title:
An asteroseismic study of the beta Cephei star theta Ophiuchi:
  constraints on global stellar parameters and core overshooting

abstract:
  We present a seismic study of the beta Cephei star theta Ophiuchi. Our
analysis is based on the observation of one radial mode, one rotationally split
l = 1 triplet and three components of a rotationally split l = 2 quintuplet for
which the m-values were well identified by spectroscopy. We identify the radial
mode as fundamental, the triplet as p_1 and the quintuplet as g_1. Our NLTE
abundance analysis results in a metallicity and CNO abundances in full
agreement with the most recent updated solar values. With X \in [0.71,0.7211]
and Z \in [0.009,0.015], and using the Asplund et al. (2005) mixture but with a
Ne abundance about 0.3 dex larger (Cunha et al. 2006), the matching of the
three independent modes, enables us to deduce constrained ranges for the mass
(M = 8.2 +/- 0.3 Msun) and central hydrogen abundance (X_c = 0.38 +/- 0.02) of
theta Oph and to prove the occurrence of core overshooting (alpha_ov = 0.44 +/-
0.07). We also derive an equatorial rotation velocity of 29 +/- 7 km/s.
Moreover, we show that the observed non-equidistance of the l=1 triplet can be
reproduced by second order effects of rotation. Finally, we show that the
observed rotational splitting of two modes cannot rule out a rigid rotation
model.


title: Quantum rattling of molecular hydrogen in clathrate hydrate nanocavities

abstract:
  We have performed high-resolution inelastic neutron scattering studies on
three samples of hydrogenated tetrahydrofuran-water clathrates, containing
either H2 at different para/ortho concentrtion, or HD. By a refined analysis of
the data, we are able to assign the spectral bands to rotational and
center-of-mass translational transitions of either para- or ortho-H2. The H2
molecule rotates almost freely, while performing a translational motion
(rattling) in the nanometric-size cage, resulting a paradigmatic example of
quantum dynamics in a non-harmonic potential well. Both the H2 rotational
transition and the fundamental of the rattling transition split into triplets,
having different separation. The splitting is a consequence of a substantial
anisotropy of the environment with respect to the orientation of the molecule
in the cage, in the first case, or with respect to the center-of-mass position
inside the cage, in the second case. The values of the transition frequencies
and band intensities have been quantitatively related to the details of the
interaction potential between H2 and the water molecules, with a very good
agreement.


title: The ratchet effect and the transporting islands in the chaotic sea

abstract:
  We study directed transport in a classical deterministic dissipative system.
We consider the generic case of mixed phase space and show that large ratchet
currents can be generated thanks to the presence, in the Hamiltonian limit, of
transporting stability islands embedded in the chaotic sea. Due to the
simultaneous presence of chaos and dissipation the stationary value of the
current is independent of initial conditions, except for initial states with
very small measure.


title:
High redshift X-ray galaxy clusters. II. The L_X-T relationship
  revisited

abstract:
  In this paper we re-visit the observational relation between X-ray luminosity
and temperature for high-z galaxy clusters and compare it with the local L_X-T
and with theoretical models. To these ends we use a sample of 17 clusters
extracted from the Chandra archive supplemented with additional clusters from
the literature, either observed by Chandra or XMM-Newton, to form a final
sample of 39 high redshift (0.25 < z < 1.3) objects. Different statistical
approaches are adopted to analyze the L_X-T relation. The slope of the L_X-T
relation of high redshift clusters is steeper than expected from the
self-similar model predictions and steeper, even though still compatible within
the errors, than the local L_X-T slope. The distant cluster L_X-T relation
shows a significant evolution with respect to the local Universe: high-z
clusters are more luminous than the local ones by a factor ~2 at any given
temperature. The evolution with redshift of the L_X-T relation cannot be
described by a single power law nor by the evolution predicted by the
self-similar model. We find a strong evolution, similar or stronger than the
self-similar model, from z = 0 to z <0.3 followed by a much weaker, if any,
evolution at higher redshift. The weaker evolution is compatible with
non-gravitational models of structure formation. According to us a
statistically significant sample of nearby clusters (z < 0.25) should be
observed with the current available X-ray telescopes to completely exclude
observational effects due to different generation detectors and to understand
this novel result.


title: Simulations on the Heavy Hadron Transport at RHIC

abstract:
  Based on the hadron transport frames, detailed simulations are carried out to
discuss $\phi$, $\Omega$ productions and the significant enhancements in the
very low $p_T$ region for some of the soft spectra in RHIC. Elastic
interactions are introduced in the simulations. The elastic cross sections vary
from different hadrons and energy scales, which can qualitatively explain the
different collective motions of various hadrons.


title:
Measurement of the Branching Fraction for B^0 --> a1(1260)+-pi-+ with
  535 Million BBbar Pairs

abstract:
  We present a measurement of the branching fraction for the decay
B^0->a1+(1260)pi- with a1+->pi+pi+pi- using a data sample containing 535x10^6
BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy
e+e- collider operating at the Upsilon(4S) resonance. We measure the branching
fraction Br(B^0->a1+pi-)Br(a1+->pi+pi+pi-) = (14.9 +- 1.6 +- 2.3)x10^-6, where
the first and second errors are statistical and systematic, respectively.


title:
Theoretical background for observing ultra-slow microwaves in a
  Bose-Einstein condensate of alkali atoms

abstract:
  We represent a new microscopic approach that allows studying the propagation
properties of microwaves in a Bose-Einstein condensate of alkali atoms. It is
assumed that the frequency of signal is tuned up to the transition between
hyperfine ground state levels of such atoms. Pulse slowing conditions
dependence on the system parameters is found. It is shown that the slowed
signal can propagate in mentioned system with rather small energy loss. Such
phenomenon is also studied in case of hyperfine levels Zeeman splitting. A
possibility of ultra-slow microwaves observing in a condensed gas of cesium
atoms is discussed.


title:
Optical and infrared properties of V1647 Orionis during the 2003-2006
  outburst. II. Temporal evolution of the eruptive source

abstract:
  The occurrence of new FU Orionis-like objects is fundamental to understand
the outburst mechanism in young stars and their role in star formation and disk
evolution. Our work is aimed at investigating the properties of the recent
outburst of V1647 Ori. Using optical and mid infrared long slit spectroscopy we
monitored V1647 Ori in outburst between February 2004 and January 2006. The
optical spectrum is characterized by Halpha and Hbeta in P-Cygni profile and by
many weak FeI and FeII emission lines. Short timescale variability was measured
in the continuum and line emission. On January 2006 we detected for the first
time forbidden emission lines ([OI], [SII] and [FeII]). These lines are likely
produced by an Herbig-Haro object driven by V1647 Ori. The mid infrared the
spectrum of V1647 Ori is flat and featureless at all epochs. The SED changed
drastically: the source was much redder in the early outburst than in the final
phase. The magnitude rise and the SED of V1647 Ori resembles that of a FUor
while the duration and recurrence of the outburst resemble that of a EXor. The
optical spectrum is clearly distinct from either the absorption line spectrum
of a FUor or the T Tauri-like spectrum of an EXor. Our data are consistent with
a disk instability event which led to an increase of the mass accretion rate.
The data also suggest the presence of a circumstellar envelope around the
star+disk system. The peculiar N band spectrum might be explained by dust
sublimation in the outer layers of the disk. The presence of the envelope and
the outburst statistics suggest that these instability events occur only in a
specific stage of a Class I source (e.g. in the transition phase to an
optically visible star surrounded by a protoplanetary disk). We discuss the
outburst mechanisms in term of the thermal instability model.


title: Braided Hom-Lie bialgebras

abstract:
  We introduce the new concept of braided Hom-Lie bialgebras which is a
generalization of Sommerh\"{a}user-Majid's braided Lie bialgebras and Yau's
Hom-Lie bialgebras. Using this concept we give the unified product construction
for Hom-Lie bialgebras which can be seen as a Hom-Lie version of
Bespalov-Drabant's cocycle cross product bialgebras. Some special cases of
unified products such as crossed product and matched pair of braided Hom-Lie
bialgebras are investigated. As an application, we solve the Agore-Militaru
extending problem for Hom-Lie bialgebras by using some non-abelian cohomology
theory. Furthermore, one dimensional flag extending structures for Hom-Lie
bialgebras are also investigated.


title:
Novel constraints on light elementary particles and extra-dimensional
  physics from the Casimir effect

abstract:
  We present supplementary information on the recent indirect measurement of
the Casimir pressure between two parallel plates using a micromachined
oscillator. The equivalent pressure between the plates is obtained by means of
the proximity force approximation after measuring the force gradient between a
gold coated sphere and a gold coated plate. The data are compared with a new
theoretical approach to the thermal Casimir force based on the use of the
Lifshitz formula, combined with a generalized plasma-like dielectric
permittivity which takes into account interband transitions of core electrons.
The theoretical Casimir pressures calculated using the new approach are
compared with those computed in the framework of the previously used impedance
approach and also with the Drude model approach. The latter is shown to be
excluded by the data at a 99.9% confidence level within a wide separation range
from 210 to 620 nm. The level of agreement between the data and theoretical
approaches based on the generalized plasma model, or the Leontovich surface
impedance, is used to set stronger constraints on the Yukawa forces predicted
from the exchange of light elementary particles and/or extra-dimensional
physics. The resulting constraints are the strongest in the interaction region
from 20 to 86 nm with a largest improvement by a factor of 4.4 at 26 nm.


title: The role of string topology in symplectic field theory

abstract:
  We outline a program for incorporating holomorphic curves with Lagrangian
boundary conditions into symplectic field theory, with an emphasis on ideas,
geometric intuition, and a description of the resulting algebraic structures.


title: Quark Mass in the Sakai-Sugimoto Model of Chiral Symmetry Breaking

abstract:
  We re-analyze D8 brane embeddings in the geometry of a D4 brane wrapped on a
circle that describe chiral symmetry breaking in a strongly coupled
non-supersymmetric gauge theory. We argue that if the holographic fields are
correctly interpreted, the original embeddings describe a complex quark mass
and condensate in the theory. We show that in this interpretation when a quark
mass is present there is a massive pseudo Goldstone boson (pion). A previously
identified massless fluctuation is, we argue, not a physical state in the field
theory. We also determine the behaviour of the quark condensate as a function
of the quark mass.


title:
Intensity-Based Registration of Freehand 3D Ultrasound and CT-scan
  Images of the Kidney

abstract:
  This paper presents a method to register a pre-operative Computed-Tomography
(CT) volume to a sparse set of intra-operative Ultra-Sound (US) slices. In the
context of percutaneous renal puncture, the aim is to transfer planning
information to an intra-operative coordinate system. The spatial position of
the US slices is measured by optically localizing a calibrated probe. Assuming
the reproducibility of kidney motion during breathing, and no deformation of
the organ, the method consists in optimizing a rigid 6 Degree Of Freedom (DOF)
transform by evaluating at each step the similarity between the set of US
images and the CT volume. The correlation between CT and US images being
naturally rather poor, the images have been preprocessed in order to increase
their similarity. Among the similarity measures formerly studied in the context
of medical image registration, Correlation Ratio (CR) turned out to be one of
the most accurate and appropriate, particularly with the chosen non-derivative
minimization scheme, namely Powell-Brent's. The resulting matching transforms
are compared to a standard rigid surface registration involving segmentation,
regarding both accuracy and repeatability. The obtained results are presented
and discussed.


title: Evolution of the proton sd states in neutron-rich Ca isotopes

abstract:
  We analyze the evolution with increasing isospin asymmetry of the proton
single-particle states 2s1/2 and 1d3/2 in Ca isotopes, using non-relativistic
and relativistic mean field approaches. Both models give similar trends and it
is shown that this evolution is sensitive to the neutron shell structure, the
two states becoming more or less close depending on the neutron orbitals which
are filled. In the regions where the states get closer some parametrizations
predict an inversion between them. This inversion occurs near $^{48}$Ca as well
as very far from stability where the two states systematically cross each other
if the drip line predicted in the model is located far enough. We study in
detail the modification of the two single-particle energies by using the
equivalent potential in the Schroedinger-like Skyrme-Hartree-Fock equations.
The role played by central, kinetic and spin-orbit contributions is discussed.
We finally show that the effect of a tensor component in the effective
interaction considerably favors the inversion of the two proton states in
$^{48}$Ca.


title:
Alternative experimental evidence for chiral restoration in excited
  baryons

abstract:
  Given existing empirical spectral patterns of excited hadrons it has been
suggested that chiral symmetry is approximately restored in excited hadrons at
zero temperature/density (effective symmetry restoration). If correct, this
implies that mass generation mechanisms and physics in excited hadrons is very
different as compared to the lowest states. One needs an alternative and
independent experimental information to confirm this conjecture. Using very
general chiral symmetry arguments it is shown that strict chiral restoration in
a given excited nucleon forbids its decay into the N \pi channel. Hence those
excited nucleons which are assumed from the spectroscopic patterns to be in
approximate chiral multiplets must only "weakly" decay into the N \pi channel,
(f_{N^*N\pi}/f_{NN\pi})^2 << 1. However, those baryons which have no chiral
partner must decay strongly with a decay constant comparable with f_{NN\pi}.
Decay constants can be extracted from the existing decay widths and branching
ratios. It turnes out that for all those well established excited nucleons
which can be classified into chiral doublets N_+(1440) - N_-(1535), N_+(1710) -
N_-(1650), N_+(1720) - N_-(1700), N_+(1680) - N_-(1675), N_+(2220) - N_-(2250),
N_+(?) - N_-(2190), N_+(?) - N_-(2600), the ratio is (f_{N^*N\pi}/f_{NN\pi})^2
~ 0.1 or much smaller for the high-spin states. In contrast, the only well
established excited nucleon for which the chiral partner cannot be identified
from the spectroscopic data, N(1520), has a decay constant into the N\pi
channel that is comparable with f_{NN\pi}. This gives an independent
experimental verification of the chiral symmetry restoration scenario.


title:
Single-qubit operations in the double-donor structure driven by optical
  and voltage pulses

abstract:
  We study theoretically the quantum dynamics of an electron in the
singlyionized double-donor structure in the semiconductor host under the
influence of laser pulses whose frequencies are close to structure resonant
frequencies. This system can be used as a charge qubit where the logical states
are defined by the lowest two energy states of the remaining valence electron
localized around one or another donor. The quantum operations are performed via
resonant or Raman-like transitions between the localized (qubit) states and the
excited states delocalized over the structure, combined with phase shifts
between qubit states generated by voltage pulses. The possibility of
realization of arbitrary single-qubit rotations is demonstrated.


title:
Multiplicity Distributions in Canonical and Microcanonical Statistical
  Ensembles

abstract:
  The aim of this paper is to introduce a new technique for calculation of
observables, in particular multiplicity distributions, in various statistical
ensembles at finite volume. The method is based on Fourier analysis of the
grand canonical partition function. Taylor expansion of the generating function
is used to separate contributions to the partition function in their power in
volume. We employ Laplace's asymptotic expansion to show that any equilibrium
distribution of multiplicity, charge, energy, etc. tends to a multivariate
normal distribution in the thermodynamic limit. Gram-Charlier expansion allows
additionally for calculation of finite volume corrections. Analytical formulas
are presented for inclusion of resonance decay and finite acceptance effects
directly into the system partition function. This paper consolidates and
extends previously published results of current investigation into properties
of statistical ensembles.


title:
Continuous Spin Fractionation: A large scale method to improve the
  performance of polymers

abstract:
  Most technical polymers and many biopolymers contain very different molecular
species (unlike chain length, molecular architecture and/or chemical
composition) in contrast to pure low molecular weight compounds. This
inconsistent constitution of macromolecules proves very adverse in many cases.
An adequate fractionation of polydisperse polymers is therefore mandatory.
  Very efficient means are available for analytical purposes. However, these
methods break down as soon as the required amount of product exceeds some ten
grams. In order to gain access to large enough quantities of sufficiently
uniform polymer samples, we have developed a special kind of extraction process
called Continuous Spin Fractiona-tion (CSF). The better soluble macromolecular
species are preferentially transferred from a feed phase (concentrated polymer
solution) into a pickup phase (solvent of tai-lored thermodynamic quality). The
main problem of the procedure lies in the high vis-cosities of reasonably
concentrated polymer solutions, impeding the attainment of ther-modynamic
equilibria. This hurdle could be cleared by means of spinning nozzles through
which the feed is pressed into the pickup phase. CSF can be implemented to any
soluble polymer and is likewise apt for the production of small and of large
amounts of polymer samples with the required uniformity. This contribution
explains how to customize CSF to the polymer of interest and presents a number
of typical ex-amples.


title:
A Differential Model for the Deformation of the Plancherel Growth
  Process

abstract:
  In the present paper we construct and solve a differential model for the
q-analog of the Plancherel growth process. The construction is based on a
deformation of the Makrov-Krein correspondence between continual diagrams and
probability distributions.


title: Optimized implementation of the Lanczos method for magnetic systems

abstract:
  Numerically exact investigations of interacting spin systems provide a major
tool for an understanding of their magnetic properties. For medium size systems
the approximate Lanczos diagonalization is the most common method. In this
article we suggest two improvements: efficient basis coding in subspaces and
simple restructuring for openMP parallelization.


title:
Moriond 07 proceedings:"Extension of the frequency-range of
  interferometers for the "magnetic" components of gravitational waves?"

abstract:
  Recently some papers in the literature have shown the presence and importance
of the so-called {}"magnetic" components of gravitational waves (GWs), which
have to be taken into account in the context of the total response functions of
interferometers for GWs propagating from arbitrary directions. In this paper
the response functions for the magnetic components are re-analysed in the full
frequency dependence answering to the question of the title.


title: Lower bounds on the minimum average distance of binary codes

abstract:
  New lower bounds on the minimum average Hamming distance of binary codes are
derived. The bounds are obtained using linear programming approach.


title: On the heterogeneous character of water's amorphous polymorphism

abstract:
  In this letter we report {\it in situ} small--angle neutron scattering
results on the high--density (HDA) and low-density amorphous (LDA) ice
structures and on intermediate structures as found during the temperature
induced transformation of HDA into LDA. We show that the small--angle signal is
characterised by two $Q$ regimes featuring different properties ($Q$ is the
modulus of the scattering vector defined as $Q =
4\pi\sin{(\Theta)}/\lambda_{\rm i}$ with $\Theta$ being half the scattering
angle and $\lambda_{\rm i}$ the incident neutron wavelength). The very low--$Q$
regime ($< 5\times 10^{-2}$ \AA $^{-1}$) is dominated by a Porod--limit
scattering. Its intensity reduces in the course of the HDA to LDA
transformation following a kinetics reminiscent of that observed in wide--angle
diffraction experiments. The small--angle neutron scattering formfactor in the
intermediate regime of $5 \times 10^{-2} < Q < 0.5$ \AA$^{-1}$ HDA and LDA
features a rather flat plateau. However, the HDA signal shows an ascending
intensity towards smaller $Q$ marking this amorphous structure as
heterogeneous. When following the HDA to LDA transition the formfactor shows a
pronounced transient excess in intensity marking all intermediate structures as
strongly heterogeneous on a length scale of some nano--meters.


title: Higher Mellin moments for charged current DIS

abstract:
  We report on our recent results for deep-inelastic neutrino-proton
scattering. We have computed the perturbative QCD corrections to three loops
for the harged current structure functions F_2, F_L and F_3 for the combination
nu P - nubar P. In leading twist approximation we have calculated the first six
odd-integer Mellin moments in the case of F_2 and F_L and the first six
even-integer moments in the case of F_3. As a new result we have obtained the
coefficient functions to O(alpha_s^3) and we have found the corresponding
anomalous dimensions to agree with known results in the literature.


title:
On geodesics of Berger tangent sphere bundle of Hermitian locally
  symmetric manifold

abstract:
  We propose a special deformation of the Sasaki metric on tangent and unit
tangent bundle of a Hermitian locally symmetric manifold. Geodesics of this
deformed metric have different projections on a base manifold for tangent or
unit tangent bundle cases in contrast to usual Sasaki metric. Nevertheless, the
projections of geodesics of the unit tangent bundle still preserve the property
to have all geodesic curvatures constant.


title:
Relaxation of the flow of triods by Curve Shortening Flow via the
  vector-valued parabolic Allen-Cahn equation

abstract:
  In this paper we find solutions $u_\epsilon$ to a certain class of
vector-valued parabolic Allen-Cahn equation that as $\epsilon \to 0$ develops
as interface a given triod evolving under curve shortening flow.


title: Trapped Bose gases with large positive scattering length

abstract:
  We calculate the energy and the condensate fraction of a system of trapped
bosons interacting via a short-range two-body potential with positive
scattering length. The potential is attractive and has a two-body bound state.
When the scattering length is small compared to the trap length the system is
model independent: all potential models -- attractive, repulsive and zero-range
-- provide similar results. When the scattering length is large the attractive
model differs qualitatively from the repulsive and zero-range models. In this
regime the system with attractive potential becomes independent of the
scattering length, with both the energy and the condensate fraction converging
towards finite constants.


title: On the invariant symmetries of the $\mathcal{D}$-metrics

abstract:
  We analyze the symmetries and other invariant qualities of the
$\mathcal{D}$-metrics (type D aligned Einstein Maxwell solutions with
cosmological constant whose Debever null principal directions determine
shear-free geodesic null congruences). We recover some properties and deduce
new ones about their isometry group and about their quadratic first integrals
of the geodesic equation, and we analyze when these invariant symmetries
characterize the family of metrics. We show that the subfamily of the Kerr-NUT
solutions are those admitting a Papapetrou field aligned with the Weyl tensor.


title: Zero-point momentum in Complex media

abstract:
  In this work we apply field regularization techniques to formulate a number
of new phenomena related to momentum induced by electromagnetic zero-point
fluctuations. We discuss the zero-point momentum associated with
magneto-electric media, with moving media, and with magneto-chiral media.


title: Soft colour interactions in hadron-hadron hard diffraction

abstract:
  SCI model gives a good and natural description of DDIS cross-sections.
Howevere, this model is pure phenomenological, and does not explain the nature
of soft color rearrangment. In this paper we argue, that the most capabilities
of SCI model can be derived from low constituent model and overview
applicability of low constituent model to DDIS processes.


title: Standard Model and Gravity from Spinors

abstract:
  We propose to unify the Gravity and Standard Model gauge groups by using
algebraic spinors of the standard four-dimensional Clifford algebra, in
left-right symmetric fashion. This generates exactly a Standard Model family of
fermions, and a Pati-Salam unification group emerges, at the Planck scale,
where (chiral) self-dual gravity decouples. As a remnant of the unification,
isospin-triplets spin-two particles may naturally appear at the weak scale,
providing a striking signal at the LHC.


title:
A simple generalization of the ElGamal cryptosystem to non-abelian
  groups II

abstract:
  This is a study of the MOR cryptosystem using the special linear group over
finite fields. The automorphism group of the special linear group is analyzed
for this purpose. At our current state of knowledge, I show that the MOR
cryptosystem has better security than the ElGamal cryptosystem over finite
fields.


title:
Theoretical studies of high-harmonic generation: Effects of symmetry,
  degeneracy and orientation

abstract:
  Using a quantum mechanical three-step model we present numerical calculations
on the high-harmonic generation from four polyatomic molecules. Ethylene
(C$_2$H$_4$) serves as an example where orbital symmetry directly affects the
harmonic yield. We treat the case of methane (CH$_4$) to address the
high-harmonic generation resulting from a molecule with degenerate orbitals. To
this end we illustrate how the single orbital contributions show up in the
total high-harmonic signal. This example illustrates the importance of adding
coherently amplitude contributions from the individual degenerate orbitals.
Finally, we study the high-harmonic generation from propane (C$_3$H$_8$) and
butane (C$_4$H$_{10}$). These two molecules, being extended and far from
spherical in structure, produce harmonics with non-trivial orientational
dependencies. In particular, propane can be oriented so that very
high-frequency harmonics are favorized, and thus the molecule contains
prospects for the generation of UV attosecond pulses.


title: Graviweak Unification

abstract:
  The coupling of chiral fermions to gravity makes use only of the selfdual
SU(2) subalgebra of the (complexified) SO(3,1) algebra. It is possible to
identify the antiselfdual subalgebra with the SU(2)_L isospin group that
appears in the Standard Model, or with its right-handed counterpart SU(2)_R
that appears in some extensions. Based on this observation, we describe a form
of unification of the gravitational and weak interactions. We also discuss
models with fermions of both chiralities, the inclusion strong interactions,
and the way in which these unified models of gravitational and gauge
interactions avoid conflict with the Coleman-Mandula theorem.


title:
Simulating the formation and evolution of galaxies: Multi-phase
  description of the interstellar medium, star formation, and energy feedback

abstract:
  We present a multi-phase representation of the ISM in NB-TSPH simulations of
galaxy formation and evolution with particular attention to the case of
early-type galaxies. Cold gas clouds are described by the so-called sticky
particles algorithm. They can freely move throughout the hot ISM medium; stars
form within these clouds and the mass exchange among the three baryonic phases
(hot gas, cold clouds, stars) is governed by radiative and Compton cooling and
energy feedback by supernova (SN) explosions, stellar winds, and UV radiation.
We also consider thermal conduction, cloud-cloud collisions, and chemical
enrichment. Our model agrees with and improves upon previous studies on the
same subject. The results for the star formation rate are very promising and
agree with recent observational data on early-type galaxies. These models lend
further support to the revised monolithic scheme of galaxy formation, which has
recently been also strengthened by high redshift data leading to the so-called
downsizing and top-down scenarios.


title: Variational methods in relativistic quantum mechanics

abstract:
  This review is devoted to the study of stationary solutions of linear and
nonlinear equations from relativistic quantum mechanics, involving the Dirac
operator. The solutions are found as critical points of an energy functional.
Contrary to the Laplacian appearing in the equations of nonrelativistic quantum
mechanics, the Dirac operator has a negative continuous spectrum which is not
bounded from below. This has two main consequences. First, the energy
functional is strongly indefinite. Second, the Euler-Lagrange equations are
linear or nonlinear eigenvalue problems with eigenvalues lying in a spectral
gap (between the negative and positive continuous spectra). Moreover, since we
work in the space domain R^3, the Palais-Smale condition is not satisfied. For
these reasons, the problems discussed in this review pose a challenge in the
Calculus of Variations. The existence proofs involve sophisticated tools from
nonlinear analysis and have required new variational methods which are now
applied to other problems.


title: Josephson-Like Behaviour of Granular Carbon Films

abstract:
  This work presents the study of some new anomalous electromagnetic effects in
graphite-like thin carbon films. These are: The fast switching (1nanosecond) of
electrical conductivity The detection of microwave radiation and its
temperature dependence The oscillations of film stack magnetization in the
magnetic field of 1-5 T. The optical radiation under process of spasmodic
switching of conductivity Results of magnetic force microscopy (MFM), DC SQUID
magnetization, reversed Josephson effect (RJE), and resistance measurements in
thin carbon arc (CA) films are presented. The observation of a RJE induced
voltage as well as its rf frequency, input amplitude, and temperature
dependence reveals the existence of Josephson-like Junction arrays. Oscillating
behavior of the DC SQUID magnetization reminiscent of the Fraunhofer-like
behavior of superconducting (SC) critical current in the range of 10000-50000
Oe has been observed. The DC SQUID magnetization measurement indicates a
possible elementary 102 nm SC loop; this is compared to MFM direct observations
of magnetic clusters with a median size of 165 nm. The results obtained
provides a basis for non-cryogenic elecrtonic devices utilizing the Josephson
effect.


title: Blue straggler stars in dwarf spheroidal galaxies

abstract:
  Blue straggler star (BSS) candidates have been observed in all old dwarf
spheroidal galaxies (dSphs), however whether or not they are authentic BSSs or
young stars has been a point of debate. To both address this issue and obtain a
better understanding of the formation of BSSs in different environments we have
analysed a sample of BSS candidates in two nearby Galactic dSphs, Draco and
Ursa Minor. We have determined their radial and luminosity distributions from
wide field multicolour imaging data extending beyond the tidal radii of both
galaxies.
  BSS candidates are uniformly distributed through the host galaxy, whereas a
young population is expected to show a more clumpy distribution. Furthermore,
the observed radial distribution of BSSs, normalized to both red giant branch
(RGB) and horizontal branch (HB) stars, is almost flat, with a slight decrease
towards the centre. Such a distribution is at odds with the predictions for a
young stellar population, which should be more concentrated. Instead, it is
consistent with model predictions for BSS formation by mass transfer in
binaries (MT-BSSs). Such results, although not decisive, suggest that these
candidates are indeed BSSs and that MT-BSSs form in the same way in Draco and
Ursa Minor as in globular clusters. This favours the conclusion that Draco and
Ursa Minor are truly 'fossil' galaxies, where star formation ceased completely
more than 8 billion years ago.


title: Two-flow magnetohydrodynamical jets around young stellar objects

abstract:
  We present the first-ever simulations of non-ideal magnetohydrodynamical
(MHD) stellar winds coupled with disc-driven jets where the resistive and
viscous accretion disc is self-consistently described. The transmagnetosonic,
collimated MHD outflows are investigated numerically using the VAC code. Our
simulations show that the inner outflow is accelerated from the central object
hot corona thanks to both the thermal pressure and the Lorentz force. In our
framework, the thermal acceleration is sustained by the heating produced by the
dissipated magnetic energy due to the turbulence. Conversely, the outflow
launched from the resistive accretion disc is mainly accelerated by the
magneto-centrifugal force. We also show that when a dense inner stellar wind
occurs, the resulting disc-driven jet have a different structure, namely a
magnetic structure where poloidal magnetic field lines are more inclined
because of the pressure caused by the stellar wind. This modification leads to
both an enhanced mass ejection rate in the disc-driven jet and a larger radial
extension which is in better agreement with the observations besides being more
consistent.


title: Parity properties of Costas arrays defined via finite fields

abstract:
  A Costas array of order $n$ is an arrangement of dots and blanks into $n$
rows and $n$ columns, with exactly one dot in each row and each column, the
arrangement satisfying certain specified conditions. A dot occurring in such an
array is even/even if it occurs in the $i$-th row and $j$-th column, where $i$
and $j$ are both even integers, and there are similar definitions of odd/odd,
even/odd and odd/even dots. Two types of Costas arrays, known as Golomb-Costas
and Welch-Costas arrays, can be defined using finite fields. When $q$ is a
power of an odd prime, we enumerate the number of even/even odd/odd, even/odd
and odd/even dots in a Golomb-Costas array. We show that three of these numbers
are equal and they differ by $\pm 1$ from the fourth. For a Welch-Costas array
of order $p-1$, where $p$ is an odd prime, the four numbers above are all equal
to $(p-1)/4$ when $p\equiv 1\pmod{4}$, but when $p\equiv 3\pmod{4}$, we show
that the four numbers are defined in terms of the class number of the imaginary
quadratic field $\mathbb{Q}(\sqrt{-p})$, and thus behave in a much less
predictable manner.


title:
Structure of W3(OH) from Very High Spectral Resolution Observations of 5
  Centimeter OH Masers

abstract:
  Recent studies of methanol and ground-state OH masers at very high spectral
resolution have shed new light on small-scale maser processes. The nearby
source W3(OH), which contains numerous bright masers in several different
transitions, provides an excellent laboratory for high spectral resolution
techniques. We present a model of W3(OH) based on EVN observations of the
rotationally-excited 6030 and 6035 MHz OH masers taken at 0.024 km/s spectral
resolution. The 6.0 GHz masers are becoming brighter with time and show
evidence for tangential proper motions. We confirm the existence of a region of
magnetic field oriented toward the observer to the southeast and find another
such region to the northeast in W3(OH), near the champagne flow. The 6.0 GHz
masers trace the inner edge of a counterclockwise rotating torus feature.
Masers at 6030 MHz are usually a factor of a few weaker than at 6035 MHz but
trace the same material. Velocity gradients of nearby Zeeman components are
much more closely correlated than in the ground state, likely due to the
smaller spatial separation between Zeeman components. Hydroxyl maser peaks at
very long baseline interferometric resolution appear to have structure on
scales both smaller than that resolvable as well as on larger scales.


title: pi0 Fixed pT suppression and elliptic flow at LHC

abstract:
  Using a final state interaction model which describes the data on these two
observables, at RHIC, we make predictions at the LHC -- using the same
cross-section and pT-shift. The increase in the medium density between these
two energies (by a factor close to three) produces an increase of the fixed pT
pi0 suppression by a factor 2 at large pT and of v2 by a factor 1.5.


title:
Hadron beam test of a scintillating fibre tracker system for elastic
  scattering and luminosity measurement in ATLAS

abstract:
  A scintillating fibre tracker is proposed to measure elastic proton
scattering at very small angles in the ATLAS experiment at CERN. The tracker
will be located in so-called Roman Pot units at a distance of 240 m on each
side of the ATLAS interaction point. An initial validation of the design
choices was achieved in a beam test at DESY in a relatively low energy electron
beam and using slow off-the-shelf electronics. Here we report on the results
from a second beam test experiment carried out at CERN, where new detector
prototypes were tested in a high energy hadron beam, using the first version of
the custom designed front-end electronics. The results show an adequate
tracking performance under conditions which are similar to the situation at the
LHC. In addition, the alignment method using so-called overlap detectors was
studied and shown to have the expected precision.


title:
Detecting phase synchronization by localized maps: Application to neural
  networks

abstract:
  We present an approach which enables to state about the existence of phase
synchronization in coupled chaotic oscillators without having to measure the
phase. This is done by observing the oscillators at special times, and
analyzing whether this set of points is localized. In particular, we show that
this approach is fruitful to analyze the onset of phase synchronization in
chaotic attractors whose phases are not well defined, as well as, in networks
of non-identical spiking/bursting neurons connected by chemical synapses.


title: Invariance of Gamma-dimension for projective families

abstract:
  This article is withdrawn because of a mistake in the main result of the
paper.


title: On the Photon Mass

abstract:
  We review the case for the photon having a tiny mass compatible with the
experimental limits. We go over some possible experimental tests for such a
photon mass including the violation of Lorentz symmetry. We point out that such
violations may already have been witnessed in tests involving high energy gamma
rays from outer space as also ultra high energy cosmic rays.


title: General Framework for phase synchronization through localized sets

abstract:
  We present an approach which enables to identify phase synchronization in
coupled chaotic oscillators without having to explicitly measure the phase. We
show that if one defines a typical event in one oscillator and then observes
another one whenever this event occurs, these observations give rise to a
localized set. Our result provides a general and easy way to identify PS, which
can also be used to oscillators that possess multiple time scales. We
illustrate our approach in networks of chemically coupled neurons. We show that
clusters of phase synchronous neurons may emerge before the onset of phase
synchronization in the whole network, producing a suitable environment for
information exchanging. Furthermore, we show the relation between the localized
sets and the amount of information that coupled chaotic oscillator can
exchange.


title:
Elastoplastic model for the dynamics of solid-solid transformations :
  role of non-affine deformation in microstructure selection

abstract:
  We study the nucleation dynamics of a model solid state transformation and
the criterion for microstructure selection using a molecular dynamics (MD)
simulation. Our simulations show a range of microstructures depending on the
depth of quench. We closely follow the dynamics of the solid and find that
transient {\em non-affine zones} (NAZ) are created at and evolve with the
rapidly moving transformation front. The dynamics of these plastic regions
determines the selection of microstructure. We formulate an {\it elastoplastic
model} which couples the elastic strain to the non-affine deformation, and
recover all the qualitative features of the MD simulation. Using this model, we
construct a dynamical phase diagram for microstructure selection, in addition
to making definite testable predictions.


title:
Distance distribution in random graphs and application to networks
  exploration

abstract:
  We consider the problem of determining the proportion of edges that are
discovered in an Erdos-Renyi graph when one constructs all shortest paths from
a given source node to all other nodes. This problem is equivalent to the one
of determining the proportion of edges connecting nodes that are at identical
distance from the source node. The evolution of this quantity with the
probability of existence of the edges exhibits intriguing oscillatory behavior.
In order to perform our analysis, we introduce a new way of computing the
distribution of distances between nodes. Our method outperforms previous
similar analyses and leads to estimates that coincide remarkably well with
numerical simulations. It allows us to characterize the phase transitions
appearing when the connectivity probability varies.


title: Onset of Phase Synchronization in Neurons Conneted via Chemical Synapses

abstract:
  We study the onset of synchronous states in realistic chaotic neurons coupled
by mutually inhibitory chemical synapses. For the realistic parameters, namely
the synaptic strength and the intrinsic current, this synapse introduces
non-coherences in the neuronal dynamics, yet allowing for chaotic phase
synchronization in a large range of parameters. As we increase the synaptic
strength, the neurons undergo to a periodic state, and no chaotic complete
synchronization is found.


title:
Network Mutual Information and Synchronization under Time
  Transformations

abstract:
  We investigate the effect of general time transformations on the phase
synchronization (PS) phenomenon and the mutual information rate (MIR) between
pairs of nodes in dynamical networks. We demonstrate two important results
concerning the invariance of both PS and the MIR. Under time transformations PS
can neither be introduced nor destroyed and the MIR cannot be raised from zero.
On the other hand, for proper time transformations the timing between the
cycles of the coupled oscillators can be largely improved. Finally, we discuss
the relevance of our findings for communication in dynamical networks.


title: Global Bifurcation Destroying The Experimental Torus T2

abstract:
  We show experimentally the scenario of a two-frequency torus $T^2$ breakdown,
in which a global bifurcation occurs due to the collision of a torus with an
unstable periodic orbit, creating a heteroclinic saddle connection, followed by
an intermittent behavior.


title: Three-qubit pure-state canonical forms for Perfect Teleportation

abstract:
  Recently, Agrawal and Pati [Phys. Rev. A 74, 062320 (2006)] have given a
class of W-states that can be used for perfect teleportation. Here, two
canonical forms of perfect quantum channel are presented by transformation
operator and the GHZ state and the W state are special case of those two
canonical forms of perfect quantum channel. Furthermore, the orthogonal
complete measurement bases are given.


title:
Analytical Bethe Ansatz for closed and open gl(M|N) super-spin chains in
  arbitrary representations and for any Dynkin diagram

abstract:
  We present the analytical Bethe ansatz for spin chains based on the
superalgebras gl(M|N), $M\neq N$, with at each site an arbitrary representation
(and including inhomogeneities).
  The calculation is done for closed and open spin chains. In this latter case,
the boundary matrices $K_{\pm}(u)$ are of general type, provided they commute.
We compute the Bethe ansatz equations in full generality, and for any type of
Dynkin diagram. Examples are worked out to illustrate the techniques.


title:
The spatial distribution of substellar objects in IC348 and the Orion
  Trapezium Cluster

abstract:
  Aims: Some theoretical scenarios suggest the formation of brown dwarfs as
ejected stellar embryos in star-forming clusters. Such a formation mechanism
can result in different spatial distributions of stars and substellar objects.
We aim to investigate the spatial structure of stellar and substellar objects
in two well sampled and nearby embedded clusters, namely IC348 and the Orion
Trapezium Cluster (OTC) to test this hypothesis. Methods:Deep near-infrared
K-band data complete enough to sample the substellar population in IC348 and
OTC are obtained from the literature. The spatial distribution of the K-band
point sources is analysed using the Minimum Spanning Tree (MST) method. The Q
parameter and the spanning trees are evaluated for stellar and substellar
objects as a function of cluster core radius R$_c$. Results: The stellar
population in both IC348 and OTC display a clustered distribution whereas the
substellar population is distributed homogeneously in space within twice the
cluster core radius. Although the substellar objects do not appear to be bound
by the cluster potential well, they are still within the limits of the cluster
and not significantly displaced from their birth sites. Conclusions: The
spatially homogeneous distribution of substellar objects is best explained by
assuming higher initial velocities, distributed in a random manner and going
through multiple interactions. The overall spatial coincidence of these objects
with the cluster locations can be understood if these objects are nevertheless
travelling slowly enough so as to feel the gravitational effect of the cluster.
The observations support the formation of substellar objects as ``ejected
stellar embryos''. Higher ejection velocities are necessary but net spatial
displacements may not be necessary to explain the observational data.


title: Dirac Cat States in Relativistic Landau Levels

abstract:
  We show that a relativistic version of Schrodinger cat states, here called
Dirac cat states, can be built in relativistic Landau levels when an external
magnetic field couples to a relativistic spin 1/2 charged particle. Under
suitable initial conditions, the associated Dirac equation produces unitarily
Dirac cat states involving the orbital quanta of the particle in a well defined
mesoscopic regime. We demonstrate that the proposed Dirac cat states have a
purely relativistic origin and cease to exist in the non-relativistic limit. In
this manner, we expect to open relativistic quantum mechanics to the rich
structures of quantum optics and quantum information.


title: Coherent structures in localised and global pipe turbulence

abstract:
  The recent discovery of unstable travelling waves (TWs) in pipe flow has been
hailed as a significant breakthrough with the hope that they populate the
turbulent attractor. We confirm the existence of coherent states with internal
fast and slow streaks commensurate in both structure and energy with known TWs
using numerical simulations in a long pipe. These only occur, however, within
less energetic regions of (localized) `puff' turbulence at low Reynolds numbers
(Re=2000-2400), and not at all in (homogeneous) `slug' turbulence at Re=2800.
This strongly suggests that all currently known TWs sit in an intermediate
region of phase space between the laminar and turbulent states rather than
being embedded within the turbulent attractor itself. New coherent fast streak
states with strongly decelerated cores appear to populate the turbulent
attractor instead.


title:
A Model for Counterparty Risk with Geometric Attenuation Effect and the
  Valuation of CDS

abstract:
  In this paper, a geometric function is introduced to reflect the attenuation
speed of impact of one firm's default to its partner. If two firms are
competitions (copartners), the default intensity of one firm will decrease
(increase) abruptly when the other firm defaults. As time goes on, the impact
will decrease gradually until extinct. In this model, the joint distribution
and marginal distributions of default times are derived by employing the change
of measure, so can we value the fair swap premium of a CDS.


title:
X-ray flares on the UV Ceti-type star CC Eridani: a "peculiar"
  time-evolution of spectral parameters

abstract:
  Context: Weak flares are supposed to be an important heating agent of the
outer layers of stellar atmospheres. However, due to instrumental limitations,
only large X-ray flares have been studied in detail until now.
  Aims: We used an XMM-Newton observation of the very active BY-Dra type binary
star CC Eri in order to investigate the properties of two flares that are
weaker than those typically studied in the literature.
  Methods: We performed time-resolved spectroscopy of the data taken with the
EPIC-PN CCD camera. A multi-temperature model was used to fit the spectra. We
inferred the size of the flaring loops using the density-temperature diagram.
The loop scaling laws were applied for deriving physical parameters of the
flaring plasma. We also estimated the number of loops involved in the observed
flares.
  Results: A large X-ray variability was found. Spectral analysis showed that
all the regions in the light curve, including the flare segments, are
well-described by a 3-T model with variable emission measures but,
surprisingly, with constant temperatures (values of 3, 10 and 22 MK). The
analysed flares lasted ~ 3.4 and 7.1 ks, with flux increases of factors
1.5-1.9. They occurred in arcades made of a few tens of similar coronal loops.
The size of the flaring loops is much smaller than the distance between the
stellar surfaces in the binary system, and even smaller than the radius of each
of the stars. The obtained results are consistent with the following ideas: (i)
the whole X-ray light curve of CC Eri could be the result of a superposition of
multiple low-energy flares, and (ii) stellar flares can be scaled-up versions
of solar flares.


title: Computer-assisted access to the kidney

abstract:
  OBJECTIVES: The aim of this paper is to introduce the principles of
computer-assisted access to the kidney. The system provides the surgeon with a
pre-operative 3D planning on computed tomography (CT) images. After a rigid
registration with space-localized ultrasound (US) data, preoperative planning
can be transferred to the intra-operative conditions and an intuitive
man-machine interface allows the user to perform a puncture. MATERIAL AND
METHODS: Both CT and US images of informed normal volunteer were obtained to
perform calculation on the accuracy of registration and punctures were carried
out on a kidney phantom to measure the precision of the whole of the system.
RESULTS: We carried out millimetric registrations on real data and guidance
experiments on a kidney phantom showed encouraging results of 4.7 mm between
planned and reached targets. We noticed that the most significant error was
related to the needle deflection during the puncture. CONCLUSION: Preliminary
results are encouraging. Further work will be undertaken to improve efficiency
and accuracy, and to take breathing into account.


title: Radius and profile of random planar maps with faces of arbitrary degrees

abstract:
  We prove some asymptotic results for the radius and the profile of large
random rooted planar maps with faces of arbitrary degrees. Using a bijection
due to Bouttier, Di Francesco and Guitter between rooted planar maps and
certain four-type trees with positive labels, we derive our results from a
conditional limit theorem for four-type spatial Galton-Watson trees.


title:
Filtering and estimation in stochastic volatility models with rationally
  distributed disturbances

abstract:
  This paper deals with the filtering problem for a class of discrete time
stochastic volatility models in which the disturbances have rational
probability density functions. This includes the Cauchy distributions and
Student t-distributions with odd number of degrees of freedom. Using state
space realizations to represent the rational probability density functions we
are able to solve the filtering problem exactly. However the size of the
involved state space matrices grows exponentially with each time step of the
filter. Therefore we use stochastically balanced truncation techniques to
approximate the high order rational functions involved. In a simulation study
we show the applicability of this approach. In addition a simple method of
moments estimator is derived.


title: Corps de nombres peu ramifies et formes automorphes autoduales

abstract:
  Let S be a finite set of primes, p in S, and Q_S a maximal algebraic
extension of Q unramified outside S and infinity. Assume that |S|>=2. We show
that the natural maps Gal(Q_p^bar/Q_p) --> Gal(Q_S/Q) are injective. Much of
the paper is devoted to the problem of constructing selfdual automorphic
cuspidal representations of GL(2n,A_Q) with prescribed properties at all
places, that we study via the twisted trace formula of J. Arthur. The
techniques we develop shed also some lights on the orthogonal/symplectic
alternative for selfdual representations of GL(2n).


title:
Quasifinite representations of the Lie superalgebra of quantum pseudo
  differential operators

abstract:
  In this paper we extend general results obtained by V. Kac and J. Liberati,
in "Unitary quasifinite representations of $W_\infty$", (Letters Math. Phys.,
53 (2000), 11-27), for quasifinite highest weight representations of
$\Z$-graded Lie algebras to ${1/2}\Z$-graded Lie superalgebras, and we apply
these to classify the irreducible quasifinite highest weight modules of the Lie
superalgebra of quantum pseudo-differential operators.


title:
On the residual finiteness and other properties of (relative)
  one-relator groups

abstract:
  A relative one-relator presentation has the form P = < X,H ; R > where X is a
set, H is a group, and R is a group word on X and H. We show that if the group
word on X obtained from R by deleting all the terms from H has what we call the
unique max-min property, then the group defined by P is residually finite if
and only if H is residually finite (Theorem 1). We apply this to obtain new
results concerning the residual finiteness of (ordinary) one-relator groups
(Theorem 4). We also obtain results concerning the conjugacy problem for
one-relator groups (Theorem 5), and results concerning the relative asphericity
of presentations of the form P (Theorem 6).


title: Redshifted formaldehyde from the gravitational lens B0218+357

abstract:
  The gravitational lens toward B0218+357 offers the unique possibility to
study cool moderately dense gas with high sensitivity and angular resolution in
a cloud that existed half a Hubble time ago. Observations of the radio
continuum and six formaldehyde (H2CO) lines were carried out with the VLA, the
Plateau de Bure interferometer, and the Effelsberg 100-m telescope. Three radio
continuum maps indicate a flux density ratio between the two main images, A and
B, of ~ 3.4 +/- 0.2. Within the errors the ratio is the same at 8.6, 14.1, and
43 GHz. The 1_{01}-0_{00} line of para-H2CO is shown to absorb the continuum of
image A. Large Velocity Gradient radiative transfer calculations are performed
to reproduce the optical depths of the observed two cm-wave "K-doublet" and
four mm-wave rotational lines. These calculations also account for a likely
frequency-dependent continuum cloud coverage. Confirming the diffuse nature of
the cloud, an n(H2) density of < 1000 cm^{-3} is derived, with the best fit
suggesting n(H2) ~ 200 cm^{-3}. The H2CO column density of the main velocity
component is ~5 * 10^{13} cm^{-2}, to which about 7.5 * 10^{12} cm^{-2} has to
be added to also account for a weaker feature on the blue side, 13 km/s apart.
N(H2CO)/N(NH3) ~ 0.6, which is four times less than the average ratio obtained
from a small number of local diffuse (galactic) clouds seen in absorption. The
ortho-to-para H2CO abundance ratio is 2.0 - 3.0, which is consistent with the
kinetic temperature of the molecular gas associated with the lens of B0218+357.
With the gas kinetic temperature and density known, it is found that optically
thin transitions of CS, HCN, HNC, HCO+, and N2H+ (but not CO) will provide
excellent probes of the cosmic microwave background at redshift z=0.68.


title:
Visualization of ferromagnetic domains in TbNi$_2$B$_2$C and
  ErNi$_2$B$_2$C single crystals: Weak ferromagnetism and its coexistence with
  superconductivity

abstract:
  The magnetic flux structure in the basal plane, (001), of single crystals of
superconducting (R = Er) and non-superconducting (R = Tb) RNi$_2$B$_2$C was
studied by high resolution Bitter decoration at temperatures below $T_c$
(superconducting transition) and/or $T_N$ (antiferromagnetic transition). For
both materials two sets of domain boundaries, in \{110\} and \{100\} planes,
were observed. The temperature ranges in which the \{100\} domain boundaries
were observed in TbNi$_2$B$_2$C and ErNi$_2$B$_2$C coincide with the weak
ferromagnetic (WFM) ordering in these materials. On the other hand, the \{110\}
twin boundaries - the antiferromagnetic domain boundaries - were observed in
both compounds below $T_N$. The possibility of interpretation of \{100\}
boundaries as Bloch domain walls in the weakly ferromagnetic phase, for $T <
T_{WFM} < T_N$ (TbNi$_2$B$_2$C) or $T < T_{WFM} < T_N < T_c$ (ErNi$_2$B$_2$C)
is discussed.


title: A Sequent Calculus for Modelling Interferences

abstract:
  A logic calculus is presented that is a conservative extension of linear
logic. The motivation beneath this work concerns lazy evaluation, true
concurrency and interferences in proof search. The calculus includes two new
connectives to deal with multisequent structures and has the cut-elimination
property. Extensions are proposed that give first results concerning our
objectives.


title: The Forgotten Night: The Number Devil Explores Spherical Geometry

abstract:
  This is a missing chapter from Hans Magnus Enzensberger's mathematical
adventure The Number Devil (Henry Holt and Company, New York, 1997). In the
book, a math-hating boy named Robert is visited in his dreams by the clever
Number Devil, who teaches him to love all things numerical. However, we all
forget our dreams from time to time. Here is one adventure that Enzensberger
overlooked, where the Number Devil introduces Robert to geometry not-of-Euclid,
great circles, parallel transport, the pendulum of Foucault, and the genius of
Euler.


title: Flocking in noisy environments

abstract:
  We consider a perturbed version of the dynamics of a flock introduced by
Cucker and Smale ("Emergent behaviour in flocks") and prove, under similar
conditions, that nearly-alignment (a concept that is precised in the text) is
achieved with a certain probability, bounded from below.


title: SN 2001em: No Jet-Driven Gamma Ray Burst Event

abstract:
  We report on our second-epoch VLBI and VLA observations of the Type Ib/c
supernova 2001em, five years after the explosion. It was suggested that SN
2001em might be a jet-driven gamma ray burst (GRB), with the jet oriented near
the plane of the sky, which would entail relativistic expansion or motion. Our
VLBI image shows that SN 2001em is still unresolved five years after the
explosion. For a distance of 83 Mpc (H_0 = 70 km/s/Mpc), the nominal expansion
velocity is 5800 +/- 10,000 km/s, and the proper motion is 33,000 +/- 34,000
km/s. Our values are inconsistent with either relativistic expansion or motion,
but are consistent with the non-relativistic expansion speeds and small proper
motions seen in other supernovae. In particular these values are consistent
with radio emission from SN 2001em being due to normal, non-relativistic
supernova ejecta interacting with the circumstellar medium. Our VLA
observations show a power-law decay in flux density since the time of the peak
in the 8.4 GHz radio lightcurve in ~2003.


title: Orbital and Spin Excitations in Cobalt Oxide

abstract:
  By means of neutron scattering we have determined new branches of magnetic
excitations in orbitally active CoO (TN=290 K) up to 15 THz and for
temperatures from 6 K to 450 K. Data were taken in the (111) direction in six
single-crystal zones. From the dependence on temperature and Q we have
identified several branches of magnetic excitation. We describe a model for the
coupled orbital and spin states of Co2+ subject to a crystal field and
tetragonal distortion.


title:
Asteroseismology of red giants: photometric observations of Arcturus by
  SMEI

abstract:
  We present new results on oscillations of the K1.5 III giant Arcturus (alpha
Boo), from analysis of just over 2.5 yr of precise photometric observations
made by the Solar Mass Ejection Imager (SMEI) on board the Coriolis satellite.
A strong mode of oscillation is uncovered by the analysis, having frequency
3.51+/-0.03 micro-Hertz. By fitting its mode peak, we are able offer a highly
constrained direct estimate of the damping time (tau = 24+/-1 days). The data
also hint at the possible presence of several radial-mode overtones, and maybe
some non-radial modes. We are also able to measure the properties of the
granulation on the star, with the characteristic timescale for the granulation
estimated to be 0.50+/-0.05 days.


title: Cyclic projectors and separation theorems in idempotent convex geometry

abstract:
  Semimodules over idempotent semirings like the max-plus or tropical semiring
have much in common with convex cones. This analogy is particularly apparent in
the case of subsemimodules of the n-fold cartesian product of the max-plus
semiring it is known that one can separate a vector from a closed subsemimodule
that does not contain it. We establish here a more general separation theorem,
which applies to any finite collection of closed semimodules with a trivial
intersection. In order to prove this theorem, we investigate the spectral
properties of certain nonlinear operators called here idempotent cyclic
projectors. These are idempotent analogues of the cyclic nearest-point
projections known in convex analysis. The spectrum of idempotent cyclic
projectors is characterized in terms of a suitable extension of Hilbert's
projective metric. We deduce as a corollary of our main results the idempotent
analogue of Helly's theorem.


title:
Determining a regular language by glider-based structures called phases
  fi_1 in Rule 110

abstract:
  Rule 110 is a complex elementary cellular automaton able of supporting
universal computation and complicated collision-based reactions between
gliders. We propose a representation for coding initial conditions by means of
a finite subset of regular expressions. The sequences are extracted both from
de Bruijn diagrams and tiles specifying a set of phases fi_1 for each glider in
Rule 110. The subset of regular expressions is explained in detail.


title: High-resolution models of solar granulation: the 2D case

abstract:
  Using grid refinement, we have simulated solar granulation in 2D. The refined
region measures 1.97*2.58 Mm (vertical*horizontal). Grid spacing there is
1.82*2.84 km. The downflows exhibit strong Kelvin-Helmholtz instabilities.
Below the photosphere, acoustic pulses are generated. They proceed laterally
(in some cases distances of at least the size of our refined domain) and may be
enhanced when transversing downflows) as well as upwards where, in the
photosphere they contribute significantly to 'turbulence' (velocity gradients,
etc.) The acoustic pulses are ubiquitous in that at any time several of them
are seen in our high-resolution domain. Their possible contributions to p-mode
excitation or heating of the chromosphere needs to be investigated.


title:
Optimal Replica Placement in Tree Networks with QoS and Bandwidth
  Constraints and the Closest Allocation Policy

abstract:
  This paper deals with the replica placement problem on fully homogeneous tree
networks known as the Replica Placement optimization problem. The client
requests are known beforehand, while the number and location of the servers are
to be determined. We investigate the latter problem using the Closest access
policy when adding QoS and bandwidth constraints. We propose an optimal
algorithm in two passes using dynamic programming.


title: Random Boolean Networks

abstract:
  This review explains in a self-contained way the properties of random Boolean
networks and their attractors, with a special focus on critical networks. Using
small example networks, analytical calculations, phenomenological arguments,
and problems to solve, the basic concepts are introduced and important results
concerning phase diagrams, numbers of relevant nodes and attractor properties
are derived.


title: Probabilistic Representations of Solutions of the Forward Equations

abstract:
  In this paper we prove a stochastic representation for solutions of the
evolution equation $ \partial_t \psi_t = {1/2}L^*\psi_t $ where $ L^* $ is the
formal adjoint of an elliptic second order differential operator with smooth
coefficients corresponding to the infinitesimal generator of a finite
dimensional diffusion $ (X_t).$ Given $ \psi_0 = \psi $, a distribution with
compact support, this representation has the form $ \psi_t = E(Y_t(\psi))$
where the process $ (Y_t(\psi))$ is the solution of a stochastic partial
differential equation connected with the stochastic differential equation for $
(X_t) $ via Ito's formula.


title:
Microscopic origin of isotropic non-Heisenberg behavior in highly
  correlated systems

abstract:
  We have reanalyzed the microscopic origin of the isotropic deviations that
are observed from the energy spacings predicted by the HDVV Hamiltonian.
Usually, a biquadratic spin operator is added to the HDVV Hamiltonian to
account for such deviations. It is shown here that this operator cannot
describe the effect of the excited atomic non-Hund states which brought the
most important contribution to the deviations. For systems containing more than
two magnetic centers, non-Hund states cause additional interactions that are of
the same order of magnitude as the biquadratic exchange and should have
significant effects on the macroscopic properties of extended systems.


title:
Reliability of the Heitler-London approach for the exchange coupling
  between electrons in semiconductor nanostructures

abstract:
  We calculate the exchange coupling J between electrons in a double-well
potential in a two-dimensional semiconductor environment within the
Heitler-London (HL) approach. Two functional forms are considered for the
double-well potential. We show that by choosing an appropriate and relatively
simple single-electron variational wave function it is possible, within the HL
approach, to significantly improve the estimates for J. In all cases the
present scheme overcomes the artifacts and limitations at short interdot
distances, previously attributed to the HL method, where unphysical triplet
ground states have been found, and leads to an overall agreement with analytic
interpolated expressions for J obtained for a donor-type model potential.


title: Automorphisms of Generalized Down-Up Algebras

abstract:
  A generalization of down-up algebras was introduced by Cassidy and Shelton
(J. Algebra 279 (2004), no. 1), the so-called generalized down-up algebras. We
describe the automorphism group of conformal Noetherian generalized down-up
algebras L(f,r,s,\gamma) such that r is not a root of unity, listing explicitly
the elements of the group. In the last section we apply these results to
Noetherian down-up algebras, thus obtaining a characterization of the
automorphism group of Noetherian down-up algebras A(\alpha, \beta, \gamma) for
which the roots of the polynomial X^2-\alpha X-\beta are not both roots of
unity.


title: The Physics of Ultraperipheral Collisions at the LHC

abstract:
  We discuss the physics of large impact parameter interactions at the LHC:
ultraperipheral collisions (UPCs). The dominant processes in UPCs are
photon-nucleon (nucleus) interactions. The current LHC detector configurations
can explore small $x$ hard phenomena with nuclei and nucleons at photon-nucleon
center-of-mass energies above 1 TeV, extending the $x$ range of HERA by a
factor of ten. In particular, it will be possible to probe diffractive and
inclusive parton densities in nuclei using several processes. The interaction
of small dipoles with protons and nuclei can be investigated in elastic and
quasi-elastic $J/\psi$ and $\Upsilon$ production as well as in high $t$
$\rho^0$ production accompanied by a rapidity gap. Several of these phenomena
provide clean signatures of the onset of the new high gluon density QCD regime.
The LHC is in the kinematic range where nonlinear effects are several times
larger than at HERA. Two-photon processes in UPCs are also studied. In
addition, while UPCs play a role in limiting the maximum beam luminosity, they
can also be used a luminosity monitor by measuring mutual electromagnetic
dissociation of the beam nuclei. We also review similar studies at HERA and
RHIC as well as describe the potential use of the LHC detectors for UPC
measurements.


title: Primordial gas heating by dark matter and structure formation

abstract:
  Dark matter (DM) decays and annihilations might heat and partially reionize
the Universe at high redshift. Although this effect is not important for the
cosmic reionization, the gas heating due to DM particles might affect the
structure formation. In particular, the critical halo mass for collapse is
increased up to a factor of ~2. Also the fraction of gas which collapses inside
the smallest halos is substantially reduced with respect to the cosmological
value. These effects imply that DM decays and annihilations might delay the
formation of the first structures and reduce the total star mass in the
smallest halos.


title: KNO scaling in processes of electron-positron annihilation to hadrons

abstract:
  The charged particles multiplicity distribution in the KNO form is discussed
in processes of $e^+e^-$ annihilation at energies $\sqrt{s}$ 14 -- 206.2 GeV.
The experimental data are compared to data, obtained with Monte Carlo
simulation in PYTHIA in the Lund quark string model. It is shown, that both
experimental and simulated data are described by the same distribution function
in the KNO form. It is shown, that the KNO scaling is consequence of quark
string hadronization dynamics in the Lund string model.


title: Three-Dimensional Gravity Revisited

abstract:
  We consider the problem of identifying the CFT's that may be dual to pure
gravity in three dimensions with negative cosmological constant. The c-theorem
indicates that three-dimensional pure gravity is consistent only at certain
values of the coupling constant, and the relation to Chern-Simons gauge theory
hints that these may be the values at which the dual CFT can be holomorphically
factorized. If so, and one takes at face value the minimum mass of a BTZ black
hole, then the energy spectrum of three-dimensional gravity with negative
cosmological constant can be determined exactly. At the most negative possible
value of the cosmological constant, the dual CFT is very likely the monster
theory of Frenkel, Lepowsky, and Meurman. The monster theory may be the first
in a discrete series of CFT's that are dual to three-dimensional gravity. The
partition function of the second theory in the sequence can be determined on a
hyperelliptic Riemann surface of any genus. We also make a similar analysis of
supergravity.


title: Theory of ultracold Fermi gases

abstract:
  The physics of quantum degenerate Fermi gases in uniform as well as in
harmonically trapped configurations is reviewed from a theoretical perspective.
Emphasis is given to the effect of interactions which play a crucial role,
bringing the gas into a superfluid phase at low temperature. In these dilute
systems interactions are characterized by a single parameter, the s-wave
scattering length, whose value can be tuned using an external magnetic field
near a Feshbach resonance. The BCS limit of ordinary Fermi superfluidity, the
Bose-Einstein condensation (BEC) of dimers and the unitary limit of large
scattering length are important regimes exhibited by interacting Fermi gases.
In particular the BEC and the unitary regimes are characterized by a high value
of the superfluid critical temperature, of the order of the Fermi temperature.
Different physical properties are discussed, including the density profiles and
the energy of the ground-state configurations, the momentum distribution, the
fraction of condensed pairs, collective oscillations and pair breaking effects,
the expansion of the gas, the main thermodynamic properties, the behavior in
the presence of optical lattices and the signatures of superfluidity, such as
the existence of quantized vortices, the quenching of the moment of inertia and
the consequences of spin polarization. Various theoretical approaches are
considered, ranging from the mean-field description of the BCS-BEC crossover to
non-perturbative methods based on quantum Monte Carlo techniques. A major goal
of the review is to compare the theoretical predictions with the available
experimental results.


title: Polarized States and Domain Walls in Spinor Bose-Einstein Condensates

abstract:
  We study spin-polarized states and their stability in anti-ferromagnetic
states of spinor (F=1) quasi-one-dimensional Bose-Einstein condensates. Using
analytical approximations and numerical methods, we find various types of
polarized states, including: patterns of the Thomas-Fermi type; structures with
a pulse-shape in one component inducing a hole in the other components; states
with holes in all three components; and domain walls. A Bogoliubov-de Gennes
analysis reveals that families of these states contain intervals of a weak
oscillatory instability, except for the domain walls, which are always stable.
The development of the instabilities is examined by means of direct numerical
simulations.


title: Three experimental pearls in Costas arrays

abstract:
  The results of 3 experiments in Costas arrays are presented, for which
theoretical explanation is still not available: the number of dots on the main
diagonal of exponential Welch arrays, the parity populations of Golomb arrays
generated in fields of characteristic 2, and the maximal cross-correlation
between pairs of Welch or Golomb arrays generated in fields of size equal to a
Sophie Germain prime.


title:
The binary properties of the pulsating subdwarf B eclipsing binary PG
  1336-018 (NY Vir)

abstract:
  We present an unbiased orbit solution and mass determination of the
components of the eclipsing binary NY Vir as a critical test for the formation
scenarios of subdwarf B stars. We obtained high-resolution time series VLT/UVES
spectra and high-speed multicolour VLT/ULTRACAM photometric observations of NY
Vir, a rapidly pulsating subdwarf B star in a short period eclipsing binary.
Combining the radial velocity curve obtained from the VLT/UVES spectra with the
VLT/ULTRACAM multicolour lightcurves, we determined numerical orbital solutions
for this eclipsing binary. Due to the large number of free parameters and their
strong correlations, no unique solution could be found, only families of
solutions. We present three solutions of equal statistical significance, two of
which are compatible with the primary having gone through a core He-flash and a
common-envelope phase described by the $\alpha$-formalism. These two models
have an sdB primary of 0.466 \msol and 0.389 \msol, respectively. Finally, we
report the detection of the Rossiter-McLaughlin effect for NY Vir.


title: Unfolding Geometric Unification in M-Theory

abstract:
  By reinterpreting the familiar tools and ideas of M-theory model building, we
show how a G2-manifold locally engineered to give rise to massless matter
representations of an SU(5) grand unified model can be smoothly unfolded into a
G2-manifold giving rise to SU(3)xSU(2) gauge theory with the corresponding
matter representations. These ideas could lead to new insights in string
phenomenology because much of the arbitrariness of M-theory model building can
be removed by supposing, for example, that the singularities giving rise to
Standard Model particles could arise from unfolding a more singular, grand
unified geometry.


title: Coulomb shifts and shape changes in the mass 70 region

abstract:
  The technique of recoil beta tagging has been developed which allows prompt
gamma decays in nuclei from excited states to be correlated with electrons from
their subsequent short-lived beta decay. This technique is ideal for studying
nuclei very far from stability and improves in sensitivity for very short-lived
decays and for high decay Q-values. The method has allowed excited states in
78Y to be observed for the first time, as well as an extension in the knowledge
of T=1 states in 74Rb. From this new information it has been possible to
compare Coulomb energy differences (CED) between T=1 states in 70Br/70Se,
74Rb/74Kr, and 78Y/78Sr. The A=70 CED exhibit an anomalous behavior which is
inconsistent with all other known CED. This behavior may be accounted for
qualitatively in terms of small variations in the Coulomb energy arising from
shape changes.


title:
Extreme Associated Functions: Optimally Linking Local Extremes to
  Large-scale Atmospheric Circulation Structures

abstract:
  We present a new statistical method to optimally link local weather extremes
to large-scale atmospheric circulation structures. The method is illustrated
using July-August daily mean temperature at 2m height (T2m) time-series over
the Netherlands and 500 hPa geopotential height (Z500) time-series over the
Euroatlantic region of the ECMWF reanalysis dataset (ERA40). The method
identifies patterns in the Z500 time-series that optimally describe, in a
precise mathematical sense, the relationship with local warm extremes in the
Netherlands. Two patterns are identified; the most important one corresponds to
a blocking high pressure system leading to subsidence and calm, dry and sunny
conditions over the Netherlands. The second one corresponds to a rare, easterly
flow regime bringing warm, dry air into the region. The patterns are robust;
they are also identified in shorter subsamples of the total dataset. The method
is generally applicable and might prove useful in evaluating the performance of
climate models in simulating local weather extremes.


title:
Singularities of $n$-fold integrals of the Ising class and the theory of
  elliptic curves

abstract:
  We introduce some multiple integrals that are expected to have the same
singularities as the singularities of the $ n$-particle contributions
$\chi^{(n)}$ to the susceptibility of the square lattice Ising model. We find
the Fuchsian linear differential equation satisfied by these multiple integrals
for $ n=1, 2, 3, 4$ and only modulo some primes for $ n=5$ and $ 6$, thus
providing a large set of (possible) new singularities of the $\chi^{(n)}$. We
discuss the singularity structure for these multiple integrals by solving the
Landau conditions. We find that the singularities of the associated ODEs
identify (up to $n= 6$) with the leading pinch Landau singularities. The second
remarkable obtained feature is that the singularities of the ODEs associated
with the multiple integrals reduce to the singularities of the ODEs associated
with a {\em finite number of one dimensional integrals}. Among the
singularities found, we underline the fact that the quadratic polynomial
condition $ 1+3 w +4 w^2 = 0$, that occurs in the linear differential equation
of $ \chi^{(3)}$, actually corresponds to a remarkable property of selected
elliptic curves, namely the occurrence of complex multiplication. The
interpretation of complex multiplication for elliptic curves as complex fixed
points of the selected generators of the renormalization group, namely
isogenies of elliptic curves, is sketched. Most of the other singularities
occurring in our multiple integrals are not related to complex multiplication
situations, suggesting an interpretation in terms of (motivic) mathematical
structures beyond the theory of elliptic curves.

categories: math-ph cond-mat.stat-mech hep-th math.MP physics.comp-ph


title: The dust, planetesimals and planets of HD 38529

abstract:
  HD 38529 is a post-main sequence G8III/IV star (3.5 Gyr old) with a planetary
system consisting of at least two planets having Msin(i) of 0.8 MJup and 12.2
MJup, semimajor axes of 0.13 AU and 3.74 AU, and eccentricities of 0.25 and
0.35, respectively. Spitzer observations show that HD 38529 has an excess
emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at
70 micron of 4.7, a small excess at 33 micron (S/N=2.6) and no excess <30
micron. We discuss the distribution of the potential dust-producing
planetesimals from the study of the dynamical perturbations of the two known
planets, considering in particular the effect of secular resonances. We
identify three dynamically stable niches at 0.4-0.8 AU, 20-50 AU and beyond 60
AU. We model the spectral energy distribution of HD 38529 to find out which of
these niches show signs of harboring dust-producing plantesimals. The secular
analysis, together with the SED modeling resuls, suggest that the planetesimals
responsible for most of the dust emission are likely located within 20-50 AU, a
configuration that resembles that of the Jovian planets + Kuiper Belt in our
Solar System. Finally, we place upper limits (8E-6 lunar masses of 10 micron
particles) to the amount of dust that could be located in the dynamically
stable region that exists between the two planets (0.25--0.75 AU).


title: Equilibrium properties of mesoscopic quantum conductors

abstract: Review article on equilibrium properties of mesoscopic quantum conductors.


title:
The algebro-geometric initial value problem for the Ablowitz-Ladik
  hierarchy

abstract:
  We discuss the algebro-geometric initial value problem for the Ablowitz-Ladik
hierarchy with complex-valued initial data and prove unique solvability
globally in time for a set of initial (Dirichlet divisor) data of full measure.
To this effect we develop a new algorithm for constructing stationary
complex-valued algebro-geometric solutions of the Ablowitz-Ladik hierarchy,
which is of independent interest as it solves the inverse algebro-geometric
spectral problem for general (non-unitary) Ablowitz-Ladik Lax operators,
starting from a suitably chosen set of initial divisors of full measure.
Combined with an appropriate first-order system of differential equations with
respect to time (a substitute for the well-known Dubrovin-type equations), this
yields the construction of global algebro-geometric solutions of the
time-dependent Ablowitz-Ladik hierarchy.
  The treatment of general (non-unitary) Lax operators associated with general
coefficients for the Ablowitz-Ladik hierarchy poses a variety of difficulties
that, to the best of our knowledge, are successfully overcome here for the
first time. Our approach is not confined to the Ablowitz-Ladik hierarchy but
applies generally to (1+1)-dimensional completely integrable soliton equations
of differential-difference type.


title:
Muon Spin Spectroscopy evidence of the violation of Anderson condition
  in magnetite

abstract:
  We present new muon spectroscopy data on a Fe$_3$O$_4$ single crystal,
revealing different spin precession patterns in five distinct temperature
ranges. A careful analysis of the local field and its straightforward modeling
obtains surprisingly good agreement with experiments only if a very specific
model of localized charges violating Anderson condition, and a correlated muon
local dynamics are implemented. Muon evidence for fluctuations just above the
Verwey temperature, precursor of the low temperature charge localized state, is
provided.


title:
Reciprocity of Networks with Degree Correlations and Arbitrary Degree
  Sequences

abstract:
  Although most of the real networks contain a mixture of directed and
bidirectional (reciprocal) connections, the reciprocity $r$ has received little
attention as a subject of theoretical understanding. We study the expected
reciprocity of networks with an arbitrary degree sequence and a broad class of
degree correlations by means of statistical ensemble approach. We demonstrate
that degree correlations are crucial to understand the reciprocity in real
networks and a hierarchy of correlation contributions to $r$ is revealed.
Numerical experiments using novel network randomization methods show very good
agreement to our analytical estimations.


title:
First-order flow equations for extremal black holes in very special
  geometry

abstract:
  We construct interpolating solutions describing single-center static extremal
non-supersymmetric black holes in four-dimensional N=2 supergravity theories
with cubic prepotentials. To this end, we derive and solve first-order flow
equations for rotating electrically charged extremal black holes in a Taub-NUT
geometry in five dimensions. We then use the connection between five- and
four-dimensional extremal black holes to obtain four-dimensional flow equations
and we give the corresponding solutions.


title: Laser ablation loading of a surface-electrode ion trap

abstract:
  We demonstrate loading by laser ablation of $^{88}$Sr$^+$ ions into a
mm-scale surface-electrode ion trap. The laser used for ablation is a pulsed,
frequency-tripled Nd:YAG with pulse energies of 1-10 mJ and durations of 3-5
ns. An additional laser is not required to photoionize the ablated material.
The efficiency and lifetime of several candidate materials for the laser
ablation target are characterized by measuring the trapped ion fluorescence
signal for a number of consecutive loads. Additionally, laser ablation is used
to load traps with a trap depth (40 meV) below where electron impact ionization
loading is typically successful ($\gtrsim$ 500 meV).


title:
Eigenvalue Decomposition as a Generalized Synchronization Cluster
  Analysis

abstract:
  Motivated by the recent demonstration of its use as a tool for the detection
and characterization of phase-shape correlations in multivariate time series,
we show that eigenvalue decomposition can also be applied to a matrix of
indices of bivariate phase synchronization strength. The resulting method is
able to identify clusters of synchronized oscillators, and to quantify their
strength as well as the degree of involvement of an oscillator in a cluster.
Since for the case of a single cluster the method gives similar results as our
previous approach, it can be seen as a generalized Synchronization Cluster
Analysis, extending its field of application to more complex situations. The
performance of the method is tested by applying it to simulation data.


title: Quantum limited measurements of atomic scattering properties

abstract:
  We propose a method to perform precision measurements of the interaction
parameters in systems of N ultra-cold spin 1/2 atoms. The spectroscopy is
realized by first creating a coherent spin superposition of the two relevant
internal states of each atom and then letting the atoms evolve under a
squeezing Hamiltonian. The non-linear nature of the Hamiltonian decreases the
fundamental limit imposed by the Heisenberg uncertainty principle to N^(-2), a
factor of N smaller than the fundamental limit achievable with non-interacting
atoms. We study the effect of decoherence and show that even with decoherence,
entangled states can outperform the signal to noise limit of non-entangled
states. We present two possible experimental implementations of the method
using Bose-Einstein spinor condensates and fermionic atoms loaded in optical
lattices and discuss their advantages and disadvantages.


title: Domain Structures in Confined Nanoferroelectrics: Phase Field Approach

abstract:
  Phase field modeling of domain structures in ferroelectrics nanorods of
different shape and sizes is presented. The vortex domain configurations in
confined ferroelectrics have been explored by varying the ratio of the energies
of electrostatic and elastic interactions. It is shown that a strong effect of
the electrostatic interactions can cause the formation of 90o domain walls that
do not satisfy the condition of strain compatibility. A good agreement between
the results of phase field modeling and the results of atomistic calculations
for nano ferroelectrics demonstrates that the phase field approach provides an
effective tool for the analysis of domain structures in nano-ferroelectrics.


title: Many-body protected entanglement generation in interacting spin systems

abstract:
  We discuss a method to achieve decoherence resistent entanglement generation
in two level spin systems governed by gapped and multi-degenerate Hamiltonians.
In such systems, while the large number of degrees of freedom in the ground
state levels allows to create various quantum superpositions, the energy gap
prevents decoherence. We apply the protected evolution to achieve decoherence
resistent generation of many particle GHZ states and show it can significantly
increase the sensitivity in frequency spectroscopy. We discuss how to engineer
the desired many-body protected manifold in two specific physical systems,
trapped ions and neutral atoms in optical lattices, and present simple
expressions for the fidelity of GHZ generation under non-ideal conditions.


title: Self-Replicating Space-Cells and the Cosmological Constant

abstract:
  We consider what the implications would be if there were a discrete
fundamental model of physics based on locally-finite self-interacting
information, in which there is no presumption of the familiar space and laws of
physics, but from which such space and laws can nevertheless be shown to be
able to emerge stably from such a fundamental model. We argue that if there is
such a model, then the familiar laws of physics, including Standard Model
constants, etc., must be encodable by a finite quantity C, called the
complexity, of self-interacting information I, called a Space-Cell. Copies of
Space-Cell I must be distributed throughout space, at a roughly constant and
near-Planck density, and copies must be created or destroyed as space expands
or contracts. We then argue that each Space-Cell is a self-replicator that can
duplicate in times ranging from as fast as near-Planck-times to as slow as
Cosmological-Constant-time which is 10^{61} Planck-times. From standard
considerations of computation, we argue this slowest duplication rate just
requires that 10^{61} is less than about 2^C, the number of length-C binary
strings, hence requiring only the modest complexity C at least 203, and at most
a few thousand. We claim this provides a reasonable explanation for a
dimensionless constant being as large as 10^{61}, and hence for the
Cosmological Constant being a tiny positive 10^{-122}. We also discuss a
separate conjecture on entropy flow in Hole-Bang Transitions. We then present
Cosmological Natural Selection II.


title: Transition metal oxides using quantum Monte Carlo

abstract:
  The transition metal-oxygen bond appears prominently throughout chemistry and
solid-state physics. Many materials, from biomolecules to ferroelectrics to the
components of supernova remnants contain this bond in some form. Many of these
materials' properties strongly depend on fine details of the TM-O bond and
intricate correlation effects, which make accurate calculations of their
properties very challenging. We present quantum Monte Carlo, an explicitly
correlated class of methods, to improve the accuracy of electronic structure
calculations over more traditional methods like density functional theory. We
find that unlike s-p type bonding, the amount of hybridization of the d-p bond
in TM-O materials is strongly dependant on electronic correlation.


title: Integral degree of a ring and reduction numbers

abstract:
  The supremum of reduction numbers of ideals having principal reductions is
expressed in terms of the integral degree, a new invariant of the ring, which
is finite provided the ring has finite integral closure. As a consequence, one
obtains bounds for the Castelnuovo-Mumford regularity of the Rees algebra and
for the Artin-Rees numbers.


title:
DLCQ Strings, Twist Fields and One-Loop Correlators on a Permutation
  Orbifold

abstract:
  We investigate some aspects of the relationship between matrix string theory
and light-cone string field theory by analysing the correspondence between the
two-loop thermal partition function of DLCQ strings in flat space and the
integrated two-point correlator of twist fields in a symmetric product orbifold
conformal field theory at one-loop order. This is carried out by deriving
combinatorial expressions for generic twist field correlation functions in
permutation orbifolds using the covering surface method, by deriving the
one-loop modification of the twist field interaction vertex, and by relating
the two-loop finite temperature DLCQ string theory to the theory of Prym
varieties for genus two covers of an elliptic curve. The case of bosonic Z(2)
orbifolds is worked out explicitly and precise agreement between both
amplitudes is found. We use these techniques to derive explicit expressions for
Z(2) orbifold spin twist field correlation functions in the Type II and
heterotic string theories.


title:
Universal behavior of baryons and mesons' transverse momentum
  distributions in the framework of percolation of strings

abstract:
  In the framework of percolation of strings, we present predictions for the
$R_{AA}$ and $R_{CP}$ for mesons and baryons and for $\bar{p}/\pi^{0}$ ratios
at LHC energies.


title:
Form factors of branch-point twist fields in quantum integrable models
  and entanglement entropy

abstract:
  In this paper we compute the leading correction to the bipartite entanglement
entropy at large sub-system size, in integrable quantum field theories with
diagonal scattering matrices. We find a remarkably universal result, depending
only on the particle spectrum of the theory and not on the details of the
scattering matrix. We employ the "replica trick" whereby the entropy is
obtained as the derivative with respect to n of the trace of the n-th power of
the reduced density matrix of the sub-system, evaluated at n=1. The main
novelty of our work is the introduction of a particular type of twist fields in
quantum field theory that are naturally related to branch points in an
n-sheeted Riemann surface. Their two-point function directly gives the scaling
limit of the trace of the n-th power of the reduced density matrix. Taking
advantage of integrability, we use the expansion of this two-point function in
terms of form factors of the twist fields, in order to evaluate it at large
distances in the two-particle approximation. Although this is a well-known
technique, the new geometry of the problem implies a modification of the form
factor equations satisfied by standard local fields of integrable quantum field
theory. We derive the new form factor equations and provide solutions, which we
specialize both to the Ising and sinh-Gordon models.


title: Excitation energy dependence of symmetry energy of finite nuclei

abstract:
  A finite range density and momentum dependent effective interaction is used
to calculate the density and temperature dependence of the symmetry energy
coefficient Csym(rho,T) of infinite nuclear matter. This symmetry energy is
then used in the local density approximation to evaluate the excitation energy
dependence of the symmetry energy coefficient of finite nuclei in a
microcanonical formulation that accounts for thermal and expansion effects. The
results are in good harmony with the recently reported experimental data from
energetic nucleus-nucleus collisions.


title: XMM-Newton Observations of the Cataclysmic Variable GW Lib

abstract:
  XMM-Newton observations of the accreting, pulsating white dwarf in the
quiescent dwarf nova GW Librae were conducted to determine if the non-radial
pulsations present in previous UV and optical data affect the X-ray emission.
The non-radial pulsations are evident in the simultaneous Optical Monitor data
but are not detected in X-ray with an upper limit on the pulsation amplitude of
0.092 mags. The best fits to the X-ray spectrum are with a low temperature
diffuse gas model or a multi-temperature cooling flow model, with a strong
OVIII line, similar to other short period dwarf novae, but with a lower
temperature range than evident in normal short period dwarf novae. The lack of
pulsations and the spectrum likely indicate that the boundary layer does not
extend to the surface of the white dwarf.