title: Model-independent no-arbitrage conditions on American put options

abstract:
  We consider the pricing of American put options in a model-independent
setting: that is, we do not assume that asset prices behave according to a
given model, but aim to draw conclusions that hold in any model. We incorporate
market information by supposing that the prices of European options are known.
  In this setting, we are able to provide conditions on the American Put prices
which are necessary for the absence of arbitrage. Moreover, if we further
assume that there are finitely many European and American options traded, then
we are able to show that these conditions are also sufficient. To show
sufficiency, we construct a model under which both American and European
options are correctly priced at all strikes simultaneously. In particular, we
need to carefully consider the optimal stopping strategy in the construction of
our process.


title: Broadword Implementation of Parenthesis Queries

abstract:
  We continue the line of research started in "Broadword Implementation of
Rank/Select Queries" proposing broadword (a.k.a. SWAR, "SIMD Within A
Register") algorithms for finding matching closed parentheses and the k-th far
closed parenthesis. Our algorithms work in time O(log w) on a word of w bits,
and contain no branch and no test instruction. On 64-bit (and wider)
architectures, these algorithms make it possible to avoid costly tabulations,
while providing a very significant speedup with respect to for-loop
implementations.


title: Drift Laws for Spiral Waves on Curved Anisotropic Surfaces

abstract:
  Rotating spiral waves organize spatial patterns in chemical, physical and
biological excitable systems. Factors affecting their dynamics such as
spatiotemporal drift are of great interest for par- ticular applications. Here,
we propose a quantitative description for spiral wave dynamics on curved
surfaces which shows that for a wide class of systems, including the BZ
reaction and anisotropic cardiac tissue, the Ricci curvature scalar of the
surface is the main determinant of spiral wave drift. The theory provides
explicit equations for spiral wave drift direction, drift velocity and the
period of rotation. Depending on the parameters, the drift can be directed to
the regions of either maximal or minimal Ricci scalar curvature, which was
verified by direct numerical simulations.


title: Requirements Issues in SoC and SoS

abstract:
  This position paper outlines some of the existing issues and challenges
concerned with the complexity of the requirements for service-oriented
computing and systems-of-systems applications.


title: A new approach to modifying theories of gravity

abstract:
  We propose a new point of view for interpreting Newton's and Einstein's
theories of gravity. By taking inspiration from Continuum Mechanics and its
treatment of anisotropies, we formulate new gravitational actions for modified
theories of gravity. These models are simple and natural generalisations with
many interesting properties. Above all, their precise form can, in principle,
be determined experimentally.


title: Two-field inflation with non-minimal coupling

abstract:
  Motivated by the recent `Higgs-inflation' scenario based on a single inflaton
field, we consider more generic two-field inflation with non-minimal coupling
term. The generic analytic expressions are derived for cosmological observables
with the product-separable as well as additive-separable potentials when the
non-minimal coupling term is dominated by one of the two fields. A hybrid model
of the inflaton potential $V=\mu^2 \phi^2 \left[1+\cos(\chi/\sigma)\right]$
with a non-minimal coupling $K=\alpha \phi$, which guarantees the flatness, is
closely examined as a concrete example. Compared to the minimal model with
$K=0$, the non-minimal model is shown to provide better fit to the recent
cosmological observation by WMAP9 and Planck2013 with the relatively lower
field values during the inflationary epoch. Most interestingly, a small value
of tensor-to-scalar ratio requires a large non-minimal coupling in our
scenario. The model produces non-observably small non-Gaussianity in most of
parameter space while a large non-Gaussianity($\sim {\mathcal O}(10)$) is
obtainable only when the inflation takes place in a limited field space along
the top of the potential.


title:
Kolmogorov complexity spectrum for use in analysis of UV-B radiation
  time series

abstract:
  We have used the Kolmogorov complexity and sample entropy measures to
estimate the complexity of the UV-B radiation time series in the Vojvodina
region (Serbia) for the period 1990-2007. We defined the Kolmogorov complexity
spectrum and have introduced the Kolmogorov complexity spectrum highest value
(KLM). We have established the UV-B radiation time series on the basis of their
daily sum (dose) for seven representative places in this region using (i)
measured data, (ii) data calculated via a derived empirical formula and (iii)
data obtained by a parametric UV radiation model. We have calculated the
Kolmogorov complexity (KL) based on the Lempel-Ziv Algorithm (LZA), KLM and
Sample Entropy (SE) values for each time series. We have divided the period
1990-2007 into two sub-intervals: (a) 1990-1998 and (b)1999-2007 and calculated
the KL, KLM and SE values for the various time series in these sub-intervals.
It is found that during the period 1999-2007, there is a decrease in the KL,
KLM and SE, comparing to the period 1990-1998. This complexity loss may be
attributed to (i) the increased human intervention in the post civil war period
causing increase of the air pollution and (ii) the increased cloudiness due to
climate changes.


title: Killing Vector Fields and Superharmonic Field Theories

abstract:
  The harmonic action functional allows a natural generalisation to
semi-Riemannian supergeometry, referred to as superharmonic action, which
resembles the supersymmetric sigma models studied in high energy physics. We
show that Killing vector fields are infinitesimal supersymmetries of the
superharmonic action and prove three different Noether theorems in this
context. En passant, we provide a homogeneous treatment of five
characterisations of Killing vector fields on semi-Riemannian supermanifolds,
thus filling a gap in the literature.


title: Modelling major failures in power grids in the whole range

abstract:
  Empirical research with electricity transmission networks reliability data
shows that the size of major failures - in terms of energy not supplied (ENS),
total loss of power (TLP) or restoration time (RT) - appear to follow a power
law behaviour in the upper tail of the distribution. However, this pattern -
also known as Pareto distribution - is not valid in the whole range of those
major events. We aimed to find a probability distribution that we could use to
model them, and hypothesized that there is a two-parameter model that fits the
pattern of those data well in the entire domain. We considered the major
failures produced between 2002 and 2009 in the European power grid; analyzed
those reliability indicators: ENS, TLP and RT; fitted six alternative models:
Pareto II, Fisk, Lognormal, Pareto, Weibull and Gamma distributions, to the
data by maximum likelihood; compared these models by the Bayesian information
criterion; tested the goodness-of-fit of those models by a Kolmogorov-Smirnov
test method based on bootstrap resampling; and validated them graphically by
rank-size plots. We found that Pareto II distribution is, in the case of ENS
and TLP, an adequate model to describe major events reliability data of power
grids in the whole range, and in the case of RT, is the best choice of the six
alternative models analyzed.


title:
A covering probability amplitude formalism for classical and quantum
  mechanics, and possible new modes of non-classical behaviour

abstract:
  A generalized dynamics is postulated in a product space ${\cal R}^{3}\times
{\cal S}^{1}$ with ${\cal R}^3$ representing the configuration space of a one
particle system to which is attached the U(1) fibre bundle represented by the
manifold ${\cal S}^{1}$. The manifold ${\cal S}^{1}$ is chosen to correspond to
the action phase, with the action being the principal function corresponding to
the associated classical dynamical system. A Hilbert space representation of
the flow equation representing the dynamics in the above product space is then
obtained, which is found to yield a probability amplitude formalism in terms of
a generalized set of equations of the Schr\"odinger form which constitutes a
covering formalism for both quantum and classical mechanics. Being labelled by
an integral index $n$, the equation corresponding to $n=1$ is identified with
the Schr\"odinger equation, while equations corresponding to $n\rightarrow
large$ yield the classical dynamics through the WKB limit. Equations with lower
indices n=2,3,4,... predict the existence of new modes of non-classical
behaviour, the observational implications of which are discussed. Some
preliminary experimental results are presented which point to the existence of
these modes of non-classical behaviour.


title: The investigations of anisotropy in orientations of galaxies

abstract:
  In 1994 Parnovsky, Karachentsev and Karachentseva suggested a modified method
for investigation of the orientations of galaxies. Using this method they
analyzed galaxies from the UGC and ESO catalogues, as well as from their's own
catalogue inclusive of flat, edge-on galaxies. They found statistically
significant anisotropy in the galaxies orientations'. In 1995 Flin suggested
that this anisotropy has to be specific to LOcal Supercluster (LSC) In the
present paper, using the method proposed by Parnovsky, Karachentsev and
Karachentseva in 1994, we analyzed orientation of galaxies in the sample of
galaxies belonging to LSC founding only a weak anisotropy. The relation of this
method to Hawley and Peebles (1975) method of the investigation of the
orientation of galaxies was discussed as well.


title: Statistical properties of twin kHz QPO in neutron star LMXBs

abstract:
  We collect the data of twin kilohertz quasi-periodic oscillations (kHz QPOs)
published before 2012 from 26 neutron star (NS) low-mass X-ray binary (LMXB)
sources, then we analyze the centroid frequency (\nu) distribution of twin kHz
QPOs (lower frequency \nu_1 and upper frequency \nu_2) both for Atoll and Z
sources. For the data without shift-and-add, we find that Atoll and Z sources
show the different distributions of \nu_1, \nu_2 and \nu_2/\nu_1, but the same
distribution of \Delta\nu (difference of twin kHz QPOs), which indicates that
twin kHz QPOs may share the common properties of LXMBs and have the same
physical origins. The distribution of \Delta\nu is quite different from
constant value, so is \nu_2/\nu_1 from constant ratio. The weighted mean values
and maxima of \nu_1 and \nu_2 in Atoll sources are slightly higher than those
in Z sources. We also find that shift-and-add technique can reconstruct the
distribution of \nu_1 and \Delta\nu. The K-S test results of \nu_1 and
\Delta\nu between Atoll and Z sources from data with shift-and-add are quite
different from those without it, and we think that this may be caused by the
selection biases of the sample. We also study the properties of the quality
factor (Q) and the root-mean-squared (rms) amplitude of 4U 0614+09 with the
data from the two observational methods, but the errors are too big to make a
robust conclusion. The NS spin frequency (\nu_s) distribution of 28 NS-LMXBs
show a bigger mean value (about 408Hz) than that (about 281 Hz) of the radio
binary millisecond pulsars (MSPs), which may be due to the lack of the spin
detections from Z sources (systematically lower than 281 Hz). Furthermore, on
the relations between the kHz QPOs and NS spin frequency \nu_s, we find the
approximate correlations of the mean values of \Delta\nu with NS spin and its
half, respectively.


title: Higgs decay to goldstini and its observability at the LHC

abstract:
  If supersymmetry is broken independently in multiple sectors with different
scales, a number of goldstinos will be generated. One linear combination of
these goldstinos is massless and eaten by the gravitino, while the orthogonal
combinations acquire a tree level mass and become the physical states named
goldstini (G'). Compared to the gravitino, such goldstini could couple more
strongly to the visible fields and lead to some exotic phenomenology. In this
note we first check the goldstini couplings in some GMSB models and find that
the goldstini-photon-neutralino interaction may be very small while the
goldstini-Z-neutralino and goldstini-Higgs-neutralino interactions may be
sizable. This can induce a new decay mode for the Higgs boson: h-> G'+\chi ->
Z+2G'. Then in an effective model with conservative fixed parameters we study
the observability of this decay channel at the LHC and find that it is not
accessible at the finished 8 TeV run (25 /fb) or 14 TeV run with 100 /fb, but
might be observed at the high luminosity LHC (14 TeV, 1000-3000 /fb) if the
systematics of the backgrounds can be well understood.


title: On the $q$-Laplace transform in the non-extensive statistical physics

abstract:
  In this paper, q-Laplace transforms related to the non-extensive
thermodynamics are investigated by using the algebraic operation of the
non-extensive calculus. The deformed simple harmonic problem is discussed by
using the q-Laplace transform.


title: Quantum Gravity: the view from particle physics

abstract:
  This lecture reviews aspects of and prospects for progress towards a theory
of quantum gravity from a particle physics perspective, also paying attention
to recent findings of the LHC experiments at CERN.


title:
Relative Generalized Rank Weight of Linear Codes and Its Applications to
  Network Coding

abstract:
  By extending the notion of minimum rank distance, this paper introduces two
new relative code parameters of a linear code C_1 of length n over a field
extension and its subcode C_2. One is called the relative
dimension/intersection profile (RDIP), and the other is called the relative
generalized rank weight (RGRW). We clarify their basic properties and the
relation between the RGRW and the minimum rank distance. As applications of the
RDIP and the RGRW, the security performance and the error correction capability
of secure network coding, guaranteed independently of the underlying network
code, are analyzed and clarified. We propose a construction of secure network
coding scheme, and analyze its security performance and error correction
capability as an example of applications of the RDIP and the RGRW. Silva and
Kschischang showed the existence of a secure network coding in which no part of
the secret message is revealed to the adversary even if any dim C_1-1 links are
wiretapped, which is guaranteed over any underlying network code. However, the
explicit construction of such a scheme remained an open problem. Our new
construction is just one instance of secure network coding that solves this
open problem.


title:
An Asymptotically Stable Continuous Robust Controller for a Class of
  Uncertain MIMO Nonlinear Systems

abstract:
  In this work, we propose the design and analysis of a novel continuous robust
controller for a class of multi--input multi--output (MIMO) nonlinear uncertain
systems. The systems under consideration contains unstructured uncertainties in
their drift and input matrices. The proposed controller compensates the overall
system uncertainties and achieves asymptotic tracking where only the sign of
the leading minors of the input gain matrix is assumed to be known. A Lyapunov
based argument backed up with an integral inequality is applied to prove
stability of the proposed controller and asymptotic convergence of the error
signals. Simulation results are presented in order to illustrate the viability
of the proposed method.


title:
Automated Quantitative Description of Spiral Galaxy Arm-Segment
  Structure

abstract:
  We describe a system for the automatic quantification of structure in spiral
galaxies. This enables translation of sky survey images into data needed to
help address fundamental astrophysical questions such as the origin of spiral
structure---a phenomenon that has eluded theoretical description despite 150
years of study (Sellwood 2010). The difficulty of automated measurement is
underscored by the fact that, to date, only manual efforts (such as the citizen
science project Galaxy Zoo) have been able to extract information about large
samples of spiral galaxies. An automated approach will be needed to eliminate
measurement subjectivity and handle the otherwise-overwhelming image quantities
(up to billions of images) from near-future surveys. Our approach automatically
describes spiral galaxy structure as a set of arcs, precisely describing spiral
arm segment arrangement while retaining the flexibility needed to accommodate
the observed wide variety of spiral galaxy structure. The largest existing
quantitative measurements were manually-guided and encompassed fewer than 100
galaxies, while we have already applied our method to more than 29,000
galaxies. Our output matches previous information, both quantitatively over
small existing samples, and qualitatively against human classifications from
Galaxy Zoo.


title: On the variety of strict pseudosemilattices

abstract:
  A new model, in terms of finite bipartite graphs, of the free
pseudosemilattice is presented. This will then be used to obtain several
results about the variety SPS of all strict pseudosemilattices: (i) an identity
basis for SPS is found, (ii) SPS is shown to be inherently non-finitely based,
(iii) SPS is shown to have no irredundant identity basis, and (iv) SPS is shown
to have no covers and to be meet-prime in the lattice of all varieties of
pseudosemilattices. Some applications to e-varieties of locally inverse
semigroups are also derived.


title:
Uniqueness of equivariant compactifications of C^n by a Fano manifold of
  Picard number 1

abstract:
  Let X be an $n$-dimensional Fano manifold of Picard number 1. We study how
many different ways X can compactify the complex vector group C^n
equivariantly. Hassett and Tschinkel showed that when X = P^n with n \geq 2,
there are many distinct ways that X can be realized as equivariant
compactifications of C^n. Our result says that projective space is an
exception: among Fano manifolds of Picard number 1 with smooth VMRT, projective
space is the only one compactifying C^n equivariantly in more than one ways.
This answers questions raised by Hassett-Tschinkel and Arzhantsev-Sharoyko.


title: Inhomogeneous High-order Harmonic Generation in Krypton Clusters

abstract:
  High order harmonic generation from clusters is a controversial topic:
conflicting theories exist, with different explanations for similar
experimental observations. From an experimental point of view, separating the
contributions from monomers and clusters is challenging. By performing a
spectrally and spatially resolved study in a controlled mixture of clusters and
monomers, we are able to isolate a region of the spectrum where the emission
purely originates from clusters. Surpringly, the emission from clusters is
depolarized, which is the signature of statistical inhomogeneous emission from
a low-density source. The harmonic response to laser ellipticity shows that
this generation is produced by a new recollisional mechanism, which opens the
way to future theoretical studies.


title:
Multi-class Generalized Binary Search for Active Inverse Reinforcement
  Learning

abstract:
  This paper addresses the problem of learning a task from demonstration. We
adopt the framework of inverse reinforcement learning, where tasks are
represented in the form of a reward function. Our contribution is a novel
active learning algorithm that enables the learning agent to query the expert
for more informative demonstrations, thus leading to more sample-efficient
learning. For this novel algorithm (Generalized Binary Search for Inverse
Reinforcement Learning, or GBS-IRL), we provide a theoretical bound on sample
complexity and illustrate its applicability on several different tasks. To our
knowledge, GBS-IRL is the first active IRL algorithm with provable sample
complexity bounds. We also discuss our method in light of other existing
methods in the literature and its general applicability in multi-class
classification problems. Finally, motivated by recent work on learning from
demonstration in robots, we also discuss how different forms of human feedback
can be integrated in a transparent manner in our learning framework.


title: Asymptotic Freeness of Jucys-Murphy element and a certain projection

abstract:
  We explain the appearance of the free compression of a transition measure in
the problem of the restriction of the representation of the symmetric group to
a subgroup by showing the responsible free projection.


title:
Structural, electronic and optical characterization of bulk platinum
  nitrides: a first-principles study

abstract:
  We present a detailed quantum mechanical non empirical DFT investigation of
the energy-optimized geometries, phase stabilities and electronic properties of
bulk Pt3N, PtN and PtN2 in a set of twenty different crystal structures.
Structural preferences for these three stoichiometries were analyzed and
equilibrium structural parameters were determined. We carefully investigated
the band-structure and density of states of the relatively most stable phases.
Further, GW_0 calculations within the random-phase approximation (RPA) to the
dielectric tensor were carried out to derive their frequency-dependent optical
constants of the most likely candidates for the true crystal structure.
Obtained results were comprehensively compared to previous calculations and to
experimental data.


title: ChESS - Quick and Robust Detection of Chess-board Features

abstract:
  Localization of chess-board vertices is a common task in computer vision,
underpinning many applications, but relatively little work focusses on
designing a specific feature detector that is fast, accurate and robust. In
this paper the `Chess-board Extraction by Subtraction and Summation' (ChESS)
feature detector, designed to exclusively respond to chess-board vertices, is
presented. The method proposed is robust against noise, poor lighting and poor
contrast, requires no prior knowledge of the extent of the chess-board pattern,
is computationally very efficient, and provides a strength measure of detected
features. Such a detector has significant application both in the key field of
camera calibration, as well as in Structured Light 3D reconstruction. Evidence
is presented showing its robustness, accuracy, and efficiency in comparison to
other commonly used detectors both under simulation and in experimental 3D
reconstruction of flat plate and cylindrical objects


title: Complexity $L^0$-penalized M-Estimation: Consistency in More Dimensions

abstract:
  We study the asymptotics in $L^2$ for complexity penalized least squares
regression for the discrete approximation of finite-dimensional signals on
continuous domains - e.g. images - by piecewise smooth functions.
  We introduce a fairly general setting which comprises most of the presently
popular partitions of signal- or image- domains like interval-, wedgelet- or
related partitions, as well as Delaunay triangulations. Then we prove
consistency and derive convergence rates. Finally, we illustrate by way of
relevant examples that the abstract results are useful for many applications.


title: Yet More Smooth Mapping Spaces and Their Smoothly Local Properties

abstract:
  Motivated by the definition of the smooth manifold structure on a suitable
mapping space, we consider the general problem of how to transfer local
properties from a smooth space to an associated mapping space. This leads to
the notion of smoothly local properties.
  In realising the definition of a local property at a particular point it may
be that there are choices that need to be made. To say that the local property
is smoothly local is to say that those choices can be made smoothly dependent
on the point. In particular, that a manifold has charts is a local property. A
local addition is the structure needed to say that there is a way to choose a
chart about each point so that it varies smoothly with that point.
  To be able to extend these ideas beyond that of the local additivity of
manifolds we work in a category of generalised smooth spaces. We are thus are
able to consider more general mapping spaces than just those arising from the
maps from one smooth manifold to another and thus able to generalise the
standard result on when this space of maps is again a smooth manifold.
  As applications of this generalisation we show that the mapping spaces
involving the various figure 8s from String Topology are manifolds, and that
they embed as submanifolds with tubular neighbourhoods in the corresponding
loop spaces. We also show that applying the mapping space functor to a regular
map of manifolds produces a regular map on the mapping spaces.


title: On the Dynamics of Large Particle Systems in the Mean Field Limit

abstract:
  This course explains how the usual mean field evolution partial differential
equations (PDEs) in Statistical Physics - such as the Vlasov-Poisson system,
the vorticity formulation of the two-dimensional Euler equation for
incompressible fluids, or the time-dependent Hartree equation in quantum
mechanics - can be rigorously derived from first principles, i.e. from the
fundamental microscopic equations that govern the evolution of large,
interacting particle systems. The emphasis is put on the mathematical methods
used in these derivations, such as Dobrushin's stability estimate in the
Monge-Kantorovich distance for the empirical measures built on the solution of
the N-particle motion equations in classical mechanics, or the theory of BBGKY
hierarchies in the case of classical as well as quantum problems. We explain in
detail how these different approaches are related; in particular we insist on
the notion of chaotic sequences and on the propagation of chaos in the BBGKY
hierarchy as the number of particles tends to infinity.


title: The asymptotic safety scenario and scalar field inflation

abstract:
  We study quantum gravity corrections to early universe cosmology as resulting
within the asymptotic safety scenario. We analyse if it is possible to obtain
accelerated expansion in the regime of the renormalisation group fixed point in
a theory with Einstein-Hilbert gravity and a scalar field. We show how this
phase impacts cosmological perturbations observed in the cosmic microwave
background.


title: Duality-invariant bimetric formulation of linearized gravity

abstract:
  A formulation of linearized gravity which is manifestly invariant under
electric-magnetic duality rotations in the internal space of the metric and its
dual, and which contains both metrics as basic variables (rather than the
corresponding prepotentials), is derived. In this bimetric formulation, the
variables have a more immediate geometrical significance, but the action is
non-local in space, contrary to what occurs in the prepotential formulation.
More specifically, one finds that: (i) the kinetic term is non-local in space
(but local in time); (ii) the Hamiltonian is local in space and in time; (iii)
the variables are subject to two Hamiltonian constraints, one for each metric.


title: Suitability of Capital Allocations for Performance Measurement

abstract:
  Capital allocation principles are used in various contexts in which a risk
capital or a cost of an aggregate position has to be allocated among its
constituent parts. We study capital allocation principles in a performance
measurement framework. We introduce the notation of suitability of allocations
for performance measurement and show under different assumptions on the
involved reward and risk measures that there exist suitable allocation methods.
The existence of certain suitable allocation principles generally is given
under rather strict assumptions on the underlying risk measure. Therefore we
show, with a reformulated definition of suitability and in a slightly modified
setting, that there is a known suitable allocation principle that does not
require any properties of the underlying risk measure. Additionally we extend a
previous characterization result from the literature from a mean-risk to a
reward-risk setting. Formulations of this theory are also possible in a game
theoretic setting.


title:
Particle-Antiparticle Mixing, CP Violation and Rare K and B Decays in a
  Minimal Theory of Fermion Masses

abstract:
  We present a detailed study of Delta F=2 observables and of rare K^+(K_L) and
B_{s,d} meson decays in a "Minimal Theory of Fermion Masses" (MTFM). In this
theory Yukawa couplings are generated through the mixing with heavy vectorlike
(VF) fermions. This implies corrections to the SM quark couplings to W, Z and
Higgs so that FCNC processes receive contributions from tree level Z and Higgs
exchanges and W bosons couple to right-handed quarks. In a particular version
of this model in which the Yukawa matrix lambda^D in the heavy down fermion
sector is unitary, lambda^U =1 and M = M_{VF} is fixed, only three real and
positive definite parameters describe New Physics (NP) contributions to all
Delta F=2 and Delta F=1 observables in K and B_{s,d} systems once the known
quark masses and the CKM matrix are correctly reproduced. For M>1 TeV NP
contributions to B_{s,d}^0- bar{B}_{s,d}^0 mixings are found to be very small.
While in principle NP contributions to epsilon_K and Delta F=1 processes could
be large, the correlation between epsilon_K and K_L->mu^+ mu^- eliminates
basically NP contributions to epsilon_K and right-handed current contributions
to Delta F=1 FCNC observables. We find CMFV structure in B_{s,d} decays with
BR(B_{s,d}->mu^+ mu^-) uniquely enhanced for M=3 TeV by at least 35% and almost
up to a factor of two over their SM values. Also BR(K^+->pi^+ bar{nu} nu) and
BR(K_L->pi^0 bar{nu} nu)$ are uniquely enhanced by similar amount but the
correlation between them differs from the CMFV one. We emphasize various
correlations between K and B_{s,d} decays that could test this scenario. The
model favours gamma=68{\deg}, |V_{ub}|=0.0037, S_{psi K_S}=0.72, S_{psi
phi}=0.04 and 4.2*10^-9<BR(B_s->mu^+ mu^-)<5.0*10^-9 for M=3-4 TeV.


title:
Transit Timing Observations from Kepler. VIII Catalog of Transit Timing
  Measurements of the First Twelve Quarters

abstract:
  Following Ford et al. (2011, 2012) and Steffen et al. (2012) we derived the
transit timing of 1960 Kepler KOIs using the pre-search data conditioning (PDC)
light curves of the first twelve quarters of the Kepler data. For 721 KOIs with
large enough SNRs, we obtained also the duration and depth of each transit. The
results are presented as a catalog for the community to use. We derived a few
statistics of our results that could be used to indicate significant
variations. Including systems found by previous works, we have found 130 KOIs
that showed highly significant TTVs, and 13 that had short-period TTV
modulations with small amplitudes. We consider two effects that could cause
apparent periodic TTV - the finite sampling of the observations and the
interference with the stellar activity, stellar spots in particular. We briefly
discuss some statistical aspects of our detected TTVs. We show that the TTV
period is correlated with the orbital period of the planet and with the TTV
amplitude.


title: The Power of Priority Channel Systems

abstract:
  We introduce Priority Channel Systems, a new class of channel systems where
messages carry a numeric priority and where higher-priority messages can
supersede lower-priority messages preceding them in the fifo communication
buffers. The decidability of safety and inevitability properties is shown via
the introduction of a priority embedding, a well-quasi-ordering that has not
previously been used in well-structured systems. We then show how Priority
Channel Systems can compute Fast-Growing functions and prove that the
aforementioned verification problems are
$\mathbf{F}_{\varepsilon_{0}}$-complete.


title: Effects of Twisted Noncommutativity in Multi-particle Hamiltonians

abstract:
  The noncommutativity induced by a Drinfel'd twist produces Bopp-shift like
transformations for deformed operators. In a single-particle setting the
Drinfel'd twist allows to recover the noncommutativity obtained from various
methods which are not based on Hopf algebras. In multi-particle sector, on the
other hand, the Drinfel'd twist implies novel features. In conventional
approaches to noncommutativity, deformed primitive operators are postulated to
act additively. A Drinfel'd twist implies non-additive effects which are
controlled by the coproduct. We illustrate these features for a class of
(abelian twist-deformed) 2D Hamiltonians. Suitable choices of the parameters
lead to the Hamiltonian of the noncommutative Quantum Hall Effect, the harmonic
oscillator, the quantization of the configuration space. The non-additive
effects in the multi-particle sector, leading to results departing from the
existing literature, are pointed out.


title: In vivo facilitated diffusion model

abstract:
  Under dilute in vitro conditions transcription factors rapidly locate their
target sequence on DNA by using the facilitated diffusion mechanism. However,
whether this strategy of alternating between three-dimensional bulk diffusion
and one-dimensional sliding along the DNA contour is still beneficial in the
crowded interior of cells is highly disputed. Here we use a simple model for
the bacterial genome inside the cell and present a semi-analytical model for
the in vivo target search of transcription factors within the facilitated
diffusion framework. Without having to resort to extensive simulations we
determine the mean search time of a lac repressor in a living E. coli cell by
including parameters deduced from experimental measurements. The results agree
very well with experimental findings, and thus the facilitated diffusion
picture emerges as a quantitative approach to gene regulation in living
bacteria cells. Furthermore we see that the search time is not very sensitive
to the parameters characterizing the DNA configuration and that the cell seems
to operate very close to optimal conditions for target localization. Local
searches as implied by the colocalization mechanism are only found to mildly
accelerate the mean search time within our model.


title:
Unpolarized, incoherent repumping light for prevention of dark states in
  a trapped and laser-cooled single ion

abstract:
  Many ion species commonly used for laser-cooled ion trapping studies have a
low-lying metastable 2D3/2 state that can become populated due to spontaneous
emission from the 2P1/2 excited state. This requires a repumper laser to
maintain the ion in the Doppler cooling cycle. Typically the 2D3/2 state, or
some of its hyperfine components if the ion has nuclear spin, has a higher
multiplicity than the upper state of the repumping transition. This can lead to
dark states, which have to be destabilized by an external magnetic field or by
modulating the polarization of the repumper laser. We propose using
unpolarized, incoherent amplified spontaneous emission (ASE) to drive the
repumping transition. An ASE source offers several advantages compared to a
laser. It prevents the buildup of dark states without external polarization
modulation even in zero magnetic field, it can drive multiple hyperfine
transitions simultaneously, and it requires no frequency stabilization. These
features make it very compact and robust, which is essential for the
development of practical, transportable optical ion clocks. We construct a
theoretical model for the ASE radiation, including the possibility of the
source being partially polarized. Using 88Sr+ as an example, the performance of
the ASE source compared to a single-mode laser is analyzed by numerically
solving the eight-level density matrix equations for the involved energy
levels. Finally a reduced three-level system is derived, yielding a simple
formula for the excited state population and scattering rate, which can be used
to optimize the experimental parameters. The required ASE power spectral
density can be obtained with current technology.


title: Cash Flow Entropy

abstract:
  In this paper we aim to find a measure for the diversity of cash flows
between agents in an economy. We argue that cash flows can be linked to
probabilities of finding a currency unit in a given cash flow. We then use the
information entropy as a natural measure of diversity. This leads to a
hirarchical inequality measure, which includes the well-known Theil index as a
special case, and a constraint on agent entropy differentials, i.e., the
difference between cash inflow and outflow entropies. The last result is
particularly intriguing as it formalises the fact that an economy must contain
both, cash flow aggregating and cash flow diversifying agents.


title: Special Functions in Minimal Representations

abstract:
  Minimal representations of a real reductive group G are the `smallest'
irreducible unitary representations of G. We discuss special functions that
arise in the analysis of L^2-model of minimal representations.


title:
Relativistic runaway electron breakdown and Terrestrial Gamma ray
  Flashes: GEANT4 simulation

abstract:
  Numerical simulation of a relativistic runaway electron breakdown in the
upper atmosphere is performed using GEANT4 simulation toolkit. General features
of a relativistic runaway electron avalanche are reconstructed and properties
of radiations accompanying breakdown are obtained. It is demonstrated
dependance of the high energy branch of photon spectra with respect to an
altitude and shown what at the reasonable parameters hard photons have spectral
index close to the observed value.


title:
Strong orthogonality between the M\"obius function, additive characters,
  and Fourier coefficients of cusp forms

abstract:
  Let $\nu_{f}(n)$ be the $n$-th nomalized Fourier coefficient of a
Hecke--Maass cusp form $f$ for ${\rm SL}(2,\Z)$ and let $\alpha$ be a real
number. We prove strong oscillations of the argument of $\nu_{f}(n)\mu (n) \exp
(2\pi i n \alpha)$ as $n$ takes consecutive integral values.


title: Shear-free perfect fluids with linear equation of state

abstract:
  We prove that shear-free perfect fluid solutions of Einstein's field
equations must be either expansion-free or non-rotating (as conjectured by
Treciokas and Ellis) for all linear equations of state $p = w \rho$ except for
six values of $w$.


title:
On the rest and flat limits of the scalar modes on the de Sitter
  spacetime

abstract:
  The scalar mode functions on the spatially flat FLRW chart of the de Sitter
spacetime are redefined in order to obtain a natural frequencies separation in
the special local charts where the momentum vanishes, called here (natural)
rest frames. This can be done since in such frames the mode functions are
eigenfunctions of the energy operator. Moreover, the most general criteria for
choosing the suitable phase factors of the mode functions able to
simultaneously determine the correct rest and flat limits are established.
These results are compared to the different original choices from the
literature.
  Pacs: 04.62.+v


title:
Statistical testing of shared genetic control for potentially related
  traits

abstract:
  Integration of data from genome-wide single nucleotide polymorphism (SNP)
association studies of different traits should allow researchers to disentangle
the genetics of potentially related traits within individually associated
regions. Formal statistical colocalisation testing of individual regions, which
requires selection of a set of SNPs summarizing the association in a region. We
show that the SNP selection method greatly affects type 1 error rates, with
published studies having used methods expected to result in substantially
inflated type 1 error rates. We show that either avoiding variable selection
and instead testing the most informative principal components or integrating
over variable selection using Bayesian model averaging can lead to correct
control of type 1 error rates. Application to data from Graves' disease and
Hashimoto's thyroiditis reveals a common genetic signature across seven regions
shared between the diseases, and indicates that in five of six regions
associated with Graves' disease and not Hashimoto's thyroiditis, this more
likely reflects genuine absence of association with the latter rather than lack
of power. Our examination, by simulation, of the performance of colocalisation
tests and associated software will foster more widespread adoption of formal
colocalisation testing. Given the increasing availability of large expression
and genetic association data sets from disease-relevant tissue and purified
cell populations, coupled with identification of regulatory sequences by
projects such as ENCODE, colocalisation analysis has the potential to reveal
both shared genetic signatures of related traits and causal disease genes and
tissues.


title: Models for Neutrino Masses and Mixings

abstract: We review recent developments towards models for neutrino masses and mixings.


title:
The reconstructed tree in the lineage-based model of protracted
  speciation

abstract:
  A popular line of research in evolutionary biology is the use of
time-calibrated phylogenies for the inference of diversification processes.
This requires computing the likelihood of a given ultrametric tree as the
reconstructed tree produced by a given model of diversification. Etienne &
Rosindell (2012) proposed a lineage-based model of diversification, called
protracted speciation, where species remain incipient during a random duration
before turning good species, and showed that this can explain the slowdown in
lineage accumulation observed in real phylogenies. However, they were unable to
provide a general likelihood formula. Here, we present a likelihood formula for
protracted speciation models, where rates at which species turn good or become
extinct can depend both on their age and on time. Our only restrictive
assumption is that speciation rate does not depend on species status.
  Our likelihood formula utilizes a new technique, based on the contour of the
phylogenetic tree and first developed in Lambert (2010). We consider the
reconstructed trees spanned by all extant species, by all good extant species,
or by all representative species, which are either good extant species or
incipient species representative of some good extinct species. Specifically, we
prove that each of these trees is a coalescent point process, that is, a
planar, ultrametric tree where the coalescence times between two consecutive
tips are independent, identically distributed random variables. We characterize
the common distribution of these coalescence times in some, biologically
meaningful, special cases for which the likelihood reduces to an elegant
analytical formula or becomes numerically tractable.


title:
Structural phase transition and band gap of uniaxially deformed (6,0)
  carbon nanotube

abstract:
  The atomic and band structures of the (6,0) zigzag carbon nanotube at its
axial elongation are calculated by semiempirical molecular orbital and by
tight-binding methods. The ground state of the nanotube is found to have a
Kekule structure with four types of bonds and difference between lengths of
long and short bonds of about 0.005 nm. The structural phase transition is
revealed at ~9% elongation, resulting in a quinoid structure with two types of
bonds. This structural phase transition is followed by the transition from a
narrow gap to moderate gap semiconductor. Validity of the semiempirical PM3
method is discussed.


title: White Paper on GEMS Study of Polarized X-rays from Neutron Stars

abstract:
  We examine the expected X-ray polarization properties of neutron-star X-ray
sources of various types, e.g., accretion and rotation powered pulsars,
magnetars, and low-mass X-ray binaries. We summarize the model calculations
leading to these expected properties. We describe how a comparison of these
with their observed properties, as inferred from GEMS data, will probe the
essential dynamical, electromagnetic, plasma, and emission processes in
neutron-star binaries, discriminate between models of these processes, and
constrain model parameters. An exciting goal is the first observational
demonstration in this context of the existence of vacuum resonance, a
fundamental quantum electrodynamical phenomenon first described in the 1930s.


title: Mutually Equidistant Spheres that Intersect

abstract:
  The setting for this brief paper is R^3. Distance between two spheres is
understood as distance delta between spherical centers. For instance, a
Reuleaux tetrahedron T is the intersection of four unit balls satisfying
delta=1 pairwise. Volume and surface area of T are already well-known; our
humble contribution is to calculate the mean width of T.


title:
Search for GeV-scale sterile neutrinos responsible for active neutrino
  oscillations and baryon asymmetry of the Universe

abstract:
  Standard model of particle physics fails to explain neutrino oscillations,
dark matter and baryon asymmetry of the Universe. All these problems can be
solved with three sterile neutrinos added to the model. Quite remarkably, if
sterile neutrino masses are well below the electroweak scale, this modification
--- Neutrino Minimal Standard Model (nuMSM) --- can be tested experimentally.
We discuss a new experiment on search for decays of GeV-scale sterile
neutrinos, which in the framework of the nuMSM are responsible for the
matter-antimatter asymmetry generation and for the active neutrino masses. If
lighter than 2 GeV, these particles can be produced in decays of charm mesons
generated by high energy protons in a target of a proton beam-dump experiment,
and subsequently decay into light SM particles. In order to fully explore this
sector of the nuMSM, the new experiment requires data obtained with at least
10^{20} incident protons on target (achievable at CERN SPS in the future), and
a big volume detector constructed from a large amount of identical single
modules, with a total sterile neutrino decay length of few kilometers. The
preliminary feasibility study for the proposed experiment shows that it has
sensitivity which may either lead to the discovery of new particles below the
Fermi scale --- right-handed partners of neutrinos --- or rule out see-saw
sterile neutrinos with masses below 2 GeV.


title:
Theoretical investigation of FeTe magnetic ordering under hydrostatic
  pressure

abstract:
  We investigate the pressure phase diagram of FeTe, predicting structural and
magnetic properties in the normal state at zero temperature within density
functional theory (DFT). We carefully examined several possible different
crystal structures over a pressure range up to $\approx 30 $ GPa: simple
tetragonal (PbO type), simple monoclinic, orthorhombic (MnP type), hexagonal
(NiAs and wurzite type) and cubic (CsCl and NaCl type). We predict pressure to
drive the system through different magnetic ordering (notably also some
ferromagnetic phases) eventually suppressing magnetism at around 17GPa. We
speculate the ferromagnetic order to be the reason for the absence of a
superconducting phase in FeTe at variance with the case of FeSe.


title: Shedding Light on Three-Body Recombination in an Ultracold Atomic Gas

abstract:
  Three-body recombination is a prime example of the fundamental interaction
between three particles. Due to the complexity of this process it has resisted
a comprehensive description. Experimental investigations have mainly focussed
on the observation of corresponding loss rates without revealing information on
the reaction products. Here, we provide the first general experimental study on
the population distribution of molecular quantum states after three-body
recombination in a non-resonant regime. We have developed a highly sensitive
detection scheme which combines photoionization of the molecules with
subsequent ion trapping. By analyzing the ionization spectrum, we identify the
population of energy levels with binding energies up to $h\times 750\:$GHz. We
find a broad population of electronic and nuclear spin states and determine a
range of populated vibrational and rotational states. The method presented here
can be expanded to provide a full survey of the products of the recombination
process. This may be pivotal in developing an in-depth model that can
qualitatively and quantitatively predict the reaction products of three-body
recombination.


title: Lagrangian Markovianized Field Approximation for turbulence

abstract:
  In a previous communication (W.J.T. Bos and J.-P. Bertoglio 2006, Phys.
Fluids, 18, 031706), a self-consistent Markovian triadic closure was presented.
The detailed derivation of this closure is given here, relating it to the
Direct Interaction Approximation and Quasi-Normal types of closure. The
time-scale needed to obtain a self-consistent closure for both the energy
spectrum and the scalar variance spectrum is determined by evaluating the
correlation between the velocity and an advected displacement vector-field. The
relation between this latter correlation and the velocity-scalar correlation is
stressed, suggesting a simplified model of the latter. The resulting closed
equations are numerically integrated and results for the energy spectrum,
scalar fluctuation spectrum and velocity-displacement correlation spectrum are
presented for low, unity and high values of the Schmidt number.


title: Bilinear pairings on elliptic curves

abstract:
  We give an elementary and self-contained introduction to pairings on elliptic
curves over finite fields. For the first time in the literature, the three
different definitions of the Weil pairing are stated correctly and proved to be
equivalent using Weil reciprocity. Pairings with shorter loops, such as the
ate, ate$_i$, R-ate and optimal pairings, together with their twisted variants,
are presented with proofs of their bilinearity and non-degeneracy. Finally, we
review different types of pairings in a cryptographic context. This article can
be seen as an update chapter to A. Enge, Elliptic Curves and Their Applications
to Cryptography - An Introduction, Kluwer Academic Publishers 1999.


title: Singular values of multiple eta-quotients for ramified primes

abstract:
  We determine the conditions under which singular values of multiple
$\eta$-quotients of square-free level, not necessarily prime to~6, yield class
invariants, that is, algebraic numbers in ring class fields of
imaginary-quadratic number fields. We show that the singular values lie in
subfields of the ring class fields of index $2^{k' - 1}$ when $k' \geq 2$
primes dividing the level are ramified in the imaginary-quadratic field, which
leads to faster computations of elliptic curves with prescribed complex
multiplication. The result is generalised to singular values of modular
functions on $X_0^+ (p)$ for $p$ prime and ramified.


title: On Gaussian Half-Duplex Relay Networks

abstract:
  This paper considers Gaussian relay networks where a source transmits a
message to a sink terminal with the help of one or more relay nodes. The relays
work in half-duplex mode, in the sense that they can not transmit and receive
at the same time. For the case of one relay, the generalized Degrees-of-Freedom
is characterized first and then it is shown that capacity can be achieved to
within a constant gap regardless of the actual value of the channel parameters.
Different achievable schemes are presented with either deterministic or random
switch for the relay node. It is shown that random switch in general achieves
higher rates than deterministic switch. For the case of K relays, it is shown
that the generalized Degrees-of-Freedom can be obtained by solving a linear
program and that capacity can be achieved to within a constant gap of
K/2log(4K). This gap may be further decreased by considering more structured
networks such as, for example, the diamond network.


title: Dielectric Fluid in Inhomogeneous Pulsed Electric Field

abstract:
  We consider the dynamics of a compressible fluid under the influence of
electrostrictive ponderomotive forces in strong inhomogeneous nonstationary
electric fields. It is shown that if the fronts of the voltage rise at a sharp,
needle-like electrode are rather steep (less than or about nanoseconds), and
the region of negative pressure arises, which can reach values at which the
fluid loses its continuity with the formation of cavitation ruptures. If the
voltage on the electrode is not large enough or the front is flatter, the
cavitation in the liquid does not occur. However, a sudden shutdown of the
field results in a reverse flow of liquid from the electrode, which leads to
appearance of negative pressure, and, possibly, cavitation.


title: Stochasticity effects in quantum radiation reaction

abstract:
  When an ultrarelativistic electron beam collides with a sufficiently intense
laser pulse, radiation-reaction effects can strongly alter the beam dynamics.
In the realm of classical electrodynamics, radiation reaction has a beneficial
effect on the electron beam as it tends to reduce its energy spread. Here, we
show that when quantum effects become important, radiation reaction induces the
opposite effect, i.e., the electron beam spreads out after interacting with the
laser pulse. We identify the physical origin of this opposite tendency in the
intrinsic stochasticity of photon emission, which becomes substantial in the
full quantum regime. Our numerical simulations indicated that the predicted
effects of the stochasticity can be measured already with presently available
lasers and electron accelerators.


title: Band structure of the Ruelle spectrum of contact Anosov flows

abstract:
  If X is a contact Anosov vector field on a smooth compact manifold M and V is
a smooth function on M, it is known that the differential operator A=-X+V has
some discrete spectrum called Ruelle-Pollicott resonances in specific Sobolev
spaces. We show that for |Im(z)| large the eigenvalues of A are restricted to
vertical bands and in the gaps between the bands, the resolvent of A is bounded
uniformly with respect to |Im(z)|. In each isolated band the density of
eigenvalues is given by the Weyl law. In the first band, most of the
eigenvalues concentrate of the vertical line Re(z)=< D >, the space average of
the function D(x)=V(x)-1/2 div(X)/E_u where Eu is the unstable distribution.
This band spectrum gives an asymptotic expansion for dynamical correlation
functions.


title: Standing waves of the complex Ginzburg-Landau equation

abstract:
  We prove the existence of nontrivial standing wave solutions of the complex
Ginzburg-Landau equation $\phi_t = e^{i\theta} \Delta \phi + e^{i\gamma} |\phi
|^\alpha \phi $ with periodic boundary conditions. Our result includes all
values of $\theta $ and $\gamma $ for which $\cos \theta \cos \gamma >0$, but
requires that $\alpha >0$ be sufficiently small.


title: Coexistence in an inhomogeneous environment

abstract:
  We examine the two-dimensional extension of the model of Kessler and Sander
of competition between two species identical except for dispersion rates. In
this class of models, the spatial inhomogeneity of reproduction rates gives
rise to an implicit cost of dispersal, due to the tendency to leave favorable
locations. Then, as in the Hamilton-May model with its explicit dispersal cost,
the tradeoff between dispersal case and the beneficial role of dispersal in
limiting fluctuations, leads to an advantage of one dispersal rate over
another, and the eventual extinction of the disadvantaged species. In two
dimensions we find that while the competition leads to the elimination of one
species at high and low population density, at intermediate densities the two
species can coexist essentially indefinitely. This is a new phenomenon not
present in either the one-dimensional form of the Kessler-Sander model nor in
the totally connected Hamilton-May model, and points to the importance of
geometry in the question of dispersal.


title:
Phase transitions of dense neutron matter with generalized Skyrme
  interaction to superfluid states with triplet pairing in strong magnetic
  field

abstract:
  A generalized non-relativistic Fermi-liquid approach was used to find
analytical formulas for temperatures $T_{c,1}(n,H)$ and $T_{c,2}(n,H)$ (which
are functions nonlinear of density n and linear of magnetic field H) of phase
transitions in spatially uniform dense pure neutron matter from normal to
superfluid states with spin-triplet p-wave pairing (similar to anisotropic
superfluid phases $^3He-A_{1}$ and $^3He-A_{2}$) in steady and homogeneous
strong magnetic field (but $|\mu_{n}| H\ll E_{c}<\varepsilon_{F}(n)$, where
$\mu_{n}$ is the magnetic dipole moment of a neutron, E_{c} is the cutoff
energy and $\varepsilon_{F}(n)$ is the Fermi energy in neutron matter). General
formulas for $T_{c,1,2}(n,H)$ (valid for arbitrary parametrization of the
effective Skyrme interaction in neutron matter) are specified here for
generalized BSk18 parametrization of the Skyrme forces (with additional terms
dependent on density n) on the interval $0.3\ n_{0}<n<n_{c}(BSk18)\approx
2.7952 n_{0}$, where $n_{0}=0.17{fm}^{-3}$ is nuclear density and at critical
density $n_{c}(BSk18)$ triplet superfluidity disappears,
$T_{c,0}(n_{c},H=0)=0$. Expressions for phase transition temperatures
$T_{c,0}(n)< 0.09 MeV$ (at E_{c}=10 MeV) and $T_{c,1,2}(n,H)$ are realistic
non-monotone functions of density n for BSk18 parametrization of the Skyrme
forces (contrary to their monotone increase for all previous BSk
parameterizations). Phase transitions to superfluid states of such type might
occur in liquid outer core of magnetars (strongly magnetized neutron stars).


title:
Group-invariant solutions of semilinear Schrodinger equations in multi-
  dimensions

abstract:
  Symmetry group methods are applied to obtain all explicit group-invariant
radial solutions to a class of semilinear Schrodinger equations in dimensions
$n\neq 1$. Both focusing and defocusing cases of a power nonlinearity are
considered, including the special case of the conformal power $p=4/n$ relevant
for critical dynamics.The methods involve, firstly, reduction of the semilinear
Schrodinger equations to group-invariant complex 2nd order ODEs with respect to
an optimal set of one-dimensional point symmetry groups, and secondly, use of
inherited symmetries, hidden symmetries, and conditional symmetries to solve
each ODE by quadratures. Through Noether's theorem, all conservation laws
arising from these point symmetry groups are listed.


title:
Landau-Ginzburg/Calabi-Yau correspondence for the complete intersections
  X_{3,3} and X_{2,2,2,2}

abstract:
  We define a generalization of Fan-Jarvis-Ruan-Witten theory, a "hybrid" model
associated to a collection of quasihomogeneous polynomials of the same weights
and degree, which is expected to match the Gromov-Witten theory of the
Calabi-Yau complete intersection cut out by the polynomials. In genus zero, we
prove that the correspondence holds for any such complete intersection of
dimension three in ordinary, rather than weighted, projective space. These
results generalize those of Chiodo-Ruan for the quintic threefold, and as in
that setting, Givental's quantization can be used to yield a conjectural
relation between the full higher-genus theories.


title: First results from a next-generation off-plane X-ray diffraction grating

abstract:
  Future NASA X-ray spectroscopy missions will require high throughput, high
resolution grating spectrometers. Off-plane reflection gratings are capable of
meeting the performance requirements needed to realize the scientific goals of
these missions. We have identified a novel grating fabrication method that
utilizes common lithographic and microfabrication techniques to produce the
high fidelity groove profile necessary to achieve this performance. Application
of this process has produced an initial pre-master that exhibits a radial
(variable line spacing along the groove dimension), high density (>6000
grooves/mm), laminar profile. This pre-master has been tested for diffraction
efficiency at the BESSY II synchrotron light facility and diffracts up to 55%
of incident light into usable spectral orders. Furthermore, tests of spectral
resolving power show that these gratings are capable of obtaining resolutions
well above 1300 ($\lambda/\Delta\lambda$) with limitations due to the test
apparatus, not the gratings. Obtaining these results has provided confidence
that this fabrication process is capable of producing off-plane reflection
gratings for the next generation of X-ray observatories.


title:
Simulation of hydrogen diffusion and boron passivation in crystalline
  silicon

abstract:
  The model of hydrogen migration and of the reactions of hydrogen atoms with
electrically active impurity, developed earlier, has been applied to simulate
hydrogen diffusion and passivation process during plasma deuteration of silicon
substrates doped with boron. The calculated deuterium concentration profiles
agree well in the length of the passivated region with the experimental data
obtained on treatment in hydrogen plasma at a temperature of 200 Celsius
degrees for 5, 10, and 15 minutes. On the other hand, to achieve a good fit to
the abruptness of the calculated profiles between the passivated and
unpassivated regions, it is necessary to suppose that the values of the
parameters that describe the absorption of hydrogen interstitials by
electrically active dopant atoms decrease with increase in the depth of the
passivated region. For example, nonuniform spatial distributions of
nonequilibrium point defects generated during plasma treatment can lead to a
spatial dependence of hydrogen absorption.


title: Localization, metabelian groups, and the isomorphism problem

abstract:
  If G and H are finitely generated, residually nilpotent metabelian groups, H
is termed para-G if there is a homomorphism of G into H which induces an
isomorphism between the corresponding terms of their lower central quotient
groups. We prove that this is an equivalence relation. It is a much coarser
relation than isomorphism, our ultimate concern. It turns out that many of the
groups in a given equivalence class share various properties including finite
presentability. There are examples, such as the lamplighter group, where an
equivalence class consists of a single isomorphism class and others where this
is not the case. We give several examples where we solve the Isomorphism
Problem. We prove also that the sequence of torsion-free ranks of the lower
central quotients of a finitely generated metabelian group is computable. In a
future paper we plan on proving that there is an algorithm to compute the
numerator and denominator of the rational Poincar\'e series of a finitely
generated metabelian group and will carry out this computation in a number of
examples, which may shed a tiny bit of light on the Isomorphism Problem. Our
proofs use localization, class field theory and some constructive commutative
algebra.


title:
Quantum simulation of Kibble-Zurek mechanism with a semiconductor
  electron charge qubit

abstract:
  The Kibble-Zurek mechanism provides a description of the topological
structure occurring in the symmetry breaking phase transitions, which may
manifest as the cosmological strings in the early universe or vortex lines in
the superfulid. A particularly intriguing analogy between Kibble-Zurek
mechanism and a text book quantum phenomenon, Landau-Zener transition has been
discovered, but is difficult to observe up to now. In recent years, there has
been broad interest in quantum simulations using different well-controlled
physical setups, in which full tunability allows access to unexplored parameter
regimes. Here we demonstrate a proof-of-principle quantum simulation of
Kibble-Zurek mechanism using a single electron charge qubit in double quantum
dot, set to behave as Landau-Zener dynamics. We measure the qubit states as a
function of driven pulse velocity and successfully reproduce Kibble-Zurek like
dependence of topological defect density on the quench rate. The high-level
controllability of semiconductor two-level system make it a platform to test
the key elements of topological defect formation process and shed a new insight
on the aspect of non-equilibrium phase transitions.


title:
On the Achievable Rate-Regions for State-Dependent Gaussian Interference
  Channel

abstract:
  In this paper, we study a general additive state-dependent Gaussian
interference channel (ASD-GIC) where we consider two-user interference channel
with two independent states known non-causally at both transmitters, but
unknown to either of the receivers. An special case, where the additive states
over the two links are the same is studied in [1], [2], in which it is shown
that the gap between the achievable symmetric rate and the upper bound is less
than 1/4 bit for the strong interference case. Here, we also consider the case
where each channel state has unbounded variance [3], which is referred to as
the strong interferences. We first obtain an outer bound on the capacity
region. By utilizing lattice-based coding schemes, we obtain four achievable
rate regions. Depend on noise variance and channel power constraint, achievable
rate regions can coincide with the channel capacity region. For the symmetric
model, the achievable sum-rate reaches to within 0.661 bit of the channel
capacity for signal to noise ratio (SNR) greater than one.


title: On the Correlation Between Polarized BECs

abstract:
  We consider the $2^n$ channels synthesized by the $n$-fold application of
Ar\i{}kan's polar transform to a binary erasure channel (BEC). The synthetic
channels are BECs themselves, and we show that, asymptotically for almost all
these channels, the pairwise correlations between their erasure events are
extremely small: the correlation coefficients vanish faster than any
exponential in $n$. Such a fast decay of correlations allows us to conclude
that the union bound on the block error probability of polar codes is very
tight.


title: Playing a quantum game on polarization vortices

abstract:
  The quantum mechanical approach to the well known prisoners dilemma, one of
the basic examples to illustrate the concepts of Game Theory, is implemented
with a classical optical resource, nonquantum entanglement between spin and
orbital degrees of freedom of laser modes. The concept of entanglement is
crucial in the quantum version of the game, which brings novel features with a
richer universe of strategies. As we show, this richness can be achieved in a
quite unexpected context, namely that of paraxial spin-orbit modes in classical
optics.


title: Three-qubit topological phase on entangled photon pairs

abstract:
  We propose an experiment to observe the topological phases associated with
cyclic evolutions, generated by local SU(2) operations, on three-qubit
entangled states prepared on different degrees of freedom of entangled photon
pairs. The topological phases reveal the nontrivial topological structure of
the local SU(2) orbits. We describe how to prepare states showing different
topological phases, and discuss their relation to entanglement. In particular,
the presence of a $\pi/2$ phase shift is a signature of genuine tripartite
entanglement in the sense that it does not exist for two-qubit systems.


title: Fractional topological phase on spatially encoded photonic qudits

abstract:
  We discuss the appearance of fractional topological phases on cyclic
evolutions of entangled qudits encoded on photonic degrees of freedom. We show
how the spatial correlations between photons generated by spontaneous
parametric down conversion can be used to evidence the multiple topological
phases acquired by entangled qudits and the role played by the Hilbert space
dimension. A realistic experimental proposal is presented with numerical
predictions of the expected results.


title: Analogue of surface melting in a macroscopic non-equilibrium system

abstract:
  Agitated wet granular matter can be considered as a nonequilibrium model
system for phase transitions, where the macroscopic particles replace the
molecules and the capillary bridges replace molecular bonds. It is demonstrated
experimentally that a two-dimensional wet granular crystal driven far from
thermal equilibrium melts from its free surface, preceded by an amorphous
state. The transition into the surface melting state, as revealed by the bond
orientational order parameters, behaves like a first order phase transition,
with a threshold being traceable to the rupture energy of a single capillary
bridge. The observation of such a transition in the macroscopic nonequilibrium
system triggers the question of the universality of surface melting.


title:
A single diffractive optical element for implementing spectrum-splitting
  and beam-concentration functions simultaneously with high diffraction
  efficiency

abstract:
  In this paper, a novel method is proposed, and employed to design a single
diffractive optical element (DOE) for implementing spectrum-splitting and
beam-concentration (SSBC) functions simultaneously. We develop an optimization
algorithm, through which the SSBC DOE can be optimized within an arbitrary
thickness range, according to the limitations of modern photolithography
technology. Theoretical simulation results reveal that the designed SSBC DOE
has a high optical focusing efficiency. It is expected that the designed SSBC
DOE should have practical applications in high-efficiency solar cell systems.


title:
Superconductivity of interface layer at contact between normal metal and
  high temperature superconductor

abstract:
  In this research, it is shown that there are the necessary physical
conditions to originate the returning superconductivity in the thin interface
layer at the contact between the normal metal and the high temperature
superconductor (N-S contact). The influences by the temperature T, magnetic
field H and direct current I on the electrical resistance RG of the thin
interface layer G in the multilayered system N-G-S, where N can be one the
normal metal layers of Argentum (Ag), Indium (In), Gallium-Indium (Ga-50%In), G
is the thin interface layer, S is the high temperature superconductor (HTS)
layer of YBa2Cu3O7-x, are researched experimentally.

categories: cond-mat.supr-con cond-mat.mtrl-sci cond-mat.other physics.ins-det


title: Non-minimal Higgs Inflation and Frame Dependence in Cosmology

abstract:
  We investigate a very general class of cosmological models with scalar fields
non-minimally coupled to gravity. A particular representative in this class is
given by the non-minimal Higgs inflation model in which the Standard Model
Higgs boson and the inflaton are described by one and the same scalar particle.
While the predictions of the non-minimal Higgs inflation scenario come
numerically remarkably close to the recently discovered mass of the Higgs
boson, there remains a conceptual problem in this model that is associated with
the choice of the cosmological frame. While the classical theory is independent
of this choice, we find by an explicit calculation that already the first
quantum corrections induce a frame dependence. We give a geometrical
explanation of this frame dependence by embedding it into a more general field
theoretical context. From this analysis, some conceptional points in the long
lasting cosmological debate: "Jordan frame vs. Einstein frame" become more
transparent and in principle can be resolved in a natural way.


title: Space-Times with Integrable Singularity

abstract:
  We use the phenomenological approach to study properties of space-time in the
vicinity of the Schwarzschild black-hole singularity. Requiring finiteness of
the Schwarzschild-like metrics we come to the notion of integrable singularity
that is, in a sense, weaker than the conventional singularity and allows the
(effective) matter to pass to the white-hole region. This leads to a
possibility of generating a new universe there. Thanks to the gravitational
field of the singularity, this universe is already born highly inflated
('singularity-induced inflation') before the ordinary inflation starts.


title:
Time/Computationally Optimal Network Architecture: Wireless Sensor
  Fusion

abstract:
  In this research paper, the problems dealing with sensor network
architecture, sensor fusion are addressed. Time/Computationally optimal network
architectures are investigated. Some novel ideas on sensor fusion are proposed.


title: Dynamics of Bloch oscillating transistor near bifurcation threshold

abstract:
  Tendency to bifurcate can often be utilized to improve performance
characteristics of amplifiers or even to build detectors. Bloch oscillating
transistor is such a device. Here we show that bistable behaviour can be
approached by tuning the base current and that the critical value depends on
the Josephson coupling energy $E_J$ of the device. We demonstrate record-large
current gains for device operation near the bifurcation point at small $E_J$.
From our results for the current gains at various $E_J$, we determine the
bifurcation threshold on the $E_J$ - base current plane. The bifurcation
threshold curve can be understood using the interplay of inter- and intra-band
tunneling events.


title:
Determination of photodissociation and radiative association cross
  sections from the same time-dependent calculation

abstract:
  We illustrate some of the difficulties that may be encountered when computing
photodissociation and radiative association cross sections from the same
time-dependent approach based on wavepacket propagation. The total and partial
photodissociation cross sections from the thirty-three vibrational levels of
the b triplet {\Sigma}+ state of HeH+ towards the 9 other triplet {\Sigma}+ and
6 triplet {\Pi} n = 2, 3 higher-lying electronic states are calculated. The
corresponding radiative association cross sections are extracted from the same
calculations, and the photodissociation and radiative association rate
constants are determined.


title: Scaling of the normal coefficient of restitution for wet impacts

abstract:
  A thorough understanding of the energy dissipation in the dynamics of wet
granular matter is essential for a continuum description of natural phenomena
such as debris flow, and the development of various industrial applications
such as the granulation process. The coefficient of restitution (COR), defined
as the ratio between the relative rebound and impact velocities of a binary
impact, is frequently used to characterize the amount of energy dissipation
associated. We measure the COR by tracing a freely falling sphere bouncing on a
wet surface with the liquid film thickness monitored optically. For fixed ratio
between the film thickness and the particle size, the dependence of the COR on
the impact velocity and various properties of the liquid film can be
characterized with the Stokes number, defined as the ratio between the inertia
of the particle and the viscosity of the liquid. Moreover, the COR for
infinitely large impact velocities derived from the scaling can be analyzed by
a model considering the energy dissipation from the inertia of the liquid film.


title: Hydrodynamic fluctuations in confined emulsions

abstract:
  When an ensemble of particles interact hydrodynamically, they generically
display large-scale transient structures such as swirls in sedimenting
particles [1], or colloidal strings in sheared suspensions [2]. Understanding
these nonequilibrium fluctuations is a very difficult problem, yet they are of
great importance for a wide range of processes including pigment deposition in
cosmetic or paint films, the transport of microfluidic droplets, ... All these
samples concern rigidly confined fluids, which we consider in this paper. We
address the collective dynamics of non-Brownian droplets cruising in a shallow
microchannel. We provide a comprehensive characterization of their
spatiotemporal density fluctuations. We show that density excitations freely
propagate at all scales, and in all directions even though the particles are
neither affected by potential forces nor by inertia. We introduce a theory
which quantitatively accounts for our experimental findings. By doing so we
demonstrate that the fluctuation spectrum of this nonequilibrium system is
shaped by the combination of truly long-range hydrodynamic interactions and
local collisions.


title: Dynamics of rotating spirals in agitated wet granular matter

abstract:
  Pattern formation of a thin layer of vertically agitated wet granular matter
is investigated experimentally. Due to the strong cohesion arising from the
capillary bridges formed between adjacent particles, agitated wet granular
matter exhibits a different scenario compared with cohesionless dry particles.
Rotating spirals with three arms, which correspond to the kinks between regions
with different colliding phases with the vibrating plate, have been found to be
the dominating pattern. From both top view snapshots and laser profilometry
methods, the rotation frequency of the spiral arms is characterized with image
processing procedures. Both methods reveal that there exists a finite rotation
frequency $\nu_{\rm r}$ at a threshold vibration acceleration, above which
$\nu_{\rm r}$ increases linearly with the peak vibration acceleration with a
slope strongly dependent on the vibration frequency.


title: The diffeomorphism group of a non-compact orbifold

abstract:
  We endow the diffeomorphism group of a paracompact (reduced) orbifold with
the structure of an infinite dimensional Lie group modelled on the space of
compactly supported sections of the tangent orbibundle. For a second countable
orbifold, we prove that this Lie group is C^0-regular and thus regular in the
sense of Milnor. Furthermore an explicit characterization of the Lie algebra
associated to the diffeomorphism group of an orbifold is given.


title:
Microscopic analysis of sub-barrier fusion enhancement in
  $^{132}$Sn+$^{40}$Ca vs. $^{132}$Sn+$^{48}$Ca}

abstract:
  We provide a theoretical analysis of recently measured fusion cross sections
which show a surprising enhancement at low $E_\mathrm{c.m.}$ energies for the
system $^{132}$Sn+$^{40}$Ca as compared to the more neutron-rich system
$^{132}$Sn+$^{48}$Ca. Dynamic microscopic calculations are carried out on a
three-dimensional lattice with a time-dependent density-constrained density
functional theory. There are no adjustable parameters, the only input is the
Skyrme effective NN interaction. Heavy-ion potentials $V(R)$,
coordinate-dependent mass parameters $M(R)$, and total fusion cross sections
$\sigma(E_\mathrm{c.m.})$ are calculated for both systems. We are able to
explain the measured fusion enhancement in terms of the {\it narrower width} of
the ion-ion potential for $^{132}$Sn+$^{40}$Ca, while the barrier heights and
positions are approximately the same in both systems.


title: Reservoir-engineered entanglement in optomechanical systems

abstract:
  We show how strong steady-state entanglement can be achieved in a three-mode
optomechanical system (or other parametrically-coupled bosonic system) by using
one of the modes as a cold reservoir to effectively laser-cool a delocalized
Bogoliubov mode. This approach allows one to surpass the bound on the maximum
stationary intracavity entanglement possible with a coherent two-mode squeezing
interaction. Unlike typical dissipative entanglement schemes, the entangling
dynamics here are most effective in a regime where the effects of the
engineered reservoir cannot be described by a Markovian Lindblad master
equation.


title: Classical bifurcation in a quadrupolar NMR system

abstract:
  The Josephson Junction model is applied to the experimental implementation of
classical bifurcation in a quadrupolar Nuclear Magnetic Resonance system. There
are two regimes, one linear and one nonlinear which are implemented by the
radio-frequency term and the quadrupolar term of the Hamiltonian of a spin
system respectively. Those terms provide an explanation of the symmetry
breaking due to bifurcation. Bifurcation depends on the coexistence of both
regimes at the same time in different proportions. The experiment is performed
on a lyotropic liquid crystal sample of an ordered ensemble of $^{133}$Cs
nuclei with spin $I=7/2$ at room temperature. Our experimental results confirm
that bifurcation happens independently of the spin value and of the physical
system. With this experimental spin scenario, we confirm that a quadrupolar
nuclei system could be described analogously to a symmetric two--mode
Bose--Einstein condensate.


title:
Comparison of the moments of the Xmax distribution predicted by
  different cosmic ray shower simulation models

abstract:
  In this paper we study the depth at which a cosmic ray shower reaches its
maximum (\Xmax) as predicted by Monte Carlo simulation. The use of \Xmax in the
determination of the primary particle mass can only be done by comparing the
measured values with simulation predictions. For this reason it is important to
study the differences between the available simulation models. We have done a
study of the first and second moments of the \Xmax distribution using the
\Corsika and \Conex programs. The study was done with high statistics in the
energy range from $10^{17}$ to \energy{20.4}. We focus our analysis in the
different implementations of the hadronic interaction models \Sibyll and
\Qgsjet in \Corsika and \Conex. We show that the predictions of the \meanXmax
and \sigmaXmax depend slightly on the combination of simulation program and
hadronic interaction model. Although these differences are small, they are not
negligible in some cases (up to 5 g/cm$^2$ for the worse case) and they should
be considered as a systematic uncertainty of the model predictions for
\meanXmax and \sigmaXmax. We have included a table with the suggested
systematic uncertainties for the model predictions. Finally, we present a
parametrization of the \Xmax distribution as a function of mass and energy
according to the models \Sibyll and \Qgsjet, and showed an example of its
application to obtain the predicted \Xmax distributions from cosmic ray
propagation models.


title:
Unconventional Superconductivity from Local Spin Fluctuations in the
  Kondo Lattice

abstract:
  The explanation of heavy-fermion superconductivity is a long-standing
challenge to theory. It is commonly thought to be connected to non-local
fluctuations of either spin or charge degrees of freedom and therefore of
unconventional type. Here we present results for the Kondo-lattice model, a
paradigmatic model to describe heavy-fermion compounds, obtained from dynamical
mean-field theory which captures local correlation effects only. Unexpectedly,
we find robust s-wave superconductivity in the heavy-fermion state. We argue
that this novel type of pairing is tightly connected to the formation of heavy
quasiparticle bands and the presence of strong local spin fluctuations.


title:
First LHC results on coherent J/psi photoproduction in ultra-peripheral
  Pb-Pb collisions at sqrt{s_NN} = 2.76 TeV

abstract:
  The first LHC measurement on ultra-peripheral heavy-ion collisions was
carried out with the ALICE experiment. In this paper, ALICE results on
exclusive J/psi studies in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV, in the
rapidity region -3.6 < y < -2.6, are given. The coherent J/psi cross section
was found to be dsigma/dy_coh_J/\psi = 1.00 +/- 0.18 (stat) +0.24 -0.26 (syst)
mb. These studies favour theoretical models that include strong modifications
to the nuclear gluon density, also known as nuclear gluon shadowing.


title: Different representations of the Levi-Civita Bertotti Robinson solution

abstract:
  The Levi-Civita Bertotti Robinson (LBR) spacetime is investigated in various
coordinate systems. By means of a general formalism for constructing
coordinates in conformally flat spacetimes, coordinate transformations between
the different coordinate systems are deduced. We discuss the motion of the
reference frames in which the different coordinate systems are comoving.
Furthermore we characterize the motion of the different reference frames by
their normalized timelike Killing vector fields, i.e. by the four velocity
fields of the reference particles. We also deduce the formulae in the different
coordinate systems for the embedding of the LBR spacetime in a flat
6-dimensional manifold. In particular we discuss a scenario with a spherical
domain wall having LBR spacetime outside the wall and flat spacetime inside. We
also discuss the internal flat spacetime using the same coordinate systems as
in the external LBR spacetime with continuous metric at the wall. Among the
different cases one represents a Milne-LBR universe model with a part of the
Milne universe inside the wall and an infinitely extended LBR universe outside
it. In an appendix we define combinations of trigonometric and hyperbolic
functions that we call k-functions and present a new k-function calculus.


title: Cosmic radio dipole from NVSS and WENSS

abstract:
  We use linear estimators to determine the magnitude and direction of the
cosmic radio dipole from the NRAO VLA Sky Survey (NVSS) and the Westerbork
Northern Sky Survey (WENSS). We show that special attention has to be given to
the issues of bias due to shot noise, incomplete sky coverage and masking of
the Milky Way. We compare several different estimators and show that
conflicting claims in the literature can be attributed to the use of different
estimators. We find that the NVSS and WENSS estimates of the cosmic radio
dipole are consistent with each other and with the direction of the cosmic
microwave background (CMB) dipole. We find from the NVSS a dipole amplitude of
$(1.6 \pm 0.6) \times 10^{-2}$ in direction $(\mathrm{RA}, \mathrm{dec})=
(154^\circ \pm 21^\circ, -2^\circ \pm 21^\circ)$. This amplitude exceeds the
one expected from the CMB by a factor of about 3 and is inconsistent with the
assumption of a pure kinetic origin of the radio dipole at 99.5% CL.


title: Simple ambiskew polynomial rings

abstract:
  We determine simplicity criteria in characteristics 0 and $p$ for a
ubiquitous class of iterated skew polynomial rings in two indeterminates over a
base ring. One obstruction to simplicity is the possible existence of a
canonical normal element $z$. In the case where this element exists we give
simplicity criteria for the rings obtained by inverting $z$ and the rings
obtained by factoring out the ideal generated by $z$. The results are
illustrated by numerous examples including higher quantized Weyl algebras and
generalizations of some low-dimensional symplectic reflection algebras.


title: Cavity beam position monitor system for the Accelerator Test Facility 2

abstract:
  The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for
final focus beam lines of linear high energy colliders. This paper describes
the high resolution cavity beam position monitor (BPM) system, which is a part
of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at
6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The
cavities, electronics, and digital processing are described. The resolution of
the C-band system with attenuators was determined to be approximately 250 nm
and 1 m for the S-band system. Without attenuation the best recorded C-band
cavity resolution was 27 nm.


title: The Elemental Compositions of Extrasolar Planetesimals

abstract:
  Evidence is now compelling that most externally-polluted white dwarfs derive
their heavy atoms by accretion from asteroids - the building blocks of rocky
planets. Optical and ultraviolet spectroscopy of a small sample of suitable
white dwarf stars shows that to zeroth order, the accreted extrasolar parent
bodies compositionally resemble bulk Earth. (1) Extrasolar planetesimals are at
least 85% by mass composed of O, Mg, Si and Fe. (2) Compared to the Sun, C is
often deficient, usually by at least a factor of 10 and therefore comprises
less than 1% of an extrasolar planetesimal's mass. At least to-date, C has
never been found to be enhanced as would be expected if carbon-rich
planetesimals have formed. (3) While there may be individual exceptions,
considered as a whole, the population of extrasolar asteroids accreted onto a
well-defined sample of local white dwarf stars is less than 1% water by mass.


title: The Penrose-Fife phase-field model with dynamic boundary conditions

abstract:
  In this paper we derive, starting from the basic principles of
Thermodynamics, an extended version of the nonconserved Penrose-Fife phase
transition model, in which dynamic boundary conditions are considered in order
to take into account interactions with walls. Moreover, we study the
well-posedness and the asymptotic behavior of the Cauchy problem for the PDE
system associated to the model, allowing the phase configuration of the
material to be described by a singular function.


title:
Comment on "First-principles study of the influence of (110)-oriented
  strain on the ferroelectric properties of rutile TiO2" [arXiv:1106.2820]

abstract:
  In a recent article, Gr\"{u}nebohm et al. [Phys. Rev. B 84 132105 (2011),
arXiv:1106.2820] report that they fail to reproduce the A2u ferroelectric
instability of TiO2 in the rutile structure calculated with density functional
theory within the PBE-GGA approximation by Montanari et al. [Chem. Phys. Lett
364, 528 (2002)]. We demonstrate that this disagreement arises from an
erroneous treatment of Ti 3s and 3p semi-core electrons as core in their
calculations. Fortuitously the effect of the frozen semi-core pseudopotential
cancels the phonon instability of the PBE exchange-correlation, and the
combination yields phonon frequencies similar to the LDA harmonic values.
  Gr\"{u}nebohm et al. also attempted and failed to reproduce the soft acoustic
phonon mode instability under (110) strain reported by Mitev et al. [Phys. Rev.
B 81 134303 (2010)]. For this mode the combination of PBE-GGA and frozen
semi-core yields a small imaginary frequency of 9.8i. The failure of
Gr\"{u}nebohm et al. to find this mode probably arose from numerical
limitations of the geometry optimization approach in the presence of a shallow
double well potential; the optimization method is not suitable for locating
such instabilities.


title:
Infinitesimal Torelli theorem for cyclic coverings of generalized flag
  varieties I

abstract:
  We give an effective infinitesimal Torelli theorem for cyclic covers of G/P,
where G is a simple algebraic group and P is a maximal parabolic subgroup.


title:
A remark on the ultra-analytic smoothing properties of the spatially
  homogeneous Landau equation

abstract:
  We consider the non-linear spatially homogeneous Landau equation with
Maxwellian molecules in a close-to-equilibrium framework and show that the
Cauchy problem for the fluctuation around the Maxwellian equilibrium
distribution enjoys a Gelfand-Shilov regularizing effect implying the
ultra-analyticity of both the fluctuation and its Fourier transform for any
positive time.


title:
Gas infall into atomic cooling haloes: on the formation of protogalactic
  disks and supermassive black holes at z > 10

abstract:
  We have performed cosmo-hydro simulations using the RAMSES code to study
atomic cooling (ACHs) haloes at z=10 with masses 5E7Msun<~M<~2E9Msun. We assume
primordial gas and H2-cooling and prior star-formation have been suppressed. We
analysed 19 haloes (gas and DM) at a resolution of ~10 (proper) pc, selected
from a total volume of ~2E3 (comoving) Mpc3. This is the largest statistical
hydro-sim. study of ACHs at z>10 to date. We examine the morphology, angular
momentum (AM), thermodynamic, and turbulence of these haloes, in order to
assess the prevalence of disks and supermassive black holes (SMBHs). We find no
correlation between either the magnitude or the direction of the AM of the gas
and its parent DM halo. Only 3 haloes form rotationally supported cores. Two of
the most massive haloes form massive, compact overdense blobs. These blobs have
an accretion rate ~0.5 Msun/yr (at a distance of 100 pc), and are possible
sites of SMBH formation. Our results suggest that the degree of rotational
support and the fate of the gas in a halo is determined by its large-scale
environment and merger history. In particular, the two haloes forming blobs are
located at knots of the cosmic web, cooled early on, and experienced many
mergers. The gas in these haloes is lumpy and highly turbulent, with Mach N. >~
5. In contrast, the haloes forming rotationally supported cores are relatively
more isolated, located midway along filaments, cooled more recently, and
underwent fewer mergers. Thus, the gas in these haloes is less lumpy and less
turbulent (Mach <~ 4), and could retain most of its AM. The remaining 14 haloes
have intermediate properties. If verified in a larger sample of haloes and with
additional physics, our results will have implications for observations of the
highest-redshift galaxies and quasars with JWST.


title:
A model-free version of the fundamental theorem of asset pricing and the
  super-replication theorem

abstract:
  We propose a Fundamental Theorem of Asset Pricing and a Super-Replication
Theorem in a model-independent framework. We prove these theorems in the
setting of finite, discrete time and a market consisting of a risky asset S as
well as options written on this risky asset. As a technical condition, we
assume the existence of a traded option with a super-linearly growing
payoff-function, e.g., a power option. This condition is not needed when
sufficiently many vanilla options maturing at the horizon T are traded in the
market.


title: Inelastic electron transport through molecular junctions

abstract:
  Currently, molecular tunnel junctions are recognized as important active
elements of various nanodevices. This gives a strong motivation to study
physical mechanisms controlling electron transport through molecules. Electron
motion through a molecular bridge is always somewhat affected by the
environment, and the interactions with the invironment could change the energy
of the traveling electron. Under certain conditions these inelastic effects may
significantly modify electron transport characteristics. In the present work we
describe inelastic and dissipative effects in the electron transport occurring
due to the molecular bridge vibrations and stochastic thermally activated ion
motions. We intentionally use simple models and computational techniques to
keep a reader focused on the physics of inelastic electron transport in
molecular tunnel junctions. We consider electron-vibron interactions and their
manifestations in the inelastic tunneling spectra, polaronic effects and
dissipative electron transport. Also, we briefly discuss long-range electron
transfer reactions in macromolecules and their relation to the electron
transport through molecular junctions.


title: Remarks on the Einstein-Euler-Entropy system

abstract:
  We prove short-time existence for the Einstein-Euler-Entropy system for
non-isentropic fluids with data in uniformly local Sobolev spaces. The cases of
compact as well as non-compact Cauchy surfaces are covered. The method employed
uses a Lagrangian description of the fluid flow which is based on techniques
developed by Friedrich, hence providing a completely different proof of earlier
results of Choquet-Bruhat and Lichnerowicz. This new proof is specially suited
for applications to self-gravitating fluid bodies.


title: Atmospheric composition of weak G band stars: CNO and Li abundances

abstract:
  We determined the chemical composition of a large sample of weak G band stars
-- a rare class of G and K giants of intermediate mass with unusual abundances
of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J.
Smith Telescope at the McDonald Observatory and derived spectroscopic
abundances for C, N, O, and Li, as well as for selected elements from Na - Eu.
The results show that the atmospheres of weak G band stars are highly
contaminated with CN-cycle products. The C underabundance is about a factor of
20 larger than for normal giants and the $^{12}$C/$^{13}$C ratio approaches the
CN-cycle equilibrium value. In addition to the striking CN-cycle signature the
strong N overabundance may indicate the presence of partially ON-cycled
material in the atmospheres of the weak G band stars. The exact mechanism
responsible for the transport of the elements to the surface has yet to be
identified but could be induced by rapid rotation of the main sequence
progenitors of the stars. The unusually high Li abundances in some of the stars
are an indicator for Li production by the Cameron-Fowler mechanism. A
quantitative prediction of a weak G band star's Li abundance is complicated by
the strong temperature sensitivity of the mechanism and its participants. In
addition to the unusual abundances of CN-cycle elements and Li we find an
overabundance of Na that is in accordance with the NeNa chain running in
parallel with the CN-cycle. Apart from these peculiarities the element
abundances in a weak G band star's atmosphere are consistent with those of
normal giants.


title: Essential Magnetohydrodynamics for Astrophysics

abstract:
  This text is intended as an introduction to magnetohydrodynamics in
astrophysics, emphasizing a fast path to the elements essential for physical
understanding. It assumes experience with concepts from fluid mechanics: the
fluid equation of motion and the Lagrangian and Eulerian descriptions of fluid
flow. In addition, the basics of vector calculus and elementary special
relativity are needed. Not much knowledge of electromagnetic theory is
required. In fact, since MHD is much closer in spirit to fluid mechanics than
to electromagnetism, an important part of the learning curve is to overcome
intuitions based on the vacuum electrodynamics of one's high school days. The
first chapter (only 39 pp) is meant as a practical introduction including
exercises. This is the `essential' part. The exercises are important as
illustrations of the points made in the text (especially the less intuitive
ones). Almost all are mathematically unchallenging. The supplement in chapter 2
contains further explanations, more specialized topics and connections to the
occasional topic somewhat outside MHD. The emphasis is on physical
understanding by the visualization of MHD processes, as opposed to more formal
approaches.