title:
Killed Markov Decision Processes on Finite Time Interval for Countable
  Models

abstract:
  We consider killed Markov decision processes for countable models on a finite
time-interval. Existence of a uniform $\varepsilon$-optimal policy is proven.
We show the correctness of the fundamental equation. The optimal control
problem is reduced to a similar problem for the derived model. We receive an
optimality equation and a method for the construction of simple optimal
policies. The sufficiency of simple policies for countable models is proven. We
show the correctness of the Markovian property. Additionally, a dynamic
programming principle is considered.


title:
The Peierls-Onsager Effective Hamiltonian in a complete gauge covariant
  setting: Description of the spectrum

abstract:
  Using the procedures in \cite{Bu} and \cite{GMS} and the magnetic
pseudodifferential calculus we have developped in \cite{MP1,MPR1,IMP1,IMP2} we
construct an effective Hamitonian that describes the spectrum in any compact
subset of the real axis for a large class of periodic pseudodifferential
Hamiltonians in a bounded smooth magnetic field, in a completely gauge
covariant setting, without any restrictions on the vector potential and without
any adiabaticity hypothesis.


title: Effect of pairing on nuclear dynamic

abstract:
  The effect of pairing on small and large amplitude dynamics is discussed.
Pairing correlation is treated in a fully microscopic transport theory using a
simplified BCS version of the Time-Dependent Hartree-Fock Bogolyubov (TDHFB)
theory. The approach is applied to study the Giant Dipole and Giant Quadrupole
Resonance in spherical and/or deformed magnesium isotopes showing very good
agreement with QRPA theory. The present framework also provides a consistent
approach to describe nuclear reactions around the Coulomb barrier. As an
illustration, the influence of pairing correlations on multi-nucleon transfer
is studied for reactions at sub-barrier energy.


title: Closure of principal L-type domain and its parallelotopes

abstract:
  Voronoi defined two polyhedral partitions of the cone of se\mi\de\fi\nite
forms into L-type domains and into perfect domains. Up to equivalence, there is
only one domain that is simultaneously perfect and L-type. Voronoi called this
domain {\em principal}. We show that closure of the principal domain may be
identified with a cone of cut submodular set functions. Parallelotopes of the
closed principal domain are zonotopes that are base polyhedra related to
graphic unimodular sets of vectors.


title:
Unsupervised Post-Nonlinear Unmixing of Hyperspectral Images Using a
  Hamiltonian Monte Carlo Algorithm

abstract:
  This paper presents a nonlinear mixing model for hyperspectral image
unmixing. The proposed model assumes that the pixel reflectances are
post-nonlinear functions of unknown pure spectral components contaminated by an
additive white Gaussian noise. These nonlinear functions are approximated using
polynomials leading to a polynomial post-nonlinear mixing model. A Bayesian
algorithm is proposed to estimate the parameters involved in the model yielding
an unsupervised nonlinear unmixing algorithm. Due to the large number of
parameters to be estimated, an efficient Hamiltonian Monte Carlo algorithm is
investigated. The classical leapfrog steps of this algorithm are modified to
handle the parameter constraints. The performance of the unmixing strategy,
including convergence and parameter tuning, is first evaluated on synthetic
data. Simulations conducted with real data finally show the accuracy of the
proposed unmixing strategy for the analysis of hyperspectral images.


title:
Existence and stability of a screw dislocation under anti-plane
  deformation

abstract:
  We formulate a variational model for a geometrically necessary screw
dislocation in an anti-plane lattice model at zero temperature. Invariance of
the energy functional under lattice symmetries renders the problem
non-coercive. Nevertheless, by establishing coercivity with respect to the
elastic strain and a concentration compactness principle, we prove existence of
a global energy minimiser and thus demonstrate that dislocations are globally
stable equilibria within our model.


title:
On the existence of bounded solutions for nonlinear second order neutral
  difference equations

abstract:
  \noindent Using the techniques connected with the measure of noncompactness
we investigate the neutral difference equation of the following form
\begin{equation*} \Delta \left(r_{n}\left(\Delta
\left(x_{n}+p_{n}x_{n-k}\right) \right) ^{\gamma}\right)
+q_{n}x_{n}^{\alpha}+a_{n}f(x_{n})=0. \end{equation*}% where
$x:{\mathbb{N}}_{0}\rightarrow {\mathbb{R}}$,
$a,p,q:{\mathbb{N}}%_{0}\rightarrow {\mathbb{R}}$,
$r:{\mathbb{N}}_{0}\rightarrow {\mathbb{R}}% \setminus \{0\}$, $f\colon
{\mathbb{R}}\rightarrow {\mathbb{R}}$ is a continuous function, and $k$ is a
given positive integer, $\gamma \leq 1$ is ratio of odd positive integers,
$\alpha $ is a nonnegative constant. %$\sum a_{n}\left(t\right)$ converges
uniformly on ${\mathbb{R}}$. %Here $\bN_0\colon =\left\{0,1,2, \dots \right\}$
and $\bN_k \colon = \left\{k, k+1, -k+2, \dots \right\}$ where $k$ is a given
positive integer. Sufficient conditions for the existence of a bounded solution
are obtained. Also a special type of stability and asymptotic stability are
studied. Some earlier results are generalized. We note that the solution which
we obtain does not directly correspond to a fixed point of a certain continuous
operator since it is partially iterated. The method which we develop allows for
considering through techniques connected with the measure of noncompactness
also difference equations with memory. {\small \textbf{Keywords} Difference
equation, measures of noncompactness, Darbo's fixed point theorem, boundedness,
stability} {\small \textbf{AMS Subject classification} 39A10, 39A22, 39A30}


title: Optimization Parameter Design of a Circular e+e- Higgs Factory

abstract:
  In this paper we will show a general method of how to make an optimized
parameter design of a circular e+e- Higgs Factory by using analytical
expression of maximum beam-beam parameter and beamstrahlung beam lifetime
started from given design goal and technical limitations. A parameter space has
been explored. Based on beam parameters scan and RF parameters scan, a set of
optimized parameter designs for 50 km Circular Higgs Factory (CHF) with
different RF frequency was proposed.


title: Simulating the Smart Grid

abstract:
  Major challenges for the transition of power systems do not only tackle power
electronics but also communication technology, power market economy and user
acceptance studies. Simulation is an important research method therein, as it
helps to avoid costly failures. A common smart grid simulation platform is
still missing. We introduce a conceptual model of agents in multiple flow
networks. Flow networks extend the depth of established power flow analysis
through use of networks of information flow and financial transactions. We use
this model as a basis for comparing different power system simulators.
Furthermore, a quantitative comparison of simulators is done to facilitate the
decision for a suitable tool in comprehensive smart grid simulation.


title: A New Access Control Scheme for Facebook-style Social Networks

abstract:
  The popularity of online social networks (OSNs) makes the protection of
users' private information an important but scientifically challenging problem.
In the literature, relationship-based access control schemes have been proposed
to address this problem. However, with the dynamic developments of OSNs, we
identify new access control requirements which cannot be fully captured by the
current schemes. In this paper, we focus on public information in OSNs and
treat it as a new dimension which users can use to regulate access to their
resources. We define a new OSN model containing users and their relationships
as well as public information. Based on this model, we introduce a variant of
hybrid logic for formulating access control policies. We exploit a type of
category information and relationship hierarchy to further extend our logic for
its usage in practice. In the end, we propose a few solutions to address the
problem of information reliability in OSNs, and formally model collaborative
access control in our access control scheme.


title: An improved Talbot method for numerical Laplace transform inversion

abstract:
  The classical Talbot method for the computation of the inverse Laplace
transform is improved for the case where the transform is analytic in the
complex plane except for the negative real axis. First, by using a truncated
Talbot contour rather than the classical contour that goes to infinity in the
left half-plane, faster convergence is achieved. Second, a control mechanism
for improving numerical stability is introduced. These two features are
incorporated into a software code, whose performance is assessed on transforms
from tables as well as from actual applications. It is shown that even when the
transform has singularities off the negative real axis, rapid convergence can
still be achieved in many cases.


title: Nonsymmetric generic matrix equations

abstract:
  Let $(A_i)_{0\leq i\leq k}$ be generic matrices over $\mathbb{Q}$, the field
of rational numbers. Let $K=\mathbb{Q}(E)$, where $E$ denotes the entries of
the $(A_i)_i$, and let $\overline{K}$ be the algebraic closure of $K$. We show
that the generic unilateral equation $A_kX^k+\cdots+A_1X+A_0=0_n$ has
$\binom{nk}{n}$ solutions $X\in\mathcal{M}_n(\overline{K})$. Solving the
previous equation is equivalent to solving a polynomial of degree $kn$, with
Galois group $S_{kn}$ over $K$. Let $(B_i)_{i\leq k}$ be fixed $n\times n$
matrices with entries in a field $L$. We show that, for a generic
$C\in\mathcal{M}_n(L)$, a polynomial equation $g(B_1,\cdots,B_k,X)=C$ admits a
finite fixed number of solutions and these solutions are simple. We study, when
$n=2$, the generic non-unilateral equations $X^2+BXC+D=0_2$ and
$X^2+BXB+C=0_2$. We consider the unilateral equation
$X^k+C_{k-1}X^{k-1}+\cdots+C_1X+C_0=0_n$ when the $(C_i)_i$ are $n\times n$
generic commuting matrices ; we show that every solution
$X\in\mathcal{M}_n(\overline{K})$ commutes with the $(C_i)_i$. When $n=2$, we
prove that the generic equation $A_1XA_2X+XA_3X+X^2A_4+A_5X+A_6=0_2$ admits
$16$ isolated solutions in $\mathcal{M}_2(\overline{K})$, that is, according to
the B\'ezout's theorem, the maximum for a quadratic $2\times 2$ matrix
equation.


title:
Coherent microscopy at resolution beyond diffraction limit using
  post-experimental data extrapolation

abstract:
  Conventional microscopic records represent intensity distributions whereby
local sample information is mapped onto local information at the detector. In
coherent microscopy, the superposition principle of waves holds; field
amplitudes are added, not intensities. This non-local representation is spread
out in space and interference information combined with wave continuity allows
extrapolation beyond the actual detected data. Established resolution criteria
are thus circumvented and hidden object details can retrospectively be
recovered from just a fraction of an interference pattern.


title: A natural scenario for heavy colored and light uncolored superpartners

abstract:
  Influenced by the current trend of experimental data, especially from the
LHC, we construct a supersymmetric scenario where a natural dynamics makes the
squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and
the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion
of two underlying ideas: ($i$) gauge mediation of supersymmetry breaking with
two messenger multiplets, one transforming as a triplet of weak SU(2) and the
other as an octet of color SU(3); ($ii$) perturbative gauge coupling
unification at the string scale even with these incomplete SU(5) multiplets.
Interestingly, the relative magnitude of the triplet and octet messenger scales
that ensures gauge unification at the two-loop level also helps to naturally
keep the uncolored superpartners light while making the colored ones heavy.


title:
Tuning the Ultrafast Spin Dynamics in Carrier-Density-Controlled
  Ferromagnets

abstract:
  Ultrafast strengthening or quenching of the ferromagnetic order of
semiconducting Eu1-xGdxO was achieved by resonant photoexcitation. The
modification of the magnetic order is established within 3 ps as revealed by
optical second harmonic generation. A theoretical analysis shows that the
response is determined by the interplay of chemically and optically generated
carriers in a nonequilibrium scenario beyond the three-temperature model.
General criteria for the design of spintronics materials with tunable ultrafast
spin dynamics are given.


title: Lax operator algebras of type $G_2$

abstract:
  Lax operator algebras for the root system $G_2$, and arbitrary finite genus
Riemann surfaces and Tyurin data on them are constructed.


title:
Consistent coarse-graining strategy for polymer solutions in the thermal
  crossover from Good to Theta solvent

abstract:
  We extend our previously developed coarse-graining strategy for linear
polymers with a tunable number n of effective atoms (blobs) per chain [D'Adamo
et al., J. Chem. Phys. 137, 4901 (2012)] to polymer systems in thermal
crossover between the good-solvent and the Theta regimes. We consider the
thermal crossover in the region in which tricritical effects can be neglected,
i.e. not too close to the Theta point, for a wide range of chain volume
fractions Phi=c/c* (c* is the overlap concentration), up to Phi=30. Scaling
crossover functions for global properties of the solution are obtained by
Monte-Carlo simulations of the Domb-Joyce model. They provide the input data to
develop a minimal coarse-grained model with four blobs per chain. As in the
good-solvent case, the coarse-grained model potentials are derived at zero
density, thus avoiding the inconsistencies related to the use of
state-dependent potentials. We find that the coarse-grained model reproduces
the properties of the underlying system up to some reduced density which
increases when lowering the temperature towards the Theta state. Close to the
lower-temperature crossover boundary, the tetramer model is accurate at least
up to Phi<10, while near the good-solvent regime reasonably accurate results
are obtained up to Phi<2. The density region in which the coarse-grained model
is predictive can be enlarged by developing coarse-grained models with more
blobs per chain. We extend the strategy used in the good-solvent case to the
crossover regime. This requires a proper treatment of the length rescalings as
before, but also a proper temperature redefinition as the number of blobs is
increased. The case n=10 is investigated. Comparison with full-monomer results
shows that the density region in which accurate predictions can be obtained is
significantly wider than that corresponding to the n=4 case.


title: On the algebraic dual of D(\Omega)

abstract:
  This paper is concerned with the algebraic dual D*(\Omega) of the space of
test functions D(\Omega). The emphasis is on failures and successes of
D*(\Omega) as compared to the continuous dual D'(\Omega), the space of
distributions. Topological properties, operations with elements of D*(\Omega)
and applications to linear partial differential equations are discussed.


title:
Multidimensionally-constrained relativistic mean field models and
  potential energy surfaces of actinide nuclei

abstract:
  By breaking both the axial and the spatial reflection symmetries, we develop
multidimensionally constrained relativistic mean field (MDC-RMF) models. The
nuclear shape is assumed to be invariant under the reversion of $x$ and $y$
axes, i.e., the intrinsic symmetry group is $V_{4}$ and all shape degrees of
freedom $\beta_{\lambda\mu}$ with even $\mu$, such as $\beta_{20}$,
$\beta_{22}$, $\beta_{30}$, $\beta_{32}$, $\beta_{40}$, $\dots$, are included
self-consistently. The Dirac wave functions are expanded in an axially deformed
harmonic oscillator basis. The RMF functional can be one of the following four
forms: the meson exchange or point-coupling nucleon interactions combined with
the nonlinear or density-dependent couplings. The pairing effects are taken
into account with the BCS approach. The 1-, 2-, and 3-D potential energy
surfaces (PES's) of $^{240}$Pu are illustrated for numerical checks and for the
study of the effect of the triaxiality on the fission barriers. Potential
energy curves of even-even actinide nuclei around the first and second fission
barriers are studied systematically. Besides the first ones, the second fission
barriers in these nuclei are also lowered considerably by the triaxial
deformation. This lowering effect is independent of the effective interactions
used in the RMF functionals. Further discussions are made about different
predictions on the effect of the triaxiality between the
macroscopic-microscopic and MDC-RMF models, possible discontinuities on PES's
from self-consistent approaches, and the restoration of broken symmetries.
MDC-RMF models give reasonably good description of fission barriers of
even-even actinide nuclei. It is important to include both the nonaxial and the
reflection asymmetric shapes simultaneously for the study of PES's and fission
barriers of actinide nuclei and of those in unknown mass regions such as, e.g.,
superheavy nuclei.


title: Automatic Structuring Of Semantic Web Services An Approach

abstract:
  Ontologies have become the effective modeling for various applications and
significantly in the semantic web. The difficulty of extracting information
from the web, which was created mainly for visualising information, has driven
the birth of the semantic web, which will contain much more resources than the
web and will attach machine-readable semantic information to these resources.
Ontological bootstrapping on a set of predefined sources, such as web services,
must address the problem of multiple, largely unrelated concepts. The web
services consist of basically two components, Web Services Description Language
(WSDL) descriptors and free text descriptors. The WSDL descriptor is evaluated
using two methods, namely Term Frequency/Inverse Document Frequency (TF/IDF)
and web context generation. The proposed bootstrapping ontological process
integrates TF/IDF and web context generation and applies validation using the
free text descriptor service, so that, it offers more accurate definition of
ontologies. This paper uses ranking adaption model which predicts the rank for
a collection of web service documents which leads to the automatic
construction, enrichment and adaptation of ontologies.


title: On the regularity and Koszulness of modules over local rings

abstract:
  Koszul modules over Noetherian local rings $R$ were introduced by Herzog and
Iyengar and they possess good homological properties, for instance their
Poincare' series is rational. It is an interesting problem to characterize
classes of Koszul modules. Following the idea traced by Avramov, Iyengar and
Sega, we take advantage of the existence of special filtration on $R$ for
proving that large classes of $R$-modules over Koszul rings are Koszul modules.
By using this tool we reprove and extend some results obtained by Fitzgerald.


title: Magnetic Field Focusing of Hyperfine Interaction in Hydrogen

abstract:
  We find a new correction to the hydrogen atom ground state hyperfine energy
levels splitting in magnetic field. It can be interpreted as magnetic focusing
of the wave function at the origin. The effect might be within the reach of
experiment.


title: Castelnuovo-Mumford regularity and cohomological dimension

abstract:
  Let $R=\oplus_{i\in \N_0}R_n$ be a standard graded ring, $R_+ :=\oplus_{i\in
\N}R_n$ be the irrelevant ideal of $R$ and $\fa_0$ be an ideal of $R_0$. In
this paper, as a generalization of the concept of Castelnouvo-Mumford
regularity $\reg(M)$ of a finitely generated graded $R$-module $M$, we define
the regularity of $M$ with respect to $\fa_0+ R_+$, say $\reg_{\fa_0+ R_+}(M)$.
And we study some relations of this new invariant with the classic one. To this
end, we need to consider the cohomological dimension of some finitely generated
$R_0$-modules. Also, we will express $\reg_{\fa_0+ R_+}(M)$ in terms of some
invariants of the minimal graded free resolution of $M$ and see that in a
special case this invariant is independent of the choice of $\fa_0$.


title: Reversals of Gnevyshev-Ohl rule

abstract:
  This paper considers the changes of average number of sunspots groups per
day, aggregated by activity cycles Gn within the period since 1610 till present
time. The relation of parameter Gn of the preceding and the following activity
cycles has a long-term variation with the period of about 20 activity cycles.
There is a positive correlation between the parameter Gn in the current cycle
and analogous parameter in the following cycle Gn+1. For cycles N 10-21 for a
pair of even and odd cycles the relation of parameter Gn corresponds to
Gnevyshev-Ohl rule Godd/Geven>1. But in previous epochs the odd cycles could be
less than the preceding even cycles, and it only proves the reversal of
Gnevyshev-Ohl rule.


title: Nonlinear subdiffusive fractional equations and aggregation phenomenon

abstract:
  In this article we address the problem of the nonlinear interaction of
subdiffusive particles. We introduce the random walk model in which statistical
characteristics of a random walker such as escape rate and jump distribution
depend on the mean field density of particles. We derive a set of nonlinear
subdiffusive fractional master equations and consider their diffusion
approximations. We show that these equations describe the transition from an
intermediate subdiffusive regime to asymptotically normal advection-diffusion
transport regime. This transition is governed by nonlinear tempering parameter
that generalizes the standard linear tempering. We illustrate the general
results through the use of the examples from cell and population biology. We
find that a nonuniform anomalous exponent has a strong influence on the
aggregation phenomenon.


title: A functorial formalism for quasi-coherent sheaves on a geometric stack

abstract:
  A geometric stack is a quasi-compact and semi-separated algebraic stack. We
prove that the quasi-coherent sheaves on the small flat topology, Cartesian
presheaves on the underlying category, and comodules over a Hopf algebroid
associated to a presentation of a geometric stack are equivalent categories. As
a consequence, we show that the category of quasi-coherent sheaves on a
geometric stack is a Grothendieck category.
  We associate, in a 2-functorial way, to a 1-morphism of geometric stacks $f$,
an adjunction $(f^*, f_*)$ for the corresponding categories of quasi-coherent
sheaves that agrees with the classical one defined for schemes. This
construction is described both geometrically in terms of the small flat site
and algebraically in terms of the Hopf algebroid.


title:
Observation of neutron bursts produced by laboratory high-voltage
  atmospheric discharge

abstract:
  Data on the observation of neutron bursts in the process of high-voltage
discharge in the air at an average electric field strength ~ 1 MV/m and
discharge current ~ 10 kA are presented. Two independent methods (CR-39 track
detectors and plastic scintillation detectors) registered neutrons within the
range from thermal energies up to the energies above 10 MeV with the flux of >=
1E6 neutrons per shot into 4{\pi} solid angle.


title:
Effective field theory for the Ising model with a fluctuating exchange
  integral in an asymmetric bimodal random magnetic field: A differential
  operator technique

abstract:
  The spin-1/2 Ising model on a square lattice, with fluctuating bond
interactions between nearest neighbors and in the presence of a random magnetic
field, is investigated within the framework of the effective field theory based
on the use of the differential operator relation. The random field is drawn
from the asymmetric and anisotropic bimodal probability distribution
$P(h_{i})=p \delta(h_{i}-h_{1}) + q \delta (h_{i}+ ch_{1})$, where the site
probabilities $p,q$ take on values within the interval $[0,1]$ with the
constraint $p+q=1$; $h_{i}$ is the random field variable with strength $h_{1}$
and $c$ the competition parameter, which is the ratio of the strength of the
random magnetic field in the two principal directions $+z$ and $-z$; $c$ is
considered to be positive resulting in competing random fields. The fluctuating
bond is drawn from the symmetric but anisotropic bimodal probability
distribution $P(J_{ij})=\frac{1}{2}\{\delta(J_{ij}-(J+\Delta)) + \delta
(J_{ij}-(J-\Delta))\}$, where $J$ and $\Delta$ represent the average value and
standard deviation of $J_{ij}$, respectively. We estimate the transition
temperatures, phase diagrams (for various values of system's parameters
$c,p,h_{1},\Delta$), susceptibility, equilibrium equation for magnetization,
which is solved in order to determine the magnetization profile with respect to
$T$ and $h_{1}$.


title: Communication over Finite-Chain-Ring Matrix Channels

abstract:
  Though network coding is traditionally performed over finite fields, recent
work on nested-lattice-based network coding suggests that, by allowing network
coding over certain finite rings, more efficient physical-layer network coding
schemes can be constructed. This paper considers the problem of communication
over a finite-ring matrix channel $Y = AX + BE$, where $X$ is the channel
input, $Y$ is the channel output, $E$ is random error, and $A$ and $B$ are
random transfer matrices. Tight capacity results are obtained and simple
polynomial-complexity capacity-achieving coding schemes are provided under the
assumption that $A$ is uniform over all full-rank matrices and $BE$ is uniform
over all rank-$t$ matrices, extending the work of Silva, Kschischang and
K\"{o}tter (2010), who handled the case of finite fields. This extension is
based on several new results, which may be of independent interest, that
generalize concepts and methods from matrices over finite fields to matrices
over finite chain rings.


title: Relative Positions of Countries in the World of Science

abstract:
  A novel picture of the relative positions of countries in the world of
science is offered through application of a two-dimensional mapping method
which is based on quantity and quality indicators of the scientific production
as peer-reviewed articles. To obtain such indicators, different influential
effects such as the background global trends, temporal fluctuations,
disciplinary characteristics, and mainly, the effect of countries resources
have been taken into account. Fifty countries with the highest scientific
production are studied in twelve years (1996-2007). A common clustering
algorithm is used to detect groups of co-evolving countries in the
two-dimensional map, and thereby countries are classified into four major
clusters based on their relative positions in the two-dimensional map. The
final results are in contrast with common views on relative positions of
countries in the world of science, as demonstrated by considering some examples
like USA, China or New Zealand. The proposed method and results thereof might
influence the concept of 'scientific advancement' and the future scientific
orientations of countries.


title:
The random field Ising model with an asymmetric and anisotropic trimodal
  probability distribution

abstract:
  The Ising model in the presence of a random field, drawn from the asymmetric
and anisotropic trimodal probability distribution $P(h_{i})=p\;
\delta(h_{i}-h_{0}) + q \delta (h_{i}+ \lambda *h_{0}) + r \delta (h_{i})$, is
investigated. The partial probabilities $p, q, r$ take on values within the
interval $[0,1]$ consistent with the constraint $p+q+r=1$, asymmetric
distribution, $h_{i}$ is the random field variable with basic absolute value
$h_{0}$ (strength); $\lambda$ is the competition parameter, which is the ratio
between the respective strength of the random magnetic field in the two
principal directions $(+z)$ and $(-z)$ and is positive so that the random
fields are competing, anisotropic distribution. This probability distribution
is an extension of the bimodal one allowing for the existence in the lattice of
non magnetic particles or vacant sites. The current random field Ising system
displays mainly second order phase transitions, which, for some values of $p,
q$ and $h_{0}$, are followed by first order phase transitions joined smoothly
by a tricritical point; occasionally, two tricritical points appear implying
another second order phase transition. In addition to these points, re-entrant
phenomena can be seen for appropriate ranges of the temperature and random
field for specific values of $\lambda$, $p$ and $q$. Using the variational
principle, we write down the equilibrium equation for the magnetization and
solve it for both phase transitions and at the tricritical point in order to
determine the magnetization profile with respect to $h_{0}$, considered as an
independent variable in addition to the temperature.


title:
Pudding-mold type band in a potential thermoelectric material CuAlO$_2$
  : comparison with Na$_x$CoO$_2$

abstract:
  A potential thermoelectric material CuAlO$_2$ is theoretically studied. We
first construct a model Hamiltonian of CuAlO$_2$ based on the first principles
band calculation, and calculate the Seebeck coefficient. Then, we compare the
model with that of a well-known thermoelectric material Na$_x$CoO$_2$, and
discuss the similarities and the differences. It is found that the two
materials are similar from an electronic structure viewpoint in that they have
a peculiar pudding-mold type band shape, which is advantageous as
thermoelectric materials. There are however some differences, and we analyze
the origin of the difference from a microscopic viewpoint. The band shape of
CuAlO$_2$ is found to be even more ideal than that of Na$_x$CoO$_2$, and we
predict that once a significant amount of holes is doped in CuAlO$_2$,
thermoelectric properties (especially the power factor) even better than that
of Na$_x$CoO$_2$ can be expected.


title: Extreme spin squeezing for photons

abstract:
  We apply spin-squeezing techniques to identify and quantify highly
multi-partite photonic entanglement in polarization-squeezed light. We consider
a practical single-mode scenario, and find that Wineland-criterion polarization
squeezing implies entanglement of a macroscopic fraction of the total photons.
A Glauber-theory computation of the observable N-photon density matrix, with N
up to 100, finds that N-partite entanglement is observable despite losses and
without post-selection. We estimate that existing detectors could observe
$\sim1000$-partite entanglement from a few dB of polarization squeezing.


title:
Characterization of delay propagation in the US air transportation
  network

abstract:
  Complex networks provide a suitable framework to characterize air traffic.
Previous works described the world air transport network as a graph where
direct flights are edges and commercial airports are vertices. In this work, we
focus instead on the properties of flight delays in the US air transportation
network. We analyze flight performance data in 2010 and study the topological
structure of the network as well as the aircraft rotation. The properties of
flight delays, including the distribution of total delays, the dependence on
the day of the week and the hour-by-hour evolution within each day, are
characterized paying special attention to flights accumulating delays longer
than 12 hours. We find that the distributions are robust to changes in takeoff
or landing operations, different moments of the year or even different airports
in the contiguous states. However, airports in remote areas (Hawaii, Alaska,
Puerto Rico) can show peculiar distributions biased toward long delays.
Additionally, we show that long delayed flights have an important dependence on
the destination airport.


title: Solution of the Dicke model for N=3

abstract:
  The N=3 Dicke model couples three qubits to a single radiation mode via
dipole interaction and constitutes the simplest quantum-optical system allowing
for Greenberger-Horne-Zeilinger states. In contrast to the case N=1 (the Rabi
model), it is non-integrable if the counter-rotating terms are included. The
spectrum is determined analytically, employing the singularity structure of an
associated differential equation. While quasi-exact eigenstates known from the
Rabi model do not exist, a novel type of spectral degeneracy becomes possible
which is not associated with a symmetry of the system.

categories: quant-ph cond-mat.mes-hall math-ph math.MP


title: Absolute Magnitude Calibration for Red Clump Stars

abstract:
  We combined the ($K_s$, $J-K_s$) data in Laney et al. (2012) with the $V$
apparent magnitudes and trigonometric parallaxes taken from the Hipparcos
catalogue and used them to fit the $M_{K_s}$ absolute magnitude to a linear
polynomial in terms of $V-K_s$ colour. The mean and standard deviation of the
absolute magnitude residuals, -0.001 and 0.195 mag, respectively, estimated for
224 red clump stars in Laney et al. 2012 are (absolutely) smaller than the
corresponding ones estimated by the procedure which adopts a mean
$M_{K_s}=-1.613$ mag absolute magnitude for all red clump stars, -0.053 and
0.218 mag, respectively. The statistics estimated by applying the linear
equation to the data of 282 red clump stars in Alves (2000) are larger, $\Delta
M_{K_s}=0.209$ and $\sigma=0.524$ mag, which can be explained by a different
absolute magnitude trend, i.e. condensation along a horizontal distribution.


title:
Recursive marginal quantization of the Euler scheme of a diffusion
  process

abstract:
  We propose a new approach to quantize the marginals of the discrete Euler
diffusion process. The method is built recursively and involves the conditional
distribution of the marginals of the discrete Euler process. Analytically, the
method raises several questions like the analysis of the induced quadratic
quantization error between the marginals of the Euler process and the proposed
quantizations. We show in particular that at every discretization step $t\_k$
of the Euler scheme, this error is bounded by the cumulative quantization
errors induced by the Euler operator, from times $t\_0=0$ to time $t\_k$. For
numerics, we restrict our analysis to the one dimensional setting and show how
to compute the optimal grids using a Newton-Raphson algorithm. We then propose
a closed formula for the companion weights and the transition probabilities
associated to the proposed quantizations. This allows us to quantize in
particular diffusion processes in local volatility models by reducing
dramatically the computational complexity of the search of optimal quantizers
while increasing their computational precision with respect to the algorithms
commonly proposed in this framework. Numerical tests are carried out for the
Brownian motion and for the pricing of European options in a local volatility
model. A comparison with the Monte Carlo simulations shows that the proposed
method may sometimes be more efficient (w.r.t. both computational precision and
time complexity) than the Monte Carlo method.


title:
Proposal for a loophole-free violation of Bell inequalities with a set
  of single photons and homodyne measurements

abstract:
  We demonstrate that different kind of mesoscopic quantum states of light can
be efficiently generated from a simple iterative scheme using homodyne
heralding. These states exhibit strong non-classical features, and are of great
interest for many applications such as quantum error-correcting codes or
fundamental testings. On this basis we propose a protocol allowing a large
loophole-free violation of a CHSH-type Bell inequality with a remarkable
robustness to line losses.


title: Meson Spectrum in Strong Magnetic Fields

abstract:
  We study the relativistic quark-antiquark system embedded in magnetic field.
The Hamiltonian containing confinement, one gluon exchange and spin-spin
interaction is derived. We analytically follow the evolution of the lowest
meson states as a functions of MF strength. Calculating the one gluon exchange
interaction energy <V_OGE> and spin-spin contribution <a_SS> we have observed,
that these corrections remain finite at large magnetic fields, preventing the
vanishing of the total rho-meson mass at some B_crit, as previously thought. We
display the rho masses as functions of magnetic field in comparison with recent
lattice data.


title:
Noncommutative geometry on the universal envelopping algebra of the
  Borel subgroup U[sb(2)]

abstract:
  We study the Borel algebra de ne by [x a ; x b ] = 2 a;1 x b as a
noncommutative manifold R 3 . We calculate its noncommutative di erential form
relations. We deduce its partial derivative relations and the derivative of a
plane wave. After calculating its de Rham cohomology, we deduce the wave
operator and its corresponding magnetic solution.


title: Noncommutative geometry of the dihedral group D 6

abstract:
  We study the noncommutative geometry of the dihedral group D 6 using the
tools of quantum group theory. We explicit the torsion free regular spin
connection and the corresponding 'Levi-Civita' connection. Next, we nd the
Riemann curvature and its Ricci tensor. The main result is the Dirac operator
of a representation of the group which we nd the eigenvalues and the
eigenmodes.


title:
Noncommutative ricci curvature and dirac operator on B q [SU 2 ] at the
  fourth root of unity

abstract:
  We calculate the torsion free spin connection on the quantum group B q [SU 2
] at the fourth root of unity. From this we deduce the covariant derivative and
the Riemann curvature. Next we compute the Dirac operator of this quantum group
and we give numerical approximations of its eigenvalues.


title: Bornological modifications of hyperspace topologies

abstract:
  The bornological convergence structures that have been studied recently as
generalizations of Attouch-Wets convergence define pretopologies on
hyperspaces. In this paper we characterize the topological reflections of these
pretopologies and translate the constructions necessary to define bornological
convergence to a broader spectrum of hyperspace topologies.


title:
On Appropriate Selection of Fuzzy Aggregation Operators in Medical
  Decision Support System

abstract:
  The Decision Support System (DSS) contains more than one antecedent and the
degrees of strength of the antecedents need to be combined to determine the
overall strength of the rule consequent. The membership values of the
linguistic variables in Fuzzy have to be combined using an aggregation
operator. But it is not feasible to predefine the form of aggregation operators
in decision making. Instead, each rule should be found based on the feeling of
the experts and on their actual decision pattern over the set of typical
examples. Thus this work illustrates how the choice of aggregation operators is
intended to mimic human decision making and can be selected and adjusted to fit
empirical data, a series of test cases. Both parametrized and nonparametrized
aggregation operators are adapted to fit empirical data. Moreover, they
provided compensatory properties and, therefore, seemed to produce a better
decision support system. To solve the problem, a threshold point from the
output of the aggregation operators is chosen as the separation point between
two classes. The best achieved accuracy is chosen as the appropriate
aggregation operator. Thus a medical decision can be generated which is very
close to a practitioner's guideline.


title:
Generalisations of Integral Inequalities of Hermite-Hadamard type
  through Convexity

abstract:
  In this paper, we establish various inequalities for some differentiable
mappings that are linked with the illustrious Hermite-Hadamard integral
inequality for mappings whose derivatives are $s$-$(\alpha,m)$-convex.The
generalised integral inequalities contribute some better estimates than some
already presented. The inequalities are then applied to numerical integration
and some special means.


title:
Explicit formulas for parametrized families of irreducible algebraic
  Appell, Lauricella and Horn functions

abstract:
  For suitable choices of the parameters the Appell, Lauricella and Horn
functions are algebraic. In a previous paper we showed that there exist
families of algebraic functions for the F_4, F_C, G_3, H_4, H_5 and H_7
functions, depending on one parameter r. For each of these we give a solution
of the form f^r.g of the system of differential equations and give formulas for
f and g.


title:
Source attack of decoy-state quantum key distribution using phase
  information

abstract:
  Quantum key distribution (QKD) utilizes the laws of quantum mechanics to
achieve information-theoretically secure key generation. This field is now
approaching the stage of commercialization, but many practical QKD systems
still suffer from security loopholes due to imperfect devices. In fact,
practical attacks have successfully been demonstrated. Fortunately, most of
them only exploit detection-side loopholes which are now closed by the recent
idea of measurement-device-independent QKD. On the other hand, little attention
is paid to the source which may still leave QKD systems insecure. In this work,
we propose and demonstrate an attack that exploits a source-side loophole
existing in qubit-based QKD systems using a weak coherent state source and
decoy states. Specifically, by implementing a linear-optics
unambiguous-state-discrimination measurement, we show that the security of a
system without phase randomization --- which is a step assumed in conventional
security analyses but sometimes neglected in practice --- can be compromised.
We conclude that implementing phase randomization is essential to the security
of decoy-state QKD systems under current security analyses.


title: q \bar q-potential

abstract:
  We show how to define and compute in a non-perturbative way the potential
between q and \bar q colour sources in the singlet and octet (adjoint)
representation of the colour group.


title:
A New Distributed Evolutionary Computation Technique for Multi-Objective
  Optimization

abstract:
  Now-a-days, it is important to find out solutions of Multi-Objective
Optimization Problems (MOPs). Evolutionary Strategy helps to solve such real
world problems efficiently and quickly. But sequential Evolutionary Algorithms
(EAs) require an enormous computation power to solve such problems and it takes
much time to solve large problems. To enhance the performance for solving this
type of problems, this paper presents a new Distributed Novel Evolutionary
Strategy Algorithm (DNESA) for Multi-Objective Optimization. The proposed DNESA
applies the divide-and-conquer approach to decompose population into smaller
sub-population and involves multiple solutions in the form of cooperative
sub-populations. In DNESA, the server distributes the total computation load to
all associate clients and simulation results show that the time for solving
large problems is much less than sequential EAs. Also DNESA shows better
performance in convergence test when compared with other three well-known EAs.


title: On extensions for Ree groups of type F_4

abstract:
  Let k be an algebraically closed field of characteristic p=2. Let G=F_4 be
simply connected over k and let \sigma:G\to G be an endomorphism such that the
fixed point set G(\sigma) is a Ree group. We show, using the methods of
Bendel--Nakano--Pillen, that self-extensions of simple kG(\sigma)-modules
vanish generically and that for all but the first few Ree groups of type F_4,
the 1-cohomology for G(\sigma) with coefficients in simple kG-modules can be
identified with the 1-cohomology for G with coefficients in (possibly
different) simple G-modules.


title:
For Solving Linear Equations Recombination is a Needless Operation in
  Time-Variant Adaptive Hybrid Algorithms

abstract:
  Recently hybrid evolutionary computation (EC) techniques are successfully
implemented for solving large sets of linear equations. All the recently
developed hybrid evolutionary algorithms, for solving linear equations, contain
both the recombination and the mutation operations. In this paper, two modified
hybrid evolutionary algorithms contained time-variant adaptive evolutionary
technique are proposed for solving linear equations in which recombination
operation is absent. The effectiveness of the recombination operator has been
studied for the time-variant adaptive hybrid algorithms for solving large set
of linear equations. Several experiments have been carried out using both the
proposed modified hybrid evolutionary algorithms (in which the recombination
operation is absent) and corresponding existing hybrid algorithms (in which the
recombination operation is present) to solve large set of linear equations. It
is found that the number of generations required by the existing hybrid
algorithms (i.e. the Gauss-Seidel-SR based time variant adaptive (GSBTVA)
hybrid algorithm and the Jacobi-SR based time variant adaptive (JBTVA) hybrid
algorithm) and modified hybrid algorithms (i.e. the modified Gauss-Seidel-SR
based time variant adaptive (MGSBTVA) hybrid algorithm and the modified
Jacobi-SR based time variant adaptive (MJBTVA) hybrid algorithm) are
comparable. Also the proposed modified algorithms require less amount of
computational time in comparison to the corresponding existing hybrid
algorithms. As the proposed modified hybrid algorithms do not contain
recombination operation, so they require less computational effort, and also
they are more efficient, effective and easy to implement.


title:
Non-Fermi liquid correction to the neutrino mean free path and
  emissivity in neutron star beyond the leading order

abstract:
  In this work we have derived the expressions of the mean free path (MFP) and
emissivity of the neutrinos by incorporating non-Fermi liquid (NFL) corrections
upto next to leading order (NLO). We have shown how such corrections affect the
cooling of the neutron star composed of quark matter core.


title:
Constraints on the Galactic Dark Matter signal from the Fermi-LAT
  measurement of the diffuse gamma-ray emission

abstract:
  We study diffuse gamma-ray emission at intermediate Galactic latitudes
measured by the Fermi Large Area Telescope with the aim of searching for a
signal from dark matter annihilation or decay. In the absence of a robust dark
matter signal, constraints are presented. We set both, conservative dark matter
limits requiring that the dark matter signal does not exceed the observed
diffuse gamma-ray emission and limits derived based on modeling the foreground
astrophysical diffuse emission. Uncertainties in several parameters which
characterize conventional astrophysical emission are taken into account using a
profile likelihood formalism. The resulting limits impact the range of particle
masses over which dark matter thermal production in the early Universe is
possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray
anomalies as annihilation of dark matter.


title:
PIMC Simulations of Metal Hydrogen: Phase Transition and Equation of
  State

abstract:
  The article is devoted to numerical studies of atomic (metal) hydrogen with
Path Integral Monte Carlo (PIMC) technique. The research is focused on the
range of temperatures and densities where quantum statistics effects are
crucial for electrons and negligible for protons. In this range the equations
of state are obtained as a dependence of internal energy and pressure on
temperature and density. These dependences allow to detect and describe the
phase transition between solid and liquid phases.


title: Automorphisms of the plane preserving a curve

abstract:
  We study the group of automorphisms of the affine plane preserving some given
curve, over any field. The group is proven to be algebraic, except in the case
where the curve is a bunch of parallel lines. Moreover, a classification of the
groups of positive dimension occuring is also given in the case where the curve
is geometrically irreducible and the field is perfect.


title: FooPar: A Functional Object Oriented Parallel Framework in Scala

abstract:
  We present FooPar, an extension for highly efficient Parallel Computing in
the multi-paradigm programming language Scala. Scala offers concise and clean
syntax and integrates functional programming features. Our framework FooPar
combines these features with parallel computing techniques. FooPar is designed
modular and supports easy access to different communication backends for
distributed memory architectures as well as high performance math libraries. In
this article we use it to parallelize matrix matrix multiplication and show its
scalability by a isoefficiency analysis. In addition, results based on a
empirical analysis on two supercomputers are given. We achieve close-to-optimal
performance wrt. theoretical peak performance. Based on this result we conclude
that FooPar allows to fully access Scala's design features without suffering
from performance drops when compared to implementations purely based on C and
MPI.


title:
Computational aspects of gonal maps and radical parametrization of
  curves

abstract:
  We develop in this article an algorithm that, given a projective curve $C$,
computes a \textit{gonal map}, that is, a finite morphism from $C$ to the
projective line of minimal degree. Our method is based on the computation of
scrollar syzygies of canonical curves. We develop an improved version of our
algorithm for curves with a unique gonal map and we discuss a characterization
of such curves in terms of Betti numbers. Finally, we derive an efficient
algorithm for radical parametrization of curves of gonality $\le 4$.


title: Parabolic problems and interpolation with a function parameter

abstract:
  We give an application of interpolation with a function parameter to
parabolic differential operators. We introduce the refined anisotropic Sobolev
scale that consists of some Hilbert function spaces of generalized smoothness.
The latter is characterized by a real number and a function varying slowly at
infinity in Karamata's sense. This scale is connected with anisotropic Sobolev
spaces by means of interpolation with a function parameter. We investigate a
general initial--boundary value parabolic problem in the refined Sobolev scale.
We prove that the operator corresponding to this problem sets isomorphisms
between appropriate spaces pertaining to this scale.


title: Detecting extra-galactic supernova neutrinos in the Antarctic ice

abstract:
  Building on the technological success of the IceCube neutrino telescope, we
outline a prospective low-energy extension that utilizes the clear ice of the
South Pole. Aiming at a 10 Mton effective volume and a 10 MeV threshold, the
detector would provide sufficient sensitivity to detect neutrino bursts from
core-collapse supernovae (SNe) in nearby galaxies. The detector geometry and
required density of instrumentation are discussed along with the requirements
to control the various sources of background, such as solar neutrinos. In
particular, the suppression of spallation events induced by atmospheric muons
poses a challenge that will need to be addressed. Assuming this background can
be controlled, we find that the resulting detector will be able to detect SNe
from beyond 10 Mpc, delivering between 10 and 41 regular core-collapse SN
detections per decade. It would further allow to study more speculative
phenomena, such as optically dark (failed) SNe, where the collapse proceeds
directly to a black hole, at a detection rate similar to that of regular SNe.
We find that the biggest technological challenge lies in the required number of
large area photo-sensors, with simultaneous strict limits on the allowed noise
rates. If both can be realized, the detector concept we present will reach the
required sensitivity with a comparatively small construction effort and hence
offers a route to future routine observations of SNe with neutrinos.

categories: astro-ph.IM astro-ph.HE hep-ex physics.ins-det


title: Throughput Optimal Scheduling Policies in Networks of Interacting Queues

abstract:
  This report considers a fairly general model of constrained queuing networks
that allows us to represent both MMBP (Markov Modulated Bernoulli Processes)
arrivals and time-varying service constraints. We derive a set of sufficient
conditions for throughput optimality of scheduling policies that encompass and
generalize all the previously obtained results in the field. This leads to the
definition of new classes of (non diagonal) throughput optimal scheduling
policies. We prove the stability of queues by extending the traditional
Lyapunov drift criteria methodology.


title: Quantum critical scaling of fidelity in BCS-like model

abstract:
  We study scaling of the ground-state fidelity in neighborhoods of quantum
critical points in a model of interacting spinfull fermions - a BCS-like model.
Due to the exact diagonalizability of the model, in one and higher dimensions,
scaling of the ground-state fidelity can be analyzed numerically with great
accuracy, not only for small systems but also for macroscopic ones, together
with the crossover region between them. Additionally, in one-dimensional case
we have been able to derive a number of analytical formulae for fidelity and
show that they accurately fit our numerical results; these results are reported
in the article. Besides regular critical points and their neighborhoods, where
well-known scaling laws are obeyed, there is the multi-critical point and
critical points in its proximity where anomalous scaling behavior is found. We
consider also scaling of fidelity in neighborhoods of critical points where
fidelity oscillates strongly as the system size or the chemical potential is
varied. Our results for a one-dimensional version of a BCS-like model are
compared with those obtained by Rams and Damski in similar studies of a quantum
spin chain - an anisotropic XY model in transverse magnetic field.


title:
Diffraction Interference Induced Superfocusing in Nonlinear Talbot
  Effect

abstract:
  We report a simple, novel sub-diffraction method, i.e. diffraction
interference induced super-focusing in second-harmonic (SH) Talbot effect, to
achieve focusing size of less than {\lambda}_pump/8 without involving
evanescent waves or sub-wavelength apertures. By tailoring point spread
functions with Fresnel diffraction interference, we observe periodic SH
sub-diffracted spots over a hundred of micrometers away from the sample. Our
demonstration is the first experimental realization of the proposal by Toraldo
Di Francia pioneered 60 years ago for super-resolution imaging.


title: The H-index can be easily manipulated

abstract:
  We prove two complexity results about the H-index concerned with the Google
scholar merge operation on one's scientific articles. The results show that,
although it is hard to merge one's articles in an optimal way, it is easy to
merge them in such a way that one's H-index increases. This suggests the need
for an alternative scientific performance measure that is resistant to this
type of manipulation.


title:
On topological Clifford semigroups embeddable into products of cones
  over topological groups

abstract:
  In this paper we detect topological Clifford semigroups which are embeddable
into Tychonoff products of topological semilattices and cones over topological
groups. Also we detect topological Clifford semigroups which embed into compact
topological Clifford semigroups.


title: On the Hilbert space dimension of systems with second class constraints

abstract:
  It is shown that quantized dynamical system with second class constraints has
infinite dimensional Hilbert space.


title:
Discovery of a possibly single blue supergiant star in the intra-cluster
  region of Virgo cluster of galaxies

abstract:
  IC 3418 is a dwarf irregular galaxy falling into the Virgo cluster, and a 17
kpc long trail is seen behind the galaxy, which is considered to have formed
due to ram pressure stripping. The trail contains compact knots and diffuse
blobs of ultraviolet and blue optical emission and, thus, it is a clear site of
recent star formation but in an unusual environment, surrounded by a million
degree intra-cluster medium. We report on our optical spectroscopy of a compact
source in the trail, SDSS J122952.66+112227.8, and show that the optical
spectrum is dominated by emission from a massive blue supergiant star. If
confirmed, our report would mark the farthest star with spectroscopic
observation. We interpret that a massive O-type star formed in situ in the
trail has evolved recently out of the main sequence into this blue supergiant
phase, and now lacks any detectable spectral sign of its associated HII region.
We argue that turbulence within the ram pressure striped gaseous trail may play
a dominant role for the star formation within such trails.


title:
Kinematics and chemical properties of the Galactic stellar populations.
  The HARPS FGK dwarfs sample

abstract:
  (Abridged) We analyze chemical and kinematical properties of about 850 FGK
solar neighborhood long-lived dwarfs observed with the HARPS high-resolution
spectrograph. The stars in the sample have logg > 4 dex, 5000 < Teff < 6500 K,
and -1.39 < [Fe/H] < 0.55 dex. We apply a purely chemical analysis approach
based on the [alpha/Fe] vs. [Fe/H] plot to separate Galactic stellar
populations into the thin disk, thick disk and high-alpha metal-rich (hamr).
Our analysis shows a negative gradient of the rotational velocity of the thin
disk stars with [Fe/H] (-17 km s^-1 dex^-1), and a steep positive gradient for
both the thick disk and hamr stars with the same magnitude of about +42 km s^-1
dex^-1. For the thin disk stars we observed no correlation between orbital
eccentricities and metallicity, but observed a steep negative gradient for the
thick disk and hamr stars with practically the same magnitude (about -0.18
dex^-1). Our results suggest that radial migration played an important role in
the formation and evolution of the thin disk. For the thick disk stars it is
not possible to reach a firm conclusion about their origin. Based on the
eccentricity distribution of the thick disk stars only their accretion origin
can be ruled out, and the heating and migration scenario could explain the
positive steep gradient of V_phi with [Fe/H]. Analyzing the hamr stellar
population we found that they share properties of both the thin and thick disk
population. A comparison of the properties of the hamr stars with that of the
subsample of stars from the N-body/SPH simulation using radial migration
suggest that they may have originated from the inner Galaxy. Further detailed
investigations would help to clarify their exact nature and origin.


title: Weak Energy: Form and Function

abstract:
  The equation of motion for a time-independent weak value of a quantum
mechanical observable contains a complex valued energy factor - the weak energy
of evolution. This quantity is defined by the dynamics of the pre-selected and
post-selected states which specify the observable's weak value. It is shown
that this energy: (i) is manifested as dynamical and geometric phases that
govern the evolution of the weak value during the measurement process; (ii)
satisfies the Euler-Lagrange equations when expressed in terms of Pancharatnam
(P) phase and Fubini-Study (FS) metric distance; (iii) provides for a PFS
stationary action principle for quantum state evolution; (iv) time translates
correlation amplitudes; (v) generalizes the temporal persistence of state
normalization; and (vi) obeys a time-energy uncertainty relation. A similar
complex valued quantity - the pointed weak energy of an evolving state - is
also defined and several of its properties in PFS-coordinates are discussed. It
is shown that the imaginary part of the pointed weak energy governs the state's
survival probability and its real part is - to within a sign - the
Mukunda-Simon geometric phase for arbitrary evolutions or the Aharonov-Anandan
(AA) phase for cyclic evolutions. Pointed weak energy gauge transformations and
the PFS 1-form are discussed and the relationship between the PFS 1-form and
the AA connection 1-form is established.


title: Automorphisms of necklaces and sandpile groups

abstract:
  We introduce a group naturally acting on aperiodic necklaces of length $n$
with two colours using the 1--1 correspondences between aperiodic necklaces and
irreducible polynomials over the field $\F_2$ of two elements. We notice that
this group is isomorphic to the quotient group of non-degenerate circulant
matrices of size $n$ over that field modulo a natural cyclic subgroup. Our
groups turn out to be isomorphic to the sandpile groups for a special sequence
of directed graphs.


title: Graphene: QFT in curved spacetimes close to experiments

abstract:
  A recently proposed step-by-step procedure, to merge the low-energy physics
of the $\pi$-bonds electrons of graphene, and quantum field theory on curved
spacetimes, is recalled. The last step there is the proposal of an experiment
to test a Hawking-Unruh effect, emerging from the model, that manifests itself
as an exact (within the model) prediction for the electronic local density of
states, in the ideal case of the graphene membrane shaped as a Beltrami
pseudosphere. A discussion about one particular attempt to experimentally test
the model on molecular graphene is presented, and it is taken as an excuse to
solve some basic issues that will help future experiments. In particular, it is
stated that the effect should be visible on generic surfaces of constant
negative Gaussian curvature, that are infinite in number.


title:
Classification of 1-Weierstrass points on Kuribayashi quartics, II (with
  three parameters)

abstract:
  In this paper, we classify the 1-Weierstrass points of the Kuribayashi
quartic curves with three parameters $a,\,b$ and $c$ defined by the equation \[
C_{a,b,c}:x^{4}+y^{4}+z^{4}+ax^{2}y^{2}+bx^{2}z^2+cy^{2}z^{2}=0, \] such that
$(a^2-1)(b^2-1)(c^2-1)(a^2-4)(b^2-4)(c^2-4)(a^2+b^2+c^2-abc-4)\neq0.$
Furthermore, the geometry of these points is investigated.


title: String picture of 1+1 dimensional QED in light--front formulation

abstract:
  We study quantum electrodynamics in 1+1 dimensions in the light--front frame
using numerical methods. We analyze confinement and charge screening which are
key features of this system. By direct analysis of wavefunctions of bound
states in two parton sector we determine the string tension. In four parton
sector we introduce inclusive distributions and inspect structure of energy
eigenstates. We conclude that they are composed of two weakly interacting
$f\bar f$ pairs. These four particle states are responsible for the screening.
Finally, we study time evolution of a fermion--antifermion state separated by a
specific distance. We demonstrate that for sufficient separation it decays into
a multiparton state and the number of particles in the product depends on
separation of particles.


title:
Discrepancies in the Monte Carlo simulations of propagation of
  ultra-high energy cosmic-ray photons in the geomagnetic field

abstract:
  The discrepancies in the results produced by the two most commonly used Monte
Carlo programs for simulation of propagation of ultra-high energy cosmic ray
photons in the presence of the geomagnetic field are presented. Although
photons have not yet been discovered in the cosmic ray flux at highest
energies, the capabilities of the present cosmic ray detectors make their
discovery possible, according to the predictions of conventional models, within
the next few years. It is therefore necessary to have a reliable and well
maintained software for relevant simulations. The results of this paper are
important for simulations of propagation of photons at energies above 10^19 eV.
Photons of such high energies might interact with the geomagnetic field giving
rise to a cascade of particles even above the atmosphere. This effect is called
a "preshower effect". The preshower effect is important for air shower
evolution and has to be accounted for in full Monte Carlo simulations of
propagation of highest energy cosmic-ray photons. In this paper we compare the
two most frequently used Monte Carlo codes for preshower simulations:
PRESHOWER, used as a stand-alone program or as a part of CORSIKA, and MaGICS,
used as a part of AIRES.


title: Systems of the Kowalevski type and discriminantly separable polynomials

abstract:
  Starting from the notion of discriminantly separable polynomials of degree
two in each of three variables, we construct a class of integrable dynamical
systems. These systems can be integrated explicitly in genus two
theta-functions in a procedure which is similar to the classical one for the
Kowalevski top. The discriminnatly separable polynomials play the role of the
Kowalevski fundamental equation. The natural examples include the Sokolov
systems and the Jurdjevic elasticae.


title: Cooper pair transfer in nuclei

abstract:
  The second order DWBA implementation of two-particle transfer direct
reactions which includes simultaneous and successive transfer, properly
corrected by non-orthogonality effects is tested with the help of controlled
nuclear structure and reaction inputs against data spanning the whole mass
table, and showed to constitute a quantitative probe of nuclear pairing
correlations.


title: The elusive origin of Carbon-Enhanced Metal-Poor stars

abstract:
  Carbon-enhanced metal-poor (CEMP) stars count for 9-25% of all the very
metal-poor stars of the halo. In at least some CEMP stars the chemical
enrichment is believed to be due to wind mass transfer in the past from an AGB
donor star on to a low-mass companion. However, binary population synthesis
models predict much lower CEMP fractions. As an alternative to the canonical
Bondi-Hoyle-Lyttleton (BHL) wind accretion model, recent hydrodynamical
simulations suggest an efficient mode of wind mass transfer, called wind
Roche-lobe overflow (WRLOF), can reproduce observations of AGB winds in binary
systems. We use our population synthesis model to test the consequences of
WRLOF on a population of CEMP stars. Compared to previous predictions based on
the BHL model we find a modest increase of the fraction of CEMP stars and
substantial differences in the distributions of carbon and periods in the
population of CEMP stars.


title:
Sign-changing stationary solutions and blowup for the nonlinear heat
  equation in dimension two

abstract:
  Consider the nonlinear heat equation v_t-\Delta v=|v|^{p-1}v in the unit ball
of R^2, with Dirichlet boundary condition. Let u_{p,K} be a radially symmetric,
sign-changing stationary solution having a fixed number K of nodal regions. We
prove that the solution of the equation with initial value \lambda u_{p,K}
blows up in finite time if |\lambda-1|>0 is sufficiently small and if p is
sufficiently large. The proof is based on the analysis of the asymptotic
behavior of $u_{p,K}$ and of the linearized operator L= -\Delta - p
|u_{p,K}|^{p-1}. To show this we consider the linearized operator L= -\Delta -
p|u_p|^{p-1} and study the behavior of its first eigenvalue and of its first
normalized eigenfunction for large p.


title: Branching random tessellations with interaction: A thermodynamic view

abstract:
  A branching random tessellation (BRT) is a stochastic process that transforms
a coarse initial tessellation of $\mathbb{R}^d$ into a finer tessellation by
means of random cell divisions in continuous time. This concept generalises the
so-called STIT tessellations, for which all cells split up independently of
each other. Here, we allow the cells to interact, in that the division rule for
each cell may depend on the structure of the surrounding tessellation.
Moreover, we consider coloured tessellations, for which each cell is marked
with an internal property, called its colour. Under a suitable condition, the
cell interaction of a BRT can be specified by a measure kernel, the so-called
division kernel, that determines the division rules of all cells and gives rise
to a Gibbsian characterisation of BRTs. For translation invariant BRTs, we
introduce an "inner" entropy density relative to a STIT tessellation. Together
with an inner energy density for a given "moderate" division kernel, this leads
to a variational principle for BRTs with this prescribed kernel, and further to
an existence result for such BRTs.


title: Positivity of Thom polynomials and Schubert calculus

abstract:
  We describe the positivity of Thom polynomials of singularities of maps,
Lagrangian Thom polynomials and Legendrian Thom polynomials. We show that these
positivities come from Schubert calculus.


title:
An Analysis on the Inter-Cell Station Dependency Probability in an IEEE
  802.11 Infrastructure WLANs

abstract:
  In this document, we are primarily interested in computing the probabilities
of various types of dependencies that can occur in a multi-cell infrastructure
network.


title: Integral operators on analytic Morrey spaces

abstract:
  In this note, we study the boundedness of integral operators $I_{g}$ and
$T_{g}$ on analytic Morrey spaces. Furthermore, the norm and essential norm of
those operators are given.


title:
Shortest Path and Distance Queries on Road Networks: Towards Bridging
  Theory and Practice

abstract:
  Given two locations $s$ and $t$ in a road network, a distance query returns
the minimum network distance from $s$ to $t$, while a shortest path query
computes the actual route that achieves the minimum distance. These two types
of queries find important applications in practice, and a plethora of solutions
have been proposed in past few decades. The existing solutions, however, are
optimized for either practical or asymptotic performance, but not both. In
particular, the techniques with enhanced practical efficiency are mostly
heuristic-based, and they offer unattractive worst-case guarantees in terms of
space and time. On the other hand, the methods that are worst-case efficient
often entail prohibitive preprocessing or space overheads, which render them
inapplicable for the large road networks (with millions of nodes) commonly used
in modern map applications.
  This paper presents {\em Arterial Hierarchy (AH)}, an index structure that
narrows the gap between theory and practice in answering shortest path and
distance queries on road networks. On the theoretical side, we show that, under
a realistic assumption, AH answers any distance query in $\tilde{O}(\log \r)$
time, where $\r = d_{max}/d_{min}$, and $d_{max}$ (resp.\ $d_{min}$) is the
largest (resp.\ smallest) $L_\infty$ distance between any two nodes in the road
network. In addition, any shortest path query can be answered in $\tilde{O}(k +
\log \r)$ time, where $k$ is the number of nodes on the shortest path. On the
practical side, we experimentally evaluate AH on a large set of real road
networks with up to twenty million nodes, and we demonstrate that (i) AH
outperforms the state of the art in terms of query time, and (ii) its space and
pre-computation overheads are moderate.


title:
On the Cauchy problem for a generalized Camassa-Holm equation with both
  quadratic and cubic nonlinearity

abstract:
  In this paper, we study the Cauchy problem for a generalized integrable
Camassa-Holm equation with both quadratic and cubic nonlinearity. By overcoming
the difficulties caused by the complicated mixed nonlinear structure, we
firstly establish the local well-posedness result in Besov spaces, and then
present a precise blow-up scenario for strong solutions. Furthermore, we show
the existence of single peakon by the method of analysis.


title:
First-order phase transition and anomalous hysteresis of Bose gases in
  optical lattices

abstract:
  We study the first-order quantum phase transitions of Bose gases in optical
lattices. A special emphasis is placed on an anomalous hysteresis behavior, in
which the phase transition occurs in a unidirectional way and a hysteresis loop
does not form. We first revisit the hardcore Bose-Hubbard model with
dipole-dipole interactions on a triangular lattice to analyze accurately the
ground-state phase diagram and the hysteresis using the cluster mean-field
theory combined with cluster-size scaling. Details of the anomalous hysteresis
are presented. We next consider the two-component and spin-1 Bose-Hubbard
models on a hypercubic lattice and show that the anomalous hysteresis can
emerge in these systems as well. In particular, for the former model, we
discuss the experimental feasibility of the first-order transitions and the
associated hysteresis. We also explain an underlying mechanism of the anomalous
hysteresis by means of the Ginzburg-Landau theory. From the given cases, we
conclude that the anomalous hysteresis is a ubiquitous phenomenon of systems
with a phase region of lobe shape that is surrounded by the first-order
boundary.


title:
The hierarchy of higher order solutions of the derivative nonlinear
  Schr\"odinger equation

abstract:
  In this paper, we provide a simple method to generate higher order position
solutions and rogue wave solutions for the derivative nonlinear Schr\"odinger
equation. The formulae of these higher order solutions are given in terms of
determinants. The dynamics and structures of solutions generated by this method
are studied.


title: Active Consensus over Sensor Networks via Randomized Communication

abstract:
  Distributed consensus has been widely studied for sensor network
applications. Whereas the asymptotic convergence rate has been extensively
explored in prior work, other important and practical issues, including energy
efficiency and link reliability, have received relatively little attention. In
this paper, we present a distributed consensus approach that can achieve a good
balance between convergence rate and energy efficiency.
  The approach selects a subset of links that significantly contribute to the
formation of consensus at each iteration, thus adapting the network's topology
dynamically to the changes of the sensor states. A global optimization problem
is formulated for optimal link selection, which is subsequently factorized into
sub-problems that can be solved locally, and practically via approximation. An
algorithm is derived to solve the approximation efficiently, using quadratic
programming (QP) relaxation and random sampling. Simulations on networks of
different types demonstrate that the proposed method reduces the communication
energy costs without significantly impacting the convergence rate and that the
approach is robust to link failures.


title: Stability and performance of stochastic predictive control

abstract:
  This article is concerned with stability and performance of controlled
stochastic processes under receding horizon policies. We carry out a systematic
study of methods to guarantee stability under receding horizon policies via
appropriate selections of cost functions in the underlying finite-horizon
optimal control problem. We also obtain quantitative bounds on the performance
of the system under receding horizon policies as measured by the long-run
expected average cost. The results are illustrated with the help of several
simple examples.


title:
Particle flows in a dc discharge in laboratory and microgravity
  conditions

abstract:
  We describe a series of experiments on dust particles flows in a positive
column of a horizontal dc discharge operating in laboratory and microgravity
conditions. The main observation is that the particle flow velocities in
laboratory experiments are systematically higher than in microgravity
experiments, for otherwise identical discharge conditions. The paper provides
an explanation for this interesting and unexpected observation. The explanation
is based on a physical model, which properly takes into account main
plasma-particle interaction mechanisms relevant to the described experimental
study. Comparison of experimentally measured particle velocities and those
calculated using the proposed model demonstrates reasonable agreement, both in
laboratory and microgravity conditions, in the entire range of discharge
parameters investigated.


title: The higher order Rogue Wave solutions of the Gerdjikov-Ivanov equation

abstract:
  We construct higher order rogue wave solutions for the Gerdjikov-Ivanov
equation explicitly in term of determinant expression. Dynamics of both soliton
and non-soliton solutions is discussed. A family of solutions with distinct
structures are presented, which are new to the Gerdjikov-Ivanov equation.


title:
Transverse Single Spin Asymmetry in $e+p^\uparrow \to e+J/\psi +X $ and
  Transverse Momentum Dependent Evolution of the Sivers Function

abstract:
  We extend our analysis of transverse single spin asymmetry (SSA) in
electroproduction of $J/\psi$ to include the effect of the scale evolution of
the transverse momentum dependent (TMD) parton distribution functions and gluon
Sivers function. We estimate SSA for JLab, HERMES, COMPASS, and eRHIC energies
using the color evaporation model of charmonium production, using an
analytically obtained approximate solution of TMD evolution equations discussed
in the literature. We find that there is a reduction in the asymmetry compared
with our predictions for the earlier case considered by us, wherein the $Q^2$
dependence came only from DGLAP evolution of the unpolarized gluon densities
and a different parametrization of the TMD Sivers function was used.


title: Spherical Harmonics

abstract:
  This is Chapter 1 of the book {\it Approximation Theory and Harmonic Analysis
on Spheres and Balls} by the authors. It provides a self-contained introduction
to spherical harmonics. The book will be published as a title in {\it Springer
Monographs in Mathematics} by Springer in 2013. The table of contents of the
book is attached at the end of this file.


title: The International Linear Collider

abstract:
  We present a brief summary of the International Linear Collider as documented
in the 2013 Technical Design Report. The Technical Design Report has detailed
descriptions of the accelerator baseline design for a 500 GeV e+e- linear
collider, the R&D program that has demonstrated its feasibility, the physics
goals and expected sensitivities, and the description of the ILD and SiD
detectors and their capabilities.


title:
Dynamo effects in magnetorotational turbulence with finite thermal
  diffusivity

abstract:
  We investigate the saturation level of hydromagnetic turbulence driven by the
magnetorotational instability in the case of vanishing net flux. Motivated by a
recent paper of Bodo, Cattaneo, Mignone, & Rossi, we here focus on the case of
a non-isothermal equation of state with constant thermal diffusivity. The
central aim of the paper is to complement the previous result with closure
parameters for mean-field dynamo models, and to test the hypothesis that the
dynamo is affected by the mode of heat transport. We perform computer
simulations of local shearing-box models of stratified accretion disks with
approximate treatment of radiative heat transport, which is modeled via thermal
conduction. We study the effect of varying the (constant) thermal diffusivity,
and apply different vertical boundary conditions. In the case of impenetrable
vertical boundaries, we confirm the transition from mainly conductive to mainly
convective vertical heat transport below a critical thermal diffusivity. This
transition is however much less dramatic when more natural outflow boundary
conditions are applied. Similarly, the enhancement of magnetic activity in this
case is less pronounced. Nevertheless, heating via turbulent dissipation
determines the thermodynamic structure of accretion disks, and clearly affects
the properties of the related dynamo. This effect may however have been
overestimated in previous work, and a careful study of the role played by
boundaries will be required.


title:
Spectrally determined singularities in a potential with an inverse
  square initial term

abstract:
  We study the inverse spectral problem for Bessel type operators with
potential (v(x)): (H_\kappa=-\partial_x^2+\frac{k}{x^2}+v(x)). The potential is
assumed smooth in ((0,R)) and with an asymptotic expansion in powers and
logarithms as (x\rightarrow 0^+, v(x)=O(x^\alpha), \alpha >-2). Specifically we
show that the coefficients of the asymptotic expansion of the potential are
spectrally determined. This is achieved by computing the expansion of the trace
of the resolvent of this operator which is spectrally determined and
elaborating the relation of the expansion of the resolvent with that of the
potential, through the singular asymptotics lemma.


title: High-statistics measurement of the beta-delayed alpha spectrum of 20Na

abstract:
  A measurement of the 20Na beta-delayed alpha spectrum with a high-granularity
set-up has allowed the decay scheme to be revised on several points. Three new
transitions of low intensity are found at low alpha-particle energy. An
R-matrix fit of the complete spectrum gives an improved description of the
decay and indicates feeding to the broad 2^+ alpha-cluster state close to 9
MeV.


title: Some open problems

abstract:
  We discuss some challenging open problems in the geometric control theory and
sub-Riemannian geometry.


title:
Limits on neutral Higgs boson production in the forward region in $pp$
  collisions at $\sqrt{s} = 7$ TeV

abstract:
  Limits on the cross-section times branching fraction for neutral Higgs
bosons, produced in $pp$ collisions at $\sqrt{s} = 7$ TeV, and decaying to two
tau leptons with pseudorapidities between 2.0 and 4.5, are presented. The
result is based on a dataset, corresponding to an integrated luminosity of 1.0
$\mathrm{fb}^{-1}$, collected with the LHCb detector. Candidates are identified
by reconstructing final states with two muons, a muon and an electron, a muon
and a hadron, or an electron and a hadron. A model independent upper limit at
the 95% confidence level is set on a neutral Higgs boson cross-section times
branching fraction. It varies from 8.6 pb for a Higgs boson mass of 90 GeV to
0.7 pb for a Higgs boson mass of 250 GeV, and is compared to the Standard Model
expectation. An upper limit on $\tan\beta$ in the Minimal Supersymmetric Model
is set in the $m_{h^0}^\mathrm{max}$ scenario. It ranges from 34 for a CP-odd
Higgs boson mass of 90 GeV to 70 for a pseudo-scalar Higgs boson mass of 140
GeV.


title: Testing the regularity of a smooth signal

abstract:
  We develop a test to determine whether a function lying in a fixed
$L_2$-Sobolev-type ball of smoothness $t$, and generating a noisy signal, is in
fact of a given smoothness $s\geq t$ or not. While it is impossible to
construct a uniformly consistent test for this problem on every function of
smoothness $t$, it becomes possible if we remove a sufficiently large region of
the set of functions of smoothness $t$. The functions that we remove are
functions of smoothness strictly smaller than $s$, but that are very close to
$s$-smooth functions. A lower bound on the size of this region has been proved
to be of order $n^{-t/(2t+1/2)}$, and in this paper, we provide a test that is
consistent after the removal of a region of such a size. Even though the null
hypothesis is composite, the size of the region we remove does not depend on
the complexity of the null hypothesis.


title:
The Effect of Covariance Estimator Error on Cosmological Parameter
  Constraints

abstract:
  Extracting parameter constraints from cosmological observations requires
accurate determination of the covariance matrix for use in the likelihood
function. We show here that uncertainties in the elements of the covariance
matrix propagate directly to increased uncertainties in cosmological
parameters. When the covariance matrix is determined by simulations, the
resulting variance of the each parameter increases by a factor of order
$1+N_b/N_s$ where $N_b$ is the number of bands in the measurement and $N_s$ is
the number of simulations.


title:
QCD effective charge from the three-gluon vertex of the background-field
  method

abstract:
  In this article we study in detail the prospects of determining the infrared
finite QCD effective charge from a special kinematic limit of the vertex
function corresponding to three background gluons. This particular Green's
function satisfies a QED-like Ward identity, relating it to the gluon
propagator, with no reference to the ghost sector. Consequently, its
longitudinal form factors may be expressed entirely in terms of the
corresponding gluon wave function, whose inverse is proportional to the
effective charge. After reviewing certain important theoretical properties, we
consider a typical lattice quantity involving this vertex, and derive its exact
dependence on the various form factors, for arbitrary momenta. We then focus on
the particular momentum configuration that eliminates any dependence on the
(unknown) transverse form factors, projecting out only the desired quantity. A
preliminary numerical analysis indicates that the effective charge is
relatively insensitive to the numerical uncertainties that may afflict future
simulations of the aforementioned lattice quantity. The numerical difficulties
associated with a parallel determination of the dynamical gluon mass are
briefly discussed.


title: Defects dynamics following thermal quenches in square spin-ice

abstract:
  We present a study of the single spin flip stochastic dynamics of the two
dimensional sixteen vertex model. We single out several dynamic regimes
controlled by different processes that we describe. We analyse the emergence of
very long-lived metastable states and their dependence on the system size,
boundary conditions, and working parameters. We investigate the coarsening
process after quenches into the ordered ferromagnetic and antiferromagnetic
phases. We discuss our results in the context of artificial spin ice on square
lattices.


title:
c-a-ca Mean Field RVB Model of CuNCN Physics. Structure Manifestations
  of the RVB Transitions

abstract:
  We propose a new form of the frustrated Heisenberg antiferromagnetic
Hamiltonian with spatially anisotropic exchange parameters Jc, Ja, and Jac
extended along the c, a, and a +/- c lattice directions and apply it to
describe fascinating physics of copper carbodiimide CuNCN in the assumption of
resonating valence bond (RVB) type of its phases. These are invoked to explain
the intriguing absence of magnetic order in CuNCN down to 4 K. We show that the
quasiparticle spectrum of the RVB model of the proposed Hamiltonian has three
principal regimes: (i) one with two pairs of lines of nodes, (ii) one with a
pair of lines of nodes (termed as 1D- and Q1D-RVB states), (iii) and one with
two pseudogaps and four nodal points (2D-RVB). We present a complete
parameters-temperature phase diagram of the model constructed with use of the
high-temperature expansion of the free energy. The phase diagram thus obtained
contains eight different phases whose magnetic behavior includes Curie and
Pauli paramagnetism (respectively, in disordered and 1D- or Q1D-RVB phases),
and gapped (quasi-Arrhenius) paramagnetism (2D-RVB phases). Adding
magnetostriction and elastic terms to the free energy we derive possible
structural manifestations of transitions between RVB phases. Assuming a
sequence of transitions between RVB phases to occur in CuNCN while temperature
decreases explains the features observed in the temperature runs of the
magnetic susceptibility and lattice constants. Confronting these with the
magnetic susceptibility and structure data measured as functions of temperature
in the range between ca. 20 and 200 K we show a remarkably good agreement
between our theoretical predictions and the experiment as reached by ascribing
the model parameters values which are intuitively acceptable both in terms of
their absolute and relative magnitudes and of the character of their geometry
dependence.


title: Maximal finite subgroups and minimal classes

abstract:
  We apply Voronoi's algorithm to compute representatives of the conjugacy
classes of maximal finite subgroups of the unit group of a maximal order in
some simple $\QQ $-algebra. This may be used to show in small cases that
non-conjugate orders have non-isomorphic unit groups.


title: Galactic Dark Matter and Bertrand Space-times

abstract:
  Bertrand space-times (BSTs) are static, spherically symmetric solutions of
Einstein's equations, that admit stable, closed orbits. Starting from the fact
that to a good approximation, stars in the disc or halo regions of typical
galaxies move in such orbits, we propose that, under certain physical
assumptions, the dark matter distribution of some low surface brightness (LSB)
galaxies can seed a particular class of BSTs. In the Newtonian limit, it is
shown that for flat rotation curves, our proposal leads to an analytic
prediction of the NFW dark matter profile. We further show that the dark matter
distribution that seeds the BST, is described by a two-fluid anisotropic model,
and present its analytic solution. A new solution of the Einstein's equations,
with an internal BST and an external Schwarzschild metric, is also constructed.


title: Comment on "Time reversal polarization and a Z2 adiabatic spin pump"

abstract:
  In Ref 1[Phy. Rev. B 74, 195312(2006)] Fu and Kane propose a spin pump for
onedimensional (1D) insulating Hamiltonians. They claim that this spin pump is
a Z2 pump because For an isolated system, a single closed cycle of the pump
changes the expectation value of the spin at each end even when spin-orbit
interactions violate the conservation of spin. A second cycle, however, returns
the system to its original state. A Z2 topological invariant is proposed to
characterize the Z2 pump. In this comment we show their discussion on the spin
pump is inaccurate. Their reason why the isolated system return to its original
state after second cycle is unjustified and several claims contradict to this
return of the system are made in Ref 1. Detailed calculations and concrete
examples show the degeneracy of the first excited state at t = 0, T; is not
split by the electron-electron interaction in the way described in Ref 1 and
there is level crossing at t = T. In fact, despite of a detailed search, not a
single system behave as described in Fig. 1(d) in Ref 1 has been found. Thus we
conclude the isolated system won't return to its original state after two
cycles and the spin pump is not a Z2 pump in general.


title:
Measurement of CP violation and the B_s^0 meson decay width difference
  with B_s^0\to J/\psi K^+ K^- and B_s^0\to J/\psi\pi^+\pi^- decays

abstract:
  The time-dependent CP asymmetry in B_s^0\to J/\psi K^+K^- decays is measured
using $pp$ collision data at \sqrt{s}=7TeV, corresponding to an integrated
luminosity of 1.0fb^-1, collected with the LHCb detector. The decay time
distribution is characterised by the decay widths \Gamma_L and \Gamma_H of the
light and heavy mass eigenstates of the B_s^0--\bar{B}_s^0 system and by a
CP-violating phase \phi_s. In a sample of 27\,617 B_s^0\to J/\psi K^+K^-
decays, where the dominant contribution comes from B_s^0\to J/\psi\phi\ decays,
these parameters are measured to be
  \phi_s = 0.07 \pm 0.09 (stat) \pm 0.01 (syst) rad,
  \Gamma_s \equiv (\Gamma_L+\Gamma_H)/2 = 0.663 \pm 0.005 (stat) \pm 0.006
(syst) ps^-1,
  \Delta\Gamma_s \equiv \Gamma_L -\Gamma_H = 0.100 \pm 0.016 (stat) \pm 0.003
(syst) & ps^-1, corresponding to the single most precise determination of
\phi_s, \Delta\Gamma_s and \Gamma_s. The result of performing a combined
analysis with B_s^{0} \to J/\psi \pi^+\pi^- decays gives
  \phi_s = 0.01 \pm 0.07 (stat) \pm 0.01 (syst) rad,
  \Gamma_s = 0.661 \pm 0.004 (stat) \pm 0.006 (syst) ps^-1,
  \Delta\Gamma_s = 0.106 \pm 0.011 (stat) \pm 0.007 (syst) & ps^-1.
  All measurements are in agreement with the Standard Model predictions.


title:
$[{\bf 70, \ell^+}]$ baryons in large $N_c$ QCD revisited: The effect on
  Regge trajectories

abstract:
  A simple procedure within the $1/N_c$ expansion method where all the $N_c$
quarks are treated on the same footing has been found successful in describing
mixed symmetric negative parity baryon states belonging to the $[{\bf
70},\ell^-]$ multiplets %with $\ell$ = 1, 2 or 3. of the $N$ = 1 and 3 bands.
Presently it is applied to mixed symmetric positive parity $[{\bf 70},0^+]$ and
$[{\bf 70},2^+]$ multiplets of the $N$ = 2 band. We search for the most
dominant terms in the mass formula. The results are compared to those obtained
in the procedure where the system is separated into a core and an excited
quark. We find that both the spin and isospin operators of the entire system of
$N_c$ quarks play dominant roles in describing the data, like for negative
parity states. As a by-product we present the contribution of the leading
spin-isospin singlet term as a function of the band number, which hints at
distinct Regge trajectories for the symmetric and mixed symmetric states.


title:
Half-metallicity and anisotropy magnetoresistance properties of Heusler
  alloys Fe2Co1-xCrxSi

abstract:
  In this paper, we investigate the half-metallicity of Heusler alloys
Fe2Co1-xCrxSi by first principles calculations and anisotropy magnetoresistance
measurements. It is found that, with the increase of Cr content x, the Fermi
level of Fe2Co1-xCrxSi moves from the top of valence band to the bottom of
conduction band, and a large half-metallic band gap of 0.75 eV is obtained for
x=0.75. We then successfully synthesized a series Heusler Fe2Co1-xCrxSi
polycrystalline ribbon samples. The results of X-ray diffraction indicate that
the Fe2Co1-xCrxSi series of samples are pure phase with a high degree of order
and the saturation magnetic moment follows half-metallic Slater-Pauling rule.
Except for the two end members, Fe2CoSi and Fe2CrSi, the anisotropic
magnetoresistance of Fe2Co1-xCrxSi (x=0.25, 0.5, 0.75) show a negative value
suggesting they are stable half-metallic ferromagnets.


title:
Exchange randomness and spin dynamics in the frustrated magnetic
  Keplerate {W72V30}

abstract:
  The magnetic properties and spin dynamics of the spin frustrated
polyoxometalate {W72V30}, where 30 V^{4+} ions (s = 1/2) occupy the sites of an
icosidodecahedron, have been investigated by low temperature magnetization,
magnetic susceptibility, proton and vanadium nuclear magnetic resonance, and
theoretical studies. The field-dependent magnetization at 0.5 K increases
monotonically up to 50 T without any sign of staircase behavior. This
low-temperature behavior cannot be explained by a Heisenberg model based on a
single value of the nearest-neighbor exchange coupling. We analyze this
behavior upon assuming a rather broad distribution of nearest-neighbor exchange
interactions. Slow spin dynamics of {W72V30} at low temperatures is observed
from the magnetic field and temperature dependence of nuclear spin-lattice
relaxation rate 1/T_1 measurements.


title: On the predictability of the number of convex vertices

abstract:
  Convex hulls are a fundamental geometric tool used in a number of algorithms.
As a side-effect of exhaustive tests for an algorithm for which a convex hull
computation was the first step, interesting experimental results were found and
are the sunject of this paper. They establish that the number of convex
vertices of natural datasets can be predicted, if not precisely at least within
a defined range. Namely it was found that the number of convex vertices of a
dataset of N points lies in the range 2.35 N^0.091 <= h <= 19.19 N^0.091. This
range obviously does not describe neither natural nor artificial worst-cases
but corresponds to the distributions of natural data. This can be used for
instance to define a starting size for pre-allocated arrays or to evaluate
output-sensitive algorithms. A further consequence of these results is that the
random models of data used to test convex hull algorithms should be bounded by
rectangles and not as they usually are by circles if they want to represent
accurately natural datasets


title:
Stokes imaging of AM Her systems using 3D inhomogeneous models-II.
  Modelling X-ray and optical data of CP Tucanae

abstract:
  The viewing geometry of the polar CP Tuc that better explains its optical and
X-ray light curves is controversial. Previous modelling of white-light
polarimetric data considered the partial self-eclipse of an extended
inhomogeneous emitting region. Alternatively, phase-dependent absorption has
been used to reproduce the X-ray data. This paper presents new optical
polarimetric data of CP Tuc and a model that consistently explains its optical
and X-ray data. The model was based on an extension of the CYCLOPS code that
added X-ray bremsstrahlung emission and pre-shock region absorption to the
original version, which only accounted for cyclotron emission. The new code
creates the possibility of simultaneous optical and X-ray fitting. We show that
self-eclipse and absorption data have distinct signatures on the X-ray spectra.
Although we were able to reasonably fit the CP Tuc optical data to cases of
absorption and self-eclipse, we were only able to reproduce the X-ray orbital
modulation after considering the absorption in the pre-shock region.
Specifically, we were unable to reproduce the X-ray observations in the
self-eclipse case. We found that the primary emitting region in CP Tuc is
located near the rotation pole that approximately points to the observer.


title: Introduction to sutured Floer homology

abstract:
  This article is a standalone introduction to sutured Floer homology for
graduate students in geometry and topology. It is divided into three parts. The
first part is an introductory level exposition of Lagrangian Floer homology.
The second part is a construction of Heegaard Floer homology as a special, and
slightly modified, case of Lagrangian Floer homology. The third part covers the
background on sutured manifolds, the definition of sutured Floer homology, as
well as a discussion of its most basic properties and implications (it detects
the product, behaves nicely under surface decompositions, defines an asymmetric
polytope, its Euler characteristic is computable using Fox calculus).