title: NLSE for quantum plasmas with the radiation damping

abstract:
  We consider contribution of the radiation damping in the quantum hydrodynamic
equations for spinless particles. We discuss possibility of obtaining of
corresponding non-linear Schrodinger equation (NLSE) for the macroscopic wave
function. We compare contribution of the radiation damping with weakly (or
semi-) relativistic effects appearing in the second order by v/c. The radiation
damping appears in the third order by v/c. So it might be smaller than weakly
relativistic effects, but it gives damping of the Langmuir waves which can be
considerable.


title:
The visibility of Lyman Alpha Emitters: constraining reionization,
  ionizing photons and dust

abstract:
  We build a physical model for high-redshift Lyman Alpha emitters (LAEs) by
coupling state of the art cosmological simulations (GADGET-2) with a dust model
and a radiative transfer code (pCRASH). We post-process the cosmological
simulation with pCRASH using five different values of the escape fraction of
hydrogen ionizing photons (f_esc=0.05,0.25,0.5,0.75,0.95) until reionization is
complete, i.e. the average neutral hydrogen fraction drops to <X_HI>~10^-4.
Then, the only free-parameter left to match model results to the observed Lya
and UV luminosity functions of LAEs at z~6.6 is the relative escape of Lyman
Alpha (Lya) and continuum photons from the galactic environment (f_alpha/f_c).
We find a three-dimensional degeneracy such that the theoretical model can be
reconciled with observations for an IGM Lya transmission <T_alpha>_LAE~38-50%
(which translates to <X_HI>~0.5-10^-4 for Gaussian emission lines),
f_esc~0.05-0.50 and f_alpha/f_c~0.6-1.8.


title:
Measurement of the production cross section of prompt J/psi mesons in
  association with a W boson in pp collisions at sqrt{s}=7 TeV with the ATLAS
  detector

abstract:
  The process pp--> W + J/psi provides a powerful probe of the production
mechanism of charmonium in hadronic collisions, and is also sensitive to
multiple parton interactions in the colliding protons. Using the 2011 ATLAS
dataset of 4.5 fb-1 of sqrt{s} = 7 TeV pp collisions at the LHC, the first
observation is made of the production of W + prompt J/psi events in hadronic
collisions, using W-->mu+nu and J/psi-->mu+mu. A yield of 27.4+7.5-6.5 W +
prompt J/psi events is observed, with a statistical significance of 5.1 sigma.
The production rate as a ratio to the inclusive W boson production rate is
measured, and the double parton scattering contribution to the cross section is
estimated.


title:
Principal trend analysis for time-course data with applications in
  genomic medicine

abstract:
  Time-course high-throughput gene expression data are emerging in genomic and
translational medicine. Extracting interesting time-course patterns from a
patient cohort can provide biological insights for further clinical research
and patient treatment. We propose principal trend analysis (PTA) to extract
principal trends of time-course gene expression data from a group of patients,
and identify genes that make dominant contributions to the principal trends.
Through simulations, we demonstrate the utility of PTA for dimension reduction,
time-course signal recovery and feature selection with high-dimensional data.
Moreover, PTA derives new insights in real biological and clinical research. We
demonstrate the usefulness of PTA by applying it to longitudinal gene
expression data of a circadian regulation system and burn patients. These
applications show that PTA can extract interesting time-course trends with
biological significance, which helps the understanding of biological mechanisms
of circadian regulation systems as well as the recovery of burn patients.
Overall, the proposed PTA approach will benefit the genomic medicine research.
Our method is implemented into an R-package: PTA (Principal Trend Analysis).


title:
Laser-Nucleus Reactions: Population of States far above Yrast and far
  from Stability

abstract:
  Nuclear reactions induced by a strong zeptosecond laser pulse are studied
theoretically in the quasiadiabatic regime where the photon absorption rate is
comparable to the nuclear equilibration rate. We find that multiple photon
absorption leads to the formation of a compound nucleus in the so-far
unexplored regime of excitation energies several hundred MeV above the yrast
line. At these energies, further photon absorption is limited by neutron decay
and/or induced nucleon emission. With a laser pulse of $\approx 50$ zs
duration, proton-rich nuclei far off the line of stability are produced.


title: Dust reverberation-mapping of the Seyfert 1 galaxy WPVS48

abstract:
  Using robotic telescopes of the Universitatssternwarte Bochum near Cerro
Armazones in Chile, we monitored the z=0.0377 Seyfert 1 galaxy WPVS48 (2MASX
J09594263-3112581) in the optical (B and R) and near-infrared (NIR, J and Ks)
with a cadence of two days. The light curves show unprecedented variability
details. The NIR variation features of WPVS48 are consistent with the
corresponding optical variations, but the features appear sharper in the NIR
than in the optical, suggesting that the optical photons undergo multiple
scatterings. The J and Ks emission, tracing the hot (1600 K) dust echo, lags
the B and R variations by on average 64 +/- 4 days and 71 +/- 5 days,
respectively (restframe). WPVS48 lies on the known tau-M_V relationship.
However, the observed lag is about three times shorter than expected from the
dust sublimation radius r_sub inferred from the optical-UV luminosity, and
explanations for this common discrepancy are searched for. The sharp NIR echos
argue for a face-on torus geometry and allow us to put forward two potential
scenarios: 1) as previously proposed, in the equatorial plane of the accretion
disk the inner region of the torus is flattened and may come closer to the
accretion disk. 2) The dust torus with inner radius r_sub is geometrically and
optically thick, so that the observer only sees the facing rim of the torus
wall, which lies closer to the observer than the torus equatorial plane and
therefore leads to an observed foreshortened lag. Both scenarios are able to
explain the factor three discrepancy between tau and r_sub. Longer-wavelength
dust reverberation data might enable one to distinguish between the scenarios.


title:
Ramsey for $\mathcal{R}_{1}$ ultrafilter mappings and their Dedekind
  cuts

abstract:
  Associated to each ultrafilter $\mathcal{U}$ on $\omega$ and each map
$p:\omega\rightarrow \omega$ is a Dedekind cut in the ultrapower
$\omega^{\omega}/p( \mathcal{U})$. Blass has characterized, under CH, the cuts
obtainable when $\mathcal{U}$ is taken to be either a p-point ultrafilter, a
weakly-Ramsey ultrafilter or a Ramsey ultrafilter.
  Dobrinen and Todorcevic have introduced the topological Ramsey space
$\mathcal{R}_{1}$. Associated to the space $\mathcal{R}_{1}$ is a notion of
Ramsey ultrafilter for $\mathcal{R}_{1}$ generalizing the familiar notion of
Ramsey ultrafilter on $\omega$. We characterize, under CH, the cuts obtainable
when $\mathcal{U}$ is taken to be a Ramsey for $\mathcal{R}_{1}$ ultrafilter
and $p$ is taken to be any map. In particular, we show that the only cut
obtainable is the standard cut, whose lower half consists of the collection of
equivalence classes of constants maps.
  Forcing with $\mathcal{R}_{1}$ using almost-reduction adjoins an ultrafilter
which is Ramsey for $\mathcal{R}_{1}$. For such ultrafilters $\mathcal{U}_{1}$,
Dobrinen and Todorcevic have shown that the Rudin-Keisler types of the p-points
within the Tukey type of $\mathcal{U}_{1}$ consists of a strictly increasing
chain of rapid p-points of order type $\omega$. We show that for any
Rudin-Keisler mapping between any two p-points within the Tukey type of
$\mathcal{U}_{1}$ the only cut obtainable is the standard cut. These results
imply existence theorems for special kinds of ultrafilters.


title: Notes on additively divisible commutative semirings

abstract:
  Commutative semirings with divisible additive semigroup are studied. We show
that an additively divisible commutative semiring is idempotent, provided that
it is finitely generated and torsion. In case that a one-generated additively
divisible semiring posseses no unit, it must contain an ideal of idempotent
elements. We also present a series of open questions about finitely generated
commutative semirings and their equivalent versions.


title: Accurate phase diagram of tetravalent DNA nanostars

abstract:
  We evaluate, by means of molecular dynamics simulations employing a realistic
DNA coarse-grained model, the phase behaviour and the structural and dynamic
properties of tetravalent DNA nanostars, i.e. nanoconstructs completely made of
DNA. We find that, as the system is cooled down, tetramers undergo a
gas--liquid phase separation in a region of concentrations which, if the
difference in salt concentration is taken into account, is comparable with the
recently measured experimental phase diagram [S. Biffi \textit{et al}, Proc.
Natl. Acad. Sci, \textbf{110}, 15633 (2013)]. We also present a mean-field free
energy for modelling the phase diagram based on the bonding contribution,
derived by Wertheim in its studies of associating liquids, combined with mass
action law expressions appropriate for DNA binding and a numerically evaluated
reference free energy. The resulting free energy qualitatively reproduces the
numerical data. Finally, we report information on the nanostar structure, e.g.
geometry and flexibility of the single tetramer and of the collective
behaviour, providing a useful reference for future small angle scattering
experiments, for all investigated temperatures and concentrations.


title: GPS-ABC: Gaussian Process Surrogate Approximate Bayesian Computation

abstract:
  Scientists often express their understanding of the world through a
computationally demanding simulation program. Analyzing the posterior
distribution of the parameters given observations (the inverse problem) can be
extremely challenging. The Approximate Bayesian Computation (ABC) framework is
the standard statistical tool to handle these likelihood free problems, but
they require a very large number of simulations. In this work we develop two
new ABC sampling algorithms that significantly reduce the number of simulations
necessary for posterior inference. Both algorithms use confidence estimates for
the accept probability in the Metropolis Hastings step to adaptively choose the
number of necessary simulations. Our GPS-ABC algorithm stores the information
obtained from every simulation in a Gaussian process which acts as a surrogate
function for the simulated statistics. Experiments on a challenging realistic
biological problem illustrate the potential of these algorithms.


title: Entanglement entropy for non-zero genus topologies

abstract:
  Over the last three decades entanglement entropy has been obtained for
quantum fields propagating in genus zero topologies (Spheres). For scalar
fields propagating in these topologies, it has been shown that the entanglement
entropy scales as area. In the last few years non-trivial topologies are
increasingly relevant for different areas. For instance, in describing quantum
phases, it has been realized that long-range entangled states are described by
topological order. If quantum entanglement can plausibly provide explanation
for these, it then imperative to obtain entanglement entropy in these
topologies. In this work, using two different methods, we explicitly show that
the entanglement entropy scales as area of the genus-1 geometry.


title: Reversibility of laser filamentation

abstract:
  We investigate the reversibility of laser filamentation, a self-sustained,
non-linear propagation regime including dissipation and time-retarded effects.
We show that even losses related to ionization marginally affect the
possibility of reverse propagating ultrashort pulses back to the initial
conditions, although they make it prone to finite-distance blow-up susceptible
to prevent backward propagation.


title: Fatou-Bieberbach domains in $\mathbb C^n\setminus\mathbb R^k$

abstract:
  We construct Fatou-Bieberbach domains in $\mathbb C^n$ for $n>1$ which
contain a given compact set $K$ and at the same time avoid a totally real
affine subspace $L$ of dimension $<n$, provided that $K\cup L$ is polynomially
convex. By using this result, we show that the domain $\mathbb
C^n\setminus\mathbb R^k$ for $1\le k<n$ enjoys the Oka property with
approximation for maps from any Stein manifold of dimension $<n$.


title: Carleman approximation by holomorphic automorphisms of $\mathbb C^n$

abstract:
  We approximate smooth maps defined on non-compact totally real manifolds by
holomorphic automorphisms of $\mathbb C^n$.


title:
A theory of the strain-dependent critical field in Nb3Sn, based on
  anharmonic phonon generation

abstract:
  We propose a theory to explain the strain dependence of the critical
properties in A15 superconductors. Starting from the strong-coupling formula
for the critical temperature, and assuming that the strain sensitivity stems
mostly from the electron-phonon alpha^2F function, we link the strain
dependence of the critical properties to a widening of alpha^2F. This widening
is attributed to the nonlinear generation of phonons, which takes place in the
anharmonic deformation potential induced by the strain. Based on the theory of
sum- and difference-frequency wave generation in nonlinear media, we obtain an
explicit connection between the widening of alpha^2F and the anharmonic energy.
The resulting model is fit to experimental datasets for Nb3Sn, and the
anharmonic energy extracted from the fits is compared with first-principles
calculations.


title: Inifnite hypercomplex number system factorization methods

abstract:
  The method of obtaining the set of noncanonical hypercomplex number systems
by conversion of infinite hypercomplex number system to finite hypercomplex
number system depending on multiplication rules and factorization method is
described. Systems obtained by this method starting from the 3rddimension are
noncanonical. The obtained systems of even dimension can be re-factorized. As a
result of it hypercomplex number system of two times less dimension are got.


title:
A new class of exact solution of two-dimensional incompressible vortex
  motion

abstract:
  At present in the fluid mechanics, mostly one like to use the vortex as a
basic physical quantity, such that some exact solutions is based on the
vorticity evolution equation. For the vortex flow problem with axisymmetry, it
is well known that there exists in the circulation as a mechanical system of
basic physical quantities. In this paper, from the basic dynamic equation of
the mechanical system, the self-similar solution, eigenvalue system into a
self- consistent, new exact solutions of the two-dimensional circular symmetric
vortex flow are obtained, and some further comparison are made with the known
exact solutions. Key words: vortex motion, exact solution, eigenvalue system


title: Boundary-induced instabilities in coupled oscillators

abstract:
  A novel class of nonequilibrium phase-transitions at zero temperature is
found in chains of nonlinear oscillators.For two paradigmatic systems, the
Hamiltonian XY model and the discrete nonlinear Schr\"odinger equation, we find
that the application of boundary forces induces two synchronized phases,
separated by a non-trivial interfacial region where the kinetic temperature is
finite. Dynamics in such supercritical state displays anomalous chaotic
properties whereby some observables are non-extensive and transport is
superdiffusive. At finite temperatures, the transition is smoothed, but the
temperature profile is still non-monotonous.


title: On the relation between metallicity and RGB color in HST/ACS data

abstract:
  The determination of stellar metallicity and its gradient in external
galaxies is a difficult task, but crucial for the understanding of galaxy
formation and evolution. The color of the Red Giant Branch (RGB) can be used to
determine metallicities of stellar populations that have only shallow
photometry. We will quantify the relation between metallicity and color in the
widely used HST ACS filters F606W and F814W. We use a sample of globular
clusters from the ACS Globular Cluster Survey and measure their RGB color at
given absolute magnitudes to derive the color-metallicity relation. We
especially investigate the scatter and the uncertainties in this relation and
show its limitations. There is a clear relation between metallicity and RGB
color. A comparison with isochrones shows reasonably good agreement with BaSTI
models, a small offset to Dartmouth models, and a larger offset to Padua
models. Even for the best globular cluster data available, the metallicity of a
simple stellar population can be determined from the RGB alone only with an
accuracy of 0.3dex for [M/H]< -1, and 0.15dex for [M/H]> -1. For mixed
populations, as they are observed in external galaxies, the uncertainties will
be even larger due to uncertainties in extinction, age, etc. Therefore caution
is necessary when interpreting photometric metallicities.


title:
The accretion environment in Vela X-1 during a flaring period using
  XMM-Newton

abstract:
  We present analysis of 100 ks contiguous XMM-Newton data of the prototypical
wind accretor Vela X-1. The observation covered eclipse egress between orbital
phases 0.134 and 0.265, during which a giant flare took place, enabling us to
study the spectral properties both outside and during the flare. This giant
flare with a peak luminosity of $3.92^{+0.42}_{-0.09} \times 10^{37}$ erg
s$^{-1}$ allows estimates of the physical parameters of the accreted structure
with a mass of $\sim$ $10^{21}$ g.
  We have been able to model several contributions to the observed spectrum
with a phenomenological model formed by three absorbed power laws plus three
emission lines. After analysing the variations with orbital phase of the column
density of each component, as well as those in the Fe and Ni fluorescence
lines, we provide a physical interpretation for each spectral component.
Meanwhile, the first two components are two aspects of the principal accretion
component from the surface of the neutron star, and the third component seems
to be the \textit{X-ray light echo} formed in the stellar wind of the
companion.


title: Towards a theory of local Shimura varieties

abstract:
  This is a survey article that advertizes the idea that there should exist a
theory of p-adic local analogues of Shimura varieties. Prime examples are the
towers of rigid-analytic spaces defined by Rapoport-Zink spaces, and we also
review their theory in the light of this idea. We also discuss conjectures on
the $\ell$-adic cohomology of local Shimura varieties.


title: Smith ideals of structured ring spectra

abstract:
  Pursuing ideas of Jeff Smith, we develop a homotopy theory of ideals of
monoids in a symmetric monoidal model category. This includes Smith ideals of
structured ring spectra and of differential graded algebras. Such Smith ideals
are NOT subobjects, and as a result the theory seems to require us to consider
all Smith ideals of all monoids simultaneously, rather then restricting to the
Smith ideals of one particular monoid. However, we can take a quotient by a
Smith ideal and get a monoid homomorphism. In the stable case, we show that
this construction is part of a Quillen equivalence between a model category of
Smith ideals and a model category of monoid homomorphisms.


title:
Statistical Analysis based Hypothesis Testing Method in Biological
  Knowledge Discovery

abstract:
  The correlation and interactions among different biological entities comprise
the biological system. Although already revealed interactions contribute to the
understanding of different existing systems, researchers face many questions
everyday regarding inter-relationships among entities. Their queries have
potential role in exploring new relations which may open up a new area of
investigation. In this paper, we introduce a text mining based method for
answering the biological queries in terms of statistical computation such that
researchers can come up with new knowledge discovery. It facilitates user to
submit their query in natural linguistic form which can be treated as
hypothesis. Our proposed approach analyzes the hypothesis and measures the
p-value of the hypothesis with respect to the existing literature. Based on the
measured value, the system either accepts or rejects the hypothesis from
statistical point of view. Moreover, even it does not find any direct
relationship among the entities of the hypothesis, it presents a network to
give an integral overview of all the entities through which the entities might
be related. This is also congenial for the researchers to widen their view and
thus think of new hypothesis for further investigation. It assists researcher
to get a quantitative evaluation of their assumptions such that they can reach
a logical conclusion and thus aids in relevant re-searches of biological
knowledge discovery. The system also provides the researchers a graphical
interactive interface to submit their hypothesis for assessment in a more
convenient way.


title:
Quark scalar, axial, and pseudoscalar charges in the Schwinger-Dyson
  formalism

abstract:
  We calculate the scalar, axial, and pseudoscalar charges of the quark in the
Schwinger-Dyson formalism of Landau gauge QCD. It is found that the dressed
quark scalar density of the valence quark is significantly enhanced against the
bare quark contribution, and the result explains qualitatively the
phenomenologically known value of the pion-nucleon sigma term and also that
given by lattice QCD. Moreover, we show that the Richardson's interquark
potential suppresses the quark scalar density in the Higashjima-Miransky
approximation. This fact suggests that the quark scalar density is an
observable that is sensitive to quark confinement. For the quark axial charge,
we find that it is suppressed due to the gluon dynamics. The result of the
quenched analysis agrees qualitatively with the experimental data of the
isovector axial coupling constant $g_A$. We show that the suppression of the
quenched axial charge is due to a mechanism similar to that of the quark tensor
charge. In the Schwinger-Dyson equation with the leading unquenching quark-loop
contribution the quark axial charge is more suppressed, due to the anomaly
effect. The quark pseudoscalar density is found to be large, and is divergent
as the bare quark becomes massless. This result is in agreement with the
phenomenological current algebraic analysis, and explains well the dominance of
the pion-pole contribution.


title: Technical Report: Sleep-Route - Routing through Sleeping Sensors

abstract:
  In this article, we propose an energy-efficient data gathering scheme for
wireless sensor network called Sleep-Route, which splits the sensor nodes into
two sets - active and dormant (low-power sleep). Only the active set of sensor
nodes participate in data collection. The sensing values of the dormant sensor
nodes are predicted with the help of an active sensor node. Virtual Sensing
Framework (VSF) provides the mechanism to predict the sensing values by
exploiting the data correlation among the sensor nodes. If the number of active
sensor nodes can be minimized, a lot of energy can be saved. The active nodes'
selection must fulfill the following constraints - (i) the set of active nodes
are sufficient to predict the sensing values of the dormant nodes, (ii) each
active sensor nodes can report their data to the sink node (directly or through
some other active node(s)). The goal is to select a minimal number of active
sensor nodes so that energy savings can be maximized.
  The optimal set of active node selection raise a combinatorial optimization
problem, which we refer as Sleep-Route problem. We show that Sleep-Route
problem is NP-hard. Then, we formulate an integer linear program (ILP) to solve
the problem optimally. To solve the problem in polynomial time, we also propose
a heuristic algorithm that performs near optimally.


title:
A reduced semantics for deciding trace equivalence using constraint
  systems

abstract:
  Many privacy-type properties of security protocols can be modelled using
trace equivalence properties in suitable process algebras. It has been shown
that such properties can be decided for interesting classes of finite processes
(i.e., without replication) by means of symbolic execution and constraint
solving. However, this does not suffice to obtain practical tools. Current
prototypes suffer from a classical combinatorial explosion problem caused by
the exploration of many interleavings in the behaviour of processes.
M\"odersheim et al. have tackled this problem for reachability properties using
partial order reduction techniques. We revisit their work, generalize it and
adapt it for equivalence checking. We obtain an optimization in the form of a
reduced symbolic semantics that eliminates redundant interleavings on the fly.


title:
An energy-momentum map for the time-reversal symmetric 1:1 resonance
  with Z_2 X Z_2 symmetry

abstract:
  We present a general analysis of the bifurcation sequences of periodic orbits
in general position of a family of reversible 1:1 resonant Hamiltonian normal
forms invariant under $\Z_2\times\Z_2$ symmetry. The rich structure of these
classical systems is investigated both with a singularity theory approach and
geometric methods. The geometric approach readily allows to find an
energy-momentum map describing the phase space structure of each member of the
family and a catastrophe map that captures its global features. Quadrature
formulas for the actions, periods and rotation number are also provided.


title:
Jacob's ladders, heterogeneous quadrature formulae, big asymmetry and
  related formulae for the Riemann zeta-function

abstract:
  In this paper we obtain as our main result new class of formulae expressing
correlation integrals of the third-order in $Z$ on disconnected sets
$\mathring{G}_1(x),\mathring{G}_2(y)$ by means of an autocorrelative sum of the
second order in $Z$. Moreover, the distance of the sets
$\mathring{G}_1(x),\mathring{G}_2(y)$ from the set of arguments of
autocorrelative sum is extremely big, namely $\sim A\pi(T),\ T\to\infty$, where
$\pi(T)$ is the prime-counting function.


title: 2MASS wide field extinction maps: V. Corona Australis

abstract:
  We present a near-infrared extinction map of a large region ($\sim$870
deg$^2$) covering the isolated Corona Australis complex of molecular clouds. We
reach a 1-$\sigma$ error of 0.02 mag in the K-band extinction with a resolution
of 3 arcmin over the entire map. We find that the Corona Australis cloud is
about three times as large as revealed by previous CO and dust emission
surveys. The cloud consists of a 45 pc long complex of filamentary structure
from the well known star forming Western-end (the head, $N \geq10^{23}$
cm$^{-2}$) to the diffuse Eastern-end the tail, ($N \leq10^{21}$ cm$^{-2}$).
Remarkably, about two thirds of the complex both in size and mass lie beneath
A$_V\sim1$ mag. We find that the PDF of the cloud cannot be described by a
single log-normal function. Similar to prior studies, we found a significant
excess at high column densities, but a log-normal + power-law tail fit does not
work well at low column densities. We show that at low column densities near
the peak of the observed PDF, both the amplitude and shape of the PDF are
dominated by noise in the extinction measurements making it impractical to
derive the intrinsic cloud PDF below A$_K <$ 0.15 mag. Above A$_K \sim 0.15$
mag, essentially the molecular component of the cloud, the PDF appears to be
best described by a power-law with index $-3$, but could also described as the
tail of a broad and relatively low amplitude, log-normal PDF that peaks at very
low column densities.


title:
Mapping the radiative and the apparent non-radiative local density of
  states in the near field of a metallic nanoantenna

abstract:
  We present a novel method to extract the various contributions to the
photonic local density of states from near-field fluorescence maps. The
approach is based on the simultaneous mapping of the fluorescence intensity and
decay rate, and on the rigorous application of the reciprocity theorem. It
allows us to separate the contributions of the radiative and the apparent
non-radiative local density of states to the change in the decay rate. The
apparent non-radiative contribution accounts for losses due to radiation out of
the detection solid angle and to absorption in the environment. Data analysis
relies on a new analytical calculation, and does not require the use of
numerical simulations. One of the most relevant applications of the method is
the characterization of nanostructures aimed at maximizing the number of
photons emitted in the detection solid angle, which is a crucial issue in
modern nanophotonics.


title: On annealed elliptic Green function estimates

abstract:
  We consider a random, uniformly elliptic coefficient field $a$ on the lattice
$\mathbb{Z}^d$. The distribution $\langle \cdot \rangle$ of the coefficient
field is assumed to be stationary. Delmotte and Deuschel showed that the
gradient and second mixed derivative of the parabolic Green function $G(t,x,y)$
satisfy optimal annealed estimates which are $L^2$ resp. $L^1$ in probability,
i.e. they obtained bounds on $\langle |\nabla_x G(t,x,y)|^2
\rangle^{\frac{1}{2}}$ and $\langle |\nabla_x \nabla_y G(t,x,y)| \rangle$, see
T. Delmotte and J.-D. Deuschel: On estimating the derivatives of symmetric
diffusions in stationary random environments, with applications to the
$\nabla\phi$ interface model, Probab. Theory Relat. Fields 133 (2005),
358--390. In particular, the elliptic Green function $G(x,y)$ satisfies optimal
annealed bounds. In a recent work, the authors extended these elliptic bounds
to higher moments, i.e. $L^p$ in probability for all $p<\infty$, see D.
Marahrens and F. Otto: {Annealed estimates on the Green function},
arXiv:1304.4408 (2013). In this note, we present a new argument that relies
purely on elliptic theory to derive the elliptic estimates (see Proposition 1.2
below) for $\langle |\nabla_x G(x,y)|^2 \rangle^{\frac{1}{2}}$ and $\langle
|\nabla_x \nabla_y G(x,y)| \rangle$.


title: Complex temporal structure of activity in on-line electronic auctions

abstract:
  We analyze empirical data from the internet auction site Aukro.cz. The time
series of activity shows truncated fractal structure on scales from about 1
minute to about 1 day. The distribution of waiting times as well as the
distribution of number of auctions within fixed interval is a power law, with
exponents $1.5$ and $3$, respectively. Possible implications for the modeling
of stock-market fluctuations are briefly discussed.


title: Function spaces for second-order polynomial time

abstract:
  In the context of second-order polynomial-time computability, we prove that
there is no general function space construction. We proceed to identify
restrictions on the domain or the codomain that do provide a function space
with polynomial-time function evaluation containing all polynomial-time
computable functions of that type.
  As side results we show that a polynomial-time counterpart to admissibility
of a representation is not a suitable criterion for natural representations,
and that the Weihrauch degrees embed into the polynomial-time Weihrauch
degrees.


title:
Energy harvesting through gas dynamics in the free molecular flow regime
  between structured surfaces at different temperatures

abstract:
  For a gas confined between surfaces held at different temperatures the
velocity distribution shows a significant deviation from the Maxwell
distribution when the mean free path of the molecules is comparable to or
larger than the channel dimensions. If one of the surfaces is suitably
structured, this non-equilibrium distribution can be exploited for momentum
transfer in tangential direction between the two surfaces. This opens up the
possibility to extract work from the system which operates as a heat engine.
Since both surfaces are held at constant temperatures, the mode of momentum
transfer is different from thermal creep flow that has gained more attention so
far. This situation is studied in the limit of free-molecular flow for the case
that an unstructured surface is allowed to move tangentially with respect to a
structured surface. Parameter studies are conducted, and configurations with
maximum thermodynamic efficiency are identified. Overall, it is shown that
significant efficiencies can be obtained by tangential momentum transfer
between structured surfaces.


title: An explicit upper bound for the Helfgott delta in SL(2,p)

abstract:
  Helfgott proved that there exists a $\delta>0$ such that if $S$ is a
symmetric generating subset of $SL(2,p)$ containing 1 then either $S^3=SL(2,p)$
or $|S^3|\geq |S|^{1+\delta}$. It is known that $\delta\geq 1/3024$. Here we
show that $\delta\leq(\log_2(7)-1)/6 \approx 0.3012$ and we present evidence
suggesting that this might be the true value of $\delta$.


title: Quantum Theory in Design

abstract:
  In this paper, we use braiding diagrams to present rules of shapes and
designs. That is, we design colour, design size, design brightness, design
codes by means of braiding.


title:
Disentangling dynamical phase transitions from equilibrium phase
  transitions

abstract:
  Dynamical phase transitions (DPT) occur after quenching some global
parameters in quantum systems and are signalled by the non-analytical time
evolution of the dynamical free energy, which is calculated from the Loschmidt
overlap between the initial and time evolved states. In a recent letter (M.
Heyl et al., Phys. Rev. Lett. \textbf{110}, 135704 (2013)), it was suggested
that DPTs are closely related to equilibrium phase transitions (EPT) for the
transverse field Ising model. By studying a minimal model, the XY chain in
transverse magnetic field, we show analytically that this connection does not
hold generally. We present examples where DPT occurs without crossing any
equilibrium critical lines by the quench, and a nontrivial example with no DPT
but crossing a critical line by the quench. Albeit the non-analyticities of the
dynamical free energy on the real time axis do not indicate the presence or
absence of an EPT, the structure of Fisher-lines for complex times reveal a
qualitative difference.


title:
What is the effect of country-specific characteristics on the research
  performance of scientific institutions? Using multi-level statistical models
  to rank and map universities and research-focused institutions worldwide

abstract:
  Bornmann, Stefaner, de Moya Anegon, and Mutz (in press) have introduced a web
application (www.excellencemapping.net) which is linked to both academic
ranking lists published hitherto (e.g. the Academic Ranking of World
Universities) as well as spatial visualization approaches. The web application
visualizes institutional performance within specific subject areas as ranking
lists and on custom tile-based maps. The new, substantially enhanced version of
the web application and the multilevel logistic regression on which it is based
are described in this paper. Scopus data were used which have been collected
for the SCImago Institutions Ranking. Only those universities and
research-focused institutions are considered that have published at least 500
articles, reviews and conference papers in the period 2006 to 2010 in a certain
Scopus subject area. In the enhanced version, the effect of single covariates
(such as the per capita GDP of a country in which an institution is located) on
two performance metrics (best paper rate and best journal rate) is examined and
visualized. A covariate-adjusted ranking and mapping of the institutions is
produced in which the single covariates are held constant. The results on the
performance of institutions can then be interpreted as if the institutions all
had the same value (reference point) for the covariate in question. For
example, those institutions can be identified worldwide showing a very good
performance despite a bad financial situation in the corresponding country.


title: Bayesian analysis of redistribution policy with a fixed scale

abstract:
  A government has to finance a risk for its population. It shares the charges
among the population with a fixed scale based on economic criteria. Various
organisms have to collect and to redistribute fairly the subsidies. Under these
conditions, when the size of the organisms is varied, the distribution's laws
of the criteria are exponential families and criteria are semi linear
sufficient statistics.


title:
Pseudo Slice Energy Spread in Dynamics of Electron Beams Moving through
  Magnetic Bends

abstract:
  In the previous canonical formulation of beam dynamics for an electron bunch
moving ultrarelativistically through magnetic bending systems, we have shown
that the transverse dynamics equation for a particle in the bunch has a driving
term which behaves as the centrifugal force caused by the particle's initial
potential energy due to collective particle interactions within the bunch. As a
result, the initial potential energy at the entrance of a bending system, which
we call pseudo (kinetic) energy, is indistinguishable from the usual kinetic
energy offset from the design energy in its perturbation to particle optics
through dispersion and momentum compaction. In this paper, in identifying this
centrifugal force on particles as the remnant of the CSR cancellation effect in
transverse particle dynamics, we show how the dynamics equation in terms of the
canonical momentum for beam motion on a curved orbit is related to the
Panofsky-Wenzel theorem for wakefields for beam motion on a straight path. It
is shown that the effect of pseudo energy spread can be measurable only for a
high-peak-current bunch when the pseudo slice energy spread is appreciable
compared to the slice kinetic energy spread. The implication of the pseudo
slice energy spread for bunch dynamics in magnetic bends is discussed.


title: A basis of the group of primitive almost pythagorean triples

abstract:
  Let $m$ be a fixed square-free positive integer, then equivalence classes of
solutions of Diophantine equation $x^2+m\cdot y^2=z^2$ form an infinitely
generated abelian group under the operation induced by the complex
multiplication. A basis of this group is constructed here using prime ideals
and the ideal class group of the field $\mathbb Q (\sqrt{-m})$.


title: How to test the "quantumness" of a quantum computer?

abstract:
  We discuss whether, to what extent and how a quantum computing device can be
evaluated and simulated using classical tools.


title:
Tensor Representation and Manifold Learning Methods for Remote Sensing
  Images

abstract:
  One of the main purposes of earth observation is to extract interested
information and knowledge from remote sensing (RS) images with high efficiency
and accuracy. However, with the development of RS technologies, RS system
provide images with higher spatial and temporal resolution and more spectral
channels than before, and it is inefficient and almost impossible to manually
interpret these images. Thus, it is of great interests to explore automatic and
intelligent algorithms to quickly process such massive RS data with high
accuracy. This thesis targets to develop some efficient information extraction
algorithms for RS images, by relying on the advanced technologies in machine
learning. More precisely, we adopt the manifold learning algorithms as the
mainline and unify the regularization theory, tensor-based method, sparse
learning and transfer learning into the same framework. The main contributions
of this thesis are as follows.


title:
Hawking radiation - quasi-normal modes correspondence and effective
  states for nonextremal Reissner-Nordstr\"{o}m black holes

abstract:
  It is known that the nonstrictly thermal character of the Hawking radiation
spectrum harmonizes Hawking radiation with black hole (BH) quasi-normal modes
(QNM). This paramount issue has been recently analyzed in the framework of both
Schwarzschild BHs (SBH) and Kerr BHs (KBH). In this assignment, we generalize
the analysis to the framework of nonextremal Reissner-Nordstr\"{o}m BHs (RNBH).
Such a generalization is important because in both SBHs and KBHs an absorbed
(or emitted) particle has only mass. Instead, in RNBHs the particle has charge
as well as mass. In doing so, we expose that for the RNBH, QNMs can be
naturally interpreted in terms of quantum levels for both particle emission and
absorption. Conjointly, we generalize some concepts concerning the RNBH's
"effective states".


title: Differential geometry and scalar gravitational waves

abstract:
  Following some strong argumentations of differential geometry in the Landau's
book, some corrections about errors in the old literature on scalar
gravitational waves (SGWs) are given and discussed. In the analysis of the
response ofi nterferometers the computation is first performed in the low
frequencies approximation, then the analysis is applied to all SGWs in the full
frequency and angular dependences. The presented results are in agreement with
the more recent literature on SGWs.


title: Constant Factor Approximation for Capacitated k-Center with Outliers

abstract:
  The $k$-center problem is a classic facility location problem, where given an
edge-weighted graph $G = (V,E)$ one is to find a subset of $k$ vertices $S$,
such that each vertex in $V$ is "close" to some vertex in $S$. The
approximation status of this basic problem is well understood, as a simple
2-approximation algorithm is known to be tight. Consequently different
extensions were studied.
  In the capacitated version of the problem each vertex is assigned a capacity,
which is a strict upper bound on the number of clients a facility can serve,
when located at this vertex. A constant factor approximation for the
capacitated $k$-center was obtained last year by Cygan, Hajiaghayi and Khuller
[FOCS'12], which was recently improved to a 9-approximation by An, Bhaskara and
Svensson [arXiv'13].
  In a different generalization of the problem some clients (denoted as
outliers) may be disregarded. Here we are additionally given an integer $p$ and
the goal is to serve exactly $p$ clients, which the algorithm is free to
choose. In 2001 Charikar et al. [SODA'01] presented a 3-approximation for the
$k$-center problem with outliers.
  In this paper we consider a common generalization of the two extensions
previously studied separately, i.e. we work with the capacitated $k$-center
with outliers. We present the first constant factor approximation algorithm
with approximation ratio of 25 even for the case of non-uniform hard
capacities.


title: Epoch-dependent absorption line profile variability in lambda Cep

abstract:
  We present the analysis of a multi-epoch spectroscopic monitoring campaign of
the O6Ief star lambda Cep. Previous observations reported the existence of two
modes of non-radial pulsations in this star. Our data reveal a much more
complex situation. The frequency content of the power spectrum considerably
changes from one epoch to the other. We find no stable frequency that can
unambiguously be attributed to pulsations. The epoch-dependence of the
frequencies and variability patterns are similar to what is seen in the wind
emission lines of this and other Oef stars, suggesting that both phenomena
likely have the same, currently still unknown, origin.


title:
Discovery of Carbon Radio Recombination Lines in absorption towards
  Cygnus~A

abstract:
  We present the first detection of carbon radio recombination line absorption
along the line of sight to Cygnus A. The observations were carried out with the
LOw Frequency ARray in the 33 to 57 MHz range. These low frequency radio
observations provide us with a new line of sight to study the diffuse, neutral
gas in our Galaxy. To our knowledge this is the first time that foreground
Milky Way recombination line absorption has been observed against a bright
extragalactic background source.
  By stacking 48 carbon $\alpha$ lines in the observed frequency range we
detect carbon absorption with a signal-to-noise ratio of about 5. The average
carbon absorption has a peak optical depth of 2$\times$10$^{-4}$, a line width
of 10 km s$^{-1}$ and a velocity of +4 km s$^{-1}$ with respect to the local
standard of rest. The associated gas is found to have an electron temperature
$T_{e}\sim$ 110 K and density $n_{e}\sim$ 0.06 cm$^{-3}$. These properties
imply that the observed carbon $\alpha$ absorption likely arises in the cold
neutral medium of the Orion arm of the Milky Way. Hydrogen and helium lines
were not detected to a 3$\sigma$ peak optical depth limit of
1.5$\times$10$^{-4}$ for a 4 km s$^{-1}$ channel width.
  Radio recombination lines associated with Cygnus A itself were also searched
for, but are not detected. We set a 3$\sigma$ upper limit of
1.5$\times$10$^{-4}$ for the peak optical depth of these lines for a 4 km
s$^{-1}$ channel width.


title: A Gaudin-like determinant for overlaps of N\'eel and XXZ Bethe states

abstract:
  We derive a determinant expression for overlaps of Bethe states of the XXZ
spin chain with the N{\'e}el state, the ground state of the system in the
antiferromagnetic Ising limit. Our formula, of determinant form, is valid for
generic system size. Interestingly, it is remarkably similar to the well-known
Gaudin formula for the norm of Bethe states, and to another recently-derived
overlap formula appearing in the Lieb-Liniger model.


title: Time delays for attosecond streaking in photoionization of neon

abstract:
  We revisit the time-resolved photoemission in neon atoms as probed by
attosecond streaking. We calculate streaking time shifts for the emission of 2p
and 2s electrons and compare the relative delay as measured in a recent
experiment by Schultze et al. [Science 328, 1658 (2010)]. The B-spline R-matrix
method is employed to calculate accurate Eisenbud-Wigner-Smith time delays from
multi- electron dipole transition matrix elements for photoionization. The
additional laser field-induced time shifts in the exit channel are obtained
from separate, time-dependent simulations of a full streaking process by
solving the time-dependent Schr\"odinger equation on the single-active-electron
level. The resulting accurate total relative streaking time shifts between 2s
and 2p emission lie well below the experimental data. We identify the presence
of unresolved shake-up satellites in the experiment as a potential source of
error in the determination of streaking time shifts.


title: Modified Einstein and Finsler Like Theories on Tangent Lorentz Bundles

abstract:
  We study modifications of general relativity, GR, with nonlinear dispersion
relations which can be geometrized on tangent Lorentz bundles. Such modified
gravity theories, MGTs, can be modeled by gravitational Lagrange density
functionals $f(\mathbf{R},\mathbf{T},F)$ with generalized/ modified scalar
curvature $\mathbf{R}$, trace of matter field tensors $\mathbf{T}$ and modified
Finsler like generating function $F$. In particular, there are defined
extensions of GR with extra dimensional "velocity/ momentum" coordinates. For
four dimensional models, we prove that it is possible to decouple and integrate
in very general forms the gravitational fields for
$f(\mathbf{R},\mathbf{T},F)$-modified gravity using nonholonomic 2+2 splitting
and nonholonomic Finsler like variables $F$. We study the modified motion and
Newtonian limits of massive test particles on nonlinear geodesics approximated
with effective extra forces orthogonal to the four--velocity. We compute the
constraints on the magnitude of extra-accelerations and analyze perihelion
effects and possible cosmological implications of such theories. We also derive
the extended Raychaudhuri equation in the framework of a tangent Lorentz
bundle. Finally, we speculate on effective modelling of modified theories by
generic off-diagonal configurations in Einstein and/or MGTs and Finsler
gravity. We provide some examples for modified stationary (black) ellipsoid
configurations and locally anisotropic solitonic backgrounds.


title:
Impact of contrarians and intransigents in a kinetic model of opinion
  dynamics

abstract:
  In this work we study opinion formation on a fully-connected population
participating of a public debate with two distinct choices, where the agents
may adopt three different attitudes (favorable to either one choice or to the
other, or undecided). The interactions between agents occur by pairs and are
competitive, with couplings that are either negative with probability $p$ or
positive with probability $1-p$. This bimodal probability distribution of
couplings produces a behavior similar to the one resulting from the
introduction of Galam's contrarians in the population. In addition, we consider
that a fraction $d$ of the individuals are intransigent, that is, reluctant to
change their opinions. The consequences of the presence of contrarians and
intransigents are studied by means of computer simulations. Our results suggest
that the presence of inflexible agents affects the critical behavior of the
system, causing either the shift of the critical point or the suppression of
the ordering phase transition, depending on the groups of opinions
intransigents belong to. We also discuss the relevance of the model for real
social systems.


title: Bimodality as a signal of the nuclear liquid-gas phase transition

abstract:
  Here we present an explicit counterexample to a bimodality concept as the
unique signal of first order phase transition. Using an exact solution of the
simplified version of the statistical multifragmentation model we demonstrate
that the bimodal distributions can naturally appear in infinite system without
a phase transition in the regions of the negative values of the surface tension
coefficient. Also we propose a new parameterization for the compressible
nuclear liquid which is consistent with the L. van Hove axioms of statistical
mechanics. As a result the proposed model does not lead to the irregular
behaviour of the isotherms in the mixed phase region which is typical for
mean-field models. Peculiarly, the suggested approach to account for the
nuclear liquid compressibility automatically leads to an appearance of an
additional state that in many respects resembles the physical antinuclear
matter.


title:
Ghost-Free Massive $f(R)$ Theories Modelled as Effective Einstein Spaces
  and Cosmic Acceleration

abstract:
  We study how massive ghost-free gravity $f(R)$-modified theories, MGFTs, can
be encoded into generic off-diagonal Einstein spaces. Using "auxiliary"
connections completely defined by the metric fields and adapted to nonholonomic
frames with associated nonlinear connection structure, we decouple and
integrate in certain general forms the field equations in MGFT. Imposing
additional nonholonomic constraints, we can generate Levi-Civita, LC,
configurations and mimic MGFT effects via off-diagonal interactions of
effective Einstein and/or Einstein-Cartan gravity with nonholonomically induced
torsion. We show that imposing nonholonomic constraints it is possible
reproduce very specific models of massive $f(R)$ gravity studied in
\cite{sarid,odintsr}. The cosmological evolution of ghost-free off-diagonal
Einstein spaces is investigated. Certain compatibility of MGFT cosmology to
small off--diagonal deformations of $\Lambda $CDM models is established.


title: Higher-Dimensional Communication and S.E.T.I

abstract:
  In cosmologies with more than four dimensions, of the type required for
unification, it is possible for signals to have velocities in excess of that of
light. Using a five-dimensional model which otherwise agrees with observations,
two subjects are reviewed: (a) An exact solution of the field equations which
describes a 4D spacetime with a large cosmological constant and waves
travelling in ordinary 3D space with velocities exceeding lightspeed. (b) An
example where the 4D interval or proper time is modulated by the systematic
variation of the scalar field associated with the fifth dimension, providing a
simple signalling method. These and related consequences of higher-dimensional
cosmology have significant implications for astrophysics, and especially the
Search for Extraterrestrial Intelligence.


title:
Metal oxide resistive switching: evolution of the density of states
  across the metal-insulator transition

abstract:
  We report the study of metal-STO-metal memristors where the doping
concentration in STO can be fine-tuned through electric field migration of
oxygen vacancies. In this tunnel junction device, the evolution of the Density
Of States (DoS) can be followed continuously across the Metal-Insulator
Transition (MIT). At very low dopant concentration, the junction displays
characteristic signatures of discrete dopants levels. As the dopant
concentration increases, the semiconductor band gap fills in but a soft Coulomb
gap remains. At even higher doping, a transition to a metallic state occurs
where the DoS at the Fermi level becomes finite and Altshuler-Aronov
corrections to the DoS are observed. At the critical point of the MIT, the DoS
scales linearly with energy $N(\varepsilon) \sim \varepsilon$, the possible
signature of multifractality.


title:
Very Low-Density Planets around Kepler-51 Revealed with Transit Timing
  Variations and an Anomaly Similar to a Planet-Planet Eclipse Event

abstract:
  We present an analysis of the transit timing variations (TTVs) in the
multi-transiting planetary system around Kepler-51 (KOI-620). This system
consists of two confirmed transiting planets, Kepler-51b ($P_{\rm b} =
45.2\,\mathrm{days}$) and Kepler-51c ($P_{\rm c} = 85.3\,\mathrm{days}$), and
one transiting planet candidate KOI-620.02 ($P_{02} = 130.2\,\mathrm{days}$),
which lie close to a $1:2:3$ resonance chain. Our analysis shows that their
TTVs are consistently explained by the three-planet model, and constrains their
masses as $M_{\rm b} = 2.1_{-0.8}^{+1.5} M_{\oplus}$ (Kepler-51b), $M_{\rm c} =
4.0 \pm 0.4 M_{\oplus}$ (Kepler-51c), and $M_{02} = 7.6 \pm 1.1 M_{\oplus}$
(KOI-620.02), thus confirming KOI-620.02 as a planet in this system. The masses
inferred from the TTVs are rather small compared to the planetary radii based
on the stellar density and planet-to-star radius ratios determined from the
transit light curves. Combining these estimates, we find that all three planets
in this system have densities among the lowest determined, $\rho_p \lesssim
0.05\,{\rm g\,cm^{-3}}$. With this feature, the Kepler-51 system serves as
another example of low-density compact multi-transiting planetary systems. We
also identify a curious feature in the archived Kepler light curve during the
double transit of Kepler-51b and KOI-620.02, which could be explained by their
overlapping on the stellar disk (a planet-planet eclipse). If this is really
the case, the sky-plane inclination of KOI-620.02's orbit relative to that of
Kepler-51b is given by $\Delta \Omega = -25.3_{-6.8}^{+6.2}\mathrm{deg}$,
implying significant misalignment of their orbital planes. This interpretation,
however, seems unlikely because such an event that is consistent with all of
the observations is found to be exceedingly rare.


title: Thermodynamic Limits of Solar Cells with Non-ideal Optical Response

abstract:
  The Shockley-Queisser (S-Q) theory defines the thermodynamic upper limits for
Jsc, Voc, FF, and efficiency of a solar cell. The classical calculation assumes
an abrupt onset of absorption at the band-edge, perfect absorption for all
energies above the bandgap, and absence of non-radiative recombination. These
assumptions are never satisfied for any practical solar cell. In this paper, we
explain how the S-Q limits are redefined in the presence of the non-ideal
optical effects, and we provide closed-form analytical expressions for the new
limits for Jsc, Voc, and FF. Remarkably, these new limits can be achieved to a
very high degree, even with significantly imperfect materials.


title:
Heavily Irradiated N-in-p Thin Planar Pixel Sensors with and without
  Active Edges

abstract:
  We present the results of the characterization of silicon pixel modules
employing n-in-p planar sensors with an active thickness of 150
$\mathrm{\mu}$m, produced at MPP/HLL, and 100-200 $\mathrm{\mu}$m thin active
edge sensor devices, produced at VTT in Finland. These thin sensors are
designed as candidates for the ATLAS pixel detector upgrade to be operated at
the HL-LHC, as they ensure radiation hardness at high fluences. They are
interconnected to the ATLAS FE-I3 and FE-I4 read-out chips. Moreover, the
n-in-p technology only requires a single side processing and thereby it is a
cost-effective alternative to the n-in-n pixel technology presently employed in
the LHC experiments. High precision beam test measurements of the hit
efficiency have been performed on these devices both at the CERN SpS and at
DESY, Hamburg. We studied the behavior of these sensors at different bias
voltages and different beam incident angles up to the maximum one expected for
the new Insertable B-Layer of ATLAS and for HL-LHC detectors. Results obtained
with 150 $\mathrm{\mu}$m thin sensors, assembled with the new ATLAS FE-I4 chip
and irradiated up to a fluence of
4$\times$10$^{15}\mathrm{n}_{\mathrm{eq}}/\mathrm{cm}^2$, show that they are
excellent candidates for larger radii of the silicon pixel tracker in the
upgrade of the ATLAS detector at HL-LHC. In addition, the active edge
technology of the VTT devices maximizes the active area of the sensor and
reduces the material budget to suit the requirements for the innermost layers.
The edge pixel performance of VTT modules has been investigated at beam test
experiments and the analysis after irradiation up to a fluence of
5$\times$10$^{15}\mathrm{n}_{\mathrm{eq}}/\mathrm{cm}^2$ has been performed
using radioactive sources in the laboratory.


title:
Lessons from a Large-Scale Assessment: Results from Free Response Pre-
  and Post-testing in Electricity and Magnetism

abstract:
  As part of a large-scale assessment project at a large university, we
administered weekly pre-tests and bi-weekly post-tests in the recitation
sections of our introductory classes over four semesters from Spring 2010
through Fall 2011. The post-tests were administered as graded quizzes and were
developed to assess problem solving, laboratory, calculational and conceptual
skills that had been the focus of instruction in lab, lecture and recitation
sessions. They were not comprehensive, but gave us 'snapshots' of students'
abilities throughout the semester. They were used in conjunction with other
forms of assessment, such as conceptual inventories, to give us a broader
picture of the state of our undergraduate classes, recitation sections and
laboratories. The written pre- and post-tests, which required students to show
their work and explain their reasoning, yielded different information on
students' skills than the conceptual inventories. On almost all of the
questions, the students in the inquiry-based course performed better than all
of the other students in both the calculus-based and algebra-based classes.
This study indicates that the inquiry-based students perform better at
free-response questions that require students to show their work and explain
their reasoning, even though their conceptual inventory scores are not
significantly different from students in large lecture sections taught with
Physics Education Research-informed (PER-informed) laboratories, recitations
and lectures, as reported in a previous paper. This indicates a need for
different and/or more comprehensive assessment instruments to evaluate the
effectiveness of introductory materials and instructional techniques that can
be compared across classes and universities.


title: Unipotent representations as a categorical centre

abstract:
  Let G(F_q) be the group of rational points of a split connected reductive
group G defined over the finite field F_q. In this paper we show that the
category of representations of G(F_q) which are finite direct sums of unipotent
representations in a fixed two-sided cell is equivalent to the centre of a
certain monoidal category of sheaves on the product of two copies of the flag
manifold of G. We also consider a version of this for nonsplit groups.


title:
Hilbert transform along measurable vector fields constant on Lipschitz
  curves: $L^2$ boundedness

abstract:
  We prove the $L^2$ boundedness of the directional Hilbert transform in the
plane relative to measurable vector fields which are constant on suitable
Lipschitz curves.


title: Spherical Designs and Heights of Euclidean Lattices

abstract:
  We study the connection between the theory of spherical designs and the
question of extrema of the height function of lattices. More precisely, we show
that a full-rank n-dimensional Euclidean lattice, all layers of which hold a
spherical 2-design, realises a stationary point for the height function, which
is defined as the first derivative at 0 of the spectral zeta function of the
associated flat torus. Moreover, in order to find out the lattices for which
this 2-design property holds, a strategy is described which makes use of theta
functions with spherical coefficients, viewed as elements of some space of
modular forms. Explicit computations in dimension up to 7, performed with
Pari/GP and Magma, are reported.


title: Dispersive magnetic resonance mode in the Kondo semiconductor CeFe2Al10

abstract:
  The CeT2Al10 family of orthorhombic compounds exhibits a very peculiar
evolution from a Kondo-insulator (T: Fe) to an unconventional long-range
magnetic order (T: Ru, Os). Inelastic neutron scattering experiments performed
on single-crystal CeFe2Al10 reveal that this material develops a spin-gap in
its magnetic spectral response below ~ 50 K, with a magnetic excitation
dispersing from $E = 10.2 \pm 0.5$ meV at the Y zone-boundary point [q =
(0,1,0)] to $\approx 12$ meV at the top of the branch. The excitation shows a
pronounced polarization of the magnetic fluctuations along a, the easy
anisotropy axis. Its behavior is contrasted with that of the (magnonlike) modes
previously reported for CeRu2Al10, which have transverse character and exist
only in the antiferromagnetic state. The present observation is ascribed to a
"magnetic exciton" mechanism invoked to explain a similar magnetic response
previously discovered in YbB12.


title:
Recovery of bivariate band limited functions using scattered translates
  of the Poisson kernel

abstract:
  This paper continues the study of interpolation operators on scattered data.
We introduce the Poisson interpolation operator and prove various properties.
The main result concerns functions in the Paley-Wiener space $PW_{B_\beta}$,
and shows that one may recover these functions from their samples on a complete
interpolating sequence for $[-\delta,\delta]^2$ by using the Poisson
interpolation operator, provided that $0<\beta < (3-\sqrt{8})\delta$.


title: Exact Bayesian Inference for the Bingham Distribution

abstract:
  This paper is concerned with making Bayesian inference from data that are
assumed to be drawn from a Bingham distribution. A barrier to the Bayesian
approach is the parameter-dependent normalising constant of the Bingham
distribution, which, even when it can be evaluated or accurately approximated,
would have to be calculated at each iteration of an MCMC scheme, thereby
greatly increasing the computational burden. We propose a method which enables
exact (in Monte Carlo sense) Bayesian inference for the unknown parameters of
the Bingham distribution by completely avoiding the need to evaluate this
constant. We apply the method to simulated and real data, and illustrate that
it is simpler to implement, faster, and performs better than an alternative
algorithm that has recently been proposed in the literature.


title: Theoretical uncertainties of the type Ia supernova rate

abstract:
  It is thought that type Ia supernovae (SNe Ia) are explosions of
carbon-oxygen white dwarfs (CO WDs). Two main evolutionary channels are
proposed for the WD to reach the critical density required for a thermonuclear
explosion: the single degenerate scenario (SD), in which a CO WD accretes from
a non-degenerate companion, and the double degenerate scenario (DD), in which
two CO WDs merge. However, it remains difficult to reproduce the observed SN Ia
rate with these two scenarios.
  With a binary population synthesis code we study the main evolutionary
channels that lead to SNe Ia and we calculate the SN Ia rates and the
associated delay time distributions. We find that the DD channel is the
dominant formation channel for the longest delay times. The SD channel with
helium-rich donors is the dominant channel at the shortest delay times. Our
standard model rate is a factor five lower than the observed rate in galaxy
clusters.
  We investigate the influence of ill-constrained aspects of single- and
binary-star evolution and uncertain initial binary distributions on the rate of
type Ia SNe. These distributions, as well as uncertainties in both helium star
evolution and common envelope evolution, have the greatest influence on our
calculated rates. Inefficient common envelope evolution increases the relative
number of SD explosions such that for $\alpha_{\rm ce} = 0.2$ they dominate the
SN Ia rate. Our highest rate is a factor three less than the galaxy-cluster SN
Ia rate, but compatible with the rate determined in a field-galaxy dominated
sample. If we assume unlimited accretion onto WDs, to maximize the number of SD
explosions, our rate is compatible with the observed galaxy-cluster rate.


title:
A Bose-Einstein Condensate with $\mathcal{PT}$-Symmetric Double-Delta
  Function Loss and Gain in a Harmonic Trap: A Test of Rigorous Estimates

abstract:
  We consider the linear and nonlinear Schr\"odinger equation for a
Bose-Einstein condensate in a harmonic trap with $\cal {PT}$-symmetric
double-delta function loss and gain terms. We verify that the conditions for
the applicability of a recent proposition by Mityagin and Siegl on singular
perturbations of harmonic oscillator type self-adjoint operators are fulfilled.
In both the linear and nonlinear case we calculate numerically the shifts of
the unperturbed levels with quantum numbers $n$ of up to 89 in dependence on
the strength of the non-Hermiticity and compare with rigorous estimates derived
by those authors. We confirm that the predicted $1/n^{1/2}$ estimate provides a
valid upper bound on the the shrink rate of the numerical eigenvalues.
Moreover, we find that a more recent estimate of $\log(n)/n^{3/2}$ is in
excellent agreement with the numerical results. With nonlinearity the shrink
rates are found to be smaller than without nonlinearity, and the rigorous
estimates, derived only for the linear case, are no longer applicable.


title:
Violation of contextual generalization of the Leggett-Garg inequality
  for recognition of ambiguous figures

abstract:
  We interpret the Leggett-Garg (LG) inequality as a kind of contextual
probabilistic inequality in which one combines data collected in experiments
performed for three different contexts. In the original version of the
inequality these contexts have the temporal nature and they are given by three
pairs of instances of time, $(t_1, t_2), (t_2, t_3), (t_3, t_4),$ where $t_1 <
t_2 < t_3.$ We generalize LG conditions of macroscopic realism and noninvasive
measurability in the general contextual framework. Our formulation is done in
the purely probabilistic terms: existence of the context independent joint
probability distribution $P$ and the possibility to reconstruct the
experimentally found marginal (two dimensional) probability distributions from
the $P.$ We derive an analog of the LG inequality, "contextual LG inequality",
and use it as a test of "quantum-likeness" of statistical data collected in a
series of experiments on recognition of ambiguous figures. In our experimental
study the figure under recognition is the Schroeder stair which is shown with
rotations for different angles. Contexts are encoded by dynamics of rotations:
clockwise, anticlockwise, and random. Our data demonstrated violation of the
contextual LG inequality for some combinations of aforementioned contexts.
Since in quantum theory and experiments with quantum physical systems this
inequality is violated, e.g., in the form of the original LG-inequality, our
result can be interpreted as a sign that the quantum(-like) models can provide
a more adequate description of the data generated in the process of recognition
of ambiguous figures.

categories: q-bio.NC math.PR math.ST quant-ph stat.TH


title: Gravitomagnetic effects in conformal gravity

abstract:
  Gravitomagnetic effects are characterized by two phenomena: first, the
geodetic effect which describes the precession of the spin of a gyroscope in a
free orbit around a massive object, second, the Lense-Thirring effect which
describes the precession of the orbital plane about a rotating source mass. We
calculate both these effects in the fourth-order theory of conformal Weyl
gravity for the test case of circular orbits. We show that for the geodetic
effect a linear term arises which may be interesting for high radial orbits,
whereas for the Lense-Thirring effect the additional term has a diminishing
effect for most orbits. Circular orbits are also considered in general leading
up to a generalization of Kepler's third law.


title:
Application of the Modified Fractal Signature Method for Terrain
  Classification from Synthetic Aperture Radar Images

abstract:
  In this paper the Modified Fractal Signature method is applied to real
Synthetic Aperture Radar images provided to our research group by SET 163
Working Group on SAR radar techniques. This method uses the blanket technique
to provide useful information for SAR image classification. It is based on the
calculation of the volume of a blanket, corresponding to the image to be
classified, and then on the calculation of the corresponding Fractal Area curve
and Fractal Dimension curve of the image. The main idea concerning this
proposed technique is the fact that different terrain types encountered in SAR
images yield different values of Fractal Area curves and Fractal Dimension
curves, upon which classification of different types of terrain is possible. As
a result, a classification technique for five different terrain types, i.e.
urban, suburban, rural, mountain and sea, is presented in this paper.


title: Efficient tree methods for pricing digital barrier options

abstract:
  We propose an efficient lattice procedure which permits to obtain European
and American option prices under the Black and Scholes model for digital
options with barrier features. Numerical results show the accuracy of the
proposed method.


title:
A high resolution spectroscopic atlas of M subdwarfs - Effective
  temperature and metallicity

abstract:
  Context. M subdwarfs are metal poor and cool stars. They are important probes
of the old galactic populations. However, they remain elusive due to their low
luminosity. Observational and modeling efforts are required to fully understand
their physics and to investigate the effects of metallicity in their cool
atmospheres.
  Aims. We perform a detailed study of a sample of subdwarfs to determine their
stellar parameters and constrain the stat-of-the art atmospheric models.
  Methods. We present UVES/VLT high resolution spectra of three late-K
subdwarfs and 18 M subdwarfs. Our atlas covers the optical region from 6400 AA
up to the near infrared at 8900 AA. We show spectral details of cool
atmospheres at very high resolution (R= 40 000) and compare with synthetic
spectra computed from the recent BT-Settl atmosphere models.
  Results. Our comparison shows that molecular features (TiO, VO, CaH), and
atomic features (Fe I, Ti I, Na I, K I) are well fitted by current models. We
produce an effective temperature versus spectral type relation all over the
subdwarf spectral sequence. Thanks to the high resolution of our spectra, we
perform a detailed comparison of line profiles of individual elements such as
Fe I, Ca II, Ti I, and are able to determine accurate metallicities of these
stars. These determinations contribute to calibrate the relation between
metallicity and molecular band strength indices from low-resolution spectra.
  Conclusions. This work shows that the new generation of models are able to
reproduce various spectral features of M subdwarfs. Working with these high
resolution spectra allowed us to disentangle the atmospheric parameters
(effective temperature, gravity, metallicity), which is not possible when using
low resolution spectroscopy or photometry.


title:
An Alternate Approach for Designing a Domain Specific Image Search
  Prototype Using Histogram

abstract:
  Everyone knows that thousand of words are represented by a single image. As a
result image search has become a very popular mechanism for the Web searchers.
Image search means, the search results are produced by the search engine should
be a set of images along with their Web page Unified Resource Locator. Now Web
searcher can perform two types of image search, they are Text to Image and
Image to Image search. In Text to Image search, search query should be a text.
Based on the input text data system will generate a set of images along with
their Web page URL as an output. On the other hand, in Image to Image search,
search query should be an image and based on this image system will generate a
set of images along with their Web page URL as an output. According to the
current scenarios, Text to Image search mechanism always not returns perfect
result. It matches the text data and then displays the corresponding images as
an output, which is not always perfect. To resolve this problem, Web
researchers have introduced the Image to Image search mechanism. In this paper,
we have also proposed an alternate approach of Image to Image search mechanism
using Histogram.


title:
Group actions on pro-$C^{*}$-algebras and their pro-$C^{*}$-crossed
  products

abstract:
  In this paper, we define the notions of full pro-$C^{*}$-crossed product,
respectively reduced pro-$C^{*}$-crossed product, of a pro-$C^{*}$-algebra
$A[\tau_{\Gamma}] $ by a strong bounded action $\alpha$ of a locally compact
group $G$ and investigate some their properties.


title: A remarkable recurrent nova in M31 - The X-ray observations

abstract:
  Another outburst of the recurrent M31 nova M31N 2008-12a was announced in
late November 2013. Optical data suggest an unprecedentedly short recurrence
time of approximately one year. In this Letter we address the X-ray properties
of M31N 2008-12a. We requested Swift monitoring observations shortly after the
optical discovery. We estimated source count rates and extracted X-ray spectra
from the resulting data. The corresponding ultraviolet (UV) data was also
analysed. M31N 2008-12a was clearly detected as a bright supersoft X-ray source
(SSS) only six days after the well-constrained optical discovery. It displayed
a short SSS phase of two weeks duration and an exceptionally hot X-ray spectrum
with an effective blackbody temperature of ~97 eV. During the SSS phase the
X-ray light curve displayed significant variability that might have been
accompanied by spectral variations. The very early X-ray variability was found
to be anti-correlated with simultaneous variations in the UV flux. The X-ray
properties of M31N 2008-12a coherently point towards a high-mass white dwarf in
the nova system. This object might be a promising Type Ia supernova progenitor.
We re-discovered additional X-ray detections of M31N 2008-12a that are
consistent with our data and increase the number of known nova outbursts to
seven. This nova is an exceptional object that merits further attention in the
future.


title: A remarkable recurrent nova in M31 - The optical observations

abstract:
  Context: In late November 2013 a fifth eruption in five years of the M31
recurrent nova M31N 2008-12a was announced.
  Aims: In this Letter we address the optical lightcurve and progenitor system
of M31N 2008-12a.
  Methods: Optical imaging data of the 2013 eruption from the Liverpool
Telescope, La Palma, and Danish 1.54m Telescope, La Silla, and archival Hubble
Space Telescope near-IR, optical and near-UV data are astrometrically and
photometrically analysed.
  Results: Photometry of the 2013 eruption, combined with three previous
eruptions, enabled construction of a template light curve of a very fast nova,
t2(V)~4 days. The archival data allowed recovery of the progenitor system in
optical and near-UV data, indicating a red-giant secondary with bright
accretion disk, or alternatively a system with a sub-giant secondary but
dominated by a disk.
  Conclusions: The eruptions of M31N 2008-12a, and a number of historic X-ray
detections, indicate a unique system with a recurrence timescale of ~1 year.
This implies the presence of a very high mass white dwarf and a high accretion
rate. The recovered progenitor system is consistent with such an elevated rate
of accretion.We encourage additional observations, especially towards the end
of 2014.


title:
An $L^p$ theory of sparse graph convergence I: limits, sparse random
  graph models, and power law distributions

abstract:
  We introduce and develop a theory of limits for sequences of sparse graphs
based on $L^p$ graphons, which generalizes both the existing $L^\infty$ theory
of dense graph limits and its extension by Bollob\'as and Riordan to sparse
graphs without dense spots. In doing so, we replace the no dense spots
hypothesis with weaker assumptions, which allow us to analyze graphs with power
law degree distributions. This gives the first broadly applicable limit theory
for sparse graphs with unbounded average degrees. In this paper, we lay the
foundations of the $L^p$ theory of graphons, characterize convergence, and
develop corresponding random graph models, while we prove the equivalence of
several alternative metrics in a companion paper.


title:
A New Fast Numerical Method for One-Dimensional Nonlinear Sine-Gordon
  Equation Using Multivariate Pad\'e approximation

abstract:
  This paper has two purposes. First we present a new definition of the
multivariate Pad\'e approximation, a new fast numerical method. Then numerical
solution of the one-dimensional (1D) time-dependent nonlinear Sine-Gordon
equation (SGE) is considered by this method. Numerical results are obtained for
various cases involving undamped SGE. The results of numerical experiments are
presented and are compared with analytical solutions to confirm the good
accuracy of the presented scheme. It is shown that the technique is easy to
apply for multidimensional problems.


title: $(n D+1)$ Pad\'e approximation

abstract:
  To generalize the concept of Pad\'e approximation for functions to more than
one variable, several definitions have been introduced. All definitions have
advantages and disadvantages. The advantages of these approaches has been
discussed in many articles. One of the main disadvantages of these methods are
low convergence rate and the loss of information in computing with low degrees.
In this work we present a new definition of the multivariate Pad\'e
approximation, treated the more than one variable to the coefficients. Our
definition is designed to avoid such disadvantages with retaining the
advantages of simple and easily computation. The main result obtained as
consequence of this definition is some properties and convergence results of
the Montessus De Ballore theorem.


title: Coherent Electronic Coupling in Atomically Thin MoSe2

abstract:
  We report the first direct spectroscopic evidence for coherent electronic
coupling between excitons and trions in atomically thin transition metal
dichalcogenides, specifically monolayer MoSe2. Signatures of coupling appear as
isolated cross-peaks in two-color pump-probe spectra, and the lineshape of the
peaks reveals that the coupling originates from many-body interactions.
Excellent agreement between the experiment and density matrix calculations
suggests the formation of a correlated exciton-trion state due to their
coupling.


title: Defining and detecting quantum speedup

abstract:
  The development of small-scale digital and analog quantum devices raises the
question of how to fairly assess and compare the computational power of
classical and quantum devices, and of how to detect quantum speedup. Here we
show how to define and measure quantum speedup in various scenarios, and how to
avoid pitfalls that might mask or fake quantum speedup. We illustrate our
discussion with data from a randomized benchmark test on a D-Wave Two device
with up to 503 qubits. Comparing the performance of the device on random spin
glass instances with limited precision to simulated classical and quantum
annealers, we find no evidence of quantum speedup when the entire data set is
considered, and obtain inconclusive results when comparing subsets of instances
on an instance-by-instance basis. Our results for one particular benchmark do
not rule out the possibility of speedup for other classes of problems and
illustrate that quantum speedup is elusive and can depend on the question
posed.


title:
Front End Data Cleaning And Transformation In Standard Printed Form
  Using Neural Models

abstract:
  Front end of data collection and loading into database manually may cause
potential errors in data sets and a very time consuming process. Scanning of a
data document in the form of an image and recognition of corresponding
information in that image can be considered as a possible solution of this
challenge. This paper presents an automated solution for the problem of data
cleansing and recognition of user written data to transform into standard
printed format with the help of artificial neural networks. Three different
neural models namely direct, correlation based and hierarchical have been
developed to handle this issue. In a very hostile input environment, the
solution is developed to justify the proposed logic.


title: A tight lower bound instance for k-means++ in constant dimension

abstract:
  The k-means++ seeding algorithm is one of the most popular algorithms that is
used for finding the initial $k$ centers when using the k-means heuristic. The
algorithm is a simple sampling procedure and can be described as follows: Pick
the first center randomly from the given points. For $i > 1$, pick a point to
be the $i^{th}$ center with probability proportional to the square of the
Euclidean distance of this point to the closest previously $(i-1)$ chosen
centers.
  The k-means++ seeding algorithm is not only simple and fast but also gives an
$O(\log{k})$ approximation in expectation as shown by Arthur and Vassilvitskii.
There are datasets on which this seeding algorithm gives an approximation
factor of $\Omega(\log{k})$ in expectation. However, it is not clear from these
results if the algorithm achieves good approximation factor with reasonably
high probability (say $1/poly(k)$). Brunsch and R\"{o}glin gave a dataset where
the k-means++ seeding algorithm achieves an $O(\log{k})$ approximation ratio
with probability that is exponentially small in $k$. However, this and all
other known lower-bound examples are high dimensional. So, an open problem was
to understand the behavior of the algorithm on low dimensional datasets. In
this work, we give a simple two dimensional dataset on which the seeding
algorithm achieves an $O(\log{k})$ approximation ratio with probability
exponentially small in $k$. This solves open problems posed by Mahajan et al.
and by Brunsch and R\"{o}glin.


title: Charged Exotic Charmonium States

abstract:
  In this short review we present and discuss all the experimental information
about the charged exotic charmonium states, which have been observed over the
last five years. We try to understand their properties such as masses and decay
widths with QCD sum rules. We describe this method, show the results and
compare them with the experimental data and with other theoretical approaches.


title:
Rheology of dense suspensions of elastic capsules: normal stresses,
  yield stress, jamming and confinement effects

abstract:
  We study the shearing rheology of dense suspensions of elastic capsules,
taking aggregation-free red blood cells as a physiologically relevant example.
Particles are non-Brownian and interact only via hydrodynamics and short-range
repulsive forces. An analysis of the different stress mechanisms in the
suspension shows that the viscosity is governed by the shear elasticity of the
capsules, whereas the repulsive forces are subdominant. Evidence for a dynamic
yield stress above a critical volume fraction is provided and related to the
elastic properties of the capsules. The shear stress is found to follow a
critical jamming scenario and is rather insensitive to the
tumbling-to-tank-treading transition. The particle pressure and normal stress
differences display some sensitivity to the dynamical state of the cells and
exhibit a characteristic scaling, following the behavior of a single particle,
in the tank-treading regime. The behavior of the viscosity in the fluid phase
is rationalized in terms of effective medium models. Furthermore, the role of
confinement effects, which increase the overall magnitude and enhance the
shear-thinning of the viscosity, is discussed.


title:
Search for Extended {\gamma}-ray Emission around AGN with H.E.S.S. and
  Fermi-LAT

abstract:
  Context: Very-high-energy (VHE; E>100 GeV) {\gamma}-ray emission from blazars
inevitably gives rise to electron-positron pair production through the
interaction of these {\gamma}-rays with the Extragalactic Background Light
(EBL). Depending on the magnetic fields in the proximity of the source, the
cascade initiated from pair production can result in either an isotropic halo
around an initially beamed source or a magnetically broadened cascade flux.
Aims: Both extended pair halo (PH) and magnetically broadened cascade (MBC)
emission from regions surrounding the blazars 1ES 1101-232, 1ES 0229+200 and
PKS 2155-304 were searched for, using VHE {\gamma}-ray data taken with the High
Energy Stereoscopic System (H.E.S.S.), and high energy (HE; 100 MeV<E<100 GeV)
{\gamma}-ray data with the Fermi Large Area Telescope (LAT). Methods: By
comparing the angular distributions of the reconstructed gamma-ray events to
the angular profiles calculated from detailed theoretical models, the presence
of PH and MBC was investigated. Results: Upper limits on the extended emission
around 1ES 1101-232, 1ES 0229+200 and PKS 2155-304 are found to be at a level
of few percent of the Crab nebula flux above 1 TeV, depending on the assumed
photon index of the cascade emission. Assuming strong Extra-Galactic Magnetic
Field (EGMF) values, > 10$^{-12}$G, this limits the production of pair halos
developing from electromagnetic cascades. For weaker magnetic fields, in which
electromagnetic cascades would result in magnetically broadened cascades, EGMF
strengths in the range (0.3 - 3)$\times 10^{-15}$G were excluded for PKS
2155-304 at the 99% confidence level, under the assumption of a 1 Mpc coherence
length.


title: Big Bang nucleosynthesis in visible and hidden-mirror sectors

abstract:
  One of the still viable candidates for the dark matter is the so-called
mirror matter. Its cosmological and astrophysical implications were widely
studied in many aspects, pointing out the importance to go further with
research and refine the studies. In particular, the Big Bang nucleosynthesis
provides a strong test for every dark matter candidate, since it is well
studied and involves relatively few free parameters. The necessity of accurate
studies of primordial nucleosynthesis with mirror matter has then emerged. In
order to fill this lack, I present here the results of accurate numerical
simulations of the primordial production of both ordinary nuclides and nuclides
made of mirror baryons, in presence of a hidden mirror sector with unbroken
parity symmetry and with gravitational interactions only. These elements are
the building blocks of all the structures forming in the Universe, therefore
their chemical composition is a key ingredient for astrophysics with mirror
dark matter. The production of ordinary nuclides show differences from the
standard model for a ratio of the temperatures between mirror and ordinary
sectors x = T'/T > 0.3, and they present an interesting decrease of the
abundance of 7Li. For the mirror nuclides, instead, one observes an enhanced
production of 4He, that becomes the dominant element for x < 0.5, and much
larger abundances of heavier elements.


title: Diffusion processes satisfying a conservation law constraint

abstract:
  We investigate coupled stochastic differential equations governing N
non-negative continuous random variables that satisfy a conservation principle.
In various fields a conservation law requires that a set of fluctuating
variables be non-negative and (if appropriately normalized) sum to one. As a
result, any stochastic differential equation model to be realizable must not
produce events outside of the allowed sample space. We develop a set of
constraints on the drift and diffusion terms of such stochastic models to
ensure that both the non-negativity and the unit-sum conservation law
constraint are satisfied as the variables evolve in time. We investigate the
consequences of the developed constraints on the Fokker-Planck equation, the
associated system of stochastic differential equations, and the evolution
equations of the first four moments of the probability density function. We
show that random variables, satisfying a conservation law constraint,
represented by stochastic diffusion processes, must have diffusion terms that
are coupled and nonlinear. The set of constraints developed enables the
development of statistical representations of fluctuating variables satisfying
a conservation law. We exemplify the results with the bivariate beta process
and the multivariate Wright-Fisher, Dirichlet, and Lochner's generalized
Dirichlet processes.

categories: math.PR math-ph math.MP nlin.CD physics.flu-dyn


title: Constructing projective varieties in weighted flag varieties II

abstract:
  We give the construction of weighted Lagranngiann Grassmannians$wLGr(3,6)$
and weighted partial $A_3$ flag variety $wFl_{1,3}$ coming from the symplectic
Lie group $Sp(6,\mathbb C)$ and the general linear group $GL(4,\mathbb C)$
respectively. We give general formulas for their Hilbert series in terms of Lie
theoretic data. We use them as key varieties (Format) to construct some
families of polarized 3-folds in codimension 7 and 9. At the end, we list all
the distinct weighted flag varieties in codimension $4\le c\le 10$.


title: A simple Hubble-like law in lieu of dark energy

abstract:
  Within the frame of the $\Lambda$ cold dark matter paradigm, a dark energy
component of unknown origin is expected to represent nearly 70% of the energy
of the Universe. Herein, a non-standard form of the Hubble law is advocated,
with the aim of providing safe grounds on which alternative cosmologies could
be developed. Noteworthy, it yields an age-redshift relationship which is
consistent with available data. Together with a straightforward analysis of
gamma-ray burst counts, it further suggests that the observable Universe has
been euclidean and static over the last 12 Gyr. Although a non-standard
distance-duality relation is then required for interpreting luminosity
distances, the magnitude-redshift relationship obtained is compatible with type
Ia supernovae data.


title:
The EFTOS Voting Farm: A Software Tool for Fault Masking in Message
  Passing Parallel Environments

abstract:
  We present a set of C functions implementing a distributed software voting
mechanism for EPX or similar message passing environments, and we place it
within the EFTOS framework (Embedded Fault-Tolerant Supercomputing, ESPRIT-IV
Project 21012) of software tools for enhancing the dependability of a user
application. The described mechanism can be used for instance to implement
restoring organs i.e., N-modular redundancy systems with N-replicated voters.
We show that, besides structural design goals like fault transparency, this
tool achieves replication transparency, a high degree of flexibility and
ease-of-use, and good performance.


title: Information Entropy Dynamics and Maximum Entropy Production Principle

abstract:
  The asymptotic convergence of probability density function (pdf) and
convergence of differential entropy are examined for the non-stationary
processes that follow the maximum entropy principle (MaxEnt) and maximum
entropy production principle (MEPP). Asymptotic convergence of pdf provides new
justification of MEPP while convergence of differential entropy is important in
asymptotic analysis of communication systems. A set of equations describing the
dynamics of pdf under mass conservation and energy conservation constraints is
derived. It is shown that for pdfs with compact carrier the limit pdf is unique
and can be obtained from Jaynes's MaxEnt principle.


title: Initiation of Coronal Mass Ejections by Sunspot Rotation

abstract:
  We study a filament eruption, two-ribbon flare, and coronal mass ejection
(CME) that occurred in Active Region NOAA 10898 on 6 July 2006. The filament
was located South of a strong sunspot that dominated the region. In the
evolution leading up to the eruption, and for some time after it, a
counter-clockwise rotation of the sunspot of about 30 degrees was observed. We
suggest that the rotation triggered the eruption by progressively expanding the
magnetic field above the filament. To test this scenario, we study the effect
of twisting the initially potential field overlying a pre-existing flux-rope,
using three-dimensional zero-$\beta$ MHD simulations. We first consider a
relatively simple and symmetric system, and then study a more complex and
asymmetric magnetic configuration, whose photospheric flux distribution and
coronal structure are guided by the observations and a potential field
extrapolation. In both cases, we find that the twisting leads to the expansion
of the overlying field. As a consequence of the progressively reduced magnetic
tension, the flux-rope quasi-statically adapts to the changed environmental
field, rising slowly. Once the tension is sufficiently reduced, a distinct
second phase of evolution occurs where the flux-rope enters an unstable regime
characterized by a strong acceleration. Our simulations thus suggest a new
mechanism for the triggering of eruptions in the vicinity of rotating sunspots.


title: Kolmogorov problem on the class of multiply monotone functions

abstract:
  Necessary and sufficient conditions for positive numbers $M_{k_1}, M_{k_2},
M_{k_3}, M_{k_4}$, $0 = k_1 < k_2<k_2\leq r-2$, $k_4=r$, to guarantee the
existence of an $r-1$-monotone function defined on the negative half-line and
such that $\|x^{(k_i)}\| = M_{k_i}$, $i=1,2,3,4$ were found.


title: Time-Dependent Photon Statistics in Variable Media

abstract:
  We find explicit solutions of the Heisenberg equations of motion for a
quadratic Hamiltonian, describing a generic model of variable media, in the
case of multi-parameter squeezed input photon configuration. The corresponding
probability amplitudes and photon statistics are also derived in the
Schroedinger picture in an abstract operator setting of the quantum
electrodynamics (QED). Their time evolution is given in terms of solutions of
certain Ermakov-type system. The unitary transformation and an extension of the
squeeze/evolution operator are introduced formally.


title:
Meridional circulation of gas into gaps opened by giant planets in
  three-dimensional low-viscosity disks

abstract:
  We examine the gas circulation near a gap opened by a giant planet in a
protoplanetary disk. We show with high resolution 3D simulations that the gas
flows into the gap at high altitude over the mid-plane, at a rate dependent on
viscosity. We explain this observation with a simple conceptual model. From
this model we derive an estimate of the amount of gas flowing into a gap opened
by a planet with Hill radius comparable to the scale-height of a layered disk
(i. e. a disk with viscous upper layer and inviscid midplane). Our estimate
agrees with modern MRI simulations(Gressel et al., 2013). We conclude that gap
opening in a layered disk can not slow down significantly the runaway gas
accretion of Saturn to Jupiter-mass planets.


title: Horizon-Flow off-track for Inflation

abstract:
  Inflation can be parameterized by means of truncated flow equations. In this
"horizon-flow" setup, generic results have been obtained, such as typical
values for $r/(1-n_\mathrm{S})$. They are sometimes referred to as intrinsic
features of inflation itself. In this paper we first show that the
phenomenological class of inflationary potentials sampled by horizon-flow is
directly responsible for such predictions. They are therefore anything but
generic. Furthermore, the horizon-flow setup is shown to rely on trajectories
in phase space that differ from the slow-roll. For a given potential, we
demonstrate that this renders horizon-flow blind to entire relevant
inflationary regimes, for which the horizon-flow trajectory is shown to be
unstable. This makes horizon-flow a biased parameterization of inflation.


title: Fast radio bursts as a cosmic probe?

abstract:
  We discuss the possibility of using fast radio bursts (FRBs), if
cosmological, as a viable cosmic probe. We find out that the contribution of
the host galaxies to the detected dispersion measures can be inapparent for the
FRBs not from galaxy centers or star forming regions. The inhomogeneity of the
intergalactic medium (IGM), however, causes significant deviation of the
dispersion measure from that predicted in the simplified homogeneous IGM model
for individual event. Fortunately, with sufficient FRBs along different
sightlines but within a very narrow redshift interval (e.g., $\Delta z \sim
0.05$ or $\Delta z \sim 0.05(1+z)$), the mean from averaging observed
dispersion measures does not suffer such a problem and hence may be used as a
cosmic probe. We show that in the optimistic case (e.g., tens FRBs in each
$\Delta z$ have been measured; the most distant FRBs were at redshift $\geq 3$;
the host galaxies and the FRB sources contribute little to the detected
dispersion measures) and with all the uncertainties (i.e. the inhomogeneity of
the IGM, the contribution and uncertainty of host galaxies as well as the
evolution and error of $f_{\rm IGM}$) considered, FRBs could help constrain the
equation of state of dark energy.