title: Amplitude death phenomena in delay--coupled Hamiltonian systems

abstract:
  Hamiltonian systems, when coupled {\it via} time--delayed interactions, do
not remain conservative. In the uncoupled system, the motion can typically be
periodic, quasiperiodic or chaotic. This changes drastically when delay
coupling is introduced since now attractors can be created in the phase space.
In particular for sufficiently strong coupling there can be amplitude death
(AD), namely the stabilization of point attractors and the cessation of
oscillatory motion. The approach to the state of AD or oscillation death is
also accompanied by a phase--flip in the transient dynamics. A discussion and
analysis of the phenomenology is made through an application to the specific
cases of harmonic as well as anharmoniccoupled oscillators, in particular the
H\'enon-Heiles system.


title:
Spatial distribution of optically induced atomic excitation in a dense
  and cold atomic ensemble

abstract:
  On the basis of our general theoretical results developed previously in JETP
112, 246 (2011), we calculate the spatial distribution of atoms excited in a
dense and cold atomic cloud by weak monochromatic light. We also study the
atomic distribution over different Zeeman sublevels of the excited state in
different parts of the cloud. The dependence of this distribution of atomic
excitation on the density of the atomic ensemble and the frequency of external
emission is investigated. We show that in the boundary regions of the cloud the
orientation and alignment of atomic angular momentum takes place. Analysis of
the spatial distribution of atomic excitation shows no noticeable signs of
light localization effects even in those parameter regimes where the
Ioffe-Regel criterium of strong localization is satisfied. However, comparative
calculations performed in the framework of the scalar approximation to the
dipole-dipole interaction reveals explicit manifestation of strong localization
under some conditions.


title: A brief compendium of time-dependent density-functional theory

abstract:
  Time-dependent density-functional theory (TDDFT) is a formally exact approach
to the time-dependent electronic many-body problem which is widely used for
calculating excitation energies. We present a survey of the fundamental
framework, practical aspects, and applications of TDDFT. This paper is mainly
intended for non-experts (students or researchers in other areas) who would
like to learn about the present state of TDDFT without going too deeply into
formal details.


title: Dendriform analogues of Lie and Jordan triple systems

abstract:
  We use computer algebra to determine all the multilinear polynomial
identities of degree $\le 7$ satisfied by the trilinear operations $(a \cdot b)
\cdot c$ and $a \cdot (b \cdot c)$ in the free dendriform dialgebra, where $a
\cdot b$ is the pre-Lie or the pre-Jordan product. For the pre-Lie triple
products, we obtain one identity in degree 3, and three independent identities
in degree 5, and we show that every identity in degree 7 follows from the
identities of lower degree. For the pre-Jordan triple products, there are no
identities in degree 3, five independent identities in degree 5, and ten
independent irreducible identities in degree 7. Our methods involve linear
algebra on large matrices over finite fields, and the representation theory of
the symmetric group.


title:
Fast construction of higher order digital nets for numerical integration
  in weighted Sobolev spaces

abstract:
  Higher order digital nets are special classes of point sets for quasi-Monte
Carlo rules which achieve the optimal convergence rate for numerical
integration of smooth functions. An explicit construction of higher order
digital nets was proposed by Dick, which is based on digitally interlacing in a
certain way the components of classical digital nets whose number of components
is a multiple $ds$ of the dimension $s$. In this paper we give a fast computer
search algorithm to find good classical digital nets suitable for interlaced
components by using polynomial lattice point sets.
  We consider certain weighted Sobolev spaces of smoothness of arbitrarily high
order, and derive an upper bound on the mean square worst-case error for
digitally shifted higher order digital nets. Employing this upper bound as a
quality criterion, we prove that the component-by-component construction can be
used efficiently to find good polynomial lattice point sets suitable for
interlaced components. Through this approach we are able to get some
tractability results under certain conditions on the weights. Fast construction
using the fast Fourier transform requires the construction cost of $O(dsN \log
N)$ operations using $O(N)$ memory, where $N$ is the number of points and $s$
is the dimension. This implies a significant reduction in the construction cost
as compared to higher order polynomial lattice point sets. Numerical
experiments confirm that the performance of our constructed point sets often
outperforms those of higher order digital nets with Sobol' sequences and
Niederreiter-Xing sequences used for interlaced components, indicating the
usefulness of our algorithm.


title:
A polynomial identity for the bilinear operation in Lie-Yamaguti
  algebras

abstract:
  We use computer algebra to demonstrate the existence of a multilinear
polynomial identity of degree 8 satisfied by the bilinear operation in every
Lie-Yamaguti algebra. This identity is a consequence of the defining identities
for Lie-Yamaguti algebras, but is not a consequence of anticommutativity. We
give an explicit form of this identity as an alternating sum over all
permutations of the variables in a polynomial with 8 terms. Our computations
also show that such identities do not exist in degrees less than 8.


title: Effects of the Detection Efficiency on Multiplicity Distributions

abstract:
  In this paper we investigate how a finite detection efficiency affects three
popular multiplicity distributions, namely the Poisson, the Binomial and the
Negative Binomial distributions. We found that a multiplicity-independent
detection efficiency does not change the characteristic of a distribution,
while a multiplicity-dependent detection efficiency does. We layout a procedure
to study the deviation of moments and their derivative quantities from the
baseline distribution due to a multiplicity-dependent detection efficiency.


title: Spectroscopy of the mysterious Be system FF Cam

abstract:
  FF Cam is a variable star near the North celestial pole with hydrogen lines
in emission. Its optical variability of ~0.3 mag was discovered by HIPPARCOS.
The spectral type assigned to the star in SIMBAD is B9, but its position
coincides with a ROSAT X-ray source. This suggests the presence of a
high-temperature region in the system that could originate at or near a
companion object. We undertook a spectroscopic monitoring of FF Cam since the
beginning of 2012 and found an extremely variable H-alpha line profile as well
as periodically variable radial velocities of numerous absorption lines. The
main conclusion from our study is that FF Cam is a binary system with an
orbital period of 7.785 days, a B-type primary and a K-type secondary
component. We discuss the spectral features, their variations, and the nature
of FF Cam.


title:
Schur function identities arising from the basic representation of
  $A^{(2)}_{2}$

abstract:
  A Lie theoretic interpretation is given for some formulas of Schur functions
and Schur $Q$-functions. Two realizations of the basic representation of the
Lie algebra $A^{(2)}_2$ are considered; one is on the fermionic Fock space and
the other is on the bosonic polynomial space. Via the boson-fermion
correspondence, simple relations of the vacuum expectation values of fermions
turn out to be algebraic relations of Schur functions.


title:
The existence and blow-up criterion of liquid crystals system in
  critical Besov space

abstract:
  We consider the existence of strong solution to liquid crystals system in
critical Besov space,then give a criterion which is similar to Serrin's
criterion on regularity of weak solution to Navier-Stokes equations.


title: A new framework for optimal classifier design

abstract:
  The use of alternative measures to evaluate classifier performance is gaining
attention, specially for imbalanced problems. However, the use of these
measures in the classifier design process is still unsolved. In this work we
propose a classifier designed specifically to optimize one of these alternative
measures, namely, the so-called F-measure. Nevertheless, the technique is
general, and it can be used to optimize other evaluation measures. An algorithm
to train the novel classifier is proposed, and the numerical scheme is tested
with several databases, showing the optimality and robustness of the presented
classifier.


title: How Many Queries Will Resolve Common Randomness?

abstract:
  A set of m terminals, observing correlated signals, communicate interactively
to generate common randomness for a given subset of them. Knowing only the
communication, how many direct queries of the value of the common randomness
will resolve it? A general upper bound, valid for arbitrary signal alphabets,
is developed for the number of such queries by using a query strategy that
applies to all common randomness and associated communication. When the
underlying signals are independent and identically distributed repetitions of m
correlated random variables, the number of queries can be exponential in signal
length. For this case, the mentioned upper bound is tight and leads to a
single-letter formula for the largest query exponent, which coincides with the
secret key capacity of a corresponding multiterminal source model. In fact, the
upper bound constitutes a strong converse for the optimum query exponent, and
implies also a new strong converse for secret key capacity. A key tool,
estimating the size of a large probability set in terms of Renyi entropy, is
interpreted separately, too, as a lossless block coding result for general
sources. As a particularization, it yields the classic result for a discrete
memoryless source.


title:
From F=ma to Flying Squirrels: Curricular Change in an Introductory
  Physics Course

abstract:
  We present outcomes from curricular changes made to an introductory
calculus-based physics course whose audience is primarily life science majors,
the majority of whom plan to pursue post-baccalaureate studies in medical and
scientific fields. During the 2011-12 academic year, we implemented a "Physics
of the life sciences" curriculum centered on a draft textbook that takes a
novel approach to teaching physics to life science majors. In addition,
substantial revisions were made to the homework and hands-on components of the
course to emphasize the relationship between physics and the life sciences and
to help the students to learn to apply physical intuition to life
science-oriented problems. Student learning and attitudinal outcomes were
assessed both quantitatively, using standard physics education research
instruments, and qualitatively, using student surveys and a series of
post-semester interviews. Students experienced high conceptual learning gains,
comparable to other active learning-based physics courses. Qualitatively, a
substantial fraction of interviewed students reported an increased interest in
physics relative to the beginning of the semester. Furthermore, more than half
of students self-reported that they could now relate physics topics to their
majors and future careers, with interviewed subjects demonstrating a high level
of ability to come up with examples of how physics affects living organisms and
how it helped them to better understand content presented in courses in their
major.


title:
Predicting Future Space Near-IR Grism Surveys using the WFC3 Infrared
  Spectroscopic Parallels Survey

abstract:
  We present near-infrared emission line counts and luminosity functions from
the HST WFC3 Infrared Spectroscopic Parallels (WISP) program for 29 fields
(0.037 deg^2) observed using both the G102 and G141 grisms. Altogether we
identify 1048 emission line galaxies with observed equivalent widths greater
than 40 Angstroms, 467 of which have multiple detected emission lines. The WISP
survey is sensitive to fainter flux levels (3-5x10^-17 ergs/s/cm^2) than the
future space near-infrared grism missions aimed at baryonic acoustic
oscillation cosmology (1-4x10^-16 ergs/s/cm^2), allowing us to probe the
fainter emission line galaxies that the shallower future surveys may miss.
Cumulative number counts of 0.7<z<1.5 galaxies reach 10,000 deg^-2 above an
H-alpha flux of 2x10^-16 ergs/s/cm^2. H-alpha-emitting galaxies with comparable
[OIII] flux are roughly 5 times less common than galaxies with just H-alpha
emission at those flux levels. Galaxies with low H-alpha/[OIII] ratios are very
rare at the brighter fluxes that future near-infrared grism surveys will probe;
our survey finds no galaxies with H-alpha/[OIII] < 0.95 that have H-alpha flux
greater than 3x10^-16 ergs/s/cm^2. Our H-alpha luminosity function contains a
comparable number density of faint line emitters to that found by the NICMOS
near-infrared grism surveys, but significantly fewer (factors of 3-4 less) high
luminosity emitters. We also find that our high redshift (z=0.9-1.5) counts are
in agreement with the high redshift (z=1.47) narrow band H-alpha survey of
HiZELS (Sobral et al. 2013), while our lower redshift luminosity function
(z=0.3-0.9) falls slightly below their z=0.84 result. The evolution in both the
H-alpha luminosity function from z=0.3--1.5 and the [OIII] luminosity function
from z=0.7-2.3 is almost entirely in the L* parameter, which steadily increases
with redshift over those ranges.


title: On the Entire Radial Solutions of the Chern-Simons SU(3) System

abstract:
  In this paper, we study the entire radial solutions of the self-dual
equations arising from the relativistic SU(3) Chern-Simons model proposed by
Kao-Lee and Dunne. Understanding the structure of entire radial solutions is
one of fundamental issues for the system of nonlinear equations. In this paper,
we prove any entire radial solutions must be one of topological,
non-topological and mixed type solutions, and completely classify the
asymptotic behaviors at infinity of these solutions. Even for radial solutions,
this classification has remained an open problem for many years. As an
application of this classification, we prove that the two components u and v
have intersection at most finite times.


title:
Complex scalar field in strictly stationary
  Einstein-Maxwell-axion-dilaton spacetime with negative cosmological constant

abstract:
  We proved that strictly stationary Einstein-Maxwell-axion-dilaton spacetime
with negative cosmological constant could not support a nontrivial
configuration of complex scalar fields. We considered the general case of the
arbitrary number of U(1) gauge fields in the theory under consideration.


title:
Quantum Suppression of Ratchet Rectification in a Brownian System Driven
  by a Biharmonic Force

abstract:
  We rigorously investigate the quantum dissipative dynamics of a ratchet
system described by a periodic potential model based on the Caldeira-Leggett
Hamiltonian with a biharmonic force. In this model, we use the reduced
hierarchy equations of motion in the Wigner space representation. These
equations represent a generalization of the Gaussian-Markovian quantum
Fokker-Planck equation introduced by Tanimura and Wolynes (1991), which was
formulated to study non-Markovian and non-perturbative thermal effects at
finite temperature. This formalism allows us to treat both the classical limit
and the tunneling regimes, and it is helpful for identifying purely quantum
mechanical effects through the time evolution of the Wigner distribution. We
carried out extensive calculations of the classical and quantum currents for
various temperatures, coupling strengths, and barrier heights. Our results
reveal that at low temperature, while the quantum current is larger than the
classical current in the case of a high barrier, the opposite is true in the
case of a low barrier. We find that this behavior results from the fact that
the tunneling enhances the current in the case of a high barrier, while it
suppresses the current in the case of a low barrier. This is because the effect
of the ratchet potential is weak in the case of a low barrier, due to the large
dispersion of the distribution introduced by tunneling. This causes the
spatio-temporal asymmetry, which is necessary for ratchet current, to be weak,
and as a result, the net current is suppressed.


title:
Quasi Long Range Order of Defects in Frustrated Antiferromagnetic Ising
  Models on Spatially Anisotropic Triangular Lattices

abstract:
  It is known that there is no phase transition down to zero temperature in the
antiferromagnetic Ising model on spatially anisotropic triangular lattices, in
which the exchange coupling of one direction is stronger than those of other
two directions. In the model, the low-temperature physics is governed by
domain-wall excitations (defects) residing on bonds of the strong-coupling
direction. In this letter, we show that an additional small attractive
interaction between defects (a ferromagnetic next-nearest-neighbor interaction
in the weak-coupling direction) leads to a Berezinskii-Kosterlitz-Thouless
(BKT) transition at a finite temperature, by performing the Monte Carlo
simulation. The BKT phase can be viewed as the phase with a quasi long-range
order of defects. We determine the phase diagram in a wide parameter regime and
argue the phase structure from statistical-mechanics and field-theory
viewpoints.


title:
Derivation in strong topology and global well-posedness of solutions to
  the Gross-Pitaevskii hierarchy

abstract:
  We derive the cubic defocusing GP hierarchy in ${\mathbb R}^3$ from a bosonic
$N$-particle Schr\"odinger equation as $N\rightarrow\infty$, in the strong
topology corresponding to the space ${\mathcal H}_\xi^1$ introduced in
\cite{chpa}. In particular, we thereby eliminate the requirement of regularity
${\mathcal H}_\xi^{1+}$ for the initial data used in \cite{CPBBGKY}. Moreover,
the marginal density matrices obtained in this strong limit are allowed to be
of infinite rank. This contrasts previous results where weak-* limits were
derived, and subsequently enhanced to strong limits based on the condition that
the limiting density matrices have finite rank. Furthermore, we prove that
positive semidefiniteness of marginal density matrices is preserved over time,
which we combine with results in \cite{CPHE}, to obtain the global
well-posedness of solutions.


title: Turbulent fronts of quantum detonation in molecular magnets

abstract:
  Dipolar-controlled quantum deflagration going over into quantum detonation in
the elongated Mn_12 Ac molecular magnet in a strong transverse field has been
considered within the full 3d model. It is shown that within the dipolar window
around tunneling resonances the deflagration front is non-flat. With increasing
bias, dipolar instability makes the front turbulent, while its speed reaches
sonic values, that is a signature of detonation.


title: Computing the autotopy group of a Latin square by cycle structure

abstract:
  An algorithm that uses the cycle structure of the rows, or the columns, of a
Latin square to compute its autotopy group is introduced. As a result, a bound
for the size of the autotopy group is obtained. This bound is used to show that
the computation time for the autotopy group of Latin squares that have two rows
or two columns that map from one to the other by a permutation which decomposes
into a bounded number of disjoint cycles, is polynomial in the order $n$.


title: Interdiction Problems on Planar Graphs

abstract:
  Interdiction problems are leader-follower games in which the leader is
allowed to delete a certain number of edges from the graph in order to
maximally impede the follower, who is trying to solve an optimization problem
on the impeded graph. We introduce approximation algorithms and strong
NP-completeness results for interdiction problems on planar graphs. We give a
multiplicative $(1 + \epsilon)$-approximation for the maximum matching
interdiction problem on weighted planar graphs. The algorithm runs in
pseudo-polynomial time for each fixed $\epsilon > 0$. We also show that
weighted maximum matching interdiction, budget-constrained flow improvement,
directed shortest path interdiction, and minimum perfect matching interdiction
are strongly NP-complete on planar graphs. To our knowledge, our
budget-constrained flow improvement result is the first planar NP-completeness
proof that uses a one-vertex crossing gadget.


title:
Dynamics of prolate spheroidal mass distributions with varying
  eccentricity

abstract:
  In this paper we calculate the potential for a prolate spheroidal
distribution as in a dark matter halo with a radially varying eccentricity.
This is obtained by summing up the shell-by-shell contributions of isodensity
surfaces, which are taken to be concentric and with a common polar axis and
with an axis ratio that varies with radius. Interestingly, the constancy of
potential inside a shell is shown to be a good approximation even when the
isodensity contours are dissimilar spheroids, as long as the radial variation
in eccentricity is small as seen in realistic systems. We consider three cases
where the isodensity contours are more prolate at large radii, or are less
prolate, or have a constant eccentricity. Other relevant physical quantities
like the rotation velocity, the net orbital and vertical frequency due to the
halo and an exponential disc of finite thickness embedded in it are obtained.
We apply this to the kinematical origin of Galactic warp, and show that a
prolate shaped halo is not conducive to making long-lived warps - contrary to
what has been proposed in the literature. The results for a prolate mass
distribution with a variable axis ratio obtained are general, and can be
applied to other astrophysical systems such as prolate bars, for a more
realistic treatment.


title:
A Collapse Theorem for Holographic Algorithms with Matchgates on Domain
  Size at Most 4

abstract:
  Holographic algorithms with matchgates are a novel approach to design
polynomial time computation. It uses Kasteleyn's algorithm for perfect
matchings, and more importantly a holographic reduction . The two fundamental
parameters of a holographic reduction are the domain size $k$ of the underlying
problem, and the basis size $\ell$. A holographic reduction transforms the
computation to matchgates by a linear transformation that maps to (a tensor
product space of) a linear space of dimension $2^{\ell}$. We prove a sharp
basis collapse theorem, that shows that for domain size 3 and 4, all
non-trivial holographic reductions have basis size $\ell$ collapse to 1 and 2
respectively. The main proof techniques are Matchgates Identities, and a Group
Property of matchgates signatures.


title: On semi-continuity problems for minimal log discrepancies

abstract:
  We show the semi-continuity property of minimal log discrepancies for
varieties which have a crepant resolution in the category of Deligne-Mumford
stacks. Using this property, we also prove the ideal-adic semi-continuity
problem for toric pairs.


title:
The compositional inverse of a class of linearized permutation
  polynomials over $\mathbb{F}_{2^n}$, $n$ odd

abstract:
  In this paper, the compositional inverses of a class of linearized
permutation polynomials of the form $P(x)=x+x^2+\tr(\frac{x}{a})$ over the
finite field $\mathbb{F}_{2^n}$ for an odd positive integer $n$ are explicitly
determined.


title:
An Analysis of Isgur-Wise Function of Heavy-Light Mesons within a Higher
  Dimensional Potential Model Approach

abstract:
  Nambu-Goto action for bosonic string predicts the quark-antiquark potential
to be $V(r) = -\frac{\gamma}{r}+ \sigma r + \mu_0$. The coefficient
$\gamma=\frac{\pi(d-2)}{24}$ is the L\"{u}scher coefficient of the L\"{u}scher
term $\frac{\gamma}{r}$, which depends upon the space-time dimension `d'. Very
recently, we have developed meson wave functions in higher dimension with this
potential from higher dimensional Schrodinger equation by applying quantum
mechanical perturbation technique with both $L\ddot{u}scher$ term as parent and
as perturbation. In this letter, we analyze Isgur-Wise function for heavy-light
mesons using these wave functions in higher dimension and make a comparative
study on the status of the perturbation technique in both the cases.


title: The dynamical evolution of multi-planet systems in open clusters

abstract:
  The majority of stars form in star clusters and many are thought to have
planetary companions. We demonstrate that multi-planet systems are prone to
instabilities as a result of frequent stellar encounters in these star clusters
much more than single-planet systems. The cumulative effect of close and
distant encounters on these planetary systems are investigated using Monte
Carlo scattering experiments. We consider two types of planetary configurations
orbiting Sun-like stars: (i) five Jupiter-mass planets in the semi-major axis
range 1-42 AU orbiting a Solar mass star, with orbits that are initially
co-planar, circular, and separated by 10 mutual Hill radii, and (ii) the four
gas giants of our Solar system. Planets with short orbital periods are not
directly affected by encountering stars. However, secular evolution of
perturbed systems may result in the ejection of the innermost planets or in
physical collisions of the innermost planets with the host star, up to many
thousands of years after a stellar encounter. The simulations of the Solar
system-like systems indicate that Saturn, Uranus and Neptune are affected by
both direct interactions with encountering stars, as well as planet-planet
scattering. Jupiter, on the other hand, is almost only affected by direct
encounters with neighbouring stars, as its mass is too large to be
substantially perturbed by the other three planets. Our results indicate that
stellar encounters can account for the apparent scarcity of exoplanets in star
clusters, not only for those on wide-orbit that are directly affected by
stellar encounters, but also planets close to the star which can disappear long
after a stellar encounter has perturbed the planetary system.


title:
Final state emission radiative corrections to the process $e^+e^- \to
  \pi^+\pi^-(\gamma)$. Contribution to muon anomalous magnetic moment

abstract:
  Analytic calculation are presented of the contribution to the anomalous
magnetic moment of a muon from the channels of annihilation of an
electron-positron pair to a pair of charged pi-mesons with radiative correction
connected with the final state, as well as corrections to the lowest order
kernel. The result with point-like pi-meson assumptions is
$a_{point}=a_{point}^{(1)}+\Delta a_{point}$, $a_{point}^{(1)}=7.0866 \cdot
10^{-9}; \Delta a_{point}= -2.4 \cdot 10^{-10} .$ Taking into account the pion
form factor in the frames of the Nambu-Jona-Lasinio (NJL) approach leads to
$a_{NJL}=a_{NJL}^{(1)}+\Delta a_{NJL}$, $a_{NJL}^{(1)}= 5.48\cdot 10^{-8};
\Delta a_{NJL}=-3.43\cdot 10^{-9}$.


title:
Centralized and Cooperative Transmission of Secure Multiple Unicasts
  using Network Coding

abstract:
  We introduce a method for securely delivering a set of messages to a group of
clients over a broadcast erasure channel where each client is interested in a
distinct message. Each client is able to obtain its own message but not the
others'. In the proposed method the messages are combined together using a
special variant of random linear network coding. Each client is provided with a
private set of decoding coefficients to decode its own message. Our method
provides security for the transmission sessions against computational
brute-force attacks and also weakly security in information theoretic sense. As
the broadcast channel is assumed to be erroneous, the missing coded packets
should be recovered in some way. We consider two different scenarios. In the
first scenario the missing packets are retransmitted by the base station
(centralized). In the second scenario the clients cooperate with each other by
exchanging packets (decentralized). In both scenarios, network coding
techniques are exploited to increase the total throughput. For the case of
centralized retransmissions we provide an analytical approximation for the
throughput performance of instantly decodable network coded (IDNC)
retransmissions as well as numerical experiments. For the decentralized
scenario, we propose a new IDNC based retransmission method where its
performance is evaluated via simulations and analytical approximation.
Application of this method is not limited to our special problem and can be
generalized to a new class of problems introduced in this paper as the
cooperative index coding problem.


title:
Regge-Wheeler equation, linear stability, and greybody factors for dirty
  black holes

abstract:
  So-called "dirty" black holes are those surrounded by non-zero stress-energy,
rather than vacuum. The presence of the non-zero stress-energy modifies key
features of the black hole, such as the surface gravity, Regge-Wheeler
equation, linear stability, and greybody factors in a rather nontrivial way.
Working within the inverse-Cowling approximation, (effectively the test-field
limit), we shall present general forms for the Regge-Wheeler equation for
linearized spin 0, spin 1, and axial spin 2 perturbations on an arbitrary
static spherically symmetric background spacetime. Using very general features
of the background spacetime, (in particular the classical energy conditions for
the stress-energy surrounding the black hole), we extract several interesting
and robust bounds on the behaviour of such systems, including rigorous bounds
on the greybody factors for dirty black holes.


title: CPT violation and triple-product correlations in B decays

abstract:
  The T-odd triple product (TP) asymmetries in B decays to a pair of vector
mesons are treated as a good probe of CP violation because of the CPT symmetry.
If CPT is no longer a good symmetry, such correlations between T-odd and CP-odd
observables do not exist, and one might get unexpected nonzero TP asymmetries
as a signal for CPT violation. We give a general formalism of TP asymmetries in
the presence of CPT violation, either in decay or in neutral meson mixing. We
also discuss how the observables depending on the transversity amplitudes are
modified, and compare our expressions with the LHCb results, showing that the
study of TP asymmetries might turn out to be one of the best probes for CPT
violation.


title: A note on the scaling limits of contour functions of Galton-Watson trees

abstract:
  Recently, Abraham and Delmas constructed the distributions of super-critical
L\'evy trees truncated at a fixed height by connecting super-critical L\'evy
trees to (sub)critical L\'evy trees via a martingale transformation. A similar
relationship also holds for discrete Galton-Watson trees. In this work, using
the existing works on the convergence of contour functions of (sub)critical
trees, we prove that the contour functions of truncated super-critical
Galton-Watson trees converge weakly to the distributions constructed by Abraham
and Delmas.


title: Neutrinos from Stored Muons nuSTORM: Expression of Interest

abstract:
  The nuSTORM facility has been designed to deliver beams of electron and muon
neutrinos from the decay of a stored muon beam with a central momentum of 3.8
GeV/c and a momentum spread of 10%. The facility is unique in that it will:
serve the future long- and short-baseline neutrino-oscillation programmes by
providing definitive measurements of electron-neutrino- and
muon-neutrino-nucleus cross sections with percent-level precision; allow
searches for sterile neutrinos of exquisite sensitivity to be carried out; and
constitute the essential first step in the incremental development of muon
accelerators as a powerful new technique for particle physics.
  Of the world's proton-accelerator laboratories, only CERN and FNAL have the
infrastructure required to mount nuSTORM. Since no siting decision has yet been
taken, the purpose of this Expression of Interest (EoI) is to request the
resources required to: investigate in detail how nuSTORM could be implemented
at CERN; and develop options for decisive European contributions to the nuSTORM
facility and experimental programme wherever the facility is sited.
  The EoI defines a two-year programme culminating in the delivery of a
Technical Design Report.


title: Comb-like models for transport along spiny dendrites

abstract:
  We suggest a modification of a comb model to describe anomalous transport in
spiny dendrites. Geometry of the comb structure consisting of a one-dimensional
backbone and lateral branches makes it possible to describe anomalous
diffusion, where dynamics inside fingers corresponds to spines, while the
backbone describes diffusion along dendrites. The presented analysis
establishes that the fractional dynamics in spiny dendrites is controlled by
fractal geometry of the comb structure and fractional kinetics inside the
spines. Our results show that the transport along spiny dendrites is
subdiffusive and depends on the density of spines in agreement with recent
experiments.


title: An arithmetic interpretation of generalized Li's criterion

abstract:
  Recently, we have established the generalized Li's criterion equivalent to
the Riemann hypothesis, viz. demonstrated that the sums over all non-trivial
Riemann function zeroes k_n,a=Sum_rho(1-(1-((rho-a)/(rho+a-1))^n) for any real
a not equal to 1/2 are non-negative if and only if the Riemann hypothesis holds
true; arXiv:1304.7895 (2013); Ukrainian Math. J., V.66, N3, 371-383 (2014). An
arithmetic interpretation of this generalized Li's criterion is given here.


title: Somoclu: An Efficient Parallel Library for Self-Organizing Maps

abstract:
  Somoclu is a massively parallel tool for training self-organizing maps on
large data sets written in C++. It builds on OpenMP for multicore execution,
and on MPI for distributing the workload across the nodes in a cluster. It is
also able to boost training by using CUDA if graphics processing units are
available. A sparse kernel is included, which is useful for high-dimensional
but sparse data, such as the vector spaces common in text mining workflows.
Python, R and MATLAB interfaces facilitate interactive use. Apart from fast
execution, memory use is highly optimized, enabling training large emergent
maps even on a single computer.


title:
Observation of the universal jump across the
  Berezinskii-Kosterlitz-Thouless transition in two-dimensional Bose gases

abstract:
  The physics in two-dimensional (2D) systems is very different from what we
observe in three-dimensional (3D) systems. Thermal fluctuations in 2D systems
are enhanced, and they prevent the conventional Bose-Einstein condensation
(BEC) at non-zero temperatures by destroying the long-range order. However, a
phase transition to a superfluid phase is still expected to occur in a 2D
system along with an emergence of a quasi-long-range order, explained by the
Berezinskii-Kosterlitz-Thouless (BKT) mechanism. Within the BKT mechanism, a
universal jump of the superfluid density in a 2D Bosonic system was
theoretically predicted by Nelson and Kosterlitz, and was first observed in 2D
\textsuperscript{4}He films by Bishop and Reppy. Recent experiments in trapped
ultracold 2D Bose gas systems have shown signatures of the BKT transition, and
its superfluidity. However, the universal jump in the superfluid density was
not observed in these systems. Here we report the first observation of the
universal jump in the superfluid density using an optically trapped ultracold
2D Bose gas. The measured superfluid phase space density at the BKT transition
agrees well with the predicted value within our measurement uncertainty.
Additionally, we measure the phase fluctuations in our density profiles to show
that the BKT transition occurs first, followed by the BEC transition.


title:
Excitonic effects on coherent phonon dynamics in single wall carbon
  nanotubes

abstract:
  We discuss how excitons can affect the generation of coherent radial
breathing modes in ultrafast spectroscopy of single wall carbon nanotubes.
Photoexcited excitons can be localized spatially and give rise to a spatially
distributed driving force in real space which involves many phonon wavevectors
of the exciton-phonon interaction. The equation of motion for the coherent
phonons is modeled phenomenologically by the Klein-Gordon equation, which we
solve for the oscillation amplitudes as a function of space and time. By
averaging the calculated amplitudes per nanotube length, we obtain
time-dependent coherent phonon amplitudes that resemble the homogeneous
oscillations that are observed in some pump-probe experiments. We interpret
this result to mean that the experiments are only able to see a spatial average
of coherent phonon oscillations over the wavelength of light in carbon
nanotubes and the microscopic details are averaged out. Our interpretation is
justified by calculating the time-dependent absorption spectra resulting from
the macroscopic atomic displacements induced by the coherent phonon
oscillations. The calculated coherent phonon spectra including excitonic
effects show the experimentally observed symmetric peaks at the nanotube
transition energies in contrast to the asymmetric peaks that would be obtained
if excitonic effects were not included.


title: Relativistic Langevin Dynamics in Expanding Media

abstract:
  We study the consequences of different realizations of diffusion processes in
relativistic Langevin simulations. We elaborate on the Ito-Stratonovich dilemma
by showing how microscopically calculated transport coefficients as obtained
from a Boltzmann/Fokker-Planck equation can be implemented to lead to an
unambiguous realization of the Langevin process. Pertinent examples within the
pre-point (Ito) and post-point (H\"anggi-Klimontovich) Langevin prescriptions
are worked out explicitly. Deviations from this implementation are shown to
generate variants of the Boltzmann distribution as the stationary (equilibrium)
solutions. Finally, we explicitly verify how the Lorentz invariance of the
Langevin process is maintained in the presence of an expanding medium,
including the case of an "elliptic flow" transmitted to a Brownian test
particle. This is particularly relevant for using heavy-flavor diffusion as a
quantitative tool to diagnose transport properties of QCD matter as created in
ultrarelativistic heavy-ion collisions.


title: Speech Enhancement Modeling Towards Robust Speech Recognition System

abstract:
  Form about four decades human beings have been dreaming of an intelligent
machine which can master the natural speech. In its simplest form, this machine
should consist of two subsystems, namely automatic speech recognition (ASR) and
speech understanding (SU). The goal of ASR is to transcribe natural speech
while SU is to understand the meaning of the transcription. Recognizing and
understanding a spoken sentence is obviously a knowledge-intensive process,
which must take into account all variable information about the speech
communication process, from acoustics to semantics and pragmatics. While
developing an Automatic Speech Recognition System, it is observed that some
adverse conditions degrade the performance of the Speech Recognition System. In
this contribution, speech enhancement system is introduced for enhancing speech
signals corrupted by additive noise and improving the performance of Automatic
Speech Recognizers in noisy conditions. Automatic speech recognition
experiments show that replacing noisy speech signals by the corresponding
enhanced speech signals leads to an improvement in the recognition accuracies.
The amount of improvement varies with the type of the corrupting noise.


title:
Achievable Rate Derivations and Further Simulation Results for
  "Physical-Layer Multicasting by Stochastic Transmit Beamforming and Alamouti
  Space-Time Coding"

abstract:
  This is a companion technical report of the main manuscript "Physical-Layer
Multicasting by Stochastic Transmit Beamforming and Alamouti Space-Time
Coding". The report serves to give detailed derivations of the achievable rate
functions encountered in the main manuscript, which are too long to be included
in the latter. In addition, more simulation results are presented to verify the
viability of the multicast schemes developed in the main manuscript.


title: Speech based Password Protected Cyber Applications

abstract:
  Whenever we think of cyber applications, we visualize the model that gives
the idea that we are sitting in front of computer at home or workplace
connected to internet and performing all the work that generally we have to go
and do on a specific place for example e-shopping, e-banking, e-education etc.
In case of e-shopping, we view all the products on the computer screen with all
details by a single mouse click, select the product and do all further money
transaction through net. When we think of security, is it 100% secure? No, not
at all because though it is password protected, the password is a text base
secrete code that can be open. Therefore this paper is concentrated on
preparation of speech based password protected applications.


title: Speech User Interface for Information Retrieval

abstract:
  Along with the rapid development of information technology, the amount of
information generated at a given time far exceeds human's ability to organize,
search, and manipulate without the help of automatic systems. Now a days so
many tools and techniques are available for storage and retrieval of
information. User uses interface to interact with these techniques, mostly text
user interface (TUI) or graphical user interface (GUI). Here, I am trying to
introduce a new interface i.e. speech for information retrieval. The goal of
this project is to develop a speech interface that can search and read the
required information from the database effectively, efficiently and more
friendly. This tool will be highly useful to blind people, they will able to
demand the information to the computer by giving voice command/s (keyword)
through microphone and listen the required information using speaker or
headphones.


title: Leavitt path algebras are graded von Neumann regular rings

abstract:
  In sharp contrast to the Abrams-Rangaswamy Theorem that the only von Neumann
regular Leavitt path algebras are exactly those associated to acyclic graphs,
here we prove that the Leavitt path algebra of any arbitrary graph is a graded
von Neumann regular ring. Several properties of Leavitt path algebras, such as
triviality of the Jacobson radical, flatness of graded modules and finitely
generated graded right (left) ideals being generated by an idempotent element,
follow as a consequence of general theory of grade von Neumann regular rings.


title: Subextensions for a permutation PSL(2,q)-module

abstract:
  Using cohomological methods, we prove the existence of a subgroup isomorphic
to SL(2,q), q = -1 (mod 4), in the permutation module for PSL(2,q) in
characteristic 2 that arises from the action on the projective line. A similar
problem for q = 1 (mod 4) is reduced to the determination of certain first
cohomology groups.


title: Pressure fluctuations in isotropic solids and fluids

abstract:
  Comparing isotropic solids and fluids at either imposed volume or pressure we
investigate various correlations of the instantaneous pressure and its ideal
and excess contributions. Focusing on the compression modulus K it is
emphasized that the stress fluctuation representation of the elastic moduli may
be obtained directly (without a microscopic displacement field) by comparing
the stress fluctuations in conjugated ensembles. This is made manifest by
computing the Rowlinson stress fluctuation expression K_row of the compression
modulus for NPT-ensembles. It is shown theoretically and numerically that
K_row|P = P_id (2 - P_id/K) with P_id being the ideal pressure contribution.


title: Half exact functors associated with cotorsion pairs on exact categories

abstract:
  In the previous article "Hearts of twin cotorsion pairs on exact categories",
we introduced the notion of the heart for any cotorsion pair on an exact
category with enough projectives and injectives, and showed that it is an
abelian category. In this paper, we construct a half exact functor from the
exact category to the heart. This is analog of the construction of Abe and
Nakaoka for triangulated categories. We will also use this half exact functor
to find out a sufficient condition when two different hearts are equivalent.


title: Gateway Switching in Q/V Band Satellite Feeder Links

abstract:
  A main challenge towards realizing the next generation Terabit/s broadband
satellite communications (SatCom) is the limited spectrum available in the Ka
band. An attractive solution is to move the feeder link to the higher Q/V band,
where more spectrum is available. When utilizing the Q/V band, due to heavy
rain attenuation, gateway diversity is considered a necessity to ensure the
required feeder link availability. Although receive site diversity has been
studied in the past for SatCom, there is much less maturity in terms of
transmit diversity techniques. In this paper, a modified switch and stay
combining scheme is proposed for a Q/V band feeder link, but its performance is
also evaluated over an end-to-end satellite link. The proposed scheme is
pragmatic and has close to optimal performance with notably lower complexity.


title:
On the origin and universality of dislocation creation and void
  nucleation in FCC ductile metals

abstract:
  We clarify via molecular dynamic simulations and theoretical analysis the
origin of dislocation creation and void nucleation during uniaxial tensile
process in face-centered-cubic (FCC) ductile metals. We show that the
dislocations are created through three distinguished stages: (i) Flattened
octahedral structures (FOSs) are randomly activated by thermal fluctuations;
(ii) The double-layer defect clusters are formed by self-organized stacking of
FOSs on the close-packed plane; (iii) The stacking faults surrounded by the
Shockley partial dislocations are created from the double-layer defect cluster
due to the relative slip of internal atoms. Whereas, the void nucleation is
shown to follow a two-stages description: (i) The vacancy strings are first
formed by intersection of different stacking faults; (ii) Then the vacancy
strings transform into the voids by emitting dislocations. We demonstrate that
our findings on the origin of dislocation creation and void nucleation is
universal for a variety of FCC ductile metals with low stacking fault energy.


title:
Response to No gene-specific optimization of mutation rate in
  Escherichia coli

abstract:
  In a letter published in Molecular Biology Evolution [10], Chen and Zhang
argue that the variation of the mutation rate along the Escherichia coli genome
that we recently reported [3] cannot be evolutionarily optimised. To support
this claim they first attempt to calculate the selective advantage of a local
reduction in the mutation rate and conclude that it is not strong enough to be
favoured by selection. Second, they analyse the distribution of 166 mutations
from a wild-type E. coli K12 MG1655 strain and 1,346 mutations from a
repair-deficient strain, and claim to find a positive association between
transcription and mutation rate rather than the negative association that we
reported. Here we respond to this communication. Briefly, we explain how the
long-standing theory of mutation-modifier alleles supports the evolution of
local mutation rates within a genome by mechanisms acting on sufficiently large
regions of a genome, which is consistent with our original observations [3,4].
We then explain why caution must be exercised when comparing mutations from
repair deficient strains to data from wild-type strains, as different
mutational processes dominate these conditions. Finally, a reanalysis of the
data used by Zhang and Chen with an alternative expression dataset reveals that
their conclussions are unreliable.


title: Centroid bodies and the convexity of area functionals

abstract:
  We introduce a new volume definition on normed vector spaces. We show that
the induced $k$-area functionals are convex for all $k$. In the particular case
$k=2$, our theorem implies that Busemann's 2-volume density is convex, which
was recently shown by Burago-Ivanov. We also show how the new volume definition
is related to the centroid body and prove some affine isoperimetric
inequalities.


title: Simultaneous projectional skeletons

abstract:
  We prove the existence of a simultaneous projectional skeleton for certain
subspaces of $\mathcal{C}(K)$ spaces. This generalizes a result on simultaneous
projectional resolutions of identity proved by M. Valdivia. We collect some
consequences of this result. In particular we give a new characterization of
Asplund spaces using the notion of projectional skeleton.


title: Supervision Localization of Timed Discrete-Event Systems

abstract:
  We study supervisor localization for real-time discrete-event systems (DES)
in the Brandin-Wonham framework of timed supervisory control. We view a
real-time DES as comprised of asynchronous agents which are coupled through
imposed logical and temporal specifications; the essence of supervisor
localization is the decomposition of monolithic (global) control action into
local control strategies for these individual agents. This study extends our
previous work on supervisor localization for untimed DES, in that monolithic
timed control action typically includes not only disabling action as in the
untimed case, but also ``clock preempting'' action which enforces prescribed
temporal behavior. The latter action is executed by a class of special events,
called ``forcible'' events; accordingly, we localize monolithic preemptive
action with respect to these events. We demonstrate the new features of timed
supervisor localization with a manufacturing cell case study, and discuss a
distributed control implementation.


title:
Enhanced and continuous electrostatic carrier doping on the SrTiO$_{3}$
  surface

abstract:
  Paraelectrical tuning of a charge carrier density as high as
10$^{13}$\,cm$^{-2}$ in the presence of a high electronic carrier mobility on
the delicate surfaces of correlated oxides, is a key to the technological
breakthrough of a field effect transistor (FET) utilising the metal-nonmetal
transition. Here we introduce the Parylene-C/Ta$_{2}$O$_{5}$ hybrid gate
insulator and fabricate FET devices on single-crystalline SrTiO$_{3}$, which
has been regarded as a bedrock material for oxide electronics. The gate
insulator accumulates up to $\sim10^{13}$cm$^{-2}$ carriers, while the
field-effect mobility is kept at 10\,cm$^2$/Vs even at room temperature.
Further to the exceptional performance of our devices, the enhanced
compatibility of high carrier density and high mobility revealed the mechanism
for the long standing puzzle of the distribution of electrostatically doped
carriers on the surface of SrTiO$_{3}$. Namely, the formation and continuous
evolution of field domains and current filaments.


title: On the Fujita-Zariski decomposition on threefolds

abstract:
  We prove that, on a smooth threefold, pseudoeffective divisors with closed
and one-dimensional diminished base locus have birationally a Fujita-Zariski
decomposition.


title:
On the Distribution of Random variables corresponding to Musielak-Orlicz
  norms

abstract:
  Given a normalized Orlicz function $M$ we provide an easy formula for a
distribution such that, if $X$ is a random variable distributed accordingly and
$X_1,...,X_n$ are independent copies of $X$, then the expected value of the
p-norm of the vector $(x_iX_i)_{i=1}^n$ is of the order $\| x \|_M$ (up to
constants dependent on p only). In case $p=2$ we need the function $t\mapsto
tM'(t) - M(t)$ to be 2-concave and as an application immediately obtain an
embedding of the corresponding Orlicz spaces into $L_1[0,1]$. We also provide a
general result replacing the $\ell_p$-norm by an arbitrary $N$-norm. This
complements some deep results obtained by Gordon, Litvak, Sch\"utt, and Werner.
We also prove a result in the spirit of their work which is of a simpler form
and easier to apply. All results are true in the more general setting of
Musielak-Orlicz spaces.


title:
Standard Fingerprint Databases: Manual Minutiae Labeling and Matcher
  Performance Analyses

abstract:
  Fingerprint verification and identification algorithms based on minutiae
features are used in many biometric systems today (e.g., governmental e-ID
programs, border control, AFIS, personal authentication for portable devices).
Researchers in industry/academia are now able to utilize many publicly
available fingerprint databases (e.g., Fingerprint Verification Competition
(FVC) & NIST databases) to compare/evaluate their feature extraction and/or
matching algorithm performances against those of others. The results from these
evaluations are typically utilized by decision makers responsible for
implementing the cited biometric systems, in selecting/tuning specific sensors,
feature extractors and matchers. In this study, for a subset of the cited
public fingerprint databases, we report fingerprint minutiae matching results,
which are based on (i) minutiae extracted automatically from fingerprint
images, and (ii) minutiae extracted manually by human subjects. By doing so, we
are able to (i) quantitatively judge the performance differences between these
two cases, (ii) elaborate on performance upper bounds of minutiae matching,
utilizing what can be termed as "ground truth" minutiae features, (iii) analyze
minutiae matching performance, without coupling it with the minutiae extraction
performance beforehand. Further, as we will freely distribute the minutiae
templates, originating from this manual labeling study, in a standard minutiae
template exchange format (ISO 19794-2), we believe that other researchers in
the biometrics community will be able to utilize the associated results &
templates to create their own evaluations pertaining to their fingerprint
minutiae extractors/matchers.


title: The Green rings of the 2-rank Taft algebra and its two relatives twisted

abstract:
  In the paper, the representation rings (or the Green rings) for a family of
Hopf algebras of tame type, the 2-rank Taft algebra (at $q=-1$) and its two
relatives twisted by 2-cocycles are explicitly described via a representation
theoretic analysis. It turns out that the Green rings can serve to detect
effectively the twist-equivalent Hopf algebras here.


title: Spin observables in 71A MeV 6,8He-hydrogen scattering

abstract:
  Predictions of cross sections and analyzing powers using g-folding optical
potentials for the scattering of 71A MeV 6,8He ions from (polarized) hydrogen
are compared with data. A g-folding model in which exchange amplitudes are
evaluated explicitly was used with wave functions of 6,8He specified from a
no-core shell model that used a complete (0+2+4)hw basis. The analyzing powers
reveal some sensitivities to the details of the wave functions, especially in
the case of halo nuclei.


title: Thermal Mass and Plasmino for Strongly Interacting Fermions

abstract:
  We investigate fermion self energy problem in the strongly coupled dense
medium in holographic approach. By working out bottom up models as well as top
down ones we showed that vanishing thermal mass and non-existence of
temperature generated plasmino mode is the universal feature of the strongly
interacting fermion system. We identified that the dual of the bulk Rashiba
effect, which was recently found by the Herzog et.al, is the presence of the
plasmino mode generated by the density.


title: Interatomic exchange interactions in non-collinear magnets

abstract:
  We derive ab inito exchange parameters for general non-collinear magnetic
configurations, in terms of a multiple scattering formalism. We show that the
general exchange formula has an anisotropic-like term even in the absence of
spin-orbit coupling, and that this term is large, for instance for collinear
configuration in bcc Fe, whereas for fcc Ni it is quite small. We demonstrate
that keeping this term leads to that one should consider a biquadratic
effective spin Hamiltonian even in case of collinear arrangement. In
non-collinear systems this term results in new tensor elements, that are
important for exchange interactions at finite temperatures but they have less
importance at low temperature. To illustrate our results in practice, we
calculate for bcc Fe magnon spectra obtained from configuration dependent
exchange parameters, where the configurations are determined by finite
temperature effects. Our theory results in the same quantitative results as the
finite temperature neutron scattering experiments.


title: Collisionless Hydrodynamics of Doped Graphene in a Magnetic Field

abstract:
  The electrodynamics of a two-dimensional gas of massless fermions in graphene
is studied by a collisionless hydrodynamic approach. A low-energy dispersion
relation for the collective modes (plasmons) is derived both in the absence and
in the presence of a perpendicular magnetic field. The results for graphene are
compared to those for a standard two-dimensional gas of massive electrons. We
further compare the results within the classical hydrodynamic approach to the
full quantum mechanical calculation in the random phase approximation. The
low-energy dispersion relation is shown to be a good approximation at small
wave vectors. The limitations of this approach at higher order is also
discussed.


title: Reaction mechanism in odd-even staggering of reaction cross sections

abstract:
  It was recently suggested that the odd-even staggering of reaction cross
sections is an evidence of the pair- ing anti-halo effect on projectile radii.
We define the dimensionless staggering parameters, {\Gamma}rds and {\Gamma}R,
for projectile radii and reaction cross sections, respectively, and analyze the
relation between {\Gamma}rds and {\Gamma}R for the scattering of 14,15,16C from
a 12C target at 83 MeV/A by taking account of projectile-breakup and nuclear-
medium effects newly with the microscopic version of the continuum discretized
coupled-channels method. The value of {\Gamma}R is deviated from that of
{\Gamma}rds by the projectile-breakup effect, the nuclear-medium effect and an
effect due to the fact that the scattering are not the black-sphere scattering
(BSS) exactly. The projectile-breakup and nuclear medium effects are nearly
canceled for {\Gamma}R. The remaining non-BSS effect becomes small as an
incident energy decreases, indicating that nucleus-nucleus scattering at lower
incident energies are a good probe of evaluating {\Gamma}rds from measured
reaction cross sections.


title:
Magnetic Fields in the Large Scale Structure from Faraday Rotation
  measurements

abstract:
  We search for magnetic fields outside galaxies and galaxy clusters by
investigating redshift evolution of Faraday rotation measures (RM) of
extragalactic radio sources. Our analysis reveals a strong evidence for the
redshift dependence of the mean of the absolute value of the RM. The evidence
is further strengthened if the Galactic contribution to the RM is subtracted.
The hypothesis of the absence of the redshift evolution of residual RM is ruled
out at 5 sigma level. The observed redshift dependence of RM is consistent with
the possibility of the presence of nano-Gauss strength magnetic fields with
correlation length shorter than 0.1 Mpc in the weakly overdense elements of the
Large Scale Structure traced by the Ly-alpha clouds.


title: Explicit bounds for graph minors

abstract:
  Let $\Sigma$ be a surface with boundary $b(\Sigma)$, $\mathcal{L}$ be a
collection of $k$ disjoint $b(\Sigma)$-paths in $\Sigma$, and $P$ be a
non-separating $b(\Sigma)$-path in $\Sigma$. We prove that there is a
homeomorphism $\phi: \Sigma \to \Sigma$ that fixes each point of $b(\Sigma)$
and such that $\phi(\mathcal{L})$ meets $P$ at most $2k$ times.
  With this theorem, we derive explicit constants in the graph minor algorithms
of Robertson and Seymour. We reprove a result concerning redundant vertices for
graphs on surfaces, but with explicit bounds. That is, we prove that there
exists a computable integer $t:=t(\Sigma,k)$ such that if $v$ is a
'$t$-protected' vertex in a surface $\Sigma$, then $v$ is redundant with
respect to any $k$-linkage.


title:
A subalgebra of the Hardy algebra relevant in control theory and its
  algebraic-analytic properties

abstract:
  We denote by A_0+AP_+ the Banach algebra of all complex-valued functions f
defined in the closed right half plane, such that f is the sum of a holomorphic
function vanishing at infinity and a ``causal'' almost periodic function. We
give a complete description of the maximum ideal space M(A_0+AP_+) of A_0+AP_+.
Using this description, we also establish the following results:
  (1) The corona theorem for A_0+AP_+.
  (2) M(A_0+AP_+) is contractible (which implies that A_0+AP_+ is a projective
free ring).
  (3) A_0+AP_+ is not a GCD domain.
  (4) A_0+AP_+ is not a pre-Bezout domain.
  (5) A_0+AP_+ is not a coherent ring.
  The study of the above algebraic-anlaytic properties is motivated by
applications in the frequency domain approach to linear control theory, where
they play an important role in the stabilization problem.


title: Jung's Theorem and fixed points for $p$-uniformly convex spaces

abstract:
  We introduce the classical Jung theorem and fixed point theorems and prove
similar ones for $p$-uniformly convex spaces.


title:
A constrained tropical optimization problem: complete solution and
  application example

abstract:
  The paper focuses on a multidimensional optimization problem, which is
formulated in terms of tropical mathematics and consists in minimizing a
nonlinear objective function subject to linear inequality constraints. To solve
the problem, we follow an approach based on the introduction of an additional
unknown variable to reduce the problem to solving linear inequalities, where
the variable plays the role of a parameter. A necessary and sufficient
condition for the inequalities to hold is used to evaluate the parameter,
whereas the general solution of the inequalities is taken as a solution of the
original problem. Under fairly general assumptions, a complete direct solution
to the problem is obtained in a compact vector form. The result is applied to
solve a problem in project scheduling when an optimal schedule is given by
minimizing the flow time of activities in a project under various activity
precedence constraints. As an illustration, a numerical example of optimal
scheduling is also presented.


title: Large Sets of $t$-Designs over Finite Fields

abstract:
  A $t\text{-}(n,k,\lambda;q)$-design is a set of $k$-subspaces, called blocks,
of an $n$-dimensional vector space $V$ over the finite field with $q$ elements
such that each $t$-subspace is contained in exactly $\lambda$ blocks. A
partition of the complete set of $k$-subspaces of $V$ into disjoint
$t\text{-}(n,k,\lambda;q)$ designs is called a large set of $t$-designs over
finite fields. In this paper we give the first nontrivial construction of such
a large set with $t\ge2$.


title: Sphaleron solutions of the Skyrme model from Yang-Mills holonomy

abstract:
  We discuss how an approximation to the axially symmetric sphalerons in the
Skyrme model can be constructed from the holonomy of a non-BPS Yang-Mills
calorons. These configurations, both in the Skyrme model and in the Euclidean
Yang-Mills theory, are characterized by two integers n and m, where n are the
winding numbers of the constituents and the second integer m defines type of
the solution, it has zero topological charge for even m and for odd values of m
the corresponding chain has total topological charge n. It is found numerically
that the holonomy of the chains of interpolating calorons--anticalorons
provides a reasonably good approximation to the corresponding
Skyrmion--antiSkyrmion chains when the topological charge of the Skyrmion
constitutents is two times more than the Chern-Pontryagin index of the caloron.


title: Search for $Z'$ via $ZH$ associated production at LHC

abstract:
  Many new physics models predict the existence of extra neutral gauge bosons
($Z'$). Inspired by the recent development on Higgs search, we study the
properties of $Z'$ via the Higgs and $Z$ boson associated production. The
couplings of $Z'$ to quarks can be investigated through $pp \to Z'\to ZH\to
l^+l^-b \bar b$ process, which also provides extraordinary signal for
understanding the properties of $Z'ZH$ interaction. The standard model
background processes can be significantly suppressed by adopting appropriate
kinematic cuts. The charged lepton angular distributions are related to the
ratio of chiral couplings of $Z'$ to quarks via $Z'ZH$ interaction.


title:
Non-linear absorption and density dependent dephasing in Rydberg
  EIT-media

abstract:
  Light propagation through an ensemble of ultra-cold Rydberg atoms in
electromagnetically induced transparency (EIT) configuration is studied. In
strongly interacting Rydberg EIT media, non-linear optical effects lead to a
non-trivial dependence of the degree of probe beam attenuation on the medium
density and on its initial intensity. We develop a Monte Carlo rate equation
model that self-consistently includes the effect of the probe beam attenuation
to investigate the steady state of the Rydberg medium driven by two laser
fields. We compare our results to recent experimental data and to results of
other state-of-the-art models for light propagation in Rydberg EIT-media. We
find that for low probe field intensities, our results match the experimental
data best if a density-dependent dephasing rate is included in the model. At
higher probe intensities, our model deviates from other theoretical approaches,
as it predicts a spectral asymmetry together with line broadening. These are
likely due to off-resonant excitation channels, which however have not been
observed in recent experiments. Atomic motion and coupling to additional
Rydberg levels are discussed as possible origins for these deviations.


title:
EURETILE 2010-2012 summary: first three years of activity of the
  European Reference Tiled Experiment

abstract:
  This is the summary of first three years of activity of the EURETILE FP7
project 247846. EURETILE investigates and implements brain-inspired and
fault-tolerant foundational innovations to the system architecture of massively
parallel tiled computer architectures and the corresponding programming
paradigm. The execution targets are a many-tile HW platform, and a many-tile
simulator. A set of SW process - HW tile mapping candidates is generated by the
holistic SW tool-chain using a combination of analytic and bio-inspired
methods. The Hardware dependent Software is then generated, providing OS
services with maximum efficiency/minimal overhead. The many-tile simulator
collects profiling data, closing the loop of the SW tool chain. Fine-grain
parallelism inside processes is exploited by optimized intra-tile compilation
techniques, but the project focus is above the level of the elementary tile.
The elementary HW tile is a multi-processor, which includes a fault tolerant
Distributed Network Processor (for inter-tile communication) and ASIP
accelerators. Furthermore, EURETILE investigates and implements the innovations
for equipping the elementary HW tile with high-bandwidth, low-latency
brain-like inter-tile communication emulating 3 levels of connection hierarchy,
namely neural columns, cortical areas and cortex, and develops a dedicated
cortical simulation benchmark: DPSNN-STDP (Distributed Polychronous Spiking
Neural Net with synaptic Spiking Time Dependent Plasticity). EURETILE leverages
on the multi-tile HW paradigm and SW tool-chain developed by the FET-ACA SHAPES
Integrated Project (2006-2009).


title: The functional analytic foundation of Colombeau algebras

abstract:
  Colombeau algebras constitute a convenient framework for performing nonlinear
operations like multiplication on Schwartz distributions. Many variants and
modifications of these algebras exist for various applications. We present a
functional analytic approach placing these algebras in a unifying hierarchy,
which clarifies their structural properties as well as their relation to each
other.


title: Pairs of quadrics in 11 variables

abstract:
  For non-singular intersections of pairs of quadrics in 11 or more variables,
we prove an asymptotic for the number of rational points in an expanding box.


title:
The shape of the D -> K semileptonic form factor from full lattice QCD
  and V_cs

abstract:
  We present a new study of the form factors for D -> K semileptonic decay from
lattice QCD that allows us to compare the shape of the vector form factor to
experiment and, for the first time, to extract V_cs using results from all
experimental q^2 bins. The valence quarks are implemented with the Highly
Improved Staggered Quark action on MILC configurations that include u, d and s
sea quarks. The scalar and vector currents are nonperturbatively normalised
and, using phased boundary conditions, we are able to cover the full q^2 range
accessible to experiment. Our result is V_cs = 0.963(5)_{expt}(14)_{lattice}.
We also demonstrate that the form factors are insensitive to whether the
spectator quark is u/d or s, which has implications for other decay channels.


title: Relativistische Materie in zwei Raum-Zeit-Dimensionen

abstract:
  Quantum field theory unifies concepts from quantum theory and from special
relativity. Its mathematically rigorous description is quite intricate and is
only partially understood; this is particularly true for the construction of
operators corresponding to measurements at a space-time point or in a bounded
space-time region. We explain this fact in simplified examples on 1+1
dimensional space-time, namely in so-called integrable models. We give a
characterization of local operators by means of the analyticity properties of
their coefficients in a certain series expansion. This also allows us to
explicitly construct examples of local operators.


title:
A measurement of the evolution of Interatomic Coulombic Decay in the
  time domain

abstract:
  During the last 15 years a novel decay mechanism of excited atoms has been
discovered and investigated. This so called ''Interatomic Coulombic Decay''
(ICD) involves the chemical environment of the electronically excited atom: the
excitation energy is transferred (in many cases over long distances) to a
neighbor of the initially excited particle usually ionizing that neighbor. It
turned out that ICD is a very common decay route in nature as it occurs across
van-der-Waals and hydrogen bonds. The time evolution of ICD is predicted to be
highly complex, as its efficiency strongly depends on the distance of the atoms
involved and this distance typically changes during the decay. Here we present
the first direct measurement of the temporal evolution of ICD using a novel
experimental approach.


title:
Nef and Effective Cones on the Moduli Space of Torsion Sheaves on the
  Projective Plane

abstract:
  In this paper, we study the divisor theory of the Simpson moduli space of
semistable sheaves of dimension 1 on the projective plane. We prove that these
spaces are all Mori dream spaces, and calculate their nef cones. We also study
the effective cones of these spaces for most choices of numerical invariants.
As a consequence, we work out precisely when two such spaces are isomorphic.


title: Large matchings in bipartite graphs have a rainbow matching

abstract:
  Let $g(n)$ be the least number such that every collection of $n$ matchings,
each of size at least $g(n)$, in a bipartite graph, has a full rainbow
matching. Aharoni and Berger \cite{AhBer} conjectured that $g(n)=n+1$ for every
$n>1$. This generalizes famous conjectures of Ryser, Brualdi and Stein.
Recently, Aharoni, Charbit and Howard \cite{ACH} proved that
$g(n)\le\lfloor\frac{7}{4}n\rfloor$. We prove that $g(n)\le\lfloor\frac{5}{3}
n\rfloor$.


title:
Charmonium and $e^+e^-$ pair photoproduction at mid-rapidity in
  ultra-peripheral Pb-Pb collisions at $\sqrt{s_{\rm NN}}$=2.76 TeV

abstract:
  The ALICE Collaboration at the LHC has measured the J/$\psi$ and $\psi^{'}$
photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at
$\sqrt{s_{\rm NN}}=2.76$ TeV. The charmonium is identified via its leptonic
decay for events where the hadronic activity is required to be minimal. The
analysis is based on an event sample corresponding to an integrated luminosity
of about 23 $\mu\rm{b}^{-1}$. The cross section for coherent and incoherent
J/$\psi$ production in the rapidity interval $-0.9<y<0.9$, are
$\mathrm{d}\sigma_{{\rm J}/\psi}^{\rm coh}/\mathrm{d}y =
2.38^{+0.34}_{-0.24}\big(\mathrm{sta+sys}\big)$mb. and $\mathrm{d}\sigma_{{\rm
J}/\psi}^{\rm inc}/\mathrm{d}y =
0.98^{+0.19}_{-0.17}\big(\mathrm{sta+sys}\big)$mb, respectively. The results
are compared to theoretical models for J/$\psi$ production and the coherent
cross section is found to be in good agreement with those models incorporating
moderate nuclear gluon shadowing, such as EPS09 parametrization. In addition
the cross section for the process $\gamma\gamma\rightarrow e^+ e^-$ has been
measured and found to be in agreement with models implementing QED at leading
order.


title: From $SL(5,\mathbb{R})$ Yang-Mills theory to induced gravity

abstract:
  From pure Yang-Mills action for the $SL(5,\mathbb{R})$ group in four
Euclidean dimensions we obtain a gravity theory in the first order formalism.
Besides the Einstein-Hilbert term, the effective gravity has a cosmological
constant term, a curvature squared term, a torsion squared term and a matter
sector. To obtain such geometrodynamical theory, asymptotic freedom and the
Gribov parameter (soft BRST symmetry breaking) are crucial. Particularly,
Newton and cosmological constant are related to these parameters and they also
run as functions of the energy scale. One-loop computations are performed and
the results are interpreted.


title: Entanglement generation in microcavity polariton devices

abstract:
  Entanglement generation in microcavity exciton-polaritons is an interesting
application of the peculiar properties of these half-light/half-matter
quasiparticles. In this paper we theoretically investigate their luminescence
dynamics and entanglement formation in single, double, and triple cavities. We
derive general expressions and selection rules for polariton-polariton
scattering. We evaluate a number of possible parametric scattering schemes in
terms of entanglement, and identify the ones that are experimentally most
promising.


title:
Moment based estimation of supOU processes and a related stochastic
  volatility model

abstract:
  After a quick review of superpositions of OU (supOU) processes, integrated
sup\-OU processes and the supOU stochastic volatility model we estimate these
processes by using the generalized method of moments (GMM). We show that the
GMM approach yields consistent estimators and that it works very well in
practice. Moreover, we discuss the influence of long memory effects.


title:
Attenuation length measurements of liquid scintillator with LabVIEW and
  reliability evaluation of the device

abstract:
  The attenuation length measuring device was constructed by using oscilloscope
and LabVIEW for signal acquisition and processing. The performance of the
device has been tested with a variety of ways, the test results show that the
set-up has a good stability and high precision (sigma/mean reached 0.4
percent). Besides, the accuracy of the measurement system will decrease by
about 17 percent if a filter is used. The attenuation length of
gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10 plus or
minus 0.35 m where Gd-LS was heavily used in Daya Bay Neutrino Experiment. In
addition, one method based on the Beer-Lambert law was proposed to investigate
the reliability of the measurement device, the R-square reached 0.9995.
Moreover, three purification methods for Linear Alkyl Benzene (LAB) production
were compared in the experiment.


title: Quantum fidelity and relative entropy between unitary orbits

abstract:
  Fidelity and relative entropy are two significant quantities in quantum
information theory. We study the quantum fidelity and relative entropy under
unitary orbits. The maximal and minimal quantum fidelity and relative entropy
between two unitary orbits are explicitly derived. The potential applications
in quantum computation and information processing are discussed.


title:
On the variety of planar spirals and their applications in computer
  aided design

abstract:
  In this paper we discuss the variety of planar spiral segments and their
applications in objects in both the real and artificial world. The discussed
curves with monotonic curvature function are well-known in geometric modelling
and computer aided geometric design as fair curves, and they are very
significant in aesthetic shape modelling. Fair curve segments are used for
two-point G1 and G2 Hermite interpolation, as well as for generating aesthetic
splines.


title: A study of the diffusion pattern in N=4 SYM at high energies

abstract:
  In the context of evolution equations and scattering amplitudes in the high
energy limit of the N=4 super Yang-Mills theory we investigate in some detail
the BFKL gluon Green function at next-to-leading order. In particular, we study
its collinear behaviour in terms of an expansion in different angular
components. We also perform a Monte Carlo simulation of the different final
states contributing to such a Green function and construct the diffusion
pattern into infrared and ultraviolet modes and multiplicity distributions,
making emphasis in separating the gluon contributions from those of scalars and
gluinos. We find that the combined role of the non-gluonic degrees of freedom
is to improve the collinear behavior and reduce the diffusion into ultraviolet
regions while not having any effect on the average multiplicities or diffusion
into the infrared. In terms of growth with energy, the non-zero conformal spin
components are mainly driven by the gluon terms in the BFKL kernel. For zero
conformal spin (Pomeron) the effect of the scalar and gluino sectors is to
dramatically push the Green function towards higher values.


title: Domination Polynomials of Graph Products

abstract:
  The domination polynomials of binary graph operations, aside from union, join
and corona, have not been widely studied. We compute and prove recurrence
formulae and properties of the domination polynomials of families of graphs
obtained by various products, ranging from explicit formulae and recurrences
for specific families to more general results. As an application, we show the
domination polynomial is computationally hard to evaluate.


title: ResourceSync: Leveraging Sitemaps for Resource Synchronization

abstract:
  Many applications need up-to-date copies of collections of changing Web
resources. Such synchronization is currently achieved using ad-hoc or
proprietary solutions. We propose ResourceSync, a general Web resource
synchronization protocol that leverages XML Sitemaps. It provides a set of
capabilities that can be combined in a modular manner to meet local or
community requirements. We report on work to implement this protocol for
arXiv.org and also provide an experimental prototype for the English Wikipedia
as well as a client API.


title: Sharp control time for viscoelastic bodys

abstract:
  It is now well understood that equations of viscoelasticity can be seen as
perturbation of wave type equations. This observation can be exploited in
several different ways and it turns out that it is a usefull tool when studying
controllability. Here we compare a viscoelastic system which fills a surface of
a solid region (the string case has already been studied) with its memoryless
counterpart (which is a generalized telegraph equation) in order to prove exact
controllability of the viscoelastic body at precisely the same times at which
the telegraph equation is controllable.
  The comparison is done using a moment method approach to controllability and
we prove, using the perturbations theorems of Paley-Wiener and Bari, that a new
sequence derived from the viscoelastic system is a Riesz sequence, a fact that
implies controllability of the viscoelastic system.
  The results so obtained generalize existing controllability results and
furthermore show that the ``sharp'' control time for the telegraph equation and
the viscoelastic system coincide.


title: Generalised Sphere Decoding for Spatial Modulation

abstract:
  In this paper, Sphere Decoding (SD) algorithms for Spatial Modulation (SM)
are developed to reduce the computational complexity of Maximum-Likelihood (ML)
detectors. Two SDs specifically designed for SM are proposed and analysed in
terms of Bit Error Ratio (BER) and computational complexity.
  Using Monte Carlo simulations and mathematical analysis, it is shown that by
carefully choosing the initial radius the proposed sphere decoder algorithms
offer the same BER as ML detection, with a significant reduction in the
computational complexity.
  A tight closed form expression for the BER performance of SM-SD is derived in
the paper, along with an algorithm for choosing the initial radius which
provides near to optimum performance. Also, it is shown that none of the
proposed SDs are always superior to the others, but the best SD to use depends
on the target spectral efficiency. The computational complexity trade-off
offered by the proposed solutions is studied via analysis and simulation, and
is shown to validate our findings. Finally, the performance of SM-SDs are
compared to Spatial Multiplexing (SMX) applying ML decoder and applying SD.
  It is shown that for the same spectral efficiency, SM-SD offers up to 84%
reduction in complexity compared to SMX-SD, with up to 1 dB better BER
performance than SMX-ML decoder.


title:
Predicting the isospin asymmetry in $B -> K* \gamma$ using holographic
  AdS/QCD Distribution Amplitudes for the K*

abstract:
  We predict the isospin asymmetry as well as the branching ratio for the decay
$B -> K* \gamma$ within QCD factorization using new anti-de Sitter/Quantum
Chromodynamics (AdS/QCD) holographic Distribution Amplitudes (DAs) for the K*
meson. Our prediction for the branching ratio agrees with that obtained using
standard QCD Sum Rules (SR) DAs and with experiment. More interestingly, our
prediction for the isospin asymmetry using the AdS/QCD DA does not suffer from
the end-point divergence encountered when using the corresponding SR DA. We
predict an isospin asymmetry of 3.3 % in agreement with the most recent average
measured value of (5.2 \pm 2.6) % quoted by the Particle Data Group.


title:
Impact of an accurate modeling of primordial chemistry in high
  resolution studies

abstract:
  The formation of the first stars in the Universe is regulated by a sensitive
interplay of chemistry and cooling with the dynamics of a self-gravitating
system. As the outcome of the collapse and the final stellar masses depend
sensitively on the thermal evolution, it is necessary to accurately model the
thermal evolution in high resolution simulations. As previous investigations
raised doubts regarding the convergence of the temperature at high resolution,
we investigate the role of the numerical method employed to model the chemistry
and the thermodynamics. Here we compare the standard implementation in the
adaptive-mesh refinement code \verb|ENZO|, employing a first order backward
differentiation formula (BDF), with the 5th order accurate BDF solver
\verb|DLSODES|. While the standard implementation in \verb|ENZO| shows a strong
dependence on the employed resolution, the results obtained with \verb|DLSODES|
are considerably more robust, both with respect to the chemistry and
thermodynamics, but also for dynamical quantities such as density, total energy
or the accretion rate. We conclude that an accurate modeling of the chemistry
and thermodynamics is central for primordial star formation.


title: Generalization of Risch's Algorithm to Special Functions

abstract:
  Symbolic integration deals with the evaluation of integrals in closed form.
We present an overview of Risch's algorithm including recent developments. The
algorithms discussed are suited for both indefinite and definite integration.
They can also be used to compute linear relations among integrals and to find
identities for special functions given by parameter integrals. The aim of this
presentation is twofold: to introduce the reader to some basic ideas of
differential algebra in the context of integration and to raise awareness in
the physics community of computer algebra algorithms for indefinite and
definite integration.


title: Entanglement in quantum impurity problems is non perturbative

abstract:
  We study the entanglement entropy of a region of length 2L with the remainder
of an infinite one dimensional gapless quantum system in the case where the
region is centered on a quantum impurity. The coupling to this impurity is not
scale invariant, and the physics involves a crossover between weak and strong
coupling regimes. While the impurity contribution to the entanglement has been
computed numerically in the past, little is known analytically about it, since
in particular the methods of conformal invariance cannot be applied because of
the presence of a crossover length. We show in this paper that the small
coupling expansion of the entanglement entropy in this problem is quite
generally plagued by strong infrared divergences, implying a non-perturbative
dependence on the coupling. The large coupling expansion turns out to be better
behaved, thanks to powerful results from the boundary CFT formulation and, in
some cases, the underlying integrability of the problem. However, it is clear
that this expansion does not capture well the crossover physics. In the
integrable case -- which includes problems such as an XXZ chain with a modified
link, the interacting resonant level model or the anisotropic Kondo model -- a
non perturbative approach is in principle possible using form-factors. We adapt
in this paper the ideas of [1,2] to the gapless case and show that, in the
rather simple case of the resonant level model, and after some additional
renormalizations, the form factors approach yields remarkably accurate results
for the entanglement all the way from short to large distances. This is
confirmed by detailed comparison with numerical simulations. Both our form
factor and numerical results are compatible with a non-perturbative form at
short distance.


title:
Analyzing the citation characteristics of books: edited books, book
  series and types of publishers in the Book Citation Index

abstract:
  This paper presents a first approach to analyzing the factors that determine
the citation characteristics of books. For this we use the Thomson Reuters'
Book Citation Index, a novel multidisciplinary database launched in 2010 which
offers bibliometric data of books. We analyze three possible factors which are
considered to affect the citation impact of books: the presence of editors, the
inclusion in series and the type of publisher. Also, we focus on highly cited
books to see if these factors may affect them as well. We considered as highly
cited books, those in the top 5% of the most highly cited ones of the database.
We define these three aspects and we present the results for four major
scientific areas in order to identify field-based differences (Science,
Engineering & Technology, Social Sciences and Arts & Humanities). Finally we
conclude observing that differences were noted for edited books and types of
publishers. Although books included in series showed higher impact in two
areas.


title: Conformal and gauge invariant spin-2 field equations

abstract:
  Using an approach based on the Casimir operators of the de Sitter group, the
conformal invariant equations for a fundamental spin-2 field are obtained, and
their consistency discussed. It is shown that, only when the spin-2 field is
interpreted as a 1-form assuming values in the Lie algebra of the translation
group, rather than a symmetric second-rank tensor, the field equation is both
conformal and gauge invariant.


title:
Extreme value statistics of the weak lensing convergence: 1. primordial
  non-Gaussianities

abstract:
  The subject of this paper is the investigation of inflationary
non-Gaussianities of the local type with extreme value statistics of the weak
lensing convergence kappa. Specifically, we describe the influence of
inflationary non-Gaussianities parameterised by fnl and gnl on the probability
distribution p(kappa)dkappa of the smoothed convergence field with a
Gram-Charlier series, for which we compute the cumulants kappa_n of the
smoothed convergence field as a configuration space average of the weak
convergence polyspectra. We derive analytical expressions for the extreme value
distribution and show that they correspond very well to direct samples of
extreme values from the Gram-Charlier distribution. We show how the standard
Gumbel distribution for the extreme values is recovered in the limit of large
sample size. We investigate the shape and position of the extreme value
distribution for fnl- and gnl-type non-Gaussianity and quantify the dependence
on the number of available samples, leading to the inference of non-Gaussianity
parameters from observed extreme values. From the observation of single extreme
values in the EUCLID weak lensing survey is is possible to place constraints on
fnl and gnl of the order 10^2 and 10^5, respectively, while tnl can not be
constrained in a meaningful way.


title:
Two-Dimensional Ferroelectric Photonic Crystals: Optics and Band
  Structure

abstract:
  In this report we present an investigation of the optical properties and band
structure calculations for the photonic structures based on the functional
materials- ferroelectrics. A theoretical approach to the optical properties of
the 2D and 3D photonic crystals which yields further insight in the phenomenon
of the reflection from different families of lattice planes in relation to the
presence of photonic gaps or photonic bands. We calculate the photonic bands
and optical properties of LiNbO3 based photonic crystals. Calculations of
reflection and transmission spectra show the features correspond to the onset
of diffraction, as well as to additional reflectance structures at large values
of the angle of incidence.


title: Shape Dynamics and Effective Field Theory

abstract:
  Shape Dynamics is a gauge theory based on spatial diffeomorphism- and
Weyl-invariance which is locally indistinguishable form classical General
Relativity. If taken seriously, it suggests that the spacetime--geometry
picture that underlies General Relativity can be replaced by a picture based on
spatial conformal geometry. This classically well understood trading of gauge
symmetries opens new conceptual avenues in many approaches to quantum gravity.
I focus on the general implications for quantum gravity and effective field
theory and consider the application of the Shape Dynamics picture in the exact
renormalization group approaches to gravity, loop- and polymer- quantization
approaches to gravity and low energy effective field theories. I also discuss
the interpretation of known results through in the Shape Dynamics picture, in
particular holographic renormalization and the problem of time in canonical
quantum gravity.


title:
Most borrowed is most cited? Library loan statistics as a proxy for
  monograph selection in citation indexes

abstract:
  This study aims to analyse whether library loans statistics can be used as a
measure of monograph use and as a selection criteria for inclusion in citation
indexes. For this, we conducted an exploratory study based on loan data (1000
most borrowed monographs) from two non-Anglo-Saxon European university
libraries (Granada and Vienna) with strong social sciences and humanities
components. Loans to scientists only were also analysed at the University of
Vienna. Furthermore, citation counts for the 100 most borrowed scientific
monographs (SM) and textbooks or manuals (MTB) were retrieved from Web of
Science and Google Scholar. The results show considerable similarities in both
libraries: the percentage of loans for books in national languages represents
almost 96 per cent of the total share and SM accounts only for 10 to 13 per
cent. When considering loans to scientists only, the percentage of English
books increases to 30 per cent, the percentage of SM loans also increases
(approx 80 per cent). Furthermore, we found no significant correlations between
loans and citations. Since loan statistics are currently insufficient for
measuring the use of monographs, their suggested use as an applicable selection
criterion for book citation indexes is not yet feasible. Data improvement and
aggregation at different levels is a challenge for modern libraries in order to
enable the exploitation of this invaluable information source for scientometric
purposes.


title: Matlab tools for HDG in three dimensions

abstract:
  In this paper we provide some Matlab tools for efficient vectorized coding of
the Hybridizable Discontinuous Galerkin for linear variable coefficient
reaction-diffusion problems in polyhedral domains. The resulting tools are
modular and include enhanced structures to deal with convection-diffusion
problems, plus several projections and a superconvergent postprocess of the
solution. Loops over the elements are exclusively local and, as such, have been
parallelized.


title:
Degrees of Freedom of Certain Interference Alignment Schemes with
  Distributed CSIT

abstract:
  In this work, we consider the use of interference alignment (IA) in a MIMO
interference channel (IC) under the assumption that each transmitter (TX) has
access to channel state information (CSI) that generally differs from that
available to other TXs. This setting is referred to as distributed CSIT. In a
setting where CSI accuracy is controlled by a set of power exponents, we show
that in the static 3-user MIMO square IC, the number of degrees-of-freedom
(DoF) that can be achieved with distributed CSIT is at least equal to the DoF
achieved with the worst accuracy taken across the TXs and across the
interfering links. We conjecture further that this represents exactly the DoF
achieved. This result is in strong contrast with the centralized CSIT
configuration usually studied (where all the TXs share the same, possibly
imperfect, channel estimate) for which it was shown that the DoF achieved at
receiver (RX) i is solely limited by the quality of its own feedback. This
shows the critical impact of CSI discrepancies between the TXs, and highlights
the price paid by distributed precoding.


title: The Gauss map of surfaces in ~PSL_2(R)

abstract:
  We define a Gauss map for surfaces in the universal cover of the Lie group
PSL_2(R) endowed with a left-invariant Riemannian metric having a 4-dimensional
isometry group. This Gauss map is not related to the Lie group structure. We
prove that the Gauss map of a nowhere vertical surface of critical constant
mean curvature is harmonic into the hyperbolic plane H^2 and we obtain a
Weierstrass-type representation formula. This extends results in H^2 x R and
the Heisenberg group Nil_3, and completes the proof of existence of harmonic
Gauss maps for surfaces of critical constant mean curvature in any homogeneous
manifold diffeomorphic to R^3 with isometry group of dimension at least 4.


title:
Sharp martingale inequalities and applications to Riesz transforms on
  manifolds, Lie groups and Gauss space

abstract:
  We prove new sharp $L^p$, logarithmic, and weak-type inequalities for
martingales under the assumption of differentially subordination. The $L^p$
estimates are "Fyenman-Kac" type versions of Burkholder's celebrated martingale
transform inequalities. From the martingale $L^p$ inequalities we obtain that
Riesz transforms on manifolds of nonnegative Bakry-Emery Ricci curvature have
exactly the same $L^p$ bounds as those known for Riesz transforms in the flat
case of $\R^n$. From the martingale logarithmic and weak-type inequalities we
obtain similar inequalities for Riesz transforms on compact Lie groups and
spheres. Combining the estimates for spheres with Poincar\'e's limiting
argument, we deduce the corresponding results for Riesz transforms associated
with the Ornstein-Uhlenbeck semigroup, thus providing some extensions of P.A.
Meyer's $L^p$ inequalities.


title:
RHESSI and TRACE observations of multiple flare activity in AR 10656 and
  associated filament eruption

abstract:
  We present RHESSI and TRACE observations of multiple flare activity that
occurred in the active region NOAA 10656 over the period of two hours on 2004
August 18. Out of four successive flares, there were three events of class C
while the final event was a major X1.8 solar eruptive flare. The events during
the pre-eruption phase, i.e., before the X1.8 flare, are characterized by
localized episodes of energy release occurring in the vicinity of an active
region filament which produced intense heating along with non-thermal emission.
A few minutes before the eruption, the filament undergoes an activation phase
during which it slowly rises with a speed of ~12 km/s. The filament eruption is
accompanied with an X1.8 flare during which multiple HXR bursts are observed up
to 100-300 keV energies. We observe a bright and elongated coronal structure
simultaneously in E(UV) and 50-100 keV HXR images underneath the expanding
filament during the period of HXR bursts which provides strong evidence for
ongoing magnetic reconnection. This phase is accompanied with very high plasma
temperatures of ~31 MK and followed by the detachment of the prominence from
the solar source region. From the location, timing, strength, and spectrum of
HXR emission, we conclude that the prominence eruption is driven by the
distinct events of magnetic reconnection occurring in a current sheet formed
below the erupting filament. These multi-wavelength observations also suggest
that the localized magnetic reconnections associated with different
evolutionary stages of the filament in the pre-eruption phase play a crucial
role in destabilizing the filament by a tether-cutting process leading to
large-scale eruption and X-class flare.