map
H_n^G(E(G,Fin),K(F)) \to K_n(F[G]) is rationally injective. We remark that the
K-theory Novikov conjecture asserts that part i) of the theorem above holds for
all G, and that part ii) is equivalent to the rational injectivity part of the
K-theory Farrell-Jones conjecture for number fields. The idea of the proof of
the Theorem is to use an algebraic, equivariant version of Karoubi's
multiplicative K-theory, which we introduce in this article.


title:
A fully quantum mechanical calculation of the diffusivity of hydrogen in
  iron using the tight binding approximation and path integral theory

abstract:
  We present calculations of free energy barriers and diffusivities as
functions of temperature for the diffusion of hydrogen in bcc-Fe. This is a
fully quantum mechanical approach since the total energy landscape is computed
using a new self consistent, transferable tight binding model for interstitial
impurities in magnetic iron. Also the hydrogen nucleus is treated quantum
mechanically and we compare here two approaches in the literature both based in
the Feynman path integral formulation of statistical mechanics. We find that
the quantum transition state theory which admits greater freedom for the proton
to explore phase space gives result in better agreement with experiment than
the alternative which is based on fixed centroid calculations of the free
energy barrier. We also find results in better agreement compared to recent
centroid molecular dynamics (CMD) calculations of the diffusivity which
employed a classical interatomic potential rather than our quantum mechanical
tight binding theory. In particular we find first that quantum effects persist
to higher temperatures than previously thought, and conversely that the low
temperature diffusivity is smaller than predicted in CMD calculations and
larger than predicted by classical transition state theory. This will have
impact on future modeling and simulation of hydrogen trapping and diffusion.


title:
Sensitivity Enhancement of (Hyper-)CEST Image Series by Exploiting
  Redundancies in the Spectral Domain

abstract:
  CEST has proven to be a valuable technique for the detection of
hyperpolarized xenon-based functionalized contrast agents. Additional
information can be encoded in the spectral dimension, allowing the simultaneous
detection of multiple different biosensors. However, due to the low
concentration of dissolved xenon in biological tissue, the signal to noise
ratio (SNR) of Hyper-CEST data is still a critical issue. In this work, we
present two techniques aiming to increase SNR by exploiting the typically high
redundancy in spectral CEST image series: PCA-based post-processing and
sub-sampled acquisition with low-rank reconstruction. Each of them yields a
significant SNR enhancement, demonstrating the feasibility of the two
approaches. While the first method is directly applicable to proton CEST
experiments as well, the second one is particularly beneficial when dealing
with hyperpolarized nuclei, since it distributes the non-renewable initial
polarization more efficiently over the sampling points. The results obtained
are a further step towards the detection of xenon biosensors with spectral
Hyper-CEST imaging in vivo.


title:
Atomic diffusion and mixing in old stars IV: Weak abundance trends in
  the globular cluster NGC 6752

abstract:
  Atomic diffusion in stars can create systematic trends of surface abundances
with evolutionary stage. Globular clusters offer useful laboratories to put
observational constraints on this theory as one needs to compare abundances in
unevolved and evolved stars, all drawn from the same stellar population. In
this paper, we show the results of an abundance study of stars in the globular
cluster NGC6752 which shows weak but systematic abundances trends with
evolutionary phase for Fe, Sc, Ti and Ca. The trends are best explained by a
stellar structure model including atomic diffusion with efficient additional
mixing. The model allows to correct for sub-primordial stellar lithium
abundances of the stars on the Spite plateau, and to match it to the
WMAP-calibrated Big-Bang nucleosynthesis predictions to within the mutual
1-sigma errors.


title: Analytical aspects of isospectral drums

abstract:
  We reexamine the proofs of isospectrality of the counterexample domains to
Kac' question `Can one hear the shape of a drum?' from an analytical viewpoint.
We reformulate isospectrality in a more abstract setting as the existence of a
similarity transform intertwining two operators associated with elliptic forms,
and give several equivalent characterizations of this property as intertwining
the forms and form domains, the associated operators and operator domains, and
the semigroups they generate. On a representative pair of counterexample
domains, we use these criteria to show that the similarity transform
intertwines not only the Laplacians with Neumann (or Dirichlet) boundary
conditions but also any two appropriately defined elliptic operators on these
domains, even if they are not self-adjoint. However, no such transform can
intertwine these operators if Robin boundary conditions are imposed instead of
Neumann or Dirichlet. We also remark on various operator-theoretic properties
of such intertwining similarity transforms.


title:
The Rosenfeld-Tarazona expression for liquids' specific heat: A
  numerical investigation of eighteen systems

abstract:
  We investigate the accuracy of the expression of Rosenfeld and Tarazona (RT)
for the excess isochoric heat capacity, C_V^{ex} \propto T^{-2/5}, for eighteen
model liquids. Previous investigations have reported no unifying features of
breakdown for the RT expression. Here liquids with different stoichiometric
composition, molecular topology, chemical interactions, degree of undercooling,
and environment are investigated. We find that the RT expression is a better
approximation for liquids with strong correlations between equilibrium
fluctuations of virial and potential energy, i.e., Roskilde simple liquids
[Ingebrigtsen et al., Phys. Rev. X 2, 011011 (2012)]. This observation holds
even for molecular liquids under severe nanoscale confinement, the physics of
which is completely different from the original RT bulk hard-sphere fluid
arguments. The density dependence of the specific heat is predicted from the
isomorph theory for Roskilde simple liquids, which in combination with the RT
expression provides a complete description of the specific heat's density and
temperature dependence.


title: Homotopy theory of smooth compactifications of algebraic varieties

abstract:
  In this short note we show that the homotopy category of smooth
compactifications of smooth algebraic varieties is equivalent to the homotopy
category of smooth varieties over a field of characteristic zero. As an
application we show that the functor sending a variety to the p-th step of the
Hodge filtration of its complex cohomology is representable in the homotopy
category of simplicial presheaves on smooth complex varieties. The main
motivation are recent applications of homotopy theory to Deligne-Beilinson
cohomology theories.


title:
A General Family of Estimators for Estimating Population Mean in
  Systematic Sampling Using Auxiliary Information in the Presence of Missing
  Observations

abstract:
  This paper proposes a general family of estimators for estimating the
population mean in systematic sampling in the presence of non-response adapting
the family of estimators proposed by Khoshnevisan et al. (2007). In this paper
we have discussed the general properties of the proposed family including
optimum property. The results have been illustrated numerically by taking an
empirical population considered in the literature.


title: States of motion in an AC liquid film motor: experiments and theory

abstract:
  The liquid film motor (LFM) is a simple device which serves as a laboratory
to conduct experimental research in basic theoretical studies of
electrohydrodynamics (EHD). In addition the LFM can play an important role in
technological applications such as micro mixers and washers. In this paper we
initially performed experiments to examine the theory regarding rotation and
vibration of an AC LFM. While many theoretical predictions are in agreement
with our experimental data, but in the threshold of vibration there is an
obvious disagreement; we showed that no threshold exists and oscillation is
observed in any field value. Experimental evidence showed the existence of an
elastic deformation in water before reaching the yield stress and lead us to
the use of the elastic Bingham fluid model. We revised the theories using this
model and investigated the behaviour of a vibrating LFM which has more
applications in mixing. We applied a numerical solution to derive different
phases of vibration and distinguish between elastic and plastic vibrations, the
latter which could be used for mixing.


title: Screening and gap generation in bilayer graphene

abstract:
  A fully selfconsistent treatment for gap generation and Coulomb screening in
excitonic insulators is presented. The method is based on the equations of
motion for the relevant dynamical variables combined with a variational
approach. Applying the theory for a model system of bilayer graphene, an
excitonic groundstate with a gap exceeding 10 meV is predicted.


title: Photodissociation of interstellar N2

abstract:
  Molecular nitrogen is one of the key species in the chemistry of interstellar
clouds and protoplanetary disks and the partitioning of nitrogen between N and
N2 controls the formation of more complex prebiotic nitrogen-containing
species. The aim of this work is to gain a better understanding of the
interstellar N2 photodissociation processes based on recent detailed
theoretical and experimental work and to provide accurate rates for use in
chemical models.
  We simulated the full high-resolution line-by-line absorption + dissociation
spectrum of N2 over the relevant 912-1000 \AA\ wavelength range, by using a
quantum-mechanical model which solves the coupled-channels Schr\"odinger
equation. The simulated N2 spectra were compared with the absorption spectra of
H2, H, CO, and dust to compute photodissociation rates in various radiation
fields and shielding functions. The effects of the new rates in interstellar
cloud models were illustrated for diffuse and translucent clouds, a dense
photon dominated region and a protoplanetary disk.


title: Search for Baryonic Decays of \psi(3770) and \psi(4040)

abstract:
  By analyzing data samples of 2.9 fb^{-1} collected at \sqrt s=3.773 GeV, 482
pb^{-1} collected at \sqrt s=4.009 GeV and 67 pb^{-1} collected at \sqrt
s=3.542, 3.554, 3.561, 3.600 and 3.650 GeV with the BESIII detector at the
BEPCII storage ring, we search for \psi(3770) and \psi(4040) decay to baryonic
final states, including \Lambda\bar\Lambda\pi^+\pi^-, \Lambda \bar\Lambda\pi^0,
\Lambda\bar\Lambda\eta, \Sigma^+ \bar\Sigma^-, \Sigma^0 \bar\Sigma^0,
\Xi^-\bar\Xi^+ and \Xi^0\bar\Xi^0 decays. None are observed, and upper limits
are set at the 90% confidence level.


title:
Improving Diffusion-Based Molecular Communication with Unanchored
  Enzymes

abstract:
  In this paper, we propose adding enzymes to the propagation environment of a
diffusive molecular communication system as a strategy for mitigating
intersymbol interference. The enzymes form reaction intermediates with
information molecules and then degrade them so that they have a smaller chance
of interfering with future transmissions. We present the reaction-diffusion
dynamics of this proposed system and derive a lower bound expression for the
expected number of molecules observed at the receiver. We justify a
particle-based simulation framework, and present simulation results that show
both the accuracy of our expression and the potential for enzymes to improve
communication performance.


title: Emergent Potentials in Consistent Higher Derivative N=1 Supergravity

abstract:
  By employing consistent supersymmetric higher derivative terms, we show that
the supersymmetric theories may have a sector where the scalar potential does
no longer have the conventional form.
  The theories under consideration contain consistent higher-derivative terms
which do not give rise to instabilities and ghost states. The chiral
auxiliaries are still not propagating and can be integrated out. Their
elimination gives rise to emerging potentials even when there is not a
superpotential to start with. This novel feature of higher derivative
supersymmetric chiral models is also extended to vector multiplets both in
global and local supersymmetry. In particular, in supergravity, the emerging
potentials give rise always to a de Sitter vacuum signaling supersymmetry
breaking.


title:
Surface plasmon-polariton resonance at diffraction of THz radiation on
  semiconductor gratings

abstract:
  Resonance diffraction of THz HCN laser radiation on a semiconductor (InSb)
grating is studied both experimentally and theoretically. The specular
reflectivity suppression due to the resonance excitation of the THz surface
plasmon-polariton is observed on a pure semiconductor grating and on
semiconductor gratings covered with a thin striped layer of the residual
photoresist. Presence of a thin dielectric layer on the grating surface leads
to the shift and widening of the plasmon-polariton resonance. A simple
analytical theory of the resonance diffraction on a shallow grating covered
with a dielectric layer is presented. Its results are in a good accordance with
the experimental data. Analytical expressions for the resonance shift and
broadening can be useful for sensing data interpretation.


title:
Quantized Iterative Hard Thresholding: Bridging 1-bit and
  High-Resolution Quantized Compressed Sensing

abstract:
  In this work, we show that reconstructing a sparse signal from quantized
compressive measurement can be achieved in an unified formalism whatever the
(scalar) quantization resolution, i.e., from 1-bit to high resolution
assumption. This is achieved by generalizing the iterative hard thresholding
(IHT) algorithm and its binary variant (BIHT) introduced in previous works to
enforce the consistency of the reconstructed signal with respect to the
quantization model. The performance of this algorithm, simply called quantized
IHT (QIHT), is evaluated in comparison with other approaches (e.g., IHT, basis
pursuit denoise) for several quantization scenarios.


title: Evolution of the user's content: An Overview of the state of the art

abstract:
  The evolution of the user's content still remains a problem for an accurate
recommendation.This is why the current research aims to design Recommender
Systems (RS) able to continually adapt information that matches the user's
interests. This paper aims to explain this problematic point in outlining the
proposals that have been made in research with their advantages and
disadvantages.


title:
Interaction effects on almost flat surface bands in topological
  insulators

abstract:
  We consider ferromagnetic instabilities of two-dimensional helical Dirac
fermions hosted on the surface of three-dimensional topological insulators. We
investigate ways to increase the role of interactions by means of modifying the
bulk properties which in turn changes both the surface Dirac theory and the
screening of interactions. We discuss both the long-ranged part of the Coulomb
interactions controlled by the dimensionless coupling constant $\alpha =
e^{2}/(\hbar \epsilon v_{F}^{\mathrm{surf}})$ as well as the effects of local
interactions parametrized by the ratio $U_{\mathrm{surf}}/D_{\mathrm{surf}}$ of
a local interaction on the surface, $U_{\mathrm{surf}}$, and the surface
bandwidth, $D_{\mathrm{surf}}$. If large compared to 1, both mechanisms can
induce spontaneously surface ferromagnetism, thereby gapping the surface Dirac
metal and inducing an anomalous quantum Hall effect. We investigate two
mechanisms which can naturally lead to small Fermi velocities
$v_{F}^{\mathrm{surf}}$ and a corresponding small bandwidth $D_{\mathrm{surf}}$
at the surface when the bulk band gap is reduced. The same mechanisms can,
however, also lead to an enhanced screening of surface interactions. While in
all considered cases the long-ranged part of the Coulomb interaction is
screened efficiently, $\alpha \lesssim 1$, we discuss situations, where
$U_{\mathrm{surf}}/D_{\mathrm{surf}}$ becomes \emph{parametrically}\ large
compared to 1, thus inducing surface magnetism.


title: Second-order gravitational self-force -- a quick summary

abstract:
  In order to extract physical parameters from the waveform of an
extreme-mass-ratio binary, one requires a second-order--accurate description of
the motion of the smaller of the two objects in the binary. Using a method of
matched asymptotic expansions, I derive the second-order equation of motion of
a small, nearly spherical and non-rotating compact object in an arbitrary
vacuum spacetime. I find that the motion is geodesic in a certain locally
defined effective metric satisfying the vacuum Einstein equation through second
order, and I outline a method of numerically calculating this effective metric.


title:
Can the electronic energy spectra of bulk excitonic states be traced to
  parent molecular states in fluorene and its hetero-analogues? It depends on
  the mutual orientation of the respective transition dipoles in the crystal

abstract:
  The effect of intermolecular interactions on intensity redistribution between
individual electronic transitions in different polymorphs of fluorene and
dibenzofuran was studied by transmittance electronic spectroscopy in the energy
range from onset of absorption to the ionization energy (from ~4.0 eV to ~9.0
eV - Electronic transitions with transition dipoles at oblique angles to the
crystallographic axes (A1 symmetry) in these crystals resemble molecular
spectra. Transitions of B2 symmetry, which in these crystals have parallel
transition dipoles, resemble molecular spectra for surface (substrate
influenced) states. For bulk excitonic states the spectra of these transitions
have a continuous, uniform intensity distribution in the whole energy range
investigated, except for the case when the B2 transition is the onset of
absorption.


title:
Magnetic Exchange Coupling and Anisotropy of 3d Transition-Metal
  Nanowire on the Surface of Graphyne Sheet

abstract:
  Using density functional theory plus Hubbard-U (DFT+U) approach, we find that
quasi one-dementation(1D) 3d transition metal(TM) zigzag nanowire can be
constructed by TM adsorbed on the surface of graphyne sheet. The results show
that the TM exchange coupling of the zigzag nanowire mediated by sp hybridized
carbon atoms gives rise to long range ferromagnetic order except for Cr with
anti-ferromagnetic order. The magnetic exchange interaction of TM chains
follows like-Zener's p_z-d exchange mechanism: the coexistence of out-of plane
p_z-d and in-plane p_x-y-d exchange. Finally, by including spin-orbit
interactions within spin-DFT, we calculate the magnetic anisotropy energy of
the TM chain on graphyne. We find that the Fe and Co chains show considerable
magnetic anisotropy energy (MAE) and orbital magnetic moment. The easy axis of
V, Cr, Mn and Fe chains is perpendicular to the surface, whereas the easy axis
of Co lies in the surface. Moreover, only V chain shows relatively larger
in-plane anisotropy. Our results open a new route to realize the applications
of graphyne in spintronics.


title: Reflection Positivity for Majoranas

abstract:
  We establish reflection positivity for Gibbs trace states defined by a
certain class of Hamiltonians that describe the interaction of Majoranas on a
lattice. These Hamiltonians may include many-body interactions, as long as the
signs of the associated coupling constants satisfy certain restrictions. We
show that reflection positivity holds on an even subalgebra of Majoranas.

categories: math-ph cond-mat.mes-hall hep-th math.MP quant-ph


title: Optical non-reciprocity of cold atom Bragg mirrors in motion

abstract:
  Reciprocity is fundamental to light transport and is a concept that holds
also in rather complex systems. Yet, reciprocity can be switched off even in
linear, isotropic and passive media by setting the material structure into
motion. In highly dispersive multilayers this leads to a fairly large
forward-backward asymmetry in the pulse transmission. Moreover, in multilevel
systems, this transport phenomenon can be all-optically enhanced. For atomic
multilayer structures made of three-level cold Rubidium 87 atoms, for instance,
forward-backward transmission contrast around 95 per cent can be obtained
already at atomic speeds in the meter per second range. The scheme we
illustrate may open up avenues for optical isolation that were not previously
accessible.


title: On a theorem by Juh\'asz and Szentmikl\'ossy

abstract:
  We extend a theorem by Juh\'asz and Szentmikl\'ossy to notions related to
pseudocompactness. We also allow the case when one of the cardinals under
consideration is singular.
  We give an application to the study of decomposable ultrafilters: if \kappa\
is singular, D is a uniform ultrafilter over \kappa ^+, and D' is a uniform
ultrafilter over cf \kappa, then D' \times D is \kappa-decomposable.


title:
Mesoscale simulation of semiflexible chains. II. Evolution dynamics and
  stability of fiber bundle networks

abstract:
  Network formation of associative semiflexible fibers and mixtures of fibers
and colloidal particles is simulated for the Johnson-Kendall-Roberts (JKR)
model of elastic contacts, and a phase diagram in terms of particle elasticity
and surface energy is presented. When fibers self-assemble they form a network
for sufficiently large fiber-solvent surface energy. If the surface energy is
above the value where single particles crystallize the adhesion forces drive
diffusion-limited aggregation. Two mechanisms contribute to coarsening:
non-associated chains joining existing bundles, and fiber bundles merging.
Coarsening stops when the length of the network connections is roughly the
persistence length, independent of surface energy.
  If the surface energy is below the value where single particles crystallize,
a network can still be formed but at a much slower (reaction limited) rate.
Loose (liquid-like) assemblies between chains form when they happen to run
more-or-less parallel. These assemblies grow by diffusion and aggregation and
form a loose network, which sets in micro-phase separation, i.e. syneresis.
Only when the clusters crystallize, the coarsening process stops. In this case
the length of the network connections is larger than the persistence length of
a single chain, and depends on the value of the surface energy. All networks of
semiflexible homopolymers in this study show syneresis. Mixtures of fibers and
colloid particles also form fiber bundle networks, but by choosing the colloid
volume fraction sufficiently low, swelling gels are obtained. Applications of
this model are in biological systems where fibers self-assemble into cell walls
and bone tissue.


title:
Using Dimensional Analysis to Assess Scalability and Accuracy in
  Molecular Communication

abstract:
  In this paper, we apply dimensional analysis to study a diffusive molecular
communication system that uses diffusing enzymes in the propagation environment
to mitigate intersymbol interference. The enzymes bind to information molecules
and then degrade them so that they cannot interfere with the detection of
future transmissions at the receiver. We determine when it is accurate to
assume that the concentration of information molecules throughout the receiver
is constant and equal to that expected at the center of the receiver. We show
that a lower bound on the expected number of molecules observed at the receiver
can be arbitrarily scaled over the environmental parameters, and generalize how
the accuracy of the lower bound is qualitatively impacted by those parameters.


title:
Elliptic flow and nuclear modification factors of D-mesons at FAIR in a
  Hybrid-Langevin approach

abstract:
  The Compressed Baryonic Matter (CBM) experiment at the Facility for
Anti-proton and Ion Research (FAIR) will provide new possibilities for
charm-quark ($D$-meson) observables in heavy-ion collisions at low collision
energies and high baryon densities. To predict the collective flow and nuclear
modification factors of charm quarks in this environment, we apply a Langevin
approach for the transport of charm quarks in the UrQMD (hydrodynamics +
Boltzmann) hybrid model. Due to the inclusion of event-by-event fluctuations
and a full (3+1) dimensional hydrodynamical evolution, the UrQMD hybrid
approach provides a realistic evolution of the matter produced in heavy-ion
collisions.
  As drag and diffusion coefficients we use a resonance approach for elastic
heavy-quark scattering and assume a decoupling temperature of the charm quarks
from the hot medium of $130\, \MeV$. Hadronization of the charm quarks to
$D$-mesons by coalescence is included. Since the initial charm-quark
distribution at FAIR is unknown, we utilize two different initial charm-quark
distributions in our approach to estimate the uncertainty of these predictions.
We present calculations of the nuclear modification factor, $R_{AA}$, as well
as for the elliptic flow, $v_2$, in Pb+Pb collisions at
$E_{lab}=25\,\text{AGeV}$. The different medium modifications of $D$-mesons and
$\bar{D}$-mesons at high baryon-chemical potential are explored by modified
drag- and diffusion-coefficients using the corresponding fugacity factor. Here
we find a considerably larger medium modification for $\bar{\mathrm{D}}$- than
for $D$-mesons.


title: Highly symmetric fundamental domains for lattices in R^2 and R^3

abstract:
  It is shown that most lattices $\Gamma$ in $\mathbb{R}^2$ and $\mathbb{R}^3$
possess a fundamental domain $F$ for the action of $\Gamma$ on $\mathbb{R}^2$,
respectively $\mathbb{R}^3$, having more symmetries than the point group
$P(\Gamma)$, i.e., the group $P (\Gamma) \subset O(d)$ fixing $\Gamma$. In
particular, $P (\Gamma)$ is a subgroup of the symmetry group $S(F)$ of $F$ of
index 2 in these cases. Exceptions are cubic lattices in the three-dimensional
case, where such an $F$ does not exist. Possible exceptions are rhombic
lattices in the plane case, where the constructions presented here do not seem
to work.


title:
Mesoscale simulation of semiflexible chains. I. Endpoint distribution
  and chain dynamics

abstract:
  The endpoint distribution and dynamics of semiflexible fibers is studied by
numerical simulation. A brief overview is given over the analytical theory of
flexible and semiflexible polymers. In particular, a closed expression is given
for the relaxation spectrum of wormlike chains, which determines polymer
diffusion and rheology. Next a simulation model for wormlike chains with full
hydrodynamic interaction is described, and relations for the bending and
torsion modulus are given. Two methods are introduced to include torsion
stiffness into the model. The model is validated by simulating single chains in
a heat bath, and comparing the endpoint distribution of the chains with
established Monte Carlo results. It is concluded that torsion stiffness leads
to a slightly shorter effective persistence length for a given bending
stiffness. To further validate the simulation model, polymer diffusion is
studied for fixed persistence length and varying polymer length N. The
diffusion constant shows crossover from Rouse to reptation behaviour. The
terminal relaxation time obtained from the monomer displacement is consistent
with the theory of wormlike chains. The probability for chain crossing has also
been studied. This probability is so low that it does not influence the present
results.


title: Phase Space Crystals: A New Way to Create a Quasienergy Band Structure

abstract:
  A novel way to create a band structure of the quasienergy spectrum for driven
systems is proposed based on the discrete symmetry in phase space. The system,
e.g., an ion or ultracold atom trapped in a potential, shows no spatial
periodicity, but it is driven by a time-dependent field coupling highly
nonlinearly to one of its degrees of freedom (e.g., ~ q^n). The band structure
in quasienergy arises as a consequence of the n-fold discrete periodicity in
phase space induced by this driving field. We propose an explicit model to
realize such a phase space crystal and analyze its band structure in the frame
of a tight-binding approximation. The phase space crystal opens new ways to
engineer energy band structures, with the added advantage that its properties
can be changed in situ by tuning the driving field's parameters.


title:
The very energetic, broad-lined type Ic Supernova 2010ah (PTF10bzf) in
  the context of GRB/SNe

abstract:
  SN2010ah, a very broad-lined type Ic SN discovered by the Palomar Transient
Factory, was interesting because of its relatively high luminosity and the high
velocity of the absorption lines, which was comparable to that of GRB/SNe,
suggesting a high explosion kinetic energy. However, no GRB was detected in
association with the SN. Here, the properties of SN2010ah are determined with
higher accuracy than previous studies through modelling. New Subaru telescope
photometry is presented. A bolometric light curve is constructed taking
advantage of the spectral similarity with SN1998bw. Radiation transport tools
are used to reproduce the spectra and the light curve. The results thus
obtained regarding ejecta mass, composition and kinetic energy are then used to
compute a synthetic light curve. This is in reasonable agreement with the early
bolometric light curve of SN2010ah, but a high abundance of 56Ni at high
velocity is required to reproduce the early rise, while a dense inner core must
be used to reproduce the slow decline at late phases. The high-velocity 56Ni
cannot have been located on our line of sight, which may be indirect evidence
for an off-axis, aspherical explosion. The main properties of SN2010ah are:
ejected mass ~ 3 Mo; kinetic energy ~10^52 erg, M(56Ni) ~ 0.25 Mo. The mass
located at v >~ 0.1c is ~0.2 Mo. Although these values, in particular the
kinetic energy, are quite large for a SN Ic, they are all smaller (especially
the ejecta mass) than those typical of GRB/SNe. This confirms the tendency for
these quantities to correlate, and suggests that there are minimum requirements
for a GRB/SN, which SN2010ah may not meet although it comes quite close.
Depending on whether a neutron star or a black hole was formed following core
collapse, SN2010ah was the explosion of a CO core of ~ 5-6 Mo, pointing to a
progenitor mass of ~24 - 28 Mo.


title: The Central 3 kpc of NGC 5850

abstract:
  NGC 5850 is a nearby (z=0.0085) early type spiral galaxy classified as LINER.
It is considered as a prototype double-barred system. Our optical Integral
Field Spectroscopic (IFS) data of the central 21x19 arcsec^2 of NGC 5850 show
extended LINER-like emission which we ascribe to the presence of a hot and
evolved stellar population, possibly together with a faint AGN. Additionally
NGC 5850 shows extended `composite' ionization patterns, likely to stem from a
mixture of LINER-like ionization and photoionization by star formation. The
kinematics of the gas deviates strongly from a simple rotational structure.


title: Stacked reverberation lags at high redshift

abstract:
  Over the past 20years reverberation mapping has proved one of the most
successful techniques for studying the local (<1pc) environment of
super-massive black holes that drive active galactic nuclei. Key successes of
reverberation mapping have been direct black hole mass estimates, the
radius-luminosity relation for the Hbeta line and the calibration of
single-epoch mass estimators commonly employed up to z~7. However, observing
constraints mean that few studies have been successful at z>0.1, or for the
more-luminous quasars that make up the majority of current spectroscopic
samples, or for the rest-frame ultra-violet emission lines available in optical
spectra of z>0.5 objects.
  Previously we described a technique for stacking cross correlations to obtain
reverberation mapping results at high z. Here we present the first results from
a campaign designed for this purpose. We construct stacked cross-correlation
functions for the CIV and MgII lines and find a clear peak in both. We find the
peak in the MgII correlation is at longer lags than CIV consistent with
previous results at low redshift. For the CIV sample we are able to bin by
luminosity and find evidence for increasing lags for more-luminous objects.
This CIV radius-luminosity relation is consistent with previous studies but
with a fraction of the observational cost.


title: Soliton dynamics for fractional Schrodinger equations

abstract:
  We investigate the soliton dynamics for the fractional nonlinear Schrodinger
equation by a suitable modulational inequality. In the semiclassical limit, the
solution concentrates along a trajectory determined by a Newtonian equation
depending of the fractional diffusion parameter.


title:
The solution to the challenge in "Time-Reversible Random Number
  Generators" by Wm. G. Hoover and Carol G. Hoover

abstract:
  I provide the algorithm that solves the challenge proposed by Wm. G. Hoover
and Carol G. Hoover in their recent paper "Time-Reversible Random Number
Generators", arXiv:1305.0961, with an explanation on how to derive it
analytically.


title:
Functional renormalization group study of the pairing symmetry and
  pairing mechanism in iron-selenide superconductors

abstract:
  In iron selenide superconductors only electron-like Fermi pockets survive,
challenging the $S^{\pm}$ pairing based on the quasi-nesting between the
electron and hole Fermi pockets (as in iron arsenides). By functional
renormalization group study we show that an in-phase $S$-wave pairing on the
electron pockets ($S^{++}_{ee}$) is realized. The pairing mechanism involves
two competing driving forces: The strong C-type spin fluctuations cause
attractive pair scattering between and within electron pockets via Cooperon
excitations on the virtual hole pockets, while the G-type spin fluctuations
cause repulsive pair scattering. The latter effect is however weakened by the
hybridization splitting of the electron pockets. The resulting
$S^{++}_{ee}$-wave pairing symmetry is consistent with experiments. We further
propose that the quasiparticle interference pattern in scanning tunneling
microscopy and the Andreev reflection in out-of-plane contact tunneling are
efficient probes of in-phase versus anti-phase $S$-wave pairing on the electron
pockets.


title:
Fluorination Effects on the Structural Stability and Electronic
  Properties of sp3 Type Silicon Nanotubes

abstract:
  A density functional theory study of the structural and electronic properties
and relative stability of fluorinated sp3 silicon nanotubes and their
corresponding silicon nanowires built along various crystallographic
orientations is presented. The structural stability is found to increase
linearly with the fluorine surface coverage and for coverages exceeding 25% the
tubular structures are predicted to be more stable than their wire-like
counterparts. The bandgaps of the fully fluorinated systems are lower than
those of their fully hydrogenated counterparts by up to 0.79 eV for systems
having a relatively low silicon molar fraction. As the silicon molar fraction
increases these differences appear to reduce. For mixed fluorination and
hydrogenation surface decoration schemes the bandgaps usually lie between the
values of the fully hydrogenated and fully fluorinated systems. Furthermore,
the bandgap values of the silicon nanotubes are found to be more sensitive to
the fluorine surface coverage than those of the silicon nanowires. These
results indicate that surface functionalization may be used to control the
stability of narrow quasi-one-dimensional silicon nanostructures and opens the
way towards chemical tailoring of their electronic properties.


title:
Novel Topological Phases and Self-Correcting Memories in Interacting
  Anyon Systems

abstract:
  Recent studies have shown that topological models with interacting anyonic
quasiparticles can be used as self-correcting quantum memories. Here we study
the behaviour of these models at thermal equilibrium. It is found that the
interactions allow topological order to exist at finite temperature, not only
in an extension of the ground state phase but also in a novel form of
topologically ordered phase. Both phases are found to support self-correction
in all models considered, and the transition between them corresponds to a
change in the scaling of memory lifetime with system size.


title: Cover Tree Bayesian Reinforcement Learning

abstract:
  This paper proposes an online tree-based Bayesian approach for reinforcement
learning. For inference, we employ a generalised context tree model. This
defines a distribution on multivariate Gaussian piecewise-linear models, which
can be updated in closed form. The tree structure itself is constructed using
the cover tree method, which remains efficient in high dimensional spaces. We
combine the model with Thompson sampling and approximate dynamic programming to
obtain effective exploration policies in unknown environments. The flexibility
and computational simplicity of the model render it suitable for many
reinforcement learning problems in continuous state spaces. We demonstrate this
in an experimental comparison with least squares policy iteration.


title:
A long-term X-ray monitoring of the ultraluminous X-ray source NGC 5408
  X-1 with Swift reveals the presence of dips but no orbital period

abstract:
  NGC 5408 X-1 is a well-studied ultraluminous X-ray source (ULX) that has been
seen to emit in X-rays persistently above the Eddington limit of a stellar-mass
black hole for years. In this paper we report on the most extensive X-ray
monitoring of a ULX, using more than four years of observations from the Swift
satellite. We find that the 115 day periodicity reported by Strohmayer (2009)
disappeared after only a few cycles, confirming the suspicion of Foster et al.
(2010) that the periodicity is most likely super-orbital and not the orbital
period of the system. We also report on a clear dipping behaviour of the source
that may be related to a (super)-orbital phenomenon. All these features are
reminiscent of Galactic X-ray binaries and strengthen their link with ULXs.
Deeper observations of a dip could help resolve the ambiguity about the
interpretation of the spectral components of ULXs.


title: Nonadiabatic Van der Pol oscillations in molecular transport

abstract:
  The force exerted by the electrons on the nuclei of a current-carrying
molecular junction can be manipulated to engineer nanoscale mechanical systems.
In the adiabatic regime a peculiarity of these forces is negative friction,
responsible for Van der Pol oscillations of the nuclear coordinates. In this
work we study the robustness of the Van der Pol oscillations against
high-frequency bias and gate voltage. For this purpose we go beyond the
adiabatic approximation and perform full Ehrenfest dynamics simulations. The
numerical scheme implements a mixed quantum-classical algorithm for open
systems and is capable to deal with arbitrary time-dependent driving fields. We
find that the Van der Pol oscillations are extremely stable. The nonadiabatic
electron dynamics distorts the trajectory in the momentum-coordinate phase
space but preserves the limit cycles in an average sense. We further show that
high-frequency fields change both the oscillation amplitudes and the average
nuclear positions. By switching the fields off at different times one obtains
cycles of different amplitudes which attain the limit cycle only after
considerably long times.


title: Supergauge theories in aether superspace

abstract:
  Within the superfield method we extend the formulation of the
Lorentz-breaking aether superspace for supergauge theories, both in three- and
in four-dimensional cases.


title:
Existence, uniqueness and analyticity of space-periodic solutions to the
  regularised long-wave equation

abstract:
  We consider space-periodic evolutionary and travelling-wave solutions to the
regularised long-wave equation (RLWE) with damping and forcing. We establish
existence, uniqueness and smoothness of the evolutionary solutions for smooth
initial conditions, and global in time spatial analyticity of such solutions
for analytical initial conditions. The width of the analyticity strip decays at
most polynomially. We prove existence of travelling-wave solutions and
uniqueness of travelling waves of a sufficiently small norm. The importance of
damping is demonstrated by showing that the problem of finding travelling-wave
solutions to the undamped RLWE is not well-posed. Finally, we demonstrate the
asymptotic convergence of the power series expansion of travelling waves for a
weak forcing.


title: Evidence for effective mass reduction in GaAs/AlGaAs quantum wells

abstract:
  We have performed microwave photoresistance measurements in high mobility
GaAs/AlGaAs quantum wells and investigated the value of the effective mass.
Surprisingly, the effective mass, obtained from the period of microwave-induced
resistance oscillations, is found to be about 12% lower than the band mass in
GaAs, $\mb$. This finding provides strong evidence for electron-electron
interactions which can be probed by microwave photoresistance in very high
Landau levels. In contrast, the measured magnetoplasmon dispersion revealed an
effective mass which is close to $\mb$, in accord with previous studies.


title: Dimension of Alexandrov Topologies

abstract:
  We prove that the Krull dimension of an Alexandrov space of finite height can
be characterised with the specialisation preorder of its associated
$T_0$-space.