title:
Radiative decays with light scalar mesons and singlet-octet mixing in
  ChPT

abstract:
  We study different types of radiative decays involving f0(980) and a0(980)
mesons within a unified ChPT-based approach at one-loop level. Light scalar
resonances which are seen in pi pi, pi eta, K K-bar channels of phi(1020)
radiative decays and in J/psi decays are responsible for key questions of
low-energy dynamics in the strong interaction sector, and decays phi(1020) ->
gamma a0(980), phi(1020) -> gamma f0(980), a0(980) -> gamma gamma, f0(980) ->
gamma gamma are of interest for current experimental programs in Juelich,
Frascati and Novosibirsk. From theoretical point of view it is important to
verify whether light scalar mesons are members of some flavor octet or nonet.
We find a value of mixing angle dictated by consistency with experiment and
coupling structures of ChPT Lagrangian. Decay widths f0(980)/a0(980) -> gamma
rho(770)/omega(782), which are not studied experimentally yet, are predicted.
We also obtain several relations between widths, which hold independently of
coupling constants and represent a fingerprint of the model.


title: A fixed point iteration for computing the matrix logarithm

abstract:
  In various areas of applied numerics, the problem of calculating the
logarithm of a matrix A emerges. Since series expansions of the logarithm
usually do not converge well for matrices far away from the identity, the
standard numerical method calculates successive square roots. In this article,
a new algorithm is presented that relies on the computation of successive
matrix exponentials. Convergence of the method is demonstrated for a large
class of initial matrices and favorable choices of the initial matrix are
discussed.


title:
VISIR/VLT mid-infrared imaging of Seyfert nuclei: Nuclear dust emission
  and the Seyfert-2 dichotomy

abstract:
  Half of the Seyfert-2 galaxies escaped detection of broad lines in their
polarised spectra observed so far. Some authors have suspected that these
non-HBLRs contain real Sy2 nuclei without intrinsic broad line region hidden
behind a dust torus. If this were true, then their nuclear structure would
fundamentally differ from that of Sy2s with polarised broad lines: in
particular, they would not be explained by orientation-based AGN unification.
Further arguments for two physically different Sy2 populations have been
derived from the warm and cool IRAS F25/F60 ratios. These ratios, however,
refer to the entire host galaxies and are unsuitable to conclusively establish
the absence of a nuclear dust torus. Instead, a study of the Seyfert-2
dichotomy should be performed on the basis of nuclear properties only. Here we
present the first comparison between [OIII] 5007A and mid-infrared imaging at
matching spatial resolution. Exploring the Seyfert-2 dichotomy we find that the
distributions of nuclear mid-infrared/[OIII] luminosity ratios are
indistinguishable for Sy1s and Sy2s with and without detected polarised broad
lines and irrespective of having warm or cool IRAS F25/F60 ratios. We find no
evidence for the existence of a population of real Sy2s with a deficit of
nuclear dust emission. Our results suggest 1) that all Seyfert nuclei possess
the same physical structure including the putative dust torus and 2) that the
cool IRAS colours are caused by a low contrast of AGN to host galaxy. Then the
Seyfert-2 dichotomy is explained in part by unification of non-HBLRs with
narrow-line Sy1s and to a larger rate by observational biases caused by a low
AGN/host contrast and/or an unfavourable scattering geometry.


title:
Electric Polarization Induced by a Proper Helical Magnetic Ordering in a
  Delafossite Multiferroic CuFe1-xAlxO2

abstract:
  Multiferroic CuFe1-xAlxO2 (x=0.02) exhibits a ferroelectric ordering
accompanied by a proper helical magnetic ordering below T=7K under zero
magnetic field. By polarized neutron diffraction and pyroelectric measurements,
we have revealed a one-to-one correspondence between the spin helicity and the
direction of the spontaneous electric polarization. This result indicates that
the spin helicity of the proper helical magnetic ordering is essential for the
ferroelectricity in CuFe1-xAlxO2. The induction of the electric polarization by
the proper helical magnetic ordering is, however, cannot be explained by the
Katsura-Nagaosa-Balatsky model, which successfully explains the
ferroelectricity in the recently explored ferroelectric helimagnets, such as
TbMnO3. We thus conclude that CuFe1-xAlxO2 is a new class of magnetic
ferroelectrics.


title:
Determination of the Mott insulating transition by the multi-reference
  density functional theory

abstract:
  It is shown that a momentum-boost technique applied to the extended Kohn-Sham
scheme enables the computational determination of the Mott insulating
transition. Self-consistent solutions are given for correlated electron systems
by the first-principles calculation defined by the multi-reference density
functional theory, in which the effective short-range interaction can be
determined by the fluctuation reference method. An extension of the Harriman
construction is made for the twisted boundary condition in order to define the
momentum-boost technique in the first-principles manner. For an effectively
half-filled-band system, the momentum-boost method tells that the period of a
metallic ground state by the LDA calculation is shortened to the least period
of the insulating phase, indicating occurrence of the Mott insulating
transition.


title:
A self-consistent first-principles calculation scheme for correlated
  electron systems

abstract:
  A self-consistent calculation scheme for correlated electron systems is
created based on the density-functional theory (DFT). Our scheme is a
multi-reference DFT (MR-DFT) calculation in which the electron charge density
is reproduced by an auxiliary interacting Fermion system. A short-range
Hubbard-type interaction is introduced by a rigorous manner with a residual
term for the exchange-correlation energy. The Hubbard term is determined
uniquely by referencing the density fluctuation at a selected localized
orbital. This strategy to obtain an extension of the Kohn-Sham scheme provides
a self-consistent electronic structure calculation for the materials design.
Introducing an approximation for the residual exchange-correlation energy
functional, we have the LDA+U energy functional. Practical self-consistent
calculations are exemplified by simulations of Hydrogen systems, i.e. a
molecule and a periodic one-dimensional array, which is a proof of existence of
the interaction strength U as a continuous function of the local fluctuation
and structural parameters of the system.


title: A weak dichotomy below E_1 \times E_3

abstract:
  If E is an equivalence relation Borel reducible to E_1 \times E_3 then either
E is Borel reducible to the equality of countable sets of reals or E_1 is Borel
reducible to E. The "either" case admits further strengthening.


title:
A superadditivity and submultiplicativity property for cardinalities of
  sumsets

abstract:
  For finite sets of integers $A_1, A_2 ... A_n$ we study the cardinality of
the $n$-fold sumset $A_1+...
  +A_n$ compared to those of $n-1$-fold sumsets $A_1+...
  +A_{i-1}+A_{i+1}+... A_n$. We prove a superadditivity and a
submultiplicativity property for these quantities. We also examine the case
when the addition of elements is restricted to an addition graph between the
sets.


title: On the self-adjointness of certain reduced Laplace-Beltrami operators

abstract:
  The self-adjointness of the reduced Hamiltonian operators arising from the
Laplace-Beltrami operator of a complete Riemannian manifold through quantum
Hamiltonian reduction based on a compact isometry group is studied. A simple
sufficient condition is provided that guarantees the inheritance of essential
self-adjointness onto a certain class of restricted operators and allows us to
conclude the self-adjointness of the reduced Laplace-Beltrami operators in a
concise way. As a consequence, the self-adjointness of spin Calogero-Sutherland
type reductions of `free' Hamiltonians under polar actions of compact Lie
groups follows immediately.


title:
Measuring the Momentum of a Nanomechanical Oscillator through the Use of
  Two Tunnel Junctions

abstract:
  We propose a way to measure the momentum p of a nanomechanical oscillator.
The p-detector is based on two tunnel junctions in a Aharonov-Bohm-type setup.
One of the tunneling amplitudes depends on the motion of the oscillator, the
other one not. Although the coupling between the detector and the oscillator is
assumed to be linear in the position x of the oscillator, it turns out that the
finite-frequency noise output of the detector will in general contain a term
proportional to the momentum spectrum of the oscillator. This is a true quantum
phenomenon, which can be realized in practice if the phase of the tunneling
amplitude of the detector is tuned by the Aharonov-Bohm flux Phi to a
p-sensitive value.


title: Local cloning of genuine entangled states of three qubit

abstract:
  We discuss (im)possibility of the exact cloning of orthogonal but genuinely
entangled three qubit states aided with entangled ancila under local operation
and classical communication. Whereas any two orthogonal GHZ states taken from
the canonical GHZ basis, can be cloned with the help of a known GHZ state,
surprisingly we find that no two W states can be cloned by using any known
three qubit (possibly entangled) state as blank copy.


title: Transport properties of chemically synthesized polypyrrole thin films

abstract:
  The electronic transport in polypyrrole thin films synthesized chemically
from the vapor phase is studied as a function of temperature as well as of
electric and magnetic fields. We find distinct differences in comparison to the
behavior of both polypyrrole films prepared by electrochemical growth as well
as of the bulk films obtained from conventional chemical synthesis. For small
electric fields F, a transition from Efros-Shklovskii variable range hopping to
Arrhenius activated transport is observed at 30 K. High electric fields induce
short range hopping. The characteristic hopping distance is found to be
proportional to F^(-1/2). The magnetoresistance R(B) is independent of F below
a critical magnetic field, above which F counteracts the magnetic field induced
localization.


title: Metastable Vacua and Complex Deformations

abstract:
  We use the non-normalizable complex deformations to describe the stringy
realizations of the metastable vacua in N = 1, SU(N_c) SUSY theories with N_f >
N_c massive fundamental flavors. The consideration of the non-normalizable
deformations requires a modified Toric duality. The new approach considers the
tachyon condensation between pairs of wrapped D5 branes and anti D5 branes and
the resulting mixing between some cycles in the geometry. We enlarge the class
of metastable vacua to the case of branes-antibranes wrapped on cycles of
deformed A_n singularities.


title: Normal versus inverted hierarchical models within $\mu-\tau$ symmetry

abstract:
  We make a theoretical attempt to compare the predictions from normal and
inverted hierarchical models, within the framework of $\mu-\tau$ symmetry. We
consider three major theoretical issues in a self consistent ways, viz.,
predictions on neutrino mass and mixing parameters, stability under RG analysis
in MSSM, and baryogenesis through leptogenesis. We further extend our earlier
works on parametrisation of neutrino mass matrices using only two parameters,
in addition to an overall mass scale $m_0$, and the ratio of these two
parameters fixes the value of solar mixing angle. Such parametrisation though
phenomenological gives a firm handle on the analysis of the mass matrices and
predicts lower values of solar mixing angle in the range
$\tan^2\theta_{12}=0.50-0.35$.We check the stability of the model under
radiative corrections in MSSM for large $\tan\beta\sim 58-60$ region and
observe that the evolution of $\bigtriangleup m^2_{21}$ with energy scale, is
highly dependent on the input high scale value of solar mixing angle. Solar
angle predicted by tri-bimaximal mixings and also values lower than this, do
not lead to stability of the model. Similarly, the evolution of the atmospheric
mixing angle with energy scale at large $\tan\beta$ values, shows sharp
decrease for the case with non-zero value of m_3. We apply these mass matrices
to estimate the baryon asymmetry of the universe in a self consistent way and
find that normal hierarchical model leads to the best result. Considering all
these three pieces of theoretical investigations, we may conclude that normal
hierarchical model is more favourable in nature.


title:
Time Dependent Local Field Distribution and Metastable States in the
  SK-Spin-Glass

abstract:
  Different sets of metastable states can be reached in glassy systems below
some transition temperature depending on initial conditions and details of the
dynamics. This is investigated for the Sherrington-Kirkpatrick spin glass model
with long ranged interactions. In particular, the time dependent local field
distribution and energy are calculated for zero temperature. This is done for a
system quenched to zero temperature, slow cooling or simulated annealing, a
greedy algorithm and repeated tapping. Results are obtained from Monte-Carlo
simulations and a Master-Fokker-Planck approach. A comparison with replica
symmetry broken theory, evaluated in high orders, shows that the energies
obtained via dynamics are higher than the ground state energy of replica
theory. Tapping and simulated annealing yield on the other hand results which
are very close to the ground state energy. The local field distribution tends
to zero for small fields. This is in contrast to the Edwards flat measure
hypothesis. The distribution of energies obtained for different tapping
strengths does again not follow the canonical form proposed by Edwards.


title:
Condensation of Ideal Bose Gas Confined in a Box Within a Canonical
  Ensemble

abstract:
  We set up recursion relations for the partition function and the ground-state
occupancy for a fixed number of non-interacting bosons confined in a square box
potential and determine the temperature dependence of the specific heat and the
particle number in the ground state. A proper semiclassical treatment is set up
which yields the correct small-T-behavior in contrast to an earlier theory in
Feynman's textbook on Statistical Mechanics, in which the special role of the
ground state was ignored. The results are compared with an exact quantum
mechanical treatment. Furthermore, we derive the finite-size effect of the
system.


title:
High-Frequency Oscillations in a Solar Active Region observed with the
  Rapid Dual Imager

abstract:
  High-cadence, synchronized, multiwavelength optical observations of a solar
active region (NOAA 10794) are presented. The data were obtained with the Dunn
Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly
developed camera system : the Rapid Dual Imager. Wavelet analysis is undertaken
to search for intensity related oscillatory signatures, and periodicities
ranging from 20 to 370 s are found with significance levels exceeding 95%.
Observations in the H-alpha blue wing show more penumbral oscillatory phenomena
when compared to simultaneous G-band observations. The H-alpha oscillations are
interpreted as the signatures of plasma motions with a mean velocity of 20
km/s. The strong oscillatory power over H-alpha blue-wing and G-band penumbral
bright grains is an indication of the Evershed flow with frequencies higher
than previously reported.


title:
Lagrangians with electric and magnetic charges of N=2 supersymmetric
  gauge theories

abstract:
  General Lagrangians are constructed for N=2 supersymmetric gauge theories in
four space-time dimensions involving gauge groups with (non-abelian) electric
and magnetic charges. The charges induce a scalar potential, which, when the
charges are regarded as spurionic quantities, is invariant under
electric/magnetic duality. The resulting theories are especially relevant for
supergravity, but details of the extension to local supersymmetry will be
discussed elsewhere. The results include the coupling to hypermultiplets.
Without the latter, it is demonstrated how an off-shell representation can be
constructed based on vector and tensor supermultiplets.


title:
Animation of virtual mannequins, robot-like simulation or motion
  captures

abstract:
  In order to optimize the costs and time of design of the new products while
improving their quality, concurrent engineering is based on the digital model
of these products, the numerical model. However, in order to be able to avoid
definitively physical model, old support of the design, without loss of
information, new tools must be available. Especially, a tool making it possible
to check simply and quickly the maintainability of complex mechanical sets
using the numerical model is necessary. Since one decade, our team works on the
creation of tool for the generation and the analysis of trajectories of virtual
mannequins. The simulation of human tasks can be carried out either by
robot-like simulation or by simulation by motion capture. This paper presents
some results on the both two methods. The first method is based on a
multi-agent system and on a digital mock-up technology, to assess an efficient
path planner for a manikin or a robot for access and visibility task taking
into account ergonomic constraints or joint and mechanical limits. In order to
solve this problem, the human operator is integrated in the process
optimization to contribute to a global perception of the environment. This
operator cooperates, in real-time, with several automatic local elementary
agents. In the case of the second approach, we worked with the CEA and EADS/CCR
to solve the constraints related to the evolution of human virtual in its
environment on the basis of data resulting from motion capture system. An
approach using of the virtual guides was developed to allow to the user the
realization of precise trajectory in absence of force feedback. The result of
this work validates solutions through the digital mock-up; it can be applied to
simulate maintenability and mountability tasks.


title:
Bulk Filling Branes and the Baryon Density in AdS/QCD with gravity
  back-reaction

abstract:
  We consider the gravity back reaction on the metric due to the baryon density
in effective ads/qcd model by reconsidering the role of the charged AdS black
hole. Previously it has been known that the U(1) charge is dual to the
R-charge. Here we point out that if we consider the case where $AdS_5$ is
completely filled with $N_f$ flavor branes, the gravity back reaction produces
charged AdS black hole where the effect of charge on the metric is proportional
to $N_f/N_c$. As a consequence, phase diagram changes qualitatively if we allow
$N_f/N_c$ finite: it closes at the finite density unlike the probe brane
embedding approach.
  Another issue we discuss here is the question whether there is any chemical
potential dependence in the confining phase. We consider this problem in the
hard wall model with baryon charge. We conclude that there is a non-trivial
dependence on the chemical potential in this case also.


title:
Screening effects on field emission from arrays of (5,5) carbon
  nanotubes: Quantum-mechanical simulation

abstract:
  The simulation of field electron emission from arrays of micrometer-long
open-ended (5, 5) carbon nanotubes is performed in the framework of quantum
theory of many electrons. It is found that the applied external field is
strongly screened when the spacing distance is shorter than the length of the
carbon nanotubes. The optimal spacing distance is two to three times of the
nanotube length, slightly depending on the applied external fields. The
electric screening can be described by a factor that is a exponential function
of the ratio of the spacing distance to the length of the carbon nanotubes. For
a given length, the field enhancement factor decreases sharply as the screening
factor larger than 0.05. The simulation implies that the thickness of the array
should be larger than a value but it does not help the emission much by
increasing the thickness a great deal.


title:
A Framework to Illustrate Kinematic Behavior of Mechanisms by Haptic
  Feedback

abstract:
  The kinematic properties of mechanisms are well known by the researchers and
teachers. The theory based on the study of Jacobian matrices allows us to
explain, for example, the singular configuration. However, in many cases, the
physical sense of such properties is difficult to explain to students. The aim
of this article is to use haptic feedback to render to the user the
signification of different kinematic indices. The framework uses a Phantom Omni
and a serial and parallel mechanism with two degrees of freedom. The
end-effector of both mechanisms can be moved either by classical mouse, or
Phantom Omni with or without feedback.


title: A remark on global well-posedness below L^2 for the gKdV-3 equation

abstract:
  The I-method in its first version as developed by Colliander et al. is
applied to prove that the Cauchy-problem for the generalised Korteweg-de Vries
equation of order three (gKdV-3) is globally well-posed for large real-valued
data in the Sobolev space H^s, provided s>-1/42.


title: Nonlinear SDEs driven by L\'evy processes and related PDEs

abstract:
  In this paper we study general nonlinear stochastic differential equations,
where the usual Brownian motion is replaced by a L\'evy process. We also
suppose that the coefficient multiplying the increments of this process is
merely Lipschitz continuous and not necessarily linear in the time-marginals of
the solution as is the case in the classical McKean-Vlasov model. We first
study existence, uniqueness and particle approximations for these stochastic
differential equations. When the driving process is a pure jump L\'evy process
with a smooth but unbounded L\'evy measure, we develop a stochastic calculus of
variations to prove that the time-marginals of the solutions are absolutely
continuous with respect to the Lebesgue measure. In the case of a symmetric
stable driving process, we deduce the existence of a function solution to a
nonlinear integro-differential equation involving the fractional Laplacian.


title: Recent Results from HERA Experiments

abstract:
  Recent results from HERA are presented. The main reviewed subjects are
polarized DIS cross sections, parton density determination, diffractive PDFs,
multi-jet production and searches for physics beyond the Standard Model.


title: Fluctuation Relations for Diffusion Processes

abstract:
  The paper presents a unified approach to different fluctuation relations for
classical nonequilibrium dynamics described by diffusion processes. Such
relations compare the statistics of fluctuations of the entropy production or
work in the original process to the similar statistics in the time-reversed
process. The origin of a variety of fluctuation relations is traced to the use
of different time reversals. It is also shown how the application of the
presented approach to the tangent process describing the joint evolution of
infinitesimally close trajectories of the original process leads to a
multiplicative extension of the fluctuation relations.


title:
Quantum Dynamics of the Taub Universe in a Generalized Uncertainty
  Principle framework

abstract:
  The implications of a Generalized Uncertainty Principle on the Taub
cosmological model are investigated. The model is studied in the ADM reduction
of the dynamics and therefore a time variable is ruled out. Such a variable is
quantized in a canonical way and the only physical degree of freedom of the
system (related to the Universe anisotropy) is quantized by means of a modified
Heisenberg algebra. The analysis is performed at both classical and quantum
level. In particular, at quantum level, the motion of wave packets is
investigated. The two main results obtained are as follows. i) The classical
singularity is probabilistically suppressed. The Universe exhibits a stationary
behavior and the probability amplitude is peaked in a determinate region. ii)
The GUP wave packets provide the right behavior in the establishment of a
quasi-isotropic configuration for the Universe.


title: Linear effects of perturbed recombination

abstract:
  Perturbations in the ionization fraction after recombination affect the
Compton cooling of density perturbations. Once the gas temperature starts to
decouple from the CMB temperature, ionization fraction perturbations can have a
significant influence on the subsequent gas temperature perturbation evolution.
This directly affects the 21cm spin temperature of the gas, and also modifies
the small-scale baryon perturbation evolution via the difference in baryon
pressure. The effect on the gas temperature perturbations can be significant on
all scales, and galactic-scale baryon perturbations are modified at the percent
level at redshifts z >~ 100 where numerical simulations are typically started.


title: Prolate Spheroidal Wave Functions In q-Fourier Analysis

abstract:
  The prolate spheroidal wave functions, which are a special case of the
spheroidal wave functions, possess a very surprising and unique property [6].
They are an orthogonal basis of both $L^2(-1,1)$ and the Paley-Wiener space of
bandlimited functions. They also satisfy a discrete orthogonality relation. No
other system of classical orthogonal functions is known to possess this strange
property. We prove that there are new systems possessing this property in
$q$-Fourier analysis. As application we give a new sampling formula with $q^n$
as sampling points, where 0 < q < 1.


title: q-Sturm-Liouville theory and the corresponding eigenfunction expansions

abstract:
  The aim of this paper is to study the $q$-Schr\"{o}dinger operator $$ L=
q(x)-\Delta_q, $$ where $q(x)$ is a given function of $x$ defined over
$\mathbb{R}_{q}^{+}=\{q^n,\quad n\in\mathbb Z\}$ and $\Delta_q$ is the
$q$-Laplace operator $$ \Delta_{q}f(x)=\frac{1}{x^{2}}[
f(q^{-1}x)-\frac{1+q}{q}f(x)+\frac{1}{q}f(qx)]. $$


title: Attractors with Vanishing Central Charge

abstract:
  We consider the Attractor Equations of particular $\mathcal{N}=2$, d=4
supergravity models whose vector multiplets' scalar manifold is endowed with
homogeneous symmetric cubic special K\"{a}hler geometry, namely of the
so-called $st^{2}$ and $stu$ models. In this framework, we derive explicit
expressions for the critical moduli corresponding to non-BPS attractors with
vanishing $\mathcal{N}=2$ central charge. Such formul\ae hold for a generic
black hole charge configuration, and they are obtained without formulating any
\textit{ad hoc} simplifying assumption. We find that such attractors are
related to the 1/2-BPS ones by complex conjugation of some moduli. By uplifting
to $\mathcal{N}=8$, d=4 supergravity, we give an interpretation of such a
relation as an exchange of two of the four eigenvalues of the $\mathcal{N}=8$
central charge matrix $Z_{AB}$. We also consider non-BPS attractors with
non-vanishing $\mathcal{Z}$; for peculiar charge configurations, we derive
solutions violating the Ansatz usually formulated in literature. Finally, by
group-theoretical considerations we relate Cayley's hyperdeterminant (the
invariant of the stu model) to the invariants of the st^{2} and of the
so-called t^{3} model.


title:
Plasmon dispersion in metal nanoparticle chains from angle-resolved
  scattering

abstract:
  We present angle and frequency resolved optical extinction measurements to
determine the dispersion relation of plasmon modes on Ag and Au nanoparticle
chains with pitches down to 75 nm. The large splitting between transverse and
longitudinal modes and the band curvature are inconsistent with reported
electrostatic near-field models, and confirm that far-field retarded
interactions are important, even for $\lambda/5$-sized structures. The data
imply that lower propagation losses, larger signal bandwidth and larger maximum
group velocity then expected can be achieved for wave vectors below the light
line. We conclude that for the design of optical nanocircuits coherent
far-field couplings across the entire circuit need to be considered, even at
subwavelength feature sizes.


title: An explicit formula for the characters of the symmetric group

abstract:
  We give an explicit expression of the normalized characters of the symmetric
group in terms of the contents of the partition labelling the representation.


title:
Origin of the Metallicity Dependence of Exoplanet Host Stars in the
  Protoplanetary Disk Mass Distribution

abstract:
  The probability of a star hosting a planet that is detectable in radial
velocity surveys increases Ppl(Z) oc 10^2Z, where Z is metallicity. Core
accretion models reproduce this trend, since the protoplanetary disk of a high
metallicity star has a high density of solids and so forms cores which accrete
gas before the primordial gas disk dissipates. This paper considers the origin
of the form of Ppl(Z). We introduce a simple model in which detectable planets
form when the mass of solids in the protoplanetary disk, Ms, exceeds a critical
value. In this model the form of Ppl(Z) is a direct reflection of the
distribution of protoplanetary disk masses, Mg, and the observed Ppl(Z) is
reproduced if P(Mg>Mg') oc 1/Mg'^2. We argue that a protoplanetary disk's
sub-mm dust mass is a pristine indicator of the mass available for
planet-building and find the observed sub-mm disk mass distribution is
consistent with the observed Ppl(Z) if Ms>0.5M_J is required to form detectable
planets. Any planet formation model which imposes a critical solid mass for
planet formation would reproduce the observed Ppl(Z), and core accretion models
are empirically consistent with a threshold criterion. We identify 7
protoplanetary disks which, by rigid application of this criterion, would be
expected to form detectable planets. A testable prediction is that Ppl(Z)
should flatten both for Z>0.5dex and as more distant and lower mass planets are
discovered. Further, combining this model with one in which the evolution of a
star's debris disk is also influenced by the solid mass in its protoplanetary
disk, results in the prediction that debris disks detected around stars with
planets should be more infrared luminous than those around stars without
planets in tentative agreement with recent observations.


title: Pulsating Casimir force

abstract:
  Based on the Lifshitz theory we show that the illumination of one (Si) plate
in the three-layer systems Au--ethanol--Si, Si--ethanol--Si and
$\alpha$-Al${}_2$O${}_3$--ethanol--Si with laser pulses can change the Casimir
attraction to Casimir repulsion and vice versa. The proposed effect opens novel
opportunities in nanotechnology to actuate the periodic movement in electro-
and optomechanical micromachines based entirely on the zero-point oscillations
of the quantum vacuum without the action of mechanical springs.


title: The hard synchrotron X-ray spectrum of the TeV BL Lac 1ES 1426+428

abstract:
  We have observed 1ES 1426+428 with INTEGRAL detecting it up to $\sim$150 keV.
The spectrum is hard, confirming that this source is an extreme BL Lac object,
with a synchrotron component peaking, in a $\nu F_\nu$ plot, at or above 100
keV, resembling the hard states of Mkn 501 and 1ES 2344+514. All these three
sources are TeV emitters, with 1ES 1426+428 lying at a larger redshift
(z=0.129): for this source the absorption of high energy photons by the IR
cosmic background is particularly relevant. The observed hard synchrotron tail
helps the modeling of its spectral energy distribution, giving information on
the expected intrinsic shape and flux in the TeV band. This in turn constrains
the amount of the poorly known IR background.


title: Non-Hermitian Quantum Systems and Time-Optimal Quantum Evolution

abstract:
  Recently, Bender et al. have considered the quantum brachistochrone problem
for the non-Hermitian $\cal PT$-symmetric quantum system and have shown that
the optimal time evolution required to transform a given initial state
$|\psi_i\rangle$ into a specific final state $|\psi_f\rangle$ can be made
arbitrarily small. Additionally, it has been shown that finding the shortest
possible time requires only the solution of the two-dimensional problem for the
quantum system governed by the effective Hamiltonian acting in the subspace
spanned by $|\psi_i\rangle$ and $|\psi_f\rangle$. In this paper, we study a
similar problem for the generic non-Hermitian Hamiltonian, focusing our
attention on the geometric aspects of the problem.


title:
Black Holes in Cascading Theories: Confinement/Deconfinement Transition
  and other Thermal Properties

abstract:
  We present numerical evidence for a transition between the Klebanov-Strassler
background and a solution describing a black hole in the class of cascading
solutions in the chirally restored phase. We also present a number of
properties of this solution, including the running of the coupling constant,
the viscosity to entropy ratio and the drag force on a quark moving in this
background.


title: Confinement from gluodynamics in curved space-time

abstract:
  We determine the static potential for a heavy quark-antiquark pair from
gluodynamics in curved space-time. Our calculation is done within the framework
of the gauge-invariant, path-dependent, variables formalism. The potential
energy is the sum of a Yukawa and a linear potential, leading to the
confinement of static charges.


title: On Cycles in the Transcription Network of Saccharomyces cerevisiae

abstract:
  We investigate the cycles in the transcription network of S. cerevisiae.
Unlike a similar network of E. coli, it contains many cycles. We characterize
properties of these cycles and their place in the regulatory mechanism of the
cell. Almost all cycles in the transcription network of S. cerevisiae are
contained in a single strongly connected component, which we call LSCC (L for
``largest''), except for a single cycle of two transcription factors. Among
different physiological conditions, cell cycle has the most significant
relationship with LSCC, as the set of 64 transcription interactions that are
active in all phases of the cell cycle has overlap of 27 with the interactions
of LSCC (of which there are 49). Conversely, if we remove the interactions that
are active in all phases of the cell cycle (fewer than 1% of the total), the
LSCC would have only three nodes and 5 edges, 4 of which are active only in the
stress response subnetwork. LSCC has a special place in the topology of the
network and it can be used to define a natural hierarchy in the network; in
every physiological subnetwork LSCC plays a pivotal role. Apart from those
well-defined conditions, the transcription network of S. cerevisiae is devoid
of cycles. It was observed that two conditions that were studied and that have
no cycles of their own are exogenous: diauxic shift and DNA repair, while cell
cycle, sporulation are endogenous.


title:
Mass, radius, and composition of the outer crust of nonaccreting cold
  neutron stars

abstract:
  The properties and composition of the outer crust of nonaccreting cold
neutron stars are studied by applying the model of Baym, Pethick, and
Sutherland, which was extended by including higher order corrections of the
atomic binding, screening, exchange and zero-point energy. The most recent
experimental nuclear data from the atomic mass table of Audi, Wapstra, and
Thibault from 2003 is used. Extrapolation to the drip line is utilized by
various state-of-the-art theoretical nuclear models (finite range droplet,
relativistic nuclear field and non-relativistic Skyrme Hartree-Fock
parameterizations). The different nuclear models are compared with respect to
the mass and radius of the outer crust for different neutron star
configurations and the nuclear compositions of the outer crust.


title:
Equidistribution of negative statistics and quotients of Coxeter groups
  of type B and D

abstract:
  We generalize some identities and q-identities previously known for the
symmetric group to Coxeter groups of type B and D. The extended results include
theorems of Foata and Sch\"utzenberger, Gessel, and Roselle on various
distributions of inversion number, major index, and descent number. In order to
show our results we provide caracterizations of the systems of minimal coset
representatives of Coxeter groups of type B and D.


title: Description of double beta decay within continuum-QRPA

abstract:
  A method to calculate the nuclear double beta decay ($2\nu\beta\beta$- and
$0\nu\beta\beta$-) amplitudes within the continuum random phase approximation
(cQRPA) is formulated. Calculations of the $\beta\beta$ transition amplitudes
within the cQRPA are performed for ^{76}Ge, ^{100}Mo and ^{130}Te. A rather
simple nuclear Hamiltonian consisting of phenomenological mean field and
zero-range residual particle-hole and particle-particle interaction is used.
The calculated M^{2\nu} are almost not affected when the single-particle
continuum is taken into account. At the same time, a regular suppression of the
$0\nu\beta\beta$-amplitude is found that can be associated with additional
ground state correlations due to collective states in the continuum. It is
expected that future inclusion of the nucleon pairing in the single-particle
continuum will somewhat compensate the suppression.


title: Charge Order Superstructure with Integer Iron Valence in Fe2OBO3

abstract:
  Solution-grown single crystals of Fe2OBO3 were characterized by specific
heat, Mossbauer spectroscopy, and x-ray diffraction. A peak in the specific
heat at 340 K indicates the onset of charge order. Evidence for a doubling of
the unit cell at low temperature is presented. Combining structural refinement
of diffraction data and Mossbauer spectra, domains with diagonal charge order
are established. Bond-valence-sum analysis indicates integer valence states of
the Fe ions in the charge ordered phase, suggesting Fe2OBO3 is the clearest
example of ionic charge order so far.


title:
Simulation of the Formation and Morphology of Ice Mantles on
  Interstellar Grains

abstract:
  Although still poorly understood, the chemistry that occurs on the surfaces
of interstellar dust particles profoundly affects the growth of molecules in
the interstellar medium. An important set of surface reactions produces icy
mantles of many monolayers in cold and dense regions. The monolayers are
dominated by water ice, but also contain CO, CO_{2}, and occasionally methanol
as well as minor constituents. In this paper, the rate of production of
water-ice dominated mantles is calculated for different physical conditions of
interstellar clouds and for the first time images of the morphology of
interstellar ices are presented. For this purpose, the continuous-time
random-walk Monte Carlo simulation technique has been used. The visual
extinction, density, and gas and grain temperatures are varied. It is shown
that our stochastic approach can reproduce the important observation that ice
mantles only grow in the denser regions.


title: On the renormalization of the bosonized multi-flavor Schwinger model

abstract:
  The phase structure of the bosonized multi-flavor Schwinger model is
investigated by means of the differential renormalization group (RG) method. In
the limit of small fermion mass the linearized RG flow is sufficient to
determine the low-energy behavior of the N-flavor model, if it has been rotated
by a suitable rotation in the internal space. For large fermion mass, the exact
RG flow has been solved numerically. The low-energy behavior of the
multi-flavor model is rather different depending on whether N=1 or N>1, where N
is the number of flavors. For N>1 the reflection symmetry always suffers
breakdown in both the weak and strong coupling regimes, in contrary to the N=1
case, where it remains unbroken in the strong coupling phase.


title:
The primordial binary population II: Recovering the binary population
  for intermediate mass stars in Sco OB2

abstract:
  We characterize the binary population in the young and nearby OB association
Scorpius OB2 using available observations of visual, spectroscopic, and
astrometric binaries with intermediate-mass primaries. We take into account
observational biases by comparing the observations with simulated observations
of model associations. The available data indicate a large binary fraction (>
70% with 3sigma confidence), with a large probability that all intermediate
mass stars in Sco OB2 are part of a binary system. The binary systems have a
mass ratio distribution of the form f(q) ~ q^-0.4. Sco OB2 has a semi-major
axis distribution of the form f(log a) ~ constant (Opik's law), in the range
5-5e6 Rsun. The log-normal period distribution of Duquennoy & Mayor results in
too few spectroscopic binaries, even if the model binary fraction is 100%. Sco
OB2 is a young association with a low stellar density; its current population
is expected to be very similar to the primordial population. The fact that
practically all stars in Sco OB2 are part of a binary (or multiple) system
demonstrates that multiplicity is a fundamental factor in the star formation
process, at least for intermediate mass stars.


title: Magnetohydrodynamic properties of incompressible Meissner fluids

abstract:
  We consider a superconducting material that exists in the liquid state, more
precisely, in which the Meissner-Ochsenfeld effect persists in the liquid
state. First, we investigate how the shape of such a hypothetical Meissner
liquid will adapt to accomodate for an applied external field. In particular,
we analyse the case of a droplet of Meissner fluid, and compute the elongation
of the droplet and its quadrupole frequency as a function of the applied field.
Next, the influence of an applied field on the flow of the liquid is studied
for the case of a surface wave. We derive the dispersion relation for surface
waves on an incompressible Meissner fluid. We discuss some candidate
realizations of the Meissner fluids and for the case of a superconducting
colloid discuss which regime of wave lengths would be most affected by the
Meissner effect.


title: Theory of gravitation theories: a no-progress report

abstract:
  Already in the 1970s there where attempts to present a set of ground rules,
sometimes referred to as a theory of gravitation theories, which theories of
gravity should satisfy in order to be considered viable in principle and,
therefore, interesting enough to deserve further investigation. From this
perspective, an alternative title of the present paper could be ``why are we
still unable to write a guide on how to propose viable alternatives to general
relativity?''. Attempting to answer this question, it is argued here that
earlier efforts to turn qualitative statements, such as the Einstein
Equivalence Principle, into quantitative ones, such as the metric postulates,
stand on rather shaky grounds -- probably contrary to popular belief -- as they
appear to depend strongly on particular representations of the theory. This
includes ambiguities in the identification of matter and gravitational fields,
dependence of frequently used definitions, such as those of the stress-energy
tensor or classical vacuum, on the choice of variables, etc. Various examples
are discussed and possible approaches to this problem are pointed out. In the
course of this study, several common misconceptions related to the various
forms of the Equivalence Principle, the use of conformal frames and equivalence
between theories are clarified.


title: Black holes: interfacing the classical and the quantum

abstract:
  The central idea advocated in this paper is that {forming the black hole
horizon is attended with transition from the classical regime of evolution to
the quantum one}. We justify the following criterion for discriminating between
the classical and the quantum: {spontaneous creations and annihilations of
particle-antiparticle pairs are impossible in the classical world but possible
in the quantum world}. We show that it is sufficient to {change the overall
sign of the spacetime signature in the classical picture of field propagation
for it to be treated as its associated quantum picture}. To describe a
self-gravitating object at the last stage of its classical evolution, we
propose to use the Foldy--Wouthuysen representation of the Dirac equation in
curved spacetimes, and the Gozzi classical path integral. In both approaches,
maintaining the dynamics in the classical regime is controlled by
supersymmetry.


title: Multiple Equilibria in a Single-Column Model of the Tropical Atmosphere

abstract:
  A single-column model run under the weak temperature gradient approximation,
a parameterization of large-scale dynamics appropriate for the tropical
atmosphere, is shown to have multiple stable equilibria. Under conditions
permitting persistent deep convection, the model has a statistically steady
state in which such convection occurs, as well as an extremely dry state in
which convection does not occur. Which state is reached depends on the initial
moisture profile.


title:
Final stare interaction enhancement effect on the near threshold p\bar p
  system in B^\pm\to p\bar p \p^\pm decay

abstract:
  We discuss the low-mass enhancement effect in the baryon-antibaryon invariant
mass in three-body baryonic B decays using final state interactions in the
framework of Regge theory. We show that the rescattering between baryonic pair
can reproduce the observed mass spectrum.


title:
A Silver Anniversary Observation of the X-ray Emitting SN1978K in NGC
  1313

abstract:
  We describe the results of a 2003 Chandra ACIS-I observation of SN1978K. The
spectrum shows little flux below 0.6 keV, in contrast to the 2002 ACIS-S
observation that showed flux to 0.4 keV. Fitting the ACIS-I spectrum alone
leads to two solutions depending upon the value of the column density. A joint
fit using a dual thermal plasma model applied to the ACIS-I and a
contemporaneous XMM spectrum, which if fit alone also leads to a two-column
solution, yields a single column density fit. The fitted temperature of the
joint fit for the soft component remains constant with the errors from previous
Chandra, XMM, and ASCA data. The hard temperature recovers from its 2000-2002
decline and corresponds to an increase in the column density during that time.
The hard (2-10 keV) light curve is confirmed to be declining. The derived
number density represents a lower limit of 1e5 depending upon the adopted
filling factor of the emitting volume, leading to an estimated mass cooling
rate of 0.1-0.15 solar masses per year.


title:
Extreme statistics for time series: Distribution of the maximum relative
  to the initial value

abstract:
  The extreme statistics of time signals is studied when the maximum is
measured from the initial value. In the case of independent, identically
distributed (iid) variables, we classify the limiting distribution of the
maximum according to the properties of the parent distribution from which the
variables are drawn. Then we turn to correlated periodic Gaussian signals with
a 1/f^alpha power spectrum and study the distribution of the maximum relative
height with respect to the initial height (MRH_I). The exact MRH_I distribution
is derived for alpha=0 (iid variables), alpha=2 (random walk), alpha=4 (random
acceleration), and alpha=infinity (single sinusoidal mode). For other,
intermediate values of alpha, the distribution is determined from simulations.
We find that the MRH_I distribution is markedly different from the previously
studied distribution of the maximum height relative to the average height for
all alpha. The two main distinguishing features of the MRH_I distribution are
the much larger weight for small relative heights and the divergence at zero
height for alpha>3. We also demonstrate that the boundary conditions affect the
shape of the distribution by presenting exact results for some non-periodic
boundary conditions. Finally, we show that, for signals arising from
time-translationally invariant distributions, the density of near extreme
states is the same as the MRH_I distribution. This is used in developing a
scaling theory for the threshold singularities of the two distributions.


title:
On the internal space dependence of the static quark-antiquark potential
  in ${\cal N}=4$ SYM plasma wind

abstract:
  We study the effect of the relative S^5-angle of a quark and an antiquark on
their static potential and the related screening length in a strongly coupled
moving ${\cal N}=4$ SYM plasma. The large velocity scaling law for the
screening length holds for any relative S^5-angle $\theta$. However, the
velocity independent prefactor Z strongly depends on $\theta$. For comparison
with QCD we propose to average Z over all relative orientations on S^5. This
generates a suppression factor relative to the case $\theta =0$.


title: Ricci Nilsoliton Black Holes

abstract:
  We follow a constructive approach and find higher-dimensional black holes
with Ricci nilsoliton horizons. The spacetimes are solutions to Einstein's
equation with a negative cosmological constant and generalises therefore,
anti-de Sitter black hole spacetimes. The approach combines a work by Lauret --
which relate so-called Ricci nilsolitons and Einstein solvmanifolds -- and an
earlier work by the author. The resulting black hole spacetimes are
asymptotically Einstein solvmanifolds and thus, are examples of solutions which
are not asymptotically Anti-de Sitter. We show that any nilpotent group in
dimension $n\leq 6$ has a corresponding Ricci nilsoliton black hole solution in
dimension (n+2). Furthermore, we show that in dimensions (n+2)>8, there exists
an infinite number of locally distinct Ricci nilsoliton black hole metrics.


title:
First results on double beta decay modes of Cd, Te and Zn isotopes with
  the COBRA experiment

abstract:
  Four 1cm^3 CdZnTe semiconductor detectors were operated in the Gran Sasso
National Laboratory to explore the feasibility of such devices for double beta
decay searches as proposed for the COBRA experiment. The research involved
background studies accompanied by measurements of energy resolution performed
at the surface. Energy resolutions sufficient to reduce the contribution of
two-neutrino double beta decay events to a negligible level for a large scale
experiment have already been achieved and further improvements are expected.
Using activity measurements of contaminants in all construction materials a
background model was developed with the help of Monte Carlo simulations and
major background sources were identified. A total exposure of 4.34 kg.days of
underground data has been accumulated allowing a search for neutrinoless double
beta decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.)
are presented for decays to ground and excited states. Four improved lower
limits have been obtained, including zero neutrino double electron capture
transitions of Zn64 and Te120 to the ground state, which are 1.19*10^{17} years
and 2.68*10^{15} years respectively.


title: Singular Oscillatory Integrals on R^n

abstract:
  Let Pd,n denote the space of all real polynomials of degree at most d on R^n.
We prove a new estimate for the logarithmic measure of the sublevel set of a
polynomial P in Pd,1. Using this estimate, we prove a sharp estimate for a
singular oscillatory integral on R^n.


title:
Measurement of the Semileptonic Decays B --> D tau nubar and B --> D*
  tau nubar

abstract:
  We present preliminary measurements of branching fractions for the
semileptonic decays B --> D tau nubar and B --> D* tau nubar, which are
potentially sensitive to non--Standard Model amplitudes. The data sample
comprises 232x10^6 Upsilon(4S) --> BBbar decays collected with the BaBar
detector at the PEP-II e+e- storage ring. We obtain B(B- --> D0 tau nubar) =
(0.63 +/- 0.38 +/- 0.10 +/- 0.06)%, B(B- --> D*0 tau nubar) = (2.35 +/- 0.49
+/- 0.22 +/- 0.18)%, B(B0bar --> D+ tau nubar) = (1.03 +/- 0.35 +/- 0.14 +/-
0.10)%, and B(B0bar --> D*+ tau nubar) = (1.15 +/- 0.33 +/- 0.04 +/- 0.04)%,
where the uncertainties are statistical, systematic, and normalization,
respectively. By combining B- and B0bar results, we also obtain the branching
fractions B(B --> D tau nubar) = (0.90 +/- 0.26 +/- 0.11 +/- 0.06)% and B(B -->
D* tau nubar) = (1.81 +/- 0.33 +/- 0.11 +/- 0.06)% (quoted for the B-
lifetime), with significances of 3.5 sigma and 6.2 sigma.


title:
Encapsulation, compensation, and substitution of catalyst particles
  during continuous growth of carbon nanotubes

abstract:
  By sequential feeding of catalyst materials, it is revealed that the active
growth sites are at the bottom of the carbon nanotubes (CNTs), and that
catalyst particles are constantly encapsulated into nanotubes from the bottom.
This gives a better insight into the mechanism of CNT formation and on ways to
control the growth process. CNTs encapsulated with different materials should
enable the study of their electronic or magnetic properties, with potential
applications as building blocks for nanoelectronics and as fillers in
composites for electromagenetic shielding.


title: Spanning Trees with Many Leaves in Graphs without Diamonds and Blossoms

abstract:
  It is known that graphs on n vertices with minimum degree at least 3 have
spanning trees with at least n/4+2 leaves and that this can be improved to
(n+4)/3 for cubic graphs without the diamond K_4-e as a subgraph. We generalize
the second result by proving that every graph with minimum degree at least 3,
without diamonds and certain subgraphs called blossoms, has a spanning tree
with at least (n+4)/3 leaves, and generalize this further by allowing vertices
of lower degree. We show that it is necessary to exclude blossoms in order to
obtain a bound of the form n/3+c.
  We use the new bound to obtain a simple FPT algorithm, which decides in
O(m)+O^*(6.75^k) time whether a graph of size m has a spanning tree with at
least k leaves. This improves the best known time complexity for MAX LEAF
SPANNING TREE.


title: Muon-fluorine entangled states in molecular magnets

abstract:
  The information accessible from a muon-spin relaxation experiment is often
limited since we lack knowledge of the precise muon stopping site. We
demonstrate here the possibility of localizing a spin polarized muon in a known
stopping state in a molecular material containing fluorine. The muon-spin
precession that results from the entangled nature of the muon-spin and
surrounding nuclear spins is sensitive to the nature of the stopping site and
we use this property to identify three classes of site. We are also able to
describe the extent to which the muon distorts its surroundings.


title:
Darboux Transformation of the Green Function for the Dirac Equation with
  the Generalized Potential

abstract:
  We consider the Darboux transformation of the Green functions of the regular
boundary problem of the one-dimensional stationary Dirac equation. We obtained
the Green functions of the transformed Dirac equation with the initial regular
boundary conditions. We also construct the formula for the unabridged trace of
the difference of the transformed and the initial Green functions of the
regular boundary problem of the one-dimensional stationary Dirac equation. We
illustrate our findings by the consideration of the Darboux transformation for
the Green function of the free particle Dirac equation on an interval.


title:
Large Area Growth of Aligned CNT Arrays on Spheres: Towards the Large
  Scale and Continuous Production

abstract:
  A novel strategy for the large scale and continuous production of aligned
carbon nanotube arrays using millimeter-diameter spheres as growth substrates
is reported. The present technique is more productive than the conventional
process on flat wafers because of the higher available growth surface and the
good fluidity of the spherical substrates. It can be adapted for the industrial
production and application of aligned carbon nanotube arrays with lengths up to
millimeter.


title: Velocities from Cross-Correlation: A Guide for Self-Improvement

abstract:
  The measurement of Doppler velocity shifts in spectra is a ubiquitous theme
in astronomy, usually handled by computing the cross-correlation of the
signals, and finding the location of its maximum. This paper addresses the
problem of the determination of wavelength or velocity shifts among multiple
spectra of the same, or very similar, objects. We implement the classical
cross-correlation method and experiment with several simple models to determine
the location of the maximum of the cross-correlation function. We propose a new
technique, 'self-improvement', to refine the derived solutions by requiring
that the relative velocity for any given pair of spectra is consistent with all
others. By exploiting all available information, spectroscopic surveys
involving large numbers of similar objects may improve their precision
significantly. As an example, we simulate the analysis of a survey of G-type
stars with the SDSS instrumentation. Applying 'self-improvement' refines
relative radial velocities by more than 50% at low signal-to-noise ratio. The
concept is equally applicable to the problem of combining a series of
spectroscopic observations of the same object, each with a different Doppler
velocity or instrument-related offset, into a single spectrum with an enhanced
signal-to-noise ratio.


title:
Magnetic domain fluctuations in an antiferromagnetic film observed with
  coherent resonant soft x-ray scattering

abstract:
  We report the direct observation of slow fluctuations of helical
antiferromagnetic domains in an ultra-thin holmium film using coherent resonant
magnetic x-ray scattering. We observe a gradual increase of the fluctuations in
the speckle pattern with increasing temperature, while at the same time a
static contribution to the speckle pattern remains. This finding indicates that
domain-wall fluctuations occur over a large range of time scales. We ascribe
this non-ergodic behavior to the strong dependence of the fluctuation rate on
the local thickness of the film.

categories: cond-mat.other cond-mat.dis-nn cond-mat.mes-hall cond-mat.str-el


title:
A two-state model for helicase translocation and unwinding of nucleic
  acids

abstract:
  Helicases are molecular motors that unwind double-stranded nucleic acids
(dsNA), such as DNA and RNA). Typically a helicase translocates along one of
the NA single strands while unwinding and uses adenosine triphosphate (ATP)
hydrolysis as an energy source. Here we model of a helicase motor that can
switch between two states, which could represent two different points in the
ATP hydrolysis cycle. Our model is an extension of the earlier
Betterton-J\"ulicher model of helicases to incorporate switching between two
states. The main predictions of the model are the speed of unwinding of the
dsNA and fluctuations around the average unwinding velocity. Motivated by a
recent claim that the NS3 helicase of Hepatitis C virus follows a flashing
ratchet mechanism, we have compared the experimental results for the NS3
helicase with a special limit of our model which corresponds to the flashing
ratchet scenario. Our model accounts for one key feature of the experimental
data on NS3 helicase. However, contradictory observations in experiments
carried out under different conditions limit the ability to compare the model
to experiments.


title:
Strange quark contributions to neutrino and antineutrino nucleus
  scattering via neutral current in quasi-elastic region

abstract:
  Strange quark contributions to the neutral current reaction in the neutrino
scattering are investigated on the nucleon level and extended to the $^{12}$C
target nucleus through the neutrino-induced knocked-out nucleon process in the
quasi-elastic region within the framework of a relativistic single particle
model. The incident energy range between 500 MeV and 1.0 GeV is used for the
neutrino(antineutrino) scattering. Effects of the final state interaction for
the knocked-out nucleon are included by a relativistic optical potential. We
found that the sensitivity of the strange quark contents could be salient on
the asymmetry between neutrino and antineutrino scattering cross sections. In
specific, $A (\nu ({\bar \nu}), \nu^{'} ({\bar \nu}^{'}) N)$ reaction is shown
to be very sensitive test in the searches of the strangeness.


title: Incompressible fluid inside an astrophysical black hole?

abstract:
  It is argued that under natural hypothesis the Fermions inside a black hole
formed after the collapse of a neutron star could form a non compressible fluid
(well before reaching the Planck scale) leading to some features of integer
Quantum Hall Effect. The relations with black hole entropy are analyzed.
Insights coming from Quantum Hall Effect are used to analyze the coupling with
Einstein equations. Connections with some cosmological scenarios and with
higher dimensional Quantum Hall Effect are shortly pointed out.


title: Dynamics of Dense Cores in the Perseus Molecular Cloud

abstract:
  We survey the kinematics of over one hundred and fifty candidate (and
potentially star-forming) dense cores in the Perseus molecular cloud with
pointed N2H+(1-0) and simultaneous C18O(2-1) observations. Our detection rate
of N2H+ is 62%, rising to 84% for JCMT SCUBA-selected targets. In agreement
with previous observations, we find that the dense N2H+ targets tend to display
nearly thermal linewidths, particularly those which appear to be starless
(using Spitzer data), indicating turbulent support on the small scales of
molecular clouds is minimal. For those N2H+ targets which have an associated
SCUBA dense core, we find their internal motions are more than sufficient to
provide support against the gravitational force on the cores. Comparison of the
N2H+ integrated intensity and SCUBA flux reveals fractional N2H+ abundances
between 10^-10 and 10^-9. We demonstrate that the relative motion of the dense
N2H+ gas and the surrounding C18O gas is less than the sound speed in the vast
majority of cases (~90%). The point-to-point motions we observe within larger
extinction regions appear to be insufficient to provide support against
gravity, although we sparsely sample these regions.


title: Neon Abundances from a Spitzer/IRS Survey of Wolf-Rayet Stars

abstract:
  We report on neon abundances derived from {\it Spitzer} high resolution
spectral data of eight Wolf-Rayet (WR) stars using the forbidden line of
[\ion{Ne}{3}] 15.56 microns. Our targets include four WN stars of subtypes
4--7, and four WC stars of subtypes 4--7. We derive ion fraction abundances
$\gamma$ of Ne^{2+} for the winds of each star. The ion fraction abundance is a
product of the ionization fraction $Q_{\rm i}$ in stage i and the abundance by
number ${\cal A}_E$ of element E relative to all nuclei. Values generally
consistent with solar are obtained for the WN stars, and values in excess of
solar are obtained for the WC stars.


title:
The pressure confined wind of the massive and compact superstar cluster
  M82-A1

abstract:
  The observed parameters of the young superstar cluster M82-A1 and its
associated compact HII region are here shown to indicate a low heating
efficiency or immediate loss, through radiative cooling, of a large fraction of
the energy inserted by stellar winds and supernovae during the early evolution
of the cluster. This implies a bimodal hydrodynamic solution which leads to a
reduced mass deposition rate into the ISM, with a much reduced outflow
velocity. Furthermore, to match the observed parameters of the HII region
associated to M82-A1, the resultant star cluster wind is here shown to ought to
be confined by a high pressure interstellar medium. The cluster wind
parameters, as well as the location of the reverse shock, its cooling length
and the radius of the standing outer HII region are derived analytically. All
of these properties are then confirmed with a semi-analytical integration of
the flow equations, which provides us also with the run of the hydrodynamic
variables as a function of radius. The impact of the results is discussed and
extended to other massive and young superstar clusters surrounded by a compact
HII region.


title: Bures metric over thermal state manifolds and quantum criticality

abstract:
  We analyze the Bures metric over the manifold of thermal density matrices for
systems featuring a zero temperature quantum phase transition. We show that the
quantum critical region can be characterized in terms of the temperature
scaling behavior of the metric tensor itself. Furthermore, the analysis of the
metric tensor when both temperature and an external field are varied, allows to
complement the understanding of the phase diagram including cross-over regions
which are not characterized by any singular behavior. These results provide a
further extension of the scope of the metric approach to quantum criticality.


title:
The dynamical hole in ultrafast photoassociation: analysis of the
  compression effect

abstract:
  Photoassociation of a pair of cooled atoms by excitation with a short chirped
laser pulse creates a dynamical hole in the initial continuum wavefunction.
This hole is manifested by a void in the pair wavefunction and a momentum kick.
Photoassociation into loosely bound levels of the external well in Cs_2
0$_g^-$(6S + 6P$_{3/2}$ is considered as a case study. After the pulse, the
free evolution of the ground triplet state wavepacket is analyzed. Due to a
negative momentum kick, motion to small distances is manifested and a
compression effect is pointed out, markedly increasing the density of atom
pairs at short distance. A consequence of the hole is the redistribution of the
vibrational population in the ground triplet state, with population of the last
bound level and creation of pairs of hot atoms. The physical interpretation
makes use of the time dependence of the probability current and population on
each channel to understand the role of the parameters of the photoassociation
pulse. By varying such parameters, optimization of the compression effect in
the ground state wavepacket is demonstrated. Due to an increase of the short
range density probability by more than two orders of magnitude, we predict
important photoassociation rates into deeply bound levels of the excited state
by a second pulse, red-detuned relative to the first one and conveniently
delayed.


title:
Mesoscopic model for the fluctuating hydrodynamics of binary and ternary
  mixtures

abstract:
  A recently introduced particle-based model for fluid dynamics with continuous
velocities is generalized to model immiscible binary mixtures. Excluded volume
interactions between the two components are modeled by stochastic multiparticle
collisions which depend on the local velocities and densities. Momentum and
energy are conserved locally, and entropically driven phase separation occurs
for high collision rates. An explicit expression for the equation of state is
derived, and the concentration dependence of the bulk free energy is shown to
be the same as that of the Widom-Rowlinson model. Analytic results for the
phase diagram are in excellent agreement with simulation data. Results for the
line tension obtained from the analysis of the capillary wave spectrum of a
droplet agree with measurements based on the Laplace's equation. The
introduction of "amphiphilic" dimers makes it possible to model the phase
behavior and dynamics of ternary surfactant mixtures.


title:
Uniqueness theorem for 5-dimensional black holes with two axial Killing
  fields

abstract:
  We show that two stationary, asymptotically flat vacuum black holes in 5
dimensions with two commuting axial symmetries are identical if and only if
their masses, angular momenta, and their ``rod structures'' coincide. We also
show that the horizon must be topologically either a 3-sphere, a ring, or a
Lens-space. Our argument is a generalization of constructions of Morisawa and
Ida (based in turn on key work of Maison) who considered the spherical case,
combined with basic arguments concerning the nature of the factor manifold of
symmetry orbits.


title:
A presentation for the mapping class group of a non-orientable surface
  from the action on the complex of curves

abstract:
  We study the action of the mapping class group M(F) on the complex of curves
of a non-orientable surface F. We obtain, by using a result of K. S. Brown, a
presentation for M(F) defined in terms of the mapping class groups of the
complementary surfaces of collections of curves, provided that F is not
sporadic, i.e. the complex of curves of F is simply connected. We also compute
a finite presentation for the mapping class group of each sporadic surface.


title: Suppression of hole-mediated ferromagnetism in GaMnP by hydrogen

abstract:
  We report the successful passivation of the Mn acceptors in GaMnP upon
exposure to a remote dc hydrogen plasma. The as-grown films are non-metallic
and ferromagnetic with a Curie temperature of T_C=55K. After hydrogenation the
sample resistivity increases by approximately three orders of magnitude at room
temperature and six orders of magnitude at 25 K. Furthermore, the hydrogenated
samples are paramagnetic, which is evidenced by a magnetization curve at 5 K
that is best described by a Brillouin function with g=2 and J=5/2 expected for
Mn atoms in the 3d^5 configuration. These observations unambiguously proof that
the ferromagnetism is carrier-mediated also in GaMnP.


title: Spitzer Transit and Secondary Eclipse Photometry of GJ 436b

abstract:
  We report the results of infrared (8 micron) transit and secondary eclipse
photometry of the hot Neptune exoplanet, GJ436b using Spitzer. The nearly
photon-limited precision of these data allow us to measure an improved radius
for the planet, and to detect the secondary eclipse. The transit (centered at
HJD = 2454280.78149 +/-0.00016) shows the flat-bottomed shape typical of
infrared transits, and it precisely defines the planet-to-star radius ratio
(0.0839 +/-0.0005), independent of the stellar properties. However, we obtain
the planetary radius, as well as the stellar mass and radius, by fitting to the
transit curve simultaneously with an empirical mass-radius relation for
M-dwarfs (M=R). We find Rs=Ms=0.47 +/-0.02 in solar units, and Rp=27,600
+/-1170 km (4.33 +/-0.18 Earth radii). This radius significantly exceeds the
radius of a naked ocean planet, and requires a gasesous hydrogen-helium
envelope. The secondary eclipse occurs at phase 0.587 +/-0.005, proving a
significant orbital eccentricity (e=0.15 +/-0.012). The amplitude of the
eclipse (5.7 +/-0.8e-4) indicates a brightness temperature for the planet of
T=712 +/-36K. If this is indicative of the planet's physical temperature, it
suggests the occurrence of tidal heating in the planet. An uncharacterized
second planet likely provides ongoing gravitational perturbations, to maintain
GJ436b's orbit eccentricity over long time scales.


title: Independent Noise Approximation for Spin-Boson Decoherence

abstract:
  Quantum error correction is a solution to preserve the fidelity of quantum
information encoded in physical systems subject to noise. However, unfavorable
correlated errors could be induced even for non-interacting qubits through the
environment (bath), when they are "packed" together. The question is, to what
extent can we treat the noise induced by the bath as independent? In the
context of the spin-boson model, we show that, under some reasonable
constraints, the independent noise approximation could be valid. On the other
hand, in the strongly correlated limit, we show how the method of decoherence
free subspace can be made applicable. Combining these two methods makes
fault-tolerant quantum computation promising in fighting against correlated
errors.


title: On the ergodic sum-rate performance of CDD in multi-user systems

abstract:
  The main focus of space-time coding design and analysis for MIMO systems has
been so far focused on single-user systems. For single-user systems, transmit
diversity schemes suffer a loss in spectral efficiency if the receiver is
equipped with more than one antenna, making them unsuitable for high rate
transmission. One such transmit diversity scheme is the cyclic delay diversity
code (CDD). The advantage of CDD over other diversity schemes such as
orthogonal space-time block codes (OSTBC) is that a code rate of one and delay
optimality are achieved independent of the number of transmit antennas. In this
work we analyze the ergodic rate of a multi-user multiple access channel (MAC)
with each user applying such a cyclic delay diversity (CDD) code. We derive
closed form expressions for the ergodic sum-rate of multi-user CDD and compare
it with the sum-capacity. We study the ergodic rate region and show that in
contrast to what is conventionally known regarding the single-user case,
transmit diversity schemes are viable candidates for high rate transmission in
multi-user systems. Finally, our theoretical findings are illustrated by
numerical simulation results.


title: Set partition statistics and q-Fibonacci numbers

abstract:
  We consider the set partition statistics ls and rb introduced by Wachs and
White and investigate their distribution over set partitions avoiding certain
patterns. In particular, we consider those set partitions avoiding the pattern
13/2, $\Pi_n(13/2)$, and those avoiding both 13/2 and 123, $\Pi_n(13/2,123)$.
We show that the distribution over $\Pi_n(13/2)$ enumerates certain integer
partitions, and the distribution over $\Pi_n(13/2,123)$ gives q-Fibonacci
numbers. These q-Fibonacci numbers are closely related to q-Fibonacci numbers
studied by Carlitz and by Cigler. We provide combinatorial proofs that these
q-Fibonacci numbers satisfy q-analogues of many Fibonacci identities. Finally,
we indicate how p,q-Fibonacci numbers arising from the bistatistic (ls, rb)
give rise to p,q-analogues of identities.


title:
Mass-Selection and the Evolution of the Morphology-Density Relation from
  z=0.8 to z=0

abstract:
  We examined the morphology-density relations for galaxy samples selected by
luminosity and by mass in each of five massive X-ray clusters from z=0.023 to
0.83 for 674 spectroscopically-confirmed members. Rest-frame optical colors and
visual morphologies were obtained primarily from Hubble Space Telescope images.
Morphology-density relations (MDR) are derived in each cluster from a complete,
luminosity-selected sample of 452 galaxies with a magnitude limit M_V <
M^{*}_{V} + 1. The change in the early-type fraction with redshift matches
previous work for massive clusters of galaxies. We performed a similar
analysis, deriving MDRs for complete, mass-selected samples of 441 galaxies
with a mass-limit of 10^{10.6} M_{\sun}. Our mass limit includes faint objects,
the equivalent of =~1 mag below L^{*} for the red cluster galaxies, and
encompasses =~70% of the stellar mass in cluster galaxies. The MDRs in the
mass-selected sample at densities of Sigma > 50 galaxies Mpc^{-2} are similar
to those in the luminosity-selected sample but show larger early-type
fractions. However, the trend with redshift in the fraction of elliptical and
S0 galaxies with masses > 10^{10.6} M_{\sun} differs significantly between the
mass- and luminosity-selected samples. The clear trend seen in the early-type
fraction from z=0 to z=~ 0.8 is not found in mass-selected samples. The
early-type galaxy fraction changes much less, and is consistent with being
constant at 92% +/- 4% at \Sigma> 500 galaxies Mpc^{-2} and 83 +/- 3% at 50 <
\Sigma < 500 galaxies Mpc^{-2}. This suggests that galaxies of mass lower than
> 10^{10.6} M_{\sun} play a significant role in the evolution of the early-type
fraction in luminosity-selected samples. (Abstract abridged)


title: On the Origin of Cosmic Magnetic Fields

abstract:
  We review the literature concerning how the cosmic magnetic fields pervading
nearly all galaxies actually got started. some observational evidence involves
the chemical abundance of the light elements Be and B, while another one is
based on strong magnetic fields seen in high red shift galaxies. Seed fields,
whose strength is of order 10^{-20} gauss, easily sprung up in the era
preceding galaxy formation. Several mechanisms are proposed to amplify these
seed fields to microgauss strengths. The standard mechanism is the Alpha-Omega
dynamo theory. It has a major difficulty that makes unlikely to provide the
sole origin. The difficulty is rooted in the fact that the total flux is
constant. This implies that flux must be removed from the galactic discs. This
requires that the field and flux be separated, for otherwise interstellar mass
must be removed from the deep galactic gravitational and then their strength
increased by the alpha omega theory.


title: A Note on the Pfaffian Integration Theorem

abstract:
  Two alternative, fairly compact proofs are presented of the Pfaffian
integration theorem that is surfaced in the recent studies of spectral
properties of Ginibre's Orthogonal Ensemble. The first proof is based on a
concept of the Fredholm Pfaffian; the second proof is purely linear-algebraic.

categories: math-ph cond-mat.dis-nn hep-th math.MP math.PR nlin.SI


title:
Multifloquet to single electronic channel transition in the transport
  properties of a resistive 1D driven disordered ring

abstract:
  We investigate the dc response of a 1D disordered ring coupled to a reservoir
and driven by a magnetic flux with a linear dependence on time. We identify two
regimes: (i) A localized or large length L regime, characterized by a dc
conductance, g_{dc}, whose probability distribution P(g_{dc}) is identical to
the one exhibited by a 1D wire of the same length L and disorder strength
placed in a Landauer setup. (ii) A "multifloquet" regime for small L and weak
coupling to the reservoir, which exhibits large currents and conductances that
can be g_{dc} > 1, in spite of the fact that the ring contains a single
electronic transmission channel. The crossover length between the multifloquet
to the single channel transport regime, L_c, is controlled by the coupling to
the reservoir.


title: Twisting gauged non-linear sigma-models

abstract:
  We consider gauged sigma-models from a Riemann surface into a Kaehler and
hamiltonian G-manifold X. The supersymmetric N=2 theory can always be twisted
to produce a gauged A-model. This model localizes to the moduli space of
solutions of the vortex equations and computes the Hamiltonian Gromov-Witten
invariants. When the target is equivariantly Calabi-Yau, i.e. when its first
G-equivariant Chern class vanishes, the supersymmetric theory can also be
twisted into a gauged B-model. This model localizes to the Kaehler quotient
X//G.


title:
The Evolution of the Field and Cluster Morphology-Density Relation for
  Mass-Selected Samples of Galaxies

abstract:
  The Sloan Digital Sky Survey (SDSS) and photometric/spectroscopic surveys in
the GOODS-South field (the Chandra Deep Field-South, CDFS) are used to
construct volume-limited, stellar mass-selected samples of galaxies at
redshifts 0<z<1. The CDFS sample at 0.6<z<1.0 contains 207 galaxies complete
down to M=4x10^10 Msol (for a ``diet'' Salpeter IMF), corresponding to a
luminosity limit for red galaxies of M_B=-20.1. The SDSS sample at
0.020<z<0.045 contains 2003 galaxies down to the same mass limit, which
corresponds to M_B=-19.3 for red galaxies. Morphologies are determined with an
automated method, using the Sersic parameter n and a measure of the residual
from the model fits, called ``bumpiness'', to distinguish different
morphologies. These classifications are verified with visual classifications.
In agreement with previous studies, 65-70% of the galaxies are located on the
red sequence, both at z~0.03 and at z~0.8. Similarly, 65-70% of the galaxies
have n>2.5. The fraction of E+S0 galaxies is 43+/-3%$ at z~0.03 and 48+/-7% at
z~0.8, i.e., it has not changed significantly since z~0.8. When combined with
recent results for cluster galaxies in the same redshift range, we find that
the morphology-density relation for galaxies more massive than 0.5M* has
remained constant since at least z~0.8. This implies that galaxies evolve in
mass, morphology and density such that the morphology-density relation does not
change. In particular, the decline of star formation activity and the
accompanying increase in the stellar mass density of red galaxies since z~1
must happen without large changes in the early-type galaxy fraction in a given
environment.


title:
Evolutionary Fitting Methods for the Extraction of Mass Spectra in
  Lattice Field Theory

abstract:
  We present an application of evolutionary algorithms to the curve-fitting
problems commonly encountered when trying to extract particle masses from
correlators in Lattice QCD. Harnessing the flexibility of evolutionary methods
in global optimization allows us to dynamically adapt the number of states to
be fitted along with their energies so as to minimize overall \chi^2/(d.o.f.),
leading to a promising new way of extracting the mass spectrum from measured
correlation functions.


title:
Nonthermal steady states after an interaction quench in the
  Falicov-Kimball model

abstract:
  We present the exact solution of the Falicov-Kimball model after a sudden
change of its interaction parameter using non-equilibrium dynamical mean-field
theory. For different interaction quenches between the homogeneous metallic and
insulating phases the system relaxes to a non-thermal steady state on time
scales on the order of hbar/bandwidth, showing collapse and revival with an
approximate period of h/interaction if the interaction is large. We discuss the
reasons for this behavior and provide a statistical description of the final
steady state by means of generalized Gibbs ensembles.


title: The Evolving Faint-End of the Luminosity Function

abstract:
  We investigate the evolution of the faint-end slope of the luminosity
function, $\alpha$, using semi-analytical modeling of galaxy formation. In
agreement with observations, we find that the slope can be fitted well by
$\alpha (z) =a+b z$, with a=-1.13 and b=-0.1. The main driver for the evolution
in $\alpha$ is the evolution in the underlying dark matter mass function.
Sub-L_* galaxies reside in dark matter halos that occupy a different part of
the mass function. At high redshifts, this part of the mass function is steeper
than at low redshifts and hence $\alpha$ is steeper. Supernova feedback in
general causes the same relative flattening with respect to the dark matter
mass function. The faint-end slope at low redshifts is dominated by field
galaxies and at high redshifts by cluster galaxies. The evolution of
$\alpha(z)$ in each of these environments is different, with field galaxies
having a slope b=-0.14 and cluster galaxies b=-0.05. The transition from
cluster-dominated to field-dominated faint-end slope occurs roughly at a
redshift $z_* \sim 2$, and suggests that a single linear fit to the overall
evolution of $\alpha(z)$ might not be appropriate. Furthermore, this result
indicates that tidal disruption of dwarf galaxies in clusters cannot play a
significant role in explaining the evolution of $\alpha(z)$ at z< z_*. In
addition we find that different star formation efficiencies a_* in the
Schmidt-Kennicutt-law and supernovae-feedback efficiencies $\epsilon$ generally
do not strongly influence the evolution of $\alpha(z)$.


title: Shadow vacuum alignment and dark energy

abstract:
  In a recent model of dark energy (with several phenomenological
consequences), the universe is assumed to be trapped in a false vacuum with an
energy density of the order of (10^{-3} eV)^4, mimicking the presently
successful $\Lambda CDM$ scenario. This involves a new gauge group SU(2)_Z,
{\em the shadow sector}, which becomes strong at a scale $\Lambda_Z \sim
10^{-3} eV$. The model is described by the SU(2)_Z instanton-induced potential
of an axion-like scalar field, a_Z, with two degenerate vacuua. The false
(metastable) vacuum appears as a result of an phenomenological (ad-hoc) soft
breaking term linear in a_Z which explicitely breaks that degeneracy. In this
paper, we discuss a possible dynamical origin for this soft breaking term as
coming from the alignment of the vacuum along a direction in which the
condensate of the shadow fermions, $<\bar{\psi}^{(Z)}_{i} i \gamma_{5}
\psi^{(Z)}_{i}>$ which breaks spontaneously both P and CP, is non-vanishing.
The present universe lives in a vacuum which violates both P and CP in the
shadow SU(2)_Z sector!


title: Distributed Compression and Multiparty Squashed Entanglement

abstract:
  We study a protocol in which many parties use quantum communication to
transfer a shared state to a receiver without communicating with each other.
This protocol is a multiparty version of the fully quantum Slepian-Wolf
protocol for two senders and arises through the repeated application of the
two-sender protocol. We describe bounds on the achievable rate region for the
distributed compression problem. The inner bound arises by expressing the
achievable rate region for our protocol in terms of its vertices and extreme
rays and, equivalently, in terms of facet inequalities. We also prove an outer
bound on all possible rates for distributed compression based on the multiparty
squashed entanglement, a measure of multiparty entanglement.


title: Detection of circumstellar material in a normal Type Ia Supernova

abstract:
  Type Ia supernovae are thought to be thermonuclear explosions of accreting
white dwarfs that reach a critical mass limit. Despite their importance as
cosmological distance indicators, the nature of their progenitors has remained
controversial. Here we report the detection of circumstellar material in a
normal Type Ia supernova. The expansion velocities, densities and dimensions of
the circumstellar envelope indicate that this material was ejected from the
progenitor system. The relatively low expansion velocities appear to favor a
progenitor system where a white dwarf accretes material from a companion star
which is in the red-giant phase at the time of explosion.


title: Nonadiabatic charged spherical gravitational collapse

abstract:
  We present a complete set of the equations and matching conditions required
for the description of physically meaningful charged, dissipative, spherically
symmetric gravitational collapse with shear. Dissipation is described with both
free-streaming and diffusion approximations. The effects of viscosity are also
taken into account. The roles of different terms in the dynamical equation are
analyzed in detail. The dynamical equation is coupled to a causal transport
equation in the context of Israel-Stewart theory. The decrease of the inertial
mass density of the fluid, by a factor which depends on its internal
thermodynamic state, is reobtained, with the viscosity terms included. In
accordance with the equivalence principle, the same decrease factor is obtained
for the gravitational force term. The effect of the electric charge on the
relation between the Weyl tensor and the inhomogeneity of energy density is
discussed.


title:
Neutron-skin thickness of finite nuclei in relativistic mean-field
  models with chiral limits

abstract:
  We study several structure properties of finite nuclei using relativistic
mean-field Lagrangians constructed according to the Brown-Rho scaling due to
the chiral symmetry restoration at high densities. The models are consistent
with current experimental constraints for the equations of state of symmetric
matter at both normal and supra-normal densities and of asymmetric matter at
sub-saturation densities. It is shown that these models can successfully
describe the binding energies and charge radii of finite nuclei. Compared to
calculations with usual relativistic mean-field models, these models give a
reduced thickness of neutron skin in ^{208}Pb between 0.17 fm and 0.21 fm. The
reduction of the predicted neutron skin thickness is found to be due to not
only the softening of the symmetry energy but also the scaling property of
$\rho $ meson required by the partial restoration of chiral symmetry.


title:
Random perturbations of stochastic chains with unbounded variable length
  memory

abstract:
  We consider binary infinite order stochastic chains perturbed by a random
noise. This means that at each time step, the value assumed by the chain can be
randomly and independently flipped with a small fixed probability. We show that
the transition probabilities of the perturbed chain are uniformly close to the
corresponding transition probabilities of the original chain. As a consequence,
in the case of stochastic chains with unbounded but otherwise finite variable
length memory, we show that it is possible to recover the context tree of the
original chain, using a suitable version of the algorithm Context, provided
that the noise is small enough.


title:
Outer boundary conditions for Einstein's field equations in harmonic
  coordinates

abstract:
  We analyze Einstein's vacuum field equations in generalized harmonic
coordinates on a compact spatial domain with boundaries. We specify a class of
boundary conditions which is constraint-preserving and sufficiently general to
include recent proposals for reducing the amount of spurious reflections of
gravitational radiation. In particular, our class comprises the boundary
conditions recently proposed by Kreiss and Winicour, a geometric modification
thereof, the freezing-Psi0 boundary condition and the hierarchy of absorbing
boundary conditions introduced by Buchman and Sarbach. Using the recent
technique developed by Kreiss and Winicour based on an appropriate reduction to
a pseudo-differential first order system, we prove well posedness of the
resulting initial-boundary value problem in the frozen coefficient
approximation. In view of the theory of pseudo-differential operators it is
expected that the full nonlinear problem is also well posed. Furthermore, we
implement some of our boundary conditions numerically and study their
effectiveness in a test problem consisting of a perturbed Schwarzschild black
hole.


title:
Study of B0 -> pi0 pi0, B -> pi pi0, and B -> K pi0 Decays, and Isospin
  Analysis of B -> pipi Decays

abstract:
  We present updated measurements of the branching fractions and CP asymmetries
for B0 -> pi0 pi0, B+ -> pi+ pi0, and B+ -> K+ pi0. Based on a sample of 383 x
10^6 Upsilon(4S) -> B Bbar decays collected by the BABAR detector at the PEP-II
asymmetric-energy B factory at SLAC, we measure B(B0 -> pi0 pi0) =(1.47 +/-
0.25 +/- 0.12) x 10^-6, B(B+ -> pi+ pi0)= (5.02 +/- 0.46 +/- 0.29) x 10^-6, and
B(B+ -> K+ pi0) = (13.6 +/- 0.6 +/- 0.7) x 10^-6. We also measure the CP
asymmetries C(pi0 pi0) = -0.49 +/- 0.35 +/- 0.05, A(pi+ pi0) = 0.03 +/- 0.08
+/- 0.01, and A(K+ pi0) = 0.030 +/- 0.039 +/- 0.010. Finally, we present bounds
on the CKM angle $\alpha$ using isospin relations.


title:
High resolution X-ray scattering studies of structural phase transitions
  in underdoped La$_{2-x}$Ba$_x$CuO$_4$

abstract:
  We have studied structural phase transitions in high quality underdoped
La$_{2-x}$Ba$_x$CuO$_4$ single crystals using high resolution x-ray scattering
techniques. Critical properties associated with the continuous High Temperature
Tetragonal (HTT, $I4/mmm$) to Middle Temperature Orthorhombic (MTO, $Cmca$)
phase transition were investigated in single crystal samples with x=0.125,
0.095, and 0.08 and we find that all behavior is consistent with three
dimensional XY criticality, as expected from theory. Power law behavior in the
orthorhombic strain, 2(a-b)/(a+b), is observed over a remarkably wide
temperature range, spanning most of the MTO regime in the phase diagram. Low
temperature measurements investigating the Low Temperature Tetragonal (LTT,
$P4_{2}/ncm$) phase, below the strongly discontinuous MTO$\to$LTT phase
transition, in x=0.125 and x=0.095 samples show that the LTT phase is
characterized by relatively broad Bragg scattering, compared with that observed
at related wavevectors in the HTT phase. This shows that the LTT phase is
either an admixture of tetragonal and orthorhombic phases, or that it is
orthorhombic with very small orthorhombic strain, consistent with the ``less
orthorhombic" low temperature structure previously reported in mixed
La$_{2-x}$Sr$_{x-y}$Ba$_y$CuO$_4$ single crystals. We compare the complex
temperature-composition phase diagram for the location of structural and
superconducting phase transitions in underdoped La$_{2-x}$Ba$_x$CuO$_4$ and
find good agreement with results obtained on polycrystalline samples.


title:
Dielectric spectroscopy in benzophenone: The beta relaxation and its
  relation to the mode-coupling Cole-Cole peak

abstract:
  We report a thorough characterization of the glassy dynamics of benzophenone
by broadband dielectric spectroscopy. We detect a well pronounced beta
relaxation peak developing into an excess wing with increasing temperature. A
previous analysis of results from Optical-Kerr-effect measurements on this
material within the mode coupling theory revealed a high-frequency Cole-Cole
peak. We address the question if this phenomenon also may explain the
Johari-Goldstein beta relaxation, a so far unexplained spectral feature
inherent to glass-forming matter, mainly observed in dielectric spectra. Our
results demonstrate that according to the present status of theory, both
spectral features seem not to be directly related.


title:
Testing Chameleon Theories with Light Propagating through a Magnetic
  Field

abstract:
  It was recently argued that the observed PVLAS anomaly can be explained by
chameleon field theories in which large deviations from Newton's law can be
avoided. Here we present the predictions for the dichroism and the
birefringence induced in the vacuum by a magnetic field in these models. We
show that chameleon particles behave very differently from standard axion-like
particles (ALPs). We find that, unlike ALPs, the chameleon particles are
confined within the experimental set-up. As a consequence, the birefringence is
always bigger than the dichroism in PVLAS-type experiments.


title:
Determination of the mass of the neutron star in SMC X-1, LMC X-4 and
  Cen X-3 with VLT/UVES

abstract:
  We present the results of a spectroscopic monitoring campaign of the OB-star
companions to the eclipsing X-ray pulsars SMC X-1, LMC X-4 and Cen X-3.
High-resolution optical spectra obtained with UVES on the ESO Very Large
Telescope are used to determine the radial-velocity orbit of the OB
(super)giants with high precision. The excellent quality of the spectra
provides the opportunity to measure the radial-velocity curve based on
individual lines, and to study the effect of possible distortions of the line
profiles due to e.g. X-ray heating on the derived radial-velocity amplitude.
Several spectral lines show intrinsic variations with orbital phase. The
magnitude of these variations depends on line strength, and thus provides a
criterion to select lines that do not suffer from distortions. The undistorted
lines show a larger radial-velocity amplitude than the distorted lines,
consistent with model predictions. Application of our line-selection criteria
results in a mean radial-velocity amplitude K(Opt) of 20.2 +/- 1.1, 35.1 +/-
1.5, and 27.5 +/- 2.3 km/s (1 sigma errors), for the OB companion to SMC X-1,
LMC X-4 and Cen X-3, respectively. Adding information on the projected
rotational velocity of the OB companion (derived from our spectra), the
duration of X-ray eclipse and orbital parameters of the X-ray pulsar (obtained
from literature), we arrive at a neutron star mass of 1.06^{+0.11}_{-0.10},
1.25^{+0.11}_{-0.10} and 1.34^{+0.16}_{-0.14} M{sun} for SMC X-1, LMC X-4 and
Cen X-3, respectively. The mass of SMC X-1 is near the minimum mass (~1 M{sun})
expected for a neutron star produced in a supernova. We discuss the
implications of the measured mass distribution on the neutron-star formation
mechanism, in relation to the evolutionary history of the massive binaries.


title: Deformed strings in the Heisenberg model

abstract:
  We investigate solutions to the Bethe equations for the isotropic S = 1/2
Heisenberg chain involving complex, string-like rapidity configurations of
arbitrary length. Going beyond the traditional string hypothesis of undeformed
strings, we describe a general procedure to construct eigenstates including
strings with generic deformations, discuss general features of these solutions,
and provide a number of explicit examples including complete solutions for all
wavefunctions of short chains. We finally investigate some singular cases and
show from simple symmetry arguments that their contribution to zero-temperature
correlation functions vanishes.


title: Generalized kinetic equations for charge carriers in graphene

abstract:
  A system of generalized kinetic equations for the distribution functions of
two-dimensional Dirac fermions scattered by impurities is derived in the Born
approximation with respect to short-range impurity potential. It is proven that
the conductivity following from classical Boltzmann equation picture, where
electrons or holes have scattering amplitude reduced due chirality, is
justified except for an exponentially narrow range of chemical potential near
the conical point. When in this range, creation of infinite number of
electron-hole pairs related to quasi-relativistic nature of electrons in
graphene results in a renormalization of minimal conductivity as compared to
the Boltzmann term and logarithmic corrections in the conductivity similar to
the Kondo effect.


title: Piezomagnetic Quantum Dots

abstract:
  We study the influence of deformations on magnetic ordering in quantum dots
doped with magnetic impurities. The reduction of symmetry and the associated
deformation from circular to elliptical quantum confinement lead to the
formation of piezomagnetic quantum dots. The strength of elliptical deformation
can be controlled by the gate voltage to change the magnitude of magnetization,
at a fixed number of carriers and in the absence of applied magnetic field. We
reveal a reentrant magnetic ordering with the increase of elliptical
deformation and suggest that the piezomagnetic quantum dots can be used as
nanoscale magnetic switches.