title:
On the k-Symplectic, k-Cosymplectic and Multisymplectic Formalisms of
  Classical Field Theories

abstract:
  The objective of this work is twofold: First, we analyze the relation between
the k-cosymplectic and the k-symplectic Hamiltonian and Lagrangian formalisms
in classical field theories. In particular, we prove the equivalence between
k-symplectic field theories and the so-called autonomous k-cosymplectic field
theories, extending in this way the description of the symplectic formalism of
autonomous systems as a particular case of the cosymplectic formalism in
non-autonomous mechanics. Furthermore, we clarify some aspects of the geometric
character of the solutions to the Hamilton-de Donder-Weyl and the
Euler-Lagrange equations in these formalisms. Second, we study the equivalence
between k-cosymplectic and a particular kind of multisymplectic Hamiltonian and
Lagrangian field theories (those where the configuration bundle of the theory
is trivial).


title:
Integral Field Spectroscopy of the Extended Emission-Line Region of 4C
  37.43

abstract:
  We present Gemini integral field spectroscopy and Keck II longslit
spectroscopy of the extended emission-line region (EELR) around the quasar 4C
37.43. The velocity structure of the ionized gas is complex and cannot be
explained globally by a simple dynamical model. The spectra from the clouds are
inconsistent with shock or ``shock + precursor'' ionization models, but they
are consistent with photoionization by the quasar nucleus. The best-fit
photoionization model requires a low-metallicity (12+log(O/H) < 8.7) two-phase
medium, consisting of a matter-bounded diffuse component with a unity
filling-factor (N ~ 1 \cc, T ~ 15000 K), in which are embedded small, dense
clouds (N ~ 400 \cc, T ~ 10^4 K). The high-density clouds are transient and can
be re-generated through compressing the diffuse medium by low-speed shocks (V_S
\lesssim 100 \kms). Our photoionization model gives a total mass for the
ionized gas of about 3x10^{10} M_sun, and the total kinetic energy implied by
this mass and the observed velocity field is ~2x10^{58} ergs. The fact that
luminous EELRs are confined to steep-spectrum radio-loud quasars, yet show no
morphological correspondence to the radio jets, suggests that the driving force
producing the 4C 37.43 EELR was a roughly spherical blast wave initiated by the
production of the jet. That such a mechanism seems capable of ejecting a mass
comparable to that of the total interstellar medium of the Milky Way suggests
that ``quasar-mode'' feedback may indeed be an efficient means of regulating
star formation in the early universe.


title:
Critical mass of bacterial populations in a generalized Keller-Segel
  model. Analogy with the Chandrasekhar limiting mass of white dwarf stars

abstract:
  We point out a remarkable analogy between the limiting mass of white dwarf
stars (Chandrasekhar's limit) and the critical mass of bacterial populations in
a generalized Keller-Segel model of chemotaxis [Chavanis & Sire, PRE, 69,
016116 (2004)]. This model is based on generalized stochastic processes leading
to the Tsallis statistics. The equilibrium states correspond to polytropic
configurations similar to gaseous polytropes in astrophysics. For the critical
index n_3=d/(d-2) (where d is the dimension of space), the theory of polytropes
leads to a unique value of the mass M_c that we interpret as a limiting mass.
In d=3, we find M_c=202.8956... and in d=2, we recover the well-known result
M_c=8 pi (in suitable units). For M<M_c, the system evaporates (in an infinite
domain) or tends to an equilibrium state (for box-confined configurations). For
M>M_c, the system collapses and forms a Dirac peak containing a mass M_c
surrounded by a halo. This paper exposes the model and shows, by simple
considerations, the origin of the critical mass. A detailed description of the
critical dynamics of the generalized Keller-Segel model will be given in a
forthcoming paper.


title: Beauty and Charm Production Measurements at the Tevatron

abstract:
  Results for the production of charm and beauty quarks in proton anti-proton
collisions at ECM=1.96 TeV (Tevatron) with the two multi purpose experiments
CDF and D0 using an integrated luminosity of up to 1 fb^-1 are presented. With
the data measurement of the production me chanism for charm and beauty quarks
are done. These measurements are leading to a better understanding of the QCD
in the transition region between pertubative a nd nonpertubative QCD. The
charm-charm angular correlation is measured with D me sons at the CDF
experiment. The Quarkonium production for charm and beauty final state at D0
and CDF is discussed.


title:
Extending the range of error estimates for radial approximation in
  Euclidean space and on spheres

abstract:
  We adapt Schaback's error doubling trick [R. Schaback. Improved error bounds
for scattered data interpolation by radial basis functions. Math. Comp.,
68(225):201--216, 1999.] to give error estimates for radial interpolation of
functions with smoothness lying (in some sense) between that of the usual
native space and the subspace with double the smoothness. We do this for both
bounded subsets of R^d and spheres. As a step on the way to our ultimate goal
we also show convergence of pseudoderivatives of the interpolation error.


title: Computing Integer Powers in Floating-Point Arithmetic

abstract:
  We introduce two algorithms for accurately evaluating powers to a positive
integer in floating-point arithmetic, assuming a fused multiply-add (fma)
instruction is available. We show that our log-time algorithm always produce
faithfully-rounded results, discuss the possibility of getting correctly
rounded results, and show that results correctly rounded in double precision
can be obtained if extended-precision is available with the possibility to
round into double precision (with a single rounding).


title:
Asymptotic conformal Yano-Killing tensors for asymptotic anti-de Sitter
  spacetimes and conserved quantities

abstract:
  Conformal rescaling of conformal Yano--Killing tensors and relations between
Yano and CYK tensors are discussed. Pullback of these objects to a submanifold
is used to construct all solutions of a CYK equation in anti-de Sitter and de
Sitter spacetimes. Properties of asymptotic conformal Yano--Killing tensors are
examined for asymptotic anti-de Sitter spacetimes. Explicit asymptotic forms of
them are derived. The results are used to construct asymptotic charges in
asymptotic AdS spacetime. Well known examples like Schwarzschild-AdS, Kerr-AdS
and NUT-AdS are examined carefully in the construction of the concept of
energy, angular momentum and dual mass in asymptotic AdS spacetime.


title:
Stable simulation of fluid flow with high-Reynolds number using
  Ehrenfests' steps

abstract:
  The Navier--Stokes equations arise naturally as a result of Ehrenfests'
coarse-graining in phase space after a period of free-flight dynamics. This
point of view allows for a very flexible approach to the simulation of fluid
flow for high-Reynolds number. We construct regularisers for lattice Boltzmann
computational models. These regularisers are based on Ehrenfests'
coarse-graining idea and could be applied to schemes with either entropic or
non-entropic quasiequilibria. We give a numerical scheme which gives good
results for the standard test cases of the shock tube and the flow past a
square cylinder.


title:
Generating Minimally Coupled Einstein-Scalar Field Solutions from Vacuum
  Solutions with Arbitrary Cosmological Constant

abstract:
  This paper generalizes two previously known techniques for generating
minimally coupled Einstein-scalar field solutions in 4 dimensions; the Buchdahl
and Fonarev transformations. By applying this solution generation technique,
minimally coupled Einstein-scalar field solutions can be generated from vacuum
solutions with arbitrary cosmological constant in arbitrary dimension. The only
requirement to a seed solution is that it posesses a hypersurface-orthogonal
Killing vector field. The generalization that allows us to use seed solutions
with arbitrary cosmological constant uncovers a new class of Einstein-scalar
field solutions that has previously not been studied. We apply the new solution
transformation to the (A)dS4 vacuum solution. Transforming the resulting
Einstein-scalar field solution to the conformal frame, a two-parameter family
of spatially finite, expanding and accelerating cosmological solutions are
found that are conformally isometric to the Einstein static universe RxS^3. We
study null geodesics and find that for any observer, the solution has a
cosmological horizon at an angular distance of pi/2 away from the observer. We
find that a subset of these solutions can be naturally interpreted as expanding
cosmologies in which a scalar black hole is formed at late times. The
conformally coupled scalar field satisfies the weak energy condition as long as
the energy density is positive, while the strong energy condition is generally
violated.


title:
Relationship between the linear entropy, the von Neumann entropy and the
  atomic Wehrl entropy for the Jaynes-Cummings model

abstract:
  The linear entropy, the von Neumann entropy and the atomic Wehrl entropy are
frequently used to quantify entanglement in the quantum systems. These
relations provide typical information on the entanglement in the
Jaynes-Cummings model (JCM). In this Letter, we explain the origin of this
analytically and derive a closed form for the atomic Wehrl entropy. Moreover,
we show that it is more convenient to use the Bloch sphere radius for
quantifying entanglement in the JCM instead of these entropic relations.


title: Enhancing SPH using moving least-squares and radial basis functions

abstract:
  In this paper we consider two sources of enhancement for the meshfree
Lagrangian particle method smoothed particle hydrodynamics (SPH) by improving
the accuracy of the particle approximation. Namely, we will consider shape
functions constructed using: moving least-squares approximation (MLS); radial
basis functions (RBF). Using MLS approximation is appealing because polynomial
consistency of the particle approximation can be enforced. RBFs further appeal
as they allow one to dispense with the smoothing-length -- the parameter in the
SPH method which governs the number of particles within the support of the
shape function. Currently, only ad hoc methods for choosing the
smoothing-length exist. We ensure that any enhancement retains the conservative
and meshfree nature of SPH. In doing so, we derive a new set of
variationally-consistent hydrodynamic equations. Finally, we demonstrate the
performance of the new equations on the Sod shock tube problem.


title:
Imaging of Thermal Domains in ultrathin NbN films for Hot Electron
  Bolometers

abstract:
  We present low-temperature scanning electron microscopy (LTSEM)
investigations of superconducting microbridges made from ultrathin NbN films as
used for hot electron bolometers. LTSEM probes the thermal structure within the
microbridges under various dc current bias conditions, either via
electron-beam-induced generation of an unstable hotspot, or via the
beam-induced growth of a stable hotspot. Such measurements reveal
inhomogeneities on a micron scale, which may be due to spatial variations in
the NbN film or film-interface properties. Comparison with model calculations
for the stable hotspot regime confirm the basic features of common hot spot
models.


title: Construction of C operator for a PT symmetric model

abstract:
  We obtain closed form expression of the C(x,y) operator for the PT symmetric
Scarf I potential. It is also shown that the eigenfunctions are complete.


title: Ground-State Properties of a One-Dimensional System of Hard Rods

abstract:
  A quantum Monte Carlo simulation of a system of hard rods in one dimension is
presented and discussed. The calculation is exact since the analytical form of
the wavefunction is known, and is in excellent agreement with predictions
obtained from asymptotic expansions valid at large distances. The analysis of
the static structure factor and the pair distribution function indicates that a
solid-like and a gas-like phases exist at high and low densities, respectively.
The one-body density matrix decays following a power-law at large distances and
produces a divergence in the low density momentum distribution at k=0 which can
be identified as a quasi-condensate.


title: Einstein and early 20th Century avant-garde art: points of contact?

abstract:
  Art history linked some early 20th Century avant-garde visual art movements
to contemporary systems of ideas in mathematics and theoretical physics. One of
the proposed connections is the one that might have existed between Cubism and
Relativity, or more precisely, between Picasso and Einstein. The suggested
links are similarity (in a weak version) or identity (in a strong version) in
matters of space, time and simultaneity. It is possible, however, that these
supposed links of Einstein and avant-garde art movements were more the product
of the imagination of historians and critics, than the result of connections
between painters and scientists. On the one hand, the visual arts (in contrast
to music, as far as we now) were of no interest to Einstein, who, moreover, did
not seem inclined or knowledgeable enough to appreciate advanced forms. On the
other hand, Einstein's theories fell outside the artists' ken, let alone their
understanding, although there are firm clues pointing to the fact that
repercussions of those theories in the press and in literary circles could have
fired the imagination of some artists.


title:
Structural distortions and model Hamiltonian parameters: from LSDA to a
  tight-binding description of LaMnO_3

abstract:
  The physics of manganites is often described within an effective two-band
tight-binding (TB) model for the Mn e_g electrons, which apart from the kinetic
energy includes also a local "Hund's rule" coupling to the t_{2g} core spin and
a local coupling to the Jahn-Teller (JT) distortion of the oxygen octahedra. We
test the validity of this model by comparing the energy dispersion calculated
for the TB model with the full Kohn-Sham band-structure calculated within the
local spin-density approximation (LSDA) to density functional theory. We
analyze the effect of magnetic order, JT distortions, and "GdFeO_3-type"
tilt-rotations of the oxygen octahedra. We show that the hopping amplitudes are
independent of magnetic order and JT distortions, and that both effects can be
described with a consistent set of model parameters if hopping between both
nearest and next-nearest neighbors is taken into account. We determine a full
set of model parameters from the density functional theory calculations, and we
show that both JT distortions and Hund's rule coupling are required to obtain
an insulating ground state within LSDA. Furthermore, our calculations show that
the "GdFeO_3-type" rotations of the oxygen octahedra lead to a substantial
reduction of the hopping amplitudes but to no significant deviation from the
simple TB model.


title: Plasma Modes Along the Open Field Lines of a Neutron Star

abstract:
  We consider electrostatic plasma modes along the open field lines of a
rotating neutron star. Goldreich-Julian charge density in general relativity is
analyzed for the neutron star with zero inclination. It is found that the
charge density is maximum at the polar cap and it remains almost same in
certain extended region of the pole. For a steady state Goldreich-Julian charge
density we found the usual plasma oscillation along the field lines; plasma
frequency resembles to the gravitational redshift close to the Schwarzschild
radius. We study the nonlinear plasma mode along the field lines. From the
system of equations under general relativity, a second order differential
equation is derived. The equation contains a term which describes the growing
plasma modes near Schwarzschild radius in a black hole environment. The term
vanishes with the distance far away from the gravitating object. For initially
zero potential and field on the surface of a neutron star, Goldreich-Julian
charge density is found to create the plasma mode, which is enhanced and
propagates almost without damping along the open field lines. We briefly
outline our plan to extend the work for studying soliton propagation along the
open field lines of strongly gravitating objects.


title:
Holography in Three-dimensional Kerr-de Sitter Space with a
  Gravitational Chern-Simons Term

abstract:
  The holographic description of the three-dimensional Kerr-de Sitter space
with a gravitational Chern-Simons term is studied, in the context of dS/CFT
correspondence. The space has only one (cosmological) event horizon and its
mass and angular momentum are identified from the holographic energy-momentum
tensor at the asymptotic infinity. The thermodynamic entropy of the
cosmological horizon is computed directly from the first law of thermodynamics,
with the usual Hawking temperature, and it is found that the usual
Gibbons-Hawking entropy is modified. It is remarked that, due to the
gravitational Chern-Simons term, (a) the results go beyond analytic
continuation from AdS, (b) the maximum-mass/N-bound conjecture may be violated,
and (c) the three-dimensional cosmology is chiral. A statistical mechanical
computation of the entropy, from a Cardy-like formula for a dual CFT at the
asymptotic boundary, is discussed. Some technical difference in the
Chern-Simons energy-momentum tensor, from literatures is remarked also.


title: Analysis of long range order

abstract:
  A first principles analysis of order-disorder transition in alloys shows that
ordering energy is a function of temperature due to thermal vibrations. The
inter-nuclear potential energy term converges if zero point vibrations are
incorporated and this method can replace the Ewald sum method. Core energy
contributions to the ordering energy are stored exclusively in superlattice
lines. The effect of electron-phonon interactions on ordering energy is of the
same order of magnitude as ordering energy near transition temperatures and
cannot be ignored. Ising model and variants are incorrect in explaining alloy
phase transitions as they ignore the role of electron-phonon interactions
without justification. A theoretical formalism that incorporates the
Debye-Waller Factor component of electron-phonon interactions in electronic
structure calculations already exists and must be adopted when modeling
temperature dependent phenomena. It is suggested that DWF correction will
account substantially for the discrepancy between experimental and theoretical
ordering energy in Ni3V. Thermal vibrations alter magnetic ordering energy at
finite temperatures. The role of electron-phonon interactions in alloy and
magnetic phase transitions cannot be ignored and must be incorporated in all
models. This will also ensure consistency with x-ray and electron diffraction
(alloy transitions) and neutron diffraction (magnetic transitions) results. An
isotope effect is predicted for (magnetic) phase transitions if the transition
temperature is below Debye temperature. Recent observations of an isotope
effect in magnetic phase transitions confirm our above conclusions and imply
that the role of electron-phonon interactions must be incorporated in all
theories and models of magnetism to avoid contradictions.


title:
To a question on the \eta \to \pi^0 \gamma \gamma decay width in
  meson-baryon chiral model

abstract:
  It is shown in the work of one of the authors in 1979 (MKV) that the
contribution to the amplitude of this decay from diagrams with one baryon loop
is equal to zero and contributions from diagrams with meson loops appear very
small. However, pole diagrams with intermediate vector mesons were not
considered there. Here it is shown that contributions of these pole diagrams
dominate. The meson-baryon chiral model used here is compared with known quark
chiral models. The obtained results are in satisfactory agreement with recent
experimental data.


title: A new look at the modified Coulomb potential in a strong magnetic field

abstract:
  The static Coulomb potential of Quantum Electrodynamics (QED) is calculated
in the presence of a strong magnetic field in the lowest Landau level (LLL)
approximation using two different methods. First, the vacuum expectation value
of the corresponding Wilson loop is calculated perturbatively in two different
regimes of dynamical mass $m_{dyn.}$, {\it i.e.}, $|{\mathbf{q}}_{\|}^{2}|\ll
m_{dyn.}^{2}\ll |eB|$ and $m_{dyn.}^{2}\ll |\mathbf{q}_{\|}^{2}|\ll|eB|$, where
$\mathbf{q}_{\|}$ is the longitudinal components of the momentum relative to
the external magnetic field $B$. The result is then compared with the static
potential arising from Born approximation. Both results coincide. Although the
arising potentials show different behavior in the aforementioned regimes, a
novel dependence on the angle $\theta$ between the particle-antiparticle's axis
and the direction of the magnetic field is observed. In the regime
$|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$, for strong enough magnetic
field and depending on the angle $\theta$, a qualitative change occurs in the
Coulomb-like potential; Whereas for $\theta=0,\pi$ the potential is repulsive,
it exhibits a minimum for angles $\theta\in]0,\pi[$.


title:
Table-top creation of entangled multi-keV photon pairs via the Unruh
  effect

abstract:
  Electrons moving in a strong periodic electromagnetic field (e.g., laser or
undulator) may convert quantum vacuum fluctuations into pairs of entangled
photons, which can be understood as a signature of the Unruh effect. Apart from
verifying this striking phenomenon, the considered effect may allow the
construction of a table-top source for entangled photons (``photon pair
laser'') and the associated quantum-optics applications in the multi-keV regime
with near-future facilities. 04.62.+v, 12.20.Fv, 41.60.-m, 42.50.Dv.


title:
Temperature dependence of the impurity-induced resonant state in
  Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by Scanning Tunneling Spectroscopy

abstract:
  We report on the temperature dependence of the impurity-induced resonant
state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by scanning tunneling
spectroscopy at 30 mK < T < 52 K. It is known that a Zn impurity induces a
sharp resonant peak in tunnel spectrum at an energy close to the Fermi level.
We observed that the resonant peak survives up to 52 K. The peak broadens with
increasing temperature, which is explained by the thermal effect. This result
provides information to understand the origin of the resonant peak.


title:
The NMSSM Solution to the Fine-Tuning Problem, Precision Electroweak
  Constraints and the Largest LEP Higgs Event Excess

abstract:
  We present an extended study of how the Next to Minimal
  Supersymmetric Model easily avoids fine-tuning in electroweak symmetry
breaking for a SM-like light Higgs with mass in the vicinity of $100\gev$, as
beautifully consistent with precision electroweak data, while escaping LEP
constraints due to the dominance of $h\to aa$ decays with $m_a<2m_b$ so that
$a\to \tauptaum$ or jets. The residual $\sim 10%$ branching ratio for $h\to
b\anti b$ explains perfectly the well-known LEP excess at $\mh\sim 100\gev$.
Details of model parameter correlations and requirements are discussed as a
function $\tan(\beta)$. Comparisons of fine-tuning in the NMSSM to that in the
MSSM are presented. We also discuss fine-tuning associated with scenarios in
which the $a$ is essentially pure singlet, has mass $m_a>30\gev$, and decays
primarily to $\gam\gam$ leading to an $h\to aa\to 4\gam$ Higgs signal.


title: From Newton to Einstein: the birth of Special Relativity

abstract:
  Physics was in crisis at the beginning of the twentieth century because the
newborn Maxwell's electromagnetism defied mechanistic preconceptions. Albert
Einstein understood that the solution to the crisis required an audacious
reworking of the concepts of space and time. Special Relativity deeply modified
our way of regarding space and time, in order to harmonize electromagnetism
with the principle of relativity. As a consequence, lengths and elapsed times
were stripped of the invariant character that classical Physics conferred them;
in their place, the speed of light acquired that privileged status. Such
revolutionary change forced Einstein to reformulate Newtonian mechanics, a step
that led him to discover the mass-energy equivalence.


title: On simplicial toric varieties of codimension 2

abstract:
  We describe classes of toric varieties of codimension 2 which are either
minimally defined by 3 binomial equations over any algebraically closed field,
or are set-theoretic complete intersections in exactly one positive
characteristic.


title:
Epitaxial thin films of multiferroic Bi2FeCrO6 with B-site cationic
  order

abstract:
  Epitaxial thin films of Bi2FeCrO6 have been synthesized by pulsed laser
deposition on SrRuO3 on (100)- and (111)-oriented SrTiO3 substrates. Detailed
X-ray diffraction and cross-section transmission electron microscopy analysis
revealed a double perovskite crystal structure of the Bi2FeCrO6 epitaxial films
very similar to that of BiFeO3 along with a particularly noteworthy Fe3+/Cr3+
cation ordering along the [111] direction. The films contain no detectable
magnetic iron oxide impurities and have the correct cationic average
stoichiometry throughout their thickness. They however exhibit a slight
modulation in the Fe and Cr compositions forming complementary stripe patterns,
suggesting minor local excess or depletion of Fe and Cr. The epitaxial BFCO
films exhibit good ferroelectric and piezoelectric properties, in addition to
magnetic properties at room temperature, as well as an unexpected
crystallographic orientation dependence of their room temperature magnetic
properties. Our results qualitatively confirm the predictions made using the
ab-initio calculations: the double-perovskite structure of Bi2FeCrO6 films
exhibit a Fe3+/Cr3+ cation ordering and good multiferroic properties, along
with the unpredicted existence of magnetic ordering at room temperature.


title: Spontaneous ferromagnetic spin ordering at the surface of La$_2$CuO$_4$

abstract:
  Magnetic properties of high purity stoichiometric La$_2$CuO$_4$ nanoparticles
are systematically investigated as a function of particle size. Ferromagnetic
single-domain spin clusters are shown to spontaneously form at the surface of
fine grains as well as paramagnetic defects. Hysteresis loops and
thermomagnetic irreversibility are observed in a wide temperature range $5 -
350$ K with the remnant moment and coercivity gradually decreasing with
increasing temperature. Possible origins of the spontaneous surface
ferromagnetic clusters and the relation of our data to the appearance of
unusual magnetic phenomena and phase separation of doped cuprates are
discussed.


title: Finite-Mass Effects on Inclusive B-Meson Hadroproduction

abstract:
  We calculate the transverse-momentum (p_T) distribution for the inclusive
hadroproduction of B mesons at intermediate values of p_T at next-to-leading
order (NLO) in a dedicated finite-mass scheme using realistic non-perturbative
fragmentation functions that are obtained through a global fit to e^+e^- data
from CERN LEP1 and SLAC SLC exploiting their universality and scaling
violations. We find that finite-mass effects moderately enhance the cross
section, by about 20% at p_T = 2 m_b, and rapidly fade out with increasing
value of p_T, so that the zero-mass prediction is reached. We also perform
comparisons with recent ppbar data taken by the CDF Collaboration in run II at
the Fermilab Tevatron and comment on the usefulness of the fixed-flavor-number
scheme.


title:
Semiclassical scalar propagators in curved backgrounds: formalism and
  ambiguities

abstract:
  The phenomenology of quantum systems in curved space-times is among the most
fascinating fields of physics, allowing --often at the gedankenexperiment
level-- constraints on tentative theories of quantum gravity. Determining the
dynamics of fields in curved backgrounds remains however a complicated task
because of the highly intricate partial differential equations involved,
especially when the space metric exhibits no symmetry. In this article, we
provide --in a pedagogical way-- a general formalism to determine this dynamics
at the semiclassical order. To this purpose, a generic expression for the
semiclassical propagator is computed and the equation of motion for the
probability four-current is derived. Those results underline a direct analogy
between the computation of the propagator in general relativistic quantum
mechanics and the computation of the propagator for stationary systems in
non-relativistic quantum mechanics. A possible application of this formalism to
curvature-induced quantum interferences is also discussed.


title: An On-Demand Coherent Single Electron Source

abstract:
  We report on the electron analog of the single photon gun. On demand single
electron injection in a quantum conductor was obtained using a quantum dot
connected to the conductor via a tunnel barrier. Electron emission is triggered
by application of a potential step which compensates the dot charging energy.
Depending on the barrier transparency the quantum emission time ranges from 0.1
to 10 nanoseconds. The single electron source should prove useful for the
implementation of quantum bits in ballistic conductors. Additionally periodic
sequences of single electron emission and absorption generate a quantized
AC-current.


title:
Ab initio correlation effects on the electronic and transport properties
  of metal(II)-phthalocyanine based devices

abstract:
  Using first principles calculations in the framework of Density Functional
Theory, we investigated the electronic and transport properties of
metal(II)-phthalocyanine (M(II)Pc) systems, both in a single molecule
configuration and in a model-device geometry. In particular, using the
Copper(II)- and Manganese(II)-Pc as prototypical examples, we studied how
electronic correlations on the central metal-ion influence the analysis of the
electronic structure of the system and we demonstrated that the choice of the
exchange-correlation functional, also beyond the standard local or gradient
corrected level, is of crucial importance for a correct interpretation of the
data. Finally, our electronic transport simulations have shown that
M(II)Pc-based devices can act selectively as molecular conductors, as in the
case of Copper, or as spin valves, as in the case of Manganese, demonstrating
once more the great potential of these systems for molecular nanoelectronics
applications.


title: Report of the US long baseline neutrino experiment study

abstract:
  This report provides the results of an extensive and important study of the
potential for a U.S. scientific program that will extend our knowledge of
neutrino oscillations well beyond what can be anticipated from ongoing and
planned experiments worldwide. The program examined here has the potential to
provide the U.S. particle physics community with world leading experimental
capability in this intensely interesting and active field of fundamental
research. Furthermore, this capability could be unique compared to anywhere
else in the world because of the available beam intensity and baseline
distances. The present study was initially commissioned in April 2006 by top
research officers of Brookhaven National Laboratory and Fermi National
Accelerator Laboratory and, as the study evolved, it also provided responses to
questions formulated and addressed to the study group by the Neutrino
Scientific Advisory Committee (NuSAG) of the U.S. DOE and NSF. The participants
in the study, its Charge and history, plus the study results and conclusions
are provided in this report and its appendices. A summary of the conclusions is
provided in the Executive Summary.


title: Relativistic cosmology and large-scale structure

abstract:
  General relativity marked the beginning of modern cosmology and it has since
been at the centre of many of the key developments in this field. In the
present review, we discuss the general-relativistic dynamics and perturbations
of the standard cosmological model, the Friedmann-Lemaitre universe, and how
these can explain and predict the properties of the observable universe. Our
aim is to provide an overview of the progress made in several major research
areas, such as linear and non-linear cosmological perturbations, large-scale
structure formation and the physics of the cosmic microwave background
radiation, in view of current and upcoming observations. We do this by using a
single formalism throughout the review, the 1+3 covariant approach to
cosmology, which allows for a uniform and balanced presentation of technical
information and physical insight.


title: The Dark Side of a Patchwork Universe

abstract:
  While observational cosmology has recently progressed fast, it revealed a
serious dilemma called dark energy: an unknown source of exotic energy with
negative pressure driving a current accelerating phase of the universe. All
attempts so far to find a convincing theoretical explanation have failed, so
that one of the last hopes is the yet to be developed quantum theory of
gravity. In this article, loop quantum gravity is considered as a candidate,
with an emphasis on properties which might play a role for the dark energy
problem. Its basic feature is the discrete structure of space, often associated
with quantum theories of gravity on general grounds. This gives rise to
well-defined matter Hamiltonian operators and thus sheds light on conceptual
questions related to the cosmological constant problem. It also implies typical
quantum geometry effects which, from a more phenomenological point of view, may
result in dark energy. In particular the latter scenario allows several
non-trivial tests which can be made more precise by detailed observations in
combination with a quantitative study of numerical quantum gravity. If the
speculative possibility of a loop quantum gravitational origin of dark energy
turns out to be realized, a program as outlined here will help to hammer out
our ideas for a quantum theory of gravity, and at the same time allow
predictions for the distant future of our universe.


title:
Spitzer-IRAC GLIMPSE of high mass protostellar objects. I Infrared point
  sources and nebulae

abstract:
  The GLIMPSE archive was used to obtain 3.6--8.0micron, point source
photometry and images for 381 massive protostellar candidates lying in the
Galactic mid-plane. The colours, magnitudes and spectral indicies of sources in
each of the 381 target fields were analysed and compared with the predictions
of 2D radiative transfer model simulations. Although no discernable embedded
clusters were found in any targets, multiple sources or associations of
redenned young stellar objects were found in many sources indicating
multiplicity at birth. The spectral index ($\alpha$) of these point sources in
3.6--8.0mum bands display large values of $\alpha$=2--5. A color-magnitude
analog plot was used to identify 79 infrared counterparts to the HMPOs. Compact
nebulae are found in 75% of the detected sources with morphologies that can be
well described by core-halo, cometary, shell-like and bipolar geometries
similar to those observed in ultra-compact HII regions. The IRAC band SEDs of
the IR counterparts of HMPOs are best described to represent YSOs with a mass
range of 8--20\msun in their Class I stages when compared with 2D radiative
transfer models. They also suggest that the high $\alpha$ values represent
reprocessed star/star+disk emission that is arising in the dense envelopes.
Thus we are witnessing the luminous envelopes around the protostars rather than
their photospheres or disks. We argue that the compact infrared nebulae likely
reflect the underlying physical structure of the dense cores and are found to
imitate the morphologies of known UCHII regions. Our results favour models of
continuuing accretion involving both molecular and ionised accretion components
to build the most massive stars rather than purely molecular rapid accretion
flows.


title: About the lifetime of a bouncing droplet

abstract:
  When a droplet is gently laid onto the surface of the same liquid, it stays
at rest for a moment before coalescence. The coalescence can be delayed and
sometimes inhibited by injecting fresh air under the droplet. This can happen
when the surface of the bath oscillates vertically, in this case the droplet
basically bounces on the interface. The lifetime of the droplet has been
studied with respect to the amplitude and the frequency of the excitation. The
lifetime decreases when the acceleration increases. The thickness of the air
film between the droplet and the bath has been investigated using interference
fringes obtained when the system is illuminated by low pressure sodium lamps.
Moreover, both the shape evolution and the motion of the droplet center of mass
have been recorded in order to evidence the phase offset between the
deformation and the trajectory. A short lifetime is correlated to a small air
film thickness and to a large phase offset between the maximum of deformation
and the minimum of the vertical position of the centre of mass.


title: Are Gamma-Ray Bursts Standard Candles?

abstract:
  By dividing a sample of 48 long-duration gamma-ray bursts (GRBs) into four
groups with redshift from low to high and fitting each group with the Amati
relation log Eiso = a + b log Epeak, I find that parameters a and b vary with
the mean redshift of the GRBs in each group systematically and significantly.
The results suggest that GRBs evolve strongly with the cosmic redshift and
hence are not standard candles.


title:
What the Infrared Behaviour of QCD Vertex Functions in Landau gauge can
  tell us about Confinement

abstract:
  The infrared behaviour of Landau gauge QCD vertex functions is investigated
employing a skeleton expansion of the Dyson-Schwinger and Renormalization Group
equations. Results for the ghost-gluon, three-gluon, four-gluon and quark-gluon
vertex functions are presented. Positivity violation of the gluon propagator,
and thus gluon confinement, is demonstrated. Results of the Dyson-Schwinger
equations for a finite volume are compared to corresponding lattice data. It is
analytically demonstrated that a linear rising potential between heavy quarks
can be generated by infrared singularities in the dressed quark-gluon vertex.
The selfconsistent mechanism that generates these singularities necessarily
entails the scalar Dirac amplitudes of the full vertex and the quark
propagator. These can only be present when chiral symmetry is broken, either
explicitly or dynamically.


title:
Neutral Hydrogen Absorption Toward XTE J1810-197: the Distance to a
  Radio-Emitting Magnetar

abstract:
  We have used the Green Bank Telescope to measure HI absorption against the
anomalous X-ray pulsar XTE J1810-197. Assuming a flat rotation curve, we find
that XTE J1810-197 is located at a distance of 3.4(+0.5,-0.7) kpc. For a
rotation curve that incorporates a model of the Galactic bar, we obtain a
distance of 4.0(+0.3,-0.8) kpc. Using a rotation curve that incorporates a
model of the Galactic bar and the spiral arms of the Galaxy, the distance is
3.7(+/-0.6) kpc. These values are consistent with the distance to XTE J1810-197
of about 3.3 kpc derived from its dispersion measure, and estimates of 2-5 kpc
obtained from fits to its X-ray spectra. Overall, we determine that XTE
J1810-197 is located at a distance of 3.5(+/-0.5) kpc, possibly not far in
front of the infrared dark cloud G10.74-0.13. We also used the GBT in an
attempt to measure absorption in the OH 1612, 1665, 1667, and 1720 MHz lines
against XTE J1810-197. We were unsuccessful in this, mainly because of its
declining radio flux density. Analysis of HI 21 cm, OH, and CO(2-1) emission
toward XTE J1810-197 allows us to place a lower limit of $N_{\rm H} \ga 4.6
\times 10^{21}$ cm$^{-2}$ on the non-ionized hydrogen column density to
\magnetar, consistent with estimates obtained from fits to its X-ray spectra.


title:
On the Sensitivity of Massive Star Nucleosynthesis and Evolution to
  Solar Abundances and to Uncertainties in Helium Burning Reaction Rates

abstract:
  We explore the dependence of pre-supernova evolution and supernova
nucleosynthesis yields on the uncertainties in helium burning reaction rates.
Using the revised solar abundances of Lodders (2003) for the initial stellar
composition, instead of those of Anders & Grevesse (1989), changes the
supernova yields and limits the constraints that those yields place on the
12C(a,g)16O reaction rate. The production factors of medium-weight elements (A
= 16-40) were found to be in reasonable agreement with observed solar ratios
within the current experimental uncertainties in the triple alpha reaction
rate. Simultaneous variations by the same amount in both reaction rates or in
either of them separately, however, can induce significant changes in the
central 12C abundance at core carbon ignition and in the mass of the supernova
remnant. It therefore remains important to have experimental determinations of
the helium burning rates so that their ratio and absolute values are known with
an accuracy of 10% or better.


title:
Hamiltonian and Brownian systems with long-range interactions: III. The
  BBGKY hierarchy for spatially inhomogeneous systems

abstract:
  We study the growth of correlations in systems with weak long-range
interactions. Starting from the BBGKY hierarchy, we determine the evolution of
the two-body correlation function by using an expansion of the solutions of the
hierarchy in powers of 1/N in a proper thermodynamic limit $N\to +\infty$.
These correlations are responsible for the ``collisional'' evolution of the
system beyond the Vlasov regime due to finite $N$ effects. We obtain a general
kinetic equation that can be applied to spatially inhomogeneous systems and
that takes into account memory effects. These peculiarities are specific to
systems with unshielded long-range interactions. For spatially homogeneous
systems with short memory time like plasmas, we recover the classical Landau
(or Lenard-Balescu) equations. An interest of our approach is to develop a
formalism that remains in physical space (instead of Fourier space) and that
can deal with spatially inhomogeneous systems. This enlightens the basic
physics and provides novel kinetic equations with a clear physical
interpretation. However, unless we restrict ourselves to spatially homogeneous
systems, closed kinetic equations can be obtained only if we ignore some
collective effects between particles. General exact coupled equations taking
into account collective effects are also given. We use this kinetic theory to
discuss the processes of violent collisionless relaxation and slow collisional
relaxation in systems with weak long-range interactions. In particular, we
investigate the dependence of the relaxation time with the system size and
provide a coherent discussion of all the numerical results obtained for these
systems.


title: Infinitesimal cubical structure, and higher connections

abstract:
  In the context of Synthetic Differential Geometry, we describe a notion of
higher connection with values in a cubical groupoid. We do this by exploiting a
certain structure of cubical complex derived from the first neighbourhood of
the diagonal of a manifold. This cubical complex consists of infinitesimal
parallelelpipeda.


title: Hadronic unquenching effects in the quark propagator

abstract:
  We investigate hadronic unquenching effects in light quarks and mesons.
Within the non-perturbative continuum framework of Schwinger-Dyson and
Bethe-Salpeter equations we quantify the strength of the back reaction of the
pion onto the quark-gluon interaction. To this end we add a Yang-Mills part of
the interaction such that unquenched lattice results for various current quark
masses are reproduced. We find considerable effects in the quark mass function
at low momenta as well as for the chiral condensate. The quark wave function is
less affected. The Gell--Mann-Oakes-Renner relation is valid to good accuracy
up to pion masses of 400-500 MeV. As a byproduct of our investigation we verify
the Coleman theorem, that chiral symmetry cannot be broken spontaneously when
QCD is reduced to 1+1 dimensions.


title: Charged kaon lifetime at KLOE

abstract:
  Preliminary result on the charged kaon lifetime, obtained by the KLOE
experiment operating at DA$\Phi$NE, the Frascati $\phi$-factory, is presented


title: Exploring holographic dark energy model with Sandage-Loeb test

abstract:
  Taking into account that Sandage-Loeb test is unique in its coverage of the
redshift desert and available in the near future, we explore the cosmic time
evolution behavior of the source redshift for holographic dark energy model, an
important competing cosmological model. As a result, we find that Sandage-Loeb
test can provide a extremely strong bound on $\Omega^0_m$, while its constraint
on another dimensionless parameter $\lambda$ is weak. In addition, it is
proposed here for the first time that we can also constrain various
cosmological model by measuring the value of $z_{max}$ at which the peak of
redshift velocity occurs. Combining this new proposed method with the
traditional Sandage-Loeb test, we should be able to provide a better constraint
on $\lambda$, at least from the theoretical perspective.


title:
Direct diameter measurement of a star filling its Roche Lobe: The
  semi-detached binary SS Leporis spatially resolved with VINCI/VLTI

abstract:
  Stellar evolution in close binary systems is strongly influenced by mass
transfer from one star to the other when one component fills its zero-velocity
surface or Roche Lobe. SS Lep is a fairly nearby close binary showing the Algol
paradox and a shell spectrum, both indicative of (past) mass transfer. To study
the process of mass transfer and its evolutionary consequences, we aim at a
direct characterisation of the spatial dimensions of the different components
of SS Lep with IR interferometry. We use VINCI/VLTI interferometric
observations in the K band and photometric observations from the UV to the
far-IR. The visibilities are interpreted with simple geometrical models and the
Spectral Energy Distribution (SED) is decomposed into the three main
components: A star, M star and dust shell/disk. From the SED, we find that the
main emitters in the K band are the M star and the circumstellar environment.
Both are spatially resolved with the VINCI observations, showing the excess to
be circumbinary and showing the M star to have a size equal to its Roche Lobe.
We conclude that we have, for the first time, directly resolved a star filling
its Roche Lobe. The resulting mass transfer is probably the cause of (1) the
circumbinary dust disk of which we see the hot inner region spatially resolved
in our observations, (2) the unusually high luminosity of the A star and (3)
the shell spectrum seen in the UV and optical spectra.


title:
A Plane-Symmetric Inhomogeneous Cosmological Model of Perfect Fluid
  Distribution with Electromagnetic Field I

abstract:
  A plane-symmetric inhomogeneous cosmological model of perfect fluid
distribution with electro-magnetic field is obtained. The source of the
magnetic field is due to an electric current produced along the z-axis.
$F_{12}$ is the non-vanishing component of electromagnetic field tensor. To get
a deterministic solution, we assume the free gravitational field is Petrov
type-II non-degenerate. The behaviour of the electro-magnetic field tensor
together with some physical aspects of the model are also discussed.


title:
Aid to Percutaneous Renal Access by Virtual Projection of the Ultrasound
  Puncture Tract onto Fluoroscopic Images

abstract:
  Background and Purpose: Percutaneous renal access in the context of
percutaneous nephrolithotomy (PCNL) is a difficult technique, requiring rapid
and precise access to a particular calix. We present a computerized system
designed to improve percutaneous renal access by projecting the ultrasound
puncture tract onto fluoroscopic images. Materials and Methods: The system
consists of a computer and a localizer allowing spatial localization of the
position of the various instruments. Without any human intervention, the
ultrasound nephrostomy tract is superimposed in real time onto fluoroscopic
images acquired in various views. Results: We tested our approach by laboratory
experiments on a phantom. Also, after approval by our institution's Ethics
Committee, we validated this technique in the operating room during PCNL in one
patient. Conclusion: Our system is reliable, and the absence of
image-processing procedures makes it robust. We have initiated a prospective
study to validate this technique both for PCNL specialists and as a learning
tool.


title: Entanglement in the 1D extended anisotropic Heisenberg model

abstract:
  We present a study of entanglement in the case of the 1D extended anisotropic
Heisenberg model. We investigate two quantum phase transitions (QPTs) within
the previously found ergodicity phase diagram [E. Plekhanov, A. Avella, and F.
Mancini Phys. Rev. B \textbf{74}, 115120 (2006)]. Our calculations are done by
means of the numerically exact Lanczos method at T=0, followed by a finite-size
scaling. As a measure of entanglement we use the concurrence for two spins out
of the system. We conclude from our studies that these QPTs are accompanied by
a qualitative entanglement change.


title: SYM N=4 in light-cone gauge and the "bridge" identities

abstract:
  The light-cone gauge allows to single out a set of ``transverse'' fields
(TF), whose Green functions are free from UV divergences in SYM N=4. Green
functions with external lines involving the remaining fields do instead exhibit
divergences: indeed those fields can be expressed, by solving their equations
of motion, as composite operators in terms of ``transverse'' fields. A set of
exact identities (bridge identities) automatically realize their insertions in
a path-integral formulation.


title:
PERCEVAL: a Computer-Driven System for Experimentation on Auditory and
  Visual Perception

abstract:
  Since perception tests are highly time-consuming, there is a need to automate
as many operations as possible, such as stimulus generation, procedure control,
perception testing, and data analysis. The computer-driven system we are
presenting here meets these objectives. To achieve large flexibility, the tests
are controlled by scripts. The system's core software resembles that of a
lexical-syntactic analyzer, which reads and interprets script files sent to it.
The execution sequence (trial) is modified in accordance with the commands and
data received. This type of operation provides a great deal of flexibility and
supports a wide variety of tests such as auditory-lexical decision making,
phoneme monitoring, gating, phonetic categorization, word identification, voice
quality, etc. To achieve good performance, we were careful about timing
accuracy, which is the greatest problem in computerized perception tests.


title: Physical Aspects of Cancer Invasion

abstract:
  Invasiveness, one of the hallmarks of tumor progression, represents the
tumor's ability to expand into the host tissue by means of several complex
biochemical and biomechanical processes. Since certain aspects of the problem
present a striking resemblance with well known physical mechanisms, such as the
mechanical insertion of a solid inclusion in an elastic material specimen [1,
2] or a water drop impinging on a surface [3], we propose here an analogy
between these physical processes and a cancer system's invasive branching into
the surrounding tissue. Accounting for its solid and viscous properties, we
present a unifying concept that the tumor behaves as a granular solid. While
our model has been explicitly formulated for multicellular tumor spheroids in
vitro, it should also contribute to a better understanding of tumor invasion in
vivo.


title:
Stretched exponential relaxation and ac universality in disordered
  dielectrics

abstract:
  This paper is concerned with the connection between the properties of
dielectric relaxation and ac (alternating-current) conduction in disordered
dielectrics. The discussion is divided between the classical linear-response
theory and a self-consistent dynamical modeling. The key issues are, stretched
exponential character of dielectric relaxation, power-law power spectral
density, and anomalous dependence of ac conduction coefficient on frequency. We
propose a self-consistent model of dielectric relaxation, in which the
relaxations are described by a stretched exponential decay function.
Mathematically, our study refers to the expanding area of fractional calculus
and we propose a systematic derivation of the fractional relaxation and
fractional diffusion equations from the property of ac universality.


title:
Formation of Quark Phases in compact stars and their connection to
  Gamma-Ray-Bursts

abstract:
  We analyse the occurrence of quiescent times in the temporal structure of the
Gamma-Ray-Bursts (GRBs) light curves. We show that if a long quiescent time is
present, it is possible to divide the total duration of GRBs into three
periods: the pre-quiescence emission, the quiescent time and the
post-quiescence emission. We then discuss a model of the GRBs inner engine
based on the formation of quark phases during the life of an hadronic star.
Within this model the pre-quiescence emission is interpreted as due to the
deconfinement of quark inside an hadronic star and the formation of 2SC quark
matter. The post-quiescence emission is due to the conversion of 2SC into the
Color-Flavor-Locking (CFL) phase. The temporal delay between these two
processes is connected with the nucleation time of the CFL phase in the 2SC
phase and it can be associated with the observed quiescent times in the GRBs
light curves. The stability of CFL cores in compact stars is also discussed.


title:
Predictive Model of Inverted Neutrino Mass Hierarchy and Resonant
  Leptogenesis

abstract:
  We present a new realization of inverted neutrino mass hierarchy based on
$S_3 \times {\cal U}(1)$ flavor symmetry. In this scenario, the deviation of
the solar oscillation angle from $\pi/4$ is correlated with the value of
$\theta_{13}$, as they are both induced by a common mixing angle in the charged
lepton sector. We find several interesting predictions: $\te_{13}\geq 0.13$,
$\sin^2\te_{12}\geq 0.31$, $\sin^2\te_{23}\simeq 0.5$ and $0\leq \cos \de \leq
0.7$ for the neutrino oscillation parameters and $0.01 {\rm
eV}\stackrel{<}{_\sim}m_{\bt \bt}\stackrel{<}{_\sim} 0.02 {\rm eV}$ for the
effective neutrino mass in neutrino-less double $\bt $-decay. We show that our
scenario can also explain naturally the observed baryon asymmetry of the
universe via resonant leptogenesis. The masses of the decaying right--handed
neutrinos can be in the range $(10^3 - 10^7)$ GeV, which would avoid the
generic gravitino problem of supersymmetric models.


title:
Non equilibrium velocity distributions of H- ions in H2 plasmas and
  photodetachment measurements

abstract:
  A theoretical study of the energy distribution function of the negative
hydrogen ion H- in typical conditions for multicusp ion sources is presented.
The case of H/H2 mixture is studied by a Monte Carlo solution of the kinetic
equation for H- transport. A simple analytical model is obtained for the case
of a fully dissociated H plasma and uniform reduced electric field (E/N).
Results are in good agreement with the two-group distribution deduced from
laser photodetachment experiments and explain the low energy group as an effect
of the charge exchange collisions of negative ions with H atoms.


title:
Exploring CP Violation and Penguin Effects through $B^0_d \to D^+ D^-$
  and $B^0_s \to D^+_s D^-_s$

abstract:
  The decay $B^0_d \to D^+ D^-$ offers an interesting probe of CP violation,
but requires control of penguin effects, which can be done through $B^0_s \to
D^+_s D^-_s$ by means of the $U$-spin flavour symmetry of strong interactions.
Recently, the Belle collaboration reported indications of large CP violation in
the $B^0_d$ decay, which were, however, not confirmed by BaBar, and first
signals of the $B^0_s$ channel were observed at the Tevatron. In view of these
developments and the quickly approaching start of the LHC, we explore the
allowed region in observable space for CP violation in $B^0_d \to D^+ D^-$,
perform theoretical estimates of the relevant hadronic penguin parameters and
observables, and address questions both about the most promising strategies for
the extraction of CP-violating phases and about the interplay with other
measurements of CP violation and the search for new physics. As far as the
latter aspect is concerned, we point out that the $B^0_{q} \to D_{q}^+ D^-_{q}$
system provides a setting for the determination of the $B^0_q$-$\bar B^0_q$
mixing phases ($q\in\{d,s\}$) that is complementary to the conventional
$B^0_d\to J/\psi K_S$ and $B^0_s\to J/\psi \phi$ modes with respect to possible
new-physics effects in the electroweak penguin sector.


title:
Evidence for nonlinear diffusive shock acceleration of cosmic-rays in
  the 2006 outburst of the recurrent nova RS Ophiuchi

abstract:
  Spectroscopic observations of the 2006 outburst of the recurrent nova RS
Ophiuchi at both infrared (IR) and X-ray wavelengths have shown that the blast
wave has decelerated at a higher rate than predicted by the standard
test-particle adiabatic shock-wave model. Here we show that the observed
evolution of the nova remnant can be explained by the diffusive shock
acceleration of particles at the blast wave and the subsequent escape of the
highest energy ions from the shock region. Nonlinear particle acceleration can
also account for the difference of shock velocities deduced from the IR and
X-ray data. The maximum energy that accelerated electrons and protons can have
achieved in few days after outburst is found to be as high as a few TeV. Using
the semi-analytic model of nonlinear diffusive shock acceleration developed by
Berezhko & Ellison, we show that the postshock temperature of the shocked gas
measured with RXTE/PCA and Swift/XRT imply a relatively moderate acceleration
efficiency.


title: Algebraic K-Theory and Partition Functions in Conformal Field Theory

abstract:
  Certain integrable models are described by pairs (X,Y) of ADET Dynkin
diagrams. At high energy these models are expected to have a conformally
invariant limit. The S-matrix of the model determines algebraic equations,
whose solutions are mapped to the central charge and scaling dimensions of the
corresponding conformal field theory. We study the equations of the (D_m,A_n)
model and find all solutions explicitly using the representation theory of Lie
algebras and related Yangians. These mathematically rigorous results are in
agreement with the expectations arising from physics. We also investigate the
overlap between certain q-hypergeometric series and modular functions. We study
a particular class of 2-fold q-hypergeometric series, denoted f_{A,B,C}. Here A
is a positive definite, symmetric, 2x2 matrix, B is a vector of length 2, and C
is a scalar, all three with rational entries. It turns out that for certain
choices of the matrix A, the function f_{A,B,C} can be made modular. We
calculate the corresponding values of B and C. It is expected that functions
f_{A,B,C} arising in this way are characters of some rational conformal field
theory. We show that this is true in at least one case.


title:
Magnetic fluctuations in n-type high-$T_c$ superconductors reveal
  breakdown of fermiology

abstract:
  By combining experimental measurements of the quasiparticle and dynamical
magnetic properties of optimally electron-doped Pr$_{0.88}$LaCe$_{0.12}$CuO$_4$
with theoretical calculations we demonstrate that the conventional fermiology
approach cannot possibly account for the magnetic fluctuations in these
materials. In particular, we perform tunneling experiments on the very same
sample for which a dynamical magnetic resonance has been reported recently and
use photoemission data by others on a similar sample to characterize the
fermionic quasiparticle excitations in great detail. We subsequently use this
information to calculate the magnetic response within the conventional
fermiology framework as applied in a large body of work for the hole-doped
superconductors to find a profound disagreement between the theoretical
expectations and the measurements: this approach predicts a step-like feature
rather than a sharp resonance peak, it underestimates the intensity of the
resonance by an order of magnitude, it suggests an unreasonable temperature
dependence of the resonance, and most severely, it predicts that most of the
spectral weight resides in incommensurate wings which are a key feature of the
hole-doped cuprates but have never been observed in the electron-doped
counterparts. Our findings strongly suggest that the magnetic fluctuations
reflect the quantum-mechanical competition between antiferromagnetic and
superconducting orders.


title: High-precision study of Cs polarizabilities

abstract:
  We present results of the first-principles calculation of Cs dipole static
polarizabilities for the Ns (N = 6 - 12), Np_j (N = 6 - 10), and Nd_j (N = 5 -
10) states using the relativistic all-order method. In our implementation of
the all-order method, single and double excitations of Dirac-Fock wave
functions are included to all orders in perturbation theory. Additional
calculations are carried out for the dominant terms and the uncertainties of
our final values are estimated for all states. A comprehensive review of the
existing theoretical and experimental studies of the Cs polarizabilities is
also carried out. Our results are compared with other values where they are
available. These calculations provide a theoretical benchmark for a large
number of Cs polarizabilities.


title: Dynamics of Logamediate Inflation

abstract:
  A computation of the inflationary observables n_{s} and r is made for
`logamediate' inflation where the cosmological scale factor expands as $a=\exp
(A(\ln t)^{\lambda})$, and is compared to their predicted values in the
intermediate inflationary theory, where $a=\exp (Bt^{f})$. Both versions prove
to be consistent with observational measurements of the cosmic background
radiation. It is shown that the dynamics of a single inflaton field can be
mimicked by a system of several fields in an analogous manner to that created
by the joint evolution of the fields in assisted power-law inflation.


title: Simulation of Demographic Change in Palestinian Territories

abstract:
  Mortality, birth rates and retirement play a major role in demographic
changes. In most cases, mortality rates decreased in the past century without
noticeable decrease in fertility rates, this leads to a significant increase in
population growth. In many poor countries like Palestinian territories the
number of births has fallen and the life expectancy increased.
  In this article we concentrate on measuring, analyzing and extrapolating the
age structure in Palestine a few decades ago into future. A Fortran program has
been designed and used for the simulation and analysis of our statistical data.
This study of demographic change in Palestine has shown that Palestinians will
have in future problems as the strongest age cohorts are the above-60-year
olds. We therefore recommend the increase of both the retirement age and women
employment.


title:
Electron electric dipole moment experiment using electric-field
  quantized slow cesium atoms

abstract:
  A proof-of-principle electron electric dipole moment (e-EDM) experiment using
slow cesium atoms, nulled magnetic fields, and electric field quantization has
been performed. With the ambient magnetic fields seen by the atoms reduced to
less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between
states of unequal mF and, along with the low (approximately 3 m/s) velocity,
suppresses the systematic effect from the motional magnetic field. The low
velocity and small residual magnetic field have made it possible to induce
transitions between states and to perform state preparation, analysis, and
detection in regions free of applied static magnetic and electric fields. This
experiment demonstrates techniques that may be used to improve the e-EDM limit
by two orders of magnitude, but it is not in itself a sensitive e-EDM search,
mostly due to limitations of the laser system.


title:
A successive sub-grouping method for multiple sequence alignments
  analysis

abstract:
  A novel approach to protein multiple sequence alignment is discussed:
substantially this method counterparts with substitution matrix based methods
(like Blosum or PAM based methods), and implies a more deterministic approach
to chemical/physical sub-grouping of amino acids . Amino acids (aa) are divided
into sub-groups with successive derivations, that result in a clustering based
on the considered property. The properties can be user defined or chosen
between default schemes, like those used in the analysis described here.
Starting from an initial set of the 20 naturally occurring amino acids, they
are successively divided on the basis of their polarity/hydrophobic index, with
increasing resolution up to four level of subdivision. Other schemes of
subdivision are possible: in this thesis work it was employed also a scheme
based on physical/structural properties (solvent exposure, lateral chain
mobility and secondary structure tendency), that have been compared to the
chemical scheme with testing purposes. In the method described in this chapter,
the total score for each position in the alignment accounts for different
degree of similarity between amino acids. The scoring value result form the
contribution of each level of selectivity for every individual property
considered. Simply the method (called M_Al) analyse the n sequence alignment
position per position and assigns a score which have contributes by aa identity
plus a composed valuation of the chemical or of the structural affinity between
the n aligned amino acids. This method has been implemented in a series of
programs written in python language; these programs have been tested in some
biological cases, with benchmark purposes.


title: Structure and Dynamics of the Sun's Open Magnetic Field

abstract:
  The solar magnetic field is the primary agent that drives solar activity and
couples the Sun to the Heliosphere. Although the details of this coupling
depend on the quantitative properties of the field, many important aspects of
the corona - solar wind connection can be understood by considering only the
general topological properties of those regions on the Sun where the field
extends from the photosphere out to interplanetary space, the so-called open
field regions that are usually observed as coronal holes. From the simple
assumptions that underlie the standard quasi-steady corona-wind theoretical
models, and that are likely to hold for the Sun, as well, we derive two
conjectures on the possible structure and dynamics of coronal holes: (1)
Coronal holes are unique in that every unipolar region on the photosphere can
contain at most one coronal hole. (2) Coronal holes of nested polarity regions
must themselves be nested. Magnetic reconnection plays the central role in
enforcing these constraints on the field topology. From these conjectures we
derive additional properties for the topology of open field regions, and
propose several observational predictions for both the slowly varying and
transient corona/solar wind.


title: Quantum geometry and gravitational entropy

abstract:
  Most quantum states have wavefunctions that are widely spread over the
accessible Hilbert space and hence do not have a good description in terms of a
single classical geometry. In order to understand when geometric descriptions
are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of
asymptotically AdS_5 x S^5 universes. In this sector we devise a
"coarse-grained metric operator" whose eigenstates are well described by a
single spacetime topology and geometry. We show that such half-BPS universes
have a non-vanishing entropy if and only if the metric is singular, and that
the entropy arises from coarse-graining the geometry. Finally, we use our
entropy formula to find the most entropic spacetimes with fixed asymptotic
moments beyond the global charges.


title: On Shimura curves in the Schottky locus

abstract:
  We show that a given rational Shimura curve Y with strictly maximal Higgs
field in the moduli space of g-dimensional abelian varieties does not
generically intersect the Schottky locus for large g.
  We achieve this by using a result of Viehweg and Zuo which says that if Y
parameterizes a family of curves of genus g, then the corresponding family of
Jacobians is isogenous over Y to the g-fold product of a modular family of
elliptic curves. After reducing the situation from the field of complex numbers
to a finite field, we will see, combining the Weil and Sato-Tate conjectures,
that this is impossible for large genus g.


title: On the existence of supergravity duals to D1--D5 CFT states

abstract:
  We define a metric operator in the 1/2-BPS sector of the D1-D5 CFT, the
eigenstates of which have a good semi-classical supergravity dual; the
non-eigenstates cannot be mapped to semi-classical gravity duals. We also
analyse how the data defining a CFT state manifests itself in the gravity side,
and show that it is arranged into a set of multipoles. Interestingly, we find
that quantum mechanical interference in the CFT can have observable
manifestations in the semi-classical gravity dual. We also point out that the
multipoles associated to the normal statistical ensemble fluctuate wildly,
indicating that the mixed thermal state should not be associated to a
semi-classical geometry.


title: Accretion onto black holes and relativistic jets

abstract:
  Relativistic jets from Active Galactic Nuclei are known since decades, but
the study of the connection between accretion and ejection in these systems is
hampered by the long time scales associated to these events. The past decade
has seen a rapid advancement due to the observation of similar radio jets in
galactic X-ray binaries, where the time scales are much shorter. A clear
connection between accretion and ejection has been found for these systems,
together with a solid characterization of the phenomenological properties of
their outbursts. This wealth of new results has led to a detailed comparison
between X-ray binaries and AGN, from which a number of correlations and scaling
laws has been established. Here I briefly review the current observational
status.


title: Phase separation in a two-band model for strongly correlated electrons

abstract:
  The two-band Hubbard model is used to analyze a possibility of a non-uniform
charge distribution in a strongly correlated electron system with two types of
charge carriers. It is demonstrated that in the limit of strong on-site Coulomb
repulsion, such a system has a tendency to phase separation into the regions
with different charge densities even in the absence of magnetic or any other
ordering. This tendency is especially pronounced if the ratio of the bandwidths
is large enough. The characteristic size of inhomogeneities is estimated
accounting for the surface energy and the electrostatic energy related to the
charge imbalance.


title:
New non-local SUSY KdV conservation laws from a recursive gradient
  algorithm

abstract:
  A complete proof of the recursive gradient approach is presented. It gives a
construction of all the hierarchy structures of N=1 Super KdV, including the
non-local one. A precise definition of the ring of superfields involved in the
non-local construction is given. In particular, new non-local conserved
quantities of N=1 Super KdV are found.


title: On the Jacobi-Metric Stability Criterion

abstract:
  We investigate the exact relation existing between the stability equation for
the solutions of a mechanical system and the geodesic deviation equation of the
associated geodesic problem in the Jacobi metric constructed via the
Maupertuis-Jacobi Principle. We conclude that the dynamical and geometrical
approaches to the stability/instability problem are not equivalent.


title:
The origin of power-law distributions in deterministic walks: the
  influence of landscape geometry

abstract:
  We investigate the properties of a deterministic walk, whose locomotion rule
is always to travel to the nearest site. Initially the sites are randomly
distributed in a closed rectangular ($A/L \times L)$ landscape and, once
reached, they become unavailable for future visits. As expected, the walker
step lengths present characteristic scales in one ($L \to 0$) and two ($A/L
\sim L$) dimensions. However, we find scale invariance for an intermediate
geometry, when the landscape is a thin strip-like region. This result is
induced geometrically by a dynamical trapping mechanism, leading to a power law
distribution for the step lengths. The relevance of our findings in broader
contexts -- of both deterministic and random walks -- is also briefly
discussed.


title: Maximal lattice free bodies, test sets and the Frobenius problem

abstract:
  Maximal lattice free bodies are maximal polytopes without interior integral
points. Scarf initiated the study of maximal lattice free bodies relative to
the facet normals in a fixed matrix. In this paper we give an efficient
algorithm for computing the maximal lattice free bodies of an integral matrix
A. An important ingredient is a test set for a certain integer program
associated with A. This test set may be computed using algebraic methods. As an
application we generalize the Scarf-Shallcross algorithm for the
three-dimensional Frobenius problem to arbitrary dimension. In this context our
method is inspired by the novel algorithm by Einstein, Lichtblau, Strzebonski
and Wagon and the Groebner basis approach by Roune.


title:
Moduli spaces of critical Riemannian metrics with L^{n/2} norm curvature
  bounds

abstract:
  We consider the moduli space of the extremal K\"ahler metrics on compact
manifolds. We show that under the conditions of two-sided total volume bounds,
$L^{n\over2}$-norm bounds on $\Riem$, and Sobolev constant bounds, this Moduli
space can be compactified by including (reduced) orbifolds with finitely many
singularities. Most of our results go through for certain other classes of
critical Riemannian metrics.


title: Philosophy and Relativity

abstract:
  With his General Theory of Relativity, Albert Einstein produced a revolution
in our conception of reality and of the knowledge we can obtain from it. This
revolution can be viewed from philosophy as leading to one of the great
paradigms in the history of thought which, together with the Aristotelian and
the Newtonian paradigms, embodied the different ways of conceiving the universe
and our access to it. The comparison among these three paradigms allows us to
understand how the human being has progressively lost his central place in the
cosmos, not only in physical terms, but also in an epistemic sense, regarding
his power of knowledge about reality.


title: World-set Decompositions: Expressiveness and Efficient Algorithms

abstract:
  Uncertain information is commonplace in real-world data management scenarios.
The ability to represent large sets of possible instances (worlds) while
supporting efficient storage and processing is an important challenge in this
context. The recent formalism of world-set decompositions (WSDs) provides a
space-efficient representation for uncertain data that also supports scalable
processing. WSDs are complete for finite world-sets in that they can represent
any finite set of possible worlds. For possibly infinite world-sets, we show
that a natural generalization of WSDs precisely captures the expressive power
of c-tables. We then show that several important decision problems are
efficiently solvable on WSDs while they are NP-hard on c-tables. Finally, we
give a polynomial-time algorithm for factorizing WSDs, i.e. an efficient
algorithm for minimizing such representations.


title: Charmonium dynamics in Au+Au collisions at sqrt(S)=200 GeV

abstract:
  The formation and suppression dynamics of J/Psi, Chi_c and Psi-Prime mesons
is studied within the HSD transport approach for Au+Au reactions at the top
RHIC energy of sqrt(S)=200 GeV. Two prominent models, which have been discussed
for more than a decade, are incorporated, i.e. the 'hadronic comover absorption
and reformation' model as well as the 'QGP threshold' scenario, and compared to
available experimental data. Our studies demonstrate that both scenarios -
compatible with experimental observation at SPS energies - fail severely at
RHIC energies. This combined analysis - together with the underestimation of
charm elliptic flow - proves that the dynamics of c, c-bar quarks are dominated
by partonic interactions in the strong QGP (sQGP) and can neither be modeled by
'hadronic' interactions nor described appropriately by color screening alone.


title: Deformations of asymptotically cylindrical G_2 manifolds

abstract:
  We prove that for a 7-dimensional manifold M with cylindrical ends the moduli
space of exponentially asymptotically cylindrical torsion-free G_2 structures
is a smooth manifold (if non-empty), and study some of its local properties. We
also show that the holonomy of the induced metric of an exponentially
asymptotically cylindrical G_2 manifold M is exactly G_2 if and only if its
fundamental group is finite and neither M nor any double cover of M is
homeomorphic to a cylinder.


title: Quality functions in community detection

abstract:
  Community structure represents the local organization of complex networks and
the single most important feature to extract functional relationships between
nodes. In the last years, the problem of community detection has been
reformulated in terms of the optimization of a function, the Newman-Girvan
modularity, that is supposed to express the quality of the partitions of a
network into communities. Starting from a recent critical survey on modularity
optimization, pointing out the existence of a resolution limit that poses
severe limits to its applicability, we discuss the general issue of the use of
quality functions in community detection. Our main conclusion is that quality
functions are useful to compare partitions with the same number of modules,
whereas the comparison of partitions with different numbers of modules is not
straightforward and may lead to ambiguities.


title:
Einstein against quantum mechanics: randomness, ignorance and our
  ignorance about randomness

abstract:
  Albert Einstein made fundamental contributions to the development of quantum
mechanics. However, he was never satisfied with the quantum worldview. In fact,
during most of his life he attempted to find inconsistencies and paradoxes
within quantum mechanics. His famous quote "God does not play dice" shows how
disturbing was to Einstein one of the most important aspects of quantum
mechanics: non-determinism. In this paper we will present the basic concepts of
quantum mechanics, we will describe Einstein's attempts to destroy it and we
will discuss why we can nowadays state that, in this regard, Albert Einstein
was not right.


title: Many-body effects in the mesoscopic x-ray edge problem

abstract:
  Many-body phenomena, a key interest in the investigation of bulk solid state
systems, are studied here in the context of the x-ray edge problem for
mesoscopic systems. We investigate the many-body effects associated with the
sudden perturbation following the x-ray excitation of a core electron into the
conduction band. For small systems with dimensions at the nanoscale we find
considerable deviations from the well-understood metallic case where Anderson
orthogonality catastrophe and the Mahan-Nozieres-DeDominicis response cause
characteristic deviations of the photoabsorption cross section from the naive
expectation. Whereas the K-edge is typically rounded in metallic systems, we
find a slightly peaked K-edge in generic mesoscopic systems with
chaotic-coherent electron dynamics. Thus the behavior of the photoabsorption
cross section at threshold depends on the system size and is different for the
metallic and the mesoscopic case.


title: On partial polynomial interpolation

abstract:
  The Alexander-Hirschowitz theorem says that a general collection of $k$
double points in ${\bf P}^n$ imposes independent conditions on homogeneous
polynomials of degree $d$ with a well known list of exceptions. We generalize
this theorem to arbitrary zero-dimensional schemes contained in a general union
of double points. We work in the polynomial interpolation setting. In this
framework our main result says that the affine space of polynomials of degree
$\le d$ in $n$ variables, with assigned values of any number of general linear
combinations of first partial derivatives, has the expected dimension if $d\neq
2$ with only five exceptional cases. If $d=2$ the exceptional cases are fully
described.


title: Relic gravitons as the observable for Loop Quantum Cosmology

abstract:
  In this paper we investigate tensor modes of perturbations in the universe
governed by Loop Quantum Cosmology. We derive the equation for tensor modes and
investigate numerically effects of quantum corrections. This investigation
reveals that the region of super-adiabatic amplification of tensor modes is
smaller in comparison with the classical case. Neglecting quantum corrections
to the equation for tensor modes and holding underlying loop dynamics we study
analytically the creation of gravitons. We calculate the power spectrum of
tensor perturbations during the super-inflationary phase induced by Loop
Quantum Gravity. The main result obtained is the spectrum of gravitons,
produced in the transition from the quantum to classical regime of the
Universe. Obtained spectrum is characterized by a hard branch. The numerical
investigation shows the strong dependence of $\nu_{\text{max}}$ frequency with
respect to quantum numbers. The parameter
$\Omega_{\text{gw}}(\nu_{\text{max}})$ approaches even to $\sim 10^{-1}$ for
highest frequencies. We compare our results with recent constraints from the
Laser Interferometer Gravitational-wave Observatory (LIGO) and find that it is
possible to test the quantum effects in the early Universe.


title: Stokes-vector evolution in a weakly anisotropic inhomogeneous medium

abstract:
  Equation for evolution of the four-component Stokes vector in weakly
anisotropic and smoothly inhomogeneous media is derived on the basis of
quasi-isotropic approximation of the geometrical optics method, which provides
consequent asymptotic solution of Maxwell equations. Our equation generalizes
previous results, obtained for the normal propagation of electromagnetic waves
in stratified media. It is valid for curvilinear rays with torsion and is
capable to describe normal modes conversion in the inhomogeneous media.
Remarkably, evolution of the Stokes vector is described by the
Bargmann-Michel-Telegdi equation for relativistic spin precession, whereas the
equation for the three-component Stokes vector resembles the Landau-Lifshitz
equation for spin precession in ferromegnetic systems. General theory is
applied for analysis of polarization evolution in a magnetized plasma. We also
emphasize fundamental features of the non-Abelian polarization evolution in
anisotropic inhomogeneous media and illustrate them by simple examples.


title: Effect of surface roughness on rate-dependent slip in simple fluids

abstract:
  Molecular dynamics simulations are used to investigate the influence of
molecular-scale surface roughness on the slip behavior in thin liquid films.
The slip length increases almost linearly with the shear rate for atomically
smooth rigid walls and incommensurate structures of the liquid/solid interface.
The thermal fluctuations of the wall atoms lead to an effective surface
roughness, which makes the slip length weakly dependent on the shear rate. With
increasing the elastic stiffness of the wall, the surface roughness smoothes
out and the strong rate dependence is restored again. Both periodically and
randomly corrugated rigid surfaces reduce the slip length and its shear rate
dependence.


title: Absolute Stability Limit for Relativistic Charged Spheres

abstract:
  We find an exact solution for the stability limit of relativistic charged
spheres for the case of constant gravitational mass density and constant charge
density. We argue that this provides an absolute stability limit for any
relativistic charged sphere in which the gravitational mass density decreases
with radius and the charge density increases with radius. We then provide a
cruder absolute stability limit that applies to any charged sphere with a
spherically symmetric mass and charge distribution. We give numerical results
for all cases. In addition, we discuss the example of a neutral sphere
surrounded by a thin, charged shell.


title:
The inefficiency of the first-order Fermi process in UHECR production at
  relativistic shocks

abstract:
  The question of the origin of ultra-high-energy cosmic rays at relativistic
shock waves is discussed in the light of results of recent Monte Carlo studies
of the first-order Fermi particle acceleration (Niemiec & Ostrowski 2006,
Niemiec et al. 2006). The models of the turbulent magnetic field near the shock
considered in these simulations include realistic features of the perturbed
magnetic field structures at the shock, which allow us to study all the field
and particle motion characteristics that are important for cosmic-ray
acceleration. Our results show that turbulent conditions near the shock, that
are consistent with the shock jump conditions, lead to substantial
modifications of the acceleration process with respect to the simplified
models, that produce wide-range power-law energy distributions, often with the
"universal" spectral index. Relativistic shocks are essentially always
superluminal, and thus they preferentially generate steep particle spectra with
cutoffs well below the maximum scattering energy, often not exceeding the
energy of the compressed background plasma ions. Thus, cosmic-ray acceleration
to very high energies at relativistic shock waves is inefficient, and such
shocks are not expected to be the sources of ultra-high-energy particles.


title:
Two Modes of Magnetization Switching in a Simulated Iron Nanopillar in
  an Obliquely Oriented Field

abstract:
  Finite-temperature micromagnetics simulations are employed to study the
magnetization-switching dynamics driven by a field applied at an angle to the
long axis of an iron nanopillar. A bi-modal distribution in the switching times
is observed, and evidence for two competing modes of magnetization-switching
dynamics is presented. For the conditions studied here, temperature $T = 20$ K
and the reversal field 3160 Oe at an angle of 75$^\circ$ to the long axis,
approximately 70% of the switches involve unstable decay (no free-energy
barrier) and 30% involve metastable decay (a free-energy barrier is crossed).
The latter are indistinguishable from switches which are constrained to start
at a metastable free-energy minimum. Competition between unstable and
metastable decay could greatly complicate applications involving magnetization
switches near the coercive field.


title: Is Quantum Mechanics Incompatible with Newton's First Law

abstract:
  Quantum mechanics (QM) clearly violates Newton's First Law of Motion (NFLM)
in the quantum domain for one of the simplest problems, yielding an effect in a
force-free region much like the Aharonov-Bohm effect. In addition, there is an
incompatibility between the predictions of QM in the classical limit, and that
of classical mechanics (CM) with respect to NFLM. A general argument is made
that such a disparity may be found commonly for a wide variety of quantum
predictions in the classical limit. Alternatives to the Schrodinger equation
are considered that might avoid this problem. The meaning of the classical
limit is examined. Critical views regarding QM by Schrodinger, Bohm, Bell,
Clauser, and others are presented to provide a more complete perspective.


title: Submillimeter and Millimeter Masers

abstract:
  Despite theoretical predictions of the existence of many submillimeter
masers, and some pioneering observational discoveries over the past few
decades, these lines have remained relatively unstudied due to (i) challenges
associated with observing at shorter wavelength; and, (ii) lack of possibility
of high (< 14'' at 345 GHz) angular resolution observations. With the advent of
the SMA, the first submillimeter imaging array capable of sub-arcsecond
resolution, APEX, and the promise of ALMA, opportunities are opening for
performing new science with millimeter/submillmeter masers. In this talk, I
will review recent work in the field - including extragalactic water millimeter
masers, hydrogen recombination masers, submillimeter masers in star-forming
regions, and in the envelopes of evolved stars - and discuss prospects for the
future.


title:
Towards a Comprehensive Fueling-Controlled Theory on the Growth of
  Massive Black Holes and Host Spheroids

abstract:
  We study the relation between nuclear massive black holes and their host
spheroid gravitational potential. Using AMR numerical simulations, we analyze
how gas is transported in the nuclear (central kpc) regions of galaxies. We
study the gas fueling onto the inner accretion disk (sub-pc scale) and the star
formation in a massive nuclear disk like those generally found in
proto-spheroids (ULIRGs, SCUBA Galaxies). These sub-pc resolution simulation of
gas fueling that is mainly depleted by star formation naturally satisfy the
`M_BH - $M_virial' relation, with a scatter considerably less than the observed
one. We found a generalized version of Kennicutt-Schmidt Law for starbursts is
satisfied, in which the total gas depletion rate (dot{M}_gas = dot{M}_BH +
dot{M}_SF) is the one that scales as M_gas/t_orbital. We also found that the
`M_BH - sigma' relation is a byproduct of the `M_BH - M_virial' relation in the
fueling controlled scenario.


title: Radiative $b\to d$ Penguins

abstract:
  This article gives an overview of the recent searches and measurements of
$b\to d$ penguin transitions with the BaBar experiment. The branching fraction
of these decays in the Standard Model (SM) is expected to be a factor of 10 or
more lower than the corresponding $b\to s$ penguin transitions, but a deviation
from the SM prediction would be an equally striking sign of new physics. The
exclusive decay $B\to\pi\ell\ell$ is searched by BaBar with no excess over the
background found. The BaBar measurement of $B\to(\rho,\omega)\gamma$ provides
the first evidence of $B^+\to\rho^+\gamma$, is in good agreement with the
previous Belle results and provides a measurement of $|V_{td}/V_{ts}|$
independent of the one from $B_s$ mixing. No deviation from the SM is found.


title:
Magnetic turbulence production by streaming cosmic rays upstream of SNR
  shocks

abstract:
  We present preliminary results of Particle-In-Cell simulations of magnetic
turbulence production by isotropic cosmic-ray ions streaming upstream of
supernova remnant shocks. The studies aim at testing the MHD predictions by
Bell (2004, 2005) of a strong amplification of short-wavelength nonresonant
wave modes and at studying the subsequent evolution of the magnetic turbulence
and its backreaction on cosmic ray trajectories. The detailed knowledge of the
upstream turbulence properties is crucial to ascertain all aspects of the shock
acceleration process - the transport properties of cosmic rays, the shock
structure, thermal particle injection and heating processes. An amplification
of magnetic field would also facilitate the acceleration of particles beyond
the "knee" in the cosmic-ray spectrum. Our kinetic approach is particularly
suited to address the backreaction on the cosmic rays, and it allows us to test
Bell's prediction of the eventual formation of extended filamentary structure
in the cosmic-ray distribution and also to arrive at a reliable estimate of the
total saturation magnetic-field level. The parameters chosen for the
simulations are favorable for the rapid excitation of purely growing modes. We
confirm the generation of the turbulent magnetic field due to the drift of
cosmic-ray ions in the upstream plasma, but show that the growth rate of the
field perturbations is much slower than estimated using the MHD approach and
the amplitude of the turbulence saturates at about dB/B~1. The magnetic field
also remains below equipartition with the upstream plasma.


title: Strongly-resonant p-wave superfluids

abstract:
  We study theoretically a dilute gas of identical fermions interacting via a
p-wave resonance. We show that, depending on the microscopic physics, there are
two distinct regimes of p-wave resonant superfluids, which we term "weak" and
"strong". Although expected naively to form a BCS-BEC superfluid, a
strongly-resonant p-wave superfluid is in fact unstable towards the formation
of a gas of fermionic triplets. We examine this instability and estimate the
lifetime of the p-wave molecules due to the collisional relaxation into
triplets. We discuss consequences for the experimental achievement of p-wave
superfluids in both weakly- and strongly-resonant regimes.


title: Coulomb integrals for the SL(2,R) WZNW model

abstract:
  We review the Coulomb gas computation of three-point functions in the SL(2,R)
WZNW model and obtain explicit expressions for generic states. These amplitudes
have been computed in the past by this and other methods but the analytic
continuation in the number of screening charges required by the Coulomb gas
formalism had only been performed in particular cases. After showing that ghost
contributions to the correlators can be generally expressed in terms of Schur
polynomials we solve Aomoto integrals in the complex plane, a new set of
multiple integrals of Dotsenko-Fateev type. We then make use of monodromy
invariance to analytically continue the number of screening operators and prove
that this procedure gives results in complete agreement with the amplitudes
obtained from the bootstrap approach. We also compute a four-point function
involving a spectral flow operator and we verify that it leads to the one unit
spectral flow three-point function according to a prescription previously
proposed in the literature. In addition, we present an alternative method to
obtain spectral flow non-conserving n-point functions through well defined
operators and we prove that it reproduces the exact correlators for n=3.
Independence of the result on the insertion points of these operators suggests
that it is possible to violate winding number conservation modifying the
background charge.


title:
Two-parameter scaling of correlation functions near continuous phase
  transitions

abstract:
  We discuss the order parameter correlation function in the vicinity of
continuous phase transitions using a two-parameter scaling form G(k) = k_c^{-2}
g(k\xi,k/k_c), where k is the wave-vector, \xi is the correlation length, and
the interaction-dependent non-universal momentum scale k_c remains finite at
the critical fixed point. The correlation function describes the entire
critical regime and captures the classical to critical crossover. One-parameter
scaling is recovered only in the limit k/k_c->0. We present an approximate
calculation of g(x,y) for the Ising universality class using the functional
renormalization group.


title: Dynamics of domain walls in magnetic nanostrips

abstract:
  We express dynamics of domain walls in ferromagnetic nanowires in terms of
collective coordinates generalizing Thiele's steady-state results. For weak
external perturbations the dynamics is dominated by a few soft modes. The
general approach is illustrated on the example of a vortex wall relevant to
recent experiments with flat nanowires. A two-mode approximation gives a
quantitatively accurate description of both the steady viscous motion of the
wall in weak magnetic fields and its oscillatory behavior in moderately high
fields above the Walker breakdown.


title: Thermodynamics of carrier-mediated magnetism in semiconductors

abstract:
  We propose a model of carrier-mediated ferromagnetism in semiconductors that
accounts for the temperature dependence of the carriers. The model permits
analysis of the thermodynamic stability of competing magnetic states, opening
the door to the construction of magnetic phase diagrams. As an example we
analyze the stability of a possible reentrant ferromagnetic semiconductor, in
which increasing temperature leads to an increased carrier density, such that
the enhanced exchange coupling between magnetic impurities results in the onset
of ferromagnetism as temperature is raised.


title: Dynamics of a domain wall in a magnetic nanostrip: a toy model

abstract:
  In this report we demonstrate a simple model for the motion of a vortex
domain wall in a ferromagnetic strip of submicron width under the influence of
an external magnetic field. The model exhibits three distinct dynamical
regimes. In a viscous regime at low fields the wall moves rigidly with a
velocity proportional to the field. Above a critical field the motion becomes
underdamped as the vortex moves periodically across the strip; these
oscillations are accompanied by a slow drift with a decreasing velocity. At
still higher fields the drift velocity starts rising linearly with the field
again but with a much lower mobility dv/dH than in the low-field regime. We
calculate the relevant quantities and compare them to experimentally observed
values.


title:
A Model for Damage Spreading with Damage Healing: Monte Carlo Study of
  the two Dimensional Ising Ferromagnet

abstract:
  An Ising model for damage spreading with a probability of damage healing ($q
= 1 - p$) is proposed and studied by means of Monte Carlo simulations. In the
limit $p \to 1$ the new model is mapped to the standard Ising model. It is
found that, for temperatures above the Onsager critical temperature ($T_{C}$),
there exist a no trivial finite value of $p$ that sets the critical point
($p_{c}$) for the onset of damage spreading. It is found that $p_{c}$ depends
on $T$, defining a critical curve at the border between damage spreading and
damage healing. Transitions along such curve are found to belong to the
universality class of directed percolation. The phase diagram of the model is
also evaluated showing that for large $T$ one has $p_{c} \propto (T-
T_{C})^{\alpha}$, with $\alpha = 1$. Within the phase where the damage remains
active, the stationary value of the damage depends lineally on both $p - p_{c}$
and $T - T_{C} $.