title: Structural transitions in a doped lanthanum cuprate

abstract:
  139La NMR and relaxation measurements have been performed on
La{1.8-x}Eu{0.2}Sr{x}CuO{4} (x = 0.13 and 0.2) single crystals. The temperature
dependence of the 139La NMR spectra in all the structural phases (HTT -> LTO ->
LTT) reveals the non-vanishing tilt angle of the CuO6 octahedra in the HTT
phase, opposed to the case of La{2-x}Sr{x}CuO{4} where the tilt angle
disappears immediately above the transition. Since 139La relaxation data
provide evidence of the thermodynamic critical fluctuations associated with the
structural phase transitions, HTT -> LTO and LTO -> LTT, we conclude that the
structural transitions in Eu-doped La{2-x}Sr{x}CuO{4} should be of the
order-disorder type rather than of the displacive type observed in
La{2-x}Sr{x}CuO{4}. The change of the nature of the structural transitions
caused by doping Eu appears to be consistent with the LTO -> LTT transition
that is absent in La{2-x}Sr{x}CuO{4}.


title:
Asymptotic behavior of nonlinear Schroedinger Systems with Linear
  Coupling

abstract:
  A system of two coupled nonlinear Schroedinger equations is treated. In
addition, a linear coupling which models an external driven field described by
the Rabi frequency is considered. Asymptotics for large Rabi frequency are
carried out. Convergence in the appropriate Strichartz space is proven. As a
consequence, the global existence of the limiting system gives a criterion for
the long time behavior of the original system.


title: Bicompletions of distance matrices

abstract:
  In the practice of information extraction, the input data are usually
arranged into pattern matrices, and analyzed by the methods of linear algebra
and statistics, such as principal component analysis. In some applications, the
tacit assumptions of these methods lead to wrong results. The usual reason is
that the matrix composition of linear algebra presents information as flowing
in waves, whereas it sometimes flows in particles, which seek the shortest
paths. This wave-particle duality in computation and information processing has
been originally observed by Abramsky. In this paper we pursue a particle view
of information, formalized in *distance spaces*, which generalize metric
spaces, but are slightly less general than Lawvere's *generalized metric
spaces*. In this framework, the task of extracting the 'principal components'
from a given matrix of data boils down to a bicompletio}, in the sense of
enriched category theory. We describe the bicompletion construction for
distance matrices. The practical goal that motivates this research is to
develop a method to estimate the hardness of attack constructions in security.


title:
Differentiation in P-minimal structures and a p-adic Local Monotonicity
  Theorem

abstract:
  We prove a p-adic, local version of the Monotonicity Theorem for P-minimal
structures. The existence of such a theorem was originally conjectured by
Haskell and Macpherson. We approach the problem by considering the first order
strict derivative. In particular, we show that, for a wide class of P-minimal
structures, the definable functions f : K -> K are almost everywhere strictly
differentiable and satisfy the Local Jacobian Property.


title: A New Photometric Model of the Galactic Bar using Red Clump Giants

abstract:
  We present a study of the luminosity density distribution of the Galactic bar
using number counts of red clump giants (RCGs) from the OGLE-III survey. The
data were recently published by Nataf et al. (2013) for 9019 fields towards the
bulge and have $2.94\times 10^6$ RC stars over a viewing area of $90.25
\,\textrm{deg}^2$. The data include the number counts, mean distance modulus
($\mu$), dispersion in $\mu$ and full error matrix, from which we fit the data
with several tri-axial parametric models. We use the Markov Chain Monte Carlo
(MCMC) method to explore the parameter space and find that the best-fit model
is the $E_3$ model, with the distance to the GC is 8.13 kpc, the ratio of
semi-major and semi-minor bar axis scale lengths in the Galactic plane
$x_{0},y_{0}$, and vertical bar scale length $z_0$, is $x_0:y_0:z_0 \approx
1.00:0.43:0.40$ (close to being prolate). The scale length of the stellar
density profile along the bar's major axis is $\sim$ 0.67 kpc and has an angle
of $29.4^\circ$, slightly larger than the value obtained from a similar study
based on OGLE-II data. The number of estimated RC stars within the field of
view is $2.78 \times 10^6$, which is systematically lower than the observed
value. We subtract the smooth parametric model from the observed counts and
find that the residuals are consistent with the presence of an X-shaped
structure in the Galactic centre, the excess to the estimated mass content is
$\sim 5.8%$. We estimate the total mass of the bar is $\sim 1.8 \times 10^{10}
M_\odot$. Our results can be used as a key ingredient to construct new density
models of the Milky Way and will have implications on the predictions of the
optical depth to gravitational microlensing and the patterns of hydrodynamical
gas flow in the Milky Way.


title: On the Sharpness of Localization of Individual Events in Space and Time

abstract:
  The concept of event provides the essential bridge from the realm of
virtuality of the quantum state to real phenomena in space and time. We ask how
much we can gather from existing theory about their localization and point out
that decoherence and coarse graining -- though important -- do not suffice for
a consistent interpretation without the additional principle of random
realization.


title: Interferometric description of optical metamaterials

abstract:
  We introduce a simple theoretical model that describes the interaction of
light with optical metamaterials in terms of interfering optical plane waves.
In this model, a metamaterial is considered to consist of planar arrays of
densely packed nanoparticles. In the analysis, each such array reduces to an
infinitely thin homogeneous sheet. The transmission and reflection coefficients
of this sheet are found to be equal to those of an isolated nanoparticle array
and, therefore, they are easy to evaluate numerically for arbitrary shapes and
arrangements of the particles. The presented theory enables fast calculation of
electromagnetic fields interacting with a metamaterial slab of an arbitrary
size, which, for example, can be used to retrieve the effective refractive
index and wave impedance in the material. It is also shown to accurately
describe optically anisotropic metamaterials that in addition exhibit strong
spatial dispersion, such as bifacial metamaterials.


title: A set of generalized parton distributions

abstract:
  The information about generalized parton distributions (GPDs) extracted from
exclusive meson leptoproduction within the handbag approach is summarized.
Details are only discussed for the GPD E and the transversity ones. It is also
commented on results for deep virtual Compton scattering evaluated from these
GPDs


title: Propagation and stability of superluminal waves in pulsar winds

abstract:
  Nonlinear electromagnetic waves with superluminal phase velocity can
propagate in the winds around isolated pulsars, and around some pulsars in
binary systems. Using a short-wavelength approximation, we find and analyze an
integrable system of equations that govern their evolution in spherical
geometry. A confined mode is identified that stagnates to finite pressure at
large radius and can form a precursor to the termination shock. Using a
simplified criterion, we find this mode is stable for most isolated pulsars,
but may be unstable if the external pressure is high, such as in the pulsar
wind nebulae in starburst galaxies and in W44. Pulsar winds in eccentric binary
systems, such as PSR 1259-63, may go through phases with stable and unstable
electromagnetic precursors, as well as phases in which the density is too high
for these modes to propagate.


title:
A theory for the emergence of coherent structures in beta-plane
  turbulence

abstract:
  Planetary turbulent flows are observed to self-organize into large scale
structures such as zonal jets and coherent vortices. One of the simplest models
of planetary turbulence is obtained by considering a barotropic flow on a
beta-plane channel with turbulence sustained by random stirring. Non-linear
integrations of this model show that as the energy input rate of the forcing is
increased, the homogeneity of the flow is broken with the emergence of
non-zonal, coherent, westward propagating structures and at larger energy input
rates by the emergence of zonal jets. We study the emergence of non-zonal
coherent structures using a non-equilibrium statistical theory, Stochastic
Structural Stability Theory (S3T, previously referred to as SSST). S3T directly
models a second order approximation to the statistical mean turbulent state and
allows identification of statistical turbulent equilibria and study of their
stability. Using S3T, the bifurcation properties of the homogeneous state in
barotropic beta-plane turbulence are determined. Analytic expressions for the
zonal and non-zonal large scale coherent flows that emerge as a result of
structural instability are obtained. Through numerical integrations of the S3T
dynamical system, it is found that the unstable structures equilibrate at
finite amplitude. Numerical simulations of the nonlinear equations confirm the
characteristics (scale, amplitude and phase speed) of the structures predicted
by S3T.


title: Nanostructured and Modulated Low-Dimensional Systems

abstract:
  Charge density wave (CDW) ordering in NbSe3 and the structurally related
quasi one-dimensional compounds is reconsidered. Since the modulated ground
state is characterized by unstable nano-domains, the structural information
obtained from diffraction experiments is to be supplemented by some additional
information from a method, able to reveal details on a unit cell level.
Low-temperature (LT) scanning tunneling microscopy (STM) can resolve both, the
local atomic structure and the superimposed charge density modulation. It is
shown that the established model for NbSe3 with two incommensurate (IC) modes,
q1 = (0,0.241,0) and q2 = (0.5,0.260,0.5), locked in at T1=144K and T2=59K and
separately confined to two of the three available types of bi-capped trigonal
prismatic (BCTP) columns, must be modified. The alternative explanation is
based on the existence of modulated layered nano-domains and is in good accord
with the available LT STM results. These confirm i.a. the presence of both IC
modes above the lower CDW transition temperature. Two BCTP columns, belonging
to a symmetry-related pair, are as a rule alternatively modulated by the two
modes. Such pairs of columns are ordered into unstable layered nano-domains,
whose q1 and q2 sub-layers are easily interchanged. The mutually
interchangeable sections of the two unstable IC modes keep a temperature
dependent long-range ordering. Both modes can formally be replaced by a single
highly inharmonic long-period commensurate CDW.


title: New Inapproximability Bounds for TSP

abstract:
  In this paper, we study the approximability of the metric Traveling Salesman
Problem (TSP) and prove new explicit inapproximability bounds for that problem.
The best up to now known hardness of approximation bounds were 185/184 for the
symmetric case (due to Lampis) and 117/116 for the asymmetric case (due to
Papadimitriou and Vempala). We construct here two new bounded occurrence CSP
reductions which improve these bounds to 123/122 and 75/74, respectively. The
latter bound is the first improvement in more than a decade for the case of the
asymmetric TSP. One of our main tools, which may be of independent interest, is
a new construction of a bounded degree wheel amplifier used in the proof of our
results.


title: Review of the EFT treatment of quarkonium at finite temperature

abstract:
  Heavy quarkonium is one of the most investigated probes of the medium
produced in heavy-ion collisions. In the past few years progress has been made
in the description of its in-medium dynamics from QCD. Non-relativistic EFTs in
particular allow one to define and compute rigorously the potential governing
the real-time evolution of the bound state from QCD, showing that it is
composed of a real and an imaginary part. The latter encodes the effect of
scattering with the light constituents of the plasma and is oftentimes
responsible for the dissociation of the bound state. The EFT approach and its
main results, as well as comparisons with recent lattice data and
phenomenological applications, are briefly reviewed here.


title: Accurate Complex Scaling of Three Dimensional Numerical Potentials

abstract:
  The complex scaling method, which consists in continuing spatial coordinates
into the complex plane, is a well-established method that allows to compute
resonant eigenfunctions of the time-independent Schroedinger operator. Whenever
it is desirable to apply the complex scaling to investigate resonances in
physical systems defined on numerical discrete grids, the most direct approach
relies on the application of a similarity transformation to the original,
unscaled Hamiltonian. We show that such an approach can be conveniently
implemented in the Daubechies wavelet basis set, featuring a very promising
level of generality, high accuracy, and no need for artificial convergence
parameters. Complex scaling of three dimensional numerical potentials can be
efficiently and accurately performed. By carrying out an illustrative resonant
state computation in the case of a one-dimensional model potential, we then
show that our wavelet-based approach may disclose new exciting opportunities in
the field of computational non-Hermitian quantum mechanics.


title: A new intermolecular mechanism to selectively drive photoinduced damages

abstract:
  Low-energy electrons (LEEs) are known to be effective in causing strand
breaks in DNA. Recent experiments show that an important direct source of LEEs
is the intermolecular Coulombic decay (ICD) process. Here we propose a new
cascade mechanism initiated by core excitation and terminated by ICD and
demonstrate its properties. Explicit calculations show that the energies of the
emitted ICD-electrons can be controlled by selecting the initial atomic
excitation. The properties of the cascade may have interesting applications in
the fields of electron spectroscopy and radiation damage. Initiating such a
cascade by resonant X-ray absorption from a high-Z element embedded in a
cancerous cell nucleus, ICD will deliver genotoxic particles \textit{locally}
at the absorption site, increasing in that way the controllability of the
induced damage.


title:
Self-trapping of Fermi and Bose gases under spatially modulated
  repulsive nonlinearity and transverse confinement

abstract:
  We show that self-localized ground states can be created in the spin-balanced
gas of fermions with repulsion between the spin components, whose strength
grows from the center to periphery, in combination with the harmonic-oscillator
(HO) trapping potential acting in one or two transverse directions. We also
consider the ground state in the non-interacting Fermi gas under the action of
the spatially growing tightness of the one- or two-dimensional (1D or 2D) HO
confinement. These settings are considered in the framework of the
Thomas-Fermi-von Weizsacker (TF-vW) density functional. It is found that the vW
correction to the simple TF approximation (the gradient term) is nearly
negligible in all situations. The properties of the ground state under the
action of the 2D and 1D HO confinement with the tightness growing in the
transverse directions is investigated too for the Bose-Einstein condensate
(BEC) with the self-repulsive nonlinearity.


title:
Statistical Properties of Brown Dwarf Companions: Implications for
  Different Formation Mechanisms

abstract:
  The mass domain where massive extrasolar planets and brown dwarfs overlap is
still poorly understood due to the paucity of brown dwarfs orbiting close to
solar-type stars, the so-called brown dwarf desert. In this paper we collect
all of available data about close brown dwarfs around solar type stars and
their host stars from literature and study the demographics of the brown dwarf
desert. The data clearly show a short period and a medium mass gap in the brown
dwarf period-mass distribution diagram ($ 35<m\sin i<55 M_{\rm Jup}$ and
$P<100$ days), representing the "driest land" in the brown dwarf desert.
Observation biases are highly unlikely to cause this gap due to its short
period and medium mass, of which brown dwarfs can be easily detected by
previous RV surveys. Brown dwarfs above and below this gap have significantly
different eccentricity distribution, which not only confirms that this gap is
real, but also implies that they may have different origins. Our further
statistical study indicates that brown dwarfs below this gap may primarily form
in the protoplanetary disk through disk gravitational instability, while brown
dwarfs above this gap may dominantly form like a stellar binary through
molecular cloud fragmentation. Our discoveries have offered important insights
about brown dwarf formation mechanisms and their possible relationships with
planet and star formation.


title: Quantum corrections to conductivity in Si doped ZnO thin films

abstract:
  Si doped ZnO thin films with Si concentrations ranging from 0.4 to 10 % have
been grown by sequential pulsed laser deposition on sapphire substrates. The
resistivity of the films first decreased from ~ 6.6x10-3 to 4.7x10-4 ohm-cm as
the Si concentration was increased from ~ 0.4 to 2% and then it increased with
further increase in Si concentration. The electron concentrations in the films
were in the range from 3x1019 to 4x1020 cm-3 showing their degenerate nature.
However, temperature dependent resistivity measurements in the range from 300
to 4.2 K revealed negative temperature coefficient of resistivity (TCR) for the
0.4, 6 and 10% Si doped ZnO films in the entire measurement temperature range.
The 0.6, 0.9 and 2% Si doped films showed a transition from negative to
positive TCR with increasing temperature. The negative magnetoresistance found
in the films at low temperatures and 0.5 T magnetic field pointed to weak
localization as the dominant contributor towards negative TCR. A quantitative
fit of the temperature dependent resistivity data for all the films could be
obtained by considering the quantum correction to conductivity arising due to
disorder induced weak localization effect.


title: Virial Expansion Bounds

abstract:
  In the 1960s, the technique of using cluster expansion bounds in order to
achieve bounds on the virial expansion was developed by Lebowitz and Penrose
(1964) and Ruelle (1969). This technique is generalised to more recent cluster
expansion bounds by Poghosyan and Ueltschi (2009), which are related to the
work of Procacci (2007) and the tree-graph identity, detailed by Brydges
(1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by
doing the actual optimisation and achieving expressions in terms of the Lambert
W-function. The different bound from the cluster expansion shows some
improvements for bounds on the convergence of the virial expansion in the case
of positive potentials, which are allowed to have a hard core.


title:
An optimization approach for the localization of defects in an
  inhomogeneous medium from acoustic far-field measurements at a fixed
  frequency

abstract:
  We are interested in the localization of defects in non-absorbing
inhomogeneous media with far-field measurements generated by plane waves. In
localization problems, most so-called sampling methods are based on a
characterization involving point-sources and the range of some implicitly
defined operator. We present here a way to deal with this implicit operator by
the means of an optimization approach in the lines of the well-known inf
criterion for the factorization method.


title:
A diffuse interface model for two-phase incompressible flows with
  nonlocal interactions and nonconstant mobility

abstract:
  We consider a diffuse interface model for incompressible isothermal mixtures
of two immiscible fluids with matched constant densities. This model consists
of the Navier-Stokes system coupled with a convective nonlocal Cahn-Hilliard
equation with non-constant mobility. We first prove the existence of a global
weak solution in the case of non-degenerate mobilities and regular potentials
of polynomial growth. Then we extend the result to degenerate mobilities and
singular (e.g. logarithmic) potentials. In the latter case we also establish
the existence of the global attractor in dimension two. Using a similar
technique, we show that there is a global attractor for the convective nonlocal
Cahn-Hilliard equation with degenerate mobility and singular potential in
dimension three.


title: Statistical inference for Sobol pick freeze Monte Carlo method

abstract:
  Many mathematical models involve input parameters, which are not precisely
known. Global sensitivity analysis aims to identify the parameters whose
uncertainty has the largest impact on the variability of a quantity of interest
(output of the model). One of the statistical tools used to quantify the
influence of each input variable on the output is the Sobol sensitivity index.
We consider the statistical estimation of this index from a finite sample of
model outputs. We study asymptotic and non-asymptotic properties of two
estimators of Sobol indices. These properties are applied to significance tests
and estimation by confidence intervals.


title: Make your Boy surface

abstract:
  This is an introductory article about the Boy surface. Boy found 1901 that
$\mathbb{R}P^2$ can be immersed into $\mathbb{R}^3$, and published it. (The
image of) the immersion is called the Boy surface after Boy's discovery. We
have created a way to construct the Boy surface by using a pair of scissors, a
piece of paper, and a strip of scotch tape. In this article we introduce the
way. Furthermore, we make a movie to show the paper-craft actually, and put it
in a website. One can find the website by typing in the author's name or the
title of this article in the search engine.


title:
Dirichlet Heat Kernel Estimates for Rotationally Symmetric L\'evy
  processes

abstract:
  In this paper, we consider a large class of purely discontinuous rotationally
symmetric Levy processes. We establish sharp two-sided estimates for the
transition densities of such processes killed upon leaving an open set D. When
D is a \kappa-fat open set, the sharp two-sided estimates are given in terms of
surviving probabilities and the global transition density of the Levy process.
When D is a C^{1, 1} open set and the Levy exponent of the process is given by
\Psi(\xi)= \phi(|\xi|^2) with \phi being a complete Bernstein function
satisfying a mild growth condition at infinity, our two-sided estimates are
explicit in terms of \Psi, the distance function to the boundary of D and the
jumping kernel of X, which give an affirmative answer to the conjecture posted
in [Potential Anal., 36 (2012) 235-261]. Our results are the first sharp
two-sided Dirichlet heat kernel estimates for a large class of symmetric Levy
processes with general Levy exponents. We also derive an explicit lower bound
estimate for symmetric Levy processes on R^d in terms of their Levy exponents.


title:
A non-symmetric Yang-Baxter algebra for the quantum nonlinear
  Schr\"odinger model (PhD Thesis)

abstract:
  We study certain non-symmetric wavefunctions associated to the quantum
nonlinear Schr\"odinger (QNLS) model, introduced by Komori and Hikami using
representations of the degenerate affine Hecke algebra. In particular, they can
be generated using a vertex operator formalism analogous to the recursion that
defines the symmetric QNLS wavefunction in the quantum inverse scattering
method. Furthermore, some of the commutation relations encoded in the
Yang-Baxter equation are generalized to the non-symmetric case.


title: Asymptotic normality and efficiency of two Sobol index estimators

abstract:
  Many mathematical models involve input parameters, which are not precisely
known. Global sensitivity analysis aims to identify the parameters whose
uncertainty has the largest impact on the variability of a quantity of interest
(output of the model). One of the statistical tools used to quantify the
influence of each input variable on the output is the Sobol sensitivity index.
We consider the statistical estimation of this index from a finite sample of
model outputs: we present two estimators and state a central limit theorem for
each. We show that one of these estimators has an optimal asymptotic variance.
We also generalize our results to the case where the true output is not
observable, and is replaced by a noisy version.


title:
Increasing processes and the change of variables formula for
  non-decreasing functions

abstract:
  Given an increasing process $(A_t)_{t\geq 0}$, we characterize the
right-continuous non-decreasing functions $f: \R_+\to \R_+$ that map $A$ to a
pure-jump process. As an example of application, we show for instance that
functions with bounded variations belong to the domain of the extended
generator of any subordinators with no drift and infinite L\'evy measure.


title: Feasible combinatorial matrix theory

abstract:
  We show that the well-known Konig's Min-Max Theorem (KMM), a fundamental
result in combinatorial matrix theory, can be proven in the first order theory
$\LA$ with induction restricted to $\Sigma_1^B$ formulas. This is an
improvement over the standard textbook proof of KMM which requires $\Pi_2^B$
induction, and hence does not yield feasible proofs --- while our new approach
does. $\LA$ is a weak theory that essentially captures the ring properties of
matrices; however, equipped with $\Sigma_1^B$ induction $\LA$ is capable of
proving KMM, and a host of other combinatorial properties such as Menger's,
Hall's and Dilworth's Theorems. Therefore, our result formalizes Min-Max type
of reasoning within a feasible framework.


title: Partial Transfer Entropy on Rank Vectors

abstract:
  For the evaluation of information flow in bivariate time series, information
measures have been employed, such as the transfer entropy (TE), the symbolic
transfer entropy (STE), defined similarly to TE but on the ranks of the
components of the reconstructed vectors, and the transfer entropy on rank
vectors (TERV), similar to STE but forming the ranks for the future samples of
the response system with regard to the current reconstructed vector. Here we
extend TERV for multivariate time series, and account for the presence of
confounding variables, called partial transfer entropy on ranks (PTERV). We
investigate the asymptotic properties of PTERV, and also partial STE (PSTE),
construct parametric significance tests under approximations with Gaussian and
gamma null distributions, and show that the parametric tests cannot achieve the
power of the randomization test using time-shifted surrogates. Using
simulations on known coupled dynamical systems and applying parametric and
randomization significance tests, we show that PTERV performs better than PSTE
but worse than the partial transfer entropy (PTE). However, PTERV, unlike PTE,
is robust to the presence of drifts in the time series and it is also not
affected by the level of detrending.

categories: stat.ME cs.IT math.IT nlin.CD physics.data-an


title: Performance Evaluation of Edge-Directed Interpolation Methods for Images

abstract:
  Many interpolation methods have been developed for high visual quality, but
fail for inability to preserve image structures. Edges carry heavy structural
information for detection, determination and classification. Edge-adaptive
interpolation approaches become a center of focus. In this paper, performance
of four edge-directed interpolation methods comparing with two traditional
methods is evaluated on two groups of images. These methods include new
edge-directed interpolation (NEDI), edge-guided image interpolation (EGII),
iterative curvature-based interpolation (ICBI), directional cubic convolution
interpolation (DCCI) and two traditional approaches, bi-linear and bi-cubic.
Meanwhile, no parameters are mentioned to measure edge-preserving ability of
edge-adaptive interpolation approaches and we proposed two. One evaluates
accuracy and the other measures robustness of edge-preservation ability.
Performance evaluation is based on six parameters. Objective assessment and
visual analysis are illustrated and conclusions are drawn from theoretical
backgrounds and practical results.


title: $L^2$-Alexander invariant for knots

abstract:
  This paper deals with the study of a new family of knot invariants: the
$L^2$-Alexander invariant. A main result is to give a method of computation of
the $L^2$-Alexander invariant of a knot complement using any presentation of
default 1 of the knot group.


title: Differential Characters and Geometric Chains

abstract:
  We study Cheeger-Simons differential characters and provide geometric
descriptions of the ring structure and of the fiber integration map. The
uniqueness of differential cohomology (up to unique natural transformation) is
proved by deriving an explicit formula for any natural transformation between a
differential cohomology theory and the model given by differential characters.
Fiber integration for fibers with boundary is treated in the context of
relative differential characters. As applications we treat higher-dimensional
holonomy, parallel transport, and transgression.


title:
Current-driven domain wall motion with spin Hall effect: Reduction of
  threshold current density

abstract:
  We theoretically study the current-driven domain wall motion in the presence
of both the spin Hall effect and an extrinsic pinning potential. The spin Hall
effect mainly affects the damping ratio of the domain wall precession in the
pinning potential. When the pinning potential is not too strong, this results
in a significant reduction of a threshold current density for the depinning of
a domain wall with certain polarity. We also propose one way to distinguish the
spin Hall effect induced spin-transfer torque from the one induced by the
Rashba spin-orbit coupling experimentally.


title:
Study of the electronic nematic phase of Sr$_3$Ru$_2$O$_7$ with precise
  control of the applied magnetic field vector

abstract:
  We report a study of the magnetoresistivity of high purity Sr$_3$Ru$_2$O$_7$,
in the vicinity of its electronic nematic phase. By employing a triple-axis
(9/1/1T) vector magnet, we were able to precisely tune both the magnitude and
direction of the in-plane component of the magnetic field (H$_\parallel$). We
report the dependence of the resistively determined anisotropy on H$_\parallel$
in the phase, as well as across the wider temperature-field region. Our
measurements reveal a high-temperature anisotropy which mimics the behaviour of
fluctuations from the underlying quantum critical point, and suggest the
existence of a more complicated phase diagram than previously reported.


title:
Social and place-focused communities in location-based online social
  networks

abstract:
  Thanks to widely available, cheap Internet access and the ubiquity of
smartphones, millions of people around the world now use online location-based
social networking services. Understanding the structural properties of these
systems and their dependence upon users' habits and mobility has many potential
applications, including resource recommendation and link prediction. Here, we
construct and characterise social and place-focused graphs by using
longitudinal information about declared social relationships and about users'
visits to physical places collected from a popular online location-based social
service. We show that although the social and place-focused graphs are
constructed from the same data set, they have quite different structural
properties. We find that the social and location-focused graphs have different
global and meso-scale structure, and in particular that social and
place-focused communities have negligible overlap. Consequently, group
inference based on community detection performed on the social graph alone
fails to isolate place-focused groups, even though these do exist in the
network. By studying the evolution of tie structure within communities, we show
that the time period over which location data are aggregated has a substantial
impact on the stability of place-focused communities, and that information
about place-based groups may be more useful for user-centric applications than
that obtained from the analysis of social communities alone.


title: On periodic orbits in cotangent bundles of non-compact manifolds

abstract:
  This paper is concerned with the existence of periodic orbits on energy
hypersurfaces in cotangent bundles of Riemannian manifolds defined by
mechanical Hamiltonians. In \cite{bpv} it was proved that, provided certain
geometric assumptions are satisfied, regular mechanical hypersurfaces in
$\mathbb{R}^{2n}$, in particular non-compact ones, contain periodic orbits if
one homology group among the top half does not vanish. In the present paper we
extend the above mentioned existence result to a class of hypersurfaces in
cotangent bundles of Riemannian manifolds with flat ends.


title:
Microscopic formulation of non-local electrostatics in polar liquids
  embedding polarizable ions

abstract:
  Non-local electrostatic interactions associated with the finite solvent size
and ion polarizability are investigated within the mean-field linear response
theory. To this end, we introduce a field theoretic model of a polar liquid
composed of linear multipole solvent molecules and embedding polarizable ions
modeled as Drude oscillators. Unlike previous dipolar Poisson-Boltzmann
formulations treating the solvent molecules as point dipoles, our model is able
to qualitatively reproduce the non-local dielectric response behavior of polar
liquids observed in Molecular Dynamics simulations and Atomic Force Microscope
experiments for water solvent at charged interfaces. The present theory
explains the formation of the associated interfacial hydration layers in terms
of a cooperative dipolar response mechanism driven by the reaction of the
solvent molecules to their own polarization field. We also incorporate into the
theory the relative multipole/dipole moments of water molecules obtained from
quantum mechanical calculations, and show that the multipolar contributions to
the dielectric permittivity are largely dominated by the dipolar one. We find
that this stems from the mutual cancellation of the first two interfacial
hydration layers of opposite net charge for multipolar liquids. Within the same
non-local dielectric response theory, we show that the induced ion
polarizability reverses the interfacial ion density trends predicted by the
Poisson-Boltzmann theory, resulting in a surface affinity of coions and
exclusion of counterions. The results indicate that the consideration of the
discrete charge composition of solvent molecules and ions is the key step
towards a microscopic understanding of non-local electrostatic effects in polar
solvents.


title: Diffusion of relativistic gas mixtures in gravitational fields

abstract:
  A mixture of relativistic gases of non-disparate rest masses in a
Schwarzschild metric is studied on the basis of a relativistic Boltzmann
equation in the presence of gravitational fields. A BGK-type model equation of
the collision operator of the Boltzmann equation is used in order to compute
the non-equilibrium distribution functions by the Chapman-Enskog method. The
main focus of this work is to obtain Fick's law without the thermal-diffusion
cross-effect. Fick's law has four contributions, two of them are the usual
terms proportional to the gradients of concentration and pressure. The other
two are of the same nature as those which appears in Fourier's law in the
presence of gravitational fields and are related with an acceleration and
gravitational potential gradient, but unlike Fourier's law these two last terms
are of non-relativistic order. Furthermore, it is shown that the coefficients
of diffusion depend on the gravitational potential and they become larger than
those in the absence of it.


title: Three little pieces for computer and relativity

abstract:
  Numerical relativity has made big strides over the last decade. A number of
problems that have plagued the field for years have now been mostly solved.
This progress has transformed numerical relativity into a powerful tool to
explore fundamental problems in physics and astrophysics, and I present here
three representative examples. These "three little pieces" reflect a personal
choice and describe work that I am particularly familiar with. However, many
more examples could be made.


title: Higgs boson mass in NMSSM with right-handed neutrino

abstract:
  In order to have massive neutrinos, the right-handed neutrino/sneutrino
superfield ($N$) need to be introduced in supersymmetry. In the framework of
NMSSM (the MSSM with a singlet $S$) such an extension will dynamically lead to
a TeV-scale Majorana mass for the right-handed neutrino through the $SNN$
coupling when $S$ develops a vev (the free Majorana mass term is forbidden by
the assumed $Z_3$ symmetry). Also, through the couplings $SNN$ and $SH_uH_d$,
the SM-like Higgs boson (a mixture of $H_u$, $H_d$ and $S$) can naturally
couple with the right-handed neutrino/sneutrino. As a result, the TeV-scale
right-handed neutrino/sneutrino may significantly contribute to the Higgs boson
mass. Through an explicit calculation, we find that the Higgs boson mass can
indeed be sizably altered by the right-handed neutrino/sneutrino. Such new
contribution can help to push up the SM-like Higgs boson mass and thus make the
NMSSM more natural.


title: Testing Un-Separated Hypotheses by Estimating a Distance

abstract:
  In this paper we propose a Bayesian answer to testing problems when the
hypotheses are not well separated. The idea of the method is to study the
posterior distribution of a discrepancy measure between the parameter and the
model we want to test for. This is shown to be equivalent to a modification of
the testing loss. An advantage of this approach is that it can easily be
adapted to complex hypotheses testing which are in general difficult to test
for. Asymptotic properties of the test can be derived from the asymptotic
behaviour of the posterior distribution of the discrepancy measure, and gives
insight on possible calibrations. In addition one can derive separation rates
for testing, which ensure the asymptotic frequentist optimality of our
procedures.


title:
Slow modulations of periodic waves in Hamiltonian PDEs, with application
  to capillary fluids

abstract:
  Since its elaboration by Whitham, almost fifty years ago, modulation theory
has been known to be closely related to the stability of periodic traveling
waves. However, it is only recently that this relationship has been elucidated,
and that fully nonlinear results have been obtained. These only concern
dissipative systems though: reaction-diffusion systems were first considered by
Doelman, Sandstede, Scheel, and Schneider [Mem. Amer. Math. Soc. 2009], and
viscous systems of conservation laws have been addressed by Johnson, Noble,
Rodrigues, and Zumbrun [preprint 2012]. Here, only nondissipative models are
considered, and a most basic question is investigated, namely the expected link
between the hyperbolicity of modulated equations and the spectral stability of
periodic traveling waves to sideband perturbations. This is done first in an
abstract Hamiltonian framework, which encompasses a number of dispersive
models, in particular the well-known (generalized) Korteweg--de Vries equation,
and the less known Euler--Korteweg system, in both Eulerian coordinates and
Lagrangian coordinates. The latter is itself an abstract framework for several
models arising in water waves theory, superfluidity, and quantum hydrodynamics.
As regards its application to compressible capillary fluids, attention is paid
here to untangle the interplay between traveling waves/modulation equations in
Eulerian coordinates and those in Lagrangian coordinates. In the most general
setting, it is proved that the hyperbolicity of modulated equations is indeed
necessary for the spectral stability of periodic traveling waves. This extends
earlier results by Serre [Comm. Partial Differential Equations 2005], Oh and
Zumbrun [Arch. Ration. Mech. Anal. 2003], and Johnson, Zumbrun and Bronski
[Phys. D 2010]. In addition, reduced necessary conditions are obtained in the
small amplitude limit. Then numerical investigations are carried out for the
modulated equations of the Euler--Korteweg system with two types of 'pressure'
laws, namely the quadratic law of shallow water equations, and the nonmonotone
van der Waals pressure law. Both the evolutionarity and the hyperbolicity of
the modulated equations are tested, and regions of modulational instability are
thus exhibited.


title:
Topological effective field theories for Dirac fermions from index
  theorem

abstract:
  Dirac fermions have a central role in high energy physics but it is well
known that they emerge also as quasiparticles in several condensed matter
systems supporting topological order. We present a general method for deriving
the topological effective actions of (3+1) massless Dirac fermions living on
general backgrounds and coupled with vector and axial-vector gauge fields. The
first step of our strategy is standard (in the Hermitian case) and consists in
connecting the determinants of Dirac operators with the corresponding
analytical indices through the zeta-function regularization. Then, we introduce
a suitable splitting of the heat kernel that naturally selects the purely
topological part of the determinant (i.e. the topological effective action).
This topological effective action is expressed in terms of gauge fields using
the Atiyah-Singer index theorem which computes the analytical index in
topological terms. The main new result of this paper is to provide a consistent
extension of this method to the non Hermitian case where a well-defined
determinant does not exist. Quantum systems supporting relativistic fermions
can thus be topologically classified on the basis of their response to the
presence of (external or emergent) gauge fields through the corresponding
topological effective field theories.


title:
Convex computation of the maximum controlled invariant set for
  polynomial control systems

abstract:
  We characterize the maximum controlled invariant (MCI) set for discrete- as
well as continuous-time nonlinear dynamical systems as the solution of an
infinite-dimensional linear programming problem. For systems with polynomial
dynamics and compact semialgebraic state and control constraints, we describe a
hierarchy of finite-dimensional linear matrix inequality (LMI) relaxations
whose optimal values converge to the volume of the MCI set; dual to these LMI
relaxations are sum-of-squares (SOS) problems providing a converging sequence
of outer approximations to the MCI set. The approach is simple and readily
applicable in the sense that the approximations are the outcome of a single
semidefinite program with no additional input apart from the problem
description. A number of numerical examples illustrate the approach.


title: Deformations of polarizations of powers of the maximal ideal

abstract:
  In this paper, we study the two natural polarizations, namely the standard
polarization and the box polarization, of the d-th power of the maximal ideal
in a polynomial ring. We show that these polarizations correspond to smooth
points in the Hilbert scheme, and we calculate the dimension of their component
which shows that they lie on different components. When d=2, we show that all
maximal polarizations are smooth points, and we give a simple method for
calculating the dimension of their component.


title:
A unified approach to structural limits, and limits of graphs with
  bounded tree-depth

abstract:
  In this paper we introduce a general framework for the study of limits of
relational structures in general and graphs in particular, which is based on a
combination of model theory and (functional) analysis. We show how the various
approaches to graph limits fit to this framework and that they naturally appear
as "tractable cases" of a general theory. As an outcome of this, we provide
extensions of known results. We believe that this put these into next context
and perspective. For example, we prove that the sparse--dense dichotomy exactly
corresponds to random free graphons. The second part of the paper is devoted to
the study of sparse structures. First, we consider limits of structures with
bounded diameter connected components and we prove that in this case the
convergence can be "almost" studied component-wise. We also propose the
structure of limits objects for convergent sequences of sparse structures.
Eventually, we consider the specific case of limits of colored rooted trees
with bounded height and of graphs with bounded tree-depth, motivated by their
role of elementary brick these graphs play in decompositions of sparse graphs,
and give an explicit construction of a limit object in this case. This limit
object is a graph built on a standard probability space with the property that
every first-order definable set of tuples is measurable. This is an example of
the general concept of {\em modeling} we introduce here. Our example is also
the first "intermediate class" with explicitly defined limit structures.


title:
Criteria of ergodicity for $p$-adic dynamical systems in terms of
  coordinate functions

abstract:
  This paper is devoted to the problem of ergodicity of $p$-adic dynamical
systems. Our aim is to present criteria of ergodicity in terms of coordinate
functions corresponding to digits in the canonical expansion of $p$-adic
numbers. The coordinate representation can be useful, e.g., for applications to
cryptography. Moreover, by using this representation we can consider non-smooth
$p$-adic transformations. The basic technical toolsare van der Put series and
usage of algebraic structure (permutations) induced by coordinate functions
with partially frozen variables. We illustrate the basic theorems by presenting
concrete classes of ergodic functions.


title:
Classical random field viewpoint to
  Gorini-Kossakowski-Sudarshan-Lindblad equation and its linear and nonlinear
  generalizations

abstract:
  We show that the basic equation of theory of open systems,
Gorini-Kossakowski-Sudarshan-Lindblad equation, as well as its linear and
nonlinear generalizations have a natural classical probabilistic interpretation
- in the framework of prequantum classical statistical field theory. The latter
gives an example of a classical probabilistic model (with random fields as
subquantum variables) reproducing the basic probabilistic predictions of
quantum mechanics.


title: Unbound geodesics from the ergosphere and the M87 jet profile

abstract:
  Assuming that the spin $a$ of the black hole, presumably located at the core
of the active galactic nuclei Messier 87 (M87), takes the value which maximises
the ergospheric volume of the Kerr spacetime, we find results compatible with
the recent observations obtained by high resolution interferometry on the
origin of the jet, which would be located inside the innermost stable circular
orbit diameter. Moreover, we find a flow of unbound geodesics issued from the
ergoregion able to frame the best fits at large scale recently obtained for
describing the observed profile of the relativistic jet launched from this
central engine.


title:
Two-component universe containing ordinary mater and a new component of
  the form $\frac{l}{R}\rho$

abstract:
  We consider a model of the universe described by Einstein equations whose the
right-hand side consists of ordinary energy-momentum tensor and an effective
vacuum energy-momentum tensor with $\rho^{vac}=-p^{vac}=L_c/K$, where $L_c=8\pi
Gl\rho R^{-1}$ and $\rho$ is the mass density of cosmical medium, $l$ the
constat with dimension $[cm]$ and $R$ the scale factor of the expanding
universe. We determine the vacuum energy density assigned to the term $L_c$ as
a function of the scale factor and, when taking $l=2R_0$, $R_0$ being the
present 'radius' of the universe, and $\Omega_0=0.3$, the normalized vacuum
mass density, we obtain $\Omega_t=1$, deceleration parameter $q_0\approx -0.5$
and the age of the universe $t_0\approx 0.9\times H_0^{-1}$. The values are
compatible with the estimated observatory values of cosmic parameters. Finally,
we try to interpret the energy content of $L_c$ as the field energy of a field
whose source is the ordinary matter in the universe.


title: Goldbach conjecture sequences in quantum mechanics

abstract:
  We show that there is a correspondence between Goldbach conjecture sequences
(GCS) and expectation values of the number operator in Fock states. We
demonstrate that depending on the normalization or not of Fock state
superpositions, we have sequences that are equivalent and sequences that are
not equivalent to GCS. We propose an algorithm where sequences equivalent to
GCS can be derived in terms of expectation values with normalized states.
Defining states whose projections generate GCS, we relate this problem to
eigenstates of quantum harmonic oscillator and discuss Fock states directly
associated to GCS, taking into account the hamiltonian spectrum and quantum
vacuum fluctuations. Finally, we address the problems of degeneracy, maps
associating GCS and Goldbach partitions.


title:
High-precision Absolute Coordinate Measurement using Frequency Scanned
  Interferometry

abstract:
  In this paper, we report high-precision absolute position measurement
performed with frequency scanned interferometry (FSI). We reported previously
on measurement of absolute distance with FSI [1]. Absolute position is
determined by several related absolute distances measured simultaneously. The
achieved precision of 2-dimensional measurements is better than 1 micron, and
in 3-dimensional measurements, the precision on X and Y is confirmed to be
below 1 micron, while the confirmed precision on Z is about 2 microns, where
the confirmation is limited by the lower precision of the moving stage in Z
direction.


title: Tropical covers of curves and their moduli spaces

abstract:
  We define the tropical moduli space of covers of a tropical line in the plane
as weighted abstract polyhedral complex, and the tropical branch map recording
the images of the simple ramifications. Our main result is the invariance of
the degree of the branch map, which enables us to give a tropical
intersection-theoretic definition of tropical triple Hurwitz numbers. We show
that our intersection-theoretic definition coincides with the one given by
Bertrand, Brugall\'e and Mikhalkin in the article "Tropical Open Hurwitz
numbers" where a Correspondence Theorem for Hurwitz numbers is proved. Thus we
provide a tropical intersection-theoretic justification for the multiplicities
with which a tropical cover has to be counted. Our method of proof is to
establish a local duality between our tropical moduli spaces and certain moduli
spaces of relative stable maps to the projective line.


title: The Neutrinos of the Neighboring Brane

abstract:
  The phenomenon of neutrino oscillations is studied usually as a mixing
between the flavor neutrinos and the neutrinos having a definite mass. The
mixing angles and the mass eigenvalues are treated independently in order to
accommodate the experimental data. We suggest that neutrino oscillations are
connected to the structure of spacetime. We expand on a recently proposed
model, where two "mirror" branes coexist. One brane hosts left-handed particles
(our brane), while the other brane hosts right-handed particles. Majorana-type
couplings mixes neutrinos in an individual brane, while Dirac-type couplings
mixes neutrinos across the brares. We first focus our attention in a single
brane. The mass matrix, determined by the Majorana mass, leads to mass
eigenstates and further to mixing angles identical to the mixing angles
proposed by the tri-bimaximal mixing. When we include the Dirac-type coupling,
connecting the two branes, we obtain a definite prediction for the transition
to a sterile neutrino (right-handed neutrino). With m_L (m_R) the Majorana mass
for the left (right) brane, we are able to explain the solar and the
atmospheric neutrino data with m_L = 2m_R and m_R = 10**(-2) eV.


title:
Muon spin rotation studies of niobium for superconducting RF
  applications

abstract:
  In this work we investigate superconducting properties of niobium samples via
application of the muon spin rotation/relaxation (muSR) technique. We employ
for the first time the muSR technique to study samples that are cutout from
large and small grain 1.5 GHz radio frequency (RF) single cell niobium
cavities. The RF test of these cavities was accompanied by full temperature
mapping to characterize the RF losses in each of the samples. Results of the
muSR measurements show that standard cavity surface treatments like mild baking
and buffered chemical polishing (BCP) performed on the studied samples affect
their surface pinning strength. We find an interesting correlation between high
field RF losses and field dependence of the sample magnetic volume fraction
measured via muSR. The muSR line width observed in ZF-muSR measurements matches
the behavior of Nb samples doped with minute amounts of Ta or N impurities. An
upper bound for the upper critical field Hc2 of these cutouts is found.


title: Large-Scale Pattern Search Using Reduced-Space On-Disk Suffix Arrays

abstract:
  The suffix array is an efficient data structure for in-memory pattern search.
Suffix arrays can also be used for external-memory pattern search, via
two-level structures that use an internal index to identify the correct block
of suffix pointers. In this paper we describe a new two-level suffix
array-based index structure that requires significantly less disk space than
previous approaches. Key to the saving is the use of disk blocks that are based
on prefixes rather than the more usual uniform-sampling approach, allowing
reductions between blocks and subparts of other blocks. We also describe a new
in-memory structure based on a condensed BWT string, and show that it allows
common patterns to be resolved without access to the text. Experiments using 64
GB of English web text and a laptop computer with just 4 GB of main memory
demonstrate the speed and versatility of the new approach. For this data the
index is around one- third the size of previous two-level mechanisms; and the
memory footprint of as little as 1% of the text size means that queries can be
processed more quickly than is possible with a compact FM-INDEX.


title:
On the Physics Connecting Cosmic Rays and Gamma Rays: Towards
  Determining the Interstellar Cosmic Ray Spectrum

abstract:
  Secondary nuclear production physics is receiving increased attention given
the high-quality measurements of the gamma-ray emissivity of local interstellar
gas between ~50 MeV and ~40 GeV, obtained with the Large Area Telescope on
board the Fermi space observatory. More than 90% of the gas-related emissivity
above 1 GeV is attributed to gamma-rays from the decay of neutral pions formed
in collisions between cosmic rays and interstellar matter, with lepton-induced
processes becoming increasingly important below 1 GeV. The elementary
kinematics of neutral pion production and decay are re-examined in light of two
physics questions: does isobaric production follow a scaling behavior? and what
is the minimum proton kinetic energy needed to make a gamma-ray of a certain
energy formed through intermediate pi0 production? The emissivity spectrum will
allow the interstellar cosmic-ray spectrum to be determined reliably, providing
a reference for origin and propagation studies as well as input to solar
modulation models. A method for such an analysis and illustrative results are
presented.


title: Hidden order in serrated flow of metallic glasses

abstract:
  We report results of statistical and dynamic analysis of the serrated
stress-time curves obtained from compressive constant strain-rate tests on two
metallic glass samples with different ductility levels in an effort to extract
hidden information in the seemingly irregular serrations. Two distinct types of
dynamics are detected in these two alloy samples. The stress-strain curve
corresponding to the less ductile $Zr_{65}Cu_{15}Ni_{10}Al_{10}$ alloy is shown
to exhibit finite correlation dimension and a positive Lyapunov exponent,
suggesting that the underlying dynamics is chaotic. In contrast, for the more
ductile $Cu_{47.5}Zr_{47.5}Al_{5}$ alloy, the distributions of stress drop
magnitudes and their time durations obey a power law scaling reminiscent of a
self-organized critical state. The exponents also satisfy the scaling relation
compatible with self-organized criticality. Possible physical mechanisms
contributing to the two distinct dynamic regimes are discussed by drawing on
the analogy with the serrated yielding of crystalline samples. The analysis,
together with some physical reasoning, suggests that plasticity in the less
ductile sample can be attributed to stick-slip of single shear band, while that
of the more ductile sample could be attributed to the simultaneous nucleation
of large number of shear bands and their mutual interactions.


title: Relative Fundamental Groups and Rational Points

abstract:
  In this paper we define a relative rigid fundamental group, which associates
to a section $p$ of a smooth and proper morphism $f:X\rightarrow S$ in
characteristic $p$, a Hopf algebra in the ind-category of overconvergent
$F$-isocrystals on $S$. We prove a base change property, which says that the
fibres of this object are the Hopf algebras of the rigid fundamental groups of
the fibres of $f$. We explain how to use this theory to define period maps as
Kim does for varieties over number fields, and show in certain cases that the
targets of these maps can be interpreted as varieties.


title:
Identifying Compiler Options to Minimise Energy Consumption for Embedded
  Platforms

abstract:
  This paper presents an analysis of the energy consumption of an extensive
number of the optimisations a modern compiler can perform. Using GCC as a test
case, we evaluate a set of ten carefully selected benchmarks for five different
embedded platforms.
  A fractional factorial design is used to systematically explore the large
optimisation space (2^82 possible combinations), whilst still accurately
determining the effects of optimisations and optimisation combinations.
Hardware power measurements on each platform are taken to ensure all
architectural effects on the energy consumption are captured.
  We show that fractional factorial design can find more optimal combinations
than relying on built in compiler settings. We explore the relationship between
run-time and energy consumption, and identify scenarios where they are and are
not correlated.
  A further conclusion of this study is the structure of the benchmark has a
larger effect than the hardware architecture on whether the optimisation will
be effective, and that no single optimisation is universally beneficial for
execution time or energy consumption.


title: Unbounded Subnormal Composition Operators in L2-Spaces

abstract:
  A criterion for subnormality of unbounded composition operators in L2-spaces,
written in terms of measurable families of probability measures satisfying the
so-called consistency condition, is established. It becomes a new
characterization of subnormality in the case of bounded composition operators.
Pseudo-moments of a measurable family of probability measures that satisfies
the consistency condition are proved to be given by the Radon-Nikodym
derivatives which appear in Lambert's characterization of bounded composition
operators. A criterion for subnormality of composition operators induced by
matrices is provided. The question of subnormality of composition operators
over discrete measure spaces is studied. Two new classes of subnormal
composition operators over discrete measure spaces are introduced. A recent
criterion for subnormality of weighted shifts on directed trees by the present
authors is essentially improved in the case of rootless directed trees and
nonzero weights by dropping the assumption of density of C\infty-vectors in the
underlying L2-space.


title: Breit-Wheeler process in very short electromagnetic pulses

abstract:
  The generalized Breit-Wheeler process, i.e. the emission of $e^+e^-$ pairs
off a probe photon propagating through a polarized short-pulsed electromagnetic
(e.g.\ laser) wave field, is analyzed. We show that the production probability
is determined by the interplay of two dynamical effects. The first one is
related to the shape and duration of the pulse and the second one is the
non-linear dynamics of the interaction of $e^\pm$ with the strong
electromagnetic field. The first effect manifests itself most clearly in the
weak-field regime, where the small field intensity is compensated by the rapid
variation of the electromagnetic field in a limited space-time region, which
intensifies the few-photon events and can enhance the production probability by
orders of magnitude compared to an infinitely long pulse. Therefore, short
pulses may be considered as a powerful amplifier. The non-linear dynamics in
the multi-photon Breit-Wheeler regime plays a decisive role at large field
intensities, where effects of the pulse shape and duration are less important.
In the transition regime, both effects must be taken into account
simultaneously. We provide suitable expressions for the $e^+e^-$ production
probability for kinematic regions which can be used in transport codes.


title:
Dualities and bosonization of massless fermions in three dimensional
  space-time

abstract:
  We study the bosonization of massless fermions in three-dimensional
space-time. Using the path-integral approach as well as the operator formalism,
we investigate new duality relations between fermionic and bosonic theories. In
particular, we show that a theory of massless fermions is dual to three
different, but equivalent bosonic theories which are quadratic in the bosonic
fields: a non-local Maxwell- Chern-Simons-type theory, a non-local
self-dual-type vector theory, and a local free massless bosonic theory. The
equivalence is proven at the level of current correlation functions and current
algebra analysis.


title: Spectroscopy of H II Regions in the Late-Type Spiral Galaxy NGC 6946

abstract:
  We present the results of spectroscopy of 39 H II regions in the spiral
galaxy NGC 6946. The spectral observations were carried out at the 6-m BTA
telescope of the SAO RAS with the SCORPIO focal reducer in the multi-slit mode
with the dispersion of 2.1A/px and spectral resolution of 10A. The absorption
estimates for 39 H II regions were obtained. Using the "strong line" method
(NS-calibration) we determined the electron temperature, and the abundances of
oxygen and nitrogen for 30 H II regions. The radial gradients of O/H and N/H
were constructed.


title: Equilibrium Configurations of Cantilever under Terminal Loads

abstract:
  The paper provides an exact analytical solution for equilibrium
configurations of cantilever rod subject to inclined force and torque acting on
its free end. The solution is given in terms of Jacobi elliptical functions and
illustrated by several numerical examples and several graphical presentations
of shapes of deformed cantilever. Possible forms of cantilever underlying
elastica are discussed in details and various simple formulas are given for
calculation of characteristic dimensions of elastica. For the case when
cantilever is subject only to applied force four load conditions are discussed:
follower load problem, load determination problem, conservative load problem
and rotational load problem. For all the cases the formulas or effective
procedure for solution is given.


title: On the geometry of Abel maps for nodal curves

abstract:
  In this paper we give local conditions to the existence of Abel maps for
nodal curves that are limits of Abel maps for smooth curves. We use this result
to construct Abel maps for any degree for nodal curves with two components.


title: Religion in the cosmological ideas in Ukraine (from XI to XVII century)

abstract:
  Cosmology, whose object is the Universe, is in contact with the religion
closer than any other science. We will try to trace the historical change of
views on the universe in Ukraine from XI to XVII centuries and show the
influence of religion in the construction of the models of the Universe in that
time.


title: Constructing Intrinsic Delaunay Triangulations of Submanifolds

abstract:
  We describe an algorithm to construct an intrinsic Delaunay triangulation of
a smooth closed submanifold of Euclidean space. Using results established in a
companion paper on the stability of Delaunay triangulations on $\delta$-generic
point sets, we establish sampling criteria which ensure that the intrinsic
Delaunay complex coincides with the restricted Delaunay complex and also with
the recently introduced tangential Delaunay complex. The algorithm generates a
point set that meets the required criteria while the tangential complex is
being constructed. In this way the computation of geodesic distances is
avoided, the runtime is only linearly dependent on the ambient dimension, and
the Delaunay complexes are guaranteed to be triangulations of the manifold.


title: Moments of a length function on the boundary of a hyperbolic manifold

abstract:
  In this paper we will study the statistics of the unit geodesic flow normal
to the boundary of a hyperbolic manifold with non-empty totally geodesic
boundary. Viewing the time it takes this flow to hit the boundary as a random
variable, we derive a formula for its moments in terms of the orthospectrum.
The first moment gives the average time for the normal flow acting on the
boundary to again reach the boundary, which we connect to Bridgeman's identity
(in the surface case), and the zeroth moment recovers Basmajian's identity.
Furthermore, we are able to give explicit formulae for the first moment in the
surface case as well as for manifolds of odd dimension. In dimension two, the
summation terms are dilogarithms. In dimension three, we are able to find the
moment generating function for this length function.


title: Parametrization of the box variety by theta functions

abstract:
  We describe a parametrization of the box variety (variety of cuboids) by
theta functions. This will imply that the box variety is a modular variety.
Actually this parametrization can be defined over the Gauss number field.


title:
Flow of strange and charm particles in Pb--Pb collisions at sqrt{s_{NN}}
  = 2.76 TeV measured with ALICE

abstract:
  The ALICE experiment studies Pb-Pb collisions at the LHC in order to
investigate the properties of the hot and dense QCD matter at extreme energy
densities. Recent results from ALICE in identified particle flow allow for the
exploration of the collective properties of the medium created in heavy-ion
collisions. In this paper, I give special attention to strange and charm
particles which probe the medium differently and thus provide new constraints
for the study of its properties. The paper covers results on elliptic flow for
pion, kaon, kzero, antiproton, phi, lambda, xi, omega, dplus, dzero and dstar
measured at midrapidity by ALICE in Pb-Pb collisions at sqrt{s_{NN}} = 2.76
TeV. I present also the comparison with available models that predict the
hydrodynamical evolution of the medium and the energy loss of light and heavy
quarks as they travel through.


title: Entanglement verification using local unitary stabilizers

abstract:
  Local unitary stabilizer subgroups constitute powerful invariants for
distinguishing various types of multipartite entanglement. In this paper, we
show how stabilizers can be used as a basis for entanglement verification
protocols on distributed quantum networks using minimal resources. As an
example, we develop and analyze the performance of a protocol to verify
membership in the space of Werner states, that is, multi-qubit states that are
invariant under the action of any 1-qubit unitary applied to all the qubits.


title:
Number and profile of low energy solutions for singularly perturbed
  Klein Gordon Maxwell systems on a Riemannian manifold

abstract:
  Given a 3-dimensional Riemannian manifold (M,g), we investigate the existence
of positive solutions of the nonlinear Klein-Gordon-Maxwell system and
nonlinear Schroedinger-Maxwell system with subcritical nonlinearity. We prove
that the number of one peak solutions depends on the topological properties of
the manifold M, by means of the Lusternik Schnirelmann category.


title:
Vertical settling and radial segregation of large dust grains in the
  circumstellar disk of the Butterfly Star

abstract:
  Context: Circumstellar disks are considered to be the environment for the
formation of planets. The growth of dust grains in these disks is the first
step in the core accretion-gas capture planet formation scenario. Indicators
and evidence of disk evolution can be traced in spatially resolved images and
the spectral energy distribution (SED) of these objects.
  Aims: We develop a model for the dust phase of the edge-on oriented
circumstellar disk of the Butterfly Star which allows one to fit observed
multi-wavelength images and the SED simultaneously.
  Methods: Our model is based on spatially resolved high angular resolution
observations at 1.3 mm, 894 micron, 2.07 micron, 1.87 micron, 1.60 micron, and
1.13 micron and an extensively covered SED ranging from 12 micron to 2.7 mm,
including a detailed spectrum obtained with the Spitzer Space Telescope in the
range from 12 micron to 38 micron. A parameter study based on a grid search
method involving the detailed analysis of every parameter was performed to
constrain the disk parameters and find the best-fit model for the independent
observations. The individual observations were modeled simultaneously, using
our continuum radiative transfer code.
  Results: We derived a model that is capable of reproducing all of the
observations of the disk at the same time. We find quantitative evidence for
grain growth up to ~100 micron-sized particles, vertical settling of larger
dust grains toward the disk midplane, and radial segregation of the latter
toward the central star. Within our best-fit model the large grains have a
distribution with a scale height of 3.7 AU at 100 AU and a radial extent of 175
AU compared to a hydrostatic scale height of 6.9 AU at 100 AU and an outer disk
radius of 300 AU. Our results are consistent with current theoretical models
for the evolution of circumstellar disks and the early stages of planet
formation.


title:
On the Group Classification of Systems of Two Linear Second-Order
  Ordinary Differential Equations with Constant Coefficients

abstract:
  The completeness of the group classification of systems of two linear
second-order ordinary differential equations with constant coefficients is
delineated in the paper. The new cases extend what has been done in the
literature. These cases correspond to the type of equations where the
commutative property of the coefficient matrices with respect to the dependent
variables and the first-order derivatives in the considered system does not
hold. A discussion of the results as well as a note on the extension to linear
systems of second-order ordinary differential equations with more than two
equations are given.


title:
Enhanced pinning in high-temperature superconducting cuprate single
  crystals at low DC magnetic field

abstract:
  Low density flux dynamics in Nd based cuprate (NdBa2Cu3O7-x) HTSC single
crystals trapped in 1 Oe range DC magnetic fields were investigated for the
first time. Complex measurements of time, temperature and field dependence of
magnetization were performed. Using the results obtained and the Anderson-Kim
model the normalized magnetization relaxation rate S and the averaged effective
pinning potential U were calculated. We show a significant (one or even two
orders) increase in the effective pinning potential in these samples in
comparison with measurements performed in high magnetic fields for similar
cuprate single crystals formerly. In a wide enough range of temperatures close
to Tc (0.72 < T/Tc < 0.93) it has been shown that the doping of NdBa2Cu3O7-x
single crystals with calcium atoms leads to the increase of the averaged
effective pinning potential with an insignificant decreasing of the critical
temperature.


title:
4-manifolds, surgery on loops and geometric realization of Tietze
  transformations

abstract:
  In the paper \cite{wall_1}, C.T.C. Wall proved that two smooth closed simply
connected 4-manifolds which are homeomorphic are in fact stably diffeomorphic.
We prove a similar result which states that two smooth closed 4-manifolds
satisfying certain properties are stably diffeomorphic if and only if their
signatures agree. The manifolds in question are obtained by surgery on loops.
The methods we use are modified surgery of Kreck \cite{kreck} and Kirby
calculus.


title: Optic phonons and the soft mode in 2H-NbSe2

abstract:
  We present an investigation of the lattice dynamics of the
charge-density-wave compound 2H-NbSe2. We analyze the precise nature of the
wave vector dependent electron-phonon coupling (EPC) and derive the bare
dispersion of the charge-density-wave (CDW) soft phonon mode using inelastic
x-ray scattering combined with ab-initio calculations. Experimentally, phonon
modes along the {\Gamma} - M line, i.e. q = (h, 0, 0) with 0 <= h <= 0.5, with
the same longitudinal symmetry ({\Sigma}1) as the CDW soft mode were
investigated up to 32 meV. In agreement with our calculations we observe
significant EPC in the optic modes at h <= 0.2. We analyze the EPC in the optic
as well as acoustic modes and show that the q dependences stem from scattering
processes between two bands at the Fermi surface both having Nb 4d character.
Finally, we demonstrate that the soft mode dispersion at T = 33 K (= {T_{CDW}})
can be well described on the basis of a strongly q dependent EPC matrix element
and an acoustic-like bare phonon dispersion in agreement with observations near
room temperature.


title:
Nondegeneracy of critical points of the mean curvature of the boundary
  for Riemannian manifolds

abstract:
  Let $M$ be a compact smooth Riemannian manifold of finite dimension $n+1$
with boundary $\partial M$and $\partial M$ is a compact $n$-dimensional
submanifold of $M$. We show that for generic Riemannian metric $g$, all the
critical points of the mean curvature of $\partial M$ are nondegenerate.


title: On certain mean values of the double zeta-function

abstract:
  In this paper we discuss three types of the mean values of the Euler double
zeta function. In order to get results we introduce three approximate formulas
for this function.


title:
Large-scale inhomogeneities of the intracluster medium: improving mass
  estimates using the observed azimuthal scatter

abstract:
  Using a set of hydrodynamical simulations of 62 galaxy clusters and groups we
study the ICM of inhomogeneities, focusing on the ones on the large scale that,
unlike clumps, are the most difficult to identify. To this purpose we introduce
the concept of residual clumpiness, C_R, that quantifies the large-scale
inhomogeneity of the ICM. After showing that this quantity can be robustly
defined for relaxed systems, we characterize how it varies with radius, mass
and dynamical state of the halo. Most importantly, we observe that it
introduces an overestimate in the determination of the density profile from the
X-ray emission, which translates into a systematic overestimate of 6 (12)% in
the measurement of M_gas at R_200 for our relaxed (perturbed) cluster sample.
At the same time, the increase of C_R with radius introduces also a ~2%
systematic underestimate in the measurement of the hydrostatic-equilibrium mass
(M_he), which adds to the previous one generating a systematic ~8.5%
overestimate in f_gas in our relaxed sample. Since the residual clumpiness of
the ICM is not directly observable, we study its correlation with the azimuthal
scatter in the X-ray surface brightness of the halo and in the y-parameter
profiles. We find that their correlation is highly significant (r_S = 0.6-0.7),
allowing to define the azimuthal scatter measured in the X-ray surface
brightness profile and in the y-parameter as robust proxies of C_R. After
providing a function that connects the two quantities, we obtain that
correcting the observed gas density profiles using the azimuthal scatter
eliminates the bias in the measurement of M_gas for relaxed objects, which
becomes (0+/-2)% up to 2R_200, and reduces it by a factor of 3 for perturbed
ones. This method allows also to eliminate the systematics on the measurements
of M_he and f_gas, although a significant halo to halo scatter remains.
(abridged)


title: A Markov model for Selmer ranks in families of twists

abstract:
  We study the distribution of 2-Selmer ranks in the family of quadratic twists
of an elliptic curve E over an arbitrary number field K. Under the assumption
that Gal(K(E[2])/K) = S_3 we show that the density (counted in a non-standard
way) of twists with Selmer rank r exists for all positive integers r, and is
given via an equilibrium distribution, depending only on a single parameter
(the `disparity'), of a certain Markov process that is itself independent of E
and K. More generally, our results also apply to p-Selmer ranks of twists of
2-dimensional self-dual F_p-representations of the absolute Galois group of K
by characters of order p.


title:
Superscaling in electron-nucleus scattering and its link to CC and NC QE
  neutrino-nucleus scattering

abstract:
  The superscaling approach (SuSA) to neutrino-nucleus scattering, based on the
assumed universality of the scaling function for electromagnetic and weak
interactions, is reviewed. The predictions of the SuSA model for bot CC and NC
differential and total cross sections are presented and compared with the
MiniBooNE data. The role of scaling violations, in particular the contribution
of meson exchange currents in the two-particle two-hole sector, is explored.


title: Additional reductions in the k-constrained modified KP hierarchy

abstract:
  Additional reductions in the modified k-constrained KP hierarchy are
proposed. As a result we obtain generalizations of Kaup-Broer system,
Korteweg-de Vries equation and a modification of Korteweg-de Vries equation
that belongs to modified k-constrained KP hierarchy. We also propose solution
generating technique based on binary Darboux transformations for the obtained
equations.


title:
A new bidirectional generalization of (2+1)-dimensional matrix
  k-constrained KP hierarchy

abstract:
  We introduce a new bidirectional generalization of (2+1)-dimensional
k-constrained KP hierarchy ((2+1)-BDk-cKPH). This new hierarchy generalizes
(2+1)-dimensional k-cKP hierarchy, $(t_A,\tau_B)$ and $(\gamma_A,\sigma_B)$
matrix hierarchies. (2+1)-BDk-cKPH contains a new matrix (1+1)-k-constrained KP
hierarchy. Some members of (2+1)-BDk-cKPH are also listed. In particular, it
contains matrix generalizations of DS systems, (2+1)-dimensional modified
Korteweg-de Vries equation and the Nizhnik equation. (2+1)-BDk-cKPH also
includes new matrix (2+1)-dimensional generalizations of the Yajima-Oikawa and
Melnikov systems. Binary Darboux Transformation Dressing Method is also
proposed for construction of exact solutions for equations from (2+1)-BDk-cKPH.
As an example the exact form of multi-soliton solutions for vector
generalization of the Davey-Stewartson system is given.


title:
The electrostatic interaction of an external charged system with a metal
  surface: a simplified density functional theory approach

abstract:
  As a first step to meet the challenge to calculate the electronic structure
and total energy of charged states of atoms and molecules adsorbed on
ultrathin-insulating films supported by a metallic substrate using density
functional theory (DFT), we have developed a simplified new DFT scheme that
only describes the electrostatic interaction of an external charged system with
a metal surface. This purely electrostatic interaction is obtained from the
assumption that the electron densities of the two fragments (charged system and
metal surface) are non-overlapping and neglecting non-local exchange
correlation effects such as the van der Waals interactions between the two
fragments. In addition, the response of the metal surface to the electrostatic
potential from the charged system is treated to linear order, whereas the
charged system is treated fully within DFT. In particular, we consider the
classical perfect conductor (PC) model for the metal response, although our
formalism is not limited to this approximation. The successful computational
implementation of this new methodology and the PC model is exemplified by the
case of a Na$^{+}$ cation outside a metal surface.


title: Web Service Interface for Data Collection

abstract:
  Data collection is a key component of an information system. The widespread
penetration of ICT tools in organizations and institutions has resulted in a
shift in the way the data is collected. Data may be collected in printed-form,
by e-mails, on a compact disk, or, by direct upload on the management
information system. Since web services are platform-independent, it can access
data stored in the XML format from any platform. In this paper, we present an
interface which uses web services for data collection. It requires interaction
between a web service deployed for the purposes of data collection, and the web
address where the data is stored. Our interface requires that the web service
has pre-knowledge of the address from where the data is to be collected. Also,
the data to be accessed must be stored in XML format. Since our interface uses
computer-supported interaction on both sides, it eases the task of regular and
ongoing data collection. We apply our framework to the Education Management
Information System, which collects data from schools spread across the country.


title: The density of primes in orbits of z^d + c

abstract:
  Given a polynomial f(z) = z^d + c over a global field K and a_0 in K, we
study the density of prime ideals of K dividing at least one element of the
orbit of a_0 under f. The density of such sets for linear polynomials has
attracted much study, and the second author has examined several families of
quadratic polynomials, but little is known in the higher-degree case. We show
that for many choices of d and c this density is zero for all a_0, assuming K
contains a primitive dth root of unity. The proof relies on several new
results, including some ensuring the number of irreducible factors of the nth
iterate of f remains bounded as n grows, and others on the ramification above
certain primes in iterated extensions. Together these allow for nearly complete
information when K is a global function field or when K=Q(zeta_d).


title: Beam optics and lattice design for particle accelerators

abstract:
  The goal of this manuscript is to give an introduction into the design of the
magnet lattice and as a consequence into the transverse dynamics of the
particles in a synchrotron or storage ring. Starting from the basic principles
of how to design the geometry of the ring we will briefly review the transverse
motion of the particles and apply this knowledge to study the layout and
optimization of the principal elements, namely the lattice cells. The detailed
arrangement of the accelerator magnets within the cells is explained and will
be used to calculate well defined and predictable beam parameters. The more
specific treatment of low beta insertions is included as well as the concept of
dispersion suppressors that are an indispensable part of modern collider rings.


title: Dimension 7 operators in the b to s transition

abstract:
  We extend the low-energy effective field theory relevant for b to s
transitions up to operators of mass-dimension 7 and compute the associated
anomalous-dimension matrix. We then compare our findings to the known results
for dimension 6 operators and derive a solution for the renormalization group
equations involving operators of dimension 7. We finally apply our analysis to
a particularly simple case where the Standard Model is extended by an
electroweak-magnetic operator and consider limits on this scenario from the
decays Bs to mu+ mu- and B to K nu nubar.


title: Thermodynamic Relaxation Drives Expulsion in Giant Unilamellar Vesicles

abstract:
  We investigated the thermodynamic relaxation of giant unilamellar vesicles
(GUVs) which contained small vesicles within their interior. Quenching these
vesicles from their fluid phase (T>Tm) through the phase transition in the gel
state (T<Tm) drives the inner vesicles to be expelled from the larger mother
vesicle via the accompanying decrease in vesicle area by ~25% which forces a
pore to open in the mother vesicle. We demonstrate that the proceeding time
evolution of the resulting efflux follows the relaxation of the membrane area
and describe the entire relaxation process using an Onsager-like nonequilibrium
thermodynamics ansatz. As a consequence of the volume efflux internal vesicles
are expelled from the mother vesicle. Although complete sealing of the pore may
occur during the expulsion, the global relaxation dynamics is conserved.
Finally, comparison of these results to morphological relaxation phenomena
found in earlier studies reveals a universal relaxation behaviour in GUVs. When
quenched from the fluid to gel phase the typical time scale of relaxation shows
little variation and ranges between 4-5 seconds.


title: Phase Transition and dissipation driven budding in lipid vesicles

abstract:
  Membrane budding has been extensively studied as an equilibrium process
attributed to the formation of coexisting domains or changes in the vesicle
area to volume ratio (reduced volume). In contrast, non-equilibrium budding
remains experimentally widely unexplored especially when time scales fall well
below the characteristic diffusion time of lipids{\tau} . We show that
localized mechanical perturbations, initiated by driving giant unilamellar
vesicles (GUVs) through their lipid phase transition, leads to the immediate
formation of rapidly growing, multiply localized, non-equilibrium buds, when
the transition takes place at short timescales (<{\tau}). We show that these
buds arise from small fluid-like perturbations and grow as spherical caps in
the third dimension, since in plane spreading is obstructed by the continuous
rigid gel-like matrix. Accounting for both three and two dimensional viscosity,
we demonstrate that dissipation decreases the size scale of the system and
therefore favours the formation of multiple buds as long as the perturbation
takes place above a certain critical rate. This rate depends on membrane and
media viscosity and is qualitatively and quantitatively correctly predicted by
our theoretical description.


title:
SRP-MS: A New Routing Protocol for Delay Tolerant Wireless Sensor
  Networks

abstract:
  Sink Mobility is becoming popular due to excellent load balancing between
nodes and ultimately resulting in prolonged network lifetime and throughput. A
major challenge is to provide reliable and energy-efficient operations are to
be taken into consideration for differentmobility patterns of sink. Aim of this
paper is lifetime maximization of Delay TolerantWireless Sensor Networks (WSNs)
through the manipulation of Mobile Sink (MS) on different trajectories. We
propose Square Routing Protocol with MS (SRP-MS) based on existing SEP (Stable
Election Protocol) by making it Cluster Less (CL) and introducing sink
mobility.


title: Radiation protection at CERN

abstract:
  This paper gives a brief overview of the general principles of radiation
protection legislation; explains radiological quantities and units, including
some basic facts about radioactivity and the biological effects of radiation;
and gives an overview of the classification of radiological areas at CERN,
radiation fields at high-energy accelerators, and the radiation monitoring
system used at CERN. A short section addresses the ALARA approach used at CERN.


title:
Activation and radiation damage in the environment of hadron
  accelerators

abstract:
  A component which suffers radiation damage usually also becomes radioactive,
since the source of activation and radiation damage is the interaction of the
material with particles from an accelerator or with reaction products. However,
the underlying mechanisms of the two phenomena are different. These mechanisms
are described here. Activation and radiation damage can have far-reaching
consequences. Components such as targets, collimators, and beam dumps are the
first candidates for failure as a result of radiation damage. This means that
they have to be replaced or repaired. This takes time, during which personnel
accumulate dose. If the dose to personnel at work would exceed permitted
limits, remote handling becomes necessary. The remaining material has to be
disposed of as radioactive waste, for which an elaborate procedure acceptable
to the authorities is required. One of the requirements of the authorities is a
complete nuclide inventory. The methods used for calculation of such
inventories are presented, and the results are compared with measured data. In
the second part of the paper, the effect of radiation damage on material
properties is described. The mechanism of damage to a material due to
irradiation is described. The amount of radiation damage is quantified in terms
of displacements per atom. Its calculation and deficiencies in explaining and
predicting the changes in mechanical and thermal material properties are
discussed, and examples are given.


title: Estimates for Nonlinear Harmonic Measures on Trees

abstract:
  In this paper we give some estimates for nonlinear harmonic measures on
trees. In particular, we estimate in terms of the size of a set $D$ the value
at the origin of the solution to $ u(x)=F((x,0),\dots,(x,m-1))$ for every
$x\in\mathbb{T}_m, $ a directed tree with $m$ branches with initial datum
$f+\chi_D$. Here $F$ is an averaging operator on $\mathbb{R}^m$, $x$ is a
vertex of a directed tree $\mathbb{T}_m$ with regular $m$-branching and $(x,i)$
denotes a successor of that vertex for $0\le i\le m-1$.


title:
Proposal for a loophole-free Bell test based on spin-photon interactions
  in cavities

abstract:
  We present a scheme to demonstrate loophole-free Bell inequality violation
where the entanglement between photon pairs is transferred to solid state
(spin) qubits mediated by cavity QED interactions. As this transfer can be
achieved in a heralded way, our scheme is basically insensitive to losses on
the channel. This makes it appealing for the implementation of quantum
information protocols based on nonlocality, such as device-independent quantum
key distribution. We consider potential experimental realisations of our scheme
using single atom, colour centre and quantum dot cavity systems.


title:
Proposed experiment to exclude higher-than-quantum violations of the
  Bell inequality

abstract:
  We show that a recent observation by Yan leads to a method to experimentally
test whether a higher-than-quantum violation of the Clauser-Horne-Shimony-Holt
Bell inequality is possible (assuming that the sum of probabilities of pairwise
exclusive propositions cannot exceed 1). The test requires reaching the maximum
quantum violation of a noncontextuality inequality involving sequences of three
compatible measurements on a five-dimensional quantum system.


title: NLO NRQCD disfavors the interpretation of X(3872) as $\chi_{c1}(2P)$

abstract:
  We study $\chi_{c1}(2P)$ inclusive hadroproduction at next-to-leading order
(NLO), both in $\alpha_s$ and $v^2$, within the factorization formalism of
nonrelativistic quantum chromodynamics (NRQCD), including the color-singlet
$^3P_1^{[1]}$ and color-octet $^3S_1^{[8]}$ $c\bar c$ Fock states as well as
the mixing of the latter with the $^3D_1^{[8]}$ state. Assuming the recently
discovered X(3872) hadron to be the $J^{PC}=1^{++}$ charmonium state
$\chi_{c1}(2P)$, we perform a fit to the cross sections measured by the CDF,
CMS, and LHCb Collaborations. We either obtain an unacceptably high value of
$\chi^2$, a value of $|R_{2P}^\prime(0)|$ incompatible with well-established
potential models, or an intolerable violation of the NRQCD velocity rules. We
thus conclude that NLO NRQCD is inconsistent with the hypothesis
$X(3872)\equiv\chi_{c1}(2P)$.


title:
Network analysis reveals distinct clinical syndromes underlying acute
  mountain sickness

abstract:
  Acute mountain sickness (AMS) is a common problem among visitors at high
altitude, and may progress to life-threatening pulmonary and cerebral oedema in
a minority of cases. International consensus defines AMS as a constellation of
subjective, non-specific symptoms. Specifically, headache, sleep disturbance,
fatigue and dizziness are given equal diagnostic weighting. Different
pathophysiological mechanisms are now thought to underlie headache and sleep
disturbance during acute exposure to high altitude. Hence, these symptoms may
not belong together as a single syndrome. Using a novel visual analogue scale
(VAS), we sought to undertake a systematic exploration of the symptomatology of
AMS using an unbiased, data-driven approach originally designed for analysis of
gene expression. Symptom scores were collected from 293 subjects during 1110
subject-days at altitudes between 3650m and 5200m on Apex expeditions to
Bolivia and Kilimanjaro. Three distinct patterns of symptoms were consistently
identified. Although fatigue is a ubiquitous finding, sleep disturbance and
headache are each commonly reported without the other. The commonest pattern of
symptoms was sleep disturbance and fatigue, with little or no headache. In
subjects reporting severe headache, 40% did not report sleep disturbance. Sleep
disturbance correlates poorly with other symptoms of AMS (Pearson r = 0.31 vs
headache). These results challenge the accepted paradigm that AMS is a single
disease process and describe at least two distinct syndromes following acute
ascent to high altitude. This approach to analysing symptom patterns has
potential utility in other clinical syndromes.


title:
Predicting the statistics of wave transport through chaotic cavities by
  the Random Coupling Model: a review and recent progress

abstract:
  In this review, a model (the Random Coupling Model) that gives a statistical
description of the coupling of radiation into and out of large enclosures
through localized and/or distributed channels is presented. The Random Coupling
Model combines both deterministic and statistical phenomena. The model makes
use of wave chaos theory to extend the classical modal description of the
cavity fields in the presence of boundaries that lead to chaotic ray
trajectories. The model is based on a clear separation between the universal
statistical behavior of the isolated chaotic system, and the deterministic
coupling channel characteristics. Moreover, the ability of the random coupling
model to describe interconnected cavities, aperture coupling, and the effects
of short ray trajectories is discussed. A relation between the random coupling
model and other formulations adopted in acoustics, optics, and statistical
electromagnetics, is examined. In particular, a rigorous analogy of the random
coupling model with the Statistical Energy Analysis used in acoustics is
presented.


title:
Existence theory for a kinetic-fluid coupling when small droplets are
  treated as part of the fluid

abstract:
  We consider in this paper a spray constituted of an incompressible viscous
gas and of small droplets which can breakup. This spray is modeled by the
coupling (through a drag force term) of the incom- pressible Navier-Stokes
equation and of the Vlasov-Boltzmann equation, together with a fragmentation
kernel. We first show at the formal level that if the droplets are very small
after the breakup, then the solutions of this system converge towards the
solution of a simplified system in which the small droplets produced by the
breakup are treated as part of the fluid. Then, existence of global weak
solutions for this last system is shown to hold, thanks to the use of the
DiPerna-Lions theory for singular transport equations.


title: Does gravitational collapse lead to singularities?

abstract:
  According to conventional modelling by general relativity the collapse of
radially symmetric gravitating objects may end in a singular state. But by
inclusion of potential energy into the energy tensor, which is required to
guarantee global energy conservation, the occurrence of singularities is
avoided. Instead the final states of the collapse of mass concentrations of
arbitrary size are nuclear matter objects, from which jets of matter can be
recycled into space. The mysterious dark energy, supposed as the main
constituent of the universe, may even be the potential energy of matter itself.


title: Random generation of optimal saturated designs

abstract:
  Efficient algorithms for searching for optimal saturated designs are widely
available. They maximize a given efficiency measure (such as D-optimality) and
provide an optimum design. Nevertheless, they do not guarantee a \emph{global}
optimal design. Indeed, they start from an initial random design and find a
local optimal design. If the initial design is changed the optimum found will,
in general, be different. A natural question arises. Should we stop at the
design found or should we run the algorithm again in search of a better design?
This paper uses very recent methods and software for discovery probability to
support the decision to continue or stop the sampling. A software tool written
in SAS has been developed.


title:
Non degeneracy of critical points of the Robin function with respect to
  deformations of the domain

abstract:
  We show a result of genericity for non degenerate critical points of the
Robin function with respect to deformations of the domain