title: Dominated Uryson operators on lattice-normed spaces

abstract:
  The aim of this note is to introduce the space D_{U}(V,W) of the dominated
Uryson operators on lattice-normed spaces. We prove an "Up-and-down" type
theorem for a positive abstract Uryson operator defined on a vector lattice and
taking values in a Dedekind complete vector lattice. This result we apply to
prove the decomposability of the lattice valued norm of the space D_{U}(V,W) of
all dominated Uryson operators. We obtain that, for a lattice-normed space V
and a Banach-Kantorovich space W the space D_{U}(V,W) is also a
Banach-Kantorovich space. We prove that under some mild conditions, a dominated
Uryson operator has an exact dominant. We obtain formulas for calculating the
exact dominant of a dominated Uryson operator. We also consider laterally
continuous and completely additive dominated Uryson operators and prove that a
dominated Uryson operator is laterally continuous (completely additive) if and
only if so is its exact dominant.


title: On theory of regular accelerating Universe in Riemann-Cartan spacetime

abstract:
  Isotropic cosmology built in the Riemann-Cartan spacetime is investigated.
Properties of homogeneous isotropic cosmological models filled with usual
gravitating matter and scalar fields are studied in the beginning of
cosmological expansion near the limiting energy density. It is shown that
cosmological models are regular not only with respect to the Hubble parameter
and the energy density but also with respect to the torsion and curvature
tensors.


title: Tonelli Hamiltonians without conjugate points and $C^0$ integrability

abstract:
  We prove that all the Tonelli Hamiltonians defined on the cotangent bundle
$T^*\T^n$ of the $n$-dimensional torus that have no conjugate points are $C^0$
integrable, i.e. $T^*\T^n$ is $C^0$ foliated by a family $\Fc$ of invariant
$C^0$ Lagrangian graphs. Assuming that the Hamiltonian is $C^\infty$, we prove
that there exists a $G_\delta$ subset $\Gc$ of $\Fc$ such that the dynamics
restricted to every element of $\Gc$ is strictly ergodic. Moreover, we prove
that the Lyapunov exponents of every $C^0$ integrable Tonelli Hamiltonian are
zero and deduce that the metric and topological entropies vanish.


title: The model magnetic Laplacian on wedges

abstract:
  We study a model Schr\"odinger operator with constan tmagnetic field on an
infinite wedge with natural boundary conditions. This problem is related to the
semiclassical magnetic Laplacian on 3d domains with edges. We show that the
ground energy is lower than the one coming from the regular part of the wedge
and is continuous with respect to the geometry. We provide an upper bound for
the ground energy on wedges of small opening. Numerical computations enlighten
the theoretical approach.


title:
Discordant Compact Logic-Arithmetic Structures in Discrete Optimization
  Problems

abstract:
  In sphere of research of discrete optimization algorithms efficiency the
important place occupies a method of polynomial reducibility of some problems
to others with use of special purpose components. In this paper a novel method
of compact representation for sets of binary sequences in the form of "compact
triplets structures" (CTS) and "compact couples structures" (CCS) is stated,
supposing both logic and arithmetic interpretation of data. It is shown that
any non-empty CTS in dual interpretation represents some unique Boolean formula
in 3-CNF and the tabular CTS contains all satisfyig sets of the formula as
concatenations of the triplets chosen from the neighbouring tiers. In general,
any 3-CNF formula is transformed by decomposition to a system of discordant
CTS's, each being associated with an individual permutation of variables
constructed by a polynomial algorithm. As a result the problem of the formula
satisfiability is reduced to the following one: ascertain the fact of existence
(or absence) of a "joint satisfying set" (JSS) for all discordant structures,
based on the different permutations. Further transformation of each CTS to CCS
is used; correctness of preservation of the allowed sets is reached by simple
algorithmic restrictions on triplets concatenation. Then the procedure of
"inverting of the same name columns" in the various structures is entered for
the purpose of reducing the problem of JSS revealing to elementary detection of
n-tuples of zeros in the CCS system. The formula is synthesized, being on the
structure a variation of 2-CNF, associated with the calculation procedure
realizing adaptation of the polynomial algorithm of constraints distribution
(well-known in the optimization theory) to the efficient resolving Boolean
formula coded by means of discordant compact structures.


title:
SPS-Sintered NaTaO3-Fe2O3 Composite exhibits Large Seebeck Coefficient
  and Electric Current

abstract:
  NaTaO3-50wt% Fe2O3 composite ceramics showed a large Seebeck voltage of -300
mV at a temperature gradient of 650 K yielding a constant Seebeck coefficient
of more than -500 microV/K over a wide temperature range. We report for the
first time that SPS sintering at low temperature 870K could maintain the
short-circuit current of -80 microA, which makes this thermoelectric material a
possible candidate for high-temperature applications up to 1623 K. The reason
for the good performance is the interface between Fe2O3 and surrounding NaTaO3
perovskite. When spark-plasma sintering (SPS) is used, constitutional vacancies
disappeared and the electric conductivity increases remarkably yielding ZT of
0.016.


title:
On the lowest energy of a 3D magnetic hamiltonian with axisymmetric
  potential

abstract:
  We study the bottom of the spectrum of a magnetic hamiltonian with
axisymmetrical potential in R3. The associated magnetic field is planar,
unitary and non-constant. The problem reduces to a 1D-family of singular
Sturm-Liouville operators on the half-line. We study to associated band
functions and we compare it to the "de Gennes" operators arising in the study
of a 2D-hamiltonian with monodimensional, odd and discontinuous magnetic field.
We show in particular that the lowest energy is higher in dimension 3.


title:
Mineralogy, reflectance spectra, and physical properties of the
  Chelyabinsk LL5 chondrite, insight into shock induced changes in asteroid
  regoliths

abstract:
  The mineralogy and physical properties of Chelyabinsk meteorites (fall,
February 15, 2013) are presented. Three types of meteorite material are
present, described as the light-colored, dark-colored, and impact-melt
lithologies. All are of LL5 composition with the impact-melt lithology being
close to whole-rock melt and the dark-colored lithology being shock-darkened
due to partial melting of iron metal and sulfides. This enables us to study the
effect of increasing shock on material with identical composition and origin.
Based on the magnetic susceptibility, the Chelyabinsk meteorites are richer in
metallic iron as compared to other LL chondrites. The measured bulk and grain
densities and the porosity closely resemble other LL chondrites. Shock
darkening does not have a significant effect on the material physical
properties, but causes a decrease of reflectance and decrease in silicate
absorption bands in the reflectance spectra. This is similar to the space
weathering effects observed on asteroids. However, compared to space weathered
materials, there is a negligible to minor slope change observed in impact-melt
and shock-darkened meteorite spectra. Thus, it is possible that some dark
asteroids with invisible silicate absorption bands may be composed of
relatively fresh shock-darkened chondritic material.


title: Flows driven by Banach space-valued rough paths

abstract:
  We show in this note how the machinery of C^1-approximate flows devised in
the work "Flows driven by rough paths", and applied there to reprove and extend
most of the results on Banach space-valued rough differential equations driven
by a finite dimensional rough path, can be used to deal with rough differential
equations driven by an infinite dimensional Banach space-valued weak geometric
Holder p-rough paths, for any p>2, giving back Lyons' theory in its full force
in a simple way.


title: Plasmons due to the interplay of Dirac and Schr\"odinger fermions

abstract:
  We study the interplay between Dirac and Schr\"odinger fermions in the
polarization properties of a two-dimensional electron gas (2DEG). Specifically,
we analyze the low-energy sector of narrow-gap semiconductors described by a
two-band Kane model. In the context of quantum spin Hall insulators,
particularly, in Hg(Cd)Te quantum wells, this model is named
Bernevig-Hughes-Zhang model. Interestingly, it describes electrons with
intermediate properties between Dirac and Schr\"odinger fermions. We calculate
the dynamical dielectric function of such a model at zero temperature within
random phase approximation. Surprisingly, plasmon resonances are found in the
intrinsic (undoped) limit, whereas they are absent - in that limit - in
graphene as well as ordinary 2DEGs. Additionally, we demonstrate that the
optical conductivity offers a quantitative way to identify the topological
phase of Hg(Cd)Te quantum wells from a bulk measurement.


title:
Orbital-selective metal-insulator transition and gap formation above Tc
  in superconducting Rb1-xFe2-ySe2

abstract:
  We report on a hierarchy of temperatures Tc < Tgap < Tmet in superconducting
Rb1-xFe2-ySe2 observed by THz spectroscopy. Above Tmet = 90 K the material
reveals semiconducting characteristics. Below Tmet a coherent metallic THz
response emerges. This metal-to-insulator type, orbital selective transition is
clearly indicated by an isosbestic point in the temperature dependence of the
optical conductivity and dielectric constant at THz-frequencies. At Tgap = 61 K
a gap opens in the THz regime and then the superconducting transition occurs at
Tc = 32 K. This sequence of temperatures seems to reflect a corresponding
hierarchy of the electronic correlations in the different bands.


title: Decomposition of an abstract Uryson operator

abstract:
  We consider the space of abstract Uryson operators firstly introduced in [9].
We obtain the formulas for band projections on the band generated by increasing
set of a positive Uryson operators and on the band generated one-dimensional
abstract Uryson operators. We also calculate the laterally continuous part of a
abstract Uryson operator.


title:
A renormalization group analysis of the Hill model and its HEIDI
  extension

abstract:
  The parameter space of the simplest extension of the standard model, is
studied in the light of the 125 GeV Higgs boson discovery. The Hill model
extends the scalar sector of the standard model with a real singlet, that mixes
with the SM Higgs boson. The two-loop SM renormalization group equations are
completed with the one-loop Hill equations. Stability up to the Planck scale is
possible without tension with the other parameters. An extension with more
singlet fields, in particular a higher dimensional (HEIDI) field is presented.


title:
Numerical simulations of composite supernova remnants for small $\sigma$
  pulsar wind nebulae

abstract:
  Composite supernova remnants consist of a pulsar wind nebula located inside a
shell-type remnant. The presence of a shell has implications on the evolution
of the nebula, although the converse is generally not true. The purpose of this
paper is two-fold. The first aim is to determine the effect of the pulsar's
initial luminosity and spin-down rate, the supernova ejecta mass, and density
of the interstellar medium on the evolution of a spherically-symmetric,
composite supernova remnant expanding into a homogeneous medium. The second aim
is to investigate the evolution of the magnetic field in the pulsar wind nebula
when the the composite remnant expands into a non-uniform interstellar medium.
The Euler conservation equations for inviscid flow, together with the
magnetohydrodynamic induction law in the kinematic limit, are solved
numerically for a number of scenarios where the ratio of magnetic to particle
energy is $\sigma < 0.01$. The simulations in the first part of the paper is
solved in a one-dimensional configuration. In the second part of the paper, the
effect of an inhomogeneous medium on the evolution is studied using a
two-dimensional, axis-symmetric configuration.


title:
Study of the phase transition in polycrystalline
  (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3

abstract:
  Polycrystalline sample of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 was
obtained by means of a conventional ceramic technology. The dielectric
measurements were performed depending on temperature and frequency of electric
measuring field. The character of the phase transitions of
(Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 ceramics strongly depends on the
presence of Pb in the sample. The obtained results pointed out the diffused
character of phase transition. The temperature dependence of the dielectric
properties showed that the phase transition from the paraelectric phase to
ferroelectric one takes place at the same temperature (T_{m}=367 K). It does
not depend on the frequency of the measuring electric field. A change of the
value of the parameter \gamma takes place in the paraelectric phase.


title:
Hysteretic phenomena in a 2DEG in quantum Hall effect regime studied in
  a transport experiment

abstract:
  We investigated experimentally non-equilibrium state of a two-dimensional
electron gas (2DEG) in the quantum Hall effect (QHE) regime, studying the
hysteresis of magnetoresistance of a 2DEG with a constriction. The large
amplitude of the hysteresis enabled us to make the consistent phenomenological
description of the hysteresis. We studied the dependence on the magnetic field
sweep prehistory (minor loop measurements), recovered the anhysteretic curve,
and studied the time dependence of the magnetoresistance. We showed that the
hysteresis of magnetoresistance of a 2DEG in the QHE regime has significant
phenomenological similarities with the hysteresis of magnetization of
ferromagnetic materials, showing multistability, jumps of relaxation, and
having the anhysteretic curve. Nevertheless, we revealed the crucial
difference, manifested itself in an unusual inverted (anti-coercive) behavior
of the magnetoresistance hysteresis. The time relaxation of the hysteresis has
fast and slow regimes, similar to that of non-equilibrium magnetization of a
2DEG in QHE regime pointing to their common origin. We studied the dependence
of the hysteresis loop area on the lithographic width of the constriction and
found the threshold value of width $\sim$1.35 $\mu$m beyond which the
hysteresis is not observed. This points to the edge nature of the
non-equilibrium currents (NECs) and allows us to determine the width of the
NECs area ($\sim$0.5 $\mu$m). We suggest the qualitative picture of the
observed hysteresis, based on non-equilibrium redistribution of the electrons
among the Landau level states and assuming huge imbalance between the
population of bulk and edge electronic states.


title: Generalized Spectral Characterization of Graphs: Revisited

abstract:
  A graph $G$ is said to be \textit{determined by its generalized spectrum}
(DGS for short) if for any graph $H$, $H$ and $G$ are cospectral with
cospectral complements implies that $H$ is isomorphic to $G$. In \cite{WX,WX1},
Wang and Xu gave some methods for determining whether a family of graphs are
DGS. In this paper, we shall review some of the old results and present some
new ones along this line of research.


title: Many-particle quantum graphs and Bose-Einstein condensation

abstract:
  In this paper we propose quantum graphs as one-dimensional models with a
complex topology to study Bose-Einstein condensation and phase transitions in a
rigorous way. We fist investigate non-interacting many-particle systems on
quantum graphs and provide a complete classification of systems that exhibit
Bose-Einstein condensation. We then consider models of interacting particles
that can be regarded as a generalisation of the well-known Tonks-Girardeau gas.
Here our principal result is that no phase transitions occur in bosonic systems
with repulsive hardcore interactions, indicating an absence of Bose-Einstein
condensation.


title:
Comparison of polarization switching in ferroelectric TGS and relaxor
  SBN crystals

abstract:
  The comparative experimental analysis of polarization reversal kinetics in
conventional homogeneous triglycine sulfate ((NH_{2}CH_{2}COOH)_{3} \cdot
H_{2}SO_{4}; TGS) and relaxor strontium barium niobate
(Sr_{0.61}Ba_{0.39}Nb_{2}O_{6}; SBN) crystals have been performed in a broad
range of measurement conditions. The experimental data have been collected from
microscopic observation of the domain structure, switching current and D-E
hysteresis loop registration. The hysteresis loop and dielectric spectra have a
strong link to the configuration of ferroelectric microdomains. The domain
structure dynamics was examined by the nematic liquid crystal (NLC) method.


title: Electrophysical properties of PMN-PT-PS-PFN:Li ceramics

abstract:
  We present the technology of obtaining and the electrophysical properties of
a multicomponent material 0.61PMN-0.20PT-0.09PS-0.1PFN:Li (PMN-PT-PS-PFN:Li).
The addition of PFN into PMN-PT decreases the temperature of final sintering
which is very important during technological process (addition of Li decreases
electric conductivity of PFN). Addition of PS i.e., PbSnO_3 (which is unstable
in ceramic form) permits to shift the temperature of the maximum of dielectric
permittivity. One-step method of obtaining ceramic samples from oxides and
carbonates has been used. XRD, microstructure, scanning calorimetry
measurements and the main dielectric, ferroelectric and electromechanical
properties have been investigated for the obtained samples.


title:
Cosmological simulations in MOND: the cluster scale halo mass function
  with light sterile neutrinos

abstract:
  We use our Modified Newtonian Dynamics (MOND) cosmological particle-mesh
N-body code to investigate the feasibility of structure formation in a
framework involving MOND and light sterile neutrinos in the mass range 11 - 300
eV: always assuming that \Omega_{\nu_s}=0.225 for H_o=72 \kms Mpc^{-1}. We run
a suite of simulations with variants on the expansion history, cosmological
variation of the MOND acceleration constant, different normalisations of the
power spectrum of the initial perturbations and interpolating functions. Using
various box sizes, but typically with ones of length 256 Mpc/h, we compare our
simulated halo mass functions with observed cluster mass functions and show
that (i) the sterile neutrino mass must be larger than 30 eV to account for the
low mass (M_{200}<10^{14.6} solar masses) clusters of galaxies in MOND and (ii)
regardless of sterile neutrino mass or any of the variations we mentioned
above, it is not possible to form the correct number of high mass
(M_{200}>10^{15.1} solar masses) clusters of galaxies: there is always a
considerable over production. This means that the ansatz of considering the
weak-field limit of MOND together with a component of light sterile neutrinos
to form structure from z ~ 200 fails. If MOND is the correct description of
weak-field gravitational dynamics, it could mean that subtle effects of the
additional fields in covariant theories of MOND render the ansatz inaccurate,
or that the gravity generated by light sterile neutrinos (or by similar hot
dark matter particles) is different from that generated by the baryons.


title: Lower bound in the Roth theorem for amenable groups

abstract:
  Let $T_1$, $T_2$ be two commuting probability measure-preserving actions of a
countable amenable group such that the group spanned by these actions acts
ergodically. We show that $\mu(A\cap T_1^g A\cap T_1^g T_2^g A) >
\mu(A)^4-{\epsilon}$ on a syndetic set for any measurable set $A$ and any
$\epsilon>0$. The proof uses the concept of a sated system introduced by
Austin.


title:
Brauer group of moduli of torsors under Bruhat-Tits group scheme
  $\mathcal{G}$ over a curve

abstract:
  Let $X$ be a smooth projective curve over the complex numbers. We compute the
Brauer group of the moduli stack of Bruhat-Tits group scheme
$\mathcal{G}$-torsors on $X$. When $g(X) \geq 3$ we compute the Brauer group of
the regularly stable locus of the coarse moduli space of semi-stable
$\mathcal{G}$-torsors.


title: Uniformly finite homology and amenable groups

abstract:
  Uniformly finite homology is a coarse invariant for metric spaces; in
particular, it is a quasi-isometry invariant for finitely generated groups. In
this article, we study uniformly finite homology of finitely generated amenable
groups and prove that it is infinite dimensional in many cases. The main idea
is to use different transfer maps to distinguish between classes in uniformly
finite homology. Furthermore we show that there are infinitely many classes in
degree zero that cannot be detected by means.


title:
Many-body corrections to ESR energy and spin-wave excitations in
  two-dimensional systems with Bychkov-Rashba spin splitting

abstract:
  We report effects of electron-electron (\emph{e-e}) interaction on electron
spin resonance (ESR) in perpendicular magnetic field in two-dimensional (2D)
systems with Bychkov-Rashba spin splitting induced by spin-orbit interaction
(SOI) and structural inversion asymmetry (SIA). Using the Hartree-Fock
approximation, we demonstrate that the SIA results in non-zero many-body
corrections to the ESR energy and the energy of spin wave excitations. We
discover that the \emph{e-e} interaction in 2D systems with SIA not only can
enhance the ESR energy but can also lead to the ESR energy reduction. The
magnitude of this effect exhibits remarkable features in a wide range of
parameters relevant to experiment: it is found to be rather sensitive to the
sign of g-factor and the filling factor of Landau levels $\nu$. We derive
analytical expressions for many-body corrections to ESR energy and the
dispersion of spin wave excitations for the case of $\nu\leq 2$. We have found
out that \emph{e-e} interaction does not affect the ESR energy in the case of
filling of the lowest Landau level ($\nu\leq 1$) in 2D systems with positive
g-factors even at arbitrarily large values of Bychkov-Rashba constant. The
many-body renormalization of ESR energy in the case of fractional Quantum Hall
effect is also discussed.


title:
The Herschel-PACS photometer calibration: Point-source flux calibration
  for scan maps

abstract:
  This paper provides an overview of the PACS photometer flux calibration
concept, in particular for the principal observation mode, the scan map. The
absolute flux calibration is tied to the photospheric models of five fiducial
stellar standards (alpha Boo, alpha Cet, alpha Tau, beta And, gamma Dra). The
data processing steps to arrive at a consistent and homogeneous calibration are
outlined. In the current state the relative photometric accuracy is around 2%
in all bands. Starting from the present calibration status, the
characterization and correction for instrumental effects affecting the relative
calibration accuracy is described and an outlook for the final achievable
calibration numbers is given. After including all the correction for the
instrumental effects, the relative photometric calibration accuracy
(repeatability) will be as good as 0.5% in the blue and green band and 2% in
the red band. This excellent calibration starts to reveal possible
inconsistencies between the models of the K-type and the M-type stellar
calibrators. The absolute calibration accuracy is therefore mainly limited by
the 5% uncertainty of the celestial standard models in all three bands. The
PACS bolometer response was extremely stable over the entire Herschel mission
and a single, time-independent response calibration file is sufficient for the
processing and calibration of the science observations. The dedicated
measurements of the internal calibration sources were needed only to
characterize secondary effects. No aging effects of the bolometer or the
filters have been found. Also, we found no signs of filter leaks. The PACS
photometric system is very well characterized with a constant energy spectrum
nu*Fnu = lambda*Flambda = const as a reference. Colour corrections for a wide
range of sources SEDs are determined and tabulated.


title:
3D maps of the local ISM from inversion of individual color excess
  measurements

abstract:
  Three-dimensional (3D) maps of the Galactic interstellar matter (ISM) are a
potential tool of wide use, however accurate and detailed maps are still
lacking. One of the ways to construct the maps is to invert individual
distance-limited ISM measurements, a method we have here applied to
measurements of stellar color excess in the optical. We have assembled color
excess data together with the associated parallax or photometric distances to
constitute a catalog of ~ 23,000 sightlines for stars within 2.5 kpc. The
photometric data are taken from Stromgren catalogs, the Geneva photometric
database, and the Geneva-Copenhagen survey. We also included extinctions
derived towards open clusters. We applied, to this color excess dataset, an
inversion method based on a regularized Bayesian approach, previously used for
mapping at closer distances. We show the dust spatial distribution resulting
from the inversion by means of planar cuts through the differential opacity 3D
distribution, and by means of 2D maps of the integrated opacity from the Sun up
to various distances. The mapping assigns locations to the nearby dense clouds
and represents their distribution at the spatial resolution that is allowed by
the dataset properties, i.e. of the order of ~10 pc close to the Sun and
increasing to ~100 pc beyond 1 kpc. Biases towards nearby and/or weakly
extincted stars make this dataset particularly appropriate to map the local and
neighboring cavities, and to locate faint, extended nearby clouds, both goals
that are difficult or impossible with other mapping methods. The new maps
reveal a ~1 kpc wide empty region in the third quadrant in the continuation of
the so-called CMa tunnel of the Local Cavity, a cavity that we identify as the
Superbubble GSH238+00+09 detected in radio emission maps and that is found to
be bounded by the Orion and Vela clouds.


title:
Quasi-Periodic Oscillations and energy spectra from the two brightest
  Ultra-Luminous X-ray sources in M82

abstract:
  Ultra-Luminous X-ray sources are thought to be accreting black holes that
might host Intermediate Mass Black Holes (IMBH), proposed to exist by
theoretical studies, even though a firm detection (as a class) is still
missing. The brightest ULX in M82 (M82 X-1) is probably one of the best
candidates to host an IMBH. In this work we analyzed the data of the recent
release of observations obtained from M82 X-1 taken by XMM-Newton. We performed
a study of the timing and spectral properties of the source. We report on the
detection of (46+-2) mHz Quasi-Periodic Oscillations (QPOs) in the power
density spectra of two observations. A comparison of the frequency of these
high-frequency QPOs with previous detections supports the 1:2:3 frequency
distribution as suggested in other studies. We discuss the implications if the
(46+-2) mHz QPO detected in M82 X-1 is the fundamental harmonic, in analogy
with the High-Frequency QPOs observed in black hole binaries. For one of the
observations we have detected for the first time a QPO at 8 mHz (albeit at a
low significance), that coincides with a hardening of the spectrum. We suggest
that the QPO is a milli-hertz QPO originating from the close-by transient ULX
M82 X-2, with analogies to the Low-Frequency QPOs observed in black hole
binaries.


title: Weighted energy estimates for $p$-evolution equations

abstract:
  We prove energy estimates for linear $p$-evolution equations in weighted
Sobolev spaces under suitable assumptions on the behavior at infinity of the
coefficients with respect to the space variables. As a consequence we obtain
well posedness for the related Cauchy problem in the Schwartz spaces
$\mathcal{S}$ and $\mathcal{S}'$.


title: An Effective Ratner Equidistribution Result for ASL(2,R)

abstract:
  Let G=ASL(2,R) be the affine special linear group of the plane, and set
Gamma=ASL(2,Z). We prove a polynomially effective asymptotic equidistribution
result for the orbits of a 1-dimensional, non-horospherical unipotent flow on
Gamma\G.


title:
Alpha-Particle Clustering from Expanding Self-Conjugate Nuclei within
  the Hartree-Fock-Bogoliubov Approach

abstract:
  The nuclear equation of state is explored with the constrained HFB approach
for self conjugate nuclei. It is found that beyond a certain low, more or less
universal density, those nuclei spontaneously cluster into A/4 alpha particles
with A the nucleon number. The energy at the threshold density increases
linearly with the number of alpha particles as does the experimental threshold
energy. Taking off the spurious c.o.m. energy of each alpha particle almost
gives agreement between theory and experiment. The implications of these
results with respect to alpha clustering and the nuclear EOS at low density are
discussed.


title: Control of the socio-economic systems using herding interactions

abstract:
  Collective behavior of the complex socio-economic systems is heavily
influenced by the herding, group, behavior of individuals. The importance of
the herding behavior may enable the control of the collective behavior of the
individuals. In this contribution we consider a simple agent-based herding
model modified to include agents with controlled state. We show that in certain
case even the smallest fixed number of the controlled agents might be enough to
control the behavior of a very large system.


title:
Minisuperspace Canonical Quantization of the Reissner-Nordstrom Black
  Hole via Conditional Symmetries

abstract:
  We use the conditional symmetry approach to study the $r$-evolution of a
minisuperspace spherically symmetric model both at the classical and quantum
level. After integration of the coordinates $t$, $\theta$ and $\phi$ in the
gravitational plus electromagnetic action the configuration space dependent
dynamical variables turn out to correspond to the $r$-dependent metric
functions and the electrostatic field. In the context of the formalism for
constrained systems (Dirac - Bergmann, ADM) with respect to the radial
coordinate $r$, we set up a point-like reparameterization invariant Lagrangian.
It is seen that, in the constant potential parametrization of the lapse, the
corresponding minisuperspace is a Lorentzian three-dimensional flat manifold
which obviously admits six Killing vector fields plus a homothetic one. The
weakly vanishing $r$-Hamiltonian guarantees that the phase space quantities
associated to the six Killing fields are linear holonomic integrals of motion.
The homothetic field provides one more rheonomic integral of motion. These
seven integrals are shown to comprise the entire classical solution space, i.e.
the space-time of a Reissner-Nordstr\"om black hole, the $r$-reparametrization
invariance since one dependent variable remains unfixed, and the two quadratic
relations satisfied by the integration constants. We then quantize the model
using the quantum analogues of the classical conditional symmetries, and show
that the existence of such symmetries yields solutions to the Wheeler-DeWitt
equation which, as a semiclassical analysis shows, exhibit a good correlation
with the classical regime. We use the resulting wave functions to investigate
the possibility of removing the classical singularities.


title:
Dynamics of the modified Kibble-\.Zurek mechanism in antiferromagnetic
  spin-1 condensates

abstract:
  We investigate the dynamics and outcome of a quantum phase transition from an
antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein
condensate of ultracold atoms. We explicitly demonstrate double universality in
dynamics within experiments with various quench time. Furthermore, we show that
spin domains created in the nonequilibrium transition constitute a set of
mutually incoherent quasicondensates. The quasicondensates appear to be
positioned in a semi-regular fashion, which is a result of the conservation of
local magnetization during the post-selection dynamics.


title:
Reflected Generalized Beta Inverse Weibull Distribution: definition and
  properties

abstract:
  In this paper we study a broad class of distribution functions which is
defined by means of reflected generalized beta distribution. This class
includes that of Beta-generated distribution as a special case. In particular,
we use this class to extend the Inverse Weibull distribution in order to obtain
the Reflected Generalized Beta Inverse Weibull Distribution.For this new
distribution, moments, entropy, order statistics and a reliability measure are
derived. The link between the Inverse Weibull and the Dagum distribution is
generalized. Then the maximum likelihood estimators of the parameters are
examined and the observed Fisher information matrix provided. Finally, the
usefulness of the model is illustrated by means of an application to real data.


title: Analysis of Scientific Cloud Computing requirements

abstract:
  While the requirements of enterprise and web applications have driven the
development of Cloud computing, some of its key features, such as customized
environments and rapid elasticity, could also benefit scientific applications.
However, neither virtualization techniques nor Cloud-like access to resources
is common in scientific computing centers due to the negative perception of the
impact that virtualization techniques introduce.
  In this paper we discuss the feasibility of the IaaS cloud model to satisfy
some of the computational science requirements and the main drawbacks that need
to be addressed by cloud resource providers so that the maximum benefit can be
obtained from a given cloud infrastructure.


title: Magnetic field generation in galactic molecular clouds

abstract:
  We investigate the magnetic field which is generated by turbulent motions of
a weakly ionized gas. Galactic molecular clouds give us an example of such a
medium. As in the Kazantsev-Kraichnan model we assume a medium to be
homogeneous and a neutral gas velocity field to be isotropic and
delta-correlated in time. We take into consideration the presence of a mean
magnetic field, which defines a preferred direction in space and eliminates
isotropy of magnetic field correlators. Evolution equations for the anisotropic
correlation function are derived. Isotropic cases with zero mean magnetic field
as well as with small mean magnetic field are investigated. It is shown that
stationary bounded solutions exist only in the presence of the mean magnetic
field for the Kolmogorov neutral gas turbulence. The dependence of the magnetic
field fluctuations amplitude on the mean field is calculated. The stationary
anisotropic solution for the magnetic turbulence is also obtained for large
values of the mean magnetic field.


title: Bayesian hierarchical modeling of extreme hourly precipitation in Norway

abstract:
  Spatial maps of extreme precipitation are a critical component of flood
estimation in hydrological modeling, as well as in the planning and design of
important infrastructure. This is particularly relevant in countries such as
Norway that have a high density of hydrological power generating facilities and
are exposed to significant risk of infrastructure damage due to flooding. In
this work, we estimate a spatially coherent map of the distribution of extreme
hourly precipitation in Norway, in terms of return levels, by linking
generalized extreme value (GEV) distributions with latent Gaussian fields in a
Bayesian hierarchical model. Generalized linear models on the parameters of the
GEV distribution are able to incorporate location-specific geographic and
meteorological information and thereby accommodate these effects on extreme
precipitation. A Gaussian field on the GEV parameters captures additional
unexplained spatial heterogeneity and overcomes the sparse grid on which
observations are collected. We conduct an extensive analysis of the factors
that affect the GEV parameters and show that our combination is able to
appropriately characterize both the spatial variability of the distribution of
extreme hourly precipitation in Norway, and the associated uncertainty in these
estimates.


title:
Sub-arcsec Observations of NGC 7538 IRS 1: Continuum Distribution and
  Dynamics of Molecular Gas

abstract:
  We report new results based on the analysis of the SMA and CARMA observations
of NGC 7538\,IRS\,1 at 1.3 and 3.4 mm with sub-arcsec resolutions. With angular
resolutions $\sim$ 0\farcs7, the SMA and CARMA observations show that the
continuum emission at 1.3 and 3.4 mm from the hyper-compact \ion{H}{2} region
IRS\,1 is dominated by a compact source with a tail-like extended structure to
the southwest of IRS\,1. With a CARMA B-array image at 1.3 mm convolved to
0\farcs1, we resolve the hyper-compact \ion{H}{2} region into two components:
an unresolved hyper-compact core, and a north-south extension with linear sizes
of $<270$ AU and $\sim$2000 AU, respectively. The fine structure observed with
CARMA is in good agreement with the previous VLA results at centimeter
wavelengths, suggesting that the hyper-compact \ion{H}{2} region at the center
of IRS\,1 is associated with an ionized bipolar outflow. We image the molecular
lines OCS(19-18) and CH$_3$CN(12-11) as well as $^{13}$CO(2-1) surrounding
IRS\,1, showing a velocity gradient along the southwest-northeast direction.
The spectral line profiles in $^{13}$CO(2-1), CO(2-1), and HCN(1-0) observed
toward IRS\,1 show broad redshifted absorption, providing evidence for gas
infall with rates in the range of $3-10\times10^{-3}$ M$_\odot$ yr$^{-1}$
inferred from our observations.


title:
The geometry of planar $p$-harmonic mappings: convexity, level curves
  and the isoperimetric inequality

abstract:
  We discuss various representations of planar $p$-harmonic systems of
equations and their solutions. For coordinate functions of $p$-harmonic maps we
analyze signs of their Hessians, the Gauss curvature of $p$-harmonic surfaces,
the length of level curves as well as we discuss curves of steepest descent.
The isoperimetric inequality for the level curves of coordinate functions of
planar $p$-harmonic maps is proven. Our main techniques involve relations
between quasiregular maps and planar PDEs. We generalize some results due to P.
Lindqvist, G. Alessandrini, G. Talenti and P. Laurence.


title:
Constraining ALPs with linear and circular polarisation measurements of
  quasar light

abstract:
  We discuss the constraints derived on the mixing of photons with light
pseudoscalars using the distributions of good-quality linear and circular
polarisation measurements of light from the least polarised classes of quasars.
We also provide the dependence of our limit on the average electron density in
the local supercluster for nearly massless particles.


title: A Simple FPTAS for Counting Edge Covers

abstract:
  An edge cover of a graph is a set of edges such that every vertex has at
least an adjacent edge in it. Previously, approximation algorithm for counting
edge covers is only known for 3 regular graphs and it is randomized. We design
a very simple deterministic fully polynomial-time approximation scheme (FPTAS)
for counting the number of edge covers for any graph. Our main technique is
correlation decay, which is a powerful tool to design FPTAS for counting
problems. In order to get FPTAS for general graphs without degree bound, we
make use of a stronger notion called computationally efficient correlation
decay, which is introduced in [Li, Lu, Yin SODA 2012].


title: Optimal parallel quantum query algorithms

abstract:
  We study the complexity of quantum query algorithms that make p queries in
parallel in each timestep. This model is in part motivated by the fact that
decoherence times of qubits are typically small, so it makes sense to
parallelize quantum algorithms as much as possible. We show tight bounds for a
number of problems, specifically Theta((n/p)^{2/3}) p-parallel queries for
element distinctness and Theta((n/p)^{k/(k+1)} for k-sum. Our upper bounds are
obtained by parallelized quantum walk algorithms, and our lower bounds are
based on a relatively small modification of the adversary lower bound method,
combined with recent results of Belovs et al. on learning graphs. We also prove
some general bounds, in particular that quantum and classical p-parallel
complexity are polynomially related for all total functions f when p is small
compared to f's block sensitivity.


title:
Efficient Gate-tunable light-emitting device made of defective boron
  nitride nanotubes: from ultraviolet to the visible

abstract:
  Boron nitride is a promising material for nanotechnology applications due to
its two-dimensional graphene-like, insulating, and highly-resistant structure.
Recently it has received a lot of attention as a substrate to grow and isolate
graphene as well as for its intrinsic UV lasing response. Similar to carbon,
one-dimensional boron nitride nanotubes (BNNTs) have been theoretically
predicted and later synthesised. Here we use first principles simulations to
unambiguously demonstrate that i) BN nanotubes inherit the highly efficient UV
luminescence of hexagonal BN; ii) the application of an external perpendicular
field closes the electronic gap keeping the UV lasing with lower yield; iii)
defects in BNNTS are responsible for tunable light emission from the UV to the
visible controlled by a transverse electric field (TEF). Our present findings
pave the road towards optoelectronic applications of BN-nanotube-based devices
that are simple to implement because they do not require any special doping or
complex growth.


title: Functional renormalization group study of the Anderson--Holstein model

abstract:
  We present a comprehensive study of the spectral and transport properties in
the Anderson--Holstein model both in and out of equilibrium using the
functional renormalization group (FRG). We show how the previously established
machinery of Matsubara and Keldysh FRG can be extended to include the local
phonon mode. Based on the analysis of spectral properties in equilibrium we
identify different regimes depending on the strength of the electron--phonon
interaction and the frequency of the phonon mode. We supplement these
considerations with analytical results from the Kondo model. We also calculate
the non-linear differential conductance through the Anderson--Holstein quantum
dot and find clear signatures of the presence of the phonon mode.


title: Combinatorial categories and permutation groups

abstract:
  The regular objects in various categories, such as maps, hypermaps or
covering spaces, can be identified with the normal subgroups N of a given group
\Gamma, with quotient group isomorphic to \Gamma/N. It is shown how to
enumerate such objects with a given finite automorphism group G, how to
represent them all as quotients of a single regular object U(G), and how they
are acted on by the outer automorphism group of \Gamma. Examples constructed
include kaleidoscopic maps with trinity symmetry.


title: The Catalan simplicial set

abstract:
  The Catalan numbers are well-known to be the answer to many different
counting problems, and so there are many different families of sets whose
cardinalities are the Catalan numbers. We show how such a family can be given
the structure of a simplicial set. We show how the low-dimensional parts of
this simplicial set classify, in a precise sense, the structures of monoid and
of monoidal category. This involves aspects of combinatorics, algebraic
topology, quantum groups, logic, and category theory.


title:
An attempt to obtain Bi_{4}Ti_{3}O_{12}-PVC textured ceramics-polymer
  composites

abstract:
  Bi_{4}Ti_{3}O_{12}-PVC composites were fabricated. Ceramics powders of
bismuth titanate were prepared by the sol-gel method using bismuth nitrate
pentahydrate Bi(NO_{3})_{3} \cdot 5H_{2}O and tetrabutyl titanate
Ti(CH_{3}(CH_{2})_{3}O)_{4} as precursors. The Bi_{4}Ti_{3}O_{12}-PVC
composites were fabricated from ceramics powders and polymer powders by
hot-pressing method.


title: The Measurable Q Factor and Observable Energies of Radiating Structures

abstract:
  New expressions are derived to calculate the Q factor of a radiating device.
The resulting relations link Q based on the frequency change of the input
impedance at the input port (Qx, Qz) with expressions based solely on the
current distribution on an radiating device. The question of which energies of
a radiating system are observable is reviewed, and then the proposed Q factor
as defined in this paper is physical. The derivation is based on potential
theory rather than fields. This approach hence automatically eliminates all
divergent integrals associated with electromagnetic energies in infinite space.
  The new formulas allow us to study the radiation Q factor for antennas
without feeding (through e.g. Characteristic Modes) as well as fed by an
arbitrary number of ports. The new technique can easily be implemented in any
numerical software dealing with current densities. To present the merits of
proposed technique, three canonical antennas are studied. Numerical examples
show excellent agreement between the measurable Qz derived from input impedance
and the new expressions.


title: Device-to-Device Data Storage for Mobile Cellular Systems

abstract:
  As an alternative to downloading content from a cellular access network,
mobile devices could be used to store data files and distribute them through
device-to-device (D2D) communication. We consider a D2D-based storage community
that is comprised of mobile users. Assuming that transmitting data from a base
station to a mobile user consumes more energy than transmitting data between
two mobile users, we show that it can be beneficial to use redundant storage to
ensure that data files stay available to the community even if some of the
storing users leave the network. We derive a tractable closed-form equation
stating when redundancy should be used in order to minimize the expected energy
consumption of data retrieval. We find that replication is the preferred method
of adding redundancy as opposed to regenerating codes. Our findings are
verified by computer simulations.


title: Transducers with origin information

abstract:
  Call a string-to-string transducer regular if it can be realised by one of
the following equivalent models: mso transductions, two-way deterministic
automata with output, and streaming transducers with registers. This paper
proposes to treat origin information as part of the semantics of a regular
string-to-string transducer. With such semantics, the model admits a
machine-independent characterisation, Angluin-style learning in polynomial
time, as well as effective characterisations of natural subclasses such as
one-way transducers or first-order definable transducers.


title: A generalized Hilbert matrix acting on Hardy spaces

abstract:
  If $\mu $ is a positive Borel measure on the interval $[0, 1)$, the Hankel
matrix $\mathcal H_\mu =(\mu_{n,k})_{n,k\ge 0}$ with entries
$\mu_{n,k}=\int_{[0,1)}t^{n+k}\,d\mu(t)$ induces formally the operator
$$\mathcal{H}_\mu
(f)(z)=\sum_{n=0}^{\infty}\left(\sum_{k=0}^{\infty}\mu_{n,k}{a_k}\right)z^n$$
on the space of all analytic functions $f(z)=\sum_{k=0}^\infty a_kz^k$, in the
unit disc $\mathbb{D} $. In this paper we describe those measures $\mu$ for
which $\mathcal{H}_\mu $ is a bounded (compact) operator from $H^p$ into $H^q$,
$0<p,q<\infty $. We also characterize the measures $\mu $ for which $\mathcal
H_\mu $ lies in the Schatten class $S_p(H^2)$, $1<p<\infty$.


title:
Dielectric properties of PLZT-x/65/35 (2 \leqslant x \leqslant 13) under
  mechanical stress, electric field and temperature loading

abstract:
  We investigated the effect of uniaxial pressure (0-1000 bars) applied
parallely to the ac electric field on dielectric properties of PLZT-x/65/35 (2
\leqslant x \leqslant 13) ceramics. There was revealed a significant effect of
the external stress on these properties. The application of uniaxial pressure
leads to the change of the peak intensity of the electric permittivity
(\varepsilon), of the frequency dispersion as well as of the dielectric
hysteresis. The peak intensity $\varepsilon$ becomes diffused/sharpened and
shifts to a higher/lower temperatures with increasing the pressure. It was
concluded that the application of uniaxial pressure induces similar effects as
increasing the Ti ion concentration in PZT system. We interpreted our results
based on the domain switching processes under the action of combined
electromechanical loading.


title: Chemical capacitance proposed for manganite-based ceramics

abstract:
  The measured value of effective electric permittivity \varepsilon_{eff} of
several compounds, e.g., (BiNa)(MnNb)O_{3}, (BiPb)(MnNb)O_{3}, and BiMnO_{3}
increases from a value \approx 10-100 at the low temperature range (100-300 K)
up to the high value reaching the value 10^5 at high temperature range, e.g.,
500-800 K. Such features suggest the manifestation of thermally activated space
charge carriers, which effect the measured capacitance. The measured high-value
effective permittivity of several manganite compounds can be ascribed to the
chemical capacitance C_{\mu}=e^2\partial N_{i}/\partial \mu_{i} expressed in
terms of the chemical potential \mu. The chemical capacitance C_{\mu}^{(cb)} =
e^2 n_{C}/k_{B}T depends on temperature when the conduction electrons with
density n_{C} = N_{C} \exp(\mu_{n}- E_{C})/k_{B}T are considered. The
experimental results obtained for the manganite compounds, at high temperature
range, are discussed in the framework of the chemical capacitance model.
However, the measured capacitance dependence on geometrical factors is analysed
for BiMnO_{3} indicating that the non-homogeneous electrostatic capacitor model
is valid in 300-500 K range.


title: Noncompact dynamical symmetry of a spin-orbit coupled oscillator

abstract:
  We explain the finite as well as infinite degeneracy in the spectrum of a
particular system of spin-1/2 fermions with spin-orbit coupling in three
spatial dimensions. Starting from a generalized Runge-Lenz vector, we
explicitly construct a complete set of symmetry operators, which span a
noncompact SO(3,2) algebra. The degeneracy of the physical spectrum only
involves a particular, infinite, so called singleton representation. In the
branch where orbital and spin angular momentum are aligned the full
representation appears, constituting a 3D analogue of Landau levels.
Anti-aligning the spin leads to a finite degeneracy due to a truncation of the
singleton representation. We conclude the paper by constructing the spectrum
generating algebra of the problem.


title: Partition-Merge: Distributed Inference and Modularity Optimization

abstract:
  This paper presents a novel meta algorithm, Partition-Merge (PM), which takes
existing centralized algorithms for graph computation and makes them
distributed and faster. In a nutshell, PM divides the graph into small
subgraphs using our novel randomized partitioning scheme, runs the centralized
algorithm on each partition separately, and then stitches the resulting
solutions to produce a global solution. We demonstrate the efficiency of the PM
algorithm on two popular problems: computation of Maximum A Posteriori (MAP)
assignment in an arbitrary pairwise Markov Random Field (MRF), and modularity
optimization for community detection. We show that the resulting distributed
algorithms for these problems essentially run in time linear in the number of
nodes in the graph, and perform as well -- or even better -- than the original
centralized algorithm as long as the graph has geometric structures. Here we
say a graph has geometric structures, or polynomial growth property, when the
number of nodes within distance r of any given node grows no faster than a
polynomial function of r. More precisely, if the centralized algorithm is a
C-factor approximation with constant C \ge 1, the resulting distributed
algorithm is a (C+\delta)-factor approximation for any small \delta>0; but if
the centralized algorithm is a non-constant (e.g. logarithmic) factor
approximation, then the resulting distributed algorithm becomes a constant
factor approximation. For general graphs, we compute explicit bounds on the
loss of performance of the resulting distributed algorithm with respect to the
centralized algorithm.


title:
The ACS LCID project. IX. Imprints of the early Universe in the radial
  variation of the star formation history of dwarf galaxies

abstract:
  Based on Hubble Space Telescope observations from the Local Cosmology from
Isolated Dwarfs project, we present the star formation histories, as a function
of galactocentric radius, of four isolated Local Group dwarf galaxies: two dSph
galaxies, Cetus and Tucana, and two transition galaxies (dTrs), LGS-3 and
Phoenix. The oldest stellar populations of the dSphs and dTrs are, within the
uncertainties, coeval ($\sim 13 Gyr$) at all galactocentric radii. We find that
there are no significative differences between the four galaxies in the
fundamental properties (such as the normalized star formation rate or
age-metallicity relation) of their outer regions (radii greater than four
exponential scale lengths); at large radii, these galaxies consist exclusively
of old ($\geq 10.5 Gyr$) metal-poor stars. The duration of star formation in
the inner regions vary from galaxy to galaxy, and the extended central star
formation in the dTrs produces the dichotomy between dSph and dTr galaxy types.
The dTr galaxies show prominent radial stellar population gradients: the
centers of these galaxies host young ($\leq 1 Gyr$) populations while the age
of the last formation event increases smoothly with increasing radius. This
contrasts with the two dSph galaxies. Tucana shows a similar, but milder,
gradient, but no gradient in age is detected Cetus. For the three galaxies with
significant stellar population gradients, the exponential scale length
decreases with time. These results are in agreement with outside-in scenarios
of dwarf galaxy evolution, in which a quenching of the star formation toward
the center occurs as the galaxy runs out of gas in the outskirts.


title: Path-Based Distance for Street Map Comparison

abstract:
  Comparing two geometric graphs embedded in space is important in the field of
transportation network analysis. Given street maps of the same city collected
from different sources, researchers often need to know how and where they
differ. However, the majority of current graph comparison algorithms are based
on structural properties of graphs, such as their degree distribution or their
local connectivity properties, and do not consider their spatial embedding.
This ignores a key property of road networks since similarity of travel over
two road networks is intimately tied to the specific spatial embedding.
Likewise, many current street map comparison algorithms focus on the spatial
embeddings only and do not take structural properties into account, which makes
these algorithms insensitive to local connectivity properties and shortest path
similarities. We propose a new path-based distance measure to compare two
planar geometric graphs embedded in the plane. Our distance measure takes
structural as well as spatial properties into account by imposing a distance
measure between two road networks based on the Hausdorff distance between the
two sets of travel paths they represent. We show that this distance can be
approximated in polynomial time and that it preserves structural and spatial
properties of the graphs.


title: An Approach to Modularization of Distributed Systems

abstract:
  Modularization is an important architectural principle underlying many types
of complex systems. It tends to tame the complexity of systems, to facilitate
their management, and to enhance their flexibility with respect to evolution.
In software, modularization has been practiced and studied thoroughly in local,
i.e. non-distributed systems. But very little attention has been paid so far to
modularization in distributed systems. This is, in part, because distributed
systems are inherently modularized, in the sense that the internals of each
component of such a system is inaccessible to other components, thus satisfying
the Parnas hiding principle. It is, however, the thesis of this paper that
there is much to be gained by being able to treat groups of distributed
components as modules, called here distributed modules. And that besides the
conventional hiding principle, distributed modularization should provide
additional capabilities, which rarely, if ever, figure in conventional
modularized systems. These capabilities include, but are not limited to: the
ability to impose constraints on which kind of messages can be sent from a
given distributed-module to its outside; and the ability to create AOP-like
crosscutting modules. This paper introduces a model of modular distributed
system, orMDS, which satisfies such capabilities, and which is implemented via
the LGI middleware.


title: Taming Rogue waves in Vector BECs

abstract:
  Using Gauge transformation method, we generate rogue waves for the two
component Bose Einstein Condensates (BECs) governed by the symmetric coupled
Gross-Pitaevskii (GP) equations and study their dynamics. We also suggest a
mechanism to tame the rogue waves either by manipulating the scattering length
through Feshbach resonance or the trapping frequency, a new phenomenon not
witnessed in the domain of BEC, we believe that these results may have wider
ramifications in the management of rogons.


title:
Network analysis of the \'{I}slendinga s\"{o}gur - the Sagas of
  Icelanders

abstract:
  The \'{I}slendinga s\"{o}gur - or Sagas of Icelanders - constitute a
collection of medieval literature set in Iceland around the late 9th to early
11th centuries, the so-called Saga Age. They purport to describe events during
the period around the settlement of Iceland and the generations immediately
following and constitute an important element of world literature thanks to
their unique narrative style. Although their historicity is a matter of
scholarly debate, the narratives contain interwoven and overlapping plots
involving thousands of characters and interactions between them. Here we
perform a network analysis of the \'{I}slendinga s\"{o}gur in an attempt to
gather quantitative information on interrelationships between characters and to
compare saga society to other social networks.


title: Restricting unipotent characters in special orthogonal groups

abstract:
  For all prime powers q we restrict the unipotent characters of the special
orthogonal groups SO_5(q) and SO_7(q) to a maximal parabolic subgroup. We
determine all irreducible constituents of these restrictions for SO_5(q) and a
large part of the irreducible constituents for SO_7(q).


abstract:
  Berman's inequality is the key for establishing asymptotic properties of
maxima of Gaussian random sequences and supremum of Gaussian random fields.
This contribution shows that, asymptotically an extended version of Berman's
inequality can be established for randomly scaled Gaussian random vectors. Two
applications presented in this paper demonstrate the use of Berman's inequality
under random scaling.


title:
On the genericity of pseudo-Anosov braids II: conjugations to rigid
  braids

abstract:
  We prove that generic elements of braid groups are pseudo-Anosov, in the
following sense: in the Cayley graph of the braid group with n $\ge$ 3 strands,
with respect to Garside's generating set, we prove that the proportion of
pseudo-Anosov braids in the ball of radius l tends to 1 exponentially quickly
as l tends to infinity. Moreover, with a similar notion of genericity, we prove
that for generic pairs of elements of the braid group, the conjugacy search
problem can be solved in quadratic time. The idea behind both results is that
generic braids can be conjugated "easily" into a rigid braid.


title:
Joint Limiting Distribution of Minima and Maxima of Complete and
  Incomplete Samples of Stationary Sequences

abstract:
  In the seminal contribution [4] the joint weak convergence of maxima and
minima of weakly dependent stationary sequences is derived under some mild
asymptotic conditions. In this paper we address additionally the case of
incomplete samples assuming that the average proportion of incompleteness
converges in probability to some random variable. We show the joint weak
convergence of the maxima and minima of both complete and incomplete samples.
It turns out that for special cases, maxima and minima are asymptotically
independent.


title:
Near-infrared integral field spectroscopy of Massive Young Stellar
  Objects

abstract:
  We present medium resolution ($R\approx5300$) $K$-band integral field
spectroscopy of six MYSOs. The targets are selected from the RMS survey, and we
used the NIFS on the Gemini North telescope. The data show various spectral
line features including Br$\gamma$, CO, H$_2$, and \mbox{He\,{\sc i}}. The
Br$\gamma$ line is detected in emission in all objects with
$v_\mathrm{FWHM}\sim100$ -- 200 kms$^{-1}$. V645 Cyg shows a high-velocity
P-Cygni profile between -800 kms$^{-1}$ and -300 kms$^{-1}$. We performed
three-dimensional spectroastrometry to diagnose the circumstellar environment
in the vicinity of the central stars using the Br$\gamma$ line. We measured the
centroids of the velocity components with sub-mas precision. The centroids
allow us to discriminate the blueshifted and redshifted components in a roughly
east--west direction in both IRAS 18151--1208 and S106 in Br$\gamma$. This lies
almost perpendicular to observed larger scale outflows. We conclude, given the
widths of the lines and the orientation of the spectroastrometric signature,
that our results trace a disc wind in both IRAS 18151--1208 and S106. The CO
$\nu=2-0$ absorption lines at low $J$ transitions are detected in IRAS
18151--1208 and AFGL 2136. We analysed the velocity structure of the neutral
gas discs. In IRAS 18151--1208, the absorption centroids of the blueshifted and
redshifted components are separated in a direction of north-east to south-west,
nearly perpendicular to that of the larger scale $H_2$ jet. The
position-velocity relations of these objects can be reproduced with central
masses of 30 $M_{\sun}$ for IRAS 18151--1208 and 20 $M_{\sun}$ for AFGL 2136.
We also detect CO $\nu=2-0$ bandhead emission in IRAS 18151--1208, S106 and
V645 Cyg. The results can be fitted reasonably with a Keplerian rotation model,
with masses of 15, 20 and 20 $M_{\sun}$ respectively.


title: A Family of Steady Ricci Solitons and Ricci-flat Metrics

abstract:
  We produce new non-K\"ahler complete steady gradient Ricci solitons whose
asymptotics combine those of the Bryant solitons and the Hamilton cigar. We
also obtain a family of complete Ricci-flat metrics with asymptotically locally
conical asymptotics. Finally, we obtain numerical evidence for complete steady
soliton structures on the vector bundles whose distance sphere bundles are
respectively the twistor and ${\rm Sp}(1)$ bundles over quaternionic projective
space.


title: Change of measure up to a random time: Details

abstract:
  This paper extends results of Mortimer and Williams (1991) about changes of
probability measure up to a random time under the assumptions that all
martingales are continuous and that the random time avoids stopping times. We
consider locally absolutely continuous measure changes up to a random time,
changes of probability measure up to and after an honest time, and changes of
probability measure up to a pseudo-stopping time. Moreover, we apply our
results to construct a change of probability measure that is equivalent to the
enlargement formula and to build for a certain class of pseudo-stopping times a
class of measure changes that preserve the pseudo-stopping time property.
Furthermore, we study for a price process modeled by a continuous
semimartingale the stability of the No Free Lunch with Vanishing Risk (NFLVR)
property up to a random time, that avoids stopping times, in the progressively
enlarged filtration and provide sufficient conditions for this stability in
terms of the Az\'ema supermartingale.


title: Primitive stable closed hyperbolic 3-manifolds

abstract:
  We show that closed 3-manifolds with high Heegaard distance and bounded
subsurface Heegaard distance are primitive stable when they are regarded as
representations from the free group corresponding to the handlebody. This
implies that any point on the boundary of Schottky space can be approximated by
primitive stable representations corresponding to closed hyperbolic
3-manifolds.


title: T3B - An Experiment to measure the Time Structure of Hadronic Showers

abstract:
  The goal of the T3B experiment is the measurement of the time structure of
hadronic showers with nanosecond precision and high spatial resolution together
with the CALICE hadron calorimeter prototypes, with a focus on the use of
tungsten as absorber medium. The detector consists of a strip of 15
scintillator cells individually read out by silicon photomultipliers (SiPMs)
and fast oscilloscopes with a PC-controlled data acquisition system. The data
reconstruction uses an iterative subtraction technique which provides a
determination of the arrival time of each photon on the light sensor with
sub-nanosecond precision. The calibration is based on single photon-equivalent
dark pulses constantly recorded during data taking, automatically eliminating
the temperature dependence of the SiPM gain. In addition, a statistical
correction for SiPM afterpulsing is demonstrated. To provide the tools for a
comparison of T3B data with GEANT4 simulations, a digitization routine, which
accounts for the detector response to energy deposits in the detector, has been
implemented.


title: Playing with parameters: structural parameterization in graphs

abstract:
  When considering a graph problem from a parameterized point of view, the
parameter chosen is often the size of an optimal solution of this problem (the
"standard" parameter). A natural subject for investigation is what happens when
we parameterize such a problem by various other parameters, some of which may
be the values of optimal solutions to different problems. Such research is
known as parameterized ecology. In this paper, we investigate seven natural
vertex problems, along with their respective parameters: the size of a maximum
independent set, the size of a minimum vertex cover, the size of a maximum
clique, the chromatic number, the size of a minimum dominating set, the size of
a minimum independent dominating set and the size of a minimum feedback vertex
set. We study the parameterized complexity of each of these problems with
respect to the standard parameter of the others.


title: Assessing the number of atoms in a Rydberg-blockaded mesoscopic ensemble

abstract:
  The dipole blockade of multiple Rydberg excitations in mesoscopic atomic
ensembles allows the implementation of various quantum information tasks using
collective states of cold, trapped atoms. Precise coherent manipulations of the
collective ground and single Rydberg excitation states of an atomic ensemble
requires the knowledge of the number of atoms with small uncertainty. We
present an efficient method to acquire such information by interrogating the
atomic ensemble with resonant pulses while monitoring the resulting Rydberg
excitations. We show that after several such steps accompanied by feedback the
number of atoms in an ensemble can be assessed with high accuracy. This will
facilitate the realization of high fidelity quantum gates, long term storage of
quantum information and deterministic sources of single photons with
Rydberg-blockaded atomic ensembles.


title:
Effect of Correlations Between Model Parameters and Nuisance Parameters
  When Model Parameters are Fit to Data

abstract:
  The effect of correlations between model parameters and nuisance parameters
is discussed, in the context of fitting model parameters to data. Modifications
to the usual $\chi^2$ method are required. Fake data studies, as used at
present, will not be optimum. Problems will occur for applications of the
Maltoni-Schwetz \cite{ms} theorem. Neutrino oscillations are used as examples,
but the problems discussed here are general ones, which are often not
addressed.


title:
A quadratic refinement of the Grothendieck-Lefschetz-Verdier trace
  formula

abstract:
  We prove a trace formula in stable motivic homotopy theory over a general
base scheme, equating the trace of an endomorphism of a smooth proper scheme
with the "Euler characteristic integral" of a certain cohomotopy class over its
scheme of fixed points. When the base is a field and the fixed points are
\'etale, we compute this integral in terms of Morel's identification of the
ring of endomorphisms of the motivic sphere spectrum with the Grothendieck-Witt
ring. In particular, we show that the Euler characteristic of an \'etale
algebra corresponds to the class of its trace form in the Grothendieck-Witt
ring.


title:
An Integer Programming Formulation Applied to Optimum Allocation in
  Multivariate Stratified Sampling

abstract:
  The problem of optimal allocation of samples in surveys using a stratified
sampling plan was first discussed by Neyman in 1934. Since then, many
researchers have studied the problem of the sample allocation in multivariate
surveys and several methods have been proposed. Basically, these methods are
divided into two class: The first involves forming a weighted average of the
stratum variances and finding the optimal allocation for the average variance.
The second class is associated with methods that require that an acceptable
coefficient of variation for each of the variables on which the allocation is
to be done. Particularly, this paper proposes a new optimization approach to
the second problem. This approach is based on an integer programming
formulation. Several experiments showed that the proposed approach is efficient
way to solve this problem, considering a comparison of this approach with the
other approach from the literature.


title: Mutation Analysis for Security

abstract:
  Security has become, nowadays, a major concern for the organizations as the
majority of its applications are exposed to Internet, which increases the
threats of security considerably. Thus, the solution is to improve tools and
mechanisms to strengthen the protection of applications against attacks and
ensure the different security objectives. Among solutions we will talking
about, in this paper, there is Mutation Analysis which is a technique of test
that evaluates the quality of software tests and their ability to detect
errors, It also compares the criteria and test generation strategies. In this
study we will use the Mutation Analysis as a mean to qualify the penetration
tests, and then, apply this technique in the security mechanisms and exactly on
the mechanisms of access control. At the end we will propose a method for the
elimination of hidden mechanisms for access control that will allow the access
control policy to evolve.


title: Migration and Extension of Solar Active Longitudinal Zones

abstract:
  Solar active longitudes show a characteristic migration pattern in the
Carrington coordinate system when they can be identified at all. By following
this migration, the longitudinal activity distribution around the center of the
band can be determined. The halfwidth of the distribution is found to be
varying in Cycles 21 - 23, and in some time intervals it was as narrow as 20 -
30 degrees. It was more extended around maximum but it was also narrow when the
activity jumped to the opposite longitude. Flux emergence exhibited a
quasi-periodic variation within the active zone with a period of about 1.3
years. The path of the active longitude migration does not support the view
that it might be associated with the 11-year solar cycle. These results were
obtained for a limited time interval of a few solar cycles and, bearing in mind
uncertainties of the migration path definition, are only indicative. For the
major fraction of dataset no systematic active longitudes were found. Sporadic
migration of active longitudes was identified only for Cycles 21 - 22 in the
northern hemisphere and Cycle 23 in the southern hemisphere.


title:
Noise Weighting in the Design of {\Delta}{\Sigma} Modulators (with a
  Psychoacoustic Coder as an Example)

abstract:
  A design flow for {\Delta}{\Sigma} modulators is illustrated, allowing
quantization noise to be shaped according to an arbitrary weighting profile.
Being based on FIR NTFs, possibly with high order, the flow is best suited for
digital architectures. The work builds on a recent proposal where the modulator
is matched to the reconstruction filter, showing that this type of optimization
can benefit a wide range of applications where noise (including in-band noise)
is known to have a different impact at different frequencies. The design of a
multiband modulator, a modulator avoiding DC noise, and an audio modulator
capable of distributing quantization artifacts according to a psychoacoustic
model are discussed as examples. A software toolbox is provided as a general
design aid and to replicate the proposed results.


title: Interatomic potential for the compound-forming Li-Pb liquid alloy

abstract:
  Atomistic simulations of liquid alloys face the challenge of correctly
modeling basic thermodynamic properties. In this work we present an interatomic
potential for the Li-Pb system, as well as a study of physical properties of
Li-Pb alloys. Despite the complexity due to Li-Pb being a compound forming
system where charge transfer is expected, we show here how the empirical EAM
formalism is able to satisfactorily describe several physical properties in a
wide range of Li concentration. Application of our potential to Li-Pb eutectic
allows us to correctly predict many physical properties observed experimentally
and calculated with ab initio techniques, providing in this way a potential
suitable for future studies in the context of tritium breeder blanket designs
in Fusion technology.


title:
High harmonic generation from pre-ionized H$_2$ in ultrashort intense
  laser fields

abstract:
  Effects of the laser pulse wavelength and intensity on the HHG production
from the \textit{ionic} and \textit{homolytic} pre-ionization transient states
of the two-electron H$_{2}$ system exposed to ultrashort intense laser pulses
are studied by solving time-dependent Schr\"{o}dinger equation. It is found
that for the populated homolytic species in each half cycle of the laser pulse
having enough strength, a pair of strong and weak HHG radiations are produced
simultaneously. For the populated ionic species divided into two regions, in
each half cycle, one of the ionic regions has a strong radiation and the other
ionic region has a weak HHG radiation. The HHG spectra of the homolytic and
ionic species are almost similar, except that in some limited parts of the HHG
spectrum, one of them dominate the other.


title: Spectral multipliers for Laplacians with drift on Damek-Ricci spaces

abstract:
  We prove a multiplier theorem for certain Laplacians with drift on
Damek-Ricci spaces, which are a class of Lie groups of exponential growth. Our
theorem generalizes previous results obtained by W. Hebisch, G. Mauceri and S.
Meda on Lie groups of polynomial growth.


title: Complexity of measurement of a qubit pair

abstract:
  Analysis of the process of accumulation of the results of measurements shows
that the success of this process substantially depends on the possibility of
coordination of actions of two participants of the process - preparator who
prepares the series of the states being measured and registrator who chooses in
each event of measurement one of incompatible observables.
  A new value, the complexity of measurement of a state, is used, this
characterizes the number of the measurement events needed for solution of the
reconstruction problem. By means of this value it is shown that the dependence
of the upper limit of the needed number of measurements on the permissible
error is a square law one, so a twofold decrease of permissible error
corresponds to a fourfold increase of needed number of measurements.


title: Jacobi structures and Spencer operators

abstract:
  This paper explains the fundamental relation between Jacobi structures and
the classical Spencer operator coming from the theory of PDEs so as to provide
a direct and geometric approach to the integrability of Jacobi structures. It
uses recent results on the integrability of Spencer operators and
multliplicative forms on Lie groupoids with non-trivial coefficients. In
Theorem 1 we show that the Spencer operator associated to a contact groupoid
reveals that the base manifold carries a Jacobi structure. Theorem 2 deals with
the problem of integrating Jacobi structures to contact groupoids.


title:
Spherically symmetric Jordan-Brans-Dicke quantum gravity with de Broglie
  Bohm pilot wave perspective

abstract:
  We obtain two dimensional analogue of the Jordan-Brans-Dicke (JBD) gravity
action described in four dimensional spherically symmetric curved space time
metric. There will be two scalar fields, namely, the Brans Dicke (BD) $\phi$
and scale factor of 2-sphere part of the space time $\psi.$ We obtained
suitable duality transformations between $(\psi,\phi)$ and $(\rho,S)$ where
$\rho$ and $S$ is respectively amplitude and phase part of the corresponding de
Broglie pilot wave function $\Psi(\rho,S)=\sqrt{\rho}e^{iS}.$ Covariant
conservation of mass-energy current density of particles ensemble
$J_a=\rho\partial_aS,$ is established by applying a particular dynamical
conformal frame described by $(\rho,S).$


title: Random Forests on Distance Matrices for Imaging Genetics Studies

abstract:
  We propose a non-parametric regression methodology, Random Forests on
Distance Matrices (RFDM), for detecting genetic variants associated to
quantitative phenotypes representing the human brain's structure or function,
and obtained using neuroimaging techniques. RFDM, which is an extension of
decision forests, requires a distance matrix as response that encodes all
pair-wise phenotypic distances in the random sample. We discuss ways to learn
such distances directly from the data using manifold learning techniques, and
how to define such distances when the phenotypes are non-vectorial objects such
as brain connectivity networks. We also describe an extension of RFDM to detect
espistatic effects while keeping the computational complexity low. Extensive
simulation results and an application to an imaging genetics study of
Alzheimer's Disease are presented and discussed.


title: On John domains in Banach spaces

abstract:
  We study the stability of John domains in Banach spaces under removal of a
countable set of points. In particular, we prove that the class of John domains
is stable in the sense that removing a certain type of closed countable set
from the domain yields a new domain which also is a John domain. We apply this
result to prove the stability of the inner uniform domains. Finally, we
consider a wider class of domains, so called $\psi$-John domains and prove a
similar result for this class.


title:
Search for long-lived gravitational-wave transients coincident with long
  gamma-ray bursts

abstract:
  Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse
supernovae from massive stars. Gravitational waves (GW) offer a probe of the
physics behind long GRBs. We investigate models of long-lived (~10-1000s) GW
emission associated with the accretion disk of a collapsed star or with its
protoneutron star remnant. Using data from LIGO's fifth science run, and GRB
triggers from the swift experiment, we perform a search for unmodeled
long-lived GW transients. Finding no evidence of GW emission, we place 90%
confidence level upper limits on the GW fluence at Earth from long GRBs for
three waveforms inspired by a model of GWs from accretion disk instabilities.
These limits range from F<3.5 ergs cm^-2 to $F<1200 ergs cm^-2, depending on
the GRB and on the model, allowing us to probe optimistic scenarios of GW
production out to distances as far as ~33 Mpc. Advanced detectors are expected
to achieve strain sensitivities 10x better than initial LIGO, potentially
allowing us to probe the engines of the nearest long GRBs.


title: Role of viscous friction in the reverse rotation of a disk

abstract:
  The mechanical response of a circularly-driven disk in a dissipative medium
is considered. We focus on the role played by viscous friction in the spinning
motion of the disk, especially on the effect called reverse rotation, where the
intrinsic and orbital rotations are antiparallel. Contrary to what happens in
the frictionless case, where steady reverse rotations are possible, we find
that this dynamical behavior may exist only as a transient when dissipation is
considered. Whether or not reverse rotations in fact occur depend on the
initial conditions and on two parameters, one related to dragging, inertia, and
driving, the other associated with the geometric configuration of the system.
The critical value of this geometric parameter (separating the regions where
reverse rotation is possible from those where it is forbidden) as a function of
viscosity is well adjusted by a q-exponential function.


title: JRC-Names: A freely available, highly multilingual named entity resource

abstract:
  This paper describes a new, freely available, highly multilingual named
entity resource for person and organisation names that has been compiled over
seven years of large-scale multilingual news analysis combined with Wikipedia
mining, resulting in 205,000 per-son and organisation names plus about the same
number of spelling variants written in over 20 different scripts and in many
more languages. This resource, produced as part of the Europe Media Monitor
activity (EMM, http://emm.newsbrief.eu/overview.html), can be used for a number
of purposes. These include improving name search in databases or on the
internet, seeding machine learning systems to learn named entity recognition
rules, improve machine translation results, and more. We describe here how this
resource was created; we give statistics on its current size; we address the
issue of morphological inflection; and we give details regarding its
functionality. Updates to this resource will be made available daily.


title: Spin-Particles Entanglement in Robertson-Walker Spacetime

abstract:
  We study the entanglement between two modes of Dirac field in an expanding
spacetime characterized by the Robertson-Walker metric. This spacetime model
turns out to be asymptotically (in the remote past and far future regions)
Minkowskian. Then, on the one hand we show entanglement creation between
particles and anti-particles when passing from remote past to far future. On
the other hand we show that particles entanglement in the remote past degrades
into the far future. These effects are traced back to particles creation. In
our analysis we highlight the role of spin (polarization) of particles and
compare the results with those obtainable without accounting for it.


title:
Pricing and Hedging Derivative Securities with Unknown Local
  Volatilities

abstract:
  A common assumption in financial engineering is that the market price for any
derivative coincides with an objectively defined risk-neutral price - a
plausible assumption only if traders collectively possess objective knowledge
about the price dynamics of the underlying security over short time scales.
Here we assume that traders have an objective knowledge about the underlying
security's price trajectories only for large time scales. We show that
avoidance of arbitrage that is still feasible uniquely determines the prices of
options with large expiration times, and we derive limit theorems useful for
estimation of model parameters and present-value analysis of derivative
portfolios.


title:
Heisenberg XXX Model with General Boundaries: Eigenvectors from
  Algebraic Bethe Ansatz

abstract:
  We propose a generalization of the algebraic Bethe ansatz to obtain the
eigenvectors of the Heisenberg spin chain with general boundaries associated to
the eigenvalues and the Bethe equations found recently by Cao et al. The ansatz
takes the usual form of a product of operators acting on a particular vector
except that the number of operators is equal to the length of the chain. We
prove this result for the chains with small length. We obtain also an off-shell
equation (i.e. satisfied without the Bethe equations) formally similar to the
ones obtained in the periodic case or with diagonal boundaries.


title:
Improving computational efficiency of Monte-Carlo simulations with
  variance reduction

abstract:
  CCFE perform Monte-Carlo transport simulations on large and complex tokamak
models such as ITER. Such simulations are challenging since streaming and deep
penetration effects are equally important. In order to make such simulations
tractable, both variance reduction (VR) techniques and parallel computing are
used. It has been found that the application of VR techniques in such models
significantly reduces the efficiency of parallel computation due to 'long
histories'. VR in MCNP can be accomplished using energy-dependent weight
windows. The weight window represents an 'average behaviour' of particles, and
large deviations in the arriving weight of a particle give rise to extreme
amounts of splitting being performed and a long history. When running on
parallel clusters, a long history can have a detrimental effect on the parallel
efficiency - if one process is computing the long history, the other CPUs
complete their batch of histories and wait idle. Furthermore some long
histories have been found to be effectively intractable. To combat this effect,
CCFE has developed an adaptation of MCNP which dynamically adjusts the WW where
a large weight deviation is encountered. The method effectively 'de-optimises'
the WW, reducing the VR performance but this is offset by a significant
increase in parallel efficiency. Testing with a simple geometry has shown the
method does not bias the result. This 'long history method' has enabled CCFE to
significantly improve the performance of MCNP calculations for ITER on parallel
clusters, and will be beneficial for any geometry combining streaming and deep
penetration effects.


title:
Efficient coupling to an optical resonator by exploiting time-reversal
  symmetry

abstract:
  The interaction of a cavity with an external field is symmetric under time
reversal. Thus, coupling to a resonator is most efficient when the incident
light is the time reversed version of a free cavity decay, i.e. when it has a
rising exponential shape matching the cavity lifetime. For light entering the
cavity from only one side, the maximally achievable coupling efficiency is
limited by the choice of the cavity mirrors' reflectivities. Such an
empty-cavity experiment serves also as a model system for single-photon
single-atom absorption dynamics. We present experiments coupling exponentially
rising pulses to a cavity system which allows for high coupling efficiencies.
The influence of the time constant of the rising exponential is investigated as
well as the effect of a finite pulse duration. We demonstrate coupling 94% of
the incident TEM00 mode into the resonator.


title:
Lumped Parameter Modeling of a Quantum Optics Circuit and Decisive Test
  for Time-Symmetric Physics

abstract:
  This paper showed how a simple lumped parameter model of a circuit can yield
correct quantum mechanical predictions of its behavior, even when there is
quantum entanglement between components of that circuit. It addresses an
important example, the circuit of the original Bell's Theorem experiments for
ideal polarizers. Correct predictions emerge from two alternative simple but
time-symmetric models based on classical Markov Random Field across space time.
Exact agreement here does not violate Bell's Theorem itself, because the
interplay between initial and final outcomes in these calculations does not
fall within the CHSH definition of time forwards causality. Both models raise
interesting questions for future research. The final section discusses several
possible directions for following up on these results, both in lumped system
modeling and in more general approaches. The final section proposed a new
experiment with three-photon entanglement which could tell us which is true,
local realistic MRF models and time-symmetric physics, or conventional
predictions assuming the usual collapse of the wave function. The appendix
worked out what the conventional predictions would be for the proposed
experiment, and also gives a simple master equation version of the collapse
assumption which does not involve metaphysical observers. Section A.4 gives the
prediction for the new models.


title: Finite size of hadrons and Bose-Einstein correlations

abstract:
  It is observed that the finite size of hadrons produced in high energy
collisions implies that their positions are correlated, since the probability
of finding two hadrons on top of each other is highly reduced. It is then shown
that this effect can naturally explain the values of the correlation function
below one, observed at LEP and LHC for pairs of identical pions.


title: Graded cluster algebras

abstract:
  In the cluster algebra literature, the notion of a graded cluster algebra has
been implicit since the origin of the subject. In this work, we wish to bring
this aspect of cluster algebra theory to the foreground and promote its study.
  We transfer a definition of Gekhtman, Shapiro and Vainshtein to the algebraic
setting, yielding the notion of a multi-graded cluster algebra. We then study
gradings for finite type cluster algebras without coefficients, giving a full
classification.
  Translating the definition suitably again, we obtain a notion of
multi-grading for (generalised) cluster categories. This setting allows us to
prove additional properties of graded cluster algebras in a wider range of
cases. We also obtain interesting combinatorics---namely tropical frieze
patterns---on the Auslander--Reiten quivers of the categories.


title:
Self Assembly of and Plasmon Enhanced Ultrafast Magnetization in Ag Co
  Hybrid Nanoparticles

abstract:
  Ultrafast demagnetization in magnetic nanoparticles using pulsed laser has
attracted considerable attention because of its potential applications in
spintronics, such as data storage. In such applications, it is necessary to
control magnetization using low energy laser pulses, however, this poses the
problem of increasing the amount of energy from the excitation laser pulses to
the spin subsystem. We take advantage of the phenomenon known as localized
surface plasmon resonance (LSPR) to enhance the energy transfer from laser
pulses to the spin subsystem. To induce LSPR, hybrid nanoparticles consisting
of noble metal nanoparticles with LSPR absorption and magnetic metal
nanoparticles are prepared using a novel method. Specifically, AgCo hybrid
nanoparticles are prepared by a self assembly method using pulsed laser
deposition. We performed measurements of the static Faraday and time-resolved
Faraday effects using a pump probe technique on the AgCo hybrid nanoparticles
with various AgCo ratios. The data suggest that the LSPR absorption and
demagnetization amplitude increase with the increasing AgCo ratio. The results
indicate that the amount of energy transferred from the laser pulses to the
spin system of magnetic nanoparticles can increase via LSPR absorption.


title:
Generation of tunable wavelength coherent states and heralded single
  photons for quantum optics applications

abstract:
  Quantum optics experiments frequently involve interfering single photons and
coherent states. In the case of multi-photon experiments this requires that all
photons are frequency degenerate. We report a simple and practical approach to
generate coherent states that can be readily tuned to any wavelength required,
for example by non-degenerate photon pair creation. We demonstrate this by
performing a two-photon (Hong-Ou-Mandel) interference experiment between a
coherent state and a pure heralded single photon source. No spectral filtering
is required on either source, the coherent state constrained by the pump and
seed lasers and the heralded photon exploits non-local filtering. We expect
that such an approach can find a wide range of applications in photonic based
quantum information science.


title:
Rate of Convergence to Barenblatt Profiles for the Fast Diffusion
  Equation with a Critical Exponent

abstract:
  We study the asymptotic behaviour near extinction of positive solutions of
the Cauchy problem for the fast diffusion equation with a critical exponent.
After a suitable rescaling which yields a non--linear Fokker--Planck equation,
we find a continuum of algebraic rates of convergence to a self--similar
profile. These rates depend explicitly on the spatial decay rates of initial
data. This improves a previous result on slow convergence for the critical fast
diffusion equation ({\sc Bonforte et al}. in Arch Rat Mech Anal 196:631--680,
2010) and provides answers to some open problems.


title:
Discovery of very high energy gamma-ray emission from the BL Lac object
  PKS 0301-243 with H.E.S.S

abstract:
  The active galactic nucleus PKS 0301-243 (z=0.266) is a
high-synchrotron-peaked BL Lac object that is detected at high energies (HE,
100 MeV < E < 100 GeV) by Fermi/LAT. This paper reports on the discovery of PKS
0301-243 at very high energies (E>100 GeV) by the High Energy Stereoscopic
System (H.E.S.S.) from observations between September 2009 and December 2011
for a total live time of 34.9 hours. Gamma rays above 200 GeV are detected at a
significance of 9.4{\sigma}. A hint of variability at the 2.5{\sigma} level is
found. An integral flux I(E > 200 GeV) = (3.3 +/- 1.1_stat +/- 0.7_syst)e-12 ph
cm^-2s^-1 and a photon index {\Gamma} = 4.6 +/- 0.7_stat +/- 0.2_syst are
measured. Multi-wavelength light curves in HE, X-ray and optical bands show
strong variability, and a minimal variability timescale of eight days is
estimated from the optical light curve. A single-zone leptonic synchrotron
self-Compton scenario satisfactorily reproduces the multi-wavelength data. In
this model, the emitting region is out of equipartition and the jet is particle
dominated. Because of its high redshift compared to other sources observed at
TeV energies, the very high energy emission from PKS 0301-243 is attenuated by
the extragalactic background light (EBL) and the measured spectrum is used to
derive an upper limit on the opacity of the EBL.


title: Pulsations in the Late-type B Supergiant Star HD 202850

abstract:
  HD 202850 is a late B-type supergiant. It is known that photospheric lines of
such stars vary. Due to macroturbulence the lines are much wider than expected.
Macroturbulence has been linked to stellar pulsations. It has been reported
that there are several B supergiants that undergo pulsations. In our previous
work, we detected a pulsational period of 1.59 hours in this object from data
taken with the Ondrejov 2-m telescope. We continued to investigate this object
and we took several time series with the DAO 1.2-m telescope. Our new data
suggest that there may be some additional pulsational periods in this star. We
present our new results in this poster.


title:
Feature Learning with Gaussian Restricted Boltzmann Machine for Robust
  Speech Recognition

abstract:
  In this paper, we first present a new variant of Gaussian restricted
Boltzmann machine (GRBM) called multivariate Gaussian restricted Boltzmann
machine (MGRBM), with its definition and learning algorithm. Then we propose
using a learned GRBM or MGRBM to extract better features for robust speech
recognition. Our experiments on Aurora2 show that both GRBM-extracted and
MGRBM-extracted feature performs much better than Mel-frequency cepstral
coefficient (MFCC) with either HMM-GMM or hybrid HMM-deep neural network (DNN)
acoustic model, and MGRBM-extracted feature is slightly better.


title: A short note on gravity with tensor auxiliary fields

abstract:
  We consider gravity coupled to a second metric in the strong coupling limit,
where the second kinetic term is absent. This system belongs to the recently
discussed class of models of "gravity with auxiliary fields" by Pani et al. We
prove that, in vacuum, these theories are always equivalent to GR with a
cosmological constant, even in the case where the auxiliary field equations
contain identities leaving undetermined functions. In the situation where some
functions are undetermined, the actual value of the cosmological constant is
dictated by an initial condition, and not by the parameters in the action.


title:
Spot volatility estimation for high-frequency data: adaptive estimation
  in practice

abstract:
  We develop further the spot volatility estimator introduced in Hoffmann, Munk
and Schmidt-Hieber (2012) from a practical point of view and make it useful for
the analysis of high-frequency financial data. In a first part, we adjust the
estimator substantially in order to achieve good finite sample performance and
to overcome difficulties arising from violations of the additive microstructure
noise model (e.g. jumps, rounding errors). These modifications are justified by
simulations. The second part is devoted to investigate the behavior of
volatility in response to macroeconomic events. We give evidence that the spot
volatility of Euro-BUND futures is considerably higher during press conferences
of the European Central Bank. As an outlook, we present an estimator for the
spot covolatility of two different prices.