title:
Dynamic screening and energy loss of antiprotons colliding with excited
  Al clusters

abstract:
  We use time-dependent density functional theory to calculate the energy loss
of an antiproton colliding with a small Al cluster previously excited. The
velocity of the antiproton is such that non-linear effects in the electronic
response of the Al cluster are relevant. We obtain that an antiproton
penetrating an excited cluster transfers less energy to the cluster than an
antiproton penetrating a ground state cluster. We quantify this difference and
analyze it in terms of the cluster excitation spectrum.


title: LUNASKA neutrino search with the Parkes and ATCA telescopes

abstract:
  The Moon is used as a target volume for ultra-high energy neutrino searches
with terrestrial radio telescopes. The LUNASKA project has conducted
observations with the Parkes and ATCA telescopes; and, most recently, with both
of them in combination. We present an analysis of the data obtained from these
searches, including validation and calibration results for the Parkes-ATCA
experiment, as well as a summary of prospects for future observations.


title:
SINR-based k-coverage probability in cellular networks with arbitrary
  shadowing

abstract:
  We give numerically tractable, explicit integral expressions for the
distribution of the signal-to-interference-and-noise-ratio (SINR) experienced
by a typical user in the down-link channel from the k-th strongest base
stations of a cellular network modelled by Poisson point process on the plane.
Our signal propagation-loss model comprises of a power-law path-loss function
with arbitrarily distributed shadowing, independent across all base stations,
with and without Rayleigh fading. Our results are valid in the whole domain of
SINR, in particular for SINR<1, where one observes multiple coverage. In this
latter aspect our paper complements previous studies reported in [Dhillon et
al. JSAC 2012].


title: Conformal dimension and canonical splittings of hyperbolic groups

abstract:
  We prove a general criterion for a metric space to have conformal dimension
one. The conditions are stated in terms of the existence of enough local cut
points in the space. We then apply this criterion to the boundaries of
hyperbolic groups and show an interesting relationship between conformal
dimension and some canonical splittings of the group.


title:
Inequalities and bounds for the eigenvalues of the sub-Laplacian on a
  strictly pseudoconvex CR manifold

abstract:
  We establish inequalities for the eigenvalues of the sub-Laplace operator
associated with a pseudo-Hermitian structure on a strictly pseudoconvex CR
manifold. Our inequalities extend those obtained by Niu and Zhang
\cite{NiuZhang} for the Dirichlet eigenvalues of the sub-Laplacian on a bounded
domain in the Heisenberg group and are in the spirit of the well known
Payne-P\'{o}lya-Weinberger and Yang universal inequalities.


title:
Bayesian estimation for a parametric Markov Renewal model applied to
  seismic data

abstract:
  This paper presents a complete methodology for Bayesian inference on a
semi-Markov process, from the elicitation of the prior distribution, to the
computation of posterior summaries, including a guidance for its JAGS
implementation. The holding times (conditional on the transition between two
given states) are assumed to be Weibull-distributed. We examine the elicitation
of the joint prior density of the shape and scale parameters of the Weibull
distributions, deriving a specific class of priors in a natural way, along with
a method for the determination of hyperparameters based on ``learning data''
and moment existence conditions. This framework is applied to data of
earthquakes of three types of severity (low, medium and high size) that
occurred in the central Northern Apennines in Italy and collected by the
\cite{CPTI04} catalogue. Assumptions on two types of energy accumulation and
release mechanisms are evaluated.


title: Non-congruence of homology Veech groups in genus two

abstract:
  We study the action of the Veech group of square-tiled surfaces of genus two
on homology. This action defines the homology Veech group which is a subgroup
of $\textrm{SL}_2(\mathcal{O}_D)$ where $\mathcal{O}_D$ is a quadratic order of
square discriminant. Extending a result of Weitze-Schmith\"usen we show that
also the homology Veech group is a totally non-congruence subgroup with
exceptions stemming only from the prime ideals lying above 2. While
Weitze-Schmith\"usen's result for Veech groups is asymmetric with respect to
the spin structure our use of the homology Veech group yields a completely
symmetric picture.


title: A new proof of the Lie-Trotter-Kato formula in Hadamard spaces

abstract:
  The Lie-Trotter-Kato product formula has been recently extended into Hadamard
spaces by [Stojkovic, Adv. Calc. Var., 2012]. The aim of our short note is to
give a simpler proof relying upon weak convergence instead of an ultrapower
technique.


title:
Evolution of the multiband RKKY interaction: Application to iron
  pnictides and chalcogenides

abstract:
  The indirect RKKY interaction in iron pnictide and chalcogenide metals is
calculated for a simplified four bands Fermi surface (FS) model. We investigate
the specific multi-band features and show that distinct length scales of the
RKKY oscillations appear. For the regular lattice of the local moments, the
generalized RKKY interaction is defined in momentum space. We consider its
momentum dependence in paramagnetic and spin density wave (SDW) phases, discuss
its implications for the possible type of magnetic order and compare it to the
results obtained from more realistic tight-binding type Fermi surface model.
Our finding can give important clues on the magnetic ordering of the 4f- iron
based superconductors.


title: Topological strata of weighted complex networks

abstract:
  The statistical mechanical approach to complex networks is the dominant
paradigm in describing natural and societal complex systems. The study of
network properties, and their implications on dynamical processes, mostly focus
on locally defined quantities of nodes and edges, such as node degrees, edge
weights and --more recently-- correlations between neighboring nodes. However,
statistical methods quickly become cumbersome when dealing with many-body
properties and do not capture the precise mesoscopic structure of complex
networks. Here we introduce a novel method, based on persistent homology, to
detect particular non-local structures, akin to weighted holes within the
link-weight network fabric, which are invisible to existing methods. Their
properties divide weighted networks in two broad classes: one is characterized
by small hierarchically nested holes, while the second displays larger and
longer living inhomogeneities. These classes cannot be reduced to known local
or quasilocal network properties, because of the intrinsic non-locality of
homological properties, and thus yield a new classification built on high order
coordination patterns. Our results show that topology can provide novel
insights relevant for many-body interactions in social and spatial networks.
Moreover, this new method creates the first bridge between network theory and
algebraic topology, which will allow to import the toolset of algebraic methods
to complex systems.


title: Radiation reaction in strong field QED

abstract:
  We derive radiation reaction from QED in a strong background field. We
identify, in general, the diagrams and processes contributing to recoil effects
in the average momentum of a scattered electron, using perturbation theory in
the Furry picture: we work to lowest nontrivial order in the electromagnetic
coupling alpha. For the explicit example of scattering in a plane wave
background, we compare QED with classical electrodynamics in the limit h-bar
goes to zero, finding agreement with the Lorentz-Abraham-Dirac and
Landau-Lifshitz equations, and with Larmor's formula. The first quantum
corrections are also presented.


title:
Symmetric logarithmic derivative for general n-level systems and the
  quantum Fisher information tensor for three-level systems

abstract:
  Within a geometrical context, we derive an explicit formula for the
computation of the symmetric logarithmic derivative for arbitrarily mixed
quantum systems, provided that the structure constants of the associated
unitary Lie algebra are known. To give examples of this procedure, we first
recover the known formulae for two-level mixed and three-level pure state
systems and then apply it to the novel case of U(3), that is for arbitrarily
mixed three-level systems (q-trits). Exploiting the latter result, we finally
calculate an expression for the Fisher tensor for a q-trit considering also all
possible degenerate subcases.


title:
Magnetic Impurity Affected by Spin-Orbit Coupling: Behavior near a
  Topological Phase Transition

abstract:
  We investigate the effect of spin-orbit coupling on the behavior of magnetic
impurity at the edge of a zigzag graphene ribbon by means of quantum Monte
Carlo simulations. A peculiar interplay of Kane-Mele type spin-orbit and
impurity-host coupling is found to affect local properties such as the impurity
magnetic moment and spectral densities. The special helical nature of the
topological insulator on the edge is found to affect nonlocal quantities, such
as the two-particle and spin-spin correlation functions linking electrons on
the impurity with those in the conduction band.


title: A variational Approach to complex Hessian equations in $\mathbb{C}^n$

abstract:
  Let $\Omega$ be a $m$-hyperconvex domain of $\mathbb{C}^n$ and $\beta$ be the
standard K\"{a}hler form in $\mathbb{C}^n$. We introduce finite energy classes
of $m$-subharmonic functions of Cegrell type, $\mathcal{E}_m^p, p>0$ and
$\mathcal{F}_m$. Using a variational method we show that the degenerate complex
Hessian equation $(dd^c\varphi)^m\wedge \beta^{n-m}=\mu$ has a unique solution
in $\mathcal{E}_m^1$ if and only if every function in $\mathcal{E}_m^1$ is
integrable with respect to $\mu$. If $\mu$ has finite total mass and does not
charge $m$-polar sets, then the equation has a unique solution in
$\mathcal{F}_m$.


title:
Microcavity effects on the generation, fluorescence, and diffusion of
  excitons in organic solar cells

abstract:
  We compute the short-circuit diffusion current of excitons in an organic
solar cell, with special emphasis on fluorescence losses. The exciton diffusion
length is not uniform but varies with its position within the device, even with
moderate fluorescence quantum efficiency. With large quantum efficiencies, the
rate of fluorescence can be strongly reduced with proper choices of the
geometrical and dielectric parameters. In this way, the diffusion length can be
increased and the device performance significantly improved.

categories: physics.optics cond-mat.mes-hall cond-mat.mtrl-sci physics.chem-ph


title: Neutrino searches with the IceCube telescope

abstract:
  The IceCube Neutrino Observatory is an array of 5,160 photomultipliers (PMTs)
deployed on 86 strings at 1.5-2.5 km depth within the ice at the South Pole.
The main goal of the IceCube experiment is the detection of an astrophysical
neutrino signal. In this contribution we present the results of the point
source analysis on the data taken from April 2008 to May 2011, when three
detector configurations were operated: the 40-string configuration (IC-40), the
59-string configuration (IC-59) and the 79-string configuration (IC-79). No
significant excess indicative of point sources of neutrinos has been found, and
we present upper limits for an $E^{-2}$ muon neutrino flux for a list of
candidate sources. For the first time these limits start to reach $10^{-12}$
TeV$^{-1}$ cm$^{-2}$ s$^{-1}$ in some parts of the sky.


title:
2-Dimensional Combinatorial Calabi Flow in Hyperbolic Background
  Geometry

abstract:
  For triangulated surfaces locally embedded in the standard hyperbolic space,
we introduce combinatorial Calabi flow as the negative gradient flow of
combinatorial Calabi energy. We prove that the flow produces solutions which
converge to ZCCP-metric (zero curvature circle packing metric) if the initial
energy is small enough. Assuming the curvature has a uniform upper bound less
than $2\pi$, we prove that combinatorial Calabi flow exists for all time.
Moreover, it converges to ZCCP-metric if and only if ZCCP-metric exists.


title:
Dynamic structural and topological phase transitions on the Warsaw Stock
  Exchange: A phenomenological approach

abstract:
  We study the crash dynamics of the Warsaw Stock Exchange (WSE) by using the
Minimal Spanning Tree (MST) networks. We find the transition of the complex
network during its evolution from a (hierarchical) power law MST network,
representing the stable state of WSE before the recent worldwide financial
crash, to a superstar-like (or superhub) MST network of the market decorated by
a hierarchy of trees (being, perhaps, an unstable, intermediate market state).
Subsequently, we observed a transition from this complex tree to the topology
of the (hierarchical) power law MST network decorated by several star-like
trees or hubs. This structure and topology represent, perhaps, the WSE after
the worldwide financial crash, and could be considered to be an aftershock. Our
results can serve as an empirical foundation for a future theory of dynamic
structural and topological phase transitions on financial markets.


title:
Evolution of PAHs in photodissociation regions: Hydrogenation and charge
  states

abstract:
  Various studies have emphasized variations of the charge state and
composition of the interstellar polycyclic aromatic hydrocarbon (PAH)
population in photodissociation regions (PDRs). We aim to model the spatial
evolution of the charge and hydrogenation states of PAHs in PDRs. We focus on
the specific case of the north-west (NW) PDR of NGC 7023 and also discuss the
case of the diffuse interstellar medium (ISM). The physical conditions in NGC
7023 NW are modelled using a state-of-the-art PDR code. We then use a new PAH
chemical evolution model that includes recent experimental data on PAHs and
describes multiphoton events. We consider a family of compact PAHs bearing up
to 96 carbon atoms. The calculated ionization ratio is in good agreement with
observations in NGC 7023 NW. Within the PDR, PAHs evolve into three major
populations: medium-sized PAHs (50<Nc<90) are normally hydrogenated, larger
PAHs (Nc>90) can be superhydrogenated, and smaller species (Nc<50) are fully
dehydrogenated. In the cavity, where the fullerene C60 was recently detected,
all the studied PAHs are found to be quickly fully dehydrogenated. PAH chemical
evolution exhibits a complex non-linear behaviour as a function of the UV
radiation field because of multiphoton events. Steady state for hydrogenation
is reached on timescales ranging from less than a year for small PAHs, up to
10000 years for large PAHs at Av=1. We identified critical reactions that need
more studies. Our new model allows us to rationalize the observational
constraints without any fitting parameter. PAHs smaller than 50 carbon atoms
are not expected to survive in the NGC 7023 NW PDR. A similar conclusion is
obtained for the diffuse ISM. Carbon clusters turn out to be end products of
PAH photodissociation, and the evolution of these clusters needs to be
investigated further to evaluate their impact on the chemical and physical
evolution of PDRs.


title: On Harmonic Measure of the Whole Plane Levy-Loewner Evolution

abstract:
  Levy-Loewner evolution (LLE) is a generalization of the Schramm-Loewner
evolution (SLE) where the branching is possible in a course of growth process.
We consider a class of radial Levy-Loewner evolutions for which sets of points
of the average means beta-spectrum can be found exactly. In this paper we show
how to overcome difficulties arised in previous works on multi-fractal analysis
of SLE/LLE.

categories: math-ph cond-mat.stat-mech math.CV math.MP math.PR


title: On Multiple Pattern Avoiding Set Partitions

abstract:
  We study classes of set partitions determined by the avoidance of multiple
patterns, applying a natural notion of partition containment that has been
introduced by Sagan. We say that two sets S and T of patterns are equivalent if
for each n, the number of partitions of size n avoiding all the members of S is
the same as the number of those that avoid all the members of T.
  Our goal is to classify the equivalence classes among two-element pattern
sets of several general types. First, we focus on pairs of patterns
{\sigma,\tau}, where \sigma\ is a pattern of size three with at least two
distinct symbols and \tau\ is an arbitrary pattern of size k that avoids
\sigma. We show that pattern-pairs of this type determine a small number of
equivalence classes; in particular, the classes have on average exponential
size in k. We provide a (sub-exponential) upper bound for the number of
equivalence classes, and provide an explicit formula for the generating
function of all such avoidance classes, showing that in all cases this
generating function is rational.
  Next, we study partitions avoiding a pair of patterns of the form
{1212,\tau}, where \tau\ is an arbitrary pattern. Note that partitions avoiding
1212 are exactly the non-crossing partitions. We provide several general
equivalence criteria for pattern pairs of this type, and show that these
criteria account for all the equivalences observed when \tau\ has size at most
six.
  In the last part of the paper, we perform a full classification of the
equivalence classes of all the pairs {\sigma,\tau}, where \sigma\ and \tau\
have size four.


title: Zero noise limits using local times

abstract:
  We consider a well-known family of SDEs with irregular drifts and the
correspondent zero noise limits. Using (mollified) local times, we show which
trajectories are selected. The approach is completely probabilistic and relies
on elementary stochastic calculus only.


title: Poisson-Newton formulas and Dirichlet series

abstract:
  We prove that a Poisson-Newton formula, in a broad sense, is associated to
each Dirichlet series with a meromorphic extension to the whole complex plane.
These formulas simultaneously generalize the classical Poisson formula and
Newton formulas for Newton sums. Classical Poisson formulas in Fourier
analysis, classical summation formulas as Euler-McLaurin or Abel-Plana
formulas, explicit formulas in number theory and Selberg trace formulas in
Riemannian geometry appear as special cases of our general Poisson-Newton
formula. We also associate to finite order meromorphic functions general
Poisson-Newton formulas that yield many classical integral formulas.


title:
Secrecy in the 2-User Symmetric Deterministic Interference Channel with
  Transmitter Cooperation

abstract:
  This work presents novel achievable schemes for the 2-user symmetric linear
deterministic interference channel with limited-rate transmitter cooperation
and perfect secrecy constraints at the receivers. The proposed achievable
scheme consists of a combination of interference cancelation, relaying of the
other user's data bits, time sharing, and transmission of random bits,
depending on the rate of the cooperative link and the relative strengths of the
signal and the interference. The results show, for example, that the proposed
scheme achieves the same rate as the capacity without the secrecy constraints,
in the initial part of the weak interference regime. Also, sharing random bits
through the cooperative link can achieve a higher secrecy rate compared to
sharing data bits, in the very high interference regime. The results highlight
the importance of limited transmitter cooperation in facilitating secure
communications over 2-user interference channels.


title: Group actions on metric spaces: fixed points and free subgroups

abstract:
  We look at group actions on metric spaces, particularly at group actions on
geodesic hyperbolic spaces. We classify the types of automorphisms on these
spaces and prove several results about the density of the hyperbolic limit set
of the group in the whole limit set of the group. In the case of graphs, our
theorems hold also when the graphs are not hyperbolic.


title: Lie group symmetries for first order ODEs

abstract:
  This paper is centred on solving differential equations by symmetry groups
for first order ODEs and is in response to Starrett (2007). It also explores
the possibility of averting the assumptions by Olver (2000) that, in practice
finding the solutions of the linearized symmetry condition is usually a much
more difficult problem than solving the original ODE but, by inspired guesswork
or geometric intuition, it is possible to ascertain a particular solution of
the linearized symmetry condition. In addition, there is the verification of
the connection between prolongation and the linearized symmetry condition as
used in solving first order ODEs.


title:
Associated photon and heavy quark production at high energy within
  k_T-factorization

abstract:
  In the framework of the k_T-factorization approach, the production of prompt
photons in association with a heavy (charm or beauty) quarks at high energies
is studied. The consideration is based on the O(\alpha \alpha_s^2) off-shell
amplitudes of gluon-gluon fusion and quark-(anti)quark interaction
subprocesses. The unintegrated parton densities in a proton are determined
using the Kimber-Martin-Ryskin prescription. Our numerical predictions are
compared with the D0 and CDF experimental data. Also we extend our results to
LHC energies.


title: Bihomogeneous forms in many variables

abstract:
  We count integer points on bihomogeneous varieties using the Hardy-Littlewood
method. The main novelty lies in using the structure of bihomogeneous equations
to obtain asymptotics in generically fewer variables than would be necessary in
using the standard approach for homogeneous varieties. Also, we consider
counting functions where not all the variables have to lie in intervals of the
same size, which arises as a natural question in the setting of bihomogeneous
varieties.


title:
Lagrange mesh and exact diagonalization for numerical study of
  semiconductor quantum dot systems with application in singlet-triplet qubits

abstract:
  We present a highly flexible computational scheme for studying correlated
electrons confined by an arbitrary external potential in two-dimensional
semiconductor quantum dots. The method starts by a Lagrange mesh calculation
for the single-particle states, followed by the calculation of the Coulomb
interaction matrix elements between these, and combining both in the exact
diagonalization of the many-body Hamiltonian. We apply the method in simulation
of double quantum dot singlet-triplet qubits. We simulate the full quantum
control and dynamics of one singlet-triplet qubit. We also use our method to
provide an exact diagonalization based first-principles model for studying two
singlet-triplet qubits and their capacitative coupling via the long-distance
Coulomb interaction.


title:
Anisotropic shear melting and recrystallization of a two-dimensional
  complex (dusty) plasma

abstract:
  A two-dimensional plasma crystal was melted by suddenly applying localized
shear stress. A stripe of particles in the crystal was pushed by the radiation
pressure force of a laser beam. We found that the response of the plasma
crystal to stress and the eventual shear melting depended strongly on the
crystal's angular orientation relative to the laser beam. Shear stress and
strain rate were measured, from which the spatially resolved shear viscosity
was calculated. The latter was shown to have minima in the regions with high
velocity shear, thus demonstrating shear thinning. Shear-induced reordering was
observed in the steady-state flow, where particles formed strings aligned in
the flow direction.


title: Ab initio analysis of all income society classes in the European Union

abstract:
  We found a unified formula for description of the household incomes of all
society classes, for instance, of those of the European Union in year 2007.
This formula is a stationary solution of the threshold Fokker-Planck equation
(derived from the threshold nonlinear Langevin one). The formula is more
general than the well known that of Yakovenko et al. because it satisfactorily
describes not only household incomes of low- and medium-income society classes
but also the household incomes of the high-income society class.


title: Variational Equalities of Directed Information and Applications

abstract:
  In this paper we introduce two variational equalities of directed
information, which are analogous to those of mutual information employed in the
Blahut-Arimoto Algorithm (BAA). Subsequently, we introduce nonanticipative Rate
Distortion Function (RDF) ${R}^{na}_{0,n}(D)$ defined via directed information
introduced in [1], and we establish its equivalence to Gorbunov-Pinsker's
nonanticipatory $\epsilon$-entropy $R^{\varepsilon}_{0,n}(D)$. By invoking
certain results we first establish existence of the infimizing reproduction
distribution for ${R}^{na}_{0,n}(D)$, and then we give its implicit form for
the stationary case. Finally, we utilize one of the variational equalities and
the closed form expression of the optimal reproduction distribution to provide
an algorithm for the computation of ${R}^{na}_{0,n}(D)$.


title: Mean field limit for disordered diffusions with singular interactions

abstract:
  Motivated by considerations from neuroscience (macroscopic behavior of large
ensembles of interacting neurons), we consider a population of mean field
interacting diffusions in $\mathbf {R}^m$ in the presence of a random
environment and with spatial extension: each diffusion is attached to one site
of the lattice $\mathbf {Z}^d$, and the interaction between two diffusions is
attenuated by a spatial weight that depends on their positions. For a general
class of singular weights (including the case already considered in the
physical literature when interactions obey to a power-law of parameter
$0<\alpha<d$), we address the convergence as $N\to\infty$ of the empirical
measure of the diffusions to the solution of a deterministic McKean-Vlasov
equation and prove well-posedness of this equation, even in the degenerate case
without noise. We provide also precise estimates of the speed of this
convergence, in terms of an appropriate weighted Wasserstein distance,
exhibiting in particular nontrivial fluctuations in the power-law case when
$\frac{d}{2}\leq\alpha<d$. Our framework covers the case of polynomially
bounded monotone dynamics that are especially encountered in the main models of
neural oscillators.


title:
Optimal Nonstationary Reproduction Distribution for Nonanticipative RDF
  on Abstract Alphabets

abstract:
  In this paper we introduce a definition for nonanticipative Rate Distortion
Function (RDF) on abstract alphabets, and we invoke weak convergence of
probability measures to show various of its properties, such as, existence of
the optimal reproduction conditional distribution, compactness of the fidelity
set, lower semicontinuity of the RDF functional, etc. Further, we derive the
closed form expression of the optimal nonstationary reproduction distribution.
This expression is computed recursively backward in time. Throughout the paper
we point out an operational meaning of the nonanticipative RDF by recalling the
coding theorem derive in \cite{tatikonda2000}, and we state relations to
Gorbunov-Pinsker's nonanticipatory $\epsilon-$entropy \cite{gorbunov-pinsker}.


title: Series expansions and sudden singularities

abstract:
  We construct solutions of the Friedmann equations near a sudden singularity
using generalized series expansions for the scale factor, the density, and the
pressure of the fluid content. In this way, we are able to arrive at a solution
with a sudden singularity containing two free constants, as required for a
general solution of the cosmological equations.


title: Stability of rapidly-rotating charged black holes in $AdS_5 \times S^5$

abstract:
  We study the stability of charged rotating black holes in a consistent
truncation of Type $IIB$ Supergravity on $AdS_5 \times S^5$ that degenerate to
extremal black holes with zero entropy. These black holes have scaling
properties between charge and angular momentum similar to those of Fermi
surface-like operators in a subsector of ${\cal N}=4$ SYM. By solving the
equation of motion for a massless scalar field in this background, using
matched asymptotic expansion followed by a numerical solution scheme, we are
able to compute its Quasi-Normal modes, and analyze it's regime of
(in)stability. We find that the black hole is unstable when its angular
velocity with respect to the horizon exceeds 1 (in units of $1/l_{AdS}$). A
study of the relevant thermodynamic Hessian reveals a local thermodynamic
instability which occurs at the same region of parameter space. We comment on
the endpoints of this instability.


title: Locally conformally flat and self-dual structures on simple 4-manifolds

abstract:
  This is a survey article on the existence of locally conformally flat(LCF)
and self-dual(SD) metrics on various basic 4-manifolds like simply-connected
ones or product types


title: Conserved charge fluctuations with HISQ fermions

abstract:
  We calculate cumulants of fluctuations of net-baryon number, net-electric
charge and net-strangeness, in the framework of lattice regularized QCD. We use
a highly improved staggered quark (HISQ) action on lattices with temporal
extent of N_tau=6,8 and 12 and almost physical quark masses. By means of a
Taylor expansion in various chemical potentials and under demanding both
strangeness neutrality as well as the correct isospin asymmetry, we evaluate
these fluctuations at conditions met in heavy ion collisions. Cumulants of
net-electric charge fluctuations can, in principle, also be measured in heavy
ion experiments. We therefore propose a method to extract freeze-out
parameters, such as the freeze-out temperature and baryon chemical potential,
based on a comparison of lattice results and experimental measurements of two
different ratios of net-electric charge cumulants. As this method involves only
(lattice) QCD results and experimental measurements it is model independent
and, for the purpose of extracting freeze-out parameters, does not require any
input from hadron resonance gas model calculations.


title: High-resolution radio observations of SNR 1987A at high frequencies

abstract:
  We present new imaging observations of the remnant of Supernova (SN) 1987A at
44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA).
The $0\farcs35\times0\farcs23$ resolution of the diffraction-limited image is
the highest achieved to date in high-dynamic range. We also present a new ATCA
image at 18 GHz derived from 2011 observations, which is super-resolved to
$0\farcs25$. The flux density is 40$\pm$2 mJy at 44 GHz and 81$\pm$6 mJy at 18
GHz. At both frequencies, the remnant exhibits a ring-like emission with two
prominent lobes, and an east-west brightness asymmetry that peaks on the
eastern lobe. A central feature of fainter emission appears at 44 GHz. A
comparison with previous ATCA observations at 18 and 36 GHz highlights higher
expansion velocities of the remnant eastern side. The 18-44 GHz spectral index
is $\alpha=-0.80$ ($S_{\nu}\propto\nu^{\alpha}$). The spectral index map
suggests slightly steeper values at the brightest sites on the eastern lobe,
whereas flatter values are associated with the inner regions. The remnant
morphology at 44 GHz generally matches the structure seen with contemporaneous
X-ray and H$\alpha$ observations. Unlike the H$\alpha$ emission, both the radio
and X-ray emission peaks on the eastern lobe. The regions of flatter spectral
index align and partially overlap with the optically-visible ejecta. Simple
free-free absorption models suggest that emission from a pulsar wind nebula or
a compact source inside the remnant may now be detectable at high frequencies,
or at low frequencies if there are holes in the ionised component of the
ejecta.


title: Stability of spin droplets in realistic quantum Hall devices

abstract:
  We study the formation and characteristics of "spin droplets",i.e., compact
spin-polarized configurations in the highest occupied Landau level, in an
etched quantum Hall device at filling factors $2\leq\nu\leq3$. The confining
potential for electrons is obtained with self-consistent electrostatic
calculations on a GaAs/AlGaAs heterostructure with experimental system
parameters. Real-space spin-density-functional calculations for electrons
confined in the obtained potential show the appearance of stable spin droplets
at $\nu\sim 5/2$. The qualitative features of the spin droplet are similar to
those in idealized (parabolic) quantum-dot systems. The universal stability of
the state against geometric deformations underline the applicability of spin
droplets in, e.g., spin-transport through quantum point contacts.


title:
Generalised Multi-sequence Shift-Register Synthesis using Module
  Minimisation

abstract:
  We show how to solve a generalised version of the Multi-sequence Linear
Feedback Shift-Register (MLFSR) problem using minimisation of free modules over
$\mathbb F[x]$. We show how two existing algorithms for minimising such modules
run particularly fast on these instances. Furthermore, we show how one of them
can be made even faster for our use. With our modeling of the problem,
classical algebraic results tremendously simplify arguing about the algorithms.
For the non-generalised MLFSR, these algorithms are as fast as what is
currently known. We then use our generalised MLFSR to give a new fast decoding
algorithm for Reed Solomon codes.


title: Search for magnetic monopoles in polar volcanic rocks

abstract:
  For a broad range of values of magnetic monopole mass and charge, the
abundance of monopoles trapped inside the Earth would be expected to be
enhanced in the mantle beneath the geomagnetic poles. A search for magnetic
monopoles was conducted using the signature of an induced persistent current
following the passage of igneous rock samples through a SQUID-based
magnetometer. A total of 24.6 kg of rocks from various selected sites, among
which 23.4 kg are mantle-derived rocks from the Arctic and Antarctic areas, was
analysed. No monopoles were found and a 90% confidence level upper limit of
$9.8\cdot 10^{-5}$/gram is set on the monopole density in the search samples.


title: Jack polynomials and orientability generating series of maps

abstract:
  We study Jack characters, which are the coefficients of the power-sum
expansion of Jack symmetric functions with a suitable normalization. These
quantities have been introduced by Lassalle who formulated some challenging
conjectures about them. We conjecture existence of a weight on non-oriented
maps (i.e., graphs drawn on non-oriented surfaces) which allows to express any
given Jack character as a weighted sum of some simple functions indexed by
maps. We provide a candidate for this weight which gives a positive answer to
our conjecture in some, but unfortunately not all, cases. In particular, it
gives a positive answer for Jack characters specialized on Young diagrams of
rectangular shape. This candidate weight attempts to measure, in a sense, the
non-orientability of a given map.


title: Analysis of IEEE 802.15.4 MAC under low duty cycle

abstract:
  In this Letter, a discrete-time Markov Chain model is developed to study
performance of IEEE 802.15.4 under low duty cycle. The performance is measured
in terms of aggregate throughput and average power consumption per packet. The
proposed analytical model is verified through ns2 simulations.


title: Tunability of the THz space-charge modulation in a vacuum microdiode

abstract:
  Under certain conditions, space-charge limited emission in vacuum microdiodes
manifests as clearly defined bunches of charge with a regular size and
interval. The frequency corresponding to this interval is in the Terahertz
range. In this computational study it is demonstrated that, for a range of
parameters, conducive to generating THz frequency oscillations, the frequency
is dependant only on the cold cathode electric field and on the emitter area.
For a planar micro-diode of given dimension, the modulation frequency can be
easily tuned simply by varying the applied potential. Simulations of the
microdiode are done for 84 different combinations of emitter area, applied
voltage and gap spacing, using a molecular dynamics based code with exact
Coulomb interaction between all electrons in the vacuum gap, which is of the
order 100. It is found, for a fixed emitter area, that the frequency of the
pulse train is solely dependent on the vacuum electric field in the diode,
described by a simple power law. It is also found that, for a fixed value of
the electric field, the frequency increases with diminishing size of the
emitting spot on the cathode. Some observations are made on the spectral
quality, and how it is affected by the gap spacing in the diode and the initial
velocity of the electrons.


title:
Classical solvability of multidimensional two-phase Stefan problem for
  degenerate parabolic equations

abstract:
  We prove locally in time the existence of a smooth solution for
multidimensional two-phase Stefan problem for degenerate parabolic equations of
the porous medium type. We establish also natural H\"{o}lder class for the
boundary conditions in the Cauchy-Dirichlet problem for a degenerate parabolic
equation.


title:
Infra-red expansion of entanglement entropy in the Interacting Resonant
  Level Model

abstract:
  In this paper we develop a method to describe perturbatively the entanglement
entropy in a simple impurity model, the interacting resonant level model
(IRLM), at low energy (i.e. in the strong coupling regime). We use
integrability results or the Kondo model to describe the infra-red fixed point,
conformal field theory techniques initially developped by Cardy and Calabrese
and a quantization scheme that allows one to compute exactly Renyi entropies at
arbitrary order in $1/T_B$ in principle, even when the system size or the
temperature is finite. We show that those universal quantities at arbitrary
interaction parameter in the strong coupling regime are very well approximated
by the same quantities in the free fermion system in the case of attractive
Coulomb interaction, whereas a strong dependence on the interaction appears in
the case of repulsive interaction.


title:
Tunneling through Al/AlOx/Al junction: analytical models and first
  principles simulations

abstract:
  We study from first principles the transport properties of Al/AlOx/Al tunnel
junctions. On this basis, we analyze the reliability of two analytical models
for the conductance, namely the trapezoid potential barrier model and a
tight-binding model. Our findings show that (i) the interface width used in the
models is determined by the electronic density profile, and it is shorter than
the width one expects from the atomic arrangements; (ii) the effective mass},
found to be about on third of the free electron mass, can be determined from
the oxide band-structure calculations, and (iii) the barrier height is given by
one fourth of the bandgap in the oxide, which explains the apparently small
values found for these junctions experimentally.


title: Vibrational properties of nanographene

abstract:
  The eigenmodes and the vibrational density of states of the ground state
configuration of graphene clusters are calculated using atomistic simulations.
The modified Brenner potential is used to describe the carbon-carbon
interaction and carbon-hydrogen interaction in case of H-passivated edges. For
a given configuration of the C-atoms the eigenvectors and eigenfrequencies of
the normal modes are obtained after diagonalisation of the dynamical matrix
whose elements are the second derivative of the potential energy. The
compressional and shear properties are obtained from the divergence and
rotation of the velocity field. For symmetric and defective clusters with
pentagon arrangement on the edge, the highest frequency modes are shear modes.
The specific heat of the clusters is also calculated within the harmonic
approximation and the convergence to the result for bulk graphene is
investigated.


title: Light curve and spectral evolution of the Type IIb SN 2011fu

abstract:
  We present the low-resolution spectroscopic and UBVRI broad-band photometric
investigations of the Type IIb supernova 2011fu, discovered in UGC 01626. The
photometric follow-up of this event has been initiated a few days after the
explosion and covers a period of about 175 days. The early-phase light curve
shows a rise followed by steep decay in all bands and shares properties very
similar to that seen in case of SN 1993J, with a possible detection of the
adiabatic cooling phase. Modelling of the quasi-bolometric light curve suggests
that the progenitor had an extended ($\sim 1 \times 10^{13}$ cm), low-mass
($\sim 0.1$ $M_\odot$) H-rich envelope on top of a dense, compact ($\sim 2
\times 10^{11}$ cm), more massive ($\sim$ 1.1 $M_\odot$) He-rich core. The
nickel mass synthesized during the explosion was found to be $\sim$ 0.21
$M_\odot$, slightly larger than seen in case of other Type IIb SNe. The
spectral modelling performed with SYNOW suggests that the early-phase line
velocities for H and Fe\,{\sc ii} features were $\sim 16000$ km s$^{-1}$ and
$\sim 14000$ km s$^{-1}$, respectively. Then the velocities declined up to day
+40 and became nearly constant at later epochs.


title:
Baryon Transverse Momentum Distributions at LHC and the "Knee" in Cosmic
  Proton Spectrum

abstract:
  The transverse momentum spectra of hyperons from LHC experiments (ALICE,
ATLAS, CMS) are considered from the point of view of Quark-Gluon String Model
(QGSM) as examples of typical baryon spectra at very high energies. The LHC
data at \sqrt{s} = 0.9 and 7 TeV and STAR data at \sqrt{s} = 200 GeV are fitted
with the universal QGSM formula that includes the energy dependent slope as the
main parameter. The dependence of <Pt> on the collision energy has been
obtained with the help of this formula. The asymptotics of the energy
dependence of average transverse momenta shows the expected pomeronic behavior
~ s^0,12. This conclusion is very important for cosmic ray physics. It means
that the long debated "knee" in the cosmic proton spectra at E_p= 4 10^15 eV in
laboratory system can not be considered any more as the result of dramatic
changes in the dynamics of baryon hadroproduction. In the same time it may
indicate the maximal energy of protons that are being produced in our Galaxy.
This last conclusion depends on the hadroproduction model.


title:
On the limiting distribution of some numbers of crossings in set
  partitions

abstract:
  We study the asymptotic distribution of the two following combinatorial
parameters: the number of arc crossings in the linear representation, ${\mathrm
cr^{(\ell)}$, and the number of chord crossings in the circular representation,
${\mathrm cr^{(c)}$, of a random set partition. We prove that, for $k\leq
n/(2\,\log n)$ (resp., ${k=o(\sqrt{n})}$), the distribution of the parameter
${\mathrm cr^{(\ell)}$ (resp., ${\mathrm cr^{(c)}$) taken over partitions of
$[n]:=\{1,2,...,n\}$ into $k$ blocks is, after standardization, asymptotically
Gaussian as $n$ tends to infinity. We give exact and asymptotic formulas for
the variance of the distribution of the parameter ${\mathrm cr^{(\ell)}$ from
which we deduce that the distribution of ${\mathrm cr^{(\ell)}$ and ${\mathrm
cr^{(c)}$ taken over all partitions of $[n]$ is concentrated around its mean.
The proof of these results relies on a standard analysis of generating
functions associated with the parameter ${\mathrm cr^{(\ell)}$ obtained in
earlier work of Stanton, Zeng and the author. We also determine the maximum
values of the parameters ${\mathrm cr^{(\ell)}$ and ${\mathrm cr^{(c)}$.


title:
Pattern dynamics near homoclinic bifurcation in Rayleigh-B\'{e}nard
  convection

abstract:
  We report for the first time the pattern dynamics in the vicinity of an
inverse homoclinic bifurcation in an extended dissipative system. We observe,
in direct numerical simulations of three dimensional Rayleigh-B\'{e}nard
convection, a spontaneous breaking of a competition of two mutually
perpendicular sets of oscillating cross rolls to one of two possible sets of
oscillating cross rolls as the Rayleigh number is raised above a critical
value. The time period of the cross-roll patterns diverges, and shows scaling
behavior near the bifurcation point. This is an example of a transition from
nonlocal to local pattern dynamics near an inverse homoclinic bifurcation. We
also present a simple four-mode model that captures the pattern dynamics quite
well.


title:
Few-body hierarchy in non-relativistic functional renormalization group
  equations and a decoupling theorem

abstract:
  For non-relativistic quantum field theory in the few-body limit with
instantaneous interactions it is shown within the functional renormalization
group formalism that propagators are not renormalized and that the
renormalization group equations of one-particle irreducible vertex functions
are governed by a hierarchical structure. This hierarchy allows to solve the
equations in the n-body sector without knowledge or assumptions about the
m-body sectors where m>n.


title:
Proposed Detection of Time Reversal Symmetry in Topological Surface
  States

abstract:
  By employing T-matrix approach, we investigate a nonmagnetic impurity located
on the surface of three-dimensional topological insulators, where the time
reversal symmetry is preserved. It is shown that the images of the local
density of states (LDOS) around the single impurity have the dip-hump
structures with six-fold symmetry at different bias voltages. The peaks are
produced by quasiparticle interference while the local minima at the
backscattering wave vectors are due to the absence of backscatterings. With
increasing the bias voltage, the peaks and dips move forward to the location of
the impurity. These dips at the backscattering wave vectors in the LDOS spectra
can be regarded as a signature of the time reversal symmetry in the topological
surface states, which could be observed by scanning tunneling microscopy.


title:
Spin filter effect at room temperature in GaN/GaMnN ferromagnetic
  resonant tunneling diode

abstract:
  We have investigated the spin current polarization without the external
magnetic field in the resonant tunneling diode with the emitter and quantum
well layers made from the ferromagnetic GaMnN. For this purpose we have applied
the self-consistent Wigner-Poisson method and studied the spin-polarizing
effect of the parallel and antiparallel alignment of the magnetization in the
ferromagnetic layers. The results of our calculations show that the
antiparallel magnetization is much more advantageous for the spin filter
operation and leads to the full spin current polarization at low temperatures
and 35 % spin polarization of the current at room temperature.


title:
Does Magnetic Field-Rotation Misalignment Solve the Magnetic Braking
  Catastrophe in Protostellar Disk Formation?

abstract:
  Stars form in dense cores of molecular clouds that are observed to be
significantly magnetized. In the simplest case of a laminar (non-turbulent)
core with the magnetic field aligned with the rotation axis, both analytic
considerations and numerical simulations have shown that the formation of a
large, $10^2\au$-scale, rotationally supported protostellar disk is suppressed
by magnetic braking in the ideal MHD limit for a realistic level of core
magnetization. This theoretical difficulty in forming protostellar disks is
termed "magnetic braking catastrophe". A possible resolution to this problem,
proposed by \citeauthor{HennebelleCiardi2009} and \citeauthor{Joos+2012}, is
that misalignment between the magnetic field and rotation axis may weaken the
magnetic braking enough to enable disk formation. We evaluate this possibility
quantitatively through numerical simulations. We confirm the basic result of
\citeauthor{Joos+2012} that the misalignment is indeed conducive to disk
formation. In relatively weakly magnetized cores with dimensionless
mass-to-flux ratio $\gtrsim 5$, it enabled the formation of rotationally
supported disks that would otherwise be suppressed if the magnetic field and
rotation axis are aligned. For more strongly magnetized cores, disk formation
remains suppressed, however, even for the maximum tilt angle of $90\degree$. If
dense cores are as strongly magnetized as indicated by OH Zeeman observations
(with a mean dimensionless mass-to-flux ratio $\sim 2$), it would be difficult
for the misalignment alone to enable disk formation in the majority of them. We
conclude that, while beneficial to disk formation, especially for the
relatively weak field case, the misalignment does not completely solve the
problem of catastrophic magnetic braking in general.


title:
The contribution of the Warm-Hot Intergalactic Medium to the CMB
  anisotropies via the Sunyaev-Zeldovich effect

abstract:
  Cosmological hydrodynamical simulations predict that a large fraction of all
baryons reside within mildly non-linear structures with temperatures in the
range $10^{5}-10^{7}$K. As the gas is highly ionized, it could be detected by
the temperature anisotropies generated on the Cosmic Microwave Background
radiation. We refine our previous estimates of the thermal Sunyaev-Zeldovich
effect by introducing a non-polytropic equation of state to model the
temperature distribution of the shock heated gas derived from
temperature-density phase diagrams of different hydrodynamical simulations.
Depending on the specific model, the Comptonization parameter varies in the
range $10^{-7}\le y_c \le 2\times 10^{-6}$, compatible with the FIRAS upper
limit. This amplitude is in agreement with a simple toy model constructed to
estimate the average effect induced by filaments of ionized gas. Using the
log-normal probability density function we calculate the correlation function
and the power spectrum of the temperature anisotropies generated by the WHIM
filaments. For a wide range of the parameter space, the maximum amplitude of
the radiation power spectrum is $(\ell+1)\ell C_{\ell}/2\pi =0.7-70(\mu K)^2$
at $\ell \approx 200-500$. This amplitude scales with baryon density, Hubble
constant and the amplitude of the matter power spectrum $\sigma_8$ as
$[(\ell+1)\ell C_\ell]_{\mathrm{max}}/2\pi \propto \sigma_8^{2.6}(\Omega_b
h)^2$. Since the thermal Sunyaev-Zeldovich effect has a specific frequency
dependence, we analyze the possibility of detecting this component with the
forthcoming Planck data.


title: The infinitely many genes model with horizontal gene transfer

abstract:
  The genome of bacterial species is much more flexible than that of
eukaryotes. Moreover, the distributed genome hypothesis for bacteria states
that the total number of genes present in a bacterial population is greater
than the genome of every single individual. The pangenome, i.e. the set of all
genes of a bacterial species (or a sample), comprises the core genes which are
present in all living individuals, and accessory genes, which are carried only
by some individuals. In order to use accessory genes for adaptation to
environmental forces, genes can be transferred horizontally between
individuals. Here, we extend the infinitely many genes model from Baumdicker,
Hess and Pfaffelhuber (2010) for horizontal gene transfer. We take a
genealogical view and give a construction -- called the Ancestral Gene Transfer
Graph -- of the joint genealogy of all genes in the pangenome. As application,
we compute moments of several statistics (e.g. the number of differences
between two individuals and the gene frequency spectrum) under the infinitely
many genes model with horizontal gene transfer.


title: Harrison metrics for the Schwarzschild black hole

abstract:
  Based on the hidden conformal symmetry, some authors have proposed a Harrison
metric for the Schwarzschild black hole. We give a procedure which can generate
a family of Harrison metrics starting from a general set of SL(2, R) vector
fields. By analogy with the subtracted geometry of the Kerr black hole, we find
a new Harrison metric for the Schwarzschild case. Its conformal generators are
also investigated using the Killing equations in the near-horizon limit.


title: On some automatic continuity theorems

abstract:
  We give characterizations of unital uniform topological algebras and
saturated locally multiplicatively convex algebras by means of multiplicative
linear functionals. Some automatic continuity theorems in advertibly complete
uniform topological algebras are extended to a larger class of algebras.
Consequences and applications are given.


title: The CLASS BL Lac sample: The Radio Luminosity Function

abstract:
  This paper presents a new sample of BL Lac objects selected from a deep (30
mJy) radio survey of flat spectrum radio sources (the CLASS blazar survey,
henceforth CBS). The sample is one of the largest well defined samples in the
low power regime with a total of 130 sources of which 55 satisfy the
'classical' optical BL Lac selection criteria, and the rest have
indistinguishable radio properties. The primary goal of this study is to
establish the Radio Luminosity Function (RLF) on firm statistical ground at low
radio luminosities where previous samples have not been able to investigate.
The gain of taking a peek at lower powers is the possibility to search for the
flattening of the LF which is a feature predicted by the beaming model but
which has remained elusive to observational confirmation. In this study we
extend for the first time the BL Lac RLF down to very low radio powers ~10^22
W/Hz, ie, two orders of magnitude below the RLF currently available in the
literature. In the process we confirm the importance of adopting a broader, and
more physically meaningful set of classification criteria to avoid the
systematic missing of low luminosity BL Lacs. Thanks to the good statistics we
confirm the existence of weak but significant positive cosmological evolution
for the BL Lac population, and we detect, for the first time the flattening of
the RLF at ~10^25 W/Hz in agreement with the predictions of the beaming model.


title: Annotated Interview with a QBist in the Making

abstract:
  These are my published answers to the seventeen questions posed by Max
Schlosshauer in his 2011 book "Elegance and Enigma: the Quantum Interviews". I
have inserted thirty footnotes into those answers, commenting on them from the
perspective of subsequent insights I acquired during six weeks in March and
April of 2012 with Chris Fuchs and Ruediger Schack at the Stellenbosch
Institute for Advanced Study. Aside from the footnotes and a few introductory
paragraphs, the text is identical to my contributions to the Schlosshauer
volume.


title: To the study of non-Gaussianity in two-field slow-roll inflation

abstract:
  The general expression for the second order large scale curvature
perturbation in the form of a functional over a background solution is derived.
The explicit expressions was obtained for two special forms of the inflationary
potential. In the considered cases, it is shown that a significant level of
non-Gaussianity can be generated during the super-Hubble evolution only if
nonadiabatic perturbations are non-negligible at the end of inflation.


title: Chatty Mobiles:Individual mobility and communication patterns

abstract:
  Human mobility analysis is an important issue in social sciences, and
mobility data are among the most sought-after sources of information in ur-
Data ban studies, geography, transportation and territory management. In
network sciences mobility studies have become popular in the past few years,
especially using mobile phone location data. For preserving the customer
privacy, datasets furnished by telecom operators are anonymized. At the same
time, the large size of datasets often makes the task of calculating all
observed trajectories very difficult and time-consuming. One solution could be
to sample users. However, the fact of not having information about the mobile
user makes the sampling delicate. Some researchers select randomly a sample of
users from their dataset. Others try to optimize this method, for example,
taking into account only users with a certain number or frequency of locations
recorded. At the first glance, the second choice seems to be more efficient:
having more individual traces makes the analysis more precise. However, the
most frequently used CDR data (Call Detail Records) have location generated
only at the moment of communication (call, SMS, data connection). Due to this
fact, users mobility patterns cannot be precisely built upon their
communication patterns. Hence, these data have evident short-comings both in
terms of spatial and temporal scale. In this paper we propose to estimate the
correlation between the users communication and mo- bility in order to better
assess the bias of frequency based sampling. Using technical GSM network data
(including communication but also independent mobility records), we will
analyze the relationship between communication and mobility patterns.


title:
How (not) to assess the importance of correlations for the matching of
  spontaneous and evoked activity

abstract:
  A comment on `Population rate dynamics and multineuron firing patterns in
sensory cortex' by Okun et al. Journal of Neuroscience 32(48):17108-17119, 2012
and our response to the corresponding reply by Okun et al's (arXiv, 2013).


title:
Spitzer Observations of GJ3470b: a Very Low-density Neptune-size Planet
  Orbiting a Metal-rich M dwarf

abstract:
  We present Spitzer/IRAC 4.5-micron transit photometry of GJ3470b, a
Neptune-size planet orbiting a M1.5 dwarf star with a 3.3-day period recently
discovered in the course of the HARPS M-dwarf survey. We refine the stellar
parameters by employing purely empirical mass-luminosity and surface brightness
relations constrained by our updated value for the mean stellar density, and
additional information from new near-infrared spectroscopic observations. We
derive a stellar mass of M_star = 0.539+0.047-0.043 M_sun and a radius of
R_star = 0.568+0.037-0.031 R_sun. We determine the host star of GJ3470b to be
metal-rich, with a metallicity of [Fe/H] = +0.20 +/- 0.10 and an effective
temperature of Teff = 3600 +/- 100 K. The revised stellar parameters yield a
planetary radius R_pl = 4.83+0.22-0.21 R_Earth that is 13 percent larger than
the value previously reported in the literature. We find a planetary mass M_pl
= 13.9+1.5-1.4 M_Earth that translates to a very low planetary density, rho_pl
= 0.72+0.13-0.12 gcm-3, which is 33% smaller than the original value. With a
mean density half of that of GJ436b, GJ3470b is an example of a very
low-density low-mass planet, similar to Kepler-11d, Kepler-11e, and Kepler-18c
but orbiting a much brighter nearby star that is more conducive to follow-up
studies.


title: Design constraints on Cherenkov telescopes with Davies-Cotton reflectors

abstract:
  This paper discusses the construction of high-performance ground-based
gamma-ray Cherenkov telescopes with a Davies-Cotton reflector. For the design
of such telescopes, usually physics constrains the field-of-view, while the
photo-sensor size is defined by limited options. Including the effect of
light-concentrators in front of the photo sensor, it is demonstrated that these
constraints are enough to mutually constrain all other design parameters. The
dependability of the various design parameters naturally arises once a
relationship between the value of the point-spread functions at the edge of the
field-of-view and the pixel field-of-view is introduced. To be able to include
this constraint into a system of equations, an analytical description for the
point-spread function of a tessellated Davies-Cotton reflector is derived from
Taylor developments and ray-tracing simulations. Including higher order terms
renders the result precise on the percent level.
  Design curves are provided within the typical phase space of Cherenkov
telescopes. The impact of all design parameters on the overall design is
discussed. Allowing an immediate comparison of several options with identical
physics performance allows the determination of the most cost efficient
solution. Emphasize is given on the possible application of solid light
concentrators with their typically about two times better concentration
allowing the use of small photo sensors such as Geiger-mode avalanche photo
diodes. This is discussed in more details in the context of possible design
options for the Cherenkov Telescope Array. In particular, a solution for a
60\,mm(^2) photo sensor with hollow cone is compared to a 36\,mm(^2) with solid
cone.


title: Results of a Search for Paraphotons with Intense X-ray Beams at SPring-8

abstract:
  A search for paraphotons, or hidden U(1) gauge bosons, is performed using an
intense X-ray beamline at SPring--8. "Light Shining through a Wall" technique
is used in this search. No excess of events above background is observed. A
stringent constraint is obtained on the photon--paraphoton mixing angle, $\chi
< 8.06\times 10^{-5}\ (95%\ {\rm C.L.})$ for $0.04\ {\rm
eV}<m_{\gamma^{\prime}} < 26\ {\rm keV}$.


title: Chiral magnetic effect and holography

abstract:
  The chiral magnetic effect (CME) is a highly discussed effect in heavy-ion
collisions stating that, in the presence of a magnetic field B, an electric
current is generated in the background of topologically nontrivial gluon
fields. We present a holographic (AdS/CFT) description of the CME in terms of a
fluid-gravity model which is dual to a strongly-coupled plasma with multiple
anomalous U(1) currents. In the case of two U(1) charges, one axial and one
vector, the CME formally appears as a first-order transport coefficient in the
vector current. We will holographically compute this coefficient at strong
coupling and compare it with the hydrodynamic result. Finally, we will discuss
an anisotropic variant of the model and study a possible dependence of the CME
on the elliptic flow coefficient v_2.


title:
Clustering Via Nonparametric Density Estimation: the R Package
  pdfCluster

abstract:
  The R package pdfCluster performs cluster analysis based on a nonparametric
estimate of the density of the observed variables. After summarizing the main
aspects of the methodology, we describe the features and the usage of the
package, and finally illustrate its working with the aid of two datasets.


title:
Study of some parameters interstellar transport using of magnetic
  umbrella

abstract:
  Interstellar transport is an object of interest in many sci-fi stories. In
history a lot of sci-fi predictions have turned into reality, such as
communications satellites, deep-sea submarines and journies to the moon. In
this work we study some physical parameters of a space ship which uses a
magnetic umbrella. Our spaceship generates a magnetic field in its neighborhood
and captures charged protons into a magnetic trap. These particles are taken
into a fusion reactor. The obtained energy and waste in form of helium are used
as a fuel in an ion engine. With the help of elementary physics we can work out
the basic physical parameters of the ship, e.g. maximal velocity, acceleration
of the ship or acceleration time period.


title:
Can high risk fungicides be used in mixtures without selecting for
  fungicide resistance?

abstract:
  Fungicide mixtures produced by the agrochemical industry often contain
low-risk fungicides, to which fungal pathogens are fully sensitive, together
with high-risk fungicides known to be prone to fungicide resistance. Can these
mixtures provide adequate disease control while minimizing the risk for the
development of resistance? We present a population dynamics model to address
this question. We found that the fitness cost of resistance is a crucial
parameter to determine the outcome of competition between the sensitive and
resistant pathogen strains and to assess the usefulness of a mixture. If
fitness costs are absent, then the use of the high-risk fungicide in a mixture
selects for resistance and the fungicide eventually becomes nonfunctional. If
there is a cost of resistance, then an optimal ratio of fungicides in the
mixture can be found, at which selection for resistance is expected to vanish
and the level of disease control can be optimized.


title:
Error-Driven Dynamical hp-Meshes with the Discontinuous Galerkin Method
  for Three-Dimensional Wave Propagation Problems

abstract:
  An hp-adaptive Discontinuous Galerkin Method for electromagnetic wave
propagation phenomena in the time-domain is proposed. The method is highly
efficient and allows for the first time the adaptive full-wave simulation of
transient problems in three-dimensional space. Refinement is performed
anisotropically in the approximation order, p, and the mesh step size, h,
regardless of the resulting level of hanging nodes. For guiding the adaptation
process a variant of the concept of reference solutions with largely reduced
computational costs is proposed. The computational mesh is adapted such that a
given error tolerance is respected throughout the entire time-domain
simulation.


title:
Magnetization dynamics in Co2$MnGe/Al2$O3$/Co tunnel junctions grown on
  different substrates

abstract:
  We study static and dynamic magnetic properties of Co2MnGe (13 nm)/Al2O3 (3
nm)/Co (13 nm) tunnel magnetic junctions (TMJ), deposited on various single
crystalline substrates (a-plane sapphire, MgO(100), Si(111)). The results are
compared to the magnetic properties of Co and of Co$_{2}$MnGe single films
lying on sapphire substrates. X-rays diffraction always shows a (110)
orientation of the Co$_{2}$MnGe films. Structural observations obtained by high
resolution transmission electron microscopy confirmed the high quality of the
TMJ grown on sapphire. Our vibrating sample magnetometry measurements reveal
in-plane anisotropy only in samples grown on a sapphire substrate. Depending on
the substrate, the ferromagnetic resonance spectra of the TMJs, studied by the
microstrip technique, show one or two pseudo-uniform modes. In the case of MgO
and of Si substrates only one mode is observed: it is described by magnetic
parameters (g-factor, effective magnetization, in-plane magnetic anisotropy)
derived in the frame of a simple expression of the magnetic energy density;
these parameters are practically identical to those obtained for the Co single
film. With a sapphire substrate two modes are present: one of them does not
appreciably differ from the observed mode in the Co single film while the other
one is similar to the mode appearing in the Co$_{2}$MnGe single film: their
magnetic parameters can thus be determined independently, using a classical
model for the energy density in the absence of interlayer exchange coupling.


title:
Comparison of f-Q scaling in wineglass and radial modes in ring
  resonators

abstract:
  Low phase noise MEMS oscillators necessitate resonators with high f-Q.
Resonators achieving high f-Q (mechanical frequency-quality factor product)
close to the thermo-elastic damping (TED) limit have been demonstrated at
expense of feed-through. Here we present a study comparing frequency scaling of
quality factors of wineglass and radial modes in a ring resonator using an
opto-mechanical two port transmission measurement. Higher harmonics of the
wineglass mode show an increasing trend in the f-Q product, as compared to a
saturation of f-Q for radial modes. The measured f-Q of 5.11e13Hz at 9.82GHz in
air at room temperature for a wineglass mode is close to the highest measured
values in silicon resonators.


title: Tripartite Composite Fermion States

abstract:
  The Read-Rezayi wave function is one of the candidates for the fractional
quantum Hall effect at filling fraction $\nu=2+\nicefrac{3}{5}$, and thereby
also its hole conjugate at $2+\nicefrac{2}{5}$. We study a general class of
"tripartite" composite fermion wave functions, which reduce to the Read-Rezayi
ground state and quasiholes for appropriate quantum numbers, but also allow a
construction of wave functions for quasiparticles and neutral excitations by
analogy to the standard composite fermion theory. We present numerical evidence
in finite systems that these trial wave functions capture well the low energy
physics of a 4-body model interaction. We also compare the tripartite composite
fermion wave functions with the exact Coulomb eigenstates at
$2+\nicefrac{3}{5}$, and find reasonably good agreement. The ground state as
well as several excited states of the 4-body interaction are seen to evolve
adiabatically into the corresponding Coulomb states for N=15 particles. These
results support the plausibility of the Read-Rezayi proposal for the
$2+\nicefrac{2}{5}$ and $2+\nicefrac{3}{5}$ fractional quantum Hall effect.
However, certain other proposals also remain viable, and further study of
excitations and edge states will be necessary for a decisive establishment of
the physical mechanism of these fractional quantum Hall states.


title: A compact high-flux source of cold sodium atoms

abstract:
  We present a compact source of cold sodium atoms suitable for the production
of quantum degenerate gases and versatile for a multi-species experiment. The
magnetic field produced by permanent magnets allows to simultaneously realize a
Zeeman slower and a two-dimensional MOT within an order of magnitude smaller
length than standard sodium sources. We achieve an atomic flux exceeding 4x10^9
atoms/s loaded in a MOT, with a most probable longitudinal velocity of 20 m/s,
and a brightness larger than 2.5x10^(12) atoms/s/sr. This atomic source allowed
us to produce a pure BEC with more than 10^7 atoms and a background pressure
limited lifetime of 5 minutes.


title: Atomic clock transitions in silicon-based spin qubits

abstract:
  A major challenge in using spins in the solid state for quantum technologies
is protecting them from sources of decoherence. This can be addressed, to
varying degrees, by improving material purity or isotopic composition for
example, or active error correction methods such as dynamic decoupling, or even
combinations of the two. However, a powerful method applied to trapped ions in
the context of frequency standards and atomic clocks, is the use of particular
spin transitions which are inherently robust to external perturbations. Here we
show that such `clock transitions' (CTs) can be observed for electron spins in
the solid state, in particular using bismuth donors in silicon. This leads to
dramatic enhancements in the electron spin coherence time, exceeding seconds.
We find that electron spin qubits based on CTs become less sensitive to the
local magnetic environment, including the presence of 29Si nuclear spins as
found in natural silicon. We expect the use of such CTs will be of additional
importance for donor spins in future devices, mitigating the effects of
magnetic or electric field noise arising from nearby interfaces.


title: The total run length of a word

abstract:
  A run in a word is a periodic factor whose length is at least twice its
period and which cannot be extended to the left or right (by a letter) to a
factor with greater period. In recent years a great deal of work has been done
on estimating the maximum number of runs that can occur in a word of length
$n$. A number of associated problems have also been investigated. In this paper
we consider a new variation on the theme. We say that the total run length
(TRL) of a word is the sum of the lengths of the runs in the word and that
$\tau(n)$ is the maximum TRL over all words of length $n$. We show that $n^2/8
< \tau(n) < 47n^2/72 + 2n$ for all $n$. We also give a formula for the average
total run length of words of length $n$ over an alphabet of size $\alpha$, and
some other results.


title: Superbosonisation via Riesz superdistributions

abstract:
  The superbosonisation identity of Littelmann-Sommers-Zirnbauer is a new tool
to study universality of random matrix ensembles via supersymmetry, which is
applicable to non-Gaussian invariant distributions. In this note, we identify
the right-hand side with a super-generalisation of the Riesz distribution.
Using the Laplace transformation and tools from harmonic superanalysis, we give
a short and conceptual new proof of the formula.


title: Wavelets in Field Theory

abstract:
  We advocate the use of Daubechies wavelets as a basis for treating a variety
of problems in quantum field theory. This basis has both natural large volume
and short distance cutoffs, has natural partitions of unity, and the basis
functions are all related to the fixed point of a linear renormalization group
equation.


title:
GW quasiparticle band structures of stibnite, antimonselite,
  bismuthinite, and guanajuatite

abstract:
  We present first-principles calculations of the quasiparticle band structures
of four isostructural semiconducting metal chalcogenides A$_2$B$_3$ (with A =
Sb, Bi and B = S, Se) of the stibnite family within the G$_0$W$_0$ approach. We
perform extensive convergence tests and identify a sensitivity of the
quasiparticle corrections to the structural parameters and to the semicore $d$
electrons. Our calculations indicate that all four chalcogenides exhibit direct
band gaps, if we exclude some indirect transitions marginally below the direct
gap. Relativistic spin-orbit effects are evaluated for the Kohn-Sham band
structures, and included as scissor corrections in the quasiparticle band gaps.
Our calculated band gaps are 1.5 eV (Sb$_2$S$_3$), 1.3 eV (Sb$_2$Se$_3$), 1.4
eV (Bi$_2$S$_3$) and 0.9 eV (Bi$_2$Se$_3$). By comparing our calculated gaps
with the ideal Shockley-Queisser value we find that all four chalcogenides are
promising as light sensitizers for nanostructured photovoltaics.


title: {\omega}-Petri nets

abstract:
  We introduce {\omega}-Petri nets ({\omega}PN), an extension of plain Petri
nets with {\omega}-labeled input and output arcs, that is well-suited to
analyse parametric concurrent systems with dynamic thread creation. Most
techniques (such as the Karp and Miller tree or the Rackoff technique) that
have been proposed in the setting of plain Petri nets do not apply directly to
{\omega}PN because {\omega}PN define transition systems that have infinite
branching. This motivates a thorough analysis of the computational aspects of
{\omega}PN. We show that an {\omega}PN can be turned into an plain Petri net
that allows to recover the reachability set of the {\omega}PN, but that does
not preserve termination. This yields complexity bounds for the reachability,
(place) boundedness and coverability problems on {\omega}PN. We provide a
practical algorithm to compute a coverability set of the {\omega}PN and to
decide termination by adapting the classical Karp and Miller tree construction.
We also adapt the Rackoff technique to {\omega}PN, to obtain the exact
complexity of the termination problem. Finally, we consider the extension of
{\omega}PN with reset and transfer arcs, and show how this extension impacts
the decidability and complexity of the aforementioned problems.


title: Turbulent Shear Acceleration

abstract:
  We consider particle acceleration by large-scale incompressible turbulence
with a lengthscale larger than the particle mean free path. We derive an
ensemble-averaged transport equation of energetic charged particles from an
extended transport equation which contains the shear acceleration. The
ensemble-averaged transport equation describes particle acceleration by
incompressible turbulence (turbulent shear acceleration). We find that for
Kolmogorov turbulence, the turbulent shear acceleration becomes important in
small scale. Moreover, by Monte Carlo simulations, we confirm that the
ensemble-averaged transport equation describes the turbulent shear
acceleration.


title:
Self-Organizing Map and social networks: Unfolding online social
  popularity

abstract:
  The present study uses the Kohonen self organizing map (SOM) to represent the
popularity patterns of Myspace music artists from their attributes on the
platform and their position in the social network. The method is applied to
cluster the profiles (the nodes of the social network) and the best friendship
links (the edges). It shows that the SOM is an efficient tool to interpret the
complex links between the audience and the influence of the musicians. It
finally provides a robust classifier of the online social network behaviors.


title: Searches for very rare decays to purely leptonic final states at LHCb

abstract:
  We present a review of the searches for very rare decays to muonic final
states performed at LHCb using 1.0 fb-1 of pp collisions at 7 TeV centre of
mass energy. Flavour changing neutral current processes, such as B->mumu and
B->mumumumu are highly suppressed in the Standard Model (SM). Such decays
therefore allow contributions from new processes or new heavy particles to
significantly modify the expected SM rates. Charged lepton flavour violating
processes, such as the neutrino-less tau->mumumu decay, have vanishingly small
decay rates in the SM, but can be significantly enhanced in extended models. We
report the latest results on these channels from LHCb.


title: Web worlds, web-colouring matrices, and web-mixing matrices

abstract:
  We introduce a new combinatorial object called a web world that consists of a
set of web diagrams. The diagrams of a web world are generalizations of graphs,
and each is built on the same underlying graph. Instead of ordinary vertices
the diagrams have pegs, and edges incident to a peg have different heights on
the peg. The web world of a web diagram is the set of all web diagrams that
result from permuting the order in which endpoints of edges appear on a peg.
The motivation comes from particle physics, where web diagrams arise as
particular types of Feynman diagrams describing scattering amplitudes in
non-Abelian gauge (Yang-Mills) theories. To each web world we associate two
matrices called the web-colouring matrix and web-mixing matrix. The entries of
these matrices are indexed by ordered pairs of web diagrams (D_1,D_2), and are
computed from those colourings of the edges of D_1 that yield D_2 under a
transformation determined by each colouring.
  We show that colourings of a web diagram (whose constituent indecomposable
diagrams are all unique) that lead to a reconstruction of the diagram are
equivalent to order-preserving mappings of certain partially ordered sets
(posets) that may be constructed from the web diagrams. For web worlds whose
web graphs have all edge labels equal to 1, the diagonal entries of web-mixing
and web-colouring matrices are obtained by summing certain polynomials
determined by the descents in permutations in the Jordan-Holder set of all
linear extensions of the associated poset. We derive tri-variate generating
generating functions for the number of web worlds according to three statistics
and enumerate the number of different web diagrams in a web world. Three
special web worlds are examined in great detail, and the traces of the
web-mixing matrices calculated in each case.


title: Experimental Observation of Quantum Holographic Imaging

abstract:
  We report the first experimental observation of quantum holographic imaging
with entangled photon pairs, generated in a spontaneous parametric
down-conversion process. The signal photons play both roles of "object wave"
and "reference wave" in holography but are recorded by a point detector
providing only encoding information, while the idler photons travel freely and
are locally manipulated with spatial resolution. The holographic image is
formed by the two-photon correlation measurement, although both the signal and
idler beams are incoherent. According to the detection regime of the signal
photons, we analyze three types of quantum holography schemes: point detection,
coherent detection and bucket detection, which can correspond to classical
holography using a point source, a plane-wave coherent source and a spatially
incoherent source, respectively. Our experiment demonstrates that the
two-photon holography in the point detection regime is equivalent to the
one-photon holography using a point source. Physically, the quantum holography
experiment verifies that a pair of non-commutable physical quantities, the
amplitude and phase components of the field operator, can be nonlocally
measured through two-photon entanglement.


title: Plasmons in spin-orbit coupled two-dimensional hole gas systems

abstract:
  We study the dynamical dielectric function of a two-dimensional hole gas,
exemplified on [001]-GaAs and InAs quantum wells, within the Luttinger model
extended to the two lowest subbands including bulk and structure inversion
asymmetric terms. The plasmon dispersion shows a pronounced anisotropy for
GaAs- and InAs-based systems. In GaAs this leads to a suppression of plasmons
due to Landau damping in some orientations. Due to the large Rashba
contribution in InAs, the lifetime of plasmons can be controlled by changing
the electric field. This effect is potentially useful in plasmon field effect
transistors as previously proposed for electron gases.


title:
From pseudo-random walk to pseudo-Brownian motion: first exit time from
  a one-sided or a two-sided interval

abstract:
  Let $N$ be a positive integer, $c$ be a positive constant and $(U_n)_{n\ge
1}$ be a sequence of independent identically distributed pseudo-random
variables. We assume that the $U_n$'s take their values in the discrete set
$\{-N,-N+1,...,N-1,N\}$ and that their common pseudo-distribution is
characterized by the \textit{(positive or negative) real} numbers
\[\mathbb{P}\{U_n=k\}=\delta_{k0}+(-1)^{k-1} c\binom{2N}{k+N}\] for any
$k\in\{-N,-N+1,...,N-1,N\}$. Let us finally introduce $(S_n)_{n\ge 0}$ the
associated pseudo-random walk defined on $\mathbb{Z}$ by $S_0=0$ and
$S_n=\sum_{j=1}^n U_j$ for $n\ge 1$.
  In this paper, we exhibit some properties of $(S_n)_{n\ge 0}$. In particular,
we explicitly determine the pseudo-distribution of the first overshooting time
of a given threshold for $(S_n)_{n\ge 0}$ as well as that of the first exit
time from a bounded interval.
  Next, with an appropriate normalization, we pass from the pseudo-random walk
to the pseudo-Brownian motion driven by the high-order heat-type equation
$\partial/\partial t=(-1)^{N-1} c\;\partial^{2N}/$ $\partial x^{2N}$. We
retrieve the corresponding pseudo-distribution of the first overshooting time
of a threshold for the pseudo-Brownian motion (Lachal, A.: First hitting time
and place, monopoles and multipoles for pseudo-processes driven by the equation
$\frac{\partial}{\partial t}=\pm \frac{\partial^N}{\partial x^N}$. Electron. J.
Probab. 12 (2007), 300--353 [MR2299920]). In the same way, we get the
pseudo-distribution of the first exit time from a bounded interval for the
pseudo-Brownian motion which is a new result for this pseudo-process.


title:
Pressure jump interface law for the Stokes-Darcy coupling: Confirmation
  by direct numerical simulations

abstract:
  It is generally accepted that the effective velocity of a viscous flow over a
porous bed satisfies the Beavers-Joseph slip law. To the contrary, interface
law for the effective stress has been a subject of controversy. Recently, a
pressure jump interface law has been rigorously derived by Marciniak-Czochra
and Mikeli\'c. In this paper, we provide a confirmation of the analytical
result using direct numerical simulation of the flow at the microscopic level.


title:
Curvature-dimension inequalities and Li-Yau inequalities in
  sub-Riemannian spaces

abstract:
  In this paper we present a survey of the joint program with Fabrice Baudoin
originated with the paper \cite{BG1}, and continued with the works \cite{BG2},
\cite{BBG}, \cite{BG3} and \cite{BBGM}, joint with Baudoin, Michel Bonnefont
and Isidro Munive.


title: mm-VLBI observations of the active galaxy 3C 111 in outburst

abstract:
  The broad-line radio galaxy 3C 111 exhibited a major flux density outburst in
2007. Here, we present imaging and preliminary kinematic results of the jet,
based on three millimetre-VLBI observations (86 GHz) using the Global
Millimeter VLBI Array (GMVA) covering one year just after the radio flare. The
GMVA data allow us to study this outburst with unprecedented image fidelity at
highest (sub-parsec) resolution. On these scales, the outburst is resolved into
a complex series of plasma components forming an intriguing bent structure.
Within 1 mas from the jet base, ejections vary in position angle and components
move with an apparent velocity of ~3.7c, significantly slower than the maximum
velocity observed with cm-VLBI on scales beyond 1 mas.


title:
Coherent absorption and enhanced photoluminescence in thin layers of
  nanorods

abstract:
  We demonstrate a large light absorptance (80%) in a nanometric layer of
quantum dots in rods (QRs) with a thickness of 23 nm. This behavior is
explained in terms of the coherent absorption by interference of the light
incident at a certain angle onto the very thin QR layer. We exploit this
coherent light absorption to enhance the photoluminescent emission from the
QRs. Up to a seven- and fivefold enhancement of the photoluminescence is
observed for p- and s-polarized incident light, respectively.


title: Lagrangian fibrations of holomorphic-symplectic varieties of K3^[n]-type

abstract:
  Let X be a compact Kahler holomorphic-symplectic manifold, which is
deformation equivalent to the Hilbert scheme of length n subschemes of a K3
surface. Let L be a nef line-bundle on X, such that the 2n-th power of c_1(L)
vanishes and c_1(L) is primitive. Assume that the two dimensional subspace
H^{2,0}(X) + H^{0,2}(X), of the second cohomology of X with complex
coefficients, intersects trivially the integral cohomology. We prove that the
linear system of L is base point free and it induces a Lagrangian fibration on
X. In particular, the line-bundle L is effective. A determination of the
semi-group of effective divisor classes on X follows, when X is projective. For
a generic such pair (X,L), not necessarily projective, we show that X is
bimeromorphic to a Tate-Shafarevich twist of a moduli space of stable torsion
sheaves, each with pure one dimensional support, on a projective K3 surface.


title: Can local particle filters beat the curse of dimensionality?

abstract:
  The discovery of particle filtering methods has enabled the use of nonlinear
filtering in a wide array of applications. Unfortunately, the approximation
error of particle filters typically grows exponentially in the dimension of the
underlying model. This phenomenon has rendered particle filters of limited use
in complex data assimilation problems. In this paper, we argue that it is often
possible, at least in principle, to develop local particle filtering algorithms
whose approximation error is dimension-free. The key to such developments is
the decay of correlations property, which is a spatial counterpart of the much
better understood stability property of nonlinear filters. For the simplest
possible algorithm of this type, our results provide under suitable assumptions
an approximation error bound that is uniform both in time and in the model
dimension. More broadly, our results provide a framework for the investigation
of filtering problems and algorithms in high dimension.


title:
The parameter derivatives
  $[\partial^{2}P_{\nu}(z)/\partial\nu^{2}]_{\nu=0}$ and
  $[\partial^{3}P_{\nu}(z)/\partial\nu^{3}]_{\nu=0}$, where $P_{\nu}(z)$ is the
  Legendre function of the first kind

abstract:
  We derive explicit expressions for the parameter derivatives
$[\partial^{2}P_{\nu}(z)/\partial\nu^{2}]_{\nu=0}$ and
$[\partial^{3}P_{\nu}(z)/\partial\nu^{3}]_{\nu=0}$, where $P_{\nu}(z)$ is the
Legendre function of the first kind. It is found that {displaymath}
\frac{\partial^{2}P_{\nu}(z)}{\partial\nu^{2}}\bigg|_{\nu=0}
=-2\Li_{2}\frac{1-z}{2}, {displaymath} where $\Li_{2}z$ is the dilogarithm
(this formula has been recently arrived at by Schramkowski using
\emph{Mathematica}), and that {displaymath}
\frac{\partial^{3}P_{\nu}(z)}{\partial\nu^{3}}\bigg|_{\nu=0}
=12\Li_{3}\frac{z+1}{2}-6\ln\frac{z+1}{2}\Li_{2}\frac{z+1}{2}
-\pi^{2}\ln\frac{z+1}{2}-12\zeta(3), {displaymath} where $\Li_{3}z$ is the
polylogarithm of order 3 and $\zeta(s)$ is the Riemann zeta function.


title:
Information Theoretic Cut-set Bounds on the Capacity of Poisson Wireless
  Networks

abstract:
  This paper presents a stochastic geometry model for the investigation of
fundamental information theoretic limitations in wireless networks. We derive a
new unified multi-parameter cut-set bound on the capacity of networks of
arbitrary Poisson node density, size, power and bandwidth, under fast fading in
a rich scattering environment. In other words, we upper-bound the optimal
performance in terms of total communication rate, under any scheme, that can be
achieved between a subset of network nodes (defined by the cut) with all the
remaining nodes. Additionally, we identify four different operating regimes,
depending on the magnitude of the long-range and short-range signal to noise
ratios. Thus, we confirm previously known scaling laws (e.g., in bandwidth
and/or power limited wireless networks), and we extend them with specific
bounds. Finally, we use our results to provide specific numerical examples.


title:
Tradeoffs for reliable quantum information storage in surface codes and
  color codes

abstract:
  The family of hyperbolic surface codes is one of the rare families of quantum
LDPC codes with non-zero rate and unbounded minimum distance. First, we
introduce a family of hyperbolic color codes. This produces a new family of
quantum LDPC codes with non-zero rate and with minimum distance logarithmic in
the blocklength. Second, we study the tradeoff between the length n, the number
of encoded qubits k and the distance d of surface codes and color codes. We
prove that kd^2 is upper bounded by C(log k)^2n, where C is a constant that
depends only on the row weight of the parity-check matrix. Our results prove
that the best asymptotic minimum distance of LDPC surface codes and color codes
with non-zero rate is logarithmic in the length.


title: Energy-Efficient Communication in the Presence of Synchronization Errors

abstract:
  Communication systems are traditionally designed to have tight
transmitter-receiver synchronization. This requirement has negligible overhead
in the high-SNR regime. However, in many applications, such as wireless sensor
networks, communication needs to happen primarily in the energy-efficient
regime of low SNR, where requiring tight synchronization can be highly
suboptimal.
  In this paper, we model the noisy channel with synchronization errors as an
insertion/deletion/substitution channel. For this channel, we propose a new
communication scheme that requires only loose transmitter-receiver
synchronization. We show that the proposed scheme is asymptotically optimal for
the Gaussian channel with synchronization errors in terms of energy efficiency
as measured by the rate per unit energy. In the process, we also establish that
the lack of synchronization causes negligible loss in energy efficiency. We
further show that, for a general discrete memoryless channel with
synchronization errors and a general input cost function admitting a zero-cost
symbol, the rate per unit cost achieved by the proposed scheme is within a
factor two of the information-theoretic optimum.


title:
Vortex liquid in magnetic-field-induced superconducting vacuum of
  quenched lattice QCD

abstract:
  In the background of the strong magnetic field the vacuum is suggested to
possess an electromagnetically superconducting phase characterised by the
emergence of inhomogeneous quark-antiquark vector condensates which carry
quantum numbers of the charged rho mesons. The rho-meson condensates are
inhomogeneous due to the presence of the stringlike defects ("the rho
vortices") which are parallel to the magnetic field (the superconducting vacuum
phase is similar to the mixed Abrikosov phase of a type-II superconductor). In
agreement with these expectations, we have observed the presence of the rho
vortices in numerical simulations of the vacuum of the quenched two-color
lattice QCD in strong magnetic field background. We have found that in the
quenched QCD the rho vortices form a liquid. The transition between the usual
(insulator) phase at low B and the superconducting vortex liquid phase at high
B turns out to be very smooth, at least in the quenched QCD.


title: PDF articles metadata harvester

abstract:
  Scientific journals are very important in recording the finding from
researchers around the world. The recent media to disseminate scientific
journals is PDF. On scheme to find the scientific journals over the internet is
via metadata. Metadata stores information about article summary. Embedding
metadata into PDF of scientific article will grant the consistency of metadata
readness. Harvesting the metadata from scientific journal is very interesting
field at the moment. This paper will discuss about scientific journal metadata
harvesters involving XMP.


title: A thermokinetic approach to radiative heat transfer at the nanoscale

abstract:
  Radiative heat exchange at the nanoscale presents a challenge for several
areas due to its scope and nature. Here, we provide a thermokinetic description
of microscale radiative energy transfer including phonon-photon coupling
manifested through a non-Debye relaxation behavior. We show that a
lognormal-like distribution of modes of relaxation accounts for this non-Debye
relaxation behavior leading to the thermal conductance. We also discuss the
validity of the fluctuation-dissipation theorem. The general expression for the
thermal conductance we obtain fits existing experimental results with
remarkable accuracy. Accordingly, our approach offers an overall explanation of
radiative energy transfer through micrometric gaps regardless of geometrical
configurations and distances.


title:
Velocity measurements in the near field of a diesel fuel injector by
  ultrafast imagery

abstract:
  This paper examines the velocity profile of fuel issuing from a high-pressure
single-orifice diesel injector. Velocities of liquid structures were determined
from time-resolved ultrafast shadow images, formed by an amplified two-pulse
laser source coupled to a double-frame camera. A statistical analysis of the
data over many injection events was undertaken to map velocities related to
spray formation near the nozzle outlet as a function of time after start of
injection. These results reveal a strong asymmetry in the liquid profile of the
test injector, with distinct fast and slow regions on opposite sides of the
orifice. Differences of ~100 m/s can be observed between the 'fast' and 'slow'
sides of the jet, resulting in different atomization conditions across the
spray. On average, droplets are dispersed at a greater distance from the nozzle
on the 'fast' side of the flow, and distinct macrostructure can be observed
under the asymmetric velocity conditions. The changes in structural velocity
and atomization behavior resemble flow structures which are often observed in
the presence of string cavitation produced under controlled conditions in
scaled, transparent test nozzles. These observations suggest that widely used
common-rail supply configurations and modern injectors can potentially generate
asymmetric interior flows which strongly influence diesel spray morphology. The
velocimetry measurements presented in this work represent an effective and
relatively straightforward approach to identify deviant flow behavior in real
diesel sprays, providing new spatially resolved information on fluid structure
and flow characteristics within the shear layers on the jet periphery.


title:
Output feedback stabilization for a scalar conservation law with a
  nonlocal velocity

abstract:
  In this paper, we study the output feedback stabilization for a scalar
conservation law with a nonlocal velocity, that models a highly re-entrant
manufacturing system as encountered in semi-conductor production. By spectral
analysis, we obtain a complete result on the exponential stabilization for the
linearized control system. Moreover, by using a Lyapunov function approach, we
also prove the exponential stabilization results for the nonlinear control
system in certain cases.


title: Special precovers and preenvelopes of complexes

abstract:
  The notion of an $\mathcal{L}$ complex (for a given class of $R$-modules
$\mathcal{L}$) was introduced by Gillespie: a complex $C$ is called
$\mathcal{L}$ complex if $C$ is exact and $\Z_{i}(C)$ is in $\mathcal{L}$ for
all $i\in \mathbb{Z}$. Let $\widetilde{\mathcal{L}}$ stand for the class of all
$\mathcal{L}$ complexes. In this paper, we give sufficient condition on a class
of $R$-modules such that every complex has a special
$\widetilde{\mathcal{L}}$-precover (resp.,
$\widetilde{\mathcal{L}}$-preenvelope). As applications, we obtain that every
complex has a special projective precover and a special injective preenvelope,
over a coherent ring every complex has a special FP-injective preenvelope, and
over a noetherian ring every complex has a special
$\widetilde{\mathcal{GI}}$-preenvelope, where $\mathcal{GI}$ denotes the class
of Gorenstein injective modules.


title: Alternative to the Well-known Statistical Dynamics of Linear Systems

abstract:
  The problem of determining the mathematical model of the dynamics of
multi-dimensional control systems in the presence of noise under the condition
that the correlation functions cannot be found. Known statistical dynamics of
linear systems is a more effective alternative. Background information is
presented in the form of individual implementations nonergodic stochastic
processes. Such a realization is deterministic functions. We introduce the
concept of systems of sets of signals for the components on the semiring. For
the system of sets of linearly dependent and linearly independent of the
measured signals of a certain frequency properties. Frequency method is
designed to deal with the noise on the set of deterministic functions. Example
is the determination of the dynamic characteristics of the aircraft in
accordance with the data obtained in one automatic landing.