title:
Angular momentum transport by internal gravity waves. IV - Wave
  generation by surface convection zone, from the pre-main sequence to the
  early-AGB in intermediate mass stars

abstract:
  This is the fourth in a series of papers that deal with angular momentum
transport by internal gravity waves in stellar interiors. Here, we want to
examine the potential role of waves in other evolutionary phases than the main
sequence. We study the evolution of a 3Msun Population I model from the
pre-main sequence to the early-AGB phase and examine whether waves can lead to
angular momentum redistribution and/or element diffusion at the external
convection zone boundary. We find that, although waves produced by the surface
convection zone can be ignored safely for such a star during the main sequence,
it is not the case for later evolutionary stages. In particular, angular
momentum transport by internal waves could be quite important at the end of the
sub-giant branch and during the early-AGB phase. Wave-induced mixing of
chemicals is expected during the early-AGB phase.


title:
The relative roles of divergence and velocity slip in the stability of
  plane channel flow

abstract:
  Wall slip and wall divergence are known to have large and opposing effects on
the stability of flow in a two-dimensional channel. While divergence hugely
destabilises, slip dramatically stabilizes the linear mode. In a non-parallel
stability analysis, we study a combination of these two effects, since both
will coexist in small-scale flows with wall roughness. Our main results are (i)
that the stabilising effect of slip is reversed at higher angles of divergence,
(ii) transient growth of disturbances is unaffected by either wall-divergence,
or by slip at any divergence. Moreover, at the Reynolds numbers relevant here,
transient growth is too low to be a significant player in transition to
turbulence, which is more likely to be driven by linear instability.


title: Renyi entropies of a black hole from Hawking radiation

abstract:
  Renyi entropies of a black hole are evaluated by counting the states of the
Hawking radiation which fills a thin shell surrounding the horizon. The width
of the shell is determined from its energy content and the corresponding mass
defect. The Bekenstein-Hawking formula for the entropy of the black hole is
correctly reproduced.


title:
General analysis of two--photon exchange in elastic electron--$^4He$
  scattering and $e^++e^-\to \pi^++\pi^-.$

abstract:
  Using a general parametrization of the spin structure of the matrix element
for the elastic $e^-+^4He$ scattering and for the annihilation $e^++e^-\to
\pi^++\pi^-$ reactions in terms of two complex amplitudes, we derive general
properties of the observables in presence of two--photon exchange. We show that
this mechanism induces a specific dependence of the differential cross section
on the angle of the emitted particle. We reanalyze the existing experimental
data on the differential cross section, for elastic electron scattering on
$^4He$, in the light of this result.


title: k-deformed Poincare algebras and quantum Clifford-Hopf algebras

abstract:
  The Minkowski spacetime quantum Clifford algebra structure associated with
the conformal group and the Clifford-Hopf alternative k-deformed quantum
Poincare algebra is investigated in the Atiyah-Bott-Shapiro mod 8 theorem
context. The resulting algebra is equivalent to the deformed anti-de Sitter
algebra U_q(so(3,2)), when the associated Clifford-Hopf algebra is taken into
account, together with the associated quantum Clifford algebra and a (not
braided) deformation of the periodicity Atiyah-Bott-Shapiro theorem.


title: A note on boundary-layer friction in baroclinic cyclones

abstract:
  The interaction between extratropical cyclones and the underlying boundary
layer has been a topic of recent discussion in papers by Adamson et. al. (2006)
and Beare (2007). Their results emphasise different mechanisms through which
the boundary layer dynamics may modify the growth of a baroclinic cyclone. By
using different sea-surface temperature distributions and comparing the
low-level winds, the differences are exposed and both of the proposed
mechanisms appear to be acting within a single simulation.


title: Metallicity Effects in PDRs

abstract:
  Almost all properties of a photodissociation region (PDR) depend on its
metallicity. The heating and cooling efficiencies that determine the
temperature of the gas and dust, the dust composition, as well as the elemental
abundances that influence the chemical structure of the PDR are just three
examples that demonstrate the importance of metallicity effects in PDRs. PDRs
are often associated with sites of star formation. If we want to understand the
star formation history of our own Galaxy and of distant low-metallicity objects
we need to understanding how metallicity acts on PDR physics and chemistry.


title: Electron-phonon interaction in the lamellar cobaltate Na$_x$CoO$_2$

abstract:
  We study theoretically and experimentally the dependence of the
electron-phonon interaction in Na$_x$CoO$_2$ on the sodium concentration $x$.
For the two oxygen phonon modes found in Raman experiments, $A_{1g}$ and
$E_{1g}$, we calculate the matrix elements of the electron-phonon interaction.
Analyzing the feedback effect of the conduction electrons on the phonon
frequency we compare the calculated and experimentally observed doping
dependence of the $A_{1g}$ mode. Furthermore, due to the momentum dependence of
the electron-phonon coupling for the $E_{1g}$ symmetry we find no
renormalization of the corresponding phonon frequency which agrees with
experiment. Our results shed light on the possible importance of the
electron-phonon interaction in this system.


title: Precision Tests of Electroweak Interactions

abstract:
  The status of the precision tests of the electroweak interactions is reviewed
in this paper. An emphasis is put on the Standard Model analysis based on
measurements at LEP/SLC and the Tevatron. The results of the measurements of
the electroweak mixing angle in the NuTeV experiment and the future prospects
are discussed.


title: Connectedness in the Pluri-fine Topology

abstract:
  We study connectedness in the pluri-fine topology on $\CC^n$ and obtain the
following results. If $\Omega$ is a pluri-finely open and pluri-finely
connected set in $\CC^n$ and $E\subset\CC^n$ is pluripolar, then
$\Omega\setminus E$ is pluri-finely connected. The proof hinges on precise
information about the structure of open sets in the pluri-fine topology: Let
$\Omega$ be a pluri-finely open subset of $\CC^{n}$. If $z$ is any point in
$\Omega$, and $L$ is a complex line passing through $z$, then obviously $\Omega
\cap L$ is a finely open neighborhood of $z$ in $L$. Now let $C_L$ denote the
finely connected component of $z$ in $\Omega\cap L$. Then $\cup_{L\ni z} C_L$
is a pluri-finely connected neighborhood of $z$. As a consequence we find that
if $v$ is a finely plurisubharmonic function defined on a pluri-finely
connected pluri-finely open set, then $v= -\infty$ on a pluri-finely open
subset implies $v\equiv -\infty$.


title:
Pion electromagnetic charge radii and rho-meson mass shift at finite
  density

abstract:
  We investigate the pion electromagnetic charge radii and mass dropping of the
rho meson at finite density. We first calculate the pion charge radii within
the framework of the nonlocal chiral quark model from the instanton vacuum both
at zero and finite densities. In order to relate the change of the pion charge
radius to that of the rho-meson mass at finite density, we employ the
vector-meson dominance for the pion electromagnetic form factor. It turns out
that the pion charge radius is getting larger as the quark chemical potential
increases. As a result, the rho-meson mass falls off as the quark chemical
potential grows and is found to be dropped by about 10% at normal nuclear
matter density: m*_rho/m_rho ~ 1 - 0.12 mu_B/mu_0, which is compatible to the
results of the measurement at the KEK recently.


title:
The study of threshold behaviour of effective potential for
  $^{6}$Li+$^{58,64}$Ni systems

abstract:
  The elastic scattering for $^6$Li+$^{64}$Ni system was measured in the
bombarding energy range of 13 MeV $\leq$ $E_{lab}$ $\leq$ 26 MeV. A
phenomenological optical model analysis was performed and the behaviour of the
surface strengths of the potential components with decreasing energy was
extracted. A further analysis of the measured angular distributions, along with
the existing data for $^6$Li+$^{58}$Ni, was performed with two different model
potentials - one with the folded potential normalized with a complex factor
(OMP1) and the other with a {\it hybrid} potential composed of a renormalized
folded real and a phenomenological imaginary (OMP2) potential components - were
used in the calculation. All the model potentials predict similar energy
dependent behaviour for the interaction potential around the barrier. The
observed energy dependence of the strengths of the real and imaginary
potentials corroborate with the dispersion relation prediction for both the
$^6$Li+$^{64}$Ni and $^6$Li+$^{58}$Ni systems. Though the evidence of breakup
is distinct in the energy variation of the potential strengths, close to the
barrier the variation is more in the line of conventional threshold anomaly.
Also the threshold behaviour of the interaction potential does not indicate any
distinct isotopic dependence.


title: Refracted Levy processes

abstract:
  Motivated by classical considerations from risk theory, we investigate
boundary crossing problems for refracted L\'evy processes. The latter is a
L\'evy process whose dynamics change by subtracting off a fixed linear drift
(of suitable size) whenever the aggregate process is above a pre-specified
level. More formally, whenever it exists, a refracted L\'evy process is
described by the unique strong solution to the stochastic differential equation
\[ \D U_t = - \delta \mathbf{1}_{\{U_t >b\}}\D t + \D X_t \] where $X=\{X_t
:t\geq 0\}$ is a L\'evy process with law $\mathbb{P}$ and $b, \delta\in
\mathbb{R}$ such that the resulting process $U$ may visit the half line
$(b,\infty)$ with positive probability. We consider in particular the case that
$X$ is spectrally negative and establish a suite of identities for the case of
one and two sided exit problems. All identities can be written in terms of the
$q$-scale function of the driving L\'evy process and its perturbed version
describing motion above the level $b$. We remark on a number of applications of
the obtained identities to (controlled) insurance risk processes.


title:
Cosmic Ray Velocity and Electric Charge Measurements in the AMS
  experiment

abstract:
  The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed
to measure charged cosmic ray spectra with energies up to the TeV region and
with high energy photon detection capability up to few hundred GeV. It will be
installed on the International Space Station (ISS) in 2008 and will operate for
more than three years. Due to its large acceptance, the flight duration and the
state-of-art of particle identification techniques, AMS will have a remarkable
sensitivity on antimatter and dark matter searches. The addition of different
detector systems provide AMS with complementary and redundant electric charge
and velocity measurements. The velocity of singly charged particles is expected
to be measured with a precision of 0.1% and charge separation up to iron is
attainable. The AMS capability of measuring a large range of electric charges
and accurate velocities, will largely contribute to a better understanding of
cosmic ray production, acceleration and propagation mechanisms in the galaxy.


title:
Discovery of a Giant Stellar Tidal Stream Around the Disk Galaxy NGC
  4013

abstract:
  We report the discovery of a giant, loop-like stellar structure around the
edge-on spiral galaxy NGC 4013. This arcing feature extends 6 arcmin (~26 kpc
in projected distance) northeast from the center and 3 arcmin (~=12 kpc) from
the disk plane; likely related features are also apparent on the southwest side
of the disk, extending to 4 arcmin (~17 kpc). The detection of this low
surface-brightness muR= 27.0+0.3-0.2 mag/sqarcsec) structure is independently
confirmed in three separate datasets from three different telescopes.
  Although its true three dimensional geometry is unknown, the sky- projected
morphology of this structure displays a match with the theoretical predictions
for the edge-on, projected view of a stellar tidal streams of a dwarf satellite
moving in a low inclined (~25deg), nearly circular orbit. Using the recent
model of the Monoceros tidal stream in the Milky Way by Penarrubia et al. as
template, we find that the progenitor system may have been a galaxy with an
initial mass 6*10^8 Msun, of which current position and final fate is unknown.
According to this simulation, the tidal stream may be approximately ~2.8 Gyr of
age.
  Our results demonstrate that NGC 4013, previously considered a prototypical
isolated disk galaxy in spite of having one of the most prominent HI warps
detected thus far, may have in fact suffered a recent minor merger. This
discovery highlights that undisturbed disks at high surface brightness levels
in the optical but warped in HI maps may in fact reveal complex signatures of
recent accretion events in deep photometric surveys.


title: Isotopic mass separation with the RICH detector of the AMS Experiment

abstract:
  The Alpha Magnetic Spectrometer (AMS) to be installed on the International
Space Station (ISS) will be equipped with a proximity focusing Ring Imaging
Cerenkov detector (RICH). Reconstruction of the Cerenkov angle and the electric
charge with RICH are discussed. A likelihood method for the Cerenkov angle
reconstruction was applied leading to a velocity determination for protons with
a resolution around 0.1%. The electric charge reconstruction is based on the
counting of the number of photoelectrons and on an overall efficiency
estimation on an event-by-event basis. The isotopic mass separation of helium
and beryllium is presented.


title: Current Fluctuations in the exclusion process and Bethe Ansatz

abstract:
  We use the Bethe Ansatz to derive analytical expressions for the current
statistics in the asymmetric exclusion process with both forward and backward
jumps. The Bethe equations are highly coupled and this fact has impeded their
use to derive exact results for finite systems. We overcome this technical
difficulty by a reformulation of the Bethe equations into a one variable
polynomial problem, akin to the functional Bethe Ansatz. The perturbative
solution of this equation leads to the cumulants of the current. We calculate
here the first two orders and derive exact formulae for the mean value of the
current and its fluctuations.


title: Quantum computing of semiclassical formulas

abstract:
  We show that semiclassical formulas such as the Gutzwiller trace formula can
be implemented on a quantum computer more efficiently than on a classical
device. We give explicit quantum algorithms which yield quantum observables
from classical trajectories, and which alternatively test the semiclassical
approximation by computing classical actions from quantum evolution. The gain
over classical computation is in general quadratic, and can be larger in some
specific cases.


title:
The embedded cluster DBSB48 in the nebula Hoffleit18: comparison with
  Trumpler14

abstract:
  We derive fundamental parameters of the embedded cluster DBSB48 in the
southern nebula Hoffleit18 and the very young open cluster Trumpler14, by means
of deep JHKs infrared photometry. We build colour-magnitude and colour-colour
diagrams to derive reddening and age, based on main sequence and pre-main
sequence distributions. Radial stellar density profiles are used to study
cluster structure and guide photometric diagram extractions. Field-star
decontamination is applied to uncover the intrinsic cluster sequences in the
diagrams. Ages are inferred from K-excess fractions. A prominent
pre-main-sequence population is present in DBSB48, and the K-excess fraction
f_K=55+/-6% gives an age of 1.1+/-0.5Myr. A mean reddening of A_K_s=0.9+/-0.03
was found, corresponding to $A_V=8.2\pm0.3$. The cluster CMD is consistent with
the far kinematic distance of 5 kpc for Hoffleit 18. For Trumpler 14 we derived
similar parameters as in previous studies in the optical, in particular an age
of $1.7\pm0.7$ Myr. The fraction of stars with infrared excess in Trumpler 14
is $f_K=28\pm4%$. Despite the young ages, both clusters are described by a King
profile with core radii $\rc=0.46\pm0.05$ pc and $\rc=0.35\pm0.04$ pc,
respectively for DBSB 48 and Trumpler 14. Such cores are smaller than those of
typical open clusters. Small cores are probably related to the cluster
formation and/or parent molecular cloud fragmentation. In DBSB 48, the
magnitude extent of the upper main sequence is $\Delta \ks\approx2$ mag, while
in Trumpler 14 it is $\Delta \ks\approx5$ mag, consistent with the estimated
ages.


title:
Admissibility of kneading sequences and structure of Hubbard trees for
  quadratic polynomials

abstract:
  Hubbard trees are invariant trees connecting the points of the critical
orbits of postcritically finite polynomials. Douady and Hubbard \cite{Orsay}
introduced these trees and showed that they encode the essential information of
Julia sets in a combinatorial way. The itinerary of the critical orbit within
the Hubbard tree is encoded by a (pre)periodic sequence on $\{\0,\1\}$ called
\emph{kneading sequence}.
  We prove that the kneading sequence completely encodes the Hubbard tree and
its dynamics, and we show how to reconstruct the tree and in particular its
branch points (together with their periods, their relative posititions, their
number of arms and their local dynamics) in terms of the kneading sequence
alone.
  Every kneading sequence gives rise to an abstract Hubbard tree, but not every
kneading sequence occurs in real dynamics or in complex dynamics. Milnor and
Thurston \cite{MT} classified which kneading sequences occur in real dynamics;
we do the same for complex dynamics in terms of a complex \emph{admissibility
condition}. This complex admissibility condition fails if and only if the
abstract Hubbard tree has a so-called \emph{evil} periodic branch point that is
incompatible with local homeomorphic dynamics on the plane.


title:
Energy Spectrum of a 2D Dirac Oscillator in the Presence of the
  Aharonov-Bohm Effect

abstract:
  We determine the energy spectrum and the corresponding eigenfunctions of a 2D
Dirac oscillator in the presence of Aharonov-Bohm (AB) effect . It is shown
that the energy spectrum depends on the spin of particle and the AB magnetic
flux parameter. Finally, when the irregular solution occurs it is shown that
the energy takes particular values. The nonrelativistic limit is also
considered.


title: A Molecular Model for Communication through a Secrecy System

abstract:
  Codes have been used for centuries to convey secret information.To a
cryptanalyst, the interception of a code is only the first step in recovering a
secret message.Deoxyribonucleic acid (DNA) is a biological and molecular
code.Through the work of Marshall Nirenberg and others, DNA is now understood
to specify for amino acids in triplet codes of bases.The possibilty of DNA
encoding secret information in a natural language is explored, since a code is
expected to have a distinct mathematical solution.


title: Symplectic embeddings of 4-dimensional ellipsoids

abstract:
  We show how to reduce the problem of symplectically embedding one
4-dimensional rational ellipsoid into another to a problem of embedding
disjoint unions of balls into appropriate blow ups of \C P^2. For example, the
problem of embedding the ellipsoid E(1,k) into a ball B is equivalent to that
of embedding k disjoint equal balls into \C P^2, and so can be solved by the
work of Gromov, McDuff--Polterovich and Biran. (Here k is the ratio of the area
of the major axis to that of the minor axis.) As a consequence we show that the
ball may be fully filled by the ellipsoid E(1,k) for k=1,4 and all k\ge 9, thus
answering a question raised by Hofer.


title:
Stochastic maximum principle for optimal control problem of backward
  systems with terminal condition in L1

abstract:
  We consider a stochastic control problem, where the control domain is convex
and the system is governed by a nonlinear backward stochastic differential
equation. With a L1 terminal data, we derive necessary optimality conditions in
the form of stochastic maximum principle.


title: Radiative strength function in 96Mo reanalyzed

abstract:
  The radiative strength functions of 96Mo have been reanalyzed. The enhanced
gamma strength for E_gamma < 3 - 4 MeV is confirmed.


title:
The strict and relaxed stochastic maximum principle for optimal control
  problem of backward systems

abstract:
  We consider a stochastic control problem where the set of controls is not
necessarily convex and the system is governed by a nonlinear backward
stochastic differential equation. We establish necessary as well as sufficient
conditions of optimality for two models. The first concerns the strict
(classical) controls. The second is an extension of the first to relaxed
controls, who are a measure valued processes.


title:
A general stochastic maximum principle for mixed relaxed-singular
  control problems

abstract:
  We consider in this paper, mixed relaxed-singular stochastic control
problems, where the control variable has two components, the first being
measure-valued and the second singular. The control domain is not necessarily
convex and the system is governed by a nonlinear stochastic differential
equation, in which the measure-valued part of the control enters both the drift
and the diffusion coefficients. We establish necessary optimality conditions,
of the Pontryagin maximum principle type, satisfied by an optimal
relaxed-singular control, which exist under general conditions on the
coefficients. The proof is based on the strict singular stochastic maximum
principle established by Bahlali-Mezerdi, Ekeland's variational principle and
some stability properties of the trajectories and adjoint processes with
respect to the control variable.


title: Swift heavy ion irradiation of SrTiO$_3$ under grazing incidence

abstract:
  The irradiation of SrTiO$_3$ single crystals with swift heavy ions leads to
modifications of the surface. The details of the morphology of these
modifications depends strongly on the angle of incidence and can be
characterized by atomic force microscopy. At glancing angles, discontinuous
chains of nanosized hillocks appear on the surface. The latent track radius can
be determined from the variation of the length of the chains with the angle of
incidence. This radius is material specific and allows the calculation of the
electron-phonon-coupling constant for SrTiO$_3$. We show that a theoretical
description of the nanodot creation is possible within a two-temperature model
if the spatial electron density is taken into account. The appearance of
discontinuous features can be explained easily within this model, but it turns
out that the electronic excitation dissipates on a femtosecond time scale and
thus too rapidly to feed sufficient energy into the phonon system in order to
induce a thermal melting process. We demonstrate that this can be solved if the
temperature dependent diffusion coefficient is introduced into the model.


title:
Quantum cosmological solutions: their dependence on the choice of gauge
  conditions and physical interpretation

abstract:
  In "extended phase space" approach to quantum geometrodynamics numerical
solutions to Schrodinger equation corresponding to various choice of gauge
conditions are obtained for the simplest isotropic model. The "extended phase
space" approach belongs to those appeared in the last decade in which, as a
result of fixing a reference frame, the Wheeler - DeWitt static picture of the
world is replaced by evolutionary quantum geometrodynamics. Some aspects of
this approach were discussed at two previous PIRT meetings. We are interested
in the part of the wave function depending on physical degrees of freedom.
Three gauge conditions having a clear physical meaning are considered. They are
the conformal time gauge, the gauge producing the appearance of Lambda-term in
the Einstein equations, and the one covering the two previous cases as
asymptotic limits. The interpretation and discussion of the obtained solutions
is given.


title:
Spectral weight redistribution in strongly correlated bosons in optical
  lattices

abstract:
  We calculate the single-particle spectral function for the one-band
Bose-Hubbard model within the random phase approximation (RPA). In the strongly
correlated superfluid, in addition to the gapless phonon excitations, we find
extra gapped modes which become particularly relevant near the superfluid-Mott
quantum phase transition (QPT). The strength in one of the gapped modes, a
precursor of the Mott phase, grows as the QPT is approached and evolves into a
hole (particle) excitation in the Mott insulator depending on whether the
chemical potential is above (below) the tip of the lobe. The sound velocity of
the Goldstone modes remains finite when the transition is approached at a
constant density, otherwise, it vanishes at the transition. It agrees well with
Bogoliubov theory except close to the transition. We also calculate the spatial
correlations for bosons in an inhomogeneous trapping potential creating
alternating shells of Mott insulator and superfluid. Finally, we discuss the
capability of the RPA approximation to correctly account for quantum
fluctuations in the vicinity of the QPT.


title: Gamma ray and Neutrino fluxes from a cosmological dark matter simulation

abstract:
  In this paper, we estimate the gamma-ray and neutrino fluxes coming from dark
matter annihilation in a Milky Way framework provided by a recent N-BODY
HORIZON simulation. We first study the characteristics of the simulation and
highlight the mass distribution within the galactic halo. The general dark
matter density has a typical $r^{-3}$ power law for large radii, but the inner
behaviour is poorly constrained below the resolution of the simulation ($\sim
200$ pc). We identify clumps and subclumps and analyze their distribution, as
well as their internal structure. Inside the clumps, the power law is rather
universal, $r^{-2.5}$ in the outer part with again strong uncertainties for
smaller radii, especially for light clumps. We show a full-sky map of the
astrophysical contribution to the gamma-ray or neutrino fluxes in this N-body
framework. Using quite model independent and general assumptions for the high
energy physics part, we evaluate the possible absolute fluxes and show some
benchmark regions for the experiments GLAST, EGRET, and a km3 size extension of
ANTARES like the KM3NeT project. While individual clumps seem to be beyond
detection reach, the galactic center region is promising and GLAST could be
sensitive to the geometry and the structure of its dark matter distribution.
The detection by a km3 version of ANTARES is, however, more challenging due to
a higher energy threshold. We also point out that the lack of resolution leaves
the inner structure of subhalos poorly constrained. Using the same clump
spectrum and mass fraction, a clump luminosity boost of order ten can be
achieved with a steeper profile in the inner part of the sub-halos.


title: Was the Universe neutral beyond redshift six?

abstract:
  We provide measurements of the neutral hydrogen fraction xHI at z~6, by
comparing semi-analytical models of the Lyalpha forest with observations of
high-z quasars and Gamma Ray Bursts absorption spectra. We analyze the
transmitted flux in a sample of 17 QSOs spectra at 5.74<zem<6.42 studying
separately the narrow transmission windows (peaks) and the wide dark portions
(gaps) in the observed absorption spectra. By comparing the statistics of these
spectral features with our models, we conclude that xHI evolves smoothly from
10^{-4.4} at z=5.3 to 10^{-4.2} at z=5.6, with a robust upper limit xHI<0.36 at
z=6.3. We show the results of the first-ever detected transverse proximity
effect in the HI Lyalpha forest, produced by the HII region of the faint quasar
RD J1148+5253 at z=5.70 intervening along the LOS of SDSS J1148+5251 at z=6.42.
Moreover, we propose a novel method to study cosmic reionization using
absorption line spectra of high-redshift GRBs afterglows. We show that the time
evolution and the statistics of gaps in the observed spectra represent
exquisite tools to discriminate among different reionization models. By
applying our methods to GRB 050904 detected at z=6.29, we show that the
observation of this burst provides strong indications of a highly ionized
intergalactic medium at z~6, with an estimated mean neutral hydrogen fraction
xHI=6.4\pm 0.3\times 10^{-5} along that line of sight.


title: An X-ray view of absorbed INTEGRAL AGN

abstract:
  Aims. We present a 0.2--200 keV broad-band study of absorbed AGN observed
with INTEGRAL, XMM-Newton, Chandra and ASCA to investigate the continuum shape
and the absorbing/reflecting medium properties. Methods. The sources are
selected in the INTEGRAL AGN sample to have a 20--100 keV flux below
8$\times10^{-11}$ $\flux$ (5 mCrab), and are characterized by a 2--10 keV flux
in the range (0.8--10)$\times10^{-11}$ $\flux$. The good statistics allow us a
detailed study of the intrinsic and reflected continuum components. In
particular, the analysis performed on the combined broad-band spectra allow us
to investigate the presence of Compton reflection features and high energy
cut-off in these objects. Results. The column density of the absorbing gas
establishes the Compton thin nature for three sources in which a measure of the
absorption was still missing. The Compton thin nature of all the sources in
this small sample is also confirmed by the diagnostic ratios F$x/F[OIII]. The
Compton reflection components we measure, reflection continuum and iron line,
are not immediately compatible with a scenario in which the absorbing and
reflecting media are one and the same, i.e. the obscuring torus. A possible
solution is that the absorption is more effective than reflection, e.g. under
the hypothesis that the absorbing/reflecting medium is not uniform, like a
clumpy torus, or that the source is observed through a torus with a very
shallow opening angle. The high energy cut-off (a lower limit in two cases) is
found in all sources of our sample and the range of values is in good agreement
with that found in type 1 Seyfert galaxies. At lower energies there is clear
evidence of a soft component (reproduced with a thermal and/or scattering
model), in six objects.


title: On the Reeh-Schlieder Property in Curved Spacetime

abstract:
  We attempt to prove the existence of Reeh-Schlieder states on curved
spacetimes in the framework of locally covariant quantum field theory using the
idea of spacetime deformation and assuming the existence of a Reeh-Schlieder
state on a diffeomorphic (but not isometric) spacetime. We find that physically
interesting states with a weak form of the Reeh-Schlieder property always exist
and indicate their usefulness. Algebraic states satisfying the full
Reeh-Schlieder property also exist, but are not guaranteed to be of physical
interest.


title: Gamma-reduction for smooth orbifolds

abstract:
  The aim of this short note is to show how to construct a rationnal Remmert
reduction for the universal cover of a smooth K\"ahler orbifold. Doins this, we
are led to introduce some singular K\"ahler metrics adapted to the orbifold
structure.


title:
Stagnation zones for $\mathcal{A}$-harmonic functions on canonical
  domains

abstract:
  We study stagnation zones of $\mathcal{A}$-harmonic functions on canonical
domains in the Euclidean $n$-dimensional space. Phragmen-Lindel\"of type
theorems are proved.


title:
XMM-Newton observations of the Small Magellanic Cloud: X-ray outburst of
  the 6.85 s pulsar XTE J0103-728

abstract:
  A bright X-ray transient was seen during an XMM-Newton observation in the
direction of the Small Magellanic Cloud (SMC) in October 2006. The EPIC data
allow us to accurately locate the source and to investigate its temporal and
spectral behaviour. X-ray spectra covering 0.2-10 keV and pulse profiles in
different energy bands were extracted from the EPIC data. The detection of 6.85
s pulsations in the EPIC-PN data unambiguously identifies the transient with
XTE J0103-728, discovered as 6.85 s pulsar by RXTE. The X-ray light curve
during the XMM-Newton observation shows flaring activity of the source with
intensity changes by a factor of two within 10 minutes. Modelling of
pulse-phase averaged spectra with a simple absorbed power-law indicates
systematic residuals which can be accounted for by a second emission component.
For models implying blackbody emission, thermal plasma emission or emission
from the accretion disk (disk-blackbody), the latter yields physically sensible
parameters. The photon index of the power-law of ~0.4 indicates a relatively
hard spectrum. The 0.2-10 keV luminosity was 2x10^{37} with a contribution of
~3% from the disk-blackbody component. A likely origin for the excess emission
is reprocessing of hard X-rays from the neutron star by optically thick
material near the inner edge of an accretion disk. From a timing analysis we
determine the pulse period to 6.85401(1) s indicating an average spin-down of
~0.0017 s per year since the discovery of XTE J0103-728 in May 2003. The X-ray
properties and the identification with a Be star confirm XTE J0103-728 as
Be/X-ray binary transient in the SMC.


title:
Intrinsic metrological resolution as a distance measure and nonclassical
  light

abstract:
  We elaborate on a Hilbert-Schmidt distance measure assessing the intrinsic
metrological accuracy in the detection of signals imprinted on quantum probe
states by signal-dependent transformations. For small signals this leads to a
probe-transformation measure $\Lambda$ fully symmetric on the probe $\rho$ and
the generator $G$ of the transformation $\Lambda (\rho, G) = \Lambda (G,
\rho)$. Although $\Lambda$ can be regarded as a generalization of variance we
show that no uncertainty relation holds for the product of measures
corresponding to complementary generators. We show that all states with
resolution larger than coherent states are nonclassical. We apply this
formalism to feasible probes and transformations.


title:
Collision Cross Section of the J = 2 <- 1 Rotational Transition of
  CF3CCH due to Higher Order Interactions

abstract:
  The collision cross section of the rotational transition J = 2 <- 1 of
3,3,3-trifluoropropyne, CF3CCH, caused by rare gas perturbers has been
determined by investigating transient emission signals of molecular gas
samples. From analysis of the pressure dependence of the width of the
rotational line J = 2<-1 pressure broadening parameters have been derived for
the pure gas and for mixtures with the rare gases He, Ne, Ar, Kr and Xe. The
pressure shift parameter for the pure gas sigmas/p = 29.03(12) kHz/Pa also has
been obtained. Calculations based on the Anderson-Tsao-Curnutte theory using
induction and dispersion interactions for the description of collisions of
CF3CCH with He, Ne, Ar, Kr and Xe, respectively, are in qualitative agreement
with the experimental results.


title: Critical Exponents from Field Theory: New Evaluation

abstract:
  We present new evaluation of the critical exponents of O(n)- symmetric \phi^4
theory from the field theoretical renormalization group, based on the new
algorithm for summing divergent series. The central values practically coincide
with those by Le Guillou and Zinn-Justin (1980) but their uncertainty is
essentially smaller.


title:
Crystal and magnetic structure of (La0.70Ca0.30)(CryMn1-y)O3: a neutron
  powder diffraction study

abstract:
  The crystal and magnetic structure of (La0.70Ca0.30)(CryMn1-y)O3 for y =
0.70, 0.50 and 0.15 has been investigated using neutron powder diffraction. The
three samples crystallize in the Pnma space group at both 290 K and 5 K and
exhibit different magnetic structures at low temperature. In
(La0.70Ca0.30)(Cr0.70Mn0.30)O3, antiferromagnetic order with a propagation
vector k = 0 sets in. The magnetic structure is Gx, i.e. of the G-type with
spins parallel to the a-axis. On the basis of our Rietveld refinement and the
available magnetisation data, we speculate that only Cr3+ spins order, whereas
Mn4+ act as a random magnetic impurity. In (La0.70Ca0.30)(Cr0.50Mn0.50)O3 the
spin order is still of type Gx, although the net magnetic moment is smaller. No
evidence for magnetic order of the Mn ions is observed. Finally, in
(La0.70Ca0.30)(Cr0.15Mn0.85)O3 a ferromagnetic ordering of the Mn spins takes
place, whereas the Cr3+ ions act as random magnetic impurities with randomly
oriented spins.


title: Communities in Neuronal Complex Networks Revealed by Activation Patterns

abstract:
  Recently, it has been shown that the communities in neuronal networks of the
integrate-and-fire type can be identified by considering patterns containing
the beginning times for each cell to receive the first non-zero activation. The
received activity was integrated in order to facilitate the spiking of each
neuron and to constrain the activation inside the communities, but no time
decay of such activation was considered. The present article shows that, by
taking into account exponential decays of the stored activation, it is possible
to identify the communities also in terms of the patterns of activation along
the initial steps of the transient dynamics. The potential of this method is
illustrated with respect to complex neuronal networks involving four
communities, each of a different type (Erd\H{o}s-R\'eny, Barab\'asi-Albert,
Watts-Strogatz as well as a simple geographical model). Though the
consideration of activation decay has been found to enhance the communities
separation, too intense decays tend to yield less discrimination.


title:
XMM-Newton observations of 4 luminous radio-quiet AGN, and the soft
  X-ray excess problem

abstract:
  The nature and origin of the soft X-ray excess in radio quiet AGN is still an
open issue. The interpretation in terms of thermal disc emission has been
challanged by the discovery of the constancy of the effective temperature
despite the wide range of Black Hole masses of the observed sources.
Alternative models are reflection from ionized matter and absorption in a
relativistically smeared wind. We analyzed XMM-Newton observations of four
luminous radio quiet AGN with the aim of characterising their main properties
and in particular the soft excess. Different spectral models for the soft
excess were tried: thermal disc emission, Comptonization, ionized reflection,
relativistically smeared winds. Comptonization of thermal emission and the
smeared winds provide the best fits, but the other models also provide
acceptable fits. All models, however, return parameters very similar from
source to source, despite the large differences in luminosities, Black Hole
masses and Eddington ratios. Moreover, the smeared wind model require very
large smearing velocities. The UV to X-ray fluxes ratios are very different,
but do not correlate with any other parameter. No fully satisfactory
explanation for the soft X-ray excess is found. Better data, like e.g.
observations in a broader energy band, are needed to make further progresses.


title:
Possibility of the 2D Anderson Transition and Generalized Lyapunov
  Exponents

abstract:
  The possible existence of the Anderson transition in 2D systems without
interaction and spin-orbit effects (such as the usual Anderson model) becomes
recently a subject of controversy in the literature. Comparative analysis of
approaches based on generalized Lyapunov exponents is given, in order to
resolve controversy.


title:
Power dependent switching of nonlinear trapping by local photonic
  potentials

abstract:
  We study experimentally and numerically the nonlinear scattering of wave
packets by local multi-site guiding centers embedded in a continuous dielectric
medium, as a function of the input power and angle of incidence. The extent of
trapping into the linear modes of different sites is manipulated as a function
of both the input power and incidence angle, demonstrating power-controlled
switching of nonlinear trapping by local photonic potentials.


title: A PEP model of the electron

abstract:
  One of the more profound mysteries of physics is how nature ties together EM
fields to form an electron. A way to do this is examined in this study. A bare
magnetic dipole containing a flux quantum spins stably, and produces an inverse
square E= -vxB electric field similar to what one finds from charge. Gauss' law
finds charge in this model, though there be none. For stability, a current loop
about the waist of the magnetic dipole is needed and we must go beyond the
classical Maxwell's equations to find it. A spinning E field is equivalent to
an electric displacement current. The sideways motion of the spinning E (of
constant magnitude) creates a little-recognized transverse electric
displacement current about the waist. This differs from Maxwell's electric
displacement current, in which E increases in magnitude. The sideways motion of
E supports the dipolar B field, B=vxE/c^2. Beyond the very core of the magnetic
dipole, each of these two velocities is essentially c and vxE/c^2 =
vx(-vxB)/c^2 = B, the spinning E field wholly sourcing the dipolar B field. The
anisotropy of the vxB field is cured by precession about an inclined axis.
Choosing a Bohr magneton for the magnetic dipole and assuming it spins at the
Compton frequency, Gauss' law finds Q = e. The vxB field, normally thought to
be solenoidal, becomes instead a conservative field in this model. Charge is
recognized as merely a mathematical construct, not fundamental but nevertheless
useful. With charge deleted, and with addition of the transverse electric
displacement current, Maxwell's equations can be written in terms of the E and
B fields alone.


title:
Quantum phase transitions in an effective Hamiltonian: fast and slow
  systems

abstract:
  An effective Hamiltonian describing interaction between generic "fast" and a
"slow" systems is obtained in the strong interaction limit. The result is
applied for studying the effect of quantum phase transition as a bifurcation of
the ground state of the "slow subsystem" in the thermodynamic limit. Examples
as atom-field and atom-atom interactions are analyzed in detail.


title: Cosmological implications of an evolutionary quantum gravity

abstract:
  The cosmological implications of an evolutionary quantum gravity are analyzed
in the context of a generic inhomogeneous model. The Schr\"{o}dinger problem is
formulated and solved in the presence of a scalar field, an ultrarelativistic
matter and a perfect gas regarded as the dust-clock. Considering the actual
phenomenology, it is shown how the evolutionary approach overlaps the
Wheeler-DeWitt one.


title:
Polaronic signatures in the optical properties of
  Nd$_{2-x}$Ce$_x$CuO$_4$

abstract:
  We investigate the temperature and doping dependence of the optical
conductivity $\sigma(\omega)$ of Nd$_{2-x}$Ce$_x$CuO$_4$ in terms of
magnetic/lattice polaron formation. We employ dynamical mean-field theory in
the context of the Holstein-t-J model where an exact analytical solution is
available in the limit of infinite connectivity. We show that the pseudogap
features in the optical conductivity of this compound can be associated to the
formation of lattice polarons assisted by the magnetic interaction.


title: Killing Vector Fields of Standard Static Space-times

abstract:
  We consider Killing vector fields on standard static space-times and obtain
equations for a vector field on a standard static space-time to be Killing. We
also provide a characterization of Killing vector fields on standard static
space-times with compact Riemannian parts.


title: A Modular Curve of Level 9 and the Class Number One Problem

abstract:
  In this note we give an explicit parametrization of the modular curve
associated to the normalizer of a non-split Cartan subgroup of level 9. We
determine all integral points of this modular curve. As an application, we give
an alternative solution to the class number one problem.


title:
From Heisenberg to Einstein? Recollections and afterthoughts on the
  birth of string theory

abstract:
  A few recollections and afterthoughts on the development of the string
picture of fundamental interactions out of the S-matrix program.


title:
Hydrodynamical adaptive mesh refinement simulations of turbulent flows -
  I. Substructure in a wind

abstract:
  The problem of the resolution of turbulent flows in adaptive mesh refinement
(AMR) simulations is investigated by means of 3D hydrodynamical simulations in
an idealised setup, representing a moving subcluster during a merger event. AMR
simulations performed with the usual refinement criteria based on local
gradients of selected variables do not properly resolve the production of
turbulence downstream of the cluster. Therefore we apply novel AMR criteria
which are optimised to follow the evolution of a turbulent flow. We demonstrate
that these criteria provide a better resolution of the flow past the
subcluster, allowing us to follow the onset of the shear instability, the
evolution of the turbulent wake and the subsequent back-reaction on the
subcluster core morphology. We discuss some implications for the modelling of
cluster cold fronts.


title: SUGRA chaotic inflation and moduli stabilisation

abstract:
  Chaotic inflation predicts a large gravitational wave signal which can be
tested by the upcoming Planck satellite. We discuss a SUGRA implementation of
chaotic inflation in the presence of moduli fields, and find that inflation
does not work with a generic KKLT moduli stabilisation potential. A viable
model can be constructed with a fine-tuned moduli sector, but only for a very
specific choice of Kahler potential. Our analysis also shows that inflation
models satisfying \partial_{i} W_{\rm inf}=0 for all inflation sector fields
\phi_i can be combined successfully with a fine-tuned moduli sector.


title:
Seuils d'instabilit\'e d'un instrument de musique \`a anche simple :
  approche modale

abstract:
  Many musical instruments, as for example woodwind instruments, flute or
violins, are self-sustained oscillating systems, i.e. musician enacts as a
continuous energy source to drive an oscillation in the passive resonator, the
body of the instrument, by means of a nonlinear coupling. For single reed
instruments like clarinet, there exists a minimal value of mouth pressure
beyond which sound can appear. This paper deals with the analysis of this
oscillation threshold, calculated using a modal decomposition of the resonator,
in order to have a better comprehension of how reed characteristics, such as
its strength and its damping, may influence the attack transient of notes.


title: Asymptotic behavior for dissipative Korteweg-de Vrie equations

abstract:
  We study the large time behavior of solutions to the dissipative Korteweg-de
Vrie equations $u_t+u_{xxx}+|D|^{\alpha}u+uu_x=0$ with $0<\alpha<2$. We find
$v$ such that $u-v$ decays like $t^{-r(\alpha)}$ as $t\to\infty$ in various
Sobolev norm.


title: On Cobweb Admissible Sequences - The Production Theorem

abstract:
  In this note further clue decisive observations on cobweb admissible
sequences are shared with the audience. In particular an announced proof of the
Theorem 1 (by Dziemia\'nczuk) from [1] announced in India -Kolkata- December
2007 is delivered here. Namely here and there we claim that any cobweb
admissible sequence F is at the point product of primary cobweb admissible
sequences taking values one and/or certain power of an appropriate primary
number p.
  Here also an algorithm to produce the family of all cobweb-admissible
sequences i.e. the Problem 1 from [1] i.e. one of several problems posed in
source papers [2,3] is solved using the idea and methods implicitly present
already in [4]


title:
Staggered magnetization and entanglement enhancement by magnetic
  impurities in $S=1/2$ spin chain

abstract:
  We study the effects of a magnetic impurity on the behavior of a $S=1/2$ spin
chain. At T=0, both with and without an applied uniform magnetic field, an
oscillating magnetization appears, whose decay with the distance from the
impurity is ruled by a power law. As a consequence, pairwise entanglement is
either enhanced or quenched, depending on the distance of the spin pair with
respect to the impurity and on the values of the magnetic field and the
intensity of the impurity itself. This leads us to suggest that acting on such
control parameters, an adiabatic manipulation of the entanglement distribution
can be performed. The robustness of our results against temperature is checked,
and suggestions about possible experimental applications are put forward.


title: Energy bursts in fiber bundle models of composite materials

abstract:
  As a model of composite materials, a bundle of many fibers with
stochastically distributed breaking thresholds for the individual fibers is
considered. The bundle is loaded until complete failure to capture the failure
scenario of composite materials under external load. The fibers are assumed to
share the load equally, and to obey Hookean elasticity right up to the breaking
point. We determine the distribution of bursts in which an amount of energy $E$
is released. The energy distribution follows asymptotically a universal power
law $E^{-5/2}$, for any statistical distribution of fiber strengths. A similar
power law dependence is found in some experimental acoustic emission studies of
loaded composite materials.


title:
Phenomenological analysis of quantum collapse as source of the seeds of
  cosmic structure

abstract:
  The standard inflationary version of the origin of the cosmic structure as
the result of the quantum fluctuations during the early universe is less than
fully satisfactory as has been argued in [A. Perez, H. Sahlmann, and D.
Sudarsky, Class. Quantum Grav., 23, 2317, (2006)]. A proposal is made there of
a way to address the shortcomings by invoking a process similar to the collapse
of the quantum mechanical wave function of the various modes of the inflaton
field. This in turn was inspired on the ideas of R. Penrose about the role that
quantum gravity might play in bringing about such breakdown of the standard
unitary evolution of quantum mechanics. In this paper we study in some detail
the two schemes of collapse considered in the original work together with an
alternative scheme, which can be considered as "more natural" than the former
two. The new scheme, assumes that the collapse follows the correlations
indicated in the Wigner functional of the initial state. We end with
considerations regarding the degree to which the various schemes can be
expected to produce a spectrum that resembles the observed one.


title:
Hubble Space Telescope STIS Spectroscopy of Long Period Dwarf Novae in
  Quiescence

abstract:
  We present the results of a synthetic spectral analysis of HST STIS spectra
of five long period dwarf novae obtained during their quiescence to determine
the properties of their white dwarfs which are little known for systems above
the CV period gap. The five systems, TU Men, BD Pav, SS Aur, TT Crt, and V442
Cen were observed as part of an HST Snapshot project. The spectra are described
and fitted with combinations of white dwarf photospheres and accretion disks.
We provide evidence that the white dwarfs in all five systems are at least
partially exposed. We discuss the evolutionary implications of our model
fitting results and compare these dwarf novae to previously analyzed FUV
spectra of other dwarf novae above the period gap. The dispersion in CV WD
temperatures above the period gap is substantially greater than one finds below
the period gap where there is a surprisingly narrow dispersion in temperatures
around 15,000K. There appears to be a larger spread of surface temperatures in
dwarf novae above the period than is seen below the gap.


title: Hyperbolicity of arborescent tangles and arborescent links

abstract:
  In this paper, we study the hyperbolicity of arborescent tangles and
arborescent links. We will explicitly determine all essential surfaces in
arborescent tangle complements with non-negative Euler characteristic, and show
that given an arborescent tangle T, the complement X(T) is non-hyperbolic if
and only if T is a rational tangle, T=Q_m * T' for some m greater than or equal
to 1, or T contains Qn for some n greater than or equal to 2. We use these
results to prove a theorem of Bonahon and Seibenmann which says that a large
arborescent link L is non-hyperbolic if and only if it contains Q2.


title: Local Persistence in the Directed Percolation Universality Class

abstract:
  We revisit the problem of local persistence in directed percolation,
reporting improved estimates of the persistence exponent in 1+1 dimensions,
discovering strong corrections to scaling in higher dimensions, and
investigating the mean field limit. Moreover, we introduce a graded persistence
probability that a site does not flip more than n times and demonstrate how
local persistence can be studied in seed simulations. Finally, the problem of
spatial (as opposed to temporal) persistence is investigated.


title:
A Class of Errorless Codes for Over-loaded Synchronous Wireless and
  Optical CDMA Systems

abstract:
  In this paper we introduce a new class of codes for over-loaded synchronous
wireless and optical CDMA systems which increases the number of users for fixed
number of chips without introducing any errors. Equivalently, the chip rate can
be reduced for a given number of users, which implies bandwidth reduction for
downlink wireless systems. An upper bound for the maximum number of users for a
given number of chips is derived. Also, lower and upper bounds for the sum
channel capacity of a binary over-loaded CDMA are derived that can predict the
existence of such over-loaded codes. We also propose a simplified maximum
likelihood method for decoding these types of over-loaded codes. Although a
high percentage of the over-loading factor degrades the system performance in
noisy channels, simulation results show that this degradation is not
significant. More importantly, for moderate values of Eb/N0 (in the range of
6-10 dB) or higher, the proposed codes perform much better than the binary
Welch bound equality sequences.


title:
Axial charges of N(1535) and N(1650) in lattice QCD with two flavors of
  dynamical quarks

abstract:
  We show the first lattice QCD results on the axial charge $g_A^{N^*N^*}$ of
$N^*(1535)$ and $N^*(1650)$. The measurements are performed with two flavors of
dynamical quarks employing the renormalization-group improved gauge action at
$\beta$=1.95 and the mean-field improved clover quark action with the hopping
parameters, $\kappa$=0.1375, 0.1390 and 0.1400. In order to properly separate
signals of $N^*(1535)$ and $N^*(1650)$, we construct 2$\times$2 correlation
matrices and diagonalize them. Wraparound contributions in the correlator,
which can be another source of signal contaminations, are eliminated by
imposing the Dirichlet boundary condition in the temporal direction. We find
that the axial charge of $N^*(1535)$ takes small values as $g_A^{N^*N^*}\sim
{\mathcal O}(0.1)$, whereas that of $N^*(1650)$ is about 0.5, which is found
independent of quark masses and consistent with the predictions by the naive
nonrelativistic quark model.


title:
Gradient Estimate and Harnack Inequality on Non-Compact Riemannian
  Manifolds

abstract:
  A new type of gradient estimate is established for diffusion semigroups on
non-compact complete Riemannian manifolds. As applications, a global Harnack
inequality with power and a heat kernel estimate are derived for diffusion
semigroups on arbitrary complete Riemannian manifolds.


title: Temporal Correlations of Local Network Losses

abstract:
  We introduce a continuum model describing data losses in a single node of a
packet-switched network (like the Internet) which preserves the discrete nature
of the data loss process. {\em By construction}, the model has critical
behavior with a sharp transition from exponentially small to finite losses with
increasing data arrival rate. We show that such a model exhibits strong
fluctuations in the loss rate at the critical point and non-Markovian power-law
correlations in time, in spite of the Markovian character of the data arrival
process. The continuum model allows for rather general incoming data packet
distributions and can be naturally generalized to consider the buffer server
idleness statistics.


title: Quantum trajectories, feedback and squeezing

abstract:
  Quantum trajectory theory is the best mathematical set up to model continual
observations of a quantum system and feedback based on the observed output.
Inside this framework, we study how to enhance the squeezing of the
fluorescence light emitted by a two-level atom, stimulated by a coherent
monochromatic laser. In the presence of a Wiseman-Milburn feedback scheme,
based on the homodyne detection of a fraction of the emitted light, we analyze
the squeezing dependence on the various control parameters.


title:
Polarized Structure Function $\sigma_{LT'}$ for $p({\vec
  e},e'K^+)\Lambda$ in the Nucleon Resonance Region

abstract:
  The first measurements of the polarized structure function $\sigma_{LT'}$ for
the reaction $p(\vec e,e'K^+)\Lambda$ in the nucleon resonance region are
reported. Measurements are included from threshold up to $W$=2.05 GeV for
central values of $Q^2$ of 0.65 and 1.00 GeV$^2$, and nearly the entire kaon
center-of-mass angular range. $\sigma_{LT'}$ is the imaginary part of the
longitudinal-transverse response and is expected to be sensitive to
interferences between competing intermediate s-channel resonances, as well as
resonant and non-resonant processes. The results for $\sigma_{LT'}$ are
comparable in magnitude to previously reported results from CLAS for
$\sigma_{LT}$, the real part of the same response. An intriguing sign change in
$\sigma_{LT'}$ is observed in the high $Q^2$ data at $W\approx 1.9$ GeV.
Comparisons to several existing model predictions are shown.


title: Massive Stars as Cosmic Engines through the Ages

abstract:
  Some useful developments in the model physics are briefly presented, followed
by model results on chemical enrichments and WR stars. We discuss the expected
rotation velocities of WR stars. We emphasize that the (C+O)/He ratio is a
better chemical indicator of evolution for WC stars than the C/He ratios. With
or without rotation, at a given luminosity the (C+O)/He ratios should be higher
in regions of lower metallicity Z. Also, for a given (C+O)/He ratio the WC
stars in lower Z regions have higher luminosities. The WO stars, which are
likely the progenitors of supernovae SNIc and of some GRBs, should
preferentially be found in regions of low Z and be the descendants of very high
initial masses. Finally, we emphasize the physical reasons why massive rotating
low Z stars may also experience heavy mass loss


title: Frames of p-adic wavelets and orbits of the affine group

abstract:
  The general construction of frames of p-adic wavelets is described. We
consider the orbit of a mean zero generic locally constant function with
compact support (mean zero test function) with respect to the action of the
p-adic affine group and show that this orbit is a uniform tight frame. We
discuss relation of this result to the multiresolution wavelet analysis.


title: Breaking One-Round Key-Agreement Protocols in the Random Oracle Model

abstract:
  In this paper we study one-round key-agreement protocols analogous to
Merkle's puzzles in the random oracle model. The players Alice and Bob are
allowed to query a random permutation oracle $n$ times and upon their queries
and communication, they both output the same key with high probability. We
prove that Eve can always break such a protocol by querying the oracle $O(n^2)$
times. The long-time unproven optimality of the quadratic bound in the fully
general, multi-round scenario has been shown recently by Barak and
Mahmoody-Ghidary. The results in this paper have been found independently of
their work.


title:
Differential equations with discrete state-dependent delay: uniqueness
  and well-posedness in the space of continuous functions

abstract:
  Partial differential equations with discrete (concentrated) state-dependent
delays in the space of continuous functions are investigated. In general, the
corresponding initial value problem is not well posed, so we find an additional
assumption on the state-dependent delay function to guarantee the well
posedness. For the constructed dynamical system we study the long-time
asymptotic behavior and prove the existence of a compact global attractor.


title:
Methods to integrate a language model with semantic information for a
  word prediction component

abstract:
  Most current word prediction systems make use of n-gram language models (LM)
to estimate the probability of the following word in a phrase. In the past
years there have been many attempts to enrich such language models with further
syntactic or semantic information. We want to explore the predictive powers of
Latent Semantic Analysis (LSA), a method that has been shown to provide
reliable information on long-distance semantic dependencies between words in a
context. We present and evaluate here several methods that integrate LSA-based
information with a standard language model: a semantic cache, partial
reranking, and different forms of interpolation. We found that all methods show
significant improvements, compared to the 4-gram baseline, and most of them to
a simple cache model as well.


title:
Necessary and Sufficient Lyapunov-Like Conditions for Robust Nonlinear
  Stabilization

abstract:
  In this work, we propose a methodology for the expression of necessary and
sufficient Lyapunov-like conditions for the existence of stabilizing feedback
laws. The methodology is an extension of the well-known Control Lyapunov
Function (CLF) method and can be applied to very general nonlinear time-varying
systems with disturbance and control inputs, including both finite- and
infinite-dimensional systems. The generality of the proposed methodology is
also reflected upon by the fact that partial stability with respect to output
variables is addressed. In addition, it is shown that the generalized CLF
method can lead to a novel tool for the explicit design of robust nonlinear
controllers for a class of time-delay nonlinear systems with a triangular
structure.


title: Vacancy diffusion in the triangular lattice dimer model

abstract:
  We study vacancy diffusion on the classical triangular lattice dimer model,
sub ject to the kinetic constraint that dimers can only translate, but not
rotate. A single vacancy, i.e. a monomer, in an otherwise fully packed lattice,
is always localized in a tree-like structure. The distribution of tree sizes is
asymptotically exponential and has an average of 8.16 \pm 0.01 sites. A
connected pair of monomers has a finite probability of being delocalized. When
delocalized, the diffusion of monomers is anomalous:


title:
Time-Resolved X-ray Microscopy of Spin-Torque-Induced Magnetic Vortex
  Gyration

abstract:
  Time-resolved X-ray microscopy is used to image the influence of alternating
high-density currents on the magnetization dynamics of ferromagnetic vortices.
Spin-torque induced vortex gyration is observed in micrometer-sized permalloy
squares. The phases of the gyration in structures with different chirality are
compared to an analytical model and micromagnetic simulations, considering both
alternating spinpolarized currents and the current's Oersted field. In our case
the driving force due to spin-transfer torque is about 70% of the total
excitation while the remainder originates from the current's Oersted field.
This finding has implications to magnetic storage devices using spin-torque
driven magnetization switching and domain-wall motion.


title: Chaotic quantization and the mass spectrum of fermions

abstract:
  In order to understand the parameters of the standard model of electroweak
and strong interactions, one needs to embed the standard model into some larger
theory that accounts for the observed values. This means some additional sector
is needed that fixes and stabilizes the values of the fundamental constants of
nature. We describe how such a sector can be constructed using the so-called
chaotic quantization method applied to a system of coupled map lattices. We
restrict ourselves in this short note on verifying how our model correctly
yields the numerical values of Yukawa and gravitational coupling constants of a
collection of heavy and light fermions using a simple principle, the local
minimization of vacuum energy.


title:
Extremal covariant positive operator valued measures: the case of a
  compact symmetry group

abstract:
  Given a unitary representation U of a compact group G and a transitive
G-space $\Omega$, we characterize the extremal elements of the convex set of
all U-covariant positive operator valued measures.


title: Particle-scale origins of shear strength in granular media

abstract:
  The shear strength of cohesionless granular materials is generally attributed
to the compactness or anisotropy of their microstructure. An open issue is how
such compact or anisotropic microstructures, and thus the shear strength,
depend on the particle properties. We first recall the role of fabric and force
anisotropies with respect to the critical-state shear stress. Then, a model of
accessible geometrical states in terms of particle connectivity and contact
anisotropy is presented. This model incorporates in a simple way the fact that,
due to steric exclusions, the highest levels of connectivity and anisotropy
cannot be reached simultaneously, a property that affects seriously the shear
strength. We also analyze the force anisotropy in the light of the specific
role of weak forces in sustaining strong force chains and thus the main
mechanism that underlies anisotropic force patterns. Finally, we briefly
discuss the effect of interparticle friction, particle shape, size
polydispersity and adhesion.


title: Ramsey-like cardinals

abstract:
  One of the numerous characterizations of a Ramsey cardinal kappa involves the
existence of certain types of elementary embeddings for transitive sets of size
\kappa satisfying a large fragment of ZFC. We introduce new large cardinal
axioms generalizing the Ramsey elementary embeddings characterization and show
that they form a natural hierarchy between weakly compact cardinals and
measurable cardinals. These new axioms serve to further our knowledge about the
elementary embedding properties of smaller large cardinals, in particular those
still consistent with V=L.


title: Links between magnetic fields and plasma flows in a coronal hole

abstract:
  We compare the small-scale features visible in the Ne viii Doppler-shift map
of an equatorial coronal hole (CH) as observed by SUMER with the small-scale
structures of the magnetic field as constructed from a simultaneous
photospheric magnetogram by a potential magnetic-field extrapolation. The
combined data set is analysed with respect to the small-scale flows of coronal
matter, which means that the Ne viii Doppler-shift used as tracer of the plasma
flow is investigated in close connection with the ambient magnetic field. Some
small closed-field regions in this largely open CH are also found in the
coronal volume considered. The Doppler-shift patterns are found to be clearly
linked with the field topology.


title: The Bernoulli sieve revisited

abstract:
  We consider an occupancy scheme in which "balls" are identified with $n$
points sampled from the standard exponential distribution, while the role of
"boxes" is played by the spacings induced by an independent random walk with
positive and nonlattice steps. We discuss the asymptotic behavior of five
quantities: the index $K_n^*$ of the last occupied box, the number $K_n$ of
occupied boxes, the number $K_{n,0}$ of empty boxes whose index is at most
$K_n^*$, the index $W_n$ of the first empty box and the number of balls $Z_n$
in the last occupied box. It is shown that the limiting distribution of
properly scaled and centered $K_n^*$ coincides with that of the number of
renewals not exceeding $\log n$. A similar result is shown for $K_n$ and $W_n$
under a side condition that prevents occurrence of very small boxes. The
condition also ensures that $K_{n,0}$ converges in distribution. Limiting
results for $Z_n$ are established under an assumption of regular variation.


title: Stochastic extrema as stationary phases of characteristic functions

abstract:
  The paper is dealing with semi-classical asymptotics of a characteristic
function for a stochastic process. The main technical tool is provided by the
stationary phase method. The extremal range for a stochastic process is defined
by limit values of the complex logarithm of the characteristic function. The
paper also outlines a numerical method for calculating stochastic extrema.


title: Berry phase in graphene: a semiclassical perspective

abstract:
  We derive a semiclassical expression for the Green's function in graphene, in
which the presence of a semiclassical phase is made apparent. The relationship
between this semiclassical phase and the adiabatic Berry phase, usually
referred to in this context, is discussed. These phases coincide for the
perfectly linear Dirac dispersion relation. They differ however when a gap is
opened at the Dirac point. We furthermore present several applications of our
semiclassical formalism. In particular we provide, for various configurations,
a semiclassical derivation of the electron's Landau levels, illustrating the
role of the semiclassical ``Berry-like'' phase


title: A Unified Model of Phantom Energy and Dark Matter

abstract:
  To explain the acceleration of the cosmological expansion researchers have
considered an unusual form of mass-energy generically called dark energy. Dark
energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$.
This form of mass-energy leads to accelerated expansion. An extreme form of
dark energy, called phantom energy, has been proposed which has $w=p/\rho <-1$.
This possibility is favored by the observational data. The simplest model for
phantom energy involves the introduction of a scalar field with a negative
kinetic energy term. Here we show that theories based on graded Lie algebras
naturally have such a negative kinetic energy and thus give a model for phantom
energy in a less ad hoc manner. We find that the model also contains ordinary
scalar fields and anti-commuting (Grassmann) vector fields which act as a form
of two component dark matter. Thus from a gauge theory based on a graded
algebra we naturally obtained both phantom energy and dark matter.


title:
Hydrodynamical adaptive mesh refinement simulations of turbulent flows -
  II. Cosmological simulations of galaxy clusters

abstract:
  The development of turbulent gas flows in the intra-cluster medium and in the
core of a galaxy cluster is studied by means of adaptive mesh refinement (AMR)
cosmological simulations. A series of six runs was performed, employing
identical simulation parameters but different criteria for triggering the mesh
refinement. In particular, two different AMR strategies were followed, based on
the regional variability of control variables of the flow and on the
overdensity of subclumps, respectively. We show that both approaches, albeit
with different results, are useful to get an improved resolution of the
turbulent flow in the ICM. The vorticity is used as a diagnostic for
turbulence, showing that the turbulent flow is not highly volume-filling but
has a large area-covering factor, in agreement with previous theoretical
expectations. The measured turbulent velocity in the cluster core is larger
than 200 km/s, and the level of turbulent pressure contribution to the cluster
hydrostatic equilibrium is increased by using the improved AMR criteria.


title: Fission Decay Widths for Heavy-Ion Fusion-Fission Reactions

abstract:
  Cross-section and neutron-emission data from heavy-ion fusion-fission
reactions are consistent with a Kramers-modified statistical model which takes
into account the collective motion of the system about the ground state; the
temperature dependence of the location of fission transition points; and the
orientation degree of freedom. We see no evidence to suggest that the nuclear
viscosity departs from the surface-plus-window dissipation model. The strong
increase in the nuclear viscosity above a temperature of ~1 MeV deduced by
others is an artifact generated by an inadequate fission model.


title: Stabilization of nonlinear systems with semi-quadratic cost

abstract:
  The paper addresses the stabilization of nonlinear systems with
semi-quadratic cost: quadratic with respect to controls and nonlinear for state
variables. Paper presents the effective new feedback synthesis procedure. The
novel feedback design procedure is based on the ideas borrowed from nonlinear
optics and the theory of semi-classical asymptotics.


title: Star formation and bar instability in cosmological haloes

abstract:
  This is the third of a series of papers presenting the first attempt to
analyze the growth of the bar instability in a consistent cosmological
scenario. In the previous two articles we explored the role of the cosmology on
stellar disks, and the impact of the gaseous component on a disk embedded in a
cosmological dark matter halo. The aim of this paper is to point out the impact
of the star formation on the bar instability inside disks having different gas
fractions. We perform cosmological simulations of the same disk-to-halo mass
systems as in the previous works where the star formation was not triggered. We
compare the results of the new simulations with the previous ones to
investigate the effect of the star formation by analysing the morphology of the
stellar components, the bar strength, the behaviour of the pattern speed. We
follow the gas and the central mass concentration during the evolution and
their impact on the bar strength. In all our cosmological simulations a stellar
bar, lasting 10 Gyr, is still living at z=0. The central mass concentration of
gas and of the new stars has a mild action on the ellipticity of the bar but is
not able to destroy it; at z=0 the stellar bar strength is enhanced by the star
formation. The bar pattern speed is decreasing with the disk evolution.


title: Yang-Mills theory and Tamagawa numbers

abstract:
  Atiyah and Bott used equivariant Morse theory applied to the Yang-Mills
functional to calculate the Betti numbers of moduli spaces of vector bundles
over a Riemann surface, rederiving inductive formulae obtained from an
arithmetic approach which involved the Tamagawa number of SL_n. This article
surveys this link between Yang-Mills theory and Tamagawa numbers, and explains
how methods used over the last three decades to study the singular cohomology
of moduli spaces of bundles on a smooth complex projective curve can be adapted
to the setting of A^1-homotopy theory to study the motivic cohomology of these
moduli spaces.


title: Delayed pulsar kicks from the emission of sterile neutrinos

abstract:
  The observed velocities of pulsars suggest the possibility that sterile
neutrinos with mass of several keV are emitted from a cooling neutron star. The
same sterile neutrinos could constitute all or part of cosmological dark
matter. The neutrino-driven kicks can exhibit delays depending on the mass and
the mixing angle, which can be compared with the pulsar data. We discuss the
allowed ranges of sterile neutrino parameters, consistent with the latest
cosmological and X-ray bounds, which can explain the pulsar kicks for different
delay times.


title: The inverse problem for invariant Lagrangians on a Lie group

abstract:
  We discuss the problem of the existence of a regular invariant Lagrangian for
a given system of invariant second-order differential equations on a Lie group
$G$, using approaches based on the Helmholtz conditions. Although we deal with
the problem directly on $TG$, our main result relies on a reduction of the
system on $TG$ to a system on the Lie algebra of $G$. We conclude with some
illustrative examples.


title:
Single particle relaxation time versus transport scattering time in a 2D
  graphene layer

abstract:
  We theoretically calculate and compare the single-particle relaxation time
($\tau_s$) defining quantum level broadening and the transport scattering time
($\tau_t$) defining Drude conductivity in 2D graphene layers in the presence of
screened charged impurities scattering and short-range defect scattering. We
find that the ratio $\tau_t/\tau_s$ increases strongly with increasing $k_F
z_i$ and $\kappa$ where $k_F$, $z_i$, and $\kappa$ are respectively the Fermi
wave vector, the separation of the substrate charged impurities from the
graphene layer, and the background lattice dielectric constant. A critical
quantitative comparison of the $\tau_t/\tau_s$ results for graphene with the
corresponding modulation-doped semiconductor structures is provided, showing
significant differences between these two 2D carrier systems.


title:
Automatic Control over the Cosmological Constant through Non-minimal
  Phantom and Quintessence

abstract:
  A mechanism to control the cosmological constant through a scalar field
non-minimally coupled to gravity is proposed. By utilizing non-minimal phantom
or quintessence, the cosmological constant, which may be large originally, can
be automatically driven to a value on the scale of the mass parameter in the
phantom/quintessence potential V(phi). The reduction of a large cosmological
constant involves the weakening of gravity that therefore may be much stronger
initially. There exist the cases where originally gravity is on the TeV scale
so that the hierarchy between gravity and three gauge interactions in the
standard model of particle physics is bridged at the beginning. Although the
cosmological constant can be automatically tuned or largely reduced under this
mechanism, its energy density may still remain on the same order of magnitude
as the original one. Thus, explaining the smallness of the
observation-suggested cosmological constant energy density is still a difficult
mission yet to be completed.


title: Binary recycled pulsars, as a most precise physical laboratory

abstract:
  The following problems are discussed. 1. Pulsars and close binaries. 2.
Hulse-Taylor pulsar. 3. Disrupted pulsar pairs. 4. RP statistics. 5. Enhanced
evaporation: formation of single RP. 6. General relativity effects: NS+NS. 7. A
Double pulsar system. 8. Checking general relativity. 9. Variability of the
gravitational constant. 10. Space Watch.


title:
Axions and "Light Shining Through a Wall": A Detailed Theoretical
  Analysis

abstract:
  We give a detailed study of axion-photon and photon-axion conversion
amplitudes, which enter the analysis of ``light shining through a wall''
experiments. Several different calculational methods are employed and compared,
and in all cases we retain a nonzero axion mass. To leading order, we find that
when the photon frequency $\omega$ is very close to the axion mass $m$, there
is a threshold cusp which significantly enhances the photon to axion conversion
amplitude, by a factor $\omega/\sqrt{\omega^2-m^2}$ relative to the
corresponding axion to photon conversion process. When $m=0$, the enhancement
factor reduces to unity and the results of previous calculations are recovered.
Our calculations include an exact wave matching analysis, which shows how
unitarity is maintained near threshold at $\omega=m$, and a discussion of the
case when the magnetic field extends into the ``wall'' region.


title: Brill-Noether Theory for stable vector bundles

abstract:
  This paper gives an overview of the main results of Brill-Noether Theory for
vector bundles on algebraic curves.


title:
Construction of combinatorial manifolds with the prescribed sets of
  links of vertices

abstract:
  To each oriented closed combinatorial manifold we assign the set (with
repetitions) of isomorphism classes of links of its vertices. The obtained
transformation L is the main object of study of the present paper. We pose a
problem on the inversion of the transformation L. We shall show that this
problem is closely related to N.Steenrod's problem on realization of cycles and
to the Rokhlin-Schwartz-Thom construction of combinatorial Pontryagin classes.
It is easy to obtain a condition of balancing that is a necessary condition for
a set of isomorphism classes of combinatorial spheres to belong to the image of
the transformation L. In the present paper we give an explicit construction
providing that each balanced set of isomorphism classes of combinatorial
spheres gets into the image of L after passing to a multiple set and adding
several pairs of the form (Z,-Z), where -Z is the sphere Z with the orientation
reversed. This construction enables us, for a given singular simplicial cycle
of a space R, to construct explicitly a combinatorial manifold M and a mapping
$\phi:M\to R$ such that $\phi_*[M]=r[\xi]$ for some positive integer r. The
construction is based on resolving singularities of the cycle $\xi$. We give
applications of our main construction to cobordisms of manifolds with
singularities and cobordisms of simple cells. In particular, we prove that
every rational additive invariant of cobordisms of manifolds with singularities
admits a local formula. Another application is the construction of explicit
(though inefficient) local combinatorial formulae for polynomials in the
rational Pontryagin classes of combinatorial manifolds.


title:
Future imaging atmospheric telescopes: performance of possible array
  configurations for gamma photons in the GeV-TeV range

abstract:
  The future of ground based gamma ray astronomy lies in large arrays of
Imaging Atmospheric Cherenkov Telescopes (IACT) with better capabilities: lower
energy threshold, higher sensitivity, better resolution and background
rejection. Currently, designs for the next generation of IACT arrays are being
explored by various groups. We have studied possible configurations with a
large number of telescopes of various sizes. Here, we present the precision of
source, shower core and energy reconstruction for gamma rays in the GeV-TeV
range for different altitudes of observation. These results were obtained
through tools that we have developed in order to simulate any type of IACT
configuration and evaluate its performance.


title: Lower bounds for the number of semidualizing complexes over a local ring

abstract:
  We investigate the set S(R) of shift-isomorphism classes of semidualizing
R-complexes, ordered via the reflexivity relation, where R is a commutative
noetherian local ring. Specifically, we study the question of whether S(R$ has
cardinality 2^n for some n. We show that, if there is a chain of length n in
S(R) and if the reflexivity ordering on S(R) is transitive, then S(R) has
cardinality at least 2^n, and we explicitly describe some of its
order-structure. We also show that, given a local ring homomorphism f: R\to S
of finite flat dimension, if R and S admit dualizing complexes and if f is not
Gorenstein, then the cardinality of S(S) is at least twice the cardinality of
S(R).


title:
Jordan-Schwinger map, 3D harmonic oscillator constants of motion, and
  classical and quantum parameters characterizing electromagnetic wave
  polarization

abstract:
  In this work we introduce a generalization of the Jauch and Rohrlich quantum
Stokes operators when the arrival direction from the source is unknown {\it a
priori}. We define the generalized Stokes operators as the Jordan-Schwinger map
of a triplet of harmonic oscillators with the Gell-Mann and Ne'eman SU(3)
symmetry group matrices. We show that the elements of the Jordan-Schwinger map
are the constants of motion of the three-dimensional isotropic harmonic
oscillator. Also, we show that generalized Stokes Operators together with the
Gell-Mann and Ne'eman matrices may be used to expand the polarization density
matrix. By taking the expectation value of the Stokes operators in a three-mode
coherent state of the electromagnetic field, we obtain the corresponding
generalized classical Stokes parameters. Finally, by means of the constants of
motion of the classical three-dimensional isotropic harmonic oscillator we
describe the geometric properties of the polarization ellipse


title: Parker Problem in Hall Magnetohydrodynamics

abstract:
  Parker problem in Hall magnetohydrodynamics (MHD) is considered. Poloidal
shear into the toroidal flow generated by the Hall effect is incorporated. This
is found to lead to a {\it triple deck} structure for the Parker problem in
Hall MHD, with the magnetic field falling off in the intermediate
Hall-resistive region more steeply (like \normalfont $1/x^3$) than that (like
\normalfont$1/x$) in the outer ideal MHD region.


title:
Concerning Olga, the Beautiful Little Street Dancer (Adjectives as
  Higher-Order Polymorphic Functions)

abstract:
  In this paper we suggest a typed compositional seman-tics for nominal
compounds of the form [Adj Noun] that models adjectives as higher-order
polymorphic functions, and where types are assumed to represent concepts in an
ontology that reflects our commonsense view of the world and the way we talk
about it in or-dinary language. In addition to [Adj Noun] compounds our
proposal seems also to suggest a plausible explana-tion for well known
adjective ordering restrictions.


title: Remarks on derived equivalences of Ricci-flat manifolds

abstract:
  We present results indicating that the decomposition of a Ricci-flat manifold
in its irreducible factors is reflected by the derived category of coherent
sheaves. More precisely, we prove that a smooth projective variety that is
derived equivalent to an abelian variety resp. an irreducible symplectic
variety is of the same type.
  The paper also contains a proof of a conjecure of Caldararu for manifolds
with trivial canonical bundle saying that the modified HKR isomorphism for
Hochschild homology is compatible with the module structure.


title:
Virtual dielectric waveguide mode description of a high-gain
  free-electron laser I: Theory

abstract:
  A set of mode-coupled excitation equations for the slowly-growing amplitudes
of dielectric waveguide eigenmodes is derived as a description of the
electromagnetic signal field of a high-gain free-electron laser, or FEL,
including the effects of longitudinal space-charge. This approach of describing
the field basis set has notable advantages for FEL analysis in providing an
efficient characterization of eigenmodes, and in allowing a clear connection to
free-space propagation of the input (seeding) and output radiation. The
formulation describes the entire evolution of the radiation wave through the
linear gain regime, prior to the onset of saturation, with arbitrary initial
conditions. By virtue of the flexibility in the expansion basis, this technique
can be used to find the direct coupling and amplification of a particular mode.
A simple transformation converts the derived coupled differential excitation
equations into a set of coupled algebraic equations and yields a matrix
determinant equation for the FEL eigenmodes. A quadratic index medium is used
as a model dielectric waveguide to obtain an expression for the predicted spot
size of the dominant system eigenmode, in the approximation that it is a single
gaussian mode.


title: Swift X-ray Afterglows and the Missing Jet Break Problem

abstract:
  We present a systematic survey of the temporal and spectral properties of all
GRB X-ray afterglows observed by Swift-XRT between January 2005 and July 2007.
We have constructed a catalog of all light curves and spectra and investigate
the physical origin of each afterglow segment in the framework of the forward
shock models by comparing the data with the closure relations. We search for
possible jet-like breaks in the lightcurves and try to explain some of the
"missing" X-ray jet breaks in the lightcurves.


title: Graceful Degradation of Air Traffic Operations

abstract:
  The introduction of new technologies and concepts of operation in the air
transportation system is not possible, unless they can be proven not to
adversely affect the system operation under not only nominal, but also degraded
conditions. In extreme scenarios, degraded operations due to partial or
complete technological failures should never endanger system safety. Many past
system evolutions, whether ground-based or airborne, have been based on
trial-and-error, and system safety was addressed only after a specific event
yielded dramatic or near- dramatic consequences. Future system evolutions,
however, must leverage available computation, prior knowledge and abstract
reasoning to anticipate all possible system degradations and prove that such
degradations are graceful and safe. This paper is concerned with the graceful
degradation of high-density, structured arrival traffic against partial or
complete surveillance failures. It is shown that for equal performance
requirements, some traffic configurations might be easier to handle than
others, thereby offering a quantitative perspective on these traffic
configurations. ability to "gracefully degrade". To support our work, we also
introduce a new conflict resolution algorithm, aimed at solving conflicts
involving many aircraft when aircraft position information is in the process of
degrading.


title:
Low-Luminosity Gamma-Ray Bursts as a Distinct GRB Population:A Firmer
  Case from Multiple Criteria Constraints

abstract:
  The intriguing observations of Swift/BAT X-ray flash XRF 060218 and the
BATSE-BeppoSAX gamma-ray burst GRB 980425, both with much lower luminosity and
redshift compared to other observed bursts, naturally lead to the question of
how these low-luminosity (LL) bursts are related to high-luminosity (HL)
bursts. Incorporating the constraints from both the flux-limited samples
observed with CGRO/BATSE and Swift/BAT and the redshift-known GRB sample, we
investigate the luminosity function for both LL- and HL-GRBs through
simulations. Our multiple criteria, including the log N - log P distributions
from the flux-limited GRB sample, the redshift and luminosity distributions of
the redshift-known sample, and the detection ratio of HL- and LL- GRBs with
Swift/BAT, provide a set of stringent constraints to the luminosity function.
Assuming that the GRB rate follows the star formation rate, our simulations
show that a simple power law or a broken power law model of luminosity function
fail to reproduce the observations, and a new component is required. This
component can be modeled with a broken power, which is characterized by a sharp
increase of the burst number at around L < 10^47 erg s^-1}. The lack of
detection of moderate-luminosity GRBs at redshift ~0.3 indicates that this
feature is not due to observational biases. The inferred local rate, rho_0, of
LL-GRBs from our model is ~ 200 Gpc^-3 yr^-1 at ~ 10^47 erg s^-1, much larger
than that of HL-GRBs. These results imply that LL-GRBs could be a separate GRB
population from HL-GRBs. The recent discovery of a local X-ray transient
080109/SN 2008D would strengthen our conclusion, if the observed non-thermal
emission has a similar origin as the prompt emission of most GRBs and XRFs.


title:
Towards a Small Prototype Planet Finding Interferometer: The next step
  in planet finding and characterization in the infrared

abstract:
  During the last few years, considerable effort has been directed towards
large-scale (>> $1 Billion US) missions to detect and characterize earth-like
planets around nearby stars, such as the Terrestrial Planet Finder
Interferometer (TPF-I) and Darwin missions. However, technological and
budgetary issues as well as shifting science priorities will likely prevent
these missions from entering Phase A until the next decade. The secondary
eclipse technique using the Spitzer Space Telescope has been used to directly
measure the temperature and emission spectrum of extrasolar planets. However,
only a small fraction of known extrasolar planets are in transiting orbits.
Thus, a simplified nulling interferometer, which produces an artificial eclipse
or occultation, and operates in the near- to mid-infrared (e.g. ~ 3 to 8 or 10
microns), can characterize the atmospheres of this much larger sample of the
known but non-transiting exoplanets. Many other scientific problems can be
addressed with a system like this, including imaging debris disks, active
galactic nuclei, and low mass companions around nearby stars. We discuss the
rationale for a probe-scale mission in the $600-800 Million range, which we
name here as the Small Prototype Planet Finding Interferometer (SPPFI).


title:
Toward Best Isoperimetric Constants for $(H^1,BMO)$-Normal Conformal
  Metrics on $\mathbb R^n$, $n\ge 3$

abstract:
  The aim of this article is: (a) To establish the existence of the best
isoperimetric constants for the $(H^1,BMO)$-normal conformal metrics
$e^{2u}|dx|^2$ on $\mathbb R^n$, $n\ge 3$, i.e., the conformal metrics with the
Q-curvature orientated conditions $$ (-\Delta)^{n/2}u\in H^1(\mathbb R^n) & \
u(x)=\hbox{const.}+\frac{\int_{\mathbb
R^n}(\log\frac{|\cdot|}{|x-\cdot|})(-\Delta)^{n/2} u(\cdot)
d\mathcal{H}^n(\cdot)}{2^{n-1}\pi^{n/2}\Gamma(n/2)}; $$ (b) To prove that
$(n\omega_n^\frac1n)^\frac{n}{n-1}$ is the optimal upper bound of the best
isoperimetric constants for the complete $(H^1,BMO)$-normal conformal metrics
with nonnegative scalar curvature; (c) To find the optimal upper bound of the
best isoperimetric constants via the quotients of two power integrals of
Green's functions for the $n$-Laplacian operators $-\hbox{div}(|\nabla
u|^{n-2}\nabla u)$.


title: From Graph States to Two-Graph States

abstract:
  The name graph state is used to describe a certain class of pure quantum
state which models a physical structure on which one can perform
measurement-based quantum computing, and which has a natural graphical
description. We present the two-graph state, this being a generalisation of the
graph state and a two-graph representation of a stabilizer state.
Mathematically, the two-graph state can be viewed as a simultaneous
generalisation of a binary linear code and quadratic Boolean function. It
describes precisely the coefficients of the pure quantum state vector resulting
from the action of a member of the local Clifford group on a graph state, and
comprises a graph which encodes the magnitude properties of the state, and a
graph encoding its phase properties. This description facilitates a
computationally efficient spectral analysis of the graph state with respect to
operations from the local Clifford group on the state, as all operations can be
realised graphically. By focusing on the so-called local transform group, which
is a size 3 cyclic subgroup of the local Clifford group over one qubit, and
over $n$ qubits is of size $3^n$, we can efficiently compute spectral
properties of the graph state.


title: The Parsec-scale Accretion Disk in NGC 3393

abstract:
  We present a Very Long Baseline Interferometry image of the water maser
emission in the nuclear region of NGC3393. The maser emission has a linear
distribution oriented at a position angle of $\sim -34\degr$, perpendicular to
both the kpc-scale radio jet and the axis of the narrow line region. The
position-velocity diagram displays a red-blue asymmetry about the systemic
velocity and the estimated dynamical center, and is thus consistent with
rotation. Assuming Keplerian rotation in an edge-on disk, we obtain an enclosed
mass of $(3.1\pm 0.2) \times 10^7 M_{\sun}$ within $0.36\pm 0.02$ pc ($1.48\pm
0.06$ mas), which corresponds to a mean mass density of $\sim10^{8.2} M_{\sun}$
pc$^{-3}$. We also report the measurement with the Green Bank Telescope of a
velocity drift, a manifestation of centripetal acceleration within the disk, of
$5\pm 1$ km s $^{-1}$ yr$^{-1}$ in the $\sim3880$ km s$^{-1}$ maser feature,
which is most likely located along the line of sight to the dynamical center of
the system. From the acceleration of this feature, we estimate a disk radius of
$0.17\pm 0.02$ pc, which is smaller than the inner disk radius ($0.36\pm 0.02$
pc) of emission that occurs along the midline (i.e., the line of nodes). The
emission along the line of sight to the dynamical center evidently occurs much
closer to the center than the emission from the disk midline, contrary to the
situation in the archetypal maser systems NGC4258 and NGC1068. The outer radius
of the disk as traced by the masers along the midline is about 1.5 pc.


title: Two kinds of spin precession modes in diluted magnetic semiconductors

abstract:
  Time-resolved Kerr rotation experiments show that two kinds of spin modes
exist in diluted magnetic semiconductors: (i) coupled electron-magnetic ion
spin excitations and (ii) excitations of magnetic ion spin subsystem, which are
decoupled from electron spins. The latter modes exhibit much longer spin
coherence time and require a description, which goes beyond the mean field
approximation.


title: On Visibility in the Afshar Two-Slit Experiment

abstract:
  A modified version of Young's experiment by Shahriar Afshar indirectly
reveals the presence of a fully articulated interference pattern prior to the
post-selection of a particle in a "which-slit" basis. While this experiment
does not constitute a violation of Bohr's Complementarity Principle as claimed
by Afshar, both he and many of his critics incorrectly assume that a commonly
used relationship between visibility parameter V and "which-way" parameter K
has crucial relevance to his experiment. It is argued here that this
relationship does not apply to this experimental situation and that it is wrong
to make any use of it in support of claims for or against the bearing of this
experiment on Complementarity.