title: Oscillating universe with quintom matter

abstract:
  In this paper, we study the possibility of building a model of the
oscillating universe with quintom matter in the framework of 4-dimensional
Friedmann-Robertson-Walker background. Taking the two-scalar-field quintom
model as an example, we find in the model parameter space there are five
different types of solutions which correspond to: (I) a cyclic universe with
the minimal and maximal values of the scale factor remaining the same in every
cycle, (II) an oscillating universe with its minimal and maximal values of the
scale factor increasing cycle by cycle, (III) an oscillating universe with its
minimal and maximal values of the scale factor decreasing cycle by cycle, (IV)
an oscillating universe with its scale factor always increasing, and (V) an
oscillating universe with its scale factor always decreasing.


title: Hyper-accreting tori of Gamma Ray Bursters

abstract:
  We present numerical simulations of axisymmetric magnetised massive tori
around rotating black holes taking into account the energy losses due to
emission of neutrinos. A realistic equation of state is used which takes into
account the energy losses due to dissociation of nuclei. The heating due to
neutrino-antineutrino annihilation is not included. We study the cases of
optically thick, semi-transparent, and optically thin to neutrino discs. We
show that neutrino cooling does not change significantly the structure of
accretion flow and the total energy release. The time scale of accretion is set
by the torus angular momentum. Due to the lack of magnetic dynamo in our
calculations, it is the initial strength of magnetic field and its topology
that determine the process of jet formation and its energetics. Extrapolation
of our results gives the total energy released in the jet $\sim 10^{52}$ erg.
This is sufficient to explain the hypernovae explosions associated with GRB
980425 and GRB 030329.


title: Some conjectures about q-Fibonacci polynomials

abstract:
  In this paper we state some conjectures about q-Fibonacci polynomials which
for q=1 reduce to well-known results about Fibonacci numbers and Fibonacci
polynomials.


title:
Tetra-maximal Neutrino Mixing and Its Implications on Neutrino
  Oscillations and Collider Signatures

abstract:
  We propose a novel neutrino mixing pattern in terms of only two small
integers 1 and 2 together with their square roots and the imaginary number $i$.
This ansatz is referred to as the "tetra-maximal" mixing because it can be
expressed as a product of four rotation matrices, whose mixing angles are all
\pi/4 in the complex plane. It predicts \theta_{12} = \arctan(2-\sqrt{2})
\approx 30.4^\circ, \theta_{13} = \arcsin[(\sqrt{2}-1)/(2\sqrt{2})] \approx
8.4^\circ, \theta_{23} = 45^\circ and \delta =90^\circ in the standard
parametrization, and the Jarlskog invariant of leptonic CP violation is found
to be {\cal J} = 1/32. These results are compatible with current data and can
soon be tested in a variety of neutrino oscillation experiments. Implications
of the tetra-maximal neutrino mixing on the decays of doubly-charged Higgs
bosons H^{\pm\pm} -> l^\pm_\alpha l^\pm_\beta (for \alpha, \beta = e, \mu,
\tau) are also discussed in the triplet seesaw mechanism at the TeV scale,
which will be explored at the upcoming LHC.


title:
A Measurement of the Spatial Distribution of Diffuse TeV Gamma Ray
  Emission from the Galactic Plane with Milagro

abstract:
  Diffuse $\gamma$-ray emission produced by the interaction of cosmic-ray
particles with matter and radiation in the Galaxy can be used to probe the
distribution of cosmic rays and their sources in different regions of the
Galaxy. With its large field of view and long observation time, the Milagro
Gamma Ray Observatory is an ideal instrument for surveying large regions of the
Northern Hemisphere sky and for detecting diffuse $\gamma$-ray emission at very
high energies. Here, the spatial distribution and the flux of the diffuse
$\gamma$-ray emission in the TeV energy range with a median energy of 15 TeV
for Galactic longitudes between 30$^\circ$ and 110$^\circ$ and between
136$^\circ$ and 216$^\circ$ and for Galactic latitudes between -10$^\circ$ and
10$^\circ$ are determined. The measured fluxes are consistent with predictions
of the GALPROP model everywhere except for the Cygnus region
($l\in[65^\circ,85^\circ]$). For the Cygnus region, the flux is twice the
predicted value. This excess can be explained by the presence of active cosmic
ray sources accelerating hadrons which interact with the local dense
interstellar medium and produce gamma rays through pion decay.


title: A Study of Soft Interactions at Ultra High Energies

abstract:
  We present and discuss our recent study of an eikonal two channel model, in
which we reproduce the soft total, integrated elastic and diffractive cross
sections, and the corresponding forward differential slopes in the ISR-Tevatron
energy range. Our study is extended to provide predictions at the LHC and
Cosmic Rays ene$ These are utilized to assess the role of unitarity at ultra
high energies, as well as predict the implied survival probability of exclusive
diffractiv$ central production of a light Higgs. Our approach is critically
examined so as to estimate the margins of error of the calculated survival
probability for diffractive Higgs production


title: Normal and Anomalous Diffusion: A Tutorial

abstract:
  The purpose of this tutorial is to introduce the main concepts behind normal
and anomalous diffusion. Starting from simple, but well known experiments, a
series of mathematical modeling tools are introduced, and the relation between
them is made clear. First, we show how Brownian motion can be understood in
terms of a simple random walk model. Normal diffusion is then treated (i)
through formalizing the random walk model and deriving a classical diffusion
equation, (ii) by using Fick's law that leads again to the same diffusion
equation, and (iii) by using a stochastic differential equation for the
particle dynamics (the Langevin equation), which allows to determine the mean
square displacement of particles. (iv) We discuss normal diffusion from the
point of view of probability theory, applying the Central Limit Theorem to the
random walk problem, and (v) we introduce the more general Fokker-Planck
equation for diffusion that includes also advection. We turn then to anomalous
diffusion, discussing first its formal characteristics, and proceeding to
Continuous Time Random Walk (CTRW) as a model for anomalous diffusion. It is
shown how CTRW can be treated formally, the importance of probability
distributions of the Levy type is explained, and we discuss the relation of
CTRW to fractional diffusion equations and show how the latter can be derived
from the CTRW equations. Last, we demonstrate how a general diffusion equation
can be derived for Hamiltonian systems, and we conclude this tutorial with a
few recent applications of the above theories in laboratory and astrophysical
plasmas.


title: More transition amplitudes on the Riemann sphere

abstract:
  We consider a conformal field theory for bosons on the Riemann sphere.
Correlation functions are defined as singular limits of functional integrals.
The main result is that these amplitudes define transition amplitudes, that is
multilinear Hilbert-Schmidt functionals on a fixed Hilbert space.


title: Structure Formation independent of Cold Dark Matter

abstract:
  It is shown that a first-order cosmological perturbation theory for
Friedmann-Lemaitre-Robertson-Walker universes admits one and only one
gauge-invariant variable which describes the perturbation to the energy density
and which becomes equal to the usual energy density of the Newtonian theory of
gravity in the limit that all particle velocities are negligible with respect
to the speed of light. The same holds true for the perturbation to the particle
number density. A cosmological perturbation theory based on these particular
gauge-invariant quantities is more precise than any earlier first-order
perturbation theory. In particular, it explains star formation in a
satisfactory way, even in the absence of cold dark matter. In a baryon-only
universe, the earliest stars, the so-called Population III stars, are found to
have masses between 400 and 100,000 solar masses with a peak around 3400 solar
masses. If cold dark matter, with particle mass 10 times heavier than the
proton mass, is present then the star masses are between 16 and 4000 solar
masses with a peak around 140 solar masses. They come into existence between
100 Myr and 1000 Myr. At much later times, star formation is possible only in
high density regions, for example within galaxies. Late time stars may have
much smaller masses than early stars. The smallest stars that can be formed
have masses of 0.2--0.8 solar mass, depending on the initial internal relative
pressure perturbation. It is demonstrated that the Newtonian theory of gravity
cannot be used to study the evolution of cosmological density perturbations.


title: X-ray Dust Scattering at Small Angles: The Complete Halo around GX13+1

abstract:
  The exquisite angular resolution available with Chandra should allow
precision measurements of faint diffuse emission surrounding bright sources,
such as the X-ray scattering halos created by interstellar dust. However, the
ACIS CCDs suffer from pileup when observing bright sources, and this creates
difficulties when trying to extract the scattered halo near the source. The
initial study of the X-ray halo around GX13+1 using only the ACIS-I detector
done by Smith, Edgar & Shafer (2002) suffered from a lack of sensitivity within
50'' of the source, limiting what conclusions could be drawn.
  To address this problem, observations of GX13+1 were obtained with the
Chandra HRC-I and simultaneously with the RXTE PCA. Combined with the existing
ACIS-I data, this allowed measurements of the X-ray halo between 2-1000''.
After considering a range of dust models, each assumed to be smoothly
distributed with or without a dense cloud along the line of sight, the results
show that there is no evidence in this data for a dense cloud near the source,
as suggested by Xiang et al. (2005). Finally, although no model leads to
formally acceptable results, the Weingartner & Draine (2001) and nearly all of
the composite grain models from Zubko, Dwek & Arendt (2004) give poor fits.


title: Tripartite entanglement dynamics for atom in a two-mode nonlinear cavity

abstract:
  In this communication we introduce a new model which represents the
interaction between an atom and two fields injected simultaneously within a
cavity including the nonlinear couplers. By using the canonical transformation
the model can be regarded as a generalization of several well-known models. We
calculate and discuss entanglement between the tripartite system of one atom
and the two cavity modes. For a short interaction time, similarities between
the behavior based on our solution compared with the other simulation based on
a numerical linear algebra solution of the original Hamiltonian with truncated
Fock bases for each mode, is shown. For a specific value of the Kerr-like
medium defined in this letter, we find that the entanglement, as measured by
concurrence, may terminate abruptly in a finite time.


title:
Decoherence and entropy of primordial fluctuations II. The entropy
  budget

abstract:
  We calculate the entropy of adiabatic perturbations associated with a
truncation of the hierarchy of Green functions at the first non trivial level,
i.e. in a self-consistent Gaussian approximation. We give the equation
governing the entropy growth and discuss its phenomenology. It is parameterized
by two model-dependent kernels. We then examine two particular inflationary
models, one with isocurvature perturbations, the other with corrections due to
loops of matter fields. In the first model the entropy grows rapidely, while in
the second the state remains pure (at one loop).


title: Effect of Slow Switching in On-line Learning for Ensemble Teachers

abstract:
  We have analyzed the generalization performance of a student which slowly
switches ensemble teachers. By calculating the generalization error
analytically using statistical mechanics in the framework of on-line learning,
we show that the dynamical behaviors of generalization error have the
periodicity that is synchronized with the switching period and the behaviors
differ with the number of ensemble teachers. Furthermore, we show that the
smaller the switching period is, the larger the difference is.


title: Self-Feeding Turbulent Magnetic Reconnection on Macroscopic Scales

abstract:
  Within a MHD approach we find magnetic reconnection to progress in two
entirely different ways. The first is well-known: the laminar Sweet-Parker
process. But a second, completely different and chaotic reconnection process is
possible. This regime has properties of immediate practical relevance: i) it is
much faster, developing on scales of the order of the Alfv\'en time, and ii)
the areas of reconnection become distributed chaotically over a macroscopic
region. The onset of the faster process is the formation of closed circulation
patterns where the jets going out of the reconnection regions turn around and
forces their way back in, carrying along copious amounts of magnetic flux.


title:
Influence of Compton scattering on the broad-band X-ray spectra of
  intermediate polars

abstract:
  The majority of cataclysmic variables observed in the hard X-ray energy band
are intermediate polars where the magnetic field is strong enough to channel
the accreting matter to the magnetic poles of the white dwarf. A shock above
the stellar surface heats the gas to fairly high temperatures (10--100 keV).
The post-shock region cools mostly via optically thin bremsstrahlung. We
investigate the influence of Compton scattering on the structure and the
emergent spectrum of the post-shock region. We also study the effect it has on
the mass of the white dwarfs obtained from fitting the observed X-ray spectrum
of intermediate polars. We construct the model of the post-shock region taking
Compton scattering into account. The radiation transfer equation is solved in
the plane-parallel approximation. The feedback of Compton scattering on the
structure of the post-shock region is also accounted for. A set of the
post-shock region model spectra for various white dwarf masses is calculated.
We find that Compton scattering does not change the emergent spectra
significantly for low accretion rates or low white dwarf masses. However, it
becomes important at high accretion rates and high white dwarf masses. The
time-averaged, broad-band X-ray spectrum of intermediate polar V709 Cas
obtained by the RXTE and INTEGRAL observatories is fitted using the set of
computed spectral models. We obtained the white dwarf mass of 0.91 +/- 0.02
M_sun and 0.88 +/- 0.02 M_sun using models with Compton scattering taken into
account and without it, respectively.


title:
Cycles, determinism and persistence in agent-based games and financial
  time-series

abstract:
  The Minority Game (MG), the Majority Game (MAJG) and the Dollar Game ($G) are
important and closely-related versions of market-entry games designed to model
different features of real-world financial markets. In a variant of these
games, agents measure the performance of their available strategies over a
fixed-length rolling window of prior time-steps. These are the so-called Time
Horizon MG/MAJG/$G (THMG, THMAJG, TH$G). Their probabilistic dynamics may be
completely characterized in Markov-chain formulation. Games of both the
standard and TH variants generate time-series that may be understood as arising
from a stochastically perturbed determinism because a coin toss is used to
break ties. The average over the binomially-distributed coin-tosses yields the
underlying determinism. In order to quantify the degree of this determinism and
of higher-order perturbations, we decompose the sign of the time-series they
generate (analogous to a market price time series) into a superposition of
weighted Hamiltonian cycles on graphs (exactly in the TH variants and
approximately in the standard versions). The cycle decomposition also provides
a ``dissection'' of the internal dynamics of the games and a quantitative
measure of the degree of determinism. We discuss how the outperformance of
strategies relative to agents in the THMG (the ``illusion of control'') and the
reverse in the THMAJG and TH$G (i.e., genuine control) may be understood on a
cycle-by-cycle basis. The decomposition offers as well a new metric for
comparing different game dynamics to real-world financial time-series and a
method for generating predictors. We apply the cycle predictor a real-world
market, with significantly positive returns for the latter.


title: Small volume expansions for elliptic equations

abstract:
  This paper analyzes the influence of general, small volume, inclusions on the
trace at the domain's boundary of the solution to elliptic equations of the
form $\nabla \cdot D^\eps \nabla u^\eps=0$ or $(-\Delta + q^\eps) u^\eps=0$
with prescribed Neumann conditions. The theory is well-known when the
constitutive parameters in the elliptic equation assume the values of different
and smooth functions in the background and inside the inclusions. We generalize
the results to the case of arbitrary, and thus possibly rapid, fluctuations of
the parameters inside the inclusion and obtain expansions of the trace of the
solution at the domain's boundary up to an order $\eps^{2d}$, where $d$ is
dimension and $\eps$ is the diameter of the inclusion. We construct inclusions
whose leading influence is of order at most $\eps^{d+1}$ rather than the
expected $\eps^d$. We also compare the expansions for the diffusion and
Helmholtz equation and their relationship via the classical Liouville change of
variables.


title:
Increase of the wear resistance of carbide layers deposited by Pulsed
  Laser Deposition in addition with an auxiliary laser

abstract:
  Carbides stand out because of their high hardness and wear-resistance. Thus
these materials are often discussed for coatings of machine tools etc. Within
this work Boron Carbide (B4C) and Carbide (C) thin films were deposited on Si
(100) substrates by pulsed-laser deposition technique. In order to improve the
wear-resistance of the deposited films, we introduced a new working technique
including the application of a second excimer laser in a special working mode.
Thereby one laser was used to ablate the carbide material from a target and to
deposit the material on the substrate. The light of the second laser was
directed directly onto the substrate in order to modify the ablated material.
We report on details for film deposition and film properties determined by
Scanning Electron Microscope, Energy Dispersive X-Ray Spectroscopy, X-Ray
Diffraction, Rutherford Backscattering, Raman Spectroscopy and tribological
experiments.


title:
Rates of Processes with Coherent Production of Different Particles and
  the GSI Time Anomaly

abstract:
  With the help of an analogy with a double-slit experiment, it is shown that
the standard method of calculation of the rate of an interaction process by
adding the rates of production of all the allowed final states, regardless of a
possible coherence among them, is correct. It is a consequence of causality.
The claims that the GSI time anomaly is due to the mixing of neutrinos in the
final state of the electron-capture process are refuted. It is shown that the
GSI time anomaly may be due to quantum beats due to the existence of two
coherent energy levels of the decaying ion with an extremely small energy
splitting (about 10^{-15} eV) and relative probabilities having a ratio of
about 1/99.


title: Categorical formulation of quantum algebras

abstract:
  We describe how dagger-Frobenius monoids give the correct categorical
description of certain kinds of finite-dimensional 'quantum algebras'. We
develop the concept of an involution monoid, and use it to construct a
correspondence between finite-dimensional C*-algebras and certain types of
dagger-Frobenius monoids in the category of Hilbert spaces. Using this
technology, we recast the spectral theorems for commutative C*-algebras and for
normal operators into an explicitly categorical language, and we examine the
case that the results of measurements do not form finite sets, but rather
objects in a finite Boolean topos. We describe the relevance of these results
for topological quantum field theory.


title:
New Proof on some sharp double integral Inequalities of the
  Hermite-Hadamard Type

abstract:
  In this paper, we derive a new proof on some sharp double integral
inequalities of the Hermite-Hadamard type. Our approach is mainly based on
well-known Taylor's theorem with the integral remainder.


title:
Connected components of strata of quadratic differentials over
  Teichmuller space

abstract:
  In this paper, we study connected components of strata of the space of
quadratic differentials lying over $\T_g$. We use certain general properties of
sections of line bundles to put a upper bound on the number of connected
components, and a generalized version of the Gauss map as an invariant to put a
lower bound on the number of such components. For strata with sufficiently many
zeroes of the same order we can state precisely the number of components.


title: The GSI method for studying neutrino mass differences - For Pedestrians

abstract:
  A new experiment studying the behavior of a radioactive ion before its weak
decay by K-capture suggests that neutrino masses and mixing can be investigated
without detecting the neutrino. Every weak decay can be observed, thus avoiding
the suppression by the low neutrino absorption cross section of the signal in
conventional neutrino oscillation experiments. The normally unobservable long
wave lengths are made observable by having the radioactive source move a long
distance circulating around in a storage ring. A new oscillation phenomenon
with nonexponential decay arises in this "watched pot" experiment where
continous monitoring sets the decay clock back to zero while preserving
oscillating phases in the initial state. The initial ion wave packet has a
momentum spread required by Heisenberg and contains pairs of components with
different momenta and energies. These can produce neutrino amplitudes in two
mass eigenstates with different momenta which mix to produce a single $\nu_e$
state. In this typical quantum mechanics "two-slit" or "which path" experiment
a transition between the same initial and final states can go via two paths in
energy-momentum space. Their relative phases change with the propagation of the
initial state between the points of entry and decay. The oscillations produced
by these phase changes are shown to be consistent with quantum mechanics and
causality.


title:
Observation of Relaxation Phenomena in Thermophysical Properties of
  Alloys and Metals

abstract:
  In this paper the proposal for the study of the second sound in medium is
presented. The master equation is derived and its solution is obtained, The
properties of alloys with very long relaxation times, as the examples for the
proposed study are discussed


title: Motivic Integration on Toric Stacks

abstract:
  We present a decomposition of the space of twisted arcs of a toric stack. As
a consequence, we give a combinatorial description of the motivic integral
associated to a torus-invariant divisor of a toric stack.


title: Network-based consensus averaging with general noisy channels

abstract:
  This paper focuses on the consensus averaging problem on graphs under general
noisy channels. We study a particular class of distributed consensus algorithms
based on damped updates, and using the ordinary differential equation method,
we prove that the updates converge almost surely to exact consensus for finite
variance noise. Our analysis applies to various types of stochastic
disturbances, including errors in parameters, transmission noise, and
quantization noise. Under a suitable stability condition, we prove that the
error is asymptotically Gaussian, and we show how the asymptotic covariance is
specified by the graph Laplacian. For additive parameter noise, we show how the
scaling of the asymptotic MSE is controlled by the spectral gap of the
Laplacian.


title: Denominators in cluster algebras of affine type

abstract:
  The Fomin-Zelevinsky Laurent phenomenon states that every cluster variable in
a cluster algebra can be expressed as a Laurent polynomial in the variables
lying in an arbitrary initial cluster. We give representation-theoretic
formulas for the denominators of cluster variables in cluster algebras of
affine type. The formulas are in terms of the dimensions of spaces of
homomorphisms in the corresponding cluster category, and hold for any choice of
initial cluster.


title:
Scaling the neutral atom Rydberg gate quantum computer by collective
  encoding in Holmium atoms

abstract:
  We discuss a method for scaling a neutral atom Rydberg gate quantum processor
to a large number of qubits. Limits are derived showing that the number of
qubits that can be directly connected by entangling gates with errors at the
$10^{-3}$ level using long range Rydberg interactions between sites in an
optical lattice, without mechanical motion or swap chains, is about 500 in two
dimensions and 7500 in three dimensions. A scaling factor of 60 at a smaller
number of sites can be obtained using collective register encoding in the
hyperfine ground states of the rare earth atom Holmium. We present a detailed
analysis of operation of the 60 qubit register in Holmium. Combining a lattice
of multi-qubit ensembles with collective encoding results in a feasible design
for a 1000 qubit fully connected quantum processor.


title: Uniform Bounds on Pre-Images under Quadratic Dynamical Systems

abstract:
  For any elements b,c of a number field K, let G(b,c) denote the backwards
orbit of b under the map f_c: C-->C given by f_c(x)=x^2+c. We prove an upper
bound on the number of elements of G(b,c) whose degree over K is at most some
constant B. This bound depends only on b, [K:Q], and B, and is valid for all b
outside an explicit finite set. We also show that, for any N>3 and any b in K
outside a finite set, there are only finitely many pairs of complex numbers
(y,c) for which [K(y,c):K]<2^(N-3) and the value of the N-th iterate of f_c(x)
at x=y is b. Moreover, the bound 2^(N-3) in this result is optimal.


title:
Instability of Boost-invariant hydrodynamics with a QCD inspired bulk
  viscosity

abstract:
  We solve the relativistic Navier-Stokes equations with homogeneous
boost-invariant boundary conditions, and perform a stability analysis of the
solution. We show that, if the bulk viscosity has a peak around $T_c$ as
inferred from QCD-based arguments, the background solution "freezes" at $T_c$
to a nearly constant temperature state. This state is however highly unstable
with respect to certain inhomogeneous modes. Calculations show that these modes
have enough time to blow up and tear the system into droplets. We conjecture
that this is how freeze-out occurs in the QGP created in heavy ion collisions,
and perhaps similar transitions in the early universe.


title:
Calculated magneto-resistance due to domain walls : the role of impurity
  scattering

abstract:
  The existing Levy-Zhang approach to constructing the contribution to the
resistivity of a magnetic domain wall is explored. The model equations are
integrated analytically, giving a closed form expression for the resistivity
when the current flows in the wall. The Boltzmann equation is solved
analytically and the ratio of the spin up and spin down resistivities is
calculated and its dependence on the strength of the Coulomb and exchange
scattering potentials is elucidated.


title: Two-enqueuer queue in Common2

abstract:
  The question of whether all shared objects with consensus number 2 belong to
Common2, the set of objects that can be implemented in a wait-free manner by
any type of consensus number 2, was first posed by Herlihy. In the absence of
general results, several researchers have obtained implementations for
restricted-concurrency versions of FIFO queues. We present the first Common2
algorithm for a queue with two enqueuers and any number of dequeuers.


title:
Simultaneous numerical simulation of direct and inverse cascades in wave
  turbulence

abstract:
  Results of direct numerical simulation of isotropic turbulence of surface
gravity waves in the framework of Hamiltonian equations are presented. For the
first time simultaneous formation of both direct and inverse cascades was
observed in the framework of primordial dynamical equations. At the same time,
strong long waves background was developed. It was shown, that obtained
Kolmogorov spectra are very sensitive to the presence of this condensate. Such
situation has to be typical for experimental wave tanks, flumes, and small
lakes.


title: Moment determinants as isomonodromic tau functions

abstract:
  We consider a wide class of determinants whose entries are moments of the
so-called semiclassical functionals and we show that they are tau functions for
an appropriate isomonodromic family which depends on the parameters of the
symbols for the functionals. This shows that the vanishing of the tau-function
for those systems is the obstruction to the solvability of a Riemann-Hilbert
problem associated to certain classes of (multiple) orthogonal polynomials. The
determinants include Haenkel, Toeplitz and shifted-Toeplitz determinants as
well as determinants of bimoment functionals and the determinants arising in
the study of multiple orthogonality. Some of these determinants appear also as
partition functions of random matrix models, including an instance of a
two-matrix model.


title: The mixing advantage is less than 2

abstract:
  Corresponding to $n$ independent non-negative random variables $X_1,...,X_n$,
are values $M_1,...,M_n$, where each $M_i$ is the expected value of the maximum
of $n$ independent copies of $X_i$. We obtain an upper bound to the expected
value of the maximum of $X_1,...,X_n$ in terms of $M_1,...,M_n$. This
inequality is sharp in the sense that the quantity and its bound can be made as
close to each other as we want. We also present related comparison results.


title: Pryce-Hoyle Tensor in a Combined Einstein-Cartan-Brans-Dicke Model

abstract:
  In addition to introducing matter injection through a scalar field determined
by Pryce-Hoyle tensor, we also combine it with a BCDE
(Brans-Dicke-Einstein-Cartan) theory with lambdaterm developed earlier by
Berman(2008), for inflationary scenario. It involves a variable cosmological
constant, which decreases with time, jointly with energy density, cosmic
pressure, shear, vorticity, and Hubble's parameter, while the scale factor,
total spin and scalar field increase exponentially. The post-inflationary fluid
resembles a perfect one, though total spin grows, but not the angular speed
(Berman, 2007d). The Pryce-Hoyle tensor, which can measured by the number of
injected particles per unit proper volume and time, as well as shear and
vorticity, can be neglected in the aftermath of inflation ("no-hair").


title:
Diffusing non-local inflation: Solving the field equations as an initial
  value problem

abstract:
  There has been considerable recent interest in solving non-local equations of
motion which contain an infinite number of derivatives. Here, focusing on
inflation, we review how the problem can be reformulated as the question of
finding solutions to a diffusion-like partial differential equation with
non-linear boundary conditions. Moreover, we show that this diffusion-like
equation, and hence the non-local equations, can be solved as an initial value
problem once non-trivial initial data consistent with the boundary conditions
is found. This is done by considering linearised equations about any field
value, for which we show that obtaining solutions using the diffusion-like
equation is equivalent to solving a local but infinite field cosmology. These
local fields are shown to consist of at most two canonically normalized or
phantom fields together with an infinite number of quintoms. We then
numerically solve the diffusion-like equation for the full non-linear case for
two string field theory motivated models.


title: Recurrent frequency-size distribution of characteristic events

abstract:
  Many complex systems, including sand-pile models, slider-block models, and
earthquakes, have been discussed whether they obey the principles of
self-organized criticality. Behavior of these systems can be investigated from
two different points of view: interoccurrent behavior in a region and recurrent
behavior at a given point on a fault or at a given fault. The interoccurrent
frequency-size statistics are known to be scale-invariant and obey the
power-law Gutenberg-Richter distribution. This paper investigates the recurrent
frequency-size behavior of characteristic events at a given point on a fault or
at a given fault. For this purpose sequences of creep events at a creeping
section of the San Andreas fault are investigated. The applicability of the
Brownian passage-time, lognormal, and Weibull distributions to the recurrent
frequency-size statistics of slip events is tested and the Weibull distribution
is found to be a best-fit distribution. To verify this result the behaviors of
the numerical slider-block and sand-pile models are investigated and the
applicability of the Weibull distribution is confirmed. Exponents of the
best-fit Weibull distributions for the observed creep event sequences and for
the slider-block model are found to have close values from 1.6 to 2.2 with the
corresponding aperiodicities of the applied distribution from 0.47 to 0.64.


title: Millimeter Imaging of HH 24 MMS: A Misaligned Protobinary System

abstract:
  The HH 24 MMS protostellar system was observed in the 6.9 mm continuum with a
high angular resolution (0.5"). HH 24 MMS was resolved into two sources. The
separation between sources 1 and 2 is ~0.9" or 360 AU. The spectral energy
distribution suggests that the 6.9 mm flux is almost entirely from dust. The
6.9 mm image and the spectrum suggest that HH 24 MMS may be a protostellar
binary system. Total mass including the accretion disks and the inner
protostellar envelope is ~1.4 Msun. Disk masses of sources 1 and 2 are 0.6 and
0.3 Msun, respectively. Both sources are highly elongated. The difference in
the position angle of the two disks is ~45 degree, which means that HH 24 MMS
is a highly misaligned protobinary system. The misalignment suggests that
turbulent fragmentation may be the formation mechanism relevant to the binary
systems with a separation of a few hundreds of AU, such as the HH 24 MMS
system.


title: Chaotic singular maps

abstract:
  We consider a family of singular maps as an example of a simple model of
dynamical systems exhibiting the property of robust chaos on a well defined
range of parameters. Critical boundaries separating the region of robust chaos
from the region where stable fixed points exist are calculated on the parameter
space of the system. It is shown that the transitions to robust chaos in these
systems occur either through the routes of type-I or type-III intermittency and
the critical boundaries for each type of transition have been determined on the
phase diagram of the system. The simplicity of these singular maps and the
robustness of their chaotic dynamics make them useful ingredients in the
construction of models and in applications that require reliable operation
under chaos.


title:
Conserved Quantities and the Algebra of Braid Excitations in Quantum
  Gravity

abstract:
  We derive conservation laws from interactions of braid-like excitations of
embedded framed spin networks in Quantum Gravity. We also demonstrate that the
set of stable braid-like excitations form a noncommutative algebra under braid
interaction, in which the set of actively-interacting braids is a subalgebra.


title: Tuning of energy levels and optical properties of graphene quantum dots

abstract:
  We investigate theoretically the magnetic levels and optical properties of
zigzag- and armchair-edged hexagonal graphene quantum dots (GQDs) utilizing the
tight-binding method. A new bound edge state at zero energy appears for the
zigzag GQDs in the absence of a magnetic field. The magnetic levels of GQDs
exhibit a Hofstadter-butterfly spectrum and approach the Landau levels of
two-dimensional graphene as the magnetic field increases. The optical
properties are tuned by the size, the type of the edge, and the external
magnetic field.


title:
From a set of parts to an indivisible whole. Part II: Operations in an
  open comparative mode

abstract:
  This paper describes a new method, HGV2C, for pattern analysis. The HGV2C
method involves the construction of a computer ego (CE) based on an individual
object that can be either a part of the system under analysis or a newly
created object based on a certain hypothesis. The CE provides a capability to
analyze data from a specific standpoint, e.g. from a viewpoint of a certain
object. The CE is constructed from two identical copies of a query object, and
its functioning mechanism involves: a hypothesis-parameter (HP) and
infothyristor (IT). HP is a parameter that is introduced into an existing set
of parameters. The HP value for one of the clones of a query object is set to
equal 1, whereas for another clone it is greater than 1. The IT is based on the
previously described algorithm of iterative averaging and performs three
functions: 1) computation of a similarity matrix for the group of three objects
including two clones of a query object and a target object; 2) division of the
group into two alternative subgroups; and 3) a successive increase of the HP
weight in the totality of all the parameters. Initially, both clones of the
query object appear together in one of the subgroups as all of their parameter
values, except the HP, are identical. At a certain point of the HP
multiplication, one of the clones moves to the group of the target object. A
respective number of the HP multiplications represents the dissimilarity (D)
between the query and target objects. The product of D multiplied by the
difference in HP values of the clones is strictly constant and linearly
increases as the difference in HP values of the clones decreases. This new
approach to knowledge representation is demonstrated on the example of
population pyramids of 220 countries.


title: Electroproduction of electron-positron pair in a medium

abstract:
  The process of electron-positron pair creation by a high-energy electron in a
medium is analyzed. The spectral distribution over energies of created
particles is calculated for the direct and cascade mechanisms of the process.
The Coulomb corrections are included. The new formulation of the equivalent
photons method is developed which takes into account the influence of multiple
scattering. It is shown the effects of multiple scattering can be quite
effectively studied in the process under consideration.


title: Repulsive shield between polar molecules

abstract:
  We propose and analyze a technique that allows to suppress inelastic
collisions and simultaneously enhance elastic interactions between cold polar
molecules. The main idea is to cancel the leading dipole-dipole interaction
with a suitable combination of static electric and microwave fields in such a
way that the remaining van-der-Waals-type potential forms a three-dimensional
repulsive shield. We analyze the elastic and inelastic scattering cross
sections relevant for evaporative cooling of polar molecules and discuss the
prospect for the creation of crystalline structures.


title:
The Elliptic Hypergeometric Functions Associated to the Configuration
  Space of Points on an Elliptic Curve I : Twisted Cycles

abstract:
  We consider the Euler type integral associated to the configuration space of
points on an elliptic curve, which is an analogue of the hypergeometric
function associated to the configuration space of points on a projective line.
We calculate the {\it twisted homology group}, with coefficients in the local
system associated to a power function $g^{\alpha}$ of an elliptic function $g$,
and the intersection form. Applying these calculations, we describe the {\it
connection matrices} representing the linear isomorphisms induced from analytic
continuations of the functions defined by the integrations of $g^{\alpha}$ over
twisted cycles.


title: Phase transition in SONFIS&SORST

abstract:
  In this study, we introduce general frame of MAny Connected Intelligent
Particles Systems (MACIPS). Connections and interconnections between particles
get a complex behavior of such merely simple system (system in
system).Contribution of natural computing, under information granulation
theory, are the main topics of this spacious skeleton. Upon this clue, we
organize two algorithms involved a few prominent intelligent computing and
approximate reasoning methods: self organizing feature map (SOM), Neuro- Fuzzy
Inference System and Rough Set Theory (RST). Over this, we show how our
algorithms can be taken as a linkage of government-society interaction, where
government catches various fashions of behavior: solid (absolute) or flexible.
So, transition of such society, by changing of connectivity parameters (noise)
from order to disorder is inferred. Add to this, one may find an indirect
mapping among financial systems and eventual market fluctuations with MACIPS.
Keywords: phase transition, SONFIS, SORST, many connected intelligent particles
system, society-government interaction


title: Molecular Thin Films: a New Type of Magnetic Switch

abstract:
  The design and fabrication of materials that exhibit both semiconducting and
magnetic properties for spintronics and quantum computing has proven difficult.
Important starting points are high-purity thin films as well as fundamental
theoretical understanding of the magnetism. Here we show that small molecules
have great potential in this area, due to ease of insertion of localised spins
in organic frameworks and both chemical and structural purity. In particular,
we demonstrate that archetypal molecular semiconductors, namely the metal
phthalocyanines (Pc), can be readily fabricated as thin film quantum
antiferromagnets, important precursors to a solid state quantum computer. Their
magnetic state can be switched via fabrication steps which modify the film
structure, offering practical routes into information processing. Theoretical
calculations show that a new mechanism, which is the molecular analogue of the
interactions between magnetic ions in metals, is responsible for the magnetic
states. Our combination of theory and experiments opens the field of organic
thin film magnetic engineering.


title:
Atomic calculations and search for variation of the fine structure
  constant in quasar absorption spectra

abstract:
  A brief review of the search for variation of the fine structure constant in
quasar absorption spectra is presented. Special consideration is given to the
role of atomic calculations in the analysis of the observed data. A range of
methods which allow to perform calculations for atoms or ions with different
electron structure and which cover practically all periodic table of elements
is discussed. Critical compilation of the results of the calculations as well
as a review of the most recent results of the analysis are presented.


title:
Search for variation of the fundamental constants in atomic, molecular
  and nuclear spectra

abstract:
  The search for variation of the fundamental constants such as the fine
structure constant $\alpha$ ($\alpha=e^2/\hbar c$) and the ratios of
fundamental masses (e.g., electron to proton mass ratio $\mu=m_e/m_p$) is
reviewed. Strong emphasis is given to establishing the relationships between
the change in the measured frequencies of atomic, molecular or nuclear
transitions and the corresponding change of the fundamental constants.
Transitions in which the sensitivity of the frequency change to the variation
of the fine structure constant is strongly enhanced are discussed and most
recent experimental results are presented. Most attention is given to the use
of atomic, molecular and nuclear transitions in the study of quasar absorption
spectra and in atomic clock experiments.


title:
Distance-based clustering of sparsely observed stochastic processes,
  with applications to online auctions

abstract:
  We propose a distance between two realizations of a random process where for
each realization only sparse and irregularly spaced measurements with
additional measurement errors are available. Such data occur commonly in
longitudinal studies and online trading data. A distance measure then makes it
possible to apply distance-based analysis such as classification, clustering
and multidimensional scaling for irregularly sampled longitudinal data. Once a
suitable distance measure for sparsely sampled longitudinal trajectories has
been found, we apply distance-based clustering methods to eBay online auction
data. We identify six distinct clusters of bidding patterns. Each of these
bidding patterns is found to be associated with a specific chance to obtain the
auctioned item at a reasonable price.


title:
Twisted Poincar\'e Lemma and Twisted \v{C}ech-de Rham Isomorphism in
  case of Projective Line

abstract:
  In this paper, we give a direct proof of the twisted Poincar\'{e} lemma by
using the integrations over regularized paths. This method tells us a concrete
description of the \v{C}ech-de Rham isomorphism.


title:
Consistency of restricted maximum likelihood estimators of principal
  components

abstract:
  In this paper we consider two closely related problems : estimation of
eigenvalues and eigenfunctions of the covariance kernel of functional data
based on (possibly) irregular measurements, and the problem of estimating the
eigenvalues and eigenvectors of the covariance matrix for high-dimensional
Gaussian vectors. In Peng and Paul (2007), a restricted maximum likelihood
(REML) approach has been developed to deal with the first problem. In this
paper, we establish consistency and derive rate of convergence of the REML
estimator for the functional data case, under appropriate smoothness
conditions. Moreover, we prove that when the number of measurements per sample
curve is bounded, under squared-error loss, the rate of convergence of the REML
estimators of eigenfunctions is near-optimal. In the case of Gaussian vectors,
asymptotic consistency and an efficient score representation of the estimators
are obtained under the assumption that the effective dimension grows at a rate
slower than the sample size. These results are derived through an explicit
utilization of the intrinsic geometry of the parameter space, which is
non-Euclidean. Moreover, the results derived in this paper suggest an
asymptotic equivalence between the inference on functional data with dense
measurements and that of the high dimensional Gaussian vectors.


title: A search for OH 6 GHz maser emission towards supernova remnants

abstract:
  OH masers at 1720 MHz have proven to be excellent indicators of interactions
between supernova remnants and molecular clouds. OH excitation calculations
suggest that the 6049 MHz OH maser line is excited for higher column densities
than for the 1720 MHz line. Previous observations and modelling of 1612, 1665
and 1667 MHz OH absorption and 1720 MHz OH masers indicated that the column
densities in some supernova remnants, ~1e17 cm^-2, may be high enough for 6049
MHz OH masers to exist. It is therefore a potentially valuable indicator of
remnant-cloud interaction.
  We present excitation calculations predicting the formation of 6049 MHz OH
masers and results of a survey using the Parkes Methanol Multibeam receiver for
6049, 6035 and 6030 MHz OH masers towards 35 supernova remnants, a star-forming
region and 4 fields in the Large and Small Magellanic Clouds.
  Two new sites of 6035 and 6030 MHz OH maser emission associated with
star-forming regions have been discovered, but no 6049 MHz masers were detected
to a brightness temperature limit of ~0.3-0.6 K, even though modelling of the
OH excitation suggests that maser emission should have been detected. Our
upper-limits indicate that the OH column density for a typical remnant is less
than 1e16.4 cm^-2, which conflicts with observed and modelled column densities.
One possible explanation is that 6049 MHz OH masers may be more sensitive to
velocity coherence than 1720 MHz OH masers under some conditions.


title: Stanley decompositions and localization

abstract:
  We study the behavior of Stanley depth under the operation of localization
with respect to a variable.


title:
Lie Algebras : Classifications, Deformations, Rigidity and Differential
  Geometry

abstract:
  This is a short presentation of some classical results on finite dimensional
complex Lie algebras (classification of nilpotent Lie algebras, deformations
and perturbations, contractions and rigidity). We present some applications to
Differential Geometry considering some left invariant structures on Lie groups
: contact and symplectic structures, Generalized complex structures on real Lie
Group. We present also the notion of riemannian and pseudo-riemannian
G-symmetric spaces.


title: Sequence-Dependent Effects on the Properties of Semiflexible Biopolymers

abstract:
  Using path integral technique, we show exactly that for a semiflexible
biopolymer in constant extension ensemble, no matter how long the polymer and
how large the external force, the effects of short range correlations in the
sequence-dependent spontaneous curvatures and torsions can be incorporated into
a model with well-defined mean spontaneous curvature and torsion as well as a
renormalized persistence length. Moreover, for a long biopolymer with large
mean persistence length, the sequence-dependent persistence lengths can be
replaced by their mean. However, for a short biopolymer or for a biopolymer
with small persistence lengths, inhomogeneity in persistence lengths tends to
make physical observables very sensitive to details and therefore less
predictable.


title:
Orbital degeneracy, Hund's coupling, and band ferromagnetism: effective
  quantum parameter, suppression of quantum corrections, and enhanced stability

abstract:
  An effective quantum parameter is obtained for the band ferromagnet in terms
of orbital degeneracy and Hund's coupling. This quantum parameter determines,
in analogy with 1/N for the generalized Hubbard model and 1/S for quantum spin
systems, the strength of quantum corrections to spin stiffness and spin-wave
energies. Quantum corrections are obtained by incorporating correlation effects
in the form of self-energy and vertex corrections within a
spin-rotationally-symmetric approach in which the Goldstone mode is explicitly
preserved order by order. It is shown that even a relatively small Hund's
coupling is rather efficient in strongly suppressing quantum corrections,
especially for large N, resulting in strongly enhanced stability of the
ferromagnetic state. This mechanism for the enhancement of ferromagnetism by
Hund's coupling implicitly involves a subtle interplay of lattice,
dimensionality, band dispersion, spectral distribution, and band filling
effects.


title: Properties of Quarkonia at T_c

abstract:
  We discuss how the spectral changes of quarkonia at T_c can reflect the
``critical'' behaviour of QCD phase transition. Starting from the temperature
dependencies of the energy density and pressure from lattice QCD calculation,
we extract the temperature dependencies of the scalar and spin 2 gluon
condensates near T_c. We also parameterize these changes into the electric and
magnetic condensate near T_c. While the magnetic condensate hardly changes
across T_c, we find that the electric condensate increases abruptly above T_c.
Similar abrupt change is also seen in the scalar condensate. Using the QCD
second-order Stark effect and QCD sum rules, we show that these sudden changes
induce equally abrupt changes in the mass and width of J/psi, both of which are
larger than 100 MeV at slightly above T_c.


title:
Validating Time-Distance Far-side Imaging of Solar Active Regions
  through Numerical Simulations

abstract:
  Far-side images of solar active regions have become one of the routine
products of helioseismic observations, and are of importance for space weather
forecasting by allowing the detection of sunspot regions before they become
visible on the Earth side of the Sun. An accurate assessment of the quality of
the far-side maps is difficult, because there are no direct observations of the
solar far side to verify the detections. In this paper we assess far-side
imaging based on the time-distance helioseismology method, by using numerical
simulations of solar oscillations in a spherical solar model. Localized
variations in the speed of sound in the surface and subsurface layers are used
to model the perturbations associated with sunspots and active regions. We
examine how the accuracy of the resulting far-side maps of acoustic travel
times depends on the size and location of active regions. We investigate
potential artifacts in the far-side imaging procedure, such as those caused by
the presence of active regions on the solar near side, and suggest how these
artifacts can be identified in the real Sun far-side images obtained from
SOHO/MDI and GONG data.


title: Microtribological Property of Vertically Aligned Carbon Nanotube Film

abstract:
  Microtribological properties of vertically-aligned carbon-nanotube (VACNT)
films have been studied. Adhesion forces were obtained by measuring
force-displacement curves. Friction experiments were conducted in reciprocating
sliding configurations. Effects of tip radius, applied force, scan speed, and
relative humidity were investigated. A model of the friction of VACNT film is
discussed on the basis of in-situ tribological experiments inside a scanning
electron microscope (SEM).


title:
High-resolution double morphology of the most distant known radio quasar
  at z=6.12

abstract:
  Context: The highest redshift quasars at z>~6 receive considerable attention
since they provide strong constraints on the growth of the earliest
supermassive black holes. They also probe the epoch of reionisation and serve
as "lighthouses" to illuminate the space between them and the observer. The
source J1427+3312 (z=6.12) has recently been identified as the first and so far
the only known radio-loud quasar at z>6.
  Aims: We investigated the compact radio structure of J1427+3312 on
milli-arcsecond (mas) angular scales, to compare it with that of the second
most distant radio-loud quasar J0836+0054 (z=5.77) and with lower-redshift
radio quasars in general. Methods: We observed J1427+3312 in phase-reference
mode with ten antennas of the European Very Long Baseline Interferometry (VLBI)
Network (EVN) at 1.6 GHz on 11 March 2007 and at 5 GHz on 3 March 2007.
Results: The source was clearly detected at both frequencies. At 1.6 GHz, it
shows a prominent double structure. The two components are separated by 8.3
mas, corresponding to a projected linear distance of ~160 pc. Both components
with sub-mJy flux densities appear resolved. In the position of the brightest
component at 1.6 GHz, we detected mas-scale radio emission at 5 GHz as well.
The radio spectrum of this feature is steep. The double structure and the
separation of the components of J1427+3312 are similar to those of the young
(<~10^4 yr) compact symmetric objects (CSOs).


title: Sodium Trimer Ordering on NaxCoO2 Surface

abstract:
  Sodium ion ordering on in situ cleaved NaxCoO2 (x=0.84) surface has been
studied by ultra high vacuum scanning tunneling microscopy (UHV-STM) at room
temperature. Three main phases, with p(3x3), (root 7 x root 7), and (2 root 3 x
2 root 3) hexagonal unit cells and surface Na concentration of 1/3, 3/7, 1/2,
respectively, were identified. One surprising finding is that Na trimers act as
the basic building blocks that order in long range. The stability of Na trimers
is attributed to the increased Na coordination with oxygen as indicated by ab
initio calculations, and possibly at finite temperature by configuration
entropy.


title:
An Accretion-Disc Model for the Algol-Type Eclipsing Binary System AV
  Del

abstract:
  This study inspects the light and radial-velocity curves of the eclipsing
binary AV Del. In comparison with other studies already done, the study shows
that the absolute elements, fundamental orbital and physical parameters of the
system can be determined using the Wilson-Devinney code. Using these
parameters, the configuration of the system is presented. Then, an accretion
disc model for the system is introduced by using the SHELLSPEC code. The
results indicate that AV Del is a semi-detached system in which an optically
thick accretion disc is surrounding the primary star. The outer radius of the
disc is 8.0 R_sun}, corresponding to a distance of 1.1 R_sun} from the surface
of the secondary. Also, the temperature of the disc is calculated to be T=5700
K.


title: Probing a Bose-Einstein Condensate with an Atom Laser

abstract:
  A pulsed atom laser derived from a Bose-Einstein condensate is used to probe
a second target condensate. The target condensate scatters the incident atom
laser pulse. From the spatial distribution of scattered atoms, one can infer
important properties of the target condensate and its interaction with the
probe pulse. As an example, we measure the s-wave scattering length that, in
low energy collisions, describes the interaction between the |F=1,m_F=-1> and
|F=2,m_F=0> hyperfine ground states in 87Rb.


title:
Zitterbewegung (trembling motion) of electrons in narrow gap
  semiconductors

abstract:
  Theory of trembling motion [Zitterbewegung (ZB)] of charge carriers in
various narrow-gap materials is reviewed. Nearly free electrons in a periodic
potential, InSb-type semiconductors, bilayer graphene, monolayer graphene and
carbon nanotubes are considered. General features of ZB are emphasized. It is
shown that, when the charge carriers are prepared in the form of Gaussian wave
packets, the ZB has a transient character with the decay time of femtoseconds
in graphene and picoseconds in nanotubes. Zitterbewegung of electrons in
graphene in the presence of an external magnetic field is mentioned. A
similarity of ZB in semiconductors to that of relativistic electrons in a
vacuum is stressed. Possible ways of observing the trembling motion in solids
are mentioned.


title:
Mass spectra of the heavy baryons Lambda_Q and Sigma_Q^(*) from QCD sum
  rules

abstract:
  We use QCD sum rule approach to calculate the masses of the ground-state
Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to
dimension six are included in operator product expansion. The resulting heavy
baryonic masses from the calculations are m_{Lambda_b}=5.69 +/- 0.13 GeV, and
m_{Lambda_c}=2.31 +/- 0.19 GeV for Lambda_Q; m_{Sigma_b}=5.73 +/- 0.21 GeV,
m_{Sigma_b^*}=5.81 +/- 0.19 GeV, m_{Sigma_c}=2.40 +/- 0.31 GeV and
m_{Sigma_c^*}=2.56 +/- 0.24 GeV for Sigma_Q^(*), respectively, which are in
good agreement with the experimental values.


title: Spectral gap for the interchange process in a box

abstract:
  We show that the spectral gap for the interchange process (and the symmetric
exclusion process) in a $d$-dimensional box of side length $L$ is asymptotic to
$\pi^2/L^2$. This gives more evidence in favor of Aldous's conjecture that in
any graph the spectral gap for the interchange process is the same as the
spectral gap for a corresponding continuous-time random walk. Our proof uses a
technique that is similar to that used by Handjani and Jungreis, who proved
that Aldous's conjecture holds when the graph is a tree.


title:
Evolution of Cooperation and Coordination in a Dynamically Networked
  Society

abstract:
  Situations of conflict giving rise to social dilemmas are widespread in
society and game theory is one major way in which they can be investigated.
Starting from the observation that individuals in society interact through
networks of acquaintances, we model the co-evolution of the agents' strategies
and of the social network itself using two prototypical games, the Prisoner's
Dilemma and the Stag Hunt. Allowing agents to dismiss ties and establish new
ones, we find that cooperation and coordination can be achieved through the
self-organization of the social network, a result that is non-trivial,
especially in the Prisoner's Dilemma case. The evolution and stability of
cooperation implies the condensation of agents exploiting particular game
strategies into strong and stable clusters which are more densely connected,
even in the more difficult case of the Prisoner's Dilemma.


title: Atomic spin squeezing in an optical cavity

abstract:
  We consider squeezing of one component of the collective spin vector of an
atomic ensemble inside an optical cavity. The atoms interact with a cavity
mode, and the squeezing is obtained by probing the state of the light field
that is transmitted through the cavity. Starting from the stochastic master
equation, we derive the time evolution of the state of the atoms and the cavity
field, and we compute expectation values and variances of the atomic spin
components and the quadratures of the cavity mode. The performance of the setup
is compared to spin squeezing of atoms by probing of a light field transmitted
only once through the sample.


title: The Lorentz integral transform (LIT) method

abstract:
  The LIT approach is reviewed both for inclusive and exclusive reactions. It
is shown that the method reduces a continuum state problem to a
bound-state-like problem, which then can be solved with typical bound-state
techniques. The LIT approach opens up the possibility to perform ab initio
calculations of reactions also for those particle systems which presently are
out of reach in conventional approaches with explicit calculations of many-body
continuum wave functions. Various LIT applications are discussed ranging from
particle systems with two nucleons up to particle systems with seven nucleons.


title:
Evolution of the genetic code. From the CG- to the CGUA-alphabet, from
  RNA double helix to DNA

abstract:
  A hypothesis of the evolution of the genetic code is proposed, the leading
mechanism of which is the nucleotide spontaneous damage leading to
AT-enrichment of the genome. The hypothesis accounts for stability of the
genetic code towards point mutations, the presence of code dialects, emergence
of stop codons, emergence of the DNA double helix and the symmetry of the
genetic code table. The assumption of the originally triplet structure of the
genetic code has been substantiated. A hypothesis concerning the primary
structure of the first gene and the first protein has been proposed.


title: Visualizing the spin of individual molecules

abstract:
  Low-temperature spin-polarized scanning tunneling microscopy is employed to
study spin transport across single Cobalt-Phathalocyanine molecules adsorbed on
well characterized magnetic nanoleads. A spin-polarized electronic resonance is
identified over the center of the molecule and exploited to spatially resolve
stationary spin states. These states reflect two molecular spin orientations
and, as established by density functional calculations, originate from a
ferromagnetic molecule-lead superexchange interaction mediated by the organic
ligands.


title:
Gravitational waves about curved backgrounds: a consistency analysis in
  de Sitter spacetime

abstract:
  Gravitational waves are considered as metric perturbations about a curved
background metric, rather than the flat Minkowski metric since several
situations of physical interest can be discussed by this generalization. In
this case, when the de Donder gauge is imposed, its preservation under
infinitesimal spacetime diffeomorphisms is guaranteed if and only if the
associated covector is ruled by a second-order hyperbolic operator which is the
classical counterpart of the ghost operator in quantum gravity. In such a wave
equation, the Ricci term has opposite sign with respect to the wave equation
for Maxwell theory in the Lorenz gauge. We are, nevertheless, able to relate
the solutions of the two problems, and the algorithm is applied to the case
when the curved background geometry is the de Sitter spacetime. Such vector
wave equations are studied in two different ways: i) an integral
representation, ii) through a solution by factorization of the hyperbolic
equation. The latter method is extended to the wave equation of metric
perturbations in the de Sitter spacetime. This approach is a step towards a
general discussion of gravitational waves in the de Sitter spacetime and might
assume relevance in cosmology in order to study the stochastic background
emerging from inflation.


title: Localization of the relative phase via measurements

abstract:
  When two independently-prepared Bose-Einstein condensates are released from
their corresponding traps, the absorbtion image of the overlapping clouds
presents an interference pattern. Here we analyze a model introduced by
Javanainen and Yoo (J. Javanainen and S. M. Yoo, Phys. Rev. Lett. 76, 161
(1996)), who considered two atomic condensates described by plane waves
propagating in opposite directions. We present an analytical argument for the
measurement-induced breaking of the relative phase symmetry in this system,
demonstrating how the phase gets localized after a large enough number of
detection events.


title: Physical replicas and the Bose-glass in cold atomic gases

abstract:
  We study cold atomic gases in a disorder potential and analyze the
correlations between different systems subjected to the same disorder
landscape. Such independent copies with the same disorder landscape are known
as replicas. While in general these are not accessible experimentally in
condensed matter systems, they can be realized using standard tools for
controlling cold atomic gases in an optical lattice. Of special interest is the
overlap function which represents a natural order parameter for disordered
systems and is a correlation function between the atoms of two independent
replicas with the same disorder. We demonstrate an efficient measurement scheme
for the determination of this disorder-induced correlation function. As an
application, we focus on the disordered Bose-Hubbard model and determine the
overlap function within perturbation theory and a numerical analysis. We find
that the measurement of the overlap function allows for the identification of
the Bose-glass phase in certain parameter regimes.


title: Reanalysis of two eclipsing binaries: EE Aqr and Z Vul

abstract:
  We study the radial-velocity and light curves of the two eclipsing binaries
EE Aqr and Z Vul. Using the latest version of the Wilson & Van Hamme (2003)
model, absolute parameters for the systems are determined. We find that EE Aqr
and Z Vul are near-contact and semi-detached systems, respectively. The primary
component of EE Aqr fills about 96% of its 'Roche lobe', while its secondary
one appears close to completely filling this limiting volume. In a similar way,
we find fill-out proportions of about 72 and 100% of these volumes for the
primary and secondary components of Z Vul respectively. We compare our results
with those of previous authors.


title: A Liquid Film Motor

abstract:
  It is well known that electro-hydrodynamical effects in freely suspended
liquid films can flow the liquid. Here we report a purely electrically driven
rotation in water and some other liquid suspended films with full control on
the velocity and the chirality of the rotating vortices. The device, which is
called ``film motor'', consists of a quasi two-dimensional electrolysis cell in
an external in-plane electric field, crossing the mean electrolysis current
density. If either the external field or the electrolysis voltage exceeds some
threshold (while the other one is not zero), the liquid film begins to rotate.
The device works perfectly with both DC and AC fields.

categories: cond-mat.soft cond-mat.mtrl-sci physics.chem-ph physics.flu-dyn


title: Dynamical, dielectric, and elastic properties of GeTe

abstract:
  The dynamical, dielectric and elastic properties of GeTe, a ferroelectric
material in its low temperature rhombohedral phase, have been investigated
using first-principles density functional theory. We report the electronic
energy bands, phonon dispersion curves, electronic and low frequency dielectric
tensors, infra-red reflectivity, Born effective charges, elastic and
piezoelectric tensors and compare them with the existing theoretical and
experimental results, as well as with similar quantities available for other
ferroelectric materials, when appropriate.


title: Quotient categories, stability conditions, and birational geometry

abstract:
  This article deals with the quotient category of the category of coherent
sheaves on an irreducible smooth projective variety by the full subcategory of
sheaves supported in codimension greater than c. It turns out that this
category has homological dimension c. As an application of this, we will
describe the space of stability conditions on its derived category in the case
c=1. Moreover, we describe all exact equivalences between these quotient
categories in this particular case which is closely related to classification
problems in birational geometry.


title: No many-scallop theorem: Collective locomotion of reciprocal swimmers

abstract:
  To achieve propulsion at low Reynolds number, a swimmer must deform in a way
that is not invariant under time-reversal symmetry; this result is known as the
scallop theorem. We show here that there is no many-scallop theorem. We
demonstrate that two active particles undergoing reciprocal deformations can
swim collectively; moreover, polar particles also experience effective
long-range interactions. These results are derived for a minimal dimers model,
and generalized to more complex geometries on the basis of symmetry and scaling
arguments. We explain how such cooperative locomotion can be realized
experimentally by shaking a collection of soft particles with a homogeneous
external field.


title:
The relative concentration of visible and dark matter in clusters of
  galaxies

abstract:
  [Abridged] We consider two clusters (A496 and Coma) that are representative
of the two classes of cool-core and non-cool-core clusters. We first refer to a
two-component dynamical model that ignores the contribution from the galaxy
density distribution and study the condition of hydrostatic equilibrium for the
hot intracluster medium (ICM) under the assumption of spherical symmetry, in
the presence of dark matter. We model the ICM density distribution in terms of
a standard $\beta$-model with $\beta=2/3$, i.e. with a distribution similar to
that of a regular isothermal sphere (RIS), and fit the observed X-ray
brightness profiles. With the explicit purpose of ignoring cosmological
arguments, we na\"ively assume that dark matter, if present, has an analogous
density distribution, with the freedom of two different density and length
scales. The relative distribution of visible and dark matter is then derived by
fitting the temperature data for the ICM under conditions of hydrostatic
equilibrium. For both clusters, we find that dark matter is more concentrated
with respect to visible matter. We then test whether the conclusion changes
significantly when dark matter is taken to be distributed according to
cosmologically favored density profiles and when the contribution of the mass
contained in galaxies is taken into account. Although the qualitative
conclusions remain unchanged, we find that the contribution of galaxies to the
mass budget is more important than generally assumed. We also show that,
without resorting to additional information on the small scale, it is not
possible to tell whether a density cusp is present or absent in these systems.
[Abridged]


title:
Electron Optic Design of Arrayed E-Beam Microcolumns Based Systems for
  Wafer Defects Inspection

abstract:
  In this paper is considered a matter of the system for wafer defect
inspection (WDIS) practical realization. Such systems are on the agenda as the
next generation and substitution for light optics and single $e$-beam based
WDISs.


title:
INTEGRAL and Swift/XRT observations of the SFXT IGR J16479-4514: from
  quiescence to fast flaring activity

abstract:
  Context: IGR J16479-4514 is a fast X-ray transient known to display flares
lasting typically a few hours. Recently, its counterpart has been identified
with a supergiant star, therefore the source can be classified as member of the
newly discovered class of Supergiant Fast X-ray Transients (SFXTs),
specifically it is the one with the highest duty cycle. Aims: to characterize
the quiescent X-ray behaviour of the source and to compare its broad band
spectrum to that during fast X-ray flares. Methods: we performed an analysis of
IBIS and JEM-X data with OSA 5.1 as well as an analysis of archival Swift/XRT
data. Results: we present results from a long term monitoring of IGR
J16479-4514 with detailed spectral and timing informations on 19 bright fast
X-ray flares, 10 of which newly discovered. We also report for the first time
results on the quiescent X-ray emission; the typical luminosity value (about
10^34 erg s^-1) is about 2 orders of magnitude greater than that typical of
SFXTs while its broad band X-ray spectrum has a shape very similar to that
during fast X-ray transient activity, i.e. a rather steep power law with
Gamma=2.6. Conclusions: IGR J16479$-$4514 is characterized by a quiescent X-ray
luminosity higher than that typical of other known SFXTs but lower than
persistent emission from classical SGXBs. We suggest that such source is a kind
of transition object between these two systems, supporting the idea that there
is a continuum of behaviours between the class of SFXTs and that of classical
persistent SGXBs.


title: Measurement of the Mass Difference m(B0) - m(B+)

abstract:
  Using 230 million B Bbar events recorded with the BABAR detector at the e+ e-
storage rings PEP-II, we reconstruct approximately 4100 B0 to J/psi K+ pi- and
9930 B+ to J/psi K+ decays with J/psi to mu+ mu- and e+ e-. From the measured
B-momentum distributions in the e+ e- rest frame, we determine the mass
difference m(B0) - m(B+) = (+0.33 +- 0.05 +- 0.03) MeV/c^2.


title:
The Tractability of Model-Checking for LTL: The Good, the Bad, and the
  Ugly Fragments

abstract:
  In a seminal paper from 1985, Sistla and Clarke showed that the
model-checking problem for Linear Temporal Logic (LTL) is either NP-complete or
PSPACE-complete, depending on the set of temporal operators used. If, in
contrast, the set of propositional operators is restricted, the complexity may
decrease. This paper systematically studies the model-checking problem for LTL
formulae over restricted sets of propositional and temporal operators. For
almost all combinations of temporal and propositional operators, we determine
whether the model-checking problem is tractable (in P) or intractable
(NP-hard). We then focus on the tractable cases, showing that they all are
NL-complete or even logspace solvable. This leads to a surprising gap in
complexity between tractable and intractable cases. It is worth noting that our
analysis covers an infinite set of problems, since there are infinitely many
sets of propositional operators.


title:
The radiative decay of $\psi(3770)$ into the predicted scalar state
  X(3700)

abstract:
  We calculate the radiative decay width of the $\psi(3770)$ into the
dynamically generated scalar resonance X(3700) which is predicted in a previous
paper. The results show that it is possible that the upgraded BEPC-II facility
will generate enough statistics in order to observe this decay and thus confirm
the existence of the X(3700).


title:
Suzaku broad-band spectroscopy of RX J1347.5-1145: constraints on the
  extremely hot gas and non-thermal emission

abstract:
  We present the results from the analysis of long Suzaku observations of the
most X-ray luminous galaxy cluster RX J1347.5-1145 at z=0.451. Aims: We study
physical properties of the hot (~20 keV) gas clump in the south-east (SE)
region discovered by the Sunyaev-Zel'dovich (SZ) effect observations, to
understand the gas physics of a violent cluster merger. We also explore a
signature of non-thermal emission using the hard X-ray data. Results: We find
that the single-temperature model fails to reproduce the continuum emission and
Fe-K lines measured by XIS simultaneously. The two-temperature model with a
very hot component improves the fit, although the XIS data can only give a
lower bound on its temperature. We detect the hard X-ray emission in the 12-40
keV band at the 7 sigma level; however, the significance becomes marginal when
the systematic error in the background estimation is included. With the Suzaku
+ Chandra joint analysis, we determine the temperature of the SE excess
component to be 25.3^{+6.1}_{-4.5} ^{+6.9}_{-9.5} keV (90% statistical and
systematic errors), which is in an excellent agreement with the previous SZ +
X-ray analysis. This is the first time that the X-ray spectroscopy alone gives
a good measurement of the temperature of the hot component in the SE region,
which is made possible by Suzaku's unprecedented sensitivity to the wide X-ray
band. These results strongly indicate that the cluster has undergone a recent,
violent merger. The spectral analysis shows that the SE component is consistent
with being thermal. We find the 3 sigma upper limit on the non-thermal flux, F
< 8e-12 erg s^{-1} cm^{-2} in the 12-60 keV band. Combining this limit with a
recent discovery of the radio mini halo at 1.4 GHz, we find a lower limit on
the strength of the intracluster magnetic field, B > 0.007 micro G.


title:
Decoding Generalized Concatenated Codes Using Interleaved Reed-Solomon
  Codes

abstract:
  Generalized Concatenated codes are a code construction consisting of a number
of outer codes whose code symbols are protected by an inner code. As outer
codes, we assume the most frequently used Reed-Solomon codes; as inner code, we
assume some linear block code which can be decoded up to half its minimum
distance. Decoding up to half the minimum distance of Generalized Concatenated
codes is classically achieved by the Blokh-Zyablov-Dumer algorithm, which
iteratively decodes by first using the inner decoder to get an estimate of the
outer code words and then using an outer error/erasure decoder with a varying
number of erasures determined by a set of pre-calculated thresholds. In this
paper, a modified version of the Blokh-Zyablov-Dumer algorithm is proposed,
which exploits the fact that a number of outer Reed-Solomon codes with average
minimum distance d can be grouped into one single Interleaved Reed-Solomon code
which can be decoded beyond d/2. This allows to skip a number of decoding
iterations on the one hand and to reduce the complexity of each decoding
iteration significantly - while maintaining the decoding performance - on the
other.


title: Fermi's golden rule and exponential decay as a RG fixed point

abstract:
  We discuss the decay of unstable states into a quasicontinuum using models of
the effective Hamiltonian type. The goal is to show that exponential decay and
the golden rule are exact in a suitable scaling limit, and that there is an
associated renormalization group (RG) with these properties as a fixed point.
The method is inspired by a limit theorem for infinitely divisible
distributions in probability theory, where there is a RG with a Cauchy
distribution, i.e. a Lorentz line shape, as a fixed point. Our method of
solving for the spectrum is well known; it does not involve a perturbation
expansion in the interaction, and needs no assumption of a weak interaction. We
use random matrices for the interaction, and show that the ensemble
fluctuations vanish in the scaling limit. Thus the limit is the same for every
model in the ensemble with probability one.


title: Levy processes and Schroedinger equation

abstract:
  We analyze the extension of the well known relation between Brownian motion
and Schroedinger equation to the family of Levy processes. We consider a
Levy-Schroedinger equation where the usual kinetic energy operator - the
Laplacian - is generalized by means of a selfadjoint, pseudodifferential
operator whose symbol is the logarithmic characteristic of an infinitely
divisible law. The Levy-Khintchin formula shows then how to write down this
operator in an integro--differential form. When the underlying Levy process is
stable we recover as a particular case the fractional Schroedinger equation. A
few examples are finally given and we find that there are physically relevant
models (such as a form of the relativistic Schroedinger equation) that are in
the domain of the non-stable, Levy-Schroedinger equations.


title: Enhanced Zeeman splitting in Ga0.25In0.75As quantum point contacts

abstract:
  The strength of the Zeeman splitting induced by an applied magnetic field is
an important factor for the realization of spin-resolved transport in
mesoscopic devices. We measure the Zeeman splitting for a quantum point contact
etched into a Ga0.25In0.75As quantum well, with the field oriented parallel to
the transport direction. We observe an enhancement of the Lande g-factor from
|g*|=3.8 +/- 0.2 for the third subband to |g*|=5.8 +/- 0.6 for the first
subband, six times larger than in GaAs. We report subband spacings in excess of
10 meV, which facilitates quantum transport at higher temperatures.


title: Magnetoresistance of the heavy-fermion metal CeCoIn5

abstract:
  The magnetoresistance (MR) of CeCoIn5 is notably different from that expected
for orbital MR due to the Lorentz force and described by Kohler's rule which
holds in many conventional metals. We show that a pronounced crossover from
negative to positive MR of CeCoIn5 that occurs at elevated temperatures is
determined by the dependence of the effective mass M*(B,T) on both magnetic
field B and temperature T. Thus, the crossover is regulated by the universal
behavior of M*(B,T) observed in heavy-fermion metals. This behavior is
exhibited by M*(B,T) when a strongly correlated electron system transits from
the Landau Fermi liquid behavior induced by the application of magnetic field
to the non-Fermi liquid behavior taking place at rising temperatures. Our
calculations of MR are in good agreement with facts and reveal new scaling
behavior of MR.


title: Size dependent motion of nanodroplets on chemical steps

abstract:
  Nanodroplets on chemically structured substrates move under the action of
disjoining pressure induced forces. A detailed analysis of them shows that even
in the absence of long-ranged lateral variations of the effective interface
potential, already the fact, that due their small size nano-droplets do not
sample the disjoining pressure at all distances from the substrate, can lead to
droplet motion towards the less wettable part of the substrate, i.e., in the
direction opposite to the one expected on the basis of macroscopic wettability
considerations.


title: Spread Codes and Spread Decoding in Network Coding

abstract:
  In this paper we introduce the class of Spread Codes for the use in random
network coding. Spread Codes are based on the construction of spreads in finite
projective geometry. The major contribution of the paper is an efficient
decoding algorithm of spread codes up to half the minimum distance.


title: On the genealogy of the Orphan Stream

abstract:
  We use N-body simulations to explore the origin and a plausible orbit for the
Orphan Stream, one of the faintest substructures discovered so far in the outer
halo of our Galaxy. We are able to reproduce its position, velocity and
distance measurements by appealing to a single wrap of a double-component
satellite galaxy. We find that the progenitor of the Orphan Stream could have
been an object similar to today's Milky Way dwarfs, such as Carina, Draco, Leo
II or Sculptor; and unlikely to be connected to Complex A or Ursa Major II. Our
models suggest that such progenitors, if accreted on orbits with apocenters
smaller than ~35 kpc, are likely to give rise to very low surface brightness
streams, which may be hiding in the outer halo and remain largely undetected
with current techniques. The systematic discovery of these ghostly
substructures may well require wide field spectroscopic surveys of the Milky
Way's outer stellar halo.


title: Degrees of maps between Grassmann manifolds

abstract:
  Let $f:G_{n,k}\longrightarrow G_{m,l}$ be any continuous map between any two
distinct complex Grassmann manifolds of the same dimension where the target is
not the complex projective space. We show that, for any given $k,l$, the degree
of $f$ is zero provided that $m,n$ are sufficiently large. If the degree of $f$
is $\pm 1$, we show that $(m,l)=(n,k)$ and $f$ is a homotopy equivalence. Also,
we prove that the image under $f^*$ of elements of a set of algebra generators
of $H^*(G_{m,l};\mathbb{Q})$ is determined upto a sign, $\pm$, if the degree of
$f$ is non-zero. Our proofs cover the case of quaternionic Grassmann manifolds
as well.


title: Iterative Hard Thresholding for Compressed Sensing

abstract:
  Compressed sensing is a technique to sample compressible signals below the
Nyquist rate, whilst still allowing near optimal reconstruction of the signal.
In this paper we present a theoretical analysis of the iterative hard
thresholding algorithm when applied to the compressed sensing recovery problem.
We show that the algorithm has the following properties (made more precise in
the main text of the paper)
  - It gives near-optimal error guarantees.
  - It is robust to observation noise.
  - It succeeds with a minimum number of observations.
  - It can be used with any sampling operator for which the operator and its
adjoint can be computed.
  - The memory requirement is linear in the problem size.
  - Its computational complexity per iteration is of the same order as the
application of the measurement operator or its adjoint.
  - It requires a fixed number of iterations depending only on the logarithm of
a form of signal to noise ratio of the signal.
  - Its performance guarantees are uniform in that they only depend on
properties of the sampling operator and signal sparsity.


title: Raman spectra of misoriented bilayer graphene

abstract:
  We compare the main feature of the measured Raman scattering spectra from
single layer graphene with a bilayer in which the two layers are arbitrarily
misoriented. The profiles of the 2D bands are very similar having only one
component, contrary to the four found for commensurate Bernal bilayers. These
results agree with recent theoretical calculations and point to the similarity
of the electronic structures of single layer graphene and misoriented bilayer
graphene. Another new aspect is that the dependance of the 2D frequency on the
laser excitation energy is different in these two latter systems.


title:
A comparative study of social network models: network evolution models
  and nodal attribute models

abstract:
  This paper reviews, classifies and compares recent models for social networks
that have mainly been published within the physics-oriented complex networks
literature. The models fall into two categories: those in which the addition of
new links is dependent on the (typically local) network structure (network
evolution models, NEMs), and those in which links are generated based only on
nodal attributes (nodal attribute models, NAMs). An exponential random graph
model (ERGM) with structural dependencies is included for comparison. We fit
models from each of these categories to two empirical acquaintance networks
with respect to basic network properties. We compare higher order structures in
the resulting networks with those in the data, with the aim of determining
which models produce the most realistic network structure with respect to
degree distributions, assortativity, clustering spectra, geodesic path
distributions, and community structure (subgroups with dense internal
connections). We find that the nodal attribute models successfully produce
assortative networks and very clear community structure. However, they generate
unrealistic clustering spectra and peaked degree distributions that do not
match empirical data on large social networks. On the other hand, many of the
network evolution models produce degree distributions and clustering spectra
that agree more closely with data. They also generate assortative networks and
community structure, although often not to the same extent as in the data. The
ERG model turns out to produce the weakest community structure.


title:
Reply to Melott's Comment on ``Discreteness Effects in Lambda Cold Dark
  Matter Simulations: A Wavelet-Statistical View'' by Romeo et al

abstract:
  Melott has made pioneering studies of the effects of particle discreteness in
N-body simulations, a fundamental point that needs careful thought and analysis
since all such simulations suffer from numerical noise arising from the use of
finite-mass particles. Melott (arXiv:0804.0589) claims that the conclusions of
our paper (arXiv:0804.0294) are essentially equivalent to those of his earlier
work. Melott is wrong: he has jumped onto one of our conclusions and
interpreted that in his own way. Here we point out the whys and the wherefores.


title: Efficient recovering of operation tables of black box groups and rings

abstract:
  People have been studying the following problem: Given a finite set S with a
hidden (black box) binary operation * on S which might come from a group law,
and suppose you have access to an oracle that you can ask for the operation x*y
of single pairs (x,y) you choose. What is the minimal number of queries to the
oracle until the whole binary operation is recovered, i.e. you know x*y for all
x,y in S?
  This problem can trivially be solved by using |S|^2 queries to the oracle, so
the question arises under which circumstances you can succeed with a
significantly smaller number of queries.
  In this presentation we give a lower bound on the number of queries needed
for general binary operations. On the other hand, we present algorithms solving
this problem by using |S| queries, provided that * is an abelian group
operation. We also investigate black box rings and give lower and upper bounds
for the number of queries needed to solve product recovering in this case.


title:
Interplay of metamagnetic and structural transitions in
  Ca$_{2-x}$Sr$_x$RuO$_4$

abstract:
  Metamagnetism in layered ruthenates has been interpreted as a novel kind of
quantum critical behavior. In an external magnetic field,
Ca$_{2-x}$Sr$_x$RuO$_4$ undergoes a metamagnetic transition accompanied by a
pronounced magnetostriction effect. In this paper we present a mean-field study
for a microscopic model that naturally reproduces the key features of this
system. The phase diagram calculated is equivalent to the experimental $T$-$x$
phase diagram. The presented model also gives a good basis to discuss the
critical metamagnetic behavior measured in the system.


title: The Gaussian MAC with Conferencing Encoders

abstract:
  We derive the capacity region of the Gaussian version of Willems's two-user
MAC with conferencing encoders. This setting differs from the classical MAC in
that, prior to each transmission block, the two transmitters can communicate
with each other over noise-free bit-pipes of given capacities. The derivation
requires a new technique for proving the optimality of Gaussian input
distributions in certain mutual information maximizations under a Markov
constraint. We also consider a Costa-type extension of the Gaussian MAC with
conferencing encoders. In this extension, the channel can be described as a
two-user MAC with Gaussian noise and Gaussian interference where the
interference is known non-causally to the encoders but not to the decoder. We
show that as in Costa's setting the interference sequence can be perfectly
canceled, i.e., that the capacity region without interference can be achieved.


title:
Analysis of the Deterministic Polynomial Time Solvability of the
  0-1-Knapsack Problem

abstract:
  Previously the author has demonstrated that a representative polynomial
search partition is required to solve a NP-complete problem in deterministic
polynomial time. It has also been demonstrated that finding such a partition
can only be done in deterministic polynomial time if the form of the problem
provides a simple method for producing the partition. It is the purpose of this
article to demonstrate that no deterministic polynomial time method exists to
produce a representative polynomial search partition for the Knapsack problem.


title: Magnetoelectric oscillations in quasi-2D ferrite disk particles

abstract:
  In this paper we show that magnetic-dipolar-mode (MDM) oscillations of a
quasi-2D ferrite disk are characterized by unique symmetry features with
topological phases resulting in appearance of the magnetoelectric (ME)
properties. The entire ferrite disk can be characterized as a pair of two,
electric and magnetic, coupled eigen moments. However, there is no a "glued
pair" of two dipoles. An external electromagnetic field in the near-field
region "views" such a ME particle, as a system with a normally oriented eigen
electric moment and an in-plane rotating eigen magnetic dipole moment.


title:
Classical and Quantum Gravitational Collapse in d-dim AdS Spacetime II.
  Quantum States and Hawking Radiation

abstract:
  In a previous paper we studied the collapse of a spherically symmetric dust
distribution (marginally bound LTB) in d-dimensional AdS spacetime and obtained
the condition for the formation of trapped surfaces. Here we extend the
analysis by giving the canonical theory for the same and subsequently quantize
the system by solving the Wheeler-DeWitt equation. We show that for the case of
small dust perturbations around a black hole the wave functionals so obtained
describe an AdS-Schwarzschild black hole in equilibrium with a thermal bath at
Hawking temperature and show the non-trivial dependence of this temperature on
the number of spacetime dimensions and the cosmological constant.


title: The Radial Wave Operator in Similarity Coordinates

abstract:
  We present a rigorous functional analytic setting to study the radial wave
equation in similarity coordinates. As an application we analyse linear
stability of the fundamental self--similar solution of the wave equation with a
focusing power nonlinearity.


title: On the Capacity of Free-Space Optical Intensity Channels

abstract:
  New upper and lower bounds are presented on the capacity of the free-space
optical intensity channel. This channel is characterized by inputs that are
nonnegative (representing the transmitted optical intensity) and by outputs
that are corrupted by additive white Gaussian noise (because in free space the
disturbances arise from many independent sources). Due to battery and safety
reasons the inputs are simultaneously constrained in both their average and
peak power. For a fixed ratio of the average power to the peak power the
difference between the upper and the lower bounds tends to zero as the average
power tends to infinity, and the ratio of the upper and lower bounds tends to
one as the average power tends to zero. The case where only an average-power
constraint is imposed on the input is treated separately. In this case, the
difference of the upper and lower bound tends to 0 as the average power tends
to infinity, and their ratio tends to a constant as the power tends to zero.


title: Notes on algebra and geometry of polynomial representations

abstract:
  Consider a semi-algebraic set A in R^d constructed from the sets which are
determined by inequalities p_i(x)>0, p_i(x)\ge 0, or p_i(x)=0 for a given list
of polynomials p_1,...,p_m. We prove several statements that fit into the
following template. Assume that in a neighborhood of a boundary point the
semi-algebraic set A can be described by an irreducible polynomial f. Then f is
a factor of a certain multiplicity of some of the polynomials p_1,...,p_m.
Special cases when A is elementary closed, elementary open, a polygon, or a
polytope are considered separately.


title: Initial-state randomness as a universal source of decoherence

abstract:
  We study time evolution of entanglement between two qubits, which are part of
a larger system, after starting from a random initial product state. We show
that, due to randomness in the initial product state, entanglement is present
only between directly coupled qubits and only for short times. Time dependence
of the entanglement appears essentially independent of the specific hamiltonian
used for time evolution and is well reproduced by a parameter-free two-body
random matrix model.


title:
On non-vanishing of cohomologies of generalized Raynaud polarized
  surfaces

abstract:
  We consider a family of slightly extended version of the Raynaud's surfaces X
over the field of positive characteristic with Mumford-Szpiro type
polarizations Z, which have Kodaira non-vanishing H^1(X, Z^{-1})\ne 0. The
surfaces are at least normal but smooth under a special condition. We compute
the cohomologies H^i(X, Z^n), for intergers i and n, and study their
(non-)vanishing. Finally, we give a fairly large family of non Mumford-Szpiro
type polarizations Z_{a,b} with Kodaira non-vanishing.


title:
Study of Micro Pixel Photon Counter for the Application to Positron
  Emission Tomography

abstract:
  The main challenges posed by the design of future Positron Emission
Tomography machines are the improvement of the spatial and timing resolution
and the combined operation with magnetic resonance. The Micro Pixel Photon
Counter by Hamamatsu is a good candidate for this application. Its small size
(down to 1 mm2) and the high photo-detection efficiency in the blue spectral
region allow the direct readout of a highly segmented scintillator matrix
improving the spatial resolution of the machine. Furthermore, this
photo-detector is insensitive to static magnetic fields up to 5 T, which makes
it a possible candidate for applications in a magnetic resonance environment,
though tests in a fast changing gradient field need still to be performed.
  The aim of this study is the characterization of a system composed by a
scintillator crystal readout via a MPPC. Crystals of 1x1x15 mm3 and 3x3x15 mm3
are directly coupled to a MPPC of the same size active area and the energy
resolution at 511 keV is measured. The coincidence time resolution of two so
assembled detector units is measured. A first comparison of the performances of
LSO and LFS crystals is given.