title:
Intrinsic Superconductivity at 25 K in Highly Oriented Pyrolytic
  Graphite

abstract:
  High resolution magnetoresistance data in highly oriented pyrolytic graphite
thin samples manifest non-homogenous superconductivity with critical
temperature $T_c \sim 25 $K. These data exhibit: i) hysteretic loops of
resistance versus magnetic field similar to Josephson-coupled grains, ii)
quantum Andreev's resonances and iii) absence of the Schubnikov-de Haas
oscillations. The results indicate that graphite is a system with
non-percolative superconducting domains immersed in a semiconducting-like
matrix. As possible origin of the superconductivity in graphite we discuss
interior-gap superconductivity when two very different electronic masses are
present.


title:
Work and dissipation fluctuations near the stochastic resonance of a
  colloidal particle

abstract:
  We study experimentally the fluctuations of the injected and dissipated
energy in a system of a colloidal particle trapped in a double well potential
periodically modulated by an external perturbation. The work done by the
external force and the dissipated energy are measured close to the stochastic
resonance where the injected power is maximum. We show that the steady state
fluctuation theorem holds in this system.


title:
Alternative Method for Determining the Feynman Propagator of a
  Non-Relativistic Quantum Mechanical Problem

abstract:
  A direct procedure for determining the propagator associated with a quantum
mechanical problem was given by the Path Integration Procedure of Feynman. The
Green function, which is the Fourier Transform with respect to the time
variable of the propagator, can be derived later. In our approach, with the
help of a Laplace transform, a direct way to get the energy dependent Green
function is presented, and the propagator can be obtained later with an inverse
Laplace transform. The method is illustrated through simple one dimensional
examples and for time independent potentials, though it can be generalized to
the derivation of more complicated propagators.


title: To Code or Not to Code Across Time: Space-Time Coding with Feedback

abstract:
  Space-time codes leverage the availability of multiple antennas to enhance
the reliability of communication over wireless channels. While space-time codes
have initially been designed with a focus on open-loop systems, recent
technological advances have enabled the possibility of low-rate feedback from
the receiver to the transmitter. The focus of this paper is on the implications
of this feedback in a single-user multi-antenna system with a general model for
spatial correlation. We assume a limited feedback model, that is, a coherent
receiver and statistics along with B bits of quantized channel information at
the transmitter. We study space-time coding with a family of linear dispersion
(LD) codes that meet an additional orthogonality constraint so as to ensure
low-complexity decoding. Our results show that, when the number of bits of
feedback (B) is small, a space-time coding scheme that is equivalent to
beamforming and does not code across time is optimal in a weak sense in that it
maximizes the average received SNR. As B increases, this weak optimality
transitions to optimality in a strong sense which is characterized by the
maximization of the average mutual information. Thus, from a system designer's
perspective, our work suggests that beamforming may not only be attractive from
a low-complexity viewpoint, but also from an information-theoretic viewpoint.


title:
Constraining the Symmetry Energy: A Journey in the Isospin Physics from
  Coulomb Barrier to Deconfinement

abstract:
  Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium
nuclear interaction in regions away from saturation. In this work we present a
selection of reaction observables in dissipative collisions particularly
sensitive to the isovector part of the interaction, i.e. to the symmetry term
of the nuclear Equation of State (EoS). At low energies the behavior of the
symmetry energy around saturation influences dissipation and fragment
production mechanisms. We will first discuss the recently observed Dynamical
Dipole Radiation, due to a collective neutron-proton oscillation during the
charge equilibration in fusion and deep-inelastic collisions. Important Iso-EOS
effects are stressed. Reactions induced by unstable 132Sn beams appear to be
very promising tools to test the sub-saturation Isovector EoS. New Isospin
sensitive observables are also presented for deep-inelastic, fragmentation
collisions and Isospin equilibration measurements (Imbalance Ratios). The high
density symmetry term can be derived from isospin effects on heavy ion
reactions at relativistic energies (few AGeV range), that can even allow a
``direct'' study of the covariant structure of the isovector interaction in the
hadron medium. Rather sensitive observables are proposed from collective flows
and from pion/kaon production. The possibility of the transition to a mixed
hadron-quark phase, at high baryon and isospin density, is finally suggested.
Some signatures could come from an expected ``neutron trapping'' effect. The
importance of studying violent collisions with radioactive beams from low to
relativistic energies is finally stressed.


Comment on "Theory of helimagnons in itinerant quantum systems" by
  D.Belitz, T.K.Kirpatrick and A.Rosch and "Cubic magnets with
  Dzyaloshinskii-Moriya interaction at low temperatures" by S.V.Maleyev


title: Molecular Dynamics Simulation of Plasma Surface Interaction

abstract:
  New interlayer intermolecular potential model was proposed and it represented
``ABAB'' staking of graphite. Hydrogen atom sputtering on graphite surface was
investigated using molecular dynamics simulation. In the initial short time
period, maintaining the flat structure of graphenes, hydrogen atoms brought
about the difference interaction process in each incident energy. The first
graphene often adsorbed 5 eV hydrogen atoms and reflected almost all of 15 eV
hydrogen atoms. The hydrogen atoms which were injected at 30 eV penetrated into
the inside of the graphite surface and were adsorbed between interlayer. The
desorption of C2H2 on the clear graphite surface was observed in only the case
incident at 5 eV. The animation of the MD simulation and radial distribution
function indicated that the graphenes were peeled off one by one at regular
interval. In common to the incident energy, the yielded molecules often had
chain structures terminated by hydrogen atoms. The erosion yield increased
compared with the case of no interlayer intermolecular force.


title: Effect of band structure on field emission of crystalline graphite

abstract:
  The field emission of crystalline AAA graphite is studied within a simple
analytical approach with account of the exact dispersion relation near the
Fermi level. The emission current is calculated for two crystal orientations
with respect to the applied electric field. It is found that the exponent of
the Fowler-Nordheim equation remains the same while the preexponential factor
is markedly modified. For both field directions, the linear field dependence is
found in weak fields and the standard quadratic Fowler-Nordheim behavior takes
place in strong fields. A strong dependence of the emission current from the
interlayer distance is observed. As an illustration of the method the known
case of a single-walled carbon nanotube is considered.


title: K fields, compactons, and thick branes

abstract:
  K fields, that is, fields with a non-standard kinetic term, allow for soliton
solutions with compact support, i.e., compactons. Compactons in 1+1 dimensions
may give rise to topological defects of the domain wall type and with finite
thickness in higher dimensions. Here we demonstrate that, for an appropriately
chosen kinetic term, propagation of linear perturbations is completely
suppressed outside the topological defect, confining the propagation of
particles inside the domain wall. On the other hand, inside the topological
defect the propagation of linear perturbations is of the standard type, in
spite of the non-standard kinetic term. Consequently, this compacton domain
wall may act like a brane of finite thickness which is embedded in a higher
dimensional space, but to which matter fields are constrained. In addition, we
find strong indications that, when gravity is taken into account, location of
gravity in the sense of Randall--Sundrum works for these compacton domain
walls. When seen from the bulk, these finite thickness branes, in fact, cannot
be distinguished from infinitely thin branes.


title:
Periodic orbits, localization in normal mode space, and the
  Fermi-Pasta-Ulam problem

abstract:
  The Fermi-Pasta-Ulam problem was one of the first computational experiments.
It has stirred the physics community since, and resisted a simple solution for
half a century. The combination of straightforward simulations, efficient
computational schemes for finding periodic orbits, and analytical estimates
allows us to achieve significant progress. Recent results on $q$-breathers,
which are time-periodic solutions that are localized in the space of normal
modes of a lattice and maximize the energy at a certain mode number, are
discussed, together with their relation to the Fermi-Pasta-Ulam problem. The
localization properties of a $q$-breather are characterized by intensive
parameters, that is, energy densities and wave numbers. By using scaling
arguments, $q$-breather solutions are constructed in systems of arbitrarily
large size. Frequency resonances in certain regions of wave number space lead
to the complete delocalization of $q$-breathers. The relation of these features
to the Fermi-Pasta-Ulam problem are discussed.


title:
Comment on ``Granular Entropy: Explicit Calculations for Planar
  Assemblies''

abstract:
  A Comment on the Letter by Raphael Blumenfeld and Sam F. Edwards, [Phys. Rev.
Lett. 90, 114303 (2003)].


title: Applications de la bi-quantification \`a la th\'eorie de Lie

abstract:
  This article is a survey about applications of bi-quantization theory in Lie
theory. We focus on a conjecture of M. Duflo. Most of the applications are
coming from our article with Alberto Cattaneo and some extensions are relating
discussions with my student. The end of the article is completely new. We prove
that the conjecture E=1 implies the Kashiwara-Vergne conjecture. Our
deformation is non geometric but uses a polynomial deformation of the
coefficients.


title: Heavy Ion Dynamics and Neutron Stars

abstract:
  Some considerations are reported, freely inspired from the presentations and
discussions during the Beijing Normal University Workshop on the above Subject,
held in July 2007. Of course this cannot be a complete summary but just a
collection of personal thougths aroused during the meeting.


title:
Collisional interaction limits between dark matters and baryons in
  `cooling flow' clusters

abstract:
  Presuming weak collisional interactions to exchange the kinetic energy
between dark matter and baryonic matter in a galaxy cluster, we re-examine the
effectiveness of this process in several `cooling flow' galaxy clusters using
available X-ray observations and infer an upper limit on the heavy dark matter
particle (DMP)$-$proton cross section $\sigma_{\rm xp}$. With a relative
collisional velocity $V-$dependent power-law form of $\sigma_{\rm
xp}=\sigma_0(V/10^3 {\rm km s^{-1}})^a$ where $a\leq 0$, our inferred upper
limit is $\sigma_0/m_{\rm x}\lsim 2\times10^{-25} {\rm cm}^2 {\rm GeV}^{-1}$
with $m_{\rm x}$ being the DMP mass. Based on a simple stability analysis of
the thermal energy balance equation, we argue that the mechanism of
DMP$-$baryon collisional interactions is unlikely to be a stable
nongravitational heating source of intracluster medium (ICM) in inner core
regions of `cooling flow' galaxy clusters.


title: Studying the interaction between microquasar jets and their environments

abstract:
  In high-mass microquasars (HMMQ), strong interactions between jets and
stellar winds at binary system scales could occur. In order to explore this
possibility, we have performed numerical 2-dimensional simulations of jets
crossing the dense stellar material to study how the jet will be affected by
these interactions. We find that the jet head generates strong shocks in the
wind. These shocks reduce the jet advance speed, and compress and heat up jet
and wind material. In addition, strong recollimation shocks can occur where
pressure balance between the jet side and the surrounding medium is reached.
All this, altogether with jet bending, could lead to the destruction of jets
with power $<10^{36} \rm{erg/s}$. The conditions around the outflow shocks
would be convenient for accelerating particles up to $\sim $TeV energies. These
accelerated particles could emit via synchrotron and inverse Compton (IC)
scattering if they were leptons, and via hadronic processes in case they were
hadrons.


title: Notions of absolutely continuous subspace for nonselfadjoint operators

abstract:
  We give an example of an operator with different weak and strong absolutely
continuous subspaces, and a counterexample to the duality problem for the
spectral components. Both examples are optimal in the scale of compact
operators.


title: Dynamics of Bloch vector in thermal Jaynes-Cummings model

abstract:
  In this paper, we investigate the dynamics of the Bloch vector of a single
two-level atom which interacts with a single quantized electromagnetic field
mode according to the Jaynes-Cummings model, where the field is initially
prepared in a thermal state. The time evolution of the Bloch vector S(t) seems
to be in complete disorder because of the thermal distribution of the initial
state of the field. Both the norm and the direction of S(t) oscillate hard and
their periods seem infinite. We observe that the trajectory of the time
evolution of S(t) in the two- or three-dimensional space does not form a closed
path. To remove the fast frequency oscillation from the trajectory, we take the
time-average of the Bloch vector S(t). We examine the histogram of
{S_{z}(n\Delta t)|n=0,1,...,N} for small \Delta t and large N. It represents an
absolute value of a derivative of the inverse function of S_{z}(t). (When the
inverse function of y=S_{z}(t) is a multi-valued function, the histogram
represents a summation of the absolute values of its derivatives at points
whose real parts are equal to y on the Riemann surface.) We examine the
dependence of the variance of the histogram on the temperature of the field. We
estimate the lower bound of the entanglement between the atom and the field.


title:
de Haas-van Alphen oscillations in the underdoped cuprate
  YBa$_2$Cu$_3$O$_{6.5}$

abstract:
  The de Haas-van Alphen effect was observed in the underdoped cuprate
YBa$_2$Cu$_3$O$_{6.5}$ via a torque technique in pulsed magnetic fields up to
59 T. Above an irreversibility field of $\sim$30 T, the magnetization exhibits
clear quantum oscillations with a single frequency of 540 T and a cyclotron
mass of 1.76 times the free electron mass, in excellent agreement with
previously observed Shubnikov-de Haas oscillations. The oscillations obey the
standard Lifshitz-Kosevich formula of Fermi-liquid theory. This thermodynamic
observation of quantum oscillations confirms the existence of a well-defined,
close and coherent, Fermi surface in the pseudogap phase of cuprates.


title: Three Dimensional Magnetic Correlations in Multiferroic LuFe2O4

abstract:
  We present single-crystal neutron diffraction measurements on multiferroic
LuFe2O4 showing phase transitions at 240 and 175 K. Magnetic reflections are
observed below each transition indicating that the magnetic interactions in
LuFe2O4 are 3-dimensional (3D) in character. The magnetic structure is refined
as a ferrimagnetic spin configuration below the 240 K transition. While 3D
magnetic correlations persists below 175 K, a significant broadening of the
magnetic peaks is observed along with the build up of a diffuse component to
the magnetic scattering.


title:
Radiation Hardness Studies in a CCD with High-Speed Column Parallel
  Readout

abstract:
  Charge Coupled Devices (CCDs) have been successfully used in several high
energy physics experiments over the past two decades. Their high spatial
resolution and thin sensitive layers make them an excellent tool for studying
short-lived particles. The Linear Collider Flavour Identification (LCFI)
collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex
detector of the International Linear Collider (ILC). The CPCCDs can be read out
many times faster than standard CCDs, significantly increasing their operating
speed. The results of detailed simulations of the charge transfer inefficiency
(CTI) of a prototype CPCCD are reported and studies of the influence of gate
voltage on the CTI described. The effects of bulk radiation damage on the CTI
of a CPCCD are studied by simulating the effects of two electron trap levels,
0.17 and 0.44 eV, at different concentrations and operating temperatures. The
dependence of the CTI on different occupancy levels (percentage of hit pixels)
and readout frequencies is also studied. The optimal operating temperature for
the CPCCD, where the effects of the charge trapping are at a minimum, is found
to be about 230 K for the range of readout speeds proposed for the ILC. The
results of the full simulation have been compared with a simple analytic model.


title: EPR argument and Bell inequalities for Bose-Einstein spin condensates

abstract:
  We discuss the properties of two Bose-Einstein condensates in different spin
states, represented quantum mechanically by a double Fock state. Individual
measurements of the spins of the particles are performed in transverse
directions (perpendicular to the spin quantization axis), giving access to the
relative phase of the two macroscopically occupied states. Before the first
spin measurement, the phase is completely undetermined; after a few
measurements, a more and more precise knowledge of its value emerges under the
effect of the quantum measurement process. This naturally leads to the usual
notion of a quasi-classical phase (Anderson phase) and to an interesting
transposition of the EPR (Einstein-Podolsky-Rosen) argument to macroscopic
physical quantities. The purpose of this article is to discuss this
transposition, as well as situations where the notion of a quasi-classical
phase is no longer sufficient to account for the quantum results, and where
significant violations of Bell type inequalities are predicted.


title:
Linear Lower Bounds for $\delta_c(p)$ for a Class of 2D Self-Destructive
  Percolation Models

abstract:
  The self-destructive percolation model is defined as follows: Consider
percolation with parameter $p > p_c$. Remove the infinite occupied cluster.
Finally, give each vertex (or, for bond percolation, each edge) that at this
stage is vacant, an extra chance $\delta$ to become occupied. Let $\delta_c(p)$
be the minimal value of $\delta$, needed to obtain an infinite occupied cluster
in the final configuration. This model was introduced some years ago by van den
Berg and Brouwer. They showed that, for the site model on the square lattice
(and a few other 2D lattices satisfying a special technical condition) that
$\delta_c(p)\geq\frac{(p-p_c)}{p}$. In particular, $\delta_c(p)$ is at least
linear in $p-p_c$.
  Although the arguments used by van den Berg and Brouwer look quite rigid, we
show that they can be suitably modified to obtain similar linear lower bounds
for $\delta_c(p)$ (with $p$ near $p_c$) for a much larger class of 2D lattices,
including bond percolation on the square and triangular lattices, and site
percolation on the star lattice (or matching lattice) of the square lattice.


title: Phase-referencing on BL Lac

abstract:
  We report the results of a phase-referencing study aimed at uncovering
precession of the VLBI jet of BL Lac. The observations were conducted at 8, 15,
22, and 43 GHz and consist of seven epochs spanning about two years. We
investigated the change in the absolute position of BL Lac's radio core by
means of phase-referencing with two nearby sources, 2151+431 and 2207+374. The
shift in the position of the core perpendicular to the jet is a signature of
precession. However, the periodic variations with an amplitude of ~0.15 mas and
a period of 1 year can be attributed to seasonal weather variations. We also
detect a trend in position of the core on the scale of ~0.1 mas over two years.


title:
SCUBA and Spitzer observations of the Taurus molecular cloud - pulling
  the bull's tail

abstract:
  We present continuum data from the Submillimetre Common-User Bolometer Array
(SCUBA) on the James Clerk Maxwell Telescope (JCMT), and the Mid-Infrared
Photometer for Spitzer (MIPS) on the Spitzer Space Telescope, at submillimetre
and infrared wavelengths respectively. We study the Taurus molecular cloud 1
(TMC1), and in particular the region of the Taurus Molecular Ring (TMR). In the
continuum data we see no real evidence for a ring, but rather we see one side
of it only, appearing as a filament. We name the filament `the bull's tail'.
The filament is seen in emission at 850, 450 and 160um, and in absorption at
70um. We compare the data with archive data from the Infra-Red Astronomical
Satellite (IRAS) at 12, 25, 60, 100um, in which the filament is also seen in
absorption. We find that the emission from the filament consists of two
components: a narrow, cold (~8K), central core; and a broader, slightly warmer
(~12K), shoulder of emission. We use a radiative transfer code to model the
filament's appearance, either in emission or absorption, simultaneously at each
of the different wavelengths. Our best fit model uses a Plummer-like density
profile and a homogeneous interstellar dust grain population. Unlike previous
work on a similar, but different filament in Taurus, we require no grain
coagulation to explain our data.


title: Proposal for a correlation induced spin-current polarizer

abstract:
  We propose a spin polarizer device composed of a quantum dot connected to the
spin polarized leads. The spin control of the current flowing through the
device is entirely due to the Coulomb interactions present inside the dot. We
show that the initial polarization present in the source lead can be reverted
or suppressed just by manipulating the gate voltage acting on the dot, the
presence of the external magnetic field is not required. The influence of the
temperature and finite bias on the efficiency of the current spin switching
effect is also discussed.


title:
Influence of surface-related strain and electric field on acceptor wave
  functions in Zincblende semiconductors

abstract:
  The spatial distribution of the local density of states (LDOS) at Mn
acceptors near the (110) surface of p-doped InAs is investigated by Scanning
Tunneling Microscopy (STM). The shapes of the acceptor contrasts for different
dopant depths under the surface are analyzed. Acceptors located within the
first ten subsurface layers of the semiconductor show a lower symmetry than
expected from theoretical predictions of the bulk acceptor wave function. They
exhibit a (001) mirror asymmetry. The degree of asymmetry depends on the
acceptor atoms' depths. The measured contrasts for acceptors buried below the
10th subsurface layer closely match the theoretically derived shape. Two
effects are able to explain the symmetry reduction: the strain field of the
surface relaxation and the tip-induced electric field.


title: Bundles of C*-algebras and the KK(X;-,-)-bifunctor

abstract:
  An overview about C*-algebra bundles with a Z-grading is presented, with
particular emphasis on classification questions. In particular, we discuss the
role of the representable KK(X ; -, -)-bifunctor introduced by Kasparov. As an
application, we consider Cuntz-Pimsner algebras associated with vector bundles,
and give a classification in terms of K-theoretical invariants in the case in
which the base space is an n-sphere.


title: Constraints on temporal variation of fundamental constants from GRBs

abstract:
  The formation of a strange or hybrid star from a neutron star progenitor is
believed to occur when the central stellar density exceeds a critical value. If
the transition from hadron to quark matter is of first order, the event has to
release a huge amount of energy in a very short time and we would be able to
observe the phenomenon even if it is at cosmological distance far from us; most
likely, such violent quark deconfinement would be associated with at least a
fraction of the observed gamma ray bursts. If we allow for temporal variations
of fundamental constants like $\Lambda_{QCD}$ or $G_N$, we can expect that
neutron stars with an initial central density just below the critical value can
enter into the region where strange or hybrid stars are the true ground state.
  From the observed rate of long gamma ray bursts, we are able to deduce the
constraint $\dot{G}_N/G_N \lesssim 10^{-17} {\rm yr^{-1}}$, which is about 5
orders of magnitude more stringent than the strongest previous bounds on a
possible increasing $G_N$.


title: Phase Transitions of the First Kind as Radiation Processes

abstract:
  Crystallization and vapor condensation are considered as processes of
sequential entering of single atoms/molecules into condensate. The latent heat
can be carry away by radiation of characteristic frequencies generated in the
course of transition. The estimated dependences of latent (radiated) energy of
boiling on temperature confirm and prove the well-known empirical Trouton's
rule applicable to many simple substances. It leads to the estimation of
interrelation of critical parameters of corresponding substances. Experimental
results of the authors and other researchers concerning crystallization from
the melt of different substances (alkali halides, sapphire, tellurium, ice,
copper) are presented, as well as condensation of water vapor, the
correspondence to the offered model is established. It allows developing of the
spectroscopy of phase transitions, and can lead to control of crystallization
process, to crystallization stimulated by the characteristic radiation, etc.
Formation of clouds in our atmosphere should be accompanied by characteristic
radiation detectable for meteorological warnings.


title:
360 degree domain wall generation in the soft layer of magnetic tunnel
  junctions

abstract:
  High spatial resolution X-ray photo-emission electron microscopy technique
has been used to study the influence of the dipolar coupling taking place
between the NiFe and the Co ferromagnetic electrodes of micron sized,
elliptical shaped magnetic tunnel junctions. The chemical selectivity of this
technique allows to observe independently the magnetic domain structure in each
ferromagnetic electrode. The combination of this powerful imaging technique
with micromagnetic simulations allows to evidence that a 360 degree domain wall
can be stabilized in the NiFe soft layer. In this letter, we discuss the origin
and the formation conditions of those 360 degree domain walls evidenced
experimentally and numerically.


title: Rulings of Legendrian knots as spanning surfaces

abstract:
  Each ruling of a Legendrian link can be naturally treated as a surface. For
knots, the ruling is 2-graded if and only if the surface is orientable. For
2-graded rulings of homogeneous (in particular, alternating) knots, we prove
that the genus of this surface is at most the genus of the knot. While this is
not true in general, we do prove that the canonical genus (a.k.a. diagram
genus) of any knot is an upper bound for the genera of its 2-graded rulings.


title: Generalized Ohm's law for relativistic plasmas

abstract:
  We generalise the relativistic expression of Ohm's law by studying a
multi-fluid system of charged species using the 1+3 covariant formulation of
general relativistic electrodynamics. This is done by providing a fully
relativistic, fully nonlinear propagation equation for the spatial component of
the electric 4-current. Our analysis proceeds along the lines of the
non-relativistic studies and extends previous relativistic work on cold
plasmas. Exploiting the compactness and transparency of the covariant
formalism, we provide a direct comparison with the standard Newtonian versions
of Ohm's law and identify the relativistic corrections in an unambiguous way.
The generalised expression of Ohm's law is initially given relative to an
arbitrary observer and for a multi-component relativistic charged medium. Then,
the law is written with respect to the Eckart frame and for a hot two-fluid
plasma with zero total charge. Finally, we apply our analysis to a cold
proton-electron plasma and recover the well known magnetohydrodynamic
expressions. In every step, we discuss the approximations made and identify
familiar effects, like the Biermann-battery and the Hall effect.


title:
Fundamental Solutions of the Instationary Schrodinger Difference
  Operator

abstract:
  In this paper we will study the existence of fundamental solutions for the
explicit and implicit backward time dependent Schodinger equation, via discrete
Fourier transform and its symbol for the Laplace operator. In both cases we
will prove that the discrete fundamental solutions obtained converges to the
continuous fundamental solution in the $l_1-$norm sense.


title:
Numerical experiments of adjusted BSSN systems for controlling
  constraint violations

abstract:
  We present our numerical comparisons between the BSSN formulation widely used
in numerical relativity today and its adjusted versions using constraints. We
performed three testbeds: gauge-wave, linear wave, and Gowdy-wave tests,
proposed by the Mexico workshop on the formulation problem of the Einstein
equations. We tried three kinds of adjustments, which were previously proposed
from the analysis of the constraint propagation equations, and investigated how
they improve the accuracy and stability of evolutions. We observed that the
signature of the proposed Lagrange multipliers are always right and the
adjustments improve the convergence and stability of the simulations. When the
original BSSN system already shows satisfactory good evolutions (e.g., linear
wave test), the adjusted versions also coincide with those evolutions; while in
some cases (e.g., gauge-wave or Gowdy-wave tests) the simulations using the
adjusted systems last 10 times as long as those using the original BSSN
equations. Our demonstrations imply a potential to construct a robust evolution
system against constraint violations even in highly dynamical situations.


title: Testing the RRPP vertex of effective Regge action

abstract:
  In frames of effective Regge action the vertices describing conversion of two
reggeized gluons to one two and three ordinary gluons was constructed. The
self-consistency: Bose symmetry and gauge invariance properties checks was
shown to be fulfilled. The simplest one with creation of a single gluon was
intensively verified in programs of experimental and theoretical treatment
since it determine the kernel of of the known BFKL equation. Here we discuss
the possibility to check the vertex with creation of two real gluons, which can
reveal itself in process of scalar mesons production in high energy peripheral
nucleons collisions. We show that the mechanisms which include emission of two
gluons in the same effective vertex contribution dominate compared with one
with the creation of two separate gluons. Numerical estimations of cross
section of pair of charged pions production for LHC facility give the value or
order $10 mb$. As well we estimate the excess of production of positively
charged muons (as a decay of pions) created by cosmic ray proton collisions
with the atmosphere gas nuclei to be in a reasonable agreement with modern
data.


title: Transform martingale estimating functions

abstract:
  An estimation method is proposed for a wide variety of discrete time
stochastic processes that have an intractable likelihood function but are
otherwise conveniently specified by an integral transform such as the
characteristic function, the Laplace transform or the probability generating
function. This method involves the construction of classes of transform-based
martingale estimating functions that fit into the general framework of
quasi-likelihood. In the parametric setting of a discrete time stochastic
process, we obtain transform quasi-score functions by projecting the
unavailable score function onto the special linear spaces formed by these
classes. The specification of the process by any of the main integral
transforms makes possible an arbitrarily close approximation of the score
function in an infinite-dimensional Hilbert space by optimally combining
transform martingale quasi-score functions. It also allows an extension of the
domain of application of quasi-likelihood methodology to processes with
infinite conditional second moment.


title: A formula for the spectral projection of the time operator

abstract:
  In this paper, we study the one-level Friedrichs model with using the quantum
time super-operator that predicts the excited state decay inside the continuum.
Its survival probability in long time limit is an algebraically decreasing
function and an exponentially decreasing multiplied by the oscillating
functions.


title:
Discrete symmetry with compact fundamental domain, and geometric simple
  connectivity - A provisional Outline of work in Progress -

abstract:
  We show that a certain geometric property, the QSF introduced by S. Brick and
M. Mihalik, is universally true for {\ibf all} finitely presented groups
$\Gamma$. One way of defining this property is the existence of a smooth
compact manifold $M$ with $\pi_1 M = \Gamma$, such that $\tilde M$ is
geometrically simply-connected ({\it i.e.} without handles of index $\lambda =
1$). There are also alternative, more group-theoretical definitions, which are
presentation independent. But $\Gamma \in {\rm QSF}$ is not only a universal
property, it is quite highly non-trivial too; its very special case for $\Gamma
= \pi_1 M^3$ (where it means $\pi_1^{\infty} \tilde M^3 = 0$) is actually
already known, as a corollary of G. Perelman's big breakthrough on the
Geometrization of 3-Manifolds.


title: An evolutionary model with Turing machines

abstract:
  The development of a large non-coding fraction in eukaryotic DNA and the
phenomenon of the code-bloat in the field of evolutionary computations show a
striking similarity. This seems to suggest that (in the presence of mechanisms
of code growth) the evolution of a complex code can't be attained without
maintaining a large inactive fraction. To test this hypothesis we performed
computer simulations of an evolutionary toy model for Turing machines, studying
the relations among fitness and coding/non-coding ratio while varying mutation
and code growth rates. The results suggest that, in our model, having a large
reservoir of non-coding states constitutes a great (long term) evolutionary
advantage.


title:
The Impact of Heterogeneous Trading Rules on the Limit Order Book and
  Order Flows

abstract:
  In this paper we develop a model of an order-driven market where traders set
bids and asks and post market or limit orders according to exogenously fixed
rules. Agents are assumed to have three components to the expectation of future
asset returns, namely-fundamentalist, chartist and noise trader. Furthermore
agents differ in the characteristics describing these components, such as time
horizon, risk aversion and the weights given to the various components. The
model developed here extends a great deal of earlier literature in that the
order submissions of agents are determined by utility maximisation, rather than
the mechanical unit order size that is commonly assumed. In this way the order
flow is better related to the ongoing evolution of the market. For the given
market structure we analyze the impact of the three components of the trading
strategies on the statistical properties of prices and order flows and observe
that it is the chartist strategy that is mainly responsible of the fat tails
and clustering in the artificial price data generated by the model. The paper
provides further evidence that large price changes are likely to be generated
by the presence of large gaps in the book.


title: Mathematical model for fractal manifold

abstract:
  We have built a new kind of manifolds which leads to an alternative new
geometrical space. The study of the nowhere differentiable functions via a
family of mean functions leads to a new characterization of this category of
functions. A fluctuant manifold has been built with an appearance of a new
structure on it at every scale, and we embedded into it an internal structure
to transform its fluctuant geometry to a new fixed geometry. This approach
leads us to what we call fractal manifold. The elements of this kind of
manifold appear locally as tiny double strings, with an appearance of new
structure at every step of approximation. We have obtained a variable
dimensional space which is locally neither a continuum nor a discrete, but a
mixture of both. Space acquires a variable geometry, it becomes explicitly
dependent on the approximation process, and the geometry on it assumed to be
characterized not only by curvature, but also by the appearance of new
structure at every step of approximation.


title: Semi-classical calculus on manifolds with ends and weighted Lp estimates

abstract:
  For a class of non compact Riemannian manifolds with ends, we give
pseudo-differential expansions of bounded functions of the semi-classical
Laplacian and study related Lp boundedness properties.


title:
Tomographic Simulations of Accretion Disks in Cataclysmic Variables -
  Flickering and Wind

abstract:
  Both continuum and emission line flickering are phenomena directly associated
with the mass accretion process. In this work we simulate accretion disk
Doppler maps including the effects of winds and flickering flares. Synthetic
flickering Doppler maps are calculated and the effect of the flickering
parameters on the maps is explored. Jets and winds occur in many astrophysical
objects where accretion disks are present. Jets are generally absent among the
cataclysmic variables (CVs), but there is evidence of mass loss by wind in many
objects. CVs are ideal objects to study accretion disks and consequently to
study the wind associated with these disks. We also present simulations of
accretion disks including the presence of a wind with orbital phase resolution.
Synthetic H-alpha line profiles in the optical region are obtained and their
corresponding Doppler maps are calculated. The effect of the wind simulation
parameters on the wind line profiles is also explored. From this study we
verified that optically thick lines and/or emission by diffuse material into
the primary Roche lobe are necessary to generate single peaked line profiles,
often seen in CVs. The future accounting of these effects is suggested for
interpreting Doppler tomography reconstructions.


title: Littlewood-Paley decompositions on manifolds with ends

abstract:
  For certain non compact Riemannian manifolds with ends, we obtain
Littlewood-Paley type estimates on (weighted) Lp spaces, using the usual square
function defined by a dyadic partition.


title:
Mid-Infrared waveguides and negative refraction with anisotropic
  metamaterials

abstract:
  We propose two metamaterial waveguides, operating in the mid-IR, which would
display negative refraction. The first waveguide is a metallic strip
incorporating quantum wells, whereas the second is a dielectric waveguide which
incorporates quantum wells. The negative refraction of both waveguides occurs
around the intersubband transition (ISBT) of the quantum wells and is dependent
upon the 2D concentration of electron within the wells; these materials could
be grown by conventional semiconductor technology (MBE) and the electron
concentration within the wells controlled externally by electric fields or
optically pumping.


title: Strichartz estimates on asymptotically hyperbolic manifolds

abstract:
  We prove local in time Strichartz estimates without loss for the restriction
of the solution of the Schroedinger equation, outside a large compact set, on a
class of asymptotically hyperbolic manifolds.


title: Representations of quivers, their generalizations and invariants

abstract:
  This paper is a survey on invariants of representations of quivers and their
generalizations. We present the description of generating systems for
invariants and relations between generators.


title:
Asymptotic theory of least squares estimators for nearly unstable
  processes under strong dependence

abstract:
  This paper considers the effect of least squares procedures for nearly
unstable linear time series with strongly dependent innovations. Under a
general framework and appropriate scaling, it is shown that ordinary least
squares procedures converge to functionals of fractional Ornstein--Uhlenbeck
processes. We use fractional integrated noise as an example to illustrate the
important ideas. In this case, the functionals bear only formal analogy to
those in the classical framework with uncorrelated innovations, with Wiener
processes being replaced by fractional Brownian motions. It is also shown that
limit theorems for the functionals involve nonstandard scaling and nonstandard
limiting distributions. Results of this paper shed light on the asymptotic
behavior of nearly unstable long-memory processes.


title:
Master Integrals for Fermionic Contributions to Massless Three-Loop Form
  Factors

abstract:
  In this letter we continue the calculation of master integrals for massless
three-loop form factors by giving analytical results for those integrals which
are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and
N_F/N. Working in dimensional regularisation, we express one of the integrals
in a closed form which is exact to all orders in epsilon, containing
Gamma-functions and hypergeometric functions of unit argument. In all other
cases we derive multiple Mellin-Barnes representations from which the
coefficients of the Laurent expansion in epsilon are extracted in an analytical
form. To obtain the finite part of the three-loop quark and gluon form factors,
all coefficients through transcendentality six in the Riemann zeta-function
have to be included.


title:
An Estimation of Distribution Algorithm with Intelligent Local Search
  for Rule-based Nurse Rostering

abstract:
  This paper proposes a new memetic evolutionary algorithm to achieve explicit
learning in rule-based nurse rostering, which involves applying a set of
heuristic rules for each nurse's assignment. The main framework of the
algorithm is an estimation of distribution algorithm, in which an ant-miner
methodology improves the individual solutions produced in each generation.
Unlike our previous work (where learning is implicit), the learning in the
memetic estimation of distribution algorithm is explicit, i.e. we are able to
identify building blocks directly. The overall approach learns by building a
probabilistic model, i.e. an estimation of the probability distribution of
individual nurse-rule pairs that are used to construct schedules. The local
search processor (i.e. the ant-miner) reinforces nurse-rule pairs that receive
higher rewards. A challenging real world nurse rostering problem is used as the
test problem. Computational results show that the proposed approach outperforms
most existing approaches. It is suggested that the learning methodologies
suggested in this paper may be applied to other scheduling problems where
schedules are built systematically according to specific rules


title:
Characterization of large area photomultipliers and its application to
  dark matter search with noble liquid detectors

abstract:
  There is growing interest in the use of noble liquid detectors to study
particle properties and search for new phenomena. In particular, they are
extremely suitable for performing direct searches for dark matter. In this kind
of experiments, the light produced after an interaction within the sensitive
volume is usually read-out by photomultipliers. The need to go to masses in the
tonne scale to explore deeper regions of the parameter space, calls for the use
of large area photomultipliers. In this paper we address the need to perform
laboratory calibration measurements of these large photomultipliers, in
particular to characterize its behaviour at cryogenic temperatures where no
reference from the manufacturer is available. We present comparative tests of
phototubes from two companies. The tests are performed in conditions similar to
those of operation in a real experiment. Measurements of the most relevant
phototube parameters (quantum efficiency, gain, linearity, etc.) both at room
and liquid Argon temperatures are reported. The results show that the studied
phototubes comply with the stringent requirements posed by current dark matter
searches performed with noble-liquid detectors.


title: The WFCAM Science Archive

abstract:
  We describe the WFCAM Science Archive (WSA), which is the primary point of
access for users of data from the wide-field infrared camera WFCAM on the
United Kingdom Infrared Telescope (UKIRT), especially science catalogue
products from the UKIRT Infrared Deep Sky Survey (UKIDSS). We describe the
database design with emphasis on those aspects of the system that enable users
to fully exploit the survey datasets in a variety of different ways. We give
details of the database-driven curation applications that take data from the
standard nightly pipeline-processed and calibrated files for the production of
science-ready survey datasets. We describe the fundamentals of querying
relational databases with a set of astronomy usage examples, and illustrate the
results.


title: Clustering with Transitive Distance and K-Means Duality

abstract:
  Recent spectral clustering methods are a propular and powerful technique for
data clustering. These methods need to solve the eigenproblem whose
computational complexity is $O(n^3)$, where $n$ is the number of data samples.
In this paper, a non-eigenproblem based clustering method is proposed to deal
with the clustering problem. Its performance is comparable to the spectral
clustering algorithms but it is more efficient with computational complexity
$O(n^2)$. We show that with a transitive distance and an observed property,
called K-means duality, our algorithm can be used to handle data sets with
complex cluster shapes, multi-scale clusters, and noise. Moreover, no
parameters except the number of clusters need to be set in our algorithm.


title: Two-Dimensional Quantum Gravity with Boundary

abstract:
  Using the recently found first order formulation of two-dimensional dilaton
gravity with boundary, we perform a Hamiltonian analysis and subsequent path
integral quantization. The importance of the boundary terms to obtain the
correct quantum result are outlined and the quantum triviality of the theory is
shown to hold with this modification as well. We compare with recent classical
results and comment on further applications.


title:
CutTools: a program implementing the OPP reduction method to compute
  one-loop amplitudes

abstract:
  We present a program that implements the OPP reduction method to extract the
coefficients of the one-loop scalar integrals from a user defined
(sub)-amplitude or Feynman Diagram, as well as the rational terms coming from
the 4-dimensional part of the numerator. The rational pieces coming from the
epsilon-dimensional part of the numerator are treated as an external input, and
can be computed with the help of dedicated tree-level like Feynman rules.
  Possible numerical instabilities are dealt with the help of arbitrary
precision routines, that activate only when needed.


title:
Stochastic domination for a hidden Markov chain with applications to the
  contact process in a randomly evolving environment

abstract:
  The ordinary contact process is used to model the spread of a disease in a
population. In this model, each infected individual waits an exponentially
distributed time with parameter 1 before becoming healthy. In this paper, we
introduce and study the contact process in a randomly evolving environment.
Here we associate to every individual an independent two-state, $\{0,1\},$
background process. Given $\delta_0<\delta_1,$ if the background process is in
state $0,$ the individual (if infected) becomes healthy at rate $\delta_0,$
while if the background process is in state $1,$ it becomes healthy at rate
$\delta_1.$ By stochastically comparing the contact process in a randomly
evolving environment to the ordinary contact process, we will investigate
matters of extinction and that of weak and strong survival. A key step in our
analysis is to obtain stochastic domination results between certain point
processes. We do this by starting out in a discrete setting and then taking
continuous time limits.


title:
Higher-order asymptotic normality of approximations to the modified
  signed likelihood ratio statistic for regular models

abstract:
  Approximations to the modified signed likelihood ratio statistic are
asymptotically standard normal with error of order $n^{-1}$, where $n$ is the
sample size. Proofs of this fact generally require that the sufficient
statistic of the model be written as $(\hat{\theta},a)$, where $\hat{\theta}$
is the maximum likelihood estimator of the parameter $\theta$ of the model and
$a$ is an ancillary statistic. This condition is very difficult or impossible
to verify for many models. However, calculation of the statistics themselves
does not require this condition. The goal of this paper is to provide
conditions under which these statistics are asymptotically normally distributed
to order $n^{-1}$ without making any assumption about the sufficient statistic
of the model.


title: Greybody Factors for Rotating Black Holes on Codimension-2 Branes

abstract:
  We study the absorption probability and Hawking radiation of the scalar field
in the rotating black holes on codimension-2 branes. We find that finite brane
tension modifies the standard results in Hawking radiation if compared with the
case when brane tension is completely negligible. We observe that the rotation
of the black hole brings richer physics. Nonzero angular momentum triggers the
super-radiance which becomes stronger when the angular momentum increases. We
also find that rotations along different angles influence the result in
absorption probability and Hawking radiation. Compared with the black hole
rotating orthogonal to the brane, in the background that black hole spins on
the brane, its angular momentum brings less super-radiance effect and the brane
tension increases the range of frequency to accommodate super-radiance. These
information can help us know more about the rotating codimension-2 black holes.


title:
A note on the Near Flat Limit for strings in the Maldacena-Nunez
  background

abstract:
  Recently Maldacena and Swanson suggested a new limit of string theory on the
$AdS_5\times S^5$ background, the so called near flat space limit. The
resulting reduced theory interpolates between the pp-wave limit and giant
magnon type string solutions. It was shown that the reduced model possess many
features of the original theory. On the other hand, theories with less
supersymmetry are of great importance for the string/gauge theory
correspondence. In this paper we study the near flat limit reduction of string
theory on the Maldacena-Nunez background, which is dual to $\N=1$ Yang-Mills
theory. The reduced model interpolates between the pp-wave limit and a certain
magnon type subsector of the theory. The similarity of the structures of the
reduced model obtained here and that by Maldacena and Swanson indicates the
possibility of existence of integrable subsectors of strings on the
Maldacena-Nunez background.


title: Growing and moving low-mass planets in non-isothermal disks

abstract:
  We study the interaction of a low-mass planet with a protoplanetary disk with
a realistic treatment of the energy balance by doing radiation-hydrodynamical
simulations. We look at accretion and migration rates and compare them to
isothermal studies. We used a three-dimensional version of the hydrodynamical
method RODEO, together with radiative transport in the flux-limited diffusion
approach. The accretion rate, as well as the torque on the planet, depend
critically on the ability of the disk to cool efficiently. For densities
appropriate to 5 AU in the solar nebula, the accretion rate drops by more than
an order of magnitude compared to isothermal models, while at the same time the
torque on the planet is positive, indicating outward migration. It is necessary
to lower the density by a factor of 2 to recover inward migration and more than
2 orders of magnitude to recover the usual Type I migration. The torque appears
to be proportional to the radial entropy gradient in the unperturbed disk.
These findings are critical for the survival of protoplanets, and they should
ultimately find their way into population synthesis models.


title: Cosmic acceleration from interaction of ordinary fluids

abstract:
  Cosmological models with two interacting fluids, each satisfying the strong
energy condition, are studied in the framework of classical General Relativity.
If the interactions are phenomenologically described by a power law in the
scale factor, the two initial interacting fluids can be equivalently
substituted by two non interacting effective fluids, where one of them may
violate the strong energy condition and/or have negative energy density.
Analytical solutions of the Friedmann equations of this general setting are
obtained and studied. One may have, depending on the scale where the
interaction becomes important, non singular universes with early accelerated
phase, or singular models with transition from decelerated to accelerated
expansion at large scales. Among the first, there are bouncing models where
contraction is stopped by the interaction. In the second case, one obtains dark
energy expansion rates without dark energy, like $\Lambda$CDM or phantomic
accelerated expansions without cosmological constant or phantoms, respectively.


title:
The Effect of Primordial Non--Gaussianity on the Topology of Large-Scale
  Structure

abstract:
  We study the effect of primordial non-Gaussianity on the development of
large-scale cosmic structure using high-resolution N-body simulations. In
particular, we focus on the topological properties of the "cosmic web",
quantitatively characterized by the Minkowski Functionals, for models with
quadratic non-linearities with different values of the usual non-Gaussianity
parameter fNL. In the weakly non-linear regime, we find that analytic formulae
derived from perturbation theory agree with the numerical results within a few
percent of the amplitude of each MF when |fNL|<1000. In the non-linear regime,
the detailed behavior of the MFs as functions of threshold density deviates
more strongly from the analytical curves, while the overall amplitude of the
primordial non-Gaussian effect remains comparable to the perturbative
prediction. When smaller-scale information is included, the influence of
primordial non-Gaussianity becomes increasingly significant statistically due
to decreasing sample variance. We find that the effect of the primordial
non-Gaussianity with |fNL|=50 is comparable to the sample variance of mass
density fields with a volume of 0.125(Gpc/h)^3 when they are smoothed by
Gaussian filter at a scale of 5Mpc/h. The detectability of this effect in
actual galaxy surveys will strongly depend upon residual uncertainties in
cosmological parameters and galaxy biasing.


title: Recent Astrochemical Results on Star-Forming Regions

abstract:
  This review discusses recent results on the astrochemistry of (mostly
high-mass) star-forming regions. After an introduction on the use of chemistry
in astrophysics and some basic concepts of astrochemistry, specific results are
presented. Highlighted areas are the use of chemistry in the search for massive
circumstellar disks, the interaction of molecular clouds with cosmic rays, and
the feedback effects of protostellar irradiation on the parent molecular cloud.
The review concludes with a discussion of future observational opportunities.


title: Very strict selectional restrictions

abstract:
  We discuss the characteristics and behaviour of two parallel classes of verbs
in two Romance languages, French and Portuguese. Examples of these verbs are
Port. abater [gado] and Fr. abattre [b\'etail], both meaning "slaughter
[cattle]". In both languages, the definition of the class of verbs includes
several features: - They have only one essential complement, which is a direct
object. - The nominal distribution of the complement is very limited, i.e., few
nouns can be selected as head nouns of the complement. However, this selection
is not restricted to a single noun, as would be the case for verbal idioms such
as Fr. monter la garde "mount guard". - We excluded from the class
constructions which are reductions of more complex constructions, e.g. Port.
afinar [instrumento] com "tune [instrument] with".


title: Oscillating Quintessence

abstract:
  An oscillating scalar field as a quintessence model for dark energy is
proposed. The case of a power-law potential is particularly intriguing and is
the focus of the present article. In this model the equation of state w_{OQ} of
dark energy is a constant determined simply by the power n in the potential
through w_{OQ} = (n-2)/(n+2). Accordingly, when 0 < n < 1, the oscillating
quintessence can provide repulsive gravity and drive the cosmic acceleration.
The condition for oscillation and the constraints from observations are
investigated. For this new scenario a specific natural model with much less
fine tuning is presented.


title:
Star formation, metallicity gradient and ionized gas: clues to the
  formation of the elliptical galaxies NGC6868 and NGC5903

abstract:
  The stellar population, metallicity distribution and ionized gas in the
elliptical galaxies NGC 6868 and NGC 5903 are investigated in this paper by
means of long-slit spectroscopy and stellar population synthesis. Lick indices
in both galaxies present a negative gradient indicating an overabundance of Fe,
Mg, Na and TiO in the central parts with respect to the external regions.
Concerning the emitting gas conspicuously detected in NGC 6868, we test three
hypotheses as ionizing source: an H II region, post-AGB stars and an Active
Galactic Nucleus (AGN). Diagnostic diagrams involving the ratios
$[NII]_{\lambda6584}/H\alpha$, $[OI]_{\lambda6300}/H\alpha$ and
$[SII]_{\lambda6717,31}/H\alpha$, indicate that values measured in the central
region of NGC 6868 are typical of LINERs. Together with the stellar population
synthesis, this result suggests that the main source of gas ionization in NGC
6868 is non-thermal, produced by a low-luminosity AGN, probably with some
contribution of shocks to explain ionization at distances of $\sim3.5$ kpc from
the nucleus.


title: Quantum Benchmark for Teleportation and Storage of Squeezed States

abstract:
  We provide a quantum benchmark for teleportation and storage of single-mode
squeezed states with zero displacement and a completely unknown degree of
squeezing along a given direction. For pure squeezed input states, a fidelity
higher than 81.5% has to be attained in order to outperform any classical
strategy based on an estimation of the unknown squeezing and repreparation of
squeezed states. For squeezed thermal input states, we derive an upper and a
lower bound on the classical average fidelity which tighten for moderate degree
of mixedness. These results enable a critical discussion of recent experiments
with squeezed light.


title: On eigenvalues of rectangular matrices

abstract:
  Given a $(k+1)$-tuple $A, B_1,...,B_k$ of $(m\times n)$-matrices with $m\le
n$ we call the set of all $k$-tuples of complex numbers $\{\la_1,...,\la_k\}$
such that the linear combination $A+\la_1B_1+\la_2B_2+...+\la_kB_k$ has rank
smaller than $m$ the {\it eigenvalue locus} of the latter pencil. Motivated
primarily by applications to multi-parameter generalizations of the
Heine-Stieltjes spectral problem, see \cite{He} and \cite{Vol}, we study a
number of properties of the eigenvalue locus in the most important case
$k=n-m+1$.


title: The Navier wall law at a boundary with random roughness

abstract:
  We consider the Navier-Stokes equation in a domain with irregular boundaries.
The irregularity is modeled by a spatially homogeneous random process, with
typical size $\eps \ll 1$. In a parent paper, we derived a homogenized boundary
condition of Navier type as $\eps \to 0$. We show here that for a large class
of boundaries, this Navier condition provides a $O(\eps^{3/2} |\ln
\eps|^{1/2})$ approximation in $L^2$, instead of $O(\eps^{3/2})$ for periodic
irregularities. Our result relies on the study of an auxiliary boundary layer
system. Decay properties of this boundary layer are deduced from a central
limit theorem for dependent variables.


title:
Dicke-like effect in spin-polarized transport through coupled quantum
  dots

abstract:
  Spin-dependent electronic transport through a quantum dot side-coupled to two
quantum dots and attached to ferromagnetic leads with collinear (parallel and
antiparallel) magnetizations is analyzed theoretically. The intra-dot Coulomb
correlations are taken into account, whereas the inter-dot ones are neglected.
Transport characteristics, i.e. conductance and tunnel magnetoresistance
associated with the magnetization rotation from parallel to antiparallel
configurations, are calculated by the noneqiulibrium Green function technique.
The Green functions are derived by the equation of motion method in the
Hartree-Fock approximation. The conductance spectra are shown to reveal
features similar to the Dicke resonance in atomic physics.


title: XMM-Newton X-ray study of early type stars in the Carina OB1 association

abstract:
  X-ray properties of the stellar population in the Carina OB1 association are
examined with special emphasis on early-type stars. Their spectral
characteristics provide some clues to understanding the nature of X-ray
formation mechanisms in the winds of single and binary early-type stars. A
timing and spectral analysis of five observations with XMM-Newton is performed
using various statistical tests and thermal spectral models. 235 point sources
have been detected within the field of view. Several of these sources are
probably pre-main sequence stars with characteristic short-term variability.
Seven sources are possible background AGNs. Spectral analysis of twenty three
sources of type OB and WR 25 was performed. We derived spectral parameters of
the sources and their fluxes in three energy bands. Estimating the interstellar
absorption for every source and the distance to the nebula, we derived X-ray
luminosities of these stars and compared them to their bolometric luminosities.
We discuss possible reasons for the fact that, on average, the observed X-ray
properties of binary and single early type stars are not very different, and
give several possible explanations.


title: Neutron matter at finite temperature

abstract:
  We calculate the neutron matter equation of state at finite temperature based
on low-momentum two- and three-nucleon interactions. The free energy is
obtained from a loop expansion around the Hartree-Fock energy, including
contributions from normal and anomalous diagrams. We focus on densities below
saturation density with temperatures T <= 10 MeV and compare our results to the
model-independent virial equation of state and to variational calculations.
Good agreement with the virial equation of state is found at low density. We
provide simple estimates for the theoretical error, important for
extrapolations to astrophysical conditions.


title:
Torque magnetometry studies of new low temperature metamagnetic states
  in ErNi_{2}B_{2}C

abstract:
  The metamagnetic transitions in single-crystal ErNi$_2$B$_2$C have been
studied at 1.9 K with a Quantum Design torque magnetometer. The critical fields
of the transitions depend crucially on the angle between applied field and the
easy axis [100]. Torque measurements have been made while changing angular
direction of the magnetic field (parallel to basal tetragonal $ab$-planes) in a
wide angular range (more than two quadrants). Sequences of metamagnetic
transitions with increasing field are found to be different for the magnetic
field along (or close enough to) the easy [100] axis from that near the hard
[110] axis. The study have revealed new metamagnetic states in ErNi$_{2}$B$_2$C
which were not apparent in previous longitudinal-magnetization and neutron
studies.


title: Urban segregation with cheap and expensive residences

abstract:
  In this paper we study urban segregation of two different communities A and
B, poor and rich, distributed randomly on finite samples, to check cheap and
expensive residences. For this purpose we avoid the complications of the
Schelling model which are not necessary and instead we use the Ising model on
500 x 500 square lattice, which give similar results, with random magnetic
field at lower and higher temperatures (kT/J = 2.0, 99.0) in finite times equal
to 40, 400, 4000 and 40,000. This random-field Ising magnet is a suitable
model, where each site of the square lattice carries a magnetic field h which
is randomly up (expensive) or down (cheap). The resulting addition to the
energy prefers up spins on the expensive and down spins on the cheap sites. Our
simulations were carried out using a 50-lines FORTRAN program. We present at a
lower temperature (2.0) a time series of pictures, separating growing from
non-growing domains. A small random field (h = +- 0.1) allows for large
domains, while a large random field (h = +- 0.9) allows only small clusters. At
higher temperature (99.0) we could not obtain growing domains.


title: The helicity constraint in spherical shell dynamos

abstract:
  The motivation for considering distributed large scale dynamos in the solar
context is reviewed in connection with the magnetic helicity constraint.
Preliminary accounts of 3-dimensional direct numerical simulations (in
spherical shell segments) and simulations of 2-dimensional mean field models
(in spherical shells) are presented. Interesting similarities as well as some
differences are noted.


title: Geometrical Domain of Spin 1/2 Probability Mass Function

abstract:
  The quantum analogue of the classical characteristic function for a spin 1/2
assembly is considered and the probability mass function of the random vector
associated with the assembly is derived. It is seen that the positive regions
of Wigner and Margenau-Hill quasi distributions for the three components of
spin, correspond to a trivariate probability mass function. We identify the
domain of these positive regions as an Octahedron inscribed in the Bloch sphere
with its vertices on the surface of the sphere. It is in this domain that a
quantum characteristic function characterizing the quasi distribution, admits a
probability mass function in IR^3 . It is also observed that the classical
variates X1, X2, X3 corresponding to the 3 spin operators
\sigma_1,\sigma_2,\sigma_3 in the domain, are independent iff the Bloch vector
lies on any one of the axes.


title: Complex surface spin polarization of the La0.7Sr0.3MnO3 films

abstract:
  The surface spin polarization in the epitaxial films of a prototype
manganite, La0.7Sr0.3MnO3, has been investigated by Scanning Tunneling
Spectroscopy with ferromagnetic SP tips at room temperature. The manganite
surface splits into ferromagnetic (FM) and paramagnetic(PM) regions
characterized by metallic and insulating like behavior respectively. Spin
polarized spectroscopy with Ni tips has been performed separately for the two
phases, and the results compared with standard W and Pt tips. While PM exhibits
featureless tunneling characteristics, the FM regions exhibit at room
temperature strongly nonlinear behavior with a band-gap like behavior. The spin
resolved density of states of the FM regions of the manganite has been
extracted by the deconvolution of the spectroscopic curves. It indicates very
high spin polarization (nearly halfmetallic behavior) with the spin down band
separated from Fermi level by 0.4 eV. This value corresponds exactly to the gap
value measured for the whole surface of this manganite at low temperatures.
Thus the surface of the La0.7Sr0.3MnO3 films maintain even at room temperature
nano- and micrometric islands of very high spin polarization, while the total
polarization is given by the coverage of the surface by FM regions. This result
is extremely important for spintronic applications of this material and
indicates possible roots for the realization of manganite nanosized devices
with extremely high spin polarization.


title: Thermal History of Solid 4He Under Oscillation

abstract:
  We have studied the thermal history of the resonant frequency of a torsional
oscillator containing solid 4He. We find that the magnitude of the frequency
shift that occurs below 100 mK is multivalued in the low temperature limit,
with the exact value depending on how the state is prepared. This result can be
qualitatively explained in terms of the motion and pinning of quantized
vortices within the sample. Several aspects of the data are also consistent
with the response of dislocation lines to oscillating stress fields imposed on
the solid.


title:
A Representation of Multiplicative Arithmetic Functions by Symmetric
  Polynomials

abstract:
  We give a representation of the classical theory of multiplicative arithmetic
functions (MF)in the ring of symmetric polynomials. The basis of the ring of
symmetric polynomials that we use is the isobaric basis, a basis especially
sensitive to the combinatorics of partitions of the integers. The representing
elements are recursive sequences of Schur polynomials evaluated at subrings of
the complex numbers. The multiplicative arithmetic functions are units in the
Dirichlet ring of arithmetic functions, and their properties can be described
locally, that is, at each prime number $p$. Our representation is, hence, a
local representation. One such representing sequence is the sequence of
generalized Fibonacci polynomials. In general the sequences consist of
Schur-hook polynomials. This representation enables us to clarify and
generalize classical results, e.g., the Busche-Ramanujan identity, as well as
to give a richer structural description of the convolution group of
multiplicative functions. It is a consequence of the representation that the
MF's can be defined in a natural way on the negative powers of the prime $p$.


title: Gibbsianness versus Non-Gibbsianness of time-evolved planar rotor models

abstract:
  We study the Gibbsian character of time-evolved planar rotor systems on Z^d,
d at least 2, in the transient regime, evolving with stochastic dynamics and
starting with an initial Gibbs measure. We model the system by interacting
Brownian diffusions, moving on circles. We prove that for small times and
arbitrary initial Gibbs measures \nu, or for long times and both high- or
infinite-temperature measure and dynamics, the evolved measure \nu^t stays
Gibbsian. Furthermore we show that for a low-temperature initial measure \nu,
evolving under infinite-temperature dynamics thee is a time interval (t_0, t_1)
such that \nu^t fails to be Gibbsian in d=2.


title: Recent results for Yang-Mills theory restricted to the Gribov region

abstract:
  We summarize recent results for the Gribov-Zwanziger Lagrangian which
includes the effect of restricting the path integral to the first Gribov
region. These include the two loop MSbar and one loop MOM gap equations for the
Gribov mass.


title: Dislocation Glasses: Aging during Relaxation and Coarsening

abstract:
  The dynamics of dislocations is reported to exhibit glassy properties. We
study numerically various versions of 2d edge dislocation systems in the
absence of externally applied stress. Two types of glassy behavior are
identified: (i) dislocations gliding along randomly placed, but fixed, axes
exhibit relaxation to their spatially disordered stable state; (ii) if both
climb and annihilation is allowed, irregular cellular structures can form on a
growing length scale before all dislocations annihilate. In all cases both the
correlation function and the diffusion coefficient are found to exhibit aging.
Relaxation in case (i) is a slow power law. In the transient process of (ii)
the dynamical exponent z is about 6, which compares favorably to experiments on
diblock co-polymers.


title: A C-13(alpha,n)O-16 calibration source for KamLAND

abstract:
  We report on the construction and performance of a calibration source for
KamLAND using the reaction C-13(alpha,n)O-16 with Po-210 as the alpha
progenitor. The source provides a direct measurement of this background
reaction in our detector, high energy calibration points for the detector
energy scale, and data on quenching of the neutron visible energy in KamLAND
scintillator. We also discuss the possibility of using the reaction
C-13(alpha,n)O-16 as a source of tagged slow neutrons.


title: First Colonization of a Spectral Outpost in Random Matrix Theory

abstract:
  We describe the distribution of the first finite number of eigenvalues in a
newly-forming band of the spectrum of the random Hermitean matrix model. The
method is rigorously based on the Riemann-Hilbert analysis of the corresponding
orthogonal polynomials. We provide an analysis with an error term of order
N^(-2 h) where 1/h = 2 nu+2 is the exponent of non-regularity of the effective
potential, thus improving even in the usual case the analysis of the pertinent
literature. The behavior of the first finite number of zeroes (eigenvalues)
appearing in the new band is analyzed and connected with the location of the
zeroes of certain Freud polynomials. In general all these newborn zeroes
approach the point of nonregularity at the rate N^(-h) whereas one (a stray
zero) lags behind at a slower rate of approach. The kernels for the correlator
functions in the scaling coordinate near the emerging band are provided
together with the subleading term: in particular the transition between K and
K+1 eigenvalues is analyzed in detail.


title: Di-Pion Decays of Heavy Quarkonium in the Field Correlator Method

abstract:
  Mechanism of di-pion transitions $nS\to n'S\pi\pi(n=3,2; n'=2,1)$ in
bottomonium and charmonium is studied with the use of the chiral
string-breaking Lagrangian allowing for the emission of any number of
$\pi(K,\eta),$ and not containing fitting parameters. The transition amplitude
contains two terms, $M=a-b$, where first term (a) refers to subsequent one-pion
emission: $\Upsilon(nS)\to\pi B\bar B^*\to\pi\Upsilon(n'S)\pi$ and second term
(b) refers to two-pion emission: $\Upsilon(nS)\to\pi\pi B\bar
B\to\pi\pi\Upsilon(n'S)$. The one-parameter formula for the di-pion mass
distribution is derived, $\frac{dw}{dq}\sim$(phase space) $|\eta-x|^2$, where
$x=\frac{q^2-4m^2_\pi}{q^2_{max}-4m^2_\pi},$ $q^2\equiv M^2_{\pi\pi}$. The
parameter $\eta$ dependent on the process is calculated, using SHO wave
functions and imposing PCAC restrictions (Adler zero) on amplitudes a,b. The
resulting di-pion mass distributions are in agreement with experimental data.


title: Collective Excitations of Trapped Imbalanced Fermion Gases

abstract:
  We present a theoretical study of the collective excitations of a trapped
imbalanced fermion gas at unitarity, when the system consists of a superfluid
core and a normal outer shell. We formulate the relevant boundary conditions
and treat the normal shell both hydrodynamically and collisionlessly. For an
isotropic trap, we calculate the mode frequencies as a function of trap
polarization. Out-of-phase modes with frequencies below the trapping frequency
are obtained for the case of a hydrodynamic normal shell. For the collisionless
case, we calculate the monopole mode frequencies, and find that all but the
lowest mode may be damped.


title: A Perl Package and an Alignment Tool for Phylogenetic Networks

abstract:
  Phylogenetic networks are a generalization of phylogenetic trees that allow
for the representation of evolutionary events acting at the population level,
like recombination between genes, hybridization between lineages, and lateral
gene transfer. While most phylogenetics tools implement a wide range of
algorithms on phylogenetic trees, there exist only a few applications to work
with phylogenetic networks, and there are no open-source libraries either.
  In order to improve this situation, we have developed a Perl package that
relies on the BioPerl bundle and implements many algorithms on phylogenetic
networks. We have also developed a Java applet that makes use of the
aforementioned Perl package and allows the user to make simple experiments with
phylogenetic networks without having to develop a program or Perl script by
herself.
  The Perl package has been accepted as part of the BioPerl bundle. It can be
downloaded from http://dmi.uib.es/~gcardona/BioInfo/Bio-PhyloNetwork.tgz. The
web-based application is available at http://dmi.uib.es/~gcardona/BioInfo/. The
Perl package includes full documentation of all its features.


title: Convolutional codes from units in matrix and group rings

abstract:
  A general method for constructing convolutional codes from units in Laurent
series over matrix rings is presented. Using group ring as matrix rings, this
forms a basis for in-depth exploration of convolutional codes from group ring
encoding, wherein the ring in the group ring is itself a group ring. The method
is used to algebraically construct series of convolutional codes. Algebraic
methods are used to compute free distances and to construct convolutional codes
to prescribed distances.


title: Prior-predictive value from fast growth simulations

abstract:
  Building on a variant of the Jarzynski equation we propose a new method to
numerically determine the prior-predictive value in a Bayesian inference
problem. The method generalizes thermodynamic integration and is not hampered
by equilibration problems. We demonstrate its operation by applying it to two
simple examples and elucidate its performance. In the case of multi-modal
posterior distributions the performance is superior to thermodynamic
integration.


title: Hadron production in non linear relativistic mean field models

abstract:
  By using a parametrization of the non-linear Walecka model which takes into
account the binding energy of different hyperons, we present a study of
particle production yields measured in central Au-Au collision at RHIC. Two
sets of different hyperon-meson coupling constants are employed in obtaining
the hadron production and chemical freeze-out parameters. These quantities show
a weak dependence on the used hyperon-meson couplings. Results are in good
overall accordance with experimental data. We have found that the repulsion
among the baryons is quite small and, through a preliminary analysis of the
effective mesonic masses, we suggest a way to improve the fittings.


title: On stability of randomly switched nonlinear systems

abstract:
  This article is concerned with stability analysis and stabilization of
randomly switched nonlinear systems. These systems may be regarded as piecewise
deterministic stochastic systems: the discrete switches are triggered by a
stochastic process which is independent of the state of the system, and between
two consecutive switching instants the dynamics are deterministic. Our results
provide sufficient conditions for almost sure global asymptotic stability using
Lyapunov-based methods when individual subsystems are stable and a certain
``slow switching'' condition holds. This slow switching condition takes the
form of an asymptotic upper bound on the probability mass function of the
number of switches that occur between the initial and current time instants.
This condition is shown to hold for switching signals coming from the states of
finite-dimensional continuous-time Markov chains; our results therefore hold
for Markov jump systems in particular. For systems with control inputs we
provide explicit control schemes for feedback stabilization using the universal
formula for stabilization of nonlinear systems.


title: Depletion potential in the infinite dilution limit

abstract:
  The depletion force and depletion potential between two in principle unequal
"big" hard spheres embedded in a multicomponent mixture of "small" hard spheres
are computed using the Rational Function Approximation method for the
structural properties of hard-sphere mixtures [S. B. Yuste, A. Santos, and M.
L\'opez de Haro, J. Chem. Phys. {\bf 108}, 3683 (1998)]. The cases of equal
solute particles and of one big particle and a hard planar wall in a background
monodisperse hard-sphere fluid are explicitly analyzed. An improvement over the
performance of the Percus-Yevick theory and good agreement with available
simulation results are found


title:
Self-energy and lifetime of Shockley and image states on Cu(100) and
  Cu(111): Beyond the GW approximation of many-body theory

abstract:
  We report many-body calculations of the self-energy and lifetime of Shockley
and image states on the (100) and (111) surfaces of Cu that go beyond the $GW$
approximation of many-body theory. The self-energy is computed in the framework
of the GW\Gamma approximation by including short-range exchange-correlation
(XC) effects both in the screened interaction W (beyond the random-phase
approximation) and in the expansion of the self-energy in terms of W (beyond
the GW approximation). Exchange-correlation effects are described within
time-dependent density-functional theory from the knowledge of an adiabatic
nonlocal XC kernel that goes beyond the local-density approximation.


title:
The GZK horizon and constraints on the cosmic ray source spectrum from
  observations in the GZK regime

abstract:
  We discuss the GZK horizon of protons and present a method to constrain the
injection spectrum of ultrahigh energy cosmic rays (UHECRs) from supposedly
identified extragalactic sources. This method can be applied even when only one
or two events per source are observed and is based on the analysis of the
probability for a given source to populate different energy bins, depending on
the actual CR injection spectral index. In particular, we show that for a
typical source density of $4\times 10^{-5} Mpc^{-3}$, a data set of 100 events
above $6\times 10^{19}$ eV allows one in 97% of all cases to distinguish a
source spectrum $dN/dE\propto E^{-1.1}$ from one with $E^{-2.7}$ at 95%
confidence level.


title:
Computing Stabilized Norms for Quantum Operations via the Theory of
  Completely Bounded Maps

abstract:
  The diamond and completely bounded norms for linear maps play an increasingly
important role in quantum information science, providing fundamental stabilized
distance measures for differences of quantum operations. Based on the theory of
completely bounded maps, we formulate an algorithm to compute the norm of an
arbitrary linear map. We present an implementation of the algorithm via Maple,
discuss its efficiency, and consider the case of differences of unitary maps.


title: Uniformity seminorms on $\ell^\infty$ and applications

abstract:
  A key tool in recent advances in understanding arithmetic progressions and
other patterns in subsets of the integers is certain norms or seminorms. One
example is the norms on $\Z/N\Z$ introduced by Gowers in his proof of
Szemer\'edi's Theorem, used to detect uniformity of subsets of the integers.
Another example is the seminorms on bounded functions in a measure preserving
system (associated to the averages in Furstenberg's proof of Szemer\'edi's
Theorem) defined by the authors. For each integer $k\geq 1$, we define
seminorms on $\ell^\infty(\Z)$ analogous to these norms and seminorms. We study
the correlation of these norms with certain algebraically defined sequences,
which arise from evaluating a continuous function on the homogeneous space of a
nilpotent Lie group on a orbit (the nilsequences). Using these seminorms, we
define a dual norm that acts as an upper bound for the correlation of a bounded
sequence with a nilsequence. We also prove an inverse theorem for the
seminorms, showing how a bounded sequence correlates with a nilsequence. As
applications, we derive several ergodic theoretic results, including a
nilsequence version of the Wiener-Wintner ergodic theorem, a nil version of a
corollary to the spectral theorem, and a weighted multiple ergodic convergence
theorem.


title:
Voltage profile and four terminal resistance of an interacting quantum
  wire

abstract:
  We investigate the behavior of the four-terminal resistance $R_{4pt}$ in a
quantum wire described by a Luttinger liquid in two relevant situations: (i) in
the presence of a single impurity within the wire and (ii) under the effect of
asymmetries introduced by dirty voltage probes. In the first case, interactions
leave a signature in a power law behavior of $R_{4pt}$ as a function of the
voltage $V$ and the temperature $T$. In the second case interactions tend to
mask the effect of the asymmetries. In both scenarios the occurrence of
negative values of $R_{4pt}$ is explained in simple terms.


title:
On manifestly sp(2) invariant formulation of quadratic higher spin
  Lagrangians

abstract:
  The Lagrangian frame-like formulation of free higher spin symmetric bosonic
AdS(d) fields is given within a manifestly sp(2) invariant framework. It is
designed to deal with infinite multiplets of fields appearing as gauge
connections of the higher spin algebras.


title:
Large-Scale Anisotropic Correlation Function of SDSS Luminous Red
  Galaxies

abstract:
  We study the large-scale anisotropic two-point correlation function using
46,760 luminous red galaxies at redshifts 0.16 -- 0.47 from the Sloan Digital
Sky Survey. We measure the correlation function as a function of separations
parallel and perpendicular to the line-of-sight in order to take account of
anisotropy of the large-scale structure in redshift space. We find a slight
signal of baryonic features in the anisotropic correlation function, i.e., a
``baryon ridge'' which corresponds to a baryon acoustic peak in the spherically
averaged correlation function which has already been reported using the same
sample. The baryon ridge has primarily a spherical structure with a known
radius in comoving coordinates. It enables us to divide the redshift distortion
effects into dynamical and geometrical components and provides further
constraints on cosmological parameters, including the dark energy
equation-of-state. With an assumption of a flat $\Lambda$ cosmology, we find
the best-fit values of $\Omega_{\rm m} = 0.218^{+0.047}_{-0.037}$ and
$\Omega_{\rm b} = 0.047^{+0.016}_{-0.016}$ (68% C.L.) when we use the overall
shape of the anisotropic correlation function of $40<s<200\himpc$ including a
scale of baryon acoustic oscillations. When an additional assumption
$\Omega_{\rm b}h^2=0.024$ is adopted, we obtain $\Omega_{\rm
DE}=0.770^{+0.051}_{-0.040}$ and $w=-0.93^{+0.45}_{-0.35}$. These constraints
are estimated only from our data of the anisotropic correlation function, and
they agree quite well with values both from the cosmic microwave background
(CMB) anisotropies and from other complementary statistics using the LRG
sample. With the CMB prior from the 3 year WMAP results, we give stronger
constraints on those parameters.


title:
Evolution of Primordial Black Holes in a radiation and phantom energy
  environment

abstract:
  In this work we extend previous work on the evolution of a Primordial Black
Hole (PBH) to address the presence of a dark energy component with a
super-negative equation of state as a background, investigating the competition
between the radiation accretion, the Hawking evaporation and the phantom
accretion, the latter two causing a decrease on black hole mass. It is found
that there is an instant during the matter-dominated era after which the
radiation accretion becomes negligible compared to the phantom accretion. The
Hawking evaporation may become important again depending on a mass threshold.
The evaporation of PBHs is quite modified at late times by these effects, but
only if the Generalized Second Law of thermodynamics is violated.


title: Galois theory in bicategories

abstract:
  We develop a Galois (descent) theory for comonads within the framework of
bicategories. We give generalizations of Beck's theorem and the Joyal-Tierney
theorem. Many examples are provided, including classical descent theory,
Hopf-Galois theory over Hopf algebras and Hopf algebroids, Galois theory for
corings and group-corings, and Morita-Takeuchi theory for corings. As an
application we construct a new type of comatrix corings based on (dual) quasi
bialgebras.


title:
Stability of Bounded Solutions for Degenerate Complex Monge-Amp\`ere
  equations

abstract:
  We generalize and strenghten Ko{\l}odziej's stability theorem. In particular
we give sharp stability exponent and treat the case with more singular right
hand side of the Monge-Amp\`ere equation.


title: Fluctuations as stochastic deformation

abstract:
  A notion of stochastic deformation is introduced and the corresponding
algebraic deformation procedure is developed. This procedure is analogous to
the deformation of an algebra of observables like deformation quantization, but
for an imaginary deformation parameter (the Planck constant). This method is
demonstrated on diverse relativistic and nonrelativistic models with finite and
infinite degrees of freedom. It is shown that under stochastic deformation the
model of a nonrelativistic particle interacting with the electromagnetic field
on a curved background passes into the stochastic model described by the
Fokker-Planck equation with the diffusion tensor being the inverse metric
tensor. The first stochastic correction to the Newton equations for this system
is found. The Klein-Kramers equation is also derived as the stochastic
deformation of a certain classical model. Relativistic generalizations of the
Fokker-Planck and Klein-Kramers equations are obtained by applying the
procedure of stochastic deformation to appropriate relativistic classical
models. The analog of the Fokker-Planck equation associated with the stochastic
Lorentz-Dirac equation is derived too. The stochastic deformation of the models
of a free scalar field and an electromagnetic field is investigated. It turns
out that in the latter case the obtained stochastic model describes a
fluctuating electromagnetic field in a transparent medium.


title:
Diophantine Approximation on varieties III: Approximation of
  non-algebraic points by algebraic points

abstract:
  For $\theta$ a non-algebraic point on a quasi projective variety over a
number field, I prove that $\theta$ has an approximation by a series of
algebraic points of bounded height and degree which is essentially best
possible.
  Applications of this result will include a proof of a slightly strengthened
version of the Philippon criterion, some new algebraic independence criteria,
statements concerning metric transcendence theory on varieties of arbitrary
dimension, and a rather accurate estimate for the number of algebraic points of
bounded height and degree on quasi projective varieties over number fields.


title: Intrinsic and Extrinsic Performance Limits of Graphene Devices on SiO2

abstract:
  The linear dispersion relation in graphene[1,2] gives rise to a surprising
prediction: the resistivity due to isotropic scatterers (e.g. white-noise
disorder[3] or phonons[4-8]) is independent of carrier density n. Here we show
that acoustic phonon scattering[4-6] is indeed independent of n, and places an
intrinsic limit on the resistivity in graphene of only 30 Ohm at room
temperature (RT). At a technologically-relevant carrier density of 10^12 cm^-2,
the mean free path for electron-acoustic phonon scattering is >2 microns, and
the intrinsic mobility limit is 2x10^5 cm^2/Vs, exceeding the highest known
inorganic semiconductor (InSb, ~7.7x10^4 cm^2/Vs[9]) and semiconducting carbon
nanotubes (~1x10^5 cm^2/Vs[10]). We also show that extrinsic scattering by
surface phonons of the SiO2 substrate[11,12] adds a strong temperature
dependent resistivity above ~200 K[8], limiting the RT mobility to ~4x10^4
cm^2/Vs, pointing out the importance of substrate choice for graphene
devices[13].


title: Dual Fermion Approach to Susceptibility of Correlated Lattice Fermions

abstract:
  In this paper, we show how the two-particle Green function (2PGF) can be
obtained within the framework of the Dual Fermion approach. This facilitates
the calculation of the susceptibility in strongly correlated systems where
long-ranged non-local correlations cannot be neglected. We formulate the
Bethe-Salpeter equations for the full vertex in the particle-particle and
particle-hole channels and introduce an approximation for practical
calculations. The scheme is applied to the two-dimensional Hubbard model at
half filling. The spin-spin susceptibility is found to strongly increase for
the wavevector $\vc{q}=(\pi,\pi)$, indicating the antiferromagnetic
instability. We find a suppression of the critical temperature compared to the
mean-field result due to the incorporation of the non-local spin-fluctuations.


title: Parastatistics Algebra and Super Semistandard Young Tableaux

abstract:
  We consider the parastatistics algebra with both parabosonic and
parafermionic operators and show that the states in the universal
parastatistics Fock space are in bijection with the Super Semistandard Young
Tableaux (SSYT). Using deformation of the parastatistics algebra we get a
monoid structure on SSYT which is a super version of the plactic monoid.


title: Plasmon spectra of nanospheres under a tightly focused beam

abstract:
  We study the modification of the far-field cross sections and the near-field
enhancement for gold and silver nanospheres illuminated by a tightly focused
beam. Using a multipole-expansion approach we obtain an analytical solution to
the scattering problem and provide insight on the effects of focusing on the
optical response. Large differences with respect to Mie theory are found
especially when the nanoparticle supports quadrupole or higher-order
resonances.


title: Origin of neutron star magnetic fields

abstract:
  Possible origins of the magnetic fields of neutron stars include inheritance
from the main sequence progenitor and dynamo action at some stage of evolution
of progenitor. Inheritance is not sufficient to explain the fields of
magnetars. Energetic considerations point to differential rotation in the final
stages of core collapse process as the most likely source of field generation,
at least for magnetars. A runaway phase of exponential growth is needed to
achieve sufficient field amplification during relevant phase of core collapse;
it can probably be provided by a some form of magnetorotational instability.
Once formed in core collapse, the field is in danger of decaying again by
magnetic instabilities. The evolution of a magnetic field in a newly formed
neutron star is discussed, with emphasis on the existence of stable equilibrium
configurations as end products of this evolution, and the role of magnetic
helicity in their existence.


title: Lectures on zeta functions over finite fields

abstract:
  These are the notes from the summer school in G\"ottingen sponsored by NATO
Advanced Study Institute on Higher-Dimensional Geometry over Finite Fields that
took place in 2007. The aim was to give a short introduction on zeta functions
over finite fields, focusing on moment zeta functions and zeta functions of
affine toric hypersurfaces.


title: Sequential Implementation of Global Quantum Operations

abstract:
  We study the possibility for a global unitary applied on an arbitrary number
of qubits to be decomposed in a sequential unitary procedure, where an
ancillary system is allowed to interact only once with each qubit. We prove
that sequential unitary decompositions are in general impossible for genuine
entangling operations, even with an infinite-dimensional ancilla, being the
controlled-NOT gate a paradigmatic example. Nevertheless, we find particular
nontrivial operations in quantum information that can be performed in a
sequential unitary manner, as is the case of quantum error correction and
quantum cloning.


title: Self-accelerating solutions of scalar-tensor gravity

abstract:
  Scalar-tensor gravity is the simplest and best understood modification of
general relativity, consisting of a real scalar field coupled directly to the
Ricci scalar curvature. Models of this type have self-accelerating solutions.
In an example inspired by string dilaton couplings, scalar-tensor gravity
coupled to ordinary matter exhibits a de Sitter type expansion, even in the
presence of a {\it negative} cosmological constant whose magnitude exceeds that
of the matter density. This unusual behavior does not require phantoms, ghosts
or other exotic sources. More generally, we show that any expansion history can
be interpreted as arising partly or entirely from scalar-tensor gravity. To
distinguish any quintessence or inflation model from its scalar-tensor
variants, we use the fact that scalar-tensor models imply deviations of the
post-Newtonian parameters of general relativity, and time variation of the
Newton's gravitational coupling $G$. We emphasize that next-generation probes
of modified GR and the time variation of $G$ are an essential complement to
dark energy probes based on luminosity-distance measurements.


title:
Asymptotic Expansion of the Homoclinic Splitting Matrix for the Rapidly,
  Quasiperiodically, Forced Pendulum

abstract:
  We study a Hamiltonian describing a pendulum coupled with several
anisochronous oscillators, devising an asymptotic expansion for the splitting
(matrix) associated with a homoclinic point. This expansion consists of
contributions that are manifestly exponentially small in the limit of vanishing
hyperbolicity, by a shift-of-contour argument. Hence, we infer a similar upper
bound on the splitting itself.


title:
Coupling of plasmonic nanoparticles to their environments in the context
  of van der Waals-Casimir interactions

abstract:
  We present experiments in which the interaction of a single gold nanoparticle
with glass substrates or with another gold particle can be tuned by in-situ
control of their separations using scanning probe technology. We record the
plasmon resonances of the coupled systems as a function of the polarization of
the incident field and the particle position. The distinct spectral changes of
the scattered light from the particle pair are in good agreement with the
outcome of finite difference time-domain (FDTD) calculations. We believe our
experimental technique holds promise for the investigation of the van der
Waals-Casimir type interactions between nanoscopic neutral bodies.