title: Quantum Direct Communication with Continuous Variables

abstract:
  We show how continuous variable systems can allow the direct communication of
messages with an acceptable degree of privacy. This is possible by combining a
suitable phase-space encoding of the plain message with real-time checks of the
quantum communication channel. The resulting protocol works properly when a
small amount of noise affects the quantum channel. If this noise is
non-tolerable, the protocol stops leaving a limited amount of information to a
potential eavesdropper.


title:
Measurement of the production cross-sections of $\pi^\pm$ in p-C and
  $\pi^\pm$-C interactions at 12 GeV/c

abstract:
  The results of the measurements of the double-differential production
cross-sections of pions in p-C and $\pi^\pm$-C interactions using the forward
spectrometer of the HARP experiment are presented. The incident particles are
12 GeV/c protons and charged pions directed onto a carbon target with a
thickness of 5% of a nuclear interaction length. For p-C interactions the
analysis is performed using 100035 reconstructed secondary tracks, while the
corresponding numbers of tracks for $\pi^-$-C and $\pi^+$-C analyses are 106534
and 10122 respectively. Cross-section results are presented in the kinematic
range 0.5 GeV/c $\leq p_{\pi} <$ 8 GeV/c and 30 mrad $\leq \theta_{\pi} <$ 240
mrad in the laboratory frame. The measured cross-sections have a direct impact
on the precise calculation of atmospheric neutrino fluxes and on the improved
reliability of extensive air shower simulations by reducing the uncertainties
of hadronic interaction models in the low energy range.


title: Stochastic Gravity: Theory and Applications

abstract:
  Whereas semiclassical gravity is based on the semiclassical Einstein equation
with sources given by the expectation value of the stress-energy tensor of
quantum fields, stochastic semiclassical gravity is based on the
Einstein-Langevin equation, which has in addition sources due to the noise
kernel. In the first part, we describe the fundamentals of this new theory via
two approaches: the axiomatic and the functional. In the second part, we
describe three applications of stochastic gravity theory. First, we consider
metric perturbations in a Minkowski spacetime, compute the two-point
correlation functions of these perturbations and prove that Minkowski spacetime
is a stable solution of semiclassical gravity. Second, we discuss structure
formation from the stochastic gravity viewpoint. Third, we discuss the
backreaction of Hawking radiation in the gravitational background of a black
hole and describe the metric fluctuations near the event horizon of an
evaporating black hole


title:
Description of nuclear octupole and quadrupole deformation close to the
  axial symmetry: Critical-point behavior of 224Ra and 224Th

abstract:
  The model, introduced in a previous paper, for the description of the
octupole and quadrupole degrees of freedom in conditions close to the axial
symmetry, is applied to situations of shape phase transitions where the
quadrupole amplitude can reach zero. The transitional nuclei 224,226Ra and
224Th are discussed in the frame of this model. Their level schemes can be
reasonably accounted for assuming a square-well potential in two dimensions.
Electromagnetic transition amplitudes are also evaluated and compared with
existing experimental data.


title:
Zero-energy states of N = 4 SYM on T^3: S-duality and the mapping class
  group

abstract:
  We continue our studies of the low-energy spectrum of N=4 super-Yang-Mills
theory on a spatial three-torus. In two previous papers, we computed the
spectrum of normalizable zero-energy states for all choices of gauge group and
all values of the electric and magnetic 't Hooft fluxes, and checked its
invariance under the SL_2(Z) S-duality group. In this paper, we refine the
analysis by also decomposing the space of bound states into irreducible unitary
representations of the SL_3(Z) mapping class group of the three-torus. We
perform a detailed study of the S-dual pairs of theories with gauge groups
Spin(2n+1) and Sp(2n). The predictions of S-duality (which commutes with the
mapping class group) are fulfilled as expected, but the proof requires some
surprisingly intricate combinatorial infinite product identities.


title: Wrap groups of fiber bundles over quaternions and octonions

abstract:
  This article is devoted to the investigation of wrap groups of connected
fiber bundles over the fields of real $\bf R$, complex $\bf C$ numbers, the
quaternion skew field $\bf H$ and the octonion algebra $\bf O$. These groups
are constructed with mild conditions on fibers. Their examples are given. It is
shown, that these groups exist and for differentiable fibers have the infinite
dimensional Lie groups structure, that is, they are continuous or
differentiable manifolds and the composition $(f,g)\mapsto f^{-1}g$ is
continuous or differentiable depending on a class of smoothness of groups.
Moreover, it is demonstrated that in the cases of real, complex, quaternion and
octonion manifolds these groups have structures of real, complex, quaternion or
octonion manifolds respectively. Nevertheless, it is proved that these groups
does not necessarily satisfy the Campbell-Hausdorff formula even locally.


title: Polyakov loops and SU(2) staggered Dirac spectra

abstract:
  We consider the spectrum of the staggered Dirac operator with SU(2) gauge
fields. Our study is motivated by the fact that the antiunitary symmetries of
this operator are different from those of the SU(2) continuum Dirac operator.
In this contribution, we investigate in some detail staggered eigenvalue
spectra close to the free limit. Numerical experiments in the quenched
approximation and at very large $\beta$-values show that the eigenvalues occur
in clusters consisting of eight eigenvalues each. We can predict the locations
of these clusters for a given configuration very accurately by an analytical
formula involving Polyakov loops and boundary conditions. The spacing
distribution of the eigenvalues within the clusters agrees with the chiral
symplectic ensemble of random matrix theory, in agreement with theoretical
expectations, whereas the spacing distribution between the clusters tends
towards Poisson behavior.


title: Smooth Functors vs. Differential Forms

abstract:
  We establish a relation between smooth 2-functors defined on the path
2-groupoid of a smooth manifold and differential forms on this manifold. This
relation can be understood as a part of a dictionary between fundamental
notions from category theory and differential geometry. We show that smooth
2-functors appear in several fields, namely as connections on (non-abelian)
gerbes, as curvatures of smooth functors and as critical points in BF theory.
We demonstrate further that our dictionary provides a powerful tool to discuss
the transgression of geometric objects to loop spaces.


title: Nuclear expansion and symmetry energy of hot nuclei

abstract:
  The decrease in the symmetry energy of hot nuclei populated in $^{58}$Ni +
$^{58}$Ni, $^{58}$Fe + $^{58}$Ni and $^{58}$Fe + $^{58}$Fe reactions at beam
energies of 30, 40, and 47 MeV/nucleon, as a function of excitation energy is
studied. It is observed that this decrease is mainly a consequence of
increasing expansion or decreasing density rather than the increasing
temperature. The results are in good agreement with the recently reported
microscopic calculation based on the Thomas-Fermi approach. An empirical
relation to study the symmetry energy of finite nuclei in various mass region
is proposed.


title: Vogan Diagrams of Twisted Affine Kac-Moody Lie Algebras

abstract:
  A Vogan diagram is a Dynkin diagram of a Kac-Moody Lie algebra of finite or
affine type overlayed with additional structures. This paper develops the
theory of Vogan diagrams for almost compact real forms of indecomposable
twisted affine Kac- Moody Lie algebras and shows that equivalence classes of
Vogan diagrams correspond to isomorphism classes of almost compact real forms
of twisted affine Kac-Moody Lie algebras as given by H. Ben Messaoud and G.
Rousseau.


title:
Absence of line fields and Mane's theorem for non-recurrent
  transcendental functions

abstract:
  Let f be a transcendental meromorphic function. Suppose that the finite part
of the postsingular set of f is bounded, that f has no recurrent critical
points or wandering domains, and that the degree of pre-poles of f is uniformly
bounded. Then we show that f supports no invariant line fields on its Julia
set.
  We prove this by generalizing two results about rational functions to the
transcendental setting: a theorem of Mane about the branching of iterated
preimages of disks, and a theorem of McMullen regarding absence of invariant
line fields for "measurably transitive" functions. Both our theorems extend
results previously obtained by Graczyk, Kotus and Swiatek.


title:
Families of spatial solitons in a two-channel waveguide with the
  cubic-quintic nonlinearity

abstract:
  We present eight types of spatial optical solitons which are possible in a
model of a planar waveguide that includes a dual-channel trapping structure and
competing (cubic-quintic) nonlinearity. Among the families of trapped beams are
symmetric and antisymmetric solitons of "broad" and "narrow" types, composite
states, built as combinations of broad and narrow beams with identical or
opposite signs ("unipolar" and "bipolar" states, respectively), and
"single-sided" broad and narrow beams trapped, essentially, in a single
channel. The stability of the families is investigated via eigenvalues of small
perturbations, and is verified in direct simulations. Three species - narrow
symmetric, broad antisymmetric, and unipolar composite states - are unstable to
perturbations with real eigenvalues, while the other five families are stable.
The unstable states do not decay, but, instead, spontaneously transform
themselves into persistent breathers, which, in some cases, demonstrate
dynamical symmetry breaking and chaotic internal oscillations. A noteworthy
feature is a stability exchange between the broad and narrow antisymmetric
states: in the limit when the two channels merge into one, the former species
becomes stable, while the latter one loses its stability. Different branches of
the stationary states are linked by four bifurcations, which take different
forms in the model with the strong and weak inter-channel coupling.


title:
Sensitivity below the standard quantum limit in gravitational wave
  detectors with Michelson-Fabry-Perot readout

abstract:
  We calculate the quantum noise limited displacement sensitivity of a
Michelson-Fabry-Perot (MFP) with detuned cavities, followed by phase-sensitive
homodyne detection. We show that the standard quantum limit can be surpassed
even with resonant cavities and without any signal-recycling mirror nor
additional cavities. Indeed, thanks to the homodyne detection, the output field
quadrature can be chosen in such a way to cancel the effect of input amplitude
fluctuations, i.e., eliminating the force noise. With detuned cavities, the
modified opto-mechanical susceptivity allows to reach unlimited sensitivity for
large enough (yet finite) optical power. Our expressions include mirror losses
and cavity delay effect, for a realistic comparison with experiments. Our study
is particularly devoted to gravitational wave detectors and we consider both an
interferometer with free-falling mirrors, and a MFP as readout for a massive
detector. In the latter case, the sensitivity curve of the recently conceived
'DUAL' detector, based on two acoustic modes, is obtained.


title:
Deeply Virtual Compton Scattering on nucleons and nuclei in generalized
  vector meson dominance model

abstract:
  We consider Deeply Virtual Compton Scattering (DVCS) on nucleons and nuclei
in the framework of generalized vector meson dominance (GVMD) model. We
demonstrate that the GVMD model provides a good description of the HERA data on
the dependence of the proton DVCS cross section on Q^2, W (at Q^2=4 GeV^2) and
t. At Q^2 = 8 GeV^2, the soft W-behavior of the GVMD model somewhat
underestimates the W-dependence of the DVCS cross section due to the hard
contribution not present in the GVMD model. We estimate 1/Q^2 power-suppressed
corrections to the DVCS amplitude and the DVCS cross section and find them
large. We also make predictions for the nuclear DVCS amplitude and cross
section in the kinematics of the future Electron-Ion Collider. We predict
significant nuclear shadowing, which matches well predictions of the
leading-twist nuclear shadowing in DIS on nuclei.


title:
The gauge theory of dislocations: static solutions of screw and edge
  dislocations

abstract:
  We investigate the T(3)-gauge theory of static dislocations in continuous
solids. We use the most general linear constitutive relations bilinear in the
elastic distortion tensor and dislocation density tensor for the force and
pseudomoment stresses of an isotropic solid. The constitutive relations contain
six material parameters. In this theory both the force and pseudomoment
stresses are asymmetric. The theory possesses four characteristic lengths l1,
l2, l3 and l4 which are given explicitely. We first derive the
three-dimensional Green tensor of the master equation for the force stresses in
the translational gauge theory of dislocations. We then investigate the
situation of generalized plane strain (anti-plane strain and plane strain).
Using the stress function method, we find modified stress functions for screw
and edge dislocations. The solution of the screw dislocation is given in terms
of one independent length l1=l4. For the problem of an edge dislocation, only
two characteristic lengths l2 and l3 arise with one of them being the same
l2=l1 as for the screw dislocation. Thus, this theory possesses only two
independent lengths for generalized plane strain. If the two lengths l2 and l3
of an edge dislocation are equal, we obtain an edge dislocation which is the
gauge theoretical version of a modified Volterra edge dislocation. In the case
of symmetric stresses we recover well known results obtained earlier.


title: The Wyoming Survey for H-alpha. I. Initial Results at z ~ 0.16 and 0.24

abstract:
  The Wyoming Survey for H-alpha, or WySH, is a large-area, ground-based,
narrowband imaging survey for H-alpha-emitting galaxies over the latter half of
the age of the Universe. The survey spans several square degrees in a set of
fields of low Galactic cirrus emission. The observing program focuses on
multiple dz~0.02 epochs from z~0.16 to z~0.81 down to a uniform
(continuum+line) luminosity at each epoch of ~10^33 W uncorrected for
extinction (3sigma for a 3" diameter aperture). First results are presented
here for 98+208 galaxies observed over approximately 2 square degrees at
redshifts z~0.16 and 0.24, including preliminary luminosity functions at these
two epochs. These data clearly show an evolution with lookback time in the
volume-averaged cosmic star formation rate. Integrals of Schechter fits to the
extinction-corrected H-alpha luminosity functions indicate star formation rates
per co-moving volume of 0.009 and 0.014 h_70 M_sun/yr/Mpc^3 at z~0.16 and 0.24,
respectively. The formal uncertainties in the Schechter fits, based on this
initial subset of the survey, correspond to uncertainties in the cosmic star
formation rate density at the >~40% level; the tentative uncertainty due to
cosmic variance is 25%, estimated from separately carrying out the analysis on
data from the first two fields with substantial datasets.


title: The underlying complex network of the Minority Game

abstract:
  We study the structure of the underlying network of connections in the
Minority Game. There is not an explicit interaction among the agents, but they
interact via global magnitudes of the model and mainly through their
strategies. We define a link between two agents by quantifying the similarity
among their strategies, and analyze the structure of the resulting underlying
complex networks as a function of the number of agents in the game and the
value of the agents' memory, in games with two strategies per player. We
characterize the different phases of this system with networks with different
properties, for this link definition. Thus, the Minority Game phase
characterized by the presence of crowds can be identified with a small world
network, while the phase with the same results as a random decision game as a
random network. Finally, we use the Full Strategy Minority Game model, to
explicitly calculate some properties of its networks, such as the degree
distribution, for the same link definition, and to estimate, from them, the
properties of the networks of the Minority Game, obtaining a very good
agreement with its measured properties.


title: Fractional Cauchy problems on bounded domains

abstract:
  Fractional Cauchy problems replace the usual first-order time derivative by a
fractional derivative. This paper develops classical solutions and stochastic
analogues for fractional Cauchy problems in a bounded domain
$D\subset\mathbb{R}^d$ with Dirichlet boundary conditions. Stochastic solutions
are constructed via an inverse stable subordinator whose scaling index
corresponds to the order of the fractional time derivative. Dirichlet problems
corresponding to iterated Brownian motion in a bounded domain are then solved
by establishing a correspondence with the case of a half-derivative in time.


title: Extended Red Emission in High-Galactic Latitude Interstellar Clouds

abstract:
  Nearby interstellar clouds at high Galactic latitudes are ideal objects in
which the interaction of interstellar dust with photons from the
well-characterized interstellar radiation field can be studied. Scattering and
UV-excited photoluminescence at optical wavelengths as well as thermal emission
at mid- and far-infrared wavelengths are observable manifestations of such
interactions. Here we report initial results from an optical imaging survey of
optically thin high-Galactic-latitude clouds, which is designed to study the
surface brightness, structure, and spectral energy distribution of these
objects. The primary aim of this paper is to study the extended red emission
(ERE) that has been reported at high Galactic latitudes in earlier
investigations and which is attributed to ultraviolet-excited photoluminescence
of an as yet unidentified component of interstellar dust. We find strong
evidence for dust emission in the form of a broad (>1000 A FWHM) ERE band with
peak emission near 600 nm wavelength and peak intensity of ~ 5x10^-9 (erg cm^-2
s^-1 A^-1 sr^-1) in optically-thin clouds. This amounts to about 30% of the
total optical surface brightness of these clouds, the remainder being
consistent with expectations for dust-scattered light. This supports claims for
the ubiquitous presence of the ERE carrier throughout the diffuse interstellar
medium of the Milky Way Galaxy. We suggest that the ERE carrier is involved in
the radiative processing of about 20% to 30% of the dust-absorbed UV/optical
luminosity of the Milky Way galaxy, with the bulk of this energy being emitted
in the near- to mid-infrared spectral regions.


title:
Degeneracy of non-abelian quantum Hall states on the torus: domain walls
  and conformal field theory

abstract:
  We analyze the non-abelian Read-Rezayi quantum Hall states on the torus,
where it is natural to employ a mapping of the many-body problem onto a
one-dimensional lattice model. On the thin torus--the Tao-Thouless (TT)
limit--the interacting many-body problem is exactly solvable. The Read-Rezayi
states at filling $\nu=\frac k {kM+2}$ are known to be exact ground states of a
local repulsive $k+1$-body interaction, and in the TT limit this is manifested
in that all states in the ground state manifold have exactly $k$ particles on
any $kM+2$ consecutive sites. For $M\neq 0$ the two-body correlations of these
states also imply that there is no more than one particle on $M$ adjacent
sites. The fractionally charged quasiparticles and quasiholes appear as domain
walls between the ground states, and we show that the number of distinct domain
wall patterns gives rise to the nontrivial degeneracies, required by the
non-abelian statistics of these states. In the second part of the paper we
consider the quasihole degeneracies from a conformal field theory (CFT)
perspective, and show that the counting of the domain wall patterns maps one to
one on the CFT counting via the fusion rules. Moreover we extend the CFT
analysis to topologies of higher genus.


title: MS, S and C Stars in the Infrared. Luminosities and Mass Loss Rates

abstract:
  In this note I present an outline of infrared (IR) photometric AGB
properties, based on two samples of Galactic Long Period Variables (C- and
S-type respectively). I show the various selection criteria used during the
choice of the sources and describe the motivations of observing them at near-
and mid-IR wavelengths. I discuss the problems encountered in estimating their
luminosity and distance and motivate the methods I choose for this purpose.
Properties of the luminosity functions and of the Hertzsprung-Russell (HR)
diagrams obtained from the analysis are discussed. Finally, the choices made
for estimating of the mass loss rates are described and preliminary results
concerning them are shown.


title: General definitions of chaos for continuous and discrete-time processes

abstract:
  A precise definition of chaos for discrete processes based on iteration
already exists. We shall first reformulate it in a more general frame, taking
into account the fact that discrete chaotic behavior is neither necessarily
based on iteration nor strictly related to compact metric spaces or to bounded
functions. Then we shall apply the central idea of this definition to
continuous processes. We shall try to see what chaos is, regardless of the way
it is generated.


title:
An inhomogeneous model for the Galactic halo: a possible explanation for
  the spread observed in s- and r-process elements

abstract:
  We propose an explanation for the considerable scatter of the abundances of
neutron capture elements observed in low-metallicity stars in the solar
vicinity, compared to the small star-to-star scatter observed for the
alpha-elements. We have developed a stochastic chemical evolution model in
which the main assumption is a random formation of new stars subject to the
condition that the cumulative mass distribution follows a given initial mass
function. With our model, we are able to reproduce the different spreads of
neutron capture elements and alpha-elements in low-metallicity stars. The
reason for different observed spread in neutron capture elements and
alpha-elements resides in the random birth of stars, coupled with different
stellar mass ranges, from which alpha-elements and neutron capture elements
originate. In particular, the site of production of alpha-elements is the whole
range of massive stars, from 10 to 80 Msun whereas the mass range of production
for neutron capture elements lies between 12 and 30 Msun.


title: Boundary behavior of functions in the de Branges--Rovnyak spaces

abstract:
  This paper deals with the boundary behavior of functions in the de
Branges--Rovnyak spaces. First, we give a criterion for the existence of radial
limits for the derivatives of functions in the de Branges--Rovnyak spaces. This
criterion generalizes a result of Ahern-Clark. Then we prove that the
continuity of all functions in a de Branges--Rovnyak space on an open arc $I$
of the boundary is enough to ensure the analyticity of these functions on $I$.
We use this property in a question related to Bernstein's inequality.


title:
SUSY QM, symmetries and spectrum generating algebras for two-dimensional
  systems

abstract:
  We show in a systematic and clear way how factorization methods can be used
to construct the generators for hidden and dynamical symmetries. This is shown
by studying the 2D problems of hydrogen atom, the isotropic harmonic oscillator
and the radial potential $A\rho^{2\zeta-2}-B\rho^{\zeta-2}$. We show that in
these cases the non-compact (compact) algebra corresponds to so(2,1) (su(2)).


title: Numerical Correpondences between the physical Constants

abstract:
  We present here a note which synthesizes our previous ideas concerning some
problems in cosmology, and the numerical correspondences between the physical
constants that we could deduce.


title:
Liquid-vapor transition from a microscopic theory: Beyond the Maxwell
  construction

abstract:
  A smooth cut-off formulation of the Hierarchical Reference Theory (HRT) is
developed and applied to a Yukawa fluid. The HRT equations are derived and
numerically solved leading to: the expected renormalization group structure in
the critical region, non classical critical exponents and scaling laws, a
convex free energy in the whole phase diagram (including the two-phase region),
finite compressibility at coexistence, together with a fully satisfactory
comparison with available numerical simulations. This theory, which also
guarantees the correct short range behavior of two body correlations,
represents a major improvement over the existing liquid state theories.


title: Single-Photon Atomic Cooling

abstract:
  We report the cooling of an atomic ensemble with light, where each atom
scatters only a single photon on average. This is a general method that does
not require a cycling transition and can be applied to atoms or molecules which
are magnetically trapped. We discuss the application of this new approach to
the cooling of hydrogenic atoms for the purpose of precision spectroscopy and
fundamental tests.


title:
From Hadronic Parity Violation to Parity-Violating Electron Scattering
  and Tests of the Standard Model

abstract:
  After almost five decades of study of parity violation in hadronic systems,
the determination of the seven weak meson-nucleon couplings is still
incomplete. Whereas parity violation in nuclear systems is complicated by the
intricacies of QCD, measurements of parity violation in the much simpler
proton-proton system are more straightforward to interpret. We now have three
such precision pp experiments at 13.6, at 45, and 221 MeV. Today there are also
better possibilities for theoretical interpretation using effective field
theory. In electron-proton scattering, parity violating ep experiments such as
SAMPLE, G0, HAPPEX, and PVA4 have already shown that the strange quark
contributions to the charge and magnetization distributions of the nucleon are
tiny. When analyzed together, the results have also greatly improved knowledge
of the proton's "weak charge" (Q^p_weak = 1-4sin^2\theta_W at tree level). The
Q^p_weak experiment at JLab will further improve this, determining the proton's
weak charge to a precision of about 4%. Such a precision will either establish
conformity with the Standard Model of quarks and leptons or point to New
Physics. Following the upgrade of CEBAF at JLab to 12 GeV, a parity violating
electron-electron (Moller) scattering experiment similar to SLAC E158, will
measure the weak charge of the electron and hence sin^2\theta_W at low energy
with a precision comparable to the most precise individual measurements at the
Z0 pole (to about +/- 0.00025). This experiment will be complementary to
Q^p_weak in terms of sensitivity to New Physics.


title: Unsharp pointer observables and the structure of decoherence

abstract:
  The theory of decoherence attempts to explain the emergent classical
behaviour of a quantum system interacting with its quantum environment. In
order to formalize this mechanism we introduce the idea that the information
preserved in an open quantum evolution (or channel) can be characterized in
terms of observables of the initial system. We use this approach to show that
information which is broadcast into many parts of the environment can be
encoded in a single observable. This supports a model of decoherence where the
pointer observable can be an arbitrary positive operator-valued measure (POVM).
This generalization makes it possible to characterize the emergence of a
realistic classical phase-space. In addition, this model clarifies the
relationships among the information preserved in the system, the information
flowing from the system to the environment (measurement), and the establishment
of correlations between the system and the environment.


title:
Phototactic Clustering of Swimming Micro-organisms in a Turbulent
  Velocity Field

abstract:
  We study the distribution of swimming micro-organisms advected by a model
turbulent flow and attracted towards a localised light source through
phototaxis. It is shown that particles aggregate along a dynamical attractor
with fractal measure whose dimension depends on the strength of the phototaxis.
Using an effective diffusion approximation for the flow we derive an analytic
expression for the phototactic gain (increase in light exposure over the
aggregate) and by extension an accurate prediction for the fractal dimension
based on the properties of the advection dynamics and the statistics of the
attracting field. This shows that the fractal characteristics of the aggregate
are determined by the non-dimensional ratio of the kinetic energy of swimming
to that of the turbulent flow.


title:
Magnetic modelling and tomography: First steps towards a consistent
  reconstruction of the solar corona

abstract:
  We undertake a first attempt towards a consistent reconstruction of the
coronal magnetic field and the coronal density structure. We consider a
stationary solar corona which has to obey the equations of magnetohydrostatics.
We solve these equations with help of a newly developed optimization scheme. As
a first step we illustrate how tomographic information can be included into the
reconstruction of coronal magnetic fields. In a second step we use coronal
magnetic field information to improve the tomographic inversion process. As
input the scheme requires magnetic field measurements on the photosphere from
vector-magnetographs and the line-of-sight integrated density distribution from
coronagraphs. We test our codes with well known analytic magnetohydrostatic
equilibria and models. The program is planed for use within the STEREO mission.


title: Quantum cosmology with a minimal length

abstract:
  Quantum cosmology in the presence of a fundamental minimal length is analyzed
in the context of the flat isotropic and the Taub cosmological models. Such
minimal scale comes out from a generalized uncertainty principle and the
quantization is performed in the minisuperspace representation. Both the
quantum Universes are singularity-free and (i) in the isotropic model no
evidences for a Big-Bounce appear; (ii) in the Taub one a quasi-isotropic
configuration for the Universe is predicted by the model.


title:
Permutation asymmetry inducing entanglement between degrees of freedom
  in multiphoton states

abstract:
  We describe and examine entanglement between different degrees of freedom in
multiphoton states based on the permutation properties. From the state
description, the entanglement comes from the permutation asymmetry. According
to the different permutation properties, the multiphoton states can be divided
into several parts. It will help to deal with the multiphoton interference,
which can be used as the measurement of the entanglement.


title:
Exact solution of the six-vertex model with domain wall boundary
  condition. Critical line between ferroelectric and disordered phases

abstract:
  This is a continuation of the papers [4] of Bleher and Fokin and [5] of
Bleher and Liechty, in which the large $n$ asymptotics is obtained for the
partition function $Z_n$ of the six-vertex model with domain wall boundary
conditions in the disordered and ferroelectric phases, respectively. In the
present paper we obtain the large $n$ asymptotics of $Z_n$ on the critical line
between these two phases.


title: Homoscedastic controlled calibration model

abstract:
  In the context of the usual calibration model, we consider the case in which
the independent variable is unobservable, but a pre-fixed value on its
surrogate is available. Thus, considering controlled variables and assuming
that the measurement errors have equal variances we propose a new calibration
model. Likelihood based methodology is used to estimate the model parameters
and the Fisher information matrix is used to construct a confidence interval
for the unknown value of the regressor variable. A simulation study is carried
out to asses the effect of the measurement error on the estimation of the
parameter of interest. This new approach is illustrated with an example.


title: Prime path coalgebras

abstract:
  We use prime coalgebras as a generalization of simple coalgebras, and observe
that prime subcoalgebras represent the structure of the coalgebra in a more
efficient way than simple coalgebras. In particular, in this work we focus our
attention on the study and characterization of prime subcoalgebras of path
coalgebras of quivers and, by extension, of prime pointed coalgebras.


title: Black hole growth and stellar assembly at high-z

abstract:
  Context. Observations indicate a strong link between star formation and black
hole (BH) growth, but some questions remain unanswered: whether both activities
are coeval or whether one precedes the other, what their characteristic
timescales are, and what kinds of physical processes are responsible for this
interplay.
  Aims. We examine stellar and BH masses (M_star and M_BH) in z~2 active
systems at the peak of their AGN or star formation activity to investigate how
they are linked and whether AGN radiative or else radio power provides a
feedback mechanism that regulates the stellar growth in these systems.
  Methods. We analyze the infrared (IR) spectral energy distributions of radio,
sub-millimeter and mid-IR selected AGNs at z~1-3 and constrain their stellar
and AGN luminosities using AGN and host-galaxy templates.
  Results. We find evidence of increasing stellar light, thereby decreasing the
AGN mid-IR power going from mid-IR selected AGNs, to radio galaxies, and to
sub-millimeter AGNs. This trend can be explained by either decreasing Eddington
ratios or increasing offsets from the local M_BH-M_star relation. All systems
are characterized by high star formation rates regardless of their different
AGN powers, thus neither AGN radiative power nor AGN-driven radio activity
seems to influence the star formation rate in the selected AGNs. We discuss two
possible evolutionary scenarios that might link these three AGN classes.


title: Distributed Compression and Squashed Entanglement

abstract:
  A single quantum state can be shared by many distant parties. In this thesis,
we try to characterize the information contents of such distributed states by
defining the multiparty information and the multiparty squashed entanglement,
two steps toward a general theory of multiparty quantum information. As a
further step in that direction, we partially solve the multiparty distributed
compression problem where multiple parties use quantum communication to
faithfully transfer their shares of a state to a common receiver. We build a
protocol for multiparty distributed compression based on the fully quantum
Slepian-Wolf protocol and prove both inner and outer bounds on the achievable
rate region. We relate our findings to previous results in information theory
and discuss some possible applications.


title: Superpositions of Probability Distributions

abstract:
  Probability distributions which can be obtained from superpositions of
Gaussian distributions of different variances v = \sigma ^2 play a favored role
in quantum theory and financial markets. Such superpositions need not
necessarily obey the Chapman-Kolmogorov semigroup relation for Markovian
processes because they may introduce memory effects. We derive the general form
of the smearing distributions in v which do not destroy the semigroup property.
The smearing technique has two immediate applications. It permits simplifying
the system of Kramers-Moyal equations for smeared and unsmeared conditional
probabilities, and can be conveniently implemented in the path integral
calculus. In many cases, the superposition of path integrals can be evaluated
much easier than the initial path integral. Three simple examples are
presented, and it is shown how the technique is extended to quantum mechanics.

categories: cond-mat.other cond-mat.stat-mech math-ph math.MP quant-ph


title:
Nonlinear Transport Processes in Tokamak Plasmas. Part I: The
  Collisional Regimes

abstract:
  An application of the thermodynamic field theory (TFT) to transport processes
in L-mode tokamak plasmas is presented. The nonlinear corrections to the linear
(Onsager) transport coefficients in the collisional regimes are derived. A
quite encouraging result is the appearance of an asymmetry between the
Pfirsch-Schlueter (P-S) ion and electron transport coefficients: the latter
presents a nonlinear correction, which is absent for the ions, and makes the
radial electron coefficients much larger than the former. Explicit calculations
and comparisons between the neoclassical results and the TFT predictions for
JET plasmas are also reported. We found that the nonlinear electron P-S
transport coefficients exceed the values provided by neoclassical theory by a
factor, which may be of the order 100. The nonlinear classical coefficients
exceed the neoclassical ones by a factor, which may be of order 2. The
expressions of the ion transport coefficients, determined by the neoclassical
theory in these two regimes, remain unaltered. The low-collisional regimes
i.e., the plateau and the banana regimes, are analyzed in the second part of
this work.


title:
A new approach to solvability of some elliptic pde's with square
  integrable boundary data

abstract:
  This paper has been withdrawn, and is replaced with paper "Solvability of
elliptic systems with square integrable boundary data" by the same authors.


title: Andromeda XVII: A New Low Luminosity Satellite of M31

abstract:
  We report the discovery of a new dwarf spheroidal galaxy near M31 based on
INT/WFC imaging. The system, Andromeda XVII (And XVII), is located at a
projected radius of ~44 kpc from M31 and has a line-of-sight distance of
794+/-40 kpc measured using the tip of the red giant branch, and therefore lies
well within the halo of M31. The colour of the red giant branch implies a
metallicity of [Fe/H]~-1.9 and we find an absolute magnitude of M_v~ -8.5.
Three globular clusters lie near the main body of And XVII, suggesting a
possible association; if any of these are confirmed, it would make And XVII
exceptionally unusual amongst the faint dSph population. The projected position
on the sky of And XVII strengthens an intriguing alignment apparent in the
satellite system of M31, although with a caveat about biases stemming from the
current area surveyed to significant depth.


title:
Continuous time random walk for open systems: Fluctuation theorems and
  counting statistics

abstract:
  We consider continuous time random walks (CTRW) for open systems that
exchange energy and matter with multiple reservoirs. Each waiting time
distribution (WTD) for times between steps is characterized by a positive
parameter a, which is set to a=1 if it decays at least as fast as t^{-2} at
long times and therefore has a finite first moment. A WTD with a<1 decays as
t^{-a-1}. A fluctuation theorem for the trajectory quantity R, defined as the
logarithm of the ratio of the probability of a trajectory and the probability
of the time reversed trajectory, holds for any CTRW. However, R can be
identified as a trajectory entropy change only if the WTDs have a=1 and satisfy
separability (also called "direction time independence"). For nonseparable WTDs
with a=1, R can only be identified as a trajectory entropy change at long
times, and a fluctuation theorem for the entropy change then only holds at long
times. For WTDs with 0<a<1 no meaningful fluctuation theorem can be derived. We
also show that the (experimentally accessible) n'th moments of the energy and
matter transfers between the system and a given reservoir grow as t^{n a} at
long times.


title: Characteristics of Bose-Einstein condensation in an optical lattice

abstract:
  We discuss several possible experimental signatures of the Bose-Einstein
condensation (BEC) transition for an ultracold Bose gas in an inhomogeneous
optical lattice. Based on the commonly used time-of-flight imaging technique,
we show that the momentum-space density profile in the first Brillouin zone,
supplemented by the visibility of interference patterns, provides valuable
information about the system. In particular, by crossing the BEC transition
temperature, the appearance of a clear bimodal structure sets a qualitative and
universal signature of this phase transition. Furthermore, the momentum
distribution can also be applied to extract the condensate fraction, which may
serve as a promising thermometer in such a system.


title: Acoustic cloaking in 2D and 3D using finite mass

abstract:
  Fundamental features of rotationally symmetric acoustic cloaks with
anisotropic inertia are derived. Two universal relations are found to connect
the radial and transverse phase speeds and the bulk modulus in the cloak.
Perfect cloaking occurs only if the radial component of the density becomes
infinite at the cloak inner boundary, requiring an infinitely massive cloak. A
practical cloak of finite mass is defined in terms of its effective visible
radius, which vanishes for perfect cloaking. Significant cloaking is obtained
when the effective visible radius is subwavelength, reducing the total
scattering cross section, and may be achieved even as the interior radius of
the cloak is large relative to the wavelength. Both 2D vs. 3D effects are
compared as we illustrate how the spatial dependence of the cloaking parameters
effect the total cross section.


title: Strategies for Determining the Nature of Dark Matter

abstract:
  In this review, we discuss the role of the various experimental programs
taking part in the broader effort to identify the particle nature of dark
matter. In particular, we focus on electroweak scale dark matter particles and
discuss a wide range of search strategies being carried out and developed to
detect them. These efforts include direct detection experiments, which attempt
to observe the elastic scattering of dark matter particles with nuclei,
indirect detection experiments, which search for photons, antimatter and
neutrinos produced as a result of dark matter annihilations, and collider
searches for new TeV-scale physics. Each of these techniques could potentially
provide a different and complementary set of information related to the mass,
interactions and distribution of dark matter. Ultimately, it is hoped that
these many different tools will be used together to conclusively identify the
particle or particles that constitute the dark matter of our universe.


title:
From star clusters to dwarf galaxies: The properties of dynamically hot
  stellar systems

abstract:
  (Abridged) Objects with radii of 10 to 100 pc and masses in the range from
10^6 to 10^8 M_sun have been discovered during the past decade. These so-called
ultra compact dwarf galaxies (UCDs) constitute a transition between classical
star clusters and elliptical galaxies in terms of radii, relaxation times and
V-band mass-to-light (M/L_V) ratios. Using new data, we find that the mass
interval from 10^6 to 10^7 M_sun is of special interest, because within this
range typical half-light radii and dynamical mass-to-light ratios begin to
increase compared to globular clusters, the highest stellar densities are
reached and typical median two-body relaxation times surpass a Hubble time. The
M/L_V ratios of the UCDs turn out to be incompatible with the predictions from
simple stellar population (SSP) models when using the canonical stellar initial
mass function (IMF), although SSPs probably are good approximations to the real
stellar populations in UCDs and the SSP models allow to account for metallicity
effects on the M/L_V ratio. This provides evidence for the UCDs either having
formed with an IMF different from the canonical one or containing dark matter.
We emphasise that almost all pressure-supported stellar systems ranging from
star clusters to massive elliptical galaxies have M/L_V ratios less than 10
M_sun/L_sun, and that only dSph satellite galaxies have M/L_V ratios greater
than 100 M_sun/L_sun and therewith form exceptional systems.


title:
Conductance of d-wave superconductor/normal metal/d-wave superconductor
  junctions

abstract:
  We develop a theory of the conductance of superconductor/normal
metal/superconductor junctions in the case where the superconducting order
parameter has d-wave symmetry. At low temperature the conductance is
proportional to the square root of the inelastic electron relaxation time in
the bulk of the superconductor. As a result it turns out to be much larger than
the conductance of the normal part of the junction.


title: Gonality, apolarity and hypercubics

abstract:
  We show that any Fermat hypercubic is apolar to a trigonal curve, and vice
versa. We show also that the Waring number of the polar hypercubic associated
to a tetragonal curve of genus $g$ is at most $\lceil 3/2g - 7/2\rceil$, and
for a large class of them is at most $4/3g - 3$.


title: Energy conditions bounds and their confrontation with supernovae data

abstract:
  The energy conditions play an important role in the understanding of several
properties of the Universe, including the current accelerating expansion phase
and the possible existence of the so-called phantom fields. We show that the
integrated bounds provided by the energy conditions on cosmological observables
such as the distance modulus $\mu(z)$ and the lookback time $t_L(z)$ are not
sufficient (nor necessary) to ensure the local fulfillment of the energy
conditions, making explicit the limitation of these bounds in the confrontation
with observational data. We recast the energy conditions as bounds on the
deceleration and normalized Hubble parameters, obtaining new bounds which are
necessary and sufficient for the local fulfillment of the energy conditions. A
statistical confrontation, with $1\sigma-3\sigma$ confidence levels, between
our bounds and supernovae data from the gold and combined samples is made for
the recent past. Our analyses indicate, with $3\sigma$ confidence levels, the
fulfillment of both the weak energy condition (WEC) and dominant energy
condition (DEC) for $z \leq 1$ and $z \lesssim 0.8$, respectively. In addition,
they suggest a possible recent violation of the null energy condition (NEC)
with $3\sigma$, i.e. a very recent phase of super-acceleration. Our analyses
also show the possibility of violation of the strong energy condition
(\textbf{SEC}) with $3\sigma$ in the recent past ($z \leq 1$), but
interestingly the $q(z)$-best-fit curve crosses the SEC-fulfillment divider at
$z \simeq 0.67$, which is a value very close to the beginning of the epoch of
cosmic acceleration predicted by the standard concordance flat $\Lambda$CDM
scenario.


title:
The Structure of Protoplanetary Disks Surrounding Three Young
  Intermediate Mass Stars. I. Resolving the disk rotation in the [OI] 6300 \AA
  line

abstract:
  We present high spectral resolution optical spectra of three young
intermediate mass stars, in all of which we spectrally resolve the 6300
Angstrom [OI] emission line. Two of these have a double peaked line profile. We
fit these data with a simple model of the [OI] emission caused by
photo-dissociation of OH molecules in the upper layer of a circumstellar disk
by stellar UV radiation and thus translate the Doppler broadened [OI] emission
profile into an amount of emission as a function of distance from the central
star. The resulting spectra are in agreement with the expected disk shapes as
derived from their spectral energy distribution. We find evidence for shadowing
by an inner rim in the disk surrounding HD101412 and see a flaring disk
structure in HD179218 while the [OI] spectrum of HD135344 is more complex. The
[OI] emission starts for all three targets at velocities corresponding to their
dust sublimation radius and extends up to radii of 10 -- 90 AU. This shows that
this method can be a valuable tool in the future investigation of circumstellar
disks.


title:
CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor
  and Regional Variations

abstract:
  We use the COMPLETE data to derive new calibrations of the X-factor and the
13CO abundance within Perseus. We divide Perseus into six sub-regions. The
standard X factor, X=N(H2)/W(12CO), is derived both for the whole Perseus
Complex and for each of the six sub-regions with values consistent with
previous estimates. The X factor is heavily affected by the saturation of the
emission above AV~4 mag, and variations are found between regions. We derive
linear fits to relate W(12CO) and AV using only points below 4 mag of
extinction, this yields a better estimation of the AV than the X-factor. We
derive linear relations of W(13CO), N(13CO) and W(C18O) with AV . The
extinction threshold above which 13CO(1-0) and C18O(1-0) are detected is about
1 mag larger than previous estimates. 12CO(1-0) and 13CO(1-0) lines saturate
above 4 and 5 mag, respectively, whereas C18O(1-0) never saturates (up to 10
mag). Approximately 60% of the positions with 12CO emission have sub-thermally
excited lines, and almost all positions have 12CO excitation temperatures below
the dust temperature. Using the Meudon PDR code we find that 12CO and 13CO
emission can be explained by uniform slab models with densities ranging between
about 10^3 and 10^4 cm-3. Local variations in the volume density and
non-thermal motions (linked to different star formation activity) can explain
the observations. Higher densities are needed to reproduce CO data toward
active star forming sites, where the larger internal motions driven by the
young protostars allow more photons from the embedded high density cores to
escape the cloud. In the most quiescent region, the 12CO and 13CO emission
appears to arise from an almost uniform thin layer of molecular material at
densities around 10^4 cm-3.


title: Residual finiteness, QCERF, and fillings of hyperbolic groups

abstract:
  We prove that if every hyperbolic group is residually finite, then every
quasi-convex subgroup of every hyperbolic group is separable. The main tool is
relatively hyperbolic Dehn filling.


title: Quantum mass correction for the twisted kink

abstract:
  We present an analytic result for the 1-loop quantum mass correction in
semiclassical quantization for the twisted \phi^4 kink on S^1 without explicit
knowledge of the fluctuation spectrum. For this purpose we use the contour
integral representation of the spectral zeta function. By solving the Bethe
ansatz equations for the n=2 Lame equation we obtain an analytic expression for
the corresponding spectral discriminant. We discuss the renormalization issues
of this model. An energetically preferred size for the compact space is finally
obtained.


title: Cosmic Sparks from Superconducting Strings

abstract:
  We investigate cosmic sparks from cusps on superconducting cosmic strings in
light of the recently discovered millisecond radio burst by Lorimer et al [1].
We find that the observed duration, fluence, spectrum, and event rate can be
reasonably explained by Grand Unification scale superconducting cosmic strings
that carry currents \sim 10^5 GeV. The superconducting string model predicts an
event rate that falls off only as S^{-1/2}, where S is the energy flux, and
hence predicts a population of very bright bursts. Other surveys, with
different observational parameters, are shown to impose tight constraints on
the superconducting string model.


title:
A new solution representation for the BBM equation in a quarter plane
  and the eventual periodicity

abstract:
  The initial- and boundary-value problem for the Benjamin-Bona-Mahony (BBM)
equation is studied in this paper. The goal is to understand the periodic
behavior (termed as eventual periodicity) of its solutions corresponding to
periodic boundary condition or periodic forcing. To this aim, we derive a new
formula representing solutions of this initial- and boundary-value problem by
inverting the operator $\partial_t +\alpha \partial_x -\gamma\partial_{xxt}$
defined in the space-time quarter plane. The eventual periodicity of the
linearized BBM equation with periodic boundary data and forcing term is
established by combining this new representation formula and the method of
stationary phase.


title: Spin-valve effect and magnetoresistivity in single crystalline Ca3Ru2O7

abstract:
  The laminar perovskite Ca3Ru2O7 naturally forms ferromagnetic double-layers
of alternating moment directions, as in the spin-valve superlattices. The
mechanism of huge magnetoresistive effect in the material has been
controversial due to a lack of clear understanding of various magnetic phases
and phase-transitions. In this neutron diffraction study in a magnetic field,
we identify four different magnetic phases in Ca3Ru2O7 and determine all
first-order and second-order phase transitions between them. The spin-valve
mechanism then readily explains the dominant magnetoresistive effect in
Ca3Ru2O7.


title:
Upper bounds on signals due to WIMP self--annihilation: comments on the
  case of the synchrotron radiation from the galactic center and the WMAP haze

abstract:
  Two recent papers reconsider the possibility that the excess of microwave
emission from a region within $\sim 20^0$ of the galactic center (the {\it WMAP
haze}), measured by WMAP, can be due to the synchrotron emission originated by
neutralino self-annihilation; on the basis of this possible occurrence, also
upper bounds on the neutralino self-annihilation cross--section are suggested.
In the present note, we show that in the common case of thermal WIMPs in a
standard cosmological model, when the rescaling of the galactic WIMP density is
duly taken into account for subdominant WIMPs, the upper bound applicable
generically to {\it any} signal due to self-conjugate WIMPs is more stringent
than the ones obtained from analysis of the WMAP haze. We also argue that an
experimental upper bound, which can compete with our generic upper limit, can
rather be derived from measurements of cosmic antiproton fluxes, for some
values of the parameters of the astrophysical propagation model. Finally, we
comment on the possible impact of our generic upper bound on the interpretation
of the WMAP haze in terms of thermal neutralinos in a standard cosmological
scheme.


title: Spin Effects in Long Range Electromagnetic Scattering

abstract:
  We analyze the electromagnetic scattering of massive particles with and
without spin and, using the techniques of effective field theory, we isolate
the leading long distance effects beyond one photon exchange, both classical
and quantum mechanical. Spin-independent and spin-dependent effects are
isolated and shown to have a universal structure.


title: Spin Effects in Long Range Gravitational Scattering

abstract:
  We study the gravitational scattering of massive particles with and without
spin in the effective theory of gravity at one loop level. Our focus is on long
distance effects arising from nonanalytic components of the scattering
amplitude and we show that the spin-independent and the spin-dependent long
range components exhibit a universal form. Both classical and quantum
corrections are obtained, and the definition of a proper second order potential
is discussed.


title: Long Distance Effects in Mixed Electromagnetic-Gravitational Scattering

abstract:
  Using the methods of effective field theory we examine long range effects in
mixed electromagnetic-gravitational scattering. Recent calculations which have
yielded differing results for such effects are examined and corrected. We
consider various spin configurations of the scattered particles and find that
universality with respect to spin-dependence is obtained in agreement with
expectations.


title:
MOST Spacebased Photometry of the Transiting Exoplanet System HD 209458:
  Transit Timing to Search for Additional Planets

abstract:
  We report on the measurement of transit times for the HD 209458 planetary
system from photometry obtained with the MOST (Microvariability & Oscillations
of STars) space telescope. Deviations from a constant orbital period can
indicate the presence of additional planets in the system that are yet
undetected, potentially with masses approaching an Earth mass. The MOST data
sets of HD 209458 from 2004 and 2005 represent unprecedented time coverage with
nearly continuous observations spanning 14 and 43 days and monitoring 3
transits and 12 consecutive transits, respectively. The transit times we obtain
show no variations on three scales: (a) no long-term change in P since before
2004 at the 25 ms level, (b) no trend in transit timings during the 2005 run,
and (c) no individual transit timing deviations above 80 sec level. Together
with previously published transit times from Agol & Steffen (2007), this allows
us to place limits on the presence of additional close-in planets in the
system, in some cases down to below an Earth mass. This result, along with
previous radial velocity work, now eliminates the possibility that a perturbing
planet could be responsible for the additional heat source needed to explain HD
209458b's anomalous low density.


title: A String Field Theory based on Causal Dynamical Triangulations

abstract:
  We formulate the string field theory in zero-dimensional target space
corresponding to the two-dimensional quantum gravity theory defined through
Causal Dynamical Triangulations. This third quantization of the quantum gravity
theory allows us in principle to calculate the transition amplitudes of
processes in which the topology of space changes in time, and to include
non-trivial topologies of space-time. We formulate the corresponding
Dyson-Schwinger equations and illustrate how they can be solved iteratively.


title:
Spin(1)Spin(2) Effects in the Motion of Inspiralling Compact Binaries at
  Third Order in the Post-Newtonian Expansion

abstract:
  We use effective field theory techniques to compute the potentials due to
spin-spin and spin-orbit effects, from which the spin(1)spin(2) contribution to
the motion of spinning compact binaries to third Post-Newtonian (PN) order
follow. We use a formalism which allows us to impose the spin supplementarity
condition (SSC) in a canonical framework to all orders in the PN expansion. We
explicitly show the equivalence with our previous results, obtained using the
Newton-Wigner SSC at the level of the action for spin-spin and spin-orbit
potentials reported in arXiv:gr-qc/0604099 and arXiv:0712.2032[gr-qc]
respectively.


title:
Phonon softening and "forbidden" mode observed by Raman scattering in
  Na0.5CoO2

abstract:
  Polarized Raman scattering measurements have been performed on Na0.5CoO2
single crystal from 8 to 305 K. Both the A1g and E1g phonon modes show a
softening below Tc1 ~ 83 K. Additionally, the A1g phonon mode, which is
forbidden in the scattering geometry of cross polarization for the triangular
CoO2 layers, appears below Tc1. In contrast, the metal-insulator transition at
Tc2 ~ 46 K has only secondary effect on the Raman spectra. The phonon softening
and the ``forbidden'' Raman intensity follow closely magnetic order parameter
and the gap function at the Fermi surface, indicating that the distortion of
CoO6 octahedra at Tc1, instead of the Na ordering at ~350 K, is the relevant
structural component of the 83 K phase transition.


title:
Relative Asymptotic of Multiple Orthogonal Polynomials for Nikishin
  Systems

abstract:
  We prove relative asymptotic for the ratio of two sequences of multiple
orthogonal polynomials with respect to Nikishin system of measures. The first
Nikishin system ${\mathcal{N}}(\sigma_1,...,\sigma_m)$ is such that for each
$k$, $\sigma_k$ has constant sign on its compact support $\supp {\sigma_k}
\subset \mathbb{R}$ consisting of an interval $\widetilde{\Delta}_k$, on which
$|\sigma_k^{\prime}| > 0$ almost everywhere, and a discrete set without
accumulation points in $\mathbb{R} \setminus \widetilde{\Delta}_k$. If
${Co}(\supp {\sigma_k}) = \Delta_k$ denotes the smallest interval containing
$\supp {\sigma_k}$, we assume that $\Delta_k \cap \Delta_{k+1} = \emptyset$,
$k=1,...,m-1$. The second Nikishin system
${\mathcal{N}}(r_1\sigma_1,...,r_m\sigma_m)$ is a perturbation of the first by
means of rational functions $r_k$, $k=1,...,m,$ whose zeros and poles lie in
$\mathbb{C} \setminus \cup_{k=1}^m \Delta_k$.


title: Local geometry of the G2 moduli space

abstract:
  We consider deformations of torsion-free G2 structures, defined by the
G2-invariant 3-form $\phi$ and compute the expansion of the Hodge star of
$\phi$ to fourth order in the deformations of $\phi$. By considering M-theory
compactified on a G2 manifold, the G2 moduli space is naturally complexified,
and we get a Kahler metric on it. Using the expansion of the Hodge star of
$\phi$ we work out the full curvature of this metric and relate it to the
Yukawa coupling.


title:
New Developments in Precision LHC Theory: QEDXQCD Exponentiation,
  Shower/ME Matching, IR-Improved DGLAP-CS Theory and Implications for UV
  Finite Quantum Gravity

abstract:
  We present the recent developments in exact amplitude-based resummation
methods for non-Abelian gauge theories as they relate to precision LHC physics.
We discuss QEDXQCD exponentiation, shower/ME matching, IR-improved DGLAP-CS
theory and implications, as developed by one of us (BFLW), for a UV finite
theory of quantum general relativity.


title:
Temporal Evolution Of Thermal Emission From Relativistically Expanding
  Plasma

abstract:
  Propagation of photons in relativistically expanding plasma outflows,
characterized by steady Lorentz factor Gamma is considered. Photons that are
injected in regions of high optical depth are advected with the flow until they
escape at the photosphere. Below the photosphere, the photons are coupled to
the plasma via Compton scattering. I show here, that as a result of the slight
misalignment of the scattering electrons velocity vectors, the (local) comoving
photon energy decreases with radius as epsilon'(r) ~ r^{-2/3}. This mechanism
dominates the photon cooling in scenarios of faster adiabatic cooling of the
electrons. I then show that the photospheric radius of a relativistically
expanding plasma wind strongly depends on the angle to the line of sight,
theta. For theta <~ 1/Gamma, r_{ph} is theta independent, while for theta >~
1/Gamma, r_{ph} ~ theta^2. I show that the theta dependence of the photosphere
implies that for flow parameters characterizing GRBs, thermal photons
originating from below the photosphere can be observed up to tens of seconds
following the inner engine activity decay. I calculate the probability density
function P(r,theta) of a thermal photon to escape the plasma at radius r and
angle theta. Using this function, I show that following the termination of the
internal photon injection mechanism, the thermal flux decreases as F_{BB}^{ob.}
~ t^{-2}, and that the decay of the photon energy with radius results in a
power law decay of the observed temperature, T^{ob.}(t) ~ t^{-2/3} at early
times, which changes to t^{-1/2} later. Detailed numerical results are in very
good agreement with the analytical predictions. I discuss the consequences of
this temporal behavior in view of the recent evidence for a thermal emission
component observed during the prompt emission phase of GRBs.


title: (Generalized) Post Correspondence Problem and semi-Thue systems

abstract:
  Let PCP(k) denote the Post Correspondence Problem for k input pairs of
strings. Let ACCESSIBILITY(k) denote the the word problem for k-rule semi-Thue
systems. In 1980, Claus showed that if ACCESSIBILITY(k) is undecidable then
PCP(k + 4) is also undecidable. The aim of the paper is to present a clean,
detailed proof of the statement.
  We proceed in two steps, using the Generalized Post Correspondence Problem as
an auxiliary. First, we prove that if ACCESSIBILITY(k) is undecidable then
GPCP(k + 2) is also undecidable. Then, we prove that if GPCP(k) is undecidable
then PCP(k + 2) is also undecidable. (The latter result has also been shown by
Harju and Karhumaki.) To date, the sharpest undecidability bounds for both PCP
and GPCP have been deduced from Claus's result: since Matiyasevich and
Senizergues showed that ACCESSIBILITY(3) is undecidable, GPCP(5) and PCP(7) are
undecidable.


title: Schlicht envelopes of holomorphy and foliations by lines

abstract:
  Given a domain Y in a complex manifold X, it is a difficult problem with no
general solution to determine whether Y has a schlicht envelope of holomorphy
in X, and if it does, to describe the envelope. The purpose of this paper is to
tackle the problem with the help of a smooth 1-dimensional foliation F of X
with no compact leaves. We call a domain Y in X an interval domain with respect
to F if Y intersects every leaf of F in a nonempty connected set. We show that
if X is Stein and if F satisfies a new property called quasiholomorphicity,
then every interval domain in X has a schlicht envelope of holomorphy, which is
also an interval domain. This result is a generalization and a global version
of a well-known lemma from the mid-1980s. We illustrate the notion of
quasiholomorphicity with sufficient conditions, examples, and counterexamples,
and present some applications, in particular to a little-studied boundary
regularity property of domains called local schlichtness.


title:
Anomalous enhancement of quasiparticle current near a potential barrier
  in a Bose-Einstein condensate

abstract:
  We investigate tunneling properties of Bogoliubov phonons in a Bose-Einstein
condensate. We find the anomalous enhancement of the quasiparticle current
$J_{\rm q}$ carried by Bogoliubov phonons near a potential barrier, due to the
supply of the excess current from the condensate. This effect leads to the
increase of quasiparticle transmission probability in the low energy region
found by Kovrizhin {\it et al.}. We also show that the quasiparticle current
twists the phase of the condensate wavefunction across the barrier, leading to
a finite Josephson supercurrent $J_{\rm s}$ through the barrier. This induced
supercurrent flows in the opposite direction to the quasiparticle current so as
to cancel out the enhancement of $J_{\rm q}$ and conserve the total current
$J=J_{\rm q}+J_{\rm s}$.


title: On the calculation of Schottky contact resistivity

abstract:
  This numerical study examines the importance of self-consistently accounting
for transport and electrostatics in the calculaiton of semiconductor/metal
Schottky contact resistivity. It is shown that ignoring such self-consistency
results in significant under-estimation of the contact resistivity. An explicit
numerical method has also been proposed to efficiently improve contact
resistivity calculations.


title: Laminating lattices with symmetrical glue

abstract:
  We use the automorphism group $Aut(H)$, of holes in the lattice
$L_8=A_2\oplus A_2\oplus D_4$, as the starting point in the construction of
sphere packings in 10 and 12 dimensions. A second lattice, $L_4=A_2\oplus A_2$,
enters the construction because a subgroup of $Aut(L_4)$ is isomorphic to
$Aut(H)$. The lattices $L_8$ and $L_4$, when glued together through this
relationship, provide an alternative construction of the laminated lattice in
twelve dimensions with kissing number 648. More interestingly, the action of
$Aut(H)$ on $L_4$ defines a pair of invariant planes through which dense,
non-lattice packings in 10 dimensions can be constructed. The most symmetric of
these is aperiodic with center density 1/32. These constructions were prompted
by an unexpected arrangement of 378 kissing spheres discovered by a search
algorithm.


title: Self-organized plane arrays of metallic magnetic elements

abstract:
  We studied the dynamic magnetic properties of plane periodical arrays of
circular permalloy nano-dots fabricated using a self-organized mask formed by
polysterene nanospheres on the surface of a Permalloy film. Conventional
(microwave cavity) and broadband coplanar-line ferromagnetic resonance setups
were used for the measurements. We found several well resolved resonance peaks.
This result shows that the self-organized mask fabrication technique is able to
produce high-quality samples with small dispersion of geometrical and magnetic
parameters.


title:
Direct numerical simulation of homogeneous nucleation and growth in a
  phase-field model using cell dynamics method

abstract:
  Homogeneous nucleation and growth in a simplest two-dimensional phase field
model is numerically studied using the cell dynamics method. Whole process from
nucleation to growth is simulated and is shown to follow closely the
Kolmogorov-Johnson-Mehl-Avrami (KJMA) scenario of phase transformation.
Specifically the time evolution of the volume fraction of new stable phase is
found to follow closely the KJMA formula. By fitting the KJMA formula directly
to the simulation data, not only the Avrami exponent but the magnitude of
nucleation rate and, in particular, of incubation time are quantitatively
studied. The modified Avrami plot is also used to verify the derived KJMA
parameters. It is found that the Avrami exponent is close to the ideal
theoretical value m=3. The temperature dependence of nucleation rate follows
the activation-type behavior expected from the classical nucleation theory. On
the other hand, the temperature dependence of incubation time does not follow
the exponential activation-type behavior. Rather the incubation time is
inversely proportional to the temperature predicted from the theory of
Shneidman and Weinberg [J. Non-Cryst. Solids {\bf 160}, 89 (1993)]. A need to
restrict thermal noise in simulation to deduce correct Avrami exponent is also
discussed.


title: Optimal boarding method for airline passengers

abstract:
  Using a Markov Chain Monte Carlo optimization algorithm and a computer
simulation, I find the passenger ordering which minimizes the time required to
board the passengers onto an airplane. The model that I employ assumes that the
time that a passenger requires to load his or her luggage is the dominant
contribution to the time needed to completely fill the aircraft. The optimal
boarding strategy may reduce the time required to board and airplane by over a
factor of four and possibly more depending upon the dimensions of the aircraft.
In addition, knowledge of the optimal boarding procedure can inform decisions
regarding changes to methods that are employed by a particular carrier. I
explore some of the salient features of the optimal boarding method and discuss
practical modifications to the optimal. Finally, I mention some of the benefits
that could come from implementing an improved passenger boarding scheme.


title: Contractively complemented subspaces of pre-symmetric spaces

abstract:
  In 1965, Ron Douglas proved that if $X$ is a closed subspace of an
$L^1$-space and $X$ is isometric to another $L^1$-space, then $X$ is the range
of a contractive projection on the containing $L^1$-space. In 1977
Arazy-Friedman showed that if a subspace $X$ of $C_1$ is isometric to another
$C_1$-space (possibly finite dimensional), then there is a contractive
projection of $C_1$ onto $X$. In 1993 Kirchberg proved that if a subspace $X$
of the predual of a von Neumann algebra $M$ is isometric to the predual of
another von Neumann algebra, then there is a contractive projection of the
predual of $M$ onto $X$.
  We widen significantly the scope of these results by showing that if a
subspace $X$ of the predual of a $JBW^*$-triple $A$ is isometric to the predual
of another $JBW^*$-triple $B$, then there is a contractive projection on the
predual of $A$ with range $X$, as long as $B$ does not have a direct summand
which is isometric to a space of the form $L^\infty(\Omega,H)$, where $H$ is a
Hilbert space of dimension at least two. The result is false without this
restriction on $B$.


title: Brane webs and 1/4-BPS geometries

abstract:
  We discuss brane webs preserving eight supercharges and derive geometries
produced by them. Consistency conditions of supergravity are shown to impose
certain requirements on the locations of the sources, and these restrictions
are found to be in a perfect agreement with results of the probe analysis. In
particular, solutions of IIB SUGRA describing (p,q) stings are inconsistent,
unless the web consists of straight line segments whose orientation is
correlated with charges of the string. The geometries produced by membranes and
D3 branes are only consistent if brane profiles are holomorphic. Using
perturbation theory, we show that a unique gravity solution exists for any
allowed distribution of sources. We also revisit 1/4-BPS geometries with AdS_p
x S^q asymptotics and derive the boundary conditions leading to regular
geometries. All degenerate limits of regular solutions are shown to agree with
expectations from the brane probe analysis.


title:
Green's function approach to quantum criticality in the anisotropic
  Kondo-necklace model

abstract:
  We have studied the quantum phase transition between the antiferromagnetic
and spin liquid phase for the two dimensional anisotropic Kondo-necklace model.
The bond operator formalism has been implemented to transform the spin
Hamiltonian to a bosonic one. We have used the Green's function approach
including a hard core repulsion to find the low energy excitation spectrum of
the model. The bosonic excitations become gapless at the quantum critical point
where the phase transition from the Kondo singlet state to long range
antiferromagnetic order takes place. We have studied the effect of both
inter-site (delta) and local (Delta) anisotropies on the critical point and on
the critical exponent of the excitation gap in the paramagnetic phase. We have
also compared our results with previous bond operator mean field calculations.


title: The Molecular Hydrogen Deficit in Gamma-Ray Burst Afterglows

abstract:
  Recent analysis of five gamma-ray burst (GRB) afterglow spectra reveal the
absence of molecular hydrogen absorption lines, a surprising result in light of
their large neutral hydrogen column densities and the detection of H$_2$ in
similar, more local star-forming regions like 30 Doradus in the Large
Magellanic Cloud (LMC). Observational evidence further indicates that the bulk
of the neutral hydrogen column in these sight lines lies 100 pc beyond the
progenitor and that H$_2$ was absent prior to the burst, suggesting that direct
flux from the star, FUV background fields, or both suppressed its formation. We
present one-dimensional radiation hydrodynamical models of GRB host galaxy
environments, including self-consistent radiative transfer of both ionizing and
Lyman-Werner photons, nine-species primordial chemistry with dust formation of
H$_2$, and dust extinction of UV photons. We find that a single GRB progenitor
is sufficient to ionize neutral hydrogen to distances of 50 - 100 pc but that a
galactic Lyman-Werner background is required to dissociate the molecular
hydrogen in the ambient ISM. Intensities of 0.1 - 100 times the Galactic mean
are necessary to destroy H$_2$ in the cloud, depending on its density and
metallicity. The minimum radii at which neutral hydrogen will be found in
afterglow spectra is insensitive to the mass of the progenitor or the initial
mass function (IMF) of its cluster, if present.


title: MIMO Networks: the Effects of Interference

abstract:
  Multiple-input/multiple-output (MIMO) systems promise enormous capacity
increase and are being considered as one of the key technologies for future
wireless networks. However, the decrease in capacity due to the presence of
interferers in MIMO networks is not well understood. In this paper, we develop
an analytical framework to characterize the capacity of MIMO communication
systems in the presence of multiple MIMO co-channel interferers and noise. We
consider the situation in which transmitters have no information about the
channel and all links undergo Rayleigh fading. We first generalize the known
determinant representation of hypergeometric functions with matrix arguments to
the case when the argument matrices have eigenvalues of arbitrary multiplicity.
This enables the derivation of the distribution of the eigenvalues of Gaussian
quadratic forms and Wishart matrices with arbitrary correlation, with
application to both single user and multiuser MIMO systems. In particular, we
derive the ergodic mutual information for MIMO systems in the presence of
multiple MIMO interferers. Our analysis is valid for any number of interferers,
each with arbitrary number of antennas having possibly unequal power levels.
This framework, therefore, accommodates the study of distributed MIMO systems
and accounts for different positions of the MIMO interferers.


title: B \to 0^{+}(1^{+}) + missing energy in Unparticle Physics

abstract:
  We examine the effects of an unparticle $\mathcal{U}$ as a possible source of
missing energy in the p-wave decays of $B$ meson. The dependence of the
differential branching ratio on the $K_{0}^{\ast}(K_{1}) -$% meson's energy is
discussed in the presence of scalar and vector unparticle operators and
significant deviation from the standard model value is found after addition of
these operators. Finally, we have shown the dependence of branching ratio for
the above said decays on the parameters of the unparticle stuff like the
effective couplings, cutoff scale $\Lambda_{% \mathcal{U}}$ and the scale
dimensions $d_{\mathcal{U}}$.


title:
Exclusive B-> K_{1}l ^{+}l ^{-} decay in model with single universal
  extra dimension

abstract:
  Decay rate and forward-backward asymmetries in B -> K_{1} l^{+} l ^{-}, K_{1}
is the axial vector meson, are calculated in the universal extra dimension
(UED) model. The dependence of these physical quantities on the
compactification radius $R$, the only unknown parameter in UED model, is
studied and it is shown that zero of forward-backward asymmetry is sensitive to
the UED model, therefore they can be very useful tool to establish new physics
predicted by the UED model. This work is briefly extended to B ->
K^{*}l^{+}l^{-}.


title: Multi-Black Rings on Eguchi-Hanson Space

abstract:
  We construct new supersymmetric multi-black ring solutions on the
Eguchi-Hanson base space as solutions of the five-dimensional minimal
supergravity. The space-time has an asymptotically locally Euclidean time
slice, i.e., it has the spatial infinity with the topology of the lens space
$L(2;1)=S^3/Z_2$. The configurations of black rings are restricted by the
requirement of the absence of a Dirac-Misner string everywhere outside
horizons. Especially, in the case of two black rings, the solutions have the
limit to a pair of rotating black holes with the horizon topology of S^3.


title: Mordell-Weil Problem for Cubic Surfaces, Numerical Evidence

abstract:
  Let V be a plane smooth cubic curve over a finitely generated field k. The
Mordell-Weil theorem for V states that there is a finite subset P \subset V(k)
such that the whole V(k) can be obtained from P by drawing secants and tangents
through pairs of previously constructed points and consecutively adding their
new intersection points with V. In this paper we present numerical data
regarding the analogous statement for cubic surfaces. For the surfaces
examined, we also test Manin's conjecture relating the asymptotics of rational
points of bounded height on a Fano variety with the rank of the Picard group of
the surface.


title: Bayesian Checking of the Second Levels of Hierarchical Models

abstract:
  Hierarchical models are increasingly used in many applications. Along with
this increased use comes a desire to investigate whether the model is
compatible with the observed data. Bayesian methods are well suited to
eliminate the many (nuisance) parameters in these complicated models; in this
paper we investigate Bayesian methods for model checking. Since we contemplate
model checking as a preliminary, exploratory analysis, we concentrate on
objective Bayesian methods in which careful specification of an informative
prior distribution is avoided. Numerous examples are given and different
proposals are investigated and critically compared.


title: Quasi-Linear Algebras and Integrability (the Heisenberg Picture)

abstract:
  We study Poisson and operator algebras with the ''quasi-linear property''
from the Heisenberg picture point of view. This means that there exists a set
of one-parameter groups yielding an explicit expression of dynamical variables
(operators) as functions of ''time'' $t$. We show that many algebras with
nonlinear commutation relations such as the Askey-Wilson, $q$-Dolan-Grady and
others satisfy this property. This provides one more (explicit Heisenberg
evolution) interpretation of the corresponding integrable systems.


title: Knowledge management by wikis

abstract:
  Wikis provide a new way of collaboration and knowledge sharing. Wikis are
software that allows users to work collectively on a web-based knowledge base.
Wikis are characterised by a sense of anarchism, collaboration, connectivity,
organic development and self-healing, and they rely on trust. We list several
concerns about applying wikis in professional organisation. After these
concerns are met, wikis can provide a progessive, new knowledge sharing and
collaboration tool.


title: Comment: Bayesian Checking of the Second Levels of Hierarchical Models

abstract:
  We discuss the methods of Evans and Moshonov [Bayesian Analysis 1 (2006)
893--914, Bayesian Statistics and Its Applications (2007) 145--159] concerning
checking for prior-data conflict and their relevance to the method proposed in
this paper. [arXiv:0802.0743]


abstract:
  Comment: Bayesian Checking of the Second Levels of Hierarchical Models
[arXiv:0802.0743]


title:
Theory of large-scale matrix computation and applications to electronic
  structure calculation

abstract:
  We review our recently developed methods for large-scale electronic structure
calculations, both in one-electron theory and many-electron theory. The method
are based on the density matrix representation, together with the Wannier state
representation and the Krylov subspace method, in one-electron theory of
a-few-tens nm scale systems. The hybrid method of quantum mechanical molecular
dynamical simulation is explained.The Krylov subspace method, the CG (conjugate
gradient) method and the shifted-COCG (conjugate orthogonal conjugate gradient)
method, can be applied to the investigation of the ground state and the
excitation spectra in many-electron theory. The mathematical foundation of the
Krylov subspace method for large-scale matrix computation is focused and the
key technique of the shifted-COCG method, e.g. the collinear residual and seed
switching, is explained. A wide variety of applications of these extended novel
algorithm is also explained. These are the fracture formation and propagation,
liquid carbon and formation process of gold nanowires, together with the
application to the extend Hubbard model.


title: Intrinsic and extrinsic properties of quantum systems

abstract:
  The paper attempts to convince that the orthodox interpretation of quantum
mechanics does not contradict philosophical realism by throwing light onto
certain properties of quantum systems that seem to have escaped attention as
yet. The exposition starts with the philosophical notions of realism. Then, the
quantum mechanics as it is usually taught is demoted to a mere part of the
theory called phenomenology of observations, and the common impression about
its contradiction to realism is explained. The main idea of the paper, the
physical notion of intrinsic properties, is introduced and many examples
thereof are given. It replaces the irritating dichotomy of quantum and
classical worlds by a much softer difference between intrinsic and extrinsic
properties, which concern equally microscopic and macroscopic systems. Finally,
the classicality and the quantum measurement are analyzed and found to present
some still unsolved problems. A possible way of dealing with the
Schr\"{o}dinger cat is suggested that is based on the intrinsic properties. A
simple quantum model of one classical property illustrates how our philosophy
may work.


title:
The Variational Principle for the Uniform Acceleration and Quasi-Spin in
  Two Dimensional Space-Time

abstract:
  The variational principle and the corresponding differential equation for
geodesic circles in two dimensional (pseudo)-Riemannian space are being
discovered. The relationship with the physical notion of uniformly accelerated
relativistic particle is emphasized. The known form of spin-curvature
interaction emerges due to the presence of second order derivatives in the
expression for the Lagrange function. The variational equation itself reduces
to the unique invariant variational equation of constant Frenet curvature in
two dimensional (pseudo)-Euclidean geometry.


title:
Comment: Bayesian Checking of the Second Level of Hierarchical Models:
  Cross-Validated Posterior Predictive Checks Using Discrepancy Measures

abstract:
  Comment: Bayesian Checking of the Second Level of Hierarchical Models
[arXiv:0802.0743]


title: Using complex networks to model 2-D and 3-D soil porous architecture

abstract:
  This paper has been withdrawn by the author to comply with the journal policy
to which it has been submitted.


abstract:
  Rejoinder: Bayesian Checking of the Second Levels of Hierarchical Models
[arXiv:0802.0743]


title:
Propagators associated to periodic Hamiltonians: an example of the
  Aharonov-Bohm Hamiltonian with two vortices

abstract:
  We consider an invariant quantum Hamiltonian $H=-\Delta_{LB}+V$ in the
$L^{2}$ space based on a Riemannian manifold $\tilde{M}$ with a discrete
symmetry group $\Gamma$. Typically, $\tilde{M}$ is the universal covering space
of a multiply connected manifold $M$ and $\Gamma$ is the fundamental group of
$M$. To any unitary representation $\Lambda$ of $\Gamma$ one can relate another
operator on $M=\tilde{M}/\Gamma$, called $H_\Lambda$, which formally
corresponds to the same differential operator as $H$ but which is determined by
quasi-periodic boundary conditions. We give a brief review of the Bloch
decomposition of $H$ and of a formula relating the propagators associated to
the Hamiltonians $H_\Lambda$ and $H$. Then we concentrate on the example of the
Aharonov-Bohm effect with two vortices. We explain in detail the construction
of the propagator in this case and indicate all essential intermediate steps.


title:
A theoretical approach to the interaction between buckling and resonance
  instabilities

abstract:
  The paper deals with the interaction between buckling and resonance
instabilities of mechanical systems. Taking into account the effect of
geometric nonlinearity in the equations of motion through the geometric
stiffness matrix, the problem is reduced to a generalized eigenproblem where
both the loading multiplier and the natural frequency of the system are
unknown. According to this approach, all the forms of instabilities
intermediate between those of pure buckling and pure forced resonance can be
investigated. Numerous examples are analyzed, including: discrete mechanical
systems with one to n degrees of freedom, continuous mechanical systems such as
oscillating deflected beams subjected to a compressive axial load, as well as
oscillating beams subjected to lateral-torsional buckling. A general finite
element procedure is also outlined, with the possibility to apply the proposed
approach to any general bi- or tri-dimensional framed structure. The proposed
results provide a new insight in the interpretation of coupled phenomena such
as flutter instability of long-span or high-rise structures.


title:
Bilinearization and Casorati determinant solution to the non-autonomous
  discrete KdV equation

abstract:
  Casorati determinant solution to the non-autonomous discrete KdV equation is
constructed by using the bilinear formalism. We present three different
bilinear formulations which have different origins.


title:
Dissipative structures of diffuse molecular gas III -- Small-scale
  intermittency of intense velocity-shears

abstract:
  We further characterize the structures tentatively identified on thermal and
chemical grounds as the sites of dissipation of turbulence in molecular clouds
(Papers I and II). Our study is based on two-point statistics of line centroid
velocities (CV), computed from three large 12CO maps of two fields. Probability
density functions (PDF) of the CO line centroid velocity increments (CVI) over
lags varying by an order of magnitude and structure functions of the line CV,
up to the 6th order, are computed. We show that the line CV bear the three
signatures of intermittency in a turbulent velocity field: (1) the non-Gaussian
tails in the CVI PDF grow as the lag decreases, (2) the departure from
Kolmogorov scaling of the high-order structure functions is more pronounced in
the more turbulent field, (3) the positions contributing to the CVI PDF tails
delineate narrow filamentary structures (thickness ~ 0.02 pc), uncorrelated to
dense gas structures and spatially coherent with thicker ones (~0.18 pc)
observed on larger scales. The confrontation with theoretical predictions leads
us to identify these small-scale filamentary structures with extrema of
velocity-shears associated with gas warmer than the bulk. Last, their average
direction is parallel (or close) to that of the local magnetic field
projection. Turbulence in these translucent fields exhibits the statistical and
structural signatures of small-scale and inertial-range intermittency. The more
turbulent field on the 30 pc-scale is also the more intermittent on small
scales. The small-scale intermittent structures coincide with those formerly
identified as sites of enhanced dissipation. They are organized into
parsec-scale coherent structures, coupling a broad range of scales.


title: On Ricci solitons of cohomogeneity one

abstract:
  We analyse some properties of the cohomogeneity one Ricci soliton equations,
and use Ansatze of cohomogeneity one type to produce new explicit examples of
complete Kahler Ricci solitons of expanding, steady and shrinking types. These
solitons are foliated by hypersurfaces which are circle bundles over a product
of Fano Kahler-Einstein manifolds or over coadjoint orbits of a compact
connected semisimple Lie group.


title: Testing the Hilbert space dimension

abstract:
  Given a set of correlations originating from measurements on a quantum state
of unknown Hilbert space dimension, what is the minimal dimension d necessary
to describes such correlations? We introduce the concept of dimension witness
to put lower bounds on d. This work represents a first step in a broader
research program aiming to characterize Hilbert space dimension in various
contexts related to fundamental questions and Quantum Information applications.


title: Degeneracy of Decadent Dyons

abstract:
  A quarter-BPS dyon in $\mathcal{N}=4$ super Yang-Mills theory is generically
`decadent' in that it is stable only in some regions of the moduli space and
decays on submanifolds in the moduli space. Using this fact, and from the
degeneracy of the system close to the decay, a new derivation for the
degeneracy of such dyons is given. The degeneracy obtained from these very
simple physical considerations is in precise agreement with the results
obtained from index computations in all known cases. Similar considerations
apply to dyons in $\mathcal{N}=2$ gauge theories. The relation between the
$\mathcal{N} =4 $ field theory dyons and those counted by the Igusa cusp form
in toroidally compactified heterotic string is elucidated.


title: Chameleon Vector Bosons

abstract:
  We show that for a force mediated by a vector particle coupled to a conserved
U(1) charge, the apparent range and strength can depend on the size and density
of the source, and the proximity to other sources. This "chameleon" effect is
due to screening from a light charged scalar. Such screening can weaken
astrophysical constraints on new gauge bosons. As an example we consider the
constraints on chameleonic gauged B-L. We show that although Casimir
measurements greatly constrain any B-L force much stronger than gravity with
range longer than 0.1 microns, there remains an experimental window for a long
range chameleonic B-L force. Such a force could be much stronger than gravity,
and long or infinite range in vacuum, but have an effective range near the
surface of the earth which is less than a micron.


title: On factoriality of Cox rings

abstract:
  Generalized Cox's construction associates with an algebraic variety a
remarkable invariant -- its total coordinate ring, or Cox ring. In this note we
give a new proof of factoriality of the Cox ring when the divisor class group
of the variety is finitely generated and free. The proof is based on a notion
of graded factoriality. We show that if the divisor class group has torsion,
then the Cox ring is again factorially graded, but factoriality may be lost.


title: The Steinberg Variety and Representations of Reductive Groups

abstract:
  We give an overview of some of the main results in geometric representation
theory that have been proved by means of the Steinberg variety. Steinberg's
insight was to use such a variety of triples in order to prove a conjectured
formula by Grothendieck.
  The Steinberg variety was later used to give an alternative approach to
Springer's representations and played a central role in the proof of the
Deligne-Langlands conjecture for Hecke algebras by Kazhdan and Lusztig.


title: On the local time of the asymmetric Bernoulli walk

abstract:
  We study some properties of the local time of the asymmetric Bernoulli walk
on the line. These properties are very similar to the corresponding ones of the
simple symmetric random walks in higher ($d\geq3$) dimension, which we
established in the recent years. The goal of this paper is to highlight these
similarities.


title:
Modelling and Analysis of the Distributed Coordination Function of IEEE
  802.11 with Multirate Capability

abstract:
  The aim of this paper is twofold. On one hand, it presents a
multi-dimensional Markovian state transition model characterizing the behavior
at the Medium Access Control (MAC) layer by including transmission states that
account for packet transmission failures due to errors caused by propagation
through the channel, along with a state characterizing the system when there
are no packets to be transmitted in the queue of a station (to model
non-saturated traffic conditions). On the other hand, it provides a throughput
analysis of the IEEE 802.11 protocol at the data link layer in both saturated
and non-saturated traffic conditions taking into account the impact of both
transmission channel and multirate transmission in Rayleigh fading environment.
Simulation results closely match the theoretical derivations confirming the
effectiveness of the proposed model.


title:
A fundamental length as a candidate for dark energy: a DSR inspired FRW
  spacetime

abstract:
  We show that the existence of a fundamental length, introduced in Deformed
Special Relativity (DSR) inspired minisuper (phase-) space, causes the behavior
of the scale factor of the universe to change from that of a universe filled
with dust to an accelerating universe driven by a cosmological constant.


title: Synchronization between variable time delayed systems and cryptography

abstract:
  In this letter we consider a prototype model which is described as an
autonomous continuous time delayed differential equation with just one
variable. The chaos has been investigated with variable delay time and the
synchronization phenomenon is examined both numerically and analytically using
the Krasovskii-Lyapunov functions. We have applied adaptive coupling law for
synchronization,where the coupling equation also contains delay with modulated
time. We also studied the effect of cryptography for this coupled system and
the message extraction procedure is illustrated with the help of simulated
results.


title: Behavior of sigma(gamma p) at Large Coherence Lengths

abstract:
  Various parametrizations of sigma(gamma p) are tried out on the small-x fixed
target and HERA data. A two-Pomeron type parametrization is found to give the
best reproduction of the data. The data indicate that the value of lambda(eff)
for parametrizations of the form sigma(gamma p)~l^lambda(eff) approaches a
constant value at high Q^2. The extrapolated values of sigma(gamma p) to very
long coherence lengths are found to cross in some parametrizations for l>10^7
fm, indicating the possibility that sigma(gamma p) becomes Q^2 independent at
large values of the coherence length l.


title:
LoCuSS: Comparison of Observed X-ray and Lensing Galaxy Cluster Scaling
  Relations with Simulations

abstract:
  The Local Cluster Substructure Survey (LoCuSS, Smith et al.) is a systematic
multi-wavelength survey of >100 X-ray luminous galaxy clusters (0.14<z<0.3)
selected from the ROSAT all sky survey. We used data on 37 LoCuSS clusters from
the XMM-Newton archive to investigate the global scaling relations of galaxy
clusters. The scaling relations based solely on the X-ray data obey empirical
self-similarity and reveal no additional evolution beyond the LSS growth. Weak
lensing mass measurements are also available in the literature for 19 of the
clusters with XMM-Newton data. The average of the weak lensing mass to X-ray
based mass ratio is 1.09+/-8, setting the limit of the non-thermal pressure
support to 9+/-8%. The mean of the weak lensing mass to X-ray based mass ratio
of these clusters is ~1 with 31-51% scatter. The scatter in the
mass--observable relations (M-Y_X, M-M_{gas} and M-T) is smaller using X-ray
based masses than using weak lensing masses by a factor of 2. Using the scaled
radius defined by the Y_X profile, we obtain lower scatter in the weak lensing
mass based mass--observable relations. The normalization of the M-Y_X relation
(also M-M_{gas} and M-T relations) using X-ray (weak lensing) mass estimates is
lower than the one from simulations by up to 20% at ~3 sigma (~2 sigma)
significance. Despite the large scatter in the X-ray to lensing comparison, the
agreement between these two completely independent observational methods is an
important step towards controlling astrophysical and measurement systematics in
cosmological scaling relations.