title:
Reunion probabilities of $N$ one-dimensional random walkers with mixed
  boundary conditions

abstract:
  In this work we extend the results of the reunion probability of $N$
one-dimensional random walkers to include mixed boundary conditions between
their trajectories. The level of the mixture is controlled by a parameter $c$,
which can be varied from $c=0$ (independent walkers) to $c\to\infty$ (vicious
walkers). The expressions are derived by using Quantum Mechanics formalism
(QMf) which allows us to map this problem into a Lieb-Liniger gas (LLg) of $N$
one-dimensional particles. We use Bethe ansatz and Gaudin's conjecture to
obtain the normalized wave-functions and use this information to construct the
propagator. As it is well-known, depending on the boundary conditions imposed
at the endpoints of a line segment, the statistics of the maximum heights of
the reunited trajectories have some connections with different ensembles in
Random Matrix Theory (RMT). Here we seek to extend those results and consider
four models: absorbing, periodic, reflecting, and mixed. In all four cases, the
probability that the maximum height is less or equal than $L$ takes the form
$F_N(L)=A_N\sum_{k\in\Omega_{B}}\int Dz
e^{-\sum_{j=1}^Nk_j^2+G_N(k)-\sum_{j,\ell=1}^N
z_jV_{j\ell}(k)\overline{z}_\ell}$, where $A_N$ is a normalization constant,
$G_N(k)$ and $V_{j\ell}(k)$ depend on the type of boundary condition, and
$\Omega_{B}$ is the solution set of quasi-momenta $k$ obeying the Bethe
equations for that particular boundary condition.


title:
H\"older regularity of arithmetic Fourier series arising from modular
  forms

abstract:
  Given a modular form which is not a cusp form
$M_k(z)=\sum_{n=0}^{\infty}r_ne^{2\pi inz}$ of weight $k \geq 4$, we define the
series $M_{k,s}(x)=\sum_{n=1}^{\infty}\frac{r_n}{n^s}\sin(2\pi nx),$ which
converges for all $x\in\mathbb{R}$ when $s>k$. In this paper, we compute the
H\"{o}lder regularity exponent of $M_{k,s}$ at irrational points. In our
analysis we apply wavelets methods proposed by Jaffard in 1996 in the study of
the Riemann series. We find that the H\"{o}lder regularity exponent at a point
$x$ is related to the fine diophantine properties of $x$, in a very precise
way.


title:
Explaining the behavior of joint and marginal Monte Carlo estimators in
  latent variable models with independence assumptions

abstract:
  In latent variable models the parameter estimation can be implemented by
using the joint or the marginal likelihood, based on independence or
conditional independence assumptions. The same dilemma occurs within the
Bayesian framework with respect to the estimation of the Bayesian marginal (or
integrated) likelihood, which is the main tool for model comparison and
averaging. In most cases, the Bayesian marginal likelihood is a high
dimensional integral that cannot be computed analytically and a plethora of
methods based on Monte Carlo integration (MCI) are used for its estimation. In
this work, it is shown that the joint MCI approach makes subtle use of the
properties of the adopted model, leading to increased error and bias in finite
settings. The sources and the components of the error associated with
estimators under the two approaches are identified here and provided in exact
forms. Additionally, the effect of the sample covariation on the Monte Carlo
estimators is examined. In particular, even under independence assumptions the
sample covariance will be close to (but not exactly) zero which surprisingly
has a severe effect on the estimated values and their variability. To address
this problem, an index of the sample's divergence from independence is
introduced as a multivariate extension of covariance. The implications
addressed here are important in the majority of practical problems appearing in
Bayesian inference of multi-parameter models with analogous structures.


title:
Detrending moving-average cross-correlation coefficient: Measuring
  cross-correlations between non-stationary series

abstract:
  In the paper, we introduce a new measure of correlation between possibly
non-stationary series. As the measure is based on the detrending moving-average
cross-correlation analysis (DMCA), we label it as the DMCA coefficient
$\rho_{DMCA}(\lambda)$ with a moving average window length $\lambda$. We
analytically show that the coefficient ranges between -1 and 1 as a standard
correlation does. In the simulation study, we show that the values of
$\rho_{DMCA}(\lambda)$ very well correspond to the true correlation between the
analyzed series regardless the (non-)stationarity level. Dependence of the
newly proposed measure on other parameters -- correlation level, moving average
window length and time series length -- is discussed as well.


title: Spectral Gaps of Almost Mathieu Operator in Exponential Regime

abstract:
  For almost Mathieu operator
$(H_{\lambda,\alpha,\theta}u)_n=u_{n+1}+u_{n-1}+2\lambda
\cos2\pi(\theta+n\alpha)u_n$, the dry version of Ten Martini problem predicts
that the spectrum $\Sigma_{\lambda,\alpha}$ of $ H_{\lambda,\alpha,\theta}$ has
all gaps open for all $\lambda\neq 0$ and $ \alpha \in \mathbb{R}\backslash
\mathbb{Q}$.
  Avila and Jitomirskaya prove that $\Sigma_{\lambda,\alpha}$ has all gaps open
for Diophantine $\alpha$ and $0<|\lambda|<1$.
  In the present paper, we show that $\Sigma_{\lambda,\alpha}$ has all gaps
open for all $ \alpha \in \mathbb{R}\backslash \mathbb{Q}$ with small
$\lambda$.


title: Non-local spectroscopy of Andreev bound states

abstract:
  We experimentally investigate Andreev bound states (ABSs) in a carbon
nanotube quantum dot (QD) connected to a superconducting Nb lead (S). A weakly
coupled normal metal contact acts as a tunnel probe that measures the energy
dispersion of the ABSs. Moreover we study the response of the ABS to non-local
transport processes, namely Cooper pair splitting and elastic co-tunnelling,
that are enabled by a second QD fabricated on the same nanotube on the opposite
side of S. We find an appreciable non-local conductance with a rich structure,
including a sign reversal at the ground state transition from the ABS singlet
to a degenerate magnetic doublet. We describe our device by a simple rate
equation model that captures the key features of our observations and
demonstrates that the sign of the non-local conductance is a measure for the
charge distribution of the ABS, given by the respective Bogoliubov-de Gennes
amplitudes $u$ and $v$.


title: Identifying Clusters in Bayesian Disease Mapping

abstract:
  Disease mapping is the field of spatial epidemiology interested in estimating
the spatial pattern in disease risk across $n$ areal units. One aim is to
identify units exhibiting elevated disease risks, so that public health
interventions can be made. Bayesian hierarchical models with a spatially smooth
conditional autoregressive prior are used for this purpose, but they cannot
identify the spatial extent of high-risk clusters. Therefore we propose a two
stage solution to this problem, with the first stage being a spatially adjusted
hierarchical agglomerative clustering algorithm. This algorithm is applied to
data prior to the study period, and produces $n$ potential cluster structures
for the disease data. The second stage fits a separate Poisson log-linear model
to the study data for each cluster structure, which allows for step-changes in
risk where two clusters meet. The most appropriate cluster structure is chosen
by model comparison techniques, specifically by minimising the Deviance
Information Criterion. The efficacy of the methodology is established by a
simulation study, and is illustrated by a study of respiratory disease risk in
Glasgow, Scotland.


title: Flux saturation length of sediment transport

abstract:
  Sediment transport along the surface drives geophysical phenomena as diverse
as wind erosion and dune formation. The main length-scale controlling the
dynamics of sediment erosion and deposition is the saturation length
$L_\mathrm{s}$, which characterizes the flux response to a change in transport
conditions. Here we derive, for the first time, an expression predicting
$L_\mathrm{s}$ as a function of the average sediment velocity under different
physical environments. Our expression accounts for both the characteristics of
sediment entrainment and the saturation of particle and fluid velocities, and
has only two physical parameters which can be estimated directly from
independent experiments. We show that our expression is consistent with
measurements of $L_\mathrm{s}$ in both aeolian and subaqueous transport regimes
over at least five orders of magnitude in the ratio of fluid and particle
density, including on Mars.

categories: cond-mat.soft astro-ph.EP physics.ao-ph physics.geo-ph


title:
Linear Estimating Equations for Exponential Families with Application to
  Gaussian Linear Concentration Models

abstract:
  In many families of distributions, maximum likelihood estimation is
intractable because the normalization constant for the density which enters
into the likelihood function is not easily available. The score matching
estimator of Hyv\"arinen (2005) provides an alternative where this
normalization constant is not required. The corresponding estimating equations
become linear for an exponential family. The score matching estimator is shown
to be consistent and asymptotically normally distributed for such models,
although not necessarily efficient. Gaussian linear concentration models are
examples of such families. For linear concentration models that are also linear
in the covariance we show that the score matching estimator is identical to the
maximum likelihood estimator, hence in such cases it is also efficient.
Gaussian graphical models and graphical models with symmetries form
particularly interesting subclasses of linear concentration models and we
investigate the potential use of the score matching estimator for this case.


title:
De-Virtualizing Social Events: Understanding the Gap between Online and
  Offline Participation for Event Invitations

abstract:
  One growing use of computer-based communication media is for gathering people
to initiate or sustain social events. Although the use of computer-mediated
communication and social network sites such as Facebook for event promotion is
becoming popular, online participation in an event does not always translate to
offline attendance. In this paper, we report on an interview study of 31
participants that examines how people handle online event invitations and what
influences their online and offline participation. The results show that
people's event participation is shaped by their social perceptions of the
event's nature (e.g., public or private), their relationships to others (e.g.,
the strength of their connections to other invitees), and the medium used to
communicate event information (e.g., targeted invitation via email or spam
communication via Facebook event page). By exploring how people decide whether
to participate online or offline, the results illuminate the sophisticated
nature of the mechanisms that affect participation and have design implications
that can bridge virtual and real attendance.


title:
Atomically perfect torn graphene edges and their reversible
  reconstruction

abstract:
  The atomic structure of graphene edges is critical in determining the
electrical, magnetic, and chemical properties of truncated graphene structures,
notably nanoribbons. Unfortunately, graphene edges are typically far from ideal
and suffer from atomic-scale defects, structural distortion, and unintended
chemical functionalization, leading to unpredictable properties. Here we report
that graphene edges fabricated by electron-beam-initiated mechanical rupture or
tearing in high vacuum are clean and largely atomically perfect, oriented in
either the armchair or zigzag direction. Via aberration-corrected transmission
electron microscopy, we demonstrate reversible and extended pentagon-heptagon
(5-7) reconstruction at zigzag edges, and explore experimentally and
theoretically the dynamics of the transitions between configuration states.
Good theoretical-experimental agreement is found for the flipping rates between
5-7 and 6-6 zigzag edge states. Our study demonstrates that simple ripping is
remarkably effective in producing atomically clean, ideal terminations thus
providing a valuable tool for realizing atomically-tailored graphene and
facilitating meaningful experimental study.


title:
Profiles for bounded solutions of dispersive equations, with
  applications to energy-critical wave and Schr\"odinger equations

abstract:
  Consider a bounded solution of the focusing, energy-critical wave equation
that does not scatter to a linear solution. We prove that this solution
converges in some weak sense, along a sequence of times and up to scaling and
space translation, to a sum of solitary waves. This result is a consequence of
a new general compactness/rigidity argument based on profile decomposition. We
also give an application of this method to the energy-critical Schr\"odinger
equation.


title:
The Gaussian-Smoothed Wigner Function and Its Application to Precision
  Analysis

abstract:
  We study a class of phase-space distribution functions that is generated from
a Gaussian convolution of the Wigner distribution function. This class of
functions represents the joint count probability in simultaneous measurements
of position and momentum. We show that, using these functions, one can
determine the expectation value of a certain class of operators accurately,
even if measurement data performed only with imperfect detectors are available.
As an illustration, we consider the eight-port homodyne detection experiment
that performs simultaneous measurements of two quadrature amplitudes of a
radiation field.


title: Developing a Visual Interactive Search History Exploration System

abstract:
  As users advance in their search within a system, different queries are
conducted and various results are examined by them. These objects form an
implicit individual library representing the acquired knowledge. In our
research we aim to supply the user with visualizations of the search history
and interaction methods to organize the history. The fundamental question is
what role search history exploration can play in the users search process. In
this paper we want to introduce Ideas of a prototypical system for search
history exploration and discuss methods to address the questions mentioned
above.


title: Magnetically powered outbursts from white dwarf mergers

abstract:
  Merger of a white dwarf binary creates a differentially rotating object which
is expected to generate strong magnetic fields. Kinetic energy stored in
differential rotation is partially dissipated in the magnetically dominated
corona, which forms a hot variable outflow with ejection velocity comparable to
$10^9$ cm s$^{-1}$. The outflow should carry significant mass and energy for
hours to days, creating an expanding fireball with the following features. (i)
The fireball is initially opaque and its internal energy is dominated by the
trapped thermal radiation. The stored heat is partially converted to kinetic
energy of the flow (through adiabatic cooling) and partially radiated away.
(ii) Internal shocks develop in the fireball and increase its radiative output.
(iii) A significant fraction of the emitted energy is in the optical band. As a
result, a bright optical transient with luminosity $L\sim 10^{41}-10^{42}$ erg
s$^{-1}$ and a characteristic peak duration comparable to 1 day may be expected
from the merger. In contrast to classical novae or supernovae, the transient
does not involve nuclear energy. The decay after its peak reflects the damping
of differential rotation in the merger remnant. Such outbursts may be detected
in the local Universe with current and upcoming optical surveys.


title:
H\"{o}lder Continuity of the Spectral Measures for One-Dimensional
  Schr\"{o}dinger Operator in Exponential Regime

abstract:
  Avila and Jitomirskaya prove that the spectral measure $\mu_{\lambda v,
\alpha,x}^f$ of quasi-periodic Schr\"{o}dinger operator is $1/2$-H\"{o}lder
continuous with appropriate initial vector $f$, if $\alpha $ satisfies
Diophantine condition and $\lambda$ is small. In the present paper, the
conclusion is extended to that for all $\alpha$ with $\beta(\alpha)<\infty$,
the spectral measure $\mu_{\lambda v, \alpha,x}^f$ is $1/2$-H\"{o}lder
continuous with small $\lambda$, if $v$ is real analytic in a neighbor of
$\{|\Im x|\leq C\beta\}$, where $C$ is a large absolute constant. In
particular, the spectral measure $\mu_{\lambda, \alpha,x}^f$ of almost Mathieu
operator is $1/2$-H\"{o}lder continuous if $|\lambda|<e^{-C\beta}$ with $C$ a
large absolute constant.


title: On the origin of X-ray spectra in luminous blazars

abstract:
  Gamma-ray luminosities of some quasar-associated blazars imply jet powers
reaching values comparable to the accretion power even if assuming very strong
Doppler boosting and very high efficiency of gamma-ray production. With much
lower radiative efficiencies of protons than of electrons, and the recent
reports of very strong coupling of electrons with shock-heated protons
indicated by Particle-in-Cell (PIC) simulations, the leptonic models seem to be
strongly favored over the hadronic ones. However, the electron-proton coupling
combined with the ERC (External-Radiation-Compton) models of gamma-ray
production in leptonic models predict extremely hard X-ray spectra, with energy
indices about 0. This is inconsistent with the observed 2-10 keV slopes of
blazars, which cluster around an index value of 0.6. This problem can be
resolved by assuming that electrons can be cooled down radiatively to
non-relativistic energies, or that blazar spectra are entirely dominated by the
SSC (Synchrotron-Self Compton) component up to at least 10 keV. Here, we show
that the required cooling can be sufficiently efficient only at distances r <
0.03pc. SSC spectra, on the other hand, can be produced roughly co-spatially
with the observed synchrotron and ERC components, which are most likely located
roughly at a parsec scale. We show that the dominant SSC component can also be
produced much further than the dominant synchrotron and ERC components, at
distances larger than 10 parsecs. Hence, depending on the spatial distribution
of the energy dissipation along the jet, one may expect to see
gamma-ray/optical events with either correlated or uncorrelated X-rays. In all
cases the number of electron-positron pairs per proton is predicted to be very
low. The direct verification of the proposed SSC scenario requires sensitive
observations in the hard X-ray band which is now possible with the NuSTAR
satellite.


title: Homogeneous locally conformally K\"ahler manifolds

abstract:
  It is known that automorphism group $G$ of a compact homogeneous locally
conformally K\"ahler manifold $M=G/H$ has at least a 1-dimensional center. We
prove that the center of $G$ is at most 2-dimensional, and that if its
dimension is 2, then $M$ is Vaisman and isometric to a mapping torus of an
isometry of a homogeneous Sasakian manifold.


title: The Schramm-Loewner equation for multiple slits

abstract:
  We prove that any disjoint union of finitely many simple curves in the upper
half-plane can be generated in a unique way by the chordal multiple-slit
Loewner equation with constant weights.


title: Large magnetocapacitance in electronic ferroelectric manganite systems

abstract:
  We have observed a sizable positive magnetocapacitance ($\sim$$5-90\%$) in
perovskite Pr$_{0.55}$Ca$_{0.45}$MnO$_3$ and bilayer
Pr(Sr$_{0.1}$Ca$_{0.9}$)$_2$Mn$_2$O$_7$ system under 5T magnetic field across
20-100 K below the magnetic transition point T$_N$. The magnetodielectric
effect, on the other hand, exhibits a crossover: (a) from positive to negative
for the perovskite system and (b) from negative to positive for the bilayer
system over the same temperature range. The bilayer
Pr(Sr$_{0.1}$Ca$_{0.9}$)$_2$Mn$_2$O$_7$ system exhibits a sizable anisotropy as
well. We have also noticed the influence of magnetic field on the dielectric
relaxation characteristics of these systems. These systems belong to a class of
improper ferroelectrics and are expected to exhibit charge/orbital order driven
ferroelectric polarization below the transition point T$_{CO}$. Large
magnetocapacitance in these systems shows typical multiferroic behavior even
though the ferroelectric polarization is small in comparison to that of other
ferroelectrics.


title:
On the use of marginal posteriors in marginal likelihood estimation via
  importance-sampling

abstract:
  We investigate the efficiency of a marginal likelihood estimator where the
product of the marginal posterior distributions is used as an
importance-sampling function. The approach is generally applicable to
multi-block parameter vector settings, does not require additional Markov Chain
Monte Carlo (MCMC) sampling and is not dependent on the type of MCMC scheme
used to sample from the posterior. The proposed approach is applied to normal
regression models, finite normal mixtures and longitudinal Poisson models, and
leads to accurate marginal likelihood estimates.


title:
On strong binomial approximation for stochastic processes and
  applications for financial modelling

abstract:
  This paper considers binomial approximation of continuous time stochastic
processes. It is shown that, under some mild integrability conditions, a
process can be approximated in mean square sense and in other strong metrics by
binomial processes, i.e., by processes with fixed size binary increments at
sampling points. Moreover, this approximation can be causal, i.e., at every
time it requires only past historical values of the underlying process. In
addition, possibility of approximation of solutions of stochastic differential
equations by solutions of ordinary equations with binary noise is established.
Some consequences for the financial modelling and options pricing models are
discussed.


title:
Non-reciprocal Oersted field contribution to the current-induced
  frequency shift of magnetostatic surface waves

abstract:
  The influence of an electrical current on the propagation of magnetostatic
surface waves is investigated in a relatively thick (40 nm) permalloy film both
experimentally and theoretically. Contrary to previously studied thinner films
where the dominating effect is the current-induced spin-wave Doppler shift, the
magnetic field generated by the current (Oersted field) is found to induce a
strong non-reciprocal frequency shift which overcompensates the Doppler shift.
The measured current induced frequency shift is in agreement with the developed
theory. The theory relates the sign of of the frequency shift to the spin wave
modal profiles. The good agreement between the experiment and the theory
confirms a recent prediction of a counter-intuitive mode localization for
magnetostatic surface waves in the dipole-exchange regime.


title:
Rogosinski's lemma for univalent functions, hyperbolic Archimedean
  spirals and the Loewner equation

abstract:
  We describe the region $\mathcal{V}(z_0)$ of values of $f(z_0)$ for all
normalized bounded univalent functions $f$ in the unit disk $\mathbb{D}$ at a
fixed point $z_0 \in \mathbb{D}$. The proof is based on identifying
$\mathcal{V}(z_0)$ as the reachable set of the radial Loewner differential
equation. We also prove an analogous result for the upper half-plane using the
chordal Loewner equation.


title: A light SUSY dark matter after CDMS-II, LUX and LHC Higgs data

abstract:
  In SUSY, a light dark matter is usually accompanied by light scalars to
achieve the correct relic density, which opens new decay channels of the SM
like Higgs boson. Under current experimental constraints including the latest
LHC Higgs data and the dark matter relic density, we examine the status of a
light neutralino dark matter in the framework of NMSSM and confront it with the
direct detection results of CoGeNT, CDMS-II and LUX. We have the following
observations: (i) A dark matter as light as 8 GeV is still allowed and its
scattering cross section off the nucleon can be large enough to explain the
CoGeNT/CDMS-II favored region; (ii) The LUX data can exclude a sizable part of
the allowed parameter space, but still leaves a light dark matter viable; (iii)
The SM-like Higgs boson can decay into the light dark matter pair with an
invisible branching ratio reaching 30% under the current LHC Higgs data, which
may be tested at the 14 TeV LHC experiment.


title: Integrable Systems Related to Deformed $\mathfrak{so}(5)$

abstract:
  We investigate a family of integrable Hamiltonian systems on Lie-Poisson
spaces $\mathcal{L}_+(5)$ dual to Lie algebras $\mathfrak{so}_{\lambda,
\alpha}(5)$ being two-parameter deformations of $\mathfrak{so}(5)$. We
integrate corresponding Hamiltonian equations on $\mathcal{L}_+(5)$ and
$T^*\mathbb{R}^5$ by quadratures as well as discuss their possible physical
interpretation.


title: Geo-located Twitter as the proxy for global mobility patterns

abstract:
  In the advent of a pervasive presence of location sharing services
researchers gained an unprecedented access to the direct records of human
activity in space and time. This paper analyses geo-located Twitter messages in
order to uncover global patterns of human mobility. Based on a dataset of
almost a billion tweets recorded in 2012 we estimate volumes of international
travelers in respect to their country of residence. We examine mobility
profiles of different nations looking at the characteristics such as mobility
rate, radius of gyration, diversity of destinations and a balance of the
inflows and outflows. The temporal patterns disclose the universal seasons of
increased international mobility and the peculiar national nature of overseen
travels. Our analysis of the community structure of the Twitter mobility
network, obtained with the iterative network partitioning, reveals spatially
cohesive regions that follow the regional division of the world. Finally, we
validate our result with the global tourism statistics and mobility models
provided by other authors, and argue that Twitter is a viable source to
understand and quantify global mobility patterns.


title: Computation of the Marcum Q-function

abstract:
  Methods and an algorithm for computing the generalized Marcum $Q-$function
($Q_{\mu}(x,y)$) and the complementary function ($P_{\mu}(x,y)$) are described.
These functions appear in problems of different technical and scientific areas
such as, for example, radar detection and communications, statistics and
probability theory, where they are called the non-central chi-square or the non
central gamma cumulative distribution functions.
  The algorithm for computing the Marcum functions combines different methods
of evaluation in different regions: series expansions, integral
representations, asymptotic expansions, and use of three-term homogeneous
recurrence relations. A relative accuracy close to $10^{-12}$ can be obtained
in the parameter region $(x,y,\mu) \in [0,\,A]\times [0,\,A]\times [1,\,A]$,
$A=200$, while for larger parameters the accuracy decreases (close to
$10^{-11}$ for $A=1000$ and close to $5\times 10^{-11}$ for $A=10000$).


title: On the genus filtration of diagrams over two backbones

abstract:
  In this paper we compute the bivariate generating function of
$\gamma$-matchings over two backbones, filtered by the number of arcs and the
topological genus. $\gamma$-matchings over two backbones are chord-diagrams,
obtained via concatenation and nesting of irreducible shapes of topological
genus $\le \gamma$. We show that the key information is contained in the
polynomials counting these shapes and provide recursions that allow to compute
the latter. In particular we give a bijection between such irreducible shapes
over one and two backbones. We present two applications of our results. The
first is concerned with RNA-RNA interaction structures, obtained from the
$\gamma$-matchings via symbolic methods. We secondly show that, using
analytic-combinatorial methods, the topological genus satisfies a central limit
theorem.


title: The formation of multiple populations in the globular cluster 47 Tuc

abstract:
  We use the combination of photometric and spectroscopic data of 47 Tuc stars
to reconstruct the possible formation of a second generation of stars in the
central regions of the cluster, from matter ejected from massive Asymptotic
Giant Branch stars, diluted with pristine gas. The yields from massive AGB
stars with the appropriate metallicity (Z=0.004, i.e. [Fe/H]=-0.75) are
compatible with the observations, in terms of extension and slope of the
patterns observed, involving oxygen, nitrogen, sodium and aluminium. Based on
the constraints on the maximum helium of 47 Tuc stars provided by photometric
investigations, and on the helium content of the ejecta, we estimate that the
gas out of which second generation stars formed was composed of about one-third
of gas from intermediate mass stars, with M>= 5Mo and about two-thirds of
pristine gas. We tentatively identify the few stars whose Na, Al and O
abundances resemble the undiluted AGB yields with the small fraction of 47 Tuc
stars populating the faint subgiant branch. From the relative fraction of first
and second generation stars currently observed, we estimate that the initial FG
population in 47 Tuc was about 7.5 times more massive than the cluster current
total mass.


title:
Uniform generation of RNA-RNA interaction structures of fixed
  topological genus

abstract:
  Interacting RNA complexes are studied via bicellular maps using a filtration
via their topological genus. Our main result is a new bijection for RNA-RNA
interaction structures and linear time uniform sampling algorithm for RNA
complexes of fixed topological genus. The bijection allows to either reduce the
topological genus of a bicellular map directly, or to lose connectivity by
decomposing the complex into a pair of single stranded RNA structures. Our main
result is proved bijectively. It provides an explicit algorithm of how to
rewire the corresponding complexes and an unambiguous decomposition grammar.
Using the concept of genus induction, we construct bicellular maps of fixed
topological genus $g$ uniformly in linear time. We present various statistics
on these topological RNA complexes and compare our findings with biological
complexes. Furthermore we show how to construct loop-energy based complexes
using our decomposition grammar.


title: Compact Stirling cooling of astronomical detectors

abstract:
  MAIA, a three-channel imager targeting fast cadence photometry, was recently
installed on the Mercator telescope (La Palma, Spain). This instrument observes
a 9.4 x 14.1 arcmin field of view simultaneously in three color bands ($u$, $g$
and $r$), using three of the largest (un-) available frame-transfer CCDs,
namely the 2k x 6k CCD42-C0 from e2v. As these detectors are housed in three
separate cryostats, compact cooling devices are required that offer sufficient
power to cool the large chips to a temperature of 165K. We explored a broad
spectrum of cooling options and technologies to cool the MAIA detectors.
Finally, compact free-piston Stirling coolers were selected, namely the CryoTel
MT cryo-coolers from SUNPOWER, that can extract 5W of heat at a temperature of
77K. In this contribution we give details of the MAIA detector cooling
solution. We also discuss the general usability of this type of closed-cycle
cryo-coolers for astronomical detectors. They offer distinct advantages but the
vibrations caused by mechanical cryo-cooling impose a serious drawback. We
present a solution to mechanically decouple the coolers from the instrument and
show some results of how this reduces the vibrations to a level that is
acceptable for most applications on astronomical telescopes.


title: Particle Metropolis-Hastings using gradient and Hessian information

abstract:
  Particle Metropolis-Hastings (PMH) allows for Bayesian parameter inference in
nonlinear state space models by combining Markov chain Monte Carlo (MCMC) and
particle filtering. The latter is used to estimate the intractable likelihood.
In its original formulation, PMH makes use of a marginal MCMC proposal for the
parameters, typically a Gaussian random walk. However, this can lead to a poor
exploration of the parameter space and an inefficient use of the generated
particles.
  We propose a number of alternative versions of PMH that incorporate gradient
and Hessian information about the posterior into the proposal. This information
is more or less obtained as a byproduct of the likelihood estimation. Indeed,
we show how to estimate the required information using a fixed-lag particle
smoother, with a computational cost growing linearly in the number of
particles. We conclude that the proposed methods can: (i) decrease the length
of the burn-in phase, (ii) increase the mixing of the Markov chain at the
stationary phase, and (iii) make the proposal distribution scale invariant
which simplifies tuning.


title: Quasiconformal embeddings of Y-pieces

abstract:
  In this paper we construct quasiconformal embeddings from Y-pieces that
contain a short boundary geodesic into degenerate ones. These results are used
in a companion paper to study the Jacobian tori of Riemann surfaces that
contain small simple closed geodesics.


title: Affine HJM Framework on $S_{d}^{+}$ and Long-Term Yield

abstract:
  We develop the HJM framework for forward rates driven by affine processes on
the state space of symmetric positive matrices. In this setting we find a
representation for the long-term yield and investigate the yield's asymptotic
behaviour.


title:
Particle filter-based Gaussian process optimisation for parameter
  inference

abstract:
  We propose a novel method for maximum likelihood-based parameter inference in
nonlinear and/or non-Gaussian state space models. The method is an iterative
procedure with three steps. At each iteration a particle filter is used to
estimate the value of the log-likelihood function at the current parameter
iterate. Using these log-likelihood estimates, a surrogate objective function
is created by utilizing a Gaussian process model. Finally, we use a heuristic
procedure to obtain a revised parameter iterate, providing an automatic
trade-off between exploration and exploitation of the surrogate model. The
method is profiled on two state space models with good performance both
considering accuracy and computational cost.


title: On Some Idempotent and Non-Associative Convex Structure

abstract:
  $\mathbb B$-convexity was defined in [7] as a suitable Kuratowski-Painlev\'e
upper limit of linear convexities over a finite dimensional Euclidean vector
space. Excepted in the special case where convex sets are subsets of $\mathbb
R^n_ +$, $\mathbb B$-convexity was not defined with respect to a given explicit
algebraic structure. This is done in that paper, which proposes an extension of
$\mathbb B$-convexity to the whole Euclidean vector space. An unital idempotent
and non-associative magma is defined over the real set and an extended $n$-ary
operation is introduced. Along this line, the existence of the
Kuratowski-Painlev\'e limit of the convex hull of two points over $\mathbb R^n$
is shown and an explicit extension of $\mathbb B$-convexity is proposed.


title:
Probing the wavefunction of the surface states in Bi$_2$Se$_3$
  topological insulator: a realistic tight-binding approach

abstract:
  We report on microscopic tight-binding modeling of surface states in
Bi$_2$Se$_3$ three-dimensional topological insulator, based on a sp$^3$
Slater-Koster Hamiltonian, with parameters calculated from density functional
theory. The effect of spin-orbit interaction on the electronic structure of the
bulk and of a slab with finite thickness is investigated. In particular, a
phenomenological criterion of band inversion is formulated for both bulk and
slab, based on the calculated atomic- and orbital-projections of the
wavefunctions, associated with valence and conduction band extrema at the
center of the Brillouin zone. We carry out a thorough analysis of the
calculated bandstructures of slabs with varying thickness, where surface states
are identified using a quantitative criterion according to their spatial
distribution. The thickness-dependent energy gap, attributed to inter-surface
interaction, and the emergence of gapless surface states for slabs above a
critical thickness are investigated. We map out the transition to the
infinite-thickness limit by calculating explicitly the modifications in the
spatial distribution and spin-character of the surface states wavefunction with
increasing the slab thickness. Our numerical analysis shows that the system
must be approximately forty quintuple-layers thick to exhibit completely
decoupled surface states, localized on the opposite surfaces. These results
have implications on the effect of external perturbations on the surface states
near the Dirac point.


title: Localized Penrose inequality for the Liu-Yau mass in spherical symmetry

abstract:
  For an asymptotically flat initial data, the Penrose inequality gives a lower
bound of the Arnowitt-Deser-Misner total mass of a spacetime in terms of the
area of certain surfaces representing black holes. This is a deep and beautiful
refinement of the famous positive mass theorem and it plays an important role
in the study of gravitational collapse. Gravitational collapse can also happen
if sufficient mass is concentrated into a finite region. This motivates us to
seek a localized version of the Penrose inequality. In this Letter, we
successfully make a precise statement of this form for the Liu-Yau quasi-local
mass in spherical symmetry.


title:
Electroweak structure of light nuclei within chiral effective field
  theory

abstract:
  We review the results of the most recent calculations for the electromagnetic
structure of light nuclei, the weak muon capture on deuteron and 3He and the
weak proton-proton capture reaction at energies of astrophysical interest,
performed within the chiral effective field theory framework.


title: Blowup solutions of elliptic systems in two dimensional spaces

abstract:
  This is the content of the talk the author gave in the section of partial
differential equations at the International Congress of Chinese Mathematicians,
2013, Taipei.


title: Random walk on a diagonal lattice with absorbing boundaries

abstract:
  We consider a discrete random walk on a diagonal lattice in two and three
dimensions and obtain explicit solutions of absorption probabilities and
probabilities of return in several domains. In three dimensions we consider
both the cube and the dodecahedron variant. In two dimensions we obtain
explicit formula in case of rotated barriers.


title:
Frequency lock closed-loop control of a separated flow using visual
  feedback

abstract:
  In this study, a simple model based closed-loop algorithm is used to control
the separated flow downstream a backward-facing step. It has been shown in
previous studies that the recirculation bubble can be minimized when exciting
the shear layer at its natural Kelvin-Helmholtz instability frequency. In this
experiment, the natural shedding frequency is identified through real-time
analysis of 2D velocity fields. Actuation (pulsed jet) is then locked on this
frequency. If flow characteristics stray too far from a set point, shedding
frequency is updated and actuation changed. The present work demonstrates the
efficacy and robustness of this approach in reducing recirculation while
Reynolds number is randomly varied between 1400 and 2800.


title: A more general framework for coGalois theory

abstract:
  The paper is an extended version of a talk given at the International
Conference: Experimental and Theoretical Methods in Algebra, Geometry and
Topology, which took place June 21--24, 2013 in Eforie Nord (Romania). Its
purpose is to present a more general framework for a fairly new theory in Field
Theory, called coGalois Theory, which is somewhat dual to the very classical
Galois Theory and is more general than the Kummer Theory. The main object of
investigation in this more general framework is the coGalois connexion
naturally associated to any triple $\,(\Gamma, \frak{G}, \eta)\,$, where
$\,\Gamma\,$ is a profinite group, $\,\frak{G}\,$ is a profinite operator
$\,\Gamma$-group, and $\,\eta: \Gamma \longrightarrow \frak{G}\,$ is a
continuous $\,1$-cocycle with the property that the profinite group
$\,\frak{G}\,$ is topologically generated by the image $\,\eta(\Gamma)$.


title:
Shape resonances and shell effects in thin-film multiband
  superconductors

abstract:
  We study analytically the evolution of superconductivity in clean
quasi-two-dimensional multiband supercon- ductors as the film thickness enters
the nanoscale region by mean-field and semiclassical techniques. Tunneling into
the substrate and finite lateral size effects, which are important in
experiments, are also considered in our model. As a result, it is possible to
investigate the interplay between quantum coherence effects, such as shape
resonances and shell effects, with the potential to enhance superconductivity,
and the multiband structure and the coupling to the substrate that tend to
suppress it. The case of magnesium diboride, which is the conventional
superconductor with the highest critical temperature, is discussed in detail.
Once the effect of the substrate is considered, we still observe quantum size
effects such as the oscillation of the critical temperature with the thickness
but without a significant enhancement of superconductivity. In thin films with
a sufficiently longer superconducting coherence length, it is, however,
possible to increase the critical temperature above the bulk limit by tuning
the film thickness or lateral size.


title: Coherence trapping and information back-flow in dephasing qubits

abstract:
  We study the interplay between coherence trapping, information back-flow and
the form of the reservoir spectral density for dephasing qubits. We show that
stationary coherence is maximized when the qubit undergoes non-Markovian
dynamics, and we elucidate the different roles played by the low and high
frequency parts of the environmental spectrum. We show that the low frequencies
fully determine the presence or absence of information back-flow while the high
frequencies dictate the maximal amount of coherence trapping.


title: Smooth non-zero rest-mass evolution across time-like infinity

abstract:
  It is shown that solutions to Einstein's field equations with positive
cosmological constant can include non-zero rest-mass fields which coexist with
and travel unimpeded across a smooth conformal boundary. This is exemplified by
the coupled Einstein-massive-scalar field equations for which the mass $m$ is
related to the cosmological constant $\lambda$ by the relation $3\,m^2 =
2\,\lambda$. Cauchy data for the conformal field equations can in this case be
prescribed on the (compact, space-like) conformal boundary ${\cal J}^+$. Their
developments backwards in time induce a set of standard Cauchy data on
space-like slices for the Einstein-massive-scalar field equations which is open
in the set of all Cauchy data for this system.


title: On Fast Dropout and its Applicability to Recurrent Networks

abstract:
  Recurrent Neural Networks (RNNs) are rich models for the processing of
sequential data. Recent work on advancing the state of the art has been focused
on the optimization or modelling of RNNs, mostly motivated by adressing the
problems of the vanishing and exploding gradients. The control of overfitting
has seen considerably less attention. This paper contributes to that by
analyzing fast dropout, a recent regularization method for generalized linear
models and neural networks from a back-propagation inspired perspective. We
show that fast dropout implements a quadratic form of an adaptive,
per-parameter regularizer, which rewards large weights in the light of
underfitting, penalizes them for overconfident predictions and vanishes at
minima of an unregularized training loss. The derivatives of that regularizer
are exclusively based on the training error signal. One consequence of this is
the absense of a global weight attractor, which is particularly appealing for
RNNs, since the dynamics are not biased towards a certain regime. We positively
test the hypothesis that this improves the performance of RNNs on four musical
data sets.


title: On two- and three-point functions of Landau gauge Yang-Mills theory

abstract:
  We present results for the gluon and ghost propagators and the ghost-gluon
vertex obtained from Dyson-Schwinger equations. In the zero temperature case we
elaborate on the role of the three-gluon vertex and discuss a model that can
capture its qualitative features like its anomalous dimensions and a zero
crossing of the dressing function. Our results compare well with lattice data.
At non-zero temperature we calculated the ghost propagator which agrees rather
well with lattice results already within our simple truncation. These results
are used to obtain the temperature dependence of the ghost-gluon vertex. We
also explain why the ghost propagator does not react to the phase transition
despite its direct coupling to the chromoelectric gluon.


title:
Nuclear star formation activity and black hole accretion in nearby
  Seyfert galaxies

abstract:
  Recent theoretical and observational works indicate the presence of a
correlation between the star formation rate (SFR) and the active galactic
nuclei (AGN) luminosity (and, therefore, the black hole accretion rate) of
Seyfert galaxies. This suggests a physical connection between the gas forming
stars on kpc scales and the gas on sub-pc scales that is feeding the black
hole. We compiled the largest sample of Seyfert galaxies to date with high
angular resolution (0.4-0.8 arcsec) mid-infrared (8-13 micron) spectroscopy.
The sample includes 29 Seyfert galaxies drawn from the AGN Revised Shapley-Ames
catalogue. At a median distance of 33 Mpc, our data allow us to probe nuclear
regions on scales of 65 pc (median value). We found no general evidence of
suppression of the 11.3 micron polycyclic aromatic hydrocarbon (PAH) emission
in the vicinity of these AGN, and used this feature as a proxy for the SFR. We
detected the 11.3 micron PAH feature in the nuclear spectra of 45% of our
sample. The derived nuclear SFRs are, on average, five times lower than those
measured in circumnuclear regions of 600 pc in size (median value). However,
the projected nuclear SFR densities are a factor of 20 higher than those
measured on circumnuclear scales. This indicates that the SF activity per unit
area in the central 65 pc of Seyfert galaxies is much higher than at larger
distances from their nuclei. We studied the connection between the nuclear SFR
and the black hole accretion rate and showed that numerical simulations
reproduce fairly well our observed relation.


title:
Observing Dark Worlds: A crowdsourcing experiment for dark matter
  mapping

abstract:
  We present the results and conclusions from the citizen science competition
`Observing Dark Worlds', where we asked participants to calculate the positions
of dark matter halos from 120 catalogues of simulated weak lensing galaxy data,
using computational methods. In partnership with Kaggle
(http://www.kaggle.com), 357 users participated in the competition which saw
2278 downloads of the data and 3358 submissions. We found that the best
algorithms improved on the benchmark code, LENSTOOL by > 30% and could measure
the positions of > 3x10^14MSun halos to less than 5'' and < 10^14MSun to within
1'. In this paper, we present a brief overview of the winning algorithms with
links to available code. We also discuss the implications of the experiment for
future citizen science competitions.


title:
Hierarchical octree and k-d tree grids for 3D radiative transfer
  simulations

abstract:
  A crucial ingredient for numerically solving the 3D radiative transfer
problem is the choice of the grid that discretizes the transfer medium. Many
modern radiative transfer codes, whether using Monte Carlo or ray tracing
techniques, are equipped with hierarchical octree-based grids to accommodate a
wide dynamic range in densities. We critically investigate two different
aspects of octree grids in the framework of Monte Carlo dust radiative
transfer. Inspired by their common use in computer graphics applications, we
test hierarchical k-d tree grids as an alternative for octree grids. On the
other hand, we investigate which node subdivision-stopping criteria are optimal
for constructing of hierarchical grids. We implemented a k-d tree grid in the
3D radiative transfer code SKIRT and compared it with the previously
implemented octree grid. We also considered three different node
subdivision-stopping criteria (based on mass, optical depth, and density
gradient thresholds). Based on a small suite of test models, we compared the
efficiency and accuracy of the different grids, according to various quality
metrics. For a given set of requirements, the k-d tree grids only require half
the number of cells of the corresponding octree. Moreover, for the same number
of grid cells, the k-d tree is characterized by higher discretization accuracy.
Concerning the subdivision stopping criteria, we find that an optical depth
criterion is not a useful alternative to the more standard mass threshold,
since the resulting grids show a poor accuracy. Both criteria can be combined;
however, in the optimal combination, for which we provide a simple approximate
recipe, this can lead to a 20% reduction in the number of cells needed to reach
a certain grid quality. An additional density gradient threshold criterion can
be added that solves the problem of poorly resolving sharp edges and...
(abridged).


title:
Enumeration for the total number of all spanning forests of complete
  tripartite graph based on the combinatorial decomposition

abstract:
  This paper discusses the enumeration for the total number of all rooted
spanning forests of the labeled complete tripartite graph. We enumerate the
total number by a combinatorial decomposition.


title: Generative Modelling for Unsupervised Score Calibration

abstract:
  Score calibration enables automatic speaker recognizers to make
cost-effective accept / reject decisions. Traditional calibration requires
supervised data, which is an expensive resource. We propose a 2-component GMM
for unsupervised calibration and demonstrate good performance relative to a
supervised baseline on NIST SRE'10 and SRE'12. A Bayesian analysis demonstrates
that the uncertainty associated with the unsupervised calibration parameter
estimates is surprisingly small.


title: Non-homogeneous fractional Schr\"odinger equation

abstract:
  In this article we are interested on the non-homogeneous fractional
Schr\"odinger equation \begin{eqnarray}\label{eq00} &(-\Delta)^{\alpha}u(x) +
V(x)u(x) = f(u) + h(x) \mbox{ in } \mathbb{R}^{n}. \end{eqnarray} By using
mountain pass Thoerem and Ekeland's variational principle, we prove the
existence of two nontrivial solutions for (\ref{eq00}).


title: A novel soft keyboard for touchscreen phones: QWERT

abstract:
  The popularity of touchscreen phones has been growing around the world since
the iPhones and Android phones were released. More and more mobile phones with
large touchscreen have been produced, however, the phones with small size
displays are still in the majority of touch phones. The foremost interface on
touch smartphones is the information input module using soft keyboards.
Traditional input methods on touch phones have either too small key buttons
(such as QWERTY) or too many functions (such as 3$\times$4 keyboard), which are
inconvenient to use. Moreover, the conventional soft keyboards only use tapping
to input texts while current touch smartphones allow various gestures on the
touchscreen, such as sliding. In this paper, a novel soft keyboard called QWERT
is proposed for touchscreen-based smartphones. The users can interact with
phones via finger gestures of tapping or sliding when input text by using the
QWERT. In doing so, the interactions between users and smartphones will be
faster and easier. An experiment carried out on inexperienced human subjects
shows that they can learn very fast due to their familiarities with QWERTY. A
simulation experiment based on a cognitive architecture, ACT-R, was also
conducted to predict the movement time (MT) of experienced human subjects. The
simulation results show that the MT using QWERT outperforms other default
keyboards. These outcomes imply that the novel QWERT is a viable option for
touch smartphone users. Based on the novel design, an application is released
on Android systems. This application is expected to give better user experience
for customers who use touch smartphones.


title:
Product representation for default bilattices: an application of natural
  duality theory

abstract:
  Bilattices (that is, sets with two lattice structures) provide an algebraic
tool to model simultaneously the validity of, and knowledge about, sentences in
an appropriate language. In particular, certain bilattices have been used to
model situations in which information is prioritised and so can be viewed
hierarchically. These default bilattices are not interlaced: the lattice
operations of one lattice structure do not preserve the order of the other one.
The well-known product representation theorem for interlaced bilattices does
not extend to bilattices which fail to be interlaced and the lack of a product
representation has been a handicap to understanding the structure of default
bilattices. In this paper we study, from an algebraic perspective, a hierarchy
of varieties of default bilattices, allowing for different levels of default.
We develop natural dualities for these varieties and thereby obtain a concrete
representation for the algebras in each variety. This leads on to a form of
product representation that generalises the product representation as this
applies to distributive bilattices.


title:
Every finite acyclic quiver is a full subquiver of a quiver mutation
  equivalent to a bipartite quiver

abstract: We give a very short proof of the claim in the title.


title:
Well-posedness of the Cauchy problem for a fourth-order thin film
  equation via regularization approaches

abstract:
  This paper is devoted to some aspects of well-posedness of the Cauchy problem
for a quasilinear degenerate fourth-order parabolic thin film equation u_{t} =
-\nabla \cdot(|u|^{n} \nabla\D u) in \ren \times \re_+, \quad u(x,0)=u_0(x) in
\ren, where $n>0$ is a fixed exponent, with bounded smooth compactly supported
initial data. Dealing with the CP (for, at least, $n \in (0, \frac 32)$)
requires introducing classes of infinitely changing sign solutions that are
oscillatory close to finite interfaces.
  The main goal of the paper is to detect proper solutions of the CP for the
degenerate TFE--4 by uniformly parabolic analytic $\e$-regularizations at least
for values of the parameter $n$ sufficiently close to 0.


title: Edge covering with budget constrains

abstract:
  We study two related problems: finding a set of k vertices and minimum number
of edges (kmin) and finding a graph with at least m' edges and minimum number
of vertices (mvms).
  Goldschmidt and Hochbaum \cite{GH97} show that the mvms problem is NP-hard
and they give a 3-approximation algorithm for the problem. We improve
\cite{GH97} by giving a ratio of 2. A 2(1+\epsilon)-approximation for the
problem follows from the work of Carnes and Shmoys \cite{CS08}. We improve the
approximation ratio to 2. algorithm for the problem. We show that the natural
LP for \kmin has an integrality gap of 2-o(1). We improve the NP-completeness
of \cite{GH97} by proving the pronlem are APX-hard unless a well-known instance
of the dense k-subgraph admits a constant ratio. The best approximation
guarantee known for this instance of dense k-subgraph is O(n^{2/9})
\cite{BCCFV}. We show that for any constant \rho>1, an approximation guarantee
of \rho for the \kmin problem implies a \rho(1+o(1)) approximation for \mwms.
Finally, we define we give an exact algorithm for the density version of kmin.


title:
Quadrant asymmetry in the angular distribution of the Cosmic Microwave
  Background in the Planck satellite data

abstract:
  Some peculiar features found in the angular distribution of the cosmic
microwave background (CMB) measured by the Wilkinson Microwave Anisotropy Probe
(WMAP) deserve further investigation. Among these peculiar features, is the
quadrant asymmetry, which is likely related to the north-south asymmetry. In
this paper, we aim to extend the analysis of the quadrant asymmetry in the
$\Lambda$CDM framework to the Planck foreground-cleaned maps, using the mask
provided by Planck team. We compute the two-point correlation function (TPCF)
from each quadrant of the Planck CMB sky maps, and compare the result with 1000
Monte Carlo (MC) simulations generated assuming the $\Lambda$CDM best-fit power
spectrum. We detect the presence of an excess of power in the southeastern
quadrant (SEQ) and a significant lack of power in the northeastern quadrant
(NEQ) in the Planck data. Asymmetries between the SEQ and the other three
quadrants (southwestern quadrant (SWQ), northwestern quadrant (NWQ), and NEQ)
are each in disagreement with an isotropic sky at a 95\% confidence level.
Furthermore, by rotating the Planck temperature sky map with respect to z
direction, we showed the rotation angle where the TPCF of the SEQ has its
maximal power. Our analysis of the Planck foreground-cleaned maps shows that
there is an excess of power in the TPCF in the SEQ and a significant lack of
power in the NEQ when compared with simulations. This asymmetry is anomalous
when considering the $\Lambda$CDM framework .


title:
Probing moments of baryon-antibaryon generalized parton distributions at
  BELLE and FAIR

abstract:
  We analyze the time-like processes gamma gamma -> B Bbar and p p-bar -> gamma
M at large Mandelstam variables within the handbag approach for which the
process amplitudes factorize in hard partonic subprocesses and annihilation
form factor. The latter represent moments of baryon-antibaryon generalized
parton distributions. Symmetry relations restrict the number of independent
annihilation form factors for the ground state baryons drastically. We
determine these form factors from the present BELLE data on gamma gamma -> B
Bbar with the help of simplifying assumptions. The knowledge of these form
factors allow for predictions of p pbar -> gamma M for various mesons which may
be probed at FAIR.


title: Artificial Intelligence in Humans

abstract:
  In this paper, I put forward that in many instances, thinking mechanisms are
equivalent to artificial intelligence modules programmed into the human mind.


title: On certain diophantine equations of diagonal type

abstract:
  In this note we consider Diophantine equations of the form \begin{equation*}
a(x^p-y^q) = b(z^r-w^s), \quad \mbox{where}\quad
\frac{1}{p}+\frac{1}{q}+\frac{1}{r}+\frac{1}{s}=1, \end{equation*} with even
positive integers $p,q,r,s$. We show that in each case the set of rational
points on the underlying surface is dense in the Zariski topology. For the
surface with $(p,q,r,s)=(2,6,6,6)$ we prove density of rational points in the
Euclidean topology. Moreover, in this case we construct infinitely many
parametric solutions in coprime polynomials. The same result is true for
$(p,q,r,s)\in\{(2,4,8,8), (2,8,4,8)\}$. In the case $(p,q,r,s)=(4,4,4,4)$, we
present some new parametric solutions of the equation $x^4-y^4=4(z^4-w^4)$.


title:
Holographic thermalization with a chemical potential in Gauss-Bonnet
  gravity

abstract:
  Holographic thermalization is studied in the framework of
Einstein-Maxwell-Gauss-Bonnet gravity. We use the two-point correlation
function and expectation value of Wilson loop, which are dual to the
renormalized geodesic length and minimal area surface in the bulk, to probe the
thermalization. The numeric result shows that larger the Gauss-Bonnet
coefficient is, shorter the thermalization time is, and larger the charge is,
longer the thermalization time is, which implies that the Gauss-Bonnet
coefficient can accelerate the thermalization while the charge has an opposite
effect. In addition, we obtain the functions with respect to the thermalization
time for both the thermalization probes at a fixed charge and Gauss-Bonnet
coefficient, and on the basis of these functions, we obtain the thermalization
velocity, which shows that the thermalization process is non-monotonic. At the
middle and later periods of the thermalization process, we find that there is a
phase transition point, which divides the thermalization into an acceleration
phase and a deceleration phase. We also study the effect of the charge and
Gauss-Bonnet coefficient on the phase transition point.


title: An extremal problem on Hilbert cubes and complete r-partite hypergraphs

abstract:
  We construct a set of positive integers A in {1,..., n} with |A|>> n^{2/3}
that does not contain Hilbert cubes of dimension 3. As a consequence we prove
that ex(n; K^(3)(2,2,2))>> n^{8/3} where K^(3)(2,2,2) is the simplest complete
3-partite hypergraph. This is the first case of an improvement on the trivial
lower bound for ex(n; L) when L is a complete r-partite hypergraph.


title: Implications of the Higgs discovery for the MSSM

abstract:
  The implications of the discovery of the Higgs boson at the LHC with a mass
of approximately 125 GeV are summarised in the context of the minimal
supersymmetric extension of the Standard Model, the MSSM. Discussed are the
implications from the measured mass and production/decay rates of the observed
particle and from the constraints in the search for the heavier Higgs states at
the LHC.


title: Unavoidable collections of balls for censored stable processes

abstract:
  We study avoidability of collections of balls in bounded $C^{1,1}$ opens sets
for censored $\alpha$-stable processes, $\alpha\in (1,2)$. The results are
analog to the ones obtained for Brownian motion in S. J. Gardiner, M. Ghergu,
Champagne subregions of the unit ball with unavoidable bubbles, Ann. Acad. Sci.
Fenn. Math. 35 (2010) 321-329. On the way we derive a Wiener-Aikawa-type
criterion for minimal thinness with respect to the censored stable processes.


title: First integrals for nonlinear dispersive equations

abstract:
  Given a solution of a semilinear dispersive partial differential equation
with a real analytic nonlinearity, we relate its Cauchy data at two different
times by nonlinear representation formulas in terms of convergent series. These
series are constructed by means of generating functions. All this theory is
based on a new suitable formulation of the dynamics of solutions of dispersive
equations.


title:
Steady states, global existence and blow-up for fourth-order semilinear
  parabolic equations of Cahn--Hilliard type

abstract:
  Fourth-order semilinear parabolic equations of the Cahn--Hilliard-type (01)
u_t + \D^2 u = \g u \pm \D (|u|^{p-1}u) in \Omega \times \re_+, are considered
in a smooth bounded domain $\O \subset \ren$ with Navier-type boundary
conditions on $\p \O$, or $\O = \ren$, where $p>1$ and $\g$ are given real
parameters. The sign $``+"$ in the "diffusion term" on the right-hand side
means the stable case, while $``-"$ reflects the unstable (blow-up) one, with
the simplest, so called limit, canonical model for $\g=0$, (02) u_t + \D^2 u=
\pm \D(|u|^{p-1}u) \inA. The following three main problems are studied: (i) for
the unstable model (01), with the $- \D (|u|^{p-1}u)$, existence and
multiplicity of classic steady states in $\O \subset \ren$ and their global
behaviour for large $\g>0$; (ii) for the stable model (02), global existence of
smooth solutions $u(x,t)$ in $\ren \times \re_+$ for bounded initial data
$u_0(x)$ in the subcritical case $p \le p_{*}= 1 + \frac {4}{(N-2)_+}$; and
(iii) for the unstable model (02), a relation between finite time blow-up and
structure of regular and singular steady states in the supercritical range. In
particular, three distinct families of Type I and II blow-up patterns are
introduced in the unstable case.


title: Propagation of partial randomness

abstract:
  Let f be a computable function from finite sequences of 0's and 1's to real
numbers. We prove that strong f-randomness implies strong f-randomness relative
to a PA-degree. We also prove: if X is strongly f-random and Turing reducible
to Y where Y is Martin-L"of random relative to Z, then X is strongly f-random
relative to Z. In addition, we prove analogous propagation results for other
notions of partial randomness, including non-K-triviality and autocomplexity.
We prove that f-randomness relative to a PA-degree implies strong f-randomness,
hence f-randomness does not imply f-randomness relative to a PA-degree.


title: Using Lagrangian perturbation theory for precision cosmology

abstract:
  We explore the Lagrangian perturbation theory (LPT) at 1-loop order with
Gaussian initial conditions. We present an expansion method to approximately
compute the power spectrum in LPT. Our approximate solution has good
convergence in the series expansion and enables us to compute the power
spectrum in LPT accurately and quickly. Non-linear corrections in the
Lagrangian perturbation theory naturally satisfy the law of conservation of
mass because the relation between matter density and the displacement vector of
dark matter corresponds to the conservation of mass. By matching the 1-loop
solution in LPT to the 2-loop solution in standard perturbation theory, we
present an approximate solution of the power spectrum which has higher order
corrections than the 2-loop order in standard perturbation theory with the
conservation of mass satisfied. With this approximation, we can use LPT to
compute a non-linear power spectrum without any free parameters, and this
solution agrees with numerical simulations at $k=0.2$ $h{\rm Mpc}^{-1}$ and
$z=0.35$ to better than 2%.


title:
Effects of Dark Energy Perturbations on Cosmological Tests of General
  Relativity

abstract:
  Cosmological tests to distinguish between dark energy (DE) and modifications
to gravity are a promising route to obtain clues on the origin of cosmic
acceleration. We study here the robustness of these tests to the presence of DE
density, velocity, and anisotropic stress perturbations. We find that the
dispersion in the growth index parameter remains small enough to distinguish
between extreme cases of DE models and some commonly used modified gravity
models. The sign of the slope parameter for a redshift dependent growth index
was found to be inconsistent as an additional test in extreme cases of DE
models with perturbations. Next, we studied the effect of DE perturbations on
the modified growth (MG) parameters that enter the perturbed Einstein
equations. We find that while the dark energy perturbations affect the MG
parameters, the deviations remain smaller than those due to modified gravity
models. Additionally, the deviations due to DE perturbations with a non-zero
effective sound speed occur at scale ranges that are completely different than
those due to some modified gravity models such as the $f(R)$ models. In the
case of modified gravity models with zero anisotropic stress at late times, the
simultaneous determination of the effective dark energy equation of state and
the MG parameters can provide the distinction between these models and DE. The
growth index test was found to be the most robust to these perturbations. The
scale dependence of the MG parameters in some cases of modified gravity
constitute a clear-cut discriminant regardless of any DE perturbations. In
summary, we find that the currently proposed cosmological tests to distinguish
between DE and modified gravity are robust to DE perturbations even for extreme
cases. This is certainly the case even for DE models with equations of state of
DE that fall well outside of current cosmological constraints.


title: Wireless energy transfer between anisotropic metamaterials shells

abstract:
  The behavior of strongly coupled Radial Photonic Crystals shells is
investigated as a potential alternative to transfer electromagnetic energy
wirelessly. These sub-wavelength resonant microstructures, which are based on
anisotropic metamaterials, can produce efficient coupling phenomena due to
their high quality factor. A configuration of selected constitutive parameters
(permittivity and permeability) is analyzed in terms of its resonant
characteristics. The coupling to loss ratio between two coupled resonators is
calculated as a function of distance, the maximum (in excess of 300) is
obtained when the shells are separated by three times their radius. Under
practical conditions an 83% of maximum power transfer has been also estimated.


title: To parallelize or not to parallelize, bugs issue

abstract:
  Program correctness is one of the most difficult challenges in parallel
programming. Message Passing Interface MPI is widely used in writing parallel
applications. Since MPI is not a compiled language, the programmer will be
enfaced with several programming bugs.This paper presents the most common
programming bugs arise in MPI programs to help the programmer to compromise
between the advantage of parallelism and the extra effort needed to detect and
fix such bugs. An algebraic specification of an MPI-like programming language,
called Simple MPI (SMPI), to be used in writing MPI programs specification has
also been proposed. In addition, both nondeterminacy and deadlocks arise in
SMPI programs have been verified using Maud system.


title: Superintegrable systems on spaces of constant curvature

abstract:
  Construction and classification of 2D superintegrable systems (i.e. systems
admitting, in addition to two global integrals of motion guaranteeing the
Liouville integrability, the third global and independent one) defined on 2D
spaces of constant curvature and separable in the so called geodesic polar
coordinates are presented. The method proposed is applicable to any value of
curvature including the case of Euclidean plane, the 2-sphere and the
hyperbolic plane. The mathematic used is essentially "physical", in particular
it refers to the very elegant technique of action-angle variables and
perturbation theory so most of our mathematical formulas have a clear physical
meaning. The main result can be considered as a kind of generalization of the
Bertrand's theorem on 2D spaces of constant curvature and it covers most of
known separable and superintegrable models on such spaces (in particular, the
so-called Tremblay-Turbiner-Winternitz (TTW) and Post-Winternitz (PW) models
which have recently attracted some interest).

categories: math-ph math.MP nlin.SI physics.class-ph


title:
A step towards exploring the features of Gravidilaton sector in
  Randall-Sundrum scenario via lightest Kaluza-Klein graviton mass

abstract:
  In this paper we study the role of the 5D Gauss-Bonnet corrections and two
loop higher genus contribution to the gravity action in type IIB string theory
inspired low energy supergravity theory in the light of gravidilatonic
interactions on the lightest Kaluza-Klein graviton mass spectrum. From the
latest constraints on the lightest Kaluza-Klein graviton mass as obtained from
the ATLAS dilepton search in 7 TeV proton-proton collision, we have shown that
due to the presence of Gauss-Bonnet and string loop corrections, the warping
solution in an ${\bf AdS_{5}}$ bulk is quite distinct from Randall-Sundrum
scenario. We discuss the constraints on the model parameters to fit with
present ATLAS data.


title: To parallelize or not to parallelize, control and data flow issue

abstract:
  New trends towards multiple core processors imply using standard programming
models to develop efficient, reliable and portable programs for distributed
memory multiprocessors and workstation PC clusters. Message passing using MPI
is widely used to write efficient, reliable and portable applications. Control
and data flow analysis concepts, techniques and tools are needed to understand
and analyze MPI programs. If our point of interest is the program control and
data flow analysis, to decide to parallelize or not to parallelize our
applications, there is a question to be answered, " Can the existing concepts,
techniques and tools used to analyze sequential programs also be used to
analyze parallel ones written in MPI?". In this paper we'll try to answer this
question.


title:
On the Black Holes in alternative theories of gravity: The case of
  non-linear massive gravity

abstract:
  I derive general conditions in order to explain the origin of the Vainshtein
radius inside dRGT. The set of equations, which I have called "Vainshtein"
conditions are extremal conditions of the dynamical metric ($g_{\mu\nu}$)
containing all the degrees of freedom of the theory. The Vainshtein conditions
are able to explain the coincidence between the Vainshtein radius in dRGT and
the scale $r_0=\left(\frac{3}{2}r_s r_\Lambda^2\right)^{1/3}$, obtained
naturally from the Schwarzschild de-Sitter (S-dS) space inside General
Relativity (GR). In GR, this scale was interpreted as the maximum distance in
order to get bound orbits. The same scale corresponds to the static observer
position if we want to define the black hole temperature in an asymptotically
de-Sitter space. In dRGT, the scale marks a limit after which the extra degrees
of freedom of the theory become relevant.


title: Geometrical methods in mathematical physics

abstract:
  We give detailed exposition of modern differential geometry from global
coordinate independent point of view as well as local coordinate description
suited for actual computations. In introduction, we consider Euclidean spaces
and different structures on it; rotational, Lorentz, and Poincare groups;
special relativity. The main body of the manuscript includes manifolds, tensor
fields, differential forms, integration, Riemannian and Lorentzian metrics,
connection on vector and frame fiber bundles, affine geometry, Lie groups,
transformation groups, homotopy and fundamental group, coverings, principal and
associated fiber bundles, connections on fiber bundles, Killing vector fields,
geodesics and extremals, symplectic and Poisson manifolds, Clifford algebras,
principle of least action, canonical formalism for constrained systems.
Applications of differential geometry in quantum theory (adiabatic theorem,
Berry phase, Aharonov-Bohm effect), general relativity and geometric theory of
defects are described. We give introduction to general relativity and its
Hamiltonian formulation; describe scalar, spinor, electromagnetic and
Yang-Mills fields. Riemannian and Lorentzian surfaces with one Killing vector
field are discussed in detail, and their global structure is described using
conformal block method. We also classified all global vacuum solutions of the
Einstein equations, which have the form of warped product metrics of two
surfaces. The manuscript is not a textbook, and intended for efficient reader.


title: Variability of the High Velocity Outflow in the Quasar PDS 456

abstract:
  We present a comparison of two Suzaku X-ray observations of the nearby
(z=0.184), luminous ($L_{bol} \sim 10^{47}$ erg s$^{-1}$) type I quasar,
PDS456. A new 125ks Suzaku observation in 2011 caught the quasar during a
period of low X-ray flux and with a hard X-ray spectrum, in contrast to a
previous 190ks Suzaku observation in 2007 when the quasar appeared brighter and
had a steep ($\Gamma>2$) X-ray spectrum. The 2011 X-ray spectrum contains a
pronounced trough near 9\,keV in the quasar rest frame, which can be modeled
with blue-shifted iron K-shell absorption, most likely from the He and H-like
transitions of iron. The absorption trough is observed at a similar rest-frame
energy as in the earlier 2007 observation, which appears to confirm the
existence of a persistent high velocity wind in PDS 456, at an outflow velocity
of $0.25-0.30$c. The spectral variability between 2007 and 2011 can be
accounted for by variations in a partial covering absorber, increasing in
covering fraction from the brighter 2007 observation to the hard and faint 2011
observation. Overall the low flux 2011 observation can be explained if PDS 456
is observed at relatively low inclination angles through a Compton thick wind,
originating from the accretion disk, which significantly attenuates the X-ray
flux from the quasar.


title:
Collision of Shock Waves in Einstein-Maxwell Theory with a Cosmological
  Constant: A Special Solution

abstract:
  Post-collision space-times of the Cartesian product form M'xM'', where M' and
M'' are two-dimensional manifolds, are known with M' and M'' having constant
curvatures of equal and opposite sign (for the collision of electromagnetic
shock waves) or of the same sign (for the collision of gravitational shock
waves). We construct here a new explicit post-collision solution of the
Einstein-Maxwell vacuum field equations with a cosmological constant for which
M' has constant (nonzero) curvature and M'' has zero curvature.


title:
Towards the dynamical study of heavy-flavor quarks in the
  Quark-Gluon-Plasma

abstract:
  Within the aim of a dynamical study of on- and off-shell heavy quarks Q in
the quark gluon plasma (QGP) - as produced in relativistic nucleus-nucleus
collisions - we study the heavy quark collisional scattering on partons of the
QGP. The elastic cross sections $\sigma_{q,g-Q}$ are evaluated for perturbative
partons (massless on-shell particles) and for dynamical quasi-particles
(massive off-shell particles as described by the dynamical quasi-particles
model "DQPM") using the leading order Born diagrams. We demonstrate that the
finite width of the quasi-particles in the DQPM has little influence on the
cross sections $\sigma_{q,g-Q}$ except close to thresholds. We, furthermore,
calculate the heavy quark relaxation time as a function of temperature T within
the different approaches using these cross sections.


title:
Compression Limits for Random Vectors with Linearly Parameterized
  Second-Order Statistics

abstract:
  The class of complex random vectors whose covariance matrix is linearly
parameterized by a basis of Hermitian Toeplitz (HT) matrices is considered, and
the maximum compression ratios that preserve all second-order information are
derived --- the statistics of the uncompressed vector must be recoverable from
a set of linearly compressed observations. This kind of vectors arises
naturally when sampling wide-sense stationary random processes and features a
number of applications in signal and array processing.
  Explicit guidelines to design optimal and nearly optimal schemes operating
both in a periodic and non-periodic fashion are provided by considering two of
the most common linear compression schemes, which we classify as dense or
sparse. It is seen that the maximum compression ratios depend on the structure
of the HT subspace containing the covariance matrix of the uncompressed
observations. Compression patterns attaining these maximum ratios are found for
the case without structure as well as for the cases with circulant or banded
structure. Universal samplers are also proposed to compress unknown HT
subspaces.


title: Every action of a non-amenable group is the factor of a small action

abstract:
  It is well known that if $G$ is a countable amenable group and $G
\curvearrowright (Y, \nu)$ factors onto $G \curvearrowright (X, \mu)$, then the
entropy of the first action must be greater than or equal to the entropy of the
second action. In particular, if $G \curvearrowright (X, \mu)$ has infinite
entropy, then the action $G \curvearrowright (Y, \nu)$ does not admit any
finite generating partition. On the other hand, we prove that if $G$ is a
countable non-amenable group then there exists a finite integer $n$ with the
following property: for every probability-measure-preserving action $G
\curvearrowright (X, \mu)$ there is a $G$-invariant probability measure $\nu$
on $n^G$ such that $G \curvearrowright (n^G, \nu)$ factors onto $G
\curvearrowright (X, \mu)$. For many non-amenable groups, $n$ can be chosen to
be $4$ or smaller. We also obtain a similar result with respect to continuous
actions on compact spaces and continuous factor maps.


title:
Alignment of vorticity and rods with Lagrangian fluid stretching in
  turbulence

abstract:
  Stretching in continuum mechanics is naturally described using the
Cauchy-Green strain tensors. These tensors quantify the Lagrangian stretching
experienced by a material element, and provide a powerful way to study
processes in turbulent fluid flows that involve stretching such as vortex
stretching and alignment of anisotropic particles. Analyzing data from a
simulation of isotropic turbulence, we observe preferential alignment between
anisotropic particles and vorticity. We show that this alignment arises because
both of these quantities independently tend to align with the strongest
Lagrangian stretching direction, as defined by the maximum eigenvector of the
left Cauchy-Green strain tensor. In particular, anisotropic particles approach
almost perfect alignment with the strongest stretching direction. The alignment
of vorticity with stretching is weaker, but still much stronger than previously
observed alignment of vorticity with the eigenvectors of the Eulerian strain
rate tensor. The alignment of strong vorticity is almost the same as that of
rods that have experienced the same stretching.


title:
Charged Higgs contribution to $\bar{B}_s \rightarrow \phi \pi^0 $ and
  $\bar{B}_s \rightarrow \phi \rho^0 $

abstract:
  We study the decay modes $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi
\rho^0$ within the frameworks of two-Higgs doublet models type-II and typ-III.
We adopt in our study Soft Collinear Effective Theory as a framework for the
calculation of the amplitudes. We derive the contributions of the charged Higgs
mediation to the weak effective Hamiltonian governing the decay processes in
both models. Moreover we analyze the effect of the charged Higgs mediation on
the Wilson coefficients of the electrowek penguins and on the branching ratios
of $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi \rho^0$ decays. We show
that wthin two-Higgs doublet models type-II and type-III the Wilson
coefficients corresponding to the electroweak penguins can be enhanced due to
the contributions from the charged Higgs mediation leading into enhancement in
the branching ratios of $ \bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi
\rho^0 $ decays. We find that, within two-Higgs doublet models type-II, the
enhancement in the branching ratio of $\bar{B}_s\to \phi \pi^0$ can not exceed
$18\%$ with respect to the SM predictions. For the branching ratio of
$\bar{B}_s\to \phi \rho^0$, we find that the charged Higgs contribution in this
case is small where the branching ratio of $\bar{B}_s\to \phi \rho^0$ can be
enhanced or reduced by about $4\% $ with respect to the SM predictions. For the
case of the two-Higgs doublet models type-III we show that the branching ratio
of $\bar{B}_s\to \phi \pi^0$ can be enhanced by about a factor $2$ of its value
within two-Higgs doublet models type-II. However no sizable enhancement with
respect to the SM predictions can be obtained for both $\bar{B}_s\to \phi
\pi^0$ and $\bar{B}_s\to \phi \rho^0$ decays.


title:
A new closed-form model for isotropic elastic sphere including new
  solutions for the free vibrations problem

abstract:
  We develop a new closed-form model for the dynamics of an elastic and
isotropic sphere and use it to derive new closed-form resonant frequencies.


title: Cooling by heating in a mesoscopic two-state device

abstract:
  We reanalyse the work of Cleuren et al., Phys. Rev. Lett. 109, 248902 (2012),
in the light of Jiang et al. Phys. Rev. B 85, 075412 (2012). The condition for
cooling enforces its rate to be exponentially small at low temperatures. Thus,
the difficulty with the "dynamic version of the third law" found by Levy et
al., Phys. Rev. Lett. 109, 248901 (2012) and Allahverdyan et al., Phys. Rev.
Lett. 109, 248903 (2012) is resolved.


title: Rational maps from punctual Hilbert schemes of K3 surfaces

abstract:
  The purpose of this short note is to study dominant rational maps from
punctual Hilbert schemes of length $k>1$ of projective K3 surfaces $S$
containing infinitely many rational curves. Precisely, we prove that their
image is necessarily rationally connected if this rational map is not
generically finite. As an application, we simplify the proof of C. Voisin's of
the fact that symplectic involutions of any projective K3 surface $S$ act
trivially on $\mathrm{CH}_0(S)$.


title: Nearly Starobinsky inflation from modified gravity

abstract:
  We study inflation induced by (power-low) scalar curvature corrections to
General Relativity. The class of inflationary scalar potentials
$V(\sigma)\sim\exp[n\,\sigma]$, $n$ general parameter, is investigated in the
Einsein frame and the corresponding actions in the Jordan frame are derived. We
found the conditions for which these potentials are able to reproduce viable
inflation according with the last cosmological data and lead to large scalar
curvature corrections which emerge only at a mass scale larger than the Planck
mass. Cosmological constant may appear or be set equal to zero in the Jordan
frame action without changing the behaviour of the model during inflation.
Moreover, polynomial corrections to General Relativity are analyzed in detail.
When de Sitter space-time emerges as an exact solution of the models, it is
necessary to use perturbative equations in the Jordan framework to study their
dynamics during the inflation. In this case, we demonstrate that the Ricci
scalar decreases after a correct amount of inflation, making the models
consistent with the observable evolution of the universe.


title: Is the world made of loops?

abstract:
  I see no good reason to prefer (any version I know of) the `holonomy
interpretation' to the `potential interpretation' of the Aharonov-Bohm effect.
Everyone agrees that the inverse image $[A]=[A+d\lambda]_{\lambda}=d^{-1}F$ of
the electromagnetic field $F$ is a class, full of individuals; and that the
circulation $\small{\textsf{C}}$ of the electromagnetic potential $A$ around a
loop $\sigma_0$ encircling the solenoid is common to the whole class $[A]$, and
to the homotopy class or \emph{hoop} $[\sigma_0]$. If picking individuals out
of classes is the problem, picking an individual potential out of $[A]$ should
be no worse than picking an individual loop out of $[\sigma_0]$. The
individuals of $[A]$ can moreover be transcended---punctually, without
integration around loops---by an appropriate version of the electromagnetic
connection.


title:
A Fast Algorithm for the Construction of Integrity Bases Associated to
  Symmetry-Adapted Polynomial Representations. Application to Tetrahedral XY4
  Molecules

abstract:
  Invariant theory provides more efficient tools, such as Molien generating
functions and integrity bases, than basic group theory, that relies on
projector techniques for the construction of symmetry--adapted polynomials in
the symmetry coordinates of a molecular system, because it is based on a finer
description of the mathematical structure of the latter. The present article
extends its use to the construction of polynomial bases which span possibly,
non--totally symmetric irreducible representations of a molecular symmetry
group. Electric or magnetic observables can carry such irreducible
representations, a common example is given by the electric dipole moment
surface. The elementary generating functions and their corresponding integrity
bases, where both the initial and the final representations are irreducible,
are the building blocks of the algorithm presented in this article, which is
faster than algorithms based on projection operators only. The generating
functions for the full initial representation of interest are built recursively
from the elementary generating functions. Integrity bases which can be used to
generate in the most economical way symmetry--adapted polynomial bases are
constructed alongside in the same fashion. The method is illustrated in detail
on XY4 type of molecules. Explicit integrity bases for all five possible final
irreducible representations of the tetrahedral group have been calculated and
are given in the supplemental material associated with this paper.


title:
Hexagonal flow v_6 as a superposition of elliptic v_2 and triangular v_3
  flows

abstract:
  Partial contributions of elliptic v_2 and triangular v_3 flows to the
hexagonal v_6 flow are studied within the HYDJET++ model for Pb+Pb collisions
at sqrt{s}=2.76 TeV. Scaling of the ratio v_6^{1/6}{Psi_2} / v_2^{1/2}{Psi_2}
in the elliptic flow plane, Psi_2, is predicted in the range 1 < p_T < 4 GeV/c
for semicentral and semiperipheral collisions. Jets increase this ratio by
about 10% and also cause its rise at p_T > 3.5 GeV/c. The part of v_6 coming
from v_2 is instantly increasing as the reaction becomes more peripheral,
whereas the contribution of v_3 to v_6 drops. This behavior explains the
experimentally observed increase of correlations between second and sixth
harmonics and decrease of correlations between third and sixth harmonics with
rising impact parameter $b$. Our study favors the idea that basic features of
the hexagonal flow can be understood in terms of the interplay of elliptic and
triangular flows.


title:
On reducing inconsistency of pairwise comparison matrices below an
  acceptance threshold

abstract:
  A recent work of the authors on the analysis of pairwise comparison matrices
that can be made consistent by the modification of a few elements is continued
and extended. Inconsistency indices are defined for indicating the overall
quality of a pairwise comparison matrix. It is expected that serious
contradictions in the matrix imply high inconsistency and vice versa. However,
in the 35-year history of the applications of pairwise comparison matrices,
only one of the indices, namely CR proposed by Saaty, has been associated to a
general level of acceptance, by the well known ten percent rule. In the paper,
we consider a wide class of inconsistency indices, including CR, CM proposed by
Koczkodaj and Duszak and CI by Pel\'aez and Lamata. Assume that a threshold of
acceptable inconsistency is given (for CR it can be 0.1). The aim is to find
the minimal number of matrix elements, the appropriate modification of which
makes the matrix acceptable. On the other hand, given the maximal number of
modifiable matrix elements, the aim is to find the minimal level of
inconsistency that can be achieved. In both cases the solution is derived from
a nonlinear mixed-integer optimization problem. Results are applicable in
decision support systems that allow real time interaction with the decision
maker in order to review pairwise comparison matrices.


title:
Polarization-dependent light extinction in ensembles of polydisperse,
  vertical semiconductor nanowires: A Mie scattering effective medium

abstract:
  We present an experimental and theoretical study of the angle- and
polarization-dependent light extinction in random arrays of polydisperse
semiconductor nanowires epitaxially grown on substrates. The specular
reflectance is described by averaging the scattering properties of individual
nanowires obtained from Lorenz-Mie theory over the diameter distribution. The
complex effective refractive index describing the propagation and attenuation
of the coherent beam scattered in forward direction is determined in the
independent scattering approximation and used to calculate the angle- and
polarization-dependent reflectance. Our measurements demonstrate the highly
anisotropic scattering in ensembles of aligned nanowires.


title: Mondshein Sequences (a.k.a. (2,1)-Orders)

abstract:
  Canonical orderings [STOC'88, FOCS'92] have been used as a key tool in graph
drawing, graph encoding and visibility representations for the last decades. We
study a far-reaching generalization of canonical orderings to non-planar graphs
that was published by Lee Mondshein in a PhD-thesis at M.I.T. as early as 1971.
  Mondshein proposed to order the vertices of a graph in a sequence such that,
for any i, the vertices from 1 to i induce essentially a 2-connected graph
while the remaining vertices from i+1 to n induce a connected graph.
Mondshein's sequence generalizes canonical orderings and became later and
independently known under the name non-separating ear decomposition.
Surprisingly, this fundamental link between canonical orderings and
non-separating ear decomposition has not been established before. Currently,
the fastest known algorithm for computing a Mondshein sequence achieves a
running time of O(nm); the main open problem in Mondshein's and follow-up work
is to improve this running time to subquadratic time.
  After putting Mondshein's work into context, we present an algorithm that
computes a Mondshein sequence in optimal time and space O(m). This improves the
previous best running time by a factor of n. We illustrate the impact of this
result by deducing linear-time algorithms for five other problems, for four out
of which the previous best running times have been quadratic. In particular, we
show how to - compute three independent spanning trees of a 3-connected graph
in time O(m), - improve the preprocessing time from O(n^2) to O(m) for a data
structure reporting 3 internally disjoint paths between any given vertex pair,
- derive a very simple O(n)-time planarity test once a Mondshein sequence has
been computed, - compute a nested family of contractible subgraphs of
3-connected graphs in time O(m), - compute a 3-partition in time O(m).


title:
Mapping the directional emission of quasi-two-dimensional photonic
  crystals of semiconductor nanowires using Fourier microscopy

abstract:
  Controlling the dispersion and directionality of the emission of nanosources
is one of the major goals of nanophotonics research. This control will allow
the development of highly efficient nanosources even at the single photon
level. One of the ways to achieve this goal is to couple the emission to Bloch
modes of periodic structures. Here, we present the first measurements of the
directional emission from nanowire photonic crystals by using Fourier
microscopy. With this technique we efficiently collect and resolve the
directional emission of nanowires within the numerical aperture of a microscope
objective. The light emission from a heterostructure grown in each nanowire is
governed by the photonic (Bloch) modes of the photonic crystal. We also
demonstrate that the directionality of the emission can be easily controlled by
infiltrating the photonic crystal with a high refractive index liquid. This
work opens new possibilities for the control of the emission of sources in
nanowires.


title: On the Magnetosphere of an Accelerated Pulsar

abstract:
  We report on a remarkable class of exact solutions to force-free
electrodynamics that has four-current along the light cones of an arbitrary
timelike worldline in flat spacetime. No symmetry is assumed, and the solutions
are given in terms of a free function of three variables. The field
configuration should describe the outer magnetosphere of a pulsar moving on the
worldline. The power radiated is the sum of an acceleration (Larmor-type) term
and a pulsar-type term.


title: Sequential dependencies between trials in free choice tasks

abstract:
  In two previous experiments we investigated the neural precursors of
subjects' "free" choices for one of two options (pressing one of two buttons,
and choosing between adding and subtracting numbers). In these experiments the
distribution of sequence lengths was taken as an approximate indicator of the
randomness (or lack of sequential dependency) of the choice sequences. However,
this method is limited in its ability to reveal sequential dependencies. Here
we present a more detailed individual-subject analysis and conclude that
despite of the presence of significant sequential dependencies the subjects'
behavior still approximates randomness, as measured by an entropy rate (on
pooled data) of 0.940 bit / trial and 0.965 bit / trial in the two experiments.
We also provide the raw single-subject behavioral data.


title: Mertens' theorem and prime number theorem for Selberg class

abstract:
  In 1874, Mertens proved the approximate formula for partial Euler product for
Riemann zeta function at $s=1$, which is called Mertens' theorem. In this
paper, we generalize Mertens' theorem for Selberg class and show the prime
number theorem for Selberg class.


title: Lectures on Holographic Space Time

abstract:
  Summary of three talks on the Holographic Space Time models of early universe
cosmology, particle physics, and the asymptotically de Sitter final state of
our universe.


title: On the synthesis of Quantum Hall Array Resistance Standards

abstract:
  Quantum Hall effect (QHE) is the basis of modern resistance metrology. In
Quantum Hall Array Resistance Standards (QHARS), several individual QHE
elements, each one having the same QHE resistance (typically half of the von
Klitzing constant), are arranged in networks that realize resistance values
close to decadic values (such as 1 kiloohm or 100 kiloohm), of direct interest
for dissemination. The same decadic value can be approximated with different
grades of precision, and even for the same approximation several networks of
QHE elements can be conceived. The paper investigates the design of QHARS
networks by giving methods to find a proper approximation of the resistance of
interest, and to design the corresponding network with a small number of
elements. Results for several decadic cases are given.


title: Computations with modified diagonals

abstract:
  Beauville and Voisin proved that the third modified diagonal of a complex K3
surface X represents a torsion class in the Chow group of X^3. Motivated by
this result and by conjectures of Beauville and Voisin on the Chow ring of
hyperkaehler varieties we prove some results on modified diagonals of
projective varieties and we formulate a conjecture.


title: Observation of large-scale multi-agent based simulations

abstract:
  The computational cost of large-scale multi-agent based simulations (MABS)
can be extremely important, especially if simulations have to be monitored for
validation purposes. In this paper, two methods, based on self-observation and
statistical survey theory, are introduced in order to optimize the computation
of observations in MABS. An empirical comparison of the computational cost of
these methods is performed on a toy problem.